Note: Descriptions are shown in the official language in which they were submitted.
?~ Wo s1too490 ~ PCr/US90/0335
BALLI ST I C-R ~CQ~RTI CLE
BACE~G~
- FIELD OF THE INVENTION
This invention relates to balli~tic resistant
composite articles. More particularly, this invention
relate~ to ~uch articles having improved ballistic
protection.
PRIO~ ART
Ballis~ic articles ~uch as bullet prooE vests, :
helmets, s~ructural members of helicopter~ and other
military equipment, vehicle panels, briefcases, rain- `;
coats and umbrellas containing high ~trength eibees are
known. Plber~ conven~ionally used include aramid fibers
~uch as polytphenylanediamine t~rephthalamide), g~aphike
eiber~, nylon ~lbee~, ceramic f1bec~, glas~ eiber9 and ~he
llke. For m~ny applica~lon~ such a~ va~s oe pa~k~ o~ :
ve~, the Ciber~ are u~ed ln a woven or knlttad ~a~ric.
~0 ~or many oe the o~her appllcdklsn~, ~ha flber3 are
encapsulated or embedded ln a composite material.
In ~Tha Appllcatlon o~ High Modulus Fibers to
Balll~tic Pro~ec~iona R.C. Laible et al., J. Macromol.
Sci.-Chem. A7(1), pp. 295-322 (1973), it i-~ lndicated on
p 298 that a fourth re~uirement is that the textile
material have a high degree of heat resistance~ ~or
example, a polyamide material with a melting point of ~
255 C appears to poQ~e~s better impact properties ~`--
balli3tically than doe~ a polyolefin fiber with eguivalent
ten~ile propertie~ but a lower melting point. In an NTIS
publication, AD-A018 958 ~New ~aterial~ in Construction ~ ;
for Improved ~elmets~, A. L. Alesi et al., a m~ltilayer
highly oriented polypropylene ~ilm material ~without l~;
matrix), referred to as ~XP~, was evaluated against an ~;`
aramld ~iber ~with a p~enollc/polyvinyl bu~ycal resln
matrix). ~he aramid ~y~tem wa~ ~udged to have ~he most
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Wo91~00490 ~3 ~7~ PCT/U~g~/03358~
--2--
promising combination of superior performance and a
minimum of problems for combat helmet development. U.S.
Patent Nos. 4,457,985, and 4,403,012 disclose
ballistic-resistant composite articles comprised of
networks of high molecular weight polyethylene or
polypropylene fibers, and matrices compoqed of olefin
polymers and copolymers, unsaturated polyester resin~,
epoxy ceqins, and other resinq curabl`e below the melting
point o~ khe ~iber.
A.L. La-qtnik, et al.7 ~The E~Eect of Riqing
concentration and Laminating Pres-qures on KEVLAR Fabric
3Onded with Modified Phenolic Rasin~, Technical Report
NATICK/TR-84/030, June 8, }984: disclose that an
interstitLal re~in, whlch encap~ulate~ and bonds the
~ibers o~ a ~abrlc, eeduces khe ballistic cesiskance oE
the re~ulka~t compoaite artiale.
U.S. Pa~ent No~.4,623,57~ and 4,74~,064 dlsclos~ a
simple compo~ite ~truc~urq aomprl~ng high stc~ngth ~ibers
embedded in an elastomeeic ma~rix~ The ~imple compo~qite
8tructure exhibit~ outstanding balli~tic prote~tion as
compared to simple compo~ite~ utillzing rigid matriceq,
the re~ult~ Oe which are disclosed in the patentq.
Particularly efective are ~imple composites employing
ultra-high molecular weight poly ethylene and poly
propylene such as di-~closed in U.S. Patent No. 4,413,110.
U.S. Patent No. 4,737,402 and 4,613,535 di~clo~e
complex rigid compo-~ite articles having improved impact
resiqtance which comprise~ a network of high strength
fibers ~uch as the ultra-high molecular weight
polyethylene and polypropylene disclosed in U.S. Patent
No. 4,413,110 embedded in an elastomeric matrix material
and at one additional rigid layer on a major sur~ace of
the eibee~ in the matrix. It i~ disclo~ed that these
composites have improved ce~l~tance to environtnental
hazaed~, improved imp~ct re~ anae and are unexpec~edl~
eE~ec~ive as ballistic ee~ ant articleq such a_ armor or
helmets.
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20~927~
, ~WO 91/0049û PCr/US90/03358
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SUMMARY OF TEE INVENTION
The present invention is directed to a complex
ballis~ic resistant composite articl~ of manu~acture
having impr~ved impact resistance, said article comprised
of two or mo~e layers, at least one of said layers is a
fibcouq layer comprising a network of high strength
filaments having a tenacity of at least about 7
grams/denier, a tenqile modulus of at lea3t abaut 160
gram~/denier and an energy-to b~eak o~ at least about 8
~oules/gram in a mateix material and at least one o said
layer~ is a hard, rigid layer comptising at least one hard
cigid material which iq harder than said fibrous layer,
wherein the relative weight percent~ of said layers and
the relative positlonlng Oe ~aid layers are ~uch that said
composite exhibLts a ma~s e~iciency (Em) equal ko oc
greater than about 2~5. As used h~ceLn the ~ma~
e~1clency~ o~ a compo~ike i~ determined ~rom the
~ollowing equation:
~D~ Oe armor grade steel required to :`
~m~ de~eat a threat
~Dd 'o~~~'the'~ma~arial'u~nd~e~r con's~i~eration
raquired to de~eat a threa~
wherein:
AD is the areal den~ity of the armor or material in ~.
or lb~
m -FF2
The ma~s efficiency i~ determined by determining the AD -~
required to defeat a thraat of a designated pro~ectile at
a designated impact velocity with (1) armor grade qteel
and (2) the material under consideeation, and computing Em
by the above e~uation. Surpri~ingly, i~ has been
di~covered that the eelativa amounts o~ layers composed oE
3s higb ~eength ~ibec~ in ma~rix and o~ hard rlgid
material~, and the spacing between the layers and the
relative ordae in which these layerq are as3embled in the
complex compos~te have an e~ect on the mass efPlciency o~
:... , .,. ' ; . ' . , ` ' ', , ` ' ' " ' . . ` ':' ~
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wogl/~90 2 0 ~ 9 2 7 1 PCT/U~9~/03358
the compo~ite and ~he degree of ballistic protection
provided.
Compaeed to conven~ional ballistic-resistant armor
structures, the composite article of the present invention
can advantageously provide a selected level of ballistic
protection while employing a ~educed weight of protective
matecial. Altecnatively, the artlcle of the pre-~ent
invention can provide increased balli~tic protection aq
compared to conventlonally constructed composite armor of
equal or sub~tantially equal welght.
_ IEF DESCRIPTION OF T~E DRAWINGS
The invention will be more fully understood and
further advantages will become apparent when re~erence i9
15 made to the following detailed descrlptlon o~ the
invenkion and the accompanylng drawing~ in which:
Flgure~ 1 to 8 ~rq depic~ion~ o~ cro~ ec~lonal
views o~ v~riou~ embodimenk~ o~ thi~ inventlon ~howing
~aciou~ representatlve ~kruakural con~igura~lons.
DE~AI~BD DESCRIPTION OF THE INVEN~ION
Compo3ites Oe thL~ inv~ntion include at l~ast two
essential components. One component i~ a fibrou~ layer
comprised of a fiber network in a matrix material and ~he
other component iQ a hard rigid layer composed of one or
more hard rigid ma~erial~. The particular ~tructure of
the compo3ite may vary widely. For example, the two
layer~ may abu~ or may be separated by a void space. The ~` -
compssite may be in tbe form o~ a multiple compo~ite whioh
include~ two or more fibrou~ layer~ and two or more hard
layer3,0r may include more that one fibrou3 layer and only
one hard, rlgid layer or, alternatively may include more
than one hard rigid layer and only one ~ibrous layer,
ei~her abu~ting or sepacated by void ~pace~. Variou~
illu~tra~ive con~lgurations o~ ~his inven~ion are sqt
~orth in the ~igurQs.
Figure 1 shows one embodiment having three layers, a
hard ceramic layer 1, a hard mq~al layer ~ and a ~lbrou~
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~wosl/004so 2 0 ~ 9 ~ 7 1 P~T/US90/03358
_5_
composite layer 3. In thiS embodiment, ceramic layer 1
which is the layer first exposed to the threat function~
to 3hatter or distorted the pro~ctile. Ceramic layer 1
abuts metal layer 2 and the abutting layers 1 and 2 are
separated ~rom fibrous layer 3 by void space 4.
