GB1574496A - Quaternary imidazolinium salts and their use as fabric conditioning agents - Google Patents

Abstract

The fabric conditioner contains as the active component a quaternary imidazolinium salt of the formula <IMAGE> where D, R, R2, R3, R4 and X<-> are each as defined in Claim 1. The conditioner contains in total less than 4% of primary amines, secondary amines and cyclic tertiary amine salts, based on the weight of the imidazolinium salt. A process for conditioning fabrics in the wash comprises the addition to the rinse bath of the fabric conditioner in an amount corresponding to 2 to 500 parts per million of the imidazolinium salt.

Description

(54) QUATERNARY IMIDAZOLINIUM SALTS, AND THEIR USE AS FABRIC CONDITIONING AGENTS (71) We, THE PROCTER & GAMBLE COMPANY, a corporation organised under the laws of the State of Ohio, United States of America, of 301 East Sixth Street, Cincinnati, Ohio 45202, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to quaternary imidazolinium salts and their use as fabric conditioning agents. The present invention additionally relates to a fabric conditioning composition containing such a quaternary imidazolinium agent and to a method for conditioning fabrics.

In the conventional home laundering process, soiled fabrics are subjected to cleaning with a detergent composition in the main wash cycle and rinsing with water in the final cycle. Optionally, during the rinsing cycle a fabric conditioning composition is added. Such compositions contain a fabric softener or fabric antistat material for imparting to the rinsed fabrics softening and antistat properties. The rinsed fabrics are oftentimes, thereafter, dried in an automatic clothes dryer.

Many different types of fabric conditioning agents have been used in rinse cycle added fabric conditioning compositions. The most favored type of agent has been the quaternary ammonium compounds. These compounds may take the form of noncyclic quatemary ammonium salts preferably having two long chain alkyl groups attached to the nitrogen atom. Additionally, imidazolinium salts have been used by themselves or in combination with other agents in the treatment of fabrics. U.S. Patent 2,874,074 discloses using imidazolinium salts to condition fabrics. U.S. Patents 3,681,241 and 3,033,704, disclose fabric conditioning compositions containing mixtures of imidazolinium salts and other fabric conditioning agents.

While the prior art shows the use of quaternary imidazolinium salts as fabric conditioning agents, it is silent about the problems encountered in making stable fabric conditioning compositions containing such agents and aldehydes. The manufacture of imidazolinum salts generally involves the reaction of a polyamine with an acyl containing material such as an acid or ester to form an imidazoline and then a quaternizing of the imidazoline. U.S. Patents 2,355,837, 2,267,965 and 2,520,102, all disclose methods for making imidazolines used in making imidazolinium salts. It has been found in the present invention that in addition to the imidazoline compound formed in the described reacton, primary and secondary amines are also present. During the subsequent quaternization step, these amines cause some of the imidazoline compound to form the imidazoline amine salt rather than the quaternary imidazolinium salt. The imidazoline amine salt, when present in an aqueous medium having a near neutral or higher pH, is capable of undergoing ring opening to form free amines which will then react with aldehydic compounds in the composition much the same as free amines which have not been converted to the salt form. The result is that the odor of the composition degrades (perfumes generally contain aldehydes), the color and the pH change and aldehyde preservatives degrade. The aforementioned U.S. Patent 2,874,074 describes making quaternary imidazolinium salts, but is silent about how to overcome the problems described while still achieving an end product which is sufficiently high in imidazolinium salt to be commercially attractive. In the process aspect of the present invention the undesirable amines are " capped" using an alkoxylating agent in an amount sufficient to cap the primary and secondary amines but not cap to any appreciable degree the cyclic tertiary amine which forms the imidazolinum salt.

As used herein all percentages and ratios are by weight unless otherwise specified.

The present invention provides a quaternary imidazolinium salt of the following structure:

wherein R and R1 are aliphatic or cycloaliphatic hydrocarbon groups containing from 10 to 22 carbon atoms; D is a direct bond or a divalent organic radical, other than amino, containing from 1 to 20 carbon atoms and composed of elements selected from C, O, N and H and when D is a direct bond R1 can also denote "a group from the imidazoline forming amine" (as hereinafter defined); X is an anion; R2 is an alkyl, substituted alkyl or aralkyl group containing from 1 to 8 carbon atoms; and R, and R4 are hydrogen, hydroxy, alkyl having from 1 to 4 carbon atoms or hydroxy-alkyl having from 1 to 4 carbon atoms, which contains a total of less than 4% by weight of primary gamines, secondary amines, and/or cyclic tertiary amine salts based on the weight of imidazolinium salt, as impurities. It is to be appreciated that while the R2 group is shown as being on the number 3 nitrogen, it may in fact be attached to the number 1 nitrogen.

