US 3912841 A
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United States Patent [191 Payne et al.
[451 Oct. 14, 1975 SYNTHETIC BULK FABRIC TREATED WITH ORGANICALLY MODIFIED SiO AQUASOL  Inventors: Charles C. Payne, Chicago; Richard E. Bloemke, River Grove; David P. Schaefer, l-linsdale, all of 111.
 Assignee: Nalco Chemical Company, Oak
 Filed: Oct. 31, 1973  Appl. No.: 411,582
 US. Cl. 428/96; 427/427; 428/241;
428/331  Int. Cl. B32B 3/02; B32B 5/16; 3328 33/00  Field of Search 1l7/139.5 CF, 138.8 N,
 References Cited UNITED STATES PATENTS 2/1956 Rainard et al. 1 17/1395 CF 2/1956 Florio et al. 117/139.5 CF
2,877,142 3/1956 Rusher et a1 117/169 R 2,928,754 3/1960 Schappel ll7/139.5 CF 2,999,774 9/1961 Schappel 117/139.5 CF
Primary ExaminerRalph Husack Assistant ExaminerSadie L. Childs Attorney, Agent, or FirmJohn G. Premo; John S. Roberts [5 7 ABSTRACT 5 Claims, 1 Drawing Figure PRODUCT A AS AN ANTISTAT HALF LlFE TIME, SECONDS .h
NYLON CLOTH v SiO SOLUTION USED PRODUCT A AS AN ANTISTAT NYLON CLOTH HALF LIFE TIME, SECONDS I I L0 2.0 3.0 4.0 5.0 6.0 7.0
%'SIO SOLUTION USED SYNTHETIC BULK FABRIC TREATED WITH ORGANICALLY MODIFIED SIO AQUASOL The present invention is concerned with the utilization of a modified aquasol on pile fabric of carpets and It is preferred that the starting aqueous silica sols used in this procedure be double deionized by any of the well-known techniques. If the sol is not double deionized, it will benecessary to dilute the starting aque- Na O, percent ous silica sol to a roximatel 35% silica. on other soft material and this application contains sub- 5 pp y ject matter related to Peter H. Vossos, Ser. No. A preferred starting silica sol for purposes of the 373,217, filed June 25, 1973. The modified aquasol is present invention is that denoted as Nalcoag 1034A, a coated with a double layer of a quaternary ammonium double deionized sol, containing 34% colloidal silica TABLE I Nalcoag 1030 1034A I035v 1050 1060 1130 1140 Percent colloidal silica, as Si0 30 34 35 l 50 50 30 40 r 10.2 3.1 8.6 9.0 8.5 10 Average particle'size, millimicrons I 1 1-16 16-22 16-22 17-25 40-60 8 Average surface area, M lgram 190-270 135-190 135-190 120-176 50-75 375 200 Specificgravity at 68F 1.205 1.230 1.255 1.385 1.390 1.214 L296 Viscosity at 77F,c.p.s. 5* 5* 5 70* 5-10 7 8 0.40 006* 0.10 0.30 0.10 0.65 0.40
Less than salt or hydroxide. The pertinent prior patent art is noted below and deals with related compounds and methods of treating textiles wherein the treating agent is an organosol modified with a quaternary ammonium compound: i
US. Pat. No
US. Pat.No US. Pat. No
' Uf SfPat. No."3, 033,699 Aarons et al. (duPont) is.
specially of ihte restwith' respect to pile fabric and carpets by treatment with combination of silica andclay which fun'ctions 'asa combined antistatic and antisoil treatment. i i p L In the literature E. Matijevic, Surface and Colloid Scie r'lce, Volume 6, John Wiley and Sons, 1973, pages 74, 84-86, teaches the effect of adding organic bases to aqueous silica sol and'the resultant antisoil and antistatic' or conductive properties added there to.
Additionally, R. K. Iler, The Colloid Chemistry of Silicd'dnd silicates, Cornell Press, 1955 pages 100-1 12, relates to the types and effectsof counter-ion concentration of additives to reverse the charge on the silica.
1n the present descriptionthe terrri fsoft materials" embraces fabrics consisting of carpets, wall coverings, dr'aperies,car interiors, etc.
