Note: Descriptions are shown in the official language in which they were submitted.
-
11535~Z
1 - D~K-6219 & 6313
ASBESTOS-FRE~ RUBBERIZED FLOORING FELT
This invention relates to asbestos-free, rubberized felts.
~ lore specifically, this invention relates to beater
saturated, water-laid, asbestos-free, rubberized felts which are
dimensionally stable and, accordingly, are well suited for use as
felt backing sheets for resilient flooring.
Asbestos-containing rubberized felts are well known and
have achieved unprecedented commercial success in the resilient
flooring industry as backing or foundation sheets for decorative
floor coverings. These asbestos-containing rubberized felts are
produced by beater saturating asbestos fibers with a rubber latex in
an aqueous system and forming the felt product on conventional
papermaking equipment. See, for example, U. S. Patent Nos.
2,375,245; 2,fil3 190; and 2,759,~13. The commercial success of
these asbestos-containing rubberized felts has been primarily due to
the physical and chemical properties imparted to the felts by the
asbestos fibers. The asbestos fibers alone facilitate the produc-
tion of felts which can be easily processed, are dimensionally
stable, exhibit excellent hot tensile strength and are alkali,
moisture and microbiologically resistant~ ~o other single fibrous
material is known which can replace asbestos fibers in flooring
felts and provide felts having acceptable properties, especially
dimensional stability and hot tensile strength.
1153S12
- 2 - DMK-6219 & 6313
~ he health hazard problems of asbestos fibers are alæo
well known and, accordingly, the flooring industry has long been
searching for replacement flooring felts which do not contain
asbestos fibers but yet achieve substantially the same physical and
chemical properties as the prior art asbestos-containing rubberized
felts. Especially important and critical in the flooring industry
is that the replacement flooring felt be dimensionally stable and
exhibit good hot tensile strength.
If a flooring felt does not exhibit good hot tensile
strength, it will not withstand conventional, resilient floor
covering processing temperatures.
If a flooring felt is not dimensionally stable, it will
grow when exposed to moisture, thus causing growth in the entire
floor covering. This growth presents a major installation problem.
During installation when the felt comes in contact with wet adhesive
it grows and~this growth results in the distortion of an in-register
decorative pattern at double cut seams. This growth can also result
in buck]es or wrinkles in the floor covering.
The present invention helps solve the above problems and
provides a beater saturated, water-laid, asbestos-free, rubberized
felt which is dimensionally stable.
For the purposes of this invention, a felt which exhibits
more than +0.30~ change in its cross machine twidthwise) direction
i.s considered tv be unsuited for use to produce floor coveringsO
As used herein, the term "dimensional stability" means
that t:he flooring felt exhibits +0.30~ or less and, preferably,
+0.2d~ or less growth change in its cross machine (widthwise) direc-
tion when ~ested according to the standaræized High Humidity
Dimensional Stability Test procedure set forth below.
Two l" by 9" samples of the felt to be tested are cut from
the felt in its cross machine (wi~thwise) direction. If testing a
felt handsheet made in a handsheet mold which has no machine or
cross machine direction, the direction of cut is not important.
Each sample is tested individually as follows:
llS3512
- 3 - DMR-6219 & 6313
Hi~h ~umiditv Dimensional Stability Test conditions
(1) The sample is placed in a circulating air oven
and heated for six hours at 180-F.
(2) The sample is removed from the oven and cooled
in a desiccator over CaC12 for 1/2 bour at
73.4- F.
(3) The sample is removed from the desiccaSor and
the distance between two reference points
~initial distance) is measured accurately to a
thousandth of an inch.
(4) The sample is then placed in a humidity cabinet
and heated for 24 hours at 100-F and 90% rela-
tive humidity.
(5) The sample is removed from the humidity cabinet
and cooled in a desiccator for 1/2 hour over
water.
(6) The sample is removed from the desiccator and
the distance between the two reference points
remeasured (final distance) accurately to a
thousandth of an inch, and the initial distance is
subtracted from the final distance to give the
change in inches.
The resulting change in inches is divided by the initial distance in
inches and multiplied by 100 to give the % change for each sample.
The % change of each of the two samples are averaged to give the %
change in widthwise direction which is the unit of measure for dimen-
sional stability. Reference is made to Federal Standard 501a, Method
6211.
