JP2009113494A - Inkjet recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording method capable of improving ink aggregation and color mixture (bleeding) when performing printing of a high duty of at least 50% in particular with aqueous ink and improving quick drying property for a recording medium of which the surface to be recorded is a plastic film. <P>SOLUTION: The inkjet recording method comprises a step of ejecting droplets of aqueous ink composition to the recording medium of which the recording surface is a plastic film and attaching the droplets to the recording surface to perform the printing, wherein the aqueous ink composition including at least colorant, silicone-type surface active agent of 0.1 wt.% to 1.5 wt.%, acetylene glycol-type surface active agent, pyrrolidone derivative, thermoplastic resin and water is used, and the aqueous ink composition which is attached to the recording surface is heated at a temperature of 40°C or more. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to an ink jet recording method in which the effect of image quality and the like is improved when printing with a water-based ink on a recording medium (so-called non-coated plastic medium or the like) whose recording surface is a plastic film, particularly at a high duty of 50% or more. More specifically, the present invention relates to an ink jet recording method that improves ink aggregation unevenness and mixed color bleeding of printed matter and improves quick drying.

Conventionally, various techniques have been proposed for the purpose of improving effects such as the image quality of printed matter on a recording medium whose recording surface is a plastic film.

For example, Japanese Patent Application Laid-Open No. 2004-114691 provides an ink-jet ink that provides good water fastness, light fastness, wear resistance, and good adhesion to non-absorbing substrates such as untreated vinyl derivatives. For the purpose of the present invention, an ink jet ink composition comprising an aqueous ink jet ink composition containing a polymer latex containing at least one vinyl halide monomer is used. An ink jet printing method including a process of printing on a paper has been proposed (Patent Document 1).

Japanese Patent Application Laid-Open No. 2004-176057 discloses a glass transition temperature (from −40 ° C. to 150 ° C.) for the purpose of providing an aqueous inkjet ink composition suitable for printing on a hydrophobic surface.
An aqueous inkjet ink composition suitable for printing on a hydrophobic surface has been proposed comprising an aqueous emulsion polymer having a Tg); a pigment; and a water-soluble surface agent (Patent Document 2).
Additional advantages in adhesion and image quality when using such ink compositions typically occur when the surface is preheated before image drops are ejected onto the surface.

Japanese Patent Application Laid-Open No. 2004-250659 discloses a method of printing ink using a thermosetting resin on a medium (Patent Document 3).

In JP-A-2006-22328, a) i) an aqueous vehicle; ii) a self-dispersing pigment; iii) a silicone-containing surfactant; iv) a polymer having a glass transition temperature (Tg) of −40 ° C. to 150 ° C. A method of printing an image on a hydrophobic substrate comprising: jetting an aqueous inkjet ink composition comprising: onto a hydrophobic surface; and b) drying the aqueous inkjet ink composition. A method that further includes a step of heating the image shown above before the drying step is disclosed (Patent Document 4).

However, the techniques disclosed in Patent Documents 1 to 4 have a problem that the image quality of the printed image is not improved.

Furthermore, Japanese Patent Application Laid-Open No. 10-279871 aims to provide an ink composition that can reduce ink droplet ejection in the wrong direction and nozzle failure, and provide high print quality at high resolution and high speed, and its printing method. , 1,2-alkyldiol, polyorganosiloxane wetting agent, and 2-pyrrolidone are disclosed (Patent Document 5). However, this ink composition is not compatible with plastic media having no ink absorbing layer.

JP 2004-114691 A JP 2004-176057 A JP 2004-250659 A JP 2006-22328 A Japanese Patent Laid-Open No. 10-279871

Therefore, the present invention improves the quick drying property by improving ink aggregation unevenness and color mixing bleeding when printing with a water-based ink on a recording medium whose recording surface is a plastic film, particularly at a high duty of 50% or more. Another object of the present invention is to provide an ink jet recording method.

The present inventor has achieved the above object by providing the following invention.
1. A recording method in which droplets of a water-based ink composition are ejected onto a recording medium having a recording surface made of a plastic film and attached to the recording surface, and printing is performed. The water-based ink composition includes a colorant, 0 Using an aqueous ink composition containing at least 1% by weight to 1.5% by weight of a silicon-based surfactant, an acetylene glycol-based surfactant, a pyrrolidone derivative, a thermoplastic resin, and water, it is adhered to the recording surface. An ink jet recording method in which the water-based ink composition is heated to 40 ° C. or higher.