The invention also encompasses the use of such a quaternary imidazolinium salt as a fabric conditioning agent as well as methods of conditioning fabrics with the imidazolinium salts.

According to the present invention we further provide a process for the production of a quaternary imidazolinium salt as defined above comprising the steps of: (a) reacting an acylating or esterifying agent having an aliphatic or cycloaliphatic hydrocarbon group containing from 10 to 22 carbon atoms associated with each acyl group with an alkylene or polyalkylene polyamine having two or three amino groups, one of which is a primary or secondary amino group in the 2 position to a primary amino group, the molar ratio of acyl groups to primary amine and hydroxyl groups being from 0.33 to 1.5:1 for a period of from 3 to 24 hours at a temperature of from 1000C to 2500C; (b) subjecting the reaction mixture to a vacuum of from 0.4 mm mercury to 10 mm mercury for from 1 to 8 hours to form an imidazoline product; (c) treating the imidazoline product mixture of step (b) with an alkoxylating agent in an amount equal to from 1% to 5% by weight of the imidazoline product mixture while maintaining the temperature at from 800C to 1400C for a period of from 0.5 to 8 hours; and (d) treating the mixture of step (c) with an alkylating agent in an amount such that the molar ratio of alkylating agent to imidazoline is at least 1:1.

The reaction to form the desired imidazolinium salt involves the following steps: Formation of Imidazoline The imidazoline precursor for the desired imidazolinium salt is formed by (a) reacting an acylating or esterifying agent with an alkylene or polyalkylene polyamine having two or three amino groups, one of which is a primary or secondary amino group in the 2 position to a primary amino group. The reaction is conducted at a temperature of from 1000C to 2500C for a period of from 3 to 24 hours, at a molar ratio of acyl groups to primary amine and hydroxyl groups ranging from 0.33:1 to 1.5:1, preferably from 1:1 to 1.5:1, and under reflux or at atmospheric pressure or slightly greater; and (b) subjecting the reaction mixture to a vacuum of from 0.4 to 10 mm of mercury for a period of from 1 to 8 hours. The resulting mixture contains in addition to the desired imidazoline some of the original acylating material, some of the original polyamine, some of the noncyclized intermediate amide products and other mixed reaction products. The acylating or esterifying agent may be any acid or other acyl containing compound having an aliphatic or cycloaliphatic hydrocarbon group of 1022 carbon atoms.

Examples of such materials include the fatty acids lauric, decanoic, undecanoic, dodecanoic, tridecanoic, myristic, pentadecanoic, hexadecanoic and palmitic. Preferred fatty acids are the mixtures thereof derived from tallow, soybean or coconut oils. ParticularBy preferred are the soft or hardened tallow fatty acids. Other acylating or esterifying agents include the alkyl esters of the fatty acids and the naturally occurring glyceride esters. The latter are preferred for use herein.

The polyamine material, as indicated above, has either two or three amino groups, one of which is a primary or secondary amino group in the 2 position to a primary amine group. These preferably take the following form: NH2-CH2-CH2-NH-X where X may be, for example, hydrogen, +CH-CH2 )nNHs, CH2CH2+nOH or CH,-CH2±CH, wherein n is from 1 to 6. Examples of such polyamines include diethylenetriamine, ethylenediamine and hydroxyethyl ethylenediamine.

The term " group from the imidazoline forming amine" means a group, such as X immediately above, which is a group constituted by that part of the original imidazoline forming amine which does not form part of the imidazoline ring.

Addition of Second Long Chain Alkyl or Substituted Alkyl Group As described above, the formation of the imidazoline is accomplished by reacting a polyamine with an acylating or esterifying agent. If the amount of acylating or esterifying agent used is not sufficient to form an amide or ester with at least two of the amine or hydroxyl groups present in the polyamine (the molar ratio of acyl groups to primary amine or hydroxyl groups being from 0.33 to 0.66), the imidazoline formed will only have a long chain group of the type desired positioned at the 2 position rather than at both the 1 and 2 positions of the imidazoline ring. The mono substituted.

material then has to be reacted further with an acylating or esterifying agent. The reaction temperature is generally the same as the generalized reaction given above while the molar ratio of acylating agent or esterifying agent to mono substituted imidazoline ranges from 1:1 to 1.5:1 and the reaction time ranges from 1 to 24 hours. Optionally, a vacuum of from 0.4 to 10 mm of mercury is drawn. This reaction can be exemplified as follows using diethylenetriamine as the polyalkylene polyamine:

0 R -c OH + NH2 -CH2-CH2 --NH -CH2-CH2 -NH2 - > H20 rernovesi R-C - NH-CH2-CH2 - NH-CH2-CHZ-NH2 + N CH2 R -C\ &verbar; + H20 (removed &verbar; N CH2 (removed) I CHZ CHz - NHZ where R is an aliphatic or cycloaliphatic hydrocarbon group containing from 10 to 22 carbon atoms.

