WO2000040687A1 - Fabric care composition containing a protein - Google Patents

Abstract

The present invention relates to a farbic care composition containing a fabric softening active and a protein, wherein from about 20 % to about 40 % of the amino acid in the primary structure of the protein is serine, and wherein the pH of the fabric care composition is less than 7 at 25 °C. The protein is preferably sericin.

Description

FABRIC CARE COMPOSITION CONTAINING A PROTEIN

FIELD The present invention relates to fabric care compositions. More particularly, the present invention relates to a fabric care composition containing a protein.

BACKGROUND Fabric softening actives are known to be added to laundry applications, for example, in order to provide softer fabrics, to reduce or eliminate static, to reduce or eliminate wrinkles and to enhance in-wear comfort. Traditionally, such fabric softening actives have been used to provide benefits on fabrics such as clothes. These fabric softening actives are typically added in the rinse cycle of a laundering operation or applied on a sheeted substrate and used in a cloth dryer.

Due to the limitation in detergency, laundered fabrics may not be completely cleaned after the wash. For example, especially on cotton fabric, the fabric may develop a yellow hue or color with repeated laundering, which is highly undesirable to consumers. Consumers sometimes associate this fabric having a yellow color with the term "dingy" fabrics. While not intended to be limited by theory, it is believed that such yellow "dinginess" hue comes from unsaturated lipid residue left on the fabric surface. After the unsaturated lipid residue is oxidized by air, it turns into a yellow color and the fabric becomes "dingy" in appearance. Furthermore, consumers expect that laundered fabrics have certain physical properties after being washed in detergent compositions, such as feeling soft to the touch, reduced wrinkling, and have little electrostatic charge (e.g. static cling).

Silk protein derivatives, such as sericin protein, have been used in liquid hard surface cleaners, including light duty liquid detergent compositions such as for washing dishes and tables. Liquid hard surface cleaners containing silk protein derivatives are known to be mild to human skin.

It has now been found that a fabric care composition containing a protein is especially beneficial for cleaning fabrics, such as reducing fabric "dinginess", as well as unexpectedly providing consumer desirable benefits to the washed fabric, such as softness, reduced wrinkling, enhanced moisture retention, and a reduced electrostatic charge. The fabric softener product form has also been surprisingly found to be an effective way of delivering protein, such as sericin, onto fabrics for potential skin protection benefits upon wearing. None of the existing art provides all of the advantages and benefits of the present invention.

SUMMARY

The present invention relates to a fabric care composition containing a fabric softening active and a protein, wherein from about 20% to about 40% of the amino acid in the primary structure of the protein is serine, and wherein the pH of the fabric care composition is less than 7 at 25°C. The protein is preferably sericin.

These and other features, aspects, and advantages of the present invention will become evident to those skilled in the art from a reading of the present disclosure with the appended claims.

DETAILED DESCRIPTION It has now been found that a fabric care composition containing a protein is especially beneficial for treating fabrics, such as providing consumer desirable benefits to the washed fabric, such as softness, reduced wrinkling, enhanced moisture retention, reduced electrostatic charge, and enhanced in-wear comfort. The fabric softener product form has also been surprisingly found to be an effective way of delivering protein, such as sericin, onto fabrics for potential skin protection benefits upon wearing. It has now been found that such fabric care compositions help the deposition of protein, such as sericin, onto the fabric to deliver the desired benefits. All percentages, ratios and proportions herein are by weight of the fabric care composition, unless otherwise specified. All temperatures are in degrees Celsius (°C) unless otherwise specified. All documents cited are incorporated herein by reference. As used herein, the term "alkyl" means a hydrocarbyl moiety which is straight or branched, saturated or unsaturated. Unless otherwise specified, alkyl moieties are preferably saturated or unsaturated with double bonds, preferably with one or two double bonds. Included in the term "alkyl" is the alkyl portion of acyl groups. The fabric care composition in the present invention may add softening effects to fabrics, reduce wrinkle formation on fabric, reduce electrostatic on the fabric surface, enhance moisture retention, and increase in-wear comfort. While not intended to be limited by theory, it is believed that the fabric care composition of the present invention helps deposit protein actives onto fabrics due to the anionic nature of the softener composition. Once deposited, a protein such as sericin is an effective moisture retention agent to negate the effect of the softener effect which is known to reduce the water absorption ability of fabrics. Moisture retention is important in reducing wrinkles, and preventing electrostatic charge build-up, while keeping the softening effect of the softener. While not intended to be limited by theory, it is also believed that the protein protects the human skin through skin or surface deposition, and as a result there are skin care and skin mildness benefits.

In addition, the protein has a hydroxyl group in the molecule (-OH). Although not wanting to be limited by theory, since the hydroxyl group traps water, the protein has a high water absorption in the molecule. When such protein is attached to the fabric, the fabric feels soft to the skin. In addition, the wrinkles on the fabric surface is reduced and the formation of electrostatic charge on the fabric is reduced. If the percentage of the serine in the primary structure of the protein is lower than 20%, the protein does not have a high water absorption. If the amount is above 40%, when synthesized by the recombinant method, the rate of the synthesis reaction becomes slow, and a sufficient amount of the recombinant protein may not be produced. Therefore, the percentage of the serine in the primary structure of the protein should be from about 20% to about 40%.

The fabric care composition of the present invention also reduces the yellow "dingy" hue left on fabrics. Although not wanting to be limited by theory, it is believed that the oxidation of residual unsaturated lipid residues on fabric cause yellow color dinginess. Yellow dinginess is a yellow hue left on the fabric surface even after cleaning, and is especially common with cotton fabrics. If the lipid residue left on the fabric surface becomes oxidized upon contact with air, the lipid residue color turns yellow via polymerization and decomposition. As the protein prevents the lipid residue from becoming oxidized on the fabric surface, yellow dinginess on the fabric is substantially reduced.

The protein used in the present invention is unique in that it has a high content of serine amino acid, is chemically stable under laundering conditions, and is effective in preventing oxidation. Furthermore, the fabric care composition containing the protein may reduce allergic reactions for skin-sensitive individuals who comes into contact with fabric treated with the fabric care composition of the present invention since the protein is uniquely known to be compatible with human skin. Also, if skin- sensitive individuals come into direct contact with the fabric care composition of the present invention, such as when manually handling the fabric treated with the composition or handling the composition directly, the fabric care composition is mild to the hands. Protein

The percentage of serine in the primary structure of the protein of the present invention is from about 20% to about 40%. A preferred molecular weight of the protein of the present invention if from about 1 kDa to about 400 kDa, preferably from about 65 kDa to about 400 kDa, even more preferably from about 100 kDa to about 400 kDa. The protein may be obtained from a silk material. Silk material includes cocoons, raw silk, waste cocoons, raw silk waste, silk fabric waste and the like. A silk material mainly contains two major types of proteins. One type is fibroin (about 70% by weight of a typical silk protein); another type is sericin (from about 20% to about 30% by weight of a typical silk protein). Sericin is a preferred protein. Any type of protein which contains from about 20% to about 40% of serine as the amino acid in the primary structure, can be used for the present invention.

When deriving sericin from a cocoon, one can preferably either treat the cocoon in boiling water or treat the cocoon in an alkaline solution, such as one containing sodium hydroxide (NaOH). If boiling water is used, the molecular weight of the derived sericin is from about 65 Kilo Dalton (kDa) to about 400 kDa.

If an alkaline solution is used, the molecular weight of the derived sericin is from about 1 kDa to about 30 kDa. Although not wanting to be limited by theory, it is believed that since the alkaline treatment is a harder condition for the sericin than boiling water, the sericin may become partially decomposed and thus, the molecular weight of the sericin is less. Any molecule of sericin can be used for the present invention. The larger molecule of sericin is preferable since the larger molecules of sericin retain their function better. Sericin may be obtained from silk fabrics directly using a chemical purification method. As explained above, the molecular weight of natural sericin is usually lower than about 400 kDa.

