Image formation methods

Abstract

To provide a method for forming image in which ink bleeding can be suppressed while cloth burning during heating and drying is suppressed.SOLUTION: The image forming method of the present invention includes a step of preparing a pretreated fabric, which is a pretreated fabric containing one or more selected from the group consisting of natural fiber, semi-synthetic fiber made therefrom and regenerated fiber and containing a metal salt of acid and in which the amount of acidic group derived from the metal salt of acid is 5 mmol / m2 or less, and a step of applying an ink containing a solid colorant and water to the surface of the pretreated fabric by inkjet system.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to an image forming method and a pre-treated fabric used therefor. [Background technology]

[0002] In recent years, inkjet printing, which uses an inkjet method to form images on fabrics, has become widely used as a printing method due to its ability to dye fabrics in a short time and its high production efficiency.

[0003] In inkjet printing, tiny droplets of ink are ejected from an inkjet recording head and deposited onto fabric to form an image. The types of colorants contained in the inks used in such inkjet printing include dyes and pigments.

[0004] For inkjet printing, dye-based inks containing reactive dyes are known for use on fabrics such as cotton, rayon, and linen fibers. With dye-based inks, the dyes contained in the ink dissolve in or react with the fibers of the fabric, allowing for highly fixed images without damaging the texture of the fibers. However, this requires a washing process to remove any dyes that did not dissolve or react. From the perspective of eliminating such washing processes, the use of pigment-based inks is being considered.

[0005] Known pigment-based inks include those containing a pigment and a pigment dispersant, and those containing a self-dispersing pigment. Furthermore, the application of metal salts to fabrics through pretreatment is being considered from the perspective of suppressing bleeding of pigment-based inks and improving their fixation by making the pigments in the inks more likely to aggregate.

[0006] For example, a receiving solution containing metal salts such as calcium nitrate, calcium acetate, calcium propionate, calcium pantothenate, CaCl2, MgCl2, and calcium pantothenate salts, with a metal salt concentration of 200 μmol / cm³. 2After applying the pigment in such a manner, an image forming method has been proposed in which an ink containing a pigment and a pigment dispersant having a phosphonic acid group or a carboxylic acid group is applied using an inkjet method (for example, Patent Documents 1 and 2).

[0007] In addition, a pretreatment agent containing a polyvalent metal salt such as calcium nitrate tetrahydrate and polyacrylamide / or polyethylene oxide is applied at a rate of 73-168 g / m². 2 An image forming method has been proposed in which, after applying the pigment in such a manner, an ink containing the pigment and pigment dispersant is applied using an inkjet method (for example, Patent Document 3).

[0008] Furthermore, an image forming method has been proposed in which a pretreatment agent containing a polyvalent metal salt of a carboxylic acid having 3 to 8 carbon atoms, such as calcium propinate, calcium phthalate, or calcium stearate, and a water-dispersible resin is applied to a fabric, and then an ink containing a self-dispersible pigment is applied using an inkjet method (for example, Patent Document 4). [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] International Publication No. 2012 / 132403 [Patent Document 2] Japanese Patent Publication No. 2012-51357 [Patent Document 3] Japanese Patent Publication No. 2009-299240 [Patent Document 4] Japanese Patent Publication No. 2013-159647 [Overview of the project] [Problems that the invention aims to solve]

[0010] In inkjet printing using such pigment-based inks, for example, after applying a pretreatment liquid to a cotton cloth, it may be heated and dried in order to remove the solvent component during the pretreatment. Further, after applying the pigment-based ink to the pretreated cotton cloth, it may be heated and dried in order to remove the solvent component in the ink.

[0011] However, in a cotton cloth to which a pretreatment liquid as shown in Patent Documents 1 to 4 is applied, there is a problem that cloth burning (discoloration) occurs during the heating and drying of the pretreatment liquid or the ink (particularly during the heating and drying of the ink). Since cloth burning is particularly noticeable in white cloth, it tends to be a problem.

[0012] The present invention has been made in view of the above circumstances, and an object thereof is to provide an image forming method and a pretreated fabric capable of suppressing bleeding of ink while suppressing cloth burning during heating and drying.

Means for Solving the Problems

[0013] The present invention relates to the following image forming method and pretreated fabric.

[0014] The image forming method of the present invention is a pretreated fabric containing one or more selected from the group consisting of natural fibers, semi-synthetic fibers made from them, and regenerated fibers, containing a metal salt of an acid, and the amount of acidic groups derived from the metal salt of the acid is 5 mmol / m 2 The method includes a step of preparing a pretreated fabric as described below, and a step of applying, by an inkjet method, an ink containing a solid colorant and water to the surface of the pretreated fabric.

[0015] The pretreated fabric of the present invention is a pretreated fabric for inkjet printing containing one or more selected from the group consisting of natural fibers, semi-synthetic fibers made from them, and regenerated fibers, containing a metal salt of an acid, and the amount of acidic groups derived from the metal salt of the acid is 5 mmol / m 2 Is as follows.

