Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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TITLE
METHOD FOR MAKING A CARPET HAVING A COATED SECONDARY BACKING
R~CK~ROUND QF T~ lNv~NllON
Cross-Re~erence to Related Applica~ions
This application is a continuation-in-part of
U.S. Patent Application Serial No. 08/373,997, filed
January 18, 1995, now abandoned.
Field of the Invention
This invention relates to a method for making a
carpet having a primary backing which is permeable to
liquids and a secondary backing which is substantially
impervious to liquids. The method involves applying a
continuous coating of hydrophobic polymeric latex to the
outer surface of a secondary backing material. The
hydrophobic polymeric latex may be a modified latex
containing fluorochemicals or repellent finishes dispersed
therein. The invention also encompasses carpets made from
such a method.
Description of Related Art
The majority of residential and commercial
carpets are constructed in the following general manner.
Carpet pile yarn is first inserted through a primary
backing fabric to form tufts of yarn projecting from the
surface of the fabric. The carpet is then dyed. The
primary backing is then coated with an adhesive latex to
lock the yarn tufts in place and to provide an adhesive
for a secondary backing fabric. The latex-coated primary
backing is then bonded to the secondary backing to form a
laminated backing structure.
However, one problem with the above-described
carpets is their susceptibility to penetration by liquids.
For instance, if water, a water-based liquid (soda pop,
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coffee, urine, etc.), or another type of llquid (e.g.,
oil-based) ls spllled on the carpet face, lt may permeate
through the prlmary and secondary backings and onto the
underlying material (carpet underpad, hardwood floors,
etc.). The underlylng materlal may become stalned and
deterlorate over a period of time. Mlldew may also grow
on the backing and underlylng materlal.
Those skilled ln the trade have consldered
dlfferent ways for manufacturlng carpets ln order to
reduce the permeabillty of llquids through the primary
backing material.
One method involves applying a fluorochemical or
other water-repellent agent onto the face fiber of the
carpet during the fiber-forming or carpet-manufacturing
process. In such instances, the fluorochemicals serve to
reduce the wettability of the fibers in the finished
carpet such that a spilled liquid will initially "bead" on
the surface of the fiber. However, if the beaded liquid
is not promptly removed, lt wlll eventually be absorbed by
the fibers and may penetrate through the primary backing.
Another method for making the primary backing
impervious to liquids involves mixing fluorochemicals into
a polymeric latex composltion. This latex composition is
used to encapsulate the yarn tufts and as an adhesive
between the prlmary and secondary backings. The underside
of the primary backing is coated with this fluorochemical-
containing latex.
For instance, Ucci, US Patent 4,643,930,
Blyth et al., US Patent 4,619,853, and Ucci, US Patent
4,579,762 each disclose a carpet structure having a
primary backing tufted with nylon yarns. The underslde of
the primary backing ls coated wlth a polymeric latex
containing fluorochemicals mixed thereln such that the
primary backing is made substantially impervious to water.
As descrlbed ln Vinod, US Patent 5,348,785, it
ls also known to make carpets havlng a secondary backlng
which is substantially impervious to aqueous solutions.
This process involves applying a fluorochemical solution
to the underside of a secondary backing and then drying
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the fluorochemical solution. However, it would be
desirable to have a process where the fluorochemical
solution could be applled to the secondary backing in a
more effective and economically feasible manner. The
present invention provides such a process.
GB 1 409 068 describes a process, where a
secondary backing is applied to a tufted primary by laying
the secondary backing material on the primary backing and
then applying foam to the outer surface of the secondary
backing such that latex penetrates into and through the
secondary backing to encapsulate the tufts of the primary
backing. The patent further discloses that sufficient
latex re~l n .s around the outer surface of the constituent
yarns of the secondary backing to effect a degree of
encapsulation of such yarns and to provide adequate
adhesion of the secondary backing.
It has now been found that the secondary backing
of a carpet may be rendered impermeable to liquids by
applying a continuous coating of hydrophobic polymeric
latex to the outer surface of the secondary backing. The
hydrophobic polymeric latex may be a modified latex
containing fluorochemicals or repellent finishes dispersed
therein. The present invention provides a carpet having a
primary backing which is permeable to liquids and a
secondary backing which is substantially impervious to
liquids.
STnUM~Ry OF T~ lNv~NllON
This invention is directed to a method for
constructing a carpet having a primary backing which is
permeable to liquids and a secondary backing which is
substantially impervious to liquids. This method involves
applying an adhesive to the underside of a tufted primary
backing in order to lock the tufts into place.
