CA2072748A1 - Ballistic resistant composite armor having improved multiple-hit capability - Google Patents

Abstract

A multilayer armor (40) comprising a hard ceramic impact layer (12), a vibration isolating layer (14) position adjacent to said hard impact layer (12) and in contract therewith, and a backing layer (16) attached to said vibration isolating layer (14) on the side opposite the side thereof attached to the hard impact layer (12).

Description

wosl/0763~ PC~/~S90/064;~

2072~
~ALLISTIC RESIST~NT COMPOSITE
ARMOR HAvTNG I~P~OvED MULTIPLE-~IT CAP~B~rITY

~ACKGROUND OF THE INVENTION
1. ~ield o~ the lnvention This invention relates to ballistic resistant composite articles. More particularly, this invention relates to such articles having improved ballistic protection.

2. ~ior Art Ballistic atticles such as bulletproof vests, helmets, structural members of helicopters and other military equipment, vehicle panels, briefcases, raincoats, lS parachutes, and umbrellas containing high strength fibers are known. Fibers conventionall~ used include aramid fibers such as poly (phenylenediamine terephthalamide), graphite fibers, nylon fibers, ceramic fibers, glass fibers and the like. For many applications, such as vests or parts of vests, the fibers are used in a woven or knitted fabric. For many of the applications, the fibers are encapsulated or embedded in a matris material.
In ~The Application of High Modulus Fibers to Ballistic Protection~, R.C. Lia~le et al., J. Macromol.
Sci.-Chem. A7(1), pp. 295-322, 1973, it is indicated on p.
298 that a fourth requirement is that the testile material have a high degree of heat resistance. In an NTIS
publication, AD-A018 958 ~New Materials in Construction for Improved Helmets~, A.L. Alesi et al., a multilayer highly oriented polypropyiene film material (without matris), referred to as ~XP~, was evaluated against an aramid fiber (with a phenolic/polyvinyl butyral resin matris). The aramid system was judged to have the most promising combination of superior performance and a minimum of p~oblems for combat helmet development. USP
4,403,012 and USP 4, 457,985 disclose ballistic resistant composite articles comprised of networks of high molecular - , ~ ~ ,, , ,~, . ..
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, . . . .
, , W09l/07633 2~ PCT/1'590/064~

weight polyethylene or polypropylene fibers, and matrices composed of olefin polymers and copolymers, unsaturated polyester resins, epo~y resins, and other resins curable below the melting point of the fiber.
A.L. Lastnik, et al., "The Effect of Resin concentration and Laminating Pressures on KEVLAR Fabric Sonded with Modified Phenolic Resin~', Tech. Report NATICK/TR-84/030, June8, 1984; disclose that an interstitial resin, which encapsulates and bonds the fibers of a fabric, reduces the ballistic resistance of the resultant composite article.
US Patent Nos. 4,623,574 and 4,748,064 disclose a simple composite structure e~hibits outstanding ballistic protection as compared to simple composites utilizing rigid matrices, the results of which are disclosed in the patents. Particularly effective are weight polyethylene and polypropylene such as disclosed in US Patent No.
4,413,110.
US Patent Nos. 4,737,402 and 4,613,535 disclose comples rigid composite articles having improved impact resistance which comprise a network of high strength fibers such as the ultra-high molecular weight polyethylene and polypropylene dïsclosed in US Patent No.
4,413,110 embedded in an elastomeric matri~ material and at least one additional rigid layer on a major surface of the fibers in the matris. It is disclosed that the composites have improved resistance to environmental hazards, improved impact resistance and are unespectedly effective as ballistic resistant articles such as armor.
U.S. Patent 3,516,890 disclosed an armor plate composite with multiple-hit capability. US Patent No.
4,836,084 discloses an armor plate composite composed of four main components, a ceramic impact layer for blunting the tip of a projectile, a sub-layer laminate of metal sheets alternating with fabrics impregnated with a viscoelastic synthetic material for absorbing the kinetic energy of the projectile by plastic deformation and a backing layer consisting of a pack of impregnated " ' ' ", '' " ''' ,.
. ~
, .
:;

W091/0763~ PCT/~S90/064~
20727~8 fabrics. It is disclosed that the optimum combination of the four main components gives a high degree of protection at a limited wieght per unit of surface area.
Ballistic resistant armor made of ceramic tiles S connected to a metal substrate e~hibit certain properties which substantially reduces the multiple hit capability of the armor. On impact of the projectile, substantial amounts of vibrational energy are produced in addition to the kinetic energy of the impact. This vibrational energy 10 can be transmitted as noise and shock, or can be transmitted to vibration sensitive areas of the armor such as to the ceramic impact layer resulting in a shattering and/or loosing of tiles.

