WO2000058427A1

WO2000058427A1 - Softener compositions having high hydrolytic stability concentratibility

Info

Publication number: WO2000058427A1
Application number: PCT/US2000/007970
Authority: WO
Inventors: Pierre M. Lenoir; Johannes W. F. Spitzen; Kees Delcour; Marinus Meertens
Original assignee: The Dow Chemical Company
Priority date: 1999-03-26
Filing date: 2000-03-24
Publication date: 2000-10-05
Also published as: AU3773100A; EP1171558A1

Abstract

The invention relates to new formulations comprising esterquats and amides, and their use in detergent, fabric softening, dryer sheets, personal care applications and cleaners having improved hydrolytic stability and concentratibility. The invention also relates to an improved process for making these formulations where unreacted fatty acid used in the esterification step is reacted with an amine to form the amide in situ. This improved process offers the advantages of reducing total reaction time, providing an amide that stabilizes the formulation and eliminating free fatty acid that can hurt the stability of the formulation.

Description

SOFTENER COMPOSITIONS HAVING HIGH HYDROLYTIC STABILITY CONCENTRAΗBILITY

FIELD OF THE INVENTION

The invention relates to new formulations comprising esterquats and amides, and their use in detergent, fabric softening, dryer sheets, personal care and cleaners. The invention also relates to an improved process for making these formulations where unreacted fatty acid used in the esterification step is reacted with an amine to form the amide in situ. This improved process offers the advantages of reducing total reaction time, providing an amide that stabilizes the formulation and eliminating free fatty acid that can hurt the stability of the formulation.

Compositions containing quaternary ammonium salts having at least one long chain esterified hydrocarbyl group ("esterquats") are widely known for their use in laundry (for example, fabric softeners, dryer sheets, softergents, detergents), cleaner and personal care applications. These esterquats are known for their efficacy in cleaning and softening applications, but it is also widely recognized that the esterquat formulations that were previously known suffered from hydrolytic stability problems. These problems may bring limitations to their use in aqueous formulations and can be problematical even in solid formulations, if the product is used in an aqueous environment and breaks down before the esterquat has a chance to act on the target surface.

Recently, several efforts to improve the hydrolytic stability of esterquats have been reported. These efforts have primarily focused on manipulating the chemical structure of the esterquat. For example, in EP 0 869 114 A1 , it is taught that esterquats can be made more hydrolytically stable through the incorporation of alkylene oxide groups. Similarly, in UK patent application 9816659.8 (filed 30 July, 1998), it was reported that increased hydrolytic stability could be achieved by esterifying secondary or tertiary alcohols, rather than all primary. While these solutions are beneficial, it would also be advantageous to improve the hydrolytic stability of formulations that contain esterquats that are already known and are currently in use.

An improved process to make esterquat formulations is also sought. These esterquats are typically formed by reacting an alkanolamine with a fatty acid. The fatty acid reacts with the OH group forming an ester amine and releasing water. The ester amine can then be quaternized as is known in the art. One potential lengthy step in this process is the esterification reaction, which can take more than 24 hours to fully react the alkanolamine with a stoichiometric amount of fatty acid. The amount of time needed to complete the reaction is directly correlated with the cost of the process. Two approaches are commonly used in such situations in order to decrease the time and therefore the cost of the process. The first is the use of excess fatty acid. Excess fatty acid can cause the alkanolamine to react more quickly, but it has been discovered that the remaining unreacted free fatty acid may cause chemical stability problems, as well as decrease hydrolytic stability. In fact, it has been discovered that free fatty acid is a source of some of the hydrolytic stability problems previously associated with esterquat formulations. Fatty acid also increases the viscosity if the formulation which can negatively impact the formulations ability to be used in consumer applications. The free fatty acid can be removed by traditional separation techniques, but such procedures add expense to the process, thereby cancelling out the benefits gained from using excess acid in the first place. The second approach is to just stop the reaction before it reaches completion.

The esterification reaction follows the common pattern where the concentration of the reactants asymptotically approaches zero. Thus, the majority of the starting material is consumed in the early stages of the reaction whereas the last percentages of starting material take comparatively longer to react. However, stopping the reaction before it reaches completion again leads to the presence of unreacted fatty acid, which as previously discussed is problematical.

Accordingly, there is also a need to develop a faster process to make esterified alkanolamines, which does not result in the presence of unreacted fatty acid in the mixture. It has been found that the presence of an amide in an esterquat formulation improves the hydrolytic stability of the formulation. Equally surprising, it has been discovered that the presence of amides allows higher concentrations of the esterquat than typically available, due to the formulations becoming too viscous to be easily poured. This amide may be added separately, after either the esterification step or the quaternization step, but more preferably, it is formed in situ, by adding an amine to a reaction mixture containing unreacted fatty acid. So in a typical esterification reaction, the alkanolamine and the fatty acid (whether in a stoichiometric amount or excess) would be allowed to react for a period of time and then a reactive amine would be added. This amine would react with the fatty acid that had not yet formed an ester to produce an amide. The particular amine used is not essential to the basic, unoptimized function of the invention so long as it is able to react with the fatty acid. Thus, this in situ process meets two of the needs previously identified: it eliminates unwanted fatty acid without long reaction times and it produces an amide which can be used in the formulation.

It has also been discovered that the presence of the amide does not necessarily increase the viscosity of aqueous esterquat based formulations despite the fact that amides, such as diethanolamides (based on fatty acids), are known for their use as thickeners. In fact, it has surprisingly been discovered that the presence of an amide may actually decrease the viscosity of such formulations.

It has been found that formulations of the present invention whether or not formed in situ, exhibit excellent hydrolytic stability and often have improved viscosity profiles and are therefore particularly well suited for use in detergent, fabric softening, cleaner, dishwashing and personal care applications. Thus in one aspect, the invention is a composition of matter comprising an esterquat and an amide and having salts of primary fatty amines present in an amount no greater than 5 percent of the esterquat, by weight. The esterquat corresponds to the following formula:

[NR¹R²R²A]⁺ X wherein X is a softener compatible anion;

A is independently at each occurrence [CH₂]_-[CYR³]_m-CYR³H; Y is independently at each occurrence H, OH, N(R )₂ or QT; Q is independently at each occurrence -O-C(O)-; -C(O)-O-; O-C(O)-O-; NR⁴C(O)-; -C(O)NR⁴-; (O-CH₂-CHR³)_p-O-C(O)-; or (O-CH₂-CHR³)_p-C(O)-O-

T is independently at each occurrence a C₅-C₃₅ alkyl group; R¹ is independently at each occurrence a C,-C₄ alkyl group, or an aryl group having 6-12 carbons, optionally substituted with an alkyl group, or an hydroxyalkyl group having 2 to 6 carbons; R² is independently at each occurrence R¹ or A;

R³ is independently at each occurrence H or R¹; R⁴ is independently at each occurrence H or R¹ or a C,-C₄ hydroxyalkyl group; n is independently at each occurrence a number equal to 1 or greater; m is independently at each occurrence a number from 0 to 5; p is independently at each occurrence a number from 1 to 10; with the proviso that at least one Y is QT and at least one Q contains an ester group.