Preferably, the adhesive is an adhesive latex. A
secondary backing is then adhered to the adhesive
latex-coated primary backing. A continuous coating of
hydrophobic polymeric latex is then applied to the outer
surface of the secondary backing. This latex coating may
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be applied by various means including foam, spray, or
padding methods. ThiS hydrophobic latex coating may be a
modified latex containing fluorochemicals mixed therein.
The modified latex may contain repellent finishes in
addition to or in place of the fluorochemicals. The
hydrophobic latex coating is applied to the secondary
backing in an amount sufficient to render the secondary
backing substantially impervious to liquids. The
constructed carpet including the hydrophobic latex coating
is then dried for a sufficient amount of time to render
the secondary backing substantially impervious. The
carpet may be dried by passing it through an oven at an
oven temperature in the range of 250~ to 400~F.
Alternatively, the carpet may be dried at room
temperature. Preferably, the primary and secondary
backing are polypropylene materials and the primary
backing is tufted with nylon yarn. The hydrophobic
polymeric latex coating may also be applied to the
underside of a finished carpet to render the secondary
backing substantially impervious to liquids. This
invention also includes carpets produced from the above-
described methods.
BRIEF DESCRIPTION OF THE FIGURES
Figure 1 is a schematic view of a method of the
present invention illustrating the foam application of a
hydrophobic latex coating to the outer surface of a
secondary backing.
Figure 2-A is an enlarged view of the foam
system shown in Figure 1.
Figure 2-B is an enlarged view of the foam
system shown in Figure 1 illustrating the foam delivery
tube extending over the lower press roll.
D~TATT~n D~.~CRIPTION OF T~ LNV~:Nl~ON
The present invention provides a process for
constructing a carpet having a primary backing which is
permeable to liquids and a secondary backing which is
substantially impervious to liquids. A continuous coating
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of "hydrophobic polymeric latex" is applied to the outer
surface of the secondary backing in a sufficient amount to
render the secondary backing of the carpet "substantially
impervious" to liquids.
By the term "hydrophobic polymeric latex" as
used herein, it is meant a hydrophobic, film-forming,
synthetic latex in the form of an emulsion and made from
such materials as, for example, carboxylated acrylate
polymer, carboxylated styrene/acrylate copolymers,
carboxylated vinylidiene chloride/butadiene copolymers,
carboxylated styrene/butadiene, ethylene/vinyl acetate
copolymers, polyacrylates, acrylates, polychloroprene, and
elastomers as well as blends of the foregoing materials.
Generally, the hydrophobic polymeric latex formulation
should contain about 20~ to about 80~ by weight of a latex
polymer as described above. Preferably, the hydrophobic
latex coating consists essentially of a latex polymer
selected from the above polymers. However, it should be
recognized that the amount of latex polymer active
ingredient in a given formulation will be adjusted
depending on the desired viscosity, fabric coverage,
coating rate, and other process specifications.
The hydrophobic latex formulation may also
include a minor amount of fillers, such as calcium
carbonate, silica, talc, or clay. Generally, the amount
of such fillers dispersed in the latex should be in the
range of about 0~ to about 50~ and preferably in the range
of about 0~ to about 10~ by weight of latex.
Additionally, the hydrophobic polymeric latex may include
a thickening agent such as various organic or inorganic
gums, wetting agents, foaming agents, colorants,
antimicrobials and other additives in minor amounts.
By the phrase, "substantially impervious to
liquids" as used herein, it is meant that water, aqueous
solutions (e.g., coffee, wine, soda, or fruit juice), or
non-aqueous solutions (e.g., mineral oil or alcohol) will
not substantially penetrate through the secondary backing
in accordance with the testing methods described below.
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Generally, the pile yarns for the carpets of
this invention may be prepared by conventional techniques.
These yarns are composed of multiple filaments which are
formed from synthetic or natural polymers, such as wool.
Typical synthetic fiber-forming polymers include, for
example, polyolefins such as polypropylene, polyamides
such as polyhexamethylene adipamide (nylon 6,6) and
polycaprolactam (nylon 6), polyesters such as polyethylene
terephthalate, and acrylics. Copolymers, terpolymers, and
melt blends of such polymers are also suitable.
In a nylon-filament forming process, the molten
polymer is extruded through a spinneret into a quenching
medium, where the polymer cools and solidifies to form
filaments. After drawing, the filaments may be crimped
and cut into short lengths to make staple fiber, or bulked
to make bulked continuous filaments (BCF). A
fluorochemical finish may be applied during the fiber-
forming process (producer-applied fluorochemical).
After additional yarn processing steps, the BCF
or staple spun yarns may then be tufted into a primary
backing fabric by techniques known in the trade.
Alternatively, the carpets can be woven or needle-punched.
