Softening and bleaching detergent compositions containing amide softening agent

Technical Field

The present invention relates to softening detergent compositions containing a peroxyacid-bleaching compound, and a narrowly-defined amide softening agent.

The compositions herein, in addition to providing good cleaning performance, exhibit excellent through-the-wash softening properties, and provide additional fabric-care benefits such as anti-static, anti-wrinkling, ease-of-ironing, color stability, independently from and in presence of peroxyacid bleaching agents.

Background of the invention

Formulators of fabric treatment compositions have long sought means for simultaneously washing and softening fabrics. Among the various approaches suggested are methods employing clay softeners, or amine materials, or both ingredients in combination, such as described in e.g.: German Patents 29.64.114, 28.57.16, 24.39.541, 23.34.899 and European Patents 0 026 528 and 0 028 432.

Amines have been used in combination with soaps (U.K. patent 1 514 276), fatty acids (published E.P.A. 0 133 804) or phosphate esters (published E.P.A. 0 168 889) as through-the-wash softeners.

It has been found, however, that the presence of peroxyacid-bleach compounds in softening detergent compositions is often detrimental to the stability of the amine softening agent. As a consequence, the utilization of peroxyacid bleaching agents, inclusive of peroxygen bleach-activator combinations, was in such compositions often limited in quantity, and optimum performance could therefore not be obtained. In addition, the softening amine is not well-compatible with peroxyacids, and becomes deactivated as a softener.

Carboxy-amides have been used as antistatic agents in industrial textile treatment (German patent 30 43 618) and N-alkyl isostearamides as antistatic agents in laundry application (French patent 2,531,447); N-alkyl (15-21 alkylamides have been used as foam suppressors in detergent compositions (US-A-3231508).

Japanese patent J5 8144-175-A discloses the industrial treatment of textile by cationic softening agents and ethoxylated fatty acid amides.

Alkoxylated fatty amides are known as surfactants (EP-A-0 000 595) and as viscosity control agents (EP-A-0 112 719).

German Patent Application 19 59 007 discloses the use as softening agent of a monoethanolamide. German Patent Application 33 10 417 discloses the use of fatty acids diethanolamides as antistatic/non-yellowing agents.

It is an object of the present invention to provide detergent compositions capable of providing excellent cleaning, softening, and fabric-care properties.

It is another object of the invention to formulate peroxyacid-containing detergent compositions capable of providing simultaneous cleaning and softening benefits.

It has now been discovered that the objects set forth above can be met by using certain amides as softening agents to thereby avoid interaction with peroxyacid bleaching agents and thus provide excellent results in both cleaning and softening of fabric, as well as other "fabric care" benefits.

Summary of the invention

The present invention relates to detergent compositions capable of giving through-the-wash fabric-care benefits inclusive of softeness, containing an anionic surfactant, a peroxygen bleach or a system capable of yielding a peroxyacid in situ and an amide fabric softening agent having the formula: <chemistry id="chem0001" num="0001"><img file="EP0242918B1_D0001.tif" /></chemistry> wherein R and R′ are straight chain alk(en)yl, aryl, or alkyl-aryl group, each containing from 8 to 22 carbon atoms.

Detailed Description of the Invention

The amide softening agent

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The amide softening agents for use in the present invention are represented by the formula : <chemistry id="chem0002" num="0002"><img file="EP0242918B1_D0002.tif" /></chemistry> wherein R and R′ are straight chain alk(en)yl, aryl, or alkyl-aryl groups containing from 8 to 22 carbon atoms.

Preferred amides include N-cocoalkyl stearamide, N-decyl stearamide, N-cocoalkyl lauramide, N-tallow tallowamide, N-decyl tallowamide.

The amide softening agent is preferably used at levels of from 0.1% to 15% by weight, more preferably from 1 to 10% by weight of the detergent composition, most preferably from 3% to 6%.

In a highly preferred embodiment of the present invention, the amide softening agent is pre-mixed with a dispersing agent, and the resulting mixture is then added to the rest of the composition.

Any conventional dispersing agent with a suitable HLB value can be used herein. Examples are nonionic surfactants resulting from the condensation of primary or secondary aliphatic alcohols or alkyl phenol, with polyethylene oxide. Specific examples include the condensation products of tallow alcohol with 5 to 12 ethylene oxide units in the molecule.

Suitable as dispersing agents are also phosphate esters described in the published European patent application n° 0168889, such as those of the formula: R′-O(CH₂-CH₂O)_mPO(OH)₂, with R′=C₁₂₋₁₄ and m=1-5, sold under the Trade Name "Servoxyl VPAZ"®

However, it is a preferred embodiment of the present invention to use fatty acids as dispersing agents for the amide softening agent.

Fatty acids like lauric, myristic, palmitic, stearic, oleic acids and mixtures thereof can advantageously be used in the present context.

