JPS59137958A - Manufacture of encapsulated toner - Google Patents

Abstract

PURPOSE:To form a sharp image superior in powder characteristics by executing an operation for removing a part of surfactant adhered to produced microcapsules and reducing an amt. of surfactant to a specified percentage or less of the total weight of the capsulated toner. CONSTITUTION:A surfactant used in a step for producing microcapsules in an aq. medium tends to adhere to the produced microcapsules in a considerable amt. The capsulated toner obtained by separating them in an adhered state from the aq. medium and drying them scarcely obtain satisfactory powder characteristics, and their electric resistance and chargeability are readily affected by environmental conditions, such as temp. and humidity. The capsulated toner superior in the powder characteristics, etc. are obtained by lowering an amt. of surfactant to <=1wt%. To produce the capsulated toner small in an amt. of surfactant adhered to them, it is desirable to wash the produced microcapsules once or in several times with a solvent, such as water, and remove them adhered to the surfaces of the outer shells to an extent as small as possible, and then to subject them to a drying treatment, such as spray drying.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing toner used for converting a latent image formed in an electrical or magnetic recording method such as electrophotography or magnetic recording method into a visible image. It is something.

Various electrical or magnetic recording methods are known, such as electrophotography, electrostatic recording, or magnetic recording. What they have in common is that the electrically or magnetically formed latent image is converted into a visible image using toner containing a recording material such as a colorant in the form of a powder or dispersion, and this is then transferred to a transfer paper. The image is transferred and fixed onto a support medium such as the like to form a copy image.

In order to turn a latent image into a visible image using toner, generally a developer consisting of carrier particles and toner, or a developer consisting of carrier particles and toner is used.
A developer consisting only of toner and an electric or magnetic attraction force acting between the latent image attracts the toner to the latent image, forms a toner image on the latent image, and develops the latent image, creating a visible image. The method is used. Here, the former development method using a developer consisting of carrier particles and toner is called a two-component development method, and the latter development method using a developer consisting only of toner is called a one-component development method. There is.

The toner image formed on the latent image is then transferred onto a medium, such as transfer paper, and fused onto the medium. There are three known methods for fixing toner images on media such as transfer paper: heat fixing, solvent fixing, and pressure fixing. This is what we provide.

Pressure fusing methods, in which toner particles are fused onto a medium by applying pressure to the toner particles transferred onto the medium, are described in US Pat. No. 3,289,528. Since this method does not use heat or solvent, it does not suffer from the various problems associated with methods such as heat fixing or solvent fixing, and the access time is fast, making it compatible with high-speed fixing methods. It inherently has various advantages such as points.

However, the pressure fixing method has poor fixing properties compared to fixing methods such as heat fixing, and the fixed image easily peels off when rubbed, and requires considerably high pressure for fixing, so it is difficult to use a support like transfer paper. Fatigue of the media is likely to occur due to damage to the lam of the media, and the surface of the support media tends to become excessively glossy, and the pressure roller used to apply high pressure is small. Because there are limits to
There are various problems, including limitations on miniaturization of the entire copying apparatus.

In order to solve the above-mentioned problems associated with the pressure fixing method, capsule toner in which toner is contained in microcapsules has already been developed. Capsule toner is a toner in the form of microcapsules obtained by forming an outer shell around a core material containing a display recording material such as carbon black, which has the property of being destroyed by the application of pressure. Capsule toner is said to be a toner suitable for the pressure fixing method because it does not require high pressure for fixing and has excellent fixing properties. This cannot necessarily be said to be satisfactory for the various properties that are originally needed.

In other words, toner used as an electrophotographic developer is required to have good powder characteristics, excellent developing performance, and not to stain the surface of the photoreceptor, which is the surface on which the latent image is formed. In the case of a two-component development method, it is necessary that the surface of the carrier particles used is not contaminated. In addition, the toner used in the pressure fixing method has good pressure fixing properties and is unlikely to cause offset phenomenon (a phenomenon in which toner adheres to the pressure roller surface and stains it) on the pressure roller used for pressure fixing. It becomes necessary. In other words, the toner used in the pressure fixing method has powder properties, fixability to support media such as paper (including the shelf life of the fixed image), non-offset properties, and chargeability and chargeability depending on the developing method used. All properties such as conductivity and/or conductivity must be at a high level. However, the capsule toners known so far have not always been satisfactory for the above-mentioned properties.

For example, the general manufacturing method for capsule toner is as follows:
Microcapsules are prepared by forming an outer shell made of a resin material around a hydrophobic core material containing a display and recording material dispersed as microdroplets in an aqueous medium, and then this microcapsule dispersion is subjected to a process such as spray drying. A method is known in which powdery capsule toner is obtained by drying using a drying method. In the manufacturing method of such capsule toner, in order to stably disperse the hydrophobic core material and outer shell material as microdroplets in the aqueous medium, a protective colloid consisting of a hydrophilic polymer compound etc. is added to the aqueous medium. However, when a microcapsule dispersion formed in the presence of such a protective colloid is dried by spray drying or the like, a large number of capsule particles become secondary particles in the resulting capsule toner. There is a tendency to cause agglomeration. Alternatively, even if the capsule toner obtained by drying is in a powder state immediately after drying, it tends to aggregate if it is placed in a high-humidity, high-temperature environment or left in the air at room temperature for a long period of time. In addition, capsule toner often aggregates during the actual developing process in a developing device, and in such cases, problems such as a significant deterioration in the resolution of the developed visible image occur.

In addition, capsule toners manufactured using protective colloids made of wood-philic polymer compounds as described above tend to have high temperature dependence in electrical resistance and chargeability. When an electrophotographic method is carried out using the electrophotographic method, the resulting image is easily affected by environmental conditions such as temperature and humidity, and a problem arises in that it is difficult to obtain a stable image.

