JPH04235116A - Pack for cosmetic - Google Patents

Abstract

PURPOSE:To provide a cosmetic pack easily takable with a finger, resistant to drip, uniformly and easily peelable from the skin without leaving the pack on an edge, exhibiting good shape-retainability and spreadability of jelly and capable of forming a tough film. CONSTITUTION:The objective cosmetic pack contains, as essential components, (A) a chitosan preferably having a deacetylation degree of 75-90% and a viscosity of 2-2,000cp as 1% aqueous solution and (B) a film-forming polymer, e.g. polyvinyl alcohol, copolymer of vinyl alcohol and an alkyl vinyl ether or a resin emulsion, preferably a polyvinyl alcohol especially having a molecular weight of 20,000-150,000 and a saponification degree of 75-95%. The amount of the component A in the total composition is preferably 0.001-10wt.%, especially 0.005-5wt.% and that of the component B is preferably 5-50wt.%, especially 5-40wt.%. The composition is further incorporated with a small amount of an organic acid (e.g. lactic acid or citric acid), hydrochloric acid, etc., to adjust the pH to 3.5-5.5, especially 4-5 in order to improve the water-solubility of the component A.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cosmetic pack that contains chitosan and has good jelly shape retention and spreadability, as well as strong film-forming properties.

0002

[Prior Art and Problems to be Solved by the Invention] Cosmetic packs (hereinafter simply referred to as "packs") are used for skin care, and their purpose is to provide temporary relief by applying them to the skin. It isolates the skin from the outside world, allows the moisture contained in the pack agent and the moisture brought from under the skin to be retained in the stratum corneum, making it soft, giving the skin an appropriate sense of tension while the pack is drying, and further removing the pack agent. Sometimes, this involves removing dirt and grime from the skin and making it clean. To achieve these purposes, packs include those that form a film and peel off when applied to the skin, mainly on the face (peel-off type), and those that either form a film or do not form a film when applied to the skin. There are products that can be washed off with something (wash-off type).

[0003] In recent years, peel-off type packs have been preferably used from the viewpoint of convenience of use and effectiveness. Conventional peel-off type packs have coating agents,
It contains moisturizers, powders, oily ingredients, ethanol, water, etc., and most of them are in the form of jelly.

[0004] However, these conventional pack agents
It was not possible to obtain good thixotropy, and it was difficult to satisfy both the properties of jelly shape retention and spreadability on the skin. In other words, in order to make the pack spread well, it is necessary to reduce the amount of film agent in order to lower the viscosity.As a result, the jelly's shape retention deteriorates and becomes difficult to remove from the fingers. In order to improve the jelly shape retention of the agent, it is necessary to increase the amount of the coating agent, which has the disadvantage that the viscosity increases and the spreadability when applied to the skin is significantly reduced.

[0005] In order to improve these drawbacks, sodium carboxymethyl cellulose, collagen, xanthan gum, etc. have been added as supplements, but none of these have been practically satisfactory.

[0006]Furthermore, when the pack agent is removed, it is difficult to peel it off uniformly, and there is also the problem that it remains on the edges. To improve this, it is necessary to improve the film properties, and if the amount of film agent is increased for this purpose, the viscosity increases and the spreadability when applied to the skin is significantly reduced.

[0007]Therefore, there has been a desire for a pack agent that has excellent jelly shape retention and spreadability as well as strong film-forming properties.

[0008]

[Means for Solving the Problems] Under these circumstances, the present inventors conducted intensive research and found that if chitosan and film-forming polymer are used together, the jelly will have excellent shape retention and spreadability, and will also be tough. It was discovered that a pack agent having film-forming properties can be obtained, and the present invention was completed.

[0009] That is, the present invention provides (A) chitosan;
and (B) contains a film-forming polymer and has a pH of 3.5.
5.5.

The chitosan component (A) used in the present invention has a degree of deacetylation of 75 to 90%, and 1% of these
Preferably, the aqueous solution has a viscosity of 2 to 2,000 cp. Here, in order to improve the water solubility of chitosan, the pH can be adjusted to 3.5 to 5.5, especially 4 to 5, by adding a small amount of organic acid such as lactic acid or citric acid, or hydrochloric acid. preferable.

[0011] These chitosan can be used alone or in combination of two or more, and the total amount of chitosan in the total composition is 0.001~
It is preferable to add 10% by weight, particularly 0.005 to 5% by weight.

Examples of the film-forming polymer (B) include polyvinyl alcohol, copolymers of vinyl alcohol and alkyl vinyl ether, and resin emulsions, with polyvinyl alcohol being particularly preferred. Polyvinyl alcohol has a molecular weight of 20,000~
150,000 and a degree of saponification of 75 to 95%, and commercially available products include the Gohsenol EG series (manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd.). As a copolymer of vinyl alcohol and alkyl vinyl ether,
98 to 80 mol% of vinyl alcohol monomer units and 1 carbon number as shown in JP-A No. 60-94904
A copolymer consisting of 2 to 20 mol % of linear or branched alkyl vinyl ether monomer units of 6 to 6, preferably having an average molecular weight of 30,000 to 200,000. Examples of the resin emulsion include vinyl acetate emulsion, isoprene rubber latex, acrylic resin emulsion, vinyl acetate acrylate, polybutadiene latex, and styrene-butadiene copolymer.

