JP7466835B2 - Recording method and recording device - Google Patents

Description

The present invention relates to a recording method and a recording device.

Inkjet recording methods are capable of recording high-definition images using relatively simple equipment, and have been rapidly developed in various fields. In particular, various methods for recording on various media other than smooth recording media such as paper have been studied. One such recording medium is, for example, fleece paper having a decorative layer on its surface (see, for example, Patent Document 1).
Patent Document 1 discloses a method for forming a three-dimensional pattern on the surface of fleece paper.

JP 2016-69854 A

It is not easy to apply water-based ink to a synthetic fiber-containing sheet with a three-dimensional pattern to obtain excellent image quality, and it is difficult to apply ink evenly to a recording medium with such an uneven surface.

The present invention is a recording method for recording on a recording medium, the recording medium being a synthetic fiber-containing sheet having a three-dimensional pattern on its surface, and the recording method includes an ink attachment step of ejecting an aqueous ink composition from an inkjet head and attaching it to the recording medium, the aqueous ink composition containing a pigment, water, and an organic solvent, the pigment content being 5.0% by mass or less relative to the total amount of the aqueous ink composition, the organic solvent containing at least one of glycol ethers or alkanediols having 5 or more carbon atoms, and the total content of the glycol ethers or alkanediols being 1.0% by mass or more relative to the total amount of the aqueous ink composition.

The present invention also relates to a recording device for recording by a recording method, the recording device being equipped with an inkjet head for ejecting an aqueous ink composition onto a recording medium including a synthetic fiber-containing sheet having a three-dimensional pattern on its surface, the aqueous ink composition containing a pigment, water, and an organic solvent, the pigment content being 5.0% by mass or less relative to the total amount of the aqueous ink composition, the organic solvent containing at least one of glycol ethers or alkanediols having 5 or more carbon atoms, and the total content of the glycol ethers or alkanediols being 1.0% by mass or more relative to the total amount of the aqueous ink composition.

FIG. 1 is a perspective view illustrating an example of an inkjet recording apparatus according to an embodiment of the present invention.

Below, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail with reference to the drawings as necessary, but the present invention is not limited to this, and various modifications are possible without departing from the gist of the invention. In the drawings, the same elements are given the same reference numerals, and duplicated explanations will be omitted. Furthermore, unless otherwise specified, the positional relationships such as up, down, left, and right will be based on the positional relationships shown in the drawings. Furthermore, the dimensional ratios of the drawings are not limited to those shown in the drawings.

1. Recording method The recording method of the present embodiment is a recording method using a synthetic fiber-containing sheet having a three-dimensional pattern on the surface as a recording medium, and includes an ink attachment step of ejecting an aqueous ink composition from an inkjet head and attaching it to the recording medium. In the recording method of the present embodiment, the ink attachment step uses an aqueous ink composition that contains a pigment, water, and an organic solvent, the pigment content is 5.0 mass% or less with respect to the total amount of the aqueous ink composition, the organic solvent includes at least one of glycol ethers and alkanediols having 5 or more carbon atoms (hereinafter, these are also collectively referred to as "specific organic solvent"), and the total content of the specific organic solvent is 1.0 mass% or more with respect to the total amount of the aqueous ink composition.

Recording methods using the inkjet method are used for a wide variety of recording media. Among them, the use of wallpaper as a recording medium and performing arbitrary recording using the inkjet method has been considered. For example, fleece wallpaper can be attached to a wall with a water-based adhesive, and generally does not swell or wrinkle when exposed to water, making it suitable for recording with a water-based ink composition. Such wallpaper is not limited to those with a smooth recording surface like ordinary paper, and from the standpoint of design, those with a textured surface such as embossing are preferably used.

However, when an ink composition is applied to a recording medium having such a three-dimensional pattern, the ink composition tends to concentrate in the recesses, and the concentrated areas (hereinafter also referred to as "ink puddles") are darkly colored, which makes it difficult to perform the intended recording. The reason for this is not particularly limited, but it is thought that the ink composition that has been applied to the three-dimensional pattern flows along the surface of the three-dimensional pattern due to gravity before penetrating the recording medium or drying. In addition, when the ink composition dries in this locally concentrated and pooled state, the ink composition in that area is prone to peeling off, which also causes the problem of worsening the wet friction resistance of the recorded material.

In addition, fleece used for wallpaper and the like is generally composed of a sheet containing synthetic fibers. Therefore, compared to Japanese paper and the like that contains natural fibers, fleece wallpaper is inferior in absorbing water-based ink compositions, and is more susceptible to problems related to the concentration of the ink composition as described above.

In contrast, in this embodiment, the permeability of the water-based ink composition into the synthetic fiber-containing sheet is improved by adjusting the pigment content and the specific organic solvent content. This allows the water-based ink composition to uniformly permeate uneven parts of wallpaper, etc., and while suppressing ink accumulation in recesses, it is possible to form better solid image quality on the synthetic fiber-containing sheet having a three-dimensional pattern on the surface. In addition, since ink accumulation can be suppressed, the wet friction resistance of the recorded material can be further improved. Therefore, in this embodiment, it is preferable to apply the ink composition to at least the part of the recording medium having a three-dimensional pattern. Each component will be described in detail below.

Before describing each step, the recording medium that is the subject of the recording method of the present embodiment will be described. The recording method of the present embodiment is directed to a recording medium that includes a synthetic fiber-containing sheet having a three-dimensional pattern on its surface.

Here, the synthetic fiber-containing sheet is not particularly limited as long as it contains synthetic fibers, and may be a sheet composed only of synthetic fibers or a sheet containing synthetic fibers and natural fibers. Among these, a sheet containing synthetic fibers and natural fibers, that is, a sheet in which natural fibers and synthetic fibers are mixed, is preferred. By including synthetic fibers, the durability as a recording medium is further improved, and the sheet is less likely to swell even when it absorbs water. On the other hand, the ink absorbency is reduced by including synthetic fibers, and therefore the present invention is useful. Furthermore, by using a sheet in which natural fibers and synthetic fibers are mixed, it is easy to impart a three-dimensional pattern, and the ink absorbency can be improved while maintaining the above-mentioned durability, etc.

Synthetic fibers are not particularly limited, but examples include polyester fibers such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, and copolymer polyester; polyolefin fibers such as linear low-density polyethylene, low-density polyethylene, high-density polyethylene, and polypropylene; polyamide fibers such as nylon 6, nylon 66, nylon 610, and nylon 46; acrylic fibers such as polyacrylonitrile; polyurethane fibers, and semi-synthetic fibers such as acetate, triacetate, and promix. Of these, polyester fibers are preferred.

The natural fibers are not particularly limited, but examples include wood pulp fibers, non-wood pulp fibers, cellulosic fibers such as cotton and hemp, wool, silk, etc. Among these, cellulosic fibers are preferred.

The synthetic fiber-containing sheet is not particularly limited as long as it is made by forming fibers into a sheet, and may be a woven fabric, a nonwoven fabric, or a textile. Among these, nonwoven fabric is preferred. In this embodiment, nonwoven fabric made of a mixture of natural and synthetic fibers used for wallpaper is also called fleece wallpaper.

Furthermore, the recording medium in this embodiment is not particularly limited as long as it includes a synthetic fiber-containing sheet having a three-dimensional pattern on its surface, and may be a synthetic fiber-containing sheet alone, or may be a laminate having a synthetic fiber-containing sheet on the recording surface side and another layer on its back surface. Here, examples of the other layer include a support layer that imparts strength to the synthetic fiber-containing sheet, and when used as wallpaper, an adhesive layer and a release layer that protects the adhesive surface of the adhesive layer. Also, the recording medium in this embodiment may have a surface partly constituted by the synthetic fiber-containing sheet.

