DE2149138B2 - Corrosion-inhibiting antifreeze and anti-corrosion agents for antifreeze - Google Patents

Description

in which X and Y are a nitrogen atom or the group CR *, where X and Y do not simultaneously denote a nitrogen atom or the group CR ⁴ , and R ¹ to R ^{4 are} identical or different and are hydrogen, an alkyl radical, a haloalom , the nitro or amino group, and η door the numbers 0.1. 2 or 3, and 10

2
1
I.

to 15

until

until

until

1 to
0.05 to

Parts by weight of sodium benzoate,
4 parts by weight of soda.
2 parts by weight borax.
1.5 parts by weight of sodium nitrite,
1.5 parts by weight of sodium nitrate and
1 part by weight of sodium silicate.

The invention relates to new corrosion-inhibiting antifreeze agents and their production and corrosion protection agents for antifreeze.

Water is used in an ever-increasing number of heat transfer systems and heat exchangers, z. B. automotive radiators and hot water heaters, used. Disadvantages are being in the cold .lahreszcit often above the outside temperature lying freezing point as well as its corrosive effect on the metallic surfaces of the heat transfer system.

To lower the freezing point, anti-freeze agents based on ..m glycols have been used proven and are commercially available.

It is known that iron alloys, such as. B. Cast iron and fluoro iron, corrode quickly in contact with water and in the presence of air. roast. It is also known that the rusting or corrosion of iron and other metals in water is favored by glycols. To prevent this corrosion is already a large number of Chemicals have been suggested for use as corrosion inhibitors, e.g. B. Soda. Borax, sodium nitrate, Sodium nitrite, sodium chromate, alkali salts of arsenic acid, arsenic acid, phosphorous Acid, phosphoric acid, alkali tungstates, but also alkali salts of weak acids, in particular of benzoic acid and butylbenzoic acid, and phenols, aliphatic and alicyclic as well as heterocyclic Amines, alkanolamines, especially triethanolamine and organosilicon compounds. Chino-Hn too has already been used as a corrosion inhibitor for zinc and galvanized steel sheets in acidic aqueous solution known (W. Wiederholt and J. Elze, Taschenbuch des Metallschutzes, 1960, p. 137.139). However, none is These substances are effective on their own, mixtures of several components have always been defined Composition proposed for practical use (German patents 1 154 976 and 1 176 930. German interpretative document 1 201 121). For the Corrosion protection in acidic aqueous solutions, e.g. B. pickling baths, are from the British patent 823 163 Mixtures known which, in addition to a nonionic surface-active compound, have a quaternized N-heterocyclic base and preferably contain an alcohol; as N-heterocycles. which to such quaternized bases can be implemented, inter alia, optionally by methyl groups methylated quinoline and isoquinoline mentioned.

In recent times, the increasing use of aluminum alloys and the Use of sealed cooling systems in automobile construction increased demands on the corrosion protection agents which relate to corrosion protection for light metal alloys and long-term effects. To meet the latter requirement, the addition of a Nitrophenols, preferably picric acid. suggested. None of the known agents offers the necessary corrosion protection for light metal alloys, so there is an obvious loophole and a real need here.

It is also known that a particular difficulty in the corrosion protection of cast metal bodies consists in the chemical composition of the cast body is not uniform everywhere. so that a common anti-corrosion mixture on different Dividing the casting has a very different and often insufficient effect. In the test one such a mixture is made a different one depending on the place where the sample is taken from the casting Corrosion and, if the result of the mixture is satisfactory, often outliers in the negative Sense firmly.

In the field of corrosion protection of heat transfer systems with water as the heat transfer medium So there is still considerable improvement possible and urgently needed.

