JPH031359B2 - - Google Patents

Abstract

Low sudsing detergent compositions are manufactured by the use of anionic detergent active sulphate compounds selected according to their calcium salt solubility product and their critical micelle concentration, and by the use of a non-soap anti-foam compound. Preferred anionic sulphates are the primary and secondary alkyl sulphates having particular carbon chain length distributions, and a preferred non-soap anti-foam is an alkyl phosphate ester, desirably used in conjunction with a hydrophobic wax or oil.

Description

[Detailed description of the invention]

The present invention relates to detergent compositions for washing textiles. It is now common practice to formulate detergent compositions for use in front-loading washing machines to be low-foaming compositions. The most common type of low-foaming composition is the so-called "three-component"
products based on mixtures of anionic and nonionic surfactants, most commonly long-chain alkylbenzene sulfonates, which are also part of the components that make up water hardness. These products use calcium soaps formed in situ by the reaction of calcium ions with sodium salts of fatty acids to control foaming ability. Nonionic surfactants also provide foam control in these formulations while contributing to the cleaning properties of the system. For example, “Persil
The cleaning power obtained from the above compositions, as embodied in products such as ``Automatic'' and ``Bold Automatic'' (both registered trademarks), is completely satisfactory. By carefully selecting the anionic surfactant, we have created a detergent composition that does not require the presence of a nonionic surfactant and yet exhibits the same cleaning power and foam control as three-component products. It was discovered that it was possible to produce At the same time, the use of long-chain alkylbenzene sulfonates, which are undesirable from an environmental point of view, is also avoided. According to the invention, with a non-soap antifoaming agent, (a) the calcium salt solubility product is greater than 1 x 10 ^-12 mol ³ l ^-3 , (b) the maximum critical micelle concentration is 6 x 10 ^-2 g / is. Detergent compositions are provided that include anionic sulfate surfactants or mixtures of such surfactants. The importance of parameters a and b when selecting an anionic surfactant for use in the present invention is summarized as follows. Calcium salt solubility product is a measure of the tendency of a substance to precipitate from a solution containing calcium ions and anionic surfactant ions. Precipitation boundary control is critical in the absence of non-ionic surfactants that promote solubilization of other surfactants in standard two- or three-component detergent formulations. be. It is natural that the point at which maximum surfactant is obtained for a material is determined by the critical micelle concentration. For purposes of the present invention, both the solubility product and the critical micelle concentration are measured at 60° C. in the presence of 0.05 mol/sodium chloride. Those skilled in the art will appreciate the distinction between sulfate surfactants that are within the scope of the present invention and those that are outside the scope of the present invention by reviewing Tables 1 and 2 below. Table 1 K _SP Ca ⁺⁺ ×10 ^-12 mol ³ l ^-3 C ₁₆ - C ₁₈ (EO) ₄ -Sulfate 1000 C ₁₄ Secondary alkyl-2-sulfate 230 C ₁₆ Secondary alkyl-2-sulfate 30 C ₁₂ ~C ₁₅ Primary alcohol sulfate 30 C ₁₆ ~ _{C 18} Highly crystalline fraction secondary alkyl sulfate 8.7 Tallow alcohol (EO) ₁ -sulfate 5.8 C ₁₈ Secondary alkyl-4-sulfate 5.2 C ₁₄ ~C ₁₅ Primary alkyl sulfate 3 C ₁₅ - C ₁₆ Primary alkyl sulfate 1.6 C ₁₈ Secondary alkyl-2-sulfate 1.3 C ₁₆ - _{C 18} Primary alcohol sulfate 0.02 Table 2 Critical micelle concentration × 10 ^-3 g/ C ₁₄ Secondary alkyl-2-sulfate 140 C ₁₂ - C ₁₅ Primary alkyl sulfate 130 C ₁₄ - C ₁₅ Primary alkyl sulfate 53 C ₁₆ Secondary alkyl-2-sulfate 20 C ₁₅ ~C ₁₆ Primary alkyl sulfate 19 C ₁₆ ~ _{C 18} Highly crystalline fraction Secondary alkyl sulfate 10 Tallow alcohol (EO) ₁ -Sulfate 10 Alphaol 16-18 (EO) ₄ -Sulfate 10 C ₁₈ Secondary alkyl-4-sulfate 5 C ₁₈ Secondary alkyl-2-sulfate 5 C ₁₆ -C ₁₈ Primary alkyl sulfate 5 As mentioned earlier, mixtures of different detergent-active sulfates can also be combined with the solubility product of the mixture. It can be used as long as the critical micelle concentration is within the required range. The anionic surfactant accounts for 5% of the composition by weight.
to 35%, preferably from 5 to 25% due to cost considerations
% can be included in the mixture. Anionic surfactants for the present invention are sulfates rather than sulfonates, since sulfates are generally much more biodegradable than sulfonates. Preferred among the sulfate types are primary and secondary alkyl sulfates. Most preferred are highly crystalline fraction secondary alkyl sulfates (i.e. those containing a high percentage of substances with sulfate groups attached in the 2 or 3 position), especially C _16-18 sulfates and
