JPH04342264A - Capsule toner for heat pressure fixing - Google Patents

Abstract

PURPOSE:To provide the capsule toner for heat pressure fixing which has excellent offset resistance and blocking resistance, allows fixing at a low fixing temp. and can stably form bright images free from scumming many times. CONSTITUTION:This capsule toner is constituted of a hot meltable core material contg. coloring agents and a positively charged charge control agent and a shell. The essential component of the shell consists of a resin formed by bringing a univalent or bivalent or higher valency isocyanate compd. and/or isothiocyanate compd. and a compd. having 1 piece and >=2 pieces of active hydrogen reacting with an isocyanate group and/or isothiocyanate group into reaction respectively within a range of 1:1 to 1:20 ratio of molar number. At least >=30% of the number of the bonds contributed by all the isocyanate groups and/or isothiocyanate groups in this resin are the bonds exhibiting a thermal dissociation property.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a capsule toner used for developing electrostatic latent images formed in electrophotography, electrostatic printing, electrostatic recording, etc. This invention relates to fixing capsule toner. Furthermore, the patent application Hei 3-14
The present invention relates to an improvement of the capsule toner for heat and pressure fixing described in the specification of No. 231.

0002

[Prior Art and Problems to be Solved by the Invention] Conventional electrophotographic methods include, as described in US Pat. No. 2,297,691 and US Pat.
A photoconductive insulating layer is uniformly charged, the layer is then exposed to light, and the charge on the exposed portions is dissipated to form an electrical latent image, which is then coated with a color called toner. After the visible image is transferred to a transfer material such as transfer paper (transfer process), it is visualized by attaching a fine powder with an electric charge (development process). It consists of a process of permanently fixing by a fixing method (fixing step).

[0003] As described above, the toner must have the functions required not only in the development process but also in each process, such as the transfer process and the fixing process.

Generally, toner is subjected to mechanical frictional force due to shearing force and impact force during mechanical operation in a developing device.
It deteriorates while copying several thousand to tens of thousands of copies. To prevent such toner deterioration, it is best to use a strong resin with a large molecular weight that can withstand mechanical friction, but these resins generally have a high softening point and are suitable for non-contact fixing methods such as oven fixing and infrared fixing. In radiant fixing, fixing cannot be performed sufficiently due to poor thermal efficiency.Also, in the heat pressure fixing method using a heat roller, etc., which is widely used due to the contact fixing method having good thermal efficiency, it is necessary to use heat to achieve sufficient fixing. It is necessary to raise the temperature of the roller, which not only causes problems such as deterioration of the fixing device, curling of paper, and increased energy consumption, but also has poor pulverization properties when using such resins, so it is difficult to use when manufacturing toner. , manufacturing efficiency is significantly reduced. Therefore, it is not possible to use a binder resin whose polymerization degree and even softening point are too high.

On the other hand, the heat-pressure fixing method using a heat roller or the like has extremely good thermal efficiency because the surface of the heating roller and the toner image surface of the sheet to be fixed come into pressure contact, and is widely used from low speeds to high speeds. When the toner image surface comes into contact with the heating roller, a so-called offset phenomenon tends to occur, in which the toner adheres to the surface of the heating roller and is transferred to a subsequent transfer paper or the like. In order to prevent this phenomenon, the surface of the heating roller is treated with a material with excellent mold release properties such as a fluorine-based resin, and in addition, a mold release agent such as silicone oil is coated on the surface of the heating roller. However, the method of applying silicone oil or the like is not preferable because it not only increases the size of the fixing device and increases the cost, but also makes it complicated, which can easily cause trouble.

[0006] Also, Japanese Patent Publication No. 57-493, Japanese Patent Publication No. 5
As described in No. 0-44836 and JP-A No. 57-37353, there is a method of improving the offset phenomenon by making the resin asymmetrical and crosslinking, but the fixing point has not been improved.

Generally, the minimum fixing temperature is between the low temperature offset and the high temperature offset, so the usable temperature range is between the minimum fixing temperature and the high temperature offset. By increasing the temperature as much as possible, the fixing temperature used can be lowered and the usable temperature range can be expanded, resulting in energy savings, high-speed fixing, and prevention of paper curl.

[0008] Therefore, a toner with good fixing properties and anti-offset properties is always desired.

[0009] Hitherto, a technique has been proposed for achieving low-temperature fixability by using a capsule toner, which is composed of a core material and an outer shell provided to cover the surface of the core material, as a toner. .

[0010] Among these, when a low melting point wax or the like which is easily plastically deformed is used as the core material (US Pat. No. 3,269,62
No. 6, Special Publication No. 15876, Special Publication No. 1973, Special Publication No. 1973, Special Publication No. 1973
No. 880, JP-A-48-75032, JP-A-48-
No. 75033), it can be fixed using only pressure, but its fixing strength is poor and it can only be used for limited purposes.

[0011] Also, if a liquid material is used as the core material,
If the strength of the shell material is low, it will settle with pressure alone, but
It could crack inside the developing device, staining the inside of the machine, and if the shell material was strong, a lot of pressure was required to break the capsule, resulting in an image that was too glossy, making it difficult to adjust the strength of the shell material. .

Therefore, for heat-pressure fixing, blocking occurs at high temperatures when used alone as a core material, but a resin with a low glass transition point that improves fixing strength is used, and the outer shell has anti-blocking properties. For this purpose, a microcapsule type toner for thermal roller fixation has been devised in which a resin wall with a high melting point is formed using an interfacial polymerization method (Japanese Patent Application Laid-open No. 56352/1983), but the wall material has a high melting point. Therefore, the performance of the core material could not be brought out completely. In addition, based on the same concept, a capsule toner for heat roller fixing has been proposed in which the fixing strength of the core material is improved (Japanese Patent Application Laid-Open No. 1983-1999).
No. 128357, No. 63-128358, No. 63-1
No. 28359, No. 63-128360, No. 63-12
No. 8361 and No. 63-128362), the spray drying method was used, which placed a load on the manufacturing equipment, and the shell material was not designed properly, so the performance of the core material could not be brought out.

There have also been attempts to control the chargeability of the capsule toner by adding a charge control agent in the outer shell of the capsule toner or on the surface of the capsule toner. The charge control agent is detached and adheres to the carrier, reducing the amount of charge on the toner.
This has caused problems such as background smearing and toner scattering inside the machine. Furthermore, when no charge control agent is present on the surface of the toner, the charging speed may be slow depending on the type of carrier, and background smudges, toner scattering, etc. may occur during high-speed printing.

The present invention has been made based on the above-mentioned circumstances, and its objects are to provide a heat roller or other heat-pressure fixing method with excellent offset resistance, to enable fixing at a low fixing temperature, and to provide a An object of the present invention is to provide a capsule toner for heat and pressure fixing that has excellent blocking resistance. Another object of the present invention is to provide a capsule toner for heat-pressure fixing that is capable of stably forming clear images without background smudge over many times by controlling the chargeability of the toner from inside the capsule toner. .

