EP0203626A2

EP0203626A2 - Detergent containing a fabric conditioner

Info

Publication number: EP0203626A2
Application number: EP86200431A
Authority: EP
Inventors: Andre Baeck; Alfred Busch
Original assignee: Procter and Gamble European Technical Center
Current assignee: Procter and Gamble European Technical Center
Priority date: 1985-03-28
Filing date: 1986-03-19
Publication date: 1986-12-03
Anticipated expiration: 2006-03-19
Also published as: GR860813B; GB2172910B; FI861338A0; GB2172910A; GB8508128D0; EP0203626A3; FI861338A; MX164050B; JPS61275393A; EP0203626B1; IE58609B1; IE860832L; DE3681344D1

Abstract

Intimate mixtures of certain amines and a Bronstedt acid are useful for mixing with conventional detergent ingredients to provide through-the-wash fabric softening.

Description

TECHNICAL FIELD

The present invention relates to detergent compositions having fabric softening properties. Certain amines (in intimate mixture with a dispersing aid) in the compositions provide through-the-wash softness and anti-static benefits. Detergent compositions in spray-dried form containing said amines are disclosed. Preferred compositions also contain a smectite clay for additional softening benefits.

Background

The use of softeners to treat fabrics subsequent to a washing operation is a well known laundering practice. Fabric softeners are, in the main, cationic materials which are incompatible with anionic detersive surfactants used in most fabric washing compositions. For that reason, the softening operation is generally carried out in the laundry rinse bath after the surfactant has been removed from the washing machine. This entails additional work for the user.
Formulators of fabric laundering compositions have long sought means whereby the fabric washing and softening could be done concurrently. Methods employing clay softeners, mixtures of clay and various amine materials, and the like, are described in the following patents: German 29 64 114, 28 57 163, 24, 39 541, 23 34 899 and EPO 0 023 367, 0 026 528 and 0 028 432.
The use of mixtures of amines and soaps (salts of fatty acids) as through-the-wash softeners is disclosed in U.K. patent 1 514 276. The amines of this reference are selected on the basis of their having an isoelectric point of from 8.3 to 9.8 i.e. such that they have no positive charge during the wash cycle, and become positively charged during the rinse cycle.
The present invention employs a certain class of amines, intimately mixed with a dispersing aid, in an otherwise conventional detergent composition matrix, and optionally clay, to provide cleaning and, concurrently, softening.

Summary of the invention

The compositions herein may be described succinctly as detergent compositions (preferably, granular) which may contain conventional detergent ingredients such as detersive surfactants (including anionics), detergency builders, optical brighteners, detersive enzymes, fabric bleaches, and the like, all at conventional levels, as well as clay fabric softeners (preferably, smectite clays), said compositions being characterized in that they contain at least 0.1 % (preferably 1.0 % to 20 %) of an amine having an isoelectric point of at least 9.5, preferably those of the formula R₁R₂R₃N, wherein R, is C. to C₂₀ hydrocarbyl and R₂ and R₃ are each C. to C₄ hydrocarbyl, C₂ to C,_o alkoxylated hydrocarbyl or hydrogen, the amine being in intimate mixture with a dispersing aid.

Detailed Description of the Invention

As noted hereinafter, the compositions of this invention comprise, in major part, conventional ingredients that are quite familiar to formulators of granular detergent compositions.
Surprisingly, the amines used herein are entirely compatible with such conventional detergent ingredients, even anionic surfactants.

