U.S. patent application number 11/616963 was filed with the patent office on 2007-08-02 for ceramic oxide fibers.
Invention is credited to Richard M. Flynn, Carol-Lynn Spawn, Larry R. Visser.
Application Number | 20070178304 11/616963 |
Document ID | / |
Family ID | 38228556 |
Filed Date | 2007-08-02 |
United States Patent
Application |
20070178304 |
Kind Code |
A1 |
Visser; Larry R. ; et
al. |
August 2, 2007 |
CERAMIC OXIDE FIBERS
Abstract
Tow of substantially continuous ceramic oxide fibers having a
sizing material. Tows according to the present invention are
useful, for example, for making metal matrix wires.
Inventors: |
Visser; Larry R.; (Oakdale,
MN) ; Flynn; Richard M.; (Mahtomedi, MN) ;
Spawn; Carol-Lynn; (West Lakeland Township, MN) |
Correspondence
Address: |
3M INNOVATIVE PROPERTIES COMPANY
PO BOX 33427
ST. PAUL
MN
55133-3427
US
|
Family ID: |
38228556 |
Appl. No.: |
11/616963 |
Filed: |
December 28, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60755690 |
Dec 30, 2005 |
|
|
|
Current U.S.
Class: |
428/375 |
Current CPC
Class: |
C04B 35/62844 20130101;
B22F 2998/00 20130101; C22C 47/04 20130101; C04B 14/4656 20130101;
C03C 25/32 20130101; C04B 41/009 20130101; C04B 41/4584 20130101;
C04B 2235/5228 20130101; C04B 41/4584 20130101; B22F 2998/00
20130101; C04B 41/4584 20130101; C04B 2235/5264 20130101; Y10T
428/2933 20150115; C04B 41/009 20130101; C04B 35/63488 20130101;
C04B 41/009 20130101; C04B 2235/5224 20130101; C04B 41/4896
20130101; C04B 14/4625 20130101; C04B 35/632 20130101; C04B 41/48
20130101 |
Class at
Publication: |
428/375 |
International
Class: |
D02G 3/00 20060101
D02G003/00 |
Claims
1. A tow of substantially continuous ceramic oxide fibers, wherein
each ceramic oxide fiber has an outer surface, wherein at least a
portion of the outer surfaces of at least some of the ceramic oxide
fibers have a sizing material therein, and wherein the sizing
material comprises a composition represented by the formula:
R'O--(RO).sub.n--H, wherein: R' is selected from C.sub.xH.sub.2x+1,
wherein x is 1-8 or --H; R is selected from the group consisting of
--(C.sub.yH.sub.2y)--, wherein y is 1-4, and
--CH.sub.2--O--(CH.sub.2).sub.m--, wherein m=2-5; and n is chosen
such that the number average molecular weight is in a range from
500 g/mole to 7,000,000 g/mole.
2. The tow according to claim 1, wherein the substantially
continuous ceramic oxide fibers are crystalline.
3. The tow according to claim 1, wherein the substantially
continuous ceramic oxide fibers are selected from the group
consisting of crystalline alumina fibers, crystalline
aluminosilicate fibers, crystalline aluminoborosilicate fibers, and
combinations thereof.
4. The tow according to claim 1, wherein n is chosen such that the
number average molecular weight is in a range from 500 g/mole to
3,000,000 g/mole.
5. The tow according to claim 1, wherein n is chosen such that the
number average molecular weight is in a range from 500 g/mole to
400,000 g/mole.
6. A method of providing the tow of substantially continuous
ceramic oxide fibers according to claim 1, the method comprising:
providing a tow of substantially continuous ceramic oxide fibers,
wherein each ceramic oxide fiber has an outer surface; coating at
least a portion of the outer surfaces of at least some of the
ceramic oxide fibers with an aqueous-based sizing material, wherein
the sizing material comprises a composition represented by formula:
R.sub.1'O'(R.sub.1O).sub.n1--H, wherein: R.sub.1' is selected from
C.sub.x1H.sub.2x1+1, wherein x1 is 1-8 or --H; R.sub.1 is selected
from the group consisting of --(C.sub.y1H.sub.2y1)--, wherein
y.sub.1 is 1-4, and --CH.sub.2--O--(CH.sub.2).sub.m1--, wherein
m.sub.1=2-5; and wherein n is chosen such that the number average
molecular weight is in a range from 500 g/mole to 7,000,000 g/mole;
and removing at least a portion of the water.
