JP4656504B2 - Treatment liquid for plastic film and ink jet recording method using the same - Google Patents

Description

Background of the Invention

FIELD OF THE INVENTION This invention relates to plastic film processing solutions. Specifically, the present invention is used when printing on a recording medium whose recording surface is a plastic film, and is applied prior to printing of the aqueous ink composition on the recording surface. It relates to a pretreatment liquid. The present invention also relates to an ink jet recording method using such a treatment liquid.

BACKGROUND ART An ink jet recording method is a printing method in which printing is performed by causing droplets of an ink composition to fly and adhere to a recording surface of a recording medium. This method has a feature that a high-resolution and high-quality image can be printed at a high speed with a relatively inexpensive apparatus. As a recording medium, there is an increasing demand for materials such as plastic film in addition to general paper.

  The plastic recorded matter obtained by printing on a plastic film or the like is assumed to be used for posting outdoors where paper cannot be used. For this reason, a higher degree of water resistance and light resistance is required for the plastic recorded matter. In addition, printing of an object touched by a hand such as a label is more suitable for a plastic recorded material than for a paper printed material. Also in this case, the recorded material is required to have durability such as abrasion resistance.

  Conventionally, solvent-based ink, UV curable ink, or two-component curable ink has been used for inkjet recording using a plastic film such as vinyl chloride that has not been surface-treated exclusively for inkjet printing. It was. However, the solvent-based ink has a solvent odor and may contain harmful components in the solvent volatile components. Even in a UV curable ink or a two-component curable ink, the curable monomer to be used may contain harmful components.

  When ink jet recording is performed using a conventional water-based ink on a plastic film not subjected to surface treatment dedicated for ink jet recording, it cannot be said that the adhesion, scratch resistance, and water resistance of the recorded image are sufficient.

  In the case of using a plastic film exclusively for ink jet recording, a method of coagulating and curing a colorant or a dispersion resin as an ink component using water-based ink (Japanese Patent Laid-Open No. 9-286940 (Patent Document 1)) has been proposed. ing.

  Further, for example, Japanese Unexamined Patent Application Publication No. 2003-11486 (Patent Document 2) discloses an ink jet recording method using a pretreatment liquid. However, this recording method is intended to perform recording with high image quality and water resistance on a general recording medium, and is not intended for printing on a plastic film. Further, for example, Japanese Patent Application Laid-Open No. 10-114140 (Patent Document 3) describes using an amide-containing reaction liquid in an ink jet recording method using two liquids. However, in this reaction solution, amide is added to improve printing quality and printing stability, and there is no suggestion that it is intended for printing on plastic films.

  For this reason, an ink jet recording method using an aqueous pigment ink capable of obtaining a plastic recorded matter excellent in water resistance and abrasion resistance is desired.

JP-A-9-286940 JP 2003-11486 A JP-A-10-114140

Summary of the Invention

  The inventors of the present invention now have a treatment liquid having a specific composition containing a specific cyclic amide compound prior to attaching an aqueous ink composition containing a thermoplastic resin that can be formed into a film by heating to the recording surface of the plastic film. It has been found that the surface of the formed plastic recording material can be significantly improved by pre-coating and treating the surface thereof. The present invention is based on such knowledge.

  Therefore, the present invention provides a processing solution for plastic film that can form a plastic recorded matter excellent in abrasion resistance, scratch resistance, and water resistance when used with an aqueous ink composition containing a thermoplastic resin. For that purpose. The present invention also provides an ink jet recording method capable of forming a plastic recording material excellent in abrasion resistance, scratch resistance and water resistance using such a treatment liquid and the aqueous ink composition. Is also the purpose.

［式中、
Ｒは、直鎖状もしくは分岐鎖状の、Ｃ２〜１２の飽和炭化水素鎖を表し、かつ
Ｘは、水素原子、または、直鎖状もしくは分岐鎖状のＣ１〜６のアルキル基を表す］。 The treatment liquid for an ink jet recording medium in which the recording surface is a plastic film according to the present invention comprises at least a cyclic amide compound of the following formula (I) and a main solvent:

[Where:
R represents a linear or branched C2-12 saturated hydrocarbon chain, and X represents a hydrogen atom or a linear or branched C1-6 alkyl group].

According to a preferred embodiment of the present invention, the main solvent of the treatment liquid is water.
According to a preferred embodiment of the present invention, the treatment liquid further comprises a surfactant and / or a low surface tension organic solvent.

  The inkjet recording method according to the present invention is an inkjet recording method in which a treatment liquid is applied to a recording medium whose recording surface is a plastic film, and then droplets of the ink composition are ejected and adhered to the recording surface for printing. The treatment liquid is a treatment liquid for plastic film according to the present invention, and the ink composition is an aqueous pigment ink composition comprising at least a pigment, a thermoplastic resin, and water. It is characterized by.

Detailed description of the invention

Treatment Liquid The treatment liquid according to the present invention is for an ink jet recording medium whose recording surface is a plastic film as described above, and comprises at least a cyclic amide compound of the following formula (I) and a main solvent. Here, the main solvent is preferably water as described later. The treatment liquid according to the present invention preferably further comprises a surfactant and / or a low surface tension organic solvent, more preferably further comprises a surfactant, or the surfactant and the low surface tension. It further comprises a tension organic solvent. The treatment liquid according to the present invention is preferably applied to a recording medium by an ink jet recording method.

