JP7067249B2 - Aqueous inkjet ink, recording liquid set and inkjet recording method - Google Patents

Description

The present invention relates to a water-based inkjet ink, a recording liquid set and an inkjet recording method, and more particularly to a water-based inkjet ink, a recording liquid set and an inkjet recording method having excellent substrate versatility, color development and gloss.

Patent Document 1 discloses a technique of encapsulating a pigment with a dispersant using a dispersant that modifies the surface of the pigment in order to impart storage stability, substrate adhesion, and water resistance to the water-based pigment ink. There is.

Further, Patent Document 2 describes a technique for imparting adhesion and high gloss to a highly polar nylon base material and a non-polar polypropylene base material by containing polyester resin particles and a modified polyolefin resin in a water-based ink. Is disclosed.

Patent No. 6031586 Patent No. 5989272

However, even if the ink composition described in Patent Document 2 is excellent in adhesion to a film substrate and gloss, there is a problem in adhesion to a highly polar paper substrate, and the flexibility is further poor. Therefore, the adhesion during folding was insufficient. That is, it was found that there is a limit to the versatility of the base material from the viewpoint of adhesion and the like.

Further, in the paper substrate, the ink permeates the paper substrate due to the influence of the organic solvent added to the ink to prevent the film from repelling, and the coloring material does not stay on the surface of the substrate and the color development density cannot be sufficiently obtained. , And gloss reduction was found to occur.

The technique of Patent Document 1 also did not solve these problems.

Therefore, an object of the present invention is to provide a water-based inkjet ink, a recording liquid set, and an inkjet recording method, which are excellent in versatility of a base material, color development, and gloss.

Further, other problems of the present invention will be clarified by the following description.

The above problems are solved by the following inventions.

1. 1.
A water-based inkjet ink containing at least water-insoluble resin fine particles A containing a pigment, water-insoluble resin fine particles B containing no pigment, an organic solvent C, and water.
The resin fine particles B are composite resins in which a polyolefin-based resin is contained in a polyurethane-based resin.
A water-based inkjet ink containing at least one selected from glycols and diols as the organic solvent C.
2. 2.
The water-based inkjet ink according to 1 above, wherein the water-insoluble resin fine particles B contain a composite resin obtained by emulsifying a polyolefin resin into a polyurethane resin.
3. 3.
The water-based inkjet ink according to 1 or 2, wherein the water-insoluble resin fine particles A are obtained by cross-linking water-insoluble resin fine particles containing a pigment.
4.
A pretreatment liquid containing at least the water-insoluble resin fine particles B containing no pigment, and
A water-based inkjet ink containing at least water-insoluble resin fine particles A containing a pigment, an organic solvent C, and water.
Consists of
The resin fine particles B are composite resins in which a polyolefin-based resin is contained in a polyurethane-based resin.
A recording liquid set containing at least one selected from glycols and diols as the organic solvent C.
5.
The recording liquid set according to 4 above, wherein the water-insoluble resin fine particles B contain a composite resin obtained by emulsifying a polyolefin resin into a polyurethane resin.
6.
The recording liquid set according to 4 or 5, wherein the water-insoluble resin fine particles A are formed by cross-linking water-insoluble resin fine particles containing a pigment.
7.
An inkjet recording method using the recording liquid set according to any one of 4 to 6 above.
The pretreatment liquid is applied onto the base material to form a pretreatment layer, and the pretreatment layer is formed.
Next, an inkjet recording method characterized in that the inkjet ink is applied onto the pretreatment layer by an inkjet method to record an image.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a water-based inkjet ink, a recording liquid set, and an inkjet recording method having excellent substrate versatility, color development, and gloss.

Schematic diagram showing an example of an inkjet recording device

Hereinafter, embodiments for carrying out the present invention will be described in detail.

1. 1. Water-based inkjet ink The water-based inkjet ink of the present invention (hereinafter, also simply referred to as ink) contains water-insoluble resin fine particles A containing a pigment, water-insoluble resin fine particles B containing no pigment, an organic solvent C, and water. Contains at least. Here, the water-insoluble resin fine particles B are composite resins containing a polyolefin-based resin in a polyurethane-based resin, and contain at least one selected from glycols and diols as the organic solvent C.

With such an ink, it is possible to obtain effects excellent in the versatility of the base material, the color development property and the gloss. That is, according to such an ink, excellent adhesion is exhibited not only to a highly polar nylon substrate and a non-polar polypropylene substrate, but also to a highly polar paper substrate. In addition, since the flexibility of the image film can be obtained, the adhesion during the folding process is also excellent. Further, even on a paper substrate, high color density and gloss can be obtained. Furthermore, the image film is also excellent in water resistance and boil resistance.

The reasons for obtaining the above effects are presumed to be as follows.

First, since the water-insoluble resin fine particles B contain a polyolefin-based resin having excellent adhesion to a non-polar substrate and a polyurethane-based resin having excellent adhesion to a polar substrate as a composite resin, one water-insoluble resin. There are two resin portions in the fine particles B. As a result, the wettability is improved with respect to a wide variety of substrates, and a uniform wet film can be formed. When this wet film is dried and formed into an image film, it has a layered structure such as a sea-island structure. It has excellent adhesion and flexibility.

Further, since two resin portions are present in one water-insoluble resin fine particle B, in a highly polar paper substrate, the highly polar portion in the water-insoluble resin fine particles B is the interface between the ink and the paper substrate. Priority is given to. Along with this, the low-polarity portion of the water-insoluble resin fine particles B is oriented toward the upper layer formed on the ink side when viewed from the interface. The highly polar water-insoluble resin fine particles A are repelled by the low-polarity portion existing in the upper layer, and penetration (through-through) into the inside of the paper substrate is suppressed. As a result, the pigment contained in the water-insoluble resin fine particles A stays in the upper layer, and high color development property (high color development density) can be obtained. In addition, the gloss after film formation is improved by suppressing the penetration.

(1) Water-insoluble resin fine particles A
ah. Pigments The pigments constituting the water-insoluble resin fine particles A are not particularly limited, and examples thereof include organic pigments and inorganic pigments. As the pigment, one kind may be used alone, or a plurality of kinds may be used in combination.

The organic pigment is not particularly limited, and examples thereof include condensed polycyclic pigments and azo pigments. Examples of the condensed polycyclic pigment include anthraquinone pigments, quinacridone pigments, indigo pigments, dioxazine pigments, perylene pigments, perinone pigments, isoindolinone pigments, isoindolin pigments, phthalocyanine pigments, and quinophthalones. Examples thereof include based pigments and diketopyrrolopyrrole based pigments. Examples of the azo pigment include dissazo pigments and condensed azo pigments.

Examples of the azo pigment include C.I. I. PY74, C.I. I. PY151, C.I. I. PY154, C.I. I. PY155, C.I. I. PY180, C.I. I. PY213 can be mentioned.

Examples of the quinacridone pigment include C.I. I. PR122, C.I. I. PR192, C.I. I. PR202, C.I. I. PR207, C.I. I. PR209, C.I. I. PV19 and the like can be mentioned.

Examples of the phthalocyanine pigment include C.I. I. PB15: 1, C.I. I. PB15: 2, C.I. I. PB15: 3, C.I. I. PB15: 4, C.I. I. PB15: 5, C.I. I. PB15: 6, C.I. I. PB16, C.I. I. PG7, C.I. I. PG36 and the like can be mentioned.

A functional group such as a hydroxyl group, a carboxy group, a carbamoyl group, a sulfo group, a sulfonamide group, or a phthalimidemethyl group may be introduced and used on the surface of these organic pigments.

The inorganic pigment is not particularly limited, and examples thereof include metal oxides such as carbon black, alumina, and titanium dioxide.

Examples of carbon black include furnace black, thermal black, lamp black, acetylene black, channel black and the like.

These inorganic pigments may be used by treating them with, for example, a known hydrophobic treatment agent such as a titanium coupling agent, a silane coupling agent, or a higher fatty acid metal salt.

The content of the pigment in the ink can be, for example, 1% by mass or more, 2% by mass or more, further 3% by mass or more, and for example, 25% by mass or less, 10% by mass or less, and further 7%. It can be mass% or less.

I. Dispersed resin The water-insoluble resin constituting the water-insoluble resin fine particles A is dried at 105 ° C. for 2 hours, and when the resin reaches a constant amount is dissolved in 100 g of water at 25 ° C., the dissolved amount is 10 g or less. Certain resins can be used. The dissolved amount is preferably 5 g or less, and more preferably 1 g or less. When the resin has an anionic group, the dissolved amount is the dissolution amount when the anionic group is 100% neutralized with sodium hydroxide.

The water-insoluble resin is not particularly limited, and examples thereof include polyester, polyurethane, and vinyl-based polymers, and among them, vinyl-based polymers are preferable. The vinyl-based polymer is obtained, for example, by addition polymerization of one or more vinyl monomers selected from a vinyl compound, a vinylidene compound, and a vinylene compound.

The water-insoluble resin made of a vinyl polymer is preferably a monomer mixture containing an ionic monomer and a hydrophobic monomer. Such a vinyl polymer has a structural unit derived from an ionic monomer and a structural unit derived from a hydrophobic monomer.

Further, the water-insoluble resin made of a vinyl polymer is preferably obtained by copolymerizing a monomer mixture containing an ionic monomer, a hydrophobic monomer and a nonionic monomer. Such a vinyl polymer has a structural unit derived from an ionic monomer, a structural unit derived from a hydrophobic monomer, and a structural unit derived from a nonionic monomer.

The ionic monomer may be either an anionic monomer or a cationic monomer, but is preferably an anionic monomer.

The anionic monomer is not particularly limited, and examples thereof include a carboxylic acid monomer, a sulfonic acid monomer, and a phosphoric acid monomer.

Examples of the carboxylic acid monomer include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, 2-methacryloyloxymethylsuccinic acid and the like.

Examples of the sulfonic acid monomer include styrene sulfonic acid, 2-acrylamide-2-methylpropane sulfonic acid, 3-sulfopropyl (meth) acrylate and the like.

In addition, in this specification, "(meth) acrylate" means acrylate and / or methacrylate.

