JP2011201230A - Inkjet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet recording method by which an image, that has quick drying properties, only a few ink blot, high image quality and excellent scratch resistance, can be obtained on a recording medium having the unabsorbent or low-absorbency surface to be recorded.SOLUTION: The inkjet recording method comprises the steps of: ejecting a water-based ink composition to the recording medium exhibiting un-absorbency or low absorbency to inks while heating the recording medium to 40-60°C; and drying the water-based ink composition ejected to the recording medium by heating the recording medium to 40-90°C. The water-based ink composition contains water, at least one water-insoluble colorant, a solvent having low surface tension, a surfactant, at least one nitrogen-containing solvent selected from 2-pyrrolidone and N,N'-dimethylpropylene urea, and a water-insoluble thermoplastic resin particle including a urethane resin at the least. The content of the nitrogen-containing solvent is 3-15 mass% and that of the water-insoluble thermoplastic resin particle is 1-8 mass%.

Description

  The present invention relates to a printing method using an inkjet recording method.

  The ink jet recording method is a recording method in which printing is performed by ejecting small droplets of ink from fine nozzles formed on an ink jet head and causing them to fly and adhere to a recording medium. The inkjet recording method has been conventionally used mainly for printing on a water-absorbing surface such as paper, but has a feature that a high-resolution and high-quality image can be printed at high speed with a relatively inexpensive apparatus. Therefore, in recent years, a technique for printing on a non-water-absorbing recording medium using an ink jet recording method has been proposed.

  For example, for an ink jet recording method for a non-absorbing recording medium that does not absorb ink or a low-absorbing recording medium, a non-aqueous ink mainly composed of an organic solvent has been used. Non-aqueous inks have excellent advantages such as fast drying, water resistance, and prevention of image bleeding.However, since the solvent is volatilized on the surface of the recording medium, an image is formed. And toxicity was a problem. Furthermore, since there is a concern about the environmental impact of organic solvents, there is an ink jet recording method using a water-based ink that is safer and has less environmental impact even for non-ink-absorbing or low-absorbing recording media. It is being considered.

  For the purpose of providing an aqueous inkjet ink composition suitable for printing on a hydrophobic surface, an aqueous emulsion polymer having a glass transition temperature (Tg) of −40 ° C. to 150 ° C .; a pigment; and a hydrophobic Patent Document 1 proposes an aqueous inkjet ink composition suitable for printing on a porous surface. 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. However, the aqueous emulsion polymer having a glass transition temperature (Tg) of −40 ° C. to 150 ° C. is an acrylic resin, and a hydrophobic surface other than polyvinyl chloride has not been sufficiently studied.

  Patent Document 2 discloses an ink jet printer using an ink containing a urethane resin as an ink containing resin particles other than acrylic. Resin particles containing 10 to 60% by weight of urethane resin emulsion as resin particles, solid content of 30% by weight or more and 0 to 90% by weight of acrylic resin are mentioned, and the image quality is improved by having a drying mechanism. It is described that it improves. However, in Patent Document 2, there is a problem of suppression of show-through in double-sided printing of plain paper, and no study has been made on rubbing resistance that is a problem of water-based ink in printing on a non-absorbent recording medium.

JP 2004-176057 A JP 2003-235023 A

  One of the objects in some embodiments of the present invention is that a recording surface has a quick drying property against a non-absorbing or low-absorbing recording medium, has low ink bleeding, high image quality, and scratch resistance. Is to provide an ink jet recording method that can obtain an excellent image.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

[Application Example 1] One aspect of the ink jet recording method according to the present invention is as follows.
A first step in which a non-ink-absorbing or low-absorbing recording medium is heated to a temperature range of 40 ° C. or more and 60 ° C. or less by an ink jet recording apparatus to discharge droplets of a water-based ink composition; And a second step of drying the water-based ink composition discharged onto the recording medium by heating to a temperature range of 40 ° C. or higher and 90 ° C. or lower, wherein the water-based ink composition Is a nitrogen-containing solvent comprising at least one selected from water, at least one water-insoluble colorant, a low surface tension solvent, a surfactant, and 2-pyrrolidone and N, N′-dimethylpropyleneurea, Water-insoluble thermoplastic resin particles containing at least a urethane resin, and the 2-pyrrolidone, N, N′-dimethylpropyleneurea in the aqueous ink composition The content of at least one selected nitrogen-containing solvent is 3 to 15% by mass, and the content of water-insoluble thermoplastic resin particles containing at least a urethane resin in the water-based ink composition is 1 to 8% by mass. %.
According to the ink jet recording method of Application Example 1, it is possible to obtain a recording excellent in quick-drying and improved in the abrasion resistance of an image formed on a non-ink-absorbing recording medium.

Application Example 2 In the ink jet recording method described in the application example,
The water-insoluble thermoplastic resin particles are resin particles made of a urethane resin and an acrylic resin.

Application Example 3 In the ink jet recording method described in the application example,
The water-insoluble colorant is a pigment and is characterized by being dispersed in a water-based ink composition with a water-soluble resin.

Application Example 4 In the ink jet recording method described in the application example,
The surfactant is a silicon-based surfactant.

Application Example 5 In the ink jet recording method according to the application example,
The low surface tension solvent is 1,2-hexanediol.

Application Example 6 In the ink jet recording method according to the application example,
The recording medium is heated by a heater or hot air.

  Hereinafter, preferred embodiments of the present invention will be described. The embodiment described below describes an example of the present invention. In addition, the present invention is not limited to the following embodiments, and includes various modifications that are implemented within a range that does not change the gist of the present invention.

1. Inkjet Recording Method An inkjet recording method according to an embodiment of the present invention is an aqueous ink composition in which an ink non-absorbing or low-absorbing recording medium is heated to a temperature range of 40 ° C. or more and 60 ° C. or less by an inkjet recording apparatus. A first step of discharging a droplet of
A second step of heating the recording medium to a temperature range of 40 ° C. or higher and 90 ° C. or lower and drying the water-based ink composition discharged on the recording medium;
An inkjet recording method comprising:
The water-based ink composition includes water, at least one water-insoluble colorant, a low surface tension solvent, a surfactant,
A nitrogen-containing solvent consisting of at least one selected from 2-pyrrolidone and N, N′-dimethylpropyleneurea;
Water-insoluble thermoplastic resin particles containing at least a urethane resin, and
The content of the nitrogen-containing solvent consisting of at least one selected from 2-pyrrolidone and N, N′-dimethylpropyleneurea in the aqueous ink composition is 3 to 15% by mass,
The content of water-insoluble thermoplastic resin particles containing at least a urethane resin in the water-based ink composition is 1 to 8% by mass. In the present invention, “image” indicates a print pattern formed from a group of dots, and includes text printing and solid printing.

