PROBLEM TO BE SOLVED: To provide a hair treatment agent which achieves a high hair extension effect without using a reducing agent or oxidant which causes serious damage to the hair, and to provide a hair treatment method which enables the hair to extend more effectively and readily than conventional methods, without hurting the hair in excess.SOLUTION: The invention relates to a hair treatment agent containing (a) 10-25 mass% of glyoxylic acid and (b) 0.05-3 mass% of guanidine salt and/or urea, wherein a pH is in the range of 1.0-2.5. The invention also relates to a hair treatment method comprising (1) applying the hair treatment agent to the hair, (2) leaving the hair as it is, (3) rinsing the hair with water, (4) drying the hair, and (5) correcting the hair with an iron for hairdressing.SELECTED DRAWING: NoneCOPYRIGHT: (C)2016,JPO&INPIT【課題】 毛髪に大きなダメージを与える還元剤や酸化剤を用いずに、高い毛髪伸長効果を実現する毛髪処理剤、並びに、毛髪を過度に傷めることなく、従来よりも効果的かつ容易に毛髪を伸長することができる毛髪処理方法を提供する。【解決手段】 毛髪処理剤が(a)10~25質量%のグリオキシル酸と、(b)0.05~3質量%のグアニジン塩及び/又は尿素とを含有し、1.0~2.5の範囲のpHを有する。また、毛髪処理方法が(1)前記毛髪処理剤を毛髪に塗布する工程、(2)毛髪を放置する工程、(3)毛髪を水洗する工程、(4)毛髪を乾燥させる工程、及び(5)整髪用アイロンで毛髪を矯正する工程を含む。【選択図】 なし