  The treatment liquid according to the present invention is used for printing on a recording medium whose recording surface is a plastic film. Here, the recording medium whose recording surface is a plastic film includes, in addition to the recording medium itself being a plastic film, a plastic recording material on a conventional recording medium substrate such as paper, Also included are those obtained by bonding a plastic film thereon. Here, the plastic is not particularly limited as long as it can be dissolved or wetted by the cyclic amide compound of the formula (I). For example, vinyl chloride, polyethylene terephthalate (PET), polycarbonate , Polystyrene, polyurethane and the like. In the present invention, the plastic is preferably vinyl chloride. Further, the treatment liquid according to the present invention can be used for printing on either a plastic film that has not been subjected to a surface treatment for inkjet printing or a plastic film that has been subjected to a surface treatment for inkjet printing.

  By using the treatment liquid of the present invention together with an aqueous ink composition containing a thermoplastic resin, it is possible to form a plastic recorded matter excellent in abrasion resistance, scratch resistance and water resistance. At this time, the ink composition is an aqueous pigment ink composition comprising at least a pigment, a thermoplastic resin, and water. Therefore, according to the present invention, since a pigment-based aqueous ink composition can be used, a recorded matter having excellent light resistance can be formed on a plastic film.

The reason why the desired effect is achieved by the present invention is considered as follows. However, the following is assumed and the present invention is not limitedly interpreted by this.
When the treatment liquid according to the present invention is applied to a plastic film, it uniformly spreads on the surface, and when the water evaporates in this state, the cyclic amide compound can remain on the plastic film surface in a uniform and high concentration. As a result, it is considered that the cyclic amide compound can dissolve or wet the extremely shallow portion from the surface of the plastic film. When a water-based ink containing a resin that can be formed into a film by heating is attached thereto, and then the resin contained therein is cured to form a film, it is contained in the aqueous ink at the interface between the cured film and the plastic. It is thought that a layer in which resin and plastic are mixed is formed. Since this mixed layer is integrated with each of the plastic and the film formed by curing the resin contained in the ink, the adhesion between the ink layer and the plastic surface can be dramatically improved. Conceivable. By increasing the adhesion, the external force such as rubbing and the peeling due to the ingress of water into the interface are almost eliminated, and a plastic recorded matter excellent in abrasion resistance, scratch resistance and water resistance can be formed. . For this reason, it becomes possible to produce a tough printed matter that takes advantage of the durability of the plastic film itself.

  In the treatment liquid according to the present invention, since the cyclic amide compound, which is a component capable of dissolving the plastic, is preferably diluted with water, the liquid contact member constituting the printer is hardly destroyed or damaged. Further, since the preferred treatment liquid according to the present invention is an aqueous solution, the treatment liquid itself and the generated vapor are also excellent in safety.

Cyclic amide compound The treatment liquid according to the present invention comprises the cyclic amide compound of formula (I) as an essential component.
In the formula (I), as described above, R represents a linear or branched C2-12 saturated hydrocarbon chain, and X represents a hydrogen atom or a linear or branched chain. Represents a C1-6 alkyl group.

  Here, R preferably represents a C2-8 saturated hydrocarbon chain, more preferably C2-5, still more preferably C2-4. Here, for example, “C2-12” in the case of “C2-12 saturated hydrocarbon chain” means that the saturated hydrocarbon chain has 2 to 12 carbon atoms.

The saturated hydrocarbon chain linear C2~12, - _(CH 2) (in m here represents an integer of 2 to 12) chain represented by m- means that the. The branched saturated hydrocarbon chain C2~12, - (CH 2) a chain represented by _n-, the hydrogen on the carbon in the carbon number total such that p number 1 or more It means a chain having a side chain substituted with an alkyl group (where n + p (p is the total number of carbons in all side chains) represents an integer of 2 to 12). Examples of such an alkyl substituent include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, an s-butyl group, and a t-butyl group. Moreover, the saturated hydrocarbon chain on a straight chain or branched chain may be further substituted with a hydroxyl group, a hydroxymethylene group or the like, if necessary.
Specific examples of the linear or branched C2-12 saturated hydrocarbon chain include ethylene and propylene.

  In addition, here, “C1-6” in “C1-6 alkyl group” in “linear or branched C1-6 alkyl group” means that the alkyl group has 1 to 6 carbon atoms. It means that there is. Examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, s-butyl group, t-butyl group, pentyl group, hexyl group and the like.

  Preferably, the “C1-6 alkyl group” is a C1-4 alkyl group, more preferably a C1-3 alkyl group, still more preferably a methyl group or an ethyl group, and particularly preferably a methyl group.

  According to a preferred embodiment of the present invention, in formula (I), R represents a linear or branched C2-5 saturated hydrocarbon group, and X represents a hydrogen atom or a methyl group.

  Specific examples of the cyclic amide compound include 2-pyrrolidone, N-methyl-2-pyrrolidone, 5-methyl-2-pyrrolidone, δ-valerolactam, ε-caprolactam, preferably 2-pyrrolidone, N And those selected from the group consisting of -methyl-2-pyrrolidone and ε-caprolactam.