[0015]

[Means for Solving the Problems] As a result of intensive research aimed at solving the above-mentioned problems, the present inventors have completed the present invention.

That is, the present invention provides at least a coloring agent and a
This is a capsule toner for heat and pressure fixing that is composed of a heat-melting core material containing a seed or two or more negatively chargeable charge control agents, and an outer shell provided to cover the surface of the core material. The main components of the shell are (1) monovalent isocyanate compounds and/or isothiocyanate compounds in an amount of 0 to 30 mol% of the total isocyanate compounds and/or isothiocyanate compounds, (2
) Divalent or higher isocyanate compounds and/or isothiocyanate compounds in an amount of 100 to 70 mol% of the total isocyanate compounds and/or isothiocyanate compounds.
and (3) 0 to 30 mol% of the total compound that reacts with isocyanate groups and/or isothiocyanate groups, (4) isocyanate groups and 100 of all compounds that react with isocyanate groups and/or isothiocyanate groups, including compounds having two or more active hydrogens that react with isothiocyanate groups
~70 mol% and the number of moles of (1) + (2) and (
3)+(4) in a molar ratio of 1:1 to 1:20, and among all the bonds involving isocyanate groups and/or isothiocyanate groups in the resin, This invention relates to a capsule toner for heat-pressure fixing, characterized in that at least 30% or more of the bonds are thermally dissociable bonds.

In the present invention, it is preferable that the thermally dissociable bond is a bond derived from a reaction between a phenolic hydroxyl group and/or thiol group and an isocyanate group and/or isothiocyanate group; The main component of the heat-fusible core material in the capsule toner is a thermoplastic resin, and the glass transition point derived from the resin is 10 to 50°C, and the softening point of the capsule toner is 8.
If the temperature is 0 to 150°C, even better characteristics can be brought out.

In the present invention, examples of the negatively chargeable charge control agent added to the core material include metal-containing azo dyes such as "Varifast Black 3804" and "Bontron S".
-31", "Bontron S-32", "Bontron S-
Copper phthalocyanine dyes, metal complexes of alkyl derivatives of salicylic acid, such as "Bontron E-81" and "Bontron E-
82", "Bontron E-85" (manufactured by Orient Chemical Co., Ltd.), quaternary ammonium salts, such as "COPY C
HARGE NX VP434'' (manufactured by Hoechst), nitroimidazole derivatives, and others.

It is also possible to use a negatively chargeable charge control agent and a positively chargeable charge control agent in combination, and the amount of the positively chargeable charge control agent used is 1/2 or less of the amount of the negatively chargeable charge control agent used. Then, depending on the carrier or the like to be charged, the charging stability of the toner becomes even better, and even if printing is performed continuously on 100,000 sheets or more, good visible images can be obtained without a decrease in density.

Examples of positively chargeable charge control agents include nigrosine dyes such as "Nigrosine Base EX", "Oil Black BS", "Oil Black SO", "Bontron N-01", "Bontron N-07", and " Triphenylmethane dyes containing tertiary amines as side chains, such as “Bontron N-11” (manufactured by Orient Chemical Co., Ltd.);
Quaternary ammonium salt compounds, such as "Bontron P-5"
1” (manufactured by Orient Chemical Co., Ltd.), cetyltrimethylammonium bromide, “COPYCHARGE PX VP
435'' (manufactured by Hoechst), polyamine resins such as ``AFP-B'' (manufactured by Orient Chemical Co., Ltd.), imidazole derivatives, and others.

[0021] As described above, the charge control agent is contained in the core material in an amount of 0.1 to 8
．． 0% by weight, preferably 0.2-5.0% by weight
Contains.

In the present invention, the bond exhibiting thermal dissociation is preferably a bond derived from a reaction between a phenolic hydroxyl group and/or a thiol group and an isocyanate group and/or an isothiocyanate group. The urethane bond is a bond that dissociates into an isocyanate group and a hydroxyl group at a certain temperature, and is also called a blocked isocyanate and is well known in the field of paints.

Blocking of polyisocyanates is as follows:
It is a well-known method for temporarily preventing the reaction between isocyanate groups and active hydrogen-containing compounds, and is described by Z. W. W
icks jr. , Prog. in Org. Co
Various blocking agents, such as tertiary alcohols,
Phenols, acetoacetate, ethyl malonate, etc. are listed.

[0024] It is important that the heat-dissociable polyurethane preferably used in the present invention has a low heat-dissociation temperature;
．． R. Grittin and L. J. Will we
rth, Ind. Eng. Chem. Prod
．． Res. Develop. , 1, 265 (19
62), among urethane bonds, resins with urethane bonds produced by the reaction between isocyanate compounds and phenolic hydroxyl groups have a low thermal dissociation temperature and are preferably used. .

Thermal dissociation is an equilibrium reaction, for example as shown in the following equation, and it is known that the reaction progresses from the right equation to the left equation as the temperature increases.

[0026]

[C4]

(Ar represents an aromatic group.) Examples of the monovalent isocyanate compound (1) used in the present invention include ethyl isocyanate, octyl isocyanate, 2-chloroethyl isocyanate, chlorosulfonyl isocyanate, and isocyanate. cyclohexyl acid, n-dodecyl isocyanate, butyl isocyanate, n-hexyl isocyanate, lauryl isocyanate, phenyl isocyanate, m-chlorophenyl isocyanate, 4-chlorophenyl isocyanate, p-cyanophenyl isocyanate, isocyanate 3, 4-dichlorophenyl, isocyanate o-
Tolyl, m-tolyl isocyanate, p-tolyl isocyanate, p-toluenesulfonyl isocyanate, 1-naphthyl isocyanate, o-nitrophenyl isocyanate,
m-nitrophenyl isocyanate, p-nitrophenyl isocyanate, phenyl isocyanate, p-isocyanate
-bromophenyl, o-methoxyphenyl isocyanate, m-methoxyphenyl isocyanate, p isocyanate
- Monovalent isocyanate compounds such as methoxyphenyl, ethyl isocyanatoacetate, butyl isocyanatoacetate, and trichloroacetyl isocyanate.

Examples of the isocyanate compound (2) having a valence of 2 or more used in the present invention include 2,4-tolylene diisocyanate, a dimer of 2,4-tolylene diisocyanate, and 2,6-tolylene diisocyanate. , p-xylylene diisocyanate, m-xylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, 3
, 3'-dimethyl-diphenyl-4,4'-diisocyanate, 3,3'-dimethyl-diphenylmethane-4,
Aromatic isocyanate compounds such as 4'-diisocyanate, metaphenylene diisocyanate, triphenylmethane-triisocyanate, diphenylmethane triisocyanate, polymethylene phenyl isocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate,
Dimer acid diisocyanate, butane-1,2,2-
Aliphatic isocyanate compounds such as triisocyanate, isophorone diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), methylcyclohexane-2,4 (or 2,6) diisocyanate,
Examples include alicyclic isocyanate compounds such as 1,3-(isocyanatomethyl)cyclohexane, and isocyanate compounds such as an adduct of 3 moles of tolylene diisocyanate and 1 mole of trimethylolpropane.

