JP6844836B2 - Liquid developer Aqueous dispersion for forming a receptive layer - Google Patents

Description

The present invention relates to an aqueous dispersion for forming a liquid developer receiving layer, a resin recording medium, a method for producing a resin recording medium, and an image forming method.

The electrophotographic developer includes a dry developer that uses toner particles made of a material containing a colorant and a binder resin in a dry state, and a liquid developer in which the toner particles are dispersed in an insulating carrier liquid. The liquid developer is excellent in terms of image quality because it can reduce the particle size of toner particles, and is suitable for commercial printing applications.
In fields such as commercial label printing used for product packaging printing and advertising, printing has been performed on resin recording media such as polyethylene terephthalate and polypropylene.

Patent Document 1 describes, in a statically charged liquid developing system in which the recorded material is a plastic film or sheet, a recorded material for statically charged developing liquid toner, wherein the plastic film or sheet is coated with a primer. It is described that the recorded material significantly improves the adhesion between the film or sheet and the toner in the electrophotographic liquid developing method.

Japanese Unexamined Patent Publication No. 9-179329

When printing on a resin recording medium by an electrophotographic method using a liquid developer, the characteristics such as the fixability of toner particles to the recording medium are likely to fluctuate due to factors such as the polarity of the resin of the recording medium, and the resin. A resin or the like that improves the fixability of toner particles is applied to the production recording medium. However, when recording media coated with resin or the like are stacked and stored for a long period of time, there is a problem in storage stability after coating, such as sticking to the coated surface. There is a demand for an aqueous dispersion for forming a liquid developer receiving layer, which is excellent in fixing to a resin recording medium.
INDUSTRIAL APPLICABILITY The present invention improves the fixability of toner particles contained in a liquid developer to a resin recording medium, and further, an aqueous dispersion liquid for forming a liquid developer receiving layer and a resin recording medium having excellent storage stability after coating. , A method for producing a resin recording medium, and a method for forming an image.

The present inventors have combined an aqueous dispersion containing predetermined polyester resin particles (A), at least one resin particle (B) selected from polyurethane resin particles and modified polyolefin resin particles, and a predetermined organic solvent. It was found that the above-mentioned problems can be solved by using.

The present invention relates to the following [1] to [4].
[1] Contains polyester resin particles (A), at least one resin particle (B) selected from polyurethane resin particles and modified polyolefin resin particles, and an organic solvent having a boiling point of 100 ° C. or higher and 250 ° C. or lower.
An aqueous dispersion for forming a liquid developer receiving layer, wherein the mass ratio of the polyester resin particles (A) to the resin particles (B) is 55/45 or more and 95/5 or less.
[2] A resin recording medium provided with the aqueous dispersion according to [1].
[3] A method for producing a resin recording medium with a liquid developer receiving layer, which comprises a step of forming a receiving layer on a resin recording medium using the aqueous dispersion according to [1].
[4] An image forming method comprising a step of forming an image on a receiving layer of a resin recording medium obtained by the method of [3] using a liquid developer containing toner particles.

According to the present invention, an aqueous dispersion liquid for forming a liquid developer receiving layer, which is made of resin, improves the fixability of toner particles contained in a liquid developer to a resin recording medium and further has excellent storage stability after coating. A recording medium, a method for producing a resin recording medium, and a method for forming an image can be provided.

[Aqueous dispersion for forming a liquid developer receiving layer]
The aqueous dispersion for forming the liquid developer receiving layer of the present invention (hereinafter, also simply referred to as “aqueous dispersion (I)”) is selected from at least polyester resin particles (A), polyurethane resin particles, and modified polyolefin resin particles. It contains one type of resin particles (B) and an organic solvent having a boiling point of 100 ° C. or higher and 250 ° C. or lower.
The mass ratio of the polyester resin particles (A) and the resin particles (B) is 55/45 or more and 95/5 or less.
As a result, the fixability of the toner particles contained in the liquid developer to the resin recording medium (hereinafter, also simply referred to as “fixability”) is improved, and further, the storage stability after coating (hereinafter, simply “preservability”) is improved. An aqueous dispersion for forming a liquid developer receiving layer, a resin recording medium, a method for producing a resin recording medium, and an image forming method can be provided.

The mechanism by which the effect of the present invention is obtained is not clear, but it is considered as follows.
A liquid developer using polyester as a binder resin has low affinity with resin recording media such as polyethylene terephthalate (hereinafter, also referred to as "PET") film and polypropylene (hereinafter, also referred to as "PP") film, and is made of resin. Insufficient fixability on recording medium. On the other hand, by containing at least one of a polyurethane resin or a modified polyolefin resin having a high affinity with a PET film or a PP film as an aqueous dispersion liquid for forming a liquid developer receiving layer, a recording medium made of these resins can be used. Adhesion with the receiving layer formed by the aqueous dispersion for forming the receiving layer of the liquid developer is improved. Further, by incorporating the polyester resin in the aqueous dispersion for forming the liquid developer receiving layer, the affinity of the liquid developer using the polyester resin with the toner particles is increased, and the adhesion is improved. By using a solution containing both toner particles and a resin having good adhesion to a resin recording medium in a specific mass ratio as an aqueous dispersion for forming a liquid developer receiving layer, it is included in the liquid developer. It is considered that the fixability of the toner particles to the resin recording medium can be improved.
Further, by containing an organic solvent having a boiling point of 100 ° C. or higher and 250 ° C. or lower, the film formation of the resin is maintained while maintaining good printability when forming the receiving layer with the aqueous dispersion for forming the receiving layer of the liquid developer. It is considered that the properties are improved and the organic solvent dries quickly after the treatment, so that sticking between the recording media after the treatment can be suppressed.

The "aqueous dispersion" means a dispersion in which the proportion of water in the liquid components at room temperature is 50% by mass or more.
In the aqueous dispersion (I), the mass ratio (A / B) of the polyester resin particles (A) and the resin particles (B) is 55/45 or more from the viewpoint of obtaining the aqueous dispersion (I) having excellent fixability. It is preferably 60/40 or more, more preferably 70/30 or more, still more preferably 75/25 or more, and 95/5 or less from the viewpoint of obtaining an aqueous dispersion (I) having excellent storage stability. Yes, preferably 90/10 or less, more preferably 85/15 or less.
In the aqueous dispersion (I), the total content of the polyester resin particles (A) and the resin particles (B) is the aqueous dispersion (I) from the viewpoint of obtaining the aqueous dispersion (I) having excellent fixability and storage stability. ), More preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 20% by mass or more, and preferably 50% by mass or less, more preferably 45% by mass or less, still more preferably 40% by mass. % Or less.
Hereinafter, each component of the aqueous dispersion (I) will be described in detail.

<Polyester resin particles (A)>
The polyester resin particles (A) contain polyester from the viewpoint of obtaining an aqueous dispersion (I) having excellent fixability and storage stability.

〔polyester〕
Polyester is obtained by polycondensing an alcohol component and a carboxylic acid component. That is, the polyester is a polycondensate of an alcohol component and a carboxylic acid component.

(Alcohol component)
Examples of the alcohol component include diols, trihydric or higher polyhydric alcohols, and the like, and diols are preferable.
Examples of the diol include a linear or branched aliphatic diol having 2 to 20 carbon atoms, an aromatic diol, and an alicyclic diol.

The aliphatic diol is preferably an aliphatic diol having a hydroxy group bonded to a secondary carbon atom and having 3 to 8 carbon atoms from the viewpoint of further improving the fixability and storage stability.
Examples of the aliphatic diol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, and 1,9-. Examples thereof include nonanediol, 1,10-decanediol, and 1,12-dodecanediol.
Examples of the aliphatic diol having a hydroxy group bonded to a secondary carbon atom and having 3 or more and 8 or less carbon atoms include 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, and 2, 3-butanediol, 1,2-pentanediol, 1,4-pentanediol, 2,4-pentanediol, 1,2-hexanediol, 1,5-hexanediol, 2,5-hexanediol, 3,3 -Diol-1,2-butanediol and the like can be mentioned. Among these, 1,2-propanediol and 2,3-butanediol are preferable, and 1,2-propanediol is more preferable.