The three-dimensional pattern of the synthetic fiber-containing sheet is not particularly limited, but examples include a pattern in which an uneven surface can be seen with the naked eye. The three-dimensional pattern can be any pattern consisting of a predetermined repeating unit such as stripes, grids, or designs, or an irregular pattern. In addition, the synthetic fiber-containing sheet does not need to have a pattern on its entire surface, and a pattern applied to a predetermined location on the sheet for the purpose of marking or marking is also included in the three-dimensional pattern of this embodiment.

Such a three-dimensional pattern can be imparted to the sheet surface by, for example, embossing, without any particular limitation. In addition, the three-dimensional pattern may be formed by a method other than pressure pressing, such as partially attaching minute resins to the sheet surface to form a three-dimensional pattern with the resin, or forming a three-dimensional pattern repeatedly on the surface during papermaking.

By using such a recording medium, swelling is less likely to occur, and the wet friction resistance of the resulting recorded matter tends to be improved. In addition, when the resulting recorded matter is coated with a water-based adhesive and attached to an object to be adhered, it also shows good adhesion.

The basis weight of the synthetic fiber-containing sheet is preferably 100 g/ ^m2 or more. On the other hand, it is preferably 300 g/ ^m2 or less. It is more preferably 120 to 300 g/ ^m2 , even more preferably 120 to 250 g/ ^m2 , and particularly preferably 150 to 230 g/ ^m2 . When the basis weight of the synthetic fiber-containing sheet is 100 g/ ^m2 or more, the absorbency of the water-based ink composition is further improved, and ink pooling tends to be further improved.

1.2. Ink Adhesion Process The ink adhesion process is a process of ejecting the water-based ink composition from an inkjet head and adhering it to at least a three-dimensional pattern on a recording medium. Here, the inkjet head is a head that ejects the water-based ink composition toward a recording medium to perform recording, and the head has a cavity that ejects the stored ink composition from a nozzle, an ejection drive unit that imparts an ejection driving force to the water-based ink composition, and a nozzle that ejects the water-based ink composition outside the head. The ejection drive unit can be formed using an electromechanical conversion element such as a piezoelectric element that changes the volume of the cavity by mechanical deformation, or an electrothermal conversion element that generates heat to generate bubbles in the ink and eject it.

The inkjet head may be either a serial head or a line head. In the serial method using a serial head, the head is moved in a main scanning direction (S1-S2) intersecting with the sub-scanning direction (T1-T2) of the recording medium while ejecting the water-based ink composition and performing main scanning multiple times to deposit the ink on the recording medium, and an image is recorded on the recording medium by performing main scanning two or more times on the same area (see Figure 1). In the line method using a line head, the head is fixed and the recording medium is moved along the scanning direction (the vertical direction of the recording medium, the transport direction), and ink droplets are ejected from the nozzle openings of the head in conjunction with this movement, thereby recording an image on the recording medium.

Among these, it is preferable to use a serial method using a serial head for the recording method of this embodiment. This tends to improve the solid image quality of the resulting recorded matter.

In the ink adhesion step, the maximum adhesion amount of the water-based ink composition is preferably 20 mg/ ^inch2 or less. On the other hand, it is preferably 2 mg/ ^inch2 or more. Furthermore, it is more preferably 5 to 18 mg/ ^inch2 , and even more preferably 10 to 14 mg/ ^inch2 . When the maximum adhesion amount of the water-based ink composition is 20 mg/ ^inch2 or less, ink pooling is more suppressed and wet friction resistance tends to be more improved. Furthermore, when the maximum adhesion amount of the water-based ink composition is 2 mg/inch2 or ^more , the optical density and filling property of the obtained recorded matter tend to be more improved. Note that the "maximum adhesion amount" refers to the adhesion amount of the area with the largest adhesion amount per unit area of ink when there are areas with different adhesion amounts depending on the recording area in the recording method. Here, the area may be an area in which the adhesion amount can be specified, for example, an area of about 1 x 1 mm.

1.2.1. Water-based ink composition The water-based ink composition of this embodiment contains a pigment, water, and an organic solvent, and may contain a resin, a wax, an antifoaming agent, and a surfactant as necessary. In particular, the water-based ink composition of this embodiment contains a specific organic solvent that is at least one of glycol ethers and alkanediols having 5 or more carbon atoms as an organic solvent, and may contain an organic solvent other than the specific organic solvent (hereinafter also referred to as "other organic solvents") as necessary. When there is no need to distinguish between the specific organic solvent and the other organic solvent, it is simply referred to as "organic solvent". In addition, in this embodiment, "water-based" refers to a composition in which water is one of the main solvent components. Each component will be described in detail below.

1.2.1.1. Pigments Pigments are not particularly limited, but examples thereof include inorganic pigments such as furnace black, lamp black, acetylene black, channel black, and other carbon blacks (C.I. Pigment Black 7), iron oxide, and titanium oxide; and organic pigments such as quinacridone pigments, quinacridonequinone pigments, dioxazine pigments, phthalocyanine pigments, anthrapyrimidine pigments, anthanthrone pigments, indanthrone pigments, flavanthrone pigments, perylene pigments, diketopyrrolopyrrole pigments, perinone pigments, quinophthalone pigments, anthraquinone pigments, thioindigo pigments, benzimidazolone pigments, isoindolinone pigments, azomethine pigments, magenta pigments, and azo pigments. The pigments may be used alone or in combination of two or more.

The pigment content is 5.0% by mass or less, preferably 1.0 to 5.0% by mass, and more preferably 2.5 to 5.0% by mass, relative to the total amount of the water-based ink composition. By making the pigment content 5.0% by mass or less, ink accumulation is further suppressed and wet friction resistance is further improved. Furthermore, by making the pigment content 1.0% by mass or more, the optical density of the resulting recorded matter tends to be further improved. Note that the pigment content refers to the solid content, and when the pigment is mixed into the water-based ink composition in the form of a pigment dispersion, it refers to the solid content of that liquid.

1.2.1.2. Water The water content is preferably 40% by mass or more, and more preferably 45 to 98% by mass, based on the total amount of the water-based ink composition. Furthermore, it is preferably 55 to 85% by mass, more preferably 60 to 80% by mass, and even more preferably 65 to 75% by mass. By keeping the water content within the above range, swelling of the recording medium is not caused, and a recorded matter having excellent wet friction resistance can be obtained.

1.2.1.3. Organic solvent The water-based ink composition of this embodiment contains, as the specific organic solvent, an alkyl ether (glycol ether) of a polyhydric alcohol and an alkanediol having 5 or more carbon atoms. By containing a predetermined amount of such a specific organic solvent, the permeability of the water-based ink composition into a synthetic fiber-containing sheet can be further improved. Therefore, even when the water-based ink composition is applied to a three-dimensional pattern, the water-based ink composition quickly permeates into the applied area, and the occurrence of ink pooling can be suppressed, and the solid image quality of the obtained recorded matter is further improved, as well as the wet friction resistance of the obtained recorded matter is further improved.

Glycol ethers are etherified alkylene glycols or condensates formed by intermolecular condensation of hydroxyl groups of alkylene glycols. In the case of condensates, the number of condensations is preferably 2 to 6, more preferably 2 to 4. In alkylene glycols and their condensates, the alkylene group preferably has 1 to 5 carbon atoms, more preferably 2 to 4 carbon atoms. The ether of the glycol ether is preferably an alkyl ether. The number of carbon atoms in the alkyl group of the alkyl ether is preferably 1 to 5, more preferably 2 to 4. The glycol ether may be a glycol monoether or glycol diether, with glycol monoether being preferred.

