WO1992009675A1

WO1992009675A1 - Stabilisation of percarbonate

Info

Publication number: WO1992009675A1
Application number: PCT/EP1991/002203
Authority: WO
Inventors: Heinz-Manfred Wilsberg; Rolf Puchta
Original assignee: Henkel Kommanditgesellschaft Auf Aktien
Priority date: 1990-12-01
Filing date: 1991-11-22
Publication date: 1992-06-11
Also published as: EP0559679A1; DE4038391A1

Abstract

By the use of compounds separating acetic acid in hydrolysis conditions, preferably from the group of N- or O-acetylised substances, it is possible to stabilise powdered percarbonate very effectively against the loss of active oxygen, especially in bleaching, washing, cleaning and disinfecting agents.

Description

"Stabilization of percarbonate"

The invention relates to the use of compounds which split off acetic acid under hydrolysis conditions to stabilize percarbonates and to the use of such compounds as stabilizers for percarbonates in bleaching, washing or cleaning agents.

Detergents and cleaning agents which contain a combination of an inorganic peroxide or perhydrate as a bleaching system and a bleach activator which forms an organic peracid under washing conditions have been known for a long time. The most frequently used bleaching components containing active oxygen are the alkali perborates, percarbonates, persulfates and persilicates, among which sodium perborate, which is used as tetra- or monohydrate, occupies a dominant position. Since the release of active oxygen from the per-compound, which is only to take place under the aqueous washing conditions, can also take place during the production and in particular the storage of such agents, as a result of which the availability of the per-compound for the actual intended use decreases, stabilizers have long been used searched for the bleaching systems mentioned. The stabilizing effect of ethylenedia intetramethylene-phosphonic acid is known from German Offenlegungsschrift DT 22 14500. The coating of the oxidizing agent with copolymers containing polyvinyl chloride has been proposed in German Offenlegungsschriften DT 2402 392 and DT 2402393. Peroxo compounds stabilized by a coating of crystallized sodium carbonate in combination with other mineral salts are known from the German patent application DT 2417572. The stabilizing effect of phosphate coatings is known from European patent application EP 24201. German patent DE 25 31 466 proposes the use of certain rare earth complexes as stabilizers for percarbonates. The stabilizing effect is due to the German patent specification DE 2655971 and the European patent specification EP 30 759 the coating of per compounds with fatty acids is known. Bleaching agents which contain certain α-hydroxyacrylate polymers as stabilizers for per compounds are known from German laid-open specification DE 3337719 and European patent specification EP 021498.

The difficulty of incorporating peroxidic bleaching components stably into detergents or cleaning agents is evident from the large number of proposed stabilization options. For percarbonate-containing bleaching systems, the problem of inadequate storage stability is particularly difficult to solve, since this perhydrate is extremely susceptible to hydrolysis and is rapidly decomposed by normal atmospheric humidity, as well as in bleaches containing water, which are stored in water-impermeable packaging. decays with loss of active oxygen.

Surprisingly, a new way has now been found to stabilize percarbonate.

The invention relates to the use of compounds which split off acetic acid under hydrolysis conditions for the stabilization of powdery percarbonate, in particular the use of the compounds which split off acetic acid under hydrolysis conditions as stabilizers for powdered percarbonate in solid bleaching, washing, cleaning and disinfecting agents.

The compounds which split off acetic acid under hydrolysis conditions are preferably selected from the group of the N- or O-acyl compounds and their mixtures. These include, in particular, multiply acetylated alkylamines, acetylated glycolurils, N-acetylated hydantoins, hydrazides, triazines, triazoles, urazoles, diketopiperazines, sulfurylamides, cyanurates and acetylated sugar derivatives. The use of N, N, N ', N'-tetraacetylethylenediamine, 1,5-diacetyl-2,4-dioxo-hexahydro-1,5,5-triazine, tetraacetylglycoluril, pentaacetylglucose and mixtures thereof is particularly preferred. This group of compounds are well known cold bleach activators for peroxo compounds. These compounds had previously been assumed to have a precisely destabilizing effect in the presence of customary peroxo compounds and when water was ingress. It is all the more surprising to find that these substances known as activators are actually in combination with percarbo- act as stabilizers. The stabilizing compounds can be in the form of powders, but also in the form of granules. Such granules preferably consist of at least 90% by weight, in particular over 92% by weight, of the compound which splits off acetic acid under hydrolysis conditions, the remainder consisting of 100% by weight of granulation auxiliaries and water and inorganic salts. Among the granulated stabilizers, tetraacetylethylenediamine (TAED) with average grain sizes of 0.01 mm to 0.8 mm, such as can be produced, for example, by the process described in European Patent EP 037026, is special with the aid of carboxymethyl cellulose prefers.