Examples of the aromatic diol include an alkylene oxide adduct of bisphenol A.
The alkylene oxide adduct of bisphenol A is preferably of the formula (I): from the viewpoint of further improving the fixability and storage stability.

[In the formula, RO and OR are oxyalkylene groups, R is at least one selected from an ethylene group and a propylene group, and x and y indicate the average number of moles of alkylene oxide added, which are positive numbers, respectively. , The value of the sum of x and y is 1 or more, preferably 1.5 or more, and 16 or less, preferably 8 or less, more preferably 4 or less. ] Is an alkylene oxide adduct of bisphenol A.
Examples of the alkylene oxide adduct of bisphenol A represented by the formula (I) include a propylene oxide adduct of 2,2-bis (4-hydroxyphenyl) propane and 2,2-bis (4-hydroxyphenyl) propane. Ethylene oxide adducts of. These can be used alone or in combination of two or more. Among these, a propylene oxide adduct of 2,2-bis (4-hydroxyphenyl) propane is preferable.

Examples of the alicyclic diol include cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A and the like.

Among these, the alcohol component is preferably an alkylene oxide adduct of bisphenol A, hydrogenated bisphenol A, and a carbon having a hydroxy group bonded to a secondary carbon atom from the viewpoint of further improving fixability and storage stability. At least one selected from aliphatic diols having a number of 3 or more and 8 or less, more preferably an alkylene oxide adduct of bisphenol A and a hydroxy group bonded to a secondary carbon atom having 3 or more and 8 or less carbon atoms. At least one selected from aliphatic diols, more preferably an alkylene oxide adduct of bisphenol A, and even more preferably a propylene oxide adduct of bisphenol A.

The content of the diol in the alcohol component of the polyester is preferably 50 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, and from the viewpoint of further improving the fixability and storage stability. , 100 mol% or less.

(Carboxylic acid component)
Examples of the carboxylic acid component include a dicarboxylic acid and a trivalent or higher valent carboxylic acid.
In the specification, the carboxylic acid component of polyester includes not only the compound but also an anhydride that decomposes during the reaction to generate an acid, and an alkyl ester having 1 to 3 carbon atoms of each carboxylic acid. ..

Examples of the dicarboxylic acid include an aromatic dicarboxylic acid, a linear or branched aliphatic dicarboxylic acid, and an alicyclic dicarboxylic acid.
Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, and terephthalic acid. Of these, terephthalic acid is preferable.
Examples of the linear or branched aliphatic dicarboxylic acid include fumaric acid, adipic acid, sebacic acid, maleic acid, azelaic acid, succinic acid, an alkyl group having 1 to 20 carbon atoms or an alkenyl having 2 to 20 carbon atoms. Examples include succinic acid substituted with a group. Examples of the succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms include dodecyl succinic acid, dodecenyl succinic acid, and octenyl succinic acid. Among these, adipic acid and fumaric acid are preferable.

Examples of the alicyclic dicarboxylic acid include cyclohexanedicarboxylic acid.
The trivalent or higher valent carboxylic acid is preferably a trivalent carboxylic acid, and examples thereof include trimellitic acid, 2,5,7-naphthalene tricarboxylic acid, and pyromellitic acid.
These can be used alone or in combination of two or more.

The carboxylic acid component is preferably at least one selected from isophthalic acid, terephthalic acid, fumaric acid, adipic acid, sebacic acid, and dodecenyl succinic acid from the viewpoint of further improving fixability and storage stability, and more preferably. , Terephthalic acid, fumaric acid and adipic acid.

The molar equivalent ratio (COOH group / OH group) of the carboxy group (COOH group) of the carboxylic acid component to the hydroxy group (OH group) of the alcohol component is preferably 0.65 or more, more preferably 0.80 or more. And it is preferably 1.2 or less, more preferably 1.1 or less.

(Polyester manufacturing method)
Polyester can be produced by subjecting a carboxylic acid component and an alcohol component to a polycondensation reaction. For example, it can be produced by polycondensing an alcohol component and a carboxylic acid component in an inert gas atmosphere at a temperature of 120 ° C. or higher and 250 ° C. or lower, if necessary, using an esterification catalyst and a polymerization inhibitor. it can.
As the esterification catalyst, an esterification catalyst such as a tin compound such as dibutyltin oxide or di (2-ethylhexanoic acid) tin (II) or a titanium compound such as titanium diisopropyrate bistriethanolamite can be used. ..
The amount of the esterification catalyst used is not limited, but is preferably 0.01 part by mass or more, more preferably 0.1 part by mass or more, and more preferably 0.1 part by mass or more, based on 100 parts by mass of the total amount of the carboxylic acid component and the alcohol component. It is preferably 1.5 parts by mass or less, more preferably 1.0 parts by mass or less.
In addition, a radical polymerization inhibitor can be used if necessary. Examples of the radical polymerization inhibitor include 4-tert-butylcatechol and the like. The amount of the radical polymerization inhibitor used is preferably 0.001 part by mass or more, more preferably 0.005 part by mass or more, and preferably 0.005 part by mass or more, based on 100 parts by mass of the total amount of the carboxylic acid component and the alcohol component. It is 0.5 parts by mass or less, more preferably 0.1 parts by mass or less.

(Physical characteristics of polyester)
The glass transition temperature of polyester is preferably 40 ° C. or higher, more preferably 45 ° C. or higher, further preferably 50 ° C. or higher, and preferably 80 ° C. or lower, from the viewpoint of further improving fixability and storage stability. It is preferably 70 ° C. or lower, more preferably 65 ° C. or lower, still more preferably 60 ° C. or lower.
The glass transition temperature of polyester is measured using a differential scanning calorimeter, and specifically, it is measured by the method of Examples.
The softening point of the polyester is preferably 70 ° C. or higher, more preferably 80 ° C. or higher, further preferably 90 ° C. or higher, and preferably 165 ° C. or lower, more preferably 165 ° C. or lower, from the viewpoint of further improving fixability and storage stability. Is 130 ° C. or lower, more preferably 110 ° C. or lower.

The acid value of the polyester is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, still more preferably 15 mgKOH / g or more, and more preferably 15 mgKOH / g or more, from the viewpoint of improving the dispersion stability of the resin particles in the aqueous medium. It is preferably 35 mgKOH / g or less, more preferably 30 mgKOH / g or less, still more preferably 25 mgKOH / g or less.

The softening point, glass transition temperature, and acid value of the polyester can all be obtained by appropriately adjusting the type of monomer used for producing the polyester, the blending ratio, the polycondensation temperature, and the reaction time. ..
The polyester may be used alone or in combination of two or more. When two or more kinds of polyesters are mixed and used, the glass transition temperature and the softening point thereof are values obtained by the method described in Examples as a mixture of two or more kinds of polyesters.

The polyester resin particles (A) may contain a resin other than polyester, for example, a resin such as a styrene-acrylic copolymer, an epoxy resin, or a polycarbonate, as long as the effects of the present invention are not impaired.
Further, the polyester resin particles (A) may contain an additive such as a reinforcing filler such as a fibrous substance, an antioxidant, an antiaging agent, etc. as an optional component as long as the effect of the present invention is not impaired. Good.

