External Skin Preparation And Skin Cleanser

A rough skin improving agent comprising a block-type alkylene oxide derivative represented by formula (I):

• Y—[O(EO)a-(AO)b-(EO)c-R]k (formula I),
• wherein Y is a residue given by removing hydroxyl groups from a polyhydric alcohol having 3 to 6 hydroxyl groups, and k is the number of hydroxyl groups of the polyhydric alcohol,
• wherein EO is an oxyethylene group, AO is an oxyalkylene group having 3 to 6 carbon atoms, said EO and AO groups being arranged in blocks,
• wherein the products, a k, b k, and c k, are the average addition mole numbers of the respective oxyethylene groups and the oxyalkylene group,
• wherein the oxyalkylene group has 3 to 6 carbon atoms and
• wherein 0≦a k≦100, 1≦b k≦100, 0≦c k≦100, (a+c) k>1,
• wherein the percentage of oxyethylene groups in formula (I) with respect to the sum of all oxyethylene groups (EO) and oxyalkylene groups having 3 to 6 carbon atoms (AO), such percentage represented by ((a+c)÷(a+b+c)), is 10 to 80 mass %,
• wherein groups R are hydrocarbon groups having 1 to 4 carbon atoms, which are either identical to or different from each other.

A usability-improving agent comprising a block-type alkylene oxide derivative represented by formula (I):

• Y—[O(EO)a-(AO)b-(EO)c-R]k (formula I)
• wherein Y is a residue given by removing hydroxyl groups from a polyhydric alcohol having 3 to 6 hydroxyl groups, and k is the number of hydroxyl groups of the polyhydric alcohol,
• wherein EO is an oxyethylene group, AO is an oxyalkylene group having 3 to 6 carbon atoms, said EO and AO groups being arranged in blocks,
• wherein the products, a k, b k, and c k, are the average addition mole numbers of the respective oxyethylene groups and the oxyalkylene group,
• wherein the oxyalkylene group has 3 to 6 carbon atoms and
• wherein 0≦a k≦100, 1≦b k≦100, 0≦c k≦100, (a+c) k>1,
• wherein the percentage of oxyethylene groups in formula (I) with respect to the sum of all oxyethylene groups (EO) and oxyalkylene groups having 3 to 6 carbon atoms (AO), such percentage represented by ((a+c)÷(a+b+c)), is 10 to 80 mass %,
• wherein groups R are hydrocarbon groups having 1 to 4 carbon atoms, which are either identical to or different from each other.

A skin cleanser comprising 0.01 to 70 mass % of

• (a) a block-type alkylene oxide derivative represented by formula (I):
• Y—[O(EO)a-(AO)b-(EO)c-R]k (formula I)
• wherein Y is a residue given by removing hydroxyl groups from a polyhydric alcohol having 3 to 6 hydroxyl groups, and k is the number of hydroxyl groups of the polyhydric alcohol,
• wherein EO is an oxyethylene group, AO is an oxyalkylene group having 3 to 6 carbon atoms, said EO and AO groups being arranged in blocks,
• wherein the products, a k, b k, and c k, are the average addition mole numbers of the respective oxyethylene groups and the oxyalkylene group,
• wherein the oxyalkylene group has 3 to 6 carbon atoms and
• wherein 0≦a k≦100, 1≦b k≦100, 0≦c k≦100, (a+c) k>1,
• wherein the percentage of oxyethylene groups in formula (I) with respect to the sum of all oxyethylene groups (EO) and oxyalkylene groups having 3 to 6 carbon atoms AO such percentage represented by ((a+c)÷(a+b+c)), is 10 to 80 mass %,
• wherein groups R are hydrocarbon groups having 1 to 4 carbon atoms, which are either identical to or different from each other, and
• (b) 0.1 to 20 mass % of a moisturizer.