  According to a preferred embodiment of the present invention, at least two cyclic amide compounds of the formula (I) are used. By using two or more kinds of cyclic amide compounds, it is possible to prevent the cyclic amide compounds from being separated or crystallized in the process of evaporating the solvent of the treatment liquid. Also, by using two or more types, the solubility of the cyclic amide compound in the solvent of the treatment solution can be increased, and the cyclic amide compound becomes uneven on the plastic surface, preventing the plastic dissolving ability from changing partially. it can.

  Preferable specific examples when two or more kinds of cyclic amide compounds are used include a combination of 2-pyrrolidone and ε-caprolactam, a combination of N-methyl-2-pyrrolidone and ε-caprolactam, or 2-pyrrolidone and N-methyl. Examples include a combination of 2-pyrrolidone, a combination of 2-pyrrolidone, N-methyl-2-pyrrolidone, and ε-caprolactam.

  The cyclic amide compound used in the present invention may be synthesized as necessary, but a commercially available product may be used.

  The content of the cyclic amide compound in the treatment liquid of the present invention can be set to a concentration and surface tension that can be uniformly applied to the recording medium, and hardly destroys or damages the liquid contact member constituting the printer. There is no particular limitation as long as it is of the order. The content of the cyclic amide compound is, for example, 0.1 to 50.0% by weight, preferably 5.0 to 30.0% by weight with respect to the total amount of the treatment liquid. The content at this time means the total amount when two or more cyclic amide compounds are used.

While the aqueous surfactant solution is repelled by the usual plastic, the treatment liquid according to the present invention, it is possible to add a surfactant and / or low surface tension organic solvent, uniformly applying a cyclic amide compound to a plastic surface be able to. It is considered that by evaporating water from the uniformly applied treatment solution, the cyclic amide compound can be fixed on the plastic surface without excess and deficiency, and only the plastic surface in a desired region can be dissolved.

  In the present invention, as the surfactant, any of anionic, cationic, amphoteric, and / or nonionic can be used.

  Examples of the anionic surfactant include alkyl sulfocarboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, N-acyl amino acids and salts thereof, N-acyl methyl taurates, alkyl sulfates. Polyoxyalkyl ether sulfate, alkyl sulfate polyoxyethylene alkyl ether phosphate, rosin acid soap, castor oil sulfate ester, lauryl alcohol sulfate ester, alkylphenol type phosphate ester, alkyl type phosphate ester, alkylaryl sulfonate, Examples thereof include diethyl sulfosuccinate, diethylhexyl sulfosuccinate, dioctyl sulfosuccinate, 2-vinylpyridine derivatives, poly-4-vinylpyridine derivatives, and the like.

  Examples of amphoteric surfactants include lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine and other imidazolines. Derivatives and the like can be mentioned.

（ここで、Ｒ^１１、Ｒ^１２、Ｒ^１３、およびＲ^１４はそれぞれ独立して炭素数１〜６のアルキル基を表し、ｎおよびｍはそれらの和が０〜３０となる整数である）で表されるアセチレングリコール系界面活性剤、例えば、２，４，７，９−テトラメチル−５−デシン−４，７−ジオール（例えば、Air Products and Chemicals. Inc.社製のサーフィノール１０４）、３，６−ジメチル−４−オクチン−３，６−ジオール（例えば、Air Products and Chemicals. Inc.社製のサーフィノール８２）、これらアセチレングリコール類の誘導体（例えば、Air Products and Chemicals. Inc.社製のサーフィノール４６５、４８５など）などがある。 Examples of the nonionic surfactant include polyoxyethylene nonyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl aryl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene alkyl ether, Ethers such as polyoxyalkylene alkyl ether, polyoxyethylene oleate, polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, poly Esters such as oxyethylene monooleate and polyoxyethylene stearate, or the following formula (i):

(Here, R ¹¹ , R ¹² , R ¹³ , and R ¹⁴ each independently represent an alkyl group having 1 to 6 carbon atoms, and n and m are integers whose sum is 0 to 30). Acetylene glycol-based surfactants such as 2,4,7,9-tetramethyl-5-decyne-4,7-diol (eg, Surfynol 104 from Air Products and Chemicals. Inc.), 3,6-dimethyl-4-octyne-3,6-diol (for example, Surfynol 82 manufactured by Air Products and Chemicals. Inc.) and derivatives of these acetylene glycols (for example, Air Products and Chemicals. Inc.) Manufactured by Surfinol 465, 485, etc.).

  Among these, nonionic surfactants having good foaming or nozzle ejection reliability are preferable, and acetylene glycol surfactants are more preferable.

The content of the surfactant in the treatment liquid of the present invention is not particularly limited as long as the cyclic amide compound can be uniformly applied to the plastic surface, and the type of surfactant used and the type of cyclic amide compound are not limited. And it can select suitably according to the quantity. The content of the surfactant is, for example, 0.01 to 5.0% by weight, preferably 0.1 to 2.0% by weight, based on the total amount of the treatment liquid.
Low surface tension organic solvent In order to uniformly coat the cyclic amide compound on the plastic surface, the treatment liquid of the present invention comprises a low surface tension organic solvent instead of or in addition to the surfactant. be able to.

