JP2007084947A - Method for refining - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for refining silk raw woven fabric, twisted yarn obtained by twisting raw silk, raw silk composing the silk raw woven fabric, completely removing sericin without over refinement from the raw silk which has a structure of packaging two fibroin, a fibrous protein, with sericin in glue state and contains substances and impurities excluding the sericin. <P>SOLUTION: The method uses an acidic refining liquid comprising an inorganic acid and having an initial pH of 1-2 at ≥90°C to refine the raw silk, twisted yarn obtained by twisting the raw silk or silk raw woven fabric. The acidic refining liquid preferably contains an organic acid and soap, etc., are also preferably used. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is a scouring method for scouring raw yarn, twisted yarn obtained by twisting raw yarn, or raw fabric.

  Silk fiber has a structure in which two fibroins, which are fibrous proteins, are wrapped with glue-like sericin, and further contains impurities and impurities other than sericin. Such raw silk made of silk fibers, twisted yarn obtained by twisting raw silk, and raw fabric must be subjected to scouring to remove sericin, impurities and impurities in order to obtain a silk-like texture such as silk squealing.

  Examples of scouring methods for scouring silk fibers include alkali scouring methods, soap scouring methods, soap / alkali scouring methods, enzyme scouring methods, high-pressure scouring methods, and acid scouring methods.

  The alkali scouring method is a method of scouring silk fibers using an alkaline scouring solution containing basic substances such as sodium carbonate (sodium carbonate), sodium silicate (sodium silicate), and tertiary phosphate (sodium tertiary phosphate). . Examples of the alkali scouring method include mash mash using rice and wheat ash. In the alkaline scouring method, an alkaline scouring solution having a very high solubility in sericin is used, so that sericin can be easily removed. However, it tends to be in a state of excessive scouring of silk fibers. Over-scoured silk fibers not only have sericin removed, but also have fibroin that is not very resistant to bases being damaged. Therefore, the silk fiber may generate fuzz, the strength and elongation of the fiber may decrease, and the texture such as flexibility and touch may be deteriorated.

  The soap scouring method is a method of scouring silk fibers using a scouring solution containing soap as a surfactant. The soap scouring method can remove sericin with soap contained in the scouring solution. However, if the scouring liquid is hard water containing a large amount of metal ions, the soap and metal ions are combined to produce a metal soap (scum) that is insoluble in water. When the produced scum adheres to the silk fiber, it is difficult to remove, and the scum adversely affects dyeing and the like. Therefore, the soap scouring method needs to use soft water with less metal ions as scouring water used when preparing a scouring solution.

  Moreover, since the soap has a high affinity with the silk fiber, the soap remains attached to the silk fiber unless the bath is sufficiently washed with hot water and water after scouring. The soap that remains attached to the silk fibers has an adverse effect on the yellowing and dyeing of the silk, so it is necessary to carefully wash with hot water and water after scouring.

  The soap / alkali scouring method is a method of scouring silk fibers using an alkaline scouring liquid containing soap and a basic substance. The soap / alkali scouring method can compensate for the disadvantages of the alkali scouring method and the soap scouring method by optimizing the contents of the soap and the basic substance. However, in the soap / alkali scouring method, sericin is decomposed by the scouring solution to generate a large amount of amino acids, and further, the fatty acid that is the raw material of soap is decomposed by the scouring solution that is basic, and hydrocarbons such as normal hexane. Will occur. Therefore, a scouring waste liquid containing a large amount of contaminants and having a high BOD (biochemical oxygen demand) and COD (chemical oxygen demand) is discharged as waste water.

  In addition, when scouring raw yarn twisted with a cationic twisting agent using the soap scouring method and soap / alkali scouring method, an anionic soap is used, so soap scum is generated, and the soap scum However, it may adversely affect dyeing.

  The enzyme scouring method is a method of scouring silk fibers using a scouring solution containing a proteolytic enzyme. Sericin can be decomposed and removed by proteolytic enzymes. However, since the proteolytic enzyme has a limited use temperature, it is very difficult to control the temperature of the scouring solution. In addition, since sericin does not swell or soften at the use temperature of the proteolytic enzyme, a pretreatment with alkali is required to swell and soften sericin. In addition, since proteolytic enzymes are expensive, the drug cost is increased. For these reasons, the enzyme scouring method is not so much used except for some special silk fabrics.

  The high-pressure scouring method is a method of scouring silk fibers under high pressure. By increasing the pressure, sericin can be dissolved even when water is used as a scouring solution. By doing so, sericin is obtained without being degraded so much, and is used for the purpose of obtaining high molecular weight sericin. However, equipment that can withstand high pressure is necessary, and the cost becomes high.

  As described in Non-Patent Document 1, the acid scouring method is a method of scouring silk fibers using an acid scouring solution containing a polyvalent carboxylic acid such as citric acid and malic acid.

