GB2160886A - Detergent article having softening action and process for its preparation - Google Patents

Abstract

A solid detergent bar article possessing softening properties vis-à-vis the fabrics subjected to washing comprises: a) 1-50% by weight of an anionic, nonionic, amphoteric, cationic or zwitterionic surfactant, b) 1-50% by weight of a specified builder c) 0-1 0% by weight of a long chain aliphatic amide or amine oxide; d) 0-5% by weight of a cellulosic derivative, e) 10-50% by weight of a softening agent containing at least one of i) 0-50% by weight of a quaternary ammonium salt of formula (R1,R2,R3, R4N)<+>Y<-> wherein one at least of the R radicals is a C16-C22 aliphatic radical and Y is a halide, sulphate or methylsulphate, or an imidazolinium salt; ii) 0-20% by weight of a tertiary amine of formula R1R2R3N wherein at least one of the R radicals designates a C10-C18 saturated alkyl radical; iii) 0-40% by weight of a smectic clay having an ionic exchange capacity higher than 50 meq/100 grams of clay; f) 0-15% by weight of talc or 0-10% of aluminium formate, or of calcined sodium carbonate; and g) 0-5% by weight of minor components. y

Description

SPECIFICATION Detergent article having softening action and process for its preparation The present invention provides a novel solid article which offers a combination of detergent and softening properties on synthetic or natural fiber fabric materials.

The terms "fabric softener" have acquired a special meaning in the art where they are interpreted to define those products capable of exerting a specific action on washing. Such an action confers lightness and freshness to fabrics which are thus rendered soft and pleasant to the touch. This action also eliminates, or at least reduces the electrostatic charges which accumulate on fabrics, especially of synthetic fiber origin, namely after the process of washing and drying.

The prior art describes a variety of products destined to such a use. Their efficiency depends however on the mode of application. Thus, quaternary ammonium salts have been suggested as particularly active products when employed after the washing cycle. In effect, the cationic nature of these salts determines their reactivity with the usual anionic surfactants and their utilisation is therefore limited. On the other hand, if these products are pre-mixed in a sole article, they have the tendency to react one with another after having been added to a washing solution with the consequence that both the detergent action and the softening effect are lessened.

Several compositions intended to minimize the mutual reactivity of anionic and cationic agents have been described in the past. These compositions include "compatibility" agents, such as those described e.g. in U.S. Patent N" 3,886,075 and 3,954,632. A great variety of other compositions have been suggested in European Patent Application published under N" 76 572 on April 13, 1983.This application describes also a product with both detergent and softening action which product occurs under the form of distinct particles of 10 to 500 Fm and possesses a maximal solubility of 50 ppm at 25"C and a softening point of between 90 and 200"F (32.2" and 93.3"C.) These products are particularly well adapted to the washing habits of industrialized countries wherein the consumer can generally have at his disposal at home modern mechanical washing means. In reality, experience has shown that in several countries the widest used detergents are not in powder form but occur under the form of a brick or of a solid bar. Under these forms, detergents are better adapted to a use more conforming to the local habits of washing which in most of the cases is effected manually.

It is a fact that the known presently commercialized products available in bar form have a detergent action without however satisfying the double requirement of washing and softening.

The instant invention is based on the discovery that it was possible to manufacture a solid detergent article in bar form that possessed a softening action on the fabric subjected to washing by intimately mixing the following ingredients a) 1-50% by weight of a surfactant belonging to the group of anionic, nonionic, amphoteric, cationic or zwitterionic surfactants or mixtures thereof; b) 1-50% by weight of an organic or inorganic alkali salt belonging to a group of tripolyphosphates, nitrilotriacetates, carbonates, phosphonates or sulphonates; c) 0-10% by weight of a long chain aliphatic amide or of an amine oxide; d) 0-5% by weight of a cellulosic derivative, preferably the sodium salt of carboxy-methyl cellulose;; e) 10-50% by weight of a softening agent containing one at least of the following elements i) 0-50% by weight of either a quaternary ammonium cationic salt of formula [R1,R2,R3,R4N] AY wherein one at least of the R radicals is a C,6 -C22 aliphatic radical and Y designates an anionic function belonging to the group of hydroxides, halides, sulphonates or methylsulphates, or an imidazolinium salt; ii) 0-20% by weight of a tertiary amine of formula R,R2R3N wherein at least one of the R radicals designates a C10-C,8 saturated alkyl radical; iii) 0-40% by weight of a smectic clay having an ionic exchange capacity higher than 50 meq/100 grams of clay;; f) 0-15% by weight of talc or 0-10% of aluminium formate, or of calcined sodium carbonate; and g) 0-5% by weight of minor components selected among the perfuming, deodorizing, brightening, dying and/or bactericidal agents and subjecting the thus obtained mixture to extrusion and heat melting.

