Process for the treatment of amorphous carbon or graphite manufactured articles, for the purpose of improving their resistance to oxidation, solutions suitable for attaining such purpose and resulting product

• US 3,881,039 A
• Filed: 08/21/1973
• Issued: 04/29/1975
• Est. Priority Date: 01/22/1971
• Status: Expired due to Term

• Current Assignee: Carlo Borgianni, Francesco Baldieri
• Original Assignee: Carlo Borgianni, Francesco Baldieri
• Inventors: Borgianni, Carlo, Baldieri, Francesco
• Primary Examiner(s): Schulz, William E.
• Application Number:
  US05/390,196
• Time in Patent Office: 616 Days
• Field of Search: 117/228,19R 204/294 252/397 148/6.15
• US Class Current: 427/294
• CPC Class Codes: C04B 35/52 based on carbon, e.g. graphite
• CPC Class Codes: C04B 41/009 characterised by the material treated
• CPC Class Codes: C04B 41/4535 applied as a solution, emulsion, dispersion or suspension
• CPC Class Codes: C04B 41/5006 Boron compounds
• CPC Class Codes: C04B 41/5007 with salts or salty compositions, e.g. for salt glazing C04B41/5006 takes precedence
• CPC Class Codes: C04B 41/5009 containing nitrogen in the anion, e.g. nitrites
• CPC Class Codes: C04B 41/501 containing carbon in the anion, e.g. carbonates
• CPC Class Codes: C04B 41/5092 Phosphate cements
• CPC Class Codes: C04B 41/85 with inorganic materials
• CPC Class Codes: C25B 11/044 Impregnation of carbon

Abstract

A process is disclosed for improving the oxidative resistance of amorphous carbon or graphite articles. The process comprises applying a solution of water; an oxide or hydroxide of a group 2 metal; a member of the group consisting of nitric acid; sodium nitrite and sodium carbonate; and boric acid or sodium tetraborate.

Claims

1. PROCESS FOR GIVING RESISTANCE TO OXIDATION TO MANUFACTURED ARTICLES MADE OF AMORPHOUS CARBON OR GRAPHITE, CHARACTERIZED BY THE FACT THAT:

A. SAID MANUFACTURED ARTICLES ARE DEGASSED AND IMMERSED, UNDER VACUUM, IN A SOLUTION OBTAINED BY MIXING;

WATER;

PHOSPHORIC ACID;

ONE OR MORE COMPOUNDS SELECTED FROM THE GROUP OF SALTS, OXIDES AND HYDROXIDES OF A METAL OF THE 2ND GROUP OF THE PERIODIC SYSTEM;

ONE OR BOTH COMPONENTS OF THE GROUP FORMED BY SOIDUM TETRABORATE DECAHYDRATE AND BORIC ACID;

ONE OR MORE COMPONENTS SELECTED FROM THE GROUP FORMED BY NITRIC ACID, SODIUM NIRITE, AND SODIUM CARBONATE;

THE COMPONENTS OF THE SAID SOLUTION ARE MIXED IN ACCORDANCE WITH PERCENTAGE RATIOS BY WEIGHT RANGING BETWEEN 57.0 * 0.1 ;

16.9 ;

0.0 AND 76.0 ;

10.0 ;

6.0 ;

2.0 ;

6.0 REPECTIVELY;

B. THE SAID MANUFACTURED ARTICLES ARE IMPREGNATED WITH SAID SOLUTION;

C. THE SAID MANUFACTURED ARTICLES ARE ALLOWED TO DRY AND SEASON AT ROOM TEMPERATURE.

2. Process for giving resistance to oxidation to manufactured articles made of amorphous carbon or graphite, characterized by the fact that:

a. said manufactured articles are degassed and immersed, under vacuum, in a solution obtained by mixing;

water;

phosphoric acid;

one or more components selected from the group of salts, oxides and hydroxides of a metal of the second group of the periodic system;

sodium tetraborate decahydrate;

one or more compounds selected from the group formed by nitric acid, sodium nitrite, and sodium carbonate;

the components of the solution are mixed in accordance with percentage ratios by weight ranging between 57.0 ;

20.0 ;

5.0 ;

12.0 ;

6.0 and 67.0 ;

16.0 ;

0.4 ;

16.6 ;

0.0 respectively;

b. the said manufactured articles are impregnated with said solution;

c. the said manufactured articles are allowed to dry and season at room temperature.

3. Process for giving resistance to oxidation to manufactured articles made of amorphous carbon or graphite, characterized by the fact that:

a. said manufactured articles are separated aNd immersed, under vacuum, in a solution obtained by mixing;

water;

phosphoric acid;

one or more compounds selected from the group of salts, oxides and hydroxides of a metal of the second group of the periodic system;

boric acid, one or more components selected from the group formed by nitric acid, sodium nitrite, and sodium carbonate;

the components of the solution are mixed in accordance with percentage ratios by weight ranging between 70.0 ;

21.0 ;

2.0 ;

2.0 ;

5.0 and 76.0 ;

16.6 ;

0.4 ;

7.0;

0.0 respectively;

b. the said manufactured articles are impregnated with said solution;

c. the said manufactured articles are allowed to dry and season at room temperature.

4. Process in accordance with claim 1, in which the metal of the 2nd group of the periodic system is calcium.

5. Process in accordance with claim 1, in which the metal of the 2nd group of the periodic system is cadmium.