CA1208854A - Concentrated fabric softening compositions and methods for making same - Google Patents

Abstract

CONCENTRATED FABRIC SOFTENING COMPOSITIONS
AND METHODS FOR MAKING SAME
Abstract of the Disclosure Stable concentrated aqueous fabric softening compositions based on water-dispersible di-longchain, di-short chain quaternary ammonium salts are provided utilizing non-ionic surface active agents having an HLB value of from about 15.5 to 17.5, and water-soluble electrolyte. The softening component comprises from about 12-20% by weight of the composition; the non-ionic agent from about 1 to about 5% by weight and the electrolyte from about 0.1 to about 1.5% by weight. Methods for making the composition are also described.

Description

~Z~3 !359 The-~resent invention relates to fabric softener compositions adapted for the use in the rinse cycle of a laundering process and in particular to concentrated aqueous fabric softener compositions which are stable at both low and high ambient temperatures, i.e.
such compositions do not form a gel, and which are easily dispers-ed in water when used.
Compositions containing quaternary ammonium salts having at least one long chain hydrocarbyl group are commonly used to pro-vide fabric softening benefits when employed in a laundry rinse operation; for example, see United States Patents 3,349,033; 3,644,203;
3,946,115; 3,997,453; 4,073,735 and 4,119,545.
~or most aqueous softener compositions containing cationic quaternary ammonium compounds as active ingredients, the concen-tration of such cationics has, in general, been limited to the range of about 3 to 6% by weight (see United States Patent 3,904,533 and United S~ates Patent 3,920,565~. Such a low concentration is generally necessitated by the fact that cationics form gels in water systems at concentrations at above about ~%, and while the use of elec-trolytes to lower ~he viscosity of such compositions is known (see in particular United States Patent 4,199,545), such electrolytes are far from satisfactory. From a functional point of view, the electrolytes often do not perform as required particularly at con-centrations of the cationics in the neighbourhood of about 12-15%.
~urther, while the performance of the electrolytes may mitigate some of the gelling problem, their use is far from satisfactory f - .
'~

~Z~ S4 in providing a highly concentrated aqueous system of cationics which does not gel or severely change in viscosity wi-thin the usual range of temperatures encountered in the handling thereof, for example 0 F (about -18 C) up to about 140F (about 60C). In U.S. Patent 3,681,241 a concentrated fabric softening emulsion is described which consists essentially of 3.5 to 6. 5 parts by weight of a compound represen-tecl for example by distearyl dimethyl ammonium chloride,from 3.5 to 6.5 parts by weight of an alkyl amido imidazolinium alkylsulfate,and from 0 to 3 parts by weight of a different but similar fatty amido imidazolinium alkylsulfate, the latter alleged]y providing low temperature stability f`or the composi-tion. The total actives contemplated range from about 8 to 13%.
In British application 2053249A published February 4, 1981, there are disclosed ca-tionic fabric softening compositions con-taining ] 5 to 60% by weight of cationic softener, 25 to 75% by weight of an aqueous medium, and 0. 5 to 40% by weight of a specified water soluble polymer.
In U.S. Patent 3,97LI,076 there are disclosed quaternary ammonium-containing softening COmposition of conventional cationic concentrations, i.e. about 3% to about 6%. These compositions are characterized by the very small par-ticle size of the substantially water-insoluble quaternary ammonium softening compound, i.e. 90~
by weight of the quaternary ammonium compounds exist as particles which will pass through a 1. 2 micron filter. The compositions are described as a combination of the cationic softener, a C8 to C20 12~8~59~
alkyl alcohol with Erom about 0.1% to about 2.0% of a non-ionie surfactant having a HLB of from about 8 to about 15, and preferably from about 10 -to about 14. The preferred non-ionics have a llpophilic hydrocarbyl moiety equivalent of 9 to 15 carbon atoms with 7 to 13 ethylene oxide hydrophilic moie-ties.
This patent does not relate to -the problem of stability of concentrated aqueous cationic softening compositions but ra-ther to improving the level and uniforrnity of softening using conventional concentrations.
The present invention provides low and high tempera-ture stable, concentrated, aqueous softener compositions based upon quaternary ammonium softening compounds and a minor amount of both a nonionic surfactant and an electrolyte. The present invention also provides a method by which highly concentrated fabric softening compositions are produced.
Thus, according to the present invention, there is provided a stable, aqueous, concentrated fabric softening composition comprising about (A) 12 to 20% by weight of a cationie softener of the formula:

\ N < X

wherein R1, R2, R3 and R4 are alipha-tlc radials of C1 to C30 with at least two being alkyl of C14 to C30 and X is a water-solubilizing anion; (B) 1 to 5% by weight of a non-ionie sur-factant having an HLB value of 16.5-1.0; and (C) 0.5 to about 5% by weight of an electrolyte.
In another aspect, the invention provides a method of preparing a composition as defined above, which comprises first preparing an aqueous solu-tion of the non-ionie surfactan-t ..
,~ - 4 -~2C~i!385fl~

in warm water at a temperature up to about 80C thereaf-ter adding cationic softener in melted form to form a gel, cooling said gel to below 40C, and then adding electrolyte to break the gel.
The compositions of the present invention are stable aqueous compositions which con-tain a high concentration of the cationic fabric softener which is a water dispersible quaternary ammonium compounds as hereinafter described, non-ionic surfactant and electrolyte.

,~" - 4~ -The aqueous compositions of this invention contain at least about 12% cationic softener up to about 20% -thereof, said cationic softener having the general formula I
R -~
R -R Y

wherein the R groups are selected from Cl to C30 aliphatic, pre-ferably alkyl or alkenyl, aryl (e.g. phenyl, tolyl, cumyl, etc.);
aralkyl (e.g. benzyl, phenethyl, etc.); and the halo, amide, hydroxyl, and carboxy substituents thereof; with the proviso that e R is C14 to C30 and preferablY C14 to C18 and the others are lower alkyl,and more preferably at leas-t two R's are C14 to Clg and the others are lower alkyl of Cl to C4 (and most preferably methyl or ethyl),and Y is a water-solubili~ing anion such as chloride,bromide, iodide,fluoride, sulfate, me-thosulfate, nitrite, nitrate, phosphate and carboxylate (i.e. acetate, adipate, propionate, phthalate, benzoate, oleate, e-tc.). Typical cationics of formula I include the following:
distearyl dimethyl ammonium chloride ditallow dimethyl ammonium chloride dihexadecyl dimethyl ammonium chloride distearyl dimethyl ammonium bromide di(hydrogenated tallow) dimethyl ammonium bromide distearyl, di(isopropyl) ammonium chloride distearyl dimethyl ammonium methosulfate ~za~s~

The non-ionic component of the present compositions com-prises from about 1 to about 5% by weight of the composition and generally may vary with the cationic softener in a weight ratio of cationic to nonionic of from about 20:1 to about 3:1 and preferably from about 10:1 to about 5:1. The non-ionic compounds are ethylene oxide condensates of C12 to C20 aliphatic alcohols and alkyl phenols characterized by an HLB (hydrophilic-lipophilic balance) of 16.5 _ 1Ø A complete discussion of the HLB system can be found in "The HLB System" (1976 Edition 16 pages) pub-lished by ICI United States, Inc. Generally the non-ionics as herein contemplated are hydrophilic in nature with a large and strong hydrophilic group. In the present invention this group is an oxyethyl chain generally of at least about 15 terminal oxy-ethyl groups (i.e. the oxyethyl groups are contiguous and termin-ate in an hydroxyl group).
Particularly suitable non-ionic surfactants include a C13 15 aliphatic alcohol containing 20 moles of condensed ethyl-ene oxide and available as Synperonic A20; an e-thoxylated octyl phenol with 16 moles of ethylene oxide available as Triton X-165 and an ethoxylated nonyl phenol with 30 moles of ethylene oxide available as Dowfax* NP30.
A third preferred ingredient is an electrolyte (ionic) material in an amount of from about 0.1 to about 1.5~ by weight.
The use of an electrolyte acts not only to control viscosity but also assists in stabilizing the system against gelling and phase * Trade ~lark ~ - 6 -B~S4 inversion at high temperatures e.g. above about 40C.
Particularly suitable electrolytes include sodium chloride and calcium chloride. Other useful electrolytes include sodium formate, sodium nitrite, sodium nitrate, sodium ace-ta-te among others as well as water-soluble salts of other cations such as potassium,lithium, magnesium ammonium and the like.
Minor amounts of lower alkanols may be used particularly where it is desired to further modify the viscosity. In general, alcohols tend to lower the viscosity at ambient temperatures, although moderate amounts may effect a lowering of the phase inversion temperature. The preferred compositions of this inven-tion exhibit phase inversion temperatures above about 80C and preferably above abou-t 90 C with amounts of alcohol in the range of about 1 to about 10~ by weight. Particularly suitable alcohols are ethyl and isopropyl alcohol.
In addi-tion to the foregoing components of the sof-tening compositions of this invention, there may also be included numerous conventional, sup-plemental, and optional ingredients which do not adversely affect the stability and/or functional characteristics of the instan-t compositions. Thus, for example, there may be present -the ubiquitous perfumes, dyes, pigments, opacifiers, germicides, optical brigh-teners, anti-corrosion agents (e.g.
sodium silicate) water-soluble polymers, an-ti-static agents and the like. Where used, each may comprise from 0.01~ to about 5 by weight of the composition.

