Process for preparing tetrakis [3-(3,5-dibutyl-4- hydroxyphenyl) propionyloxymethyl] methane

Claim 2

A process for preparing tetrakis [3-(3,5-dibutyl--4-hydroxyphenyl)propionyloxymethyl] methane, wherein an ester exchange reaction between a propionic acid ester having the general formula: wherein Bu is an n-, sec-, iso-, or tert-butyl group and is an alkyl group having 1 to 4 carbon atoms, and pentaerythritol in the presence of an alkaline catalyst is effected by adding 0.2 through 1.8 mol of water based on 1 mol of the alkaline catalyst by the substantial completion of the ester exchange reaction.

Claim 3

A process as claimed in claim 1 wherein the reaction temperature is 80°C through 140°C.

Claim 4

A process as claimed in claim 1 wherein the mol ratio of the pentaerythritol to the propionic acid ester is 1/4 through 1/5.

Claim 5

A process for preparing tetrakis [3-(3,5-dibutyl--4-hydroxyphenyl)propionyloxymethyl] methane, comprising the steps of: (A) reacting an alkyl acrylate having the general formula: CH2 = CH - COOR1 wherein R1 is an alkyl group having 1 to 4 carbon atoms, with 2,6-dibutylphenol in the presence of an alkaline catalyst, thereby forming a reaction product containing a propionic acid ester having the general formula: wherein Bu is an n-, sec-, iso-, or tert-butyl group and R1 is the same as defined above, and distilling off the unreacted starting materials from the reaction product; and (B) effecting an ester exchange reaction between the resultant reaction product and pentaerythritol by adding 0.2 through 1.8 mol of water based on 1 mol of the alkaline catalyst between the completion of the addition reaction of step (A) and the substantial completion of the ester exchange reaction.

Claim 6

A process for preparing tetrakis [3-(3,5-dibutyl--4-hydroxyphenyl)propionyloxymethyl] methane, comprising the steps of: (A) reacting an alkyl acrylate having the general formula: CH2 = CH - COOR1 wherein R1 is an alkyl group having 1 to 4 carbon atoms, with 2,6-dibutylphenol in the presence of an alkaline catalyst, thereby forming a reaction product containing a propionic acid ester having the general formula: wherein Bu is an n-, sec-, iso-, or tert-butyl group and R1 is the same as defined above, and distilling off the unreacted starting materials from the reaction product; and (B) effecting an ester exchange reaction between the resultant reaction product and pentaerythritol by adding 0.2 through 1.8 mol of water based on 1 mol of the alkaline catalyst between the completion of the addition reaction of step (A) and the substantial completion of the ester exchange reaction.

Claim 7

A process as claimed in claim 4 wherein the amount of the catalyst is 0.5% through 8.0% by weight based on 2,6-dibutylphenol.

Claim 8

A process as claimed in claim 4 wherein the reaction temperature of step (A) is 70°C through 100°C.

Claim 9

A process as claimed in claim 4 wherein the reaction temperature of step (B) is 80°C through 140°C.

Claim 10

A process as claimed in claim 4 wherein the mol ratio of the alkyl acrylate to the 2,6-dibutylphenol is 0.80 through 1.07.

Claim 11

A process as claimed in claim 4 wherein the mol ratio of the pentaerythritol to the propionic acid ester is 1/4 through 1/5.