Further, as compounds having an isothiocyanate group, phenyl isothiocyanate, xylylene-1
, 4-diisothiocyanate, ethyridine diisothiocyanate, and the like.

Among them, compounds in which an isocyanate group is directly bonded to an aromatic ring are effective in lowering the thermal dissociation temperature after urethane bond formation, and are preferably used.

In the present invention, the monovalent isocyanate compound and/or isothiocyanate compound (1) can be used in an amount up to 30 mol% of the total isocyanate compound and/or isothiocyanate compound to also adjust the molecular weight of the outer shell resin. However, if it exceeds 30 mol%, the storage stability of the capsule toner deteriorates, which is not preferable.

In the present invention, (3) compounds having one active hydrogen that reacts with isocyanate groups and/or isothiocyanate groups include methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol,
Aliphatic alcohols such as t-butyl alcohol, pentyl alcohol, hexyl alcohol, cyclohexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, lauryl alcohol, stearyl alcohol, phenol, o-cresol, m-cresol, p-cresol , 4-butylphenol, 2-sec -butylphenol, 2-ter
t-Butylphenol, 3-tert-butylphenol, 4-tert-butylphenol, nonylphenol, isononylphenol, 2-propenylphenol, 3-propenylphenol, 4-propenylphenol, 2-methoxyphenol, 3-methoxyphenol, 4-methoxyphenol , 3-acetylphenol,
3-carbomethoxyphenol, 2-chlorophenol, 3-chlorophenol, 4-chlorophenol, 2-
Bromophenol, 3-bromophenol, 4-bromophenol, benzyl alcohol, 1-naphthol, 2
Examples include aromatic alcohols such as -naphthol and 2-acetyl-1-naphthol, and amides such as ε-caprolactam.

Among these, phenol derivatives represented by the following formula (I) are preferably used.

[0034]

[C5]

(In the formula, R1, R2, R3, R4,
R5 independently represents H, or an alkyl group, alkenyl group, alkoxy group, alkanoyl group, carbalkoxy group, or aryl group having 1 to 9 carbon atoms, or a halogen. ) Among the compounds having two or more active hydrogens that react with isocyanate groups and/or isothiocyanate groups (4) used in the present invention, examples of dihydric or higher alcohol compounds include catechol, resorcinol, hydroquinone, 4- Methylcatechol, 4-t-butylcatechol, 4-acetylcatechol, 3-methoxycatechol, 4-phenylcatechol, 4-methylresorcin, 4-ethylresorcin, 4-t-butylresorcin,
4-hexylresorcin, 4-chlororesorcin, 4-
Benzylresorcin, 4-acetylresorcin, 4-carbomethoxyresorcin, 2-methylresorcin, 5-
Methylresorcin, t-butylhydroquinone, 2,5
-di-t-butylhydroquinone, 2,5-di-t
-amylhydroquinone, tetramethylhydroquinone, tetrachlorohydroquinone, methylcarboaminohydroquinone, methylureidohydroquinone, benzonorbornene-3,6-diol, bisphenol A
, bisphenol S, 3,3'-dichlorobisphenol S, 2,2'-dihydroxybenzophenone, 2,4
-dihydroxybenzophenone, 4,4'-dihydroxybenzophenone, 2,2'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl, 2,2'-dihydroxydiphenylmethane, 3,4-bis(p-hydroxyphenyl)hexane, 1 ,4-bis(2-(
p-hydroxyphenyl)propyl)benzene, bis(
4-hydroxyphenyl)methylamine, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 2,6-
Dihydroxynaphthalene, 1,5-dihydroxyanthraquinone, 2-hydroxybenzyl alcohol, 4-
Hydroxybenzyl alcohol, 2-hydroxy-3,
5-di-t-butylbenzyl alcohol, 4-hydroxy-3,5-di-t-butylbenzyl alcohol,
4-Hydroxyphenethyl alcohol, 2-hydroxyethyl-4-hydroxybenzoate, 2-hydroxyethyl-4-hydroxyphenylacetate, resorcin mono-2-hydroxyethyl ether, hydroxyhydroquinone, gallic acid, 3,4,5-trihydroxy Examples include ethyl benzoate. Among them, the following formula (II)
A catechol derivative represented by the formula (III) or a resorcinol derivative represented by the following formula (III) is preferably used.

[0036]

[C6]

(In the formula, R6, R7, R8, R9 independently represent H, or an alkyl group having 1 to 6 carbon atoms, an alkenyl group, an alkoxy group, an alkanoyl group, a carboalkoxy group, an aryl group, or a halogen) .)

[0038]

[C7]

(In the formula, R10, R11, R12,
R13 independently represents H, or an alkyl group, alkenyl group, alkoxy group, alkanoyl group, carbalkoxy group, or aryl group having 1 to 6 carbon atoms, or a halogen. ) In addition, examples of compounds having at least one functional group other than a hydroxyl group that react with an isocyanate group and/or an isothiocyanate group and having at least one phenolic hydroxyl group include o-hydroxybenzoic acid, m -Hydroxybenzoic acid, p-hydroxybenzoic acid, 5-bromo-2-hydroxybenzoic acid, 3-chloro-4-hydroxybenzoic acid, 4-chloro-
2-hydroxybenzoic acid, 5-chloro-2-hydroxybenzoic acid, 3,5-dichloro-4-hydroxybenzoic acid, 3-methyl-2-hydroxybenzoic acid, 5-methoxy-2-hydroxybenzoic acid, 3, 5-di-t-butyl-4-hydroxybenzoic acid, 4-amino-2-hydroxybenzoic acid, 5-amino-2-hydroxybenzoic acid,
2,5-dinitrosalicylic acid, sulfosalicylic acid, 4
-hydroxy-3-methoxyphenylacetic acid, catechol-4-carboxylic acid, 2,4-dihydroxybenzoic acid,
2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 3,
5-dihydroxybenzoic acid, 3,4-dihydroxyphenylacetic acid, m-hydroxycinnamic acid, p-hydroxycinnamic acid, 2-amino-4-methylphenol, 2-amino-5-methylphenol, 5-amino-2- Methylphenol, 3-amino-2-naphthol, 8-amino-
2-naphthol, 1-amino-2-naphthol-4-sulfonic acid, 2-amino-5-naphthol-4-sulfonic acid, 2-amino-4-nitrophenol, 4-amino-
2-nitrophenol, 4-amino-2,6-dichlorophenol, o-aminophenol, m-aminophenol, p-aminophenol, 4-chloro-2-aminophenol, 1-amino-4-hydroxyanthraquinone, 5 -Chloro-2-hydroxyaniline, α-cyano-3-hydroxycinnamic acid, α-cyano-4-hydroxycinnamic acid, 1-hydroxynaphthoic acid, 2-hydroxynaphthoic acid, 3-hydroxynaphthoic acid, 4-hydroxyphthalic acid Examples include acids.

