JP5211440B2 - Emulsion ink for ink jet and method for producing the same, ink jet recording method and recorded matter - Google Patents

Description

  The present invention relates to an emulsion ink suitable for inkjet recording and a method for producing the same. Furthermore, the present invention relates to an ink jet recording method and recorded matter using the emulsion ink.

  The ink jet recording method is a printing method in which printing is performed by causing ink droplets to fly and adhere to a recording medium such as paper. As the ink, generally, various water-soluble dyes dissolved in water or water and a water-soluble organic solvent are used. An image formed with an ink containing such a water-soluble dye may be inferior in water resistance or light resistance.

  On the other hand, an ink obtained by dispersing a pigment in an aqueous medium is excellent in water resistance and light resistance. For example, Patent Document 1 proposes an aqueous pigment ink in which carbon black is dispersed with a surfactant or a polymer dispersant. However, with this ink, if the ink content of the colorant is increased in order to increase the print density of the recorded matter, the ink viscosity may increase abruptly with this. In addition, in order to stably disperse carbon black in the ink, an excessive surfactant or polymer dispersant is required, which may cause deterioration of printing stability due to generation of bubbles or deterioration of defoaming property. It was.

In order to improve the fixability of the colorant to the recording medium, proposals have been made to add a resin to the ink composition. This resin is considered to firmly fix the colorant on the recording medium as a binder.
As an ink composition containing a resin, for example, Patent Document 2 discloses an ink in which a pigment and a resin emulsion are dispersed in water, and Patent Document 3 discloses that a pigment is dispersed in a water-insoluble emulsion dispersion. No. 4 uses an emulsion having a specific film-forming temperature, and Patent Document 5 similarly discloses an ink using a resin emulsion. Patent Document 6 proposes an aqueous dispersion pigment ink using a polymer dispersant and a water-soluble organic solvent.
Further, Patent Document 7 proposes an ink for the purpose of securing fixability by adding a resin emulsion. However, in order to improve the ejection stability of the ink, it is necessary to use a resin emulsion having a particle diameter as small as 50 nm or less. For this reason, the emulsion particles have penetrated deeply into the recording medium, and the image quality and the film strength are not satisfactory, which is not satisfactory.

Japanese Patent Application Laid-Open No. H10-228688 proposes printing by attaching a reaction liquid containing a polyvalent metal salt or polyallylamine to a recording medium, and an ink composition containing a pigment and a resin emulsion. However, there is a problem that it is necessary to heat the image after printing in order to improve the scratch resistance, and further, the hand is stained immediately after printing because the drying property of the ink is slow.
Japanese Patent Application Laid-Open No. 2003-228867 proposes that printing is performed by using ink containing a thermoplastic resin component in the ink and ejecting ink droplets onto a recording medium heated above the softening point of the thermoplastic resin. Heating the recording medium not only complicates the apparatus but also consumes large energy, which is not preferable.

Patent Document 10 proposes a polyester-dispersed ink having an epoxy group. In this method, after printing, the epoxy ring is chemically opened and crosslinked to form a film. However, ink that forms a film by using such a chemical reaction often forms a viscosity during storage of the ink, and a problem remains in storage.
Patent Document 11 proposes an ink jet recording method using two liquids. Epoxy is added to one side, and a component that reacts with epoxy is added to one side and reacted after recording to improve the durability of the image. In this method, there is a problem that the apparatus becomes large and complicated, and the total amount of ink ejected increases, resulting in slow drying.
Patent Document 12 proposes a method in which particles having an opposite charge to the colorant particles are added and landed on a recording medium, and then their movements are restricted by these attractive forces to suppress bleeding. In this case, when the ink is ejected, the ink viscosity is designed to decrease depending on the shearing speed. Therefore, it is necessary to precisely control the attractive force between the particles, and the ink ejection mechanism is also considerably limited. There are drawbacks.
In Patent Document 13, in an ink composition containing at least a colorant and a resin emulsion in an aqueous medium, the colorant is a charged particle, and the resin emulsion has the same polarity as the colorant. An ink composition is disclosed. In the ink composition described in Patent Document 13, only an emulsion polymerization resin is disclosed as a resin, and an ink composition using such a resin has a problem that sufficient fixability cannot be obtained. It was. In addition, the emulsion charge is affected by the ionic functional group contained in the monomer, the initiator segment of the polymerization initiator, the ionic surfactant, and the like, and it is difficult to control stably. .
In this way, in an inkjet ink system using a colorant, it is excellent in ejection stability and adhesion to a recording material without causing a system such as an increase in the size of a fixing device or excessive thermal energy. Emulsion inks were not known. Moreover, the composition of the emulsion ink excellent in image quality and water resistance is not known.

JP-A 64-31881 Japanese Examined Patent Publication No. 62-1426 JP 55-157668 A Japanese Patent Laid-Open No. 1-217088 JP-A-4-18462 Japanese Patent Publication No. 4-5703 JP-A-4-18462 JP-A-4-18462 JP-A-10-152640 JP 2003-313468 A Japanese Patent Laid-Open No. 11-10856 Japanese Patent Laid-Open No. 10-168368 JP 2000-351931 A

  In the ink jet recording method using emulsion ink, the present invention provides (1) a high freshness image having excellent ejection stability and adhesion to a recording material, and excellent storage stability (water resistance, weather resistance, etc.). It is an object of the present invention to provide an inkjet emulsion ink and a method for producing the same. (2) It is another object of the present invention to provide an ink jet recording method for forming a good image using the emulsion ink and a recorded matter obtained thereby.

The present invention has been solved by means described in the following <1> to <4>.
<1> Ink-jet emulsion ink containing resin particles containing a polycondensation resin obtained by polycondensation of at least one selected from the group consisting of polycondensable monomers, oligomers thereof and prepolymers, and a colorant. An emulsion ink for inkjet, wherein the resin particles and the colorant have the same polarity charge,
<2> The method according to <1>, including a step of polycondensing at least one selected from the group consisting of a polycondensable monomer, an oligomer thereof and a prepolymer in an aqueous medium to obtain a resin emulsion. A method for producing an emulsion ink for inkjet,
<3> In an ink jet recording method for performing printing by ejecting ink droplets from a recording head and attaching the droplets to a recording medium, the emulsion ink according to <1> is used as the ink Recording method,
<4> A recorded matter obtained by the recording method according to <3>.

  According to the present invention, in an ink jet recording system using emulsion ink, (1) a high freshness image having excellent ejection stability and adhesion to a recording material, and excellent storage stability (water resistance, weather resistance, etc.). Can be provided, and a method for producing the same. (2) It is also possible to provide an ink jet recording method for forming an image using the emulsion ink and a recorded matter obtained thereby.

The inkjet emulsion ink of the present invention (in the present invention, also referred to as “emulsion ink” or simply “ink”) comprises at least one selected from the group consisting of polycondensable monomers, oligomers thereof and prepolymers. An emulsion ink for ink jetting containing resin particles containing a polycondensation resin obtained by polycondensation and a colorant, wherein the resin particles and the colorant have the same polarity of charge. In the present invention, the polycondensable monomers, their oligomers and prepolymers are collectively referred to as polycondensation components. In addition, a resin obtained by polycondensing a polycondensation component is also referred to as a polycondensation resin. As the polycondensable monomer, it is preferable to use two or more types of polycondensable monomers such as polycarboxylic acid and polyol, polycarboxylic acid and polyamine, but self-condensable monomer such as lactic acid. A mer may also be used. In this case, “their oligomers and prepolymers” are meant to include oligomers and prepolymers obtained by polycondensation of one kind of polycondensable monomer.
In the emulsion ink of the present invention, since the resin particles and the colorant are charged with the same polarity, they are kept stable without agglomeration due to electrostatic repulsion, and even if the particle concentration is relatively high, The viscosity does not increase so much, and clogging of the discharge nozzle is remarkably reduced. For this reason, high stability can be ensured as an emulsion ink for inkjet recording. On the other hand, when this emulsion ink adheres to a recording medium such as plain paper, recycled paper, and coated paper, the binder ability of the resin particles binds to a recording medium component such as cellulose and has a strong fixability. Can do.

In the present invention, the emulsion is also referred to as an emulsion, and refers to a mixture in which components that are not mixed in the liquid become fine particles and are dispersed and suspended.
In the emulsion ink of the present invention, a colorant and resin particles are dispersed in an aqueous medium. The aqueous medium will be described later.

In the present invention, examples of the method for producing emulsion inks include the following methods.
Specifically, after polycondensing the [1] (a) polycondensation component (preferably polycondensable monomer) in the presence of a catalyst (preferably a Bronsted acid containing a sulfur atom) as necessary, Examples of the method for producing an emulsion ink include a step of emulsifying by adding a base to obtain a resin emulsion, and a step of (b) adding a colorant (preferably an organic pigment) to prepare an emulsion ink. At this time, the emulsion resin particles and the colorant have charges of the same polarity.
In addition, [2] (a) a polycondensation component (preferably a polycondensable monomer) is mixed with an addition polymerizable monomer such as styrene or acrylate ester (preferably a vinyl monomer) as required. And a method of producing an emulsion ink comprising a step of emulsifying in an aqueous medium and polycondensing to produce a resin emulsion, and (b) a step of producing an emulsion ink by adding a colorant (preferably an organic pigment). . At this time, the emulsion resin particles and the colorant have charges of the same polarity. Here, in the step (a), it is preferable to polycondense the polycondensation component, preferably using sulfur acid (Bronsted acid containing a sulfur atom) as a catalyst. Moreover, it is preferable to polymerize an addition polymerizable monomer, and it is preferable to polymerize an addition polymerizable monomer using a radical polymerization initiator. Further, the polymerization of the addition polymerizable monomer is preferably performed after the polycondensation.
Further, after [3] (a) polycondensation component (preferably polycondensable monomer) is polycondensed in the presence of a catalyst (preferably a Bronsted acid containing a sulfur atom), (b) styrene or An addition polymerizable monomer such as an acrylate ester (preferably a vinyl monomer) is mixed, (c) emulsified in an aqueous medium, and (d) an addition polymerizable monomer using a radical polymerization initiator. Emulsion ink comprising polymerizing a monomer (preferably a vinyl monomer), (e) preparing a resin emulsion, and (f) adding a colorant (preferably an organic pigment) to prepare an emulsion ink The production method can be exemplified. At this time, the emulsion resin particles and the colorant have charges of the same polarity.
Furthermore, in the emulsion ink of the present invention, an addition polymerization resin (preferably a vinyl resin) may be contained in the polycondensation resin particles.

