U.S. patent number 3,864,195 [Application Number 05/357,887] was granted by the patent office on 1975-02-04 for stable synthetic carpet backing material.
Invention is credited to Henry G. Patterson.
United States Patent |
3,864,195 |
Patterson |
February 4, 1975 |
STABLE SYNTHETIC CARPET BACKING MATERIAL
Abstract
A dimensionally stable and non-raveling synthetic primary carpet
backing material is provided by applying to the carpet backing
material an amount of adhesive material sufficient to bind adjacent
and crossing strands of material to one another without necessarily
providing a continuous coat for the backing material. After
application of the adhesive material, the backing may be subjected
to a conventional tufting operation wherein carpet yarn is
interlaced through the carpet backing to provide a pile surface and
an undersurface. If desirable a conventional secondary backing may
be adhered to the undersurface of carpet yarn and synthetic primary
carpet backing material.
Inventors: |
Patterson; Henry G. (Dalton,
GA) |
Family
ID: |
26915557 |
Appl.
No.: |
05/357,887 |
Filed: |
May 7, 1973 |
Current U.S.
Class: |
428/94;
428/95 |
Current CPC
Class: |
D05C
17/023 (20130101); Y10T 428/23971 (20150401); D10B
2321/021 (20130101); Y10T 428/23979 (20150401); D10B
2321/022 (20130101) |
Current International
Class: |
D05C
17/00 (20060101); D05C 17/02 (20060101); D05c
017/02 () |
Field of
Search: |
;161/62-67,86,88,90,92,149 ;156/88,72
;260/29.4UA,23H,29.2N,29.2TN,29.7,897B |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: McCamish; Marion E.
Attorney, Agent or Firm: Jones, Thomas & Askew
Parent Case Text
This application is a division of Ser. No. 221,166, filed Jan. 27,
1972 which is a continuation-in-part of Ser. No. 877,777, filed
Nov. 18, 1969, now abandoned.
Claims
I claim:
1. A tufted pile fabric comprising a woven sheet of backing
material having a substantially uniform thickness and a plain 1/1
weave of substantially uniform flat strands of plastic material; an
adhesive material adhering adjacent and crossing strands of plastic
material to one another; and rows of carpet yarn piercing said
strands and said adhesive material to provide a face of tufted yarn
on one side of said woven backing and tuft loop backs of yarn on
the other side of said woven backing; all of said adhesive material
being disposed on the woven backing material and none of the
adhesive material being disposed on the tuft loop backs for said
carpet yarn.
2. A tufted pile fabric as in claim 1 wherein the adhesive material
consists essentially of a styrene-butadiene latex material,
melamine-formaldehyde resin and water.
3. A tufted pile fabric as in claim 1 wherein the adhesive material
consists essentially of a carboxylated styrene-butadiene latex
material, melamine-formaldehyde resin and water.
4. A tufted pile fabric as in claim 1 wherein the adhesive material
consists essentially of ethylene vinyl acetate, paraffinic wax and
an oil extender.
5. A tufted pile fabric as in claim 1 wherein the adhesive material
consists essentially of a mixture of water; a polyol having a
hydroxyl number of less than 100 and a functionality of at least
two, said polyol being selected from the group consisting of
polybutylene glycol, polyethylene glycol, 1,2-polydimethylene
glycol, polydecamethylene glycol, and mixtures thereof; an aromatic
diisocyanate selected from the group consisting of 2,4-toluene
diisocyanate, 2,6-toluene diisocyanate, methane diisocyanate
naphthylene 1,4-diisocyanate, diphenylmethane-4,4'-diisocyanate,
3,3'dimethoxy biphenylene diisocyanate, 4,4-diphenylene
diisocyanate, and mixtures thereof; a filler selected from the
group consisting of silica, asbestos, calcium carbonate, zinc
oxide, clay, feldspar and mixtures thereof; and a polyurethane
catalyst.
6. A tufted pile fabric as in claim 1 wherein a layer of second
adhesive material is disposed on the tuft loop backs and the woven
backing adhesive to secure the tuft loop backs in place in the
woven backing material.
7. A tufted pile fabric as in claim 1 wherein a layer of second
adhesive material is disposed on the tuft loop backs and the woven
backing adhesive and a second woven backing material is adhered to
the tufted woven backing material by the second adhesive material.
