Aqueous adhesive composition for textile printing, conveyor belt and printing apparatus

Abstract

The present invention provides an aqueous adhesive composition for textile printing that has excellent storage stability and can be suitably used to form an adhesive layer that is excellent in durability, a conveyor belt having an adhesive layer formed using the aqueous adhesive composition for textile printing, and a textile printing device that includes the conveyor belt. The aqueous pressure-sensitive adhesive composition for textile printing of the present invention contains water, a (meth)acrylic resin, and a persulfate, and the content of the persulfate is 100 ppm or more and 2000 ppm or less. The pH of the aqueous pressure-sensitive adhesive composition for textile printing at 23°C is preferably 7.5 or more and 9.0 or less.

Description

[Technical Field]

[0001] The present invention relates to an aqueous pressure-sensitive adhesive composition for textile printing, a conveyor belt, and a textile printing apparatus. [Background technology]

[0002] In a textile printing method in which an ink composition is applied to a fabric as a recording medium to dye it, an adhesive layer is formed on the surface of a conveyor belt that conveys the fabric and that comes into contact with the fabric, thereby adhering the fabric to the conveyor belt and enabling the fabric to be conveyed stably.

[0003] To form such an adhesive layer, a liquid adhesive containing an adhesive is used. The adhesive layer must have adequate adhesive strength to allow the fabric fixed to the conveyor belt to be easily attached and detached, as well as water resistance and mechanical strength to withstand water washing. For this reason, adhesives made by dissolving hydrophobic resins in organic solvents have been used.

[0004] Adhesives containing organic solvents volatilize when applied to a conveyor belt, necessitating sufficient ventilation and other restrictions on the surrounding environment. Therefore, there is a demand for water-based adhesives that do not volatilize organic solvents. Patent Document 1 proposes such water-based adhesives. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 59-53790 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the adhesives described above have problems such as low storage stability and low durability of the adhesive layer formed using the adhesives. [Means for solving the problem]

[0007] The present invention has been made to solve the above-mentioned problems, and can be realized as the following application examples.

[0008] The aqueous pressure-sensitive adhesive composition for textile printing according to an application example of the present invention contains water, a (meth)acrylic resin, and a persulfate, The content of the persulfate is 100 ppm or more and 2000 ppm or less.

[0009] A conveyor belt according to an application example of the present invention is a conveyor belt for conveying a fabric to be printed by textile printing, An adhesive layer formed using the aqueous adhesive composition for textile printing according to the application example of the present invention is provided on the surface that comes into contact with the fabric.

[0010] A textile printing apparatus according to an application example of the present invention includes a conveyor belt according to an application example of the present invention; an inkjet head having nozzles that eject ink onto the fabric being transported by the transport belt; [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram of a textile printing apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing a state in which the conveying device provided in the textile printing apparatus shown in FIG. 1 is performing a leveling process. [Figure 3] FIG. 3 is a flowchart illustrating an example of a method for forming an adhesive layer. [Figure 4] FIG. 4 is a table summarizing the compositions and the like of the aqueous pressure-sensitive adhesive compositions for textile printing of each Example and each Comparative Example. [Figure 5] FIG. 5 is a table summarizing the evaluation results of each example and each comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0012] Preferred embodiments of the present invention will be described in detail below. [1] Aqueous adhesive composition for textile printing First, the aqueous pressure-sensitive adhesive composition for textile printing of the present invention will be described.

[0013] The aqueous pressure-sensitive adhesive composition for textile printing of the present invention is used to form a pressure-sensitive adhesive layer that is provided on the surface of a transport belt that transports a fabric to be printed by textile printing, the surface coming into contact with the fabric.

[0014] The aqueous pressure-sensitive adhesive composition for textile printing of the present invention contains water, a (meth)acrylic resin, and a persulfate, and the content of the persulfate is 100 ppm or more and 2000 ppm or less. This configuration ensures excellent storage stability of the aqueous pressure-sensitive adhesive composition for textile printing, while also ensuring excellent durability of the adhesive layer formed using the aqueous pressure-sensitive adhesive composition for textile printing. Furthermore, the use of water eliminates the need for an organic solvent, eliminating the need to consider problems associated with the use of organic solvents, more specifically, the environmental impact of organic solvent volatilization. Furthermore, by forming an adhesive layer using such an aqueous pressure-sensitive adhesive composition for textile printing, the fabric can be stably fixed to a conveyor belt during printing, and the printed material obtained by printing can be easily peeled off from the conveyor belt.

[0015] On the other hand, if the above conditions are not met, satisfactory results will not be obtained. For example, if the aqueous pressure-sensitive adhesive composition for textile printing does not contain water but contains an organic solvent instead, the aforementioned effects of using water cannot be obtained. Furthermore, if the aqueous pressure-sensitive adhesive composition for textile printing does not contain a persulfate, or if it contains a persulfate content below the lower limit, the durability of the adhesive layer formed using the aqueous pressure-sensitive adhesive composition for textile printing will be significantly inferior. Furthermore, if the persulfate content in the aqueous pressure-sensitive adhesive composition for textile printing exceeds the upper limit, the storage stability of the aqueous pressure-sensitive adhesive composition for textile printing will be significantly reduced.

[0016] The transport belt having an adhesive layer formed using the aqueous adhesive composition for textile printing of the present invention and the textile printing device having the transport belt will be described in detail later.

[0017] [1-1]Water The aqueous pressure-sensitive adhesive composition for textile printing contains water.

[0018] Water is a component that imparts fluidity to the aqueous pressure-sensitive adhesive composition for textile printing. In the aqueous pressure-sensitive adhesive composition for textile printing, water functions as a solvent for dissolving or a dispersion medium for dispersing components other than water, such as the (meth)acrylic resin and the persulfate.

[0019] The water content in the aqueous pressure-sensitive adhesive composition for textile printing is not particularly limited, but is preferably from 30.0 to 80.0% by mass, and more preferably from 35.0 to 70.0% by mass, which can provide more suitable fluidity and viscosity of the aqueous pressure-sensitive adhesive composition for textile printing, and can provide more excellent coatability of the aqueous pressure-sensitive adhesive composition for textile printing and more uniform thickness of the adhesive layer formed using the aqueous pressure-sensitive adhesive composition for textile printing.

[0020] [1-2] (Meth)acrylic resin The aqueous pressure-sensitive adhesive composition for textile printing contains a (meth)acrylic resin.

[0021] The (meth)acrylic resin has the function of imparting adhesiveness to the adhesive layer formed from the aqueous adhesive composition for textile printing.

[0022] In particular, by using a (meth)acrylic resin among various adhesive components, the adhesive strength of the adhesive layer can be made more appropriate. Furthermore, the water resistance and mechanical strength of the adhesive layer can also be made more excellent. This makes it possible to more suitably suppress, for example, an undesired decrease in adhesive strength when an adhesive layer formed using the aqueous adhesive composition for textile printing is brushed with water.

[0023] The (meth)acrylic resin is not particularly limited as long as it is a polymer containing a (meth)acrylic monomer such as (meth)acrylic acid or a (meth)acrylic acid ester as at least a portion of the monomer component. For example, the (meth)acrylic resin may be a homopolymer formed by polymerizing one type of (meth)acrylic monomer, or may be a copolymer containing multiple types of (meth)acrylic monomers as monomer components. Furthermore, the (meth)acrylic resin may be a copolymer containing, in addition to the (meth)acrylic monomer, a monomer other than the (meth)acrylic monomer as a monomer component.

[0024] The (meth)acrylic resin constituting the aqueous pressure-sensitive adhesive composition for textile printing of the present invention may contain multiple different polymers. For example, the (meth)acrylic resin may be obtained by blending multiple polymers synthesized under different conditions.

