DE2035047B2 - STABILIZING PEROXIDIC COMPOUNDS - Google Patents

Description

R ¹

-CH ₇ -C-

COOA

(D

and

-CH,

■ C -

CHO

(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

30th

R R

COOA COOA

(III)

35

are constructed

where A stands for a hydrogen atom, a valence of a monovalent or polyvalent metal, especially an alkali metal, or ammonium, R and R ^{1 are} identical or different and mean an alkyl group with 1 to 6 carbon atoms, especially a methyl group, or a hydrogen atom and R ^{1 can} also denote a halogen atom, 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 carboxylate groups of at least 50% 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

b) Polyoxycarboxylic acids or -carboxylates, the

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

- CH ₇ -C-

CHjOH

(IV)

bb) mainly 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

and

CH ₂ OH
CH ₁ - C -

COOA

CH ₂ OH
CH, - C -

(VI)

CH ₇ OH

(ViI)

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, 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 Bleaching flults.

The invention relates to the stabilization of peroxidic compounds, in particular in peroxide-containing bleaching liquors, by adding chelate complexes of certain 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, since the bleaching effect is low in the acidic and neutral range. In addition, the alkali has the task of removing or removing the degraded colored accompanying substances in the fibers. Without stabilizers in the bleach bath, the rate of decomposition of the peroxidic active oxygen suppliers in the alkaline liquors is so high that only fiber damage, but no significant bleaching effect

is achieved. While in the bath bleaching, d. H. with a liquor ratio of over 1: 5, not only with water glass, the most famous bleach stabilizer, but can also achieve reasonably good results with organic stabilizers, show the latter in the case of impregnation bleach, d. H. at liquor ratios of 1: i to 1: 1.5, such as. B. with the J-Box, Conveyor belt, thermal dwell as well as high temperature and also cold bleaching, since higher chemical concentrations here are used, significantly poorer or unsatisfactory results. the best known such organic stabilizers are aminocarboxylic acids or their salts such as ethylenediaminetetraacetic acid, Nitrilotriacetic acid, dietary triamine pentaacetic acid, etc., all of which have in common is that it oxidizes very quickly to the corresponding amine oxides in peroxide-containing solutions and thus lose their stabilizer effectiveness.

The bleaching bath stabilization by Wa. ~ ^C er glass has the disadvantages that on the one hand particularly large amounts of stabilizer must be used relative to the bleaching agent and, moreover, precisely because of this, there is always some sodium silicate on the fiber to be bleached, or what is even worse, due to the action of the Water hardness precipitates the almost insoluble Mg-silicate, whereby the fiber suffers in its grip as well as in its printability (Textil-Praxis, 1968, p. 261 ff.). It is therefore already a decisive technical advance if the necessary amount of waterglass can be reduced significantly with approximately the same bleach bath effectiveness.

It is known that polymeric carboxylic acids which contain units with adjacent carboxyl groups, like maleic acid units, relatively water-soluble complexes with polyvalent metal ions increase able to form (cf. B. J. Fe 1 ber 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 are the Mg salts or Mg complexes of such polymeric carbonic acids suitable for stabilizing peroxidic bleaching baths (cf. Textil-Praxis, 1968, p. 261 ff.). Aside from that Advantage of the N-Freiheil and lower Oxydiei availability bring these compounds over the conventional perstabilizers, e.g. DTPA-Mg-Salz, but no significant advantages in the stabilization of alkaline, peroxide-containing liquors.

From numerous works in the field of polyelectrolytes it emerges, on the other hand, that in contrast to such polymeric carboxylic acids those which have more distant carboxyl groups carry, e.g. polyacrylic acids. with polyvalent melallions although they also form complexes, but these do preferably with the incorporation of the polyvalent metal ion as a "crosslinker", d. H. under stress from very distant or too different Carboxyl groups belonging to polymeric amino molecules are formed and are therefore practically insoluble. This different behavior has its reason. f> s that polymeric carboxylic acids with adjacent carboxyl groups, e.g. B. Maleic acid-styrene copolymers, which due to the known interaction of the carboxyl groups with each other an increase the first dissociation constant (corresponding to the inductive effect from the neighboring COOH Group), but a reduction in the second dissociation constant (corresponding to the inductive Experience the effect of the now neighboring COO ~ group, so that they lead to the formation of salts of the type:

COO-Me ⁺ ... ÖOC

so water-soluble ion pairs are energetically favored. In addition to the same statistical effects for both types, these effects are much less pronounced for carboxylic acids with carboxyl groups further apart in the molecule (cf. G. Kortiim "Lehrbuch der Elektrochemie", Verlag Chemie [1962], pp. 328 to 338). Furthermore , 7-rings would be formed 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 with adjacent carboxyl groups, while in an analogous complex formation on polymeric carboxylic acids with more distant COOH groups such . B. the polyacrylic acid, 8 or even larger rings would have to arise, whereby the formation of such water-soluble complexes is also entropically disadvantaged compared to the water-insoluble complexes crosslinked via the metal ions (cf. BJ F e 1 over loc. Cit. P. 2500 ). The chelating effect on such "middle" 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 described in the literature as practically insoluble compounds (cf. H. Staudinger and E. Urech, HeIv. Chim. Acta 12 [1929], 1127; P. D ο ty and G. E hr 1 i, Ann. Rev. phys. Chem. 2 [1952], 100; TI Rabek »Polyelectrolyte-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 , should be suitable for stabilizing alkaline, hydrogen peroxide-containing liquors, although as an essential precondition for one Such an effective wedge is assumed in the same laid-open specification to be water solubility or at least colloidal solubility of the Mg salt used. Due to the above statements now ₀ only the latter is true but even for such low concentrations such as 2 ° / ₀₀ or even only l% at best. Higher concentrations of such Mg salts therefore hardly lead to an improvement in effectiveness, but only to an increase in the size or number of the colloidal or simply suspended Mg polycarboxylate particles. The effectiveness of all previously known peroxide stabilizers on the basis of Mg salts or complex polymeric carboxylic acids with non-adjacent carboxyl groups are set by fixed limits, which, as the comparison test shows, also lie below what the currently best-known Mg salts N- containing complexing agents, / .. B. DTPA-Mg salt. This applies not only to the peroxide-stabilizing effects of these substances, but also

also for the risk of Mg polycarboxylate or Mg hydroxide precipitates being deposited in the Bleach liquor or on the bleached material.

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

a) Polyaldehydocarboxylic acids or polyaldehydocarboxylates, the

aa) from units of the general formulas and or

and

or

R ¹

- CH, - C -

COOA

-CH ₂ -C-CHO

(I)

(H)

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-

c -

COOA COOA

(UI)

are constructed

where A represents 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 represent an alkyl group having 1 to 6C atoms, in particular a methyl group or a hydrogen atom and R ^{1 can} also denote a halogen atom, 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% Carbonyl groups of at most 50% and terminal, wholly or partially lactonized hydroxyl groups of 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

b) Polyoxycarboxylic acids or Polyoxycarboxylalcr :. the

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

R '

-CH ₇ -C-

OH

or

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

and

CH ₂ OH CH ₂ -C-

COOA

CH ₂ OH CH ₂ -C-

CH ₂ OH

(VII)

CIl, C

C H, O H are built up,

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 even aqueous solutions with concentrations of 20% and even considerably more can be produced.

It is also surprising that the inventive Polyaldehydo- or Polvoxycarboxylate to be used only relatively low molecular weights must have or that just the substances whose mean molecular weights are below those lying for the polycarboxylic according to the German Offenlegungsschrift 1 804 504 can be described as optimal or even as minimally necessary, in the <> 5 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 salting in 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 the magnesium compounds known from German Offenlegungsschrift 1804 504 are significantly exceeded can be.

The polyaldehydocarboxylic acids to be used according to the invention can be used in a manner known per se by copolymerization of, / i-unsaturated aldehydes with «, / (- unsaturated carboxylic acids in the presence of radical catalysts or redox catalysts as well as partial oxidation of Polyaldehydes, such as polyacroleines, or through partial Cannizzaro reaction on polyacroleines or of polyaldehydocarboxylic acids.