Examples of the phosphoric acid monomer include vinylphosphonic acid, vinyl phosphate, bis (methacryloxyethyl) phosphate, diphenyl-2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate and the like.

The hydrophobic monomer is not particularly limited, and examples thereof include an alkyl (meth) acrylate, an aromatic group-containing monomer, and a high molecular weight monomer (also referred to as macromer).

The alkyl (meth) acrylate is not particularly limited, but the alkyl group preferably has 1 to 22 carbon atoms, preferably 6 to 18 carbon atoms, and is, for example, methyl (meth) acrylate, ethyl (meth) acrylate, and (iso) propyl. (Meta) acrylate, (iso or tertiary) butyl (meth) acrylate, (iso) amyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (iso) octyl (meth) acrylate, ( Examples thereof include iso) decyl (meth) acrylate, (iso) dodecyl (meth) acrylate, and (iso) stearyl (meth) acrylate.

In addition, in this specification, "(iso or tertiary)" and "(iso)" mean both the case where these groups exist and the case where these groups do not exist, and when these groups do not exist, the normal is used. means

The aromatic group-containing monomer is not particularly limited, but a vinyl monomer having an aromatic group having 6 to 22 carbon atoms, which may or may not have a substituent containing a heteroatom, is preferable, and a styrene-based monomer and an aromatic group are used. Group group-containing (meth) acrylates are more preferred. Examples of the styrene-based monomer include styrene, 2-methylstyrene, divinylbenzene and the like. Examples of the aromatic group-containing (meth) acrylate include benzyl (meth) acrylate and phenoxyethyl (meth) acrylate.

The high molecular weight monomer is a compound having a polymerizable functional group at one end and having a number average molecular weight of 500 to 100,000, preferably 1000 to 10000. The number average molecular weight is measured by a gel chromatography method using chloroform containing 1 mmol / L dodecyldimethylamine as a solvent, using polystyrene as a standard substance.

The polymerizable functional group existing at one end of the high molecular weight monomer is not particularly limited, and examples thereof include an acryloyloxy group and a methacryloyloxy group.

Examples of the high molecular weight monomer include aromatic group-containing monomer-based high molecular weight monomers and silicone-based high molecular weight monomers.

Examples of the aromatic group-containing monomer constituting the aromatic group-containing monomer-based high molecular weight monomer include the above-mentioned aromatic group-containing monomer. The styrene-based high molecular weight monomer using the styrene-based monomer as the aromatic group-containing monomer is, for example, "AS-6 (S)", "AN-6 (S)", "HS-6 (S)" manufactured by Toagosei Co., Ltd. It is commercially available as "etc."

Examples of the silicone-based high molecular weight monomer include organopolysiloxane having a polymerizable functional group at one end, and can be represented by, for example, the following formula.

CH ₂ = CR ¹ -COOC ₃ H _6- [Si (R ² ) ₂ -O] _b -Si (R ² ) ₃

(In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and b is 5 to 60.)

Silicone-based high molecular weight monomers are commercially available, for example, as "Silaplane FM-0711", "Silaplane FM-0721", "Silaplane FM-0725", etc. manufactured by Chisso.

The nonionic monomer is not particularly limited, and examples thereof include polyalkylene glycol (meth) acrylate, alkoxypolyalkylene glycol (meth) acrylate, and phenoxy (ethylene glycol-propylene glycol copolymer) (meth) acrylate.

Examples of the polyalkylene glycol (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and polypropylene glycol (average number of moles of oxyalkylene group added n = 2 to 30) (meth). Examples include acrylate.

Examples of the alkoxypolyalkylene glycol (meth) acrylate include methoxypolyethylene glycol (n = 1 to 30) (meth) acrylate.

Examples of the phenoxy (ethylene glycol-propylene glycol copolymer) (meth) acrylate include phenoxy (ethylene glycol-propylene glycol copolymer) (average number of moles of oxyalkylene group n = 1 to 30, ethylene among oxyalkylene groups). The average number of moles of glycol added n'= 1 to 29) (meth) acrylate and the like can be mentioned.

The nonionic monomer preferably has a hydroxyl group. Examples of the nonionic monomer having a hydroxyl group include "NK ester M-20G", "NK ester M-40G", "NK ester M-90G", "NK ester M-230G", and Nichiyu Co., Ltd. manufactured by Shin-Nakamura Chemical Industry Co., Ltd. "Blemmer PE-90", "Blemmer PE-200", "Blemmer PE-350", "PME-100", "PME-200", "PME-400", etc., "PP-500", "PP" -800, etc., "AP-150", "AP-400", "AP-550", etc., "50PEP-300", "50POEP-800B", "43PAPE-600B", etc. are commercially available.

The ionic monomer, hydrophobic monomer, and nonionic monomer described above can be used alone or in combination of two or more.

The content of each monomer in the monomer mixture or the content of the constituent units derived from each monomer in the water-insoluble resin at the time of synthesizing the water-insoluble resin is preferably as follows. The content referred to here is the content as an unneutralized amount.

The content of the ionic monomer can be, for example, 3% by mass or more, 4% by mass or more, further 5% by mass or more, and for example, 40% by mass or less, 30% by mass or less, and further 25% by mass. It can be less than or equal to%.

The content of the hydrophobic monomer can be, for example, 5% by mass or more, 10% by mass or more, further 40% by mass or more, and for example, 98% by mass or less, 80% by mass or less, and further 70% by mass. It can be less than or equal to%.

The content of the nonionic monomer may be 0% by mass or more, and when the nonionic monomer is used, it can be, for example, 2% by mass or more, 4% by mass or more, further 6% by mass or more, and for example. , 30% by mass or less, 25% by mass or less, and further 20% by mass or less.

The mass ratio [ionic monomer / hydrophobic monomer] between the content of the ionic monomer and the content of the hydrophobic monomer shall be, for example, 0.01 or more, 0.02 or more, and further 0.03 or more. It can be 1.0 or less, 0.7 or less, and even 0.5 or less.

When the content of each monomer constituting the water-insoluble resin (content of the constituent unit derived from each monomer) is within the range exemplified above, the polarity of the water-insoluble resin fine particles A is appropriately increased, and the upper layer of the paper substrate is formed. It becomes easy to be repelled by the low-polarity portion in the water-insoluble resin fine particles B oriented to. As a result, penetration (through-through) into the inside of the paper substrate is further suppressed, and color development and gloss are further improved.

The polymerization method (copolymerization method) for producing the water-insoluble resin described above is not particularly limited, and a known method can be used.

The content of the water-insoluble resin described above in the ink can be, for example, 1.0% by mass or more, 2.0% by mass or more, further 3.0% by mass or more, and for example, for example. It can be 15% by mass or less, 10% by mass or less, and further can be 5.0% by mass or less.

hare. In the coated and crosslinked water-insoluble resin fine particles A, the pigment is contained in the water-insoluble resin. The inclusion of the pigment in the water-insoluble resin may mean that the pigment is coated with the water-insoluble resin. At this time, the entire surface of the pigment does not necessarily have to be covered with the water-insoluble resin, and at least a part of the surface of the pigment may be covered.

The water-insoluble resin fine particles A are preferably encapsulated pigments in which the pigment is included in the water-insoluble resin. This is a polymer emulsion in which a pigment is contained in particles composed of a water-insoluble resin, and the pigment is coated with a water-insoluble resin to form a resin layer on the surface of the pigment and dispersed in water. possible. As described above, the pigment can be encapsulated in the water-insoluble resin.

The water-insoluble resin fine particles A are preferably formed by cross-linking the water-insoluble resin fine particles containing the pigment. This has the effect of making the gloss of the image more uniform.

The cross-linking agent is not particularly limited, and a compound having a plurality of (for example, 2 to 6) functional groups capable of reacting with the reactive group in the polymer constituting the water-insoluble resin can be used. The reactive group in the polymer is not particularly limited, but may be, for example, an ionic group. The ionic group can be derived from the above-mentioned ionic monomer.

The molecular weight of the cross-linking agent is not particularly limited, but can be, for example, 120 or more, further 150 or more, and for example, 2000 or less, 1500 or less, and further 1000 or less.

The functional group of the cross-linking agent is not particularly limited, and examples thereof include a hydroxyl group, an epoxy group, an aldehyde group, an amino group, a carboxy group, an oxazoline group, and an isocyanate group.

The epoxy equivalent (g / eq) of the cross-linking agent having an epoxy group can be, for example, 90 or more, 100 or more, further 110 or more, and 1000 or less, 500 or less, further 300 or less. can. The epoxy equivalent of the cross-linking agent is a value measured by a potentiometric titration method using a potentiometric titration device (“AT-610” manufactured by Kyoto Denshi Kogyo Co., Ltd.) in accordance with JIS K7236.

Examples of the cross-linking agent having two or more epoxy groups in the molecule include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycerin triglycidyl ether, glycerol polyglycidyl ether, and polyglycerol polyglycidyl ether. Examples thereof include polyglycidyl ethers such as trimethylolpropane polyglycidyl ether, sorbitol polyglycidyl ether, pentaerythritol polyglycidyl ether, resorcinol diglycidyl ether, neopentyl glycol diglycidyl ether, and hydrogenated bisphenol A type diglycidyl ether.

The cross-linking agent is commercially available as Denacol EX series manufactured by Nagase ChemteX, Epiol BE manufactured by NOF Corporation, Epiol B series and the like.

The weight ratio of the cross-linking agent (cross-linking agent: water-insoluble resin) used for cross-linking the water-insoluble resin is, for example, 0.3: 100 to 50: 100, 1: 100 to 40: 100, and further 3: 100 to 25 :. It can be 100.

The amount of the cross-linking agent used is, for example, 0.1 mmol or more, 0.3 mmol or more, and further 0.5 mmol or more of the ionic group of the water-insoluble resin in terms of the amount of ionic groups per 1 g of the water-insoluble resin. It can be an amount that reacts, and can be an amount that reacts with 20 mmol or less, 15 mmol or less, 10 mmol or less, 5 mmol or less, and further 1.0 mmol or less of the ionic group.

The water-insoluble particles A cross-linked with the water-insoluble resin can contain, for example, 0.3 mmol or more, further 0.5 mmol or more of ionic groups neutralized with a base per 1 g of the water-insoluble resin, and also. It can contain 1.5 mmol or less.