:~L2~ 35~

It is, of course, recognized and understood that mos-t available chemical materials and particularly those containing an hydrocarbyl moiety are generally mixtures of closely rela-ted moieties. Thus, -the long chain alkyl substituents (R) in the cationics used in -this invention may not only be a single carbon length chain but more probably a mixture. In this regard a particularly useful quaternary set wherein the alkyl groups are derived from tallow may contain about 35% C16 and 60% Cl8 and minor amounts of C14 and even others. Similarly, the aliphate alcohol percursors for the non-ionics used herein may be of a single carbon chain length but more likely, again, it will and can be a mixture in any propor-tion of the operable chain length compounds.
The fabric softening compositions of this invention must have in addition to viscosity and phase stability, the requisite vis-cosity (i.e. for pourability) and water-dispersibility in the rinse cycle (or any other form of dilution prior to use) which the consumers have come to accept and demand from -their use of the less concentrated products. Thus the products contemplated herein may have viscosities ranging from about 30 cps -to about 250 cps and preferably from about 40 cps to about 120 cps.
The general procedures for preparing the compositions herein are several in number, -the final produce varying somewhat in stability. The procedures differ in -the order of material addition as well as processing conditions.

- 8 ~

S~

A preferred procedure (A) involves adding -the non-ionic materials and coloring to the formula weight of water which is at about 70C. To this solution slowly add the cationic sof-tener in melted form. Usually a gel wi:Ll f`orm. The mixture is cooled to about 40 C and then the electrolyte is added to break the gel.
The composition is then cooled to room temperature with stirring.
A modification o~ procedure (A) involves adjus-ting the pH to about 12 before adding the melted cationic. In this case no gel forms.
After cooling to about 40 C, the pH is readjusted to 5 to 6, cooled with stirring to room temperature and then electrolyte is used to adJust the viscosity (Procedure B). Still another procedure (C) involves adding the non-ionics to at least 80~ of warm water (not above about 40C), then the electrolyte, and finally the melted ca-tionic. The rest, if any, of the water is then added, and the composition is then cooled with agita-tion to room termpera-ture.
The following examples will serve to illustrate the present invention without being deemed limitative thereof. Parts are by weight unless o-therwise indicated.
Example 1 Eollowing Procedure (A) described above, 2 parts of an ethoxylated nonyl phenol (containing 16 moles of ethylene oxide) are dissolved in about 75 parts of water at a temperature of about 70C. To this solution are slowly added 20 parts of distearyl dimethyl ammonium chloride (75% active and containing 385~