[0040] Examples of polythiol compounds having one or more thiol groups in one molecule include ethanethiol, 1
-propanethiol, 2-propanethiol, thiophenol, bis(2-mercaptoethyl)ether, 1,
2-ethanedithiol, 1,4-butanedithiol, bis(2-mercaptoethyl) sulfide, ethylene glycol bis(2-mercaptoacetate), ethylene glycol bis(3-mercaptopropionate),
2,2-dimethylpropanediol bis(2-mercaptoacetate), 2,2-dimethylpropanediol bis(3-mercaptopropionate), trimethylolpropane tris(2-mercaptoacetate), trimethylolpropane tris(3-mercaptoacetate) mercaptopropionate), trimethylolethane tris (2-mercaptoacetate), trimethylolethane tris (3-mercaptopropionate), pentaerythritol tetrakis (2-mercaptoacetate), pentaerythritol tetrakis (3-mercaptopropionate) ),
Dipentaerythritol hexakis (2-mercaptoacetate), dipentaerythritol hexakis (3-mercaptoacetate)
mercaptopropionate), 1,2-dimercaptobenzene, 4-methyl-1,2-dimercaptobenzene, 3,6-dichloro-1,2-dimercaptobenzene, 3,4,5,6-tetrachloro -1,2-dimercaptobenzene, xylylene dithiol, 1,3,
Examples include 5-tris(3-mercaptopropyl)isocyanurate.

In the thermally dissociable outer shell resin used in the present invention, the thermally dissociable bonds are all isocyanate groups and/or
Of the bonds involving isothiocyanate groups, at least 30% or more is required, preferably 50%. This thermally dissociable bond is 30 times the number of bonds involving all isocyanate groups and/or isothiocyanate groups.
If it is less than %, the capsule outer shell strength will not be sufficiently reduced during heat-pressure fixing, and the excellent fixing performance of the core material will not be brought out.

In the present invention, phenol is used to the extent that the number of bonds resulting from reactions with phenolic hydroxyl groups and/or thiol groups is not less than 30% of all bonds involving isocyanate groups and/or isothiocyanate groups. Compounds having a functional group other than a functional hydroxyl group and/or a thiol group that reacts with an isocyanate group, such as malonic acid esters as shown below, active methylene group-containing compounds such as acetoacetic esters, and oximes such as methyl ethyl ketone oxime. etc., carboxylic acids, polyols, polyamines, aminocarboxylic acids, aminoalcohols, etc. can be used as shell-forming substances.

The active methylene group-containing compound is as follows:
malonic acid, monomethyl malonate, monoethyl malonate,
Isopropyl malonate, dimethyl malonate, diethyl malonate, diisopropyl malonate, tert-malonate
Butylethyl, malonic acid diamide, acetylacetone,
Methyl acetoacetate, ethyl acetoacetate, te acetoacetate
Examples include active methylene group-containing compounds such as rt-butyl and allyl acetoacetate.

Examples of the carboxylic acids include monovalent carboxylic acids such as acetic acid, propionic acid, butyric acid, isobutyric acid, pentanoic acid, hexanoic acid, benzoic acid, maleic acid, fumaric acid,
citraconic acid, itaconic acid, glutaconic acid, phthalic acid,
Isophthalic acid, terephthalic acid, succinic acid, adipic acid,
Divalent carboxylic acids such as sebacic acid, azelaic acid, malonic acid, n-todecenylsuccinic acid, isododecenylsuccinic acid, n-todecylsuccinic acid, isododecylsuccinic acid, n-octenylsuccinic acid, n-octylsuccinic acid, etc., 1 ,2
, 4-benzenetricarboxylic acid, 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,
Trivalent or higher carboxylic acids such as 8-octane tetracarboxylic acid, pyromellitic acid, and empol trimer acid can be mentioned.

Examples of the polyols include diols such as ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, hexamethylene glycol, diethylene glycol, and dipropylene glycol, glycerin, trimethylolpropane,
Triols such as trimethylolethane, 1,2,6-hexanetriol, pentaerythritol, and water may be mentioned, and examples of the polyamines include ethylenediamine, hexamethylenediamine, diethylenetriamine, iminobispropylamine, phenylenediamine, Examples include xylylene diamine and triethylenetetramine.

In the present invention, the compound (3) having one active hydrogen that reacts with isocyanate groups and/or isothiocyanate groups is used in an amount up to 30 mol% of the total compounds that react with isocyanate groups and/or isothiocyanate groups. However, if it exceeds 30 mol%, the storage stability of the capsule toner deteriorates, which is not preferable.

[0047] Also, isocyanate compounds and/or isothiocyanate compounds [(1) + (2
) ] and the compound [(3) + (4) ] which reacts with isocyanate groups and/or isothiocyanate groups, the molar ratio is 1:1 to 1:20 in order to prevent unreacted isocyanate groups from remaining. is preferred.

In the production of capsule toner, the outer shell is preferably formed by interfacial polymerization or in-situ polymerization. For example, the number average particle diameter of the base particle as a core material is 1/1 of the number average particle diameter of the base particle. A dry method may be used in which the outer shell is formed by stirring the outer shell-forming material child particles having a particle diameter of 8 or less at high speed in an air current.

The resin for the outer shell can be produced without a catalyst, but when using a catalyst, tin-based catalysts such as dibutyltin dilaurate, 1,4-diazabicyclo[2.2.2]octane, N,N,N Known urethane catalysts such as amine catalysts such as -tris(dimethylaminopropyl)-hexahydro-S-triazine can be used.

The resin used for the core material of the capsule toner of the present invention has a glass transition point (Tg) of 10°C or higher and 5°C.
Thermoplastic resins such as polyester resins, polyester/polyamide resins, polyamide resins, and vinyl resins having a temperature of 0° C. or lower may be mentioned, and vinyl resins are particularly preferred.

Examples of monomers constituting the vinyl resin include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, and p-methylstyrene.
Styrene or styrene derivatives such as ethylstyrene, 2,4-dimethylstyrene, p-chlorostyrene, vinylnaphthalene, ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, isobutylene, etc., such as vinyl chloride, vinyl bromide, etc. , vinyl fluoride,
Vinyl esters such as vinyl acetate, vinyl propionate, vinyl formate, vinyl caproate, etc., such as acrylic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-acrylate
-Butyl, isobutyl acrylate, t-butyl acrylate, amyl acrylate, cyclohexyl acrylate, n-octyl acrylate, isooctyl acrylate, decyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, acrylic Methoxyethyl acrylate, 2-hydroxyethyl acrylate, glycidyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, methacrylate Isopropyl acid, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, amyl methacrylate, cyclohexyl methacrylate, n-octyl methacrylate, isooctyl methacrylate, decyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate , stearyl methacrylate, methoxyethyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, etc. and ethylenic monocarboxylic acids and their esters, such as acrylonitrile, Substituted ethylenic monocarboxylic acids such as methacrylonitrile, acrylamide, etc., ethylenic dicarboxylic acids such as dimethyl maleate and substituted products thereof, vinyl ketones such as vinyl methyl ketone, vinyl ethers such as vinyl methyl ether, etc. vinylidene halides such as vinylidene chloride, e.g. N-vinylpyrrole, N-
There are N-vinyl compounds such as vinylpyrrolidone and the like.

