BG61343B1 - Free-flowing fabric softening composition and process for its manufacture - Google Patents

Abstract

A process of producing a free-flowing spray dried particulate fabric softening composition is provided and comprises the steps of: (a) forming a crutcher slurry containing: - from about 5 to 40%, by weight, of a cationic quaternary ammonium softening compound; - from about 0,5 to 15%, by weight, of an anionic and/or a nonionic detergent compound; - from about 45 to 85%, by weight, of urea, the above percentages being based on the solios content of the slurry, in the absence of water; (b) mixing the crucher slurry formed in (a) to provide a inform mixture or dispersion having an average particle size of less than about 1,0 micron and thereafter; (c) spray drying the aforesaid mixture or dispersion in a spray tower wherein the water content of the mixture is substantially evaporated to provide free-flowing particles of a softening composition capable of being readily dispersed in water.

Description

TECHNICAL FIELD

The invention relates to a flowable, spray-dried, concentrated granular tissue softener that is readily dispersible in water, and to a method for its preparation and use. In particular, the invention relates to an effective tissue softener, in a user-friendly form, capable of containing a relatively large amount of a cationic tissue softener and to be economically packaged and shipped.

BACKGROUND OF THE INVENTION

Fabric softening or conditioning compositions for use in domestic washing machines are known in the United States and Europe. Generally, these compositions are aqueous liquids containing as the main active ingredient a cationic quaternary ammonium compound which gives a softening effect to the tissues treated with it in the washing bath. These tissue softeners (the usual use of such softening compositions) typically contain from about 5 to 8% active cationic softening compound. Because washing machines in the United States contain about 65 l of water, about 90 β 6% active liquid fabric softener is normally added during the rinse cycle to achieve an acceptable softening level.

However, liquid fabric softeners have some drawbacks. The concentration of the active cationic quaternary ammonium compound capable of being introduced into the aqueous system is limited by the solubility properties of the quaternary compound and the stability and ability to pour out the final product. Conventional fabric softener compositions, added upon rinsing, contain quaternary ammonium compounds, typically having two long alkaline chains, essentially water-insoluble materials. Therefore,

6 (343 ·. · ... .. · · · ·. · .....; ·.

the softening compositions are normally in the form of aqueous dispersions or emulsions. As a consequence, at high concentrations of the active, cationic softener compound, 5 mainly above 6% by weight, problems with product preparation, stability / i.e., easy to experience. product separation /, gel formation and water dispersibility. At concentrations above about 9% by weight. of the quaternary ammonium compound, the viscosity and stability of the aqueous liquid softener are often unacceptable for commercial purposes.

There are also economic disadvantages associated with the sale of liquid omega-15 tissue wrappers. They primarily relate to the high cost of packaging and dispatching bottles of a dilute aqueous liquid product containing a relatively low concentration of the active emollient. 20 Packaging also poses environmental problems. The production and supply of plastic containers commonly used for liquid household products are often incompatible with consumer requirements in the US and Europe for the use of recyclable, readily biodegradable packaging materials. There is therefore a need for a granulation softener composition, which can contain relatively high concentrations of active emollients, with the possibility of being delivered in an economical packing form.

In the patent literature, omega 35 tissue powder holders have been described. In the literature (1) a powder fabric softener composed of a defined quaternary ammonium compound in combination with urea is described. (2) A process for the preparation of a tissue softener is described, which comprises reacting urea with a quaternary ammonium compound in the presence of water to give a granular product. Patents of υδ (3 and 4) relate to a process for the preparation of a 45-quaternary powder softener in which a solution of quaternary ammonium compound is sprayed onto a granular carrier such as urea or sodium tripolyphosphate so that granules of 50 carriers having a volume of 50 carriers are obtained from the softener.

