JPH1195487A - Plate making method of direct drawing type lithographic printing master plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printed product of high resolution with little contamination on the base and showing excellent resistance against hot offset by using a spherical toner having a specified particle size produced by phase inversion emulsifying method to form a toner image. SOLUTION: A toner image is formed on the surface of an image accepting layer formed on a water-resistant supporting body of a direct drawing type lithographic printing master plate by using an electrophotographic copying machine or a printer. In this method of plate making for a direct drawing type lithographic printing master plate, the toner used is produced by phase inversion emulsifying method and prepared by granulating and heating to produce crosslinks in the particle. The toner has 2 to 13 μm particle size. By this plate making method for a direct drawing type lithographic printing master plate using the spherical toner of a small particle size prepared by granulating by phase inversion emulsifying method and then heating to crosslink the inner structure of the particle, the obtd. lithographic printing plate can produce a printed product showing excellent printing durability and resolution with little contamination on the base.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a direct-drawing lithographic printing plate precursor, wherein the surface of an image receiving layer provided on a water-resistant support is
The present invention relates to a plate making method for a direct-drawing lithographic printing original plate that forms and fixes a toner image using an electrophotographic copying machine or a printer.

[0002]

2. Description of the Related Art Conventionally, as a method of producing a lithographic printing plate, instead of an indirect method of producing a film by separating and outputting four colors and exposing the film to a PS plate using each film, a method using a film is used. A direct production method, that is, a method of producing a direct drawing type lithographic printing plate, has been attracting attention in terms of speed, simplicity, environmental friendliness, and the like.

[0003] As a method for producing a direct drawing type lithographic printing plate,
(1) A method of applying ink jet on a support having a hydrophilic surface (JP-A-51-84303, JP-A-56-30330)
-6215, JP-A-56-113456, etc.),
(2) Plate making method using a support having a hydrophilic surface by a wire dot method or thermal transfer (JP-A-58-193)
154, JP-A-59-76260, and (3) a method of making a plate by discharge breakdown (JP-A-54-6602,
JP-A-50-59113, JP-A-60-194467
(4) a method of removing a hydrophilic layer or a hydrophobic layer with a laser beam (for example, JP-A-50-113307), a method of making a plate in a heat mode (for example, JP-A-50-158405), (5) Methods using a thermal printing device such as a thermal head (Japanese Patent Application Laid-Open Nos. 58-199153 and 59-17
(6) a method using an organic photoconductor (for example, JP-A-60-239762) and (7) a method using a dispersion system of phthalocyanine and zinc oxide (JP-A-60-239).
No. 2401060).

However, all of these methods involve various problems and have not been industrially satisfactory. For example, the methods (1) and (2) require the use of a special ink or a transfer ribbon, and the printing durability of the image area is weak. Is not remarkably industrially advantageous,
The method (4) is not suitable for office printing because the apparatus is bulky and unsuitable for office printing. The method (5) is not satisfactory in terms of printing durability although a relatively beautiful image can be obtained. Regarding (6) and (7), although the printing plate has sufficient printing durability, the resolution of the image portion is not sufficient due to scattering of toner to be used. There has been a problem that the number of characters up to the fifth character is the limit or that toner adheres to portions other than the image portion and so-called background stain is easily generated.

When the electrostatic latent images of the above-mentioned (6) and (7) are developed from the viewpoint of the toner for developing an electrostatic image, the fixing method of developing the electrostatic latent image is as follows. In general, a fixing method using a hot roll is generally used, and toners used in the fixing method are required to provide a clear image and to be capable of fixing at high speed and at low temperature.

In order to obtain a clear image, a small particle size toner is required.

[0007] Fixing at a low temperature is made possible by lowering the molecular weight of the binder resin of the toner or lowering the glass transition temperature. However, on the other hand, if the molecular weight of the binder resin is reduced, the phenomenon called hot offset, in which toner adheres to the heat fixing roll and soils the paper, becomes significant. Further, from the viewpoint of storage stability, there is a limit in lowering the glass transition temperature of the binder resin. Therefore, in order to achieve a wide fixing temperature range while maintaining low-temperature fixability and hot offset resistance, the binder resin is composed of both low molecular weight components and high molecular weight components or partially crosslinked ultra-high molecular weight components. Is required.

At present, in the pulverization method, which is the most common method for producing toner, a method in which a low molecular weight component and a high molecular weight component are used in combination as a binder resin for toner (Japanese Patent Publication No. 63-32).
180, Japanese Patent Publication No. 55-6895, etc., and a method in which a low molecular weight component and a partially crosslinked ultra-high molecular weight component are used in combination (Japanese Patent Publication No. Sho.
0-36582, JP-A-01-219765, etc., and a method of crosslinking at the time of melt-kneading (JP-B-59-33907;
Japanese Patent Laid-Open No. 06-222612, Japanese Patent Publication No. 60-38700, etc.) correspond to hot offset resistance.

However, in any technology,
Since a high molecular weight or partially crosslinked resin is melted and kneaded, then cooled and then pulverized, there is a disadvantage that the power must be extremely enormous. Furthermore, the pulverization method is inherently difficult to reduce the particle size, and the difficulty is further increased in producing a small particle size toner using a high molecular weight or partially crosslinked resin which is difficult to pulverize. There is also the disadvantage of getting it. In addition, if the particle size is forced to be reduced, a large amount of non-standard fine powder will be generated, and a considerable loss will occur in classification.

That is, in the pulverization method, there is a limit in reducing the particle diameter from the viewpoint of productivity, and in order to meet the latest demands in the market, such as the current average particle diameter of 10 μm to 7 μm or 5 μm. Not suitable.

On the other hand, the polymerization method is a method in which a radical polymerizable monomer is polymerized in an aqueous medium in the presence of a colorant. Therefore, by using a crosslinkable monomer such as divinylbenzene, the molecular weight and crosslinkage are relatively easy. Can be controlled. In addition, it is possible to cope with a reduction in particle size.

However, in the polymerization method toner, in order to stabilize the dispersion of the particles, a compound having an extremely high hydrophilicity such as a surfactant or a protective colloid must be used.
Therefore, if it is dried as it is to obtain toner particles,
Moisture absorption results in extremely poor charging stability and environmental stability. Therefore, in order to eliminate the disadvantage, it is necessary to wash, but it is practically impossible to completely remove it. That is, in the production by the polymerization method, there is a disadvantage that sufficiently solving the charging stability and the environmental stability has a problem in terms of productivity.

Incidentally, the method for producing a toner by the phase inversion emulsification method is a new technique whose basic technique has been disclosed for the first time in JP-A-05-66600 and JP-A-05-265247. An outline of the production method is a method of dispersing an organic solvent solution of a resin having a hydrophilic group and having self-water dispersing ability and a colorant in an aqueous medium to form particles.

The feature is that colored spherical fine particles can be easily produced without consuming a large amount of energy such as pulverization, and small-sized particles can be produced very easily. Further, those having a sharp particle size distribution can be easily produced. Furthermore, since neither a surfactant nor a protective colloid is used, there is no problem in charge stability and environmental stability which are disadvantages of the polymerization method.

However, according to the conventional knowledge, the phase inversion emulsification method using neither a surfactant nor a protective colloid uses an organic solvent solution of the resin, so that a crosslinked resin cannot be used. If the molecular weight of the resin is too high, phase inversion emulsification is difficult. In the case of a vinyl copolymer, in order to achieve good phase inversion emulsification, the weight average molecular weight is generally limited to about 200,000.

