Acid removal in cleaning processes

• US 8,029,623 B2
• Filed: 06/30/2009
• Issued: 10/04/2011
• Est. Priority Date: 07/08/2008
• Status: Expired due to Fees

• Current Assignee: Safechem Europe GmbH (Dow, Inc.)
• Original Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Inventors: Geissler, Konrad, Kuemin, Marius
• Primary Examiner(s): CARRILLO, BIBI SHARIDAN
• Application Number:
  US12/737,381
• Publication Number:
  US 20110100398A1
• Time in Patent Office: 826 Days
• Field of Search: 134/2, 134/3, 134/10, 134/12, 134/26, 134/27, 134/28, 134/30, 134/34, 134/35, 134/36, 134/41, 134/42, 210/681, 210/685
• US Class Current: 134/10
• CPC Class Codes: B01J 41/05 in the strongly basic form
• CPC Class Codes: B08B 3/08 the liquid having chemical or dissolving effect substances used, see the relevant classes
• CPC Class Codes: B08B 3/14 Removing waste, e.g. labels, from cleaning liquid; Regenerating cleaning liquidstreatment of water in general C02F

Abstract

Embodiments of the present disclosure include cleaning processes, cleaning machines, and methods of preventing acidification of a cleaning composition in a cleaning process. The cleaning process includes contacting an article having contaminants with a cleaning composition to remove the contaminants from the article, where the cleaning composition comes to have acidic components as a result of contacting the article with the cleaning composition, and where at least 85 percent by weight, based on a total weight of the cleaning composition, of the cleaning composition is an organic solvent, collecting the cleaning composition with the contaminants and the acidic components, separating the contaminants from the cleaning composition (114), and passing the cleaning composition with the acidic components over an ion exchange resin (125) to remove the acidic components from the cleaning composition.

Claims

1. A cleaning process, comprising:

providing an article formed of a material selected from the group consisting of metal, ceramic, glass or plastic, wherein the article has contaminants on its surface;

in a cleaning chamber contacting the article with a cleaning composition having at least 85 percent by weight of an organic solvent based on a total weight of the cleaning composition;

removing the contaminants from the article, where the cleaning composition acquires acidic components from the contaminants removed from the article or from side reactions occurring in the cleaning process;

collecting the cleaning composition with the contaminants and the acidic components;

separating the contaminants from the cleaning composition; and

passing the cleaning composition with the acidic components over an ion exchange resin to remove the acidic components from the cleaning composition.

2. The process of claim 1, where the ion exchange resin is a styrene-divinylbenzene copolymer resin.

3. The process of claim 1, where passing the cleaning composition with the acidic components over the ion exchange resin to remove the acidic components from the cleaning composition occurs continuously.

4. The process of claim 1, where the organic solvent in the cleaning composition is selected from a group consisting of alcohols, propylene glycol ethers, ethylene glycol ethers, ethylene glycol ether acetates, propylene glycol ether acetates, esters, hydrocarbons, or mixtures thereof.

5. The process of claim 1, where passing the cleaning composition with the acidic components over the ion exchange resin to remove the acidic components from the cleaning composition occurs semi-continuously.

6. The process of claim 1, where the cleaning composition contains less than 15 percent water based on the total weight of the cleaning composition.

7. A method of removing acidic components from of a cleaning composition in a cleaning process, comprising:

providing an article formed of a material selected from the group consisting of metal, ceramic, glass or plastic, the article having contaminants on a surface of the article, where the contaminants are to be removed;

in a cleaning chamber contacting the surface of the article with the cleaning composition having at least 85 percent by weight of an organic solvent based on a total weight of the cleaning composition to remove the contaminants from the surface of the article, where the cleaning composition acquires acidic components from the contaminants removed from the article or from side reactions occurring in the cleaning process;

collecting the cleaning composition with the contaminants and the acidic components;

separating the contaminants from the cleaning composition; and

passing the cleaning composition with the acidic components over an ion exchange resin to remove the acidic components from the cleaning composition.

8. The method of claim 7, where the ion exchange resin is an anion exchange resin.

9. The method of claim 7, where the ion exchange resin is in OH⁻

form.

10. The method of claim 7, where the cleaning composition has a boiling point in a range of about 40 degrees Celsius to about 240 degrees Celsius.

11. The method of claim 10, where the cleaning composition has a boiling point in a range of about 90 degrees Celsius to about 200 degrees Celsius.