Note: Descriptions are shown in the official language in which they were submitted.
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SOIL RELEASE TREATMENT FOR MOISTURE WICKING SOCKS
FIELD OF THE INVENTION
The present invention relates to hosiery, and especially to socks, treated
with a
soil release composition. The treated socks are constructed from yarns
comprising
polyester and polyester blends with cotton and other fibers. More particularly
the treated
socks comprise yarns of high moisture wicking capacity further comprised of
fine
filaments of a cross-section which enables moisture movement.
BACKGROUND OF THE INVENTION
Compositions for the treatment of fabrics to prevent soil re-deposition
properties
are known. Such compositions are known from European Patent number EP1225269
B1 assigned to CIBA Specialty Chemicals. These compositions have been shown
effective when used with cotton containing textiles of 30 to 100% in mixtures
with either
polyester or polyamide. Pure synthetic fibers of polyester or polyamide are
also usually
treated by such compositions. Here the benefit sought is one of enhanced
retention of
the white color over multiple washing cycles, along with hydrophilicity and
stain release.
Yarns of high moisture wicking capacity such as those sold under the COOLMAXO
brand name (INVISTA S.a r.l.), comprise fine polyester filaments with special
cross-
sections designed to achieve enhanced moisture movement properties. Such yarns
are
widely used in hosiery, especially socks. Often combined with other yarns such
as
cotton, along with portions of nylon and spandex, these yarns fill a niche in
the
manufacture of white athletic socks. A deficiency of fabrics comprising
special cross
section fibers is a dingy appearance, or less "white" appearance, over time
after
repeated home washings. This poor color appearance, lack of newness retention
over
time with numerous wearing and washings is noted by customers and provokes
some
return of goods to retail stores.
Due to the high retention of white appearance required for athletics socks
after
repeated consumer use, treatments to enhance the release of soil have been
sought.
Such treatments have been sought especially for apparel and for socks knit
from yarns
composed of polyester fiber having specialized cross-sections aimed at
enhanced
moisture movement. Socks of this type sold under the COOLMAXO brand name pass
strict moisture management criteria to meet brand requirements. Potential
added value
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for socks of this type could be derived from their enhanced maintenance of a
white
appearance.
Thus there is a need to develop an improved foot apparel product that meets
both the high moisture management standards of the industry while improving
color and
newness retention.
SUMMARY OF THE INVENTION
The invention provides a treated garment comprising at least 50% polyester
multifilament yarns. The multifilament yarns are comprised of filaments having
a profiled
individual filament cross section. The treated garment is given a treatment
with a
fluorine containing durable soil release composition. The treated garment is
characterized by a wicking height at least 75 millimeters according to a
vertical water
wicking test method, a stain release rating of at least 3, as measured by
AATCC
(American Association of Textile Chemists and Colorists) Test Method 130-2000,
and at
least a 1.0 unit improvement in soil re-deposition according to the soil re-
deposition test
method provided herein. The treated garment may further comprise a balance of
yarns
selected from yarns comprising non-profiled individual filaments selected from
natural
cotton and synthetic polymer fibers: polyester, polyamide and spandex yarns.
The
treated garment may further comprise a sock or at least a pair of socks.
Further provided in accordance with the invention is a process for treating
garments comprising at least 50% polyester multi-filament yarns comprised of
filaments
having a profiled individual filament cross section, and comprising the steps
of: applying
a fluorine containing durable soil release treatment in an aqueous exhaustion
bath at
greater than 5% based on weight of garments and less than 50 to 1 garments to
bath
ratio; dropping the treatment bath without an intervening rinse step; drying
the garments
in a tumble dryer or the equivalent of an automatic dryer; and curing garments
while
individually boarded at a temperature between 110 C and 190 C for time period
of
about 60 to about 90 seconds.
DETAILED DESCRIPTION OF THE INVENTION
According to one aspect of the invention, the applicants have found that a
fluorine containing durable soil release composition applied as a final wet
treatment on
garments comprising a majority of profiled cross section filament yarns
promotes the
retention of garment whiteness and new appearance after extended wash cycles.
An
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effective fluorine containing durable soil release composition for this
treatment process is
ZONYLO SRM (CIBA SPECIALTY CHEMICALS, Textile Effects, 3400 Westinghouse
Boulevard, Charlotte, North Carolina 28241, USA). The garments for which the
inventive process is most effective comprise a high content of polyester multi-
fiiament
yarns. The balance of yarns with less than 100% polyester further comprise
portions of
cotton, polyamide (e.g. nylon 66 and nylon 6) yarns, polyester circular cross
section
filament yarns and spandex (e.g. LYCRAO and LYCRAO T400). A high content means
greater than or equal to 50% and up to 100% polyester content. The filaments
of these
polyester yarns most effectively treated comprising profiled filaments.
