DE1287720B - - Google Patents

Description

The invention relates to a surface-stable mixture for use in alkaline Baths for cleaning metal objects. The mixture is characterized by an increased Cleaning effect.

Alkaline detergents are used in the industry for cleaning metal, glass, certain Plastics and the like used to the greatest extent. First and foremost, they are used to prepare Metals, such as steel, brass and copper, for plating, painting, enamelling, rustproofing, Approaches and other operations. Among other things, it depends on the removal of various Types of contamination, for example from cutting oils, grinding aids, Stamping, deep drawing, polishing, rust inhibitors, lubricating greases and various types of dirt at. The alkaline cleaning solutions are used in immersion, spray or electrolytic cleaning used. Cleaning in the immersion tank is the most common and therefore the most important.

In this latter method, the object to be cleaned is usually immersed in a hot alkaline solution with little or no liquid movement or is slowly stirred through it. The cleaning solutions used are generally prepared from substances soft between about 88 to 99 percent by weight of various alkalis, such as caustic soda, sodium melasilicate. Sodium carbonate, trisodium phosphate, sodium polyphosphate, sodium orthosilicate, telrana irium and tetrapotassium pyrophosphate, and contain about 12 to 1 percent by weight of a surfactant. So far, alkylarylsulfonates and resin soaps have been predominantly used as surface-active substances for this purpose. The concentration of the substances consisting of alkali plus surfactants in the tank solution is generally kept at 2 to K) ¹ Vo of the cleaning solution.

Just like oil, Feit and other dirt being removed from the object to be cleaned in the tank a foam-like layer collects on the surface of the bath. If the applied surfactant is not really soluble in the hot alkaline solution. also this one tends Substance to accumulate in the described surface layer. Will the accumulation of foam so large on the surface that it will remove the already cleaned piece when it is removed from the bath if it is coated again, one must on the surface of the liquid skim off the dirt and undissolved surfactant. With every such Surgery will inevitably remove a significant amount of surfactants from the system removed, so that the concentration of the bath of effective cleaning agents finally very prematurely drops so far that it no longer works satisfactorily. It is therefore obvious to overcome this do not tend to discolour. So far, technology has not known any cleaning agents that are highly effective metal cleaners Una are also these aforementioned four Unite properties.

The present invention is now an unusually effective metal cleaner, which has all of the above properties to an unusually high degree.

The new cleaning agent consists of a mixture of about 65 to 95 percent by weight of phosphated Compounds of the general formula I

R (CH ₂ CH ₂ O) ₁ H

or a salt thereof and 35 to 5 percent by weight of a compound of the formula II

R ₁ (CH ₂ CH ₂ O) XH ₂ CH ₂ NR ₂

In the formulas, R and R ₁ denote alkoxy groups with 10 to 15 carbon atoms or alkylphenoxy groups with 4 to 10 carbon atoms in the alkyl radical, R ₂ and R_, either hydrogen atoms or lower alkyl groups with a total content of 1 to 7 carbon atoms and χ a number from about 5 to about 25 and ζ a number from about 4 to about 25. The phosphating of the compound of the formula I is preferably carried out with the aid of polyphosphoric acid, but optionally also with orthophosphoric acid, phosphorus peroxide, phosphorus dichloride. Phosphorus oxychloride and the like

The favorable combination of the required properties given above is only achieved by such Mixtures realized light in which the specified amounts and ratios of the two components rule. These critical mixing ratios of the components were not suggested and could not cannot be derived or predicted from knowledge of the properties of the individual components. Rather, each component has certain disadvantages on its own, which they have for the task at hand just can't hold on to qualify. For example, the phosphazene component is indeed Very soluble in hot alkaline solutions and satisfactory on alkali and in alkaline solutions stable, but it is by no means an effective cleaning agent. In contrast to this is the other component with the amino end group it is an effective one Detergent and also has stability, but isl Not sufficiently soluble in built-up alkaline solutions. However, if you mix these two components in the specified proportions, the mixtures are very effective cleaning agents, which are highly soluble in concentrated hot alkaline solutions and on alkali and in alkaline Solutions are stable.

The presence of the divalent phosphorus end group in one component confers the

Difficulty only such surface-active sub- <> o cleaning agents the F.rfindiing the desired solution

to use punches, which are soluble in hot alkaline solutions.