The amide will correspond to the following formula:

(J)(J)N[-P-N(Z)]_m,-(J) where: J is independently at each occurrence -(CH₂-CHR⁵-O)_-R⁶ or -C_n,H_(2n,₊₁._x)(OR⁸)_x;

Z is independently at each occurrence J or [-P-N(J)(J)] ; P is independently at each occurrence -C₂.₁₂ hydrocarbyl or -C_n.H_(2n,_.x)(R⁹)_x-;

R⁵ is independently at each occurrence H or a C_{1 4} alkyl;

R⁶ is independently at each occurrence H, C_{1 20} alkyl or (-C(O)R⁷) ;

R⁷ is independently at each occurrence a C_5.35 alkyl;

R⁸ is independently at each occurrence R⁶ or (-CH₂-CHR⁵-O)_a-R⁶; R⁹ is independently at each occurrence -OR⁸ or -N(R⁸)(R⁸) ; a is independently at each occurrence 0 to 30; x is independently at each occurrence 0 to 6; m' is independently at each occurrence 0 to 10; n' is independently at each occurrence 2 to 6; with the proviso that there is at least one (-C(O)R⁷) present and connected directly to a nitrogen atom.

In a second aspect of the invention, the invention comprises an improved esterification reaction, or indeed, an improvement for any reaction that uses a fatty acid and which would benefit from the removal of unreacted or excess fatty acid. In particular, the improved process of the invention is suitable for those reactions that comprise reacting a species having a reactive H (typically OH or NH groups) with a fatty acid. For example, in a known esterification reaction comprising contacting an alkanolamine having reactive OH groups with a fatty acid to convert at least a portion of the reactive OH groups into esters, the esterification reaction is allowed to continue for a period of time and then an amine is added to react with at least a portion of the fatty acid which has not yet reacted with the alkanolamine. Similar procedures could be used for example in a reaction of an amine with a fatty acid to form an amide, wherein after a period of time a second amine is added which reacts faster than the first amine to quickly eliminate the unreacted or excess fatty acid. Suitable amines in such a process will corresponds to the formula: (J)(J)N[-P-N(Z)]_m,-(J) where: J is independently at each occurrence -(CH₂-CHR⁵-O)_a-R⁶ or -C_,H_(2n,_+1.x)(OR⁸)_x;

Z is independently at each occurrence J or [-P-N(J)(J)]

P is independently at each occurrence -C_{2 12} hydrocarbyl or -C_,H_(2n,_x)(R⁹)_x-; R⁵ is independently at each occurrence H or a C_{1 4} alkyl;

R⁶ is independently at each occurrence H, C, ₂₀ alkyl or (-C(O)R⁷) ;

R⁷ is independently at each occurrence a C_5.35 alkyl;

R⁸ is independently at each occurrence R⁶ or (-CH₂-CHR⁵-O)_a-R⁶; R⁹ is independently at each occurrence -OR⁸ or

-N(R⁸)(R⁸) ; a is independently at each occurrence 0 to 30; x is independently at each occurrence 0 to 6; m' is independently at each occurrence 0 to 10; n' is independently at each occurrence 2 to 6; with the proviso that there is at least one H connected directly to a nitrogen atom which is capable of reacting with a fatty acid to form an amide.

A third aspect of the invention is a process of improving the concentratibility or hydrolytic stability of an esterquat based fabric softener composition, comprising including an amount of an amide to the composition, wherein the amide is defined as above and may be formed in situ or added separately. Yet another aspect of the invention is the use of the compositions described above, whether or not made by using the process described above, in detergents, softergents, fabric softeners, dryer sheets, cleaners or personal care applications.

As previously stated one aspect of the present invention is a composition of matter comprising an esterquat and an amide. Esterquats suitable for use in the present invention correspond to the following formula:

[NR¹R²R²A]⁺ X wherein X is a softener compatible anion; A is independently at each occurrence [CH₂]_n- [CYR³]_m-CYR³H; Y is independently at each occurrence H, OH, N(R⁴)₂or QT; Q is independently at each occurrence -O-C(O)-; -C(O)-O-; O-C(O)-O-; NR⁴C(O)-; -C(O)NR⁴-; (O-CH₂-CHR³)_p-O-C(O)-; or (O-CH₂-CHR³)_p-C(O)-O-; T is independently at each occurrence a C--C₃₅ alkyl group; R¹ is independently at each occurrence a C,-C₄ alkyl group, or an aryl group having 6 to 12 carbons, optionally substituted with an alkyl group, or an hydroxyalkyl group having 2 to 6 carbons; R² is independently at each occurrence R¹ or A; R³ is independently at each occurrence H or R¹; R⁴ is independently at each occurrence H or R¹ or a C_t-C₄ hydroxyalkyl group; n is independently at each occurrence a number equal to 1 or greater; m is independently at each occurrence a number from 0 to 5; and p is independently at each occurrence a number from 1 to 10; with the proviso that at least one Y is QT and at least one Q contains an ester group.

Accordingly, many variations of the esterquat are intended to be within the scope of this invention. In fact, it is believed that the present invention is suitable for any species having an ester group connected, to a quaternized nitrogen atom. It is possible, however, that the esterquat may have two or more nitrogen atoms, may have two or more ester groups, may be alkoxylated (for example by random or block addition of one or more of ethylene oxide, propylene oxide or butylene oxide), may have free OH groups which have not been esterified, may have three short chain (C ) hydrocarbyl groups or only one. It is preferred that when p is present that it is not greater than 3. The T group(s) can be selected from saturated and unsaturated species and may be straight or branched, and can be long or short, although the range of C_7.23 is preferred.

