JPH11152687A - Treatment for improving light resistance of bluish violet pigment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the light resistance of a bluish violet pigment such as violacein and deoxyviolacein. SOLUTION: This method for treating for improving the light resistance of a blish violet pigment is to treat a fiber or a fibrous product dyed with a blue and violet pigment such as a violacein or a deoxyviolacein with an aqueous solution of thiourea. The blish violet pigment is produced from a bacterium, especially by Janthinobacterium lividum.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing method for improving the light fastness of a blue-violet dye, in particular, to violacein (Violasein).
acein), a method of post-treating fibers and textiles dyed with deoxyviolacein in an aqueous thiourea solution.

[0002]

2. Description of the Related Art As dyes for clothing, chemical dyes have become mainstream with the progress of chemical technology. On the other hand, natural dyes such as plant dyes and animal dyes are still popular with natural dyes because they provide natural deep-tasting intermediate colors that cannot be obtained with chemical dyes. Among them, blue-violet natural pigments have been more prized and respected as noble dyes not only because of their beauty but also because of the difficulty in obtaining dyes. As a natural purple pigment, shell purple extracted from a persimmon shell which has a very small amount of pigment in the body is famous. However, shellfish purple is extremely expensive (only one gram of dye can be obtained from hundreds of persimmons) (market price 1).
(About 20,000 yen per gram), which is difficult to mass-produce.

[0003] Recently, the bacterium Janthinobacterium libudam ( Janthinobacterium lidam) has been produced from blue-contaminated cocoons and silk thread.
vidum ) (Akira Shirata: Blue-violet pigment, B from microorganisms)
RAIN Techno News, 60, 14-16, 1997), found that the violet pigment produced by this bacterium dyes not only natural fibers such as silk, wool and cotton, but also chemical fibers such as nylon and acetate. (See Japanese Patent Application No. 8-268452). As a result of identification of this dye, it was found that the dyes were violacein (molecular weight: 343) and deoxyviolacein (molecular weight: 327). Since this dye can be obtained in large quantities at low cost by culturing bacteria in addition to chemical synthesis, it is expected to be used as a natural purple dye. However, when applied to fibers, the most problematic was instability to light.

The dyeing fastness of fibers and textile products dyed with the methanol extract of the blue-violet dye is as fast as 1 to wash.
The fastness to -2, boiling water, acidic sweat, alkaline sweat and friction was determined to be 2 or more and about 3-4. Therefore, these water-related dyeing fastnesses have no practical problem at all, while the dyeing fastness to sunlight is 1st class or less (class 1 is the lowest in JIS standards, but as a result of the test,
And the blue-violet color faded immediately upon exposure to sunlight, making it unusable for practical use.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a treatment method for improving the light fastness of fibers and fiber products dyed with blue-violet dyes violacein and deoxyviolacein.

[0006]

Means for Solving the Problems The present inventors diligently studied a treatment method for improving the light fastness of a fiber or a textile product dyed with a blue-violet dye, and the dyed product was post-treated in an aqueous thiourea solution. Then, it was found that the photobleaching behavior was remarkably suppressed and the light resistance was improved, and the present invention was completed.

The method for improving light resistance of the present invention comprises treating a fiber or a fiber product dyed with a blue-violet dye, violacein, deoxyviolacein, or a mixture of both, with an aqueous thiourea solution.

[0008] The blue-violet pigment is preferably produced from a strain of the bacterium Jansinobacterium lividum, but is not limited to this. Other bacteria (for example, Chromobacterium violaceum) may be used.
ium violaceum )) or chemically synthesized. This Jansinobacterium lividum (S9601 strain) has been deposited with the Institute of Biotechnology, National Institute of Advanced Industrial Science and Technology under the deposit number FERM P-15894, and is available from the research institute. In the literature.

It is preferable that the thiourea aqueous solution is an aqueous solution having a concentration ranging from a 5% thiourea aqueous solution to a thiourea saturated aqueous solution. If it is less than 5%, the effect of suppressing fading of the dyed product is low.

[0010]

Embodiments of the present invention will be described below.