(Manufacturing method of polyester resin particles (A))
The polyester resin particles (A) are obtained by dispersing the above-mentioned resin containing polyester in an aqueous medium, and the polyester resin particles (A) used as a raw material for the dispersion liquid of the polyester resin particles (A) (hereinafter, the aqueous dispersion liquid (I)). ) Means the dispersion liquid (also referred to as “dispersion liquid (Ia)”)).
As the aqueous medium, a medium containing water as a main component is preferable. The content of water in the aqueous medium is preferably 80% by mass or more, more preferably 90% by mass or more, and 100% by mass or less, and even more preferably 100% by mass. As the water, deionized water, ion-exchanged water or distilled water is preferably used. Examples of components other than water include alcohol solvents such as methanol, ethanol, isopropanol and butanol; ketone solvents such as acetone and methyl ethyl ketone; and organic solvents such as ether solvents such as tetrahydrofuran.

Examples of the method for obtaining the dispersion liquid (Ia) of the polyester resin particles (A) include a method in which a resin containing polyester is added to an aqueous medium and a dispersion treatment is performed by a disperser or the like, and an aqueous medium is gradually added to the resin containing polyester. Examples thereof include a method of adding the resin to the phase inversion emulsification. Among these, the method by phase inversion emulsification is preferable.
As a phase inversion emulsification method, it is preferable to first dissolve a resin containing polyester in an organic solvent, then add an aqueous medium to this solution to invert the phase, and then remove the organic solvent. Hereinafter, the phase inversion emulsification method will be described.

(Phase inversion emulsification method)
First, a resin containing polyester is dissolved in an organic solvent to obtain a solution containing polyester. When a plurality of types of polyesters or resins other than polyesters are contained, a mixture of these polyesters and other resins may be used in advance, but these resins are simultaneously added to an organic solvent to dissolve them, and the polyester is used. A solution containing the above may be obtained.
Further, it is preferable to use a basic compound from the viewpoint of improving the affinity of the resin containing polyester for an aqueous medium and improving the dispersion stability of the resin particle dispersion liquid.
As a method for obtaining a solution containing polyester, a method in which a resin containing polyester and an organic solvent are placed in a container to dissolve them, then a basic compound is placed in a container and stirred with a stirrer to obtain a solution is preferable.
The operation of dissolving the resin containing polyester in an organic solvent and the subsequent addition of the basic compound are usually carried out at a temperature equal to or lower than the boiling point of the organic solvent.
As the organic solvent, a dialkyl ketone having an alkyl group having 1 to 3 carbon atoms such as acetone and methyl ethyl ketone is preferable, and more preferably methyl ethyl ketone, from the viewpoint that a resin containing polyester is dissolved and can be easily removed from the emulsion. Is.

The mass ratio of the organic solvent to the resin containing polyester [organic solvent / resin] is preferable from the viewpoint of dissolving the resin and facilitating the phase inversion to the aqueous medium and improving the dispersion stability of the resin particle dispersion liquid. Is 30/100 or more, more preferably 50/100 or more, still more preferably 70/100 or more, and preferably 500/100 or less, more preferably 300/100 or less, still more preferably 200/100 or less, and further. It is preferably 150/100 or less.

Examples of the basic compound include hydroxides of alkali metals such as sodium hydroxide and potassium hydroxide, and nitrogen-containing basic compounds such as ammonia, diethylamine, triethylamine, diethanolamine, and triethanolamine. From the viewpoint of improving the dispersion stability of the dispersion liquid (Ia), sodium hydroxide, potassium hydroxide and ammonia are preferable, and sodium hydroxide is more preferable.
The equivalent amount (mol%) of the basic compound to be used with respect to the acid group of the resin is preferably 10 mol% or more, more preferably 30 mol% or more, still more preferably 50 mol%, from the viewpoint of improving the dispersion stability of the resin particles. The above, and preferably 150 mol% or less, more preferably 120 mol% or less, still more preferably 100 mol% or less.
The equivalent amount (mol%) of the basic compound used can be calculated by the following formula. When the equivalent amount of the basic compound used is 100 mol% or less, it is synonymous with the degree of neutralization, and when the equivalent amount of the basic compound used exceeds 100 mol% in the following formula, the basic compound is the acid group of the resin. The degree of neutralization of the resin at this time is considered to be 100 mol%.
Equivalent to use of basic compound (mol%) = [{additional mass of basic compound (g) / equivalent of basic compound} / [{acid value of resin (mgKOH / g) x mass of resin (g)} / (56 x 1000)]] x 100
The basic compound is preferably used as an aqueous solution. The concentration of the basic compound in the basic aqueous solution is preferably 1% by mass or more, more preferably 3% by mass or more, and preferably 3% by mass or more, from the viewpoint of improving the dispersion stability and productivity of the resin particle dispersion. It is 60% by mass or less, more preferably 50% by mass or less.

Next, an aqueous medium is added to the solution containing polyester to invert the phase to obtain a dispersion liquid (Ia) of resin particles containing polyester.
The temperature at which the aqueous medium is added is preferably 10 ° C. or higher, more preferably 20 ° C. or higher, still more preferably 25 ° C. or higher, and preferably 25 ° C. or higher, from the viewpoint of improving the dispersion stability of the dispersion liquid (Ia). Is 80 ° C. or lower, more preferably 65 ° C. or lower, still more preferably 50 ° C. or lower.

From the viewpoint of improving the dispersion stability of the dispersion liquid (Ia), the addition rate of the aqueous medium is preferably 0.5 part by mass with respect to 100 parts by mass of the resin constituting the resin particles until the phase inversion is completed. / Min or more, more preferably 1 part by mass or more, still more preferably 3 parts by mass or more, and preferably 50 parts by mass or less, more preferably 20 parts by mass or less, still more preferably. It is 15 parts by mass or less. There is no limit to the rate of addition of the aqueous medium after the phase inversion and after the resin particles are obtained.
The amount of the aqueous medium added is preferably 50 parts by mass or more, more preferably 100 parts by mass or more, and further, with respect to 100 parts by mass of the resin constituting the resin particles, from the viewpoint of improving the productivity of the dispersion liquid (Ia). It is preferably 150 parts by mass or more, preferably 900 parts by mass or less, more preferably 500 parts by mass or less, and further preferably 300 parts by mass or less.

After the phase inversion emulsification, if necessary, the organic solvent may be removed from the dispersion obtained by the phase inversion emulsification.
The method for removing the organic solvent is not particularly limited, and any method can be used, but distillation is preferable because it is dissolved in water.
The dispersion liquid (Ia) of the polyester resin particles (A) thus obtained is preferably filtered through a wire mesh or the like to remove coarse particles or the like. Further, when the organic solvent is removed, water is azeotropically reduced together with the organic solvent, so it is preferable to add water to adjust the solid content concentration.
The solid content concentration of the dispersion liquid (Ia) of the adjusted polyester resin particles (A) is preferably 5% by mass or more, more preferably 10% by mass, from the viewpoint of obtaining excellent adhesion to various resin recording media. As mentioned above, it is more preferably 20% by mass or more, further preferably 25% by mass or more, and preferably 50% by mass or less, more preferably 45% by mass or less.

The volume average particle size of the polyester resin particles in the dispersion (Ia) (A) (D V) is the viewpoint of improving the dispersion stability of in an aqueous dispersion (I), excellent in various resinous recording medium From the viewpoint of obtaining adhesion, it is preferably 10 nm or more, more preferably 20 nm or more, further preferably 30 nm or more, and preferably 500 nm or less, more preferably 200 nm or less, still more preferably 100 nm or less. The volume average particle diameter ( _DV ) is measured by a dynamic light scattering method, and is determined by the method described in Examples.

From the viewpoint of further improving the fixability and storage stability, the polyester content is preferably 90% by mass or more, more preferably 95% by mass or more, still more preferably 98% by mass, among the resins constituting the polyester resin particles (A). % Or more, and 100% by mass or less, more preferably 100% by mass.
The content of the polyester resin particles (A) contained in the aqueous dispersion (I) is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 15% by mass in the aqueous dispersion (I). And more preferably 50% by mass or less, more preferably 45% by mass or less, still more preferably 40% by mass or less.