7. The method according to claim 6, wherein the aqueous-based
sizing material is a solution.
8. The method according to claim 6, wherein the aqueous-based
sizing material is an emulsion.
Description
[0001] This application claims the benefit of U.S. Provisional
Application No. 60/755,690, filed Dec. 30, 2005, the disclosure of
which is incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
[0002] The present invention related to ceramic oxide fibers, more
particularly to ceramic oxide fibers with sizing material.
BACKGROUND
[0003] In general, substantially continuous ceramic oxide fibers
are known. Examples include polycrystalline alumina fibers such
those marketed by the 3M Company, St. Paul, Minn., under the trade
designation "NEXTEL 610", aluminosilicate fibers such as those
marketed by the 3M Company under the trade designations "NEXTEL
440", "NEXTEL 550", and "NEXTEL 720", and aluminoborosilicate
fibers such as those marketed by the 3M Company under the trade
designation "NEXTEL 312". These continuous fibers are incorporated
into various metal matrix composites (e.g. aluminum and titanium)
and polymer matrix composites (e.g. epoxy) to reinforce and
strengthen these composites.
[0004] It is desirable to maintain the strength of the composites.
The composite strengths are increased by having continuous fibers
with as few discontinuities as possible. One source of
discontinuities comes when the continuous fiber is unwound from a
spool and the fiber breaks or sheds, commonly called "strip back."
It is desirable to eliminate, minimize, or at least reduce these
discontinuities produced during the unwind process thus allowing
for the production of increased strength metal and polymer matrix
composites.
SUMMARY
[0005] In one aspect, the present invention provides a tow of
substantially continuous refractory (i.e., maintains its integrity
or usefulness at temperatures in a range of 820.degree. C. to
1400.degree. C.) ceramic oxide fibers, wherein each ceramic oxide
fiber has an outer surface, and wherein at least a portion of the
outer surfaces of at least some of the ceramic oxide fibers have a
sizing material therein. The sizing material comprises a
composition represented by the formula: R'O--(RO).sub.n--H, wherein
R' is selected from C.sub.xH.sub.2x+1, wherein x is 1-8 or --H; R
is selected from the group consisting of
--(C.sub.yH.sub.2y)--(which may be linear or branched), wherein y
is 1-4, and --CH.sub.2O--(CH.sub.2).sub.m--, wherein m=2-5; and
wherein n is chosen such that the number average molecular weight
is in a range from 500 g/mole to 7,000,000 g/mole. Typically, the
number average molecular weight is in a range from 500 g/mole to
3,000,000 g/mole (in some embodiments, in a range from 500 g/mole
to 600,000 g/mole, 500 g/mole to 400,000 g/mole, 500 g/mole to
300,000 g/mole, or even 4,000 g/mole to 40,000 g/mole). Typically
the sizing material provides an add-on weight in a range from 0.5
to 10 percent by weight.
[0006] "Continuous fiber" refers to fiber having a length that is
at least 30 meters. In some embodiments, the refractory fibers are
crystalline (i.e., exhibits a discernible X-ray powder diffraction
pattern). In some embodiments, the fiber is at least 50 (in some
embodiments, at least 55, 60, 65, 70, 75, 80, 85, 90, 95, 96, 97,
98, 99, or even 100) percent by weight crystalline. In some
embodiments, the refractory ceramic oxide fibers (including
crystalline ceramic oxide fibers) comprise at least one of (a) at
least 40 (in some embodiments, at least 50, 60, 65, 70, 75, 80, 85,
90, 95, 96, 97, 98, 99, or even 100) percent by weight
Al.sub.2O.sub.3, based on the total oxide content of each
respective fiber, or (b) not more than 40 (in some embodiments, not
more than 35, 30, 25, 20, 15, 10, 5, 4, 3, 2, 1, 0.5, 0.1, or even
zero) percent by weight collectively SiO.sub.2, Bi.sub.2O.sub.3,
B.sub.2O.sub.3, P.sub.2O.sub.5, GeO.sub.2, TeO.sub.2,
As.sub.2O.sub.3, and V.sub.2O.sub.5, based on the total oxide
content of each respective fiber.
