Cleaning method
Patent Information
- Application Number
- JP2023026555
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-02-22
- Publication Date
- 2025-12-24
Abstract
Description
[Technical field]
[0001] The present invention relates to a washing method. [Background technology]
[0002] In the washing of textile products, textile products are cleaned through processes such as washing, rinsing, and spin-drying. In the washing, a detergent containing a surfactant as a main washing base and builders such as an alkaline agent and a chelating agent is used. As the surfactant, anionic surfactants, nonionic surfactants, etc. are mainly used. In the washing, improvements from various perspectives such as improving the washing power, reducing the workload, and reducing the wastewater load are being attempted.
[0003] Patent Document 1 discloses a washing method including step 1 of contacting the articles to be washed with a predetermined washing liquid containing a surfactant and an alkaline agent, and step 2 of washing the articles after step 1 by applying physical force with the predetermined washing liquid containing a surfactant and an alkaline agent.
[0004] Patent Document 2 discloses a method for washing clothes using a continuous vertical inner-body rotary washer which has at least two independent washing tanks, in which clothes are washed in one washing tank, the washing liquid in that washing tank is then discharged, and the clothes are moved to the next washing tank for re-washing, in which (A) a liquid detergent mainly composed of a surfactant and (B) a liquid cleaning aid mainly composed of a chelating agent and / or an alkaline agent are used, and the liquid cleaning aid (B) is added to a washing tank prior to the washing tank to which the liquid detergent (A) is added.
[0005] Patent Document 3 discloses a cleaning method in which an object to be cleaned is cleaned with an alkaline buffer solution. [Prior art documents] [Patent documents]
[0006] [Patent Document 1] JP 2013-253352 A [Patent Document 2] Japanese Patent Application Publication No. 7-119033 [Patent Document 3] Japanese Patent Application Publication No. 2001-252630 Summary of the Invention [Problem to be solved by the invention]
[0007] The present invention provides a washing method capable of reducing odors caused by stains on textile products. [Means for solving the problem]
[0008] The present invention relates to a method for washing a textile product, comprising the following steps 1 and 2: Step 1: A step of pretreating a soiled textile product by contacting the textile product with a treatment liquid, the treatment liquid containing an alkaline agent, water, and optionally a surfactant, having a pH of 10 or more, and containing the alkaline agent in an amount of 0.05% by mass or more and 10% by mass or less relative to the mass of the textile product. Step 2: After step 1, a step of increasing the mass of the surfactant contained in the treatment liquid without substantially increasing the mass of the alkaline agent contained in the treatment liquid, and washing the textile product with the treatment liquid. Effect of the Invention
[0009] According to the present invention, there is provided a washing method capable of reducing odors caused by stains on textile products after washing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] In the washing method of the present invention, first, in step 1, a soiled textile product is pretreated by contacting it with a treatment liquid containing an alkaline agent in an amount of 0.05% by mass to 10% by mass relative to the mass of the soiled textile product, water, and optionally a surfactant, and having a pH of 10 or higher. Then, in step 2, a washing treatment is performed in which the mass of the surfactant contained in the treatment liquid is increased without substantially increasing the mass of the alkaline agent contained in the treatment liquid, and the textile product is washed with the treatment liquid with the increased mass of the surfactant.
[0011] In the laundry, it is desirable for the washing power to be excellent for the soiled textile products to be washed, and so the washing conditions (washing process, detergent composition, etc.) are often considered from this perspective. However, it has been found that even textile products that appear to have had the same dirt removed can have different odor intensities due to the dirt. The present invention has found that odors caused by dirt can be reduced by performing the pretreatment in step 1 and the washing treatment in step 2 under predetermined conditions. Compared to washing methods other than the present invention, the washing method of the present invention can reduce odors caused by dirt in textile products after washing even if the apparent cleaning power is equivalent, and therefore it is presumed that the effect is expressed from a different aspect than the removal of apparent dirt.
[0012] <Process 1> In the washing method of the present invention, a soiled textile product is prepared, and first, in step 1, the textile product is pretreated by contacting the textile product with a treatment liquid having a pH of 10 or more, the treatment liquid containing an alkaline agent in an amount of 0.05% by mass to 10% by mass relative to the mass of the soiled textile product, water, and optionally a surfactant.
