MXPA99009500A - Stable rinse cycle fabric softener composition with glycerol monostearate co-softener - Google Patents

Abstract

Rinse cycle fabric softeners are described which are stable and pourable and which contain a quaternary diester fabric softener such as N-methyl, N,N,N-triethanolamine ditallowester quaternary ammonium salt in combination with glycerol monostearate and a fatty alcohol ethoxylate nonionic surfactant as the emulsifier having an HLB value above 7.5.

Description

STAINLESS STEEL RUBBER FABRIC SOFTENING COMPOSITION WITH GLYCEROL MONOESTEARATE CO-SOFTENER Field of the Invention This invention relates to liquid fabric softening compositions intended for use in the rinse cycle of an automatic fabric washing machine and for manual use. More particularly, this invention relates to aqueous fabric softening compositions which provide improved softness to fabrics concomitantly with the stability of the improved product as manifested by properties such as uniform viscosity over a wide range of temperature and avoiding separation. of phase.

Compositions containing quaternary ammonium salts are commonly used to provide fabric softening benefits when used in a laundry rinsing operation. Numerous patents have been issued for these types of compositions and compounds.

More recently, however, in view of concerns for the environmental safety (eg, biodegradability) of quaternary ammonium compound softeners, there have been many proposals for a partial or total replacement of the conventional quat fabric softener. which are exemplified by dimethyl distearyl ammonium chloride. { or saybo).

For example, in U.S. Patent No. 5,133,885 issued to L. Contor et al. (Corresponding to European Patent 0423894, both assigned to Colgate-Palmolive Company, the assignee of the present invention), the fabrics are described which are aqueous dispersions of a fatty acid ester quat of the formula: wherein one or two groups represent an aliphatic ester residue of from 12 to 30 carbon atoms and the remaining R groups represent the lower aliphatic aryl or hydroxyalkyl groups, X "is an anion and" a "represents the ionic valence of the anion and a fatty acid amidoamine softener of the formula: R1CONH (CH2) raN-R3 I R2 wherein R1 is a C12 to C30 alkyl or alkenyl group, R2 represents R ^ R ^ ONrUCH ^ ,. or CH2CH2OH; R3 represents hydrogen, methyl or (CH2CH20) pH, m is a number from 1 to 5 and p is a number from 1 to 5, in a ratio by weight of quat ester to amine amine of from 10: 1 to 1:10.

The patent of the United States of America No. 4,844,823 issued to Jacques et al. Describes fabric softening compositions wherein a preferred class of softeners are the diesterified long chain fatty acid quaternary ammonium compounds.

Glycerol monostearate (GMS) is a known emulsifier for the aforementioned esterified quaternary ammonium softeners, commonly referred to as "ester quat" softeners. U.S. Patent No. 5,066,414 issued to Chang discloses fabric softening compositions containing a quat ester which is a mono or di ester variation of dimethyl ammonium chloride dikebo (DTDMAC) in combination with glycerol monostearate and alkoxylated alcohol selected linear of the condensation products of linear Cß-Clß fatty alcohols with from 1 to about 10 moles of ethylene oxide.

U.S. Patent No. 5,545,350 issued to Baker et al. Discloses fabric softening compositions comprising a diester quaternary ammonium compound optionally further containing a nonionic softener such as a sorbitan ester as an additional softening agent. In column 13, lines 22-24, the owner of the patent indicates that "glycerol monostearate has a low lipophilic hydrophilic balance that has a detrimental effect on the stability of the compositions". In addition, in column 14, lines 65-67, the patent owner declares that "the compositions of the present invention are essentially free of glycerol monostearate (GMS)". The reason provided is that the low hydrophilic lipophilic balance of the GMS causes phase separation and / or stability problems in the compositions described in the patent.

Despite previous art descriptions directed to the combination of diester quaternary ammonium compound softeners with a co-softener there is still a need to deliver improved softness to a diester quat softening composition without adversely affecting the stability and viscosity of the product.

Synthesis of the Invention In accordance with the present invention there is provided a stable and pourable water dispersible fabric softener composition comprising: (a) from about 1% to about 25% by weight of a combination of fabric softening components (A) and (B) wherein (A) is a biodegradable fatty ester quaternary ammonium compound of the formula (A) I): wherein each R4 independently represents an aliphatic hydrocarbon group having from about 8 to 22 carbon atoms, R 5 represents (CH 2) 6-R 7 wherein R 7 represents an alkoxycarbonyl group containing from 8 to 22 carbon atoms, benzyl, phenyl, substituted phenyl of (C 1 -C 5 alkyl, 0 H or H; R6 represents (CH2) wherein RB represents benzyl, phenyl, substituted phenyl of alkyl (Cx-C4), OH or H; q, r, s and t each independently represent a number from 1 to 3; and x is an anion of a valence a; and (B) is glycerol monostearate. (b) an effective amount of an emulsifier 15 comprising a nonionic fatty alcohol ethoxylate surfactant having a hydrophilic-lipophilic balance (HLB) value greater than about 7.5 as measured by the Group number method Davies; Y (c) an aqueous solvent, said fabric softening composition is free of inorganic mineral • acid and organic acid.

