Claims
- 1. A process for manufacturing dimethyl-1,5-naphthalenedicarboxylate comprising the steps of:
dehydrogenating 1,5-dimethyltetralin to produce 1,5-dimethylnaphthalene; oxidizing the 1,5-dimethyinaphthalene obtained from the dehydrogenating step to produce 1,5-naphthalenedicarboxylic acid without performing an intervening isomerization step; and thereafter esterifying the 1,5-naphthalenedicarboxylic acid obtained from the oxidizing step in the presence of methanol to produce dimethyl-1,5-naphthalenedicarboxylate.
- 2. The process of claim 1 further including the step of preparing the 1,5-dimethyltetralin by cyclizing 5-orthotolylpentene in the presence of an acid catalyst.
- 3. The process of claim 2 further including the step of preparing the 5-orthotolylpentene by reacting orthoxylene and butadiene.
- 4. The process of claim 1 wherein the dehydrogenation reaction is conducted in the presence of a supported noble metal catalyst at a temperature between about 150 and 250° C. and a pressure from about 0.3 to 5.0 atmospheres.
- 5. The process of claim 1 wherein the oxidizing step is a liquid phase oxidation conducted in the presence of a catalyst comprising cobalt, manganese and bromine in the presence of a solvent comprising a monocarboxylic acid.
- 6. The process of claim 1 wherein the esterifying step is conducted by heating a mixture of methanol and 1,5-naphthalenedicarboxylic acid to a temperature between about 80 and 200° C. at a pressure between about 3 and 15 atmospheres, and wherein the temperature and pressure are selected to maintain at least a portion of the methanol in a liquid phase.
- 7. The process of claim 1 further including recrystallizing 1,5-dimethyinaphthalene produced in the dehydrogenating step prior to performing the oxidizing step, wherein the recrystallizing step is performed by adding a melt comprising the 1,5-dimethyinaphthalene produced in the dehydrogenation step to a recrystallization solvent maintained at a temperature at least 60° C. less than the temperature of the added melt during the recrystallization step.
- 8. The process of claim 1 further including distilling the 1,5-dimethyltetralin to a purity of at least 95 weight percent prior to performing the dehydrogenating step.
- 9. The process of claim 1 in which the dehydrogenating step is performed in the presence of a catalyst comprising platinum and potassium on a zinc aluminate spinel support.
- 10. A polymer having a 1,5-naphthalenedicarboxyl moiety.
- 11. The polymer of claim 10 which is a homopolyamide comprising aliphatic or cycloaliphatic diamine moieties containing two to twenty carbon atoms.
- 12. The polymer of claim 10 which is a copolyamide comprising up to 40 mole percent (of the total acid mole percent) of a second aliphatic or aromatic dicarboxyl moiety selected from the group consisting of moieties resulting from the polymerization of C3-20 dicarboxylic acids, and an aliphatic diamine moiety containing two to twenty carbon atoms.
- 13. The polymer of claim 12 containing at least one dicarboxyl moiety selected from the group consisting of moieties resulting from adipic acid, terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid.
- 14. The polymer of claim 10 comprising a 1,5-naphthalenedicarboxyl moiety and two or more moieties resulting from the copolymerization of C2-20 aliphatic or cycloaliphatic diamines.
- 15. The polymer of claim 10 wherein the polymer is a polyester containing at least eighty mole percent of a 1,5-naphthalenedicarboxylate moiety.
- 16. The polymer of claim 10 wherein the polymer is a polyester containing between one and 10 mole percent of a 1,5-naphthalenedicarboxylate moiety and at least eighty mole percent of a terephthalate moiety.
- 17. Fibers, films, and molded articles comprising the polymer of claim 10.
- 18. Fibers, films, and molded articles comprising the polymer of claim 15.
- 19. Fibers, films, and molded articles comprising the polymer of claim 16.
- 20. Fibers, films, and molded articles made from the polymer of claim 10 wherein the polymer is a polyester comprising a 1,5-naphthalenedicarboxylate moiety and one or more moieties selected from the group consisting of terephthalate and isophthalate moieties.
Parent Case Info
[0001] This application claims the benefit of U.S. provisional patent application Ser. No. 60/176,145, filed Jan. 14, 2000.
Provisional Applications (1)
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Number |
Date |
Country |
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60176145 |
Jan 2000 |
US |