Composition for deinking agent, deinking agent, and method for producing deinked printed fabric

Abstract

This composition for a deinking agent contains a basic compound and a surfactant.

Description

Composition for deinking agent, deinking agent, and method for producing deinked printed fabric

[0001] The present invention relates to a deinking agent composition, a deinking agent, and a method for producing deinked printed fabric.This application claims priority based on Japanese Patent Application No. 2023-195491 filed in Japan on November 16, 2023, Japanese Patent Application No. 2024-071874 filed in Japan on April 25, 2024, and Japanese Patent Application No. 2024-173805 filed in Japan on October 2, 2024, the contents of which are incorporated herein by reference.

[0002] Promotional flags (nobori flags), which are rectangular pieces of fabric tied to a pole, are displayed as promotional tools in storefronts of various businesses, primarily restaurants. Promotional flags are generally used for about two weeks to six months, resulting in a high turnover rate and a large amount of waste. In recent years, environmental considerations have become more important, and there is a demand for the recycling of promotional flags.

[0003] For example, Patent Document 1 discloses a method for decolorizing recycled flags, in which polyester fiber fabric printed with a disperse dye that constitutes the flag is treated with a decolorizing treatment solution containing an alkaline agent, a reducing agent, and a nonionic surfactant. According to this decolorizing method, since a binder resin is used and no pigment or the like is imparted to the polyester fiber fabric, the dye can be easily decolorized from the polyester fiber fabric by the decolorizing treatment, thereby providing a recyclable flag.

[0004] Patent No. 5072496

[0005] However, the conventional deinking composition described in Patent Document 1 has the problem that a large amount of pigment remains after decolorization on flags printed with pigments, making it impossible to use as a raw material for chemical recycling (paragraph 0077 of Patent Document 1). Furthermore, since many flags are printed with pigments, recycling flags printed with pigments contributes to reducing waste.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a deinking agent composition, a deinking agent, and a method for producing deinked printed fabric, which have better deinking properties.

[0007] The present invention has the following aspects. [1] A deinking composition comprising a basic compound and a surfactant. [2] The deinking composition according to [1], wherein the basic compound comprises one or more compounds selected from the group consisting of basic inorganic compounds and basic organic compounds. [3] The deinking composition according to [1] or [2], wherein the HLB value of the surfactant is 1 to 15. [4] The deinking composition according to any one of [1] to [3], wherein the pH of the deinking composition is greater than 7 and equal to or less than 14. [5] The deinking composition according to any one of [1] to [4], which is used for deinking a printed fabric printed with a pigment.

[0008] [6] A deinking agent comprising the deinking agent composition according to any one of [1] to [5].

[0009] [7] A method for producing a deinked printed fabric, comprising a deinking step of obtaining a deinked printed fabric by applying an external force to the printed fabric in the presence of the deinking agent described in [6]. [8] A method for producing a deinked printed fabric according to [7], wherein the treatment temperature in the deinking step is 45 to 100°C. [9] A method for producing a deinked printed fabric according to [7], wherein the treatment time in the deinking step is 1 to 60 minutes.

[10] A method for producing a deinked printed fabric according to [7], wherein in the deinking step, the deinking agent described in [6], a contact body, and the printed fabric are mixed together, and an external force is applied by bringing the contact body into contact with the printed fabric.

[11] A method for producing a deinked printed fabric according to [7], further comprising a washing step of washing the deinked printed fabric obtained in the deinking step.

[0010] According to the present invention, it is possible to provide a deinking agent composition, a deinking agent, and a method for producing deinked printed fabric that have better deinking properties. Specifically, the present invention is excellent in the ability to remove ink (color paste, pigment printing agent) from printed fabric (deinking properties). In addition, it also has the ability to prevent the removed ink from transferring to areas of the deinked printed fabric that were not previously ink-adhered (white areas) (white area contamination).

