JP2020012014A - Ink jet ink composition and ink jet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet ink composition excellent in intermittent ejection stability, continuous printing stability, clogging stability, scratch resistance, and glossiness, and an inkjet recording method. An inkjet ink composition containing resin particles, wherein the resin particles contain a copolymer containing a specific polyol and a specific polyisocyanate as polymerization components, respectively, and the amount is 5 to 50 mgKOH / An inkjet ink composition having an acid value of g. [Selection diagram] None

Description

  The present invention relates to an inkjet ink composition and an inkjet recording method.

  The ink jet recording method is capable of recording an image with high definition using a relatively simple device, and is rapidly developing in various fields. The performance required for the ink used in the ink jet recording method includes the ejection stability of the ink, the robustness of the image, and the like. In order to improve these performances, inkjet inks using various polyurethane resins have been studied.

  Patent Literature 1 discloses an aqueous polyurethane emulsion in which a polyurethane resin obtained by reacting an organic polyisocyanate containing an allophanate-modified polyisocyanate with an active hydrogen group-containing compound is emulsified in water. The allophanate-modified polyisocyanate is obtained from an alkoxypoly (oxyalkylene) glycol having a predetermined ratio of oxyethylene groups and hexamethylene diisocyanate in a repeating unit, and contains substantially no isocyanurate group. According to this document, an aqueous polyurethane emulsion can form a film having excellent resolubility and adhesion by containing a specific allophanate-modified polyisocyanate, and can improve plate clogging when used in an aqueous printing ink. Is disclosed.

  Patent Literature 2 discloses an inkjet ink including a pigment, a polyurethane resin having a unit derived from each of a polyisocyanate, a polyol, and a diol having an acid group, and a pigment. In this document, the inkjet ink obtained by setting the acid value of the polyurethane resin within a predetermined range and setting the content of a unit derived from a specific compound to a predetermined value or less in a unit derived from a polyisocyanate, It is disclosed that the performance including scratch resistance of an image and ink ejection stability can be improved.

  Patent Document 3 discloses a composite resin particle (A4) formed by reacting an isocyanate group-containing polyurethane (A1), a polyisocyanate (A2) other than (A1), and a polyamine (A3), and an acetylene compound (B). And a method for producing a binder for an ink jet printing ink containing an aqueous medium (C). According to the production method of this document, first, a polyol (a1) containing a hydrophilic group-containing polyol (a1-1) is reacted with a polyisocyanate (a-2) in an organic solvent (D) or under no solvent. Thus, an isocyanate group-containing polyurethane (A1) is obtained, and an organic solvent (D) is supplied as needed to produce an organic solvent (D) solution [I] of the isocyanate group-containing polyurethane (A1). Next, the isocyanate group-containing polyurethane (A1) is mixed with the organic solvent (D) solution [I], the polyisocyanate (A2), the polyamine (A3), the acetylene compound (B), and the aqueous medium (C). A mixture [II] containing the composite resin particles (A4) formed by the reaction between the polyisocyanate (A2) and the polyamine (A3) is produced. Further, part or all of the organic solvent (D) contained in the mixture [II] is removed. This document discloses that an ink containing a binder for an inkjet printing ink obtained through these steps is capable of forming a printed image having excellent ink ejection properties and compounding stability, and excellent scratch resistance and alkali resistance. ing.

JP-A-2006-022132 JP 2012-140602 A JP 2013-035897 A

  Like the urethane-based polymers or particles thereof described in Patent Documents 1 to 3, since they have many polar groups such as a hydrophilic group and a urethane group, a large amount of urethane-based polymer is particularly contained in ink containing water or a water-soluble solvent. The use of molecules increases the viscosity. In the ink jet recording method, when the viscosity of the aqueous ink increases, ejection becomes unstable, continuous printing stability decreases, and clogging tends to occur, resulting in low clogging stability. Therefore, it is conceivable to limit the amount of the water-based ink. In this case, however, the ink does not have sufficient abrasion resistance with respect to the recording medium, and an image is formed on a recording medium such as an OPP film which requires gloss. The glossiness when printing is low. Further, when recording is performed by the inkjet recording method, a state in which the ink is not ejected from the nozzle of the inkjet head for a certain period of time continues, and as a result, water in the ink evaporates from the nozzle. Thereafter, when the next ink is to be ejected from the nozzle, the ink droplet may not fly straight or may not be ejected. The ink in which such a phenomenon occurs has low intermittent ejection stability.

  Therefore, an inkjet ink having excellent intermittent ejection stability, continuous printing stability, clogging stability, abrasion resistance, and glossiness has not yet been found.

  The present inventors have conducted intensive studies to solve the above problems. As a result, an inkjet ink composition containing a specific polyol and a copolymer containing a specific polyisocyanate as a polymerizable component, respectively, and containing resin particles having an acid value within a predetermined range can solve the above-described problems. Was found.

(1) That is, the present invention relates to an ink-jet ink composition containing resin particles, wherein the resin particles contain a copolymer containing a polyol and a polyisocyanate as polymerization components, respectively, and 5 to 50 mg KOH. / G, wherein the polyol is a polydiene polyol having two or more hydroxyl groups, a polyolefin polyol having two or more hydroxyl groups, or a cyclic polyol having two or more hydroxyl groups, and A hydrocarbon compound having a hydrocarbon structure, wherein the polyisocyanate is dicyclohexylmethane diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, m-bis (isocyanatopropyl) benzene, m-bis (isocyanatemethyl) Benzene and It is at least one selected from the group consisting of polyisocyanates containing as a polymerization component at least one of these is an inkjet ink composition.
(2) The copolymer may be a copolymer further containing at least one of a polyamine and a carboxyl group-containing glycol as a polymerization component.
(3) The copolymer may be a copolymer further containing a polyamine and a carboxyl group-containing glycol as polymerization components.
(4) The copolymer may contain an isocyanate group-terminated prepolymer or a hydroxyl group-terminated prepolymer.
(5) The copolymer may be a polyurethane resin or a polyurethane polyurea resin.
(6) Another aspect of the present invention is an inkjet recording method including an ejection step of ejecting the above-described inkjet ink composition onto a recording medium.
(7) The recording medium may be a recording medium having non-absorbency or slight absorbability.

  Hereinafter, an embodiment of the present invention (hereinafter, referred to as “the present embodiment”) will be described in detail, but the present invention is not limited thereto, and various modifications can be made without departing from the gist of the present invention. It is.

  In the present specification, “scratch resistance” and “glossiness” refer to the scratch resistance and glossiness of an image formed using the inkjet ink composition of the present embodiment, respectively. In the present specification, the “fixing property” refers to the fixing property of an image formed using the inkjet ink composition of the present embodiment on a recording medium.

[1. Ink jet ink composition)
The inkjet ink composition of the present embodiment is an inkjet ink composition containing resin particles. In the present specification, the inkjet ink composition may be referred to as “ink”. The resin particles contain a copolymer containing a polyol and a polyisocyanate as polymerization components, respectively, and have an acid value of 5 to 50 mgKOH / g. The polyol is a polydiene polyol having two or more hydroxyl groups, a polyolefin polyol having two or more hydroxyl groups, or a hydrocarbon compound having two or more hydroxyl groups and having a cyclic hydrocarbon structure. . In addition, in the present specification, these polyols may be referred to as “specific polyols”. The polyisocyanate includes dicyclohexylmethane diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, m-bis (isocyanatopropyl) benzene, m-bis (isocyanatomethyl) benzene, and one or more of these diisocyanates as a polymerization component. At least one selected from the group consisting of polyisocyanates. In this specification, these polyisocyanates may be referred to as “specific polyisocyanates”. According to such an inkjet ink composition, it is excellent in intermittent ejection stability, continuous printing stability, clogging stability, abrasion resistance, and glossiness. This factor is considered as follows, but the factor is not limited to this. That is, the polyisocyanate contained as a polymerization component in the resin particles of the present embodiment is dicyclohexylmethane diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, m-bis (isocyanatopropyl) benzene m-bis (isocyanatemethyl). ) One or more selected from the group consisting of benzene and polyisocyanates containing one or more of these diisocyanates as a polymerization component. In all of these polyisocyanates, the position where the isocyanate group is bonded is a position where crystallization or stacking is difficult when polymerized to form a polymer. Due to this, the ink of the present embodiment can form an image having excellent scratch resistance and glossiness. Further, when the ink contains other components such as water and pigment, for example, due to the acid value of the resin particles of the present embodiment being 5 mgKOH / g or more and 50 mgKOH / g or less, The interaction with these other components is in an appropriate range. As a result, the ink of the present embodiment is excellent in intermittent ejection stability, continuous printing stability, and clogging stability.

  In the inkjet ink composition of the present embodiment, the copolymer preferably further contains a carboxyl group-containing glycol as a polymerization component. The carboxyl group-containing glycol is preferably one selected from the group consisting of dimethylolacetic acid, dimethylolpropionic acid, dimethylolbutanoic acid, and dimethylolbutyric acid, and is dimethylolpropionic acid and / or dimethylolbutanoic acid. Is more preferable, and dimethylolpropionic acid is further preferable. Accordingly, the ink-jet ink composition can easily have an acid value within a desired range, and is further excellent in fixability of a formed image to a recording medium.

  In the inkjet ink composition of the present embodiment, the polyol is preferably a polyolefin polyol having two or more hydroxyl groups, and the polyolefin polyol having two or more hydroxyl groups is preferably a saturated or unsaturated polyolefin polyol. More preferably, it contains more than one species. Thereby, the inkjet ink composition is more excellent in the scratch resistance and fixability of the formed image.

  In the inkjet ink composition of the present embodiment, the weight average molecular weight of the saturated or unsaturated polyolefin polyol is preferably 500 or more and 3000 or less. Thereby, the inkjet ink composition is more excellent in the flexibility of the solidified product of the inkjet ink composition, and is more excellent in at least one of the fixability and the scratch resistance of the formed image. The weight average molecular weight is determined by a GPC measurement method in terms of polystyrene.

  In the inkjet ink composition of the present embodiment, the copolymer preferably further contains a polyamine as a polymerization component, more preferably contains one or more of an aliphatic diamine and an aromatic diamine, and has 1 or more carbon atoms. It is more preferred that it contains no more than 8 alkyl diamines. Thereby, the inkjet ink composition is more excellent in flexibility of the solidified product of the inkjet ink composition, and more excellent in fixability and scratch resistance of a formed image. Specific examples of the polyamine will be described later [1.1.2.3. [Other Starting Materials]).

  For the reasons described above, the copolymer preferably further contains a polyamine and a carboxyl group-containing glycol as polymerization components.

  In the inkjet ink composition of the present embodiment, the copolymer preferably further contains lactam as a polymerization component, and the lactam is more preferably 2-pyrrolidone. Thereby, the inkjet ink composition can easily and stably produce a desired copolymer, and the inkjet ink composition containing this copolymer is more excellent in abrasion resistance and glossiness.

[1.1. (Copolymer)
In the inkjet ink composition of the present embodiment, the resin particles are, for example, a group derived from a specific polyisocyanate and a specific polyolefin polyol, and have at least one group selected from urethane groups and urea groups. You may contain coalescence. In this specification, a copolymer may be referred to as a “polymer”. In the present specification, when the copolymer has a urethane group, the copolymer is referred to as a polyurethane resin, and when the copolymer has a urethane group and a urea group, the copolymer is referred to as a polyurethane polyurea resin. The copolymer is preferably a polyurethane resin or a polyurethane polyurea resin, and more preferably a polyurethane polyurea resin, from the viewpoint of more effectively and reliably achieving the effects of the present invention.

[1.1.1. Outline of polymer)
In the inkjet ink composition of the present embodiment, the polymer is a resin that is polymerized using a polyisocyanate, and is polymerized using a polyisocyanate, a polyol, and if necessary, a polyamine or the like. As a result, for example, an isocyanate group-terminated prepolymer having an isocyanate group at the terminal and a hydroxyl group-terminated prepolymer having a hydroxyl group at the terminal are obtained. It is preferable that the copolymer contains an isocyanate group-terminated prepolymer or a hydroxyl group-terminated prepolymer from the viewpoint of more effectively and reliably achieving the effects of the present invention. Here, the copolymer may be further polymerized using a polyol or a polyamine as a crosslinking agent or a chain extender, if necessary. The polymer includes one or more groups selected from a urethane bond generated by a reaction between an isocyanate group and a hydroxyl group, and a urea bond generated by a reaction between an isocyanate group and an amino group. It may have a branched form. In the present specification, a urethane bond is also referred to as a “urethane group”, and a urea bond is also referred to as a “urea bond” or “urea group”.