Effects of the Invention

[0016] According to the present invention, it is possible to provide an image forming method and a pretreatment fabric that can suppress bleeding of ink while suppressing fabric burning during heat drying.

Embodiments for Carrying Out the Invention

[0017] In a cotton fabric treated with a pretreatment liquid containing a metal salt of an acid, the mechanism by which fabric burning occurs during heat drying of the pretreatment liquid or ink is not clear, but it is presumed as follows.

[0018] In a cotton fabric to which a large amount of a pretreatment liquid containing a metal salt of an acid is applied, a large amount of an acid derived from the metal salt of the acid adheres. When such a cotton fabric is heated at a high temperature, the cellulose resin constituting the cotton fabric is easily decomposed by the acid. Specifically, the cellulose resin constituting the cotton fabric is easily hydrolyzed by the acid and discoloration easily occurs.

[0019] Actually, in Patent Documents 1 and 2, the amount of the metal salt applied to the fabric is 20 to 2000 μmol / cm 2 (in the examples, 200 μmol / cm 2 ). From these amounts of the metal salt applied and the concentration of the metal salt in the pretreatment liquid (0.1 mol / L), when calculating the amount of acidic groups (Cl) in the fabric, it can be seen that it is extremely large at 400 mmol / m 2 or more. Further, such discoloration is likely to occur not only in cotton fabrics but also in fabrics containing fibers that undergo acid hydrolysis, such as natural fibers and semi-synthetic fibers and regenerated fibers made from them.

[0020] In contrast, the present inventors have found that by applying a metal salt of an acid to the fabric by pretreatment while appropriately reducing the amount applied, specifically, by making the amount of acidic groups in the fabric 5 mmol / m 2 or less, it is possible to suppress fabric burning during drying of the ink.

[0021] Furthermore, in a preferred embodiment, by using a zinc salt or an aluminum salt as the metal salt of the acid applied to the fabric, the ink bleeding suppression effect can be further preserved even when the amount of metal salt applied is reduced as described above. In addition, by using a specific phosphorus-containing group as the hydrophilic group of the pigment dispersant or self-dispersing pigment contained in the ink, the ink's fixability can be further enhanced. In other words, by combining these, it has been found that the bleeding suppression effect can be further preserved and good fixability can be obtained even when the amount of metal salt applied is reduced. The configuration of the present invention will be described below.

[0022] 1. Image forming method The image forming method of the present invention includes 1) a step of preparing a pre-treated fabric (pre-treatment step) and 2) a step of applying an ink containing a solid colorant and water to the surface of the pre-treated fabric using an inkjet method (ink application step).

[0023] Regarding step 1) (pre-treatment step) First, prepare the pre-treated fabric. The pre-treated fabric can be obtained, for example, by applying a pre-treatment solution to the fabric and then drying it.

[0024] (fabric) The fabric includes at least one selected from the group consisting of natural fibers, semi-synthetic fibers derived from natural fibers, and regenerated fibers.

[0025] Examples of natural fibers include cotton (cellulose fiber), linen, wool, and silk. Semi-synthetic fibers are synthetic fibers made from natural fibers, and examples include acetate fibers such as triacetate fibers and ethylcellulose fibers. Regenerated fibers are regenerated fibers made from natural fibers, and examples include viscose rayon and cupro.

[0026] The total content of natural fibers, semi-synthetic fibers, and regenerated fibers is not particularly limited, but may be 20% or more, preferably 50% or more, relative to the total amount of fibers constituting the fabric.

[0027] The fabric may further include fibers other than natural fibers, semi-synthetic fibers, and regenerated fibers, such as chemical fibers. Examples of chemical fibers include rayon, vinylon, nylon, acrylic, polyurethane, and polyester. The fabric may be made from these fibers in any form, such as woven, nonwoven, or knitted fabric. The fabric may also be a blended woven or nonwoven fabric of two or more types of fibers.

[0028] Discoloration due to sun exposure is particularly noticeable on white or light-colored fabrics. The image formation method of the present invention is especially effective on such fabrics.

[0029] (Pretreatment solution) The pretreatment solution contains A) a metal salt of an acid and B) a solvent.

[0030] A) Regarding metal salts of acids Acidic metal salts can have the function of suppressing ink bleeding by making it easier for the pigments contained in the ink to aggregate.

[0031] The acids that make up the metal salts of acids are either organic or inorganic acids. Examples of organic acids include acetic acid, propionic acid, pantothenic acid, ascorbic acid, citric acid, malic acid, lactic acid, tartaric acid, succinic acid, and gluconic acid. Examples of inorganic acids include hydrochloric acid, nitric acid, and sulfuric acid. Among these, inorganic acids are preferred, and hydrochloric acid and nitric acid are more preferred.

[0032] The metal salt of the acid may be a monovalent metal salt or a polyvalent metal salt with two or more valentverdict.

[0033] Examples of metal salts include calcium salts, magnesium salts, zinc salts, nickel salts, and aluminum salts. Among these, polyvalent metal salts are preferred, with aluminum salts and zinc salts being more preferred, from the viewpoint of facilitating the aggregation of pigments contained in the ink through the cross-linking effect (the action of forming multiple ionic bonds).