In Figure 2 is depicted an embodiment o~ this
invention which con~ists of hard ceramic layee 1 having a
metal or Elbrous backing layer 5 which i~ separated from
fibrou~ layer 3 by void spdce 4. In the embodiment of
Flgure 2, the hard ceramic layer 1 i~ the first layer
exposed to the threat and Eunctions to shattee or distort
the projectile thereby increasing the effectivenes~ of
Eibrous layer 3.
Figure 3 depicts a eepresentative embodiment o~ th~
invention in which metal la~er ~ is khe layer eir~t
exposed to ~he threat. Layer 2 18 3eparated erOm ceramic
layer 1 which abut~ ~ib~ou~ layec 3 by vold ~pAce 4.
Pigut~ 4 d~pict~ a mult~layor/multiveid ~p~oe
embodiment o~ th1s lnv~n~ion. Tha ~mbodim~nk o~ Figure 4
ha~ a metal layer 2 initialLy exposed to the threat,
separated Pcom cera~ic layer 1 which abuts backing layer 5
by vold spaca 4~ The abutting ceramic layer 1 and backing
layer 5 are separated ~rom ~ibrous layer 3 by vold space
4'.
In Figure 5 is depicted an e~bodiment of the
invention having multiple metal layer compos~d of layers 2
and 2' which are directly exposed the the thereat. Layers
2 and 2' are fabricated of metals having differing
hard~e~s and are separated from fibrou~ layer 3 by ~oid
space 4.
Figure 6 depicts an embodiment which is composed of
only two layers. One layer is a ceramic layer 1 which i~
dire~tly exposed to the threat and which abuts fibrou~
layer 3.
Figur~ 7 dqpicts ~n embodiment o~ ~he inven~lon
havlng a ~eramic layer 1 with a~uk~ng backing layer S
which is directly exposed to ~he thcea~. Layer l is
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w~ g~/0049~ 2 0 5 ~ 2 7 1 PCT/US90/03358 ~
--6--
separated from metal layer 2 by void space 4 which, in
turn, is separated from fibrous layer 3 by void spac~ 4'.
Figure 8 depicts an e~bodiment of the in~ention
having three abutting layers. Ceramic layer 1, which is
directly exposed to the threat abuts metal layae 2 which,
in turn, abuts fibrous laye~ 3.
In the preferred embodiments of the invention, the
compo~ite comprise~ at least two hard rigid layers oE
varying hardness in addition to the essential ~ibrous
layec. In these preferred embodiments, ~he variouQ layers
are preferably arranged in order Oe decreasing hardnes-
~with respect to the balli~tic threat, such as ceramic
layer exposed to the threat followed by a metal layer and
a fibrous layer.
In the paetlcularly pre~erred embodiments o~ thi~
lnvention, there i9 a void ~pace between one or more o~
the layer~ Oe rigid mat~rials, and the one or more layers
which lncludo th~ ~lbrous layer. The 9ize and shape Oe
the ~paae may var~ widaly dapendlng on variou~ ~actors
guch a~ limit~tion ko armor khLcknes~, limitakionq in the
con~truction o~ the ~rmor, the pe~ceived threa~ and the
like, In general, the larger the space the better
disper3ion ~divergance) and rotation of broken pieces of
the balllstic threat, and hence thQ moce e~fective the
compoqite in de~eating the threat. Conversely, the
smaller the ~pace the less the disper3ion and relation of
broken pieces of the ballistic theeat, and, hence, the
le~s effective the compo~ite in defeating the threat.
Spac~ width usually will vary ~rom about 0.5 cm to about
30 c~, preferably from about 1 cm to about 20 cm, more
preferably from about 1.5 cm to about 10 cm and most
preferably from about 2.5 cm to about 7.5 cm.
~he relative weight percent~ of fibrou~ layer(~) and `
rigid hard layer(s) in the compo~ite may vary widely. In
general, the amoun~ Oe e~ther ~ibrous layer~ 9) or hard
rigid laye~3) may var~ ~rom abou~ ~0~ to aboul: ûO~ by
weigh~ o~ the compo~ite. In the pre~errQd embodlments o~
the invention, khe amount o~ ~ibrous layer~ s) may vary
.
~ wo ~ go 2 0 ~ 9 2 7 1 PCT/US9~/~33s8
from about 20 to about 80% by weight of the composite, and
the amount of hard rigid layer~s) may vary from about 80
to about 20~ by weight of the compo~ite and in the
particularly preferred embodiments oE the invention the
amount o~ fibrous lay~r(s) may vary from about 20 to about
60~ by weight of the composite and the amount of hard
rigid layer(s) is from about 60 to about 40 ba~,ed on the
weight o~ the composite. Amongst these paeticula~ly
preferred ~mbodiments, mo~t pre~rred are those
embodimenks in whlch the amount Oe ibrou~ layee is from
about 25 to about 50~ by weight o~ the composite, and the
amount of the hard rigid layer(s) is from about 75 to
about 50~ be weight of the composite.
The structure of ~ibrou~ layer(s) may vary widely.
In the composite articles o~ our invention, the Eilament~
Ln eibrou3 layer~) may be acranged in networks havlng
various con~igueaklon~. Po~ example, a plurali~y o~
~Llaments can be grouped t~qe~hec to eo~m a tw~ted o~
untwi~ted yarn bundl~ in VA~ioU~ alignmen~. ~n pre~e~ed
~mbodiment~ Oe kha Lnvan~ion, ~he ~ila,m~nt~ in ea~h layer
are aligned ~ub~tantially parallel and unidieectionally in
which the matrix material sub~tantially coats the
individudl filamenks o~ the ~ilament~. The ~llament~ or
yarn may be ~ormed a~ a ~elt, knitted or woven ~plain,
ba9ket, satin and cro feet weaves, et-q.) into a network,
fabrica~ed into non-woven fabric, arranged in parallel
array, layered, or foemed into a fabric by any of a
variety of conventional technique~. Among the-~e
technique3, for balli~tic re~i~tance applica~ion~ we
prefer ~o u~e tho~e variationC~ commonly employed in the
preparation o~ aramia fabrics for ballistic-re3i~tant
articles. For example, the technique~, described in U.S.
Patent No. 4,181,768 and in M.R. Silyqui~t et al., J
~ , A7(1), pp. 203 ek. ~eq. (1973) are
particularly ~ui~able.
~ he typa of ~ildmen~s u~ed in the ~abricaklon o~ the
~lbrous lay~r(sO o~ the ar~icle of this invention may vary
widely and can be metallic ~ilaments, semi-metallic
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Wo91/0~90 2 0 ~ 9 2 7 ~ PCT/US90/03358 ~
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filaments, inorganic ~ilaments and/or organic filaments.
Preferred filaments for use in the practice of this
invention are tho-~e having a tenacity equal to or greater
than about lO g/d, a tensile modulus equal to or greater
than about 150 g/d and an energy-in-break equal to or
greater than about 8 joules/gram~s. Particularly preferred
filaments are those having a tenacity equal to or greater
than about 2Q g/d, a tensile modulus e~ual to or greater
than about 500 g/d and energy-~o-break equal to or geeater
than abouk 30 ~oule~/grams. Amongst thes~ particularly
preferred embodiments, most preferred are thoisie
embodimenta in which the tenacity of the filaments are
equal to or greate~ than about 25 g/d, the tensile modulus
i~ equal to or greater ~han about lOOO g/d, and the
energy-to-break ls equal to or grea~er than about 35
~oules/grams In the practice o~ th1s invention,
ilamenta Oe choice have a tenaclty e~ual t~ o~ greate~
~han abou~ 30 g/d, ~he ten~ile moduluis is equ~l to os
greate~ than ~bouk l300 g/d ~nd kh~ eneegy-to-b~e~k i~
equal to oc great~r ~han about 40 ~oulei~/gisam~
Filaments ~or use in ~ibrou~ layer~s) may be
metallic, ~emi-metallic, inorganic and/or organic.
