RU97110784A

RU97110784A - METHOD OF INHIBITING PREMATURE POLYMERIZATION OF AROMATIC VINYL MONOMERS

Info

Publication number: RU97110784A
Application number: RU97110784/04A
Authority: RU
Inventors: Роланд Артур Эдвин Винтер; Ахн Волкер Хартмут Вон
Original assignee: Циба Спешиалти Чемикалс Холдинг Инк.
Priority date: 1994-11-28
Filing date: 1997-06-30
Publication date: 1999-05-20

Claims

1. A composition comprising
(a) aromatic compound of vinyl and
(b) an effective inhibitory amount sufficient to prevent premature polymerization during distillation or purification of the specified aromatic compound of vinyl, a stable compound of hindered nitroxyl used together with an effective amount of oxygen or air to increase the inhibitory activity of the nitroxyl compound.

2. The composition according to p. 1, characterized in that an effective amount of nitroxyl compound is, for example, from 1 to 2000 ppm (ppm), based on the mass of component (a).

3. The composition according to p. 2, characterized in that the effective amount of nitroxyl compound is, for example, from 5 to 1000 ppm, based on the weight of the component (a).

4. The composition according to claim 1, characterized in that an effective amount of oxygen or air is, for example, an approximate range from 10 to 1000 ppm, based on the mass of component (a).

5. The composition of claim 1, wherein the aromatic compound of vinyl in component (a) is selected from the group consisting of styrene, α-methylstyrene, vinyltoluene, divinylbenzene, styrene-sulfonic acid, and structural isomers, derivatives of these compounds, and mixtures thereof.

6. The composition according to claim 1, wherein the aromatic compound of vinyl is styrene, α-methylstyrene, vinyltoluene, or divinylbenzene.

7. The composition according to p. 1, characterized in that the stable obstructed nitroxyl compound of component (b) is selected from the group consisting of
di-tert-butyl nitroxyl,
1-oxyl-2,2,6,6-tetramethylpiperidine,
1-oxyl-2,2,6,6-tetramethylpiperidin-4-ol,
1-oxyl-2,2,6,6-tetramethylpiperidin-4-one,
1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl-acetate,
1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl-propionate,
1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl-2-ethylhexanoate,
1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl-stearate,
1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl-benzoate,
1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl-4-tert-butyl benzoate,
bis (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) succinate,
bis (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) -adipate,
bis (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) -sebactate,
bis (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) -n-butylmalonate,
bis (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) -phthalate,
bis (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) -isophthalate,
bis (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) -terephthalate,
bis (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) -hexahydroterephthalate,
N, N'-bis (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) -adipamide,
N- (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) caprolactam,
N- (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) -dodecylsuccinimide,
2,4,6-tris- (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) isocyanurate,
2,4,6-tris- [N-butyl-N-1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl] - sec-triazine or
4,4'-ethylenebis (1-oxyl-2,2,6,6-tetramethylpiperidin-3-one).

8. The composition according to p. 1, characterized in that it further contains a solvent or a dissolved polymer.

9. The composition according to p. 8, characterized in that the solvent is ethylbenzene or the dissolved polymer is a saturated or unsaturated polyester.

10. Method of inhibiting the premature polymerization of an aromatic vinyl compound during distillation or purification, in which an effective inhibitory amount sufficient to prevent premature polymerization during the distillation or purification of said aromatic vinyl compound, a stable nitroxyl compound used with an effective amount of oxygen or air to increase the inhibitory activity of nitroxyl compounds.

11. The method according to p. 10, characterized in that the aromatic compound of vinyl is distilled or purified at a temperature of from 50 ^o C to 150 ^o C.

12. The method according to p. 10, characterized in that the stable nitroxyl compound is added to the aromatic compound of vinyl continuously or intermittently in a place located above the point where distillation or purification takes place.

13. The method according to p. 10, characterized in that the stable nitroxyl compound is added at various points of entry into the process vapor of the aromatic compound of vinyl before the point where distillation or purification takes place.

14. The method according to p. 10, characterized in that the amount of stable nitroxyl compound is from 1 to 2000 ppm (ppm), based on the mass of the aromatic compound of vinyl.

15. The method according to p. 10, characterized in that its implementation begins under anaerobic conditions, followed by continuous or intermittent addition of oxygen or air.

16. The method according to p. 10, characterized in that it is carried out in anaerobic conditions.

17. The method according to p. 10, characterized in that the oxygen is added to the aromatic compound of vinyl intermittently in order to extend the time of inhibition of polymerization or slow down the polymerization that has begun.