SUMMARY OF THE INVENTION

This invention relates to a multilayer complex ballistic armor comprising:
(a) a hard impact layer comprised of one or more ceramic bodies;
(b) a vibration isolating layer comprising a network of high strength polymeric filaments having a tenacity of at least about 7 grams/denier, a tensile modulus of at least about 160 grams/denier and an energy-to-break of at least about 8 joules/grams and (c) a backing layer comprised of a rigid material.
Through use of the vibration isolating layer, shock and vibration induced by impact of the projectile are minimized. Moreover, the transmission of e~isting shock and vibration which can damage portions of the ceramic layer not hit by the projectile is inhibited which substantially increases the multiple hit capability of the armor.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more fully understood and further advantages will become apparent when reference is , ... .
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WO 91/0~633 P~/l,S90tO64 C~ qr~
made to the following detailed description of the invention and the accompanying drawings in which:
FIG 1 is a prospective view o an armor plate according to this invention showing its essential elements 5 of a ceramic impact layer, a vibration isolating layer and a backing layer;
FIG 2 is a view in cross-section and side elevation of another embodiment of this invention showing a modified vibration isolating layer.
FIG 3 is a view in cross-section and side elevation of a modified embodiment of this invention depicted in FIG
2.
FIG 4 is a view in cross-section and side elevation of an embodiment of this invention having a modified 15 ceramic layer.

~ETAILED DESCRIPTION OF THE INVENTION

The present invention will be better understood by 20 those of skill in the art by reference to the above - figures. Referring to FIG 1, the numeral 10 indicates a ballistic resistant article 10. Article 10, as shown in FIG 1, comprises three maintain components; a ceramic impac'. layer 12, a vibration isolating layer 14, and a 25 backing layer 16. In the preferred embodiments of this invention, ceramic impact layer 12 comprises a plurality of ceramic bodies 18, in the more preferred embodiments of the invention, ceramic impact layer 12 comprises at least about four ceramic bodies 12 and in the most preferred 30 embodiments of the invention, ceramic impact layer 12 -comprises at least about nine ceramic bodies 12, with --those embodiments in which the number of bodies 12 in layer 12 is at least about sisteen being the embodiment of choice.
Ceramic impact layer 12 is e~cellently suitable for blunting the tip of the projectile, particularly because the ceramic material forming layer 12 will retain its hardness and strength despite the high increase in , . . . ........................ . .

