Water-repellent fabric, water-repellent garment, and method for producing water-repellent fabric

Abstract

To provide a water-repellent fabric that exhibits high water repellency and laundering durability without use of a fluorine-based water repellent, a method for producing the water-repellent fabric, and a water-repellent garment using the water-repellent fabric.SOLUTION: A water-repellent fabric containing cotton, the water-repellent fabric containing an alkyl ketene dimer, containing no fluorine-based compound and no silicone-based compound, and having water absorbency of 400 seconds or more as measured in accordance with JIS L 1907 after performing a washing test 30 times in conformity with JIS L1930 Annex F C4M method.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a water-repellent fabric that has high water-repellent properties and washing durability despite not using a fluorine-based water-repellent agent, a method for producing the water-repellent fabric, and water-repellent clothing using the water-repellent fabric. [Background technology]

[0002] Clothing is required to have various properties depending on its use, and one of the properties required for clothing is water repellency. Conventionally, methods for imparting water repellency to clothing have been known, for example, by attaching a fluorine-based compound to the clothing. For example, Patent Document 1 discloses a method for attaching a fluorine-based water and oil repellent to clothing, and Patent Document 2 discloses a method for attaching a fluoroalkylchlorosilane to clothing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-040026 [Patent Document 2] Japanese Patent Application Publication No. 09-087967 Summary of the Invention [Problem to be solved by the invention]

[0004] However, many of the fluorine-based compounds used in Patent Documents 1 and 2 are persistent, and from the viewpoint of environmental impact, water-repellent clothing that does not use fluorine-based compounds is desired. Accordingly, research into non-fluorine-based water repellents that do not contain fluorine has been progressing in recent years, but clothing that uses conventional non-fluorine-based water repellents has the problem that the water-repellent properties are insufficient or, even if they are excellent, the water-repellent properties are significantly reduced by washing.

[0005] In view of the above-mentioned current situation, an object of the present invention is to provide a water-repellent fabric that has high water-repellent performance and washing durability despite not using a fluorine-based water repellent agent, a method for producing the water-repellent fabric, and water-repellent clothing using the water-repellent fabric. [Means for solving the problem]

[0006] The present invention relates to a water-repellent fabric containing cotton, which contains an alkyl ketene dimer but does not contain a fluorine-based compound or a silicone-based compound, and which has a water absorption time (hereinafter simply referred to as water absorption) of 400 seconds or longer as measured in accordance with JIS L 1907 after 30 washing cycles in accordance with JIS L 1930 Appendix F C4M method. The present invention will be described in detail below.

[0007] The water-repellent fabric of the present invention comprises cotton. By using cotton as the main material of the water-repellent fabric and using alkyl ketene dimer, which will be described later, as the water-repellent agent, it is possible to produce a water-repellent fabric that exhibits high water repellency while also having excellent washing durability.

[0008] The water-repellent fabric of the present invention may be in the form of a woven fabric, a knitted fabric, a nonwoven fabric, etc. The fiber structure may be a mixed fiber, a mixed spinning, a mixed weave, a mixed weave, or a mixed knit.

[0009] The content of the above-mentioned cotton fibers (cellulose fibers) in the total fibers contained in the water-repellent fabric of the present invention is not particularly limited as long as cotton fibers are the main component, i.e., the proportion of cotton fibers exceeds 50%, but from the viewpoints of strength and feel, it is preferably 90%, and more preferably 100%.

[0010] The water-repellent fabric of the present invention contains an alkyl ketene dimer. Alkyl ketene dimer is a compound having a structure represented by the following general formula (1). By using alkyl ketene dimer as the water-repellent component and using cotton (cellulose fiber) as the main material of the fabric, it is possible to produce a water-repellent fabric that has high water repellency and excellent washing durability, even without using a fluorine-based water repellent. Furthermore, the use of alkyl ketene dimer can also reduce deterioration in the texture and color of the fabric compared to when conventional fluorine-based or non-fluorine-based water repellents are used.

[0011] [ka] Here, n represents an integer of 1 or more.

[0012] The length of the alkyl chain of the alkyl ketene dimer, i.e., n in the general formula (1) is preferably 12 or more and 16 or less. By setting the length of the alkyl chain of the alkyl ketene dimer within the above range, water repellency can be further improved. From the same viewpoint, n in the general formula (1) is more preferably 14 or more.