The esterquats for use in the present invention can be purchased, or be synthesized by any means known to those skilled in the art, as the particular process used is not important in this aspect of the invention. Typically the process involves first esterifying an alkanolamine and then totally or partially quatemizing the esterification product. Any reaction conditions conducive to forming an ester can be used. These conditions tend to be at a temperature of from 50°C to 300°C, and at a pressure of from 0.01 atm to about 10 atm. These reactions may be conducted under a blanket of inert gas such as nitrogen. The fatty acid chosen to esterify the alkanolamine can be selected from any C_6.36 fatty acid capable of reacting with an OH group. For purposes of the invention "fatty acid" shall be understood to mean those compounds corresponding to the formula: R⁷C(O)OH where R⁷ is a C_5.35 alkyl group. It is preferred that the fatty acid have from 6 to 24 carbons. The hydrocarbyl chain of the fatty acid can be linear or branched, saturated or unsaturated. The following list demonstrates some alkanolamines which can be esterified

(for example with Radiacid™406, Radiacid™ 409, Radiacid™ 600, or Radiacid™ 626) and which can then be quaternized (for example with DMS or MeCI) optionally in solvents such as IPA and which may be suitable for use in the current invention (Radiacid™ 406 is a material consisting primarily of partially hydrogenated C₁₆-C₁₈ fatty acids; Radiacid™ 409 is a material consisting primarily of fully saturated C₁₆-C₁₈ fatty acids; Radiacid™ 600 is a material consisting primarily of C₁₂-C₁₆ fatty acids (topped coconut); Radiacid™ 626 is a material consisting primarily of C₆-C₁₆ fatty acids (coconut); DMS is dimethylsulfate; MeCI is methyichloride; IPA is isopropanol): TEA (triethanolamine); DEA-1 PO (1-bis(2- hydroxyethyl)amino-2-propanol); DEA-1BO (1-bis(2-hydroxyethyl)amino-2-butanol); DMAE (2-(dimethylamino)ethanol); DMAP (1-(dimethylamino)-2-propanol); DMAPD (3- (dimethylamino)-l ,2-propanediol); MAE-1 PO (N-methyl-(2-hydroxyethyl)-(2- hydroxypropyl)amine); MAE-1 BO (N-methyl-(2-hydroxyethyl)-(2-hydroxybutyl)amine); MDEA (methyldiethanolamine); MDIPA (methyldiisopropanolamine); MEA-2PO (2-bis(2- hydroxypropyl)aminoethanol); TIPA (triisopropanolamine); and their alkoxylates with EO, PO and BO (EO is ethylene oxide or oxirane; PO is propylene oxide; and BO is butyleneoxide) or alkoxylates of the following amines: MAE (N-methyl-2-aminoethanol); MIPA (monoisopropanolamine); MEA (monoethanolamine); TETA (triethylenetetraamine); TEPA (tetraethylenepentamine); AEEA (aminoethylethanolamine); DEA (diethanolamine); DIPA (diisopropanolamine); EDA (ethylenediamine); DETA (diethylenetriamine); and Ammonia. This list is exemplary only and is not meant to be exhaustive.

Similarly, the following list demonstrates some of the fatty acids which can be used, either alone or in combination with other fatty acids, to esterify the alkanolamine which can then be quaternized to some degree and used in the compositions of the invention: valeric acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, and the branched (for example isovaleric acid) or unsaturated isomers (for example oleic acid) thereof. As before, this list is exemplary and not exhaustive, and the person of ordinary skill in the art will understand that there are many other fatty acids or blends of fatty acids not listed here that may be suitable for use with the invention.

Quaternization of alkanolamine esters to make the final esterquat product, is also a known process, and in general any of the many teachings on this subject are applicable in this invention. It is conceived that the quaternization will involve the reaction of the alkanolamine ester with a composition corresponding to the formula R¹X, where R and X are as described above. The quaternization reaction is preferably carried out at the ratio of from 0.1 to 20 moles of R'X per mole of esterified alkanolamine. The temperature is typically from 30°C to 150°C, and at a pressure of from 1 to 50 bars. Suitable quaternizing agents include alkyl halides, dialkyl sulfates, and trialky phosphates. Some preferred alky halides are methyl chloride, ethyl chloride, benzyl chloride, methyl bromide, and ethyl bromide. Preferred dialkyl sulfates include dimethyl sulfate and diethyl sulfate. Preferred trialkyl phosphates include trimethyl phosphate and triethyl phosphate. As is known in the art, it may be advantageous to carry out the quaternization reaction in the presence of a defoaming agent and/or an additive to lower the melting point of the reaction mixture. Commonly known materials include water, isopropanol, propanediol, dipropylene glycol, polyethylene glycol, polypropylene glycol, alkoxylated fatty acids and alcohols having more than three carbons in the alkyl chain, glycol ether solvents, diether solvents, tetrahydrofuran, methanol, ethanol, hexanediol, and acetone.

The particular amide that is in the formulation with the esterquat can also be chosen from a large list of candidates. These amides will have the formula:

(J)(J)N[-P-N(Z)]_m,-(J) where: J is independently at each occurrence -(CH₂-CHR⁵-O)_a-R⁶ or -C_n,H_(Zn._+1.x)(OR⁸)_x; Z is independently at each occurrence J or [-P-N(J)(J)]; P is independently at each occurrence - C₂.₁₂ hydrocarbyl or -C_,H₍₂_,_.X)(R⁹)_X-; R⁵ is independently at each occurrence H or a C,_.4 hydrocarbyl; R⁶ is independently at each occurrence H, C_{1 20} alkyl or (-C(O)R⁷); R⁷ is independently at each occurrence a C_5.3_ alkyl; R⁸ is independently at each occurrence R⁶ or (-CH₂-CHR⁵-O)_a-R⁶; R⁹ is independently at each occurrence -OR⁸ or -N(R⁸)(R⁸); a is independently at each occurrence 0 to 30; x is independently at each occurrence 0 to 6; m' is independently at each occurrence 0 to 10; n' is independently at each occurrence 2 to 6; with the proviso that there is at least one (-C(O)R⁷) present and connected directly to a nitrogen atom. Essentially, therefore, any species which has an R⁷C(O)N group can be used. R⁷ can be saturated or unsaturated, straight or branched, and can be long or short, although the range of C₇₂₃ is preferred. It should be noted that R⁷ may be the same as T in the esterquat but is not necessarily so. It is preferred that R⁵ be H or a C_{1 2} hydrocarbyl; R⁶ be -C(O)C₆.₁₉; x be either 0 or 1 ; P is a C₂₆ hydrocarbyl group; a be from 0 to 10, and m' be from 0 to 5.