[0007] The sizing material has been observed to provide lubricity
and to protect the fiber strands during handling. For some uses of
the fiber, for example, as reinforcement in a metal matrix
composite, the sizing is typically removed during processing prior
to applying metal to the fiber. The sizing may be removed, for
example, by burning the sizing away from the fibers.
DESCRIPTION
[0008] Examples of suitable refractory ceramic oxide fibers include
alumina fibers, aluminosilicate fibers, aluminoborate fibers,
aluminoborosilicate fibers, zirconia-silica fibers, and
combinations thereof. Examples of suitable crystalline refractory
ceramic oxide fibers include alumina fibers, aluminosilicate
fibers, aluminoborate fibers, aluminoborosilicate fibers,
zirconia-silica fibers, and combinations thereof. Examples of
suitable non-crystalline, refractory ceramic oxide fibers include
aluminoborosilicate fibers, zirconia-silica fibers, and
combinations thereof. In some embodiments, it is desirable for the
fibers to comprise at least 40 (in some embodiments, at least 50,
60, 65, 70, 75, 80, 85, 90, 95, 96, 97, 98, 99, or even 100)
percent by volume Al.sub.2O.sub.3, based on the total volume of the
fiber. In some embodiments, it is desirable for the fibers to
comprise in a range from 40 to 70 (in some embodiments, in a range
from 55 to 70, or even 55 to 65) percent by volume Al.sub.2O.sub.3,
based on the total volume of the fiber.
[0009] The partially crystalline fibers can comprise a mixture of
crystalline ceramic and amorphous phases (i.e., a fiber may contain
both crystalline ceramic and amorphous phases). Typically, the
continuous ceramic fibers have an average fiber diameter of at
least about 5 micrometers, more typically, in a range from about 5
micrometers to about 20 micrometers; in some embodiments, in a
range from about 5 micrometers to about 15 micrometers.
[0010] Alumina fibers are described, for example, in U.S. Pat. Nos.
4,954,462 (Wood et al.) and 5,185,299 (Wood et al.). In some
embodiments, the alumina fibers are polycrystalline alpha alumina
fibers, and comprise, on a theoretical oxide basis, greater than 99
percent by weight Al.sub.2O.sub.3 and 0.2-0.5 percent by weight
SiO.sub.2, based on the total weight of the alumina fibers. In
another aspect, some desirable polycrystalline, alpha alumina
fibers comprise alpha alumina having an average grain size of less
than 1 micrometer (or even, in some embodiments, less than 0.5
micrometer). In another aspect, in some embodiments,
polycrystalline, alpha alumina fibers have an average tensile
strength of at least 1.6 GPa (in some embodiments, at least 2.1
GPa, or even, at least 2.8 GPa), as determined according to the
tensile strength test described in U.S. Pat. No. 6,460,597
(McCullough et al.). Exemplary alpha alumina fibers are marketed
under the trade designation "NEXTEL 610" by 3M Company, St. Paul,
Minn.
[0011] Aluminosilicate fibers are described, for example, in U.S.
Pat. No. 4,047,965 (Karst et al). Exemplary aluminosilicate fibers
are marketed under the trade designations "NEXTEL 440", "NEXTEL
550", and "NEXTEL 720" by 3M Company of St. Paul, Minn.
[0012] Aluminoborate and aluminoborosilicate fibers are described,
for example, in U.S. Pat. No. 3,795,524 (Sowman). Exemplary
aluminoborosilicate fibers are marketed under the trade designation
"NEXTEL 312" by 3M Company.