[0034] In other words, examples of metal salts of acids include metal salts of inorganic acids such as calcium chloride, magnesium chloride, aluminum chloride, calcium nitrate, magnesium nitrate, and magnesium sulfate; and metal salts of organic acids such as calcium salts, magnesium salts, zinc salts, nickel salts, and aluminum salts of acetic acid.

[0035] The content of the metal salt of the acid in the pretreatment solution is not particularly limited, but it may be adjusted so that the concentration of acidic groups derived from the metal salt of the acid is 0.5 to 1000 mmol / L.

[0036] B) Regarding the solvent The solvent is not particularly limited, but it is preferable that it contains at least water. In other words, the pretreatment solution is preferably an aqueous solution.

[0037] The solvent may further contain water-soluble organic solvents as needed, from the viewpoint of moisturizing properties and viscosity adjustment. Examples of water-soluble organic solvents include alcohols (e.g., methanol, ethanol, propanol, pentanol, hexanol, cyclohexanol, benzyl alcohol), polyhydric alcohols (e.g., ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol), and polyhydric alcohol ethers (e.g., ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol This includes (e.g., methyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether), amines (e.g., ethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenediamine, triethylenetetramine), amides (e.g., formamide, N,N-dimethylformamide, N,N-dimethylacetamide), heterocyclic compounds (e.g., 2-pyrrolidone, N-methyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidine), sulfoxides (e.g., dimethyl sulfoxide), and sulfones (e.g., sulfolane). For example, when applied by an inkjet method, the pretreatment agent preferably further contains a water-soluble organic solvent. The content of the water-soluble organic solvent can be 20 to 50% by mass relative to the total amount of solvent contained in the pretreatment solution.

[0038] C) About other ingredients The pretreatment solution may contain other components as needed. Examples of other components include preservatives and pH adjusters.

[0039] Examples of the preservative include aromatic halogen compounds (e.g., Preventol CMK), methylene dithiocyanate, halogen-containing nitrogen-sulfur compounds, 1,2-benzisothiazolin-3-one (e.g., PROXEL GXL), and the like.

[0040] Examples of the pH adjuster include citric acid, sodium citrate, hydrochloric acid, sodium hydroxide, and the like.

[0041] From the viewpoint of not impairing the texture of the fabric material, it is preferable that the pretreatment liquid does not substantially contain a binder resin such as a water-soluble resin or a water-dispersible resin (resin particles). Not substantially containing means, for example, less than 5% by mass with respect to the pretreatment liquid, preferably 0% by mass or less.

[0042] (Application of the pretreatment liquid) As described above, the application of the pretreatment liquid to the fabric is carried out while containing a metal salt of an acid in the fabric so that the amount of acidic groups derived from the metal salt of the acid is 5 mmol / m 2 as follows.

[0043] That is, by containing a metal salt of an acid in the pretreated fabric, when the ink is applied in the step 2) described below, it becomes easier to aggregate the pigment contained in the ink and suppress bleeding. On the other hand, a pretreated fabric containing a large amount of a metal salt of an acid also contains a large amount of an organic acid or an inorganic acid derived from the metal salt of the acid. Therefore, in the step 3) described below, when the applied ink is dried, heating is likely to cause fabric burning.

[0044] In the present invention, the amount of acidic groups in the obtained pretreated fabric is 5 mmol / m 2By applying the pretreatment solution as described below, heat-induced fabric discoloration can be suppressed during the drying process of the pretreatment solution and the drying process of the applied ink (step 3 described below). However, the lower limit of the amount of acidic groups is not 0 (it is greater than 0). Specifically, whether or not the pretreated fabric contains acidic groups means that it is within the range detectable by ion chromatography or capillary electrophoresis (above the detection limit). From a similar viewpoint, the amount of acidic groups in the pretreated fabric (in the pretreated region) is 0.05 mmol / m 2 More than 5mmol / m 2 Preferably less than 0.1 to 4 mmol / m³ 2 It is more preferable that the concentration be 0.1 to 0.5 mmol / m³. 2 It is even more preferable that this be the case.

[0045] Acidic groups are anionic groups derived from organic or inorganic acids that constitute metal salts of acids. Examples of acidic groups include carboxyl groups, chloride ions, nitrate ions, and acetate ions.

[0046] The amount of acidic groups can be calculated from the concentration of the metal salt of the acid in the pretreatment solution and the amount of the pretreatment solution applied to the fabric. For example, if the amount of CaCl2 applied is 27.5 mmol / cm³ 2 The treatment solution is 10 g / m² 2 When added in this manner, the amount of acidic group becomes 0.3 mmol / L.

[0047] Furthermore, the amount of acidic groups can also be measured by the following method: the fabric is immersed in 40°C water and irradiated with ultrasound for 10 minutes or more to extract the metal salts. The amount of extracted anionic components (acidic groups) is then measured by ion chromatography or capillary electrophoresis.