Illu~trative of use~ul inorganic filaments are those
formal from S-glassi, ~ilicon carbide, asbe~tos, basalt,
E-glass, alumina, alumina-silicate, quartz,
zirconia-i~ilica, ceramic filament~, boron filaments,
carbon filamentsi, and the like. Exemplary of useful
metallic or semi-metallic filament3 are tho~ie composed of
boron~ aluminum, 3teel and titanium. Illustrative of
usieful organic filamentq are ~ho3a compo~ed of aramids
(aromatic polyamidesO, poly~m-xylylene adipamide),
poly(p-xylylene sebacamide), poly(2,2,2-
trimethylhexamethylene terephthalamide), poly~piperazine
sebacamide), poly~metaphenylene i-qoph~halamide) ~Nomex)
3S and poly~p-pbenylene ter~ph~halamid~) tRevlar) and
aliphakia and aycloaliphatic polyamido~, ~uch ai~ the
copolyami~e of 30~ hexametbylene diammonium isophthalate
and 70~ hexamethylene diammonium adipate, the copolyamide
. .
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~wo g~00490 2 0 ~ ~ 2 7 1 PCT~U~0/033S8
_g_
of up to 30~ bi3-(-amidoclyclohexyl) methylene, ~:
terephthalic acid and caprolactam, polyhexamethylene
adipamide (nylon 66), poly(butyrolactam) (nylon 4),
poly(9-aminonoanoic acid) (nylon 9), poly(enantholacta~)
(nylon 7), poly(capryllactam) (nylon 8), polycap~olac~am
(nylon 6), poly(p-phenylene terephthalamide),
polyhexame~hylene sebacamide ~nylon 6,10),
polyam1noundeGanamide ~nylon 11), polydodecanolactam
~nylon 12), polyhexamethylene isophthalamide,
10 polyhexamethylene terephthalam~de, polycaproamide, !
poly~nonamethylene azelamide) (nylon 9,9), ~ `-
poly(decamethylene azelamlde) (nylon 10,9),
poly~decamethylene aebacamide) (nylon 10,10), poly~bis-
~4-aminocyclohexyl)methane l,10-decanedicarbox2mLde]
~Qiana)~ran3), o~ combinakion thereo~ and aliphatic,
cycloallphaklc and aeoma~ic polye~tar3 ~uch a~ poly~l,4~
cycloh~xylld~ne dim~khyl enater~phathala~) cl~ and tran~,
poly~ethylen~-1,5~naphth~1Ate)~ poly~e~hylene~a,6-
naph~halate), poly~l,4-cycloh~xane dime~hylene
tecephthala~e) ~krans), poly~decamethylene terephthal~te),
poly~ethylene tecephthalate), poly~ethylene isophthalate),
poly~e~hylene oxybenzoate), poly~paea-hydroxy benzoate),
poly~a,~ diamethylpropiolactone), poly~decamethylene
adipate), poly~ethylene succinate) and ~he like.
Also illustrative of u~eful organic ~ilaments are
those composi~d of extended chain polymers ~ormed by
polymerization of , ~-unsaturated monomers of the foemula~
Rl R2-C - C}I2
wherein:
Rl and R2 aee the ~ame or di~erent and are
hydro~en, hydeoxy, halogen, alkylcarbonyl, ¢aeboxy,
alkoxycarbonyl, hetero¢ycle or ~lkyl or arly ~ithar
unsub~tituted ~e 9ub~kikut~d with one or more substituen~
selectQd ~rom the group con~sting of alkoxy, cyano,
hydroxy, alkyl and aryl. Illustr~kive o~ such polymers
o~ unsaturated monom~s ar~ polymers includlng
W091/00490 2 0 5 ~ 2 7 l PC~/US90/03358~i
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polyq~y~ene, polyethylene, polypropylene, poly~l-
octadecene), polyisobutylene, poly~l-pentene), poly(2-
methylstyrene), poly(4-methylstyrene), poIytl-hexene3,
poly(l-pentene), poly(4- methoxystyrene), poly(5-
methyl-l-hexene), poly(4-methylpentene), poly~l-butene),
poly(3-methyl-1-butene), poly(3-phenyl-1-propene),
polyvinyl chloride, polybutylene, polyacrylonitrile,
poly(me~hyl pentene-l), poly~vinyl alcohol),
poly~vinylace~ate), poly~inyl butyral), poly~vinyl
chloride), poly~vinylidene chloride), vinyl chlocide-vinyl
acetate chloride copolymer, poly~vinylidene fluoride),
poly~methyl acryla~e, poly(methyl methacrylate),
poly(methacrylonitrile), poly(acrylamide), poly~vinyl
1uoride), poly~vinyl focmal), poly~3-methyl-1-buk~ne),
poly~l~pentene), poly~4-methyl-1-butene), polytl-pentene),
poly~4-methyl-l~pent~ne), poly~l-he~ane), poly~5-
methyl-l-hexene), poly~l-oatadecene), poly~vlnyl
cyclopant~ne), poly~vinylcyclohexane), poly~a~
~inylnaphthalene), poly~vlnyl me~hyl ether),
poly~vinylethylether), poly~vinyl propylether), poly~vinyl
carbazole), poly~inyl pyrrolidone), poly~2-chlorostyrene),
poly~4-chlorostyrene), poly~vinyl formate), poly~vinyl
butyl eth~r), poly~vinyl octyl ether), poly(vinyl methyl
ketone), poly~methylisopropenyl ketone), poly~4-
phenyl9tyrene) and the like.
In the most preferred embodiments of the invention,all or a portlon of the fibrous layer~s~ include a
filament network, which may include a high mol~cular
wei~ht polyethylene filament, a high molecular weight
polypropylene filament, an aramid filament, a bigh
molecular weight polyvinyl alcohol filament, a high
molecular weight polyacrylonitrile filament or mixture~ . .
thereof USP 4,457,985 generally di~cusses sucb high
molecular weight polyethylene and polypropylene ~ilament~
35 and khe di~¢lo-~ure o~ thi~ patent i3 hereby in~orporatqd
by re~eren~q ~ khe ~x~ent that ~t i8 not incon~i~tent
herewith IA the case o~ polye~hylene, ~uitable filament~
are those of molecular weight o~ at l~a~t lS0,00,
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t~.~W091/0~ ~ 2 0 5 ~ 2 7 1 PCT/US90/033s8
preÇerably at least one million and more preferably
between two million and Eive million. Such extended chain
polyethylene (ECPE) f~la~ent~ may be grown in solution as
d~scribed in U.S. Patent No. 4,137,394 to Meihuzen et al.,
or U.s. Paten~ No. 4,356,138 of ~ave~h et al., issued
Oc~ober 26, 1982, or a ~ilament ~pun from a solution to
form a gel structure, aa de~cribed in Geeman Of.
3,004,699 and GB 2051667, and especlally as described in
Applicatlon Seeial No. 512,607 o~ Kavesh et al. filed
Janu~ry 20, 1984 ts~e EPA 64,167, publi~hed Nov. l0,
1982). As used herein, the term polythylene ~hall mean a
predominantly linear polyethylene material that may
contain minor amount~ o~ chain branching or monomers not
exceedlng 5 modi~ying uni~s per 100 ~ain chain carbon
atoms, and ~hat may also ~ontain admixed therewith not
more than about 50 wt~ of on~ or more polymeric additl~e~
such as alkene~l-polym~s, in paet1cular low dQn~ity
polye~hyl~n~, polypropyl~ne o~ polybu~ylene, copolymers
containing mono-ole~in~ a~ primary monomers, oxidized
polyole~ins, graft polyole~in copolymers and
polyoxymethylene~, or low molecular weight additives ~uch
as anti-oxidanta, lubeicant~, ultra-viole~ ~creening
agent3, colorants and the like which are commonly
incorpoeated by reference. Depending upon the formation
tecbnique, the draw ratio and temperature3, and other
conditions, a variety of propertie~ can be imparted to ^
these filaments. The tenacity of the filamen~-~ should be
at lea~t 15 gram~denier, preferably at lea3t 20
gram3/d~nier, more preferably at least 25 grams~denier and
mo~t preferably a~ lea~t 30 qram~/deniec. Si~ilarly, the
tenqile modulus of the filament~, a~ measured by an
In~tron tensile testing machtne~ i~ a~ least 3a0
gra~s~deniec, pre~erably at lea3t 500 grams/denier and
more prqEerably at least l,000 gram~/denier and mo~e
pre~rably a~ laa~t l,200 gram~/danier. The~e highest
values ~or tensile modulus and ~enacity are generally
obtainable only by employing solution grown oc gel
~ilaman~ processes
.
wo 91/0~90 2 0 ~ 9 2 7 1 PCT/US90/03358 ~ ~-
-12-
Similarly, highly oriented polypropylene filame~ts of
molecular weight at least 200,000, prefecably at least one
million and more preferably at least two million may be
used. SUCh high molecular weight polypropylene may be
5 formed into reasonably we}l oriented filaments by the
techniques prescribed in the various references referred
to above, and especially by the technique of U.S. Se~ial
No. $7Z,607, Eiled January 20, 1984, of Kavesh et al. and
commonly a~igned. Since 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
corre~ponding value~ ~oc polyethylene. Accoedingly, a
suitable t~nacity ls at lea~t 8 gram~/denier, wlth a
pre~errad tenacity being at least 11 gram-~denier. ~he
tensile modulus ~or polypropylene i~ at le~t 160
gcams/deni~r, pc~eerably at l~a~ ~00 g~am~ enle~.
