JP2007126384A - Pretreatment agent for acid hair dye - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pretreatment agent for an acid hair dye, obtained by targeting improved dye-affinity and fastness, and hardly causing damage of the hair. <P>SOLUTION: The pretreatment agent for the acid hair dye contains urea and benzyl alcohol formulated therewith, and has pH 5.0-11.0. A copolymer composition comprising a dimethyldiallylammonium chloride and acrylamide, and having 2,000-40,000 average molecular weight is preferably compounded therewith in the pretreatment agent for the acid hairdye. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a pretreatment agent for acidic hair dyes that causes less hair damage for the purpose of improving dyeability and fastness when applying the acidic hair dye.

As is well known, acidic hair dyes (hair manicure) can be used more easily than two-component oxidative hair dyes, so the market needs are increasing, but further improvements are made in terms of dyeability and dyeing fastness. Is required.
In order to improve the dyeing power and fastness of an acidic hair dye, a pretreatment agent used before applying the acidic hair dye is known. Conventional acid hair dye pretreatment agents are known to be made acidic by containing benzyl alcohol, but the effect of improving dyeing power is very weak.
In addition, it is known that an alkaline agent and an organic solvent are blended in a pretreatment agent for acidic hair dye to have a pH of 7.5 to 11.0 and a reducing agent is blended (Patent Document 1), and urea is added to the hair dye. Attempts have also been made to obtain a hair dye excellent in fastness by blending (Patent Document 2).
JP 2000-169344 A JP 09-278636 A

  However, the pretreatment agent composition containing the alkali agent and organic solvent described in Patent Document 1 and having a pH of 7.5 to 11.0 is not necessarily sufficient in improving the dyeability and fastness, and contains a reducing agent. Although this effect is improved, hair damage is considerably increased. On the other hand, in the case of using an acid dye, the hair dye of Patent Document 2 increases the fastness of the dyed hair by adjusting the pH to 4 or less, but damage to the hair increases, and urea is decomposed and cannot be stably blended. Therefore, the improvement effect by urea cannot be obtained.

The objective of this invention is providing the pretreatment agent for acidic hair dyes which is excellent in the effect which improves the dyeing property and fastness of the acidic hair dye applied later, and there is little damage to hair.

  In view of the above circumstances, as a result of intensive studies by the present inventors, there is little damage to hair by blending urea and benzyl alcohol and containing substantially no reducing agent or acidic dye, and the pH is 5.0 to By adjusting to 11.0, it discovered that the pre-processing agent which mix | blended urea stably and was excellent in the dyeing | staining property and fastness improvement effect was obtained. Further, it has been found that the dyeing property and fastness of an acidic hair dye to be applied later are further improved by further blending a copolymer composition having an average molecular weight of 2,000 to 40,000 consisting of dimethyldiallylammonium chloride and acrylamide. The present invention has been completed.

That is, the present invention is a pretreatment for an acidic hair dye characterized in that urea and benzyl alcohol are blended, has a pH of 5.0 to 11.0, and does not substantially contain a reducing agent or an acidic dye. It is an agent.

In the pretreatment agent for acidic hair dye, the compounding amount of urea is 0.1 to 30% by mass, and the compounding amount of benzyl alcohol is 0.1 to 30% by mass.
Moreover, in the said pretreatment agent for acidic hair dye, a reducing agent and / or an acidic dye are not included substantially.

In the pretreatment agent for acidic hair dye, a copolymer composition having an average molecular weight of 2,000 to 40,000 consisting of dimethyl diallyl ammonium chloride and acrylamide is further blended.

  The pretreatment agent for acidic hair dye of the present invention has little damage to hair and can sufficiently improve the dyeability and fastness of the acidic hair dye to be applied later.

  Hereinafter, embodiments of the present invention will be described in detail.

