# US 4,396,769 A · Process for preparing crystalline, non-dusting bis(2,2,6,6-tetramethylpiperidin-4-yl) sebacate

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- Number: US 4,396,769 A
- Document ID: US4396769A
- Status: Granted
- Kind: A
- Application number: 06/347,751
- Filed: 1982-02-11
- Granted: 1983-08-02
- Earliest claimed: 1982-02-11
- Assignees: Ciba-Geigy Corporation
- Inventors: Anibal L. Ferreira; Robert E. Stahlbush
- Web page: https://patentgrep.com/patent/US4396769A

## CPC

- C07D 211/46: having a hydrogen atom as the second substituent in position 4
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)

## Abstract

Crystalline, non-dusting bis(2,2,6,6-tetramethylpiperidin-4-yl) sebacate is made by heating the sebacate ester to a temperature above its melting point and then slowly cooling the melt with agitation to form the product in a crystalline, non-dusting form. This ester, also known as TINUVIN 770, is a valuable commercial light stabilizer for a myriad of substrates.

## Claims

### Claim 1

A process for preparing bis(2,2,6,6-tetramethylpiperidin-4-yl) sebacate in a crystalline, non-dusting form having a particle size greater than 100 microns and with a volatiles content less than 0.5% by weight, which comprises
heating bis(2,2,6,6-tetramethylpiperidin-4-yl) sebacate, in the form of a friable, dusting powder or wet paste, to above its melting point, at a temperature between 83.degree. and 95.degree. C. under a pressure of 5 to 150 mm Hg with agitation to form a uniform melt of the sebacate, and then
slowly cooling the melt, with continued agitation, to a temperature between 70.degree. and 83.degree. C. to cause the sebacate to crystallize from the melt in a crystalline, non-dusting form.

### Claim 2 (depends on 1)

A process according to claim 1 wherein the bis(2,2,6,6-tetramethylpiperidin-4-yl) sebacate being heated is in the form of a wet paste.

### Claim 3 (depends on 1)

A process according to claim 1 wherein the bis(2,2,6,6-tetramethylpiperidin-4-yl) sebacate being heated is in the form of a friable, dusting powder.

### Claim 4 (depends on 1)

A process according to claim 1 wherein the sebacate in form of a powder or wet paste is heated at a temperature between 83.degree. and 88.degree. C. under a pressure of 5 to 50 mm Hg and is then slowly cooled with agitation to a temperature between 72.degree. and 74.degree. C. to effect crystallization into a crystalline, non-dusting form.