CH640261A5 - Detergent and its use for washing textiles - Google Patents

Description

The invention relates to a particulate alkaline detergent containing an alkali metal hydrogen orthophosphate, a carbonate, bicarbonate or sesquicarbonate of an alkali metal and a surfactant, and to its use in the form of a 0.1% by weight solution which has a pH between 9.25 and 10.5, for commercial washing of textiles.

The most widely used detergent builders are the condensed phosphates, especially sodium tripolyphosphate, but it has been pointed out that the use of phosphate builders can contribute to eutrophication problems. As an alternative, numerous proposals have been made, mainly organic materials as wash-active builders instead of the condensed ones

To use phosphates, but most of these materials tend to be unsatisfactory for one reason or another, e.g. are they less effective or biologically unacceptable, or simply too expensive.

It has also been proposed to alleviate the eutrophication problems by using smaller amounts of condensed phosphate builders in the presence or absence of other detergent builders, but few of these suggestions have been accepted in practice. Thus, if smaller amounts of sodium tripolyphosphate are used without additional builders, considerable problems can arise if the agents are used in hard water and there is not enough phosphate to trap all calcium ions present. This leads to the precipitation of insoluble calcium phosphates, which can be deposited on the washed textiles, apart from reduced washing performance due to inadequate softening of the water, sometimes accompanied by the separation of insoluble calcium salts of anionic detergent compounds.

On the other hand, if a condensed phosphate builder is used with any phosphate-free builders, the former can prevent the latter from working effectively, especially in the case of other builders that are calcium salt-precipitating, e.g. Sodium. Furthermore, there are relatively few other wash-active builders that are completely acceptable to the environment and good enough to be used, even with the partial replacement of a condensed phosphate builder.

In recent years, a great deal of effort and expense has been put into solving these problems,

for which numerous new materials were synthesized and evaluated. However, it would inevitably take several years to educate a completely new material for household use, and therefore interest has recently focused on known low-phosphate and non-phosphate materials that act as builders through either sequestration, precipitation or ion exchange, and of which is certain that they offer security for the environment.

It has now been found that it is possible to achieve effective washing properties with reduced phosphate builder contents by using a partially neutralized alkali metal orthophosphate in combination with a carbonate of an alkali metal in fixed proportions. Since both of these materials are well known as such, there are no environmental safety issues, provided that the agents do not produce too alkaline solutions when used. Furthermore, although both essential wash-active builder materials are so-called precipitating builders, i.e., inactivate the calcium hardness ions by forming insoluble calcium salts, the precipitate on clothing can be prevented from depositing in unacceptably high amounts.

The particulate alkaline detergent containing an alkali metal hydrogen orthophosphate, a carbonate, bicarbonate or sesquicarbonate of an alkali metal and a surfactant according to the invention is characterized in the preceding patent claim 1.

GB-PS 1 412 401 describes the production of detergents with 5 to 15% orthophosphates and 20 to 45% by weight alkaline salts, e.g. Sodium carbonate, suggested to give a pH of at least 9.2 when used. These agents were of particularly low phosphate content and were also intended for use at low product concentrations. However, it turned out that such phosphate levels were unnecessarily low for adaptation to the currently expected legislation,

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which should come into force in different countries. In addition, at higher product concentrations, as are commonly used in many European countries, the compositions of GB-PS 1 412 401 were less effective than desired, compared to other phosphate-rich agents based on sodium tripolyphosphate alone as a detergent builder. This invention provides higher, i.e. Phosphate content above 15%, which has more effective wash-active builder properties.

The Al-potassium metal orthophosphate used in the detergent according to the invention can be either a potassium or a sodium hydrogen orthophosphate, the latter being preferred since it is cheaper and more readily available. Part or all of the disodium monohydrogen orthophosphate is preferably used in the preparation of the compositions, although part can be neutralized to the trialkali metal salt during powder processing, or part of the latter may be present from the beginning, provided the pH is not too high. On the other hand, the mono- or mixed mono- and dialkali metal orthophosphate can, if desired, be used to prepare the compositions. If too much monosodium dihydrogen salt is used, the pH value can drop considerably, in which case more alkaline material must also be added.