The present invention also provides a method for imparting softness to fabrics by contacting the fabrics with an effective softening amount of the fabric softening composition of the invention, generally and preferably, in the rinsing cycle of a washing machine. of automatic clothing.

The present invention is predicated on the discovery that glycerol monostearate (GMS) can be effectively used as a co-softener in conjunction with a quaternary ammonium diester compound as described herein without adversely affecting the viscosity and stability of the product in General with the proviso that an emulsifier is selected according to the invention having a hydrophilic-lipophilic value of greater than 7.5. The hydrophilic-lipophilic balance value is calculated for the purposes of the present invention using Davies group number values as described in Proceedings Second International Congress on Surface Activity, Butterworths, London (1957). According to this calculation method, a hydrophilic-lipophilic balance value of 7 means that a surfactant has the same affinity for the aqueous as for the oily phase. The negative values are assigned to the lipophilic groups in the molecule and the positive values to the hydrophilic groups. The hydrophilic-lipophilic value of a given surfactant is calculated by adding to the number 7 the sum of the values positives representing the hydrophilic groups and by subtracting the negative values representing the hydrophobic groups.

For example, the non-ionic fatty alcohol ethoxylate surfactant which is used as the emulsifier in the composition of the invention has the following Davies group number values assigned for the groups present in the surfactant molecule: Value Group - CH2 - - 0. 475 - CH3 - - 0. 475 - (CH2 -CH2-0) - +0. 33 - O - + 1. 3 By way of illustration, the lipophilic hydrophilic balance of a nonionic surfactant emulsifier useful herein, C13-C1S EO 20: 1, is calculated as shown below. This non-ionic surfactant is a fatty alcohol having an average of 13 to 15 carbon atoms ethoxylated with 20 moles of ethylene oxide per mole of alcohol.

For purposes of simplicity the length of the alkyl chain is averaged at C14. The resulting molecule is then composed of the following groups: 1 CH3-; 13 -CH2-; 1 - O-, • and 20 - (CH2 - CH2 -O) - Based on the above, the lipophilic hydrophilic balance is calculated as follows: HLB = 7 + [1 X (-.475)] + [13X (-. 475)] + [lX (1.3)] + [20X (0.33)] HLB = 8.25 Detailed description of the invention The main softening compound according to the invention is the fatty ester quaternary ammonium compound having the following formula: Each R4 independently represents an aliphatic hydrocarbon group having from 8 to 22 carbon atoms, and preferably 14 to 18 carbon atoms. R5 represents the group (CH2) 6-R7 which, depending on R7, can represent a group of long-chain alkyl ester (R7 = C8-C22 alkoxycarbonyl) in which case the compounds of the formula (I) are compounds of quaternary ammonium triester. R6 represents (CH2) tRβ as defined above.

Preferably, however, the fatty quaternary ester compounds are diester compounds, for example R7 represents benzyl, phenyl, phenyl substituted by substituted alkyl C! -C4, hydroxyl (OH) or hydrogen (H). More preferably, R7 represents OH or H, especially and preferably OH, for example R5 is hydroxyethyl. q, r, s and t each independently represent a number from 1 to 3.

X represents a counter anion of a valence such as Cl ", Br", CH30S03", CH3CH2OS03", and the like. For example, the diester quat of the formula (II) can be a compound of the formula: SW wherein each R4 can be, for example, derived from soft or hard bait, coconut, stearyl, oleyl and the like. Such compounds are commonly available, for example, as Tetranyl AT-75 from Kao Corporation of Japan, which is a methyl sulfate of quaternary ammonium amine, triethanoyl ester, dikebo. The Tetranyl AT-75 is based on a mixture of about 25% hard bait and about 75% soft bait. Therefore, this product contains about 34% unsaturated alkyl chains. A second example would be Hipochem X-89107 from High Point Chemical Corporation, which is an analogue of tetranil AT-75 with about 100% saturation in the bait halves. However, in general the quaternary ammonium ester compound of the formula (III) can contain from about 5% to about 75% unsaturated alkyl groups (long chain).

Glycerol monostat (GMS) is the co-softener used in combination with the fatty ester quaternary ammonium compound softener described above. The fatty quat ester range in the composition will generally vary from about 1% to about 20% by weight of the composition; preferably a range of from about 1% to about 12%; and more preferably a range of from about 2% to about 10% by weight. The amount of glycerol monostearate in the composition will vary from about 0.1% to about 8%, by weight; preferably from about 0.5% to about 8% by weight and more preferably from about 0.5% to about 5% by weight.

