IE58103B1 - Dispersible fabric softeners - Google Patents

Abstract

Amines and phosphate esters are combined in substoichiometric amounts to provide water-insoluble, water-dispersible fiber and fabric softeners. The softeners are formulated in a variety of laundry and shampoo compositions.

Description

The present invention relates to means of treating fibers and fabrics, wherein a sub-stoichiometric complex of amines and phosphate esters is used to provide softness and anti-static benefits. Detergent compositions containing said amine-phosphate ester softeners are disclosed. The compositions herein can be used to soften fabrics.

The use of softeners to treat fabrics after a washing operation is a well-known laundering practice. Fabric softeners are, in the main, water-insoluble cationic materials that 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 fabric washing and softening could be done concurrently. Laundering methods employing clay softeners, mixtures of clays and various amine materials and the like, are described in DE-A- 29 64 114, 28 57 163, 24 39 541, 34 899 and EP-A- 23367, 26528 and 28432.

The use of mixtures of amines and soaps (salt of fatty acids) as through-the-wash softeners is disclosed in U.K. Patent 1, 514, 276.

The prior art also discribes the use of various cationic materials in sheet form. See U.S. Patent 4, 220, 562.

The prior art also teaches the softener use of alkyl phosphonate and quaternary ammonium compounds EF-A-0 006 268, filed June 11, 1979.

The prior art also teaches various mixtures of phosphate esters in detergents with fabric softening action - BE-A.-802,679 .

The present invention employs amine-phosphate ester softeners in laundry compositions to provide cleaning and softening concurrently. The softeners herein provide softening and anti-static benefits, especially when used with clay softeners. Importantly, the use of phosphate esters in sub-stoichiometric quantities with the amines in the manner disclosed herein advantageously enhances deposition of the amines on fabrics by as much as 1.5- or 2-fold, as compared with prior art amine fabric softening compositions .

The present invention encompasses a method for softening fabrics by contacting same with sub-stoichiometric, water-insoluble, water-dispersible complexes of amine and phosphate ester (as described more fully, hereinafter) in the presence of water. The method can be carried out. for example, by tumbling damp fabrics with said complexes in a hot air clothes dryer. In another mode, said complexes can be used in an aqueous rinse bath, for example in a laundry rinse. In still another mode, the method can be carried-out concurrently with a fabric cleansing treatment, for example in a detergent-containing laundry liquor, to soften fabrics.

The invention also encompasses detergent compositions (preferably granular) which may be described succinctly as containing conventional detergent ingredients such as detersive surfactants (including anionics), detergency builders, optical brighteners, detersive enzymes, fabric bleaches, and the like, all at rather conventional levels, as well as clay fabric softeners (preferably, smectite clays), said compositions also containing at least 0.1% (preferably 1.0%. to 15%) of the aforesaid sub-stoichiometric, water-insoluble, water-dispersible amine-phosphate ester softeners. The most preferred compositions with clay are formulated to contain not more than 5% (preferably not more than l%-2%) of a nonionic detersive surfactant.

The invention also encompasses an article for use in a laundry bath or rinse bath, or in a laundry dryer, comprising the aforesaid sub-stoichiometric amine-phosphate ester softeners releasably affixed to a water-insoluble carrier, for example, a sheet of paper or fabric. Such compositions are optionally formulated to contain a bleach activator and such activator-containing compositions are especially useful in laundry baths.

The ingredients and means for preparing the compositions are disclosed more fully hereinafter^ All weights and proportions are by weight, unless otherwise specified.

As noted hereinafter, the compositions of this invention comprise, in major part, conventional ingredients that are quite familiar to formulators of laundry compositions. One of the major advantages of the amine-phosphate softeners used herein is that they are entirely compatible with such conventional laundry ingredients, used at conventional concentrations.

Amines - The amines employed herein are of the formula R1R2R3N where Rj^ is Cg to C2Qalkyl, R2 is to C2Q alkyl or hydrogen, and R^ is to C., θ alkyl or hydrogen.

Preferably, the amines have both R^ and R2 as C,-C__ alkyl, with Cn,-C1o being most preferred, o ZU xo lo and with R3 as C^-Cj alkyl. Mixed amines, such as dicoconutalkyl- and ditallowalkyl-methyl amines can be used. Such materials are commercially available under Trade Marks such as Armeen.