These film-forming polymers are preferably blended in an amount of 5 to 50% by weight, particularly 5 to 40% by weight, in the total composition as polymer solid content. If it is less than 5% by weight, it will be difficult to form a film, and if it exceeds 50% by weight, the amount of water will be small, resulting in high viscosity, which will cause disadvantages such as difficulty in use, and will also make manufacturing difficult, which is not preferable. .

In addition to the above-mentioned essential ingredients, the pack agent of the present invention contains ingredients commonly used in cosmetics, such as ethylene glycol, diethylene glycol, triethylene glycol, higher polyethylene glycols, propylene glycol, dipropylene glycol, and the like. The above polypropylene glycols, butylene glycols such as 1,3-butylene glycol and 1,4-butylene glycol, glycerin, diglycerin, higher polyglycerins, sorbitol, mannitol, xylitol,
Sugar alcohols such as maltitol, ethylene oxide (hereinafter abbreviated as EO) and propylene oxide (hereinafter abbreviated as PO) adducts of glycerin, EO of sugar alcohols
, PO adducts, monosaccharides such as galactose, glucose, fructose and their EO and PO adducts, polysaccharides such as maltose and lactose, and polyhydric alcohols such as their EO and PO adducts; liquid paraffin, squalane, petrolatum,
Hydrocarbons such as solid paraffin, olive oil, jojoba oil,
Natural oils such as evening primrose oil, coconut oil, beef tallow, ester oils such as isopropyl myristate, cetyl isooctanoate, neopentyl glycol dicaprate, silicone oils such as methyl silicone, methylphenyl silicone, isostearic acid, oleic acid, etc. Oily components such as higher fatty acids;
Surfactants such as POE alkyl ether, POE branched alkyl ether, POE sorbitan ester, POE glycerin fatty acid ester, POE hydrogenated castor oil, sorbitan ester, glycerin fatty acid ester, polyglycerin fatty acid ester; vitamins, anti-inflammatory agents, bactericidal agents, and activators. Agents such as UV absorbers; water-swellable clay minerals such as montmorinite, saponite, hecrite, vegum, knivia, and smectone; carrageenan,
Other polymers such as xanthan gum, sodium alginate, pullulan, polysaccharides such as methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, synthetic polymers such as carboxyvinyl polymer, polyvinylpyrrolidone; titanium oxide, kaolin, mica, sericite , extender pigments such as zinc white, talc, etc., and pigments such as polymer powders such as polymethyl methacrylic acid and nylon powder, etc., may be appropriately blended within a range that does not impair the effects of the present invention.

The pack agent of the present invention can be manufactured by a conventional method.

[0016]

[Effects of the Invention] The pack agent of the present invention has good jelly shape retention and spreadability, and also has strong film-forming properties. Therefore, it is easy to use with fingers, there is no dripping, and even when peeling off, the pack agent does not remain on the edges and can be peeled off uniformly and well.

[0017]

[Examples] Next, the present invention will be further explained with reference to Examples. Example 1 A pack agent having the composition shown in Table 1 was manufactured and its usability was evaluated. The results are shown in Table 1. (Manufacturing method) Components 1 to 10 and 12 to 18 were heated and mixed, dissolved, and cooled to 40° C., and then component 11 was mixed and cooled to room temperature to obtain a pack agent. (Evaluation method) A panel of experts used the pack agent and evaluated the ease of spreading, dripping, ease of peeling, and toughness of the film, and the evaluation was made using the following criteria. 1. Ease of spreading the pack ◎: More than 80% of the expert panelists were satisfied that it was easy to spread. ○: More than 50% of the expert panelists were satisfied that it was easy to spread. ×: Less than 50% of the expert panelists were not satisfied that it was easy to extend. 2. Pack agent dripping ◎: More than 80% of the expert panelists were satisfied that there was no dripping. ○: More than 50% of the expert panelists were satisfied that there was no dripping. ×: Less than 50% of the expert panelists were not satisfied with the dripping. 3. Ease of peeling off the pack ◎: More than 80% of the expert panelists were satisfied that no residue remained on the edges. ○: More than 50% of the expert panelists were satisfied that no residue remained on the edges. ×: Unsatisfied if less than 50% of the expert panelists remained at the edge. 4. Toughness of the film of the pack agent ◎: More than 80% of the expert panelists were satisfied that the film was strong. ○: More than 50% of the expert panelists were satisfied that the film was strong. ×: Less than 50% of the expert panelists were satisfied that the film was strong.

[0018]

[Table 1]

Claims (1)

[Claims] 1. A cosmetic pack comprising (A) chitosan and (B) a film-forming polymer, and having a pH of 3.5 to 5.5.