JPS581078A - Aluminum surface detergent alkaline solution - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for cleaning aluminum surfaces containing an alkali metal hydroxide, an alkali metal salt of E'DT A, a surfactant and optionally an aluminum metal ion/seal [IJ] such as sorbitol. Compositions and methods.

Aluminum and aluminum alloy containers are manufactured by drawing and forming operations commonly referred to as drawing and ironing. This operation results in the deposition of lubricant and molding oil on the container surface. In addition, residual aluminum flakes are deposited on the surface and are present in relatively large amounts on the inner surface of the container.

Before a container is subjected to, for example, chemical treatment or sanitary lacquering, the surface of the container must be cleaned and drained so that no contaminants remain on the surface which would interfere with further processing of the container.

A composition currently used commercially to clean such aluminum containers is an aqueous sulfuric acid solution containing hydrofluoric acid and one or more surfactants. While such cleaning solutions are very effective and have many advantages, there are also certain disadvantages associated with such acidic cleaning compositions. For example, such compositions can dissolve stainless steel and other ferrous alloy equipment commonly utilized in vessel cleaning lines, and hydrofluoric acid and fluorides present in aging cleaning baths and rinse waters can be disposed of. poses environmental problems.

Although alkaline cleaning solutions have been formulated in the past to attempt to overcome the above problems, such alkaline solutions have created new and significant problems of their own that have reduced their commercial use. For example, attempts at cleaning solutions using alkali metal hydroxides have resulted in extensive and irregular etching of aluminum containers, rendering the containers commercially unacceptable.

Other alkaline solutions have been tried but have not been successful due to poor cleaning results and other problems.

Now, we have found that alkaline cleaning solutions containing alkali metal hydroxides can be formulated into I to eliminate the problems of acidic cleaning solutions, while at the same time cleaning aluminum surfaces regardless of the hardness of the tap water used to form the cleaning solution. It has been discovered that controlled and uniform etching can be easily provided. Additionally, these solutions are inexpensive to formulate, offering significant economic advantages. Additionally used in the formation of cleaning solutions.

A concentrated solution can be easily prepared. Some of these concentrates are clear solutions that are stable over a wide range of temperatures. These concentrates are easily prepared due to the high water solubility of their components and can be transported and stored even under unfavorable ambient temperature conditions.

Additionally, the concentrates of the present invention can contain all the components necessary to form a cleaning solution, unlike acidic concentrates where the addition of hydrofluoric acid to the concentrate is impractical. Hydrofluoric acid generally must be added separately under controlled and metered conditions, requiring extra steps and expense to form the cleaning solution. Aluminum containers cleaned with the cleaning solution of the present invention are drain-free and essentially free of residual aluminum debris.

Conventionally known acidic cleaning compositions for cleaning aluminum surfaces include:
U.S. Patent No. 4009115 and U.S. Patent No. 4116853
No. 412 (Robert Er1c Binns)
No. 4407 (Robert E, B1nn5), No. 3
No. 969135 (Peter F. King).

Previously known alkaline or neutral cleaning compositions for cleaning metal surfaces are disclosed, for example, in the following patents: US Pat.

U.S. Patent No. 3,975,215 (issued Aug. 17, 1976, Edward A. Rodzewich) U.S. Patent No. 3,888,783 (issued June 10, 1975, E.
dward A, Rodzewich) Japanese Patent Application Publication No. 1983-
No. 149130 (Japan Pariki Rising) JP-A No. 1983-067726 (Kurita Industries) JP-A-1973-
No. 103033 (Diary) U.S. Patent No. 4093566 (USA) Japanese Patent Application Laid-Open No. 149830/1983 (Desk Electric Appliances Industry) The present invention provides an alkali-IJ cleaning aqueous solution and method for cleaning aluminum surfaces, and a method for use in the formulation of the cleaning solution. Concerning concentrated liquids.

