Imparting anti-soiling properties to fibers

Anti-soiling properties are imparted to fibers by applying thereto an effective amount of the neutralized phosphate ester of an aliphatic alcohol having from 12 to 22 carbon atoms in the chain.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates generally to the conditioning of fibers, esp. textile 
fibers. It relates particularly to a process for rendering such fibers 
anti-soiling. 
2. Prior Art Statement 
Chemical compositions are universally applied to fiber surfaces to improve 
subsequent processing and handling of the fibers, and/or to impart a 
particular porperty thereto. Such compositions generally provide 
lubrication, prevent static build-up, and afford a slight cohesion between 
adjecent fibers. Exactly what is applied depends in large measure upon the 
nature--i.e., the chemical composition--of the fibers, the particular 
stage in the processing or handling thereof, and the end use in view. For 
example, compositions denominated "spin finishes" are applied to synthetic 
fiber tows, usually after stretching thereof, and frequently prior to 
subsequent processing thereof, including crimping, drying, cutting into 
staple lengths, carding, drawing, roving, and spinning. Such compositions 
generally provide lubrication, prevent static build-up, and afford a 
slight cohesion between adjacent fibers. 
The application of chemical compositions to fibers is usually accomplished 
by contacting the fibers in the form of a tow, a yarn, or cut staple with 
a solution or an emulsion containing the desired chemical composition, 
employing standard padding, spraying (or overspraying) techniques. 
For quite some time a need has existed in the industry for an effective 
means to impart anti-soiling properties to fibers, especially those which 
are used in the fabrication of floor coverings such as carpets and the 
like. As a result of considerable research, a number of expedients have 
been proposed and numerous finish compositions and methods have been 
developed--all of which are found wanting in one or more important 
aspects. That is to say, those which result in the imparting of low-, 
instead of anti-soiling properties to the treated fibers are unacceptable 
in today's market, which requires products of the highest quality. 
Moreover, fluorochemical compositions such as "Scotchguard" and "Zepel C", 
which do impart anti-soiling properties to fibers, are not only very 
expensive, but often interfere with proper processing of the fibers. As a 
consequence, the use of such materials is effectively limited to 
oversprays for finished products such as carpets. 
Neutralized phosphate esters of aliphatic alcohols are not new, nor is the 
utilization of such materials as fiber finishes. In this regard, the 
following references are considered pertinent. 
PRIOR ART STATEMENT 
A. U.S. Pat. No. 2,742,379 discloses amine salts of alkyl esters of 
pentavalent phosphorus acids and their application to hydrophobic, 
non-cellulosic fibers in order to impart antistatic properties thereto. 
The alkyl chains have from 8 to 18 carbon atoms therein, and the esters 
are prepared by reacting 2 moles of alcohol with one mole of phosphoric 
pentoxide. Not disclosed or even remotely suggested is that anti-soiling 
properties may be imparted to such fibers if the neutralized phosphate 
ester has from 12 to 22 carbon atoms in the aliphatic chain--less than 12 
carbon atoms being unsatisfactory for this purpose--and if the ester is 
prepared by reacting 3 moles of alcohol with one mole of phosphoric 
pentoxide. 
B. U.S. Pat. No. 3,639,235 discloses the employment of a phosphoric acid 
ester of an ethylene oxide adduct of a C.sub.8 to C.sub.20 alkyl alcohol 
as an essential component of a fiber finish composition. In this art, 
phosphate esters of alkyl alcohols whether ethoxylated or not are 
considered as essentially equivalent, the choice of one or the other 
depending upon consideration of water dispersibility and emulsifying 
properties, which normally increase upon the introduction of a polyglycol 
chain. In this regard, U.S. Pat. No. 3,639,235 teaches the especial 
utility of the phosphoric acid esters of 2 to 8 mole ethylene oxide 
adducts of aliphatic alcohols. In sharp contradistinction thereto is the 
recognition in the present invention that even short polyglycol chains on 
the aliphatic alcohol destroy anti-soiling properties. (See Example 3, 
infra.) 
