DE2035047C3 - Stabilizing peroxidic compounds - Google Patents

Description

and

R ¹
-CH ₂ -C-

COOA

-CH ₂ -C-CHO

(D

(H)

or

bb) mainly from units of the general formulas (I) and (II) as main components and next to it a subordinate number of units of the general formula

- C-

R.
-C-

COOA COOA

(HD

35

are constructed

where A is a hydrogen atom. a valence of a monovalent or polyvalent metal, in particular an alkali metal, or ammonium, R and R ^{1 are} identical or different and are an alkyl group with 1 to 6 carbon atoms, in particular a methyl group, or a hydrogen atom and R ^{1 is} also a halogen atom mean, the units (I), (II) and (III) can be arranged in any order and the average frequency of these units having a molar content of carboxyl or carboxyl groups of at least 50%, of carbonyl groups of at most 50% and on terminal, completely or partially lactonized hydroxyl groups from 0.2 to 66%, in particular 1 to 20%, and the degree of polymerization is between 3 and 600, in particular between 3 and 300, and / or

- CH ₂ - C -
OH

or

bb) predominantly from units of the general formulas (I) and (IV) and / or (V) as Main components and besides a minor number of units of the general formula (III) and / or of units of general formulas

CH, OH

- CH, - C -

COOA

and

- CH, CH, OH - C- are. ί
CH, OH built up

(VI)

where A and R again have the meaning given, the units (I), (III), (IV), (V), (VI) and (VII) can be arranged in any order and with the average Frequency of these units, even in the absence of one or more of these units, is between 0.5 and 16, in particular between 1.1 and 16, the ratio of carboxyl or carboxylate groups to hydroxyl groups and corresponds to Degree of polymerization between 3 and 600, in particular between 3 and 300, with alkaline earth metal ions, especially magnesium ions, for stabilizing peroxidic compounds, especially those containing peroxide Bleach liquors.

b) polyoxycarboxylic acids or carboxylates, the

aa) from units of the general formulas (I) and

60

-CH ₇ -C-

CH, OH

(IV)

65 The invention relates to the stabilization of percxidischen compounds, particularly in peroxide bleaching liquors, by the addition of certain Chelatkomp'exen polyaldehydocarboxylic acids and / or polyoxycarboxylic acids with alkaline earth metal ions, preferably magnesium ions.

For textile bleaching, the activation of the peroxidic bleaching agent by alkali is of the greatest importance, because the bleaching effect is low in the acidic and neutral range. In addition, the alkali still has the task of removing or removing the degraded colored accompanying substances of the fibers. Without Stabilizers in the bleach bath is the rate of decomposition of the peroxidic active oxygen suppliers so high in the alkaline liquors that only fiber damage, but no significant bleaching effect

: is achieved. While in the bath bleaching, d. H. with: in a liquor ratio of over I: 5, not only with water glass, the most famous bleach stabilizer, The latter show that it is also possible to achieve reasonably good results with organic stabilizers in the case of impregnation bleach, d. H. be · Flotlen conditions from I: I to I: 1.5. such as B. with the J-Box, Conveyor belt. Thermal dwell as well as high temperature and cold bleaching, since higher chemical concentrations here are used, significantly poorer or unsatisfactory results. The most famous such organic stabilizers are aminocarboxylic acids or their salts such as ethylenediaminetetraacetic acid. Nitrilotriacetic acid. Dietary triamine pentaacetic acid, etc. which all have in common- i ^ is sam. that it oxidizes very rapidly to the corresponding amine oxides in peroxide-containing solutions and thus lose their stabilizer effectiveness.

The bleaching band stabilization by water glass in turn has the disadvantages that on the one hand particularly Large amounts of stabilizer must be used relative to the bleach and also straight therefore always a-silicate on the fiber to be bleached. or worse, by exposure the water hardness precipitates the almost insoluble Mg-silicate, whereby the fiber in its The grip and printability suffer greatly (Textil-Praxis, 1968, p. 261 ff.). It is therefore already a decisive technical advance, if the necessary one with approximately the same bath efficacy The amount of water glass can be reduced significantly.