It was found that the process for the production of corrosion-inhibiting antifreeze agents on the basis of glycols and their aqueous solutions can be significantly improved if

containing known corrosion inhibitors Antifreeze agents nitrogen heterocycles of the general formula

wherein X and Y stand for a nitrogen atom or the group C - R ⁴ , where X and Y do not simultaneously mean a nitrogen atom or the group C - R ^4. R ¹ to R ^{4 are} identical or different and represent hydrogen, an alkyl radical, a halogen atom, the nitro or amino group, and π represents the numbers 0, 1, 2 or 3, are added.

Examples of alkyl radicals R ¹ to R ⁴ are: straight-chain or branched alkyl radicals having 1 to 6, preferably 1 to 3 carbon atoms, such as. B. the methyl, ethyl, propyl, isopropyl, amyl and isoamyl radical, but preferably the methyl and ethyl radical.

Examples of halogen atoms (R ¹ to R ⁴ ) are: fluorine. Chlorine, bromine and iodine, but preferably chlorine and bromine.

Preferred compounds of the general formula I are quinoline, quinaldine, 2,4-dimethylquinoline, 2-chloroquinoline. 3-bromoquinoline. 4-chlorodiinaldine, 4,7-dichloroquinoline, 8-nitroquinoline, 2-methyl-8-nitroquinoline, 8-amino quinoline, 4-amino quinaldine. Isoquinoline. 3-methylisoquinoline, 4-bromoisoquinoline, 5-nitroisoquinoline and 5-aminoisoquinoline. Particularly Isoquinoline and 4-bromoisoquinoline are preferred.

In general, the compounds of general formula I should be in the aqueous solution of the antifreeze in an amount of 0.02 to 0.20 percent by weight. based on the total amount, but preferably in an amount of 0.03 to 0.10 percent by weight, to be available.

The corrosion inhibitors are usually added to the glycol, in particular the antifreeze, before the glycol or antifreeze is diluted with water or added to the aqueous heat transfer fluid. Therefore, the concentration of the corrosion inhibitor in the glycol or antifreeze must be higher to achieve the above-mentioned concentrations in the aqueous solution? \ I. In general, the compounds of general formula I are added to glycols or antifreeze agents in an amount of 0.04 to 1.0 percent by weight, based on the total amount of the glycol or antifreeze agent. but preferably in an amount of 0.06 to 0.5 percent by weight.

It is known that, as already mentioned, an optimal Corrosion Inliibicrcndc Or Corrosion Protection Effect not by a single corrosion inhibitor, but only by a mixture of different ones Corrosion inhibitors reached, the composition of which only within certain limits can be changed. This mixture or corrosion inhibitor system is to be referred to below as an anti-corrosion agent.

It has also been found that the crfindimgsgcmäß. Significantly improved effect on the known corrosion inhibitors in the corrosion inhibitors Aqueous solutions are obtained in particular if you follow what has been described above the antifreeze added a corrosion protection agent that the compounds of the general Formula I together with other known corrosion inhibitors and the following Composition has:

0.2 to 2 parts by weight of a compound of general formula 1,

5 to 20 parts by weight of sodium benzoate,
1 to 6 parts by weight of soda,
0.5 to 3 parts by weight of borax,
0.5 to 2 parts by weight of sodium nitrite,
0.5 to 2 parts by weight of sodium nitrate and
0.05 to 2 parts by weight sodium silicate.

In the aforementioned compounds, the sodium ion can be replaced entirely or in part by other alkali ions be replaced, e.g. B. by lithium or potassium ions. For example, can also be used be: potassium benzoate, potassium carbonate, potassium nitrite, potassium nitrate or equivalent Lithium compounds. In general, however, these are not compared with the sodium compounds preferred.

In general, this anti-corrosion agent is antifreeze in an amount of 1.5 to 18.5 percent by weight, each based on the total amount added; thereby the aforementioned content of 0.02 to 0.20 percent by weight of the compound of the general formula I in the resulting corrosion-inhibiting aqueous solution achieved.