Especially preferred is a mixture of palmitic and stearic acids.

Fatty acids dispersing agents are used most preferably in a weight ratio of 1/1 to 10/1 of amide softening agent to fatty acid.

Softener Clay

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The amide softening agent is preferred, but not limited, for use in combination with a detergent-compatible clay softener. Such clay softeners are well-known in the detergency patent literature and are in broad commercial use, both in Europe and in the United States. Included among such clay softeners are various heat-treated kaolins and various multi-layer smectites. Preferred clay softeners are smectite softener clays that are described in German Patent Application 23 34 899 and in U.K. Patent 1.400.898, which can be referred to for details. Softener clays are used in the preferred compositions at levels of at least 1%, generally 1-20%, preferably 2-10%.

Detersive surfactants

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The compositions of this invention will contain anionic and optionally other organic surface-active agents ("surfactants") to provide the usual cleaning benefits associated with the use of such materials.

Detersive surfactants useful herein include well-known synthetic anionic, nonionic, amphoteric and zwitterionic surfactants. Typical of these are the alkyl benzene sulfonates, alkyl- and alkylether sulfates, paraffin sulfonates, olefin sulfonates, alkoxylated (especially ethoxylated) alcohols and alkyl phenols, amine oxides, alpha-sulfonates of fatty acids and of fatty acid esters, and the like, which are well-known from the detergency art. In general, such detersive surfactants contain an alkyl group in the C₉-C₁₈ range; the anionic detersive surfactants can be used in the form of their sodium, potassium or triethanolammonium salts; the nonionics generally contain from 5 to 17 ethylene oxide groups. U.S. Patent 4.111.855 contains detailed listings of such typical detersive surfactants. C₁₁-C₁₆ alkyl benzene sulfonates, C₁₂-C₁₈ paraffin-sulfonates and alkyl sulfates, and the ethoxylated alcohols and alkyl phenols are especially preferred in the compositions of the present type.

Also useful herein as the surfactant are the water-soluble soaps, e.g. the common sodium and potassium coconut or tallow soaps well-known in the art.

The surfactant component can comprise as little as 1% of the compositions herein, but preferably the compositions will contain 5% to 40%, more preferably 10% to 30%, of surfactant. Mixtures of the ethoxylated nonionics with anionics such as the alkyl benzene sulfonates, alkyl sulfates and paraffin sulfonates are preferred for through-the-wash cleansing of a broad spectrum of soils and stains from fabrics.

Bleaching compound

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The bleaching compound in the context of the present invention is represented by a peroxyacid bleaching agent. In the context of the present invention, peroxyacid bleaching agent encompasses both a peroxyacid "per se" and systems which are able to yield peroxyacids in situ.

Peroxyacids "per se" are meant here to include the alkaline and alkaline-earth metal salts thereof. Peroxyacids and diperoxyacids are commonly used; examples are diperoxydodecanoic acid (DPDA) or peroxyphthalic acid.

Systems capable of delivering peracids in situ consist in a peroxygen bleaching agent and an activator therefor.

The peroxygen bleaching agents are those capable of yielding hydrogen peroxide in an aqueous solution; those compounds are well-known in the art, and include hydrogen peroxide, alkali-metal peroxides, organic peroxide bleaching agents such as urea peroxide, inorganic persalt bleaching agents such as the alkali metal perborates, percarbonates, perphosphates, persilicates, and the like.

Preferred are sodium perborate, commercially available in the form of mono- and tetra-hydrates, sodium carbonate peroxyhydrate, sodium pyrophosphate peroxyhydrate, urea peroxyhydrate.

The liberated hydrogen peroxide reacts with the bleach activator to form the peroxyacid bleach. Classes of bleach activators include esters, imides, imidazoles, oximes, and carbonates. In those classes, preferred materials include methyl o-acetoxy benzoates; sodium-p-acetoxy benzene sulfonates such as sodium 4-nonanoyloxybenzene sulfonate; sodium-4-octanoyloxybenzene sulfonate, and sodium-4-decanoyloxybenzenesulfonate: bisphenol A diacetate; tetra acetyl ethylene diamine; tetra acetyl hexamethylene diamine; tetra acetyl methylene diamine.

Other highly preferred peroxygen bleach activators which are disclosed in U.S Patents 4.483.778 and 4.539.130, are alpha-substituted alkyl or alkenyl esters, such as sodium-4(2-chlorooctanoyloxy)benzene sulfonate, sodium 4-(3,5,5-trimethyl hexanoyloxy)benzene sulfonate. Suitable peroxyacids are also peroxygen bleach activators such as described in published European Patent Application N° 0 166 571, i.e., compounds of the general type RXAOOH and RXAL, wherein R is a hydroxycarbyl group, X is a hetero-atom, A is a carbonyl bridging group and L is a leaving group, especially oxybenzenesulfonate.