The amides suitable for use in the present invention can be purchased commercially, or be made according to methods known by those skilled in the art, such as the ones described in the following references: The Aikanolamines Handbook published by The Dow Chemical Company (Form No. 111-1159-88R-SAI) and the references cited therein; Houben-Weyl, Methoden der Organischen Chemie, band 6, Thieme 1952, Surfactant Science Series Vol. 1 , Nonionic Surfactants, M. Schick, and McKenna, Arthur L., Fatty amides: synthesis, properties, reactions, and applications, Witco Chemical Corporation, Humko Chemical Division, 1982. More preferably the amides can be made in situ in the esterification reaction mixture. It is generally preferred that if the amide is not made in situ (that is, it is purchased or synthesized separately), it is added to the finished quaternized alkanolamine ester, however, it can be added at any stage in the synthesis of the alkanolamine esterquat. If added before the synthesis is complete it should be understood, that a portion of the amide might be reacted as a side reaction with the intended reaction, which may or may not cause problems depending on the intended application.

For example, suitable amides which can be used in the current invention can be made from the amines and acids listed below and which can optionally be further alkoxylated with EO, PO or BO. These examples are exemplary only and are not meant to be exhaustive:

MAE, MIPA, MEA, Dimethylamine, TETA, TEPA, AEEA, DEA, DIPA, EDA, DETA, Radiacid™406, Radiacid™ 409, Radiacid™ 600, and Radiacid™ 626.

As previously stated, however, it is preferred that the amide be formed in situ. This can be done simply by adding an amine to the esterification reaction at a point where there is still unreacted fatty acid in the reaction mixture. Thus, this can be done under the same reaction conditions as the esterification reaction, or alternatively, as the reaction mixture is cooled as is typically done prior to quaternization. It should be understood that if the amide is formed prior to or during quaternization, then some of the amide might also be quaternized. As should be readily understood by those skilled in the art, when the amide is formed in situ with the esterified alkanolamine, then T will be the same as R⁷, as both T and R⁷ will be the residual portion of the same fatty acid.

The amine that may be added to the esterification reaction in the in situ formation corresponds to the amide formula described above, with the same preferences. Hence, they will correspond to the formula:

(J)(J)N[-P-N(Z)]_m,-(J) where: J is independently at each occurrence -(CH₂-CHR⁵-O)_a-R⁶ or -C_n,H_(2n,_+1.x)(OR⁸)_x; Z is independently at each occurrence J or [-P-N(J)(J)]; P is independently at each occurrence - C₂.₁₂ hydrocarbyl or -C_n,H_(2n,_.x)(R⁹)_x-; R⁵ is independently at each occurrence H or a C,_.4 hydrocarbyl; R⁶ is independently at each occurrence H, C._.2. alkyl or

(-C(O)R⁷); R⁷ is independently at each occurrence a C₅₃₅ alkyl; R⁸ is independently at each occurrence R⁶ or (-CH₂-CHR⁵-O)_a-R⁶; R⁹ is independently at each occurrence -OR⁸ or -N(R⁸)(R⁸); a is independently at each occurrence 0-30; x is independently at each occurrence 0 to 6; m' is independently at each occurrence 0 to 10; n' is independently at each occurrence 2 to 6; with the proviso that there is at least one H connected directly to a nitrogen atom which is capable of reacting with a fatty acid to form an amide.

When the amide is formed in situ according to the process of the invention, the amount of fatty acid that was present in the reaction mixture is of course reduced as it reacts with the amine. It is preferred that the amine be added in such a quantity that there is less than 10 percent fatty acid, more preferably 5 percent or 1 percent fatty acid and most preferably, essentially no free fatty acid left in the final reaction mixture.

It should be understood that with regards to this invention the term "in situ" means only that the amide is formed in the presence of the reaction product (for example an alkanolamine ester) with the fatty acid (or fatty acid mixture) which was used to react

(esterify) the starting material having the reactive H for example an alkanolamine. This may be done in the same reaction vessel and under the same reaction conditions as the initial reaction, or it may be done in a separate reaction vessel or under different reaction conditions. The formation of amides from acids and amines is generally known and well- described in the public literature. For example amines and acid can be reacted at low temperatures, for example,-10°C to 25°C, to form ammonium salts, which can then be converted to amides (and water) at higher temperatures, for example up to 250°C. Of course, it is also known that the ammonium salt formation occurs also at higher temperatures and can be followed at once by the amide formation. The choice of the initial temperature depends on the volatility of the amine; once the ammonium salt formed, the heating can start. In case of high boiling amines the in situ formation of amides can be conveniently combined with the conditions of the esterification (or other reaction of a reactive H with a fatty acid for example amidation reaction) step. After the esterification reaction has come to a certain point, where a certain amount of unreacted acid is left, which can be estimated from the kinetics of that particular esterification reaction and which can be determined by chemical analysis (for example by titration), the selected amine can be directly introduced into the reaction mixture and the process can be continued as if it was an esterification. It may be necessary to first cool down the ester mixture somewhat (for example to 170°C for DEA, 140°C for MEA), and to increase the pressure, for example, to atmospheric (if the esterification reaction was carried out under diminished pressure) to prevent evaporation of the amine. After the addition of the amines is completed, the previous conditions can be established again. It is also understood that in the special case of 1 ,2-diamines such as AEEA, DETA, TETA, or TEPA, the formation of imidazoline rings can also take place during the amidation reaction depending on the temperature and pressure conditions used.

The composition of the present invention may include more than one esterquat, or more than one amide. It may also contain other ingredients used in fabric softeners, detergents, cleaners, or personal care formulations. These are well known in the art and include things such as enzymes and enzyme stabilizers, dispersing agents, optical brighteners, suds suppressers, non-esterquat fabric softeners, non-esterquat surfactants such as cationic, anionic, nonionic, amphoteric, zwitterionic surfactants , thickening agents, viscosity control agents, pH modifiers, colorants, perfumes, preservatives, bactericides, germicides, fungicides, and antistatic agents. For examples of these materials, see WO97/31889, WO98/35002, WO-A-95/19951 , WO-A-93/25648, WO-A-93/23510, WO-A-96/21715, WO-A-96/09436, WO-A-94/29521 , Unilever 1 , 104,441 (UK), Unilever GB 2 197 66 A, EP 0 413 249 A1 , WO 98/41604, WO 97/03169, WO 98/18890, WO 96/33800 and EP-A-0580245. The formulations preferably contain less than 5 percent (by weight as compared to the esterquat) salts of primary fatty amines, and most preferably do not contain any such materials.