The primary amine present in the imidazoline formed above then has to be converted to an amide to attach the second long chain R group in the following manner:

where R1 is an aliphatic or cycloaliphatic hydrocarbon group containing from 10 to 22 carbon atoms. The group

in the above formula corresponds to D in the formula given above. It should be appreciated that D may be another divalent radical or absent depending on the choice and concentration of polyamine and acylating or esterifying agent. See, for example, U.S.

Patent 2,267,965 mentioned previously, where an hydroxy group is attached to the 1 position of the imidazoline ring. U.S. Patent 2,355,837 describes a number of suitable polyamines.

Of course, if the amount of acylating or esterifying agent used contains a number of acylating groups sufficient to form an amide or ester with at least two of the amine or hydroxyl groups (ratio of acylto primary amine or hydroxyl groups is from 0.67 to 1.5:1, preferably 1:1 to 1.1:1), the long chain group in the 1 position would be present as a result of the initial imidazoline forming reaction. The following represents such a reaction:

Some of the intermediate amides shown above, as well as some of the starting materials, other intermediates, water and other complexes are present as diluents along with the desired substituted imidazoline. Some of the diluents are removed during the vacuum stage of the reaction.

Alkoxylation of Imidazoline The formation of the 1,2 substituted imidazoline product will have as components in addition to the desired imidazoline product the materials noted as diluents in the glyceride reaction above. If the imidazoline reaction formation is the fatty acid reaction given above wherein the 2 substituted imidazoline is formed first and then the second long chain aliphatic or cycloaliphatic hydrocarbon group is added in the 1 position by means of a reaction with a fatty acid, or other agent, the desired imidazoline is going to be present in a mixture containing some of the imidazoline substituted only at the 2 position and fatty acid or other agent. Similarly, regardless of which reaction route is used, there will be primary and/or secondary amines present in the final mixture due to either unreacted initial amine or the amide intermediate products. The materials which have primary and secondary amine groups present are undesirable since in the quaternizing step, to be discussed subsequently, the amines cause the disubstituted imidazoline to be transformed to an amine salt rather than a quaternary salt which, in turn, is capable of reverting to free amines when present in an aqueous composition having a pH of 5 or greater. U.S. Patent 2,874,074 discloses making the 1,2 substituted imidazoline by the two step fatty acid process, and utilizes the 2 substituted imidazoline as made in U.S. Patent 2,355,837 or U.S. Patent 2,267,965. The imidazoline product would contain a mixture of the 1,2 substituted material, the 2 substituted material, other amine containing materials and fatty acid. The 2 substituted material and the other amines are undesirable, as indicated above, due to their ability to cause the imidazoline salt to be formed.

We have found that the undesirable amine products present in the 1,2 substituted imidazoline reaction mixture can be effectively capped by treating the mixture with an alkylene oxide, preferably propylene oxide. The alkylene oxide serves to " cap" the amines by attaching an alkylene oxide moiety to the free amine. It is important that all of the primary and secondary amines are capped, but only a minimum of the tertiary amine in the imidazoline. To achieve these goals the mixture containing the desired 1,2 substituted imidazoline is treated with an amount of an alkylene oxide amounting to from 1 to 5% by weight of the mixture to be treated, while the temperature is kept at from 800C to 140"C and a vacuum is optionally drawn amounting to from 2 to 15 mm mercury. The vacuum helps to rid the system of excess alkylene oxide, polyamine and other low boiling diluents. The imidazoline containing mixture can also be diluted with an organic solvent such as isopropyl alcohol or glymes to facilitate the alkylene oxide treatment. Such solvents are generally used in an amount of from 1 to 25% by weight of the imidazoline mixture. The time of the reaction ranges from 0.5 to 8 hours. U.S.

Patent 2,713,582 discloses making fully alkoxylated imidazolines as a precursor for carboxylate detergent products. Examples of alkoxylating agents other than propylene oxide include butylene oxide, glycide, ethylene oxide and cyclohexame oxide.

