Aqueous adhesive composition

Abstract

To provide an aqueous adhesive composition that achieves both an adhesive force of an adhesive layer and durability suppressing a decrease in adhesive force during brushing.SOLUTION: There is provided an aqueous adhesive composition for forming an adhesive layer of a fabric transport member of an ink jet textile printing apparatus including a transport mechanism that bonds a fabric to the adhesive layer formed at a surface of the fabric transport member to transport the fabric, a heating portion that heats the adhesive layer, a bonding portion that bonds the fabric to the heated adhesive layer, a recording portion that attaches an ink composition to the fabric bonded to the adhesive layer using an ink jet head, a peeling portion that peels off the recorded fabric from the adhesive layer, and a cleaning portion that cleans the adhesive layer from which the fabric is peeled off with a cleaning solution containing water. The aqueous adhesive composition includes: a (meth)acrylic resin; and water, in which when an adhesive force with which the fabric is peeled off from the adhesive layer cooled to 23°C after bonding the fabric to the adhesive layer heated to 33°C is represented by an adhesive force A (N / 50 mm) and an adhesive force with which the fabric is peeled off from the adhesive layer at 23°C after bonding the fabric to the adhesive layer at 23°C is represented by an adhesive force B (N / 50 mm), a change rate of adhesive force per unit temperature represented by (A-B) / (33°C-23°C) is 0.050 N / °C 50 mm or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an aqueous pressure-sensitive adhesive composition. [Background technology]

[0002] Inkjet recording methods are capable of recording high-resolution images with relatively simple equipment and have been rapidly developing in various fields. In the process, various studies have been conducted on ejection stability, etc. For example, Patent Document 1 discloses an image recording apparatus including: an endless belt having a heat-sensitive adhesive on its surface, which holds a recording medium by adhering it to the heat-sensitive adhesive and which is moved to transport the recording medium; an image forming unit which forms an image on the recording medium transported by the endless belt; a cleaning unit which is located downstream of the image forming unit in the recording medium transport direction and sprays cleaning liquid onto the heat-sensitive adhesive from which the recording medium has been peeled off to clean the heat-sensitive adhesive; a supply pipe which supplies the cleaning liquid to the cleaning unit; and a cleaning liquid heating unit which heats the cleaning liquid supplied to the cleaning unit, wherein the cleaning liquid heating unit heats the supply pipe in the vicinity of the cleaning unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-200120 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 discloses that a heat-sensitive adhesive material is heated to improve adhesion of a recording medium to the heat-sensitive adhesive material. However, the adhesive layer whose adhesiveness improves upon heating does not have sufficient durability against washing. [Means for solving the problem]

[0005] The aqueous adhesive composition of the present invention is a method for applying an ink composition to the adhesive layer of a fabric transporting member of an inkjet printing device, the method comprising: a transport mechanism for transporting a fabric by attaching the fabric to an adhesive layer formed on the surface of the fabric transporting member; a heating unit for heating the adhesive layer; an attaching unit for attaching the fabric to the heated adhesive layer; a recording unit for applying an ink composition to the fabric attached to the adhesive layer using an inkjet head; a peeling unit for peeling the fabric from the adhesive layer after recording; and a cleaning unit for cleaning the adhesive layer from which the fabric has been peeled with a cleaning liquid containing water. The aqueous adhesive composition comprises a (meth)acrylic resin and water, and when the adhesive strength when a fabric is attached to the adhesive layer heated to 33°C and then cooled to 23°C and the fabric is peeled from the adhesive layer is defined as adhesive strength A (N / 50mm), and the adhesive strength when the fabric is attached to the adhesive layer at 23°C and then peeled from the adhesive layer at 23°C is defined as adhesive strength B (N / 50mm), the rate of change in adhesive strength per unit temperature, expressed as (AB) / (33°C-23°C), is 0.050 N / °C·50mm or more.

[0006] The method for imparting tackiness of the present invention comprises a step of forming an adhesive layer from the aqueous adhesive composition on the surface of a fabric transport member of an inkjet textile printing device.

[0007] The inkjet textile printing device of the present invention includes a conveying mechanism that conveys a fabric by adhering it to an adhesive layer made of the aqueous adhesive composition and formed on the surface of a fabric conveying member; a heating unit that heats the adhesive layer; an adhering unit that adheres the fabric to the heated adhesive layer; a recording unit that applies an ink composition to the fabric adhered to the adhesive layer using an inkjet head; a peeling unit that peels the fabric from the adhesive layer after recording; and a cleaning unit that washes the adhesive layer from which the fabric has been peeled with a cleaning liquid containing water.

[0008] The fabric transport member of the ink-jet printing device of the present invention has an adhesive layer made of the aqueous adhesive composition on its surface.

[0009] The inkjet printing method of the present invention includes a conveying step of attaching a fabric to an adhesive layer made of the aqueous adhesive composition formed on the surface of a fabric conveying member of an inkjet printing device and conveying the fabric; a heating step of heating the adhesive layer; an attaching step of attaching the fabric to the heated adhesive layer; a recording step of applying an ink composition to the fabric attached to the adhesive layer using an inkjet head; a peeling step of peeling the fabric from the adhesive layer after recording; and a washing step of washing the adhesive layer from which the fabric has been peeled with a washing liquid containing water. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic cross-sectional view of an inkjet textile printing apparatus. [Figure 2] 1 is a table showing the constitution of (meth)acrylic resins. [Figure 3] 1 is a table showing examples and comparative examples. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail with reference to the drawings as necessary, but the present invention is not limited to this, and various modifications are possible without departing from the spirit of the present invention. In the drawings, the same elements are given the same reference numerals, and redundant explanations will be omitted. Furthermore, positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings unless otherwise specified. Furthermore, the dimensional ratios of the drawings are not limited to those shown in the drawings.

