Note: Descriptions are shown in the official language in which they were submitted.
wosl/0763~ PC~/~S90/064;~
-- 1 --
2072~
~ALLISTIC RESIST~NT COMPOSITE
ARMOR HAvTNG I~P~OvED MULTIPLE-~IT CAP~B~rITY
~ACKGROUND OF THE INVENTION
1. ~ield o~ the lnvention
This invention relates to ballistic resistant
composite articles. More particularly, this invention
relates to such articles having improved ballistic
protection.
2. ~ior Art
Ballistic atticles such as bulletproof vests,
helmets, structural members of helicopters and other
military equipment, vehicle panels, briefcases, raincoats,
lS parachutes, and umbrellas containing high strength fibers
are known. Fibers conventionall~ used include aramid
fibers such as poly (phenylenediamine terephthalamide),
graphite fibers, nylon fibers, ceramic fibers, glass
fibers and the like. For many applications, such as vests
or parts of vests, the fibers are used in a woven or
knitted fabric. For many of the applications, the fibers
are encapsulated or embedded in a matris material.
In ~The Application of High Modulus Fibers to
Ballistic Protection~, R.C. Lia~le et al., J. Macromol.
Sci.-Chem. A7(1), pp. 295-322, 1973, it is indicated on p.
298 that a fourth requirement is that the testile material
have a high degree of heat resistance. In an NTIS
publication, AD-A018 958 ~New Materials in Construction
for Improved Helmets~, A.L. Alesi et al., a multilayer
highly oriented polypropyiene film material (without
matris), referred to as ~XP~, was evaluated against an
aramid fiber (with a phenolic/polyvinyl butyral resin
matris). The aramid system was judged to have the most
promising combination of superior performance and a
minimum of p~oblems for combat helmet development. USP
4,403,012 and USP 4, 457,985 disclose ballistic resistant
composite articles comprised of networks of high molecular
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W09l/07633 2~ PCT/1'590/064~
weight polyethylene or polypropylene fibers, and matrices
composed of olefin polymers and copolymers, unsaturated
polyester resins, epo~y resins, and other resins curable
below the melting point of the fiber.
A.L. Lastnik, et al., "The Effect of Resin
concentration and Laminating Pressures on KEVLAR Fabric
Sonded with Modified Phenolic Resin~', Tech. Report
NATICK/TR-84/030, June8, 1984; disclose that an
interstitial resin, which encapsulates and bonds the
fibers of a fabric, reduces the ballistic resistance of
the resultant composite article.
US Patent Nos. 4,623,574 and 4,748,064 disclose a
simple composite structure e~hibits outstanding ballistic
protection as compared to simple composites utilizing
rigid matrices, the results of which are disclosed in the
patents. Particularly effective are weight polyethylene
and polypropylene such as disclosed in US Patent No.
4,413,110.
US Patent Nos. 4,737,402 and 4,613,535 disclose
comples rigid composite articles having improved impact
resistance which comprise a network of high strength
fibers such as the ultra-high molecular weight
polyethylene and polypropylene dïsclosed in US Patent No.
4,413,110 embedded in an elastomeric matri~ material and
at least one additional rigid layer on a major surface of
the fibers in the matris. It is disclosed that the
composites have improved resistance to environmental
hazards, improved impact resistance and are unespectedly
effective as ballistic resistant articles such as armor.
U.S. Patent 3,516,890 disclosed an armor plate
composite with multiple-hit capability. US Patent No.
4,836,084 discloses an armor plate composite composed of
four main components, a ceramic impact layer for blunting
the tip of a projectile, a sub-layer laminate of metal
sheets alternating with fabrics impregnated with a
viscoelastic synthetic material for absorbing the kinetic
energy of the projectile by plastic deformation and a
backing layer consisting of a pack of impregnated
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W091/0763~ PCT/~S90/064~
20727~8
--3--
fabrics. It is disclosed that the optimum combination of
the four main components gives a high degree of protection
at a limited wieght per unit of surface area.
Ballistic resistant armor made of ceramic tiles
S connected to a metal substrate e~hibit certain properties
which substantially reduces the multiple hit capability of
the armor. On impact of the projectile, substantial
amounts of vibrational energy are produced in addition to
the kinetic energy of the impact. This vibrational energy
10 can be transmitted as noise and shock, or can be
transmitted to vibration sensitive areas of the armor such
as to the ceramic impact layer resulting in a shattering
and/or loosing of tiles.
SUMMARY OF THE INVENTION
This invention relates to a multilayer complex
ballistic armor comprising:
(a) a hard impact layer comprised of one or more
ceramic bodies;
(b) a vibration isolating layer comprising a network
of high strength polymeric filaments having a tenacity of
at least about 7 grams/denier, a tensile modulus of at
least about 160 grams/denier and an energy-to-break of at
least about 8 joules/grams and
(c) a backing layer comprised of a rigid material.
Through use of the vibration isolating layer, shock
and vibration induced by impact of the projectile are
minimized. Moreover, the transmission of e~isting shock
and vibration which can damage portions of the ceramic
layer not hit by the projectile is inhibited which
substantially increases the multiple hit capability of the
armor.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more fully understood and
further advantages will become apparent when reference is
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WO 91/0~633 P~/l,S90tO64
C~ qr~
made to the following detailed description of the
invention and the accompanying drawings in which:
FIG 1 is a prospective view o an armor plate
according to this invention showing its essential elements
5 of a ceramic impact layer, a vibration isolating layer and
a backing layer;
FIG 2 is a view in cross-section and side elevation
of another embodiment of this invention showing a modified
vibration isolating layer.
FIG 3 is a view in cross-section and side elevation
of a modified embodiment of this invention depicted in FIG
2.
FIG 4 is a view in cross-section and side elevation
of an embodiment of this invention having a modified
15 ceramic layer.
~ETAILED DESCRIPTION OF THE INVENTION
The present invention will be better understood by
20 those of skill in the art by reference to the above
- figures. Referring to FIG 1, the numeral 10 indicates a
ballistic resistant article 10. Article 10, as shown in
FIG 1, comprises three maintain components; a ceramic
impac'. layer 12, a vibration isolating layer 14, and a
25 backing layer 16. In the preferred embodiments of this
invention, ceramic impact layer 12 comprises a plurality
of ceramic bodies 18, in the more preferred embodiments of
the invention, ceramic impact layer 12 comprises at least
about four ceramic bodies 12 and in the most preferred
30 embodiments of the invention, ceramic impact layer 12 -
comprises at least about nine ceramic bodies 12, with --
those embodiments in which the number of bodies 12 in
layer 12 is at least about sisteen being the embodiment of
choice.
Ceramic impact layer 12 is e~cellently suitable for
blunting the tip of the projectile, particularly because
the ceramic material forming layer 12 will retain its
hardness and strength despite the high increase in
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~O 91/0763
Pcr/~C,so/0
2~727~8
temperature that will occur in the region struck by a
projectile. Ceramic impact layer 12 comprises of one or
more of ceramic bodies 18.