Kato Hiroshi, “Processing and application of silk fiber”, 1st edition, Textile Research Co., Ltd., August 10, 1987, p. 27-29

  In the acid scouring method, sericin is dissolved more slowly than in the alkaline scouring method, so that the degree of sericin removal is easily controlled. In order to obtain a hard-to-feel thread, etc., 3 parts kneading, 5 parts kneading, 7 parts kneading, etc. are carried out to leave some sericin. In such a case, an acid scouring method that can easily control the degree of sericin removal is preferably used. In addition, scouring water can be used whether it is soft water or hard water, and even if washing after scouring is insufficient, the silk does not turn yellow, and the adverse effect on dyeing and the like is more negative than the soap scouring method. Few. Without draining a scouring waste liquid having a high BOD and COD as in the soap / alkaline scouring method as waste water, temperature control as in the enzyme scouring method is not required, and equipment that can withstand high pressure as in the high pressure scouring method is not required.

  However, since fibroin has lower acid resistance than base resistance, in the case of over-scouring, the acid scouring method is significantly damaged compared to the alkali scouring method and the like. Therefore, the acid scouring method has not been used other than 3 parts kneading, 5 parts kneading, 7 parts kneading, etc. that leave some sericin.

  The acid scouring method described in Non-Patent Document 1 is a scouring method intended for 3 parts kneading, 5 parts kneading and 7 parts kneading using a scouring solution having a pH of 2 or more. It was not considered to completely remove sericin by the acid scouring method.

  An object of the present invention is to provide a scouring method capable of completely removing sericin without overscouring and damaging silk fibers.

The present invention is a scouring method for scouring raw silk, twisted twisted raw silk or raw fabric,
A scouring method characterized by scouring using an acidic scouring liquid containing an inorganic acid and having an initial pH of 1 or more and less than 2.
Further, the present invention is characterized in that scouring is performed at a temperature of 90 ° C. or higher.

In the invention, the acidic scouring liquid contains an organic acid.
The present invention is characterized in that the acidic scouring liquid contains a surfactant.

Further, the present invention is characterized by scouring at 90 ° C. or higher using a basic scouring liquid having an initial pH of 9 or more and 11 or less after scouring using the acidic scouring liquid.
In the invention, the basic scouring liquid contains a surfactant.

  According to the present invention, there is a scouring method for scouring raw silk, twisted twisted raw silk or raw fabric. Scouring is performed using an acidic scouring liquid containing an inorganic acid and having an initial pH of 1 or more and less than 2.

  By doing so, sericin can be completely removed without over-scouring and damaging the silk fibers.

  Further, when scouring a fiber having low base resistance, particularly wool, is particularly preferable because the fiber having low base resistance can be scoured without being damaged.

  Further, according to the present invention, it is preferable that the acidic scouring liquid is scoured at a temperature of 90 ° C. or higher. By setting the temperature of the acidic scouring solution to 90 ° C. or higher, sericin can be easily swollen and softened, so that sericin can be more easily removed.

  Moreover, according to this invention, it is preferable that an acidic scouring liquid contains an organic acid. By using together an organic acid that is easily compatible with sericin, the sericin can be easily swollen and softened, and the acidic scouring solution easily penetrates into sericin, so that sericin is more easily removed.

  According to the present invention, it is preferable that the acidic scouring liquid contains a surfactant. By including the surfactant, it becomes easier to remove sericin.

  Further, according to the present invention, after scouring using an acidic scouring solution, scouring is performed using a basic scouring solution having an initial pH of 9 or more and 11 or less. By doing so, sericin remaining after scouring with an acidic scouring solution is removed using a basic scouring solution, so that sericin can be completely removed.

  Further, when scouring with a basic scouring solution, the damage to fibroin is small, and this is a particularly preferred scouring method when sericin is completely removed.

  Furthermore, when scouring silk fibers, it is preferable that the silk fibers are basic rather than acidic, so this is also a preferred scouring method when dyeing after scouring.

  According to the present invention, it is preferable that the basic scouring liquid contains a surfactant. By including the surfactant, it becomes easier to remove sericin.

  The present invention is an acid scouring method of scouring raw materials, scoured products such as twisted raw silk or raw fabric using an acidic scouring solution (acid scouring solution), and scouring with an increased degree of removal of sericin Is the method.

  FIG. 1 is a diagram showing silk fibers (raw silk) 10 before scouring, and FIG. 2 is a diagram showing scoured silk after scouring silk fibers. As shown in FIG. 1, one silk fiber 10 forming a cocoon has a structure in which two fibroin 11 having a cross section close to a triangle is wrapped with glue-like sericin 12. When this silk fiber 10 is scoured, as shown in FIG. 2, sericin 12 is removed and two fibroin 11 are obtained as scoured silk. The present invention is a method for removing sericin without damaging fibroin, which is a fibrous protein capable of exhibiting a texture peculiar to silk. It is also used for scouring, and is used not only for the yarn kneading method for scouring raw yarn and twisted yarn, but also for the kneading method for scouring raw woven fabric using raw yarn or twisted yarn before scouring.

