Thickener

A thickener comprising a fatty acid amide ether compound represented by the formula (1—1):

• wherein R1 represents a straight-chain or branched alkyl or alkenyl group which has 5 to 21 carbon atoms and may be substituted with at least one hydroxyl group, R2 represents a straight-chain or branched alkyl group having 1 to 12 carbon atoms.

A thickener comprising a fatty acid amide ether compound represented by the formula (1-2):

• wherein R1 represents a straight-chain or branched alkyl or alkenyl group which has 5 to 21 carbon atoms and may be substituted with at least one hydroxyl group, R2 represents a straight-chain or branched alkyl group having 1 to 12 carbon atoms.

A method of using the fatty acid amide ether compound represented by the formula (1) as a thickener comprising:

• mixing the fatty acid amide ether compound with a liquid
• wherein R1 represents a straight-chain or branched alkyl or alkenyl group which has 5 to 21 carbon atoms and may be substituted with at least one hydroxyl group, R2 represents a straight-chain or branched alkyl group having 1 to 12 carbon atoms and R3 represents an alkylene group having 2 to 12 carbon atoms.

A method of thickening a surfactant comprising

• mixing the fatty acid amide ether compound represented by the formula (1) with the surfactant:
• wherein R1 represents a straight-chain or branched alkyl or alkenyl group which has 5 to 21 carbon atoms and may be substituted with at least one hydroxyl group, R2 represents a straight-chain or branched alkyl group having 1 to 12 carbon atoms and R3 represents an alkylene group having 2 to 12 carbon atoms.

A fatty acid amide ether compound represented by the formula (1):

• wherein R1 represents a straight-chain or branched alkyl or alkenyl group which has 5 to 21 carbon atoms and may be substituted with at least one hydroxyl group, R2 represents a straight-chain or branched alkyl group having 1 to 12 carbon atoms and R3 represents an alkylene group having 2 to 12 carbon atoms.

A fatty acid amide ether compound represented by the formula (1—1):

• wherein R1 represents a straight-chain or branched alkyl or alkenyl group which has 5 to 21 carbon atoms and may be substituted with at least one hydroxyl group, R2 represents a straight-chain or branched alkyl group having 1 to 12 carbon atoms.

A fatty acid amide ether compound represented by the formula (1-2):

• wherein R1 represents a straight-chain or branched alkyl or alkenyl group which has 5 to 21 carbon atoms and may be substituted with at least one hydroxyl group, R2 represents a straight-chain or branched alkyl group having 1 to 12 carbon atoms.