Pretreatment composition

Abstract

To provide an ink set of a pretreatment composition and color ink, wherein the pretreatment composition hardly causes traces of pretreatment, lowering of color development due to strike-through, and fuzzing, and provides an image having high whiteness and high concealing property when color ink containing white color is used, and also to provide an inkjet printing method.SOLUTION: A pretreatment composition contains a cationic polymer having a weight average molecular weight of 700 or more and 6,000 or less, resin particles, a crosslinking agent, and water, wherein the resin particles have a contact angle (ca1) of 84° or more after 1 second from liquid contact of water on a resin coating film, a contact angle (ca2) of 65° or more after 10 seconds from the liquid contact of the water on the resin coating film, and when the total mass of the cationic polymer having the weight average molecular weight of 700 or more and 6,000 or less is represented by A and the total mass of the resin particles is represented by B, a value determined by A / B is within a range of 0.8 to 3.7.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a pretreatment composition for inkjet textile printing, an inkjet textile printing method, an ink set containing the pretreatment composition, and a printed material printed using the ink set. [Background technology]

[0002] Traditionally, hand-drawing and screen printing have been the mainstream methods for textile printing, but recently, textile printing using inkjet printers (inkjet printing) has become increasingly popular. Inkjet printing methods are more suitable for printing a wide variety of items in small quantities than analog printing methods such as screen printing and gravure printing, and there is a demand for an expanded range of fabric applications for inkjet printing methods. Along with this expansion of the range of applications, there is a demand for further improvements in density and fastness (e.g., rubbing fastness, washing fastness, lightfastness, etc.) in garment printing and home textile printing for various fabrics (e.g., cotton, polyester, nylon, or blends containing two or more types of fibers) and various types of fabrics (e.g., knit, sheeting, broadcloth, oxford, chambray, mesh, etc.).

[0003] Water-soluble dyes are used as colorants in inkjet printing. Such dyes have vivid hues and a wide color gamut that can be reproduced. On the other hand, water-soluble dyes have drawbacks such as low lightfastness and complicated processes such as fixing and washing after the dye is attached to the fiber, as well as the disposal of waste dye liquid generated by washing. For these reasons, the use of water-insoluble colorants instead of water-soluble dyes has attracted attention.

[0004] In inkjet printing using water-insoluble colorants, bleeding on the fabric has been a problem. To address this problem, it has been proposed to pretreat the fabric. For example, Patent Documents 1 and 2 listed below propose such treatment solutions.

[0005] On the other hand, when printing on one side of polyester fibers (mesh fabrics used in sportswear, etc.), or thin or loosely woven fibers, the colorant can penetrate to the other side of the fabric, which is not printed, causing a "bleed-through" problem, which is one of the major problems that reduces density. Pretreatment of fibers has also been proposed to prevent this bleed-through. However, if a high concentration pretreatment liquid (hereinafter also referred to as a pretreatment composition) or a large amount of pretreatment liquid is applied to the fibers in an effort to prevent bleed-through, a problem arises in that "traces" of the pretreatment liquid remain on the fibers in the areas where the pretreatment liquid was applied, which is also a problem. "Traces" are observed as a whitish appearance on dark-colored fibers, such as black. On the other hand, on light-colored fibers, such as light blue, they are observed as a darker color, as if wet. The presence of such traces significantly deteriorates the appearance of the printed textile. This can lead to a decrease or even loss of the commercial value of the printed textile, so there is a strong demand for a pretreatment liquid that not only prevents bleed-through but also leaves no "traces."

[0006] Furthermore, when color inks other than white are directly printed on dark-colored fibers, including black, the color of the color ink may not be visible to the naked eye. For this reason, when printing color inks on dark-colored fibers, a white base is usually placed on the base, and the color inks are printed on this base. If the whiteness of this base is low, the color development of the image printed with the color inks will be reduced. For this reason, it is desirable for the whiteness and hiding power of the base to be high. However, it is known that the whiteness and hiding power may be reduced depending on the type of pretreatment liquid. Furthermore, when applying a white ink base to dark-colored fabrics, the above-mentioned "bleed-through" can occur depending on the type of fabric (fabric), which is one of the major problems that reduces whiteness and hiding power. In particular, polyester fabrics (mesh fabrics used in sportswear, etc.) or thin or coarsely woven fabrics tend to experience significant reductions in whiteness and hiding power. In addition to bleed-through, the fibers in the pre-treated area may become frayed, causing unevenness in the white background. This unevenness also significantly reduces the quality of the printed product. Therefore, there is a strong demand for a pretreatment composition, a textile printing method, and an ink set with color inks that can solve these problems.

[0007] Furthermore, when printing light-colored fibers including white with color inks such as yellow, cyan, magenta, red, blue, violet, orange, and black, it is common to apply these color inks directly to the fibers without providing a white undercoat. Even in such cases, there is a strong demand for a pretreatment composition, a printing method, and an ink set of color inks that can produce color images with high color development. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 07-119047 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-226781 Summary of the Invention [Problem to be solved by the invention]

[0009] An object of the present invention is to provide an ink set of a pretreatment composition and a color ink, and an inkjet printing method, which are less likely to cause the above-mentioned marks, strike-through, and fuzzing, and which, when a color ink containing white is used, give an image having high whiteness and high hiding power. [Means for solving the problem]

[0010] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by a pretreatment composition comprising a cationic polymer having a weight-average molecular weight of 700 to 6000, resin particles, a crosslinking agent, and water, wherein the resin particles have a contact angle (ca1) of 84° or more 1 second after water is applied to the resin coating film and a contact angle (ca2) of 65° or more 10 seconds after water is applied to the resin coating film, and wherein, when A is the total mass of the cationic polymer having a weight-average molecular weight of 700 to 6000 and B is the total mass of the resin particles, the value A / B is in the range of 0.8 to 3.7, and have completed the present invention. That is, the present invention relates to the following 1) to 10). 1) A pretreatment composition comprising a cationic polymer having a weight-average molecular weight of 700 or more and 6000 or less, resin particles, a crosslinking agent, and water, wherein the resin particles have a contact angle (ca1) of 84° or more 1 second after water is applied to a resin coating film, and a contact angle (ca2) of 65° or more 10 seconds after water is applied to a resin coating film, and wherein, when the total mass of the cationic polymer having a weight-average molecular weight of 700 or more and 6000 or less is A and the total mass of the resin particles is B, the value calculated by A / B is in the range of 0.8 to 3.7. 2) 1), wherein the cationic polymer having a weight average molecular weight of 700 or more and 6000 or less contains at least one structural unit selected from the group consisting of an allylamine structural unit, a diallylamine structural unit, a diallylammonium structural unit, and an epihalohydrin structural unit. 3) The pretreatment composition according to 1) or 2), wherein the crosslinking agent comprises at least one selected from the group consisting of a blocked isocyanate group-containing compound, a carbodiimide group-containing compound, and an oxazoline group-containing compound. 4) 3) The pretreatment composition according to 3), wherein the dissociation temperature of the blocked isocyanate group-containing compound is 120°C or higher. 5) The pretreatment composition according to any one of 1) to 4), which has a static surface tension at 25°C of 36 to 60 mN / m. 6) The pretreatment composition according to any one of 1) to 5), which has a pH of 6.5 to 10.0. 7) An ink set comprising the pretreatment composition according to any one of 1) to 6) above, and a water-based ink composition containing a pigment, a polymer dispersant, a urethane resin, a water-soluble organic solvent, a surfactant, and water. 8) 7) The ink set according to 7), wherein the pigment is a white pigment, the water-soluble organic solvent contains a polyhydric alcohol having a boiling point of 250°C or higher and a polyhydric alcohol having a boiling point of 210°C or lower, and the content of the polyhydric alcohol having a boiling point of 250°C or higher is 20% by mass or lower relative to the total mass of the water-based ink composition. 9) An inkjet textile printing method comprising: a pretreatment step of applying a pretreatment composition according to any one of 1) to 6) above to a fabric; a first drying step of drying the pretreatment composition applied to the fabric; a recording step of applying an ink to at least a part of the pretreatment layer formed on the fabric by the first drying step; and a second drying step of drying the ink. 10) A printed matter printed using the ink set according to 7) or 8). [Effects of the Invention]

[0011] The present invention has provided an ink set of a pretreatment composition and a color ink, and an inkjet printing method that are less likely to cause the above-mentioned marks and strike-through and that can obtain images with high color development when color inks containing white are used. DETAILED DESCRIPTION OF THE INVENTION

[0012] The best mode for carrying out the present invention will be described in detail below, but the present invention is not limited thereto. Furthermore, unless otherwise specified, "%" and "parts" in this specification, including the examples, are all expressed on a mass basis.

[0013] [Pretreatment composition] The pretreatment composition includes a cationic polymer having a weight-average molecular weight of 700 to 6000, resin particles, a crosslinking agent, and water, wherein the resin particles have a contact angle (ca1) of 84° or greater 1 second after water is applied to the resin coating film, and a contact angle (ca2) of 65° or greater 10 seconds after water is applied to the resin coating film, and the ratio A / B is in the range of 0.8 to 3.7, where A is the total mass of the cationic polymer having a weight-average molecular weight of 700 to 6000 and B is the total mass of the resin particles. In this specification, the "cationic polymer having a weight-average molecular weight of 700 to 6000" may be abbreviated as "cationic polymer" and the "water-based ink composition" may be abbreviated as "ink."

[0014] The pretreatment composition will now be described in detail.

[0015] [Cationic polymer] The pretreatment composition contains a cationic polymer, which improves the cohesion of the resin-coated colorant in the ink, as described below. The cationic polymer preferably contains at least one selected from the group consisting of an allylamine structural unit, a diallylamine structural unit, a diallylammonium structural unit, and an epihalohydrin structural unit, more preferably contains at least one selected from the group consisting of an allylamine structural unit, a diallylamine structural unit, and an epihalohydrin structural unit, and is particularly preferably a cationic polymer containing an epihalohydrin structural unit. All of the above cationic polymers are strong electrolytes, and have good dissolution stability in the pretreatment composition and excellent ability to reduce the dispersion of pigments in ink.

[0016] The cationic polymer containing an allylamine structural unit can be appropriately selected from known polymers and used. Examples thereof include polyallylamine hydrochloride, polyallylamine amidosulfate, allylamine hydrochloride-diallylamine hydrochloride copolymer, allylamine acetate-diallylamine acetate copolymer, allylamine acetate-diallylamine acetate copolymer, allylamine hydrochloride-dimethylallylamine hydrochloride copolymer, allylamine-dimethylallylamine copolymer, polydiallylamine hydrochloride, polymethyldiallylamine hydrochloride, polymethyldiallylamine amidosulfate, polymethyldiallylamine acetate, polydiallyldimethylammonium chloride, diallylamine acetate-sulfur dioxide copolymer, diallylmethylethylammonium ethyl sulfate-sulfur dioxide copolymer, methyldiallylamine hydrochloride-sulfur dioxide copolymer, diallyldimethylammonium chloride-sulfur dioxide copolymer, diallyldimethylammonium chloride-acrylamide copolymer, and the like. Commercially available cationic polymers containing allylamine structural units can be used, and specific examples thereof include PAA-HCL-01, PAA-HCL-03, PAA-HCL-05, PAA-HCL-3L, PAA-HCL-10L, PAA-H-HCL, PAA-SA, PAA-01, PAA-03, PAA-05, PAA-08, PAA-15, PAA-15C, PAA-25, and PAA-16. Examples of suitable anticoagulants that can be used include AA-H-10C, PAA-D11-HCL, PAA-D41-HCL, PAA-D19-HCL, PAS-21CL, PAS-M-1L, PAS-M-1, PAS-22SA, PAS-M-1A, PAS-H-1L, PAS-H-5L, PAS-H-10L, PAS-92, PAS-92A, PAS-J-81L, and PAS-J-81 (all trade names, manufactured by Nittobo Medical Co., Ltd.), Hymo Neo-600, Himolock Q-101, Q-311, and Q-501, and Himax SC-505 and SC-505 (all trade names, manufactured by Hymo Co., Ltd.).