In the present invention, the dyed fibers and textile products of interest are obtained according to a bacterium dyeing method and an organic solvent dyeing method (the above-mentioned Japanese Patent Application No. 8-268452).
No.) is desirable. Bacterial solution staining is, for example, suspending the cells of the bacterium Jansinobacterium lividum in water or a liquid medium such as a potato semi-synthetic medium or a cocoon broth medium, and fibers and the like in the suspension at a predetermined temperature. ,
This is a method of dyeing by immersing for a predetermined time.
In addition, the organic solvent staining method is, for example, a method of converting a dye-containing component from the cells of the above-mentioned bacteria into an organic solvent (for example, tetrahydrofuran, methanol, ethanol, acetone, ethyl acetate,
Diethyl ether, butanol, etc.), and in this extract, or in a blue-violet pigment isolated from this extract or a chemically synthesized blue-violet pigment (violacein, deoxyviolacein), an organic solvent (for example, methanol,
In this method, fibers and the like are immersed in a liquid dissolved and dispersed in ethanol, acetone, ethyl acetate and the like at a predetermined temperature for a predetermined time to perform dyeing. Upon such dyeing, by adjusting the dye concentration in the dyeing solution, the immersion time, etc., for example, light blue to mauve, blue-violet, and navy blue can be separately dyed, and the dyed color referred to in the present invention includes these. .

By treating the fiber dyed as described above with an aqueous thiourea solution, the light fastness is improved.
The effect of suppressing photobleaching is improved as the concentration of thiourea is increased. When treated with a 5% thiourea aqueous solution, the fastness to sunlight is generally second class.
It turned out to be about class. In addition, even if this treatment is applied to a dyed material, the problem that the hue of the dyed material changes does not occur.

The method for improving light resistance according to the present invention is preferably that a fiber or a fiber product dyed with a methanol solution of a blue-violet dye is immersed in an aqueous thiourea solution at room temperature for 1 to 5 minutes, then dehydrated lightly and air-dried. It is done.

Since the effect of suppressing photobleaching is manifested by the attachment of thiourea to the dyed material, the effect is likely to be lost by washing with water or washing. However, since the fading of the blue-violet dye can be suppressed again by a treatment method of washing with water and washing after the wearing of the textile product, and then treating again with an aqueous thiourea solution, it is practical if the treatment is performed every time washing is performed. In general, it is possible to suppress discoloration over a long period of time.

The fibers which can be improved in light resistance according to the present invention are all fibers which can be dyed with the blue-violet dye, that is, natural fibers such as silk, wool and cotton, and chemical fibers such as nylon and acetate. It is a method that can be widely applied to these fibers and fiber products.

Among the blue-violet pigments used for dyeing the dyed fibers and textile products of the present invention,
The microorganism-derived pigment is obtained as follows. For example,
Screening of waste cocoons, contaminated silk, etc. using a potato semi-synthetic medium, etc., and isolation of the blue-violet bacterium Jansinobacterium lividam (FERM P-15894),
This isolated strain is cultured using a method similar to that for known aerobic bacteria. During the cultivation, a potato semi-synthetic medium or the like is used and the temperature is maintained at 5 to 30 ° C. and the pH is maintained at 6.0 to 8.0. From the cells thus obtained, a blue-violet pigment is extracted using the organic solvent as described above. Removal of the organic solvent gives violacein and deoxyviolacein. Extracted blue-violet dye, the usual isolation method,
For example, if isolated by silica gel chromatography or reversed-phase high-performance liquid chromatography, violacein and deoxyviolacein can be obtained.

[0017]

Hereinafter, the present invention will be described with reference to specific examples and comparative examples (hereinafter, referred to as controls). These examples are merely illustrative and do not limit the invention in any way.