Therefore, in order to improve the hot offset resistance, a technique in which low-molecular-weight resin and high-molecular-weight resin are applied in combination and filed in Japanese Patent Application No. 07-119799,
A technique disclosed in Japanese Patent Application Laid-Open No. 06-258869, in which a toner containing a crosslinking agent produced by a phase inversion emulsification method is crosslinked at the time of fixing with a hot roll, has been proposed, but the hot offset resistance is still insufficient. . That is, the toner produced by the conventional phase inversion emulsification method has a drawback that the hot offset resistance is insufficient.

Therefore, as long as the conventional technology described above is followed, there is no problem such as charge stability and environmental stability, and it is easy to reduce the particle size of the particles, and the spherical shape is excellent in the heat fixing property, particularly, the hot offset resistance. No toner could be produced.

[0018]

On the other hand, with the remarkable progress of the equipment in recent years, the resolution of the electrophotographic copying machine and the printer has been reduced from the conventional 300 dpi to 800 dpi.
In order to obtain a high quality printing plate, there is a great demand for a toner having good properties. Accordingly, an object of the present invention is to meet the advance of these copiers and printers, to eliminate problems such as charging stability and environmental stability, to easily reduce the particle size of the particles, and to set the heat fixing property, Excellent hot offset,
It is an object of the present invention to provide a plate making method of a good direct-drawing lithographic printing plate precursor which can obtain a high-resolution printed matter with less background smear using a new type of spherical toner by a phase inversion emulsification method.

[0019]

SUMMARY OF THE INVENTION The object of the present invention is to provide a direct drawing type lithographic printing plate precursor in which a toner is formed on an image receiving layer provided on a water-resistant support by using an electrophotographic copying machine or a printer. When forming an image, a plate of a direct-drawing lithographic printing plate precursor is produced by using a toner having a particle diameter of 1 to 15 microns, which is produced by a phase inversion emulsification method and then heated after granulation to cause crosslinking within the particles. Achieved by doing.

As a method for producing a toner produced by the phase inversion emulsification method of the present invention and subjected to heating after granulation to crosslink the particles, a resin having at least two or more crosslinkable functional groups on average per molecule is used. After preparing a liquid medium dispersion of particles containing a colorant therein with a resin crosslinker as a resin component, a part of the resin component is crosslinked to form a binder resin. This is a production method in which the particles whose part has been crosslinked are separated from the liquid medium and dried, and basically comprises the following three steps. 1) A step of preparing a liquid medium dispersion of particles containing a colorant in a resin having a resin having at least two or more crosslinkable functional groups on average per molecule and a crosslinking agent of the resin as a resin component. 2) a step of crosslinking a part of the resin component in the particles dispersed in the liquid medium; 3) Next, a step of separating and drying the obtained partially crosslinked particles from a liquid medium.

The liquid medium dispersion of the present invention comprises a resin (A) having a functional group which increases hydrophilicity by neutralization and a crosslinkable functional group having at least one molecule on average and which can be made water-dispersible by neutralization. A crosslinking agent (B) for the resin (A), a coloring agent (C), an organic solvent (D), and a neutralizing agent (E) sufficient to make the resin (A) water-dispersible. The mixture is obtained by phase inversion emulsification in an aqueous medium. A resin having at least one or more crosslinkable functional groups having an average molecular weight of 2 or more and a crosslinking agent of the resin as a resin component, and a colorant is dispersed therein. Aqueous dispersion of the particles obtained.

[0022]

Embodiments of the present invention will be described below in detail. As the resin of the resin (A) of the present invention, for example,
There are a polyester resin, an epoxy resin, a polyurethane resin and a vinyl copolymer, and any of them can be used. Among them, a vinyl copolymer is preferable, and an aromatic vinyl copolymer is more preferable.

Examples of the vinyl copolymer in the present invention include copolymers obtained by copolymerizing an aromatic vinyl monomer as a preferable component and other copolymerizable monomers. Examples of the aromatic vinyl monomer include styrene, vinyltoluene, and α-methylstyrene.

Other copolymerizable monomers include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, isoamyl ( (Meth) acrylate, 2-ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, butoxymethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, S- (meth) acrylates such as benzyl (meth) acrylate, cetyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate and isobornyl (meth) acrylate Vinyl esters such as vinyl acetate, vinyl benzoate, vinyl versatate and vinyl propionate; polymerizable nitriles such as (meth) acrylonitrile; vinyl fluoride, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, Vinyl monomers having a fluorine atom such as chlorotrifluoroethylene and (meth) acrylate having a fluorine-containing alkyl group; diethylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, N-vinylimidazole and N-
Tertiary amino group-containing monomers such as vinyl carbazole; 2- (2′-hydroxy-5-methacryloyloxyethylphenyl) -2H-benzotriazole, 2-hydroxy-4- (2-methacryloyloxyethoxy) benzophenone and Monomers having ultraviolet absorbing or antioxidant properties such as 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate; N-vinylpyrrolidone, diacetoneacrylamide, N-methylolacrylamide, N-butoxymethyl (meth- ) Functional group-containing monomers such as N-alkoxymethyl (meth) acrylamide such as acrylamide; 2-phosphoxyethyl (meth) acrylate and 4-oxybutyl (meth)
Phosphoric acid group-containing monomers such as acrylates; macromonomers having one polymerizable unsaturated group at one terminal of the molecule; Also, polyfunctional radically polymerizable monomers such as divinylbenzene and ethylene glycol di (meth) acrylate can be used as long as they do not adversely affect the phase inversion emulsification. Of course, polymerizable monomers having a carboxyl group or a hydroxyl group described below can also be used.

As the method for copolymerizing the polymerizable vinyl monomer, various known polymerization methods such as suspension polymerization, emulsion polymerization, bulk polymerization, and solution polymerization can be used, but solution polymerization is preferred because it is simple.

As the polymerization initiator, known peroxides and azo compounds can be used. For the purpose of adjusting the molecular weight, a polyfunctional polymerization initiator having two or more peroxy groups or two or more azo groups, or a known chain transfer agent can also be used.

As the polyester resin in the present invention, a compound having a carboxyl group or an ester-forming functional group such as a monobasic acid, a dibasic acid or a polybasic acid and a compound having a hydroxyl group such as a diol or a polyol are appropriately selected. And dehydration-condensed.

Examples of the dibasic acid or polybasic acid include (phthalic anhydride), isophthalic acid, terephthalic acid,
Tetrahydro (anhydride) phthalic acid, hexahydro (anhydride)
Phthalic acid, hexahydroterephthalic acid, 2,6-naphthalenedicarboxylic acid, trimellitic acid (anhydride), (anhydrous)
Aromatic acids such as pyromellitic acid are typical, but some acids such as adipic acid, succinic acid (anhydride), sebacic acid, dimer acid, and maleic acid (anhydride) must also be used. Can be. Further, compounds having a hydroxyl group and a carboxyl group such as dimethylolpropionic acid, p-hydroxybenzoic acid and ε-caprolactone can also be used.

Compounds having a carboxyl group that can be used other than dibasic acids or polybasic acids include, for example, lower alkyl esters of acids such as dimethyl terephthalate;
Monobasic acids such as benzoic acid, p-tert-butylbenzoic acid, rosin, and hydrogenated rosin; macromonomers having one or two carboxyl groups at molecular terminals;
And sodium sulfoisophthalic acid and dimethyl esters.