[0025] The (meth)acrylic monomer is not particularly limited, but examples thereof include (meth)acrylic monomers having an acidic group, (meth)acrylic monomers having an ester structure, and (meth)acrylic monomers having an amide structure. Examples of (meth)acrylic monomers having an acidic group include acrylic acid and methacrylic acid. Examples of (meth)acrylic monomers having an ester structure include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, butyl acrylate, butyl methacrylate, lauryl acrylate, lauryl methacrylate, isoamyl acrylate, isoamyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, cyclohexyl acrylate, and cyclohexyl methacrylate. Examples of (meth)acrylic monomers having an amide structure include acrylamide, methacrylamide, and N-isopropylacrylamide.

[0026] The monomer other than the (meth)acrylic monomer is not particularly limited, but examples thereof include styrene and acrylonitrile.

[0027] The (meth)acrylic resin preferably contains, as a constituent monomer, a first monomer whose glass transition temperature when made into a homopolymer is −60° C. or lower, thereby more suitably increasing the adhesive strength of the adhesive layer formed from the aqueous pressure-sensitive adhesive composition for textile printing, and enabling the fabric to be more stably fixed to the conveyor belt.

[0028] For measuring the glass transition temperature of a homopolymer, a homopolymer having a weight-average molecular weight of 100,000 to 5,000,000 can be used. In homopolymers having a weight-average molecular weight in this range, the effect of the molecular weight on the glass transition temperature is sufficiently small that it can be ignored.

[0029] The glass transition temperature of the homopolymer of the first monomer may be −60° C. or lower, preferably −100° C. or higher and −62° C. or lower, and more preferably −90° C. or higher and −64° C. or lower, so that the above-mentioned effects are more pronounced.

[0030] A preferred first monomer is 2-ethylhexyl acrylate.

[0031] When the (meth)acrylic resin contains a first monomer as a constituent monomer, the proportion of the first monomer in all the monomers constituting the (meth)acrylic resin is preferably 20.0 to 50.0 mass%, more preferably 25.0 to 45.0 mass%, and even more preferably 30.0 to 40.0 mass%. This makes it possible to improve the adhesive strength of the adhesive layer formed from the aqueous adhesive composition for textile printing, and during printing, the fabric can be more stably fixed to the conveyor belt, and the printed material obtained by printing can be more easily peeled from the conveyor belt.

[0032] The (meth)acrylic resin preferably contains, as a constituent monomer, a second monomer whose glass transition temperature when made into a homopolymer is 40°C or higher. This allows the adhesive layer formed from the aqueous pressure-sensitive adhesive composition for textile printing to have better mechanical strength. Furthermore, the adhesive strength of the adhesive layer formed from the aqueous pressure-sensitive adhesive composition for textile printing can be made more suitable, allowing the fabric to be sufficiently and stably fixed to the conveyor belt during printing, and allowing the printed material to be more easily peeled from the conveyor belt.

[0033] The glass transition temperature of the homopolymer of the second monomer may be 40° C. or higher, preferably −45° C. or higher and 150° C. or lower, more preferably 50° C. or higher and 140° C. or lower, and even more preferably 60° C. or higher and 135° C. or lower, so that the above-mentioned effects are more significantly exhibited.

[0034] The (meth)acrylic resin may contain a monomer having an acidic functional group as the second monomer, which can improve the storage stability of the aqueous pressure-sensitive adhesive composition for textile printing.

[0035] Preferred second monomers include acrylic acid, methacrylic acid, methyl methacrylate, ethyl methacrylate, cyclohexyl acrylate, and cyclohexyl methacrylate.

[0036] When the (meth)acrylic resin contains the first monomer as a constituent monomer, the proportion of the second monomer in all monomers constituting the (meth)acrylic resin is preferably 20.0% by mass or more and 50.0% by mass or less, more preferably 25.0% by mass or more and 45.0% by mass or less, and even more preferably 30.0% by mass or more and 40.0% by mass or less. This can further improve the mechanical strength of the adhesive layer formed from the aqueous adhesive composition for textile printing. Furthermore, this can further improve the adhesive strength of the adhesive layer formed from the aqueous adhesive composition for textile printing. During printing, the fabric can be sufficiently and stably fixed to the conveyor belt, and the printed material obtained by printing can be more easily peeled from the conveyor belt.

[0037] When the (meth)acrylic resin contains a first monomer and a second monomer as constituent monomers, where X1 (mass%) is the mass ratio of the first monomer in the (meth)acrylic resin and X2 (mass%) is the mass ratio of the second monomer, the relationship of 0.7≦X2 / X1≦1.4 is preferably satisfied, the relationship of 0.8≦X2 / X1≦1.3 is more preferably satisfied, and the relationship of 0.9≦X2 / X1≦1.2 is even more preferably satisfied. This can further improve the adhesive strength of the adhesive layer formed from the aqueous adhesive composition for dyeing, which can more stably fix the fabric to the conveyor belt during printing and more efficiently release the printed material from the conveyor belt. Furthermore, the mechanical strength of the adhesive layer formed from the aqueous adhesive composition for textile printing can be improved.

[0038] The (meth)acrylic resin preferably contains, in addition to the first and second monomers, a third monomer as a constituent monomer, the third monomer having a glass transition temperature of more than −60° C. and less than 40° C. when made into a homopolymer. This makes it possible to improve the adhesive strength of the adhesive layer formed from the aqueous pressure-sensitive adhesive composition for textile printing, and during printing, the fabric can be more stably fixed to the conveyor belt, and the printed material can be more easily peeled from the conveyor belt.

[0039] The glass transition temperature of the homopolymer of the third monomer may be higher than −60° C. and lower than 40° C., but is preferably −58° C. or higher and 30° C. or lower, and more preferably −56° C. or higher and 25° C. or lower, so that the above-mentioned effects are more significantly exhibited.

[0040] Preferred third monomers include butyl acrylate, butyl methacrylate, and isoamyl acrylate.

[0041] When the (meth)acrylic resin contains a third monomer as a constituent monomer, the proportion of the third monomer in all the monomers constituting the (meth)acrylic resin is preferably 10.0 to 40.0 mass%, more preferably 15.0 to 35.0 mass%, and even more preferably 20.0 to 30.0 mass%. This makes it possible to further improve the adhesive strength of the adhesive layer formed from the aqueous adhesive composition for textile printing, and during printing, it is possible to more stably fix the fabric to the conveyor belt and more efficiently peel the printed material from the conveyor belt.

[0042] When the mass ratio of the first monomer in the (meth)acrylic resin is X1 [mass%] and the mass ratio of the third monomer is X3 [mass%], it is preferable to satisfy the relationship 0.8≦X1 / X3≦1.7, more preferably the relationship 0.9≦X1 / X3≦1.6, and even more preferably the relationship 1.0≦X1 / X3≦1.5, thereby more significantly achieving the above-mentioned effects.

[0043] When the mass ratio of the second monomer in the (meth)acrylic resin is X2 [mass%] and the mass ratio of the third monomer is X3 [mass%], it is preferable to satisfy the relationship 0.8≦X2 / X3≦1.7, more preferably the relationship 0.9≦X2 / X3≦1.6, and even more preferably the relationship 1.0≦X2 / X3≦1.5, thereby more significantly exhibiting the above-mentioned effects.