about 10% isopropanol and the balance water) in melted ~orm (Temperature = 55C) with stirring. A gel is formed. The gel is cooled down to about 40C and -then 0.5 parts of calcium chloride dehydrate are added. The mixture is cooled to room temperature (about 20C) with stirring. A stable produc-t resul-ts with a viscosity of about 100 cps.
Example 2 The procedure o~ Example 1 is repeated utilizing the follo~ing parts o~ (A) cationic (active), (B) surfactant, and (C) electrolyte (a) A - 12; B = 1.0; C = 0.5 (b) A = 1ll; B = 1.5; C = 0.5 (c) A = 16; B = 1.8; C = 0.7 (d) A = 18; B = 2.5; C = 1.0 Example 3 Examples 1 and 2 are repeated utilizing in place o~ distearyl dimethyl ammonium chloride the following:
(a) ditallow dimethyl ammonium chloride (b) distearyl dimethyl ammonium methosulfate (c) di(hydrogenated tallow) dimethyl ammonium bromide (d) di-hexadecyl dimethyl ammonium chloride (e) distearyl diethyl ammonium chloride Example ll Examples 1, 2 and 3 are repeated adding in all instances 1 part of polyethylene glycol (MWI~OO) with the non-ionic in the -- 1.0 --~L2~
first step of the process of the preparation.
Polyethylene glycol (MW400) is illus-trative of low molecular weight. water-soluble polymers which may be used if desired in the softening compositions of this invention.
Among other useful polymers reference is made to Bri-tish pub-lished application 2053249A described above. The compositions of this invention may include any and all oE such polymers and other water-soluble polymers as well. In the composi-tions of this invention one may use from 0.1% to 20% by weight of the total composition of these materials.
Example 5 Each of the foregoing examples l to 4 is repeated using as the electrolyte the following:
(a) sodium chloride (b) sodium nitrate (c) sodium Eorma-te (d) ammonium bromide (e) potassium chloride (f) calcium ni-trate (g) lithium acetate (h) magnesium chloride Example 6 Each of Examples l to 5 is repeated, composition-wise, but following the Procedure (B) for making -the composi-tions. In this procedure the change in -the processing described in Ex~mple l involves adjusting -the pH to 12 with sodium hydroxide after dissolution of -the non-ionic (and polyethylene glycol where used), and readjusting -the pH -to 5-6 wi-th hydroch:Loric acid after the 8~5~L

addition of the cationic. At this point no gel forms as in Procedure (A). The electrolyte is added after the mixture has been cooled to room temperature.
Examp:le 7 Each of Examples 1 -to 5 is repeated again, composition-wise but folJowing Procedure (C) to prepare the cornpositions.
In this procedure the non~-ionic (and the water soluble polye-thylene glycol where used) is dissolved in 80% of the formula weight of water at a temperature of 35-40C. The electrolyte is then added, followed by -the melted cationic. The remaining formula weight of water is then added and thereaf-ter the mixture is cooled to room temperature with stirring.
The aqueous softening composi-tions of -this invention are generally applicable as other such compositions, particularly useful in the rinse cycle of an automatic laundry machine. In such operations as well as in any other desired method of treating clothes, the compositions are usually employed to provide generally an actives concentration of from about 0.005% to 0.3%
based on the weigh-t of clothes treated preferably 0.007% to about 0.2% and most preferably from abou-t 0.01~ to about 0.15%.

Claims (10)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A stable, aqueous, concentrated fabric softening composition comprising about (A) 12 to 20% by weight of a cationic softener of the formula:

wherein R1, R2, R3 and R4 are aliphatic radials of C1 to C30 with at least two being alkyl of C14 to C30 and X is a water-solubilizing anion; (B) 1 to 5% by weight of a non-ionic surfactant having an HLB value of 16.5?1.0; and (C) 0.5 to about 5% by weight of an electrolyte.

2. A composition as defined in Claim 1 wherein A is distearyl dimethyl ammonium chloride.

3. A composition as defined in Claim 2 wherein the nonionic surfactant is an ethoxylated nonyl phenol containing an average of about 16 moles of ethylene oxide.

4. A composition as defined in Claim 1 wherein the ratio of (A) to (B) is about 20:1 to 3:1.

5. A composition as defined in Claim 4 wherein the amount of compound (A) is about 12% and that of (B) is about 2%.

6. A composition as defined in Claim 1 wherein the total softener concentration is about 12 to 15% by weight.

7. A method for preparing a composition as defined in Claim 1 which comprises first preparing an aqueous solution of the non-ionic surfactant in warm water at a temperature up to about 80°C thereafter adding cationic softener in melted form to form a gel, cooling said gel to below 40°C, and then adding electrolyte to break the gel.

8. A method as defined in Claim 7 wherein the warm water temperature is about 70°C, the gel is cooled to just below 40°C
and after the gel is broken the mixture is cooled to room temperature with stirring.

9. A method for preparing a composition as defined in Claim 1 which comprises first preparing an aqueous solution of the non-ionic surfactant in warm water at a temperature of up to about 80°C, adjust the pH with alkaline material to above about 10, add the cationic softener in melted form, readjust the pH
to below 7, cool to about room temperature and then add electro-lyte to adjust the viscosity.

10. A method for preparing a composition as defined in Claim 1 which comprises first preparing an aqueous solution of the non-ionic surfactant then adding electrolyte followed by the cationic softener in melted form and cool to room temperature.