PROBLEM TO BE SOLVED: To provide a composition for keratin fibers, such as hair, which can be used for transforming or reforming keratin fibers, and can impart sufficient reforming efficiency for keratin fibers, such as hair, e.g., high wave strength, excellent wave depth, curl regularity, elasticity and flexibility of the curled keratin fibers, preferably to provide a cosmetic composition and also to provide a method of reforming, particularly permanent-waving or straightening the keratin fibers, preferably the hair.SOLUTION: The present invention provides a composition for keratin fibers, such as hair, containing (a) at least one kind of reducing agent (b) at least one kind of fat amino acid or a salt thereof and (c) at least one kind of aromatic amino acid or a salt thereof. The invention also provides a method of reforming, particularly permanent-waving or straightening the keratin fibers, preferably the hair comprising applying the composition on the keratin fibers optionally rinsing the keratin fibers applying an oxidation composition containing at least one kind of oxidant on the keratin fibers optionally rinsing and/or drying the keratin fibers. The composition or method according to the present invention can be used for transforming or reforming keratin fibers, preferably the hair, and can impart sufficient reforming efficiency, e.g., high wave strength, excellent wave depth, curl regularity, elasticity and flexibility of the curled keratin fibers to the keratin fibers.SELECTED DRAWING: NoneCOPYRIGHT: (C)2016,JPO&INPIT【課題】ケラチン繊維を変形する又は再成形するのに使用することができ、毛髪等のケラチン繊維に十分な再成形効率、例えば高いウェーブ強度、優れたウェーブ深度、カールの規則性、並びにカールされたケラチン繊維の弾性及び柔軟性を付与することができる、毛髪等のケラチン繊維用組成物、好ましくは化粧用組成物を提供すること。また、ケラチン繊維、好ましくは毛髪を再成形する、特にパーマネントウェーブ化する又は直毛化する、方法を提供すること。【解決手段】(a)少なくとも1種の還元剤と、(b)少なくとも1種の脂肪アミノ酸又はその塩と、(c)少なくとも1種の芳香族アミノ酸又はその塩とを含む、毛髪等のケラチン繊維用組成物を提供する。また、該組成物をケラチン繊維上に適用する工程と、任意選択でケラチン繊維をすすぐ工程と、少なくとも1種の酸化剤を含む酸化組成物をケラチン繊維上に適用する工程と、任意選択でケラチン繊維をすすぐ、及び/又は、乾燥させる工程とを含む、ケラチン繊維、好ましくは毛髪を、再成形する、詳細にはパーマネ