It can be advantageous to use a mixture of disodium and monosodium hydrogen orthophosphates in a molar ratio of about 1: 3 to 2: 3, in particular about 1: 2, as the source of the alkali metal hydrogen orthophosphates, since such a mixture is commercially available stands because it is produced as a raw material in the manufacture of sodium tripolyphosphate, where it is known as an "oven feed material". This leads to valuable cost savings because it saves energy that would otherwise be used to convert the furnace feed material into sodium tripolyphosphate.

The alkali metal hydrogen orthophosphate used in the manufacture of the detergent may be in the form of anhydrous or water-containing salts, e.g. as disodium monohydrogen orthophosphate dodecahydrate. Of course, hydration or dewatering can also take place during detergent processing; however, the amounts of the alkali metal hydrogen orthophosphates are calculated in anhydrous form.

An alkali metal hydrogen orthophosphate content of about 20 to 30% by weight is particularly preferred, i.e. the phosphorus content in the agents is about 4 to 5%. These phosphorus levels are significantly lower than usual when sodium tripolyphosphate is used as a builder, i.e. at levels that, until recently, were generally over 30% of the budget.

If higher levels of alkali metal hydrogen orthophosphates are used, in particular in the range from 30 to 50% by weight, the compositions are particularly useful as so-called soaking / prewashing agents if they are used in relatively low product concentrations in order to remove the dirt before the normal washing process to support. They can also be used as conventional textile detergents themselves, where the water hardness is high and phosphate eutrophication problems do not arise. The use of the alkali metal hydrogen orthophosphates prevents excessively high alkalinity, especially at higher levels of alkali metal hydrogen orthophosphate.

The alkali metal carbonate used is a potassium or sodium carbonate, the latter being preferred, or a mixture of these carbonates. The carbonates are preferably the completely neutralized compounds, but they can also contain some potassium or sodium bicarbonate or sesquicarbonate.

Although the amount of carbonate, bicarbonate or sesquicarbonate of an alkali metal can be varied between 20 and 50% by weight, an amount of 20 to 45% by weight is preferably used, depending on the type of detergent to be produced. Lower levels of alkali metal carbonates, bicarbonates or sesquicarbonates in the range above 20 to 30% by weight are normally used when higher levels of alkali metal hydrogen orthophosphates are used. The amount of alkali metal carbonate, bicarbonate or sesquicarbonate is determined on an anhydrous basis, although these can be hydrated before or during incorporation into the detergent.

The detergents according to the invention necessarily contain 5 to 40, preferably not more than about 25, e.g. about 10 to about 20 percent by weight of a synthetic anionic, nonionic, amphoteric or zwitterionic detergent surfactant or a mixture thereof. A nonionic detergent surfactant is particularly preferably used either alone or in a mixture with other anionic detergent surfactants in the case of low-foaming agents. Many suitable surfactants are commercially available and are extensively described in the literature, e.g. in Schwartz, Perry & Berch, "Surface Active Agents and Detergents", Volumes I and II.

The preferred non-ionic surfactants that can be used are e.g. in particular the reaction products of compounds with a hydrophobic group and a reactive hydrogen atom, e.g. aliphatic alcohols, acids, amides or alkylphenols with alkylene oxides, especially ethylene oxide, either alone or with propylene oxide. Special non-ionic detersive surfactants are alkyl (C6-C22) phenol / ethylene oxide condensates, generally 5 to 25 ÄO, i.e. 5 to 25 units of ethylene oxide per molecule; the condensation products (C6-C18) aliphatic primary or secondary, linear or branched alcohols with ethylene oxide, generally 6 to 30 ÅO, and condensation products of ethylene oxide with the reaction products of propylene oxide and ethylenediamine.

Other so-called non-ionic detergent surfactants are e.g. long chain tertiary amine oxides, long chain tertiary phosphine oxides and dialkyl sulfoxides. Mixtures of amine oxides with ethoxylated non-ionic compounds can also be used.

