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US 8,569,540 B2Granted
Stabilization of dicarbonate diesters with protonic acids
AssigneeLANXESS Deutschland GmbH
InventorsSteffen Kahlert, Johannes Kaulen, Erasmus Vogl
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Abstract
By using protonic acids, diesters of dicarbonic acid may be stabilized against thermal and chemical decomposition over a relatively long period. Mixtures of diesters of dicarbonic acid and protonic acids are outstandingly suitable for preserving foods.
Claims7
A mixture for the stabilization of diesters of dicarbonic acid, comprising:
- at least one protonic acid in an amount of 0.01 to 100,000 ppm, based on the diesters of dicarbonic acid, wherein the protonic acid is selected from the group of an inorganic acid and derivatives thereof and an organic carboxylic acid, and
- one or more diesters of dicarbonic acid of the general formula (I)
- where
- R1 and R2 independently of one another are straight-chain or branched C1-C8-alkyl, cycloalkyl, C2-C8-alkenyl, C2-C8-alkynyl or benzyl,
- each of which said R1 and R2 is optionally monosubstituted to polysubstituted, identically or differently by halogen;
- nitro;
- cyano;
- C1-C6-alkoxy;
- dialkylamino;
- or are phenyl which is optionally monosubstituted to polysubstituted, identically or differently by halogen;
- nitro;
- cyano;
- alkyl;
- haloalkyl;
- alkoxy;
- haloalkoxy;
- acyl;
- acyloxy;
- alkoxycarbonyl;
- carboxyl,
- wherein said organic carboxylic acid is selected from the group consisting of saturated and monounsaturated or polyunsaturated aliphatic monocarboxylic acids, saturated or polyunsaturated aliphatic dicarboxylic and polycarboxylic acids and derivatives thereof, hydroxamic acids, hydroxycarboxylic acids, amino acids, and keto acids.
18 more elements
A method for the purification by distillation of diesters of dicarbonic acids, comprising:
- admixing one or more diesters of dicarbonic acids of the general formula
- where
- R1 and R2 independently of one another are straight-chain or branched C1-C8-alkyl, cycloalkyl, C2-C8-alkenyl, C2-C8-alkynyl or benzyl,
- each of which is optionally monosubstituted to polysubstituted, identically or differently by halogen;
- nitro;
- cyano;
- C1-C6-alkoxy;
- dialkylamino;
- or are phenyl which is optionally monosubstituted to polysubstituted, identically or differently by halogen;
- nitro;
- cyano;
- alkyl;
- haloalkyl;
- alkoxy;
- haloalkoxy;
- acyl;
- acyloxy;
- alkoxycarbonyl;
- carboxyl,
- with a protonic acid present in an amount of 0.01 to 100 000 ppm, based on the diesters of dicarbonic acid, thereby forming a mixture, and distilling the mixture,
- wherein the protonic acid is selected from the group of an inorganic acid and derivatives thereof and an organic carboxylic acid, and
- further wherein said organic carboxylic acid is selected from the group consisting of saturated and monounsaturated or polyunsaturated aliphatic monocarboxylic acids, saturated and monounsaturated or polyunsaturated aliphatic dicarboxylic and polycarboxylic acids and derivatives thereof, hydroxamic acids, hydroxycarboxylic acids, amino acids, and keto acids.
19 more elements
Dependencies are inferred from the claim text.