<Polyurethane resin particles>
The polyurethane resin particles contain polyurethane.
The polyurethane resin particles are preferably obtained as a dispersion liquid of polyurethane resin particles by dispersing a resin containing polyurethane in an aqueous medium. That is, those used as a dispersion liquid of polyurethane resin particles (hereinafter, also referred to as "dispersion liquid (Ib1)" meaning a dispersion liquid of polyurethane resin particles which is a raw material of the aqueous dispersion liquid (I)) are preferable.
Polyurethane is obtained, for example, by reacting an active hydrogen compound component having two or more active hydrogen atoms with a polyisocyanate component.

(Polyisocyanate component)
As the polyisocyanate component, diisocyanate is preferable. Examples of the diisocyanate include linear or branched chain aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, and modified products of these diisocyanates (carbodiimide, uretdione, uretoimine-containing modified products, etc.).
Examples of the linear or branched chain aliphatic diisocyanate include tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, and lysine diisocyanate.
Examples of the alicyclic diisocyanate include 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate.
Examples of the aromatic diisocyanate include tolylene diisocyanate, phenylene diisocyanate, and diphenylmethane diisocyanate.

(Active hydrogen compound component)
As the active hydrogen compound component, a polyol is preferable.
Examples of the polyol include a low molecular weight polyol and a high molecular weight polyol. Here, "low molecular weight" means that the molecular weight is less than 500, and "high molecular weight" means that the molecular weight is 500 or more.
As the low molecular weight polyol, a low molecular weight diol is preferable.
Examples of the low molecular weight diol include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, and 1,6-hexane. Examples thereof include chain aliphatic diols such as diols, heptane diols, octane diols, nonane diols, decane diols and dodecane diols, alicyclic diols such as cyclohexane diols and hydrogenated xylylene glycols, and aromatic diols such as xylylene glycols. ..

Examples of the high molecular weight polyol include polycarbonate polyol, polyester polyol, and polyether polyol. Of these, polyether polyols are more preferred.

Examples of the polycarbonate polyol include a polycarbonate polyol obtained by a transesterification reaction between a carbonate compound and a diol.
Examples of the carbonate compound include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate, and diethylene carbonate.

The polyester polyol can be obtained by condensing a low molecular weight diol and a dicarboxylic acid.
The low molecular weight diol is the same as the above-mentioned example, and is preferably ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, or 1,4-butanediol.
Examples of the dicarboxylic acid include aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid and brassic acid, and aromatic acids such as isophthalic acid, terephthalic acid and naphthalenedicarboxylic acid. Dicarboxylic acid can be mentioned.

Examples of the polyether polyol include ring-opening polymers of cyclic ether compounds such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, tetrahydrofuran and epichlorohydrin.
Examples of the polyether polyol include polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

From the viewpoint of stable dispersion in an aqueous medium, it is preferable to introduce an anionic hydrophilic group or the like into polyurethane.
For example, a stable aqueous dispersion can be obtained by reacting a dialkanolcarboxylic acid such as dimethylolacetic acid or dimethylolpropionic acid with a polyisocyanate component of polyurethane and neutralizing these carboxy groups with a neutralizing agent.
Examples of the neutralizing agent include alkylamines such as butylamine and triethylamine, alkanolamines such as monoethanolamine, diethanolamine and triethanolamine, and inorganic basic compounds such as morpholine, ammonia and sodium hydroxide.
The molecular weight of the reaction product of the active hydrogen compound component and the polyisocyanate component may be further increased by using a chain extender, if necessary. Examples of the chain extender include polyols and polyamines. Examples of the reaction terminator include monoalcohol and monoamine.

Polyurethane is obtained by reacting an active hydrogen compound component with a polyisocyanate component.
Polyurethane may be further reacted with a dialkanolcarboxylic acid in addition to the active hydrogen compound component and the polyisocyanate component. Dispersibility in an aqueous solvent can be enhanced by neutralizing the carboxy group in the polyurethane with a neutralizing agent and dispersing it in water.
More specifically, the synthesis of polyurethane can be carried out by reacting an active hydrogen compound component, a polyisocyanate component, and, if necessary, a dialkanolcarboxylic acid.
Examples of the solvent used for the reaction between the active hydrogen compound component and the polyisocyanate component include acetone, methyl ethyl ketone, tetrahydrofuran, dioxane, ethyl acetate, toluene and xylene.
In the above reaction, a chain extender or a reaction terminator may be used in combination, if necessary.
Further, polyurethane is reacted by a multi-step method to synthesize a urethane prepolymer, and then the prepolymer is mixed with water while being neutralized with a neutralizing agent to carry out a water elongation reaction, and at the same time dispersed in an aqueous medium. May be produced. In this case, the viscosity can be easily adjusted and the solvent can be distilled off, which is suitable for production. In this way, polyurethane resin particles having an average particle size of 0.01 to 1 μm can be obtained in the form of a dispersion liquid (Ib1).
The dispersion liquid (Ib1) of the polyurethane resin particles may contain a dispersant such as a surfactant, if necessary.

The solid content concentration of the dispersion liquid (Ib1) of the polyurethane resin particles is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 20 from the viewpoint of obtaining excellent adhesion to various resin recording media. It is mass% or more, more preferably 25% by mass or more, and preferably 50% by mass or less, more preferably 45% by mass or less, still more preferably 40% by mass or less, still more preferably 35% by mass or less.

Commercially available products of the dispersion liquid (Ib1) of polyurethane resin particles include, for example, "WBR" series polyether polyurethane "WBR-016U", polycarbonate polyurethane "WBR-2101", and polyester polyurethane "WBR-2122C" ( Taisei Fine Chemical Co., Ltd.), "Superflex" series polyester / polyether polyurethane "150", "170", polyester polyurethane "210", "500M", "820", polyether polyurethane "870" (The above is manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Polyurethane "UWS-145" of the "Ucoat" series, Polyurethane "UX-485" of the polycarbonate series, Polyurethane "UA-200" of the "Permarin" series. , Polyurethane-based polyurethane "UA-368T" (all manufactured by Sanyo Kasei Kogyo Co., Ltd.) can be mentioned.

The content of polyurethane is preferably 90% by mass or more, more preferably 95% by mass or more, still more preferably 98% by mass or more in the resin constituting the polyurethane resin particles from the viewpoint of further improving fixability and storage stability. Yes, and less than or equal to 100% by weight, and even more preferably 100% by weight.
The content of the polyurethane resin particles contained in the aqueous dispersion (I) is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, still more preferably 1. It is 5% by mass or more, and preferably 30% by mass or less, more preferably 25% by mass or less, still more preferably 20% by mass or less.

<Modified polyolefin resin particles>
The modified polyolefin resin particles contain modified polyolefin.
The modified polyolefin resin particles mean a dispersion liquid of modified polyolefin resin particles (hereinafter, a dispersion liquid of modified polyolefin resin particles which is a raw material of the aqueous dispersion liquid (I)) by dispersing a resin containing the modified polyolefin in an aqueous medium. (Also referred to as “dispersion liquid (Ib2)”) is preferable. That is, those used as an aqueous dispersion of modified polyolefin resin particles are preferable.
The modified polyolefin is, for example, a homopolymer of an olefin or a modified product of a copolymer of two or more kinds of olefins. Examples of the modified polyolefin include modified products such as polypropylene, a propylene-α-olefin copolymer, and an ethylene-vinyl acetate copolymer. As the copolymer, either a block copolymer or a random copolymer can be used.
The number of carbon atoms of the α-olefin in the propylene-α-olefin copolymer is preferably 4 or more, and preferably 15 or less, more preferably 10 or less, still more preferably 8 or less.
Examples of the α-olefin include ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene and 4-methyl-1-pentene.
Among these, polypropylene or a propylene-α-olefin copolymer is used from the viewpoint of further improving fixability and storage stability.

