Patent ID: 11903380
Assignee: ARKEMA FRANCE
Field: Basic materials chemistry (Chemistry)
Classification: CPC A | IPC A

Claim 14:
15. A method of preparation of a mixture of compounds, the process comprising the following steps:
a) reaction of an initial mixture of POM and a formaldehyde source in the presence of an acid catalyst, wherein the initial mixture of POM is represented by the general formula R1—(OCH2)n—OR1′
wherein
R1 and R1′, identical or different, are selected from alkyls having 1 to 8 carbon atoms, and
n=1 to infinity;

b) optionally separation of the acid catalyst from the reaction mixture;
c) optionally neutralization of the reaction mixture;
d) evaporation of light POM fraction of general formula R—(OCH2)n—OR′ with n=1 and/or 2 when R and R′=methyl or with n=1 when R=ethyl and R′=methyl or ethyl;
e) distillation to remove heavy POM fraction of general formula R—(OCH2)n—OR′ with n>5 when R=methyl and R′=methyl or ethyl or with n>4 when R and R′=ethyl;
f) optionally recycling of the light POM fraction and/or heavy POM fraction in step a), and
wherein said prepared mixture of compounds, which is also of general formula R—(OCH2)n—OR′, has R, R′ of the prepared mixture of compounds being identical or different and chosen from methyl and/or ethyl for at least 90 mol % of the total R+R′, and the rest of R, R′ of the prepared mixture of compounds being identical or different alkyls chosen from among those having 3 to 8 carbons and representing less than 10% of the total R+R′, and provided that:
(i) when R=R′=methyl, the prepared mixture comprises 3 compounds with n=3 to 5 or 2 compounds with n=3 to 4, and the weight of these (i) compounds is at least 95% of the total weight of the mixture,
(ii) when R=R′=ethyl, the prepared mixture comprises 3 compounds with n=2 to 4 or 2 compounds with n=2 to 3, and the weight of these (ii) compounds is at least 95% of the total weight of the mixture, and
(iii) when R=methyl and R′=ethyl, the prepared mixture comprises 4 compounds with n=2 to 5 or 3 compounds with n=2 to 4, and the weight of these (iii) compounds represents at least 95%, of the total weight of the mixture.