However, a corrosion protection agent with the following composition is preferred:

0.3 to 1 parts by weight of a compound of

general formula I,

10 to 15 parts by weight of sodium benzoate,
2 to 4 parts by weight of soda,
1 to 2 parts by weight borax,
1 to 1.5 parts by weight sodium nitrite,
1 to 1.5 parts by weight of sodium nitrate and
0.05 to 1.0 parts by weight sodium silicate.

In general, this anticorrosive agent is added to the antifreeze agent in an amount of 3.0 to 13.0 percent by weight, based on the total amount, added; thus the above-mentioned becomes according to the invention preferred concentration of the compound of general formula I from 0.03 to 0.1 percent by weight the aqueous solution or from 0.06 to 0.5 percent by weight of the antifreeze.

Of course, it can be advantageous to use the anti-corrosion agent according to the invention, which is used as a such is only a mixture or mixture, already in the form before the use according to the invention a concentrate or a solution.

Advantageously, solvents are used which contain water or a glycol, in particular Ethylene glycol containing aqueous solution are miscible. Water itself and / or are preferred Glycols, especially ethylene glycol, are used. The concentration of the anti-corrosion agent plays a role here does not matter in these concentrated solutions, however, it is expediently chosen in such a way that that by mixing this preliminary solution with water or an aqueous solution containing glycols in one suitable mixing ratio according to the invention

Is
; r
η

az- ie
It,
he m

Final concentration of the anti-corrosive agent in the heat transfer fluid is reached, usually For this purpose, a mixing ratio is chosen that corresponds to a simple integer number ratio is equivalent to. For example, this pre-solution can have a 2 to 100 times higher concentration than have the heat transfer fluid.

For heat transfer systems (e.g. car radiators) that can cool below freezing point is the addition of an anti-freeze agent to the water, d. H. the use of aqueous solutions containing glycols absolutely necessary as a heat transfer medium. It is common to use these antifreeze add the necessary amounts of corrosion inhibitors or anti-corrosion agents. The concentration of the anti-corrosion agent in the anti-freeze is expediently According to the intended mixing ratio of the antifreeze with water. For example can be achieved by adding one part by volume of ethylene glycol to four to one part by volume of water achieve a lowering of the freezing point to -9 to -36 "C. It is preferred in Central Europe one part antifreeze based on glycols, in particular ethylene glycol, to two parts Water. As a result, the antifreeze is 5 to 2 times, especially 3 to 2.5 times that Amount of anti-corrosion agent added to the resulting aqueous containing the anti-freeze Should have heat transfer fluid.

An antifreeze or antifreeze is therefore also a concentrate or a preliminary solution of the corrosion protection agent in the sense of the above. The invention therefore also relates to antifreeze, the corrosion inhibitors of the general formula I according to the invention and those mentioned above Contain corrosion inhibitors of the composition according to the invention.

For example, such an antifreeze agent based on glycols, in particular ethylene glycol, 0.04 to 1.0 percent by weight nitrogen heterocycles of the general form! I and

1.0 to 10.0 weight percent sodium benzoate.

0.2 to 3.0 weight percent soda.

0.1 to 1.5 percent by weight borax,

0.1 to 1.0 percent by weight sodium nitrite,

0.1 to 1.0 percent by weight sodium nitrate and

0.02 to 1.0 weight percent sodium silicate.

Preferably contains an antifreeze based on glycols, in particular ethylene glycol, 0.06 to 0.5 percent by weight nitrogen heterocycles of the general formula I and

2.0 to 7.5 weight percent sodium benzoate

0.4 to 2.0 weight percent soda.

0.2 to 1.0 weight percent borax.

0.2 to 0.75 weight percent sodium nitrite.

0.2 to 0.75 weight percent sodium nitrate and

0.04 to 0.5 weight percent sodium silicate.

A particularly preferred antifreeze has the following composition:

0.2 percent by weight nitrogen heterocycles of the all-

common formula 1 and 4.00 weight percent sodium benzoate. 0.65 percent by weight soda.

0.35 percent by weight borax,
0.40 percent by weight sodium nitrite, 0.30 percent by weight sodium nitrate and 0.05 percent by weight sodium silicate

The remainder is monoethylene glycol.