High molacular weLghk polyvinyl alcohol ~llament~
having hi~h tens~le modulu~ ~e de~c~ibed in USP 4,440,711
to Y. Kwon, et al., which i9 h~reby incorpora~ed by
reerence to the extent it i~ not incon~istent herewith.
In the ca~ Oe polyvinyl alcohol (PV-O~), PV~O~ eilament
o~ molecular weight of at lea~t about 200,000.
Particularly useful PV-OH filamen~ ~hould have a modulus
of at least about 300 g/denier, a tenacity of at least
about 7 g/denier (pre~erably at leas~ about 10 g/denier,
more preferiaibly a~ about 14 g/denier, and mos~ preferably
at lea ~ abou~ 17 g/denier), and an energy to break of at `
lea-qt about 8 joules/g. PV-O~i filaments having a weight `~
average molecular weight of at lea~t about 200,000, a
tenacity of at lea~t 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 u~eul ln producing a ballistic
cesis~nt a~tlcle. PV-~H ilamen~ having 9Uch pcoper~ie9
cain be p~o~uced, ~o~ example~ by the procei3s disclosed in
U.S. Patent N~. 4,599~267.
In the case Oe polyacrylonitrile tPAN), PAN ~ilament
o~ molecular welght o~ at lea~t a~out 400,000.
~wo gl/o~go 2 ~ ~ 9 2 7 1 PCT/US9~/03358
-13-
Particularly useful PAN filament should have a tenacit~ of
at least ~bout 10 g/denier and an energy to break of at
least about 8 joule/g. PAN filament having a molecular
~eight of at least about 400,000, a tenacity of at least
about 15 to about 20 g/denier and an energy ta break of at
least about 8 joule/g is most u~eful in producing
ballistic resistant artic}es; and such filaments are
disclosed, for example, in USP No. 4,535,027.
In the case o aramld filament~, ~uitable aramide
~llament~ ormed principally erOm aeomatlc polyamide are
de~cribed ln US~ Patent No. 3,671,54~, which i~ hereby
incorporated by reference. Pre~erred aramid filament will
have a tenacity of at least about g/d, a tensile modulus
of at least about 400 g/d and an energy-to-break at least
about 8 joules/gram, and particulacly pre~ereed ara~id
ilamen~ will have a tenaclty o~ at lea~t about 20 g/d, a
modulus o~ at lea~t about 4ao g/d and an energy-to-bcaak
Oe at leas~ ab~ut 20 ~oule~/gram. Mo~t pre~rred aramid
eilaman~ will have a kenacity o~ a~ lo~t abou~ 20
g/d~niec, a modulu~ o~ at lea~ ~bout 900 g/denl~r and an
energy-to-brsak o~ ~t lea~t abou~ 30 ~oule~gram. ~or
example, poly~phenylenediamine terephalamide) Eilament~
produced commercislly by Dupont Corporation under the
~rade man~ o~ Kevlar~ 29 and 49 and having moderately
high moduli and tenacity valuas are particularly u~eful in
forming ballistic resistant composite~. ~Kevlar 29 ha-
~500 g/denier and 22 g/denier and Kevlar 49 ha~ 1000
g/denier and 22 g/denier a~ value-Q of modulus and
tenacity, re~pectively) Al3c u~e~ul in the practice of
thi~ invenkion i~ poly~metaphenylene i~ophthalamide)
filaments produced commercially by Dupont under the
tradename Nomex .
` In the fibrou~ layer~sj, the filament~ are arranged
in a network which can have variou~ configurations. Por
example, a plurality of fllaments can be grouped toge~her
~o ~orm a twi~ted o~ untwis~ed yarn~ ~he ~ ment~ or
yarn may be ~o~med a~ a ~elt, knitted or woven ~plain,
ba~ket, satLng and crow ~eet weave~, etc.) in~o a network,
wo gl/o~go 2 ~ ~ 9 2~ ~ PCT/ussO/03358 ~`
-14-
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-eilament
yarn wherein the filamen~s are parallel, unidir~ctlonally
s aligned. For example, the filaments may also be ~ocmed
into nonwoven cloth layers be conventional technique~.
In the fibrous layer(s), the ~ilaments are most
p~e~erably dispersed in a continuous phase of a matrix
material whlch pre~erably qubqtantially coat~ each
eilament con~ained in the bundle of eilament. The manner
in which th~ filamènts are di3pecsed may ~ary widely. The
filaments may be aligned in a substantially pacallel,
unidirectional fashion, or filaments may be a}igned in a
multidirectional fashion with ~ilaments may be aligned in
a multidlcectional ~aqhion with filament~ at va~ying
angleq with eàch other. In the pce~erred embodiment~ Oe
this in~ention, ~ilamen~ in each layer are aligned ln a
3ubstantially p~rallel, unidlrectional ~ashlon ~uch a~ in
a pcep~re, pultrud~d ~hee~ and ~he like.
~o ~h~ matrix mAteri~l employad may vary wldely and may
be a metalllc, semi-metallic materlal, an organic mateeial
and/or an inocganic mateelal. The matrix material may be
~lexible ~low modulus) or rigid ~high modulus).
~llustrative oE use~ul high modulu~ or rigid matrix
material~ are thermoplaRtic ce~ins such as polycarbonates,
polyether, ether ketone~, polyarylenesulEides, polyarylene
oxideY, polyestercarbonate~, polyesterimides, and
polyimide~, thermo3etting re~inq such a~ epoxy resin~t
phenolic resins, modified phenolic re-Rins, allylic resins,
alkyd re~ins, unsaturated polyester-~, aromatic vinylesters
as for example the condensation produced of bisphenol A
and methacrylic acid diluted in a vinyl aromatic monomer
(e.g. styrene or vinyl toluene), urethane resin~ and amino
(melamine and area) re~ins; or mixtures thereof. the
major criterion i~ khat ~uch ma~erial holds the Eilamen~s
together, and maintains ~he geome~rical intog~i~y Oe the
~ibrous layer(s~ under the desired condltions.
,
.
: `' ` A::
20S~27~
~ wosl/o~go PCT/US90/033S8
-15~
In the preferred embodiment~ of the invention, the
matrix material is a low modulus elas~omeric material. A
wide variety of elastomeric material~ and formulations may
be u~ilized in the preferred embodiment3 of this -
invention. Representative examples of suitable
elastomeric material~ ~or use in the formation of the
matrix are tho~e which have their structures, properties,
and ormulatlons togeth~r with crosslinking procedure~
summa~ized ln the Encyclopedia o~ Polymer Science, Volume
S in the s~ckion Elastomers-Synthetlc ~John Wiley & Sons
Inc., 1964). For example, any o~ the following
elastomeric materials may be employed: polybutadiene,
polyisoprene, natural rubber, ethylene-propylene
copolymers, ethylene-propylene-diene, terpolymers,
lS poly~ul~lde polymers, polyurethane ~la3tomers,
chlocosul~onaked polyethylene, polychloroprene,
pla~ticized polyvlnylchlo~ide using dioctyl phkhate or
o~her pla~tice~ well known ln the ark, butadi~nu
aarylonLtrlle ela~komer~, poly~isobu~yl~n~ ao-l~oprene),
poly~cryla~es~ polye~tQrs, polyeth~rs, fluoroelastomer~,
silicone ala3tomer~, thermoplastic elastomer~, copolymQrs
o~ e~hylene.
Partiaularly use~ul ela~omer are block copolymers of
conjugated diene~ and vinyl aromatic monomers. Butadiene
and isoprene are prefereed conjugated dien elastomerq.
