US 3914496 A
Antistatic finishing of surfaces of shaped articles, especially textiles, which tend to acquire an electrostatic charge, using quaternary ammonium compounds which contain 2 to 4 hydroxyethyl groups per ammonium group.
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Description (OCR text may contain errors)
United States Patent [191 Jorek et al.
[451 Oct. 21, 1975' ANTISTATIC FINISHING OF SURFACES Inventors: Helmut Jorek; Rolf Fikentscher,
both of Ludwigshafen; Joachim Kur ze, Leutershausen, all of Germany; Herbert Helfert, Trenton,
Mich. Assignee: Bast Aktiengesellschaft,
Ludwigshafen (Rhine), Germany Filed: Mar. 1, 1974 Appl. No.: 447,228
Foreign Application Priority Data Mar. 1,1973 Germany .......2310186  References Cited UNITED STATES PATENTS 2,096,749 10/1937 Kritchevsky 117/1395 F 2,205,042 6/1940 Lenher 61 a1 117/1395 F 3,065,110 11/1962 Hagge e161. 117/1388 UA 3,174,985 3/19 5 Berger 117/138.8 N 8/1972 R6111 117/1395 CQ Primary Examiner-Michael R. Lusignan Attorney, Agent, or Firm-Johnston, Keil, Thompson and Shurtleff  ABSTRACT Antistatic finishing of surfaces of shaped articles, especially textiles, which tend to acquire an electrostatic charge, using quaternary ammonium compounds which contain 2 to 4 hydroxyethyl groups per ammonium group.
'2-Claims, No Drawings ANTISTATIC FINISHING OF SURFACES This invention relates to the antistatic finishing of surfaces of shaped articles, especially textiles, which tend to acquire an electrostatic charge, using quaternary ammonium compounds which contain 2 to 4 hydroxyethyl groups per ammonium group.
It is known that many articles consisting of macromolecular materials tend to build up an objectionable electrostatic charge during processing or in use. This tendency is particularly common with articles of synthetic macromolecular materials; however, it is not restricted to these but also occurs with fibers of cellulose esters and even fibers of cellulose, regenerated cellulose, silk, wool and other vegetable and animal products, when the moisture content of these fibers which is primarily determined by the relative atmospheric humidity falls below a certain limit. This limit differs from one type of fiber to another.
Numerous chemical compounds have already been proposed as antistatic agents. The conventional antistaticagents are mostly longchain alkyl oraralkyl compounds of the non-ionic, anionic or cationic type. Amongst these, the cationic fatty alkyl compounds of nitrogen or phosphorus, in the form of their tertiary or quaternary salts, are preferred because by virtue of their substantivity and their orientability on the surface of the fiber they produce very good antistatic effects. The orientation of the molecules of these surfaceactive positively charged compounds is attributable to their chemical structure which is characterized by a long hydrophobic alkyl radical of 8 to carbon atoms and a hydrophilic salt-forming group. A cycloaliphatic or aromatic radical can take the place of the longchain alkyl radical, but, evidently for steric reasons, these products are less effective antistatic agents than the aliphatic compounds.
The disadvantage of these compounds is that they are strongly cationic, hence react both with anionic surfactants and with anionic dyes to form sparingly soluble salts, and therefore cannot be used conjointly with such surfactants or dyes.
Compounds which act as antistatic agents and, in spite of their pronounced positive charge, do not react as cationic compounds have been disclosed in the literature. These are substituted urea derivatives which, however, suffer from the disadvantage when used on textiles that the substrate finished with them can develop an unpleasant fishy odor on storage under adverse conditions. I
It is an object of the present invention to provide a process for antistatic finishing, especially of textiles, which is at least as good as the conventional processes in respect of antistatic activity but does not suffer from the disadvantages described.
We have found a process for antistatic finishing of surfaces of shaped articleswhich tend to build up an electrostatic charge, by coating with ammonium salts, wherein the coating agents used are ammonium salts of the formula Q-I ((:H. cH, oH)z x6 where X is a monovalent organic or inorganic anion or the n-th part of an n-valent anion of a water-soluble acid, (i.e., one equivalent of an anion of a water-soluble acid) R and Q independently of one another are each hydroxyalkyl of 2 or 3 carbon atoms, alkyl of l to 6 carbon atoms or benzyl and Q can also be the radical in which A is alkylene of 2 to 6 carbon atoms. Compounds of the said formula in which R is hydroxyethyl and Q is methyl or ethyl are preferred.
