JP2003192934A - Natural dye for indigo dyeing using raw leaves of indigo plant as raw material and method for production of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To produce a natural dye for indigo dyeing by using raw leaves of an indigo plant in a short time and at a low cost without emitting bad odor. <P>SOLUTION: The natural dye useful for indigo dyeing is produced by freezing raw leaves of indigo plant and by thawing the frozen leaves, during its melting, indican contained in the leaves changes to indoxyl owing to action of an enzyme and water contained in the leaves, further it reacts with oxygen in air then forms indigo, therefore it is prepared after drying the leaves by pulverizing them into a powder. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an indigo dye obtained by freezing and thawing fresh leaves of indigo plants such as Tateai and Ryukyu indigo, followed by drying and powdering. Is a method for producing a natural dye. 2. Description of the Related Art Indigo plants, such as the indigo plant, are used to dry the harvested leaves, give them water, lay them down, ferment them repeatedly by adding water and turning them back, and call them Sukumo. This process requires extensive facility equipment, advanced technology and a period of about 100 days, and thus the dye is expensive. In addition, since it goes through a fermentation process, it emits a unique odor and may be disliked by users. [0003] The indigo dye called Sukumo, which is manufactured by conventional techniques, requires extensive facility equipment, advanced technology, and a period of about 100 days.
Therefore, the dye is expensive. Also,
Due to the fermentation process, it emits a unique odor and may be hated by users. For this reason, we decided to use natural leaves of indigo plants to produce natural dyes of indigo dyeing at low cost for a short period of time and without odor. [0004] In order to solve the above-mentioned problems, only leaves are collected from the harvested indigo plants and completely frozen in a freezer or the like while fresh. When the frozen leaves are thawed, the indicans contained in the leaves are hydrolyzed by the action of enzymes and water in the leaves to indoxyl during the thawing process because the leaves are damaged by freezing. Indoxyl combines with oxygen in the air to form indigo. In this step, it is preferable to spread the leaves in a plane and repeat the stirring so that the whole is in contact with air to promote the oxidation. The leaves, on which the indigo has been formed in this way, are dried and then powdered by any method to complete the indigo-dyed natural dye. [0005] From the harvested indigo plants, only leaves are collected and completely frozen in a freezer or the like while fresh. When the frozen leaves are thawed, the indicans contained in the leaves are hydrolyzed by the action of enzymes and water in the leaves to indoxyl during the thawing process because the leaves are damaged by freezing. Indoxyl combines with oxygen in the air to form indigo. In this step, it is preferable to spread the leaves in a plane and repeat the stirring so that the whole is in contact with air to promote the oxidation. The leaves, on which the indigo has been formed in this way, are dried and then powdered by any method to complete the indigo-dyed natural dye. The time required from the collection of the leaves to the completion of the dye is about 5 days, and the completed dye emits a faint scent of dried indigo leaves. What is an example of the indigo dyeing method using this dye? About 2.5 kg of the dye is added to 40 liters of water in which 2.5 g of caustic soda is dissolved per liter, and the mixture is stirred. Then, about 200 g of sodium hydrosulfite is added and stirred. After standing for several hours, the indigo is reduced to Leucoin digo to complete the dyeing liquor. Instead of caustic soda, about 8 times the amount of soda ash may be used. A cloth squeezed uniformly with water is squeezed into a dye solution, taken out after about 3 minutes, squeezed evenly, and exposed to air. Leucoin digo combines with oxygen in the air to become indigo and develops a blue color. I do. Repeat the above, when the desired color is obtained, wash with water and dry. In addition,
A darker color can be obtained by increasing the amount of dye in the liquor. According to this embodiment, an indigo-dyeing natural dye which does not emit odor can be produced in a short period of time at low cost using fresh leaves of an indigo plant. As described above, according to the present invention, a natural dye of indigo dyeing which does not emit odor is produced in a short period of time and at low cost using fresh leaves of an indigo plant. be able to.

Claims (1)

Claims: 1. A method for producing an indigo-dyeing natural dye obtained by freezing and thawing fresh leaves of an indigo plant and then drying and powdering the leaves.