1.1. Inkjet recording process In an inkjet recording method according to an embodiment of the present invention, an ink non-absorbing or low-absorbing recording medium is heated to a temperature range of 40 ° C. or more and 60 ° C. or less to eject droplets of an aqueous ink composition. A first step and a second step of heating the recording medium to a temperature range of 40 ° C. or higher and 90 ° C. or lower to dry the water-based ink composition discharged on the recording medium. And

  The inkjet recording apparatus is not particularly limited as long as it can perform recording by ejecting ink droplets and adhering the droplets onto the recording medium, but has a function of heating the recording medium during printing. It is preferable. Here, “when printing” means that after a recording medium is transported to a paper guide section of an ink jet recording apparatus, ink droplets are ejected by the ink jet recording apparatus and the liquid droplets are deposited on the recording medium. The time until the recording medium is transported to the ink drying mechanism.

  Functions that can heat the recording medium include, for example, a print heater function that heats the recording medium by directly contacting the heat source, and infrared rays and microwaves (electromagnetic waves having a maximum wavelength of about 2,450 MHz) without directly contacting the recording medium. Such as a dryer function that irradiates and blows warm air. The print heater function and the dryer function can be used independently or simultaneously. Thereby, the heating temperature at the time of printing can be adjusted.

  Alternatively, ink droplets may be ejected by an ink jet recording apparatus, and the recording medium to which the droplets are attached may be dried by a dryer or a thermostat set to a predetermined temperature.

The ink jet recording method of this embodiment is suitable for printing on a non-ink-absorbing or low-absorbing recording medium.
Examples of the non-ink-absorbing recording medium include those in which a plastic is coated on a base material such as a plastic film or paper, or a material in which a plastic film is adhered. Examples of the plastic film herein include polyvinyl chloride, polyethylene terephthalate, polystyrene, polyurethane, polyethylene, and polypropylene. Examples of the recording medium having low ink absorption include printing paper such as art paper, coated paper, and matte paper.

Here, in this specification, “ink non-absorbing or low-absorbing recording medium” means “the amount of water absorption from the start of contact to 30 msec ^1/2 in the Bristow method is 10 mL / m ² or less. Recording medium ". This Bristow method is the most popular method for measuring the amount of liquid absorbed in a short time, and is also adopted by the Japan Paper Pulp Technology Association (JAPAN TAPPI). For details of the test method, refer to Standard No. of “JAPAN TAPPI Paper Pulp Test Method 2000”. 51 "Paper and paperboard-Liquid absorbency test method-Bristow method".

A wide variety of products are commercially available for non-ink-absorbing or low-absorbing recording media for outdoor exhibitions that require long-term weather resistance and printed materials that require the strength of the recording medium itself. It can be suitably selected from among them depending on the application.
An ink jet recording method using an ink jet recording apparatus can be performed, for example, as follows. First, a water-based ink composition (described later) is ejected as droplets onto a recording medium heated to a temperature range of 40 ° C. to 60 ° C. with a print heater or the like provided in the ink jet recording apparatus. Any of the conventionally known methods can be used as the inkjet ejection method, and in particular, a method of ejecting droplets using the vibration of a piezoelectric element (using an inkjet head that forms ink droplets by mechanical deformation of an electrostrictive element). In the recording method, excellent image recording can be performed.

  Next, the recording medium on which the inkjet image is formed is heated to a temperature range of 40 ° C. or more and 90 ° C. or less by a drying mechanism such as a dryer provided in the inkjet recording device or a thermostat connected to the inkjet recording device, The aqueous ink composition ejected on the recording medium is dried.

  Ink non-absorptivity is obtained by a first step of forming an image by heating a non-ink-absorbing or low-absorbing recording medium to a temperature range of 40 ° C. to 60 ° C. and ejecting the aqueous ink composition as droplets. Alternatively, a high-quality image with little shading unevenness and bleeding can be formed on a low-absorbency recording medium.

  In addition, due to the second step of heating the recording medium on which the inkjet image is formed to a temperature range of 40 ° C. or higher and 90 ° C. or lower, moisture contained in the water-based ink composition discharged onto the recording medium is quickly A film is formed by water-insoluble thermoplastic resin particles (described later) containing at least urethane resin contained in the water-based ink composition by evaporation and scattering. Thus, by forming a film of resin particles on the recording medium, it is possible to obtain a high-quality image with less uneven density and blurring in which the dried ink is firmly adhered to the recording medium in a short time.

  At this time, the heating temperature of the recording medium is in the temperature range of 40 ° C. or more and 60 ° C. or less in the first step, and in the temperature range of 40 ° C. or more and 90 ° C. or less in the second step. It can be adjusted accordingly.

  By setting the heating temperature in the second step to 40 ° C. or higher, evaporation and scattering of the liquid medium in the aqueous ink composition can be promoted. However, the higher the heating temperature in the second step, the higher the temperature of the ink. It is advantageous in terms of drying and abrasion resistance. However, when the heating temperature of the recording medium exceeds 90 ° C., deformation may occur depending on the type of the recording medium, or problems such as shrinkage of a recorded image may occur when the recording medium is heated and cooled. In addition, there are undesirable problems such as an increase in power consumption of the heater used for heating and an increase in exhaust heat from the ink jet printer due to the heating mechanism. Based on these problems, the upper limit of the heating temperature of the recording medium is 90 ° C. It is preferable that

In addition, when using polyvinyl chloride, which is easily deformed at a high temperature, as a recording medium, it is preferable that the heating temperature in the first step and the second step is 60 ° C. or lower. When the heating temperature in the first step exceeds 60 ° C., the recording medium made of polyvinyl chloride is suddenly softened and easily deformed, and it may be difficult to convey the recording medium in the ink jet recording apparatus. On the other hand, if the heating temperature in the second step is less than 40 ° C., the solvent in the water-based ink composition remains, so that film formation of water-insoluble thermoplastic resin particles containing at least a urethane resin becomes insufficient. In some cases, the strength of the recorded image cannot be obtained.
The heating and drying time of the recording medium is not particularly limited as long as the liquid medium present in the water-based ink composition can be evaporated and scattered, and a film of thermoplastic resin particles can be formed. Solvents used, resin particles, printing speed, etc. Can be set as appropriate.