<Colorant>
In the present invention, both a dye and a pigment can be used as the colorant, but a pigment is preferably used.
The pigment as the colorant used in the present invention has a charge in the ink (in the aqueous medium) and can be dispersed in the form of fine particles. The charge may be attributed to the functional group of the pigment itself, or the ionic surface activity. Any of those adsorbing the agent may be used, and there is no particular limitation. However, carbon black having a functional group or an organic pigment is preferably used.
Examples of the pigment include a wide variety of organic and inorganic pigments, and organic pigments are preferred. These can be used alone or in combination. In the present invention, the pigment means a colorant that is insoluble in water or an organic solvent.

The pigment as a raw material used in the present invention preferably has a primary particle diameter of 40 nm or less, more preferably 30 nm or less, and further preferably 30 to 10 nm. A primary particle diameter of 40 nm or less is preferable because the coloring power of the original pigment itself is good and a good optical density (reflection density) of the recorded matter is obtained.
In the present invention, it is preferable that a certain specific functional group is chemically bonded to the surface of such a raw material pigment so as to have a positive or negative charge in water, and the dispersion is stabilized in the form of fine particles by this charge. .

  Moreover, you may wet-oxidize in water using hypohalous acid and / or its salt. Specific examples of hypohalous acid and / or a salt thereof include sodium hypochlorite and potassium hypochlorite, and sodium hypochlorite is particularly preferable from the viewpoint of reactivity. In the oxidation reaction, carbon black and hypohalite (for example, sodium hypochlorite) are charged in an appropriate amount of water, preferably 5 hours or more, more preferably about 10 to 15 hours, and preferably 50 ° C. or more. More preferably, it is carried out by stirring at 95 to 105 ° C. At that time, the pigment is preferably oxidized in a finely dispersed state.

  The average particle size of the pigment dispersed in the aqueous medium in the emulsion ink of the present invention is preferably 50 to 200 nm, and more preferably 75 to 150 nm. It is preferable that the average particle diameter of the pigment dispersed in the emulsion ink is 50 nm or more because a sufficient optical density can be obtained in a recorded matter using the pigment. Moreover, since it is hard to produce pigment sedimentation that it is 200 nm or less, it is preferable.

  The dispersion of the colorant in the aqueous medium is generally carried out by wet pulverization in the aqueous medium for 3 to 10 hours using a mill medium and a pulverizer. As the mill medium, glass beads, zirconia beads, magnetic beads and the like can be used. Examples of the pulverizer include a ball mill, an attritor, a furo jet mixer, an impeller mill, a colloidal mill, and a sand mill (for example, a bead mill, a sand glider, a super mill, an agitator mill, and a dyno mill (trade name)).

  The pigment that is preferably used in the present invention can be obtained, for example, by the method described in JP-A-8-3498. Commercially available products may be used as the pigment, and preferred examples include CAB-O-JET200, 300, IJX-181, 157, 164 manufactured by Cabot Specialty Chemicals Inc. Examples include Microjet CW1 or 2 manufactured by the company.

  In the present invention, a color pigment can also be used as the pigment. Examples of color pigments include CIPigment Yellow 1, CIPigment Yellow 2, CIPigment Yellow 3, CIPigment Yellow 13, CIPigment Yellow 16, CIPigment Yellow 83, and magenta ink. As pigments used, CIPigment Red 5, CIPigment Red 7, CIPigment Red 12, CIPigment Red 48 (Ca), CIPigment Red 48 (Mn), CIPigment Red 57 (Ca), CIPigment Red 112 , CIPigment Red 122, CIPigment Blue 1, CIPigment Blue 2, CIPigment Blue 3, CIPigment Blue 15: 3, CIPigment Blue 16, CIPigment Blue 22, CIVat Blue 4, CIVat Blue 6 and the like.

<Resin emulsion>
In the present invention, the resin particles are preferably resin particles that can be dispersed in water in the form of an aqueous emulsion. As used herein, “resin particles that can be dispersed in water in the form of an aqueous emulsion” refers to a form in which a substantially water-insoluble resin is dispersed in the form of fine particles in water, and is generally an emulsion, dispersion, latex, or suspension. Including what is called. A resin particle dispersion in which resin particles are dispersed in an aqueous medium is also referred to as a resin emulsion or a resin particle emulsion.
In the present invention, the resin particles include a resin (polycondensation resin) obtained by polycondensation of at least one selected from the group consisting of polycondensable monomers, oligomers and prepolymers thereof. The polycondensation resin is preferably a thermoplastic resin. The polycondensation resin is preferably solid at normal temperature.
The resin particles have the same polarity as the colorant.

  In the present invention, polycondensation refers to a reaction in which a polymer compound is produced while performing a condensation reaction, and a condensation reaction refers to a reaction in which two or more parts of two or more molecules sequentially form new bonds. Is a broad term. In general, it refers to a reaction that separates atoms or atomic groups to form a new bond, but in the present invention, it is not limited to this and means a reaction that proceeds sequentially. That is, in the present invention, polycondensation means the meaning of excluding addition polymerization between unsaturated double bonds and / or triple bonds, and chain polymerization reactions such as ring-opening polymerization. Therefore, not only polyester obtained by reaction of polycarboxylic acid and polyol, but polyamide obtained by reaction of polycarboxylic acid and polyamine, polyurethane obtained by reaction of polyisocyanate and polyol, reaction of polyamine and polyisocyanate It includes polyurea obtained by the above, polycarbonate containing phosgene and / or polycarbonate obtained by reaction of a carbonate polymer (for example, aromatic ester such as diphenyl carbonate).

  In the present invention, examples of the polycondensation resin obtained by polycondensation of the polycondensation component include polyesters, polyamides, polyurethanes, polyureas, and polycarbonates. Among these, polyesters and polyamides are preferable, and polyesters are particularly preferable.

In the present invention, the resin emulsion is obtained by dispersing resin particles containing a polycondensation resin in an aqueous medium.
In the present invention, the polycondensation resin is obtained by polycondensation of at least one selected from the group consisting of polycondensable monomers, oligomers and prepolymers, and among these, polycondensable monomers are used. It is preferable to do.
Examples of the polycondensable monomer used for polycondensation include polycarboxylic acids, polyols, and polyamines. As the polycondensation resin, for example, polyester, polyamide and the like can be preferably exemplified, and in particular, a polyester obtained by using a polycarboxylic acid and a polyol as a polycondensable monomer is preferable. . Among these, in the present invention, it is preferable to use a polycondensable monomer as the polycondensation component, particularly to use a dicarboxylic acid as the polyvalent carboxylic acid, and to use a diol as the polyol.
In the present invention, the polycarboxylic acid includes aliphatic, alicyclic and aromatic polycarboxylic acids and alkyl esters thereof, and the polyol includes polyhydric alcohols, ester compounds thereof, hydroxycarboxylic acids and the like. The polyester resin and the polyamide resin can be produced by polycondensation by direct esterification reaction, transesterification reaction or the like using a polycondensable monomer. In this case, the polyester resin to be polymerized may take any form such as amorphous (amorphous / amorphous) polyester, crystalline polyester, or a mixed form thereof.

  In particular, in the present invention, the polycondensation resin preferably contains at least an amorphous polyester having a glass transition point (Tg) of 30 ° C. to 100 ° C., and at least an amorphous polyester having a Tg of 50 ° C. to 80 ° C. It is more preferable to contain. The amorphous polyester having a Tg of 30 ° C. to 100 ° C. is preferably contained in an amount of 5.0% by weight or more, more preferably 10.0 to 90.0% by weight based on the entire resin particles.

  The polycarboxylic acid used as a monomer used for polycondensation is a compound containing two or more carboxyl groups in one molecule. Among these, a divalent carboxylic acid is a compound containing two carboxyl groups in one molecule. For example, oxalic acid, succinic acid, maleic acid, adipic acid, glutaric acid, β-methyladipic acid, azelaic acid, Sebacic acid, suberic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, fumaric acid, citraconic acid, diglycolic acid, glutaconic acid, n-dodecylsuccinic acid, n-dodecenylsuccinic acid, isododecylsuccinic acid , Isododecenyl succinic acid, n-octyl succinic acid, cyclohexane dicarboxylic acid, cyclohexane-3,5-diene-1,2-dicarboxylic acid, malic acid, citric acid, hexahydroterephthalic acid, malonic acid, pimelic acid , Tartaric acid, mucous acid, phthalic acid, isophthalic acid, terephthalic acid, Lachlorophthalic acid, chlorophthalic acid, nitrophthalic acid, p-carboxyphenylacetic acid, p-phenylenediacetic acid, m-phenylenediglycolic acid, p-phenylenediglycolic acid, o-phenylenediglycolic acid, diphenylacetic acid, diphenyl-p, p Examples include '-dicarboxylic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, anthracene dicarboxylic acid, and the like. Examples of the polyvalent carboxylic acid other than the divalent carboxylic acid include trimellitic acid, pyromellitic acid, naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid, pyrenetricarboxylic acid, and pyrenetetracarboxylic acid. Furthermore, these lower ester etc. are mentioned. Furthermore, the acid chloride is not limited to this. These may be used alone or in combination of two or more. Furthermore, in addition to the aliphatic dicarboxylic acid and aromatic dicarboxylic acid described above, a dicarboxylic acid component having a double bond can also be contained.

