DE1620902C - Process for the production of rubber-like epoxy polymers - Google Patents

Description

-C = C-C-

As chelating agents which are suitable for the production of the metal chelate compounds to be used in the process according to the invention, the following should be mentioned in particular: Esters of / S-keto acids, β - diketones, ο - hydroxyphenylcarbonyl compounds, amides of β-keto acids, hydroxyquinones and the zinc, Copper and aluminum salts of kojic acid. Esters of jS-keto acids are z. Methyl acetoacetate, butyl acetoacetate, amyl alpha acetobutyrate and propyl benzoylacetoacetate; / S-diketones are e.g. 2,4-pentanedione, 3-methyl-2,4-pentanedione, 3,5-heptanedione and benzoylacetone; o-Hydroxyphenylcarbonyl compounds are, for. B. salicylaldehyde, o-hydroxyacetophenone, ρ - butoxy - 0 - hydroxypropiophenone and ethyl o-hydroxybenzoate; Amides of / 3-keto acids are e.g. B. acetoaceto-p-anilide, acetoacetoacetamide; Hydroxyquinones are e.g. B. chloranilic acid, hydroxynaphthoquinone and hydroxyanthraquinone.

Typical examples of chelate compounds of metals in groups I to III of the periodic table are z. B. acetoacetate-copper, acetylacetone-calcium, Acetylacetone-Magnesium, Acetylacetone-Barium, Acetylacetone-Zinc, Acetylacetone-Cadmium, Acetylacetone-Copper, Acetylacetone-Aluminum, Acetylacetone-Potassium, Acetylacetone-Sodium, Acetylacetone-Lithium, Acetylacetone Beryllium, Salicylaldehyde Copper, 5-oxynaphthoquinone copper, alizarin aluminum

nium, alizarin calcium, alizarin copper, barium chloranilate and calcium chloranilate.

Examples of the structure of these metal chelate compounds are given below. It is believed, that the other metal chelate compounds also have similar structures.

Al

O = C

O-C

CH

CH,

Acetylacetone aluminum

Cu

O = C

O-C

OC ₂ H ₅ )

CH

CH ₃ j

Acetoacetic ester copper

Bis (5-hydroxy-naphthoquinone) copper

Tris (1,2-dihydroxyanthraquinone) aluminum

O = CH

Cu

HC = O ° "\ /

Bis (salicylaldehyde) copper

Barium chloranilate The preparation of these metal chelate compounds can be easily carried out by the usual procedures. For example, acetylacetone-copper can be easily obtained by adding a hot saturated aqueous solution of acetylacetone to an aqueous solution of copper acetate.
The proportions in which the organoaluminum compound, the chelate compound of a metal from groups I to III of the periodic table and water are used can vary over a relatively wide range. The molar ratio * of the chelate compound to the organoaluminum compound is within the range from 0.1 to 20, preferably from 0.5 to 5. The molar ratio of water to the organoaluminum compound can be within the range from 0.2 to 1.0, preferably from 0, 33 to 1.0, can be varied.

These three or two components react with each other and thereby form the in accordance with the invention Process used catalyst system which is new and shows very high activity. The catalytic The activity of the catalyst system differs somewhat depending on the respective sequence, with which the above components are mixed, but in all cases becomes independent of the sequence in which the components are mixed produces a catalyst system which can be used for the process according to the invention receive. If water is used as a component then it is preferred Mixing sequence: metal chelate compound - organoaluminum compound - water. the The amount of the catalyst to be used in the polymerization is in an amount ranging from 0.001 to 10 mol percent, based on the monomer, are used.

As epoxy group-containing monomers which can be polymerized by the process according to the invention, there should be mentioned: alkylene oxides, such as ethylene oxide, propylene oxide, 1-butene oxide, 2-butene oxide, isobutylene oxide and 1-hexene oxide; Cyclohexene oxide; Styrene oxide; Glycidyl ethers of phenol and bis-phenol; halogen-containing epoxy monomers, such as vinyl chloride epoxide, epichlorohydrin, β- methyl epichlorohydrin, epibromohydrin, epifluorohydrin, trifluoromethyl ethylene oxide, perfluoropropylene oxide and perfluoroethylene oxide, and epoxy monomers which contain olefinically unsaturated bonds, glycidyl, glycidyl methyl acrylate, and 2-methyl acrylate, glycidyl-methyl-5-acrylate, glycidyl-methyl-5-monoxide, glycidyl-methyl-5-monoxide, glycidyl-butyl methoxide, 6-butyl methoxide -epoxyhexene-1.