~ody 18 is formed of a ceramic material. Useful
5 ceramic materials may vary widely and include those
materials normally used in the fabrication of cera~ic
armor which function to partially deform the initial
impact surface of a projectile or cause the projectile to
shatter. Illustrative of such metal and non-metal ceramic
io materials are those described in C.F. Liable, Ballistic
Materials and Penetration Mechanics, Chapters 5-7 (1980)
and include single osides such as aluminum oside
(A1203), bariu~ oside (~aO), beryllium oxide (BeO),
calcium oxide ~CaO), cerium oside (Ce203 and CeO2),
15 chromium oside (Cr203), dysprosium oxide (Dy203),
erbium oxide (Er203), europium oside: (EuO,
2 3 u204), (Eul6021), gadolinium oside
(Gd203), hafnium oside (HfO2), holmium oxide
(Ho203), lanthanum oside (La203), lutetium oxide
(Lu203), magnesium oside (MgO), neodymium oxide
(Nd203), niobium oside: (NbO, Nb203, and NbO2),
(Nb205), plutonium oside: (PuO, Pu203, and
Pu02), praseodymium oside: (PrO2, Pr6011, and
Pr203), promethium oside (Pm203), samarium oside
(SmO and Sm203), scandium oside (Sc203), silicon
dioside (SiO2), strontium oside (SrO), tantalum oside
(Ta205), terbium oside (Tb203 and Tb407),
thorium oside (ThO2), thulium oside (Tm~03),
titanium oside: (TiO, Ti2o3~ Ti305 and TiO2.),
30 uranium oside (U02, U308 and U03), vanadium oside
(VO, V203, V02 and V205), ytterbium oside
(Yb203), yttrium oside (Y203), and zirconium oxide
(ZrO2). Useful ceramic materials also include boron
carbide, zirconium carbide, beryllium carbide, aluminum
35 beride, aluminum carbide, boron carbide, silicon carbide,
aluminum carbide, titanium nitride, boron nitride,
titanium carbide, titanium diboride, iron carbide, iron
nitride, barium titanate, aluminum nitride, titanium
WO9l/07633 PCT/US90/064~5
7 ~ ?~ ~ -6-
niobate, boron carbide, silicon boride, barium titanate,
silicon nitride, calcium titanate, tantalum carbide,
graphites, tungsten; the ceramic alloys which include
cordierite/MAS, lead zirconate titanate/PLZT,
alumina-titanium carbide, alumina-zirconia,
zirconia-cordierite/ZrMAS; the fiber reinforced ceramics
and ceramic alloys; glassy ceramics; as well as other
useful materials. Preferred materials for fabrication of
ceramic body 12 are aluminum o~ide and metal and non metal
10 nitrides, borides and carbides. The most preferred
material for fabrication of ceramic body 18 is aluminum
o~ide and titanium diboride.
The structure of ceramic body 18 can vary widely
depending on the use of the article. For esample, body 18
15 can be a unitary structure composed of one ceramic
material or multilayer construction composed of layers of
the same material or different ceramic materials.
While in the figures ceramic body 18 is depicted as a
cubular solid, the shape of ceramic body 18 can vary
20 widely depending on the use of the article. For example,
ceramic body 18 can be an irregularly or a regularly
shaped body. Illustrative of a useful ceramic body 18 are
cubular, rectangular, cylindrical, and polygonal (such as
triangular, pentagonal and hesagonal) shaped bodies. In
25 the preferred embodiments of the invention, ceramic body
18 is of cubular, rectangular or cylindrical cross-section.-
The size (width and height) of body 18 can also varywidely depending on the use of article 10. For example,
in those instances where article 10 is intended for use in
the fabrication of light ballistic resistant composites
for use against light armaments, body 18 is generally
smaller; conversely where article 10 is intended for use
in the fabrication of heavy ballistic resistant composites
for use against heavy armaments then body 18 is generally
larger.
The ceramic bodies 18 are attached to vibration
isolating layer 14 which isolates or substantially
isolates vibrational and shock waves resulting from the
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u091/0763~ PCT/~.~90/064~'
_7- 20727~1~
impact of a projectile at a body 18 from other bodies 18
included in layer 12, and reduces the likelihood that
bodies 18 not at the point of projectile contact will
crack, shatter or loosen. The armor of this invention has
S relatively higher efficiency of shock absorbance. The
efficiency of shock absorbance can be measured by the
number of completely undamaged (i.e. free of cracks and
flaws) ceramic bodies 18 immediately adjacent to the body
or bodies 18 at the point of impact retained after
impact. The % efficiency of shock absorbance can be
calculated from the following equation:
% efficiency of shock absorbance ,
100% ~ [l-d/t]
where "t" is the theoretical maximum number of ceramic
bodies 18 immediately adjacent to the ceramic body or
bodies 18 at the point of contact and ~d" is the
difference between the theoretical ma~imum number of
20 ceramic bodies 18 minus the actual number of completely
undmaged ceramic bodies 18. Ceramic bodies 18 at the
point of contact may vary from one for as for e~ample for
impacts at the center of a ceramic body 18 or at the
corner of a body 18 at the edg-e of ceramic impact layer
12, to two for impacts at the seam of two adjacent ceramic
bodies 18 or at the corner of two adjacent ceramic bodies
18 at the edge of impact layer 12 to four where the impact
is at the intersecting corner of four adjacent ceramic
bodies 18. In the preferred embodiments of the invention,
30 % efficiency of shock absorbance is at least about 70%, in
the more preferred embodiments of the invention, the %
efficiency of shock absorbance is at least about 95%, and
in the most preferred embodiments of the invention, the %
efficiency of shock absorbance is about 99 to about 100%.
The amount of a surface of vibration isolating layer
14 covered by ceramic bodies 18 may vary widely. In
general, the greater the area percent of the surface
vibration isolating layer 14 covered or loaded, the more
, . . .
:
.
.
WO 91 /07633 PCr/1 ~9~)/064~'
--10--
poly(acrylamide), poly(N-isopropylacrylamide) and the
like, polyesters; polyethers; fluoroelastomers;
poly(bismaleimide); fle~ible epo~ies; ~lexible phenolics;
polyurethanes; silicone elastomers; epoxy-polyamides;
5 poly(alkylene o~ides); polysulfides; fle~ible polyamides;
unsaturated polyesters; vinyl esters, polyolefins, such as
polybutylene and polyethylene; polyvinyls such as
poly~vinyl formate), poly(vinylbenzoate), poly(vinyl-
carbazole), poly(vinylmethylketone), poly(vinyl-methyl
10 ether), polyvinyl acetate, polyvinyl butyral, and
poly(vinyl formal); and polyolefinic elastomers.
Preferred adhesives are polydienes such as
polybutadiene, polychloroprene and polyisoprene; olefinic
and copolymers such as ethylene-propylene copolymers,
15 ethylene-propylene-diene copolymers, isobutylene-isoprene
copolymers, and chlorosulfonated polyethylene; natural
rubber; polysulfides; polyurethane elastomers;
polyacrylates; polyethers; fluoroelastomer; unsaturated
polyesters; vinyl esters; alkyds; flesible epo~y; flesible
20 polyamides; epichlorohydrin; polyvinyls; flesible
phenolics; silcone elastomers; thermoplastic elastomers;
copolymers of ethylene, polyvinyl formal, polyvinyl
butyal; and poly(bis-maleimide); Blends of any
combination of one or more of the above-mentioned adhesive
25 materials. Most preferred adhesives are polybutadiene,
polyisoprene, natural rubber, ethylene-propylene
copolymers, ethylene-propylene-diene terpolymers,
polysulfides, polyurethane elastomers, chlorosulfonated
polyethylene, polychloroprene, poly(isobutylene-co-
3~ isoprene), polyacrylates, polyesters, polyethers,fluoroelastomers, unsaturated polyesters, vinyl esters,
flesible eposy, flesible nylon, silicone elastomers,
copolymers of ethylene, polyvinyl formal, polyvinyl
butryal. Blends of any combination of one or more of the
above-mentioned adhesive materials.
Vibration isolating layer 14 comprises a network of
high strength polymeric filaments having a tenacity
modulus of at least about 7 grams/denier, a tensile
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WO91/0763~ PCT/~S90/064~
20727~
--11--
modulus of at least about 160 grams/denier and an
energy-in-break of at least about 8 joules/gram. The
fibers in the vibration isolating layer 14 may be arranged
in networks having various configurations. For e~ample, a
5 plurality of filaments can be grouped together to form a
twisted or untwisted yarn bundles in various alignment.
In preferred embodiments of the invention, the filaments
are aligned substantially parallel and unidirectionally to
form a unia~ial layer in which a matri~ material
10 substantially coats the individual filaments. Two or more
of these layers can be used to form a layer 14 with
multiple layers of coated undirectional filaments in which
each layer is rotated with respect to its adjacent
layers. An e~ample is a with the second, third, fourth
and fifth layers rotated ~45, -45, 90 and 0 with respect
to the first layer, but not necessarily in that order.
Other e~amples include a layer 12 with a 0/90 layout of
yarn or filaments.