': ' ' ' ! ' :
',: , . " ., . ,", : ,' ~O 91/0763 Pcr/~C,so/0 2~727~8 temperature that will occur in the region struck by a projectile. Ceramic impact layer 12 comprises of one or more of ceramic bodies 18.
~ody 18 is formed of a ceramic material. Useful 5 ceramic materials may vary widely and include those materials normally used in the fabrication of cera~ic armor which function to partially deform the initial impact surface of a projectile or cause the projectile to shatter. Illustrative of such metal and non-metal ceramic io materials are those described in C.F. Liable, Ballistic Materials and Penetration Mechanics, Chapters 5-7 (1980) and include single osides such as aluminum oside (A1203), bariu~ oside (~aO), beryllium oxide (BeO), calcium oxide ~CaO), cerium oside (Ce203 and CeO2), 15 chromium oside (Cr203), dysprosium oxide (Dy203), erbium oxide (Er203), europium oside: (EuO, 2 3 u204), (Eul6021), gadolinium oside (Gd203), hafnium oside (HfO2), holmium oxide (Ho203), lanthanum oside (La203), lutetium oxide (Lu203), magnesium oside (MgO), neodymium oxide (Nd203), niobium oside: (NbO, Nb203, and NbO2), (Nb205), plutonium oside: (PuO, Pu203, and Pu02), praseodymium oside: (PrO2, Pr6011, and Pr203), promethium oside (Pm203), samarium oside (SmO and Sm203), scandium oside (Sc203), silicon dioside (SiO2), strontium oside (SrO), tantalum oside (Ta205), terbium oside (Tb203 and Tb407), thorium oside (ThO2), thulium oside (Tm~03), titanium oside: (TiO, Ti2o3~ Ti305 and TiO2.), 30 uranium oside (U02, U308 and U03), vanadium oside (VO, V203, V02 and V205), ytterbium oside (Yb203), yttrium oside (Y203), and zirconium oxide (ZrO2). Useful ceramic materials also include boron carbide, zirconium carbide, beryllium carbide, aluminum 35 beride, aluminum carbide, boron carbide, silicon carbide, aluminum carbide, titanium nitride, boron nitride, titanium carbide, titanium diboride, iron carbide, iron nitride, barium titanate, aluminum nitride, titanium WO9l/07633 PCT/US90/064~5 7 ~ ?~ ~ -6-niobate, boron carbide, silicon boride, barium titanate, silicon nitride, calcium titanate, tantalum carbide, graphites, tungsten; the ceramic alloys which include cordierite/MAS, lead zirconate titanate/PLZT, alumina-titanium carbide, alumina-zirconia, zirconia-cordierite/ZrMAS; the fiber reinforced ceramics and ceramic alloys; glassy ceramics; as well as other useful materials. Preferred materials for fabrication of ceramic body 12 are aluminum o~ide and metal and non metal 10 nitrides, borides and carbides. The most preferred material for fabrication of ceramic body 18 is aluminum o~ide and titanium diboride.
The structure of ceramic body 18 can vary widely depending on the use of the article. For esample, body 18 15 can be a unitary structure composed of one ceramic material or multilayer construction composed of layers of the same material or different ceramic materials.
While in the figures ceramic body 18 is depicted as a cubular solid, the shape of ceramic body 18 can vary 20 widely depending on the use of the article. For example, ceramic body 18 can be an irregularly or a regularly shaped body. Illustrative of a useful ceramic body 18 are cubular, rectangular, cylindrical, and polygonal (such as triangular, pentagonal and hesagonal) shaped bodies. In 25 the preferred embodiments of the invention, ceramic body 18 is of cubular, rectangular or cylindrical cross-section.-The size (width and height) of body 18 can also varywidely depending on the use of article 10. For example, in those instances where article 10 is intended for use in the fabrication of light ballistic resistant composites for use against light armaments, body 18 is generally smaller; conversely where article 10 is intended for use in the fabrication of heavy ballistic resistant composites for use against heavy armaments then body 18 is generally larger.
The ceramic bodies 18 are attached to vibration isolating layer 14 which isolates or substantially isolates vibrational and shock waves resulting from the , - .
, . . .
' '"-: . ''' "' ,. , u091/0763~ PCT/~.~90/064~' _7- 20727~1~
impact of a projectile at a body 18 from other bodies 18 included in layer 12, and reduces the likelihood that bodies 18 not at the point of projectile contact will crack, shatter or loosen. The armor of this invention has S relatively higher efficiency of shock absorbance. The efficiency of shock absorbance can be measured by the number of completely undamaged (i.e. free of cracks and flaws) ceramic bodies 18 immediately adjacent to the body or bodies 18 at the point of impact retained after impact. The % efficiency of shock absorbance can be calculated from the following equation:

% efficiency of shock absorbance , 100% ~ [l-d/t]
where "t" is the theoretical maximum number of ceramic bodies 18 immediately adjacent to the ceramic body or bodies 18 at the point of contact and ~d" is the difference between the theoretical ma~imum number of 20 ceramic bodies 18 minus the actual number of completely undmaged ceramic bodies 18. Ceramic bodies 18 at the point of contact may vary from one for as for e~ample for impacts at the center of a ceramic body 18 or at the corner of a body 18 at the edg-e of ceramic impact layer 12, to two for impacts at the seam of two adjacent ceramic bodies 18 or at the corner of two adjacent ceramic bodies 18 at the edge of impact layer 12 to four where the impact is at the intersecting corner of four adjacent ceramic bodies 18. In the preferred embodiments of the invention, 30 % efficiency of shock absorbance is at least about 70%, in the more preferred embodiments of the invention, the %
efficiency of shock absorbance is at least about 95%, and in the most preferred embodiments of the invention, the %
efficiency of shock absorbance is about 99 to about 100%.
The amount of a surface of vibration isolating layer 14 covered by ceramic bodies 18 may vary widely. In general, the greater the area percent of the surface vibration isolating layer 14 covered or loaded, the more , . . .
:
.
.