Sericin is derived from silk materials or synthesized using conventionally known biological methods, for example, by inserting the sericin gene sequence into E. coli, in which the E. coli produces recombinant sericin. Either natural or recombinant sericin can be used for the present invention. Sericin in the present invention includes any sericin derivative amino acid sequences which lack, add or replace one or more amino acid.

The fabric care composition of the present invention preferably contains from about 0.05% to about 50% by weight of the composition, more preferably, from about 0.5% to about 30%, and even more preferably from about 1% to about 20% of sericin.

Fabric Softening Active

A fabric care composition herein preferably comprises from about 1% to about 70%, preferably from about 3% to about 50%, and more preferably from about 5% to about 40% of a fabric softening active by weight of the fabric care composition. Without intending to be limited by theory, it is believed that the fabric softening actives provide fabric that is softer and has reduced static, easy to iron, and has improved shape retention, wrinkle reduction, enhanced moisture retention, and a reduced likelihood of leaving darkened marks.

The fabric softening actives useful herein may be any of those known for use in a laundry process. Preferred fabric softening actives include quaternary ammonium compounds or amine precursors thereof, cationic ammonium softening compounds, nonionic softening compounds, and mixtures thereof.

The preferred quaternary ammonium compounds or amine precursors of the present invention are cationic biodegradable quaternary ammonium compounds having the formula (II) , (III), (IV, or (V), (VI) below :

(II) or

(III)

or

(IV)

(V)

or

(CH2)n-Q-Rl

Rl - N +- (CH2)n-Q-Tl

I

(CH2)n-Q-T2 (VI)

wherein Q, n, R and T are selected independently and

Q is -O-C(O)- or -C(O)-O- or -O-C(O)-O- or -NR4-C(O)- or -C(O)-NR4- or

(OCCCH2CH2)m-OCH2COO- m = 0 - 10;

R1 is (CH₂)n-Q-T² or T^ or R3 ;

R2 is (CH₂)_m-Q-T4 or T$ or R3;

R3 is C1-C4 alkyl or C1-C4 hydroxyalkyl or H;

R4 is H or C1-C4 alkyl or C-1-C4 hydroxyalkyl;

R5 is C1-C4 alkylene groups;

T¹ , T², T³, T⁴, T⁵ are (the same or different) C-| 1-C22 alkyl or alkenyl; n and m are integers from 1 to 4; and

X" is a softener-compatible anion, such as chloride, methyl sulfate, etc. The alkyl, or alkenyl, chain T¹ , T², T³, T⁴, T⁵ must contain at least 11 carbon atoms, preferably at least 16 carbon atoms. The chain may be straight or branched.

Q, n, T¹ , and T^{2 ma}y be the same or different when more than one is present in the molecule.

Tallow is a convenient and inexpensive source of long chain alkyl and alkenyl material. Another convenient source would be palm olein oil. The compounds wherein T¹ , T², T³, T⁴, T^ represents the mixture of long chain materials typical for tallow or palm olein are particularly preferred. Preferred quaternary ammonium compounds or amine precursors thereof include those of formula (II) or (III) or (VI) wherein Q is -O-C(O)-, R¹ is (CH2)_n-Q- T², R² and R³ are the same or different and are C1-C4 alkyl or C1-C4 hydroxyalkyl or H; T¹ and T² are (the same or different) C-| 1-C22 alkyl or alkenyl; n and m are integers from 1 to 4; and X^" is a softener-compatible anion, such as chloride, methyl sulfate, etc.

Specific examples of quaternary ammonium compounds of formula (II) or (III) suitable for use in the aqueous fabric softening compositions herein include :

1) N,N-di(tallowyl-oxy-ethyl)-N,N-dimethyl ammonium chloride;

2) N,N-di(tallowyl-oxy-ethyl)-N-methyl, N-(2-hydroxyethyl) ammonium chloride;

3) 1 ,2-ditallowyloxy-3-N,N,N-trimethylammoniopropane chloride.;

4) N,N-di(palmityI-oxy-ethyl)-N-hydroxyethyI, N-methyl ammonium methyl sulfate.

5) N,N-ditallow-oxy-ethyl-N,-hydroxyethyl, N-methyl ammonium chloride. and mixtures of any of the above materials.

Of these, compounds 1-2 are examples of compounds of Formula (II); compound 3 is a compound of Formula (III); compounds 4-5 are examples of compound (VI).

Particularly preferred is N,N-di(tallowoyl-oxy-ethyl)-N,N-dimethyl ammonium chloride, where the tallow chains are at least partially unsaturated, and N,N-ditallow-oxy-ethyl-N-hydroxyethyl, N-methyl ammonium chloride and its ethoxylated equivalents The level of unsaturation of the tallow chain can be measured by the Iodine Value (IV) of the corresponding fatty acid, which in the present case should preferably be in the range of from 5 to 100 with two categories of compounds being distinguished, having a IV below or above 25, and a variable IV value for VI depending on the degree of ethxoylation, in which the more ethoxylation, the less IV.

Indeed, for compounds of Formula (II) made from tallow fatty acids having a IV of from 5 to 25, preferably 15 to 20, it has been found that a cis/trans isomer weight ratio greater than about 30/70, preferably greater than about 50/50 and more preferably greater than about 70/30 provides optimal concentrability.

For compounds of Formula (II) made from tallow fatty acids having a IV of above 25, the ratio of cis to trans isomers has been found to be less critical unless very high concentrations are needed.

At least 80% of the preferred diester quaternary ammonium compounds, i.e., DEQA of formula (II), (III), and (VI) is preferably in the diester form, and from 0% to about 30%, preferably less than about 25%, more preferably less than about 20%, can be monoester, i.e., DEQA monoester (e.g., containing only one -Q-T¹ group). As used herein, when the diester is specified, it will include the monoester that is normally present in manufacture. For softening, under no/low detergent carry-over laundry conditions the percentage of monoester should be as low as possible, preferably no more than about 2.5%. However, under high detergent carry-over conditions, some monoester is preferred. The overall ratios of diester to monoester are from about 100:1 to about 2:1 , preferably from about 50:1 to about 5:1 , more preferably from about 13:1 to about 8:1. Under high detergent carry-over conditions, the di/monoester ratio is preferably about 11 :1. The level of monoester present can be controlled in the manufacturing of the softener compound.

Other examples of suitable quaternary ammonium compounds of Formula (II), (III) and (VI) are obtained by, e.g., - replacing "tallow" in the above compounds with, for example, coco, palm, lauryl, oleyl, ricinoleyl, stearyl, palmityl, or the like, said fatty acyl chains being either fully saturated, or preferably at least partly unsaturated; - replacing "methyl" in the above compounds with ethyl, ethoxy, propyl, propoxy, isopropyl, butyl, isobutyl or t-butyl;

- replacing "chloride" in the above compounds with bromide, methylsulfate, formate, sulfate, nitrate, and the like.

In fact, the anion is merely present as a counterion of the positively charged quaternary ammonium compounds. The nature of the counterion is not critical at all to the practice of the present invention. The scope of this invention is not considered limited to any particular anion. By "amine precursors thereof is meant the secondary or tertiary amines corresponding to the above quaternary ammonium compounds.

