Note: Descriptions are shown in the official language in which they were submitted.
wo gl/19849 2 ~ Q 9 ~ PCT/US9l/03969
TITLE
STAIN-RESISTANT FABRICS
BACRGROUND OF THE INVENTION
S FIELD OF THE INVENTION
The present invention relates to stain-resistant
carpets having improved afterwash stain performance. More
particularly, it relates to a technique for improving the
afterwash stain performance of stain-resistant polyamide or
polyamide-blend carpets by incorporating a stainblocker
into the adhesive that is used to anchor the yarn tufts
into the primary backing.
PRIOR ART
Polyamide substrates, such as carpeting,
upholstery, fabric and the like, are subject to staining by
a variety of foodstuffs containing acid-dye colorants. The
treatment of polyamide substrates with acid-dye-resist,
levelling, or wet-fastness agents in order to render them
resistant to staining by acid dyestuffs, including food
dyes such as FD&C Red Dye No. 40, is well known in the art.
Stain-resist agents comprising sulfonated
naphthol- or sulfonated phenol-formaldehyde condensation
products and methods for treating polyamide carpets or
carpet yarn with these compositions to render the carpets
resistant to staining by acid dyes are disclosed in Ucci
and Blyth U.S. Patent No. 4,501,591, Blyth and Ucci U.S.
Patent No. 4,592,940, Blyth and Ucci U.S. Patent No.
4,680,212, and Greschler, Malone, and Zinnato U.S. Patent
No. 4,780,099.
Stain-resist compositions comprising mixtures of
sulfonated phenol-formaldehyde condensation products with a
hydrolyzed polymer of maleic anhydride and one or more
. ethyIenically unsaturated aromatic monomers are described
in Fitzgerald, Rao, Vinod, and Alender, U.S. Patent No.
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WO91/19849 2 0 g ~ PCTIUS91/03~9
4,883,839. Processes for applying these stain-resist
compositions are described in Fitzgerald, et. al. in their
pending application Serial No. 07/280,404 which is a
divisional application of the above-mentioned patent.
Polyamide substrates made stain resistant by such
compositions are the subject of another divisional
application, Serial No. 07/280,405. An alternate process
for applying these stain-resist compositions is disclosed
in Fitzgerald, Materniak, Moores, Openstone, and Rivet in
their pending application Serial No. 07/389,894.
Olson, Chang, and Muggli, U.S. Patent No.
4,822,373 discloses treatment of~fibrous polyamide
substrates to render them resistant to staining by acid
dyestuffs by applying thereto (a) a partially sulfonated
novolak resin and (b) polymethacrylic acid, copolymers of
methacrylic acid, or combinations of polymethacrylic acid
and copolymers of methacrylic acid.
Chang, Olson, and Muggli, EPO Published
Application 332,342 discloses a method for imparting stain
resistance to fibrous polyamide materials that involves
contacting the materials with an aqueous solution
comprising polymethacrylic acid, copolymers of methacrylic
acid, or combinations thereof.
Blyth and Ucci, U.S. Patent No. 4,61g,853
discloses polyamide carpets comprising a primary backing
and a pile coated with a sufficient amount of sulfonated
phenol- or naphthol-formaldehyde condensation product to
render the carpet stain resistant, wherein the underside of
the primary backing is coated with a carpet backing
adhesive composition containing a fluorochemical in an
amount sufficient to render the primary backing
substantially impervious to water. Ucci, U.S. Patent No.
4,579,762 discloses similar carpets wherein the carpet
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WO91/19~9 PCT/US91/03~9
fibers are shaped from nylon 6,6 or nylon 6 polymer
modified to contain as an integral part of its polymer
chain aromatic sulfonate units in an amount sufficient to
improve the acid dye-resist properties of the fibers. The
fluorochemical which is added to the carpet adhesive
composition renders the carpets impervious to water so that
soil and stains may be washed from the carpet without
wetting the carpet underpad.