The primary backing may be a woven material made from
natural or synthetic materials, such as, jute, wool,
rayon, polyamides, polyesters, or polyolefins. Nonwoven
backings may also be used. The carpet is then typically
dyed, rinsed, and subjected to other standard finishing
operations including stain-resist and soil-resist
treatment of the yarn tufts.
An "adhesive latex" is then applied to the
underside of the primary backing fabric to lock the tufts
in place and to provide an adhesive for a secondary
backing material. By the term "adhesive latex" as used
herein, it is meant a water emulsion of synthetic rubber,
natural rubber, or other polymer, such as, for example,
styrene/butadiene copolymers, ethylene/vinyl acetate
copolymers, polyacrylates, and blends thereof. The
adhesive latex typically includes a high concentration of
filler material such as calcium carbonate, silica, talc,
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or clay. However, in this invention, it is important that
the adhesive latex not contain any additives which would
render the primary backing impermeable to liquids. The
primary carpet backings of this invention are permeable to
liquids. Any liquids which spill onto the carpet should
not excessively spread across the face fiber but should
penetrate through the primary backing. Generally, the
amount of adhesive latex applied to the primary backing is
in the range of about 18 to 40 ounces per square yard of
primary backing fabric. Alternatively, the primary
backing may be coated with a hot melt adhesive as
described in Reith, US Patent Nos. 4,844,765 and
4,939,036.
The adhesive latex-coated tufted primary backing
is then brought in contact with a secondary backing
material having an "inner surface" and "outer surface~'.
By the term, "inner surface", it is meant the surface of
the secondary backing material which is in contact with
the underside of the primary backing material. By the
term, "outer surface", it is meant the surface of the
secondary backing material opposing the inner surface of
the primary backing material. Different secondary backing
materials known in the trade may be used including jute,
woven tapes of polypropylene, plain woven polypropylene
fabrics, felts, and thermoplastic polymer films. Often,
the inner surface of the secondary backing wlll also be
coated with a small amount of latex to improve the
adhesiveness between the latex-coated underside of the
primary backing and the secondary backing. This adhesive
latex also should not contain any additives which would
render the primary backing impermeable to liquids.
Referring to Figure 1, the contacted primary (1) and
secondary (2) backings adhere to each other as the
backings pass over the marriage roll (4).
After the primary and secondary backings have
been brought into contact with each other, a continuous
coating of hydrophobic polymeric latex is then applied to
the outer surface of the secondary backing material.
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In order to make the hydrophobic polymeric latex
formulation more effective in reducing liquid permeability
through the secondary backing, the latex formulation may
contain fluorochemicals and/or other repellent finishes
dispersed therein. However, as shown in the Examples
below, it is not necessary to add fluorochemicals and/or
other repellent finishes to the latex. If used, the
amount of fluorochemicals or repellent finishes dispersed
in the latex formulation is generally about 1~ to about
10~ by weight based on weight of latex. This upper limit
of 10~ is due to cost considerations. Amoun~s greater
than 10~ may be used but may not be economically feasible
depending on the costs of the fluorochemicals or
repellents.
Suitable fluorochemicals which may be dispersed
in the hydrophobic polymeric latex formulation used for
coating the outer surface of the secondary backing
include, but are not limited to, polymers or compounds
with molecular weights of greater than 500 having pendent
or end groups of perfluoroalkyl moieties. Examples of
some suitable fluorochemicals include polyvinyldiene
fluoride, polytetrafluoroethylene, 2-perfluorooctylethyl
acrylate and blends of such compounds with polymers of
methyl methacrylate, butyl methacrylate, and ethyl methyl
acrylate, and modified wax emulsions, and polyvinylidene
chloride. Commercially available fluorochemicals such as
"TEFLON", "DURATECH", and "ZONYL" from DuPont Co.,
"MILEASE" from ICI, "ASAHIGARD" from Asahi, "SCOTCHGARD"
from 3M, "SOFTECH" from Dyetech, "TEX-TEL" from Atochem,
and "NK GUARD" from Nicca, may be used. These commercial
fluorochemicals are typically available as dispersions,
where the fluorochemicals are dispersed in water and these
dispersions are commonly referred to as fluorochemical
solutions. The fluorochemical solutions may be mixed with
the latex polymer to form a modified hydrophobic latex.
It is also recognized that the hydrophobic
polymeric latex formulation may contain a "repellent
finish" in addition to the fluorochemicals or in lieu of
the fluorochemicals. By the term "repellent finish" as
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used herein, it is meant a finish comprising repellent
chemicals such as silicone-based compositions, wax
- emulsions, and naturally occurring oils, (or mixtures
thereof) dispersed, suspended, or dissolved in a solvent
such as water or alcohol. The finish may also contain
surfactants, foaming agents, and other additives. These
repellent finishes may be mixed with the latex polymer to
form a modified hydrophobic latex.