<Urea>
Urea has excellent water retention ability, and can effectively break hydrogen bonds in hair. Acid hair dyes are usually adjusted to a pH of 2 to 4, and the hair swells slightly even when applied to the hair. However, by adding urea to the pretreatment agent, the hair tends to swell and the penetrability of the acid dye into the hair increases. Further, since the acid dye is water-soluble, the urea is retained in the hair, so that a permeation route is sufficiently ensured and smoothly penetrated. As a result, the dyeing power is improved by penetration of many acidic dyes into the hair, and the fastness is improved by deep penetration.
The blending amount of urea in the present invention is 0.1 to 30% by mass, preferably 1.0 to 20% by mass, and more preferably 3 to 10% by mass. When 30 mass% or more is blended, the stability tends to deteriorate.

<Benzyl alcohol>
The benzyl alcohol used for this invention is 0.1-30 mass% in a composition, Preferably it is 1-15.0 mass%, More preferably, 2-8 mass% is mix | blended. By including benzyl alcohol in the composition, it is possible to improve the dyeability of an acidic hair dye to be applied later.

<Copolymer composition having an average molecular weight of 2,000 to 40,000 consisting of dimethyldiallylammonium chloride and acrylamide> (hereinafter referred to as “copolymer (A)”)
The copolymer (A) used in the present invention comprises dimethyldiallylammonium chloride (hereinafter sometimes abbreviated as DADMAC), acrylamide (hereinafter sometimes abbreviated as AAm), water and isopropyl alcohol (hereinafter referred to as IPA). A copolymer obtained by copolymerization by a conventional method using a polymerization initiator in a mixed solvent, which is a cationic copolymer having an average molecular weight of 2000 to 40000. The monomer composition ratio of the copolymer is preferably DADMAC: AAm of 20:80 to 60:40, and is a random copolymer composed of the following structural units. The purified copolymer (A) may be used as an aqueous solution in which it is dissolved at an appropriate concentration, or may be used after being dried until the pure content becomes 100%.

The average molecular weight of the copolymer (A) is a weight average molecular weight (hereinafter abbreviated as Mw) by gel permeation chromatography (hereinafter abbreviated as GPC), and the average molecular weight is 2000 to 40000. Preferably, it is about 3000-33000. The measurement conditions for GPC are shown below.
<GPC measurement conditions>
Column: OHpak SB-804HQ,
OHpak SB-803HQ,
OHpak SB-802HQ (all manufactured by Showa Denko KK)
Column temperature: 40 ° C.
Detector: RI,
Solvent: 0.25M acetic acid + 0.05M sodium chloride (pH = 3.5),
Flow rate: 0.7 ml / min,
Sample concentration: 0.5%
Injection volume: 50 μl,
Standard: Pullulan,
(Made by Showa Denko; Shodex STANDARD P-82)

  In addition, the weight average molecular weight of the copolymer of DADMAC and AAm conventionally blended in cosmetics has a large molecular weight having an order of several hundred thousand. For example, the weight average molecular weight of ME polymer 09W (manufactured by Toho Chemical Industry Co., Ltd.) is about 450,000, and the copolymer weight of the high molecular weight is very different from the copolymer (A) having an average molecular weight of 2000 to 40000 used in the present invention. It is a coalescence.

  The blending amount of the copolymer in the present invention is not particularly limited, but is usually 0.01 to 50% by mass, preferably 0.1 to 20% by mass, and more preferably 1 to 10% by mass on the product form. is there.

  The present invention is characterized in that it contains substantially no reducing agent and / or acid dye. “Substantially free” means that it is not contained in the composition at all, or even if it is contained, it is 0.01% by weight or less, and the reducing agent and acid dye function to reduce or dye the hair. It means the degree of not exhibiting. In addition, in the case of an acid dye, a trace amount (0.01 weight% or less) of the grade aiming at coloring to a composition base may be contained.

In addition, a viscosity modifier, a colorant, a fragrance | flavor, a gloss imparting agent, etc. can be mix | blended in the range which does not impair the effect of this invention.
The dosage form of the treatment agent of the present invention can take various dosage forms such as lotion (liquid), mist, gel, foam, spray and the like. As an application method, the treatment agent of the present invention is applied to hair, washed with water and towel-dried, and then a normal acidic hair dye may be applied. It should be noted that, after application to the hair, leaving it for several minutes at room temperature or warming further promotes the penetration of the drug into the hair and tends to enhance the effect of the present application.

