Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to the field oE sizing
compositions for glass fibers, and more particularly, for
glass fiber gun roving, and to glass ibers coated therewi-th.
Glass fibers used as reinforcing elements in poly-
meric or resinous matrix materials are usually coa-ted with a
very ligh-weight size coating which serves to protect the
fibers from damage by abrasion during processing, handling
and/or use, -to bind the individual Eibers into more-or-less
tightly integrated multi-Eiber bundles or strands, and/or to
enhance the reinforcing in-teraction between the fibers and
the resinous matrix in which they are imbedded as reinforcing
elements. Such sizing compositions are frequently applied to
the glass fibers at -the time of their initial production,
which is ordinarily by pulling a p].urality of streams of
molten glass issuing from a reservoir thereof through a sub-
stantially corresponding plurality of sui-table orifices so as
to attenuate these streams to the desired Eiber diameter as
they cool and solidify. The sizing composition is typically
applied to the individual fibers in-line as soon ~s they have
cooled sufficiently below the solidification temperature,
which cooling may be accelerated by wetting the newly solidi-
fied but still hot
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fibers with water. Liquid sizing compositions are applied
in such situations by spraying, by drawing the fibers
across a suitable roll, belt, apron, pad, etc. wet with the
liquid sizing composition, or other conventional liquid coat-
ing methods. After the liquid sizing composition has beenapplied to the individual advancing glass fibers, they are
typically brought together while still at least partially
wet with the liquid sizing composition into one or more
multifiber bundles or strands, which may be collected into a
:suitable package for further processing, storage and/or
shipment, as by winding onto a rotation collet. The wet
fibers or strands are normally dried, before and/or after
such collection, to deposit the non-volatile residue of the
liquid sizing composition on-to the surfaces of the fibers.
Liquid sizing compositions suitable for such
application to glass fibers ordinarily are dilute solutions,
dispersions and/or emulsions, often in aqueous media, of a
film-forming polymer or resin, a lubricant and a coupling
agent. Other components, such as anti-static agents
(especially where the sized glass fibers are to be chopped
into short lengths while dry), emulsifying or solubilizing
agents, viscosity modifying agents, etc. have also sometimes
been incorporated in such liquid sizing compositions.
One of the uses for glass fibers i5. as gun roving,
which desirably consists of a plurality of continuous strands
weakly integrated together, with each strand consisting of a
plurality of individual glass fibers tightly integrated to-
gether by the size coating on the fibers. Such gun roving is
used by feeding it through a suitable chopper incorporated in
or closely associated with a suitable gun for spraying a fluid
resin composition together with the chopped roving onto a
mold or other suitable target so that the chopped roving or
pieces of strand separated therefrom becomes imbedded in the
fluid resin, which will subsequently be solidified by cooling
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and/or by curing by chemical reaction. Representative
equipment and corresponding methods for such use of ylass
fibers in gun roving are described in U.S. Patent No.
3,111,440, entitled DEVICES ~ND METIIODS ~OR APPLYING S~ANDS,
issued November 19, 1963 or an invention of William II.
Prentice. Typically, the chopped pieces are from abou-t 1.27
cm to about 5.0~ cm (1/2 to about 2 inches) in length.
Glass fiber gun roving has heretofore been coated
with liquid sizing composltions containing Werner-type chrome
complexes, such as methacrylato chromic chloride, which is
thought to function in part at least as a glass-resin
coupling agent, although such chrome complexes have sometimes
been used togetller with conven-tional organosilane glass-resin
coupling agents. Before the present inventioIl it had not
been though possible to achieve a satisactory balance of
desirable properties in glass fiber gun roving wi-thout the
inclusion of a chrome complex in the sizing composition for
the constituen-t fibers thereof, and particularly to achieve a
desirable ease and completeness of chopping in conventional
equipment, while also achieveing desirably rapid an~ complete
wetting of the chopped reinforcement by the liquid ma-trix
resin composition and providing a desirable enhancement of the
physical properties of the resinous matrix while holding the
generation of ~uzz, from breakage of fibers during processing
of the continuous strand or roving, and "fly", i.e., static-
dispersed pieces of chopped roving strand or partially or
fully fibrillated residues thereof accompanying the chopping
and spraying at the gun, to desirably low incidence.
Accordingly, the invention provides a substantially
chrome-free aqueous sizing composition for glass fiber gun
roving which comprises (A) a mixture of emulsified film-
forming polymers comprising a polymer of vinyl ace-tate and
ethylene, a polymer of vinyl acetate and an epoxy-functional
vinyl monomer, and an
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unsaturated polyester resin; (B) titanium acetyl acetonate;
(C) a silylated polyaminopolyamide hydrochloride or hydrolysate
thereof; (D) a cationic lubricant; and (E~ 3-methacryloxy-
propyltrimethoxysilane or hydrolysa-te thereof.