On the other hand, it has been considered to use a surfactant instead of a hydrophilic polymer compound to disperse a hydrophobic core substance into microdroplets in an aqueous medium, but capsules manufactured using a surfactant Toners also tend to have a large temperature dependence in electrical resistance and chargeability. Therefore, when electrophotography is performed using such capsule toners, the images obtained may be affected by environmental factors such as temperature and humidity. The problem arises that it is easily affected by conditions and it is difficult to obtain stable images.

Therefore, an object of the present invention is to provide a method for producing a capsule toner having excellent powder characteristics. Furthermore, the present invention provides a method for producing a capsule toner whose electrical resistance and chargeability are not easily affected by environmental conditions such as temperature and humidity, and which enables constant formation of clear images even under normal fluctuations in environmental conditions. This is also included in the purpose of the present invention.

The present invention involves forming microcapsules by forming an outer shell around a core material containing a display recording material dispersed in the form of microdroplets in an aqueous medium containing a surfactant, and then dispersing the microcapsules. In a method for producing a capsule toner that involves separation from an aqueous medium, the surfactant attached to the resulting capsule toner is removed by removing at least a portion of the surfactant attached to the generated microcapsules. The method for producing a capsule toner is characterized in that the amount of the powder is 1% by weight or less based on the total weight of the capsule toner.

In addition, when a hydrophilic polymer compound is used in combination with a surfactant in the above-mentioned microcapsule manufacturing process, at least a portion of the hydrophilic polymer compound attached to the generated microcapsules is also removed. By doing this, the amount of the hydrophilic polymer compound attached to the obtained capsule toner is 5% based on the total weight of the capsule toner.
It is necessary to keep the amount below % by weight in order to obtain a capsule toner with excellent powder characteristics.

That is, according to the research of the present inventors, the surfactant (or both the surfactant and the hydrophilic polymer compound) used in the process of producing microcapsules in an aqueous medium By separating the microcapsules from the aqueous medium with such surfactants (or both the surfactant and the hydrophilic polymer compound) attached and drying them, a considerable amount tends to adhere to the capsules. It has been found that the resulting capsule toner does not exhibit satisfactory powder properties and its electrical resistance and chargeability are sensitive to environmental conditions such as temperature and humidity. The present invention was completed based on this knowledge.

Next, the present invention will be explained in detail.

A method for preparing microcapsules by forming an outer shell around a core material containing a display recording material and a binder that assists in fusing the display recording material to a support medium in an aqueous medium such as water. These methods are already known, and these known methods can also be used in the production method of the capsule toner of the present invention.

For example, methods for producing microcapsules that can be used in the present invention include interfacial polymerization and external polymerization.

Other examples of microcapsule manufacturing methods that can be used in the present invention include an internal polymerization method, a phase separation method, a melting fractionation cooling method, and a coacervation method.

Note that the method for manufacturing microcapsules that can be used in the present invention is not limited to those exemplified above, and other methods for manufacturing microcapsules can also be used. Moreover, these various methods can also be used in combination.

Various materials are already known as materials constituting the outer shell of microcapsules, and any of these known materials can be used in the present invention.

Examples of such materials include proteins such as gelatin and casein; vegetable gums such as gum arabic and sodium alginate; celluloses such as ethylcellulose and caffleboxymethylcellulose; polyamides, polyesters, polyurethanes, polyureas, polysulfonamides, and , sulfanate, carbonate, amino resin,
Condensation polymers such as alkylene resins and silicone resins; Copolymers such as maleic anhydride copolymers, acrylic acid copolymers, and methacrylic acid copolymers; Vinyls such as polyvinyl chloride, polyethylene, and polystyrene. Examples include polymers based on polymers; curable polymers such as epoxy resins; and polymers based on inorganic materials.

Among the methods for producing microcapsules, one of the most preferable yet uninvented methods is the interfacial polymerization method.

Among these, a particularly preferred method is the method described below.

First, substances A and B having the following properties are prepared.

Substance A: A hydrophobic liquid itself, or a substance that has the property of dissolving or dispersing well in a hydrophobic liquid.

Substance B: A substance that is either a hydrophilic liquid itself or has the property of dissolving or dispersing well in a hydrophilic liquid.

Substance A and substance B react with each other to form polyurethane resins, polyamide resins, polyester resins, polysulfonamide resins, polyurea resins, epoxy resins, polysulfanate resins, which are insoluble in both hydrophilic liquids and hydrophobic liquids. Or it is a substance that has a relationship to form either polycarbonate resin.

Next, the A substance and the core substance (display recording material, / Kuider,
If desired, a hydrophobic liquid consisting of a magnetic substance powder, etc.) is emulsified and dispersed into microdroplets in a hydrophilic liquid containing a protective colloid consisting of substance B and a surfactant (or a surfactant and a hydrophilic polymer compound). The hydrophilic liquid and the hydrophobic liquid are reacted at the interface of the hydrophilic liquid and the hydrophobic liquid by a method such as heating and then heating. Insoluble polyurethane resin, polyamide resin, polyester resin, etc.

A dispersion is prepared in which macrocapsules containing a core material are dispersed by forming an outer shell made of any one of a lysulfonamide resin, a polyurea resin, an epoxy resin, a polysulfanate resin, or a polycarbonate resin.

In the present invention, a particularly preferred combination of substance A and substance B is such that a polyurethane resin or polyurea resin is formed by the reaction of both substances.

Examples of substances A suitable for producing such polyurethane resins or polyurea resins include the following compounds containing an incyanato group or an inthiocyanate group.

(1) Diisocyanate m-phenylene diisocyanate, p-7 ethylene diisocyanate, 2,6-tolylene diisocyanate, 2
−． 4-) lylene diisocyanate, naphthalene-1,
4-diisocyanate, diphenylmethane-4,4°-
Diisocyanate, 3,3'-dimethoxy-4,4'-
Biphenyl diisocyanate, 3,3゛-dimethyldiphenylmethane-4,4'-diisocyanate, xylylene-1,4-diisocyanate, xylylene-1゜3-
Diisocyanate, 4,4''-diphenylpropane diisocyanate, trimethylene diisocyanate, hexamethylene diisocyanate, propylene-1,2-diisocyanate, butylene-1,2-diisocyanate,
Ethyridine diisocyanate, cyclohexylene-1,
2-diisocyanate, cyclohexylene-1,4-diisocyanate, tolylene diisocyanate, triphenylmethane diisocyanate.