FIG. 3 is a diagram showing the steps of the scouring method. First, in the pretreatment A1, the material to be scoured is immersed in hot water or warm water to swell and soften sericin. Next, rough scouring A2, final kneading A3 and finishing kneading A4 are performed three times to remove sericin. In roughing A2, the material to be scoured is immersed in a scouring liquid at 90 ° C. or higher for a predetermined time to remove sericin. The scouring solution here may be the scouring solution used in the main kneading A3, and is performed for the purpose of removing sericin that can be easily removed. In the main kneading A3, the material to be scoured is immersed in a new scouring liquid of 90 ° C. or higher for a predetermined time to remove most of sericin. In the finishing kneading A4, the scoured material is immersed in a new scouring liquid of 90 ° C. or higher for a predetermined time to correct the lack of scouring and the scouring unevenness. Finally, in cleaning A5, the scoured material is immersed in hot water and warm water to wash away the removed sericin and the like.
In the present invention, two kinds of scouring methods, a yarn kneading method and a cloth kneading method, are used.

  First, the case of the yarn kneading method will be described. In the present invention, an acid scouring solution described later is used in roughing A2 and main kneading A3, and a basic scouring solution (alkali scouring solution) described later is used in finishing kneading A4. Moreover, sericin can be sufficiently swollen and softened by immersing the material to be smelted in the acid scouring solution, so that pretreatment A1 is not necessary, and most sericin is removed only by main kneading A3. Therefore, it is not necessary to carry out roughing A2 and finishing kneading A4.

  When scouring using an alkaline scouring liquid is performed in finishing kneading A4, sericin remaining in main kneading A3 can be removed. Therefore, when finishing A4 is performed, scouring deficiency and scouring unevenness can be corrected, and the damage received by fibroin during finishing A4 can be reduced, which is preferable when sericin is completely removed.

  Further, when dyeing the scoured silk fiber, if the silk fiber is acidic, uneven dyeing occurs, so that it is preferably basic. Therefore, in the case of dyeing after scouring, finishing A4 is preferable because it can be dyed evenly without performing the step of neutralizing before dyeing.

  Next, the case of the kneading method will be described. In the present invention, an acid scouring liquid described later is used in roughing A2, and an alkali scouring liquid described later is used in main kneading A3 and finishing kneading A4. Since the sericin can be sufficiently swollen and softened by immersing the material to be scoured in the acid scouring solution, pretreatment A1 is not necessary as in the case of the yarn kneading method, and rough kneading A2 and main kneading A3. Since most of the sericin can be removed, finishing A4 is not necessary.

  The rough kneading A2, the main kneading A3, and the finishing kneading A4 can be performed by a known scouring operation. Instead of the scouring liquid used in the known scouring operation, an acid scouring liquid or an alkaline scouring liquid described later is used. That's fine. Known scouring operations include, for example, manual scouring operations such as a kneading method, a stick kneading method, a hanging kneading method and a bag kneading method, and mechanical scouring operations such as a jet scouring method and a high pressure scouring method.

  The acid scouring solution preferably has an initial pH of 1 or more and less than 2 before starting scouring, and more preferably has an initial pH of 1 or more and less than 1.8. If the initial pH is less than 1, overscouring tends to occur, and if the initial pH is 2 or more, sericin cannot be removed sufficiently. In addition, when an acid scouring solution having an initial pH of 1 or more and less than 2 is used, sericin is dissolved more slowly than when an alkaline scouring solution is used. Can be prevented.

  Further, the acid scouring solution contains an inorganic acid. As the inorganic acid, a known inorganic acid can be used as long as it can realize the preferable range of the initial pH. Examples thereof include sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, phosphorous acid (phosphonic acid) and hypophosphorous acid (phosphinic acid). Further, phosphoric acid that does not corrode the scouring apparatus is particularly preferable. Further, when a scouring solution containing phosphoric acid is used, fibroin is less damaged.

  In addition, since the present invention scours using an acid refinement liquid, when scouring a fiber having low base resistance, particularly union with wool, the fiber having low base resistance can be scoured without being damaged. This is particularly preferable because it can be performed.

  In the case of the yarn kneading method, the concentration of the inorganic acid is preferably 4% OWF or more and 20% OWF or less, more preferably 5% OWF or more and 10% OWF or less. In the case of the cloth kneading method, 0.5 g / L or more and 4 g / L or less is preferable, and 1 g / L or more and 2 g / L or less is more preferable. In addition,% OWF is a percentage with respect to the weight of a fiber.

  Further, the acid scouring solution may contain an organic acid. As the organic acid, a known organic acid can be used as long as it is a water-soluble organic acid. Examples include citric acid, formic acid, acetic acid, lactic acid, malic acid and tartaric acid. Since the organic acid has a higher affinity for sericin than the inorganic acid, when used together with the inorganic acid, the acidic scouring liquid easily penetrates into sericin, so that sericin is more easily removed. Further, the acid scouring solution may contain a surfactant in order to make it easier to remove sericin.

  Scouring is preferably carried out at a temperature of 90 ° C. or higher, and boiling scouring is preferred. By setting the temperature of the acidic scouring solution to 90 ° C. or higher, sericin can be easily swollen and softened, so that sericin can be more easily removed.

  The acid scouring solution is preferably used so that the bath ratio is 1:10 to 1: 100, more preferably 1:20 to 1:40. The bath ratio is the ratio of the total liquid weight when the weight of the fiber is 1.

  In the present invention, since scouring is performed using an acid refinement solution, sericin can be removed without much decomposition. The scouring waste liquid from which sericin has been removed contains high-molecular weight sericin, and gels when the scouring waste liquid from which sericin has been removed is allowed to stand overnight. Therefore, high molecular weight sericin can be recovered. High molecular weight sericin is preferably used in cosmetics and the like.

