CN1061996A - The liquid detergent composition that contains the suspension peroxygen bleach - Google Patents

Abstract

Liquid detergent compositions are disclosed. The composition contains suspended solid in a liquid phase (containing water and at least one water-miscible solvent) volumetric peroxides and low levels of silicates, which provide solid Desirable suspension of peroxygen compounds in the liquid phase.

Description

The present invention relates to liquid detergent compositions containing suspended solid peroxygen compounds and low levels of silicates.

In response to the long-standing need for aqueous bleach-containing detergent compositions, European Patent Applications 293040 and 294904 describe aqueous detergent compositions having a pH greater than 8, containing anionic surfactants (conventional amounts) and solid peroxygen bleaching agents . The solid peroxygen bleach is suspended in a specific water/solvent medium which has been found to provide the desired chemical stability to the composition.

In these compositions, however, special attention must be paid to the physical stability of the suspended particles in the liquid medium.

One option is represented by, for example, pending UK patent application No. 8926620.9, which describes liquid detergent compositions in which solid particles, especially peroxygen compound particles, are aided by a structured surfactant phase ( surfactant "neat phase") suspended. However, this requires a suspending system which involves easier handling than structured surfactants.

Although not for the purpose of suspending peroxygen bleach particles, structured surfactant phases are described in various patent documents; notably EP-A-79646, EP-A-86614, EP-A-203660 and EP-A- A-295021 describes liquid detergent compositions containing suspended builder particles in which one or more "salting out" electrolytes or "surfactant solubilizing" electrolytes are used to form a structured phase containing surfactant material.

These electrolytes include, among many other substances, silicates and must be used in certain amounts (eg greater than 5%) to provide their "salting out" effect.

Other patent documents disclosing the use of silicates in suspension type washing/detergent compositions include GB-A-2031455 and GB-A-1342612, wherein the suspended solids include abrasives and water-insoluble phosphate co-agents. Lotion salts, but excluding peroxygen bleach granules; indeed, GB-A-2158453, which refers to the use of perborate as a possible bleaching ingredient in liquid compositions of the suspension type, specifically advocates that these compositions must not Contains silicate, otherwise must contain carboxylic acid anti-gelling agent.

Silicates have also been broadly described as alkaline builder components of aqueous thixotropic liquid compositions used, for example, for automatic dishwashing purposes. A representative example of this technology is EP-315024, which discloses a silicate dosage in the range of 25%-40%.

It has now surprisingly been found that low levels of silicate effectively suspend peroxygen bleach particles in liquid detergent compositions of the type described in EP-A-293040 and only moderately increase the viscosity of the composition. The suspension system of the present invention does not involve any special handling difficulties; moreover, the presence of the silicate confers the advantages of increased alkalinity and improved washing machine compatibility.

Accordingly, the present invention provides desirable phase-stable aqueous liquid detergent compositions comprising a solid peroxygen bleach compound, a liquid phase consisting of water and a water-miscible organic solvent, and means for suspending the peroxygen bleach in the liquid phase. Low silicate content of bleach granules.

The present invention relates to stable liquid detergent compositions having a pH of at least 8 and less than about 11 comprising a water-soluble solid peroxygen compound suspended in a solution comprising water and at least one In the liquid phase of the water-miscible organic solvent, the water-soluble solid peroxygen compound exists in an amount such that the amount of effective oxygen provided by the peroxygen compound is 0.5% to 3%, and the composition contains 0.5% to 5%, Preference is given to 1% to 3% by weight of silicate.

water soluble peroxygen compound

The amount of water-soluble solid peroxygen compound in the composition of the present invention is preferably 5-50% (by weight of the composition), more preferably 5-40%, more preferably 5-30%, most preferably 10-30% (weight).

Examples of suitable water-soluble solid peroxygen compounds include perborates, persulfates, peroxodisulfates, perphosphates, and crystalline peroxides formed by the reaction of hydrogen peroxide with sodium carbonate (to form percarbonate) or urea. oxygen hydrate. Preferred peroxygen bleaching compounds are perborates and percarbonates.

The most preferred bleaching agent herein is a granular perborate bleach, the particles having a weight average particle size of 0.5-20 microns, preferably 3-15 microns.

Small average particle sizes are best obtained by in situ crystallization, especially for perborate monohydrate.

In situ crystallization includes procedures involving dissolution and recrystallization, such as dissolution of perborate monohydrate followed by formation of perborate tetrahydrate. Recrystallization can also be produced by allowing the perborate monohydrate to absorb water of crystallization, whereby the monohydrate is directly recrystallized into the tetrahydrate, eliminating the dissolution step.