2. The silicon surfactant is a polysiloxane compound, the acetylene glycol surfactant is 3,6-dimethyl-4-octyne-3,6-diol, and the pyrrolidone derivative is N-methylpyrrolidone. 2. The inkjet recording method according to 1 above.

3. The 1 or 2 above, wherein a weight ratio (the former: the latter) of the addition amount of the silicon-based surfactant and the acetylene glycol-based surfactant in the water-based ink composition is 1: 100 to 15:10. Inkjet recording method.

4). Any of 1 to 3 above, wherein the weight ratio of the addition amount of the acetylene glycol surfactant and the thermoplastic resin (the former: the latter) in the water-based ink composition is 1: 3 to 5: 3. The ink jet recording method described in 1.

5). The addition amount of the pyrrolidone derivative in the water-based ink composition is 4.0 wt% to
5. The ink jet recording method according to any one of 1 to 4, which is 25.0% by weight.

6). 6. The ink jet recording method according to any one of 1 to 5, wherein the colorant is a pigment, and the pigment is dispersed in an aqueous ink composition.

7). The inkjet recording method according to any one of 1 to 6, wherein the water-based ink composition further comprises a low surface tension organic solvent.

8). The low surface tension organic solvent is diethylene glycol monobutyl ether, or
8. The ink jet recording method as described in 7 above, which is triethylene glycol monobutyl ether.

9. The inkjet recording method according to any one of 1 to 8, wherein the aqueous ink composition further comprises a wetting agent.

10. 10. The ink jet recording method according to any one of 1 to 9, wherein the heat treatment is performed by heater heating or hot air drying.

11. A recorded matter in which an image is formed using the ink jet recording method described in any one of 1 to 10 above.

According to the present invention, it is possible to improve ink quick-drying by improving ink aggregation unevenness and mixed color bleeding when printing on a recording medium whose recording surface is a plastic film with water-based ink, particularly at a high duty of 50% or more. Inkjet recording methods can be provided. In addition, with this recording method, a recorded matter with high image quality and excellent abrasion resistance can be obtained.

Hereinafter, the ink jet recording method according to the present invention will be described based on preferred embodiments thereof.

The ink jet recording method of the present invention is a recording method for performing printing by ejecting droplets of an aqueous ink composition onto a recording medium having a recording surface made of a plastic film and attaching the droplets to the recording surface. An aqueous ink composition containing at least a colorant, 0.1 wt% to 1.5 wt% silicon surfactant, acetylene glycol surfactant, pyrrolidone derivative, thermoplastic resin, and water as a composition. In this method, the water-based ink composition attached to the recording surface is heated to 40 ° C. or higher.

Since this invention consists of this structure, the said effect can be achieved. That is, it is possible to perform printing that suppresses ink aggregation and color mixing bleeding when printing with a water-based ink at a high duty of 50% or more on a recording medium whose recording surface is a plastic film. Therefore, it is possible to obtain a recorded material having high image quality and excellent abrasion resistance, such as a plastic media printed material having a bright color.

Inkjet Recording Method As described above, the inkjet recording method according to the present invention performs printing by ejecting droplets of an aqueous ink composition onto a recording medium having a recording surface made of a plastic film and attaching it to the recording surface. It is. In this case, printing with a high duty of 50% or more is preferable in terms of excellent effect.

In the recording method of the present invention, as described above, the water-based ink composition adhered to the recording surface is heated to 40 ° C. or higher. Such heating evaporates water in the aqueous ink composition on the recording medium after printing, promotes drying of the aqueous ink composition, and forms a film (resin film) with a thermoplastic resin in the aqueous ink composition. Can be made.
The heating temperature is preferably 40 to 60 ° C. When the heating temperature exceeds 60 ° C., depending on the type of plastic film used on the recording surface of the recording medium, it becomes difficult to convey the recording medium due to softening or deformation, and shrinkage after heating occurs. For this reason, it is preferable that the upper limit of the heating temperature at the time of printing shall be 60 degreeC.