'THESTARTING AQUEOUS SILICA SOLS Generally, any aqueous silica sol can be used for this invention These arewell known to the art. The starting aqueous silica' sol carfrangeffrom 10 to 60 percent by weight of discrete, dense colloidal particles of amorphous silica; The average particle diameter can range from 3 to 150 millimicrons and can have an average surface area from 20 M /g. to 1,000 M /g. It is preferred that the starting aqueous silica sol be from 30 to percent by weight of discrete, dense colloidal particles of amorphous silica. The preferred particle diameter should range from 16 to 22 millimicrons and have an average surface areafrom l35 to 190 M /g,
The following is, atable of commercially available calculated as SiO Typically Nalcoag 1034A contains less than 600 ppm of sodium, Na, calculated i as Na O, and ppm of chloride, Cl, as combined chloride and sulfate.
In utilizing commercial silica sols, effort was made to start with a relative concentration of SiO :Na O of greater than about 200/1.
THE QUATERNARY AMMONIUM COATING .The quaternary ammonium compound has the formula:
wherein R R are methyl R is methyl or a C,,-C long hydrocarbon chain; R is a C,;--C long hydrocarbon chain; Xis an anion selected from the group consisting of chloride, bromide, iodide, and hydroxide. Another quaternary ammonium compou nd that has In the formulae above the nitrogen substituent groups are chosen with the viewpoint of providing water solubility or having some degree of water dispersibility provided by 2 or 3 methyl coupled with 1 or 2 long hydrocarbon chain groups to provide the necessaryfat'ty residue for the coating. Thus, operable compounds are those where R, or R R, are lauryl, plamityl, stearyl, oleyl, octyl, caprylyl, etc., and these may be similar or dissimilar. Preferred substituents for R and R are quaternary amines derived from mixtures of fatty acids that occur in various fats and oils such as coconut oil, hydrogenated tallow, hydrogenated castor oil, etc. Specific examples of preferred quaternary compounds include:
Lauryl trimethyl ammonium chloride Dicocodimethyl ammonium chloride .Di(hydr'ogenated tallow) dimethyl ammonium chloride Tallow trimethyl ammonium chloride An additional operable compound not consonant with the formulae supra, is tricaprylmethyl ammonium chloride. Additionally operable are the alkyl trimethyl amthe outward'nitrogen, which is part of the second coating of quaternary. 7
SOLVENT The starting silica aquasols are preferably double deionized sols, and it has been found highly advantageous to add a hydrophilic bridging solvent such as a lower alkanol and a preferred alkanol is isopropanol. The
amount of isopropanol utilized is preferably about 3 l% by weight of the water in the aquasol. The lower alkanol, e.g., isopropanol, conveniently is added during the preparation of the aquasol at the point of addition of the quaternary. The addition of the alkanol helps stabilize the quaternary and to lessen gelation and precipitation tendencies. Generally, the mixture is stirred from about 1-60 minutes.
METHOD OF MANUFACTURE.
particle, Asthe first layer goes on, it neutralizes any charge (negative) on the silica particle and imparts an organophilic surface. At this point, the sol becomes less stable and there is a tendency for gelation or precipitation to occur. There is a decided thickening visually noticeable. The lower alkanol solvent which is a requisite acts to solubilize or disperse the coated sol in water. As the second coat becomes a layer, a different charge (positive) is imparted to the particle and the sol is restabilized. The second layer is oriented with its organophilic portion toward the surface and its ionic portion toward the solvent.
A preferred manufacturing process which enables the manufacture of thepresent double coated layer is as follows. In step one, the lower alkanol solvent is added to the quaternary amine in excess; As step two,
the colloidal silica is added with sustained mixing into 7 deionizedsol withthe properties like Nalco 1034A (see Table l). A silica sol of this type has little charge on its surface and tends to be more stable in the critical period during the application of the firist coating or in the intermediate stage of manufacture. Alternative commercial sols may, be used, but optimum results are obtained by utilization of sols having -190 M /gram average surface area. In the initial contact between the silica particle and the amine, the system may thicken, but the alcohol prevents gelation or precipitation until the system thins out when additional silica sol is added.
