US4171305A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Blocked isocyanate
Assignee: Takeda Pharmaceutical Co Ltd
•
Filing: 1978-01-09
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Granted: 1979-10-16
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Expires: 1998-01-09
Abstract
Abstract Substantially pure crystals of epsilon -caprolactam-diblocked omega , omega '-diisocyanato-1,3-dimethylbenzene melting at 110 DEG C. or higher are advantageously used as a hardener of powder coating composition.
Inventors
- 👤 Kazutaka Mochizuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:23
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/70; C08G18/72; C08G18/74; C08G18/76; C08G18/7614; C08G18/7628; C08G18/7642; C08G18/80; C08G18/8061; C08G18/807; C08G18/8074; C09; C09D; C09D175/00; C09D175/04; C08G2150/00; C08G2150/20
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
14 words
Substantially pure crystals of ε-caprolactam-diblocked ω,ω'-diisocyanato-1,3-dimethylbenzene, said crystals melting at 110° C. or higher.
Claim 2
Dependent Claim
14 words
Substantially pure crystals of ε-caprolactam-diblocked ω,ω'-diisocyanato-1,3-dimethylbenzene, said crystals melting at 110° C. or higher.
Claim 3
Independent Claim
42 words
A method of producing substantially pure crystals of ε-caprolactam-diblocked ω,ω'-diisocyanato-1,3-dimethylbenzene, said crystals melting at 110° C. or higher, which comprises crystallizing ε-caprolactam-diblocked ω,ω'-diisocyanato-1,3-dimethylbenzene from a solution thereof or allowing said compound to stand as fused at a temperature not exceeding 100° C.
Claim 4
Independent Claim
42 words
A method of producing substantially pure crystals of ε-caprolactam-diblocked ω,ω'-diisocyanato-1,3-dimethylbenzene, said crystals melting at 110° C. or higher, which comprises crystallizing ε-caprolactam-diblocked ω,ω'-diisocyanato-1,3-dimethylbenzene from a solution thereof or allowing said compound to stand as fused at a temperature not exceeding 100° C.
Claim 5
Dependent Claim
24 words
A method as claimed in claim 2, wherein ε-caprolactam-diblocked ω,ω'-diisocyanato-1,3-dimethylbenzene is allowed to stand as fused at a temperature ranging 50° to 100° C.
Claim 6
Dependent Claim
24 words
A method as claimed in claim 2, wherein ε-caprolactam-diblocked ω,ω'-diisocyanato-1,3-dimethylbenzene is allowed to stand as fused at a temperature ranging 60° to 90° C.
Claim 7
Dependent Claim
24 words
A method as claimed in claim 2, wherein ε-caprolactam-diblocked ω,ω'-diisocyanato-1,3-dimethylbenzene is allowed to stand as fused at a temperature ranging 75° to 85° C.
References Cited (Backward Citations)
US2698845A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-10-15 | 1983-04-16 | 1983-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-15 | 1987-04-16 | 1987-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-15 | 1991-04-16 | 1991-10-16 | $7700.00 | Window Closed / Lapsed |