In situ crystallization also includes processes involving chemical reactions, such as when stoichiometric amounts of hydrogen peroxide react with sodium metaborate or borax to form sodium perborate.

Organic solvents miscible with water

The suspension system of the solid peroxygen component herein is a liquid phase comprising water and a water-miscible organic solvent. This makes it possible to incorporate large amounts of water-soluble solid peroxygen compounds into the liquid detergent compositions herein, while maintaining the available oxygen level in solution below 0.5%, preferably below 0.1%, by weight of the liquid phase. The amount of peroxygen compound dissolved in the liquid phase is less than one-tenth of its total amount; in fact, the low content of available oxygen in the solution determines the stability of the system.

Standard iodometric methods (eg as described by Methodender Orgonischen Chemie, Houben Weyl, 1953, Vol. 2, p. 562) are suitable for measuring the available oxygen (AVO) content of compositions.

To ensure complete equilibrium between the liquid and solid phases, the mixed composition was allowed to stand at room temperature for three days before performing the AVO titration test. To ensure correct sampling, the product should be shaken thoroughly before determination.

To measure available oxygen (AVO) in the liquid phase, a sample of the composition was centrifuged at 10,000 rpm for 10 minutes. The liquid is then separated from the solid, and the liquid is titrated to determine the amount of available oxygen.

It is not necessary for the organic solvent to be completely miscible with water, so long as enough organic solvent is mixed with water in the composition to affect the solubility of the peroxygen compound in the manner described. Solvents that are completely miscible with water are preferably used herein.

Of course, the water miscible organic solvent must be compatible with the peroxygen bleach compound at the pH used. Therefore, polyols with adjacent hydroxyl groups such as 1,2-propanediol and glycerol should not be used when the peroxygen bleach compound is perborate.

Examples of suitable water-miscible organic solvents include lower aliphatic monohydric alcohols; ethers of diethylene glycol and lower monoaliphatic monohydric alcohols; especially ethanol; n-propanol; isopropanol; butanol; polyethylene glycols (e.g. PEG 150, 200, 300, 400); dipropylene glycol; hexanediol; methoxyethanol; ethoxyethanol; butoxyethanol; ethyl diglycol ether; benzyl alcohol; butoxypropanol; butoxypropoxy propanol; and mixtures thereof. Preferred solvents include ethanol; isopropanol; 1-methoxy-2-propanol and butyl diglycol ether. A preferred solvent system is ethanol. Ethanol is preferably present in a water:ethanol ratio of from 8:1 to 1:3.

The amount of available oxygen in a solution depends largely on the ratio of water to organic solvent, although the presence or absence of other components also plays a role. However, it is not necessary to use more solvent than is required to maintain the amount of available oxygen in solution below 0.5%, preferably below 0.1%.

In practice, for most systems, the ratio of water:organic solvent is in the range of 5:1 to 1:3, preferably in the range of 4:1 to 1:2.

Silicate

Silicates are present in the compositions of the invention in an amount ranging from 0.5% to 5%, preferably from 1% to 3%. The addition of such small amounts of silicate does not promote the formation of the structured surfactant phase, but unexpectedly provides effective and stable suspension of the peroxygen bleach particles with only a modest increase in the viscosity of the composition.

The silicate material used in the present invention can be a natural silicate with a ratio of _SiO2 to _Na2O from 1:1 to 4:1, preferably 1:1 (metasilicate), 1.6:1 or 2:1 1.

Sodium silicate is preferred, although potassium silicate can also be used.

Synthetic silicates can be used for the purposes of this invention, such as Sydex 120, the ratio of SiO ₂ to MgO is 3.5:1.

The liquid bleach-containing detergent compositions of the present invention exhibit a pH (1% solution in distilled water) of at least 8 and less than about 11, preferably at least 9, more preferably at least 9.5. An alkaline pH results in good bleaching action of the peroxygen compound, especially when the peroxygen compound is a perborate.

Surfactant

The compositions of the present invention preferably contain nonionic or cationic surfactants, or mixtures of both surfactants, in a total amount of surfactants from 1% to 20%, most preferably from 3% to 10%.

Nonionic surfactants are generally prepared by the condensation of ethylene oxide with hydrocarbons bearing active hydrogen atoms such as hydroxyl, carboxyl or amido groups in the presence of acidic or basic catalysts. Such surfactants include compounds having the general formula RA( _CH2CH2O ) _nH , wherein R represents a hydrophobic moiety, A _represents a group bearing an active hydrogen atom, and n represents the average number of oxirane moieties. R generally contains about 8-22 carbon atoms. Nonionic surfactants can also be prepared by condensation of 1,2-propylene oxide with low molecular weight compounds. n typically varies from about 2 to about 24.