By the procedure of adding the sol to the amine solution, there is always an excess of amine and the two layers can go onto the silica sequentially. Further the simultaneous existence of both positive and negative sols is avoided.
The above is the preferred method for production of the'double layered sols. Other less preferred methods are by utilization of high shear mixing and in certain favored cases the elimination of the alcohol stabilizer.
THE AMOUNT OF QUATERNARY COATING ON SiO r The amount of the quaternary in'jrelation to the silica depends uponthe particle size of the colloidal silica.
The smaller the particle size, the more quaternary will I be required. In general, the ratio of SiO; to quaternary will be from 25 to l to 2 to l, and more often will be from 3:1 to 10:]. For an average particle diameter of 20 millimicrons a ratio of about} to l is typical.
The above percentage or concentration additions of quaternary have been found optimum in using the combination of Nalcoag 1034A and the quaternary dicoco dimethyl, ammonium chloride. However, additional variations over the range depending especially on the quaternaryselected arenecessary as the length of the long carbon chain or chains varies. The size of the silica particle also affects the amount of quaternary necessary. The purpose of the present invention is to produce a molecular double layer of quaternary and generally reversal of charge. v l
The present formulation uniformly requires a layer of quaternary which is physically sorbed and contains a molecular double layer. In the case of a charged silica sol, layer one, the innermost layeraround the silica,
of the quaternary silica compounds of the present in- I vention to pile fabric and carpets is usually in the nature of 14% by added weight based upon the percent of silica as Si0 added to the dry weight of the pile. Less than about 1% or in some cases, 0.5% gives lack of treating effect andabove 4% produces a white carpet or pile fabric.
in the past'it has been found that commercial quaternary compounds used as antistatic agents present a 1 very bad soiling problem and'in fact are prosoil agents. 1 However, in the present compounds, when'combined with silica, these carpet-treating preparations can be viewed as both antistatic and antisoil. The amount of coating or treating agent is similar to the prior art, for example, US. Pat. No. 2,622,307 Cogovan (Mohawk) at column 4, lines 33-49, when referring to the coating of colloidal silica on pile yarns. The combination of antistatic and soil-resistant components is also noted in the prior art in US. Pat. No. 3,033,699 Aarons et al. (duPont) which utilizes a combination of clay and colloidal silica sol and in that patent also is utilized the soil testing using Sanders and Lamberts synthetic soil at Example 1 and column 4.
FIG. 1 represents results from antistat tests at different percentages of silica where the half-life time expressed in seconds was measured according to the procedure of Example III-A.
In the followinng experimental procedures the antistatic effect is due to the quaternary component and is measured and observed on fabric samples treated by dip methods. The antisoil effect is due to the silica component and is measured on fabric samples treated by spraying.
EXAMPLE I Preparation of Quaternary Coated Silica Aquasols A 34% SiO sol in H O was coated with a fatty quaternary amine. To 11.2 parts of Arquad 2C-75 (dicoco dimethyl ammonium chloride) was added 3.5 parts of isopropanol followed by 85.3 parts of Nalcoag 1034A deionized silica sol. The preparation was repeated several times and it was noted that the results improved where slow addition was followed with good mixing in the preparation to avoid the formation of gel particles. It was further noted that the product went through a very thick stage as the 1034A silica sol was added, but the sol thinned out when it was all added. The product was found to be stable over a one-year period.
An additional run which doubled the amount of isopropanol was advantageous in thespeed of solubility of the quaternary. The silica sol utilized, Nalcoag 1034A, has a pH of 3.4. In separate runs, this pH was varied from 3.4 to 3.8 without adversely affecting the product. However, where the pH was lowered to about 2.9, difficulties were experienced with a cloudy product which did not exhibit a sol-like appearance.
Additional experiments or runs were made with Na]- coag 1050, a 50% colloidal SiO which had been diluted to about 35% and the results were quite similar to those obtained utilizing the 34% SiO or Nalcoag 1034A above as shown in Example 11.