The type of filaments used in the fabrication of
layer 14 may vary widely and can be metallic filaments,
semi-metallic filaments, inorganic filaments and/or
organic filaments. Preferred filaments for use in the
practice of this invention are those having a tenacity
equal to or greater than about 10 g/d, a tensile modulus
25 egual to or greater than about 150 g/d, and an
energy-in-break equal to or greater than about 8
joules/grams. Particularly preferred filaments are those
having a tenacity equal to or greater than about 20 g/d, a
tensile modulus equal to or greater than about 500 g/d and
30 energy-to-break equal to or greater than about 30
joules/grams. Amongst these particularly preferred
embodiments, most preferred are those embodiemnts in which
the tenacity of the filaments are equal to or greater than
about 25 g/d, and energy-to-break is equal to or greater
than about 35 joules/gram. In the practice of this
invention, filaments of choice have a tenacity equal to or
greater than about 30 g/d and the energy-to-break is equal
to or greater than about 40 joules/gram.
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W091/07633 PCT/~S90/064~5
~ 3 -12-
Illustrative of useful organic filaments are those
composed of polyesters, polyolefins, polyetheramides,
fluoropolymers, polyethers, celluloses, phenolics,
polyesteramides, polyurethanes, epo~ies, amimoplastics,
5 silicones, polysulfones, polyetherketones, polyetherether-
ketones, polyesterimides, polyphenylene sulfides,
polyether acryl ketones, poly(amideimides), and
polyimides. Illustrative of other useful organic
filaments are those composed of aramids (aromatic
polyamides), such as poly(m-~ylylene adipamide),
poly(p-~ylylene sebacamide), poly 2,2,2-trimethyl-
hexamethylene terephthalamide), poly (piperazine
sebacamide), poly (metaphenylene isophthalamide) ~Nomex)
and poly (p-phenylene terephthalamide) (Kevlar); aliphatic
and cycloaliphatic polyamides, such as the copolyamide of
30% he2amethylene diammonium isophthalate and 70%
hexamethylene diammonium adipate, the copolyamide of up to
30% bis-(-amidocyclohe~yl)methylene, terephthalic acid and
caprolactam, polyhe~amethylene adipamide (nylon 66),
poly(butyrolactam) (nylon 4), poly (9-aminonoanoic acid)
(nylon 9), poly(enantholactam) (nylon 7),
poly(capryllactam) (nylon 8), polycaprolactam (nylon 6),
poly (p-phenylene terephthalamide), polyhesamethylene
sebacamide (nylon 6,10), polyaminoundecanamide (nylon 11),
25 polydodeconolactam (nyion 12), polyhe~amethylene
isophthalamide, polyhe~amethylene terephthalamide,
polycaproamide, poly(nonamethylene azelamide) (nylon 9,9),
poly(decamethylene azelamide) (nylon 10,9),
poly(decamethylene sebacamide) (nylon 10,10),
polytbis-(4-aminocyclothe~yl) methane 1,10-
decanedicarbo~amide] (Qiana) (trans), or combination
thereof; and aliphatic, cycloaliphatic and aromatic
polyesters such as poly(l,4-cyclohe~lidene dimethyl
eneterephathalate) cis and trans, poly(ethylene-l,
5-naphthalate), poly(ethylene-2,6-naphthalate), poly(l,
4-cyclohe~ane dimethylene terephthalate) ~trans),
poly(decamethylene terephthalate), poly(ethylene
terephthalate), poly(ethylene isophthalate), poly(ethylene
,
,.
W09l/07633 PCT/~S90/064~;
2~727~8
~13-
o~ybenozoate), poly(para-hydro~y benzoate),
poly(dimethylpropiolactone), poly(decamethylene adipate),
poly(ethylene succinate), poly(ethylene azelate),
poly(decamethylene sebacate), poly(~ ~ -dimethyl-
S propiolactone), and the like.
Also illustrative of useful organic filaments are
those of liquid crystalline polymers such as lyrotropic
liquid crystalline polymers which include polypeptides
such as poly ~-benzyl L-glutamate and the like; aromatic
10 polyamides such as poly(l,4-benzamide), poly(chloro-1,4-
phenylene terephthalamide), poly(l,4-phenylene
fumaramide), poly(chloro-1,4-phenylene fumaramide),
poly(4,4'-benzanilide trans, trans-muconamide),
poly(l,4-phenylene mesaconamide), poly(l,4-phenylene)
lS (trans-1,4-cyclohesylene amide), poly(chloro-1,4-
phenylene) (trans-1~4-cyclohesylene amide), poly(l,4-
phenylene 1,4-dimethyl-trans-1,4-cyclohesylene amide),
poly(l,4-phenylene 2.5-pyridine amide), poly(chloro-1,4-
phenylene 2.5-pyridine amide), poly(3,3'-dimethyl-4,4~-
20 biphenylene 2.5 pyridine amide), poly(l,4-phenylene
4,4'-stilbene amide), poly(chloro-1,4-phenylene
4,4'-stilbene amide), poly(l,4-phenylene 4,4'-azobenzene
amide), poly(4,4'-azobenzene 4,4;-azobenzene amide),
poly(l,4-phenylene 4,4'-azosybenzene amide), poly(4,4~-
25 azobenzene 4,4'-azosybenzene amide), poly(l,4-
cyclohesylene 4,4'-azobenzene amide), poly(4,4'-azobenzene
terephthal amide), poly(3.8-phenanthridinone terephthal
amide), poly(4,4'-biphenylene terephthal amide),
poly(4,4~-biphenylene 4,4'-bibenzo amide), poly(l,4-
30 phenylene 4,4'-bibenzo amide), poly(l,4-phenylene
4,4'-terephenylene amide), poly(l,4-phenylene 2,6-naphthal
amide), poly(l,5-naphthylene terephthal amide),
poly(3,3~-dimethyl-4,4-biphenylene terephthal amide),
poly(3,3'-dimethosy-4,4'-biphenylene terephthal amide),
35 poly(3,3~-dimethosy-4,4-biphenylene 4,4'-bibenzo amide)
and the like; polyosamides such as those derived from
2,2'dimethyl-4,4'diamino biphenyl and chloro-1,4-phenylene
diamine; polyhydrazides such as poly chloroterephthalic
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WOsl/u7633 PC~/~S4~/064
14-
~ydrazide, 2,5-pyridine dicarboxylic acid hydrazide)
poly(terephthalic hydrazide), poly(terephthalic-
chlorotere~hthaliC hydrazide) and the like; poly(amide-
hydrazides) such as poly(terephthaloyl 1,9 amino-
5 benzhydrazide) and those prepared from 4-amino-
benzhydrazide, oxalic dihydrazide, terephthalic
dihydrazide and para-aromatic diacid chlorides; polyesters
such as those of the compositions include poly(o~y-trans-
1~4-cyclohe~yleneo~ycarbonyl-trans-l~4-cyclohe~ylenecarbon
10 -b-o~y-l~4-phenyl-eneo~yterephthaloyl) and.poly(oxy-cis-
1,4-cyclohe~yleneo~ycarbonyl-trans-1.4-cyclohe~ylenecarbonyl
-b-oxy-1,4-phenyleneoxyterephthaloyl) in methylene
chloride-o-cresol poly[(oxy-trans-1,4-cyclohexylene-
oxycarbonyl-trans-1,4-cyclohe2ylenecarbonyl-b-o~y-(2-methyl-
1,4-phenylene)o~y-terephthaloYl)] in 1,1,2,2-tetrachloro-
ethane-o-chlorophenol-phenol (60:25:15 vol/vol~vol),
poly[o~y-trans-1,4-cyclohesyleneoxycarbonyl-trans-1,4-
cyclohe~ylenecarbonyl-b-o~y(2-methyl-1,3-phenylene)o~y-
terephthaloyl] in o-chlorophenol and the like;
20 polyazomethines such as those prepared from
4,4~-diaminobenzanilide and terephthalaldephide,
methyl-1,4-phenylenediamine and terephthalaldelyde and the
like; polyisocyanides such as poly(~-phenyl ethyl
isocyanide), poly(n-octyl isocyanide) and the like;
25 polyisocyanates such as poly(n-alkyl isocyanates) as for
esample poly(n-butyl isocyanate), poly(n-he~yl isocyanate)
and the like; lyrotropic crystalline polymers with
heterocylic units such as poly(l,4-phenylene-2,6-
benzobisthiazole)(PBT), poly(l,4-phenylene-2,6-
30 benzobiso~azole)(P80), poly(l,4-phenylene-1,3,4-
02adiazole), poly(l,4-phenylene-2,6-benzobisimidazole),
polyt2,5(6)-benzimidazole] (AB-PBI), polyt2,6-(1,4-
phneylene)-4-phenylquinoline], poly[l,l'-(4,4~-
biphenylene)-6,6'-bis(4-phenylquinoline)] and the like;
polyorganophosphazines such as polyphosphazine,
polybispheno2yphosphazine, polytbis(2,2,2'
trifluoroethyelene) phosphazine] and the like; metal
polymers such as those derived by condensation of
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WO91/07633 PCT/~S()0/064;;
20727~8
trans-bis(tri-n-butylphosphine)platinum dichloride with a
bisacetylene or trans-bis(tri-n-butylphosphine)bis(1,4-
butadinynyl)platinum and similar combinations in the
presence of cuprous iodine and an amide; cellulose and
5 cellose derivatives such as esters of cellulose as for
example triacetate cellulose, acetate cellulose,
acetate-butyrate cellulose, nitrate cellulose, and sulfate
cellulose, ethers of cellulose as for example, ethyl ether
cellulose, hydro~ymethyl ether cellulose, hydro~ypropyl
10 ether cellulose, carbo~ymethyl ether celulose, ethyl
hydroxyethyl ether cellulose, cyanoethylethyl ether
cellulose, ether-esters of cellulose as for example
aceto~yethyl ether cellulose and benzoylo~ypropyl ether
cellulose, and urethane cellulose as for example phenyl
15 urethane cellulose; thermotropic liquid crystalline
polymers such as celluloses and their derivatives as for
example hydro~ypropyl cellulose, ethyl cellulose
propiono~ypropyl cellulose; thermotropic copolyesters as
for e~ample copolymers of 6-hydro~y-2-naphthoic acid and
p-hydro~y benzoic acid, copolymers of 6-hydro~y-2-
naphthoic acid, terephthalic acid and hydroquinone and
copolymers of poly(ethylene terephthalate) and
p-hydro~ybenzoic acid; and thermotropic polyamides and
thermotropic copoly(amide-esters).
