Tetrakis(3-(3.5-di-t-butyl-4-hydroxyphenyl)propionyloxymethyl)methane having a novel crystal structure, process for its production and its use as an antioxidant

Claim 2

Tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxymethyl]methane characterized by a novel crystal structure such that the X-ray diffraction pattern obtained by X-ray analysis using Cu-K a rays shows a sharp peak at a diffraction angle 20 = 10.90°.

Claim 3

The compound according to claim 1 having the X-ray pattern shown in Figure 1.

Claim 4

The compound to accordint to claim 1 having a melting point of about 111 °C to about 118°C.

Claim 5

A process for producing tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxymethyl]-methane as claimed in claim 1, characterised by (a) transesterifying methyl or ethyl 3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate with pentaerythritol in the presence of 0.3 to 2 parts by weight, per 100 parts by weight of said propionate, of a compound of the formula wherein R, and R 2 each represent an alkyl group having 1 to 6 carbon atoms, (b) treating the resulting tetrakis[3,5-di-t-butyl-4-hydroxyphenyl)propionyloxymethyl] methane with an alkanol capable of forming a molecular adduct compound therewith to convert it into the corresponding molecular adduct compound, and (c) recrystallizing the molecular adduct compound from ethanol as a solvent.

Claim 6

A process according to claim 4 wherein the alkanol has 3 or 4 carbon atoms.

Claim 7

Use of the compound claimed in claim 1 as an antioxidant for polyolefins.