The hydrophobic portion of the nonionic compound is preferably a primary or secondary, straight or branched chain aliphatic alcohol having from about 8 to about 24, preferably from about 12 to about 20 carbon atoms. A more complete disclosure of suitable nonionic surfactants is found in U.S. Patent 4,111,855. Mixtures of nonionic surfactants are also suitable.

A preferred class of nonionic ethoxylates is represented by the condensates of fatty alcohols having 12-15 carbon atoms with about 4-10 moles of ethylene oxide per mole of fatty alcohol.

Suitable materials for such ethoxylates include: condensates of C ₁₂ -C ₁₅ oxo alcohols with 7 moles of ethylene oxide per mole of alcohol; narrow cut C ₁₄ -C ₁₅ oxo alcohols with per mole of fat (oxo ) condensates of alcohols with 7 or 9 moles of ethylene oxide; condensates of narrow cut C ₁₂ -C ₁₃ fatty (oxo) alcohols with 6.5 moles of ethylene oxide per mole of fatty alcohol; and C ₁₀ -C ₁₄ coconut fats Condensate of alcohol, the degree of ethoxylation (mole EO/mole fatty alcohol) is in the range of 5-8. The predominantly linear aliphatic oxo alcohols may have some degree of branching, especially with short chains such as methyl branches, depending on the preparation conditions and the olefin feed.

Commercially available oxo alcohols often have a degree of branching in the range from 15% to 50% (% by weight).

The preferred nonionic ethoxylated component can also be represented as a mixture of two separately ethoxylated nonionic surfactants having different degrees of ethoxylation. For example, nonionic ethoxylated surfactants contain a first ethoxylate of 3-7 moles of ethylene oxide per mole of hydrophobic moiety and a second ethoxylate of 8-14 moles of ethylene oxide per mole of hydrophobic moiety. oxides. Preferred nonionic ethoxylated mixtures contain lower ethoxylates, i.e. C ₁₂ -C ₁₆ oxo alcohols (with up to 50% branching by weight) with about 3-7 moles of epoxy per mole of fatty oxo alcohol. Condensates of ethane, and higher ethoxylates, that is, C ₁₆ -C ₁₉ oxo alcohols (with more than 50% by weight branching) with about 8-14 moles of ethylene oxide per mole of branched oxo alcohols of condensates.

Semi-polar nonionic surfactants include water-soluble amine oxides containing an alkyl or hydroxyalkyl moiety of about 8 to about 28 carbon atoms and two moieties selected from alkyl or hydroxyalkyl groups, These alkyl or hydroxyalkyl groups contain from 1 to about 3 carbon atoms and may be optionally joined to form ring structures.

The liquid detergent compositions of the present invention optionally contain a cationic surfactant, preferably from 0.1% to 10%, more preferably from 0.1% to 5%, by weight of the composition.

Examples of suitable cationic surfactants include quaternary ammonium compounds of the formula R ₁ R ₂ R ₃ R ₄ N ^{+ X-} , wherein R ₁ is C ₁₂ -C ₂₀ alkyl or hydroxyalkyl; R ₂ is C ₁ - C ₄ alkyl or hydroxyalkyl or C ₁₂ -C ₂₀ alkyl or hydroxyalkyl or C ₁ -C ₄ hydroxyalkyl; R _{and R} are each C ₁ -C ₄ alkyl or hydroxyalkyl, or C ₆ -C ₈ aryl or alkylaryl; and X ^- is halogen. A single long-chain quaternary ammonium compound (such as a compound in which R ₂ is C ₁ -C ₄ alkyl or hydroxyalkyl in the above formula) is preferred.

Zwitterionic surfactants useful in the compositions of the present invention include derivatives of aliphatic quaternary ammonium, phosphonium and phosphonium compounds wherein the aliphatic moiety may be straight or branched and one of the aliphatic substituents contains about 8- About 24 carbon atoms, another substituent contains at least one anionic water-solubilizing group. Particularly preferred zwitterionic materials are ammonium ethoxylated sulfonates or ammonium sulfates, disclosed in U.S. Patents 3,925,262 (Laughlin et al., issued December 9, 1975) and 3,929,678 (Laughlin et al. , issued on December 30, 1975).