Glycol ethers are not particularly limited, but examples thereof include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol mono-t-butyl ether, triethylene glycol monobutyl ether, 1-methyl-1-methoxybutanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, Examples of glycol monoethers include glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, and tetraethylene glycol monobutyl ether; and glycol diethers include glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol ethyl methyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, and tripropylene glycol dimethyl ether. The glycol ethers may be used alone or in combination of two or more.

Among these, glycol monoethers are preferred, and glycol monoethers having an ether group with 3 to 5 terminal carbon atoms are preferred, with triethylene glycol monobutyl ether and tetraethylene glycol monobutyl ether being more preferred. By using such glycol ethers, ink accumulation is further suppressed and wet friction resistance tends to be further improved.

The alkanediols having 5 or more carbon atoms are not particularly limited, but examples thereof include 1,2-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,2-heptanediol, 2-ethyl-1,3-hexanediol, 2,2-dimethyl-1,3-propanediol, 2,2-dimethyl-1,3-hexanediol, and 3-methyl-1,5-pentanediol. The alkanediols having 5 or more carbon atoms may be used alone or in combination of two or more.

Among these, alkanediols having 5 to 8 carbon atoms are preferred, and alkanediols having 5 to 8 carbon atoms and a hydroxyl group at the long chain end are more preferred. In particular, 1,2-alkanediols are preferred. For example, 1,2-hexanediol and 3-methyl-1,5-pentanediol are particularly preferred.

The use of such alkanediols tends to further suppress ink accumulation and improve wet friction resistance.

The specific organic solvents may be used alone or in combination of two or more.

The total content of the specific organic solvents is 1.0% by mass or more relative to the total amount of the water-based ink composition. It is preferably 1.0 to 20% by mass, more preferably 1.0 to 15% by mass, more preferably 1.0 to 8.0% by mass, and even more preferably 1.5 to 4.0% by mass. By having the content of the specific organic solvents be 1.0% by mass or more, ink pooling is suppressed and wet friction resistance is further improved. In addition, by having the content of the specific organic solvents be equal to or less than the above range, the drying property of the water-based ink composition is further improved, which tends to further improve wet friction resistance.

The total content of the specific organic solvents is preferably 2.0 to 35% by mass, more preferably 3.0 to 30% by mass, and even more preferably 5.0 to 20% by mass, relative to the total amount of all organic solvents. When the content of the specific organic solvents is 2.0% by mass or more relative to the total amount of all organic solvents, ink pooling is further suppressed and wet friction resistance is further improved. When the content of the specific organic solvents is 35% by mass or less relative to the total amount of all organic solvents, the drying properties of the water-based ink composition are further improved, which tends to further improve wet friction resistance.

1.2.1.4. Other organic solvents The aqueous ink composition of this embodiment may contain other organic solvents. Examples of other organic solvents include, but are not limited to, nitrogen-containing solvents such as 2-pyrrolidone, N-methyl-2-pyrrolidone, and N-ethyl-2-pyrrolidone; polyols such as glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,2-butanediol, and 1,4-butanediol; and alcohols such as methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butanol, 2-butanol, tert-butanol, iso-butanol, n-pentanol, 2-pentanol, 3-pentanol, and tert-pentanol.

Examples of the nitrogen-containing solvent include cyclic amides and non-cyclic amides. Examples of the cyclic amides include the above-mentioned pyrrolidones. Examples of the non-cyclic amides include, for example, N,N-dialkyl-alkylamides. Examples of the N,N-dialkyl-alkylamides include, for example, N,N-dialkyl-alkoxyalkylamides.
Examples of the polyols include alkane polyols having 4 or less carbon atoms, and condensates in which hydroxyl groups of alkane polyols having 4 or less carbon atoms are condensed together intermolecularly. The number of hydroxyl groups in the molecule of the polyol is preferably 2 to 4, and more preferably 2.
Among these, polyols, nitrogen-containing solvents, etc. are preferred. For example, propylene glycol, 2-pyrrolidone, etc. The other organic solvents may be used alone or in combination of two or more.

The content of the other organic solvent is preferably 1% by mass or more, and more preferably 2 to 45% by mass, based on the total amount of the water-based ink composition. Furthermore, it is preferably 10 to 40% by mass, more preferably 15 to 35% by mass, and even more preferably 20 to 30% by mass. By keeping the content of the other organic solvent within the above range, ink accumulation is further suppressed and wet friction resistance tends to be further improved.

The total content of organic solvents, including the specific organic solvent and other organic solvents, is preferably 1 to 50% by mass, more preferably 10 to 45% by mass, even more preferably 15 to 40% by mass, and even more preferably 20 to 35% by mass, relative to the total amount of the water-based ink composition. By having the total content of organic solvents within the above range, ink accumulation is further suppressed and wet friction resistance tends to be further improved.

The normal boiling point of the organic solvent contained in the water-based ink composition of this embodiment is preferably 160 to 280°C, more preferably 160 to 270°C, and even more preferably 160 to 250°C. It is even more preferably 170 to 220°C. By having the normal boiling point of the organic solvent within the above range, ink accumulation tends to be further suppressed and wet friction resistance tends to be further improved. It is more preferable that the normal boiling point of the above specific organic solvent is within the above range.

The content of the organic solvent having a normal boiling point within the above range is preferably 95 to 100% by mass, more preferably 98 to 100% by mass, and even more preferably 99 to 100% by mass, relative to the total amount of the water-based ink composition. By having the content of such an organic solvent within the above range, ink accumulation is further suppressed and wet friction resistance tends to be further improved.

Furthermore, the content of organic solvents having normal boiling points outside the above range is preferably 5.0% by mass or less, more preferably 2.0% by mass or less, even more preferably 1.0% by mass or less, still more preferably 0.5% by mass or less, and particularly preferably 0.1% by mass or less, and the lower limit of the content may be 0% by mass. By having the content of such organic solvents within the above range, ink pooling is further suppressed, and wet friction resistance tends to be further improved.
The water-based ink composition preferably does not contain more than 1 mass of an organic solvent having a normal boiling point of more than 280° C., more preferably does not contain more than 0.5 mass, and even more preferably does not contain more than 0.1 mass. When it says that it does not contain more than XX mass, it means that it may be contained or does not need to be contained as long as it does not exceed XX mass. In this case, it is preferable that the wet friction resistance, the suppression of ink puddling, the image quality, etc. are more excellent.

1.2.1.5. Resin Examples of the resin include those dissolved in the aqueous ink composition, and those dispersed in the form of an emulsion (resin particles). In particular, from the viewpoint of clogging recovery, those dispersed in the form of an emulsion are more preferable. By using such a resin, there is a tendency for a recorded matter to be obtained that has better wet friction resistance. In particular, there is a tendency for it to contribute to improving the binding between the recording medium and the ink coating (wet friction resistance).

Examples of such resins include, but are not limited to, acrylic resins, vinyl acetate resins, vinyl chloride resins, butadiene resins, styrene resins, polyester resins, cross-linked acrylic resins, cross-linked styrene resins, benzoguanamine resins, phenolic resins, silicone resins, epoxy resins, urethane resins, paraffin resins, fluorine resins, and water-soluble resins, as well as copolymers of monomers constituting these resins. Examples of copolymers include, but are not limited to, styrene-butadiene resins and styrene-acrylic resins. In addition, as the resin, polymer latexes containing these resins can be used. Examples include polymer latexes containing fine particles of acrylic resins, styrene-acrylic resins, styrene resins, cross-linked acrylic resins, and cross-linked styrene resins. The resins may be used alone or in combination of two or more types. In particular, it is preferable that the resin particles contained in the water-based ink composition of this embodiment contain at least one of acrylic resins, urethane resins, and polyester resins.
The acrylic resin is a polymer obtained by polymerizing at least an acrylic monomer, and also includes a copolymer of an acrylic monomer and another monomer. Examples of the acrylic monomer include (meth)acrylate and (meth)acrylic acid. Examples of the other monomer include vinyl monomers, such as styrene.
The urethane-based resin is a resin obtained by urethane polymerization of a polyisocyanate compound and a polyol compound.