The hydrophobic latex coating may be applied to
lo the outer surface of the secondary backing by various
means, including foaming, spraying, or padding methods.
Figure 1 illustrates a foam system for applying the latex
in the form of foam to the outer surface of the secondary
backing against the force of gravity. After the foam has
been applied, the primary and secondary backing materials
are passed between upper (5) and lower (6) press rolls,
whereby the primary and secondary backing materials are
pressed together and laminated.
The entire carpet structure is then subjected to
heat-treatment in order that the latex adhesive between
the primary and secondary backings may be dried and the
hydrophobic latex coating on the outer surface of the
secondary backing may be dried. Typically, the carpet
structure will be positioned on a tenter frame and passed
through a conventional latex curing oven (7). Although the
heating temperature may vary depending upon the type of
pile yarn, latex compositions, repellent finish, and
backing materials used, the temperature inside the oven
should generally be in the range of 250~ to 400~F.
Alternatively, the carpet structure may be dried at room
temperature. In either event, it is important that the
carpet structure and hydrophobic latex coating be dried
for a sufficient amount of time in order that the
secondary backing is rendered substantially impermeable.
~ 35 It has also been found that a continuous coating
of hydrophobic polymeric latex may be applied to the
underside of a "finished carpet" to render the secondary
backing substantially impervious. This latex coating may
also contain fluorochemicals dispersed therein. By the
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term, "finlshed carpet" as used herein, it is meant a
carpet having a primary backing with tufts of yarn
projecting therefrom which is permeable to liquids and
which is adhered to a secondary backing material by an
adhesive which has dried.
The methods and resultant carpets of this
invention offer advantages over carpets of the prior art.
In contrast to many carpets having a tufted primary
backing which has been coated on its underside with a
fluorochemical-containing adhesive latex, the delamination
strength and tuftbind of the carpets in this invention are
not reduced. As described above, in carpets having a
tufted primary backing which has been coated with a
fluorochemical-containing adhesive latex, there is often
reduced adhesion between the primary and secondary
backings due to the pre-mixing of the fluorochemicals into
the adhesive latex.
In a preferred embodiment, the hydrophobic latex
coating is applied to the outer surface of the secondary
backing by a foam applicator (8) subsequent to the primary
and secondary backings passing over the marriage roll (4)
and prior to the backings passing between the upper and
lower press rolls (5,6). In such a method, a foamable
latex containing foaming agents is first prepared.
Suitable foaming agents include KAF 300S, available from
Peach State Labs, Dextrol Foamer 916, available from
Dexter Chemicals, Inc., Mykon NRW3 available from Sequa,
Arquad 12-50 or Arquad 12-37 available from Akzo
Chemicals, and Stanfax 238, available from Standard
Adhesives. As discussed above, the foamable latex may
also contain fluorochemicals.
The foamable latex can then be generated into
foam and applied through a commercial foam generator. It
is important that the foam be stable in order that it may
be applied uniformly along the secondary backing. The
latex should be applied as a continuous coating. The foam
application conditions may be adjusted to obtain the
desired percentage of fiuorochemicals in the foamable
mixture, flow rate of the foamable mixture, speed of the
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carpet through the oven (dryer speed), and blow ratio
(ratio of the volume of air to the volume of foamable
mixture).
As shown in Figure l, one method of foam
application involves feeding the carpet (1) on a moving
carpet line in such a manner that the face of the carpet,
i.e,, the pile, is directed upwards and the secondary
backing rests on the carpet line, i.e., the tenter frame.
The carpet line is located above a rotating lower press
roll (6), and the foam system (8) includes a foam manifold
connected to a foam generator. Referring to Figure 2-A,
the foam is introduced from the manifold (11) through a
foam delivery tube (12) to form a bank of foam in the nip
area between the carpet and rotating lower press roll (6).
This bank of foam is formed in the triangular-like area
marked as (A) in Figure 2-A, and the foam is applied to
the secondary backing by means of the rotating lower press
roll and the moving carpet. The foam is effectively
applied, because it collapses at the nip point between the
lower press roll and secondary backing. A nip slide or
dam device (13) may be installed to hold excess foam near
the lower press roll, until the foam is picked-up and
nipped onto the secondary backing by rotation of the roll
through the foam puddle.