[0013] The treatment liquid in step 1 contains an alkaline agent from the viewpoint of odor reducing effect. An alkaline agent is an agent that exhibits alkaline properties when dissolved in water. From the viewpoint of odor reducing effect, the alkaline agent may be one or more compounds selected from alkali metal hydroxides, alkali metal silicates, alkali metal carbonates, organic amine compounds, and alkali metal hydrogen carbonates. From the viewpoint of odor reducing effect, examples of the alkali metal hydroxide include sodium hydroxide and potassium hydroxide. From the viewpoint of odor reducing effect, examples of the alkali metal silicate include sodium silicate and crystalline alkali metal silicate. From the viewpoint of odor reducing effect, examples of the alkali metal carbonate include sodium carbonate and potassium carbonate. From the viewpoint of odor reducing effect, examples of the organic amine compound include monoethanolamine, diethanolamine, and triethanolamine. Examples of the alkali metal hydrogen carbonate include sodium hydrogen carbonate and potassium hydrogen carbonate from the viewpoint of odor reducing effect. Furthermore, as the alkaline agent, a double salt of an alkali metal carbonate and an alkali metal hydrogen carbonate, such as sodium sesquicarbonate, may be used. Any one of these compounds may be used alone, or a plurality of compounds may be used in combination. From the viewpoint of odor reduction effect, the alkaline agent is preferably one or more compounds selected from alkali metal carbonates and alkali metal hydrogen carbonates, more preferably alkali metal carbonates and alkali metal hydrogen carbonates, and further preferably potassium carbonate and potassium hydrogen carbonate.
[0014] From the viewpoint of odor reduction effect, it is preferable to use the alkaline agent in combination of a strong basic compound and a weak basic compound. For example, it is preferable to combine an alkali metal carbonate, more preferably potassium carbonate, as the strong basic compound, and an alkali metal hydrogen carbonate, more preferably potassium hydrogen carbonate, as the weak basic compound. For example, when preparing a treatment liquid by diluting a treatment liquid composition containing an alkaline agent with water as described below, the above combination can be used as the alkaline agent to impart pH buffering ability to the treatment liquid composition against dilution, which also contributes to maintaining the odor reduction effect.
[0015] From the viewpoint of odor reduction effect, the proportion of alkali metal hydrogen carbonate in the alkaline agent is preferably 5 mass% or more, more preferably 10 mass% or more, even more preferably 15 mass% or more, and preferably 80 mass% or less, more preferably 75 mass% or less, and even more preferably 70 mass% or less. The alkaline agent is preferably one or more compounds selected from alkali metal hydroxides, alkali metal silicates, and alkali metal carbonates, and one or more compounds selected from alkali metal hydrogen carbonates. In this case, the proportion of the alkali metal hydrogen carbonate in the alkaline agent is preferably within the above range.
[0016] From the viewpoint of odor reduction effect, the treatment liquid in step 1 contains an alkaline agent in a proportion of 0.05% by mass or more, preferably 0.1% by mass or more, more preferably 0.15% by mass or more, even more preferably 0.2% by mass or more, and even more preferably 0.3% by mass or more, based on the mass of the soiled textile product; and from the viewpoint of suppressing eutrophication of the wastewater discharged by washing, it contains an alkaline agent in a proportion of 10% by mass or less, preferably 9% by mass or less, more preferably 8% by mass or less, even more preferably 7% by mass or less, even more preferably 6% by mass or less, even more preferably 3% by mass or less, even more preferably 2% by mass or less, even more preferably 1% by mass or less, even more preferably 0.9% by mass or less, even more preferably 0.8% by mass or less, and even more preferably 0.7% by mass or less.
[0017] The treatment liquid in step 1 has a pH of 10 or more, and from the viewpoint of odor reduction effect, preferably 10.1 or more, more preferably 10.2 or more, and preferably 12 or less, more preferably 11 or less. The pH is measured according to the pH measurement method described below. The pH of the treatment liquid is the pH at the temperature at which step 1 is carried out, but may be the pH at 20°C. [pH measurement method] A pH measurement composite electrode (HORIBA 9615S Measurement Method Model JF15) is connected to a pH meter (HORIBA pH / Ion Meter D-74) and the power is turned on. A saturated potassium chloride aqueous solution (3.33 mol / L) is used as the pH electrode internal solution. Next, a 100 mL beaker is filled with a pH 4.01 standard solution (phthalate standard solution), a pH 6.86 standard solution (neutral phosphate standard solution), and a pH 9.18 standard solution (borate standard solution), and the beaker is immersed in a thermostatic bath at the temperature for performing step 1 or at 20°C for 30 minutes. The pH measurement electrode is immersed in the thermostatically adjusted standard solution for 3 minutes, and the calibration operation is performed in the order of pH 6.86 → pH 9.18 → pH 4.01. The sample to be measured is adjusted to the temperature for performing step 1 or to 20°C, and the electrode of the pH meter is immersed in the sample and the pH is measured after 2 minutes.
