JPH07301947A - Capsule toner for thermal pressure fixing - Google Patents

Abstract

PURPOSE:To obtain a toner excellent in anti-offset property and antiblocking property which can be fixed at low temp. to form a sharp image without fog for lots of times by specifying physical properties of the toner. CONSTITUTION:This toner is a capsule toner for thermal pressure fixing and which consists of a hot-melt core material containing a thermoplastic resin and a coloring agent and an outer shell which covers the surface of the core. The toner has the following physical properties. (l) The glass transition temp. due to the thermoplastic resin is 10-50 deg.C. (2) When load is applied under specified conditions for one particle of the toner with using a microcompression testing machine, the min. load to compress 5% of the particle size of the toner is 5-50mgf. The min. load to compress 10% of the particle size is 10-100mgf. (3) After the toner is left to stand for 24 hours at 50 deg.C, the difference of the toner aggregation degree before and after leaving is <=10. The aggregation degree of the toner is defined as the sum of calculations expressed by formula I to III by using a powder property measuring machine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat 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 or the like.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
The electrophotographic method includes U.S. Pat. Nos. 2,297,691 and 2,357.
No. 809, the photoconductive insulating layer is uniformly charged and then the layer is exposed to light to dissipate the charge on the exposed portion to form an electrical latent image. After being formed, and further visualized by adhering a fine powder having a colored charge called a toner to the latent image (developing step), after transferring the obtained visible image to a transfer material such as transfer paper (Transfer step), permanent fixing by heating, pressure or other suitable fixing method (fixing step). As described above, the toner must have the functions required not only in the developing step but also in the transfer step and the fixing step.

Generally, toner is subjected to a mechanical frictional force due to a shearing force and an impact force received during mechanical operation in a developing device,
It deteriorates during the copying of thousands to tens of thousands of sheets. To prevent such toner deterioration, a tough resin having a large molecular weight that can withstand mechanical friction may be used, but these resins generally have a high softening point and are a non-contact fixing method such as oven fixing and infrared fixing. In the radiant fixing method, the heat efficiency is poor and therefore the fixing is not sufficiently performed.Also, in the heat pressure fixing method which is widely used because the heat efficiency is good in the contact fixing method, it is necessary to fix the heat roller It is necessary to raise the temperature, which not only causes deterioration of the fixing device, curling of the paper, increase of energy consumption, etc., but also when such a resin is used, the pulverizability is poor,
When manufacturing a toner, the manufacturing efficiency is significantly reduced. Therefore, a binder resin having a too high degree of polymerization and a softening point cannot be used.

On the other hand, the heat pressure fixing method using a heat roller or the like has remarkably good thermal efficiency because the surface of the heat roller and the toner image surface of the sheet to be fixed are in pressure contact, and is widely used from low speed to high speed. When the surface and the toner image surface come into contact with each other, the toner tends to adhere to the surface of the heating roller and transferred to the subsequent transfer paper or the like, so-called offset phenomenon occurs. In order to prevent this phenomenon, the surface of the heating roller is processed with a material having an excellent releasing property such as a fluororesin, and a releasing agent such as silicone oil is applied to the surface of the heating roller to deal with the problem. However, the method of applying silicone oil or the like is not preferable because it easily causes a trouble because the fixing device becomes large and the cost becomes high, and it becomes complicated. Further, as described in JP-B-57-493, JP-A-50-44836, and JP-A-57-37353, there is a method of improving the offset phenomenon by asymmetrically or cross-linking the resin, but there is a fixing point. Has not been improved.

Generally, 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, and the minimum fixing temperature should be lowered as much as possible and the high temperature offset generation temperature should be as high as possible. By raising the temperature, the fixing temperature can be lowered and the usable temperature range can be widened, energy saving, high speed fixing and paper curl can be prevented. Therefore, there is always a demand for a toner having good fixability and offset resistance.

Conventionally, there has been proposed a technique for attaining 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. Among them, when a low melting point wax that is easily plastically deformed is used as the core material (US Pat. No. 3,26,26).
9,626, Japanese Patent Publication No. 46-15876, Japanese Patent Publication No. 44-9880, Japanese Unexamined Patent Publication No. 48-75032, Japanese Unexamined Patent Publication No. 48-75033), but fixing is possible only by pressure, but fixing strength is poor and limited. It can be used only for the intended purpose. Also, when using a liquid core material, if the strength of the shell material is low, fixing may occur only with pressure, but it may crack inside the developing device and stain the inside of the machine. A great deal of pressure is needed to destroy the, resulting in an image that is too glossy,
It was 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 high temperatures, but a resin having a low glass transition point which improves the fixing strength is used, and blocking resistance and the like are provided as an outer shell. For this purpose, a heat roller fixing capsule toner in which a resin wall having a high melting point is formed by interfacial polymerization has been devised. However, in JP-A-61-56352, the wall material has a high melting point,
Furthermore, since it is tough and hard to crack, the performance of the core material has not been fully achieved. Further, a heat roller fixing capsule toner having an improved fixing strength of a core material has been proposed in the same way (Japanese Patent Laid-Open Nos. 58-205162 and 58-2051).
63 publication, 63-128357 publication, 63-128358 publication,
63-128359, 63-128360, and 63-1283.
No. 61, 63-128362), the manufacturing method is a spray-drying method, which imposes a burden on the manufacturing equipment, and the shell material has not been devised so that the performance of the core material has not been fully drawn out. .

Further, in the capsule toner proposed in JP-A-63-281168, it is described that the shell material is thermotropic liquid crystal polyester, and in the capsule toner proposed in JP-A-4-184358. Although a crystalline polyester is used, since the polyester is not amorphous in all cases, the resin melts sharply, but the amount of energy required for melting is large, and the Tg of the core material is high, so the fixability is poor. .

As described above, capsule toners using various materials and manufacturing methods have been proposed, but they satisfy all requirements of sufficient low temperature fixing property, offset resistance and blocking resistance, and stress resistance in a developing machine. However, quantitative values have not been shown so far regarding the physical properties of the encapsulated toner that satisfies these performances.

The present invention has been made in view of the above circumstances, and its object is a heat pressure fixing system such as a heat roller, which has excellent offset resistance, can be fixed at low temperature, and has blocking resistance. An object of the present invention is to provide a heat-and-pressure fixing capsule toner having excellent properties and excellent stress resistance in a developing machine.

[0011]

DISCLOSURE OF THE INVENTION As a result of earnest research to solve the above problems, the present inventors have found that the relationship between the displacement amount and the load compressed when a load is applied to one particle of capsule toner, and Only when the value of cohesion degree satisfies a specific condition, there are sufficient low-temperature fixability, excellent blocking resistance, no collapse due to stress in the developing machine, and many clear images without background stains. The inventors have found that it is possible to provide a capsule toner for heat and pressure fixing that can be stably formed over a number of times, and have completed the present invention.