The cross-linking rate of the water-insoluble resin fine particles A is preferably high, for example, preferably 10 mol% or more, 20 mol% or more, and further preferably 30 mol% or more, from the viewpoint of satisfactorily homogenizing the gloss of the image. .. The upper limit of the cross-linking rate is not particularly limited, but can be, for example, 80 mol% or less, 60 mol% or less, and further 50 mol% or less. The cross-linking rate (mol%) is represented by {(the number of moles of the reactive group of the cross-linking agent) / (the number of moles of the reactive group capable of reacting with the cross-linking agent of the water-insoluble resin fine particles A)} × 100. To.

workman. The average particle size of the other water-insoluble resin fine particles A can be, for example, 40 nm or more, 50 nm or more, further 60 nm or more, and for example, 200 nm or less, 150 nm or less, and further 100 nm or less.

The average particle size of the water-insoluble resin fine particles A is a laser particle analysis system (“ELS-8000” manufactured by Otsuka Electronics Co., Ltd.), a temperature of 25 ° C., an angle of 90 ° between the incident light and the detector, 100 times of integration, and a dispersion solvent. Refractive index = 1.333 (refractive index of water), measured concentration 5 × 10 ^-3 % by mass (converted to solid content concentration), and is a value measured under the measurement conditions (value analyzed by the Cumulant method).

The content of the water-insoluble resin fine particles A in the ink can be, for example, 3.0% by mass or more, 4.0% by mass or more, further 6.0% by mass or more, and for example, 30% by mass. Hereinafter, it can be 20% by mass or less, 15% by mass or less, and further, 9.0% by mass or less.

(2) Water-insoluble resin fine particles B
The water-insoluble resin fine particles B contain a composite resin in which a polyolefin-based resin is contained in a polyurethane-based resin. The "state in which the olefin-based resin is contained in the polyurethane-based resin" can take various aspects, but the olefin-based resin may be dispersed as a plurality of particles in the polyurethane-based resin, and the olefin-based resin may be dispersed. The resin may form a core, and a core-shell structure may be formed in which a polyurethane resin is used as a shell. In addition, the olefin resin may be contained so as to be partially exposed on the surface. Further, in the present specification, the water-insoluble resin fine particles containing the composite resin are also referred to as composite resin particles.

ah. Polyolefin-based resin The polyolefin-based resin may be a modified polyolefin such as a polyolefin modified with an unsaturated carboxylic acid and / or an acid anhydride.

Examples of the polyolefin include polyethylene, polypropylene, an ethylene-propylene copolymer, ethylene and / or propylene, and other comonomer such as 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1 Examples thereof include a random copolymer or a block copolymer (for example, an ethylene-propylene-butene copolymer) with an α-olefin copolymer having 2 or more carbon atoms, preferably 2 to 6 carbon atoms such as nonene. Further, two or more kinds of these other comonomer may be copolymerized. Further, two or more of these polymers can be mixed and used.

As the modified polyolefin, an unsaturated carboxylic acid and / or an acid anhydride and / or a polyolefin modified with a compound having one or more double bonds per molecule is preferably used.

Examples of the unsaturated carboxylic acid and acid anhydride include maleic acid, maleic anhydride, fumaric acid, citraconic acid, citraconic anhydride, mesaconic acid, itaconic acid, itaconic anhydride, aconitic acid, and aconitic acid anhydride. , Β-Unsaturated carboxylic acid and its anhydrides. Each of these may be used alone or in combination of two or more, and when two or more of them are used in combination, the physical characteristics of the coating film are often improved.

Examples of the compound having one or more double bonds per molecule include, as a (meth) acrylic acid-based monomer, methyl (meth) acrylate, ethyl (meth) acrylate, and propyl (meth) acrylate. (Meta) butyl acrylate, (meth) -2-hydroxyethyl acrylate, (meth) -2-hydroxypropyl acrylate, (meth) -4-hydrokibutyl acrylate, cyclohexyl (meth) acrylate, (meth) Tetrahydrofurfuryl acrylate, isobornyl (meth) acrylate, benzyl (meth) acrylate, -2-hydroxybutyl (meth) acrylate, benzyl (meth) acrylate, glycidyl (meth) acrylate, (meth) acrylate , Di (meth) acrylic acid (di) ethylene glycol, di (meth) acrylic acid-1,4-butanjiol, di (meth) acrylic acid-1,6-hexanediol, tri (meth) acrylic Examples thereof include trimethylolpropane acid, glycerin di (meth) acrylate, -2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, and acrylamide. Examples of the styrene-based monomer include styrene, α-methylstyrene, paramethylstyrene, and chloromethylstyrene. Further, examples of the monomer that can be used in combination with this include vinyl-based monomers such as divinylbenzene, vinyl acetate, and vinyl ester of versatic acid.

To modify the polyolefin, once the polyolefin is dissolved in an organic solvent such as toluene or xylene, α, β-unsaturated carboxylic acid and / or its acid anhydride and / or one per molecule in the presence of a radical generator. Radical generation in a compound having the above double bond, or in an autoclave capable of reacting in a molten state capable of raising the temperature to the softening temperature or melting point of the polyolefin or higher, or in a uniaxial or biaxial or more multiaxial extruder. It is carried out using α, β-unsaturated carboxylic acid and / or an acid anhydride thereof and / or a compound having one or more double bonds per molecule in the presence or absence of an agent.

Examples of the radical generator used in the modification reaction include di-tert-butylperphthalate, tert-butylhydroperoxide, dicumyl peroxide, benzoyl peroxide, tert-butylperoxybenzoate and tert-butylperoxy. Examples include radicals such as ethyl hexanoate, tert-butyl peroxypivalate, methyl ethyl ketone peroxide, di-tert-butyl peroxide, and azonitriles such as azobisisobutyronitrile and azobisisopropionitrile. Be done. When graft copolymerization is carried out using these peroxides, the amount of the peroxide is preferably in the range of 0.1 to 50 parts by mass, particularly preferably in the range of 0.5 to 30 parts by mass with respect to the polyolefin. ..

The polyolefin-based resin as the above-mentioned emulsifying raw material may be produced by a known method, and the respective production methods and the degree of modification are not particularly limited.

The polyolefin-based resin used in the present invention preferably has a mass average molecular weight in the range of 20,000 to 100,000. When it is 20000 or more, the cohesive force of the coating film becomes strong, and the physical properties of the coating film such as adhesion and solvent resistance (gasohol resistance) are improved. When it is 100,000 or less, the solubility in an organic solvent is good, and the miniaturization of the particle size of the emulsified dispersion is promoted. The mass average molecular weight is a value measured by gel permeation chromatography (GPC), for example, "RID-6A" manufactured by Shimadzu Corporation (column: "TSK-GEL" manufactured by Toso Co., Ltd., solvent: tetrahydrofuran (THF). ), Column temperature: 40 ° C.), and can be obtained from the calibration curve prepared with a polystyrene standard sample.

Further, in the present invention, a commercially available polyolefin resin can also be used, and as resin fine particles made of a resin having a polyolefin structure, "Aurolen 150A" (polyolefin resin fine particles) manufactured by Nippon Paper Co., Ltd. and "Supercron E" manufactured by Nippon Paper Co., Ltd. can be used. Commercially available products such as "-415" (polyolefin resin fine particles), "Aurolen AE-301" (polyolefin resin fine particles) manufactured by Nippon Paper Co., Ltd., and "Hardlen Na-1001" manufactured by Toyo Kasei Co., Ltd. can be used.

I. Polyurethane-based resin As the polyurethane-based resin, one having a hydrophilic group is used. By introducing a hydrophilic group, the function as an emulsifier for the polyolefin resin can be imparted to the polyurethane resin, and composite resin particles which are emulsified dispersions of the polyolefin resin can be obtained.

Examples of such a hydrophilic group include a carboxy group (-COOH) and a salt thereof, a sulfonic acid group (-SO _3H ) and a salt thereof, and the like. Examples of the salt include alkali metal salts such as sodium salt and potassium salt, and amine salts. Among these, as the hydrophilic group, a carboxy group or a salt thereof is preferable.

The polyurethane-based resin that can be used for the composite resin particles according to the present invention is an aqueous dispersion in which a self-emulsifying polyurethane having a water-soluble functional group is dispersed in the molecule, or a strong mechanical shearing force in combination with a surfactant. It is preferably an aqueous dispersion of forced emulsified polyurethane emulsified under. The polyurethane resin in the aqueous dispersion is obtained by reacting a polyol with an organic polyisocyanate and a hydrophilic group-containing compound.

As the polyol that can be used for preparing the polyurethane-based resin aqueous dispersion, any of polyester polyol, polyether polyol, polycarbonate polyol, and polyolefin-based polyol can be used. Above all, it is preferable to use a polyether polyol or a polycarbonate polyol to have a structure having a carbonate group or an ether group in the urethane resin.

Examples of the polyester polyol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2- and 1,3-propylene glycol, neopentyl glycol, 1,3- and 1,4-butanediol, and 3-methylpentanediol. Low molecular weight polyols such as hexamethylene glycol, 1,8-octanediol, 2-methyl-1,3-propanediol, bisphenol A, hydrogenated bisphenol A, trimethylolpropane, cyclohexanedimethanol, succinic acid, glutaric acid, etc. Examples thereof include condensates with polyvalent carboxylic acids such as adipic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, tetrahydrofuran acid, endomethine tetrahydrofuran acid and hexahydrophthalic acid.

Examples of the polyether polyol include various polyether polyols such as polyethylene glycol, polypropylene glycol, polyethylene polytetramethylene glycol, polypropylene polytetremethylene glycol, and polytetramethylene glycol.

The polycarbonate polyol can be obtained, for example, by reacting a carbonic acid derivative such as diphenyl carbonate, dimethyl carbonate or phosgene with a diol. Suitable examples of such diols are ethylene glycol, diethylene glycol, triethylene glycol, 1,2- and 1,3-propylene glycol, neopentyl glycol, 1,3- and 1,4-butanediol, 3-methyl. Examples thereof include pentandiol, hexamethylene glycol, 1,8-octanediol, 2-methyl-1,3-propanediol, bisphenol A, hydrogenated bisphenol A, trimethylolpropane, and cyclohexanedimethanol. Of these, a polycarbonate polyol using 1,6-hexanediol is preferable from the viewpoint of weather resistance and solvent resistance.