Styrene, vinyl toluene and t-butyl ~tyrene are p~eferred
conjugated aromatic monomer-q. 310ck copolymers
incorpora~ing polyisoprene may be hydrogenated to produce
thermopla3tic elastomer~ having saturated hydrocarbon
ela tomer segments. The polymer-R may be ~imple tri-block
copolymers of ~he type A-B-A, multiblock copolymer~ of the
type ~AB)n~n-2-10) or radical configuration copolymer~
of the type R-~BA)x(x~3-lSO)~ wherein A i5 a block from
a polyvinyl aromatic monomer and B i9 a block from a
3S conjugated dlen el~9tomer. Many o~ ~he~e polymer~ are
producnd commercially by ~he shell Ch~mical Co. and
de~cribed ~n the bulletin ~Rraton Thermopla~ic Rubber~,
sc-6s-al.
..
WO91~0W90 2 ~ ~ 9 2 71 PCT/US90/03358 ~
-16-
Most preferably, the elastomeric matrix material
consi~t3 essentially of at least one o~ the
aobve-men~i~ned elastomers. The }ow modulus elastomeric
matrice~ may al~o include fillers such as carbon black,
silica, glass microballons, and the like up to an amount
pcefeeably not to exceed about 50% by volume o~ the
elastomeric mate~ial, prefeeably not to exceed about 40~
by waight, and may be extended with oils, may include fice
~e~ardants such as halogenated parafln~, and vulcanized by
sulfur~ peroxide, metal oxl~e, or radiation cure systems
using me~hods well known to ~ubber technologi ts. Blends
of different elastomeric materials may be used toqethee oc
one or more elastomer materials may be blended with one or
more thermoplastic~. Hlgh density, low density, and
linear low denslty polethylene may be C7 oss~linkQd ko
obtain a matri~ mat~rial o~ appropriate properti~s, eithec
alone or a3 blend~. ~n ave~y instance, t~e modulus o~ ~he
elastomerlc matrix ma~erial ~hould nok excded abou~ 6,000
psi ~4l,300 kPa), pre~erably i~ than about S,000 psi
20 ~34,500 kPa), more pre~erably is less than lO00 psi ~6900
kPa) and most pre~e~ably i~ les~ than S00 psi ~3450 kPa).
Xn the pre~erred embodiments of the invention, the
matrix material i~ a low modulus, elastomeric material.
The low modulus ela-4tomeric materia} has a tensile
25 modulus, measured at about 23C, of less than about 6,000
psi (41,300 kPa). Preferably, the tensile modulus of the
elastomeric material is les3 than about 5,000 p-~i (34,500 ~-
kPa), more preferably, is less than l,000 psi (6900 kPa)
and most preferably i3 less ~han about 500 p3i ~3,450 kPa)
to provide even more improved performance The glass
tran-~ition temperature (Tg) of the ela~tomeric material
(as evidenced by a sudden drop in the ductllity and
elasticity of the material is le~s than about O~C
Preferably, the Tg o~ the qlastomeric material is le~s
than a~oUt ~40C, and more pre~rably i~ 1Q8~ than about
-S0C The elastomeric ma~erlal al~o has an elongation ~o
break o~ at least about 50~. Preferably, the elonga~lon
- , ~ !
~-wo 91/004~0 2 0 ~ 9 2 71 PCT/US~0/03358
-17- -
~o break of the elastomeric material is at least about
OO~i, and more ~referably i~ at le~s~ about 300%.
The proportions of matrix to ~ilament in the fibrous
layer(s) i~ not critical and 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 caqe) and upon the rigidity, shape,
heat resistance, wear resiqtance, flam~ability resistance
and other propertie3 desired ~or the compos1te article.
In general, tbe proportion o~ matrix to ~ilament in the
composite may vary from relatively small amount3 where the
amount of matrix is about lO~i by volume of the filaments
to relatively large amounts where the amount o~ matrix i~
up to about 90~ by volume o~ the eilaments. In the
pre~erred embodiment9 o~ this in~ention, ma~rix amount~ of
erom about 15 to abou~ ao~ by volume are employed. All
volume peccents ace baqed on the total volume o~ the
compo~lt~. ~n th~ particula~ly preeeered embodlments Oe
the invention, ballistio-re~l~kank ark~cles Oe the present
invention aontain a eelatively minor proportien of the
matrix te.g., about 10 to about 30~i by volume of
composite), ~ince the ballistic-ee~istant propertles are
almost entirely attributable to the filament, and in the
particularly preferred embodimentq of the invention, the
proportion of the matrix in the composite i~ from about 10
to about 30~i by weight of filament~.
The fibrou~ layert~) can be fabricated using a number
of procedure3. In general, the layers are formed by
molding the combination of the matrix material and
3~ filaments in the de3ired configurations and amounts by
subjecting them to hea~ and pre~sure.
The filament3 may be premolded by sub~ecting them to
beat and pres9ure. For ECPE ~ilaments, moldlng
temperature~ range ~rom abou~ ~0 to about 150C,
pra~e~ably ~rom about 80 ~io about l~S~C, more prQeerably
~rom about 100 to about 135C, and more pre~erably from
about 110 to about 130C. The pressure may ranga ~rom
about 10 pi~i ~69 kpa) ~o about 10,00~ psi t69,000 kpa).
" . . . . .
wo gl/o~go 2 ~ 5 ~ 2 ~ ~ PCT/US90/03358 ~
-18- -
A pressure betw~en about 10 psi 169 kpa) and abou~ 100
psi (690 kpa), when combined with temperatures below about
100C for a period of time less than about 1.0 min., may
be u~ed simply to cause adjacent filament~ to stick
together. Pre~sures from about 100 psi ~6900 kpa) to
about lO,OOO psi (69,00~ kpa), when coupled with
temperatures in the range o~ about 100 to about 155C for
a time of between about 1 to about 5 min., may cause the
~llament~q ~o defoem and to compress together (generally in
a ~llm-like shape) Pr~s~ures From about 100 psi (690
kpa) to aboutlO,OOO psi (69,000 kPa), when coupled with
temperatures in the range of about 150 to about 155C for
a time of between 1 to about 5 min., may cau e the ilm to
become tran~lucent or transparent. Poe polypropylene
Eilaments, the upper limitation o~ the temperature range
would be about 10 to about 20C hlgher ~han ~or ~CPE
~ilament.
~n the prefec~ed ~mbodimen~ o~ khe lnventlon, ~he
~ilament~ ~premoldQd i~ de~ir~d) are precoated wl~h the
desired matrix material prior to belng arranged in a
network and mold a~ dQscribed above. The coating may be
applled to the ~ilaments in a variety o~ way~ and any
method known to those o~ skill in the art or coating
filaments may be used For example, one method is to apply
the matrix material to ~he stretched high modulus
filaments either as a liquid, a sticky 301id or particles
in suRpension, or a~ a fluidized bed. Alternatively, the
matrix material may be applied a~ a -~olution or emulsion
in a ~uitable solvent which does not adversely ~ffect the
propertie3 of the filament at the temperature of
application. In these illustrative embodiments, any
liquid capable of dissolving or dispersing the matrix
material may be u~ed. However, in the preeered
embodiments of the invention in which the ma~riX material
35 i9 an elastomeric materlal, pre~erred gcoups Oe solven~s
include wat~r, para~ln oils, ketono~, alcoholic, aromatic
qolvents or hydrocarbon solvents or mixture~ thereof, with
illustrative specific solvenks including para~f1n oll,
~ WO91/0~90 2 ~ 1 PCT/US90/03358
--19--
xylene, toluene and octane. The techniques used to
di3solve or dispe~se the matrix in the solvent~ will be
thoQe conventionally used for the coating of similar
elastomeric materials on a variety o~ sub3trates.
Other techniques for applying the coating to the
filament~ may be used, including coating of the high
modulus precursor (gel filament) before the high
temperature ~tretchlng operation, either be~oce oc after
cemo~al o~ ~he solvqnt from the ~ilament. The ~ilament
may then be stretched at ele~ated temperatuees to produce
the coated filaments. The gel filament may be pas~ed
through a -qolution of the appropriate matrix material, as
fo~ example an elaQtomeric material di~qolved in parafin
oil, o~ an aromatic o~ aliphatic solvent, under condi~ions
lS to attain the desirad coating. Crystallization o the
polymer in ~he gel filamen~ may or may not hav~ taken
place beeoee the eilamen~ Rasse~ inko khe cooling
80lution. ~lt~rna~lv~l~, the ~1lamen~ may bo ex~rud~d
into a ~luidi~od bed Oe th~ appropri~e m~krix ma~erial in
powder eoem,
The propoetion o~ coating on the coated ilaments or
~abrics may vaey Erom relatively ~mall amount ~e.g. 1~ by
weighk o~ Ellamen~s) to relative large amount~ ~e.g. 150
by weight o~ Eilamentq), depending upon whetheL the
coating material haq any impact or ballistic-reqistant
properties o its own (which i9 generally not the case) and
upon the rigidity, shape, heat re~istance, wear
re-qi~tance, flammability re~istance and other properties
deQired for the complex composite article. In general,
balli3tic-re~istant article~ of the pr~sent inven~ion
containing coated filament~ ~hould have a relatively minor
propor~ion o coating ~e.g., about 10 to a bout 30
percent by volume of ~ilamen~), since the
balli~tic-resi~tant properties are almo~t en~irely
attribu~able to the ~ilament. NevartheleY~ coated
~ilamen~3 wikh higher coa~ing contents may be employed.