[0018] The treatment liquid in step 1 contains water. Water is the remainder of the treatment liquid. Examples of water include ion-exchanged water, industrial water, city water, well water, and river water.
[0019] From the viewpoint of odor reduction effect, the hardness of the water used in the treatment liquid in step 1 is preferably 0° DH or more and 20° DH or less, and more preferably 1.5° DH or more and 15° DH or less. The hardness is measured according to the hardness measurement method described below. <Method of measuring water hardness in Germany> 〔reagent〕 0.01 mol / L EDTA·2Na solution: 0.01 mol / L aqueous solution of disodium ethylenediaminetetraacetate (titration solution, 0.01M EDTA-Na2, manufactured by Sigma-Aldrich) ·Universal BT indicator (product name: Universal BT, manufactured by Dojindo Laboratories Co., Ltd.) Ammonia buffer solution for hardness measurement (67.5 g of ammonium chloride dissolved in 570 ml of 28 w / v% ammonia water, and the total volume made up to 1000 ml with ion-exchanged water) [Method of measuring hardness] First, 20 mL of sample water was collected in a conical beaker using a whole pipette, and 2 mL of ammonia buffer solution for hardness measurement was added. Furthermore, 0.5 mL of Universal BT indicator was added, and it was confirmed that the solution after addition was reddish purple. While shaking the conical beaker well, 0.01 mol / L EDTA·2Na solution was dropped from the burette, and the end point of the titration was when the sample water turned blue. The total hardness in the sample was calculated from the titration volume T (mL) of the EDTA·2Na solution using the following formula. Hardness (°DH)=(T×0.01×F×56.0774×100) / A T:0.01mol / L Titration amount of EDTA・2Na solution (mL) A: Sample volume (20 mL, volume of sample water) F: Factor of 0.01mol / L EDTA·2Na solution
[0020] The treatment liquid in step 1 optionally contains a surfactant. The surfactant may be one or more selected from cationic surfactants, nonionic surfactants, anionic surfactants, and amphoteric surfactants.
[0021] When the treatment liquid in step 1 contains a surfactant, the amount of the surfactant is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and preferably 1% by mass or less, more preferably 0.8% by mass or less, and even more preferably 0.6% by mass or less, based on the mass of the soiled textile product. The surfactant content is based on the active component.
[0022] The treatment liquid in step 1 may contain other optional components such as water softeners, dispersants, foam regulators, solvents, stabilizers, enzymes, and fragrances.
[0023] The treatment liquid in step 1 may be a mixture of an alkaline agent, water, and optionally a surfactant. The treatment liquid in step 1 is preferably a mixture of a treatment liquid composition containing an alkaline agent (hereinafter also referred to as a treatment liquid composition) and water. The treatment liquid composition preferably contains an alkaline agent and water. The treatment liquid composition may contain, for example, 5% by mass or more and 50% by mass or less of an alkaline agent.
[0024] From the viewpoint of odor reducing effect, it is preferable that the treatment liquid composition has a buffering capacity. For example, it is preferable that a composition for a treatment liquid, which further contains 5% by mass or more and 50% by mass or less of an alkaline agent, has a pH (20°C) of a diluted solution diluted 1000 times with water within a range of ±1 of the pH (20°C) of the composition for a treatment liquid used for dilution. Furthermore, for example, a composition for a treatment liquid, which further contains 5% by mass or more and 50% by mass or less of an alkaline agent, preferably has a pH (20°C) when diluted with water that is within a range of ±1 of the pH (20°C) of the composition for a treatment liquid used for dilution, when the content of the alkaline agent in the diluted solution is any one of 100 ppm or more and 2000 ppm. As a method for imparting buffering ability to a composition for a processing liquid, for example, as described above, there is a method in which a weakly basic salt such as an alkali metal hydrogen carbonate is used as an alkaline agent in combination with another alkaline agent.
[0025] The water contained in the composition for a treatment liquid and the water to be mixed with the composition for a treatment liquid each preferably have the above-mentioned hardness.
[0026] In step 1, the contact time between the treatment liquid and the textile product may be, for example, 30 seconds or more, 1 minute or more, and 30 minutes or less, 20 minutes or less, from the viewpoint of odor reduction effect.