[0012] The term "(meth)acrylate" is a comprehensive expression that encompasses acrylate and methacrylate. The term "unit" as used herein, such as "structural unit" or "(meth)acrylate unit," refers to a repeating unit derived from a monomer when the monomer is polymerized to form a polymer.

[0013] 1. Water-based adhesive composition The aqueous adhesive composition according to the present embodiment is used to apply an ink composition to the adhesive layer of the fabric transporting member of an inkjet textile printing device, the ink composition being attached to the adhesive layer of the fabric transporting member of the ... The aqueous adhesive composition constituting the adhesive layer comprises a (meth)acrylic resin and water, and when the adhesive strength when a fabric is attached to the adhesive layer heated to 33°C and then cooled to 23°C and the fabric is peeled from the adhesive layer is defined as adhesive strength A (N / 50mm), and the adhesive strength when the fabric is attached to the adhesive layer at 23°C and then peeled from the adhesive layer at 23°C is defined as adhesive strength B (N / 50mm), the rate of change in adhesive strength per unit temperature, expressed as (AB) / (33°C-23°C), is 0.050 N / °C·50mm or more.

[0014] The aqueous adhesive composition of the present embodiment is a composition that forms an adhesive layer by being applied to a fabric conveying member and dried, and by having the above-mentioned configuration, it is possible to achieve both adhesive strength of the adhesive layer and durability that suppresses a decrease in adhesive strength during brushing. Below, each component contained in the aqueous adhesive composition will be described in detail.

[0015] 1.1. Adhesive properties In this embodiment, the adhesive strength when a fabric is attached to an adhesive layer heated to 33°C and then cooled to 23°C and peeled from the adhesive layer is defined as "adhesive strength A (N / 50mm)," and the adhesive strength when a fabric is attached to an adhesive layer at 23°C and then peeled from the adhesive layer at 23°C is defined as "adhesive strength B (N / 50mm)."

[0016] In this case, the rate of change in adhesive strength per unit temperature, expressed as (AB) / (33°C-23°C), in the aqueous pressure-sensitive adhesive composition is 0.050 N / °C·50 mm or more, and preferably 0.055 to 0.300 N / °C·50 mm, 0.058 to 0.250 N / °C·50 mm, 0.060 to 0.200 N / °C·50 mm, or 0.63 to 0.150 N / °C·50 mm. When the rate of change in adhesive strength per unit temperature is 0.050 N / °C·50 mm or more, the adhesive strength and durability of the adhesive layer tend to be further improved.

[0017] The adhesive strength B is preferably 0.1 to 4.0 N / 50 mm, 0.2 to 3.0 N / 50 mm, 0.3 to 2.5 N / 50 mm, or 0.5 to 2.0 N / 50 mm. When the adhesive strength A is within the above range, the adhesive strength and the durability of the adhesive layer tend to be further improved.

[0018] The adhesive strength A is preferably 0.1 to 5.0 N / 50 mm, 0.2 to 4.5 N / 50 mm, 0.3 to 4.0 N / 50 mm, 0.5 to 3.5 N / 50 mm, 1.0 to 3.0 N / 50 mm, or 1.5 to 3.0 N / 50 mm. When the adhesive strength B is within the above range, the adhesive strength and the durability of the adhesive layer tend to be further improved.

[0019] The adhesive strengths A and B, as well as the rate of change in adhesive strength per unit temperature, can be adjusted by the glass transition temperature of the (meth)acrylic resin used, or, when multiple (meth)acrylic resins are used, by the content or composition thereof.

[0020] The conditions for forming an adhesive layer, which are used to define the above-mentioned adhesive properties and the viscoelastic properties described below by applying and drying the aqueous adhesive composition, are as follows: First, the aqueous adhesive composition is applied to a glass substrate so that the adhesive layer is 200 μm thick, and then the adhesive layer is dried in a windless atmosphere at 23°C, followed by drying in a thermostatic chamber at 50°C for 30 minutes to form an adhesive layer. For adhesive strength measurement, a 50 mm wide piece of Italian cotton is attached to the adhesive layer formed as described above with a load of 1.0 kgf / 50 mm, and the 180-degree peel force is measured. The temperatures during attachment and peeling follow the definitions of adhesive strength A and B above.

[0021] 1.2. Viscoelastic properties The difference (G"23-G"33) between the loss modulus G"23 at 23°C and the loss modulus G"33 at 33°C of the adhesive layer made of the aqueous adhesive composition is preferably 1 x 10 3 ~15×10 3 Pa, 2 x 10 3 ~12.5×10 3 Pa, 3 x 10 3 ~10×10 3 Pa, 4 x 10 3 ~9×10 3 Pa. When the difference (G"23-G"33) is within the above range, the adhesive strength and durability of the adhesive layer tend to be further improved.

[0022] The loss modulus G″23 of the adhesive layer made of the aqueous adhesive composition at 23°C is preferably 5.0×10 3 ~75×10 3 Pa, 7.5 x 10 3 ~50×10 3 Pa, 10 x 10 3 ~35×10 3 Pa. The loss modulus G''23 is preferably greater than the loss modulus G''33. When the loss modulus G''23 is within the above range, the adhesive strength and durability of the adhesive layer tend to be further improved.