  The alkaline scouring liquid contains a basic substance, and preferably has an initial pH of 9 or more and 11 or less, and more preferably 9.5 or more and 11 or less before starting scouring. Examples of basic substances include sodium hydroxide (sodium hydroxide), sodium sesquicarbonate (trisodium hydrogencarbonate), sodium tripolyphosphate (sodium triphosphate), and soda ash (sodium carbonate). Further, the alkaline scouring solution may contain a surfactant such as soap in order to make it easier to remove sericin.

  Scouring is preferably performed at an alkali scouring liquid temperature of 90 ° C. or higher, and boiling scouring is preferred. By setting the temperature of the acidic scouring solution to 90 ° C. or higher, sericin can be easily swollen and softened, so that sericin can be more easily removed.

  The alkaline scouring liquid is preferably used so that the bath ratio is 1:10 to 1: 100, more preferably 1:20 to 1:40. The bath ratio is the ratio of the total liquid weight when the weight of the fiber is 1.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.
・ Study on scouring raw silk First, raw silk was scoured only by main kneading.

Example 1
As shown in Table 1, an acid scouring solution containing 5% OWF of 99% by weight sulfuric acid (hereinafter referred to as sulfuric acid) is used so that the bath ratio is 1:20, and raw silk (21/3 pieces) is obtained. Simmered for 40 minutes. Thereafter, it was washed with hot water and further washed with hot water. The initial pH of the acid scouring solution was 1.2. Note that boiling scouring means scouring with a scouring liquid of 90 ° C. or higher. The initial pH of the scouring solution was measured using a pH test paper. The pH test paper to be used differs depending on the pH of the scouring liquid to be measured. If it is an acid scouring liquid, use one of CR (cresol red) test paper, TB (thymol blue) test paper, BPB (bromophenol blue) test paper and BCG (brom cresol green), and if it is an alkaline scouring liquid , AZY (Alizarin Yellow) test paper, TB (thymol blue) test paper and CR (cresol red) test paper were used.

(Example 2)
Example 1 is the same as Example 1 except that 22 Baume's hydrochloric acid (hereinafter referred to as hydrochloric acid) is used instead of sulfuric acid. The initial pH of the acid scouring solution was 1.4.

(Example 3)
It is the same as that of Example 1 except using nitric acid (henceforth nitric acid) with a purity of 60% by weight instead of sulfuric acid. The initial pH of the acid scouring solution was 1.3.

Example 4
Similar to Example 1 except that 8% OWF is included instead of 5% OWF in sulfuric acid. The initial pH of the acid scouring solution was 1.5.

(Example 5)
Similar to Example 1 except that 6% OWF of phosphorous acid is included instead of 5% OWF of sulfuric acid. The initial pH of the acid scouring solution was 1.4.

(Example 6)
The same as Example 1 except that 10% OWF of hypophosphorous acid is contained instead of 5% OWF of sulfuric acid. The initial pH of the acid scouring solution was 1.3.

(Example 7)
Example 1 is the same as Example 1 except that 5% OWF of citric acid and 4% OWF of phosphoric acid are contained instead of 5% OWF of sulfuric acid. The initial pH of the acid scouring solution was 1.6.

(Example 8)
Example 1 is the same as Example 1 except that 5% OWF of malic acid and 2.5% OWF of sulfuric acid are contained instead of 5% OWF of sulfuric acid. The initial pH of the acid scouring solution was 1.4.

Example 9
Example 1 is the same as Example 1 except that instead of using an acid scouring solution containing 5% OWF of sulfuric acid, an acid scouring solution containing 10% OWF of sulfuric acid is used. The initial pH of the acid scouring solution was 1.0.

(Example 10)
Example 3 is the same as Example 3 except that an acid scouring solution containing 10% OWF of nitric acid is used instead of using an acid scouring solution containing 5% OWF of nitric acid. The initial pH of the acid scouring solution was 1.1.

(Example 11)
Example 2 is the same as Example 2 except that an acid scouring solution containing 10% OWF of hydrochloric acid is used instead of an acid scouring solution containing 5% OWF of hydrochloric acid. The initial pH of the acid scouring solution was 1.2.

(Example 12)
Example 4 is the same as Example 4 except that an acid scouring solution containing 20% OWF of phosphoric acid is used instead of an acid scouring solution containing 8% OWF of phosphoric acid. The initial pH of the acid scouring solution was 1.2.

(Example 13)
Example 4 is the same as Example 4 except that instead of using an acid scouring solution containing 8% OWF of phosphoric acid, an acid scouring solution containing 50% OWF of phosphoric acid is used. The initial pH of the acid scouring solution was 1.1.

(Example 14)
Example 4 is the same as Example 4 except that an acid scouring solution containing 100% OWF of phosphoric acid is used instead of an acid scouring solution containing 8% OWF of phosphoric acid. The initial pH of the acid scouring solution was 1.0.

(Comparative Example 1)
Similar to Example 1 except that 10% OWF of citric acid is included instead of 5% OWF of sulfuric acid. The initial pH of the acid scouring solution was 2.4.