As previously mentioned, the compositions of the present invention, especially those in which the amide is made in situ such that there little, if any, free fatty acid in the formulation, exhibit improved hydrolytic stability and can be concentrated in an aqueous solution to a much higher level than previously observed. These properties allow the formulations to be particularly well suited for use in fabric softeners, detergents, dryer sheets, personal care and cleaning applications. Aqueous fabric softeners made with a composition of the present invention can be concentrated such that the aqueous formulation comprises 20 percent, 25 percent, 30 percent 35 percent or even 40 percent by weight esterquat. Of course, even at lesser concentrations the formulations are improved as they are more hydrolytically stable and may demonstrate improved viscosity profiles.

The esterquat and the amide (or the reactants used to make them) can be chosen to make the formulation even more suitable for a particular application. For example, if the target application was as a fabric softener then it is possible to use an amide (or to use an amine which reacts with the fatty acid to form an amide) which is known to have fabric softening properties, in order to get an extra benefit. Additionally, diesterquats are generally considered to have better fabric softening properties than monoester or triesterquats, and so the reactants and reaction conditions should be chosen so as to optimize the production of diesters when the target application is fabric softening. Similarly, as is generally known in the art, higher degrees of saturation of the alkyl chain on the fatty acid (the T group in the esterquat), and longer chain lengths results in generally better softening properties. It is also known, however, that more unsaturation in the alkyl chain of the fatty acid leads to a greater ability to concentrate the esterquat mixture in an aqueous formulation. On the other hand, if the composition is to be used as a detergent, and especially a concentrated detergent then it is generally preferred that the alkyl group on the fatty acid be shorter. Alkyl chains of 16 or less, with Iodine values less than 20 are generally preferred in this application. As another example, it is also believed that some amides have anti static properties making formulations including these amides particularly appropriate for use in dryer sheets.

It should be understood that these teachings as to how to optimize an esterquat for use in a particular application, are merely exemplary, and that in general, any method to optimize previously known esterquats will apply equally to the formulations of the present invention.

The following examples are included for illustration purposes and should not be interpreted as limiting the scope of the invention or the claims. Unless otherwise indicated all percentages are by weight. The abbreviations, used in the examples, have already been described in the specification.

Example 1 (comparative)

In a stirring, heating and temperature controlled equipment, provided with a device for collection of reaction water, Radiacid™ 409 was mixed with DMAPD in a mole ratio of 2. The pressure was decreased to 200 mbar. Then the temperature was raised to 200°C within typically one hour, while the pressure was gradually decreased to 20 mbar. The reaction mixture was kept at 175°C/20 mbar during 7 hours, after which the reaction was stopped. The residual acid content was then 9.1 weight percent, determined by titration.

The esteramine, thus obtained, was solved in 20 weight percent acetone at 95°C in an appropriate pressure vessel. Then 1.5 moles of MeCI per mole of esteramine were added and the mixture kept at 95°C/5 to 4 barg during 2 hours. Next the reactor was discharged removing the excess of MeCI and the solvent, leaving a solid material. From titration analysis of residual amine it was found that the esteramine was quaternized for 100 percent (residual Nitrogen determination by perchloric acid titration).

Example 2 (comparative)

The procedure of Example 1 was repeated with a mole ratio acid: DMAPD of 2 and with a esterification reaction time of 12 hours, resulting in a residual acid content of 5.7 weight percent.

Example 3 (comparative)

The procedure of Example 1 was repeated with a mole ratio acid: DMAPD of 2.3 and with a esterification reaction time of 8 hours, resulting in a residual acid content of 15 weight percent.

Example 4

The esterification procedure of Example 1 was repeated with a mole ratio acid: DMAPD of 2. The reaction mixture was kept at 175°C/20 mbar during 8 hours, after which the residual acid content was 8.4 weight percent. Then the vacuum was interrupted and the temperature decreased to 170°C. DEA was added in an amount of 3 weight percent. The temperature was raised again to 200°C and the pressure decreased to 20 mbar. The mixture was kept for an hour under these conditions, after which the residual acid content was 0.8 weight percent. The final product contained about 10 weight percent amide.

The esteramine/amide mixture, thus obtained, was solved in 20 weight percent acetone at 95°C in an appropriate pressure vessel. Then 1.5 moles of MeCI per mole of esteramine were added and the mixture kept at 95°C/4-5 barg during 2 hours. Next the reactor was discharged removing the excess of MeCI and the solvent, leaving a solid material. From analysis of residual amine it was found that the esteramine was quaternized for 100 percent. Example 5

The esterquat products of Example 1 to 4, were dispersed in water in different concentrations and the viscosities measured. At the same time a 5 weight percent dispersion in water was kept at 50°C/pH 4, after 4 weeks the hydrolysis of the esterquat was measured. The results are in the next Table I.

From Table I, it is clear that the example of the invention (Example 4) provides superior hydrolytic stability and has a lower viscosity when formulated at any concentration in water and consequently it can be concentrated to a higher degree than the comparative examples. This is in addition to the benefit of reduced reaction time.

Example 6 (comparative)

In a stirring, heating and temperature controlled equipment, provided with a device for collection of reaction water, Radiacid™ 409 was mixed with MDEA in a mole ratio of 1.6. The pressure was decreased to 200 mbar. Then the temperature was raised to 200°C, while the pressure was gradually decreased to 20 mbar. The reaction mixture was kept at 200°C/20 mbar for 1 hour, after which the reaction was stopped. The residual acid content was then 7.9 weight percent.

The esteramine, thus obtained, was dissolved in 20 weight percent acetone at 95°C in an appropriate pressure vessel. Then 1.5 moles of MeCI per mole of esteramine were added and the mixture kept at 95°C/6 to 4 bar gauge during 8 hours. Next the reactor was discharged removing the excess MeCI and the solvent, leaving a solid material. From analysis of residual amine it was found that the esteramine was quaternized for 100 percent.

Example 7 (comparative) The procedure of Example 6 was repeated with a mole ratio acid:MDEA of 1.6 and with a esterification reaction time of 18.5 hours, resulting in a residual acid content of 1.0 weight percent.

Example 8

The esterification procedure of Example 6 was repeated with a mole ratio acid:MDEA of 1.6. The reaction mixture was kept at 200°C/20 mbar for 1 hour, after which the residual acid content was 7.7 weight percent. Then the vacuum was interrupted and the temperature decreased to 170°C. DEA was added in an amount of 2.8 weight percent. The temperature was raised again to 200°C and the pressure decreased to 20 mbar. The mixture was kept for an hour under these conditions, after which the residual acid content was 0.2 weight percent. The final product contained about 10 weight percent amide.

The esteramine/amide mixture, thus obtained, was dissolved in 20 weight percent acetone at 95°C in an appropriate pressure vessel. Then 1.5 moles of MeCI per mole of esteramine were added and the mixture kept at 95°C/6 to 4 bar gauge for 8 hours. Next the reactor was discharged removing the excess MeCI and the solvent, leaving a solid material. From analysis of residual amine it was found that the esteramine was 100 percent quaternized.