The aqueous cleaning solution of the present invention contains about 0.5 to 3 Vl, preferably about 1 to 29 Vl of alkali metal hydroxide, about 1 to 5 Vl.
l , preferably about 1.5 to 31/j, of the alkali metal salt of ethylenediaminetetraacetic acid, and about 01 to l O
9/l, preferably about 0.2-2. Contains OVl surfactant. It also preferably optionally contains about 05 to 10 g/l, preferably about 06 to 1.3 Vl of aluminum sequestering agent.

The alkali metal hydroxide is preferably sodium hydroxide;
Potassium hydroxide and lithium hydroxide can be used equally well, but are more expensive than sodium hydroxide.

The alkali metal salt of ethylenediaminetetraacetic acid is preferably sodium salt, and potassium salt or lithium salt can also be used. Preferably, the iron salt is a di-, tri- or tetra-alkali metal salt, or a mixture of such salts. Mono-alkali metal salts may also be used or tend to have slightly lower solubility in the concentrates of the present invention.

Surfactants may be anionic, cationic or nonionic, and combinations of two or more surfactants may also be used. Specific examples of surfactants that can be used in the cleaning solution of the present invention include US Pat. No. 4,116,853 (1).
Published September 26, 1978, columns 6 and 7, the disclosure of which is specifically incorporated herein by reference. However, certain surfactant agents and/or surfactant combinations are preferred in the practice of the present invention. A preferred surfactant is TRITON DF-20 (Rohm
&HaasCO3, an anionic surfactant believed to consist of 2 parts of a modified polyethoxylated linear alcohol and 1 part of a linear alkyl succinate), PLURAFACD
-25 (BASF Wyandotte Corp.,
nonionic surfactant believed to be a modified oxyethylated linear alcohol), 5URFACTANT AR
15Q (Hercules Inc., a nonionic surfactant believed to be an ethoxylated abietic acid derivative with about 15 moles of ethoxylation), 5URFA
CTAN'rAR15Q and 5URFONICLP01 (
Jefferson Chemical Co., a combination of nonionic surfactants believed to be alkyl polyethoxylated ethers, PLURONIC31
R1 (BASF Wyandotte Inc., approx. 9
TRITON DF-20 and TRITON DF-20 and TRITON DF-20 and 2-
Combinations of alkali metal salts (preferably the sodium salt, but the potassium or lithium salts can equally well be used) of butoxyethoxyacetate may be mentioned. When one of the surfactant combinations described above is employed, it is preferred that about 01 to 1, OVl of each surfactant be present in the aqueous cleaning composition. is, in fact, even more suitable for use in the cleaning solution of the present invention based on its ability to prevent discoloration of aluminum cans that are left wet with the cleaning solution during line outages, especially when an aluminum sequestering agent is also present. This is preferable. The most preferred surfactant for use in the present invention is TRI TONDF-20,
Used alone or in combination with an alkali metal salt of 2-butoxyethoxyacetate. This is because such surfactants or surfactant combinations form very stable and uniform concentrates.

The aluminum metal ion sequestering agent, which may be included in the cleaning solution of the present invention if necessary, may be any compound known to have the ability to sequester aluminum metal ions in an aqueous solution. Specific examples of such compounds include sorbitol, alkali metal gluconic acid salts (e.g., alkali metal salts of glucoheptonate with sodium salts (e.g., sodium salts)
, and alkali metal salts of tartrate (e.g., sodium salt), with sorbitol and sodium glucoheptonate being preferred.