It is known that polymeric carboxylic acids which contain units with adjacent Cr ~ 'ooxyl groups, like maleic acid units, relatively water-soluble complexes with polyvalent metal ions increase able to form (cf. B. J. FeIber et al, J. Phys. Chem. 72 [1968], 7, p. 2496 ff.). However, such are Polymers for reasons of polymerization kinetics to a practically reasonable extent only in the form of Copolymers can be produced (cf. D. Braun et al, Macromol. Chem. 224 [1969], pp. 249 to 262), so that the active groups account for a very high proportion by weight of inactive organic material. It is also known that they contain the Mg salts or Mg complexes of such polymeric carboxylic acids suitable for stabilizing peroxidic bleaching baths (cf. Textil-Praxis, 1968, p. 261 ff.). Besides that These compounds have the advantage of being N-free and less oxidizable than the conventional Perstabilisaloren, z. B. DTPA-Mg-Salt, but no significant stabilization benefits alkaline, peroxide-containing liquors.

From numerous works in the field of polyelectrolytes te shows that, in contrast to such polymeric carboxylic acids, those carry more distant carboxyl groups, e.g. B. polyacrylic acids, with polyvalent metal ions Although they also form complexes, these preferably with the incorporation of the polyvalent metal ion as a "crosslinker", i.e. under stress from very far apart or too different Carboxyl groups belonging to polymer molecules arise and are therefore practically insoluble. This different behavior is due to the fact that polymeric carboxylic acids with adjacent carboxyl groups, z. B. maleic acid-styrene copolymers. due to the known interaction of the carboxyl groups among themselves an increase in the first dissociation constant (corresponding to the inductive effect from the neighboring COOH group), but a decrease in the second Dissociation constant (corresponding to the inductive effect of the now neighboring COO "group) experienced so that they lead to the formation of salts of the type

COO-Me ^H

OOC

that is, water-soluble ion pairs are energetically favored. In addition to the door, these effects are both types same statistical effects for carboxylic acids with carboxyl groups further apart in the molecule much less pronounced (cf. G. Kort on "Textbook of Electrochemistry". Verlag Chemie [1962], pp. 328 to 338). Furthermore, in the complex or salt formation of polyvalent Metal ions with polymeric carboxylic acids in the case of the formation of non-crosslinked chelates with polycarboxylic acids 7-rings are formed with adjacent carboxyl groups, while in the case of an analogous complex formation of polymeric carboxylic acids with more distant COOH groups, such as. B. the polyacrylic acids, Rings of 8 or even larger would have to arise, whereby the formation of such water-soluble Complexes, also entropic compared to the water-insoluble complexes crosslinked via the metal ions is disadvantaged (see B. J. FeIber loc. eh., P. 2500). The chelation effect on such "medium" rings is known to be even more unfavorable than on rings of 7. The salts of polyvalent metal ions with polyacrylates and similar polymeric carboxylic acids with non-adjacent carboxyl groups are therefore in the literature as practically insoluble compounds (cf. H. Staudinger and E. Urech, Helv.Chim. Acta 12 [1929], 1127; P. D υ t y and G. Ehrlich, Ann. Rev. phys. Chem. 2 [1952], 100; T. I. Rabek "Polyelectrolytes-General Introduction; Akademie-Verlag, Berlin [1967], pp. 7 and 50).

Nevertheless, it has become known from German Offenlegungsschrift 1 804 504 that even the practically insoluble Mg salts of polyacrylates or analogous polycarboxylates, used in concentrations of up to 2% ₀ for stabilizing alkaline liquors containing hydrogen peroxide, should be suitable, although as an essential prerequisite for one Such effectiveness is assumed in the same published patent application as water solubility or at least colloidal solubility of the Mg salt used. On the basis of the explanations given above, even for such low concentrations as, for example, 2 _{% ou} or even only 1% _(I at best only the latter applies. Higher concentrations of such Mg salts therefore hardly lead to an improvement in effectiveness, but rather only to an increase in the size or number of colloidal or simply suspended Mg polycarboxylate particles. The effectiveness of all previously known peroxide stabilizers based on Mg salts or complexes of polymeric carboxylic acids with non-adjacent carboxyl groups are thus set fixed limits, As the comparative experiment shows, they are also below what the currently best-known Mg salts of N-containing complexing agents, e.g. DTPA-Mg salts, are capable of. This applies not only to the peroxide-stabilizing effect of these substances , but