SUMMARY OF THE INVENTION 
The primary object of the present invention is to provide a process for 
rendering fibers, esp. textile fibers, anti-soiling. Related objects are 
to provide acrylic and polyamide fibers which are efficiently handled and 
readily processed, and which possess anti-soiling properties. 
The primary object of the invention is achieved by the provision of a 
process which comprises applying to fibers, esp. textile fibers, an 
effective amount of neutralized phosphate ester of an aliphatic alcohol 
having from 12 to 22 carbon atoms in the chain, the ester having been 
prepared by reacting about 3 moles of alcohol with one mole of phosphoric 
pentoxide. Especially advantageous results are achieved when such 
aliphatic alcohol is a monohydric alcohol, and when this aliphatic 
monohydric alcohol is saturated. Highly efficacious results are obtained 
when a low-soiling spreading agent, such as a sodium dialkyl 
sulfosuccinate, is employed in admixture with the neutralized phosphate 
ester of the aliphatic alcohol. 
One of the related objects of the invention is achieved by the provision of 
an acrylic fiber having anti-soiling properties, the fiber having 
incorporated thereon a finish comprising from about 0.1 to 1 percent by 
weight of the neutralized phosphate ester of a saturated aliphatic 
monohydric alcohol having from 12 to 22 carbon atoms in the chain, the 
ester having been prepared by reacting about 3 moles of alcohol with one 
mole of phosphoric pentoxide. Highly advantageous results are achieved 
when a low-soiling spreading agent--esp. a sodium dialkyl sulfosuccinate 
in an amount sufficient to provide from 1 to about 10 percent by weight of 
the incorporated finish--is employed in admixture with the neutralized 
phosphate ester of the saturated aliphatic monohydric alcohol. 
Another related object of the invention is achieved by the provision of a 
polyamide fiber having anti-soiling properties, the fiber having 
incorporated thereon a finish comprising from about 0.2 to 2 percent by 
weight of the neutralized phosphate ester of a saturated aliphatic 
monohydric alcohol having from 12 to 22 carbon atoms in the chain, the 
ester having been prepared by reacting about 3 moles of alcohol with one 
mole of phosphoric pentoxide. Highly advantageous results are achieved 
when a low-soiling spreading agent--esp. a sodium dialkyl sulfosuccinate 
in an amount sufficient to provide from about 1 to about 10 percent by 
weight of the incorporated finish--is employed in admixture with the 
neutralized phosphate ester of the saturated aliphatic monohydric alcohol.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
For a more complete understanding of the present invention, reference 
should be made to the following detailed description of the preferred 
embodiments thereof. 
The nuetralized phosphate ester of an aliphatic alcohol having from 12 to 
22 carbon atoms in the chain, as employed in the present invention, is one 
of many available commercially. Such are commonly prepared by reacting the 
chosen aliphatic alcohol with P.sub.2 O.sub.5, which results in the 
formation of a mixture of mono- and diester. The residual acidity of this 
reaction product is then neutralized, as with caustic or an amine. The 
chosen aliphatic alcohol may be saturated or unsaturated; and it may have 
a straight chain or a branched configuration. Although monohydric alcohols 
have been especially advantageously employed, polyhydric alcohols are not 
considered to be lacking in utility. In any event, it is essential that 
the aliphatic chain be no shorter than 12 carbon atoms and that there be 
no polyglycol branches (howsoever short) on the aliphatic alcohol chain, 
since either condition will vitiate the otherwise-imparted anti-soiling 
properties, as is evidenced by the specific Examples, infra. Moreover, the 
ester should be prepared by reacting about 3 moles of alcohol with one 
mole of phosphoric pentoxide. 
The fibers to which anti-soiling properties are imparted are advantageously 
any of the textile fibers, especially man-made textile fibers such as 
acrylic and polyamide. Of particular importance are (a) acrylic fibers 
which have been spun from solutions of acrylonitrile polymers in inorganic 
solvents (see, e.g., U.S. Pat. No. 2,916,348 and U.S. Pat. No. 2,558,730) 
or organic solvents (see Knudsen, Textile Research Journal, 33, 13-20 
(1963) ); and (b) polyamide fibers such as polycaprolactam which are melt 
spun employing standard techniques well known in the art (see Moncrieff, 
Man Made Fibers, John Wiley & Sons, Inc., 5th Ed., pp. 326-335 and 543-561 
(1970) ). 