EXAMPLE 11 Preparation of Double Coated Silica Sol To 33.6 grams of Arquad 2C-75 was added 10.5 grams isopropanol followed by 150 ml of Nalcoag 1050 silica sol diluted with 90 grams of water. The preparation was made with good mixing throughout the addition steps. The product became very thick during the Nalcoag 1050 addition but'thinned out again after a period of a few minutes. The product is stable over a one-year period.
EXAMPLE IIIA Antistatic Properties 1 Static electricity tests were done on pieces of nylon cloth pre-prepared by washing with detergent for 1 cycle and then washing without detergent for 1 cycle before drying. The nylon cloth was then cut into 5 inches X 5 inches squares and immersed in the test solution, wrung out to wet retention, thus giving a carry-over of 2.15% silica based on dry weight of the cloth, and dried at C for 5 minutes. Statis electricity tests were performed using the Stati'Tester, Model 169, from Most Associates, Inc., Marblehead, Massachusetts. A voltage of from 50-300 volts at 100 milliamps was applied to the nylon cloth. The initial voltage was measured and then the current shut ,off.The time required for the voltage to drop to half its initial value with no current applied was recorded as the half-life time. The shorter the time, the faster the charge dissipated from the cloth.
In the above, the quaternary utilized was dicoco dimethyl ammonium chloride and the original silica sol was 1034-A.
Results of the tests are shown below.
Treating Solution Initial Voltage Half-Life Time Water 215 10' min.
0.87% Quilt-2.15% 197 1.5 sec.
Silica Sol 215% Silica Sol 200 10 min.
The results show that the quaternary modified silica sol functions as an effective antistatic agent and that the silica sol alone does not.
EXAMPLE III-B Additional experiments were made utilizing the procedure of Example III-A but substituting di(hydrogenated tallow)dimethyl ammonium chloride, tallow trimethyl ammonium chloride, or lauryl trimethyl ammonium chloride for the dicoco dimethyl ammonium chloride utilized in Example III-A.
EXAMPLE III-C Utilizing the procedure of Example III-A, additional tests were made with different silica sols at a 1% solid silica level. Table II shows the results of the tests.
Prepared by producing an organic double coating on a silica solv 1034A. which double coating is dimethyl dicoco ammonium chloride. in such a manner that the product contains 30% SiO, and 8% quaternary. i
TABLE III Comparison of Product A vs Other Commercial Antistat Formulations Initial Half Life 26C emp Sample Dilution Voltage Time RH 8% Control 205 10 min. 1 (Chicago Tap Water) ProductA 1:8 1 sec. Statico 1:4 210 1 sec. Bonds EI-IP 1:26 80 0.5 sec.
TABLE Ill-Continued Sample Dilution Time RH 8% Voltage *Statico manufactured by Walter Leggc Company. Chicago. "Bonds E1-1P26-12 manufactured by Bond Chemical Products. Chicago. Both of the above compounds are fatty quaternary compounds.
EXAMPLE III-D Utilizing the test procedures of Examples Ill-A, B, and C, certain antistatic properties were ascertained as follows. The components of Product A were checked individually for their antisoiling characteristics. This was done at several concentration levels corresponding to the following dilution ratios of the product:
1. 1:8 dilution of Product A 2. 1:15 dilution of Product A A 1:8 dilution of Product A contains 3.9% silica and 1:6% quaternary (dicoco dimethyl ammonium chloride). A 1:15 dilution of Product A contains 2.5% silica and 0.87% quaternary. Tests were run on the individual components of each dilution for antistat values and the results are reported below in Table IV.
ammonium chloride The results show that the silica needs the quaternary double coating to give antistat properties to the product.
EXAMPLE IV-A Antisoil Properties Testing of Product A for antisoiling properties required formulating a synthetic dirt which would soil carpeting evenly. Following the recommendation of US. Pat. No. 3,033,699 Aarons et al. (duPont), a bulked Sanders & Lambert synthetic dirt was prepared. This dirt mixture is the standard dirt mixture used for antisoiling tests by industry and gives fairly reproducible results with even soilings.
