Aluminum Container Containing Dicarbonate

Abstract

The invention relates to aluminium vessels containing dicarbonic diesters and to a method for producing the packaged dicarbonic diesters.

Claims

1-15. (canceled)

16. An aluminium vessel containing therein a product, wherein the product comprises at least one compound of the formula (I) ##STR00003## in which R.sub.1 and R.sub.2 independently of one another are straight-chain or branched C.sub.1-C.sub.8 alkyl, cycloalkyl, C.sub.2-C.sub.8 alkenyl, C.sub.2-C.sub.8 alkynyl or benzyl, wherein in each case R.sub.1 and R.sub.2 is optionally substituted one or more times by identical or different halogen, nitro, cyano, C.sub.1-C.sub.8 alkoxy and/or dialkylamino substituents; or are phenyl which is optionally substituted one or more times by identical or different halogen, nitro, cyano, alkyl, haloalkyl, alkoxy, haloalkoxy, acyl, acyloxy, alkoxycarbonyl and/or carboxyl substituents, and the aluminium vessel has an inside and said inside is coated with at least one polymer thereby forming a polymer layer.

17. The aluminium vessel according to claim 16, wherein R.sup.1 and R.sup.2 independently of one another are straight-chain or branched C.sub.1-C.sub.8 alkyl, C.sub.2-C.sub.8 alkenyl, phenyl or benzyl.

18. The aluminium vessel according to claim 16, wherein the compounds of the formula (I) are dimethyl dicarbonate,diethyl dicarbonate, or mixtures thereof.

19. The aluminium vessel according to claim 16, wherein the compounds of the formula (I) fill the vessel in an amount of 90 to 100%, based on the total amount of product filling the vessel.

20. The aluminium vessel according to claim 16, wherein the polymer is selected from the group of polyesters, phenolic resins, acrylic resins, amino resins, epoxy resins and mixtures of thereof.

21. The aluminium vessel according to claim 16, wherein the amount of fillers and/or pigments is less than or equal to 50 ppm in the polymer coating.

22. The aluminium vessel according to claim 16, wherein the thickness of the polymer layer is 5 to 10 m.

23. The aluminium vessel according to claim 16, wherein the polymer is a polyester having an average molecular weight (MW) of 1000 to 7500 g/mol.

24. The aluminium vessel according to claim 16, wherein the polymer is a polyester having a glass transition temperature of less than or equal to 100 C.

25. The aluminium vessel according to claim 16, wherein the polymer is a polyester which has been prepared from at least a pyromellitic dianhydride, a tricyclodecanedimethanol and a crosslinker comprising isophorone diisocyanate.

26. A method for producing the aluminium vessel according to claim 16, comprising the steps of: a.) the inside of the aluminium vessel is coated with a polymer composition, and to form a non-cured inside polymer layer, b.) the non-cured inside-polymer layer is cured thereby forming said polymer layer, and c.) the product, optionally under inert gas, is filled into the aluminium vessel.

27. The method according to claim 26, wherein the polymer composition in step a.) is a mixture comprising 20 wt % to 75 wt % of polyesters, 10 wt % to 79 wt % of organic solvents and 0.9 wt % to 25 wt % of phenolic resins and 0.1 to 2 wt % of lubricants, and less than 5 ppm of fillers and/or pigments.

28. The method according to claim 27, wherein the polymer composition in step a.) is applied by spraying.

29. The method according to claim 26, wherein step b.) is in the presence of heating at a temperature of 150 C. to 280 C.

Description

Examples

Example 1

Production of the Coated Aluminium Vessel

[0079] A polyester resin varnish (Goldlack BT651B (from Valspar Corp.)) was applied by spraying to the aluminium surface, more particularly to the surface facing the filled product. The vessel was then heated at 190 C. for 10 min. Thereafter the uniformity of the coating was examined optically.

Example 2

Filling of the Aluminium Vessel With Dimethyl Dicarbonate

[0080] The coated aluminium bottles from Example 1 are filled with dimethyl dicarbonate and sealed directly with a plastic cap from Bericap, Budenheim. The caps have a polytetrafluoroethylene (PTFE) seal. The seal is available commercially under the name Plytrax 100 and was obtained from Norton Performance Plastic Corporation, Wayne, N.J., USA.

Example 3

Stability Tests of Dimethyl Dicarbonate In Different Containers

[0081] 3 kg of dimethyl dicarbonate were filled into different containers, available commercially and produced experimentally, as listed in Table 1, and the containers were then sealed and placed for storage into various temperature cabinets. The conditions, in other words the storage time and the storage temperature, under which the filled product was stored in the containers can be seen from Table 1. Analysis was carried out by gas chromatography; in this case, a determination was made of the amount of dimethyl carbonate present, which is a breakdown product in the thermal decomposition of dimethyl dicarbonate. Where a high quantity of dimethyl carbonate is found, this is representative of a low stability of the dimethyl dicarbonate.

TABLE-US-00001 TABLE 1 Storage temperature Dimethyl carbonate content [ C.] [ppm]/after X days' storage Aluminium, uncoated 20 6724 ppm/35 days (from Leicht und Appelt, Bad Gandersheim, GER) Aluminium anodized (from 20 4462 ppm/35 days Leicht und Appelt, Bad Gandersheim, GER) Glass 20/40/20* 19 591 ppm/168 days Polyester resin varnish, 20/40/20* 120 ppm/365 days coated on aluminium, with a pigment content of less than 300 ppm. (Goldlack BT651B (from Valspar Corp. AG, Grningen, CH) Polyester resin varnish 20/40/20* 840 ppm/365 days coated on aluminium, with a pigment content of less than 300 ppm. (Goldlack 32S23MC (from Valspar Corp. AG, Grningen, CH) *5 weeks' storage at 20 C., then 4 weeks at 40 C., then continued storage at 20 C.

[0082] As can be seen from Table 1, dimethyl dicarbonate can be stored for much longer, and hence more stably, in aluminium vessels coated with polyester varnish than in uncoated or anodized aluminium vessels.