[0011] (Deinking composition) The deinking composition of this embodiment is a composition used to remove ink from a printed fabric that has been printed with the ink. The deinking composition of this embodiment contains a basic compound, which provides good deinking properties, and is therefore useful for deinking printed fabrics that have been printed with ink that contains a pigment.

[0012] The pH of the deinking composition of this embodiment is preferably greater than 7 and equal to or less than 14, more preferably equal to or greater than 8 and equal to or less than 14, even more preferably equal to or greater than 10 and equal to or less than 14, and particularly preferably equal to or greater than 11 and equal to or greater than 14. If the pH of the deinking composition of this embodiment is within the above range, the deinking properties will be further improved.

[0013] In this specification, pH refers to the value measured when the deinking agent composition at 25°C is measured using a pH meter (trade name: pH meter F-71, manufactured by Horiba, Ltd.).

[0014] The deinking composition of the present embodiment contains a basic compound and a surfactant.

[0015] <Basic Compound> Examples of the basic compound include basic inorganic compounds and basic organic compounds.

[0016] <Basic Inorganic Compounds> Examples of basic inorganic compounds include alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal hydrogen carbonates, and the like. Examples of alkali metal hydroxides include sodium hydroxide and potassium hydroxide. Examples of alkaline earth metal hydroxides include magnesium hydroxide and calcium hydroxide. Examples of alkali metal hydrogen carbonates include sodium hydrogen carbonate and potassium hydrogen carbonate. Examples of alkali metal carbonates include sodium carbonate and potassium carbonate.

[0017] <Basic Organic Compound> Examples of the basic organic compound include amines, such as ammonia, pyridine, arginine, lysine, triethylamine, and triethanolamine.

[0018] Of the above, the basic compound is preferably a basic inorganic compound, more preferably an alkali metal hydroxide, and more preferably sodium hydroxide or potassium hydroxide.

[0019] The basic compound may be used alone or in combination of two or more. The content of the basic compound is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.5% by mass or more, based on the total amount of the deinking composition of this embodiment. The content of the basic compound is preferably 5.0% by mass or less, more preferably 3.0% by mass or less, and even more preferably 1.5% by mass or less, based on the total amount of the deinking composition of this embodiment.

[0020] When the content of the basic compound is equal to or greater than the above-mentioned preferable lower limit, the deinking property is further improved. When the content of the basic compound is equal to or less than the above-mentioned preferable upper limit, the influence on the printed fabric can be further reduced. Furthermore, the risk of the deinking composition as a chemical substance can be reduced, and recycling systems can be more easily adopted.

[0021] For example, the content of the basic compound is preferably 0.01 mass% or more and 5.0 mass% or less, more preferably 0.1 mass% or more and 3.0 mass% or less, and even more preferably 0.5 mass% or more and 1.5 mass% or less, relative to the total amount of the deinking agent composition of this embodiment.

[0022] <Surfactant> The surfactant may be any of anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants.

[0023] The HLB value of the surfactant is preferably 1 or more and 18 or less, more preferably 3 or more and 17 or less, even more preferably 5 or more and 17 or less, and particularly preferably 6 or more and 17 or less.

[0024] When the HLB value of the surfactant is within the above preferred range, the deinking properties are further improved.

[0025] In this specification, "HLB (Hydrophile-Lipophile Balance)" is a value proposed by Griffin that indicates the balance between hydrophilic and lipophilic groups in a surfactant molecule. This HLB value can be determined experimentally by comparing the emulsifying power of various surfactants, but can typically be calculated using the following formula 1. Formula 1: HLB value = 20 x weight % of hydrophilic portion of surfactant / molecular weight of surfactant

[0026] Of the surfactants listed above, nonionic surfactants are preferred.