Description
This invention relates to a primary carpet backing material and to
an adhesive formulation which when applied to the backing material
will reduce the raveling capability of the material without an
undesirable increase in the needle resistance provided by the
backing material during a tufting operation and will increase the
adhesion capability of the synthetic backing material.
Conventionally tufted carpet is prepared in a tufting operation in
which carpet yarn is interlaced through a primary backing
(conventionally a jute material) to produce a pile surface and an
undersurface. After the tufting operation is completed, a rubber or
resinous coating is applied to the undersurface of the tufted
product or an adhesive material and a secondary backing are applied
to the undersurface. Both operations secure the carpet yarn in
place and increase the dimensional stability of the carpet
product.
Recently a new carpet backing material has come into use. This
material is woven from flat strands of synthetic material which are
substantially uniform in thickness and width. U.S. Pat. No.
3,110,905 discloses such a product and the inherent advantages
provided thereby. Since the product has been adopted for use,
certain disadvantages have become apparent. Most significantly, the
woven material tends to ravel at the edges due to the inherently
slipping characteristics of the flat strands. Consequently, during
installation of the tufted product, the backing material pulls
apart under lateral tension and fails to withstand normal use.
In addition it has been found that the flat woven synthetic
material exhibits little or no adhesion for a conventional latex
secondary backing adhesive. Because of this poor adhesion
performance, the woven material has been usable to date only as a
primary backing substrate, and even in that application a secondary
backing of jute or other conventional backing material adheres only
to the backs of the yarn tufts and does not bond to the primary
backing itself. Consequently, the pile loops are not as securely
locked into the synthetic primary backing material as with more
commonly used jute to which conventional latex laminating adhesives
bond securely.
It is an object of the present invention therefore to provide an
adhesive material which may be used to increase the adhesion
capability and secure in place the synthetic strands of a woven
synthetic carpet backing material and provide thereby a carpet
product which may be installed and used in conventional fashion.
These and other objects, features and advantages of the present
invention will become apparent from a review of the following
detailed description and the accompanying drawings wherein:
FIG. 1 is an end, or edge, view of the present backing material
used as a primary backing for a tufted pile fabric, showing only
one row of pile loops or stitches;
FIG. 2 is a bottom view of the primary backing shown in end view in
FIG. 1;
FIG. 3 is a bottom view similar to FIG. 2 showing a conventional
synthetic backing material with characteristic fraying and
unraveling of its edges and instability of weave in central
portions of the material; and
FIG. 4 is an end view of a tufted pile fabric having attached
thereto a secondary backing which is of the same or similar
construction and material as that of the primary backing
material.
According to the present invention an adhesive material is provided
for application to a woven synthetic primary carpet backing
material to enhance the dimensional stability of the backing
material, reduce or substantially eliminate the tendency of the
carpet backing material to ravel at the edges, enhance bonding
between the synthetic material and the adhesive employed in the
application of a secondary backing material to the undersurface of
the tufted primary backing material, and increase the overall
usefulness of the synethetic backing material. The invention is
directed specifically to solving problems created by the use of a
synthetic woven backing material and the invention therefore is
limited in that respect. In addition it should be understood that
the carpet backing material must remain susceptible to an efficient
tufting operation. If the adhesive material successfully reduces
raveling but produces a carpet backing that clogs the tufting
needles with adhesive material or slows the tufting operation, the
adhesive is unacceptable. Consequently, it may be seen that the
problem is not one of simply adhering strands of carpet backing
together but it is one of accomplishing adherence without reducing
the tuftability of the backing or detrimentally effecting the other
physical properties of the backing material.
In order to clearly understand the nature of the present invention,
a discussion of the woven synthetic carpet backing material is
initially provided. Such a carpet backing material is composed of a
woven fabric of flat synthetic strands having substantially uniform
thickness and width. Suitable synthetic materials are penetrable by
a tufting needle but are sufficiently strong to provide an adequate
carpet backing. Preferred synthetic materials include polyolefins,
and particularly preferred materials consist of polyethylene and
polypropylene. These synthetic materials are fashioned into solid
ribbons or strands by either direct extrusion into a desired width
and thickness or by slitting a sheet of material at a desirable
width. Optionally these strands of synthetic material may be
fashioned to a width wider than the desired width. The wider strand
may then be folded to provide either a U or Z-shaped
cross-section.