Quaternization The alkylene oxide treated mixture from above is treated with an alkylating agent to form the desired quaternary imidazolinium material essentially free of amines, amine salts and alkoxylated forms of the imidazolinium salts. The imidazolinium product contains a total less than 4%, preferably less than 2%, of primary amines, secondary amines and cyclic tertiary amine salts and less than 25%, preferably 4%, of the alkoxylated form of the imidazolinium salt: The limit on the alkoxylated form is the result of wanting to make the nonalkoxylated imidazolinium salt as pure as possible and is not related to the amine/amine salt stability problem. The alkylating agent can be any of the known agents such as methylchloride, ethylbromide, diethylsulfate, dimethylsulfate, hexadecylchloride, among many others. The reaction can be exemplified in the following manner:

wherein D, R, R1, R3 and R4 are as described previously.

The amount of alkylating agent used should be equivalent to the amount of the imidazoline treated on a molar basis. However, an excess of the alkylating agent is generally used to assure maximum quaternization. The amount of excess employed should be sufficient so that the pH of the reaction medium is in the range of from 5 to 7. The reaction time generally ranges from 1 to 12 hours and the temperature from 40 to 800 C. If desired, a base may be added during the alkylation to aid quaternization.

The imidazolinium salt as formed above has outstanding fabric conditioning properties, softening and antistatic, while additionally allowing fabric conditioning compositons to be made which have improved aldehyde stability. A preferred imidazolinium salt contains R1 and R groups having 14-20 carbon atoms such as the following wherein the R groups are tallow cuts:

wherein CTa, < . is an aliphatic hydrocarbon chain derived from tallow fatty acid.

Other quaternary imidazolinium salts having desirable properties can be formed by substituting a different R group for tallow in the acrylating or esterifying agent, a different alkylene or polyalkylene polyamine for diethylenetriamine, and a different alkyl, substituted alkyl or aralkyl for the methyl group present, as well as a different anion, in the alkylating agent.

ExamDles of D are

where n is a number from 1 to 6. Examples of R2 are methyl, ethyl and benzyl. X is an anion associated with the alkylating agent and may be, for example, chloride, bromide, methylsulfate and ethylsulfate. It is to be recognized that while the quaternization is indicated as having taken place at 3-nitrogen, quaternization at the 1-nitrogen atom is not excluded. A preferred quaternary imidazolinium salt is the methylsulfate salt.

The salts of the present invention are preferably in the form of an aqueous solution in which the concentration of the quaternary imidazolinium salt, is preferably from 1 to 15% by weight; more preferably from 2 to 8% by weight.

The present invention also relates to fabric conditioning compositions which in addition to the quaternary imidazolinium salt of formula (I), also contain other fabric conditioning (softening/antistatic) agents in an amount of from 1 to 12% by weight.

Such other agents are preferably fatty cationic or nonionic organic materials and the agents are free of primary amines, secondary amines and cyclic tertiary amine salts and are generally employed as fabric conditioning agents during the rinsing cycle of the household laundering process. They are generally organic, waxy materials having a melting (or softening) point between 250C and 115 C. Such materials possess both fabric softening and fabric antistat properties.

Generally the cationic nitrogen-containing compounds such as quaternary ammonium compounds have one or two straight-chain organic groups of at least eight carbon atoms. Preferably, they have one or two such groups of from 12 to 22 carbon atoms.

Preferred cation-active softener compounds include the quaternary ammonium antistat/ softener compounds corresponding to the formula:

wherein R1 is hydrogen or an aliphatic group of from 1 to 22 carbon atoms; R2 is an aliphatic group having from 12 to 22 carbon atoms; R, and R4 are each alkyl groups of from 1 to 3 carbon atoms; and X is an anion selected from halogen, acetate, phosphate, nitrate and methyl sulfate radicals.

Because of their excellent softening efficacy and ready availability, preferred cationic antistat/softener compounds of the invention are the dialkyl dimethyl ammonium chlorides, wherein the alkyl groups have from 12 to 22 carbon atoms and are derived from long-chain fatty acids, such as hydrogenated tallow. As employed herein, alkyl is intended as including unsaturated compounds such as are present in alkyl groups derived from naturally occurring fatty oils. The term "tallow" refers to fatty alkyl groups derived from tallow fatty acids. Such fatty acids give rise to quaternary softener compounds wherein R1 and R2 have predominantly from 16 to 18 carbon atoms. The term " coconut" refers to fatty acid groups from coconut oil fatty acids.