In the course of this operation, the solvent containing water contained in the water-based ink composition can be evaporated, so that it is considered that the adhesion between the plastic and the formed resin film can be further strengthened. 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. The heating conditions other than the heating temperature may be any conditions as long as the resin contained in the water-based ink composition can form a resin film by heating. And can be set as appropriate. For example, in the case of heater heating or hot air drying, the heating time can be performed under the conditions of 1 minute to 1 day (preferably 3 minutes to 18 hours).

Also, printing can be performed by feeding a preheated recording medium to the printer and printing the aqueous ink composition on the recording medium, or by incorporating a heater in the portion (platen) that supports the recording medium in the printing portion of the printer. However, a method of heating the water-based ink composition on the recording medium, a method combining these, and the like can also be employed.

A recording medium whose recording surface is a plastic film is not subjected to surface treatment for ink jet printing (for example, has no ink absorption layer), and the recording medium itself is a conventional film such as paper in addition to a plastic film. And those obtained by coating a plastic film on the recording medium substrate and those obtained by bonding a plastic film on the substrate. Here, the plastic is not particularly limited, and examples thereof include vinyl chloride, polyethylene terephthalate (PET), polycarbonate, polystyrene, and polyurethane.

Water-based ink composition As described above, the water-based ink composition used in the recording method of the present invention includes a colorant, 0.1
It contains at least a silicon-based surfactant, an acetylene glycol-based surfactant, a pyrrolidone derivative, a thermoplastic resin, and water in an amount of 1.5% to 1.5% by weight.

The water-based ink composition used in the present invention has an amount of a component that dissolves the plastic film depending on the state of the plastic film used on at least the recording surface of the recording medium and the type of the material, and depending on the drying conditions of the ink. Therefore, the ink application amount can be appropriately changed according to the reproducibility of the image.

The thermoplastic resin is usually dispersed in a water-based ink composition. In other words, the water-based ink composition is preferably a dispersion medium comprising at least a specific amount of a silicon-based surfactant, an acetylene glycol-based surfactant, a pyrrolidone derivative, and water as a main solvent, and the dispersion medium. (Or a thermoplastic resin dispersed together with the pigment when the thermoplastic resin also functions as a pigment dispersant). Here, the colorant in the water-based ink composition is preferably a pigment, and at this time, the pigment is dispersed in the water-based ink composition. The aqueous ink composition preferably further comprises a low surface tension organic solvent. The aqueous ink composition can further comprise a wetting agent.

Silicon-based surfactant In the present invention, the content of the ink composition as a whole is 0.1% by weight from the viewpoint of uniformly spreading the ink while suppressing uneven aggregation and bleeding of the ink on the recording medium after printing. 1.5% by weight of silicon-based surfactant is used.
As the silicon-based surfactant, a polysiloxane compound or the like is preferably used, and examples thereof include polyether-modified organosiloxane.
Examples of the polyether-modified organosiloxane include compounds represented by the following formula (I).

（上記式中、Ｒ₁〜Ｒ₉は、独立して、Ｃ１−６アルキル基を表し、ｊおよびｋは、独立
して１以上の整数を表し、ＥＯはエチレンオキシ基を表し、ＰＯはプロピレンオキシ基を
表し、ｍおよびｎは０以上の整数を表すが、但しｍ＋ｎは１以上の整数を表し、ＥＯおよ
びＰＯは、［ ］内においてその順序は問わず、ランダムであってもブロックであっても
よい。）

(In the above formula, R _{1 to} R ₉ independently represent a C 1-6 alkyl group, j and k independently represent an integer of 1 or more, EO represents an ethyleneoxy group, and PO represents propylene. Represents an oxy group, and m and n represent an integer of 0 or more, provided that m + n represents an integer of 1 or more, and EO and PO are in the order in [] and may be a block even if random. May be.)

In particular, j + k is preferably 11 to 300, more preferably 11 to 100, and more preferably 11 to 50, from the viewpoint of preventing aggregation unevenness caused by ink repelling on the recording medium after printing. Is particularly preferred.

The compound of formula (1) is commercially available and can be used. For example, from Big Chemie Japan Co., Ltd., silicon additives BYK-306, BYK-307,
BYK-333, BYK-341, BYK-345, BYK-346, BYK-348, etc. can be used.