[0044] The content of the (meth)acrylic resin in the aqueous pressure-sensitive adhesive composition for textile printing is preferably 20.0% by mass or more and 70.0% by mass or less, and more preferably 30.0% by mass or more and 60.0% by mass or less. This allows the mechanical strength of the adhesive layer formed from the aqueous pressure-sensitive adhesive composition for textile printing to be improved. Furthermore, the adhesive strength of the adhesive layer formed from the aqueous pressure-sensitive adhesive composition for textile printing can be improved, allowing the fabric to be stably fixed to the conveyor belt during printing and allowing the printed record to be more easily peeled from the conveyor belt. Furthermore, the application property and storage stability of the aqueous pressure-sensitive adhesive composition for textile printing can be improved.

[0045] [1-3] Persulfate The aqueous pressure-sensitive adhesive composition for textile printing contains a predetermined amount of persulfate. More specifically, the content of persulfate in the aqueous pressure-sensitive adhesive composition for textile printing of the present invention may be 100 ppm or more and 2000 ppm or less, preferably 120 ppm or more and 1500 ppm or less, more preferably 130 ppm or more and 1200 ppm or less, and even more preferably 150 ppm or more and 1000 ppm or less. This makes the above-mentioned effects more pronounced.

[0046] Examples of persulfates include alkali metal salts such as sodium persulfate, potassium persulfate, sodium hydrogen persulfate, and potassium hydrogen persulfate; alkaline earth metal salts such as magnesium persulfate and calcium persulfate; and ammonium salts such as ammonium persulfate. Ammonium persulfate is preferred. This allows the durability of the adhesive layer formed using the aqueous pressure-sensitive adhesive composition for textile printing to be more stably maintained. Furthermore, the storage stability of the aqueous pressure-sensitive adhesive composition for textile printing can be improved.

[0047] The persulfate contained in the aqueous pressure-sensitive adhesive composition for textile printing may be a residue of a thermal polymerization initiator used in the synthesis of the (meth)acrylic resin. The content of the persulfate in the aqueous pressure-sensitive adhesive composition for textile printing can be adjusted, for example, by the amount of the thermal polymerization initiator used in the synthesis of the (meth)acrylic resin, or the reaction time and reaction temperature of the synthesis reaction of the (meth)acrylic resin.

[0048] [1-4] Monomer The aqueous pressure-sensitive adhesive composition for textile printing may contain 1000 ppm or less of unpolymerized monomers that are the same as the monomers constituting the (meth)acrylic resin described above. This can improve the safety of the aqueous pressure-sensitive adhesive composition for textile printing. Furthermore, since the amount of unpolymerized monomers is not drastically reduced (to less than 10 ppm, for example), the amount of persulfate used can be reduced.

[0049] The content of the monomer in the aqueous pressure-sensitive adhesive composition for textile printing is preferably 1,000 ppm or less, more preferably 10 ppm to 800 ppm, and even more preferably 100 ppm to 500 ppm, which not only more significantly exhibits the above-mentioned effects but also facilitates the synthesis of the (meth)acrylic resin and eliminates the need for excessive purification after synthesis of the (meth)acrylic resin, which is advantageous in terms of productivity and cost of the aqueous pressure-sensitive adhesive composition for textile printing.

[0050] [1-5] Alcohol compounds When the (meth)acrylic resin contains an ester compound of (meth)acrylic acid represented by the following formula (1) as a constituent monomer, the aqueous pressure-sensitive adhesive composition for textile printing may further contain an alcohol compound represented by the following formula (2) in a content of 1000 ppm or less:

[0051] R 1 -C(=CH2)-C(=O)-OR 2 … (1) (In formula (1), R 1 is H or CH3, and R 2 is a hydrocarbon group. R 2 -OH … (2) (In formula (2), R 2 is a hydrocarbon group.

[0052] This allows the durability of the adhesive layer formed using the aqueous adhesive composition for textile printing to be improved, because the reduction of the persulfate by extending the reaction time can be suppressed, thereby reducing the amount of alcohol compounds obtained by hydrolysis of the (meth)acrylic acid ester compound.

[0053] The content of the alcohol compound in the aqueous pressure-sensitive adhesive composition for textile printing is preferably 1,000 ppm or less, more preferably 10 ppm to 900 ppm, and even more preferably 100 ppm to 700 ppm, which not only more significantly exhibits the above-mentioned effects but also facilitates the synthesis of the (meth)acrylic resin and eliminates the need for excessive purification after the synthesis of the (meth)acrylic resin, which is advantageous in terms of productivity and cost of the aqueous pressure-sensitive adhesive composition for textile printing.

[0054] The alcohol compound depends on the type of (meth)acrylic acid ester compound used as a constituent monomer of the (meth)acrylic resin. For example, when the (meth)acrylic resin contains methyl acrylate or methyl methacrylate as a constituent monomer, the alcohol compound is methanol. When the (meth)acrylic resin contains ethyl acrylate or ethyl methacrylate as a constituent monomer, the alcohol compound is ethanol. When the (meth)acrylic resin contains n-propyl acrylate or n-propyl methacrylate as a constituent monomer, the alcohol compound is n-propanol. When the (meth)acrylic resin contains butyl acrylate or butyl methacrylate as a constituent monomer, the alcohol compound is butanol.

[0055] [1-6] Preservatives The aqueous pressure-sensitive adhesive composition for textile printing may contain a preservative, which can effectively prevent spoilage caused by microorganisms in the aqueous pressure-sensitive adhesive composition for textile printing and in an adhesive layer formed using the aqueous pressure-sensitive adhesive composition for textile printing.

[0056] The preservative may be an inorganic preservative, but is preferably an organic preservative, which can provide the aqueous pressure-sensitive adhesive composition for textile printing with better storage stability.

[0057] Examples of inorganic antiseptics include those in which antibacterial silver, zinc, or copper is supported on a carrier such as zeolite, silica gel, potassium titanate whisker, or magnesium oxide whisker.

[0058] Examples of organic antiseptics include thiazoline-based antibacterial agents, imidazole-based antibacterial agents, ester-based antibacterial agents, and carboxylic acid-based antibacterial agents.

[0059] Examples of thiazoline antibacterial agents include 2-n-octyl-4-isothiazolon-3-one, 1,2-benzisothiazol-3(2H)-one, methylisothiazolinone, and 5-chloro-2-methyl-4-isothiazolin-3-one.

[0060] Examples of imidazole antibacterial agents include 2-(4-thiazolyl)-benzimidazole, methyl-2-benzimidazole carbamate, and the like. Examples of ester-based antibacterial agents include glycerol monolaurate.

[0061] Examples of carboxylic acid antibacterial agents include sorbic acid and its salts, and examples of the salts include potassium salts.

[0062] Among these, thiazoline-based antibacterial agents are preferred as the preservative, with 1,2-benzisothiazol-3(2H)-one being more preferred. This allows for better affinity with the (meth)acrylic resin (particularly, a (meth)acrylic resin containing the preferred first, second, and third monomers as constituent monomers). As a result, the preservative can be more uniformly dispersed in the adhesive layer, allowing for better mechanical strength, water resistance, antiseptic properties, etc. of the adhesive layer.

[0063] When the aqueous pressure-sensitive adhesive composition for textile printing contains a preservative, the content of the preservative in the aqueous pressure-sensitive adhesive composition for textile printing is not particularly limited, but is preferably from 0.001 to 0.10% by mass, more preferably from 0.01 to 0.05% by mass, and even more preferably from 0.02 to 0.04% by mass, thereby more significantly exhibiting the above-mentioned effects of containing the preservative and more favorably improving the adhesiveness, durability, etc. of the adhesive layer formed using the aqueous pressure-sensitive adhesive composition for textile printing.

[0064] [1-7] Surfactants The aqueous pressure-sensitive adhesive composition for textile printing may contain a surfactant. The surfactant is not particularly limited, but examples thereof include anionic surfactants, nonionic surfactants, and cationic surfactants.