[0023] The loss modulus G″33 of the adhesive layer made of the aqueous adhesive composition at 33°C is preferably 2.5×10 3 ~50×10 3 Pa, 5.0 x 10 3 ~35×10 3 Pa, 7.5 x 10 3 ~25×10 3 Pa. When the loss modulus G''33 is within the above range, the adhesive strength and durability of the adhesive layer tend to be further improved.

[0024] The viscoelastic properties G"23 and G"33, as well as the difference between them (G"23 - G"33), can be adjusted by the structural units of the (meth)acrylic resin used, or, when multiple (meth)acrylic resins are used, by the contents or compositions thereof.

[0025] 1.3.(Meth)acrylic resin By including a (meth)acrylic resin, the adhesive layer formed on the fabric conveying member has improved adhesive strength and durability. The (meth)acrylic resin may be a water-soluble resin or a resin emulsion dispersed in an aqueous solvent. These are collectively referred to as a (meth)acrylic resin in this embodiment. Furthermore, the (meth)acrylic resin may be a copolymer of an allyl monomer in addition to a (meth)acrylate.

[0026] The (meth)acrylic resin is not particularly limited as long as it is a polymer obtained by polymerizing a (meth)acrylic monomer such as (meth)acrylic acid or a (meth)acrylic acid ester as one component. Examples include homopolymers obtained from (meth)acrylic monomers and copolymers of (meth)acrylic monomers with other monomers. More specific (meth)acrylic monomers are not particularly limited, but examples include (meth)acrylic monomers having an aliphatic group such as methyl methacrylate (MMA), ethyl methacrylate (EMA), butyl methacrylate (BMA), butyl acrylate (BA), and 2-ethylhexyl acrylate (2EHA); and (meth)acrylic monomers having an aromatic group such as styrene (St). Other monomers are not particularly limited, but examples include acrylamide and acrylonitrile.

[0027] The aqueous pressure-sensitive adhesive composition may contain a first (meth)acrylic resin having, as a structural unit, a (meth)acrylic monomer whose homopolymer has a glass transition temperature of 40° C. or higher, and may further contain a second (meth)acrylic resin having a glass transition temperature Tg2 higher than the glass transition temperature Tg1 of the first (meth)acrylic resin. By containing the first (meth)acrylic resin and the second (meth)acrylic resin having a different glass transition temperature Tg, adhesive strength and the effect of suppressing a decrease in adhesive strength during brushing tend to be further improved.

[0028] The glass transition temperature Tg1 of the first (meth)acrylic resin is preferably −70 to −15° C., or may be −65 to −20° C., −60 to −25° C., or −55 to −30° C. When the glass transition temperature Tg1 is within the above range, the decrease in adhesive strength during brushing tends to be further suppressed.

[0029] The glass transition temperature Tg2 of the second (meth)acrylic resin is preferably −30 to 5° C., or may be −25 to 0° C., −20 to −2.5° C., or −15 to −5° C. When the glass transition temperature Tg2 is within the above range, the adhesive strength tends to be further improved.

[0030] The difference |Tg1-Tg2| between the glass transition temperature Tg1 and the glass transition temperature Tg2 is preferably 10 to 50° C., or 15 to 45° C., or 20 to 40° C., or may be 25 to 35° C. When the difference |Tg1-Tg2| is within the above range, adhesive strength and the effect of suppressing a decrease in adhesive strength during brushing tend to be further improved.

[0031] In the present embodiment, the glass transition temperature can be measured by a conventionally known method such as differential scanning calorimetry (DSC). The glass transition temperature of the (meth)acrylic resin can be adjusted by the glass transition temperature of a homopolymer of the polymerizable compound used and the mass ratio of the polymerizable compound used.

[0032] The monomer contained in the first (meth)acrylic resin is not particularly limited, but preferably includes at least ethyl methacrylate, butyl methacrylate, butyl acrylate, and (meth)acrylic monomers having an aliphatic group such as 2-ethylhexyl acrylate, etc. Use of a first (meth)acrylic resin containing such a monomer tends to further improve adhesive strength and the effect of suppressing a decrease in adhesive strength during brushing.

[0033] The first (meth)acrylic resin preferably contains, as a constituent unit, a (meth)acrylic monomer whose homopolymer has a glass transition temperature of 40° C. or higher. When the first (meth)acrylic resin contains the above-mentioned monomer, the adhesive strength of the adhesive layer and the effect of suppressing a decrease in adhesive strength during brushing tend to be further improved.

[0034] The content of the (meth)acrylic monomer having a homopolymer glass transition temperature of 40° C. or higher is preferably 25 to 55% by mass, or may be 30 to 50% by mass, or 35 to 45% by mass, relative to the total amount of the first (meth)acrylic resin. When the content of the (meth)acrylic monomer having a homopolymer glass transition temperature of 40° C. or higher is within the above range, the adhesive strength of the adhesive layer and the effect of suppressing a decrease in adhesive strength during brushing tend to be further improved.

[0035] Examples of the monomer contained in the second (meth)acrylic resin include the same as those mentioned above, and are not particularly limited, but preferably include at least ethyl methacrylate, butyl methacrylate, butyl acrylate, and (meth)acrylic monomers having an aliphatic group such as 2-ethylhexyl acrylate. Use of a second (meth)acrylic resin containing the above monomers tends to further improve adhesive strength and the effect of suppressing a decrease in adhesive strength during brushing.