Example 9 (comparative)

The procedure of Example 6 was repeated with a mole ratio acid: MDEA of 2 and with a esterification reaction time of 2 hours, resulting in a residual acid content of 8.8 weight percent. Example 10

The procedure of Example 8 was repeated with a mole ratio acid: MDEA of 2, with a esterification reaction time of 2 hours, resulting in a residual acid content of 8.8 weight percent, with 3.2 weight percent DEA addition, resulting in a final residual acid content of 0.4 weight percent and an amide content of about 11 weight percent. Example 11

The esterquats products of Examples 6 to 10 were dispersed in water in different concentrations and the viscosities measured. At the same time, a 5 weight percent dispersion in water was kept at 50°C/pH 4, after 4 weeks the hydrolysis of the esterquat was measured. The results are in the Table II.

From the table, it is clear that the examples of the invention (Examples 8 and 10) provides superior hydrolytic stability that the relative comparatives (Examples 6, 7 and 9 respectively). The viscosity data obtained on these systems did not demonstrate any clear trends. Example 12 (comparative)

In a stirring, heating and temperature controlled equipment, provided with a device for collection of reaction water, Radiacid™ 406 was mixed with TEA in a mole ratio of 1.6. The pressure was decreased to 200 mbar. Then the temperature was raised to 200°C, while the pressure was gradually decreased to 20 mbar. The reaction mixture was kept at 200°C/20 mbar during 2.5 hours, after which the reaction was stopped. The residual acid content was then 2.9 weight percent.

The esteramine, thus obtained, was heated to 70°C. Then, carefully, 0.9 moles of DMS per mole of esteramine was added and the mixture kept at 90°C for 2 hours. From analysis of residual amine it was found that the DMS was fully converted and the esteramine quaternized for 90 percent.

Example 13 (comparison)

The procedure of Example 12 was repeated with a mole ratio acid: TEA of 1.7 and with a esterification reaction time of 1 hour, resulting in a residual acid content of 6.2 weight percent. Example 14

The esterification procedure of Example 12 was repeated with a mole ratio acid.TEA of 1.7. The reaction mixture was kept at 200°C/20 mbar during 1 hour, after which the residual acid content was 8.2 weight percent. Then the vacuum was interrupted and the temperature decreased to 170°C. DEA was added in an amount of 3 weight percent. The temperature was raised again to 200°C and the pressure decreased to 20 mbar. The mixture was kept for an hour under these conditions, after which the residual acid content was 0.3 weight percent. The final product contained about 10 weight percent amide.

The esteramine/amide mixture, thus obtained, was heated to 70°C. Then carefully 0.9 moles of DMS per mole of esteramine was added and the mixture kept at 90°C for 2 hours. From analysis of residual amine it was found that the DMS was fully converted and the esteramine quaternized for 90 percent. Example 15

The products of Examples 12 to 14 were dispersed in water at 20 percent concentration and the viscosities measured. At the same time, a 5 weight percent dispersion in water was kept at 50°C/pH 4, after 4 weeks the hydrolysis of the esterquat was measured. The results are in the Table III.

provides superior hydrolytic stability and has a lower viscosity when formulated at 20 percent concentration in water and consequently it can be concentrated to a higher degree than the comparative examples.

Example 16

The procedure of Example 10 was repeated where 3.2 percent DEA was replaced by DIPA, resulting in a final residual acid content of 1.5 percent and an amide content of about 10 percent. At the same time a 5 weight percent dispersion in water was kept at 50°C/pH 4, after 4 weeks the hydrolysis of the esterquat was measured to be 56 percent, which is far better than the one of the comparative Example 9.

It should be noted that in the Examples 4, 8, 10 and 14 DEA can be replaced by equivalent amounts of other amines such as MEA, MIPA, DIPA, AEEA, EDA, DETA, TETA, or TEPA. Similarly, the DMAPD, MDEA or TEA, can be replaced with other tertiary di- and trialkanolamines can be used, such as DEA-1 PO, DEA-1 BO, MEA-2PO, TIPA, MDIPA, MAE-1 PO, MAE-1 BO and alkoxylated tertiary di- and trialkanolamines. Furthermore, tertiary mo/7oalkanolamines, like DMAE and DMAP and their alkoxylates, can also be used. It should be noted that these monoalkanoiamines may have applications in detergents, especially if esterified with fatty acids having shorter chain lengths such as Radiacid™ 600 or Radiacid™ 626. Example 17 (amide formation)

In appropriate equipment, provided with a device for collection of reaction water, Radiacid™ 406 was mixed with DEA in a mole ratio of 1. The pressure was decreased to 200 mbar. Then the temperature was raised to 200°C, while the pressure was gradually decreased to 20 mbar. The reaction mixture was kept at 200°C/20 mbar for 1 hour, after which the reaction was stopped. The residual acid content of the DEA amide was then 0.6 weight percent.

Example 18

The TEA esterquat of Example 13 was molten together with the DEA amide of Example 17 (10:1 weight ratio). This mixture was dispersed in water (20 weight percent).

Example 19

The TEA esteramine of Example 13 was molten together with the DEA amide of Example 17 and this mixture quaternized with DMS as described in Example 12. The resulting esterquat was dispersed in water (20 weight percent). Example 20

In a stirring, heating and temperature controlled equipment, provided with a device for collection of reaction water, Radiacid™ 406 was mixed with TEA in a mole ratio of 1.7. The pressure was decreased to 200 mbar. Then the temperature was raised to 200°C, while the pressure was gradually decreased to 20 mbar. The reaction mixture was kept at 200°C/20 mbar for a time long enough to esterify more than 99 weight percent of the fatty acid, after which the reaction was stopped. The residual acid content was then 0.5 weight percent.

The esteramine, thus obtained, was heated to 70°C. Then carefully 0.9 moles of DMS per mole of esteramine was added and the mixture kept at 90°C for 2 hours. From analysis of residual amine it was found that the DMS was fully converted and the esteramine 90 percent quaternized. This mixture was dispersed in water (20 weight percent).

Example 21

Product of Example 17 was molten and was added to the molten product of Example 20 such that the ratio of product of Example 17 to the product of Example 20 is 6:100. The obtained mixture was dispersed in water (20 weight percent). Example 22

The aqueous dispersions of Examples 18, 19, 20 and 21 , the viscosity were measured. The results are in Table IV.