In order to maintain the aesthetic appearance of
carpets, it is necessary to clean them periodically. The
stain-resist properties of polyamide carpets that have been
prepared using the stain-resist compositions and procedures
~ ~ ~~referenced above may be degraded when the carpet is cleaned
with various detergents. When this occurs, the carpet is
no longer sufficiently resistant to re-staining in the
areas where washing has occurred, and subsequent stains
resulting from spills containing acid-dyestuffs will leave
a stained area that cannot be completely cleaned, leaving
an undesirable visible stain. In some instances, this
prob}em may be overcome by applying more stain-resist
composition to the carpet pile in the initial treatment
process. However, this may lead to yellowing problems with
certain stain-resist compositions upon exposure of the
treated carpet to nitrogen oxides or ultraviolet radiation
due to the increased amount of stain-resist compositions on -
the carpet pile. Further, this increase in the amount of
stain-resist agent used to treat the carpet can lead to
effluent-treatment problems due to the increased amount of
stain-resist chemicals remaining in the used treatment
bath. Alternatively, the afterwash stain performance of
the carpet can also be improved by topically applying a
stainblocker to the installed carpet as taught by Vinod in
U.S. Patent 4,925,707 or by Moore et al. in U.S. Patent
4,908,149. Such processes, however, may be expensive for
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Wogl~lgug 2 0 ~ PCT/US91/03969 ~
the carpet owner, and the results can be variable depending
on the application methods used.
SUMMARY OF THE INVENTION
The present invention provides stain-resistant
polyamide carpets which exhibit improved stain-resist
performance after washing with a detergent, through
addition of a stain-resist composition to the adhesive used
to anchor the carpet tufts in the primary backing. The
present invention also makes it possible to apply less of
the stain-resist composition to the carpet pile than is
normally required. ~n some instances, the stain-resist
agent may be applied to the carpet pile under milder pH
conditions than~would have been necessary to achieve
acceptable afterwash performance when using standard
adhesives that do not contain a stain-resist composition,
thus increasing the life of the equipment used to apply the
stain-resist compositions.
It has also been found that the present invention ~'
increases the "tuft-bind" which is the term used to
describe the force necessary to completely remove a yarn
tuft from the carpet. The invention, therefore, serves to
more securely anchor the carpet yarns into the primary
backing.
DETAILED DE8CRTPTION OF TRE INVENTION
The carpets of the current invention are
constructed using methods well known in the art, except
that a modified adhesive composition containing a stain-
resist composition is used. A typical tufted carpet has a
primary backing of polypropylene or jute which may be woven
or nonwoven, stitched with tufts which generally are loops
and/or cut loops of polyamide carpet yarn which extend
upward from the backing to form the carpet pile. The
underside of the primary backing is coated with an adhesive
composition which serves to anchor the tufts in the primary
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wo gl/lg849 2 ~ 0 9 i pcr/us91/o3969
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backing. The carpet pile may be comprised exclusively of
polyamide yarns or of polyamide-blend yarns in which
polyamide fibers are blended with fibers of one or more
other types commonly used in carpeting, i.e. wool,
polypropylene, acrylic, etc. A secondary backing of woven
jute or polypropylene is usually applied to the underside
of the carpet following application of the adhesive. The
adhesive typically is a latex emulsion, which is dried and
heated in a separate curing step. Normally the weight of
the dry latex as applied to the carpet ranges from about
20-32 ounces/square yard (0.68-1.05 kg/m2), with 24
ounces/sq. yard (0.81 kg/m2) being most common. The carpet
is typica~ly installed with an underpad between the floor
and the carpet. Alternately, a foam may be applied to the
primary backing which serves to anchor the tufts as well as
to replace the secondary backing and padding. According to
the current invention, an adhesive is considered to be any
composition which is used to anchor the carpet tufts in the
primary backing. Examples include the latex emulsions and
foam compositions described above. The specific adhesive
used depends on the type of carpet construction and end use
(foriexample, residential, commercial, carpet tile,
; automotive carpet, etc.).
Examples of adhesive compositions which may be
used in the present invention comprise latex emulsions
which are known in the art for binding tufts of fiber in
primary carpet backings. Examples of adhesive polymers
useful in these emulsions are disclosed in Ucci U.S. Patent
No. 4,579,762 and include, but are not limited to,
polyvinyl acetates, polyacrylates, ethylene-vinylacetate
copolymers, styrene-butadiene copolymers and carboxy
styrene-butadiene copolymers. Typical foams include
urethane and latex compositions.
The amount of stain-resist agent required in the
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wo gl/19~9 2 ~ ~ 4 ~ ~ ~ PCT/US91/03~9 -
adhesive composition to provide a carpet having improved
afterwa~h performance will depend on the particular stain-
resist composition being used. It will also depend on the
nature of the carpet pile fibers, including the specific
polyamide polymer, the type of heatsetting process used,
the amount of stain-resist composition originally on the
carpet pile and the process used to apply the stain-resist
agent to the carpet pile fibers. The same stain-resist
agent that was used to treat the carpet pile fibers may be
used in the adhesive. Alternatively, a different
stain-resist agent may instead be used.