[0065] Examples of anionic surfactants include alkyl sulfocarboxylates, alkyl diphenyl ether disulfonates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, N-acylamino acids and salts thereof, N-acylmethyl taurines, alkyl sulfates such as ammonium lauryl sulfate and sodium lauryl sulfate, alkyl sulfate polyoxyalkyl ether sulfates, alkyl sulfate polyoxyethylene alkyl ether phosphates, rosin acid soap, castor oil sulfate esters, lauryl alcohol sulfate esters, alkylphenol phosphate esters, alkyl phosphate esters, alkylaryl sulfonates, diethyl sulfosuccinate, diethylhexyl sulfosuccinate, and dioctyl sulfosuccinate.

[0066] Examples of nonionic surfactants include acetylene glycol surfactants, silicone surfactants, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene hydrogenated castor oil, propylene glycol fatty acid esters, glycerin fatty acid esters, polyglycerin fatty acid esters, sorbitan fatty acid esters, sucrose fatty acid esters, alkyl polyglycosides, alkyldiethanolamides, alkylamine oxides, etc. Examples of commercially available nonionic surfactants include Emulgen 123P, 430, 1108 (product names of Kao Corporation), Newcol 1006, 1008, 1020 (product names of Nippon Nyukazai Co., Ltd.), Noigen DL-0415, ET-116B, ET-106A, DH-0300, YX-400, EA-160 (product names of Daiichi Kogyo Seiyaku Co., Ltd.), etc.

[0067] Examples of cationic surfactants include alkylamine salts, fatty acid amidoamine salts, monoalkyl quaternary ammonium salts, dialkyl quaternary ammonium salts, trialkyl quaternary ammonium salts, benzalkonium quaternary ammonium salts, benzethonium chloride, and alkylpyridinium salts.

[0068] Among these, anionic surfactants are preferred, and alkyl ether-based nonionic surfactants are more preferred, as this further stabilizes the final emulsion.

[0069] The content of the surfactant in the aqueous pressure-sensitive adhesive composition for textile printing is preferably 1.0% by mass or more and 5.0% by mass or less, and more preferably 1.5% by mass or more and 5.0% by mass or less.

[0070] [1-8] Tackifier The aqueous pressure-sensitive adhesive composition for textile printing may contain a tackifier.

[0071] Examples of tackifiers include rosin compounds, terpene compounds, hydrocarbon resins, etc. More specifically, examples include rosin compounds such as natural rosin, modified rosin, glycerol esters of natural rosin, glycerol esters of modified rosin, pentaerythritol esters of natural rosin, and pentaerythritol esters of modified rosin; terpene compounds such as copolymers of natural terpene, three-dimensional polymers of natural terpene, aromatic modified terpene resins, hydrogenated derivatives of aromatic modified terpene resins, terpene phenol resins, and terpene resins (monoterpenes, diterpenes, triterpenes, polyterpenes, etc.); and hydrocarbon resins such as aliphatic petroleum hydrocarbon resins (C5 resins), hydrogenated derivatives of aliphatic petroleum hydrocarbon resins, aromatic petroleum hydrocarbon resins (C9 resins) such as styrene oligomers, and hydrogenated derivatives of aromatic petroleum hydrocarbon resins.

[0072] When the aqueous pressure-sensitive adhesive composition for textile printing contains a tackifier, the content of the tackifier in the aqueous pressure-sensitive adhesive composition for textile printing is not particularly limited, but is preferably 5.0 mass % or less, more preferably 4.0 mass % or less, and even more preferably 0.1 mass % to 3.8 mass % or less, which makes the adhesive strength of the adhesive layer formed using the aqueous pressure-sensitive adhesive composition for textile printing more suitable and makes it easier to maintain the effect of suppressing a decrease in adhesive strength when the adhesive layer is brushed for a longer period of time.

[0073] [1-9] Colorants The aqueous pressure-sensitive adhesive composition for textile printing may contain a coloring material. As the coloring material, for example, various pigments and various dyes can be used.

[0074] When the aqueous pressure-sensitive adhesive composition for textile printing contains a colorant, the content of the colorant in the aqueous pressure-sensitive adhesive composition for textile printing is preferably 1.0 mass % or less, and more preferably 0.5 mass % or less.

[0075] [1-10] Other ingredients The aqueous pressure-sensitive adhesive composition for textile printing may contain components other than those described above. Hereinafter, such components may also be referred to as "other components."

[0076] Examples of other components include resin materials other than (meth)acrylic resins, antioxidants, colorants, antistatic agents, flame retardants, flame retardant assistants, ultraviolet absorbers, aggregation inhibitors, processing aids, plasticizers, and defoamers.

[0077] Examples of resin materials other than (meth)acrylic resins include urethane resins, silicone resins, and various elastomers (rubber-based materials).

[0078] However, the content of other components in the aqueous pressure-sensitive adhesive composition for textile printing is preferably 10.0% by mass or less, more preferably 5.0% by mass or less, and even more preferably 3.0% by mass or less.

[0079] In particular, from the viewpoint of reducing environmental load and restrictions on the surrounding environment due to the volatilization of organic solvents, the aqueous pressure-sensitive adhesive composition for textile printing preferably does not contain any organic solvent or contains only a small amount of organic solvent. More specifically, the content of organic solvent in the aqueous pressure-sensitive adhesive composition for textile printing is preferably 5.0 mass % or less, more preferably 2.5 mass % or less, and even more preferably 0.5 mass % or less.

[0080] [1-11]Other conditions The aqueous pressure-sensitive adhesive composition for textile printing preferably contains ammonium ions. This allows the pH of the aqueous pressure-sensitive adhesive composition for textile printing to be relatively high, and in particular, allows the aqueous pressure-sensitive adhesive composition for textile printing to be suitably kept alkaline. As a result, hydrolysis of the (meth)acrylic resin can be more effectively suppressed, and the durability of the adhesive layer formed using the aqueous pressure-sensitive adhesive composition for textile printing can be more stably maintained. In addition, the storage stability of the aqueous pressure-sensitive adhesive composition for textile printing can be improved.

[0081] The pH of the aqueous pressure-sensitive adhesive composition for textile printing at 23°C is preferably 7.5 or more and 9.0 or less, more preferably 7.7 or more and 8.8 or less, and even more preferably 7.9 or more and 8.6 or less. This more effectively suppresses hydrolysis of the (meth)acrylic resin, and more stably maintains the durability of the adhesive layer formed using the aqueous pressure-sensitive adhesive composition for textile printing. Furthermore, the storage stability of the aqueous pressure-sensitive adhesive composition for textile printing can be improved.

[0082] The viscosity of the aqueous pressure-sensitive adhesive composition for textile printing at 23°C is not particularly limited, but is preferably from 10 mPa·s to 300 mPa·s, more preferably from 10 mPa·s to 300 mPa·s, which improves the handleability of the aqueous pressure-sensitive adhesive composition for textile printing when it is applied, and more effectively prevents unintended variations in the thickness and surface properties of the adhesive layer formed.

[0083] The storage modulus of the adhesive layer formed using the aqueous adhesive composition for textile printing at 23°C is 1.5 x 10 5 Pa or more 5.0×10 5 Pa or less, and 1.6 × 10 5 Pa or more 4.8×10 5 Pa or less is more preferable, and 2.0×10 5 Pa or more 4.5×10 5 It is more preferable that the pressure is 100 Pa or less.

[0084] The method for forming the adhesive layer for measuring the storage modulus is not particularly limited. For example, a method can be used in which the aqueous adhesive composition for textile printing is applied to a 25 mm wide slide glass to a thickness of 0.2 mm in an environment of 23°C, and then dried under conditions of 50% humidity, 23°C, and 8 hours.