  In the present specification, when the copolymer is referred to as a polymer, regardless of the presence or absence of a crosslinked structure, those having thermoplasticity, and those having a crosslinked structure formed and exhibiting no or only a small amount of Tg or melting point Shall be included.

  The isocyanate group for forming the urethane bond is supplied, for example, from a compound containing an isocyanate group. Further, a hydroxyl group (hydroxyl group) for forming a urethane bond is supplied from, for example, a compound containing a hydroxyl group. Then, in order to polymerize, a compound having an isocyanate group has two or more isocyanate groups, and a compound having a hydroxyl group is selected from those having two or more hydroxyl groups and polymerized. In the present specification, a compound having two or more isocyanate groups is also referred to as “polyisocyanate”, and a compound having two or more hydroxyl groups is also referred to as “polyol”. In addition, the compound which has two isocyanate groups among these is also called "diisocyanate", and the compound which has two hydroxyl groups is also called "diol".

  In addition, the molecular chain between the isocyanate groups of the polyisocyanate and the molecular chain between the hydroxyl groups of the polyol and / or the molecular chain between the amino groups of the polyamine may have a urethane bond or urea in the case of polyurethane. It is a part other than the connection. In the present specification, all or a part of a portion other than a urethane bond or a urea bond in the case of a polyurethane may be referred to as a skeleton. The skeleton may have a linear or branched morphology.

  Further, the polymer may include a bond other than a urethane bond and a urea bond. Examples of such a bond include a buret bond generated by a reaction between a urea bond and an isocyanate group, and a bond between the urethane bond and the isocyanate group. Examples include an alphanate bond generated by the reaction, a uretdione bond by dimerization of an isocyanate group, and an isocyanurate bond by trimerization of an isocyanate group. These bonds can be positively generated or not generated depending on the reaction temperature or the like. Therefore, for example, when a polyisocyanate, a polyol, and a polyamine coexist, a polymer containing not only urethane bonds and urea bonds but also these bonds (groups) can be generated. Since the polymer has an allophanate structure, biuret structure, uretdione structure and isocyanurate structure, the adhesion to a recording medium is increased and the film strength is increased, and as a result, the abrasion resistance tends to be further improved.

  In the present specification, a compound having two or more amino groups is also referred to as “polyamine”. A compound having two amino groups is also referred to as “diamine”.

[1.1.2. Polymer raw material)
The polymer of the present embodiment is polymerized using at least a diisocyanate and a polyol. The polymer of the present embodiment may be polymerized by further using a polyamine, and may be further polymerized by further using a polyol, a polyamine, or the like as a crosslinking agent or a chain extender as needed.

[1.1.2.1. Polyisocyanate)
The polyisocyanate used for the polymer of the present embodiment includes dicyclohexylmethane diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, m-bis (isocyanatopropyl) benzene, m-bis (isocyanatomethyl) benzene and And at least one diisocyanate selected from the group consisting of polyisocyanates containing at least one diisocyanate as a polymerization component. The chemical structures of these diisocyanates are shown below. Representative examples of dicyclohexylmethane diisocyanate are shown below. In addition, these diisocyanates can be variously named by common names or the like, and all of them have many aliases. Therefore, a CAS number is also written in place of the alias.

Dicyclohexylmethane diisocyanate: CAS = 5124-30-1

Isophorone diisocyanate: CAS = 4098-71-9

1,3-bis (isocyanatomethyl) cyclohexane: CAS = 38661-72-2

m-bis (isocyanatopropyl) benzene: CAS = 2778-42-9

m-bis (isocyanatomethyl) benzene: CAS = 3634-83-1

  When these diisocyanates are polymerized to form a polymer together with, for example, a hydroxyl group or an amino group, a cyclohexyl ring or a benzene ring can be bonded to a position where stacking or crystallization is difficult. Accordingly, the polymer is prevented from increasing the density of the microphase separation structure or the crosslinked structure of the microcrystal too much. Therefore, the glass transition temperature Tg of the polymer can be lowered, and the flexibility of the polymer can be increased. Thereby, when the ink-jet ink composition is adhered to a recording medium, it is possible to improve the scratch resistance and fixability of the image and to form an image having sufficient gloss.

  The polyisocyanate is, among these, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, m-bis (isocyanatopropyl) benzene, m-bis (isocyanatomethyl) benzene and one or more of these diisocyanates as a polymerization component. Is preferably at least one selected from the group consisting of polyisocyanates, and more preferably a polyisocyanate containing one or more of these diisocyanates as a polymerization component. The isocyanate group content of the polyisocyanate containing at least one of these diisocyanates as a polymerization component is preferably 10.0 to 30.0% by mass. The isocyanate group in these polyisocyanates is arranged at the meta position of the six-membered ring, that is, in a 1,3-configuration, so that the cyclohexyl ring or benzene ring is polymerized so as to have a structure that is difficult to stack or crystallize. . Therefore, when these are polymerized to form a polymer such as a urethane resin, it is possible to prevent the density of the microphase-separated structure or the crosslinked structure of microcrystals from being too high. As a result, the glass transition temperature Tg of the polymer can be further reduced, and the flexibility of the polymer can be further increased. Thereby, when the ink-jet ink composition is attached to a recording medium, it is possible to further improve the scratch resistance and fixability of the image and to form an image having a sufficient gloss.

Examples of the dicyclohexylmethane diisocyanate include dicyclohexylmethane 4,4′-diisocyanate, a mixture of dicyclohexylmethane 2,2′-diisocyanate and a mixture of dicyclohexylmethane 2,4′-diisocyanate, and a single substance thereof. Dicyclohexylmethane diisocyanate may be used in the form of a polyfunctional isocyanate consisting of a dimer or more of any combination of these. The polyfunctional polyisocyanate has a structure composed of two or more molecules of polyisocyanate, and has two or more isocyanate groups at the terminal of the molecule to react with a hydroxyl group of a polyol or an amino group (NH ₂ group) of a polyamine. Compound. These polyfunctional polyisocyanates may contain at least one selected from the group consisting of an allophanate structure, a uretdione structure, an isocyanurate structure and a biuret structure. The polyfunctional polyisocyanate has a structure composed of a monomeric diisocyanate or a polymeric two or more molecules of polyisocyanate, and preferably has many branches in the molecule. Such a polymer having a structure composed of a polyfunctional polyisocyanate has a structure in which molecules are intricately entangled and a state in which urethane bonds are densely packed. Therefore, even if the acid value is relatively low, it can be stably dispersed in the aqueous ink. By using these polyisocyanates, the inkjet ink composition can provide an image having more excellent abrasion resistance and glossiness when printed on a film while securing intermittent ejection stability, continuous printing stability and clogging stability. Can be recorded.

[1.1.2.2. Polyol)
The polymer of the present embodiment uses a polyol as a raw material. The polyol is a compound having two or more functional groups, that is, two or more hydroxyl groups. As the polyol in the present embodiment, a polydiene polyol having two or more hydroxyl groups, a polyolefin polyol having two or more hydroxyl groups, or having two or more hydroxyl groups, and having a cyclic hydrocarbon structure There is no particular limitation as long as it is a hydrocarbon compound. Other polyols include, for example, alkylene glycols, polyester polyols, polyether polyols, and polycarbonate diols. Among these, the polyol is preferably a polyolefin polyol having two or more hydroxyl groups. Examples of the polyol include polybutadiene diol, polyisoprene diol, hydrogenated polybutadiene diol, and hydrogenated products of polyisoprene diol. Commercial products are used as these polyols. The amount of the polyol to be added is preferably 10% by mass or more and 80% by mass or less based on the entire raw material of the polymer. When the addition amount of the polyol is 10% by mass or more, the adhesiveness of the ink to the recording medium is further improved. When the addition amount of the polyol is 80% by mass or less, the polyol can be more stably present in water. The addition amount of the polyol is more preferably from 20% by mass to 60% by mass from the viewpoint of adhesiveness. In addition, the molecular weight of the polyol is preferably 500 or more, and more preferably 600 or more and 4000 or less from the viewpoint of adhesiveness.

  As the polyol, a known polyol used as a raw material of the polyurethane resin is used, and a commercially available product may be used. Examples of the polyol include polybutadiene diol mainly having 1,4 bond repeating units and poly (1,2-butadiene) glycol mainly having 1,2 bond repeating units. Examples of commercially available products of polybutadiene diol include "Poly bd (registered trademark) R-15HT" and "Poly bd (registered trademark) R-45HT" manufactured by Idemitsu Kosan Co., Ltd. Commercial products of poly (1,2-butadiene) glycol include, for example, “G-1000”, “G-2000”, and “G-3000” manufactured by Nippon Soda Co., Ltd. Examples of the hydrogenated polybutadiene diol include, for example, hydrogenated polybutadiene diol mainly having 1,4 bond repeating units and hydrogenated polybutadiene diol mainly having 1,2 bond repeating units. Commercial products of hydrogenated polybutadiene diol having mainly 1,4 bond repeating units include, for example, "Polytail H" and "Polytail HA" (both trade names) manufactured by Mitsubishi Chemical Corporation. Examples of the hydrogenated polybutadiene diol mainly having a 1,2-bond repeating unit include "GI-1000", "GI-2000", and "GI-3000" manufactured by Nippon Soda Co., Ltd. Examples of commercially available hydroxyl group-terminated polyalkanediene diols include Epol (registered trademark) (hydrogenated polyisoprene diol, molecular weight: 1,860, average degree of polymerization: 26, a product of Idemitsu Kosan Co., Ltd.), and PIP (polyisoprene). Diol, molecular weight: 2,200, average degree of polymerization: 34, product of Idemitsu Kosan Co., Ltd., polytail H (hydrogenated polybutadiene diol, molecular weight: 2,200, average degree of polymerization: 39, product of Mitsubishi Chemical Corporation), R- 45HT (polybutanediol, molecular weight: 2,270, average degree of polymerization: 42, product of Idemitsu Kosan Co., Ltd.). Examples of commercially available products of polycaprolactone diol include, for example, Praxel (registered trademark) 205, Praxel (registered trademark) L205AL, Praxel (registered trademark) 205U, Praxel (registered trademark) 208, and Praxel (registered trademark) L208AL manufactured by Daicel Corporation. , Praxel (registered trademark) 210, Praxel (registered trademark) 210N, Praxel (registered trademark) 212, Praxel (registered trademark) L212AL, Praxel (registered trademark) 220, Praxel (registered trademark) 220N, Praxel (registered trademark) 220NP1, Praxel® L220AL, Praxel® 230, Praxel® 240, Praxel® 220EB, and Praxel® 220EC.

  As the polyol, besides the specific polyol, for example, at least one selected from the group consisting of dimer diol, hydrogenated dimer diol, castor oil, and castor oil-based modified polyol may be used. The dimer diol refers to a product obtained by reducing a reaction product of a cyclic and / or acyclic dimer acid obtained by dimerizing a higher unsaturated fatty acid and methanol. The term “hydrogenated dimer diol” refers to a product obtained by subjecting dimer diol to a hydrogenation reaction. The higher unsaturated fatty acid is not particularly limited, but includes, for example, unsaturated monocarboxylic acids having about 14 to 22 carbon atoms. Examples of the unsaturated monocarboxylic acid having about 14 to 22 carbon atoms include tetradecadienoic acid, hexadecadienoic acid, linoleic acid, eicosadienoic acid, docosadienoic acid, linolenic acid, arachidonic acid, myristooleic acid, palmitoleic acid, Oleic, elaidic, vaccenic, eicosenoic, erucic, setrenic, and brassic acids. These unsaturated monocarboxylic acids are used alone or in combination of two or more. Among these, the unsaturated monocarboxylic acid is preferably oleic acid and / or linoleic acid. The dimerization reaction of the higher unsaturated fatty acid includes, for example, a method described in Japanese Patent Application Laid-Open No. 9-136861.