The coconut-alkyl R1 and R2 groups have from 8 to 18 carbon atoms and predominate in C12 to C14 alkyl groups. Representative examples of quaternary softeners of the invention include tallow trimethyl ammonium chloride; ditallow dimethyl ammonium chloride; ditallow dimethyl ammonium methyl sulfate; dihexadecyl dimethyl ammonium chloride; di(hydrogenated tallow) dimethyl ammonium chloride; dioctadecyl dimethyl ammonium chloride; dieicosyl dimethyl ammonium chloride; didocosyl dimethyl ammonium chloride; di(hydrogenated tallow) dimethyl ammonium methyl sulfate; dihexadecyl diethyl ammonium chloride; dihexadecyl dimethyl ammonium acetate; ditallow dipropyl ammonium phosphate; ditallow dimethyl ammonium nitrate; di(coconut-alkyl) dimethyl ammonium chloride.

An especially preferred class of quaternary ammonium antistat/softeners of the invention correspond to the formula:

wherein R1 and R2 are each straight chain aliphatic groups of frorn 12 to 22 carbon atoms and X is halogen, e.g., chloride or methyl sulfate. Especially preferred are ditallow dimethyl ammonium chloride and di(hydrogenated tallow-alkyl) dimethyl ammonium chloride and di(coconut-alkyl) dimethyl ammonium chloride, these compounds being preferred from the standpoint of excellent softening properties and ready availability.

Nonionic fabric antistat/softener materials include a wide variety of materials including sorbitan esters, fatty alcohols and their derivatives. One preferred tvpe of nonionic fabric antistatic/softener material comprises the esterified cyclic dehydration products of sorbitol, i.e., sorbitan ester. Sorbitol, itself prepared by catalytic hydrogenation of glucose, can be dehydrated in well-known fashion to form mixtures of cyclic 1,4and 1,5-sorbitol anhydrides and small amounts of isosorbides. (See U.S. Patent 2,322,821) The resulting complex mixtures of cyclic any ides of sorbitol are collec tively referred to herein as "sorbitan". It will be recognized that this "sorbitan" mixture will also contain some free uncyclized sorbitol.

Sorbitan ester fabric antistat/softener materials useful herein are prepared by esterifying the "sorbitan mixture with a fatty acyl group in standard fashion, e.g., by reaction with a fatty (C10-C24) acid or fatty acid halide. The esterification reaction can occur at any of the available hydroxyl groups, and various mono-, di-, etc., esters can be prepared. In fact, complex mixtures of mono-, di-, tri-, and tetra-esters almost always result from such reactions, and the stoichiometric ratios of the reactants can simply be adjusted to favor the desired reaction product.

The foregoing complex mixtures of esterified cyclic dehydration products of sorbitol (and small amounts of esterified sorbitol) are collectively referred to herein as "sorbitan esters". Sorbitan mono- and di-esters of lauric, myristic, palmitic, stearic and behenic acids are particularly useful herein for conditioning the fabrics being treated. Mixed sorbitan esters, e.g., mixtures of the foregoing esters, and mixtures prepared by esterifying sorbitan with fatty acid mixtures such as the mixed tallow and hydrogenated palm oil fatty acids, are useful herein and are economically attractive.

Unsaturated Ci-Cis sorbitan esters, e.g., sorbitan mono-oleate, usually are present in such mixtures. It is to be recognized that all sorbitan esters, and mixtures thereof, which are essentially water-insoluble and which have fatty hydrocarbyl " tails", are useful fabric antistat/softener materials in the context of the present invention.

The preferred alkyl sorbitan ester fabric antistat/softener materials herein comprise sorbitan monolaurate, sorbitan monomyristate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monobehenate, sorbitan dilaurate, sorbitan dimyristate, sorbitan dipalmitate, sorbitan distearate, sorbitan dibehenate, and mixtures thereof, the mixed coconutalkyl sorbitan mono- and di-esters and the mixed tallowalkyl sorbitan monoand di-esters. The tri- and tetra-esters of sorbitan with lauric, myristic, palmitic, stearic and behenic acids, and mixtures thereof, are also useful herein.

Another useful type of nonionic fabric antistat/softener material encompasses the substantially water-insoluble compounds chemically classified as fatty alcohols. Monools, di-ols, and poly-ols having the requisite melting points and water-insolubility properties set forth above are useful herein. Such alcohol-type fabric conditioning materials also include the mono- and di-fatty glycerides which contain at least one "free" OH group.