Literal references (5) describe fabric softeners containing quaternary2 = ..61343.-.-. ·. · A nerve ammonium compound, urea and calcium soap, such as tall oil calcium soap. The preparation method involves forming a liquid mixture of the desired components, cooling the liquid to form a solid, and then grinding it to form granules. Before grinding, the solid is air-conditioned for several hours, the term "air-conditioning" being used to indicate that the water content of the particles is brought closer to equilibrium with the environment. According to the description, the granules can also be obtained by spray-cooling the liquid mixture, whereby the solid is formed without accompanying loss of water. The resulting solid is then ground and air-conditioned.

Another method (6) is described in which molten particles of a quaternary ammonium compound and a dispersion inhibitor such as fatty alcohol or fatty acid are bonded to a powder-dried detergent base containing a surfactant and a constituent. It is essential in these and in other patents that the dispersion of the cationic softener compound in the wash water is avoided in order to prevent its inactivation in the wash solution. In these patents seeking to create a quaternary ammonium compound in the form of a water-dispersible powder specifically adapted for use in the rinse cycle, problems remain, especially at high concentrations of quaternary compounds.

SUMMARY OF THE INVENTION

It has been found that a highly concentrated granular fabric softener composition can be prepared according to the method of the invention by a spray drying process that provides granules of a softening composition containing up to about 40% cationic softening compound in combination with a nonionic and / or anionic anion active ingredient, among other ingredients, which are easily dispersible in water and provide effective softening.

Accordingly, the invention provides a spray-dried, soft tissue softening, easily dispersible, water-containing composition comprising:

a) from about 5 to 40% by weight a cationic quaternary ammonium softening compound;

b) from about 0.5 to 15% by weight. anionic and / or nonionic detergent compound; and c) from about 45 to 85% by weight. urea, the balance is water.

In a preferred embodiment of the invention, the composition further comprises from 1 to 10% by weight. fatty acid alkanolamide.

The invention also encompasses a process for the preparation of a flowable, granular, 15-spray drying fabric softener composition, readily dispersible in water, comprising:

a / forming a vertically stirred mixture containing:

I / from about 5 to 40% by weight. cationic quaternary ammonium softening compound,

II) from about 0.5 to 15% by weight. anionic and / or nonionic detergent compound,

III / from about 1 to 10% by weight alkaloamide, and

IV / from about 45 to 85% by weight urea, the percentages given being based on the solids content of the mixture in the absence of water;

b) stirring the mixture prepared in step a) to obtain a homogeneous mixture or dispersion with an average particle size of less than 1.0 μ, and then in / spray drying the mixture or dispersion in a spray dryer, at which substantially evaporates the water content of the mixture to give flowable granules of a softening composition, readily dispersible in water.

The invention is based on the fact that a fabric softener composition can be prepared in granular form by spray drying to provide a composition more concentrated than conventional liquid softeners added in the rinse cycle. The resulting spray-dried granules are water-dispersible and provide an effective softening of the tissues in the wash or rinse cycle in the water bath. An essential feature of the composition according to the invention is that it is 20 .61343.

emit homogeneous, spray-dried granules using a stirring step immediately before the spray-drying of the mixture so that the content of the mixture is dispersed very well to form a mixture or dispersion with an average particle size of less than 1.0 μ. Homogeneous mixtures of this type can be achieved with different types of mixers, mills or pumps known to those skilled in the art, but it is preferable to use so-called. A "homogenizer", such as that manufactured by Golin Corporation, Everett, Massachusetts, USA or Hilversum, the Netherlands, which consists of a production pump connected to a homogenizing valve device capable of providing an intimate mixture with an average particle diameter, less than 1.0 μ, and more preferably less than 0.75 μ. The most preferred maximum particle size of such a mixture is less than 5.0 μ and even more preferably less than 3.0 μ.

The pulverizing process of the softening composition according to the invention utilizes for the most part a well-known technology for the production of granulated detergent compositions. Generally, a vertically stirred boiler mixture is prepared comprising a mixture of water with many or most of the ingredients desired for the fabric softener composition. The solids content of the mixture is generally from about 20% to about 70%, preferably 30% to 60% and most preferably from 40% to 50% thereof, with the balance being water.

