DE4113003A1 - PROTEIN AS A BIODEGRADABLE STABILIZER FOR THE OXYGEN COMPOSITIONS OF TEXTILE WASTE - Google Patents

Description

The invention relates to novel, biodegradable Stabilisa for textile bleach systems in the presence of heavy metal traces based on proteins and / or protein derived products.

As a bleaching agent for textile bleaching when washing are used in West almost exclusively sodium perborate, sodium percarbonate and Hydrogen peroxide used in addition to the surfactants and other active substances during the washing process for soil release and Gewebeauf brightening (see, for example, Jakobi Löhr, Detergents and Textile Washing, VCH. 1987).

To typical stains that hardly remove without bleach For example, red and blue anthocyanin dyes of the Curry and mustard fruit, turmeric dye, brown tannins Teas, humic acids of coffee, tea, cocoa and carotenoids from carrots and tomatoes.

The principal mode of action of the bleaching agents comprises the chemical Saturation of delocalized double bond systems of colored ver Pollution by hydroxylation and its subsequent oxidative Fragmentation to water-soluble products.

A high efficiency of bleaching sets as selective as possible oxidative attack on the double bonds of the colored Verschmut in advance, in order at the same time to be present in large excess textile fibers to protect against oxidative damage.

The chemical reaction mechanisms of effective bleaching and fiber damaging side reactions differ significantly. Here he Possibilities open in the mode of action of bleach controlling intervene.  

The above-mentioned bleaching agents are sodium perborate and sodium percarbonate hydrolyze in water to form hydrogen peroxide and thus show the same bleaching mechanism:

However, they differ significantly in their shelf life. The sodium perborate is in the crystalline state as defined Peroxodiborat ion before, and thus shows in admixture with a Detergent powder extremely good storage stability.

The percarbonate on the other hand crystallizes as true peroxohydrate and is already unstable to humidity and can not be with mix other detergent ingredients. It mainly takes place Application as bleaching salt and in multi-component detergents where it can be stored separately from the detergents.

The bleaching mechanism of hydrogen peroxide is ionic as well run radically. Optimal, however, while sparing the wash good alone the ionic one. Hydrogen peroxide undergoes in alkaline Medium a heterolytic cleavage into a Perhydroxylanion that the actual selective bleaching species represents:

H₂O₂⇆HOO ^- + H⁺

The formation of the perhydroxyl anion is highly dependent on the temperature pending. It lies only at temperatures above 70 ° C in for the bleaching sufficient concentration.  

Nowadays, lower washing temperatures of 30-60 ° C are used Lich. Therefore, the perborate must be "activated": you put the washing For example, tetraacetylethylenediamine (TAED), which reacts with the Reacted hydrogen peroxide in the wash liquor to peracetic acid, which bleaches as such even at lower wash temperatures acts.

The homolysis of the hydrogen peroxide leads to a radical mechanism bleaching, which is very uncontrolled and unspecific:

H₂O₂ → HO · + · OH

HO + H₂O₂ → HOO · + H₂O

In addition to the unsaturated bonds of the dirt particles are also the chemical bonds of the textile fiber attacked, resulting in heavy Tex tilschädigungen can lead to pitting. The homolysis of the Hydrogen peroxide is catalyzed by heavy metal ions. In the Wash liquor can do so due to the unavoidable heavy metal traces come that the homolysis becomes the main reaction and the bleaching effect is significantly weakened. By masking the heavy metal ions leaves suppress the homolysis largely.

DE-OS 7 03 604 describes a method for the stabilization of pervers compounds during textile washing by magnesium silicate. In the All detergents today therefore contain magnesium silicate. Its effect is not enough. Reinforced is the Stabili sierungsseffekt by combining with a strong complexing agent such as for example, ethylenediaminetetraacetate (EDTA) or phosphonates such as Example diethylene triamine pentamethylene phosphonate (DTPMP).

