JP6225697B2 - Solid soap - Google Patents

Description

  The present invention relates to a solid soap, and more particularly, to a solid soap excellent in quick foaming property, foam amount, foam elasticity, foam persistence, persistent moisture after rinsing, moldability and storage stability. .

Conventionally, soap, which is a higher fatty acid alkali salt, has been mainly used as a cleaning agent for skin such as the face and body. Soap not only gives a unique refreshing feeling after washing, but also has good biodegradability and is an environmentally friendly base. Among them, solid soap is still widely used as the most common skin cleanser.
Currently, fatty acids derived from beef tallow, palm oil, coconut oil and palm kernel oil are used as the fatty acids constituting the solid soaps that are generally produced. About mass% is contained. However, although the unsaturated fatty acid is effective for maintaining the solubility and moldability of the soap, there is a problem that the storage stability after the soap is formed is lowered, and discoloration and odor deterioration are likely to occur.

  On the other hand, as a disadvantage of soap, there is also a problem that an unpleasant feeling of tension occurs after washing and the feeling becomes worse. Therefore, in general, attempts have been made to add a moisturizing feeling after rinsing by blending moisturizing ingredients such as polyhydric alcohols and plant extracts, but most of the moisturizing ingredients run off during rinsing. Therefore, the present condition is that the moisturizing effect cannot be fully exhibited.

  In order to solve these problems, for example, Patent Document 1 proposes a solid soap in which a saturated fatty acid alkali metal salt, an alkylbetaine, and bentonite are combined. Although this solid soap has good storage stability, it does not have the effect of providing quick foaming properties, foam quality, and a sustained moist feeling after rinsing, and also has a problem that it tends to crack during molding. It was.

  Patent Document 2 proposes a mechanical soap composition containing a polyoxyalkylene type nonionic surfactant and having a water content of more than 15%. This machine-kneaded soap composition has good moldability and does not cause an unpleasant feeling during washing, but is insufficient in terms of quick foaming, foam amount, and elasticity of foam. Has not yet given a lasting moist feeling.

Japanese Patent Laying-Open No. 2005-082685 JP 2002-114994 A

  An object of the present invention is to provide a solid soap excellent in quick foaming property, foam amount, foam elasticity, foam persistence, sustained moisture after rinsing, moldability and storage stability.

  As a result of intensive studies by the present inventors in order to solve the above problems, a specific fatty acid alkali metal salt, a specific fatty acid, a polyhydric alcohol, a specific polyoxyethylene sorbitan fatty acid ester and water are combined in a specific ratio. The present inventors have found that the above-mentioned objective soap composition can be obtained, and have completed the present invention.

That is, the solid soap of the present invention is selected from (a) component: 70 to 92.8% by mass of fatty acid alkali metal salt based on the total amount of solid soap , and (b) component: lauric acid, myristic acid and palmitic acid. 1 to 9% by mass of one or more fatty acids based on the total amount of solid soap , component (c): 0.1 to 3% by mass of polyhydric alcohol based on the total amount of solid soap , component (d): ethylene oxide 0.1 to 8 wt% an average addition mole number is 80 to 100 mole polyoxyethylene sorbitan monolaurate with respect to the solid soap total amount, (e) component: water 6 against bar soap total amount 18 wt% had containing, with respect to the fatty acid total amount constituting the component (a), 15 to 35 wt% lauric acid, myristic acid is 55 to 75% by weight and palmitic acid 5-20 The total amount of lauric acid, myristic acid and palmitic acid is 95 to 100% by mass, the alkali metals in component (a) are potassium and sodium, and the mass ratio of potassium / sodium is 1/4. 3/2, the sum of the component (b) and the component (d) is 2 to 10% by mass, and the mass ratio of the component (b) / (d) is 1/4 to 4. It is a solid soap characterized by

  According to the solid soap of the present invention, it is possible to obtain an effect of being excellent in quick foaming property, foam amount, foam elasticity, foam persistence, sustained moisture feeling after rinsing, moldability and storage stability.

Hereinafter, embodiments of the present invention will be described.
The solid soap of the present invention comprises (a) component: fatty acid alkali metal salt, (b) component: fatty acid, (c) component: polyhydric alcohol, (d) component: polyoxyethylene sorbitan monolaurate, and (e) Ingredient: Contains water. Hereinafter, each component will be sequentially described.
Hereinafter, the “effect of imparting a continuous moisture feeling after rinsing” is also referred to as a “moisture imparting effect”.