  In the method for producing a polyester in the present invention, among the above polyvalent carboxylic acids, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decamethylenedicarboxylic acid, 1,11-undecanedicarboxylic acid, It is preferable to use 1,12-dodecanedicarboxylic acid, terephthalic acid, trimellitic acid, pyromellitic acid or the like. Since these polyvalent carboxylic acids are hardly soluble or insoluble in water, the ester synthesis reaction proceeds in a suspension in which the polyvalent carboxylic acid is dispersed in water, which is preferable.

  The polyol as a monomer in the production method of the present invention is a compound containing two or more hydroxyl groups in one molecule. Among these, a divalent polyol is a compound containing two hydroxyl groups in one molecule. For example, ethylene glycol, propylene glycol, butanediol, butenediol, neopentylglycol, pentanediol, hexanediol, cyclohexanediol, cyclohexane Dimethanol, diethylene glycol, triethylene glycol, dipropylene glycol, octanediol, nonanediol, decanediol, dodecanediol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, bisphenol Z, hydrogenated bisphenol A, etc. Can do. Examples of polyols other than divalent polyols include glycerin, pentaerythritol, hexamethylol melamine, hexaethylol melamine, tetramethylol benzoguanamine, and tetraethylol benzoguanamine. These may be used alone or in combination of two or more.

In the method for producing a polyester of the present invention, among the above-mentioned polyols, it is preferable to use a divalent polyol such as 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol.
Since these polyols are hardly soluble or insoluble in water, the ester synthesis reaction proceeds in a suspension in which the polyol is dispersed in water, which is preferable.

Also, a polyamine and a polyol can be used as the polycondensable monomer, and a similar resin particle dispersion can be produced using polyamide.
Polyamines used to obtain polyamides include ethylenediamine, diethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 1,4-butanediamine, 1,4-butenediamine, 2,2-dimethyl. -1,3-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,4-cyclohexanediamine, 1,4-cyclohexanebis (methylamine) and the like can be mentioned.

In addition, an amorphous resin or a crystalline resin can be easily obtained by a combination of these polycondensable monomers.
As the polyvalent carboxylic acid used to obtain the crystalline polyester, among the above carboxylic acids, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, Aliphatic dicarboxylic acids such as 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, sebacic acid, malee Acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, n-dodecyl succinic acid, n-dodecenyl succinic acid, isododecyl succinic acid, isododecenyl succinic acid, n-octyl succinic acid, n-octenyl succinic acid, these An acid anhydride, a lower ester, or an acid chloride can be mentioned. Moreover, the polyvalent carboxylic acid more than bivalence mentioned later can also be used together.

Examples of the diol used to obtain the crystalline polyester include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, and 1,4-butenediol. Neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11 -Undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,14-eicosandecanediol, diethylene glycol, triethylene glycol, dipropylene Glycol Polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, bisphenol Z, bisphenol C Bisphenol E, bisphenol F, bisphenol P, bisphenol S, bisphenol Z, biphenol, naphthalene diol, adamantanediol, adamantane dimethanol, hydrogenated bisphenol A and the like can also be mentioned. A dihydric or higher polyhydric alcohol can also be used in combination. Examples thereof include glycol, pentaerythritol, hexamethylol melamine, hexaethylol melamine, tetramethylol benzoguanamine, and tetraethylol benzoguanamine.
The bisphenols preferably have at least one alkylene oxide group. Examples of the alkylene oxide group include, but are not limited to, an ethylene oxide group, a propylene oxide group, and butylene oxide. Preferably, they are ethylene oxide and propylene oxide, and the added mole number is preferably 1 to 3. When it is within this range, the viscoelasticity and glass transition temperature of the produced polyester can be appropriately controlled for use as a toner.

  Examples of such a crystalline polycondensation resin include polyesters obtained by reacting 1,9-nonanediol and 1,10-decanedicarboxylic acid, or cyclohexanediol and adipic acid, and 1,9-nonanediol and sebacin. Polyester obtained by reacting acid, polyester obtained by reacting 1,6-hexanediol and sebacic acid, polyester obtained by reacting ethylene glycol and succinic acid, reacting ethylene glycol and sebacic acid And polyester obtained by reacting 1,4-butanediol with succinic acid. Among these, polyesters obtained by reacting 1,9-nonanediol and 1,10-decanedicarboxylic acid, 1,9-nonanediol and sebacic acid, and 1,6-hexanediol and sebacic acid are particularly preferred. This is preferable but not limited to this.

In addition, as the polyvalent carboxylic acid used to obtain the non-crystalline polyester in the present invention, among the above polyvalent carboxylic acids, as the dicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrachlorophthalic acid, Chlorphthalic acid, nitrophthalic acid, malonic acid, mesaconic acid, p-carboxyphenylacetic acid, p-phenylene diacetic acid, m-phenylene diglycolic acid, p-phenylene diglycolic acid, o-phenylene diglycolic acid, diphenylacetic acid, diphenyl- p, p'-dicarboxylic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, anthracene dicarboxylic acid, cyclohexanedicarboxylic acid, cyclohexene dicarboxylic acid, norbornene-2 , 3-Dicarboxylic acid, Adama And ntandicarboxylic acid and adamantanediacetic acid. Examples of the polyvalent carboxylic acid other than dicarboxylic acid include trimellitic acid, pyromellitic acid, naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid, pyrenetricarboxylic acid, and pyrenetetracarboxylic acid. Moreover, you may use what derived the carboxyl group of these carboxylic acid into the acid anhydride, the acid chloride, or ester.
Among these, it is preferable to use terephthalic acid, its lower ester, phenylenediacetic acid, cyclohexanedicarboxylic acid and the like. The lower ester refers to an ester of an aliphatic alcohol having 1 to 8 carbon atoms.

The polyol used for obtaining the non-crystalline polyester in the present invention is, among the above-mentioned polyols, in particular, polytetramethylene glycol, bisphenol A, bisphenol Z, bisphenol S, biphenol, naphthalenediol, adamantanediol, adamantane di It is preferable to use methanol, hydrogenated bisphenol A, cyclohexanedimethanol or the like. The bisphenols are also preferably alkylene oxide adducts, particularly ethylene oxide adducts and propylene oxide adducts.
Among these, the polyol used to obtain the amorphous polyester is preferably an alkylene oxide adduct of bisphenol A, and more preferably an ethylene oxide adduct and a propylene oxide adduct of bisphenol A. Further, the alkylene oxide is preferably added in an amount of 2 mol to 4 mol in terms of both terminals, and more preferably 2 mol or 4 mol.
In order to produce one type of polycondensation resin, each of the polyvalent carboxylic acid and polyol may be used alone or in combination of two or more, each of which may be used alone or in combination of two or more. You may use each. Moreover, when using hydroxycarboxylic acid in order to produce 1 type of polycondensation resin, 1 type may be used individually, 2 or more types may be used, and polyvalent carboxylic acid and a polyol may be used together.

  Amorphous polycondensation resin includes a bisphenol A propylene oxide 2 mol adduct (2 mol adduct in terms of both ends), a 4 mol adduct (4 mol adduct in terms of both ends) and dimethyl terephthalate. Condensate, polycondensate of ethylene oxide 2 mol adduct of bisphenol A (2 mol adduct in terms of both ends), 4 mol adduct (4 mol adduct in terms of both ends) and cyclohexanedicarboxylic acid, ethylene of bisphenol A Particularly preferred is a polycondensate of 2 mol addition of oxide or propylene oxide (2 mol adduct in terms of both ends) or 4 mol adduct (4 mol adduct in terms of both ends) and phenylene diacetic acid or phenylene dipropionic acid. .

  In the present invention, when crystalline polyester is used as the polycondensation resin, the crystalline melting point Tm is preferably 50 to 120 ° C, more preferably 55 to 90 ° C. It is preferable that Tm is 50 ° C. or higher because the peelability is improved and the offset can be reduced. Further, it is preferable that Tm is 120 ° C. or lower because fixing can be performed at a lower temperature.

  Here, for the measurement of the melting point of the crystalline polyester resin, a differential scanning calorimeter (DSC) was used, and JIS K-7121: 87 when the measurement was performed at a temperature rising rate of 10 ° C. per minute from room temperature to 150 ° C. The melting peak temperature of the input compensation differential scanning calorimetry shown in FIG. The crystalline polyester resin may show a plurality of melting peaks, but in the present invention, the maximum peak is regarded as the melting point.

On the other hand, when an amorphous polyester resin is used as the polycondensation resin, the glass transition point (Tg) of the amorphous polyester is preferably 30 ° C. or higher, more preferably 30 to 100 ° C., and 50 to 50 ° C. More preferably, it is 80 degreeC. When the glass transition point (Tg) of the polycondensation resin is 30 ° C. or higher, it is in a glass state in use, so that the emulsion does not aggregate due to heat and pressure received during discharge, and does not adhere to and accumulate on the site. This is preferable because it provides an effect that stable ejection can be obtained over a long period of time.
Here, the glass transition point of the non-crystalline resin refers to a value measured by a method (DSC method) defined in ASTM D3418-82.
Moreover, the measurement of the glass transition point in this invention can be measured by "DSC-20" (made by Seiko Electronics Co., Ltd.), for example according to the differential scanning calorimetry (DSC), for example, specifically, about 10 mg of samples. Is heated at a constant rate of temperature increase (10 ° C./min), and a glass transition point can be obtained from the intersection of the baseline and the endothermic peak tilt line.

