摘要:
The present invention relates to a process for the preparation of 3-acetoxy-2-methylbenzoyl chloride by reacting an alkali metal salt of 3-aminonaph-thalene-1,5-disulfonic acid with alkali metal hydroxide and water in the weight ratio 1:(1 to 1.6):(1 to 1.6) at 220 to 320.degree. C. to give the dialkali metal salt of the 3-hydroxy-2-methylbenzoic acid, separating off insoluble constituents from the reaction mixture, then adjusting the reaction mixture to a pH of 11.5 to 13.5 by addition of acid and reacting with acetic anhydride at -5 to +25.degree. C., precipitating the 3-acetoxy-2-methylbenzoic acid by addition of acid, separating off the 3-acetoxy-2-methylbenzoic acid and reacting it with an inorganic acid chloride to give 3-acetoxy-2-methylbenzoyl chloride.
摘要:
The invention relates to a process for the preparation of 3-hydroxy-2-methylbenzoic acid and 3-acetoxy-2-methylbenzoic acid, which comprises reacting 3-chloro-2-methylphenol (3) with benzyl chloride to give 2-benzyloxy-6-chlorotoluene (4) subjecting this to a Grignard reaction with magnesium to give (3-benzyloxy-2-methylphenyl)magnesium chloride (5) reacting this with CO.sub.2 to give 3-benzyloxy-2-methylbenzoic acid (6) hydrogenating this or its alkali metal salts in the presence of a hydrogenation catalyst to give 3-hydroxy-2-methylbenzoic acid (2) and optionally acetylating this to give 3-acetoxy-2-methylbenzoic acid.
摘要:
The invention relates to the use of polysilazanes as a permanent coating on metal and polymer surfaces for preventing corrosion, increasing scratch resistance and to facilitate easier cleaning. The invention comprises a solution of a polysilazane or a blend of polysilazanes of the general formula 1 —(SiR′R″—NR′″)n— (1) where R′, R″ and R′″ are identical or different and independently of one another represent hydrogen or an optionally substituted alkyl, aryl, vinyl or (trialkoxysilyl)alkyl group and n represents a whole number and is calculated in such a way that the polysilazane has a numerical average molecular weight of 150 to 150 000 g/mol, in a solvent. The invention also relates to a method for producing the coating.
摘要:
A coating for metals containing a polysilazane solution or a mixture of polysilazanes of general formula (1) —(SiR′R″—NR″)n— (1) wherein R′, R″, R″′ are identical or different and independently represent hydrogen or an optionally substituted alkyl-, aryl-, vinyl or (trialkoxysilyl)alkyl radical, wherein n is a whole number and n is dimensioned in such a way that polysilazane has an average molecular weight of 150-150,000 g/mol, in a solvent and at least one catalyst. The invention also relates to a method for the production of the coating.
摘要:
The invention concerns a process for the reduction of nitro groups to amino groups, characterized that a nitro compound is reacted with hydrogen in the presence of an aqueous solution of a water-soluble metal catalyst of the formula M (L).sub.n (Y).sub.m wherein M is ruthenium, rhodium, nickel, or palladium; L, is a water soluble ligand; Y is a further ligand or an alkaline earth ion; n is 1, 2, 3, or 4; and m is 0, 1, or 2.
摘要:
A coating for metals containing a polysilazane solution or a mixture of polysilazanes of the general formula (I) —(SiR′R″-NR′″)n— (1) wherein R′, R″ and R′″ are identical or different and independently represent hydrogen or an optionally substituted alkyl, aryl, vinyl or (trialkoxysilyl)alkyl radical, wherein n is a whole number and n is dimensioned in such a way that the polysilazane has a number-average molecular weight of 150 to 150 000 g/mol, in a solvent and at least one catalyst. The invention also relates to a method for the production of the coating.
摘要:
A method used to produce a permanent support layer on precious metal surfaces by coating solutions which are based on polysilazane. Said method is used to coat surfaces made of precious metal or precious metal alloys with a solution containing a polysilazane of formula (I), wherein n is measured in such a manner that the polysilazane has an average molecular weight from 150-150,000 g/mol, in addition to a solvent and a catalyst. The invention is characterized in that a silane based primer which contains sulphur and which is used to improve adherence, is applied to the object which is to be coated prior to the coating with the polysilazane solution. The invention also relates to coatings which are produced according to the inventive method.
摘要:
A coating solution comprising 0.1 to 35% by weight of an inorganic or organic polysilazane having repeating units represented by the general formula below and soluble in a solvent and 0.1 to 10% by weight of catalyst such as 4,4′-trimethylenebis(1-methylpiperidine) based on a pure polysilazane content. By applying the coating solution onto the surface of base materials such as metals, plastics, glass, ceramic, wood, cement, mortar, bricks, etc., a silica coating strongly adhered to the base materials can be formed excellent in corrosion resistance and anti-scratch properties and simultaneously excellent in characteristics such as abrasion resistant, long-lasting anti-fouling properties, wetting properties to water, sealing properties, chemical resistance, oxidation resistance, physical barrier effect, heat resistance, fire resistance and antistatic properties.
摘要:
The invention relates to the use of polysilazanes as permanent coatings on metal surfaces for the prevention of the susceptibility to fingerprints, characterized in that the polysilazane is in the form of a solution of a polysilazane or a mixture of polysilazanes of the general formula 1 —(SiR′R″—NR′″)n— (1) where R′, R″, R′″ independently=H, optionally-substituted alkyl-, aryl, vinyl- or (trialkoxysilyl)alkyl, n=a whole number such that the polysilazane has a number-average molecular weight of from 150 to 150,000 g/mol in a solvent. The invention further relates to a method for production of the coating.
摘要:
The invention relates to a surface coating comprising at least one type of perhydropolysilazane of the formula I wherein n is an integer of a value such that the perhydropolysilazane number-average molecular weight of from 150 to 150 000 g/mol, a solvent and a catalyst and, possibly one or more cobinding agents. The hardened coating has thickness of at least 1 micrometer, preferably ranging from 2 to 20 micrometers. The inventive coating containing at least one type of perhydropolysilazane is suitable for protecting rims, in particular, aluminum rims.