The resin content is preferably 0.5% by mass or more, more preferably 1.0 to 20% by mass, even more preferably 1.0 to 10% by mass, even more preferably 2.0 to 8.0% by mass, and even more preferably 2.0 to 6.0% by mass, relative to the total amount of the water-based ink composition. When the resin content is in the above range or more, wet friction resistance tends to be further improved, as described above. In addition, when the resin content is in the above range or less, ejection stability and clogging recovery tend to be further improved.

1.2.1.6. Wax Examples of waxes include those that dissolve in the aqueous ink composition, or those that disperse in the form of an emulsion. The use of such waxes tends to produce recorded matter with better wet friction resistance. In particular, the wax tends to contribute to improving wet friction resistance by being unevenly distributed on the surface of the ink coating on the recording medium (the interface between the air and the ink coating). Examples of such waxes include, but are not limited to, ester waxes of higher fatty acids and higher monohydric alcohols or dihydric alcohols (preferably monohydric alcohols), paraffin waxes, olefin waxes, or mixtures thereof.

The wax content is preferably 0.1 to 3.0% by mass, more preferably 0.3 to 2.0% by mass, and even more preferably 0.3 to 1.0% by mass, relative to the total amount of the water-based ink composition. As described above, a wax content of 0.1% by mass or more tends to further improve wet friction resistance. Furthermore, a wax content of 3.0% by mass or less tends to further improve ejection stability and clogging recovery.

1.2.1.7. Defoaming Agent The defoaming agent is not particularly limited, but examples thereof include silicone-based defoaming agents, polyether-based defoaming agents, fatty acid ester-based defoaming agents, and acetylene glycol-based defoaming agents. Commercially available defoaming agents include BYK-011, BYK-012, BYK-017, BYK-018, BYK-019, BYK-020, BYK-021, BYK-022, BYK-023, BYK-024, BYK-025, BYK-028, BYK-038, BYK-044, BYK-080A, BYK-094, BYK-095, BYK-096, BYK-097, BYK-098, BYK-099, BYK-010, BYK-011, BYK-012, BYK-017, BYK-018, BYK-019, BYK-020, BYK-021, BYK-022, BYK-023, BYK-024, BYK-025, BYK-028, BYK-038, BYK-044, BYK-080A, BYK-094, BYK-095, BYK-096, BYK-097, BYK-098, BYK-099, BYK-0100, BYK-0102, BYK-0104, BYK-0106, BYK-0108, BYK-0106, BYK-0108, BYK-0109, BYK-0200, Examples of the antifoaming agent include YK-1610, BYK-1615, BYK-1650, BYK-1730, and BYK-1770 (all trade names, manufactured by BYK Japan K.K.), Surfynol DF37, DF110D, DF58, DF75, DF220, MD-20, and Envirogem AD01 (all trade names, manufactured by Nissin Chemical Industry Co., Ltd.). One type of antifoaming agent may be used alone, or two or more types may be used in combination.

The content of the defoaming agent is preferably 0.03 to 0.7% by mass, more preferably 0.05 to 0.5% by mass, and even more preferably 0.08 to 0.3% by mass, based on the total amount of the water-based ink composition.

1.2.1.8. Surfactant The surfactant is not particularly limited, but examples thereof include acetylene glycol-based surfactants, fluorine-based surfactants, and silicone-based surfactants.

The acetylene glycol surfactant is not particularly limited, but is preferably at least one selected from 2,4,7,9-tetramethyl-5-decyne-4,7-diol and alkylene oxide adducts of 2,4,7,9-tetramethyl-5-decyne-4,7-diol, and 2,4-dimethyl-5-decyne-4-ol and alkylene oxide adducts of 2,4-dimethyl-5-decyne-4-ol. Commercially available acetylene glycol surfactants are not particularly limited, but include, for example, E series such as Olfin 104 series and Olfin E1010, Surfynol 465 and Surfynol 61 (all trade names, trade names of Nissin Chemical Industry Co., Ltd.). The acetylene glycol surfactant may be used alone or in combination of two or more types.

The fluorine-based surfactant is not particularly limited, but examples thereof include perfluoroalkyl sulfonate, perfluoroalkyl carboxylate, perfluoroalkyl phosphate, perfluoroalkyl ethylene oxide adduct, perfluoroalkyl betaine, and perfluoroalkyl amine oxide compound. Commercially available fluorine-based surfactants are not particularly limited, but examples thereof include S-144, S-145 (trade names, manufactured by Asahi Glass Co., Ltd.); FC-170C, FC-430, and Fluorad-FC4430 (trade names, manufactured by Sumitomo 3M Limited); FSO, FSO-100, FSN, FSN-100, and FS-300 (trade names, manufactured by Dupont); and FT-250 and 251 (trade names, manufactured by Neos Co., Ltd.). The fluorine-based surfactant may be used alone or in combination of two or more kinds.

Examples of silicone surfactants include polysiloxane compounds, polyether-modified organosiloxanes, etc. Commercially available silicone surfactants are not particularly limited, but specific examples thereof include BYK-306, BYK-307, BYK-333, BYK-341, BYK-345, BYK-346, BYK-347, BYK-348, and BYK-349 (all trade names, manufactured by BYK Japan K.K.), 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, and KF-6017 (all trade names, manufactured by Shin-Etsu Chemical Co., Ltd.). Silicone surfactants may be used alone or in combination of two or more.

The content of the surfactant is preferably 0.3 to 3.0% by mass, more preferably 0.5 to 2.0% by mass, and even more preferably 0.8 to 1.5% by mass, based on the total amount of the water-based ink composition.

1.3. Treatment liquid attachment step The recording method of this embodiment may further include a treatment liquid attachment step of attaching a treatment liquid containing an aggregating agent that aggregates the components of the water-based ink composition to the recording medium. The treatment liquid is attached so that the treatment liquid and the water-based ink composition are in contact with each other on the recording medium. By including such a treatment liquid attachment step, the components of the water-based ink composition tend to aggregate more easily on the surface of the recording medium, and as a result, ink pooling is more suppressed and wet friction resistance tends to be more improved. The treatment liquid may be attached by using an inkjet method as described above, or may be applied by using a bar coater, a roll coater, a spray, or the like. Note that the inkjet method may be exemplified by the same method as the above-mentioned method for ejecting the water-based ink composition.

Of the regions to which the aqueous ink composition and the treatment liquid are applied, in the region where the amount of the aqueous ink composition applied is at its maximum, the amount of the treatment liquid applied is preferably 20% by mass or less, more preferably 2 to 17% by mass, and even more preferably 5 to 15% by mass, relative to the amount of the aqueous ink composition applied. By having the amount of the treatment liquid applied within the above range, ink accumulation is further suppressed, and wet friction resistance tends to be further improved.

The treatment liquid application step may be performed before or after the ink application step. Furthermore, when the treatment liquid application step is performed before the ink application step, the ink application step may be performed before the treatment liquid dries, or after the treatment liquid dries. Furthermore, when the treatment liquid application step is performed after the ink application step, it is preferable to perform the treatment liquid application step before the aqueous ink composition dries.