The position of the foam delivery tube (12) and
the nip slide device (13) in relation to the lower press
roll (6) is important. First, the delivery tube should be
positioned so that foam is delivered onto the upper sector
of the press roll (6), as shown in Figure 2-A, in order
that the foam can be more uniformly nipped onto the
secondary backing and that any excess foam will slide
downwards along the roll to be collected by the nip slide
(13). This is accomplished by having the outlet of the
delivery tube extend over the lower press roll as shown in
Figure 2-B. The diameter of the lower press roll is
generally in the range of about 6 to 18 inches, and the
distance from the outlet of the delivery tube to the press
roll should be in the range of about 1/4th to 3 inches.
Secondly, the delivery tube (12) should be positioned so
11
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that there is no contact between the tube and the carpet.
Thus, the delivery tube may be angled downwards as shown
in Figure 2-B. The angle of the delivery tube (to the
horizontal) may nominally be in the range of about lO to
25 degrees. Also, the height of the manifold (ll) should
be adjusted so that there is no contact between the
manifold and the carpet. Thirdly, the nip slide (13)
should be positioned so that it will collect any excess
foam which falls downward along the upper sector of the
press roll (6). Thus, one end of the nip slide (13) is
located at about the midpoint of the press roll (6), i.e.
the 3:00 position on the face of press roll as shown in
Figure 2-A. The other end of the nip slide (13) is
positioned under the inlet portion of the delivery tube
(12). Referring to Figure 2-B, the angle of the nip slide
(to the horizontal) may nominally be in the range of about
5 to 45 degrees. As shown in Figure 2-B, the length (L)
of an individual delivery tube should slightly exceed the
width (W) of the nip slide in order for the foam to be
delivered onto the lower press roll (6). It is recognized
that there will be multiple foam delivery tubes in order
to uniformly treat the secondary backing. For example,
there may be 16 delivery tubes per carpet line for
treating carpets having 12 foot widths.
The speed of the rotating lower press roll (6)
and the carpet line may be the same or different. The
lower press roll can run in the same direction as the
carpet or in the reverse direction of the carpet.
Typically, the speed of the carpet line is in the range of
20 to 200 feet per minute, and the speed of the nip roll
is in the range of 50~ to 200~ of the speed of the carpet
line (reverse direction) or 50~ to 300~ (same direction).
In cases where a "non-modified hydrophobic latex
coating" (i.e., a latex formulation which does not contain
fluorochemicals and/or other repellent finishes) is
applied to the outer surface of the secondary backing, the
amount of latex applied is typically in the range of about
l to about lO ounces pe~ square yard of secondary backing
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and is preferably in the range of about 2 to about 4
ounces per square yard.
In cases where a "modified hydrophobic latex
coating" (i.e., a latex formulation which contains
fluorochemicals and/or other repellent finishes) is
applied to the outer surface of the secondary backing, the
amount of latex applied is typically in the range of about
l to about 5 ounces per square yard of secondary backing
and is preferably in the range of about l to about 3
ounces per square yard.
Typically, commercially available repellent
finishes, including fluorochemical solutions, contain
about 0.5 to about 40~ by weight total active ingredient.
In the case of silicones, the amount of the total active
ingredient may be greater than 40~ by weight. In this
invention for modified hydrophobic latex coatings, the
amount of fluorochemical or other repellent active
ingredient applied will be generally in the range of about
O.Ol to about 5.00 ounces per square yard of secondary
backing, and approximately the same amounts may be applied
in either foam or spray application. Preferably, about
0.05 to about 3.00 ounces of fluorochemical or other
repellent active ingredient per square yard of secondary
backing is applied. However, it is understood that the
amount of fluorochemical/repellent active ingredient
applied will be adjusted depending upon the type and
concentration of the repellent, amount of fluorochemical
(soil resist agent) on the face fiber, carpet
construction, density of carpet face fiber, type of carpet
face fiber, tightness or closeness of the secondary
backing (woven or non-woven), and the amount and type of
latex used. In any event, it is important that a
sufficient amount of hydrophobic polymeric latex be
uniformly applied to the outer surface of the secondary
~ 35 backing in order that the secondary backing is rendered
impervious to liquids in accordance with the Staining Test
as described under "Testing Methods" below. As discussed
above, the latex may be a non-modified hydrophobic latex
or a modified hydrophobic latex.
13
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The present invention is further illustrated by
the following examples, but these examples should not be
considered as limiting the scope of the lnvention.
Testing Methods -~
S~ ~ n; n~ Test:
Mix 45 grams of a cherry flavored, sugar
sweetened, Kool-Aid powder in 500 ml of water. Allow
solution to reach room temperature (75 +/- 5~F) before
using. Place the carpet sample with the secondary backing
touching a white absorbent paper towel or blotter paper.
Pour 20 ml of Kool-Aid onto the carpet sample from the
face fiber side through a l-l/2" diameter cylinder from a
height of about 6 cm. to create a circular stain. Remove
cylinder and mechanically work the solution into the
tufts, e.g., by hand, in order to obtain uniform staining.
