JPH01185651A - Toner for developing electrostatic latent image and production thereof - Google Patents

Abstract

PURPOSE:To obtain a toner having good light transmittability, heat resistance and shape stability by laminating a shell layer consisting of a synthetic resin on the surface of core particles consisting of a coloring agent and thermoplastic resin and specifying the compsn. and properties of the core particles and the shape of toner particles. CONSTITUTION:The toner is formed by laminating the shell layer consisting of the charge control agent and synthetic resin on the outside surface of the core particles consisting of the coloring agent and thermoplastic resin. This toner is so formed that the softening point of the thermoplastic resin to be used for the core particles is <=150 deg.C, the number average mol.wt. 1,000-15,000, and the mol.wt. distribution <=3 and that the fluctuation coefft. of the grain size of the toner itself is <15 and the shape coefft. <=150. The toner which has the excellent light transmittability, is capable of forming a sharp chromatic image, has the excellent heat resistance and shape stability and the stable electrostatic charge quantity and has the excellent developability without having fogging and toner splashing is thereby obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a toner for developing electrostatic latent images. Specifically, the present invention provides a method for developing electrostatic latent images in electrophotography, electrostatic recording, and electrostatic printing.
The present invention relates to a toner for developing electrostatic latent images that exhibits sufficient translucency for use in commercial or full-color applications and provides clear projected images or colored images.

(Prior art) Development of electrostatic latent images in electrophotography, electrostatic recording, and electrostatic printing involves electrostatically adsorbing triboelectrically charged toner to an electrostatic latent image formed on a photoreceptor. This is done by visualizing the results.

As a method for charging the toner used in developing such an electrostatic latent image, in a two-component development method, it is known that charging is imparted by mixing and stirring with a material generally called a carrier. It is also known that in the -component development method, charge is imparted by contact with a developing sleeve, a toner regulating blade, a photoreceptor, or the like. In either method, if the toner is not uniformly charged, problems occur during development and transfer.

For example, in the past, toners were generally prepared by mixing and melt-kneading pigments in a thermoplastic resin to form a dispersion.
It is known that toner particles are produced by a so-called pulverization method in which toner particles are obtained by cooling, solidifying, pulverizing and classifying toner particles.

Also known are those obtained by a suspension method in which a polymerizable monomer, a polymerization initiator, a coloring agent, and the like are mixed and dispersed and polymerized in water. However, in all toners obtained by these methods, the colorant blended in the resin is partially exposed on the surface of the toner particles, and in order to prevent this colorant from affecting charging properties, the coloring The chargeability changes depending on the type and amount of the agent, and as a result, the distribution of the charge amount of the toner becomes wider, and this causes problems such as toner scattering and fogging. Furthermore, in the case of toner produced by the pulverization method, the degree of variation in the charge amount distribution of the toner varies depending on whether each composition of the toner is uniformly dispersed. Therefore, it is an important issue to uniformly disperse each toner composition in each toner.

In addition, in recent years, toners for developing electrostatic latent images have been made into composite structures for the purpose of separating functions or improving surface properties in order to respond to higher definition, higher image quality, and diversifying toner functions and uses. Various types of toner have also been proposed.

For example, JP-A-61-275767 discloses a layer consisting of a magnetic material and/or a coloring agent on the surface of the core particle, and a layer of at least one fluorine-containing monomer, an amino group-containing monomer, and a nitro group-containing monomer. A toner obtained by laminating a capsule layer made of a monomer polymer containing tsummer in a wet process was also disclosed in Japanese Patent Publication No. 59-3858.
No. 3 has a toner in which a coating layer made of microparticles formed by emulsion polymerization is wet-formed on the surface of core particles, and JP-A-62-226162 has a toner in which a coating layer made of microparticles formed by emulsion polymerization is wet-formed on the surface of a colored thermoplastic resin. A toner is shown that has been subjected to heat treatment after attaching fine resin particles. In all of these toners, we focused on the fact that the electrical properties of the toner mainly depend on its surface area, and by attaching resin fine particles to the surface of core particles containing colorants, magnetic substances, etc. This is an attempt to achieve stable charging properties through physical properties or surface shape. However, in these toners, the resin layer wet-adhered to the surface of the core particle was
As is clear from the electron micrograph shown in No. 2-226162, it is formed from minute resin particles that are fixed to core particles while maintaining their particle shape.
Therefore, the resin layer does not completely cover the surface of the core particle (ie, it is not dense). Therefore, even in toners with such a configuration, there is a high risk that stable charging properties may not be obtained due to the influence of colorants, magnetic powder, etc. in the core particles, and especially if the toner is stored under severe temperature conditions or When used, the components constituting the core particles leak onto the toner surface through the gaps between the fine resin particles, causing an even greater effect. Incidentally, when the core particle component leaches onto the surface of the toner in this way, a problem arises in that the toner particles also coagulate together.

By the way, in developing the above-mentioned special electric latent image, the visualized image is further exposed to an overhead projector (
When projecting an image using an optical projection device such as an OHP, it is necessary to show chromaticity on the projection surface.
Also, three-color separation exposure and subtractive color method Three primary colors (or four colors including black)
When making a so-called full-color copy in which the colors of the original image are reproduced by combining color toners (colors), it is necessary to reproduce a variety of intermediate colors, and in both cases, it is necessary to form a toner layer with high fixation and immersion transparency.

Therefore, in the electrostatic latent image developing toner used for such applications, in order to form a highly transparent toner layer after fixing, it is necessary to uniformly melt the resin contained in the toner as the fixing resin.

For this reason, it is considered to be extremely effective to reduce the molecular weight of the synthetic resin and narrow the molecular weight distribution to make it a sharp melt with low viscosity.

However, synthetic resins with such characteristics are generally used as fixing resins in toners using the conventional pulverization method or suspension method as described above. This causes problems such as fogging, toner scattering, and contamination on the photoreceptor due to the spread of the charge amount distribution. Furthermore, when obtained by a pulverization method, the resin component is brittle, resulting in an extremely poor yield during production, which also poses a problem in terms of cost. Further, even if it is used as the core particle of a toner having a resin layer made of fine resin particles as described above, since the fine resin particles are each independent and the resin layer does not have shape-retaining properties, it can be easily crushed. It was something that would have been done.