[0027] <Nonionic surfactants> Preferred nonionic surfactants are polyoxyalkylene alkyl ethers, polyoxyethylene styrylated phenyl ethers, and polyoxyalkylene tribenzyl phenyl ethers. Preferred polyoxyalkylene alkyl ethers include polyoxyethylene polyoxypropylene lauryl ether, polyoxyethylene polyoxypropylene tridecyl ether, polyoxyethylene polyoxypropylene branched decyl ether, and polyoxyethylene lauryl ether. Preferred polyoxyalkylene tribenzyl phenyl ethers include polyoxyethylene tribenzyl phenyl ether.

[0028] The HLB value of the polyoxyalkylene alkyl ether is preferably 1 or more and 15 or less, more preferably 3 or more and 14.5 or less, even more preferably 5 or more and 14 or less, and particularly preferably 6 or more and 10 or less.

[0029] The HLB value of the polyoxyethylene styrylated phenyl ether is preferably 1 or more and 18 or less, more preferably 10 or more and 17 or less, even more preferably 12 or more and 17 or less, and particularly preferably 13 or more and 16 or less.

[0030] Of the above, polyoxyethylene styryl phenyl ether is preferred as the nonionic surfactant.

[0031] The surfactant may be used alone or in combination of two or more. The content of the surfactant is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, relative to the total amount of the deinking composition of this embodiment. The content of the surfactant is preferably 5.0% by mass or less, more preferably 3.0% by mass or less, and even more preferably 1.0% by mass or less, relative to the total amount of the deinking composition of this embodiment.

[0032] If the surfactant content is equal to or greater than the above-mentioned preferable lower limit, the deinking properties are further improved. If the surfactant content is equal to or less than the above-mentioned preferable upper limit, foaming is less likely to occur, making the paper easier to wash with water.

[0033] For example, the content of the surfactant is preferably 0.01 mass% or more and 5.0 mass% or less, more preferably 0.05 mass% or more and 3.0 mass% or less, and even more preferably 0.1 mass% or more and 1.0 mass% or less, relative to the total amount of the deinking agent composition of this embodiment.

[0034] The deinking composition of this embodiment may contain optional components other than the basic compound and surfactant described above. Examples of the optional components include water, a reducing agent, a chelating agent, and a flocculating agent.

[0035] <Water> Examples of water include ion-exchanged water, tap water, distilled water, etc. One type of water may be used alone, or two or more types may be used in combination.

[0036] The water content is preferably 90 to 99.98% by mass, more preferably 93 to 99% by mass, and even more preferably 95 to 99% by mass, relative to the total amount of the deinking agent composition of this embodiment.

[0037] <Reducing Agent> Examples of reducing agents include hydrosulfite, thiourea dioxide, zinc sulfoxylate-formaldehyde, and sodium sulfoxylate-formaldehyde.

[0038] <Chelating Agent> Examples of the chelating agent include ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), diethylenetriaminepentaacetic acid (DTPA), gluconic acid, and hydroxyethylidene diphosphonic acid.

[0039] (Deinking Agent) The deinking agent of the present embodiment may contain a deinking agent composition, or may be the deinking agent composition itself.

[0040] (Method for producing deinked printed fabric) The method for producing deinked printed fabric of this embodiment is a method for producing deinked printed fabric using the deinking agent described above. The method for producing deinked printed fabric of this embodiment includes a deinking step in which the printed fabric is deinked by applying an external force to it in the presence of the deinking agent described above to obtain a deinked printed fabric. The printed ink and / or the printed fabric is swelled by the deinking agent described above. Then, by applying an external force such as hitting, dropping, kneading, twisting, rubbing, pulling, colliding, or applying pressure (e.g., water pressure) to the printed fabric, the ink can be more effectively peeled off from the printed fabric, further improving deinking properties.

[0041] [Deinking Step] The deinking step is a step in which the printed fabric is deinked by applying an external force to the printed fabric in the presence of the deinking agent described above, thereby obtaining a deinked printed fabric.