[0017] As the cationic polymer containing the diallylamine structural unit, any known cationic polymer can be appropriately selected and used. Specific examples include PAS-21CL, PAS-21, PAS-M-1L, PAS-M-1, PAS-M-1A, PAS-92, and PAS-92A (manufactured by Nittobo Medical Co., Ltd.); and Unisense KCA100L and KCA101L (manufactured by Senka Corporation).

[0018] As the cationic polymer containing the diallylammonium structural unit, known ones can be appropriately selected and used, and specific examples thereof include the hydrochloride or ethyl sulfate salt of diallyldimethylammonium or diallylmethylethylammonium. The cationic polymer containing the diallylammonium structural unit is preferred because it exhibits particularly excellent cohesive properties and can produce printed matter on a substrate with little color bleeding or color unevenness and excellent color development. Commercially available cationic polymers containing diallylammonium structural units can be used, and specific examples thereof include PAS-H-1L, PAS-H-5L, PAS-H-10L, PAS-24, PAS-J-81L, PAS-J-81, and PAS-J-41 (manufactured by Nittobo Medical Co., Ltd.); Unisense FPA100L, FPA101L, FPA102L, FPA1000L, FPA1001L, FPA1002L, FCA1000L, FCA1001L, and FCA5000L (manufactured by Senka Chemical Co., Ltd.). Furthermore, a commercially available cationic polymer compound containing both diallylamine structural units and diallylammonium structural units is PAS-880 (manufactured by Nittobo Medical Co., Ltd.).

[0019] The cationic polymer containing the epihalohydrin structural unit can be appropriately selected from known materials, and specific examples thereof include epihalohydrin-modified polyamine compounds, epihalohydrin-modified polyamide compounds, epihalohydrin-modified polyamidepolyamine compounds, and epihalohydrin-amine copolymers. Furthermore, from the viewpoint of availability, epichlorohydrin or methylepichlorohydrin is preferably selected as the epihalohydrin. Printed materials using the cationic polymer containing the epihalohydrin structural unit have excellent water resistance, and are therefore also preferably selected from this viewpoint. Commercially available products can be used as the cationic polymer containing an epihalohydrin structural unit, and specific examples thereof include FL-14 (manufactured by SNF Corporation), Arafix 100, 251S, 255, and 255LOX (manufactured by Arakawa Chemical Industries, Ltd.), DK-6810, 6804, 6850, 6854, and 6885; and WS-4010, 4011, 4020, 4024, 4027, and 4030 (manufactured by Seiko PMC Corporation). , Unisense KHE100L, Papiogen P-105 (manufactured by Senka Co., Ltd.), Sumirez Resin 650 (30), 675A, 6615, SLX-1 (manufactured by Taoka Chemical Co., Ltd.), Catiomaster PD-7, 30, A, PDT-2, PE-10, PE-30, DT-EH, EPA-SK01, TMHMDA-E (manufactured by Yokkaichi Synthetic Co., Ltd.), Jetfix 36N, 38A, 5052 (manufactured by Satoda Chemical Co., Ltd.).

[0020] The cationic polymer preferably contains any resin selected from the group consisting of epihalohydrin-modified polyamine resins, epihalohydrin-modified polyamide resins, epihalohydrin-modified polyamidepolyamine resins, and epihalohydrin-amine copolymers.

[0021] The cationic polymer may be a product synthesized by a known synthesis method, or a commercially available product.

[0022] The pretreatment composition may further contain an "other cationic polymer" other than the above cationic polymer. The "other cationic polymer" is not particularly limited as long as it is a polymer other than the above cationic polymer and has cationic properties, and is preferably an epihalohydrin-modified polyamine resin.

[0023] The total content of the cationic polymer and the "other cationic polymer" is preferably more than 3.0% by mass and less than 10.0% by mass, more preferably 3.5 to 8.0% by mass, even more preferably 4.0 to 7.0% by mass, and particularly preferably 4.5 to 6.0% by mass, based on the total mass of the pretreatment composition. Addition of more than 3.0% by mass tends to provide effective coagulation ability and improve strike-through and whiteness. Addition of less than 10.0% by mass tends to improve the storage stability of the pretreatment composition, reduce traces on printed matter, and improve the abrasion fastness of printed matter.

[0024] The viscosity of the above cationic polymer in a 10% by mass aqueous solution at 25°C is preferably 1.0 to 5.0 mPa·s, more preferably 1.0 to 2.5 mPa·s, even more preferably 1.0 to 2.0 mPa·s, and extremely preferably 1.0 to 1.5 mPa·s. Selecting a cationic polymer such that the viscosity of a 10% by mass aqueous solution is 5.0 to 1.0 tends to improve the fluidity of the pretreatment composition and the color development during printing.

[0025] The weight-average molecular weight of the cationic polymer is 700 or more and 6000 or less. Taking into consideration miscibility with other components contained in the pretreatment composition, the water resistance of the fabric after pretreatment, and washing fastness and adhesion, it is preferably 1000 to 6000, more preferably 1500 to 6000. If it is 700 or more, effective coagulation ability is obtained, and strike-through, whiteness, and washing fastness tend to be good. If it is 6000 or less, it can be used as an aqueous solution, and the storage stability of the pretreatment composition tends to be excellent. Furthermore, by setting it to 6000 or less, the occurrence of unevenness on a white background tends to be suppressed and a decrease in whiteness tends to be reduced.

[0026] [Resin particles] The pretreatment composition contains resin particles having a contact angle (ca1) of 84° or more 1 second after water is applied to the resin coating film, and a contact angle (ca2) of 65° or more 10 seconds after water is applied to the resin coating film. In this specification, the above resin particles may be referred to as "specific resin particles."

[0027] The specific resin particles have a contact angle (ca1) of 84° or more, preferably 90° or more, and more preferably 95° or more, when water hits the resin coating film 1 second after the particles hit the resin coating film, and a contact angle (ca2) of 65° or more, preferably 80° or more, and more preferably 90° or more, when water hits the resin coating film 10 seconds after the particles hit the resin coating film. When the contact angle (ca1) of water on the resin coating film 1 second after it hits the surface is 84° or more, and the contact angle (ca2) of water on the resin coating film 10 seconds after it hits the surface is 65° or more, the ink is prevented from penetrating into the fibers of fabrics containing hydrophobic fibers, allowing the ink (colorant) to fix on the fiber surface, which tends to improve whiteness and hiding power.

[0028] There are no particular upper limits to the contact angle (ca1) of water 1 second after it hits the resin coating film and the contact angle (ca2) of water 10 seconds after it hits the resin coating film, but an example of an upper limit is 115° or less. By setting the contact angle to 115° or less, the uniformity of a solid image improves and image spots tend to be less likely to occur.

[0029] The contact angle of water on the resin coating film is measured by the following method. A contact angle measurement solution was prepared by adding water to an emulsion of resin particles to be measured, so that the solid content was 25% by mass. The solution was then applied to an OHP film (model CG3110, 3M) using a bar coater (ROD No. 8, Yasuda Seiki Seisakusho Co., Ltd.) and dried at 70°C for 6 hours to produce a film. A contact angle meter, DM-501Hi (Kyowa Interface Science Co., Ltd.), was used to measure the contact angle (ca1) of the resin coating 1 second after water contact and the contact angle (ca1) of the resin coating 10 seconds after water contact, using a 2 μL droplet.

[0030] When two or more different types of specific resin particles are contained in the pretreatment composition, the content of each specific resin particle in the contact angle measurement liquid is determined according to the mass fraction of each specific resin particle in the pretreatment liquid composition so that the total mass of the specific resin particles is 25 mass% as the solid content. For example, when the pretreatment composition contains 20 mass% of first specific resin particles and 80 mass% of second specific resin particles relative to the total mass of the specific resin particles, the contact angle measurement liquid is made using resin particles containing 5 mass% of the first specific resin as a solid content and 20 mass% of the second specific resin as a solid content.

[0031] Examples of the specific resin particles include (meth)acrylic resins, (meth)acrylic resin copolymers, styrene-maleic anhydride copolymer resins, epoxy resins, urethane resins, polyether resins, polyamide resins, unsaturated polyester resins, phenolic resins, silicone resins, fluororesins, polyvinyl resins (vinyl chloride, vinyl acetate, polyvinyl alcohol, etc.), vinyl acetate-(meth)acrylic copolymer resins, vinyl acetate-ethylene copolymer resins, alkyd resins, polyester resins, amino resins (melamine resins, urea resins, melamine formaldehyde resins, etc.), hydrocarbon resins, and the like. The specific resin particles may contain two or more types of resins. At least one of the two or more types of resins may form a core / shell structure. The specific resin particles may be used singly or in combination of two or more types. Among the specific resin particles, it is preferable to use a resin that forms a transparent coating film, and from the viewpoints of the storage stability, friction resistance, and adhesion of the pretreatment composition, (meth)acrylic resins, (meth)acrylic resin copolymers, urethane resins, polyester resins, and hydrocarbon resins are preferred.

[0032] The specific resin particles are preferably water-dispersible. In the present disclosure, water-dispersible means that no precipitation is observed even after stirring in water at 20°C and leaving at 20°C for 60 minutes.

[0033] The specific resin particles containing the (meth)acrylic resin or the (meth)acrylic resin copolymer are commercially available, and many of them are emulsions with a solid content of 30 to 60% by mass, such as Movinyl 966A, 6718, 6750, 6751D, 6950, 6951, 6963, 6960, and 7820 manufactured by Japan Coating Resins Co., Ltd.

[0034] The specific resin particles containing the urethane resin are commercially available, and many of them are emulsions with a solid content of 30 to 60% by mass. Commercially available urethane resin emulsions include, for example, Permarin UA-150, 200, 310, 368, 3945, and U-coat UX-320 (all manufactured by Sanyo Chemical Industry Co., Ltd.); Hydran WLS-201, 210, and HW-312B latex (all manufactured by DIC Corporation); and Superflex 150, 170, and 470 (all manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.). Among these, examples of polycarbonate-based urethane resins include Permarin UA-310 and 3945; U-coat UX-320; and Hydran WLS-210, 213, and 250. Examples of polyether urethane resins include Permarin UA-150 and 200; U-coat UX-340; and Hydran WLS-201, 202, and 230.

