Temporary antirust liquid for hot-rolled H-shaped steel
Technical Field
The invention relates to a temporary antirust liquid for hot-rolled H-shaped steel, belonging to the technical field of metal surface treatment.
Background
The hot-rolled H-shaped steel has excellent mechanical properties and is widely applied to the field of engineering and construction. If the hot-rolled H-shaped steel from the production line is not subjected to rust prevention treatment, the hot-rolled H-shaped steel can be rusted in the storage and transportation processes, so that the subsequent coating is influenced, and the mechanical property of the material can be seriously reduced. Antirust oil is generally used for temporary antirust treatment of hot-rolled H steel, but the antirust oil on the surface can affect the subsequent coating treatment, and the antirust oil needs to be removed when the antirust paint is used for coating.
Disclosure of Invention
Aiming at the problems of the prior hot-rolled H-shaped steel using antirust oil for temporary antirust treatment, the invention provides the hot-rolled H-shaped steel temporary antirust liquid, which overcomes the defect that after the antirust oil treatment, oil removal treatment is needed during subsequent coating treatment. Meanwhile, the temporary antirust liquid has the advantages of convenience in use, safety, environmental protection and the like.
In order to achieve the above object, the temporary rust preventive liquid for hot-rolled H-section steel of the present invention is prepared by the following method:
preparing a 5-20 wt% aqueous solution from a copolymer of unsaturated carboxylic acid and unsaturated carboxylic acid hydroxy ester, adding 2-10wt% gamma- (2, 3-epoxypropoxy) propyl trimethoxy silane into the aqueous solution, heating to 60 ℃, maintaining for 2 hours, cooling to room temperature, adding 0.2-2.0wt% of a flatting agent into the aqueous solution, and uniformly stirring to obtain the temporary antirust liquid for the hot-rolled H-shaped steel.
The leveling agent is any one of urea or n-butyl alcohol.
The unsaturated carboxylic acid is any one of acrylic acid or methacrylic acid; the unsaturated carboxylic hydroxyl ester is any one of 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate. The molecular weight of the copolymer of the unsaturated carboxylic acid and the unsaturated carboxylic acid hydroxy ester is 50000-500000. The molar ratio of the unsaturated carboxylic acid to the unsaturated carboxylic acid hydroxy ester in the copolymer is 9:1-5: 1.
The copolymer of the unsaturated carboxylic acid and the unsaturated carboxylic acid hydroxy ester is prepared by the following method:
adding 100kg of deionized water and 20kg of isopropanol into a reaction kettle in sequence, adding any one of the unsaturated carboxylic acids and any one of the unsaturated carboxylic acid hydroxy esters, adding 300g of ammonium persulfate, stirring for dissolving, heating to 80 ℃, maintaining the temperature in the kettle at 80-85 ℃ for reaction for 2 hours, cooling to 60 ℃, and decompressing and steaming out the isopropanol and water to obtain the unsaturated carboxylic acid and unsaturated carboxylic acid hydroxy ester copolymer.
The invention provides a temporary antirust liquid for hot-rolled H-shaped steel, which mainly comprises an aqueous solution of gamma- (2, 3-epoxypropoxy) propyl trimethoxy silane which is catalyzed and hydrolyzed by a copolymer of unsaturated carboxylic acid and unsaturated carboxylic acid hydroxy ester. Carboxyl in the copolymer can be complexed and crosslinked with iron ions on the surface of steel to form a protective film on the surface of the steel. The copolymer also contains hydroxyl which can be condensed with hydroxyl after silane hydrolysis, and a protective film is formed on the surface of silica gel generated after hydrolysis, so that the silica sol is prevented from further polymerizing and precipitating. The hot rolled section steel treated by the antirust liquid can be stored for 6-9 months without rusting in the open air. Meanwhile, the surface treated by the antirust liquid does not need to be cleaned in the subsequent coating process, and can be directly coated, so that the working procedures are simplified, and the cost is saved.
Detailed Description
Example 1
The copolymer of the unsaturated carboxylic acid and the unsaturated carboxylic acid hydroxy ester is prepared by the following method:
adding 100kg of deionized water and 20kg of isopropanol into a reaction kettle in sequence, adding any one of the unsaturated carboxylic acids and any one of the unsaturated carboxylic acid hydroxy esters, adding 300g of ammonium persulfate, stirring for dissolving, heating to 80 ℃, maintaining the temperature in the kettle at 80-85 ℃ for reaction for 2 hours, cooling to 60 ℃, and decompressing and steaming out the isopropanol and water to obtain the unsaturated carboxylic acid and unsaturated carboxylic acid hydroxy ester copolymer.
