JPH044359B2 - - Google Patents

Description

[Detailed description of the invention]

FIELD OF THE INVENTION The present invention relates to a method for washing fabrics, and in particular to detergent compositions for washing fabrics. Although not limited,
In particular, the present invention relates to detergent compositions suitable for laundering fabrics in moderately soft water at low temperatures. Detergent compositions usually include detergent active compounds as main ingredients along with detergent builders. Traditional detergent builders are usually inorganic substances, especially condensed phosphates such as sodium tripolyphosphate. However, it has been suggested that eutrophication problems occur when using phosphate-based detergent builders. Detergent builders that have been proposed as alternatives, such as sodium nitrilotriacetate (NTA) and synthetic polyelectrolyte materials, are more expensive and less efficient than phosphate-based detergent builders, and some The product is not satisfactory for these reasons. It is known that sodium carbonate acts as a detergent builder by removing calcium from hard water in the form of precipitated calcium carbonate. but,
Calcium carbonate tends to accumulate on washed fabrics, making them stiffer and less resistant to abrasion. British Patent No. 1491978 (Ciba-Geigy) discloses that a detergent composition containing a phosphate compound as a detergent builder for washing fabrics in relatively hard water can be used to prevent deposits. A group of polymeric materials based on maleic anhydride monomers suitable for use as agents are described. As anti-deposition agents in detergent compositions containing water-soluble carbonate materials as detergent builders, a group of polymeric materials, such as those described in British Patent No. 1,491,978, have the potential to The present inventor has now discovered that it is effective outside the home. Thus, in accordance with the present invention, when washing fabrics in water having calcium hardness, at least (i) from about 5 to about 40% by weight of a synthetic detergent active substance, based on the water, (ii) water-soluble carbonic acid. salt builder substance, about 10 to about
70% by weight and (iii) has an average molecular weight of about 500 to about 3000 and has no groups within its molecular structure. (In the formula, R ₁ is hydrogen or a hydroxy group,
R ₂ is an alkyl group having 1 to 4 carbon atoms or an acetoxy group) to prepare a washing liquid, and the washing liquid contains a saturation ratio of calcium to carbonate of about 50 or less. A method for washing a fabric is provided, the fabric having a pH of about 9.5 to about 11.0. The term "saturation ratio" is well known in the art. For example, AE Nielsen's CEPAS 78, Conference on
Electrolytic Precipitation in Aqueons
Solution，Panum Institute，University of
See Copenhagen (August 16-18, 1978). For any composition, the saturation ratio can be easily calculated from the following equation: In the formula, SR is the saturation ratio, a _Ca is the initial activity of calcium ions, and a _Cp3
is the initial activity of the carbonate ion, and K _SO is the thermodynamic solubility product of calcite. The activities of calcium and carbonate ions vary depending on their concentration and the ionic strength of the solution, which in turn depends on various other components, especially ionic salts that may be present in the wash liquor. Depends on it. Table 1 below shows how the saturation ratio of calcium to carbonate can vary under a large number of possible conditions.

[Table] From the table, it is clear that the factors that reduce the saturation ratio include lowering the temperature and increasing the ionic strength. It is also clear that the saturation ratio decreases when the concentration of carbonate ions is decreased and when the concentration of calcium ions is decreased. The saturation ratio is about 50.0 or less, preferably about 40.0 or less,
It is an essential requirement of the present invention that it is most preferably about 35.0 or less. Therefore, a desirable requirement for the method according to the invention is that the maximum temperature of the wash liquor in contact with the fabric is about 60°C, most preferably a temperature of about 50°C or less. It is also a desirable requirement for the method according to the invention that the amount of detergent composition added to the water to make the wash liquor is less than or equal to about 5 g/ml, most preferably less than or equal to about 4 g/ml. Furthermore, the calcium hardness of the water used to make the washing liquid is approximately 2.0 × 10 ^-3 MCa ions/or less.
Most preferably less than or equal to about 1.5×10 ^-3 is also a desirable requirement for the method according to the invention. However, by using additional sequestering agents in hard water, the saturation ratio can be lowered below the desired value. This is evident from the data below for the trisodium salt of nitrilotriacetic acid. It seems safe to assume that the trisodium salt interacts with calcium based on a 1:1 molar ratio under the conditions described below. Example A in the table shows 2.0g/2.0g/in water of 1.2×10 ^-3 MCa.
shows the conditions found in a laundry solution when using a product containing 31.8% sodium carbonate and 34.1% sodium sulfate at a product concentration of . The table below shows the saturation ratio of the same product in 2.4×10 ^-3 MCa water at 40°C, as well as the SR value when using 5%, 10% and 15% NTA in place of sodium sulfate. is shown.