The neutralized phosphate ester of the aliphatic alcohol is efficaciously 
applied to the fibers as a solution or dispersion, esp. as an aqueous 
dispersion, by any of a number of standard means such as spraying, 
padding, or the like, at virtually any stage in the processing of the tow, 
staple or spun fibers, advantageously after streathing thereof, or after 
the fabrication of the fibers or a yarn containing them into a finished 
construction, such as a floor covering (e.g., a carpet). To be effective 
in imparting anti-soiling properties to the fibers, the neutralized 
phosphate ester of the aliphatic alcohol is employed in an amount 
sufficient to provide from about 0.1 to about 2 percent by weight, based 
upon the weight of the fibers. When acrylic fibers are utilized, the 
effective amount of neutralized phosphate ester is from about 0.1 to about 
1 percent by weight; when polyamide fibers such as polycaprolactam are 
utilized, the effective amount of neutralized phosphate ester is from 
about 0.2 to about 2 percent by weight. 
In order to enhance the uniformity of application of the neutralized 
phosphate ester of the aliphatic alcohol, a low soiling spreading agent is 
beneficially employed in simple admixture therewith. This spreading agent, 
which is conveniently and advantageously provided in an amount sufficient 
to provide from about 1 to about 10 percent by weight of the incorporated 
fiber finish, is profitably a sodium dialkyl sulfosuccinate, esp. the 
dioctyl, di-isobutyl, diamyl, dihexyl, di-tridecyl, or di-octadecyl. Such 
spreading agents are disclosed in U.S. Pat No. 3,306,850 and U.S. Pat. No. 
3,428,560. Other spreading agents which might be employed are sulfo 
succinamates, as well as sodium alkyl naphthalene sulfonate. 
The present invention, especially its primary and related objects and 
multiple benefits, may be better understood by referring to the following 
examples, which are set forth for illustrative purposes only. 
EXAMPLE 1 
Acrylic carpet fiber was stock dyed to a yellow shade, oversprayed with 8% 
water, carded, spun into carpet yarn, and tufted into a carpet of level 
loop construction. No processing lubricant or antistat was used. Test 
samples of 2".times.2" size were cut and the face sprayed with 7% water 
and dispersed therein 0.5% finish solids (percentages are based on the 
weight of the carpet sample). The samples were dried for 2 hours at 
115.degree. C. and let cool for 10 minutes at ambient temperature. All 
samples of one series were then shaken with an excess of soil in a glass 
jar for 10 minutes. The samples were then vacuum cleaned. The soil 
consisted of carpet sweepings from a vacuum cleaner (through 100-mesh 
screen) with 0.65% carbon black and 0.65% Nujol mineral oil added. The 
reflectance at 700 m.mu. was determined in a Large Sphere Color Eye. The 
percent reflectance R was converted into the Kubelka-Munk function K/S 
which equals (1-R).sup.2 /2R and is an approximate measure of colorant (or 
dirt in this case) concentration. By subtracting K/S obtained on an 
unsoiled carpet piece of the same kind from the K/S of a soiled sample, a 
comparative reading of the amount of dirt on each sample can be obtained. 
Experimental data on hydrogenated tallow alcohol ("HTA" containing 4% 
C.sub.14, 30% C.sub.16, 65% C.sub.18, 1% C.sub.20)phosphate salts are 
shown in Table I. DEA=diethanolamine: TEA=Triethanolamine. 
All of the phosphate esters of the present invention which are formed in 
the instant and following examples were prepared using a molar ratio of 
alcohol to phosphoric pentoxide of 3/1. 