(2) Triisocyanate 4.4',4''-1 rifhenylmethane triisocyanate, polymethylene polyphenylisocyanate.

(3) Tetraisocyanate 4.4'-dimethyldiphenylmethane-2°2', 5
, 5°-tetraisocyanate.

(4) polyisocyanate prepolymer adduct of hexamethylene diisocyanate and hexanetriol; 2.
4-1 Adduct of lylene diisocyanate and catechol,
Adducts of tolylene diisocyanate and hexanetriol, adducts of tolylene diisocyanate and trimethylolpropane, adducts of xylylene diisocyanate and trimethylolpropane.

(5) Diisothiocyanate tetramethylene dithiocyanate, hexamethylene dithiocyanate, P-phenylene dithiocyanate, xylylene-1,4-diisothiocyanate,
Ethyridine dithiocyanate.

Similarly, examples of the B substance suitable for such a combination include the following compounds.

(1) Water (2) Polyol ethylene glycol, 1,4-bucundiol, catechol, resorcinol/Xhydroquinone, l,2-dihydroxy-4-methylbenzene, 1,3-dihydro,
xy-5-methylbenzene, 3,4-dihydroxy-1
-Methylbenzene, 3゜5-dihydroxy-1-methylbenzene, 2,4-dihydroxy-1-ethylbenzene, 1,3-naphthalenediol, 1,5-naphthalenediol, 2.3-naphthalenediol, 2,7- Naphthalene diol (3) Polyamine ethylene diamine, tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, p-2 enylene diamine, m-phenylene diamine, 2-hydroxytrimethylene diamine, diethylene triamine, triethylene tetraamine, diethylaminopropyl Amine, tetraethylenepentamine, adduct of epoxy compound and amine.

(4) Pivera, ginpiperazine, 2-methylbiperazine, 2,5-dimethylpiperazine.

When using multiple types of substances A or B, polyurethane resins or polyurea resins prepared using substances A and B may contain both urethane bonds and urea bonds in their molecular chains, or may contain both urethane bonds and urea bonds. In some cases, the molecular chain contains both thiourethane bonds,
These resins are also included in the expression polyurethane resin or polyurea resin, similar to those having only urethane bonds or urea bonds.

Furthermore, in the above combination of A substance and B substance, A
An outer shell made of various resin materials such as polyamide resin can also be formed by replacing eI with acid chloride, sulfonyl chloride, or bischloroformate as exemplified below.

oxazoloyl chloride, succinoyl chloride,
Adipoyl chloride, sebacoyl chloride, phthaloyl chloride, isophthaloyl chloride, terephthaloyl chloride, fumaroyl chloride, 1,4-cyclohexane dicarbonyl chloride, polyester with acid chloride functional group, acid chloride functional group Polyamide with.

(2) Sulfonyl chloride 1.3-benzenedisulfonyl chloride, 1.4-benzenedisulfonyl chloride, 1.5-naphthalenedisulfonyl chloride, 2.7-naphthalenedisulfonyl chloride, p,p'-monooxybis(benzene disulfonyl chloride), 1,6-hexanedisulfonyl chloride.

(3) Bischloroformate ethylene bis(chloroformate), tetramethylene bis(chloroform-)), 2,2°-dimethyl-1,3
-Propane bis(chlorformate), p-propane bis(chloroformate).

In addition, a hydrophobic liquid consisting of substance A and a core substance is dispersed into microdroplets in a hydrophilic liquid containing substance B and a protective colloid consisting of a surfactant (or a surfactant and a hydrophilic polymer compound). In this case, it is preferable to mix a low boiling point solvent or a polar solvent with the hydrophobic liquid consisting of the A substance and the core substance. These low boiling point solvents or polar solvents contribute to promoting the formation of an outer shell, which is a reaction product between substance A and substance B. Examples of low-boiling or polar solvents that can be used for such purposes include methyl alcohol, ethyl alcohol, ethyl ether, tetrahydrofuran, dioxane, methyl acetate, ethyl acetate,
Acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, n-pentane, n-hexane,
Benzene, petroleum ether, chloroform, carbon tetrachloride,
Examples include methylene chloride, ethylene chloride, carbon disulfide, and dimethylformamide.

The material for the outer shell is not particularly limited as long as it has the property of breaking under pressure, and in addition to the polymer materials mentioned above, for example, polymers of styrene or substituted products thereof, or co-producers thereof may be used. Polymers (for example, polystyrene, polyparachlorostyrene, styrene/butadiene copolymer, styrene/acrylic acid copolymer, styrene/acrylic hard ester copolymer, styrene/methacrylic acid copolymer, styrene φ methacrylate copolymer) polymers, styrene/maleic anhydride copolymers, styrene/vinyl acetate copolymers, etc.), polyvinyltoluene resins, acrylic ester homopolymers, methacrylic ester homopolymers, xylene resins, methyl vinyl ether-maleic anhydride resins , vinyl butyral resin, polyvinyl alcohol resin, and polyvinylpyrrolidone.

The outer shell of the capsule toner may also be a composite wall formed from a polymeric material on the rim.

Preferred composite walls in the present invention are composite walls made of polyurea resin and/or polyurethane resin, and polyamide resin. Using a composite wall made of polyurethane resin and polyamide resin, for example, using polyisocyanate and skeleton chloride as the above-mentioned substances A and polyamine and polyol as substances B, the pH of the emulsifying medium that will become the reaction liquid is adjusted and then heated. It can be prepared from Kotobanko. Note that if the amount of bonoamine in this reaction system is in excess of the amount required for the reaction with acid chloride, a composite wall consisting of polyurea resin, polyurethane resin, and polyamide resin will be produced. In addition, a composite wall made of polyurea resin and polyamide resin can be produced by using polyisocyanate and acid chlorite as the above-mentioned substance A and polyamine as substance B, adjusting the pH of the emulsifying medium that becomes the reaction liquid, and then heating it. It can be prepared.