[Table] The table shows that under conditions of 2.4×10 ^-3 MCa water and moderate carbonate water difference (31.8%), NTA is required to reduce the saturation ratio to below 35; It turns out that an amount of about 10% is sufficient. Higher carbonate levels (eg K, 47.7% carbonate) would require approximately 15% NTA. These requirements can be mutually accommodated. For example, if the water hardness is particularly low, the amount of product applied can be increased, and if the temperature is lower, the amount applied can be increased, even if the water hardness is high. The present invention also provides a detergent composition for washing fabrics, the composition comprising: (i) from about 5 to about 40% by weight of a synthetic detergent active; (ii) from about 10 to about 70% by weight of a water-soluble carbonate material; % by weight, and (iii) has an average molecular weight of about 500 to about 3000 and contains groups within its molecular structure. (wherein R ₁ is hydrogen or a hydroxyl group, and R ₂ is an alkyl or alkoxy group having 1 to 4 carbon atoms, a carboxylic acid group or an acetoxy group) from about 0.5 to about 5% by weight. and has calcium hardness at a calcium ion level of 1.2 x 10 ^-3 M, when the composition is added at a dosage of 1 g per 1 g at a temperature of 20°C, the composition has a calcium hardness of about 50 or less. saturation ratio of calcium to carbonate and a pH of about 9.5 to about 11.0
A detergent composition characterized in that it provides the following is provided. The detergent active compounds used in the compositions of the invention may be any of the conventional anionic, nonionic, amphoteric or zwitterionic detergent active compounds or mixtures thereof, but during use It is desirable that an excessive amount of water-insoluble calcium salt not be formed in hard water. A large number of detergent active compounds of this type are commercially available, and for example, "Surface Active Agents" by Schwartz, Perry and Berch.
Detergents and Detergents)” Volume 1. Suitable detergent-active compounds preferably used include non-ionic detergent-active compounds, which naturally cannot form calcium salts, and anionic detergent-active compounds, such as ether sulfates, which form water-soluble calcium salts. , or anionic detergent-active compounds which form insoluble calcium salts when used alone, but in combination with additional solubilizer compounds, especially other detergent-active compounds, such as alkylbenzene sulfones. Mixtures of sodium acid and nonionic detergent active compounds and certain mixed olefin sulfonates are included in which some of the olefin sulfonate acts as a solubilizer for other less soluble components. Particular nonionic detergent active compounds that may be used in the compositions of the invention include _C10 to _C18 , preferably _C10
~ _C15 alkyl group and about 5 per molecule
an ethoxylated fatty alcohol, preferably a linear monohydric alcohol, having ~15, preferably 7 to 12 ethylene oxide (EO) units, and
having C8 _{- C16} , preferably _C8 - _C9 alkyl groups;
and ethoxylated alkylphenols having about 4 to 12 EO units per molecule.
Non-ionic compounds can often be used in combination with small proportions of other detergent-active compounds, especially anionic compounds, to improve the foaming properties and powder properties. Good results are also obtained with mixtures of nonionic compounds and amine oxides. Preferred anionic detergent active compounds forming soluble or only slightly insoluble calcium salts are alkyl (C ₁₀ -
_C20 ) Sulfates and alkyl ethers (1~
20EO) Olefin sulfate detergent active compounds obtained by neutralizing and hydrolyzing sulfates, especially those containing C ₁₀ -C ₁₅ alkyl groups and 1-7 EO, as well as the products of sulfonation of olefins. The raw material olefin can be prepared, for example, by the "cracked-wax" method or by the "Zeigler" method.
Linear C ₁₂ -C ₂₀ α-olefins, especially C ₁₄ -C ₁₆ α-olefins, prepared by the (Zeigler) process are preferred, but also local internal random olefins, commonly known as vinylidene olefins, are used. be able to. The anionic detergent-active compounds are used in the form of alkali metal, ammonium or substituted ammonium salts, preferably sodium salts. Other detergent active compounds that do not form insoluble calcium salts but are of lesser commercial interest include α-sulfonated (C ₁₀ -C ₂₀ ) fatty acids and C ₁