Generally, however, when the coating constitute~ greater
than about 60~ ~by voluma o~ ~ilamen~, the coated
. .
1, . ,, ", " " . . ~ ............................... ... .
:. .. ,,, . . ,., . ,. : . -, " ", . "
W091/00490 2 0 ~ ~ ~ 7 ~ PCT/US9~/033~8 ~
-20-
filament is con~olidated with similac coated ~ilaments to
form a simple composite without the u~e of additional
matrix material.
Furthermore, if the filament achieves it~ final
prop~eties only ater a stretching operation or other
manipulative proces~, e.g. solvent exchanging, drying oe
tha like, it is contemplated that the coating may be
applied to a precursoe material o~ the final fllament. In
~uch ca~s, the d~qired and preferred tenacity, modulus
and okher propee~les o~ the ~ilament should be iudged by
continuing ~he manipulative process on th~ filamen~
precursor in a manner corre~pondlng to that employed on
the coated filament precursor. Thus, for example, if the
coating i9 applled to the xerogel 11ament described in
lS U.S. Appllcation Serial No. 572,607 o~ Kavesh et al., and
khe coated xerogel ~llament is then stretched undee de~ined
temperatur~ and ~tretch ~tio conditlon~, then thd
~ilament ~enacity and ~ menk modulu~ value~ would be
mea~ueed on uncoa~ed xerog~l e ll~m~n~. which L~ simllarly
9tretched,
It i9 a pre~ereed a~pect o~ the inventlon that each
~ilament be ~ubstantially aoated with the mat~ix material
~oe th~ production of the ibrou-q layer~) having improved
impact peotection and/or having maximum ballistic
eesistance. A filament i-Q substantially coated by using
any of the coating processes described above or can be
~ubqtantially coated by employing any other process
capable of producing a filament coated essen~ially to the
same degree a~ a filament coated by ~he proce ~e_
deQcribed heretofore ~e.g., by employing known high
pressure molding techniqueR).
The filaments and networks produced thereirom are
formed into the fibrous layee( 9) which is a ~simple
compo3ites~, The term, ~imple composike~, as u9ed herein
is intended to mean composit~s made up o~ one or m~re
layer~ ch o~ the layer3 containing ~ilaments as
described above with a ~ingle ma~or matrix material, which
material may include minor propor~ions of other ma~erials
, , , . . - ~ , . . . , , ~,. . .. .
wo9lto~4so ~ 2~ PCT/US90/033~8
-21-
such as fillers, lubricants or the like as noted ~ -
heretofoce.
The proportion of elastomeric matrix ~aterial to
filament is variable for the Rimple composites, with
matrix material amounts of form about 5% to about 150
Vol %, by volume of the filament, representing ~he broad
general range. Within this range, it is preferred to use
composites having a relatively high Eilament content, such
as compoi31tei~ having only about 10 to abouk 50 Vol ~
matrix material, by volume of khe compoqite, and more
preferably ~rom about 10 to abouk 30 Vol 3 matrix material
by volume of the composite.
Stated another way, the filament netwoek occupies
different pcoportions of the total volume o ~he simple
composite. Pre~erably, however, the ~ilament network
compcii~ci3 at least about 30 volume percent oE the i~imple
composite, ~or balll~ic pro~eckion, th~ ~llam~n~ network
comprii~e~ at leai~t abou~ 50 ~oluma pe~cent, mo~
pre~erably ~bout 70 vulume p~cc~nt, and moi~t pceEerably a~
least about 75 volume peraant, wi~h the ma~rix occupying
the remaining volume.
A partlcularly e~ective technlque or preparing the
~ibrous layer~ i9) ~oe uise ln a preerred composite of thls
inv~ntion compri~ed of subs~ankially parallel,
unidirectionally aligned filaments includes the steps of
pulling a filament or bundles of filaments through a bath
con~aining a ~olution of a matrix material peeferable an
elastomeric matrix material, and citcumferentially winding
this filament into a single sheet-like layer around and
along a bu~dIy of filaments the l~ngth of a suitable form,
such as a cylinder. The solvent i3 then evaporated
leaving a i3heet-like layer of filaments embedded in a
matrix that can be removed Ei~om he cylindrical form.
Alternatively, a plurality of ~ilaments or bundles o~
~llaments can be simul~aneausly pulled through ~hQ bath
containing a sQ1u~ion or dispari3ion o~ a ma~riX ma~erial
and laid down ln closely positioned, i3ubstantially
parallel relation to one another on a sultable surEace.
.: . : . , ,, .,.: . . . , : ,
'' " ' . ".' ' ' ' ' ' ,. ,.' .. , . ~,, ' ' . ' ~'
W091/~0490 2 ~ ~ 27 ~ PCT/US90/033S~ ~'
-22-
Evaporation of the solven~ leaves a sheet-like layer
comprised of filam~nts which are coated with the matrix
ma~erial and which are sub~tantially parallel and aligned
along a common filament direction. The sheet is suitable
s for subsequent processing such as laminating to another
sheet to ~orm composites containing more than one layer.
Similacly, a yarn-type -qimple compo~ite can be
produced by pulling a group o~ ilament bundle~ through
disper-qion oc solut.ion of the matrix mate~ial to
lO sub~tantially coat each oE thQ individual Eilaments, and
then evapora~ing the ~olvent to form the coated yarn. The
yarn can then, for example, be employed to form fabrics,
whic~ in turn, can be used to form more complex compo~ite
structures. Moreover, the coated yarn can al30 be
lS proce99ed into a 9imple compo~ite b~ employing conventional
eilament winding technique3J Eor example, the ~imple
composite can have coated yarn eocmed into overlapping
~ilament lay~c~.
~he number o~ lay~r~ lnaluded in the ~lbrous la~e~t~)
oE may vary widely depending on the uses o~ this
composite. ~he number o~ layers would depend on a number
o~ ~actor~ includin~a the degree of ballistic protection
de3ired and o~her ~1cto~s known to tho~e o~ skill in the
~allistic protection art. In general for thi-q
25 applicakion, the gr~ater the degree o~ protection de~ired,
the greater the number of layers included in the fibrous
layer(3) ~or a given weight of the articl`e. Conversely,
the les~or the degree of balli3tic protectisn required,
the le~sor the number of layer~ required for a given
30 weight of the article. I~ is convenient to charac~erize ?
th~ geometries of the fibrous layer~s~ by the geometries
of the filament~ and then to indicate that tbe matrix
material may occupy paet or all of the void ~pace le~t by
the network o~ ~ilamlents. One ~uch ~uitable arrangement
35 is a plueality o~ la;yqra or lsminat~ in which ~he coa~ed
~ilamQnt~ are arrang~d ln a ~h~e~llke array and aligned
paeallel to one anotlher along a common Eilament
direction. Successive layers o~ 9uch coated,
. . ,, . . , ~.. . . ., . . ~ , . . .
., . . : . ~
. .: .. . . , . ~ .. ~; : . . ,:
20~927 1
WO91/0~90 PCT/U~90~03358
-23
unditectional filament~ can be rotated with re~pect to the
previous layer. An example of such laminate structures
are composites 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 ordec. Other
examples include fabrou~ layer~) composed of layers of
coated, undirectional filaments in which adjacent layers
ace orlented 0 /90 with re3pect to their common filament
dlrection.
One t~chnlque eOr ~ormlng fibcou9 layer~s) having
more ~han one layer lncludes the step~ of arranging coated
ilaments into a de3ired network structure, and then
consolidating and heat setting the overall ~tructure to
cau~e the coating m~terial to ~low and occupy the
remalning vold spaces, thus produclng a continuous
matrice. Anothe~ teahn~que is to arrange layecs or other
structuee~ o~ ao~t~ oe uncoat~d ~ilament ad~acent to and
between variou~ ~orm9, e.g. ~llm~, o~ ~he m~rlx ma~erial
dnd khen to aon~olidate and haa~ ~t the ovecall
~ruckure. ~ ~he albov~ ca~e~ i9 pos~ible that the
matrlx can be caused to stick or ~low wlthout completely
melting ~n general, 1 the matrix matecial i~ cau~ed to
melt, relati~ely llttle pre~ure 19 eequlred to eorm the
composite7 while i~ the matrix material i~ only hated to a
sticking point, generally more pee~ure i~ reguired.