  Examples of the low surface tension organic solvent include monohydric alcohols and polyhydric alcohol derivatives.

  As the monohydric alcohol, a monohydric alcohol having 1 to 4 carbon atoms such as methanol, ethanol, n-propanol, i-propanol, or n-butanol can be used.

In particular, as the polyhydric alcohol derivative, a complete or partial ether of a divalent to pentavalent alcohol having 2 to 6 carbon atoms and a lower alcohol having 1 to 4 carbon atoms can be used. Here, the polyhydric alcohol derivative is an alcohol derivative in which at least one hydroxyl group is etherified, and does not mean a polyhydric alcohol itself that does not contain an etherified hydroxyl group. The preferred polyhydric alcohol lower alkyl ether as the ether is represented by the general formula (ii):
R ²¹ _O-[CH 2 -CH ^(R 23) -O] ^{t-R 22} (ii)
[Wherein R ²¹ and R ²² each independently represent a hydrogen atom or an alkyl group having 3 to 6 carbon atoms (preferably a butyl group), and R ²³ represents a hydrogen atom or a lower alkyl having 1 to 4 carbon atoms. A group, preferably a hydrogen atom, a methyl group or an ethyl group, and t is an integer of 1 to 8, preferably 1 to 4, provided that at least one of R ²¹ and R ²² is an alkyl having 3 to 6 carbon atoms. It is a group (preferably a butyl group)].

  Specific examples of these polyhydric alcohol lower alkyl ethers include, for example, mono, di or triethylene glycol-mono or di-alkyl ether, mono, di or tripropylene glycol-mono or di-alkyl ether, and preferably May include triethylene glycol monobutyl ether, diethylene glycol monobutyl ether, diethylene glycol monopropyl ether, diethylene glycol monopentyl ether, or propylene glycol monobutyl ether.

  According to a preferred embodiment of the present invention, the low surface tension organic solvent is diethylene glycol monobutyl ether or triethylene glycol monobutyl ether.

  The content of the low surface tension organic solvent in the treatment liquid of the present invention is not particularly limited as long as the cyclic amide compound can be uniformly applied to the plastic surface, and the type of cyclic amide compound and surfactant to be used. And can be selected according to the amount. The content of the low surface tension organic solvent is, for example, 0 to 25.0% by weight, preferably 2.0 to 15.0% by weight with respect to the total amount of the treatment liquid.

  Although various physical properties of the treatment liquid according to the present invention can be appropriately controlled, according to a preferred embodiment of the present invention, the viscosity of the treatment liquid is preferably 25 mPa · sec or less, more preferably 10 mPa · sec or less (25 ° C.). It is. When the viscosity is within this range, the ink composition can be stably discharged from the ink discharge head. The treatment liquid according to the present invention can be appropriately controlled, and the surface tension is preferably in the range of 20.0 to 40.0 mN / m (25 ° C.), more preferably 25.0 to 35.0 mN / m. m range.

Main solvent The treatment liquid according to the present invention comprises a main solvent. In order to apply the water-soluble component containing the cyclic amide compound thinly and uniformly on the plastic surface, in the present invention, the cyclic amide compound is diluted with a main solvent and applied. As such a main solvent, water or a water-soluble organic solvent can be used. In the present invention, water is preferable from the viewpoint of safety and the like.
Therefore, in the treatment liquid in the present invention, preferably, the main solvent is water. As water used here, pure water such as ion exchange water, ultrafiltration water, reverse osmosis water, distilled water, or ultrapure water is used for the purpose of reducing ionic impurities as much as possible. it can. In addition, it is preferable to use water sterilized by ultraviolet irradiation or addition of hydrogen peroxide because generation of mold and bacteria can be prevented when the treatment liquid is stored for a long period of time.

Other components The treatment liquid of the present invention can achieve a desired effect by including the above-mentioned components, but if necessary, an antiseptic / antifungal agent, a pH adjuster, a dissolution aid, An antioxidant, a nozzle clogging preventing agent, and the like can be further included.

  Examples of the pH adjuster include potassium dihydrogen phosphate and disodium hydrogen phosphate. Examples of preservatives and fungicides include sodium benzoate, sodium pentachlorophenol, sodium 2-pyridinethiol-1-oxide, sodium sorbate, sodium dehydroacetate, 1,2-dibenzisothiazoline-3-one (Proxel CRL, Proxel BDN, Proxel GXL, Proxel XL-2, Proxel TN from ICI) and the like. Furthermore, examples of the dissolution aid or antioxidant include amines such as diethanolamine, triethanolamine, propanolamine, morpholine and their modified products, inorganic salts such as potassium hydroxide, sodium hydroxide, and lithium hydroxide. , Ammonium hydroxide, quaternary ammonium hydroxide (such as tetramethylammonium), carbonates such as potassium carbonate, sodium carbonate, lithium carbonate, and other phosphates, or N-methyl-2-pyrrolidone, urea, thiourea, tetra Examples include L-ascorbic acid and salts thereof, such as ureas such as methylurea, allophanates such as allophanate and methylallohanate, and biurets such as biuret, dimethylbiuret and tetramethylbiuret. Furthermore, urea, thiourea, ethylene urea or the like can be added for the purpose of preventing nozzle drying.