Examples of the compound having a hydroxyl group include an alkylene oxide adduct of bisphenol A, hydrogenated bisphenol A, an alkylene oxide adduct of hydrogenated bisphenol A, 1,4-cyclohexanedimethanol, ethylene glycol, neopentyl glycol, and propylene glycol. , Diethylene glycol, dipropylene glycol, 2-methyl-1,3-propanediol, 2,
2-diethyl-1,3-propanediol, 1,4-butanediol, 1,3-propanediol, 1,6-hexanediol, 1,5-pentanediol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc. Diols, glycerin, trimethylolpropane, trimethylolethane,
Polyols such as diglycerin, pentaerythritol and trishydroxyethyl isocyanurate,
Monoglycidyl compounds such as "Kajura E-10" (glycidyl ester of a synthetic fatty acid manufactured by Shell Chemical Industry Co., Ltd.), macromonomers having one or two hydroxyl groups at molecular terminals, and the like. Part of the dibasic acid can be replaced with a diisocyanate compound.

The polyester resin of the present invention may be various modified polyester resins, for example, a vinyl-modified polyester resin grafted with a vinyl monomer, a silicon-modified polyester resin, and the like.

The polyurethane resin of the present invention can be produced by reacting a polyol component with a polyisocyanate component.

As the polyol component, in addition to the diol components listed in the method for producing the polyester resin, high molecular polyols such as polyester diol, polycaprolactone diol, polycarbonate diol, and polysiloxane diol, and, if necessary, a trifunctional or higher functional polyol compound Can also be used.

The polyisocyanate component includes 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, phenylene diisocyanate, 1,5-naphthalene diisocyanate,
Meta-xylylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated 4,
In addition to diisocyanate compounds such as 4'-diphenylmethane diisocyanate, hydrogenated meta-xylylene diisocyanate and crude 4,4'-diphenylmethane diisocyanate, polyisocyanate compounds such as polymethylene polyphenyl isocyanate can also be used.

The production of the polyurethane resin may be in accordance with a conventional method. For example, a method in which the addition reaction is performed at a temperature of about room temperature to about 100 ° C. in an inert organic solvent that does not react with the isocyanate group is preferable. At that time, a known catalyst such as dibutyltin dilaurate may be used.

The epoxy resin in the present invention is typically a bisphenol A type epoxy resin. Also,
A modified epoxy resin grafted with a vinyl monomer can also be used.

The resin (A) used in the present invention comprises:
It is necessary to have a functional group that increases hydrophilicity by neutralization and at least one crosslinkable functional group having an average of at least one molecule,
The type and introduction method will be described.

Functional groups that increase hydrophilicity by neutralization include:
Examples of the cationic group include an amino group, particularly preferably a tertiary amino group, and examples of the anionic group include a phosphate group, a sulfone group, and a sulfate group, and particularly preferably a carboxyl group.

In order to introduce a preferable tertiary amino group as a cationic group into the resin, for example, in the case of a vinyl copolymer, dimethylaminoethyl (meth) acrylate,
A method of copolymerizing a radically polymerizable monomer having a tertiary amino group such as diethylaminoethyl (meth) acrylate and vinylpyridine, and a copolymer of a polymerizable monomer having a glycidyl group such as glycidyl (meth) acrylate and dibutylamine And a method of adding a secondary monoamine.

In the case of introduction into an epoxy resin, a method of adding a secondary monoamine such as dibutylamine to a glycidyl group may be mentioned. When introduced into a polyester resin or a polyurethane resin, a tertiary amine compound having a hydroxyl group such as triethanolamine, N-methyldiethanolamine, N, N-dimethylethanolamine may be used as a part of the alcohol component during resin synthesis. I just need.

Next, an example of a method for introducing a carboxyl group, which is preferable as an anionic group, into a resin will be described.

The vinyl copolymer having a carboxyl group can be easily produced by copolymerizing a polymerizable monomer composition containing a polymerizable monomer having a carboxyl group.

Examples of the polymerizable monomer having a carboxyl group include acrylic acid, methacrylic acid, crotonic acid, fumaric acid, itaconic acid, maleic acid, monoalkyl maleates such as monobutyl maleate, and itacone such as monobutyl itaconate. Monoalkyl acid and the like.

Other methods include adding a monoalcohol such as butyl alcohol to an acid anhydride group-containing copolymer obtained by copolymerizing a polymerizable monomer having an acid anhydride group such as maleic anhydride; It is also possible to introduce a carboxyl group by a method of adding an acid anhydride group-containing compound such as maleic anhydride, phthalic anhydride, or trimellitic anhydride to a hydroxyl group-containing vinyl copolymer obtained by copolymerizing a monomer. it can.

As the polyester resin having a carboxyl group, a compound having a carboxyl group such as a monobasic acid, a dibasic acid or a tribasic or higher polybasic acid and a compound having a hydroxyl group such as a diol or a polyol are appropriately selected. When a polyester resin is produced by dehydration condensation by a known method such as a melting method and a solvent method, the reaction may be carried out so that a carboxyl group remains. The carboxyl group is an unreacted carboxyl group mainly derived from a dibasic acid or polybasic acid constituting the polyester resin.

As another method for introducing a carboxyl group into a polyester resin, for example, a linear or branched polyester resin having a hydroxyl group is mixed with an acid anhydride group-containing compound such as maleic anhydride, phthalic anhydride or trimellitic anhydride. A method of addition, a method of reacting a polyester resin having a hydroxyl group, preferably a linear polyester resin with a tetracarboxylic dianhydride such as pyromellitic anhydride, for example, to introduce a carboxy group and extend the chain simultaneously can be adopted.

Further, a carboxyl group can also be introduced into the polyester resin by a method of graft-polymerizing a polymerizable monomer containing the above-mentioned polymerizable monomer having a carboxyl group.

The polyurethane resin having a carboxyl group can be easily prepared by reacting a polyol component containing a compound having both a carboxyl group and a hydroxyl group such as dimethylolpropionic acid as a component for introducing a carboxyl group with a polyisocyanate component. Can be manufactured.

The resin (A) in the present invention needs to have a crosslinkable functional group in addition to a functional group which increases hydrophilicity by neutralization, such as a carboxyl group.

The resin having at least two crosslinkable functional groups on average per molecule is used in combination with a crosslinking agent for the resin to crosslink a part of the resin to form a binder resin. These are selected and used so that the crosslinkable functional group of the resin and the functional group involved in the crosslinking of the crosslinking agent chemically react with each other and crosslink.

The resin having at least two crosslinkable functional groups on average per molecule is preferably a resin having a functional group which increases hydrophilicity by neutralization and a crosslinkable functional group and which can be made water-dispersible by neutralization. In certain cases, the following combinations can be employed in the present invention with respect to the crosslinkable functional group and the crosslinking agent in such a resin.

1) When the crosslinkable functional group is a carboxyl group, examples of the crosslinking agent include aminoplast resins, compounds having an average of two or more glycidyl groups in one molecule, and 1,3-dioxolane-one in one molecule. Compounds having an average of two or more 2-on-4-yl groups, compounds having an average of two or more carbodiimide groups in one molecule, compounds having an average of two or more oxazoline groups in one molecule, metal chelate compounds, and the like. Can be

2) When the crosslinkable functional group is a hydroxyl group, examples of the crosslinking agent include aminoplast resins, polyisocyanate compounds and blocked polyisocyanate resins.

3) When the crosslinkable functional group is a tertiary amino group, examples of the crosslinking agent include a compound having an average of two or more glycidyl groups in one molecule and 1,3 in one molecule.
And a compound having an average of two or more dioxolan-2-one-4-yl groups.

4) When the crosslinkable functional group is a glycidyl group or a 1,3-dioxolan-2-one-4-yl group,
Examples of the crosslinking agent include compounds having an average of two or more carboxyl groups in one molecule, polyamine compounds and polymercapto compounds.

Next, a method for introducing a crosslinkable functional group into a resin will be described. When the crosslinkable functional group is a carboxyl group or a tertiary amino group, the same method as described in the section for introducing a functional group that increases hydrophilicity by neutralization may be used.