The monomeric epoxide to be used in the process of the invention is not limited to one of these monomers is limited, but there can be two or more monomers at the same time be used.

The unsaturated epoxy monomers can be mixed with the above-mentioned saturated epoxy monomers are copolymerized, vulcanizable polymers with olefinically unsaturated bonds can be obtained.

When carrying out the polymerization using the catalyst system according to the invention the use of a solvent or diluent is not absolutely necessary. However, either of the two can optionally be used if there is no harmful influence the catalyst system and on the monomer or monomers which are polymerized should. For example, inert hydrocarbons such as aliphatic, aromatic, cycloaliphatic or olefinically unsaturated hydrocarbons can be used.

The polymerization process of the invention can be carried out under a wide range of pressures and temperatures. The polymerization temperature is within the range from -50 to 200 ^° C., while the polymerization pressure is within the range from 1 to 200 at.

Both the preparation of the catalyst system and the polymerization can be batchwise or be carried out continuously. If desired, it is also possible to carry out the polymerization continuously with stirring in the phase of the reaction mixture having a predetermined composition owns to perform.

The polymer produced by the process of the invention is a rubbery material known as Starting material for the production of Gummibzw. Rubber products is suitable.

example 1

A well-dried, pressure-resistant glass polymerisation container with a capacity of 200 ml was filled with dry nitrogen. It was then dried over calcium hydride with 25 ml Benzene, 0.081 g (0.00025 mole) acetylacetone aluminum, 0.062 g (0.0005 mol) of triethylaluminum, 8.3 g of propylene oxide dried with calcium hydride and 0.0045 g (0.00025 moles) of water are charged in the order given. The reaction mixture was then polymerized at 70 ° C. for 3 hours with stirring.

After the polymerization was interrupted by adding acetone to the reaction mixture benzene was added to lower the solvent viscosity. Then became the polymerization catalyst removed by repeated washing with 1N hydrochloric acid. The reaction mixture was then neutralized with an aqueous sodium bicarbonate solution and washed with water, whereupon the Pressure was reduced to evaporate the solvent. It became an elastomeric solid polymer obtained with a yield of 32.3%.

The inherent viscosity of this polymer, measured as a benzene solution of 30 ⁰ C, was 15.7. (Unless otherwise specified, the inherent viscosities listed below were all measured under the conditions described above.)

Examples 2 to 5

If the sequence of addition of the catalyst in Example 1 according to the information in Table I was changed, high molecular weight solid polymers were nevertheless obtained.

Table I.

example Order of addition
(from left to right) PO yield
% Inherent
viscosity 2 Benzene, water, PO 20.5 14.3 IP), I *), PO *) 1.11 3 Benzene, I, water, II, 33.0 10.8 4th Benzene, I, II, water, 18.1 14.0 5 Benzene, PO, water, 13.1 4.4 *) ι = Acetylacetone aluminum. II = Triethylaluminum. PO = Propylene oxide

Examples 6-15

If Example 1 was repeated, with the difference that the molar amount of triethylaluminum used Was kept constant and the amounts of water and acetylacetone-aluminum used were changed according to the information in Table II, were nevertheless in all cases solid polymers obtained.

Table II

example • 6th Acetylacetone
aluminum (Molar ratio) water Molar ratio yield Inherent
viscosity 7th Triethylaluminum Triethylaluminum % 8th 0.1 0.0 3.2 0.8 9 0.1 0.1 34.1 10.4 .10 0.4 0.4 32.5 8.5 11th 0.4 0.7 37.0 , 11.2 12th 0.7 0.7 35.5 10.7 13th 1.0 0.7 30.8 9.3 14th 1.5 0.7 36.6 10.5 15th 2.0 0.0 4.3 4.4 2.0 0.4 26.7 7.8 2.0 0.7 30.6 10.3

Examples 16 and 17

Solid polymers were also obtained when the triethylaluminum in Example 1 was replaced by others Organoaluminum compounds were replaced as shown in Table III.

Table III example

Organoaluminum compound

Diethyl aluminum chloride ethyl aluminum dichloride tri-n-hexyl aluminum

Yield%

21.0 3.0

25.4

Inherent viscosity

4.8 1.2

Examples 19 to 29

Solid polymers were also obtained when the acetylacetone-aluminum in Example 1 was replaced by others Metal chelate compounds as indicated in Table IV.