The mixture is then triturated by pumping into a pressure nozzle of 1000 to 2000 ρδΐ in a spray drying tower, with typical dimensions of commercialized towers being about 35-100 feet high and about 12 to 30 feet in diameter. Air at a temperature of about 300-1000T is introduced into the base of the tower, which contacts the spray mixture to provide hot drying gas for the droplets of the mixture, evaporating most of the water. The resulting pellets or spheres are collected at the bottom of the tower, leaving moisture and heated air from the top. Ingredients that are sensitive to heat or moisture, such as perfumes, may then be added to the granules in the tower in subsequent blending or grinding operations.

The mixture is preferably prepared by sequentially adding various components in such a way as to result in the best stirred and pumpable spray drying mixture. The order of addition of the various ingredients may be varied depending on the circumstances. It is normally preferable to add all or substantially all of the water to the mixture, preferably at the temperature of the process, after which the other components, namely the urea, the quaternary ammonium softener, the anionic and / or non-ionic surfactant, the alkali surfactant, are added sequentially. of fatty acid and optional additives such as pigments, antioxidants and antimicrobials.

The temperature of the aqueous medium in the mixture is typically from about room temperature or elevated, typically in the range of 20 to 70 ° C and preferably from about 25 to 40 ° C.

The stirring time of the mixture to obtain a carefully mixed, homogeneous mixture varies widely from less than 5 ιηΐη for small mixtures and for mixtures with high water content to more than 1 b in some cases, although 30 πιϊη is the preferred upper limit. After stirring in the mixer, the mixture is transferred for further stirring into a "homogenizer" or similar mixer or pump to obtain a uniform dispersion or mixture described above having an average particle size of less than 1 μ.

The resulting dispersion is then transferred in the usual way to the tower of a spray dryer, which is located near the mixer. The dispersion is passed under high pressure through the spray nozzles in the spray tower (countercurrent or in one direction with the current), whereby the droplets of the mixture fall through the hot drying gas, forming pellets or spheres of the fabric softening composition upon almost complete evaporation of the tissue. the water. The moisture content of the granules is preferably about 2 to 4% by weight.

The cationic quaternary ammonium softening compound useful for the invention 4,61343, may include imidazoline salts, quaternary ammonium salts with two long alkyd chains and diesterified, long-chain fatty acid dinisalkyl quaternary ammonium quaternary.

The general structure of the preferred imidazoline salts is the following:

1.With a dream,

I I uf '·

Κι as R [is C ₈ to C _zo aliphatic radical and preferably a C ₁₄ to C ₁₈ alkyl or alkenyl; 1%, and K ₃ independently of each other may be any of E _p is lower alkyl or substituted alkyl of C, to C ₄ such as haloalkyl, hydroxyalkyl, acylaminoalkyl and the like; X is a water-solubilizing anion such as chloride, bromide, iodide, fluoride, sulfate, methosulfate, nitrite, nitrate, phosphate and carboxylate (eg acetate, adipate, phthalate, benzoate, oleate and others);

Typical imidazoline softening compounds include:

2- hepatadecyl-1-methyl-1-oleylamidoethyl imidazoline ethosulfate,

2-heptadecyl-1-methyl-1- (2-sterolamido) ethyl-imidazoline sulfate,

2-heptadecyl-1-methyl-1- (2-sterolamido) ethyl-imidazoline chloride,

2-coco-1- (2-hydroxyethyl) -1-benzyl imidazoline chloride,

2-coco-1 (hydroxyethyl) -1- (4-chlorobutyl) imidazoline chloride,

2-coco-1- (2-hydroxymethyl) -1-octadecenyl imidazoline chloride,

2-tallow fat -1- (2-hydroxyethyl) -1-benzyl imidazoline chloride,

2-tallow fat -1- (2-hydroxyethyl) -1- (4-chlorobutyl) -imidazoline chloride,

2-heptadecenyl-1 -2-hydroxyethyl (-1-) -4-chlorobutyl-imidazoline chloride,

2-heptadecenyl-1- (2-hydroxyethyl) -1-benzyl imidazoline chloride,

2-Heptadecyl-1- (hydroxyethyl) -1-octadecyl imidazoline ethyl sulfate.