The anionic detergent surfactants that can be used are usually water-soluble alkali metal salts of organic sulfates and sulfonates with alkyl groups of about 8 to 22 carbon atoms, the term alkyl including the alkyl portion of higher acyl groups. Examples of suitable synthetic anionic detergent surfactants are sodium and potassium alkyl sulfates, especially those obtained by sulfating higher (C8-C18) alcohols, e.g. from tallow or coconut oil; Sodium and potassium alkyl (C8-C20) benzenesulfonates, especially sodium lin.-sec .-- alkyl (C10-C15) benzenesulfonates; Sodium alkyl glyceryl ether sulfates, in particular those ethers of the higher alcohols which are derived from tallow or coconut oil, and synthetic alcohols derived from petroleum; Sodium coconut oil fatty acid monoglyceride sulfates and sulfonates; Sodium and potassium salts of sulfuric acid esters of higher (C8-C18) fatty alcohol / alkylene oxide, especially ethylene oxide reaction products; the reaction products of fatty acids, such as coconut fatty acids, esterified with isethionic acid and neutralized with sodium hydroxide; Sodium and potassium salts of fatty acid amides of methyl taurine; Alkane monosulfates, such as those resulting from the reaction of α-olefins (C8-C20)

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Sodium bisulfite and those derived from the reaction of paraffins with S02 and Cl2 and subsequent hydrolysis with a base to produce a statistical sulfonate; and olefin sulfonates, an expression used to describe the material from the reaction of olefins, in particular CB-C20-a-olefins, with SO 3 and subsequent neutralization and hydrolysis of the reaction product. The preferred anionic detergent surfactants are sodium (C10-C15) alkylbenzenesulfonates and sodium (C12-C1S!) Alkylsulfates.

Amphoteric or zwitterionic detergent surfactants can also be used in the agents according to the invention, but this is normally not desirable because of their relatively high costs. If amphoteric or zwitterionic detergent surfactants are used, this is generally done in small amounts in means based on the customary synthetic anionic and / or non-ionic detergent surfactants.

Some soaps can also be used in the agents according to the invention, but not as the only detergent surfactant. Soap is particularly useful at low levels of binary and ternary mixtures along with nonionic or mixed synthetic anionic and nonionic detergent surfactants that have low foaming properties. Soaps used are the sodium, or less desirably potassium salts of C10-C24 fatty acids. The soaps are particularly preferably predominantly based on the longer chain fatty acids within this range, i.e. at least half of the soap has a carbon chain length of 16 or more. The most convenient way to do this is to use soaps from natural sources, such as tallow, palm, or rapeseed oil, which can be cured if desired, along with smaller amounts of other, shorter-chain soaps made from nut oils, such as coconut oil or palm kernel oil . The amount of such soaps can vary between about 0.5 and about 25 percent by weight, with smaller amounts of about 0.5 to about 5% generally being sufficient for foam control. Amounts of soap between about 2 and about 20%, in particular between about 5 and about 15%, are preferably used in order to have an advantageous effect on the washing performance.

Apart from the detergent surfactants and detergent builders, the detergents according to the invention can contain any of the conventional additives in the amounts in which such materials are normally used in textile detergents. Examples of these additives are, for example, foam boosters, such as alkanolamides, in particular the monoethanolamides, which are derived from palm kernel fatty acids and coconut fatty acids, foam suppressants, such as alkyl phosphates, waxes and silicones, agents which counteract dirt redeposition, such as sodium carboxymethyl cellulose and polyvinylpyrrolidone, oxygen-based bleaching agents and sodium percarbonate , Peracid bleach precursors, chlorine-releasing bleaches, such as trichloroisocyanuric acid and alkali metal salts of dichloroisocyanuric acid, fabric softener. inorganic salts such as sodium sulfate and magnesium silicate and, usually in very small amounts, fluorescent agents, perfumes, enzymes such as proteases and amylases, germicides and colorants.

An amount of sodium percarbonate, preferably between about 10 and about 40%, e.g. about 15 to about 30%, based on the weight of the agents, incorporated. It has been shown that the effect of sodium percarbonate is increased in these agents. Moreover, when the sodium percarbonate has released oxygen when used, the remaining sodium carbonate can contribute to the alkalinity reserve of the wash solution.

It is also desirable to incorporate one or more agents which counteract the separation of dirt in the detergents according to the invention in order to reduce the tendency to form inorganic deposits on washed textiles. The most effective agents of this type are anionic polyelectrolysis, in particular polymeric aliphatic carboxylates, which appear to stabilize the suspensions of insoluble calcium salts and thereby prevent their deposition on textiles. The amount of such anti-redeposition agents is normally between about 0.05 and about 5 percent by weight, preferably between about 0.1 and about 2 percent by weight of the agents.