Other formula (II) quaternary ammonium compounds useful as fabric softeners in the present invention include:

(i) diamido quaternary ammonium salts having the formula:

O R5 O

II

Rl- -C-NH- -R2-N-R2-NH— C— Ri A^' I R9

wherein R^ is an acyclic aliphatic C-15-C21 hydrocarbon group, each R² is the same or different divalent alkylene group having 1 to 3 carbon atoms, R⁵ and R9 are C1-C4 saturated alkyl or hydroxyalkyl groups, or (CH2CH2θ)_nH wherein n is equal to 1 to about 5 and A- is an anion; (ϋ)

O R O

II A-

R'-C-NH-R²-N-Rⁱ-O-C-R' wherein R^ is an acyclic aliphatic C-15-C21 hydrocarbon group, R² is the same or different divalent alkylene group having 1 to 3 carbon atoms, R^ are C1-C4 saturated alkyl or hydroxyalkyl groups, A- is an anion and R² is the same or different from the other R², and (iii) mixtures thereof. Examples of compounds of (i) or (ii) as described above are the well- known and include methyl bis(tallowamidoethyl)(2-hydroxyethyl)ammonium methylsulfate and methyl bis(hydrogenated tallowamidoethyl)(2- hydroxyethyl)ammonium methylsulfate; these materials are available from Witco Chemical Company under the trade names Varisoft® 222 and Varisoft® 110, respectively: The quaternary ammonium or amine precursors compounds herein are present at levels of from about 0.05% to about 50% by weight of compositions herein, depending on the composition execution which can be diluted with a preferred level of active from about 5% to about 15% by weight, or concentrated, with a preferred level of active from about 15% to about 50%, most preferably about 15% to about 35% by weight.

The pH of these compositions herein can be regulated by the addition of a

Brønsted acid.

Examples of suitable Brønsted acids include the inorganic mineral acids, carboxylic acids, in particular the low molecular weight (C1-C5) carboxylic acids, and alkylsulfonic acids. Suitable inorganic acids include HCI, H2SO4, HNO3 and

H3PO4. Suitable organic acids include formic, acetic, citric, lactic, benzoic, methylsulfonic and ethylsulfonic acid. Preferred acids are citric, hydrochloric, phosphoric, formic, methylsulfonic acid, lactic acid and benzoic acids. Cationic fabric softening compounds useful herein are described in U.S.

Pat. No. 4,661 ,269, issued April 28, 1987, in the names of Toan Trinh, Errol H. Wahl, Donald M. Swartley, and Ronald L. Hemingway; U.S. Pat. No. 4,439,335, Burns, issued March 27, 1984; and in U.S. Pat. Nos.: 3,861 ,870, Edwards and Diehl; 4,308,151 , Cambre; 3,886,075, Bernardino; 4,233,164, Davis; 4,401 ,578, Verbruggen; 3,974,076, Wiersema and Rieke; 4,237,016, Rudkin, Clint, and Young; and European Patent Application publication No. 472,178, by Yamamura et al., the disclosures of which are all herein incorporated by reference.

For example, additional cationic fabric softener agents useful herein may comprise one or two of the following fabric softening agents: (a) the reaction product of higher fatty acids with a polyamine selected from the group consisting of hydroxyalkylalkylenediamines and dialkylenetriamines and mixtures thereof (preferably from about 10% to about 80%); and/or

(b) cationic nitrogenous salts containing long chain acyclic aliphatic C15-

C22 hydrocarbon groups (preferably from about 3% to about 40%); with said (a) and (b) preferred percentages being by weight of the fabric softening agent component of the present invention compositions.

Following are the general descriptions of the preceding (a) and (b) softener ingredients (including certain specific examples which illustrate, but do not limit the present invention). Component (a): Softening agents (actives) of the present invention may be the reaction products of higher fatty acids with a polyamine selected from the group consisting of hydroxyalkylalkylenediamines and dialkylenetriamines and mixtures thereof. These reaction products are mixtures of several compounds in view of the multi-functional structure of the polyamines. The preferred Component (a) is a nitrogenous compound selected from the group consisting of the reaction product mixtures or some selected components of the mixtures. More specifically, the preferred Component (a) is compounds selected from the group consisting of substituted imidazoline compounds having the formula:

wherein Ri is an acyclic aliphatic C15-C21 hydrocarbon group and R² is a divalent C1-C3 alkylene group, and Y is NH or O.

Component (a) materials are commercially available as: Mazamide® 6, sold by Mazer Chemicals, or Ceranine® HC, sold by Sandoz Colors &

Chemicals; stearic hydroxyethyl imidazoline sold under the trade names of

Alkazine® ST by Alkaril Chemicals, Inc., or Schercozoline® S by Scher

Chemicals, Inc.; N,N"-ditallowalkoyldiethylenetriamine; 1-tallowamidoethyl-2- tallowimidazoline (wherein in the preceding structure R1 is an aliphatic C15-C-17 hydrocarbon group and R² is a divalent ethylene group).

Certain of the Components (a) can also be first dispersed in a Brønsted acid dispersing aid having a pKa value of not greater than about 4; provided that the pH of the final composition is not greater than about 5. Some preferred dispersing aids are hydrochloric acid, phosphoric acid, or methylsulfonic acid.

Both N,N"-ditallowalkoyldiethylenetriamine and 1-tallow(amidoethyl)-2- tallowimidazoline are reaction products of tallow fatty acids and diethylenetriamine, and are precursors of the cationic fabric softening compound methyl-1-tallowamidoethyl-2-tallowimidazolinium methylsulfate (see "Cationic Surface Active Agents as Fabric Softeners," R. R. Egan, Journal of the American Oil Chemicals' Society, January 1978, pages 118-121). N,N"-ditallow alkoyldiethylenetriamine and 1-tallowamidoethyl-2-tallowimidazoline can be obtained from Witco Chemical Company as experimental chemicals. Methyl-1- tallowamidoethyl-2-tallowimidazolinium methylsulfate is sold by Witco Chemical Company under the tradename Varisoft® 475.

Component (b): The preferred Component (b) is a cationic nitrogenous salt, preferably selected from acyclic quaternary ammonium salts having the formula:

wherein R4 is an acyclic aliphatic C15-C22 hydrocarbon group, R^ is R⁴ or C1-C4 saturated alkyl or hydroxy alkyl groups, and R^ is R or R^ and A- is an anion.

Examples of Component (b) are the monoalkyltrimethylammonium salts such as monotallowtrimethylammonium chloride, mono(hydrogenatedtallow)trimethylammonium chloride, palmityltrimethyl ammonium chloride and soyatrimethylammonium chloride, sold by Witco Chemical Company under the trade name Adogen® 47I, Adogen® 441 , Adogen ® 444, and Adogen® 415, respectively. In these salts, R⁴ is an acyclic aliphatic C-iø-C-iδ hydrocarbon group, and R5 and R are methyl groups.

Mono(hydrogenated tallow)trimethylammonium chloride and monotallowtrimethylammonium chloride are preferred. Further examples include dialkyldi methylammonium salts such as ditallowdimethylammonium chloride. Examples of commercially available dialkyldimethyl ammonium salts usable in the present invention are di(hydrogenated tallow)dimethylammonium chloride (tradename Adogen® 442), ditallowdimethyl ammonium chloride (trade name Adogen® 470), distearyl dimethylammonium chloride (trade name Arosurf® TA- 100), all available from Witco Chemical Company, dimethylstearylbenzyl ammonium chloride sold under the trade names Varisoft® SDC by Witco Chemical Company and Ammonyx® 490 by Onyx Chemical Company. Also preferred are those selected from the group consisting of di(hydrogenated tallow)dimethylammonium chloride, ditallowdimethylammonium chloride. Mixtures of the above examples are also included within the scope of the present invention.

