COATING MATERIAL
A coating material is a coating material used for applying a coating film formed on a coating made of a zinc-containing material formed in contact with a surface of a metal material and is composed of a binder, a first inorganic material, and a second inorganic material. The binder is composed of an organic resin and does not contain metallic zinc and a zinc alloy. The first inorganic material is composed of a sulfate having a solubility lower than 5 g/100 mL with respect to water. The second inorganic material is soluble in water, exhibits alkalinity if dissolved in water, and has a solubility lower than 5 g/100 mL with respect to water.
1 . A coating material used for applying a coating film formed on a coating made of a zinc-containing material formed in contact with a surface of a metal material, comprising:
a binder made of an organic resin which does not contain metallic zinc or a zinc alloy;
a first inorganic material containing a sulfate having a solubility lower than 5 g/100 mL with respect to water; and
a second inorganic material which is soluble in water, exhibits alkalinity if dissolved in water, and has a solubility lower than 5 g/100 mL with respect to water.
2 . The coating material according to claim 1 , wherein
the second inorganic material has a pH of 12 or less in a saturated aqueous solution.
3 . The coating material according to claim 1 or 2 , wherein
the second inorganic material is at least one of phosphate, carbonate, magnesium hydroxide, and magnesium oxide.
4 . The coating material according to any one of claims 1 to 3 , wherein
a mixing amount of the first inorganic material is 0.5 g or more with respect to 100 g of a heating residue of a coating film (excluding the first inorganic material and the second inorganic material which are mixed),
an amount of the second inorganic material to be mixed is 0.5 g or more with respect to 100 g of the heating residue of the coating film (excluding the first inorganic material and the second inorganic material which are mixed), and
a total mixing amount of the first inorganic material and the second inorganic material is 1 g to 32 g with respect to 100 g of the heating residue of the coating film (excluding the first inorganic material and the second inorganic material which are mixed).
5 . The coating material according to any one of claims 1 to 4 , wherein
the first inorganic material is composed of at least one of sodium sulfate and calcium sulfate.
6 . The coating material according to claim 5 , wherein
the second inorganic material is composed of a mixture of magnesium carbonate and magnesium hydroxide or basic magnesium carbonate, and
a sum of a content amount of the first inorganic material and a content amount of the second inorganic material is 1 to 32 g with respect to 100 g of the heating residue of the coating film (excluding the first inorganic material and the second inorganic material which are mixed).
7 . The coating material according to any one of claims 1 to 6 , wherein
the coating is any of
a coating film made of a zinc-rich primer containing at least one of zinc and a zinc alloy containing 70% or more of zinc,
a coating film made of a zinc-rich paint containing at least one of zinc or a zinc alloy containing 70% or more of zinc,
a coating film made of a zinc dust paint containing at least one of zinc or a zinc alloy containing 70% or more of zinc,
a hot-dip galvanized film, and
a zinc thermal spray coating.