US4065362A
Expired / Lapsed
US
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Purification of organic isocyanates
Assignee: Sumika Covestro Urethane Co Ltd
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Filing: 1975-06-02
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Granted: 1977-12-27
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Expires: 1995-06-02
Abstract
Abstract The present invention provides a process for purifying an organic isocyanate which comprises heating an organic isocyanate in admixture with a treating agent selected from the group consisting of a metal salt of mercaptobenzothiazol, a dithiocarbamic acid derivative, an alkyl-substituted phenol, a thio-bisphenol, and a triaryl phosphite at a temperature not lower than 100° C and subsequently distilling the thusly treated mixture to recover a purified organic isocyanate.
Inventors
- 👤 Yushin Kataoka
- 👤 Tetsuo Harada
- 👤 Kenji Takagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:45
CPC Classifications
C; C07; C07C; C07C263/00; C07C263/18; C07C263/20
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
78 words
A process for purifying an organic isocyanate which comprises heating an organic isocyanate in admixture with at least one treating agent selected from the group consisting of a metal salt of mercaptobenzothiazol, a metal salt of alkyl substituted dithiocarbamic acid, an alkyl substituted phenol, a thio-bis-phenol, and a triaryl phosphite at a temperature not lower than 100° C. to thereby convert coloring impurities to tar and subsequently distilling the thusly treated mixture to recover a purified organic isocyanate.
Claim 2
Dependent Claim
78 words
A process for purifying an organic isocyanate which comprises heating an organic isocyanate in admixture with at least one treating agent selected from the group consisting of a metal salt of mercaptobenzothiazol, a metal salt of alkyl substituted dithiocarbamic acid, an alkyl substituted phenol, a thio-bis-phenol, and a triaryl phosphite at a temperature not lower than 100° C. to thereby convert coloring impurities to tar and subsequently distilling the thusly treated mixture to recover a purified organic isocyanate.
Claim 3
Dependent Claim
11 words
The purified organic isocyanate produced by the process of claim 1.
Claim 4
Dependent Claim
71 words
The process of claim 1 wherein said organic isocyanate is of the formula R(NCO).sub.n wherein R is selected from the group consisting of saturated aliphatic hydrocarbon having 4 to 12 carbon atoms, saturated cycloaliphatic hydrocarbon having from 5 to 15 carbon atoms, aromatic hydrocarbon having from 6 to 15 carbon atoms and araliphatic hydrocarbon having from 7 to 15 carbon atoms and n is an integer of from 1 to 3.
Claim 5
Dependent Claim
45 words
The process of claim 1 wherein said organic isocyanate is selected from the group consisting of 4,4'-diisocyanato diphenylmethane, hexamethylene diisocyanate, tetramethylene diisocyanate, phenyl isocyanate, meta-xylylene diisocyanate, para-xylylene diisocyanate, 4,4'-diphenylether diisocyanate, 1,4-phenylene diisocyanate, 1,5-naphthalene diisocyanate 2,4-diisocyanato toluene, 2,6-diisocyanato toluene, 4,4'-diisocyanato diphenyl ethane and triphenyl methane diisocyanate.
Claim 6
Dependent Claim
13 words
The process of claim 1 wherein said organic isocyanate is 4,4'-diisocyanato diphenyl methane.
Claim 7
Dependent Claim
39 words
The process of claim 1 wherein said treating agent is a metal salt of mercaptobenzothioazole of the formula ##STR7## wherein M is a cation of a metal of Group I, II or VIII of the Periodic Table of Elements.
Claim 8
Dependent Claim
29 words
The process of claim 6 wherein said metal salt is selected from the group consisting of zinc mercaptobenzothioiazole, cupric mercaptobenzothiazole, nickel mercaptobenzothiazole, sodium mercaptobenzothiazole, potassium mercaptobenzothiazole and cobalt mercaptobenzothiazole.
Claim 9
Dependent Claim
88 words
The process of claim 1 wherein said treating agent is a metal salt of alkyl substituted dithiocarbamic acid of the formula ##STR8## wherein R' is alkyl having 1 to 10 carbon atoms; M is a cation of a metal of Group I, II, VI or VIII of the Periodic Table of Elements, n is an integer corresponding to the valence of M and R is alkyl having 1 to 10 carbon atoms or ##STR9## wherein R" and R'" are hydrogen or alkyl having 1 to 5 carbon atoms.
