CA2059271A1 - Ballistic-resistant composite article - Google Patents

Abstract

2059271 9100490 PCTABS00003 A composite ballistic article comprising at least one hard rigid layer (1, 2), at least one fibrous layer (3) and a void layer (4) between said rigid layer and fibrous layer, wherein the relative weight percents of said hard rigid layer and said fibrous layer, and the relative positioning of said layers are such that said article exhibits a mass efficiency equal to or greater than about 2.5.

Description

?~ 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 .. ... ..

Wo91~00490 ~3 ~7~ PCT/U~g~/03358~

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 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 ~

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 ~

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 --10-- .
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, :: . .. , . ..... i i ., ., . ~. .,....... . . ,.. . . ".

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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 ~ ~-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 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 ~`

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 ~

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 ~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 ~

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 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 ~

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 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~ ~' 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 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 :; .

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wo gl/o~go 2 0 ~ ~ 2 7 ~ PCT/~S9OtO3358 ~

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 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 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.

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~

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

~ . .
., .. . ..
.. . ~ ;. . . .
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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 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.
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Claims (10)

WHAT IS CLAIMED IS:

1. A composite article of manufacture comprising:
(a) at least one hard rigid layer comprising one or more hard rigid materials; and (b) at least one fibrous layer comprising a network of filaments having a tensile modulus of at least about 160 grams/denier and a tenacity of at least about 7 g/denier in a matrix;
wherein the relative weight percents of said fibrous layer and said hard rigid layer, and the relative positioning of said layers are such that said article exhibits a mass efficiency equal to or greater than about 2.5.

2. An article according to claim 1 wherein said hard rigid materials are selected from the group consisting of ceramics, metals and fiber reinforced polymers.

3. An article according to claim 1 wherein said article comprises at least two hard rigid layers.

4. An article according to claim 1 wherein at least one of said hard rigid layers is a perforated metal layer.

5. An article according to claim 1 wherein said article further comprises a void layer between the portion of said article comprising at least one of said fibrous layer and the portion of said article comprising at least one of said hard rigid layers.

6. An article according to claim 1 wherein said tenacity is equal to or greater than about 20 g/d, said modulus is equal to or greater than about 500 g/d and said energy-to-break is equal to or greater than about 15 J/g.

7. An article according to claim 1 wherein said network of filaments comprises at least two sheet-like filament arrays, in each array filaments are arranged substantially parallel to one another along a common filament direction, wherein adjacent arrays are aligned at an angle with respect to the longitudinal axis of the parallel filaments contained in said arrays.

a. An article according to claim 1 wherein said network of filaments comprises a non-woven or woven fabric.

9. An article according to claim 1 wherein said filaments are aramid filaments, polyethylene filaments or a combination of aramid and polyethylene filaments.

10. An article according to claim 2 wherein said filaments are polyethylene filaments.