The aqueous concentrates of the invention that can be advantageously used to form the cleaning solutions of the invention are about 25-250! 1171 alkali metal hydroxide, and about 0.33 to 10 parts by weight, preferably about 0.5 parts by weight per part by weight of alkali metal hydroxide.
~6 parts by weight of the alkali metal salt of ethylenediaminetetraacetic acid, about 0.033 to 20 parts by weight, preferably about Q,0
67 to 4 parts by weight of surfactant, and optionally about 0.
It contains 17 to 20 parts by weight, preferably about 0.20 to 2.6 parts by weight, of an aluminum sequestering agent. Using the above ratios as a guide, and according to the desired amount of alkali metal hydroxide in the cleaning solution of the present invention, the actual amounts of the alkali metal salt of ethylenediaminetetraacetic acid, surfactant and aluminum sequestering agent in the concentrate should be adjusted as above. As determined from within the ratio, the desired amount of each of these components will be present in the cleaning solution when the concentrate is diluted with the appropriate amount of water. For example, 0
．． If 5 W/l of alkali metal hydroxide is desired in the cleaning solution, about 2 to 10 grams of alkali metal salt of ethylenediaminetetraacetic acid, about 0.2 to 20 grams of surfactant, and optionally about 1. 0~20f! Aluminum metal,
An ion sequestering agent is present in the concentrate at 11 parts alkali metal hydroxide. If 3 f/l of alkali metal hydroxide is desired in the cleaning solution, about 0.3'1 to 1.6
7y alkali metal salt of ethylenediami/tetraacetic acid,
About 0.033 to 3.335' of surfactant and optionally about 0.17 to 333 grams of aluminum sequestering agent are present per 11 alkali metal hydroxides in the concentrate.

As mentioned above, the most highly preferred surfactant for use in the concentrates of the present invention is TRITON DF-20, used alone or in combination with alkali metal 2-buto-1 jetoxy acetate.

This was the only surfactant or surfactant combination found to be freely soluble in the concentrate.

All others tested formed a separate layer on top of the concentrate when the freshly prepared concentrate was allowed to stand. Although this is a significant disadvantage for other surfactants, it is not fatal for use in forming the cleaning solutions of the present invention.
For example, surfactants can be added separately to form a cleaning solution, or concentrates containing surfactants can be mixed thoroughly by stirring or shaking just before being added to the water to form a cleaning solution. I can do it. On the other hand, a layered, concentrated solution can be filled into a container small enough that its entire volume can be added to the cleaning solution formation.

A measured amount of the above concentrate is added to water to produce a cleaning solution of the invention having the desired amounts of components.

The method of the present invention consists of contacting the aluminum or aluminum alloy surface to be cleaned with the aqueous cleaning composition of the present invention employing any contacting technique known in the art, such as conventional spraying or dipping techniques. The temperature of the cleaning composition is preferably maintained in the range of about 90-120'F, although temperatures of about 80-150'F can also be employed. The treatment time with the cleaning solution is usually about 10 seconds to 2 minutes, preferably about 1 minute.
It is about 0 seconds to 2 minutes.

Following the cleaning step, the aluminum surface is rinsed with water to remove the cleaning solution. The aluminum surface may then be treated with coating solutions or dry finish coating compositions well known in the art. Also, pre-rinsing the aluminum surface with water before the cleaning step is sometimes beneficial to reduce the amount of contaminants entering the cleaning bath.

Aged cleaning solutions and rinse waters pose several problems in their safe disposal.

For example, by treating the aged cleaning solution with a small amount of peroxide, such as hydrogen peroxide, the alkali metal salt of ethylenediaminetetraacetic acid is readily oxidized to environmentally relatively harmless components. To render the alkali metal hydroxide harmless, water containing hydrochloric acid can be added until a pH of about 7 is obtained.

The present invention will be specifically explained with reference to the following examples, but is not limited thereto.

Examples 1-6 The following amounts of ingredients were mixed to form the concentrates of 1j.

Example l NaOH50,009 Na EDTA arrow 100,00
Gutrubitol (70% solution) 7
1.40 FMIRAWET B (solution containing 49% sodium 2-butoxyethoxyacetate) 23
．． 001 Water Appropriate amount Example 2 NaOH100,005' Na 4 E DTA 10
o, 00 yMIRAWET B
47.4 P water
Appropriate amount Example 3x8 NaOH50, OOS' Na a E DTA 10
0.00y Sorbitol (70% solution)
71.40FTRITON DF-16 (modified polyethoxylated linear alcohol)
23.00 y Water Appropriate amount Example 488 KOH150, OOg Na 4 E DT A 3
0 o, 00 y Sodium gluconate
175.00 f! TRITON CF-10 (
alkylaryl polyether)
125.0Of water Appropriate amount LiOH200.00g Na 4 E DTA 20
o, OOyPLLJRONICLO61 (condensate having a chain of tylene oxide and propylene oxide) 200, OOy ~ Water Appropriate amount Example 6XX N ao) (50,00S' Na 4 E DT A 15
o, OOLi potassium tartrate 5
0.00 PSURFACTANT A 150 (ethoxylated abietic acid) 1
50.00yANTAROX LF-330 (7l + Lupo IJ (nee f-lenoxy) ethanol)
35.007 Water as needed

Example Eva, N h 4 B DT A is the tetrasodium salt of ethylenediaminetetraacetic acid.