It is a _C15-16 primary alkyl sulfate. The second essential ingredient in the compositions of the present invention is a non-soap antifoam compound. Typical non-soap antifoam compounds are phosphate esters, which may be used alone or with waxes or hydrophobic oils such as mineral or vegetable oils. We also have silicone defoamers and sym
-Nitrogen-containing heterocyclic compound derivatives such as triazines can also be used. In general, the non-soap anti-foam compounds of the present invention range from 0.05%, which is considered the lowest amount that can be effective, to the extreme potency of most non-soap anti-foam compounds.
efficacy), their cost, and the need to leave as much room as possible for other compounds in the composition, which is considered to be the maximum in practice.
It can be included in the composition in amounts up to %. More specifically, the phosphate esters, which can optionally also be used in salt form, have the following general formula: In the above formula, A is -OH or R ₂ (EO) _n -, and R ₁ and R ₂ are the same or different groups.
_C12 - _C24 , preferably _C16 - _C22 straight-chain or branched, saturated or unsaturated alkyl groups, especially C16- _C22
represents a linear saturated group of C ₁₈ and m and n
are the same or different numbers and represent 0 or an integer from 1 to 6. It is preferred that A is -OH and n is 0 so that the compound is a monoalkyl phosphoric acid with preferably straight chain alkyl groups. If ethylene oxide (EO) groups are present in the alkyl phosphate, they should not be too long relative to the length of the alkyl chain so that the calcium or magnesium salt becomes insoluble in use. In practice, the alkyl phosphate compound is usually a mixture of mono- and dialkyl phosphoric acids of limited alkyl chain length. Phosphates containing mainly monoalkyl are usually produced by phosphorylating an alcohol, or an ethoxylated alcohol when n or m is 1 to 6, using polyphosphoric acid. Alternatively, phosphorylation can be carried out using phosphorous peroxide;
In that case a mixture of mono- and dialkyl phosphates is produced. Under optimal reaction conditions, only small amounts of unreacted substances or by-products are formed, so there is the advantage that the reaction products can be used directly in detergent compositions. If a mixture of a phosphate ester and a wax is used as the non-soap antifoam compound, the wax may be of synthetic, mineral, vegetable or animal origin. The standard melting point of wax is between about 20°C and about 120°C, preferably below about 90°C, especially from about 30°C to about 70°C.
The temperature should be within the range of up to 0.degree. C., ie below the maximum wash temperature intended for the detergent composition. If waxes with melting points exceeding the intended maximum washing temperature are used, they must be sufficiently dispersed in the washing liquid by appropriate kneading operations into the original detergent composition. There is a need. Preferred waxes are those derived from minerals, particularly those derived from petroleum, including petroleum-based microcrystalline waxes and their oxidized versions, petroleum jelly ("petrolatum") and paraffin waxes. To be precise, petroleum jelly is a semi-solid wax that usually has a melting point of about 30 DEG to 40 DEG C., but for convenience it is referred to herein in conjunction with other solid waxes. Fischer-Tropsch
Synthetic waxes, such as wax and oxidized versions thereof, Montan waxes, or natural waxes, such as beeswax, candelilla wax, and carnauba wax, may be used if desired. Any of these waxes can be used alone or in combination with other waxes. The wax should be easily dispersible in the cleaning solution, but not soluble therein, and should not have an extremely high saponification number, which should not exceed about 100. It is. It is advantageous to include emulsifying or stabilizing agents for waxes in detergent compositions. Examples of suitable oils which may be used if desired include vegetable oils such as sesame oil, cottonseed oil, corn oil, sweet almond oil, olive oil, malt oil, rice bran oil or peanut oil, or lanolin, oxfoot oil, bone oil, cornstarch oil, etc. There are animal oils such as whale oil or cod liver oil. It goes without saying that any oil used must not be too dark in color, have a strong odor, or be otherwise unsuitable for use in detergent compositions. The remaining ingredients of the composition are conventional and the amounts used are conventional. Some suitable cleaning builders that are well known commercially available products include Ortho,