Also illustrative of useful organic filament for use
in the fabrication of vibration isolating layer 14 are
those composed of e~tended chain polymers formed by
polymerization of ,~-unsaturated monomers of the formula:
Rl R2-C ' CH2
wherein:
Rl and R2 are the same or different and are
hydrogen,hydrosy, halogen, alkylcarbonyl, carboxy,
alkosycarbonyl, heterocycle or alkyl or aryl either
unsubstituted or substituted with one or more substituents
selected from the group consisting of alkoxy, cyano,
hydrosy, alkyl and aryl. Illustrative of such polymers of
wos1Jo~63~ ~ PCT/~S90/064
-16-
L.B-unsaturated monomers are polymers including
polystyrene, polyethylene, polypropylene,
poly(l-octadence), polyisobutylene, poly(l-pentene),
poly(2-methylstyrene), poly(4-methylstyrene),
5 poly(l-hexene), poly(l-pentene), poly(4-methoxystrene),
poly(5-methyl-1-he~ene), poly(4-methylpentene), poly
(l-butene), polyvinyl chl~ride, polybutylene,
polyacrylonitrile, poly(methyl pentene-l), poly(vinyl
alcohol), poly(vinylacetate), poly(vinyl butyral),
10 poly(vinyl chloride), poly(vinylidene chloride), vinyl
chloride-vinyl acetate chloride copolymer, poly(vinylidene
fluoride), poly(methyl acrylate, poly(methyl
methacrylate), poly(methacrylo-nitrile), poly(acrylamide),
poly(vinyl fluoride), poly(vinyl formal), poly(3-methyl-
lS l-butene), poly(l-pen.tene), poly(4-methyl-1-butene),
poly(l-pentene), poly(4-methyl-1-pentence, poly(l-he~ane),
poly(5-methyl-1-he~ene), poly(l-octadence), poly(vinyl-
cyclopentane), poly(vinylcyclothe~ane), poly(a-vinyl-
naphthalene), poly(vinyl methyl ether), poly(vinyl-
20 ethylether), poly(vinyl propylether), poly(vinylcarbazole), poly(vinyl pyrolidone), poly(2-chlorostyrene),
poly(4-chlorostyrene), poly(vinyl formate), poly(vinyl
butyl ether), poly(vinyl octyl ether), poly(vinyl methyl
ketone), poly(methylisopropenyl ketone),
25 poly(4-phenylstyrene) and the like.
Illustrative of useful inorganic filaments for use-in
the fabrication of vibration isolating layer 14 are glass
fibers such as fibers formed from quartz, magnesia
aluminosilicate, non-alkaline aluminoborosilicate, soda
30 borosilicate, soda silicate, soda lime-aluminosilicate,
lead silicate, non-alkaline lead boroalumina, non-alkaline
barium boroalumina, non-alkaline zinc boroalumina,
non-alkaline iron aluminosilicate, cadmium borate, alumina
fibers which include ~saffil" fiber in eta, delta, and
theta phase form, asbestos, boron, silicone carbide,
graphite and carbon such as those derived from the
carbonization of polyethylene, polyvinylalcohol, saras,
polyamide (Nome~) type, nylon, polybenzimidazole,
... . .
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0 9 1 /07633 Pl / I~S90/064~
207274~
polyoxadiazole, polyphenylene, PPR, petroleum and coal
pitches (isotropic), mesophase pitch, cellulose and
polyacrylonitrile, ceramic fibers such as those of the
ceramic materials discussed earlier for the use in the
5 fabrication of ceramic body 18, metal fibers as for
e~ample steel, aluminum metal alloys, and the like.
In the preferred embodiments of the invention,
vibration isolating layer 14 is fabricated from a filament
network, which may include a high molecular weight
10 polyethylene filament, a high molecular weight
polypropylene filament, an aramid filament, a high
molecular weight polyvinyl alcohol filament, a high
molecular weight polyacrylonitrile filament or mixtures
thereof. Highly oriented polypropylene and polyethylene
filaments of molecular weight at least 200,000, preferably
at least one million and more preferably at least two
million may be used in the fabrication of girdle 14. Such
high molecular weight polyethylene and polypropylene may
be formed into reasonably well oriented filaments by the
techniques prescribed in the various references referred
to above, and especially by the technique of US Patent
Nos. 4,413,110, 4,457,985 and 4,663,101 and preferable US
Patent Application Serial Nos. 895,396, filed Auqust 11,
1986, and 069,~84, filed July 6, 1987. Since
25 polypropylene is a much less crystalline material than
polyethylene and contains pendant methyl groups, tenacity
values achievable with polypropylene are generally
substantially lower than the corresponding values for
polyethylene. Accordingly, a suitable tenacity is at
least about 8 grams/denier,~ith a preferred tenacity being
at least about 11 grams/denier. The tensile modulus for
polypropylene is at least about 160 grams/denier,
preferably at least about 200 grams/denier.
High molecular weight polyvinyl alcohol filaments
having high tensile modulus preferred for use in the
fabrication of layer 14 are described in USP 4,440,711 to
Y. Kwon, et al., which is hereby incorporated by reference
to the e~tent it is not inconsistent herewith. In the
. .
, ~ ,, .
WO91/07633 PCT/~S90/0~5
q~ 18-
case of polyvinyl alcohol (Pv-OH), PV-OH ilament of
molecular weight of at least about 200,000. Particularly
useful Pv-OH filament should have a modulus of a~ least
about 300 g/denier, a tenacity of at least about 7
5 g/denier (preferably at least about 10 g/denier, ~ore
preferably at about 14 g/denier, and most preferably at
least about 17 g/denier), and an energy to break o~ at
least about 8 joules/g. P(V-OH) filaments having a weight
average molecular weight of at least about 200,000, a
tenacity of at least about 10 g/denier, a modulus of at
least about 300 g/denier, and an energy to break of about
8 joules/g are more useful in producing a ballistic
resistant article. P(V-OH) filament having such
properties can be produced, for e~ample, by the process
15 disclosed in US Patent No. 4,599,267.