The treatment liquid is not particularly limited as long as it contains an aggregating agent that aggregates the components of the water-based ink composition, and may contain water, an organic solvent, an antifoaming agent, and a surfactant as necessary. A water-based treatment liquid is preferred.

The flocculant is not particularly limited as long as it can flocculate the components of the aqueous ink composition, but examples of the flocculant include polyvalent metal salts, organic acids, and cationic resins. The flocculants may be used alone or in combination of two or more.

The polyvalent metal salt is not particularly limited, but examples thereof include polyvalent metal salts of inorganic acids or polyvalent metal salts of organic acids. The polyvalent metal is not particularly limited, but examples thereof include alkaline earth metals of Group 2 of the periodic table (e.g., magnesium, calcium), transition metals of Group 3 of the periodic table (e.g., lanthanum), earth metals from Group 13 of the periodic table (e.g., aluminum), and lanthanides (e.g., neodymium). As salts of these polyvalent metals, carboxylates (formic acid, acetic acid, benzoate, etc.), sulfates, nitrates, chlorides, and thiocyanates are suitable. Among them, calcium salts or magnesium salts of carboxylic acids (formic acid, acetic acid, benzoate, etc.), calcium salts or magnesium salts of sulfates, calcium salts or magnesium salts of nitrates, calcium chloride, magnesium chloride, and calcium salts or magnesium salts of thiocyanates are preferred. The polyvalent metal salts may be used alone or in combination of two or more types.

The organic acid is not particularly limited, but examples thereof include acetic acid, oxalic acid, malonic acid, and citric acid. Among these, monovalent or divalent or higher carboxylic acids are preferred. The organic acid may be in the form of a salt. The organic acid or its salt may be used alone or in combination of two or more kinds. Organic acids or their salts that are also polyvalent metal salts are included in the polyvalent metal salts.

The cationic resin is not particularly limited, but examples thereof include amine-based resins such as amine-epichlorohydrin condensation polymers, polyallylamine, and polyallylamine derivatives. The cationic resin is preferably a resin that is soluble in the treatment liquid, or one that disperses in the treatment liquid in the form of a resin emulsion, etc., with the former being more preferred.

The content of the coagulant is preferably 1.0 to 10% by mass, more preferably 3.0 to 10% by mass, and even more preferably 3.0 to 7.0% by mass, relative to the total amount of the treatment liquid. By keeping the content of the coagulant within the above range, ink accumulation is further suppressed, wet friction resistance is further improved, and the resulting recorded matter tends to have improved bleed resistance and filling properties.

The content of water in the treatment liquid is preferably 40% by mass or more, more preferably 50 to 99.5% by mass, even more preferably 55 to 85% by mass, more preferably 60 to 80% by mass, and even more preferably 65 to 75% by mass, based on the total amount of the treatment liquid.

1.3.1.3. Organic solvent The treatment liquid may contain an organic solvent. The type and content of the organic solvent may be the same as those in the ink composition described above. The organic solvent contained in the treatment liquid is not particularly limited, and examples thereof include glycol monoethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol mono-t-butyl ether, triethylene glycol monobutyl ether, 1-methyl-1-methoxybutanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, and dipropylene glycol monobutyl ether; tetraethylene glycol monobutyl ether; diethylene glycol dimethyl ether; Glycol diethers such as ethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol ethyl methyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, and tripropylene glycol dimethyl ether; nitrogen-containing solvents such as 2-pyrrolidone, N-methyl-2-pyrrolidone, and N-ethyl-2-pyrrolidone; glycerin; ethylene glycol, diethylene glycol, tetraethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, and tripropylene glycol dimethyl ether. Examples of the organic solvent include glycols such as polyethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol; and alcohols such as methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butanol, 2-butanol, tert-butanol, iso-butanol, n-pentanol, 2-pentanol, 3-pentanol, and tert-pentanol. Among these, propylene glycol, 2-pyrrolidone, and 1,2-hexanediol are preferred. The organic solvent may be used alone or in combination of two or more.

The content of the organic solvent is preferably 10 to 40% by mass, more preferably 15 to 35% by mass, and even more preferably 20 to 30% by mass, based on the total amount of the treatment liquid.

The treatment liquid may contain an organic solvent equivalent to the specific organic solvent in the water-based ink composition. The specific organic solvent contained in the treatment liquid may be the same as that exemplified in the water-based ink composition. The content of the specific organic solvent contained in the treatment liquid is preferably 1.0% by mass or more, more preferably 1.0 to 15% by mass, even more preferably 1.0 to 8.0% by mass, and even more preferably 1.5 to 4.0% by mass, based on the total amount of the treatment liquid. By having the content of the specific organic solvent be 1.0% by mass or more, ink accumulation is more suppressed and wet friction resistance tends to be more improved. In addition, by having the content of the specific organic solvent be 15% by mass or less, the drying property of the treatment liquid tends to be more improved.

Examples of the defoaming agent contained in the treatment liquid include the same ones as those exemplified for the water-based ink composition. The content of the defoaming agent is preferably 0.03 to 0.7% by mass, more preferably 0.05 to 0.5% by mass, and even more preferably 0.08 to 0.3% by mass, relative to the total amount of the treatment liquid.

1.3.1.5. Surfactant Examples of the surfactant contained in the treatment liquid include the same as those exemplified for the water-based ink composition. The content of the surfactant is preferably 0.5 to 7.0 mass %, more preferably 0.7 to 5.0 mass %, and even more preferably 1.0 to 4.0 mass %, relative to the total amount of the treatment liquid. By having the content of the surfactant within the above range, the wettability of the treatment liquid tends to be further improved.

1.4. Clear ink application process The recording method of the present embodiment may further include a clear ink application process of applying the clear ink composition to the recording medium. The recording medium used in the present embodiment has excellent designability because the recording surface is made of fibers, but the surface is prone to fluffing and tends to have poor wet friction resistance. On the other hand, from the viewpoint of improving wet friction resistance, increasing the amount of resin, etc. contained in the aqueous ink composition is limited from the viewpoint of viscosity suitable for the inkjet method. In this respect, by providing a clear ink application process, the wet friction resistance of the obtained recorded matter tends to be further improved. As a method for applying the clear ink composition, a method of applying using the inkjet method as described above can be mentioned. The clear ink composition is applied so that the aqueous ink composition contacts the recording medium. Furthermore, the clear ink composition may be applied so that the part of the recording medium where the aqueous ink composition contacts the treatment liquid contacts the clear ink composition.

The clear ink application step may be performed before or after the ink application step, but is preferably performed after the ink application step. Furthermore, when the clear ink application step is performed after the ink application step, the clear ink application step may be performed before the water-based ink composition dries, or after the water-based ink composition dries. Furthermore, when the clear ink application step is performed before the ink application step, the ink application step may be performed before the clear ink composition dries, or after the clear ink composition dries.

When the treatment liquid application step is performed, the treatment liquid application step may be performed before or after the clear ink application step. When the treatment liquid application step is performed before the clear ink application step, the clear ink application step may be performed before the treatment liquid dries, or after the treatment liquid dries. Furthermore, when the treatment liquid application step is performed after the clear ink application step, it is preferable to perform the treatment liquid application step before the clear ink composition dries.

In the region where the water-based ink composition and the clear ink composition are adhered, the amount of the clear ink composition adhered is preferably 0.1 to 2.0 mg/inch ² , more preferably 0.3 to 2.0 mg/inch ² , and even more preferably 0.3 to 1.5 mg/inch ^2. If the amount of the clear ink composition adhered is within the above range, the wet friction resistance of the obtained recorded matter tends to be further improved.