(Example 1) A bacterium (FERMP-1589) exhibiting a blue-purple color from greenish brown colored waste thread using various media.
4) After separation of the (decoctions 1L, Ca (NO ₃ potato tubers 300 g) of bacteria isolated potato semisynthetic agar ₂ 4H ₂
O 0.5 g, Na ₂ HPO ₄ 12H ₂ O 2 g, peptone 5 g, sucrose 15 g, agar 15 g) and King B medium (peptone 20 g, K ₂ HPO ₄ 1.5 g, MgSO ₄ 7H ₂ O 1.5 g, glycerin 10 mL) , Agar (15 g, distilled water 1 L), and cultured for 1 week (25 ° C.). The dark blue-violet cells were scraped into a small beaker, and the blue-violet pigment was extracted with methanol. The extracted pigment was fractionated and isolated by silica gel chromatography (hexane: tetrahydrofuran: acetone = 4: 2: 1) and reversed-phase high-performance liquid chromatography (70% methanol).
The molecular weight of the obtained two components was determined by FAB-MS (violacein (molecular weight: 343), deoxyviolacein (molecular weight: 327)), ¹ H, ¹³ C NMR, I
It was identified as violacein and deoxyviolacein by R and UV spectra.

In a methanol solution of a blue-violet pigment derived from microorganisms (a mixture of violacein and deoxyviolacein) extracted as described above, a silk fabric (a white cloth attached for dyeing fastness, equivalent to 14 double-faced flat wings) was placed for 2 days. Immersion (bath ratio 1:
(About 100, normal temperature) and stained. In addition, the color depth of the dyed silk fabric is determined by the standard dyeing density table No. 3 (Jls L 0
810) (bright, color chart No. 9,
x = 0.2538, y = 0.2402, Y = 19.8
9) luminous color density (x = 0.2539, y =
0.2291, Y = 19.17).

0.2%, 2.0%, 5.0
After immersion treatment (bath ratio 1: about 300, normal temperature) in a thiourea (TU) aqueous solution having a concentration of 5% for 5 minutes, the solution was lightly drained and air-dried. The thiourea-treated fabric and the untreated fabric were exposed to sunlight outdoors (49 hours in total) for seven days on a fine day (August 18-26, 1997). The degree of photobleaching was measured using a self-recording spectrophotometer (Shimadzu UV-3100 / 3100S type).
The Lab value was determined by measuring the reflectance spectrum in the wavelength range of 0 to 800 nm, and evaluated by the chromaticity index b value (the smaller the b value, the deeper the blue-violet color). The results obtained are shown in FIG.

As is clear from FIG. 1, the thiourea-treated fabric has a lower fading speed and light resistance as compared with the control (untreated fabric). It was also found that the effect of suppressing fading increases as the concentration of thiourea increases.

When the same treatment as above was performed using the violacein and deoxyviolacein isolated as described above, the thiourea-treated fabric was similarly compared with the control (untreated fabric). The fading speed is slow, light resistance is high, and the fading inhibiting effect increases as the concentration of thiourea increases.

Example 2 A dyed product of the blue-violet dye mixture obtained according to Example 1 was treated with a 5% aqueous solution of thiourea and a saturated aqueous solution of thiourea, and then subjected to a test method for dyeing fastness to sunlight (Jls L 0841). According to the direct sunlight method, the fastness to sunlight was calculated according to the method (exposure to sunlight, August 1997
(Sunny day of the month 25-28).

While the untreated woven fabric was class 1 or lower (JIS class 1 was the lowest, but the test showed that it was class 1 or lower), the dyed product treated with a thiourea saturated aqueous solution The dyed product treated with a 5% aqueous solution of thiourea was evaluated as tertiary, and the dyed product was evaluated as tertiary. Further, the treatment with the aqueous thiourea aqueous solution did not cause a color change in the blue-violet dyed product, and did not adversely affect the texture of the fabric. Similar results are obtained for each of the isolated dyes.

The saturated aqueous solution of thiourea used in the present embodiment is prepared by dissolving thiourea (Wako Pure Chemicals, special grade reagent) in hot water at 70 to 80 ° C. and allowing it to cool naturally to obtain a supersaturated aqueous solution of thiourea. The supernatant was repeatedly filtered twice at normal temperature with a filter paper (Toyo Rossi No. 3).

(Embodiment 3) Embodiment 1 is performed by the following method.
The dyed product of the blue-violet dye mixture obtained according to the above was repeatedly treated with a saturated aqueous thiourea solution 1, 3, 5 times.

(L) After immersion in a thiourea saturated aqueous solution at room temperature for 3 minutes, dehydration and air drying.