Preferably, among the components constituting the resin for the core material according to the present invention, 50 to 90 parts by weight of styrene or a styrene derivative is used to form the main skeleton of the resin, and it is preferable to use styrene or a styrene derivative in an amount of 50 to 90 parts by weight. Preferably 10 to 50 parts by weight of ethylenic monocarboxylic acids and their esters are used for conditioning.

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, etc. 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, 2,2'-bis(4-acrylic General crosslinking agents such as (oxydiethoxyphenyl)propane, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, dibromneopentyl glycol dimethacrylate, diallyl phthalate, etc.
If necessary, two or more types can be used in combination).

If these crosslinking agents are used in a large amount, the toner becomes difficult to melt by heat, resulting in poor heat fixing properties or heat pressure fixing properties. Furthermore, if the amount used is small, it becomes difficult to prevent an offset phenomenon in which a portion of the toner does not completely adhere to the paper and adheres to the roller surface and is transferred to the next paper during heat-pressure fixing. Furthermore, the amount of these crosslinking agents used is
It is preferably used in an amount of 0.001 to 15% by weight (more preferably 0.1 to 10% by weight) based on the polymerizable monomer.

[0055] Further, the above monomer is polymerized in the presence of an unsaturated polyester to form a graft or crosslinked polymer,
It may also be used as a resin for core material.

Further, as a polymerization initiator used in producing vinyl resin, 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 peroxy carbonate, cumene Examples include peroxide-based polymerization initiators such as hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, and dicumyl peroxide.

Two or more types of polymerization initiators may be used in combination for the purpose of adjusting the molecular weight and molecular weight distribution of the polymer, or for the purpose of adjusting the reaction time.

The amount of the polymerization initiator used is 100% of the polymerized monomer.
0.1 to 20 parts by weight, preferably 1 part by weight
~10 parts by weight.

If necessary, the core material may contain, for example, polyolefin, fatty acid metal salt, fatty acid ester, partially saponified fatty acid ester, higher fatty acid, higher alcohol, paraffin wax, for the purpose of improving offset resistance during heat-pressure fixing. , amide wax, polyhydric alcohol ester, silicone varnish, aliphatic fluorocarbon, silicone oil, or any other one or more offset inhibitors may be contained.

[0060] The polyolefin is, for example, a resin such as polypropylene, polyethylene, or polybutene, and has a softening point of 80 to 160°C. Examples of the fatty acid metal salts include metal salts of maleic acid and zinc, magnesium, calcium, etc.; stearic acid and zinc;
cadmium, barium, lead, iron, nickel, cobalt,
Metal salts with copper, aluminum, magnesium, etc.; dibasic lead stearate; oleic acid with zinc, magnesium,
Metal salts of iron, cobalt, copper, lead, calcium, etc.; metal salts of palmitic acid and aluminum, calcium, etc.; caprylates; lead caproate; metal salts of linoleic acid and zinc, cobalt, etc.; calcium ricinoleate ; Examples include metal salts of ricinoleic acid and zinc, cadmium, etc., and mixtures thereof. Examples of the fatty acid ester include ethyl maleate, butyl maleate, methyl stearate, butyl stearate, cetyl palmitate, and ethylene glycol montanate. Examples of the partially saponified fatty acid ester include partially saponified calcium esters of montanic acid. Examples of the higher fatty acids include dodecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid,
Mention may be made of linoleic acid, ricinoleic acid, arachidic acid, behenic acid, lignoceric acid, ceracoleic acid, etc. and mixtures thereof. Examples of the higher alcohol include dodecyl alcohol, lauryl alcohol, myristyl alcohol, palmityl alcohol, stearyl alcohol, aracyl alcohol, and behenyl alcohol. Examples of the paraffin wax include natural paraffin, microwax, synthetic paraffin, and chlorinated hydrocarbons. Examples of the amide waxes include stearic acid amide, oleic acid amide, palmitic acid amide, lauric acid amide, behenic acid amide, methylene bis stearamide, ethylene bis stearamide, N,N'-m-xylylene bis Stearic acid amide, N,N'-m-xylylenebis-12-hydroxystearic acid amide, N,N'-
Examples include isophthalic acid bis-stearylamide and N,N'-isophthalic acid bis-12-hydroxystearylamide. Examples of the polyhydric alcohol ester include glycerin stearate, glycerin ricinolate,
Examples include glycerin monobehenate, sorbitan monostearate, propylene glycol monostearate, sorbitan triolate, and the like. Examples of the silicone varnish include methyl silicone varnish, phenyl silicone varnish, and the like. Examples of the aliphatic fluorocarbons include low polymer compounds of tetrafluoroethylene and hexafluoropropylene, and fluorine-containing surfactants described in JP-A-53-124428.

However, in the production of capsule toner, when the outer shell is formed by interfacial polymerization or in-situ polymerization, compounds having functional groups capable of reacting with isocyanate groups such as the above-mentioned higher fatty acids and higher alcohols are frequently used. Doing so is not preferable because it inhibits shell formation and deteriorates the storage stability of the capsule toner.

The proportion of these anti-offset agents to the resin in the core material is preferably 1 to 20% by weight.

In the present invention, a coloring agent is contained in the core material of the capsule toner, and all dyes, pigments, etc. used in conventional toner coloring agents can be used.

Colorants used in the present invention include various carbon blacks produced by thermal black method, acetylene black method, channel black method, lamp black method, etc., and grafts in which the surface of carbon black is coated with resin. carbon black, phthalocyanine blue, permanent brown FG, brilliant first scarlet, pigment green B, rhodamine-B base, solvent red 49, solvent red 146, solvent blue 35, and mixtures thereof. Resin in material 100
About 1 to 15 parts by weight is used.

To produce a magnetic capsule toner, magnetic particles may be added to the core material. As magnetic particles,
For example, metals or alloys that exhibit ferromagnetism, such as ferrite, magnetite, iron, cobalt, and nickel, or compounds containing these elements, or materials that do not contain ferromagnetic elements but exhibit ferromagnetism through appropriate heat treatment. Alloys such as manganese-copper-aluminum,
Mention may be made of a type of alloy called Heusler alloy containing manganese and copper, such as manganese-copper-tin, or chromium dioxide, among others. These magnetic materials have an average particle size of 0
．． It is uniformly dispersed in the core material in the form of a fine powder of 1 to 1 μm. The content thereof is 20 to 70 parts by weight, preferably 30 to 70 parts by weight, per 100 parts by weight of the capsule toner.

