Abstract: Propylene glycol monomethyl ether butyrates and their isomers are obtained by the esterification of propylene glycol monomethyl ether or its isomer with iso-butyric or n-butyric acid at an elevated temperature above 80.degree. C. in the presence of acidic catalyst and azeotropic agent. These compounds are rectified for removing acid residue and moisture in order to yield the desirable product having high purity.

Abstract: Propylene glycol monomethyl ether propionate compounds are obtained by the esterification of propylene glycol monomethyl ether with propionic acid at an elevated temperature above 80.degree. C. in the presence of acidic catalyst and azeotropic agent. The compounds are rectified for removing acid residue and moisture in order to yield the desirable product having high purity.

Abstract: A propylene glycol monomethyl ether propionate compound is obtained by the esterification of propylene glycol monomethyl ether with propionic acid at an elevated temperature above 80 .degree.C. in the presence of acidic catalyst and azeotropic agent. This compound is rectified for removing acid residue and moisture in order to yield the desirable product having high purity.

Abstract: A novel thermosetting resin, the thermoset resin obtained therefrom having such a thermal resistance that the temperature at which the thermoset resin is caused to show a weight loss of 6% by heating at a temperature elevation rate of 10.degree. C. per minute is at least 400.degree. C., is prepared by reacting a specific phenolic resin with a member selected from the group consisting of a silicic acid ester of the formula Si(OR).sub.4 wherein R represents alkyl or aryl and a mixture of a silicic acid ester of the formula as defined above and a titanic acid ester of the formula Ti(OR).sub.4 wherein R has the same meaning as defined above in the presence of an alkaline catalyst while keeping the reaction system in a molten state, to an extent that 20- 70 mole %, based on the phenol present in the starting system to be reacted with said member, of phenolic hydroxyl groups in terms of the amount of phenol, remain unreacted.

Abstract: A novel thermosetting resin, the thermoset resin obtained therefrom having such a thermal resistance that the temperature at which the thermoset resin is caused to show a weight loss of 6% by heating at a temperature elevation rate of 10.degree.C. per minute is at least 400.degree.C., is prepared by reacting a specific phenolic resin with a member selected from the group consisting of a silicic acid ester of the formula Si(OR).sub.4 wherein R represents alkyl or aryl, a titanic acid ester of the formula Ti(OR).sub.4 wherein R has the same meaning as defined above and a mixture thereof in the presence of an alkaline catalyst while keeping the reaction system in a molten state, to an extent that 20 - 70 mole %, based on the phenol present in the starting system to be reacted with said member, of phenolic hydroxyl groups in terms of the amount of phenol, remain unreacted.