TEXTILE TREATMENT COMPOSITIONS

Abstract: Aqueous dispersions of certain amines, with Bronstedt acids having a pKa of at least 6, are stable and are useful as rinse-added fabric softeners.

Description: This invention relates to textile treatment compositions. More particularly it relates to textile treatment compositions suitable for use in the rinse cycle of a textile laundering operation to provide fabric softening/static control benefits, the compositions being characterized by excellent softening, water dispersibility and storage properties after prolonged storage at both elevated and sub-normal temperatures. Textile treatment compositions suitable for providing fabric softening and static control benefits during laundering were well known in the art and have found widespread commercial application. Conventionally, rinse-added fabric softening compositions contain, as the active component, substantially water-insoluble cationic materials having two long alkyl chains. Typical of such materials are di-hardened tallow dimethylammonium chloride and imidazolinium compounds substituted with two tallow groups. These materials are normally prepared in the form of a dispersion in water and it is generally not possible to prepare such aqueous dispersions with more than about 10% of cationic softener without encountering severe product viscosity and storage-stability problems. Although more concentrated dispersions of softener materials can be prepared as described in European Patent Application No. 406 and British Patent No. 1 601 360 by incorporating certain nonionic adjunct softening materials therein, such compositions tend to be relatively inefficient in terms of softening benefit/unit weight of active; moreover, product viscosity and stability problems become increasingly unmanageable in more concentrated aqueous dispersions and effectively limit the commercial range of applicability to softener active levels in the range from about 15% to about 20%. U.S. Patent 4 454 049, issued June 12, 1984 to MacGilp et al discloses concentrated liquid fabric softeners comprising substantial amounts of at least 10%, more typically about 30 - 40%, of water miscible organic solvent. U.S. Patent 2 995 520, issued August 8, 1961 to Luvisi et al discloses the use of the acid salts of certain imidazoline derivatives for softening of fibrous materials such as cotton and paper. The treatment baths used for treating textiles contain from 0.001% to 1% of an acid salt of an imidazoline derivative. For shipment, it is said to be desirable to place the materials in a low molecular weight aliphatic alcohol to prevent freezing. Other patents, more recent than U.S. Patent 2 995 520, also disclose the use of an acid salt of an imidazoline derivative for the softening of fabrics, such as FR-A-2 322 963. DE-B-2 841 076 and FR-A-2 391 312 disclose compositions for industrial treatment of textiles wherein imidazoline derivatives are used as softening agent, together with an organic fluidizer. However, according to the state of the art, quaternary ammonium salts are, in the context of fabric softening, preferred over acid salts of, e.g., acyclic tertiary amines or cyclic amines. It is therefore an object of the present invention to provide liquid fabric softening compositions that can be formulated as both diluted and concentrated aqueous dispersions without the need of significant amounts of organic solvents. The compositions of the present invention have excellent stability at both elevated and sub-normal temperatures, even under prolonged storage conditions. These compositions further provide excellent softening, anti-static and fabric rewettability characteristics across a broad range of fabric types. Summary of the Invention The present invention provides a stable aqueous dispersion comprising: (a) from 1% to 40% by weight of an amine selected from the group consisting of the di(higher alkyl) cyclic amines of formula I herein, (b) a dispersing aid selected from the group of Bronstedt acids having a pKa value of not greater than 6; provided that the pH of the dispersion is not greater than 5; and (c) at least 83ppm of Calcium Chloride as a viscosity adjusting agent, said composition being free of compounds of the formula : wherein n represents an integer from 1 to 4, R¹ and R² represent, independently from each other, a methyl or ethyl group, R³ represents hydrogen or a methyl group, R⁴ represents an alkyl group having from 7 to 15 carbon atoms with at least 7 carbon atoms in the main chain, and X⁻ represents the equivalent anion of a water-soluble organic or mineral acid. Detailed description of the invention The compositions of the present invention are based upon the discovery that stable aqueous dispersions can be formulated with certain cyclic amines, even at high amine concentration, and a Bronstedt acid as a dispersing aid, without the use of substantial amounts of organic solvent. a) The amine The amines used in the compositions of the present invention are selected from the group consisting of compounds of the formula I. wherein n is 2 or 3, preferably 2; R₁ and R₂ are, independently, a C₈-C₃₀ alkyl or alkenyl, preferably C₁₂-C₂₀ alkyl, more preferably C₁₅-C₁₈ alkyl, or mixtures of