also for the danger of the deposition of Mg polycarboxylate or Mg hydroxide precipitates in the Bleach liquor or on the bleached material.

It has now been found that peroxidic compounds in particular in peroxide-containing bleaching liquors, can be stabilized by adding chelate complexes out

a) Polyaldehydocarboxylic acids or polyaldehydocarboxylates, the

aa) from units of the general formulas

R ¹

-CH, -C-

and

or

COOA

- CH, - C -

CHO

(ID

bb) mainly from units of the general formulas (I) and (II) as main components and next to it a subordinate number of units of the general formula

- C-

COOA COOA

(HI)

are constructed

where A is a hydrogen atom, a valence of a monovalent or polyvalent metal, in particular an alkali metal, or ammonium, R and R ^{1 are} identical or different and are an alkyl group with 1 to 6 carbon atoms, in particular a methyl group or a hydrogen atom, and R ^{1 can} also mean a halogen atom, the units (I), (II) and (III) can be arranged in any order and where the average frequency of these units is a molar content of carboxylbzvv. Carboxylate groups of at least 50%, carbonyl groups of at most 50% and terminal, completely or partially lactonized hydroxyl groups of 0.2 to 66%, in particular 1 to 20%, and the degree of polymerization between 3 and 600, in particular between

3 and 300, is, and / or off
«

b) peroxycarboxylic acids or polyoxycarboxylates, the

aa) from units of the general formulas (I) and

and or

- CH ₁ - C -

OH

or

bb) predominantly from units of the general formulas (I) and (IV) and or (V) as main components and next to it a subordinate number of units of the general Formula (III) and / or by incorporating the general formulas

CH ₂ OH j

; 1

■ - CH ₁ -C "- [(V
COOA

and

CH ₁ OH

- CH ₁ - C -

CH ₁ OH

(VII)

- CH, - C-

CH ₂ OH

are constructed

where A and R again have the meaning given, the units (I), (III), (IV), (V), (VI) and (Vii) can be arranged in any order and with the average frequency of these units even in the absence of one or more of these units 0.5 and 16, in particular between 1.1 and 16, the ratio of carboxyl or carboxylate groups corresponds to hydroxyl groups and the degree of polymerization is between 3 and 600, in particular between 3 and 300,

with alkaline earth metal ions, especially magnesium ions.

The chelate complexes mentioned are surprising and in contrast to all previously known Facts, although they are also composed of polymeric carboxylates with predominantly non-adjacent carboxyl groups exist, very soluble in water, so that with it even aqueous solutions with concentralizations of 20% and even considerably more can be produced.

It is also surprising that the polyaldehyde or polyoxy carboxylates to be used according to the invention only have to have relatively low molecular weights or that the substances whose average molecular weights are below those for the polycarboxylates according to the German Offenlegungsschrift 1 804 504 can be described as optimal or even as minimally necessary, in the Use in the form of their alkaline earth metal salts or ' (IV) complexes give the best results, at least

but develop an effect comparable to the known polycarboxylates.

The use of the polyaldehyde or peroxycarboxylic acids mentioned has the advantage that the corresponding alkaline earth metal salts or complexes, in particular the magnesium salts or complexes, can be prepared and used in practically useful concentrated solutions, and that when used for peroxide stabilization there is no risk of precipitation of precipitates. The possibility of using the chelate complexes to be used according to the invention is accordingly practical unlimited, so that with these products not only the effectiveness of the previously best-known perstabilizers on the basis of magnesium complexes nitrogen-containing complexing agents, but also the from the German Offenlegungsschrift 1 804 504 is significantly surpass known magnesium compounds can be.