In the case of polyacrylonitrile (PAN), PAN filament
for use in the fabrication of layer 14 are of molecular
weight of at least about 4000,000. Particularly useful
PAN filament should have a tenacity of at least about 10
20 g/denier and an energy-to-break of at least about 8
joule/g. PAN filament having a molecular weight of at
least about 4000,000, a tenacity of at least about 15 to
about 20 g/denier and an energy-to-break of at least about
8 joule/g is most useful in producing ballistics resistant
articles; and such filaments are disclosed, for e~ample,
in US 4,535,027.
In the case of aramid filaments, suitable aramid
filaments for use in the fabrication of girdle 14 are
those formed principally from aromatic polyamide are
30 described in US Patent No. 3,671,542, which is hereby
incorporated by reference. Preferred aramid filament will
have a tenacity of at least about 20 g/d, a tensile
modulus of at least about 400 g/d and an energy-to-break
at least about 8 joules/gram, and particularly preferred
aramid filaments will have a tenacity of at least about 20
g/d, a modulus of at least about 480 g/d and an energy to -
break of at least about 20 joules/gram. Most preferred
aramid filaments will have a tenacity of at least about 20
- . ,
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.. . . .
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~O 9~/0763~ PCr/l~S90/064~
20727~
--19--
g/denier, a modulus of at least about 900 g/denier and a~
energy-to-~reak of at least about 30 joules/gram. For
example, poly(phenylenediamine terephalamide) filaments
produced commerciall~ by Dupont Corporation under the
trade name of Kevlar 29, 99, 129 and 149 and having
moderately high moduli and tenacity values are
particularly useful in forming ballistic resistant
composites. Also useful in the practice of this invention
is poly(metaphenylene isophthalamide~ filaments produced
commercially by Dupont under the trade name Nomex.
In the more preferred embodiments of this invention,
layer 19 is formed of filaments arranged in a network
which can have various configurations. For example, a
plurality of filaments can be grouped together to form a
twisted or untwisted yarn The filaments or yarn may be
formed as a feltted, knitted or woven (plain, basket,
sating and crow feet weaves, etc.) into a network, or
formed into a network by any of a variety of conventional
techniques. In the preferred embodiments of the
invention, the filaments are untwisted mono- ilament yarn
wherein the filaments are parallel, unidirectionally
aligned. For e~ample, the filaments may also be formed
into nonwoven cloth layers be convention techniques.
In the most preferred embodiments of this invention,
vibration isolating layer 14 is composed by one or more
layers of continuous fibers embedded in a continuous phase
of an elastomeric matri~ material which preferably
substantially coats each filament contained in the bundle
of filaments. The manner in which the filaments are
dispersed may vary widely. The filaments may be aligned
in a substantially parallel, unidirectional fashion, or
filaments may be aligned in a multidirectional fashion, or
with filaments at varying angles with each other. In
preferred embodiments of this invention, filaments in each
layer forming layer 12 are aligned in a substantially
parallel, unidirectional fashion such as in a prepreg,
pultruded sheet and the like.
WO91/07633 PCT/US90/064~;
20-
wetting and adhesion of filaments in the polymer or
matrices, is enhanced by prior treatment of the surface of
the filaments. The method of surface treatment may be
chemical, physical or a combination of chemical and
5 physical actions. E~amples of purely chemical treatments
are used of SO~ or chlorosulfonic acid. Examples of
combined chemical and physical treatments are corona
discharge treatment or plasma treatment using one of
several commonly available machines.
The matri~ material is a low modulus elastomeric
material. A wide variety of elastomeric materials and
formulation may be utilized in the preferred embodiments
of this invention. Representative e~amples of suitable
elastomeric materials for use in the formation of the
15 matri~ are those which have their structures, properties,
and formulation together with cross-linking procedures
summarized in the Encyclopedia of Polymer Science, Volume
5 in the section Elastomers-Synthetic (John Wiley & Sons
Inc., 1964). For example, any of the following
elastomeric materials may be employed: polybutadiane,
polyisoprene, natural rubber, ethylene-propylene
copolymers, ethylene-propylene-dien terpolymers,
polysulfide polymers, polyurethane elastomers,
chlorosulfonated polyethylene, polychloroprene,
plasticized polyvinylchloride using dioctyl phthate or
other plasticers well known in the art, butadiene
acrylonitrile elastomers, poly(isobutylene-co-isoprene),
polyacrylates, polyesters, unsaturated polyesters, vinyl
esters, polyethers, fluoroelastomers, silicone elastomers,
thermoplastic elastomers, and copolymers of ethylene.
Particularly useful elastomers are polysulfide -
polymers, polyurethane elastomers, unsaturated polyesters
vinyl esters; and block copolymers of conjugated dienes
such as butadiene and isoprene are vinyl aromatic monomers
such as styrene, vinyl toluene and t-butyl styrene are
preferred conjugated aromatic monomers. Block copolymers
incorporating polyisoprene may be hydrogenated to produce
thermoplastic elastomers having saturated hydrocarbon
,................................. . . . . ... . .
. .
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WO 91/0,633 PCI/l,'S90/064~
20727~(~
-21-
elastomer segments. The polymers may be simple tri-block
copolymers of the type A-B-A, multiblock copolymers o~ the
type (AB)n (n-2-10) or radial configuration copolymers o~
the type R-(8A)x (x-3-150); wherein A is a block from a
5 polyvinyl aromatic monomer and ~ is a block rom a
conjugated dien elastomer. Many of these polymers are
produced commercially by the Shell Chemical Co. and
described in the bulletin "Kraton Thermoplastic Rubber",
SC-68-81.
Most preferably, the elastomeric matrix material
consists essentially of at least one of the
above-mentioned elastomers. The low modulus elastomeric
matrixes may also include fillers such as carbon black,
glass microballons, and the like up to an amount
15 preferably not to exceed about 250% by volume of the
elastomeric material, more preferably not to exceed about
100% by weight and most preferably not to exceed about 50%
by volume. The matri~ material may be extended with oils,
may include fire retardants such as halogenated parafins,
and vulcanized by sulfur, peroxide, metal o~ide, or
radiation cure systems using methods well known to rubber
technologists. Blends of different elastomeric materials
may be blended with one or more thermoplastics. High
density, low density, and linear low density polyethylene
25 may be cross-linked to obtain a matri~ material of
appropriate properties, either alone or as blends. In
every instance, the modulus of the elastomeric matri~
material should not e~ceed about 6,000 psi (41,300 kpa),
preferably is less than about 5,000 psi (34,500 kpa), more
preferably is less than 500 psi (3450 kpa).
In the preferred embodiments of the invention, the
matri~ material is a low modulus, elastomeric material
has a tensile modulus, measured at about 23C, of less
than about 7,000 psi (41,300 kpa). Preferably, the
tensile modulus of the elastomeric material is less than
about 5,000 psi (34,500 kpa), more preferably, is less
than 1,000 psi (6900 kpa) and most preferably is less than
about 500 psi (3,450 kpa) to provide even more improved
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WO91/07633 PC~/~S90/064;~
-22-
performance. The glass transition temperature (tg) of the
elastomeric material (as evidenced by a sudden drop in the
ductility and elasticity of the material) is less than
about 0 C. Preferable, the Tg of the elastomeric material
5 is less than about -40 C, and more preferably is less than
about -50 C. The elastomeric material also has an
elongation to break of at least about 50% Preferably, the
elongation to break of the elastomeric material is at
least about 300%
The proportions of matrix to filament in layer 14 may
vary widely depending on a number of factors including,
whether the matrix material has any ballistic-resistant
properties of its own (which is generally not the case)
and upon the rigidity, shape, hèat resistance, wear
resistance, flammability resistance and other properties
desired for layer 14. In general, the proportion of
matrix to filament in layer 14 may vary from relatively
small amounts where the amount of matri~ is about 10% by
volume of the filaments to relatively large amount where
20 the amount of matri~ is up to about 90% by volume of the
filaments. In the preferred embodiments of this
invention, matri~ amounts of from about 15 to about 80% by
- volume are employed. All volume percents are based on the
total volume of layer 14. In the particularly preferrea
25 embodiments of the invention, ballistic-resistant articles
of the present invention, girdle 14 contains a relatively `-
minor proportion of the matri~ (e.g., about 10 to about
30% by volume of composite), since the ballistic-resistant
properties are almost entirely attributable to the
30 filaments, and in the particularly preferred embodiments
of the invention, the proportion of the matri~ in layer 14
is from about 10 to about 30% by weight of filaments.