The vinyl copolymer having a hydroxyl group as a crosslinkable functional group can be easily produced by copolymerizing with a polymerizable monomer having a hydroxyl group.
Examples of the polymerizable monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, “Placcel FM-2” and “Placcel FA-2” ( (Meth) acrylic monomers to which a lactone compound represented by Daicel Chemical Industries, Ltd.) is added; and polyethylene glycol mono (meth) acrylate monomers, polypropylene glycol mono (meth) acrylate monomers, hydroxyethyl vinyl ether, Representative examples include xylbutyl vinyl ether.

The polyester resin having a hydroxyl group as a crosslinkable functional group can be easily produced by a dehydration condensation reaction of the polyester resin according to a known method so that the hydroxyl group remains.

A vinyl copolymer having a 1,3-dioxolan-2-one-4-yl group as a crosslinkable functional group is:
It can be easily produced by copolymerizing a polymerizable monomer having a 1,3-dioxolan-2-one-4-yl group in combination. Examples of the polymerizable monomer having a 1,3-dioxolan-2-one-4-yl group include 1,1
3-dioxolan-2-one-4-ylmethyl (meth)
Acrylate, 1,3-dioxolan-2-one-4-
Il methyl vinyl ether and the like.

In the present invention, resin synthesis, handling,
Because of the ease of design and the ease of increasing the molecular weight or the cross-linking reaction, both the functional group that increases hydrophilicity by neutralization and the cross-linkable functional group are carboxyl groups, and the cross-linking agent (B) has an average molecular weight of 2 Compounds having at least two glycidyl groups are preferred.

As typical examples of compounds having two or more glycidyl groups in one molecule, phenols such as bisphenol A epoxy resin, bisphenol F epoxy resin and hydrogenated bisphenol A epoxy resin are exemplified. Glycidyl ethers; glycidyl ethers of various glycols and polyols such as neopentyl glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, polypropylene diglycidyl ether, trimethylolpropane diglycidyl ether, sorbitol polyglycidyl ether; adipin Esters such as acid diglycidyl ester and phthalic acid diglycidyl ester; polymerizable with glycidyl group such as glycidyl (meth) acrylate Vinyl copolymer obtained by copolymerizing Nomar; epoxidized polybutadiene.

In the present invention, the resin (A)
The reaction between the polymer and the crosslinking agent (B) is carried out in a liquid medium, preferably in an aqueous medium, so that the temperature is preferably equal to or lower than the boiling point of water. It is preferable to carry out at a temperature not much higher than the temperature.

Compounds having two or more glycidyl groups on average per molecule, which are preferable to react under mild conditions at relatively low temperatures, include, for example, diglycidylaniline, triglycidylparaaminophenol, triglycidylmethaminophenol, A glycidylamine compound such as glycidylaminodiphenylmethane is preferred, and a glycidylamine compound having a —N (alkyl) glycidyl group or a —N diglycidyl group at the molecular terminal is most preferred.

Examples of such most preferred crosslinking agents include N, N, N ', N'-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, Representative examples include N, N-diglycidylbenzylamine, N, N-diglycidyl-α-phenylethylamine, N, N, N ′, N′-tetraglycidylisophoronediamine.

The number of glycidyl groups contained in the cross-linking agent is preferably 2 to 6 in one molecule, more preferably 2 to 4 in one molecule. If the number of glycidyl groups is less than 2, the molecular weight or cross-linking reaction does not proceed sufficiently, and if it is more than 6, some of the cross-linking density is undesirably high.

When both the functional group that increases hydrophilicity by neutralization and the crosslinkable functional group of the resin (A) are carboxyl groups, the amount of the carboxyl group is determined by the acid value (for neutralizing 1 g of resin solids). The required amount of KOH (expressed in mg) will be preferably in the range of 10 to 150 mg (KOH) / g.

When the acid value is less than 10, the phase inversion emulsifying property in an aqueous medium is reduced, and further, the increase in the molecular weight or the crosslinking reaction does not proceed sufficiently. Both of these are not preferred because the hygroscopicity is increased.

The resin (A) is a DSC (differential scanning calorimeter)
Glass transition temperature (hereinafter, glass transition temperature is D
Expressed by the value measured by SC. ) Is preferably in the range of 40 to 80 ° C.

The weight average molecular weight of the resin (A) (hereinafter, the molecular weight is represented by a value measured by gel permeation chromatography in terms of polystyrene) is from 5,000 to 200,000 in the case of a vinyl copolymer. The range is preferably from 20,000 to 150,000.
A range of 0 is more preferable. In the vinyl copolymer, when the weight average molecular weight is less than 5,000, the hot offset resistance does not improve so much even when a high molecular weight and cross-linking reaction is performed, and when the weight average molecular weight is more than 200,000. However, the phase inversion emulsifying property is deteriorated, which is not preferable.

On the other hand, in the case of polyester resin, polyurethane resin and epoxy resin, 2,000 to 50,
000 is preferable.

The ratio between the resin having an average of at least two crosslinkable functional groups in one molecule and the crosslinking agent is not particularly limited, but both the functional groups and the crosslinkable functional groups are carboxyl groups. Taking a self-water-dispersible resin obtained by neutralizing a functional group of a resin which can be made water-dispersible by neutralization as an example, simply, 1 equivalent of the total carboxyl group of the functional group and the crosslinkable functional group When converted to, it is preferable to use a glycidyl group-containing compound in an amount within the range of 0.001 to 0.5 equivalent of glycidyl group, and further,
An amount in the range of 0.01 to 0.3 equivalent is more preferable. Strictly, it is preferable to calculate based on the amount of the functional group.

If the amount of the glycidyl group is less than 0.001 equivalent, the molecular weight or crosslinking becomes insufficient, and if the amount is more than 0.5 equivalent, the crosslinking proceeds excessively and the fixability of the toner becomes poor. Both are not preferred because they will decrease.

Colorant (C) used in the present invention
Any of dyes, pigments, and the like, which have been conventionally used as toner materials, can be used. Particularly representative examples include zinc white, yellow iron oxide, Hansa Yellow, Disazo Yellow, Quinoline Yellow, Permanent Yellow, Permanent Red, Bengala, Lisor Red, Pyrazolone Red, Lake Red C, Lake Red D, and Brilliant. Various pigments such as Carmine 6B, Brilliant Carmine 3B, navy blue, phthalocyanine blue, metal-free phthalocyanine, titanium oxide, carbon black or magnetic powder, or oil-soluble dyes.

Further, these pigments may be those which have been previously treated with a resin or a coupling agent in order to improve their functionality. Further, extenders such as calcium carbonate, barium sulfate, clay and kaolin may be used in combination with the coloring agent as described above.

The materials constituting the toner according to the present invention have been described above. Next, a liquid medium dispersion of particles containing a colorant, which is the first production step of the present invention, is prepared. In the process, a preferred method is
The resin (A) which can be made water-dispersible by the neutralization, the crosslinking agent (B) of the resin (A), the coloring agent (C), the organic solvent (D), and the resin (A) are dispersed in water. A method of phase-inverting and emulsifying a mixture containing a neutralizing agent (E) sufficient to render the mixture insoluble in an aqueous medium will be described.

First, a solution of the resin (A) and / or the crosslinking agent (B) in the organic solvent (D) and the colorant (C) are sufficiently kneaded by a known method, and then transferred to an aqueous medium. Phase emulsification is performed to produce dispersed particles. At this time, the coloring agent (C)
After dispersing with another resin, it may be mixed with a solution of the resin (A) and / or the crosslinking agent (B) in the organic solvent (D).