Detersive adjuncts

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The compositions herein can contain other ingredients which aid in their cleaning performance. Through-the-wash detergent compositions contain a detergent builder and/or metal ion sequestrant. Compounds classifiable and well-known in the art as detergent builders include the nitrilotriacetates, polycarboxylates, citrates, water-soluble phosphates such as tri-polyphosphate and sodium ortho- and pyro-phosphates, silicates, and mixtures thereof. Metal ion sequestrants include all of the above, plus materials like ethylenediaminetetraacetate, the amino-polyphosphonates and phosphates (DEQUEST®) and a wide variety of other poly-functional organic acids and salts too numerous to mention in detail here. See U.S. Patent 3.579.454 for typical examples of the use of such materials in various cleaning compositions. In general, the builder/sequestrant will comprise 0.5% to 45% of the composition. The 1-10 micrometer size zeolite (e.g. zeolite A) builders disclosed in German Patent 24 22 655 are especially preferred for use in low-phosphate or non-phosphate compositions.

The laundry compositions herein also preferably contain enzymes to enhance their through-the-wash cleaning performance on a variety of soils and stains, such as amylase &amp; protease enzymes. Amylase and protease enzymes suitable for use in detergents are well-known in the art and in commercially available liquid and granular detergents. Commercial detersive enzymes (preferably a mixture of amylase and protease) are typically used at levels of 0.001% to 2%, and higher, in the present compositions. Other highly desirable detergent ingredients for use in the detergent compositions of the present invention are quaternary ammonium compounds of the form R₄R₃R₆R₇N⁺X⁻, wherein R₄ is alkyl having from 10 to 20, preferably from 12-18 carbon atoms, and R₅,R₆ and R₇ are each C₁ to C₄ alkyl preferably methyl: X⁻ is an anion, e.g. chloride. Examples of such quaternary ammonium compounds include C₁₂-C₁₄ alkyl trimethyl ammonium chloride and cocoalkyl trimethyl ammonium methosulfate. The quaternary ammonium compounds can be used at levels from 0.5% to 5%, preferably from 1% to 3%.

Moreover, the compositions herein can contain, in addition to ingredients already mentioned, various other optional ingredients typically used in commercial products to provide aesthetic or additional product performance benefits. Typical ingredients include pH regulants, perfumes, dyes, optical brighteners, soil suspending agents, hydrotropes and gel-control agents, freeze-thaw stabilizers, bactericides, preservatives, suds control agents, bleach stabilizing agents.

In a through-the-wash mode, the compositions are typically used at a concentration of at least 500 ppm, preferably 0.10% to 1.5%, in an aqueous laundry bath at pH 7-11 to launder fabrics. The laundering can be carried out over the range from 5°C to the boil, with excellent results.

Form and Preparation of the compositions

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The detergent compositions of the present invention can be in granular, liquid, or sheet-like form. They may be prepared in any way, as appropriate to their physical form, as by mixing the components, co-agglomerating them, micro-encapsulating them, dispersing them in a liquid carrier, releasably adsorbing or coating them onto a non-particulate substrate, such as a non-woven or paper sheet.

Preferably, the compositions are in granular form.

A highly preferred method of preparation of said granular compositions consists in preparing a melt of the dispersing agent and the amide, dispersing the molten mixture into a stirred, aqueous crutcher mix comprising the balance of the detersive ingredients, and spray-drying in standard fashion. In alternate but much less preferred modes, the melt can be atomized onto the detergent granule or allowed to solidify, ground in a colloid mill, and dry-mixed with the balance of the detergent composition. The compositions herein may also be sprayed onto particles of, e.g., sodium perborate mono or tetrahydrate, sodium sulfate, sodium carbonate, sodium silicate, sodium phosphate, or clay of the type described above.

Industrial Application

The following examples are typical of the preferred execution of the invention, but are not intended to limit the scope.

EXAMPLE

N-tallow tallowamide (total 6% of complete formulation after spray-drying) and stearic acid (2% of complete formulation) are admixed, melted in a jacketed batch and stirred until homogeneity. A standard aqueous crutcher mix comprising the following ingredients is prepared (percentages listed relate to percent ingredients in the complete formulation after spray-drying). <tables id="tabl0001" num="0001"><img file="EP0242918B1_D0003.tif" /></tables>

The N-tallow tallowamide/stearic acid melt is poured into the crutcher mix (60-90°C). The crutcher mix-plus-N-tallow tallowamide/stearic acid is then handled in entirely standard fashion, and spray-dried to form the final composition. After drying sodium perborate, (20%) and bleach activator (3% 3-5-5-trimethyl hexamaic acid, sulfapheryl ester, sodium salt*** are dry-mixed with the granules. *** U.S. Patents 4.483.778 &amp; 4.539.130.

Very good results were obtained in softness and fabric-care benefits, compared to an identical composition which did not contain the N-tallow tallowamide/stearic acid premix (reference).