In a preferred aspect of the invention, the latex
contains from 0.04 to 3.0 weight percent of the active
stain-resist agent, the agents typically being supplied in
the trade in the form of aqueous stain-resist compositions
having concentrations from 20-30%. It is most preferred to
use compositions containing from 0.04 weight percent to 0.9
weight percent of the stain-resist agent based on the
weight of the latex.
The stain-resist agents are polymeric in nature
and are either condensation polymers, addition polymers
derived from one or more monomers having ethylenic
carbon carbon unsaturation, or mixtures of such
condensation and addition polymers. Generally, the
condensation polymers are derived from formaldehyde and
either a sulfonated phenol or a sulfonated naphthol, and
preferably a monosulfonated phenol. Generally, the
addition polymers contain repeating units derived from
maleic acid or methacrylic acid and up to 70 weight percent
of a comonomer having ethylenic unsaturation and containing
from 2 to 20 carbon atoms. More specifically, they include
those such as the type described in EP0 Publication No.
3S 0329899, published August 30, 1989, or in the
afoFementioned U.S. Patent No. 4,883,839 to Fitzgerald et
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WO91/19~9 2 ~ 8 ~ O ~ ~ PCT/USgl/03~9
al., the disclosure of each of which is incorporated herein
by reference. These polymers contain repeating units
derived from a hydrolyzed polymer of maleic acid and one or
S more ethylenically unsaturated aromatic comonomers.
Examples of such comonomers are styrene, alphamethyl
styrene, and stilbene. The maleic acid generally is
derived from maleic anhydride, that is, maleic anhydride is
polymerized to form either a homopolymer or a copolymer
such as with styrene. The polymerized maleic anhydride can
be hydrolyzed to maleic acid which, in turn, can be
partially or wholly converted to its stereoisomer fumaric
acid, such as by treating at an elevated temperature.
Other types of~addition polymers include those of the type
disclosed in the aforementioned EPO Published Application
332,342 to Chang et al. and U.S. Patent 4,822,373 to Olson
et al., each of which is also incorporated herein by
reference. Examples of these include the homopolymer
polymethacrylic acid and copolymers of methacrylic acid
with up to 70 weight percent of an ethylenically
unsaturated monomer such as alkyl acrylates having 1-4
carbon atoms, itaconic acid, and sodium sulfostyrene. The
alkali metal,salts of both the condensation and addition
polymers may also, of course, be used.
Additionally a soil-resist composition may also be
added to the adhesive in combination with the stain-resist.
Generally, the soil-resist compositions contain organic
compounds having a plurality of fluorine atoms which tend
to repel foreign materials, i.e., soil. Soil-resist
compositions may also, of course, be topically applied to
the fibers in the tufts in the conventional manner.
The polyamides used to form the fibers in the
tufts are aliphatic or cycloaliphatic in nature.
Generally, they have the formula
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WO91/19849 PCT/US91/03969 ~
~;) P O
-(NH--R--NH--~--R~ )n~ or -(NH--R2--~)m~
where -R-, -Rl-, and -R2- are divalent aliphatic or
cycloaliphatic radicals containing 4 to 20 carbon atoms.
Such polyamides include polyhexamethylene adipamide,
polyhexamethylene dodecamide, polycaprolactam, 6,6/6
copolyamide, polyaminoundecanoic acid, etc. The subscripts
n and m represent integers large enough to ensure fiber
forming characteristics of the poIyamide. Generally, the
number average molecular weight of the polymer will be from
lO,ooO to 500,000.
In typical stain-resistant carpets made with
standard, unmodified latex adhesives, stain-resist
compositions containing from as little as 0.2 to as much
1.5 weight percent active stain-resist agent (on weight of
fiber) are directly applied to the fibers in the tufts to
provide satisfactory stain-resistance both before and after
washing. The amount actually used will, of course, vary
depending on such factors as the specific stain-resist
being applied, the fiber polymer, heat-setting method, pH
and other application conditions. By use of the modified
latex compositions described herein, comparable performance
can be achieved with as much as about 10% less
stain-resist, i.e. by treating the carpet pile with about
0.18 to 1.35 wt.~ of the active agent.
T~st M~thods
In the test procedures and examples described
below, all percentages are by weight unless otherwise
indicated.