[0027] In step 1, the temperature of the treatment liquid may be, for example, from the viewpoint of odor reduction effect, 0°C or more, and further 5°C or more, and 60°C or less, further preferably 50°C or less, more preferably 40°C or less, and even further preferably 30°C or less.
[0028] In step 1, from the viewpoint of odor reduction effect, it is preferable to contact the treatment liquid with the textile product in a state where an external force is applied, for example, under stirring, in at least a part of step 1. When the treatment liquid and the textile product are contacted in a state where an external force is applied, for example, under stirring, in at least a part of step 1, it is preferable that the ratio of the alkaline agent to the mass of the textile product in the treatment liquid and the pH are each within the above-mentioned ranges at least at the time when the application of the external force, for example, stirring, is started.
[0029] The liquor ratio in step 1 may be, for example, from the viewpoint of odor reduction effect, 3 or more, further 4 or more, and 40 or less, further 35 or less. Here, the liquor ratio is the ratio of the amount of treatment liquid (L) to the mass of the textile product (kg), that is, amount of treatment liquid (L) / mass of textile product (kg).
[0030] <Process 2> In the washing method of the present invention, after step 1, a cleaning treatment is carried out as step 2 in which the mass of the surfactant contained in the treatment liquid is increased without substantially increasing the mass of the alkaline agent contained in the treatment liquid, i.e., the treatment liquid used in step 1, and the textile product is washed with the treatment liquid.
[0031] Here, "the mass of the alkaline agent contained in the treatment liquid is not substantially increased" means that the mass of the alkaline agent in the treatment liquid used in step 2 is approximately the same as the mass of the alkaline agent in the treatment liquid used in step 1, and that the amount of the alkaline agent may vary slightly due to the influence of components that are inevitably mixed into the treatment liquid when performing step 2. For example, in the present invention, the mass of the alkaline agent in the treatment liquid used in step 2 may be within a range of 5%, further within 4%, and further within 3% of the mass of the alkaline agent in the treatment liquid used in step 1, and when it is within this range, it may be said that the mass of the alkaline agent is not substantially increased. For example, in the present invention, step 2 may be a step of increasing the mass of the surfactant contained in the treatment liquid after step 1 without substantially increasing the mass of the alkaline agent contained in the treatment liquid, and washing the textile product with the treatment liquid, wherein the mass of the alkaline agent in the treatment liquid used in step 2 is within 5%, further within 4%, further within 3% of the mass of the alkaline agent in the treatment liquid used in step 1. Furthermore, for example, in the present invention, step 2 may be a step of increasing the mass of the surfactant contained in the treatment liquid after step 1 without substantially increasing the mass of the alkaline agent contained in the treatment liquid, and washing the textile product with the treatment liquid, wherein the ratio (mass %) of the alkaline agent in the treatment liquid used in step 2 to the mass of the textile product is within 5%, further within 4%, further within 3% of the ratio (mass %) of the alkaline agent in the treatment liquid used in step 1 to the mass of the textile product.
[0032] The mass of the surfactant in the processing solution used in step 2 can be increased by adding a composition (agent) containing a surfactant to the processing solution, such as adding a cleaning agent containing a surfactant, adding a bleaching agent containing a surfactant, or adding an antibacterial agent containing a surfactant, and is preferably increased by adding a cleaning agent containing a surfactant to the processing solution. The cleaning agent may be, for example, a liquid containing 10% by mass or more, further 15% by mass or more, and 80% by mass or less, further 70% by mass or less of a surfactant, and water, from the viewpoint of odor reduction effect. The cleaning agent preferably contains a small amount of alkaline agent. For example, from the viewpoint of odor reduction effect, the cleaning agent may contain 5% by mass or less of alkaline agent, and further 3% by mass or less. The pH of the cleaning agent at 20° C. may be, for example, 3 or more, further 4 or more, and 11 or less, further 10 or less, from the viewpoint of odor reducing effect. The detergent may be in any form. For example, the detergent may be in the form of a liquid, solid, or a combination thereof, such as a powder, tablet, film, water-soluble unit dose detergent (film containing liquid, gel, or powder), beads, cartridge, etc.
[0033] When the treatment liquid used in step 1 contains a surfactant, from the viewpoint of odor reduction effect, the amount of surfactant in the treatment liquid used in step 2 may be at least 1 time, further at least 1.5 times, and further at least 2 times the amount of surfactant in the treatment liquid used in step 1.
[0034] From the viewpoint of odor reduction effect, the surfactant in the treatment liquid used in step 2 may be one or more selected from anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants. From the viewpoint of odor reduction effect, the surfactant is preferably one or more selected from anionic surfactants and nonionic surfactants.