such alkyl radicals. Examples of such mixtures are the alkyl radicals obtained from coconut oil, "soft" (non-hardened) tallow, and hardened tallow. Q is CH, CH₂, NH or N, preferably N. wherein T is NR₅, R₅ being H or C₁-C₄ alkyl, preferably H, and R₄ is a divalent C₁-C₃ alkylene group or (C₂H₄O)m, wherein m is an number of from 1 to 8; or X is R₄. The compositions of the present invention comprise from 1% to 40% by weight of the amine, preferably from 3% to 35%, and more preferably from 10% to 35%. b) The dispersing aid Bronstedt acids having a pKa value of 6 or less have been found to be excellent dispersing acids for the amines of the compositions herein. Typically, the amine is heated to a temperature above its melting point. The melt is then slowly added to an aqueous solution of the dispersing aid under vigorous stirring or high shear mixing. The amount of dispersing aid should be such that the pH of the dispersion, after mixing, is not greater than 5, preferably not greater than 4, and most preferably in the range of from 2.5-4. Typically, the amount of acid is from 1% to 50% by weight of the amine, preferably from 2% to 30%, most preferably from 3 to 15%. The dispersing aid imparts a low viscosity and excellent phase stability to the dispersions, even at high amine concentrations. Examples of suitable dispersing aids include the inorganic mineral acids, carboxylic acids, in particular the low molecular weight (C₁-C₅) carboxylic acids, and alkylsulfonic acids. Suitable inorganic acids include HCl, HBr, H₂SO₄, H₂SO₃, HNO₃ and H₃PO₄. Suitable organic acids include formic, acetic, methylsulfonic and ethylsulfonic acid. Preferred acids are phosphoric, formic and methylsulfonic acid. c) Electrolyte In order to further improve the stability of the compositions herein, and further adjust their viscosities, the present compositions contain at least 83ppm of an electrolyte, CaCl₂. It has been found that the Brookfield viscosities of highly concentrated dispersions can be reduced to less than 100 cps (100 mPaS), using relatively small amounts of CaCl₂ (e.g., 600ppm). In particular, the present compositions are free of organic fluidizers, such as disclosed in FR-A-2 391 312, of the formula : wherein n represents an integer from 1 to 4, R¹ and R² represent, independently from each other, a methyl or ethyl group, R³ represents hydrogen or a methyl group, R⁴ represents an alkyl group having from 7 to 15 carbon atoms with at least 7 carbon atoms in the main chain, and X⁻ represents the equivalent anion of a water-soluble organic or mineral acid. d) Organic solvent The compositions of the present invention can be formulated without the use of any organic solvent. However, the presence of organic solvents (for example, low molecular weight, water miscible aliphatic alcohols,) does not harm the storage stability, the viscosity, or the softening performance of the compositions of this invention. Typically, the amine will be obtained from a supplier of bulk chemicals in solid form or as a solution in an organic solvent, e.g. isopropanol. There is no need, whatsoever, to remove such a solvent in making the compositions of this invention. Indeed, additional solvent may be added, if this is deemed desirable. However, compared to water, organic solvents are expensive, and difficult to handle because of their flammability and, sometimes, toxicity. It is therefore desirable to formulate the present compositions with low levels of organic solvent, i.e., less than 10%, preferably less than 2%. e) Optional quaternary ammonium salt In addition to the amine and the dispersing aid the dispersions herein optionally further contain a conventional quaternary ammonium softening agent. Examples of such conventional quaternary ammonium salts include (i) acyclic quaternary ammonium salts having the formula: wherein R₂ is an acyclic aliphatic C₁₅-C₂₂ hydrocarbon group, R₃ is a C₁-C₄ saturated alkyl or hydroxyalkyl group, R₄ and R₅ are selected from R₂ and R₃, and A is an anion. (ii) diamido quaternary ammonium salts having the formula: wherein R₁ is an acyclic aliphatic C₁₅-C₂₁ hydrocarbon group, R₂ is a divalent alkylene group having 1 to 3 carbon atoms, R₅ and R₈ are C₁-C₄ saturated alkyl or hydroxyalkyl groups, and A⁻ is an anion: (iii) diamido alkoxylated quaternary ammonium salts having the formula: wherein n is equal to 1 to 5, and R₁, R₂, R₅ and A⁻ are as defined above; (iv) quaternary ammonium compounds having the formula: wherein R₄ is an acyclic aliphatic C₁₅-C₂₂ hydrocarbon group, R₅ is a C₁-C₄ saturated alkyl or hydroxyalkyl group, A⁻ is an anion; (v) quaternary imidazolinium compounds. Examples of Component (i) are the well-known dialkyldimethylammonium salts such as ditallowdimethylammonium chloride, ditallowdimethylammonium methylsulfate, di(hydrodrogenated tallow) dimethylammonium chloride, distearyldimethylammonium chloride, dibehenyldimethylammonium chloride, the monoalkyltrimethylammonium salts such as monotallowtrimethylammonium chloride, mono(hydrogenated tallow) trimethylammonium chloride, palmityltrimethylammonium chloride and soyatrimethylammonium chloride; di(hydrogenated tallow) dimethylammonium chloride and ditallowdimethylammonium chloride are preferred. Examples of