JPH0759489B2 - Permanent Wave 1st Agent - Google Patents

Description

The present invention relates to a permanent wave first agent, and more specifically to a permanent wave first agent containing thioglycolic acid or a salt thereof from which odorous components have been removed.

[Conventional technology]

Conventionally, the wave treatment by the permanent wave method is
First, the disperse bond between the keratin molecules of the hair is reductively cleaved with a permanent wave first agent (hereinafter referred to as “first agent”) that is a reducing agent solution, and then a permanent wave second agent (hereinafter referred to as “second agent” that is an oxidizing agent solution. Abbreviated as "agent")
The method of re-forming disulphide bond by oxidation with is widely used. Thioglycolic acid or a salt thereof or cysteine is used as the reducing agent of the first agent, but when the two are compared, cysteine is inferior in the wave forming property and durability of the hair, which is the basic performance of the permanent wave, It is only used on damaged hair, and generally thioglycolic acid or its salts are widely used.

However, thioglycolic acid or a salt thereof generally has a strong malodor due to malodorous trace impurities contained therein, and a permanent wave agent containing such a thioglycolic acid or a salt thereof is a permanent wave practitioner ( There is a drawback in that it causes discomfort to both the beautician or barber and the permanent recipient (customer).

Therefore, in order to eliminate this drawback, distillation, extraction, steaming or the like is generally proposed as a method for removing the malodorous component mixed in the reducing agent thioglycolic acid or its salt. Of these, the method of distilling thioglycolic acid is obtained as a distillate that does not have an offensive odor with the impurities in question removed, but since a large amount of the dehydrated condensate of thioglycolic acid remains as a distillation residue, It is not industrial because of low yield and high cost. Further, the method by extraction is to remove impurities causing an offensive odor with a specific solvent as described in JP-B-61-16387, but in this method, the solvent used is thioglycolic acid or a salt thereof. It is not preferable because it mixes with the inside of the syrup and causes a new odor, and a step of completely removing the odor is required again.

[Problems to be solved by the invention]

Compared to the above two methods, the steaming method of introducing water vapor is the simplest and has a large deodorizing effect, but the steaming performed under normal pressure is effective in removing malodorous impurities from thioglycolic acid or its salt. Since the temperature is low and the steaming is required for a long time, there is a drawback that the liquid temperature rises and malodorous impurities are generated during the steaming operation.

[Means for solving problems]

The present inventors, as a result of various studies on a method for advantageously removing malodorous impurities from thioglycolic acid or a salt thereof,
When the steaming method of introducing water vapor is carried out under the conditions described below, the drawbacks of the conventional method can be eliminated, and thioglycolic acid or a salt thereof having almost no malodor can be obtained, and if the thioglycolic acid or its salt is used, an unpleasant odor can be obtained. No first
The inventors have found that an agent can be obtained and completed the present invention.

That is, the present invention provides thioglycolic acid or an aqueous solution thereof or an aqueous solution of thioglycolic acid salt at a temperature of 30 to 80.
The present invention provides a permanent wave first agent, which contains deodorized thioglycolic acid or a salt thereof obtained by steam distillation at a temperature of 300 ° C. and a pressure of 300 Torr.

In the present invention, the liquid temperature and pressure at the time of introducing water vapor into thioglycolic acid or its salt are important and determine the odor after deodorization, and the liquid temperature is from 30 ° C to 80 ° C as described above.
It is necessary to keep in the range of ° C. If the temperature exceeds 80 ° C, thioglycolic acid or its salt will deteriorate in odor due to heat,
If the temperature is lower than 30 ° C, the efficiency of removing malodorous impurities is significantly reduced, which is not preferable. Moreover, the pressure also needs to be 300 Torr or less, and if it exceeds 300 Torr, the efficiency of removing malodorous impurities becomes low, and it becomes difficult to remove malodor.

When practicing the present invention, since thioglycolic acid is normally a liquid, water vapor can be introduced as it is or in the form of an aqueous solution. On the other hand, since thioglycollate is usually solid in the normal state, it is preferable to introduce water vapor in the form of an aqueous solution. When thioglycolic acid or a salt thereof is used in the form of an aqueous solution, the concentration of the aqueous solution can be arbitrarily selected, but generally 20% as an acid or a salt is used.
It is preferably set to 80%.

For the introduction of water vapor, the usual equipment used for that purpose can be used. In many cases, deodorization of thioglycolic acid or a salt thereof by introducing water vapor can achieve the purpose by one deodorization operation, but the deodorization operation may be repeated a plurality of times as necessary.
The present invention can also be achieved by a continuous method of taking out deodorized substances while sending undeodorized substances.