Next, as the organic polyisocyanate compound, those known in the field of the urethane industry can be used, for example, tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polypeptide MDI, xylylene diisocyanate (XDI), tetra. Aromatic isocyanates such as methylxylylene diisocyanate (TMXDI), aliphatic isocyanates such as hexamethylene diisocyanate (HMDI), alicyclic such as isophorone diisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate (hydrogenated MDI, H12MDI). Group isocyanates and the like can be mentioned, and these may be used alone or in combination of two or more. Of these, aliphatic isocyanates and / or alicyclic isocyanates are preferably used. When non-yellowing is required, it is preferable to use HMDI for aliphatic isocyanates, IPDI and H12MDI for alicyclic isocyanates, and XDI and TMXDI for aromatic isocyanates.

Examples of the hydrophilic group-containing compound include compounds having one or more active hydrogen atoms and the above hydrophilic group in the molecule. For example, carboxylic acid-containing compounds such as 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylolbutyric acid, 2,2-dimethylolvaleric acid, and glycine, and their sodium salts and potassium. Derivatives such as salts and amine salts; sulfonic acid-containing compounds such as taurine (that is, aminoethyl sulfonic acid) and ethoxypolyethylene glycol sulfonic acid, and derivatives thereof such as sodium salt, potassium salt and amine salt can be mentioned. ..

When producing a polyurethane resin, a polyol is mixed with an organic polyisocyanate and a hydrophilic group-containing compound and reacted at 30 to 130 ° C. for 30 minutes to 50 hours by a known method to obtain a urethane prepolymer. can get.

The obtained urethane prepolymer is elongated with a chain extender to polymerize, whereby a polyurethane resin having a hydrophilic group can be obtained. As the chain extender, water and / or an amine compound is preferably used. By using water or an amine compound as the chain extender, the isocyanate-terminated prepolymer can be efficiently extended by reacting with free isocyanate in a short time.

As the amine compound as the chain extender, polyamines, for example, aliphatic polyamines such as ethylenediamine and triethylenediamine, aromatic polyamines such as methylylenediamine and toluylenediamine, and polyhydrazino compounds such as hydrazine and adipic acid dihydrazide are used. Be done. The amine compound may contain, together with the above polyamine, a monovalent amine such as dibutylamine, methyl ethyl ketooxime, or the like as a reaction terminator to the extent that it does not significantly inhibit polymerization.

In synthesizing the urethane prepolymer, a solvent that is inert to isocyanate and can dissolve the urethane prepolymer may be used. Examples of these solvents include dioxane, methyl ethyl ketone, dimethylformamide, tetrahydrofuran, N-methyl-2-pyrrolidone, toluene, propylene glycol monomethyl ether acetate and the like. It is preferable that these hydrophilic organic solvents used in the reaction step are finally removed.

Further, in the synthesis of urethane prepolymer, in order to promote the reaction, an amine catalyst (for example, triethylamine, N-ethylmorpholin, triethyldiamine, etc.) and a tin-based catalyst (for example, dibutyltin dilaurate, dioctyltin dilaurate, octyl) are used. A catalyst such as tin acid (such as tin acid) or a titanium-based catalyst (for example, tetrabutyl titanate or the like) may be added.

The molecular weight of the polyurethane resin is preferably as large as possible by introducing a branched structure or an internal crosslinked structure, and the molecular weight is preferably 50,000 to 10,000,000. This is because a coating film having excellent weather resistance and water resistance can be obtained by increasing the molecular weight and making it insoluble in a solvent.

Further, in the present invention, a commercially available polyurethane resin can also be used, and for example, cationic or nonionic polyurethane resin fine particles can be preferably used.

Specific examples of cationic or nonionic polyurethane resin fine particles are given below. Examples of the cationic polyurethane resin fine particles include "Superflex 620" and "Superflex 650" manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. ("Superflex" is a registered trademark of the same company) and "Superflex" manufactured by Sanyo Chemical Industries, Ltd. Examples include "Parmarin UC-20" ("Permarin" is a registered trademark of the same company) and "Parasurf UP-22" manufactured by Ohara Palladium Chemical Industries, Ltd. Examples of the nonionic polyurethane resin fine particles include "Superflex 500M" and "Superflex E-2000" manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.

hare. Composite resin particles The composite resin particles contain a composite resin in which a polyolefin-based resin is contained in a polyurethane-based resin. Preferably, the composite resin particles are obtained by emulsifying a polyolefin-based resin with the above-mentioned polyurethane-based resin having a hydrophilic group to form a composite resin. That is, in the composite resin particles, the polyurethane-based resin exists at the interface between the polyolefin-based resin as the water-insoluble resin and water, which is a continuous phase, and is a water-insoluble resin layer different from the resin that protects the water-insoluble resin. Is functioning as. By forming the composite resin particles obtained by emulsifying the polyolefin resin with the polyurethane resin in this way, it is possible to suppress a decrease in compatibility with the polyurethane resin, an organic solvent, a pigment dispersant, a surfactant and the like. Further, as compared with the case where the polyolefin resin and the polyurethane resin are each emulsified and simply mixed, the physical properties of the coating film can be improved, which is preferable in that the adhesion to the substrate and the storage stability are excellent. The composite resin particles may be obtained by the production method (I) described later, or may be obtained by the production method (II).

The value (PU / PO) of the mass ratio of the polyurethane resin (PU) and the polyolefin resin (PO) in the composite resin is preferably in the range of 40/60 to 95/5, and is preferably 40/60 to 90. It is more preferably in the range of / 10, and most preferably in the range of 60/40 to 80/20. This makes it possible to further improve the versatility (adhesion) of the base material with respect to various base materials including the paper base material.

The total resin concentration of the polyolefin resin and the polyurethane resin in the composite resin particles is not particularly limited, but is usually 5% by mass or more, preferably 10 to 70% by mass.

At the time of emulsification, a surfactant can be used as an emulsifier together with the polyurethane resin. That is, the composite resin particles according to the present invention may further contain a surfactant as an emulsifier. By adding a surfactant, the storage stability of the composite resin particles can be further improved.

As such a surfactant, it is preferable to use either one or both of an anionic surfactant and a nonionic surfactant. It is preferable to blend 1 to 20 parts by mass of these anionic surfactants and nonionic surfactants in total with respect to 100 parts by mass of the total resin. When the blending amount is 20 parts by mass or less, the water resistance and the solvent resistance tend to be excellent.

Further, the value of the compounding mass ratio (X / Y) of the anionic surfactant (X) and the nonionic surfactant (Y) is preferably 100/0 to 50/50. By setting the blending amount of the anionic surfactant in the above range, the emulsifying property and the storage stability can be further improved.

Here, examples of the anionic surfactant include alkyl sulfates, polyoxyethylene alkyl ether sulfates, sulfosuccinates, alphaolefin sulfonates, N-acylamino acid salts, carboxylates, phosphate esters and the like. Be done. Among these, sulfosuccinate and alphaolefin sulfonate are preferable. The type of salt is not particularly limited, but metal salts such as sodium salt, potassium salt and magnesium salt, triethanolamine salt and the like are preferable.

Examples of the nonionic surfactant include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl amine ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, sucrose fatty acid esters and the like. Can be mentioned. Among these, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers and the like are preferable.

In addition, antioxidants, lightfasteners, plasticizers, foaming agents, thickeners, colorants, flame retardants, other aqueous resins, and various fillers can be added to the composite resin particles as long as the performance is not impaired. Examples of the antioxidant include solutions or emulsions of antioxidants such as hindered phenols or semicarbazides. Examples of the light-resistant agent include solutions or emulsions of light-resistant agents such as hindered amine (HALS) -based, benzophenone-based, and benzotriazole-based.

Further, various cross-linking agents such as epoxy-based, carbodiimide-based, oxazolidine-based, blocked isocyanate-based, and isocyanate-based cross-linking agents can be added to the composite resin particles in order to impart higher durability.

An example of a method for producing composite resin particles will be described.

The above-mentioned composite resin particles can be prepared by the following production method (I) or (II).

(I) A method in which a polyolefin resin is emulsified in water with a urethane prepolymer having a hydrophilic group, and then an amine compound as a chain extender or an aqueous solution thereof is added to extend the chain of the urethane prepolymer. ..

(II) A urethane prepolymer having a hydrophilic group is emulsified in water, and an amine compound as a chain extender or an aqueous solution thereof is added to extend the chain of the urethane prepolymer to prepare an aqueous dispersion of a polyurethane resin. Next, a method of emulsifying a polyolefin-based resin with an aqueous dispersion of the polyurethane-based resin.

An embodiment related to the manufacturing method (I) described above will be described. In this method, first, a resin solution obtained by dissolving a polyolefin resin in a solvent and a solution of a urethane prepolymer having a hydrophilic group are mixed, and water is added to the mixture and stirred to emulsify.

Examples of the solvent include organic solvents such as hexane, isohexane, pentane, cyclohexane, methylcyclohexane, heptane, isooctane, methylethylketone, xylene, toluene and benzene, and solvents other than water such as carbon dioxide in a supercritical state. , These can be used alone or in combination of two or more.

The emulsification method may be any of known forced emulsification methods, phase inversion emulsification methods, D-phase emulsification methods, gel emulsification methods, etc. , And combined stirring, sand mills, and multi-screw extruders can be used. Further, at the time of emulsification, the above-mentioned surfactant may be mixed together with the urethane prepolymer.

Next, after diluting the emulsion with water, an amine compound as a chain extender is added to crosslink the residual isocyanate group of the urethane prepolymer with the chain extender to increase the molecular weight of the polyurethane resin. Then, by distilling off the organic solvent, a composite resin particle dispersion containing the polyolefin-based resin inside the polyurethane-based resin (that is, a dispersion in which water-insoluble resin fine particles are dispersed) can be obtained.