~lS351Z
- 4 - DM~-6219 ~ 6313
~ ccording to this invention, there is provided a beater
.saturated, water-laid, asbestos-free, rubberized flooring felt which
is dimensionally stable, produced by removing water from an aqueous
furnish composition comprising glass fibers, cellulose pulp,
fibrillated polyolefin fibers, at least one inorganic filler, a
synthetic rubber binderr a soluble salt selected from the group con-
sisting of aluminum salts, ferric salts and stannic salts, and a
sufficient amount of an alkaline hydroxide to provide a furnish p~
within the range from about 6 to about 10, the alkaline hydroxide
serving to convert the soluble salt to a water insoluble hydroxide.
Also according to this invention there is provided a sur-
face covering comprising (a) a beater saturated, water-laid,
asbestos-free rubberized flooring felt which is dimensionally stable
produced by removing water from an aqueous furnish composition
comprising glass fibers, cellulose pulp, fibrillated polyolefin
fibers, at least one inorganic filler, a synthe~ic rubber binder, a
soluble salt selected from the group consisting of aluminum salts,
ferric salts, stannic salts and a sufficient amount of an alkaline
hydroxide to provide a furnish pH within the range from about 6 to
about 10, the alkaline hydroxide serving to convert the solubl~ salt
to a water insoluble hydroxide and (b) a decorative wear surface
joined to the rubberized flooring felt.
In its preferred form, the aqueous furnish composition
will also include a papermaking wet strength resin and a latex
antioxidant. Optionally, the aqueous furnish composition can con-
tain retention aids, biocides and the like.
~153S12
- S - DMR-6219 & 6313
The aqueous furnish composition will contain from about 1
to about 10 parts by weight of conventionally surface treated chopped
glass fibers per 100 parts of the total fiber and filler weight.
Suitable glass fibers will have nominal fiber lengths within the
range of from about 1/16" to about 1/2" and nominal fiber diameters
within the range of from about 0.0002" to about o.ooosn.
Two parti~ularly suitable chopped glass fibers are
available from Owens-Corning Fiberglas* Corporation as 1/8" "D-E 636
Glass Fibers" and 1/8 n nD-E 670-8 Glass Fibers.~
The aqueous furnish composition will contain from about 2
to about 20 parts by weight of cellulose pulp per 100 parts of the
total fiber and filler weight. In this invention, for the purpose
of determining amounts of ingredients, cellulose pulp is considered
a fiber ingredient. Any suitable cellulose pulp ~an be ~mployed,
including bleached and unbleached sulphite pulp, softwood pulp,
kraft pulp, ~ewspaper pulp, and the like. A particularly suitable
cellulose pulp is ~Unbleached Sulphite Pulp" available from ITT
Rayonier.
Any suitable fibrillated polyolefin fibers can be employed
in an amount of from about 1 to about 20 parts by weight fibrillated
polyolefin fibers per 100 parts of the total fiber and filler
weight. Particularly suitable fibrillated polyolefin fibers are
fibrillated polyethylene fibers and fibrillated polypropylene
fibers.
A particularly suit~ble fibrillated polyethylene fiber is
grade E-620 "Fybrel*" commercially available from Crown Ze11erbach
Grade E-620 Fybrel* has an average weighted fiber length of 1.3mm as
measured in a Bauer-McNett classifier and a drainage factor of 6
seconds/gram. The drainage factor equals the drainage rate of a 10
gram sample measured in a Standard sritish handsheet mold expressed
in seconds per gram.
*Trademark
~15351Z
- 6 - D.~-6219 ~ 6313
Other fibrillated polyolefin fibers which are sultable for
use are grades E-400, E-600, E-780, E-790, and R-830 of l'Fybre1*,';
all commercially available ~rom Crown Zellerbach, grades A and D of
"Pulplex E*" both fibrillated polyethylenes available from Bercules,
Inc., and ~rade AD, "Pulplex P*" a fibrillated polypropylene also
available from Hercules, Inc.
~ he aqueous furnish composition will contain at least one
inorganic filler present in an amount within the range of ~rom about
50 to 96 parts by weight total inorganic filler per 100 parts of the
total fiber and filler weight. The inorganic filler will be selected
from the group consisting of paper filler clay, wollastonite, talc,
calcium carbonate, mica, pyrophyllite ~nd diatomaceous earth.