The weight average molecular weight of the modified polyolefin is preferably 10,000 or more, more preferably 15,000 or more, still more preferably 50,000 or more, and preferably 200, from the viewpoint of further improving fixability and storage stability. It is 000 or less, more preferably 150,000 or less. The weight average molecular weight is a value measured by gel permeation chromatography (standard substance: polystyrene).

Examples of the modified polyolefin include a polyolefin modified with a polarity-imparting agent containing chlorine (hereinafter, also simply referred to as “chlorinated polyolefin”) and a polyolefin modified with an unsaturated carboxylic acid compound (hereinafter, simply “acid-modified polyolefin”). , And hydroxy-modified polyolefin (hereinafter, also simply referred to as “hydroxy-modified polyolefin”). Among these, chlorinated polyolefin is preferable.

Chlorinated polyolefins are obtained by the chlorination reaction of polyolefins.
The chlorination reaction can be carried out by a usual reaction method. For example, the above-mentioned polyolefin is dispersed or dissolved in water or a medium such as carbon tetrachloride or chloroform, and chlorine gas in a temperature range of 50 ° C. or higher and 120 ° C. or lower under pressure or normal pressure in the presence of a catalyst or irradiation with ultraviolet rays. It is done by blowing in.

The chlorine-based solvent used in the production of the obtained chlorinated polyolefin is usually distilled off by reducing pressure or the like, or replaced with an organic solvent.

The chlorine content of the chlorinated polyolefin is preferably 10% by mass or more, more preferably 15% by mass or more, still more preferably 20% by mass or more, still more preferably 25% by mass, from the viewpoint of further improving the fixability and storage stability. The above, and preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 35% by mass or less. In the present specification, the chlorine content is a value measured according to JIS-K7229.

The acid-modified polyolefin is a polyolefin modified with an unsaturated carboxylic acid compound.
Examples of unsaturated carboxylic acid compounds include unsaturated carboxylic acids, unsaturated carboxylic acid derivatives, and unsaturated carboxylic acid anhydrides. The unsaturated carboxylic acid means an unsaturated compound containing a carboxy group. The unsaturated carboxylic acid derivative means a mono or diester, amide, imide or the like of the compound. Unsaturated carboxylic acid anhydride means an anhydride of the compound. Of these, unsaturated carboxylic acids are preferred.
Examples of unsaturated carboxylic acid compounds include fumaric acid, maleic acid, itaconic acid, citraconic acid, aconitic acid, nadic acid and their anhydrides, methyl fumarate, ethyl fumarate, propyl fumarate, butyl fumarate, and the like. Dimethyl fumarate, diethyl fumarate, dipropyl fumarate, dibutyl fumarate, methyl maleate, ethyl maleate, propyl maleate, butyl maleate, dimethyl maleate, diethyl maleate, dipropyl maleate, dibutyl maleate, maleimide, N-phenylmaleimide, (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, cyclohexyl (meth) acrylate, lauryl (meth) acrylate, benzyl (meth) acrylate, N, N-dimethylaminoethyl (meth) ) Acrylate can be mentioned. Among these, maleic acid or acrylic acid is preferable.
Examples of the acid modification method include a method in which an unsaturated carboxylic acid compound and, if necessary, a specific (meth) acrylic acid ester are used in combination as a monomer, and graft copolymerization is performed to modify the polyolefin.
The graft amount of the unsaturated carboxylic acid compound is preferably 1% by mass or more, more preferably 5% by mass or more, still more preferably 8% by mass or more, and preferably 20% by mass or more, based on the polyolefin before acid modification. It is mass% or less, more preferably 15 mass% or less.

The conditions for denaturation can be carried out according to a method such as a melting method or a solution method.
In the case of the melting method, the polyolefin is heated and melted (heated and melted) in the presence of a radical reaction initiator to react.
In the case of the solution method, after dissolving the polyolefin in an organic solvent, the reaction is carried out by heating and stirring in the presence of a radical reaction initiator. Examples of the organic solvent include aromatic solvents such as toluene and xylene. The temperature during the reaction is preferably 100 ° C. or higher and 180 ° C. or lower.
Examples of the radical reaction initiator used in the melting method and the solution method include organic peroxide compounds and azonitriles.

As the acid-modified polyolefin, one that has been further chlorinated can also be used. The chlorination reaction method and the chlorine content are the same as in the above-mentioned preferable examples.

Moreover, as a method of hydroxy denaturation, a method of introducing a hydroxy group at the terminal of a polyolefin by polymerizing an olefin using a radical initiator or a terminator having a hydroxyl group can be mentioned.
In addition, as a modified polyolefin by introducing a hydroxyl group or an amino group, as described in Patent No. 2768475, the polyolefin and an ethylenically unsaturated compound having a hydroxyl group or an amino group are brought into contact with each other in the presence of a radical initiator. There is a way to get it.

(Manufacturing method of modified polyolefin resin particles)
The modified polyolefin resin particles are preferably produced by a method in which the resin containing the modified polyolefin described above is dispersed in an aqueous medium to obtain the modified polyolefin resin particles as a dispersion liquid (Ib2). Further, modified polyolefin resin particles commercially available as an aqueous product or an aqueous dispersion can also be used.

As a method for producing the modified polyolefin resin particles, the same method as the polyester resin particles (A) described above is preferable as an example. For example, a method of adding a resin containing a modified polyolefin to an aqueous medium and performing a dispersion treatment by a disperser or the like, a method of gradually adding an aqueous medium to a resin containing a modified polyolefin and emulsifying the phase inversion and the like can be mentioned. As a phase inversion emulsification method, it is preferable to first dissolve a resin containing a modified polyolefin in an organic solvent, then add an aqueous medium to this solution to invert the phase, and then remove the organic solvent.

As the organic solvent, from the viewpoint of dissolving the resin containing the modified polyolefin, a ketone solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and diethyl ketone; an ether solvent such as dibutyl ether, tetrahydrofuran, and dioxane; ethyl acetate, acetate. Examples thereof include acetate-based solvents such as isopropyl; alkyl halide-based solvents such as dichloromethane and chloroform; and hydrocarbon-based solvents such as toluene. From the viewpoint of easy removal from the mixed solution after the addition of the aqueous medium, at least one selected from a ketone solvent and an acetic acid ester solvent is preferable.
Further, from the viewpoint of improving the affinity of the resin containing the modified polyolefin for the aqueous medium and improving the dispersion stability of the dispersion liquid (Ib2), the above-mentioned basic compound, surfactant and the like may be used. ..
In addition, preferable aspects such as dispersion conditions are the same as the above-mentioned method for producing polyester resin particles (A).

The solid content concentration of the dispersion liquid (Ib2) of the modified polyolefin resin particles is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 10% by mass or more, from the viewpoint of obtaining excellent adhesion to various resin recording media. It is 20% by mass or more, more preferably 25% by mass or more, and preferably 50% by mass or less, more preferably 45% by mass or less, still more preferably 40% by mass or less, still more preferably 35% by mass or less.

Commercially available products of the dispersion liquid (Ib2) of the modified polyolefin resin particles include, for example, "E-415", "E-480T", "E-604", and "E-723" of the "Supercron" series (above). , Nippon Paper Industries, Ltd.), "Hardlen" series, "EH-801", "NA-3002", "NZ-1001", "NZ-1004", "EW-5303", "EZ-1001" ( Above, "AE-202", "AE-301" (above, manufactured by Nippon Paper Industries Co., Ltd.) of "Auroren" series, "BW-5550" (Mitsubishi) of "Aptlock" series (Chemical Co., Ltd.), "Arrow Base" series, "SA-1200", "SB-1200", "SB-1010", "SE-1200" (all manufactured by Unitika Co., Ltd.) and the like.

