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US4051276A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of deacidifying paper

Assignee: Government of the United States of America
•
Filing: 1976-02-23
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Granted: 1977-09-27
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Expires: 1996-02-23
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Abstract

Abstract This invention relates to solutions of selected organo-metallic compounds ssolved in an organic solvent which are useful for deacidifying a cellulose fiber paper. The paper is treated by means well known in the art, such as dipping or spraying. The organo-metallic compounds useful in this invention are compounds which may be rapidly hydrolyzed to an alkaline material such as lower alkyl compounds of lithium, aluminum, magnesium, gallium, zinc, and mixtures of these compounds. The organic solvent is a liquid which will not react with the organo-metallic compound, dissolve inks, or cause discoloration of other materials usually found in and around printed matter. After the paper is impregnated with the solution the organo-metallic compound remaining on the paper is hydrolyzed to an alkaline material.

Inventors

  • 👤 John C. Williams
  • 👤 George B. Kelly, Jr.

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 02:11
CPC Classifications
D; D21; D21H; D21H25/00; D21H25/18; D21H17/00; D21H17/03; D21H17/05; D21H17/12

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 85 words
A method of deacidifying paper having a cellulosic base comprising impregnating said paper with a solution of an organo-metallic compound capable of being rapidly hydrolyzed to an alkaline material wherein said compound is selected from the group consisting of lower alkyl compounds of lithium, aluminum, magnesium, gallium, zinc, and mixtures thereof, and wherein the solvent for said compound is an organic liquid, unreactive with said organo-metallic compound and non-destructive to inks used on printed matter, and subsequently hydrolyzing said organo-metallic compound to an alkaline material.
Claim 2
Independent Claim 85 words
A method of deacidifying paper having a cellulosic base comprising impregnating said paper with a solution of an organo-metallic compound capable of being rapidly hydrolyzed to an alkaline material wherein said compound is selected from the group consisting of lower alkyl compounds of lithium, aluminum, magnesium, gallium, zinc, and mixtures thereof, and wherein the solvent for said compound is an organic liquid, unreactive with said organo-metallic compound and non-destructive to inks used on printed matter, and subsequently hydrolyzing said organo-metallic compound to an alkaline material.
Claim 3
Dependent Claim 12 words
A method according to claim 1 wherein the organo-metallic compound comprises diethylzinc.
Claim 4
Dependent Claim 13 words
A method according to claim 1 wherein the organo-metallic compound comprises di-n-butylmagnesiumtriethylaluminum complex.
Claim 5
Dependent Claim 21 words
A method according to claim 1 wherein the organo-metallic compound is present in concentrations of up to 15% in said solution.

References Cited (Backward Citations)

US2957785A Cited
US3472611A Cited
US3676182A Cited
US3676055A Cited
US3703353A Cited
US3771958A Cited
US3898356A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1980-09-26 1981-03-28 1981-09-27 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1984-09-26 1985-03-28 1985-09-27 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1988-09-26 1989-03-28 1989-09-27 $7700.00 Window Closed / Lapsed

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