1.4.1. Clear ink composition The clear ink composition can be exemplified by the same composition as the water-based ink composition, except for the pigment. Note that the "clear ink" is not an ink used for coloring a recording medium, but an ink used for other purposes. The other purposes include, but are not limited to, improving the properties of the recorded matter, such as wet friction resistance, adjusting the glossiness of the recording medium, and improving the fixability and adhesion of the ink composition. The clear ink composition is not the above-mentioned treatment liquid. A water-based clear ink composition is preferable.

For such purposes, the content of the pigment contained in the clear ink composition is preferably 0.2% by mass or less, more preferably 0.1% by mass or less, even more preferably 0.05% by mass or less, and particularly preferably 0.01% by mass or less, and the lower limit of the content may be 0% by mass.

1.4.1.1 Resin Examples of the resin contained in the clear ink composition include the same resins as those exemplified in the water-based ink composition. Among these, it is preferable to contain at least one of an acrylic resin, a urethane resin, or a polyester resin. By containing such resin particles, wet friction resistance tends to be further improved.

The resin content is preferably 1.0% by mass or more, and more preferably 1 to 20% by mass, relative to the total amount of the clear ink composition. It is even more preferably 2.0 to 8.0% by mass, and even more preferably 2.0 to 6.0% by mass. When the resin content is 1.0% by mass or more, wet friction resistance tends to be further improved. Furthermore, when the resin content is 10% by mass or less, ejection stability and clogging recovery tend to be further improved.

1.4.1.2. Wax Examples of the wax contained in the clear ink composition include the same waxes as those exemplified in the water-based ink composition. The wax content is preferably 0.1 to 5.0% by mass, preferably 0.3 to 3.0% by mass, and preferably 0.3 to 2.0% by mass, relative to the total amount of the clear ink composition. When the wax content is 0.1% by mass or more, wet friction resistance tends to be further improved. Furthermore, when the wax content is 5.0% by mass or less, ejection stability and clogging recovery tend to be further improved.

1.4.1.3. Water The content of water relative to the total amount of the clear ink composition is preferably 40 to 99 mass %, more preferably 55 to 75 mass %, and even more preferably 60 to 70 mass %.

1.4.1.4. Organic Solvent The organic solvent contained in the clear ink composition is not particularly limited, and examples thereof include glycol monoethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol mono-t-butyl ether, triethylene glycol monobutyl ether, 1-methyl-1-methoxybutanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, and tetraethylene glycol monobutyl ether; diethylene glycol dimethyl ether, Glycol diethers such as ethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol ethyl methyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, and tripropylene glycol dimethyl ether; nitrogen-containing solvents such as 2-pyrrolidone, N-methyl-2-pyrrolidone, and N-ethyl-2-pyrrolidone; glycerin; ethylene glycol, diethylene glycol , triethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and other glycols; and alcohols such as methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butanol, 2-butanol, tert-butanol, iso-butanol, n-pentanol, 2-pentanol, 3-pentanol, and tert-pentanol. Among these, propylene glycol, 2-pyrrolidone, 1,2-hexanediol, and the like are preferred. The organic solvent may be used alone or in combination of two or more.

The content of the organic solvent in the clear ink composition is preferably 10 to 40% by mass, more preferably 15 to 35% by mass, and even more preferably 20 to 30% by mass, relative to the total amount of the clear ink composition.

The clear ink composition may contain an organic solvent equivalent to the specific organic solvent in the water-based ink composition. The specific organic solvent contained in the clear ink composition may be the same as that exemplified in the water-based ink composition. The content of the specific organic solvent contained in the clear ink composition is preferably 1.0% by mass or more, more preferably 1.0 to 15% by mass, even more preferably 1.0 to 8.0% by mass, and even more preferably 1.5 to 4.0% by mass, based on the total amount of the clear ink composition. When the content of the specific organic solvent is 1.0% by mass or more, the wet friction resistance tends to be further improved. When the content of the specific organic solvent is 15% by mass or less, the drying property of the clear ink composition tends to be further improved, thereby further improving the wet friction resistance.

[0046] The content of the defoaming agent in the clear ink composition is preferably 0.03 to 0.7% by mass, more preferably 0.05 to 0.5% by mass, and even more preferably 0.08 to 0.3% by mass, based on the total amount of the clear ink composition.

1.4.1.6. Surfactant Examples of surfactants contained in the clear ink composition include those exemplified for the water-based ink composition. The content of the surfactant is preferably 0.3 to 3.0 mass %, more preferably 0.5 to 2.0 mass %, and even more preferably 0.8 to 1.5 mass %, relative to the total amount of the clear ink composition. By having the content of the surfactant within the above range, the wettability of the clear ink composition tends to be further improved.

The recording method of the present embodiment may include a heating step of heating the recording medium during the ink application step, the treatment liquid application step, or the clear ink application step, or between or after these steps. The heating unit for heating the recording medium is not particularly limited, and examples thereof include a platen heater, a hot air heater, an IR heater, and the like, which are provided with a heating function, and a blower, and the like, which are not provided with a heating function.

By heating the recording medium in the ink application process, treatment liquid application process, or clear ink application process, the volatile components of the water-based ink composition, treatment liquid, or clear ink composition that has been applied to the recording medium tend to volatilize more easily, which tends to further suppress ink accumulation.

When the recording medium is heated or not heated in the ink application step, treatment liquid application step, or clear ink application step, the surface temperature of the recording medium in that step is preferably 45°C or lower. On the other hand, it is preferably 15°C or higher. More preferably, it is 20 to 40°C, even more preferably 25 to 38°C, and particularly preferably 30 to 35°C. The above temperature is the maximum temperature of the part of the recording medium surface that receives the application of the composition in the application step. When the temperature is within the above range, it is preferable because it reduces ink pooling, has excellent abrasion resistance, and provides excellent image quality.

In addition, by heating the recording medium during or after the ink application process, treatment liquid application process, or clear ink application process, the drying of the water-based ink composition, treatment liquid, or clear ink composition can be accelerated, which tends to further suppress ink accumulation and further improve wet friction resistance.

2. Inkjet Recording Apparatus As an example of an inkjet recording apparatus used in the maintenance method of this embodiment, a perspective view of a serial printer is shown in Fig. 1. As shown in Fig. 1, the serial printer 200 includes a conveying unit 220 and a recording unit 230. The conveying unit 220 conveys the recording medium F fed to the serial printer to the recording unit 230, and ejects the recording medium after recording outside the serial printer. Specifically, the conveying unit 220 has feed rollers and conveys the fed recording medium F in the sub-scanning directions T1 and T2.

The recording unit 230 also includes an inkjet head 231 that ejects a composition onto the recording medium F sent from the transport unit 220, a carriage 234 that carries the inkjet head, and a carriage movement mechanism 235 that moves the carriage 234 in the main scanning directions S1 and S2 of the recording medium F.