The emulsifier used in the present fabric softening composition is required to stabilize the composition and avoid phase separation and / or unstable viscosity over a period of at least several months or over a range of temperatures where such composition will be destabilized otherwise by the presence of the glycerol mono-stearate in the composition in the absence of such an emulsifier. The fatty alcohol ethoxylates useful in the invention correspond to the condensation products of ethylene oxide of higher fatty alcohols, with the higher fatty alcohol being from about 9 to 15 carbon atoms and the number of ethylene oxide groups per mole being from about 10 to 30. In the preferred fatty alcohol ethoxylates to be used here, the alkyl chain lengths range from about 13 to 15 carbon atoms and the number of ethylene groups vary from about 15 to 20 per mole. Especially preferred for use herein is Synperonic A20 manufactured by ICI Chemicals, such as the nonionic surfactant having a C13-C15 fatty alcohol ethoxylated with 20 moles of ethylene oxide per mole of alcohol and having a lipophilic hydrophilic balance of 8.25.In general, the hydrophilic-lipophilic balance of fatty alcohol ethoxylates is from about 7.5 to around 10, with the range of hydrophilic-lipophilic balance from about 8 to about 9 being preferred. These are used in the composition in an amount sufficient to provide emulsification, typically from about 1 to 5% by weight of the composition.

The compositions of this invention are provided as aqueous dispersions in which the fabric softening compounds are present in a finely divided form stably dispersible in the aqueous phase. Generally the particle sizes of the dispersed particles of less than about 25 microns (μm), preferably less than 20 μm especially and preferably of not more than 10 μm, on average are acceptable for both softening and stabilization in that the Particle sizes can be maintained during actual use, typically in the rinse cycle of an automatic laundry washing machine.

The aqueous phase of the dispersion is primarily water, usually deionized or distilled water. Small amounts (for example up to about 5% by weight) of co-solvent may be present for the adjustment of the viscosity. Typically, as the cosolvent mono and polyhydroxy lower alcohols will be used, generally in amounts of up to about 5% by weight of the composition. The alcohols Preferred and aqueous are those having from 2 to 4 carbon atoms, such as, for example, ethanol, propanol, isopropanol and propylene glycol or ethylene glycol. Isopropyl alcohol (2-propanol) is especially preferred. However, co-solvents are not required and are generally avoided.

The compositions of this invention include an electrolyte to reduce the viscosity of the dispersion. Generally any alkali metals or alkaline earth metal salts of mineral acids can be used as an electrolyte. In view of the availability, solubility and low toxicity, NaCl, CaCl 2, MgCl 2 and MgSO 4 and similar alkaline earth and alkali metal salts are preferred, and CaCl 2 is especially preferred. The amount of electrolyte will be selected to ensure that the composition does not form a gel. Generally, amounts of electrolyte salt of from about 0.05 to 2.0% by weight, preferably 0.1 to 1.5% by weight, especially preferably from 0.25 to 1.4% by weight will effectively prevent gelation from occurring.

The fabric softening compositions of the invention are formulated to be free of an inorganic mineral acid as well as an organic acid because the presence of such acidic ingredients can affect adversely the desired rheology and / or the stability of the resulting composition.

The optional components commonly used in fabric softening compositions may be added in minor amounts to increase their appearance or performance properties of the liquid fabric softening compositions of this invention. Typical components of this type include, but are not limited to dyes, for example dyes, pigments, rheology modifiers, color protection agents, stain protection agents, preservatives, germicides and perfumes.

The final product, either in concentrated or diluted form can be easily pourable by the end user.

Generally, therefore, the final product viscosity (for a freshly prepared sample) should not exceed about 400 centipoise, preferably not more than 300 centipoise, but should not be so low, for example not less than about 50 centipoise . The preferred viscosity for the concentrate product of the invention is in the range of 120 to 300 centipoise. As used herein, unless otherwise specified, the viscosity is measured at 25 ° C (22-26 ° C) using a Brookfield RVT digital viscometer with a No. 2 spindle at 50 revolutions per minute.

Example 1 A method of preparing compositions of the invention (Composition D) is described below.

Composition D Composition Percent by weight quaternary amine methyl ammonium sulfate triethanol ester dikebo 7.33 Glycerol monostearate 1.38 Alcohol C13-C15 EO 20: 1 0.6 Dequest 2000a) 0.1 Dye 0.002 Calcium Chloride 0.05 to 0.5 (as necessary for viscosity) Perfume 0.2-0.8 Water Rest U) A phosphonate sequestering agent marketed by Monsanto Chemical Company.

The water was heated to 60 ° C and then the dye, the Dequest sequestrant and the non-ionic emulsifier were dissolved in the heated water to form a first part.

