PRODUCTION OF TERT-BUTYL ESTERS OF ETHYLENICALLY UNSATURATED CARBOXYLIC ACIDS
申请人:BASF SE
公开号:US20190002389A1
公开(公告)日:2019-01-03
A process for continuously preparing the tert-butyl ester of an ethylenically unsaturated carboxylic acid, by a) reacting an ethylenically unsaturated carboxylic acid with isobutene in the presence of an acidic catalyst to give an esterification mixture; b) removing the acidic catalyst; c) removing low-boiling components; and d) supplying a tert-butyl ester-comprising liquid to a distillation apparatus and subjecting it to purifying distillation in the distillation apparatus, where
d
1
) in the distillation apparatus the tert-butyl ester-comprising liquid is separated into a tert-butyl ester-comprising gaseous top product and a carboxylic acid-comprising liquid bottom product;
d
2
) the tert-butyl ester-comprising gaseous top product is at least partly condensed and the condensate is recycled partly as reflux to the distillation apparatus;
d
3
) the carboxylic acid-comprising liquid bottom product is recycled at least partly to step a);
d
4
) carboxylic acid-comprising liquid bottom product is drawn off and passed to a heater; a superheated, liquid recycle stream is taken from the heater; and the superheated recycle stream is let down into the distillatiuon apparatus; and
d
5
) at least in the top region of the distillation apparatus, the distillation apparatus walls in contact with the vapor, at least in sub-regions, are heated and/or thermally insulated. In the course of the process, the separation of the tert-butyl ester from unreacted carboxylic acid is carried on with a particularly low level of accompanying polymerization both of the tert-butyl ester and of the carboxylic acid.
Polymerization inhibitor composition for vinyl aromatic compounds
申请人:UNIROYAL CHEMICAL COMPANY, Inc.
公开号:EP0325059A2
公开(公告)日:1989-07-26
Vinyl aromatic compounds are stabilized against polymerization by the addition of an effective amount of a polymerization inhibition composition comprising (a) a phenothiazine compound; and (b) an aryl-substituted phenylenediamine compound. In other aspects, this invention is directed to a vinyl aromatic composition stabilized against polymerization by such polymerication inhibitor composition, as well as to a method of stabilizing a vinyl aromatic composition against polymerization which method comprises adding an effective amount of such polymerization inhibitor composition.
Vinyl aromatic compositons stabilized against polymerization
申请人:UNIROYAL CHEMICAL COMPANY, Inc.
公开号:EP0334500A1
公开(公告)日:1989-09-27
Vinyl aromatic compounds are stabilized against polymerization by the addition of an effective amount of a polymerization inhibition composition comprising (a) a phenothiazine compound; and (b) an aryl-substituted phenylenediamine compound. In other aspects, this invention is directed to a vinyl aromatic composition stabilized against polymerization by such polymerication inhibitor composition, as well as to a method of stabilizing a vinyl aromatic composition against polymerization which method comprises adding an effective amount of such polymerization inhibitor composition.
Polymerization inhibitors for acrylic acids and esters
申请人:UNIROYAL CHEMICAL COMPANY, Inc.
公开号:EP0522709A2
公开(公告)日:1993-01-13
This invention is directed to certain N,N'-dinitroso phenylenediamines useful as polymerization inhibitors for acrylic acids and esters thereof. Also disclosed are compositions containing such compounds, and methods for inhibiting polymerization using such compounds and compositions.
Preparation of tert-butyl esters of aliphatic carboxylic acids
申请人:BASF SE
公开号:US10023520B2
公开(公告)日:2018-07-17
A process for continuously preparing the tert-butyl ester of an aliphatic C1-C4 carboxylic acid comprises: a) the reaction of an aliphatic C1-C4 carboxylic acid with isobutene in the presence of an acidic catalyst to give an esterification mixture (G1); b) the partial evaporation of the esterification mixture (G1), giving a liquid first high boiler phase (SPh1) comprising the acidic catalyst, and a first vapor (B1) comprising tert-butyl ester; c) the fractional condensation of the first vapor (B1) by partially condensing the first vapor (B1) at a first pressure and a first temperature and obtaining a first condensate (K1), partially condensing the uncondensed second vapor (B2) at a second pressure and a second temperature and obtaining a second condensate (K2), the first temperature being 0 to 45° C. below the condensation temperature of the tert-butyl ester at the first pressure and the second temperature being 45 to 80° C. below the condensation temperature of the tert-butyl ester at the second pressure, with the proviso that the second temperature is at least 5° C. below the first temperature; and d) the combination of the first condensate (K1) and the second condensate (K2) and the feeding to a combined workup, and recycling of the third vapor (B3) not condensed at the second temperature into step a). The process allows the preparation of the tert-butyl ester of an aliphatic C1-C4 carboxylic acid by reaction of the carboxylic acid with isobutene, with isolation of unconverted isobutene from the esterification mixture in an energetically favorable manner and with an improved degree of removal.