  The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. Unless otherwise specified, the blending amount is expressed in mass% with respect to the system in which the component is blended.

"Synthesis example 1 of copolymer (A)"
A glass flask having a capacity of 3 liters equipped with a thermometer, a reflux condenser and a stirrer was charged with 834 g of water and 1172 g of IPA and heated to 60 ° C. Next, a mixed solution of AAm 173 g (2.4 mol), 65% DADMAC aqueous solution 233 g (0.9 mol) and water 92 g, 20% sodium persulfate aqueous solution 97 g, and 20% sodium bisulfite aqueous solution 211 g were separately added. It was dripped at the reactor under stirring from the dropping funnel over 6 hours. After completion of the dropping, the reaction solution was kept at 60 ° C. for 6 hours to complete the polymerization. After completion of the polymerization, stirring was stopped, the lower phase solution separated into two phases was separated, washed with 1400 g of 50% IPA aqueous solution, allowed to stand, and then phase-separated to separate the lower phase solution. This washing operation was performed once more to obtain a polymer solution containing the lower phase.
An equal amount of water was added thereto, and IPA was distilled off under reduced pressure at 80 ° C. under reduced pressure. It was Mw 3,000 as a result of measuring GPC of the obtained polymer aqueous solution.
<GPC measurement conditions>
Column OHpak SB-804HQ
OHpak SB-803HQ
OHpak SB-802HQ
(Both made by Showa Denko KK)
Column temperature: 40 ° C
Detector: RI
Solvent: 0.25M acetic acid + 0.05M sodium chloride (pH = 3.5)
Flow rate: 0.7 ml / min Sample concentration: 0.5%
Injection volume: 50 μl
Standard: Pull Run
(Made by Showa Denko; Shodex STANDARD P-82)

"Examples 4 to 4, Comparative Examples 1 to 4"
Adjust the pretreatment agent for acidic hair dye with the composition shown in Table 1 by a conventional method (after dissolving the thickener in purified water, add various components and mix uniformly, and adjust the pH). The dyeability, fastness, hair damage degree, and composition stability were evaluated. In addition, each evaluation was implemented with the following method.

<Dyeability test>
An excessive amount of the pretreatment composition was applied to the white hair bundle (15 g of the composition with respect to 2 g of hair) and left at 25 ° C. for 5 minutes. After 5 minutes, it was washed with water to wash away the pretreatment composition and towel-dried. An excessive amount (15 g) of acidic hair dye (RX-T Active Color Natural Brown, manufactured by Shiseido Professional Co., Ltd.) was applied to this hair bundle and left at 30 ° C. for 10 minutes. After 10 minutes, the hair bundle was dried by shampooing twice. Compared with the dyeing when the pretreatment agent is not used, the hair bundle dyeing is very well dyed and the pretreatment agent is highly effective in improving the dyeability. Evaluation when the effect of improving the dyeability is slightly high, evaluation when the difference in dyeing is not felt and the effect of improving the dyeing property of the pretreatment agent is △, evaluation when the pretreatment agent is poor in dyeing and the dyeing property is inhibited Was marked with x.

<Robustness test>
The hair bundle used in the dyeability evaluation test was immersed in a 2% aqueous sodium lauryl sulfate solution and shaken at 30 ° C. for 30 minutes. Thereafter, it was washed with water and allowed to air dry. At this time, compared with the degree of color fading of the hair bundle not using the pretreatment agent, the evaluation when the color fading is very small is ◎, the evaluation when the color fading is slightly small is ○, the degree of color fading The evaluation when there was no difference was Δ, and the evaluation when the dyeing was lighter than the hair bundles being compared was bad, and the evaluation was x.

