JP2562064B2 - Bleaching composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to concentrated liquid bleaching compositions suitable for sale and use as household bleaches. A pourable household bleach is obtained by containing one or more surfactants that act to thicken the solution in the presence of an electrolyte to make it more viscous than water. Often thickened. Thickening of the pourable household bleach helps the user to control the dispersion of the composition, delaying its release from the surface to which it is applied. The present invention relates to such compositions containing surfactants and electrolytes to increase viscosity. The compositions of the present invention may be pourable, or may be of higher viscosity so as not to be easily poured.

Household bleaches need to be sufficiently stable so that most of the bleach does not lose its activity during storage between manufacture and use. Prior to the present invention, commercial liquid bleaching products often utilized hypochlorite as a bleaching agent.

It is well known that hydrogen peroxide is unstable in the absence of stabilizers. Stabilizers prevent decomposition catalyzed by transition metal ions. Hydrogen peroxide exhibits a good bleaching action when used under alkaline conditions. However, stabilization of hydrogen peroxide under alkaline conditions was difficult and therefore commercial solutions of hydrogen peroxide were generally acidic for stability. Certain phosphonates capable of stabilizing hydrogen peroxide in alkaline solutions are described in European Patent B-98.
No. 39 (Unilever).

The presence of the electrolyte tends to cause decomposition of the alkaline hydrogen peroxide solution. For example, a 4% by weight solution of hydrogen peroxide made alkaline at pH 10 and containing 0.25% ethylenediaminetetramethylenephosphonic acid (not as effective as the phosphonate of EP-B3939) as a stabilizer. Was found to retain 95% of its hydrogen peroxide after storage for 2 weeks at 37 ° C. On the other hand, if the solution contains 1% by weight sodium chloride, 85%
Or less hydrogen peroxide remained, while about 50% if the solution contained 10% by weight sodium chloride
Of hydrogen peroxide remained. Similar results were observed when sodium tripolyphosphate was used rather than sodium chloride as the added electrolyte. Doubling the amount of phosphonate stabilizer has little effect on the degradation rate.

Therefore, conventional attempts to make surfactant-enriched alkaline household liquid bleaching products using hydrogen peroxide as a bleaching agent require the presence of some electrolyte to enrich the solution, but This electrolyte could face the problem of helping to accelerate the decomposition of the peroxide.

However, the inventors have found that it is possible to formulate an aqueous alkaline solution of hydrogen peroxide, which is concentrated with surfactants and electrolytes, but is still stable enough to be used as a commercial product.

The present invention is hydrogen peroxide, the stabilizers, surfactants other than the electrolytes, and: a) mixing a compound of formula: R (OC ₂ H ₄₎ in _n -OSO ₃ M (wherein, R is alkyl of 8 to 20 carbon atoms The average value of n is
0.5 to 12, preferably 1 to 6, M is any of alkyl ether sulfates of the a) solubilising cation or b) C ₈ -C ₂₀ alkanesulfonates or C ₈ -C ₂₀ alcohol sulfates, A liquid bleaching composition comprising an aqueous alkaline solution containing a surfactant selected from: a combination of an anionic surfactant and a nonionic or amphoteric surfactant.

It has been found that the use of surfactants similar to those described above is beneficial in achieving thickening at much lower electrolyte concentrations.
This allows the electrolyte to be provided by the ions present in the composition for other reasons, without the need to add salt for the sole purpose of increasing ionic strength. Aside from consideration of peroxide stability, the advantages of low electrolyte concentration are:
To reduce the tendency of the product to leave streaks on the surface it cleans.

When the surfactant is the combination of the above (b), what is considered to be preferable as the nonionic / amphoteric surfactant is an amine oxide surfactant, preferably having 8 to 12 carbon atoms.
It is a trialkylamine oxide having one long chain alkyl of 20 and two alkyl groups having 1 to 4 carbon atoms. At that time,
When the primary alcohol sulphate is an anionic surfactant, the weight ratio of amine oxide: alcohol sulphate is preferably 82:18 to 65:35, and better 80:20 to 65:35. It may be: 20-70: 30.

Alkane sulfonates are preferred over alcohol sulfates. Because the viscosity in that case is hardly affected by the change in the composition, and it becomes easy to produce the final product having a reproducible viscosity. The weight ratio of amine oxide to alkane sulfonate (if used) is preferably in the range 80:20 to 50:50, or better 80:20 to 65:35, and preferably 70: 30-65:
35 is a narrower range.

One or more additional surfactants may be included within the scope of this invention. Of total composition to the total concentration of surfactant
It may be in the range of 0.75 to 6% by weight, especially in the narrower range of 0.75 to 3% by weight, if the composition is pourable. Concentrations above 6% by weight may be used, but are less preferred.