In the composite resin particle dispersion thus obtained, when the polyolefin-based resin is a modified polyolefin, the acid component introduced into the polymer may be neutralized by adding a basic substance. By ionizing the same portion by neutralization, the polymer molecule is elongated and the viscosity of the entire system is increased, so that the composite resin particle dispersion can be more stable. Further, in this case, the pH can be adjusted to a desired value depending on the amount of the basic substance added.

The basic substance used is not particularly limited as long as it can neutralize the acid moiety in the polyolefin resin, and for example, methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, and ethaneolamine. , Propanolamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dihexylamine, dioctylamine, dietanolamine, dipropanolamine, N-methyldietanoramine, triethylamine, N, N-dimethylethanolamine, 2- Organic basic substances such as dimethylamino-2-methyl-1-propanol, 2-amine-2-methyl-1-propanol, and morpholine, aqueous ammonia, sodium hydroxide, potassium hydroxide, sodium carbonate, etc. Examples thereof include inorganic basic substances such as sodium hydrogen carbonate, ammonium carbonate and potassium carbonate. When these basic substances are used, one kind may be used, but when two or more kinds of basic substances are used in combination, the object of the present invention is often achieved more effectively. When an amine compound is used as the basic substance, a tertiary amine is used to add the urethane prepolymer before the chain is extended so as not to react with the free isocyanate. On the other hand, when neutralizing the modified polyolefin after chain extension, any of the primary, secondary and tertiary amines can be used.

The amount of the basic substance used for neutralization varies depending on the degree of modification of the modified polyolefin, but is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the modified polyolefin. When the amount of the basic substance is 0.1 parts by mass or more, the pH becomes neutral, and therefore the storage stability of the composite resin particle dispersion is improved. On the other hand, when the amount of the basic substance is 10 parts by mass or less, the storage stability of the composite resin particle dispersion is good, the basicity is not strong, and a large amount of hydrophilic substance is not introduced into the coating film. Water resistance is improved.

An embodiment related to the above-mentioned manufacturing method (II) will be described. In this method, first, water is added to a solution of a urethane prepolymer having a hydrophilic group to emulsify it, and then an amine compound as a chain extender is added to the obtained emulsified solution to leave the urethane prepolymer. The isocyanate group is crosslinked with the chain extender to prepare an aqueous dispersion of a high molecular weight polyurethane resin.

Then, the resin solution obtained by dissolving the polyolefin resin in a solvent and the aqueous dispersion of the polyurethane resin having the hydrophilic group obtained above are mixed, and the polyolefin is obtained from the polyurethane resin having the hydrophilic group. By emulsifying the based resin, diluting it with water, and then distilling off the organic solvent, a composite resin particle dispersion containing the polyolefin resin (that is, water-insoluble resin fine particles are dispersed inside the polyurethane resin. Dispersion) is obtained.

The solvent and emulsification method in the method (II) are the same as those in the method (I). Further, also in the method (II), a surfactant may be mixed with the polyurethane resin when emulsifying the polyolefin resin. Further, in the obtained composite resin particle dispersion, the modified polyolefin may be neutralized with a basic substance, which is the same as the above method (I).

The average particle size of the composite resin particles is not particularly limited, but is preferably in the range of 10 to 500 nm, more preferably in the range of 10 to 300 nm, and further preferably in the range of 10 to 200 nm. The average particle size can be measured by a commercially available particle size measuring device using a dynamic light scattering method, an electrophoresis method, etc., but the measurement by the dynamic light scattering method is simple and the particle size region. Can be measured accurately.

The ink preferably contains the water-insoluble resin fine particles B containing the composite resin in the range of 2 to 10% by mass with respect to the total mass of the ink, and preferably in the range of 3 to 7% by mass. Is more preferable. This has the effect of further improving the density and gloss.

(3) Organic solvent C
The ink contains at least one organic solvent selected from glycols and diols as the organic solvent C. As a result, the effect of the present invention is exhibited more satisfactorily, and the effect of significantly improving the versatility and gloss of the base material can be obtained.

Examples of glycols include ethylene glycol, diethylene glycol, propylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol having 5 or more ethylene oxide groups, dipropylene glycol, tripropylene glycol, and 4 or more propylene oxide groups. Examples thereof include polypropylene glycol, butylene glycol, thiodiglycol and the like.

Examples of diols include 1,3-propanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 1,4-butanediol, and 2-methyl-2,4. -Pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol and the like can be mentioned.

In particular, as organic solvents, ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 1,4-butane Containing at least any one of diol, 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, and 1,6-hexanediol is excellent in storage stability and bronzing inhibitory effect. Is preferable.

The ink may further use other organic solvents other than the glycols and diols described above. As the other organic solvent, a water-soluble organic solvent is preferable, and for example, alcohols, amines, amides, glycol ethers, 1,2-alkanediols having 4 or more carbon atoms and the like are preferably exemplified. can.

As the alcohols, for example, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, secondary butanol, tertiary butanol and the like can be preferably exemplified. Examples of amines include ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenediamine, triethylenetetramine, tetraethylenepentamine, and polyethylene. Immin, pentamethyldiethylenetriamine, tetramethylpropylenediamine and the like can be preferably exemplified.

As the amides, for example, formamide, N, N-dimethylformamide, N, N-dimethylacetamide and the like can be preferably exemplified.

Examples of glycol ethers include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, propylene glycol monopropyl ether, dipropylene glycol monomethyl ether, and tripropylene glycol. A monomethyl ether or the like can be preferably exemplified.

As the 1,2-alkanediols having 4 or more carbon atoms, for example, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-heptanediol and the like are preferably exemplified. can.

When the ink contains two or more kinds of organic solvents, the mass ratio of the glycols and diols to the total mass of the organic solvent is preferably 50% or more.

Further, the content of the organic solvent containing at least one of the organic solvents selected from glycols and diols with respect to the inkjet ink is in the range of 10 to 50% by mass, which is effective in storing stability and suppressing bronzing. It is preferable in that it is excellent in.

(4) Water The water contained in the ink is not particularly limited, and may be ion-exchanged water, distilled water, or pure water.

(5) Other components The ink may contain other components in addition to the components described above. For example, a surfactant can be contained as another component. This makes it possible to improve the ink ejection stability and control the spread (dot diameter) of the droplets that have landed on the recording medium.

The surface tension of the inkjet ink is preferably 35 mN / m or less, and more preferably 30 mN / m or less.

The surfactant contained in the ink is not particularly limited, but when an anionic compound is contained in other constituents of the ink, the ionicity of the surfactant is preferably anionic, nonionic or betaine type.

As the surfactant, preferably, a fluorine-based or silicone-based surfactant having a high ability to reduce static surface tension, and an anionic surfactant such as dioctylsulfosuccinate having a high ability to reduce dynamic surface tension, are compared. Nonionic surfactants such as low molecular weight polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, acetylene glycols, pluronic surfactants, and sorbitan derivatives are preferably used. It is also preferable to use a fluorine-based or silicone-based surfactant in combination with the surfactant having a high ability to reduce the dynamic surface tension.

The content of the surfactant in the inkjet ink is not particularly limited, but is preferably in the range of 0.1 to 5.0% by mass.

In addition to the components described above, ink is known as required for emission stability, printhead and ink cartridge compatibility, storage stability, image storage, and other purposes for improving performance. Various additives such as polysaccharides, viscosity modifiers, specific resistance modifiers, film forming agents, ultraviolet absorbers, antioxidants, anti-fading agents, antifungal agents, anti-rust agents, etc. shall be appropriately selected and used. For example, liquid paraffin, dioctylphthalate, tricresyl phosphate, oil droplet fine particles such as silicone oil, ultraviolet rays described in JP-A-57-74193, JP-A-57-87988 and JP-A-62-261476. Absorbents, JP-A-57-74192, JP-A-57-87989, JP-A-60-72785, JP-A-61-145691, JP-A-1-95091, JP-A-3-13376, etc. The anti-fading agents are described in JP-A-59-429293, JP-A-59-52689, JP-A-62-28069, JP-A-61-242871 and JP-A-4-219266. Fluorescent whitening agents and the like can be mentioned.

(6) Physical Characteristics of Ink The viscosity of the ink is preferably in the range of 1 to 40 mPa · s at 25 ° C., and more preferably in the range of 2 to 10 mPa · s.

(7) Ink manufacturing method The ink manufacturing method consists of a step of emulsifying and dispersing a polyolefin resin and a polyurethane resin to form composite resin particles, and mixing the composite resin particles, an organic solvent, a coloring material and water. It is preferable to include a step.

ah. Step of Forming Composite Resin Particles In this step, as described in the above-mentioned manufacturing method of composite resin particles, preparation is performed by the following manufacturing method (I) or (II).

(I) A method in which a polyolefin resin is emulsified in water with a urethane prepolymer having a hydrophilic group, and then an amine compound as a chain extender or an aqueous solution thereof is added to extend the chain of the urethane prepolymer. ..

(II) A urethane prepolymer having a hydrophilic group is emulsified in water, and an amine compound as a chain extender or an aqueous solution thereof is added to extend the chain of the urethane prepolymer to prepare an aqueous dispersion of a polyurethane resin. Next, a method of emulsifying a polyolefin-based resin with an aqueous dispersion of the polyurethane-based resin.

I. Step of Mixing In this step, the composite resin particles, the organic solvent, the coloring material (pigment) and water obtained in the above step are mixed at room temperature or, if necessary, under heating. After that, it is preferable to filter the obtained mixed solution with a predetermined filter. At this time, a dispersion containing a pigment and a dispersant may be prepared in advance, and the remaining components may be added thereto and mixed.

2. 2. Printed matter The printed matter has a printed layer formed on the base material using the ink described above. The printed matter is a printed matter formed by ejecting ink from an inkjet head, applying the ink, and fixing the ink on the substrate to form a printed matter. Further, the pretreatment liquid may be applied in advance on the substrate to form the pretreatment layer, and the print layer may be formed at the position where the pretreatment layer is applied and fixed.

Further, another functional layer may be formed between the base material and the pretreatment layer, and a non-absorbable film base material or the like may be bonded to the upper layer of the print layer, for example, via a laminate adhesive layer. You may.