However, it can be particularly favorably achieved by oxidative polymerization of (!, // - unsaturated aldehydes, preferably acrolein, or oxidative copolymerization of, - unsaturated aldehydes with 31,, - unsaturated carboxylic acids, preferably acrylic acid, or by oxidative terpolymerization of «, / ^ - unsaturated aldehydes with«, / ^ - unsaturated mono- and with «, / ^ - unsaturated dicarboxylic acids , the required maximum hydroxyl content and the required degree of polymerization are observed. Both oxidizing agents and polymerization initiators are peroxides or peracids. Preference is given _{to using H 2} O. The COOH and CO content of the polymers can be determined in the oxidative polymerization by the applied amount of e.g. acrolein, acrylic acid and oxidizing agent e in place. Since the peroxidic compound also acts as a regulator, its concentration or Specified amount relative to the monomer, the degree of polymerization and thus indirectly also the hydroxyl content can be influenced.

As the amount of oxidizing agent increases, the degree of polymerization 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 1: 1, an average degree of polymerization of 3.2, a COOH content of 67%, a C0 content of 14% and obtained a hydroxyl content of about 15%. If, on the other hand, under otherwise identical conditions, a ratio of H ₂ O ₂ to acrolein of 0.7: 1 is used, a degree of polymerization of 13, a COOH content of 66%, a CO content of 21% and an OH- Content of about 7%. The polymerization is expediently carried out as a solution polymerization. However, it can also be carried out as a precipitation polymerization or emulsion polymerization. The oligomers or polymers obtained by this method can, in addition to the

mentioned units in a minor amount also rope-attached vinyl groups in the form of units of the type

- C —CH-

I (viii)

CH = CH ₂

as well as roped 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, = CH

OH

O -

(IX)

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

CH ₃ - CH -
CHO

CH ₃ - CH -
COOH

(X)

(XI)

and residues of the catalyst used occur. You are door to the application according to the invention as well meaningless.

The percentages of the carboxyl or carboxy IaI, Carbonyl and hydroxyl values correspond to basic mole percentages, that is the mean 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 in completely or partially hydrated form or exist in the form of cyclic structures as a result of reactions with neighboring groups, so that cyclic, acetalic and acylalic structures arise:

- CH, -C -

OH

CH

OH

(Ha)

R CH ₂ R

I / \ L

CH ₂ -CC

HC

HO

CH

^/ O

(Hb)

R CH ₂ R

I / \ l

CH ₂ -CC

HC C

HO

(lic)

These have special structures. since they have easily revci-sible equilibria with the simple ones open carbonyl structures (II) are related, no special meaning for the invention Use.

The polyoxycarboxylic acids to be used according to the invention can optionally also be subordinate Have amounts of pendant vinyl ouei carbonyl groups, however, for effectiveness the perslabilizers are of no importance. In many cases, the above-described form polyaldehydocarboxylic acids an intermediate stage in the production of peroxycarboxylic acids. The polymers can e.g. B. in a conventional manner by copolymerization of acrolein, acrylic acid or substituted Acrylic acids in the presence of free radical catalysts or redox catalysts and subsequent Implementation according to Cannizzaro. 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 vinyl alcohol or their derivatives, such as acrylonitrile. Can continue they by oxidation of copolymers of acrolcine with allyl alcohol or its derivatives or with vinyl alcohol derivatives. Also one Copolymerization of allyl acetate or a cyclo copolymerization of allylacrylal with acrylic acids with simultaneous saponification and oxidation of polyacrolcin homo- or copolymers !! come 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 claan polymers, which also contain, in minor amounts, units of the general formulas

CH ₁ OH

- CH ₂ - C -

COOA

CH ₂ OH
CH ₂ -C-

CH ₂ OH

(VI)

(VI)

exhibit. In any case, however, the polymerization and reaction conditions, and in particular the amounts of the oxidizing agent, must be chosen so 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 maintained, i.e. a corresponding number must be maintained of units (I) or units (I) and (III) be present at the same time.
Peroxides are used as the oxidizing agent

, ο 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 bigger

If this ratio is, the greater the number of carboxyl groups and uiiigekelii Ί present in the polymer. Since the pei oxidic 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. If, on the other hand, all other things being equal, a ratio of H, O ₁ 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 monomers 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 degree of polymerization is determined by the acrylic acid content in the starting mixture 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, and also vinyl alcohol derivatives. Allyl alcohols and their derivatives, etc.