As described above, the addition amount of the silicon-based surfactant is 0.1% in order to achieve the effect of the present invention.
% By weight to 1.5% by weight.

Acetylene-based surfactant In the present invention, an acetylene-based surfactant is used because of its action of suppressing aggregation and bleeding of ink on a recording medium after printing in combination with a silicon-based surfactant.

  Examples of the acetylene surfactant include compounds represented by the following formula (i).

（ここで、Ｒ¹¹、Ｒ¹²、Ｒ¹³、およびＲ¹⁴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 Che
micals. 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。

(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 surfactants represented, for example, 2,4,7,9-tetramethyl-5-decyne-4,7
A diol (eg Surfynol 104 from Air Products and Chemicals. Inc.)
3,6-dimethyl-4-octyne-3,6-diol (eg, Air Products and Che
Surfynol 82 manufactured by micals. Inc.) and derivatives of these acetylene glycols (for example, Surfynol 465, 485 manufactured by Air Products and Chemicals. Inc.).

Specific examples of the acetylene surfactant include 3,6-dimethyl-4-octyne-3,6.
-Diols, 2,4,7,9-tetramethyl-5-decyne-4,7-diol and surfactants obtained by adding ethylene oxide or propylene oxide to them, among which high solubility in water and ink 3,6-Dimethyl-4-octyne-3,6-diol is preferred in that it has a small limit on the amount of addition and prevents the printed matter from sticking after the thermoplastic resin is cured because it is a solid at room temperature.

The amount of acetylene surfactant added is, for example, 0.5 to 15 with respect to the total amount of the ink composition.
. It is 0% by weight, preferably 1.0-10.0% by weight.

The weight ratio (the former: latter) of the addition amount of the silicon-based surfactant and the acetylene glycol-based surfactant described above is 1: 100 from the viewpoint of suppressing ink aggregation unevenness and color mixing bleeding.
It is preferably ˜15: 10.

Pyrrolidone derivative The water-based ink composition contains pyrrolidone in consideration of the balance between the spread of the ink by the silicon surfactant and the acetylene glycol surfactant on the recording medium after printing and the solidification of the thermosetting resin described later. Further derivatives can be added.

Specific examples of the pyrrolidone derivative include N-methylpyrrolidone, N-ethylpyrrolidone,
N-vinylpyrrolidone, 2-pyrrolidone and the like can be mentioned. Among them, N-methylpyrrolidone is preferable in terms of quick drying and promotion of film formation of a thermoplastic resin.

The addition amount of the pyrrolidone derivative is preferably 2.0% by weight to the total amount of the ink composition.
It is 25.0% by weight, more preferably 4.0 to 25.0% by weight.

Thermoplastic resin The water-based ink composition comprises a thermoplastic resin from the viewpoint of solidifying an ink containing a silicon-based surfactant having low volatility. This thermoplastic resin is dispersed in the water-based ink composition. As the thermoplastic resin, a resin soluble or insoluble in the medium of the water-based ink composition can be used. As the resin soluble in the medium of the water-based ink composition, a resin dispersant used for dispersing the above-mentioned pigment can be preferably used. The resin insoluble in the medium of the water-based ink composition is preferably added to the water-based 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 preferably 150 nm.
Less than about, 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 polymer such as polyvinyl chloride or copolymer thereof, polyvinylidene chloride, fluororesin, or fluororubber; nitrogen-containing vinyl polymer such as polyvinyl carbazole, polyvinyl pyrrolidone or A copolymer thereof, polyvinyl pyridine, or polyvinyl imidazole; a diene polymer such as polybutadiene or a copolymer thereof, polychloroprene, or polyisoprene (butyl rubber); or other ring-opening polymerization resin, condensation polymerization resin, Alternatively, a 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,
Polyoxyethylene alkyl ether sulfate ammonium salts), nonionic surfactants (eg, polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl) Amine, polyoxyethylene alkylamide, etc.), and two or more of these may be used in combination.

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, the same one used for normal radical polymerization is used,
For example, potassium persulfate, ammonium persulfate, hydrogen peroxide, azobisisobutyronitrile, benzoyl peroxide, dibutyl peroxide, peracetic acid, cumene hydroperoxide, t-butylhydroxyperoxide, paramentane hydroxyperoxide, etc. Can be mentioned. When the polymerization reaction is performed in water, a water-soluble polymerization initiator is preferable. As an emulsifier, for example,
In addition to sodium lauryl sulfate, those generally used as anionic surfactants, nonionic surfactants or amphoteric surfactants, and mixtures thereof may be mentioned. These can be used in combination of two or more.