  As the polyol, for example, other glycols may be used. Other glycols include, for example, alkylene glycols. Examples of the alkylene glycol include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, 1,2-propylene glycol, 1,3-propanediol, tripropylene glycol, polypropylene glycol, and (poly) tetramethylene glycol. , Hexamethylene glycol, tetramethylene glycol, neopentyl glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,5-pentanediol, 1, 2-hexanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexane Sandimethanol, 4,4-dihydroxyphenylpropane, 4,4-dihydroxyphenylmethane, glycerin, trimethylolethane, trimethylolpropane, 1,2,5-hexanetriol, 1,2,6-hexanetriol, pentaerythritol, Trimethylol melamine, polyoxypropylene triol, dimethyl-1,3-pentanediol, diethyl-1,3-pentanediol, dipropyl-1,3-pentanedyl, dibutyl-1,3-pentanedyl, and 2-butyl- 2-ethyl-1,3-propanediol is exemplified. When an alkylene glycol is used as a polyol, an alkylene glycol having a small molecular weight penetrates into a three-dimensional network formed in the polymer, and the alkylene glycol and the isocyanate react with each other to form a urethane bond. May be obtained. As a result, the ink becomes more excellent in abrasion resistance due to a stronger film.

  As the polyol, for example, a polyester polyol may be used. Examples of the polyester polyol include an acid ester. Examples of the acid component constituting the acid ester include malonic acid, succinic acid, tartaric acid, oxalic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, alkyl succinic acid, linolenic acid, and maleic acid Aliphatic dicarboxylic acids such as fumaric acid, mesaconic acid, citraconic acid and itaconic acid, phthalic acid, naphthalenedicarboxylic acid, biphenyldicarboxylic acid, tetrahydrophthalic acid, and alicyclic dicarboxylic acids such as aromatic hydrogenated products. . Anhydrides, salts, alkyl esters, acid halides and the like of these acid components are also used as the acid components. The alcohol component constituting the acid ester is not particularly limited, and includes, for example, the diol compounds described above.

  As the polyol, for example, a polyether polyol may be used. Examples of the polyether polyol include an addition polymer of an alkylene oxide and a condensation polymer of a polyol such as (poly) alkylene glycol. Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, and α-olefin oxide. Examples of the (poly) alkylene glycol include polyethylene glycol (polyoxyethylene glycol), polypropylene glycol (polyoxypropylene glycol), and polybutylene glycol. Among them, the polyether polyol is preferably polyoxypropylene glycol. Thereby, the flexibility of the polymer is further improved, and the scratch resistance and glossiness of the ink are further improved. Commercial products are used as the polyoxypropylene glycol. Examples of the commercially available products include Exenol series of Asahi Glass Co., Ltd., Newpol PP series of Sanyo Chemical Co., Ltd., and Uniol D series of NOF Corporation. No.

  As the polyol, for example, a polycarbonate diol may be used. The polycarbonate diol contains, for example, two hydroxyl groups and a molecular chain having a carbonate bond. Examples of the polycarbonate diol include a polycarbonate diol obtained by reacting a carbonate component such as an alkylene carbonate, a diaryl carbonate, a dialkyl carbonate, and the like, phosgene, and an aliphatic polyol component. Examples of the polycarbonate diol include alkanediol-based polycarbonate diols such as polyhexamethylene carbonate diol. By using a polycarbonate diol as a starting material for producing a polymer, the resulting polymer tends to be more excellent in heat resistance and hydrolysis resistance. By using polycarbonate diol as the polyol, the scratch resistance of the obtained image is further improved because the polymer has a skeleton derived from the polycarbonate diol.

  The polycarbonate diol is obtained, for example, by a transesterification reaction between a diol compound having two hydroxyl groups in a molecule and a carbonate. Examples of the diol compound include 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 1,5-pentanediol, 1,2-pentanediol, 1,6-hexanediol, 1,5-hexanediol, 1,2-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,2-octanediol, 1,9-nonanediol, 1,10-decanediol, neopentyl Glycol, 4-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, 2-methyl-1,8-octanediol, 2-isopropyl-1,4-butanediol, 2-ethyl-1 , 6-hexanediol, 3-methyl-1,5-pentanediol, 2,4-dimethyl-1,5-pentanediol, 2,4 Diethyl-1,5-pentanediol, 1,3-butanediol, 2-ethyl-1,3-hexanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-cyclohexanedimethanol, Examples include 1,3-cyclohexanediol and 1,4-cyclohexanediol. These diol compounds are used alone or in combination of two or more. Among these, from the viewpoint that crystallization hardly occurs, diol compounds include neopentyl glycol, 4-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, and 2-methyl-1,8-octane. Diol, 2-isopropyl-1,4-butanediol, 2-ethyl-1,6-hexanediol, 3-methyl-1,5-pentanediol, 2,4-dimethyl-1,5-pentanediol, and 2 It is preferably at least one selected from the group consisting of 2,4-diethyl-1,5-pentanediol. The carbonate is not particularly limited as long as the action and effect of the present invention are not impaired, and examples thereof include dialkyl carbonate, diaryl carbonate, and alkylene carbonate. Among these, the carbonate is preferably a diaryl carbonate from the viewpoint of reactivity. Specific examples of the carbonate compound include dimethyl carbonate, diethyl carbonate, dibutyl carbonate, diphenyl carbonate, ethylene carbonate and the like, and more preferably diphenyl carbonate. Commercially available polycarbonate diols include, for example, BENEBiOL series such as NL1010DB, NL2010DB, NL3010DB, NL1010B, NL2010B, NL3010B, NL1050DB, NL2050DB, NL3050DB of Mitsubishi Chemical Corporation, Durano series of Asahi Kasei Chemicals Corporation, Tosoh Corporation Nipporan series of company products, polyhexanediol carbonate of Kuraray Co., Ltd., Praxel series of Daicel Co., Ltd., "CDCD205PL", and ETERNACOLL series of Ube Industries, Ltd. products.

  When a polyol is used as a raw material for a polymer, it is preferable to use a polyol having an acid group in the molecule, and it is more preferable to use a carboxyl group-containing glycol. The carboxyl group-containing glycol is preferably one selected from the group consisting of dimethylolacetic acid, dimethylolpropionic acid, dimethylolbutanoic acid, and dimethylolbutyric acid, and is dimethylolpropionic acid and / or dimethylolbutanoic acid. Is more preferable, and dimethylolpropionic acid is further preferable. When the inkjet ink composition of the present embodiment is aqueous, it is preferable that the polymer use such an acid group-containing polyol as a raw material.

  When polyoxypropylene glycol and / or polycarbonate diol is used as a raw material of the polymer, the weight average molecular weight is preferably 500 or more and 3000 or less. When the weight average molecular weight is 500 or more, the density of urethane bonds in the polymer does not become too high, and the rigidity of a molecular chain derived from polyoxypropylene glycol and / or polycarbonate diol is suppressed. This enhances the flexibility of the polymer and further enhances the scratch resistance of the image. Further, since the weight average molecular weight of the polyoxypropylene glycol and / or polycarbonate diol that reacts with the polyisocyanate is 3000 or less, the density of urethane bonds in the polymer does not become too small, and the polyoxypropylene glycol and / or the polycarbonate diol does not become too small. The extensibility of the molecular chain derived from the polymer is not excessively increased, and the flexibility of the polymer is suppressed. Due to this, tack is less likely to occur, and the ink can ensure the scratch resistance of the image. Therefore, when the weight average molecular weight of the polyoxypropylene glycol and / or the polycarbonate diol is 500 or more and 3000 or less, the strength and flexibility of an image or a formed film formed by the polymer are improved, so that recording is performed. The scratch resistance of the image is further excellent.

  A polymer polymerized using such components is mainly composed of two types of segments, a hard segment and a soft segment. The hard segment is composed of a polyisocyanate, a short-chain polyol, a polyamine, a crosslinking agent, a chain extender, and the like, and mainly contributes to the strength of the polymer. On the other hand, the soft segment is composed of a long-chain polyol or the like, and mainly contributes to the flexibility of the resin. Then, the ink-jet ink composition is adhered to the recording medium, and the film formed of such a polymer has excellent strength and flexibility because these hard segments and soft segments have a microphase-separated structure. Has high elasticity. It is considered that such characteristics of the film contribute to further improving the scratch resistance of the recorded matter.

[1.1.2.3. Other starting materials)
(Polyamine)
In the inkjet ink composition of the present embodiment, the polymer preferably further contains a polyamine as a polymerization component. That is, it is preferable that the polymer raw material contained in the inkjet ink composition of the present embodiment contains a polyamine. The polyamine is not particularly limited as long as it is a compound having a bifunctional or higher amino group. Examples of the polyamine include ethylenediamine, propylenediamine, 2,2-dimethyl-1,3-propanediamine, 2-methyl-1,5-pentanediamine, trimethylhexanediamine, and 2-butyl-2-ethyl-1,5. -Aliphatic diamines such as pentanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, diethylenetriamine, hexylenediamine, triethylenetetramine, tetraethylenepentamine, isophoronediamine, xylylenediamine , Diphenylmethanediamine, hydrogenated diphenylmethanediamine, hydrazine, polyamidepolyamine, polyethylenepolyimine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, dicyclohexylmethanediamine , Bicycloheptane di methanamine, menthenediamine, diaminodicyclohexylmethane, isoproterenol kink Chin cyclohexyl-4,4'-diamine, 1,4-diaminocyclohexane, and 1,3-bis-aminomethyl cyclohexane and the like. Many of the compounds generally used as polyamines have a molecular weight equivalent to that of short-chain polyols, and are basically urea groups or biuret groups which are hard segments of a polymer.

  The polyamine is also used as a component that reacts with the polyfunctional polyisocyanate, a chain extender, a crosslinking agent, and the like, but a urea bond is formed when the isocyanate group and the amino group are reacted. Therefore, when a polyamine is used, the amount of urea group / urethane group in the polymer can be determined so that the ratio thereof becomes a desired ratio, and the physical properties of the polymer can be controlled. As a method of adjusting the ratio of urea group / urethane group in the polymer, for example, when synthesizing the polymer, a method of adjusting the amount used in consideration of the equivalent of the amino group of the polyamine compound, and a method of adjusting the polymer A method of adjusting the residual ratio of unreacted isocyanate groups when inverting the phase to water may be used. In the method of adjusting the amount of the polyamine used when synthesizing the polymer, the amount of the urea bond generated by the reaction between the polyamine and the isocyanate group is controlled. First, a plurality of types of polymers are synthesized with different amounts of the polyamine used, and the ratio of urea group / urethane group is calculated. From the obtained molar ratio, the relationship between the amount of the polyamine used and the molar ratio is examined to prepare a calibration curve, and this calibration curve is required to synthesize a polymer having a desired molar ratio. Determine the amount of polyamine used. Note that the calibration curve is prepared in advance because even if the same type of polyamine is used, the reaction rate and the like may change if other components are different. Therefore, a urea group / urethane group may be used between the raw material and the polymer. Are not the same molar ratio. As a method for adjusting the residual ratio of unreacted isocyanate groups when the polymer is converted to water, a method of synthesizing the polymer by a Fourier transform infrared spectrophotometer (FT-IR) may be used. Thus, the residual ratio of isocyanate groups to the used amount of polyisocyanate is confirmed. The residual ratio of isocyanate groups can be adjusted by changing the reaction time, the amount of polyisocyanate used, and the like.

(Crosslinking agent and chain extender)
The polymer of the present embodiment may be polymerized using a crosslinking agent and / or a chain extender. The crosslinking agent is used when synthesizing the prepolymer, and the chain extender is used when performing a chain extension reaction after synthesizing the prepolymer. The cross-linking agent or chain extender is appropriately selected from the above-mentioned polyisocyanates, polyols, polyamines and the like, depending on the use such as cross-linking and chain extension.