The polyaldehydocarboxylic acids to be used according to the invention can be used in a manner known per se by copolymerization of α, / ί-unsaturated aldehydes with ^ -unsaturated carboxylic acids in the presence of free radical catalysts or redox catalysts as well as partial oxidation of polyaldehydes such as polyacroleines. or by partial Cannizzaro reaction on polyacroleins or on polyaldehydocarboxylic acids.

However, they can be used particularly favorably by oxidative polymerization of α, / ί-unsaturated aldehydes, preferably acrolein, or oxidative copolymerization of α, ρ-unsaturated aldehydes with α, / 3-unsaturated carboxylic acids, preferably acrylic acid, or by oxidative terpolymerization of -unsaturated Prepare aldehydes with α, / ί-unsaturated mono- and with α, /? - unsaturated dicarboxylic acids. However, the polymerization conditions must be chosen in a manner known per se so that the required minimum carboxyl content, the required maximum carbonyl content, the required maximum hydroxyl content and the required degree of polymerization are observed. Peroxides or peracids can be used as the oxidizing agent and, at the same time, the polymerization initiator. H ₂ O ₂ is preferably used. The COOH and CO content of the polymers can be determined in the oxidative polymerization by the amount of z. B. set acrolein, acrylic acid and oxidizing agent t) a the peroxidic compound acts as a regulator at the same time, can be controlled by their concentration or. The amount specified relative to the monomer of the Pdymeruatiorugrad and thus indirectly also the hydroxyl content can be influenced.

As the amount of oxidizing agent increases, the degree of polymer rotation decreases and vice versa. For example, with an initial H ₂ O ₂ concentration of 20% and a ratio of H ₂ O ₂ to acrolein of J: I, an average degree of polymerization of 3.2, a COOH content of 67%, a CO content of 14% and obtained a hydroxyl content of about 15%. If, on the other hand, a quantitative ratio _{of 0.7: 1 between H 2} O ₂ and acrolein is used under all conditions being the same, a degree of polymerization of ti is obtained. a COOH content of 66%, a CO content of 21% and an OH content of about 7%. The polymerisation is expediently carried out as a ion polymerisation. The OMap or polymers according to this method can, in addition to the units mentioned, also contain a minor amount of pendant vinyl groups in the form of units of the type

- C —CH-

I (VIII)

CH = CH ₂

as well as pendant groups of the type O - CH ₂ - CH ₂ - COOA

0-CH ₂ -CH ₂ -CHO

contain. However, these are meaningless for the use according to the invention.

In addition to those mentioned, end groups which can also be used are carboxyl, carbonyl, CH ₂ OH and hemiacetal groups of the type

CH ₂ = CH

OH

O -

(IX)

as well as vinyl groups or hydrogen atoms, ζ. B. in the form of groups of the type

(X)

CH ₃ -CH- 1 CHO J.

CH ₃ -CH-COOH

and residues of the catalyst used occur. They are also suitable for use in accordance with the invention meaningless.

Pie percentages of the carboxyl or carboxylate ,. Carbonyl and hydroxyl values correspond Basic mole percentages, that is the average number of COOH, CO and OH groups per 100 monomer units in the polymer.

In the polymers, the units of type (II) can also be present in completely or partially hydrated form or as a result of reactions with the neighboring groups in the form of cyclic structures , so that cyclic, acetal and also acyclic structures are formed :

CH

OH

OH

R CH ₂ R

I / \ l /

CH ₂ -CC

(Ila)

HC

HO

CH \

(Hb)

R CH ₂ R

I / \ l

CK ₂ -CC

HC

HO

(lic)

In doing so, these have special structures, as they have easily reversible equilibria with the simple ones are related to open carbonyl structures (II), no special meaning for the use according to the invention.