The ratio of the resin and water as the dispersed phase component is preferably 6 with respect to 100 parts by weight of the resin.
The range of 0 to 400 parts by weight, more preferably 100 to 200 parts by weight is appropriate.

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 and E-5002
(Styrene-acrylic resin emulsion; manufactured by Nippon Paint Co., Ltd.), Boncoat 40
01 (acrylic resin emulsion; manufactured by Dainippon Ink & Chemicals, Inc.), Boncoat 5
454 (styrene-acrylic resin emulsion; manufactured by Dainippon Ink & Chemicals, Inc.),
SAE1014 (styrene-acrylic resin emulsion; manufactured by Nippon Zeon Co., Ltd.) or Cybinol SK-200 (acrylic resin emulsion; manufactured by Seiden Chemical Co., Ltd.) can be used.

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.

From the viewpoint of long-term storage stability and ejection stability of the water-based ink composition, the resin fine particles preferably used in the present invention have a particle size in the range of 5 to 400 nm, more preferably in the range of 50 to 200 nm.

The thermoplastic resin is preferably contained in the range of 0.1 to 15.0% by weight in terms of solid content, and in the range of 0.5 to 10.0% by weight, based on the total amount of the aqueous ink composition. It is more preferable. In the water-based ink composition, if the resin component is too small, the ink film formed on the plastic surface may become thin and adhesion to the plastic surface may be insufficient. If the resin component is too much, the dispersion of the resin may become unstable during storage of the ink composition, or the resin component may be agglomerated and solidified due to slight evaporation of water, and a uniform film may not be formed.

The addition amount of the thermoplastic resin is such that the weight ratio of the addition amount of the acetylene glycol surfactant and the thermoplastic resin (the former: the latter) is 1: 3 to 5: 3. It is preferable in terms of adhesion to the film.

Colorant The aqueous ink composition used in the present invention comprises a colorant. Here, as the colorant,
Examples thereof include dyes and pigments. In the present invention, the colorant is preferably a pigment.
The dye is not particularly limited, but may be an acid dye, a direct dye, a reactive dye,
Basic dyes can be used.

When a pigment is used as the colorant, the aqueous ink composition can contain any pigment conventionally used in water-based inkjet recording ink compositions. 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.

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, thioindigo pigments, isoindolinone pigments, or quinophthalone pigments), dye chelates (eg, basic dye-type chelates or acidic dye-type chelates), nitro pigments, nitroso pigments, or Aniline black or the like can be used. Of these pigments, it is preferable to use a pigment having good affinity with water.

More specifically, as a black ink pigment, for example, carbon black (C.I.) such as furnace black, lamp black, acetylene black, or channel black.
. Pigment black 7), or metal pigments such as copper oxide, iron oxide (CI pigment black 11) or titanium oxide, and organic pigments such as aniline black (CI pigment black 1) Can do.

Specific examples of suitable carbon black include carbon black manufactured by Mitsubishi Chemical Corporation, No. 2300, 900, MCF88, no. 20B, no. 33, no. 40,
No. 45, no. 52, MA7, MA8, MA100, No2200B and the like. Color black FW1, FW2, FW2V, F as carbon black made by Degussa
W18, FW200, S150, S160, S170, Pretex 35, U, V, 14
0U, special black 6, 5, 4A, 4, 250 and the like. As carbon black made by Columbian Carbon, Conductex SC, Raven 1255, 5750
5250, 5000, 3500, 1255, 700 and the like. As Cabot carbon black, Rebot 400R, 330R, 660R, Mogul L, Monarch 700, 800, 880, 900, 1000, 1100, 1300, 1
400, Elftex 12 and the like.