Vibration isolating layer 14 can be fabricated using
conventional procedures. For e~ample, in those
35 embodiments of the invention in which vibration isolation
layer 14 is a woven fabric, vibration isolating layer 14
can be fabricated using conventional fabric weaving
, . . .
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.,
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WO9l/07633 ~'CT/~ISgO/064~
20727~g
-23-
techniques of the type commonly employed for ballistic
purposes such as a plain weave or a Panama weave. In
those embodiments of the invention in which vibration
isolating layer 14 is a network of fibers in a matrix,
5 vibration isolating layer 14 is formed by continuing the
combination of fibers and matrix material in the desired
co~figurations and amounts, and then subjecting the
combination to heat and pressure.
For e~tended chain polyethylene filaments, molding
temperatures range from about 20 to about 150 C,
preferably from about 80 to about 145 C, more preferably
from about 100 to about 135 C, and more preferably from
about 110 to about 130 C. The pressure may range from
about 10 psi (69 kpa to about 10,000 psi (69,000 kpa). A
15 pressure between about 10 psi (69 kpa) and about 100 psi
(690 kpa), when combined with temperatures below about 100
C for a period of time less than about 1.0 min., may be
used simply to cause adjacent filaments to stick
together. Pressures from about 100 psi to about 10,000
20 psi (69,000 kpa), when coupled with temperatures in the
range of about 100 to about 155 C for a time of between
about 1 to about 5 min., may cause the filaments to deform
and to compress together (generally in a film-like
shape). Pressures from about 100 psi (690 kpa) to about
10,000 psi (69,000 kpa), when coupled with temperatures in
the range of about 150 to about 155 C for a time of
between 1 to about 5 min., may cause the film to become
translucent or transparent. For polypropylene filaments,
the upper limitation of the temperature range would be
about 10 to about 20 C higher than for ECPE filament.
In the preferred embodiments of the invention, the
filaments (pre-molded if desired) are pre-coated with the
desired matri~ material prior to being arranged in a
network and molded into layer 14 as described above. The
coating may be applied to the filaments in a variety of
ways and any method known to those of skill in the art for
coating filaments may be used. For e~ample, one method is
to apply the matri~ material to the stretched high modulus
W091/07633 PCT/US90/064~;
7 '. ~
~ ~ 7 -24-
filaments either as a liquid, a sticky solid or particles
in suspension, or as ~luidized bed. Alternatively, the
matri~ material may be applied as a solution or emulsion
in a suitable solvent which does not adversely affect the
5 properties of the filament at the temperature of
application. In these illustrative embodiments, any
liquid may be used. However, in the preferred embodiments
of the invention in which the matrix material is an
elastomeric material, preferred groups of sol~ents include
10 water, paraffin oils, ketones, alcohols, aromatic solvents
or hydrocarbon solvents or mistures thereof, with
illustrative specific solvents including paraffin oil,
~ylene, toluene and octane. The techniques used to
dissolve or disperse the matri~ in the solvents will be
those conventionally used for the coating of similar
elastomeric materials on a variety of substrates. Other
techniques for applying the coating to the filaments may
be used, including coating of the high modulus precursor
(gel filament) before the high temperature stretching
20 operation, either before or after removal of the solvent
from the filament. The filament may then be stretched at
elevated temperatures to produce the coated filaments. -'
The gel filament may be passed through a solution of the
appropriate matris material, as for e~ample an elastomeric
25 material dissolved in paraffin oil, or an aromatic
oraliphatic solvent, under conditions to attain the
desired coating. Crystallization of the polymer in the
gel filament may or may not have taken place before the
filament passes into the cooling solution. Alternatively,
the filament may be estruded into a fluidized bed of the
appropriate matris material in powder form.
The proportion of coating on the coated filaments or
fabrics n layer 14 may vary from relatively small amounts
of (e.g. 1% by volume of filaments) to relatively large
amounts (e.g. 150% by volume of filaments), depending upon
whether the coating material has any impact or
ballistic-resistant properties of its own (which is
generally not the case) and upon the rigidity, shape, heat
..... .. . . .
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~IO9l/07633 PCT/~S90/064;~
2~727~o
-25-
resistance, wear resistance, flammability resistance and
other properties desired for the complex composite
article. In general, layer 14 containing coated filaments
should have a relatively minor proportion of coating (e.g.
5 about 10 to about 30 percent by volume of filaments),
since the ballistic-resistant properties of girdle 19 are
almost entirely attributable to the filament. Neverthe-
less, coated filaments with higher coating contents may be
employed. Generally, however, when the coating
10 constitutes greater than about 60~ (by volume of
filament), the coated filament is consolidated with
similar coated filaments to forma fiber layer without the
use of additional matrix material.
Furthermore, if the filament achieves its final
15 properties only after a stretching operation or other
manipulative process, e.g. solvent e~changing, drying or
the like, it is contemplated that the coating may be
applied to a precursor material of the final filament. IN
such cases, the desired and preferred tenacity, modulus
and other properties of the filament should be judged by
continuing the manipulative process on the filament
precursor in a manner corresponding to that employed on
the coated filament precursor. Thus, for esample, if the
coating is applied to the serogel filament described in US
25 Application Serial No. 572,607 of ~avesh et al., and the -
coated serogel filament is then stretched under defined
temperature and stretch ratio conditions, then the
filament tenacity and filament modulus values would be
measùred on uncoated serogel filament which is similarly
strétched.
It is a preferred aspect of the invention that each
filament be substantially coated with the matrix material
for the production of vibration isolating layer 14. A
filament is substantially coated by using any of the
35 coating processes described above or can be substantially -
coated by employing any other process capable of producing
a filament coated essentially to the same degree as a
filament coated by the processes described heretofore
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WO9l/07633 ~) PCT/~S90/0~
r ! ~¦ ,L '') - 2 6 -
(e.g., by employing known high pressure molding
techniques).
The filaments and networks produced therefrom are
formed into ~'simple composites~ as the precursor to
5 preparing the complex composite articles of the present
invention. The term, "simple composite~, as used herein
is intended to mean composites made up of one or more
layers, each of the layers containing filaments as
described above with a single major matrix material, which
10 material may include minor proportions of other materials
such as fillers, lubricants or the like as noted
heretofore.
The proportion of elastomeric matrix material to
filament is variable for the simple composites, with
15 matrix material amounts of from about 5% to about 150 vol
%, by volume of the filament, representing the broad
general range. Within this range, it is preferred to use
composites having a relatively high filament content, such
as composites having only about 10 to about 50 vol %
20 matri~ material, by volume of the composite, and more
preferably from about 10 to about 30 vol % matrix material
by volume of the composite.
Stated another way, the filament network occupies
different proportions of the total volume of the simple
25 composite. Preferably, however, the filament network
comprises at least about 20 volume percent of the simple
composite. For ballistic protecting, the filament network
comprises at least about 50 volume percent, more
preferably about 70 volume percent, and most preferably at
least about 95 volume percent, with the matrix occupying
the remaining volume.
A particularly effective technique for preparing a
preferred composite of this invention comprised of
substantially parallel, undirectionally aligned filaments
includes the steps of pulling a filament or bundles of
filaments through a bath containing a solution of a matrix
material preferably, an elastomeric matrix material, and
circumferentially winding this filament into a single
W O 91/07633 P(~r/US90/064~
20727~8
-27-
sheet-like layer around and along a bundle of filaments
the length of a suitable form, such as a cylinder. The
solvent is then e~aporated leaving a sheet-like layer of
filaments embedded in a matri~ that can be removed from
5 the cylindrical form. Alternatively, a plurality of
filaments or bundles of filaments can be simultaneously
pulled through the bath containing a solution or
dispersion of a matrix material and laid down in closely
positioned, substantially parallel relation to one
another on a suitable surface. Evaporation of the solvent
leaves a sheet-like layer comprised of filaments which are
coated with the matrix material and which are
substantially parallel and aligned along a common filament
direction. The sheet is suitable for subsequent
15 processing such as laminating to another sheet to form
composites containing more than one layer.