[0013] The amount of the alkyl ketene dimer attached to the water-repellent fabric of the present invention is preferably 0.4% owf or more and 1.5% owf or less. By having the alkyl ketene dimer content within this range, it is possible to further increase water repellency and further prevent the water repellency from decreasing after repeated washing. The amount of the alkyl ketene dimer attached is more preferably 0.6% owf or more and more preferably 1.0% owf or less. In this specification, the unit "% owf" means % by weight relative to the fabric weight.

[0014] The water-repellent fabric of the present invention does not contain fluorine-based compounds or silicone-based compounds. Fluorine-based compounds are the water-repellent components of conventionally used fluorine-based water repellents. While they have excellent properties, such as high water-repellency and washing durability, they suffer from problems such as poor texture and color, and are persistent and environmentally hazardous. Silicone-based compounds are one type of water-repellent component used in conventional non-fluorine-based water repellents, but they lack sufficient water-repellency and washing durability, and they are also persistent. The water-repellent fabric of the present invention can exhibit high water-repellency and washing durability using only alkyl ketene dimers without using fluorine-based or silicone-based compounds, thereby avoiding the problems associated with fluorine-based and silicone-based compounds and reducing costs. Examples of the fluorine-based compounds include water-repellent components containing fluorine, such as fluoroalkylchlorosilanes. Examples of silicone-based compounds include water-repellent components containing siloxane bonds, such as silicone resins and silicone oils.

[0015] The water-repellent fabric of the present invention has a water absorbency of 400 seconds or more as measured in accordance with JIS L 1907 after 30 washing cycles in accordance with the C4M method of Appendix F of JIS L 1930. When the water absorbency measured by the above method is within the above range, both high water repellency and washing durability can be achieved. The upper limit of the water absorbency is not particularly limited, and the higher the better, but considering the water repellency of a water-repellent fabric using an alkyl ketene dimer before washing, the upper limit is about 1800 seconds.

[0016] The water absorbency can be adjusted by the composition of the processing solution and the processing step when the alkyl ketene dimer is attached to the cotton-containing fabric. More specifically, the water absorbency can be adjusted by the content of alkyl ketene dimer in the processing solution, the pH of the processing solution, the bath ratio, whether or not a drying step is performed, the temperature and time of the drying step, the temperature and time of the heating step, etc.

[0017] The water-repellent fabric of the present invention may contain components other than the above-mentioned fluorine-based compounds and silicone-based compounds, as long as the effects of the present invention are not impaired.

[0018] The water-repellent fabric of the present invention can be produced by padding a cotton-containing fabric (hereinafter simply referred to as fabric) in a processing solution containing an alkyl ketene dimer, optionally followed by a drying step and then a heat treatment (curing). This method for producing a water-repellent fabric of the present invention, which includes a padding step in which a processing liquid containing an alkyl ketene dimer is impregnated into a cotton-containing fabric, and a curing step in which the cotton-containing fabric is subjected to a heat treatment after the padding step, also constitutes one aspect of the present invention.

[0019] The method for producing a water-repellent fabric of the present invention first involves a padding step in which a processing solution containing an alkyl ketene dimer is impregnated into a cotton-containing fabric. The processing solution containing alkyl ketene dimer is sprayed onto the fabric, or the fabric is immersed in the processing solution containing alkyl ketene dimer and squeezed with a mangle to allow the processing solution to penetrate the entire fabric. In this case, the water absorbency of the resulting water-repellent fabric can be easily adjusted to the above range by adjusting the composition and bath ratio of the processing solution used in the padding step. Examples of the solvent for the processing solution include water.

[0020] The alkyl ketene dimer content in the processing solution is preferably 5.0 g / L or more and 15.0 g / L or less. By setting the alkyl ketene dimer content in the processing solution within this range, the alkyl ketene dimer adheres better to the fabric, improving water repellency and making it easier to adjust the water absorbency to within the above range. From the same perspective, the alkyl ketene dimer content in the processing solution is more preferably 6.7 g / L or more and more preferably 10.0 g / L or less.

[0021] The pH of the processing solution is preferably 4.5 or more and 10.0 or less. By setting the pH of the processing solution within this range, the alkyl ketene dimer can penetrate further into the fabric, improving water repellency and making it easier to adjust the water absorbency to the above range. Damage to the fabric can also be reduced. From the same perspective, the pH of the processing solution is more preferably 4.5 or more and more preferably 7.0 or less. Note that examples of additives for adjusting the pH include sodium hydroxide.