MM) The concentrates of Examples 3-6 exhibited stratification upon standing, which were vigorously shaken or stirred before removing the trimmings to form the cleaning solutions of Examples 9-12.

Example 7 Add 120- of the concentrated solution of Example 1 to water 5.880/(2-ti solution) to obtain NaOHIY/l, Na4EDTA2
Y/l, sorbitol (70% solution) 1.43 V
! and MIRAWET B 0.46 f/l was formed. The wash solution was stirred to homogenize.

A 3004 alloy aluminum can drawn into a single piece container was used for this process. The can was covered with aluminum strips and drawn oil.

The test pieces were treated as follows.

(a) The above cleaning solution was maintained at 110″F and sprayed for 1 minute.

(b) Immersed in cold water for 30 seconds and rinsed with water.

(c) After standing for 30 seconds, drainage was tested on both the inner and outer surfaces.

(d) Wipe the inside with a clean white cloth and test the aluminum strip with iron blood.

The aluminum can did not drain and there were no aluminum strips.

Example 8 120 m7 of the concentrate from Example 2 are added to 5.880 m/l of water, the same amount as in Example 7, except that 29/l of NaOH is present! A cleaning solution 6I was formed containing four amounts of each component.

Aluminum cans (3
The method of Example 7 was repeated for 004 alloy). After cleaning, the aluminum can had no water and no aluminum pieces.

Example 9 Add 120rnl of the concentrated solution of Example 3 to 5.8807ml of water to obtain 15'/l of NaOH, 3EDT of NaOH.
A 29/l 1 Sorbitol (70% solution) 1.4
TILITON D of 39/l and 0.46fI/l
A wash solution 61 containing F-16 was formed. The cleaning solution was stirred to homogenize and the aluminum can (3004 alloy) coated with aluminum strips and drawing oil was treated according to the method of Example 7. The treated aluminum cans were free of water and aluminum flakes.

Examples 10-12 Each concentrated solution 120- of Examples 4, 5.6 was added to water 58801 to form a cleaning solution 6j (2% solution). Example 4
Aluminum cans were treated with each cleaning solution according to the method of Example 7, except that the cleaning solutions prepared from the concentrates of Example 7 were maintained at 90°F.

All three cans were free of water and aluminum strips.

Example 13 A concentrate 1/ was prepared from the following ingredients.

KOH89,95g N a 4E DT A 10
o,OO'1TRITON DF-2030,60F
Beta Na Glucoheptonate
32. Appropriate amount of 501i' water.
TRITON DF-20,5 of 14-130,601
0-BELZAK BL-50 in New Jersey The Belzak Corporation
on sale beta sodium glucoheptonate 5
solution) and Na 4 E DTA were mixed, water was then added to the resulting mixture to form a volume of IJ, and the mixture was stirred. The concentrate that formed was clear, homogeneous, and had a cloud point of 130'F.

A washing aqueous solution was prepared by adding the above concentrated solution to water at a concentration of 2 volumes. The resulting cleaning solution had the following composition:

KOH1,72VI N a , i E D T A
2.00 μTRITON DF-200,61
F/Beta Na Glucoheptonate
A 0.65 M aqueous wash solution was used to treat ten 3004 alloy aluminum cans coated with aluminum strips and drawing oil.

The aluminum cans were treated as follows.

(a) The above cleaning solution was maintained at 110°F and sprayed for 30 seconds.

(b) Immersed in cold water for 30 seconds and rinsed with water.

(C) After standing for 30 seconds, drainage was tested on both the inner and outer surfaces.

