Note: Descriptions are shown in the official language in which they were submitted.
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; ~ I Background of the Invention ~ ~ :~
. Fiber glass has been utilized for many years in the prepara- ' :~
tion of palyester resin fiber glass reinforced articles. One of the :
more important systems utilized in preparing fiber glass reinforced
~articles is the spray-up process. In.this process a spray gan and
a flber glass roving chopper are combined so that the palyester re~in
: to be utilized and roving are sprayed simultaneously onto a mold from
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a spray gun which i~as built into it a chopper. Fiber glass utilized
~or tllese purposes is provided in the form of roving and should possess
goo-l wet-out characteristics. Thus, the application of a satisfactory
Eorming size on the surEace of the glass flber utilized to prepare
the flber glass roving for this use is important in providing a fiber
glass product whicll is compatible wlth the polyester resins utilized
in the spray-up process inclustry. Thus the sized roving must be capable
of readily mixing with the resins used in the spray gun type applicator
and should possess good laydown characteristics when sprayed on a mold
in the manner conventionally employed in the spray-up industry.
The Invention
In accordance with the present invention a novel forming
size is providéd for glass fibers which is readily compatible with
polyester resins which finds particular utility when formed into fiber
glass roving for utilization in the spray-up process fiber glass reinforce-
ment field. Thus, in accordance with the instant invention a fiber glass
sizing composition is provlded which comprises an aqueous mixture of a
polyvinyl acetate film former, a fatty acid lubricant, methacrylato chromic
chloride, and gamma (ethylene diamine) propyl trimethoxy silane. The
sizing mixture described above is provided with sufficient quantities of
ingredients to provide a formuIation which results in an aqueous mixture
containing between 7 aad 7.5 percent by weight solids. It is an important
consideration in preparing the forming size of the instant invention that
the pH of the aqueous mixture be adjusted to between 6.1 and 6.5, preferably
that it be controlled between 6.2 and 6.~
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In formlllating the novel sizing composition of the instant
invention various textile lubricants are employed and are preferably
cationic or non-ionic in character. Thus, commercially available
solubilized Eatty acid amldes including both saturated and unsaturated
Eatty acid amides wllere the acid group contains from 4 to 24 carbon
atoms are typically employed. Also utilized are anhydrous acid solu-
bilized polymers of lower molecular weight unsaturated Eatty acid amides.
A particularly effective material for utilization as a textile lubricant
in the applicant's novel system is the pelargonic acid amide of tetra-
ethylene pentamine. On a weight solids basis the sizing composition,
this lubricant is used in amounts between 4 and 7 percent.
A maJOr ingredient of the size Eormulation of the instant
invention is polyvinyl acetate film former (40 to 60 percent weight
solids) and in the typical size formulations employed in the instant
invention the polyvinyl acetate content of the aqueous size solution
ranges between 70 to 90 percent by weight basis the total weight of the
size solution solids.
A coupling-agent is employed in the preparation of the instant
size and typical of the coupling agents employed are complex compounds
of the Werner type in which a trivalent nuclear atom such as chromium
is coordinated with organic acid such as methacrylic acid, i.e., a ~ -
methacrylic acid complex of chromic chloride. Such agents are described
in U. S. Patent 2,611,718. Other Werner type couplin~ agents having
- vinyl allcyl, amino, epoxy, mercaptyl, thioalkyl, thioaryl and phenyl
groups are also suitable for incorporation of the size of the instant
invention. On the basis of the size ingredients other than water, this
material is used in amounts of 2 to 6 percent by weight solids.
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The slze composition oE the instant inventi~n also contains
gan~ma (ethylene diamine) propyl trialkoxy silanes. While it i9 contem-
plated that various alkoxy groups may be linked to the sllica atom,
the preferre(l materlal o~ thls character utilized ln the practice of
the inventlon is gamma (ethylene diamine) propyl trimethoxy silane.
Silanes of thls partlcular type have been found to be particularly
effective in producing the size composition of the instant invention
and in particular in producing fiber glass strands which when made into
roving provide a superior gun roving product for spray-up applications
in the fiber glass resin reinforcement area. On the basis of the size
ingredients other than water this material is used itl amounts of 3 to 6
percent by weight, preferably 4 to 5 percent by weight.
- In applying the formulations of the instant invention to
glass fibers the g]ass fiber strand is formed by a multitude of fine
fiber glass filaments which are drawn at a high rate of speed through
molten cones of glass located at the tips of small orifices in a bushing
such as is shown in ~. S. Patent ~o. 2,133,238. During formation the
filaments are coated while they are moving at speeds on the order of
5,000 to 20,00~ feet per minute with the forming size of the instant
invention. The size may be sprayed on the fibers as they are being -
drawn or in the preferred embodiment the fibers may be drawn across the
surface of a roller applicator on which the size is placed. The fibers
after sizing are grouped into strands which are then wound typically onto
forming packages utilizing a winder and an associated paper or plastic
or other type forming tube located on the surface of the winder in the -
conventional manner. The forming packages containing the fibe~ glass
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s~rand sized with the slzing composition of the instant invention may
then be formed into roving by unwindlng a plurality o~ strands from
several Forming packages positioned on a creel and combining the strands
Ln paral:lel ~orm and winding the strands on tubular support in the con-
ventional n~anner.