In the present invention, when a crystalline polyester resin is used as the polycondensation resin, the weight average molecular weight is 1,000 to 60, as measured by the gel permeation chromatography (GPC) method of the tetrahydrofuran (THF) soluble content. 000 is preferred, 1,500 to 50,000 is more preferred, and 2,000 to 40,000 is even more preferred.
Moreover, when using an amorphous polyester resin as a polycondensation resin, it is preferable that the weight average molecular weight is 1,000-60,000 by the molecular weight measurement by GPC method of THF soluble part, and 3,000- It is more preferably 50,000, and further preferably 5,000 to 40,000.
It is preferable that the weight average molecular weight is within the above range since both image strength and fixability can be achieved.
In the present invention, the molecular weight of the resin is measured with a THF solvent using a THF soluble material, such as TSK-GEL, GMH (manufactured by Tosoh Corporation), etc., and a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample is obtained. Can be used to calculate the molecular weight.

  Here, in the present invention, “crystallinity” in “crystalline polyester resin” means that it has a clear endothermic peak, not a step-like endothermic change in differential scanning calorimetry (DSC). Means that the half-value width of the endothermic peak when measured at a heating rate of 10 ° C./min is within 15 ° C. On the other hand, a resin having a half-value width of an endothermic peak exceeding 15 ° C. or a resin in which no clear endothermic peak is observed means non-crystalline (amorphous).

In the present invention, the polycondensation step may include a polymerization reaction between the polycarboxylic acid and polyol, which are the aforementioned polycondensation monomers, and an oligomer and / or prepolymer prepared in advance. The prepolymer is not limited as long as it is a polymer that can be melted or uniformly mixed with the monomer.
Furthermore, in the present invention, the resin particles of the emulsion may be a homopolymer of the above-mentioned polycondensation component, a copolymer combining two or more monomers containing the above-mentioned polycondensation component, or a mixture or graft polymer thereof. Further, it may have a partially branched or cross-linked structure.

In the present invention, the polycondensation resin is obtained by polycondensation of a polycondensation component, preferably a polycondensable monomer, and is particularly preferably a polycondensation resin obtained by polycondensation under a catalyst. In the present invention, it is preferable that sulfur acid (Bronsted acid containing a sulfur atom) is included as a polycondensation catalyst. The polycondensation catalyst will be described below.
<Catalyst>
In this invention, it is preferable to use a sulfuric acid (Bronsted acid containing a sulfur atom) as a polycondensation catalyst.
(Sulfur acid)
Sulfur acid is a Bronsted acid containing a sulfur atom, and examples of the sulfur acid include inorganic sulfur acids and organic sulfur acids. Examples of the inorganic sulfur acid include sulfuric acid, sulfurous acid, and salts thereof, and examples of the organic sulfur acid include sulfonic acids such as alkyl sulfonic acid, aryl sulfonic acid, and salts thereof, alkyl sulfuric acid, Organic sulfuric acids such as aryl sulfuric acid and salts thereof are mentioned.
The sulfur acid is preferably an organic sulfur acid, and more preferably an organic sulfur acid having a surface active effect. The acid having a surface-active effect has a chemical structure composed of a hydrophobic group and a hydrophilic group, has an acid structure in which at least a part of the hydrophilic group is composed of protons, and has both an emulsifying function and a catalytic function. A compound.
Examples of the organic sulfur acid having a surface active effect include alkylbenzene sulfonic acid, alkyl sulfonic acid, alkyl disulfonic acid, alkyl phenol sulfonic acid, alkyl naphthalene sulfonic acid, alkyl tetralin sulfonic acid, alkyl allyl sulfonic acid, petroleum sulfonic acid, alkyl benzoic acid. Imidazole sulfonic acid, higher alcohol ether sulfonic acid, alkyl diphenyl sulfonic acid, long chain alkyl sulfate, higher alcohol sulfate, higher alcohol ether sulfate, higher fatty acid amide alkylol sulfate, higher fatty acid amide alkylated sulfate, sulfate Fat, sulfosuccinic acid ester, resin acid alcohol sulfuric acid, and all salt compounds thereof may be mentioned, and a plurality of them may be combined as necessary. Among these, a sulfonic acid having an alkyl group or an aralkyl group, a sulfate ester having an alkyl group or an aralkyl group, or a salt compound thereof is preferable, and the alkyl group or the aralkyl group has 7 to 20 carbon atoms. More preferably. Specifically, dodecylbenzenesulfonic acid, pentadecylbenzenesulfonic acid, isopropylbenzenesulfonic acid, camphor sulfonic acid, p-toluenesulfonic acid, monobutylphenylphenol sulfate, dibutylphenylphenol sulfate, dodecyl sulfate, naphthenyl alcohol Examples include sulfuric acid. These sulfur acids may have some functional group in the structure.

It is preferable that the usage-amount of the sulfur acid (sulfur acid containing a sulfur atom) which can be used for this invention is 0.05-20 weight% with respect to the total weight of a polycondensation component, 0.1-10 weight % Is more preferable.
It is preferable for the amount of sulfur acid used to be within the above range since sufficient catalytic activity can be exhibited. In particular, by adding it to the aqueous medium together with the polycondensation component, the stability of the particles is maintained, the polycondensation reaction is further increased, and the polycondensation reaction is performed at a low temperature (preferably 150 ° C. or less, more preferably 130 ° C. or less And more preferably 100 ° C. or lower).

Other polycondensation catalysts generally used can be used together with the above-mentioned sulfur acid catalyst or alone. Specifically, an acid having a surface active effect, a metal catalyst, a hydrolase type catalyst, and a basic catalyst can be exemplified.
(Acid having surface-active effect)
Examples of the acid having a surface active effect include various fatty acids, higher alkyl phosphate esters, resin acids, and all salt compounds thereof, and a plurality of them may be combined as necessary.

(Metal catalyst)
Examples of the metal catalyst include, but are not limited to, the following. Examples thereof include organic tin compounds, organic titanium compounds, organic antimony compounds, organic beryllium compounds, organic strontium compounds, organic germanium compounds, organic tin halide compounds, and rare earth-containing catalysts.
Specific examples of the rare earth-containing catalyst include scandium (Sc), yttrium (Y), and lanthanoid elements such as lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), and europium. (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), etc. are effective. is there. Of these, alkylbenzene sulfonates, alkyl sulfate esters, and those having a triflate structure are particularly effective. Examples of the triflate include X (OSO ₂ CF ₃ ) _{3 in} the structural formula. Here, X is a rare earth element, and among these, X is preferably scandium (Sc), yttrium (Y), ytterbium (Yb), samarium (Sm), or the like.
The lanthanoid triflate is described in detail in Journal of Synthetic Organic Chemistry, Vol. 53, No. 5, p44-54.

When using a metal catalyst as a catalyst, it is preferable to make the metal content derived from the catalyst in the resin obtained into 10 ppm or less. More preferably, it is 7.5 ppm or less, and further preferably 5.0 ppm or less. Therefore, it is preferable not to use a metal catalyst or to use a very small amount even when a metal catalyst is used.
Setting the metal content in the resin to 10 ppm or less is preferable because the stability of the resin particles in the emulsion ink is improved.

(Hydrolytic enzyme type catalyst)
The hydrolase type catalyst is not particularly limited as long as it catalyzes an ester synthesis reaction. Examples of the hydrolase in the present invention include EC (enzyme number) 3.1 group such as carboxyesterase, lipase, phospholipase, acetylesterase, pectinesterase, cholesterol esterase, tannase, monoacylglycerol lipase, lactonase, lipoprotein lipase and the like. (See Maruo and Tamiya's "Enzyme Handbook" Asakura Shoten, (1982), etc.) Hydrolase enzymes classified into EC 3.2 group that act on glycosyl compounds such as esterases, glucosidases, galactosidases, glucuronidases, xylosidases ECs that act on peptide bonds such as hydrolase, aminopeptidase, chymotrypsin, trypsin, plasmin, subtilisin, etc. classified into EC 3.3 group such as epoxide hydrase Hydrolase classified .4 group, mention may be made of hydrolytic enzymes such as classified into EC3.7 group such as furo retinoic hydrolase.
Among the above esterases, enzymes that hydrolyze glycerol esters to liberate fatty acids are called lipases, but lipases are highly stable in organic solvents, catalyze ester synthesis reactions in high yields, and are available at a lower price. There are advantages such as what you can do. Therefore, in the present invention, it is desirable to use lipase from the viewpoint of yield and cost.
Lipases of various origins can be used, but preferred are Pseudomonas genus, Alcaligenes genus, Achromobacter genus, Candida genus, Aspergillus genus, Rhizopus Examples include lipases obtained from microorganisms such as (Rhizopus) genus and Mucor genus, lipases obtained from plant seeds, lipases obtained from animal tissues, pancreatin, steapsin and the like. Among these, it is desirable to use lipases derived from microorganisms of the genus Pseudomonas, Candida, and Aspergillus.

(Basic catalyst)
Examples of the basic catalyst include, but are not limited to, general organic basic compounds, nitrogen-containing basic compounds, and tetraalkyl or arylphosphonium hydroxides such as tetrabutylphosphonium hydroxide. Examples of the organic base compound include ammonium hydroxides such as tetramethylammonium hydroxide and tetraethylammonium hydroxide, and examples of the nitrogen-containing basic compound include amines such as triethylamine and dibenzylmethylamine, pyridine, methylpyridine, methoxypyridine, Quinolin, imidazole, alkali metals such as sodium, potassium, lithium, cesium, and alkaline earth metals such as calcium, magnesium, barium, hydroxides, hydrides, amides, alkalis, alkaline earth metals and acids And salts with carbonates, phosphates, borates, carboxylates and phenolic hydroxyl groups.
Moreover, a compound with an alcoholic hydroxyl group, a chelate compound with acetylacetone, and the like can be exemplified, but the invention is not limited thereto.