[0042] The amount of the deinking agent used is preferably 50 to 400 parts by mass, more preferably 75 to 300 parts by mass, per part by mass of the printed fabric.

[0043] The treatment temperature in the deinking step is preferably 45 to 100°C, more preferably 50 to 95°C, even more preferably 60 to 95°C, and particularly preferably 70 to 90°C.

[0044] The treatment time in the deinking step is preferably 1 to 60 minutes, and more preferably 10 to 45 minutes.

[0045] The deinking step preferably involves a rotation process. Specifically, it is preferable to carry out a rotation process at 10 to 1000 rotations / minute, more preferably at 10 to 600 rotations / minute, and even more preferably at 10 to 100 rotations / minute.

[0046] The deinking step is preferably carried out using a stirrer. Examples of the stirrer include a rounder meter, a stirrer, an industrial washing machine, a bleaching / bleaching device, etc. Of these, a rounder meter and a stirrer are preferred as the stirrer.

[0047] A rounder meter is a device that rotates a container containing stainless steel balls, which stir the liquid. A stirrer is a device that uses magnetic force to rotate a magnetic rod called a rotor (stirrer) inside a container to stir the liquid.

[0048] When a rounder meter is used in the deinking process, the diameter of the stainless steel ball is preferably 2 to 10 mm, more preferably 4 to 8 mm, and even more preferably 6 to 8 mm.

[0049] When a rounder meter is used in the deinking step, the number of stainless steel balls is preferably 5 to 45, and more preferably 10 to 30.

[0050] When a stirrer is used in the deinking process, the rotor is preferably tapered. The tapered shape specifications are preferably 10 mm - Φ4, 20 mm - Φ7, 25 mm - Φ8, or 30 mm - Φ8.

[0051] Among the above, the deinking step is preferably a step in which the above-mentioned deinking agent, a contact body, and the printed fabric are mixed together, and an external force is applied by bringing the contact body into contact with the printed fabric. More specifically, it is preferably a step in which a deinked printed fabric is obtained by using a rounder meter, mixing the above-mentioned deinking agent, stainless steel balls, and the printed fabric in a container of the rounder meter, and bringing the stainless steel balls into contact with the printed fabric to apply an external force.

[0052] Printed fabrics are fabrics that have been printed with ink. Examples of such inks include inks containing pigments. More specifically, examples include inks containing a pigment dispersion, a binder resin, a wetting agent, an organic solvent, a pH adjuster, a viscosity adjuster, water, and a crosslinking agent. The ink may also contain a flame retardant. Examples of flame retardants include halogen-based flame retardants, phosphorus-based flame retardants, metal hydroxide-based flame retardants, and antimony-based flame retardants.

[0053] Examples of materials for printed fabrics include polyester, acrylic, polyethylene, polypropylene, nylon, cotton, vinylal, vinylon, ethylene vinyl alcohol fiber, polyvinyl chloride, vinylidene, acrylic, modacrylic, acrylate, aramid, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyarylate fiber, polylactic acid, polyurethane, fluorine fiber, polyimide, polyether ester elastomer, polyphenylene sulfide, alginate, elastodien, elastolefin, melamine fiber, polycarbonamide, trivinyl, polybenzimidazole, chitin fiber, carbon fiber, glass fiber, metal fiber, ceramic fiber, rayon, polynosic, modal, lyocell, cupra, acetate, triacetate, promix, protein fiber, and blends thereof.

[0054] Applications of printed fabrics include advertising banners and curtains, clothing, sportswear, fashion items, bedding, household items such as interior furnishings, car seats, nonwoven fabrics, and the like.

[0055] The method for producing a deinked printed fabric of this embodiment may include an optional step other than the above-mentioned [deinking step]. Such optional step may include a washing step of washing the deinked printed fabric obtained in the [deinking step].