[0036] The content of the (meth)acrylic monomer having a homopolymer glass transition temperature of 40° C. or higher is preferably 2.5 to 20% by mass, or may be 5.0 to 15% by mass, or 7.5 to 10% by mass, relative to the total amount of the second (meth)acrylic resin. When the content of the (meth)acrylic monomer having a homopolymer glass transition temperature of 40° C. or higher is within the above range, the adhesive strength of the adhesive layer and the effect of suppressing a decrease in adhesive strength during brushing tend to be further improved.

[0037] The content of the first (meth)acrylic resin is preferably 50 to 85 mass %, 53 to 82 mass %, 55 to 75 mass %, or 60 to 70 mass % relative to the total amount of the first (meth)acrylic resin and the second (meth)acrylic resin. When the content of the first (meth)acrylic resin is within the above range, the adhesive strength of the adhesive layer and the effect of suppressing a decrease in adhesive strength during brushing tend to be further improved.

[0038] The content of the second (meth)acrylic resin is preferably 15 to 50 mass%, 18 to 47 mass%, 25 to 45 mass%, or 30 to 40 mass% relative to the total amount of the first (meth)acrylic resin and the second (meth)acrylic resin. When the content of the second (meth)acrylic resin is within the above range, the adhesive strength of the adhesive layer and the effect of suppressing a decrease in adhesive strength during brushing tend to be further improved.

[0039] The content of the (meth)acrylic resin is preferably 70 to 100 mass%, 80 to 99 mass%, or 90 to 98 mass% relative to the total amount of the aqueous pressure-sensitive adhesive composition. When the content of the (meth)acrylic resin is within the above range, the adhesive strength and durability of the resulting pressure-sensitive adhesive layer tend to be further improved. Note that the content relative to the total amount of the aqueous pressure-sensitive adhesive composition refers to the amount of solids.

[0040] 1.2. pH adjusters The pH adjuster is not particularly limited, but examples thereof include inorganic acids (e.g., sulfuric acid, hydrochloric acid, nitric acid, etc.), inorganic bases (e.g., lithium hydroxide, sodium hydroxide, potassium hydroxide, ammonia, ammonium salts, etc.), organic bases (triethanolamine, diethanolamine, monoethanolamine, tripropanolamine), and organic acids (e.g., adipic acid, citric acid, succinic acid, etc.).

[0041] Among these, ammonia or ammonium salts are preferred. By using such a pH adjuster, ammonia volatilizes when forming an adhesive layer from the aqueous adhesive composition, and the (meth)acrylic resins become more easily adhered to each other, forming a coating film that is less susceptible to water penetration. As a result, the adhesive layer formed on the fabric conveying member has improved adhesive strength durability and water resistance, and the adhesiveness tends to be better maintained over a wide temperature range.

[0042] The content of the pH adjuster is preferably 0.01 to 1.50 mass%, 0.02 to 1.00 mass%, 0.03 to 0.50 mass%, or 0.04 to 0.30 mass%, relative to the total amount of the aqueous pressure-sensitive adhesive composition. When the content of the pH adjuster is within the above range, the peelability, adhesiveness, and washing resistance of the pressure-sensitive adhesive layer tend to be further improved.

[0043] 1.3.Water An aqueous pressure-sensitive adhesive composition may be used to form the pressure-sensitive adhesive layer. The water content in the aqueous pressure-sensitive adhesive composition is preferably 30 to 80 mass%, 35 to 70 mass%, or 40 to 60 mass%, relative to the total amount of the aqueous pressure-sensitive adhesive composition. The aqueous pressure-sensitive adhesive composition can be formed into a pressure-sensitive adhesive layer by drying it, for example, under conditions of 25% humidity, 50°C, and 30 minutes, and the water content at this time may be 8 mass% or less, 4 mass% or less, or 2 mass% or less.

[0044] 1.4.Surfactants The aqueous pressure-sensitive adhesive composition may contain a surfactant. The surfactant is not particularly limited, but examples thereof include anionic surfactants, nonionic surfactants, and cationic surfactants.

[0045] 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 sulfosuccinates, diethylhexyl cyrsulfosuccinates, and dioctyl sulfosuccinates.

[0046] 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, alkyl diethanolamides, and alkyl amine oxides.

[0047] 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.

[0048] In this embodiment, among these, nonionic surfactants are preferred, and more specifically, alkyl ether-based nonionic surfactants are preferred. Use of such surfactants tends to maintain durability and water resistance.

[0049] The content of the surfactant is preferably 0.1 to 4 mass %, 0.3 to 3 mass %, or 0.5 to 2 mass parts relative to 100 mass parts of the (meth)acrylic resin.

[0050] 1.5. Tackifiers The aqueous pressure-sensitive adhesive composition preferably contains no or a small amount of a tackifier. When the aqueous pressure-sensitive adhesive composition contains no or a small amount of a tackifier, the adhesive strength of the adhesive layer and the effect of suppressing the decrease in adhesive strength during brushing tend to be more sustained. Typical examples of such tackifiers include rosin-based compounds, terpene-based compounds, and hydrocarbon resins. More specifically, examples of the compound include rosin-based 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-based 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 (monoterpene, diterpene, triterpene, polyperene, 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.