The total amount of catalyst added is preferably 0.05 to 20% by weight, more preferably 0.1 to 10% by weight, based on the polycondensation component. One or a plurality of them can be added in the above ratio.
It is preferable that the total addition amount of the catalyst is within the above range because the polycondensation reactivity is sufficiently high, while reverse reaction and side reaction can be suppressed.

<Polycondensation reaction>
Next, the polycondensation reaction will be described.
In the present invention, it is preferable to obtain a polycondensation resin by polycondensation reaction at a temperature lower than the conventional reaction temperature, and the reaction temperature is preferably 70 ° C. or higher and 150 ° C. or lower. More preferably, it is 75 degreeC or more and 130 degrees C or less, Most preferably, it is 80-100 degreeC.
When the reaction temperature is 70 ° C. or higher, the reactivity of the polycondensation component, preferably the polycondensable monomer, is not reduced due to the decrease in the catalytic activity and the increase in the molecular weight is suppressed. This is preferable because there is not. Moreover, since it can manufacture with low energy as reaction temperature is 150 degrees C or less, it is preferable. Further, it is preferable because coloring of the obtained resin and decomposition of the produced polycondensation resin do not occur.

Producing polycondensation resin at a low temperature of 150 ° C or less while avoiding the conventional high energy consumption type manufacturing method is extremely important to reduce the resin production energy and emulsion ink production energy in a total sense. It is. Conventionally, a polycondensation reaction has been performed at a high temperature exceeding 200 ° C., but in order to perform polymerization at a low temperature of 150 ° C. or lower which is several tens of degrees Celsius to several tens of degrees Celsius below, a sulfur acid catalyst is used. Is preferred. This is because conventional metal catalysts such as Sn-based and Ti-based metals exhibit high catalytic activity especially at 200 ° C. or higher, and very low activity at low temperatures of 150 ° C. or lower.
Sulfuric acid has a catalytic activity that decreases with increasing temperature at temperatures higher than 160 ° C. However, since the reaction proceeds with the nucleophilic addition of the catalytic acid, the polymerization temperature is about 70 ° C to about 70 ° C. Since the catalyst activity is high in a low temperature range of 150 ° C. and can be suitably used for a polycondensation reaction at 150 ° C. or less, it can be suitably used as a polycondensation catalyst in the present invention.

  This polycondensation reaction can be carried out by a general polycondensation method such as bulk polymerization, emulsion polymerization, suspension polymerization, or other underwater polymerization, solution polymerization, interfacial polymerization, etc., but bulk polymerization and underwater polymerization are preferably used. . Among these, it is preferable to obtain a polycondensation resin by directly polycondensing a polycondensable monomer in an aqueous medium.

(Bulk polymerization)
In the case of bulk polymerization, the reaction is possible under atmospheric pressure, but general conditions such as reduced pressure and nitrogen flow can be used for the purpose of increasing the molecular weight of the resulting polycondensation resin.
A polycondensable monomer is preferably used as the polycondensation component, polycarboxylic acid and polyol are preferably used as the polycondensable monomer, and dicarboxylic acid and diol are particularly preferably used. Moreover, it is preferable to use a sulfur acid (Bronsted acid containing a sulfur atom) as a catalyst, and it is preferable that polycondensation is performed at 150 degrees C or less as mentioned above.
That is, it is preferable to directly polymerize a polycondensable monomer at a low temperature of 150 ° C. or lower using sulfur acid (Bronsted acid containing a sulfur atom) as a catalyst.

A resin particle dispersion can be obtained by emulsifying and dispersing the polycondensation resin obtained as described above in an aqueous medium.
The polycondensation resin is preferably emulsified and dispersed by adding a base (basic compound). The base is preferably added to the aqueous medium. It does not specifically limit as a base, Although a well-known base can be used, Amines and pyridines can be illustrated, Among these, dimethylbenzylamine, dimethylpyridine, and ethanolamine are preferable.
The addition amount of the base can be appropriately selected within a range in which good dispersion in the aqueous medium is performed, but is preferably 0.01 to 20 mol / L, and preferably 0.1 to 2 mol / L. More preferred.

In addition, an addition polymerizable monomer described later, particularly a vinyl monomer such as styrene or acrylate, is added to the obtained polycondensation resin, and this is emulsified and dispersed to initiate a polymerization initiator, particularly radical polymerization. It is also preferable to polymerize the addition polymerizable monomer using an agent. In this case, the polymerization initiator can be added to the mixture containing the polycondensation resin and the addition polymerizable monomer before emulsification and dispersion, but is preferably added to the aqueous medium.
Further, an addition polymerizable monomer may be added to the polycondensation component, polycondensed under a catalyst, emulsified and dispersed in an aqueous medium, and addition polymerization may be performed using a polymerization initiator.
When the resin particles contain an addition polymerization type polymer, a hybrid resin (particles thereof) with a polycondensation resin can be obtained. These addition polymerizable monomers can also be polymerized by adding a new monomer after the polymerization of the polycondensation component.

<In-water polymerization>
Next, an underwater polymerization method performed in an aqueous medium will be described.
In the present invention, the aqueous medium means water or a mixed solvent containing 50% by weight or more of water, and water may be mixed with a water-miscible organic solvent. The mixing ratio of water in the mixed solvent is preferably 60 to 100% by weight, and more preferably 70 to 100% by weight. Examples of the water-miscible organic solvent include ethyl alcohol, methyl alcohol, acetone, and acetic acid, and ethyl alcohol is preferable. The aqueous medium is most preferably water, and soft water or ion exchange water is preferred. These may be used individually by 1 type and may use 2 or more types together.

  In the present invention, the polymerization method in an aqueous medium is not particularly limited, but is usually a suspension polymerization method, a dissolution suspension method, a miniemulsion method, a microemulsion method, a multistage swelling method or an emulsion polymerization method including seed polymerization. It is preferable to use a heterogeneous polymerization form in an aqueous medium. In this case, the polycondensation reaction, particularly the final molecular weight and the polymerization rate depends on the final particle size of the particles, so that the most preferable particle size form of 1 μm can be achieved, and efficient production can be achieved. As a certain production form, a polymerization method in which submicron particles of 1 μm or less such as a miniemulsion method and a microemulsion method are used as the final form is more preferable.

In the present invention, as a polymerization method in an aqueous medium, a polycondensation component (preferably a polycondensable monomer) and, if necessary, a catalyst or the like are added, and this mixture is emulsified and dispersed in an aqueous medium and stirred. A method of advancing the polycondensation reaction by heating while heating can be exemplified, whereby a resin particle dispersion can be obtained. As described above, the heating temperature is preferably 70 ° C. or higher and 150 ° C. or lower.
More specifically, a sulfur acid catalyst (DBSA (dodecylbenzene sulfonic acid), etc.) is added to a polyvalent carboxylic acid and polyol mixture which is a polycondensable monomer, emulsified and dispersed in an aqueous medium, and heated and stirred. An example is a method of realizing a resin dispersion by polycondensation at 150 ° C. or less as much as possible.
It is also preferred that the polycondensation reaction is allowed to proceed to some extent before emulsification and dispersion.

Further, an addition polymerizable monomer (preferably a vinyl monomer) described later is further added to a mixture containing at least a polycondensation component (preferably a polycondensable monomer), and this is emulsified in an aqueous medium. After dispersion and polycondensation, it is also preferable to add a polymerization initiator (preferably a radical polymerization initiator) to obtain a resin particle dispersion obtained by polymerizing an addition polymerizable monomer.
The polymerization initiator can be added to the aqueous medium before polycondensation, for example, at the time of emulsification dispersion, but is preferably added to the aqueous medium after polycondensation.

  When polycondensation components are polycondensed in an aqueous medium, the above materials are emulsified or dispersed in the aqueous medium using, for example, mechanical shear or ultrasonic waves. Thus, it is possible to add a surfactant, a polymer dispersant, an inorganic dispersant, etc. to the aqueous medium.

  Examples of the surfactant used herein include anionic surfactants such as sulfate ester, sulfonate, and phosphate ester; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol And nonionic surfactants such as polyphenols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, anionic surfactants and cationic surfactants are preferable. The nonionic surfactant is preferably used in combination with the anionic surfactant or the cationic surfactant. The said surfactant may be used individually by 1 type, and may use 2 or more types together. As anionic surfactants, sodium dodecylbenzenesulfonate, sodium alkylnaphthalenesulfonate, sodium arylalkylpolyethersulfonate, 3,3-disulfonediphenylurea-4,4-diazo-bis-amino-8-naphthol-6 Sodium sulfonate, ortho-carboxybenzene-azo-dimethylaniline, 2,2,5,5-tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol-6-sodium sulfonate, dialkylsulfosuccinate Sodium sulfate, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium caprate, sodium caprylate, caproic acid Thorium, potassium stearate, and the like calcium oleate. Examples of the cationic surfactant include alkylbenzene dimethyl ammonium chloride, alkyl trimethyl ammonium chloride, distearyl ammonium chloride and the like. Nonionic surfactants include polyethylene oxide, polypropylene oxide, combinations of polypropylene oxide and polyethylene oxide, esters of polyethylene glycol and higher fatty acids, alkylphenol polyethylene oxide, esters of higher fatty acids and polyethylene glycol, higher fatty acids and polypropylene oxide. Examples thereof include esters and sorbitan esters. Examples of the polymer dispersant include sodium polycarboxylate and polyvinyl alcohol, and examples of the inorganic dispersant include calcium carbonate. However, these do not limit the present invention. Further, in order to prevent the Ostwald Ripping phenomenon of the monomer emulsion particles in a normal aqueous medium, a higher alcohol represented by heptanol or octanol or a higher aliphatic hydrocarbon represented by hexadecane is often added as a stabilizer. It is also possible.