The pretreatment liquid may be previously applied onto the substrate in order to improve the image quality formed by the ink when the image is recorded on the substrate by the inkjet method. For example, the pretreatment liquid prevents the color ink forming the image from bleeding into the recording medium, and the ink can be fixed at the position where the pretreatment liquid is applied to the recording medium. Such a pretreatment liquid is not particularly limited, but a sol containing at least one selected from, for example, resin fine particles and a flocculant can be used in a solvent such as water.

(1) Base material The base material is not particularly limited, and may be a paper base material having high polarity and high water absorption, or a base material having low water absorption such as coated paper for gravure or offset printing, or a film. , Plastic boards (soft vinyl chloride, hard vinyl chloride, acrylic plates, polyolefins, etc.), glass, tiles, rubber, and other non-water-absorbent substrates may be used. Since the above-mentioned ink has excellent versatility of the base material, it is suitably used for these various base materials.

Of these, a film is particularly preferable as a base material having low water absorption and a base material having no water absorption (referred to as a non-absorbent film base material in the present invention). By applying the pretreatment liquid for inkjet recording of the present invention to such a substrate, the water-based ink can be sufficiently pinned to form a high-quality image with less bleeding.

Examples of the film include known plastic films. Specific examples of the plastic film include polyester film (PET) such as polyethylene terephthalate, polyethylene film (PE) including high-density polyethylene film and low-density polyethylene film, polypropylene film (PP), and polyamide such as nylon (NYL). System films, polystyrene films, ethylene / vinyl acetate copolymer (EVA) films, polyvinyl chloride (PVC) films, polyvinyl alcohol (PVA) films, polyacrylic acid (PAA) films, polycarbonate films, polyacrylonitrile films, and poly Biodegradable films such as lactic acid films are included. In order to impart gas barrier property, moisture proof property, fragrance retention property, etc., polyvinylidene chloride may be coated on one side or both sides of the film, or a metal oxide may be vapor-deposited. Further, the film may be anti-fog processed. Further, the film may be subjected to corona discharge, ozone treatment, or the like.

The film may be an unstretched film or a stretched film.

Further, the film may be a multi-layered base material in which a layer such as a PVA coat is provided on the surface of an absorbent base material such as paper to make the area to be recorded non-absorbent.

In addition, adhesion can be obtained even when recording is performed on a non-water-absorbent film that has been subjected to anti-fog processing, which is generally difficult to obtain adhesion of recording ink.

Further, when recording is performed on a recording medium having high transparency, the effect that the transparency is not easily impaired can be obtained.

The thickness of the film is not particularly limited, but is preferably less than 250 μm.

3. 3. Inkjet recording method According to the inkjet recording method using the ink described above, images can be recorded on the various substrates described above.

In the inkjet recording method, particularly when the base material is a non-absorbent base material, the surface of the base material may be precoated with a pretreatment liquid in advance, and then an image may be recorded with ink.

The method for applying the pretreatment liquid onto the substrate is not particularly limited, and examples thereof include a roller coating method, a curtain coating method, a spray coating method, and an inkjet method. When the pretreatment liquid contains resin fine particles, for example, the resin fine particles B described above, the amount of the resin fine particles applied is 0.3 g / m ² or more, more preferably 0.8 g, with respect to the base material (recording medium). It is preferably / m ² or more. The preferable amount of the resin fine particles applied can also be applied when applying the pretreatment liquid constituting the recording liquid set described later.

The inkjet head used in the inkjet recording method for applying the ink or the pretreatment liquid onto the substrate is not particularly limited, and may be an on-demand method or a continuous method. The discharge method includes an electric-mechanical conversion method (for example, single cavity type, double cavity type, bender type, piston type, shared mode type, shared wall type, etc.) and an electric-heat conversion method (for example, thermal inkjet). Any discharge method such as type, bubble jet (registered trademark) type, etc. may be used.

In particular, an inkjet head (also referred to as a piezo type inkjet head) using a piezoelectric element as the electric-mechanical conversion element used in the electric-mechanical conversion method is suitable.

Considering that most of the general films are distributed in the form of rolls, it is preferable to use a single-pass inkjet recording method. When a single-pass inkjet recording method is used, a high-definition image can be formed.

In the single-pass inkjet recording method, when a recording medium passes under one inkjet head unit, ink droplets are applied to all the pixels to which dots should be formed by one passage.

It is preferable to use a line head type inkjet head as a means for achieving a single-pass inkjet recording method.

The line head type inkjet head refers to an inkjet head having a length equal to or longer than the width of the print range. As the line head type inkjet head, one head having a width of a print range or more may be used, or a plurality of heads may be combined so as to have a width of a print range or more.

It is also preferable to arrange a plurality of heads side by side so that the nozzles of each head are arranged in a staggered manner to increase the resolution of these heads as a whole.

The transport speed of the recording medium can be set, for example, in the range of 1 to 120 m / min. The faster the transport speed, the faster the image formation speed. According to the present invention, the occurrence of ink bleeding is further suppressed even at a very high linear speed in the range of 50 to 120 m / min, which is applicable to a single-pass inkjet image forming method, and ink adhesion is achieved. A high image can be obtained.

The substrate may be dried after the pretreatment liquid or the ink is applied. The drying can be performed by a known method such as infrared lamp drying, hot air drying, backheat drying, and vacuum drying. From the viewpoint of further increasing the efficiency of drying, it is preferable to dry the substrate by combining two or more of these drying methods.

The following is a preferred example of an inkjet recording method and a recording device.

FIG. 1 is a schematic diagram showing an example of an inkjet recording device (10). However, the present invention is not limited to this, and for example, the first drying portion can be omitted.

The base material (F) unwound from the delivery roller is coated with the pretreatment droplets (4) discharged from the nozzle (3) by the roll coater (2) to form the pretreatment layer (P). At this time, the pretreatment layer (P) is dried by the first drying portion. Next, the ink droplets (7) ejected from the inkjet head (6) are printed on the pretreatment layer (P) to form the ink print layer (R), and the second drying portion (8) is formed. After drying, the ink is wound by the winding roller (9).

4. Recording liquid set and inkjet recording method using the recording liquid set The recording liquid set of the present invention is composed of a pretreatment liquid and an aqueous inkjet ink. Here, the pretreatment liquid contains at least the water-insoluble resin fine particles B containing no pigment. Further, the water-based inkjet ink contains at least water-insoluble resin fine particles A containing a pigment, an organic solvent C, and water.

Further, in the inkjet recording method of the present invention using the recording liquid set, the pretreatment liquid is applied on a substrate to form a pretreatment layer, and then the inkjet ink is applied onto the pretreatment layer by an inkjet method. Is given to record the image.

According to the recording liquid set and the inkjet recording method using the recording liquid set, the effects of excellent substrate versatility, color development and gloss can be obtained. That is, excellent adhesion is exhibited not only to a highly polar nylon base material or a non-polar polypropylene base material, but also to a highly polar paper base material. In addition, since the flexibility of the image film can be obtained, the adhesion during the folding process is also excellent. Further, even on a paper substrate, high color density and gloss can be obtained. Furthermore, the image film is also excellent in water resistance and boil resistance.

The reasons for obtaining the above effects are presumed to be as follows.

First, since the water-insoluble resin fine particles B contained in the pretreatment liquid contain a polyolefin-based resin having excellent adhesion to a non-polar substrate and a polyurethane-based resin having excellent adhesion to a polar substrate as a composite resin. There are two resin portions in one water-insoluble resin fine particle B. As a result, the wettability is improved with respect to a wide variety of substrates, and a uniform wet film can be formed. When this wet film is dried to form a pretreatment layer, a layer like a sea-island structure is formed. Since it forms a structure, it has excellent adhesion and flexibility.

Further, since there are two resin portions in one water-insoluble resin fine particle B, in the highly polar paper base material, the highly polar portion in the water-insoluble resin fine particles B is the pretreatment layer and the paper base material. Priority is given to the interface of. Along with this, the low-polarity portion of the water-insoluble resin fine particles B is oriented toward the upper layer when viewed from the interface. The highly polar water-insoluble resin fine particles A contained in the inkjet ink applied to the pretreatment layer are repelled by the low-polarity portion existing in the upper layer, and penetration (through-through) into the inside of the paper substrate is suppressed. To. As a result, the pigment contained in the water-insoluble resin fine particles A stays in the upper layer, and high color development property (high color development density) can be obtained. In addition, the gloss after film formation is improved by suppressing the penetration.

(1) Recording liquid set a. Pretreatment liquid The pretreatment liquid constituting the recording liquid set is not particularly limited as long as it contains at least water-insoluble resin fine particles B.

As other components that can be contained in the pretreatment liquid that constitutes the recording liquid set, for example, one or more components described in "1. Aqueous inkjet ink" can be appropriately blended. The blending amount of each component constituting the recording liquid set is not particularly limited, but may be, for example, the blending amount described in "1. Aqueous inkjet ink".

The pretreatment liquid constituting the recording liquid set can contain, for example, water-insoluble resin fine particles B and a dispersion medium. As the dispersion medium, at least water can be contained, and the above-mentioned organic solvent C can also be contained.

Further, the pretreatment liquid constituting the recording liquid set may contain a flocculant for agglomerating the water-insoluble resin fine particles A contained in the inkjet ink.

I. The inkjet ink constituting the inkjet ink recording liquid set is not particularly limited as long as it contains water-insoluble resin fine particles A, an organic solvent C, and water.

As other components that can be contained in the inkjet ink constituting the recording liquid set, for example, one or more components described in "1. Aqueous inkjet ink" can be appropriately blended. The blending amount of each component constituting the inkjet ink is not particularly limited, but may be, for example, the blending amount described in "1. Aqueous inkjet ink".

The inkjet ink constituting the recording liquid set may or may not contain the water-insoluble resin fine particles B.

(2) Inkjet recording method using a recording liquid set In the inkjet recording method using a recording liquid set, regarding the method of applying the pretreatment liquid, the description of the method of applying the pretreatment liquid in "3. Inkjet recording method". For the inkjet method using inkjet ink, the description of the inkjet method in "3. Inkjet recording method" is incorporated.

Hereinafter, examples of the present invention will be described, but the present invention is not limited to such examples.