[0013] Zirconia-silica fibers as described, for example, in U.S.
Pat. No. 3,709,706 (Sowman).
[0014] Tows are known in the fiber art and typically include a
plurality of (individual) generally untwisted fibers (typically at
least 100 fibers, more typically at least 400 fibers). In some
embodiments, tows comprise at least 780 individual fibers per tow,
and in some cases, at least 2600 individual fibers per tow, or at
least 5200 individual fibers per tow. Tows of various ceramic
fibers are available in a variety of lengths, including 300 meters,
500 meters, 750 meters, 1000 meters, 1500 meters, and longer. The
fibers may have a cross-sectional shape that is circular,
elliptical, or dogbone.
[0015] A tow(s) according to the present invention can be made by a
method comprising: [0016] providing a tow of substantially
continuous ceramic oxide fibers, wherein each ceramic oxide fiber
has an outer surface; [0017] coating at least a portion of the
outer surfaces of at least some of the ceramic oxide fibers with an
aqueous-based sizing material; and [0018] removing at least a
portion of the water. The aqueous-based sizing material comprises a
composition represented by formula: R'O--(RO).sub.n--H, wherein R'
is selected from C.sub.xH.sub.2x+1, wherein x is 1-8 or --H; R is
selected from the group consisting of --(C.sub.yH.sub.2y)--,
wherein y is 1-4, and --CH.sub.2--O--(CH.sub.2).sub.m--, wherein
m=2-5; and wherein n is chosen such that the number average
molecular weight is in range from 500 g/mole to 7,000,000 g/mole.
Typically, the number average molecular weight is in a range from
500 g/mole to 3,000,000 g/mole (in some embodiments, in a range
from 500 g/mole to 600,000 g/mole, 500 to 400,000 g/mole, 500
g/mole to 300,000 g/mole, or even 4,000 g/mole to 40,000
g/mole).
[0019] Suitable sizing materials include poly(tetramethylene oxide)
(available, for example, from Invista, Wichita, Kans., under the
trade designation "TERATHANE 2900" (number average molecular weight
2,900 g/mole)), polyethylene glycol (available, for example, from
Clariant GmbH Functional Chemicals Division, Frankfurt, Germany,
under the trade designation "POLYGLYKOL 35000" (number average
molecular weight 35,000 g/mole) "POLYGLYKOL 20000" (number average
molecular weight 20,000 g/mole), "POLYGLYKOL 4000S" (number average
molecular weight 4000 g/mole), "POLYGLYKOL 8000S" (number average
molecular weight 8000 g/mole), "POLYGLYKOL 1500S" (number average
molecular weight 1500 g/mole)), and high number average molecular
weight polyethylene oxide materials (available, for example, from
Dow Chemical, Midland, Mich., under the trade designation "POLYOX
WSR N-3000" (number average molecular weight 400,000 g/mole),
"POLYOX WSR N-750" (number average molecular weight 300,000 g/mole)
and "POLYOX WSR-301" (number average molecular weight 4,000,000
g/mole).
[0020] Water soluble sizing materials such as poly(ethylene
glycols) may be dissolved in water to provide the aqueous-based
sizing material. The concentration of water soluble sizing
materials in the aqueous-based sizing material can be chosen as
desired. Typically, such aqueous-based sizing materials are made by
combining the water soluble sizing material and water to provide an
aqueous-based sizing material comprising, by weight, in a range
from 1 to 30 percent; in some embodiments, in a range from 1 to 10
percent water soluble sizing materials.
[0021] When using materials that are not soluble in water (e.g.,
poly(tetramethylene oxide)), the aqueous-based sizing material is
emulsified. Such emulsions can be made with the use of surfactants.
Typically, the amount of surfactant used to make the emulsion is in
a range from 0.5 to 10% percent by weight of the material to be
emulsified, although amounts of surfactant outside of this range
may also be useful. Typically, the emulsion is in a range from 5 to
50 percent by weight solids. If the percent solids of the emulsion
is higher than desired, it can be diluted with water.
