DETERGENT CONTAINING A FABRIC CONDITIONER

Abstract: Intimate mixtures of certain amines and a Bronstedt acid are useful for mixing with conventional detergent ingredients to provide through-the-wash fabric softening.

Description: Technical Field The present invention relates to granular detergent compositions having fabric softening properties. Certain amines in intimate mixture with a dispersing aid in the compositions provide through-the-wash softness and anti-static benefits. Detergent compositions in spray-dried form containing said amines are disclosed. the compositions also contain a clay softener Background The use of softeners to treat fabrics subsequent to a washing operation is a well known laundering practice. Fabric softeners are, in the main, cationic materials which are incompatible with anionic detersive surfactants used in most fabric washing compositions. For that reason, the softening operation is generally carried out in the laundry rinse bath after the surfactant has been removed from the washing machine. This entails additional work for the user. Formulators of fabric laundering compositions have long sought means whereby the fabric washing and softening could be done concurrently. Methods employing clay softeners, amine complexes or mixtures of clay and various amine materials, and the like, are described in the following patents : German 29 64 114, 28 57 163, 24 39 541, 23 34 899 and EP 0 023 367, 0 026 528 and 0 028 432, and in EP-A-123400, EP-A-7135 and EP-A-133804. The use of mixtures of amines and soaps (salts of fatty acids) as through-the-wash softeners is disclosed in U.K. patent 1 514 276. The amines of this reference are selected on the basis of their having an isoelectric point of from 8.3 to 9.8, i.e. such that they have no positive charge during the wash cycle, and become positively charged during the rinse cycle. The present invention employs a certain class of amines, intimately mixed with a dispersing aid, in an otherwise conventional detergent composition matrix, and clay, to provide cleaning and, concurrently, softening. Summary of the Invention The compositions herein may be described succinctly as granular detergent compositions which contain conventional detergent ingredients such as detersive surfactants (including anionics), detergency builders and optionally optical brighteners, detersive enzymes, fabric bleaches, and the like, all at conventional levels, which contain clay fabric softeners (preferably, smectite clays), which further contain at least 0.1 % (preferably 1.0 % to 20 %) of an amine having an isoelectric point of at least 9.5, preferably those of the formula R₁R₂R₃N, wherein R₁ is C₉ to C₂₀ hydrocarbyl and R₂ and R₃ are each C₁ to C₄ hydrocarbyl, C₂ to C₁₀ alkoxylated hydrocarbyl or hydrogen, the amine being in intimate mixture with a dispersing aid, wherein said dispersing aid is a polycarboxylin acid or an inorganic acid. The amine/acid mixture is sprayed onto the granular detergent matrix. Detailed Description of the Invention As noted hereinafter, the compositions of this invention comprise, in major part, conventional ingredients that are quite familiar to formulators of granular detergent compositions. Surprisingly, the amines used herein are entirely compatible with such conventional detergent ingredients, even anionic surfactants. Amine The amines suitable for the compositions herein are selected so that they have an isoelectric point in excess of 9.5, preferably in excess of 10.0. Examples are amines having general formula R₁R₂R₃N, wherein R₁ is C₈ to C₂₀ hydrocarbyl, preferably C₈ to C₂₀ alkyl, more preferably C₁₀ to C₁₄ alkyl, and most preferably C₁₂ alkyl or a mixture of C₁₂ and C₁₄ alkyl. R₂ and R₃ are each, independently, C₁ to C₁₀, hydrocarbyl, or hydrogen. Examples of suitable hydrocarbyl radicals are C₁ to C₄ alkyl or hydroxyalkyl, and C₂ to C₁₀ alkoxylated alkyl, in particular ethoxylated alkyl radicals. Amines wherein R₂ and R₃ are identical C₁ to C₄ alkyl, especially methyl, are preferred. the dispersing aid Prior to incorporation into the detergent matrix, the amines are intimately mixed with a dispersing aid. It has been found that a specific class of compounds, most of which are not generally considered to be dispersing aids, are particularly suitable to be used as dispersing aids in combination with the amines defined herein. This class of compounds consists of polycarboxylic acids and inorganic acids, like HF, HCl, HBr, H₂SO₄, HNO₃, HNaSO₄, H₂SO₃, HNaSO₃. Although not intended to be limited by theory, a possible mechanism by which Bronstedt acids act as dispersing aids could be as follows. The acids protonate a portion of the amine. The protonated amine, in turn, acts as a dispersing aid for the remaining unprotonated amine. This mechanism suggests that protonated amines per se could be used as dispersing aids, instead, or in combination with the Bronstedt acids. The criticality of the high isoelectric point of the amines (at least 9.5, preferably 10.0 or higher) suggest that it is important that, if protonation indeed takes place, the amines remain protonated during the wash cycle of a laundry program. On the other hand, it is critical that the dispersing aid be intimately mixed with the amine. Simply allowing the amines to be contacted by the dispersing aid in the wash liquor apparently is not sufficient to obtain the superior softening performance. In general terms, the amine/dispersing aid mixtures which are key to this invention are prepared separately from the balance of the composition and then the sprayed onto the granular detergent matrix. If the dispersing aid is a Bronstedt acid, this can most conveniently be done by preparing a melt (preferably 1:1 mole ratio) of the acid and the amine and maintaining under continuous mixing the melt stage for about ten minutes whereby the complex forms. If the dispersing aid is an acid, the molar ratio amine : acid preferably is about 1:1, but good fabric softening results can also be obtained by mixing the amine with a sub-stoichiometric amount of acid. For good results, the acid : amines ratio should be at least 1:10, preferably at least 1:5. The amine/dispersing aid mixtures are used herein at levels of at least 0.1 %, typically at levels of 0.5 % to 20 %, most preferably from 1 % to 10 % of the detergent compositions. Softener Clay The protonated amine is used 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 kaolines and various multi-layer smectites. Preferred clay softeners are smectite softener clays that are described in German patent document 2 334 899 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 2-7 %. Detersive Surfactants The compositions of this invention will contain 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 alkylbenzene sulfonates, alkyl- and alkylether sulfates, paraffin sulfonates, olefin sulfonates, alkoxylated (especially ethoxylated) alcohols and alkyl phenols, amine oxides, α- 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 tri-ethanolammonium 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 %, 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. Detersive Adjuncts - The compositions herein can contain other ingredients which aid in their cleaning performance. For example, the present 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 (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 µm size zeolite (e.g. zeolite A) builders disclosed in German patent 2.422.655 are especially preferred for use in low 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. Amylase, protease and lipase 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. 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, bleach, optical brighteners, soil suspending agents, hydrotropes and gel-control agents, freeze-thaw stabilizers, bactericides, preservatives, suds control agents, bleach activators and the like. 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, preferably at pH 9-11, to launder fabrics. The laundering can be carried out over the range from 5°C to the boil, with excellent results. Industrial Application The following example is typical of the preparation of an amine/dispersing aid mixture to be used in the preferred compositions of this invention containing smectite softener clays, but is not intended to limit the scope of the invention. Example Preparation of the dimethyl myristyl amine/citric acid mixture Citric acid is dissolved in methanol (at ca. 30°C). After the addition of the amine, the mixture is stirred for about 15 minutes. Then the methanol is evaporated (e.g. by heating) and the solid residue (mixture of citric acid/dimethyl myristyl amine) is subsequently dried and ground to the desired particle size. This method for preparing the mixture of amine/dispersing aid is suitable when the melting point of the dispersing aid is too high.