90% nylon-10% wool carpet samples were sprayed with test solutions to give a coverage of about 2% silica based on the weight of the pile of the rug. After drying, the test samples were placed along the wall of a quart metal can. About 800% inch steel balls and 2.0g synthetic dirt were added to the can. The can was rotated on a set of rollers for 1% hour at 120 rpm. The carpet samples were then vacuumed and the brightness measured on a brightness meter made by Martin Sweets Co., Louisville, Ky.
The quaternary dicoco dimethyl ammonium chloride and the original silica sol was 1034-A.
Results of the tests are shown below.
Brightness Brightness After Soil- 7r of Treating Before ing and Original Solution Soiling Vacuuming Brightness Water 24.4 15.0 61.5 0.8% Quat- 24.4 16.4 67.2 2.15% Silica Sol 0.87% Quat 24.4 12.7 52.0
v The results show that the quaternary modified silica sol functions as an effective antisoilant and that the quaternary alone actually behaves as a prosoilant.
EXAMPLE IV-B Additional experiments were made utilizing the procedure of Example IV-A but substituting di(hydrogenated tallow) dimethyl ammonium chloride, tallow trimethyl ammonium chloride, or lauryl trimethyl ammonium chloride for the dicoco dimethyl ammonium chloride utilized in Example IV-A.
EXAMPLE rv-c Soiling characteristics of textile pile treated with Product A versus some selected commercial products are shown below in Table V.
TABLE v Soiling Tests of Product A Versus Selected'Commercial Products of Original Sample Dilution Brightness Brightness Original 24.9 100.0 Untreated 8L 14.2 57.0 Soiled Product A 1:8 15.0 60.2 Statico 1:4 1 1.9 47.8 Bonds EHP26-12* 1:26 10.5 42.2
*Statico manufactured by Walter Legge Co., Chicago. *Bonds El-1P2612 manufactured by Bond Chemical Products. Chicago. Both of the above compounds are fatty quaternary compounds.
EXAMPLE V Static and soiling characteristics of fabric treated with a composition similar to Product A except that the silica sol was an alkaline sol, Nalcoag 1050, rather than Nalcoag 1034A. Results are shown below.
TABLE VI 1 Antistat Values for Quat-IOSO Products Versus Product A The aqueous silica sol sold by Nalco Chemical Co., Chicago, under the name Nalcoag 1050. 5
TABLE V11 Antisoil Values for Quart-1050 Product Versus Product A 7: of Original Sample Dilution Brightness Brightness Original J 20.5 100.0 Untreated 13.1 63.9 & Soiled Product A 1:8 16.8 82.0 Quat-l050 1:8 17.3 84.4 Product A 1:15 16.1 78.5
The results indicate that the Quat-lOSO product from alkaline stabilized values gave both antistat and antisoil values comparable with the acid stabilized sol of Product A.
1. Synthetic bulk fabric having improved antistatic and antisoil properties, said fabric having been treated with an aquasol containing a minor amount of an aqueous polar solvent selected from lower alkanols having uniformly dispersed therein discrete dense colloidal particles of amorphous silica having an average particle diameter of 3150 millimicrons and average surface area of from about M /g to 1000 M /g, said silica particles having absorbed on their surfaces a quaternary ammonium salt or hydroxide, with the weight ratio silica, expressed as SiO to the quaternary ammonium being at least 2:1 wherein the quaternary ammonium has the formula:
wherein R R are methyl;
R is methyl or a C -C long hydrocarbon chain;
R is a C C long hydrocarbon chain;
X is an anion selected from the group consisting of chloride, bromide, iodide, and hydroxide.
2. The synthetic bulk pile carpet fabric according to claim 1 wherein the quaternary ammonium salt or hydroxide is dicoco dimethyl ammonium chloride.
3. The synthetic bulk pile carpet fabric according to claim 1 wherein the quaternary ammonium salt or hydroxide is di(hydrogenated tallow)dimethyl ammonium chloride.
4. The synthetic bulk pile carpet fabric according to claim 1 wherein the quaternary ammonium salt or hydroxide is tallow trimethyl ammonium chloride.
5. The synthetic bulk pile carpet fabric according to claim 1 wherein the quaternary ammonium salt or hydroxide is lauryl trimethyl ammonium chloride.