The even width and thickness of the strands of synthetic material
yields a uniform sheet of woven fabric having a thickness
equivalent to two strands at every point in the fabric. This form
of construction automatically eliminates the irregularities and
interstices which are inherent in conventional jute or burlap
backing material. Furthermore, it is possible to control the
thickness and width of the synthetic strands with much greater
precision than is the case with jute and burlap-type backing yarns
so that irregularities due to the interweaving of thin backing
yarns and thick backing yarns are eliminated.
Since the strands of the present backing material are substantially
flat and penetrable by a tufting needle, it is possible for the
tufting machine to interlace substantially uniform and parallel
rows of tufting yarn. When using conventional jute or burlap
backing material, the tufting needles often slide off the arcuate
yarn face and the rows of tufted yarn show areas of uneveness and
irregularity. Consequently, with the present carpet backing
material the longitudinal spacing between each of the stitches of
carpet yarn is approximately the same regardless of whether the
stitch happens to fall in the middle of one of the synthetic
backing strands, inbetween two adjacent backing strands, or near
the edge of one of the backing strands. This characteristic
illustrates the beneficial results achieved when the carpet yarn
carrying tufting needles always penetrate a homogeneous and
relatively uniform woven backing material.
The flat strands of synthetic material have a smooth surface rather
than the textured surface presented by twisted yarn such as
conventionally found in jute and burlap backing. The smooth surface
of the strands causes the weave of the present backing material to
be easily separated and the edges thereof to become ravelled.
In order to improve the dimensional stability of the present woven
backing material, enhance adherence of conventional laminating
adhesives to the synthetic backing material and reduce or
substantially eliminate raveling of the edges of the fabric, an
adhesive is applied to the backing prior to the tufting of carpet
yarn therethrough. The adhesive binds adjacent and crossing strands
of plastic material to one another. The adhesive is one of the
following four groups of compositions: (A) An aqueous dispersion of
a styrenebutadiene latex compound modified with a melamine
formaldehyde resin additive; (B) An aqueous dispersion of
carboxylated styrene-butadiene latex compound modified with a
melamine formaldehyde resin additive; (C) An ethylene vinyl acetate
hot-melt adhesive; and (D) A polyurethane adhesive. Of these
groups, A and B are preferred and A is most preferred. As
additional additives each group of adhesives may also include
thickeners, curing agents, synthetic wax lubricants, antifoams,
stabilizers, emulsifiers, antioxidants, accelerators, surfactants,
and mineral fillers.
The most preferred form of adhesive is a styrenebutadiene copolymer
latex compound modified by a melamine formaldehyde resin additive.
The preferred styrene-butadiene latex compound is a hot-polymerized
type having the following properties:
Total Solids 53.3% Residual Styrene 0.04% PH 11.1 Mooney, ML.sub.4
at 212.degree.F 65 Coagulum, 80 mesh 0.01% Bound Styrene 46.0%
Specific Gravity of Latex 25.degree./25.degree. 0.99
The styrene-butadiene copolymer latex compound is modified by the
addition of a melamine formaldehyde resin thereto. The properties
of this resin are as follows:
Physical Form Clear, viscous syrup at room temperature Solids
Content 80%, Approximately Weight Per Gallon 10 pounds PH of
Aqueous Solution 8.6-9.6 Solubility In water
When preparing this adhesive formulation it is preferred that from
1 to 10 parts of melamine formaldehyde resin per 100 parts of
styrene butadiene latex be employed. In a particularly preferred
embodiment of the present invention 3 to 5 parts of resin per 100
parts of latex compound are employed.
In addition to the melamine formaldehyde resin additive, additional
additives such as thickeners, curing agents, synthetic wax
lubricants, antifoams, stabilizers, emulsifiers, antioxidants,
accelerators, silicon surfactants and mineral fillers may also be
added. A preferred quantity for these additives is from 5 to 20
parts per 100 parts of latex compound.