[0048] Alternatively, from the perspective of suppressing heat-induced fabric discoloration, the amount of metal salt in the pre-treated fabric depends on the number of acidic groups in the metal salt, but for example, 5 mmol / m 2 Preferably, 0.01 mmol / m³ 2More than 5mmol / m 2 Less than, more preferably 0.02 to 4 mmol / m³ 2 More preferably 0.02 to 0.5 mmol / m³ 2 A pretreatment solution may be applied to achieve the desired result.

[0049] The amount of acidic groups and the amount of metal salt applied to the pre-treated fabric can be adjusted by controlling the concentration of the metal salt in the pre-treatment solution and the amount of the pre-treatment solution applied.

[0050] The pretreatment solution may be applied to the entire surface of the fabric, or it may be applied selectively only to the area to be inked. In particular, for fabrics where discoloration is easily noticeable, such as white or light-colored fabrics, it is preferable to apply the pretreatment solution selectively only to the area to be inked. When applying the pretreatment solution selectively only to the area to be inked, it is preferable to adjust the amount of pretreatment solution applied according to the amount of ink to be applied.

[0051] The method of applying the pretreatment solution is not particularly limited and may be any of the spray method, coater method, inkjet method, or gravure method. For example, the inkjet method is preferred from the viewpoint of performing steps 1) and 2) consecutively, and the coater method is preferred from the viewpoint of applying a predetermined amount of pretreatment solution in a short time.

[0052] (Drying of pretreatment solution) Next, the pretreatment solution applied to the fabric is dried.

[0053] The drying method is not particularly limited and may include heating with hot air, a hot plate, or a heat roller. Heat drying is preferred from the viewpoint of sufficiently removing solvent components in a short time. The drying temperature may be 100 to 130°C.

[0054] (Pre-treated fabric) The pre-treated fabric obtained in this way contains a metal salt of the aforementioned acid, and the amount of acidic groups derived from the metal salt of the acid is adjusted to the above range. This makes it easier to aggregate the pigment contained in the ink when the ink is applied (step 2 described below), and suppresses discoloration of the fabric due to heat when the applied ink is dried (step 3 described below).

[0055] Although we have described an example of obtaining pre-treated fabric by applying a pre-treatment solution to the fabric, the method is not limited to this, and pre-treated fabric that has been prepared in advance offline (in a separate process) may also be used.

[0056] Regarding step 2) (ink application step) Next, ink is applied to the treated surface (the area that has been pre-treated) of the resulting pre-treated fabric using an inkjet method. Specifically, ink is ejected from the inkjet recording head to apply ink droplets.

[0057] As will be described later, the ink is a water-based ink containing a solid coloring agent such as a pigment and water. From the viewpoint of improving the dispersibility of the pigment, it is preferable that the ink further contains a pigment dispersant or contains a self-dispersing pigment as the pigment. Details of the ink composition will be described later.

[0058] 3) Regarding other processes Furthermore, it is preferable to carry out a step (drying and fixing step) in which the ink applied to the pre-treated fabric is dried and fixed by heating.

[0059] In the drying and fixing process, the ink applied to the pre-treated fabric is dried by heating. This removes the solvent components from the ink and fixes the pigments in the ink.

[0060] The drying method is not particularly limited and may include methods using heaters, hot air dryers, heated rollers, etc. In particular, it is preferable to heat and dry both sides of the pre-treated fabric using a hot air dryer and a heater.

[0061] The drying temperature is not particularly limited, but from the viewpoint of sufficiently removing solvent components such as water contained in the applied ink, it is preferably 110°C or higher, and more preferably 130 to 180°C. The drying time depends on the drying temperature, but can be, for example, about 0.5 to 10 minutes.

[0062] Next, the composition of the ink used in the image forming method of the present invention will be described.

[0063] 2. Ink The ink contains a solid colorant and water.

[0064] 2-1. Solid colorants The solid colorant is not particularly limited, but it is preferable to use a pigment from the viewpoint of easily forming an image with excellent weather resistance.

[0065] The pigments are not particularly limited, but may be, for example, organic or inorganic pigments of the following numbers listed in the color index.

[0066] Examples of red or magenta pigments include Pigment Red 3, 5, 19, 22, 31, 38, 43, 48:1, 48:2, 48:3, 48:4, 48:5, 49:1, 53:1, 57:1, 57:2, 58:4, 63:1, 81, 81:1, 81:2, 81:3, 81:4, 88, 104, 108, 112, 122, 123, 144, 146, 149, 166, 168, 169, 170, 177, 178, 179, 184, 185, 208, 216, 226, 257; Pigment Violet 3, 19, 23, 29, 30, 37, 50, 88; and Pigment Orange 13, 16, 20, 36.

[0067] Examples of blue or cyan pigments include Pigment Blue 1, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 17-1, 22, 27, 28, 29, 36, and 60.

[0068] Examples of green pigments include Pigment Green 7, 26, 36, and 50. Examples of yellow pigments include Pigment Yellow 1, 3, 12, 13, 14, 17, 34, 35, 37, 55, 74, 81, 83, 93, 94, 95, 97, 108, 109, 110, 137, 138, 139, 153, 154, 155, 157, 166, 167, 168, 180, 185, and 193.