Examples of specific compounds of polyisocyanates, acid chlorides, polyamines, and polyols used to produce composite walls made of the above-mentioned polyurea resins and polyurethane resins, and polyamide resins include polyisocyanates, acid chlorides, polyamines, and polyols. , polyamines and polyols, mention may be made of the compounds listed for the formation of the shell of polyurethane or polyurea.

Examples of acid chlorides include adipoyl chloride, sebacoyl chloride, phthaloyl chloride, isophthaloyl chloride,
Terephthaloyl chloride, fumaroyl chloride, 1,4-cyclohexanedicarbonyl chloride, 4,4'-biphenyldicarbonyl chloride, 4,4°-sulfonyldibenzoyl e chloride F', phosgene, polyester containing acid chloride group, acid Mention may be made of polyamides containing chloride groups.

Note that dicarboxylic acid or an acid anhydride thereof may be used instead of the above acid chloride. Examples of dicarboxylic acids include adipic acid, sepatic acid, phthalic acid, terephthalic acid,
Fumaric acid, 1,4-cyclohexanedicarboxylic acid, 4,
Mention may be made of 4°-biphenyldicarboxylic acid.

An example of the acid anhydride is phthalic anhydride.

Another preferred method for the present invention is an external polymerization method.

In the external polymerization method, for example, a core substance is dispersed into microdroplets in an aqueous medium containing a surfactant, and then reactive monomers, prepolymers, oligomers, etc. are dissolved or dispersed in the aqueous medium, and then the pH is adjusted. The polymerization reaction can be carried out by a method such as forming an outer shell around a core material by causing a polymerization reaction by preparing, heating, using a catalyst, etc.

Further, when an external polymerization method is used in the present invention, the following method can be used, for example.

A method of reacting an organic amine, an acid amide, and a water-soluble epoxy compound (disclosed in Japanese Patent Publication No. 38-24420)
; A method using polycondensation reactions of combinations of urea and formalin, melamine and formalin, or phenol and formalin (Japanese Patent Publication No. 38-12380, No. 38-1)
No. 251β No. 46-30282, JP-A No. 47-423
(Disclosed in various publications such as No. 80 and No. 52-66878); Polyacrylic acid, ethylene,
Method of using maleic anhydride copolymer (Japanese Unexamined Patent Application Publication No. 1983-1999)
No. 9079, No. 51-144383, etc.); method of reacting a spiroacecool-based heterocyclic amine with an aldehyde (Japanese Patent Application Laid-open No. 49-99969, No. 50-
(Disclosed in various publications such as No. 8780).

Moreover, the external polymerization method and the interfacial polymerization method can be used in combination, and good results can be obtained.

The core material used in the present invention contains a display recording material for converting a latent image into a visible image. The display recording material is
Usually, a coloring agent that provides a visible image in its state is used, but a substance that indirectly provides a visible image, such as a fluorescent material, can also be used.

As the colorant, dyes, pigments, etc. that have been conventionally used in dry or wet toners can be used.

For example, carbon black can be used as a black toner. Alternatively, grafted carbon black can also be used.

Examples of chromatic colorants include copper phthalocyanine,
Sulfone higher fatty acids or aromatic sulfonic acid amide compounds, blue coloring agents such as derivative dyes, yellow coloring agents such as benzidine derivatives collectively known as diazo yellow, and polytungstophosphoric acid, molybdic acid and xanthine dyes. Examples include rhodamine B lake which is a double salt, carmine 6B which is an azo pigment, and red coloring agents such as quinacridone derivatives.

The binder contained in the core material disperses and holds the display recording material in the core material, and is used when transferring the visible image made of the display recording material formed on the latent image to a support medium such as paper. , which serves to fix the visible image on the support medium.

Examples of binders used for the above purpose include high-boiling solvents, such as those with a boiling point of 180° C. or higher, and polymers.

Examples of high boiling point solvents that can be used as binders in the present invention include the following compounds.

(1) Phthalate esters dibutyl phthalate, dioctyl phthalate, dioctyl phthalate, dioctyl phthalate, dioclupthalate, didecyl phthalate, butylphthalyl butyl glycolate, dibutyl monochlorophthalate-1.

(2) Nistyl phosphates tricresyl phosphate, tricresyl phosphate, tris(impropylphenyl sulfate, tributyl phosphate, trihexyl phosphate, trioctyl phosphate, trinonyl phosphate, tridecyl phosphate, trioleyl) Phosphate, Tris (
butoxyethyl) phosphate, tris(chloroethyl)phosphate, tris(dichloropropyl)phosphate, (3) citric acid esters 0-acetyltriethyl citrate, 0-acetyltributyl citrate, 0-7 cetyltrihexyl citrate, 0 -Acetyltrioctyl citrate, O-acetyltrinonyl citrate, 0-acetyltridecyl citrate, triethyl citrate, tributyl citrate, trihexyl citrate, trioctyl citrate,
Trinonyl citrate, tridecyl citrate.

(4) Benzoic acid esters butyl benzoate, hexyl benzoate, heptyl benzoate, octyl benzoate, nonyl benzoate, decyl benzoate, dotecyl benzoate, tridecyl benzoate, tetradecyl benzoate, hexadecyl benzoate, octadecyl benzoate,
Oleyl benzoate, pentyl O-methylbenzoate, decyl methylbenzoate, octyl 0-chlorobenzoate, lauryl P-chlorobenzoate, propyl 2,4-dichlorobenzoate, octyl 2,4
-dichlorobenzoate, stearyl 2,4-dichlorobenzoate, oleyl 2.

4-dichlorobenzoate, octyl p-methoxybenzoate.