~ ~tain Test 1
;~` . Stain Test l used herein consists of two parts:
1) a 24 hour stain test on "As Is", i.e. tufted, dyed, and
latexed, but unwashed carpet; and 2) a 24 hour stain test
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WO91/19849 2 ~ ~ ~ 0 91 rcTluss1/o3s6s
on a carpet which has been subjected to a wash prior to
staining (referred to as "After Wash"). The staining agent
for both the "As Is" and "After Wash" evaluations is a
solution containing 0.054 g/l of Red Dye No. 40 prepared
from commercially-sold, cherry-flavored, sugar-sweetened
"Kool-Aid" premix. The solution is made by dissolving 45
grams of this "Kool-Aid" premix powder in 500 ml of water,
and it is allowed to reach room temperature, i.e., 75F
( +5F) or 24C (+3C), before using.
"As Is~ Evaluation
For the "As Is" evaluation, a carpet sample tufted
from approximately 15 grams of fiber is prepared. Half of
this sample is immersed in 40 cm3 of the staining agent. `~
The staining agent is worked into the tufts for uniform
staining. The sample is then placed on a flat
non-absorbent tray or surface. The sample is left
undisturbed for 24 hours ( +4). Then the stained sample is
rinsed thoroughly with cool tap water, extracted to remove
excess liquid, and dried.
The stain resistance of the carpet is visually
determined by the amount of color left in the stained area
of the carpet. This~is referred to as the stain rating,
and is herein determined according to the Stain Rating
Scale (a copy of which is currently used by and available
from the Flooring Systems Division of E.I. du Pont de
Nemours and Company, Wilmington, DE 19898). These colors
can be categorized according to the following standards:
5 = no staining
4 - slight staining
3 = moderate staining
2 = considerable staining
l s heavy staining
In other words, a stain-rating of 5 is excellent,
indicating good stain-resistance, whereas l is a poor
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WO91/19849 ~ 0~ ~ Q ~ i PCT/US91/03~9 ~
rating, indicating persistence of heavy staining.
~After Wa~h~ Evaluation
For the "After Wash" evaluation, a 15 gram sample
of carpet is prepared. A detergent solution is made by
adding 57 grams of "Dupanol WAQE", an aqueous composition
containing about 30 weight percent cf a surfactant made by
neutralizing the reaction product of chlorosulfonic acid
and lauryl alcohol (predominantly sodium lauryl sulfonate),
to 3.8 liters of water and adjusting the pH to 10.0 with an
aqueous solution of about 0.2% trisodium phosphate, and
allowing the solution to reach room temperature, i.e., 75F
(+ 5) or 24C (+ 3), before using. The carpet sample is
completeiy immersed in the detergent solution for 5
minutes, the detergent solution being discarded after each
wash. Then the sample is rinsed thoroughly with cool tap
water, extracted to remove excess liquid, and dried.
The staining agent is then applied and evaluated
in the same manner as described above in the "As Is"
evaluation.
For a carpet to be considered to have a
commercially acceptable level of stain-resistance, it
should have a rating of at least 4 on the above-described
Stain Rating Scale for both the "As Is" and "After Wash"
evalUatiOns.
8tain ~ra~t 2
The procedure followed in Stain Test 2 is
identical to that described for Stain Test l, both for "As
Is" and "After Wash" evaluation, except that a different
method is used for staining the carpet sample. Instead of
immersing half of the carpet sample in the staining agent,
the specimens are placed on a flat non-absorbent surface
and 20 ml of the staining agent is poured on each specimen
through a cylinder (1-1~2 to 2 inches (3.8 to 5.1 cm)
diameter) to form a 1-1/2 to 2 inch (3.8 to 5.1 cm)
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WO 91/19849 2 ~ i PCr/US9t/03969
circular stain. The cylinder is removed and the solution
worked into the tufts for uniform staining. The samples
are left undisturbed for 24 + 4 hours, rinsed thoroughly
with cool tap water, squeezed dry and an extractor used to
remove excess solution.
Tuft-Bind Neasurement
Tuft-bind is measured using ASTM D 1335.
