[EN] PROCESS FOR PRODUCING METHACRYLIC ACID OR METHACRYLIC ACID ESTERS<br/>[FR] PROCÉDÉ DE PRODUCTION D'ACIDE MÉTHACRYLIQUE OU D'ESTERS D'ACIDE MÉTHACRYLIQUE
申请人:ROEHM GMBH
公开号:WO2020030374A1
公开(公告)日:2020-02-13
The present invention relates to a process for producing methacrylic acid or methacrylic acid esters. The present invention is directed to a new process for the production of methacrylic acid or alkyl methacrylate starting from Acrolein, which is available from glycerol or propane.
NEAR-INFRARED ABSORBING DYE, OPTICAL FILTER, AND IMAGING DEVICE
申请人:AGC Inc.
公开号:US20210071004A1
公开(公告)日:2021-03-11
A near-infrared absorbing dye includes a compound represented by formula (A). Each of R
11
to R
14
is independently a hydrogen atom, a halogen atom, a hydroxyl group, or an alkyl, aryl or alaryl group. Each of pairs R
11
and R
12
, R
12
and R
13
, and R
13
and R
14
may combine with one another to form a monocyclic ring or a polycyclic ring in which from 2 to 4 rings are fused. Each of R
15
and R
16
is independently an alkyl or alaryl group. R
15
and R
16
may combine with one another to form a cyclohetero ring having from 5 to 10 members together with the nitrogen atom.
The present invention relates to monosubstituted oxalic acid amides of the general formula (I)
[A]+ [O-C(O)-C(O)-X]- (I)
wherein the meaning is for
[A]+ a cation made from an organic moiety A having a formally positively charged heteroatom selected from the group consisting of nitrogen, phosphorus and sulfur and
X is the group -NRaRb, wherein Ra and Rb are the same or different and are independently from each other hydrogen or a C1 to C30 organic residue with the proviso that at least one of Ra and Rb is a C1 to C30 organic residue.
The present invention relates to a process for producing methyl methacrylate, comprising the following steps:
A) producing methacrolein and
B) reacting the methacrolein obtained in step A) in an oxidative esterification reaction to give methyl methacrylate,
characterized in that the two steps A) and B) take place in a liquid phase at a pressure of from 2 to 100 bar, and step B) is carried out in the presence of a heterogeneous noble-metal-containing catalyst comprising metals and/or comprising metal oxides.
The present invention relates to an optimized process for the preparation of methacrolein. Methacrolein is used in chemical synthesis particularly as an intermediate for the preparation of methacrylic acid, methyl methacrylate or even active ingredients, fragrances or flavourings. In particular the present invention relates to the optimization of the process parameters by which, inter alia, a reduction of the content of harmful dimeric methacrolein in the end product may be achieved.