That is, the gist of the present invention is as follows: (1) A heat-fusible core material containing at least a thermoplastic resin and a colorant, and an outer shell provided so as to cover the surface of the core material. (1) A glass transition point derived from the thermoplastic resin which is the main component of the heat-fusible core material is 10 to 50 ° C., (2) When a load is applied to one particle of toner using the micro compression tester under the following conditions, the particle size of the toner particle is 5%.
The minimum load required to compress is 5 to 50 mgf,
And the minimum load required to compress 10% is 10-100
Micro compression tester: The upper pressing indenter is a flat indenter with a diameter of 50 μm made of diamond, and the lower pressing indenter is an SKS (alloy tool steel) flat plate at a temperature of 25 ° C. and a humidity of 50%. Load speed of load: 9. 1 mgf / sec (3) When the toner is left at 50 ° C. for 24 hours, the toner aggregation degree defined as the sum of the calculated values of the following formulas (a) to (c) obtained using a powder property measuring device The difference between the front and rear is 10 or less, the weight% of the toner remaining on the sieve having a sieve size of 250 μm × 1 (a) The weight% of the toner remaining on the sieve having a sieve size of 149 μm × 0.6, (b) the sieve size 74 μm % Toner remaining on the sieve (2) (c) (2) The heat and pressure fixing capsule toner according to (1), wherein the difference in toner cohesion before and after standing is 8 or less. (3) The capsule toner for heat and pressure fixing according to the above (1) or (2), wherein the capsule toner has a softening point of 70 to 150 ° C., and (4) the capsule toner is hydrophilic with an amorphous polyester as a main component. The capsule toner for heat and pressure fixing according to any one of (1) to (3) above, wherein the outer shell material is coated on the surface of the core material, and (5) the amorphous polyester is divalent or trivalent. One obtained by condensation polymerization of one or more alcohol monomers selected from the above alcohol monomers and one or more carboxylic acid monomers selected from divalent and trivalent carboxylic acid monomers Which is obtained by polycondensation using a monomer containing at least a trivalent or higher polyhydric alcohol monomer and / or a trivalent or higher polyvalent carboxylic acid monomer (4) Thermal pressure fixing power described Serutona relates.

The capsule toner for heat and pressure fixing of the present invention comprises
It has the following physical properties. First, the glass transition point derived from the thermoplastic resin which is the main component of the heat-meltable core material of the capsule toner is 10 to 50 ° C., preferably 12.5 to
The temperature is 47.5 ° C, more preferably 15 to 45 ° C. If it is lower than this range, the storage stability of the obtained toner tends to deteriorate, and if it exceeds this range, the fixing strength of the obtained toner tends to deteriorate.

Further, the heat and pressure fixing capsule toner of the present invention has the following physical properties of compressive displacement with respect to the load on the toner. The relationship between the load and the compression displacement with respect to one toner particle is, for example, a micro compression tester M manufactured by Shimadzu Corporation.
CTM-200 is used and it measures on condition of temperature 25 degreeC and humidity 50%. This tester includes an upper pressure indenter and a lower pressure indenter. The upper pressure indenter uses a flat indenter having a diameter of 50 μm made of diamond and the lower pressure indenter uses an SKS flat plate. The test conditions are as follows. 1. Type of test: Mode 3 (test for soft materials) 2. Sample shape: Particle mode 3. Load rate constant: 10 (load rate of load 9.1 mg
f / sec) The particle diameter is determined by averaging the horizontal and vertical directions with a length measuring device attached to the tester (observed by an optical microscope and actually measured). The measurement is performed for each toner particle, and the number of measurements is 1.
The data obtained by averaging the values 0 times or more is used. The obtained average value has high reproducibility and shows physical properties peculiar to each toner.

FIG. 1 shows a typical load-compressive displacement relationship obtained under the above conditions. First, in the rising portion of the area A in the graph, the toner is compressed almost linearly with the load, and then, as the area B, a point where an inflection point is taken in the vicinity of a certain load and the compression displacement largely changes. Appears. This means that the toner could not withstand the applied load and the toner was rapidly and greatly deformed. Finally, when the inflection point is reached again as the C region and the applied load is increased, the displacement is reduced, which means that the toner is completely crushed by the applied load. Therefore, in order to improve the low-temperature fixability, it is desired that the capsule be deformed under a lower load and the capsule be crushed. On the contrary, in order to withstand the stress in the developing machine, the toner should not be crushed by a certain load. There is a need.

Therefore, regarding the relationship between the load and the compressive displacement in the area A, the low temperature fixing property and the stress resistance in the developing machine,
Further detailed analysis revealed that the toner particle size was 5%.
The minimum load required for compression is 5 to 50 mgf, preferably 7.5 to 45 mgf, more preferably 10 to 40 m.
The minimum load required to compress the particle size of the toner particles by 10% is 10 to 100 mgf, preferably 15 to 90 mgf, and more preferably 20 to 80 mgf.
It was found that the above-mentioned problems can be satisfied by setting the above range.

When the minimum load required to compress the particle size of the toner particles by 5% or the minimum load required to compress the particle size by 10% is smaller than the above range, the stress in the developing machine causes There is a tendency that toner adhered matter is generated, toner is fused to the developing sleeve, and particularly in the case of two-component development, toner is fused to the carrier, and scumming and toner scattering tend to occur. If the minimum load required to compress the particle size by 5% or the minimum load required to compress the particle size by 10% is larger than the above range, sufficient low temperature fixability may not be obtained. .

The heat-pressure fixing capsule toner of the present invention has the following physical properties regarding the degree of aggregation of the toner.
That is, when the toner is left to stand at 50 ° C. for 24 hours, the difference between the toner cohesion before and after standing, which is defined as the sum of the calculated values of the following formulas (a) to (c) obtained using a powder property measuring device, It is 10 or less. Weight% of toner remaining on a sieve having a mesh size of 250 μm × 1 (a) Weight% of toner remaining on a sieve having a mesh size of 149 μm × 0.6 (b) Weight% of toner remaining on a sieve having a mesh size of 74 μm × 0.2 (c) In the present invention, the cohesion degree is measured using, for example, a powder tester manufactured by Hosokawa Micron Co., Ltd., a sieve having a diameter of 70 mm has a sieve having a diameter of 250 μm, and a sieve having a diameter of 149 μm has a sieve inside. A sieve having a mesh size of 74 μm is set at the bottom, and a vibration with an amplitude of 1 mm is applied to the table for 1 minute to perform the measurement.

As samples, 2 g of toner is weighed in an aluminum container and left in a dry oven at 50 ° C. for 24 hours, and toner before being left is used. The smaller the difference in the value of the cohesion degree between after standing for 24 hours at 50 ° C. and before standing, the higher the blocking resistance is. This means that in the heat-pressure fixing capsule toner of the present invention, If the difference is 10 or less, there is no problem in practical use. However, considering the long-term stability of the toner at high temperatures, the difference in the degree of aggregation is preferably 8 or less, more preferably 6 or less.

The heat and pressure fixing capsule toner of the present invention comprises
70-150 ° C. as the softening point, preferably 75-145
C., more preferably 80 to 140.degree. If it is lower than this range, the offset resistance of the toner tends to decrease, and if it is higher than this range, the fixing property of the toner tends to decrease.

The capsule toner of the present invention is not particularly limited to the core material, shell material, etc. of the capsule toner as long as it has the above-mentioned physical properties, but specific examples are as follows. Explained.

The capsule toner for heat and pressure fixing of the present invention comprises
It is preferable that the surface of the core material is coated with a hydrophilic outer shell material containing amorphous polyester as a main component. The amorphous polyester is usually one or more alcohol monomers (2
Valency, trivalence or more) and one or more carboxylic acid monomers (2
A polyhydric alcohol monomer having at least a trihydric or higher valence) and / or a polyhydric carboxylic acid monomer having a trihydric or higher valence. It is obtained by polycondensation.

Such an amorphous polyester is usually contained in an amount of 50 to 100% by weight based on the total weight of the outer shell, and other components contained in the outer shell include polyamide, polyester amide, polyurea and the like. 50% by weight can be used.

Examples of the dihydric alcohol component include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 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) -2,2-
Alkylene oxide adducts of bisphenol A such as 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 trihydric or higher alcohol components include sorbitol, 1,2,3,6-hexanetetrol, and 1,4.
-Sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,
4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene and the like can be mentioned. Trivalent alcohol is preferably used. In the present invention, these dihydric alcohol monomers and polyhydric alcohol monomers having a valence of 3 or more may be used alone or in combination.

The acid component is a carboxylic acid component and is a divalent monomer such as maleic acid, fumaric acid,
Citraconic acid, itaconic acid, glutaconic acid, phthalic acid,
Isophthalic acid, terephthalic acid, succinic acid, adipic acid,
Sebacic acid, azelaic acid, malonic acid, n-dodecenylsuccinic acid, n-dodecylsuccinic acid, n-octylsuccinic acid, isooctenylsuccinic acid, isooctylsuccinic acid,
And anhydrides of these acids, or lower alkyl esters.