Component (ii) are methylbis(tallowamidoethyl) (2-hydroxyethyl) ammonium methylsulfate and methylbis(hydrogenated tallowamidoethyl) (2-hydroxyethyl) ammonium methylsulfate wherein R₁ is an acyclic aliphatic C₁₅-C₁₇ hydrocarbon group, R₂ is an ethylene group, R₅ is a methyl group, R₈ is a hydroxyalkyl group and A is a methylsulfate anion; these materials are available from Sherex Chemical Company under the trade names Varisoft (R) 222 and Varisoft (R) 110, respectively. An example of Component (iv) is dimethylstearylbenzylammonium chloride wherein R₄ is an acyclic aliphatic C₁₈ hydrocarbon group, R₅ is a methyl group, and A is a chloride anion, and is sold under the trade names Varisoft (R) SDC by Sherex Chemical Company and Ammonyx® 490 by Onyx Chemical Company. Examples of (v) are 1-methyl-1-tallowamido-ethyl-2-tallowimidazolinium methylsulfate and 1-methyl-1-(hydrogenated tallowamidoethyl)- methylsulfate. The quaternary ammonium compounds are preferably used at levels in the range of from 0,5% to 10%. The ratio (quaternary ammonium salt): (amine) should not exceed 10:1, and preferably does not exceed 2:1. f) Optional silicone Component The compositions herein can optionally contain an aqueous emulsion of a predominantly linear polydialkyl or alkyl, aryl siloxane in which the alkyl groups can have from one to five carbon atoms and may be wholly or partially fluorinated. Suitable silicones are polydimethyl siloxanes having a viscosity at 25°C in the range from 100 to 100,000 centistokes (mm²/s), preferably in the range from 1000 to 12,000 centistokes (mm²/s). The silicone component suitable for use herein is more fully described in British Patent No. 1.549.180. g) Optional nonionics The compositions optionally contain nonionics as have been disclosed for use in softener compositions. Such nonionics and their usage levels, have been disclosed in U.S. Patent 4.454.049, issued June 12,1984 to Mac Gilp et al. Specific examples of nonionics suitable for the compositions herein include glycerol esters (e.g., glycerol monostearate), fatty alcohols (e.g.,stearyl alcohol), and alkoxylated fatty alcohols. The nonionics, if used, are typically used at a level in the range of from 0.5 - 10% by weight of the composition. h) Other Optional Ingredients In order to further improve the stability of the compositions herein, and further adjust their viscosities, the present compositions contain at least 83ppm of electrolyte, CaCl₂. It has been found that the Brookfield viscosities of highly concentrated dispersions can be reduced to less than 100 cps (100 mPaS), using relatively small amounts of CaCl₂ (e g., 600ppm). The compositions herein can optionally contain other ingredients known to be suitable for use in textile softeners. Such adjuvants include perfumes, preservatives, germicides, colorants, dyes, fungicides, stabilizers, brighteners and opacifiers. These adjuvants, if used, are normally added at their conventional levels. However, in the case of composition ingredients utilized for a fabric treatment effect, e.g., perfumes, these materials can be added at higher than normal levels, corresponding to the degree of concentration of the product. EXAMPLE I The following aqueous dispersion was prepared : A melt of the ditallow imidazoline was added to an aqueous solution of the phosphoric acid under high shear mixing. A finely divided dispersion was formed. Calcium chloride was added as an aqueous solution. Perfume was blended in by stirring. The resulting dispersion had a Brookfield viscosity of 15 cps (15 mPaS) and excellent phase stability upon prolonged storage. When added to the rinse cycle of an automatic laundry operation, the composition imparted excellent softness and antistatic properties to the fabrics so treated. EXAMPLE II The following aqueous dispersion was prepared : The dispersion, prepared as described in Example I, had excellent phase stability; the Brookfield viscosity was 80 cps (80 mPaS). Fabrics treated with a 0.2% aqueous bath of the dispersion had excellent softness and anti-static properties. EXAMPLE III - VIII The compositions of examples III through VIII are prepared as follows: The amine (1-tallowamidoethyl-2-tallowimidazoline) was melted and kept at a temperature of 65°C - 80°C, avoiding overheating. A water seat was made, containing electrolyte (CaCl₂), dye, bactericide. The seat was kept at a temperature in the range of from 60°C to 80°C. Acid was added to the water seat. The amount of acid needed is a function of the pKa value of the acid, the product matrix, and the desired final pH of the product. Typically, 0.4% of acid (by weight of the composition) is sufficient to obtain a pH of below 8. Greater amounts of acid result in a proportionately lower pH. The molten amine was then added to the acidified water seat under continuous agitation. The hot product was then trimmed to the desired viscosity by addition of electrolyte. Perfume was added. The product was then cooled under agitation. All compositions were phase stable during 3 months testing at ambient temperature. All samples had a good viscosity behaviour over a wide (4°C - 35°C) temperature range. Examples IX - XII The following compositions are prepared as described for examples III - VII.