1.2. Hereinafter, the water-based ink composition used in the ink jet recording method according to the embodiment of the present invention will be described in detail.

1.2.1. Thermoplastic Resin Particles The aqueous ink composition used in the ink jet recording method according to this embodiment contains water-insoluble thermoplastic resin particles containing at least a urethane resin. The thermoplastic resin particles are a second step in which the water-based ink composition discharged on the recording medium is dried by heating the recording medium to a temperature range of 40 ° C. or higher and 90 ° C. or lower. Resin particles are formed into a film by the action of the solvent to solidify the ink, and further, the solidified ink is firmly fixed on the recording medium. At this time, since the urethane resin has excellent adhesion to plastics and is not easily peeled off by friction, the recorded matter recorded with the aqueous ink composition containing the resin particles containing the urethane resin is not ink-absorbing. Excellent in abrasion resistance on a recording medium with high resistance.

  Components other than urethane resin of thermoplastic resin particles include, for example, acrylic acid, acrylic ester, methacrylic acid, methacrylic ester, acrylonitrile, cyanoacrylate, acrylamide, olefin, styrene, vinyl acetate, vinyl chloride, vinyl alcohol, vinyl ether. , Vinylpyrrolidone, vinylpyridine, vinylcarbazole, vinylimidazole, vinylidene chloride homopolymer or copolymer, fluororesin, natural resin and the like. The copolymer can be used in any form of a random copolymer, a block copolymer, an alternating copolymer, and a graft copolymer. As the thermoplastic resin particles other than the urethane resin, an acrylic resin or a styrene-acrylic acid copolymer resin, which has high hardness and is hardly scratched, is particularly preferable.

  The form of blending the urethane resin and the other resin of the thermoplastic resin particles is preferably a core-shell type in which the urethane resin is a shell part and the other resin is a core part. By doing so, when the thermoplastic resin particles are coated on the recording medium, the characteristics of the urethane resin and the characteristics of other resins can be effectively applied.

  The thermoplastic resin particles may be added so as to be completely dissolved in the water-based ink composition, or may be contained as particles that are dispersed as particles, that is, in an emulsion state or a suspension state. . The aqueous ink composition used in the ink jet recording method according to this embodiment is preferably contained as resin particles in an emulsion state or a suspension state. By containing the resin particles in an emulsion state or suspension state, the viscosity of the aqueous ink composition can be easily adjusted to an appropriate range in the ink jet recording method according to the present embodiment, so that storage stability and ejection stability are improved. Easy to secure.

  As a thermoplastic resin particle containing said urethane resin, what is obtained by a well-known material and method can be used. For example, those described in JP-A-8-60063 and JP-A-6-329985 may be used. Commercially available products can also be used, for example, Acryte WEM-202U, WEM-030U, WEM-321U, WEM-306U, WEM-162, WBR-183U, WBR-601U, WBR-401U, 3DR-057, 3DR. -829, 3DR-828 (manufactured by Taisei Fine Chemical Co., Ltd.), Aquabrid AU-304 (manufactured by Daicel Chemical Industries, Ltd.) and the like.

  Content of the thermoplastic resin particle containing a urethane resin is 1 mass% or more and 8 mass% or less with respect to the total mass of a water-based ink composition as solid content. Further, the content of the thermoplastic resin particles containing a urethane resin is more preferably 1.5% by mass or more and 5% by mass or less as a solid content with respect to the total mass of the aqueous ink composition. When the content of the thermoplastic resin particles is 1% by mass or more, the image can be fixed on the recording medium, and when it is 1.5% by mass or more, the image can be fixed more firmly. On the other hand, when the content of the thermoplastic resin particles is less than 1% by mass relative to the total mass of the water-based ink composition, the action of the thermoplastic resin particle film fixing the solid content in the water-based ink composition decreases. As a result, solidification and fixing of the image may be insufficient. Further, if the content of the thermoplastic resin particles exceeds 8% by mass with respect to the total mass of the water-based ink composition, the ink ejection becomes unstable or the nozzles of the ink jet head are blocked and the ink cannot be ejected. In some cases, the solid content of the thermoplastic resin particles is preferably 8% by mass or less, and more preferably 5% by mass or less from the viewpoint of stable ink ejection.

1.2.2. Solvent The aqueous ink composition used in the ink jet recording method according to this embodiment contains a nitrogen-containing organic solvent composed of at least one selected from 2-pyrrolidone and N, N′-dimethylpropyleneurea.

The nitrogen-containing organic solvent consisting of at least one selected from 2-pyrrolidone and N, N′-dimethylpropyleneurea is excellent in thermoplastic resin particles and polyvinyl chloride which is a kind of non-absorbent recording medium material. Acts as a solubilizer or softener.
The nitrogen-containing organic solvent consisting of at least one selected from 2-pyrrolidone and N, N′-dimethylpropyleneurea has a boiling point of 240 ° C. to 250 ° C., and is concentrated in the heating process to leave an ink residue on the recording medium. In the inside, the concentration is increased to dissolve a part of the thermoplastic resin particles. The dissolved thermoplastic resin imparts an effect of accelerating the formation of a solidified ink containing a colorant as a main component and firmly adhering it onto a non-ink-absorbing or low-absorbing recording medium.