In addition to solubility in hot alkaline solutions, stability on solid caustic and other alkalis *> 5 and stability in strongly alkaline solutions are also important for alkaline cleaning agents. Furthermore, it is desirable that the substances on solid caustic alkali and other alkaline substances have a high degree of stability and stability that cannot be achieved by other anionic components with sulfate, sulfonal or carboxyl groups. In the case of the second component, the end group closure with the amino group is of decisive importance both for the stability on caustic alkalis and the good cleaning effect. Mixtures of the first component with non-ionic compounds without end

group closure, for example alkylphenoxypolyethoxy compounds, prove to be unstable and do not give a satisfactory cleaning effect. Mixtures with non-ionogenic compounds, their End groups are ainidated or esterified are lacking the stability on caustic alkalis and have as a cleaning agent only dubious value.

Table I below shows a comparison the performance of the cleaning mixture according to the invention, the individual components thereof Mixture, various much-used upper

Cleaning mixture according to the invention:

IO

surface-active substances and substances whose chemical composition is somewhat analogous to the components of the present invention. One recognises without further ado that all preparations B to J, which are outside the invention, compared to the inventive Mixture A are absolutely unsatisfactory because they are either difficult to dissolve in caustic alkalis, have poor cleaning effect on solid caustic alkali or are unstable in caustic solutions or combine several of these properties. The following products were tested:

Λ. 8 parts C ₈ H ₁₇

--0 (CH ₂ CH ₂ O) ₁₀ PO ₃ H ₂

+! Parts QH ₁₇ -> - 0 (CH ₂ CH ₂ O) ₁₅ CH ₂ CH ₂ N (CH ₃ I ₂ comparative components:

B. C ₈ H ₁₇ -,: - O - (CH ₂ CH ₂ O) ₁₀ PO ₃ H,

C. QH ₁₇ -

- O (CH ₂ CH ₂ O) ₁₅ CH ₂ CH ₂ N (CHJ ₂

D. Na dodecyl sulfonate.

E. C ₈ H _n -v. r - O - (CH ₂ CH ₂ O) ₁₀ H

F. Tall oil soap.

G. Salt of a sulfonated oxäthylienen ICiL-C ₁₂ -C ₁₅ -AnIiHs (aliphatic).

H. Commercially available phosphated nonionic surfactant.

I. Phosphazenes, nonionic surface-active agent made from Oetylphenoxy- (polyethoxy) -! 1.5-EthanoI and P ₂ O ₅ according to USA.-Palen 3 004 056.

J. iMa-dodecvidiphenyl ether disulfonate.

K. Blind Trial.

To determine the cleaning effect, steel sheets that have been pre-cleaned with solutions are cleaned with mineral oil. The bleach is allowed to rotate for 5 minutes at 28 revolutions per minute on a bath heated to K2 C, which contains 5% of a base (made from 40.0 ° Ό NaOH, 28.5% T-Ja ₂ CO. ,, 31.5 % Sodium metasiiicate · 5 H ₂ O) and 0.1% active cleaning agent to be tested. The values given in the table represent the average percentage of clean area on both sides of three sheets. To test the stability to caustic alkali, 2 "Ό surface-active substances are mixed on crystal groups of caustic soda and left to stand in open cans for 2 to 3 weeks at 60 C. The cleaning effect is determined before and after cleaning to ensure stability

determine.

For testing the stability in caustic solutions

becomes 1% surfactant in a 5 to 10 ", (caustic alkaline solution 2 to 3 weeks for 60 C and measured before and after storage of the cloud points.

To determine the discolourability, 2 " ₀

Surface-active substance mixed with crystal flakes of caustic soda and kept at 25 C for at least 1 week kept in a sealed container for a long time.

solubility

maximum "/ _u NaOH

for Γ'ίι product

lid 60 to KiO C

10.5

15.0
0

Ueiiiigiingsvvirki.nl!

cleanser

H) O

30th

100

Tabel

Stability aiii NaOIi read

no loss no loss no loss stability in
NaOH I solution

stable
stable
stable

VeiΊϊίιlinn ;. ';. ::! '
solid NaO! I.

very weak

no

very weak

continuation

product solubility
maximum% NaOH
for 1% product
at 60 to 100 ° C Cleaning effect
cleanser Stability on
NaOH solid Stability in
NaOH solution Discoloration on
solid NaOH D. 4.0 38 no loss stable no E. 0 100 great loss stable considerably F. 4.0 0 great loss stable no G 5.5 100 some loss unstable considerably H 7.7 13th no loss stable very weak I. 6.7 21 stable - J 18.0 18th stable - K 0 -

No clear solution at 60 to 100 C in water (% NaOH).