[0085] [2] Printing equipment and conveyor belt Next, the conveyor belt and the printing apparatus of the present invention will be described.

[0086] The transport belt of the present invention is a transport belt for transporting a fabric to be printed by textile printing, and has an adhesive layer formed using the aqueous pressure-sensitive adhesive composition for textile printing of the present invention on the surface that comes into contact with the fabric. This allows the adhesive layer to have excellent durability. Furthermore, during printing, the fabric can be stably fixed to the transport belt, and the printed record can be suitably released from the transport belt. Furthermore, because the adhesive layer can be formed using an aqueous pressure-sensitive adhesive composition for textile printing that contains water, there is no need to use an organic solvent in the aqueous pressure-sensitive adhesive composition for textile printing, and there is no need to consider problems associated with using organic solvents, more specifically, restrictions on the surrounding environment and environmental impact due to the evaporation of organic solvents.

[0087] The textile printing apparatus of the present invention includes the transport belt of the present invention and an inkjet head having nozzles for ejecting ink onto a fabric being transported by the transport belt. This allows the adhesive layer to have excellent durability. Furthermore, during printing, the fabric can be stably fixed to the transport belt, and the printed record can be suitably peeled from the transport belt. Furthermore, because the adhesive layer can be formed using an aqueous adhesive composition for textile printing containing water, there is no need to use an organic solvent in the aqueous adhesive composition for textile printing. This eliminates the need to consider problems associated with the use of organic solvents, more specifically, the constraints on the surrounding environment and the environmental impact caused by the evaporation of organic solvents.

[0088] Hereinafter, more specific embodiments of the transport belt and the textile printing apparatus of the present invention will be described with reference to the drawings.

[0089] Fig. 1 is a schematic diagram of a printing apparatus according to an embodiment of the present invention. Fig. 2 is a diagram showing a state in which a conveying device provided in the printing apparatus shown in Fig. 1 is performing a leveling process. Fig. 3 is a flowchart for explaining an example of a method for forming an adhesive layer.

[0090] For ease of explanation, in the following, in Figures 1 and 2, the x-axis, y-axis, and z-axis are shown as three mutually orthogonal axes. The x-axis is an axis along one of the horizontal directions (the width direction of the conveyor belt), the y-axis is an axis along the horizontal direction and perpendicular to the x-axis (the running direction of the conveyor belt), and the z-axis is an axis along the vertical direction (the up-down direction in the figure). In addition, the tip side of each arrow shown in the figure is referred to as the "positive side (+ side)" and the base side is referred to as the "negative side (- side)." In addition, the upper side of Figures 1 and 2 is referred to as "top" or "upper," and the lower side is referred to as "bottom" or "lower."

[0091] As shown in Figures 1 and 2, the textile printing apparatus 1 includes a conveying device 2 having a conveying belt 21 for conveying the fabric W, a payout device 3 for paying out a long length of the fabric W wound in a roll, a winding device 4 for winding up the printed fabric W, a printing section 5 for applying ink onto the fabric W being conveyed by the conveying belt 21 to perform printing, and an ink drying section 6 for drying the ink on the fabric W.

[0092] In this embodiment, the direction perpendicular to the conveying direction of the fabric W is the x-axis direction, the direction parallel to the conveying direction is the y-axis direction, and the direction perpendicular to the x-axis and y-axis directions is the z-axis direction.

[0093] The fabric W can be a woven fabric, knitted fabric, nonwoven fabric, or the like made of natural fibers such as cotton, silk, or wool, chemical fibers such as nylon, or composite fibers that are a mixture of these. The fabric W may also be clothing or other clothing products. Examples of clothing and other clothing products include sewn T-shirts, handkerchiefs, scarves, towels, carrier bags, cloth bags, curtains, sheets, bed covers, and other furniture, as well as fabrics that exist as parts before and after cutting.

[0094] The conveying device 2 has a driving roller 22 and a driven roller 23 arranged at a distance from each other in the y-axis direction, a conveying belt 21 stretched between the driving roller 22 and the driven roller 23 and supporting the fabric W on its upper surface (support surface), and tensioners 24, 25 that apply tension to the fabric W between the driving roller 22 and the driven roller 23.

[0095] A motor (not shown) is connected to the driving roller 22, and the driving roller 22 can be rotated by the operation of the motor. The rotational force of the driving roller 22 is transmitted to the driven roller 23 via the conveyor belt 21, and the driven roller 23 can rotate in conjunction with the driving roller 22.

[0096] The conveyor belt 21 is an endless belt having an adhesive layer formed on its front surface. A portion of the fabric W is adhesively fixed to this adhesive layer, and the fabric W is conveyed in the + direction of the y axis. During this conveyance, the fabric W is subjected to a desired printing. After printing, the fabric W is peeled off from the conveyor belt 21. The adhesive layer is formed by supplying a coating liquid 100 from a coating liquid supply unit 8, as shown in FIG. 2. The surface of the conveyor belt 21 that comes into contact with the fabric W is a coating surface 210 on which the coating liquid 100 is applied. The coating liquid 100 is the aqueous adhesive composition for textile printing of the present invention described above.

[0097] Similar to the driving roller 22 and the driven roller 23, the tensioners 24 and 25 are also arranged spaced apart from each other in the y-axis direction.

[0098] Tensioner 24 can sandwich fabric W together with conveyor belt 21 between it and drive roller 22, and tensioner 25 can sandwich fabric W together with conveyor belt 21 between it and driven roller 23. As a result, fabric W, to which an appropriate tension is applied by tensioners 24 and 25, is adhesively fixed to conveyor belt 21 while being tensioned, and conveyed. In this state, the occurrence of, for example, wrinkles and sagging of fabric W during conveyance is reduced, and therefore, when printing is performed, the printing can be performed appropriately and with high quality.

[0099] As shown in Figure 1, the unwinding device 3 is disposed upstream of the conveying device 2 in the feed direction of the fabric W, i.e., on the - side in the y-axis direction. The unwinding device 3 has a unwinding roller (unwinding reel) 31 around which the fabric W is wound in a roll and which unwinds the fabric W, and a tensioner 32 which applies tension to the fabric W between the unwinding roller 31 and the conveying device 2. A motor (not shown) is connected to the unwinding roller 31, and the unwinding roller 31 can be rotated by the operation of the motor.

[0100] The winding device 4 is disposed downstream of the driven roller 23 in the feed direction of the fabric W, i.e., on the + side in the y-axis direction, relative to the conveying device 2. The winding device 4 has a winding roller 41 that winds the fabric W into a roll, and tensioners 42, 43, and 44 that apply tension to the fabric W between the winding roller 41 and the conveying device 2. A motor (not shown) is connected to the winding roller 41, and the winding roller 41 can be rotated by operation of the motor. The tensioners 42, 43, and 44 are disposed in this order at intervals in a direction away from the winding roller 41.

[0101] The printing unit 5 includes a carriage unit 52 having a plurality of inkjet heads 51 that eject ink toward the fabric W to perform recording by printing, and an X-axis table (not shown) that supports the carriage unit 52 so that it can move in the x-axis direction. Each inkjet head 51 includes, for example, a head body formed with an internal head flow path that is filled with ink, and a number of nozzle groups each having an opening.

[0102] The head body is provided with piezoelectric elements (piezoelectric bodies) corresponding to the respective ejection nozzles, and when a voltage is applied to the piezoelectric elements, ink is ejected as droplets from the nozzles.

[0103] When not ejecting ink, the inkjet head 51 waits at a standby position that is positioned away from the fabric W (transport belt 21) in the x-axis direction when viewed from the z-axis direction.