The emulsified film-forming polymer components o~
the present invention can be any emulsified polymers oE -the
types called for which will coalesce to form coherent films,
and which preferably will so coalesce at normal ambient work-
place temperatures. A small amount of suitable plasticizer to
aid in such coalescence, of which many are known and available,
may be blended and co-emulsiied with one or more ~f the
polymers, if desired, but it is ordinarily found possible and
preferable to select polymers which do not require such addi-
tives to exhibit advantageous characteristics in use.
However, it is none-theless desirable and preferred to include
a latently reactive unsaturated plasticizer with the unsatur-
ated polyester resin to ultima-tely react with -this unsa-turated
polyester and with an unsaturated polyester matrix resin to
more intimately bond the glass fibers to each other and to the
matrix in which they are embedded as reinforcing elements.
A particularly suitable emulsified polymer of vinyl
acetate and ethylene is available as Airflex 410 (TM/Air
Products and Chemicals Co.), an aqueous emulsion containing
about 55% by weight non-vola-tiles comprising a vinyl acetate-
ethylene copolymer having a glass transition temperature of
about 2C. non-ionically emulsified as particles of about
0.3~m average diameter.
A particularly suitable emulsified polymer of vinyl
acetate and an epoxy-functional vinyl monomer is available
30 as Resyn 25-1971 (TM/National S-tarch and Chemical Corp.), an
aqueous emulsion containing about 54.5-~1% by weight non-
volatiles comprising a copolymer of vinyl acetate with about
2% by weight of glycidyl methacrylate non-ionically emulsified.
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A particularly suitable unsaturated polyester resin
is available as MR70D (TM/Uni-ted States Ste~l Corp.), an
approximately 60:40 by weight blend of an unsatura-ted poly-
ester and diallyl phthala-te, a latently reactive plasticizer,
which was non-ionically emulsified to form an aqueous emulsion
containing about 59~ by weight non-volatiles and designated
PE-700.
A particularly suitable titanium acetylacetona-te is
available as Tyzor AA (TM/E.I. duPont de Nemours, Inc.), a
75~ by weight solution or dispersion of bis(2, 4-pentanedio-
na-te-0,0')bis(2-propan~lato) titanium in isopropanol.
A particularly suitable silylated polyamino poly-
amide hydrochloride is available as Y-g567 (TM/Union Carbide
Corp.), an 80% by weight dispersion or solution in methanol
of a hydrochloric acid salt of
CH3 ~NHCH2CH2N(CH3)CH2CH2C(=0~ x
NHcH2cH2NcH2cH2c ( =O ) ~ NHcH2cH2N~cH3
CH2CH2CH2si(OCH3)3 y
where x + ~ is a number from about 3 to about 10. Such
materials and their preparation are described in detail in
U.S. Patent No~ 3,746,738, entitled SILICON CONTAINING POLY-
AZIMIDES issued July 17, 1973 for an inven-tion of Enrico J.
Pepe and James G. Marsden.
A particularly suitable cationic lubricant is a
weak acid salt of a partial fatty amide of a polyamine such
as Emery 6760 U (TM/Emery Industries, Inc.), a 65~ by weight
aqueous solution or dispersion of an ace-tic acid salt of a
partial amide of mixed fatty acids having about 6 to 8 carbon
atoms with a polyethylenamine. The same material has also
been available undiluted as Emery 6717.
A particularly suitable 3-methacryloxyproplytri-
methoxysilane is available in a blend with a proprietary sta-
bilizer as A-174 (TM/Union Carbide Corp.). The silane is
preferably hydrolyzed in
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dilute aqueous weak acid before use.
While the proportions of the various components of
the aqueous sizing compositions of the invention are not
narrowly critical, it is preferred that they be within about
the following ranges:
Preferred
Component Weight %
Emulsified polymer of vinyl 1-5
acetate and ethylene
Emulsified polymer of vinyl 1-5
acetate and an epoxy-functional
vinyl monomer
Emulsified unsa-turated 0.5-1.5
polyester resin
Titanium acetyl acetonate 0.5-1.5
Silylated polyaminopolyamide0.01-0~2
hydrochloride
Cationic lubricant 0.005-0.1
3-methacryloxypropyltrimethoxy 0.005-0.1
silane
Other components can be included, if desired, but
in order to ensure that the advantages of the invention are
realized, it is preferred that other components be omitted
unless it is found that no significant diminution of those
advantages results from the inclusion -thereof. In par-
ticular, since it is a principal object of the invention
to provide a chrome-free sizing composition for glass fiber
gun roving, no chromium compounds or complexes should be
included in sizing compositions of the invention. However,
since some of the components, e.g. the titanium acetyl
acetonate, the silylated polyaminopolyamide, and the cationic
lubricant, are solubilized by acids and/or lower alcohols,
the inclusion of minor additional amounts of alcohols such
as methanol, ethanol, propanol, isopropanol, etc. and/or
acids such as hydrochloric or ace-tic may be found desiLable.