Also, the pres~ure and time to set the composite and to
achieve optimal properties will generally depend on the
nature of the matrix material (chemical composition a~
well as mole~ular weight) and proc~3~ing temperature.
The complex co~posite of the inven~ion includes at
least one rigid layer which is preferably comp~i~ed of an
impact resistant material. Illustrative of useful impact
re~i~tant material~ are ~teel plates, composit~ acmor
plates, ceramic reinforced metallic composi~e~, ceramic
plate~, conccete, an~ hi~h ~rength ~llamqn~ c~mpo~i~e~
~or exampl~, a S-glass, a E-gla~s or an arami~llamen~ and
a high modulu~, re~in matrix ~uch as epoxy or phenolic
resin vinyl e~ter, unsaturated polye~tec, thermopla3tic~,
~ .
,~-. ,. :, . . ~.. , . .. , .. . . ,~ :, .... . .
~ .~ , . :, i : i :; .
;: ~ . . :- .. . , , ; . . .. .
", . 1'. ' '. ". ' '' ' ,, . ' ,. . .
wo gl/o~go 2 0 ~ ~ 2 7 ~ PCT/~S9OtO3358 ~
-24-
Nylon 6, nylon 6,6 or polyvinylidine halide~ rean.
Preferably, the rigid impact resistant layee is one which
is ballistically èffective, such a~ ceramic plates or
ceramic rein~orced metal composites. A desirable
embodiment of our invention i~ the use of a rigid impact
resistant layer which will at lea3t partially deform the
initial impact surface of the projectile or cause the
projectile to shatter such a~ a layer formed of a ceramic
as Eor example aluminum oxide, boron carbide, ~ilicon
~Q carbide, titanium borldes, beryllium oxide and the like
and/or a layer ~o~med ~rom a metal a~ Eor ~xample
stainless steel, copper, aluminum, titanium, and the like
(see Laible, supra, Chapters 5-7 for additional useful
rigid layers).
In the preferred embodiment~ of this invention, the
complex composltes lnclude at ledst one rigid layee
comprised o~ a ceramic material ~uch as aluminum oxide,
s11icon carbide, beron carb1d~ and ti~anlum dlboride. The
variou~ ceramic ~terial~ can be made lnto dlr~eren~
~rade~ havin~ vary~ng phy~1aal propartie~ as de~ired such
as puri~y, densl~y, hacdne~, strength, modulus and the
like by manipulation o~ raw material3 and manufacturing
proce~e~.
U~ually, bettec ballistic performance is obtained
from ceramic material3 of relatively higher purity, high
density, high hardness, high modulus and higher toughness,
and such ma~erials are employed in the mos~ preferred
embodiment3 of the invention.
The shape of the ceramic material can vary widely.
In the mo-~t preferred embodiment3 of the invention, the
ceramic layer is formed from 1at c~ramic tiles of various
sizes.
Ceramic materials for use in this inven~ion can be
made by various peocesses know ~o those o~ ~kill in the
ceramic aet. Typically, a ceramic powdar is prepared from
the raw material by milling and ~ceaening~ The resulting
powder i~ proces~ed ~urthar to aahLeve bet~er
proce~sibility 1n the subsequent proces~e~ by specific
Wosl/oo49o ~ w ~ PCT/US90/0335
-25-
treatments and addition of blending additives know i~ the
art. The resulti~g, proces~ed powder is then cold-formed
into the de-qired ~hape by pres~ing or molding, afterwhich
the -qhaped powder i~ densified by ~intering oc hot
pres-qing a~ elevated temperature. In some cases, the
densified product is fini~hed by machining with diamond oe
other means.
In the more preferred embodiments o~ the invention,
the compo~ite w111 comprl~e at least three layers, one o~
which 1~ compo~ed o~ a ~lbrou~ layer ~uch a3 high
molecular weigh~ polyethylene in a polymer matrix, and a
ceramic layer or a glaqs or glass reinforced layer. It is
even more pre~erred that these compo~iteq alqo include
metal layer, ~uch as a layer compo~ed o~ ~teel In the
mos~ pre~erred embodlments,lthe metal layer is
per~orated The per~orations cause the pro~ectlle ~o
tilt, cotate and preeerably break up into smaller pi~ce~
whlch c~n be ~topp~d by the Eibrou~ laye~ more
e~eectively. Tll~ing or rota~ing ~he pro~ectlle help~
lmprove balll9tia per~ormanc~ becau~e the pro~ectile will
hit the fibrous layer on it~ side rather than by lts nose
enabling the composite ~o rec~ive the Lmpact oYer a
greater ~rea. The degree of perforation may vary widely,
and i9 preferably i3 at lea~t about 20 Vol~ based on ~he
total volume of the metal layer i8 more preferably from
about 20 Vol~ to about 70 volS on the aforementioned ba~i3
and i~ most preferably from about 30 to about 60 Vol%. In
general the ~pacing and 3ize of the perforation in the
metal layer may vary widely. The larger the ~ize of
threat projectile, the larger the spacing and 3ize of
perforation in the metal layer i3 suitable for greater
impact on the ma~ efficiency of the compo~ite. An
example of a perforated ~teel plate i3 ~hown in Fig. 9.
The 9ize o~ the per~oeation may vary widely. In general,
the ~i~e depends on the particular balli~ic ~hrea~ baing
~ountared, and ~9 ~sually o~ ~uch a ~i2e a~ ~o allow
tilting and/or eotation o~ the pro~ectile. The ~hape of
the pecforatlons may also vary widely. Such perforation
.
.
W091/00490 20~ ~ 27 ~ PCT/US9OtO3358
-26-
may be circular, oblong, ~quare, rectangular and the
like. In the preferr~d embodiments of thi~ invention, the
perforations are oblong.
The composites of this invention are useful for the
fabrication of ballistic resistant article such as landing
craft hull and otber type of armoc, and helmets. The
protective power o~ a structure may be expres~ed in term
oE its mass ef~iciency ~m)' The mass efficiency of the
composite o~ thi~ invention exhlbita _upecioc mass
eEfLciency of at leaQt about 2.5. In the preferred
embodimen~s of the invention, the ma_s efficiency is at
least about 3 and in the particularly preferred
embodiments is at least about 3.5. Amongst the~e
particularly preferred embodiments, most pre~erred are
thos~ embodiments in whiah khe mass ee~iciency is at least
about ~Ø
V~ually, a compo~qlte armoe h~s the geome~rical sh~p~
Oe a ~hell or pl~t~ Tha ~pac~ic weigh~ o~ kha shell~
and plate-q can be expre~ed in tarm~ Oe the aceal dan~ity
~A~). The a~eal density corresponds to the weight per
unit area o~ the structure, In the cast of filament
reineoeced compo~ite~, the balli~tic eeaistance o~ which
depends mostly on the filament, another u~eFul weight
characteri3tic is the filament areal denqity oE
compo~ites. This term corre~pond~ to the weight of the
filament reinforcement per unit area of the compo-qite (AD).
The following examples are presented to provide a
more complete~ under~tanding o~ the invention. The
~pecific techniques~ condition~, material~, proportions
and reported data ~et forth to illustrate the principles
of the invention are exemplary and should not be conqtrued
as limiting the 9¢0pe of the invention.
EXAMPLE 1
A b~llistic panel was prepared by molding a plurality
of 3heet~ comprlsed of SpectraR-900 uni-directional high
st~engt~ extended chain polyekhylene ~ECPE) yarn
-- -;wo gltoo490 2 0 ~ 9 2 ~1 PCT/US9~033~
-27-
impregnated with a Kraton D1107 thecmopla~tic elastomer
matrix ( a polystyrene-polyisoprene-polystrene-block co-
polymer having 14 wt3 styrene and a product o~ Shell
Chemical). The yarn had a tenacity of 30 g/deniec,
modulus of l,200 g/denier and energy-to-break of 55
joules/g. The elongation to break of the yarn was 4~,
deniee was 1,200 and individual filament denler was 10, or
118 filaments per yarn end. Each ~ilament ~as a diametec
o~ 0 0014~ ~0.0036 cm).