The percarbonate stabilizers are preferably used in amounts such that the molar ratio of stabilizer to percarbonate is 1:50 to 1: 2, in particular 1:10 to 1: 2. Since these compounds act as bleach activators, that is to say react in the presence of water with peroxo compounds to form peracetic acid and thus give rise to a highly effective oxidizing agent in aqueous washing or cleaning solutions, it is all the more surprising that such substances in the Are able to stabilize percarbonate very effectively.

The percarbonate to be stabilized is preferably an alkali percarbonate, in particular sodium percarbonate. Such percarbonates can be prepared by known processes, for example by adding aqueous hydrogen peroxide to the corresponding carbonate in accordance with German laid-open documents DE 2805338 or DE 2925 732, or by crystallization from an aqueous solution containing hydrogen peroxide in accordance with the German designations DE 2303627 or DE 2364634 ¬ and optionally granulated with the aid of conventional granulation aids. The percarbonate is preferably used in the form of powders with average particle sizes of 0.1 mm to 0.8 mm and bulk densities of 750 g / 1 to 1100 g / 1, in particular 850 g / 1 to 1000 g / 1.

As a result of the use according to the invention, powdery percarbonate can be stabilized very effectively. A particular advantage of the invention, however, is that the stabilizing effect of the compounds to be used according to the invention also comes into play when the percarbonate is part of a bleaching, washing or cleaning agent is present. In this case, agents of this type can have all the constituents usually contained in them, which include, in particular, surfactants, builder substances, inorganic filler salts, enzymes, complexing agents for heavy metals, perfumes and dyes.

The bleaching, washing, cleaning or disinfecting agents preferably contain 5% by weight to 90% by weight, in particular 15% by weight to 80% by weight, of percarbonate stabilized according to the invention, the molar ratio of stabilizer to percarbonate being preferred 1:50 to 1: 2, in particular 1:10 to 1: 2.

The builder substances suitable for these agents are water-soluble or water-insoluble compounds or mixtures of two or more such compounds. Suitable builder substances are, in particular, those from the class of the polycarboxylic acids, in particular polymeric acrylic acids, methacrylic acids, maleic acids and copolymers of these, sheet silicates, in particular bentonites, aluminum silicates, in particular zeolites, alkali metal silicates, in particular sodium silicate and alkali metal carbonates, in particular sodium carbonate. The aforementioned polycarboxylic acids are usually used in the form of their alkali metal salts, in particular their sodium or potassium salts. The preferably incorporated zeolites are in particular those of the NaA or NaX type or mixtures thereof. Such builder substances are preferably present in amounts from 20% by weight to 90% by weight, in particular from 40% by weight to 80% by weight.

The detergent is preferably present in the compositions in amounts of from 2% by weight to 40% by weight, in particular from 5% by weight to 20% by weight. These are preferably anionic or nonionic surfactants or mixtures thereof.

Suitable anionic surfactants are in particular those of the sulfate or sulfonate type, but other types such as soaps, long-chain N-acyl sarcosinates, salts of fatty acid cyanamides or salts of ether carboxylic acids, such as are obtainable from long-chain alkyl polyglycol ethers and chloroacetic acid, can also be used. The anionic surfactants are preferably used in the form of the alkali or ammonium salts, in particular the natural salts. Particularly suitable surfactants of the sulfate type are the sulfuric acid monoesters of long-chain primary alcohols, natural and of synthetic origin with 10 to 20 carbon atoms and those of secondary alcohols of this chain length. In addition, the sulfuric acid monoesters of the aliphatic primary or secondary alcohols ethoxylated with 1 to 6 moles of ethylene oxide come into consideration. The sulfonate-type surfactants are primarily the alkylbenzenesulfonates with Cg to Cis alkyl groups and the esters of oc-sulfofatty acids. Other surfactants that can be used are the alkanesulfonates which are obtainable from C12- to Ci8-alkanes or from corresponding olefins, and also the olefinsulfonates, as are obtained, for example, from long-chain monoolefins with an end or internal double bond by sulfonation with gaseous sulfur receives trioxide. The nonionic surfactants in question include alkyl polyglycosides with 10 to 22 carbon atoms in the alkyl part and the alkoxylates, in particular the ethoxylates and / or propoxylates of linear or branched chain alcohols with 10 to 22 carbon atoms, preferably 12 to 18 C atoms. The degree of alkoxylation of the alcohols is generally between 1 and 20, preferably between 3 and 10. In addition, corresponding ethoxylation and / or propoxylation products of alkylamines, vicinal diols and carboxamides, which correspond to the alcohols mentioned with regard to the alkyl part, and also from Alkylphenols with 5 to 12 carbon atoms in the alkyl radical can be used.

Alkylbenzenesulfonates with linear Cg to C15 alkyl groups, fatty alcohol sulfates with 12 to 18 carbon atoms and mixtures of these surfactants are preferably used.