Production of treatment liquid The treatment liquid of the present invention is prepared by appropriately mixing and dissolving (or dispersing) each of the above-mentioned blending components in an arbitrary order, and then removing impurities by filtration as necessary. can do.

In the treatment liquid according to the present invention, the aqueous ink composition to be attached after the treatment liquid and the plastic surface can exhibit high adhesion; the cyclic amide compound can be uniformly applied to the plastic surface; and can be ejected by an ink jet recording head. Viscosity and surface tension; the processing liquid does not aggregate or solidify in the storage container or at the nozzle of the inkjet head; and further, the liquid contact member of the inkjet printer is not dissolved or destroyed, The compounding quantity of each said component can be set suitably. Typical compositions of such treatment liquids include, for example, the following:
Cyclic amide compound 0.1 to 50.0% by weight;
Surfactant 0.01-5.0% by weight;
Low surface tension organic solvent 0-25.0% by weight; and water remaining.

  Therefore, according to one preferable aspect of the present invention, in the treatment liquid, the content of the cyclic amide compound is 0.1 to 50.0% by weight, and the content of the surfactant is 0.01 to 5%. 0.0% by weight.

Recording Method The inkjet recording method according to the present invention, as described above, applies a treatment liquid onto a recording medium whose recording surface is a plastic film, and then ejects ink composition droplets to adhere to the recording surface. Printing.

  In the step of applying the treatment liquid, the treatment liquid according to the present invention is applied to the recording surface of the recording medium. In this step, it is desirable to apply the treatment liquid in advance to at least a portion (printing portion) where the water-based pigment ink is applied in the next step in which ink jet recording is performed. The coating amount can be appropriately adjusted according to the state of the plastic film that is the recording medium, the type of material, the amount of ink to be applied, and the like.

  In the present invention, the coating method of the treatment liquid is not particularly limited, and for example, brush coating, air knife coater, roll coater, bar coater, blade coater, slide hopper coater, gravure coater, flexographic gravure coater, curtain coater, ext A coating method using a known coating device such as a rouge coater, a floating knife coater, a comma coater, a die coater, a gate roll coater, or a size press device, or non-spraying using a spray, an inkjet head, a jet nozzle, etc. The method of apply | coating by a contact system etc. are mentioned.

  In the present invention, the method for applying the treatment liquid is preferably an ink jet recording method in which droplets are ejected and adhered to the recording surface of the recording medium. By adopting the ink jet recording method, the application position and the application amount of the treatment liquid can be appropriately controlled. By controlling the application position, the processing liquid can be applied only to the part to be printed, so the amount of processing liquid used can be saved, and when the edge of the plastic recording medium is printed, the processing liquid protrudes from the plastic recording medium. Can be prevented. In addition, when a large amount of solvent is applied to a plastic recording medium, the entire plastic is dissolved or softened. However, by controlling the coating amount, only a very shallow portion from the surface of the plastic recording medium can be selectively dissolved. it can.

  According to a preferred aspect of the present invention, the ink jet recording method according to the present invention further includes a drying step of evaporating the water of the applied treatment liquid and evaporating a part of the cyclic amide compound before attaching the ink composition. It becomes. Here, evaporating a part of the cyclic amide compound of the treatment liquid means that the cyclic amide compound is not completely evaporated from the treatment liquid application surface when the ink composition is adhered to the treatment liquid application surface. Further, it means that the cyclic amide compound in the treatment liquid on the coated surface is evaporated so that the dissolved state of the plastic surface is maintained. The amount of the cyclic amide compound necessary for achieving such a dissolved state (or the amount of the cyclic amide compound to be evaporated) is determined in consideration of the degree of adhesion between the film formed by the ink composition and the plastic surface. It can be changed as appropriate by adjusting the drying conditions.

  The water after the treatment liquid is applied can be dried according to a conventional method using a conventional heating and drying means, for example, a known heating device such as an infrared heating device or a hot air heating device. In the present invention, the drying process in the drying step can be preferably performed by heating with a heater or drying with hot air. In the case of heater heating or hot air drying, drying can be performed at 25 to 90 ° C (preferably 40 to 70 ° C) for 1 to 60 minutes.

  Next, in the ink jet recording method of the present invention, after the treatment liquid is applied, the ink composition is adhered to the application surface. At this time, it is desirable that the method of attaching the ink is an ink jet recording method. Here, the ink composition is an aqueous pigment ink composition comprising at least a pigment, a thermoplastic resin, and water, which will be described later.

  According to a preferred aspect of the present invention, the ink jet recording method of the present invention further comprises a heating step of heating the ink composition adhered to the recording surface to form a resin film. Here, the heating means can be performed according to a conventional method using a conventional heating means, for example, a known heating device such as an infrared heating device or a hot air heating device. In the present invention, the heat treatment in the heating step can be preferably carried out by heater heating or hot air drying. Further, the heating condition may be any condition as long as the resin contained in the ink composition can be cured by heating to form a resin film, taking into account the type of resin particles and the like. It can be set appropriately. For example, in the case of heater heating or warm air drying, heating can be performed at 25 to 90 ° C. (preferably 40 to 70 ° C.) for 1 minute to 1 day (preferably 2 minutes to 16 hours). .