Extrusion and melting can be carried out in apparatus conventional in the art.

Examples of surfactants which can be employed as ingredients of the above described mixture include araliphatic alkali sulphonates, such as alkyl-benzene sulphonates having a Cg-C1n group such as those described in U.S. Patents N" 2,477,382, 2,390,295 and 3,320,174. Other examples are described in U.S. Patents N" 2,723,240, 2,712,530, 2,972,583 and in U.S. Patents N" 3,370,100 and 3,214,462.

Surfactants include also primary or secondary alkyl sulphates, e.g. of formula RO-SO3-wherein R represents a C1O-C20 alkyl group.

Among the non-ionic surfactants which can be used in the above described mixture, one might cite Pluronics (registered Trade Mark of Wyandotte Chemical Co.) formed by condensation of propylene oxide with propylene glycol. U.S. Patents No 2,674,619 and 2,677,700 describe this type of compounds. Other non-ionic surfactants are represented by Tergitol z 15-S or Neodol 45.

Amphoteric surfactants include N-lauryl-N'-carboxymethyl-N'-(2-hydroxyethyl)-ethylendiamine, alkyl-ss- alanines wherein the alkyl radicals are mixed radicals having e.g. a chain length derived from coconut oil, or betaines.

The nature of surfactants can vary to a large extent. Other examples of useful surface active agents are described by Schwartz and Perry, "Surface Active Agents" and "Surface Active Agents and Detergents", Interscience Publishers, New York, N.Y.

The ingredients defined above under letter b) represent what is commonly known in the art under the term of "builders". For example, one might mention pentasodium or pentapotassium tripolyphosphate, sodium or potassium nitriloacetate, carbonate or sulphate. Other examples of "builders" are described in U.S. Patent No 3,954,649 disclosure of which is herewith enclosed by reference. The substances are compatible with the other ingredients of the detergent mixutre and have the property of reinforcing the action thereof.

The ingredients mentioned above under letter c) represent in fact examples of lathering agents of common use in the art. For instance, one might cite the alkyl ethers of the oxides of propyl-dialkoxy amine (VAROX,Sherex Chem. Co. Inc.).

With regard to the cellulosic derivative described under letter d), its action is to prevent the redeposition of soil on fabric after the washing cycle. The sodium salt of carboxymethyl cellulose, or CMC, is an ingredient of current use. It is a commercial product known under several different denominations [see the Merck Index, 10th edition, sec. 1812 (1983)].

Quaternary ammonium cationic salts acting as ingredients in the softening agents defined under letter e), include the compounds mentioned in U.S. Patent No 3,936,537. These products are generally available on the market and one might cite as a preferred agent, AROSURFTA-100 or distearyl dimethyl ammonium chloride. Other examples of quaternary ammonium cationic salts are given in European Patent Application No 76 572.

Active softening agents include also imidazolinium salts, e.g. of formula

x = halogen R = long chain alkyl (see U.S. Patent No 3,936,537). One can also cite the sulphate salt of methyl, l-alkylamidoethyl and 2alkylimidazolinium methyl.

The tertiary amines used as active ingredients in the softening composition belong to the class of compounds including i.a.: didecyl methyl amine, dimyristyl methyl amine, dicetyl methyl amine, distearyl methyl amine, as well as the corresponding ethyl-, propyl-and butyl- amines. Other active tertiary amines are described in cited European Patent Application No 76 572. The function of these amines consists primarily to protect during the washing cycle the quaternary ammonium salts from the action of the other active constituents of the detergent mixture, viz. from that of the anionic surfactants which are present.