[0035] The treatment liquid used in step 2 contains a surfactant in an amount of preferably 0.05% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.15% by mass or more, and still more preferably 0.18% by mass or more, based on the mass of the textile product, from the viewpoint of odor reduction effect, and preferably 1% by mass or less, more preferably 0.8% by mass or less, and even more preferably 0.6% by mass or less, from the viewpoint of suppressing eutrophication of the wastewater discharged by washing.
[0036] The treatment liquid in step 2 contains an alkaline agent, a surfactant, and water. The alkaline agent is derived from the treatment liquid used in step 1. The water is derived from the treatment liquid used in step 1 and is added to the treatment liquid in step 2. When water is added to the treatment liquid in step 2, the hardness of the water (measured as described above) is preferably 0° DH or more, more preferably 1.5° DH or more, and preferably 20° DH or less, more preferably 15° DH or less, from the viewpoint of odor reduction effect. The treatment liquid for step 2 may contain other optional components such as water softeners, chelating agents, dispersants, foam regulators, solvents, stabilizers, fluorescent dyes, bluing agents, enzymes, bleaching agents, bleach activators, fragrances, and fabric softeners.
[0037] In the present invention, step 2 is provided after step 1, but a preparation step for carrying out step 2 may be included before the completion of step 1. For example, preparation for an operation for increasing the mass of the surfactant in the treatment liquid may be carried out before the completion of step 1, such as starting preparation for adding a cleaning agent before the completion of step 1.
[0038] In step 2, the contact time between the treatment liquid and the textile product may be, for example, 1 minute or more, further 3 minutes or more, and 60 minutes or less, or 50 minutes or less, from the viewpoint of odor reduction effect.
[0039] In step 2, the temperature of the treatment liquid may be, for example, 0° C. or higher, further 5° C. or higher, and 60° C. or lower, further 50° C. or lower, from the viewpoint of odor reduction effect.
[0040] In step 2, it is preferable to wash the textile product with the treatment liquid in a state where an external force is applied, for example, under stirring, in at least a part of step 2. When washing the textile product with the treatment liquid in a state where an external force is applied, for example, under stirring, in at least a part of step 2, it is preferable that the mass of the surfactant contained in the treatment liquid is increased at least at the time when the application of the external force, for example, stirring, starts, compared to the mass of the surfactant contained in the treatment liquid in step 1.
[0041] The liquor ratio in step 2 may be, for example, 3 or more, further 4 or more, and 40 or less, further 35 or less, from the viewpoint of odor reduction effect.
[0042] In the present invention, it is preferable that steps 1 and 2 are carried out in the same treatment tank. By using the same treatment tank, workability is improved and the amount of water used and time can be reduced. In addition, the odor reduction effect can be further enhanced. For example, the treatment liquid for step 2 can be easily obtained by adding a surfactant to the treatment liquid for step 1 in the same treatment tank. In the present invention, steps 1 and 2 can be carried out continuously. In the present invention, one or both of steps 1 and 2 can be carried out multiple times. When one or both of steps 1 and 2 are carried out multiple times, it is preferable that there is at least one combination of steps 1 and 2 that are carried out continuously.
[0043] For example, the washing method of the present invention includes the steps of: Step 1 is a step of pretreating a soiled textile product by contacting the textile product with a treatment liquid contained in a treatment tank in the treatment tank, the treatment liquid containing an alkaline agent, water and optionally a surfactant, having a pH of 10 or more, and containing an alkaline agent in an amount of 0.05% by mass or more and 10% by mass or less relative to the mass of the textile product, Step 2 is a step of increasing the mass of the surfactant contained in the treatment liquid in the treatment tank after step 1 without substantially increasing the concentration of the alkaline agent in the treatment liquid, and washing the textile product with the treatment liquid. It may be a washing method.
[0044] The washing method of the present invention may be a method for washing textile products including the following steps 1a and 2a. Step 1a: A step of contacting a soiled textile product with a treatment liquid to perform pretreatment, the treatment liquid being obtained by mixing a treatment liquid composition containing an alkaline agent with water, the treatment liquid containing an alkaline agent, water and optionally a surfactant, having a pH of 10 or more, and containing 0.05% by mass or more and 10% by mass or less of the alkaline agent relative to the mass of the textile product; Step 2a: After step 1a, a cleaning agent containing a surfactant is added to the treatment liquid to increase the mass of the surfactant contained in the treatment liquid without substantially increasing the mass of the alkaline agent contained in the treatment liquid, and the textile product is washed with the treatment liquid.