<Hair damage test>
The strength of the hair was measured using AUTOGRAPH (AGS-H) manufactured by Shimadzu Corporation, and the degree of damage was evaluated. In this experiment, healthy hair of the same person was used, and the measurement was averaged 10 times using the same data. ○ When the hair treated with the pretreatment agent (applied excessive amount and left at 25 ° C for 5 minutes and then washed with water) has no difference in strength from that before the treatment, ○, evaluation when the strength is slightly reduced The evaluation when the strength was reduced was evaluated as x.

<Composition stability test>
Fill the resin container and screw tube with the pretreatment agent composition, leave it at room temperature for 3 months, observe the appearance and measure the pH, and evaluate when there is almost no change compared to immediately after production, The evaluation when there was a slight change was indicated by Δ, and the evaluation when there was a considerable change was indicated by ×.

Example 5:
Urea 0.5
Benzyl alcohol 3.0
ME polymer DAM (3000)
(Product number: Toho Chemical Co., Ltd. 7% aqueous solution of copolymer (A)) 15.0
Dipropylene glycol 2.0
2-Hydroxy-n-caprylic acid 1.0
Hydroxyethyl cellulose 3.0
Diamond former Z732
(Part number, manufactured by Mitsubishi Chemical Corporation) 1.0
n-Methylpyrrolidone 1.0
Sucrose fatty acid ester 0.1
Procyanidin 0.5
d-limonene 0.5
Ammonia water Adjusted to pH 10 Fragrance Appropriate amount Purified water 100 parts Adjusted total 100.0

Example 6:
Urea 2.0
Benzyl alcohol 1.0
ME polymer DAM (3000) 0.01
Ethanol 5.0
Propyl gallate 0.5
Dicetyl phosphate 1.0
Cetanol 8.0
Liquid paraffin 0.5
Isopropyl palmitate 3.0
Stearyltrimethylammonium chloride 3.0
Silylated hydrolyzed soy protein 1.0
Arginine 0.1
Pinene 1.0
Lactic acid Appropriate amount Sodium lactate adjusted to pH 7 Perfume proper amount Purified water 100 parts Adjusted total 100.0

Example 7:
Urea 20.0
Benzyl alcohol 10.0
Xanthan gum 0.1
Carboxyvinyl polymer 3.0
Benzyloxyethanol 2.0
Tocopherol 0.1
γ-hexanolactone 5.0
α-olefin oligomer 1.0
Ceteth-10 phosphate 0.5
Hexanoic acid 0.5
Tannic acid 0.5
Glycolic acid 2.0
Disodium hydrogen phosphate adjusted to pH 5 Fragrance appropriate amount Purified water 100 parts Adjusted total 100.0

Example 8:
Urea 8.0
Benzyl alcohol 3.0
ME polymer DAM (3000) 5.0
Cetanol 11.0
Propylene glycol 3.0
Ethanol 5.0
Dimethicone 1.5
Aminopropyl dimethicone 0.5
Cetyl octanoate 5.0
Sodium L-glutamate 0.5
Lecithin 0.1
Polyoxyethylene oleyl ether 2.0
Glyceryl stearate 0.5
Stearyltrimethylammonium chloride 2.0
Tartaric acid 0.1
Sodium citrate pH 6 adjusted fragrance appropriate amount purified water 100 parts adjusted total 100.0

Claims (4)

  A pretreatment agent for acidic hair dyes, which contains urea and benzyl alcohol and has a pH of 5.0 to 11.0.   The pretreatment agent for acidic hair dye according to claim 1, wherein the compounding amount of urea is 0.1 to 30% by mass and the compounding amount of benzyl alcohol is 0.1 to 30% by mass. Pre-treatment agent.   The pretreatment agent for acidic hair dye according to claim 1 or 2, wherein the pretreatment agent for acidic hair dye contains substantially no reducing agent and / or acidic dye. The acidic hair dye pretreatment agent according to any one of claims 1 to 3, further comprising a copolymer composition comprising dimethyldiallylammonium chloride and acrylamide having an average molecular weight of 2000 to 40000. Pretreatment agent for acidic hair dye.