Process for producing optical molding materials

A method for producing a transparent or colored article, the method comprising:

• molding an alkyl methacrylate resin comprising an alkyl methacrylate into a transparent or colored article, wherein when the article is transparent, it is selected from at least one article selected from the group consisting of an optically conductive sheet, a headlight lens, a headlight cover, a cover for a light source, a display cover, a noise barrier, and a construction material for a greenhouse,
• wherein the alkyl methacrylate is produced by a process comprising:
• a. producing methacrolein in a reactor I,
• b. oxidatively esterifying the methacrolein in the presence of an alcohol, oxygen, and a heterogeneous noble metal-containing catalyst, at a water content between 0.1% and 10% by weight and a pH between 5 and 8 in at least one reactor II, to obtain a reactor output,
• c. after-treating the reactor output from the at least one reactor II in a reactor to obtain a crude alkyl methacrylate, and
• d. isolating and purifying the crude alkyl methacrylate from the reactor III,
• wherein the alkyl methacrylate comprises dimethoxyisobutene (DMIB) and methyl isobutyrate, and has a DMIB content of less than 300 ppm and a methyl isobutyrate content of less than 600 ppm, and
• wherein in process step c, in the reactor III, a water content is at least 0.5% by weight higher than in the at least one reactor II.