Phosphate Ester - The phosphate esters which are critical to the practice of this invention are commercially available materials of the general formulae: O II RO - P - OH and II HO - P - OH OR' OR' wherein R and R' are C1-C2Q alkyl or (preferably) ethoxylated alkyl groups of the general formulae: alkyl-(ΟΟΗ2<ΖΗ2)γ. wherein the alkyl substituent is C1-C2Q, preferably Cg-C16 and Y is an integer of 1 to 15, preferably 2-10, most preferably 2-5. Such compounds are prepared by known methods from phosphorus pentoxide, phosphoric acid or phosphorus oxy halide and alcohols or ethoxylated alcohols.

It will be appreciated that the formulae depicted represent mono- and di-esters, and commercial phosphate esters will generally comprise mixtures of the mono- and di-esters, together with some proportion of tri-ester. Typical commercial esters are available under the Trade Marks Phospholan PDB3 (Diamond Shamrock) and Servoxyl VPAZ (Servo).

Amine-Phosphate Ester Softeners - The prior art describes various phosphate ester-amine compounds - see U.S. Patent 3,364,192 - some of which have been disclosed for use as fiber-finishing agents - see U.S. Patents 3,434,874; 3,428,481; and 3,560,382. However, the prior art compositions generally involve 1:1 (mole basis) compounds or complexes, i.e., compounds or complexes from stoichiometric mixtures. Surprisingly, such stoichiometric complexes are of no use in the present invention, apparently because they form unstable dispersions prone to aggregation. In contrast, the sub-stoichiometric mixtures herein are extremely well dispersed in water, but are not water-soluble.

While not intending to be limited by theory, it is instructive to consider the physico-chemical behaviour of the amine-phosphate ester softeners herein, inasmuch as this can be of assistance to the formulator.

It will be appreciated that the amines used herein and in art-disclosed compositions exist in aqueous solutions as fairly coarse particles, or oily globules, having a spectrum of sizes. It appears that attachment of such particles to fabrics to provide the desired softening action can be considerably enhanced by reduction of their average size; coarser material being rinsed away by mechanical action. On the other hand, complete solubilization or micellization is to be avoided since this also leads to inadequate attachment of the amine to fabrics.

In addition to size of the dispersed amine particles, their phase structure is of importance since this will influence their effective spreading after attachment to fiber or fabric surfaces. Phase structure influences also the stability of amine dispersions.

Consideration of these factors apparently explains why, on one hand, amines untreated with phosphate ester and on the other hand, stoichiometric amine-ester complexes are of very low effectiveness relative to the sub-stoichiometric mixtures of amine-phosphate ester now disclosed.

It has now been discovered that sub-stoichiometric mixtures of amine-phosphate ester exist as aqueous dispersions whose particles readily deposit on, spread on, and soften, fibers and fabrics.

By "sub-stoichiometric herein is meant that there is an excess of amine relative to phosphate ester. In general, there are at least about two parts amine (on a weight basis) per one part (weight) of phosphate ester, but this will, of course, vary with the molecular weights of the amine and ester, respectively. The objective is to have a readily-dispersible (in water) mixture, but not one that is water-soluble.

Useful amine-phosphate esters can easily be observed by a simple test. The amines herein, suspended in water, form a generally greasy-appearing. non-homogeneous mixture. By contrast, the sub-stoichiometric amine-phosphate ester mixtures used in this invention form stable milky suspensions in water. Laboratory estimates of the particle sizes of these suspensions indicate that 60% to 80% of the particles fall within the size range of 0.1 to 8 micrometers; 20% to 40% within the range 8 to 20 micrometers; and essentially all the particles are below 40 micrometers in diameter.

For the preferred sub-stoichiometric amine-phosphate ester softeners herein, the weight ratio of amine:phosphate ester is above 5:1. generally 7:1 to 15:1, most preferably 10:1. Again, such softeners are selected to be water-dispersible, not water-soluble.