[0045] The washing method of the present invention further comprises the steps of: Prepare a textile product containing soil; mixing a composition for a treatment liquid containing an alkaline agent with water and optionally a surfactant to prepare a treatment liquid containing an alkaline agent in an amount of 0.05% by mass to 10% by mass relative to the mass of the textile product, water and optionally a surfactant, and having a pH of 10 or more; In step 1, a soiled textile product is pretreated by contacting the textile product with the treatment liquid in a treatment tank; as step 2, after step 1, a cleaning treatment is carried out in which a cleaning liquid composition containing a surfactant is added to the treatment liquid in the treatment tank to increase the mass of the surfactant contained in the treatment liquid without substantially increasing the mass of the alkaline agent in the treatment liquid, and the textile product is washed with the treatment liquid; The washing method may include: The treatment liquid may be prepared in the treatment tank, or may be prepared separately and then charged into the treatment tank. Alternatively, the treatment liquid may be prepared by charging the treatment liquid composition and water into the treatment tank after the textile product has been charged into the treatment tank.
[0046] Another embodiment of the present invention is, for example, a method for washing a textile product, comprising the following steps 1 and 2b. Step 1: A step of pretreating a soiled textile product by contacting the textile product with a treatment liquid, the treatment liquid containing an alkaline agent, water, and optionally a surfactant, having a pH of 10 or more, and containing the alkaline agent in a proportion of 0.05% by mass or more and 10% by mass or less relative to the mass of the textile product (hereinafter referred to as proportion (1)). Step 2b: After step 1, a step of setting the ratio of the mass of the alkaline agent contained in the treatment liquid to the mass of the textile product within 5%, further within 4%, further within 3% of the ratio (1), and increasing the mass of the surfactant contained in the treatment liquid, and washing the textile product with the treatment liquid.
[0047] In the washing method of the present invention, the above-mentioned predetermined step 1 and predetermined step 2 are carried out, but it may also include steps of processing other than these. For example, it may include steps of processing such as rinsing, spin-drying, and drying that are carried out in a normal washing method. EXAMPLES
[0048] The ingredients, fabrics, washing machines, etc. used in the examples and comparative examples are shown below. <Treatment liquid composition> The following processing liquid compositions (1) to (8) were prepared. The compositions of the processing liquid compositions are shown in the table. Treatment liquid composition (1): A composition prepared by mixing 5 g of sodium metasilicate, 7.7 g of potassium bicarbonate, and 200 g of ion-exchanged water (pH 11.0 at 20°C) Treatment liquid composition (2): A composition prepared by mixing 10 g of sodium metasilicate, 14.12 g of potassium bicarbonate, and 1,000 g of ion-exchanged water (pH 11.0 at 20°C) Treatment liquid composition (3): A composition prepared by mixing 10 g of potassium carbonate, 2.36 g of potassium bicarbonate, and 20 g of ion-exchanged water (pH 10.8 at 20°C) Treatment liquid composition (4): A composition prepared by mixing 12.5 g of potassium carbonate, 2.94 g of potassium bicarbonate, and 25 g of ion-exchanged water (pH 10.8 at 20°C) Treatment liquid composition (5): A composition prepared by mixing 15.0 g of potassium carbonate, 3.53 g of potassium bicarbonate, and 30 g of ion-exchanged water (pH 10.8 at 20°C) Treatment liquid composition (6): A composition prepared by mixing 17.5 g of potassium carbonate, 4.12 g of potassium bicarbonate, and 35 g of ion-exchanged water (pH 10.8 at 20°C) Treatment liquid composition (7): A composition prepared by mixing 20 g of potassium carbonate, 4.71 g of potassium bicarbonate, and 40 g of ion-exchanged water (pH 10.8 at 20°C) Treatment liquid composition (8): A composition prepared by mixing 67.5 g of soda ash and 450 g of ion-exchanged water (pH 11.5 at 20°C)
[0049] Cationic surfactant: Kao Corporation, Kotamin-40ES (active ingredient 25%) Liquid cleaning agent: Kao Corporation, Attack Zero Powdered cleaning agent: Kao Corporation, Powdered Attack Water: Tap water (Wakayama City water)