Claim 10
Dependent Claim
34 words
The process of claim 8 wherein said metal salt is selected from the group consisting of zinc dimethyldithiocarbamate, sodium dimethyldithiocarbamate, zinc dimethyldithiocarbamate potassium dibutyldithiocarbamate, sodium dibutyldithiocarbamate, nickel dibutyldithiocarbamate, zinc dibutyldithiocarbamate and zinc ethylphenyl dithiocarbamate.
Claim 11
Dependent Claim
45 words
The process of claim 1 wherein said alkyl substituted phenol is of the formula ##STR10## wherein R and R' are alkyl having 1 to 20 carbon atoms and R" is selected from the group consisting of hydrogen and alkyl having 1 to 20 carbon atoms.
Claim 12
Dependent Claim
32 words
The process of claim 10 wherein said alkyl substituted phenol is selected from the group consisting of 2,4-diisopropyl-5-methyl phenol, 2,4-dimethyl-6-t-butyl phenol, 2,6-di-t-butyl-4-methyl phenol, 2,6-di-t-butyl phenol, 2,6-di-n-dodecyl-4-methyl phenol, 2,4,6-tridecyl phenol and 2,6-didecyl-4-t-butyl phenol.
Claim 13
Dependent Claim
30 words
The process of claim 1 wherein said treating agent is a thiobis-phenol of the formula ##STR11## wherein R and R' are each alkyl having from 1 to 10 carbon atoms.
Claim 14
Dependent Claim
23 words
The process of claim 12 wherein said thiobisphenol is selected from the group consisting of 2,2°-thiobis (4-methyl-6-t-butyl phenol), 4,4'-thiobis-(6-t-butyl-3-methyl phenol) and 4,4'-thiobis-(6-t-butyl-2-methyl phenol).
Claim 15
Dependent Claim
29 words
The process of claim 1 wherein said treating agent is triaryl phosphite of the formula ##STR12## wherein R is hydrogen or alkyl having from 1 to 20 carbon atoms.
Claim 16
Dependent Claim
31 words
The process of claim 14 wherein said triaryl phosphite is selected from the group consisting of triphenyl phosphite, tri (o-cresyl) phosphite, tri (p-cresyl) phosphite, trioctylphenyl phosphite, tridecylphenyl phosphite and trinonylphenyl phosphite.
Claim 17
Dependent Claim
41 words
The process of claim 1 wherein said treating agent is selected from the group consisting of zinc mercaptobenzothiazole, cupric mercaptobenzothiazole, 2,4-dimethyl-6-t-butylphenol, 2,6-t-butyl-4-methyl phenol, 4,4'-thiobis (6-t-butyl-3-methyl phenol), 4,4'-thiobis (6-t-butyl-2-methyl phenol), nickel dibutyl dithiocarbamate, zinc dimethyl dithiocarbamate, triphenyl phosphite and tri (o-cresyl) phosphite.
Claim 18
Dependent Claim
29 words
The process of claim 1 wherein said treating agent is present in an amount of about 0.001 to about 5% by weight, based on the weight of organic isocyanate.
Claim 19
Dependent Claim
21 words
The process of claim 1 wherein said heating step is carried out at a temperature of from 150° to 250° C.
Claim 20
Dependent Claim
18 words
The process of claim 1 wherein said heating step is carried out for from 0.1 to 10 hours.
Claim 21
Dependent Claim
40 words
The process of claim 1 wherein said heat treatment is carried out in the presence of an inert organic solvent selected from the group consisting of n-hexane, toluene, monochlorobenzene, o-dichlorobenzene, p-dichlorobenzene, trichlorobenzene, chlorinated toluenes, chlorinated xylenes, chloroethylbenzene, benzene and xylene.
Claim 22
Dependent Claim
51 words
The purified organic isocyanate produced by the process of claim 1 wherein said organic isocyanate is selected from the group consisting of 4,4'-diisocyanato diphenylmethane, hexamethylene diisocyanate, tetramethylene diisocyanate, phenyl isocyanate, meta-xylylene diisocyanate, para-xylylene diisocyanate, 4,4'-diphenylether diisocyanate, 1,4-phenylene diixocyanate, 1,5-naphthalene diisocyanate 2,4-diisocyanato toluene, 2,6-diisocyanato toluene, 4,4'-diixocyanato diphenyl ethane and triphenyl methane diisocyanate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-12-26 | 1981-06-27 | 1981-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-12-26 | 1985-06-27 | 1985-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-12-26 | 1989-06-27 | 1989-12-27 | $7700.00 | Window Closed / Lapsed |