[0104] In the textile printing device 1, the fabric W fed by the feeding device 3 is intermittently fed in the positive direction of the y axis while being adhesively fixed by the conveyor belt 21, and ink is ejected from the nozzle group onto the fixed fabric W while the carriage unit 52 is reciprocated in the x axis direction. In this way, a desired image pattern is formed and printed on the fabric W. The image pattern may be printed in multiple colors or in a single color.

[0105] The inks contain water as a solvent and dyes or pigments as colorants, and come in four colors, for example, cyan (C), magenta (M), yellow (Y), and black (K). Each color of ink is ejected independently from the inkjet head 51.

[0106] As shown in Figure 1, the ink drying unit 6 is located downstream of the printing unit 5 in the conveying direction of the fabric W, i.e., on the +y-axis direction side, between the conveying device 2 and the winding roller 41 of the winding device 4.

[0107] The ink drying unit 6 has a chamber 61 and a coil 62, which is a heat source (heater), arranged inside the chamber 61. The coil 62 is made of, for example, nichrome wire, and is configured as a heating element that generates heat when power is supplied. The heat generated by the coil 62 can dry the ink on the fabric W passing through the chamber 61.

[0108] The textile printing apparatus 1 has a control unit 15 that controls the operation of each part of the textile printing apparatus 1 or the transport device 2. That is, the control unit 15 controls the drive roller 22, the delivery roller 31, the take-up roller 41, the inkjet head 51, the carriage unit 52, the coil 62, the liquid supply pump 83, the coil 11, etc., so that they are driven at desired timing and under desired conditions. More specifically, the motor for the drive roller 22, the motor for the delivery roller 31, the motor for the take-up roller 41, the inkjet head 51, the carriage unit 52, the coil 62, the liquid supply pump 83, and the coil 11 are each electrically connected to a power supply unit (not shown), and the control unit 15 controls the conditions of electricity supply from the power supply unit to each of these parts, driving each of these parts at desired timing and under desired conditions (speed, temperature, etc.).

[0109] The control unit 15 is configured with a semiconductor integrated circuit and includes an arithmetic processing unit, a control signal transmitting / receiving unit, and a memory unit. The memory unit stores programs for executing the operations of the above units, information on operating conditions, etc.

[0110] In such a textile printing apparatus 1, when printing is not being performed on the fabric W, an aqueous coating liquid 100 is periodically supplied onto the conveyor belt 21 to form an adhesive layer. That is, in the textile printing apparatus 1, the coating liquid supply section 8, blade 9, and adhesive drying section 10 provided in the conveyor device 2 are operated as described below, thereby forming a coating film 105 of the coating liquid 100 and an adhesive layer obtained by drying the coating film 105 on the surface (coating surface 210) of the conveyor belt 21 facing the fabric W.

[0111] Next, the transport device 2 will be described. 1 and 2, the conveying device 2 includes a conveying belt 21, a coating liquid supplying section 8 that supplies a coating liquid 100 to a coating surface 210 on the fabric W side of the conveying belt 21, a blade 9 that levels the coating liquid 100 supplied to the coating surface 210, and an adhesive drying section 10 that dries a coating film 105 obtained by passing through the blade 9. The coating liquid supplying section 8, the blade 9, and the adhesive drying section 10 may each be incorporated into the conveying device 2, or may be configured to be detachable.

[0112] The coating liquid supply unit 8 has a storage section 81 that stores the coating liquid 100, a liquid delivery pipe 82 that delivers the coating liquid 100 from the storage section 81 to the vicinity of the coating surface 210, and a liquid delivery pump 83 provided midway along the liquid delivery pipe 82, and these components are used to perform the supply process shown in Figure 3.

[0113] The storage section 81 used in the supply process is composed of a hard or flexible container capable of storing the coating liquid 100, and by operating the liquid delivery pump 83, the coating liquid 100 in the storage section 81 is discharged from the outlet 811, delivered through the liquid delivery pipe 82, and ejected and supplied toward the coating surface 210 from the other end 822 of the liquid delivery pipe 82.

[0114] In this embodiment, when the coating liquid supply unit 8 supplies the coating liquid 100, the conveyor belt 21 is continuously driven to rotate and run. In this case, the running speed of the conveyor belt 21 is constant. This makes it possible to continuously change the area on the coating surface 210 to which the coating liquid 100 is supplied while supplying the coating liquid 100. Furthermore, continuous leveling can also be achieved in the leveling step described below.

[0115] The running speed of the conveyor belt 21 in the supplying step and the leveling step described later, i.e., when supplying and leveling the coating liquid 100, is not particularly limited, but is preferably 4 mm / sec or more and 67 mm / sec or less, and more preferably 8 mm / sec or more and 33 mm / sec or less. By setting the running speed in this range, the coating liquid 100 can be applied quickly and a more uniform and good coating film 105 can be obtained.

[0116] In the present invention, the conveyor belt 21 may be configured to be rotated intermittently. Furthermore, the conveyor belt 21 may be configured to be rotated at any timing and at any speed.

[0117] The reservoir 81 has a discharge port 811 for discharging the coating liquid 100 stored therein. One end 821 of a liquid supply pipe 82 is connected to the discharge port 811. The liquid supply pipe 82 transfers the coating liquid 100 to the vicinity of the coating surface 210. The other end 822 of the liquid supply pipe 82 is located above the coating surface 210 of the conveyor belt 21 and upstream of the printing unit 5 (the - side in the y-axis direction). Therefore, the coating liquid 100 discharged from the other end 822 of the liquid supply pipe 82 is dripped or sprayed at a position on the coating surface 210 of the conveyor belt 21 that is offset to the - side in the y-axis direction, i.e., a position offset toward the drive roller 22.

[0118] The other end 822 of the liquid supply pipe 82 branches into multiple branches (not shown). The branched flow paths are arranged side by side along the x-axis direction, i.e., along the width direction of the conveyor belt 21. This allows the coating liquid 100 to be supplied evenly (without excess or deficiency) to the required area of ​​the coating surface 210. The other end 822 of the liquid supply pipe 82 may be provided with a nozzle, an orifice, or the like.

[0119] As described above, the conveying device 2 has the liquid supply pipe 82 connected to the discharge port 811 and transporting the coating liquid 100 to the coating surface 210. This increases the degree of freedom in the installation position of the storage unit 81. Note that the liquid supply pipe 82 may be omitted, and the liquid may be supplied directly from the discharge port 811 to the coating surface 210 of the conveyor belt 21. In this case, the discharge port 811 is installed facing downward.

[0120] The supply amount per unit time of the coating liquid 100 supplied from the liquid supply pipe 82 onto the coating surface 210, i.e., the total supply amount of each branch flow path (hereinafter simply referred to as "supply amount"), is not particularly limited, but is preferably 15 mL / min to 67 mL / min, more preferably 15 mL / min to 35 mL / min. By setting the supply amount in this range, the coating liquid 100 can be applied quickly, and the leveling in the leveling step described below can be performed more uniformly and satisfactorily.

[0121] The coating liquid supply unit 8 may be configured to supply the coating liquid 100 continuously or intermittently.

[0122] In this embodiment, the coating liquid 100 is supplied by operating the liquid supply pump 83 provided in the liquid supply pipe 82, but the present invention is not limited to this.

[0123] For example, the configuration may be such that storage section 81 is formed from a flexible container, and has a pressurizing section that pressurizes storage section 81 from the outside, and storage section 81 is pressurized by the pressurizing section to push coating liquid 100 in storage section 81 out of outlet 811, sent through liquid sending tube 82, and discharged from the other end 822 to be supplied to coating surface 210. In this case, examples of the pressurizing section include one configured to pressurize storage section 81 by air pressure, and one configured to physically pressurize storage section 81 by a member such as a pressure plate or pressure roller.