In addition to sodium pyro- and tripolyphosphates, many others have been described in the literature, especially in recent patent specifications, as alternatives to these phosphate-based materials. Other cleaning builders which may be mentioned by way of example include alkali metal carbonates, in particular sodium carbonate, alkali metal polyphosphonates such as sodium ethane-1-hydroxy-1,1-diphosphonate, alkali metal amine carboxylates, For example, sodium nitrilotriacetate and sodium ethylenediaminetetraacetate, alkali metal ether carboxylates such as sodium oxydiacetate, sodium carboxymethyloxysuccinate, sodium carboxymethyloxymalonate and their congeners, alkali metal citrates, alkali metal ether carboxylates, Mellistate salts, and salts of polymeric carboxylic acids such as sodium polymaleate, copolyethylene maleate, polyitaconate and polyacrylate. When using sodium carbonate as a cleaning builder, British patent no.
It is advantageous to include certain types of calcium carbonate having a surface area of at least about 10 m ² /g, as described in US Pat. No. 1,437,950. Another type of detergent builder, which can be used alone or in admixture with other builders, is a cation exchange material, especially alumino It is sodium silicate. Preferred materials of _this type have the formula: ( _Na2O ) _{0.7-1.1.Al2O3} ( _SiO2 ) _1.3-3.3 and _are amorphous or crystalline, usually about 10-3.3, depending on drying conditions. It has an amount of bound water of 30%. Of course, sodium aluminosilicate materials of this type must be finely divided to minimize deposits on fabrics during laundering. The amount of cleaning builder used is from about 5% to 80%, preferably about 10% by weight of the composition.
to about 60% is standard, and the weight ratio of detergent builder to detergent active compound used is generally about
The amount is 10:1 to 1:5 parts by weight. The detergent compositions of the invention can be in any conventional physical form, but are preferably solid compositions, such as powders, granules, flakes, ribbons, noodles or tablets, or liquid or paste compositions. It can also be in the form of The detergent compositions can also be prepared using any conventional detergent manufacturing method, and in the case of preferred powder detergent compositions, particularly slurry manufacturing techniques and spray drying techniques. The detergent compositions of the present invention may also contain any of the customary additives in amounts normally used in detergent compositions. Examples of these additives include powdered flow aids such as finely divided silica and aluminosilicates.
antiredeposition agents such as sodium carboxymethylcellulose; oxygen-releasing bleaches such as sodium perborate and sodium percarbonate; Acid bleach precursors, such as trichloroisocyanuric acid, and chlorine-releasing bleaches such as alkali metal salts of dichloroisocyanuric acid, fabric softeners such as smetite and illite type clays, anti-ashing aids. ,starch,
Slurry stabilizers, such as anhydrous co-polyethylene maleic acid and anhydrous co-polyvinyl methyl ether-maleic acid; inorganic salts, such as sodium silicate and sodium sulfate, usually used in salt form, and usually in very small amounts. These include fluorescent agents, fragrances, enzymes such as proteolytic and starch-degrading enzymes, fungicides and coloring agents. The detergent composition typically has an alkaline PH in the range of PH 9-11, which preferably includes alkaline salts, particularly sodium silicates, such as meth, in an amount up to about 15% by weight. This is achieved by including neutral or alkaline silicates. The present invention will be explained below with reference to examples, in which the numbers in the examples and percentages indicate weight unless otherwise specified. Example 1 A series of textile laundry powders with the following formulations were prepared by spray drying and postdosing techniques. Weight% Anionic detergent* 14.0 Sodium tripolyphosphate 33.0 Alkaline sodium silicate 6.0 Sodium perborate 19.0 Sodium sulfate 17.0 Sodium carboxymethyl cellulose 0.5 Non-soap antifoaming compound ⁺ 1.5 Add water to make 100. *Anionic detergents used in each formulation are shown in Table 3. + The non-soap antifoam agent is an 80:20 mixture of (i) petroleum jelly and (ii) Alf5®, a mixture of mono and sodium salts of -C ₁₆ alkyl phosphates.
It was a mixture. These powders were used to wash polyester cotton test cloths soiled with dirt consisting of a mixture of inorganic substances and synthetic sebum. The effectiveness of the detergent was determined by measuring the reflectance of the washed fabric and expressing this as a percentage of the reflectance of the fabric before soiling. The washing operation is carried out within Tergotometers®.
This was done using water at 40° French hardness, a temperature of 60°C, a product concentration of 0.15%, and an agitation rate of 50 cycles per minute. Table 3 shows the results.

