Patent GB-969302-A (GB)
Title: Improvements in or relating to compositions and processes for the protection of metals
IPC: C23F11/16
Filed: 1963-02-26
Abstract: A composition for use in inhibiting the corrosion of metals (such as ferrous metals, Cu and Cu alloys) by corrosive aqueous media comprises between 20 and 80 parts by weight of an alkali metal salt (e.g. a Na or K salt) of 2-mercaptobenzothiazole and between 80 and 20 parts by weight of an N,N-dimethyl amide of at least one straight chained aliphatic carboxylic acid containing 18 carbon atoms and having at least one carbon to carbon double bond and the total of the parts by weight of the alkali metal salt and of the amide being 100. Examples of the acids are oleic, linoleic, linolenic and ricinoleic. Suitable mixtures of acids are found in tall, castor, corn, cottonseed, linseed, olive, peanut, rapeseed, safflower, sesame and soybean oils.  The inhibitor may be added to the corrosive aqueous medium and be used in protecting Cu alloy wire cloths of Fourdrinier paper making machines and in protecting steel oil-well equipment.  In protecting the wire cloths in paper making machines, the inhibitor may be added to the mass of paper pulp and water or to a water shower system. The cloths may be coated with the inhibitor to protect them during storage.  Suitable inhibitor solvents are water, glycols, aliphatic alcohols, ketones, and glycol ethers. Specific examples are given.  The total amount of inhibitor used in an aqueous medium is at least 0.5 p.p.m. Reference is made to the following corrosive agents: chlorides, sulphates, sulphites, bisulphites, O2, H2S, CO2 and Cl2. U.S.A. Specification 2,839,467 is referred to.ALSO:Copper alloy wire cloths of Fourdrinier paper making machines are coated with a corrosion inhibitor composition.  The composition comprises between 20 and 80 parts by weight of an alkali metal salt (e.g. a Na or K salt) of 2-mercaptobenzothiazole and between 80 and 20 parts by weight of an N,N-dimethyl amide of at least one straight chained aliphatic carboxylic acid containing 18 carbon atoms and having at least one carbon to carbon double bond and the total of the parts by weight of the alkali metal salt and of the amide being 100.  Examples of the acids are oleic, linoleic, linolenic and ricinoleic.  Suitable mixtures of acids are found in tall, castor, corn, cottonseed, linseed, olive, peanut, rapeseed, safflower, sesame and soybean oils. In protecting the wire cloths in paper making machines, the inhibitor may be added to the mass of paper pulp and water or to a water shower system.  The cloths may be coated with the inhibitor to protect them during storage.  Suitable inhibitor solvents are water, glycols, aliphatic alcohols, ketones, and glycol ethers. Specific examples are given.  The total amount of inhibitor used in an aqueous medium is at least 0,5 p.p.m.  Reference is made to the following corrosive agents: chlorides, sulphates, sulphites, bisulphites, O2, H2S, CO2 and Cl2.  U.S.A. Specification 2,839,467 is referred to.ALSO:In Fourdrinier paper making machines, copper alloy wire cloths are treated with a corrosion inhibitor composition.  The composition comprises between 20 and 80 parts by weight of an alkali metal salt (e.g. a Na or K salt) of 2-mercaptobenzothiazole and between 80 and 20 parts by weight of an N,N-dimethyl amide of at least one straight chained aliphatic carboxylic acid containg 18 carbon atoms and having at least one carbon to carbon double bond and the total of the parts by weight of the alkali metal salt and of the amide being 100. Examples of the acids are oleic, linoleic, linolenic and ricinoleic. Suitable mixtures of acids are found in tall, castor, corn, cottonseed, linseed, olive, peanut, rapeseed, safflower, sesame and soybean oils.  In protecting the wire cloths in paper making machines, the inhibitor may be added to the mass of paper pulp and water or to a water shower system.  The cloths may be coated with the inhibitor to protect them during storage.  Suitable inhibitor solvents are water, glycols, aliphatic alcohols, ketones, and glycol ethers. Specific examples are given.  The total amount of inhibitor used in an aqueous medium is at least 0.5 p.p.m.  Reference is made to the following corrosive agents:- chlorides, sulphates, sulphites, bisulphites, O2, H2S, CO2 and Cl2. U.S.A. Specification 2,839,467 is referred to.