  The chain extender is, for example, a compound that reacts with an isocyanate group that does not form a urethane bond among the above-mentioned polyisocyanates. Examples of the compound used as a chain extender include the above-mentioned polyols and polyamines. As the chain extender, those capable of crosslinking a polymer are used. Examples of the compound used as a chain extender include low molecular weight polyols having a number average molecular weight of less than 500 and polyamines. Examples of the cross-linking agent include, among polyisocyanates, polyols, and polyamines, those having three or more functions. Examples of the trifunctional or higher polyfunctional polyisocyanate include a polyisocyanate having an isocyanurate structure, an allophanate and a polyisocyanate having a biuret structure. Polyols include, for example, glycerin, trimethylolpropane, pentaerythritol, and polyoxypropylene triol. Examples of the trifunctional or higher functional polyamine include amines having a trifunctional or higher functional amino group such as trialcoholamine such as triethanolamine and triisopropanolamine, and diethylenetriamine and tetraethylenepentamine. The presence or absence of cross-linking of the polymer is determined by the gel fraction calculated by calculating the ratio of the gel component and the sol component using a phenomenon in which the polymer having a cross-linked structure does not dissolve in the solvent and swells. be able to. The gel fraction is an index of the degree of crosslinking measured from the solubility of the solidified polymer, and the higher the degree of crosslinking, the higher the gel fraction.

(Other isocyanates)
In the polymer contained in the inkjet ink composition of the present embodiment, an isocyanate other than the specific polyisocyanate may be used as a raw material, as long as the above-described effects are not impaired. Such isocyanates include, for example, aliphatic polyisocyanates, aromatic polyisocyanates, and cycloaliphatic polyisocyanates. Examples of the aliphatic polyisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, and 2-methylpentane Polyisocyanates having a chain structure, such as -1,5-diisocyanate and 3-methyl-1,5-pentanediisocyanate. Further, an aromatic polyisocyanate may be used as a raw material of the polymer. Examples of the aromatic polyisocyanate include tolylene diisocyanate, 1,4-phenylene diisocyanate, and 1,5-naphthylene diisocyanate. When using an aromatic polyisocyanate, a blocked alicyclic polyisocyanate obtained by hydrogenating at least 80% of the aromatic rings of the aromatic polyisocyanate may be used. Examples of the alicyclic polyisocyanate include 1,4-cyclohexane diisocyanate and hydrogenated xylylene diisocyanate (hydrogenated XDI). By using these polyisocyanates, the strength of the formed film is increased, and the formed image tends to be more excellent in abrasion resistance. In particular, by using the alicyclic polyisocyanate, the film strength tends to be further increased, and the scratch resistance tends to be more excellent. In addition, these polyisocyanates may be used alone or in combination of two or more. Further, the polyisocyanate may have a structure formed from two or more molecules of polyisocyanate. Examples of the structure formed from two or more molecules of polyisocyanate include a uretdione structure and an isocyanurate structure. By using such a polyisocyanate, the polymer has a structure in which molecules are intricately entangled with each other and a state in which urethane bonds are densely packed. Therefore, for example, even if the acid value is low, the polyisocyanate can be more stably dispersed in the aqueous ink. Generally, the decrease in intermittent ejection stability is caused by evaporation of water from nozzles of an inkjet head. In order to increase the intermittent ejection stability, the pigment or resin aggregates even when water evaporates to some extent from the ink composition present near the nozzles of the inkjet head and the interaction between the polymer and the pigment becomes stronger. One of the factors is to maintain a stable and dispersed state. Although the polymer of the present embodiment has a relatively low acid value, it has a three-dimensionally complicated entangled structure by including the structure composed of the above-described polyisocyanate. , A repulsion due to an electrostatic action, a repulsive force or the like is easily generated, and a stable dispersion structure is easily obtained.

  In this specification, a polymer skeleton refers to a molecular chain between functional groups. Therefore, when the polymer of the present embodiment is a polyisocyanate, the functional group refers to an isocyanate group, when the polymer is a polyol, the functional group refers to a hydroxyl group, and when the polymer is a polyamine, the functional group refers to an amino group. Say. The skeleton is not particularly limited, but may include, for example, a substituted or unsubstituted saturated, unsaturated, or aromatic chain, and such a chain may have a carbonate bond, an ester bond, an amide bond, or the like. Good. The type and number of substituents in such a skeleton are not particularly limited, and such a skeleton may include an alkyl group, a hydroxyl group, a carboxyl group, an amino group, a sulfonyl group, and a phosphonyl group.

[1.1.3. Synthesis and analysis of polymer)
(Synthesis of polymer)
The polymer contained in the inkjet ink composition of the present embodiment can be synthesized using a known method for polymerizing a polymer. Hereinafter, an example will be described. The polyisocyanate is reacted with a compound that reacts with the polyisocyanate, such as a polyol or a polyamine, in a used amount such that the number of isocyanate groups is increased, thereby polymerizing a prepolymer having an isocyanate group at the terminal of the molecule. At this time, if necessary, an organic solvent having a boiling point of 100 ° C. or lower such as methyl ethyl ketone, acetone, and tetrahydrofuran may be used. This is generally called a prepolymer method.

  When an acid group-containing polyol is used as a raw material, an organic base such as N, N-dimethylethanolamine, N, N-diethylethanolamine, diethanolamine, triethanolamine, triisopropanolamine, trimethylamine, triethylamine, sodium hydroxide, The acid groups of the prepolymer are neutralized using a neutralizing agent such as an inorganic base such as potassium hydroxide or ammonia. Preferably, the dispersion stability of the polymer is further improved by using a neutralizing agent containing an alkali metal such as sodium hydroxide or potassium hydroxide. The amount of the neutralizing agent to be added is preferably 0.5 to 1.0 mol, more preferably 0.8 to 1.0 mol, per 1 mol of the acidic group of the prepolymer. This makes it difficult for the viscosity to increase, thereby improving workability. Thereafter, the prepolymer is added to a liquid containing a chain extender or a crosslinking agent, and a chain extension reaction or a crosslinking reaction is performed. Next, when an organic solvent is used, it is removed using an evaporator or the like to obtain a polymer dispersion.

  The catalyst used for the polymerization reaction of the polymer is preferably at least one selected from the group consisting of a titanium catalyst, an aluminum catalyst, a zirconium catalyst, an antimony catalyst, a germanium catalyst, a bismuth catalyst, and a metal complex catalyst. The titanium catalyst is preferably a tetraalkyl titanate such as tetrabutyl titanate or tetramethyl titanate, or a metal oxalate such as titanium potassium oxalate. The other catalyst is not particularly limited as long as it is a known catalyst, and examples thereof include tin compounds such as dibutyltin oxide and dibutyltin dilaurate. Examples of the non-heavy metal catalyst include acetylacetonate complexes of transition metals such as titanium, iron, copper, zirconium, nickel, cobalt, and manganese. These non-heavy metal catalysts have urethanizing activity. From the standpoint of increasing environmental awareness, low-toxicity catalysts that can replace heavy metal catalysts are desired. Among these, the catalysts are preferably titanium catalysts and / or zirconium catalysts.

(Analysis of polymer)
The composition of the polymer, the structure of the polyisocyanate, and the acid value of the polymer can be analyzed by the following methods.

  First, a method for extracting a polymer from an ink containing the polymer will be described. When the pigment is contained in the ink-jet ink composition, the polymer can be extracted from the ink-jet ink composition using an organic solvent (acetone, methyl ethyl ketone, etc.) that does not dissolve the pigment but dissolves the polymer. it can. Alternatively, the polymer can be extracted by fractionating the inkjet ink composition by ultracentrifugation and subjecting the supernatant to acid precipitation with an acid.

(A) Composition of polymer A polymer was dissolved in deuterated dimethyl sulfoxide (DMSO-d6) to prepare a sample, which was subjected to proton nuclear magnetic resonance ( ¹ H-NMR) or carbon-13 nuclear magnetic resonance ( ¹³ C-NMR). The type of polyisocyanate, polyol, polyamine, etc. can be confirmed from the position of the peak obtained by analysis by NMR). Further, the composition ratio can be calculated from the ratio of the integrated value of the peak of the chemical shift of each component. In addition, even when the polymer is analyzed by pyrolysis gas chromatography (GC-MS), the type of polyisocyanate, polyol, polyamine and the like can be confirmed. In addition, when the analysis is performed by carbon 13 nuclear magnetic resonance spectroscopy ( ¹³ C-NMR), the number of repeating unit units of the long-chain polyol is determined, and the number average molecular weight can be calculated.

(B) Structure of polyisocyanate The structure of the polyisocyanate can be confirmed from the infrared absorption spectrum obtained by analyzing the polymer by Fourier transform infrared spectroscopy (FT-IR). The main absorptions are as follows. Allophanate structure, NH stretching vibration absorption at 3300cm ^-1, 1750~1710cm ^-1, and two C = O stretching vibration absorption is present in 1708~1653cm ^-1. Uretdione structure, C = O stretching vibration absorption in 1780~1755cm ^-1, there are absorption based on uretdione ring 1420~1400cm ^-1. Isocyanurate structure, C = O stretching vibration absorption in 1720~1690cm ^-1, there are absorption based on isocyanurate ring 1428~1406cm ^-1. The biuret structure has C = O stretching vibration absorption at 1720 to 1690 cm ^-1 .

(C) Acid value of polymer The acid value of the polymer can be measured by a titration method. The acid value is measured by using AT610 (product name) manufactured by Kyoto Electronics Manufacturing Co. Ltd., and is calculated by applying a numerical value to the following equation (1).

Acid value (mg / g) = (EP1-BL1) × FA1 × C1 × K1 / SIZE (1)
In the above formula, EP1 is a titer (mL), BL1 is a blank value (0.0 mL), FA1 is a factor of the titrant (1.00), and C1 is a concentration conversion value (5.611 mg / mL) (0. 1 mo1 / L KOH 1 mL potassium hydroxide equivalent), K1 represents coefficient (1), and SIZE represents sampled amount (g), respectively.

  Then, the acid value of the polymer dissolved in tetrahydrofuran can be measured by colloid titration using a potential difference. At this time, an ethanol solution of sodium hydroxide can be used as a titration reagent.

[1.1.4. Polymer acid value)
Although the acid value of the polymer can be measured as described above, the acid value of the polymer of the present embodiment is 5 mgKOH / g to 50 mgKOH / g, and 5 mgKOH / g to 30 mgKOH / g. It is more preferably 7 mgKOH / g or more and 25 mgKOH / g or less, and still more preferably 8 mgKOH / g or more and 20 mgKOH / g or less. When the acid value is 5 mgKOH / g or more, the dispersion stability of the polymer in a water-based ink becomes good, and clogging hardly occurs even at a high temperature. On the other hand, when the content is 50 mgKOH / g or less, the polymer does not easily swell with water, and the ink does not easily increase in viscosity. Further, the water resistance of the recorded matter can be kept good.

  The acid value of the polymer can be changed, for example, by adjusting the content of a skeleton derived from a glycol containing a carboxyl group such as dimethylolpropionic acid. When the ink-jet ink composition of the present embodiment is an aqueous ink, it is preferable to use a carboxyl group-containing glycol as a polymer having a carboxyl group so that the ink can be easily dispersed in water.

[1.1.5. Content of Polymer] The inkjet ink composition of the present embodiment may contain a plurality of the above-described polymers. Further, the polymer may be added in the form of an emulsion. The total content of the polymer in the inkjet ink composition of the present embodiment is preferably 0.1% by mass or more and 20.0% by mass or less as a solid content, and is 1.0% by mass or more and 15.0% by mass. It is more preferred that:

[1.2. Other components)
[1.2.1. Pigment)
The inkjet ink composition of the present embodiment may contain a coloring material such as a pigment or a dye. The inkjet ink composition of the present embodiment can physically fix a coloring material to a recording medium by the above-described polymer. The coloring material is preferably a pigment. By attaching the pigment to the recording medium, a recorded matter having an image formed on the recording medium is obtained.

  The pigment is not particularly limited and includes, for example, inorganic pigments such as carbon black, calcium carbonate, and titanium oxide, azo pigments, isoindolinone pigments, diketopyrrolopyrrole pigments, phthalocyanine pigments, quinacridone pigments, and organic pigments such as anthraquinone pigments. Is mentioned. The pigment may be any of a black pigment, a white pigment, a yellow pigment, a cyan pigment, and a magenta pigment.

  As the black pigment, for example, 2300, no. 900, MCF88, No. 33, no. 40, no. 45, no. 52, MA7, MA8, MA100, No. Raven 5750, Raven 5250, Raven 5000, Raven 3500, Raven 1255, Raven 700 or the like (above, products of Columbia Carbon), Rega 400R, Rega 330R, Rega 660R, Mog , Monarch 700, Monarch 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, Monarch 1400, etc. (products of Cabot Corporation), Color Black FW1, Color Black FW1, Color Black FW1, Color Black FW1 Black FW20 Color B1ack S150, Color Black S160, Color Black S170, Printex 35, Printex U, Printex V, Printex 140U, Special Black 6, Products from Special Black 5 and Special Black 5 and Special Black 5 and Special Black 5 .