[0066] When containing magnetic fine powder to make a magnetic toner, it may be treated in the same way as the colorant, but as it is, the affinity for organic substances such as core materials and monomers may be reduced. Since the magnetic powder has low properties, if the magnetic powder is used with or treated with a so-called coupling agent such as a titanium coupling agent, a silane coupling agent, or lecithin, the magnetic powder can be uniformly dispersed. Can be done.

[0067] Capsule toner is prepared by interfacial polymerization method or i
When produced by the n-situ polymerization method, the outer shell constituent material,
The core material constituent materials are dispersed in a dispersion medium, but the agglomeration of the dispersoid,
In order to prevent coalescence, it is necessary to contain a dispersion stabilizer in the dispersion medium.

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

Examples of the dispersion medium for the dispersion stabilizer include water, methanol, ethanol, propanol, butanol, ethylene glycol, glycerin, acetonitrile, acetone, isopropyl ether, tetrahydrofuran, and dioxane. It is also possible to use these alone or in combination.

Further, for the purpose of controlling the amount of charge, an appropriate amount of a charge control agent as exemplified above may be added to the outer shell material of the capsule toner according to the present invention, or this charge control agent may be mixed with the toner. However, since the chargeability is controlled by the charge control agent in the core material, even if it is added, the amount added can be small.

In the present invention, it is preferable that the main component of the heat-fusible core material in the capsule toner is a thermoplastic resin, and that the glass transition point derived from the resin is 10°C or more and 50°C or less. If the temperature is less than 10°C, the storage stability of the capsule toner deteriorates, and if it exceeds 50°C, the fixing strength of the capsule toner deteriorates, which is not preferable. In the present invention, the glass transition point refers to the extension of the baseline below the glass transition point and the rise of the peak when measured using a differential scanning calorimeter (manufactured by Seiko Electronics Industries, Inc.) at a heating rate of 10°C/min. The temperature at the intersection with the tangent line showing the maximum slope between the peak and the peak.

In the present invention, the softening point of the capsule toner is preferably 80° C. or higher and 150° C. or lower, but if it is lower than 80° C., the offset resistance deteriorates and 1
If the temperature exceeds 50° C., the fixing strength deteriorates, which is not preferable. In the present invention, the softening point refers to a 1 cm3 sample using a Koka type flow tester (manufactured by Shimadzu Corporation) at a heating rate of 6°C/
20kg by plunger while heating at min.
Apply a load of /cm2 and push out a nozzle with a diameter of 1 mm and a length of 1 mm. As a result, draw a flow tester's plunger drop amount (flow value) - temperature curve and let the height of the S-shaped curve be h. The temperature corresponding to h/2.

Although the particle size of the capsule toner in the present invention is not particularly limited, the average particle size is usually 3 to 30 μm. The thickness of the outer shell of the capsule toner is preferably 0.01 to 1 .mu.m. If it is less than 0.01 .mu.m, the blocking resistance will deteriorate, and if it exceeds 1 .mu.m, the thermal meltability will deteriorate, which is not preferable.

[0074] The capsule toner of the present invention may contain a fluidity improver, a cleanability improver, and the like, if necessary. Examples of fluidity improvers 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,
Examples include silicon carbide and silicon nitride. Particularly preferred is fine silica powder.

[0075] The fine silica powder is Si-O-Si
It is a fine powder having a bond, and may be produced by either a dry method or a wet method. In addition to anhydrous silicon dioxide, aluminum silicate, sodium silicate, potassium silicate, magnesium silicate, zinc silicate, etc. may be used, but those containing 85% by weight or more of SiO2 are preferred. In addition, silane coupling agents,
Fine silica powder surface-treated with a titanium-based coupling agent, silicone oil, silicone oil having an amine in its side chain, etc. can be used.

Examples of the cleaning performance improving agent include metal salts of higher fatty acids such as zinc stearate, and fine powder of fluorine-based polymers.

Further, additives for adjusting the developability, such as fine powder of a polymer of methyl methacrylate, may be used.

Furthermore, a small amount of carbon black may be used for color toning, resistance adjustment, etc. As carbon black, various conventionally known carbon blacks can be used, such as furnace black, channel black, and acetylene black.

When the capsule toner of the present invention contains fine magnetic powder, it can be used alone as a developer, and when it does not contain fine magnetic powder, it can be used as a developer.
A two-component developer can be prepared and used by mixing it with a carrier. The carrier is not particularly limited, but iron powder, ferrite, glass beads, etc., or resin-coated versions thereof may be used, and the mixing ratio of toner to carrier is 0.5 to 10% by weight. Further, the particle size of the carrier used is 30 to 500 μm.

The capsule toner of the present invention provides good fixing strength by fixing it on a recording material such as paper using a combination of heat and pressure. , a known heat roller fixing method, or, for example, as described in JP-A-2-190870, an unfixed toner image on a recording material is transferred through a heat-resistant sheet by a heating means composed of a heating section and a heat-resistant sheet. A fixing method that heats and melts the material and fixes it, or for example,
As described in Japanese Patent Publication No. 162356, the toner image is formed by a fixedly supported heating body and a pressure member that presses against the heating body and brings the recording material into close contact with the heating body through a film. A method of fixing the toner under heat and pressure on a recording material is suitable for fixing the capsule toner of the present invention.

[0081]

EXAMPLES Examples of the present invention will be described below, but the embodiments of the present invention are not limited to these examples.

Example 1 69.0 parts by weight of styrene, 31.0 parts by weight of 2-ethylhexyl acrylate, 0.9 parts by weight of divinylbenzene, and carbon black "#44" (manufactured by Mitsubishi Kasei Corporation) 7
．． 0 parts by weight, negatively chargeable charge control agent "Bontron S-3"
4'' (manufactured by Orient Chemical Co., Ltd.) 2.0 parts by weight, 2,2'
-Azobisisobutyronitrile 3.5 parts by weight, 4.4
'-Diphenylmethane diisocyanate 'Millio
nate MT” (manufactured by Nippon Polyurethane Kogyo Co., Ltd.)9.
5 parts by weight was added, put into an attritor (manufactured by Mitsui Miike Kakoki Co., Ltd.), and dispersed at 10° C. for 5 hours to obtain a polymerizable composition. This was added in an amount of 30% by weight to 800g of a 4% by weight aqueous colloidal solution of tricalcium phosphate prepared in advance in a 2 liter separable glass flask.
Using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), at 5°C
The mixture was emulsified and dispersed for 2 minutes at a rotation speed of 10,000 rpm. A four-mouthed glass lid, a reflux cooling tube, a thermometer,
A dropping funnel with a nitrogen introduction tube and a stainless steel stirring bar were attached and placed in an electric heating mantle. Resorcinol 2
Prepare a mixed solution of 2.0 g of diethyl malonate, 3.6 g of diethyl malonate, 0.5 g of 1,4-diazabicyclo[2.2.2] octane, and 40 g of ion-exchanged water, and add from the dropping funnel.
The mixture was added dropwise over 30 minutes while stirring. Thereafter, while stirring under nitrogen, the temperature was raised to 85° C., and the mixture was reacted for 10 hours. After cooling, the dispersant was dissolved in a 10% aqueous hydrochloric acid solution, filtered, washed with water, and heated to 20 mm at 45°C for 12 hours.
Dry under reduced pressure with Hg and classify with a wind classifier to obtain an average particle size of 9.
A capsule toner was obtained in which the outer shell was made of a resin having a heat-dissociable urethane bond.