[0069] Examples of black pigments include Pigment Black 7, 28, and 26.

[0070] Examples of commercially available pigments include Chromofine Yellow 2080, 5900, 5930, AF-1300, 2700L, Chromofine Orange 3700L, 6730, Chromofine Scarlet 6750, Chromofine Magenta 6880, 6886, 6891N, 6790, 6887, Chromofine Violet RE, Chromofine Red 6820, 6830, Chromofine Blue HS-3, 5187, 5108, 5197, 5085N, SR-5020, 5026, 5050, 4920, 4927, 4937, 4824, 4933GN-EP, 4940, 4973, 5205, 5208, 5214, 5221, and 5000P. Chromofine Green 2GN, 2GO, 2G-550D, 5310, 5370, 6830, Chromofine Black A-1103, Seika Fast Yellow 10GH, A-3, 2035, 2054, 2200, 2270, 2300, 2400(B), 2500, 2600, ZAY-260, 2700(B), 2770 Seika Fast Red 8040, C405(F), CA120, LR-116, 1531B, 8060R, 1547, ZAW-262, 1537B, GY, 4R-4016, 3820, 3891, ZA-215, Seika Fast Carmine 6B1476T-7, 1483LT, 3840, 3870, Seika Fast Bordeaux 10B-430, Seika Light Rose R40, Seika Light Violet B800, 7805, Seika Fast Maroon 460N, Seika Fast Orange 900, 2900, Seika Light Blue C718, A612, Cyanine Blue 4933M, 4933GN-EP, 4940, 4973 (manufactured by Dainichi Seika Kogyo); KET Yellow 401, 402, 403, 404, 405, 406, 416, 424; KET Orange 501; KET Red 301, 302, 303, 304, 305, 306, 307, 308, 309, 310, 336, 337, 338, 346; KET Blue 101, 102, 103, 104, 105, 106, 111, 118, 124; KET Green 201 (manufactured by Dainippon Ink and Chemicals);Colortex Yellow 301, 314, 315, 316, P-624, 314, U10GN, U3GN, UNN, UA-414, U263, Finecol Yellow T-13, T-05, Pigment Yellow1705, Colortex Orange 202, Colortex Red101, 103, 115, 116, D3B, P-625, 102, H-1024, 105C, UFN, UCN, UBN, U3BN, URN, UGN, UG276, U456, U457, 105C, USN, Colortex Maroon601, Colortex BrownB610N, Colortex Violet600, Pigment Red 122, Colortex Blue516, 517, 518, 519, A818, P-908, 510, Colortex Green 402, 403, Colortex Black 702, U905 (manufactured by Sanyo Pigment); Lionol Yellow 1405G, Lionol Blue FG7330, FG7350, FG7400G, FG7405G, ES, ESP-S (manufactured by Toyo Ink), Toner Magenta E02, Permanent Rubin F6B, Toner Yellow HG, Permanent Yellow GG-02, Hostapean Blue B2G (manufactured by Hoechst Industries); Novoperm P-HG, Hostapean Pink E, Hostapean Blue B2G (Clarant); includes carbon black #2600, #2400, #2350, #2200, #1000, #990, #980, #970, #960, #950, #850, MCF88, #750, #650, MA600, MA7, MA8, MA11, MA100, MA100R, MA77, #52, #50, #47, #45, #45L, #40, #33, #32, #30, #25, #20, #10, #5, #44, and CF9 (Mitsubishi Chemical).

[0071] The pigment may be a self-dispersing pigment. A self-dispersing pigment has a surface modified with a hydrophilic group, and comprises pigment particles and a hydrophilic group bonded to its surface.

[0072] Examples of hydrophilic groups include carboxyl groups, sulfonic acid groups, and phosphorus-containing groups. Examples of phosphorus-containing groups include phosphate groups, phosphonic acid groups, phosphinic acid groups, phosphite groups, and phosphate groups. Among these, phosphorus-containing groups are preferred, and phosphate groups or phosphonic acid groups are more preferred, from the viewpoint of high affinity with the metal salts of acids contained in the pretreatment solution.

[0073] The phosphorus-containing group may be the same as those described in paragraphs 0026 to 0035 of Japanese Patent Publication No. 2012-51357. For example, examples of groups having a phosphonic acid group (as a hydrophilic group) include geminal bisphosphonic acid groups and vicinal bisphosphonic acid groups, specifically groups having -CQ(PO3H2)2, -X-(CH2)n-CQ(PO3H2)2, -X-(CH2)n-CQ(PO3H2)2, -X-Sp-(CH2)n-CQ(PO3H2)2, -N-[(CH2)m(PO3H2)]2, -CR=C(PO3H2)2, and -X-[CQ(PO3H2)2] p This includes groups that have such properties.