(d) Wipe the inside with a clean white cloth and test the aluminum strip with iron blood.

All aluminum cans were free of water and aluminum strips.

An additional 10 cells were processed and tested as above, except that the cans were allowed to stand for 7.5 minutes after step (λ).

The iron mine was clean and showed no signs of discoloration. The can was then processed through steps (b) to (ψ) above and the entire can was free of discoloration, dripping and aluminum flakes.

Examples 14-18 Example 14 NaOH1,00VI Na 4 E DT A
2. OOIPLURAFACD-250,61 Beta Na Glucoheptonate 0
65Vl Example 15 NaOH1,0OVI! N a 4 E DT A
2. OOVISURFACTANT AR15Q
Q, 511/Beta Na Glucoheptonate 0.65 V! Example 16 Na011 11111
W fN a 4 E D T A
2. OOVIPLURONIC31R1O,
61ti//l Beta Na Glucoheptonate
o65Vl! Example 17 NaOH1,OOV/! N a 4 E DT A
2. OO97TRITON DF-200,615M/
MIRAWET B 0.46
VI! Beta Na Glucoheptonate
0,655/Example 18 Na OH1,00VI Na 4E DT A 2
．． OOVISURFACTANT AR1500,61
μ Beta Na Glucoheptonate
0.65 Vl! Each of the above aqueous cleaning solutions was used to treat ten 3004 alloy aluminum cans covered with aluminum strips and drawing oil.

The aluminum cans were processed as follows.

(-) The above cleaning solution was maintained at 110'F and sprayed for 30 seconds.

(b) Immersed in cold water for 30 seconds and rinsed with water.

(c) After standing for 30 seconds, drainage was tested on both the inner and outer surfaces.

(ψ Wipe the inside with a clean white cloth and test the aluminum strip with iron blood.

All cans treated with all of the above cleaning solutions were free of drainage and aluminum debris.

Ten additional cubes were treated and then tested with each wash solution as above, except that the cans were allowed to stand for 7.5 minutes after step (-). All cans were clean and showed no signs of discoloration. The can is then subjected to the above steps (b) to
All cans processed through (d) and from all cleaning solutions were free of discoloration, drainage and aluminum flakes.

Patent applicant Amgam Products Incorporated Representative Patent Attorney Aoyama Hajime and 1 other person

Claims (1)