Furthermore, in order to uniformly melt the resin contained in the toner to form a highly transparent toner layer and to obtain higher fixing properties, it is desirable that the softening point of the synthetic resin be lower. Such synthetic resins with a low softening point cannot be said to be good in terms of their heat resistance or environmental resistance. When used in a toner, the toner easily cakes or aggregates during handling or storage, and even if it is used for the core particles of a toner having a resin layer made of fine resin particles as described above, In addition to the high fluidity due to the low molecular weight and low molecular weight distribution, the core particle component easily leaches out to the surface during handling or storage, and even if no cake or aggregation occurs, the leaching as described above will occur. The core component affected the chargeability, making it practically impossible to use it.

(Problem M to be Solved by the Invention) Therefore, it is an object of the present invention to provide a new toner for developing electrostatic latent images which solves the above-mentioned problems. A further object of the present invention is to provide a toner for developing electrostatic latent images that exhibits excellent light transmittance and, at the same time, has excellent fixing properties and heat resistance. Another object of the present invention is to provide a toner for developing electrostatic latent images that has stable chargeability and at the same time has uniform chargeability among particles. The present invention further provides charging properties, development amount, cleaning properties, fluidity, etc. that fully correspond to high definition in terms of line reproducibility, and high image quality in terms of texture, halftone dot reproducibility, gradation, resolution, etc. The purpose of this invention is to provide a toner for developing electrostatic latent images having powder properties such as
There is.

(Means for Solving the Problems) The above objects are composed of a core particle made of at least a colorant and a thermoplastic resin, and an outer shell layer made of at least a synthetic resin and coated on the outer surface of the core particle. In the toner for developing electrostatic latent images, the thermoplastic resin used for the core particles has a softening point of 150° C. or lower, a number average molecular weight Jt of 1000 to 5000, and a molecular weight distribution M w /
Mn is 3 or less, the coefficient of variation of the particle size of the electrostatic developing toner itself is less than 15%, and the shape factor SFI is 1.
This is achieved by a toner for developing an electrostatic latent image, which is characterized by having a particle diameter of 50 or less.

The above objects also include at least a colorant and a softening point of 15
A step of electrostatically adhering fine particles made of synthetic resin to the surface of a core particle made of thermoplastic resin having a number average molecular weight of 1000 to 15000 and a molecular weight distribution Mw/Mn of 3 or less at 0°C or less, and A method for developing electrostatic latent images characterized by comprising a step of forming an outer shell layer by melting the surface by mechanical shearing force, and a step of melting and fixing a charge control agent on the outer shell waste. This is achieved by a toner manufacturing method.

Hereinafter, the present invention will be explained in more detail based on embodiments.

The electrostatic latent image developing toner of the present invention mainly contains thermoplastic resin,
It has a 72-layer structure using resin particles as a core material.

However, in the toner for developing electrostatic latent images of the present invention, the softening point of the thermoplastic resin used for the core material is 150°C or lower, more preferably 130°C or lower, and the number average molecular weight is 1too.
o~15000, more preferably 2000~9000,
The first characteristic is that the molecular weight distribution Mw/Mn is 3 or less, more preferably 2.5 or less.

As described above, in the toner for developing electrostatic latent images of the present invention,
By reducing the molecular weight of the thermoplastic resin that constitutes the core particles that function as the fixing resin, and by narrowly limiting the molecular weight distribution, the viscosity of the thermoplastic resin is 1-1 and that of a low-viscosity sharp-melt resin, and the softening point is lower, resulting in better melting properties. This provides uniform melting of the thermoplastic 1M matrix during fixing, and forms a highly transparent toner layer exhibiting sufficient light transmittance after fixing. The molecular weight, molecular weight distribution, and softening point ranges described above were found as a result of intensive research by the present inventors as characteristics necessary to exhibit sufficient translucency for OHP or full color applications. However, as will be shown in the later-described embodiments compared to those outside this range, there is a very significant difference in light transmittance. The thermoplastic resin constituting the core particles is not particularly limited in other physical properties as long as the molecular weight, molecular weight distribution, and softening point are within the above ranges, but the melt viscosity ηtoot is 1.
If it is 04 to 106 poise, better translucency can be obtained.

Types of thermoplastic resins with such physical properties include:
It is not particularly limited as long as it is commonly used as a binder in normal toners, but as mentioned above, the following are examples of highly fluid materials with low molecular weight and extremely narrow molecule distribution. Preferable examples include homopolymers or copolymers made of various vinyl monomers as shown below. That is, examples of vinyl monomers include styrene,
O-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p -n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3.4 Examples include styrene and its derivatives such as -dichlorostyrene, among which styrene is most preferred. Examples of other vinyl monomers include ethylene, propylene, butylene, imbutylene, ethylenically unsaturated monoolefins, vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride and other vinyl halides, and vinyl acetate. , vinyl propionate,
Vinyl esters such as vinyl penzoate and vinyl butyrate, methyl acrylate, ethyl acrylate, acrylic acid n
-Butyl, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, α-
Methyl chloroacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n methacrylate
-methylene such as butyl, isobutyl methacrylate, propyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, etc. Aliphatic monocarboxylic acid esters, (meth)acrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether, vinyl methyl ketone,
Examples include vinyl ketones such as vinylhexyl ketone and methyl isopropenyl ketone, N-vinyl compounds such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, and N-vinylpyrrolidone, and vinylnaphthalenes.

Further, in the toner for developing electrostatic latent images of the present invention, the resin particles mainly composed of the above-described thermoplastic resin used as the core particles may be obtained by pulverization, emulsion polymerization, emulsion polymerization,
Any toner particle manufacturing method may be used as long as it can be obtained by a known method for manufacturing toner particles, such as by a granulation polymerization method such as suspension polymerization, or by a wet granulation method such as @ turbidity method or spray drying method. Since the shape and particle size distribution of the resin particles greatly influence the shape and particle size distribution of the final toner particles, and affect the fluidity and charge amount of the toner particles, it is desirable that the resin particles as the core particles have a high sphericity. It is preferable that the particles have a high particle size distribution and a narrow particle size distribution, and those obtained by a granulation polymerization method such as emulsion polymerization or suspension polymerization are preferable.