The modified polyolefin resin particles may contain a resin other than the modified polyolefin, for example, a resin such as a styrene-acrylic copolymer, an epoxy resin, polycarbonate, or polyurethane, as long as the effects of the present invention are not impaired.

The content of the modified polyolefin in the resin constituting the modified polyolefin resin particles is preferably 70% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass, from the viewpoint of further improving the fixability and storage stability. The above is more preferably 95% by mass or more, and 100% by mass or less.

The content of the modified polyolefin resin particles in the aqueous dispersion (I) is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, still more preferably, from the viewpoint of further improving the fixability and storage stability. Is 1.5% by mass or more, and preferably 30% by mass or less, more preferably 25% by mass or less, still more preferably 20% by mass or less.

<Organic solvent>
The organic solvent blended in the aqueous dispersion (I) has a boiling point of 100 ° C. or higher and 250 ° C. or lower from the viewpoint of obtaining the aqueous dispersion (I) having excellent fixability and storage stability.
The boiling point of the organic solvent is preferably 120 ° C. or higher, more preferably 150 ° C. or higher, further preferably 180 ° C. or higher, and preferably 230 ° C. or lower, more preferably from the viewpoint of further improving fixability and storage stability. Is 210 ° C. or lower, more preferably 200 ° C. or lower.
"Boiling point" means the boiling point at 760 mmHg.
As the organic solvent, an aqueous organic solvent is preferable. The aqueous organic solvent is an organic solvent that dissolves in 100 parts by mass or more of water at 25 ° C.
Examples of the organic solvent include alcohol solvents such as propylene glycol (boiling point 187 ° C.), 1,2-butanediol (boiling point 190 ° C.), and 1,3-butanediol (boiling point 207 ° C.); diethylene glycol monomethyl ether (boiling point 193). ℃), ethylene glycol monoethyl ether (boiling point 135 ℃), diethylene glycol monopropyl ether (boiling point 151 ℃), diethylene glycol monoisopropyl ether (boiling point 141 ℃), diethylene glycol monoisopropylmethyl ether (boiling point 179 ℃), diethylene glycol monobutyl ether (boiling point) 230 ° C.), diethylene glycol monoisobutyl ether (boiling point 220 ° C.), dipropylene glycol dimethyl ether (boiling point 171 ° C.) and other alkylene glycol-based solvents can be mentioned. Among these, an alkylene glycol solvent is preferable.
In the aqueous dispersion (I), the content of the organic solvent is preferably 1% by mass or more, more preferably 2% by mass or more, still more preferably 4% by mass or more in the aqueous dispersion (I), and It is preferably 20% by mass or less, more preferably 15% by mass or less, still more preferably 10% by mass or less.
In the aqueous dispersion (I), the content of the organic solvent is preferably 1% by mass or more, more preferably 2% by mass or more, still more preferably 4% by mass or more, based on the total amount of water and the organic solvent. Yes, and preferably 30% by mass or less, more preferably 20% by mass or less, still more preferably 15% by mass or less.

As the organic solvent, other organic solvents other than the organic solvent having a boiling point of 100 ° C. or higher and 250 ° C. or lower can be used in combination. The content of the organic solvent having a boiling point of more than 250 ° C. is preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 1% by mass or less, and preferably 0% by mass in the aqueous dispersion. Is.
Examples of the organic solvent having a boiling point of more than 250 ° C. include triethylene glucol monobutyl ether and glycerin.

<Water>
As the water used for the aqueous dispersion (I), pure water such as deionized water, ion-exchanged water and distilled water, and ultrapure water are preferable.
The content of water in the aqueous dispersion (I) is preferably 40% by mass or more, more preferably 50% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass or less.

[Manufacturing method of aqueous dispersion (I)]
The aqueous dispersion (I) is, for example, at least one selected from the dispersion (Ia) of the polyester resin particles (A), the dispersion (Ib1) of the urethane resin particles, and the dispersion (Ib2) of the modified polyolefin resin particles. And the process of mixing with the dispersion
It is obtained by a production method including a step of mixing the mixed dispersion liquid and an organic solvent having a boiling point of 100 ° C. or higher and 250 ° C. or lower.
After the step of mixing the organic solvent, coarse particles may be removed by filtering with a wire mesh or the like.

The aqueous dispersion (I) may contain a pigment used as a base material such as a white pigment.
However, the aqueous dispersion (I) preferably does not contain a colorant. The colorant is a colorant having a maximum absorption wavelength in the visible light region.
The content of the colorant is preferably 3% by mass or less, more preferably 1% by mass or less, still more preferably 0.1% by mass or less, and preferably 0% by mass in the aqueous dispersion.

The aqueous dispersion (I) is used for forming a liquid developer receiving layer.
The receiving layer is a layer provided to enhance the fixability of the toner particles of the liquid developer. For example, the toner receiving layer is formed by applying an aqueous dispersion liquid onto a resin recording medium. More specifically, the aqueous dispersion is used in the method for producing a resin recording medium with a liquid developer receiving layer, which will be described later.

[Manufacturing method of resin recording medium]
A method for producing a resin recording medium with a liquid developer receiving layer includes, for example, a step of forming a toner receiving layer on a resin recording medium using an aqueous dispersion.
As the resin recording medium, it can be suitably used for non-water-absorbent or low-water-absorbent resin recording media such as polyethylene terephthalate (PET), polyvinyl chloride (PVC), polypropylene (PP), and nylon (NY). Suitable for use in commercial or industrial printing. As the resin recording medium, a corona-treated base material may be used.
“Non-water absorption or low water absorption” means that the amount of water absorption of the recording medium at a contact time of 100 msec between the recording medium and water is 0 g / m ² or more and 10 g / m ² or less.

The resin recording medium is preferably at least one selected from a polyethylene terephthalate film, a polyvinyl chloride film, a polypropylene film and a nylon film, and more preferably a polyethylene terephthalate film and a polypropylene film.
Examples of commercially available films include polyethylene terephthalate "Lumilar T60" (manufactured by Toray Co., Ltd.), polyvinyl chloride "PVC80BP" (manufactured by Lintec Co., Ltd.), and polyvinyl chloride "DGS-210WH" (manufactured by Roland DG Co., Ltd.). ), Transparent vinyl chloride "RE-137" (manufactured by Mimaki Engineering Co., Ltd.), polyethylene "Kainas KEE70CA" (manufactured by Lintec Co., Ltd.), polypropylene "YUPO SG90 PAT1" (manufactured by Lintec Co., Ltd.), polypropylene "FOR", "FOA" (All manufactured by Futamura Chemical Co., Ltd.), nylon "Bonil RX" (manufactured by Kojin Film & Chemicals Co., Ltd.), and nylon "Emblem ONBC" (manufactured by Unitica Co., Ltd.).

The method for forming the toner receiving layer using the aqueous dispersion (I) is not particularly limited, but a known coating method can be used.
Examples of the coating machine used for coating include a bar coater, an air doctor coater, a blade coater, a reverse roll coater, a gravure coater, a kiss roll coater, a cast coater, and a curtain coater. Among these, a bar coater is preferable.
Further, as a method of forming the toner receiving layer in the same manner as the coating method, various known printing methods such as a gravure printing method (concave plate), a flexographic printing method (convex plate), an inkjet printing method, and an electrophotographic method are used. , The toner receiving layer may be formed.