EXAMP~E 1
BCF (bulked continuous filament) nylon 6,6 yarns
of 1150 total denier and comprised of 68 filaments (of
trilobal cross-section) were produced by a conventional
process. Two of these yarns were plied and twisted to
provide a yarn having a balanced twist of 3.5 turns per
inch (tpi). The resulting yarn was then conventionally
heat-set in a Superba heat-set apparatus at 270 degrees F
(132C). A cut pile tufted carpet was constructed from the
heat set yarn to the following specifications: 40 oz/sq.yd. ~ -
~1.36 kg/m2), 3/4 inch (l.9 cm) pile height, 1j8 inch gauge
20 t31-5 tufts/decimeter), 8 1/4 stitches per inch (3.25
stitches/cm). This carpet was dyed to a light blue shade
using a Kusters "Fluidyer~' on a continuous dye line. A
conventional continuous dye process (at 400% wet pick up)
and dye auxiliaries were used (color formula was the
25 following and based on the weight of carpet: 0.0200%
Tectilon Blue 4R-200 (C.I. Acid Blue 277), 0.0060% Tectilon
Red 2B-200 (C.I. Acid Red 361), and 0.0045% Tectilon Orange
3G-200 (C.I. Acid Orange 156), pH = 6.0). After dyeing, the
carpet was rinsed and extracted.
The carpet was then treated with a bath containing
a stain-resist composition on a Kusters "Flex-Nip" dyeing
apparatus. The specific stain-resist composition used was
an aqueous mixture of a hydrolyzed styrene/maleic anhydride
copolymer and a sulfonated phenol-formaldehyde condensate,
as described in the previously referenced patent U.S.
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wo 91/19849 2 0 8 '~ ~ ~ i PCT/US91/03969 -~
4,883,839. (The molar ratio of the copolymer was 1:1
styrene:maleic anhydride, and the copolymer had a number
average molecular weight of 1600). The stain-resist
composition was 75.3 wt% of a 30 wt% solution of the
styrene:maleic anhydride copolymer, 13.3 wt~ of a 30 wt%
solution of the phenol-formaldehyde condensate, and 11.4%
of the anionic surfactant "Alkanol ND", which contains 45
wt% of the disodium salt of dodecyldiphenyl oxide
disulfonic acid as its active ingredient. The bath was
prepared by water dilution of the stain-resist composition
to contain 5.4 wt~ of the composition owf ~on the weight of
fiber) or 1.2% owf based on active ingredient of the
hydrolyzed styrene~maIeic anhydride copolymer, 0.22% owf ~
based on active ingredient of the sulfonated
phenol-formaldehyde condensation product, and 0.28% based
on active ingredient owf of the anionic surfactant "Alkanol
- ND". The carpet sample was treated by adjusting the pH of
the stain-resist bath to 2.3 using sulfamic acid. The bath
was applied to the carpet samples in a Kusters "Flex-Nip"
at about 80 degrees F (26.7C) and 400% wet pick-up on
weight of fiber,~followed by steaming in a vertical steamer
for a residence time of 3 minutes. After the steamer, the
carpet was rinsed and extracted. The carpet was
subsequently treated with a commercial fluorochemical in a
conventional spray application and the carpet was dried in
an oven. This carpet sample is designated as Sample A.
Additional carpet samples were processed using the
same procedure as for Sample A except that the pH was
adjusted to 3.0, 3.5, and 4Ø These samples are referred
to as Samples B, C, and D respectively.
A commercially available styrene-butadiene latex
composition (Latex-V 9370 made by Colloids Inc., 207
Telegraph Ave. Gastonia, N.C. 28054) was hand applied to
sections of the carpet samples A-D and the carpets were
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WO91/19,~9 PCT/US91/03~9
oven-cured at 250 degrees F (121C) for 5-7 minutes.
Another set of samples was prepared using carpet Samples
A-D except that the latex composition was modified to
contain 1 wt% on the weight of latex (owl) of the same
stain-resist solution that was applied to the carpet pile.
In terms of the nonaqueous components, this corresponds to
0.23 wt% owl of the styrene-maleic anhydride copolymer,
0.04 wt% owl of the phenol-formaldehyde condensate, and
o.os wt% owl of the anionic surfactant, with the copolymer
and the condensation product being considered as the active
ingredients of the stain resist solution. This
stain-resist composition was added to the latex while
~~ stirring slowly for about 5 minutes using a Gifford Wood
mixer, Model 76-IL, made by J. W. Greer, Inc. The modified
latex, which contained the stain-resist composition, was
hand applied to the carpet and oven-cured using the same
conditions as described above. This set of carpet samples
is designated by sample numbers A' - D' in TABLE 1 below.
The dried latex weight on the carpet both for these samples
and for all the carpets described in these Examples was
approximately 30 oz/s~.yd. (1.02 kg/m2). The carpet was
tested for stain resistance by Stain Test 2. The results
from the Table l show that the samples with modified latex
containing the stain-resist composition exhibited improved
"after wash" stain performance versus samples with standard
latex for all the samples regardless of the application pH
of the stain-resist composition. The "as is" performance
was almost equal for all the samples. This demonstrates
that it is possible to apply the stain-resist composition
to the carpets at a higher pH (i.e. milder conditions) and
to achieve acceptable afterwash performance through the
` addition of stain-resist to the latex.