Salts of esters with ~ _C10 , preferably _C1 - _C3 alcohols, 2-acyloxyalkane-1-sulfonic acids, especially about 10 to 20, preferably in the alkyl group.
salts containing 12 to 16 carbon atoms and containing 1 to 8 carbon atoms in the ester-forming group;
Trialkylamine oxides having one _C10 - _C22 alkyl group and two _C1 - _C4 alkyl groups or _C2 - _C3 hydroxyalkyl groups, as well as _C10 - _C22
Included are dialkyl sulfoxides having an alkyl group and a _C1 - _C4 alkyl or _C2 - _C3 hydroxyalkyl group as well as detergent-active betaines and sulfobetaines. As already mentioned, particularly good results are obtained with mixtures of several detergent-active compounds.
In particular, alkylbenzene sulfonates (which when used alone form insoluble calcium salts) are combined with certain solubilizer compounds in small proportions, such as nonionic alkyl sulfates or alkyl ether sulfates. When used in conjunction with other detergent active compounds, good cleaning performance is obtained and it is also relatively economical. The weight ratio of such solubilizer compounds to alkylbenzene sulfonates is preferably from 1:1 to 1:10, in particular from 1:2 to 1:8. Also, although it is generally undesirable for the detergent active to be entirely soap, soap can also be included together with other detergent active compounds, for example as a binary or ternary mixture. The total amount of detergent active compounds is in the range from 5 to 40%, preferably from 5 to 30%, relative to the weight of the composition. Suitable amounts of detergent active compounds usually exceed 8% by weight. The water-soluble carbonate material used as the raw material is preferably an alkali metal carbonate, such as sodium or potassium carbonate, or a mixture thereof, from the viewpoint of cost and efficiency. The carbonate may be completely neutralized or partially neutralized; for example, sesquicarbonate may be substituted for a portion of the carbonate. The amount of alkali metal carbonate in the detergent composition can vary over a wide range, but is about 10% or more, preferably about 20% by weight.
Above, it is particularly preferably 35 to 65%. The amount of carbonate-based detergent builder can be increased to near about 70%, but room must be left for the inclusion of anti-deposition agents and detergent active compounds. Within this range, concentrations near the upper end are required for laundering under conditions of low product concentrations typically experienced in North America, and concentrations near the lower end apply to laundering at high product concentrations found in Europe. It is something. Furthermore, in order to reduce the risk of medical damage caused by accidental swallowing, it is desirable to keep the carbonate content as low as possible. Polymeric anti-deposition agents are polycarboxylate materials. One group of polycarboxylate materials that have been found to be useful in the compositions of the present invention are of the formula (In the formula, R ₁ is H or OH, and R ₂ is -COOH
It consists of a homopolymer having a repeating unit represented by Polycarboxylates belonging to this group include polyacrylic acid, polymethacrylic acid, polyitaconic acid, polymaleic acid and polyhydroxyacrylic acid, and the hydrolysis products of the corresponding polymeric acid anhydrides. Polymeric maleic anhydride is essentially a homopolymer of maleic anhydride and hydrolyzes very easily, for example when heated with water, to form free carboxylic acid groups on the carbon backbone and perhaps some This results in a polymeric product containing residual acid anhydride groups. This product is not pure polymaleic acid. Since the actual structure of the product is unknown, this type of polymer product produced by hydrolyzing polymaleic anhydride will be referred to herein as "hydrolyzed polymaleic anhydride." The second group of polycarboxylate materials consists of copolymers of maleic acid and olefinic monomers such as ethylene or vinyl methyl ether. The ratio of maleic acid units to other monomers is preferably in the range of 1:1 to 3:1. The polycarboxylate substance is preferably used in the form of an alkali metal salt, especially a sodium salt.
And the amount of these polycarboxylate materials used in the composition of the invention is from 0.5 to 5% of the weight of the composition, calculated as sodium salt;