In the present invention, as described above, the polycondensation reaction can be performed in the presence of an addition polymerizable monomer, and the addition polymerizable monomer can be mixed after the polycondensation reaction. . Finally, addition polymerization of an addition polymerizable monomer can be performed to give composite particles of a polycondensation resin and an addition polymerization type polymer.
The addition polymerizable monomer that can be used in the present invention includes a radical polymerizable monomer, a cationic polymerizable monomer, or an anion polymerizable monomer, and is a radical polymerizable monomer. It is preferable.

  The addition amount of the addition polymerizable monomer is preferably 1.0 to 50.0 parts by weight with respect to 100 parts by weight of the polycondensation resin or polycondensation component, and 3.0 to 30.0 parts by weight. More preferably. It is preferable that the addition amount of the addition polymerizable monomer is within the above range because an ink excellent in fixing property and particle forming property can be obtained.

  Specific examples of the radical polymerizable monomer include α-substituted styrene such as styrene, α-methylstyrene, α-ethylstyrene, m-methylstyrene, p-methylstyrene, and 2,5-dimethylstyrene. Nuclear aromatic styrene such as p-chlorostyrene, p-bromostyrene, and vinyl aromatics such as halogen-substituted halogenated styrene such as dibromostyrene, (meth) acrylic acid ("(meth) acryl" means acrylic And the same shall apply hereinafter.), Unsaturated carboxylic acids such as crotonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (Meth) acrylate, butyl (meth) acrylate (n-butyl (meth) acrylate, isobutyl (meth) Acrylate, etc.), pentyl (meth) acrylate, hexyl (meth) acrylate, dodecyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, glycidyl (meth) acrylate, benzyl (meth) acrylate, Unsaturated carboxylic acid esters such as 2-chloroethyl (meth) acrylate, phenyl (meth) acrylate and α-chloromethyl (meth) acrylate, unsaturated carboxylic acids such as (meth) acrylaldehyde, (meth) acrylonitrile and (meth) acrylamide Acid derivatives, N-vinyl compounds such as N-vinylpyridine, N-vinylpyrrolidone, vinyl esters such as vinyl formate, vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, vinyl fluoride, vinyl chloride , Vinyl halides such as vinyl bromide and vinylidene chloride, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone N-vinyl compounds such as N-methylol acrylamide, N-ethylol acrylamide, N-propanol acrylamide, N-methylol maleamic acid, N-methylol maleamic acid ester, N-methylol maleimide, N-ethylol maleimide, etc. N-substituted unsaturated amides, conjugated dienes such as butadiene and isoprene, polyfunctional vinyl compounds such as divinylbenzene, divinylnaphthalene and divinylcyclohexane, ethylene glycol di (meth) acrylate , Diethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, tetramethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, hexamethylene glycol di (meth) acrylate, trimethylolpropane di (meth) Acrylate, trimethylolpropane tri (meth) acrylate, glycerol di (meth) acrylate, glycerol tri (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, di Pentaerythritol di (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (me ) Acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, sorbitol tri (meth) acrylate, sorbitol tetra (meth) acrylate, sorbitol penta (meth) acrylate, sorbitol hexa (meth) acrylate, etc. Examples include polyfunctional acrylates. Among these, N-substituted unsaturated amides, conjugated dienes, polyfunctional vinyl compounds, polyfunctional acrylates, and the like can also cause a crosslinking reaction in the produced polymer. These can be used alone or in combination.

In addition, as a polymerization method of the radical polymerizable monomer, a known polymerization method such as a method using a radical polymerization initiator, a heat self-polymerization method, a method using ultraviolet irradiation, or the like can be employed. In this case, as a method using a radical polymerization initiator, radical polymerization initiators include oil-soluble and water-soluble ones, but both initiators can be used.
As the radical polymerization initiator, a known radical polymerization initiator can be appropriately selected and used.
Specifically, for example, 2,2′-azobis (2-methylpropionitrile), 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobisisobutyronitrile, 2 , 2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile), 1,1'-azobis (cyclohexanecarbonitrile), 2,2 Azobisnitriles such as' -azobis (2-amidinopropane) hydrochloride, acetyl peroxide, octanoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, decanoyl peroxide, lauroyl peroxide, benzoyl peroxide Diacyl peroxide such as oxide, di-t-butyl peroxide, t-butyl-α-cumyl peroxy And dialkyl peroxides such as dicumyl peroxide, t-butyl peroxyacetate, α-cumyl peroxypivalate, t-butyl peroxyoctoate, t-butylperoxyneodecanoate, t-butylperoxy Peroxyesters such as laurate, t-butylperoxybenzoate, di-t-butylperoxyphthalate, di-t-butylperoxyisophthalate, t-butylhydroperoxide, 2,5-dimethylhexane-2, Hydroperoxides such as 5-dihydroperoxide, cumene hydroperoxide, di-isopropylbenzene hydroperoxide, organic peroxides such as peroxycarbonate such as t-butylperoxyisopropyl carbonate, inorganic such as hydrogen peroxide Peroxides, Examples include radical polymerization initiators such as persulfates such as potassium persulfate, sodium persulfate, and ammonium persulfate. A redox polymerization initiator may be used in combination.
The polymerization initiator can be added to a mixture containing a polycondensable monomer or a polycondensation resin, but can also be added to an aqueous medium. Moreover, it can also add to both. It can also be added before emulsification dispersion and can also be added after emulsification dispersion.
Among these, it is preferable to add the polymerization initiator to the aqueous medium after polycondensing the emulsion dispersion containing the polycondensable monomer and the addition polymerizable monomer.

The addition polymerizable resin obtained by polymerizing the addition polymerizable monomer is preferably a vinyl resin. The glass transition point of the addition polymerizable resin is preferably 18.0 ° C or higher, more preferably 20.0 to 80.0 ° C, and further preferably 22.0 to 70.0 ° C. It is preferable that Tg is within the above range since both image storage properties and fixing properties can be achieved.
Moreover, it is preferable that the weight average molecular weight (Mw) of the addition polymerizable resin obtained is 1,500-50,000, and it is more preferable that it is 2,000-40,000. The number average molecular weight (Mn) is preferably 1,000 to 10,000, and more preferably 2,000 to 60,000. It is preferable that the weight average molecular weight and the number average molecular weight are in the above ranges since both image storage properties and fixing properties can be achieved.

In the present invention, the resin particles of the resin emulsion preferably have an average particle diameter (center diameter) of 50 to 1,000 nm, more preferably 50 to 500 nm, and even more preferably 50 to 300 nm. .
When the average particle diameter (center diameter) of the resin emulsion is 50 to 1,000 nm, even when plain paper is used as the recording medium, it does not penetrate deeply into the fiber of the paper after printing, Even if the addition amount of the resin emulsion is small, the coating film is efficiently formed on the surface of the printed image and the object of the present invention is achieved.
Here, the average particle diameter is synonymous with the center diameter, and means a volume median diameter (D ₅₀ ). The volume median diameter (D ₅₀ ) can be measured using a laser diffraction particle size distribution measuring device or the like.

In the emulsion ink of the present invention, the resin emulsion preferably has a self-forming property, and the minimum film-forming temperature (MFT) of the resin emulsion is preferably 20 ° C. or less. As for minimum film forming temperature (MFT), it is more preferable that it is 18-1.0 degreeC, and it is further more preferable that it is 16-5.0 degreeC.
When the minimum film-forming temperature (MFT) is 20 ° C. or less, a resin film made of the resin emulsion is formed on the surface of the print image even when it is naturally dried without using a special heating means after forming a print image on a recording medium. Is formed, and the surface is protected, so that a printed image is vivid and an image having excellent wear resistance is obtained.
The minimum film-forming temperature (MFT) is the lowest temperature at which a uniform film without cracks is formed when the resin emulsion is dried, and is measured according to JIS K 6828-2.

  Here, the mechanism of self-film formation generally has a tendency that the higher the Tg, the higher the minimum film-forming temperature. Tg is determined by the resin type and molecular weight, whereas MFT (minimum film-forming temperature). Is a physical property that varies depending on the particle size of the resin particles, the surface state of the particles, the affinity with the solvent, etc., in addition to the resin type and molecular weight. The emulsion in water polycondensation has a minimum particle formation temperature due to its particle size distribution, surface polar groups, and surface charge, and can be fixed by natural film formation without using special equipment or heat. In the present invention, the resin particles are preferably prepared by polycondensation in an aqueous medium. Conventional acrylic latexes have a problem that if the Tg is designed to be low for the purpose of lowering the minimum film-forming temperature, the storage stability and ejection performance of the ink are lowered.

<Emulsion ink>
The emulsion ink according to the present invention comprises at least the colorant (preferably pigment), the resin emulsion, and water. The amount of the colorant added to the emulsion ink is preferably 2 to 15% by weight, more preferably about 4 to 10% by weight. The addition amount of the resin emulsion is preferably 1 to 30% by weight, more preferably about 3 to 20% by weight as the resin component. The emulsion ink of the present invention may contain a water-miscible organic solvent as necessary. In addition, water, a water-miscible organic solvent, and a mixture thereof are referred to as an aqueous medium in this specification.

  According to a preferred embodiment of the present invention, the emulsion ink according to the present invention preferably contains glycols in order to prevent clogging of the nozzles of the ink jet recording head. As glycols, water-soluble glycols are preferable, and examples thereof include thioglycol, ethylene glycol, diethylene glycol, tritylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, neopentyl glycol, polyethylene having a molecular weight of 600 or less. Glycol, 1,3-propylene glycol, isopropylene glycol, isobutylene glycol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2-ethyl-1, Examples include 3-hexanediol, glycerin, mesoerythritol, pentaerythritol, 2-methyl-2,4-pentanediol, trimethylolpropane, and trimethylolethane.

  Further, as preferred components for further effectively preventing nozzle clogging, thiodiglycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2-ethyl-1,3-hexanediol , Propylene glycol, dipropylene glycol, tripropylene glycol, neopentyl glycol, 2-methyl-2,4-pentanediol, trimethylolpropane, trimethylolethane and the like, and the like. The amount of these components that prevent clogging may be appropriately determined within a range that achieves prevention of clogging, but in the case of glycols, it is preferably about 3 to 25% by weight.