In particular, among these granulation polymerization methods, when granulation is performed using a method known as seed polymerization, particles with high sphericity and narrow particle size distribution can be easily obtained, and the degree of polymerization can also be easily controlled. Therefore, it becomes an extremely desirable resin particle. This seed polymerization is, as shown in Japanese Patent Publication No. 57-24369, etc., in which a part of a polymerizable monomer and a polymerization initiator are added to an aqueous medium or an aqueous medium to which an fL agent has been added and stirred. After emulsification, the remainder of the polymerizable monomer is gradually added dropwise to obtain fine particles, and using these particles as seeds, polymerization is carried out in the polymerizable monomer droplets.

Therefore, the resin particles used as the core material have a particle size variation coefficient of less than 10%, more preferably less than 8%. In addition, the resin particles used as the core material to form the i7F layer structure and obtain high sphericity as the final toner particles are naturally spherical.
That is, the shape factor SFI is 120 or less, preferably 11
5 or less is used.

Note that it is possible to incorporate a colorant into the resin particles obtained in this way, or to form a colorant layer on the surface of the resin particles obtained without incorporating a colorant. Therefore, in the above-mentioned granulation polymerization method, it is possible to dissolve or disperse the colorant in the polymerizable monomer and granulate the resin particles containing the colorant, but it is also possible to granulate resin particles containing the colorant. It is desirable not to add a coloring agent in order to obtain the desired result.

Any polymerization initiator, particularly an oil-soluble polymerization initiator, can be used in the case of polymerizing the above-mentioned polymerizable monomers to obtain desired resin particles at a normal temperature range. Specific examples of polymerization initiators include 2,2-
-azobisisobutyronitrile, 2,2゛-azobis-
Azo compounds such as 2,4-dimethylvaleronitrile, 2,2-1azobis-4-methoxy-2,4-dimethylvaleronitrile, acetylcyclohexylsulfonyl peroxide, diisopropyl peroxydicarbonate, decanonyl peroxide, lauroyl peroxide, stearoyl peroxide, acetyl peroxide, t-butylperoxy-2-ethylhexanoate, benzoyl peroxide, t-bunalperoxyisobunal-1, cyclohexanone peroxide,
Examples include peroxides such as methyl ethyl ketone peroxide, dicumyl peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, and cumene hydroperoxide. The amount of these polymerization initiators used is 0.01 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the monomer. That is, if it is less than 0.01 part by weight, the polymerization rate will be slow, while if it is more than 10 parts by weight, it will be difficult to control the polymerization.

In the electrostatic latent image developing toner of the present invention, a coloring agent layer is formed on the surface of the resin particles as described above, if necessary.

The method of forming a coloring agent layer containing a coloring agent on the surface of the resin particles is not particularly limited. After being attached by van der Waals force and electrostatic force, the colorant may be attached and fixed to the base particles by heat or mechanical impact force, or the colorant may be attached and fixed together with the thermoplastic resin fine particles. It is also possible to adhere and fix synthetic resin fine particles containing , or to use a dye as a coloring agent.

As the colorant used in the electrostatic latent image developing toner of the present invention, various pigments and dyes of various colors as shown below can be used.

Examples of yellow pigments include C,1,10316 (Naphthorue O-3), C,I,l 1710 (A7 The Yellow 10G), C,1,11660 (Hansa Yellow 5G>
,C,1,11670 (Hansaero-3G),C,1,
11680 (Hansa Yellow G), C, 1, 11730 (
Ha7za x Low GR), C.

1.11735 (Hansa Yellow A), C, 1,117
40 (A7 xo-RN), C, 1, 12710 (Hansa Yellow R), C, 1, 12720 (Pigment Yellow L), C, 1, 21090 (Benzidine Yellow), C,
L 121095 (Benzidine Yellow G>, C, 1,
21100 (Benzidine Yellow GR), C, 1,200
40 (Permanent Yellow NCG), C, 1, 2122
0 (Parkan Fast Yellow 5>, C, 1, 21135
(Parkan Fast Yellow R etc.)

Red pigments include C, 1, 12055 (Stalin I>, C, 1, 12075 (Permaphone 1 to orange)
, C, 1, 12175 (Resol Fast Orange 3G
L), C, 1, 12305 (Permanent Orange GT
R), C, 1, 11725 (Hansa Yellow 3R), C
,1,21165 (Palcan Fast Orange GG),
C.I.

21110 (Benzidine Orange G), C,I.

12120 (Permanent Red 4R), C, I.

1270 (Para Red), C, 1, 12085 (Fire Red>, c, 1.12315 (Brilliant Fast Scarlet), C, 1, 12310 <Permanent Red F2R), C, I.

12335 (Permanent Red F4R), C.

1.12440 (Permanent Red FRL), C,
1,12460 (Permanent Red FRLL), C,
1,12420 (permanent red F4RH), C,
1,12450 (Light Fas ■ ~ Red Toner B>
, C, 1, 12490 (Bermanen T. Karmin FB)
, C,1,15850 (brilliant carmine 6B> etc.).Also, as a blue pigment, C,1,7410
0 (metal-free phthalocyanine blue), C, 1,7416
0 (phthalocyanine blue LC), 1,74180 (first sky blue), etc.

These colorants can be used alone or in combination, but the synthetic resin 10 contained in the toner particles
0 parts by weight, 1 to 20 parts by weight, more preferably 1
It is desirable to use ~10 parts by weight. That is, 20
If the amount is more than 1 part by weight, the fixing properties of the toner will deteriorate, while if it is less than 1 part by weight, the desired image density may not be obtained.