In the case of a serial printer, an inkjet head 231 having a length smaller than the width of the recording medium is provided, and the head moves to perform recording in multiple passes (multi-pass). In a serial printer, the head 231 is mounted on a carriage 234 that moves in a predetermined direction, and the head moves with the movement of the carriage to eject the composition onto the recording medium. In this way, recording is performed in two or more passes (multi-pass). A pass is also called a main scan. A sub-scan is performed between passes to transport the recording medium. In other words, main scans and sub-scans are performed alternately.
The inkjet head 231 is provided with a nozzle row in the sub-scanning direction for ejecting a water-based ink composition. In one main scan, the area where the nozzle row faces the recording medium is the area where ink is deposited in that main scan (deposition area). If the distance of one sub-scan is shorter than the length of the nozzle row in the sub-scanning direction, ink will be further deposited in a certain area of the deposition area in one main scan in another main scan. Thus, ink will be deposited in a certain area (the same area) in one main scan and another main scan.
By doing so, the amount of ink to be applied to a certain area can be divided and applied over two or more main scans, which is preferable in terms of preventing ink pooling and image quality.
When the distance of one sub-scan is approximately 1/n of the length of the nozzle row in the sub-scanning direction, n main scans are performed on the same area of the recording medium, and ink is deposited by the n main scans. The number n is called the number of passes or the number of scans (main scans). By performing main scans on the same area two or more times, ink accumulation is suppressed and image quality is improved, which is preferable. The number of passes is 1 or more, preferably 2 or more, more preferably 3 to 20, even more preferably 4 to 15, and particularly preferably 5 to 10. On the other hand, a smaller number of passes is preferable because it provides a better recording speed.

The recording device of this embodiment is not limited to the serial printer, but may be the line printer described above. Furthermore, the recording device may have a heating unit that heats the recording medium.

The present invention will be described in more detail below using examples and comparative examples. The present invention is not limited in any way by the following examples.

1. Preparation of Water-Based Ink Composition 1.1. Preparation of Pigment Dispersion 40 parts by mass of St-Ac acid copolymer (copolymerized with a mass ratio of methacrylic acid/butyl acrylate/styrene/hydroxyethyl acrylate = 25/50/15/10. Weight average molecular weight 7000, acid value 150 mgKOH/g) was added to a mixture of 7 parts by mass of potassium hydroxide and 53 parts by mass of water, and heated with stirring at 80 ° C. to prepare a resin aqueous solution. 20 parts by mass of pigment (C.I. Pigment Red 122), 10 parts by mass of the resin aqueous solution, and 70 parts by mass of ion-exchanged water were mixed and dispersed using a zirconia bead mill to obtain a magenta pigment dispersion.

Each component was placed in a mixing tank, mixed and stirred, and filtered through a 5 μm membrane filter to obtain the water-based ink composition of each example, so as to obtain the composition shown in Table 1. The numerical values of each component shown in each example in the table represent mass % unless otherwise specified. In addition, in the table, the numerical values of the pigment dispersion represent mass % of the solid content.

The abbreviations and product components used in Table 1 are as follows:
[Other organic solvents]
・Propylene glycol (boiling point 188°C)
・2-pyrrolidone (boiling point 245°C)
[Specific organic solvents]
・1,2-Hexanediol (boiling point 223°C)
・3-methyl-1,5-pentanediol (boiling point 250°C)
・Triethylene glycol monobutyl ether (boiling point 278°C)
・Diethylene glycol monobutyl ether (boiling point 230°C)
[Pigment Dispersion]
・C. I. Pigment Red 122
〔resin〕
Joncryl 631 (styrene acrylic resin, BASF Japan Ltd.)
・Takelac W-6010 (urethane resin, Mitsui Chemicals, Inc.)
〔wax〕
AQUACER 539 (polyethylene wax, BYK Japan Co., Ltd.)
[Antifoaming agent]
Surfynol DF110D (acetylene diol surfactant, Nissin Chemical Industry Co., Ltd.)
[Surfactant]
・BYK348 (silicone surfactant, BYK Japan Co., Ltd.)

2. Preparation of clear ink Each component was placed in a mixing tank, mixed and stirred, and filtered through a 5 μm membrane filter to obtain the clear ink composition of each example, so as to obtain the composition shown in Table 2. The numerical values of each component shown in each example in the table represent mass % unless otherwise specified.

The abbreviations and product components used in Table 2 are as follows:
〔Organic solvent〕
・Propylene glycol ・2-pyrrolidone ・1,2-hexanediol [resin]
Joncryl 631 (styrene acrylic resin, BASF Japan Ltd.)
・Takelac W-6010 (urethane resin, Mitsui Chemicals, Inc.)
〔wax〕
AQUACER 539 (polyethylene wax, BYK Japan Co., Ltd.)
[Antifoaming agent]
Surfynol DF110D (acetylene diol surfactant, Nissin Chemical Industry Co., Ltd.)
[Surfactant]
・BYK348 (silicone surfactant, BYK Japan Co., Ltd.)

3. Preparation of Treatment Liquid Each component was placed in a mixing tank so as to obtain the composition shown in Table 3, mixed and stirred, and then filtered through a 5 μm membrane filter to obtain the treatment liquid of each example.

The abbreviations and product components used in Table 3 are as follows:
〔Organic solvent〕
・Propylene glycol ・2-pyrrolidone ・1,2-hexanediol [flocculant]
・Calcium acetate monohydrate ・Malic acid ・Cation master PD-7 (cation resin, Yokkaichi Chemical Co., Ltd.)
[Antifoaming agent]
Surfynol DF110D (acetylene diol surfactant, Nissin Chemical Industry Co., Ltd.)
[Surfactant]
・BYK348 (silicone surfactant, BYK Japan Co., Ltd.)

4. Inkjet recording media M1: BR4907D (fleece wallpaper, embossed, basis weight 147 g/ ^m2 )
M2: MA8942D (fleece wallpaper, not embossed, weight 150 g/ ^m2 )
・M3: Gunun Kozo (Japanese paper, no embossing, basis weight 42 g/ ^m2 )
・M4: MA8301D HEMP (fleece wallpaper, embossed, weight 160g/ ^m2 )
The above-mentioned embossed means that the entire surface of the recording side of the recording medium is embossed. Note that M3 was embossed before being used for evaluation.

5. Inkjet Recording Apparatus A modified serial type SC-S40650 (manufactured by Seiko Epson Corporation) was used as the inkjet recording apparatus. A secondary drying heater was attached downstream of the inkjet head to dry the ink on the recording medium.
The recording test was carried out as follows. The above-mentioned inkjet recording device was filled with the water-based ink composition, the treatment liquid, and the clear ink composition, and recording was carried out. The image recording conditions were as follows: water-based ink recording resolution: 1440 x 1440 dpi, print pattern: solid image (single color magenta), number of scans in recording the water-based ink composition: 8 times, and secondary drying temperature by the secondary drying heater: 90°C. Furthermore, the type of recording medium, the surface temperature of the recording medium during printing, and the amount of ink or the like attached were as shown in Tables 4 to 5. The printing temperature and secondary drying temperature were determined by measuring the temperature of the recording medium with a thermocouple. In the example in which the treatment liquid and the clear ink composition were used, the patterns were recorded by overlapping them, and the pattern by the treatment liquid, the image by the water-based ink composition, and the pattern by the clear ink were recorded in this order.

6. Evaluation method 6.1. Ink pooling In the recording test, a solid image recording pattern was printed. The test was performed under the conditions for each example in each table. The obtained solid image was visually checked, and the image quality was evaluated according to the following evaluation criteria. For ink pooling, attention was paid to the three-dimensional pattern part of the recording medium, and attention was paid to whether the ink pooled linearly along the boundary of the unevenness of the three-dimensional pattern, making the ink look dark.

(Evaluation criteria)
AA: There is no pool of the water-based ink composition, and no areas appear dark.
A: A small amount of pooling of the water-based ink composition was observed, and thin lines of dark color were slightly seen.
B: A small amount of pooling of the water-based ink composition was observed, and there were a few areas where thick, dark lines were observed, but this did not affect the quality.
C: Pools of the water-based ink composition were observed, and were clearly visible as thick, dark lines.