And most preferably 1.0-3.0%. The present inventor has confirmed that a significant effect is observed when a polymeric substance, which is an anti-sediment agent, is present in a solution at a concentration of about 20 ppm to about 50 ppm, and the usual amount used in detergent products is about 1/1 solution. ~ Since it is about 4g,
The amount of polymeric substances in detergent products should be at least 0.5%, and there is no benefit to using more than 5%. Also, since polymeric substances are more expensive than other ingredients in detergent products, addition of high proportions that do not lead to improved effectiveness should be avoided as much as possible. These materials may also be hydrolyzed copolymers of maleic anhydride and ethylenically unsaturated comonomers. Ethylenically unsaturated monomers used for copolymerization with maleic anhydride can be used for a wide range of substances,
For example, acrylic acid, methacrylic acid, crotonic acid, itaconic acid or its anhydride, aconitic acid, and esters thereof, such as ethyl acrylate and methacrylate, acrylonitrile, acrylamide, vinyl acetate, styrene, α
- Can be chosen from methylstyrene, methylvinylketone, acrolein, ethylene, propylene or mixtures thereof. The polymer obtained when using a mixture of monomers can be, for example, a terpolymer derived from maleic anhydride and two other monomers consisting of vinyl acetate and ethyl acrylate. Particularly preferred copolymers are those derived from acrylic acid, its amides and esters, methacrylic acid, its amides and esters, and hydrolyzed copolymers of vinyl esters and maleic anhydride. Further information on these polymers and methods of their manufacture can be found in British Patent No. 1369429, incorporated by reference.
It is disclosed in the specifications of No. 1411063, No. 1414918, and No. 1491978. Although it is not essential to include a calcium ion sequestering agent in the composition of the present invention, when the calcium ion sequestering agent is used in an amount of 0.1% based on the weight of the solution, 1.2×10 ^-3 M The concentration of free calcium ions in a solution containing calcium ions is approximately 2.0×
The composition can further include about 5 to 20% by weight of a calcium ion sequestering agent having sufficient calcium ion sequestering capacity to reduce the concentration to 10 ^-4 M or less. The amount of calcium ions in an aqueous solution is determined by a special calcium electrode that creates an electric potential across a thin layer of water-inert ion-exchange liquid held tightly by an inert porous membrane disc. It can be measured using This liquid is a calcium salt of an organophosphoric acid which exhibits a very high degree of specificity towards calcium ions. When the internal solution containing calcium chloride contacts the internal surface of the diaphragm disk, a stable potential difference is created between the internal reference electrode and the ion exchange liquid layer. In use, the calcium special electrode is immersed in a solution containing 1.2 x 10 ^-3 M calcium ions and incrementally added to the solution of the sequestering agent to be tested for 1 hour at 25°C. Add to. The resulting potential is measured and the concentration of calcium ions in the presence of 0.1% of the test sequestrant is determined in relation to the potential with the standard solution. A large number of suitable sequestering agents are known and commercially available. Examples of suitable sequestering agents include U.S. Pat.
Water-soluble salts and ether bonds of aliphatic hydroxypolycarboxylic acids, such as citric acid, cycloaliphatic and aromatic polycarboxylic acids, such as cyclopentanetetracarboxylic acid and mellitic acid, as described in No. 4146495. and polyacetal carboxylates, as well as homologs and analogs of these compounds, as well as sodium nitrilotriacetate. Mixtures of two or more of these suitable sequestering agents may be used if desired, for example because of supply or biological issues. These compounds are commonly used in the form of salts that are soluble or dispersible in water, especially alkali metal salts such as sodium, or ammonium or substituted ammonium salts, but they can also be used in acid form and neutralized in solution. It will be understood that this is possible. As sequestering agent it is convenient to use sodium citrate, which