[0035] When the urethane resin in the urethane resin emulsion has acidic groups such as carboxyl, sulfo, or hydroxyl groups, the acidic groups may be converted into alkali salts. For example, the acidic groups can be converted into alkali salts by adding the urethane resin having acidic groups to water and stirring to prepare an aqueous solution, and then adding an alkaline compound to adjust the pH to 6.0 to 12.0. Examples of alkaline compounds include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; and alkaline earth metal hydroxides such as beryllium hydroxide, magnesium hydroxide, calcium hydroxide, and strontium hydroxide. One type of alkaline compound may be used alone, or two or more types may be used in combination.

[0036] The content of the specific resin particles is preferably 1.0 to 15.0% by mass, more preferably 1.5 to 12.0% by mass, even more preferably 2.0 to 10.0% by mass, and particularly preferably 2.3 to 8.0% by mass, based on the total mass of the pretreatment composition. A content of 1.0% by mass or more tends to suppress ink strike-through, resulting in high whiteness and excellent color development. Furthermore, a content of 15.0% by mass or less tends to improve the storage stability of the pretreatment composition and reduce traces on printed materials.

[0037] [Crosslinking agent] The pretreatment composition contains a crosslinking agent. The crosslinking agent is not particularly limited as long as it has a crosslinking function. Examples include blocked isocyanate group-containing compounds, compounds having epoxy groups, compounds having oxazoline groups, carbodiimide group-containing compounds, compounds having methylol groups, compounds having cyclocarbonate groups, compounds having azirinyl groups, compounds having acetoacetyl groups, and compounds having silanol groups. These may be used alone or in combination of two or more. Among these, carbodiimide group-containing compounds, oxazoline group-containing compounds, blocked isocyanate group-containing compounds, and epoxy group-containing compounds are preferred from the viewpoint of improving water resistance. It is more preferred to include any compound selected from the group consisting of blocked isocyanate group-containing compounds, oxazoline group-containing compounds, and carbodiimide group-containing compounds. It is particularly preferred to include any compound selected from the group consisting of blocked isocyanate group-containing compounds and oxazoline group-containing compounds. The crosslinking agent may be either a water-soluble compound or a water-dispersible compound. However, from the viewpoint of storage stability, a water-dispersible compound is preferred. In the present invention, the term "blocked isocyanate group-containing compound" refers to a compound in which the isocyanate group in a polyisocyanate compound is blocked with a blocking agent.

[0038] The blocked isocyanate group-containing compound refers to a polyisocyanate compound in which the isocyanate group has been blocked with a blocking agent. Blocking the highly reactive isocyanate group stabilizes the isocyanate group, improving the storage stability of the aqueous composition while enabling the formation of a strong ink film after the crosslinking reaction. The polyisocyanate compound is a compound having two or more isocyanate groups per molecule. Examples of such polyisocyanate compounds include aliphatic isocyanates, alicyclic isocyanates, araliphatic isocyanates, aromatic isocyanates, and modified versions of these. Modified polyisocyanate compounds include polymers such as isocyanurates; biuret compounds; and adducts of trimethylolpropane and pentaerythritol with polyhydric alcohols.

[0039] The aliphatic isocyanate is preferably, for example, a diisocyanate having a linear or branched aliphatic hydrocarbon group between two isocyanate groups. The carbon number of the aliphatic hydrocarbon group is preferably 2 or more, more preferably 3 or more, and preferably 10 or less, more preferably 9 or less, and even more preferably 8 or less. Specific examples include tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate (HDI), heptamethylene diisocyanate, octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, 2,2,4- or 2,4,4-trimethylhexamethylene diisocyanate, etc. Examples of the alicyclic isocyanate include hydrogenated xylylene diisocyanate (H6XDI), 1,4-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate (H12MDI), isophorone diisocyanate (IPDI), 2,5- or 2,6-norbornane diisocyanate, etc. Examples of the araliphatic isocyanate include m- or p-xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), etc. Examples of the aromatic isocyanate include 1,3- or 1,4-phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate (TDI), 4,4'- or 2,4'-diphenylmethane diisocyanate (MDI), m- or p-isocyanatophenylsulfonyl isocyanate, 4,4'-diisocyanatobiphenyl, 4,4'-diisocyanato-3,3'-dimethylbiphenyl, 1,5-naphthylene diisocyanate, and 2,6-dimethylbenzene-1,4-diisocyanate.

[0040] Examples of the blocking agent include compounds having active hydrogen, such as amines such as 3,5-dimethylpyrazole (DMP), 1,2,4-triazole, and diisopropylamine; phenols such as phenol and cresol; oximes such as methyl ethyl ketoxime; lactams such as ε-caprolactam; and active methylene compounds such as diethyl malonate and ethyl acetoacetate. Among these, 3,5-dimethylpyrazole (DMP) is preferred from the viewpoints of stability, yellowing resistance, and safety.

[0041] The dissociation temperature of the blocked isocyanate group-containing compound is preferably 120°C or higher, more preferably 125°C or higher, from the viewpoints of storage stability, friction fastness, and adhesion. At 120°C or higher, the storage stability of the pretreatment composition tends to improve. Furthermore, from the viewpoint of suppressing damage such as deformation of the recording medium, the dissociation temperature is preferably 150°C or lower, more preferably 130°C or lower. In particular, when polyester or a blend containing polyester is used for the fabric, the drying step after printing must be carried out at a drying temperature of 130°C or lower to prevent dye migration (hereinafter also simply referred to as dye transfer), so a dissociation temperature of 130°C or lower is preferred.

[0042] Commercially available blocked isocyanate group-containing compounds include, for example, Trixene blocked isocyanates Aqua BI200, Aqua BI220, 7950, 7951, 7960, 7961, 7982, 7990, 7991, and 7992 (all of which are trade names manufactured by Baxenden); DM-6400, Meikanate DM-3031CONC, Meikanate FM-1, Meikanate DM-35HC, Meikanate TP-10, Meikanate ST, Meikanate PRO, NBP-873D, Meikanate NS-1, and Meikanate DX (all of which are trade names manufactured by Meisei Chemical Industry Co., Ltd.); and Elastron BN-6. Examples of such surfactants include BN-9, BN-77, BN-27, and BN-11 (all manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade names); Takenate WB-700, WB-770, and WB-920 (all manufactured by Mitsui Chemicals, Inc., trade names); Duranate MF-K60B, SBN-70D, MF-B60B, MF-B90B, 17B-60P, TPA-B80B, TPA-B80E, and E402-B80B (all manufactured by Asahi Kasei Corporation, trade names); and Fixer N (manufactured by Matsui Dye Chemical Research Institute, Inc.).

[0043] From the viewpoints of the storage stability, friction fastness, solvent resistance, and adhesion of the pretreatment composition, the carbodiimide group-containing compound is preferably a polycarbodiimide compound containing two or more carbodiimide groups per molecule. A preferred example of the carbodiimide group-containing compound is one obtained by capping, with a hydrophilic group, the terminal isocyanate group of a condensation reaction product obtained by a decarboxylation condensation reaction of diisocyanates in the presence of a carbodiimidization catalyst.

[0044] Examples of diisocyanates used in the decarboxylation condensation reaction include aliphatic diisocyanates such as hexamethylene diisocyanate (HDI), decamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate; 4,4'-dicyclohexylmethane diisocyanate (H12MDI), isophorone diisocyanate (IPDI), 2,5- or 2,6-norbornane diisocyanate, hydrogenated xylylene diisocyanate (H6XDI), hydrogenated tolylene diisocyanate, and 2,4-bis-(8 alicyclic diisocyanates such as (-isocyanatooctyl)-1,3-dioctylcyclobutane (OCDI); araliphatic diisocyanates such as m- or p-xylylene diisocyanate (XDI) and tetramethylxylylene diisocyanate (TMXDI); and aromatic diisocyanates such as 2,4,6-triisopropylphenyl diisocyanate (TIDI), 4,4'- or 2',4-diphenylmethane diisocyanate (MDI), and 2,4- or 2,6-tolylene diisocyanate (TDI).

[0045] The compound obtained by capping the terminal isocyanate group of the condensation reaction product with a hydrophilic group is a compound having a functional group capable of reacting with the isocyanate group, such as polyethylene glycol monomethyl ether or polypropylene glycol monomethyl ether. Among these, polyethylene glycol monomethyl ether is preferred from the viewpoints of the compoundability of the carbodiimide group-containing compound in the pretreatment composition and the storage stability of the pretreatment composition. The number of moles of ethylene oxide added to the polyethylene glycol monomethyl ether can be adjusted, and the resulting carbodiimide group-containing polymer can be incorporated into the aqueous composition in the form of an emulsion or aqueous solution.

[0046] From the viewpoints of the storage stability, friction fastness, solvent resistance, and substrate adhesion of the pretreatment composition, the carbodiimide group-containing compound is preferably incorporated into the pretreatment composition as an aqueous solution or emulsion, and from the viewpoint of the storage stability of the pretreatment composition, it is preferably incorporated into the pretreatment composition as an aqueous solution. Commercially available examples of the carbodiimide group-containing compound include Carbodilite E-02, Carbodilite E-03A, Carbodilite E-05, Carbodilite V-02, Carbodilite V-02-L2, and Carbodilite V-04 (all of which are trade names manufactured by Nisshinbo Chemical Inc.).

[0047] From the viewpoint of the storage stability, abrasion resistance, solvent resistance, and adhesion of the pretreatment composition, the oxazoline group-containing compound is preferably a polyoxazoline compound having two or more oxazoline groups in one molecule.

[0048] Commercially available oxazoline group-containing compounds include, for example, the "Epocross WS series" such as "Epocross WS-300," "Epocross WS-500," and "Epocross WS-700" (all manufactured by Nippon Shokubai Co., Ltd., water-soluble types); and the "Epocross K series" such as Epocross K-2010E and Epocross K-2020E (trade names, emulsion types, manufactured by Nippon Shokubai Co., Ltd.).

[0049] The content of the crosslinking agent is 0.1% by mass or more and less than 4.0% by mass, preferably 0.2 to 3.5% by mass, more preferably 0.4 to 3.0% by mass, and even more preferably 0.6 to 2.7% by mass, based on the total mass of the pretreatment composition. A content of 0.1% by mass or more tends to provide effective adhesion. Furthermore, a content of 4.0% by mass or less tends to provide excellent storage stability for the pretreatment composition and excellent reduction of traces on printed materials.

[0050] [water] The pretreatment composition contains water. The water may be pure water such as ion-exchanged water, ultrafiltered water, reverse osmosis water, or distilled water, or ultrapure water. The water content is not particularly limited and may be determined as needed. However, to adjust the weight solids content in the pretreatment composition to a suitable range, the water content is preferably 70 to 96% by mass, more preferably 75 to 94% by mass, and particularly preferably 80 to 93% by mass, based on the total mass (100% by mass) of the pretreatment composition.

[0051] When the total mass of the cationic polymer is A and the total mass of the resin particles is B, the value calculated by A / B is in the range of 0.8 to 3.7, and preferably in the range of 0.9 to 3.6.

[0052] In addition to the above components, the pretreatment composition may further contain additives such as a water-soluble organic solvent, a surface tension adjuster, an antifungal agent, a preservative, a pH adjuster, a chelating agent, a rust inhibitor, a water-soluble ultraviolet absorber, an antioxidant, and a sizing agent.