Table IV

at
game Metal chelate compound water Out
prey
% Inherent
viscosity 19th Acetylacetone zinc without 1.9 2.4

at
game Metal chelate compound water Out
prey
% Inherent
viscosity 20th
21
22nd Acetylacetone
magnesium
Acetylacetone barium
Acetylacetone Calcium without
without
without 13.1
1.2
6.8 2.4
0.55
2.5 23
24
25th
26th
27
28
29 Acetylacetone zinc
Acetylacetone
magnesium
Acetylacetone barium
Acetylacetone Calcium
Acetylacetone lithium
Acetylacetone Sodium
Acetylacetone Potassium With
With
With
With
With
With
With 13.6
15.5
1.0
4.8
7.4
1.3
1.1 1.7
4.3
0.60
5.6
1.5
0.56
0.82

Examples 30 to 35

Example 1 was repeated, with the difference that the type of metal chelate compound changed, however, the amount used was kept constant; in the case of the organoaluminum compound the type and amount used were varied. In this case too, solid polymers were obtained, as shown in Table V.

Table V

example Alkyl aluminum (I) Metal chelate compound (II) Molar ratio
of (I) / (II) / H ₂ O yield
% Inherent
viscosity 30th Diethyl aluminum chloride Acetylacetone Magnesium 2/1/0 3.8 2.8 31 the same the same 2/1/1 2.8 1.5 32 the same Acetylacetone zinc 2/1/0 2.6 1.2 33 the same the same 2/1/1 4.2 1.6 34 Ethyl aluminum Acetylacetone aluminum dichloride 4/1/0 4.0 1.3 35 the same the same 4/1 / 0.5 4.4 8.6

Example 36

When Example 1 was repeated using η-hexane in place of benzene, a solid polymer with an inherent viscosity of 3.94 was obtained in a yield of 11.0%.

Examples 37 and 38

Solid polymers were also obtained if the polymerization temperature was exceeded during the process of the experiment of Example 1 was modified as shown in Table VI.

50

table VI Inherent
viscosity example Polymerization
temperature.
⁰ C yield
% 2.3
1.9 37
38 35
5 10.6
4.1

Examples 39 to 44

A well-dried, pressure-resistant glass polymerisation container with a capacity of 200 ml was filled with dry nitrogen, followed by 50 ml of benzene dried over calcium hydride was charged.

For this purpose, 0.020 g of the metal chelate compounds given in Table VII and 0.171 g of triethylaluminum were added in the order given.

The mixture was then reacted for 2 hours at 6O ⁰ C and then cooled to 25 ° C, after which 0.0135 g of water were added. Immediately then 11.6 g of dried propylene oxide were introduced, and polymerization reaction was carried out with stirring of the container for 5 hours at 6O ⁰ C. In this case, too, the solid polymers shown in Table VII were obtained.

209 528/566

Table VII

example Metal chelate compound yield
% Inherent
viscosity 39 Barium chloranilate 23.1 3.2 '40 Zinc salt of kojic acid 15.7 2.9 41 Aluminum salt of 19.4 2.7 Kojic acid 42 Acetylacetoacetic ester 11.0 1.2 copper 43 Bis- (5-hydroxynaphtho- 17.0 6.7 quinone-1,4) copper 44 Tris (1,2-dihydroxyanthra- 21.0 5.9 quinone) aluminum

IO

Example 45

Example 1 was repeated with the difference that butene-1-oxide was used instead of propylene oxide would. It became a solid polymer with a polymerization time of 1.5 hours inherent viscosity of 8.7 obtained with a yield of 25.7%.

Example 46

When a mixture of 5 g propylene oxide and 5 g butene-1 oxide was used in Example 1, was used at a polymerization time of 1.5 hours a solid polymer with an inherent viscosity of 3.8 obtained with a yield of 26.2%.

The specific viscosity of this polymer measured with a solution of 50 ⁰ C, which was prepared by dissolving 0.0473 g of the polymer in 50 ml of cyclohexanone obtained was 0.24.

(Unless otherwise noted, the specific viscosities given below were used all measured under the conditions described above.)

Example 49

Example 48 was repeated, with the difference that instead of triethylaluminum (0.21 g) triisobutylaluminum has been used. In this case, too, a solid polymer with a specific Obtained viscosity of 0.21 with a yield of 40%.