The electrolyte concentration in the composition of the present invention may be such that the total amount of salts other than the surfactant is 7% by weight or less, and more preferably 5% by weight or less or 3% by weight or less. The electrolyte level may be such that it exhibits an electrolyte concentration in the range 0.05 to 0.30 molar, preferably 0.1 to 0.2 molar.
Again, higher concentrations may be used, but less preferred.

The stabilizer for hydrogen peroxide may be a phosphonate sequestering agent similar to EP-B-9839, which has the general formula: Where n = 1 to 4; X is H or a water-soluble cation selected from the group consisting of alkali metals, ammonium, substituted ammonium and alkaline earth metals. 0.01 to 1 such a sequestering agent
You may use it in the quantity of weight%. This is about 1.5 x 10 ^-4 to 2 x 1
0 ^-2 mol.

These compounds are effective in blocking ion-catalyzed decomposition, but less effective in manganese. It has been discovered that contamination with trace amounts of manganese can be prevented (eg, using sufficiently pure raw materials) so that a separate stabilizer for manganese may not be needed. However, if desired, another stabilizer which blocks the action of manganese may be the phosphate used in an amount of 0.5-4% by weight, preferably 1-3% by weight (calculated as the anhydrous salt). . Tetrasodium pyrophosphate may be used as such a salt.

Another stabilizer that has been found to be effective in alkaline solutions against degradation caused by transition metals containing both iron and manganese is colloidal stannic oxide hydrate.

In solution as a product of hydrolysis of soluble tin compounds
It is preferred to form this stabilizer in situ. Various tin compounds including tin sulfate, sodium stannate, tin dichloride and tin tetrachloride are added to the solution to hydrolyze,
Stannic oxide may be formed.

Suitable concentrations of tin compounds in the composition may range from 10 ⁻⁴ to 10 ⁻² mol, preferably 3 × 10 ^{−3 to} 6 × 10 ⁻³ mol. The amount of tin compound should not actually be more than necessary, as its excess can itself cause peroxide decomposition. Tin compounds (or any stabilizer) by testing solutions with various concentrations of stabilizers and analytically measuring the amount of hydrogen peroxide remaining after storage.
The optimum concentration of can be determined.

A suitable viscosity for a pourable composition that has the appearance of a concentrated liquid is
40-250 centipoise (0.05-0.25 Pa.sec), preferably about 100 centipoise (0.1 Pa.sec) dynamic
Viscosity. High viscosity liquids having viscosities of 250 to 1000 centipoise or higher are also within the scope of the invention.

Since the compositions of the invention are generally aqueous, they usually have a specific gravity close to 1. Therefore, the kinematic viscosity value (Stokes) is numerically almost the same as the dynamic viscosity value (Poise). Dynamic viscosity expressed in Pascal-sec is m ² · sec ^-1
It is approximately 1000 times the kinematic viscosity represented by.

The pH of the solution is preferably 8.0 to 10.5, and better still
It is 8.5 to 9.8 or 8.5 to 10.0. When using a phosphonate stabilizer, it is more preferable to have a narrower range of 9.2 to 9.8, while when using colloidal stannic oxide as a stabilizer, a slightly lower pH in the range of 8.7 to 9.3. Is preferably used. A buffer may be included to maintain the pH at the desired value, but this may not be necessary. Phosphate, if present, exhibits a buffering effect. Another compound that can be used for this purpose is borax.

The concentration of hydrogen peroxide in the composition of the present invention, calculated as pure H ₂ O ₂ , is desirably 1 to 15% by weight, preferably 2 to
It is in the range of 10% by weight.

Example 1 A formulation containing the ingredients shown in Table 1 below was prepared.
The composition was stored in a plastic bottle at 37 ° C. From time to time, aliquots were removed and titrated with potassium permanganate to measure the residual hydrogen peroxide level. The results are shown in Table 1.

The viscosity of these formulations was found to be about 100 cS as measured using a Ubbelohde capillary viscometer.

Example 2 The procedure of Example 1 was repeated with the formulation containing equal amounts of hydrogen peroxide, surfactant, perfume and dye. 6 × with and without 3% borax decahydrate
Various tin compounds were used at a concentration of 10 ^-3 molar. A glass bottle was used, which is somewhat harmful for stability. In all cases, the pH was initially 9.6. 2
The proportion of hydrogen peroxide remaining after 8 days was as follows: Borax and SnCl ₂ 68% Borax and Na ₂ SnO ₃ 47% Borax and SnSO ₄ 45% Na ₂ SnO ₃ (without borax) 96% SnCl ₄ (without borax) 68% Example 3 A range of formulations was prepared, all of which included: Hydrogen peroxide 5.0% (calculated as anhydrous) tetrasodium pyrophosphate decahydrate. Substance 3.0% (approx. 1.8% when calculated as anhydrous product) European Patent 9839 Phosphonic acid 0.3% Salt stabilizer Perfume 0.1% Sodium hydroxide up to pH 9.6 Concentration system Various types of water remaining 100% Concentration The system used various components, but varied in the properties and total amount of materials used.