A preferred compound of Component (a) includes the reaction product of about 2 moles of hydrogenated tallow or palm fatty acids with about 1 mole of N- 2-hydroxyethylethylenediamine or diethylene triamine or 1-amino-2,3, propane diol, or ethylene diamine, N-hydroxyethyl, or trihydroxyethyl amine, or monohydroxydimethyl amine, or ethoxylated dihydroxyethyl methyl amine or ethoxylated trihydroxyethyl amine where the ethoxylation may contain 0 to 10 moles of ethylene oxide and is present at a level of from about 20% to about 70% by weight of the fabric softening component of the present invention compositions while preferred compounds of component (b) include mono(hydrogenated tallow)trimethyl ammonium chloride and di(hydrogenated tallow)dimethyl ammonium chloride present at a level of from about 3% to about 30% by weight of the fabric softening component of the present invention compositions; 1-tallowamidoethyl-2-tallowimidazoline, and mixtures thereof; wherein mixtures of compounds of (a) and (b) are present at a level of from about 20% to about 60% by weight of the fabric softening component of the present invention compositions; and wherein the weight ratio of said di(hydrogenated tallow)dimethylammonium chloride to said 1-tallowamidoethyl-2-tallowimidazoline is from about 1 :2 to about 6:1.

In the cationic nitrogenous salts described herein before, the anion A- provides charge neutrality. Most often, the anion used to provide charge neutrality in these salts is a halide, such as chloride or bromide. However, other anions can be used, such as methylsulfate, ethylsulfate, hydroxide, acetate, formate, citrate, sulfate, carbonate, and the like. Chloride and methylsulfate are preferred herein as anion A-. Nonionic softening compounds, preferably in combination with cationic softening compounds are also useful herein. Typically, such nonionic softener compounds have a HLB of from about 2 to about 9, more typically from about 3 to about 7. Such nonionic softener compounds tend to be readily dispersed either by themselves, or when combined with other materials such as single- long-chain alkyl cationic surfactant described in detail hereinafter. Dispersibility can be improved by using more single-long-chain alkyl cationic surfactant, mixture with other materials as set forth hereinafter, use of hotter water, and/or more agitation. In general, the materials selected should be relatively crystalline, higher melting, (e.g. >40 °C) and relatively water-insoluble. The level of optional nonionic softener compound in the compositions herein is typically from about 0% to about 10%, preferably from about 1% to about 5% by weight of the composition.

Preferred nonionic softener compounds are fatty acid partial esters of polyhydric alcohols, or anhydrides thereof, wherein the alcohol, or anhydride, contains from 2 to 18, preferably from 2 to 8, carbon atoms, and each fatty acid moiety contains from 12 to 30, preferably from 16 to 20, carbon atoms. Typically, such softeners contain from one to 3, preferably 2 fatty acid groups per molecule.

The polyhydric alcohol portion of the ester can be ethylene glycol, glycerol, poly (e.g., di-, tri-, tetra, penta-, and/or hexa-) glycerol, xylitol, sucrose, erythritol, pentaerythritol, sorbitol or sorbitan. Sorbitan esters and polyglycerol monostearate are particularly preferred. The fatty acid portion of the ester is normally derived from fatty acids having from 12 to 30, preferably from 16 to 20, carbon atoms, typical examples of said fatty acids being lauric acid, myristic acid, palmitic acid, stearic acid, oleic and behenic acid. Highly preferred optional nonionic softening agents for use in the present invention are the sorbitan esters, which are esterified dehydration products of sorbitol, and the glycerol esters.

Commercial sorbitan monostearate is a suitable material. Mixtures of sorbitan stearate and sorbitan palmitate having stearate/palmitate weight ratios varying between about 10:1 and about 1 :10, and 1 ,5-sorbitan esters are also useful.

Glycerol and polyglycerol esters, especially glycerol, diglycerol, triglycerol, and polyglycerol mono- and/or di-esters, preferably mono-, are preferred herein (e.g. polyglycerol monostearate with a trade name of Radiasurf 7248). Useful glycerol and polyglycerol esters include mono-esters with stearic, oleic, palmitic, lauric, isostearic, myristic, and/or behenic acids and the diesters of stearic, oleic, palmitic, lauric, isostearic, behenic, and/or myristic acids. It is understood that the typical mono-ester contains some di- and tri-ester, etc.

The "glycerol esters" also include the polyglycerol, e.g., diglycerol through octaglycerol esters. The polyglycerol polyols are formed by condensing glycerin or epichlorohydrin together to link the glycerol moieties via ether linkages. The mono- and/or diesters of the polyglycerol polyols are preferred, the fatty acyl groups typically being those described herein before for the sorbitan and glycerol esters. In addition, since the foregoing compounds (diesters) are somewhat labile to hydrolysis, they should be handled rather carefully when used to formulate the compositions herein. For example, stable liquid compositions herein are formulated at a pH (neat) in the range of from about 2 to about 7, preferably from about 2 to about 5, more preferably from about 2 to about 4.5. For best product odor stability, when the IV is greater that about 25, the neat pH is from about 2.8 to about 3.5, especially for lightly scented products. This appears to be true for all of the above softener compounds and is especially true for the preferred DEQA specified herein, i.e., having an IV of greater than about 20, preferably greater than about 40. The limitation is more important as IV increases. The pH can be adjusted by the addition of a Brønsted acid as described above. pH ranges for making chemically stable softener compositions containing diester quaternary ammonium fabric softening compounds are disclosed in U.S. Pat. No. 4,767,547, Straathof et al., issued on Aug. 30, 1988, which is incorporated herein by reference.

A preferred fabric softening active is selected from the group consisting of ditallow or dipalmityl dimethylammonium chloride or methyl sulfate (DTDMAC); dihydrogenated tallow (palm) dimethylammonium chloride; dihydrogenated tallow (palm) dimethylammonium methylsulfate; distearyl dimethylammonium chloride; dioleyl dimethylammonium chloride or methyl sulfate; dipalmityl hydroxyethyl methylammonium chloride or methyl sulfate; stearyl benzyl dimethylammonium chloride or methyl sulfate; tallow (palm) trimethylammonium chloride or methyl sulfate; hydrogenated tallow (palm) trimethylammonium chloride or methyl sulfate; C-i2"20 alkyl ethoxyhydroxyethyl or hydroxyethyl dimethylammonium chloride or methyl sulfate; di-C-|2-20 alkyl dihydroxyethyl or diethoxyhydroxyethyl methylammonium chloride or methyl sulfate; di(stearoyloxyethyl) dimethylammonium chloride (DSOEDMAC) or methyl sulfate; di(tallow-oxy-ethyl) or di(palm-oxy-ethyl) dimethylammonium chloride or methyl sulfate; monotallow-oxy-ethyl or monopalm-oxy-ethyl, dihydroxyethyl, monomethyl, ammounium chloride or methyl sulfate, ditallow (dipalm) imidazolinium methylsulfate or chloride; ditallow-ethoxy-ethyl or di-palm-ethoxy- ethyl di-ethyl, mono-ethoxy-ethyl methyl ammnonium choloride or methyl sulfate, 1-(2-tallowylamidoethyl)-2-tallowy! imidazolinium methylsulfate, 1-(2- palmitylamidoethyl)-2-palmityl imadazolinium chloride or methyl sulfate and mixtures thereof.

Another type of fabric softening active which can be used in the present invention is a silicone compound. The silicone compounds useful herein include volatile soluble or insoluble, or nonvolatile soluble or insoluble silicone agents. By soluble what is meant is that the silicone compound is miscible with the carrier of the composition so as to form part of the same phase. By insoluble what is meant is that the silicone forms a separate, discontinuous phase from the carrier, such as in the form of an emulsion or a suspension of droplets of the silicone. The silicone compounds herein may be made by any suitable method known in the art, including emulsion polymerization. The silicone compounds may further be incorporated in the present composition in the form of an emulsion, wherein the emulsion is made my mechanical mixing, or in the stage of synthesis through emulsion polymerization, with or without the aid of a surfactant selected from anionic surfactants, nonionic surfactants, cationic surfactants, and mixtures thereof. Silicone compound of high molecular weight may be made by emulsion polymerization. Suitable silicone fluids include polyalkyl siloxanes, polyaryl siloxanes, polyalkylaryl siloxanes, polyether siloxane copolymers, and mixtures thereof.