[0050] - Contaminated cloth: A cloth measuring 7cm x 7cm with model sebum stains applied <Preparation of model cloth artificially soiled with sebum> A model artificial sebum-contaminated cloth was prepared by applying a model artificial sebum-contaminated liquid having the following composition to a cloth. The model artificial sebum-contaminated liquid was applied to the cloth by printing the artificially contaminated liquid on the cloth using a gravure roll coater. The process of applying the model artificial sebum-contaminated liquid to the cloth to prepare the model artificial sebum-contaminated liquid was carried out using a gravure roll with a cell capacity of 58 cm. 3 / m 2 The coating speed was 1.0 m / min, the drying temperature was 100°C, and the drying time was 1 min. Cotton 2003 (manufactured by Tanigashira Shoten) was used for the cloth. *Composition of model artificial sebum contamination liquid: 0.4% by mass of lauric acid, 3.1% by mass of myristic acid, 2.3% by mass of pentadecanoic acid, 6.2% by mass of palmitic acid, 0.4% by mass of heptadecanoic acid, 1.6% by mass of stearic acid, 7.8% by mass of oleic acid, 13.0% by mass of triolein, 2.2% by mass of n-hexadecyl palmitate, 6.5% by mass of squalene, 1.9% by mass of egg white lecithin liquid crystal, 8.1% by mass of Kanuma red soil, 0.01% by mass of carbon black, remaining water (total 100% by mass) Mass adjustment cloth: Cotton (100% cotton) / Synthetic fiber (100% polyester) = 7 / 3 (mass ratio) Washing machine: Drum type washing machine, Panasonic Corporation, model number NA-VX900BL
[0051] <Example 1> The following steps 1 and 2 were carried out, and the odor was evaluated. The table below shows an overview of steps 1 and 2 in the examples, and the results of the odor evaluation.
[0052] <Process 1> Five soiled cloths and a cloth for adjusting the weight were placed in the washing tub of a drum-type washing machine so that the total weight was 4 kg. The entire amount of the treatment liquid composition (1) was placed therein, and tap water was added in the automatic cycle of the washing machine, and the soiled cloths were pretreated for 9 minutes. The pH of the treatment liquid for pretreatment was 10.5, and the pH of the treatment liquid when diluted was within a range of ±1 compared to the pH of the treatment liquid composition before dilution, so it was confirmed that the treatment liquid composition (1) has a buffering ability.
[0053] <Process 2> After the pretreatment in step 1 was completed, 9 g of liquid detergent was added to the treatment liquid in the washing tub without draining the water, and the treatment liquid in step 2 was prepared and the washing treatment was carried out for 9 minutes. The washing treatment was carried out on the automatic course of the washing machine. The pH of the treatment liquid in the washing treatment was 10.4. After the washing process, the cloth was rinsed twice and then dehydrated for 4 minutes. After dehydration, the cloth was left to air dry at room temperature. The odor of the soiled cloth after drying was judged by three evaluators. The judging criteria were as follows: no odor derived from dirt (same odor as the uncontaminated cloth used to prepare the soiled cloth) was given the best score of 0, whereas an extremely strong odor derived from dirt was given the worst score of 5, with scores given in increments of 0.1. The odor was evaluated using the average score of the three evaluators. The results are shown in the table. The closer the score is to 0, the better the effect of reducing odor derived from dirt.
[0054] <Example 2> In the same manner as in Example 1, except that the composition for treatment liquid (2) was used instead of the composition for treatment liquid (1), a stained cloth was washed, and the odor of the stained cloth after washing was evaluated. The results are shown in the table. It was confirmed that the composition for treatment liquid (2) also had a buffering ability.
[0055] <Example 3> In the same manner as in Example 1, except that the composition for processing liquid (3) and 6 g of a cationic surfactant were used instead of the composition for processing liquid (1), a stained cloth was washed, and the odor of the stained cloth after washing was evaluated. The results are shown in the table. It was confirmed that the composition for processing liquid (3) also had a buffering ability.
[0056] <Example 4> In the same manner as in Example 1, except that the composition for processing liquid (4) and 6 g of a cationic surfactant were used instead of the composition for processing liquid (1), a stained cloth was washed, and the odor of the stained cloth after washing was evaluated. The results are shown in the table. It was confirmed that the composition for processing liquid (4) also had a buffering ability.
[0057] <Example 5> In the same manner as in Example 1, except that the composition for processing liquid (5) and 6 g of a cationic surfactant were used instead of the composition for processing liquid (1), a stained cloth was washed, and the odor of the stained cloth after washing was evaluated. The results are shown in the table. It was confirmed that the composition for processing liquid (5) also had a buffering ability.