Similarly, a yarn-type simple composite can be
produced by pulling a group of filament bundles through a
dispersion or solution of the matrix material to
substantially coat each of the individual filaments, and
then evaporating the solvent to form the coated yarn. The
yarn can then, for example, be employed to form fabrics,
which in turn, can be used to form more complex composite
structures. Moreover, the coated yarn can also be
25 processed into a simple composite by employing
conventional filament winding techniques; for esample, the
simple composite can have coated yarn formed into
overlapping filament layers.
The number of layers of fibers included in layer 14
30 may vary widely. In general, the greater the number of
layers the greater the degree of ballistic protection
provided and conversely, the lesser the number of layers
the lesser the degree of ballistic protection provided.
One pre~erred configuration of layer 14 is a laminate
in which one or more layers of filaments coated with
matris material (pre-molded if desired) are arranged in a
sheet-like array and aligned parallel to one another along
a common filament direction. Successive layers of such
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Wo 91 /U~633 ~ c~ PCI /I,'S90/~)64
~,,, ij,)
,,,, -
-28-
coated unidirectional filaments can be rotated with
respect to the previous layer after which the laminate can
be ~olded under heat and pressure to form the laminate.
An example of such a layered vibration isolating layer is
5 the layered structure in which the second, third, fourth
and fifth layer are rotated 45, 45, 90 and 0 with
respect to the first layer, ~ut not necessarily in that
order. Similarly, another e~ample of such a layered layer
12 is a layered structure in which the various
10 unidirectional layers forming girdle are aligned such that
the common filament asis is adjacent layers is 0, 90.
Backing layer 16 is comprised of a rigid ballistic
material which may vary widely depending on the uses of
article 10, and may offer additional ballistic protection.
15 The term ~rigid~ as used in the present specification and
claims is intended to include semi-flesible and semi-rigid
structures that are not capable of being free standing,
without collapsing. The backing material employed may
vary widely and may be metallic, semi-metallic material,
an organic material and/or an inorganic material.
Illustrative of such materials are those described in G.S.
Brady and H.R. Clauser, ~aterials Handbook, 12th edition
(1986). Materials useful for fabrication of backing layer
16 include high modulus polymeric materials such as
25 polyamides as for esample aramids, nylon-66, nylon-6 and
the like; polyesters such as polyethylene terephthalate
polybutylene terephthalate, and the like, acetalo;
poylsulfones; polyethersulfones; polyacrylates;
acrylonitrile/butadiene/styrene copolymers; poly(amide-
imide); polycarbonates; polyphenylenesulfides;polyurethanes, polyphenyleneosides; polyester carbonates;
polyesterimides; polyimides; polyetheretherketone; epo~y
resins; phenolic resins; polysulfides; silicones;
polyacrylates; polyacrylics; polydienes; vinyl ester
resins; modified phenolic resins; unsaturated polyester;
allylic resins; alkyd resins; melamine and urea resins;
polymer alloys and blends of thermoplastics and/or
thermosets of the materials described above; and
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WO9l/07633 PCT/US90/064~
2~727~
-29-
interpenetratins polymer networks such as those of
polycyanate ester of a polyol such as the dicyanoes~er of
bisphenol-A and a thermoplastic such as a polysulfone.
These materials may be reinforced by high strength
5 filaments described above for use in the fabrication of
vibration isolating layer 14, such as aramid filaments,
Spectra polyethylene filaments, boron filaments, glass
filaments, ceramic filaments, carbon and graphite
filaments, and the like.
Useful backing materials also include metals such as
nickel, manganese, tungsten, magnesium, titanium, aluminum
and steel plate. Illustrative of useful steels are carbon
steels which include mild steels of grades AISI 1005 to
AISI 1030, medium-carbon steels of grades AISI 1030 to
15 AISI 1055, high-carbon steels of the grades AISI 1060 to
AISI 1095, free-machining steels, low-temperature carbon
steels, rail steel, and superplastic steels; high-speed
steels such as tungsten steels, molybdenum steels,
chromium steels, vanadium steels, and cobalt steels;
hot-die steels; low-alloy steels; low-expansion alloys;
mold-steel; nitriding steels for example those composed of
low-and medium-carbon steels in combination with chromium
and aluminum, or nickel, chromium, and aluminum; silicon
steel such as transformer steel and silicon-manganese
steel; ultrahigh-strength steels such as medium-carbon low
alloy steels, chrominum-molybdenum steel,
chromium-nickel-molybdenum steel, iron-chromium-
molybdenum-cobalt steeli quenched-and-tempered steels,
cold-worked high-carbon steel; and stainless steels such
as iron-chromium alloys austenitic steels, and
choromium-nickel austenitic stainless steels, and
chromium-manganese steel. Vseful materials also include
alloys such as manganese alloys, such as manganese
aluminum alloy, manganese bronze alloy; nickel alloys such
as, nickel bronze, nickel cast iron alloy, nickel-chromium
alloys, nickel-chromium steel alloys, nickel copper
alloys, nickel-molydenum iron alloys, nickel-molybdenum
steel alloys, nickel-silver alloys, nickel-steel alloys;
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iron-chromium-molYbdenUm-CObalt steel alloys; magnesium
alloys; aluminum alloys such as those of aluminum alloy
1000 series of commercially pure aluminum,
aluminum-manganese alloys of aluminum alloy 300 series,
5 aluminum-magnesium-manganese alloys, aluminum-
magnesium alloys, aluminum~copper alloys, aluminum-silicon-
magnesium alloys of 6000 series, aluminum-copper-chromium
of 7000 series, aluminum casting alloys; aluminum brass
alloys and aluminum bronze alloys. Still other materials
10 useful in the fabrication of backing layer 16 are the
fiber composites used in the fabrication of vibration
isolating layer 14 which comprises fibrous network in a
rigid matri~. Yet, other materials useful in the
fabrication o~ backing layer 16 are non-shattering glass
15 such as bulletproof glass.
FIG 2 depicts an armor plate composite 20 which
differs from the armor plate 10 of FIG 1 as far as the
construction of the vibration isolating layer 14 is
concerned, corresponding parts being referred to by like
20 numerals. In armor plate 20, vibration isolating layer 14
is composed of three superimposed constituent layers 22,
24 and 26. Layers 22 and 26 are thin layers of a metal or
non-metal rigid material such as those materials used in
the fabrication of backing layer 16 (preferably a glass-
25 filled epo~y resin), and layer 30 is a network ofpolymeric fibers in a matri~ such as those materials
discussed herein above for use in the fabrication of
vibration isolating layer l4 and is preferably e~tended
chain polyethylene fibers in a matri~. Rigid layers 26
30 and 30 function: to improve the overall performance of
vibration isolating layer 14; to improve the surface
characteristics of vibration isolation layer 14; to
provide a surface on which ceramic bodies 12 can be
attached; and to retain dimensional stability (i.e.
3S flatness and straightness) of the surface of vibration
isolating layer 14 subject to severe impact deformation.
At their contact points, constituent layers 22, 24
and 26 are bonded together with a suitable agent such as an
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adhesive described above ~or attachment of ceramic bodies
12 to vibration isolation layer 14 as for e~ample a
polysulfide or an epo~y. In composite 20, backing layer
16 is of double layer construction and includes rigid
5 layer 28 formed from a metal or rigid polymeric material
such as glass filled epoxy resin and ballistic resistant
composite and layer 30 formed from high strength fibers
such as Spectra polyethylene fibers in a polymeric matrix.
FIG 3 shows a variant of the embodiment of FIG 2,
10 which is indicated at 32. In composite 32, ceramic impact
layer 10 is covered with cover layer 34 which functions as
an anti-spall layer to retain spall or particles resulting
from the shattering of ceramic bodies 18 by the striking
projectile, and which functions to maintain ceramic bodies
15 18 which are not hit by the projectile in position. In
FIG 3, cover layer 34 consists of top cover 40 and release
layer 38. Top cover 36 is formed from a rigid material as
for e~ample the metals and non-metals described above for
use in the fabrication of backing layer 16 and is
20 preferably composed of a metal such as steel, titanium and
aluminum alloys, or of a rigid high strength polymeric
composite such as a thermoplastic resin such as a
polyurethane, polyester or polyamide, a thermosetting
resin such as epo~y, phenolic or vinylester resin or a
25 mi~ture thereof reinforced with polymeric filaments such
as aramid or e~tended chain polyethylene or inorganic
filaments such as S-glass fibers, silicon carbide fibers,
E-glass fibers, carbon fibers, boron fibers and the like.