Optionally, the softening composition includes also smectic clay. The addition of this product to the active composition has the effect to avoid "caking" of the different components during the manufacturing process. On the other hand, it is known that clays promote a better softening effect especially when the washing process is effected in highly hard water.

In most cases, there are used to this end hydrated silicates of aluminium of montmorillonite type or Al203-4SiO2-H2O[BENTONITE 2073, The Merck Index, 10th Edition, Sec. 1051, (1983)1.

The activity of smectic clay is measured as a function of its ion exchange capacity per units expressed as milliequivalents per 100 grams of clay. Thus, the clay employed according to the invention must possess a ionic exchange capacity equal to or higher than 50 mew;100 grams.

A more detailed description of the active clays can be found in U.S. Patent No.3,936,537.

In order to facilitate the manufacture of the detergent bar according to the invention, it is possible to add to the composition different agents able to improve its consistency. For instance, one can use materials such as talc, aluminium formate as hardeners or calcined sodium carbonate to confer an abrasive property to the composition.

Finally, minor components can also be employed in the manufacture of the composition according to the invention. This includes natural or artifical perfumes, brighteners, dyes, bactericides or deodorizers.

These products can of course have a variiety of composition and their use depends on the particular nature of the end products it is desired to manufacture.

The following description gives a guideline with regard to the method followed to prepare the solid detergent bar article of the invention.

The different ingredients chosen were added to water and premixed in a soap amalgamator, e.g. of the Werner and Pfleiderer type, during approximately 15 minute". The mixture obtained was passed through a three-roll-soap-mill three times in order to obtain chips of regular size (soap mill: Weber and Seelan- der, Helmstedt i. Br., FRG). The chips obtained were thus introduced into a soap plodder (Stephane Beck, Nyon, Switzerland; mod. Br. 45 AC) operating under reduced pressure and, according to a technique cur rent in soap manufacturing, bars were formed by heating to 50-550C the chips under the effect of the pressure exerted by mechanical driving. The bars were then cut to the desired length and pressed by means of a soap press.

The following examples will illustrate the invention in a more detailed manner; it is intended however that the invention is not limited thereto.

Examples By following the procedure described above detergent- softening bars have been prepared by mixing the following ingredients (parts by weight): Ex:1 2 3 Sodium salt of lauryl sulphate TEXAPON Z (Henkel) 35 35 35 Monoethanolamide of fatty acids derived from cocnut oil COMPERLAN 100 (Henkel) 3 3 3 Sodium tripolyphosphate 15 15 15 Polyethyleneglycol, PEG 4000 (Hoechst) 6 6 6 Stearin 6 6 6 Sodium sulphate 4.8 9.8 8.7 Talc 5 5 5 Bentonite 2073 (Whittaker & Clare)2) 8 5 TIXOGEL (stud Chemise)1 - - 4 Dimethyl distearyl ammonium chloride2 4 - 4 Calcined sodium carbonate 2 2 2 Water 9.9 11.9 10 Aluminium triformate crystallized (GS 5003;Zschimmer & Schwarz) 1 1 1 Perfume (Firmenich SA)a 0.3 0.3 0.3 1) quaternary ammonium derivative of smectic clay (montmorillonite) 2) smectic clay 3) AROSURF TA-100 4) Several perfume compositions have been used. Particularly, Padmini 618.108, Herbania 41.394, Lotus 77.055, Herbania 41.394/L, Roceline 41.484, Roceline 41.484/B (origin Firmenich SA). Of couse, these compositions can be replaced by specific compounds. The nature of the perfume composition has no effect on the detergent-softening property of the obtained articles.

The detergent-softening bars thus obtained have been subjected to an evaluation by a panel constituted by 15 to 20 persons who were requested to express an opinion on the performance achieved by the bars with respect to their softening properties on fabrics.

To this end, the following procedure was followed. A strip of standard cloth consisting of a cotton made towel was put into warm water (ca. 500C), then it was soaped on both its sides by means of the detergent-softening bar under examination. This operation was followed by rinsing it with water at about 35"C, whereupon the strip was once again soaped in a manner identical to the one applied before. After rinsing with water at 35"C, the strip was wrung dry by hand, then it was left to dry at room temperature in a normally ventilated room.

