JP7732736B2 - Hair treatment method - Google Patents

Description

The present invention relates to a hair treatment method. More specifically, it relates to a hair treatment method that can make hair smooth and easy to comb, impart water repellency, etc., and maintain these effects for a long period of time.

Hair-washing cosmetics such as shampoos and conditioners, and hair-finishing cosmetics such as hair styling agents and hair treatments contain various hair care ingredients such as silicones. These hair care ingredients adsorb to and repair damaged areas of the hair, coating the hair and improving combability.

Hair treatment methods such as those described above that aim to provide hair treatment are required to have long-lasting effects, especially when carried out in hair salons, etc.

However, while polymers that have been incorporated into conventional hair cosmetics as hair care ingredients may restore hair's combability immediately after use, they tend to be easily washed away when washing, and many of them are inadequate in terms of long-lasting effects or feel when used.

Patent Document 1 discloses a hair cosmetic formulation containing a cationic polymer emulsion obtained by emulsion polymerization of a vinyl monomer having a reactive alkoxysilane group, a lipophilic vinyl monomer having an alkyl group, and an acrylic acid-based hydrophilic monomer with a cationic emulsifier. The alkoxysilane groups in this cationic polymer are hydrolyzed to form silanol groups, which undergo a dehydration condensation reaction to form a crosslinked structure and a strong film. However, the main chain of this polymer is a vinyl polymer with a polyvinyl structure, which has a strong resinous feel and makes hair feel stiff and rough, making it unsuitable for use.

Patent Document 2 describes a hair treatment method that uses a composition containing a silicone polymer having an alkoxy-(aminomethyl)-silyl group at the end. The silicone polymer used here is said to maintain the shape of the hair for a long time and to exhibit good cosmetic properties. When using a treatment agent containing an alkoxysilane component, uneven or excessive adhesion to the hair can sometimes result in poor usability.

Patent No. 4805482 Special Publication No. 2016-525534

The objective of the present invention is to provide a hair treatment method that can uniformly and appropriately apply ingredients with hair treatment effects to hair, restore the hydrophobicity, combability, and smoothness of damaged hair by appropriately heat-treating it, and maintain the effects for a long period of time, resulting in excellent long-lasting effects.

The inventors discovered that by using a hair treatment agent containing a specified amount of a copolymer whose main chain contains a polysiloxane structure and a polyoxyalkylene structure and whose side chains contain trialkoxysilane groups or silanol groups, and by incorporating appropriate rinsing and heating steps, it is possible to achieve hair treatment that has excellent long-lasting effects, high water-repellent properties, and smooth application, leading to the completion of the present invention.

That is, the present invention provides:
(1) applying to hair a hair treatment agent containing a copolymer having a polysiloxane structure and a polyoxyalkylene structure in its main chain and having a side chain having a trialkoxysilane group or a silanol group;
(2) a step of heat-treating the hair at 40°C to 230°C; and (3) a step of rinsing the hair.

The hair treatment method of the present invention uses a hair treatment agent containing a copolymer of a specific structure at a predetermined concentration, and includes a step of rinsing the hair before or after heating, thereby preventing excess hair treatment ingredients from remaining on the hair surface. Furthermore, the effects of the hair treatment of the present invention are highly sustained. By incorporating the hair treatment method of the present invention into a chemical treatment step such as permanent waving, straightening, dyeing, or bleaching, or before the step of applying the hair treatment agent, hair damaged by the chemical treatment can be instantly repaired, restoring smoothness, etc.
Furthermore, the copolymer of the specific structure used in the present invention imparts hydrophobicity (water repellency) to the hair surface, makes the hair quick-drying and smooth to the touch, makes the hair easier to manage, and improves heat resistance, chemical resistance, and resistance to pollutants (such as pollen), with these effects lasting for a long time.

The hair treatment method of the present invention comprises (1) a step of applying a hair treatment agent, (2) a heat treatment step, and (3) a rinsing step. Each step is described in detail below.

(1) Step of Applying Hair Treatment Agent In the hair treatment method according to the present invention, first, the hair treatment agent is applied to the hair.
The hair treatment agent used in the present invention contains a copolymer (hereinafter abbreviated as "crosslinked silicone POA copolymer") that contains a polysiloxane structure and a polyoxyalkylene structure in the main chain and has side chains containing trialkoxysilane groups or silanol groups.