The silicone compounds herein are preferably used at levels by weight of the composition of from about 0.1% to about 60%, more preferably from about 0.1% to about 40%.

The silicone compounds herein also include polyalkyl or polyaryl siloxanes with the following

wherein R⁹³ is alkyl or aryl, and x is an integer from about 7 to about 8,000. Z⁸ represents groups which block the ends of the silicone chains. The alkyl or aryl groups substituted on the siloxane chain (R⁹³) or at the ends of the siloxane chains Z⁸ can have any structure as long as the resulting silicone remains fluid at room temperature, is dispersible, is compatible with the other components of the composition, and is chemically stable under normal use and storage conditions. Suitable Z⁸ groups include hydroxy, methyl, methoxy, ethoxy, propoxy, and aryloxy. The two R⁹³ groups on the silicon atom may represent the same group or different groups. Preferably, the two R⁹³ groups represent the same group. Suitable R⁹³ groups include methyl, ethyl, propyl, phenyl, methylphenyl and phenylmethyl. The preferred silicone compounds are polydimethylsiloxane, polydiethylsiloxane, and polymethylphenylsiloxane. Polydimethylsiloxane, which is also known as dimethicone, is especially preferred. The polyalkylsiloxanes that can be used include, for example, polydimethylsiloxanes. These silicone compounds are available, for example, from the General Electric Company in their Viscasil® and SF 96 series, and from Dow Corning in their Dow Corning 200 series.

Polyalkylaryl siloxane fluids can also be used and include, for example, polymethylphenylsiloxanes. These siloxanes are available, for example, from the General Electric Company as SF 1075 methyl phenyl fluid or from Dow Corning as 556 Cosmetic Grade Fluid.

Especially preferred, are highly arylated silicone compounds, such as highly phenylated polyethyl silicone having refractive index of about 1.46 or higher, especially about 1.52 or higher. When these high refractive index silicone compounds are used, they should be mixed with a spreading agent, such as a surfactant or a silicone resin, as described below to decrease the surface tension and enhance the film forming ability of the material.

The silicone compounds that can be used include, for example, a polypropylene oxide modified polydimethylsiloxane although ethylene oxide or mixtures of ethylene oxide and propylene oxide can also be used. The ethylene oxide and polypropylene oxide level should be sufficiently low so as not to interfere with the dispersibility characteristics of the silicone. These material are also known as dimethicone copolyols.

Other silicone compounds include amino substituted materials. Suitable alkylamino substituted silicone compounds include those represented by the following structure (II)

wherein R⁹⁴ is H, CH₃ or OH, p¹, p², q¹ and q² are integers which depend on the molecular weight, the average molecular weight being approximately between 5,000 and 10,000. This polymer is also known as "amodimethicone".

Suitable amino substituted silicone fluids include those represented by the formula (III)

(R⁹⁷)_aG₃._a-Si-(OSiG₂)_p3-(OSiG_b(R⁹⁷)₂._b)_p4-O-SiG₃._a(R⁹⁷)_a (III) in which G is chosen from the group consisting of hydrogen, phenyl, OH, C_rC₈ alkyl and preferably methyl; a denotes 0 or an integer from 1 to 3, and preferably equals 0; b denotes 0 or 1 and preferably equals 1 ; the sum p³+p⁴ is a number from 1 to 2,000 and preferably from 50 to 150, p³ being able to denote a number from 0 to 1 ,999 and preferably from 49 to 149 and p⁴ being able to denote an integer from 1 to 2,000 and preferably from 1 to 10; R⁹⁷ is a monovalent radical of formula C_q3H_2q3L in which q³ is an integer from 2 to 8 and L is chosen from the groups

— N(R⁹⁶)CH₂— CH₂— N(R^9δ)

— N(R 9⁹6⁶\)₂ — N(R⁹⁶)₃X'

— N(R⁹⁶)CH₂— CH₂— NR⁹⁶H₂X' in which R⁹⁶ is chosen from the group consisting of hydrogen, phenyl, benzyl, a saturated hydrocarbon radical, preferably an alkyl radical containing from 1 to 20 carbon atoms, and X' denotes a halide ion.

An especially preferred amino substituted silicone corresponding to formula (II) is the polymer known as "trimethylsilylamodimethicone" wherein R⁹⁴ is CH₃. Other amino substituted silicone polymers which can be used are represented by the formula (V):

where R⁹⁸ denotes a monovalent hydrocarbon radical having from 1 to 18 carbon atoms, preferably an alkyl or alkenyl radical such as methyl; R⁹⁹ denotes a hydrocarbon radical, preferably a C C₁₈ alkylene radical or a C,-C₁₈, and more preferably

alkyleneoxy radical; Q^" is a halide ion, preferably chloride; p⁵ denotes an average statistical value from 2 to 20, preferably from 2 to 8; p⁶ denotes an average statistical value from 20 to 200, and preferably from 20 to 50. A preferred polymer of this class is available from Union Carbide under the name "UCAR SILICONE ALE 56."

References disclosing suitable nonvolatile dispersed silicone compounds include U.S. Patent No. 2,826,551 , to Geen; U.S. Patent No. 3,964,500, to Drakoff, issued June 22, 1976; U.S. Patent No. 4,364,837, to Pader; and British Patent No. 849,433, to Woolston. "Silicon Compounds" distributed by Petrarch Systems, Inc., 1984, provides an extensive, though not exclusive, listing of suitable silicone compounds. Another nonvolatile dispersed silicone that can be especially useful is a silicone gum. The term "silicone gum", as used herein, means a polyorganosiloxane material having a viscosity at 25°C of greater than or equal to 1 ,000,000 centistokes. It is recognized that the silicone gums described herein can also have some overlap with the above-disclosed silicone compounds. This overlap is not intended as a limitation on any of these materials. Silicone gums are described by Petrarch, and others including U.S. Patent No. 4,152,416, to Spitzer et al., issued May 1 , 1979 and Noll, Walter, Chemistry and Technology of Silicones, New York: Academic Press 1968. Also describing silicone gums are General Electric Silicone Rubber Product Data Sheets SE 30, SE 33, SE 54 and SE 76. The "silicone gums" will typically have a mass molecular weight in excess of about 200,000, generally between about 200,000 and about 1 ,000,000. Specific examples include polydimethylsiloxane, polydimethylsiloxane methylvinylsiloxane) copolymer, polydimethylsiloxane diphenylsiloxane methylvinylsiloxane) copolymer and mixtures thereof. Also useful are silicone resins, which are highly crosslinked polymeric siloxane systems. The crosslinking is introduced through the incorporation of tri- functional and tetra-functional silanes with mono-functional or di-functional, or both, silanes during manufacture of the silicone resin. As is well understood in the art, the degree of crosslinking that is required in order to result in a silicone resin will vary according to the specific silane units incorporated into the silicone resin. In general, silicone materials which have a sufficient level of trifunctional and tetrafunctional siloxane monomer units, and hence, a sufficient level of crosslinking, such that they dry down to a rigid, or hard, film are considered to be silicone resins. The ratio of oxygen atoms to silicon atoms is indicative of the level of crosslinking in a particular silicone material. Silicone materials which have at least about 1.1 oxygen atoms per silicon atom will generally be silicone resins herein. Preferably, the ratio of oxygen:silicon atoms is at least about 1.2:1.0. Silanes used in the manufacture of silicone resins include monomethyl-, dimethyl-, trimethyl-, monophenyl-, diphenyl-, methylphenyl-, monovinyl-, and methylvinylchlorosilanes, and tetrachlorosilane, with the methyl substituted silanes being most commonly utilized. Preferred resins are offered by General Electric as GE SS4230 and SS4267. Commercially available silicone resins will generally be supplied in a dissolved form in a low viscosity volatile or nonvolatile silicone fluid. The silicone resins for use herein should be supplied and incorporated into the present compositions in such dissolved form, as will be readily apparent to those skilled in the art. Other useful silicone resins are silicone resin powders such as the material given the CTFA designation polymethylsilsequioxane, which is commercially available as Tospearl™ from Toshiba Silicones.