A preferred group of additional additives include a thickener of
carboxymethylcellulose having the following physical
properties:
Powder Methoxyl 27.0-30.0% Hydroxypropoxyl 4.0-7.5% Sulphated Ash
Max 2.0% Moisture Max 3.0% Chemical Iron Max 150 ppm Sodium
Chloride Max 1.0%;
A lubricant of silicone wax emulsion in water having the following
physical properties:
Appearance white liquid at room temperature Solids 50% Melting
Point 122.degree.F-125.degree.F PH 8-9 Pounds per Gallon 7.9;
An additional thickener of sodium polyacrylate; an accelerator of
zinc oxide; a curing and vulcanizing agent of sulfur; and an
optional silicon surfactant having the following properties:
Color White Total Solids 51-53% Silicone Solids 50% Emulsifier
Anionic Density 8.2-8.3 No./gal.
The second adhesive composition (Group B) employs a carboxylated
styrene butadiene latex compound rather than the styrene butadiene
latex compound. Otherwise the adhesive material is similar to Group
A. The carboxylated sytrenebutadiene latex compound has the
following properties:
Solids 49-51% Surface Tension 40-45 dynes/cm Brookfield Viscosity
at 25.degree.C 100-150 No./at 20 RPM Color White Styrene 48.5%
Butadiene 48.5% Carboxyl Groups 3.0% PH 8.8-9.2
A preferred group of additives in addition to the melamine
formaldehyde resin additive includes a water dilutable silicone
emulsion containing 30% silicone in a nonionic emulsion as an
antifoam agent; a surfactant of sodium tetradecyl sulfate; and a
silicone surfactant having the following physical properties:
Color White Total Solids 51-53% Silicone Solids 50% Emulsifier
Anionic Density 8.2-8.3 No./gal.
When employing these additional additives it is preferred that from
1 to 5 parts total be employed per 100 parts of latex compound.
A third composition (Group C) which may be used as an adhesive
formulation on the woven synthetic carpet backing prior to tufting
thereof is a hot-melt adhesive of ethylene vinyl acetate. Since the
results obtained with this formulation are not as desirable as the
results obtained with the first two compositions, this formulation
is not preferred but does provide suitable results.
When using the hot-melt adhesive it is preferred that from 15 to 25
parts of a paraffinic wax and 2 to 8 parts of a mineral or aromatic
oil extender be employed per 100 parts of adhesive as an additive
thereto. Isotatic polypropylene may also be used as an extender at
a part concentration of 15 to 25 parts per 100 parts of
adhesive.
A fourth composition (Group D) which may be used as the adhesive
formulation is a thixotropic polyurethane material.
The polyurethane adhesive is an essentially non-solvent,
non-aqueous polymerization product of a mixture of a polyol having
a hydroxyl number less than one hundred, a small amount of water, a
polyisocyanate, a filler and a catalyst system that promotes a
polymerization reaction between the isocyanate andd the polyol to
form a polyurethane within a short time after mixing.
The polyurethane composition is prepared by charging an aqueous
polyol composition and a polyisocyanate composition separately to a
mixing zone where the reactants are intimately mixed. Before a
significant degree of polymerization and blowing occurs, the
resultant mixture is evenly applied to the underside of a woven
synthetic primary backing material by means of a doctor blade as
the backing material moves under the doctor blade. The thixotropic
nature of the polyurethane reaction product in combination with the
shear forces created by application of the mixture with a doctor
blade causes a sufficient reduction in the viscosity of the blend
of reactants and product to promote spreading thereof. A
polymerization reaction between the polyisocyanate, water and
polyol is initiated when the reactants are mixed so that the
reaction occurs both prior to and after the mixture-composition
passes under the doctor blade. The small amount of water in the
composition besides promoting the polymerization also causes
controlled foaming to improve adhesive migration around the strands
of backing material before the composition is cured and reduces the
amount of composition needed to attain desired adhesion.
The thixotropic polyurethane material must have a Brookfield
viscosity of between about 30,000 and 100,000 CPS as measured at 10
RPM No. 7 spindle on a Brookfield RVF viscometer to prevent
migration thereof into the exposed yarn while permitting it to
liquify sufficiently under application of force and be spread by
means of a doctor blade. The Brookfield viscometer and its
operation is described in "Development of Research Technique for
Evaluating the Low Temperature Fluidity of Automatic Transmission
Fluids," published by Coordinating Research Council, Inc.,
February, 1963, Appendix A, and designated as CRC L-45-1262. In
order to attain these characteristics, it is essential that the
polyol employed have a hydroxyl number less than one hundred,
preferably less than fifty. As it well known in the art, the
hydroxyl number is defined as the number of milligrams of potassium
hydroxide required for the complete neutralization of the
hydrolysis product of the fully acetylated derivative prepared from
one gram of polyethyl polyol. The hydroxyl number can also be
defined by the equation:
OH = 56.1 .times. 1000 .times. f/MW
wherein
OH = hydroxyl number of polyol
F = average functionality, i.e., the average number of hydroxyl
groups per molecule of polyol
MW = average molecular weight of the polyol.