Further, when vinyl chloride is used as a non-ink-absorbing recording medium, a part of the first solvent contained in the aqueous ink composition penetrates into the recording medium to further adhere the ink solidified product and the polyvinyl chloride. At the same time, it has the effect of improving the drying property of the ink.
The content of the nitrogen-containing organic solvent consisting of at least one selected from 2-pyrrolidone and N, N′-dimethylpropyleneurea is 3% by mass to 15% by mass with respect to the total mass of the aqueous ink composition. Further, the content is more preferably 5% by mass or more and 10% by mass or less with respect to the total mass of the water-based ink composition. When the content of the nitrogen-containing organic solvent is 5% by mass or more, the image on the recording medium can be fixed more firmly. Further, if the content of the nitrogen-containing organic solvent is 15% by mass or less, the drying property of the ink on the recording medium is not problematic in practical use, and the content of the nitrogen-containing organic solvent is 10% by mass or less. And the dryness of the image can be further improved. On the other hand, if the nitrogen-containing organic solvent is less than 3% by mass, the formation of a film of thermoplastic resin particles in the aqueous ink composition may be reduced, and the solidification / fixing of the image may be insufficient. On the other hand, if the content of the nitrogen-containing organic solvent exceeds 15% by mass, a part of the first solvent remaining on the surface of the recording medium becomes difficult to evaporate and the image may not be sufficiently dried.

The aqueous ink composition used in the ink jet recording method according to this embodiment further contains a low surface tension solvent.
The low surface tension solvent synergizes with the surfactant to further increase the wettability of the aqueous ink composition with respect to the recording medium, and has an action of uniformly wetting the ink on the recording medium. Here, the solvent having a low surface tension refers to a solvent having a surface tension at room temperature of 40 mN / m or less. By uniformly wetting the ink on the recording medium, it is possible to reduce unevenness in color density and bleeding of the ink on the recording medium.

Examples of the low surface tension solvent include 1,2-alkanediols such as 1,2-pentanediol, 1,2-hexanediol, and 1,2-heptanediol. Among these, 1,2-hexanediol is a 1,6-alkanediol having a boiling point of 223 ° C. and a carbon number of 6, and has a boiling point slightly lower than that of the nitrogen-containing organic solvent. Therefore, it remains in the ink until immediately before the final stage of drying after the water has evaporated, and the recording surface of the formed image is uniformly wetted against the recording medium made of non-absorbing plastic. Excellent in reducing bleeding. On the other hand, 1,2-alkanediols having 5 or less carbon atoms, such as 1,2-pentanediol, have a lower boiling point than 1,2-hexanediol, so that they do not remain until the final stage of drying and the ink is solidified. It is inferior to the action which continues to wet a recording medium uniformly.
In addition, in the case of 1,2-alkanediol having 4 or less carbon atoms, the wettability of the ink with respect to the recording medium whose recording surface is made of non-absorbing plastic is poor, and unevenness of ink density or bleeding may occur. is there. Further, 1,2-alkanediols having 7 or more carbon atoms such as 1,2-heptanediol have poor water solubility of the solvent, and it becomes impossible to add an amount of solvent necessary for ensuring wettability, The storage stability of things may be hindered.

  The content of 1,2-hexanediol, which is a low surface tension solvent, is based on the total mass of the water-based ink composition in order to sufficiently affect the wettability of the ink with respect to a non-ink-absorbing or low-absorbing recording medium. The amount is preferably 3% by mass or more, and preferably 8% by mass or less with respect to the total mass of the water-based ink composition in order not to inhibit the quick drying property of the ink.

  The aqueous ink composition used in the ink jet recording method according to this embodiment can further contain a solvent having a moisturizing action or a low surface tension. For example, ethylene glycol monobutyl ether, diethylene glycol mono-n-propyl ether, ethylene glycol mono-iso-propyl ether, diethylene glycol mono-iso-propyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol mono-t-butyl ether, diethylene glycol mono -N-butyl ether, triethylene glycol mono-n-butyl ether, diethylene glycol mono-t-butyl ether, 1-methyl-1-methoxybutanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-t-butyl ether, propylene Glycol mono-n-propyl ether, propylene glycol mono-iso Propyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol mono-n-butyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-iso-propyl ether, methanol, ethanol, n-propyl alcohol, iso -Propyl alcohol, 2,2-dimethyl-1-propanol, n-butanol, 2-butanol, tert-butanol, iso-butanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl- 2-butanol, n-pentanol, 2-pentanol, 3-pentanol, tert-pentanol, N-methyl-2-pyrrolidone, tetramethylurea, dimethyl sulfoxide, 2-pyrrolidone, 1,3-dimethyl - imidazolidinone, N, include water-soluble solvents such as N'- dimethylpropyleneurea.

1.2.3. Colorant The aqueous ink composition used in the ink jet recording method according to the present embodiment contains a water-insoluble colorant. Water-insoluble colorants include water-insoluble dyes or pigments, with pigments being preferred. The pigment is not only insoluble or hardly soluble in water, but also has a property of not easily fading to light, gas, or the like. For this reason, a recorded matter printed with an ink composition using a pigment is excellent in water resistance, gas resistance, light resistance and the like, and has good storage stability.

The water-based 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.
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.

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

  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. Examples of carbon blacks manufactured by Degussa include color blacks FW1, FW2, FW2V, FW18, FW200, S150, S160, S170, Pretex 35, U, V, 140U, Special Black 6, 5, 4A, 4, 250, etc. It is done. Examples of carbon black manufactured by Columbia Carbon include Conductex SC, Raven 1255, 5750, 5250, 5000, 3500, 1255, 700, and the like. Examples of the carbon black manufactured by Cabot include Regal 400R, 330R, 660R, Mogul L, Monarch 700, 800, 880, 900, 1000, 1100, 1300, 400, Elftex 12 and the like manufactured by Cabot.

  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, 37, 42 (Yellow Iron Oxide), 53, 55, 74, 81, 83 (Disazo Yellow HR), 95, 97, 98, 100, 101, 104, 108, 109, 110, 117, 120, 138, 150, 151, 154, 155, 180, 185, 213; 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, 52: 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, pigment violet 1 (rhodamine lake), 3, 5: 1, 6,19 (quinacridone red), 23 and 38; or C. 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; and the like.

The particle diameter of the pigment is not particularly limited, but the average particle diameter is preferably 25 μm or less, more preferably 2 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 mass, more preferably 1.0 to 10.0% by mass, based on the entire ink composition.