In general terms, the amine-phosphate ester softeners are prepared separately from the balance of the compositions, and are preferably then added to the other, conventional ingredients to provide the final formulations. This can most conveniently be done by preparing a melt of the phosphate ester and the amine and maintaining the melt stage for a few minutes. The melt can then be layered onto a sheet substrate to prepare, for example, a dryer-added fabric softener. To prepare a detergent, the melt can be solidified and comminuted to the desired particles size (e.g.. in an extruder), and dry-mixed with a granular detergent composition. The melt may also be sprayed onto detergent granules. The melt may also be dispersed into a stirred, aqueous crutcher mix comprising the balance of the detersive ingredients, and spray-dried in standard fashion. This crutcher-addition is less preferred, as it leads to some decomposition of the complex. Simply adding the amine and phospate ester, individually, to a detergent crutcher mix does not secure the intended benefits of this invention.

An especially preferred softener herein is prepared by melting together ten parts by weight of di-C^-Cj^ alkyl monomethyl amine and one part by weight of a mono (EO), ester of phosphoric acid, sold under the Trade Mark Servoxyl VPAZ.

The amine-phosphate ester softeners will generally be used at levels of at least 0.1%. preferably 1% to 15%. in detergent compositions; at levels of at least 1%, preferably 1% to 25% in rinse-added fabric softeners; and at levels of 2% to 60% in dryer- and wash machine- added sheets (where the balance of the composition mainly comprises the weight of the sheet substrate).

Softener Clay - The above-disclosed amine-phosphate ester softeners are preferably used in granular detergent compsitions. where they are most preferably used in combination with a detergent-compatible clay fabric 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 document 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 2-7%.

Detersive Surfactants - The detergent 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 surfactant useful herein include well-known synthetic anionic, amphoteric and zwitterionic surfactants. Typical of these are the alkyl benzene sulfonates, alkyl- and alkylether sulfates, paraffin sulfonates, olefin sulfonates, amine oxides, oi -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 C_-CL range; the anionic detersive surfactants can be 9 18 used in the form of their sodium, potassium or tr iethanolammonium salts. 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 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.

It is to be understood that the use of typical alkoxylated nonionic surfactants (e.g. the CQ-C,o alkyl) alcohols and alkyl phenols with 5 to 20 ethoxyl groups) are preferably limited in the practice of this invention to levels of not more than about 5%, preferably not more than 2%. most preferably 0-1%, of the compositions when clay is present as a co-softener, since alkoxylates can interfere with the softening properties of clay. In clay-free compositions, the alkoxylated nonionics can be used at any desired level.

The surfactant component can comprise as little as 1% of the laundry detergent compositions herein, but generally the compositions will contain 5% to 40%, preferably 6% to 30%, of surfactant. Mixtures of the 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 fabric.

Detersive Adjuncts - The compositions herein can contain other ingredients which aid in their cleaning performance. For example, it is highly preferred that 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. 1 citrates, water-soluble phosphates such as tri-polyphosphate and sodium ortho- and pyro-phosphates, silicates, and mixtures thereof. Metal ion seguestrants include all of the above, plus materials like ethylene diaminetetraacetate, 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 compositions which contain the softeners described herein.

The laundry compositions herein also preferably contain enzymes to enhance their through-the-wash cleaning performance on a variety of soils and stains. 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.

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, bleaches, optical brighteners, soil suspending agents, hydrotropes and gel-control agents, freeze-thaw stabilizers, bactericides, preservatives, suds control agents, bleach activators and the like.

*Trade Mark ί 2 The compositions can further contain a peroxygen bleach activator, particularly tetraacetyl ethylenediamine (TAED). typically from 0.1% to 5%. preferably from 0.5% to 2.5%. Other highly desirable detergent ingredients for use in the detergent compositions of the present invention are quaternary ammonium compounds of the form R^R^RgR^N+X-, wherein R^ is alkyl having from 10 to 20. preferably from 12-18 carbon atoms, and R^.Rg and R? are each to alkyl preferably methyl; X- is an anion, e.g. chloride. Examples of such quaternary ammonium compounds include monotallowalkyl trimethyl ammonium chloride and mono(cocoalkyl) trimethyl ammonium roethosulfate. The quaternary ammonium compounds can be used at levels from 0.5% to 5%, preferably from 1% to 3%. Detergent compositions containing both TAED and the mono(long chain alkyl) tri(short chain alkyl) ammonium compound are highly preferred.