Particularly suitable fillers include wollastonite of P-4, P-l, or C-l
grade, all commercially available from Interpace Co. and Koalin Clays
designated "Hi-Opaque Clay*," commerciall~ available from Freeport
Kaolin Clay Co., and "Klondyke*" clay or "K1Ondyke KWW*" clay, both
commercially avai~abl`e from Engelhart Minerals & Chemicals Corp.
Pyrophyllite is a hydrous aluminum silicate and is commercially
available as "Pyrax*" from R.T. Vanderbilt Company, Inc.
The aqueous furnish composition will contain from about 10
to about 40 parts by weight add-on of a synthetic rubber latex per
every 100 parts of the total fiber and filler weight. Any suitable
synthetic rubber latex can be be employed including
styrene/butadiene late~es, carboxylated styrene/butadiene latexes,
polychloroprenes, carboxylated polychloroprenes, vinyl
pyridene/styrene/butadiene terpolymers, and the like. Carboxylated
styrene/butadiene latexes are particularly suitable for use in this
invention, one such material being designated "Dylex* 1187," commer-
cially available from Arco* Polymers, ~ ., a subsidiary of tlle
Atlantic Richfield Company. Dylex* 1187 has a total solids of about
44 to 50 weight percent, a pH of from 9 to 10, a surface tension of
60 to 70 dynes/cm., a Brookiield viscosity of 1 to 300, and weighs
8.40 pounds/gallon.
The aqueous furnish composition will preferably contain
from about 0.02 to about 2 parts by weight add-on of a conventional
papermaking wet stren~th resin per 100 parts of the total fiber and
filler weight. Particularly suitable wet strength resins are
*Trademark
~535~2
- 7 - DMR-6219 & 6313
designated "Kymene* 2064" and "Kymene* 557H," both commercially
available from Hercules, Incorporated. Kymene* 2064 and Kymene* 557H
~re water ~olutions of cationic amine polymer-epichlorohydrin
adducts.
S The a~ueous furnish composition will preferably contain
from about 0.2 to about 1.6 parts by weight add-on of a latex
antioxidant per 100 par~s of the total fiber and filler weight. A
particularly suitable latex antioxidant is designated "Flectol H,*"
com~ercially available from Monsanto Industrial Chemicals Company.
10 Flectol H* is polymerized 2,2,4-trimethyl-1,2-dihydroquinoline.
The foll~Jing examples demonstrate the preparation of
dimensionally ctable, asbestos-free rubberized flooring felts of
this invention.
ExamDle I
This mixing procedure is based on the preparation of an
a~ueous furnish using the following ingredients. ~11 amounts of
ingredients are in parts per 100 parts by weight of the total fiber
and filler weight.
In~redients Amount
glass fibers (1/8" D-E 636, Owens-Corning
Fiberglas) 2.25
fibrillated polyethylene (grade E-620 Fybrel) 2.75
cellulose pulp
unbleached sulfite pulp (ITT Rayonier) 7.5
softwood pulp (Westvaco*) 2.5
filler
wollastonite (P-4) 60
clay (Hi-Opaque*) 25
Total 100
-
antioxidant (F'ectol H) 0~4
wet strength resin (Kymene 5;7~) 0.4
synthetic rubber latex (Dylex 1187) 17
aluminum sulfate 7.65
*Trademark
.. . .
~1535~Z
- 8 - DMR-6219 & 6313
To a mixing vessel containing about 300 milliters of ~ap
water were added the total amounts of the glass fibers, fibrillated
polyethylene~ cellulose pulp, filler, and antioxidant. The contents
of the mixing vessel were slurried for about 1/2 to 1 minute to
insure full dispersion of the ingredients.
The slurry was then diluted with tap wa.er at a tem-
perature of about 75-F. to a total volume of 2.3 liters at 2~ con-
sistency and homogenously mixed using an air stirrer.
To the resulting homogeneous mixture was added the total
amount of wet strength resin with stirring for about one minute.
Next, the total amount of aluminum sulfate was added with
stirring for about 2 minutes, followed by the addition of ammonium
hydroxide to a slurry pH of about 7 to 7.5
The total amount of synthetic rubber latex was then added
lS with stirring for about 5 minutes until the latex precipitated,
that is, the latex deposited on the fibers and fillers thus serving
as a drainage aid and a binder in the resulting felt.