A to~al o 360 layerq were used, and were ~tacked or
laminated kogethe~ wi~h a 0~90 yarn orientation with
each layet having filament length perpendiculae to the
filament length of the adjacent layers.
The laminated compo~ite panel was then molded between `
two parallel plates o~ 24~ (61 cm) X 24~ ~6l cm~ s~uare at
a temperature o~ 124C and a pre~ure o~ 420 pai ~2900 k
Pa) ~oc a p~riod of 40 minute~. At~r moldlng, khe p~nel
wa3 allowed ~o cool to room temper~tuce ovee a 30 m1nute
perlod. Th~ molded panel mea~ured ~4~ ~6l ~m) X 24~ ~61
cm) X 0.93~ ~2.36 cm), and had an areAl den~i~y o~ 24
kg/m .
A complex ballistic panel was ~abricated u~ing
t~tanium diboride tile ~4~ ~lO.l cm) X 4~ ~10.1 cm)] x
0.858~ ~2.l~ cm) having areal den~ity of 97 kg/m2
~Ceralloy 22$, Ceradyne, Inc.), and the fibrous panel
containing the SpectraR polyethylene fiber. The
titanium diboride tile abutted the fibrou-~ panel. To~al
areal density for the complex ballistic article was 121
Kg/m2.
Using conventional testing procedures, the complex
ballistic article was tested with a d~si~nated projectile
which required approxima~ely 40Q kq/m2 of roll-hardened
armor plate ~R~A) to defeat. The impact veloci~y of ~he
projectile was 3,069 Et/sec ~935 m~ec). In the te~t, the
~5 pcojectile p~netra~ed the kitanium diboride ~ile bu~ only
partlally p~netraked the ~ibrouq compoai~e eormed ~rom ~he
SpectraR ~iber, and l~ kg/m2 o~ the Spectra R
~ . .
.,
.. . ..
.. . ~ ;. . . .
. .
WOgl/00490 2 a~ 927 l PCT/VS9~/03358
-2~- -
composite remained unp~nekrated. The Em of the article
was approximately 3.3~
EXAMPLE I I
S
Using the proceduce of Example I, a complex ballistic
article having the structural Eeatureq ~et forth in Table
I was fabcicated. The feature~ are listed in the oc~er in
which they are exposed to the projectile ducing testing.
TAE~I.E I
Composition of Layer Are
(a) Aluminum oxide Tile
t4~ (10.1 cm) X 4~(10.1 cm)]
obtained rom Coor~ Ceramics
Co. 49 Kg/m2
(b) ~HA steel plat~
~0~ ~50.a cm) X 20~ (50.8 cm),
per~ora~ed wl~h 0~9 cm by
2,1 cm oblong hole9 ob~alned
er~m Detroit Punc~ee and Retaine~
Corporation 19 Kg/m2
(c) Void space 3 in (7.6 cm) -
(d) ~ibrou~ aomposite fromed Erom
Spec~taR Fiber
24~ (61 cm) x 24~ (61 cm)
fabricated as in EXAMPLE I 45 Kg/m2
Total areal den~ity of the article was 113 Kq/m2.
UQing the procedure of Example I, the complex
article ~as struck by ~he projectile at an impact velocity
3~125 ft/sec (953 m/sec)- The projectile
pene~rated the aluminum oxide and steel layers but
20 Kg/m2 of the fibrous SpectraR compo~ite `
unpenetrated. The Em f the complex compo~ite was
approximately 3.5.
`!,', ~ . . ` . . ` ~
~wo ~1/00490 2 0 ~i ~ 2 7 1 P~ S90/03358
-29- .
BXAMPLE III
Using the p~ocedure o Example I, a complex ballii3tic
article havin~ the i~itructural featurei~ set forth in Table
s II was fabricated. The features are lista~ in the oeder in ~ .
WhiCh they are exposed to the projectile during testing.
TABLE II
10 ~ Areal Den3ity
~a) Alumlnum oxlde tlle
t4~ (10~1 cm) X 4~ ~10.1 cm)J
obtained from Coors Ceramics
Co. 49 Kg/m2
15 ~b) Glasis Pabric Reinforced
Panel obtained erom
Martin Maeiet~a Corp.
~20~ ~50.8 cm)l X 20~ ~50.8 c~)] 28 Kg/m2
~c) Space 3~ ~7.S cm)
~d) Plbroui~ Campo3it~ o~
~pectra~ Fib~r
2~ ~61 cm) X 2~ ~61 am)
i ~abrlcated a~ in EXAMP~E I. 45 ~9/M2
Total areal density of the compo~ite wais 122 Kq/m2.
u3ing the pro~edure of Example I, the complex
balligtic aeticle was struck by the projectile at an
impact velocity of 3,058 ~t/9ec ~932 m/8eC). The
projectile penetrated the aluminum oxide tile and glass ~:
reinforced layeri3, but 21 Xq/m2 of the fibroui3
SpectraR compo~ite wais unpenetrated. The Em f the
complex composiite wai3 approximately 3O3
EXAMPLE IV
Using the pro~edure of Example I, a complex balliqtic
article having the structural Eeatures set forth in ~abl~
III wai~ ~abricak~d. ~he ~e~tures are liste~ ~h~ in order
in which kh~y a~e expo~ed ~o the pro~ectile during testingO
wo gl~o~go 2 0 ~ 9 2 7 1 PCT/~S9OJ03358 ~
-30- .
TA~LE III
compo~ition of Layer Aceal DensitY :
(a) Perforated RHA
~teel plate
20~ ~50.8cm) X 20a (50,8 cm)
obtained from ~etroit Punch &
~etainer Corp. 19 Kg/m2
~b) Aluminum Oxide tile
~ ~10.1 cm) X 4~ ~10.1 cm)
1~ ob~ained ~om Coorq Ceramlc~ '.
Co. 49 Kg~m2
~c) Glass fabrlc reineorced panel
20~ ~50.8 cm) X 20~ ~$0.8 cm)
ob~ained from Martin Magietta
Corp. 28 Kg/m2
~d) ~lbrous Composite eoem~d
~rom Spec~raR Fiber
24~ ~61 cm) X 24~ (61 cm)
pLapared a~ in EXAMPLB I. 24 ~g/m2
Total ac~al den~lty toc the compl~x ~ompo~ike w~
l~o k/m .
U~ing the procedure o~ Example I, khe complex article .
wa~ ~truck by the pro~eckile at an impact velocity of
3~047 ~t/~c ~g~9 m/geC). The projectile penQtrated
tha ~teel, aluMlnum oxide and glass reinforced layers, but
2KG~m of fibrous Spectra~ composite was
unpenetrated. The Em of the complex compoRite wa~ :
approximately 3.3.
EXAMPLB V ;~:
Using ~he procedure of ~xample I, a omplex ballistic
artidle having the struckural Eeatures set forth in the
following Table IY was fabeicated. The features are
listed in the order in which they are expo~ed to the
35 projectile during testing. ~
; '
:` '~;,
~5~271
.. WO 9],00490 P~T/US~0/V3358
-31-
TABLE IV
Compo ition of Layer Ar
(a) RHA qteel plate
20~ (50.8 cm) X 20~ (50.3 cm)
perforated with 0.9 cm by
2.1 cm oblong hole~
obtained from Deteoit Punch &
. Retainer Cocp. 19 Kg~m2
~b) Space - 2 in (5.1 ¢m)
~c) Aluminum Oxide tile
4' ~10.1 cm) by 4~ ~10.1 cm)
obtained Erom Coor~ Ceramics Co. 49 Kg/m2
(d) Gla~s Fabric Rein~orced Panel
20- (50.8 cm) by 20~ (50.8 cm) 4S Kg/m2
(e) Space 1~ ~2.54 cm~ -
~f) Fibrous ~ayer Formed ~rom
~pectraR Fiber
12~ ~a. 5 cm) by 12~ ~30.5 cm)
fabricaked a3 in EXAMPLB I 10 Kg/m~
The total areal dan~y Oe ~he complex composl~e was 1~-~
Kq/m2.
U~ing khe procedure o~ B~ample I, the complex article
~ was struck by the pro~ectile at an ~mpact velocity oE
: 3,104 et/9ec ~946 m/8eC), The pro~ectile penetrated
the ~teel, aluminum oxide and glas~ fabric reinforced
layers, bu~ 2 Kg/m2 of fibcous SpectraR composite wa3
: unpenetrated. The Em f the complex compo3ite wa~
approximately 3.2.
.
.
'