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wo gl/lg849 2 0 ~ Pcr/usg1/o3969
TABLE 1
Sample Bath Application 8tain Rating ' '
5 No. pH Latex As Is After Wash
A 2.,3 STANDARD 5 4-5
A' 2.3 MODIFIED 5 5 '
B 3.o STANDARD 4-5 3-4
l0 B~ 3.0 MODIFIED 5 4-5
C 3.5 STANDARD 4-5 4
C' 3.5 MODIFIED 4-5 4-5
15 D 4.0 STANDARD 5 3
D' 4.0 MODIFIED 5 4-5
EXAMPLE 2
The dyed carpet and the stain-resist composition as
described in Example l were used for this experiment. Two
' samples were prepared, one at 4.5% owf and the other at 3.75%
owf of the stain-resist composition, and are designated as
Samples E and F, respectively. ~ The stain-resist bath was
adjusted to a pH of 2.3 with,sulfamic acid. The samples were
finished with the standard latex and also with the modified
latex containing 1% owl of the stain-resist composition as
described in Example,l. These samples are referred to as
Samples E' and F' in TABLE 2 below. The samples were tested
using Stain Test 2. This example demonstrates that the use of
the stain-resist composition in the latex improves the staining
performance for the samp}es which are processed with less
stain-resist composition applied to the carpet pile.
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WO91/19849 PCT/US91/03969
TA~LE 2
% Stain Resist
Sample Composition in stain Rating
No. Bath (owf) Latex As Is After Wash
E 4.5 STANDARD 4-S 4-5
E' 4.S MODIFIED 5 4-5
F 3.75 STANDARD 4-5 4
F~ 3.75 MODIFIED 5 4-5
EXAMPLE 3
A mill-processed carpet sample was used in this
example. -The carpet was made from a BCF nylon 6,6 yarn of
1410 total denier. Two of these yarns were plied and
twisted to provide a yarn having a balanced twist of 4.0
tpi. The resulting yarn was then heat-set in a Superba
heat-set apparatus with stuffer box attachment at 270
degrees F (132C). A cut-pile tufted carpet was
constructed from the heat-set yarn to the following
specification: 28 oz/sq.yd.(0.94 kg/m2), 3/4 inch (1.9 cm)
pile height, 3/16 inch gauge (21 tufts/decimeter), 7.8
stitches per inch (3.07 stitches/cm). This carpet was dyed
to an off-white color using levelling acid dyes on a
Kusters continuous dye line. The carpet was then treated
in a Kusters "Flex-Nip" with 6.0% owf of the same
stain-resist composition as described in the Example 1,
except that the composition did not contain the "Alkanol
ND" surfactant. The stain resist composition was applied
at a pH of approximately 2.25.
Different samples of this carpet were then hand
coated with the unmodified standard latex of Example 1 and
the modified latex containing 1.0% owl of the same
stain-resist composition as described in Example l. The
stain performance o~ the sampl-s was evaluated ~sing Stain
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WOgl/19849 20~ J'~ PCT~US91/03969
16
Test 1 and the stain test results are reported in Table 3
below. The results show that the afterwash stain
performance of the commercially processed mill samples is
improved when the samples are finished with the modified
latex composition.
TABLE 3
10 ~atex 8tain Ratin~
As Is After Wash
STANDARD LATEX 5 3
MODIFIED LATEX 5 4-5
EXAMPLE 4
The same dyed and stain-resist treated carpet
samples as described in above Example 3 were used in this
example. In addition to using the modified latex of
example 3, two further modified latex compositions were
used for this experiment. The first comprised the
2 commercial latex used in previous examples and 1 wt% owl of
a combined stain and soil resist composition, identified as
SRC-l. SRC-l contains 8.72 wt% based on active ingredient
of the hydrolyzed styrene/maleic anhydride copolymer, 1.74
wt% based on active ingredient of the sulfonated phenol
formaldehyde condensate and 3.8 wt% based on active
ingredient of "Teflon" MF (a 30% active, anionic fluoro-
chemical commercially available from E. I. du Pont de
Nemours and Company, Wilmington, DE). The second modified
latex contained the commercial latex and 1% owl of the
"Teflon" MF fluorochemical composition.