In general, 1 part by volume of the antifreeze is used to prepare an aqueous heat transfer fluid diluted with 2 parts by volume of water. This achieves one for Central European winter temperatures sufficient lowering of the freezing point of the aqueous solution. In other areas there will be a lesser or greater dilution depending on the prevailing winter temperatures Select. Should the antifreeze only be used in such a way that deviates from the usual If dilution are used, other contents of corrosion inhibitors or corrosion protection agents in the antifreeze can also be preferred.

The then preferred contents can easily be determined from the preferred contents of the corrosion-inhibiting substances Aqueous solution of corrosion inhibitors of the general formula I or Calculate corrosion protection agent. The necessary conversion factors are known: dilution ratio, Densities of aqueous solutions containing water, ethylene glycol and ethylene glycol (see, for example, Am. Soc. 65, 13 096 [1943]). percentage Composition of the anti-corrosion agent.

The superiority of the novel corrosion inhibitors of the general formula I and of the anti-corrosion agents containing them compared to the previously used corrosion inhibitors and combinations are shown by the following examples.

The test is carried out analogously to ASTM Designation: D-1384-65, the American standard Society for Testing and Materials, generally applicable to the testing of corrosion inhibitors, in particular in antifreeze is recognized by the examples at the same time the superiority of the invention Corrosion inhibitors, anti-corrosion agents and antifreeze agents.

The test was expanded into two relationships:

1. It was used alongside that prescribed in ASTM D-1384-65 corrosive water synthetically produced water with 20 "German total hardness as well an urban tap water used.

2. Due to the increasing importance of aluminum alloys, in addition to the prescribed metals, three additional aluminum alloys were added in a second test: Metal “package” was tested, with steel spacers being used accordingly.

The comparative tests were made with anti-freeze agents with corrosion inhibitors according to the Britisl Standards 3150: 1959. 3151: 1959 and 3152: 1959 de British Standards Institution and Commercial Antifreeze.

To the superiority of the corrosion inhibitors and anti-corrosion agents according to the invention also for purely aqueous solutions, such as those used in heat transfer systems. For example, central heating ^ are used, the ASTM test was modified in two further tests so that a purely aqueous solution was used for the prescribed metal "package" by a special

309 545 / ^

9 ίο

Aluminum alloy used in radiator construction c) Municipal tap water with a continuous

was extended. sectional composition of

Examples 1 to 8 66mgCr / l.

In these examples, antifreeze agents of 5 116 mg SO ₄ 1,

the following composition is used: 10.3 'dKH,

94.05 percent by weight monoethylene glycol. ¹⁸ ' ^{3 <dNKH}

4.0 percent by weight sodium benzoate. _{S (J are at ielhafte cr} r _indunesge MAEBE corrosive

0.65% by weight of soda, _{iq sion-inhibiting} hot solutions that contain the

0.35 percent by weight borax, corrosion inhibitors according to the invention of the general

0.40 weight sprozen Na numni nt. _mejnen | « _{ Concentration of 0.07 Ge

Contains 0.30 percent by weight of sodium nitrate.

0.05 Gew.ch sprozen Natnumsihcat and the possibly expanded Melali "package"

0.20 percent by weight of a compound of general _{hJ, di (f fo} ^S, _{the metals or} metal alloys.:

my formula I ^fc ° °

according to the following list: 1. Copper SF-Cu

. ",. ,. 2. Soft solder with 33% Sn content

\ F ^h T _r 3. Messine Ms 63 halhhart

J lsochinohn _{M 4 Stah} , ^ _{37 ie dec iert}

I 4-bromoisoquinone ₅ gray cast iron GGL 15

!! \ 8-Nrtroch.no in _{6 Silum} ^ _{n GALSi6} Cu4

Example 5 2-chloroquinoline η

Example 6 3-methylisoquinoline g '