[0053] [Water-soluble organic solvent] Examples of the water-soluble organic solvent include glycol-based solvents, polyhydric alcohols, and polyhydric alcohol alkyl ethers. Examples of glycol-based solvents include glycerin, polyglycerin (#310, #750, #800), diglycerin, triglycerin, tetraglycerin, pentaglycerin, hexaglycerin, heptaglycerin, octaglycerin, nonaglycerin, decaglycerin, undecaglycerin, dodecaglycerin, tridecaglycerin, and tetradecaglycerin. Examples of polyhydric alcohols include C2-C6 polyhydric alcohols having 2 to 3 alcoholic hydroxyl groups, di- or tri-C2-C3 alkylene glycols, and poly-C2-C3 alkylene glycols (preferably liquid polyalkylene glycols) having 4 or more repeating units and a molecular weight of approximately 20,000 or less. Specific examples of polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, 1,3-propanediol, 1,2-butanediol, thiodiglycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 3-methyl-1,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, trimethylolpropane, 1,3-pentanediol, 1,5-pentanediol, etc. Examples of polyhydric alcohol alkyl ethers include alkylene glycol monoalkyl ethers, dialkylene glycol monoalkyl ethers, trialkylene glycol monoalkyl ethers, etc.Specific examples include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoisobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monobutyl ether, etc. Also included are triethylene glycol monobutyl ether, etc. For convenience, compounds that dissolve in water and act as wetting agents are also included in the water-soluble organic solvent. Examples of such compounds include urea, ethylene urea, and sugars. The water-soluble organic solvents may be used alone or in combination of two or more.

[0054] The water-soluble organic solvent preferably contains at least one selected from glycerin, diethylene glycol, triethylene glycol, propylene glycol, 1,2-hexanediol, 1,6-hexanediol, 1,5-pentanediol, and diethylene glycol monobutyl ether.

[0055] The content of the water-soluble organic solvent is usually 0.5 to 20% by mass, preferably 1 to 15% by mass, and more preferably 2 to 10% by mass, based on the total mass of the pretreatment composition. By keeping the content within this range, the whiteness of the base and the amount of strike-through tend to be improved, and the storage stability of the pretreatment composition is excellent.

[0056] [Surface tension adjuster] The type of the surface tension modifier is not particularly limited, but a surfactant selected from, for example, acetylene glycol and polyalkylene glycol is preferred. The inclusion of a surfactant suppresses an increase in the viscosity of the pretreatment composition, suppresses aggregation of components, and improves storage stability. Of the above, pretreatment compositions containing at least a polyalkylene glycol as a surfactant tend to further improve the whiteness of the substrate and the strike-through.

[0057] Preferred acetylene glycol surfactants include surfactants selected from 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,4-dimethyl-5-decyne-4-ol, and 2,4-dimethyl-5-decyne-4-ol, or alkylene oxide adducts thereof. Examples of alkylene oxides include those selected from C2-C4 linear, branched, and cyclic alkylene oxides. Among these, linear or branched alkylene oxides are preferred. Examples of such surfactants include the Surfynol series (104, 420, 440, 465, 61, etc.) and the Olfine series (E1004, E1010, etc.) manufactured by Nissin Chemical Industry Co., Ltd.

[0058] The polyalkylene glycol surfactant is preferably selected from the group consisting of polyoxyethylene alkyl ethers, fatty acid ethylene oxide adducts, higher alkylamine ethylene oxide adducts, and polyoxy C2-C4 alkylene glycols, and among these, polyoxy C2-C4 alkylene glycols are preferred.

[0059] Examples of polyoxyethylene alkyl ethers include polyoxyalkylene branched decyl ethers, polyoxyalkylene tridecyl ethers, polyoxyethylene isodecyl ethers, and polyoxyalkylene lauryl ethers. Commercially available examples include Noigen XL-40, 50, 60, 70, 80, 100, 140, and 160, and Noigen TDS-30, 50, 70, 80, 90, 100, and 120, manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Examples of fatty acid ethylene oxide adducts include ethylene oxide stearic acid adducts and polyethylene glycol laurate esters. Commercially available examples include Emanon 1112, 3199V, 3299V, 3299VR, and 3201M-V, manufactured by Kao Corporation. Examples of commercially available products of higher alkylamine ethylene oxide adducts include Amite 102, 105, 105A, 302, and 320 manufactured by Kao Corporation. Examples of commercially available polyoxy C2-C4 alkylene glycols include Emulgen PP-290 (a 160 / 30 copolymer of polyethylene glycol / polypropylene glycol) manufactured by Kao Corporation; Newpol PE-61, PE-62, PE-64, PE-68, PE-71, PE-74, PE-75, PE-78, and PE-108 (polyoxyethylene polyoxypropylene block polymers) manufactured by Sanyo Chemical Industries, Ltd.; and Epan 410, 420, 450, 485, 680, 710, 720, 740, 750, 785, U-103, U-105, and U-108 (polyoxyethylene polyoxypropylene glycols with a weight-average molecular weight of polypropylene glycol of about 950 to 4000 and a polyoxyethylene content of about 5 to 95%) manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. The polyoxy C2-C4 alkylene glycol is preferably a polyoxy C2-C3 alkylene glycol, more preferably a polyoxyethylene polyoxypropylene glycol. In addition, the number of oxy C2 alkylene groups in the total number of oxy C2-C4 alkylene groups in the polyoxy C2-C4 alkylene glycol is usually less than 50%, preferably 15 to 45%, more preferably 20 to 40%.For example, when the total number of bonds of oxy C2 alkylene groups, oxy C3 alkylene groups, and oxy C4 alkylene groups is 10, the number of bonds of oxy alkylene groups is less than 5. The numbers of bonds of oxy C2-C4 alkylene groups are all average values. Furthermore, when a polyoxy C3-C4 alkylene group is the hydrophobic group and a polyoxy C2 alkylene group is the hydrophilic group in a polyoxyalkylene glycol, the weight-average molecular weight of the hydrophobic group is typically 2250 to 4000, preferably 2750 to 3600. An example of a polyoxyalkylene glycol that satisfies both the content of oxy C2 alkylene groups and the weight-average molecular weight of the hydrophobic group is Epane U-103. By including such a surfactant in a pretreatment composition containing a cationic polymer, good storage stability can be achieved.

[0060] The content of the surfactant is usually 0.05 to 5%, preferably 0.05 to 3%, more preferably 0.05 to 1%, and even more preferably 0.1 to 0.5%, based on the total mass of the pretreatment composition. This content tends to improve the washing fastness and abrasion resistance of the printed fiber. Furthermore, the storage stability of the pretreatment composition also tends to improve.

[0061] Specific examples of the antifungal agent include sodium dehydroacetate, sodium benzoate, sodium pyridinethione-1-oxide, p-hydroxybenzoic acid ethyl ester, 1,2-benzisothiazolin-3-one and salts thereof.

[0062] Examples of the preservatives include organic sulfur compounds, organic nitrogen sulfur compounds, organic halogen compounds, haloaryl sulfone compounds, iodopropargyl compounds, N-haloalkylthio compounds, nitrile compounds, pyridine compounds, 8-oxyquinolines, benzothiazole compounds, isothiazolinone compounds, dithiols, pyridine oxide compounds, nitropropane compounds, organic tin compounds, phenol compounds, quaternary ammonium salt compounds, triazine compounds, thiazine compounds, anilides, adamantane compounds, dithiocarbamates, brominated indanone compounds, benzyl bromoacetate compounds, and inorganic salt compounds. Specific examples of organic halogen compounds include sodium pentachlorophenol. Specific examples of pyridine oxide compounds include sodium 2-pyridinethiol-1-oxide. Specific examples of isothiazoline compounds include 1,2-benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one magnesium chloride, 5-chloro-2-methyl-4-isothiazolin-3-one calcium chloride, 2-methyl-4-isothiazolin-3-one calcium chloride, etc. Specific examples of other antiseptic and fungicides include sodium acetate anhydride, sodium sorbate, sodium benzoate, and Proxel (trade name) manufactured by Arch Chemicals. RTM GXL(S), Proxel RTM Examples include XL-2(S).

[0063] Any substance can be used as the pH adjuster as long as it can control the pH of the ink within a range of, for example, 3.0 to 9.0 without adversely affecting the prepared pretreatment composition. Examples of pH adjusters include alkali metal hydroxides, alkaline earth metal hydroxides, aliphatic amine compounds, and alcohol amine compounds. Examples of alkali metal hydroxides include lithium hydroxide, sodium hydroxide, and potassium hydroxide. Examples of alkaline earth metal hydroxides include beryllium hydroxide, magnesium hydroxide, calcium hydroxide, and strontium hydroxide. Among these, alkaline earth metal hydroxides are preferred, with lithium hydroxide and sodium hydroxide being more preferred. Examples of aliphatic amine compounds include ammonia, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, and triethylamine, with ammonia or triethylamine being preferred. Examples of the alcoholamine compound include monoethanolamine, diethanolamine, triethanolamine, monopropanolamine, dipropanolamine, tripropanolamine, methylethanolamine, dimethylethanolamine, diethylethanolamine, and N-methyldiethanolamine, but tertiary amines are preferred, and triethanolamine is more preferred. Other specific examples include alkali metal carbonates such as lithium carbonate, sodium carbonate, sodium bicarbonate, and potassium carbonate; alkali metal salts of organic acids such as sodium silicate and potassium acetate; and phosphates such as disodium phosphate.

[0064] Specific examples of the chelating agent include disodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uracildiacetate, and the like.

[0065] Specific examples of the rust inhibitor include acid sulfite, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.

[0066] Examples of the water-soluble ultraviolet absorber include sulfonated benzophenone compounds, benzotriazole compounds, salicylic acid compounds, cinnamic acid compounds, and triazine compounds.

[0067] As the antioxidant, for example, various organic and metal complex anti-fading agents can be used, and specific examples of the organic anti-fading agents include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, and heterocycles.

[0068] Examples of the sizing agent include starches such as corn and wheat starches; cellulose compounds such as carboxymethylcellulose and hydroxymethylcellulose; polysaccharides such as sodium alginate, gum arabic, locust bean gum, trang gum, guar gum, and tamarind seed; proteins such as gelatin and casein; natural water-soluble polymers such as tannin and lignin; and synthetic water-soluble polymer compounds containing polyvinyl alcohol, polyethylene oxide, acrylic acid, maleic anhydride, etc. The content of the sizing agent is usually about 0 to 20% of the total mass of the pretreatment composition.

[0069] [Static surface tension of pretreatment composition] The static surface tension of the pretreatment composition at 25°C is preferably 36 to 60 mN / m, more preferably 37 to 58 mN / m, even more preferably 38 to 56 mN / m, and particularly preferably 38 to 54 mN / m, from the viewpoint of being able to exhibit sufficient wettability to various fabrics.

[0070] From the viewpoint of preventing bleeding of printed matter, the static surface tension of the pretreatment composition at 25°C is preferably equal to or greater than the static surface tension of the aqueous ink composition described below. By making the static surface tension of the pretreatment composition greater than the static surface tension of the aqueous ink composition, the amount of surfactant oriented on the surface of the pretreatment layer formed by applying the pretreatment composition to the fabric can be reduced, and the surface energy of the pretreatment layer is not excessively reduced, resulting in suitable wettability for the aqueous ink composition printed later, and enabling the production of high-quality printed matter with no bleeding and excellent dot roundness.