To 100 parts by weight of this capsule toner, 0.4 parts by weight of hydrophobic silica fine powder "Aerosil R-972" (manufactured by Aerosil Co., Ltd.) was added and mixed to obtain a capsule 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 28.7°C, and the softening point of Toner 1 was 131.0°C.

Example 2 Made of 75 parts by weight of styrene and 25 parts by weight of n-butyl acrylate, softening point: 75.3°C, glass transition point: 40.5°C
100 parts by weight of copolymer of copper phthalocyanine "Su
mikaprintCyanine Blue GN-
O'' (manufactured by Sumitomo Chemical) 6 parts by weight, negatively chargeable charge control agent ``COPYCHARGE NX VP434'' (manufactured by Hoechst) 2.0 parts by weight, polypropylene wax ``
The mixture was premixed with 5 parts by weight of "Biscol 550p" (manufactured by Sanyo Chemical Co., Ltd.), melt-kneaded in a twin-screw extruder, cooled, and then pulverized. 40 parts by weight of this kneaded material, 50 parts by weight of styrene, 15 parts by weight of n-butyl acrylate, 2
, 2.5 parts by weight of 2'-azobis(2,4-dimethylvaleronitrile), "Takenate D-102", an adduct of 3 moles of 2,4-tolylene diisocyanate and 1 mole of trimethylolpropane (Takeda Pharmaceutical Company Limited) (manufactured by)9.
0 parts by weight and 0.5 parts by weight of xylylene-1,4-diisothiocyanate to obtain a polymerizable composition. This was added in an amount of 30% by weight to 800g of a 4% by weight aqueous colloidal solution of tricalcium phosphate prepared in advance in a 2-liter glass separable flask, and TK
Rotation speed: 10,000 rpm at 5°C using a homomixer
The mixture was emulsified and dispersed at m for 2 minutes.

[0085] A four-necked glass lid was attached, and a reflux condenser, a thermometer, a dropping funnel with a nitrogen introduction tube, and a stainless steel stirring rod were attached and placed in an electric heating mantle. 4-
Acetylcatechol 27.4g, dimethyl malonate 4
．． 0g, 1,2-ethanedithiol 0.8g, 1,4
-Diazabicyclo[2.2.2]octane 0.5g
A mixed solution of 40 g of ion-exchanged water was prepared and added dropwise from the dropping funnel over 30 minutes while stirring. after that,
While stirring under nitrogen, the temperature was raised to 85° C. and the reaction was allowed to proceed for 10 hours. After cooling, the dispersant was dissolved in a 10% aqueous hydrochloric acid solution, filtered, washed with water, and then heated at 45°C for 12 hours.
It was dried under reduced pressure at 0 mmHg and classified using an air classifier to obtain a capsule toner having an average particle size of 9 μm and an outer shell made of a resin having thermally dissociable bonds.

To 100 parts by weight of this capsule toner, 0.4 parts by weight of hydrophobic silica fine powder "Aerosil R-972" (manufactured by Aerosil Co., Ltd.) was added and mixed to obtain a capsule toner according to the present invention. This is referred to as toner 2. The glass transition point derived from the resin in the core material was 34.0°C, and the softening point of Toner 2 was 132.5°C.

Example 3 Carbon black "GP-E-3" grafted with styrene to 50 parts by weight of styrene, 35 parts by weight of 2-ethylhexyl acrylate, and 0.9 parts by weight of divinylbenzene.
(manufactured by Ryoyu Kogyo Co., Ltd.) 40 parts by weight, 1.5 parts by weight of 3-methyl-5-nitroimidazole as a negatively chargeable charge control agent, 4.5 parts by weight of lauroyl peroxide, tolylene diisocyanate "Coronate T-100" 9.0 parts by weight (manufactured by Nippon Polyurethane Kogyo Co., Ltd.) and 0.5 parts by weight of phenyl isocyanate were added to obtain a polymerizable composition.

[0088] This was added in an amount of 30% by weight to 800g of an aqueous colloidal solution containing 4% by weight of tricalcium phosphate prepared in advance in a 2-liter separable glass flask. Emulsification and dispersion was carried out using a rotary machine (manufactured by Kogyo Co., Ltd.) at 5° C. and a rotational speed of 10,000 rpm for 2 minutes. It was covered with a four-necked glass lid, and a reflux condenser, a thermometer, a dropping funnel with a nitrogen introduction tube, and a stainless steel stirring rod were attached and placed in an electric heating mantle. Resorcinol 24.0g, m-aminophenol 3.0g
A mixed solution of , 2.2 g of t-butyl alcohol, 0.5 g of 1,4-diazabicyclo[2.2.2] octane, and 40 g of ion-exchanged water was prepared and added dropwise from the dropping funnel over 30 minutes while stirring. Thereafter, the temperature was raised to 85°C while stirring under nitrogen, and the reaction was allowed to proceed for 10 hours. After cooling, dissolve the dispersant in 10% aqueous hydrochloric acid solution, filter,
After washing with water, it was dried at 45° C. for 12 hours under reduced pressure of 20 mmHg and classified using an air classifier to obtain a capsule toner having an average particle size of 9 μm and an outer shell made of a resin having thermally dissociable urethane bonds.

To 100 parts by weight of this capsule toner, 0.4 parts of hydrophobic silica fine powder "Aerosil R-972" was added.
Parts by weight were added and mixed to obtain a capsule toner according to the present invention. This is referred to as toner 3. The glass transition point derived from the resin in the core material is 32.0°C, and the softening point of toner 3 is 1
The temperature was 29.5°C.

Comparative Example 1 In Example 1, the negatively chargeable charge control agent “Bontron S
A capsule toner was obtained by performing the same operations as in Example 1 up to the surface treatment without using "-34". This is designated as comparison toner 1. The glass transition point derived from the resin in the core material is 28
．． 5°C, and the softening point of Comparative Toner 1 was 130.0°C.

Comparative Example 2 In Example 2, the negatively chargeable charge control agent "COPY C
A capsule toner was obtained by carrying out surface treatment in the same manner as in Example 2 without using "HARGE NXVP434". This is referred to as comparison toner 2. The glass transition point derived from the resin in the core material was 34.5°C, and the softening point of Comparative Toner 2 was 133.0°C.

Comparative Example 3 In Example 3, the negatively chargeable charge control agent 3-methyl-5
- A capsule toner was obtained by carrying out surface treatment in the same manner as in Example 3 without using nitroimidazole. This is referred to as comparison toner 3. The glass transition point derived from the resin in the core material is 32.0°C, and the softening point of comparative toner 3 is 13.
The temperature was 0.0°C.

