Process for the preparation of cyclic esters and method for purification of the same
申请人:——
公开号:US20030191326A1
公开(公告)日:2003-10-09
The present invention provides a process for production of a cyclic ester by depolymerization of an aliphatic polyester. In the process, a mixture containing the aliphatic polyester and a specific polyalkylene glycol ether, which has a boiling point of 230-450° C. and a molecular weight of 150-450, is heated under normal or reduced pressure to a temperature at which depolymerization of the aliphatic polyester takes place. Then, a substantially homogeneous solution phase, consisting of the melt phase of the aliphatic polyester and the liquid phase of the polyalkylene glycol ether, is formed. Heating of the solution phase is continued to form the cyclic ester by depolymerization and distil out the cyclic ester together with the polyalkylene glycol ether, and then the cyclic ester is recovered from the distillate. The present invention also provides a process for purification of a crude cyclic ester by use of the specific polyalkylene glycol ether described above.
A process for catalytic production of diaryl carbonates by oxidative carbonylation of aromatic hydroxy compounds with carbon monoxide and oxygen achieves water removal during reaction by a process comprising the steps of: removing a liquid stream from an oxidative carbonylation reaction mixture in a reaction vessel, subjecting the liquid stream to reduced pressure, and returning at least a portion of dried liquid stream to the reaction vessel. Typical catalyst systems for oxidative carbonylation contain (A) at least one Group 8, 9, or 10 metal having an atomic number of at least 44 or a compound thereof; (B) at least one alkali metal salt; (C) at least one metal co-catalyst; (D) at least one activating organic solvent; and (E) optionally, at least one base.
Compositions containing esters of aromatic alkoxylated alcohols and fatty carboxylic acids
申请人:——
公开号:US20030161792A1
公开(公告)日:2003-08-28
A personal care or cosmetic product composition that includes from about 0.1% to about 99% of at least one ester of alkoxylated aromatic alcohol and fatty carboxylic acid, and from about 0.1% to 60% of at least one functional ingredient is provided. The functional ingredients in the composition may include active ingredients and additional ingredients. Especially suitable active ingredients are sunscreen active ingredients and antiperspirant active ingredients. Preferred compositions are sunscreen product formulations and antiperspirant products. In one preferred embodiment, the composition further includes at least one cyclomethicone compound present in the amount of from about 1% to 99% by weight of the composition. A method of improving the protection of human or animal skin or hair from radiation and a method of improving the protection of human or animal skin or hair from perspiration are also provided.
METHOD FOR PRODUCING a-HYDROXYCARBOXYLIC ACID DIMERIC CYCLIC ESTER
申请人:Kureha Corporation
公开号:US20190330175A1
公开(公告)日:2019-10-31
Provided is a method for producing a high purity α-hydroxycarboxylic acid dimeric cyclic ester while heavy-component formation from an α-hydroxycarboxylic acid oligomer is suppressed. An α-hydroxycarboxylic acid dimeric cyclic ester is obtained by performing a depolymerization reaction in the coexistence of an inorganic acid or an inorganic acid salt or a mixture thereof; and an organophosphorus compound.
In a method for producing a cyclic ester according to an embodiment of the present invention, a mixture (I) containing an aliphatic polyester, a specific polyalkylene glycol diether, and a sulfonic acid compound as a thermal stabilizer is prepared and heated in predetermined conditions to obtain a mixture (II) in a state of solution. Furthermore, heating of the mixture (II) is continued to distill, together with the polyalkylene glycol diether, a cyclic ester formed by the depolymerization reaction, and thus a distillate (III) is obtained. The cyclic ester is recovered from the distillate (III). At this time, a specific solubilizing agent is added to at least one of the mixture (I) or (II). In this production method, the sulfonic acid compound as the thermal stabilizer is contained in the mixtures (I) and (II) and the distillate (III).