[0056] [Washing step] The washing step is a step in which the deinked printed fabric obtained in the deinking step described above is washed. Specific examples of the washing step include a water-washing step in which the deinked printed fabric obtained in the deinking step described above is washed with water. From the viewpoint of washability, the water-washing step may be carried out while applying an external force. Examples of external forces include the same external forces as those exemplified in the deinking step. The amount of water used depends on the external force applied, but is preferably 5,000 to 50,000 parts by mass, and more preferably 10,000 to 30,000 parts by mass, per part by mass of the printed fabric.

[0057] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to the following examples.

[0058] [Preparation of Test Textile Dyeing Paste] The components shown in Table 1 were mixed to prepare a test textile dyeing paste.

[0059]

[0060] [Preparation of test printed fabric] A polyester pongee (T. Pongee HR white, manufactured by Saiho Chemical Industry Co., Ltd.) was attached to a bracket (made of chloroprene rubber, hardness 60, thickness 5 mm) and printed using a 135 mesh flat screen (2 cm x 4 cm rectangular pattern, 135 mesh, polyester screen, manufactured by Sanko Co., Ltd.) and a test dyeing paste with a squeegee (made of chloroprene rubber, hardness 70, accessory to the MH-5 model). The fabric was then dried at 100°C for 1 minute in a dryer (manufactured by Tsujii Senki Kogyo Co., Ltd., MH-5 model) and then heat-treated at 150°C for 2 minutes in a dryer (manufactured by Tsujii Senki Kogyo Co., Ltd., MH-5 model) to obtain a printed fabric. The resulting printed fabric was cut into a 3 cm x 5 cm rectangle with the 2 cm x 4 cm rectangular pattern in the center to obtain a test printed fabric having a white area and a printed area. The printed side of the test printed fabric is designated as the front.

[0061] [Production of deinking agent (deinking agent composition)] A deinking agent (deinking agent composition) was produced by mixing the basic compounds, surfactants, and water shown in Tables 2 and 3. The materials are as follows. Sodium hydroxide (special grade sodium hydroxide, manufactured by Kishida Chemical Co., Ltd.) Potassium hydroxide (special grade potassium hydroxide, manufactured by Kishida Chemical Co., Ltd.) Polyoxyethylene polyoxypropylene lauryl ether (DKS NL-DASH 404, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., HLB = 8) Polyoxyethylene polyoxypropylene lauryl ether (DKS NL-DASH 403, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., HLB = 6.5) Polyoxyethylene polyoxypropylene lauryl ether (DKS NL-DASH 408, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., HLB = 12) Polyoxyethylene polyoxypropylene tridecyl ether (Noigen TDX-50, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., HLB = 9.0) Polyoxyethylene polyoxypropylene tridecyl ether (Noigen TDX-80D, Dai-ichi Kogyo Seiyaku Co., Ltd., HLB = 13.1) Polyoxyethylene lauryl ether (DKS NL-40, Dai-ichi Kogyo Seiyaku Co., Ltd., HLB = 9.5) Polyoxyethylene polyoxypropylene branched decyl ether (Noigen XL-41, Dai-ichi Kogyo Seiyaku Co., Ltd., HLB = 10.5) Polyoxyethylene styrylated phenyl ether (Noigen EA-87, Dai-ichi Kogyo Seiyaku Co., Ltd., HLB = 10.6) Polyoxyethylene styrylated phenyl ether (Noigen EA-137, Dai-ichi Kogyo Seiyaku Co., Ltd., HLB = 13.0) Polyoxyethylene styrylated phenyl ether (Noigen EA-177, Dai-ichi Kogyo Seiyaku Co., Ltd., HLB = 15.6) Polyoxyethylene tribenzyl phenyl ether (Emulgen B-66, Kao Corporation, HLB = 13.2)

[0062]

[0063]

[0064] [Evaluation of deinking properties] Deinked printed fabrics were produced by carrying out the deinking step and the water rinsing step under the conditions shown in Tables 4 and 5. Five test printed fabrics were used. For the Examples and Comparative Examples other than Example 7, the water rinsing step was carried out by pouring 10,000 mL of tap water, which had been sprayed in a shower after the deinking step, onto the five test printed fabrics. For Example 7, when pouring 10,000 mL of tap water onto the five test printed fabrics after the deinking step, the fabrics were washed by rubbing them together. The "amount of deinking agent used" in Tables 4 and 5 is the amount per part by mass of the test printed fabric.