The homo- or copolymerization of the * acrolein * can, depending on the desired carboxy group content in the polymer, be carried out either as a solution or as a precipitation polymerization, preferably in an aqueous medium. When using peroxidic compounds as oxidizing agents, it is advisable to introduce them and, if appropriate, the comonomer or part thereof in aqueous solution or suspension and, if appropriate, to add the acrolein together with the remaining comonomer, advantageously at an elevated temperature of about 50 to 100 ° ^C. In the case of solution polymerization, the polymers obtained can optionally be used directly for further reaction after concentrating the solution. It is often advantageous here to destroy any amounts of oxidizing agent still present in the solution, for example by adding small amounts of MnO ₂ or activated carbon. However, it is also possible to precipitate the solution polymers from the reaction mixture with the aid of a dilute acid, for example hydrochloric acid. The residual monomers can -l B. be recovered by distillation directly from the Reaktioiiigemisch. In this case the distillation residue is a highly concentrated aqueous one

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 Filtral 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 polyaldehydocaibonic 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 in the formaldehyde elwa siöchiorrieirisclien amounts to 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 ^n. When reacted in solution, solutions of the salts of the peroxycarboxylic 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 can then be used directly for the purposes according to the invention. By precipitation from the reaction mixture, e.g. 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.

It is also possible to control the course of the Cannizzaro reaction in such a way that one is ultimately practical neutral salt solutions are obtained by adding lye in such a way that the excess lye increases as the temperature progresses The degree of implementation becomes less and less and finally just zero at the end of the reaction achieved.

The neutralization of the excess alkali should only take place with such acids, the salts of which do not interfere with the use of the polymers produced as persiabiiisaiuicii. v.; c dies for example when using CO, the case is particularly advantageous, however, the neutralization with the polyoxycarboxylic acids themselves in pure solid form or with solutions of the polyaldehydocarboxylic acids to undertake. This gives pure, neutral solutions of the salts of the polyoxycarboxylic acids from which they are made can be easily isolated by evaporating the water. The polyoxycarboxylic acids used for neutralization can, for example, be precipitation polymers obtained in the manner described above have been; the corresponding polyaldehydocarboxylic acids can, for example, be solution polymers such as those described above Way are easily accessible. You can choose from the reaction with the base, if appropriate in the presence solutions obtained from formaldehyde can easily be precipitated with dilute acids.

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.

When using acrolein, optionally together with acrylic acid as starting monomers, arrives one of the preferred polymers to be used, consisting predominantly of those specified above Units (I) and (IV) or (V) are constructed. They represent the main part of the predominantly C - C bonds represent the main chain and are partly used in the treatment of polyaldehydocarboxylic acid trained after a Cannizzaro reaction. With this treatment, however, can also intermolecular aldol condensations between the aldehyde groups in the polyaldehyde carboxylic acid u-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 perslabilizers 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, wherein 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 perstabilisers. The end groups present in the polymer are also of no importance. which develop depending on the reaction conditions and reactants. If acrolein and H ₂ O _{2 are} assumed, one end group is always an OH group. In all other cases it is COH-, CH ₂ OH-. and CH ₂ = CH groups or around hydrogen atoms and around residues of the catalyst used.

The chelate compounds to be used according to the invention as stabilizers for peroxidic compounds, in particular in peroxide-containing bleach liquors, should contain a maximum of 1 equivalent of alkaline earth metal ions per equivalent of polyaldehydocarboxylate or polyoxycarboxylate, depending on the hardness of the water used to prepare the liquor. Preferably, however, an excess of polyaldehydocarboxylic acid or carboxylate and / or of polyoxycarboxylic acid or carboxylate is used. The information in the examples is therefore given in the form of formal designations, such as B. (POC) ₂ Mg or (POC) ₃ MgNa, where POC should stand for one equivalent of polyoxycarboxylate; Of course, it is not necessary here to adhere to integer equivalent ratios.