Release layer 38 is for~ed from materials similar to those
30 used to form vibration isolating layer 14 and functions to
eliminate or to substantially reduce the strain on unhit
ceramic bodies 18 in the deformation of the composites
from impact by the projectile. The construction of
vibration isolating layer 14 and backing layer 6 in
35 composite 32 and their materials of construction are the
same as in composite 20 of FIG 2.
FIG 4 depicts composite 40, which is a variation of
the embodiment of FIG 2. Composite 40 includes ceramic
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WO 91tO7633 PCr/l,'S90/064~
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body k~taining means 42 between individual ceramic bodies
18 and peripheral impact layer retaining means 44.
Ceramic body retaining means 42 reduces the differences in
performance of segmented ceramic impact layer 12 at the
5 seams formed by adjacent ceramic bodies 18 which is
usually a weak area, and at the center of ceramic body 18
which is usually a strong area. Ceramic body retaining
means 42 also allows ma~imum loading of ceramic bodies 18
in segmented ceramic impact layer 12, provides optimized
10 spacing between adjacent ceramic bodies 18 retains unhit
ceramic bodies 18 in place upon severe impact deormation,
and transmitts and distributes the impact shock to the
entire composite 40 upon impact. Peripheral impact layer
retaining means 94 minimizes the differences in the
15 performance at the edges of the composite armor (which
because of the segmented nature of the ceramic impact
layer 14 tends to be a relatively weak area) and a: the
center of the ceramic which tends to be a relatively
strong area.
Ceramic body retaininq means 42 and peripheral impact
layer retaining means 44 are composed of an "elastic~'
material which may vary widely and be metallic, semi-
metallic material, an organic material and/or an inorganic
material. The term ~elastic~ as used in the present
25 specification and claims is intended to include materials
inherently capable of free standing without collapsing.
Illustrative of such materials are those described in G.S.
Brady and H.R. Clauser, Materials Handbook, 12th Edition
(1986). Also illustrative useful materials suitable for
30 use in the fabrication of ceramic body retaining means 42
and peripheral impact layer retaining means 44 are those
materials described herein abovefor use in the fabricaton
of the backing layer 16 and cover layer 34. These
materials include in the embodiments of FIGs. 1, 2 and 3
35 high modulus polymeric materials with or without fibrous
fillers such as a thermosetting or thermoplastic resin
such as a polycarbonate or epo~y which is optionally
reinforced by high strength filaments such as aramid
. .
WO91/07633 PCT/~S9n/O~S~
filament, Spectra~ e~tended chain polQet~ e~e filaments,
boron filament, glass filaments, ceramic filaments, carbon
and graphite filament, and the like; metals and metal
alloys such as nickel, manganese, tungsten, magnesium,
5 titanium, aluminum, steel, manganese alloys, nickel
alloys, magnesium alloys, and aluminum alloys with or
without creramic fillers such as silicone carbide; and
non-shattering glass such as bulletproof glassdescribed
above. The construction of vibration isolating layer 14
10 and backing layer 16 in composite 40 and their mateials of
construction are the same as in composite 20 of FIG 2.
Comple~ ballistic articles of this invention have
many uses. For esample, such composites may be
incorporated into more comple~ composites to provide a
lS rigid comples composite article suitable, for esample, as
structural ballistic-resistant components, such as
helmets, structural members of aircraft, and vehicle
panels.
The following esamples are presented to provide a
20 more complete understanding of the invention. The
specific techniques, conditions, materials,proportions and
reported data set forth to illustrate the principles of
the invention are esemplary and should not be construed as
limiting the scope of the invention.
EXAMPLE I
.
Eight layers of 16" (40.6 cm) s 16" (40.6 cm)
Spectra Fabric (of the style 952 plain 65~d) stitched
30 together with a Spectra 1000 polyethylene fiber were
placed between two pieces of 1/32" (0.08 cm) thin glass
reinforced eposy plastic sheet (sold by Ryerson Plastics
under the trade name GPO-2Grade PEF 2002). The sandwich
is placed in a mold. A mixture (100 grams) of a vinyl
ester resin (VE 8520 sold by Interplastics), a peroside
(Benzoate Peroside) sold by Lucidol under the tradename
Luperco AFR-400) and a promoter (N,N,-dimethyl aniline)
was poured in the mold until the sandwich surface was
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WO91/07633 PCT/US90/064~
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completely covered. The composition of the mi~ture of
vinyl ester resin/pero~ide/promoter is 10/0.1/0.006. The
material was cured for two hours at room temperature under
pressure. The thickness of the cured material was about
1/8~ (0.32 cm).
Example 2
A panel consisting of a 4 by 24 checker board with
10 square cells of dimensions of 4" (10.2cm) by 4~ (10.2cm)
by 1~2~ (1.3 cm) depth was constructed. The cells of
panel were filled with marble tiles. The panel was
constructed on a Spectra composite of Example 1. The
checker board was placed into a 16" (40.6 cm) by 16~ (90.6
15 cm) by 1/2~ (1.3 cm) aluminum frame, and was covered with
a piece of 1/8" (0.32 cm) thick polycarbonate. The whole
unit was mounted on a 1/4" (0.64 cm) thick steel plate (AR
400 sold by Ryerson Aluminum and Steel Company), and the
entire arrangement was consolidated into a single unit
20 with the thermosetting vinyl ester resin mi~ture used in
E~ample 1. After the first shot at the center of tile, 9
neighboring tiles at the point of impact remained
undamaged. Thus, the efficiency was 100~. After 5
bullets were shot at a speed of 3100 ft/sec ~944.9 m/secj .
25 at the center of the tiles, 11 tiles were retained. Among
these, 9 were undamaged and 2 were slightly cracked.
However, 9 out of 9 of these undamaged tiles were
neighboring tiles. Therefore, the efficiency remained
100% after 5 hits. Furthermore, the composite remained
flat and straight even though the steal backing plate had
buckled after 5 hits.
ComDarative E~ample 1
A panel was constructed using the same procedure
described in E~ample 2 with the e~ception that the
Spectra composite was not included. ~he panel was tested
under the same conditions. After the first shot at the
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WO91/07633 PCT/US90/0645~
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center of tile, no neighboring tiles at the point f impact
remained undamased. Thus, the efficiency is 0%. After 5
hits, all tiles had shattered. The eficiency re~ained 0%
after 5 hits.
Çom~arative ExamDle 2
A panel was constructed using the same procedure
described in E2ample 2 e~cept that a known vibration~and
10 shock isolation material - felt replaced the Spectra
composite sandwich. The felt used was a 1/8" (0.32 cm)
think 100% dense wool pad (sold by McMaster-Carr under the
trade name of 8757Kl with a weight of 1.53 lbs/sq.yd).
The sample was tested under the same conditions described
in Esample 2. After the first shot at the center of tile,
2 out of 9 meighboring tiles at the point of impact
remained undamaged. Thus, the efficiency was 22~. After
5 hits, 5 tiles were retained but they were slightly
cracked. Therefore, the efficiency was 0% after 5 hits.
20 The other tiles were all shattered. The piece of felt
used was torn into pieces after 5 shots.
ComDarative EsamDle 3
A panel was constructed using the same procedure as
Esample 2 escept that a 1/8~ (0.32 cm) thick glass
reinforced eposy composite (GRP) replaced the Spectra~
composite. This GRP is sold hy Ryerson Plastics under the
trade name Ryerte~ G-10 PHPP4008. The sample was tested
30 under the same conditions as described in Esample 2.
After the first shot at the center of tile, 1 out of 9
neighboring tiles at the point of impact remained
undamaged. Thus the efficiency was 10%. After 5 hits, 2
tiles were retained but were damaged. The remaining tiles
35 were shattered. There~ore, the efficiency was 0% after 5
hits. The GRP was badly damaged after 5 shots.
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