In a second container, the diester quat softener and the glycerol mono-stearate were melted and mixed with a mixer at 60 ° C. The resulting homogenous mixture was then dispersed under stirring in a first part described above. The mixing was maintained for about 10 minutes until a homogeneous emulsion formed. The resulting emulsion was allowed to cool to 25 ° C while stirring was maintained.

To the cooled emulsion, the perfume was added under agitation. The viscosity of the softener was then adjusted to between 100 to 200 centipoise by the addition of calcium chloride.

Example 2 To demonstrate the significance in relation to the product stability of using an emulsifier according to the invention against using emulsifiers described in the prior art for use with quaternary ammonium softeners, the following aging tests were carried out.

Three softening compositions were prepared as described in Example 1 based on quat diester and GMS and compositions A, B and C were designated.

Composition A is in accordance with the invention and contained Synperonic A20 as the emulsifier; Composition B is a comparative composition which contained as the emulsifier a fatty alcohol ethoxylate C 16 -C 18 fatty alcohol with 19 moles of ethylene oxide and having a lipophilic hydrophilic balance value of 6.5. Composition C is a comparative composition which contained as the emulsifier a C12-C13 fatty alcohol fatty alcohol ethoxylate with 3 moles of ethylene oxide having a lipophilic hydrophilic balance value of 1.81.

The three compositions were prepared as described above and the viscosity was measured directly after making it; after a day, and after 6 weeks at temperatures from 4 ° C, the ambient temperature to 35 ° C; and 43 ° C. The results are shown in Table 2.

As shown in Table 2, only the composition A according to the invention remained stable, below 300 centipoise, after 6 weeks of aging at 43 ° C. Compositions B and C were unacceptable due to instability.

Example 3 To demonstrate the significance of the value of the lipophilic hydrophilic balance of the emulsifier in relation to the stability of a quat diester and GMS composition as shown in Table 1 of Example 2, 6 compositions were prepared by varying only in the particular selected emulsifier. The aging was carried out for 6 weeks at a temperature of 35 ° C.

The emulsifiers used in each of the 6 tested compositions are described below in Table 3 which provides the lipophilic hydrophilic balance value and the resulting stability of the compositions at the conclusion of the aging test.

Claims (8)

R E I V I ND I C A C I O N S

1. A stable water dispersible liquid pourable fabric softener composition comprising: (a) from about 1% to about 25% by weight of a combination of fabric softening components (A) and (B) wherein (A) is a biodegradable fatty ester quaternary ammonium compound of the formula (A) I): wherein each R4 independently represents an aliphatic hydrocarbon group having from 8 to 22 carbon atoms, R5 represents (CH2) 6-R7 wherein R7 represents an alkoxycarbonyl group containing from 8 to 22 carbon atoms, benzyl, phenyl, substituted phenyl of (Cx-C4) alkyl, OH or H; R € represents (CH2) wherein R8 represents benzyl, phenyl, substituted phenyl of alkyl (C ^ C, OH or H; q, r, syt each independently represent a number from 1 to 3; and x is an anion of a valence a, and (B) is glycerol monostearate. (b) an effective amount of an emulsifier comprising a nonionic fatty alcohol ethoxylate surfactant having a hydrophilic-lipophilic balance (HLB) value greater than about 7.5 as measured by the Davies Group number method; Y (c) an aqueous solvent, said fabric softening composition is free of inorganic mineral acid and organic acid.

2. A fabric softening composition, as claimed in clause 1, characterized in that the Fatty ester quaternary ammonium compound (A) is of the formula:

3. A fabric softening composition, as claimed in clause 2, characterized in that the quaternary ammonium diester compound is N-methyl-N, N, N-triethanolamine dike quaternary ammonium methosulfate.

4. A fabric softening composition, as claimed in clause 1, characterized in that said emulsifier is a C13-C15 fatty alcohol ethoxylated with 20 moles of ethoxylation per mole of alcohol.

5. A fabric softening composition, as claimed in clause 1, characterized in that the amount of component (A) in the composition is from about 1% to about 20%, by weight, and the amount of component ( B) is from about 0.1% to about 8% by weight.

6. A method for imparting softness to fabrics comprising contacting the fabrics with an effective amount of the fabric softening composition, as claimed in clause 1.

7. The method, as claimed in clause 6, characterized in that said fabrics are contacted during the rinsing cycle of an automatic laundry washing machine.

8. The method, as claimed in clause 6, characterized in that said fabrics are contacted during hand washing or rinsing. SUMMARIZES Rinse cycle fabric softeners are described which are stable and pourable and which contain a quaternary diester fabric softener such as N-methyl-N, N, N-triethanolamine, esterbo quaternary ammonium salt in combination with glycerol monostearate and nonionic surfactant fatty alcohol ethoxylate as an emulsifier having a lipophilic hydrophilic balance value above 7.5