[(A) component: fatty acid alkali metal salt]
The component (a) is a fatty acid alkali metal salt, and the fatty acid constituting the component (a) contains at least lauric acid, myristic acid and palmitic acid. The content of lauric acid in the total fatty acid constituting the component (a) is 15 to 35% by mass, preferably 20 to 30% by mass, and the content of myristic acid is 55 to 75% by mass, preferably 60 to 70%. The content of palmitic acid is 5 to 20% by mass, preferably 5 to 15% by mass.
If the content of lauric acid is less than 15% by mass, the rapid foaming property may be lowered and the amount of foam may be reduced, and if it is more than 35% by mass, the elasticity and moldability of the foam may be lowered. When the content of myristic acid is less than 55% by mass, the quick foam property, the elasticity of the foam and the persistence of the foam may be lowered, and when it is more than 75% by mass, the solubility may be lowered. If the amount of palmitic acid is less than 5% by mass, melting and collapse are likely to occur. If the amount is more than 20% by mass, the rapid foaming property is lowered, and there is a possibility that the feeling of tightness at the time of rinsing is increased.

  Moreover, the total content of lauric acid, myristic acid and palmitic acid among all fatty acids constituting the component (a) is 95 to 100% by mass, preferably 98 to 100% by mass. When the total content of lauric acid, myristic acid and palmitic acid is less than 95% by mass, the quick foaming property, solubility and moldability may be lowered, and the feeling of holding during rinsing may be increased.

  (A) As a fatty acid which comprises a component, you may contain the other fatty acid except lauric acid, myristic acid, and palmitic acid. Examples of other fatty acids include saturated fatty acids such as stearic acid, behenic acid, isostearic acid, and hydroxystearic acid. The content of other saturated fatty acids with respect to the total fatty acids constituting the component (a) is preferably 5% by mass or less, particularly preferably 2% by mass or less. However, it is preferable that the unsaturated fatty acid is not substantially contained as the fatty acid constituting the component (a). For example, it is preferable that the content of the unsaturated fatty acid with respect to all fatty acids constituting the component (a) is 1% by mass or less, particularly 0.5% by mass or less.

  The alkali metal in the fatty acid alkali metal salt which is the component (a) is potassium and sodium, and the mass ratio of potassium / sodium is 1/4 to 3/2, preferably 1/2 to 1. If the mass ratio of potassium / sodium is less than 1/4, the solubility and storage stability may be lowered, and if it is more than 3/2, the moisturizing effect may be weakened, and melting and collapse may occur. Examples of the alkali agent containing the alkali metal as a component include hydroxides and carbonates.

  The content of the component (a) in the solid soap is 70 to 92.8% by mass, preferably 75 to 90% by mass, and more preferably 80 to 90% by mass. When the content of the component (a) is less than 70% by mass, there is a possibility that quick foaming property, foam amount, foam elasticity, foam sustainability, moldability and storage stability may be lowered, and 92.8% by mass. If it exceeds 1, moldability may be reduced.

[(B) component: fatty acid]
The component (b) is a fatty acid, for example, a linear or branched fatty acid having 8 to 20 carbon atoms. For example, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, oleic acid, hydroxystearic acid, linoleic acid, coconut oil fatty acid, palm oil fatty acid, palm kernel oil fatty acid, soybean oil fatty acid, Sunflower oil fatty acid, castor hardened fatty acid and the like can be mentioned, and one or two of these fatty acids can be used. Preferred are lauric acid, myristic acid, and palmitic acid, and particularly preferred are lauric acid and myristic acid.

  The content of the component (b) in the solid soap is 1 to 9% by mass, preferably 1 to 6% by mass, and more preferably 1 to 4% by mass. When the content of the component (b) is less than 1% by mass, the quick foaming property, the elasticity of the foam, the sustainability of the foam and the moldability may be lowered, and the moisturizing effect may be weakened. Moreover, when content of (b) component exceeds 9 mass%, there exists a possibility that a quick foam property and a moldability may fall.