The introduction rate of water vapor is not particularly limited, but it is preferably 1 to 100% (vs. charged amount) / Hr with respect to the charged amount of thioglycolic acid or its salt to be deodorized. Furthermore, the objective can be achieved when the total amount of steam introduced until the end of deodorization is 100% (based on the charged amount), and even if steam is introduced in excess of 100%, no further effect can be expected.

The above deodorization methods generally apply to thioglycolic acid and ammonium, monoethanolamine, diethanolamine and triethanolamine salts of thioglycolic acid. That is, it does not matter whether the deodorizing object is an acidic liquid or an alkaline liquid in which an excess of amines coexists.

〔The invention's effect〕

The deodorized thioglycolic acid obtained by the above method does not have a bad odor as compared with the one deodorized by the conventional method, and in addition, the odor does not return. Therefore, this deodorized thioglycolic acid does not produce a bad odor even when it is stored for a long period of time, and when the thioglycolic acid is blended with a permanent wave agent, it does not affect both permanent wave practitioners and recipients. It does not cause any discomfort.

〔Example〕

 Next, the present invention will be described in more detail with reference to examples.

Production Example 1 A thermometer, a glass tube for introducing steam, and a Liebig cooling tube were attached to the four-necked flask of 1, and 600 g of ammonium thioglycolate aqueous solution (50% as thioglycolic acid) was charged therein, and the liquid temperature was 70 ° C. Heated to. Then 200T
The pressure was reduced to orr and the introduction of water vapor was started. Temperature 69-74
The temperature was maintained at 180 ° C to 200 Torr and the steam was introduced at a rate of 60 g / Hr. After 2 hours (total water vapor content 20% (vs. the amount charged)), almost no odor was felt, and deodorized thioglycolic acid was obtained.

Production Example 2 When the same operation as in Example 1 was performed with the liquid temperature at the time of introducing steam being 41 to 51 ° C. and the pressure being 50 to 70 Torr, a bad odor was obtained after 3 hours (total steam amount 30% (vs. the charged amount)). Almost no sensation was obtained and deodorized thioglycolic acid was obtained.

Comparative Production Examples 1 and 2 The same operation as in Production Example 1 was performed under the conditions shown in Table 1 below.

In all cases, the decrease in malodor was negligible.

With respect to the deodorized thioglycolic acid and the like prepared in Production Examples 1 and 2 and Comparative Production Examples 1 and 2, a panel of 20 people examined the change in odor with time. The results are shown in Table 2.

Example 1 The ammonium thioglycolate solution obtained in Production Example 1 was adjusted to be 50% as thioglycolic acid, and using this, a permanent wave preparation was prepared according to the following table, and a permanent wave treatment was performed. On the vine, no unpleasant odor was noticeable.

(First agent formulation) Ammonium thioglycolate solution (50% aqueous solution) 14.0% Polyoxyethylene hydrogenated castor oil 1.0 Perfume 0.2 Ammonia water, water (pH adjusted to 9.0 with ammonia water) Balance (Second agent formulation) Bromic acid Sodium 10.0% water balance Example 2 A first agent having the composition shown below was prepared, and the odor and
The amount of H ₂ S was measured by sensory test and head space gas chromatography (GC). The first agent is 50 ml of that 25 ml
It was sealed in a closed container of ml volume and left at 60 ° C. for 30 minutes. The sampling of the GC was performed by taking 100 μ of air from the upper part of the closed container. The result is shown in the third vote.

(Composition) Ammonium thioglycolate solution (50% aqueous solution) 14% Polyoxyethylene hydrogenated castor oil 1 Water (adjusted to pH 9 with ammonia) Balance (Measurement equipment) PerkinElmer Sigma 2000 column: 25% 1,2,3 -Tris (2-cyanoethoxy) propane (TCEP) 2m (Result)

Claims (2)

[Claims] 1. A method in which thioglycolic acid or an aqueous solution thereof or an aqueous solution of thioglycolate is heated at a temperature of 30 to 80 ° C.
A first permanent wave agent, which comprises deodorized thioglycolic acid or a salt thereof obtained by steam distillation at 300 Torr or less. 2. The first permanent wave agent according to claim 1, wherein the thioglycollate is selected from the group consisting of ammonium salt, monoethanolamine salt, diethanolamine salt and triethanolamine salt.