The resulting slurry was then formed into a handsheet
using a conventional Williams handsheet mold. The resulting
handsheet was then wet pressed to remove excess moisture and drum
dried at a temperature of about 230-F.
The resulting dried handsheet was recovered as rubberized
flooring felt of this invention suitable for use to produce resi-
lient floor coverings. The felt was tested and found to have a
gauge, after calendering, of about 0.025 inch.
Exam~le II
This mixing procedure is based on the preparation of an
aqueous furnish using the following ingredients. All amounts of
ingredients are in parts per 100 parts by weight of the total fiber
and filler weight.
~lS3SlZ
- 9 - DMK-6219 & 6313
Ingredients Amount
~lass fibers ~l/8" D-E 670-8; Owens-Corning
Fiberglas) 2.5
fibrillated polyethylene (grade E-620 Fybrel) 2.75
cellulose pulp
newsprint pulp 8
softwood pulp (l~estvaco) 2
filler
wollastonite (C-l) 55
clay (I~londyke) - 29.75
Total 100
antioxidant (Flectol H) 0.5
wet strength resin (Kymene 2064) 0.5
synthetic rubber latex (Dylex 1187) 17
aluminum sulfate 7.65
To a mixing vesse] containing about 300 milliters were
added a total amount of glass fibers, fibrillated polyethylene,
cellulose pulp, filler and antioxidant. The contents of the mixing
vessel were slurried for about 1/2 to 1 minute to insure full
dispersion of the ingredients.
The slurry was then diluted with tap water at a tem-
perature o about 75-F. to a total volume of 2.5 liters at 2~ con-
sistency and homogeneously mixed using an air stirrer.
To the resulting homogeneous mixture was added the total
amount of wet strength resin with stirring for about 1 minute.
Next, the total amount of aluminum sulfate was added with
stirring for about 2 minutes followed by the addition of ammonium
hydroxide to a slurry pM of about 7 to 7.5.
1~5351Z
- 10 - DMK-6219 ~ 6313
The total amount of synthetic rubber latex was then added
with stirring for about 5 minutes until the latex precipitated, that
is, the latex deposited on the fibers and fillers thus serving as a
drainage aid and a binder in the resulting felt.
The resulting slurry was then formed into a handsheet
: using a conventional Williams handsheet mold. The resulting
handsheet was then wet pressed to remove excess moisture and drum
dried at a temperature of about 230-F.
The resulting dried handsheet was recovered as a rub-
berized flooring felt of this invention suitable for use to produce
resilient floor coverings. The felt was tested and found to have a
gauge of about 0.0246 inch.
ExamPle III
Using substantially the procedure of Example II, a
handsheet was prepared using the following ingredients.
Ingredients Amount
glass fibers (1/8" D-E 670-8: Owens-Corning
Fiberglas)
fibrillated polyethylene (grade E-620 Fybrel) 2.75
20 cellulose pulp
newsprint pulp 8
softwood pulp (~estvaco) 2
filler
wollastonite (C-l) 55
clay (I~londyke) 31.25
Total 100 ~-
antioxidant (Flectol H) 0.5
wet strength resin (Kymene 2064) 0.5
synthetic rubber latex (Dylex 1187) 17
30 aluminum sulfate 7.65
~1S3S~2
- 11 - DMK-6219 & 6313
The resulting handsheet was recovered as a rubberized
flooring felt of this invention suitable for use to produce resi-
lient floor coverings. The felt was tested and found to have a
gauge of about 0.0240 inchO
Example IV
Using substantially the procedure of Example II, a
handsheet was prepared using the following ingredients.
Ingredients Amount
glass fibers (1/8" D-E 670-8; Owens-Corning
Fiberglas) 1.67
fibrillated polyethylene (grade E-620 Fybrel) 2.75
cellulose pulp
newsprint pulp 8
s,oftwood pulp (Westvaco) 2
15 filler
wollastonite ~C-l) 55
clay (Rlondyke) 30.58
Total 100
antioxidant (Flectol H) 0.5
20 wet strength resin (Kymene 2064) 0.5
synthetic rubber latex (Dylex 1187) 17
aluminum sulfate 7.65
The resulting handsheet was recovered as a rubberized
flooring felt of this invention suitable for use to produce resi-
25 lient floor coverings. The felt was tested and found to have a ;
gauge of about 0.0250 inch.