(5) Fatty acid esters hexadecyl myristate, dibutoxyethyl succinate, dioctyl adipate, dioctyl azelate,
Decamethylene-1,10-diol diacetate, triacetin, tributin, benzyl caprate, pentaerythritol tetracapronate, isoturu/kuido dicap 1 route.

(6) Alkylnaphthalenes methylnaphthalene, dimethylnaphthalene, 1) methylnaphthalene, monoisopropylnaphthalene, diisopropylnaphthalene, triisopropylnaphthalene, tetraisopropylnaphthalene, monomethyl, diethylnaphthalene, inoctylnaphthalene.

(7) Alkyldiphenyl ethers 0-methyldiphenyl ether, m-methyldiphenyl ether, p-methyldiphenyl ether.

(8) Amide compounds of higher fatty acids or aromatic sulfonic acids N,N-dimethyllauramide, N,N-diethylcaprylamide, N-butylbenzenesulfonamide.

(9) Trimellitic acid esters trioctyl trimellitate.

(io) Diarylalkanes Diarylmethanes (dimethylphenylphenylmethane, etc.), Diarylethanes (1-phenyl-1-methylphenylethane, 1-dimethylphenyl-1-phenylethane, 1-ethylphenyl-1-phenylethane) Such).

Further, examples of the above-mentioned high-boiling point solvents and other high-boiling point solvents that can be used in the present invention are described, for example, in the following patent publications.

JP 413-23233, JP 49-2i3481: JP 47-1031, JP 50-62832, JP 50-82078, JP 51-26035, JP 51-
No. 28038, No. 51-28037, No. 51-279
No. 21, No. 51-2'7922: U.S. Patent No. 2,32
No. 2,027, No. 2,353,282, No. 2,5
No. 33,514, No. 2,835,579, No. 2,
No. 852.383, No. 3,287,134, No. 3
, No. 554, 755, No. 3. F378, No. 137, No. 3.8? Ei, No. 142, No. 3700.454, No. 3,748,141, No. 3,837.8E
British Patent No. 958,441, British Patent No. 1,222,753
No. 2 West German Open Gazette (OLS) No. 2,538,889.

Particularly preferable high boiling point solvents for use in the present invention are:
These are phthalate esters, phosphate esters, alkylnaphthalenes, and diarylalkane.

Further, as examples of preferable compounds for the polymer used as a binder in the present invention, the following compounds can be mentioned.

Polyolefin, olefin cobolia, styrene resin, styrene-butadiene copolymer, epoxy resin,
Polyester, rubber, polyvinylpyrrolidone, polyamide, coumaron and indene copolymer, methyl vinyl ether/maleic anhydride copolymer, maleic acid-modified phenolic resin, phenol-modified terpene resin, silicone resin, epoxy-modified phenolic resin, natural resin-modified phenol Resin, amine resin, polyurethane, polyurea, homopolymer or copolymer of acrylic acid ester, homopolymer or copolymer of methacrylic acid ester, copolymer oligomer of lylic acid and long-chain alkyl methacrylate, polyvinyl acetate, polyvinyl chloride .

Further, examples of the above-mentioned polymers and other polymers that can be used in the present invention are described, for example, in the following patent publications.

Special Publication No. 48-304f38, No. 411-1588,
No. 54-8104: JP-A No. 48-75032, No. 48-78931, No. 49-17739, No. 51-132838, No. 52
- [No. 531, No. 52-108134, No. 52-1
No. 19937, No. 53-1028, No. 53-3E12
No. 43, No. 53-118049, No. 55-89854
No. 55-11313E! No. 55: U.S. Patent No. 3,893,933.

Particularly preferred polymers for inclusion in the core material used in the present invention are homopolymers or copolymers of acrylic esters, homopolymers or copolymers of methacrylic esters, or styrene-butadiene copolymers.

Note that the binder in the present invention may be a mixture of a high boiling point solvent and a polymer as described above.

The core material of the capsule toner contains the display recording material and the binder as described above, but it can also contain various additive materials as desired. Examples of such additives include mold release agents such as fluorocarbon resin powders, which are effective in preventing offset. On the other hand, the outer shell of the capsule toner of the present invention is made of a resin material, and if desired, this outer shell may also contain a metal-containing dye, a charge control agent such as nigrosine, a fluidizing agent such as hydrophobic silica, or Other optional additives can be added. These additive substances can be incorporated into the outer shell of the capsule toner at any time, such as when the outer shell is formed or after the capsule toner is separated and dried.

Further, the core substance of the capsule toner may contain a white pigment such as calcium carbonate or titanium dioxide as a color toning agent, if desired.

In addition, all the various materials and substances used in the present invention are
Of course, each of them can be used as a mixture of two or more.

The surfactant used in the production method of the present invention is:

When producing microcapsules in an aqueous medium, it is used as an emulsifier to emulsify and disperse a hydrophobic core substance in the form of microdroplets in an aqueous medium. However, the term surfactant also includes a charge control agent used as necessary to control the chargeability of the capsule toner. Further, the above-mentioned emulsifying surfactant can be added to one or both of an aqueous medium (and/or a hydrophilic liquid) and a hydrophobic liquid to be introduced into an aqueous medium for producing microcapsules.

The surfactant used in the present invention is not particularly limited as long as it is a surfactant suitable for dispersing a hydrophobic substance into microdroplets in an aqueous medium.

Examples of such surfactants include surfactants, ponins (steroids), alkylene oxide conductors (e.g., polyethylene glycol, polyethylene glycol/polypropylene glycol condensates, polyethylene glycol alkyl or aryl ethers, polyethylene glycol esters, polyethylene glycol sorbitan esters, polyalkylene glycol alkyl amines or amides, polyethylene oxide adducts of silicones)
, nonionic surfactants such as glycidol derivatives, (e.g., alkenylsuccinic polyglycerides, alkylphenol polyglycerides), fatty acid esters of polyhydric alcohols, alkyl esters of sugars, urethanes of sugars, esters of sugars; , triterpenoid saponins, alkyl carboxylates, alkyl sulfonates, alkylbenzene sulfonic acids, alkylnaphthalene sulfonates, alkyl sulfates, alkyl phosphate esters, N-acyl-N-alkyl taurine sulfosuccinates, Anionic interfaces having acidic groups such as carbo-oxy groups, sulfo groups, phosphoro groups, [9 ester groups, phosphate ester groups, etc. such as sulfoalkyl polyoxyethylene alkylphenyl ethers and polyoxyethylene alkyl phosphate esters] Mention may be made of activators.