[0058] <Example 6> In the same manner as in Example 1, except that the composition for processing liquid (6) and 6 g of a cationic surfactant were used instead of the composition for processing liquid (1), a stained cloth was washed, and the odor of the stained cloth after washing was evaluated. The results are shown in the table. It was confirmed that the composition for processing liquid (6) also had a buffering ability.
[0059] <Example 7> In the same manner as in Example 1, except that the composition for processing liquid (7) and 6 g of a cationic surfactant were used instead of the composition for processing liquid (1), a stained cloth was washed, and the odor of the stained cloth after washing was evaluated. The results are shown in the table. It was confirmed that the composition for processing liquid (7) also had a buffering ability.
[0060] <Example 8> In the same manner as in Example 1, except that the composition for treatment liquid (8) was used instead of the composition for treatment liquid (1), a stained cloth was washed, and the odor of the stained cloth after washing was evaluated. The results are shown in the table. The composition for treatment liquid (8) had poor buffering ability.
[0061] <Comparative Example 1> Five soiled cloths and a cloth for adjusting the mass were placed in the washing tub of a drum washing machine so that the total weight was 4 kg. 9 g of liquid detergent was placed therein, and the treatment liquid for step 2 was prepared and the washing process was carried out for 9 minutes. After the washing process was completed, rinsing, spin-drying and drying were carried out in the same manner as in Example 1, and the odor of the soiled cloth after washing was evaluated. In Comparative Example 1, the pretreatment of step 1 of the present invention was not carried out and one washing process was carried out with the liquid detergent, and the washing process was carried out in the automatic course of the washing machine. The results are shown in the table.
[0062] <Comparative Example 2> Five soiled cloths and a cloth for adjusting the mass were put into the washing tub of a drum washing machine so that the total weight was 4 kg. 9 g of liquid detergent was put therein, a treatment liquid for step 2 was prepared, and a first washing process was performed for 9 minutes. Thereafter, the treatment liquid was drained, and 9 g of liquid detergent was put into the washing tub again, a treatment liquid for step 2 was prepared, and a second washing process was performed for 9 minutes. After the second washing process was completed, rinsing, spin-drying, and drying were performed in the same manner as in Example 1, and the odor of the soiled cloth after washing was evaluated. In Comparative Example 2, washing was performed twice with a liquid detergent without performing the pretreatment of step 1 of the present invention, and the washing machine was used in the second wash course. The results are shown in the table.
[0063] <Comparative Example 3> The stained cloth was washed in the same manner as in Comparative Example 1, except that 28 g of the powder detergent was used instead of the liquid detergent, and the odor of the stained cloth after washing was evaluated. The results are shown in the table.
[0064] <Comparative Example 4> The stained cloth was washed in the same manner as in Comparative Example 2, except that 28 g of powder detergent was used instead of the liquid detergent in the first and second washing treatments, and the odor of the stained cloth after washing was evaluated. The results are shown in the table.
[0065] [Table 1]
[0066] [Table 2]
[0067] [Table 3]
[0068] *The mass % of the alkaline agent relative to the textile product, the mass % of the surfactant relative to the textile product, and the pH of the treatment solution in step 2 of Comparative Examples 2 and 4 were the same for the first and second washing treatments, respectively.
Claims
1. A method for washing textile products, comprising the following steps 1 and 2: Step 1: A step of pretreating a soiled textile product by contacting the textile product with a treatment liquid, the treatment liquid containing an alkaline agent, water, and optionally a surfactant, having a pH of 10 or higher, and containing the alkaline agent in an amount of 0.05% by mass or more and 10% by mass or less relative to the mass of the textile product. Step 2: After step 1, increasing the mass of the surfactant contained in the treatment liquid without substantially increasing the mass of the alkaline agent contained in the treatment liquid, and washing the textile product with the treatment liquid.
2. The washing method according to claim 1 , wherein the step 1 and the step 2 are carried out in the same treatment tank.
3. 3. The washing method according to claim 1, wherein the alkaline agent is one or more compounds selected from the group consisting of alkali metal hydroxides, alkali metal silicates, alkali metal carbonates, organic amine compounds, and alkali metal hydrogen carbonates.
4. 3. The washing method according to claim 1, wherein the alkaline agent is one or more compounds selected from alkali metal hydroxides, alkali metal silicates, and alkali metal carbonates, and one or more compounds selected from alkali metal hydrogen carbonates.
5. The washing method according to claim 1 or 2, wherein the increase in the mass of the surfactant in step 2 is carried out by adding a detergent containing a surfactant to the treatment liquid.