TABLE I 
______________________________________ 
.DELTA.K/S 
Se- Change 
ries .DELTA.K/S 
From 
No Overspray K/S Soil Control, % 
______________________________________ 
1 None (unsoiled) 0.0526 
Water only (Control) 
0.538 0.485 
HTA Phosphate K-salt 
0.291 0.238 -51 
HTA Phosphate DEA salt 
0.502 0.449 -7 
2 Water Only (Control) 
0.645 0.592 
HTA Phosphate K-salt 
0.441 0.388 -35 
HTA Phosphate Na-salt 
0.414 0.361 -39 
HTA Phosphate TEA salt 
0.481 0.428 -28 
HTA Phos. Morpholine salt 
0.440 0.387 -35 
______________________________________ 
It can be seen that all overspray finishes applied decrease the soiling, 
i.e. have antisoiling properties. 
In Table II, a similar comparison is shown between phosphate esters of 
different alkyl chain length. The chains are unbranched except where 
indicated. 
TABLE II 
______________________________________ 
.DELTA.K/S 
Change 
Series .DELTA.K/S 
from 
No Overspray K/S Soil Control, % 
______________________________________ 
3 None (Unsoiled) 0.0526 
Water Only (Control) 
0.537 0.484 
C.sub.8 -C.sub.10 Alcohol Phosphate 
1.535 1.482 +206 
K-salt 
Iso-C.sub.10 Alcohol Phosphate 
1.570 1.517 +213 
K-salt 
Lauryl Alcohol Phosphate 
0.469 0.416 -14 
K-salt 
______________________________________ 
It can be seen that the phosphate esters made from C.sub.8 -C.sub.10 
alcohols lead to more soiling than the control. Contrary to this, lauryl 
(C.sub.12) alcohol phosphate imparts antisoiling properties. 
EXAMPLE 2 
Acrylic carpet was made from stock dyed (yellow) fiber but the carpet 
construction in this series was cut pile. Otherwise, the experimental 
steps and tests were the same as described in Example 1. Table III shows 
data confirming that C.sub.8 -C.sub.10 alcohol phosphates do not confer 
antisoilingl properties but C.sub.12 (lauryl) alcohol phosphate does. 
Furthermore, C.sub.14 and hydrogenated tallow (C.sub.14 -C.sub.20) alcohol 
phosphates are shown to be antisoiling finishes. 
TABLE III 
______________________________________ 
.DELTA.K/S 
Se- Change 
ries .DELTA.K/S 
From 
No Overspray K/S Soil Control, % 
______________________________________ 
4 None (Unsoiled) 0.0691 
Water Only (Control) 
0.858 0.789 
C.sub.8 -C.sub.10 Alcoh. Phos. K-salt 
1.883 1.814 +130 
iso-C.sub.10 Alcoh. Phos. K-salt 
1.920 1.851 +135 
Lauryl Alcoh. Phos. K-salt 
0.797 0.728 -8 
5 Water Only (Control) 
0.631 0.562 
C.sub.14 Alcoh. Phos. K-salt 
0.450 0.381 -32 
C.sub.14 -C.sub.20 (HTA) Phos. K-salt 
0.475 0.406 -28 
______________________________________ 
EXAMPLE 3 
The sample preparation was the same as in Examples 1 and 2. All samples are 
stock dyed (yellow). The carpet construction is noted in the table. This 
example is to demonstrate the deleterious effect of ethoxylation on the 
alkyl alcohol. In other words, phosphated polyglycol alkyl ethers do not 
show antisoiling properties. 
TABLE IV 
__________________________________________________________________________ 
Series 
Carpet .DELTA.K/S 
.DELTA.K/S Change 
No Construct. 