The general structure of quaternary ammonium salts with two long-chain alkyl is the following:

-ΝI κ

as E groups are chosen from aliphatic C, to C _zo, preferably alkyl or alkenyl; aryl (e.g. phenyl, toluyl, cumyl and the like (aralkyl) e.g. benzyl, phenethyl, methyl10 benzyl and the like); and halo, amide, hydroxyethyl and carboxyl substituents of the same as halo C ₂ to C ₆ alkyl (e.g. 2-chloroethyl); and hydroxy C ₂ to C ₆ alkyl, (e.g. 2-hydroxyethyl); under the prerequisite 15 you have at least two K being C ₁ to C ₂ and preferably C ₁₂ to C ₂₂ and the others being lower alkyl with C to C ₄ (and most preferably methyl or ethyl) and an anion thereof. , as defined for X in Formula 1.

Typical quaternary ammonium salts of formula 2 are as follows: distearyl dimethyl ammonium chloride; dimethylammonium ammonium chloride; dihexadecyl dimethyl ammonium chloride; distearyl dimethyl ammonium bromide, di / hydrogenated tall oil / dimethyl ammonium bromide; distearyl di / isopropyl / ammonium chloride; distearyl dimethyl ammonium methosulfate; di / hydrogenated tall oil / dimethyl ammonium methosulfate.

Another preferred class of cationic fabric softeners are quaternary ammonium salts with two lower alkyl and two esterified long-chain fatty acids and quaternary ammonium salts with lower alkyl, lower hydroxyalkyl and two esterified long-chain fatty acids. This class of cationic fabric softeners may be represented by the general formula o

I

K4OSC 0

I ι

K, —Ν —K ₄ USC

I

K 1 in which ESO is the fatty acid residue having 12 to 24 carbon atoms;

and are independently a lower alkyl group or a hydroxyalkyl group having 1 to 4 carbon atoms and preferably 1 to 3 carbon50 native atoms; E ₄ is a lower alkylene group having 1 to 4 carbon atoms, preferably 1 to .61343 and most preferably 2 carbon atoms, i.e. K ₄ is -CH ₂ CH ₂ and X is a water solubilizing anion as defined above. Such compounds are commercially available, for example, from Stepan Chemical Co. under the trademark Stepantex, such as Stepantex UNK 90, which has the formula

CH.CH, OOSK

I

CH ₃ - N -CH ₂ CH ₂ CH ₂ I OOSK.H CH ₂ one in which CSR are derived from tallow or coconut oil fatty acids and X may be chloride or sulfate.

In the granular softening composition, the quaternary ammonium softening compound is generally from about 5 to 40% by weight. preferably from about 10 to 30% and most preferably from about 15 to 25% by weight.

An optional fabric softener is a fatty alcohol in which the hydrophobic group may be a straight or branched alkyl group or an alkenyl group having from about 10 to 24, preferably from about 10 to 20, more preferably from about 12 to 20 carbon atoms. Specific examples of fatty alcohols include decanol, dodecanol, tetradecanol, pentadecanol, hexadecanol, octadecanol, lauryl alcohol, palmityl alcohol, stearyl alcohol, oleyl alcohol and mixtures thereof. Furthermore, the fatty alcohol may be of natural or synthetic origin and may include, for example, mixed alcohol, such as C ₁₆ to _{C] 8} alcohols prepared by Ziegler polymerization of ethylene.

The fatty alcohol may be contained in the composition in a minimal amount relative to the cationic fabric softener so that the weight ratio of the cationic fabric softener to the fatty alcohol is in the range of about 6: 1 to 2: 1, especially preferably from about 5 : 1 to 3: 1.