[0051] It is preferable that the composition does not contain a tackifier. However, if a tackifier is contained, the content thereof is preferably 5.0 mass% or less, 4.0 mass% or less, 3.0 mass% or less, 2.0 mass% or less, or 1.0 mass% or less, based on the total amount of the aqueous pressure-sensitive adhesive composition. When the content of the tackifier is within the above range, the adhesive strength of the resulting adhesive layer and the effect of suppressing a decrease in adhesive strength during brushing tend to be more sustained. From the same viewpoint, the total content of compounds selected from the group consisting of rosin-based compounds, terpene-based compounds, and hydrocarbon resins is also preferably within the above range.

[0052] The content of the tackifier relative to the total amount of the adhesive layer described below is also preferably 5.0 mass% or less, 4.0 mass% or less, 3.0 mass% or less, 2.0 mass% or less, or 1.0 mass% or less.

[0053] 1.6. Organic Solvents From the viewpoint of reducing the environmental load and the influence on the human body, the aqueous pressure-sensitive adhesive composition of the present embodiment preferably does not contain an organic solvent. Furthermore, when an organic solvent is contained, the content of the organic solvent is preferably 5.0 mass % or less, 2.5 mass % or less, 1.0 mass % or less, 0.6 mass % or less, or 0.2 mass % or less, based on the total amount of the aqueous pressure-sensitive adhesive composition. This reduces the environmental load and VOCs (volatile organic compounds) when the aqueous pressure-sensitive adhesive composition is used, which tends to further improve the working environment.

[0054] The content of the organic solvent relative to the total amount of the adhesive layer described below is also preferably 5.0 mass % or less, 2.5 mass % or less, 1.0 mass % or less, 0.6 mass % or less, or 0.2 mass % or less.

[0055] 1.7.Colorants The aqueous pressure-sensitive adhesive composition of this embodiment preferably does not contain a colorant. Furthermore, if a colorant is contained, the content of the colorant is preferably 1.0 mass % or less, 0.5 mass % or less, or 0.3 mass % or less, based on the total amount of the aqueous pressure-sensitive adhesive composition. This clearly distinguishes the aqueous pressure-sensitive adhesive composition of this embodiment from compositions intended for coloring ink compositions, textile printing pastes, paints, and the like.

[0056] The content of the coloring material relative to the total amount of the adhesive layer, which will be described later, is also preferably 1.0% by mass or less, 0.5% by mass or less, or 0.3% by mass or less.

[0057] 2. Adhesive layer The adhesive layer is a dried aqueous adhesive composition and may have the same composition as the aqueous adhesive composition, except for the water content of the dried part. As described above, the water content of the adhesive layer is preferably 8% by mass or less, 4% by mass or less, or 2% by mass or less.

[0058] Furthermore, when the aqueous pressure-sensitive adhesive composition contains a volatile component other than water, the composition of the dried component may also differ between the pressure-sensitive adhesive layer and the aqueous pressure-sensitive adhesive composition. Specifically, when ammonia is used as a pH adjuster, the amount of pH adjuster remaining in the pressure-sensitive adhesive layer may be relatively smaller than that in the aqueous pressure-sensitive adhesive composition.

[0059] The adhesive layer may also have the adhesive properties and viscoelastic properties described for the aqueous adhesive composition.

[0060] 3.Method of providing adhesiveness The method for imparting tackiness of this embodiment includes a step of adhering the aqueous pressure-sensitive adhesive composition to the surface of a fabric transport member of an inkjet textile printing device to form a pressure-sensitive adhesive layer.

[0061] The step of forming the adhesive layer is a step of applying the aqueous adhesive composition to the surface of the fabric conveying member to form an adhesive layer. The method of applying the aqueous adhesive composition to the fabric conveying member is not particularly limited, but the aqueous adhesive composition may be applied uniformly to the entire surface of the fabric conveying member using a blade or the like, or may be applied to a part of the surface of the fabric conveying member in a predetermined pattern.

[0062] In the adhesive layer-forming step, the aqueous adhesive composition may be dried to form the adhesive layer. The drying temperature is preferably 10 to 60°C, and more preferably 20 to 40°C. The drying time is preferably 1 to 24 hours, and more preferably 2 to 8 hours. This tends to further improve the water resistance and mechanical strength of the resulting adhesive layer.

[0063] 4. Inkjet printing equipment The inkjet textile printing apparatus of this embodiment has a conveying mechanism that conveys a fabric by attaching it to an adhesive layer made of the above-mentioned aqueous adhesive composition formed on the surface of a fabric conveying member, a heating unit that heats the adhesive layer, an attachment unit that attaches the fabric to the heated adhesive layer, a recording unit that uses an inkjet head to apply an ink composition to the fabric attached to the adhesive layer, a peeling unit that peels the fabric from the adhesive layer after recording, and a cleaning unit that washes the adhesive layer from which the fabric has been peeled with a cleaning liquid containing water.

[0064] An inkjet textile printing apparatus 100 of this embodiment will be described with reference to Figure 1. Figure 1 is an overall configuration diagram of the inkjet textile printing apparatus 100 including a conveying device 200 of this embodiment. In Figure 1, arrows a and b indicate the conveying direction of the recording medium 300. Arrows c and d indicate the rotation direction of the fabric conveying member 210. Arrows e and f indicate the rotation direction of the conveying rollers 221 and 222.

[0065] The inkjet printing apparatus 100 may have a conveying device 200 for adhering a recording medium to a surface and conveying it, recording medium conveying rollers 111 and 112, and a recording unit 120. A recording medium 300 coming from the direction a is pressed against a fabric conveying member 210 by the recording medium conveying roller 111 (adhering unit), and the recording medium 300 is adhered to the surface of the fabric conveying member 210.