[0022] In general sizing materials have been observed in the art to
provide (a) sufficient strength to bind the fibers in the tow
together into a cohesive bundle, (b) good lubricating/release
characteristics so that the fibers/tows do not stick to equipment
and thread guides, and have lubrication to reduce friction and
adherence to surfaces that contact the tow during handling, and (c)
ability to be rapidly oxidized without leaving residue (e.g.,
carbon-containing residue) on the fiber at relatively low or
moderate temperatures, (e.g., 700.degree. C.). The later is
particularly desirable in embodiments of metal matrix wire making
process, wherein the sizing material is typically easily removed in
a relatively short period of time (e.g., less than 30 seconds) by
heating the tows at the relatively low or moderate temperatures.
Removal of the sizing material is enhanced by pumping an oxidizing
gas (e.g., air) into the region where the sizing material is being
oxidized. Although the desired flow rates of the oxidizing gas will
depend on the particular circumstances (e.g., the particular sizing
material, the amount of sizing material, the fiber speed, the
temperature, the length of the hot zone, etc.), exemplary flow
rates include flow rates in a range from about 5 liters/min. to
about 10 liters/min.
[0023] Further, the sizing material specified for the present
invention can be effectively applied to fiber (e.g., fiber at a
temperature in a range of about 15.degree. C.-200.degree. C.),
including applying the sizing material to fiber as it exits the
sintering furnace.
[0024] Tows according to the present invention are useful, for
example, for making metal matrix composite wires. Exemplary metal
matrix materials include aluminum, zinc, tin, magnesium, and alloys
thereof (e.g., an alloy of aluminum and copper).Techniques for
making metal matrix composite wires are known in the art, and
include those discussed, for example, in U.S. Pat. Nos. 5,501,906
(Deve), 6,180,232 (McCullough et al.), 6,245,425 (McCullough et
al.), 6,336,495 (McCullough et al.), 6,544,645 (McCullough et al.),
6,447,927 (McCullough et al.), 6,460,597 (McCullough et al.),
6,329,056 (Deve et al.), 6,344,270 (McCullough et al.), 6,485,796
(Carpenter et al.), 6,559,385 (Johnson et al.), 6,796,365
(McCullough et al.), 6,723,451 (McCullough et al.), 6,692,842
(McCullough et al.), 6,913,838 (McCullough et al.), 7,093,416
(Johnson et al.), and 7,131,308 (McCullough et al.); U.S.
publication No. 2005/0181228-A1; U.S. application having Ser. No.
10/403,643, filed Mar. 31, 2003, U.S. application having Ser. No.
10/870,263, filed Jun. 17, 2004, and U.S. application having Ser.
No. 10/870,401, filed Jun. 17, 2004, the disclosures of which are
incorporated herein by reference for their teachings on making and
using metal matrix composite wires.
[0025] Embodiments of metal matrix composite wires made from sized
fibers according to the present invention have been observed to be
stronger (e.g., about 2-8%) as compared to the metal matrix
composite wires made fibers not including the sizing material
utilized in the present invention (including fibers sized with
other sizing materials).
[0026] Advantages and embodiments of this invention are further
illustrated by the following examples, but the particular materials
and amounts thereof recited in these examples, as well as other
conditions and details, should not be construed to unduly limit
this invention. All parts and percentages are by weight unless
otherwise indicated.
EXAMPLES
Example 1
[0027] 52.2 kg (115 lbs.) of solid poly(tetramethylene oxide) (2900
g/mole number average molecular weight; obtained from INVISTA,
Wichita, Kans., under the trade designation "TERATHANE 2900") was
melted by placing it an oven heated to 60.degree. C. (140.degree.
F.) overnight. A 284 liter (75 gallon) glass-lined water-jacketed
receiver, fitted with an agitator, was brought to 60.degree. C.