Specific preferred agents against redeposition are the alkali metal or ammonium, preferably sodium salts of homo- and copolymers of acrylic acid or substituted acrylic acids, such as sodium polyacrylate, the sodium salt of copolymethacrylamide / acrylic acid and sodium poly-a-hydroxyacrylate, salts of copolymers of maleic anhydride with ethylene, vinyl methyl ether or styrene, in particular 1: 1 copolymers, and optionally with partial esterification of the carboxyl groups. Such copolymers generally have molecular weights in the range of about 2,000 to 500,000. Other agents which counteract the deposition are e.g. the sodium salts of polymaleic acid, polyitaconic acid and poly-aspartic acid, phosphate esters of ethoxylated aliphatic alcohols, polyethylene glycol phosphate esters and certain phosphonates, such as sodium ethane-l-hydroxy-l, l-diphosphonate, sodium ethylenediaminetetramethylene phosphonate and sodium - 2-phosphonate. Mixtures of organic phosphonic acids or substituted acrylic acids or their salts with protective colloids, such as gelatin, described in Dutch patent application 7 692 082 can also be used. The most preferred anti-redeposition agent is sodium polyacrylate with a molecular weight of about 10,000 to 50,000, e.g. about 20,000 to 30,000.

Small amounts of other phosphate- or phosphate-free detergent builders can also be incorporated into the detergents according to the invention, the latter being either the so-called precipitating builders, sequestering agents or ion exchange builders. Small amounts of alkali metal tripolyphosphate or pyrophosphate may be present as contaminants with the alkali metal orthophosphate, e.g. in amounts up to about 5 percent by weight, but they are preferably not present in the compositions. The presence of other phosphate-free detergent builders can be advantageous if the washing power is to be increased while using relatively small amounts of alkali metal orthophosphate and without using excessive amounts of alkali metal carbonate, because of the high alkalinity which would otherwise result. Examples of such other detergent builders that could be used under these circumstances are amine carboxylates such as sodium nitrilotriacetate and sodium aluminosilicate ion exchange materials, e.g. Zeolite A and X. However, such other detergent builder materials are not necessary, and it is a particular advantage of the agents according to the invention that satisfactory detergency properties can be achieved with the mixture of the alkali metal orthophosphate and alkali metal carbonate builder salts at lower phosphate contents than they were previously considered necessary without other phosphate-free builders.

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In general, it is also desirable to incorporate an amount of an alkali metal silicate, especially sodium ortho, meta or preferably neutral or alkaline silicate into the detergents. The more alkaline orthosilicate and meta-silicates are normally only used in smaller quantities, in a mixture with the neutral or alkaline silicates. The presence of such alkali metal silicates, usually in amounts of from about 5 to about 15 percent by weight of the compositions, is advantageous for reducing corrosion of metal parts in washing machines, apart from the fact that this leads to working advantages and generally improved powder properties. The presence of the alkali metal silicates in the compositions according to the invention can contribute to increased inorganic deposits on washed textiles, and therefore only small amounts, if any, of such silicates are preferably used, for example not more than about 10 percent by weight of the compositions.

The agents according to the invention must be alkaline, but not too strongly alkaline, since this could be harmful for textiles and also dangerous for use in the household. In practice, the agents should result in a pH of 9 to 11 when used in an aqueous washing solution. In particular for household products, at least a pH of at least about 9.25 and in particular that of about 9.5 or above should preferably arise, since lower pH values are slightly less effective for optimum washing power, a maximum of about 10 , 5th The pH should be measured at the lowest normal use concentration of 0.1 w / v% of the product in water of 12 ° H (Ca) (permanent French hardness, only calcium) at 50 ° C, so that a satisfactory Alkalinity is guaranteed when used at all normal product concentrations. The pH of the detergents in use is controlled by the amount and type of the partially neutralized alkali metal orthophosphate and the alkali metal carbonate used, as well as the other alkali salts which may be present, such as alkali metal silicate and sodium perborate or sodium percarbonate. Because of the high alkalinity of the agents according to the invention, the other constituents of the agents should of course be chosen with regard to their alkali stability, in particular pH-sensitive materials, such as enzymes.