  Examples of the white pigment include C.I. I. Pigment White 1 (basic lead carbonate), 4 (zinc oxide), 5 (mixture of zinc sulfide and barium sulfate), 6 (titanium oxide), 6: 1 (titanium oxide containing other metal oxides), 7 (Zinc sulfide), 18 (calcium carbonate), 19 (clay), 20 (titanium mica), 21 (barium sulfate), 22 (natural barium sulfate), 23 (gloss white), 24 (alumina white), 25 (gypsum) ), 26 (magnesium oxide / silicon oxide), 27 (silica), 28 (anhydrous calcium silicate).

  Examples of the yellow pigment include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 16, 17, 24, 34, 35, 37, 53, 55, 65, 73, 74, 75, 81, 83, 93, 94, 95, 97, 98, 99, 108, 109, 110, 113, 114, 117, 120, 124, 128, 129, 133, 138, 139, 147, 151, 153, 154, 167, 172, and 180.

  Examples of the magenta pigment include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 40, 41, 42, 48 (Ca), 48 (Mn), 57 (Ca), 57: 1, 88, 112, 114, 122, 123, 144, 146, 149, 150, 166, 168 , 170, 171, 175, 176, 177, 178, 179, 184, 185, 187, 202, 209, 219, 224, 245, and C.I. I. Pigment Violet 19, 23, 32, 33, 36, 38, 43, 50.

  Examples of the cyan pigment include C.I. I. Pigment Blue 1, 2, 3, 15, 15: 1, 15: 2, 15: 3, 15:34, 15: 4, 16, 18, 22, 25, 60, 65, 66, and C.I. I. Bat Blue 4, 60.

  Examples of pigments other than black, white, yellow, magenta, and cyan include C.I. I. Pigment Green 7, 10 and C.I. I. Pigment Brown 3, 5, 25, 26, and C.I. I. Pigment Orange 1, 2, 5, 7, 13, 14, 15, 16, 24, 34, 36, 38, 40, 43, 63.

  The pigments exemplified above are surface-treated pigments in which an anionic group is bonded to the particle surface directly or through another atomic group, and at least pigments dispersed in a resin having an anionic functional group. Can be used as one.

  Examples of the pigment in which the anionic group is bonded to the particle surface directly or through another atomic group include, for example, those in which a functional group containing an anionic group is bonded to the surface of the pigment particle, and the pigment particle surface. One to which an anionic resin is bonded is exemplified. Examples of the pigment dispersed with a resin having an anionic functional group include, for example, those in which an anionic resin is physically adsorbed on the surface of pigment particles, those in which a pigment is included in an anionic resin, and the like. .

The self-dispersion pigment in which a functional group containing an anionic group is bonded to the surface of a pigment particle has an anionic group such as —COOM, —SO ₃ M, —PO ₃ HM, and —PO ₃ M ₂ that is attached to the surface of the pigment particle. Is bonded directly or via another atomic group. Examples of M include a hydrogen atom, and organic amines such as lithium, sodium, potassium, ammonium (NH ₄ ), methylamine, ethylamine, monoethanolamine, diethanolamine, and triethanolamine. Further, as other atomic groups, for example, a linear or branched alkylene group having 1 to 12 carbon atoms, a phenylene group, a naphthylene group, an amide group, a sulfonyl group, an amino group, a carbonyl group, an ester group, an ether group and Examples thereof include groups obtained by combining these groups.

  As these self-dispersed pigments, for example, those in which an anionic group is bonded to the surface of a pigment particle by an oxidation treatment by a known method, or a functional group containing an anionic group such as diazo coupling is bonded to the surface of the pigment particle And any of them can be suitably used. Self-dispersed pigment in which an anionic resin is bonded to the surface of pigment particles, a resin having at least a unit having an anionic group as a hydrophilic unit is bonded directly or through another atomic group to the surface of the pigment particles. It is.

  Both a resin dispersion pigment in which an anionic resin is physically adsorbed on the surface of pigment particles and a resin dispersion pigment in which a pigment is included in an anionic resin are both dispersion systems using a resin dispersant. As the resin dispersant, a copolymer having a hydrophilic group and a hydrophobic group is used.

  As the resin dispersant used for the self-dispersion pigment or the resin dispersion pigment, any of known resins that can be used for ink-jet inks can be used. As a suitable resin dispersant, the hydrophilic group preferably contains at least an anionic group. Examples of the hydrophilic group include those derived from a hydrophilic monomer such as (meth) acrylic acid or a salt thereof. Examples of the hydrophobic group include hydrophobic monomers such as styrene and derivatives thereof, monomers having an aromatic ring such as benzyl (meth) acrylate, and monomers having an aliphatic group such as (meth) acrylate. Functional groups and the like.

  The resin used as the resin dispersant has a weight average molecular weight of 10,000 to 100,000, more preferably 30,000 to 80,000, and an acid value of 50 mgKOH / g to 150 mgKOH / g. Are preferred. In the present embodiment, it is more preferable to use a styrene- (meth) acrylic resin or a (meth) acrylic resin having an acid value of 50 mgKOH / g to 150 mgKOH / g as a dispersant. When a dispersion method using a dispersant is used, the mass ratio of the resin dispersant / pigment is preferably 0.1 times or more and 10.0 times or less, and more preferably 0.5 times or more and 5.0 times or less.

  In the case where the inkjet ink composition of the present embodiment is to be attached to a recording medium such as a transparent or translucent film, if an inorganic pigment (white pigment) is used, an underlayer having excellent fixability and abrasion resistance ( (A first layer described later) can be formed. With such an underlayer, a recorded matter having good background shielding properties can be created.

  These pigments are used alone or in combination of two or more. The total content of the pigment (solid content) in the inkjet ink composition varies depending on the type of pigment used. From the viewpoint of obtaining good color developability, the total content is preferably from 0.1% by mass to 15.0% by mass, when the total mass of the inkjet ink composition is 100% by mass, More preferably, the content is 1.0% by mass or more and 10.0% by mass or less.

  In preparing the inkjet ink composition, a pigment dispersion in which a pigment is dispersed in advance may be prepared, and the pigment dispersion may be added to the inkjet ink composition. As a method of obtaining such a pigment dispersion, for example, a method of dispersing a self-dispersion pigment in a dispersion medium without using a dispersant, or a method of dispersing a pigment into a dispersion medium by using a polymer dispersant (resin dispersant). A method of dispersing, a method of dispersing a surface-treated pigment in a dispersion medium, and the like can be given.

[1.2.2. water〕
The inkjet ink composition according to the embodiment may include water. Examples of the water include pure water such as ion-exchanged water, ultrafiltration water, reverse osmosis water, and distilled water, and water from which ionic impurities such as ultrapure water have been removed as much as possible. When water sterilized by ultraviolet irradiation or addition of hydrogen peroxide is used, the generation of bacteria and fungi can be prevented when the inkjet ink composition is stored for a long period of time.

  The water content is 30% by mass or more, preferably 40% by mass or more, more preferably 45% by mass or more, and still more preferably 50% by mass, when the total mass of the inkjet ink composition is 100% by mass. % By mass or more. The water in the ink-jet ink composition includes, for example, water from a polymer particle dispersion, a pigment dispersion, and water to be added as raw materials. When the content of water is 30% by mass or more, the viscosity of the inkjet ink composition can be relatively low. The upper limit of the water content is preferably 90% by mass or less, more preferably 85% by mass or less, and further preferably 80% by mass, when the total mass of the inkjet ink composition is 100% by mass. % Or less.

  The inkjet ink composition of the present embodiment is more preferably an aqueous ink containing water. As a result, the polymer is easily dispersed in the form of an emulsion, and an image having more excellent fixability and scratch resistance can be easily formed by the inkjet method.

[1.2.3. (Water-soluble organic solvent)
The inkjet ink composition of the present embodiment may include a water-soluble organic solvent. By including the water-soluble organic solvent, the ejection stability of the ink-jet ink composition by the ink-jet method is further excellent, and the evaporation of water from the recording head during long-term storage can be effectively suppressed.

  The water-soluble organic solvent is not particularly limited as long as it has water solubility. For example, monohydric or polyhydric alcohol, (poly) alkylene glycol, glycol ether, ε-caprolactam, 2-pyrrolidone, N-methyl- Nitrogen-containing polar solvents such as lactams such as pyrrolidone, lactones such as ε-caprolactone and δ-valerolactone, and sulfur-containing polar solvents such as dimethylsulfoxide (DMSO), acetin, and diacetin are used. Among these, the water-soluble organic solvent is preferably 2-pyrrolidone having a lactam structure. The content (% by mass) of the water-soluble organic solvent in the inkjet ink composition is 3.0% by mass or more and 50.0% by mass or less when the total mass of the inkjet ink composition is 100% by mass. Is preferred.

[1.2.4. (Surfactant)
The inkjet ink composition of the present embodiment may include a surfactant. Examples of the surfactant include a nonionic surfactant, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and the like. The surfactants may be used alone or in combination of two or more.

  When a surfactant is added to the inkjet ink composition, the content of the surfactant is, for example, 0.01% by mass or more and 3% by mass or less when the total mass of the inkjet ink composition is 100% by mass. , Preferably from 0.05% by mass to 2% by mass, more preferably from 0.1% by mass to 1% by mass, particularly preferably from 0.2% by mass to 0.5% by mass. is there.

  When the inkjet ink composition contains a surfactant, the stability when the ink is ejected from the head tends to be further increased.

[1.2.5. Chelating agent)
The inkjet ink composition of the present embodiment may include a chelating agent. Chelating agents have the property of trapping ions. Such chelating agents include, for example, ethylenediaminetetraacetic acid salt (EDTA), nitrilotriacetic acid salt of ethylenediamine, hexametaphosphate, pyrophosphate, or metaphosphate.

[1.2.6. Preservative〕
The inkjet ink composition of the present embodiment may contain a preservative. By containing a preservative, the growth of mold and bacteria can be suppressed, and the ink-jet ink composition tends to be more excellent in storage stability. This makes it easier to use, for example, the inkjet ink composition as a maintenance liquid for long-term maintenance without using a printer. Preferred examples of the preservative include Proxel CRL, Proxel BDN, Proxel GXL, Proxel XL-2, Proxel IB, and Proxel TN (these are the product names of Lonza).

[1.2.7. pH adjuster)
The inkjet ink composition of the present embodiment may contain a pH adjuster. By containing a pH adjuster, for example, elution of impurities from a member forming the ink flow path can be suppressed or accelerated, and the cleaning property of the inkjet ink composition can be adjusted. Examples of the pH adjuster include morpholines, piperazines, amino alcohols such as triethanolamine, and the like.

[1.2.8. Other components)
The inkjet ink composition of the present embodiment further comprises, if necessary, a polyhydric alcohol such as trimethylolpropane and trimethylolethane, and a urea derivative such as urea and ethylene urea. May be contained. The inkjet ink composition of the present embodiment further contains, if necessary, various additives such as a rust inhibitor, a fungicide, an antioxidant, a reduction inhibitor, an evaporation promoter and a water-soluble resin. Is also good.

[1.3. Method for producing inkjet ink composition]
The method for producing the inkjet ink composition of the present embodiment is not particularly limited, but for example, it can be produced as follows. In addition, the inkjet ink composition of the present embodiment is not limited to one obtained by the following manufacturing method. First, when polymerizing a polymer, the polymer is reacted in a solvent containing 2-pyrrolidone to obtain dicyclohexylmethane diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, m-bis (isocyanatopropyl) benzene, and m-bis (isocyanatopropyl) benzene. Forming a polymer having at least one selected from bis (isocyanatomethyl) benzene and a urethane group or a urea group derived from a polyolefin polyol; Then, the obtained polymer dispersion or polymer solution and each of the above-mentioned components are mixed in an arbitrary order, and if necessary, filtration can be performed to remove impurities by removing the impurities. As a mixing method of each component, a method of sequentially adding materials to a container equipped with a stirrer such as a mechanical stirrer and a magnetic stirrer and stirring and mixing them is preferably used. When manufactured in this way, 2-pyrrolidone can be used by remaining as a component of the ink-jet ink composition, so that the solvent can be effectively used, and in addition to the case where a solvent having a standard boiling point of 100 ° C. or lower is used, For example, when the ink-jet ink composition is attached to a recording medium such as a film, an image having excellent glossiness can be easily obtained.