Overspray K/S Soil 
From Control, % 
__________________________________________________________________________ 
6 Cut Pile 
None (Unsoiled) 0.0691 
Water Only (Control) 
0.631 
0.562 
C.sub.12 -.sub.14 Alcohol + 3EO, Phos. K- 
1.700 
1.631 
+190 
C.sub.16 -C.sub.18 Alcoh. + 6EO, Phos. K- 
1.811 
1.742 
+210 
7 Cut Pile 
Water Only (Control) 
0.660 
0.591 
Oleyl Alcoh. + 5EO, Phos. K- 
1.566 
1.497 
+153 
Oleyl Alcoh. + 7EO, Phos. K- 
1.322 
1.253 
+112 
Oleyl Alcoh. + 19EO, Phos. K- 
1.621 
1.552 
+163 
8 Level Loop 
None (Unsoiled) 0.526 
Water Only (Control) 
0.355 
0.302 
C.sub.16 -C.sub.18 Alcoh. + 10EO, Phos. K- 
0.961 
0.908 
+200 
C.sub.16 -C.sub.18 Alcoh. + 15EO, Phos. K- 
0.970 
0.917 
+204 
C.sub.16 -C.sub.18 Alcoh. + 20EO, Phos. K- 
0.878 
0.825 
+173 
__________________________________________________________________________ 
EXAMPLE 4 
Acrylic carpet fiber was made with 0.2% hydrogenated tallow alcohol 
phosphate, K-salt as the finish applied to the tow, before crimping and 
cutting into staple. This fiber was oversprayed with 8% water, carded, 
spun into yarn, and tufted into a level loop carpet of natural color 
(Sample 1). Another part of the staple was oversprayed with an additional 
0.4% of the same finish besides 8% water and made into a level loop carpet 
(Sample2). Both carpets were tested in the Tetrapod Accelerated Wear 
Tester in contact with carpet sweepings from a vacuum cleaner. Samples 
were removed after 10,000; 15,000; and 30,000 drum rotations (cycles). 
TABLE V 
______________________________________ 
K/S 
Increase 
30,000 
Over 
Sample 
Unsoiled 10,000 15,000 
Cycles 
unsoiled, 
No % Reflect. 
K/S K/S K/S K/S % 
______________________________________ 
1 73.55 0.0476 0.155 0.311 0.335 604 
2 72.24 0.0533 0.152 0.234 0.245 360 
______________________________________ 
It can be seen that an increase in the finish by a factor of 3 results in a 
decrease in soiling by a factor of 1.7. 
EXAMPLE 5 
Nylon 6 carpet staple was made into a level-loop carpet. After piece dyeing 
(yellow) and drying, 1% hydrogenated tallow alcohol (HTA) phosphate, 
K-salt, dispersed in 3% water, (percentages are based on carpet weight) 
were brushed onto the face of a 2".times.2" piece of this carpet. After 
drying at 80.degree. C. for 2 hours, followed by 15 minutes at 115.degree. 
C., and cooling for 10 minutes, this sample and a control (water brushed 
on and treated in a like manner) were shaken with soil (composition given 
in Ex. 1) in a glass jar for 10 minutes and then vacuum cleaned. The 
results of reflectance measurements are given in Table VI. 
TABLE VI 
______________________________________ 
.DELTA.K/S 
.DELTA.K/S Change from 
Finish K/S Soil Control % 
______________________________________ 
None (Unsoiled) 
0.0363 
Water Only, Control 
0.155 0.119 
HTA Phosphate K-salt 
0.139 0.103 -13 
______________________________________ 
EXAMPLE 6 
Two commercial level-loop acrylic "heather" type carpets containing 70% 
fiber of natural color were floor tested. The natural fiber in carpet No. 
1 was made with 0.25% hydrogenated tallow alcohol phosphate, K-salt, as 
the finish applied to the tow on the fiber production line before crimping 
and cutting into staple. The natural fiber in carpet No. 2 was made in the 
same way but with 0.25% n-octyl/n-decyl alcohol phosphate, K-salt, as the 
finish. Everything in fiber processing and carpet tufting was the same for 
both carpets. The two carpets were laid on the floor side-by-side in a 
heavy traffic area. After 22,000 steps and vacuum cleaning, the difference 
in soiling could clearly be seen. Carpet No. 2 had picked up significantly 
more soil than carpet No. 1. Table VII shows reflectance measurements 
similar to those reported in the previous examples. 
TABLE VII 
______________________________________ 
.DELTA.K/S 
Car- Unsoiled Soiled on Floor Increase 
pet % % .DELTA.K/S 
Over 
No Reflect. K/S Reflect. 