By comparing the results in the table above with the results in the Example 15 for the products of Example 13 and 14, one can conclude than the benefits of having the presence of DEA based amide in TEA esterquat are best seen when the DEA amide is formed in situ (Example 14) as this leads to a lower viscosity of the formulation under consideration.

Example 23

In appropriate equipment, provided with a device for collection of reaction water, Radiacid™ 406 was mixed with DETA in a mole ratio of 2 to 1. The pressure was decreased to 200 mbar. Then the temperature was raised to 175°C, while the pressure was gradually decreased to 20 mbar. The reaction mixture was kept at 175°C/20 mbar for 4 hours. The residual acid content of the DETA amide was then 7.5 weight percent.

Example 24

DEA was added in an amount of about 3 weight percent to the product of Example 23 at a temperature of 60°C to 70°C. The temperature was raised again to 175°C and the pressure decreased to 20 mbar. The mixture was kept for two hours under these conditions, after which the residual acid content was 0.9 weight percent. The final product contained about 10 weight percent of DEA-amide.

Example 25 In appropriate equipment the product of Example 23 was ethoxylated with EO in a mole ration of 1 to 3 in presence of KOH catalyst in about 2.5 hours at a temperature of 120°C and at a pressure of 3 to 5 atmosphere. The product was then neutralized with low amounts of acetic acid.

Example 26

In appropriate equipment the product of Example 23 can be alkoxylated during about two hours with BO without the presence of a catalyst in a mole ratio of 1 to 1 and then ethoxylated with EO in a mole ratio of 1 to 2.5 in presence of KOH catalyst in about 2.5 hours. The product can then be neutralized with low amounts of acetic acid. This product could then be mixed with product of Example 20 in a ratio described in Example 29 and then be formulated in an aqueous medium as described in Example 29 to lead to a 30 weight percent active formulation having a viscosity at 25°C of less than 100 mPa-s

Example 27

The procedure of Example 10 was repeated with a mole ratio acid: MDEA+1 PO of 2 and with an esterification time of 8.5 hours, resulting in a residual acid content of 8.6 weight percent. DEA was added in an amount of about 3 weight percent and then the temperature was raised again to 200°C and the pressure decreased to 20 mbar. The mixture was kept for an hour under these conditions, after which the residual acid content was 0.4 weight percent. The final product contained about 10 weight percent amide.

Example 28

The exact procedure of Example 4 was repeated but with one exception. The Radiacid™ 409 was replaced by Radiacid™ 406. The final product contains 0.8 weight percent of residual acid and about 10 weight percent amide.

Example 29

Products of Example 23 to 25 have been molten and mixed with molten products of Examples 13, 14, 20, 27 and 28 in a ratio of 2:1 and then formulated in warm water (containing sufficient amount of hydrochloric acid to fully neutralize the various DETA amides) at either 20 percent concentration or 30 percent concentration. 0.5 weight percent CaCI₂ was systematically added at the end of the formulation in order to decrease the viscosity of the final mixture which was measured at 25 C (mPa-s). Results are reported in the table below.

Products containing high free fatty acids amounts are difficult to concentrate (experiment 1). Although the presence of DEA -amide is beneficial (experiment 2 compared to experiment 1 ), one will note that too much DEA-amide will lead to a higher viscosity (experiment 2 and 7). Lowest viscosities are obtained when either the DEA-amide weight percent is below 10 percent and/or when the products used contain oxides such as EO, PO or BO (experiments 3 to 6). It is also important to note that the product of Examples 23 to 25 are amido-amines which are themselves good softeners and thus the total active softening concentration in experiment 2 to 7 is 30 percent and yet the viscosities are within acceptable limits for such very concentrated aqueous softener formulations.

Those of ordinary skill in the art should realize that the invention is not limited to the exact configuration or methods illustrated above, but that various changes or modifications may be made without departing from the spirit and scope of the invention as claimed in the following claims.

Claims

1. A composition of matter comprising: an esterquat and an amide and having salts of primary fatty amines present in an amount no greater than 5 percent of the esterquat by weight, where the esterquat corresponds to the following formula: [NR'R'FfA]^* X wherein X is a softener compatible anion;

A is independently at each occurrence [CH₂]_n-[CYR³]_m-CYR³H;

Y is independently at each occurrence H, OH, N(R⁴)2 or QT;

Q is independently at each occurrence -O-C(O)-; -C(O)-O-; O-C(O)-O-; NR⁴C(O)-; -C(O)NR⁴-; or (O-CH₂-CHR³)_p-O-C(O)-; (O-CH₂-CHR³)_p-C(O)-O-

T is independently at each occurrence a C_-C₃_ alkyl group;

R¹ is independently at each occurrence a C,-C₄ alkyl group, or an aryl group having 6-12 carbons, optionally substituted with an alkyl group, or an hydroxyalkyl group having 2 to 6 carbons; R² is independently at each occurrence R¹ or A;

R³ is independently at each occurrence H or R¹;

R⁴ is independently at each occurrence H or R' or a C.-C₄ hydroxyalkyl group; n is independently at each occurrence a number equal to 1 or greater; m is independently at each occurrence a number from 0 to 5; p is independently at each occurrence a number from 1 to 10; with the proviso that at least one Y is QT and at least one Q contains an ester group, and wherein the amide corresponds to the following formula:

(J)(J)N[-P-N(Z)]_m,-(J) where: J is independently at each occurrence

-(CH₂-CHR⁵-O)_a-R⁶ or -C_n,H₍₂,_+1.x)(OR⁸)_x

Z is independently at each occurrence J or _-P-N(J)(J)] P is independently at each occurrence -C_{2 12} hydrocarbyl or -C_n,H_(2n,_x)(R⁹)_x-

R⁵ is independently at each occurrence H or a C_{1 4} alkyl

R⁶ is independently at each occurrence H, C,.₂₀ alkyl or (-C(O)R⁷)

R⁷ is independently at each occurrence a C₅₃₅ alkyl R⁸ is independently at each occurrence R⁶ or (-CH₂-CHR⁵-O)_a-R⁶

R⁹ is independently at each occurrence -OR⁸ or -N(R⁸)(R⁸) a is independently at each occurrence 0-30 x is independently at each occurrence 0-6 m' is independently at each occurrence 0-10 n' is independently at each occurrence 2-6 with the proviso that there is at least one (-C(O)R⁷) present and connected directly to a nitrogen atom.

2. The composition of Claim 1 wherein there are no salts of primary fatty amines present.

3. The composition of Claim 1 wherein the ratio of amide to esterquat is less than 1:9.

4. The composition of Claim 1 further comprising a second esterquat which corresponds to the same formula.

5. The composition of Claim 1 further comprising a second fabric softener active ingredient which does not correspond to the esterquat formula.