All manner of water-insoluble, high melting alcohols (including mono- and diglycerides), are useful herein, inasmuch as all such materials are fabric substantive. Of course, it is desirable to use those materials which are colorless, so as not to alter the color of the fabrics being treated. Toxicologically acceptable materials which are safe for use in contact with skin should be chosen.

A preferred type of unesterified alcohol useful herein includes the higher melting members of the so-called fatty alcohol class. Although once limited to alcohols obtained from natural fats and oils, the term " fatty alcohols " has come to mean those alcohols which correspond to the alcohols obtainable from fats and oils, and all such alcohols can be made by synthetic processes. Fatty alcohols prepared by the mild oxidation of petroleum products are useful herein.

Another type of material which can be classified as an alcohol and which can be employed as a fabric antistat/softener material in the instant invention encompasses various esters of polyhydric alcohols, Such "ester-alcohol" materials which have a melting point within the range recited herein and which are substantially waterinsoluble can be employed herein when they contain at least one free hydroxyl group, i.e., when they can be classified chemically as alcohols.

The alcoholic di-esters of glycerol useful herein include both the 1,3-di-glycerides and the 1,2-di-glycerides. In particular, di-glycerides containing two C8C20, preferably C,,--C,,, alkyl groups in the molecule are useful fabric conditioning agents.

Non-limiting examples of ester-alcohols useful herein include: glycerol-1,2dilaurate; glycerol-1,3-dilaurate; glycerol-i ,2-myristate; glycerol-1,3-dimyristate; glycerol-1,2-dipalmitate; glycerol-1,3-dipalmitate; glycerol-1,2-distearate and glycerol1,3-distearate. Mixed glycerides available from mixed tallowalkyl fatty acids, i.e., 1,2ditallowalkyl glycerol and 1,3-ditallowalkyl glycerol, are economicaly attractive for use herein. The foregoing ester-alcohols are preferred for use herein due to their ready availability from natural fats and oils.

Mono- and di-ether alcohols, especially the C1-C18 di-ether alcohols having at least one free -OH group, also fall within the definition of alcohols useful as fabric antistat/softener materials herein. The ether-alcohols can be prepared by the classic Williamson ether synthesis. As with the ester-alcohols, the reaction conditions are chosen such that at least one free, unetherifiedOH group remains in the molecule.

Ether-alcohols useful herein include glycerol-1,2-dilauryl ether; glycerol-1,3-distearyl ether; and butane tetra-ol-1,2,3-trioctanyl ether.

The fabric antistat/softeners mentioned above are used as mixtures in combination with the imidazolinium salt of the invention. The additional agents are normally present in amount ranging from 1 to 12% by weight of the composition, preferably from 1 to 8%. Preferred mixtures are mixtures of the quaternary imidazolinium salt with a sorbitan ester, a fatty alcohol, or a quaternary ammonium compound. A most preferred mixture is the quaternary imidazolinium salt with ditallow dimethyl ammonium chloride (DTDMAC). These two compounds are preferably used in a weight ratio of from 80/20 to 20/80 and most preferably in a weight ratio of from 30/70 to 70/30 imidazolinium/DTDMAC.

Conventional liquid fabric conditioning composition components may be dissolved or dispersed in the composition. These conventional components include clay materials, aldehyde preservatives, emulsifiers, thickeners, opacifiers, coloring agents, brighteners, fluorescer

G. The propoxylated reaction mixture is finally charged with an alkylating agent in the form of dimethylsulfate. The amount of alkylating agent originally used is slightly less than the number of moles of imidazoline formed after step C above.

As the alkylation proceeds the pH of the reaction medium is monitored and addi tional dimethylsulfate is added until the pH is in the 5-7 range.

The product formed in the above reaction is 1-methyl-1-tallow-amidoethyl-2-tallow imidazolinium methylsulfate.

EXAMPLE II.

-The folowing compositions are prepared: A B Imidazolinium salt of 26.25 grams Eaxmple 1 Imidazolinium salt of ----- 26.25 grams Example I made without employing the propylene oxide step Aldehyde source 0.55 grams 0.55 grams Water q.s. to 1000 grams q.s. to 1000 grams The pH of both samples are adjusted to 5.8 with sodium hydroxide.

Compositions A and B are analyzed for remaining aldehyde after one week at the temperatures shown below. The amount of aldehyde originally in the compositions is 550 ppm.