The carpet samples were hand latexed, oven-cured
and then stain tested according to Stain Test 1. The
results show that the afterwash stain improvement is
greatest where the latex is modified with the stain-resist
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WO91/19849 ~ i PCT/US9t/03969
composition alone, followed by the one where the latex
contains both stain resist and soil resist (fluoro-
chemical). The sample where the latex is modified with the
soil-resist chemical (fluorochemical) alone did not improve
the afterwash stain performance.
~B~E 4
10 Latex Stain Rating
As I~ After Wash
STANDA~D LATEX 5 3
MODIFIED LATEX 5 4-5
LATEX + 1% SRC-1 5 4
LATEX + 1% "Teflon" MF 5 2-3
EX~MP~E 5
The dyed BCF carpet sample tufted from Superba-set
yarns as described in Example 1 was used in this example,
except the carpet was not treated with a stain-resist
composition. One sample was prepared with the standard
latex and four others were prepared with modified latex.
The latex of each of these samples was modified to contain
between 1% to 10~ owl of the same stain-resist composition
as that used for Example 3 (referred to as SRC-2 for
identification purpose below). Viewing both the
styrene-maleic anhydride copolymer and the condensation
product as active ingredients, the addition of 1~, 3%, 5%,
and 10% owl of this composition corresponds to the addition
of 0.2~ wt~, 0.81 wt%, 1.35 wt%, and 2.7 wt% respectively
of the active components. Another sample was prepared with
the standard latex to which was added 3 wt% owl of a
solution containing 30 wt% active ingredient of a
sulfonated phenolic formaldehyde condensate type
stain-resist composition (referred to as SRC-3 for
.
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WO 91/19U9 2 ~ f~ ~ Pcr/usg1/o396g `-
18
identification purpose below), i.e. 0.9 wt~ owl of the
condensation product itself. A jute secondary backing was
applied to all the samples after the latex coating. The
samples were then stain-tested using Stain Test 1. The
results reported in Table 5 below show that there is no
appreciable afterwash stain improvement-until the modified
latex contained 10% owl of the stain-resist composition
SRC-2. Even then, the sample showed some visible stain
(stain-rating of 3). However, it is surprising that it is
possible to impart some degree of stain-resistance to a
carpet pile that has not been treated with a stain-resist
agent simply by incorporating a stain-resist agent in the
latex adhesive. ~ ~ ~- ~ ~
TABLE 5
:
Product ~t~in Rating
As~ Is Aftor Wash
20 Standard Latex
Latex ~ 1% SRC-2
Latex + 3% SRC-2 1 1-2
Latex + 5% SRC-2 1 1-2
Latex + 10% SRC-2 1-2 3
"! ' Latex + 3% SRC-3
EXAMPLE 6
A mill-processed carpet sample made from 4.5
denier, unheatset nylon 6,6 staple was used in this
example. The carpet had the following construction: 16
oz/sq.yd. (0.54 kg/m2), 1/10 inch gauge (39.4
tufts/decimeter) and 1/4 inch (0.64 cm) pile height. The
carpet was dyed to a light yellowish beige color in a beck
dyeing process using premetallized dyes. one sample was
prepared by using a standard latex while others were
prepared with a modified latex containing varying
percentages of a stain-resist composition. All samples
.
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WO91/19W9 PCT/US91/03969
were hand latexed, and oven-cured, after which a jute
backing was applied. The stain-resist compositions added
to the latex were SRC-2 and SRC-3, as previously described
in Example 5. The SRC-2 concentration was varied between 1
wt% and 5 wt% owl, while SRC-3 was used at 3 wt% owl. All
the samples were then stain tested using Stain Test 1. The
results reported in Table 6 below show that there is a
marginal improvement in the afterwash performance for the
latex samples containing the stain-resist composition SRC-2
at 5% owl addition (1.35 wt% owl of the active components)
and at 3% owl (0.9 wt% owl of the active component) of
stain-resist composition SRC-3.
.. . . . .
TAB~E 6
Pro~uct Stain Rating
As IsAfter Wash
Standard Latex
Latex + 1% SRC-A 1 1-2
Latex + 3% SRC-A 1-2 1-2
Latex + 5% SRC-A 1-2 3
Latex + 3% SRC-B 2 3-4
Examples 5 and 6 demonstrate that the degree of
improvement in afterwash stain performance depends upon the
nature (i.e. the dye rate) of the pile yarn used. The
Superba-set yarn, being more open in structure, has a
higher dye rate than unheatset yarn, and thus is more
susceptible to staining. Thus, the Superba-set yarn
requires that more of the stain-resist agent be used in
order to achieve a specified level of stain performance.
