US 3044962 A
Description (OCR text may contain errors)
United States Patent 3,044,962 PREPARATION OF DETERGENT COMPOSITIONS Kenneth Arthur Brunt, Croesyceiliog, Cwmbran, and
David Williams, New Inn, Pontypool, England, assignors to British Nylon Spinners Limited, Pontypool, England No Drawing. Filed Oct. 21, 1958, Ser. No. 768,549 Claims priority, application Great Britain Oct. 31, 1957 7 Claims. (Cl. 252--110) This invention relates to detergents for textiles, notably those consisting of synthetic linear polymers, and in particular to such detergents which also exercise an antistatic effect.
It is well known that synthetic linear polymer textile material, e.g. polyamide textile material, is liable to become electrostatically charged as a result of adventitious friction in the course of use, for example, friction arising from movements on the part of the wearer of the textile material concerned. There is, moreover, evidence to the effect that the soiling during wear of, for instance, a nylon shirt (nylon being polyhexamethylene adipamide) may be due in considerable measure to the electrostatic attraction of particles of dirt. Efforts have accordingly been made to devise anti-static agents capable of hindering the accumulation of such electric charges. These anti-static agents, though they may be effective when applied, are, however, frequently insufficiently resistant to rinsing.
The ingredient of the present detergents responsible (or mainly responsible) for their detergency is an anionic surface active agent, i.e. a water-soluble compound, having lipophilic and hydrophilic groups in the anion (of. pages 108 and 109 of Surface Active Agents," by C. B. F. Young and K. W. Carns, 1945, Chemical Publishing Co. Inc.), a genus which includes, inter alia, the alkali soaps, e.g. sodium stearate (a constituent of common soap), alkali metal fatty alcohol sulphates, e.g. sodium cetyl sulphate, alkylarly sulphonates, e.g. sodium p-dodecylbenzene sulphonate and alkyl monoglyceryl phosphates or sulphates, e.g. dodecyl octyl monoglyceryl phosphate.
The present detergents also contain a convertional water-soluble inorganic salt of neutral or alkaline reaction, e.g. sodium carbonate, sodium sulphate, sodium borate. Now it has been found that by incorporating a minor proportion of a cationic surface active agent, that is, a water-soluble compound having lipophilic and hydrophilic groups in the cation (loc. cit.), such as trimethyl-octadecyl-ammonium chloride, an anti-static effect may be imparted. Normally anionic and cationic surface active agents undergo mutual precipitation when mixed in solution. Surprisingly, however, experiments have shown, that provided the cationic agent is first mixed with sufficient of an inorganic salt powder, before the incorporation of the anionic agent, the aforesaid precipitation can be avoided. It is preferred that the cationic agent be applied in the form of a solution, to a sufficiency of the solid inorganic salt, so as to coat the individual crystals or granules thereof without making the powder, as a whole, wet. Mixtures so obtained can be safely mixed with the desired anionic surface active agent without fear of precipitation occurring when the resulting detergent mixture is dissolved in water for use in washing. Moreover, the anti-static effect produced ICC by the employment of the present detergents withstands rinsing and tends even to increase during the course of successive washings. The present detergents also appear to have the advantage of hindering re-deposition of the dirt on the fabric whilst it is in the wash liquor. Although the numerical data quoted in the following examples only relate to the electrostatic charges, extensive trials involving the wearing and washing of garments, wherein the present detergents are compared with similar detergents devoid of the cationic agents, show the superiority of the former.
Accordingly the present invention relates to a process for making detergents comprising mixing an alcoholic, aqueous or aqueous-alcoholic solution of a cationic surface active agent, 7111011 15 a quaternary ammonium, phosphromum or l'l'lOlPhOlll'llllIl'l salt, with a sufficient quantity of a powdered water-sofible alkaline-reagting or neutral-reacting inorganic salt, so that the weight of fiid salt remaimng undrssolved 1s not less than themeight of tlia cationic surface active agent, d yfiggll fii fiifl to remove any visible liquid, and then intimatelv mixing face active agefirearpid eaf Whendrying'is'elfectedin order to remove any visible liquid, the dried product is advantageously powdered so as to facilitate the subsequent mixing with the anionic surface active agent. It is however preferred that the qnantity of the solution of the cationic surface active agent employed should only suffice to coat the individual crystals or granules of the inorganic salt powder, without making the latter visibly wet. In this case there is thus no visible liquid present and therefore no drying is required. The anionic surface active agent may be introduced either as the pure compound or, for example, in the form of an aqueous solution or paste, or otherwise conveniently diluted.
An anti-static effect is produced even when the proportion of cationic surface active agent to anionic surface active agent is as low as 1-500 or even 1-1000. However, it is preferred that the weight of the anionic agent be from 10 to 200 times the weight of the cationic agent.
The cationic surface active agent may be for example:
Octadecyl-trimethylammonium chloride Octadecenyl-trimethylammonium chloride Octadecadienyl-trimethylammonium chloride Dodecyl-trimethylammonium chloride Hexadecyl-trimethylammonium chloride Didodecyl-dimethylammonium bromide Dioctadecyl-dimethylarnmonium chloride Benzyl tri-(dimethylamino) phosphonium chloride Benzyl-stearyl-dimethylammonium chloride Hexadecyl methyl morpholinium methosulphate Hexadecyl pyridinium chloride Dodecyl pyridinium chloride Those cationic surface active agents are preferred which are capable of imparting a strong antistatic effect when applied to the textile material by themselves.