The compositions herein may also contain anionic surfactants. Anionic detergents are well known in the detergent art and have found widespread use in commercial detergents. Suitable synthetic anionic surface-active salts are selected from the group consisting of sulfonates and sulfates. Preferred synthetic anionic water-soluble sulfonates or sulfates have alkyl groups containing from about 8 to about 22 carbon atoms in their molecular structure.

Accordingly, if anionic surfactants are used, they are present in amounts up to 40% by weight, preferably 1% to 30% by weight, more preferably 5% to 20% by weight.

Synthetic anionic surfactants can be represented by the general formula R ¹ SO ₃ M, wherein R ¹ represents a linear or branched alkyl group selected from about 8 to about 24 carbon atoms and contains about 9 to about 15 carbon atoms in the alkyl moiety. A hydrocarbon group of an alkylphenyl group of carbon atoms; M is a salt-forming cation, generally selected from sodium, potassium, ammonium ions, or a combination of these ions.

Preferred synthetic anionic surfactants are the water-soluble salts of alkylbenzenesulfonic acids having 9-15 carbon atoms in the alkyl group. Another preferred class of synthetic anionic surfactants are the water-soluble salts of alkyl sulfates or alkyl polysorbate sulfates, wherein the alkyl group contains from about 8 to about 24, preferably from about 10 to about 20 carbon atoms, And it preferably contains about 1 to about 12 ethoxy groups. U.S. Patent 4,170,565 (Flesher et al., issued October 9, 1979) discloses other suitable anionic surfactants.

Examples of such preferred anionic surfactant salts are: reaction products obtained by sulfation of _C8 - _C18 fatty alcohols derived from tallow and coconut oil; alkylbenzenesulfonic acids in which the alkyl group contains about 9-15 carbon atoms; Salts; sodium alkyl glyceryl ether sulfonates; ether sulfates of fatty alcohols derived from tallow and coconut oil; coconut fatty acid monoglyceride sulfates and sulfonates; and containing from about 8 to about 22 carbons in the alkyl chain Atomic alkane sulfonates are water-soluble salts. Sulfonated olefinic surfactants can also be used, such surfactants are more fully described, for example, in U.S. Patent Specification 3,332,880. The neutralizing cations used for the anionic synthesis of sulfonates and/or sulfates are common cations such as sodium and potassium, which are widely used in detergent technology.

Particularly preferred anionic synthetic surfactant components herein are the water-soluble salts of alkylbenzenesulfonic acids, especially sodium alkylbenzenesulfonates having from about 10 to about 13 carbon atoms in the alkyl group.

builder

The composition of the present invention may contain a builder, the content of which is preferably not more than 50%, and the more preferred content accounts for 5%-40% of the whole composition.

If used, these builders may consist of the inorganic or organic types which have been described in the prior art.

The liquid detergent compositions of the present invention optionally contain a fatty acid component as a builder. However, the level of fatty acid is preferably less than 10%, more preferably less than 4% by weight of the composition.

Preferred saturated fatty acids have 10-16 carbon atoms, more preferably 12-14 carbon atoms. Preferred unsaturated fatty acids are oleic acid and palmitoleic acid.

Examples of inorganic builders include phosphorus-based builders such as sodium tripolyphosphate, sodium pyrophosphate, and aluminosilicates (zeolites).

Representative examples of organic builders are polyacids such as citric acid, nitrilotriacetic acid, and mixtures of tartrate monosuccinate and tartrate disuccinate. Preferred builders for use herein are citric acid and alk(en)yl substituted succinic acid compounds wherein the alk(en)yl group contains 10-16 carbon atoms. An example of this group of compounds is dodecenylsuccinic acid. Polymeric carboxylate builders including polyacrylates, polyhydroxyacrylates and polyacrylate/polymaleate copolymers can also be used and are best combined with the above preferred builders such as citric acid and alk(ene) Use in combination with substituted succinic acid compounds.

Other components/additives

The compositions of the present invention may also contain other ingredients and/or additives, preferably at levels below about 5%. Non-limiting examples of these additives (more preferably used at levels of 0.05% to 2%) include polyaminocarboxylate additives such as ethylenediaminotetraacetic acid, diethylenetriamino-pentaacetic acid, ethylene Diaminodisuccinic acid or its water-soluble alkali metal salt. Other additives used in this amount include organo-phosphonic acids; particular preference is given to ethylenediaminotetramethylenephosphonic acid, diethylenetriaminopentamethylenephosphonic acid and aminotrimethylenephosphonic acid, hydroxyethylene diphosphonic acid. Bleach stabilizers such as ascorbic acid, dipicolinic acid, sodium stannate, 8-hydroxyquinoline, hydroxyethylenediphosphonic acid (HEDP) and diethylenetriaminepenta(methylenephosphonic acid) are also available as per These amounts are included in the composition, more preferably in an amount of 0.01-1%.

