JPH03223400A - Bleaching composition - Google Patents

Abstract

PURPOSE: To provide a bleaching composition that is satisfactory stable without carrying out a stabilizing treatment with a percarbonate by adding a bleach activating agent and a bicarbonate, a sesquicarbonate, or a dihydrogen orthophosphate of an alkali metal in a specified ratio to a sodium percarbonate.

CONSTITUTION: The bleaching composition is made to be a stable bleach composition comprising (A) to 10 to 90 wt.% sodium percarbonate, (B) 4 to 40 wt.% bleach activating agent (e.g. a peroxy acid bleach precursor, N,N,N',N'- tetraacetyl ethylene diamine), and (C) 5 to 85 wt.% alkali metal bicarbonate, sesquicarbonate, or dihydrogen orthophosphate with the A/B weight ratio being 4.5 or more, the C/B weight ratio being at least 5:4 with the proviso that C≥20% when B>8 wt.%. A particular preferable composition having optimum stability and optimum performance comprises 40 to 60 wt.% A, 12 to 25 wt.% B, 20 to 50 wt.% C (sodium bicarbonate), and 0 to 15 wt.% D (sodium carbonate).

COPYRIGHT: (C)1991,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bleaching composition comprising essentially sodium percarbonate as persalt and a bleach activator for said persalt;
Said bleaching composition may optionally be used in admixture with a detergent composition, preferably in combination with a detergent composition, in order to improve the bleaching action of the washing liquor during washing, especially during washing at low temperatures of about 20-60°C. It can be used as a bleach additive to.

As used herein, the term "bleach activator" refers to an alkaline solution containing a hydrogen peroxide source (for example, a persalt), which is an oxidizing bleaching agent that is effective at low temperatures, unlike persalts and hydrogen peroxide. Refers to reactive organic compounds that generate acids. Therefore, these compounds are also referred to as peracid bleaching precursors, typical of which are N,NN',N'-tetraacetylethylenediamine (TAED), tetraacetylglycoluril (TAGU), acetoquine benzene sulfone. sodium acid (SABS), sodium nonanoyloxybenzenesulfonate (SNOBS) and sodium benzoyloxybenzenesulfonate (SBOB
S) is exemplified. Many other bleaching precursors are described in many publications, e.g. US Pat.
．． 882.4.1211.494.4.412.934
．． 4, 675.393 and 4.751. [5, G B
Patent 1.382.594.

EP-A-0,185,553,170,386,O,
174,132,0,12(1,591,0,284,
292,0,303,520,0,331,229 and 0.332.294.

Sodium perborate monohydrate or tetrahydrate is a persalt bleach that is currently widely used in and with laundry detergent compositions. Essentially Sodium Perborate Monohydrate or Tetrahydrate, TAED
Bleaching compositions containing urea and urea and used as bleaching additives are described in EP-Ao, 288.170.

Compositions containing such sodium perborate are relatively stable and can be formulated relatively easily. However, sodium 11um perborate is a boron compound that has been criticized for environmental reasons.

In the drive for new products, the present invention provides a more environmentally acceptable persalt salt, sodium carbonate perhydrate (Na CO 2 ), commonly known as sodium percarbonate.
-11/2 H2O2) is used. Using sodium percarbonate in place of sodium perborate is not a simple substitution. This is because, unlike sodium perborate, sodium percarbonate lacks stability.

In Japanese Patent Application No. 54-163906, 20% by weight
Detergent bleach compositions are described that include 10% by weight of sodium percarbonate, 40% by weight of heat-treated sodium bicarbonate, and 3% by weight of a bleach activator. In the case of this invention, in order to increase the stability, 1) sodium percarbonate must be used that has been heat treated at about 70-110°C for 10-120 minutes, and 2) the composition contains large amounts of succinic acid, citric acid. and maleic acid.

Another stability problem associated with compositions containing large amounts of sodium percarbonate and bleach activators is that they become self-heating during the manufacturing process, especially when the product is warmed.
ttiB) There is a risk.

Various methods have been proposed to stabilize or at least improve the stability of sodium percarbonate. For example, methods have been proposed for coating sodium percarbonate with borate-containing compositions, as described in GB Patent 2123.404.

Even so-called stabilized percarbonates, which are stabilized percarbonates in this way, cannot satisfactorily solve the problem of self-heating when used in bleach compositions containing bleach activators.

The stable and highly effective bleaching composition provided by the present invention consists essentially of (a) 10-90% by weight of sodium percarbonate; (b) 4% by weight of sodium percarbonate;
-40% by weight bleach activator, and (c) 5-85% by weight
an alkali metal bicarbonate, an alkali metal sesquicarbonate or an alkali metal dihydrogen orthophosphate, wherein the weight ratio of components (a):(b) is 4:5 or more and components (c):(b) ) is at least 5:4 and when component (b) is present in an amount greater than 8% by weight, the amount of component (c) is at least 20% by weight.