This is all the more surprising, as described in the patent DE-PS 26 57 043 just the reverse case, namely the activation of H ₂ O ₂ bleach by the addition of special iron-EDTA complexes be written. In addition, it has long been known that radical polymerization processes with the redox system

H₂O₂ + Fe ²⁺ → · OH + OH ^- + Fe ³⁺

(see F. Haber and P. White, Pr. roy Soc (A) 147, 233 (1939)

the polymerization is accelerated by addition of EDTA (DE 8 73 747). This effect is characteristic of the redox system Fe ²⁺ / Fe ³⁺ . In contrast, hydrogen peroxide solutions are stabilized in the presence of the EDTA or phosphonate complexes of Cu and Mn ions.

That the stabilizing effect described above is positively assessed by the addition of complexing agents in textile bleaching is due to the fact that especially the drinking water only keeps a very low Fe content. According to EC directives, the guideline value for drinking water [Ullmann-Enzyklopädie der technischen Chemie, Vol. 24, p. 187 (4th edition, 1983)] is 50 μg / l Fe but 0.1-3.0 mg / l Cu. The low Fe concentration has no significant influence on the hydrogen peroxide bleaching, on the other hand occurs at a Cu content of 0.1 ppm Cu already a significant H ₂ O ₂ decomposition. At a content of 0.6 ppm of Cu, the decomposition already occurs spontaneously, and the bleaching effect is lost. The manganese content is also max. 20 μg / l negligible in drinking water. The trailed with the detergent metal traces are the concentrations max. in the 10 ug / l Be rich increase, so that ultimately the copper is the relevant for the radical decomposition of hydrogen peroxide in the textile bleach size.

Bleach stabilizers are in the usual detergent frame formulations contained in amounts of 0.1-2%.

However, the known bleach stabilizers show unfavorable ecological profiles:
According to G. Jakobi and M. Schwuger, Chemiker-Zeitung 99, 182 (1975), the common complexing agent EDTA and the entire class of Phospho nate be classified as extremely low biodegradable.

Ch. Gousetis u. a. Surfactants Surf. Det. 27, 41 (1990) make isoserine acid as a new stabilizer for detergents and cleaners, the Only after a longer residence time in the sewage treatment plant does it adapt biologically should be degradable.

It was therefore the task of finding a biodegradable bleach stabilizer, which in addition to a good complexing agent against copper ions as iron complex has no activating effect on the H ₂ O ₂ bleach and causes the same good washing effects as conventional stabilizers Sta.

This task was achieved through the use of protein and / or protein products (hydrolyzates or derivatives) dissolved as bleach stabilizers.

The invention therefore bleach stabilizers, which there da characterized in that they are protein and / or protein derived products which are capable of copper complexes of the formula I.

to form, being
R, R ', R'',R''': residues of the amino acid building blocks
Prot .: Residual Peptikette
X: H at a terminal amino group; Prot. In a mid-sized amide group
mean.

Known natural products that complex copper ions are, for. Wine acid and amino acids. The complexes are colored deep blue in water soluble and resistant to alkali. Their stability is sufficient not to stop the radical decomposition of hydrogen peroxide in Prevent the presence of copper ions.

It was therefore surprisingly found that the egg white and / or protein follower products form such stable copper complexes that they are resistant to alkali while Stabili tion of H ₂ O ₂ solutions. Furthermore, it was found, surprisingly, that when washing a tea-soiled cotton fabric with a common detergent formulation by the addition of protein or protein follow-up products in the presence of copper and iron ions significantly better soil removal takes place without addition.

Protein / protein derivatives

The protein bodies to be used according to the invention can be used, for example play with the organic raw materials collagen, casein or keratin as well as from yeast residues, often as waste products in large quantities Obtain quantities, isolate enzymatically or by acid hydrolysis.

The proteins or protein derivatives used should be a medium Molecular weight of 500 to 100,000, preferably 500 to 5000, on point. A particularly preferred starting material is collagen hydroly Sate, including chemically modified Kollageneiweißhydrolysate of which in particular carboxylmethylated collagen protein hydrolysates are preferred.

In contrast to most known copper complex compounds, the are always colored deep blue, it is the protein complexes pink to red-violet colored substances, which characterize it Are that the copper exclusively of 4 nitrogen ligands surrounded with the copper intramolecular energetically favorable Forming 5-rings and allowing multiple copper ions to a peptide chain may be bound (see formula I).  