Let the sample stay undisturbed for 30 minutes. Lift the
sample at the end of 30 minutes and look for visual red
staining on the white absorbent paper. Room temperature
water can be substituted for the Kool-Aid soiution as a
staining liquid. If considerable amount of a staining
solution has passed through the carpet sample, a severe
staining will be visible. The sample will be termed as
substantially impervious if none or a very slight amount
of liquid has passed through the carpet sample leaving
none or a few visible drops of staining on a white
absorbent towel or blotter paper.
MPT.li!.C
~xample l
A residential cut pile carpet sample (about 5/8"
pile height; 33 oz./yd2 weight) was produced by a
conventional mill process. The pile surface of the carpet
was treated with topical stain resist and fluorochemical
agents according to standard mill procedures. The carpet
was composed of nylon 6,6 BCF face fiber, a woven
polypropylene primary backing, an adhesive latex and a
woven polypropylene secondary backing. The adhesive latex
was composed of a mixture of a carboxylated styrene
14
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butadiene rubber, calcium carbonate, water, a thickening
agent and a foaming agent. Approximately 28-30 oz/yd2 of
this foamed adhesive latex was applied to the primary
backing, and the primary and secondary backings were
adhered together.
Prior to the latex curing oven, the outer surface
of the secondary backing was treated with a foam
application of about 2 ounces per square yard of the
following specially formulated modified latex:
~ 3 parts of a carboxylated acrylate latex polymer
(38-45~ active ingredient), available from Dow Chemicals,
Midland, MI as XUR 1540-1156-1 experimental latex diluted
with 1 part water, by weight,
~ 5~ by weight of an aqueous solution ~Zonyl" 1250
fluorochemical solution (15-20~ active ingredient),
available from the DuPont Company, based on the weight of
the latex polymer, and
~ 10 grams/liter of a foaming agent, KAF 300S,
available from PeachState Labs, based on the total mixture
of latex polymer, "Zonyl" 1250 fluorochemical solution,
and water.
The treated carpet sample was then passed through
a latex curing oven at an oven temperature of 350~ to
400~F and the latex was dried. The carpet sample was then
cooled to room temperature before being subjected to the
Staining Test.
A sample from the treated carpet was placed on
blotter paper and was stained with Kool-Aid as described
in the above Staining Test under "Testing Methods". The
carpet sample was substantially impervious to the Kool-Aid
stain.
Another sample from the treated carpet was placed
on blotter paper and was stained as described in the
Staining Test with the exception that hot coffee (150~F)
~ 35 was substituted for Kool-Aid as the staining agent. The
carpet sample was substantially impervious to the hot
coffee stain.
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Comparative ~xample A
A carpet sample was prepared as described in
above Example 1, except the outer surface of the secondary
backing was not treated with a coating of modified latex
or a coating of non-modified latex. A sample from the
untreated carpet was placed on blotter paper and was
stained with Kool-Aid as described in the Staining Test.
The blotter paper was severely stained by the Kool-Aid.
Another sample from the untreated carpet was
placed on blotter paper and was stained as described in
the Staining Test with the exception that hot coffee
(150~F) was substituted for Kool-Aid as the staining
agent. The blotter paper was severely stained by the
coffee stain.
Comparative ~xample B
In this comparative example, the woven
polypropylene secondary backing was removed from the
treated carpet in Example 1 to provide a carpet having a
tufted primary backing with a coating of adhesive latex on
its underside. A sample from this carpet was placed on
blotter paper and was stained with Kool-Aid as described
in the Staining Test. The blotter paper was severely
stained by the Kool-Aid, indicating that treating the
outer surface of the secondary backing with the modified
latex coating was not sufficient to render the primary
backing impermeable in accordance with the Staining Test.
~xample 2
A residential cut carpet sample pile (about 5/8"
pile height; 33 oz/yd2 weight) was produced by a
conventional mill process. The pile surface of the carpet
was ~reated with topical stain resist and fluorochemical
agents according to standard mill procedures. The carpet
was composed of nylon 6,6 BCF face fiber, a woven
polypropylene primary backing, an adhesive latex and a
woven polypropylene secondary backing. The adhesive latex
was composed of a mixture of a carboxylated styrene
butadiene rubber, calcium carbonate, water, a thickening
agent and a foaming agent. Approximately 28-30 oz/yd2 of
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this foamed adhesive latex was applied to the primary
backing, and the primary and secondary backings were
a~dhered together.