The critical minimum ratios for the cleaning agent of the invention result from fact 20
thing that blends with less than 5% of the
Component II with the amino end group have an insufficient cleaning effect and that
Mixtures with more than 35'V _{0 of} this component
have insufficient solubility of the end product in built-up solutions. So is. meant that these mixtures to lOO'C in 5'V _n caustic found no clear solution in the range 60 seconds. Table II below shows the great importance of the disclosed mixing ratios of the cleaning agent of the invention. The mixtures listed in Table II consist of the following individual components:

Mixture according to the invention:

A. C ₈ H ₁₇ - ^ I3 ^ ^O ~ (CH ₂ CH ₂ O) ₁₀ PO ₃ H ₂ / C ₈ H ₁₇ comparative mixtures:

B. C ₈ H ₁₇ - ^ ~ V "° - (CH ₂ CH ₂ O) ₂₀ PO ₃ H ₂ / QH ₁₇

0- (CH ₂ CH ₂ O) ₁₀ PO ₃ H ₂ / C ₈ H _n 0- (CH ₂ CH ₂ O) ₁₀ PO ₃ H ₂ / QH ₁₇ 0- (CH ₂ CH ₂ O) ₁₀ PO ₃ H ₂ / QH ₁₇ 0- (CH ₂ CH ₂ O) ₁₀ PO ₃ H ₂ / QH ₁₇ )) ₇₅ PO ₃ H ₂ / QH ₁₇ H. C ₈ H ₁₇ -e > - O - (CH ₂ CH ₂ O) ₁₀ PO ₃ H ₂ / QH _n

(CH ₂ CH ₂ O) ₅ PO ₃ H ₂ / QH _n O- (CH ₂ Ch ₂ O) ₁₀ PO ₃ H ₂ ZQH ₁₇

V Ns r \ (CU CU Π \ DO 14 / C U P

- (CH ₂ CH ₂ O) ₁₀ PO ₃ H ₂ / QH ₁₇ > - (CH ₂ CH ₂ O) ₁₅ CH ₂ CH ₂ N (CH ₃ ) ₂

- O - (CH ₂ CH ₂ O) ₁₉ CH ₂ CH ₂ N (CH ₃ ), O- (CH ₂ CH ₂ O) ₁₉ CH ₂ CH ₂ N (CH ₃ J ₂ > - (CH ₂ CH ₂ O) ₁₉ CH ₂ CH ₂ N (CH ₃ J ₂ ) - (CH ₂ CH ₂ O) ₁₅ CH ₂ CH ₂ N (CH ₃ ) ₂ • O - (CH ₂ CH ₂ O) ₁₅ CH ₂ CH ₂ N (CH ₃ ), ■ O - (CH ₂ CH ₂ O) ₁₅ CH ₂ CH ₂ N (CH ₃ J ₂ O - (CH ₂ CH ₂ O) ₉ CH ₂ CH ₂ N (CH ₃ J ₂ O - (CH ₂ CH ₂ O) ₉ CH ₂ CH ₂ N (CH ₃ J ₂ O - (CH ₂ CH ₂ O) CH ₂ CH ₂ N (CH ₃ J ₂ O - (CH ₂ CH ₂ O) ₁₅ CH ₂ CH ₂ NHCj ₁ H ₁₇

Q- C ₁₂ H ₂₅ - / Vo- (CH ₂ CH ₂ O) ₈ POjH, / C ₁₂ H ₂₅ -ί \ - O- (CH ₂ CH ₂ O) ₄ CH ₂ CH ₂ N (CH ₃ ),

KC ₈ H ₁₇ - / Vo- (CH ₂ CH ₂ O) ₁₀ PO ₃ H ₂ C _x II ₁₇ - / (CH ₂ CH ₂ O) ₁₀ H.