The polyoxycarboxylic acids to be used according to the invention can optionally also be subordinate Have amounts of pendant vinyl or carbonyl groups, however, for effectiveness of the perstabilizers are of no importance. In many cases, the above-described form polyaldehydocarboxylic acids an intermediate stage in the production of polyoxycarboxylic acids. The polymers can e.g. B. in a known manner by copolymerization of acrolein, acrylic acid or substituted acrylic acids in the presence of free radical catalysts or redox catalysts and subsequent conversion according to Cannizzaro will. They are also accessible e.g. B. by copolymerization of optionally substituted acrylic acids with allyl alcohol, by saponification of copolymers the acrylic acid esters and esters of Vinyialki »- hols or their derivatives, such as acrylonitrile. They can also be obtained by oxidation of copolymers of acrolein with allyl alcohol or its derivatives or with vinyl alcohol derivatives. Also one C> copolymerization of allyl acrylate or a cyclo-copolymerization of allyl acrylate with acrylic acids with simultaneous saponification and oxidation come from polyacrolein homo- or copolymers Door their manufacture in question. In principle, all processes are suitable as polymerization methods, such as precipitation, bulk or solution polymerization.

However, they can preferably be used in a manner known per se by an oxidative polymerization of acrolein and subsequent treatment of the polymer with a strong base, in particular an alkali hydroxide according to Cannizzaro. The treatment with the strong base can also be used after a less preferred variant take place with simultaneous condensation with formaldehyde. You get daeit polymers, which are also in subordinate Quantities Units of the general formulas

CH ₂ OH
-CH ₂ -C-

COOA

CH ₂ OH

(VI)

(VII)

-CH ₂ -C-

CH ₂ OH

• stepwise. In every case, however, the polymerization and reaction conditions and in particular the amounts of the oxidizing agent so selected that the required ratio of carboxyl or carboxylate groups to the hydroxyl groups in the end product and the minimum degree of polymerization of 3 are observed, d. i.e., it must a corresponding number of units (I) or units (I) and (III) must be present at the same time.

Peroxides are used as the oxidizing agent

ίο or peracids in question. However, preference is given to using _{H 2} O _2. The ratio of the carboxyl groups to the carbonyl groups can be adjusted in the oxidative polymerization by the ratio of the amount of oxidizing agent to the amount of acrolein. The greater this ratio, the greater the number of carboxyl groups present in the polymer and vice versa. Since the peroxidic compounds also act as regulators, the degree of polymerization is also influenced by the amounts in which they are used. As the amount of oxidizing agent increases, the degree of polymerization decreases and vice versa. For example, with a ratio of H ₂ O ₂ to acrolein of 1: 1, an average degree of polymerization of 3.2 and a COOH / C = O ratio of 5: 1 are obtained. Will on the other hand

If, under the same conditions, a quantitative ratio of H ₂ O ₂ to acrolein of 0.7: 1 is used, these numbers change to 13 and 3.2: 1.

The oxidative polymerization of acrolein can also be carried out in the presence of other copolymerizable morainers can be carried out in practically any quantities. The use of acrylic acid as a comonomer is particularly advantageous because its presence reduces the carboxyl group content in the polymer can be influenced directly. In addition, the acrylic acid content in the starting mixture determines the degree of polymerization influenced in the sense that it increases with increasing acrylic acid content.

Examples of other copolymerizable monomers are: alkyl acrylic acids. Haloacrylic acids, unsaturated Polycarboxylic acids and their derivatives, such as esters and nitriles, also vinyl alcohol derivatives, AUyI alcohols and their derivatives, etc.

The homo- or copolymerization of acrolein can be carried out depending on the desired carboxy group content in the polymer both as a solution and as a precipitation polymerization, preferably in an aqueous medium. When using peroxidic compounds as O \ y-

It is advisable to use these and optionally the comonomer or a part thereof in aqueous solution or suspension, and to add the acrolein, optionally together with the remaining comonomer, advantageously at an elevated temperature of about 50 to 100 ^° C. In the case of a solution polymerization, the resulting polymers can, if appropriate, after concentration of the solution be used directly for further reaction. It is also possible, however, to precipitate the solution polymers from the reaction mixture with the aid of a dilute acid, for example hydrochloric acid. The residual monomers can ζ. Ε can be recovered directly from the reaction mixture by distillation. In this case, the distillation residue represents a highly concentrated aqueous

Solution of the polymer, which can be fed directly to the further reaction. But you can also carry out the distillation to dryness and obtain the pure polymer in solid form. In the Carrying out a precipitation polymerization, the polymers can easily be separated off by filtration will. The residual monomers are then present in the filtrate and can continue in this form immediately be used. The precipitation polymer can be passed through with water and, if appropriate, with air further cleaned.