Further, as long as the effects of the present invention are not impaired, other resins and additives may be mixed, dispersed in an aqueous medium, and incorporated into particles.

Examples of the organic solvent (D) include various hydrocarbons such as toluene, xylene, benzene, n-hexane, cyclohexane and n-heptane; methanol,
Isopropanol, n-propanol, ethanol, n
-Butanol, isobutanol, sec-butanol,
alcohols such as tert-butanol; propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monoisopropyl ether, propylene glycol mono-n-
Ether alcohols such as butyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol mono-n-butyl ether; various ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; butyl acetate, acetic acid Various esters such as ethyl and isopropyl acetate; various ether esters such as propylene glycol monoethyl ether acetate and ethylene glycol monoethyl ether acetate; ethers such as tetrahydrofuran; and halogen-containing hydrocarbons such as methylene chloride. .

Among them, it is preferable to use a so-called low-boiling solvent such as acetone, methyl ethyl ketone, ethyl acetate, isopropanol and n-propanol, which can be easily removed in a step described below. Of course, two or more solvents may be used in combination.

The solvent used for synthesizing and dissolving the resin (A) may be different from the solvent (D) used for phase-inversion emulsification in an aqueous medium. And the same solvent.

For phase inversion emulsification in an aqueous medium, the resin (A) may be dispersed in an aqueous medium using an emulsifier or a dispersion stabilizer such as a protective colloid. Then, a method of forming a salt structure and dispersing it in an aqueous medium is preferable.Among them, a resin having a carboxyl group, which is a functional group that increases hydrophilicity by neutralization, is neutralized with a basic compound to form a resin. Is a method of imparting hydrophilicity to such an extent that it can be stably dispersed in an aqueous medium, which has few problems in charging stability and environmental stability, and further, does not require a separate washing step, or is relatively simple. -It is preferable because it requires only a short washing time.

As the resin having at least two crosslinkable functional groups on average per molecule, it has only at least two crosslinkable functional groups on average per molecule and has water dispersibility with or without neutralization. In the case of using no resin, a dispersion stabilizer such as an emulsifier or a protective colloid becomes an essential component, and for example, it is necessary to separately provide a new washing step.

The functional group which increases hydrophilicity by neutralization and at least two crosslinkable functional groups having an average of at least one molecule, which are examples of the resin (A), are both carboxyl groups and carboxyl groups which can be made water-dispersible by neutralization. As a method of dispersing a mixture of a resin having a group, a crosslinking agent (B), a coloring agent (C), and an organic solvent (D) in an aqueous medium by phase inversion emulsification,
For example, the following method is appropriate.

1) A neutralizing agent (E) is added to the mixture, which is then dispersed in an aqueous medium. 2) Add neutralizing agent (E) to the mixture and then add aqueous medium to it. 3) Disperse the mixture in an aqueous medium containing a neutralizing agent (E). 4) To the mixture is added an aqueous medium containing a neutralizing agent (E).

The resin having a functional group which increases hydrophilicity by neutralization forms a salt structure by neutralizing with a necessary amount of a neutralizing agent (E) having a polarity opposite to that of the functional group, thereby forming an emulsifier or a dispersion stabilizer. Even if not used, it becomes a resin dispersed in an aqueous medium (this resin is a self-water-dispersible resin).

[0086] Of the above methods 1) to 4), the method 2) may be such that the finally obtained spherical particles containing a partially crosslinked colorant have a narrower particle size distribution. It is preferable because it can be performed.

In order to form a salt structure, the neutralizing agent (E) used here may be a base when the functional group which increases hydrophilicity by neutralization in the resin (A) is an acid group. When the functional compound is also a base having a functional group, an acidic compound is used. Typical basic compounds that can be used include, for example, volatile amines such as ammonia, triethylamine, tributylamine and dimethylethanolamine; and inorganic bases such as sodium hydroxide and potassium hydroxide. No. Examples of the acidic compound include organic acids such as formic acid, acetic acid, and toluenesulfonic acid, and inorganic acids such as hydrochloric acid, sulfuric acid, and phosphoric acid.

At the time of phase inversion emulsification in an aqueous medium, a dispersant such as a surfactant or a protective colloid may be used within a range that does not adversely affect the properties of the toner and the subsequent steps.

In addition, if the shear is applied to the phase inversion emulsification in the aqueous medium so long as the mixture is homogeneously stirred, no special measures need to be taken. In some cases, a high shear dispersion such as a homogenizer or the use of ultrasonic waves may be used.

By the way, the aqueous medium in the present invention is
Water as a main component, other as necessary, water-soluble solvent,
Represents those containing a dispersion stabilizer, a neutralizing agent, and other additives.

The control of the particle size, which is important in the production of toner, is controlled mainly by the amount of a base that neutralizes the carboxyl group in the method of the present invention where a carboxyl group is used as a functional group. . The amount of neutralization by a base is 5 to 100 mol% of carboxyl groups.
By varying within a certain range, particles having a particle size from submicron (less than 1 μm) to about 30 μm can be easily and arbitrarily obtained.

The ease of controlling the particle size is one of the features of the toner production method by the phase inversion emulsification method, and particles having a particle size of 5 μm, which is recently considered as a high resolution toner, or smaller than that required in the future. To
We can respond immediately.

The liquid medium dispersion of the colored spherical fine particles undergoes a crosslinking reaction as the second step of the present invention. The crosslink of the present invention is
Occurs in the formed particles. At this time, the reaction was carried out in an unreacted state and uniformly dispersed in the particles.
Occurs between a resin having more than one crosslinkable functional group and its crosslinking agent.

It is preferable that the liquid medium is an aqueous medium, since the crosslinking reaction can be performed mildly. When the liquid medium of the particle dispersion is an aqueous medium, and the resin having at least one cross-linkable functional group having an average molecular weight of 2 or more has a salt structure in which the functional group is neutralized with a neutralizing agent, Is involved in only the other crosslinkable functional group, and the crosslinking can ensure the dispersion stability of the particle dispersion.

The crosslinking reaction is preferably carried out at a temperature below the boiling point of the aqueous medium and at a temperature not much higher than the glass transition temperature of the particles in order to avoid fusing of the particles.
Generally, in the range of 40 to 100 ° C, more preferably 50 to 100 ° C.
It is preferable to carry out at a temperature in the range of 90 ° C. The crosslinking time may be any time required for the completion of the crosslinking reaction.
It is 0 minute to 24 hours, preferably 1 to 10 hours. Specifically, there is a method of maintaining the particle dispersion at a predetermined temperature for a time required for the crosslinking reaction to be completed.

As the resin (A), a resin having at least two crosslinkable functional groups on an average of at least one molecule is used, and the crosslinking agent (B) of the resin (A) has an average molecular weight of at least two.
In order to react the carboxyl group and the glycidyl group under a mild condition at a relatively low temperature, which is represented by the case of using a compound having two or more glycidyl groups, it is preferable to use the glycidylamine compound as described above. Preferably, a glycidylamine compound, and also in other glycidyl group-containing compounds, use of a known catalyst such as 2-methylimidazole or addition of a secondary monoamine such as dibutylamine to a part of the glycidyl group. In addition, a method of imparting an autocatalytic ability to the glycidyl group-containing compound may be employed.

The cross-linking reaction is carried out after preparing an aqueous medium dispersion of colored spherical fine particles and performing various post-treatments as necessary.
In the entire process of separating and drying the particles from the aqueous medium,
After preparing an aqueous medium dispersion of particles, and may be performed at any stage before the step of separating and drying the particles from the aqueous medium, in order to prevent fusion of the particles, the solvent is removed. It is preferable to carry out after the above.