[(C) component: polyhydric alcohol]
Component (c) is a polyhydric alcohol, and examples thereof include propylene glycol, dipropylene glycol, glycerin, diglycerin, polyglycerin, and 1,3-butylene glycol, and glycerin is preferred.
Content of (c) component in solid soap is 0.1-3 mass%, Preferably it is 0.1-1 mass%. When the content of the component (c) is less than 0.1% by mass, the solubility and fast foaming property are lowered, and the foam amount may be reduced. In addition, the moisturizing effect is weakened, and further, the soap base mass is lowered, so that the moldability of the soap is lowered, and the productivity and the yield may be lowered. When the content of the component (c) exceeds 3% by mass, the viscosity of the soap base is increased, the moldability is lowered, and the sweating phenomenon due to the leaching of glycerin in a specific environment occurs, resulting in a decrease in productivity and yield. May be incurred.

[(D) component: polyoxyethylene sorbitan monolaurate]
The component (d) is polyoxyethylene sorbitan monolaurate, and is a nonionic surfactant obtained by adding ethylene oxide to sorbitan fatty acid ester which is a partial ester of sorbitol or sorbitan and a fatty acid.
Sorbitan fatty acid ester can manufacture a monoester body, a diester body, and a triester body by setting suitably the ratio of sorbitan and a fatty acid. The sorbitan fatty acid ester used as a starting material for the component (d) used in the present invention preferably contains a monoester as a main component (for example, 50% by mass or more). When the component (d) obtained using a sorbitan fatty acid ester mainly composed of a diester or triester as a starting material is used, the foam quality may be lowered.

  (D) The average addition mole number of ethylene oxide in a component is 80-100 mol, Preferably it is 80-95 mol, More preferably, it is 80-90 mol. If the average added mole number of ethylene oxide is less than 80 moles, the persistence of the foam may be lowered. Further, when the average added mole number of ethylene oxide exceeds 100 mol, the viscosity at the time of melting becomes extremely high and handling becomes difficult, so that not only industrial production may be difficult, but also the soap base is not sticky. May also occur.

  The content of the component (d) in the solid soap is 0.1 to 8% by mass, preferably 0.5 to 5% by mass, and more preferably 1 to 5% by mass. When the content of the component (d) is less than 0.1% by mass, the quick foaming property, the elasticity of the foam, the sustainability of the foam and the moldability may be lowered, and the moisturizing effect may be weakened. When the content of the component (d) exceeds 8% by mass, the soap base becomes too sticky and moldability is deteriorated, and there is a possibility that the soap becomes a sticky soap.

[(E) component: water]
The component (e) is water, and for example, distilled water, purified water, ion exchange water, pure water and the like can be used. Content of the (e) component in a solid soap is 6-18 mass%, Preferably it is 8-12 mass%. (E) When content of a component is less than 6 mass%, there exists a possibility that a moldability may fall and a fall of productivity may be caused. When the content of the component (e) exceeds 18% by mass, the productivity and yield may be reduced due to an increase in the viscosity of the soap base, the occurrence of dandruff, a decrease in moldability, blocking, and the like.

  In the solid soap of the present invention, the total content of the component (b) and the component (d) is 2 to 10% by mass, preferably 2 to 8% by mass, more preferably 3 to 7% by mass. is there. When the total content is less than 2% by mass, the elasticity of the foam, the persistence of the foam and the moldability may be lowered, and the moisturizing effect may be weakened. On the other hand, when the total content exceeds 10% by mass, the rapid foaming property is lowered, and the foam amount may be reduced.

  Moreover, mass ratio of (b) component / (d) component is 1 / 4-4, Preferably it is 1 / 2-3, More preferably, it is 1 / 2-2. If the mass ratio is less than 1/4, foam elasticity, foam persistence, moldability may be reduced, and if it exceeds 4, fast foamability, foam elasticity and moldability are reduced. The amount of foam may be reduced.