[Table] Example 2 A powder detergent with the following formulation was prepared using a spray drying method and a post-dosing method. Weight% Anionic detergent 14.0 Sodium tripolyphosphate 33.0 Alkaline sodium silicate 6.0 Sodium sulfate 19.0 Sodium perborate 19.0 Add water to make 100%. In one of the powders, the anionic detergent is a sodium salt of a C ₁₆ to _{C 18} highly crystalline fraction secondary alkyl sulfate (SALS), and in the other, a C _12.5 alkylbenzene. The sodium salt of sulfonate (DOBS-055) was used,
It is produced by sulfonation of dodecylbenzene and is available from Shell Chemicals Ltd. as DOBS-055. The naturally soiled cotton articles were divided into two halves and washed in a Hotpoint® washing machine. The wash time was 10 minutes, the fabric to liquid ratio was 2.3 Kg to 37, and the temperature was 55°C. One half of each divided fabric product was washed with a powder containing SALS, and the other half was washed with a powder containing DOBS-055. A total of 18 products were divided into two for each set of conditions and used in six tests. After washing, the test pieces were evaluated by professional evaluators. The results are shown in Table 4.

EXAMPLE 3 The same experiment as described in Example 2 was carried out, except that a pair of powders contained the sodium salt of C _15-16 primary alkyl sulfate (D56) and DOBS-055. The results are shown in Table 5.

Table: None of the powders tested in Examples 2 and 3 contained a non-soap antifoam agent, but even with the exclusion of this, a comparison of the cleaning power exhibited by the two products. It seems unlikely that it would have much of an impact. Example 4 Two textile washing powders with the following formulations were prepared by spray drying and dry dosing.

[Table] In a Miele W 429 washing machine, with a naturally soiled cotton load of 5 _1b (=2.3Kg),
Foaming was investigated under actual conditions. The main washing (95°C) program was selected, 100g of powder was weighed out, and cold water with a hardness of 24° (London type) was supplied to the washing machine. In addition to the powders described above, Persil Automatic®, a well-known and conventional low-foaming textile laundry powder, was included in this test. The results were as follows. The suds height was measured every 3 minutes using a random index finger at the window of the washing machine. The results are shown in Figure 1 of the drawing, and from this figure approximately 35
Powder B shows the same foaming properties as Persil Automatic until after about 12 minutes of washing, while powder A, which does not contain a non-soap antifoam agent, shows the same foaming properties as Persil Automatic after about 12 minutes.
It can be seen that the foaming level exceeded that of Automatic.

[Brief explanation of the drawing]

FIG. 1 is a graph comparing the foaming properties of a detergent composition according to the present invention to that of a control detergent composition.

Claims (1)

[Claims] 1 C ₁₆ to _{C 18} secondary alkyl sulfate and
A low-foaming detergent composition comprising an anionic sulfate surfactant selected from _C15 to _C16 primary alkyl sulfates together with a non-soap antifoaming agent. 2 The anionic sulfate surfactant
The detergent composition according to item 1 above, containing in a proportion of 25% by weight. 3. The detergent composition according to item 1 or 2 above, which contains the non-soap antifoaming agent in a proportion of 0.05 to 5% by weight. 4. The detergent composition according to item 1, 2 or 3 above, wherein the non-soap antifoaming agent is a phosphate ester. 5. The first above, wherein the non-soap antifoaming agent is a mixture of a phosphoric acid ester and a hydrophobic wax or oil.
The detergent composition according to item 1, 2 or 3. 6. The detergent composition according to item 5 above, wherein the wax is petroleum jelly with a melting point of 30 to 40°C.