[0124] Alternatively, the coating liquid 100 in the reservoir 81 may be supplied to the coating surface 210 by free fall via the liquid supply pipe 82.

[0125] The blade 9 levels the coating liquid 100 supplied to the coating surface 210 of the moving conveyor belt 21 to a uniform thickness. Leveling the coating liquid 100 applied to the coating surface 210 uniformly with the blade 9 is the leveling step shown in FIG.

[0126] In this embodiment, the coating process of coating the coating liquid 100 onto the coating surface 210 includes the supplying process and the leveling process.

[0127] The blade 9 used in the leveling process has an elongated shape extending in the width direction of the conveyor belt 21. The blade 9 is fixed in a state of being suspended above the conveyor belt 21 by a support part (not shown).

[0128] The blade 9 is provided between the other end 822 of the liquid feed tube 82 and the printing unit 5, that is, downstream of the other end 822 of the liquid feed tube 82 (positive side in the y-axis direction).

[0129] The blade 9 is provided with its lower end, i.e., the end on the negative side in the z-axis direction, spaced a predetermined distance G from the coating surface 210. This distance G is an important factor in determining the thickness of the coating liquid 100, i.e., the coating film 105, after the leveling process, and is particularly important in determining the film thickness of the resulting adhesive layer. The distance G is determined appropriately depending on various conditions, such as the viscosity of the coating liquid 100, the supply amount, and the adhesive strength of the desired adhesive layer. By adjusting the distance to match at least one, particularly two or three, of the viscosity of the coating liquid 100, the supply amount, and the adhesive strength of the adhesive layer, a coating film 105 of more uniform thickness can be formed in the leveling process.

[0130] In this way, the blade 9 extends in the width direction of the conveyor belt 21, and is spaced a predetermined distance G from the conveyor belt 21 when leveling the coating liquid 100. This allows the coating liquid 100 to be more uniformly leveled across the entire width of the conveyor belt 21 during the leveling process. In addition, because the blade 9 does not come into contact with the coating surface 210 of the conveyor belt 21, damage to the conveyor belt 21 by the blade 9 can be prevented.

[0131] When leveling the coating liquid 100, the blade 9 may be in contact with the conveyor belt 21 all the time or at appropriate times.

[0132] The coating liquid 100 supplied on the coating surface 210 in the supply process is transported to the +y-axis direction by the movement of the conveyor belt 21, and is leveled as it passes through the gap between the coating surface 210 and the blade 9 by the distance G, making the thickness uniform.

[0133] The blade 9 only needs to be installed above the conveyor belt 21 when the smoothing process is being performed, and may be configured to be removable from the conveyor device 2 when the smoothing process is not being performed.

[0134] The length of the blade 9 in the width direction (x-axis direction) of the transport belt 21 is not particularly limited, but is preferably 50 cm or more and 300 cm or less, and more preferably 100 cm or more and 200 cm or less. This allows the length of the blade 9 in the width direction of the transport belt 21 to be equal to or longer than the width of the transport belt 21, regardless of the model of the textile printing apparatus 1 or the size of the transport belt 21. Therefore, the blade 9 can cover the entire area or effective region of the transport belt 21 in the width direction and level the coating liquid 100.

[0135] The blade 9 smoothes the coating liquid 100 while driving the conveyor belt 21 to run, and the running speed of the conveyor belt 21 when smoothing the coating liquid 100 is substantially the same as the running speed of the conveyor belt 21 during printing. This makes it easy to control the running speed of the conveyor belt 21.

[0136] Here, "substantially the same" is a concept that includes not only cases where there is no difference between the two traveling speeds, but also cases where there is a slight difference between the two traveling speeds, for example, when the average speed difference is within ±5%.

[0137] In the present invention, the running speed of the conveyor belt 21 during printing may be different from the running speed of the conveyor belt 21 during leveling of the coating liquid 100. In other words, the running speed of the conveyor belt 21 may be appropriately changed between when forming the coating film 105 and when printing.

[0138] As shown in FIG. 1, the adhesive drying section 10 is a section where the drying step shown in FIG.

[0139] The adhesive drying unit 10 has a coil 11, which is a heat source (heater). The coil 11 is made of, for example, nichrome wire, and is a heating element that generates heat when power is supplied. The heat generated by the coil 11 can adequately dry the coating film 105 of the coating liquid 100 that has been applied to the coating surface 210 and leveled by the blade 9.

[0140] The position of the adhesive drying unit 10 is not limited to the illustrated configuration, and the configuration of the adhesive drying unit 10 is not limited to the illustrated configuration either.

[0141] In addition, in the present embodiment, the coating liquid 100 is applied once to the coating surface 210 of the conveyor belt 21, but this is not limiting, and the coating may be performed twice or three times. That is, after the supplying step, the leveling step, and the drying step of the coating liquid 100 are performed, these steps may be repeated multiple times.

[0142] The application step may be performed by using another device or by an operator applying the coating liquid 100 using an applicator or the like. In this case, examples of the applicator include a brush and an application roller.

[0143] The coating step includes a leveling step in which the coating liquid 100 is discharged from a nozzle and supplied to the coating surface 210, and the supplied coating liquid 100 is leveled using a blade 9. This allows the coating liquid 100 to be stably supplied to the coating surface 210. Furthermore, the supply of the coating liquid 100 to the coating surface 210 and the leveling of the coating liquid 100 can be carried out continuously.

[0144] In this embodiment, the smoothing step is performed using the blade 9, but the present invention is not limited to this, and the smoothing step may be performed by an operator using a tool such as a squeegee. Also, the smoothing step itself may be omitted.

[0145] The adhesive layer forming method includes a drying step in which the coating film 105 of the coating liquid 100 that has been leveled in the leveling step is heated and dried. This allows the coating film 105 to dry quickly and uniformly, and a homogeneous and excellent adhesive layer with no unevenness in adhesion can be formed on the coating surface 210 of the conveyor belt 21.

[0146] In this embodiment, the adhesive drying unit 10 that performs the drying step can forcibly or quickly dry the coating film 105, but is not limited to this, and the adhesive drying unit 10 may be one that dries at room temperature, or natural drying without applying airflow, etc. Furthermore, the conveying device 2 and the printing device 1 may not have the adhesive drying unit 10.

[0147] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these.

[0148] For example, the conveyor belt and the printing device of the present invention are not limited to the configurations shown in the drawings, and each part of the conveyor belt and the printing device can be replaced with any structure that can perform the same function. Also, any structure may be added. [Example]

[0149] Next, specific examples of the present invention will be described. [3] Preparation of aqueous adhesive composition for textile printing

[0150] Example 1 First, a (meth)acrylic resin was synthesized as follows. Specifically, 114 g of ion-exchanged water was added to a reactor equipped with a stirrer, reflux condenser, thermometer, nitrogen inlet tube, and dropping funnel, and the temperature was raised to a predetermined value. Then, 498 g of a monomer mixture consisting of 36.2% by mass of ethyl methacrylate, 23.2% by mass of butyl methacrylate, 4.5% by mass of butyl acrylate, and 36.1% by mass of 2-ethylhexyl acrylate, 79 g of ion-exchanged water, and 34 g of Emulgen 123P (Kao Corporation) as a nonionic surfactant were added to the reactor, and the mixture was stirred. A predetermined amount of a 2% by mass aqueous solution of ammonium persulfate, a persulfate salt, was added to the homogenized solution, and the mixture was heated at a predetermined temperature for a predetermined time. The mixture was then cooled to room temperature, and ion-exchanged water was added. Ammonia water was then added, and the mixture was further stirred to synthesize a (meth)acrylic resin.