Examples of the trivalent or higher carboxylic acid component include 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid and 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, pyromellitic acid, empol trimer acid and their acid anhydrides,
Lower alkyl ester and the like can be mentioned. Preferably 3
A valent carboxylic acid or its derivative is used. In the present invention, these divalent carboxylic acid monomers and 3
A single or a plurality of monomers may be used from the carboxylic acid monomers having a valency or higher.

The method for producing the amorphous polyester in the present invention is not particularly limited, and it can be produced by esterification or transesterification reaction using the above-mentioned monomer. Here, amorphous means a state having no definite melting point. In the present invention, when crystalline polyester is used, the amount of energy required for melting is large and the toner fixing property cannot be improved, which is not preferable.

The amorphous polyester used in the present invention preferably has a glass transition point of 50 to 80 ° C, more preferably 55 to 75 ° C. Fifty
If the temperature is less than ℃, the storage stability of the toner will be deteriorated,
If it exceeds, the fixability of the toner deteriorates. In the present invention, the glass transition point is a differential scanning calorimeter (manufactured by Seiko Denshi Kogyo Co., Ltd.) and is measured at a temperature rising rate of 10 ° C./min.
It is the temperature at the intersection of the extension line of the baseline below the glass transition point and the tangent line showing the maximum slope from the rising portion of the peak to the apex of the peak.

The acid value of the amorphous polyester is 3
It is preferably -50 (KOHmg / g), more preferably 10-30 (KOHmg / g). Three
If it is less than (KOHmg / g), it becomes difficult for the amorphous polyester as the shell material to come out to the interface during the in-situ polymerization, so that the storage stability of the toner becomes poor, and 50 (KOHmg / g)
If it exceeds g), the polyester tends to move into the aqueous phase, resulting in poor production stability. Here, the acid value is measured according to JIS
This is due to K0070.

The capsule toner having an outer shell made of amorphous polyester, which is preferably used in the present invention, is in situ.
It is produced by a known method such as a polymerization method. This capsule toner is composed of a heat-meltable core material containing at least a thermoplastic resin and a colorant, and an outer shell provided so as to cover the surface of the core material.

Examples of the resin used as the main component of the heat-meltable core material of the capsule toner in the present invention include thermoplastic resins such as polyester resin, polyester / polyamide resin, polyamide resin and vinyl resin, and preferably vinyl. Examples include resin. The glass transition point derived from the thermoplastic resin which is the main component of such a heat-meltable core material is preferably 10 to 50 ° C., and 20 to 45.
More preferably, the temperature is ° C. When the glass transition point is lower than 10 ° C, the storage stability of the capsule toner deteriorates, and when it exceeds 50 ° C, the fixing strength of the capsule toner deteriorates, which is not preferable.

Among the above-mentioned 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, vinylnaphthalene, etc., ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, isobutylene, etc., such as vinyl chloride,
Vinyl esters such as vinyl bromide, vinyl fluoride, vinyl acetate, vinyl propionate, vinyl formate, vinyl caproate, etc., such as 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, acrylic acid 2-
Hydroxyethyl, glycidyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, α-chloromethyl 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 such as ethylenic monocarboxylic acid substitution products such as acrylonitrile, methacrylonitrile, acrylamide, etc., such as ethylenic acid such as dimethyl maleate. Dicarboxylic acids and their substitution products, vinyl ketones such as vinyl methyl ketone, vinyl ethers such as vinyl methyl ether, vinylidene halides such as vinylidene chloride, eg N-
Examples thereof include N-vinyl compounds such as vinylpyrrole and N-vinylpyrrolidone.

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 monocarboxylic acid or its ester because the glass transition point of the resin for core material can be easily controlled.

When a cross-linking 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 diethylene. 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, tetramethylolmethane tetraacrylate, dibromoneopentyl glycol dimethacrylate, diallyl phthalate Appropriate agent (2 if necessary
A combination of two or more species can be used. Divinylbenzene and diethylene glycol diacrylate are preferably used.

The amount of these crosslinking agents used is 0.001 to 15% by weight, preferably 0.1 to 10% by weight, based on the polymerizable monomer. The amount of these crosslinkers used is 15
If it is more than 5% by weight, the toner is less likely to be melted by heat, resulting in poor heat fixing property or heat pressure fixing property. Also the amount used
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 adheres to the roller surface without being completely fixed to the paper and is transferred to the next paper in the heat and pressure fixing. Further, the above monomer may be polymerized in the presence of unsaturated polyester to give a graft or crosslinked polymer, which may be used as a resin for the core material.

Further, as the polymerization initiator used in producing the thermoplastic resin for the 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, dicumyl peroxide Examples thereof include peroxide-based polymerization initiators such as oxides.

Two or more kinds of polymerization initiators may be mixed and used for the purpose of controlling the molecular weight and the molecular weight distribution of the polymer or the reaction time. The amount of the polymerization initiator used is 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the polymerized monomer.

In the present invention, the colorant is contained in the core material of the capsule toner, but all the dyes, pigments and the like used in the conventional colorant for toner can be used. Examples of the colorant used in the present invention include various carbon blacks produced by a thermal black method, an acetylene black method, a channel black method, a lamp black method, etc., and a grafted carbon black obtained by coating the surface of the carbon black with a resin. , Nigrosine dye, Phthalocyanine Blue, Permanent Brown FG, Brilliant First Scarlet, Pigment Green B, Rhodamine-B
Base, Solvent Red 49, Solvent Red 146,
Solvent Blue 35, etc., and mixtures thereof can be mentioned, and usually 1 to 15 per 100 parts by weight of resin in the core material.
Parts by weight are used.

In the present invention, a charge control agent may be further added to the core material, and the negatively chargeable charge control agent to be added is not particularly limited and may be, for example, a metal-containing azo dye “Varifast”. Black 3804 "," Bontron S-31 "," Bontron S-32 "," Bontron S-34 "(above, manufactured by Orient Chemical Company)," T- "
77 "," Aizen Spyron Black TRH "(above,
(Hodogaya Chemical Co., Ltd.), copper phthalocyanine dyes, metal complexes of alkyl derivatives of salicylic acid, such as "Bontron E-81", "Bontron E-82", and "Bontron E".
-85 "(above, manufactured by Orient Chemical Co., Ltd.), a quaternary ammonium salt, for example," COPY CHARGE NX VP434 "(manufactured by Hoechst), a nitroimidazole derivative and the like can be mentioned. Preferably, T-77 and Eisenspiron Black TRH can be used.

The positively chargeable charge control agent is not particularly limited, and examples thereof include nigrosine dye "Nigrosine base EX", "oil black BS", "oil black SO", "bontron N-01", and "bontron". N-07 "," Bontron N-11 "(above, manufactured by Orient Chemical Co., Ltd.), triphenylmethane dye containing a tertiary amine as a side chain, quaternary ammonium salt compound, for example," Bontron P-51 "( Orient Chemical Co., Ltd.),
Cetyl trimethyl ammonium bromide, "COPY CHARG
Examples thereof include EPX VP435 "(manufactured by Hoechst) and the like, and polyamine resins such as" AFP-B "(manufactured by Orient Chemical Co.) and imidazole derivatives. Preferably, Bontron N-07 and AFP-B can be used. The above charge control agent is contained in the core material in an amount of 0.1 to 8.0% by weight, preferably 0.2 to 5.0% by weight.

In the core material, for the purpose of improving offset resistance in heat and pressure fixing, if necessary, for example, polyolefin, fatty acid metal salt, fatty acid ester, partially saponified fatty acid ester, higher fatty acid, higher alcohol, paraffin wax. Any one or more offset preventing agents such as amide wax, polyhydric alcohol ester, silicon varnish, aliphatic fluorocarbon, and silicone oil may be contained.

