Patent US4245996A successfully refreshed from Google Patents.
US4245996A
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US
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Condensation products of terphenylsulphonic acids, naphthalenesulphonic acids, bis-(4-hydroxyphenyl) sulphone and formaldehyde
Assignee: Bayer AG
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Filing: 1979-07-25
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Granted: 1981-01-20
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Expires: 1999-07-25
Abstract
Abstract Condensation products which are obtained by co-condensation, in an acid aqueous medium, of terphenylsulphonic acids, naphthalenesulphonic acid, bis-(4-hydroxyphenyl) sulphone and compounds which release formaldehyde are used as tanning agents for the production of leather and as re-tanning agents for re-tanning mineral-tanned leather.
Inventors
- 👤 Franz Schade
- 👤 Reinhard Nebeling
- 👤 Bruno Zinz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:56
CPC Classifications
C; C08; C08G; C08G16/00; C08G16/02; C08G16/0212; C08G16/0218; C08G16/0237; C14; C14C; C14C3/00; C14C3/02; C14C3/08; C14C3/18; C14C3/20
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
24 words
Condensation products obtained by co-condensation, in an acid aqueous medium, of terphenylsulphonic acids, naphthalenesulphonic acids, bis-(4-hydroxyphenyl) sulphone and formaldehyde or compounds which release formaldehyde.
Claim 2
Dependent Claim
24 words
Condensation products obtained by co-condensation, in an acid aqueous medium, of terphenylsulphonic acids, naphthalenesulphonic acids, bis-(4-hydroxyphenyl) sulphone and formaldehyde or compounds which release formaldehyde.
Claim 3
Dependent Claim
28 words
Condensation products according to claim 1, obtained by co-condensation of terphenylsulphonic acids, naphthalenesulphonic acids, bis-(4-hydroxyphenyl) sulphone and formaldehyde or compounds which release formaldehyde, in the molar ratio 1:0.2-2.0:0.3-3.5:0.65-5.2.
Claim 4
Dependent Claim
14 words
Condensation products according to claim 1, obtained by co-condensation at temperatures of 75°-130° C.
Claim 5
Dependent Claim
21 words
Condensation products according to claim 1, obtained from sulphonic acids which have been prepared by mixed sulphonation of terphenyl and naphthalene.
Claim 6
Dependent Claim
36 words
In the tanning of hides for the production of leather or the re-tanning of mineral-tanned leather employing a tanning agent, the improvement which comprises employing as said tanning agent a condensation product according to claim 1.
References Cited (Backward Citations)
GB948695A
Cited
US3193575A
Cited
US3423452A
Cited
US3906037A
Cited
US3973904A
Cited
US4009996A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-20 | 1984-07-21 | 1985-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-20 | 1988-07-21 | 1989-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-20 | 1992-07-21 | 1993-01-20 | $7700.00 | Window Closed / Lapsed |