Amine

The amines suitable for the compositions herein are selected so that they have an isoelectric point in excess of 9.5, preferably in excess of 10.0.
Examples are amines having general formula R₁R₂R₃N₄ wherein R, is C₈ to C₂₀ hydrocarbyl, preferably C₈ to C₂₀ alkyl, more preferably C₁₀ to C₁₄ alkyl, and most preferably C,, alkyl or a mixture of C₁₂ and C,, alkyl.
R₂ and R₃ are each, independently, C, to C₁₀, hydrocarbyl, or hydrogen. Examples of suitable hydrocarbyl radicals are C, to C, alkyl or hydroxyalkyl, and C₂ to C,_o alkoxylated alkyl, in particular ethoxylated alkyl radicals. Amines wherein R₂ and R₃ are identical C, to C₄ alkyl, especially methyl, are preferred.
Prior to incorporation into the detergent matrix, the amines are intimately mixed with a dispersing aid. The dispersing aid can be any of a number of such materials. Specific examples include nonionic surfactants, and emulsifiers, like those used in the food industry. Examples of the latter include glycerol esters, e.g. lecithin.
It has been found that a specific class of compounds, most of which are not generally considered to be dispersing aids, are particularly suitable to be used as dispersing aids in combination with the amines defined herein. This class of compounds consists of the Bronstedt acids having a pKa value of not greater than 6, preferably not greater than 5.
Examples of such acids include inorganic acids like HF, HCI, HBr, H₂SO₄, HNO₃, HNaSO,, H₂SO₃, HNaSO₃, phosphoric acid esters, like R'(CH₂CH₂O)-_mPO(OH)₂ and (R'O(CH₂CH₂0) _m). POOH, wherein R' is a C₃-C₂₀ hydrocarbyl, and m has a value in the range of from 1 to 6; organic acids, like carboxylic acids, polycarboxylic acids, hydroxycarboxy acids, hydroxypolycarboxy acids, aminocarboxy acids, phosphoric acids, polymeric carboxy acids, alkylether carboxy acids, and alkylsulforic acids. Particularly suitable for use as dispersing aids herein are carboxylic acids of the formula RCOOH, wherein R is hydrogen or C, to C,5 alkyl. Preferred acids are formic acid (R is hydrogen) and lauric acid (R is C₁₁H₂₃ n-alkyl).
Although not intended to be limited by theory, a possible mechanism by which Bronstedt acids act as dispensing aids could be as follows. The acids protonate a portion of the amine. The protonated amine, in turn, acts as a dispersing aid for the remaining unprotonated amine. This mechanism suggests that protonated aminesoer secould be used as dispersing aids, instead, or in combination with the Bronstedt acids.
The criticality of the high isoelectric point of the amines (at least 9.5, preferably 10.0 or higher) - suggest that it is important that, if protonation indeed takes, place, the amines remain protonated during the wash cycle of a laundry program. On the other hand, it is critical that the dispersing aid be intimately mixed with the amine. Simply allowing the amines to be contacted by the dispersing aid in the wash liquor apparently is not sufficient to obtain the superior softening performance.
In general terms, the amine/dispersing aid mixtures which are key to this invention are prepared separately from the balance of the composition and then added to the conventional detergent ingredients. If the dispersing aid is a Bronstedt acid, this can most conveniently be done by preparing a melt (preferably 1:1 mole ratio) of the acid and the amine and maintaining under continuous mixing the melt stage for about ten minutes whereby the complex forms.
If the detergent matrix is in granular form, the amine/dispersing aid melt can be sprayed onto the granules. Alternately, the melt can be allowed to solidify, then reduced to the desired particle size in, e.g. a colloid mill, and dry-mixed with the detergent granules.
If the detergent matrix is a liquid, the amine/dispersing aid melt can be dispersed into the liquid detergent mixture, or be allowed to solidify, milled to the desired particle size (typically smaller than used in conjunction with granules) and then dispersed into the liquid.
The amine/dispersing aid can also be deposited on a sheet, e.g. by coating a sheet with the melt. The sheets may be added to the wash liquor during the wash cycle of a laundering process. The sheets may further contain conventional detergent ingredients. Sheets of the type as has been disclosed for use as a delivery system for detergent ingredients are generally suitable for use herein.
If the dispersing aid is an acid, the molar ratio amine : acid preferably is about 1:1, but good fabric softening results can also be obtained by mixing the amine with a sub-stoichiometric amount of acid. For good results, the acid : amine ratio should be at least 1:10, preferably at least 1:5.
The amine/dispersing aid mixtures are typically used herein at levels of at least 0.1 %, typically at levels of 0.5 % to 20 %, most preferably from 1 % to 10 % of the detergent compositions, especially when softener clay is present.