The above-mentioned 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 salt include maleic acid and zinc, magnesium,
Metal salts with calcium, etc .; Metal salts with stearic acid and zinc, cadmium, barium, lead, iron, nickel, cobalt, copper, aluminum, magnesium, etc .; Dibasic lead stearate; Oleic acid and zinc, magnesium, iron , Metal salts with cobalt, copper, lead, calcium, etc .; metal salts with palmitic acid, aluminum, calcium, etc .; caprylate; lead caproate; metal salts with linoleic acid, zinc, cobalt, etc .; calcium ricinoleate; Examples thereof include metal salts of ricinoleic acid and zinc, cadmium, and the like, and mixtures thereof. Examples of the fatty acid ester include maleic acid ethyl ester, maleic acid butyl ester, stearic acid methyl ester, stearic acid butyl ester, palmitic acid cetyl ester, montanic acid ethylene glycol ester and the like. Examples of the partially saponified fatty acid ester include partially saponified calcium of montanic acid ester. Examples of the higher fatty acid include dodecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, ricinoleic acid, arachidic acid, behenic acid, lignoceric acid, ceracoleic acid, and mixtures thereof. You can Examples of the higher alcohols include dodecyl alcohol, lauryl alcohol, myristyl alcohol, palmityl alcohol, stearyl alcohol, aralkyl alcohol, and behenyl alcohol. Examples of the paraffin wax include natural paraffin, microwax, synthetic paraffin, and chlorinated hydrocarbon. Examples of the amide wax include stearic acid amide, oleic acid amide, palmitic acid amide, lauric acid amide, behenic acid amide, methylenebisstearamide, ethylenebisstearamide, N, N'-m-xylylenebis. Examples thereof include stearic acid amide, N, N'-m-xylylenebis-12-hydroxystearic acid amide, N, N'-isophthalic acid bisstearylamide, and N, N'-isophthalic acid bis-12-hydroxystearylamide. Examples of the polyhydric alcohol ester include glycerin stearate,
Glycerin ricinoleate, glycerin monobehenate,
Examples thereof include sorbitan monostearate, propylene glycol monostearate and sorbitan trioleate. Examples of the silicon varnish include methyl silicon varnish and phenyl silicon varnish. Examples of the aliphatic fluorocarbon include low-polymerization compounds of tetrafluoroethylene and propylene hexafluoride, and fluorine-containing surfactants described in JP-A-53-124428. Of the above offset preventing agents, polyolefin is preferably used, and polypropylene is particularly preferably used. The ratio of these offset preventing agents to the resin in the core material is preferably 1 to 20% by weight.

The method for producing the capsule toner in the present invention will be described below. The toner of the present invention is not particularly limited as long as it is a method that can obtain the toner having the above-mentioned physical properties of compression displacement and agglomeration, and can be manufactured by a known method. Among them, the encapsulated toner of the present invention is in-situ in terms of simplification of manufacturing equipment and manufacturing process.
Polymerization methods are preferred. Hereinafter, the production method by the in situ polymerization method will be described as an example.

In this method, the heat-and-pressure capsule toner of the present invention is composed of a hot-melt core material containing at least a thermoplastic resin and a colorant, and an outer shell provided so as to cover the surface of the core material. Can be manufactured by the following steps (a) to (c). (A) a step of dissolving the shell constituent resin in a mixture containing a constituent monomer of the core resin, a polymerization initiator, and a colorant; and (b) an aqueous dispersion of the mixture obtained in the step (a). A step of obtaining a polymerizable composition by dispersing the shell-forming resin in the medium and unevenly distributing the outer shell-forming resin on the surface of the droplets of the core material constituting material; and (c) the polymerizable composition obtained in step (b). A step of polymerizing by an in situ polymerization method to form a core material whose surface is covered with an outer shell.

That is, in this manufacturing method, the outer shell is formed by dispersing a mixed liquid of a core constituent material and an outer shell constituent material composed of amorphous polyester in a dispersion medium, and the outer shell constituent material is the surface of a droplet. It can be performed by utilizing the property of being unevenly distributed. That is, the core material-constituting material and the outer shell-constituting material are separated from each other in the droplets of the mixed solution due to the difference in solubility index, and in this state, the polymerization proceeds to form a capsule structure. According to this method, since the outer shell is formed as a layer made of amorphous polyester having a substantially uniform thickness, the toner has a characteristic that the charging characteristics are uniform.

In the case of this method, it is necessary to contain a dispersion stabilizer in the dispersion medium in order to prevent aggregation and coalescence of dispersoids. 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 dodecylbenzene sulfonate, sodium tetradecyl sulfate, and pentadecyl sulfate. Sodium, sodium octyl sulfate, sodium allyl-alkyl-polyethersulfonate, sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate, calcium oleate, 3,3-disulfonediphenyl Urea-4,4-diazo-bis-amino-β-
Naphthol-6-sulfonate, 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 are used. can do. Two or more kinds of these dispersion stabilizers may be used in combination.

Examples of the dispersion medium of 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 individually or in mixture.

In the production method of the present invention, the amount of the amorphous polyester added 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.
It is more preferably 6 to 30 parts by weight. If it is less than 3 parts by weight, the film thickness of the outer shell becomes too thin and the storage stability deteriorates. If it exceeds 50 parts by weight, the viscosity becomes high and atomization becomes difficult and the production stability deteriorates.

In the present invention, the encapsulated toner obtained as described above may be used as a precursor particle, and a heat-pressure fixing encapsulated toner further subjected to seed polymerization may be used. Therefore, in the present invention, the encapsulated toner includes not only those obtained by the in situ polymerization method alone as described above but also those obtained by combining the in situ polymerization and the seed polymerization.

That is, seed polymerization is carried out by adding at least a vinyl polymerizable monomer and a vinyl polymerization initiator 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 components in the precursor particles are polymerized. For example, after the production of the precursor particles by the above-mentioned in situ polymerization method, at least the vinyl polymerizable monomer and the vinyl polymerization initiator are immediately added to the precursor particles in a suspended state so as to be absorbed in the precursor particles. Seed the monomer component in the particles
It 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 additionally, a crosslinking agent, an offset preventing agent, a charge control agent, etc. Can also be included.

The vinyl polymerizable monomer used in the seed polymerization may be the same as that used in the production of the above-mentioned precursor particles. Further, as the vinyl polymerization initiator, the cross-linking agent and the dispersion stabilizer, the same ones as those used in the production of the 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.
It is recommended to use 10% by weight. When the amount of these cross-linking agents used is more than 15% by weight, the toner obtained is less likely to be melted by heat, resulting in poor heat fixing property or heat pressure fixing property.
When the amount used is less than 0.001% by weight, it is difficult to prevent the offset phenomenon in which a part of the toner adheres to the roller surface without being completely fixed to the paper and is transferred to the next paper during thermal pressure fixing.

Further, in order to further improve the storage stability of the toner, the hydrophilic 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. Here, as the hydrophilic shell material, in addition to amorphous polyester, for example, a carboxyl group,
Examples thereof include a vinyl resin having a hydrophilic functional group such as an acid anhydride group, a hydroxyl group, an amino group, and an ammonium ion, an amorphous polyesteramide, an amorphous polyamide, and an epoxy resin. Such a water emulsion can be prepared by uniformly dispersing it with 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.
It is preferably (KOHmg / g), and more preferably 10 to 30 (KOHmg / g). 3 (KOH
If it is less than 100 mg / g), the amorphous polyester as the shell material is less likely to come out at the interface during seed polymerization, and the storage stability of the obtained toner is poor. Phase transition easily occurs and manufacturing stability deteriorates. Here, the acid value is measured according to JIS K007.
It is due to 0.