It is necessary that the polyol have a low hydroxyl number to
reduce the concentration of the diisocynate needed to effect
complete reaction of the reactants to form the polyurethane. When
employing liquid diisocyanates, increased amounts of diisocyanate
reduce the viscosity and thixotropocity of the resultant
composition below that desired. On the other hand, when a solid
diisocyanate reactant is employed, increased amounts thereof will
cause the resultant composition to be paste-like rendering it very
difficult to spread. Accordingly, while low molecular weight
polyols can be employed with solid diisocyanates and high molecular
weight polyols can be employed with liquid diisocyanates, in each
case the hydroxyl number of the polyol must be low to attain proper
physical characteristics of the resultant composition. Accordingly,
when employing solid diisocyanates reactants, the polyol should
have a molecular weight between about 1000 and 3000 to attain the
proper viscosity characteristics of the resultant composition. On
the other hand, when the liquid diisocyanate reactant is employed,
the polyol should have a molecular weight of between about 3000 and
about 9000 to attain the desired viscosity characteristics of the
resultant composition.
In one aspect of the present invention, a polyurethane prepolymer
can be employed to replace or to be mixed with the polyol in the
composition. These prepolymers are prepared by means well known in
the art, i.e., by incomplete reaction of a polyol with a
diisocyanate. The molecular weight of the prepolymer and the type
of diisocyanate should be selected while bearing in mind the
considerations described above.
While careful selection of the polyol or prepolymer and the
diisocyanate provide a means for controlling the viscosity of the
resultant composition, the composition cannot be made thixotropic
to the desired degree by controlling the relative concentrations of
only these two reactants. A suitable filler must be added in
amounts sufficient to render the overall composition thixotropic to
the desired degree but less than that which will cause the
composition to become excessively viscous and paste-like. The
concentration of filler is dependent upon the type of filler
employed since the degree of thixotropicity varies with the filler
used. Generally, the filler is employed in amounts of between about
15 and 300 parts per one hundred parts of polyol or prepolymer
reactant. Representative suitable fillers include silica, asbestos,
calcium carbonate, zinc oxide, clay, feldspar, or the like, or
mixtures thereof. When fillers are employed, such as silica or
calcium carbonate, it is preferred that additional fillers be added
to attain the desired level of thixotropocity. It is preferred to
employ asbestos power as the filler either alone or in conjunction
with another filler such as calcium carbonate as satisfactory
thixotropic characteristics are achieved with asbestos and it
additionally reduces the flamability of the composition.
The type of catalyst system employed in preparation of the
thixotropic polyurethane composition should regulate the pot life
(i.e., the time for a 100 percent viscosity increase) thereof to
between 10 and about 60 seconds at moderate temperatures of up to
about 23.degree.C. It is preferred that from 0.03 to one part of
catalyst per one hundred parts of polyol be used in the reaction
mixture.
It is desirable to employ a polyurethane composition that cures
relatively quickly, and it is preferred that curing be effected at
a temperature of from room temperature to 275.degree.F and a
corresponding cure period of 45 minutes to 1 1/2 minutes.
Blowing or foaming the polyurethane composition is effected by
controlling both the catalyst system and the water concentration.
Generally, water is present in the reaction mass from between about
0.01 and 0.75 parts per hundred parts polyol, over and above the
water normally present as absorbed on the filler. Since this is
such a small quantity of water, the present polyurethane
composition is considered non-aqueous and described as such.
Conventionally, adhesive systems contain as much as 50% water. The
catalyst system not only must effect rapid curing at ambient or
slightly elevated temperature but also must control formation of
carbon dioxide resulting from the reaction of water and
diisocyanate. Suitable catalysts are those which promote
polyurethane formation at a high rate but do not promote the
blowing reaction in preference to the polyurethane reaction.