[0071] The static surface tension of the pretreatment composition can be measured, for example, by a platinum plate method using a surface tensiometer (CBVPZ manufactured by Kyowa Interface Science Co., Ltd.) in an environment of 25°C.

[0072] [Dynamic surface tension of pretreatment composition] The pretreatment composition preferably has a dynamic surface tension at 25°C of 50 mN / m or more and 70 mN / m or less, more preferably 52 mN / m or more and 65 mN / m or less, and particularly preferably 53 mN / m or more and 63 mN / m or less.

[0073] [Viscosity of pretreatment composition] The viscosity of the pretreatment composition at 25°C is preferably 0.5 to 4.0 mPa·s, more preferably 0.7 to 3.5 mPa·s, and particularly preferably 0.8 to 3.0 mPa·s. A pretreatment composition that satisfies the above viscosity range can be applied evenly regardless of the application method or type of fabric, and can suppress uneven dot shapes and image non-uniformity. Furthermore, excellent printed matter can be obtained in terms of wetting the fabric and suppressing unevenness during drying.

[0074] The viscosity of the pretreatment composition can be measured using, for example, an E-type viscometer (TVE25L type viscometer manufactured by Toki Sangyo Co., Ltd.).

[0075] [pH of pretreatment composition] The pH of the pretreatment composition at 25° C. is preferably 6.5 to 10.0, more preferably 6.8 to 9.5, and particularly preferably 7.0 to 9.0. A pretreatment composition falling within the above pH range exhibits excellent storage stability, particularly when stored at high temperatures of 50 to 60° C. Furthermore, it is possible to prevent fabric embrittlement, and to obtain printed materials with excellent color development and minimal color bleeding or uneven coloring.

[0076] The pH of the pretreatment composition can be measured by known methods, for example, using a Horiba, Ltd., benchtop pH meter F-72 with a standard ToupH electrode or a sleeve ToupH electrode.

[0077] [Method for preparing pretreatment composition] The pretreatment composition according to this embodiment can be prepared, for example, by adding water, a cationic polymer, a crosslinking agent, resin particles, and, if necessary, the above-mentioned preparative agents, stirring and mixing the mixture, and then filtering the mixture if necessary. However, the method for preparing the pretreatment composition of the present invention is not limited to the above.

[0078] [Ink set] The present invention also includes an ink set containing the above pretreatment composition and ink. The ink is preferably a water-based ink composition containing a pigment, a polymer dispersant, a urethane resin, a water-soluble organic solvent, a surfactant, and water.

[0079] The ink set according to this embodiment includes the above-described pretreatment composition, and therefore can obtain images with high whiteness and high hiding power, and can also improve color development, rub fastness, and wash fastness.

[0080] The ink set is preferably a combination of one or more water-based ink compositions and one or more of the above-described pretreatment compositions, and is used in the form of an ink set.

[0081] The water-based ink composition will now be described in detail.

[0082] [Pigment] The pigment is not particularly limited, and any known pigment can be used, including inorganic pigments, organic pigments, and extender pigments.

[0083] Examples of the inorganic pigment include carbon black, metal oxides, hydroxides, sulfides, ferrocyanides, metal chlorides, etc. Among these, carbon black is preferred as a black pigment. There are several types of carbon black, including, for example, thermal black and acetylene black obtained by pyrolysis; and oil furnace black, gas furnace black, lamp black, gas black, and channel black obtained by incomplete combustion.

[0084] Of the above, preferred carbon blacks include acetylene black, oil furnace black, gas furnace black, lamp black, and channel black. Specific examples of carbon black include Raven 760 ULTRA, Raven 780 ULTRA, Raven 790 ULTRA, Raven 1060 ULTRA, Raven 1080 ULTRA, Raven 1170, Raven 1190 ULTRA II, Raven 1200, Raven 1250, Raven 1255, Raven 1500, Raven 2000, Raven 2500 ULTRA, Raven 3500, Raven 5000 ULTRA II, Raven 5250, Raven 5750, and Raven 7000 (all manufactured by Columbia Carbon); Monarch 700, Monarch 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, Monarch 1400, Regal 1330R, Regal 1400R, Regal 1660R, and Mogul L (all manufactured by Cabot Corporation); Color Black FW1, Color Black FW2, Color Black FW2V, Color Black FW200, Color Black S150, Color Black S160, Color Black S170, Printex 35, Printex U, Printex V, Printex 140U, Printex 140V, SpecIal Black 4, SpecIal Black 4A, SpecIal Black 5, Special Black 6 (all manufactured by Degussa); MA7, MA8, MA100, MA600, MCF-88, No. 25, No. 33, No. 40, No. 47, No. 52, No. 900, No. 2300 (all manufactured by Mitsubishi Chemical Corporation); and the like.

[0085] Furthermore, it is preferable to use a metal oxide as the white pigment. Examples of metal oxides include zinc oxide, titanium oxide, and zirconia oxide, with titanium oxide being preferred. Examples of titanium oxide include rutile and anatase types. Titanium oxide may be used as is in the form of powder, or may be surface-treated with silicon dioxide, aluminum oxide, zirconia oxide, zinc oxide, or an organic substance having a hydroxyl group. Of these, surface-treated titanium oxide is preferred. Specific examples of titanium oxide include DUAWHITE TCR-52, TITONE R-32, TITONE R-7E, TITONE R-21, TITONE R-62N, and TITONE R-42 (all manufactured by Sakai Chemical Industry Co., Ltd.); TIPAQUE CR-50, TIPAQUE CR-50-2, TIPAQUE CR-58, TIPAQUE CR-60, TIPAQUE CR-80, and TIPAQUE CR-90 (all manufactured by Ishihara Sangyo Kaisha, Ltd.); TITANIX JA-600A and TITANIX JR-605 (all manufactured by Teika Corporation); and ST-455, ST-455WB, ST-457SA, and ST-457EC (all manufactured by Titanium Kogyo Co., Ltd.).

[0086] Examples of the organic pigment include azo pigments having at least one azo group in the molecule, phthalocyanine pigments, quinacridone pigments, isoindolinone pigments, dioxazine pigments, perylene pigments, perinone pigments, thioindigo pigments, anthraquinone pigments, and quinophthalone pigments. Specific examples of organic pigments include yellow pigments such as CI Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 24, 55, 73, 74, 75, 83, 93, 94, 95, 97, 98, 108, 114, 128, 129, 138, 139, 150, 151, 154, 155, 180, 185, 193, 199, and 202; and CI Pigment Red Red pigments such as 5, 7, 12, 48, 48:1, 57, 88, 112, 122, 123, 146, 149, 166, 168, 177, 178, 179, 184, 185, 202, 206, 207, 254, 255, 257, 260, 264, and 272; blue pigments such as CI Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 22, 25, 60, 66, and 80; violet pigments such as CI Pigment Violet 19, 23, 29, 37, 38, and 50; orange to brown pigments such as CI Pigment Orange 13, 16, 36, 34, 43, 68, 69, 71, and 73; and CI Pigment Green pigments such as Green 7, 36, and 54; black pigments such as CI Pigment Black 1; and the like.

[0087] Examples of the extender pigment include silica, calcium carbonate, talc, clay, barium sulfate, white carbon, etc. These extender pigments may be used alone, but are usually used in combination with inorganic or organic pigments.

[0088] A single pigment is usually used as the pigment. However, two or more pigments may be used in combination if necessary. Examples include a combination of an organic pigment and an extender pigment, or an organic pigment and an inorganic pigment. To improve flowability, an extender pigment may be used in addition to an organic pigment and an inorganic pigment. Furthermore, to adjust the hue of a dyed product, two or more pigments selected from inorganic and organic pigments may be used in combination. The hue adjustment here is performed for the purposes of obtaining a dyed product with a different shade, widening the color gamut of the dye, etc. For such purposes, several organic pigments may be used in combination to adjust the desired hue.

[0089] The content of the pigment is preferably 1.5 to 15.0% by mass, more preferably 2.0 to 14.0% by mass, and even more preferably 2.5 to 13.0% by mass, relative to the total mass (100% by mass) of the water-based ink composition.

[0090] [Polymer dispersant] A common method for stabilizing a pigment dispersion in an aqueous ink composition is to use a dispersant such as a resin to stabilize the pigment dispersion through entropy, ionic repulsion, steric repulsion, or the like. The dispersant has a hydrophilic portion and a hydrophobic portion, and the hydrophobic portion is believed to have the property of adsorbing to the pigment surface, while the hydrophilic portion disperses the pigment in the aqueous ink composition. Furthermore, depending on the state of adsorption to the pigment surface, it is also possible to dissolve the pigment in the aqueous ink composition. A dispersant having such properties can be used as the polymer dispersant.

[0091] The polymer dispersant is preferably a polymer composed of at least two types of monomers selected from the group consisting of Monomer A, Monomer B, and Monomer C represented by the following formula (1), and more preferably at least one type each of Monomer A, Monomer B, and Monomer C is selected. Monomer A: A monomer represented by the following formula (1), in which R is a hydrogen atom. Monomer B: A monomer represented by the following formula (1), in which R is a C1-C6 alkyl group. Preferably, the monomer is one in which R is an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a cyclopentyl group, or a cyclohexyl group, more preferably, one in which R is an n-butyl group, an isobutyl group, or a cyclohexyl group. Monomer C: A monomer in which R in the following formula (1) is an aryl group or an aryl C1-C4 alkyl group, preferably a monomer in which R is an aryl group, more preferably a monomer in which R is a benzyl group.

[0092] [ka]

[0093] The polymer dispersant may be any of a random copolymer, an alternating copolymer, a block copolymer, and a graft copolymer of these monomers.

[0094] The mass average molecular weight of the polymer dispersant is usually 10,000 to 60,000, preferably 10,000 to 40,000, and more preferably 10,000 to 30,000. When the mass average molecular weight is within this range, the stability of the pigment dispersion liquid is good.

[0095] The acid value of the polymer dispersant, expressed in mgKOH / g, is usually 50 to 300, preferably 90 to 200, and more preferably 100 to 150. If the acid value is too small, the solubility of the polymer dispersant in water or a water-based ink composition may decrease, while if the acid value is too large, the color development may decrease.

[0096] An example of a polymer dispersant is Seiko PMC's Hi-Loss X VS-1202 (a random polymer consisting of methyl methacrylate, butyl methacrylate and methacrylic acid, with an acid value of 140 mg KOH / g and a mass average molecular weight of 11,000).

[0097] The polymer dispersant may be used after neutralizing its acid value as needed. The degree of neutralization is 100% when the polymer dispersant is neutralized with the theoretical equivalent of its acid value. The degree of neutralization of the polymer dispersant in the aqueous ink composition is usually about 50 to 200%, preferably about 80 to 150%, and more preferably about 100 to 120%.

[0098] Examples of the neutralizing agent used to neutralize the polymer dispersant include inorganic bases such as alkali metal hydroxides, alkaline earth metal hydroxides, and ammonia, and organic bases such as aliphatic amine compounds and alkanolamine compounds.

[0099] Examples of the alkali metal hydroxides include lithium hydroxide, sodium hydroxide, and potassium hydroxide. Examples of the hydroxides of alkaline earth metals include beryllium hydroxide, magnesium hydroxide, calcium hydroxide, and strontium hydroxide. Among inorganic bases, alkali metal hydroxides and ammonia are preferred, with lithium hydroxide, sodium hydroxide, and ammonia being particularly preferred.