The thickening system was sodium lauryl sulphate (SLS) or sodium alkane sulphonate (SAS) (which was in principle a secondary alkane sulphonate derived from a C ₁₃ -C ₁₈ n-alkane mixture. ) Containing tallow dimethylamine oxide (AO).

The viscosity of the formulation was measured using a Ubbelohde capillary viscometer. The results obtained are shown in the attached drawings.

Figure 1 shows the total amount of AO + SLS from 1.1% by weight of the composition to 1.
Figure 9 shows the variation of viscosity with respect to the proportion of SLS in the AO / SLS mixture when varying up to 9% by weight.

Figure 2 shows the total amount of AO + SAS from 1.2% by weight of the composition to 2.
Figure 4 shows the viscosity variation for AO / SAS mixtures when varied up to 6% by weight. It is observed that the viscosity peak is broad and the maximum viscosity is hardly affected by the variation of the total amount of AO + SAS. For example, in Figure 1, the concentration of surfactant to have a viscosity of 100 cS is 1.2%, from 0.2%
An increase of up to 1.4% doubles the viscosity to 200 cS. In Figure 2, 1.4% total surfactant shows a viscosity of 100 cS.
Viscosity increases to 150cS when increased by 0.2%, but 200cS
To achieve this, it is necessary to further increase the amount to 1.8%.

Example 4 As a surfactant, a compound represented by the general formula: R (OC ₂ H ₄ ) _n OSO ₃ Na (wherein the alkyl group R is a C ₁₂ and C ₁₃ linear alkyl group, and n has an average value of 3) A number of formulations were prepared using the linear alkyl ether sulphate of). Also included in these formulations was the phosphonate stabilizer of EP 9838. Others used stannous chloride, which is hydrolyzed in situ to form colloidal stannic oxide hydrate. The stability of the peroxide was monitored as in Example 1. Viscosity was measured at a shear rate of 21 sec ^-1 using a Haake RV2 rotational viscometer suitable for measuring the viscosity of pourable household bleach products. The formulation is shown below: The amounts of alkyl ether sulfate and sodium chloride in the various formulations are shown in the table below along with the observed results.

Example 5 An alkaline solution of hydrogen peroxide containing a surfactant, sodium chloride and stannic chloride that hydrolyzes to form colloidal stannic oxide hydrate was prepared.

Two surfactants were used. The amounts of surfactant and sodium chloride were such that they produced a sufficiently high viscosity to be desirable as a pourable "concentrate" type bleach. Smaller amounts could be used to produce a "concentrate" type of bleach.

In each case, the initial concentration of hydrogen peroxide was 4% by weight, calculated as anhydride. The solution was made alkaline with sodium hydroxide to pH 10.

Stannic chloride was used at a concentration of 2.3 x 10 ^-3 molar.

There surfactant system is constituted of a C ₁₂ -C ₁₄ alkyl dimethyl amine oxide and 4.5 wt% of sodium lauryl sulfate 4.5 wt%. It was used with 9% strength by weight sodium chloride.

The second surfactant system consisted of 5% by weight C ₁₁ -C ₁₅ secondary alcohol ethoxylated with an average of 3 ethylene oxide residues and 5% by weight sodium lauryl sulphate. This combination was used with 3.37% by weight sodium chloride.

The solution was stored at 40 ° C. and the amount of residual hydrogen peroxide was measured occasionally. The amount of hydrogen peroxide remaining was 80-85% with any combination of surfactants.

Turned out to have.

[Brief description of drawings]

Figure 1 shows the total amount of AO + SLS from 1.1% by weight of the composition to 1.9
Figure 3 shows the variation of viscosity with respect to the proportion of SLS in the AO / SLS mixture when varying up to wt%. Figure 2 shows the total amount of AO + SAS from 1.2% by weight of the composition to 2.6
Figure 3 shows the variation of viscosity for AO / SAS mixtures when varying up to wt%.

Claims (3)

(57) [Claims] 1. A hydrogen peroxide of 1 to 15% by weight, a stabilizer for hydrogen peroxide of 0.01 to 4% by weight, an electrolyte other than a surfactant of 0.05 to 0.30 mol and 5% by weight or less, and 0.75 to 3 wt%, a combination of a C ₈ -C ₂₀ anionic surfactant is either alkanesulfonate or C ₈ -C ₂₀ alcohol sulfates and amphoteric surface active agents, containing
A liquid bleaching composition comprising an aqueous alkaline solution having a pH of 8.0 to 10.5. 2. The composition of claim 1 wherein said stabilizer is colloidal stannic oxide hydrate. 3. The stabilizer has the formula: The compound according to claim 1, wherein n = 1 to 4; X is H or a water-soluble cation selected from the group consisting of alkali metals, ammonium, substituted ammonium and alkaline earth metals. Composition.