In a through-the-wash laundry mode, the compositions are typically used at a concentration of at least 500 ppm, preferably 0.10% to 2.5%, 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 .

In an alternate mode, the amine-phosphate ester softeners herein may be releasably adsorbed or releasably coated onto a non-particulate substrate such as a non-woven or paper sheet or flexible sponge mat, or the like. Such sheet-form objects may be added to the laundry or rinse bath, or to the laundry dryer, where the softener is released to provide fabric softening. In an alternate, and highly preferred, mode the amine-phosphate ester softener is used in sheet form in combination with a bleach activator (such as tetraacetyl ethylene diamine or 3 a straight- or branched-chain Cc-C,Λ oxybenzene b lu sulfonate) as a combined perborate-activator and softener in a laundry liquor. See, for example U.S. Patent 4, 220, 562 .

Such sheet-form products will generally employ 1-20 grams of the amine-phosphate ester softener and 1-20 grams of the bleach activator.

In still another mode, the amine-phosphate ester can be formulated as a liquid fabric softener and used in a post-laundry rinse bath. Such liquid softeners can comprise, for example, a simple dispersion of the amine-phosphate ester softener in water or water-alcohol.

It is to be understood that the compositions and processes of this invention are carried out in a manner that will, typically, deposit at least a few milligrams (generally, at least 1-1000 mg) of the sub-stoichiometric amine-phosphate ester softener per square meter on the fabric being treated, as will be seen in the following examples .

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

EXAMPLE I A mix of ditallow methyl amine (total 3.8% of complete formulation after spray-drying) and monococonutalkyl(ethoxy)1-5 phosphoric acid ester (0.38% of complete formulation) are admixed, melted in a jacketed bath, and maintained as a melt for about ten minutes. Stirring assures homogeneity. 4 A standard aqueous crutcher mix comprising the following ingredients is prepared (percentages listed relate to percent ingredients in the complete formulation after spray-drying).

Inqredients Percent C-^-^2 alKyi benzene sulfonate 6.2 Tallow alcohol ethoxylate (EO11) 1.0 Sodium perborate 20.0 Sodium tripolyphosphate 24.0 Sodium sulfate 22.0 Sodium silicate 8.0 Smectite Clay * 2.4 Carboxymethyl cellulose 0.4 Polyacrylate (soil suspender) 1.7 Enzymes 0.5 Optical brightener 0.23 Sulphonated zinc phthalocyanine ** 25 ppm EDTA 0.2 Perfume/copper salts/minors 0.5 Moisture to 100 * Natural smectite; ion exchange capacity above 50 meq/lOOg clay; ** U.S. Patent 3 927 967 The crutcher mix is handled in entirely standard fashion, and spray-dried to form a granular composition.

The amine-phosphate ester softener is added to the spray-dried granules as particles or prills.

The composition of Example I is free-flowing and provides excellent cleaning and through-the-wash fabric softening when used at laundry concentration of 0.1% and above.

In an alternate mode, the amine-phosphate ester softener can be sprayed onto the spray-dried granules.

The composition of Example I may be modified by adding 1.0% tetraacetyl ethylenediamine (TAED) as a perborate bleach activator. It is preferred that materials such as bleach activators and enzymes be dry-mixed with the balance of the composition, after spray-drying.

The composition may be modified further by adding, in addition to TAED, 2.4% monotalIowaIky1 trimethyl ammonium chloride.

EXAMPLE II A low-P spray-dried detergent formulation is as follows : Ingredient Percent Zeolite A (1-10 micron) 26.0 Sodium nitrilotriacetate 5.0 Smectite clay * 3.0 Amine-phosphate Ester ** 4.1 alkyl benzene sulfonate (Na) 6.5 Tallow ethoxylate (EO 9-11) 0.5 Sodium Perborate .4H20 20.0 Sodium silicate 8.0 CMC 1.0 Sodium sulfate 20.0 Enzymes (1:1 amylase/protease) *** 1.5 Optical brightener 0.5 TAED 1.2 Water, minors to 100 As Gelwhite GP (TM);CaCO3 ion exchange capacity 70 Meq/lOOg.

As in Example I.

Dry-mixed with composition. 6 The composition of Example II is prepared by spray-drying an aqueous crutcher mix, in the manner described for Example I. In use, the composition gives excellent cleaning and through-the-wash fabric softening performance.