Softener Clay

The protonated amine is preferred, but not limited, for use in combination with a detergent- compatible clay softener. Such clay softeners are well known in the detergency patent literature and are in broad commercial use, both in Europe and in the United States. Included among such clay softeners are various heat-treated kaolines and various multi-layer smectites. Preferred clay softeners are smectite softener clays that are described in German patent document 2 334 899 and in U.K. patent 1 400 898, which can be referred to for details. Softener clays are used in the preferred compositions at levels of at least 1 %, generally 1-20 %, preferably 2-7 %.

Detersive Surfactants

The.compositions of this invention will typically contain organic surface-active agents - ("surfactants") to provide the usual cleaning benefits associated with the use of such materials.
Detersive surfactants useful herein include well known synthetic anionic, nonionic, amphoteric and zwitterionic surfactants. Typical of these are the alkylbenzene sulfonates, alkyl-and alkylether sulfates, paraffin sulfonates, olefin sulfonates, alkoxylated (especiallyethoxylated) alcohols and alkyl phenols, amine oxides, a-sulfonates of fatty acids and of fatty acid esters, and the like, which are well known from the detergency art. In general, such detersive surfactants contain an alkyl group in the C₉-C₁₈ range; the anionic detersive surfactants can be used in the form of their sodium, potassium or tri-ethanolammonium salts; the nonionics generally contain from about 5 to about 17 ethylene oxide groups. U.S. Patent 4.111.855 contains detailed listings of such typical detersive surfactants. C,, - C,₆ alkyl benzene sulfonates, C₁₂C₁₈ paraffin sulfonates and alkyl sulfates, and the ethoxylated alcohols and alkyl phenols are especially preferred in the compositions of the present type.
Also useful herein as the surfactant are the water-soluble soaps, e.g. the common sodium and potassium coconut or tallow soaps well known in the art.
The surfactant component can comprise as little as 1 % of the compositions herein, but preferably the compositions will contain 5 % to 40 %, preferably 10 % to 30 % of surfactant. Mixtures of the ethoxylated nonionics with anionics such as alkyl benzene sutfonates, alkyl sulfates and paraffin sulfonates are preferred for through-the-wash cleansing of a broad spectrum of soils and stains from fabrics.
Detersive Adiuncts -The compositions herein can contain other ingredients which aid in their cleaning performance. For example, it is highly preferred that detergent compositions contain a detergent builder and/or metal ion sequestrant. Compounds classifiable and weft known in the art as detergent builders include the nitrilotriacetates, polycarboxylates, citrates, water-soluble phosphates such as tri-polyphosphate and sodium ortho-and pyro-phosphates, silicates, and mixtures thereof. Metal ion sequestrants include all of the above, plus materials like ethylenediaminetetraacetate, the amino-poly- phosphonates (DEQUEST) and a wide variety of other poly-functional organic acids and salts too numerous to mention in detail here. See U.S. Patent 3.579.454 for typical examples of the use of such materials in various cleaning compositions. In general, the builder/sequestrant will comprise about 0.5 % to 45 % of the composition. The 1-10 micron size zeolite (e.g. zeolite A) builders disclosed in German patent 2.422.655 are especially preferred for use in low phosphate compositions which contain the amine fatty acid complex.
The laundry compositions herein also preferably contain enzymes to enhance their through-the-wash cleaning performance on a variety of soils and stains. Amylase, protease and lipase enzymes suitable for use in detergents are well known in the art and in commercially available liquid and granular detergents. Commercial detersive enzymes - (preferably a mixture of amylase and protease) are typically used at levels of 0.001 % to 2 %, and higher, in the present compositions.
Moreover, the compositions herein can contain, in addition to ingredients already mentioned, various other optional ingredients typically used in commercial products to provide aesthetic or additional product performance benefits. Typical ingredients include pH regulants, perfumes, dyes, bleach, optical brighteners, soil suspending agents, hydrotropes and gel-control agents, freeze-thaw stabilizers, bactericides, preservatives, suds control agents, bleach activators and the like.
In a through-the-wash mode, the compositions are typically used at a concentration of at least 500 ppm, preferably 0.10 % to 1.5 %, in an aqueous laundry bath at pH 7-11, preferably at pH 9-11, to launder fabrics. The laundering can be carried out over the range of 5°C to the -boil, with excellent results.