Herein, profiled
filaments means having a non-circular cross-sectional shape as viewed normal
to the
long axis of the filament. One such profiled filament type is found in
COOLMAXO yarns
(INVISTA, S.a r.l.; Three Little Falls Centre, 2801 Centerville Road,
Wilmington,
Delaware 19808 USA). COOLMAXO yarns have a special cross-section which
provides
"4 channels" in each filament and are known for highly effective moisture
wicking
properties due to the presence of these channels. Fabrics of these yarns may
take on a
dingy appearance, or less "white" appearance, over time after repeated home
washings.
The processes herein and the products treated accordingly, by contrast, do not
have this
poor color appearance or lack of newness retention over time with numerous
wearing
and washings.
More generally, this invention provides a treated garment comprising at least
50% by polyester (from polyethylene terephthalate synthetic polymer)
multifilament
yarns. The multifilament yarns are comprised of filaments having a profiled
individual
filament cross section. The treated garment is given a treatment with the
fluorine
containing durable soil reiease composition, ZONYLO SRM. The treated garment
is
characterized by a wicking height at least 75 millimeters according to a
vertical water
wicking test method, a stain release rating of at least 3, as measured by
AATCC Test
Method 130-2000, and at least a 1.0 unit improvement in soil re-deposition
according to
the soil re-deposition test method provided herein. The treated garment may
further
comprise a balance of yarns selected from natural cotton yarns; non-profiled
individual
filament polyester, polyamide and spandex yarns. The treated garment may
further
comprise a sock or at least a pair of socks. More generally, the treatment
herein is
provided for socks which have a mostly white colored visual aesthetic.
The process, provided in accordance with the invention, treats garments
comprising at least 50% polyester multi-filament yarns comprised of profiled
individual
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filaments and comprises the steps of: applying a fluorine containing durable
soil release
treatment in an aqueous exhaustion bath at greater than 5% based on weight of
garments and less than 50 to garments to bath ratio; dropping the treatment
bath
without an intervening rinse step; drying the garments in a tumble dryer or
the equivalent
of an automatic dryer; and curing garments while individually boarded at a
temperature
between 110 C and 190 C for time period of about 60 to about 90 seconds. This
process is effective in promoting whiteness retention after extended wash
cycles. The
whiteness retention property is demonstrated using a standard washing protocol
and a
synthetic standardize "dirt." The test method measures the property of the
treated
fabrics to appear clean and not dingy without re-deposition of soil on the
fabric from the
wash water. The treated garments also meet a stain release requirement of at
least 3 as
measured by AATCC Test method 130-2000. The treated garments also meet a
strict
requirement for "whiteness" retention during the "boarding" or cure process
and a strict
moisture management standard. The moisture management standard is measured by
a
125 mm (5 inch) water wicking height and 5 square centimeter spreading area
known in
the art for this category of hosiery (sock) product. Furthermore, the
retention of the
benefits of this fabric treatment is durable. Durable means the treatment
benefit persists
after extended wash cycles using standard stain release tests. Generally,
these stain
release tests are based on soil re-deposition, and the release of corn oil and
mineral oil
from the fabric of the garment.
TEST METHODS
OIL REPELLENCY
Oil repellency ratings were determined according to Standard Test Method 118-
2002 of the American Association of Textile Chemists and Colorists (AATCC).
Oil
repellency was tested by placing drops of hydrocarbon liquids of varying
surface
tensions on the fabric, then visually determining the extent of surface
wetting. This test
determines how well finished fabrics resist oily stains and wetting by organic
liquids.
Generally, the higher the oil repellency rating, the better the finished
fabric's resistance
to staining by oily substances. The standard test liquids are listed in Table
2.
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Table 2. Standard Oil Repellency Test Liquids
Rating Hydrocarbon Surface Tension at 25 C
77 F d n/cm
1 Refined Mineral Oil 31.0
2 Refined Mineral Oil/n-Hexadecane 29.2
65/35 vol % at 21 C 70 F
3 N-Hexadecane 27.3
4 n-Tetradecane 26.2
n-Dodecane 24.6
6 n-Decane 23.6
Different types of wetting may be encountered, depending on the fabric's
finish,
fiber, or construction.' With many fabrics, the endpoint rating is obvious
because the
5 fabric will completely resist wetting by one test liquid, but will allow
immediate
penetration by the next liquid. With some fabrics, however, endpoint
determination can
be difficult. These fabrics will show progressive wetting by several test
liquids, as shown
by a partial darkening of the fabric at the liquid/fabric interface. On black
or dark fabrics,
wetting can be detected by a loss of ""sparkle" within the drop. For fabrics
where the
endpoint is difficult to determine, the endpoint is considered to be the test
liquid that
causes complete darkening at the interface within 30 seconds.