Aqueous Pigment Ink Composition The aqueous pigment ink composition that can be used in the present invention comprises at least a pigment, a thermoplastic resin, and water.

Pigment In the present invention, the aqueous pigment ink composition may contain any pigment conventionally used in an aqueous ink jet recording ink composition. As the pigment, for example, an organic pigment or an inorganic pigment conventionally used in an ink composition for inkjet recording can be used. The pigment is a resin-dispersed pigment dispersed with a dispersant such as a water-soluble resin or a surfactant, or a surface-treated pigment that has a hydrophilic group introduced into the pigment surface and can be dispersed or dissolved in an aqueous medium without the use of a dispersant. Can be added to the ink composition. In addition, when dispersing a pigment with a resin dispersing agent, you may use the thermoplastic resin mentioned later as a dispersing agent. Two or more pigments may be used in combination.

  As the inorganic pigment, titanium oxide and iron oxide, or carbon black produced by a known method such as a contact method, a furnace method, or a thermal method can be used.

  Examples of organic pigments include azo pigments (for example, azo lakes, insoluble azo pigments, condensed azo pigments, or chelate azo pigments), polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, verinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, A thioindigo pigment, an isoindolinone pigment, or a quinophthalone pigment), a dye chelate (for example, a basic dye chelate or an acid dye chelate), a nitro pigment, a nitroso pigment, or aniline black can be used. Of these pigments, it is preferable to use a pigment having good affinity with water.

  The particle diameter of the pigment is not particularly limited, but the average particle diameter is preferably 25 μm or less, more preferably 1 μm or less. By using a pigment having an average particle diameter of 25 μm or less, the occurrence of clogging can be suppressed, and further sufficient ejection stability can be realized.

  The content of the pigment is preferably 0.5 to 25% by weight, more preferably 2 to 15% by weight, based on the entire ink composition.

Thermoplastic resin In the present invention, the aqueous pigment ink composition comprises a thermoplastic resin. As the thermoplastic resin, a resin that is soluble in an aqueous ink medium or an insoluble resin can be used. As the resin soluble in the water-based ink medium, a resin dispersant used for dispersing the above-mentioned pigment can be preferably used. In addition, it is preferable that the resin insoluble in the aqueous ink medium is added to the ink composition in the form of a resin emulsion. Here, the resin emulsion is composed of water as a continuous phase and a resin component (thermoplastic resin component) as a dispersed phase.

  According to a preferred embodiment of the present invention, the thermoplastic resin is preferably a polymer having both a hydrophilic portion and a hydrophobic portion. When a resin emulsion is used as the thermoplastic resin, the particle size is not particularly limited as long as the emulsion is formed, but is preferably about 150 nm or less, more preferably about 5 to 100 nm.

  As the thermoplastic resin, a resin component similar to a dispersant resin or a resin emulsion conventionally used in ink compositions for ink jet recording can be used. Specific examples of the thermoplastic resin include acrylic polymers such as polyacrylic acid esters or copolymers thereof, polymethacrylic acid esters or copolymers thereof, polyacrylonitrile or copolymers thereof, polycyanoacrylates, poly Acrylamide, polyacrylic acid, or polymethacrylic acid; polyolefin polymers such as polyethylene, polypropylene, polybutene, polyisobutylene, polystyrene or copolymers thereof, petroleum resins, coumarone-indene resins, or terpene resins; vinyl acetate Vinyl alcohol polymers such as polyvinyl acetate or copolymers thereof, polyvinyl alcohol, polyvinyl acetal, or polyvinyl ether; halogen-containing polymers such as polyvinyl chloride or copolymers thereof. Polymers, polyvinylidene chloride, fluororesins, or fluororubbers; nitrogen-containing vinyl polymers such as polyvinyl carbazole, polyvinyl pyrrolidone or copolymers thereof, polyvinyl pyridine, or polyvinyl imidazoles; diene polymers such as polybutadiene or the like A copolymer, polychloroprene, or polyisoprene (butyl rubber); or other ring-opening polymerization resin, condensation polymerization resin, natural polymer resin, or the like can be used.

  When the thermoplastic resin is obtained in the form of an emulsion, it can be prepared by mixing the resin particles with water, optionally with a surfactant. For example, an emulsion of an acrylic resin or a styrene-acrylic acid copolymer resin is composed of a (meth) acrylic ester resin or a styrene- (meth) acrylic ester resin, and optionally a (meth) acrylic resin, It can be obtained by mixing the active agent with water. The mixing ratio of the resin component and the surfactant is usually preferably about 50: 1 to 5: 1. When the amount of the surfactant used is less than the above range, it is difficult to form an emulsion, and when the amount exceeds the above range, the water resistance of the ink tends to decrease or the adhesion tends to deteriorate. Absent.

  The surfactant used here is not particularly limited, but preferred examples include anionic surfactants (for example, sodium dodecyl benzan sulfonate, sodium laurylate, ammonium salt of polyoxyethylene alkyl ether sulfate, etc.), nonions Surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl amines, polyoxyethylene alkyl amides, etc. These can be used as a mixture of two or more.