Example 7 4-amino quinaldine ₂ q

Example 8 5-Aminoisoquinoline "jq '^ LM" SiO 5

For testing according to ASTM designation:

D-1384-65 was a mixture of 1 part by volume each. Table 1 below shows the results

Antifreeze and 2 parts by volume of water following the test of these exemplary corrosion inhibitors

gender consistency used: 30 generating aqueous solutions and thus also the frost

. ... _._ ",. _ .... , Protective means specified in such a way that

a) Water with a total German hardness of 20, produced ⁶

makes from distilled water by adding

_ ",,, ^ ,,,,, in the column" Example "the first digit the two

CaCl, corresponding to 2. ^ dNKH .. referred to as playful antifreeze.

CaSO ₄ according to 2.5 dNKH, 35 _{the k} , _{ejne letter c the} water used and

MgCl ^ corresponding to 2.5 dNKH, _{depending on} number 1, the corresponding

^ ^g ^? V, ^enls P ^rec hend 2.5 dNKH. _{search with the annoyed} metal "package"

Ca (HCO ₃ ) ₂ according to /.5-dKH and designated

Mg (HCO ₃ ), corresponding to 2.5 ° dKH. _{and in the late >> Meta} i, _{e <(dic zilTern dic MeUllle}

b) Corrosive water according to ASTM D-1384-65. 'n ⁴ ° or metal alloys corresponding to the above 1000 g of distilled water are dissolved: denote the standing list.

148 mg Na ₂ SO ₄ .

165 mg NaCl. The numbers in the table indicate the determined

138 mg NaHCO ₃ . 45 weight losses converted into gm ² .

Table 1

example 1 2 1.2 Metal no. -0.9 0.9 6th 7th 0 0 Q No 1.0 1.6 0.5 L ⁴ I ⁵ -0.2 0.6 2.1 0.4 0 0.1 la 0.5 -1.4 0.6 1.4! 1.7 0.7 -0.2 0.9 -0.6 0 Ib 1.0 2.9 1.1 0.8 0 0.4 1.3 lc 2.0 0.8 0.1 1.2 1.1 -0.5 0.8 IaI 1.2 -0.5 0 1.2 -1.1 -0.4 0.7 IbI 2.4 2.3 2.9 0.6 0.4 0.5 0.3 -O2 0 lc 1 1.7 1.3 0.9 0.1 1.8 2.0 0.8 (U 2a 0.4 -0.7 1.2 0.7 1.5 0.1 -1.3 -1.1 2 B 1.2 0.8 1.6 -0.5 0.8 0.7 2c 0.6 0.4 0.8 0 -0.3 0 2al 0.3 0.5 0 0.4 0.2 0.1 2bl 1.7 0.9 2.3 -0.6 0 2cl 0.7 -0.2 1.3 3a

continuation

12th

example

3 b 3 c 3 a 1 3bl 3c 1 4a 4b 4c 4a 1 4b! 4c 1

7a 7b 7c 7a 1 7bl 7c 1

-0.3 2.6 Meta 4th 11 No. 5 I. 0.6 1.7 0.7 1.4 1.6 1.5 1.2 0.4 3.8 0.2 1.0 1.0 0.1 0.3 2 "* 0.6 1.2 -0.3 -0.2 0.3 2.4 1.3 -0.1 1.0 1.0 1.7 0.8 0.2 0.3 1.8 2.8 1.0 -0.5 0 0.7 2.9 1.9 0.5 -0.7 0.8 1.9 1.4 0 0.2 1.1 2.0 1.3 -0.2 0.3 1.8 2.2 1.0 0.3 0 2.6 1.6 2.4 0.4 -0.3 0.4 0.6 0.2 -0.3 8.3 2.0 3.1 2.1 -0.4 1.5 1.7 4.3 1.6 0.7 1.0 1.4 0.2 0.2 0.2 7.7 3.0 0.7 0.7 -0.2 0.5 1.6 1.1 1.1 0.4 0.4 1.4 0 0.1 -0.4 0.2 1.3 -0.4 0.5 -0.2 0.8 0.7 0.1 0.3 -0.4 1.8 1.8 0.4 1.0 -1.1 1.5 1.9 0.2 1.4 0.2 1.1 -0.2 0.9 1.2 -0.5 0.9 1.6 -0.4 1.7 0.4 0.8 1.6 1.4 -0.4 0.2 0.8 1.9 0.2 -1.0 0.3 1.0 1.7 ο 2.5 -0.3 0.4 0.8 -0.2 1.2 0.2