Claims: A granular detergent composition comprising detersive surfactant, builders, a clay softener, conventional detersive ingredients, and at least 0.1% of an intimate mixture of an amine having an iso-electric point of at least 9.5, and a dispersing aid, characterized in that the dispersing aid is a polycarboxylic acid or an inorganic acid, and that said mixture is sprayed onto the granular detergent matrix. A composition according to claim 1 wherein the amine has an iso-electric point of at least 10.0. A composition according to claim 1 or 2 wherein the amine has the formula R₁R₂R₃N wherein R₁ is C₈ to C₂₀ hydrocarbyl, and R₂ and R₃ are each C₁ to C₄ hydrocarbyl, C₂ to C₁₀ alkoxylated hydrocarbyl, or hydrogen. A composition according to any of the preceding claims wherein the amine and the dispersing aid are present in an (amine): (dispersing aid) molar ratio in the range as from 10:1 to 1:5. A composition according to any of the preceding claims which contains from 0.5% to 20% of the amine/dispersing aid mixture. A composition according to any of the preceding claims wherein the amine/dispersing aid mixture is prepared by admixing same at a temperature above the melting point of both the amine and the dispersing aid. A composition according to any of the preceding claims wherein the clay softener is a smectite clay.

Inventors: BAECK, ANDRE, BUSCH, ALFRED
Applicants: PROCTER & GAMBLE EUROPEAN TECHNICAL CENTER
Application year: 1986
Main classification: C11D3
IPC codes: C11D3, C11D1, D06L1