(140.degree. F.). The agitator was set at 80 rpm, and the reactor
charged with the molten poly(tetramethylene oxide) ("TERATHANE
2900"). 52.2 kg (115 lbs.) of ethyl acetate (obtained from
Sigma-Aldrich, Milwaukee, Wis.) was then added to the reactor,
followed by 8.7 kg (19.1 lbs.) of
octadecylmethyl(polyoxyethylene[15]) ammonium chloride (obtained
from Akzo Nobel, Chicago, Ill., under the trade designation
"ETHOQUAD 18/25").
[0028] A second 284 liter (75 gallon) glass-lined water-jacketed
reactor, fitted with an agitator (80 rpm) was brought to 60.degree.
C. (140.degree. F.). 114 kg (253 lbs.) of de-ionized water;
filtered through a 0.2 micron filter (obtained from C.C. Day Co.,
Minneapolis, Minn.; part No. 25-10110-002-01-WG), was added to the
reactor. The agitator speed was increased to 100 rpm. Once the
temperature of both the reactor and the receiver were at 60.degree.
C. (140.degree. F.), nitrogen pressure on the receiver was
increased to allow the contents from the first reactor to flow into
the second reactor.
[0029] The water inlet connection of a two stage homogenizer (type
70-M-310-TBS; obtained from Manton-Gaulin Manufacturing Co.,
Everett, Mass.; flushed with de-ionized water) was attached to the
inlet port of the homogenizer with a tube and a 0.2 micron filter
(obtained from C.C. Day Co.; part No. 25-10110-002-01-WG). A 25
micrometer filter cartridge (obtained from C.C. Day Co.; part No.
SWF-25-RYA10T) was attached between the outlet of the reactor and
the inlet connection of the homogenizer. The operating pressure of
the homogenizer was set at 20.7 MPa (3000 psig), and the mixture
pumped through at 20.7 MPa (3000 psig). Once the output from the
homogenizer was a bluish-white emulsion with no solids, the output
was directed into 208 liter (55 gallon) drums with polyethylene
liner.
[0030] The bluish-white emulsion was run through the homogenizer a
second time, and the output again directed into 208 liter (55
gallon) drums with polyethylene liners. The first reactor was
fitted with a condensate decanter, flushed and cleaned with
de-ionized water before the bluish-white emulsion was charged into
the (clean) reactor. The agitator was brought to 60 rpm, and the
jacket temperature set to 38.degree. C. (100.degree. F.). The
reactor was then closed and a vacuum (8 kPa (60 mm Hg)) drawn on
the contents. As ethyl acetate distillate collected in the
decanter, the vacuum was slowly increased to (5.3 kPa (40 mm Hg),
to minimize excessive foaming. When 45.4 kg (100 lbs.) of ethyl
acetate has been collected, the distillation was terminated, the
reactor cooled to 21.degree. C. (70.degree. F.), and the resulting
emulsion drained through a 25 micrometer cartridge filter (obtained
from C.C. Day Co.; part No. SWF-25-RYA10T), into 19 liter (5
gallon) polyethylene-lined pails and covered.
[0031] The resulting emulsion was coated onto tows of alpha alumina
fibers (10,000 denier; marketed by the 3M Company, St. Paul, Minn.,
under the trade designation "NEXTEL CERAMIC OXIDE FIBER 610"*)
using a coating station according to the following procedure. The
"TERATHANE 2900" emulsion, as described above, was diluted with
deionized water to a 5% "TERATHANE 2900" emulsion, and placed into
the sizing tray of the coating station. The sizing roll picks up
the emulsion by immersion in the coating tray. The sizing was
coated onto one fiber tow by passing the tow over the sizing roll,
at a rate of 34.7 m/min. (114 ft./min.). The speed of the sizing
application roll was set to provide 1.5% sizing net coating weight.
The coated fiber tow was wrapped around drying cans (15 cm (6 inch)
diameter chrome-coated steel rolls heated to 100.degree. C.) twelve
times and then wound onto cardboard cylinders. * The fiber used was
unsized prior to application of the emulsion. The fiber marketed by
3M typically is sold with a sizing thereon. Such sizing can
typically be removed by heating the fiber to at least 700.degree.