WO 91 /07633 PCr/1 ~9~)/064~' poly(acrylamide), poly(N-isopropylacrylamide) and the like, polyesters; polyethers; fluoroelastomers;
poly(bismaleimide); fle~ible epo~ies; ~lexible phenolics;
polyurethanes; silicone elastomers; epoxy-polyamides;
5 poly(alkylene o~ides); polysulfides; fle~ible polyamides;
unsaturated polyesters; vinyl esters, polyolefins, such as polybutylene and polyethylene; polyvinyls such as poly~vinyl formate), poly(vinylbenzoate), poly(vinyl-carbazole), poly(vinylmethylketone), poly(vinyl-methyl 10 ether), polyvinyl acetate, polyvinyl butyral, and poly(vinyl formal); and polyolefinic elastomers.
Preferred adhesives are polydienes such as polybutadiene, polychloroprene and polyisoprene; olefinic and copolymers such as ethylene-propylene copolymers, 15 ethylene-propylene-diene copolymers, isobutylene-isoprene copolymers, and chlorosulfonated polyethylene; natural rubber; polysulfides; polyurethane elastomers;
polyacrylates; polyethers; fluoroelastomer; unsaturated polyesters; vinyl esters; alkyds; flesible epo~y; flesible 20 polyamides; epichlorohydrin; polyvinyls; flesible phenolics; silcone elastomers; thermoplastic elastomers;
copolymers of ethylene, polyvinyl formal, polyvinyl butyal; and poly(bis-maleimide); Blends of any combination of one or more of the above-mentioned adhesive 25 materials. Most preferred adhesives are polybutadiene, polyisoprene, natural rubber, ethylene-propylene copolymers, ethylene-propylene-diene terpolymers, polysulfides, polyurethane elastomers, chlorosulfonated polyethylene, polychloroprene, poly(isobutylene-co-3~ isoprene), polyacrylates, polyesters, polyethers,fluoroelastomers, unsaturated polyesters, vinyl esters, flesible eposy, flesible nylon, silicone elastomers, copolymers of ethylene, polyvinyl formal, polyvinyl butryal. Blends of any combination of one or more of the above-mentioned adhesive materials.
Vibration isolating layer 14 comprises a network of high strength polymeric filaments having a tenacity modulus of at least about 7 grams/denier, a tensile :, - , ,, , . ~ ;
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- ' , , "': '~t l, ","~
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WO91/0763~ PCT/~S90/064~
20727~

modulus of at least about 160 grams/denier and an energy-in-break of at least about 8 joules/gram. The fibers in the vibration isolating layer 14 may be arranged in networks having various configurations. For e~ample, a 5 plurality of filaments can be grouped together to form a twisted or untwisted yarn bundles in various alignment.
In preferred embodiments of the invention, the filaments are aligned substantially parallel and unidirectionally to form a unia~ial layer in which a matri~ material 10 substantially coats the individual filaments. Two or more of these layers can be used to form a layer 14 with multiple layers of coated undirectional filaments in which each layer is rotated with respect to its adjacent layers. An e~ample is a with the second, third, fourth and fifth layers rotated ~45, -45, 90 and 0 with respect to the first layer, but not necessarily in that order.
Other e~amples include a layer 12 with a 0/90 layout of yarn or filaments.
The type of filaments used in the fabrication of layer 14 may vary widely and can be metallic filaments, semi-metallic filaments, inorganic filaments and/or organic filaments. Preferred filaments for use in the practice of this invention are those having a tenacity equal to or greater than about 10 g/d, a tensile modulus 25 egual to or greater than about 150 g/d, and an energy-in-break equal to or greater than about 8 joules/grams. Particularly preferred filaments are those having a tenacity equal to or greater than about 20 g/d, a tensile modulus equal to or greater than about 500 g/d and 30 energy-to-break equal to or greater than about 30 joules/grams. Amongst these particularly preferred embodiments, most preferred are those embodiemnts in which the tenacity of the filaments are equal to or greater than about 25 g/d, and energy-to-break is equal to or greater than about 35 joules/gram. In the practice of this invention, filaments of choice have a tenacity equal to or greater than about 30 g/d and the energy-to-break is equal to or greater than about 40 joules/gram.