R, R ', R'',R''': residues of the amino acid building blocks
Prot .: Residual Peptikette
X: H at a terminal amino group; Prot. In a mid-sized amide group

This complex formation has long been known as biuret reaction known and is considered as proof of protein (P. Pfeifer, S. Saure - Journal of Practical Chemistry 157 (1941) 97/124, 107 and B.G. Malm Ström, T. Wänngärd - J. Molecular Biol. 2 (1960) 118/24).

Form all known complexing agents for textile bleaching Copper complexes with oxygen or mixed oxygen-nitrogen Ligands (eg, EDTA and DTPMP).

It turns out surprisingly that proteins as a stabilizer for Textile bleaching systems in the presence of copper and iron, which in Kon concentrations as expected for normal textile washing are, exist, are effective.

In contrast to EDTA, they show no presence in the presence of iron ions activating effect on the radical decomposition of hydrogen peroxide solutions.  

Compared to the usual bleach stabilizers (eg EDTA), the Proteins in addition to their biological origin and their degradability the further advantage that it oxidations to hydrogen peroxide are stable.

They are usually in concentrations of 0.1-5%, preferably 0.2-2%, in common detergents or in bleaching salts in Konzen concentrations of 0.2-10%, preferably 1-10% used.

The invention will be illustrated by the following examples.

In the examples, an enzymatically produced Protein-based collagen-based protein hydrolyzate:

analysis Bioburden: | <1000 / g Humidity: <5% Ash: Max. 1% pH: 6-7 av. Molar mass: about 1700 Amine number: 131 mg KOH / g Amide nitrogen: 14.1% Total nitrogen: 17.4%

Determination of active oxygen

The active oxygen given in the following examples became determined by the following method:

Hydrogen peroxide reacts in acidic solution as follows:

H₂O₂ + 2J ^- + 2H⁺ → J₂ + 2H₂O

The resulting iodine is treated against a set sodium thiosulphate Titration of the solution:

J₂ + 2Na₂S₂O₃ → 2NaJ + Na₂S₄O₆

Implementation of the provision

50 ml of the product solution to be determined are pipetted off and immediately in a solution of 50 ml of isopropanol, 25 ml of potassium iodide solution (33.2 g / l, saturated) and 10 ml of 10 wt .-% sulfuric acid. This solution is heated under reflux for 2 minutes, the condenser thoroughly rinsed with isopropanol and with 0.1 sodium thiosulfate solution against titrated colorless.

1 ml of 0.1 Na₂S₂O₃-Lsg 0.05 mmol of hydrogen peroxide.

example 1

Stabilization of sodium perborate solutions in the presence of copper ion at 60 ° C by addition of protein hydrolyzate (Prot.).

All solutions contain 1.540 g / l = 10 mmol / l sodium perborate.  

The copper ions and the protein hydrolyzate are completed in 1 liter submitted to salted water at 60 ° C. Only shortly before the measurement will the Added amount of sodium perborate as a powder.

Example 1 shows that in the presence of only 0.64 mg / l of copper ions Perborat solution is completely decomposed after 5 minutes, while adding 0.3 g of protein hydrolyzate to the copper solution a full stabilization is achieved: after 3 hours still 97.9% of the active oxygen present.

The decrease of the active oxygen in the solution becomes dependent determined by the time:

Example 2

Stabilization of sodium perborate solutions in the presence of copper at 60 ° C by the addition of carboxymethylated protein hydrolyzate (CMProt.):

The protein hydrolyzate (prot.) Is dissolved in water (86 g / 350 ml) at 45 ° C solved. Within about 10 hours are simultaneously under one  Maintenance of pH to 8-9 molten chloroacetic acid (39 g) and Add 50% sodium hydroxide solution (66 g) slowly. The reaction solution is then evaporated to dryness.

Yield: 142 g
Sodium chloride content: 14%

Carboxymethylated protein hydrolyzate shows approximately the same Stabilizing effect on copper-containing perborate solutions such as in Example 1 mentioned protein hydrolyzate.