Claims: 1 about 05-32/l alkali metal hydroxide, about 1-5
p/l of an alkali metal salt of ethylenediaminetetraacetic acid, and about 0.01 to 0.7/l of a surfactant [main agent], which removes, kneed, dissolves and lubricates aluminum flakes from the aluminum surface. Cleaning aqueous solution, for cleaning oil. 2. The solution of paragraph 1 above also containing about 0'5 to 1 OY/l of an aluminum sequestering agent. 3. The solution of item 2 above in which an aluminum sequestering agent of about 06 to 3'771 is present; 74. The aluminum sequestering agent is sorbitol, alkali curconate & salt, alkali metal glucoheptonate, or The solution of item 2 above which is an alkali metal salt of tartrate - 5 alkali metal hydroxide is present at about 1 to 2 Vl and an alkali metal salt of ethylenediaminetetraacetic acid is present at about 15 to 2 Vl.
The solution of paragraph 1.2.3 or 4 above, present at 3 Vl. 6. The solution according to item 5 above, wherein the alkali metal hydroxide is potassium or sodium hydroxide, and the alkali metal salt of ethylenediaminetetraacetic acid is a disodium, trisodium or tetrasodium salt. 7. The solution of item 5 above, wherein the surfactant is TRITON I) F-20. 8 Surfactant or TRITON 1) F-20, pi, (
)RAI・A(.D-25,5URF'ACTANT ARI50.PL
LJRO\IC31RI, DingRITON DF-20
and 2-butyne ethoxyacetic acid alkali metal salt, and 5UkFACTAN'r AR15Q and 5U
The composition of paragraph 1.2.3 or 4 above selected from the group consisting of RFOL® ICLF17 (7) combinations. 9. Surfactant or TRITON 1) L which is F-20
Solution of item 8 above. 10 surfactants or about 0.2 to 2.0! , l. 11, about 25-250 f/l alkali metal hydroxide, and about 0.3 per part by weight alkali metal hydroxide.
A method for removing and dissolving aluminum flakes from aluminum surfaces and dissolving lubricating oil, characterized by containing 3 to 10 parts by weight of an alkali metal salt of ethylenediaminetetraacetic acid and about 0.033 to 20 parts by weight of a surfactant. An aqueous concentrate used to formulate aqueous cleaning solutions for cleaning. 12. The aqueous concentrate according to item 11 above, wherein the alkali metal hydroxide is potassium or sodium hydroxide, and the alkali metal salt of ethylenediaminetetraacetic acid is a disodium, trisodium or tetrasodium salt. 13. No. 11 above, wherein the alkali metal salt of ethylenediaminetetraacetic acid is present in an amount of about 0.5 to 6 parts by weight, and the surfactant is present in an amount of about 0.067 to 4 parts by weight, per 1 part by weight of the alkali metal hydroxide. Or the aqueous concentrate described in Section 12. 14, about 0.17 per part by weight of alkali metal hydroxide
~29 parts by weight of an aluminum sequestering agent 15, along with the aqueous concentrate of paragraph 14 above, in which about 0.20 to 2.6 parts by weight of an aluminum sequestering agent is present; , an alkali metal tartrate, an alkali metal gluconate, or an alkali metal glucoheptonate, the aqueous concentrate according to item 14 above. 17. Surfactant is TRITON DF-27), PL
tJRAFACD-25,S[FACTANT ARK
50, P LURON I C31R1, TR
Combination of ITON DF-20 and 2-butoxyethoxy vinegar, acid alkali metal salt, and 5URFACTANT
The above-mentioned No. 11゜12.14.15 selected from the group consisting of the combination of AR15Q and S[JRFONICLP01
Or the aqueous concentrate described in Section 16. 1B, the aqueous concentrate according to item 17 above, wherein the surfactant is TRITON DF-20. 19 Surfactant TRITON DF 20 Thea 6
The aqueous concentrate according to item 13 above. 18. The aqueous concentrate of item 17 above, wherein the surfactant is present in an amount of about O12 to 2.0 fj/l. 21. (a) The aluminum surface was coated with about 0.5 to 31/l of alkali metal hydroxide, about 1 to 59/l of alkali metal salt of ethylenediaminetetraacetic acid, and about 0.1 to 1
1. A method for cleaning an aluminum surface, comprising the steps of: (b) rinsing the cleaning solution from the aluminum surface; 22. The method of item 21 above, which also contains an aluminum sequestering agent with a washing aqueous solubility i of about 05 to 10' i/l. 23. Surfactant or TRITON DF-20, PL [
JRAFACD-25,5URFACTANT AR1
50, PLURONIC31R1, TRI”rON D
A combination of F-20 and alkali metal salt of 2-butoxyethoxyacetic acid, and S[JRFACTAN AR150
and 5URFONICLP01. 24. The method of item 23 above, wherein the surfactant is RITON DF-20. 25, the surfactant is about 0.2 to 2. The method of paragraph 23 above, present in OP/l. 26. The method of paragraph 21 above, wherein the cleaning solution temperature is maintained in the range of about 80-15"F. 27. The method of paragraph 21 or 22, above, wherein the aluminum surface is an aluminum can. 28. Aluminum sequestering agent. The second above, which is norbitol, an alkali metal salt of gluconic acid, an alkali metal salt of glucoheptonate, or an alkali metal salt of tartrate.
Method 2. 29J0.6~1.3 F! /l of aluminum sequestering agent is present. Method 030 of Section 2, in which the wash solution contains about 1 to 2 f/l of potassium or (sodium hydroxide) and about 1.5 to 39 f/l of the disodium, trisodium, or tetrasodium salt of ethylenediaminetetraacetic acid. and the cleaning solution temperature is about 90~
31. The method of paragraph 28, wherein the cleaning solution contact time is from about 10 seconds to about 2 minutes.