The present invention does not require the use of heat-treated sodium percarbonate.

It is also possible to use so-called stabilized percarbonates in the compositions of the invention, but the use of stabilized percarbonates only provides a slight improvement.

A major advantage of the present invention is that fully stable bleaching compositions can be formulated using untreated, substantially unstabilized sodium percarbonate.

It should also be noted that the present invention does not require the presence of acidic compounds in the amounts described in the above-mentioned Japanese patent specification. Accordingly, preferred compositions of the invention are substantially free of succinic acid, citric acid or maleic acid.

The alkali metal salt used as component (c) is preferably the sodium salt, i.e. sodium bicarbonate, sodium sesquicarbonate or sodium dihydrogen orthophosphate (Na
HPo 2H20), sodium bicarbonate and sodium sesquicarbonate are particularly preferred because they are phosphorus-free.

Sodium bicarbonate is also preferred in that it does not significantly affect the bleaching action of the composition over a given dosage range.

In addition to the above-mentioned components, sodium carbonate may be appropriately substituted for a portion of sodium bicarbonate in the composition of the present invention. Using up to an amount of sodium carbonate equal to the amount of sodium bicarbonate does not affect the stability of the composition. If desired, the compositions of the present invention may optionally contain a small amount of known ingredients commonly used in detergent or bleaching compositions, about 1
It may be incorporated in amounts up to 0% by weight, preferably up to 5% by weight. However, these optional ingredients must not affect the stability of the composition.

Preferred compositions of the present invention are highly concentrated bleaching compositions consisting essentially of (a) 30-85% by weight sodium percarbonate; (b) 5% by weight sodium percarbonate;
~30% by weight bleach activator, (c) 10-70% by weight sodium bicarbonate, and (d)
) 0-35% by weight of sodium carbonate.

To this composition, for example, about 1% by weight of colored detergent-based powder speckles may be added for product recognition. Preferred speckles are, for example, blue or green colored sodium carbonate particles.

A particularly preferred composition having optimum stability and optimum performance when used as a bleach additive consists essentially of (a) 40-60% by weight of sodium percarbonate, (b) 1
2-25% by weight bleach activator, (c) 20-50% by weight
of sodium bicarbonate, and (d) 0 to 15% by weight of sodium carbonate.

Bleach Activator As noted above, any bleach activator selected from a variety of peracid bleach precursors may be used in the compositions of the present invention. One preferred bleach activator is TAED, which is relatively harmless and commercially available. Other preferred bleach activators are 5
NOBS, 5BOBS, US Patent 4.751.015
, EP-A-0,331,229, EP-A-0,28
quaternary ammonium-substituted peracid bleach precursors as described in US Pat. No. 4,292 and EP-A-303,520;
2-Methyl-4H,3,1-benzoxazine-4- as described in EP-A-0,332,294
on, and these have high activity.

These bleach activators are - used in the form of solid crystals or are preferably made from finely crystalline peracid bleach precursors with a particle size of 150 μm or less.
It can be used in the form of 2.0 mm agglomerates or granules. The bleach activator in unprotected crystalline form can be used in very dry conditions, but in this case it is preferably present as coarse particles having a size of 0.2 mm or more. In the present invention, the bleach activator is preferably used in the form of aggregates or granules. Use of these forms of bleach activator minimizes direct contact with sodium percarbonate and prevents undesirable perhydrolysis during storage. Agglomeration and granulation methods are known and any known method can be used to produce bleach activator granules. For example, EP-AO, 240,057 and EP-A
Bleach activator particles such as those described in US Pat. No. 0,241,962 are very suitable for use in the present invention.

Sodium Percarbonate Any grade of sodium percarbonate can be used without pretreatment, but coarse grades are preferred.

Highly preferred sodium percarbonate comprises at least 6 of the particles.
0% by weight has a particle size greater than 250 μm. Preferably, other ingredients used in the composition also have similar coarse grades.

The bleaching compositions of the present invention may be prepared by simply mixing the dry ingredients using any suitable mixing equipment.

Example 1 The following bleaching composition was prepared using sodium percarbonate, TAED granules (
Composition: TAED83. (1% by weight, sodium sulfate 9
2% by weight, 23% by weight of 5okalan® Cr2-polymer, 2.3% by weight of bentonite clay and 3.2% by weight of water = trace salts) and crude sodium bicarbonate (
The average particle size>125 μm) was produced by dry mixing. Place the composition in a thermos flask and add 10
The temperature of the composition was monitored while placed in an oven at 0° C. for approximately 24 hours. This test investigated the possibility of self-heating.

The results are shown in Table 1.

In Table 1, compositions Nos. 1 to 13 are the compositions of the present invention, and are compositions! io, 14-26 are compositions outside the present invention.

Table 1 From the above results, the temperature rise in the compositions of the invention is relatively slow, and the temperature rise in the compositions outside the invention is relatively to very fast.