The method of manufacturing these silicone compounds, can be found in Encyclopedia of Polymer Science and Engineering, Volume 15, Second Edition, pp. 204-308, John Wiley & Sons, Inc., 1989.

Silicone materials and silicone resins in particular, can conveniently be identified according to a shorthand nomenclature system well known to those skilled in the art as the "MDTQ" nomenclature. Under this system, the silicone is described according to the presence of various siloxane monomer units which make up the silicone. Briefly, the symbol M denotes the mono-functional unit (CH₃)₃SiO₀₅; D denotes the difunctional unit (CH₃)₂SiO; T denotes the trifunctional unit (CH₃)SiO_{1 5}; and Q denotes the quadri- or tetra-functional unit SiO2. Primes of the unit symbols, e.g., M', D', T', and Q' denote substituents other than methyl, and must be specifically defined for each occurrence. Typical alternate substituents include groups such as vinyl, phenyl, amino, hydroxyl, etc. The molar ratios of the various units, either in terms of subscripts to the symbols indicating the total number of each type of unit in the silicone, or an average thereof, or as specifically indicated ratios in combination with molecular weight, complete the description of the silicone material under the MDTQ system. Higher relative molar amounts of T, Q, T' and/or Q' to D, D', M and/or or M' in a silicone resin is indicative of higher levels of crosslinking. As discussed before, however, the overall level of crosslinking can also be indicated by the oxygen to silicon ratio.

The silicone resins for use herein which are preferred are MQ, MT, MTQ, MQ and MDTQ resins. Thus, the preferred silicone substituent is methyl. Especially preferred are MQ resins wherein the M:Q ratio is from about 0.5:1.0 to about 1.5:1.0 and the average molecular weight of the resin is from about 1000 to about 10,000.

Particularly suitable silicone compounds herein are non-volatile silicone oils having a molecular weight of from about 200,000 to about 600,000 such as Dimethicone, and Dimethiconol. These silicone compounds can be incorporated in the composition as silicone oils solutions; the silicone oils being volatile or nonvolatile. Commercially available silicone compounds which are useful herein include Dimethicone with tradename DC345 available from Dow Corning Corporation, Dimethicone gum solutions with tradenames SE 30, SE 33, SE 54 and SE 76 available from General Electric, Dimethiconol with tradenames DCQ2- 1403 and DCQ2-1401 available from Dow Corning Corporation, and emulsion polymerized Dimethiconol available from Toshiba Silicone as described in GB application 2,303,857. Solvent

A solvent is optionally provided in the fabric care composition described herein. The solvent promotes easy application of the fabric softening active directly onto the target fabric. The solvent also allows the fabric care composition to be evenly applied directly onto a fabric or a portion of a fabric. The solvent useful herein is selected from water, a low molecular weight organic solvent, propylene carbonate, glycerol ethers, and mixtures thereof. The solvent employed in the compositions preferably comprise water due to its low cost, relative availability, safety, and environmental compatibility. If present, the water content in the solvent is generally more than about 50%, preferably more than about 80%, more preferably more than about 85%, by weight of the solvent. The low molecular weight, e.g., less than about 100, organic solvents useful herein include lower alcohols such as C-|_4 monohydric alcohols, dihydric (glycol, etc.) trihydric (glycerol, etc.), and polyhydric (polyols) alcohols, such as C2-6 polyhydric alcohols. Preferably, ethanol, propanol, isopropanol, propylene glycol, glycerol, and mixtures thereof are employed herein. The amount of solvent present in the compositions described herein is generally from about 0.1% to about 30%, preferably from about 1 % to about 30%, and more preferably from about 2% to about 10%, by weight of the fabric care composition. The present compositions may take the form of clear or translucent liquid compositions. In such instances, the solvent preferably is selected to minimize solvent odor impact in the composition and to provide a low viscosity to the final composition. For example, isopropyl alcohol is not very effective and has a strong odor, while n-propyl alcohol is more effective, but also has a distinct odor. Several butyl alcohols also have odors but can be used for effective clarity/stability, especially when used as part of a principal solvent system to minimize their odor. The alcohols are also selected for optimum low temperature stability, that is they are able to form compositions that are liquid with acceptable low viscosity and translucent, preferably clear, down to about 40 °F (about 4.4 °C) and are able to recover after storage down to about 20 °F (about 6.7 °C).

The suitability of any solvent for the formulation of the liquid, preferably clear, fabric care compositions herein with the requisite stability is surprisingly selective. Suitable solvents may be selected based upon their octanol/water partition coefficient (P). Octanol/water partition coefficient of a principal solvent is the ratio between its equilibrium concentration in octanol and in water. The partition coefficients of the principal solvent ingredients of this invention are conveniently given in the form of their logarithm to the base 10, logP. The logP of many ingredients has been reported; for example, the Pomona92 database, available from Daylight Chemical Information Systems, Inc. (Daylight CIS), Irvine, California, contains many, along with citations to the original literature. However, the logP values are most conveniently calculated by the "CLOGP" program, also available from Daylight CIS. This program also lists experimental logP values when they are available in the Pomona92 database. The "calculated logP" (ClogP) is determined by the fragment approach of Hansch and Leo (cf., A. Leo, in Comprehensive Medicinal Chemistry, Vol. 4, C. Hansch, P. G. Sammens, J. B. Taylor and C. A. Ramsden, Eds., p. 295, Pergamon Press, 1990, incorporated herein by reference). The fragment approach is based on the chemical structure of each ingredient, and takes into account the numbers and types of atoms, the atom connectivity, and chemical bonding. These ClogP values, which are the most reliable and widely used estimates for this physicochemical property, are preferably used instead of the experimental logP values in the selection of the principal solvent ingredients which are useful in the present invention. Other methods that can be used to compute ClogP include, e.g., Crippen's fragmentation method as disclosed in J. Chem. Inf. Comput. Sci., 27, 21 (1987); Viswanadhan's fragmentation method as disclose in J. Chem. Inf. Comput. Sci., 29, 163 (1989); and Broto's method as disclosed in Eur. J. Med. Chem. - Chim. Theor., 19, 71 (1984). The solvents herein are selected from those having a ClogP of from about 0.15 to about 0.64, preferably from about 0.25 to about 0.62, and more preferably from about 0.40 to about 0.60, said principal solvent preferably being at least somewhat asymmetric, and preferably having a melting, or solidification, point that allows it to be liquid at, or near room temperature. Solvents that have a low molecular weight and are biodegradable are also desirable for some purposes. The more asymmetric solvents appear to be very desirable, whereas the highly symmetrical solvents such as 1 ,7- heptanediol, or 1 ,4-bis(hydroxymethyl) cyclohexane, which have a center of symmetry, appear to be unable to provide the essential clear compositions when used alone, even though their ClogP values fall in the preferred range.

The most preferred solvents can be identified by the appearance of the fabric softener active vesicles, as observed via cryogenic electron microscopy of the compositions that have been diluted to the concentration used in the rinse.

These dilute compositions appear to have dispersions of fabric softener actives that exhibit a more uni-lamellar appearance than conventional fabric softener compositions. The closer to uni-lamellar the appearance, the better the compositions seem to perform. These compositions provide surprisingly good fabric softening as compared to similar compositions prepared in the conventional way with the same fabric softener active.