In addition, the detergent, cleaning agent or disinfectant cannot contain inorganic filler salt, preferably in amounts of not more than 50% by weight, in particular 1% by weight to 30% by weight, of heavy metal complexing agent, preferably in amounts 10% by weight, in particular from 0.1% by weight to 2% by weight, and further additives customary in disinfectants, cleaning agents, bleaching agents and washing agents, such as microbicides, enzymes, dyes and / or fragrances . Such constituents are each preferably present in amounts not exceeding 1% by weight, in particular from 0.05 to 0.5% by weight, based on the total composition.

The production of the means does not require any major technical effort. It can be done in a simple manner by mixing the powdered components. Simple mixing devices, such as paddle or drum mixers, are usually suitable for this. Even the use of automatically working Belt scales in combination with free-fall mixers are possible. The components can be used as individual components or in the form of premixes.

Examples

example 1

By spraying slurries containing about 35% by weight of water, which had been heated to 60 ° C to 70 ° C, under a pressure of about 60 bar and temperatures of the drying gas of 220 ° C to 230 ° C, the in Table 1 Powder P1 to P5 characterized by their composition. In a free fall, these were mixed with the amounts of sodium percarbonate and stabilizer indicated in Table 2, so that the detergents and bleaches M1 to M9 were formed as free-flowing, non-clumping powders with bulk densities of about 560 to 620 grams per liter . Their bleaching performance under washing conditions was in all

Table 1: Composition of the powder components by weight

^a ) 3 to 5 times ethoxylated

(Manufacturer Henkel)

-) Tetra-Na-hydroxyethane-l, l-diphosphonate (manufacturer Henkel) ^c ) acrylic acid / maleic acid copolymer (30:70), sodium salt (manufacturer BASF) Cases at least not worse than that of agents produced for comparison purposes, which contained sodium perborate instead of sodium percarbonate. For comparison in storage tests, the stabilizer-free agents VI to V5 were produced in the same way.

Table 2: Composition of the agents [% by weight]

^a ) Sodium percarbonate, active oxygen content 14% (manufacturer Interox) ^b ) N N'.N'-tetraacetylethylenediamine granules according to EP 037 026, 94 percent ^c ) N, N, N ', N'-tetraacetylethylenediamine powder

- ⁾ l, 5-diacetyl-2,4-dioxo-hexahydro-l, 3,5-triazine - granules, 77 percent (manufacturer Leuna Werke AG)

After storage periods of 16 weeks at 30 ° C. in water-impermeable plastic containers, the agents containing percarbonate stabilized according to the invention showed more than 60% or almost 90% (M7, M8, M9) of the activity of the sodium percarbonate used in each case, while the agents free of stabilizers only showed 10% to contained a maximum of 50% (V4, V5) of the sodium percarbonate used. Became even clearer the stabilizer effect at a storage temperature of 40 ° C under otherwise identical conditions; then the agents stabilized according to the invention contained more than 50% to more than 80% (M7), the comparative agents less than 10% to at most 30% of the percarbonate used.

Claims

1. Use of compounds which split off acetic acid under hydrolysis conditions for the stabilization of powdered percarbonate.

2. Use of compounds which release acetic acid under hydrolysis conditions as stabilizers for percarbonate in bleaching, washing, cleaning and disinfecting agents.

3. Use according to one of claims 1 or 2, characterized in that the compounds which split off under hydrolysis conditions are acetic acid from the group of N- or O-acetylated substances, including multiply acetylated alkylenediamines, acetylated glycolurils, N-acetylated hydantoins, hydrazides, triazines , Triazoles, urazoles, diketopiperazines, sulfurylamides, cyanurates and acetylated sugar derivatives and mixtures thereof are selected.

4. Use according to one of claims 1 to 3, characterized in that the compounds which split off under hydrolysis conditions acetic acid from the group comprising N, N, N ', N'-tetraacetylethylenediamine, 1,5-diacetyl-2,4-dioxohexahydro -l, 3,5-triazine, tetraacetylglycoluril, pentaacetylglucose and mixtures thereof are selected.

5. Use according to claim 4, characterized in that the compound which releases acetic acid under hydrolysis conditions is N, N, N ', N'-tetraacetylethylenediamine granulated with the aid of carboxymethyl cellulose and having average grain sizes of 0.01 mm to 0.8 mm.

6. Use according to one of claims 1 to 5, characterized in that the percarbonate to be stabilized is an alkali percarbonate, in particular sodium percarbonate.

7. Use according to claim 6, characterized in that the alkali percarbonate has an average particle size of 0.1 mm to 0.8 mm and a bulk density of 750 g / 1 to 1100 g / 1, in particular 850 g / 1 to 1000 g / 1.

8. Use according to one of claims 1 to 7, characterized in that the molar ratio of the compound which releases acetic acid under hydrolysis conditions to the percarbonate is in the range from 1:50 to 1: 2, in particular from 1:10 to 1: 2.