[Image formation method]
The image forming method of the present invention is, for example,
It has a step of forming an image on a toner receiving layer using a liquid developer containing toner particles.
The liquid developer contains, for example, toner particles and an insulating liquid, and the toner particles are dispersed in the insulating liquid.
As the toner particles, for example, toner particles containing a polyester resin are used.
The insulating liquid means a liquid having a conductivity of ^{1.0 × 10 -10 s / m or less.} Examples of the insulating liquid include aliphatic hydrocarbons such as liquid paraffin and isoparaffin, alicyclic hydrocarbons, aromatic hydrocarbons, hydrocarbon solvents such as halogenated hydrocarbons, polysiloxane, and vegetable oils.
Image formation is performed by a liquid-developing electrophotographic method using a known liquid-developing printing machine. Examples of commercially available liquid developing type printing machines include "Indigo Press 3500", "Indigo Press 4500", "EPRINT1000" (all manufactured by Hewlett-Packard Co., Ltd.), and "CT-5085" (manufactured by Ricoh Japan Ltd.). Be done.

Hereinafter, the present invention will be described in more detail with reference to Examples and the like. In the following examples and the like, each physical property was measured by the following method.

[Measuring method]
[Acid value of resin]
Measured according to JIS K0070. However, the measurement solvent was a mixed solvent of acetone and toluene [acetone: toluene = 1: 1 (volume ratio)].

[Resin softening point]
Using a flow tester "CFT-500D" (manufactured by Shimadzu Corporation), while heating a 1 g sample at a heating rate of 6 ° C./min, a load of 1.96 MPa was applied by a plunger, and the diameter was 1 mm and the length was 1 mm. Extruded from the nozzle of. The amount of plunger drop of the flow tester was plotted against the temperature, and the temperature at which half of the sample flowed out was used as the softening point.

[Resin glass transition temperature]
Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), weigh 0.01 to 0.02 g of a sample into an aluminum pan, raise the temperature to 200 ° C, and lower the temperature from that temperature. A sample for measurement was prepared by cooling to 0 ° C. at a speed of 10 ° C./min. Then, the temperature was raised at a temperature rising rate of 10 ° C./min, and the amount of heat was measured. Of the observed heat absorption peaks, the peak temperature with the largest peak area is defined as the maximum heat absorption peak temperature, the extension of the baseline below the maximum heat absorption peak temperature, and the maximum slope from the rising part of the peak to the peak peak. The temperature at the intersection with the tangent line indicating the above was defined as the glass transition temperature.

[Volume average particle size of resin particles ( _DV )]
(1) Measuring device: Zeta potential / particle size measuring system "ELSZ-2" (manufactured by Otsuka Electronics Co., Ltd.)
(2) Measurement conditions: Cumulant analysis method. A dispersion diluted with water so that the concentration of the particles to be measured is about 5 × 10 ^-3 % by mass is placed in a measurement cell, the temperature is 25 ° C., the angle between the incident light and the detector is 90 °, and the number of integrations is 100 times. , The refractive index of water (1.333) was input as the refractive index of the dispersion solvent and measured.

[Concentration of solid content of dispersion of resin particles]
Using an infrared moisture meter "FD-230" (manufactured by Ketsuto Kagaku Kenkyusho Co., Ltd.), 5 g of the measurement sample is dried at a drying temperature of 150 ° C. and measurement mode 96 (monitoring time 2.5 minutes / fluctuation range 0.05%). The water content (% by mass) of the aqueous dispersion was measured. The solid content concentration was calculated according to the following formula.
Solid content concentration (mass%) = 100-moisture (mass%)

[Example of resin production]
Manufacturing example A1
Production of Resin A-1 Nitrogen-substituted inside a four-necked flask equipped with a nitrogen introduction tube, dehydration tube, stirrer, and thermocouple, and polyoxypropylene of 2,2-bis (4-hydroxyphenyl) propane. 2.2) Add 6160 g of adduct, 2125 g of fumaric acid, 10 g of dibutyltin oxide, and 4 g of 4-tert-butylcatechol, and raise the temperature to 210 ° C. over 5 hours with stirring under a nitrogen atmosphere at 210 ° C. After holding for 2 hours, the pressure in the flask was lowered, and the reaction was carried out at 8.3 kPa until the softening point reached 100 ° C. to obtain a polyester resin A-1. The physical characteristics are shown in Table 1.

Manufacturing example A2
Production of Resin A-2 Nitrogen substitution was performed inside a 10-liter four-necked flask equipped with a thermometer, a stainless stir bar, a dehydration tube equipped with a flow-down condenser, and a nitrogen introduction tube, and 1,2-propanediol 2921 g. , 1114 g of fumaric acid, 4466 g of terephthalic acid, 10 g of dibutyltin oxide, and 4 g of 4-tert-butylcatechol were added, and the temperature was raised to 180 ° C. with stirring in a nitrogen atmosphere, and then raised to 210 ° C. over 5 hours. did. Further, the temperature was raised to 220 ° C., the pressure in the flask was lowered, and the temperature was maintained at 8.3 kPa for 3 hours to obtain resin A-2. The physical characteristics are shown in Table 1.

[Production example of raw material dispersion]
Production Example EM1 to EM2; Production of dispersion (Ia) (dispersion EM-1 to EM-2)
Put the resin of the type and amount shown in Table 2 into a 2L four-necked flask equipped with a nitrogen introduction pipe, a reflux condenser, a stirrer "Three One Motor BL300" (manufactured by Shinto Kagaku Co., Ltd.) and a thermocouple. , Was mixed with 200 g of methyl ethyl ketone at 30 ° C. and dissolved. Then, the amount shown in the table was added, and the mixture was stirred for 30 minutes, and then ion-exchanged water was added dropwise at a rate of 20 mL / min while stirring at 30 ° C., and the temperature was raised to 60 ° C. Then, at 60 ° C., methyl ethyl ketone was distilled off while gradually reducing the pressure from 80 kPa to 30 kPa, and a part of water was further removed. After cooling to 25 ° C., the mixture was filtered through a 150 mesh wire mesh, and the solid content concentration was adjusted to 40% by mass with ion-exchanged water to obtain dispersion liquids EM-1 to EM-2 of polyester resin particles.

[Manufacturing of aqueous dispersion (I)]
Example 1
In a four-necked flask equipped with a reflux condenser, a stirrer, and a thermocouple, 304 g of a dispersion liquid EM-1 of polyester resin particles and a dispersion liquid "WBR-016U" of polyurethane resin particles (manufactured by Taisei Fine Chemical Co., Ltd., solid) 101 g of a particle concentration (30% by mass) was added and mixed. Then, the temperature was raised to 65 ° C. with stirring, and a part of water was removed while gradually reducing the pressure from 80 kPa to 30 kPa at 65 ° C. to bring the solid content concentration to 41% by mass. Next, after cooling to 25 ° C., 30 g of diethylene glycol monomethyl ether was added with stirring, mixed for 60 minutes, and filtered through a 150 mesh wire mesh to obtain an aqueous dispersion liquid 1. The composition of the aqueous dispersion 1 is shown in Table 1.

Examples 2-8, Comparative Examples 1-3
Aqueous dispersions (I) 2 to 8,51 to 53 were obtained in the same manner as in Example 1 except that the raw material dispersions and aqueous organic solvents of the types and blending amounts shown in Table 3 were used. The composition of each aqueous dispersion is shown in Table 1.