Similarly, it is known that Suessen-set yarn is less
susceptible to staining than Superba-set yarn. It can
therefore be expected that less stain-resist agent would be
required for effective results on carpets tufted from
Suessen-set yarns. Since it is also known that nylon 6,6
.
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wo 91/19849 2 ~ ~ 4 Q ~ i PCT/US91/03969
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is less vulnerable to staining than other polyamides such
as nylon 6, it can be expected that adjustments in the
amount of stain-resist agent added to the latex will be
required depending on the specific polymer type in the
fiber.
EXAMPLE 7
The dyed carpet as described in the Example 1 was
used for this experiment. The carpet was treated in a
Kuester's "Flex-Nip" with 6.0S owf (1.62 wt% active
components) of the same stain resist composition as
described in Example 1, except that it did not contain the
"Alkanol ND" surfactant. The stain resist composition was
appIied at a pH of approximately 2.5. The samples were ~~~~~~ ~
finished with the standard latex and also with modified
latex compositions containing 2% owl of three stain-resist
compositions used commercially. Each of these stain-resist
compositions is chemically different from one another as
outlined in different patents. The samples, identified as
A (standard latex), and B, C, and D (modified latex), were
then tested using Stain Test 1. The results reported in
Table 7 below show that the afterwash stain performance is
improved with the modified latex regardless of the type of
the stain resist composition.
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wo gl/19849 2 ~ 9 ~ PCT/US9ltO3969
21
TABLE 7
Sample Latex Stain Rating
5 No. As I~ After Wash
A Standard s 4
B Modified with same stain 5 S
resist composition used to
treat carpet pile of
Example 7
C Modified with the stain 5 4-S
resist composition SRC-3
as described in Example 5
~ ~~ D Modified to contain FX-661, 5 5
a 25% active stain resist
composition available from
3M Co.
EXAMPLE 8
A carpet prepared and dyed as described in Example ..
1 was treated in a Kuester's "Flex-Nip" with a 5.0 % owf of
a stain-resist composition, identified as SRC-4, at a p~ of
approximately 2.5. The SRC-4 stain-resist composition was a
25% active solution of the sodium salt of a hydrolyzed
styrene-maleic anhydride copolymer of the type described in
EPO Publication No. 0329899, published August 30, 1989.
Samples were finished both with a standard latex and also
with modified latex compositions containing 1.0, 2.0, and
3.0 % owl of two different stain-resist agents. Those were
SRC-4, which is the same as that applied on the fiber, and
the other one, identified as SRC-5, which is a nominal 30%
active solution of "Mesitol" FC405S6D, a sulfonated
phenolic formaldehyde condensate product sold by Mobay
Corporation. The samples were then stain tested using
Stain Test 1 and evaluated for tuft-bind to determine the
: 35 ~orce required to pull a tuft completely out of each carpet
.
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wo gl/-g849 2 ~ ~ ~ Q ~ ~ PCT/US91/03~9 --
sample. The results reported in Table 8 below show that
the "As Is" and the "After Wash" stain performance are both
improved by the modified latex compositions, whether the
modification is by SRC-4 or SRC-5. As might be expected,
the results are best for 3.0~, followed by 2.0%, and then
1.0~ owl for either of the stain resist compositions. When
compared at equal percent addition of these stain resist
compositions, the overall improvement was better with stain
resist SRC-5 than with SRC-4. It can also be seen that the
presence of stain-resist in the latex has the effect of
more securely anchoring the tufts to the carpet's primary
backing as all the samples made with the modified latexes
had increased~tuft-bind values versus that of Sample l ~~~~~
which did not have stain-resist in the latex.
TABLE 8
8ample 8tain Rating Tuft-Bind
No. Latox A~ Is Aftor Wash lbs. ~kg)
l. Standard 4-5 2 7.0 (3.2) -
2. Modified Latex
with 1.0% 5 3 7.2 (3-3)
owl of SRC-5
3. Modified Latex
with 2.0% 5 4 7.5 (3.4)
owl of SRC-5
4. Modified Latex
with 3.0% 5 4-5 7.2 (3.3)
owl of SRC-5
5. Modified Latex
with 1.0% 4-5 2-3 7.2 (3.3)
owl of SRC-4
6. Modified Latex
with 2.0% 5 3 7-5 (3 4)
owl of SRC-4
7. Modified Latex
with 3.0% 5 3-4 7.7 (3.5)
~ owl of SRC-4
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