Fabric samples were placed face up on white blotting paper which rested on a
flat horizontal surface. Drops of standard test liquid, beginning with the
test liquid having
a rating of 1, were applied to the test fabric in five locations. Each drop
was
approximately 5 mm in diameter or 0.05 milliliters in volume. The drops were
observed
for 30 seconds from an approximate angle of 45 . If at least three of the five
drops were
not observed to wet or penetrate the fabric and did not show wicking around
the drops,
the test was repeated on an adjacent site using the test liquid having a
rating of 2. The
procedure was continued until at least three of the five drops wet or showed
wicking into
the fabric within 30 seconds. The fabric's AATCC oil repellency rating was
determined
to be the highest numbered liquid for which at least three of the five drops
did not wet or
wick into the fabric. Half point ratings may be given, for example 4.5 for a
borderline
pass on test liquid 5. An example of a borderline pass is where three or more
of the five
drops are rounded, however there is partial darkening of the specimen around
the edge
of the drop. In the United States, a commonly accepted level of oil repellency
is a rating
of S.
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STAIN RELEASE RATING
The AATCC stain release rating was determined according to Standard Test
Method 130-2000 of the American Association of Textile Chemists and Colorists
(AATCC). Fabric samples were placed flat on new AATCC Textile Blotting Paper
on a
smooth, horizontal surface. Five drops (0.2 milliliters total) of MAZOLAO Corn
Oil (ACH
Food Companies Inc.) were placed on the fabric surface creating one single
spot. A
sheet of glassine paper was placed over the oil puddle, and a 2.27 kg (5 Ib)
weight was
then placed directly over the glassine paper for 60 seconds. The weight and
the
glassine paper were removed, and the fabric sample was then washed for 12
minutes on
normal wash cycle with high water level in a KENMOREO automatic using 100
grams of
AATCC 1993 Standard Reference Detergent WOB. Wash temperature was 60 C, rinse
temperature was cold. The total weight of the load was 4 lbs. After the final
spin cycle,
the entire load was placed in a KENMOREO automatic dryer and dried on high for
45-50
minutes.
Stain release ratings were determined by placing the stained,-washed, and
dried
fabric fiat in the center of a non-glare blacktop table with one edge of the
table touching
a Stain Release Replica (order number 08379, available from the AATCC). The
fabric
was viewed from a distance of approximately 76 cm (30 inches) and the residual
stain
was compared to the Stain Release Replica to the nearest 0.5 rating. Ratings
are given
from 1 (minimum) to 5 (maximum). In the United States, a commonly accepted
level of
stain release is a rating of 3.
WICKING TEST METHOD
The moisture wicking of the yarns of the invention is determined by known
methods, such as by a vertical wicking test or a horizontal wicking test. The
vertical
wicking test may be conducted by knitting the yarns into tubes, and then
either scouring
or treating the tubes with any desired agent and allowing the treated tubes to
air dry.
The tubes are then cut into 1 inch (25.4) wide strips about 8 inches (203 mm)
long and
suspended vertically above water with 3 inches (75 mm) in the water and 5
inches (125
mm) above the water. Observations of the height of the water being wicked up
the strips
are conducted visually at predetermined times, such as at 1 minute, 5 minutes,
10
minutes, 20 minutes and 30 minutes.
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INDIVIDUAL FLUORINE PERCENT ON WEIGHT OF FABRIC
The percent on weight of fabric for fluorine, represented as % OwfF, is
determined
as follows. Fluorine on the fabric, represented here as FFAB, is measured by
the well-
known Wickbold torch method in parts per million (ppm). This value is then
divided by
the weight percent of fluorine in the fluorochemical, represented as FFC, to
obtain the
fluorine percent on weight of fabric for that fluorochemical:
% OWfF = FFAB / FFC
When more than one fluorochemical is used, the total fluorine percent on
weight of fabric
is obtained by summing the individual fluorine percent on weight of fabric
values for all
fluorochemicals used.
SOIL RE-DEPOSITION WASHING
Using a "Lab-Line" extraction mixer, prepare a 1% or 2% dispersed solution of
DuPont Standard Dry Soil in 1 liter (L) of room temperature de-ionized (DI)
water. Cut
fabric samples 75 mm by 75 mm (3" by 3"). Add soil solution to separatory
funnel and
place fabric samples in funnel, up to 6 samples per funnel. Agitate for 15
minutes at a
setting of 20 cycles per minute. Drain soil solution into a 1 L beaker and
discard. Rinse
funnel with deionized (DI) water to remove residual soil on sides of funnel
and drain.