[0100] Examples of the alkanolamine compound include mono-, di-, or tri-C1-C3 alkanolamine compounds such as monoethanolamine, diethanolamine, triethanolamine, monopropanolamine, dipropanolamine, tripropanolamine, methylethanolamine, dimethylethanolamine, and N-methyldiethanolamine. Among these, tertiary amines are preferred, and triethanolamine is particularly preferred.

[0101] Examples of the aliphatic amine compound include mono-, di-, or tri-C1-C3 amine compounds such as monomethylamine, dimethylamine, trimethylamine, monoethylamine, dimethylamine, trimethylamine, etc. Among these, triethylamine is preferred.

[0102] These neutralizing agents may be used alone or in combination of two or more.

[0103] [Monomer A] Monomer A is a monomer in which R in the above formula (1) is a hydrogen atom, that is, methacrylic acid.

[0104] [Monomer B] Monomer B is a monomer in which R in the above formula (1) is a C1-C6 alkyl group. Specific examples of the monomer B include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-pentyl methacrylate, n-hexyl methacrylate, cyclopentyl methacrylate, and cyclohexyl methacrylate.

[0105] [Monomer C] Monomer C is a monomer in which R in the above formula (1) is an aryl group or an aryl C1-C4 alkyl group. The aryl is preferably a C6-C10 aryl group, and more preferably a phenyl group or a naphthyl group. Examples of the aryl C1-C4 alkyl group include phenyl C1-C4 alkyl groups in which the alkyl moiety is linear or branched, preferably linear, such as phenylmethyl, phenylethyl, phenylpropyl, and phenylbutyl; and naphthyl C1-C4 alkyl groups in which the alkyl moiety is linear or branched, preferably linear, such as naphthylmethyl, naphthylethyl, naphthylpropyl, and naphthylbutyl; and among these, phenyl C1-C4 alkyl groups are preferred. Specific examples of the monomer C include phenyl methacrylate, benzyl methacrylate, and phenethyl methacrylate.

[0106] The content of the polymer dispersant is usually 0.1 to 15.0% by mass, preferably 0.1 to 9.0% by mass, and more preferably 0.2 to 6.0% by mass, relative to the total mass (100% by mass) of the water-based ink composition.

[0107] [Urethane resin] The urethane resin is a resin having a urethane bond in the molecule. From the viewpoint of storage stability of the ink, the urethane resin is preferably an anionic urethane resin having an acidic group such as a carboxy group, a sulfo group, or a hydroxyl group.

[0108] Examples of the urethane resin include polyether-type urethane resins containing ether bonds in the main chain in addition to urethane bonds, polyester-type urethane resins containing ester bonds in the main chain, and polycarbonate-type urethane resins containing carbonate bonds in the main chain. These urethane resins can be used in combination with multiple types. Among these, from the viewpoint of improving friction resistance, it is preferable to include polyester-type urethane resins and polycarbonate-type urethane resins, and it is more preferable to use a combination of polyester-type urethane resins and polycarbonate-type urethane resins.

[0109] The polyurethane resin may be either a synthetically prepared one or a commercially available product, most of which are emulsions with a solid content of 30 to 60% by mass. Commercially available urethane resin emulsions include, for example, Permarin UA-150, 200, 310, 368, 3945, U-coat UX-320, 390 (all manufactured by Sanyo Chemical Industry Co., Ltd.); Hydran WLS-201, 202, 210, 213, 221, 230, 250, and HW-312B latex (all manufactured by DIC Corporation); Superflex 150, 170, 210, 470, 500M, and 740 (all manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.); ETERNACOLL UW-1005N, UW-1013D, UW-1501F, UW-1527F, and UW-5002 (all manufactured by Ube Industries, Ltd.); and Takelac. WS-4000, WS-5000, WS-5030, WS-5100, WS-5130, W-6061, W-6110, WS-5984 (all trade names manufactured by Mitsui Chemicals, Inc.); Among these, examples of polyester-type urethane resins include Superflex 210, 500M, and 740; Takelac WS-4000, WS-5000, WS-5030, WS-5130, and WS-5984; and examples of polycarbonate-type urethane resins include Permarin UA-310 and 3945; U-coat UX-320; Hydran WLS-210, 213, and 250; and Takelac W-6110.

[0110] When the urethane resin in the urethane resin emulsion has acidic groups such as carboxyl groups, sulfo groups, or hydroxyl groups, the acidic groups may be converted into alkali salts. For example, the acidic groups can be converted into alkali salts by adding a urethane resin having acidic groups to water and stirring to prepare an aqueous solution, and then adding an alkaline compound to adjust the pH to 6.0 to 12.0. Examples of alkaline compounds include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; and alkaline earth metal hydroxides such as beryllium hydroxide, magnesium hydroxide, calcium hydroxide, and strontium hydroxide. One type of alkaline compound may be used alone, or two or more types may be used in combination.

[0111] [Water-soluble organic solvent] Examples of water-soluble organic solvents that can be contained in the aqueous ink composition include polyhydric alcohols, ethers such as polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, propylene carbonate, ethylene carbonate, etc. These may be used alone or in combination of two or more.

[0112] Examples of polyhydric alcohols that can be contained in the aqueous ink composition include ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, and 3-methyl-1,3-butanediol (isoprene glycol). , 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, and petriol.

[0113] Examples of polyhydric alcohol alkyl ethers that may be contained in the aqueous ink composition include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol monopropyl ether.

[0114] Examples of polyhydric alcohol aryl ethers that can be contained in the water-based ink composition include ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.

[0115] Examples of nitrogen-containing heterocyclic compounds that can be contained in the water-based ink composition include 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, and γ-butyrolactone.

[0116] Examples of amides that can be contained in the water-based ink composition include formamide, N-methylformamide, N,N-dimethylformamide, 3-methoxy-N,N-dimethylpropionamide, and 3-butoxy-N,N-dimethylpropionamide.

[0117] The water-soluble organic solvent that can be contained in the aqueous ink composition may be one kind or a combination of two or more kinds. Among these, diethylene glycol, 1,2-propanediol, 1,3-propanediol, triethylene glycol, 3-methyl-1,3-butanediol, 1,6-hexanediol, glycerin, diethylene glycol monobutyl ether, and propylene glycol monopropyl ether are preferred, and 1,2-propanediol, 1,3-propanediol, 3-methyl-1,3-butanediol, 1,6-hexanediol, glycerin, and propylene glycol monopropyl ether are more preferred.

[0118] From the viewpoint of the drying properties and ejection stability of the white ink, the water-soluble organic solvent that can be contained in the aqueous ink composition includes a polyhydric alcohol having a boiling point of 250°C or higher and a polyhydric alcohol having a boiling point of 210°C or lower, and the content of the polyhydric alcohol having a boiling point of 250°C or higher is preferably 20% or less, and more preferably 18% or less, of the total amount of ink.

[0119] Examples of the polyhydric alcohol having a boiling point of 250° C. or higher include glycerin (boiling point: 290° C.).

[0120] Examples of the polyhydric alcohol having a boiling point of 210° C. or less include 3-methyl-1,3-butanediol (boiling point: 203° C.).

[0121] The content of the water-soluble organic solvent that can be contained in the water-based ink composition is preferably 10 to 50 mass %, more preferably 14 to 45 mass %, and even more preferably 16 to 35 mass %, relative to the total mass (100 mass %) of the water-based ink composition. When the content of the water-soluble organic solvent that can be contained in the water-based ink composition is within the above range, the water-based ink composition tends to be excellent in terms of reducing ejection defects.

[0122] [Surfactants] The surfactant that can be contained in the water-based ink composition is not particularly limited, but examples thereof include known surfactants such as anionic, cationic, nonionic, amphoteric, silicone, and fluorine-based surfactants. Examples of anionic surfactants include alkyl sulfonates, alkyl carboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, N-acylamino acids and their salts, N-acylmethyltaurines, alkyl sulfates, polyoxyalkyl ether sulfates, alkyl sulfates, polyoxyethylene alkyl ether phosphates, rosin acid soaps, castor oil sulfates, lauryl alcohol sulfates, alkylphenol phosphates, alkyl phosphates, alkylaryl sulfonates, diethyl sulfosuccinates, diethylhexyl sulfosuccinates, dioctyl sulfosuccinates, etc. Specific examples of commercially available products include Hitenol LA-10, LA-12, LA-16, Neohitenol ECL-30S, and ECL-45, all manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. Examples of cationic surfactants include 2-vinylpyridine derivatives and poly(4-vinylpyridine) derivatives. Examples of nonionic surfactants include ether surfactants such as polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, and polyoxyethylene alkyl ether; polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, and sorbitan sesquioleate. ester-based surfactants such as polyoxyethylene monooleate and polyoxyethylene stearate; acetylene glycol (alcohol)-based surfactants such as 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol and 3,5-dimethyl-1-hexyn-3-ol; Surfynol 104, 105, 82, 420, 440, 465, Olfin EXP-4001, and the like, manufactured by Nissin Chemical Co., Ltd.; and polyglycol ether-based surfactants (for example, Tergitol 15-S-7, manufactured by SIGMA-ALDRICH). Examples of amphoteric surfactants include lauryl dimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine, coconut oil fatty acid amidopropyl dimethylaminoacetic acid betaine, polyoctyl polyaminoethyl glycine, and imidazoline derivatives. Examples of silicone surfactants include polyether-modified siloxane, polyether-modified polydimethylsiloxane, etc. Specific examples of commercially available products include BYK-347 (polyether-modified siloxane), BYK-345, and BYK-348 (polyether-modified polydimethylsiloxane), all manufactured by BYK-Chemie. Examples of fluorine-based surfactants include perfluoroalkyl sulfonic acid compounds, perfluoroalkyl carboxylic acid compounds, perfluoroalkyl phosphate ester compounds, perfluoroalkyl ethylene oxide adducts, and polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups on the side chains. Specific examples of commercially available products include Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, Capstone FS-30, FS-31 (manufactured by DuPont); PF-151N, PF-154N (manufactured by Omnova).

[0123] [water] Examples of water that can be contained in the aqueous ink composition include those exemplified in the pretreatment composition. The water content is not particularly limited and can be determined as needed. However, to adjust the viscosity of the aqueous ink composition to a suitable range, the water content is preferably 20 to 80% by mass relative to the total mass (100% by mass) of the aqueous ink composition. Furthermore, although not limited thereto, the water content is preferably 40 to 80% by mass, more preferably 45 to 75% by mass, and even more preferably 50 to 70% by mass.

[0124] The water-based ink composition may further contain additives.

[0125] Examples of the additives include preservatives, chelating agents, anti-rust agents, water-soluble ultraviolet absorbers, water-soluble polymer compounds, viscosity adjusters, anti-fading agents, and antioxidants.