The detergents according to the invention are said to be in particulate form, including powders and granules, and they can be prepared by conventional techniques, e.g. by granulating or by making a slurry and spray drying processes. Dry mixing of the ingredients can also be used, particularly for products to be sold in individual dose packs, such as sachets, but this is not recommended for products sold in bulk to consumers for dispensing in use due to possible separation problems and less uniformity Appearance of the products. If the detergents are produced in the presence of moisture, the components can react with one another, e.g. the partially neutralized alkali metal orthophosphates can be further neutralized by other more alkaline components present.

The invention is further illustrated by the following examples, in which parts and percentages are by weight, the amounts of the ingredients are expressed on an anhydrous basis unless otherwise stated.

Examples 1 and 2

A special detergent was produced using the slurry process and spray drying to the following nominal composition:

Component: %

C12-C15 alcohol - 8 ÄO1 10.0

Disodium orthophosphate 20.0

Sodium carbonate 35.0

Sodium percarbonate2 25.0

Sodium carboxymethyl cellulose 1.5

Sodium polyacrylate 1.0

Sodium alkyl phosphate 0.5

Fluorescent agent 0.5 water to 100.0

1 4% of the non-ionic detergent surfactant was incorporated into the spray-dried powder, the remaining 6% sprayed onto the end product.

2 Added after spray drying.

This agent (Example 1) was tested at a product concentration of 0.4% in water of 25 ° H (Ca - "-: Mg4" 1-; 4: 1) at 95 ° C for washing performance and was found to be a commercially available product equivalent to 34% sodium tripolyphosphate. The powder was also checked for inorganic deposition after several washing cycles. The latter tests were also carried out in an automatic (rotating drum) washing machine at a product concentration of 0.6% in 35 ° H water (Ca ++: Mg "; 4: 1) at 95 ° C using naturally soiled laundry load with test substances Results after 10 wash cycles showed an inorganic deposition content of 1.8%, which was favorable compared to the (2.2%) for a commercially available sodium tripolyphosphate comparison product 4.9%, which is still a clear advantage for the agent according to the invention, in spite of the high content of separating builder salts. The same test substances were also tested for dirt redeposition from the naturally soiled substances by changing the light reflection after 10 and 20 wash cycles were measured, and it was found that the product of the invention resulted in significantly less redeposition than the commercially available comparative test product.

A further powder (Example 2) was produced with a similar composition, but the content of nonionic surfactant was reduced from 10 to 4% and 6% sodium alkylbenzenesulfonate was added instead. In addition, 3% sodium tallow soap was added and the amount of sodium percarbonate was reduced accordingly to 22%. This agent also showed good textile washing and bleaching properties despite the low phosphate content.

Both agents were superior to the commercial product made with sodium tripolyphosphate when bleaching test stains stained with tea, the increase in light reflection for Examples 1 and 2 being 6.3 and 8.2 units greater.

Examples 3 and 4

Two agents were prepared by dry blending the ingredients to the same formulation as in Example 1, except that in Examples 3 and 4 the amount of disodium orthophosphate was reduced to 25 and 30% and the amount of sodium carbonate to 30 and 25%, respectively has been. The products were evaluated in a Terg-O-Tometer against the product of Example 1 for their textile washing properties, for which purpose a first control formulation contained 10% of the disodium orthophosphate and 45% of the sodium carbonate, but was otherwise as in Examples 3 and 4 , and a second control formulation of 30% sodium tripolyphosphate

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phat aïs builder with 25% sodium perborate at 4 g per liter in water at 25 ° H at 80-85 ° C. The products of both Examples 3 and 4 showed slightly better washing properties on artificially soiled test substances compared to Example 1, significantly better washing performance than the first control product and significantly improved bleaching properties compared to the second control product.