Examples 50 to 53

A well-dried pressure-tight glass polymerization vessel of 200 ml capacity was charged with 0.020 g of the metal chelate compounds shown in Table VIII, then filled with dry nitrogen, whereupon 50 ml of dry benzene and 0.171 g of triethylaluminum were added. After a 2-hour reaction the mixture at 6O ⁰ C, it was cooled to 20 ° C, after which 0.0135 g of water were added. 5 minutes later, 11 g of dried epichlorohydrin was placed in the container and polymerized at 60 ° C. for 5 hours. In this case too, solid polymers as shown in Table VIII were obtained.

B e i s ρ i e 1 47

A well-dried, pressure-resistant glass polymerisation container with a capacity of 200 ml was filled with dry nitrogen, whereupon 50 ml of dried n-hexane, 0.034 g of acetylacetone-aluminum, 0.018 g of water, 0.114 g of triethylaluminum and 19.1 g of vinylcyclohexene monoxide at intervals of 10 minutes in the given sequence. By polymerizing for 24 hours of the mixture at 70 ° C. also in this case became a polymer with an inherent viscosity of 0.55 obtained in an amount of 0.45 g.

Example 48

A well-dried, pressure-resistant glass polymerisation container with a capacity of 200 ml was filled with dry nitrogen, whereupon 0.0357 g acetylacetone-aluminum, 0.016 g of water, 0.126 g of triethylaluminum and 11.0 g of epichlorohydrin in the specified Sequence were introduced. Polymerization was then carried out at 60 ° C. for 3 hours with stirring. After the polymerization was interrupted by adding acetone to the reaction mixture Benzene added to reduce solvent viscosity. This was followed by the polymerization catalyst removed by repeated washing with 1N hydrochloric acid. The reaction mixture was then neutralized with an aqueous sodium bicarbonate solution and washed with water, whereupon the Pressure was reduced to evaporate the solvent. It became a solid polymer in one yield received by 63%.

Table VIII yield Specific
viscosity example Metal chelate compound 16.9 0.19 50 · Barium chloranilate 17.1 0.17 51 Zinc salt of kojic acid 17.8 0.15 52 Copper salt of kojic acid 18.9 0.23 53 Aluminum salt of Kojic acid Example 54

When Example 48 was repeated with the difference that the amount of acetylacetone-aluminum used Was 0.179 g and that no water was used, it also became a solid polymer obtained with a specific viscosity of 0.22 in a yield of 7%.

B e i s ρ i e 1 e 55 to 60

Example 40 was repeated with the following changes: 25 ml of benzene, 0.0144 g (0.0008 moles) of water and 0.114 g (0.001 moles) of triethylaluminum were used while the was being used Amount of acetylacetone-aluminum was changed according to the information in Table IX. If those Mixtures were polymerized for 5 hours at 70 ° C, solid polymers were also obtained as this shown in Table IX.

1 620 902 12th 11th Table XI Table IX

example Acetylacetone
aluminum yield Specific
\ τ ' 1' * "*. Triethylaluminum viscosity (Molar ratio) % 55 0.1 48 0.15 56 0.3 51 0.30 57 0.5 46 0.21 58 0.8 40 0.15 59 1.0 33 0.18 60 1.3 29 0.17

Table X

example Metal chelate compound yield
% 61
62 Acetylacetone copper
Salicylaldehyde copper 17th
9

, Example Amount of introduced
Monomers (g) - Propylene yield Epichlorohydrin
in the polymer oxide (Weight Epichlor 8.30 percent) hydrin 6.64 (%) 64 2.36 4.98 13.4 12.9 ίο 65 4.72 3.32 9.0 20.0 66 7.08 1.66 8.3 31.4 67 7.44 6.1 43.5 68 11.8 5.2 58.1

Examples 61 and 62

Solid polymers were also obtained when, in Example 48, the polymerization reaction was carried out using 0.009 g of water and 0.171 g of triethylaluminum and either acetylacetone-copper (0.0322 g) or salicylaldehyde-copper (0.0344 g) in place of acetylacetone-aluminum 5 hours at 6O ⁰ C was carried out. Most of these solid polymers were ^{insoluble in cyclohexanone even at 100 °} C. and therefore their viscosities could not be measured. The polymers obtained were found to have a highly crystalline structure by means of X-ray diffraction. Examples 69 to 71

If propylene oxide according to Example 1 with the epoxy-containing monomers indicated in Table XII, which contain olefinically unsaturated bonds, were copolymerized in all Cases obtained solid polymers. The infrared absorption spectra of these polymers showed the presence olefinically unsaturated bonds.