Temperature A B 700F 510 ppm 470 ppm 100cm 508 401 1200F 464 346 The above figures demonstrate the improved aldehyde stability with the imidazolinium essentially free of amines and amine salts. Similar results are obtained with other imidazolinium salts made using polyamines and acylating or esterifying agents other than the diethylenetriamine and tallow triglyceride of Example I.

WHAT WE CLAIM IS: 1. A quaternary imidazolinium salt of the following structure:

wherein R and R1 are aliphatic or cycloaliphatic hydrocarbon groups having from 10 to 22 carbon atoms; R2 is an alkyl, substituted alkyl or aralkyl group having from 1 to 8 carbon atoms; R3 and R4 are hydrogen, hydroxy, alkyl having from 1 to 4 carbon atoms or hydroxy-alkyl having from 1 to 4 carbon atoms; D is a direct bond or a divalent organic radical, other than amino, having from 1 to 20 carbon atoms and composed of elements selected from C, O, N and H; and X is an anion and when D is a direct bond Rl can also denote a group from the imidazoline forming amine (as hereinbefore defined), which contains a total of less than 4% by weight of primary amines, secondary amines and/or cyclic tertiary amine salts based on the weight of the imidazolinium salt, as impurities.

2. A salt according to Claim 1, in the form of an aqueous solution in which the concentration of the imidazolinium salt is from 1 to 15% by weight.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (29)

1. **WARNING** start of CLMS field may overlap end of DESC **.

   G. The propoxylated reaction mixture is finally charged with an alkylating agent in the form of dimethylsulfate. The amount of alkylating agent originally used is slightly less than the number of moles of imidazoline formed after step C above.

   As the alkylation proceeds the pH of the reaction medium is monitored and addi tional dimethylsulfate is added until the pH is in the 5-7 range.

   The product formed in the above reaction is 1-methyl-1-tallow-amidoethyl-2-tallow imidazolinium methylsulfate.

   EXAMPLE II.

   -The folowing compositions are prepared: A B Imidazolinium salt of 26.25 grams Eaxmple 1 Imidazolinium salt of ----- 26.25 grams Example I made without employing the propylene oxide step Aldehyde source 0.55 grams 0.55 grams Water q.s. to 1000 grams q.s. to 1000 grams The pH of both samples are adjusted to 5.8 with sodium hydroxide.

   Compositions A and B are analyzed for remaining aldehyde after one week at the temperatures shown below. The amount of aldehyde originally in the compositions is

   550 ppm.

   Temperature A B 700F 510 ppm 470 ppm 100cm 508 401 1200F 464 346 The above figures demonstrate the improved aldehyde stability with the imidazolinium essentially free of amines and amine salts. Similar results are obtained with other imidazolinium salts made using polyamines and acylating or esterifying agents other than the diethylenetriamine and tallow triglyceride of Example I.

   WHAT WE CLAIM IS: 1. A quaternary imidazolinium salt of the following structure:

   wherein R and R1 are aliphatic or cycloaliphatic hydrocarbon groups having from 10 to 22 carbon atoms; R2 is an alkyl, substituted alkyl or aralkyl group having from 1 to 8 carbon atoms; R3 and R4 are hydrogen, hydroxy, alkyl having from 1 to 4 carbon atoms or hydroxy-alkyl having from 1 to 4 carbon atoms; D is a direct bond or a divalent organic radical, other than amino, having from 1 to 20 carbon atoms and composed of elements selected from C, O, N and H; and X is an anion and when D is a direct bond Rl can also denote a group from the imidazoline forming amine (as hereinbefore defined), which contains a total of less than 4% by weight of primary amines, secondary amines and/or cyclic tertiary amine salts based on the weight of the imidazolinium salt, as impurities.
2. 2. A salt according to Claim 1, in the form of an aqueous solution in which the concentration of the imidazolinium salt is from 1 to 15% by weight.
3. 3. A salt according to Claim 2, in which the concentration of the imidazolinium

   salt is from 2 to 8% by weight.
4. 4. A salt according to claim 2 or 3, in which the pH of the solution is from 4.5 to 7.
5. 5. A salt according to any of the foregoing claims, in which D denotes