The crosslinked silicone POA copolymer has excellent adhesion to hair due to the hydrophilic nature of the polyoxyalkylene structure in the main chain, the polysiloxane structure in the main chain imparts hydrophobic (water-repellent) properties to the hair surface, and the alkoxysilane or silanol groups in the side chain crosslink at relatively low temperatures to form a strong film, resulting in excellent long-lasting effects.

The polysiloxane structure constituting the main chain of the crosslinked silicone POA copolymer is made of polydialkylsiloxane, preferably polydimethylsiloxane, and some of the alkyl groups (preferably methyl groups) may be substituted with phenyl groups.

The polyoxyalkylene structure constituting the main chain of the crosslinked silicone POA copolymer of the present invention preferably contains at least one repeating unit selected from the group consisting of oxyethylene groups (EO), oxypropylene groups (PO), and oxybutylene groups (BO).

The crosslinked silicone POA copolymer of the present invention preferably further has a side chain composed of an organic group. Examples of the organic group that serves as the side chain include a hydrocarbon group (preferably an alkyl group, for example, a linear or branched alkyl group having approximately 1 to 30 carbon atoms, or a phenyl group) that may be optionally substituted with an amino group, a hydroxyl group, a carboxyl group, or the like. The hydrocarbon group preferably has an amino group, and the hydrogen atom of the amino group may be further substituted with an alkyl group, etc.

The crosslinked silicone POA copolymer of the present invention preferably further contains a nitrogen atom in its main chain, and the side chains are preferably bonded to the nitrogen atom.

A more specific example of a crosslinked silicone POA copolymer is Polysilicone-29 (INCI name). Polysilicone-29 is defined as a hybrid silicone compound obtained by reacting a dimethylsiloxane polymer having a glycidylpropyl group at the end with PEG-13 diglycidyl ether, diethylaminopropylamine, and aminopropyltriisopropoxysilane.

Commercially available crosslinked silicone POA copolymers may be used in the present invention. For example, the copolymer contained in a hair conditioner sold by Momentive Performance Materials under the trade name "Silsoft CLX-E" is particularly preferred. This copolymer is a compound belonging to the "Polysilicone-29" group. This copolymer contains a polysiloxane structure, a polyoxyalkylene structure, and a nitrogen atom in its main chain, and has a side chain containing a trialkoxysilane group and a side chain composed of an organic group. The polysiloxane structure contains polydimethylsiloxane, the polyoxyalkylene structure contains polyoxyethylene and polyoxyisopropylene, and the side chain is bonded to the nitrogen atom of the main chain. "Silsoft CLX-E" is a product containing the copolymer, dipropylene glycol, and water.

The amount of crosslinked silicone POA copolymer in the hair treatment agent used in the present invention is preferably 0.05% by mass or more, and preferably 0.1% by mass or more. For example, it can be 0.5% by mass or more, or even 1% by mass or more. Due to the copolymer's affinity for hair, the copolymer can thoroughly coat the entire hair, and removing excess copolymer by performing the rinsing step described below prevents the hair from becoming stiff. The upper limit of the amount of crosslinked silicone POA copolymer is usually 5.0% by mass or less, preferably 3.0% by mass or less, and more preferably 2.0% by mass or less. If the amount is less than 0.05% by mass, the intended effect will not be achieved, and if the amount exceeds 5.0% by mass, usability may be reduced.

The hair treatment agent of the present invention can be prepared in the form of a cream, mist, mousse, gel, spray, or the like, and is not particularly limited. The hair treatment agent may optionally contain other ingredients depending on the form. Preferably, it is provided in the form of a cream, mist, or gel.