Preferred catalysts are organic metal compounds, amines, and metal
soaps; such catalysts include dibutyl tin dilaurate and stannous
octoate.
Suitable polyols which can be employed in the present invention are
the polyether polyols having a functionality of at least two, an
average molecular weight between about 1000 and 9000 and a hydroxyl
number less than one hundred. Such polyols include polybutylene
glycol, polyethylene glycol, polypropylene glycol,
1,2-polydimethylene glycol, polydecamethylene glycol and mixtures
thereof. When using a liquid diisocyanate reactant, preferred
polyols have an average molecular weight of between 4000 and 8000,
and particularly preferred polyols have a molecular weight of
between 6000 and 7000. When using a solid diisocyanate reactant,
preferred polyols have an average molecular weight of between 1200
and 2800, and particularly preferred polyols have a molecular
weight of between 1500 and 2500.
A variety of polyisocyanates may be reacted with these polyols to
obtain a satisfactory polyurethane composition. Particularly
suitable polyisoicyanates are aromatic diisocyanates as they are
more reactive and less toxic than the aliphatic diisocyanates. Such
diisocyanates include 2,4-toluene diisocyanate, 2,6-toluene
diisocyanate, methane diisocyanate, naphthylene 1,4-diisocyanate,
diphpenylmethane-4, 4'-diisocyanate, 3,3'-dimethoxy biphenylene
diisocyanate, 4,4-diphenylene diisocyanate and mixtures thereof.
The diisocyanate usually is employed in stoichiometric excess to
assure complete reaction with the functional groups of the polyol
and with water which is present. Preferably from 18 to 50 parts of
diisocyanate per one hundred parts of polyol are used in the
reaction mass.
When using either of Groups A, B, C, or D adhesive formulation, it
is preferred that from 0.2 ounces to 1.5 ounce of adhesive be
applied to the backing per square yard of backing; a particularly
preferable concentration is 0.3 to 0.45 ounces. As the adhesive
material is applied to the backing an area of bonding is created at
the points of crossing and in adjacent areas between warp and weft
strands of synthetic yarn. Consequently, it is not necessary that
the adhesive form a continuous coat over the woven backing
material, only that areas of bonding be created at these points of
junction and at adjacent points between strands.
The adhesive material may be applied to the backing material be
several methods. One such method involves submerging the sheet of
material in a bath of adhesive and then passing the sheet between
pad rollers to squeeze off excess adhesive and enhance penetration
of the adhesive through the backing material. Other methods involve
painting the adhesive on the undersurface with rollers or doctor
blades then passing the material through pad rollers to remove
excess material and enhance penetration of the adhesive through the
backing.
Referring now with more particularity to the drawings, there is
shown in FIG. 1 an end or edge view of a tufted pile fabric having
one row of carpet yarn stitched therethrough. FIG. 2 shows an
undersurface view of the synethtic woven backing material with one
row of carpet yarn stitched therethrough. The warp yarns of the
weave are shown as 1 to 10 and the weft yarns are shown as 11 to
23. In a typical tufting operation, the woven carpet backing
material is fed into a tufting machine where carpet yarn 28 is
stitched through the backing to produce loops 27 of carpet yarn on
the upper face of the backing. In the present invention, a primary
backing composed of flat ribbons or strands of synthetic material
are employed as the weaving material of the backing and an adhesive
material 25 is applied to the backing prior to the tufting
operation. Since such a small quantity of adhesive (0.2 ounces to 1
ounce per square yard of backing) is applied to the backing it is
difficult to depict the presence of the adhesive in the drawing. It
should be understood however that the adhesive is generally located
at the points of crossing between warp and weft ribbons and between
adjacent warp ribbons and weft ribbons to secure those ribbons to
one another.
By contrast, as shown in FIG. 3, a conventional woven synthetic
backing material composed of flat ribbons of weaving material has
no coherence except that provided by the weave, and the backing
tends to unravel at the edges and separate in central portions of
the material. In use it has been found that the conventional
material will undergo seam and tack slippage during installation of
the finished carpet product.
As shown in FIG. 4, it is possible with this invention to use a
secondary backing 30 of synthetic woven material which is treated
according to the present invention to increase its dimensional
stability and enhance its adhesion characteristics. A carpet
product employing both primary and secondary backing of woven
synthetic material would be stronger than a carpet employing
conventional backing materials and would be virtually impervious to
moisture and its attendant problems.