Claims: A stable aqueous dispersion comprising : (a) from 1% to 40% by weight of an amine selected from the group consisting of the cyclic amines of the formula : wherein n is 2 or 3; R₁ and R₂ are, independently, a C₈-C₃₀ alkyl or alkenyl radical , Q is CH, CH₂, NH or N. wherein T is NR₅, R₅ being H or C₁-C₄ alkyl, and R₄ is a divalent C₁-C₃ alkylene group or (C₂H₄O)m, wherein m is a number of from 1 to 8; or X is R₄; (b) a dispersing aid selected from the group of Bronstedt acids having a pKa value of not greater than 6; provided that the pH of the dispersion is not greater than 5; and (c) characterized in that it contains at least 83 ppm of Calcium Chloride as a viscosity adjusting agent; and that it is free of compounds of the formula : wherein n represents an integer from 1 to 4, R¹ and R² represent, independently from each other, a methyl or ethyl group, R³ represents hydrogen or a methyl group, R⁴ represents an alkyl group having from 7 to 15 carbon atoms with at least 7 carbon atoms in the main chain, and X⁻ represents the equivalent anion of a water-soluble organic or mineral acid. An aqueous dispersion according to claim 1 comprising from 3% to 35% by weight of the amine. An aqueous dispersion according to claims 1 or 2 having a pH not greater than 4. An aqueous dispersion according to any of the preceding claims wherein the dispersing aid is an acid selected from the group consisting of the inorganic mineral acids and the organic acids of the formula R-COOH or R-CH₂-SO₃H, wherein R is hydrogen or C₁ to C₄ alkyl; and mixtures thereof. An aqueous dispersion according to claim 4 wherein the dispersing aid is selected from the group of HCl, HBr, H₂SO₄, H₂SO₃, H₃PO₄, formic acid, acetic acid, methylsulfonic acid and ethylsulfonic acid. An aqueous dispersion according to any of the preceding claims wherein in the amine component n=2, R₁ and R₂ are, independently, C₁₂-C₂₀ alkyl, and X is -C₂H₄-NH-CO-. An aqueous dispersion according to any of the preceding claims which additionally comprises, preferably from 0.5% to 10% by weight of, a conventional quaternary ammonium softening compound, preferably of the formula wherein R₂ is an acyclic aliphatic c₁₅-c₂₂ hydrocarbon group, R₃ is a C₁-C₄ saturated alkyl or hydroxyalkyl group, R₄ and R₅ are selected from R₂ and R₃; and A is an anion. An aqueous dispersion according to any of the preceding claims, which further comprises an emulsion of a predominently linear di(C₁-C₅) alkyl or C₁-C₅ alkylaryl siloxane in which the alkyl groups may be partially or wholly fluorinated and which may be substituted with cationic nitrogen groups, the siloxane having a viscosity at 25°C of at least 100 centistokes and up to 8000 centistokes (mm²/s); the weight ratio of the siloxane content of the emulsion to the amine component being in the range of from 5:1 to 1:100, preferably 2:1 to 1:10. An aqueous dispersion according to claim 8 wherein the siloxane is a polydimethyl siloxane. An aqueous dispersion according to any of the preceding claims, which further comprises from 0.5% to 10% by weight of a nonionic, preferably a glycerol ester, a fatty alcohol or an alkoxylated fatty alcohol. An aqueous dispersion according to any of the preceding claims wherein the amount of dispersing aid is from 3% to 50%, preferably from 5% to 30%, by weight of the amine. The use of an aqueous dispersion according to claims 5 to 11 as a rinse-added fabric softener.

Inventors: DE BUZZACCARINI, FRANCESCO, KOENIG, AXEL, König, Axel
Applicants: PROCTER & GAMBLE EUROPEAN TECHNICAL CENTER, THE PROCTER & GAMBLE COMPANY
Application year: 1986
Main classification: C11D1
IPC codes: D06M13, C11D3, C11D1, C07D233, D06M15