The water emulsion is added in an amount of 10 to 20 based on 100 parts by weight of the precursor particles.
Adjust so that it is 0 parts by weight. If it is less than 10 parts by weight, the fixing property is not improved, and if it exceeds 200 parts by weight, it becomes difficult to uniformly absorb the monomer in the precursor particles.

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

When 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 capsule 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 in terms of interface science. Further, the storage stability is further improved. In addition, since the polymerizable monomer of the core material can be polymerized in two stages (in situ polymerization reaction and seed polymerization reaction), the thermoplastic monomer in the core material can be further prepared by appropriately using a crosslinking agent. The molecular weight of the resin can be easily controlled, and the low temperature fixability and the offset resistance can be improved. In particular, it is possible to provide a toner suitable not only for high-speed fixing but also for low-speed fixing.

For the purpose of charge control, an appropriate amount of the charge control agent as exemplified above may be added to the outer shell material of the capsule toner of the present invention, or this charge control agent may be mixed with the toner. However, even if they are added, the addition amount can be small because the chargeability is controlled by the outer shell itself.

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 thickness of the outer shell of the capsule toner is 0.
01 to 1 μm is preferable, and if it is less than 0.01 μm, blocking resistance is deteriorated, and if it exceeds 1 μm, heat melting property is deteriorated, which is not preferable.

If desired, a fluidity improver, a cleaning property improver, etc. can be used in the capsule toner of the present invention. 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. Fine silica powder is particularly preferable.

The fine powder of silica is Si--O--Si.
It is a fine powder having a bond and may be produced by a dry method or a wet method. In addition to anhydrous silicon dioxide, aluminum silicate, sodium silicate,
It may be any of potassium silicate, magnesium silicate, zinc silicate, etc., but those containing 85% by weight or more of SiO ₂ are preferable. Further, a fine powder of silica surface-treated with a silane coupling agent, a titanium coupling agent, a silicone oil, a silicone 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 particles of fluorine-based high molecular weight particles. Further additives for adjusting the developability, for example, methacrylic acid methyl ester,
Fine particles of a polymer such as methacrylic acid butyl ester may be used. Further, a small amount of carbon black may be used for toning and resistance adjustment. As the carbon black, conventionally known ones, for example, various ones such as furnace black, channel black and acetylene black can be used.

The heat and pressure fixing capsule toner of the present invention comprises
When it contains magnetic fine powder, it is used alone as a developer, and when it does not contain magnetic fine powder, it is a non-magnetic one-component developer or a two-component system mixed with a carrier. The developer can be prepared and used. The carrier is not particularly limited, but iron powder,
Ferrite, glass beads, etc., or those coated with a resin thereof, as well as magnetite fine powder, resin carrier obtained by kneading ferrite fine powder into resin, and the like are used, and 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 heat-pressure fixing capsule toner of the present invention gives good fixing strength by fixing to a recording material such as paper by using heat and pressure together.
If heat and pressure are used in combination, a known heat roller fixing method, or an unfixed toner image on a recording material is heated by a heating section and a heat-resistant sheet, as described in, for example, JP-A-2-190870. By means of a fixing method in which the heat-melting sheet is heated and melted via the heat-resistant sheet to fix, or, for example, as described in JP-A-2-162356, a fixedly supported heating element, and the film is pressed against the heating element, and a film is formed. A method such as a method of heating and fixing the visible image of the toner on the recording material by a pressure member that brings the recording material into close contact with the heating body via the method is suitable for fixing the capsule toner of the present invention.

[0066]

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

Resin Production Example Propylene oxide adduct 36 of bisphenol A
7.5 g, bisphenol A ethylene oxide adduct 146.4 g, terephthalic acid 126.0 g, dodecenyl succinic anhydride 40.2 g, trimellitic anhydride 77.
7 g was placed in a glass 2-liter four-necked flask, equipped with a thermometer, a stainless stirrer, a downflow condenser, and a nitrogen introduction tube, and allowed to react at 220 ° C. in a mantle heater under a nitrogen stream. .

The degree of polymerization was traced from the softening point according to ASTM E28-67, and the reaction was terminated when the softening point reached 110 ° C. The resin thus obtained is referred to as Resin A.
Further, the glass transition point of the obtained resin was measured by a differential scanning calorimeter (“DSC220 type”, manufactured by Seiko Instruments Inc.), and it was 65 ° C. In addition, the softening point and the acid value were measured to be 110 ° C and 18 KOHmg / g, respectively.
Met. The acid value was measured by a method according to JIS K0070.

In the present invention, the softening point is a Koka type flow tester (manufactured by Shimadzu Corporation), and a sample of 1 cm ³ is heated at a heating rate of 6 ° C./min while a load of 20 kg / cm ² is applied by a plunger. Given, diameter 1mm, length 1
A nozzle of mm is pushed out, whereby a plunger drop amount (flow value) -temperature curve of the flow tester is drawn, and when the height of the S-shaped curve is h, the temperature corresponds to h / 2.

Example 1 65.0 parts by weight of styrene, 35.0 parts by weight of 2-ethylhexyl acrylate, 0.9 part by weight of divinylbenzene,
Carbon black "# 44" (manufactured by Mitsubishi Kasei) 7.0 parts by weight, charge control agent "T-77" (manufactured by Hodogaya Chemical Co., Ltd.) 1.0 part by weight, resin A 20.0 parts by weight, 2,2 '-Azobisisobutyronitrile (3.5 parts by weight) was added to an attritor ("MA-01SC type", manufactured by Mitsui Miike Kakoki Co., Ltd.) and dispersed at 10 ° C for 5 hours to give a polymerizable composition. I got a thing. Then, 240 g of the polymerizable composition was added to 560 g of an aqueous colloidal solution containing 4% by weight of tricalcium phosphate prepared in advance in a 2 liter glass separable flask, and the TK homomixer (“M type”, Tokushu Kika Kogyo Co., Ltd.) was added. 5) at 15 ° C. and a rotation speed of 12000 rpm.
It was emulsified and dispersed for a minute.

Next, a four-neck glass lid was attached, a reflux cooling tube, a thermometer, a nitrogen introduction tube, and a stainless steel stirring rod were attached and the lid was placed in an electric heating mantle heater. While continuing stirring under nitrogen, the temperature was raised to 85 ° C. and the reaction was performed for 10 hours. After cooling, the dispersion medium was dissolved with 440 ml of 1N hydrochloric acid aqueous solution, filtered, washed with water, and then at 45 ° C. for 12 hours.
It was dried under reduced pressure at 20 mmHg for an hour and classified by an air classifier to obtain a capsule toner having an outer shell of amorphous polyester having an average particle diameter of 8 μm.

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 a capsule toner of the present invention. This is designated as Toner 1. The glass transition point derived from the resin in the core material was 28.5 ° C, and the softening point of Toner 1 was 118.3 ° C.

Example 2 65.0 parts by weight of styrene, 35.0 parts by weight of 2-ethylhexyl acrylate, 6.0 parts by weight of 2,2'-azobisisobutyronitrile, 15.0 parts by weight of resin A and carbon black 7.0 parts by weight of "# 44" (manufactured by Mitsubishi Kasei Co., Ltd.) and 1.0 part by weight of a charge control agent "T-77" were added, and an attritor ("MA-01SC type", manufactured by Mitsui Miike Kakoki Co., Ltd.) And was dispersed at 10 ° C. for 5 hours to obtain a polymerizable composition.
Then, 240 g of the above polymerizable composition was added to 560 g of an aqueous colloidal solution containing 4% by weight of tricalcium phosphate prepared in advance in a 2 liter glass separable flask, and the TK homomixer (“M type”, special (Manufactured by Kika Kogyo Co., Ltd.) and emulsified and dispersed for 2 minutes at a rotation speed of 10,000 rpm at room temperature.

Then, a 4-port glass lid was attached, a reflux cooling tube, a thermometer, a nitrogen introduction tube, and a stainless steel stirring rod were attached, and the glass was placed in an electric heating mantle heater. While continuing stirring under nitrogen, the temperature was raised to 85 ° C. as the first-stage polymerization, and the reaction was carried out for 10 hours to obtain seed particles. This was cooled to room temperature to obtain precursor particles.