The present invention is further illustrated by the following
examples:
EXAMPLE I
A primary backing of woven synthetic material is treated with an
aqueous dispersion of latex material. The backing is woven from
ribbons of polypropylene with a plain 1/1 weave. The ribbons are
approximately one-eighth of an inch in width and one thirty-second
of an inch in thickness. The aqueous dispersion of latex material
has the following composition:
MATERIAL PARTS BY WEIGHT ______________________________________
Water 302.80 Styrene-butadiene hot- polymerized latex compound
100.00 Melamine-formaldehyde resin 4.00 Carboxymethylcellulose .40
Silicone wax emulsion 1.50 Sodium polyacrylate 4.00 Sulfur 2.50
Zinc Oxide 4.00 ______________________________________
The woven backing material is dipped into a bath of the latex
material and passed through a pair of squeeze rollers. It is
estimated that 0.4 ounces of latex material remains on the backing.
The backing is then dried and passed through a tufting machine
where row tufting needles stitch nylon carpet yarn into the
backing. The tufting operation was performed with no difficulties
and needle puncture was not impeded. A secondary backing was then
adhesively laminated to the tufted primary backing and the
resulting carpet product was tested for strength and raveling. It
was found that the secondary backing was adhered to both the backs
of the carpet yarn tufts and the undersurface of the primary
backing. The carpet was tacked along one edge and stretched from an
opposite edge and raveling did not occur.
EXAMPLE II
Example I is repeated except that the following latex formulation
is employed:
MATERIAL PARTS BY WEIGHT ______________________________________
Water 133.43 Styrene-butadiene hot- polymerized latex compound
100.00 Melamine-formaldehyde resin 3.00 Carboxymethylcellulose .40
Silicon wax emulsion 1.50 Silicone antifoam emulsion .05 Highly
sulfated fatty acid .50 Polyoxyethylene oleyl ether .15 Dry Casein
.50 Pentasodium triphosphate .50 Hindered Bis Phenol 1.50 Zinc salt
of z-mercaptobenzothiazole .50 Zinc diethyldithiocarbamate .50 Zinc
oxide 4.00 Anionic emulsion of a silicone fluid as a surfactant
3.00 Sodium polyacrylate .40 Sulfur 2.00
______________________________________
The formulation is applied to the backing material as in Example I
and suitable results are obtained.
EXAMPLE III
Example I is repeated except that the following latex formulation
is employed:
MATERIAL PARTS BY WEIGHT ______________________________________
Carboxylated styrene-butadiene latex 100 Water 328.60 Silicone
emulsion antifoam .01 Melamine formaldehyde resin 3.00 Sodium
tetradecyl sulfate .25 Anionic emulsion of a silicone fluid as a
surfactant 3.00 ______________________________________
The formulation is applied to the backing material as in Example I
and suitable results are obtained.
EXAMPLE IV
Example I is repeated except that the following hot-melt adhesive
formulation is employed:
MATERIAL PARTS BY WEIGHT ______________________________________
Ethylene vinyl acetate 100 Paraffinic wax 20 Mineral oil extender 5
Isotatic polypropylene 20
______________________________________
The formulation is heated and applied to the backing material as in
Example I and suitable results are obtained.
EXAMPLE V
Example I is repeated except that the following polyurethane
adhesive formulation is employed:
MATERIAL PARTS BY WEIGHT ______________________________________
Polypropylene glycol- 100 OH of 25 and M.W. of 6500 Water .50
Asbestos powder having an average particle size of about 5-50
microns 15.0 Calcium carbonate having an average particle size of
about 50-150 microns 100.0 Dibutyl tin dilaurate 0.05 Modified
diphenylmethane- 4,4-diisocyanate 30.0
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The formulation is applied to the backing with a doctor blade and
the backing is then passed between squeeze rollers to remove excess
adhesive. The adhesive is then cured for a period of 20 minutes at
a temperature of 135.degree.C. The backing is then tufted and
tested as in Example I and suitable results are obtained.
While this invention has been described in detail with particular
reference to preferred embodiments thereof, it will be understood
that variations and modifications can be effected within the spirit
and scope of the invention as described hereinbefore and as defined
in the appended claims.
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