For example, when preparing a cream, it is preferable to blend a crosslinked silicone POA copolymer, water, a higher alcohol, and a surfactant. The surfactant preferably includes a cationic surfactant such as a quaternary ammonium salt. The amount of cationic surfactant blended is preferably 0.1 to 2.0% by mass of the hair treatment agent, more preferably 0.2 to 1.5% by mass. In addition to the cationic surfactant, a nonionic surfactant and/or an amphoteric surfactant may also be included. The amount of nonionic surfactant or amphoteric surfactant blended is not particularly limited, but is typically 0.1 to 3.0% by mass, more preferably 0.3 to 1.5% by mass. On the other hand, using only an anionic surfactant as the surfactant may not achieve the desired effect, so it is preferable to avoid blending an anionic surfactant alone. The amount of higher alcohol blended is typically 0.1 to 20% by mass, preferably 1.0 to 10% by mass. The amount of water blended is not particularly limited, but is preferably 5% by mass or more of the cosmetic, typically around 50 to 90% by mass.

When preparing a mist, it is preferable to blend a crosslinked silicone POA copolymer, a lower alcohol, and a surfactant. The surfactant in the mist is preferably a cationic surfactant such as a quaternary ammonium salt. From the standpoints of stability and feel when used, the amount of cationic surfactant blended is preferably 0.01 to 1.0% by mass of the hair treatment agent, more preferably 0.03 to 0.5% by mass, and even more preferably 0.05 to 0.5% by mass. Lower alcohol refers to alcohols with 5 or fewer carbon atoms, such as ethanol. From the standpoints of stability and effectiveness, the amount of lower alcohol blended is preferably 10 to 60% by mass, more preferably 20 to 50% by mass.

Other optional ingredients to be incorporated into the hair treatment agent of the present invention can be appropriately selected from ingredients commonly used in cosmetics, pharmaceuticals, etc., provided that the amount incorporated is within a range that does not impair the effects of the present invention. Examples of such optional ingredients include, but are not limited to, oils, powdered ingredients, natural polymers, synthetic polymers, thickeners, UV absorbers, moisturizers, sequestering agents, pH adjusters, skin nutrients, vitamins, antioxidants, antioxidant aids, fragrances, etc.

In this step, the hair treatment agent as described above is applied to the hair in a manner appropriate for its form. If the hair treatment agent is a cream, mousse, or gel, the agent is taken up in the hands and applied to the hair, spreading it evenly over the entire hair. If the hair treatment agent is a mist or spray, it is filled into a container appropriate for the form, then sprayed onto the hair, and optionally spread evenly over the entire hair with the hands.

(2) Heat Treatment Step In the heat treatment step, the hair to which the hair treatment agent has been applied is heated to a predetermined temperature.
The heat treatment temperature is 40°C to 230°C, preferably 60°C to 200°C, more preferably 60°C to 180°C, even more preferably 80°C to 150°C, and most preferably 80°C to 120°C. If the temperature is below 40°C, the effect will not last long enough. If the temperature exceeds 230°C, the heat may damage the hair, and particularly dyed (colored) hair is likely to experience a significant change in color (fading).

The heating means is not particularly limited, but it is preferable to use a hair iron or hair dryer.

In the (3) rinsing step of the hair treatment method of the present invention, the hair to which the hair treatment agent has been applied is rinsed. Although water is preferably used for rinsing, water containing a cleansing component such as a surfactant may also be used.
By rinsing, excess hair treatment agent applied to the hair surface can be removed, resulting in a good finish.

In the hair treatment method of the present invention, the hair to which the hair treatment agent has been applied in step (1) may be subjected to the (2) heat treatment step followed by the (3) rinsing step, or the (3) rinsing step may be performed followed by the (2) heat treatment step. However, omitting either the (2) heat treatment step or the (3) rinsing step results in usability problems such as stickiness of the treated hair. In particular, not performing the heat treatment significantly reduces the duration of the effect.
It is also preferable to dry the hair before the heating step.

(4) Chemical Treatment Step The hair treatment method of the present invention can incorporate chemical treatment steps such as hair dyeing (coloring), permanent wave formation, or hair straightening (straightening). These chemical treatments preferably include at least one treatment selected from the following hair dyeing (coloring) treatment, permanent wave formation treatment, and hair straightening (straightening) treatment. For example, the hair dyeing treatment may be performed in combination with the permanent wave formation treatment or the hair straightening treatment.