The toner for developing electrostatic latent images of the present invention has a laminated structure, and its internal structure includes a core material made of resin particles containing a colorant, or a core material made of resin particles, as described above. It can take various forms, such as a coloring agent layer formed on its surface, but in all forms, the outermost surface is coated with such an internal structure as an outer shell layer. A synthetic resin coating layer is formed, and this is the second feature.

As described above, in the toner for developing electrostatic latent images of the present invention, the thermoplastic resin contained in the resin particles constituting the core material has a low molecular weight in order to form a toner layer with high transparency after fixing. It is said to have an extremely narrow molecular weight distribution and a low softening point, making it brittle and having low heat resistance. , storage or storage (even if the core material melts due to the heat applied during receiving, there is no risk of the core material component leaching out to the surface of the toner particles, and there is no risk of toner agglomeration due to the molten resin or chargeability due to the core material component leaching out). , there is no effect on photoreceptor contamination.Furthermore, even if a shearing force that would destroy the core material alone occurs during stirring to impart chargeability, it will not break because it is covered with a synthetic resin coating layer. There is no possibility that the particle size will change due to such factors, and stable charging properties, developability, and resistance to photoreceptor staining are exhibited.

Furthermore, by forming a synthetic resin coating layer that covers the internal structure in this way, the synthetic resin coating layer that is the outer shell layer is almost unaffected by the coloring agent layer or the structure of the core material that exists inside. Depending on the composition of the charge polarity, chargeability,
This is because it is possible to determine the developability, heat resistance, etc., and it is possible to impart stable and uniform chargeability between each toner particle even if the type, amount, etc. of the colorant contained in the core particles changes. be.

In this way, the method of forming a synthetic resin coating layer that covers the internal structure is to use a core material or a core material on which a coloring agent layer has been formed, and a particle size smaller than that of the core material. Approximately 1
Mechanically mixing 15 or less microparticles (i.e., synthetic resin microparticles, synthetic resin microparticles and charge control agent microparticles, or synthetic resin microparticles containing a charge control agent) at an appropriate blending ratio, After the microparticles are uniformly attached around the core material or the core material formed with the colorant layer by the action of van der Waals force and electrostatic force, the microparticles are exposed to a local temperature increase caused by, for example, an impact force. Preferred examples include a method of softening microparticles to form a film. The fine resin particles for forming the outer shell layer used here have an average particle diameter of 0.05 to 3 μm, preferably 0.1 μm.
~1 μm and a particle size distribution coefficient of variation of 20% or less, preferably 15% or less. Powders with an average particle size smaller than 0.05 μm are difficult to manufacture;
7', if it is larger than -3 μm, or the coefficient of variation is 2
When it is larger than 0%, it becomes difficult to coat the surface of the core particle with a film. According to such a method, the shape and particle size distribution of the core material made of the resin particles as described above are not substantially changed, and the synthetic resin is made stronger than the thermoplastic resin contained in the resin particles serving as the core material. Even if the synthetic resin contained in the coating layer has a higher softening point, it can easily form an outer shell layer that substantially completely covers the outer surface of the core particle. The surface properties of the toner particles thus obtained can be determined by selecting the composition and physical properties (particle size, thermal properties, gelling components, etc.) of the core particles and outer shell layer forming particles.
Furthermore, the smoothness and surface roughness can be changed by appropriately selecting the processing conditions and the number of processing times. From the viewpoint of properties such as fluidity, cleanability, and chargeability of the toner particles, it is desirable that the toner particles be spherical and have minute irregularities on the surface.

Apparatuses that can be suitably used in such a method include a hybridization system that applies high-speed air impact method (manufactured by Nara Kikai Seisakusho), Ong Mill (manufactured by Honkawa Micron), and Mechanomill (manufactured by Okada Seiko). )and so on.

However, the method for forming the synthetic resin coating layer is not limited to the above methods.

The synthetic resin contained in this synthetic resin coating layer may be any synthetic resin, such as styrene resins, (meth)acrylic resins, and olefins obtained by polymerizing monomers such as those shown below. thermoplastic resins such as polyester resins, amide resins, carbonate resins, polyethers, polysulfones, etc., or thermoplastic resins such as epoxy resins, urea resins, urethane resins, and their copolymers and polymers Blends etc. can be used. The "synthetic resin" contained in the synthetic resin coating layer refers to anything that is in a complete polymer state, such as thermoplastic resins, or oligomers or prepolymers in the form of thermosetting resins. It also includes polymers containing partially blended polymers, crosslinking agents, etc.

Specifically, monomers constituting such synthetic resins include the following. Examples of vinyl monomers include the above-mentioned styrene monomers,
Ethylenically unsaturated monoolefin monomers, vinyl halide monomers, vinyl ester monomers, α-methylene aliphatic monocarboxylic acid ester monomers, (meth)acrylic acid derivative monomers, vinyl ether monomers, vinyl ketone monomers, N- Examples include vinyl compound monomers and vinylnaphthalene monomers.Also, as monomers for obtaining polyester resins,
Examples of tribasic acids include terephthalic acid, isophthalic acid, adipic acid, maleic acid, succinic acid, cepatic acid, thioglycolic acid, and diglycolic acid. Examples of glycols include ethylene glycol, diethylene glycol, 1. Examples include 4-bis(2-hydroxyethyl)pentene, 1,4-cyclohexane dimetatool, propylene glycol, and the like.

Monomers for obtaining amide resins include caprolactam; tribasic acids include terephthalic acid, isophthalic acid, adipic acid, maleic acid, succinic acid, cepatic acid, and thioglycolic acid; diamines include , ethylenediamine, diaminoethyl ether, 1,4-diaminobenzene, 1,4-diaminobutane, and the like.

As monomers for obtaining the urethane resin, examples of diisocyanates include p-phenylene diisocyanate, p-xylene diisocyanate, and 1,4-tetramethylene diisocyanate, and examples of glycols include ethylene glycol, diethylene glycol,
Examples include propylene glycol and polyethylene glycol.

As monomers for obtaining urea resin, diisocyanates include p-phenylene diisocyanate, p-xylene diisocyanate, 1,4-tetramethylene diinocyanate, etc., and diamines include ethylenediamine, diaminoethyl ether, 1. 4
-diaminobenzene, 1.4-diaminobutane, and the like.