5kg of acrylic acid and 2-hydroxyethyl acrylate copolymer, wherein the molar ratio of acrylic acid to itaconic acid in the copolymer is 9:1, the molecular weight of the copolymer is 50000, and 100kg of deionized water is added; 2kg of gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane was added, heated to 60 ℃ for 2 hours, and cooled to room temperature to prepare a mixture of the copolymer and gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane. Adding 0.2kg of urea, and uniformly mixing to obtain the temporary antirust liquid for the hot-rolled H-shaped steel. The hot-rolled H-shaped steel treated by the method has no corrosion on the surface after being stored in the open air for 6 months.
Example 2
8kg of acrylic acid and 2-hydroxyethyl methacrylate copolymer, wherein the molar ratio of acrylic acid to itaconic acid in the copolymer is 9:1, the molecular weight of the copolymer is 50000, and 100kg of deionized water is added; 4kg of gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane was added, the mixture was heated to 60 ℃ for 2 hours, and the temperature was lowered to room temperature to prepare a mixture of the copolymer and gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane. And adding 0.4kg of n-butyl alcohol, and uniformly mixing to obtain the temporary antirust liquid for the hot-rolled H-shaped steel. The hot-rolled H-shaped steel treated by the method has no corrosion on the surface after being stored for 7 months in the open air.
Example 3
10kg of methacrylic acid and acrylic acid-2-hydroxyethyl ester copolymer, wherein the molar ratio of acrylic acid to itaconic acid in the copolymer is 8:1, the molecular weight of the copolymer is 200000, and 100kg of deionized water is added; 5kg of gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane was added, the mixture was heated to 60 ℃ for 2 hours, and then cooled to room temperature to prepare a mixture of the copolymer and gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane. Adding 1.0kg of urea, and uniformly mixing to obtain the temporary antirust liquid for the hot-rolled H-shaped steel. The hot-rolled H-shaped steel treated by the method has no corrosion on the surface after being stored in the open air for 8 months.
Example 4
15kg of methacrylic acid and 2-hydroxyethyl methacrylate copolymer, wherein the molar ratio of acrylic acid to itaconic acid in the copolymer is 6:1, the molecular weight of the copolymer is 400000, and 100kg of deionized water is added; 6kg of gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane was added, the mixture was heated to 60 ℃ for 2 hours, and then cooled to room temperature to prepare a mixture of the copolymer and gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane. And adding 1.0kg of n-butyl alcohol, and uniformly mixing to obtain the temporary antirust liquid for the hot-rolled H-shaped steel. The hot-rolled H-shaped steel treated by the method has no corrosion on the surface after being stored in the open air for 8 months.
Example 5
20kg of methacrylic acid and 2-hydroxyethyl acrylate copolymer, wherein the molar ratio of acrylic acid to itaconic acid in the copolymer is 8:1, the molecular weight of the copolymer is 500000, and 100kg of deionized water is added; 10kg of gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane was added, heated to 60 ℃ for 2 hours, and cooled to room temperature to prepare a mixture of the copolymer and gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane. And adding 2kg of urea, and uniformly mixing to obtain the temporary antirust liquid for the hot-rolled H-shaped steel. The hot-rolled H-shaped steel treated by the method has no corrosion on the surface after being stored in the open air for 9 months.
Example 6
20kg of acrylic acid and 2-hydroxyethyl methacrylate copolymer, wherein the molar ratio of acrylic acid to itaconic acid in the copolymer is 7:1, the molecular weight of the copolymer is 400000, and 100kg of deionized water is added; 8kg of gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane was added, the mixture was heated to 60 ℃ for 2 hours, and then cooled to room temperature to prepare a mixture of the copolymer and gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane. And adding 2kg of n-butyl alcohol, and uniformly mixing to obtain the temporary antirust liquid for the hot-rolled H-shaped steel. The hot-rolled H-shaped steel treated by the method has no corrosion on the surface after being stored in the open air for 9 months.