Operable solvents are disclosed and listed below which have ClogP values which fall within the requisite range. These include mono-ols, C6 diols, C7 diols, octanediol isomers, butanediol derivatives, trimethylpentanediol isomers, ethylmethylpentanediol isomers, propyl pentanediol isomers, dimethylhexanediol isomers, ethylhexanediol isomers, methylheptanediol isomers, octanediol isomers, nonanediol isomers, alkyl glyceryl ethers, di(hydroxy alkyl) ethers, and aryl glyceryl ethers, aromatic glyceryl ethers, alicyclic diols and derivatives, C3C7 diol alkoxylated derivatives, aromatic diols, and unsaturated diols. Particularly preferred solvents include hexanediols such as 1 ,2-Hexanediol and 2-Ethyl-1 ,3-hexanediol and pentanediols such as 2,2,4- Trimethyl-1 ,3-pentanediol. These solvents are all disclosed as "principal solvents" in U.S. Patent application numbers 08/621 ,019; 08/620,627; 08/620,767; 08/620,513; 08/621 ,285; 08/621 ,299; 08/621 ,298; 08/620,626; 08/620,625; 08/620,772; 08/621 ,281 ; 08/620,514; and 08/620,958, all filed March 22, 1996 and all having the title "CONCENTRATED, STABLE, PREFERABLY CLEAR, FABRIC SOFTENING COMPOSITION". Adjunct Materials The balance of the fabric care composition is comprised of adjunct materials. Any such materials may be useful herein as long as they do not reduce or eliminate the benefits provided by any previously-used fabric softening actives. For example, such adjunct materials may include perfumes, surfactants, deodorants, silicones, pH buffers, dyes, optical brighteners, viscosity/dispersibility modifiers, stabilizers, and mixtures thereof.

Surfactants are typically selected from the group consisting of single long chain alkyl cationic surfactants; nonionic surfactants; amine oxides; fatty acids; or mixtures thereof, typically used at a level of from 0% to about 15% of the composition. In addition, the compositions of the present invention may include less than about 10% by weight of an amphoteric surfactant. Preferably, the compositions include less than about 5% and more preferably less than about 3% by weight of an amphoteric surfactant.

The fabric care composition may also contain one or more commonly known pH buffers to maintain the composition at a constant pH during storage and use.

Certain dyes may also be useful herein and may be easily purchased throughout the world; however care should be taken to avoid dyes or dye levels which may stain or otherwise discolor the fabrics to be treated.

Optical brighteners may also be present herein. Commercial optical brighteners which may be useful in the present invention can be classified into subgroups, which include, but are not necessarily limited to, derivatives of stilbene, pyrazoline, coumarin, carboxylic acid, methinecyanines, dibenzothiphene-5,5-dioxide, azoles, 5- and 6-membered-ring heterocycles, and other miscellaneous agents. Examples of such optical brighteners are disclosed in "The Production and Application of Fluorescent Brightening Agents", M. Zahradnik, Published by John Wiley & Sons, New York (1982). Specific examples of optical brighteners which are useful in the present fabric care composition are those identified in U.S. Patent 4,790,856, issued to Wixon on December 13, 1988. These brighteners include the PHORWHITE™ series of brighteners from Verona. Other brighteners disclosed in this reference include: Tinopal UNPA, Tinopal CBS and Tinopal 5BM; available from Ciba-Geigy; Artie White CC and Artie White CWD, available from Hilton-Davis, located in Italy; the 2-(4-stryl-phenyl)-2H-napthol[1 ,2-d]triazoles; 4,4'-bis- (1 ,2,3-triazol-2-yl)- stilbenes; 4,4'-bis(stryl)bisphenyls; and the aminocoumarins. Specific examples of these brighteners include 4-methyl-7-diethyl- amino coumarin; 1 ,2-bis(- venzimidazol-2-yl)ethylene; 1 ,3-diphenyl-phrazolines; 2,5-bis(benzoxazol-2- yl)thiophene; 2-stryl-napth-[1 ,2-d]oxazole; and 2-(stilbene-4-yl)-2H-naphtho- [1 ,2- djtriazole. See also U.S. Patent 3,646,015, issued February 29, 1972 to Hamilton. Anionic brighteners are preferred herein. Viscosity/dispersability modifiers can be added for the purpose of facilitating the solubilization and/or dispersion, concentration, and/or improving phase stability (e.g., viscosity stability). Some preferred dispersibility modifiers may include: (A) Nonionic Surfactant (Alkoxylated Materials)

Suitable nonionic surfactants to serve as the viscosity/dispersability modifier include addition products of ethylene oxide and, optionally, propylene oxide, with fatty alcohols, fatty acids, fatty amines, etc. They are referred to herein as ethoxylated fatty alcohols, ethoxylated fatty acids, and ethoxylated fatty amines.

Any of the alkoxylated materials of the particular type described hereinafter can be used as the nonionic surfactant. In general terms, the nonionic herein, when used alone, are at a level of from 0% to about 5%, preferably from about 0.1% to about 5%, more preferably from about 0.2% to about 3%. Suitable compounds are substantially water-soluble surfactants of the general formula:

R² - Y - (C₂H₄O)_z - C₂H₄OH wherein R² is selected from the group consisting of primary, secondary and branched chain alkyl and/or acyl hydrocarbyl groups; primary, secondary and branched chain alkenyl hydrocarbyl groups; and primary, secondary and branched chain alkyl- and alkenyl-substituted phenolic hydrocarbyl groups; said hydrocarbyl groups having a hydrocarbyl chain length of from about 8 to about 20, preferably from about 10 to about 18 carbon atoms. More preferably the hydrocarbyl chain length is from about 16 to about 18 carbon atoms. In the general formula for the ethoxylated nonionic surfactants herein, Y is typically -O-, -C(O)O-, -C(O)N(R)-, or -C(O)N(R)R-, preferably -O-, and in which R², and R, when present, have the meanings given herein before, and/or R can be hydrogen, and z is at least about 8, preferably at least about 10-11. Performance and, usually, stability of the softener composition decrease when fewer ethoxylate groups are present.

The nonionic surfactants herein are characterized by an HLB (hydrophilic-lipophilic balance) of from about 7 to about 20, preferably from about 8 to about 15. Of course, by defining R² and the number of ethoxylate groups, the HLB of the surfactant is, in general, determined. However, it is to be noted that the nonionic ethoxylated surfactants useful herein, for concentrated liquid compositions, contain relatively long chain R² groups and are relatively highly ethoxylated. While shorter alkyl chain surfactants having short ethoxylated groups can possess the requisite HLB, they are not as effective herein.

Nonionic surfactants as the viscosity/dispersability modifiers are preferred over the other modifiers disclosed herein for compositions with higher levels of perfume. Examples of nonionic surfactants follow. The nonionic surfactants of this invention are not limited to these examples. In the examples, the integer defines the number of ethoxy (EO) groups in the molecule.

(B) Straight-Chain, Primary Alcohol Alkoxylates

The deca-, undeca-, dodeca-, tetradeca-, and pentadecaethoxylates of n-hexadecanol, and n-octadecanol having an HLB within the range recited herein are useful viscosity/dispersability modifiers in the context of this invention.

Exemplary ethoxylated primary alcohols useful herein as the viscosity/dispersability modifiers of the compositions are n-C-j sEO(10); and n-C-|oEO(11). The ethoxylates of mixed natural or synthetic alcohols in the "tallow" chain length range are also useful herein. Specific examples of such materials include tallow alcohol-EO(11), tallow alcohol-EO(18), and tallow alcohol -EO(25).