Various methods can be applied to the above pigment in order to make it more stably dispersed and retained in the aqueous ink composition. As the method, for example, a method of dispersing using a water-soluble resin, a method of dispersing using a surfactant, a hydrophilic functional group is chemically and physically introduced on the surface of pigment particles, and then dispersed and / or dissolved. Possible methods are listed. Any of the above-described methods can be used for the water-based ink composition used in the printing method according to the present embodiment, and the methods can be used in a combined form as necessary.
In particular, in a method in which a pigment is dispersed in a water-based ink composition by a water-soluble resin, when the water-based ink recording material adheres to the recording medium, the recording medium and the ink composition and / or solidification in the ink composition is performed. It may increase the adhesion between objects, which is preferable. In addition, a method in which a hydrophilic functional group is chemically and physically introduced on the surface of pigment particles to disperse the pigment in the aqueous ink composition improves the dispersion stability of the pigment, and the storage stability of the aqueous ink composition. Is preferable in terms of improving the quality.

  Water-soluble resins that can be used for pigment dispersion include polyvinyl alcohols, polyvinyl pyrrolidones, polyacrylic acid, acrylic acid-acrylonitrile copolymers, vinyl acetate-acrylic acid ester copolymers, acrylic acid-acrylic acid ester copolymers. Polymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid ester copolymer, styrene-α-methylstyrene-acrylic acid copolymer, styrene-α-methylstyrene -Acrylic acid-acrylic acid ester copolymer, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinylnaphthalene-acrylic acid copolymer, vinylnaphthalene-maleic acid copolymer, vinyl acetate-maleic acid Acid ester copolymer, vinyl acetate-crotonic acid copolymer , Vinyl acetate-acrylic acid copolymer, and salts thereof. Among these, a copolymer of a monomer having a hydrophobic functional group and a monomer having a hydrophilic functional group, and a polymer comprising a monomer having both a hydrophobic functional group and a hydrophilic functional group are particularly preferable. As the form of the copolymer, any form of a random copolymer, a block copolymer, an alternating copolymer, and a graft copolymer can be used.

  Examples of the salt include bases such as ammonia, ethylamine, diethylamine, triethylamine, propylamine, isopropylamine, dipropylamine, butylamine, isobutylamine, diethanolamine, triethanolamine, tri-iso-propanolamine, aminomethylpropanol, and morpholine. And a salt with a functional compound. The addition amount of these basic compounds is not particularly limited as long as it is at least the neutralization equivalent of the water-soluble resin.

  The molecular weight of the water-soluble resin that can be used for dispersing the pigment is preferably in the range of 1,000 to 100,000, more preferably in the range of 3,000 to 10,000, as the weight average molecular weight. When the molecular weight is in the above range, a stable dispersion of the colorant in water can be obtained, and viscosity control when applied to an aqueous ink composition is easy. Moreover, it is preferable that it is the range of 50-300 as an acid value, and it is more preferable that it is the range of 70-150. When the acid value is within this range, the dispersibility of the colorant particles in water can be stably secured, and the water resistance of the printed matter printed with the aqueous ink composition using the colorant particles is good.

  Commercially available products can also be used as the water-soluble resin that can be used for dispersing the pigment described above. Specifically, Joncryl 67 (weight average molecular weight: 12,500, acid value: 213), Joncryl 678 (weight average molecular weight: 8,500, acid value: 215), Joncryl 586 (weight average molecular weight: 4,600) , Acid value: 108), joncryl 611 (weight average molecular weight: 8,100, acid value: 53), joncryl 680 (weight average molecular weight: 4,900, acid value: 215), joncryl 682 (weight average molecular weight) : 1,700, acid value: 238), joncryl 683 (weight average molecular weight: 8,000, acid value: 160), joncryl 690 (weight average molecular weight: 16,500, acid value: 240) , Manufactured by BASF Japan Ltd.).

  Surfactants that can be used to disperse the pigments include alkane sulfonates, α-olefin sulfonates, alkyl benzene sulfonates, alkyl naphthalene sulfonates, acylmethyl taurates, dialkyl sulfosuccinates Anionic surfactants such as alkyl sulfate ester salts, sulfated olefins, polyoxyethylene alkyl ether sulfate ester salts, alkyl phosphate ester salts, polyoxyethylene alkyl ether phosphate ester salts, monoglycerite phosphate ester salts, Amphoteric surfactants such as alkyl pyridium salts, alkyl amino acid salts, alkyl dimethyl betaines, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl esters, polyoxyethylenes Alkylene alkyl amides, glycerol alkyl esters, nonionic surfactants such as sorbitan alkyl esters.

  The amount of the water-soluble resin or the surfactant that can be used for dispersing the pigment to the pigment is preferably 1% by mass to 100% by mass, more preferably 5% by mass to 50% by mass with respect to 1% by mass of the pigment. %. By being in this range, the dispersion stability of the pigment in water can be ensured.

As a method of introducing a hydrophilic functional group into the pigment particle surface chemically and physically so that the pigment can be dispersed and / or dissolved, the hydrophilic functional group can be -OM, -COOM, -CO-, -SO as a hydrophilic functional group in the pigment. ₃ M, —SO ₂ NH ₂ , —RSO ₂ M, —PO ₃ HM, —PO ₃ M ₂ , —SO ₂ NHCOR, —NH ₃ , —NR ₃ (wherein M is a hydrogen atom, an alkali Represents a metal, ammonium, or organic ammonium, and R represents an alkyl group having 1 to 12 carbon atoms, an optionally substituted phenyl group, or an optionally substituted naphthyl group. The method to introduce is mentioned. These functional groups are physically and / or chemically introduced by grafting directly to the pigment particle surface and / or via other groups. Examples of the polyvalent group include an alkylene group having 1 to 12 carbon atoms, a phenylene group which may have a substituent, or a naphthylene group which may have a substituent.

Further, as the surface treatment method, a sulfur-containing treatment agent is used to cause -SO ₃ M and / or -RSO ₂ M (M is a counter ion, hydrogen ion, alkali metal ion, ammonium ion) on the pigment particle surface. Or an organic ammonium ion)) that has been surface-treated so as to chemically bond, that is, the pigment does not have an active proton, has no reactivity with sulfonic acid, and the pigment is insoluble or hardly soluble. In the solvent, the pigment is dispersed, and then surface treatment is performed so that —SO ₃ M and / or —RSO ₂ M are chemically bonded to the particle surface by amidosulfuric acid or a complex of sulfur trioxide and tertiary amine. More preferably, it can be dispersed and / or dissolved in water.