  It is also possible to mix | blend the additive currently used for the washing | cleaning agent with the solid soap of this invention in the range which does not impair the performance of this invention. For example, higher alcohols, silicone derivatives, protein derivatives, squalane, jojoba oil, olive oil, castor oil, lanolin, lecithin, oily bases such as fatty acid esters of polyethylene glycol, lower alcohols such as ethanol and isopropyl alcohol, polyoxyethylene alkyl ethers , Nonionic surfactants such as alkanolamides, amphoteric surfactants such as amidopropyldimethylaminoacetic acid betaine, alkylaminoacetic acid salts, amide amino acid salts, acylmethyl taurine salts, alkyl ether sulfates, amide ether sulfates Anionic surfactants such as carboxyvinyl polymer, water-soluble polymers such as carboxymethylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose, acids that are pH adjusters And alkali, disinfectants, chelating agents, antioxidants, ultraviolet absorbers may be blended natural extracts derived from animals and plants, dyes, perfumes and the like.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples.
[Examples 1 to 3, Comparative Examples 1 to 9]
Solid soap was prepared using the various components shown in Table 1 by the method shown in the following production examples. In addition, except the number shown in the column of “(b) / (d)” in Table 1, the content (% by mass) in the solid soap is shown.

<Production example>
A higher fatty acid having the fatty acid composition shown in Table 1 was placed in a 5 L double-arm kneader (Irie Shokai Co., Ltd., PNV-5 type), heated to about 80 ° C., and 28% by mass sodium hydroxide aqueous solution and 28 A mixed solution of a mass% potassium hydroxide aqueous solution was added and stirred and mixed at 85 to 95 ° C. for about 5 minutes, and then a fatty acid and glycerin were added to obtain a soap base. Thereafter, polyoxyethylene sorbitan ester and other additives were added, and the water content was adjusted while continuing to stir and mix at that temperature and drying. The composition was kneaded three times with a plodder (manufactured by Nippon Chemical Industry Co., Ltd., mini soap podder) and a roll mill (manufactured by IMEX, BR-150 type bench roll), and then a soap bar was obtained with the plodder. Thereafter, it was molded with a stamping machine (manufactured by Tamari Kiko) to prepare a solid soap.
About the obtained solid soap, (1) fast foaming property, (2) foam amount, (3) foam elasticity, (4) foam persistence, (5) persistent moisture feeling after rinsing, (6 The moldability and (7) storage stability were evaluated by the following methods.

(1) Quick-foaming property 10 females (20-40 generations) were panelists, and the quick-foaming property when foaming solid soap was determined according to the following criteria.
2 points: When you feel foaming very quickly.
1 point: When it feels to foam quickly.
0 point: When foaming is felt slow.
The total score of 10 people was calculated and evaluated as follows.
◎: Total score of 16-20 points ○: Total score of 11-15 points △: Total score of 6-10 points ×: Total score of 0-5 points

(2) Amount of foam Using 10 women (20-40s) as a panelist, the amount of foam when foaming solid soap was determined according to the following criteria.
2 points: When the amount of foam is felt to be very large.
1 point: When the amount of foam is felt to be large.
0 point: When the amount of foam is felt to be small.
The total score of 10 people was calculated and evaluated as follows.
◎: Total score of 16-20 points ○: Total score of 11-15 points △: Total score of 6-10 points ×: Total score of 0-5 points

(3) Elasticity of bubbles The elasticity of bubbles when foaming solid soap was determined according to the following criteria, with 10 women (20-40 generations) as panelists.
2 points: When the foam feels very elastic.
1 point: When the foam feels elastic.
0 points: When the foam feels insufficient elasticity.
The total score of 10 people was calculated and evaluated as follows.
◎: Total score of 16-20 points ○: Total score of 11-15 points △: Total score of 6-10 points ×: Total score of 0-5 points

(4) Sustainability of foam The tenth female (20-40 generations) was made into a panel, and the persistence of foam when foaming solid soap was determined according to the following criteria.
2 points: When the foam feels very persistent.
1 point: When it feels that the foam has persistence.
0 points: When the foam feels insufficient.
The total score of 10 people was calculated and evaluated as follows.
◎: Total score of 16-20 points ○: Total score of 11-15 points △: Total score of 6-10 points ×: Total score of 0-5 points

(5) Sustained moist feeling after rinsing With 10 women (20-40s) as a panelist, after foaming solid soap, rinse thoroughly with running water and wipe off moisture with a towel. Judged by the criteria of.
2 points: When it feels moist and stays on the skin for a long time.
1 point: When you feel moist but do not feel after a while.
0 point: When a moist feeling was not felt.
The total score of 10 people was calculated and evaluated as follows.
◎: Total score of 16-20 points ○: Total score of 11-15 points △: Total score of 6-10 points ×: Total score of 0-5 points

(6) Formability The ease of molding when a soap bar was molded using a stamping machine was determined according to the following criteria.
◯: There are almost no problems in any of cracks, cracks, base materials, and mold separation, and the yield is 99% or more.
(Triangle | delta): There exists a problem in any of a crack, a crack, a base material unity, and mold separation, and a yield is 90% or more and less than 99%.
X: There is a problem in any one of cracks, cracks, base materials, and mold separation, and the yield is less than 90%.