Examples 5 to 7 The formulations of Examples 3 and 4 were varied by first adding the sodium percarbonate from Example 3 to sodium perborate (Example 5), then the 10% non-ionic surfactant from Example 4 to 6% sodium alkylbenzene sulfonate and 4% of the same non-ionic detergent surfactant (Example 6) and thirdly the 10% non-ionic surfactant of Example 4 against 10% sodium alkylbenzenesulfonate and also the disodium orthophosphate and sodium carbonate contents to 15.5 and 40% (Example 7) were exchanged or modified. The products were evaluated for their washing and bleaching properties in a Terg-O-Tometer and again showed good results. However, the use of the perborate in Example 5 offered just less advantageous bleaching action on the test fabric and the lowering of the non-ionic surfactant content in Example 6 gave slightly weaker but still good washing results. The product of Example 7 showed very good washing properties despite the low phosphorus content when evaluated against a similar product with 30% sodium tripolyphosphate as a builder.

Examples 8 to 10 Three products were made to the same recipe as in Examples 1, 3 and 4, respectively, except that the disodium orthophosphate was replaced with furnace feed, i.e. a mixture of disodium and mono-

sodium hydrogen phosphate (ratio about 1: 2). The test evaluation showed that the products of Examples 8 to 10 gave wash solutions with (0.3-0.4 units) lower pH compared to Examples 1, 3 and 4. Apart from 5, there was a directed advantage, but none substantial change in wash performance when using the furnace feed material in place of the disodium orthophosphate.

Examples 11 to 13 A detergent (Example 11) was prepared by dry mixing to the same recipe as Example 1, except that the sodium polyacrylate was omitted. Either 1.0% sodium copoly (1: 1) vinyl methyl ether maleate (in Example 12) or 1.0% 15 sodium polyacrylate (MW • - • 25,000) (in Example 13) was added to this agent. The amount of inorganic deposits on cotton terry cloth was then determined in comparison with a control recipe with 30% sodium tripolyphosphate and 25% sodium perborate with the following results (product-20 dosage 6 g / 1 in 35 ° H water at 80-85 ° C):

example

5 washes

% Deposition 10 washes

20 washes

11

4.2

8.0

10.4

12

1.3

2.0

2.5

13

1.2

2.3

2.6

control

0.6

2.8

3.6

The results show the advantageous results of incorporating a deposition-preventing agent 35 into the products according to the invention.

Claims (10)

640261 1. An alkali metal hydrogen orthophosphate, a carbonai, bicarbonate or sesquicarbonate of an alkali metal and a surfactant-containing, particulate alkaline detergent, characterized in that it contains 15 to 50% by weight of an alkali metal hydrogen orthophosphate, 20 to 50% by weight of a carbonate, bicarbonate or Sesquicarbonates of an alkali metal and 5 to 40 wt .-% of a synthetic surfactant, based on the weight of the total detergent, contains. 2. Detergent according to claim 1, characterized in that the alkali metal hydrogen orthophosphate disodium monohydrogen orthophosphate or a mixture thereof with monosodium dihydrogen orthophosphate, preferably a mixture of disodium and monosodium hydrogen orthophosphate in a molar ratio of 1: 3 to 2: 3, in particular not contains more than 30% by weight of the alkali metal hydrogen orthophosphate, particularly preferably 20 to 25% by weight, or 30 to 50% by weight of the alkali metal hydrogen orthophosphate. 2nd PATENT CLAIMS 3. Detergent according to one of the preceding claims, characterized in that the detergent contains sodium carbonate and / or sodium bicarbonate, preferably in an amount of 20 to 45 or 20 to 30 wt .-%. 4. Detergent according to one of the preceding claims, characterized in that it contains 5 to 25 wt .-% of a non-ionic surfactant. Contains 5 wt .-% alkali metal tripolyphosphate or pyrophosphate. 5. Detergent according to one of the preceding claims, characterized in that it contains 0.5 to 25 wt .-% soap. 6. Detergent according to one of the preceding claims, characterized in that it contains 10 to 40 wt .-% sodium percarbonate. 7. Detergent according to one of the preceding claims, characterized in that it contains no more than 10% by weight of sodium silicate. 8. Detergent according to one of the preceding claims, characterized in that it contains 0.05 to 5% by weight of an agent which counteracts the deposition, preferably a polymeric aliphatic carboxylate, in particular an alkali metal or ammonium salt of a homo- or copolymer of acrylic acid or one substituted acrylic acid. 9. Detergent according to one of the preceding claims, characterized in that it is not more than 10. Use of the detergent according to claim 1 in the form of a 0.1 wt .-% solution, which has a pH between 9.25 and 10.5, for washing textiles.