Further, as monomers for obtaining epoxy resin, examples of amines include ethylamine, butylamine, ethylenediamine, 1,4-diaminobenzene, 1゜4-diaminobutane, monoethanolamine, etc., and examples of jepoxies include jig blade. Examples include cidyl ether, ethylene glycol diglycidyl ether, bisphenol A diglycidyl ether, and hydroquinone diglycidyl ether.

As the synthetic resin forming the synthetic resin coating layer, it is possible to use a synthetic resin obtained by polymerizing the above-mentioned monomers alone or in combination, or a nitrogen-containing polar functional resin as shown below. A polymer of a monomer component having a group or fluorine, a copolymer of the above-mentioned monomer with a monomer component having a nitrogen-containing polar functional group or fluorine as shown below, or a polymerization of the above-mentioned monomers. A polymer blend of a polymer having a nitrogen-containing polar functional group or a monomer component having fluorine as shown below may be used. When a synthetic resin with polar groups introduced in this way is used in the synthetic resin coating layer, a charge control agent such as the one described below must be added to the outer shell layer in order for the synthetic resin itself to function as a charge control agent. Even without it, it is possible to impart a certain degree of chargeability.

Nitrogen-containing polar functional groups are effective for positive charge control, and monomers having anionic polar functional groups include the following general formula (I) COCH2=CR2 1/C0X-Q-N (di) \ (in the formula , R1 is hydrogen or a methyl group, R2 and R3 are hydrogen or an alkyl group having 1 to 20 carbon atoms, X is an oxygen atom or a nitrogen atom, and Q is an alkylene group or an arylene group. There are monomers.

Representative examples of amine (meth)acrylic monomers include:
N,N-dimethylamine methyl (meth)acrylate,
N,N-diethylaminomethyl (meth)acrylate,
N,N-dimethylaminoethyl (meth)acrylate,
N,N-diethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, N.

N-dimethylamine butyl (meth)acrylate, p-
N, N-dimethylaminophenyl (meth)acrylate, pN, N-diethylaminophenyl (meth)acrylate-1-, p-N, N-dipropylaminophenyl (meth)acrylate, p-N.

N-dibutylaminophenyl (meth)acrylate, p
-N-laurylaminophenyl (meth)acrylate,
p-N-stearylaminophenyl (meth)acrylate, p-N,N-dimethylaminobenzyl (meth)acrylate, p-N,N-diethylaminobenzyl (meth)acrylate-1~, p-N,N-di Examples include propylaminobenzyl (meth)acrylate, p-N,N-dibutylaminopencyl (meth)acrylate, p-N-laurylaminobenzyl (meth)acrylate, p-N-stearylaminopencyl (meth)acrylate, etc. Ru. Furthermore, N,N-dimethylaminoethyl (meth)acrylamide, N,N-diethylaminoethyl (meth)acrylamide, N.

N-dimethylaminopropyl (meth)acrylamide,
N,N-diethylaminepropyl (meth)acrylamide, p-N,N-dimethylaminophenyl (meth)acrylamide, ρ-N,N-diethylaminophenyl (meth)acrylamide, p-N,N-dipropylaminophenyl (meth) ) acrylamide, p-N, N-dibutylaminophenyl (meth)acrylamide, p-N-laurylaminophenyl (meth)acrylamide, ρ-N-
Stearylaminophenyl (meth)acrylamide, p
-N,N-dimethylaminobenzyl (meth)acrylamide, p-N,N-diethylaminobenzyl (meth)acrylamide, p-N.

N-dipropylaminobenzyl (meth)acrylamide, p-N, N-dibutylaminobenzyl (meth)acrylamide, p-N-laurylaminobenzyl (meth)acrylamide, I) -N-stearylaminobenzyl (
Examples include meth)acrylamide and the like.

Fluorine atoms are effective for negative charge control, and there are no particular restrictions on the fluorine-containing monomer, but for example, 2°2.2-1-
Lifluoroethyl acrylate, 2゜2.3.3-tetrafluoropropyl acrylate, 2.2,3.3.4
, 4.5.5-octafluoroamyl acrylate, I
H, LH, 2H.

Preferred examples include fluoroalkyl (meth)acrylates such as 2H-heptadecafluorodecyl acrylate. In addition, trifluorochloroethylene, vinylidene fluoride, trifluoroethylene, tetrafluoroethylene, trifluoropropylene, hexafluoropropene, hexafluoropropylene, and the like can be used.

Note that the physical properties of the synthetic resin forming the synthetic resin coating layer are not limited to certain values, and preferably, in order to achieve higher heat resistance of the toner particles, the glass transition temperature is 50 to 200°C or higher. It is desirable that the temperature is preferably 55 to 70°C.

Further, the amount of the synthetic resin forming the synthetic resin coating layer is 5 to 50 parts by weight per 100 parts by weight of the internal structure such as the core material containing the colorant or the core material forming the colorant layer. Preferably it is 10 to 30 parts by weight. In other words, if the amount of the synthetic resin forming the synthetic resin coating layer is less than 5 parts by weight, it will be difficult to completely cover the internal structural wood with the synthetic resin coating layer, and the synthetic resin forming the core material will leach out and cause the toner to be damaged. If the amount exceeds 50 parts by weight, uniform synthesis may occur. Unable to form a thin coating layer,
This is because there is a possibility that the particle size distribution of the toner may be expanded or the particle shape may be changed, leading to deterioration of charging characteristics, current (loading characteristics, etc.).

In the toner for developing electrostatic latent images of the present invention, a charge control agent may be added to the synthetic resin coating layer formed to cover such an internal structure.

In this case, since the charge control agent can be localized in the outer shell layer, which is the extratympanic surface of the toner particles, more effective charge control can be performed with a very small amount of charge control agent, and colored charge control can be achieved. Even when a coloring agent is used, the color image is clear and there is no color turbidity, and, for example, even when the particle size is smaller as image quality becomes higher, sufficient chargeability can be imparted. In addition, when a charge control agent is used to impart a monostatic property, the charge level rises and falls rapidly, so a stable charge distribution can be obtained without being affected by differences in stirring time. This is advantageous in improving image quality.