Mixtures according to the invention:

L. QH ₁₇ - VO- (CH ₂ CH ₂ Oi ₁₁₅ PO ₃ H ₂ / C ₈ H ₁₇ -;

O (CH ₂ CH ₂ O) ₁₅ CH ₂ CH ₂ NHC ₄ H ₁ ,

N. G, H _U - > ~ 0 - "(CH ₂ CH ₂ O) ₁₀ PO ₃ H ₂ / QH _n -

V - O - (CH ₂ CH ₂ O) ₁₅ CH ₂ CH ₂ N (CH ₃ J ₂

O. CH ₁₂ -

(CH ₂ CH ₂ O) ₁₁₁ PO ₃ H ₂ / QH ₁₇ > O (CH ₂ CFi ₂ O) ₁₅ CH ₂ CH ₂ N (CH ₃ J ₂

P. C ₉ H ₁₂

O- (CH ₂ CH ₂ O) _12K PO ₃ H, G, H ₁₁ ,> - O - (CH ₂ CH ₂ O) _{n 8} CH ₂ CH ₂ N (CH,) ₂

In the cleaning test in Table II, a value i _{5 applies}
of 85 or above as wearable. All values for the
Cleaning efficiencies were determined before the stability tests were carried out. After the stability tests were carried out, cleaning tests were carried out again to determine which 20
Effect of the treatment with caustic alkalis on the
The cleaning power of the mixtures. So showed
For example, component mixture A in a mixing ratio of 80:20 after 2 to 3 weeks
Store on solid caustic alkali at 60 C no change 25
of the previous 100% cleaning effect on one
Basis O,! "■■,) active cleaning agent. If the test is made stricter by using only 0.03% surface-active substances, then according to the

Treatment with caustic alkali did not noticeably change the previously observed cleaning effect of about 90%.

In contrast, the component mixture K shows which because of the lack of the amino end group the one component outside the scope of the invention at a mixing ratio of 80:20 is the poor cleaning value of 73. A mixture of the same component in proportion 70:30 gives a cleaning value of 83 on the basis of 0.1% surfactant, the but drops to 42 after the mixture has been in contact with caustic alkali at 60 C for a week has held.

Components

of
Mixture

III

O K

100: 0
60:40
80:20
80:20
80:20
80:20
80:20
80:20
30:20
80:20
80:20
80:20
80:20
80:20

Table II

solubility
"/" NaOH

Cleaning effect

Stability on NaOIl solid Stability in
NuOH solution

Discoloration on solid NaOH

A. 95: 0 12.5 A. 90:10 11.6 A. 80:20 10.5 A. 70:30 10.0 L. 80:20 10.5 N 80:20 10.7 O 80:20 10.7 P. 80:20 10.8

Cleaning mixtures according to the invention:

93 no loss

100 no loss

100 no loss

100 no loss

100 no loss

97 no loss

92 no loss

89 no loss

Yes very weak Yes very weak Yes very weak Yes very weak Yes very weak Yes very weak Yes very weak Yes very weak

Comparative cleaning mixtures:

15.0

4.0

9.5

11.0

9.9

10.5

12.8

11.5

12.5

11.1

12.5

12.9

6.0

8.8

30th

100

99

100

100

KK)

100

100

99

88

45

76

24

73

no loss no loss no loss no loss no loss no loss no loss no loss no loss no loss no loss no loss no loss some loss yes
Yes
Yes
Yes
Yes
F- yes
Yes
Yes
Yes
Yes

Yes
Yes

no

very weak very weak very weak very weak very weak very weak very weak very weak very weak

moderate

909 504/1837

Claims (1)