[0066] With the recording medium 300 stuck to the surface of the fabric conveying member 210, the conveying device 200 conveys the recording medium 300 directly below the recording unit 120, and the recording unit 120 records on the recording medium 300. Then, the recording medium conveying member 210 and the recording medium 300 are separated at the recording medium conveying roller 112 (separating unit).

[0067] The recording unit 120 may eject an ink composition or the like by an inkjet method. In this embodiment, it is assumed that an inkjet head is used for the recording unit 120 and that printing is performed on a textile fabric as the recording medium 300, but the present invention is not limited to this.

[0068] The conveying device 200 may include a pair of conveying rollers 221 and 222 , a fabric conveying member 210 , a drive motor 230 , a control device 240 , a cleaning unit 250 , a removing member 260 , and a heating unit 270 .

[0069] The transport rollers 221 and 222 are rollers for transporting the fabric transport member 210 in a certain direction. The fabric transport member 210 may be a belt member having an adhesive layer on its surface, and is provided around the transport rollers 221 and 222. The fabric transport member 210 transports the recording medium in the direction of arrow c as the transport rollers 221 and 222 are rotated by a drive motor 230. The control device 240 may control either or both of the transport device 200 and the inkjet printing device 100.

[0070] The cleaning unit 250 cleans the surface of the fabric transport member 210 that has been separated from the recording medium 300. The cleaning unit 250 cleans the components of the recording medium 300 and the printing colorant that have adhered to the fabric transport member 210 during printing. The cleaning unit 250 may include a pump (not shown), a water sprinkler port, and a water sprinkler pipe.

[0071] The removing member 260 removes water that has adhered to the fabric conveying member 210 by the cleaning unit 250. The removing member 260 is not particularly limited, but may be, for example, a blade. The material of the blade is preferably an elastic material. Furthermore, polyurethane is preferable from the viewpoint of abrasion resistance. The contact portion with the fabric conveying member 210 may have a rectangular cross section, or may have a shape with an obliquely cut-off tip.

[0072] The heating section 270 may be provided downstream of the cleaning section 250 and upstream of the recording medium conveying roller 111 that performs the laminating step. When the adhesive layer is heated by the heating section 270, the (meth)acrylic resin that constitutes the adhesive layer tends to soften and the adhesive strength tends to be further improved.

[0073] An elastic material is preferable for the fabric conveying member 210. A heater (not shown) may be installed to warm the fabric conveying member 210. In the process of washing the fabric conveying member 210, a water receiving section (not shown) for receiving washing water, a brush (not shown) for cleaning the fabric conveying member 210, a sponge (not shown), etc. may be used.

[0074] The recording medium 300 may be a fabric made of natural or synthetic fibers such as silk, cotton, wool, nylon, polyester, rayon, etc. The fabric may also be woven, knitted, or nonwoven.

[0075] 4. Fabric transport member for inkjet printing equipment The fabric transporting member of the inkjet printing device of this embodiment has an adhesive layer derived from the aqueous adhesive composition on its surface. The fabric transporting member is not particularly limited, but is preferably made of, for example, an elastic material, and particularly preferably contains a urethane resin. By using the aqueous adhesive composition described above for such a fabric transporting member, the adhesion between the adhesive layer and the fabric transporting member is further improved, and water resistance is improved.

[0076] 5. Inkjet printing method The inkjet printing method includes a conveying step of attaching a fabric to an adhesive layer made of the aqueous adhesive composition formed on the surface of a fabric conveying member of an inkjet printing device and conveying the fabric; a heating step of heating the adhesive layer; an attaching step of attaching the fabric to the heated adhesive layer; a recording step of applying an ink composition to the fabric attached to the adhesive layer using an inkjet head; a peeling step of peeling the printed fabric from the adhesive layer; and a washing step of washing the adhesive layer from which the fabric has been peeled with a washing liquid containing water.

[0077] 5.1.Heating process The heating process is a process of heating the adhesive layer. This process softens the adhesive layer during the recording process, further improving its adhesive strength. For example, to avoid a decrease in adhesive strength due to brushing, an adhesive layer with improved washability is envisioned. Such adhesive layers generally have low adhesiveness and tend to have weaker fabric fixing power. Here, by providing a heating process, the adhesive layer is temporarily softened and its adhesiveness is improved, allowing it to be attached and transported afterwards. This allows the fabric to be firmly fixed during recording and is less likely to become sticky during washing.

[0078] The temperature of the adhesive layer when the fabric is attached is preferably 30 to 60° C., and more preferably 35 to 50° C. When the temperature of the adhesive layer is within the above range, adhesive strength tends to be further improved.

[0079] 5.2.Transportation process The conveying step is a step of attaching a fabric to the adhesive layer of the aqueous adhesive composition formed on the surface of a fabric conveying member of an inkjet textile printing device and conveying the fabric. The attachment method is not particularly limited, but examples thereof include a method in which the two are pressed together using a conveying roll, as shown in Figure 1.

[0080] 5.3. Recording process The recording process is a process in which textile printing is performed using an inkjet head on the fabric attached to the adhesive layer. During the recording process, the fabric is transported in a state in which it is in close contact with the fabric transport member via the adhesive layer on the surface of the fabric transport member, and during this transport process, ink is ejected from the recording unit 120 and adhered to the fabric. After this, the fabric with the ink adhered thereto may be peeled off from the adhesive layer and collected.