・Hair dyeing (coloring)
The hair dyeing (coloring) treatment in the present invention includes permanent hair dyeing treatment, typically oxidative dyeing using a first agent containing an oxidative dye and a second agent containing an oxidizing agent such as hydrogen peroxide, and hair bleaching (decoloring) treatment using a first agent containing an alkaline agent and a second agent containing hydrogen peroxide. It may also be temporary hair dyeing treatment using a coloring agent such as a pigment or an acid dye.

Permanent wave formation in the present invention includes a treatment for forming a permanent wave using a first agent containing a reducing agent, typical examples of which are thioglycolic acid or cysteine, and a second agent containing an oxidizing agent. It also includes a straight perm treatment using the above-mentioned reducing agent and oxidizing agent.

・Hair straightening (straightening)
The hair straightening (straightening) treatment in the present invention refers to a treatment using, for example, a treatment agent containing glyoxylic acid as a main component, and does not include the straight perm treatment using the above-mentioned reducing agent and oxidizing agent. The hair straightening treatment agent using glyoxylic acid may further contain a guanidine salt and/or urea to improve the straightening effect (see Japanese Patent No. 5947340).

In the hair treatment method of the present invention, the above-mentioned chemical treatment step is preferably carried out before the step of (1) applying a hair treatment agent. If (4) chemical treatment is carried out after (1) application of a hair treatment agent, (2) heat treatment, and (3) rinsing, the penetration of the chemical treatment agent into the hair is inhibited, and sufficient effects tend not to be obtained.

On the other hand, by carrying out the hair treatment method of the present invention (steps (1) to (3)) following the chemical treatment step, hair damaged by the chemical treatment agent can be effectively repaired. Step (1) of the hair treatment method of the present invention can be carried out immediately (for example, within 30 minutes, 10 minutes, or 5 minutes) after the chemical treatment step (4) is completed, and an optional washing step may be inserted in between.

When the hair treatment method of the present invention (steps (1) to (3)) is carried out after a hair dyeing (coloring) treatment, it is preferable to set the heating temperature in the heat treatment step (2) to a low temperature (for example, 180°C or less, preferably 150°C or less, more preferably 120°C or less) in order to prevent fading.

The present invention will be described in further detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, blend amounts are expressed in mass %.

Each hair treatment agent was prepared in accordance with the formulation shown in Tables 1 and 2 below in a conventional manner.

The hair samples were then subjected to each treatment step using the following method. The order of application of each step is shown in Tables 3 and 4.

The hair samples used for the evaluation were as follows:
Dyeing (coloring): 8cm long, 1g weight human gray hair strands. Permanent wave treatment: 30cm long, 2g weight human hair strands. If no dyeing or permanent wave treatment is performed: 15cm long, 0.5g weight damaged hair strands.

The details of each step are as follows.
(1) Step of applying a hair treatment agent (application step)
A hair treatment is applied to the hair sample.
(2) Heat treatment step (heating step)
The hair sample was heated at a predetermined temperature. The heating temperature and heating means are shown in Tables 3 and 4.
(3) Rinse-off process (water washing process)
The hair sample is rinsed with water.
(4) Chemical treatment process - Dyeing (coloring) treatment: Dye the hair using an acidic hair dye (Hair Primiense, manufactured by Shiseido Professional).
Permanent wave formation treatment: Permanent waves are formed using a perm treatment solution (CREATOR, manufactured by Shiseido Professional).
Hair straightening treatment: Hair straightening treatment is performed using a treatment solution containing glyoxylic acid.

Hair samples that underwent each process in the order listed in Tables 3 and 4 above were evaluated from the following perspectives. The evaluation results are shown in Tables 3 and 4. A rating of C means no practical problems, B is good, and A is even better (excellent).

<Usability>
The hair samples were examined by trained researchers and evaluated according to the following criteria:
Evaluation criteria:
A: The hair is not stiff or sticky and feels very smooth to the touch.
B: The hair is not stiff or sticky and feels smooth to the touch.
C: The hair is slightly stiff and sticky, but feels smooth to the touch.
D: Hair is stiff and sticky and not smooth to the touch.