(Comparative Example 2)
The same as Comparative Example 1 except that formic acid is used instead of citric acid. The initial pH of the acid scouring solution was 2.4.

(Comparative Example 3)
The same as Comparative Example 1 except that acetic acid is used instead of citric acid. The initial pH of the acid scouring solution was 3.6.

(Comparative Example 4)
The same as Comparative Example 1 except that lactic acid is used instead of citric acid. The initial pH of the acid scouring solution was 2.4.

(Comparative Example 5)
It is the same as that of the comparative example 1 except using malic acid instead of a citric acid. The initial pH of the acid scouring solution was 2.4.

(Comparative Example 6)
It is the same as that of the comparative example 1 except using tartaric acid instead of a citric acid. The initial pH of the acid scouring solution was 2.3.

(Comparative Example 7)
Example 1 is the same as Example 1 except that 10% OWF soap, 2.5% OWF sesquicarbonate and 0.5% OWF sodium tripolyphosphate are used instead of 5% OWF sulfuric acid. The initial pH of the alkaline scouring solution was 10.

(Comparative Example 8)
Similar to Example 1, except that 1% OWF is included instead of 5% OWF in sulfuric acid. The initial pH of the acid scouring solution was 2.7.

(Comparative Example 9)
Similar to Example 1 except that instead of 5% OWF sulfuric acid, 2% OWF phosphoric acid is included. The initial pH of the acid scouring solution was 2.4.

(Comparative Example 10)
Example 1 is the same as Example 1 except that an acid scouring solution containing 25% OWF of sulfuric acid is used instead of an acid scouring solution containing 5% OWF of sulfuric acid. The initial pH of the acid scouring solution was 0.8.

(Comparative Example 11)
Example 3 is the same as Example 3 except that an acid scouring solution containing 25% OWF of nitric acid is used instead of using an acid scouring solution containing 5% OWF of nitric acid. The initial pH of the acid scouring solution was 0.8.

(Comparative Example 12)
Example 2 is the same as Example 2 except that an acid scouring solution containing 25% OWF of hydrochloric acid is used instead of an acid scouring solution containing 5% OWF of hydrochloric acid. The initial pH of the acid scouring solution was 0.9.

[Evaluation methods]
About Examples 1-14 and Comparative Examples 1-12, the reduction rate, elongation, intensity | strength, and texture were measured as follows, and the result is shown in Table 2. Note that symbols such as “◎”, “◯”, “Δ”, and “x” described in the description of the evaluation items are symbols indicating evaluation results used in Table 2. “◎” indicates very good, “○” indicates excellent, “△” indicates that it is practical, and “×” indicates that practical use is difficult. Indicates.

(Reduction rate)
The scoured material before scouring and the scoured material after scouring are dried at 60 ° C. for 1 hour, and the respective weights are measured, whereby the weight A (g) of the scoured material before scouring and the scoured material after scouring. The weight B (g) of the product is obtained. Since silk fibers have a high equilibrium moisture content and easily absorb moisture in the air, the weight is not stable if left in the air, so it is necessary to measure the weight immediately after drying.

Then, the reduction rate is calculated by the following formula.
Reduction rate (%) = (A−B) / A × 100

(Elongation)
Using a shopper type single yarn strong elongation measuring machine (manufactured by Asano Machinery Manufacturing Co., Ltd.), the elongation is calculated as follows.

  FIG. 4 is a diagram illustrating a method for measuring the elongation of the fiber 20. FIG. 4A is a diagram illustrating a state before the fiber 20 is pulled, and FIG. 4B is a diagram illustrating a state immediately before the fiber 20 is broken.

  As shown in FIG. 4A, both ends of the fiber 20 are supported by the jig 21. By measuring the distance between the jigs 21 at that time, the length C (cm) before pulling is obtained. Thereafter, the jig 21 is gradually separated and, as shown in FIG. 4 (b), by measuring the distance between the jigs 21 just before the fiber 20 breaks, the length D (cm) just before the break Get.

And elongation is computed by following Formula. For C and D, an average value of measured values measured 20 times is used.
Elongation (%) = (D−C) / C × 100

(Strength)
When the elongation is measured, the strength (g) of the fiber 20 is obtained by measuring the load applied to the fiber 20 immediately before the fiber 20 breaks. In addition, the intensity | strength (g) of the fiber 20 is an average value of the measured value measured 20 times.

(Texture)
-Flexibility The scoured material after scouring was touched and evaluated as follows.
A: Very soft compared to the material to be scoured before scouring.
○: Compared to the material to be scoured before scouring, it is soft, but has a little core and a little hardness.
(Triangle | delta): It is soft compared with the to-be-scoured material before scouring, but there is a core and hardness remains.
X: Compared with the material to be scoured before scouring, it is not so soft.

-Silkiness Touched the scoured material after scouring and evaluated as follows.
A: There is a feeling of tingling and silkiness occurs.
○: There is a little tingling, and a little silkiness occurs.
X: Silkiness does not occur.

-Gloss The scoured material after scouring was observed and evaluated as follows.
(Double-circle): It is white and there is luster peculiar to silk.
○: White and slightly glossy.
Δ: Yellowish and slightly glossy
X: The same color as raw silk and no gloss.