Comparative Example 4 In Example 1, 22.0 g of resorcin and 3.6 g of diethyl malonate were replaced with 21.6 g of neopentyl glycol.
A capsule toner was obtained by performing the same operations as in Example 1 up to surface treatment. Compare this toner 4
shall be. The glass transition point derived from the resin in the core material is 28.
5°C, and the softening point of Comparative Toner 4 was 135.0°C.

10 parts of each of the toners obtained in the above Examples and Comparative Examples and 90 parts of styrene/methyl methacrylate resin-coated spherical ferrite powder having a particle size of 250 to 400 mesh were placed in a plastic container, and the mixture was heated at a rotation speed of 150.
The whole container was mixed by rotation on a roller at rpm for 20 minutes to prepare a developer.

The amount of charge was measured using a blow-off type charge amount measuring device described below. That is, it is a specific charge measuring device equipped with a Faraday cage, a capacitor, and an electrometer. First, W(g) (0.15 to 0.20 g) of the prepared developer was placed in a brass measurement cell equipped with a 500 mesh stainless steel mesh (the size can be changed as appropriate to prevent carrier particles from passing through). . Next, after suction was applied from the suction port for 5 seconds, blowing was performed for 5 seconds at a pressure indicated by the air pressure regulator of 0.6 kgf/cm2, and only the toner was removed from the cell. The voltage of the electrometer 2 seconds after the start of blowing at this time is V (volt)
And so. Here, assuming that the capacitance of the capacitor is C (μF), the specific charge Q/m of this toner can be obtained as shown in the following equation.

[0096]

[Math 1]

Here, m is the weight of the toner contained in the developer in W (g), the weight of the toner in the developer is T (g), and the weight of the developer is D (g). In this case, the toner concentration of the sample is expressed as T/D×100 (%), and m is determined as in the following formula.

[0098]

[Math 2]

Table 1 shows the results of measuring the amount of charge of the developer prepared under a normal environment. Further, a printing durability test was conducted under the following conditions, and Table 1 also shows the amount of charge after copying 50,000 sheets, the occurrence of scumming during the continuous printing durability test, and the state of scattering in the machine.

[0100] The fixing property was evaluated by the method described below. The above-prepared developer was used in a commercially available electrophotographic copying machine (the photoreceptor was selenium-based, the rotation speed of the fixing roller was 390
mm/sec, the heat pressure temperature in the fixing device was made variable, and the oil application device was removed). The fixing temperature was controlled at 100° C. to 220° C., and the fixing properties and offset properties of the image were evaluated. The results are shown in Table 2.

[0101] The minimum fixing temperature here is when the bottom surface is 15 mm.
Place a load of 500g on a ×7.5mm sand eraser,
The temperature of the fixing roller when the fixing rate exceeds 70% as defined below by rubbing the image fixed through the fixing device 5 times and measuring the optical reflection density with a Macbeth reflection densitometer before and after rubbing. means.

[0102]

[Math 3]

Regarding blocking resistance, each toner was left for 24 hours at 50° C. and 40% relative humidity, and the degree of aggregation was evaluated. The results are shown in Table 2.

[0104]

[Table 1]

[0105]

[Table 2]

As is clear from Table 1, toners 1 to 3 according to the present invention and comparative toner 4 have appropriate charge amount values, and even after 50,000 sheets of continuous copying, there is little change in charge amount and good image quality is maintained. was maintained. However, comparison toners 1 to 3 have low charge values, and the polarity reverses after 50,000 sheets have been copied, resulting in a lot of background smearing during continuous copying using these toners, and toner scattering inside the machine. I woke you up.

However, in Toners 1 to 3 and Comparative Toners 1 to 3, the outer shell of the capsule toner is made of a resin having a thermally dissociable bond, so as is clear from Table 2, the minimum fixing temperature is low and there is no offset. The range was wide, and there were no problems with blocking resistance. However, comparative toner 4 had no problems in the non-offset area and blocking resistance, but
The minimum fixing temperature was high.

Claims (7)

[Claims] Claim 1: Consisting of a heat-melting core material containing at least a colorant and one or more negatively chargeable charge control agents, and an outer shell provided to cover the surface of the core material. This is a capsule toner for heat and pressure fixing, and the main components of the outer shell are (1) monovalent isocyanate compounds and/or isothiocyanate compounds in an amount of 0 to 30 mol% of the total isocyanate compounds and/or isothiocyanate compounds;
) Divalent or higher isocyanate compounds and/or isothiocyanate compounds in an amount of 100 to 70 mol% of the total isocyanate compounds and/or isothiocyanate compounds.
and (3) 0 to 30 mol% of the total compound that reacts with isocyanate groups and/or isothiocyanate groups, (4) isocyanate groups and 100 of all compounds that react with isocyanate groups and/or isothiocyanate groups, including compounds having two or more active hydrogens that react with isothiocyanate groups
~70 mol% and the number of moles of (1) + (2) and (
3)+(4) in a molar ratio of 1:1 to 1:20, and among all the bonds involving isocyanate groups and/or isothiocyanate groups in the resin, A capsule toner for heat-pressure fixing, characterized in that at least 30% or more of the bonds are thermally dissociable. 2. The thermal pressure according to claim 1, wherein the bond exhibiting thermal dissociability is a bond derived from a reaction between a phenolic hydroxyl group and/or thiol group and an isocyanate group and/or isothiocyanate group. Capsule toner for fixing. 3. The thermoplastic resin according to claim 1, wherein the main component of the heat-fusible core material in the capsule toner is a thermoplastic resin, and the glass transition point derived from the resin is 10 to 50°C. Capsule toner for pressure fixing. Claim 4: The capsule toner has a softening point of 80 to 15.
The capsule toner for heat and pressure fixing according to claim 1, characterized in that the temperature is 0°C. 5. The compound having a phenolic hydroxyl group is one or more of the compounds represented by the following formula (I), the compound represented by the following formula (II), or the compound represented by the following formula (III). 3. The capsule toner for heat and pressure fixing according to claim 2. [Formula 1] (wherein R1, R2, R3, R4, R5 are independently H, or an alkyl group having 1 to 9 carbon atoms, an alkenyl group, an alkoxy group, an alkanoyl group, a carboalkoxy group, or an aryl group) (Indicates halogen.) [Formula 2] (In the formula, R6, R7, R8, R9 independently represent H
, or an alkyl group, alkenyl group, alkoxy group, alkanoyl group, carbalkoxy group, or aryl group having 1 to 6 carbon atoms, or a halogen. ) [Formula, R10, R11, R12, R13 are independently H, or an alkyl group having 1 to 6 carbon atoms, an alkenyl group, an alkoxy group, an alkanoyl group, a carboalkoxy group, an aryl group, or a halogen group. ) 6. The capsule toner for heat-pressure fixing according to claim 3, wherein the thermoplastic resin contained in the heat-fusible core material is mainly a vinyl resin. 7. The capsule toner for heat-pressure fixing according to claim 2, wherein the isocyanate group that reacts with the phenolic hydroxyl group is directly bonded to the aromatic ring.