Prior to the latex curing oven, the outer
surface of the secondary backing was treated with a foam
application of about 2 ounces per square yard of the
following specially formulated modified latex:
~ 3 parts of a carboxylated vinylidene
chlorlde/butadiene latex polymer (45-52~ active
ingredient), available from Dow Chemicals, Midland, MI as
XUR 1540-1157-1 experimental latex diluted with 1 part
water, by weight,
~ 5~ by weight of an aqueous solution of "Zonyl"
1250 fluorochemical solution, available from the DuPont
Company, based on the weight of the latex polymer, and
~ 10 grams/liter of a foaming agent, KAF 300S,
available from PeachState Labs, based on the total mixture
of latex polymer, "Zonyl" 1250 fluorochemical solution,
and water.
The treated carpet sample was then passed
through a latex curing oven at an oven temperature of 350~
to 400 ~F and the latex was dried. The carpet sample was
then cooled to room temperature before being subjected to
the Staining Test.
A sample from the treated carpet was placed on
blotter paper and was stained with Kool-Aid as described
in the Staining Test. The carpet sample was substantially
impervious to the Kool-Aid stain.
Another sample from the treated carpet was
placed on blotter paper and was stained as described in
the Staining Test with the exception that hot coffee
(150~F) was substituted for Kool-Aid as the staining
agent. The carpet sample was substantially impervious to
the hot coffee stain.
Comparative ~x~mple C
A carpet sample was prepared as described in
above Example 2, except ' he outer surface of the secondary
backing was not treated with a modified or a non-modified
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WO96/22414 PCT~S96/00329
latex. A sample from the untreated carpet was placed on
blotter paper and was stained with Kool-Aid as described
in the Staining Test. The blotter paper was severely
stained by the Kool-Aid.
Another sample from the untreated carpet was
placed on blotter paper and was stained as described in
the Staining Test with the exception that hot coffee
(150~F) was substituted for Kool-Aid as the staining
agent. The blotter paper was severely stained by the
coffee stain.
Comparative ~xample D
In this comparative example, the woven
polypropylene secondary backing was removed from the
treated carpet in Example 2 to provide a carpet having a
tufted primary backing with a coating of adhesive latex on
its underside. A sample from this carpet was placed on
blotter paper and was stained with Kool-Aid as described
in the Staining Test. The blotter paper was severely
stained by the Kool-Aid, indicating that treating the
outer surface of the secondary backing with the modified
latex was not sufficient to render the primary backing
impermeable in accordance with the Staining Test.
Example 3
Two residential cut pile carpet samples (about
5/8" pile height; 33 oz/yd2 weight) were produced by a
conventional mill process. The pile surface of the carpet
was treated with topical stain resist and fluorochemical
agents according to standard mill procedures. The carpet
samples were composed of nylon 6,6 BCF face fiber, a woven
polypropylene primary backing, an adhesive latex and a
woven polypropylene secondary backing. The adhesive latex
was composed of a mixture of a carboxylated styrene
butadiene rubber, calcium carbonate, water, a thickening
agent and a foaming agent. Approximately 28-30 oz/yd2 Of
this foamed adhesive latex was applied to the primary
backing, and the primary and secondary backings were
adhered together. The carpet samples was then passed
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through a latex curing oven at an oven ~emperature of 350
to 400~F and the latex was dried to form two finished
carpet samples.
The underside of both finished carpet samples were
sprayed with about 3 ounces per square yard of the
following non-modified latex formulation:
~ a carboxylated acrylate latex polymer (38-45~
active ingredient), available from Dow Chemicals, Midland,
MI as XUR 1540-1156-1 experimental latex.
Both carpet samples (Sample A and Sample B) were
then dried in an oven at an oven temperature of 250~F for
20 minutes. The samples were then cooled to room
temperature before being subjected to the following tests.
Sample A was placed on blotter paper and was
stained with Kool-Aid as described in the Staining Test.
The carpet sample was substantially impervious to the
Kool-Aid stain.
Sample B was placed on blotter paper and was
stained as described in the Staining Test with the
exception that hot coffee (150~F) was substituted for
Kool-Aid as the staining agent. The blotter paper was
visibly stained with co~fee.
Ex~le 4
A residential cut pile carpet sample (about 5/8"
pile height; 33 oz/yd2) was produced by a conventional
mill process. The pile surface of the carpet was treated
with topical stain resist and fluorochemical agents
according to standard mill procedures. The carpet was
composed of nylon 6,6 BCF face fiber, a woven
polypropylene primary backing, an adhesive latex and a
woven polypropylene secondary backing. The adhesive latex
was composed of a mixture of a carboxylated styrene
butadiene rubber, calcium carbonate, water, a thickening
agent and a foaming agent. Approximately 28-30 oz/yd2 of
this foamed adhesive latex was applied to the primary
backing, and the primary and secondary backings were
adhered together.