[0022] The bath ratio (ratio of the weight of the processing solution to the weight of the fabric) when immersing the fabric in the processing solution is preferably 10 or more and 50 or less. By setting the bath ratio within this range, the alkyl ketene dimer can penetrate further into the fabric, improving water repellency and making it easier to adjust the water absorbency to within the above range. From the same perspective, the bath ratio is more preferably 15 or more and more preferably 20 or less.

[0023] The PU value during the padding (pickup: the percentage of the weight increase of the fabric after soaking in the treatment solution and draining it, relative to the weight of the untreated fabric) is preferably 90% or more and 120% or less. By setting the PU value within this range, it becomes easier to adjust the water absorbency to within the above range. From the same perspective, the PU value is more preferably 100% or more, and more preferably 110% or less.

[0024] In the method for producing the water-repellent fabric of the present invention, a drying step may be carried out between the padding step and the curing step described below, if necessary. When the drying step is carried out, the water absorbency can be easily adjusted to the above range by adjusting the temperature and time of drying.

[0025] The temperature in the drying step is preferably 80°C or higher and 120°C or lower. By setting the temperature in the drying step within this range, the alkyl ketene dimer can adhere better to the fabric, improving water repellency, and the water absorbency can be easily adjusted to the above range. Damage to the fabric can also be reduced. From the same perspective, the temperature in the drying step is more preferably 105°C or higher.

[0026] The drying time is preferably 3 minutes or more and 5 minutes or less. By setting the drying time within this range, the alkyl ketene dimer can adhere better to the fabric, improving water repellency and making it easier to adjust the water absorbency within the above range. Damage to the fabric can also be reduced.

[0027] In the method for producing a water-repellent fabric of the present invention, a curing step is then carried out in which the cotton-containing fabric after the padding step is subjected to a heat treatment. By subjecting the fabric after the padding step (or the fabric after the drying step, if the drying step has been performed) to a heat treatment, the alkyl ketene dimer attached to the fabric is fixed, improving durability to washing, etc. The water absorbency can also be easily adjusted to the above range by adjusting the temperature and time of the heat treatment.

[0028] The temperature of the curing step is preferably 105°C or higher and 140°C or lower. By setting the temperature of the curing step within this range, the alkyl ketene dimer can adhere better to the fabric, improving water repellency, and the water absorbency can be easily adjusted to the above range. Damage to the fabric can also be suppressed. From the same perspective, the temperature of the curing step is more preferably 120°C or higher.

[0029] The curing time is preferably 3 minutes or more and 10 minutes or less. By setting the curing time within this range, the alkyl ketene dimer can adhere better to the fabric, improving water repellency and making it easier to adjust the water absorbency to the above range. Damage to the fabric can also be reduced. From the same perspective, the curing time is more preferably 5 minutes or more.

[0030] In the method for producing a water-repellent fabric of the present invention, a washing step may be carried out after the curing step. The washing step may be carried out under the same conditions as in the past, for example, by washing with hot water at 60°C or by rinsing with water.

[0031] The method for producing the water-repellent fabric of the present invention is not limited to the above method, and methods such as printing a processing liquid onto the fabric and textile printing can also be used as appropriate.

[0032] The water-repellent fabric of the present invention has excellent properties, such as high water repellency and washing durability, and is less likely to impair the texture of the material, such as softness and color change. By using such a water-repellent fabric of the present invention, clothing with high water repellency and washing durability can be obtained. Water-repellent clothing made from the water-repellent fabric of the present invention also constitutes one aspect of the present invention. Specific examples of the water-repellent clothing of the present invention include outdoor wear, sportswear, loungewear, pajamas, sleepwear, underwear, office wear, workwear, foodservice uniforms, nursing uniforms, patient wear, care wear, school uniforms, kitchen wear, pantyhose, tights, socks, etc. [Effects of the Invention]

[0033] According to the present invention, it is possible to provide a water-repellent fabric that has high water-repellent performance and washing durability despite not using a fluorine-based water repellent agent, a method for producing the water-repellent fabric, and water-repellent clothing using the water-repellent fabric. DETAILED DESCRIPTION OF THE INVENTION

[0034] The following examples will explain the present invention in more detail, but the present invention is not limited to these examples.

