JP2002105854A - Method for improving water absorbency of natural fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently improve the water absorbency of natural fibers. SOLUTION: This method for improving the water absorbency of the natural fibers is characterized by treating the natural fibers with a solution comprising a rhamnolipid. In the method, a treatment with an enzyme may further be used in combination.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for treating natural fibers. More specifically, the present invention provides a method for improving the water absorption of natural fibers containing both vegetable fibers such as cotton and animal fibers such as wool.

[0002]

2. Description of the Related Art Natural fibers are scoured for the purpose of improving dyeability during processing and improving the moisture absorption and texture of the final product.

For example, for scouring cotton, a method has conventionally been used in which fibers are immersed in sodium hydroxide to which an auxiliary agent such as a surfactant is added, and treated at a high temperature (90 ° C. or higher). However, this method involves cost problems such as high energy consumption and necessity of neutralization of wastewater. In addition, environmental protection,
Improvement of the process is also desired from the viewpoint of energy saving.

[0004] From such a viewpoint, a scouring method using an enzyme has been proposed (Ryohei Yamamoto, "Dyeing Industry", Vol. 48, No. 6).
4 (2000)). Pectinase is mainly used as the enzyme, and scouring can be performed under mild conditions near neutrality (50 to 65 ° C.). Low energy costs and no need for wastewater neutralization. In addition, in the treatment with sodium hydroxide, a large amount of neutralized salt is generated due to the neutralization of the waste liquid, which is discharged into rivers. However, the wastewater component when enzymes are used is mainly composed of biodegradable organic substances. It can be completely purified by equipment.

However, the method using an enzyme is mild,
The removal rate of impurities in the primary film is not always good. What is particularly problematic in such mild scouring is that wax and fat cannot be sufficiently removed and water absorption is poor. For this reason, there is a problem that defective products are generated in the dyeing process. In order to sufficiently remove such waxes and fats, it is conceivable to use a surfactant, but a synthetic surfactant has a high load in wastewater treatment, and there is a problem in terms of environmental conservation when used in large quantities. .

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a method for effectively improving the water absorption of natural fibers.

SUMMARY OF THE INVENTION The present invention provides a method for improving the water absorption of natural fibers, comprising treating the natural fibers with rhamnolipid. The present invention further provides a method for scouring vegetable fiber, which comprises treating with rhamnolipid in enzymatic scouring of vegetable fiber.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Natural fibers that can be treated by the method of the present invention are not particularly limited, but include cotton, wool, silk,
Hemp, hemp and the like are exemplified. Examples of the form of the fiber that can be treated include an unprocessed fiber and a processed product thereof, that is, a yarn, a woven fabric, a knitted fabric, and a nonwoven fabric. It can also be applied to blends of synthetic fibers and natural fibers, mixed fiber materials, etc.

[0008] The method of the present invention is particularly preferably used in a treatment for improving the water absorption of vegetable fibers.

The rhamnolipid used in the present invention is a combination of rhamnose or its oligosaccharide and a fatty acid, and is said to have the strongest emulsifying power as a currently known surfactant. It is known that there are four types of rhamnolipids depending on the combination of sugar and fatty acid.
In the method of the present invention, any rhamnolipid may be used.

[0010]

Embedded image

Embedded image

The rhamnolipids are preferably used alone or as a mixture having an arbitrary mixing ratio.
R1 rhamnolipid has a surface tension of 27 mN / m, an interfacial tension of 0.05 mN / m, and a critical micelle formation concentration of 5.0.
It has a property of mg / l.

[0012] Rhamnolipids are known to be produced by microorganisms. Examples of the microorganism include rhamnolipid-producing bacteria belonging to the genus Pseudomonas, for example, Pseudomonas aeruginosa.

The rhamnolipid used in the present invention is obtained by culturing a microorganism in a medium to which a necessary nutrient such as glycerin, glucose, ethanol or the like and a nitrogen source are added, and determining the rhamnolipid accumulated in the medium by a conventional method. Obtained by isolation and purification. In particular, Patent No. 292
No. 3756, a method of culturing rhamnolipid-producing bacteria belonging to the genus Pseudomonas in a medium containing 3% or less of ethanol, a yeast extract and soybean flour as a nitrogen source, and collecting rhamnolipid from the culture Is particularly preferably used.

In the present invention, "treating with rhamnolipid" means that a solution containing rhamnolipid is allowed to act on natural fibers. The manner in which the solution containing rhamnolipid is applied is not limited, and may be immersed in the solution, sprayed with the solution on the fibers, or simultaneously with the enzymatic scouring treatment of the fibers to be treated.

Although the concentration of the rhamnolipid solution depends on the purity of the rhamnolipid, 0.001% to 1%, preferably 0.01% to 0.1% is sufficient.

