US3928346A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solid hardener compositions
Assignee: Napko Corp
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Filing: 1974-10-29
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Granted: 1975-12-23
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Expires: 1994-10-29
Abstract
Abstract Solid hardener compositions suitable for curing polyester resins are prepared by condensing carboxylic anhydrides with hexamethoxymethyl melamines.
Inventors
- 👤 William A Wentworth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:46
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/16; C08K5/34; C08K5/3467; C08K5/3477; C08K5/3492; C08K5/34922; C07; C07D; C07D251/00; C07D251/02; C07D251/12; C07D251/26; C07D251/40; C07D251/54; C07D251/70; C09; C09D; C09D167/00
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
59 words
A METHOD OF PREPARING A SOLID HARDENED WHICH COMPRISES HEATING A MIXTURE CONSISTING OF: A. FROM 25 TO 75 MOL PERCENT OF A CARBOXYLIC ACID ANHYDRIDE SELECTED FROM THE GROUP CONSISTING OF PHTHALIC ANHYDRIDE AND HEXAHYDROPHTHALIC ANHYDRIDE B. FROM 0 TO 50 ,OL PERCENT OF A MONOCARBOXYLIC, AROMATIC, NON-HETEROCYCLIC ACID, C. AT LEAST 25 MOL PERCENT OF HEXAMETHOXYMETHYL MELAMINE.
Claim 2
Independent Claim
59 words
A METHOD OF PREPARING A SOLID HARDENED WHICH COMPRISES HEATING A MIXTURE CONSISTING OF: A. FROM 25 TO 75 MOL PERCENT OF A CARBOXYLIC ACID ANHYDRIDE SELECTED FROM THE GROUP CONSISTING OF PHTHALIC ANHYDRIDE AND HEXAHYDROPHTHALIC ANHYDRIDE B. FROM 0 TO 50 ,OL PERCENT OF A MONOCARBOXYLIC, AROMATIC, NON-HETEROCYCLIC ACID, C. AT LEAST 25 MOL PERCENT OF HEXAMETHOXYMETHYL MELAMINE.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein the solid hardener is prepared from 1 mol of phthalic anhydride and 1.95 mols of p-tertiary butyl benzoic acid.
Claim 4
Dependent Claim
16 words
The method of claim 1 wherein the monocarboxylic aromatic non-heterocyclic acid is para tertiary butylbenzoic acid.
References Cited (Backward Citations)
US3806480A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-22 | 1979-06-23 | 1979-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-22 | 1983-06-23 | 1983-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-22 | 1987-06-23 | 1987-12-23 | $7700.00 | Window Closed / Lapsed |