  According to a preferred embodiment of the present invention, the emulsion ink according to the present invention improves the solubility of glycol ethers having low solubility in water, further improves the permeability to the recording medium such as paper, or clogs the nozzles. In order to prevent this, other water-soluble organic solvents may be included. Preferred examples of the water-soluble organic solvent include C1-C4 alkyl alcohols such as ethanol, methanol, butanol, propanol, and isopropanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, and ethylene glycol monomethyl. Ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, ethylene glycol mono-iso-propyl ether, diethylene glycol mono-iso-propyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol mono-t -Butyl ether, diethylene glycol mono-t-butyl ether 1-methyl-1-methoxybutanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-t-butyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-iso-propyl ether, dipropylene glycol monomethyl Glycol ethers such as ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-iso-propyl ether, formamide, acetamide, dimethyl sulfoxide, sorbit, sorbitan, acetin, diacetin, triacetin , Sulfolane, 2-pyrrolidone and the like. The addition amount is preferably about 5 to 60% by weight with respect to the total amount of the emulsion ink.

  The emulsion ink according to the present invention may contain an alkyl ether carboxylate surfactant as required. Examples of the alkyl ether carboxylate surfactant include ECT-3NEX, ECTD-3NEX, ECTD-6NEX, ECT-3, ECT-7, AKYPO RLM 45NV (CHEM-Y), AKYPO RLM45 (manufactured by Nikko Chemicals Co., Ltd.) CHEM-Y), AKYPO RLM100NV (CHEM-Y), AKYPO RLM100 (CHEM-Y), or the like can be used. In particular, it is preferable to use ECTD-3NEX or ECTD-6NEX because good recording quality is exhibited.

  The addition amount of these alkyl ether carboxylate surfactants is preferably about 0.1 to 5% by weight, more preferably 0.5 to 1.5% by weight of the emulsion ink. Alkyl ether carboxylates in the above range are preferable because they reduce bleeding. According to a preferred embodiment of the present invention, the emulsion ink according to the present invention can comprise other surfactants in order to control its permeability. The surfactant is preferably one having good compatibility with the emulsion ink, and among the surfactants, one having high permeability and stability is preferable. Preferred examples thereof include amphoteric surfactants and nonionic surfactants.

  Examples of amphoteric surfactants include lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine and other imidazoline derivatives. is there. Nonionic surfactants include polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene Ethers such as ethylene alkyl ether and polyoxyalkylene alkyl ether, polyoxyethylene oleic acid, polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquis Esters such as oleate, polyoxyethylene monooleate, polyoxyethylene stearate, etc. Kill esters, fluorine-containing surfactants such as perfluoroalkyl carboxylic acid salts, and the like.

  According to a preferred embodiment of the present invention, the emulsion ink according to the present invention can comprise saccharides. Addition of sugars is preferable because clogging of the nozzles of the ink jet recording head can be effectively prevented. The saccharide may be a monosaccharide or a polysaccharide, and specific examples thereof include glucose, mannose, fructose, ribose, xylose, arabinose, lactose, galactose, aldonic acid, glucitolose, maltose, cellobiose, sucrose, trehalose, In addition to maltotriose, alginic acid and its salts, cyclodextrins, and celluloses can be mentioned. The addition amount is preferably about 1% to 10%, more preferably 3 to 7%.

  In addition, according to a preferred embodiment of the present invention, the emulsion ink according to the present invention comprises a preservative, a fungicide, a pH adjuster, a dye dissolution aid, or an antioxidant, and an electrical conductivity adjuster in order to improve various properties. Agents, surface tension adjusters, oxygen absorbers and the like.

  Preferred examples of the antiseptic and fungicide include sodium benzoate, sodium pentachlorophenol, sodium 2-pyridinethiol-1-oxide, sodium sorbate, sodium dehydroacetate, 1,2-dibenzisothiazoline-3 -ON (Proxel CRL, Proxel BDN, Proxel GXL, Proxel XL-2, Proxel TN from ICI) and the like.

  Examples of pH adjusters, dye solubilizers and antioxidants include amines such as diethanolamine, triethanolamine, propanolamine, morpholine and their modified products, potassium hydroxide, sodium hydroxide, lithium hydroxide. Inorganic salts such as ammonium hydroxide, quaternary ammonium hydroxide (tetramethylammonium etc.), carbonates such as potassium carbonate, sodium carbonate, lithium carbonate and other phosphates, or N-methyl-2-pyrrolidone, urea, thio Examples include ureas such as urea and tetramethylurea, allophanates such as allophanate and methyl allophanate, burettes such as burette, dimethyl burette, and tetramethyl burette, and L-ascorbic acid and salts thereof.

The emulsion ink according to the present invention can contain an antioxidant and an ultraviolet absorber. Examples of such commercially available products include Tinuvin 328, 900, 1130, 384, 292, 123, 144, 622, 770, 292, Irgacor 252, 153, Irganox 1010, 1076, 1035, MD1024 and the like manufactured by Ciba Geigy.
The emulsion ink according to the present invention can comprise a viscosity modifier. Specific examples thereof include rosins, alginic acids, polyvinyl alcohol, hydroxypropylcellulose, carboxymethylcellulose, hydroxyethylcellulose, methylcellulose, polyacrylate, polyvinylpyrrolidone, gum arabic starch and the like.

  The ink-jet emulsion ink of the present invention can be applied to any ink-jet recording system, for example, a charge control system that ejects ink using electrostatic attraction, a drop-on-demand system (pressure) that uses the vibration pressure of a piezo element Pulse system), acoustic ink jet system that changes electrical signal into acoustic beam, irradiates ink and ejects ink by using radiation pressure, and thermal ink jet that heats ink to form bubbles and uses generated pressure ( It is suitably used for a bubble jet (registered trademark) system.

  The ink jet recording method includes a method of ejecting a large number of low-density inks called photo inks in a small volume, and a method of improving image quality using a plurality of inks having substantially the same hue and different densities.

  EXAMPLES Next, although an Example and a comparative example are given and this invention is demonstrated further more concretely, this invention is not limited at all by these examples.

[Preparation of resin emulsion]
<Resin emulsion (A1)>
Ethylene oxide 4 mol adduct of bisphenol A 28.5 parts by weight 1,4-cyclohexanedicarboxylic acid (cis form) 17.0 parts by weight Paratoluenesulfonic acid 0.8 parts by weight The above ingredients are mixed in a flask, and the mantle After heating to 120 ° C. with a heater and melting the mixture, the contents became a viscous melt when held at 90 ° C. for 8 hours with stirring and degassing with a three-one motor. Similarly, an aqueous solution for neutralization in which 2.0 parts by weight of 1N NaOH was dissolved in 650 parts by weight of ion-exchanged water heated to 90 ° C. was put into the flask and emulsified with a homogenizer (manufactured by IKA, Ultra Tarrax) for 5 minutes. The flask was cooled with water at room temperature.
As a result, the center diameter of the fine particles was 280 nm, the Tg (glass transition point) was 35 ° C., the weight average molecular weight was 12,000, the number average molecular weight was 4,500, the acid value was 21 mg / KOH, and the amorphous content was 20%. A resin particle emulsion (A1) was obtained.

<Resin emulsion (A2)>
Propylene oxide 2 mol adduct of bisphenol A 51.0 parts by weight Phenylenediacetic acid 16.8 parts by weight Trimellitic anhydride 2.0 parts by weight The above materials are mixed in a flask and heated to 120 ° C. with a mantle heater, After melting the mixture, it was kept at 90 ° C. for 8 hours while stirring and degassing with a three-one motor, and the contents became a viscous melt. Similarly, an aqueous solution for neutralization in which 2.0 parts by weight of 1N NaOH was dissolved in 650 parts by weight of ion-exchanged water heated to 90 ° C. was put into the flask and emulsified with a homogenizer (manufactured by IKA, Ultra Tarrax) for 5 minutes. The flask was cooled with water at room temperature.
Thus, an amorphous resin particle emulsion (A2) having a fine particle center diameter of 150 nm, a Tg (glass transition point) of 55 ° C., a weight average molecular weight of 13,000, a number average molecular weight of 5,500, and a solid content of 20%. Got.

<Resin emulsion (A3)>
Dodecylbenzenesulfonic acid 1.0 part by weight Ion exchange water 1000 parts by weight The above components were mixed and dissolved.
(Polycondensable monomer)
Ethylene oxide 4 mol adduct of bisphenol A 28.5 parts by weight Phenylenedipropionic acid 17.0 parts by weight Dodecylbenzenesulfonic acid 0.8 parts by weight (vinyl monomer)
Styrene 25 parts by weight n-butyl acrylate 7 parts by weight Acrylic acid 3 parts by weight The above components were mixed, heated to about 100 ° C. and melted, and then poured into the above-mentioned aqueous dodecylbenzenesulfonic acid solution, and homogenizer (manufactured by IKA, After emulsifying for 5 minutes with Ultra-Turrax), the nanomizer emulsifier (manufactured by Yoshida Kikai Co., Ltd.) was further removed, and after 10 passes of repeated emulsification, the emulsion was stirred at 80 ° C. in a nitrogen atmosphere while stirring the emulsion. And maintained for 8 hours. Further, 10 parts by weight of ion-exchanged water in which 0.35 part by weight of ammonium persulfate was dissolved as a radical polymerization initiator was added and kept at 80 ° C. for another 5 hours.
As a result, a resin particle emulsion (A3) having a fine particle center diameter of 280 nm, a polyester resin Tg of 41 ° C., a weight average molecular weight of 6,500, a number average molecular weight of 1,400, and a solid content of 25% was obtained. . At this time, the copolymer of styrene / n-butyl acrylate / acrylic acid had a Tg of 43 ° C., a weight average molecular weight of 12,000, and a number average molecular weight of 3,900.