The panel had then to express its view by "blind test" on the quality of the wet cloth strip with regard to its properties of softness and its antistatic character by comparison with a cloth treated in an identical fashion by applying however a detergent non-softening bar of the commerce. The comparative evaluation was repeated on the cloth after drying (one night at room temperature).

The following table summarizes the results obtained.

preference factor[ /O] Example 1 wet cloth 97 dry ooth 100 Example 2 wet cloth 90 dry cloth 90 wet cloth 91 dry cloth 93 The detergent-softening bars prepared according to the invention were also subjected to an evaluation to assess their performance regarding their detergent properties. To this end, 1 gram of product in 500 ml of washing water was utilized. Program : 20-40"C (Linitest). The cloth samples subjected to washing were provided by the Swiss Federal Laboratories for Materials Testing and Research (EMPA, St-Gallen/ Switzerland) : article n 103, series 37.

It could thus be determined that the detergent properties of the bars according to the invention were similar and in some instances even superior to those of a normal commercial detergent bar.

Claims (3)

1. Solid detergent bar article having a softening action on the fabrics subjected to washing, which comprises the following active ingredients a) 1-50% by weight of a surfactant belonging to the group of anionic, nonionic, amphoteric, cationic or zwitterionic surfactants or mixtures thereof; b) 1-50% by weight of an organic or inorganic alkali salt belonging to a group of tripolyphosphates, nitrilotriacetates, carbonates, phosphonates or sulphates; c) 0-10% by weight of a long chain aliphatic amide or of an amine oxide; d) 0-5% by weight of a cellulosic derivative, preferably the sodium salt of carboxy-methyl cellulose; e) 10-50% by weight of a softening agent containing one at least of the following elements i) 0-50% by weight of either a quaternary ammonium cationic salt of formula [R1,R2,R3,R4N]+Y - wherein one at least of the R radicals is a C,6- C22 aliphatic radical and Y designates an anionic function belonging to the group of hydroxides, halides, sulphates or methyl-sulphates, or an imidazolinium salt; ii) 0-20% by weight of a tertiary amine of formula R,R2R3N wherein at least one of the R radicals designates a C,,-C,, saturated alkyl radical; iii) 0-40% by weight of a smectic clay having an ionic exchange capacity higher than 50 meg/100 grams of clay; f) 0-15% by weight of talc or 0-100io of aluminium formate, or of calcined sodium carbonate; and g) 0-5% by weight of minor components selected among the perfuming, deodorizing, brightening, dying andlor bactericidal agents.

2. Process for the preparation of an article according to claim 1, which comprises the following consecutive steps: a) mixing the active ingredients with water in a concentration of 5-15 parts by weight of water per 100 parts of the resulting mixture; b) reducing the said mixture into chips and c) subjecting the resulting chips to an extrusion at about 50-55"C at atmospheric or sub-atmospheric pressure.

3. A detergent-softening composition which contains the following active ingredients a) 1-50% by weight of a surfactant belonging to the group of anionic, nonionic, amphoteric, cationic or zwitterionic surfactants or mixtures thereof; b) 1-50% by weight of an organic or inorganic alkali salt belonging to a group of tripolyphosphates, nitrilotriacetates, carbonates, phosphonates or sulphates; c) 0-10% by weight of a long chain aliphatic amide or of an amine oxide; d) 0-5% by weight of a cellulosic derivative, preferably the sodium salt of carboxy-methyl cellulose;; e) 10-50% by weight of a softening agent containing one at least of the following elements i) 0-50% by weight of either a quaternary ammonium cationic salt of formula [R,,R2,R2,R4N] Y wherein one at least of the R radicals is a C,6 C22 aliphatic radical and Y designates an anionic function belonging to the group of hydroxides, halides, sulphates or methyl-sulphates, or an imidazolinium salt; ii) 0-20% by weight of a tertiary amine of formula R1R2R3N wherein at least one of the R radicals designates a C,0-C,8 saturated alkyl radical; iii) 0-40% by weight of a smectic clay having an ionic exchange capacity higher than 50 meq/100 grams of clay; f) 0-15% by weight of talc or 0-10% of aluminium formate, or of calcined sodium carbonate; ; and g) 0-5% by weight of minor components selected among the perfuming, deodorizing, brightening, dying and/or bactericidal agents.