The compounds can be obtained conventionally-by reaction of appropriately substituted diethanolamines or of triethanolamine with alkylating, hydroxyalkylating or benzylating agents, such as dialkyl sulfates, alkyl 7 halides or alkyl dihalides, toluenesulfonic acid alkyl esters, benzyl chloride or ethylene oxide or propylene oxide together with acids, in equimolar ratios. The quaternization reactions take place at temperatures of 20 to C though with some sluggish quaternizing agents temperatures of up to C are required. Solvents can be used for example for the purposeof cooling the mixture through boiling of the solvent.
As the anion X it is possible to use more or less any watersoluble organic or inorganic acid radicals. For economic reasons, the anions of industrially available acids, for example of sulfuric acid, hydrochloric acid, hydrobromic acid, toluenesulfonic acid and methylsulfuric acid are preferred.
Compounds with fewer than two 2-hydroxyethyl groups on the quaternary nitrogen are not sufficiently active antistatically.
The compounds, and their manufacture, are not claimed herein.
In contrast to the quaternary ammonium compounds conventionally used for this purpose, the compounds of the formula shown exhibit an antistatic action, even at low relative atmospheric humidities, to a hitherto unknown degree. They are therefore particularly suitable for the antistatic finishing of fibrous textile materials of all kinds, for example fibers, filaments, tops, card slivers, yarns, non-woven fabrics, felts, woven fabrics and knitted fabrics, consisting of synthetic high molecular materials, such as'linear polyesters, polyamides, acrylonitrile polymers, p'olyolefins and polyvinyl compounds, or consisting of natural high molecular weight materials or their derivatives, such as cellulose, regenerated cellulose, cellulose esters, silk, wool and other vegetable and animal materials.
The antistatic effect of the compounds persists for a prolonged period even at high temperatures; textile materials finished with these compounds do not yellow, because of the high heat stability of the compounds. In spite of their pronounced positive charge the compounds do not behave as cationic compounds, that is to say they react neither with anionic surfactant nor with anionic dyes to form precipitates, so that they are universally applicable without the hazard of the difficulties which arise, when using the conventional cationic antistatic compounds, during subsequent finishing processes such as dyeing, wash-and wear finishing and hydrophobic treatments. Their particular advantage is that even on storing the finished textiles under adverse conditions a fishy odor does not develop.
In addition, these antistatic agents have further advantages in use over the fatty alkyl-ammonium salts.
They give completely clear colorless solutions in water even at room temperature. The viscosity of these solutions is low even at concentrations of 50 to 80 per cent by weight of the compounds, so that they can be 4 nation products of natural fats of animal or vegetable origin, oxyalkylation products of fatty acids, sulfonate salts of alkylated aromatics, sulfuric acid ester salts of fatty alcohols and of partial fatty acid esters of polyhydsprayed at high concentrations. As a result of the ab- 5 ric alcohols, salts of partial phosphoric acid esters, and sence of long alkyl radicals, the compoundsdo not afdispersions of polyethylene and other vinyl comfeet the handle or appearance of the fibrous materials pounds, such as copolymers of butyl acrylate, quatertreated therewith and do not increase the soiling tennary vinylimidazole and methylolacrylamide.
dency, in the sense of mechanical adhesion of dirt par- Apart from the treatment of fibrous materials, the ticles to the surface of the fibers. For these reasons, the compounds of the above formula have proved outcompounds are particularly suitable for the antistatic standingly successful in the antistatic surface treatment treatment of textiles which suffer heavy soiling from of non-fibrous articles of any materials which tend to dust, for example net curtains, carpets, furnishing fabbuild up an electrostatic charge, especially of materials rics and industrial fabrics, such as dust filters, conveyor usually referred to as plastics or resins. Here again, belts and drive belts which in most cases are not subaqueous solutions are suitable and these can again be jected to intensive wet washing. In addition, the abapplied by dipping or spraying, but can also be spread sence of a long alkyl radical and hence the absence of by rubbing the surface to be protected with an imprega fatty character has the advantage that the crocking nated cloth. In this way it is possible to provide, for exfastness of dyeings produced with disperse dyes and aftample, films, phonograph records, lighting appliances, ertreated with the compounds of the above formula is refrigerators, radio cabinets and plastics-veneered furnot adversely affected even in the case of deep shades. niture'with antistatic surface protection.
