Efficiency Glycol Stearate Synthesis Process

Pearlescent pigment can be widely used in the industry such as coating, plastic, cosmetic because of its decorating abilities. The application of fatty acid esters has been limited due to its special structure and properties. Its pearlescent effect could be weaken and even disappeared if suffering light, heat or strong shear force. In this paper, we attempt to synthesize the esters which could show a good pearlescent vision and also bear strong shear force. The mechanism of presenting pearlescent effect and its application were investigated. The main contents are as follows:1. Poly-glycol and fatty acid were selected for esterification which is well performed with acid catalyst. The cold-mix pearl agents were made by directly adding esters to the surfactant system. Bead stearic acid and glycol were selected according to the pearlescent effect and its appearance of the pearl agent. Phosphoric acid and p-toluence sulphonic acid were chosen as the complex acid catalyst. The conversion of the bead stearic acid can achieved to 90.57% when the dose of the catalyst is 0.4%.2. The condition of the esterification was studied in laboratory. The ratio of acid to glycol, reaction temperature and dose of acid catalyst, which have influence on the conversion of bead stearic acid, were discussed through uniform experiment. The linear equation was concluded by SPSS with regression method of stepwise. It can be present as follows: Y=75.954-10.609(XA-1.514)+0.381(XB-102.5)According to the result of the uniform experiment, single-factor experiment has been performed to analyze the influence of each factor which is not line related to the conversion of bead stearic acid. The optical condition has been reached. The parameters are as follows:the ratio of acid to glycol is 1:1.4(mol:mol), the dose of catalyst is 1.6%, the reaction temperature is 120℃, reaction for 3.Oh. Under this condition, the conversion of bead stearic acid can be reached to 92.50-93.10%, and the product presents a good appearance. 3. The method of dispersing nano-SiOx in glycol and its stabilization has been studied in laboratory. The stirring speed, dispersing time and the maximum dispersing quantity have been studied to get a stable state. The result demonstrates that the F degree of high shear dispersing emulsifier can be used to achieve 13.0% dispersing quantity when dispersing time is 300 s(line speed of shear is 24.3 m/s accordingly).4. The technology condition of the synthesis of esters which can bear strong shear force has been studied in laboratory. The dose of acid catalyst and nano-SiOx, reaction temperature and time, which have influence on the conversion of bead stearic acid, have been studied through orthogonal experiment. The range analysis of orthogonal test shows that the reaction temperature is the most important factor. The optical condition of synthesizing strong effect esters is as follows:the dose of acid catalyst and nano-SiOx is 1.6% and 2.0% respectively, the reaction temperature and time is 130℃and 4.0 h respectively. And under this condition, the conversion of bead stearic acid can be reached to 97.06-97.89%, and the product presents a good appearance.5. The SEM shows that the shape of crystallization of the stearic acid glycol esters has not changed. It also shows that larger crystal and reunion-shape exist when nano-SiOx was added to the esters. The TEM demonstrates that nano-SiOx with a size of 50-80 nm has dispersed in the pearl agents homogeneously. We found that nano-SiOx can link the plate-like crystal of the stearic acid glycol esters. So the stable structure can be exist when bearing strong shear force. And then the product can always presents a good pearlescent effect.6. Then the condition of crystallization was studied. The mechanism of presenting pearlescent effect was discussed. Many factors, such as quantity of esters, stirring speed, method of cooling and viscosity, could effect the pearlescent of the pearl agent. It also proved that esters which have been synthesized with nano-SiOx can bear strong shear force.7. The application of the pearl ester has been studied. We prepared the cold-mix pearl agents which present brilliance and silver pearlescent effect respectively.