  As can be seen from Table 2, when scouring using an acid scouring solution containing an inorganic acid and having an initial pH of 1.0 or more and less than 2.0 (Examples 1 to 14), the reduction rate is 25% or more. Yes, the scoured silk became soft enough. From this, it was found that sericin was sufficiently removed. Further, the elongation and strength were sufficiently high, and the scoured silk generated silkiness and had a silk-specific luster. This showed that fibroin was not significantly damaged. From the above, it was found that sericin could be completely removed without over-scouring and damaging the silk fibers. In particular, when scouring with an acid scouring solution containing phosphoric acid (Example 4) and when scouring with an acid scouring solution in combination with an organic acid (Examples 7 and 8), the elongation and strength are higher. it was high. From this, it was found that sericin could be completely removed without further damaging the silk fibers, which was a more preferable scouring method. Further, even when scouring with an acid scouring solution containing a very high concentration of phosphoric acid (Examples 12 to 14), the elongation was 14% or more and the strength was 160 g or more.

  When scouring with an acid scouring solution that contains only organic acids and the initial pH of the scouring solution is 2 or more (Comparative Examples 1 to 6), the reduction rate is lower than 25%, and the scoured silk does not become sufficiently soft. It was. From this, it was found that sericin was not sufficiently removed and not sufficiently refined. When scouring using an alkaline scouring solution containing soap (Comparative Example 7), the reduction rate was 25% or more, and the scoured silk became sufficiently soft. However, no silkiness occurred. From this, it is considered that scum, soap, and the like remain attached to the silk fiber because scouring was performed using an alkaline scouring solution containing soap. When the initial pH of the scouring liquid was 2 or more (Comparative Examples 8 and 9), the reduction rate was lower than 25%, and the scoured silk was not sufficiently soft. From this, it was found that sericin was not sufficiently removed and not sufficiently refined.

  When scouring using an acid scouring solution having an initial pH of less than 1 (Comparative Examples 10 to 12), the reduction rate was 25% or more, and the scouring silk was sufficiently soft, but the elongation was It was less than 11% and the strength was less than 150 g. When scouring using an acid scouring solution having an initial pH of less than 1, sericin was removed, but it was found that fibroin was severely damaged.

  In Comparative Examples 3, 4, 8 and 9, it was clear that the reduction rate was lower than 25% and the texture of the obtained scoured silk was not good, so that it had sufficient elongation and strength. However, since it was apparent that sericin was not completely removed without damaging the silk fibers, the elongation and strength were not measured.

  Next, the case where raw silk was finally kneaded with an acid scouring solution and then finished with an alkaline scouring solution was examined.

(Example 15)
As shown in Table 3, as the main kneading, an acid scouring solution containing 4% OWF of phosphoric acid was used so that the bath ratio was 1:20, and raw silk (21/3 pieces) was boiled and scoured for 40 minutes. Then, as finishing kneading, an alkaline scouring solution containing 2% OWF of soap and 1% OWF of soda ash (sodium carbonate) was used so that the bath ratio was 1:20. Simmered for a minute. Thereafter, it was washed with hot water and further washed with hot water. The initial pH of the acid scouring solution for final kneading was 1.8, and the initial pH of the alkaline scouring solution for finishing kneading was 9.6.

[Evaluation methods]
For Example 15, the reduction rate, elongation, strength and texture were measured as described above, and the results are shown in Table 4.

  As can be seen from Table 4, after scouring with an acid scouring solution in the main kneading and then scouring with an alkaline scouring solution in the final kneading (Example 15), after the kneading, the reduction rate Was less than 25% and was not sufficiently scoured, but after finishing kneading, the reduction rate was 25% or more, and the scoured silk became sufficiently soft. From this, it was found that sericin was sufficiently removed. Further, the elongation and strength were sufficiently high, and the scoured silk generated silkiness and had a silk-specific luster. This showed that fibroin was not significantly damaged. From the above, it was found that sericin could be completely removed without over-scouring and damaging the silk fibers.

・ Study on scouring raw fabrics First, we studied the scouring method of flat koji used as a back fabric.

(Example 16)
As shown in Table 5, an acid scouring solution containing 2 g / L of phosphoric acid was used as a rough kneading so that the bath ratio was 1:40, and the lining dough (flat rice cake) was boiled and scoured for 60 minutes. As the main kneading, an alkaline scouring solution containing 1 g / L soap, 2 g / L soda ash, and 1 g / L metal ion sequestering agent (sodium tripolyphosphate) was used so that the bath ratio was 1:40. Then, the above-described rough flat rice cake was boiled and scoured for 50 minutes. Further, hydrosulfite (sodium dithionite) as a reducing bleach was added to the scouring solution so as to have a concentration of 1 g / L, followed by boiling and scouring for 10 minutes. Then, hot water was washed. The initial pH of the rough acid kneading solution was 1.5, and the initial pH of the main kneading alkali scouring solution was 10.8.

(Example 17)
Similar to Example 16 except that 1 g / L of sulfuric acid is included instead of 2 g / L of phosphoric acid. The initial pH of the rough acid scouring solution was 1.1.

(Example 18)
Similar to Example 16, except that 1 g / L of nitric acid is included instead of 2 g / L of phosphoric acid. The initial pH of the rough acid scouring solution was 1.4.