The preferred method for producing the spherical toner particles used in the present invention is as follows. The method for producing the spherical toner particles includes a functional group which increases hydrophilicity by neutralization and at least two or more crosslinkable functional groups on average per molecule. Resin (A) that can be
A mixture containing a crosslinking agent (B) of the resin (A), a coloring agent (C), an organic solvent (D), and a neutralizing agent (E) sufficient to make the resin (A) water-dispersible. The colorant is dispersed in a resin having, as a resin component, a resin having at least one or more crosslinkable functional groups having an average molecular weight of 2 or more and a crosslinker of the resin obtained by performing phase inversion emulsification in an aqueous medium. After preparing the aqueous medium dispersion liquid of the spherical particles, a part of the resin component is crosslinked to form a binder resin, and the partially crosslinked particles are separated from the aqueous medium and dried.

Further, the functional group of the resin (A) which increases hydrophilicity by neutralization and at least two crosslinkable functional groups having an average of at least one molecule are both carboxyl groups, and the crosslinking agent (B) of the resin (A) is Is more preferably a compound having at least one glycidyl group in one molecule, more preferably a compound having at least two glycidyl groups in one molecule, particularly -N (alkyl) glycidyl at the molecular terminal. Most preferred is a method for producing a glycidylamine compound having an average of 2 to 4 groups or -N diglycidyl groups per molecule.

Examples of post-treatment steps performed before or after the above-mentioned cross-linking step, as necessary, include, for example, a desolvation step by distillation under reduced pressure, a filtration and washing step, and a functional group which can be made hydrophilic by neutralization. A step of reverse neutralizing a salt-formed functional group formed by neutralization with a polar neutralizing agent (E) with a neutralizing agent (E) having the same polarity as the functional group (for example, with a base) A step of returning the neutralized carboxyl group to a carboxyl group with an acid).

Among them, a functional group which can be made hydrophilic by neutralization is neutralized with a neutralizing agent (E) having the opposite polarity to improve the moisture resistance of the toner and improve the charge stability and environmental stability. A step of reverse neutralizing the salt-formed functional group thus formed with a neutralizing agent (E) having the same polarity as the functional group (for example,
The step of returning a carboxyl group neutralized with a base to a carboxyl group with an acid) is preferably performed.
In this method, a neutralizing agent (E) having the same polarity as the functional group may be added to the aqueous dispersion of the self-water-dispersible resin particles containing the colorant, and the generated salt is easily removed by washing with water. it can.

In the above step, for example, when the functional group is a carboxyl group, the salt-formed functional group formed by neutralization with a basic compound is converted into the original carboxyl group by adding an acidic compound. Can be.

A neutralizing agent having the same polarity as that of the functional group is added to a state in which the functional group that increases hydrophilicity by neutralization is neutralized with a neutralizing agent (E) having the opposite polarity to form a salt structure to increase the hydrophilicity. Before adding, resins and additives having the same salt structure as described above, additives, waxes and the like are added in advance, and then
By adding a neutralizing agent having the same polarity as the functional group, the particle surface can be variously modified.

For example, when the functional group is a carboxyl group, resins, additives, waxes, etc. having a carboxyl group in the form of a salt formed by neutralization with a basic compound are added in advance. Then, the above step can be performed by adding an acid.

After the crosslinking step and, if necessary, the post-treatment step, finally, the particles are separated from the aqueous medium and dried to obtain powdered spherical toner particles. Drying may be performed by a known method, for example, hot air drying, spraying.
Drying, freeze drying and the like can be adopted.

As the resin for binding the crosslinked particles in the present invention, for example, those having an insoluble component having a value of 0.1% by weight or more after 24 hours of Soxhlet extraction using tetrahydrofuran (insoluble resin only) And / or the molecular weight of the component soluble in tetrahydrofuran is determined by crosslinking with a crosslinking agent, the weight average of at least one molecule of the resin having at least two crosslinkable functional groups used. Those at least higher than the molecular weight are mentioned.

The spherical toner particles thus obtained are 40
Those having a glass transition temperature in the range of -80 ° C are preferred. Further, the insoluble component obtained by Soxhlet extraction using tetrahydrofuran is preferably in the range of 0.5 to 70% by weight.

Further, regarding the molecular weight, it is necessary that the weight-average molecular weight of the tetrahydrofuran-soluble component is at least higher than the weight-average molecular weight of the resin having at least one molecule-average two or more crosslinkable functional groups. .

In particular, when a vinyl copolymer is used, the molecular weight of the binder resin is from 5,000 to 20.
More preferably, it has one peak at 000 and at least one peak or shoulder at 200,000 or more, especially 500,000 or more.

On the other hand, when a polyester resin, an epoxy resin and a polyurethane resin are used, the molecular weight of the binder resin has one peak at 2,000 to 30,000 and at least one peak or shoulder at 30,000 or more. Are preferred.

Particularly preferred are 10 to 150 mg (K
OH) / g carboxyl group acid value,
A resin having a weight average molecular weight in the range of 000, a glass transition temperature of 40 to 80 ° C. and having at least two crosslinkable functional groups on the average of at least one molecule, and a glycidyl group of at least one on average in the molecule; Phase-emulsification and cross-linking using a compound having the following formula to obtain spherical toner particles, and the binder resin in the toner particles is 10 to 150 mg (KO).
H) / g carboxyl group acid value and 5,000-20
Weight average molecular weight in the range of 0000, 40-80 ° C
Within a certain range of glass transition temperature, one peak having a weight average molecular weight of 5,000 to 200,000 was obtained from a resin having at least one crosslinkable functional group having an average molecular weight of 2 or more.
It should have at least one peak or shoulder above 00,000, especially above 500,000.

The powdery toner particles thus obtained are, if necessary, externally added with hydrophobic silica or the like, to give a final product.

The spherical toner thus obtained can be used as a powder toner for developing an electrostatic image. A powder toner mainly containing magnetic powder as a colorant is used as it is as a magnetic one-component powder toner for developing an electrostatic image, and a powder toner containing only a colorant other than magnetic powder or mainly containing it is It can be used as a non-magnetic one-component type powder toner for developing a charge image, or can be used as a two-component type developer for developing an electrostatic image by combining a carrier and each of these powder toners.

The plate making method according to the present invention uses a direct-drawing lithographic printing plate precursor having an image receiving layer provided on a water-resistant support,
An electrostatic image formed by an electrophotographic copier or printer is developed with a spherical toner manufactured by the phase inversion emulsification method according to the present invention, and the toner image is transferred to a direct-drawing lithographic printing original plate and then fixed. This is done by: Further, the prepared printing plate is subjected to surface treatment with a desensitizing solution to desensitize the non-image portion, and then mounted on a printing machine, and printing is performed on paper while supplying ink and dampening water. . At this time, after the printing plate is mounted on the printing press, it may be desensitized on the printing press.

The direct-lithographic lithographic printing plate precursor used in the plate making method according to the present invention comprises an image-receiving layer provided on a water-resistant support. As the water-resistant support, a plastic film and a water-resistant treatment are used. Paper, plastic laminated with metal foil, or the like can be used. Also,
A void-containing polyester film obtained by mixing a polyester and a thermoplastic resin incompatible with the polyester as a support and stretching the obtained sheet-like material at least uniaxially can also be used. Further, an intermediate layer may be provided between the support and the image receiving layer for the purpose of improving water resistance and adhesion, and a back coat layer may be provided on the surface of the support opposite to the image receiving layer for the purpose of preventing curling.