In addition to the above-mentioned various surfactants, examples of the surfactant having a charge control effect include fluorosurfactants.

Particularly preferable surfactants for use in the present invention are:
Hydrophobic group having 8 to 30 carbon atoms and -3o3M or -5O
, M [M is an alkali metal atom, an ammonium ion, an amine, etc.].

Regarding this type of anionic surfactant, Ryohei Oda,
“Synthesis and Application of Surfactants” by Taira Teramura (published by Maki Shoten)
, and 1'5urfac by A. W. Perry
eActive AgentsJ (Inters
science Publications Inc.
New York).

4 Specific examples of the above anionic surfactants include the following compounds.

C12H250'S'Og N & C14H290SOaNa Funnel oil Cl2H25CONHCH2CH20SO3NaC12
H25S Os N & C1,4H29S03Na CH2・COOC8H37 C13H27CON H+S Og Na [In the formula, R
represents -CH(CHI)2 In the present invention, examples of emulsifying equipment for dispersing the hydrophobic core substance into microdroplets in an aqueous medium containing a surfactant include a stirring type and a high-pressure jetting device. A known emulsifying device such as a mold, an ultrasonic irradiation type, or a Negoo type is used. Among them, colloid mills, homogenizers, electromagnetic strain ultrasonic generators, etc. give good results.

In the production method of the present invention, when producing microcapsules in an aqueous medium, a wood-philic polymer compound can be used in combination with a surfactant, if desired.

Examples of hydrophilic polymer compounds include ordinary gelatin, gelatin derivatives obtained by reacting gelatin with other reactive substances, gelatin graft polymers in which polymer chains are grafted onto gelatin, albumin, and casein. Proteins; cellulose derivatives such as hydroxyethylcellulose, carboxymethylcellulose, and cellulose sulfate; sugar derivatives such as gum arabic, sodium alginate, and starch derivatives; and polyvinyl alcohol, polyvinyl alcohol partial acetal, poly-N-vinylpyrrolidone, polyacrylic acid, polymethacrylic acid,
Mention may be made of homopolymers and copolymers having hydrophilic groups such as polyacrylamide, polyvinylimidazole, polyvinylpyrazole and the like.

The surfactant (or the surfactant and the hydrophilic polymer compound) added to the outer shell of the capsule toner of the present invention stably emulsifies and disperses the microdroplets of the core material during the microcapsule manufacturing process, as described above. It is introduced into an aqueous medium for this purpose and as a result adheres to the outer shell surface of the resulting microcapsules. That is, the surfactant (or the surfactant and the wood-philic polymer compound) attached to the outer shell surface of the capsule toner forms an emulsified dispersion consisting of microdroplets of the desired stable core substance in an aqueous medium. It is introduced into the reaction system (aqueous medium) with the main purpose of
Usually, it is introduced into the reaction system in a relatively large amount.

However, according to the research of the present inventors, as mentioned above, the surfactant (or surfactant and hydrophilic polymer compound) introduced in large amounts into the reaction system has a negative effect on the microcapsules produced. There is a tendency for a considerable amount to adhere to the surface of the outer shell, and as a result, in the capsule toner obtained by drying the microcapsules, the properties necessary for a toner such as powder properties are reduced. There was found.

According to the research of the present inventor, excellent powder properties can be achieved by controlling the amount of surfactant adhering to the capsule toner to 1% by weight or less (% by weight relative to the total weight of the capsule toner). It has been found that a capsule toner having the following properties can be obtained. Furthermore, when a hydrophilic polymer compound is used in combination with the surfactant, the amount of the hydrophilic polymer compound attached to the capsule toner is 5% by weight or less (
It was found that a capsule toner having excellent powder characteristics etc. can be obtained by using the same standard).

A capsule toner with a small amount of the surfactant (or a surfactant and a hydrophilic polymer compound) attached according to the present invention is produced. In order to do this, microcapsules prepared in a reaction system in the presence of a surfactant (or a surfactant and a wood-philic polymer compound) are washed one or more times with a solvent such as water. It is more preferable to perform an operation consisting of removing as much of the surfactant and the like adhering to the outer shell surface of the microcapsules as possible, and then subjecting the microcapsules to a drying process such as spray drying. Note that as a method for efficiently removing surfactant and the like adhering to microcapsules generated in an aqueous medium, it is preferable to use a centrifugation method.

As described above, after obtaining microcapsules from which at least part of the surfactant (or surfactant and hydrophilic polymer compound) attached to the microcapsules has been removed,
The microcapsules are separated and dried from the liquid phase (aqueous medium). This separation and drying operation is usually carried out by spray drying a dispersion containing microcapsules. Further, as a method for separating and drying the microcapsules from the liquid phase, methods such as freeze drying can also be used.

In the present invention, the microcapsules separated and dried by the method described above may then be subjected to a heat treatment. This heat treatment further improves the powder characteristics of the capsule toner of the present invention. The heat treatment is preferably carried out at a temperature in the range of 50 to 300°C, more preferably 80 to 15°C.
Particular preference is given to heating at a temperature in the range of 0°C. The heating time varies depending on the heating temperature and the type of core material used, but is usually selected from a range of 10 minutes to 48 hours, and more generally from a range of 2 to 24 hours.

There are no particular restrictions on the equipment and instruments used for heat treatment, such as electric furnaces, Matsufuru furnaces, hot plates,
Any thermal drying equipment and appliances can be used, such as electric dryers, fluidized bed dryers, infrared dryers, etc.