Note that the charge control agent can be present mixed with the synthetic resin constituting the outer shell layer, present on the surface of the outer shell layer, or present in both; It is preferable to localize it only on the surface of the layer. . In the embodiment in which the charge control agent is attached to the surface of the outer shell layer, the charge control agent may be attached to the surface of the outer shell layer formed as described above by the method described above, and then fixed by mechanical impact force or the like. good. However, it is of course not limited to this method.

The charge control agent contained in the synthetic IM fat coating layer is not limited to the conventional ones, and various organic or inorganic agents can be used as long as they can impart LE or negative charge through triboelectric charging.

As a positive charge control agent, for example, nigrosine base EX
(manufactured by Orient Chemical Industry Co., Ltd.), quaternary ammonium ta
p-51 (manufactured by Orient Chemical Co., Ltd.), Nigrosin Pontron N-01 (manufactured by Orient Chemical Co., Ltd.)
, Soutan Chief Schwarz DB (Solvent Black 3: Cofor Index 26150), Fettschwarz HBN (C01, N0126150)
, Brillian 1~Spiritschwarz TN (manufactured by Farchen Fabriken Bayer), Zabonschwarz X
(manufactured by Farberke Hoechst), alkoxylated amines, alkylamides, molybtenic acid chelate pigments, etc., and negative charge control agents include, for example,
Oil black (Color Index26150
), Oil Black BY (Orient Chemical Industry Co., Ltd.), Bontron 3-22 (Orient I / Chemical Industry Co., Ltd.), Salicylic Acid Metal Complex E-81, (Orient Chemical Industry Co., Ltd.), Thioindigo pigment, Copper Sulfonylamine derivatives of phthalocyanine, Spiron Black TRH (manufactured by Hodogaya Kagaku T-gyo Co., Ltd.), Bontron 5-34 (manufactured by Orien Kagaku Kogyo II), Nigrosine SO (manufactured by Orient Kagaku Kogyo Co., Ltd.), Ceres Schwarz (manufactured by Orient Kagaku Kogyo Co., Ltd.) R) G (manufactured by Fareben Fabriken Bayer), Kromogenschwarz E, TOO (C, I, NO, 14645>,
Examples include Azoo and Ilblack (R) (manufactured by National Aniline).

These charge control agents can be used singly or in combination, but the amount of the charge control agent added to the synthetic resin coating layer is based on 100 parts by weight of the synthetic resin forming the synthetic resin coating layer. The amount is 0.001 to 10 parts by weight, preferably 0.001 to 5 parts by weight. In other words, if the amount added is less than 0.001 parts by weight, the amount of charge control agent present on the surface of the toner particles is small, resulting in insufficient charge of the toner, while if it exceeds 10 parts by weight, This is because there is a risk that the charge control agent may peel off from the synthetic resin coating layer and become spent on the surface of the carrier or be mixed into the developer, deteriorating printing durability.

However, in the toner for developing electrostatic latent images of the present invention, it is not necessarily necessary to add such a charge control agent or the above-mentioned polar group-containing resin. In the case of a two-component type regulating blade, if a carrier having a sufficient charge difference with the toner is used, the toner can be charged to a desired charge.

The toner for electrostatic sliding development of the present invention has a stacked M structure as described above, exhibits stable charging properties, fixing properties, heat resistance, etc., and has a toner layer with excellent transparency. More preferably, the shape characteristics of the finally obtained toner particles are such that the coefficient of variation in particle size is 15.
% and the shape factor SFI is preferably 150 or less. In other words, when the 1-toner particles are made to have extremely high sphericity and a narrow particle size distribution, even if the toner particles are made to have a small particle size, it is difficult to maintain high fluidity and stable and uniform charging characteristics. It is capable of imparting stable developability without causing problems such as fog and toner scattering.

Note that the coefficient of variation of particle size used in this specification is
It represents a measure (%) of particle size variation, and is calculated by dividing the standard deviation (σ) in particle size by the average particle size, and is determined as follows. That is, first, a photograph is taken with a scanning electron microscope, and one
00 particles are selected and their particle diameters are measured. Based on this measurement result, the target f! Determine the gap (σ) and average grain size.

The standard 4A difference (σ) used in the present invention is the value obtained by dividing the square of the difference from the average value of each measured value by (n-1>) when n particle diameters are measured. expressed as the square root of

That is, it is expressed by the following equation.

However, Xl, x2...X are the measured values of the particle diameter of the sample particles, xG,! This is the average value of n measured values.

The standard deviation (σ) obtained in this way is calculated as the average particle diameter (
The coefficient of variation was the value obtained by dividing by (ma) and multiplying by 100.

In addition, the shape factor SF1 used in this specification is
It is used as a parameter indicating the difference (distortion property) between the major axis and minor axis of particles, and generally indicates the sphericity of powder particles, and is defined by the formula shown below. Note that each value shown in this specification was measured by an image analyzer (Luzex 5000, manufactured by Nippon Regulator Co., Ltd.).

(In the formula, area indicates the average value of the projected area of the powder, and maximum length indicates the average value of the maximum length in the projected image of the powder.) Therefore, the shape of one henna particle is close to a perfect sphere. The value of the shape factor SFI approaches 100 as the shape increases.

(Example) Hereinafter, the present invention will be explained in more detail with reference to Examples.

Production example of Sunalene-acrylic resin small particles 1.3 with stirrer, condenser, inert gas introduction tube, and thermometer installed.
70 parts by weight of styrene monomer and 25 parts by weight of n-butyl methacrylate were added as a dispersion in a four-hole flask of Ω.
1.5 parts by weight of benzoyl peroxide as a polymerization initiator is used in 1.5 parts of n-butyl acrylate, and 1.5 parts by weight of benzoyl peroxide is used as a dispersion medium. 1000 > 2% and 1% sodium dodecylbenzenesulfonate were mixed in a liquid tank, and a turbine was heated using an R TK autohomomixer j manufactured by Tokushu Kika Kogyo Co., Ltd. as a mixing and dispersing means. The rotational speed was gradually increased from 150Orpm, and mixing and dispersion was carried out at 1200 Oram.While stirring this dispersion mixture at the final rotational speed, 8 (')
Polymerization was carried out by heating for 4 hours at 'C.