The polyaldehydocarboxylic acids initially obtained in this way can be reacted further in an aqueous solution or suspension in a manner known per se with a strong base, if appropriate in the presence of formaldehyde. Here, a possible procedure that is used to formaldehyde in approximately stoichiometric amounts of the aldehyde groups present in the polymer and prolonged stirring with gradual addition of alkali at room temperature or at elevated temperatures up to about 100 C ^c. When reacted in solution, solutions of the salts of the polyoxycarboxylic acids are obtained in this way in addition to an excess of alkali. The resulting solutions of the salts of the polyoxycarboxylic acids can be evaporated to dryness. The salts obtained are then to be used directly for the purposes according to the invention. B. with methanol, the salts are obtained in a particularly pure form. However, it is also possible, before evaporation, to neutralize the solution with a dilute acid, for example hydrochloric acid, or to precipitate the free acids.

Likewise, it is possible to control the flow of Cannizzaro reaction so that finally practically neutral salt solutions obtained by the alkali addition is metered such that the excess of alkali with advancing degree of conversion becomes less and less and finally to ^p of the reaction walls just reached zero.

The neutralization of the excess alkali should expediently only take place with acids whose salts do not interfere with the use of the polymers produced as perstabilizers, as is the case, for example, when using CO ₂ . However, it is particularly advantageous to carry out the neutralization with the polyoxycarboxylic acids themselves in pure solid form or with solutions of the polyaldehydocarboxylic acids. This gives pure, neutral solutions of the salts of the polyoxycarboxylic acids, from which they can easily be isolated by evaporating the water. The polyoxycarboxylic acids used for the neutralization can be, for example, precipitation polymers which have been obtained in the manner described above; the corresponding polyaldehydocarboxylic acids can, for example, be solution polymers, such as are easily accessible in the manner described above. They can easily be precipitated with dilute acids from the solutions obtained after the reaction with the base, if appropriate in the presence of formaldehyde.

The polymers to be used according to the invention have predominantly C - C bonds in the main chain and can be straightforward as well as networked.

Bti use of acrolein, if necessary together with acrylic acid as starting monomers. one arrives at the preferred polymers to be used, which are predominantly composed of the units (I) and (IV) or (V) given above. she represent the main component of the main chain, which is mainly composed of C - C bonds and are partly used in the treatment of polyaldehydocarboxylic acid after a Cannizzaro reaction educated. In this treatment, however, intermolecular aldol condensations between the to the aldehyde groups in the polyaldehydocarboxylic acid in the α-position, active CH groups and carbonyl groups one or more adjacent chains occur. This results in networks. the mentioned units (I) and (IV) or (V) are for the use of these polymers as perstabilizers essential.

Is the implementation of the polyaldehydocarboxylic acids with a strong base according to Cannizzaro carried out in the presence of formaldehyde, the units (VI) and (VII) are formed, with the degree of crosslinking can be controlled by the amount of aldehyde used.

Although the production of these polymers in the first phase by radical polymerization of Acrolein, units of the formula can also be used in the main chains

O —CH-

CH = CH ₂

(VIII)

be present in subordinate numbers. In general, their amount does not exceed 25 mole percent.

However, they are of no importance with regard to the effect as perstabilizers. The end groups present in the polymer, which are formed as a function of the reaction conditions and reaction agents, are also of no importance. If acrolein and H ₂ O _{2 are} assumed, one end group is always an OH group. In all other cases it is a matter of COH, CH ₂ OH, and CH ₂ = CH groups or hydrogen atoms and in the remainder of the catalyst used.