  Various known surface treatment means can be applied as the surface treatment means for grafting the functional group or a salt thereof directly on the surface of the pigment particles or via a polyvalent group. For example, means for treating a commercially available oxidized carbon black with ozone or a sodium hypochlorite solution to further oxidize the carbon black to make the surface more hydrophilic (for example, JP-A-7-258578, JP-A-H10-238707). 8-3498, JP-A-10-120958, JP-A-10-195331, JP-A-10-237349), means for treating carbon black with 3-amino-N-alkyl-substituted pyridium bromide ( For example, JP-A-10-195360 and JP-A-10-330665), an organic pigment is dispersed in a solvent in which the organic pigment is insoluble or hardly soluble, and a sulfone group is introduced onto the pigment particle surface by a sulfonating agent. Means (for example, JP-A-8-283596, JP-A-10-110110, JP-A-10-1101 No. 1), means for dispersing an organic pigment in a basic solvent that forms a complex with sulfur trioxide, treating the surface of the organic pigment by adding sulfur trioxide, and introducing a sulfone group or a sulfonamino group (For example, Unexamined-Japanese-Patent No. 10-110114) etc. are mentioned, However, The preparation means for the surface treatment pigment used by this invention is not limited to these means.

  The functional group grafted on one pigment particle may be single or plural kinds. The type and degree of the functional group to be grafted may be appropriately determined in consideration of the dispersion stability in the ink, the color density, the drying property on the front surface of the inkjet head, and the like.

  As a method of dispersing the pigment in water, the pigment, water, and water-soluble resin are used for the resin dispersant, the pigment, water, and surfactant are used for the surfactant, and the pigment and water are used for the surface-treated pigment. Add water-soluble organic solvent / neutralizer, etc. as necessary to ball mill, sand mill, attritor, roll mill, agitator mill, Henschel mixer, colloid mill, ultrasonic homogenizer, jet mill, ang mill, etc. Can be carried out with a disperser. In this case, as described above, the average particle size of the pigment is preferably 25 μm or less, more preferably 2 μm or less, as described above, from the viewpoint of ensuring dispersion stability of the pigment in water. .

1.2.4. Surfactant The water-based ink composition used in the ink jet recording method according to the present embodiment contains a surfactant. The surfactant has a function of uniformly spreading the ink so as not to cause unevenness of ink density or bleeding on the recording medium.

  The surfactant is preferably a silicon-based surfactant. As the silicon-based surfactant, a polysiloxane compound or the like is preferably used, and examples thereof include polyether-modified organosiloxane. Moreover, a commercial item can be used, for example, BYK-306, BYK-307, BYK-333, BYK-341, BYK-345, BYK-346, BYK-348 (above, trade name, manufactured by Big Chemie Japan Co., Ltd.) KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-640, KF-642, KF-643, KF-6020, X-22-4515 , KF-6011, KF-6012, KF-6015, KF-6017 (trade names, manufactured by Shin-Etsu Chemical Co., Ltd.), and the like.

1.2.5. Water The water-based ink composition used in the ink jet recording method according to this embodiment contains water. Water is a main medium of the water-based ink composition, and is a component that is evaporated and scattered in the above-described drying step.

  The water is preferably water from which ionic impurities such as pure water such as ion exchange water, ultrafiltration water, reverse osmosis water, distilled water or ultrapure water are removed as much as possible. In addition, when water sterilized by ultraviolet irradiation or addition of hydrogen peroxide is used, it is preferable because the generation of mold and bacteria can be prevented when the pigment dispersion and the aqueous ink composition using the same are stored for a long period of time. is there.

1.2.6. Other Ingredients The aqueous ink composition used in the ink jet recording method according to the present embodiment can further contain a pH adjuster, an antiseptic / antifungal agent, a rust inhibitor, chelation, and the like.
Examples of the pH adjuster include potassium dihydrogen phosphate, disodium hydrogen phosphate, sodium hydroxide, lithium hydroxide, potassium hydroxide, ammonia, diethanolamine, triethanolamine, triisopropanolamine, potassium carbonate, sodium carbonate, Examples thereof include sodium hydrogen carbonate.

  Examples of antiseptics and fungicides include sodium benzoate, sodium pentachlorophenol, 2-pyridinethiol-1-oxide sodium, sodium sorbate, sodium dehydroacetate, 1,2-dibenzisothiazoline-3-one Etc. Examples of commercially available products include Proxel XL2, Proxel GXL (above trade name, manufactured by Avicia), Denside CSA, NS-500W (above trade name, manufactured by Nagase ChemteX Corporation), and the like.

Examples of the rust inhibitor include benzotriazole.
Examples of the chelating agent include ethylenediaminetetraacetic acid and salts thereof (such as ethylenediaminetetraacetic acid dihydrogen disodium salt).

1.2.7. Physical Properties The viscosity at 20 ° C. of the aqueous ink composition used in the ink jet recording method according to this embodiment is preferably 2 mPa · s or more and 10 mPa · s or less, more preferably 3 mPa · s or more and 8 mPa · s or less. When the viscosity of the water-based ink composition at 20 ° C. is within the above range, an appropriate amount of droplets of the water-based ink composition is ejected from the nozzle, and the flying curve and scattering of the droplets can be further reduced. Can be suitably used. The viscosity of the water-based ink composition can be measured by maintaining the temperature of the water-based ink composition at 20 ° C. using a vibration viscometer VM-100AL (manufactured by Yamaichi Electronics Co., Ltd.).