Next, examples of the present invention will be shown.・In addition, in the examples “
%" means "% by weight" unless otherwise specified. , [Example 1] 10 g of a mixed solvent consisting of acetone/methylene and lene chloride at a ratio of 1/3 was added to 30 g of carbon black and magnetite (trade name: EPT-1000, manufactured by Toda Kogyo ■)
A primary liquid was obtained by mixing 15 g of the diisopropylnaphthalene with a dispersion prepared by dispersing it in a mortar in a mortar. Then,
A secondary liquid was obtained by adding 4 g of a 3:1 molar adduct of hexamethylene diisocyanate and hexanetriol to the primary liquid. However, these mixed liquids were prepared while controlling the liquid temperature to 25°C or less.

60 m of water at 20°C and funnel oil (surfactant) 1.2
The above-mentioned secondary liquid was gradually poured into the solution obtained by dissolving g, with vigorous stirring, to prepare an oil-in-water emulsion with an oil droplet diameter of 5 to 15 pm. The preparation of this emulsion is
The experiment was carried out while controlling the liquid temperature to 20°C or less by cooling the outside of the container. After the emulsion was formed, stirring was continued, and 100 mQ of water at 40°C was added thereto. Next, the temperature of this emulsion was gradually increased to 90° C. after 30 minutes. The temperature of the emulsion was maintained at this temperature for 20 minutes to complete the encapsulation.

Next, this Micro Cub Honglu dispersion was centrifuged (50
00 rpm) to separate into microcapsules and a surfactant-containing aqueous solution, and the obtained microcapsules were dispersed in water to prepare a 30% by weight dispersion.

Next, the above microcapsule dispersion was spray-dried to obtain a capsule toner. 0.6% by weight of surfactant (based on the total weight of the capsule toner) was attached to the surface of the outer shell of this capsule toner.

The powder characteristics and volume resistivity of the above capsule toner are (
I) 14°C 140% RH1 and (n) 30・C19
The test was conducted under seven different temperature and humidity conditions including 0% RH.

Under the condition (Z), each capsule particle of the capsule toner existed independently and exhibited smooth flow. Further, the volume resistivity was 1014 Ω-cm. Under the condition (II), the capsule particles of the capsule toner similarly existed individually one by one and exhibited smooth flow. And the volume resistivity is 101
It was 3Ω-cm.

The above capsule toner was used as a one-component magnetic capsule toner at 14°C, 40%RH and 30°C, 190%R.
When an electrostatic latent image formed by a normal electrophotographic method under conditions of H was developed by a magnetic brush method, a good visible image was obtained under all conditions.

This visible image is fixed using a pressure fixing roller at 350kg/
When pressure fixing was performed using a pressure of ctn', the fixing properties were good.
A clear copy image with high image density was obtained. In addition, almost no toner adhered to the roller.

[Example 2] 1 g of carbon black was dispersed in 13 cc of tricresyl phosphate using a mortar, and 1 g of Desmodur L (an addition compound of toluylene diisocyanate and hexanetriol from Bayer in a molar ratio of 1:3) was dispersed in 13 cc of tricresyl phosphate using a mortar. ) was dissolved to obtain a primary liquid.

The above primary compound was dissolved in an aqueous solution obtained by dissolving polyoxyethylene nonyl phenyl ether (Neu, Gen EA-"150, a nonionic surfactant manufactured by Daiichi Kogyo Seiyaku ■) Ig in 50 ml of water at 20°C. The liquid was gradually poured while stirring vigorously to prepare an oil-in-water emulsion with an oil droplet diameter of 5 to 154 m. To prepare this emulsion, the temperature of the liquid was adjusted to below 20°C by cooling the outside of the container. After the emulsion was formed, stirring was continued, and 5% by weight of hexamethylene diamine was added at 20°C.
20g of aqueous solution was added. Next, the temperature of the emulsicon was gradually increased to 90° C. after 30 minutes. The temperature of the emulsion was maintained at this temperature for 20 minutes to complete the encapsulation.

Next, this microcapsule dispersion was centrifuged (50
00 rpm) to separate into microcapsules and a surfactant-containing aqueous solution, and the obtained microcapsules were dispersed in water to prepare a 30% by weight dispersion. This dispersion was again centrifuged and then washed once again, consisting of redispersion in water, and the resulting microcapsule dispersion was spray-dried to obtain a capsule toner. 0.6% by weight of surfactant (based on the total weight of the capsule toner) was attached to the surface of the outer shell of this capsule toner.

The powder characteristics and volume resistivity of the above capsule toner are (
I) 14°C, 40% RH1 and (II) 30°C, 90
It was investigated under two types of temperature and humidity conditions: %RH.

Under the condition (I), each capsule particle of the capsule toner existed independently and exhibited smooth flow. Further, the volume resistivity was 1014 Ω-cm. Under the condition (II'), the capsule particles of the capsule toner similarly existed individually one by one and exhibited smooth flow. And the volume resistivity is 1
It was 0.013 Ω-cm.

Using the above capsule toner as a two-component capsule toner, an electrostatic latent image formed by a normal electrophotographic method under conditions of 14° C., 40% RH and 30° C., 90% RH was developed by a magnetic brush method. , under any conditions -
Good visible images were obtained.

This visible image is transferred to 350k using a pressure fixing roller.
When pressure fixing was carried out at a pressure of g/cm', a copy image with good fixing properties, clearness, and high image density was obtained. In addition, almost no toner adhered to the roller.

[Example 3] Polyimbutyl methacrylate (molecular weight 55) 3gQ1
After heating and dissolving in 5g of diisopropylnaphthalene,
15 g of magnetite (trade name: EPT-tooo, manufactured by Toda Kogyo ■) was added to the dispersion in a mortar, and the mixture was mixed and mixed to obtain a primary liquid.

Then, 2 g of a 3:1 molar adduct of hexamethylene diisocyanate and hexanetriol was added to the primary liquid to obtain a secondary liquid. However, the preparation of these mixed liquids is
The experiment was carried out while controlling the liquid temperature to 25°C or less.