[1.3. Physical properties of inkjet ink composition)
[1.4. Action and effect)
According to the inkjet ink composition of the present embodiment, by adding the above-described polymer, the scratch resistance of the recorded image can be improved, and the clogging property and the intermittent ejection stability can be maintained high. The intermittent ejection stability is related to the acid value of the polymer. If the acid value is high, the hydrophilicity of the polymer increases, and the intermittent ejection stability improves. However, if the acid value of the polymer is too high, the stability of intermittent ejection is improved, but the scratch resistance and water resistance of the recorded image tend to decrease. Further, depending on the mode in which the polymer is contained in the inkjet ink composition, the intermittent ejection stability of the ink is reduced.

  In general, the decrease in intermittent ejection stability is caused by evaporation of water from nozzles of an inkjet head. In order to improve the intermittent ejection stability, even when water evaporates to some extent from the ink near the nozzles of the inkjet head and the interaction between the polymer and the pigment is strengthened, the pigment or resin does not agglomerate. It is necessary to maintain a stable dispersion state.

  The polymer contained in the ink-jet ink composition of the present embodiment has a relatively low acid value, but has a three-dimensionally intertwined structure, so that even when the evaporation of water progresses, the polymer and the pigment remain between the polymer and the pigment. Repulsion due to electrostatic action or repulsion is likely to occur. Thereby, the ink-jet ink composition of the present embodiment improves the abrasion resistance of the recorded matter and keeps the dispersion state of the pigment stable, so that the clogging stability and the intermittent ejection stability can be improved.

  Furthermore, by appropriately blending an isocyanate, such as a polymer contained in the ink-jet ink composition of the present embodiment, the glossiness when applied to a recording medium having high flatness such as a film is improved.

  Since the polymer is mainly composed of a polyisocyanate and a component that reacts with the polymer, if the acid value of the polymer is increased to improve the intermittent ejection stability of the inkjet ink composition, a short chain such as an acid group-containing diol is used. The proportion occupied by the polyol will be increased. Then, the proportion occupied by the long-chain polyol, which is a target component that reacts with the polyisocyanate similarly to the short-chain polyol, decreases. In this case, the urethane bond in the polymer increases and the soft segment decreases, and the flexibility of the polymer film is impaired. Therefore, if the hydrophilicity of the polymer is increased by increasing the acid value of the polymer, the intermittent ejection stability of the inkjet ink composition is improved, but the scratch resistance and water resistance of the image are reduced.

  For the polymer contained in the ink-jet ink composition of the present embodiment, instead of increasing the acid value to increase the hydrophilicity of the polymer, the ink value is set to 5 to 50 mgKOH / g and the ink jet ink is reduced to some extent. Intermittent ejection stability of the composition is ensured. The polymer is polymerized using a raw material containing a specific diisocyanate to improve the scratch resistance of an image, and has a sufficient gloss even when used for a recording medium requiring gloss such as a film. Is obtained.

[2. Recording method〕
[2.1. recoding media〕
The inkjet recording method of the present embodiment performs recording on a recording medium using the inkjet ink composition of the present embodiment. The inkjet recording method includes an ejection step of ejecting the inkjet ink composition of the present embodiment onto a recording medium. Hereinafter, an example of a recording medium used with the recording method according to the present embodiment will be described.

The recording medium used in the recording method of the present embodiment is not particularly limited, and various recording media such as plain paper, glossy paper, cloth, non-absorbing or slightly absorbing recording medium can be used. Alternatively, it is preferable that the recording medium has slight absorbency. The non-absorptive or micro-absorptive recording medium refers to a recording medium having a property of absorbing no or almost no ink. Quantitatively, the non-absorbing or slightly absorbing recording medium refers to a “recording medium having a water absorption of 10 mL / m ² or less from the start of contact to 30 msec ^1/2 in the Bristow method”. Say. The Bristow method is the most widespread method for measuring the amount of liquid absorbed in a short time, and is also adopted by the Japan Pulp and Paper Technology Association (JAPAN TAPPI). Details of the test method are described in the standard No. of “JAPAN TAPPI Paper and Pulp Test Method 2000 Edition”. 51 "Paper and paperboard-Liquid absorbency test method-Bristow method". Examples of the recording medium having such non-absorbing or slightly absorbing properties include, for example, a recording medium having no ink-absorbing ink-receiving layer on the recording surface and a coating layer having a small ink-absorbing property on the recording surface. Recording medium provided.

  The non-absorbent recording medium is not particularly limited. For example, a plastic film having no ink absorbing layer, a plastic coated on a base material such as paper, or a plastic film is adhered. And the like. Examples of the plastic here include polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, and polypropylene.

  The recording medium having a slight absorbency is not particularly limited, and examples thereof include a coated paper having a surface provided with a coating layer for receiving oil-based ink. Examples of the coated paper include, but are not particularly limited to, printing paper such as art paper, coated paper, and mat paper.

  The use of the inkjet ink composition of the present embodiment makes it easier to form a predetermined image having good fixability and good abrasion resistance even on a recording medium having such non-absorptive or micro-absorptive properties. can do.

  In the recording method of the present embodiment, it is more preferable that the recording medium to which the recording medium is to be adhered contains polyolefin (polyethylene, polypropylene, or the like) as a main component. Such a recording medium is generally a recording medium that is difficult to adhere to, and can form an image with good fixability and abrasion resistance, and therefore has good fixability and abrasion resistance. The effect of having is more remarkable.

[2.2. Recording method〕
The recording method according to the present embodiment uses the above-described inkjet ink composition. According to such a recording method, for example, when forming an image layer by discharging an inkjet ink composition from an inkjet head onto a recording medium, intermittent ejection stability is ensured, and image fixability and scratch resistance are ensured. It is possible to obtain an image having both characteristics.

  The recording method of the present embodiment is a method of recording an image on a recording medium by discharging the above-described inkjet ink composition of the present embodiment from an inkjet recording head. Examples of a method of ejecting ink include a method of applying mechanical energy to the ink by an electrostrictive element and a method of applying thermal energy to the ink. In the present embodiment, it is particularly preferable to use a method of applying mechanical energy to the ink by an electrostrictive element.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.However, the present invention can be variously modified without departing from the gist thereof, and is not limited by the following Examples. . In addition, what described as% with respect to the component amount is mass% unless otherwise specified.

[3.1. Preparation of urethane resin emulsion)
<Preparation of urethane resin emulsion A1>
In a reaction vessel into which a stirrer, a reflux condenser and a thermometer were inserted, 1500 g of GI-2000 (trade name, manufactured by Nippon Soda Co., Ltd.), 220 g of 2,2-dimethylolpropionic acid (DMPA) and 2-pyrrolidone (boiling point: 245) 1347 g) in a nitrogen stream and heated to 60 ° C. to dissolve DMPA. To the reaction vessel, 1300 g of 4,4'-dicyclohexylmethane diisocyanate and 2.6 g of a urethanation catalyst XK-614 (manufactured by Kusumoto Kasei) were added, and the mixture was heated to 90 ° C., and a urethanization reaction was carried out for 5 hours. A urethane prepolymer was obtained.
Next, the reaction mixture was cooled to 80 ° C., and 4340 g of the mixture obtained by adding and mixing 220 g of triethanolamine was added to a mixed solution of 5400 g of water and 22 g of triethanolamine under vigorous stirring. Was. Then, 1500 g of ice was charged, and 1084 g of a 35% by mass aqueous solution of bicycloheptanedimethanamine was added to carry out a chain extension reaction. The solvent was distilled off so that the solid content concentration became 30%, and the urethane resin emulsion A (urethane Resin component 30%, water 64%, 2-pyrrolidone 6%, acid value 18 mgKOH / g) were obtained.

<Preparation of urethane resin emulsion A2>
In the production of the urethane resin emulsion A1, 1100 g of isophorone diisocyanate was used instead of 1300 g of 4,4′-dicyclohexylmethane diisocyanate, and the charged amount of GI-2000 (trade name: manufactured by Nippon Soda Co., Ltd.) was changed to 1500 g instead of 1500 g, A urethane resin emulsion A2 (30% urethane resin component, 64% water, 6% 2-pyrrolidone, acid value 18 mg KOH / g) was obtained in the same manner except that 500 g of the polycarbonate diol a obtained by the production method described below was used.

<Preparation of urethane resin emulsion A3>
In the production of the urethane resin emulsion A1, a urethane resin emulsion A3 (30% of a urethane resin component, 30% of urethane resin components) was used in the same manner except that 950 g of 1,3-bis (isocyanatomethyl) cyclohexane was used instead of 1300 g of 4,4′-dicyclohexylmethane diisocyanate. Water 64%, 2-pyrrolidone 6%, acid value 18 mgKOH / g) were obtained.

<Preparation of urethane resin emulsion A4>
In the production of the urethane resin emulsion A1, a urethane resin emulsion A4 (30% urethane resin component, 64% water) was used in the same manner except that 1,070 g of m-bis (isocyanatopropyl) benzene was used instead of 1,300 g of 4,4′-dicyclohexylmethane diisocyanate. %, 2-pyrrolidone 6%, acid value 18 mgKOH / g).

<Preparation of urethane resin emulsion A5>
In the production of the urethane resin emulsion A1, a urethane resin emulsion A5 (30% urethane resin component, water 64%) was used in the same manner except that 930 g of m-bis (isocyanatomethyl) benzene was used instead of 1300 g of 4,4′-dicyclohexylmethane diisocyanate. %, 2-pyrrolidone 6%, acid value 18 mgKOH / g).

<Preparation of urethane resin emulsion A6>
In the production of the urethane resin emulsion A1, instead of 1300 g of 4,4′-dicyclohexylmethane diisocyanate, 1400 g of polyisocyanate A obtained by the production method described below was used, and instead of 1500 g of GI-2000 (trade name, manufactured by Nippon Soda Co., Ltd.) Resin emulsion A6 (urethane resin component 30%, water 64%, 2-pyrrolidone 6%, acid value 18 mg KOH / g) except that 2250 g of GI-3000 (trade name, manufactured by Nippon Soda Co., Ltd.) was used. I got

<Preparation of urethane resin emulsion A7>
In the production of the urethane resin emulsion A1, a urethane resin emulsion A7 (30% urethane resin component, urethane resin emulsion A7) was used in the same manner except that 1,20 g of polyisocyanate B obtained by a production method described below was used instead of 1,300 g of 4,4′-dicyclohexylmethane diisocyanate. Water 64%, 2-pyrrolidone 6%, acid value 18 mgKOH / g) were obtained.

<Preparation of urethane resin emulsion A8>
In the production of the urethane resin emulsion A3, the same procedure was performed except that the charged amount of GI-2000 (trade name: manufactured by Nippon Soda Co., Ltd.) was changed to 1500 g instead of 1500 g, and 500 g of polyoxypropylene glycol (number average molecular weight 2000) was used. Thus, a urethane resin emulsion A8 (urethane resin component 30%, water 64%, 2-pyrrolidone 6%, acid value 18 mgKOH / g) was obtained.

<Preparation of urethane resin emulsion A9>
In the production of the urethane resin emulsion A4, the charge amount of GI-2000 (trade name: manufactured by Nippon Soda Co., Ltd.) was changed to 1500 g instead of 1500 g, and 1070 g of m-bis (isocyanatopropyl) benzene was used. A urethane resin emulsion A9 (30% urethane resin component, 64% water, 6% 2-pyrrolidone, acid value 18 mg KOH) was prepared in the same manner except that 300 g of the obtained polycarbonate diol a and 200 g of polyoxypropylene glycol (number average molecular weight 2000) were used. / G).

<Preparation of urethane resin emulsion A10>
In the production of the urethane resin emulsion A2, a urethane resin emulsion A10 (30% urethane resin component, 64% water, 2% water) was used in the same manner except that 930 g of 1,3-bis (isocyanatomethyl) cyclohexane was used instead of 1100 g of isophorone diisocyanate. 6% of pyrrolidone and an acid value of 18 mg KOH / g) were obtained.