0.5 0.4

-0.3

0.2 0.4 0.5

3.3 -0.2 -0.5 -0.1 -0.7

1.3 -0.4 -0.1 -1.2 -0.8

-0.4 1.3 0.3 0 0.4

0.2

0.2

-0.4 -0.7 -1.6

-0.3 -0.7

-0.6 -1 ■>

-0.3 0.1

- 0.2

0.6

0.4

0.2

-0.6

-1.0 -1.1 -0.8

0.1-0.6

-0.3

-1.5

2.3

0.4

0.4

1.2

-0.6 -0.2 -0.4

-0.4 -0.3

-1.0 -0.5

-0.5 0 0.5

Examples 9 and

Example 9 corresponds to Example 1 with the difference that the antifreeze agent instead of 0.20 percent by weight Quinoline only contained 0.10 percent by weight quinoline.

Example 10 corresponds to Example 2 with the difference that the antifreeze contained only 0.10 percent by weight isoquinoline instead of 0.20 percent by weight isoquinoline.

The test results obtained are summarized in Table II below, with the Information in the table has the same meaning as the information in Table I.

I. 1.6 j Table II 4th 5 6th 7th 0 ^y example 1.0 0.8 1.2 Metal no. 1.7 1.7 0.4 No. 2.0 1.3 1.1 0.7 0.9 0.5 0.3 -0.2 0.8 1.7 0.4 2.9 1.2 0.4 1.8 9b 0.6 1.6 0.7 0.4 -0.3 0.3 0 9b 1 10b iObl

Comparative Examples A to C

For the comparative examples A to C were also three different solutions are used, each with the one in Examples 1 to 8 under a. b and c described water were used. Furthermore, the same metal "packages" were used as in Examples 1 to 8 described.

Example A.

Antifreeze solution with corrosion inhibitor according to British Standard 3152: 1959: 1 part by volume Ethylene glycol, containing 2.5 percent by weight borax, diluted with 2 parts by volume of water.

Example B.

Antifreeze solution with corrosion inhibitor according to British Standard 3150: 1959: 1 part by volume of glycol, Contains 3.5 percent by weight of triethanolamine phosphate and 0.25 percent by weight of mercaptobenzothiazole sodium, diluted with 2 parts by volume of water.

Example C

Antifreeze solution with corrosion inhibitor according to British Standard 3151: 1959: 1 part by volume glycol, containing 5.0 percent by weight sodium benzoate and 0.5 percent by weight sodium nitrite, diluted with 2 parts by volume of water.

The test results obtained are compiled in Table III below, the information in the table having the same meaning as the information in Table 1 .