  An emulsion of a thermoplastic resin can also be obtained by emulsion polymerization of the above resin component monomers in water in the presence of a polymerization catalyst and an emulsifier. A polymerization initiator, an emulsifier, and a molecular weight modifier used in the emulsion polymerization can be used according to a conventional method.

  As the polymerization initiator, those used for normal radical polymerization are used, for example, potassium persulfate, ammonium persulfate, hydrogen peroxide, azobisisobutyronitrile, benzoyl peroxide, dibutyl peroxide, Examples include peracetic acid, cumene hydroperoxide, t-butyl hydroxy peroxide, paramentane hydroxy peroxide, and the like. When the polymerization reaction is performed in water, a water-soluble polymerization initiator is preferable. Examples of the emulsifier include sodium lauryl sulfate, those generally used as an anionic surfactant, nonionic surfactant or amphoteric surfactant, and mixtures thereof. These can be used in combination of two or more.

  The ratio of the resin and water as the dispersed phase component is preferably 60 to 400 parts by weight, more preferably 100 to 200 parts by weight of water with respect to 100 parts by weight of the resin.

  When a resin emulsion is used as the thermoplastic resin, a known resin emulsion can be used. For example, the resin emulsions described in JP-B-62-1426, JP-A-3-56573, JP-A-3-79678, JP-A-3-160068, or JP-A-4-18462 can be used as they are. . Commercially available resin emulsions can also be used. For example, Microgel E-1002, E-5002 (styrene-acrylic resin emulsion; manufactured by Nippon Paint Co., Ltd.), Boncoat 4001 (acrylic resin emulsion; Dainippon) Ink Chemical Co., Ltd.), Boncoat 5454 (styrene-acrylic resin emulsion; Dainippon Ink and Chemicals Co., Ltd.), SAE1014 (styrene-acrylic resin emulsion; manufactured by Nippon Zeon Co., Ltd.), or Cybinol SK-200 ( Acrylic resin emulsion; manufactured by Seiden Chemical Co., Ltd.).

  In the present invention, the thermoplastic resin may be mixed with other components in the aqueous ink composition as fine particle powder. However, after the resin fine particles are dispersed in an aqueous medium to form a resin emulsion, the aqueous ink composition is used. It is preferable to mix with other components of the product.

  The thermoplastic resin is preferably contained in the range of 0.1 to 30% by weight in terms of solid content, more preferably in the range of 0.3 to 15% by weight, based on the total amount of the aqueous pigment ink composition. preferable.

Water and other component water-based pigment ink compositions comprise water. Here, water can be selected according to the description in the “main solvent” column of the treatment liquid. In addition, the aqueous pigment ink composition includes other known components such as a penetrating agent and a moisturizing agent, columns such as “surfactant”, “low surface tension organic solvent”, and “other components” of the treatment liquid described above. Can be appropriately selected and used in accordance with the description.

  The water-based pigment ink composition of the present invention is necessary after each of the above-mentioned blending components individually or in the form of a pigment dispersion or a resin emulsion and appropriately mixed and dissolved (or dispersed) in any order. Accordingly, it can be prepared by removing impurities by filtration.

  According to another aspect of the present invention, there is provided a recorded matter printed by the ink jet recording method according to the present invention.

  Hereinafter, the present invention will be described in detail with reference to the following examples, but the present invention is not limited thereto.

Preparation of Treatment Solution A treatment solution according to the present invention was prepared according to the following composition.
Treatment liquid 1:
2-pyrrolidone 10.0% by weight
ε-Caprolactam 15.0 wt%
Diethylene glycol monobutyl ether 3.0% by weight
Surfinol 465 1.0 wt%
Pure water remaining

Treatment liquid 2:
N-methyl-2-pyrrolidone 10.0 wt%
ε-Caprolactam 15.0 wt%
Diethylene glycol monobutyl ether 3.0% by weight
Surfinol 465 1.0 wt%
Pure water remaining

Preparation of water-based pigment ink composition Water-based pigment ink compositions were prepared according to the following compositions.
Black ink:
Carbon black MA7 (Mitsubishi Kasei Co., Ltd.) 5.0 wt%
Styrene-acrylic acid copolymer (thermoplastic resin) 2.5 wt% (solid content)
Glycerin 3.0% by weight
Diethylene glycol 4.0 wt%
Diethylene glycol monobutyl ether 3.0% by weight
2-pyrrolidone 3.0 wt%
Surfinol 465 1.0 wt%
Pure water remaining

Cyan ink:
C. I. Pigment Blue 15: 3 2.0 wt%
Styrene-acrylic acid copolymer (thermoplastic resin) 1.0 wt% (solid content)
Glycerin 3.0% by weight
Diethylene glycol 6.0% by weight
Diethylene glycol monobutyl ether 3.0% by weight
2-pyrrolidone 3.0 wt%
Surfinol 465 1.0 wt%
Pure water remaining

Magenta ink:
C. I. Pigment Red 122 3.0 wt%
Styrene-acrylic acid copolymer (thermoplastic resin) 1.5% by weight (solid content)
Glycerin 3.0% by weight
Diethylene glycol 5.0% by weight
Diethylene glycol monobutyl ether 3.0% by weight
2-pyrrolidone 3.0 wt%
Surfinol 465 1.0 wt%
Pure water remaining