Then, in an aqueous suspension of the precursor particles,
Ultrasonic oscillator (US-150, Nippon Seiki Co., Ltd.)
13.0 parts by weight of styrene, 7.0 parts by weight of 2-ethylhexyl acrylate, 0.4 parts by weight of 2,2'-azobisisobutyronitrile, 0.22 of divinylbenzene
40.7 parts by weight of a water emulsion comprising 10 parts by weight, sodium lauryl sulfate 0.1 part by weight, charge control agent "T-77" 1.0 part by weight, and water 20 parts by weight, and the precursor particles are added. Swollen. Immediately after the dropping, observation with an optical microscope revealed that no emulsion droplets were observed and that swelling was completed within an extremely short time. Then, while continuing stirring under nitrogen, the temperature was raised to 85 ° C. and reacted for 10 hours as the second stage polymerization. After cooling, the dispersion medium is dissolved with a 10% aqueous hydrochloric acid solution, filtered, washed with water, and air-dried.
The mixture was dried at 20 ° C. for 12 hours under reduced pressure at 20 mmHg and classified by an air classifier to obtain a capsule toner having an outer shell of amorphous polyester having an average particle diameter of 8 μm.

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 a capsule toner of the present invention. This is designated as toner 2. The glass transition point derived from the resin in the core material is 25.4, and the toner 2
Had a softening point of 105.6 ° C.

Example 3 65.0 parts by weight of styrene, 35.0 parts by weight of 2-ethylhexyl acrylate, 6.0 parts by weight of 2,2'-azobisisobutyronitrile, 0.8 parts by weight of divinylbenzene, charge control 15.0 parts by weight of Resin A is added to 1.0 parts by weight of Agent "T-77" to dissolve Resin A. After the resin A is dissolved, grafted carbon black “GPE-3” 20.
0 part by weight was added and dispersed by a magnetic stirrer for 1 hour to obtain a polymerizable composition. Then, 240 g of the above polymerizable composition was added to 560 g of an aqueous colloidal solution containing 4% by weight of tricalcium phosphate prepared in a 2 liter glass separable flask and emulsified and dispersed using a TK homomixer. .

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

Then, in an aqueous suspension of the precursor particles,
26.0 parts by weight of styrene prepared by an ultrasonic oscillator, 2
-Ethylhexyl acrylate 14.0 parts by weight, 2,2'-
Azobisisobutyronitrile 1.6 parts by weight, divinylbenzene 0.8 parts by weight, sodium lauryl sulfate 0.2 parts by weight, charge control agent "T-77" 1.0 parts by weight, water 80.
122.6 parts by weight of an emulsion solution consisting of 0 parts by weight was added dropwise, and while continuing stirring under nitrogen, the temperature was raised to 85 ° C. as a second stage polymerization and reacted for 10 hours. After cooling 1
The dispersion medium is dissolved in a 0% hydrochloric acid aqueous solution, filtered, washed with water, air-dried, dried under reduced pressure at 20 mmHg at 45 ° C. for 12 hours, and then classified by an air classifier, and an outer shell having an average particle diameter of 8 μm is amorphous. A high quality polyester capsule toner was obtained.

To 100 parts by weight of this capsule 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 designated as toner 3. The glass transition point derived from the resin in the core material was 31.6 ° C., and the softening point of Toner 3 was 117.0 ° C.

Example 4 65.0 parts by weight of styrene, 35.0 parts by weight of 2-ethylhexyl acrylate, 6.0 parts by weight of 2,2'-azobisisobutyronitrile, 0.8 parts by weight of divinylbenzene, charge control 15.0 parts by weight of Resin A is added to 1.0 parts by weight of Agent "T-77" to dissolve Resin A. After the resin A was dissolved, 20 parts by weight of grafted carbon black "GPE-3" was added and dispersed for 1 hour with a magnetic stirrer to obtain a polymerizable composition. Then, 240 g of the above polymerizable composition was added to 560 g of an aqueous colloidal solution containing 4% by weight of tricalcium phosphate prepared in a 2 liter glass separable flask and emulsified and dispersed using a TK homomixer. .

Next, a 4-port glass lid was attached, a reflux condenser, a thermometer, a nitrogen inlet tube, and a stainless steel stirring rod were attached, and the apparatus was placed in an electric heating mantle heater, and stirring was continued under nitrogen. While raising the temperature to 85 ° C. and performing a polymerization reaction for 10 hours to form seed particles, the particles were cooled to room temperature to obtain precursor particles.

Then, in an aqueous suspension of the precursor particles,
26.0 parts by weight of styrene prepared by an ultrasonic oscillator, 2
-Ethylhexyl acrylate 14.0 parts by weight, 2,2'-
Emulsion composed of 2.4 parts by weight of azobisisobutyronitrile, 0.8 part by weight of divinylbenzene, 0.2 part by weight of sodium lauryl sulfate, 1.0 part by weight of the charge control agent "T-77", and 80 parts by weight of water. 123.4 parts by weight of the solution was added dropwise, and while continuing stirring under nitrogen, the temperature was raised to 85 ° C. and reacted for 10 hours as the second stage polymerization. 10% after cooling
The dispersion medium is dissolved in an aqueous solution of hydrochloric acid, filtered, washed with water, air-dried, and then dried under reduced pressure at 20 mmHg at 45 ° C. for 12 hours.
The particles were classified by an air classifier to obtain a capsule toner having an average particle diameter of 8 μm and an outer shell made of amorphous polyester.

To 100 parts by weight of this 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 designated as toner 4. The glass transition point derived from the resin in the core material was 32.0 ° C, and the softening point of Toner 4 was 115.2 ° C.

Comparative Example 1 70.0 parts by weight of styrene, 30.0 parts by weight of 2-ethylhexyl acrylate, 1.0 part by weight of divinylbenzene,
Carbon black "# 44" (manufactured by Mitsubishi Kasei) 10.0
Parts by weight 2,2'-azobisisobutyronitrile 4.0 parts by weight 4,4'-diphenylmethane diisocyanate "Millio
nate MT "(manufactured by Nippon Polyurethane Industry Co., Ltd.) was added thereto, and the mixture was 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 800 g of an aqueous colloidal solution of 4% by weight tricalcium phosphate prepared in a glass separable flask having a volume of 2 liters, and T
Using a K homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), the mixture was emulsified and dispersed at 5 ° C. and a rotation speed of 10,000 rpm for 2 minutes.

Next, a four-neck glass lid was attached, a reflux condenser, a thermometer, a dropping funnel with a nitrogen inlet tube, and a stainless steel stirring rod were attached, and it was placed in an electric heating mantle heater. Prepare a mixed solution of 22.0 g of resorcin, 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 drop over 30 minutes with stirring from a dropping funnel. did. Then, while stirring under nitrogen, raise the temperature to 80 ° C,
Reacted for 10 hours. After cooling, 1N hydrochloric acid aqueous solution 650
Dissolve the dispersant in ml, filter, wash with water, dry under reduced pressure at 20 mmHg for 12 hours at 45 ° C., classify with an air classifier, and the outer shell having an average particle size of 9 μm has a thermally dissociable urethane bond. A resin capsule toner was obtained. This is designated as comparative toner 1. The glass transition point derived from the resin in the core material is 30.2 ° C., and the softening point of Comparative Toner 1 is 13
It was 0.0 ° C.