6. The composition of Claim 1 wherein at least one Q is -OC(O)- or -(OCH₂CHR³)_pOC(O)-.

7. The composition of Claim 1 wherein T is C₇ to C₁₃.

8. The composition of Claim 1 wherein the T group is fully saturated.

9. The composition of Claim 1 wherein the T group is partially unsaturated.

10. The composition of Claim 1 wherein the esterquat comprises a diesterquat formed by the reaction of a fatty acid having 6 to 24 carbon atoms with a compound selected from the following group: triethanolamine; methyidiethanol amine, and DMAPD.

11. The composition of Cla m 1 wherein at least one m is not zero.

12. The composition of Cla m 1 wherein at least one Q group present in the esterquat contains a (O-CH₂-CHR³)_p group

13. The composition of Cla m 1 wherein R³ is H, CH₃ or C₂H₅.

14. The composition of Cla m 1 wherein p is 1-3

15. The composition of Cla m 1 wherein R⁵ is H, CH₃ or C₂H₅.

16. The composition of Cla m 1 or 10 wherein a is 0 or 1.

17. The composition of Cla m 1 or 10 wherein at least one R⁵ is present and is C₂H₅.

18. The composition of Cla m 16 wherein R⁶ is C(O)C_5.19.

19. The composition of Cla m 1 wherein x is 0,1 or 2.

20. The composition of Cla m 1 wherein R⁷ is

21. The composition of Cla m 1 wherein P is a

C_2.6 hydrocarbyl group.

22. The composition of Clai m 1 wherein a is 0 to 10.

23. The composition of Clai m 1 wherein m' is 0 to 5.

24. The composition of Cla m 1 wherein the amide is not a monoalkanolamide.

25. The composition of Claim 1 wherein the amide is based one the following amines; MAE, MIPA, MEA, TEPA, TETA, AEEA, DEA, DIPA, EDA, DETA, ammonia, and primary and secondary alkylamines having 1 to 20 carbons which are then partially or fully amidated with fatty acids having 6 to 24 carbon atoms and optionally alkoxylated with up to 30 moles of EO, PO or BO.

26. In an initial reaction comprising contacting one species having a reactive H with a fatty acid of the formula R⁷C(0)OH at any pressure or temperature to convert at least a portion of the reactive H to the R⁷C(O)- radical, the improvement comprising: allowing the initial reaction to continue for a period of time and then adding an amine to react with at least a portion of the fatty acid which has not yet reacted with the species having the reactive H, wherein the amine reacts with the fatty acid at a faster rate than the species having the reactive H, and wherein the amine corresponds to the formula: (J)(J)N[-P-N(Z)L-(J) where: J is independently at each occurrence -(CH₂-CHR⁵-0)_a-R⁶ or -C_n,H_(2n,₊,_x)(OR⁸)_x

Z is independently at each occurrence J or [-P-N(J)(J)]; P is independently at each occurrence -C_2.,₂ hydrocarbyl or -C_n,H_(2n,_.x)(R⁹)_x-;

R⁵ is independently at each occurrence H or a C_{1 4} alkyl;

R⁶ is independently at each occurrence H, C,_.zo alkyl or (-C(O)R⁷);

R⁷ is independently at each occurrence a C₅.₃₅ alkyl;

R⁸ is independently at each occurrence R⁶ or (-CH₂-CHR⁵-0)_a-R^6;

R⁹ is independently at each occurrence -OR⁸ or -N(R⁸)(R⁸); a is independently at each occurrence 0 to 30; x is independently at each occurrence 0 to 6; m' is independently at each occurrence 0 to 10; n' is independently at each occurrence 2 to 6; with the proviso that there is at least one H connected directly to a nitrogen atom which is capable of reacting with a fatty acid to form an amide.

27. The improved reaction of Claim 26 wherein the species having the reactive H is an alkanol amine, and the initial reaction forms an esterified alkanolamine.

28. The improved reaction of Claim 26 wherein the species having the reactive H is an amine and the initial reaction forms an amide.

29. The improved reaction of Claim 28 wherein the amide still contains at least one primary or secondary amine group which is further alkoxylated with C₂-C₆ oxides.

30. The improved reaction of Claim 26 or 29 wherein a species formed in the initial reaction contains N and wherein that nitrogen-containing species is further reacted to form a quaternized or neutralized species.

31. The use of a composition according to Claim 1 in a fabric softener, softergent, detergent, dryer sheet, personal care or cleaner application.

32. The use of a product made according to the process of any one of Claims 26 through 30 in a fabric softener, softergent, detergent, dryer sheet, personal care or cleaner application.

33. The use as in Claim 31 or 32 wherein the fabric softener, softergent, detergent, , personal care or cleaner is an aqueous formulation.

34. The use as in Claim 31 or 32 wherein the fabric softener, softergent, detergent, dryer sheet, personal care or cleaner is not an aqueous formulation.

35. The use as in Claim 33 wherein the formulation contains more than 20 percent by weight of the esterquat.

36. The use as in Claim 33 wherein the formulation contains more than 30 percent by weight of the esterquat.

37. The use as in Claim 33 wherein the formulation contains more than 40 percent by weight of the esterquat.

38. A process of improving the concentratibility of an esterquat based fabric softener composition, comprising adding an amount of an amide to the composition, wherein the amide corresponds to the formula:

(J)(J)N[-P-N(Z)]_m,-(J) where: J is independently at each occurrence

-(CH₂-CHR⁵-0)_a-R⁶ or -C_n,H_(2n,_+1.x)(OR⁸)_x;

Z is independently at each occurrence J or [-P-N(J)(J)] ;

P is independently at each occurrence -C_2.12 hydrocarbyl or -C_n,H_(2n,_x)(R⁹)_x-; R⁵ is independently at each occurrence H or a C_{1 4} alkyl;

R⁶ is independently at each occurrence H, C_{1 20} alkyl or (-C(O)R⁷);

R⁷ is independently at each occurrence a C_5.35 alkyl;

R⁸ is independently at each occurrence R⁶ or (-CH₂-CHR⁵-0)_a-R⁶;

R⁹ is independently at each occurrence -OR⁸ or

-N(R⁸)(R⁸); a is independently at each occurrence 0 to 30; x is independently at each occurrence 0 to 6; m' is independently at each occurrence 0 to 10; n' is independently at each occurrence 2 to 6; with the proviso that there is at least one (-C(O)R⁷) present and connected directly to a nitrogen atom.