<Preparation of urethane resin emulsion A11>
In the production of the urethane resin emulsion A10, GI-30002100 g and trimethylolpropane 5 g were used instead of 1000 g of GI-2000 (trade name: manufactured by Nippon Soda Co., Ltd.) and 500 g of polycarbonate diol a obtained by the production method described below. Similarly, a urethane resin emulsion A11 (urethane resin component 30%, water 64%, 2-pyrrolidone 6%, acid value 18 mgKOH / g) was obtained.

<Preparation of urethane resin emulsion A12>
In the production of the urethane resin emulsion A11, the charge amount of GI-3000 (trade name: manufactured by Nippon Soda Co., Ltd.) was changed to 2,100 g to 2050 g, and the same procedure was performed except that 10 g of triethylene glycol was used. Resin component 30%, water 64%, 2-pyrrolidone 6%, acid value 18 mgKOH / g) were obtained.

<Preparation of urethane resin emulsion A13>
In the production of Resin Emulsion A4, urethane resin emulsion A13 (30% urethane resin component, 64% water, 30% urethane resin component) was used in the same manner except that 990 g of 2,4-tolylene diisocyanate was used instead of 1070 g of m-bis (isocyanatomethyl) benzene. 6% of 2-pyrrolidone and an acid value of 18 mgKOH / g) were obtained.

<Preparation of urethane resin emulsion A14>
In the production of the resin emulsion A4, a urethane resin emulsion A14 (30% urethane resin component, 64% water, 30% urethane resin component) was used in the same manner except that 1420 g of 4,4′-diphenylmethane diisocyanate was used instead of 1070 g of m-bis (isocyanatomethyl) benzene. 6% of 2-pyrrolidone and an acid value of 18 mgKOH / g) were obtained.

<Preparation of urethane resin emulsion A15>
In the production of Resin Emulsion A4, urethane resin emulsion A15 (30% urethane resin component, 64% water, except that 960 g of 1,6-hexamethylene diisocyanate was used instead of 1070 g of m-bis (isocyanatomethyl) benzene. 6% of 2-pyrrolidone and an acid value of 18 mgKOH / g) were obtained.

<Preparation of urethane resin emulsion A16>
In the production of resin emulsion A4, urethane resin emulsion A16 (urethane resin emulsion A16) was prepared in the same manner except that 880 g of 4,4′-diphenylmethane diisocyanate and 370 g of 1,6-hexamethylene diisocyanate were used instead of 1070 g of m-bis (isocyanatomethyl) benzene. Resin component 30%, water 64%, 2-pyrrolidone 6%, acid value 18 mgKOH / g) were obtained.

<Preparation of urethane resin emulsion A17>
In the production of resin emulsion A5, urethane resin emulsion A17 (urethane resin component) was prepared in the same manner except that 50 g of 2,2-dimethylolpropionic acid (DMPA) was used instead of 220 g of 2,2-dimethylolpropionic acid (DMPA). 30%, water 64%, 2-pyrrolidone 6%, acid value 4 mgKOH / g).

<Preparation of urethane resin emulsion A18>
In the production of resin emulsion A5, urethane resin emulsion A18 (urethane resin component) was prepared in the same manner except that 630 g of 2,2-dimethylolpropionic acid (DMPA) was used instead of 220 g of 2,2-dimethylolpropionic acid (DMPA). 30%, water 64%, 2-pyrrolidone 6%, acid value 32 mgKOH / g).

<Preparation of urethane resin emulsion A19>
In the production of the urethane resin emulsion A3, a urethane resin emulsion A19 (urethane) was prepared in the same manner except that 1500 g of polyoxypropylene glycol (number average molecular weight 2000) was used instead of 1500 g of GI-2000 (trade name: manufactured by Nippon Soda Co., Ltd.). Resin component 30%, water 64%, 2-pyrrolidone 6%, acid value 18 mgKOH / g) were obtained.

<Preparation of urethane resin emulsion A20>
In the production of the urethane resin emulsion A4, a urethane resin emulsion A20 (urethane resin emulsion A20) was prepared in the same manner except that 1500 g of a polycarbonate diol a obtained by a production method described below was used instead of 1500 g of GI-2000 (trade name: manufactured by Nippon Soda Co., Ltd.). Resin component 30%, water 64%, 2-pyrrolidone 6%, acid value 18 mgKOH / g) were obtained.

<Preparation of urethane resin emulsion A21>
In the production of the urethane resin emulsion A4, instead of 1500 g of GI-2000 (trade name, manufactured by Nippon Soda Co., Ltd.), 1000 g of polyoxypropylene glycol (number average molecular weight 2000) and 500 g of polycarbonate diol a obtained by the production method described below were used. A urethane resin emulsion A21 (30% urethane resin component, 64% water, 6% 2-pyrrolidone, acid value 18 mg KOH / g) was obtained in the same manner except for using.

<Preparation of urethane resin emulsion A22>
In the production of the urethane resin emulsion A5, 1347 g of methyl ethyl ketone (boiling point: 79.6 ° C.) was used instead of 1347 g of 2-pyrrolidone (boiling point: 245 ° C.), and the solvent was distilled off so that the solid content concentration became 30%. A urethane resin emulsion A22 (30% urethane resin component, 70% water, acid value 18 mgKOH / g) was obtained.

<Preparation of urethane resin emulsion A23>
In the production of the urethane resin emulsion A6, 1347 g of methyl ethyl ketone (boiling point: 79.6 ° C.) was used instead of 1347 g of 2-pyrrolidone (boiling point: 245 ° C.), and the solvent was distilled off so that the solid content concentration became 30%. A urethane resin emulsion A23 (urethane resin component 30%, water 70%, acid value 18 mgKOH / g) was obtained.

<Preparation of urethane resin emulsion A24>
In the production of the urethane resin emulsion A9, 1347 g of methyl ethyl ketone (boiling point: 79.6 ° C.) was used instead of 1347 g of 2-pyrrolidone (boiling point: 245 ° C.), and the solvent was distilled off so that the solid content concentration became 30%. A urethane resin emulsion A24 (30% urethane resin component, 70% water, acid value 18 mgKOH / g) was obtained.

<Preparation of urethane resin emulsion A25>
In the production of the urethane resin emulsion A13, 1347 g of methyl ethyl ketone (boiling point: 79.6 ° C.) was used instead of 1347 g of 2-pyrrolidone (boiling point: 245 ° C.), and the solvent was distilled off so that the solid content concentration became 30%. A urethane resin emulsion A25 (urethane resin component 30%, water 70%, acid value 18 mgKOH / g) was obtained.

<Preparation of urethane resin emulsion A26>
In the production of the urethane resin emulsion A16, 1347 g of methyl ethyl ketone (boiling point: 79.6 ° C.) was used instead of 1347 g of 2-pyrrolidone (boiling point: 245 ° C.), and the solvent was distilled off so that the solid content concentration became 30%. A urethane resin emulsion A25 (urethane resin component 30%, water 70%, acid value 18 mgKOH / g) was obtained.

[3.2. Production of raw materials for urethane resin]
<Production of polycarbonate diol a>
In a 1-L glass separable flask equipped with a stirrer, a distillate trap, and a pressure controller, 1,6-hexanediol (1,6-HD): 123 g, diphenyl carbonate: 203 g, and magnesium acetate 4 water were used as raw materials. Japanese product: 4.4 mg was added, and the atmosphere was replaced with nitrogen gas. Under stirring, the internal temperature was raised to 160 ° C to 170 ° C, and the contents were heated and dissolved. Then, after reducing the pressure from the atmospheric pressure to 26 kPa, the reaction was carried out for 100 minutes while removing the by-product phenol out of the system. Next, the pressure was reduced to 0.6 kPa, and the reaction was continued. Then, the temperature was increased to 180 ° C., and the reaction was carried out for 100 minutes while removing the by-product phenol and unreacted dihydroxy compound out of the system. Was obtained. The number average molecular weight in terms of styrene was measured using gel permeation chromatography (GPC) of an L7100 system manufactured by Hitachi, Ltd., using THF as a solvent, and was found to be 2,000.

<Synthesis of polyisocyanate A>
In a reactor equipped with a stirrer, a thermometer, a cooler, and a nitrogen gas inlet tube, under a nitrogen atmosphere, 186.0 parts of 4,4'-dicyclohexylmethane diisocyanate, 14.0 parts by mass of isopropyl alcohol, and Then, 1 part of dibutyltin oxide was added and reacted at a temperature of 80 ° C. for 2 hours to urethanate, thereby obtaining a reaction solution. To the obtained reaction solution, 0.01 parts of zirconium 2-ethylhexanoate (allophanate-forming catalyst) was added and reacted at a temperature of 110 ° C to obtain a reaction solution. The unreacted 4,4'-dicyclohexylmethane diisocyanate was removed by distilling the obtained reaction solution with a thin-film distillation apparatus to obtain polyisocyanate A. The isocyanate group content was adjusted to 20.0% by mass.

<Synthesis of polyisocyanate B>
In a reactor equipped with a stirrer, thermometer, condenser and nitrogen gas inlet tube, under a nitrogen atmosphere, 186.0 parts of 1,3-bis (isocyanatomethyl) cyclohexane 14.0 parts of isopropyl alcohol, Then, 1 part of dibutyltin oxide was added and reacted at a temperature of 80 ° C. for 2 hours to urethanate, thereby obtaining a reaction solution. To the obtained reaction solution, 0.01 parts of zirconium 2-ethylhexanoate (allophanate-forming catalyst) was added and reacted at a temperature of 110 ° C to obtain a reaction solution. Unreacted hydrogenated xylylene diisocyanate was removed by distilling the obtained reaction solution with a thin-film distillation apparatus to obtain polyisocyanate B. The isocyanate group content was adjusted to 20.0%.

The polyol and polyisocyanate used for each urethane resin emulsion are shown below.
GI-2000 (trade name: manufactured by Nippon Soda Co., Ltd.)
GI-3000 (trade name: manufactured by Nippon Soda Co., Ltd.)
Polycarbonate diol a: PCDa
Trimethylolpropane: TMP
Triethylene glycol: TEG
Polyoxypropylene glycol (Mn2000): PPG2000
4,4'-Dicyclohexylmethane diisocyanate: MCHDI
Isophorone diisocyanate: IPDI
1,3-bis (isocyanatomethyl) cyclohexane: BIMCH
m-bis (isocyanatomethyl) benzene: BICMB
m-bis (isocyanatopropyl) benzene: BICPB
Polyisocyanate A: PICA
Polyisocyanate B: PICB
2,4-tolylene diisocyanate: TDI
4,4'-diphenylmethane diisocyanate: MDI
1,6-hexamethylene diisocyanate: HDI

[3.3. Preparation of pigment dispersion)
(Pigment dispersion liquid 1)
500 g of ion-exchanged water and 15 g of carbon black were mixed and stirred for 30 minutes using a rocking mill using 1 mm zirconia beads to pre-wet the pigment. 4485 g of ion-exchanged water was added thereto and dispersed with a high-pressure homogenizer. At this time, the average particle size of the pigment was 110 nm. This was transferred to a high-pressure container and pressurized at a pressure of 3 MPa. Then, ozone water having an ozone concentration of 100 ppm was introduced to perform an ozone oxidation treatment on the surface of the pigment. Thereafter, the pH of this dispersion was adjusted to 9.0 using a 0.1 mol / L aqueous sodium hydroxide solution, and then the concentration of the pigment solid was adjusted to obtain Pigment Dispersion 1. Pigment Dispersion Liquid 1 contained a self-dispersion pigment in which a -COONa group was bonded to the particle surface, and the content of the pigment was 30%.

(Pigment dispersion liquid 2)
500 g of carbon black, 1000 g of a water-soluble resin, and 14000 g of water were mixed to obtain a mixture. As the water-soluble resin, a resin obtained by neutralizing a styrene-acrylic acid copolymer having an acid value of 100 mgKOH / g and a weight average molecular weight of 10,000 with a 0.1 mol / L aqueous sodium hydroxide solution was used. After this mixture was dispersed for 1 hour using a rocking mill using 1 mm zirconia beads, impurities were removed by centrifugation, and the mixture was filtered under reduced pressure using a microfilter (manufactured by Millipore) having a pore size of 5.0 μm. Next, the concentration of the pigment solids was adjusted to obtain a pigment dispersion liquid 2 having a pH of 9.0. Pigment Dispersion Liquid 2 contained a pigment dispersed with a water-soluble resin (resin dispersant). The pigment content was 30.0%, and the resin content was 15.0%.