This product is tested analogously to Example 1:

Example 3

Stabilization of sodium perborate solutions in the presence of copper ions at 60 ° C. by addition of disodium tartrate (C ₄ H ₄ Na ₂ O ₆ , molecular weight: 194) or sodium glutamate (C ₅ H ₈ NNaO ₄ , molecular weight: 169)

Tatrat disodium tetrate (see Comparative Example 3C)
Glut of sodium glutamate (see comparative example 3D)

The sodium salt of tartaric acid is not suitable for stabilizing copper-containing Perboratlösungen suitable. The salt of glutamic acid shows a clearer when using higher concentration, though in relation to the protein a comparatively worse stability sierungseffekt.

The test is carried out analogously to Example 1:

Example 4 Decomposition behavior of sodium perborate solutions in the presence of Iron (III) ions at 60 ° C with the addition of protein hydrolyzate (Prot.)

The test is carried out analogously to Example 1. Instead of copper ions Submitted iron ions.

The reference substance used is ethylenediaminetetraacetate (EDTA).

Iron ions are low in concentrations of 0.6 ppm on the stability of perborate solutions. The addition of protein  shows no impairment. In contrast, by addition of EDTA which accelerates the decomposition of iron-containing perborate solutions means a worse effect.

Example 5

Oxidative stability of protein hydrolyzate (Prot.) To sodium perborate solutions with exclusion of heavy metals.

The test is carried out as described in Example 1.

The reference substance used is ethylenediaminetetraacetate (EDTA).

Protein is not oxidatively attacked by perborate solutions. EDTA on the other hand, it is oxidized by perborate.  

Temperature: 90 ° C

Example 6

With this example, the stabilization of the bleach in one conventional detergent formulation in the presence of copper and Iron ions by addition of protein hydrolyzate (Prot.) Or carboxymethy liertem protein hydrolyzate shown.

Practical experiment

Linitest - Laboratory Washing Mines (Heraerus)
Cotton test fabric with tea soiling (WFK-Testgewebe GmbH)

test water
19.2 ° dH (hardness synthetically adjusted with calcium and magnesium ions)
50 μg / l iron ions (EC guidelines for drinking water)
5 mg / l copper ions

Test detergent formulation (WMP powder)
7.2% alkyl benzene sulphonate
3.9% fatty alcohol oxethylate
2.7% soap
24.2% zeolite
3.9% cobuilder
19.0% sodium perborate tetrahydrate
2.5% tetraacetylethylenediamine (TAED)
9.6% soda
4.8% sodium metasilicate
1.0% carboxymethylcellulose
19.3% sodium sulfate decahydrate
1.9% complexing agent (bleach stabilizer)

Wash liquor: 7.5 g / l
Washing temperature: 60 ° C

The test fabric is incubated for 30 minutes at 60 ° C in 250 ml wash liquor washed, then rinsed and dried. The whitening will spectrophotometrically (Datacolor 3890) at = 560 nm over the Remission (R) determined.

Remission of the unwashed test fabric: R₀ = 48.8%

Washing results:

Claims (7)

1. bleach stabilizers, characterized in that they contain protein and / or protein derived products which are capable of copper complexes of the formula I. to form, being
R, R ', R'',R''': residues of the amino acid building blocks
Prot .: Residual Peptikette
X: H at a terminal amino group; Prot. In a mid-sized amide group
mean. 2. bleach stabilizers according to claim 1, characterized, that the protein and / or protein products follow a medium Have molecular weight of 500 to 100,000. 3. bleach stabilizers according to claims 1 and 2, characterized, that the collagen-based protein and / or protein product is used.   4. bleach stabilizer according to claim 3, characterized, that as a protein follow-up product a chemically modified Collagen protein hydrolyzate is used. 5. bleach stabilizer according to claim 4, characterized, that as collagen protein hydrolyzate a carboxymethylated Collagen protein hydrolyzate is used. 6. Use of the bleach stabilizers according to claims 1 to 5, characterized, that they are in common detergents containing bleach, or be used in bleaching salts. 7. Use of the bleach stabilizers according to claim 6, characterized, that the use concentration of 0.1 to 5% in conventional Detergents containing bleach are or 0.2-10% in bleaching salts.