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, , W091/07633 PCT/~S90/064~5 ~ 3 -12-Illustrative of useful organic filaments are those composed of polyesters, polyolefins, polyetheramides, fluoropolymers, polyethers, celluloses, phenolics, polyesteramides, polyurethanes, epo~ies, amimoplastics, 5 silicones, polysulfones, polyetherketones, polyetherether-ketones, polyesterimides, polyphenylene sulfides, polyether acryl ketones, poly(amideimides), and polyimides. Illustrative of other useful organic filaments are those composed of aramids (aromatic polyamides), such as poly(m-~ylylene adipamide), poly(p-~ylylene sebacamide), poly 2,2,2-trimethyl-hexamethylene terephthalamide), poly (piperazine sebacamide), poly (metaphenylene isophthalamide) ~Nomex) and poly (p-phenylene terephthalamide) (Kevlar); aliphatic and cycloaliphatic polyamides, such as the copolyamide of 30% he2amethylene diammonium isophthalate and 70%
hexamethylene diammonium adipate, the copolyamide of up to 30% bis-(-amidocyclohe~yl)methylene, terephthalic acid and caprolactam, polyhe~amethylene adipamide (nylon 66), poly(butyrolactam) (nylon 4), poly (9-aminonoanoic acid) (nylon 9), poly(enantholactam) (nylon 7), poly(capryllactam) (nylon 8), polycaprolactam (nylon 6), poly (p-phenylene terephthalamide), polyhesamethylene sebacamide (nylon 6,10), polyaminoundecanamide (nylon 11), 25 polydodeconolactam (nyion 12), polyhe~amethylene isophthalamide, polyhe~amethylene terephthalamide, polycaproamide, poly(nonamethylene azelamide) (nylon 9,9), poly(decamethylene azelamide) (nylon 10,9), poly(decamethylene sebacamide) (nylon 10,10), polytbis-(4-aminocyclothe~yl) methane 1,10-decanedicarbo~amide] (Qiana) (trans), or combination thereof; and aliphatic, cycloaliphatic and aromatic polyesters such as poly(l,4-cyclohe~lidene dimethyl eneterephathalate) cis and trans, poly(ethylene-l, 5-naphthalate), poly(ethylene-2,6-naphthalate), poly(l, 4-cyclohe~ane dimethylene terephthalate) ~trans), poly(decamethylene terephthalate), poly(ethylene terephthalate), poly(ethylene isophthalate), poly(ethylene , ,.