(Pigment dispersion 3)
After a reaction vessel equipped with a stirrer, a thermometer, a reflux tube, and a dropping funnel was purged with nitrogen, 300 parts by mass of methyl ethyl ketone was charged, 40 parts by mass of styrene, 40 parts by mass of ethyl methacrylate, 5 parts by mass of lauryl acrylate, and 5 parts by mass of lauryl methacrylate. Methoxypolyethylene glycol 400 acrylate AM-90G (manufactured by Shin-Nakamura Chemical Co., Ltd.), 5 parts by mass of acrylic acid, 0.2 parts by mass of ammonium persulfate, and 0.3 parts by mass of t-dodecylmercaptan were put into a dropping funnel. The polymer dispersant was allowed to undergo a polymerization reaction while being dropped into the reaction vessel over 4 hours. Thereafter, methyl ethyl ketone was added to the reaction vessel to prepare a 40% by mass polymer dispersant solution.

  The weight average molecular weight in terms of styrene of the polymer dispersant solution was measured using gel permeation chromatography (GPC) of L7100 system manufactured by Hitachi, Ltd., using THF as a solvent, and was found to be 58,000. The value of polydispersity (Mw / Mn) was 3.1.

  40 parts by mass of the polymer dispersant solution and Chromofine Blue as a cyan pigment. I. Pigment Blue 15: 3 (manufactured by Dainichi Seika Kogyo Co., Ltd., trade name; hereinafter also referred to as “PB15: 3”) 30 parts by mass, 100 parts by mass of 0.1 mol / L sodium hydroxide aqueous solution, and 30 parts by mass of methyl ethyl ketone Then, an 8-pass dispersion process was performed with an Ultimateizer 25005 (product name, manufactured by Sugino Machine Co., Ltd.). Thereafter, 300 parts by mass of ion-exchanged water was added, and the entire amount of methyl ethyl ketone and part of the water were distilled off using a rotary evaporator, and the mixture was neutralized with 0.1 mol / L sodium hydroxide to pH 9. It was adjusted. Then, while measuring the volume average particle size of the cyan pigment with a particle size distribution meter, the dispersion is performed until the volume average particle size becomes 100 nm, and the solid content (polymer dispersant and pigment) is reduced to 20 mass by filtration through a 3 μm membrane filter. % Of a pigment dispersion liquid 3 was obtained.

[3.4. Preparation of inkjet ink composition] <Preparation of ink>
(Examples 1 to 15, Comparative Examples 1 to 11)
After the following components were mixed and sufficiently stirred, filtration was performed under reduced pressure with a micro filter (manufactured by Millipore) having a pore size of 5.0 μm to prepare each inkjet ink composition of Examples and Comparative Examples. Tables 1 and 2 show the compositions of the ink-jet ink compositions of Examples and Comparative Examples. The numerical values of the blending amounts of the respective components in Tables 1 and 2 are shown as mass%. In Tables 1 and 2, the amount of the pigment dispersion indicates the amount (% by mass) of the solid pigment.
In each of the ink jet ink compositions of Examples and Comparative Examples, as components other than those shown in Tables 1 and 2, 2% by mass of 1,2-hexanediol (1,2-HD) and 10% of propylene glycol (PG) were used. % By mass, 0.5% by mass of triethanolamine (TEA), 0.02% by mass of EDTA (ethylenediaminetetraacetic acid 2Na salt), Olfine PD501 (Nonionic surfactant manufactured by Nissin Chemical Industries: acetylene glycol-based) And the remaining amount of ion-exchanged water (the remaining amount is such that the total amount of all components of the ink is 100.0%). Tables 1 and 2 show the evaluation results of the respective ink-jet ink compositions. The evaluation method is as follows.

[3.5. Evaluation method〕
Each of the ink-jet ink compositions obtained above is filled in an ink cartridge, and is mounted on an ink-jet recording apparatus (trade name: PX-G930, manufactured by Seiko Epson Corporation) for discharging ink from a recording head by the action of the energy of a piezo element. did. In each of Examples and Comparative Examples, the recording duty of a solid image recorded under the condition that one ink droplet having a mass per droplet of 28 ng ± 10% is applied to a unit area of 1/600 inch × 1/600 inch. It was defined as 100%. The recording conditions were as follows: temperature: 23 ° C. and relative humidity: 55%, unless otherwise specified. The following evaluations were performed for each of the examples and comparative examples, and in these evaluation criteria, A and B were set to acceptable levels, and C and D were set to unacceptable levels.

(Scratch resistance test)
Based on JIS L0849 2013, the test was carried out under the conditions of 200 g load and 100 reciprocations using a gakushin abrasion resistance evaluation device AB-301 of Tester Sangyo. Using the above-mentioned ink jet recording apparatus, a recorded matter in which a 1.0-inch × 0.5-inch solid image having a recording duty of 100% was recorded on a film (trade name: OPP plain roll, 25 μm thick, manufactured by Toyobo) was used. Obtained. Printing was performed at a dot density of 1440 dpi × 1440 dpi while controlling the platen temperature to 55 ° C. A dry cotton wool is pressed onto each solid image of the printed matter 10 minutes after printing and the printed matter one day after printing to evaluate the dry friction property, and the moistened cotton wool is pressed. The wet friction property was evaluated. Thereafter, the stain on the cotton wool, the stain on the non-recording portion, and the degree of peeling of the printed portion were visually checked, and the abrasion resistance was evaluated according to the following evaluation criteria.

(Evaluation criteria)
A: There was almost no stain on the cotton wool and no stain on the non-recording portion, and there was almost no peeling off of the printed portion.
B: There were few stains on the cotton wool and the stain on the non-recording portion, and the printed portion was hardly peeled off.
C: Stain of the cotton wool and non-recording portion were present, and the printed portion was slightly peeled.
D: The cotton wool and the non-recording portion were considerably stained, and the printed portion was often peeled off.

(Intermittent ejection stability test)
A part of the above-described ink jet recording apparatus was modified to obtain a recording apparatus capable of printing on a film. Using this recording apparatus, the discharge stability at the time of intermittent printing under an environment of a temperature of 40 ° C. and a relative humidity of 20% was evaluated. First, it was confirmed that the inkjet ink composition was normally discharged from all the nozzles. Then, after the inkjet ink composition is discharged onto A4 size photographic paper (photo glossy paper manufactured by Seiko Epson Corporation), a pause of 2 minutes is provided under an environment of a temperature of 40% and a relative humidity of 20%, and again, The inkjet ink composition was discharged onto A4 size photographic paper. In the second ejection, the displacement of the dot between the position of the first drop adhering to A4 size photographic paper and the target position was measured with an optical microscope. The intermittent characteristics were evaluated based on the following evaluation criteria based on the obtained dot displacement.

(Evaluation criteria)
A: The dot displacement was 10 μm or less.
B: The displacement of the dots was more than 10 μm and not more than 20 μm.
C: The dot displacement was more than 20 μm and 30 μm or less.
D: The dot misregistration exceeded 30 μm.

(Continuous printing stability test)
A part of the above-described ink jet recording apparatus was modified to obtain a recording apparatus capable of printing on a film. The ink cartridge of the recording apparatus was filled with the ink-jet ink composition obtained above. Then, the inkjet ink composition was discharged onto an A4 size cotton cloth at a resolution of 720 dpi × 720 dpi and dried at 150 ° C. for 1 minute to prepare a recording sample with a cyan solid pattern. In an environment of a temperature of 40 ° C. and a relative humidity of 20%, this operation is repeated up to 8 hours to discharge the ink-jet ink composition, and the time until the droplet of the ink-jet ink composition is not stably discharged from the nozzle is determined. It was measured. Based on the obtained time, the continuous printing stability was evaluated according to the following evaluation criteria.

(Evaluation criteria)
A: Even after 8 hours from the start of ejection, no ejection or ejection disturbance was not observed.
B: Non-discharge or discharge disturbance was observed from 2 hours to less than 8 hours from the start of discharge.
C: Non-discharge or discharge disturbance was observed in 1 hour or more and less than 2 hours from the start of discharge.
D: In less than 1 hour from the start of ejection, non-ejection, ejection disturbance, and the like were observed.

(Clogging recovery test)
Using the above-described ink jet recording apparatus, the ink cartridge of the recording apparatus is filled with the ink jet ink composition obtained above, printed on an A4-size OPP film at a resolution of 720 dpi by 720 dpi and ink jetted by all nozzles. It was confirmed that the ink composition was ejected. Thereafter, the recording apparatus was left for 30 days in an environment at a temperature of 40 ° C. and a relative humidity of 20%. After the standing, the inkjet ink composition was ejected again from all the nozzles, and cleaning was repeatedly performed until printing equivalent to the initial state was possible, and the number of times of cleaning at that time was measured. Based on the number of times of cleaning, clogging recovery was evaluated according to the following evaluation criteria.

(Evaluation criteria)
A: The ink composition was discharged from all the nozzles in one to three cleanings.
B: The ink composition was ejected from all the nozzles in four to six cleanings.
C: The ink composition was ejected from all the nozzles by seven or more cleanings.
D: The ink composition could not be discharged from any of the nozzles after seven or more cleanings.

(20 ° gloss test)
Solid printing (1440 dpi x 1440 dpi) was performed on corona-treated OPP (FOS-AQ manufactured by Futamura Chemical Co., Ltd., 60 μm thick) at a platen temperature of 55 ° C. using the above-described inkjet recording apparatus, and dried at 90 ° C. for 10 minutes to produce a gloss. The 20 ° gloss was measured with a densitometer. The glossiness was measured with a handy glossmeter MULTI GLOS 268 (manufactured by Konica Minolta, Inc.). The 20 ° gloss was evaluated according to the following evaluation criteria.

A: The gloss at 20 ° on the OPP film is 70 or more.
B: The gloss at 20 ° on the OPP film is 55 or more and less than 70.
C: 20 ° gloss on an OPP film is 40 or more and less than 55.
D: 20 ° gloss less than 40 on OPP film.

[3.6. Evaluation results〕
An inkjet jet ink composition containing a specific polyol and a specific polyisocyanate as polymerizable components, respectively, and containing resin particles containing a copolymer having an acid value within a predetermined range, has intermittent ejection stability, continuous printing. Excellent stability, clogging stability, abrasion resistance and gloss were obtained. On the other hand, in the case of the ink-jet ink composition containing no resin particles, it was not possible to at least achieve both abrasion resistance and intermittent ejection stability.

Claims (7)

An inkjet ink composition containing resin particles,
The resin particles include a copolymer containing a polyol and a polyisocyanate as polymerization components, respectively, and have an acid value of 5 to 50 mgKOH / g,
The polyol is a polydiene polyol having two or more hydroxyl groups, a polyolefin polyol having two or more hydroxyl groups, or a hydrocarbon compound having two or more hydroxyl groups and having a cyclic hydrocarbon structure. Yes,
The polyisocyanate is dicyclohexylmethane diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, m-bis (isocyanatopropyl) benzene, m-bis (isocyanatomethyl) benzene, and at least one of these as a polymerization component. An inkjet ink composition which is at least one selected from the group consisting of polyisocyanates.   The inkjet ink composition according to claim 1, wherein the copolymer is a copolymer further containing at least one of a polyamine and a carboxyl group-containing glycol as a polymerization component.   The inkjet ink composition according to claim 1, wherein the copolymer is a copolymer further containing a polyamine and a carboxyl group-containing glycol as a polymerization component.   The inkjet ink composition according to any one of claims 1 to 3, wherein the copolymer contains an isocyanate group-terminated prepolymer or a hydroxyl group-terminated prepolymer.   The inkjet ink composition according to any one of claims 1 to 4, wherein the copolymer is a polyurethane resin or a polyurethane polyurea resin.   An inkjet recording method, comprising an ejection step of ejecting the inkjet ink composition according to any one of claims 1 to 5 onto a recording medium. The inkjet recording method according to claim 6, wherein the recording medium is a recording medium having non-absorptivity or slight absorption.