[0126] Examples of preservatives in the additives include organic sulfur compounds, organic nitrogen sulfur compounds, organic halogen compounds, haloarylsulfone compounds, iodopropargyl compounds, N-haloalkylthio compounds, nitrile compounds, pyridine compounds, 8-oxyquinolines, benzothiazole compounds, isothiazolinone compounds, dithiols, pyridine oxide compounds, nitropropane compounds, organic tin compounds, phenol compounds, quaternary ammonium salt compounds, triazine compounds, thiazine compounds, anilides, adamantane compounds, dithiocarbamates, brominated indanone compounds, benzyl bromoacetate compounds, and inorganic salt compounds. Specific examples of organic halogen compounds include sodium pentachlorophenol, specific examples of pyridine oxide compounds include sodium 2-pyridinethiol-1-oxide, and specific examples of isothiazoline compounds include 1,2-benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one magnesium chloride, 5-chloro-2-methyl-4-isothiazolin-3-one calcium chloride, 2-methyl-4-isothiazolin-3-one calcium chloride, etc. Specific examples of other antiseptics and fungicides include sodium acetate anhydride, sodium sorbate, or sodium benzoate, manufactured by Arch Chemical Co., Ltd., under the trade name Proxel. RTM GXL(S) and Proxel RTM Examples include XL-2(S).

[0127] Specific examples of the chelating agent in the additive include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uracildiacetate, and the like.

[0128] Examples of the rust inhibitor in the additives include acid sulfite, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.

[0129] Examples of the water-soluble ultraviolet absorber in the additive include sulfonated benzophenone compounds, benzotriazole compounds, salicylic acid compounds, cinnamic acid compounds, and triazine compounds.

[0130] Examples of the water-soluble polymer compound in the additive include polyvinyl alcohol, cellulose derivatives, polyamines, and polyimines.

[0131] Examples of the viscosity adjuster in the additives include the water-soluble organic solvents and water-soluble polymer compounds described in the section on the water-based ink composition. Examples of the water-soluble polymer compounds include polyvinyl alcohol, cellulose derivatives, polyamines, and polyimines.

[0132] The anti-fading agent in the above additives is used for the purpose of improving the storage stability of images. As the anti-fading agent, for example, various organic and metal complex anti-fading agents can be used. Examples of organic anti-fading agents include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, and heterocycles. Examples of metal complex anti-fading agents include nickel complexes and zinc complexes.

[0133] The antioxidant in the additives may be, for example, various organic and metal complex anti-fading agents, such as hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, and heterocycles.

[0134] [Static surface tension of water-based ink composition] The static surface tension of the water-based ink composition at 25°C is preferably 30 to 45 mN / m, more preferably 32 to 42 mN / m, even more preferably 33 to 41 mN / m, and particularly preferably 35 to 40 mN / m, from the viewpoint of being able to exhibit sufficient wettability to various fabrics.

[0135] The static surface tension of the water-based ink composition can be measured, for example, by a platinum plate method using a surface tensiometer (CBVPZ manufactured by Kyowa Interface Science Co., Ltd.) in a 25°C environment.

[0136] [Viscosity of Water-Based Ink Composition] The viscosity of the water-based ink composition at 25° C. is preferably 2 to 20 mPa·s, and more preferably 3 to 18 mPa·s. Water-based ink compositions that satisfy the above viscosity range tend to exhibit good ejection response during high-speed printing.

[0137] [Method for preparing water-based ink composition] The water-based ink composition can be prepared, for example, by preparing an aqueous dispersion containing the above components and, if necessary, further adding additives such as a water-soluble organic solvent.

[0138] The substrate to which the pretreatment liquid is applied is not particularly limited, but is preferably a fabric. Among them, a fabric made of hydrophobic fibers is preferred, and a dark-colored fabric made of hydrophobic fibers is more preferred. The hydrophobic fiber refers to a fiber containing a hydrophobic resin. Specific examples of hydrophobic resins include polyester, nylon, triacetate, diacetate, polyamide, and other resins, as well as resins containing two or more of these resins. Fibers containing a hydrophobic resin in this specification include fibers made of the above resins and blends of these fibers with regenerated fibers such as rayon and natural fibers such as cotton, silk, and wool. Among these, fibers containing polyester resin (polyester fibers and blends containing polyester fibers) are preferred. Specific examples of fabrics, which are structures of fibers containing a hydrophobic resin, include satin, tropical, double pique, and microfiber.

[0139] The above-mentioned "dark colored fabric" refers to fabrics other than white. Specific examples include black, gray, navy blue, red, blue, green, and other fabrics. The lightness (L * ) using a spectrophotometer (e.g., X-rite exact (manufactured by X-rite)), * It is preferable that the fabric satisfies the range of 40>L * It is more preferable that the fabric satisfies the range of 30>L * It is more preferable that the fabric satisfies the range of 20>L * It is particularly preferable that the fabric satisfies the range.

[0140] The present invention also includes a printed matter in which the above-mentioned aqueous ink composition is printed on a dark-colored fabric made of the above-mentioned hydrophobic fibers that has been coated with the above-mentioned pretreatment composition.

[0141] [Inkjet printing method] The inkjet textile printing method (hereinafter also simply referred to as the textile printing method) may include, for example, a pretreatment step of applying the pretreatment composition to a dark-colored fabric made of hydrophobic fibers to form a pretreatment layer; a pretreatment drying step of drying the pretreatment composition adhered to the fabric after the pretreatment step; a recording step of applying, by an inkjet system, an aqueous ink composition containing a pigment, a polymer dispersant, a urethane resin, a water-soluble organic solvent, a surfactant, and water to at least a part of the area where the pretreatment layer adhered to the fabric has been formed, to form an image area; and a drying step of heating and drying the fabric to which the aqueous ink composition has been adhered.

[0142] [Pretreatment process] The pretreatment step refers to a step of applying a pretreatment composition to a fabric. The means for applying the pretreatment composition is not particularly limited, but for example, roller application, spray application, or inkjet application can be used. Among these, it is preferable to apply the pretreatment composition to the fabric in a non-contact manner, and more preferably by spray application or inkjet application. By applying the pretreatment composition in a non-contact manner, it is easier to control the amount of the pretreatment composition applied, which tends to further improve the image quality obtained.

[0143] The amount of the pretreatment composition applied per unit area of ​​the fabric is 0.020 g / cm 2 and exceeds 0.040 g / cm 2 The coating amount is preferably less than 0.023 to 0.038 g / cm. 2 and more preferably 0.024 to 0.035 g / cm 2 and particularly preferably 0.025 to 0.032 g / cm 2 is. The amount of pretreatment composition applied was 0.020 g / cm 2When polyester fibers (mesh fabrics used in sportswear, etc.), thin fibers, coarsely woven fibers, etc. are used, ink droplets ejected by the inkjet method tend to penetrate (penetrate) the opposite side of the fabric that is not printed, thereby making it possible to suppress ink strike-through, and when a base is laid with a white ink, the whiteness and hiding power tend to be improved. 2 By making the amount of the pretreatment composition less than 100%, it is possible to prevent "traces" of the pretreatment composition from remaining.

[0144] [First drying process] The first drying step refers to a step of heating and drying the fabric to which the pretreatment composition is attached. The heating method is not particularly limited, but examples thereof include hot air drying, heat pressing, atmospheric pressure steaming, high pressure steaming, and Thermofix. Examples of heat sources for heating include hot air, infrared rays, and microwaves.

[0145] [Recording process] The recording step is a step of ejecting the water-based ink composition from a head onto at least a portion of an area where a pretreatment layer has been formed on a fabric, thereby adhering the water-based ink composition to form an image area.

[0146] [Second drying process] The drying step refers to a step of ejecting the aqueous ink composition from a head and heating and drying the fabric to which the aqueous ink composition is attached. The heating method is not particularly limited, but examples thereof include hot air drying, heat pressing, atmospheric pressure steaming, high-pressure steaming, and Thermofix. Examples of heat sources for heating include hot air, infrared rays, and microwaves. By heating, the resin that may be contained in the pretreatment composition or the aqueous ink composition can be fused to the surface of the fabric, and the crosslinking reaction between the crosslinking agent and the resin can be promoted, and at the same time, water and the organic solvent can be evaporated. By performing the drying step, the obtained image tends to have better abrasion fastness and washing fastness.

[0147] In the second drying step, the surface of the fabric to which the aqueous ink composition has been applied may be pressurized either without or with pressure treatment. However, a non-contact heating method that does not apply pressure to the surface of the fabric to which the aqueous ink composition has been applied is preferred in the initial stage of the second drying step. Examples of non-contact heating methods include oven drying (methods that do not involve pressing, such as conveyor ovens and batch ovens). By including such a drying step, it is possible to reduce the penetration of the white ink into the fibers, thereby further improving whiteness and hiding power. The drying time in the non-contact heating method is preferably 20 seconds to 2 minutes, more preferably 25 seconds to 1 minute 30 seconds, and even more preferably 30 seconds to 1 minute. After the drying step using the non-contact heating method, it is preferable to perform a drying step using a contact heating method in which the surface of the fabric to which the aqueous ink composition has been applied is pressurized. The contact heating method is not particularly limited, but examples thereof include a heat press. By performing such a drying step, the abrasion fastness and washing fastness of the resulting image are further improved. The drying time by the contact heating method, which is carried out after the drying step by the non-contact heating method, is preferably 25 seconds to 3 minutes, more preferably 30 seconds to 2 minutes, and even more preferably 30 seconds to 1 minute 30 seconds.

[0148] The heat source for heating is not particularly limited, but examples thereof include infrared rays (lamp). The drying temperature may be any temperature sufficient to fuse the resins contained in the aqueous ink composition, promote the crosslinking reaction between the crosslinker and the resin, and evaporate water. When using dark-colored polyester fibers, including black, or blends containing polyester fibers, the drying temperature is preferably 130°C or lower, more preferably 120 to 130°C, from the viewpoint of preventing dye migration. By keeping the drying temperature within the above range, it is possible to suppress a decrease in whiteness due to dye migration and to improve rub fastness and washing fastness. When using hydrophobic fibers other than polyester (e.g., nylon, etc.), the drying temperature is preferably 140°C or higher, more preferably 150 to 190°C, even more preferably 150 to 180°C, and particularly preferably 150 to 170°C. By keeping the drying temperature within the above range, it is possible to improve rub fastness and washing fastness. Furthermore, by setting the temperature to 190°C or less, it is possible to prevent thermal deterioration of the components contained in the fiber and the pretreatment composition.

[0149] When only drying by the non-contact heating method is performed, the drying time is preferably 1 to 20 minutes, more preferably 1 to 16 minutes, even more preferably 1 to 12 minutes, and particularly preferably 1 to 8 minutes. When only drying by the contact heating method is performed, in the case of using dark colored polyester fibers including black, or blended fibers containing polyester fibers, the drying time is preferably 1 to 5 minutes, more preferably 1 to 4 minutes, even more preferably 1 to 3 minutes, and particularly preferably 1 to 2 minutes, from the viewpoint of preventing dye migration.

[0150] After the heating step, the fabric may be washed with water and dried. At this time, if necessary, a soaping treatment may be carried out, i.e., a treatment for washing off unfixed pigment with hot soapy water or the like.