This confirms that the compositions of the present invention are very stable compared to compositions other than the present invention, which have fast or very fast exothermic decomposition rates.

Example 2 A 68/12/20 composition was made using 20% of various diluent materials. For these compositions, Example 1
Similarly, an exothermic decomposition test at 100°C was conducted.

The results are shown in Table 2.

From the results shown in the table above, it is recognized that compositions Nos. 061 and 2 of the present invention exhibit superior stability compared to compositions Nos. 3 to 8 outside the present invention.

Example 3 This example demonstrates the effectiveness of the bleach additive of the present invention in a cleaning system containing a main cleaning powder and a builder additive.

Bleach additive Sodium percarbonate Sodium bicarbonate TAED granules (83% active by weight) Blue speckles (in main wash powder) Main wash powder (spray dried) Linear alkylbenzene sulfonate Nonionic surfactant Zeolite (anhydrous) Sodium silicate carbonate Sodium acrylic acid/maleic acid copolymer Sodium carboxymethylcellulose protease Antifoaming ingredient Trace ingredients, salts, water weight% 52.5 29, O 17.5 0 100, 0 weight% ■42 6.2 37.7 2 .2 68 6.2 8 6 1.1 14.2 +nn n Builder additive (dry mix) Weight Tazeolite A (anhydrous basis) 58.82 Sodium carbonate 179 Sodium sulfate 2.23 Sodium hydroxide 0.38 Citric Sodium acid 5.0 Nonionic surfactant
2.0 Sodium Carboxymethyl Cellulose 154 Flavor
01 Wednesday
I232 Using a turbotometer heated to a maximum of 60°C, the cleaning effect was measured on two bleach-sensitivity test cloths, one with bleach additive and one without bleach additive, to determine the extreme water hardness. A comparison was made.

The results are shown in Table 3.

Table 3 Conditions Water hardness ('FH) 7 46 Water hardness ('D) r) 4 24 Main cleaning powder dose (g/l) 4 4 Builder dose (
g/l) 0 3 Increase in reflectance (ΔR*) 60 Test cloth 1 (cotton cloth with tea stains) Bleach Og/I 1.51 3.41
1g/l 15.41 20.112g
/ 1 17.61 25.51 Test cloth 2 (cotton cloth with red wine stain) Bleach Og/I 15.46 14.
961g/l 35.16 39.4
62g/l 35.06 41.06
Example 4 In this example, the effectiveness of washing using the bleaching additive of the present invention was compared to washing using a commercially available bleaching detergent composition.

ll! 1els™ 765 washing machine at 60°C cycle, using 30″ (French) hardness water.
．． 5 kg of clean cotton sheets and terry towels were washed and written together. Two types of blood-stained test fabrics were used to test the cleaning effectiveness: Test Fabric 3 (cotton fabric stained with non-coagulable blood) and Test Fabric 1 (cotton fabric stained with blood/milk/ink).

Washing was carried out three times as shown below.

Example 4 Pre-cleaning: Main cleaning powder (Example 3) 55g
Builder Additive (Example 3) 20g Main Wash, Main Wash Powder (Example 3) 100g Builder Additive (Example 3) 20g Bleach Additive (Example 3)
45g Comparative Example A Main washing without pre-washing: Commercially available bleach detergent powder A 10g (contains sodium perborate + TAED) Comparative Example B

Claims (7)

[Claims] (1) A stable bleaching composition comprising a persalt and a bleach activator, consisting essentially of (a) 10 to 90% by weight sodium percarbonate, (b) 4 to 40% by weight bleach activator, and ( c) 5 to 85% by weight of alkali metal bicarbonate, alkali metal sesquicarbonate or alkali metal dihydrogen orthophosphate, and the weight ratio of components (a):(b) is 4:5 or more; and characterized in that the weight ratio of component (c):(b) is 5:4 or more, and when component (b) is present in an amount greater than 8% by weight, the amount of component (c) is at least 20% by weight. bleaching composition. (2) The bleaching composition according to claim 1, wherein the sodium percarbonate is not heat-treated. (3) The bleaching composition according to claim 1 or 2, which is substantially free of succinic acid, citric acid, or maleic acid. (4) essentially (a) 30-85% by weight sodium percarbonate, (b) 5-30% by weight bleach activator, (c) 10-70% by weight sodium bicarbonate, and (d) 0 4. A bleaching composition according to any of claims 1 to 3, characterized in that it comprises ~35% by weight of sodium carbonate. (5) Essentially (a) 40-60% by weight of sodium percarbonate; (b) 12-25% by weight bleach activator; (c) 20-50% by weight of sodium bicarbonate, and (d) 0-15% by weight of sodium carbonate; The bleaching composition according to claim 4, characterized in that it comprises: (6) A bleach composition according to any one of claims 1 to 5, characterized in that the bleach activator is a peracid bleach precursor. 7. The bleaching composition of claim 6, wherein the peracid bleaching precursor is N,N,N',N'-tetraacetylethylenediamine (TAED).