Compositions – Compositions containing a single chemical reactant or plural... – Organic reactant
Patent
1992-12-21
1994-08-09
Albrecht, Dennis
Compositions
Compositions containing a single chemical reactant or plural...
Organic reactant
134 3, 134 41, 156665, 252 792, 252 794, 252101, 252136, 252142, 252143, 252173, 25217421, C11D 172, C23F 120, C23F 122, C23G 112
Patent
active
053364252
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to an acidic liquid cleaner for articles, such as sheets, strips, containers, and the like, that are made of aluminum or of aluminum alloys that are predominantly aluminum (both hereinafter designated briefly as "aluminum" unless the context requires otherwise). The cleaner is very effective in maintaining its etching capacity and in removing the smut produced by the etching of an aluminum surface as well as in general cleaning.
BACKGROUND ART
Due to problems with waste water treatment, acidic liquid cleaners for aluminum are currently being converted from the fluorine-based cleaners used heretofore to fluorine-free, chromium-free cleaners.
The acidic liquid aluminum cleaners disclosed in, for example, (a) Japanese Patent Application Laid Open [Kokai] Number 61-106783 [106,783/86], (b) Japanese Patent Application Laid Open Number 61-231188 [231,188/86], and (c) Japanese Patent Application Laid Open Number HEI 2-73983 [73,983] are examples of prior art fluorine-free, chromium-free cleaners. The liquid cleaners disclosed in (a) and (b) are sulfuric acid-based acidic liquid cleaners for aluminum. In addition to sulfuric acid, nitric acid, and surfactant, these also contain ferric ion (etching accelerator) and an oxidant (stabilizer for the ferric ion). These compositions are heated to 50.degree. to 80.degree. C. for use in cleaning. The liquid cleaner in (c) is a phosphoric acid-based acidic liquid cleaner for aluminum. In addition to phosphoric acid, sulfuric acid, and surfactant, it contains small amounts of ferric ion (in order to inhibit corrosion of the cleaning equipment) and an oxidant which acts as a stabilizer for the ferric ion. It is heated to 50.degree. to 80.degree. C. for use in cleaning.
DESCRIPTION OF THE INVENTION
Problem to Be Solved by the Invention
These prior art examples are all acidic liquid aluminum cleaners composed of mineral acid, ferric ion, oxidant, and surfactant, and as such they suffer from common problems. Thus, because they are fluorine-free, chromium-free cleaners, their treatment temperatures are higher than for fluorine-based cleaners. Moreover, because they contain oxidant and metal ion, surfactant decomposition occurs to a substantial extent. Not only does this increase consumption of the surfactant, but decomposition product remaining in the treatment bath impairs its degreasing performance. As a consequence, these cleaners lack a robust, durable cleaning activity.
SUMMARY OF THE INVENTION
The present invention seeks to introduce a concrete means for solving the problems outlined hereinbefore for acidic liquid aluminum cleaners comprising mineral acid, oxidant, polyvalent metal ions, and surfactant. It has been found that the problems observed with such cleaners in the prior art are largely or entirely avoided by addition to such an acidic liquid cleaner of 0.05 to 5 grams per liter (hereinafter "g/L") of a component selected from the group of C.sub.2 to C.sub.10 glycols.
DETAILED OF PREFERRED EMBODIMENTS OF THE INVENTION
In more specific terms, a preferred acidic liquid aluminum cleaner with a robust, durable cleaning activity can be obtained by preparing the acidic liquid aluminum cleaner as follows: acid, sulfuric acid, and nitric acid; the concentrations of phosphoric acid and sulfuric acid do not exceed 20 g/L; and the nitric acid concentration does not exceed 10 g/L; concentration is in the range from 0.02 to 3.0 g/L; content is 0.02 to 5 g/L; range from to 0.1 to 5 g/L; C.sub.10 glycols such as propylene glycol, ethylene glycol, diethylene glycol, and triethylene glycol; and
The simultaneous presence of surfactant, polyvalent metal ion (for example, ferric ion), and oxidant in the acidic liquid aluminum cleaner according to the present invention is essential for the effective maintenance of a degreasing capacity and aluminum etchability. In addition, the presence of such compounds also functions to inhibit corrosion of the cleaning equipment.
The mineral acid is exemplified by sulfuric acid, nitric aci
REFERENCES:
patent: 4851148 (1989-07-01), Yamasoe
patent: 4944807 (1990-07-01), Sova
patent: 4970015 (1990-11-01), Garcia
patent: 4980076 (1990-12-01), Tanaka
Chem. Abstracts, vol. 82, No. 2, Jan. 13, 1975, Japan Kokai 74 74,630 (No Month Available).
Aoki Tomoyuki
Asai Shinichiro
Iino Yasuo
Ono Yoji
Albrecht Dennis
Henkel Corporation
Jaeschke Wayne C.
Szoke Ernest G.
Wisdom, Jr. Norvell E.
LandOfFree
Acidic aluminum cleaner containing an oxidant and a nonionic sur does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Acidic aluminum cleaner containing an oxidant and a nonionic sur, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Acidic aluminum cleaner containing an oxidant and a nonionic sur will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-214323