The aqueous sizing compositions of the invention
can be prepared following generally accepted mixing practices.
These sizing compositions can be applied to the glass fibers
using any convenient method. The amount of aqueous sizing
composition applied is no-t narrowly critical, but is preferably
controlled so as to deposi-t on the glass fibers a size coat-
ing comprising the in situ dried residue of the aqueous sizing
composition of the invention in an amount from abou-t 0.5 to
abou-t 2 percent of the weight of the glass, taking into
account the dilution of the non-volatile components in the
aqueous sizing composition and the ~usual mechanical loss of
some of the aqueous composition initially applied to the
fibers before it is dried -thereon.
Preferably, the aqueous sizing composition is applied
to the glass fibers as they are produced by continuous drawing
from the melt. While the aqueous sizing composition on the
fibers may be at least partially dried beEore collection into
a package, it is entirely satisfac-tory to gather the wet
fibers into strands, preferably with about 100 to about 300
and more preferably about 200 individual fibers to each
strand, collecting these strands into packages as by winding
on a collet, which also provides the tension for drawing the
~ibers, and then heating the package in a conventional cir-
culating hot air oven to drive off volatile materials and
deposit the non-vola-tile components of the sizing compo-
sition as a size coating on the fibers which will also bindtogether the individual fibers into a tightly integrated
strand.
The integrated continuous glass fiber strands can
be roved together in weakly integrated roving, preferably of
about 30 to about 70 strands each to produce a continuous
glass fiber gun roving. While the diameter of the individual
glass fibers is not narrowly critical, diameters from about
lO~m to about 13~m are preferred.
EXAMPLE 1
Particularly advantageous chrome-free aqueous
sizing compositions for glass fiber gun roving,
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representa~ive of the present invention, were prepared accord-
ing to the following formulations:
Weight %
Component A B
As rec'd. Active As rec'd. Active
Airflex 410 (55~) 5.10 2.80 5.10 2.80
Resyn 25-1971 (54.5%) 4.45 2.43 4.45 2.43
P~-700 (59%) 1.25 0.7~ 1.25 0.7~
Tyzor AA (75%) 1.10 0.82 1.10 0.82
10 Y-9567 (80%) 0.03 0.024 0.10 0.08
Emery 67600 (65%) 0.03 0.02 0.03 0.02
A-174 0.0150.015 0.015 0.015
Isoproponol 2.00 -- 2.00 --
Acetic acid 0.0050.005 0.005 0.005
15 D~ I. Water Balance Balance
Both A and B formulations had non-volatile content of about
6.0~0.5 percent by weight and pH of about 3.8 to 4.9.
These compositions were applied to both H-fibers
(about 10.1 to about 11~4~m in diameter) and J-fibers (about
20 11.4 to about 12.7~m diameter) with a conventional applicator
as they were drawn from the melt, the wet fibers gathered into
strands of about 200 individual fibers and wound into pack-
ages on a rotating collet in groups of 4 strands. The pack-
ages were dried in a conventional circulating hot air oven
25 maintained at about 130C (265F) for about 12-14 hours, de-
pending on the size of the package. The dried size coating
thus deposited on the glass fibers constituted about 1.0
to about 1.3 percent of the weight of the glass and tightly
integrated the strar.ds. The strands from 13 packages of
each type of H-fibers and 11 packages of each type of J-
fibers were roved separately into weakly integrated gun
roving by conven-tional means.
The glass fiber gun rovings so produced were found
to exhibit exceptionally advantageous combinations of pro-
perties, particularly in view of the sizing compositionsbeing chrome-free. Thus, they were found -to chop easily
~:~r~ and cleanly, to produce advantageously low levels of fuzz
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and fly, to wet out rapidly and fully with conventional
unsaturated polyester matrix resins (the H-fiber roviny
being especially useful wi-th unfilled matrix resin systems
and the J-fiber roving with more viscous filled matrix
resin systems, both of which can be chemically thickened,
if desired). The dried strands unwound freely from the
packages during roving with little or no disintegration of
the strands, and the strands were sufficiently integrated
in the roving so that post-cure of the size coating after
roving was not required, but upon chopping and spraying at
the gun, the pieces of roving separated advantageously in-to
pieces of strand, which maintained good integrity.
The unsaturated polyester resin laminates formed
with these rovings exhibi-ted excellent tensile strength and
modulus, flexural strength and modulus both dry and after
immersion in boiling water for 24 hours, impact strength,
and other desirable characteristics.
Numerous variations and modifications of the
invention as particularly described herein will be apparent
to those skilled in the art, and such variations and
modifications are intended to be comprehended within the
scope of the invention.
INDUSTRIAL APPLICABILITY
The invention described herein is readily
applicable to the glass fiber industry.
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