is commercially available and biologically acceptable. The amount of sequestering agent used should be 5 to 20%, preferably about 10 to about 20%, based on the weight of the composition. The maximum amount of the metal ion sequestering agent is determined by taking into account the actual use, such as relative price with other ingredients. Most desirable are those containing sequestering agents at levels below the content of water-soluble carbonate materials. In addition to the essential carbonate compounds and anti-deposition agents, small proportions of other detergent builders (i.e., at levels below the content of water-soluble carbonate materials) may be included, but not within the composition. The total amount of detergent builder should not exceed about 85% by weight so that there is room for other essential ingredients. One such optional ingredient that has effect as a detergent builder is an alkali metal silicate, particularly a sodium silicate such as alkaline or sodium metasilicate. Low levels of silicates, such as from about 5 to about 10% by weight, are advantageous in reducing the corrosive effects of metal parts in the washing machine, and also provide process benefits and improve the pH of the wash solution at the desired product concentration. Approximately
9.5 to 11.0, preferably about 10.0 to 10.6. If high levels of silicates are used, cleaning power is improved and the alkali metal carbonate content can be reduced slightly. Other detergent builders that may be included in small proportions include:
Particularly included are so-called precipitant builders which form insoluble calcium salts, such as the sodium salts of long-chain alpha-sulfonated monocarboxylic acids and alkyl and alkenyl succinic acids and sodium malonates, as well as analogous compounds. It will be appreciated that some of these materials contain phosphorus, and some may contain low levels of phosphorus or may reduce the value of detergent compositions that are intended to be phosphorus-free. Ion exchange detergent builders such as the various sodium aluminosilicates disclosed in the literature may also be included. In addition to the detergent active compounds and detergent builders, the detergent compositions according to the invention can contain additives of conventional fabric laundry detergent compositions, the amounts of which are such that they are added to the fabric laundry detergent composition. Same amount as normally used. Examples of these additives include foam boosters, such as alkanolamides, especially ethanolamides derived from palm kernel fatty acids and coconut fatty acids, foam suppressants, anti-redeposition agents, such as sodium carboxymethylcellulose, oxygen releasing agents, etc. bleaching agents such as sodium perborate and sodium percarbonate, peracid bleach precursors, chlorine-releasing bleaches such as trichloroisocyanuric acid, inorganic salts such as sodium sulfate, as well as fluorescent agents, usually in very small proportions; Included are fragrances, enzymes, fungicides and colorants. The detergent composition of the present invention can be manufactured by any method commonly used for manufacturing detergent compositions for fabric laundry, such as slurry manufacturing methods and spray drying methods. In the case of spray drying, unless bleach is included, the entire formulation is usually sprayed dry. The compositions can also be manufactured in any of the physical forms commonly found in fabric laundry detergent compositions, including powder, granules, solids, and liquids. The present invention will be explained below with reference to Examples, but these Examples are not intended to limit the present invention. In the examples, all parts and percentages are by weight unless otherwise specified. The percentages of ingredients shown in the examples are converted values based on the use of anhydride. In practice, commonly available hydrates were used, and the water of crystallization of these substances is shown together with other water contained in the composition. Examples 1-3 Detergent compositions were prepared according to the table below. Each composition was used to launder cotton poplin fabrics under specified conditions in a Tergotomer apparatus. After 15 washes, the percentage of inorganic matter deposited on the fabric was determined by burning the fabric and the “Ash%
(15)” is shown in the table.