Both the chelate complexes of the polyaldehydocarboxylic acids or carboxylates mentioned as those from the polyoxycarboxylic acids or carboxylates mentioned are also excellent for Stabilizing peroxidic compounds, especially in peroxide-containing bleaching liquors, e.g. ß. in the Wood and textile bleaching or in paper manufacture. However, the chelal compounds are preferred

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

The following examples demonstrate the effectiveness of polyoxycarboxylic acid salts according to the invention tested in bath bleach liquors and in impregnation bleach liquors, of which the impregnation bleach liquors 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 Basic bleaching fluff formulations used.

example 1

With an impregnation bleach bath containing 35.0 ml Γ ¹ H ₂ O ₂ 35%, 7% NaOH and 2.5 ^{% 1} 20% polyoxycarboxylic acid Mg salt solution

((POC) ₂ MgCa]),

were subjected to the bleaching treatment after a treatment time of 2 hours on a Svetma laboratory steamer at 85 ° C. Here, (POC) ₂ Mg is a polyoxycarboxylic acid Mg salt, produced by adding 1 molar part of MgSO ₄ -LOsUiIg to 2 molar parts of polyoxycarboxylic acid Na salt solution, so that a 32.8% solid, 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, analogous bleaching tests were carried out with an impregnation bleaching pad 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 / 1} (c) of a commercially available bleach bath stabilizer solution containing, among other things, a magnesium salt containing nitrogen-containing complexing agent instead of the polyoxycarboxylic acid salt solution, with a bleaching time of 2.0 hours 85 ° C, with water of 5 "German hardness and in the presence of a dispersing or wetting agent - that is, under optimal conditions. The choice of water of 5 ° German hardness for the. Experiment c was carried out because when using such complexing agents as bleach bath stabilizers, higher water hardness has proven to be beneficial to their stabilizer effectiveness.

The chromaticity points of the thus-bleached nettle fabric were determined by measuring the remission (Zeiss-Elrepho, filter no. 6, against MgO = 100%) and on the containing with 35 ml Γ 'water glass impregnating at 2,5stündiger bleaching time and 90 ⁰ C. Based on liquor temperature.

attempt

Whitepots des stabilizer bleached nesse injured (POC) ₂ mg 73.9 (POC) ₂ mg 79.9 + Water glass N complex 73.8 sculptor

Example 2

A bath bleaching flolte of the composition was obtained: 4 ml 1 'H ₂ O ₂ 35%, 0.6 g Γ ¹ NaOM and 2.0 ml 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; COOH: OH ratio = 2.4. The measured values obtained were the data obtained on a bath bleach liquor of the same composition, but without complexing agents under otherwise identical conditions,

opposite 11:

Bath life
at X5 C

(Hours)

0
1

2.25

Active oxygen Rcs content

without (POC) ₁ MgNa
<% l

100
0.4
0.0

Example 3

with (POC) ₁ MgNa
<%>

100
100
100

An impregnation bleaching liquor with the composition: 35 ml Γ ¹ H ₂ O ₂ 35% was obtained. 7 g I ¹ NaOH and 12.0 ml Γ 'each. 16.0 ml Γ ', or 24.0 ml 1'

.50 20% polyoxycarboxylic acid salt solution of the type (POC) ₃ MgNa prepared 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 in Determined as a function of the bath service life. (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 % corresponding to the formal composition (POC) 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: Mitilcier degree of polymerization P = 50, COOH: OH ratio = 8.6. The measured values obtained were those of impregnation bleach baths of the same composition, but with 12.5 ml ¹ or 25 ml ^1, about 40% strength

Solution of a commercially available bleach bath stabilizer (see Example 1) instead of the polyoxycarboxylic acid salt solution according to the invention, compared to measured data.

Bath- Active oxygen residual content 16ml r ¹ 24 m! r ' Perslabilizer solution 25 ml r ¹ was standing
time at Polyoxycarboxylic acid salt solution (%) (%) (%) 85 ° C 100 100 12 ml Γ ¹ 100 12ml r ¹ 97 99.5 (%) 89 (Hours.) (%) 97. 99 100 82 0 100 97 99 91 75 0.5 95 96.5 97.5 85 71 1.0 94 82 1.5 94 80 2.0 94

Comparative experiment

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

Bath life at 85 C Active oxygen residual content (Hours) r / o) O 100 0.5 68.6 59.1 1.5 52.4 2.0 47.4

The following comparative experiment shows the superiority of the Chelal-Troiz to be used according to the invention and the low concentration of polycarboxy complexes The complex was already flocculating in writing about the German Offienlegungs- 20 lat-Mg complex 1 804 504 known complexes from water half of the bath observation time to a waste-soluble one Polyacrylic acids: separable precipitate.

Claims (1)

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