C. for 5 minutes.
[0032] The amount of sizing applied to the fiber tow was determined
by weighing a one meter (3 ft) piece of sized tow (w.sub.initial),
placing the piece of sized tow in a furnace at 700.degree. C. for 5
minutes, removing the sample from the furnace, allowing the to cool
to room temperature, and then reweighing the sample (w.sub.final).
The weight percent sizing applied (S.sub.w) was calculated using
the following formula: Sw = ( w initial - w final ) w initial
.times. 100 ##EQU1##
[0033] The add-on weight of the dried sizing material was about 2%
by weight. The sizing material was visually observed to have
cleanly burned-off the fibers.
Example 2
[0034] A 4 liter (1 gallon) glass jar was charged with 2858 grams
of de-ionized water. An overhead mixer fitted with a Cowl's blade
mixer was inserted into the glass jar, brought to 500 rpms, and 150
grams of polyethylene glycol (300,000 g/mole number average
molecular weight; obtained from Dow Chemical, Midland Mich., under
the trade designation "POLYOX WSR N-750") slowly added (over about
30 minutes) at the vortex created by the Cowl's blade. The
resulting mixture was placed on a platform shaker table (obtained
from New Brunswick Scientific Co. Inc., Edison, N.J., under the
trade designation "INNOVA 2000") for about 60 hours.
[0035] The resulting solution was coated onto tows of alumina
fibers as described in Example 1. The add-on weight of the dried
sizing material was about 1% by weight. The sizing material was
visually observed to have cleanly burned-off the fibers.
Example 3
[0036] Example 3 was prepared as described for Example 2, except 3
grams of polyethylene glycol (1500 g/mole number average molecular
weight; obtained from Sigma-Aldrich, Milwaukee, Wis., under the
trade designation "PEG 1500") was added to the deionized water
before the polyethylene glycol.
[0037] The resulting solution was coated onto tows of alumina
fibers as described in Example 1. The add-on weight of the dried
sizing material was about 1.5% by weight. The sizing material was
visually observed to have cleanly burned-off the fibers.
Example 4
[0038] Example 4 was prepared as described for Example 2, except
150 grams of polyethylene glycol (20,000 g/mole number average
molecular weight; obtained from Sigma-Aldrich, under the trade
designation "PEG 20,000") was substituted for the polyethylene
glycol. The resulting material was a clear solution.
[0039] The resulting solution was coated onto tows of alumina
fibers as described in Example 1. The add-on weight of the dried
sizing material was about 1% by weight. The sizing material was
visually observed to have cleanly burned-off the fibers.
Example 5
[0040] A 3.8 liter (one gallon) glass jar was charged with 2850
grams of de-ionized water. An overhead mixer fitted with a Cowl's
blade mixer was inserted into the glass jar, brought to 500 rpms,
and 150 grams of polyethylene glycol (35,000 g/mole number average
molecular weight; obtained from Clariant Corporation, Mount Holly,
N.C. under the trade designation "POLYGLYKOL 35000") slowly added
(over about 10 minutes) at the vortex created by the Cowl's blade.
The resulting material was a clear, colorless solution.
[0041] The resulting solution was diluted and coated onto tows of
alumina fibers as described in Example 1. The add-on weight of the
dried sizing material was about 1% by weight. The sizing material
was visually observed to have cleanly burned-off the fibers.
Example 6
[0042] A 6 liter stainless steel beaker was charged with 2970 grams
of de-ionized water and a mixer (Model # ME100L obtained from
Charles Ross & Son Co. Hauppauge, N.Y.; under the trade
designation "ROSS MIXER EMULSIFIER") was inserted into the beaker.
The mixer was brought to 5000 rpm, and 30 grams of polyethylene
glycol (4,000,000 g/mole number average molecular weight; obtained
from Dow Chemical under the trade designation "POLYOX WSR-301") was
slowly added (over about 15 minutes) to the water. The resulting
mixture was placed on a shaker table (see Example 2; at 125 rpm)
for 12 hours.