The pH of the rhamnolipid solution is preferably 5 or more, particularly preferably 5 to 10. For pH adjustment, a buffer well known to those skilled in the art, such as a phosphate buffer, a Tris buffer, and a glycine-NaOH buffer, may be used as a medium for the solution.

The temperature of the solution at the time of the treatment is not particularly limited, and it is usually preferable to carry out the treatment at 30 to 80 ° C., particularly preferably at 40 to 70 ° C. The treatment time should be appropriately selected depending on the concentration of rhamnolipid, the treatment temperature, the treatment object and the purpose of the treatment, but is usually 1 to 60 minutes.

In the method of the present invention, when treating a glued material such as cotton fabric, a pretreatment is performed prior to the treatment to remove the glue, or a treatment is performed using a rhamnolipid solution to which a desizing agent is added. May be. As the desizing agent, any of those used in ordinary desizing processes are suitably used, and an α-amylase-containing enzyme agent is exemplified.

The rhamnolipid solution of the present invention may contain a chelating agent. The chelating agent is not particularly limited as long as it is a substance having an effect of sequestering a metal ion. For example, ethylenediaminetetraacetic acid, ethyleneglycolbis (2-aminoethylether) tetraacetic acid, diethylenetriaminepentaacetic acid, hydroxyethylenediaminetriacetic acid,
Citric acid and nitrilotriacetic acid.

The rhamnolipid solution of the present invention may further contain components conventionally added to a fiber treatment solution as long as the effects of the present invention are not affected. Examples of such components include small amounts of organic solvents (ethanol, methanol, glycerin, etc.).

Further, other auxiliaries as described above may be added to further increase the water absorption. The auxiliary agent is not particularly limited as long as it is conventionally used for treating fibers.

When the natural fiber to be treated in the method of the present invention is a vegetable fiber, the treatment with rhamnolipid is
It is preferable to use in combination with treatment with an enzyme. By using a treatment with an enzyme in combination, a natural fiber having further improved water absorption can be obtained.

The fibers that can be treated in this embodiment of the present invention are not particularly limited, as long as they are vegetable fibers. For example, vegetable fibers such as cotton fibers, rayon, hemp, hemp, etc. are exemplified. Is done. Further, the scouring method of the present invention can be applied to such fibers and processed products thereof, that is, yarns, woven fabrics, knitted fabrics, and nonwoven fabrics. One or two more
It can also be applied to blended and interwoven fiber materials composed of a combination with at least one kind of noncellulosic fiber.

As the enzyme used in the method of the present invention, any of various carbohydrate-degrading enzymes conventionally used for scouring vegetable fibers can be suitably used. Such enzymes include, for example, polygalacturonase, C
Examples thereof include MC-decomposing enzymes, hemicellulases, xylanases, and other various glycosidases. Other examples include protease, peptidase, and lipase.
Enzymes may be appropriately selected from commercially available ones, or may be appropriately separated from cultures of known microorganisms producing each enzyme and used. These enzymes may be used in combination of two or more depending on the type of fiber and the purpose of scouring.

The concentration of the enzyme may be appropriately selected depending on the titer and the purpose of the treatment. For example, when a commercially available pectinase is used, it is preferable that the enzyme solution contains 0.001% to 1%.

In the method of the present invention, rhamnolipid is added to a solution containing an enzyme. In the conventional enzyme scouring method, a surfactant was added to the enzyme solution.However, since the rhamnolipid used in the present invention has a very strong emulsifying power, it shows a remarkable effect in a small amount, and the obtained cloth absorbs water. Notably increases gender.

As treatment conditions when treating with a rhamnolipid solution containing an enzyme, appropriate treatment conditions may be selected according to the titer, optimal pH, optimal temperature, etc. of each enzyme known in the art. Not limited.

In the method of the present invention, before or after the treatment with the solution containing rhamnolipid, it may be subjected to treatment with a conventionally known enzyme solution.

Now, the present invention will be described in further detail with reference to Examples. This example is illustrative and does not limit the invention in any way. Preparation of rhamnolipid Rhamnolipid-producing bacteria, Pseudomonas aeruginosa
The culture supernatant of IFO3924 was adjusted to pH 4 with hydrochloric acid to obtain a precipitate of rhamnolipid. This was dissolved in caustic soda at pH 10, and then re-precipitated with hydrochloric acid to pH 4, followed by freeze-drying. The obtained rhamnolipid was a mixture of R1 and R2, the ratio of both was 1: 1 by molar ratio, and the purity was 95%.
Met. The following examples were performed using this rhamnolipid.

