Abstract: [Problem] A valine, isoleucine, leucine mixture which is excellent in the reduction of bitter taste and improved dissolution speed is provided. [Solving Means] The above problem is solved by a solid solution composed of three amino acids of valine, isoleucine, leucine, and a solid solution composed of these and at least one of acid selected from the group consisting of neutral aliphatic amino acid, neutral hydroxy amino acid, neutral acid amide amino acid, acidic amino acid, basic amino acid, hydroxy acid.

Abstract: An N-long-chain acyl neutral amino acid ester containing a straight-chain or branched-chain, saturated or unsaturated acyl group having from 6 to 22 carbon atoms, where the hydrocarbon group of the alcohol constituting the ester is a straight-chain or branched-chain, saturated or unsaturated hydrocarbon group having from 1 to 10 carbon atoms disclosed herein is an oily material suitable for cosmetic compositions, which provide an excellent feeling upon use and also an excellent hair conditioning effect to a cosmetic composition containing the same. An ultraviolet ray-absorbing composition containing the N-long-chain acyl neutral amino acid ester or/and an N-long-chain acyl acidic amino acid diester is provided, which also has excellent feel.

Abstract: Herein is disclosed an oily material composition comprising, as effective components, both a specific alkyl or alkenyl ester of an N-long chain acyl neutral amino acid and a specific sterol ester of an N-long chain acyl neutral amino acid, or further an amphipathic substance in addition to the said two kinds of esters, which composition has both good moisturizing property and good moisture-permeating property, as well as good water-incorporating property and good emulsification stability, and shows a good feel on use (i.e., non-stickiness, good compatibility, no heavy touch and good spreadability), and shows, when incorporated in a cosmetic composition or a dermal external agent composition, an advantage of giving moisturizing property and moisture-permeating property as well as emulsification stability thereto and of giving a good feel on use.

Abstract: Herein are disclosed N-long chain acyl-neutral amino acid polyglycerin esters composed of a polyglycerin having a degree of glycerin polymerization of not smaller than 4 and an N-long chain acyl-neutral amino acid having an acyl group with from 6 to 22 carbon atoms and a nonionic surfactant composition comprising, as an active ingredient, at least one of said N-long chain acyl-neutral amino acid polyglycerin esters, which are favorably safe and which, when incorporated in cosmetic compositions or percutaneous preparations, are sensorially good.

Abstract: An artificial hair made of a fibers comprising a poly-.alpha.-amino acid derivative insoluble to water and alcohols and represented by one of the following general formulae (1)-(4): ##STR1## providing that R in each of the above formula (1)-(4) is R.sup.a, R.sup.b and R.sup.c represented, respectively, by the following general formula (5), (6) or (7): ##STR2## or made or polyamino acid urethane fiber comprising a copolymer of an amino acid N-carboxy anhydride and a polyurethane, in which the copolymer is subjected to an amidation reaction with an organic diamine and an organic amine having amino groups and mercapto groups or disulfide groups and to shaping into a fibrous form.The artificial hair has a dyeability, shape retainability, natural and soft and flexible feeling, excellent tough and brushing property, as well as has natural color and gloss and toughness like that natural protein fiber.