11535~2
- 12 - DMK-621~ & 6313
Examp:Le V
Using substantially the procedure of ~xample II, a
handsheet was prepared using the following ingredients.
In~redients Amount
glass fibers (1/8" D-E 670-8; Owens-Corning
Fiberglas) 1.25
fibrillated polyethylene ~grade E-620 Fybrel) 2.75
cellulose pulp
newsprint pulp 8
softwood pulp (~estvaco) 2
filler
wollastonite (C-l) 55
clay (Klondyke) 31 _
Total 100
antioxidant (Flectol H) 0.5
wet strength resin (Kymene 2064) 0.5
synthetic rubber latex (Dylex 1187) 17
aluminum sulfate 7.65
The resulting handsheet was recovered as a rubberized
flooring felt ~f this inven~ion suitable for use to produce resi-
lient floor coverings. The felt was tested and found to have a
gauge of about 0.0250 inch.
Exam~le VI
Using substantially the procedure of Example II, a
handsheet was prepared using the following ingredients. This slurry
was diluted to a total volume of 2.5 liters at 1.25~ consistency
instead of 2~ consistency.
`~ ~
l~S3~;~Z
- 13 - DMK-6219 ~ 6313
Ingredients Amount
glass fibers ~lt8" D-E 670-8; Owens-Corning
Fiberglas) 5
fibrillated polyethylene (grade E-620 Fybrel) 20
cellulose pulp
newsprint pulp 15
softwood pulp tWestvaco) 5
filler
wollastonite (C-l) 35 ~'~
clay ~Klondyke) 20
Total 100
antioxidant (Flectol ~) 0.5
wet strength resin (Kymene 2064)
synthetic rubber latex (Dylex 1187) 20
aluminum sulfate 9
The resulting handsheet was recovered as a rubberized
flooring felt of this invention suitable for use to produce resi-
. lient floor coverings. The felt was tested and found to have a
gauge of about 0.0250 inch.
Example VII
Using substantially the procedure of Example II, a
. handsheet was prepared using the following ingredients.
Ingredients Amount
: glass fibers (1/8" D-E 670-8; Owens-Corning
Fiberglas) 1 .
fibrillated polyethylene (grade E-620 Fybrel)
1153512
- 14 ~ DMK-6219 ~ 6313
Ingredients Amount
cellulose pulp
newsprint pulp 1.5
softwood pulp (Westvaco) 0.5
filler
wollastonite (C~l) 64
clay tKlondyke) 32 __
Total 100
antioxidant (Flectol H)
wet strength resin (Kymene 2064) 0.1
synthetic rubber latex (Dylex 1187) 40
aluminum sulfate 13.2
The resulting handsheet was recovered as a rubberized
flooring felt of this invention suitable for use to produce resi-
lient floor coverings~ The felt was tested and found to have a
gauge of about 0.0303 inch.
Example VIII
Using substantially the procedure of Example II, a
handsheet was prepared using the following ingredients. This slurry
was diluted to a total volume of 2.5 liters at 1.33% consistency
instead of 2% consistency.
Inqredients Amount
-
glass fibers (1/8" D-E 670-8; Owens-Corning
Fiberglas) S .i
fibrillated polyethylene (grade E-620 Fybrel) 10
115351Z
- 15 - DM~-6219 & 6313
Inqredients Amount
cellulose pulp
newsprint pulp 15
softwood pulp (~estvaco) 5
filler
wollastonite (C-l) 45
clay (Klondyke) 20
Total 100
antioxidant (Flectol H) 0.
wet strength resin (Kymene 2G~4)
synthetic rubber latex (Dylex 1187) 20
aluminu~ sulfate 8
The resulting handsheet was recovered as a rubberized
flooring felt of this invention suitable for use to produce resi-
lient floor coverings. The felt was tested and found to have a
gauge of about 0.0236.
Exam~le IX
This example demonstrates the best mode of preparing the
asbestos-free rubberized flooring felt of this invention.