According to the invention as stabilizers for peroxidic compounds, especially in peroxide-containing compounds Bleach liquors, to be used chelate complexes, depending on the hardness of the Preparation of the liquor used water maximum

so 1 equivalent of alkaline earth ions per equivalent of polyaldehydocarboxylate or contain polyoxycarboxylate. However, an excess of polyaldehydocarboxylic acid is preferred or carboxylate 1. J or used on polyoxycarboxylic acid or carboxylate. the

ss information in the examples is given in the form of formal designations, such as B. (POC) ₂ Mg or (POC) ₃ MgNa, where POC should stand for an equivalent of polyoxycarboxylate; Of course, it is not necessary here to adhere to integer equivalent ratios.

Both the chelate complexes from the aforementioned polyaldehydocarboxylic acids or carboxylates ah those from the polyoxycarboxylic acids or carboxylates mentioned are also excellent Stabilizing ptioxidic compounds, in particular special in peroxide-containing bleaching liquors, z. B. in de Wood and textile bleaching or in papermaking. However, the chelal coma are preferred

plexes from the peroxycarboxylic acids or carboxylates ¹ ! with alkaline earth metal ions, preferably magnesium ions, because they cannot be subject to any side reactions even under extreme conditions, especially in a strongly alkaline medium.

The following examples demonstrate the effectiveness of polyoxycarboxylic acid salts according to the invention tested in bath bleaching liquors and in impregnating bleaching liquors, the impregnating bleaching liquors of both is known to have a much higher content of bleaching agents, since the goods to be bleached are impregnated with them is, while in the case of bath bleaching, the bleaching agent concentration corresponds to the longer liquor ratio is less. The examples listed explain the stabilizing effect on active oxygen. In order to show the effect of the substances according to the invention as clearly as possible, only simple Bleaching fiot basic formulations used.

example 1

With an impregnation bleach bath containing 35.0 ml Γ ¹ H ₂ O ₂ 35%, 7.0 g 1 - 'NaOH and 2.5 ml 1 "' 20% polyoxycarboxylic acid Mg salt solution

((POQ ₂ MgCa]),

were subjected to the bleaching treatment with a treatment time of 2 hours on a Svetma laboratory steamer at 85 ° C. Here, (POC) ₂ Mg is a polyoxycarboxylic acid Mg salt, prepared by adding 1 molar part of MgSO ₄ solution to 2 molar parts of polyoxycarboxylic acid Na salt solution, so that a 32.8% solids, of which 20% corresponds to the formal composition (POC) ₂ Mg in addition to Na ₂ SO ₄ , containing solution arises, mean. The polyoxycarboxylic acid on which the salt used here is based is characterized by the following values: Average degree of polymerization P = 3.2; COOH: OH ratio = 2.2.

In addition, similar bleaching tests were carried out with an impregnation bleaching bottle which additionally contained 10.0 ml Γ ¹ water glass (38 ° Be) (b).

Likewise, for a further comparison with the current state of technology, analogous bleaching tests with impregnation ^{bleaching liquors containing 2.5 g of I "1} (c) of a commercially available bleach bath stabilizer solution containing, among other things, a magnesium salt containing nitrogen-containing complexing agents instead of the polyoxycarboxylic acid salt solution, with a bleaching time of 2.0 hours at 85 ° C., with water of 5 ° German hardness and in the presence of a dispersing or wetting agent - that is, under optimal conditions As bleach bath stabilizers, higher water hardness has proven to be beneficial for their stabilizer effectiveness

The stated white points of the bleached nettle fabric were determined by measuring the remission (Zeiss Elrepho, filter no. 6, against MgO = 100) and applied to the ^{impregnation liquor containing 35 ml of 1 l} Was -'- at 2.5 seconds and 90 minutes C based on liquor temperature.

attempt stabilizer White points of the
bleached nettle
tissue a
b
C. (POC) ₂ mg
(POC) ₂ mg
+ Water glass
N complex
sculptor 73.9
79.9
73.8