[0065] The equipment used in the test is as follows: Rounder meter (L-16Z-T, manufactured by Daiei Scientific Instruments Co., Ltd.) Built-in cup capacity: 550 mL

[0066] Stirrer (SYNCHRO-M-STIRRER SYM-6, manufactured by ADVANTEC) A stirrer tip (tapered, 25 mm-Φ8 (length: 25 mm, diameter of central cross section circle: 8 mm), manufactured by AZONE), the deinking agent, and the test printed fabric were placed in a glass bottle (70 mL, M-70, manufactured by Kakuyo Glass Co., Ltd.), and stirred under the conditions in the table.

[0067] The operating condition [revolutions / minute] means the number of revolutions of the container when a rounder meter is used, and means the number of revolutions of the stirrer tip when a stirrer is used.

[0068] <Presence or absence of coloration in the deinking agent> If the answer is "yes," it means that the test dyeing paste has dissolved into the deinking agent or has peeled off and dispersed.

[0069] <Deinking ability> The evaluation criteria for deinking ability are as follows, and evaluation was performed on both the front and back of the test printed fabric. The evaluation criteria conform to "JIS L 0804 2004, Grace Scale for Discoloration and Fading." The evaluation is on a 9-point scale, and the smaller the value, the more deinked it is and the better the deinking ability.

[0070] <<White Ground Staining>> The evaluation criteria for white ground staining are as follows. The evaluation criteria conform to "JIS L 0805 2005, Gray Scale for Staining." There are nine levels of evaluation, and the higher the value, the less white ground staining there is.

[0071]

[0072]

[0073] As shown in Tables 4 and 5, the methods for producing deinked printed fabrics in Examples 1 to 21, which used deinking agent compositions (deinking agents) containing a basic compound and a surfactant, had better deinking properties than the methods for producing deinked printed fabrics in Comparative Examples 1 and 2.

[0074] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Addition, omission, substitution, and other modifications of the configuration are possible within the scope of the spirit of the present invention. The present invention is not limited by the above description, but is limited only by the scope of the appended claims.

Claims

1. A composition for use as a deinking agent, comprising a basic compound and a surfactant.

2. The composition for use as a deinking agent according to claim 1, wherein the basic compound comprises one or more compounds selected from the group consisting of basic inorganic compounds and basic organic compounds.

3. The deinking composition according to claim 1, wherein the HLB value of the surfactant is 1 to 15.

4. The deinking composition according to claim 1, wherein the pH of the deinking composition is greater than 7 and less than 14.

5. The deinking composition according to claim 1, which is used for deinking a printed cloth printed with a pigment.

6. A deinking agent comprising the deinking composition according to any one of claims 1 to 5.

7. A method for producing deinked printed fabric, comprising a deinking step of obtaining a deinked printed fabric by applying an external force to the printed fabric in the presence of the deinking agent according to claim 6.

8. The method for producing deinked printed fabric according to claim 7, wherein the treatment temperature in the deinking step is 45 to 100°C.

9. The method for producing deinked printed fabric according to claim 7, wherein the treatment time in the deinking step is 1 to 60 minutes.

10. A method for producing a deinked printed cloth as described in claim 7, in which, in the deinking process, the deinking agent described in claim 6, a contact body, and the printed cloth are mixed together, and an external force is applied by contacting the contact body with the printed cloth.

11. A method for producing a deinked printed fabric according to claim 7, further comprising a washing step of washing the deinked printed fabric obtained in the deinking step.

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