2. Examples Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to these examples.

2.1. Preparation of aqueous ink composition 2.1.1 Preparation of pigment dispersion The aqueous ink composition used in this example used a water-insoluble pigment as a colorant. When adding the pigment to the water-based ink composition, the pigment was dispersed in advance with a water-soluble resin.
The pigment dispersion was prepared as follows. First, 84.4 parts by mass of ion-exchanged water in which 0.6 parts by mass of a 30% aqueous ammonia solution (neutralizing agent) was dissolved, 3.0 parts by mass of a styrene-acrylic acid copolymer (weight average) as a water-soluble resin. Molecular weight: 25,000, acid value: 180) was added and dissolved. Thereto, 12 parts by mass of the following pigment was added, and dispersion treatment was performed for 10 hours with zirconia beads. Thereafter, centrifugal filtration using a centrifugal separator was performed to remove impurities such as coarse particles and dust, and the pigment concentration was adjusted to 12% by mass. Below, the pigment kind used for manufacture of a pigment dispersion liquid is shown.
C. I. Pigment Black 7 (used for black pigment dispersion)
C. I. Pigment Yellow 74 (used for yellow pigment dispersion)
C. I. Pigment Red 122 (used for magenta pigment dispersion)
C. I. Pigment Blue 15: 3 (used for cyan pigment dispersion)

2.1.2. Preparation of Aqueous Ink Composition and Ink Set Using the pigment dispersion prepared in “2.1.1 Preparation of Pigment Dispersion” above, the material compositions shown in Table 1 were used for black, yellow, magenta, and cyan. Four color aqueous ink compositions were prepared to form one ink set, and ink sets of aqueous ink composition 1 to aqueous ink composition 11 having different compositions were obtained. Each water-based ink composition is prepared by placing the pigment dispersion and the materials shown in Table 1 in a container, stirring and mixing with a magnetic stirrer for 1 hour, and filtering with a membrane filter having a pore size of 5 μm to obtain coarse particles, dust, etc. It was prepared by removing impurities. The numerical values in Table 1 all indicate mass%, and ion-exchanged water was prepared so that the total amount of each water-based ink composition was 100 mass%.

  In Table 1, as the surfactant, a silicon-based surfactant “BYK-348” (manufactured by Big Chemie Japan Co., Ltd.) was used. Further, urethane-acrylic resin particles AU-304 (manufactured by Daicel Chemical Industries) and acrylic resin particles AST-499 (manufactured by Daicel Chemical Industries) were used as the thermoplastic resin particles.

2.2. Evaluation test 2.2.1. Evaluation of quick-drying (1) Creation of recorded matter A part of the inkjet printer PX-G930 (manufactured by Seiko Epson Corporation) is remodeled, and a heater capable of changing the temperature is attached to the paper guide unit, and a recording medium is recorded during image recording. The heating can be adjusted.
2.1.2. Inkjet printers were filled with the ink sets of water-based ink composition 1 to water-based ink composition 11 prepared in Step 1, respectively, and a polyethylene terephthalate film (trade name “Lumirror S10, 50 micron thickness”, manufactured by Toray Industries, Inc. A solid pattern is recorded by adjusting the heater of the paper guide section so that the recording medium is 50 ° C. during recording, and immediately after recording, the recording medium is placed in a constant temperature bath at 60 ° C. The recording material for evaluation was produced by leaving still for 10 minutes. The solid pattern image was formed by overlapping four colors equally so as to obtain a printing ink amount of 1.0 mg / cm ² at a resolution of 720 dpi vertical and 720 dpi horizontal.

(2) Evaluation of recorded matter The quick-drying property of the recorded matter was judged according to the following evaluation criteria by touching the recorded portion with a finger immediately after drying and after taking out the recorded matter from the thermostat and returning to room temperature. did. Table 1 shows the evaluation results as quick-drying properties.
○: No ink adheres to the finger.
Δ: Stickiness on the surface of the recorded matter remains, but no ink adheres to the finger, and stickiness is acceptable in actual use.
X: Ink adheres to the finger.

2.2.2. Evaluation of abrasion resistance (1) Preparation of recorded material 2.1.2. The ink sets of the water-based ink composition 1 to the water-based ink composition 11 prepared in 1 were filled in the ink jet printer used in 2.3.1, PET film was used as a recording medium, and the paper guide heater was adjusted. A solid pattern was recorded such that the recording medium was 50 ° C. during recording, and immediately after recording, the recording medium was left in a constant temperature bath at 60 ° C. for 10 minutes to produce a recorded material for evaluation. The solid pattern image was formed by overlapping four colors equally so that the printing ink amount was 1.6 mg / cm ² at a resolution of 720 dpi vertically and 720 dpi horizontally.

(2) Evaluation of recorded matter After the obtained recorded matter was kept at 20 ° C. for 16 hours, a load of 500 g and a number of frictions of 10 times were used using a Gakushin type friction fastness tester AB-301 (manufactured by Tester Sangyo Co., Ltd.). Under the above conditions, the friction piece attached with the white cotton cloth for friction and the recorded material were rubbed together, and the surface state of the image was visually observed and judged according to the following evaluation criteria. Table 1 shows the evaluation results as abrasion resistance.
○: No scratch even after rubbing 10 times.
Δ: Rub 10 times after rubbing on the surface, but there is no scratch that exposes the substrate, and the rubbing is acceptable in actual use.
X: There is a scratch that the base is exposed by rubbing 10 times.

2.2.3. Evaluation of printing stability 2.1.2. The ink sets of water-based ink composition 1 to water-based ink composition 11 prepared in 1 were filled in the ink jet printer used in 2.3.1, and the ink jet printer was allowed to stand at room temperature for 24 hours. During this time, the nozzle surface of the head of the ink jet printer was covered with a cap provided in the ink jet printer. After 24 hours, printing was performed with the ink jet printer.

The obtained recorded matter was observed and examined for the presence or absence of dot omission and dot bending. When there was dot omission or dot bending, an ink jet printer cleaning operation was performed. The evaluation is based on the following evaluation criteria, and the evaluation results are shown in Table 1 as printing stability.
○: Neither missing dots nor bent dots are recognized in printing immediately after being left.
[Delta]: Occurrence of missing dots or bent dots is recognized in printing immediately after being left, but missing dots and bent dots are not recognized by the cleaning operation.
X: Missing dots or bent dots are recognized even when there is a cleaning operation.

  Using the water-based ink composition 1 to the water-based ink composition 7 described in Example 1 to Example 7 of Table 1, using a PET film as a recording medium, the temperature of the first step is 50 ° C., and the second The recorded material produced at a process temperature of 60 ° C. has good quick drying properties from the results of quick drying evaluation or quick drying properties that are not problematic in actual use, and the recorded images on the PET film from the evaluation results of abrasion resistance. It was shown that the surface was hardly scratched and was excellent in abrasion resistance. In addition, the ink jet printer filled with the water-based ink composition 1 to the water-based ink composition 6 described in Examples 1 to 6 in Table 1 can perform normal printing at least by a cleaning operation from the evaluation result of the printing stability. It was confirmed that.