Although the display of "parts" or "%" is used in the examples, it represents "parts by mass" or "% by mass" unless otherwise specified.

(Example 1); Water-based inkjet ink 1. Dispersion of water-insoluble resin fine particles A (1) Dispersion A1 of water-insoluble resin fine particles A-1
[Synthesis of water-insoluble resin a-1]
To the reaction vessel, 88 parts of methyl ethyl ketone was added and heated to 72 ° C. under a nitrogen atmosphere. To this, 50 parts of methyl ethyl ketone, 0.85 parts of dimethyl-2,2'-azobisisobutyrate, 50 parts of phenoxyethyl methacrylate, and methacrylic acid were added. A solution in which 12 parts of acid and 38 parts of ethyl methacrylate were dissolved was added dropwise over 3 hours and stirred. After completion of the dropping, the reaction was further carried out for 1 hour, a solution prepared by dissolving 0.42 parts of dimethyl-2,2'-azobisisobutyrate in 2 parts of methyl ethyl ketone was added, the temperature was raised to 78 ° C., and the mixture was heated for 4 hours. The obtained reaction solution was reprecipitated twice in an excess amount of hexane, and the precipitated resin was dried to combine phenoxyethyl methacrylate / ethyl methacrylate / methacrylic acid (copolymerization ratio [mass ratio] = 50/38/12). 96.3 g of a polymer (water-insoluble resin a-1) was obtained.

[Preparation of dispersion A1 of water-insoluble resin fine particles A-1]
Pigment Blue 15: 3 (“Pthalocyanine Blue A220” manufactured by Dainichi Seika Co., Ltd.) 22.0 parts, 11.0 parts of the above-mentioned water-insoluble resin a-1, 42 parts of methyl ethyl ketone, and 1 specified NaOH aqueous solution 12. One part and 75.1 parts of ion-exchanged water were mixed and dispersed in a bead mill using 0.1 mmφ zirconia beads for 2 to 6 hours. Methyl ethyl ketone was removed from the obtained dispersion at 55 ° C. under reduced pressure, and a part of water was further removed to obtain a dispersion A1 of water-insoluble resin fine particles A-1 having a pigment concentration of 22.0% by mass. Obtained.

(2) Dispersion A2 of water-insoluble resin fine particles A-2
In the preparation of the dispersion A1 described above, the water-insoluble resin fine particles A-2 were used in the same manner as in the preparation of the dispersion A1 except that the following water-insoluble resin a-2 was used instead of the water-insoluble resin a-1. Dispersion A2 was obtained.

[Synthesis of water-insoluble resin a-2]
In the synthesis of the water-insoluble resin a-1 described above, the water-insoluble resin a-1 was used except that 70 parts of phenoxyethyl methacrylate was used, 7 parts of methacrylic acid was used, and 23 parts of methyl methacrylate was used instead of 38 parts of ethyl methacrylate. Phenoxyethyl methacrylate / methyl methacrylate / methacrylic acid (copolymerization ratio [mass ratio] = 70/23/7) copolymer (water-insoluble resin a-2) was synthesized in the same manner as in the above synthesis.

(3) Dispersion A3 of water-insoluble resin fine particles A-3
[Synthesis of water-insoluble resin a-3 and preparation of solution]
By the synthesis method described in "Production Example 1" of Patent Document 1, 96.0 parts of methacrylic acid as an ionic monomer, 264 parts of styrene and 180 parts of styrene-based macromer as a hydrophobic monomer, and 180 parts of styrene-based macromer in an organic solvent (methyl ethyl ketone). As a nonionic monomer, 150 parts of "NK ester M-40G" manufactured by Shin-Nakamura Chemical Industry Co., Ltd. was copolymerized. At this time, 2,2'-azobis (2,4-dimethylvaleronitrile) (“V-65” manufactured by Wako Pure Chemical Industries, Ltd.) was used as the polymerization initiator, and 2-mercaptoethanol was used as the polymerization chain transfer agent. .. As a result, a solution of the water-insoluble resin a-3 (solid content concentration 40.8%) was obtained. The weight average molecular weight of the obtained water-insoluble resin a-3 was 52,700.

[Preparation of dispersion A3 of water-insoluble resin fine particles A-3]
<Step 1>
157.6 g of the water-insoluble resin a-3 solution (solid content concentration 40.8%) obtained above was mixed with 60.7 g of methyl ethyl ketone to obtain a MEK solution of the water-insoluble resin a-3. The MEK solution is put into a disper, and while stirring, 446.9 g of ion-exchanged water, 22.3 g of a 5N sodium hydroxide aqueous solution, and 1.7 g of a 25% aqueous ammonia solution are added to neutralize with sodium hydroxide. The neutralization level with 78.8% and ammonia was adjusted to 21.2%, and the mixture was stirred at 1400 rpm for 15 minutes while cooling in a water bath at 0 ° C. Next, 150 g of Pigment Blue 15: 3 (“Pthalocyanine Blue A220” manufactured by Dainichiseika Co., Ltd.) was added, and the mixture was stirred at 7000 rpm for 3 hours. Further, 199.8 g of ion-exchanged water was added, and the obtained pigment mixture was dispersed and treated with a high-pressure homogenizer to obtain a dispersion-treated product (solid content concentration: 21.0% by mass).

<Step 2>
1000 g of the dispersion-treated product obtained in step 1 was placed in a 2 L eggplant flask, 400 g of ion-exchanged water was added (solid content concentration 15.0% by mass), and the temperature was adjusted to 32 ° C. at a rotation speed of 50 rpm using a rotary evaporator. The organic solvent was removed by holding at a pressure of 0.09 MPa for 3 hours in a warm bath. Further, the warm bath was adjusted to 62 ° C., the pressure was lowered to 0.07 MPa, and the mixture was concentrated to a solid content concentration of 25.0% by mass. The obtained concentrate was put into a 500 ml angle rotor, centrifuged at 7000 rpm for 20 minutes using a high-speed cooling centrifuge (20 ° C.), and then the liquid layer portion was filtered with a 5 μm membrane filter to obtain the pigment dispersion a3. Obtained.

<Process 3>
To 400 g of the pigment dispersion a3 (Pigment Blue 15: 3 68.6 g, water-insoluble resin a-3 29.4 g) obtained in Step 2, 54.6 g of ion-exchanged water was added, and further, an antifungal agent (Arch Chemicals) was added. Japan's "Proxel LVS", effective content 20%) 0.89 g, epoxy cross-linking agent (trimethylolpropane polyglycidyl ether; Nagase Chemtex's "Denacol EX321L", epoxy equivalent 129) 2.82 g (cross-linking rate 40) (Corresponding to the amount to be mol%) was added, and the mixture was stirred at 70 ° C. for 2 hours. After cooling to 25 ° C., the mixture was filtered through a 5 μm membrane filter, and ion-exchanged water was further added so that the solid content concentration became 22.0% by mass to obtain a dispersion A3 of water-insoluble resin fine particles A-3. The cross-linking rate of the water-insoluble resin fine particles A-3 was 40 mol%, and the average particle size was 93.1 nm.

(4) Dispersion A4 of water-insoluble resin fine particles A-4
49.6 g of ion-exchanged water is added to 400 g of the pigment dispersion a3 (Pigment Blue 15: 3 68.6 g, water-insoluble resin a-3 29.4 g) obtained in step 2 in the preparation of the dispersion A3 described above. Further, an antifungal agent (“Proxel LVS”, effective content 20%) 0.89 g and an epoxy cross-linking agent (“Denacol EX321L, epoxy equivalent 129) 1.41 g (corresponding to an amount that makes the cross-linking rate 20 mol%) are added). Then, the mixture was stirred at 70 ° C. for 2 hours. After cooling to 25 ° C., the mixture was filtered with a 5 μm membrane filter, ion-exchanged water was further added so that the solid content concentration became 22.0% by mass, and the water-insoluble resin fine particles A were added. A dispersion A4 of -4 was obtained. The crosslinking rate of the water-insoluble resin fine particles A-4 was 20 mol%, and the average particle size was 92.5 nm.

(5) Dispersion A5 (resin dispersion)
Pigment Blue 15: 3 ("Futarosinin Blue A220" manufactured by Dainichi Seika Co., Ltd.) is 22.0% by mass, and a pigment dispersant (sodium hydroxide-neutralized carboxyl group) that is a water-soluble polymer compound is acrylic. Dispersant (BASF "John Krill 819", acid value 75 mgKOH / g, solid content 20% by mass) was 31.5% by mass, ethylene glycol was 20.0% by mass, and ion-exchanged water (remaining amount; total amount was After premixing the mixed solution to which 100% by mass was added, the mixture was dispersed using a sand grinder filled with 0.5 mm zirconia beads at a volume ratio of 50%, and the pigment content was 22.0% by mass. Dispersion A5 was prepared.

3. 3. Water-insoluble resin fine particles B
(1) Dispersion B1 of water-insoluble resin fine particles B-1
<Synthesis of urethane prepolymer solution b-1>
In a four-necked flask equipped with a stirrer, a reflux cooling tube, a thermometer and a nitrogen blowing tube, 182 parts by mass of a polycarbonate polyol (molecular weight 1000, "Nipporan 981" manufactured by Nippon Polyurethane Industry Co., Ltd.) and polyethylene glycol (PEG, molecular weight) 600, "PEG600" manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) by 22.0 parts by mass, trimetylolpropane by 5.6 parts by mass, N-methyl-N, N-diethanolamine by 43.8 parts by mass, 4, Take 204 parts by mass of 4'-dicyclohexylmethane diisocyanate and 216 parts by mass of methyl ethyl ketone (MEK) in a reaction vessel (addition amount of tertiary amine 9.6% by mass, addition amount of PEG 4.8% by mass) and bring to 75 ° C. The reaction was carried out while maintaining the urethane prepolymer. 46.4 parts by mass of dimethylsulfuric acid is added to this urethane prepolymer and reacted at 50 to 60 ° C. for 30 to 60 minutes to obtain a cationic NCO content of 2.2% and a non-volatile content of about 50% by mass. A methyl ethyl ketone solution b-1 of urethane prepolymer was obtained.
<Formation of composite resin and preparation of dispersion B1>
Polyolefin-based resin (“Aurolen 150S” manufactured by Nippon Paper Industries, Ltd. (denoted as “150S” in Table I)) 70. 0 parts by mass, 240.0 parts by mass of methylcyclohexane and 48.0 parts by mass of methylethylketone were added, and the temperature was raised to 80 ° C. to dissolve them by heating. After dissolution, the internal temperature was maintained at 40 ° C., 60.0 parts by mass of urethane polymer solution b-1 (nonvolatile content of about 50% by mass) was added, and the mixture was mixed. 58.0 parts by mass of water was added to this solution, emulsified using a homogenizer, and then 570 parts by mass of water was gradually added to dilute the solution, and 1.0 part by mass of ethylenediamine and 12 parts by mass of water were mixed. Aqueous solution was gradually added and stirred for 1 hour for polymerization. This was desolved under reduced pressure at 50 ° C. to obtain a dispersion B1 of water-insoluble resin fine particles B-1 having a non-volatile content (solid content as particles) of about 30% by mass. The value (PU / PO) of the mass ratio of the polyurethane-based resin (PU) and the polyolefin-based resin (PO) in the water-insoluble resin fine particles B-1 is 70/30.