Table XII Example 63

A well-dried pressure-tight glass polymerization vessel with a capacity of 500 ml was filled with nitrogen, whereupon 180 ml of benzene dried with calcium hydride, 0.57 g of acetylacetone-aluminum, 0.030 g of water and 0.40 g of triethylaluminum were introduced in the order given. Then, after adding 22 g of dry epichlorohydrin and 22 g of dry ethylene oxide, the polymerization reaction was carried out for 24 hours at 40 ^° C., whereupon a solid polymer was obtained with a yield of 15.5%. This polymer was a copolymer containing 9.3 mol% of epichlorohydrin, which was determined from the value obtained by chlorine analysis.

B e i s ρ i e 1 e 64 to 68

A well-dried, pressure-tight glass polymerization vessel with a capacity of 200 ml was filled with dry nitrogen, whereupon 50 ml of benzene dried over calcium hydride, 0.032 g of aluminum acetylacetonate, 0.009 g of water and 0.114 g of triethylaluminum were introduced in the order given. Dry epichlorohydrin and dry propylene oxide were then added in the ratio given in Table XI, followed by polymerization at 60 ° C. for ^{1 hour and 20 minutes.} As shown in Table XI, solid polymers were also obtained in this case.

example Unsaturated epoxy monomer yield
% Inherent
viscosity 69
70
71 Allyl glycidyl ether
Glycidyl methacrylate
Vinyl cyclohexene monoxide 9.4
10.9
21.3 4.1
4.7
3.6

Example 72

A well-dried pressure-resistant glass polymerization vessel with a capacity of 3 liters, equipped with a stirrer, was filled with dry nitrogen, whereupon 21 dry benzene, 4 ml of a benzene solution containing 2.8 g of acetylacetone-aluminum, 0.64 g of water, 40 ml of a benzene solution containing 8.7 g of isobutylaluminum, and 460 g of epichlorohydrin were introduced in the order given. Then 5 hours at 6O ⁰ C was polymerized. After the polymerization reaction was stopped by adding acetone to the reaction mixture, the solvent and unreacted monomer were distilled off by blowing steam into the reaction mixture to separate the polymer. A polymer with a specific viscosity of 0.21 with a yield of 41.7% was obtained by vacuum drying.

100 parts of this polymer, 1 part of zinc stearate, 50 parts of carbon black, 5 parts of lead oxide, 2 parts of nickel dibutyldithiocarbamate and 1.5 parts of 2-mercaptoimidazoline were mixed on a roller and vulcanized by heating at 155 ° C. for 45 minutes to give a product was, which was a very excellent oil-resistant rubber with the following properties: tensile strength 120 kg / cm ^2, elongation 250%, rebound resilience 22.0% increase in volume after 7 hours of immersion in isooctane at 8O ⁰ C 4%.

Example 73

A well-dried stainless steel polymerization vessel with a capacity of 25 1, which was equipped with a stirrer, was

filled with dry nitrogen, followed by 19.2 kg of dry benzene and 2.62 kg of dry propylene oxide and 131 g of dry allyl glycidyl ether was charged, whereupon. 2.89 g of water were also added became. A catalyst mixture was then added to this mixed solution, which was formed by 10 minutes reaction of 160 ml of a benzene solution containing 26.2 g of triethylaluminum and 40 ml of a benzene solution containing 7.56 g of acetylacetone-aluminum was obtained at 25 ° C. Polymerization was then carried out at 60 ° C. for 5 hours. After the polymerization reaction by adding of 100 ml of acetone, which contained 10 g of phenyl- / S-naphthylamine as an antioxidant, to the reaction mixture was interrupted, it became the solvent and unreacted monomer

distilled off by blowing steam into the mixture to separate the polymer. By vacuum drying obtained 570 g of a rubbery polymer with an inherent viscosity of 7.6 receive. This polymer was shown to be entirely amorphous by X-ray diffraction.

