Metal corrosion inhibitor

A composition comprising:

• a carboxyl group-containing polymer;
• and
• a compound (X),
• wherein the compound (X) is represented by the following formula (2):
• wherein R1, R2, and R3 are the same as or different from each other and are each a hydrogen atom or a methyl group;
• R4 is a hydrogen atom or a C1-C30 hydrocarbon group;
• AOs are the same as or different from each other and are each an oxyalkylene group;
• n is an average number of moles of the oxyalkylene group added and is 1 to 300;
• x is 0 to 4;
• R5 is a C1-C4 divalent hydrocarbon group;
• M1 is a hydrogen atom, a metal atom, an ammonium group, a quaternary ammonium group, or an organic amine group;
• M2 is a hydrogen atom, a metal atom, an ammonium group, a quaternary ammonium group, an organic amine group, or a C1-C30 hydrocarbon group, and
• the compound (X) is present in an amount of from 0.01 to 5 mass % relative to 100 mass % of the carboxyl group-containing polymer.

A method for storing and/or transporting a carboxyl group-containing polymer, the method comprising:

• mixing a compound (X) with the carboxyl group-containing polymer so that a concentration of the compound (X) is 50 to 30000 ppm;
• and
• placing the mixture of the carboxyl group-containing polymer and the compound (X) in a container for storing and/or transporting,
• wherein the compound (X) is a compound represented by the following formula (2):
• wherein R1, R2, and R3 are the same as or different from each other and are each a hydrogen atom or a methyl group;
• R4 is a hydrogen atom or a C1-C30 hydrocarbon group;
• AOs are the same as or different from each other and are each an oxyalkylene group;
• n is an average number of moles of the oxyalkylene group added and is 1 to 300;
• x is 0 to 4;
• R5 is a C1-C4 divalent hydrocarbon group;
• M1 is a hydrogen atom, a metal atom, an ammonium group, a quaternary ammonium group, or an organic amine group;
• M2 is a hydrogen atom, a metal atom, an ammonium group, a quaternary ammonium group, an organic amine group, or a C1-C30 hydrocarbon group.

A method for inhibiting corrosion of a metal article by a carboxyl group-containing polymer, comprising:

• exposing the metal article to a composition including the carboxyl group-containing polymer,
• wherein the composition further comprises a compound (X) as a corrosion inhibitor,
• wherein the compound (X) is a compound represented by the following formula (2):
• wherein R1, R2, and R3 are the same as or different from each other and are each a hydrogen atom or a methyl group;
• R4 is a hydrogen atom or a C1-C30 hydrocarbon group;
• AOs are the same as or different from each other and are each an oxyalkylene group;
• n is an average number of moles of the oxyalkylene group added and is 1 to 300;
• x is 0 to 4;
• R5 is a C1-C4 divalent hydrocarbon group;
• M1 is a hydrogen atom, a metal atom, an ammonium group, a quaternary ammonium group, or an organic amine group;
• M2 is a hydrogen atom, a metal atom, an ammonium group, a quaternary ammonium group, an organic amine group, or a C1-C30 hydrocarbon group.