Also cleaning mixtures from component A in a mixing ratio of 100: 0 and 60:40 as well furthermore, mixtures which contain the components J, M and Q are just outside the limits of the mixing range of the invention, and each of them is characterized by unsatisfactory cleaning performance or poor stability against caustic alkalis and poor solubility in sodium hydroxide solution. The new cleaning agents according to the invention can be produced according to a first method by that the nonionic phosphate and the nonionic amine are each prepared separately and then mixed together. A second preferred method is to mix one first nonionic compound and the nonionic amine and then phosphates the mixture. This has the advantage that all of the hydroxyl groups still contained in the nonionic amine are closed by the phosphating. The good stability of the mixtures on solid caustic alkali depends on a practically complete closure of all hydroxyl groups. When working according to the first method, a mixture of 1 mole of nonionic surface-active compound and about 1 to 2 moles of polyphosphoric acid is first heated to about 80 to 110 ° C. until the cloud point in the caustic solution no longer rises. It is preferred to work with about 1.0 to 1.3 moles of polyphosphoric acid per mole of nonionic compound. The stated number of moles of polyphosphoric acid is based on the proportion of phosphoric anhydride, expressed as a percentage of P ₂ O ₅ , in the polyphosphoric acid. A more complete description of the nature of this manufacturing method and the products resulting therefrom is laid down in a separate invention of the same day. The phosphated product obtained in this way is then mechanically mixed with the amine component, which in turn has been prepared from the desired nonionic surface-active agent by one of the numerous known processes. For example, for this purpose the surface-active agent can first be reacted with thionyl chloride and the product obtained in this way can then be reacted with dimethylamine. The phosphated product can of course also be prepared by other known methods with phosphating _{agents, such as P 2} O ₅ , POCI ₃ , H ₃ PO ₄ and PCl ₃ , using different molar ratios and reaction conditions and in varying quality. According to the preferred second method, the nonionic surface-active compound and the Surface-active compound with amino end groups mixed together and the mixture at 80 to 110 C phosphated with polyphosphoric acid. Again, as with the first method. about 1 to 2 moles, preferably 1 to 1.3 moles, of polyphosphoric acid for each hydroxyl equivalent present be applied. Larger amounts of polyphosphoric acid produce darker ones in both cases Products, however, are not required for complete endgroup closure. Lower amounts Polyphosphoric acid leads to incomplete end capping and generally requires prolonged heating if one is to complete the reaction. In principle, the other phosphating agents mentioned above can be used. If necessary, small amounts of an oxidizing agent, such as hydrogen peroxide, or a reducing agent such as hydrazine hydrate, before phosphating can be added to obtain lighter tinted products. The following examples illustrate some embodiments of the invention. For example, a cleaning mixture consists of about 88 to 99 percent by weight of an alkali metal salt and 12 to 1 percent by weight of a surface-active component, which in turn consists of about 75 to about 90% of a phosphated compound of the formula I and from about 25 to about 10% of one Compound of formula II as viewed. . .
example 1 To a stirred mixture of 207.5 parts (0.246 mol) of an oxethylated p-lert.-octylphenol (hydroxyl number 66.4, corresponding to molecular weight 843), 65 parts of the corresponding dimethylamine (prepared by reacting a similar oxethylated octylphenol with thionyl chloride and subsequent reaction with dimethylamine in the presence of alkali, with neutral equivalent 893, corresponding to a conversion of 94.5%) and 10 drops of 30% hydrogen peroxide are set in a nitrogen atmosphere within 30 minutes, while the temperature rises to 50 "C, 52.8 parts (0.312MoI as P ₂ O ₅ ) of a 115% ortho-equivalent polyphosphoric acid (82 to 84% P ₂ Oj). The mixture is then gradually heated to 105 ° C. for a further 90 minutes and stirred at 105 to 110 for a further 530 minutes "C, while the cloud point in 12% aqueous sodium hydroxide solution rises gradually and finally stops at 74 C. The shade of the reaction product is 12 on the VCS scale. Example _ To a stirred mixture of 709 parts (1.152 mol) of an oxethylated p-tert-octylphenol (hydroxyl number 91.2, corresponding to molecular weight 615), 230 parts of an oxethylated p-tert-octylphenol terminated with a dimethylaminoethyl end group (prepared according to Example 1 from an oxyethylated p-tert-octylphenol with a molecular weight of 819, with a neutral equivalent of 864, corresponding to a purity or conversion of 97.9%) and 1.88 parts of 30% strength hydrogen peroxide solution, 245 parts (1.449 Mol as P ₂ O ₅ ) of the polyphosphoric acid of Example I, while the temperature rises and is adjusted to below 50 C. The mixture is then gradually heated to 105 "C for a further 90 minutes and stirred for a further 4 hours at 105 to 110" C, while the cloud point in 14% aqueous sodium hydroxide solution rises gradually and finally stays at 58 ° C. The color of the product is the same as in the example! 1. Alkali-stable and soluble, surface-stable mixture based on phosphated glycol ether derivatives in an alkaline medium for cleaning metal counter-surfaces, characterized in that that the mixture of about 65 to 95 percent by weight of a phosphated Compound of the general formula R (CH ₂ CH ₂ OkH (D or its salt and about 35 to 5 percent by weight of a compound of the general formula Ri (CH ₂ CH ₂ O) XH ₇ CH ₂ N - R ₂ (II) where R and R _{1 are} alkoxy groups with 10 to 15 carbon atoms or alkylphenoxy groups with 4 to 10 carbon atoms in the alkyl radical, R ₂ and R _{3 are} hydrogen atoms or lower alkyl groups with a total content of 1 to 7 carbon atoms and χ is a number in the range from about 5 to about 25, ζ means a number in the range from about 4 to about 25.