Examples of the inorganic salt to be employed are:
Anhydrous sodium carbonate Sodium carbonate decahydrate Sodium bicarbonate Sodium borate Sodium sulphate 3 Trisodium orthophosphate Sodium metaphosphate Sodium pyrophosphate Disodium hydrogen phosphate Sodium tripolyphosphate Sodium perborate The anionic surface active agent may be, for example:
Sodium cetyl sulphat Sodium oleyl sulphate Sodium dodecyl sulphate Sodium p-dodecylbenzene sulphonate Triethanolaminonium p-dodecylbenzene sulphonate Sodium stearate Sodium oleate Sodium isopropyl naphthalene sulphonate Oleyl methyl taurine Sodium dioctyl monosulphosuccinate Mixtures of such inorganic salts, as above, may be used. Other conventional ingredients may optionally be included in the present detergents, such as, for instance, china clay, sodium silicate, magnesium silicate.
The following examples, in which the parts are by weight are intended to illustrate, but not limit the present invention.
Example 1 9.85 parts of a 75% solution of dioctadecyl-dimethylammonium chloride in iso-propanol are diluted with 6 of methanol and thoroughly mixed with 12 parts of anhydrous sodium carbonate powder. The resulting powder is then mixed with 50 parts of common soap powder.
A plain weave fabric of 30 denier nylon yarn (10 filaments) is washed repeatedly and examined as to its tendency to become electrostatically charged in the following manner:
The fabric, divided into 11 strips, is immersed and agitated for 3 minutes, in 100 times its own weight of a 0.1% aqueous solution of the above detergent at 60 C. The fabric strips are then removed, rinsed once with warm water and twice with cold water, and dried. One strip is set aside and the remaining ten washed again, rinsed and dried as before. Another strip is set aside and the process repeated until the final strip has received 11 washes.
The strips of fabric are stored for 24 hours in an atmosphere of 65% relative humidity at 70 F. together with 10 strips of the same fabric which have not been washed. Each strip measuring 3" x 2" is then tested as follows. The fabric placed on filter paper is brushed 3 times with a nylon brush and put into the inner container of a Faraday ice pail. The charge produced, in a circuit of constant capacity, is read in terms of voltage from a Rothschild Electrostatic Voltemeter (obtainable from Messrs. Rothschild of Wafienplatz, Zurich), the following results being obtained:
No.0fwashes--. 1 2 3 4 5 6 7 8 9 10 Volts (negative). 200 250 30 45 Unwashed fabric (mean of 10 tests): 300 volts.
Example 2 detergent and tested in the way described in Example 1. The following results being obtained:
No. of washes- 1 2 3 4 5 6 Volts (negative) 250 330 Unwashed fabric (mean of 10 tests): 420 volts.
Example 3 20 parts of sodium p-dodecyl benzene sulphonate 40 parts of sodium tripolyphosphate 40 parts of sodium sulphate The resultant mixture constitutes the detergent; the ratio by weight of anionic to cationic agent contained therein is 2:1.
Strips of nylon fabric are washed with times their weight of a 0.1% aqueous solution of the above detergent at 60 C. and the electrostatic charge produced measured as described in Example 1. It is found that the charge is only about 15 of that generated on the unwashed fabric.
Example 4 Example 3 is repeated except that only 2 parts of the 50% solution of cationic agent are taken. The electrostatic charge is 30% of that found on the unwashed fabric.
Even when only 0.2 part of the 50% solution of cationic agent is employed, the electrostatic charge is much less than that produced on the unwashed fabric.
Similar results are obtained when the fabric is made of cellulose acetate, cellulose triacetate or polyethylene terephthalate, instead of nylon.
What we claim is:
1. A process for the manufacture of a detergent composition comprising mixing an alcoholic solution of a cationic surface active agent, selected from the group consisting of quaternary ammonium, phosphonium and morpholinium salt, with a sufiicient quantity of a powdered sodium salt selected from the group consisting of anhydrous sodium carbonate, sodium carbonate decahydrate, sodium bicarbonate, sodium borate, sodium sulphate, trisodium orthophosphate, sodium metaphosphate, sodium pyrophosphate, disodium hydrogen phosphate, sodium tripolyphosphate and sodium perborate, so that the weight of said salt remaining undissolved is not less than the weight of the cationic surface active agent, drying if necessary to remove any visible liquid, and then intimately mixing with a quantity of a synthetic organic anionic surface active agent weighing from 2 to 1000 times the weight of the cationic surface active agent employed.
2. The process of claim 1, wherein the quantity of the solution of the cationic surface active agent only suffices to coat the individual particles of the powdered sodium salt, without making the latter visibly wet, so that no drying is required.
3. The process of claim surface active agent is from of the cationic agent.
1 wherein the weight of anionic 10 to 200 times the weight References Cited in the file of this patent UNITED STATES PATENTS Malkemus Dec. 20, 1949 Hibbs Feb. 13, 1951 l- Anderson Mar. 15, 1960 1 m FOREIGN PATENTS Canada Jan. 3, 1956 u' r OTHER REFERENCES McCutcheon: Soap and Sanitary Chemicals, July 1952, pp. 48-50.