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US4246103A Expired / Lapsed US ⏱️ 0.0 years remaining

Propane-1,3-diphosphonic acids for conditioning water

Assignee: Bayer AG
•
Filing: 1979-02-28
•
Granted: 1981-01-20
•
Expires: 1999-02-28
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Abstract

Abstract Water is conditioned by adding thereto a corrosion-inhibiting, concretion inhibiting, precipitation retarding, deflocculating, dispersing or fluidifying amount of an acid of the formula ##STR1## in which R 1 and R 2 , independently of one another, represent hydrogen where a or b=1, or where a or b=0 represent an optionally substituted alkyl radical with 1-8 carbon atoms or an optionally substituted phenyl radical, R 3 represents hydrogen, an optionally substituted alkyl radical with 1 to 4 carbon atoms, an optionally substituted phenyl radical, a halogen atom from the group comprising fluorine, chlorine and bromine, a hydroxyl group, an alkoxy group containing 1 to 8 carbon atoms, a carboxyl group or a group --P(O)--(O) a --R 1 OH, R 4 represents hydrogen, an alkyl radical with 1 to 4 carbon atoms, an alkenyl radical with up to 3 carbon atoms, an optionally substituted phenyl radical, a carboxyl group, a fluorine or chlorine atom or a group --P(O)--(O) a --R 1 OH, or R 3 and R 4 together form a ring bridge with 3 to 5 methylene groups, R 5 represents hydrogen, an optionally substituted alkyl radical with 1 to 4 carbon atoms, a carboxymethyl or carboxyethyl group optionally substituted by a methyl group, a succinyl group or a group having the structure--CHR 4 --CHR 3 --P(O)--(O) a --R 1 OH or the structure--CH 2 --P(O)--(O) a --R 1 OH, R 6 represents an optionally substituted phenyl radical, a carboxyl group or a group having the structure --P(O)--(O) b --R 2 OH, and a and b independently of one another represent the numbers 0 or 1, or a salt thereof.

Inventors

  • 👤 Hans-Dieter Block
  • 👤 Herbert Kallfass
  • 👤 Roland Kleinstuck

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 18:33
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C23F11/10; C23F11/167; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/14; C23F11/1676

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 71 words
In the conditioning of water by adding thereto an amount of a phosphorus containing acid or salt thereof effective to inhibit precipitation of hard water ions contained therein, the improvement which comprises employing as said acid or salt thereof a 1-substituted propane-1,3-diphosphonic acid of the formula ##STR3## in which R 3 represents hydrogen, or a carboxy group, and R 5 represents hydrogen, a carboxymethyl or carboxyethyl group, or a salt thereof.
Claim 2
Dependent Claim 71 words
In the conditioning of water by adding thereto an amount of a phosphorus containing acid or salt thereof effective to inhibit precipitation of hard water ions contained therein, the improvement which comprises employing as said acid or salt thereof a 1-substituted propane-1,3-diphosphonic acid of the formula ##STR3## in which R 3 represents hydrogen, or a carboxy group, and R 5 represents hydrogen, a carboxymethyl or carboxyethyl group, or a salt thereof.
Claim 3
Dependent Claim 13 words
The process according to claim 1, wherein the diphosphonic acid is 1,3-diphosphonobutane-3,4-dicarboxylic acid.
Claim 4
Dependent Claim 13 words
The process according to claim 1, wherein the diphosphonic acid is 1-carboxypropane-1,3-diphosphonic acid.

References Cited (Backward Citations)

US3297578A Cited
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US3617575A Cited
US3743688A Cited
US3886205A Cited
US3923876A Cited
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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

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