Comparative Example 2 Styrene 69.0 parts by weight, 2-ethylhexyl acrylate 31.0 parts by weight, divinylbenzene 0.9 parts by weight,
To 7.0 parts by weight of carbon black "# 44" (manufactured by Mitsubishi Kasei Co., Ltd.), 20.0 parts by weight of Resin A and 3.5 parts by weight of 2,2'-azobisisobutyronitrile were added, and an attritor (" MA-01SC type ", manufactured by Mitsui Miike Kakoki Co., Ltd.) and dispersed at 10 ° C for 5 hours to obtain a polymerizable composition. Then, 240 g of the polymerizable composition was added to 560 g of an aqueous colloidal solution containing 4% by weight of tricalcium phosphate, which had been prepared in advance in a 2 liter glass separable flask.
Using a homomixer (“M type”, manufactured by Tokushu Kika Kogyo Co., Ltd.), emulsion dispersion was performed at 15 ° C. and a rotation speed of 12000 rpm for 5 minutes.

Next, a 4-port glass lid was attached, a reflux cooling tube, a thermometer, a nitrogen introducing tube, and a stainless steel stirring rod were attached, and the glass was placed in an electric heating mantle heater. While continuing stirring under nitrogen, the temperature was raised to 85 ° C. and the reaction was performed for 10 hours. After cooling, the dispersion medium is dissolved with a 10% hydrochloric acid aqueous solution, filtered, washed with water, and then at 45 ° C. for 12 hours, 2 hours.
It was dried under reduced pressure at 0 mmHg and classified by an air classifier to obtain a capsule toner having an outer shell of amorphous polyester with an average particle diameter of 8 μm.

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 a capsule toner. This is designated as comparative toner 2. The glass transition point derived from the resin in the core material was 30.6 ° C, and the softening point of comparative toner 2 was 125.5 ° C.

Comparative Example 3 56.0 parts by weight of styrene, 44.0 parts by weight of 2-ethylhexyl acrylate, 0.9 part by weight of divinylbenzene,
To 7.0 parts by weight of carbon black "# 44" (manufactured by Mitsubishi Kasei Co., Ltd.), 20.0 parts by weight of Resin A and 3.5 parts by weight of 2,2'-azobisisobutyronitrile were added, and an attritor (" MA-01SC type ", manufactured by Mitsui Miike Kakoki Co., Ltd.) and dispersed at 10 ° C for 5 hours to obtain a polymerizable composition. Then, 240 g of the polymerizable composition was added to 560 g of an aqueous colloidal solution containing 4% by weight of tricalcium phosphate, which had been prepared in advance in a 2 liter glass separable flask.
Using a homomixer (“M type”, manufactured by Tokushu Kika Kogyo Co., Ltd.), emulsion dispersion was performed at 15 ° C. and a rotation speed of 12000 rpm for 5 minutes.

Next, a four-necked glass lid was attached, a reflux cooling tube, a thermometer, a nitrogen introduction tube, and a stainless steel stirring rod were attached and the lid was placed in an electric heating mantle heater. The temperature was raised to 85 ° C. while continuing stirring under nitrogen, and the reaction was performed for 10 hours. After cooling, dissolve the dispersion medium with a 10% aqueous hydrochloric acid solution, filter and wash with water, then at 20 ° C. for 20 hours at 45 ° C.
It was dried under reduced pressure at mHg and classified by an air classifier to obtain a capsule toner having an outer shell of amorphous polyester having an average particle diameter of 8 μm.

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 a capsule toner. This is designated as comparative toner 3. The glass transition point derived from the resin in the core material is 20.4 ° C., and the comparison toner 3
Had a softening point of 101.5 ° C.

Comparative Example 4 69.0 parts by weight of styrene, 31.0 parts by weight of 2-ethylhexyl acrylate, 6.0 parts by weight of 2,2'-azobisisobutyronitrile, 15.0 parts by weight of Resin A and carbon black. 7.0 parts by weight of "# 44" (manufactured by Mitsubishi Kasei Co., Ltd.) was added, and the mixture was put into an attritor ("MA-01SC type", manufactured by Mitsui Miike Kakoki Co., Ltd.), dispersed at 10 ° C for 5 hours, and polymerized. A sex composition was obtained. Then, in a 2 liter glass separable flask, 4% by weight of tricalcium phosphate prepared in advance.
240 g of the above-mentioned polymerizable composition was added to 560 g of the aqueous colloidal solution, and the rotation speed was 10,000 at room temperature using a TK homomixer (“M type”, manufactured by Tokushu Kika Kogyo Co., Ltd.).
Emulsified and dispersed at rpm for 2 minutes.

Then, a 4-port glass lid was attached, a reflux condenser, a thermometer, a nitrogen inlet tube, and a stainless steel stirring rod were attached, and the lid was placed in an electric heating mantle heater. While continuing stirring under nitrogen, the temperature was raised to 85 ° C. as the first-stage polymerization, and the reaction was carried out for 10 hours to obtain seed particles. This was cooled to room temperature to obtain precursor particles.

Then, in an aqueous suspension of the precursor particles,
Ultrasonic oscillator (US-150, Nippon Seiki Co., Ltd.)
13.0 parts by weight of styrene, 7.0 parts by weight of 2-ethylhexyl acrylate, 0.4 parts by weight of 2,2'-azobisisobutyronitrile, 0.22 of divinylbenzene
Parts by weight, sodium lauryl sulfate 0.1 parts by weight, water 20
40.7 parts by weight of a water emulsion consisting of parts by weight was dropped to swell the precursor particles. Immediately after the dropping, observation with an optical microscope revealed that no emulsion droplets were observed and that swelling was completed within an extremely short time.
Then, while continuing stirring under nitrogen, the temperature was raised to 85 ° C. and reacted for 10 hours as the second stage polymerization. After cooling, 1
The dispersion medium is dissolved in a 0% hydrochloric acid aqueous solution, filtered, washed with water, air-dried, dried under reduced pressure at 20 mmHg at 45 ° C. for 12 hours, and then classified by an air classifier, and an outer shell having an average particle diameter of 8 μm is amorphous. A high quality polyester capsule toner 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 a capsule toner. This is designated as comparative toner 4. The glass transition point derived from the resin in the core material is 27.4, and Comparative Toner 4
Had a softening point of 108.2 ° C.

Test Example 6 parts by weight of each of the toners obtained in the above Examples and Comparative Examples and 94 parts by weight of spherical ferrite powder coated with a styrene / methylmethacrylate resin having a particle size of 250 mesh to 400 mesh were placed in a poly container. Put in, the rotation speed is 150r
The developer was prepared by tumbling the entire container on a roller for 20 minutes at pm. The obtained developer was evaluated for charge amount, printing durability, fixing property, compression displacement, and degree of aggregation by the methods described below. Table 1 shows the glass transition point and softening point of these toners.

[0098]

[Table 1]

(1) The charge amount was measured by a blow-off type charge amount measuring device described below. That is,
Using a specific charge measuring device equipped with a Faraday cage, a condenser, and an electrometer, first, 500 mesh
W (g) (0.15 to 0.20 g) of the prepared developer was put in a brass measuring cell equipped with a stainless mesh (which can be appropriately changed to a size in which carrier particles do not pass). Next, after suctioning for 5 seconds from the suction port, the air pressure regulator is 0.6 kgf.
Blow was performed for 5 seconds at a pressure indicating / 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 defined as V (volt). If the electric capacity of the condenser is C (μF), the specific charge of this toner is Q / m.
Is calculated by the following formula. 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 in the developer is T (g), When the weight of the agent is D (g), the toner concentration of the sample is T / D
It is expressed as × 100 (%), and m is calculated by the following formula. m (g) = W × (T / D)

Table 2 shows the result of measurement of the charge amount of the developer prepared under the normal environment. As for printing durability, in the case of commercially available electrophotographic copying machines (Toners 1 and 2 and comparative toners 2, 3, and 4, the photoconductor is selenium-arsenic, the rotation speed of the fixing roller is 255 mm / sec, and the toners 3 and 4 are the same). In this case, the photoconductor is also selenium-arsenic, and the rotation speed of the fixing roller is 80 mm.
/ Sec, in the case of Comparative Toner 1, an organic photoconductor was used, the fixing roller rotation speed was 255 mm / sec, and continuous printing durability evaluation was performed on 10,000 sheets to evaluate the image quality (background stain, generation of black spots), The results are shown in Table 2.