The image-receiving layer is generally composed of an inorganic pigment, a water-soluble binder, a water-proofing agent, etc., but a direct-drawing type in which the image-receiving layer is provided on a water-resistant support usable in the plate-making method of the present invention. Examples of the lithographic printing original plate include, for example, JP-A-05-270159, JP-A-05-294083,
-48057, 06-72058 and 06-7998
1, 06-191174, 07-1847, 07
-134711, 07-140731, 07-14
9071, 07-168399, 08-8713
8, 08-104068, 08-106183, 08-183265, 08-230345, 08-
234505, 08-267946, 08-267
947, 08-276679, 08-276680
And the like.

To perform the desensitizing treatment of the printing plate prepared by the plate making method according to the present invention, a known desensitizing solution can be used. For example, when the inorganic pigment of the image receiving layer is zinc oxide, a ferrocyanide salt, a treatment solution containing a cyanide compound containing a ferricyanide as a main component, an ammine cobalt complex, phytic acid and a derivative thereof, and a guanidine derivative as a main component For example, a cyan-free processing solution, a processing solution containing an inorganic acid or an organic acid that forms a chelate with zinc ions as a main component, or a processing solution containing a water-soluble polymer can be used.

[0118]

EXAMPLES Next, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

[Example 1 of Production of Toner] An example of production of a spherical toner in which colored spherical fine particles granulated by a phase inversion emulsification method are heated to crosslink the inside of the particles will be described. <Step 1: Synthesis Example of Aromatic Vinyl Copolymer Having Carboxyl Group> 430 of methyl ethyl ketone was placed in a 3 liter flask equipped with a vinyl monomer dropping device, a thermometer, a nitrogen gas inlet tube, a stirring device, and a reflux condenser. Then, a mixed solution composed of the following polymerizable monomer and polymerization initiator was added dropwise at 80 ° C. over 3 hours.

Styrene 662 parts n-butyl acrylate 248 parts Acrylic acid 90 parts “Perbutyl O” * 4 parts * Radical polymerization initiator manufactured by NOF Corporation; Ter
t-butyl peroxy-2-ethyl hexanate

Next, three hours after the completion of the dropping, 6
After 1 hour and 9 hours, 1
Parts after 12 hours, 15 hours and 18 hours.
After an hour, 2 parts of "perbutyl O" were each added. Nine hours after the completion of dropping, methyl ethyl ketone 5
70 parts were added. Finally, after adding 1 part of “perbutyl O”, the reaction was further continued at 80 ° C. for 3 hours to complete the reaction. Thereafter, a resin solution was obtained by adjusting the nonvolatile content to 50% with methyl ethyl ketone.

The resin thus prepared has an acid value of 7
0, the weight average molecular weight was 80,000, and the glass transition temperature was 64 ° C. At this time, the acid value is the mg amount of KOH required to neutralize 1 g of the resin solids, the weight average molecular weight is a value measured by gel permeation chromatography, and the glass transition temperature is a value measured by DSC.

<Step 2: produced by a phase inversion emulsification method,
Manufacturing method of powder toner in which particles are crosslinked by heating after granulation> 900 parts of resin solution prepared by the above method and "ELFTEX 8" (carbon black manufactured by Cabot Corporation, USA) Was kneaded for 1 hour using "Eiger motor mill M-250" (a pigment dispersing machine of Eiger Japan Co., Ltd.).
Then, the non-volatile content was adjusted to 50% with methyl ethyl ketone to prepare a mill base. The ratio of resin solids / pigment on this mill base is 90/10.

Next, with respect to 200 parts of the mill base, 24 parts of isopropanol, 13.5 parts of a 1N aqueous sodium hydroxide solution (to an extent to neutralize 12% of carboxyl groups) and "as a crosslinking agent" TETRAD-
X "(N, N, N ', manufactured by Mitsubishi Gas Chemical Industry Co., Ltd.)
0.45 parts of N'-tetraglycidyl-m-xylenediamine (the amount of the crosslinking agent used was 10% solid resin)
The amount is 0.6 parts by weight with respect to 0 parts by weight, and the ratio of the glycidyl group is about 0.05 equivalent per 1 equivalent of the carboxyl group. ) Was added thereto, and while stirring at 350 rpm using a three-one motor, 80 cc of ion-exchanged water was gradually added dropwise over 10 minutes, followed by phase inversion emulsification to form spherical fine particles. Further, the mixture was maintained for 60 minutes while stirring at 350 rpm, and then 600 parts of ion-exchanged water was added. Hereinafter, through the following post-treatment steps, toner particles having been granulated and heated to crosslink the particles were produced.

The solvent is removed by distillation under reduced pressure. Add 400 cc of ion-exchanged water and, with stirring,
The crosslinking reaction is performed at 0 ° C. for 8 hours. To the cake after filtration, add 500 parts of ion-exchanged water,
The pH is adjusted from 2 to 3 with 1N hydrochloric acid while further stirring. Filter and wash with 500 parts of deionized water. The wet cake after filtration is freeze-dried. R-972 (Nippon Aerosil hydrophobic silica)
1.3% by weight is externally added.

The obtained spherical toner particles have a particle size of 6.2.
μm. Particle size is "Coulter Multisizer"
It is a volume average particle diameter measured using (a particle diameter measuring device manufactured by Nikkaki Co., Ltd.). The practical sphericity of Wardell was 0.96. The insoluble content% is represented by weight% of the insoluble content 24 hours after Soxhlet extraction using tetrahydrofuran, and the produced toner particles were 61%. The glass transition temperature of the toner particles was 67 ° C. as measured using DSC. The binder resin in the toner particles has a weight average molecular weight of 100,000 to 200,000.
, A higher molecular weight than the resin before crosslinking, and it was confirmed that the resin had at least one peak or shoulder at 500,000 or more.

As Comparative Example 1 for producing a toner, a powder toner containing no crosslinking agent was prepared. Step 1 in Example 1
The same operation was carried out until the mill base of step 2 was prepared. Next, when performing phase inversion emulsification, granulation was performed by the same operation as above without adding a crosslinking agent. The post-treatment was carried out by omitting the work of performing a crosslinking reaction at 60 ° C. for 8 hours in the process, lyophilized, and treated with hydrophobic silica R-9
1.3 was added by weight to obtain a spherical toner of Comparative Example 1. The particle diameter was 6.5 μm, the glass transition temperature was 64 ° C., the practical sphericity of Wardell was 0.94, and the insoluble content% by tetrahydrofuran was 0%, that is, the total amount was dissolved.

As Comparative Example 2 for producing a toner, a toner was prepared in which a crosslinking agent was added but toner particles were not heated after granulation. That is, Example 1 of toner production
The operation up to the completion of the phase inversion emulsification is exactly the same, except that the work of performing a cross-linking reaction at 60 ° C. for 8 hours in the post-treatment is omitted in the post-treatment, freeze-dried, and the hydrophobic silica R-972 is removed. The spherical toner of Comparative Example 2 was obtained by externally adding 1.3% by weight. Particle size is 6.6 μm, glass transition temperature 62
C., Wardell's practical sphericity was 0.93, and the insoluble content% by tetrahydrofuran was 0%, that is, the total amount was dissolved.

Example 2 of Toner Production In place of the cross-linking agent “TETRAD-X” in Example 1 of toner production,
BZA: N, N-diglycidylbenzylamine was added in an amount of 1 part by weight based on 100 parts by weight of resin solids (that is, about 0.07 glycidyl groups per equivalent of carboxyl group).
And the operation was exactly the same as in Example 1 of toner production to obtain a spherical toner of Example 2 for toner production. The particle diameter was 6.9 μm, the glass transition temperature was 66 ° C., the practical sphericity of Wardel was 0.95, and the insoluble content in tetrahydrofuran was 68%.

