Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C68/00—Preparation of esters of carbonic or haloformic acids
  • C07C68/06—Preparation of esters of carbonic or haloformic acids from organic carbonates
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C68/00—Preparation of esters of carbonic or haloformic acids
  • C07C68/08—Purification; Separation; Stabilisation

Definitions

• the invention is in the field of cosmetics and relates to a process for the production of oil bodies of the dialkyl carbonate type, in which products with improved odor properties are obtained.
• Dialkyl carbonates are interesting new oil bodies for cosmetics and are usually produced by transesterification of dimethyl or diethyl carbonate with longer-chain fatty alcohols.
• the production and use of dioctyl carbonate which is commercially available under the INCI name dicaprylyl carbonate and the brand Cetiol® CC (Cognis Deutschland GmbH), are particularly preferred [cf. WO 97/47583 (Cognis)].
• the disadvantage is that the carbonates have a sweaty odor, so that they must be perfumed when used in cosmetics. A usual steam deodorization for these cases has proven unsuccessful.
• the object of the present invention was therefore to provide dialkyl carbonates which have an improved odor quality compared to the prior art, in order to facilitate their use in cosmetics in this way.
• the invention relates to a process for the preparation of dialkyl carbonates of the formula (I),
• R 1 and R 2 independently of one another are linear or branched hydrocarbon radicals having 6 to 22 carbon atoms and 0 or 1 to 3 double bonds, by transesterification of C 1 -C 4 -dialkyl carbonates with C ⁇ -C ⁇ alcohols, in which
• the invention is based on the knowledge that the olfactory impairment of the dialkyl carbonates is due to very different impurities which can only be removed by different process measures. Surprisingly, it was found that the combination of two rectification and one deodorization step finally delivers a product that has a perfect odor and can be used in cosmetics without additional perfuming.
• the unwanted low-boiling low-boiling impurities are separated off in the first step.
• the bottom product is then subjected to a second rectification, in which the high-boiling impurities are left in the bottom and only the distillate is used further.
• the rectification itself is carried out in particular in columns with structured packings which preferably have a pressure loss of less than 1-2 mbar / m.
• the first rectification is carried out at temperatures (sump) in the range from 180 to 250 ° C. and a reduced pressure (head) from 0.01 to 10 mbar, preferably at temperatures (sump) from 180 to 200 ° C. and a reduced pressure ( Head) from 1 to 10 mbar.
• the second rectification usually takes place at temperatures (bottom) of 150 to 250 ° C and a reduced pressure (head) of 0.01 to 0.5 mbar, preferably at temperatures (bottom) of 150 to 180 ° C and a reduced pressure ( Head) from 0.01 to 0.5 mbar.
• the deodorization is generally carried out in a column at a reduced pressure of 10 to 100 mbar using steam or inert gases, preferably nitrogen. example
• the processing of a technical dioctyl carbonate was carried out in two material-coupled rectification columns, each with a 0.5 m EX pack from Sulzer AG, and a deodorization column.
• the column diameters were 30 mm.
• the crude transesterification mixture was evaporated on a combination of thin-layer and falling-film evaporator, and applied to the first rectification column, the head pressure 5 mbar, the bottom temperature 185 C ⁇ , the pressure loss was about 9 mbar and the reflux ratio. 5 43.5% by weight of low-boiling distillate and 56.5% by weight of valuable product were obtained in the bottom.
• the bottom product was then evaporated in the same way and fed to the second rectification column, the top pressure being 0.1 mbar, the bottom temperature 176 ° C., the pressure drop about 9 mbar and the reflux ratio being 3.
• the subsequent deodorization was carried out at 100 ° C. in a separate column with nitrogen. A product was obtained which proved to be completely odorless even after 6 months of storage.
• Figure 1 shows a flow diagram of the process.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Fats And Perfumes (AREA)
• Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=7696063

Family Applications (1)

Country Status (6)

Families Citing this family (6)

Citations (3)

Family Cites Families (33)

• 2001
  • 2001-08-21 DE DE10140846A patent/DE10140846A1/de not_active Withdrawn
• 2002
  • 2002-08-13 DE DE50209022T patent/DE50209022D1/de not_active Expired - Lifetime
  • 2002-08-13 ES ES02796225T patent/ES2278999T3/es not_active Expired - Lifetime
  • 2002-08-13 WO PCT/EP2002/009042 patent/WO2003018527A1/de not_active Ceased
  • 2002-08-13 EP EP02796225A patent/EP1419133B1/de not_active Expired - Lifetime
  • 2002-08-13 JP JP2003523192A patent/JP4274938B2/ja not_active Expired - Lifetime
  • 2002-08-13 US US10/487,615 patent/US7094917B2/en not_active Expired - Lifetime

Patent Citations (3)

Also Published As

Similar Documents

Legal Events