The fatty acid alkanolamides useful according to the invention are those derived from fatty acid amides whose alkyl radical contains at least 12 carbon atoms. Preferably they have the general formula / ^H

K - C - ν '

H X 2 in which η is 2 or 3. The preferred material is coco monoethanolamide.

The concentration of the fatty acid alkanolamide in the softening composition is generally from about 1 to 10% by weight. and preferably from about 1 to 5% by weight. The combination of fatty acid alkanolamide and quaternary ammonium emollient according to the invention provides a superior softening effect on the tissues.

An essential component of the fabric softener composition is urea. The granules generally contain from about 45 to 85% by weight. urea, preferably from about 55 to 75% and most preferably from about 60 to 70% by weight.

Another important ingredient to improve the solubility and dispersion of the granules is the anionic and / or non-ionic surfactant. Among the anionic surfactants useful for the present invention are those surfactants that contain an organic hydrophobic group of about 8 to 26 carbon atoms and preferably of about 10 to 18 carbon atoms in their molecular structure and at least one water solubilizing group selected from the group of sulfonate, sulfate, carboxylate, phosphate and phosphate so as to form a water-soluble detergent.

Examples of suitable anionic detergents include soaps, such as water-soluble salts (e.g., sodium, potassium, ammonium and alkanolammonium salts) of higher fatty acids or resin salts containing from about 8 to 20 carbon atoms and preferably 10 to 18 carbon atoms. Particularly useful are the sodium and potassium salts of fatty acids and fatty acid mixtures derived from coconut and tall oil, for example sodium coconut oil soap and tall oil potassium soap.

The anionic class of detergents also includes water-soluble sulfated and sulfonated detergents having an aliphatic, preferably an alkyl radical containing from about 8 to 26 and preferably from about 12 to 22 carbon atoms. Examples of sulfonated anionic detergents are the higher alkyl aromatic sulfonates, such as the higher alkylbenzene sulfonates containing from about 10 to 16 carbon atoms in the higher alkyl group in the moiety.

61343 ..

or branched chain, such as the sodium, potassium and ammonium salts of higher alkylbenzene sulfonates, higher alkyl toluene sulfonates and higher alkyl phenolenes.

Other suitable anionic detergents are oleinsulfonates, including long-chain alkenesulfonates, long-chain hydroxy-sulfonates, or mixtures of alkenesulfonates and hydroxy-alkanesulfonates.

Other suitable anionic detergents are sulfated ethoxylated higher fatty alcohols of the formula KO / C ₂ H ₂ O / _w 80 ₃ M, where K is a fatty alkyl of from 10 to 18 carbon atoms, w is from 2 to 6 / preferably having a value of about 1/5 to 1/2 of the number of carbon atoms in K / and M is a solubilizing salt-forming cation such as an alkali metal, ammonium, lower alkyl amino or lower alkanolamine or higher alkyl benzenesulfonate, with higher alkyl having 10 to 15 carbon atoms. The ratio of ethylene oxide to polyethoxylated higher alkanosulfates is preferably 2 to 5 to 1 ethylene oxide groups per ton anionic detergent, most preferably 3 to 1, especially when the higher alkanol has 11 to 15 carbon atoms. A preferred polyethoxylated alcohol choleulfate detergent is marketed by Shell Chemicals under the name Neodol 25-35.

The most preferred water-soluble anionic detergent compounds are ammonium and substituted ammonium (ato mono-, di- and tri-ethanolamine), alkanometallic (such as calcium and magnesium) salts of higher alkyl benzenesulfonates, olefin sulfonates. Most preferred among the anions listed are sodium linear alkyl benzenesulfonate (LABS), and in particular those in which the alkyl group is a straight chain alkyl radical of 12 to 13 carbon atoms.