Add 1 L of 40 C DI water to separatory funnel. Add 2.1 grams of TIDE Free
powder
detergent. Agitate for 15 minutes at speed setting of 20 cycles per minute.
Drain wash
water into a 1 L beaker and discard. Add 1 L of 40 C DI water to the funnel
and agitate
for 10 minutes at speed setting of 20 cycles per minute. Drain rinse water and
discard.
Add 1 L of room temperature DI water and agitate for 10 minutes at speed
setting of 20
cycles per minute. Drain rinse water and discard.' Remove samples and squeeze
to
remove excess water. Air dry for a minimum of 8 hours or until dry. Rate
samples
according to the Gray Scale, AATCC Evaluation Procedure 2.
Procedure for dispersing "dry soil" in water. The dispersed DuPont Soil
Solution
was made using a Research Model 01 Szegvari Attritor System. An 80% water/20%
DuPont Dry Soil solution was made. The procedure uses 2 lbs. of 2 mm zirconium
siiicate grinding media at an operating pressure of 40 psi and a shaft speed
of 600 rpm
for two hours.
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DuPont Standard Dry Soil**
Component CAS Number wt%
Peat Moss - 38
Cement 65997-15-1 17
Kaolin Clay, Peerless 1318-74-7 17
Amorphous Silica 7631-86-9 17
Mineral Oil 8012-95-1 8.75
Carbon Black 1.75
Red Iron Oxide 1309-37-1 0.50
**DuPont Standard Dry Soil may be purchased from Textile Innovators
Corporation, 101 Forest St., Windsor, NC 27983, USA (252-794-9703)-synthetic
soil prepared according to AATCC method for carpet soil tests.
EXAMPLES
In an example of the invention sock samples were knitted using the following
construction details: 80% COOLMAXO (Type 729W) and 20% plating yarn consisting
of
120 denier LYCRAO (902C) double covered with 70 denier 34 filament nylon 66
plus 40
denier 13 filament nylon 66 in the sock top, and 18 denier LYCRAO air jet
covered with 2
plies of 70 denier 68 filament nylon 66 in the foot of the sock.
In an comparative example, sock samples were knitted using the following
construction details: 63% COOLMAXO (Type 729W) in a 50/50 cotton blend and 37%
plating yarns of 18 denier LYCRAO spandex air jet covered with 2 plies of with
2 plies of
70 denier 68 filament nylon 66 filament yarn.
All invention example socks were finished according to the following protocol:
first a pre-scour for 15 minutes at 70 C with 0.5 gram/liter Merol HCS (from
Stepan CO,
22 West Frontage Road, Northfield, Illinois 60063); 0.5 g/I trisodium
phosphate and 0.5
g/I Lubit 64 (Lanxess Corp. 111 RIDC Park West, Pittsburgh, Pennsylvania);
next a
water rinse (2 times); add water to 40/1 liquor ratio; add ZONYLO SRM based on
a
minimum of 5% (up to 10%) by weight of goods (garment weight); adjust pH to
5.5 with
acetic acid; heat the bath to 43 C and hold 20 minutes with agitation; drop
bath; do not
rinse garments and then tumble dry. Using standard boarding techniques the
garments
are individually boarded at 160 C for between 90 seconds to assure product
cure on the
garment.
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All comparative example socks were finished according to the following
protocol:
first a pre-scour for 15 minutes at 70 C with 0.5 gram/liter Merol HCS, 0.5
g/I trisodium
phosphate and 0.5 g/I Lubit 64; add PERMALOSETM 3%; adjust pH to 6.0 with
acetic
acid; heat the bath to 60 C and hold 10 minutes with agitation; drop bath; do
not rinse
garments and then tumble dry. Using standard boarding techniques the garments
are
individually boarded at 140 C for 60 seconds.
Both comparative and invention example socks met the moisture wicking
specifications for vertical rise of water, at least 75 mm.
The soiling ratings are given in the following tables 1 and 2. The Gray Scale
ratings indicate relative "dinginess" of a white sock. In both cases where the
invention
examples were treated with ZONYLO SRM and challenged with a soil test of
either 1%
or 2% soiling, the invention examples were superior to the comparative
examples.
Table 1.
Using a 1% DuPont Soil Solution:
80% COOLMAXO socks Gray Scale Rating
Comparative Example 3.5
Treated with 5% ZONYLO SRM 4.5
Treated with 10% ZONYLO SRM 4.5
Table 2.
Using a 2% DuPont Soil Solution:
80% COOLMAXO socks Gray Scale Rating
Comparative Example 3.5
Treated with 5% ZONYLO SRM 4.5
Treated with 10% ZONYLO SRM 4.5
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