[0030]

EXAMPLE 1 1 m (220 g) of a 100% cotton fabric was treated with a desizing agent according to a conventional method. This is 20% containing rhamnolipid 0.01% to 0.1%, 1 mM EDTA.
mM phosphate buffer (pH 7)
Stirring was performed for 0 minutes. After the treatment, the water absorption rate of the washed and air-dried cotton cloth was measured.

Measurement of Water Absorption Speed Ratio The water absorption speed was the time when the cotton cloth was in contact with the water surface and the water rose to a height of 3 cm. The water absorption rate ratio was the same as the water absorption rate of the cotton cloth treated in Example 3 except that 40 g of the same cotton cloth was immersed in 3.2 L of a 1% aqueous solution of sodium hydroxide and subjected to stirring at 90 ° C. for 30 minutes to remove impurities. It is divided by the water absorption rate, and the reciprocal is multiplied by 100. The higher the water absorption rate ratio, the higher the degree of removal of impurities such as wax.

The water absorption rate ratios measured by the above method were 30%, 46% and 60% when treated with a solution containing 0.01%, 0.03% and 0.1% of rhamnolipid, respectively. .

[0033]

Comparative Example 1 As a comparative example, Example 1 was repeated except that rhamnolipid was changed to 0.01% of Sunmol BK-57NM which is a surfactant conventionally used for processing natural fibers.
The water absorption rate ratio of the same treatment was measured. The water absorption rate ratio was between 10 and 20%.

[0034]

Example 2 As in Example 1, 100% cotton woven fabric 1 m
(220 g) was subjected to a desizing treatment. Pectinase (protopectinase Nagase, Nagase Seikagaku Corporation) was diluted 2000 times with 20 mM phosphate buffer (pH 8),
To this enzyme solution, rhamnolipid is 0.01%, 0.03%
And 0.1% of a treatment liquid added thereto.
Dip the above desizing cloth into 2 L of each treatment liquid,
The mixture was stirred at 30 ° C. for 30 minutes.

After the treatment, the water-absorbing speed ratio of the washed and air-dried cloth is 50%, 65% and 72% for rhamnolipid 0.01%, 0.03% and 0.1%, respectively.
Met.

[0036]

Comparative Example 2 As a comparative example, a solution containing no surfactant and a solution containing 0.01% of a conventionally used surfactant Sunmol BK-57NM in the same enzyme solution as in Example 2 were used. It was prepared and subjected to the same treatment as in Example 2.

When the treatment was carried out with a treatment solution containing no surfactant, uniform treatment could not be carried out. The water absorption rate ratio when using the surfactant Sunmol BK-57NM is 24.
%Met.

[0038]

Example 3 As in Example 1, 100% cotton fabric 1m
(220 g) was subjected to a desizing treatment. A 500-fold diluted solution of an enzyme for fruit juice clarification (Pectinex (Hemicellulase), Novo Nordix Bio Industries Co., Ltd.) was prepared in a 20 mM phosphate buffer (pH 4). The desiccated cotton cloth was put into 2 L of a treatment liquid containing 0.1% of rhamnolipid and 10 mM of EDTA, and the mixture was stirred at 55 ° C. for 30 minutes.

After the treatment, the water-washed and air-dried cloth had a water absorption rate ratio of 88%. In addition, when the treatment was performed with an enzyme solution to which rhamnolipid was not added, uniform treatment could not be performed.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yukitoshi Maeda 14-5 Shimogita-cho, Neyagawa-shi, Osaka Kurashiki Textile Co., Ltd. (72) Inventor Hideo Nomura 1-6-42 Enzo, Chigasaki-shi, Kanagawa (72) Inventor Higashi Watanabe 3-1-3-33-113, Jonan, Fujisawa-shi, Kanagawa F-term (reference) 4L031 AA02 AB01 BA39 DA08 4L033 AA02 AB01 AC07 BA09 BA99 CA08

Claims (7)

[Claims] 1. A method for improving the water absorption of natural fibers, comprising treating natural fibers with a solution containing rhamnolipid. 2. The natural fiber is a vegetable fiber.
The described method. 3. The rhamnolipid has the following formula: And The method according to claim 1, which is a mixture of compounds represented by the following formula: 4. The method according to claim 1, wherein rhamnolipid is contained in the solution containing rhamnolipid in an amount of 0.001% to 1%. 5. The method according to claim 2, further comprising a step of treating with a solution containing an enzyme. 6. The enzyme according to claim 5, wherein the enzyme is one or more enzymes selected from the group consisting of pectinase, polygalacturonase, CMC-degrading enzyme, hemicellulase, xylanase, protease, peptidase and lipase. Method. 7. The method according to claim 6, wherein the enzyme is selected from the group consisting of pectinases and hemicellulases.