After polymerization, it was filtered with a centrifugal dehydrator and washed 8 times with pure water.
Vacuum drying and crushing, number average molecular g; Vl n 700
0, molecular weight distribution Mw7'Mn=2.3, glass transition point 6
5℃ 1 Softening point 120℃ Variation coefficient 13%, Shape coefficient 93FL
=109 styrene-acrylic resin microparticles with a particle size of 0.5 μm were obtained.

Styrene-acrylic tJljf7μ grains -1 J2
In Production Example 1 of Styrene-Acrylic Resin Fine Particles, the raw materials used were 50 parts of styrene monomer, 30 parts of n-butyl methacrylate, and 20 parts of ethyl acrylate.
Styrene-acrylic resin microparticles were obtained in the same manner except that the overlapping part and the polymerization initiator benzoyl peroxide were used in the same manner. The obtained microparticles have a number average molecular weight of Mn70
00, molecular weight distribution Mw/Mn=2.6, glass transition point 4
5℃1 Softening point 95℃ Variation coefficient 12%, Shape factor 5Fl=
110 with a particle size of 0.3 μm.

Styrene-acrylic resin (small particles) Sunalene-acrylic resin microparticles were obtained using the same composition and method as in Production Example 1 of styrene-acrylic resin microparticles, except that the following materials were added as raw materials. The obtained microparticles had a number average molecular weight of JiMn7500 and a molecular weight distribution of M
w/Mn=2.

5. Glass transition point 64℃ 5 Softening point 122℃ 1 Coefficient of variation 1
4%, shape factor 5F1=113, and particle size 0°8 μm.

2.2.2-Trifluoroethyl acrylate
15 fflt portion 2.2-azobis-(2,
4-dimethylvaleronitrile) 0.5 weight! Monodisperse spherical styrene-n obtained by seed polymerization method
-Butyl methacrylate copolymer (average particle size;
7 μm, coefficient of variation: 8%, shape factor 5Fl=108, glass transition temperature: 50°C 1 softening point -128°C, Mn:
6000, Mw/Mn: 2.5>] 1oo heavy part and phthalocyanine pigment (CI74160) triple foot part 109
The mixture was placed in a Henschel mixer and mixed and stirred for 2 minutes at a rotational speed of 1500 ppm to adhere the pigment to the surface of the polymer particles.

Next, Nara Machinery Hybridization System NHS
-1 type, treatment was performed at 900 Orpm for 3 minutes to immobilize the pigment on the surface of the polymer particles.

First, 100 parts by weight of the pigment-treated polymer particles and 10 parts by weight of the fine particles obtained in Production Example 1 of the styrene-acrylic resin particles were treated in the same manner as above to provide a resin coating layer. Furthermore, 100 polymer particles obtained here
Negative charge control agent chromium complex salt type dye E-
By subjecting 0.5 parts by weight of E-81 (manufactured by Orient Chemical Industry Co., Ltd.) to the same treatment as above, E-81 was fixed to the toner surface, and the average particle size of the toner of Example 1 was 8.4.
Toner a with a coefficient of variation of 8% and a shape factor of 5Fl=131 was obtained.

The toner of Example 2 was prepared by using the composition and manufacturing method of the previous 1, except that in toner production example a, the pigment was replaced with brilliant carmine 6B (CI 15850) Mieshabu. A toner b having an average particle diameter of 8.2 μm, a coefficient of variation of 8%, and a shape factor of 5F1=132 was obtained.

Toner production example-9-1 to toner production example a toner 1-toner of Example 3 was prepared using the same composition and production method except that the pigment was replaced with 3 parts by weight of benzidine yellow (CI 21090). Average particle size 8.5 μm, coefficient of variation 5%, shape factor 5F
1=132 toner C was obtained.

Banjo: Jυ] Same composition and manufacturing method as in production example a of Masuwata toner, except that the negative charge control agent was replaced with 1.0 parts by weight of the positive charge control agent P-51 (manufactured by Orient Chemical Co., Ltd.) The average particle size of the toner of Example 4 was 8.5 μm and the coefficient of variation was 8%.
, a toner d with a shape factor of 5F1=132 was obtained.

Toner production example e In toner production example a, the particles obtained by the one-seed polymerization method used as the core material had a number average molecular weight iV1 n
= 10000, molecule 1 distribution M w / M n =
4. Using the same composition and manufacturing method as Comparative Example 1, except that the glass transition point was 63°C, the softening point was 130'C1, the coefficient of variation was 5%, the shape (number of threads 5F1 = 104, and the average particle size was 7 μm). A toner having an average particle diameter of 8.1 μm, a coefficient of variation of 8%, and a shape factor of 5F1=131 was obtained.

Toner production example f In toner production example a, except for using the microparticles obtained in Production Example 2 instead of the microparticles obtained in Production Example 1 of styrene-acrylic resin microparticles as the styrene-acrylic resin microparticles. Using the same composition and manufacturing method, the toner of Example 5, with an average particle size of 8.5 μm and a coefficient of variation of 8.
%, a toner f with a shape factor SF of 132 was obtained.

Toner production example g In toner production example a, the styrene-acrylic resin microparticles obtained in Production Example 3 were replaced with the styrene-acrylic resin microparticles obtained in Production Example 3. Using the same composition and manufacturing method except for using the foot part, the average particle size of L-ner of Example 6 was 9.1 μm.
, a variation coefficient of 9%, and a shape factor SF 1 =139.