Examples of color ink pigments include C.I. I. Pigment Yellow 1 (Fast Yellow G),
3, 12 (disazo yellow AAA), 13, 14, 17, 23, 24, 34, 35, 3
7, 42 (yellow iron oxide), 53, 55, 74, 81, 83 (disazo yellow HR), 9
5, 97, 98, 100, 101, 104, 108, 109, 110, 117, 120,
138, 153, 154; I. Pigment Red 1, 2, 3, 5, 17, 22 (Brilliant First Scarlet), 23, 31, 38, 48: 2 (Permanent Red 2B (Ba)), 48: 2 (Permanent Red 2B (Ca)), 48 : 3 (Permanent Red 2B (Sr)), 48: 4 (Permanent Red 2B (Mn)), 49: 1, 5
2: 2, 53: 1, 57: 1 (Brilliant Carmine 6B), 60: 1, 63: 1, 63
: 2, 64: 1, 81 (Rhodamine 6G rake), 83, 88, 92, 101 (Bengara), 104, 105, 106, 108 (Cadmium red), 112, 114, 122 (
Quinacridone magenta), 123, 146, 149, 166, 168, 170, 172,
177, 178, 179, 185, 190, 193, 209, 219; I. Pigment violet 1 (rhodamine lake), 3, 5: 1, 16, 19 (quinacridone red), 23, 38; I. Pigment Blue 1, 2, 15 (phthalocyanine blue R), 15: 1, 15: 2, 15: 3 (phthalocyanine blue G), 15: 4, 15: 6
(Phthalocyanine blue E), 16, 17: 1, 56, 60, 63; etc. can be used.

The particle diameter of the pigment is not particularly limited, but is preferably 25 μm as the average particle diameter.
Below, 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 pigment content is preferably 0.5 to 15% by weight, more preferably 1.0 to 10.0% by weight, based on the entire ink composition.

Low Surface Tension Organic Solvent The water-based ink composition can comprise a low surface tension organic solvent, if necessary.
Examples of the low surface tension organic solvent include monohydric alcohols and polyhydric alcohol derivatives.

As monohydric alcohol, C1-C4 monohydric alcohol, for example, 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 represents 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 1 to 8, preferably 1 to
4 is an integer of 4, provided that at least one of R ²¹ and R ^{22 is} a C 3-6 alkyl 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.

As the low surface tension organic solvent, diethylene glycol monobutyl ether and triethylene glycol monobutyl ether are preferable.

The content of the low surface tension organic solvent is, for example, 0 to 10.0% by weight, preferably 2.0 to 8.0% by weight, based on the total amount of the ink composition.

Although various physical properties of the water-based ink composition can be appropriately controlled, according to a preferred embodiment of the present invention, the viscosity of the water-based ink composition is preferably 25 mPa · sec or less, more preferably 10
mPa · sec or less (25 ° C.). When the viscosity is within this range, the aqueous ink composition can be stably ejected from the ink ejection head. The water-based ink composition 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. It is about the range.

Wetting agent For water-based ink compositions, considering the ease of handling and storage of the water-based ink composition,
If necessary, wetting agents other than the above-described pyrrolidone derivatives can be further added. By including the wetting agent, it is possible to prevent aggregation and solidification of the resin component due to water evaporation, prevent clogging of the nozzles of the ink jet head during ink jet application, and ensure ejection stability.

As the wetting agent, for example, water-soluble polyhydric alcohols, particularly divalent to 2-10 carbon atoms
Examples include pentavalent alcohols; nitrogen-containing hydrocarbon solvents such as formamides, imidazolidinones, or amines; sulfur-containing hydrocarbon solvents. You may use these in combination of 2 or more types.

Examples of the water-soluble polyhydric alcohol include divalent to trivalent alcohols having 3 to 10 carbon atoms such as glycerin, ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, hexylene glycol, 1,2,6- One or more hexanetriols can be used in combination.

The content of the wetting agent is, for example, 0 to 20.0% by weight, preferably 1.0 to 10.0% by weight, based on the total amount of the aqueous ink composition. By setting it as such a range, clogging prevention property or discharge stability can be ensured. When there is too much content, it may become a dry defect.

Main solvent The water-based ink composition comprises water as a main solvent as described above.
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. Further, when water sterilized by ultraviolet irradiation or addition of hydrogen peroxide is used, it is preferable because generation of mold and bacteria can be prevented when the ink composition is stored for a long period of time.