[0101]

[Table 2]

(2) The fixability was evaluated by the method described below. That is, the prepared developer described above is used as a commercially available electrophotographic copying machine (toner 1, 2 and comparative toner 2, 3,
In the case of No. 4, the photoconductor is selenium-arsenic, the rotation speed of the fixing roller is 255 mm / sec, and in the case of Toners 3 and 4, the photoconductor is selenium-arsenic and the rotation speed of the fixing roller is 8 mm.
0 mm / sec, in the case of comparative toner 1, an organic photoconductor is used, and the rotation speed of the fixing roller is 255 mm / sec. Further, the heat and pressure temperature in the fixing device was made variable, and the image was output using the one in which the oil coating device was removed). The fixing temperature was controlled from 70 to 220 ° C., and the fixing property and offset property of the image were evaluated. The results are shown in Table 3.

The minimum fixing temperature here means that the bottom surface is 15 mm ×
Apply a load of 500 g to a 7.5 mm sand eraser, rub the image fixed five times through the fixing machine, and before rubbing, measure the optical reflection density with a Macbeth reflection densitometer, and fix according to the definition below. The temperature of the fixing roller when the rate exceeds 70%. Fixing rate = (image density after rubbing / image density before rubbing)

The offset resistance was evaluated by measuring the low temperature offset disappearance temperature and the high temperature offset generation temperature. That is, the temperature of the heat roller surface is 70 to 240
A copy test was conducted by raising the temperature by 5 ° C. in the range of 0 ° C., and the adhesion of the toner on the surface of the heat roller was visually evaluated at each temperature.

(3) The compression displacement was evaluated by the method described below. That is, a micro compression tester MCTM-200 manufactured by Shimadzu Corporation is used, and the temperature is 25 ° C. and the humidity is 50.
% Was measured. The upper pressure indenter is a flat indenter with a diameter of 50 μm made of diamond, and the lower pressure indenter is S
A KS flat plate was used. The test conditions were as follows. 1. Type of test: Mode 3 (test for soft materials) 2. Sample shape: Particle mode 3. Load rate constant: 10 (load rate of load 9.1 mg
f / sec) The particle diameter was determined by averaging the horizontal and vertical directions with a length measuring device attached to the tester (observed by an optical microscope and actually measured). The measurement is performed for each toner particle, and the number of measurements is 1.
The data was used 0 times or more and the averaged data was used. In addition, when there is no data of exactly 5% displacement and 10% displacement of the particle size, the average value of the data before and after that was used. The results obtained are shown in Table 3.

[0106]

[Table 3]

(4) The degree of aggregation was evaluated by the method described below. That is, 2 g of toner was weighed in an aluminum container and left in a dry oven at 50 ° C. for 24 hours. Using a powder tester manufactured by Hosokawa Micron Co., Ltd., the mesh size is 25
Set 0 μm sieve on top, 149 μm sieve on inside, and 74 μm sieve on bottom, and for 1 min.
Vibration was applied to the table with an amplitude of 1 mm, and the samples before and after standing were measured. The sum of the calculated values of the following formulas (a) to (c) was calculated as the toner cohesion degree, and the difference between the values before and after leaving was evaluated. The results obtained are shown in Table 4. Weight% of toner remaining on a sieve having a mesh size of 250 μm × 1 (a) Weight% of toner remaining on a sieve having a mesh size of 149 μm × 0.6 (b) Weight% of toner remaining on a sieve having a mesh size of 74 μm × 0.2 (c)

The long-term storage stability was evaluated by the method described below. That is, 200 g of toner is weighed in an aluminum container and dried in a dry oven at 45 ° C. for 2 weeks.
A printing test was conducted in the same manner as the printing durability test using the toner left for one month or two months. Long-term storage stability was evaluated by the degree of cohesion. The results are also shown in Table 4. In Table 4, "poor" means that black spots were generated due to aggregation.

[0109]

[Table 4]

In Examples 1 to 4, since the difference between the load until the particles are displaced by 5% and 10% of the particle diameter and the value of the cohesion degree are in an appropriate range, the fixing property and blocking resistance are excellent. Even after printing 10,000 sheets, a good image was obtained without generation of black spots and background stain due to stress in the developing machine. On the other hand, in Comparative Examples 1 and 2, 5% of particle size and 1
Since the load until 0% compression was large, there was no generation of black spots and scumming due to stress in the developing machine, but the fixability was inferior to Examples 1 to 4. Also,
In Comparative Example 3, the fixability was good because the load until the particles were compressed by 5% and 10% of the particle size was small, but 20
After 00 sheets, black spots which appeared to be background stains and adhered toner were generated on the image. Further, in Comparative Example 4, the particle size of 5
% And 10% of the load is in an appropriate range, the fixing property is excellent, but the long-term storage stability is poor because the difference in the cohesion value is large. On the other hand, the toners of Examples 1 to 4 had a small difference in the value of the degree of aggregation and were particularly excellent in long-term stability.

[0111]

EFFECT OF THE INVENTION According to the encapsulated toner for heat and pressure fixing of the present invention, it has excellent offset resistance in a heat and pressure fixing method such as a heat roller, can be fixed at a low temperature, has excellent blocking resistance, and is free from fog. A clear image can be stably formed many times.

[Brief description of drawings]

FIG. 1 shows a typical relationship between load and compressive displacement of a capsule toner of the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kuniyasu Kawabe 1334 Minato Minato, Wakayama City Kao Research Institute

Claims (5)

[Claims] 1. A heat-meltable core material containing at least a thermoplastic resin and a colorant, and an outer shell provided so as to cover the surface of the core material, and have the following physical properties. Capsule toner for heat and pressure fixing. (1) The glass transition point derived from the thermoplastic resin, which is the main component of the heat-fusible core material, is 10 to 50 ° C. (2) The following conditions for one particle of toner using a micro compression tester When a load is applied with, the particle size of the toner particles is 5%
The minimum load required to compress is 5 to 50 mgf,
And the minimum load required to compress 10% is 10-100
Micro compression tester: The upper pressing indenter is a flat indenter with a diameter of 50 μm made of diamond, and the lower pressing indenter is an SKS (alloy tool steel) flat plate at a temperature of 25 ° C. and a humidity of 50%. Load speed of load: 9. 1 mgf / sec. (3) When the toner is left at 50 ° C. for 24 hours, the toner aggregation degree defined as the sum of the calculated values of the following formulas (a) to (c) obtained using a powder property measuring device is left. The difference between the front and rear is 10 or less, the weight% of the toner remaining on the sieve having a sieve size of 250 μm × 1 (a) The weight% of the toner remaining on the sieve having a sieve size of 149 μm × 0.6, (b) the sieve size 74 μm % Of toner remaining on the screen of 0.2 × (c) 2. The heat and pressure fixing capsule toner according to claim 1, wherein the difference in toner cohesion before and after leaving is 8 or less. 3. The softening point of the capsule toner is 70 to 150.
3. The capsule toner for heat and pressure fixing according to claim 1, which has a temperature of ° C. 4. The heat and pressure fixing capsule according to claim 1, wherein the capsule toner is obtained by coating the surface of a core material with a hydrophilic outer shell material containing amorphous polyester as a main component. toner. 5. The amorphous polyester is selected from at least one alcohol monomer selected from divalent and trivalent or more alcohol monomers, and divalent and trivalent or more carboxylic acid monomers. A monomer obtained by polycondensation of one or more carboxylic acid monomers, containing at least a trivalent or higher polyhydric alcohol monomer and / or a trivalent or higher polyvalent carboxylic acid monomer The encapsulated toner for heat and pressure fixing according to claim 4, which is obtained by polycondensation using a body.