Example 19
Similar to Example 16 except that 1 g / L hydrochloric acid is included instead of 2 g / L phosphoric acid. The initial pH of the rough acid scouring solution was 1.6.

(Comparative Example 13)
As shown in Table 5, an alkaline scouring solution containing 1 g / L of soap, 2 g / L of soda ash, and 1 g / L of sodium tripolyphosphate was used as roughing so that the bath ratio was 1:40. The dough (flat rice cake) was boiled and scoured for 60 minutes. Then, as the main kneading, an alkaline scouring solution containing 2 g / L of soap, 1 g / L of soda ash, and 1 g / L of sodium tripolyphosphate is used so that the bath ratio is 1:40, and the above rough kneading is performed. The flat rice cake was boiled and scoured for 50 minutes. Further, hydrosulfite was added to the scouring solution so as to be 1 g / L, and further scoured by boiling for 10 minutes. Then, hot water was washed. The initial pH of the rough alkaline scouring solution was 10.8, and the initial pH of the final alkaline scouring solution was 10.5.

[Evaluation methods]
For Examples 16 to 19 and Comparative Example 13, the reduction rate was measured as described above, the texture was evaluated as follows, and the results are shown in Table 6.

(Texture)
The scoured material after scouring was touched and evaluated as follows.
A: Very soft and supple compared to the material to be scoured before scouring.
○: Compared to the material to be scoured before scouring, it is soft, but has a little core and a little hardness.
(Triangle | delta): It is soft compared with the to-be-scoured material before scouring, but there is a core and hardness remains.
X: Compared with the material to be scoured before scouring, it is not so soft.

  As can be seen from Table 6, when scouring with an acid scouring solution by rough scouring and then scouring with an alkaline scouring solution by main kneading (Examples 16 to 19), after scouring, The reduction rate was lower than 25% and was not sufficiently scoured, but after this kneading, the reduction rate was 25% or more, and the scoured silk was sufficiently soft and supple. From this, it was found that sericin could be completely removed without over-scouring and damaging the silk fibers.

  After scouring with an alkaline scouring solution by rough scouring and then scouring again with an alkaline scouring solution by main kneading (Comparative Example 13), Examples 16 to 19 have similar results. It was. Comparative Example 13 is a case where a method that has been preferably used conventionally as a kneading method is used, and Examples 16 to 19 are sufficiently practical as a scouring method. Furthermore, Examples 16 to 19 are preferable because the amount of alkaline scouring liquid containing soap that causes environmental pollution is small.

In addition, after scouring using an acid scouring solution by rough scouring, scouring using an alkaline scouring solution by main kneading (Examples 16 to 19), the scouring waste liquid after rough scouring is overnight, Upon standing, it gelled. From this, when scouring using an acid refinement solution, sericin can be removed without much decomposition, and high molecular weight sericin preferably used in cosmetics and the like can be recovered.
Next, a method for scouring chirimen (pattern design) was examined.

(Example 20)
As shown in Table 7, a scouring solution containing 2 g / L of phosphoric acid was used as a rough kneading so that the bath ratio was 1:40, and the crepe was boiled and scoured for 60 minutes. Then, as the main kneading, an alkaline scouring solution containing 2 g / L of soap, 2 g / L of soda ash, and 1 g / L of sodium tripolyphosphate is used so that the bath ratio is 1:40, and the above rough kneading is performed. The flat rice cake was boiled and scoured for 100 minutes. Further, hydrosulfite, which is a reducing bleach, was added to the scouring solution so as to be 1 g / L, and further scoured by boiling for 20 minutes. Then, hot water was washed. The initial pH of the rough acid kneading solution was 1.5, and the initial pH of the main kneading alkali scouring solution was 10.8.

(Example 21)
Similar to Example 20, except that 1 g / L sulfuric acid is included instead of 2 g / L phosphoric acid. The initial pH of the rough acid scouring solution was 1.1.

(Example 22)
Similar to Example 20, except that 1 g / L of nitric acid is included instead of 2 g / L of phosphoric acid. The initial pH of the rough acid scouring solution was 1.4.

(Example 23)
Similar to Example 20 except that 1 g / L hydrochloric acid is included instead of 2 g / L phosphoric acid. The initial pH of the rough acid scouring solution was 1.6.

(Comparative Example 14)
As shown in Table 7, an alkaline scouring solution containing 2 g / L of soap, 2 g / L of soda ash and 1 g / L of sodium tripolyphosphate was used as roughing so that the bath ratio was 1:40. Chirimen was boiled and scoured for 60 minutes. Then, as the main kneading, an alkaline scouring solution containing 2 g / L of soap, 2 g / L of soda ash, and 1 g / L of sodium tripolyphosphate is used so that the bath ratio is 1:40, and the above rough kneading is performed. Sachiri noodles were boiled and scoured for 100 minutes. Furthermore, hydrosulfite was added to the scouring solution so as to be 1 g / L, and further scoured by boiling for 20 minutes. Then, hot water was washed. The initial pH of the rough alkaline scouring solution was 10.8, and the initial pH of the basic scouring alkaline solution was 10.8.