As Comparative Example 3 for producing a toner, the operation is exactly the same as that in Example 2 for producing a toner until the phase inversion emulsification is completed, but the operation of performing a crosslinking reaction at 60 ° C. for 8 hours during the post-treatment is omitted. The resultant was freeze-dried to obtain a spherical toner of Comparative Example 3. The particle diameter was 7.2 μm, the glass transition temperature was 65 ° C., the practical sphericity of Wardell was 0.93, and the insoluble content% by tetrahydrofuran was 0%, that is, the total amount was dissolved.

The spherical toner obtained by the above-described operation was used by disassembling and remodeling "Mita Copier DC-111" (copier made by Mita Kogyo Co., Ltd.) into an image output section and a fixing section. And a test of a fixing start temperature and a hot offset resistance temperature. The evaluation of the fixing start temperature and the hot offset resistance temperature was performed at a maximum of 245 ° C. in increments of 5 ° C.

The fixing start temperature is as follows. First, the imaged paper is fixed at a speed of 130 mm / sec through a heat roll whose surface temperature is controlled, and a cellophane tape is attached to the heat-fixed image. Was applied with a load of 100 g / cm ² and then peeled off, and its ID value was measured. ID value after cellophane tape peeling test is ID before peeling test
The surface temperature of the hot roll at which the value becomes 90% or more was defined as the fixing start temperature.

The imaged paper is passed through a heat roll (silicon oil non-coating type) whose surface temperature is controlled at a speed of 130 mm / sec, and the temperature at which hot offset occurs is called hot offset occurrence temperature. The offset temperature is a temperature immediately before hot offset occurs.
Hot offset refers to a phenomenon in which toner adheres to a heat fixing roll and is re-transferred to the next adhered paper, thereby soiling the paper.

The test results are shown in Table 1 together with the characteristics of each particle.

[0135]

[Table 1]

It is apparent from Table 1 that the spherical toner according to the present invention, in which the particles are crosslinked by heating after granulation, is a powder toner in the case where no crosslinking agent is used or in which the particles are not crosslinked in the particles. It can be seen that this is a good toner having a high hot offset resistance without adversely affecting the fixing start temperature as compared to In addition, all of the toners produced by the phase inversion emulsification method have a practical Wardell sphericity of about 0.9 or more, indicating that the toner has a narrow particle size distribution and a good image resolution.

Example 1 Example 1 of toner production in a toner cartridge of a commercially available laser printer “Epson LP-1700” (manufactured by Seiko Epson Corporation).
Filled with the toner prepared in step 1 and placed on a direct-drawing lithographic printing plate "Kimoplate" (manufactured by Kimoto Co., Ltd.).
1700 "was used to make an image. Also, as a comparative example, an image was similarly formed on a “Kimo plate” using a genuine toner for Epson LP-1700 (by a pulverization method). Table 2 shows the comparison results of the characteristics at this time.

[0138]

[Table 2]

From Table 2, it is clear that the spherical toner according to the present invention is superior in all characteristics as compared with the existing commercially available pulverized toner. When the toner according to the present invention was used, the character No. 5 was clearly visible. In the case of a commercially available pulverized toner, the character No. 5 was slightly blurred although it could be discriminated from the outline of the character.

Next, a printing test was performed using the printing plates of the present invention and the comparative examples. The printing conditions are as follows;
O820L "(manufactured by Tokyo Airlines Co., Ltd.), printing speed: 5000 sheets / hour, printing paper: Jujo Diamond Coat B
4. Ink; Geos-G-Red-S (manufactured by Dainippon Ink and Chemicals), etch solution: "PP Clean" (manufactured by Nikken Kagaku Kenkyusho), fountain solution; PP Clean is diluted 1:50 with water. And the number of prints was 10,000 copies. Table 3 shows the obtained printing characteristics.

[0141]

[Table 3]

In the printing test, the printing plate of the present invention and the printing plate of the comparative example could print up to 10,000 sheets without any problem. However, as is evident from Table 3, halftone dots tend to be thick in a printing plate using a commercially available toner, and in the case of No. 5, the printed matter of the printing plate by the plate making method of the present invention is clear. On the other hand, in the printed matter of the comparative example toner, the characters were blurred, which was impossible. In the case of the comparative example, the evaluation of the printed matter was limited to the 7th character.

[0143]

According to the present invention, granulated by the phase inversion emulsification method,
According to the plate making method of a direct-drawing lithographic printing plate precursor, which uses a spherical toner having a small particle diameter in which the particles are cross-linked by heating after granulation, the printing durability and the resolution are excellent, and the background scum is excellent. A lithographic printing plate from which printed matter can be obtained can be produced.

Continued on the front page (72) Inventor Shoji Okuno 1-28-1 Osakidai, Sakura City, Chiba Prefecture (72) Inventor Hitoshi Takayanagi 4-16-403 Hanamigawa, Hanamigawa-ku, Chiba City, Chiba Prefecture

Claims (6)

[Claims] When a toner image is formed on a surface of an image receiving layer provided on a water-resistant support in a direct-drawing lithographic printing plate precursor by using an electrophotographic copying machine or a printer, a phase inversion emulsification method is used. A plate making method for a direct-drawing lithographic printing plate precursor, comprising using a manufactured spherical toner having a particle diameter of 2 to 13 micrometers. 2. The spherical toner according to claim 1, wherein a resin having at least one crosslinkable functional group having at least two crosslinkable functional groups and a crosslinker of the resin as a resin component and a colorant contained therein. After preparing a liquid medium dispersion liquid, a part of the resin component is crosslinked to form a binder resin, and then the partially crosslinked particles are separated from the liquid medium and dried to produce a resin. The method of making a direct-drawing lithographic printing original plate according to claim 1. 3. The liquid medium dispersion of particles according to claim 2,
A resin (A) having a functional group that increases hydrophilicity by neutralization and at least two crosslinkable functional groups on average per molecule and capable of being made water-dispersible by neutralization, and a crosslinking agent (B) for the resin (A) ), A colorant (C), an organic solvent (D), and a neutralizing agent (E) sufficient to make the resin (A) water-dispersible. A resin having at least one crosslinkable functional group having an average molecular weight of 2 or more and a crosslinker of the resin as a resin component, which is an aqueous medium dispersion of particles in which a colorant is dispersed, Claim 1
Or the plate making method of the direct-drawing lithographic printing original plate as described in 2 above. 4. The cross-linking agent (B) according to claim 3, wherein the functional group that increases hydrophilicity by neutralization in the resin (A) and at least two cross-linkable functional groups having an average of at least one molecule are carboxyl groups. Is a compound having at least two glycidyl groups per molecule on average. 5. The resin according to claim 4, wherein the resin (A) having a carboxyl group has an acid value of 10 to 150 mg (KOH) / g, a weight average molecular weight of 5,000 to 200,000, And a vinyl copolymer having a glass transition temperature in the range of 40 to 80 ° C. and having a glycidyl group in the range of 0.001 to 0.5 equivalent per 1 equivalent of the carboxyl group of the resin (A). The particle size produced by the phase inversion emulsification method using the crosslinking agent (B) is 3 to 8
The plate making method of a direct-drawing lithographic printing plate precursor according to any one of claims 1 to 4, wherein a spherical toner having a micrometer is used. 6. The binder resin according to claim 2, wherein the content of the insoluble component in tetrahydrofuran is 0.5 to 70.
The direct drawing type lithographic printing plate precursor according to claim 1 or 2, wherein a resin having at least one crosslinkable functional group having an average molecular weight of 2 or more is crosslinked with a crosslinking agent until the amount becomes 1% by weight. Plate making method.