[Evaluation, production of resin recording medium, and image formation method]
The obtained aqueous dispersion (I) was evaluated by the following method.
[Evaluation of fixability]
The prepared aqueous dispersion (I) was subjected to a biaxially stretched PET film "Lumirror 75T60" (manufactured by Toray Co., Ltd.) and a corona-treated PP film "FOR-15" (manufactured by Futamura Chemical Co., Ltd.) using a bar coater (NO.3). ), Dryed in a dryer at 80 ° C. for 5 minutes, and allowed to stand in an environment room at room temperature of 25 ° C. and relative humidity of 50% for 1 day to prepare a sample (resin recording medium with a receiving layer). ..
Next, the liquid developing type printing machine "IndigoPress 3500" (manufactured by Hulett Packard) is filled with the liquid developing agent described in the following production example, and the aqueous dispersion is applied so ^{that the developing amount is 1.2 g / m 2.} A solid image was printed on each of the coated PET film and PP film to form an image.
After that, a tape "Cellotape (registered trademark) CT15" (manufactured by Nichiban Co., Ltd.) is attached to the printed surface of the sample, the tape is peeled off at a speed of 10 cm / sec at an angle of 90 °, and the remaining area of the coated surface of the sample is visually observed. The evaluation was made in the following five stages. The higher the score, the better the fixability to various films.
<Evaluation criteria>
No peeling or peeling but peeling area less than 5%: 5 points Peeling area 5% or more and less than 25%: 4 points Peeling area 25% or more and less than 50%: 3 points Peeling area 50% or more and less than 75%: 2 points Peeling Area 75% or more: 1 point

[Evaluation of storage stability]
The prepared aqueous dispersion (I) was coated on a biaxially stretched PET film "Lumirror 75T60" (manufactured by Toray Co., Ltd.) with a bar coater (NO.3), dried in a dryer at 80 ° C. for 5 minutes, and dried. A sample (resin recording medium with a receiving layer) was prepared by allowing it to stand for one day in an environment room at room temperature of 25 ° C. and relative humidity of 50%.
This sample was placed on top of each other so that the coated surfaces of the aqueous dispersion (I) were in contact with each other, and a 1 kg weight was placed on the sample and left to stand for one day. Evaluated in.
<Evaluation criteria>
No sticking or sticking but very few: 5 points Sticking area less than 10%: 4 points Sticking area 10% or more and less than 25%: 3 points Sticking area 25% or more and less than 50%: 2 points Sticking area 50% or more: 1 point

[Manufacturing of liquid developer for evaluation]
The liquid developer used in the above evaluation was produced by the following method.
(Manufacturing of resin)
Nitrogen was substituted inside a 10-liter four-necked flask equipped with a thermometer, a stainless stir bar, a dehydration tube equipped with a flow-down condenser, and a nitrogen introduction tube, and 1,2-propanediol 3640 g, terephthalic acid 6360 g, and oxidation were performed. 10 g of dibutyltin was added, and the temperature was raised to 180 ° C. with stirring under a nitrogen atmosphere, and then the temperature was raised to 210 ° C. over 5 hours. Further, the temperature was raised to 220 ° C., the pressure in the flask was lowered, and the temperature was maintained at 8.3 kPa for 2 hours to obtain a resin D-1 for a liquid developer. The softening point was 87 ° C., the glass transition temperature was 47 ° C., and the acid value was 10 mgKOH / g.

(Preparation of toner for liquid developer)
85 parts by mass of the obtained resin D-1, 15 parts by mass of the pigment "ECB-301" (manufactured by Dainichiseika Kogyo Co., Ltd., phthalocyanine blue 15: 3), in advance in a 20 L volume Henschel mixer, a rotation speed of 1500 r After stirring and mixing at / min (peripheral speed 21.6 m / sec) for 3 minutes, a continuous double open roll type kneader "Kneedex" (manufactured by Mitsui Mining Co., Ltd., roll outer diameter: 14 cm, effective roll length: 55 cm) ) Was melt-kneaded. The kneading conditions are as follows: high rotation side roll (front roll) rotation speed 75r / min (peripheral speed 32.4m / min), low rotation side roll (back roll) rotation speed 35r / min (peripheral speed 15.0m / min), The roll gap at the end of the kneaded material supply port side is 0.1 mm, the heating medium temperature and cooling medium temperature in the roll are 90 ° C. on the raw material input side of the high rotation side roll and 85 ° C. on the kneaded material discharge side, and the low rotation side roll. The temperature was 35 ° C. on the raw material input side and 35 ° C. on the kneaded product discharge side. Further, the raw material mixture was kneaded at a supply speed of 10 kg / h to the kneader.
The obtained kneaded product was rolled and cooled with a cooling roll, and then roughly pulverized to about 1 mm using a hammer mill. The obtained coarsely pulverized product was finely pulverized and classified by an air flow jet mill "IDS" (manufactured by Nippon Pneumatic Industries Co., Ltd.) to obtain toner particles having _{a volume medium particle size D 50 of 10 μm.}

(Manufacturing of liquid developer)
Put 105 g of toner for liquid developer, 187.1 g of insulating liquid "Exor D80" (manufactured by ExxonMobil), and 7.9 g of dispersant "Solspers 13940" (manufactured by Lubrizol) in a 2 L polyethylene container. , "TK Robomix" (manufactured by Primix Co., Ltd.) was used to stir for 30 minutes at a rotation speed of 7,000 r / min while cooling with ice to obtain a toner particle dispersion.
Next, the obtained toner particle dispersion liquid was rotated at a rotation speed of a 6-series sand mill "TSG-6" (manufactured by Imex Co., Ltd.) using zirconia beads having a diameter of 0.8 mm at a volume filling rate of 60% by volume. Wet pulverization was performed at 1300 r / min (peripheral speed 4.8 m / sec) for 4 hours. Zirconia beads are removed by wire mesh filtration, diluted to 25% by mass with an insulating liquid, and then have a particle size of 2.2 μm and a viscosity of 24 mPa. A liquid developer having a solid content concentration of 25% by mass was obtained.

In Table 3, each abbreviation has the following meaning.
BU-1: Polyurethane resin particle dispersion "WBR-016U" (manufactured by Taisei Fine Chemicals Co., Ltd., solid content concentration 30% by mass)
BU-2: Polyurethane resin particle dispersion "Superflex 170" (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., solid content concentration 33% by mass)
BO-1: Polyolefin resin particle dispersion "Supercron E-480T" (manufactured by Nippon Paper Industries, Ltd., solid content concentration 30% by mass)
DEGMM: Diethylene glycol monomethyl ether DPGDM: Dipropylene glycol dimethyl ether DEGPM: Diethylene glycol isopropyl methyl ether

As described above, by comparing Examples and Comparative Examples, the polyester resin particles (A) having a glass transition temperature in a predetermined range and at least one resin particle (B) selected from the polyurethane resin particles and the modified polyolefin resin particles Toner particles contained in the liquid developer, which contain an organic solvent having a boiling point of 100 ° C. or higher and 250 ° C. or lower, and the mass ratio of the polyester resin particles (A) to the resin particles (B) is within a predetermined range. It can be understood that the fixability of the resin to the resin recording medium is improved, and the storage stability of the recording medium after coating is also excellent.

Claims (8)

It contains polyester resin particles (A), at least one resin particle (B) selected from polyurethane resin particles and modified polyolefin resin particles, and an organic solvent having a boiling point of 100 ° C. or higher and 250 ° C. or lower.
An aqueous dispersion for forming a liquid developer receiving layer, wherein the mass ratio of the polyester resin particles (A) and the resin particles (B) is 55/45 or more and 95/5 or less. The aqueous dispersion according to claim 1, wherein the polyester resin particles (A) contain polyester having a glass transition temperature of 40 ° C. or higher and 80 ° C. or lower. The aqueous dispersion according to claim 1 or 2, wherein the organic solvent is an alkylene glycol-based organic solvent. The aqueous dispersion according to any one of claims 1 to 3, wherein the total content of the polyester resin particles (A) and the resin particles (B) is 5% by mass or more and 50% by mass or less in the aqueous dispersion. .. Use of the aqueous dispersion according to any one of claims 1 to 4, for forming a receiving layer of a liquid developing toner on a resin recording medium. A resin recording medium with a liquid developer receiving layer, which has a receiving layer formed from the aqueous dispersion according to any one of claims 1 to 4 on a resin recording medium. A method for producing a resin recording medium with a liquid developer receiving layer, which comprises a step of forming a receiving layer on a resin recording medium using the aqueous dispersion according to any one of claims 1 to 4. An image forming method comprising a step of forming an image on a receiving layer of a resin recording medium obtained by the method according to claim 7 using a liquid developer containing toner particles.