It is very simple to use the compounds of the above Tables 1 and 2 show the antistatic action of the comformula for the antistatic treatment of fibrous materipounds on textile material. The data are determined as als. The treatment is suitably carried out with aqueous follows: solutions which are applied to the material to be 5 g of continuous filament of polycaprolactam (dtex treated by any desired method, for example by dipping 67 f 12 Z) or polyethylene terephthalate (dtex 75 f 24) or spraying, after which the material is dried. The appliare wound up on a winch of 120 cm circumference. cation of 0.03 to 2 per cent by weight of the com- This material is treated depending on the example pounds of the above formula to the fibrous material to with 0 g/l, 0.5 g/l, 1 g/] or 2 g/l of antistatic agent at pH be provided with antistatic protection has proved ap- 5 to 6 for 15 minutes at C, using a liquor ratio of propriate. The fibrous material can be provided with 30:1. The material is then centrifuged until the wet pick the antistatic finish at any desired point in the course of up is per cent, and is dried at C. Because of the its processing, or after it has been finished in other reabsence of any substantivity, the amount applied to the spects, or even during use. It is also possible, and frefiber corresponds to that calculated.
quently advantageous, to combine the antistatic finish- 35 The hank is wrapped with a strong thread at one end ing operation with other conventional treatment of the and is cut open at the other end. After conditioning, the fibrous material, by treating the fibrous material with hank is repeatedly drawn through a brass die of 4.5 mm solutions of the compounds of the above formula which diameter until the charge has reached a maximum, and also contain, for example, softeners, lubricants, brightis then held in a brass half-cylinder of 80 mm diameter eners, smoothing agents or wetting agents. Examples of 40 and 500 mm length, connected to an electrostatic voltsuch known agents are quaternary fatty alkylage meter (Static-voltmeter supplied by Rothschild, ammonium or fatty alkyl-sulfonium compounds, fatty Switzerland). The potential is read off in volts. acid esters, fatty acid alkylamides, tertiary or quater- The hanks are heat-treated in a through-circulation nary fatty acid amide-amines, fatty alkyl sulfates, sulfodryer.
TABLE 1 Product Electrostatic charge of polycaprolactam hanks in volts at 20C and 65% relative atmospheric humidity Reaction product of Hank before heat Hank stored 5 minutes at code exposure 180C treated with g/l of treated with gll of active substance active substance 1 mole of quaterniz- 1 mole of amine 0 0.5 1.0 0 1.0 2.0 ing agent (untreated) (untreated) Examples A Dimethyl Tris-( Z-hydroxy- +1 ,300 0 0 +1 ,000 0 O accordsulfate ethyl)-amine ing to 8 Methyl chloride 0 0 +50 0 o the invention C 2-Chloroethanol +50 0 0 0 D Benzyl chloride 0 +100 0 E p-Toluenesulfonic +200 0 +100 0 acid methyl ester F 0.5 mole of 1,4- +50 0 +50 0 dichlorobutane G .Dimethyl sulfate N-Methyl-bis-(Z- hydroxyethyl)- +50 0 0 0 amine H Methyl chloride +50 0 +100 0 K Dimethyl sulfate N-(n-Buty1)-bis- +200 0 +100 0 (2-hydroxyethyl)- amine L Methyl chloride +200 0 +200 0 Com- 1 Dimethyl N-Dimethyl-(Z-hyparisulfate droxyethyU'amine +1,300 +1.100 +1,000 +1.000 +1,100 +1 ,000