Yellow ink:
C. I. Pigment Yellow 74 2.0 wt%
Styrene-acrylic acid copolymer (thermoplastic resin) 1.0 wt% (solid content)
Glycerin 3.0% by weight
Diethylene glycol 6.0% by weight
Diethylene glycol monobutyl ether 3.0% by weight
2-pyrrolidone 3.0 wt%
Surfinol 465 1.0 wt%
Pure water remaining

Evaluation test
Creating print samples (Examples 1-5):
Treatment liquid 1 or treatment liquid 2 is applied to a soft vinyl chloride film (Scotch film; Sumitomo 3M Co., Ltd.) that has not been subjected to surface treatment exclusively for inkjet printing using an inkjet printer (TM-J8000; manufactured by Seiko Epson Corporation). It was applied at 50% duty. Thereafter, the ink is dried for 5 minutes in a constant temperature bath at 60 ° C. and a relative humidity of 20% until the water evaporates, and immediately filled with black ink, cyan ink, magenta ink, or yellow ink (TM-J8000; Seiko Epson Corporation). 100% duty pattern was printed using
The printed sample was dried in a thermostatic bath at 60 ° C. and a relative humidity of 20% for 1 hour and further at room temperature for 1 day, and then subjected to the following evaluation test.

Preparation of print samples (Examples 6 to 9 (comparative examples)):
Using an ink jet printer (TM-J8000; manufactured by Seiko Epson Corporation) filled with black ink, cyan ink, magenta ink, or yellow ink, 100% of the same soft vinyl chloride film (no treatment liquid applied) as in Example 1 A duty pattern was printed. This was dried in a thermostatic bath at 60 ° C. and a relative humidity of 20% for 1 hour and further at room temperature for 1 day, and then subjected to the following evaluation test.

Sample evaluation
Evaluation 1: Scratch resistance and scratch resistance A pencil with a printed film was removed using a 750 g load pencil scratch tester (manufactured by Imoto Seisakusho Co., Ltd.) specified in JIS K-5600-5-4 for pencils of each hardness. The presence or absence of scratches (cohesive failure) was examined. The results were evaluated according to the following criteria.
A: The HB hardness pencil is not damaged and the substrate does not appear.
B: Although the foundation | substrate appears by being damaged with a HB hardness pencil, a foundation | substrate does not appear with a B hardness pencil.
C: The groundwork appears after being damaged by a B hardness pencil.

Evaluation 2: An adhesive pressure-sensitive adhesive tape (Cello Tape No. 252; manufactured by Sekisui Chemical Co., Ltd.) was applied to the printing part of the print sample and rubbed with a finger two to three times, and then the pressure-sensitive adhesive tape was peeled off. The state of the printed part of the part was visually observed. The results were evaluated according to the following criteria.
A: There is no peeling of the ink (colorant) from the vinyl chloride film.
B: Part of the ink (colorant) peels from the vinyl chloride film.
C: The ink (colorant) is completely peeled from the vinyl chloride film.

Evaluation 3: One drop of tap water was allowed to adhere to the printing portion of the water- resistant print sample and left for 1 minute, and then the water drop was wiped off with gauze. The state of the printed part and gauze after wiping off was visually observed. The results were evaluated according to the following criteria.
A: There is no peeling of the ink (colorant) from the vinyl chloride film, and the gauze is not colored.
B: A part of the ink (colorant) is peeled off from the vinyl chloride film, and the gauze is colored.
C: The ink (colorant) is completely peeled from the vinyl chloride film, and the gauze is colored.

  The results were as shown in Table 1 below.

Claims (8)

A first ink composition comprising at least two cyclic amide compounds of the following formula (I) and water or a water-soluble organic solvent, wherein the components in addition to the cyclic amide compound are converted in terms of% by weight. A first ink composition having the largest amount of water or the water-soluble organic solvent;
A second ink composition comprising a pigment, a thermoplastic resin, and water;
An ink set consisting of

[Wherein, R represents a linear or branched C2-12 saturated hydrocarbon chain, and X represents a hydrogen atom or a linear or branched C1-6 alkyl group. Represents]. The ink set according to claim 1, wherein, in formula (I), R represents a linear or branched C2-5 saturated hydrocarbon group, and X represents a hydrogen atom or a methyl group . The ink set according to claim 1 , wherein the cyclic amide compound is selected from the group consisting of 2-pyrrolidone, N-methyl-2-pyrrolidone, and ε-caprolactam .   A recording method using the ink set according to any one of claims 1 to 3,
  After the first ink composition is applied to the recording surface of the recording medium to form a first ink composition film, droplets of the second ink composition are ejected, and the first ink composition is ejected. An ink jet recording method for performing recording by adhering to a composition film. The inkjet recording method according to claim 4, wherein the recording surface is a plastic film. Before depositing the second ink composition,
The applied water or water-soluble organic solvent in the first ink composition Ru evaporated jet recording method according to claim 4 or 5. The inkjet according to any one of claims 4 to 6 , further comprising a heating step of heating the second ink composition attached to the first ink composition film to form a resin film. Recording method. A recorded matter recorded by the ink jet recording method according to claim 4 .