摘要:
The addition of 3-mercaptopropionic acid or the organic ester thereof to the reaction mixture slows the rate of deactivation of cationic catalyst resins containing mercaptan promoter sites, during preparation of bisphenols by the condensation of a ketone with a phenol.
摘要:
Product quality productivity of continuous bisphenol-A (BPA) are increased by increasing the flow rate of reactants through the reactor and decreasing % acetone conversion in the presence of an ion exchange resin catalyst and an optional free mercaptan promoter.
摘要:
An integrated process for the preparation and recovery of BPA in pure form utilizes a series of steps to crystallize pure BPA of improved color stability and recycle separated impurities to improve overall yields. The principal impurity recycled to the process is o,p-BPA which functions as a color stabilizer in the product and in polycarbonate resins prepared from the BPA.
摘要:
In the preparation of bisphenol-A by condensation of phenol with acetone in the presence of an acidic ion-exchange resin catalyst, pretreatment of the catalyst to render it anhydrous comprises two steps to minimize resin degradation. In the first step, from 25 to 90 percent by weight of the resin associated water is removed by vaporization, and in the second step dehydration is completed by saturating the partially dehydrated catalyst with phenol. The advantage of the improvement in the process resides in a more efficient drying, requiring less time and minimal degradation of the resin structure.
摘要:
Product losses and color formation are sometimes encountered in the synthesis of bisphenol A from phenol and acetone in the presence of a cation exchange resin, particularly in the crude product stream from which bisphenol A has been separated via its phenol adduct. Such losses are suppressed and the crude product stream stabilized and decolorized by contact with an anion exchange resin.
摘要:
Acid contaminants leached from acidic ion-exchange resins and carried in process streams with phenol are separated from the phenol by passing the process stream in contact with an anionic exchange resin, whereby the acid contaminants react with and bond to the anionic exchange resin.
摘要:
A process comprising the addition of a degradation inhibiting effective amount of an ammonium, alkali metal, alkaline earth metal or transition metal of oxidation number +2 salt of an aliphatic mono or dicarboxylic acid to a composition comprising a phenol and a bisphenol, the addition occurring prior to a procedure which subjects the bisphenol to substantial heat, said bisphenol produced from an acidic ion exchange resin catalyzed reaction of a phenol and a ketone or aldehyde.
摘要:
Solvent-based processes for producing latent curing catalysts without causing an extreme exotherm. The process of the present invention includes combining an amine compound curing agent with a solvent, heating the mixture, adding an epoxy/solvent mixture via slow addition, removing the solvent and then heating the remaining composition. Following the heating, a phenolic resin is added to produce the final catalyst. The final catalyst comprises an amine compound, an epoxy, phenolic resin and a solvent. Catalysts having differing properties may be produced by varying the elements of the catalyst.
摘要:
An improvement in the continuous preparation of a bisphenol comprising maintaining the efficiency of the adduct crystallizer. The improvement comprises maintaining the Delta-T of the crystallizer at less than about 4.degree. C.
摘要:
A process for purifying phenol, phenol-type compounds, and substituted phenol and phenol-type compounds of contamination by components more acidic than the phenol component comprising treating a phenol containing process stream by contacting the stream with an amphoteric porous inorganic oxide.