Lord Edan Ekaku 4 Polyester
100 (dead point 423℃, gala 118
Point 65℃, AV23.0HV40) Fe-2J ferrite fin
500MFP-2 (TDKIII) Carbon black (manufactured by Mitsubishi Kasei Ohil, AM#8)
2 The above materials were thoroughly mixed and pulverized using a Henschel mixer, and then the cylinder part was heated at 180°C.
The mixture was melted and kneaded using an extrusion kneader whose cylinder head was set at 170°C. The kneaded material was allowed to cool and then ground for 4 times using a feather mill, further finely ground using a jet mill, and then classified using a classifier to obtain a carrier having an average particle size of 60 μm.

Evaluation method for toner characteristics The toners a to g of Examples 1 to 6 and Comparative Example 1 thus obtained were evaluated in various ways as described below. Conducted the first shift to evaluate the safety. In addition, each of 1-na-a-g is 1
0.00 parts by weight was post-treated with 0.1 parts by weight of colloidal silica R-972 (manufactured by Nippon Aerosil ■), and used for evaluation of properties.

Charge amount (Q/IVI> and scattering amount) Here, 2 g of the surface-treated toner and 28 g of the carrier shown above were placed in a 50CC polyethylene bottle and placed on a rotating stand for 12 hours.
In order to investigate the rise in the charge amount of the toner when rotated at 00 rl) m, the charge amount after stirring for 3 minutes, 10 minutes, and 30 minutes was measured, and the amount of scattering at that time was also investigated.

The amount of scattering was measured using a digital dust meter model P5H2 (Shide Kagaku).
It was measured with a After installing the dust meter and the magnet roll at a place with a pressure of 10 anMh and setting 2 g of developer on the magnet roll,
The dust meter reads the toner particles generated when the toner is rotated at 0 Orpm as dust, and displays the number of counts per minute (cpm).

Table 1 shows the measurement results of the amount of charge and the amount of scattering.

The specified toner and the above carrier shown in Table 2 for evaluation
A two-component developer was prepared by mixing the carrier in a ratio of 7/93. Using this developer, EP-5702 (manufactured by Minolta Camera Co., Ltd.) was used for Examples 1 to 3.5 and 6 and Comparative Example 1, and EP-4702 (manufactured by Minolta Camera Co., Ltd.) was used for Example 4.
Initial image output evaluation (and printing durability test) was performed using a fixing device manufactured by Minolta Camera Co., Ltd. that had been modified to an oil coating method, and various image evaluations shown in Table 2 were performed.

1) Fog on images As described above, various combinations of toner and carrier were used to eject both toners and carriers using the above-mentioned agitator.

Regarding fogging on images, toner fogging on white background images was evaluated and ranked. A value of Palanc or higher is practically usable, but a value of 0 or higher is desirable.

2) Translucency Translucency was measured on the fixed image on the OHP sheet obtained during the fixability test described below, and the vividness of the color in the projected image when projected with an OHP projector was visually evaluated. .

3) For printing durability test Examples 1 to 3.5 and 6 and Comparative Example 1, the above E
A 100,000-sheet printing durability test was conducted using P-5702 and EP-4702 for Example 4. 1 at this time~
The amount of charge and fog were evaluated.

4) Fixing property test In addition, the initial image was copied onto paper and an OHP sheet to evaluate the fixing property. The fixing strength is 20 using a sand eraser.
A case in which the stroke was not disturbed even after rubbing more than once was marked as ◎, 15 to 20 times as ○, 5 to 15 times as Δ, and less than that as X.

The results are shown in Table 2.

Heat Resistance Test 1 ~ 5g of each toner was placed in a 50cc polyethylene bottle, and ranked based on the aggregation property after being stored in an environment of 50°C for 24 hours. A value of Δ or more is practically possible, but a value of 0 or more is a preferable range. The results are shown in Table 1.

(Effects of the Invention) As described above, the present invention comprises a core particle made of at least a colorant and a thermoplastic resin, and an outer shell layer made of at least a synthetic resin and coated on the outer surface of the core particle. In the toner for developing electrostatic latent images, the thermoplastic resin used for the core particles has a softening point of 150°C or less, a number average molecular weight of 1000 to 15000, and a molecular weight distribution Mw.
, /Mn is 3 or less, the coefficient of variation of the particle size of the electrostatic developing toner itself is less than 15%, and the shape factor SF1 is 150 or less, and OHP
It exhibits excellent translucency for both full-color and full-color applications, and can produce clear colored images. In addition, despite having such excellent light transmittance, it has excellent heat resistance and shape stability, and has a stable and uniform charge amount, so it may cause toner aggregation or image fogging. It exhibits stable developability without causing problems such as toner scattering.

In addition, in the toner for developing electrostatic latent images of the present invention, when the toner shape has high sphericity and narrow particle size distribution as described above, even if the particle size is reduced, high fluidity and good flowability can be achieved. It shows excellent handling properties and can be expected to improve the quality of the drawing.

Claims (4)

[Claims] (1) An electrostatic latent image developing toner comprising a core particle made of at least a colorant and a thermoplastic resin, and an outer shell layer made of at least a synthetic resin and coated on the outer surface of the core particle. The softening point of the thermoplastic resin used for the particles is 150°C or less, and the number average molecular weight is 100.
0 to 15,000, the molecular weight distribution Mw/Mn is 3 or less, and the coefficient of variation of the particle size of the electrostatic development toner itself is 15%
and a shape factor SF1 of 150 or less. (2) The toner for developing electrostatic latent images according to claim 1, wherein a charge control agent is melted and fixed on the outer shell layer. (3) A patent characterized in that the core particles have a particle diameter variation coefficient of less than 10% and a shape factor SF1 of 120 or less, and the synthetic resin forming the outer shell layer is fine particles with a variation coefficient of less than 20%. The toner for developing an electrostatic latent image according to claim 1. (4) At least a colorant, a softening point of 150°C or less, a number average molecular weight of 1000 to 15000, and a molecular weight distribution Mw/M
A step of electrostatically attaching fine particles made of a synthetic resin to the surface of a core particle made of a thermoplastic resin having a particle size of n3 or less;
An electrostatic method comprising the steps of: forming an outer shell layer by melting the surface of the attached fine particles by mechanical shearing force; and melting and fixing a charge control agent on the outer shell layer. A method for producing a latent image developing toner.