   wherein n is a number from 1 to 6.
6. 6. A salt according to claim 5, in which D denotes
7. 7. A salt according to any of the foregoing claims in which R and R1 are aliphatic or cycloaliphatic hydrocarbon groups having from 14 to 20 carbon atoms.
8. 8. A salt according to claim 7, in which R and R1 are derived from tallow fatty acid.
9. 9. A salt according to any of the foregoing claims, in which R3 and R4 are hydrogen.
10. 10. A salt according to any of the foregoing claims, in which R2 is methyl and X is methylsulfate.
11. 11. A fabric conditioning composition comprising a salt according to any of the foregoing claims together with an organic fabric conditioning agent which is free of primary amines, secondary amines and/or cyclic tertiary amine salts in an amount of from 1 to 12% by weight.
12. 12. A composition according to claim 11, in which the additional fabric conditioning agent is a fatty nonionic or cationic material.
13. 13. A composition according to claim 12, in which the additional fabric conditioning agent is a quaternary ammonium compound, a fatty alcohol or a sorbitan ester.
14. 14. A composition according to claim 12, in which the additional fabric conditioning agent is di methyl ditallow ammonium chloride and the weight ratio of imidazolinium salt to dimethyl ditallow ammonium chloride is from 20/80 to 80/20.
15. 15. A salt according to claim 1, as hereinbefore specifically identified.
16. 16. A process for the production of a quaternary imidazolinium salt as claimed in claim 1 comprising the steps of: (a) reacting an acylating or esterifying agent having an aliphatic or cycloaliphatic hydrocarbon group containing from 10 to 22 carbon atoms associated with each acyl group with an alkylene or polyalkylene polyamine having two or three amino groups, one of which is a primary or secondary amino group in the 2 position to a primary amino group, the molar ratio of acyl groups to primary amine and hydroxyl groups being from 0.33 to 1.5:1 for a period of from 3 to 24 hours at a temperature of from 100"C to 2500C; (b) subjecting the reaction mixture to a vacuum of from 0.4 mm mercury to 10 mm mercury for from 1 to 8 hours to form an imidazoline product; (c) treating the imidazoline product mixture of step (b) with an alkoxylating agent in an amount equal to from 1% to 5% by weight of the imidazoline product mixture while maintaining the temperature at from 80"C to 140"C for a period of from 0.5 to 8 hours; and (d) treating the mixture of step (c) with an alkylating agent in an amount such that the molar ratio of alkylating agent to imidazoline is at least 1:1.
17. 17. A modification of the process according to claim 16, in which the molar ratio of acyl groups to primary amine and hydroxyl groups in step (a) is from 0.33 to 0.66 and the following step is inserted between steps (b) and (c), reacting the imidazoline product mixture of step (b) with an acylating or esterifying agent of the type in step (a) in a molar ratio of acyl groups to imidazoline product from 1:1 to 1.5:1 at a temperature of from 100"C to 250"C and for a period of from 1 to 24 hours.
18. 18. A process according to claim 16, in which the molar ratio of acyl groups to primary amine and hydroxyl groups is from 0.67 to 1.50:1.
19. 19. A process according to claim 18, in which an organic solvent in an amount equal to from 1% to 25% by weight of the imidazoline product mixture of step (b) is added along with the alkoxylating agent in step (c).
20. 20. A process according to any of claims 16 to 19, in which the aliphatic or cycloaliphatic hydrocarbon group associated with the acylating or esterifying agent in step (a) has from 14 to 20 carbon atoms.
21. 21. A process according to claim 20, in which the alkylene or polyalkylene polyamine in step (a) has the formula NH2CH2-CH,-NH-X wherein X denotes +CH2-CH+OH, CH,-CH,+,CH3, hydrogen or CH2-CH2+nNH2 wherein n is a number from 1 to 6.
22. 22. A process according to any of claims 16 to 21, in which the alkoxylating agent in step (c) is propylene oxide, ethylene oxide, butylene oxide, glycide or cyclohexane oxide.
23. 23. A process according to claim 22, in which the acylating or esterifying agent in step (a) is a glyceride ester of tallow fatty acid.
24. 24. A process according to claim 23, in which the alkylene or polyalkylene amine in step (b) is diethylenetriamine.
25. 25. A process according to any of claims 16 to 24 in which the alkylating agent in step (d) is dimethylsulfate.
26. 26. A process according to claim 16, when carried out substantially as described in Example I.
27. 27. A salt as claimed in claim 1, when produced by the process of any of claims 16 to 26.
28. 28. A method for conditioning fabric comprising the steps: (a) washing fabrics in an aqueous detergent bath containing a detergent; (b) rinsing the fabrics in an aqueous rinse bath; (c) adding to said rinse bath from 2 ppm to 500 ppm of a salt or a composition as claimed in any of claims 1 to 15 and 27; and (d) drying said fabrics.
29. 29. Fabrics when conditioned by the process of claim 28.