(2) Dispersion B2 of water-insoluble resin fine particles B-2
In the preparation of the dispersion B1 described above, the polyolefin resin in "Formation of composite resin and preparation of dispersion B1>" is 50.0 parts by mass, and the urethane polymer solution b-1 (nonvolatile content is about 50% by mass) is 100. A dispersion B2 of water-insoluble resin fine particles B-2 having a non-volatile content (solid content as particles) of about 30% by mass was obtained in the same manner as in the preparation of the dispersion B1 except that the content was 0.0 parts by mass. The value (PU / PO) of the mass ratio of the polyurethane-based resin (PU) and the polyolefin-based resin (PO) in the water-insoluble resin fine particles B-2 is 50/50.

(3) Dispersion B3 of water-insoluble resin fine particles B-3
As the water-insoluble resin fine particles B-3, "Aurolen AE202" (polyolefin resin particles; solid content 30%) manufactured by Nippon Paper Industries, Ltd. was used.

(4) Dispersion B4 of water-insoluble resin fine particles B-4
As the water-insoluble resin fine particles B-4, "Superflex 620" manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. (polyolefin resin particles; non-volatile content (solid content as particles) of about 30% by mass) was used.

(5) Dispersion B5 of water-insoluble resin fine particles B-5
A reaction vessel containing 3718 g of a polyoxypropylene (2.2) adduct of bisphenol A, 1282 g of fumaric acid, 25 g of di (2-ethylhexanoic acid) tin as an esterification catalyst, and 0.25 g of gallic acid as an esterification co-catalyst. The mixture was stirred inside and reacted at 210 ° C. for 10 hours in a nitrogen atmosphere to obtain a polyester resin. 200 g of the obtained polyester resin is dissolved in 200 g of methyl ethyl ketone (MEK), 3.26 g of 25% ammonia water and 467 g of ion-exchanged water are added thereto as a neutralizing agent, and the temperature is 10 ° C. or higher and 15 ° C. or lower using a disper blade. Stirring and mixing were carried out at 2000 rpm for 15 minutes to obtain water-insoluble resin fine particles B-5 of a dispersion of polyester resin particles (nonvolatile content (solid content as particles) of about 40% by mass).

4. Preparation of Ink In the formulation shown in Table 1, the dispersions A1 to A5 are stirred with the dispersions B1 to B5, the following organic solvent, a surfactant (“Megafuck F-444” manufactured by DIC), and ion-exchanged water. The mixture was added while the ink was added, and the obtained mixed solution was filtered through a 1 μm filter to obtain inks 1 to 16. There was no substantial change in composition before and after filtration.
<Organic solvent>
・ Dires: 1,2-butanediol, 1,2-hexanediol ・ Glycols: Propylene glycol, triethylene glycol ・ Others: Glycerin

5. Evaluation method (1) Versatility of base material (adhesion)
Two independent drive heads of Konica Minolta's piezo type inkjet head (360 dpi, discharge rate 14 pL) are arranged so that the nozzles are staggered to create a head module of 720 dpi x 720 dpi, and the transfer direction is on the stage transfer machine. The nozzle rows were installed so as to be orthogonal to each other, and an inkjet recording device was configured so that a solid image could be recorded on a base material conveyed by a stage transfer machine by a single pass method.
Ink is applied to each of the three types of base materials (polypropylene base material, nylon base material, and paper base material) at an ink application amount of 11.2 cc / m ² by an inkjet method using such an inkjet recording device, and the ink is applied onto the base materials. The applied ink was dried to form a coating film. The coating film (image) was allowed to stand in an environment having a temperature of 25 ° C. and a relative humidity of 60% for 24 hours, and then folded into a mountain fold. After that, an adhesive tape (3M's "Scotch ultra-transparent tape S", Scotch is a registered trademark) was attached to each color section so as to straddle the creases, and was slowly peeled off. Whether or not a portion where the coating film was peeled off was visually observed in the crease portion after the adhesive tape was peeled off was visually observed and evaluated according to the following evaluation criteria.
〔Evaluation criteria〕
⊚: No peeling of the coating film is observed at the creases of all the substrates ○: Slight peeling of the coating film is observed on some substrates △: Large peeling of the coating film is observed on some substrates Approved ×: Large peeling of the coating film is observed on all substrates.

(2) Color development (suppression of strike-through, density)
In the above "(1) Versatile base material (adhesion)", the coating film formed on the front surface of the paper base material was observed from the back surface and evaluated according to the following evaluation criteria.
〔Evaluation criteria〕
〇: The coating film is not visible Δ: The coating film is slightly visible ×: The coating film is clearly visible

(3) Gloss In the above "(1) Versatility (adhesion) of the base material", the gloss of the coating film formed on the paper base material was evaluated according to the following evaluation criteria.
〔Evaluation criteria〕
◯: Gloss is uniform Δ: Gloss is partially uneven ×: Gloss is non-uniform

The above results are shown in Table 1.

6. From the evaluation table 1, it can be seen that according to the inks 1 to 9 of the present invention, the effects of excellent substrate versatility, color development and gloss can be obtained.

(Example 2); Recording liquid set 1. In 16.7 parts by mass (solid content 5.0 parts by mass) of the pretreatment liquid dispersion B2, 40.0 parts by mass of 1,2-butanediol, 10.0 parts by mass of 1,2-hexanediol, and a surfactant. ("Megafuck F-444" manufactured by DIC) Add 0.3 parts by mass and 33.0 parts by mass of ion-exchanged water with stirring, and filter the obtained mixed liquid with a 1 μm filter to prepare the pretreatment liquid 1. Got

2. 2. Inkjet ink As the inkjet ink, the ink 4 shown in Table 1 was used.

3. 3. Inkjet recording method The above-mentioned pretreatment liquid is applied onto three types of base materials (polypropylene base material, nylon base material, and paper base material) with a # 3 wire bar and dried to form a pretreatment layer, and then The above-mentioned inkjet ink was applied onto the pretreatment layer by an inkjet method using the same inkjet recording apparatus as in Example 1 at an ink jet amount of 11.2 cc / m ² , and an image was recorded.

4. Evaluation When the image (coating film) formed by Example 2 was evaluated in the same manner as in Example 1, the adhesion was ⊚, the density was ⊚, and the gloss was ◯. It is considered that the above effects were obtained as a result of the water-insoluble resin fine particles B in the pretreatment liquid being oriented on the substrate.

F: Base material P: Pretreatment layer R: Printing layer 1: Feeding roller 2: Roll coater 3: Nozzle 4: Pretreatment droplet 5: First drying part 6: Inkjet head 7: Ink droplet 8: Second drying Part 9: Take-up roller 10: Inkjet recording device

Claims (7)

A water-based inkjet ink containing at least water-insoluble resin fine particles A containing a pigment, water-insoluble resin fine particles B containing no pigment, an organic solvent C, and water.
The resin fine particles B are composite resin particles obtained by emulsifying a polyolefin resin with a polyurethane resin, and the polyurethane resin exists at the interface between the polyolefin resin as a water-insoluble resin and water which is a continuous phase. It functions as a water-insoluble resin layer that protects the polyolefin resin, and the value (PU / PO) of the mass ratio of the polyurethane resin (PU) and the polyolefin resin (PO) in the composite resin particles is 50. It is in the range of / 50 to 70/30,
A water-based inkjet ink containing at least one selected from glycols and diols as the organic solvent C. The water-based inkjet ink according to claim 1, wherein the water-insoluble resin fine particles B contain a composite resin obtained by emulsifying a polyolefin resin into a polyurethane resin. The water-based inkjet ink according to claim 1 or 2, wherein the water-insoluble resin fine particles A are obtained by cross-linking water-insoluble resin fine particles containing a pigment. A pretreatment liquid containing at least the water-insoluble resin fine particles B containing no pigment, and
A water-based inkjet ink containing at least water-insoluble resin fine particles A containing a pigment, an organic solvent C, and water.
Consists of
The resin fine particles B are composite resin particles obtained by emulsifying a polyolefin resin with a polyurethane resin, and the polyurethane resin exists at the interface between the polyolefin resin as a water-insoluble resin and water which is a continuous phase. It functions as a water-insoluble resin layer that protects the polyolefin resin, and the value (PU / PO) of the mass ratio of the polyurethane resin (PU) and the polyolefin resin (PO) in the composite resin particles is 50. It is in the range of / 50 to 70/30,
A recording liquid set containing at least one selected from glycols and diols as the organic solvent C. The recording liquid set according to claim 4, wherein the water-insoluble resin fine particles B contain a composite resin obtained by emulsifying a polyolefin resin into a polyurethane resin. The recording liquid set according to claim 4 or 5, wherein the water-insoluble resin fine particles A are formed by cross-linking water-insoluble resin fine particles containing a pigment. An inkjet recording method using the recording liquid set according to any one of claims 4 to 6.
The pretreatment liquid is applied onto the base material to form a pretreatment layer, and the pretreatment layer is formed.
Next, an inkjet recording method characterized in that the inkjet ink is applied onto the pretreatment layer by an inkjet method to record an image.

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