The size oE the instant invention is prepared by mixing the
polyvinyl acetate latex with water in a mixing tank with stirring. To
-the polyvinyl acetate - water mixture is added the gamma (ethylene
diamine) propyl trialkoxy silane wilich has preferably been premixed
with cold water. After mixing these ingredients the coupling agent is
added slowly to the mix tank. After mixing the coupling agent into the
mixing tank the Eiber glass lubricants are then added. The mixture is
then diluted to final volume with water. The mixture is checked for its
pH characteristics and sufficient acetic acid is added to control the
p~ between 6.1 and 6.5.
The size of the instant invention is applied to the individual
glass fibers as llas been stated during their formation. Thus, the size
is applied to the individual fibers just after they emerge from the
orifices in an electrically heated platinum alloy bushing containing the
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: molten glass. Further, the size is applied to the filaments prior to the
time they are grouped together to form a strand and application of size
! ~ iS preferably by means of a roller applicator which is partially submerged
in the size solution which is contained in the reservoir. Such an
applicator i5 shown in more detail in U. S. Patent 2,728,972. The
fibers after size is applied are then grouped into strands by using a
' graphite guide and wound around a rotating Eorming tube WtliCh produces
s strand travel of approximately 5,000 to 20,000 feet per minute. Other
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methods of applying the siæe to tlle strand of glass Eibers such as pad
applicators may he ernployed and the strand may be ~ormed by means other
tl~an winding on tlle rorming tube such as by means of a pair of rotating
wheel pullers wl~icl~ direct strand into a suitable collecting device. ~ u
AEter the fiber g:Lass strands have been wound on-the forming tube, they
are then dried at approximately 240~. Eor a period of about 11 hours.
After drying, the ~strands are then processed in a conventional manner
by placing the forming tubes on a balloon creel and combining the strands
in parallel form and winding them on a tubular support to provide roving
packages.
Upon drying subsequent to the application of the aqueous sizing
mixture, glass ~ibers are provided which contain on the surface thereof
a coating residue obtained by evaporation of the moisture on the surface
of the glass fibers of the aqueous mixture of polyvinyl acetate, fatty
acid lubricant, methacrylato chromic chloride and the gamma (ethylene -
diamine) propyl trialkoxy silane.
The following example illustrates a typical preparation of the
forming size of the instant invention.
- ~xample
Parts by Weight
(grams)
Polyvinyl acetate (film former 56 percent solids 4500
in water)
1. Volan (Werner complex of methacrylic acid- 334
chromic chloride l9 percent solids in isopropanol)
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- 2. Gamma (ethy:Lene diamine) propyl trimethoxy 226
silane in rnethanol (40 percent volume
by wt.) Z-6026
3. Cationic fatty acid amide (~mery 4046D) 24
4. Pelargonic acid amide of tetraethylene112
` pentamine (C-]85~)
Water (sufficient to provide 10 gallons of size mix)
~cetic acid - amolmt necessary to control pH at 6.3 ~ 0.2
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1. "Volan" methacrylic acid complex of chromic
cllloride sold by E. I. Du Pont.
2. ~-602fi - methanolic solution of gamma
(ethylelle diamine) trimethoxy silane sold by
Dow Corning.
3. I~`mery ~l046D - cntionic fatty acld amide sold by
Fmery Industries.
4. C-:l85A - pelargonic acld amide of tetraethylene
pentaDline sold by Imperial Chemlcal Industries.
The siæe preparation liste~ above is prepared by mixing the polyvinyl
acetate with about 35 percent of the total water to be used in preparing
the final size solution volume. The gamma (ethylene diamine) propyl
trimethoxy silane is then mixed with a small quantity of cold water and
added to the mixing tcmk Çollowed by tlle addition of the anti-static
agent. The cationic fatty acid am:ide and the pelargonic acid amide of
tetraethylene pentamine are mixed in hot water and added to the size
ingredients wlth continuous mixing. The mixing tank is then diluted
to the final volume of lO gallons. The pll is then measured and acetic
acid is added in sufficient quantity to control the pH at 6.3 + 0.2.
It is preferred that the p~l of the final size be maintained at 6.3.
After mixing the forming size of Rxample I it is applied to
the individual glass fibers during their formation. The size is applied to
the individual fibers after they emerge from the orifices in the electrically
heated platinum alloy bushing containing the molten glass and the size is
applied to the filaments prior to the timc they are grouped together
to form a strand by means of a roller applicator such as the type shown
in U. S. Patent No. 2,728,972. The fibers are collected on a collet
operating at speeds of about 6,000 revolutions. per minute and the roller
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applicator speed is maintained at approximately 145 revolutions per
minute. The Eorming packages are baked for a period of 11 hours at
240F. and are then placed on an appropriate balloon creel and wound
on a roving winder to provide a fiber glass roving product containing
the dried residlle oE the aqueous si~e composition placed on the fibers
during formation. The dried residue on the glass Eibers represents a
coating of between 1.25 and 1.55 percent by weight basis the bare glass.
Roving produced by fibers si~ed with this quantity of the si~ing of the
instant invention has been found particularly effective in producing
sp~ray-up fiber glass reinforced resin products. ~ -
While the invention has been described with reference to certain
specific examples and illustrative embodiments, it is not intended to be
limited thereby ex~ept iDsofar as appesrs ;D .he sccompsnying cltim~.
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