Among the suitable nonionic surfactants are ethoxylated fatty alcohols having 12 to 20 carbon atoms and an average degree of ethoxylation of 3 to 9. Preferred nonionic detergents are coconut alcohols having an average of 6 or 7 ethoxy groups per molecule and _C - C ₁₃ primary alcohols with 6 or 7 ethoxy groups of it1 of high fat alcohol. Ethoxylated lauryl alcohol containing about 7 to 1 ethoxylate per to1 alcohol is particularly preferred for use in the invention.

Other useful non-ionic detergent compounds include alkylpolyglycoside and alkylpolysaccharide surfactants, which are well known to those skilled in the art.

The amount of anionic surfactant in the granular composition may vary from 0 to 8% and preferably varies with the percentage of the cationic softener as follows: from about 1 to 4% of the anionic surfactant when the percentage of cationic compound is low from about 20% and from 3 to 8% anionic surfactant when the percentage of the cationic softener is from about 20 to 40%, all percentages by weight relative to the granular composition. In general, the concentration of the anionic surfactant is 2 to 4% by weight. The nonionic surfactant is optionally contained in about 0.5 to 5% by weight. and preferably not more than 1% by weight.

Fabric softeners according to the invention may further comprise additive and complementary ingredients which should not adversely affect the stability or functional characteristics of the softening composition. Such complementary ingredients include perfumes, colorants, pigments, antimicrobials, stain removers, tissue cardigans, antioxidants and anti-corrosion agents.

EXAMPLES FOR IMPLEMENTATION

Example 1. A granular fabric softener composition according to the invention has the following content:

Ingredients in% wt. OSBMAS ¹ 24 Non-ionic surface active substance ² 2 Sodium dodecyl benzenesulfonate 3 Cocomonoethanolamide 3 Carbamide 64 Moisture balance

- · 61343 ·· · '

1- Distearyl dimethyl ammonium chloride

- Ethoxylated lauryl alcohol having about 7 to 1 ethoxylate per sho1 alcohol

Ten-and-a-half / 10.5 / lb of the fabric softener composition described above was added to a fully loaded washing machine in a rinse cycle at a water temperature of 25 ° C and a water hardness of 100 and 320 ppm. The time to disperse the granular product in water is about 1.5 πιΐη.

The softness and hydrophilicity of the resulting tissues was measured and compared with the measured softness of the tissues treated in the same washing machine with a commercially available 42 lb. liquid fabric softener containing 6% quaternary ammonium softener. Tissues treated with the granular fabric softener composition according to the invention exhibit greater softness when measured and are more hydrophilic than those treated with commercially available liquid product.

Claims (7)

Claims CLAIMS 1. A method of producing a spray-dried powder composition for softening tissues, readily dispersible in water, characterized in that a vertically stirred mixture containing from 5 to 40% by weight is formed. a cationic quaternary ammonium softening compound; from 0.5 to 15% by weight anionic and / or non-ionic detergent; from 45 to 85% by weight urea, the processes being based on the solids content of the mixture in the absence of water; the formed vertically stirred mixture is stirred to obtain a homogeneous mixture or dispersion having an average particle size of less than 1.0 μ, and then subjected to drying by spraying the mixture or dispersion in a spray dryer, where the water content of the mixture is essentially evaporated to give granules of a softening composition which are readily dispersible in water. 5 A method according to claim 1, characterized in that the mixture further contains from 1 to 10% fatty acid alkanolamide. The method of claim 1, wherein the alkanoamide is 10 cocomonoethanolamide. A method according to claim 1, characterized in that the mixture contains from 1 to 8% anionic detergent and from 10 to 40% cationic softening agent, the percentages being 15 are based on the solids content of the mixture. 5. The method according to claim 1, wherein the mixture contains up to 2% by weight non-ionic detergent. Method according to claim 1, characterized in that the amount of anionic detergent in the mixture varies with the percentage of the cationic compound as follows: from 1 to 4% anionic detergent when the percentage of the cationic softener is less than 20%, and from 3 up to 8% anionic detergent when the percentage of the cationic softener is from 20 to 40%. 7. The method of claim 1, wherein the cationic softener is distearyl dimethyl ammonium chloride.