Aa 1 2 3 Table 111 4th I ⁵ ... -. .
6.3 7th 2.0 I. B. -0.4 2.0 ei s pi e 1 III 99.0 example away 2.0 53.0 2.0 Metal no. 45.0 r "'
91.3 9.1 16.4! -0.8 1.9 125.3 No. Ac 1.0 86.6 0.6 3.5 165.7 10.5 2.7! -0.4 1.8 117.7 Aa 1 0.1 76.0 1.4 16.8 115.0 2.0 -0.3 AbI 0.4 58.5 3.0 7.4 77.0 1.4 0.6 -0.3 Ac 1 0.2 209.3 2.8 1.9 96.8 2.4 -0.7 -0.6 Ba 0.4 117.1 2.8 1.6 86.8 1.0 0.6 -oil 0.4 0 Port 1.4 0.3 1.4 1.4 21.0 10.5 2.4 0.5 4.4 Bc 1.6 0.5 2.3 6.4 15.9 8.6 0.2 0.7 1.2 Ba 1 0.6 -0.5 1.8 7.7 19.0 !,! BbI 1.5 -0.9 2.2 4.4 21.7 2.3 Bc 1 0.8 0 2.8 4.0 20.1 0.3 Approx 1.0 -0.4 1.1 10.5 45.0 1.3 0.8 Cb 3.0 -0.2 0.9 -0.3 -0.2 1.2 17.4 Cc 2.6 -0.2 o, s - 0.4 1.6 1.2 5.1 CaI 3.3 0.4 2.0 -0.2 0.6 CbI 0.6 0.6 0.3 -0.6 0 CcI 3.4 0.8 0.6 -1.2 -0.1 6.2 1.2 1.5 0.5 -0.2 Comparative experiments I to IV

For the comparative tests I to IV, four commercially available antifreeze agents from the winter of 1970 71 were used, the main components of which were determined by qualitative and, in some cases, quantitative analysis.

Example I.

Antifreeze.thahend4.1% Sodium Benzoate, 0.33% Sodium Nitrite, Borax, Sodium Silical.

Example II

Commercially available antifreeze, containing 2.2% sodium benzoate. 0.27% sodium nitrite. Borax, Sodium nitrate, sodium silicate. organic nitrogenous substance.

Commercial antifreeze, containing 2.4% sodium benzoate, 0.15% sodium nitrite, borax, ss nitrogenous organic matter.

Example IV

Commercially available antifreeze, containing 0.05% sodium nitrite, 3.5% borax, sodium silicate.

The comparative experiments were carried out in the same way as in Examples 1 to 10 and A to C. The results are listed in the table below, the designations having the same meaning as in Examples 1 to 10 and A to (

f> s have.

For the sake of a better comparison, the table furthermore two attempts each of Examples 1 and 2 have been included.

bitor ykol,> hosnzosser.

iitor koJ, and with

i die ben

Table IV

example
No. 1 2 3 Meta
4th HNr.
5 6th 7th 0 8th 9 Ib
IbI 0.5
1.2 -1.4
-0.5 0.5
0.1 0.8
0 -0.9
2.1 0.9
-0.4 0.8 0.1 0.7 2 B
2bl 0.4
0.3 -0.7
0.5 0.9
0.8 0.6
-0.5 1.1
1.8 0.1
0.2 2.3 -0.2 0.1 Ib
IbI 4.3
1.2 2.5
5.2 4.0
1.7 4.0
1.6 18.5
29.1 0.5
0.5 0.4 2.0 5.1 Man
II bl 1.5
1.2 0.5
0 3.0
1.7 3.0
0.6 25.0
9.9 i, 0
1.6 2.5 2.4 5.6 HIb
IIIbl 2.0
1.7 2.0
1.1 1.5
1.6 1.0
2.2 2.0
5.9 8.5
12.1 5.4 2.1 12.4 IVb
IV bl 5.1
2.6 2.8
4.9 3.9
2.7 3.5
0.6 3.0
2.1 4.0
4.0 4.6 8.9

Claims (9)