【table】

Table of Contents Examples 1 and 2 show that compared to the same composition without polymer, compositions containing polymeric materials according to the invention deposit less minerals on the fabric. Examples 4-6 For comparison, the procedure of Examples 1-3 was repeated under conditions of increased saturation ratio. The compositions used, conditions and results obtained are shown in the table below.

Table: Examples 4, 5 and 6 show that at higher saturation ratios, compositions containing polymeric materials according to the invention deposit more minerals on the fabric than those without polymers. It shows. Examples 7 and 8 Examples 7 and 8 are the results of experiments carried out in a washing machine (Kenmore machine manufactured in the United States). The compositions used, conditions and results are shown in the table below.

【table】

Table of Contents Examples 7 and 8 demonstrate that when a composition includes a low molecular weight polymer in accordance with the present invention, the amount of ash is reduced compared to one without the polymer.

Claims (1)

Claims: 1. A method of washing fabrics in water having calcium hardness, comprising: at least (i) about 5 to about 40% by weight of a synthetic detergent active; (ii) a water-soluble carbonate; About 10 to about 70 builder substances
% by weight, and (iii) has an average molecular weight of about 500 to about 3000 and has groups within its molecular structure. (wherein R ₁ is hydrogen or a hydroxy group; R ₂ is an alkyl or alkoxy group having 1 to 4 carbon atoms, a carboxylic acid group, or an acetoxy group). to form a laundry liquor, the laundry liquor having a saturation ratio of calcium to carbonate of no more than about 50 and a pH of about 9.5 to about 11.0; contacting the laundry liquor with the fabric; A method comprising substantially separating from a washing liquid. 2 The polymeric substance has the formula (In the formula, R ₁ is H or OH, and R ₂ is -
2. The method of claim 1, wherein the polymer has repeating units of COOH. 3 The polymeric substance is ethylene, propylene, vinyl methyl ether, acrylic acid, methacrylic acid, crotonic acid, itaconic acid or its anhydride,
A copolymer of at least one comonomer selected from aconitic acid, esters of the aforementioned acids, acrylonitrile, acrylamide, methacrylamide, vinyl acetate, styrene, α-methylstyrene, methyl vinyl ketone, and acrolein, and maleic acid or hydrolyzed maleic anhydride. The method according to claim 1. 4. The method of claim 1, wherein the maximum temperature of the washing liquid in contact with the fabric is about 60°C. 5.Claims 1 and 2 of the claims to prepare a laundry liquid by adding a detergent composition in an application amount of at most 5g per unit.
or the method of Section 3. 6. The method of claim 1, 2 or 3, wherein the water content is high and has a calcium hardness at a level of 2.0 x 10 ^-3 M calcium ions/. 7. The method of claim 1, 2 or 3, wherein a calcium ion sequestering agent is further added to the water. 8 (i) from about 5 to about 40% by weight of a synthetic detergent active; (ii) from about 10 to about a water-soluble carbonate builder substance;
70% by weight, and (iii) has an average molecular weight of 500 to 3000 and contains groups within its molecular structure. (wherein R ₁ is hydrogen or a hydroxyl group, and R ₂ is an alkyl or alkoxy group having 1 to 4 carbon atoms, a carboxylic acid group or an acetoxy group) from about 0.5 to about 5% by weight. A detergent composition containing 1.2×10 ^-3 M
When added at a temperature of 20°C at an application rate of 1 g of the composition to water containing calcium hardness with a calcium ion concentration of detergent composition. 9 The polymeric substance is the formula (In the formula, R ₁ is H or OH, and R ₂ is -
The detergent composition of claim 1, which is a homopolymer having repeating units of COOH. 10 The polymeric substance is ethylene, propylene,
vinyl methyl ether, acrylic acid, methacrylic acid, crotonic acid, itaconic acid or its anhydride, aconitic acid, esters of said acids, acrylonitrile, acrylamide, methacrylamide, vinyl acetate, styrene, α-methylstyrene, methylvinyl ketone and The detergent composition according to claim 8, which is a copolymer of at least one comonomer selected from acrolein and maleic acid or hydrolyzed maleic anhydride. 11. The detergent composition according to any one of claims 8 to 10, further containing 5% to 20% of a calcium ion sequestering agent.