  When the water-based ink composition 8 described in Comparative Example 1 in Table 1 is used, the content of the thermoplastic resin particles containing the urethane resin in the water-based ink composition is less than 1% by mass, so An inferior recording was formed. Further, since the content of the nitrogen-containing organic solvent in the water-based ink composition exceeds 15% by mass, a recorded matter having an excellent quick drying property was formed.

  When the water-based ink composition 9 described in Comparative Example 2 in Table 1 is used, since the content of the nitrogen-containing organic solvent in the water-based ink composition is less than 3% by mass, the recorded material is not excellent in abrasion resistance. Formed.

  When the water-based ink composition 10 described in Comparative Example 3 in Table 1 is used, the content of the thermoplastic resin particles containing a urethane resin in the water-based ink composition exceeds 8% by mass, so that the printing stability The result was not excellent.

  When the water-based ink composition 11 described in Comparative Example 4 in Table 1 was used, the thermoplastic resin particles in the water-based ink composition did not contain a urethane resin, and thus a recorded material having excellent abrasion resistance was formed.

2.2.4. Heating temperature evaluation 2.1.2. Using the ink sets of the water-based ink composition 1 to the water-based ink composition 3 prepared in step 1, the temperature adjustment of the heater of the paper guide section is set to 60 ° C, the drying temperature immediately after recording is set to 90 ° C, and the drying time immediately after recording is set to Except for 1 minute, the drying property was evaluated in the same manner as 2.2.1, and the abrasion resistance was evaluated in the same manner as 2.2.2. The evaluation results are shown in Table 2 as the quick drying properties and abrasion resistance of Examples 8 to 10.

  2.1.2. A non-absorbent recording medium using the ink set of the water-based ink composition 1 to the water-based ink composition 3 prepared in step 1 and a polyvinyl chloride film (trade name “LLSP EX113”, manufactured by Sakurai Co., Ltd., hereinafter “PVC film” 2), the temperature adjustment of the heater of the paper guide unit was changed to 40 ° C., the drying temperature immediately after recording was changed to 35 ° C., 40 ° C., and 50 ° C., respectively, and the drying time immediately after recording was changed to 1 minute. The dryness was evaluated in the same manner as in 2.1 and the abrasion resistance was evaluated in the same manner as in 2.2.2. The evaluation results are shown in Table 3 as quick-drying properties and abrasion resistance of Examples 11 to 16 and Comparative Examples 5 to 7.

  Using the water-based ink composition 1 to the water-based ink composition 3 described in Example 8 to Example 10 in Table 2, the temperature adjustment of the heater of the paper guide section is set to 60 ° C., and the drying temperature immediately after recording is set to 90 ° C. The recorded material produced with a drying time of 1 minute immediately after recording has good quick-drying properties based on the results of quick-drying evaluation, and on the surface of the image recorded on the PET film based on the evaluation results of abrasion resistance. It was shown that it was difficult to scratch and was excellent in abrasion resistance.

  Using the water-based ink composition 1 to the water-based ink composition 3 described in Example 11 to Example 16 in Table 3, the temperature adjustment of the heater of the paper guide unit is 40 ° C. with respect to the PVC film as the recording medium. The recorded matter produced by setting the drying temperature immediately after recording to 40 ° C. and 50 ° C. and the drying time immediately after recording to 1 minute has good quick-drying properties or quick-drying properties that do not cause any problem in practical use, Further, the evaluation result of the abrasion resistance showed that the surface of the image recorded on the PVC film was hardly scratched and was excellent in abrasion resistance.

  Using the water-based ink composition 1 to water-based ink composition 3 described in Comparative Example 5 to Comparative Example 7 in Table 3, with respect to the PVC film as the recording medium, the temperature adjustment of the heater of the paper guide section to 40 ° C., A recorded material prepared with a drying temperature immediately after recording of 35 ° C. and a drying time immediately after recording of 1 minute is not excellent in quick drying from the evaluation result of quick drying, and is recorded on the PVC film from the evaluation result of abrasion resistance. It was shown that the image was not excellent in abrasion resistance.

  The present invention is not limited to the embodiments described above, and various modifications are possible. For example, the present invention includes substantially the same configuration (for example, a configuration having the same function, method, and result, or a configuration having the same purpose and effect) as the configuration described in the embodiment. In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. In addition, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

Claims (6)

A first step of heating a non-ink-absorbing or low-absorbing recording medium to a temperature range of 40 ° C. or more and 60 ° C. or less by an inkjet recording apparatus and discharging droplets of the aqueous ink composition;
A second step of heating the recording medium to a temperature range of 40 ° C. or higher and 90 ° C. or lower and drying the water-based ink composition discharged on the recording medium;
An inkjet recording method comprising:
The water-based ink composition includes water, at least one water-insoluble colorant, a low surface tension solvent, a surfactant,
A nitrogen-containing solvent consisting of at least one selected from 2-pyrrolidone and N, N′-dimethylpropyleneurea;
Water-insoluble thermoplastic resin particles containing at least a urethane resin, and
The content of the nitrogen-containing solvent consisting of at least one selected from 2-pyrrolidone and N, N′-dimethylpropyleneurea in the aqueous ink composition is 3 to 15% by mass,
An ink jet recording method wherein the content of water-insoluble thermoplastic resin particles containing at least a urethane resin in the water-based ink composition is 1 to 8% by mass. The inkjet recording method according to claim 1,
An ink jet recording method, wherein the water-insoluble thermoplastic resin particles are resin particles comprising a urethane resin and an acrylic resin. The inkjet recording method according to claim 1 or 2,
The ink jet recording method, wherein the water-insoluble colorant is a pigment and is dispersed in a water-based ink composition with a water-soluble resin. The inkjet recording method according to any one of claims 1 to 3,
An ink jet recording method, wherein the surfactant is a silicon-based surfactant. In the ink jet recording method according to any one of claims 1 to 4,
An ink jet recording method wherein the low surface tension solvent is 1,2-hexanediol. In the ink jet recording method according to any one of claims 1 to 5,
The recording medium is heated by a heater or hot air.