[0035] Example 1 (Manufacturing water-repellent fabrics) The raw material was a circular knit fabric (100% cotton) made by ribbing 40-count cotton fibers. First, alkyl ketene dimer (AD1608, manufactured by Seiko PMC, denoted as AKD in the table) was added to water to a concentration of 5.0 g / L to prepare an alkyl ketene dimer processing solution (pH: 4.5). The circular knit fabric was then immersed in the processing solution and padded by squeezing with a mangle to achieve a PU value of 100. The fabric was then cured in a tenter at 120 °C for 10 minutes to obtain a water-repellent fabric.

[0036] (Examples 2 and 3 and Comparative Example 1) A water-repellent fabric was obtained in the same manner as in Example 1, except that the concentration of the processing solution was as shown in Table 1.

[0037] (Comparative Example 2) A circular knit fabric (100% cotton) made by ribbing 40 count cotton fibers was used as is.

[0038] (Comparative Example 3) The raw material was a circular knit fabric (100% cotton) made by ribbing 40-count cotton fibers. A water-repellent solution was prepared by adding a fluorine-based water repellent (NK Guard S05, manufactured by Nicca Chemical Co., Ltd.; referred to as "fluorine-based" in the table) and a crosslinker (NK Assist NY50, manufactured by Nicca Chemical Co., Ltd.; referred to as "NY50" in the table) to water at concentrations of 60 g / L and 6.0 g / L, respectively. The circular knit fabric was then immersed in the solution and padded by squeezing with a mangle to achieve a PU value of 100. The fabric was then dried in a tenter at 120 °C for 3 minutes and cured in a tenter at 160 °C for 1 minute to obtain a water-repellent fabric.

[0039] Comparative Example 4 A water-repellent fabric was obtained in the same manner as in Comparative Example 3, except that the composition and concentration of the processing liquid were as shown in Table 1. Details of the non-fluorine-based water repellent agents in the table are as follows. Non-fluorine type: Neoseed NR-3100, a non-fluorine type water repellent other than alkyl ketene dimer, manufactured by Nicca Chemical Co., Ltd.

[0040] <Evaluation> The water-repellent fabrics obtained in the examples and comparative examples were evaluated by the following methods. The results are shown in Table 1.

[0041] (1) Water absorption evaluation The water absorbency of the resulting water-repellent fabric was measured using the drop method in accordance with JIS L-1907. Specifically, a 200mm x 200mm test specimen was attached to a test specimen holder, and the distance from the test specimen surface to the tip of a burette was adjusted to 10mm. A single drop of water was dropped from the burette, and the time from when the drop landed on the test specimen until it was completely absorbed by the test specimen was measured. If the drop was not absorbed at all, a predetermined time was recorded. This procedure was repeated five times, and the average value was taken as the water absorbency before washing. Next, a washing test in accordance with JIS L1930 Appendix F C4M method was repeated 30 times, and the water absorbency after 30 washes was measured in the same way as before washing. Note that a higher value indicates better water repellency.

[0042] (2) Whiteness evaluation The whiteness of the water-repellent fabric before washing was evaluated by measuring the whiteness and whiteness loss of each sample before and after bone-drying, calculated as L*-3b* using the CIELAB color system. Note that the whiteness after bone-drying was measured after measuring the bone-dry weight according to JIS L-0105 4.3. Measurements were also performed on a small area using a Macbeth WHITE-EYE 3000 manufactured by Kollmorgen Instruments Corporation.

[0043] (3) Evaluation of stiffness The bending resistance of the water-repellent fabric before washing was measured according to the method of JIS L-1096 8.21 E method.

[0044] [Table 1] [Industrial Applicability]

[0045] According to the present invention, it is possible to provide a water-repellent fabric that has high water-repellent performance and washing durability despite not using a fluorine-based water repellent agent, a method for producing the water-repellent fabric, and water-repellent clothing using the water-repellent fabric.

Claims

1. A water-repellent fabric containing cotton, which contains an alkyl ketene dimer but does not contain a fluorine-based compound or a silicone-based compound, and which has a water absorbency of 400 seconds or more as measured in accordance with JIS L 1907 after 30 washing cycles in accordance with JIS L 1930 Appendix F C4M method.

2. A water-repellent garment made from the water-repellent fabric according to claim 1.

3. 2. The method for producing the water-repellent fabric according to claim 1, comprising: a padding step in which a processing solution containing an alkyl ketene dimer is impregnated into a cotton-containing fabric; and a curing step in which the cotton-containing fabric is subjected to a heat treatment after the padding step.

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