EXAMPLE III A clay-free composition is prepared by removing the clay from Example I and substituting therefor an additional softener comprising monotallowalkyl trimethyl ammonium chloride as 2.4% of the total composition.

EXAMPLE IV A laundry additive product is prepared by warming 6.5g of bis(tetradecyl)methyl amine and O.8g of tetradecylphosphate to form a melt, and spreading the melt onto an ordinary disposable paper hand-towel (20x20 cm). grams of TAED powder (1-10 microns) are sprinkled onto, and pressed into, the melt before it has the chance to solidify.

The article of Example IV is added to a laundry liquor containing a commercial perborate/clay detergent composition (DASH-3; Trade Mark) to enhance through-the-wash softening and bleaching performance.

EXAMPLE V The article of Example IV is modified by deleting the TAED and replacing the Example IV softener with 3.5g. of the amine-phosphate ester softener of Examples I and II. The resulting article is tumbled with damp fabrics in a standard hot air clothes dryer, whereby the softener is transferred to the fabrics to impart softness. 7 EXAMPLE VI A fine-fabric laundering composition with fabric softening properties is as follows : Ingredient 5 C10-14 A1Xyl Sulfate Tallow alkyl benzene sulfonate Coconut Soap Glycerine Amine-Phosphate ester complex * 10 Triethanolamine Perfume Water Percent 9.0 2.0 4.0 3.0 6.0 to pH 7.0 0.25 to 100 * Octadecyl amine (15 parts)/bis-decylphosphate (1 part) as melt.

The composition of Example VI is in the form of a milky liquid.

Claims (5)

CLAIMS: 1. Ί) A composition according to Claim 3 or 4, which also contains at least 1% by weight of a clay fabric softener. 6. A composition according to Claim 5, which contains 5 not more than 5% by weight of an alkoxylated nonionic detersive surfactant. 7. A composition according to any one of Claims 3 to 6, which contains a detergency builder selected from phosphate, nitrilotriacetate, polycarboxylate, citrate 10 and zeolite builders, or a mixture thereof. 8. A composition according to any one of the Claims 3 to 7, which contains from 0.1% to 5% by weight of tetraacetyl ethylenediamine and from 0.5% to 5% by weight of a quaternary ammonium compound of the formula 15 R 4 R 5 R 6 R 7 N + X - , wherein R 4 is alkyl having from 10 to 20 carbon atoms, R^, R g and R? are each alkyl having from 1 to 4 carbon atoms, and X - is an anion. 9. An article for use in a laundry or rinse bath, or in a laundry dryer, comprising a non-particulate 20 water-insoluble substrate, preferably a flexible sheet, having releasably affixed thereto a fabric softener which comprises the complex of Claim 1. 10. An article according to Claim 9, which additionally has affixed thereto a bleach activator. 25 11. A method according to Claim 1 of softening fibers or fabrics, substantially as hereinbefore described. 12. A laundry detergent composition according to Claim 3, substantially as hereinbefore described and exemplified. 13. An article according to Claim 9, substantially as 1.

1. A method of softening fibers or fabrics which comprises contacting said fibers or fabrics with an aqueous laundry liquor comprising a water-dispersible complex of an amine of the formula RjR 2 R 3 N where is Cg to C^q alkyl, R^ is to C 2Q alkyl or hydrogen, and R 3 is to C 1Q alkyl or hydrogen, and a phosphate ester of the formula O 0 RO P—OH or HO P OH OR' OR' wherein R and R* are each C^-C 2Q alkyl or (preferably) an ethoxylated alkyl group of the general formula: alkyl (OCH 2 CH 2 )y, wherein the alkyl substituent is C-^-C^, preferably C g -C 16 and Y is an integer of 1 to 15, preferably 2-10, most preferably 2-5, said complex containing a stoichiometric excess of amine relative to phosphate ester.

2. A method of softening fabrics which is carried out by tumbling damp fabrics in a hot air clothes dryer while contacting said fabrics with the complex of Claim

3. A laundry detergent composition comprising conventional detersive ingredients, which contains at least 0.1% by weight of the complex of Claim 1.

4. A composition according to Claim 3, which contains from 1% to 15% by weight of said complex.

5. Hereinbefore described.