The water-based ink composition, the treatment liquid, and the clear ink composition were filled into the inkjet recording device, and a solid image was printed on the recording medium under the recording test conditions. The printing conditions were as shown in Tables 4 and 5.

The obtained solid image was left at room temperature for 30 minutes, and then the solid image printed area was cut into a 30 x 150 mm rectangle. The recorded surface of the obtained sample was rubbed 30 times with a Gakushin wet friction tester (load 500 g) using a plain woven cloth that had been soaked in water and then wrung out. The degree of ink peeling when rubbed was visually confirmed, and the wet friction resistance was judged according to the following evaluation criteria.
(Evaluation criteria)
AA: There is no ink transfer to the plain woven fabric, and no peeling of the ink coating.
A: Some of the ink is transferred to the plain weave fabric, but the ink coating does not peel off.
B: Some of the ink was transferred to the plain weave fabric, and slight peeling of the ink coating was observed.
C: The ink coating film is significantly peeled off, or the substrate itself is torn.

A solid image was printed on the recording medium under the conditions of the recording test. The printing conditions were as shown in Tables 4 and 5.

The obtained solid image was dried, and the image quality was visually confirmed and evaluated according to the following evaluation criteria: Focusing on the areas other than the boundaries of the concave and convex portions of the three-dimensional pattern of the recording medium, attention was paid to whether or not bleeding unevenness (ink bleeding causing uneven density) occurred in the solid image.
(Evaluation and Judgment)
AA: No bleeding unevenness is observed in the image.
A: A few small areas of uneven bleeding are observed in the image.
B: Bleed unevenness is observed in some areas of the image, and large bleed unevenness is also observed.
C: There are many areas in the image where there is significant bleeding unevenness.

7. Evaluation Results Tables 4 and 5 show the types of water-based ink composition, treatment liquid, and clear ink composition used in each example, the recording conditions, and the evaluation results.
In all of the Examples, in which recording was performed on a synthetic fiber-containing sheet having a three-dimensional pattern on its surface using a water-based ink composition containing 1.0% by mass or more of the specific organic solvent and 5.0% by mass or less of a pigment, the ink pooling suppression was excellent. In contrast, in all of the Comparative Examples, the ink pooling suppression was poor. Details are described below.

From Examples 1 to 4, it was found that, among the specific organic solvents, alkanediols having 5 or more carbon atoms were superior in wet friction resistance and suppression of ink pooling.
From Examples 1, 5, 6 and 9, it was found that the greater the content of the specific organic solvent, the better the inhibition of ink pooling, and the smaller the content, the better the wet friction resistance.
From Examples 1 and 7, it can be seen that inks with a lower pigment content were more effective in preventing ink pooling.
As can be seen from Examples 1, 10, and 11, the occurrence of ink pooling is reduced when the amount of ink adhesion is smaller, but according to this embodiment, even when a specified amount of ink adhesion is applied, excellent ink pooling suppression is achieved, making it possible to print useful recorded matter such as wallpaper.

Comparing Example 11 with Examples 12 to 15, it is clear that the use of the processing liquid further improves the solid image quality.
Comparing Example 11 with Examples 17 and 18, it can be seen that the use of the clear ink composition results in better wet friction resistance.

From Comparative Examples 1 and 2, when the ink did not contain 1.0% by mass or more of the specific organic solvent, the ink pooling suppression was poor.
From Comparative Example 3, the water-based ink composition containing more than 5.0% by mass of a pigment was inferior in preventing ink pooling.

In Reference Examples 3 and 4, when the sheet did not have a three-dimensional pattern on the surface, the problem of ink puddling did not occur even when the sheet contained synthetic fibers. However, when the sheet did not have a three-dimensional pattern on the surface, it was not possible to record a highly designed recorded matter.
From Reference Examples 1 and 2, when the recording medium was not a synthetic fiber-containing sheet, no ink pooling occurred even if the recording medium had a three-dimensional pattern on the surface. However, it was not possible to record a record having excellent wet friction resistance.

In addition, wallpaper with a three-dimensional pattern made of PVC sheet was also investigated, but it was difficult to adhere with a water-based adhesive, and was not preferable. In addition, the presence or absence of a specific organic solvent contained in the water-based ink composition of the present embodiment and its content did not affect the ink pooling, and the effect of the present embodiment was not obtained.
Although not shown in the table, when the number of scans was increased to 12 in Example 1 and printing was performed in the same manner, ink puddling was suppressed and solid image quality was improved. The greater the number of scans, the better the ink puddling suppression and solid image quality.

200... serial printer, 220... transport unit, 230... recording unit, 234... carriage, 235... carriage movement mechanism

Claims (15)

A recording method for recording on a recording medium, comprising the steps of:
the recording medium is a synthetic fiber-containing sheet made of nonwoven fabric having a three-dimensional pattern embossed on its surface,
an ink depositing step of ejecting the water-based ink composition from an inkjet head and depositing the ink composition on the recording medium;
The water-based ink composition contains a pigment, water, and an organic solvent,
the content of the pigment is 5.0% by mass or less with respect to the total amount of the water-based ink composition;
the organic solvent contains either a glycol ether or an alkanediol having 5 or more carbon atoms,
the total content of the glycol ethers or the alkanediols having 5 or more carbon atoms is 1.0% by mass or more with respect to the total amount of the water-based ink composition;
Recording method. In the ink application step, the maximum amount of the water-based ink composition applied is 20 mg/inch2 or ^less .
The recording method according to claim 1 . The synthetic fiber-containing sheet has a basis weight of 100 g/ ^m2 or more.
The recording method according to claim 1 or 2. A treatment liquid applying step of applying a treatment liquid containing a flocculant to the recording medium.
The recording method according to any one of claims 1 to 3. In a region where the amount of the water-based ink composition adhered is maximum among the regions to which the water-based ink composition and the treatment liquid are adhered,
the amount of the treatment liquid adhered is 20% by mass or less relative to the amount of the water-based ink composition adhered;
The recording method according to claim 4. A clear ink applying step of applying a clear ink composition to the recording medium is provided.
The recording method according to any one of claims 1 to 5. the clear ink composition contains a resin,
The resin includes any one of an acrylic resin, a urethane resin, and a polyester resin.
The recording method according to claim 6. The recording method according to any one of claims 1 to 7, wherein the synthetic fiber-containing sheet is a nonwoven fabric containing the synthetic fibers and natural fibers. The content of the pigment is 0.5 to 5.0% by mass with respect to the total amount of the water-based ink composition.
The recording method according to any one of claims 1 to 8. the total content of the glycol ethers or the alkanediols having 5 or more carbon atoms is 1.0 to 15% by mass with respect to the total amount of the water-based ink composition;
The recording method according to any one of claims 1 to 9. The organic solvent includes an organic solvent having a normal boiling point of 160 to 280°C.
The recording method according to any one of claims 1 to 10. The recording method according to any one of claims 1 to 11, wherein the water-based ink composition contains resin particles, and the resin particles are made of any one of an acrylic resin, a urethane resin, and a polyester resin. In the ink application step, a main scan is performed in which the inkjet head is moved in a main scanning direction intersecting a sub-scanning direction of the recording medium, while discharging the water-based ink composition and applying it to the recording medium;
The main scanning is performed a plurality of times,
The main scanning is performed two or more times in the same area.
The recording method according to any one of claims 1 to 12. The recorded matter is used as wallpaper.
The recording method according to any one of claims 1 to 13. The water-based ink composition does not contain more than 1% by mass of an organic solvent having a normal boiling point of more than 280° C.
The recording method according to any one of claims 1 to 14.