K/S Soil unsoiled, % 
______________________________________ 
1 61.59 0.1198 54.46 0.1904 
0.0706 
59 
2 61.80 0.1181 50.75 0.2390 
0.1209 
102 
______________________________________ 
It can be seen that the carpet containing natural fiber with C.sub.8 
-C.sub.10 alcohol phosphate picked up 73% more dirt than the one 
containing the same proporation of natural fiber with hydrogenated tallow 
alcohol phosphate. 
EXAMPLE 7 
Acrylic carpet fiber was made with 0.25% of a finish consisting of 95% 
hydrogenated tallow alcohol phosphate, K-salt, and 5% sodium dioctyl 
sulfosuccinate. The finish was applied to the tow, before crimping and 
cutting into staple. This fiber was oversprayed with 8% water, carded, 
spun into yarn, and tufted into a level-loop carpet of natural color 
(Sample 1). In a paralleled experiment, the finish consisted of 
hydrogenated tallow alcohol phosphate only (Sample 2.). Both carpets were 
tested in the Tetrapod Accelerated Wear Tester in contact with carpet 
sweepings from a vacuum cleaner. Samples were removed after 10,000 and 
20,000 drum rotations (cycles), vacuum cleaned, and reflectance 
measurements made for judgement of soil pickup. The addition of the 
spreading agent did not interefore with the low-soiling characteristics of 
the phosphate ester finish. 
EXAMPLE 8 
In accordance with the procedure of Example 1 of the present application, 
acrylic carpet fiber was stock dyed to a yellow shade, oversprayed with 8% 
water, carded, spun into carpet yarn, and tufted into a carpet of level 
loop construction. No processing lubricant or antistat was used. Test 
samples of 2".times.2" size were cut and the face sprayed with 7% water 
and dispersed therein 0.5% finish solids (percentages are based on the 
weight of the carpet sample). The samples were dried for 2 hours at 
115.degree. and let cool for 10 minutes at ambient temperature. All 
samples of one series were then shaken with an excess of soil in a glass 
jar for 10 minutes. The samples were then vacuum cleaned. The soil 
consisted of carpet sweepings from a vacuum cleaner (through 100-mesh 
screen) with 0.65% carbon black and 0.65% Nujol mineral oil added. The 
reflectance at 700 mu was determined in a Large Sphere Color Eye. The 
percent reflectance R was converted into the Kubelka-Munk function K/S 
which equals (1-R).sup.2 /2R and is an approximate measure of clorant (or 
dirt in this case) concentration. By subtracting K/S obtained on an 
unsoiled carpet piece of the same kind from the K/S of a soiled sample, a 
comparative reading of the amount of dirt on each sample can be obtained. 
Experimental data on hydrogenated tallow alcohol ("HTA" containing 4% 
C.sub.14, 30% C.sub.16, 65% C.sub.18, 1% C.sub.20) phosphate salts are 
shown in Table VIII below. Due to the presence of an additional filter in 
the Large Sphere Color Eye, the K/S values shown in Table VIII below are 
higher than those shown in Table I of Example I of the application, but 
there is strict comparability between the values in each group. 
TABLE VIII 
______________________________________ 
% .DELTA.K/S 
Series No. 
Overspray Reflectance 
K/S Soil 
______________________________________ 
9 None (unsoiled) 
35.28 0.594 -- 
HTA Phosphate, K- 
salt, Alcohol P.sub.2 O.sub.5 3/1 
24.62 1.154 0.560 
HTA Phosphate, K- 
salt, Alcohol/P.sub.2 O.sub.5 2/1 
20.69 1.520 0.926 
10 None (unsoiled) 
35.28 0.594 -- 
HTA Phosphate, K- 
salt, Alcohol/P.sub.2 O.sub.5 3/1 
24.16 1.190 0.596 
HTA Phosphate, K- 
salt, Alcohol/P.sub.2 O.sub.5 2/1 
20.45 1.547 0.935 
HTA Phosphate, K- 
salt, Alcohol/P.sub.2 O.sub.5 2/1 
20.41 1.552 0.958 
Larger-scale product 
______________________________________ 
From Table VIII it can be seen that the carpet samples with the HTA 
phosphate made at a molar ratio of 2/1 are unacceptable in that they soil 
60-65% more than those with HTA phosphate made at a molar ratio of 3/1.