Patent claims: 1. Process for the preparation of corrosion-inhibiting Antifreeze agents based on glycols and their aqueous solutions, characterized in that per se known corrosion inhibitors containing antifreeze nitrogen heterocycles of the general formula / V V-Pi / V V_, (I) wherein X and Y stand for a nitrogen atom or the group C - R ⁴ , where X and Y do not simultaneously ^{mean a nitrogen atom or the group CR 4} , and R ¹ to R ^{4 are} identical or different and are hydrogen, an alkyl radical, a halogen atom , the nitro or amino 30th 35 wherein X and Y stand for a nitrogen atom or the group C - R ⁴ , where the radicals X and Y do not simultaneously ^{mean a nitrogen atom or the group C - R 4} , R ¹ to R ^{4 are} identical or different and are hydrogen, an alkyl radical , a halogen atom, the nitro or amino group, and π stands for the numbers 0, 1, 2 or 3, can be added. 2. The method according to claim 1, characterized in that as compounds of the general Formula 1 quinoline, 2-chloroquinoline, 8-nitroquinoline, 4-aminoquinoline, Isoquinoline. 3-methylisoquinoline, 4-bromoisoquinoline, or 5-aminoisoquinoline be used. 3. The method according to claims 1 and 2, characterized in that the compounds of general formula I the antifreeze in an amount of 0.04 to 1.0 percent by weight, based on the total amount. 4. Process according to Claims 1 to 3, characterized in that the compounds of the general Formula I based on the antifreeze in an amount of 0.06 to 0.5 percent by weight on the total amount. 5. Antifreeze based on glycols, in particular ethylene glycol, containing 0.04 up to 1.0 percent by weight nitrogen heterocycles according to the general formula R ¹ group, and π for the numbers 0, 1, 2 or 3 stands, and 1.0 to 10.0 percent by weight sodium benzoate, 0.2 to 3.0 percent by weight soda, 0.1 to 1.5 percent by weight borax, 0.1 to 1.0 percent by weight sodium nitrite, 0.1 to 1.0 percent by weight sodium nitrate and 0.02 to 1.0 percent by weight sodium silicate. 6. Antifreeze according to claim 5, containing 0.06 to 0.5 weight percent nitrogen heterocycles according to the general formula in which X and Y stand for a nitrogen atom or the group C - R ⁴ , where X and Y do not simultaneously mean a nitrogen atom or the group C - R ⁴ , and R ¹ to R ^{4 are} identical or different and are hydrogen, an alkyl radical, a halogen atom, the nitro or amino group, and / 1 stands for the numbers 0, 1, 2 or 3, and 2.0 to 7.5 percent by weight of sodium benzoate, up to 2.0 percent by weight soda, up to 1.0 percent by weight borax. up to 0.75 percent by weight sodium nitrite, up to 0.75 percent by weight sodium nitrate and 0.06 to 0.5 percent by weight sodium silicate. 7. Antifreeze according to Claims 5 and 6, containing 0.2 percent by weight nitrogen heterocycles according to the general formula (D in which X and Y stand for a nitrogen atom or the group C - R ⁴ , where X and Y do not simultaneously mean a nitrogen atom or the group C - R ⁴ , and R ¹ to R ^{4 are} identical or different and are hydrogen, an alkyl radical, a halogen atom, the nitro or amino group, and η stands for the numbers 0, 1, 2 or 3, and 4.00 weight percent sodium benzoate.
0.65 percent by weight soda,
0.35 percent by weight borax.
0.40 percent by weight sodium nitrite.
0.30 percent by weight sodium nitrate and
0.05 weight percent sodium silicate. 8. Corrosion protection agent for antifreeze based on glycols and their aqueous solutions, consisting of 0.2 to 2 parts by weight of a substance of the general formula I.
R ¹ / Y "C-R> in which X and Y stand for a nitrogen atom or the group C - R ⁴ , where X and Y do not simultaneously mean a nitrogen atom or the group C - R ⁴ , and R ¹ to R ^{4 are} identical or different and are hydrogen, an alkyl radical, eia halogen atom, the nitro or amino group, and η stands for the numbers 0, 1, 2 or 3, and 5 to 20 parts by weight of sodium benzoate,
1 to 6 parts by weight of soda,
0.5 to 3 parts by weight of borax.
0.5 to 2 parts by weight of sodium nitrite.
0.5 to 2 parts by weight of sodium nitrate and
0.05 to 2 parts by weight of sodium silicate. 9. Corrosion protection agent according to claim 8, consisting of 0.3 to 1 part by weight of nitrogen heterocycles the general formula