US4683326A
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Solvent-free crystallization of pentaerythritol tetrakis-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and the novel alpha-crystalline form thereof
Assignee: BASF Corp
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Filing: 1986-07-10
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Granted: 1987-07-28
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Expires: 2006-07-10
Abstract
Abstract Seeding a melt of pentaerythritol tetrakis-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] with a small amount of the crystalline β-, δ- or λ-modification of this compound in an extruder, kneader or internal mixer at 70°-130° C. gives, within a few minutes, pure crystalline product without the use of a hitherto mandatory and environmentally undesirable solvent. Also described is a novel crystalline thermostable λ-modification of pentaerythritol tetrakis-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].
Inventors
- 👤 Ivan Orban
- 👤 Werner Fussenegger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:12
CPC Classifications
C; C07; C07C; C07C67/00; C07C67/48; C07C67/52; C07C69/00; C07C69/66; C07C69/73; C07C69/732
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
60 words
A process for the complete, solvent-free crystallisation of pentaerythritol tetrakis-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], which comprises seeding a melt of this compound in an extruder, a kneader or an internal mixer with at least 0.1 to 5% by weight, based on said melt, of the β-, δ- or λ-crystal modification of said compound, at a temperature in the range from 70° to 130° C.
Claim 2
Dependent Claim
60 words
A process for the complete, solvent-free crystallisation of pentaerythritol tetrakis-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], which comprises seeding a melt of this compound in an extruder, a kneader or an internal mixer with at least 0.1 to 5% by weight, based on said melt, of the β-, δ- or λ-crystal modification of said compound, at a temperature in the range from 70° to 130° C.
Claim 3
Dependent Claim
24 words
A process according to claim 1, which comprises using the melt obtained direct from the transesterification of methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate with pentaerythritol as crystallisation melt.
Claim 4
Dependent Claim
13 words
A process according to claim 1 which is carried out in an extruder.
Claim 5
Dependent Claim
11 words
A process according to claim 3 which is carried out continuously.
Claim 6
Dependent Claim
16 words
A process according to claim 1, wherein the melt is seeded with crystals of the λ-modification.
Claim 7
Dependent Claim
30 words
A process according to claim 1, wherein the seed crystals are used in an amount of 0.1 to 2, preferably of 0.8 to 1.2% by weight, based on the melt.
Claim 8
Dependent Claim
40 words
A process according to claim 1, which comprises seeding the melt obtained from the transesterification of methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate with pentaerythritol at 70°-130° C. with 0.5 to 5% by weight, based on the melt, of the λ-crystal modification of pentaerythritol tetrakis-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].
Claim 9
Dependent Claim
29 words
A process according to claim 1, wherein crystallisation is carried out at a temperature in the range from 70° C. to the melt temperature of the respective seed crystals.
Claim 10
Dependent Claim
18 words
A process according to claim 8, wherein crystallisation is carried out in the temperature range from 90°-110° C.
Claim 11
Dependent Claim
95 words
The λ-modification of pentaerythritol tetrakis-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], characterised by an X-ray diffraction pattern which exhibits lines of very high intensity at an interplanar spacing of 5.24, 8.4 and 12.4 Å, lines of strong intensity at an interplanar spacing of 4.62, 6.3, 6.6, 6.7, 7.2 and 13.3 Å, lines of medium intensity at an interplanar spacing of 3.78, 3.99, 4.14, 4.22, 4.25, 4.35, 4.44, 4.74, 4.84, 4.98, 5.06, 5.63, 6.0, 9.2 and 11.7 Å, and lines of weak intensity at an interplanar spacing of 3.38, 3.43, 3.72, 3.82, 4.03, 4.40, 4.79, 5.52, 7.0, 10.0, 12.2 and 17.7 Å.
Claim 12
Dependent Claim
95 words
The λ-modification of pentaerythritol tetrakis-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], characterised by an X-ray diffraction pattern which exhibits lines of very high intensity at an interplanar spacing of 5.24, 8.4 and 12.4 Å, lines of strong intensity at an interplanar spacing of 4.62, 6.3, 6.6, 6.7, 7.2 and 13.3 Å, lines of medium intensity at an interplanar spacing of 3.78, 3.99, 4.14, 4.22, 4.25, 4.35, 4.44, 4.74, 4.84, 4.98, 5.06, 5.63, 6.0, 9.2 and 11.7 Å, and lines of weak intensity at an interplanar spacing of 3.38, 3.43, 3.72, 3.82, 4.03, 4.40, 4.79, 5.52, 7.0, 10.0, 12.2 and 17.7 Å.
Claim 13
Dependent Claim
48 words
A process for the preparation of the λ-modification according to claim 10, which comprises heating a melt of pentaerythritol tetrakis-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] which contains δ-crystals of this compound, while mixing thoroughly, to a temperature in the range from 90° C. to the melting point of the system consisting of melt/δ-crystals.
References Cited (Backward Citations)
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