<Sustained effect>
2 μL of water was dropped onto the surface of the hair sample, and the droplet was photographed under a microscope. From the photographed image, the left and right angles of the water droplet on the hair were measured, and the average value was taken as one measurement. The same measurement was repeated three times, and the average value was taken as the contact angle value.
Next, the sample was repeatedly washed with a 10% SLES solution shampoo containing no conditioning ingredients, and the same measurements as above were carried out to calculate the rate of change in contact angle (using the following formula).
Contact angle change rate (%) = 100 × (contact angle after cleaning/contact angle before cleaning)
The sustained effect was evaluated as follows based on the rate of change in contact angle calculated by the above formula.
A: The rate of change in contact angle is 90% or more.
B: The rate of change in contact angle is 80% or more and less than 90%.
C: The rate of change in contact angle is 70% or more and less than 80%.
D: The rate of change in contact angle is less than 70%.

<Effects on chemical treatment>
・Effects on dyeing (coloring) <Color effects>
The color tone of the hair samples treated in each example was compared visually with Comparative Example 5 (Table 4), in which only dyeing was performed as the chemical treatment, and the change in color tone was evaluated according to the following criteria.
A: There is absolutely no change in color compared to Comparative Example 5.
B: There is almost no change in color compared to Comparative Example 5.
C: A slight change in color is observed compared to Comparative Example 5.
D: There is a large change in color compared to Comparative Example 5.

・Effects on permanent wave formation process <Perm effects>
The condition of the permanent waves of the hair samples treated in each example was visually compared with that of Comparative Example 5 (Table 4), in which only perm treatment was performed as the chemical treatment, and the changes were evaluated according to the following criteria.
A: Compared to Comparative Example 5, there was absolutely no change in the way the perm was applied.
B: Compared to Comparative Example 5, there is almost no change in the way the perm is applied.
C: Perm effect is slightly inferior to that of Comparative Example 5.
D: Compared to Comparative Example 5, the perm effect is significantly inferior.

As shown in Tables 3 and 4, hair samples that were subjected to (1) application of a hair treatment agent, followed by (2) heat treatment and (3) water washing treatment, had a hydrophobic surface, resulting in a smooth feel and excellent usability. It was also confirmed that the effects were excellent in duration. It was found that the above effects could be obtained whether the heat treatment was followed by water washing, or whether the water washing was followed by heat treatment (Examples 1 and 2).

On the other hand, in Comparative Example 2, where no heat treatment was performed, the hair felt sticky and stiff, and the lasting effect was insufficient. In Comparative Example 3, where no water rinsing treatment was performed, the hair did not become smooth and remained sticky.

In Comparative Example 4, in which chemical treatment was performed after the treatment method of the present invention, adverse effects were particularly observed on permanent wave formation. Furthermore, when dyeing (coloring) was performed as the chemical treatment, significant fading (color change) occurred when the heating temperature exceeded 230°C (Comparative Example 1). However, when the heating temperature was set to 200°C, fading was suppressed to an acceptable level (Example 3), and almost no fading occurred at temperatures below 180°C (Examples 1 and 4-6).

Furthermore, similar results were obtained when Hair Treatment Product 2, whose formulation is shown in Table 2, was used as the hair treatment product. Similar results were obtained when chemical treatments, such as hair dyeing (coloring) or permanent waving, were followed by hair straightening treatment using glyoxylic acid.

Claims (3)

(1) applying a hair treatment agent containing a cationic surfactant composed of polysilicone-29 and a quaternary ammonium salt to hair that has been subjected to at least one chemical treatment selected from the group consisting of a hair dyeing treatment, a permanent wave forming treatment, and a hair straightening treatment;
(2) heat-treating the hair at 80°C to 120°C; and (3) rinsing the hair,
A hair treatment method characterized by being carried out in the order of step (1), then step (2), and then step (3). (1) applying a hair treatment agent containing a cationic surfactant composed of polysilicone-29 and a quaternary ammonium salt to hair that has been subjected to at least one chemical treatment selected from the group consisting of a hair dyeing treatment, a permanent wave forming treatment, and a hair straightening treatment;
(2) heat-treating the hair at 80°C to 120°C; and (3) rinsing the hair,
A hair treatment method characterized by being carried out in the order of step (1), then step (3), and then step (2). The hair treatment method according to claim 1 or 2, further comprising a step of drying the hair prior to step (2).