DK145974B - CLEANER FOR SURFACES OF ALUMINUM OR ALUMINUM ALLOYS - Google Patents

Description

(19) DENMARK

| J | (12) PUBLICATION MANUAL OR U5974B

DIRECTORATE OF THE PATENT AND TRADEMARKET SYSTEM

(21) Application No. 4737/74 (51) Int.CI.3 C 11 D 7/06 (22) Filing Day 6. s ep. 1974 (24) Race Day 6. s ep. 1974 (41) Aim. available Mar 8 1975 (44) Submitted May 2, 1983 (86) International Application No. - (86) International Filing Day (85) Continuation Day - (62) Stock Application No. -

(30) Priority Sep 7 1973 * 7312217 * SE

(71) Applicant NORDTEND SHARE COMPANY, S-126 11 Stockholm 52, SE.

(72) Inventor Barbro Sylvia Irene Lueborg, SE.

(74) Plenipotentiary Danish Patent Office ApS.

(54) Detergent for aluminum or aluminum alloy surfaces.

The present invention relates to a cleaning agent for aluminum or aluminum alloy surfaces.

It is known that aluminum and most light metal alloys are attacked more or less by most medium strengths and by all highly alkaline chemicals, except by ammonia, but only slightly by weak

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alkaline detergents. In industrial grills, whose inner F "- usually made of aluminum plates and parts, has

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^ Compositions of surfactants, complexing agents and silicates used hitherto as detergents, in particular metasilicate. However, at the required high silicate content, precipitates are obtained which make the grill ovens flame ^ by silicate coatings on the aluminum surfaces. At low content of

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or without metasilicate, the purification effect becomes poor.

2 145974

The present invention avoids the above disadvantages.

While working to find appropriate inhibitors to reduce the attack of commonly used alkaline detergents on aluminum surfaces, it has surprisingly been found that already a relatively small addition of alkali metal salts of unsaturated fatty acids prevents the attack of aqueous solutions of potassium or sodium hydroxide very effectively. saturated fatty acids. In this regard, very satisfactory results exhibit oleic acid, linoleic acid, tall oleic acid and ricinolic acid, to name a few of the most common unsaturated fatty acids. In comparison, salts of saturated fatty acids such as palmitic acid, α-sulfopalmitic acid, sebaceous fatty acid, lauric acid, coconut fatty acid, and archaic acid did not act as inhibitors. Table 1 shows a representative selection of tested compositions of detergents showing the ratio of the active components, alkali and inhibitors. It is also clear from the table how the presence of sodium urea polyphosphate (STPP), nitrilotriacetic acid (NIA), ethyl endiaminetetraacetate (og) and metasilicate (Meta) works. These substances should therefore be omitted without additives. MEA stands for monoethanolamine.

Table 1% Alkali pH% Inhibitor Type Inhibitor. Aluminum Corrosion.

The alkali salt of Time 15 min; temp.

70 ± 5 ° 0 0.1 ΕΌΗ 12.0 - - strong attack 0.25 "12.3 -" "0.5" 12.6 - - very strong attack 0.5 "" 0.25 tall oleic acid no attack 0 , 5 "" 0.125 "" 0.5 "" 0.075 "" "" 0.5 "" 0.025 "" tendency to attack 0.5 "" 0.5 palmitic acid strong attack 0.5 "" 0.25 "" " "0.5" "0.1" "" "0.5" "0.5 α-disulfopalmi- very strongly attacked tin acid 0.5 M n 0.25" "attack 0.5" "0.1" 0 , 5 "" 0.05 "" "0.5" "0.5 α-monosulfopal- strongly attack mitic acid x__ ___.

145974 3 (continued Table 1) 0.5 ,60Ξ 12.6 0.25 α-monosulfopal strong attack mitic acid 0.5 "" 0.1 "" "" 0.5 tr "0.05" ", r" 0 , 5 "" 0.25 tallow fatty alcohol attack very strongly 0.5 "" 0.25 1,2-dicarboxylic acid "0.5" "0.5 lauric acid strongly attack 0.5" "0.1" " attack 0.5 "" 0.05 "0.5" "0.5 coconut fatty acid strongly attack 0.5" "0.25" "" "0.5" "0.1" "" "0.5" " 0.05 "11" «0.5" "0.5 erucic acid very strongly attack 0.5" "0.25" "" "" 0.5 n "0.1" "" "" 0.5 "" 0.05 "" "" "0.5" "0.25 oleic acid no attack 0.5" "0.1" "0.5" "0.05" "" 0.5 "" 0.25 linoleic acid 0 5 "" 0.1 "" "" 0.5 "" 0.05 "" "" 0.5 "" 0.25 castoric acid 11 11 0.5 "" 0.1 "" n "0.5" "0.05" "" "0.5 UaOH" 0.05 tall oleic acid "" 0.5 "" 0.025 "" tendency to attack 0 ^ 25 ko !?} "0> ° 5" "no attack 0.25 ITaOHl η p -7 q qc 11 tt tt η 0.25 ME4 J p 0.25 ITaOH * \ ηρ y, Λ It It It tt 0.25 TJH ^ OHf ° 'ϋρ 0.25 KOH \, 2 7. O 06 n "11" 0.25 M4OEυ »υρ O'M S ^ CoV2-4 ° - ° 5” O'M Møfa} 12'6 ° - ° 5 "" Undo!) 4 θ'25 12.2 0.05 tall oleic acid strong attack 145974 (continued Table 1)

0.25 KOH \ Il r \ pr II II II II

0.25 steps; 0.25 KOH ii λ π n 11 it it

0.25 STPPJ

0.25 KOH λ II η ft It II II tt 0.25 sipp; 0.25 KOH \ II η u "· *" 0.1 stpp; ^ 0.25 KOH \ ip (z / -) / -) c 11 11 11 11

0.25 MLJ '' P.

0.25 KOH'l II (~ v pc II It II It 0.25 NTAj u, ° 0 »25 K0H" \ II r \ nr II If It It 0.25 EKDAj U, Up

0.25 KOH λ „r. Pc II II II II

0.25 EDTAJ U '° 0.25 KOH \ ii n 9 M n π n 0.25 Metaj 0 ^ 14 ΚΟΞΞ) 13 ° i ° 75 "" no attack 0.7 KOH 13.0 0.35 "" " "1.4 KOH 13.5 0.7" ""

The detergent according to the invention is characterized in that, when used in addition to water as a diluent, it contains one or more alkali metal hydroxides, preferably sodium and / or potassium hydroxide, at a concentration of 0.1 to approx. 2% by weight and addition of at least 0.02% by weight of an alkali metal salt of unsaturated fatty acid acting as an inhibitor.

If the agent is to be used diluted with hard water, it is convenient for this to add sebum fatty alcohol with 11 moles of ethylene oxide, since the ethylene oxide product already acts in small quantities as a lime soap dispersant and affects the foam which is significantly reduced.

The detergent according to the invention is advantageously used at temperatures above room temperature, e.g. about 70 ° 0 when cleaning grills. Even at boiling point temperature, the detergent of the invention can be used without dissolving aluminum, despite its pH being between 12 and 13.