(C) Straight-Chain. Secondary Alcohol Alkoxylates

The deca-, undeca-, dodeca-, tetradeca-, pentadeca-, octadeca-, and nonadeca-ethoxylates of 3-hexadecanol, 2-octadecanol, 4-eicosanol, and

5-eicosanol having and HLB within the range recited herein are useful viscosity/dispersability modifiers in the context of this invention. Exemplary ethoxylated secondary alcohols useful herein as the viscosity/dispersability modifiers of the compositions are: 2-C-|6EO(11); 2-C2θEO(11); and 2 -C ₆EO(14).

(D) Alkyl Phenol Alkoxylates As in the case of the alcohol alkoxylates, the hexa- through octadeca-ethoxylates of alkylated phenols, particularly monohydric alkylphenols, having an HLB within the range recited herein are useful as the viscosity/dispersability modifiers of the instant compositions. The hexa- through octadeca-ethoxylates of p-tridecylphenol, m-pentadecylphenol, and the like, are useful herein. Exemplary ethoxylated alkylphenols useful as the viscosity/dispersability modifiers of the mixtures herein are: p-tridecylphenol EO(11) and p-pentadecylphenol EO(18).

As used herein and as generally recognized in the art, a phenylene group in the nonionic formula is the equivalent of an alkylene group containing from 2 to 4 carbon atoms. For present purposes, nonionics containing a phenylene group are considered to contain an equivalent number of carbon atoms calculated as the sum of the carbon atoms in the alkyl group plus about 3.3 carbon atoms for each phenylene group. (E) Olefinic Alkoxylates

The alkenyl alcohols, both primary and secondary, and alkenyl phenols corresponding to those disclosed immediately hereinabove can be ethoxylated to an HLB within the range recited herein and used as the viscosity/dispersability modifiers of the instant compositions. (F) Branched Chain Alkoxylates

Branched chain primary and secondary alcohols which are available from the well-known "OXO" process can be ethoxylated and employed as the viscosity/dispersability modifiers of compositions herein.

The above ethoxylated nonionic surfactants are useful in the present compositions alone or in combination, and the term "nonionic surfactant" encompasses mixed nonionic surface active agents. (G) Mixtures

The term "mixture" includes the nonionic surfactant and the single-long-chain-alkyl cationic surfactant added to the composition in addition to any monoester present in the DEQA.

Mixtures of the above viscosity/dispersability modifiers are highly desirable. The single long chain cationic surfactant provides improved dispersibility and protection for the primary DEQA against anionic surfactants and/or detergent builders that are carried over from the wash solution. The viscosity/dispersability modifiers are present at a level of from about 0.1 % to about 30%, preferably from about 0.2% to about 20%, by weight of the composition.

Stabilizers can be present in the compositions of the present invention. The term "stabilizer," as used herein, includes antioxidants and reductive agents both of which are well-known in the art. These agents are present at a level of from 0% to about 2%, preferably from about 0.01 % to about 0.2%, more preferably from about 0.035% to about 0.1% by weight of the composition for antioxidants, and more preferably from about 0.01% to about 0.2% by weight of the composition for reductive agents. These assure good odor stability under long term storage conditions for the compositions and compounds stored in molten form. The use of antioxidants and reductive agent stabilizers is especially desirable for low scent products (low perfume).

Other preferred optional ingredients include, but are not limited to, dye transfer inhibiting agents, polymeric dispersing agents, suds suppressers, optical brighteners or other brightening or whitening agents, dye fixing agents, light fading protection agents, oxygen bleach protection agents, fabric softening clay, anti-static agents, other active ingredients, carriers, hydrotropes, processing aids, dyes or pigments, bacteriocides, colorants, perfumes, preservatives, opacifiers, anti-shrinkage agents, anti-wrinkle agents, fabric crisping agents, spotting agents, germicides, fungicides, anti-corrosion agents.

The fabric care composition as described herein is intended for applying directly onto the fabric, or can be applied to the wash cycle, the rinse cycle, or to the drying cycle.

Examples of the invention are set forth hereinafter by way of illustration and are not intended to be in any way limiting of the invention.

EXAMPLE A

Fabric care compositions of the present invention have the following formulations:

* solvent = deionized water

** solvent = propylene glycol and deionized water. t solvent = glycerol and water

EXAMPLE B Fabric care compositions of the present invention have the following formulations:

* MTTMAC = monotallow trimethyl ammonium chloride *^*solvent = 1 ,2-hexane diol and deionised water ***solvent = ethylhexanedeol **^**solvent = deionised water

Claims

What is claimed is:

1. A fabric care composition comprising a fabric softening active and a protein, wherein from about 20% to about 40% of the amino acid in the primary structure of the protein is serine, and wherein the pH of the fabric care composition is less than 7 at 25°C.

2. The fabric care composition according to Claim 1 , wherein the protein is sericin.

3. The fabric care composition according to Claim 1 , wherein the pH is from about 2 to about 6.5 at 25°C.

4. The fabric care composition according to Claim 2, comprising from about 0.05% to about 50% by weight of sericin.

5. The fabric care composition according to Claim 2, wherein the molecular weight of the sericin is from about 1 kDa (Kilo Dalton) to about 400 kDa.

6. A fabric care composition comprising:

(a) from about 1% to about 70% by weight of a fabric softening active;

(b) from about 0.1% to about 30% by weight of a solvent; and (b) from about 0.05% to about 50% by weight of sericin, wherein the pH of the detergent composition is less than 7 at 25°C.

7. The fabric care composition according to Claim 6, further comprising adjunct ingredients selected from the group consisting of perfumes, surfactants, deodorants, pH buffers, dyes, optical brighteners, viscosity/dispersability modifiers, stabilizers, soil release agent, enzymes, and mixtures thereof.

8. The fabric care composition according to Claim 6, wherein the fabric softening active is selected from the group consisting of quaternary ammonium compounds or amine precursors thereof, cationic ammonium softening compounds, nonionic softening compounds, and mixtures thereof.

9. The fabric care composition according to Claim 6, wherein the solvent is selected from the group consisting of water, a low molecular weight organic solvent, propylene carbonate, glycerol ethers, and mixtures thereof.

0. The fabric care composition according to Claim 8, wherein the fabric softening active is selected from the group consisting of ditallow or dipalmityl dimethylammonium chloride or methyl sulfate (DTDMAC); dihydrogenated tallow (palm) dimethylammonium chloride; dihydrogenated tallow (palm) dimethylammonium methylsulfate; distearyl dimethylammonium chloride; dioleyl dimethylammonium chloride or methyl sulfate; dipalmityl hydroxyethyl methylammonium chloride or methyl sulfate; stearyl benzyl dimethylammonium chloride or methyl sulfate; tallow (palm) trimethylammonium chloride or methyl sulfate; hydrogenated tallow (palm) trimethylammonium chloride or methyl sulfate; C<i2"20 ^a'M ethoxyhydroxyethyl or hydroxyethyl dimethylammonium chloride or methyl sulfate; Di-Ci2-20 alkyl dihydroxyethyl or diethoxyhydroxyethyl methylammonium chloride or methyl sulfate; di(stearoyloxyethyl) dimethylammonium chloride (DSOEDMAC) or methyl sulfate; di(tallow-oxy- ethyl) or di(palm-oxy-ethyl) dimethylammonium chloride or methyl sulfate; monotallow-oxy-ethyl or monopalm-oxy-ethyl, dihydroxyethyl, monomethyl, ammounium chloride or methyl sulfate, ditallow (dipalm) imidazolinium methylsulfate or chloride; ditallow-ethoxy-ethyl or dipalm-ethoxy-ethyl di-ethyl, mono-ethoxy-ethyl methyl ammnonium choloride or methyl sulfate, 1-(2- tallowylamidoethyl)-2-tallowyl imidazolinium methylsulfate, 1-(2- palmitylamidoethyl)-2-palmityl imadazolinium chloride or methyl sulfate and mixtures thereof.