[0074] Furthermore, in the above formula, Q is H, R, OR, SR, or NR2 (where R is H, a C1-C6 alkyl group, or an aryl group), preferably H, OH, or NH2; n is 0 to 9, preferably 0 to 3, more preferably 0 or 1; X is an arylene group, heteroarylene group, alkylene group, vinylidene group, alkalilene group, aralkylene group, cyclic or heterocyclic group, preferably an arylene group such as a phenylene group, naphthalene group or biphenylene group; Sp is a linking group such as -CO2-, -O2C-, -CO-, -OSO2-, -SO3-, -SO2-, -SO2C2H4O-, -SO2C2H4S-, -SO2C2H4NR-, -O-, -S-, -NR-, -NRCO-, -CONR-, NRCO2-, -O2CNR-, -NRCONR, -N(COR″)CO-, -CON(COR)-, -NRCOCH(CH2CO2R″)-, arylene group, alkylene group, etc. (R is H, C1-C6 alkyl group, or aryl group); p is 1 to 4, preferably 2.

[0075] Examples of groups having a phosphate group (as a hydrophilic group) include the groups listed above as having a phosphonic acid group, in which the phosphonic acid group is replaced with a phosphate group.

[0076] Examples of commercially available self-dispersing pigments include Cabot's Cab-O-Jet® 200K, 250C, 260M, and 270V (sulfonic acid group-containing self-dispersing pigments), Cab-O-Jet® 300K (carboxylic acid group-containing self-dispersing pigment), and Cab-O-Jet® 400K, 450C, 465M, 470V, and 480V (phosphate group-containing self-dispersing pigments).

[0077] The pigment content is not particularly limited, but from the viewpoint of easily adjusting the viscosity of the ink within the above range and enabling the formation of high-density images, it is preferable that it be 1.5 to 15% by mass relative to the ink. If the pigment content is 1.5% by mass or more, it is easy to form high-density images, and if it is 15% by mass or less, the viscosity of the ink does not become too high, so the injection stability is not easily impaired. From the same viewpoint, it is more preferable that the pigment content is 5 to 15% by mass relative to the ink.

[0078] 2-2. Other ingredients Inkjet printing inks may contain other components as needed. Examples of other components may include solvents other than water, pigment dispersants, preservatives, pH adjusters, and so on.

[0079] (solvent) The solvent is not particularly limited, but is preferably a water-soluble organic solvent. The water-soluble organic solvent is not particularly limited as long as it is compatible with water, but from the viewpoint of facilitating the penetration of the ink into the pre-treated fabric and minimizing the impairment of injection stability in the inkjet method, it is preferable that the ink does not thicken easily upon drying. Therefore, it is preferable that the ink contains a high-boiling point solvent with a boiling point of 200°C or higher.

[0080] The high-boiling-point solvent with a boiling point of 200°C or higher can be any water-soluble organic solvent with a boiling point of 200°C or higher, and is preferably a polyol or polyalkylene oxide.

[0081] Examples of polyols with a boiling point of 200°C or higher include divalent alcohols such as 1,3-butanediol (boiling point 208°C), 1,6-hexanediol (boiling point 223°C), and polypropylene glycol; and trivalent or higher alcohols such as glycerin (boiling point 290°C) and trimethylolpropane (boiling point 295°C).

[0082] Examples of polyalkylene oxides with boiling points above 200°C include: Diethylene glycol monoethyl ether (boiling point 202°C), triethylene glycol monomethyl ether (boiling point 245°C), tetraethylene glycol monomethyl ether (boiling point 305°C), tripropylene glycol monoethyl ether (boiling point 256°C); and This includes ethers of divalent alcohols such as polypropylene glycol, and ethers of trivalent or higher alcohols such as glycerin (boiling point 290°C) and hexanetriol.

[0083] The solvent may further contain other solvents besides the high-boiling point solvent mentioned above. Other solvents similar to those listed as specific examples of solvents included in the pretreatment solution can be used.

[0084] (Pigment dispersant) If the pigment is not a self-dispersing pigment, it is preferable that the ink further contains a pigment dispersant to facilitate the dispersion of the pigment.

[0085] From the viewpoint of excellent pigment dispersibility, the pigment dispersant is preferably a polymer dispersant. The type of polymer dispersant is not particularly limited and may be a cationic dispersant, anionic dispersant, or nonionic dispersant. Among these, anionic or nonionic dispersants are preferred, and anionic dispersants are more preferred, from the viewpoint of good affinity with the metal salts of inorganic or organic acids contained in the pre-treated fabric.

[0086] Anionic dispersants are polymeric dispersants having hydrophilic groups selected from the group consisting of carboxylic acid groups, phosphorus-containing groups, and sulfonic acid groups.

[0087] Examples of polymeric dispersants having a carboxylic acid group include polycarboxylic acids or salts thereof. Examples of polycarboxylic acids include (co)polymers of monomers selected from acrylic acid or its derivatives, maleic acid or its derivatives, itaconic acid or its derivatives, fumaric acid or its derivatives, and salts thereof. Examples of other monomers constituting copolymers include styrene and vinylnaphthalene.

[0088] Polymeric dispersants containing phosphorus groups are polymeric dispersants having phosphate groups or phosphonic acid groups. Examples of polymeric dispersants having phosphate groups or phosphonic acid groups include alkyl phosphate esters or their salts.