(Comparative Example 15)
Similar to Example 20 except that 4 g / L of citric acid is included instead of 2 g / L of phosphoric acid. The initial pH of the rough acid scouring solution was 2.3.

(Comparative Example 16)
Similar to Example 20, except that 1 g / L of lactic acid is included instead of 2 g / L of phosphoric acid. The initial pH of the rough acid scouring solution was 2.3.

(Comparative Example 17)
Similar to Example 20, except that 4 g / L malic acid is included instead of 2 g / L phosphoric acid. The initial pH of the rough acid scouring solution was 2.3.

(Comparative Example 18)
Similar to Example 20, except that 4 g / L tartaric acid is included instead of 2 g / L phosphoric acid. The initial pH of the rough acid scouring solution was 2.3.

[Evaluation methods]
About Examples 20-23 and Comparative Examples 14-18, the reduction rate and the texture were measured as described above, and the results are shown in Table 8.

  As can be seen from Table 8, when scouring with an acid scouring solution by rough scouring and then scouring with an alkaline scouring solution by main kneading (Examples 20 to 23), after scouring, The reduction rate was lower than 25% and was not sufficiently scoured, but after this kneading, the reduction rate was 25% or more, and the scoured silk was sufficiently soft and supple. From this, it was found that sericin could be completely removed without over-scouring and damaging the silk fibers.

  After scouring with an alkaline scouring solution by rough scouring and then scouring again with an alkaline scouring solution by main kneading (Comparative Example 14), Examples 20 to 23 have similar results. It was. The comparative example 14 is a case where the method conventionally used preferably as a cloth kneading method is used, and Examples 20-23 are fully practical as a scouring method. Furthermore, Examples 20 to 23 are preferable because the amount of the alkaline scouring liquid containing soap that causes environmental pollution is small.

  In addition, after scouring with an acid scouring solution by rough scouring and then scouring with an alkaline scouring solution by main kneading (Examples 20 to 23), the scouring waste liquid after roughing is overnight, Upon standing, it gelled. From this, when scouring using an acid refinement solution, sericin can be removed without much decomposition, and high molecular weight sericin preferably used in cosmetics and the like can be recovered.

When rough scouring and using an acid scouring solution containing only an organic acid and the initial pH of the acid scouring solution being 2 or more (Comparative Examples 15 to 18), after roughing, the reduction rate is lower than 25%. Even after the main kneading, the reduction rate was lower than 25%, and the scoured silk was not sufficiently soft. From this, it was found that sericin cannot be sufficiently removed by main kneading unless sericin is removed to some extent by rough kneading.
Finally, the method of scouring with the wool was studied.

(Example 24)
As shown in Table 9, an acid scouring solution containing 1 g / L of phosphoric acid was used so that the bath ratio was 1:40, and the silk / wool union was scoured by boiling for 50 minutes. Thereafter, degloline, which is a reducing bleach, was added to the acid scouring solution so as to have a concentration of 1 g / L, followed by boiling for 10 minutes. Then, hot water was washed. The initial pH of the acid scouring solution was 1.6.

(Example 25)
Example 24 is the same as Example 24 except that 0.5 g / L of phosphoric acid and 0.5 g / L of sulfuric acid are contained instead of 1 g / L of phosphoric acid. The initial pH of the acid scouring solution was 1.4.

[Evaluation methods]
For Examples 24 and 25, the reduction rate and texture were measured as described above, and the results are shown in Table 10.

  As can be seen from Table 10, when a scouring solution containing an inorganic acid and having an initial pH of 1.0 or more and less than 2.0 was scoured with a wool having low base resistance (Examples 24 and 25). ), The reduction rate was 20% or more even when wool was included, and it became sufficiently soft. From this, it was found that sericin was sufficiently removed. Moreover, even if the wool having low base resistance is included, since the scouring is performed using the acid scouring solution, the union was not greatly damaged.

  As described above, by scouring using a scouring solution containing an inorganic acid and having an initial pH of 1.0 or more and less than 2.0, the scoured product is not greatly damaged regardless of the scoured product. Sericin can be completely removed.

It is a figure which shows the silk fiber (raw silk) 10 before scouring. It is a figure which shows the scoured silk after scouring silk fiber. It is a figure which shows the process of the scouring method. It is a figure explaining the method to measure the elongation of the fiber 20. FIG.

Explanation of symbols

10 Silk fiber (raw silk)
11 Fibroin 12 Sericin 20 Fiber 21 Jig

Claims (6)

A scouring method for scouring raw silk, twisted twisted raw silk or raw fabric,
A scouring method comprising scouring using an acidic scouring liquid containing an inorganic acid and having an initial pH of 1 or more and less than 2.   The scouring method according to claim 1, wherein the scouring solution is scoured at a temperature of 90 ° C or higher.   The scouring method according to claim 1 or 2, wherein the acidic scouring liquid contains an organic acid.   The scouring method according to claim 1, wherein the acidic scouring liquid contains a surfactant.   5. After scouring using the acidic scouring solution, scouring at 90 ° C. or higher using a basic scouring solution having an initial pH of 9 or more and 11 or less. 6. Scouring method.   The scouring method according to claim 5, wherein the basic scouring liquid contains a surfactant.

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