20In~redients Amount
glass fibers (1/8" D-E 670-8: Owens-Corning
Fiberglas) 2.25
fibrillated polyethylene (grade E-620 Fybrel) 2.75 f
cellulose pulp
25unbleached sulfite pulp (P-10) 7.75
softwood pulp (Westvaco) 2.25
11535~z
- 16 - DMK-6219 & 6313
In~redients _mount
filler
wollastonite (P-l) 55
diatomaceous earth 6
clay slurry "Klondyke K~l" 24
Total 100
antioxidant (Flectol H) 0.8
wet strength resins (Kymeme 2064) 0.25
synthetic rubber latex (Dylex 1187) 20
retention aid (Hydraid 5501 - Merck & Co.) 0.06 ?
aluminum sulfate 7.65
To a hydrapulper containing water were added the total
amounts of cellulose pulp, fibrillated polyethylene fibers, filler,
and antioxidant. The contents of the hydrapulper were slurred for
lS about 10 to lS minutes to ensure full dispersion of the ingredients.
The slurry was fed sequentially through Jordan refin-
ers, a holding tank, and into a precipitation tank where it was
diluted with water at 3% consistency and where the total amounts of
glass fibers, synthetic rubber latex, wet strength resin, aluminum
sulfate and ammonia hydroxide were added with stirring for about 3
to 5 minutes. The batch weight of 100 parts of the fiber and filler
in the precipitation tank was 2,500 pounds.
~53S12
- 17 - DMK-6219 & 6313
The total amount of the retention aid was added to the
furnish as it was pumped from the precipitation tank to a conven-
tional Fourdrinier machine where it was formed into a felt of this
invention. The felt was wet pressed to remove excess moisture and
drum dried at a temperature of about 275- to about 300-F.
The resulting felt was recoverd as a rubberized flooring
felt of this invention, and used to produce resilient iloor
covering. The felt was tested and found to have a gauge, after
calenderin~, of about 0.0240 inch.
The following Table I illustrates physical and chemical
property data on the asbestos-free felts of Examples I-IX as com-
pared to representative average property data of conventional prior
art asbestos-containing rubberized felts:
~.;.,
1~53S~LZ
I ~ ~ 11~ D d' ~``1
In c ~ .t~ . co ~ ~ t~ o ~D
O ~1 ~ ~ ~
V ~ O ~ 1~ D O
tU ta O tJ O -t
Q V~ ~4
O p~
~ d'~ ~ t,~1 W
H t~11-)ID ~
O ~ +
Ht`~ . U) a) a~If~ O
H~`I t~
r-l -J O
+
::
H t~
H O ~ ID ~ ~101 ~1 U)
:~tr~~D ~O
O1~ ~ o
O +
~ ~ ~ ~t~U~
o ~ ~t~t,~i o
O ~ +
. ~ U')tD If~
r o 1~
o ~ ~ In t'~t.~l o
O +
I)
ta Il~ G~ t~
X ~t'~l tr~ o ~D
0 ~Ll H O ~D ~ o
O O ~ +
V V
~ tIt~ ~o~ In t,~
H O ID U'ler ~ E-~ O
O ~1~ +
~ V
.~ a
,t~l In t~ . . tn V
H O ~ U')tl7 ~1 0U~ O
Sv
ot~ In N
Il~ ~ O ~ I~ tO tlJ
H ~ tY')I~
olt~ o
o ~ +
a, ,~ rn
c~ v o
',~ ~
14 S --I tJ
t~ U~ ~ 3
,_ tY) -- r
)
~n ~n ~ V ~l
~ op
vt~ ~ o
v v v r~ t~ tav o
t!) ~ ~ ^ ^ V ., ~ _
~. ~ 0~ rn ~ m o
O ri Q t~ z
Q~ ~ VV r r ~a 3 t-
tn U~ U~ "0, ,,, OC S ~ O.~
, ~ ~ v v G~ r~ O
t~ In ~n tn r~ C ~ s ~a C
c c c o o
W ~3 a
~5;:~S~L2
- l9 - DMK-6219 & 6313
The above data indicate that the asbestos-free rubberized
felts of this invention exhibit excellent dimensional stability
under high humidity conditions while possessing acceptable physical
and chemical properties as compared to the prior art asbestos-
containing rubberized felts.
To the asbestos-free rubberized felts with the composition
of this invention can be laminated, using conventional methods, a
conventional decorative surface covering such as a vinyl wear layer
to make a floor covering.
~ j.7 ': .