(7) Storage stability The color and odor after solid soap was allowed to stand for 6 months in a constant temperature bath at 40 ° C. were determined according to the following criteria.
○: No discoloration or smell
Δ: Slightly discolored or slightly unpleasant odor.
X: Large color change or unpleasant odor is strong.

The solid soaps of Examples 1 to 3 according to the present invention were excellent in quick-foaming property, foam amount, foam elasticity, foam persistence, sustained moisture feeling after rinsing, moldability and storage stability. .
On the other hand, in Comparative Examples 1-9, sufficient performance was not obtained.
Since the solid soap of Comparative Example 1 does not contain the component (d), the elasticity of the foam and the persistent moisture after rinsing are insufficient, and the quick foaming, the foam sustainability and the moldability are low. .
Since the solid soap of Comparative Example 2 has a low content of the component (b), the quick foaming property, the persistent moist feeling after rinsing, and the moldability are insufficient, and the elasticity of the foam and the persistence of the foam are low. It was low.
Since the solid soap of Comparative Example 3 contains polyoxyethylene monolaurate sorbitan (30E.O.) having an average addition mole number of ethylene oxide of 30 mol instead of the component (d), it has fast foaming properties and foam elasticity. Sex and persistent moisture after rinsing were insufficient.

Since the solid soap of Comparative Example 4 contains sorbitan polyoxyethylene monooleate (30E.O.) instead of the component (d), it has quick foaming properties, foam elasticity, and a persistent moisture feeling after rinsing. Was insufficient and the storage stability was low.
Since the solid soap of Comparative Example 5 contained oleic acid instead of palmitic acid as the fatty acid constituting component (a), the foam elasticity, foam persistence, moldability, and storage stability were low.
In the solid soap of Comparative Example 6, since the mass ratio of the component (b) / component (d) was less than ¼, the foam persistence was insufficient and the foam elasticity and moldability were low.
In the solid soap of Comparative Example 7, the mass ratio of the component (b) / component (d) exceeds 4, so that the moldability is insufficient, the foamability is low, the foam persistence is low, and the amount of foam is low. There were few.
In the solid soap of Comparative Example 8, since the total of the component (b) and the component (d) is less than 2% by mass, the elasticity of the foam, the persistence of the foam, the moldability is low, and the persistence after rinsing The moist feeling was poor.
In the solid soap of Comparative Example 9, since the sum of the component (b) and the component (d) exceeded 10%, the quick foaming property was low and the amount of foam was small.

Claims (1)

(A) component: 70-92.8 mass% of fatty acid alkali metal salt with respect to the total amount of solid soap ,
(B) component: 1 to 9% by mass of one or more fatty acids selected from lauric acid, myristic acid and palmitic acid based on the total amount of solid soap ,
(C) component: 0.1-3 mass % of polyhydric alcohol with respect to the total amount of solid soap ,
(D) component: 0.1-8 mass % of polyoxyethylene sorbitan monolauric acid ester whose average added mole number of ethylene oxide is 80-100 mol with respect to the total amount of solid soap ,
(E) component: water has 6-18 wt% including the solid soap total amount
(A) lauric acid is 15 to 35% by mass, myristic acid is 55 to 75% by mass and palmitic acid is 5 to 20% by mass, and lauric acid, myristic acid and palmitic acid are based on the total amount of fatty acids constituting the component (a) The total acid is 95 to 100% by mass, the alkali metals in component (a) are potassium and sodium, the mass ratio of potassium / sodium is 1/4 to 3/2, d) The total amount of the component is 2 to 10% by mass, and the mass ratio of (b) component / (d) component is 1/4 to 4, solid soap.