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Prior to the latex curing oven, the outer
surface of the secondary backlng was treated with a foam
application of about 3 ounces per square yard of the
following non-modified latex formulation:
~ A carboxylated acrylate latex polymer (38-45
active ingredient), available from Dow Chemicals, Midland
MI as XUR 1540-1156-1 experimental latex and 10 grams/
liter of a foaming agent, KAF 300S, available from the
PeachState ~abs.
The treated carpet sample was then passed
through a latex curing oven at an oven temperature of 350
to 400~F and the latex was dried. The carpet sample was
then cooled to room temperature before being subjected to
the Staining Test.
A sample from the treated carpet was placed on
blotter paper and was stained with Kool-Aid as described
in the Staining Test. The carpet sample was substantially
impervious to the Kool-Aid stain.
Another sample from the treated carpet was
placed on a blotter paper and was stained as described in
the Staining Test with the exception that the hot coffee
(150~F) was substituted for Kool-Aid as the staining
agent. The blotter paper was moderately stained with
coffee and this sample did not pass the Staining Test.
~xam~le 5
A residential cut pile carpet sample (about 5/8"
pile height; 33 oz./yd2 weight) was produced by a
conventional mill process. The pile surface of the carpet
was treated with topical stain resist and fluorochemical
agents according to st~n~rd mill procedures. The carpet
was composed of nylon 6,6 BCF face fiber, a woven
polypropylene primary backing, an adhesive latex and a
woven polypropylene secondary backing. The adhesive latex
was composed of a mixture of a carboxylated styrene
butadiene rubber, calcium carbonate, water, a thickening
agent and a foaming agent. Approximately 28-30 oz/yd2 of
this foamed adhesive la~ex was applied to the prima~y
CA 02209380 1997-07-03
W O96/22414 PCTrUS96/00329
backing, and the primary and secondary backings were
adhered together.
r After exiting the latex curing oven (temperature
of 350~ to 400~F), the outer surface of the secondary
backing was treated with a hydrophobic polymeric latex
consisting essentially of a latex polymer (as described
below in Table I) and not containing any fillers,
fluorochemicals, or other repellent finishes. The
hydrophobic latex was applied to the secondary backing by
brushing the latex coating onto the backing until the
entire surface was covered.
CA 02209380 1997-07-03
WO96/22414 PCT~S96/00329
TART.~2 I
Trade N:~m~ T.~teX, ~h~m; cal Coating Solids
5 and Com~n.y Description (Grams/S~. Yard)
CONTRQL NONE _~E
Dow CorLung Fabric
Coating 60 silicone al~tnmar 450
Dow Corning Fabric
Coating 61 silicone Rl~tomar 320
DuPontNe~ e2161 polvinylchloride 545
DuPont Nco~.~,.. c 115 polyvinyl chloride 410
DuPontNeoprene2900 polyvillylchloride 420
2 o Air P~udhct~ Airflex 4500 pol~inyl chloride 685
Air P~uduct~ Air~ex 4530 polyvillyl chloride 660
Air Products Airfle~ 420 acrylic copolymer 400
AirProductsAirnex405 polyv.l.ylacetate 640
2 5 Air PLUdUL~ Airflex 410 polyvinyl acetate 380
AirP~ t~Airflex430 pol~villylchloride 720
Air Products Air~ex 460 polyvil,yl acetate 465
Air Products Airflex 4514 ~inyl Ch~ P.~ lo~.cl
acrylamide terpolymer 875
B.F. Goodr-rh Hycar 1552 butadienelac.,~lc Lile
copolymer 365
B.F. Goodrich Hycar 2671 acrylic polymer 300
3 5 B.F. Goodrich Hycar 2679 acrylic polymer 385
B.F. Goo-Arirh Hycar 26138 acrylic polymer 545
B.F. Cocd~ ;r.h Hycar
11572X64 acry-lic polymer 465
B.F. Goc-A-lirh H~ .h
40 V43 ethyl acrylate and
ac. ~l~ide pol~- 31;~ 375
B.F. Goodrich Hy~ .,h
V60 ethyl acrylate and
acryla~ide polymers 375
B.F. Go~Arirh Good-
rite 2570X59 st~enel~hl~t~AianR
copolymer 520
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WO96/22414 PCT~S96/00329
The carpet samples treated with the above-
described hydrophobic polymeric latexes were placed on
blotter paper and stained with Kool-Aid as described in
the above Staining Test under "Testing Methods". Each of ==
these carpet samples were substantially impervious to the
Kool-Aid Stain.
The "Control" carpet sample, as described above,
was placed on blotter paper and stained with Kool-Aid as
described in the Staining Test. The blotter paper was
severely stained by the Kool-Aid.