[0081] The temperature of the adhesive layer during peeling is preferably 10 to 30° C., and more preferably 15 to 25° C. When the temperature of the adhesive layer is within the above range, peelability tends to be further improved.

[0082] 5.4. Cleaning process The cleaning step is a step of cleaning the adhesive layer from which the fabric has been peeled off after textile printing. This step makes it possible to remove lint and other debris from the adhesive layer surface that has adhered to the adhesive layer during the printing step.

[0083] The temperature of the adhesive layer during washing is preferably 5 to 25° C., and more preferably 10 to 23° C. When the temperature of the adhesive layer is within the above range, the decrease in adhesiveness during washing tends to be further suppressed.

[0084] Furthermore, the difference in temperature between the adhesive layer when applied and when washed is preferably 10° C. or more, and more preferably 15° C. or more. This tends to further prevent the adhesive strength from decreasing due to washing while maintaining high adhesive strength when applied. [Example]

[0085] The present invention will be described in more detail below using examples and comparative examples, but the present invention is not limited to the following examples.

[0086] 1. Preparation of aqueous adhesive composition 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 82°C. Then, a total of 497 g of monomers weighed to have the composition ratio shown in Figure 2, 118 g of ion-exchanged water, and 13 g of Hitenol NF-08 (polyoxyethylene styrenated phenyl ether ammonium sulfate, nonionic surfactant, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) were added and mixed with stirring. 248 g of a 2% by mass aqueous solution of ammonium persulfate, a polymerization initiator, was added to the homogenized solution at 82°C over 1.5 hours.

[0087] After adding all the ingredients listed above, the mixture was kept warm for 1 hour and then cooled. Ion-exchanged water was added, and aqueous ammonia was added as a pH adjuster. The mixture was then filtered through a 150-mesh nylon filter to remove coarse particles, yielding an aqueous pressure-sensitive adhesive composition (solid content 50.5% by mass) containing a (meth)acrylic resin and having the composition shown in Figure 3. The amount of each monomer used in Figure 2 is shown in mass%.

[0088] 1.1.Monomer The monomers for the structural units of the (meth)acrylic resin shown in Figure 2 are as follows: The values ​​in parentheses indicate the glass transition temperatures of the homopolymers. EMA: Ethyl methacrylate (65°C) BMA: Butyl methacrylate (20°C) BA: Butyl acrylate (-55°C) 2EHA: 2-ethylhexyl acrylate (-70°C)

[0089] 1.2.Measurement method 1.2.1. Loss modulus The aqueous adhesive composition was applied to a glass substrate and dried to give an adhesive layer thickness of 200 μm. The loss modulus of the adhesive layer thus prepared was measured using a viscoelasticity measuring device (MCR302, manufactured by Anton Paar) under the following conditions. Parallel plate diameter: φ8mm Gap range: approx. 0.6~1.0mm Frequency: 1.0Hz Distortion: 0.2% ·Temperature: -20℃~80℃

[0090] 1.2.2. Adhesive strength The aqueous adhesive composition was applied to a glass substrate and dried to a thickness of 200 μm. A 50 mm wide cotton ball was attached to the adhesive layer thus prepared, and the 90-degree peel force was measured as adhesive strength. Specifically, a fabric was attached to the adhesive layer heated to 33°C with 1.0 kgf / 50 mm, and then the adhesive strength when the fabric was peeled from the adhesive layer after cooling to 23°C was defined as adhesive strength A (N / 50 mm). The adhesive strength when the fabric was attached to the adhesive layer at 1.0 kgf / 50 mm at 23°C and then peeled from the adhesive layer at 23°C was defined as adhesive strength B (N / 50 mm).

[0091] Glass transition temperature The glass transition temperature Tg was measured in accordance with JIS K7121 using a differential scanning calorimeter "DSC8000" (manufactured by Perkin Elmer), and the values ​​shown were obtained by measurement.

[0092] 2. Evaluation Method 2.1. Brush durability test The aqueous adhesive composition was applied to a glass substrate and dried to a thickness of 200 μm. A durability test was performed by pressing the adhesive layer thus prepared against a rotating roller-shaped nylon brush wetted with water.

[0093] The nylon brush used was a 6·10 nylon brush with a bristle length of 50 mm and a bristle diameter of 0.5 mm, attached to a stainless steel cylinder with a diameter of 200 mm. This nylon brush was pressed against the adhesive with a force of 1.0 N / cm, rotated at 6 rpm, and maintained in this state at room temperature for 30 days (brush durability test). The adhesive strength was measured 30 days after the nylon brush had been rotated while pressed against the adhesive layer.

[0094] The adhesive strength after the brush durability test was measured as the 180-degree peel force when a 50 mm wide piece of cotton was attached. Specifically, the adhesive strength (N / 50 mm) was measured when a fabric was attached to the adhesive layer heated to 33°C, and then the temperature was lowered to 23°C and the fabric was peeled from the adhesive layer. The adhesive strength (N / 50 mm) was also measured when a fabric was attached to the adhesive layer at 23°C and then peeled from the adhesive layer at 23°C.