The product obtained by mixing 100 parts of this polymer with 10 parts of zinc oxide, 5 parts of sulfur, 1 part of stearic acid, 55 parts of carbon black, 2 parts of tetramethylthiuram disulfide, 2 parts of mercaptobenzothiazole and 2 parts of phenyl - /? - naphthylamide and vulcanizing for 30 minutes Heating to 160 ^° C. had a tear strength of 142 kg / cm ² , a 300% module of 81 kg / cm ² , an elongation of 620%, a hardness (Shore A) of 78, and a tear strength of 78 kg / cm ² .

Claims (1)

Claim: Process for the production of rubber-like epoxy polymers, characterized in that that one at a temperature of - 50 to 200 ° C and at a pressure of 1 to 200 at at least one monomeric epoxide having an epoxy group in the molecule in the presence of one Catalyst system in an amount of 0.001 to 10 mol percent, based on monomeric epoxide, polymerized, which is composed of (1) an organoaluminum compound of the formula AlX _n R ₃ -. wherein η is a number from 0 to 2, X is a halogen atom and R is an alkyl, alkenyl, cycloalkyl or aralkyl group, and (2) a chelate compound in an amount of 0.1 to 20 moles per mole of an organoaluminum compound consisting of a Metal of groups I to III of the periodic table and a compound which contains at least one carbonyl and / or hydroxyl group in the molecule and optionally (3) water in an amount of 0.2 to 1.0 mol per mol of organoaluminum compound. 30th The object of the invention is to produce a very peculiar and valuable rubber-like substance by homopolymerization or copolymerization of monomers which have an epoxy group, such as. B. Propylene oxide or epichlorohydrin. The catalyst system to be used in the process of the invention comprises either (1) a system consisting of an organoaluminum compound and a chelate compound of a metal group I to III of the periodic table, or (2) a system consisting of an organoaluminum compound, a chelate compound of a metal from Group I to III of the periodic table and water consists. The invention relates to a process for the production of rubber-like epoxy polymers which is characterized in that one at a temperature of -50 to 200 ° C and at a pressure from 1 to 200 at at least one monomeric epoxide having an epoxy group in the molecule in the presence a catalyst system, in an amount of 0.001 to 10 mol percent, based on monomeric epoxide, polymerized, which is composed of (1) an organoaluminum compound of the formula AlX _n R ₃ - ,, wherein η is a number from 0 to 2, X is a halogen atom and R is an alkyl, alkenyl, cycloalkyl or aralkyl group, and (2) a chelate compound in an amount of 0.1 to 20 moles per mole of an organoaluminum compound consisting of a Metal - of groups I to III of the periodic table and a compound which contains at least one carbonyl and / or hydroxyl group in the molecule and optionally (3) water in an amount of 0.2 to 1.0 mol per mol of organoaluminum compound . The organoaluminum compound which is a component of the polymerization catalyst system of Invention represents is a compound of the formula ; AlX _n R ₃ _ " wherein _: n is a number from 0 to 2, X is halogen and R is; Denotes alkyl, alkenyl, cycloalkyl or aralkyl group. Examples of these organoaluminum compounds are: triethylaluminum, triisobutylaluminum, trihexylaluminum, dimethylaluminum fluoride, dimethylaluminum chloride, dimethylaluminum bromide, diisopropylaluminum chloride, isobutylaluminum dichloride, the isobutylaluminum dichloride, which is obtained by a direct reaction of an alkylaluminum halide with an alkylaluminum sesquichloride mixture with an alkylaluminum metal halide mixture, which is obtained by a direct reaction of an alkylaluminum halide with an alkylaluminum halide with an alkylaluminum halide mixture, which is obtained by reacting an alkylaluminum halide with an alkylaluminum halide, which is obtained by a direct reaction of an alkylaluminum halide with an alkylaluminum halide, or a mixture of an alkylaluminum halide, which is obtained by reacting an alkylaluminum halide, etc. Alkyl aluminum and an aluminum halide. The metal chelate compound used as the other component in the process of the invention of the polymerization catalyst system to be used is a chelate compound of a metal from group I to III of the periodic table, such as B. "Lithium, sodium, potassium, magnesium, calcium, Zinc, copper or aluminum. The chelating agents used to make the chelating compound Can be used are those that have either carbonyl or hydroxyl groups in their molecule or contain both. For example, the hydroxyenol compounds, which are on the carbon atom have a hydroxyl group in the ß-position to the carbonyl group, or phenol compounds suitable. This type of unsaturated organic hydroxycarbonyl compound is characterized by the following Structure marked. OH