Example 2

A bath bleach liquor of the composition: 4 ml Γ ¹ H ₂ O ₂ 35%, 0.6 g I " ¹ NaOH and 2.0 ml 1" ¹ 18.4% polyoxycarboxylic acid salt solution of the type (POC) ₃ MgNa with water of 0 ° German hardness and the bath stability is determined by determining the residual active oxygen content (titration with 0.1 n-KMnO ₄ solution) at 85 ° C as a function of the bath life. (POC) ₃ MgNa here means a mixed polyoxycarboxylic acid-Mg-Na salt, prepared by adding 1 molar part of MgSO ₄ solution to 3 molar parts of polyoxycarboxylic acid-Na salt solution, so that a 29% solids, of which 18.4% corresponds the formal composition (POC) ₃ MgNa in addition to Na ₂ SO ₄ , containing solution is formed. The polyoxycarboxylic acid on which the salt is based is characterized by the following values: Average degree of polymerization P = 50; COOK: OH ratios - 2.4. The. The measured values obtained were compared with the data obtained on a bath bleach liquor of the same composition, but without complexing agents under otherwise identical conditions:

Bad Standzei.
at 85 ° C

(Hours)

0
1

2.25

Active oxygen residual content

without (POC) ₃ MgNa

100
0.4
0.0

Example 3

with (POO ₃ MgNa

100
100
100

An impregnation bleaching liquor was used: Composition: 35 ml Γ ¹ H ₂ O ₂ 35%, 7 g Γ ¹ NaOH and 12.0 ml Γ \ 16.0 ml Γ ', or 24.0 m! Γ ¹ 20% polyoxycarboxylic acid salt solution of the type (POQ ₃ MgNa made with water of 0 ° German hardness and the bath stability by determining the residual active oxygen content (titration with 0.1 n-KMnO ₄ solution) at 85 ° C as a function of from

ss the bath life is determined. (POC) ₃ MgNa here means a mixed polyoxycarboxylic acid-Mg-Na salt, prepared by adding 1 molar part of MgS0 ₄ solution to 3 molar parts of polyoxycarboxylic acid-Na salt solution, so that a 31.4% solid, thereof 20 % according to the formal composition (POQ ₃ MgNa in addition to Na ₂ SO ₄ , containing solution is formed. The polyoxycarboxylic acid on which the salt used here is based is characterized by the following values: Average poly-

degree of merization P = 50, COOH: OH ratio = 8.6. The measured values obtained were those of impregnation bleaching baths of the same composition, but with 12.5 ml ¹ and 25 ml ¹ about 40%

15th

Solution of a commercially available bleach bath stabilizer (see Example i) instead of the polyoxycarboxylic acid salt solution according to the invention, compared to measured data.

Bath life

(Hourly

12 ml I ■

100 95 94 94 94

t " ktivsauerslofT residue content

I6ml 1

I ⁰ ZuI

100 97 97 97 96.5

alz solution Perstabilizer solution 25ml I " ¹ 24ml I " ¹ ! 2ml I " ¹ 1%) 1%) 100 100 100 89 99.5 91 82 99 85 75 99 82 71 97.5 80

Attempt at reconciliation

Execution analogous to Example 3, but using a magnesium polymethacrylate salt that is as readily water-soluble as possible in a concentration of IgT ¹ (corresponding to 1%) in the bleaching agent as a peroxide stabilizer:

Bathroom stand line at 85 C.
(Hours)

0.5

1.0

1.5

2.0

Aktivsau, Jrstofr residual content

The following comparative experiment shows the superiority of the chelate complexes to be used according to the invention on the complexes of water-soluble compounds known from German Offenlegungsschrift 1 804 504 Polyacrylic acids:

100 68.6 59.1 52.4 47.4

Despite the low concentration of polycarboxylate Mg complex the complex flocculated to a filterable one within the bath observation time Precipitation.

Claims (1)

Claim: Use of chelate complexes a) Polyaldehydocarboxylic acids or carboxylates, the aa) from units of the general formulas and or