[0151] Next, the (meth)acrylic resin synthesized as above was used to mix the components so as to obtain the composition shown in FIG. 4, thereby obtaining an aqueous pressure-sensitive adhesive composition for textile printing.

[0152] (Examples 2 to 6, Comparative Examples 1 to 5) Aqueous pressure-sensitive adhesive compositions for textile printing were prepared in the same manner as in Example 1, except that (meth)acrylic resins synthesized under different conditions were used and the amounts of each component were changed to obtain the compositions shown in Figure 4. In Example 4 and Comparative Examples 4 and 5, ammonia water was not used.

[0153] The compositions of the aqueous pressure-sensitive adhesive compositions for textile printing in each of the Examples and Comparative Examples are summarized in Figure 4. The "persulfate salt content" shown in Figure 4 was determined as follows. Specifically, 1 g of the aqueous pressure-sensitive adhesive composition for textile printing to be measured and 100 g of a 5% by weight sodium chloride aqueous solution were placed in a beaker and stirred at 500 rpm for 2 hours using a polytetrafluoroethylene-coated rotor. The resulting solution was then filtered and passed through a GL Chromatography Disc (Aqueous 25A, 0.45 μm) manufactured by GL Sciences. 0.50 g of a 44% by weight potassium iodide aqueous solution was added to 5.0 g of the solution, and the mixture was stirred for 1 hour in the dark. Quantitative analysis was performed using a spectrophotometer (Hitachi High-Technologies Corporation, Model U-3900H) to measure absorbance at a wavelength of 350 nm, thereby determining the "persulfate salt content." The "monomer content" and "alcohol compound content" shown in Figure 4 were determined as follows. Specifically, 1 g of the aqueous adhesive composition for textile printing to be measured, 100 g of a 5% by weight aqueous sodium chloride solution, and 10 g of tetrahydrofuran were placed in a beaker and stirred at 500 rpm for 1 hour using a rotor coated with polytetrafluoroethylene. The resulting liquid was then quantified using a gas chromatograph (Shimadzu Corporation, GC2014) with an FID detector and a Chemicals Evaluation and Research Institute, Japan G-300 column to determine the "monomer content" and "alcohol compound content." The pH values ​​shown in Figure 4 were measured at 23°C using a benchtop pH meter (HORIBA Corporation, F72S) by immersing a probe in the aqueous adhesive composition for textile printing for 3 minutes.

[0154] [4] Formation of adhesive layer A printing apparatus as shown in Figure 1 was prepared, and in an environment of 23°C, an aqueous pressure-sensitive adhesive composition for printing was discharged from the coating liquid supply unit onto an endless belt of a digital printing machine ML8000 manufactured by Seiko Epson Corporation, smoothed with a blade, coated to a thickness of 0.2 mm, and dried under conditions of 50% humidity, 23°C, and 8 hours to form an adhesive layer.

[0155] [5] Evaluation [5-1] Evaluation of aqueous adhesive compositions for textile printing The aqueous pressure-sensitive adhesive compositions for textile printing according to the above-mentioned respective Examples and Comparative Examples were evaluated as follows.

[0156] [5-1-1] Storage stability The aqueous pressure-sensitive adhesive composition for textile printing was placed in a 100 mL polyethylene pouch, welded and sealed, and left in a thermostatic chamber at 60°C for 7 days. The state of the pouch was then visually observed and evaluated according to the following criteria. ○: No change in appearance is observed. ×: Aggregates were observed.

[0157] [5-1-2] Odor Using a portable odor sensor min iXP-329m manufactured by New Cosmos Electric Co., Ltd., 0.1 g of the aqueous adhesive composition for textile printing was placed in a 250 mL polyethylene container, the container was capped, and the container was opened after 3 minutes. The container was then allowed to stand for 2 minutes, and the average value was calculated and evaluated according to the following criteria. The higher this value, the stronger the odor. ○: The measurement value is less than 900. ×: The measured value is 900 or more.

[0158] [5-2] Evaluation of adhesive layer The adhesive layers according to the examples and comparative examples were evaluated as follows.

[0159] [5-2-1]Durability A wet nylon roller brush was pressed against the adhesive layer on the conveyor belt at 1.0 N / cm while rotating at 6 rpm. After 30 days, the rotation of the nylon brush was stopped and the condition of the adhesive layer was visually observed and evaluated according to the following criteria. O: No scratches are observed. △: Slight scratches are observed. ×: Significant irregularities are observed.

[0160] [5-2-2]Water resistance The conveyor belt provided with the adhesive layer was immersed in pure water at 23° C. for 20 minutes, then removed from the pure water, and the state of the adhesive layer was visually observed and evaluated according to the following criteria. ◯: No whitening occurred and it was transparent. △: Slight whitening occurred. ×: Significant whitening.

[0161] These results are summarized in FIG. As is clear from Fig. 5, excellent results were obtained in each of the Examples, whereas satisfactory results were not obtained in each of the Comparative Examples. [Explanation of symbols]

[0162] 1...textile printing device, 2...conveyor device, 3...feeding device, 4...winding device, 5...printing unit, 6...ink drying unit, 8...coating liquid supply unit, 9...blade, 10...adhesive drying unit, 11...coil, 15...control unit, 21...conveyor belt, 22...drive roller, 23...driven roller, 24...tensioner, 25...tensioner, 31...feed roller, 32...tensioner, 41...winding roller, 42...tensioner, 43...tensioner, 44...tensioner, 51...inkjet head, 52...carriage unit, 61...chamber, 62...coil, 81...storage unit, 82...liquid supply pipe, 83...liquid supply pump, 100...coating liquid, 105...coating film, 210...coated surface, 811...discharge port, 821...one end, 822...other end, G...distance, W...fabric

Claims

1. Contains water, a (meth)acrylic resin, and a persulfate, The aqueous pressure-sensitive adhesive composition for textile printing has a persulfate content of 100 ppm or more and 2000 ppm or less.

2. The aqueous pressure-sensitive adhesive composition for textile printing according to claim 1, further comprising 1000 ppm or less of an unpolymerized monomer of the same kind as a monomer constituting the (meth)acrylic resin.

3. The (meth)acrylic resin contains, as a constituent monomer, an ester compound of (meth)acrylic acid represented by the following formula (1): The aqueous pressure-sensitive adhesive composition for textile printing according to claim 1 or 2, further comprising an alcohol compound represented by the following formula (2) in a content of 1000 ppm or less: R １ -C(=CH ２ )-C(=O)-O-R ２ … (1) (In formula (1), R １ is H or CH ３ and R ２ is a hydrocarbon group. R ２ -OH … (2) (In formula (2), R ２ is a hydrocarbon group.

4. The aqueous pressure-sensitive adhesive composition for textile printing according to claim 1 or 2, which contains ammonium ions.

5. The aqueous pressure-sensitive adhesive composition for textile printing according to claim 1 or 2, wherein the persulfate comprises ammonium persulfate.

6. The aqueous pressure-sensitive adhesive composition for textile printing according to claim 1 or 2, wherein the pH of the aqueous pressure-sensitive adhesive composition for textile printing at 23°C is 7.5 or more and 9.0 or less.

7. A conveyor belt for conveying a fabric to be printed by textile printing, A conveyor belt, the conveyor belt having an adhesive layer formed using the aqueous adhesive composition for textile printing according to claim 1 or 2 on a surface that comes into contact with the fabric.

8. The conveyor belt according to claim 7; an inkjet head having nozzles that eject ink onto the fabric being transported by the transport belt.

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