[0089] Examples of polymeric dispersants having sulfonic acid groups include formalin condensates of aromatic sulfonic acids and formalin condensates of lignin sulfonic acids, with formalin condensates of aromatic sulfonic acids being preferred. An example of a formalin condensate of aromatic sulfonic acids is sodium condensed naphthalene sulfonate.

[0090] The acid value of the anionic dispersant is not particularly limited, but from the viewpoint of increasing the affinity of the acid to the metal salt attached to the pre-treated fabric, it is preferable to have a moderately high acid value, for example, 10 to 300 mg KOH / g or less, preferably 10 to 150 mg KOH / g. The acid value of the anionic dispersant can be measured by the acid value measurement method of JIS K 0070.

[0091] Examples of nonionic dispersants include polyoxyalkylenes and polyoxyalkylene alkyl ethers.

[0092] The pigment dispersant content is preferably 20 to 60% by mass relative to the pigment. A pigment dispersant content of 20% by mass or more makes it easier to sufficiently improve the dispersibility of solid colorants such as pigments, while a content of 60% by mass or less makes it easier to suppress an excessive increase in viscosity. From a similar viewpoint, the pigment dispersant content is preferably 20 to 40% by mass relative to the pigment.

[0093] (Preservatives, pH adjusters) The preservatives and pH adjusters used are the same as those listed as specific examples of preservatives and pH adjusters that can be optionally included in the pretreatment agent.

[0094] Furthermore, if the ink contains a pigment dispersant or self-dispersing pigment, good fixation is more likely to be obtained. This makes it possible to substantially eliminate binder resins (for example, those with a molecular weight exceeding 10,000), such as water-soluble resins or resin particles, from conventional methods. Substantially eliminating them means, for example, that they are 2% by mass or less of the total solid content of the ink. As a result, it is possible to obtain an image-forming product that does not become stiff, does not impair the texture of the fabric material, and has good fixation to the fabric.

[0095] 2-3. Physical Properties The viscosity of the ink at 25°C is not particularly limited, as long as it is sufficient for good ejection by the inkjet method, but it is preferably 3 to 20 mPa·s, and more preferably 4 to 12 mPa·s. The viscosity of the ink can be measured at 25°C using an E-type viscometer.

[0096] 2-4. Ink preparation The ink can be manufactured by any method, for example, by mixing the aforementioned solid colorant with water and any pigment dispersant. [Examples]

[0097] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0098] 1. Materials for the pretreatment solution <Preparation of pretreatment solutions A to F> The components shown in Table 1 were mixed to obtain pretreatment solutions A to F. [Table 1]

[0099] The acidic group concentration of the pretreatment solution was calculated from the composition of the preparation.

[0100] 2. Ink materials (1) Pigments Carbon Black Carboxylic acid group-containing self-dispersing carbon black: Cab-o-jet300K Phosphate-containing self-dispersing carbon black: Cab-o-jet400K

[0101] (2) Dispersant Joncryl 819: Carboxyl group-containing acrylic resin-based dispersant (Joncryl 819 manufactured by BASF Japan, Tg: 57℃, acid value 75 mg KOH / g) DISPERBYK-145: Phosphate ester salt dispersant (acid value 76 mg KOH / g)

[0102] The weight-average molecular weight of the dispersant was measured in styrene equivalent by gel permeation chromatography.

[0103] (3) Solvent Ethylene glycol (boiling point 197.6°C) Glycerin (boiling point 290°C)

[0104] (4) Other ingredients Preservative: Proxel GXL (1,2-benzisothiazolin-3-one) pH adjuster: Citrate buffer

[0105] <Preparation of Inks 1-4> The components shown in Table 2 were mixed to obtain inks 1 to 4, resulting in the compositions shown in Table 2. [Table 2]

[0106] 3. Image Formation and Evaluation <Tests 1, 2, 28, and 29> (Pre-processing) The fabrics (white) shown in Table 3 were prepared. Fabrics 1-5 are as follows: Fabric 1: 100% cotton cloth Fabric 2: Blended fabric of 20% cotton and 80% polyester Fabric 3: Blended fabric of 80% cotton and 20% polyester Fabric 4: Fabric made of 100% acetate fiber Fabric 5: 100% viscose rayon fiber fabric

[0107] Next, the surface of the fabric shown in Table 3 was coated with the pretreatment solution of the type shown in Table 3 using an inkjet method in the amount shown in Table 3, and then dried at 100°C for 2 minutes. This obtained the pretreated fabric. The amount of acidic groups in the pretreated fabric was calculated from the concentration of acidic groups in the pretreatment solution and the amount of pretreatment solution applied.

[0108] <Exams 3-27 and 30-33> (1) Pretreatment Pre-treated fabrics were obtained in the same manner as in Test 1, except that one or more of the following were changed as shown in Table 3: the type of fabric, the type of pre-treatment solution, and the amount applied.