<Resin emulsion (A4)>
Cyclohexanedimethanol 39.8 parts by weight Neopentylglycol 4.0 parts by weight Cyclohexanedicarboxylic acid 15.5 parts by weight Branched dodecylbenzenesulfonic acid 0.5 parts by weight The above materials were charged into a three-necked reactor and stirred at 120 ° C. for 10 hours. Mixed. When the molecular weight was measured by GPC, it was revealed that oligomers of Mw 5,850 and Mn 1,800 were synthesized. To this composition, 15 parts by weight of butylated melamine formaldehyde resin (Super Becamine J-820.60) (manufactured by Dainippon Ink & Chemicals, Inc.) as an amino resin was added and held at a temperature of 80 ° C. for 4 hours. Thus, a partially crosslinked amino-modified polyester resin (prepolymer) was obtained.

Similarly, an aqueous solution for neutralization in which 2.0 parts by weight of 1N NaOH was dissolved in 650 parts by weight of ion-exchanged water heated to 90 ° C. was put into the flask and emulsified with a homogenizer (manufactured by IKA, Ultra Tarrax) for 5 minutes. The flask was cooled with water at room temperature.
As a result, a resin particle emulsion (A4) having a fine particle center diameter of 450 nm, a Tg of 45 ° C., a weight average molecular weight of 20,000, a number average molecular weight of 3,600, and a solid content of 20% was obtained.

<Resin emulsion (A5)>
Styrene 25 parts by weight Sodium styrenesulfonate 5 parts by weight Sodium dodecylbenzenesulfonate 0.6 part by weight Potassium persulfate 0.2 part by weight Ion-exchanged water 69.2 parts by weight The above composition was heated at 70 ° C. under a nitrogen stream for 12 hours. Stirring to obtain a resin emulsion. As a result, a resin particle emulsion (A5) having a fine particle central diameter of 28 nm, a Tg of 95 ° C., a weight average molecular weight of 18,000, a number average molecular weight of 4,100, and a solid content of 20% was obtained.

<Resin emulsion (A6)>
Ethyl methacrylate 30 parts by weight Potassium persulfate 0.1 part by weight Ion exchange water 69.9 parts by weight The above composition was stirred at 70 ° C. for 12 hours under a nitrogen stream to obtain a resin emulsion. As a result, a resin particle emulsion (A6) having a fine particle center diameter of 74 nm, a Tg of −5 ° C., a weight average molecular weight of 14,000, a number average molecular weight of 5,900, and a solid content of 20% was obtained.

[Emulsion characteristics]
<Minimum film-forming temperature (MFT)>
The resin emulsion is thinly coated on a glass plate, dried by applying a temperature gradient, and the temperature at the boundary between where a white powdery precipitate is formed and where a transparent thin film is formed is determined as the minimum film-forming temperature (MFT). ).

<Glass transition point (Tg)>
It measured by the differential scanning calorimetry (DSC).
<Average particle diameter (center diameter)>
It measured with the light-scattering type particle size distribution analyzer.

<Polarity of particles>
The zeta potential of the emulsion was measured with a zeta electrometer (Zetasizer 11, manufactured by MAIVERN). The measurement was performed 5 times or more and the average value was calculated.
The polarity of the latex (resin particles) can be measured with a zeta potentiometer, but this measurement method can also be applied to ink. That is, when 10 g of ink is weighed into a glass test tube and set in a 12-angle rotor of KOKUSAN H18, and centrifuged at 2,000 × g for 30 minutes, a latex supernatant is produced in the upper layer of the test tube. The pigment component was precipitated. From the zeta potential of this supernatant part, the polarity of latex can be collected, and the pigment part can be collected to measure the polarity of pigment.
The results are listed in Table 1.

[Preparation of emulsion ink]
<Example 1>
An emulsion ink having the following formulation was prepared and adjusted with a 10% aqueous solution of lithium hydroxide so that the pH was 8.2. Thereafter, the mixture was filtered through a membrane filter having an average pore diameter of 0.8 μm to obtain an emulsion ink 1.
Sulfon group-added carbon black 7.5% by weight
(Cabot Specialty Chemicals, Inc.) (as carbon)
Glycerin 5% by weight
Diethylene glycol 15% by weight
2-ethyl-1,3-hexanediol 2% by weight
2-pyrrolidone 2% by weight
Isopropyl alcohol 1% by weight
Resin emulsion (A1) 6% by weight
(As solids)
Ion exchange water

<Example 2>
Emulsion ink 2 was produced using the same method as in Example 1 according to the following formulation.
Quaternary ammonium group addition type carbon black 5% by weight
(Cabot Specialty Chemicals, Inc.) (as carbon)
Glycerin 5% by weight
Diethylene glycol 15% by weight
2-ethyl-1,3-hexanediol 2.5% by weight
2-pyrrolidone 2% by weight
Sodium alginate NSPLL 0.15% by weight
(Kibun Food Chemifa Co., Ltd.)
Resin emulsion (A4) 5% by weight
(As solids)
Ion exchange water

<Example 3>
Emulsion ink 3 was prepared in the same manner as in Example 1 except that the resin emulsion (A1) used in Example 1 was replaced with the resin emulsion (A2).

<Example 4>
Emulsion ink 4 was prepared in the same manner as in Example 1 except that the resin emulsion (A1) used in Example 1 was replaced with the resin emulsion (A3).

<Comparative Example 1>
Emulsion ink 5 was prepared in the same manner as in Example 1 except that the resin emulsion (A1) used in Example 1 was replaced with the resin emulsion (A4).

<Comparative example 2>
Emulsion ink 6 was prepared in the same manner as in Example 2 except that the resin emulsion (A4) used in Example 2 was replaced with the resin emulsion (A5).

<Comparative Example 3>
Emulsion ink 7 was prepared in the same manner as in Example 2, except that the resin emulsion (A4) used in Example 2 was replaced with the resin emulsion (A6).

<Comparative example 4>
Emulsion ink 8 was prepared in the same manner as in Example 1 except that the resin emulsion (A1) used in Example 1 was replaced with the resin emulsion (A5).

<Comparative Example 5>
Emulsion ink 8 was prepared in the same manner as in Example 1 except that the resin emulsion (A1) used in Example 1 was replaced with the resin emulsion (A6).

[Print test]
Printing was performed on plain paper with an inkjet printer IPSiO JET 300 (manufactured by Ricoh Co., Ltd.) using the emulsion inks prepared in Examples and Comparative Examples.
In this example, the heat treatment after discharge was not performed.

[Evaluation method]
<Discharge stability>
After confirming ejection from all nozzles, 20 test patterns were printed continuously, and ink ejection from all nozzles during or after printing was examined.
○: There was no ejection failure Δ: There were 1 to 5 non-ejection nozzles ×: There were 5 or more non-ejection nozzles

<Friction resistance of printed images>
The printed matter is rubbed 10 times with an eraser (made by Lion, # 501) at a pressing pressure of 50 g, and the print density before and after the test is measured using a spectrophotometric densitometer (made by X-Rite, # 938). evaluated. Thereby, the adhesiveness with the recording material can be evaluated.
Residual rate ○:> 80%
Δ: 60% to 80%
×: <60%

<Water resistance>
After dropping one drop of water on the printed image and air-drying it, the image bleeding (ink flow) was visually judged and evaluated in three stages.
A: Almost no bleeding B: Slight bleeding C: Large bleeding

<Image evaluation>
The obtained image was evaluated for image quality according to the following evaluation criteria. A 6-point “depression” was printed and graded.
A: Clearly readable B: Slight blurring C: Crushed and unreadable A was set to pass.
The results are shown in Table 2.

Claims (10)

An addition obtained by polymerizing a polycondensation resin obtained by polycondensation of at least one selected from the group consisting of polycondensable monomers, oligomers and prepolymers thereof, and an addition polymerizable monomer containing styrene. resin particles containing a polymerizable resin, and a jet emulsion ink containing a colorant,
The polycondensation resin contains polyester and / or polyamide,
An ink-jet emulsion ink, wherein the resin particles and the colorant have a charge of the same polarity.   The emulsion ink for inkjet according to claim 1, wherein the polycondensation resin contains an amorphous polyester having a glass transition point of 30C to 100C.   The emulsion ink for inkjet according to claim 1 or 2, wherein the glass transition temperature of the addition polymerizable resin is 18.0 ° C or higher and 80.0 ° C or lower.   The inkjet emulsion ink according to any one of claims 1 to 3, wherein the addition amount of the colorant is 2 to 15% by weight and the addition amount of the resin particles is 1 to 30% by weight.   The emulsion ink for inkjet according to any one of claims 1 to 4, wherein the resin particles have an average particle diameter of 50 to 500 nm. At least one selected from the group consisting of polycondensable monomers, oligomers and prepolymers thereof, and an addition polymerizable monomer containing styrene are mixed, emulsified in an aqueous medium, and the polycondensable monomer body, oligomers thereof and at least one selected from the group consisting of a prepolymer polycondensation, addition, the addition-polymerizable monomer to polymerization according to claim 1, characterized in that it comprises a step of obtaining a resin emulsion ~ 5. A method for producing an ink-jet emulsion ink as described in any one of 5 above.   The method for producing an emulsion ink for inkjet according to claim 6, wherein the polycondensation is carried out using a Bronsted acid containing a sulfur atom as a catalyst.   The method for producing an emulsion ink for inkjet according to claim 6 or 7, further comprising a step of adding a colorant to the resin emulsion. In the ink jet recording method for performing printing by ejecting ink droplets from a recording head and attaching the droplets to a recording medium, the emulsion ink according to any one of claims 1 to 5 is used as the ink. An inkjet recording method. A recorded matter obtained by the recording method according to claim 9 .