[0151] The pretreatment composition of the present invention has high whiteness and hiding power when a base is applied to a dark-colored fabric made of hydrophobic fibers using a white ink, and also has excellent adhesion to the fabric, leaving little trace of the pretreatment, enabling high-quality white textile printing. In addition, it also has excellent storage stability. Because the whiteness and hiding power of the base can be increased, the color development of an image printed with color ink on the base can be improved, allowing for the production of a printed item having a high-quality color image. Furthermore, the printed item obtained using the pretreatment composition of the present invention also has excellent fastness properties, such as rub fastness and wash fastness. [Example]

[0152] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The pretreatment composition and the aqueous ink composition were prepared under stirring unless otherwise specified. The "water" used in the examples is ion-exchanged water.

[0153] Preparation Example 1: Preparation of water-based ink composition. The components shown in Table 1 below were mixed by thorough stirring, filtered through a mixed cellulose ester filter with a pore size of 5 μm, and then degassed using a vacuum pump to obtain test ink 1.

[0154] The descriptions in Table 1 below indicate the following: The numerical values ​​in Table 1 are in parts. Ink 1: Water-based ink composition prepared in Preparation Example 1 TF-5760 WHITE (D2B) (white pigment dispersion, solids content 60%, manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) Hydran WLS-210 (urethane resin emulsion, solids content 35%, manufactured by DIC Corporation) Olfin EXP-4001 (surfactant, manufactured by Nissin Chemical Industry Co., Ltd.) PROXEL GXL(S) (preservative, manufactured by Lonza Corporation) TEA: Triethanolamine manufactured by Junsei Chemical Co., Ltd.

[0155] [Table 1]

[0156] [Examples 1 to 17] The components shown in Table 2 below were mixed to make a total of 100 parts of each liquid, which was then filtered through a membrane filter with an average pore size of 3 μm to obtain example pretreatment compositions 1 to 17.

[0157] [Comparative Examples 1 to 8] The components shown in Table 3 below were mixed to make a total of 100 parts of each liquid, which was then filtered through a membrane filter with an average pore size of 3 μm to obtain comparative pretreatment compositions 1 to 8.

[0158] The abbreviations in Table 2 below represent the following: The numerical values ​​in Table 1 are in parts. [1. Cationic polymer] DK6804: Epihalohydrin-modified polyamine resin (Seiko PMC Corporation, weight-average molecular weight: 677) DK6850: Epihalohydrin-modified polyamine resin (Seiko PMC Corporation, weight-average molecular weight: 1703) DK6854: Epihalohydrin-modified polyamine resin (Seiko PMC Corporation, weight-average molecular weight: 5853) [2. Crosslinking Agent] Epocross WS-700: Oxazoline group-containing compound (Nippon Shokubai Co., Ltd., oxazoline group-containing polymer, solid content 25%) Meikanate FM-1: Blocked isocyanate group-containing compound (Meisei Chemical Industry Co., Ltd., cationic, blocked isocyanate group-containing polymer, solid content 30%) Meikanate ST: Blocked isocyanate group-containing compound (Meisei Chemical Industry Co., Ltd., cationic, blocked isocyanate group-containing polymer, solid content 30%) [3. Resin particles] Movinyl 6718: (Meth)acrylic resin copolymer: manufactured by Japan Coating Resin Co., Ltd., anionic acrylic resin emulsion, solid content 45% by mass Movinyl 6750: (meth)acrylic resin copolymer: manufactured by Japan Coating Resin Co., Ltd., anionic acrylic resin emulsion, solid content 50% by mass Movinyl 6751D: (meth)acrylic resin copolymer: manufactured by Japan Coating Resin Co., Ltd., anionic acrylic resin emulsion, solid content 45% by mass Movinyl 6960: (meth)acrylic resin copolymer (Japan Coating Resin Co., Ltd., anionic styrene / acrylic resin emulsion, solid content 45% by mass) Movinyl 6963: (meth)acrylic resin copolymer (Japan Coating Resin Co., Ltd., anionic styrene / acrylic resin emulsion, solid content 45% by mass) Movinyl 966A: (meth)acrylic resin copolymer (Japan Coating Resin Co., Ltd., anionic styrene / acrylic resin emulsion, solid content 45% by mass) Movinyl 3500: Polyvinyl resin polymer (Japan Coating Resins Co., Ltd., cationic vinyl acetate resin emulsion, solid content 50% by mass) Movinyl 6950: (meth)acrylic resin copolymer (Japan Coating Resin Co., Ltd., cationic acrylic resin emulsion, solid content 50% by mass) Movinyl 6951: (meth)acrylic resin copolymer (Japan Coating Resin Co., Ltd., cationic acrylic resin emulsion, solid content 45% by mass) Movinyl 7820: (meth)acrylic resin copolymer (Japan Coating Resin Co., Ltd., cationic acrylic resin emulsion, solid content 45% by mass) Superflex 500M: urethane resin polymer (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., nonionic urethane resin emulsion, solid content 45% by mass, glass transition temperature (Tg): -39°C) Superflex E4800: urethane resin polymer (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., nonionic urethane resin emulsion, solid content 40% by mass, glass transition temperature (Tg): -65°C) Meishield P-350K: Hydrocarbon resin polymer (Meisei Chemical Industry Co., Ltd., cationic hydrocarbon resin emulsion, solid content 30% by mass) POLON-MF-14EC: Silicone resin polymer (Shin-Etsu Chemical Co., Ltd., silicone resin emulsion, solid content 34% by mass)

[0159] [Recording method] [Pretreatment process] Using a commercially available spray bottle (Mitsugiron Co., Ltd., Fine Spray), each of the pretreatment compositions obtained above was applied in an amount of 0.025 g / cm. 2 Each solution was applied to an A4 size polyester fabric (dry T-shirt, black 00300-ACT (Glimmer)). Then, a tabletop automatic press (AF-65TEN manufactured by Asahi Textile Machinery Co., Ltd.) was used to apply the solution at a pressure of 1.0 N / cm. 2 The fabric was then dried by heating at 130°C for 60 seconds to obtain a pretreated fabric.

[0160] [Recording process] Ink 1 was filled into an industrial inkjet evaluation device (extended coating device EV2500: manufactured by Ricoh Co., Ltd.). Then, ink 1 was applied to a portion of the surface area of ​​each pretreated fabric obtained above in an amount of 17 mg / cm under the conditions of an ink droplet weight of 29 pL / dot, a head temperature of 25°C, a resolution of 1200 dpi, and two-overprinting. 2 After the ink 1 was applied, the ink was dried by heating at 130°C for 30 seconds in a non-contact manner using a tabletop automatic press (AF-65TEN manufactured by Asahi Textile Machinery Co., Ltd.), and then pressed under a pressure of 1.0 N / cm. 2 The resulting product was dried by heating at 130°C for 30 seconds three times to obtain a white printed product.

[0161] [Table 2]

[0162] [Table 3]

[0163] The pretreatment step and the recording step were each carried out at room temperature of 25° C. The hyphens in Table 3 indicate that the whiteness of the printed item was extremely low, and therefore the washing fastness was not evaluated.

[0164] In each of the examples and comparative examples, a printed matter was also prepared by subjecting the fabric to a pretreatment process without ink adhesion, and then subjecting the fabric to heat drying in the same manner as when ink was adhered.

[0165] [Whiteness] The L of the printed surface of the printed product obtained as above * The color values ​​were measured using a spectrophotometer (X-Rite Ci62, manufactured by X-Rite) under the measurement conditions of a light source of D65 and a viewing angle of 2°, in CIE / L. * a * b * In the color system, L * The measurement was carried out five times for each printed item, and the average value was used as the measurement result and evaluated according to the following evaluation criteria. The evaluation results are shown in Tables 2 and 3. (Evaluation criteria) A:L * Value is 80 or more B:L * Value is between 75 and 80 C:L * Value is 70 or more but less than 75 D:L * Value less than 70

[0166] [Washing fastness] The washing fastness of the ink 1 printed surface of the printed textile obtained as described above was determined by a washing fastness test. The washing fastness test was conducted three times in accordance with "AATCC61 2A" and evaluated according to the following evaluation criteria. The evaluation results are shown in Tables 2 and 3. (Evaluation criteria) A: The coating did not fall off even after three repeated tests. B: After three repeated tests, some of the coating fell off, but more than half remained. C: After two repeated tests, the coating fell off. D: The coating fell off after one test.

[0167] [Traces of pre-processing] Using a recorded material that had undergone the pretreatment process but not been printed with Ink 1, the pretreatment-coated portion of the recorded material (no ink attached) was visually compared with the non-coated portion (the fabric itself), and white residue from the pretreatment composition in the pretreatment-coated portion was confirmed. The evaluation results are shown in Tables 2 and 3. (Evaluation criteria) A: No marks left. B: There is still some residue left. C: There are a lot of traces.

[0168] As is clear from the results in Tables 2 and 3 above, the pretreatment compositions of the Examples have high whiteness and high washing fastness, and also have the ability to leave minimal traces of pretreatment. [Industrial Applicability]

[0169] The pretreatment composition of the present invention has good whiteness, hiding power, and washing fastness, and can produce excellent printed matter without any traces of pretreatment. Furthermore, the pretreatment composition has good storage stability, making it extremely useful as a pretreatment composition for a wide variety of fabrics.

Claims

1. A pretreatment composition comprising a cationic polymer having a weight-average molecular weight of 700 to 6000, resin particles, a crosslinking agent, and water, wherein the resin particles have a contact angle (ca1) of 84° or more 1 second after water is applied to a resin coating film, and a contact angle (ca2) of 65° or more 10 seconds after water is applied to the resin coating film, and wherein, when the total mass of the cationic polymer having a weight-average molecular weight of 700 to 6000 is A and the total mass of the resin particles is B, the value calculated by A / B is in the range of 0.8 to 3.

7.

2. 2. The pretreatment composition according to claim 1, wherein the cationic polymer having a weight average molecular weight of 700 to 6,000 includes at least one structural unit selected from the group consisting of an allylamine structural unit, a diallylamine structural unit, a diallylammonium structural unit, and an epihalohydrin structural unit.

3. The pretreatment composition according to claim 1 or 2, wherein the crosslinking agent comprises at least one selected from the group consisting of a blocked isocyanate group-containing compound, a carbodiimide group-containing compound, and an oxazoline group-containing compound.

4. The pretreatment composition according to claim 3 , wherein the blocked isocyanate group-containing compound has a dissociation temperature of 120° C. or higher.

5. 3. The pretreatment composition according to claim 1, which has a static surface tension at 25° C. of 36 to 60 mN / m.

6. The pretreatment composition according to claim 1 or 2, having a pH of 6.5 to 10.

0.

7. An ink set comprising the pretreatment composition according to claim 1 or 2 and a water-based ink composition containing a pigment, a polymer dispersant, a urethane resin, a water-soluble organic solvent, a surfactant, and water.

8. 8. The ink set according to claim 7, wherein the pigment is a white pigment, the water-soluble organic solvent contains a polyhydric alcohol having a boiling point of 250°C or higher and a polyhydric alcohol having a boiling point of 210°C or lower, and the content of the polyhydric alcohol having a boiling point of 250°C or higher is 20% by mass or less relative to the total mass of the water-based ink composition.

9. 3. An inkjet textile printing method comprising: a pretreatment step of applying the pretreatment composition according to claim 1 or 2 to a fabric; a first drying step of drying the pretreatment composition applied to the fabric; a recording step of applying an ink to at least a part of the pretreatment layer formed on the fabric by the first drying step; and a second drying step of drying the ink.

10. A printed matter printed using the ink set according to claim 7.

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