[0095] After the brush durability test, a fabric was attached to the adhesive layer at 23°C, and then the adhesive strength (room temperature adhesive strength) when the fabric was peeled off from the adhesive layer at 23°C was evaluated according to the following evaluation criteria. (Evaluation criteria) A:0.4N / 50mm or more C: Less than 0.4N / 50mm

[0096] The rate of change in adhesive strength after the brush durability test was evaluated according to the following evaluation criteria. (Evaluation criteria) A: 0.06N / ℃ 50mm or more B: 0.05N / ℃, 50mm or more, 0.06N / ℃, less than 50mm C: 0.05N / ℃, less than 50mm

[0097] 3. Evaluation Results The composition and evaluation results of the aqueous adhesive composition used in each example are shown in Figure 3. Figure 3 shows that by including a specific (meth)acrylic resin in the aqueous adhesive composition on the surface of the fabric transport member of the inkjet printing device, the adhesive layer formed on the fabric transport member not only has excellent peelability, but also has improved wash resistance, adhesive strength, and dispersion stability. [Explanation of symbols]

[0098] 100...inkjet printing device, 111, 112...recording medium transport rollers, 120...recording unit, 200...transport device, 210...fabric transport member, 221, 222...transport rollers, 230...drive motor, 240...control device, 250...cleaning unit, 260...removal member, 270...heating unit, 300...recording medium.

Claims

1. An aqueous adhesive composition constituting the adhesive layer of the fabric transporting member of an inkjet printing device, the aqueous adhesive composition comprising: a transport mechanism that transports a fabric by attaching the fabric to an adhesive layer formed on the surface of the fabric transporting member; a heating unit that heats the adhesive layer; an attaching unit that attaches the fabric to the heated adhesive layer; a recording unit that applies an ink composition to the fabric attached to the adhesive layer using an inkjet head; a peeling unit that peels the fabric from the adhesive layer after recording; and a cleaning unit that cleans the adhesive layer from which the fabric has been peeled with a cleaning liquid containing water, and a (meth)acrylic resin, When the adhesive strength when a fabric is attached to the adhesive layer heated to 33°C and then cooled to 23°C and then peeled from the adhesive layer is defined as adhesive strength A (N / 50mm), and the adhesive strength when the fabric is attached to the adhesive layer at 23°C and then peeled from the adhesive layer at 23°C is defined as adhesive strength B (N / 50mm), the rate of change in adhesive strength per unit temperature, expressed as (A-B) / (33°C-23°C), is 0.050 N / °C-50mm or more. Aqueous pressure-sensitive adhesive compositions.

2. The adhesive strength B is 0.5 to 2.0 N / 50 mm. The aqueous pressure-sensitive adhesive composition according to claim 1 .

3. The difference between the loss modulus G"23 at 23°C and the loss modulus G"33 at 33°C (G"23 - G"33) is 3.0 x 10 3 ~10 x 10 3 Pa, The aqueous pressure-sensitive adhesive composition according to claim 1 .

4. the (meth)acrylic resin includes a first (meth)acrylic resin having, as a constituent unit, a (meth)acrylic monomer whose homopolymer has a glass transition temperature of 40°C or higher; The aqueous pressure-sensitive adhesive composition according to claim 1 .

5. the (meth)acrylic resin includes a second (meth)acrylic resin having a glass transition temperature Tg2 higher than the glass transition temperature Tg1 of the first (meth)acrylic resin; The aqueous pressure-sensitive adhesive composition according to claim 1 .

6. The content of the first (meth)acrylic resin is 53 to 82 mass% based on the total amount of the first (meth)acrylic resin and the second (meth)acrylic resin. The aqueous pressure-sensitive adhesive composition according to claim 5 .

7. the total content of the compounds selected from the group consisting of rosin compounds, terpene compounds, and hydrocarbon resins is 5.0 mass% or less relative to the total amount of the aqueous pressure-sensitive adhesive composition; The aqueous pressure-sensitive adhesive composition according to claim 1 .

8. the content of the organic solvent is 5.0 mass% or less relative to the total amount of the aqueous pressure-sensitive adhesive composition; The aqueous pressure-sensitive adhesive composition according to claim 1 .

9. The method comprises a step of applying the aqueous pressure-sensitive adhesive composition according to any one of claims 1 to 8 to a surface of a fabric transport member of an inkjet textile printing device to form a pressure-sensitive adhesive layer. Method of providing adhesiveness.

10. a conveying mechanism for conveying a fabric by adhering the fabric to an adhesive layer made of the aqueous pressure-sensitive adhesive composition according to any one of claims 1 to 8, which is formed on a surface of a fabric conveying member; a heating unit that heats the adhesive layer; an attachment unit that attaches the fabric to the heated adhesive layer; a recording unit that applies an ink composition to the fabric attached to the adhesive layer using an inkjet head; a peeling unit that peels the fabric from the adhesive layer after recording; A cleaning unit that cleans the adhesive layer from which the fabric has been peeled with a cleaning solution containing water. Inkjet printing equipment.

11. A pressure-sensitive adhesive layer made of the aqueous pressure-sensitive adhesive composition according to any one of claims 1 to 8 is provided on the surface thereof. Fabric transport member for inkjet printing device.

12. a conveying step of attaching a fabric to an adhesive layer made of the aqueous adhesive composition according to any one of claims 1 to 8, which is formed on a surface of a fabric conveying member of an inkjet textile printing device, and conveying the fabric; a heating step of heating the adhesive layer; an attachment step of attaching the fabric to the heated adhesive layer; a recording step of applying an ink composition to the fabric attached to the adhesive layer using an inkjet head; a peeling step of peeling the printed fabric from the adhesive layer; and a cleaning step of cleaning the adhesive layer from which the fabric has been peeled off with a cleaning liquid containing water.

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