[0043] The resulting solution was coated onto tows of alumina
fibers as described in Example 1. The add-on weight of the dried
sizing material was about 1.5% by weight. The sizing material was
visually observed to have cleanly burned-off the fibers.
Example 7
[0044] A 6 liter stainless steel beaker was charged with 2985 grams
of de-ionized water. An overhead mixer fitted with a Cowl's blade
mixer was inserted into the glass jar, brought to 500 rpms, and 15
grams of polyethylene glycol (7,000,000 g/mole number average
molecular weight; obtained from Dow Chemical under the trade
designation "POLYOX WSR-303") slowly added (over about 30 minutes)
to the water. The resulting mixture was placed on a shaker table
(see Example 2; at 125 rpm) for 12 hours.
[0045] The resulting solution was coated onto tows of alumina
fibers as described in Example 1. The add-on weight of the dried
sizing material was about 2% by weight. The sizing material was
visually observed to have cleanly burned-off the fibers.
Example 8
[0046] A 6 liter stainless steel beaker was charged with 2850 grams
of de-ionized water, and a mixer ("ROSS MIXER EMULSIFIER") fitted
with a Ross screen head was inserted into the beaker. The mixer was
brought to 5000 rpm, and the water heated to about 60.degree. C.,
30 grams of polyethylene glycol ("POLYOX WSR N-750") was slowly
added (over about 15 minutes) to the water. The resulting mixture
was placed on a conventional roller table (at about 40 rpm) for 12
hours, yielding a cloudy solution.
[0047] The resulting solution was coated onto tows of alumina
fibers as described in Example 1. The add-on weight of the dried
sizing material was about 1.3% by weight. The sizing material was
visually observed to have cleanly burned-off the fibers.
Example 9
[0048] A 6 liter stainless steel beaker was charged with 2850 grams
of de-ionized water and a mixer ("ROSS MIXER EMULSIFIER") fitted
with a Ross disperser blade was inserted into the beaker. The mixer
was brought to 5000 rpm, and the 150 grams of polyethylene glycol
(400,000 number average MW; obtained from Dow Chemical under the
trade designation "POLYOX WSR N-3000") was slowly added (over about
30 minutes) to the water. This resulted in a clear solution.
[0049] The resulting solution was coated onto tows of alumina
fibers as described in Example 1. The add-on weight of the dried
sizing material was about 1.5% by weight. The sizing material was
visually observed to have cleanly burned-off the fibers.
Example 10
[0050] Example 10 was prepared as described for Example 3, except
polyethylene glycol (4000 g/mole number average molecular weight;
obtained from Clariant Corporation under the trade designation
"POLYGLYKOL 4000S") was added to the deionized water instead of the
"PEG 1500" polyethylene glycol.
[0051] The resulting solution was coated onto tows of alumina
fibers as described in Example 1. The add-on weight of the dried
sizing material was about 1.3% by weight. The sizing material was
visually observed to have cleanly burned-off the fibers.
Example 11
[0052] Example 11 was prepared as described for Example 10, except
polyethylene glycol (8000 g/mole number average molecular weight;
obtained from Clariant Corporation under the trade designation
"POLYGLYKOL 8000S") was added to the deionized water instead of the
"POLYGLYKOL 4000S" polyethylene glycol.
[0053] The resulting solution was coated onto tows of alumina
fibers as described in Example 1. The add-on weight of the dried
sizing material was about 2% by weight. The sizing material was
visually observed to have cleanly burned-off the fibers.
Example 12
[0054] Example 12 was prepared as described for Example 2, except
147 grams "POLYOX WSR N-750" and 3.02 grams of "PEG-1500" was added
to the deionized water instead of 150 grams of the "POLYOX WSR
N-750" polyethylene glycol. The add-on weight of the dried sizing
material was about 1.2% by weight. The sizing material was visually
observed to have cleanly burned-off the fibers.
[0055] Various modifications and alterations of this invention will
become apparent to those skilled in the art without departing from
the scope and spirit of this invention, and it should be understood
that this invention is not to be unduly limited to the illustrative
embodiments set forth herein.
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