Other components The water-based ink composition can achieve a desired effect by including each of the components described above. However, if necessary, an antiseptic / antifungal agent, a pH adjuster, a dissolution aid, an oxidation agent, and the like. It may further contain an inhibitor, a nozzle clogging preventive agent, and the like.

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,
Alternatively, ureas such as N-methyl-2-pyrrolidone, urea, thiourea and tetramethylurea, allophanates such as allophanate and methylallohanate, biurets such as biuret, dimethylbiuret and tetramethylbiuret, L-ascorbic acid And salts thereof. Furthermore, urea, thiourea, ethylene urea or the like can be added for the purpose of preventing nozzle drying.

Production of water-based ink composition The water-based ink composition used in the present invention is prepared by mixing each of the above-mentioned blending components individually or in the form of a pigment dispersant or a resin emulsion, and appropriately mixing and dissolving (or dispersing) ) And then, if necessary, it can be prepared by removing impurities by filtration.

According to one preferred embodiment of the present invention, in the aqueous ink composition, the silicon surfactant is a polysiloxane compound, and the acetylene glycol surfactant is 3,6-dimethyl-4-octyne-3,6. -Diol and the pyrrolidone derivative is preferably N-methylpyrrolidone. By using such a combination of water-based ink compositions, it is possible to obtain a high-quality printed matter printed at a high duty of 50% or more.

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.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and test examples of the present invention. However, the present invention is not limited to the examples.

[Preparation of ink]
Ink compositions having the following compositions 1 to 6 were prepared.

Composition 1 Composition 2 Composition 3 Composition 4 Composition 5 Composition 6
Pigment 4.0 4.0 4.0 4.0 4.0 4.0
Pigment-dispersed thermoplastic resin 2.0 2.0 2.0 2.0 2.0 2.0
Thermoplastic resin emulsion 4.0 4.0 4.0 4.0 4.0 4.0
Silicon-based surfactant 0.1 1.5 0.5 0.05 1.5 1.5
Acetylene glycol surfactant 10.0 1.0 5.0 10.0 − −
Triethylene glycol − − − − 4.0
N-methylpyrrolidone 25.0 25.0 25.0 25.0 25.0 25.0
Water 54.9 62.5 59.5 55.0 63.5 59.5
(The blending amount unit indicates “% by weight”.)

The ink compositions having compositions 1 to 3 are used in Examples 1 to 3 for the recording method of the present invention for heating to 40 ° C. or higher and Comparative Examples 4 to 6 for the comparative example for heating to less than 40 ° C. The ink compositions having compositions 4 to 6 are Comparative Examples 1 to 3 and Comparative Examples 7 to 7, respectively.
9 is used for the recording method of the comparative example.

For each composition, cyan, magenta, yellow, and black ink compositions (4 types) containing the following pigments were used in the examples according to the present invention.
C. I. Pigment Blue 15: 3 (C: cyan ink composition)
C. I. Pigment Violet 19 (M: magenta ink composition)
C. I. Pigment Yellow 74 (Y: yellow ink composition)
C. I. Pigment Black 7 (K: Black ink composition)

Further, BYK-348 (trade name, polyether-modified organosiloxane manufactured by Big Chemie Japan Co., Ltd.) was used as the silicon surfactant in each ink composition.
The details of the acrylic dispersion resin and the acrylic emulsion are as follows.
Pigment dispersant thermoplastic resin: styrene-acrylic acid copolymer (molecular weight 1000 to 1000
0, acid value 100-300)
-Thermoplastic resin emulsion: acrylic acid-acrylic acid ester copolymer (molecular weight 10
00-10000, glass transition temperature 10 ° C-100 ° C)

[Print 1]
Composition 1 prepared above was applied to a cold laminate film PG-50L (PET media) manufactured by Lamy Corporation as a recording medium having a recording surface of a plastic film.
A recording medium set in the sheet feeder portion using an ink jet printer (PX-G900; manufactured by Seiko Epson Corporation) filled with four colors of C, M, Y, and K for each of the ink compositions -6. Heat to 70 ° C with a dryer and the recording medium is 45 ° C during printing
Immediately thereafter, a pattern in which two colors contact each other at 40% to 100% duty shown in Tables 1 and 2 was printed at a resolution of 1440 dpi in width and 1440 dpi in length.