Partial sodium salt of polyvinylbenzenesulfonic acid (manufactured by National Starch Co., Ltd., VER3A) was added to 60 ml of water.
The above secondary liquid was vigorously stirred into an aqueous solution containing a surfactant and a hydrophilic polymer compound obtained by dissolving 3 g of TL-54)0) and 0.1 g of sodium dodecylhenzenesulfonate. While gradually pouring the
1. A 5-drop oil-in-water emulsion of M was prepared.

Separately, 4 g of melamine and 8 g of a 37% by weight formaldehyde aqueous solution were added to 55 g of water, heated and stirred at 60°C, and cooled to 20°C when the mixture became transparent. The melamine/formaldehyde transparent aqueous solution thus obtained was added to the oil-in-ice emulsion and mixed, and then
The pH was adjusted to 6.0 with 0% by weight acetic acid solution, and the liquid temperature was adjusted to 6.0% by weight.
The temperature was raised to 5° C. and stirred for 60 minutes to complete encapsulation.

Next, this microcapsule dispersion was centrifuged (50
00 rpm) to separate the microcapsules from an aqueous solution containing a surfactant and a hydrophilic polymer compound,
The obtained microcapsules were dispersed in water to prepare a 30% by weight dispersion. This dispersion was again centrifuged and then washed once again, consisting of redispersion in water, and the resulting microcapsule dispersion was spray-dried to obtain a capsule toner. The outer shell surface of this capsule toner contains 0.02% by weight of surfactant and 0.02% by weight of surfactant.
5% by weight of a hydrophilic polymer compound (all based on the total weight of the capsule toner) was attached.

The powder characteristics and volume resistivity of the above capsule toner are (
I) 14°C, 40% RH1 and (It) 30°C19
The test was conducted under two types of temperature and humidity conditions: 0% RH.

Under the condition (I), each capsule particle of the capsule toner existed independently and exhibited smooth flow. Further, the volume resistivity was 1014 Ω-cm. Under the condition (II), the capsule particles of the capsule toner similarly existed individually one by one and exhibited smooth flow. And the volume resistivity is 101
It was 4Ω-cm.

The above capsule toner was used as a one-component magnetic capsule toner at 14°C, 40%RH and 30°C, 190%R.
When an electrostatic latent image formed by a normal electrophotographic method under conditions of H was developed by a magnetic brush method, a good visible image was obtained under all conditions.

This visible image was transferred to 350 kg using a pressure fixing roller.
When pressure fixing was carried out at a pressure of /crrf, a copied image with good fixing properties, clarity, and high image density was obtained. In addition, almost no toner adhered to the roller.

[-Comparative Example 1] The encapsulation reaction solution containing microcapsules obtained in Example 1 was directly spray-dried to obtain a capsule toner. 2.0% by weight of surfactant (based on the total weight of the capsule toner) was attached to the outer shell surface of this capsule toner.

The powder characteristics and volume resistivity of the above capsule toner are (
I) 14°C 140% RH1 and (n) 30°C 19
The test was conducted under two types of temperature and humidity conditions: 0% RH.

Under the condition (I), the capsule particles of the capsule toner were slightly agglomerated, but exhibited normal flow. Further, the volume resistivity was 10 Ω-cm. Under the conditions of (IF), agglomeration of capsule particles became severe and a significant decrease in fluidity was observed. Also, the volume resistivity is lOΩ-C
It was m.

When the above capsule toner was used as a one-component magnetic capsule toner and an electrostatic latent image formed by ordinary electrophotography at 14°C and 40% RH was developed by a magnetic brush method, a good visible image was obtained. Obtained. However, 30℃,
The visible image obtained by developing the electrostatic latent image formed under the conditions of 90% RH was insufficient in image density and resolution.

Patent applicant Fuji Photo Film Co., Ltd. Agent Patent attorney Yasuo Yanagawa

Claims (1)

[Claims] l. After forming an outer shell around a core substance containing a display and recording material dispersed in a microscopic form in an aqueous medium containing a surfactant to produce microcapsules, the microcapsules are separated from the aqueous medium. In the capsule toner manufacturing method, the amount of surfactant attached to the resulting capsule toner is reduced by performing an operation to remove at least a portion of the surfactant attached to the produced microcapsules. A method for producing a capsule toner, characterized in that the content is 1% by weight or less based on the total weight of the toner. 2. The method for producing a capsule toner according to claim 1, wherein the adhering surfactant is removed by washing the microcapsules with water. 3. The method for producing a capsule toner according to claim 1 or 2, wherein the outer shell formed around the 3° core material is made of polyurethane resin, polyurea resin, or amine resin. Claim 1, characterized in that the outer shell formed around the 4° core material is a composite wall made of two or more resins selected from the group consisting of polyurea resin, polyurethane resin, and polyamide resin. A method for producing a capsule toner according to item 1 or 2. After forming an outer shell around a core material containing a display recording material dispersed in microdroplets in an aqueous medium containing a 5° surfactant and a hydrophilic polymer compound, microcapsules are produced. In a method for producing a capsule toner, which involves separating the microcapsules from an aqueous medium, the method is performed to remove at least a portion of the surfactant and hydrophilic polymer compound adhering to the produced microcapsules. The amount of surfactant and hydrophilic polymer compound attached to the capsule toner is 1% by weight or less and 5% by weight, respectively, based on the total weight of the capsule toner.
A method for producing a capsule toner characterized by the following steps. 6. The method for producing a capsule toner according to claim 5, wherein the surfactant and hydrophilic polymer compound attached at 6° are removed by washing the microcapsules with water. 7. The method for producing turnip and cell toner according to claim 5 or 6, wherein the outer shell formed around the 7° core material is made of polyurethane resin, polyurea resin or amine resin. 8. Claim 5, characterized in that the outer shell formed around the core material is a composite wall made of two or more resins selected from the group consisting of polyurea resin, polyurethane resin, and polyamide resin. 6. The method for producing a capsule toner according to item 6.