The compositions of the present invention may contain a range of more optional ingredients, most of which are used in additive amounts, usually below about 5%. Examples of such ingredients include: polyacids, enzymes and enzyme catalytic stabilizers, suds regulators, opacifiers, agents to improve washing machine compatibility (for enamel-coated surfaces), biocides, dyes, fragrances, brighteners , softener, etc.

As mentioned above, detersive enzymes can be used in the liquid detergent compositions of the present invention. In fact, a desirable feature of the compositions of the present invention is that these compositions are compatible with detersive enzymes. Suitable enzymes include detergent proteases, amylases, lipases and cellulases. Enzyme-catalyzed stabilizers for liquid detergents are well known. If used, an enzyme stabilizer is preferably used in an amount in the range of about 0.5% to 5%. Preferred enzyme catalytic stabilizers for use herein are formic acid, acetic acid and salts thereof such as sodium formate and sodium acetate. More preferred stabilizers are sodium formate and acetic acid.

Application of the composition

The composition of the present invention is primarily intended to be used in the wash cycle of a washing machine; however other applications are also conceivable, such as pre-treatment of heavily soiled fabric products or soaking products; its use is not necessarily limited to the scope of the washing machine, and the inventive The compositions can be used alone or in combination with compatible handwashing compositions.

Some typical liquid detergent compositions of the present invention have the following formulations:

Example

Component Composition Weight %

Ⅰ Ⅱ Ⅲ Ⅳ Ⅴ Ⅵ

Linear alkylbenzene sulfonate 10 12 10 8 10 12

C ₁₃ -C ₁₅ Alcohol Ethoxylates (EO ₃ ) 5 0 0 10 5 3

C ₁₃ -C ₁₅ alcohol ethoxylates (EO ₇ ) 0 7 5 0 2 4

Citric acid 2.5 3.5 4 1 2.5 3

Dodecenylsuccinic acid 8.5 7 6.5 10 8.5 8

Polycarboxylate Builder 1.5 1.5 2 1.5 1.5 1

Tallow Fatty Acid - 1.5 2 - - 1

Diethylene triamine penta(methylene phosphonic acid) 0.5 0.5 0.4 0.5 0.5 0.4

Hydroxyethylene diphosphonic acid 0.2 0.2 0.3 0.2 0.3 0.4

Sodium formate 1.5 1 1.5 1.5 1 2

Acetic acid 1.4 1.5 1.4 1.4 2 -

Ethanol 8 10 12 10 14 14

Sodium perborate monohydrate 14 - 14 - - 14

Sodium perborate tetrahydrate - 20 - 22 20 -

Silicate SiO ₂ : Na ₂ O = 1.6 1 3 - - - -

Silicate SiO ₂ : Na ₂ O = 2.0 - - 1.5 3 - -

120 - - - - 1 4Sydec

120 - - - - 1 4

Sodium hydroxide ...greater than PH9.5...

Water + Minor Substances (Fragrances, Brighteners, Enzymes...) ...Balanced to 100...

Claims (8)

1, a kind of pH value is at least 8 and less than about 11 stable liquid detergent compositions, be characterised in that it comprises the water-soluble solid peralcohol that is suspended in the liquid phase, described liquid phase contains water and organic solvent at least a and that water dissolves each other, the amount of water-soluble solid peralcohol makes that the available oxygen amount that is provided by this peralcohol is that described composition contains the silicate of 0.5%-5% weight from 0.5%-3%.

2, according to the detergent composition of claim 1, wherein the content of silicate is 1%-3%.

3, according to the liquid detergent composition of claim 1 and 2, be aliphatic monohydric alcohol wherein with the organic solvent that water dissolves each other.

4, according to the liquid detergent composition of claim 2, be ethanol wherein with the organic solvent that water dissolves each other, and water: proportion of ethanol is 8: 1-1: 3, preferred 5: 1-1: 2.

5, according to claim 1,2 or 3 liquid detergent composition, wherein the water-soluble solid peralcohol is four water perborate, and its content is the 5%-30% of composition total weight.

6, according to the composition of claim 5, wherein four water perborate bleaches are particulate state, have 0.5 micron-20 microns weight average particle diameter.

7, according to the composition of claim 5, wherein four water perborate particles form by a water perborate recrystallization.

8, according to claim 1,2 or 3 composition, wherein the water-soluble solid peralcohol is a percarbonate.