Industrial Application

the following examples are typical of the preferred compositions of this invention containing smectite softener clays, but are not intended to limit the scope of the invention

Example I

Lauric acid and lauryl N,N-dimethyl amine (1:1 mole ratio) are admixed, melted in a jacketed batch, and maintained under continuous mixing as a melt for about 10 minutes (excess heating may cause yellowing).
A detergent composition is formulated as follows:
The detergent matrix is prepared as a crutcher mix and spray-dried into granules in standard fashion. The amine/lauric acid mixture is sprayed onto the granules, as well as the perfume. Enzymes are dry-mixed.
The composition of Example I is free-flowing and exhibits excellent through-the-wash fabric softening performance when fabrics washed therewith are line-dried.

Example II

A nil-P spray-dried detergent formulation is as follows :
In an optional mode, the composition of Example II may be modified by removing the clay and replacing it with an equivalent amount (with regards to softening performance) of amine-acid mixture.
In another alternative composition,the clay is replaced with ditallowmethyl-amine.

Example III

The following composition is prepared as in Example I.

Example IV

Preparation of the dimethyl myristyl amine/citric acid mixture
Citric acid is dissolved in methanol (at ca. 30°C). After the addition of the amine, the mixture is stirred for about 15 minutes. Then the methanol is evaporated (e.g. by heating) and the solid residue (mixture of citric acid/dimethyl myristyl amine) is subsequently dried and ground to the desired particle size.
This method for preparing the mixture of amine/dispersing aid is suitable when the melting point of the dispersing aid is too high.

Claims

1. A detergent composition comprising detersive sulfactant, builders, and conventional detersive ingredients, characterized in that it contains at least 0.1 % of an intimate mixture of an amine having an iso-electric point of at least 9.5, and a dispersing aid.

2. A composition according to claim 1 wherein the amine has an iso-electric point of at least 10.0.

3. A composition according to claim 1 or 2 wherein the amine has the formula

R₁R₂R₃N wherein R, is C. to C₂₀

hydrocarbyl, and R2 and R3 are each C, to C₄

hydrocarbyl, C₂ to C₁₀ alkoxylated hydrocarbyl, or hydrogen.

4. A composition according to any of claims 1 to 3, wherein the dispersing aid is a Brondstedt acid having a pKa value not greater than 6, preferably not greater than 5.

5. A composition according to any of the preceding claims wherein the dispersing acid is a carboxylic acid of the formula R COOH, wherein R is a hydrogen or a C, to C,_s hydrocarbyl, preferably formic acid or lauric acid.

6. A composition according to any of the preceding claims wherein the amine and the dispersing aid are present in an (amine): (dispersing aid) molar ratio in the range of from 10:1 to 1:5.

7. A composition according to any of the preceding claims which contains from 0.5 % to 20 % of the amine/dispersing aid mixture.

8.A composition according to any of the preceding claims wherein the amine/dispersing aid is prepared by admixing same at a temperature above the melting point of both the amine and the dispersing aid.

9. A composition according to any of the preceding claims which additionally contains a clay softener, preferably a smectite clay.

10. A composition according to any of the foregoing claims which comprises:

a) from 1 % to 10 % of an intimate mixture of lauryl-N,N-dimethyl amine and lauric acid in a molar ratio as from 1:0.9 to 1:1.1;

b) from 2 % to 7 % of a smectite clay softener;

c) the balance comprising conventional detergent ingredients at conventional levels;

said composition being in the form of spray-dried granules.

11. A sheet suitable for addition to a wash liquor, having dispersibly associated therewith a fabric softening amount of the amine/dispersing aid mixtures of any of the preceding claims.