(2) Hot water (40 ° C., using ion-exchanged water)
Wash with water for 2 minutes.

(3) After immersion in a thiourea saturated aqueous solution at normal temperature for 1 minute, dehydration and air drying.

Thereafter, the above steps (2) and (3) were repeated to obtain samples for fading measurement (sun exposure, 1
Fine weather time on September 1-5, 997 (30 hours in total).

The degree of fading of each sample was measured by the method of Example 1, and the results are shown in Table 1.

[0032]

[Table 1]

As is clear from Table 1, when the post-treatment with the thiourea aqueous solution is repeated, the blue-violet light fading is suppressed and the light resistance tends to be more improved as compared with the control. Similar results are obtained for each of the isolated dyes.

Example 4 Regarding the effect of the thiourea treatment, the dyed product of the blue-violet dye mixture obtained according to Example 1 was washed (washed), treated with a thiourea saturated aqueous solution, and exposed to sunlight 2 as follows. With the combination of time as one unit,
The procedure was repeated up to 5 units. For each unit, the degree of fading was evaluated by visual observation, the reflectance spectrum in the visible light wavelength region was measured to determine the Lab value, and the chromaticity index b value was used.

(L) After immersion in a thiourea saturated aqueous solution at room temperature for 3 minutes, dehydration and air drying.

(2) Exposure to sunlight for 3 hours.

(3) Neugen HC (Daiichi Kogyo Seiyaku)
After washing with a 0.2% aqueous solution at 40 ° C for 3 minutes, warm water (4
(0 ° C, using ion-exchanged water) 5 times,
Air drying. The control (untreated with thiourea) was washed similarly.

(4) After immersion in a thiourea saturated aqueous solution at room temperature for 1 minute, dehydration and air drying.

Thereafter, the treatments (2)-(4) were repeated to obtain samples for fading measurement (sun exposure, 19
(Sunny day, September 10-17, 1997).

The above method is called a treatment method, and Table 2 shows the effect of suppressing the photobleaching by this treatment method.

[0041]

[Table 2]

As is evident from Table 2, in the control (untreated fabric) not subjected to the thiourea aqueous solution treatment, even one unit (three hours of exposure to sunlight) showed a blue-violet fading that could be discerned by the naked eye. When the exposure was started and the sunlight exposure was further repeated, the change in the b value was extremely large, and the photobleaching proceeded as the exposure time increased. On the other hand, the thiourea-treated fabric has a small change in the b value even by repeating 5 units,
It is observed that the blue-violet light fade is small. Similar results are obtained for each of the isolated dyes.

[0043]

EFFECT OF THE INVENTION In the fiber and textile products dyed with the blue-violet dyes violacein and deoxyviolacein, for example, the blue-violet dye produced by the bacterium Jansinobacterium lividum, the most serious problem is that it is very fading due to sunlight. Was solved by the present invention.
As a result, practical problems have been eliminated even when violacein and deoxyviolacein are used as dyes for not only natural fibers such as silk, wool and cotton but also chemical fibers such as nylon and acetate. For this reason, bacteria, for example, the blue-violet pigments violacein and deoxyviolacein produced by Jacinobacterium libidum, are rare, expensive, and difficult to mass-produce, and are difficult to mass-produce. And it became possible to use it cheaply.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the sun exposure time and the fading of a blue-violet dyed product.

Continuation of the front page (51) Int.Cl. ⁶ Identification code FI C12R 1:01) (72) Inventor Takataka Tsukamoto 1-2 Owashi, Tsukuba, Ibaraki Pref.

Claims (3)

[Claims] 1. A method for improving light resistance, comprising treating a fiber or a fiber product dyed with a blue-violet pigment, violacein, deoxyviolacein, or a mixture of both, with an aqueous thiourea solution. 2. The method for improving light resistance according to claim 1, wherein the blue-violet pigment is produced from the bacterium Jansinobacterium lividam. 3. The method for improving light resistance according to claim 1, wherein the aqueous thiourea solution is an aqueous solution within a concentration range from a 5% aqueous thiourea solution to a saturated aqueous thiourea solution.