Here, “Duty” refers to the percentage of ink dots arranged in a total of 2073600 divisions obtained by dividing 1 square inch into 1440 horizontal and 1440 vertical in the case of horizontal 1440 dpi and vertical 1440 dpi.

[Evaluation of printed matter]
For each of the obtained printed materials, the following bleeding and aggregation were evaluated. The results are shown in Tables 1 and 2.
1. Bleeding: The presence / absence of bleeding at the portion where the two colors of the printed pattern are in contact with each other (examined where no bleeding occurs) and with generated x was examined with each duty and evaluated according to the following criteria.
Evaluation criteria A: ○ up to a duty of 60%, and printing is possible without pre-leading to this duty.
B: ○ up to a duty of 50%, and printing is possible without pre-leading to this duty.
C: ○ up to Duty 40%, and printing is possible up to this Duty without pre-leading.
D: Duty of 40% or more is x, and bleeding occurs when printing at Duty of 40%.

2. Aggregation: The presence or absence of occurrence of shading unevenness in the monochromatic solid part (existence of non-uniformity ◯, generated x) was examined with each duty and evaluated according to the following criteria.
Evaluation criteria A: ○ up to Duty 70%, and printing is possible up to this Duty without uneven aggregation.
B: ○ up to a duty of 60%. Printing is possible up to this duty without aggregation unevenness.
C: ○ up to Duty 50%, and printing is possible up to this Duty without aggregation unevenness.
D: Duty of 50% or more is x, and the aggregation unevenness occurs in the printing of Duty 50%.

[Evaluation of printing 2 and printed matter]
40% to 40% as shown in Tables 3 and 4 except that the recording medium set in the sheet feeder was heated to 60 ° C. with a dryer so that the recording medium was 35 ° C. during printing.
A pattern in which two colors are in contact with each other at 100% duty is 1440 dpi wide and 1 vertical
Printed at a resolution of 440 dpi. And about the obtained printed matter, evaluation similar to the case of the printing 1 was performed. The results are shown in Tables 3 and 4.

The present invention is an ink jet recording in which quick aggregation is improved by improving ink aggregation and color mixing bleeding when printing with a water-based ink on a recording medium whose recording surface is a plastic film, particularly at a high duty of 50% or more. The present invention has industrial applicability as a recorded material having high image quality and excellent abrasion resistance by the method and the recording method.

Claims (11)

A recording method in which droplets of a water-based ink composition are ejected onto a recording medium whose recording surface is a plastic film and attached to the recording surface for printing,
An aqueous ink containing at least a colorant, 0.1 wt% to 1.5 wt% silicon surfactant, acetylene glycol surfactant, pyrrolidone derivative, thermoplastic resin, and water as the aqueous ink composition. Using the composition,
An ink jet recording method in which the water-based ink composition attached to a recording surface is heated to 40 ° C. or higher. The silicon surfactant is a polysiloxane compound, the acetylene glycol surfactant is 3,6-dimethyl-4-octyne-3,6-diol, and the pyrrolidone derivative is N-methylpyrrolidone. The inkjet recording method according to claim 1, wherein In the water-based ink composition, a weight ratio (the former: latter) of the addition amount of the silicon surfactant and the acetylene glycol surfactant is 1: 100 to 15:10.
The ink jet recording method according to claim 1 or 2. The weight ratio (the former: latter) of the addition amount of the acetylene glycol surfactant and the thermoplastic resin in the water-based ink composition is 1: 3 to 5: 3. An ink jet recording method according to claim 1. The addition amount of the pyrrolidone derivative in the water-based ink composition is 4.0% by weight to 25%.
. The inkjet recording method according to claim 1, wherein the inkjet recording method is 0% by weight. The colorant is a pigment, and the pigment is dispersed in an aqueous ink composition.
The inkjet recording method in any one of -5. The inkjet recording method according to claim 1, wherein the water-based ink composition further comprises a low surface tension organic solvent. The inkjet recording method according to claim 7, wherein the low surface tension organic solvent is diethylene glycol monobutyl ether or triethylene glycol monobutyl ether. The inkjet recording method according to claim 1, wherein the aqueous ink composition further comprises a wetting agent. The inkjet recording method according to claim 1, wherein the heat treatment is performed by heater heating or hot air drying. A recorded matter in which an image is formed using the ink jet recording method according to claim 1.