[0109] (2) Ink application Next, an inkjet printer equipped with an inkjet head (Konica Minolta head KM1024iMAE) was prepared as the image forming apparatus. Then, the inks shown in Table 3 were ejected from the nozzles of the inkjet head to form a solid image on the pre-treated fabric (ink application process). Specifically, an image (200 mm x 200 mm in total) including a fine grid, gradation, and solid areas was formed at a main scan of 540 dpi x sub-scan of 720 dpi. dpi represents the number of ink droplets (dots) per 2.54 cm. The ejection frequency was set to 22.4 kHz.

[0110] (3) Drying and fixing Subsequently, the ink-coated fabric was dried in a belt-carry dryer at 150°C for 3 minutes. This resulted in obtaining an image-formed product.

[0111] <Rating> The image formations obtained in tests 3-27 and 30-33 were evaluated for fixation, blurring, and discoloration (fabric burn) using the following methods. Furthermore, the pre-treated fabrics obtained in tests 1, 2, 28, and 29 were evaluated for discoloration (fabric burn).

[0112] (Persistence) The fixation of the image-forming material was evaluated by comparing the image-forming material after one wash in a household washing machine (washing with water) with the image-forming material that had not been washed, and assessing color fading. The evaluation was then performed based on the following criteria. ○: Color fading after rinsing is minimal or nonexistent, and is at a level that poses no practical problems. △: There is some color fading after rinsing, but it is at a level that does not affect practical use. ×: The color fading after rinsing is significant and at a level that poses a practical problem.

[0113] (Smudge) The blurring of the image-formed object was evaluated by visually observing the fine-line grid portion of the image. The evaluation was then performed based on the following criteria. ○: No bleeding occurred. △: Slight bleeding has occurred, but it is at a level that does not affect practical use. ×: Smudges have occurred, and this is at a level that is problematic for practical use.

[0114] (Presence or absence of discoloration) Discoloration of image-forming materials or pre-treated fabrics was visually compared between samples dried without heating and samples dried at 150°C for 3 minutes. The results were then evaluated based on the following criteria. ○: Not discolored △: There is some minor discoloration in some areas, but it does not affect practical use. ×: Discolored, to a level that poses a practical problem.

[0115] The evaluation results for tests 1-33 are shown in Table 3. [Table 3]

[0116] As shown in Table 3, the amount of acidic groups in the pre-treated fabric was 5 mmol / m². 2 In the following tests 1-27 (the present invention), no discoloration due to fabric burning was observed. Furthermore, there was no bleeding, and the fixation was good.

[0117] In particular, pretreatment agent D is found to be a better match with inks 2 and 4 (than with inks 1 and 3) (comparison of tests 6, 8, 20, and 21). Pretreatment agent E is found to be a better match with inks 2 and 4 (than with inks 1 and 3) (comparison of tests 7, 9, 22, and 23). In addition, ink 4 is found to be a better match with pretreatment agents D and E (than with pretreatment agents A-C) (comparison of tests 17-20 and 23). From these findings, it can be concluded that the combination of pretreatment agent D or E with ink 2 or 4 is good, meaning that it is good when the metal salt contained in the pretreatment agent is an aluminum salt or a zinc salt, and the hydrophilic group of the pigment dispersant contained in the ink is a phosphate group or a phosphonic acid group.

[0118] In contrast, the amount of acidic groups in the pre-treated fabric is 5 mmol / m 2 In tests 28-33 (comparative examples) exceeding this level, it was found that discoloration due to fabric burning occurred. [Industrial applicability]

[0119] According to the present invention, it is possible to provide an image forming method and a pre-treated fabric that can suppress ink bleeding while suppressing fabric discoloration during heat drying.

Claims

1. A pre-treated fabric comprising one or more fibers selected from the group consisting of natural fibers, semi-synthetic fibers derived therefrom, and regenerated fibers, wherein the fabric contains a metal salt of an acid, and the amount of acidic groups derived from the metal salt of the acid is 5 mmol / m ２ The following are the steps for preparing the pre-treated fabric, The process includes applying an ink containing a solid coloring agent and water to the surface of the pre-treated fabric using an inkjet method. The aforementioned metal salt is an aluminum salt or a zinc salt. The ink contains a self-dispersing pigment having a phosphate group or a phosphonic acid group as the solid colorant, or The ink comprises a pigment and a pigment dispersant having a phosphate group or a phosphonic acid group. Image forming method.

2. In the process of preparing the aforementioned pre-treated fabric, A pretreatment solution containing the metal salt of the aforementioned acid and a solvent is applied to a fabric containing one or more fibers selected from the group consisting of natural fibers, semi-synthetic fibers derived from them, and regenerated fibers. The image forming method according to claim 1.

3. The process further includes heating the ink applied to the pre-treated fabric at 110°C or higher to dry it. The image forming method according to claim 1 or 2.

4. The acid is hydrochloric acid, acetic acid, or nitric acid. The image forming method according to any one of claims 1 to 3.

5. In the process of preparing the aforementioned pre-treated fabric, The pretreatment solution is selectively applied to the area to which the ink is applied. The image forming method according to claim 2.

6. The amount of the pretreatment solution applied is adjusted according to the amount of ink applied. The image forming method according to claim 5.

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