TABLE -1 -continued Electrostatic charge of polycaprolactam hanks in volts at 20C and 65% relative atmospheric humidity Product Reaction product of: Hank before heat Hank stored minutes at code exposure 180C treated with g/l of treated'iwith g/l of v active substance active substance 1 mole of quatemiz- 1 mole of amine} 0 0.5 L0 0 1.0 2.0 I ing agent (untreated) (untreated) son ll 7 Methyl +1 ,200 +l,000 .+l.100 800 exchloride 1 amples lll p-Toluenesulv fonic acid H.300 H.100 +1.000 +1,000 methyl ester lV Dimethyl N-Diethyl-(Z-hy- +1 ,200 +1.100 900 700 sulfate droxyethyl)-amine V Methyl +1,000 +1.100 +l,l00 900 chloride V1 Dimethyl N-Di-n-butyl-(2- sulfate hydroxyethyl)-amine +1.300 +1 ,000 +l,100 +1.000 Vll Dimethyl Tris-(2-hydroxyiso- +1.300 +l,100 +1,000 +1 ,000
sulfate propyl)-amine Vlll Methyl +1,300 +1,300 900 +1.000
chloride lX p-Toluene- +1,400 +l,100 +l,l00 +1.100
sulfonic acid methyl ester TABLE 2 Electrostatic charge of PBS hanks in volts at C and 65% relative atmospheric humidity Product Reaction product of Hank before heat Hank stored 5 minutes code exposure at 200C treated with gll of treated with g/l of active substance active substance 1 mole of quaterniz- 1 mole of amine 0 0.5 1.0 0 1.0 2.0 ing agent (untreated) (untreated) Examples A Dimethyl Tris-( 2-hydroxy- +300 0 0 -l ,000 0 0 according sulfate ethy1)-amine w to the 8 Methyl chloride 0 0 0 0' invention E p-Toluenesul- +50 0 50 0 fonic acid methyl ester G Dimethyl N-Methyl-bis-(Z- 0 O 0 0 sulfate hydroxyethyl)- amine K Dimethyl N-(n-Butyl)-bis- +50 0 100 O sulfate (Z-hydroxyethyl amine Com- 1 Dimethyl sulfate N-Dimethyl-(Z- +300 +200 +100 1,000 500 -600 parison hydroxyethyl)- examples amine ll Methyl chloride +200 +200 800 200 Vll Dimethyl sulfate Tris-( 2-hydroxy- +200 +200 -700 -600 isopropyl)-amine Vlll Methyl chloride +300 +300 -800 300 1X p-Toluene- +350 +200 -1,000 800 sulfonic acid methyl ester EXAMPLE 1 A polyamide-6 knitted fabric is treated on a dyebeck using a dilute liquor (liquor ratio :1), with an 0.05% strength solution of N-methy1-tri-( 2-hydroxyethyl)- ammonium chloride at pH 6 and approximately 40C for 10 minutes. After centrifuging to about 30% resid ual moisture content, and drying, the fabric is thermoset at 180 to 200C. A polyamide material treated in this way does not build up any electrostatic charge during subsequent processing, such as lapping and makingup, or during use.
EXAMPLE 2 The surface of a polystyrene molding is sprayed with a 1% strength aqueous solution of N-dimethyl-bis-(Z- hydroxyethyl)-methosulfate which contains 0.05% of sodium hexylheptylnaphthalenesulfonate to give better wettability. After drying, the molding is antistatic; it
, shows no tendency to build up an electrostatic charge when rubbed and therefore does not attract dust from the atmosphere.
EXAMPLE 3 3 ,9] 4,496 7 8 material, of at least one ammonium salt of the formula [A9(CH,CH,OH), :l x6
Q Q N(CH CH 'OH) Xe A is alkylene of 2 to 6 carbon atoms and R is hydroxyalkyl of 2 or 3 carbon atoms, alkyl of l to 6 carbon atoms or benzyl.
2. A fibrous material as set forth in claim I wherein l0 said fibrous materials are prepared from polyesters, where X IS. one equivalent of an anion of a water-solu- I polyamides, acrylonitme polymers, polyolefins or y ble acid, 0 IS hydroxyalkyl of 2 or 3 carbon atoms, alkyl vinyl compounds of l to 6 carbon atoms, benzyl or the radical