W09l/07633 PCT/~S90/064~;
2~727~8 ~13-o~ybenozoate), poly(para-hydro~y benzoate), poly(dimethylpropiolactone), poly(decamethylene adipate), poly(ethylene succinate), poly(ethylene azelate), poly(decamethylene sebacate), poly(~ ~ -dimethyl-S propiolactone), and the like.
Also illustrative of useful organic filaments are those of liquid crystalline polymers such as lyrotropic liquid crystalline polymers which include polypeptides such as poly ~-benzyl L-glutamate and the like; aromatic 10 polyamides such as poly(l,4-benzamide), poly(chloro-1,4-phenylene terephthalamide), poly(l,4-phenylene fumaramide), poly(chloro-1,4-phenylene fumaramide), poly(4,4'-benzanilide trans, trans-muconamide), poly(l,4-phenylene mesaconamide), poly(l,4-phenylene) lS (trans-1,4-cyclohesylene amide), poly(chloro-1,4-phenylene) (trans-1~4-cyclohesylene amide), poly(l,4-phenylene 1,4-dimethyl-trans-1,4-cyclohesylene amide), poly(l,4-phenylene 2.5-pyridine amide), poly(chloro-1,4-phenylene 2.5-pyridine amide), poly(3,3'-dimethyl-4,4~-20 biphenylene 2.5 pyridine amide), poly(l,4-phenylene 4,4'-stilbene amide), poly(chloro-1,4-phenylene 4,4'-stilbene amide), poly(l,4-phenylene 4,4'-azobenzene amide), poly(4,4'-azobenzene 4,4;-azobenzene amide), poly(l,4-phenylene 4,4'-azosybenzene amide), poly(4,4~-25 azobenzene 4,4'-azosybenzene amide), poly(l,4-cyclohesylene 4,4'-azobenzene amide), poly(4,4'-azobenzene terephthal amide), poly(3.8-phenanthridinone terephthal amide), poly(4,4'-biphenylene terephthal amide), poly(4,4~-biphenylene 4,4'-bibenzo amide), poly(l,4-30 phenylene 4,4'-bibenzo amide), poly(l,4-phenylene 4,4'-terephenylene amide), poly(l,4-phenylene 2,6-naphthal amide), poly(l,5-naphthylene terephthal amide), poly(3,3~-dimethyl-4,4-biphenylene terephthal amide), poly(3,3'-dimethosy-4,4'-biphenylene terephthal amide), 35 poly(3,3~-dimethosy-4,4-biphenylene 4,4'-bibenzo amide) and the like; polyosamides such as those derived from 2,2'dimethyl-4,4'diamino biphenyl and chloro-1,4-phenylene diamine; polyhydrazides such as poly chloroterephthalic , ", . .
,~ ., .',,, ,1 , . . ....
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- . , : ,, , . . . ..
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WOsl/u7633 PC~/~S4~/064 ~ydrazide, 2,5-pyridine dicarboxylic acid hydrazide) poly(terephthalic hydrazide), poly(terephthalic-chlorotere~hthaliC hydrazide) and the like; poly(amide-hydrazides) such as poly(terephthaloyl 1,9 amino-5 benzhydrazide) and those prepared from 4-amino-benzhydrazide, oxalic dihydrazide, terephthalic dihydrazide and para-aromatic diacid chlorides; polyesters such as those of the compositions include poly(o~y-trans-1~4-cyclohe~yleneo~ycarbonyl-trans-l~4-cyclohe~ylenecarbon 10 -b-o~y-l~4-phenyl-eneo~yterephthaloyl) and.poly(oxy-cis-1,4-cyclohe~yleneo~ycarbonyl-trans-1.4-cyclohe~ylenecarbonyl -b-oxy-1,4-phenyleneoxyterephthaloyl) in methylene chloride-o-cresol poly[(oxy-trans-1,4-cyclohexylene-oxycarbonyl-trans-1,4-cyclohe2ylenecarbonyl-b-o~y-(2-methyl-1,4-phenylene)o~y-terephthaloYl)] in 1,1,2,2-tetrachloro-ethane-o-chlorophenol-phenol (60:25:15 vol/vol~vol), poly[o~y-trans-1,4-cyclohesyleneoxycarbonyl-trans-1,4-cyclohe~ylenecarbonyl-b-o~y(2-methyl-1,3-phenylene)o~y-terephthaloyl] in o-chlorophenol and the like;
20 polyazomethines such as those prepared from 4,4~-diaminobenzanilide and terephthalaldephide, methyl-1,4-phenylenediamine and terephthalaldelyde and the like; polyisocyanides such as poly(~-phenyl ethyl isocyanide), poly(n-octyl isocyanide) and the like;
25 polyisocyanates such as poly(n-alkyl isocyanates) as for esample poly(n-butyl isocyanate), poly(n-he~yl isocyanate) and the like; lyrotropic crystalline polymers with heterocylic units such as poly(l,4-phenylene-2,6-benzobisthiazole)(PBT), poly(l,4-phenylene-2,6-30 benzobiso~azole)(P80), poly(l,4-phenylene-1,3,4-02adiazole), poly(l,4-phenylene-2,6-benzobisimidazole), polyt2,5(6)-benzimidazole] (AB-PBI), polyt2,6-(1,4-phneylene)-4-phenylquinoline], poly[l,l'-(4,4~-biphenylene)-6,6'-bis(4-phenylquinoline)] and the like;
polyorganophosphazines such as polyphosphazine, polybispheno2yphosphazine, polytbis(2,2,2' trifluoroethyelene) phosphazine] and the like; metal polymers such as those derived by condensation of ,, , . ' ' " , , ' ': ~ ' .
., , . . ~ . . ',, ; ' , -, : , ' .

.

WO91/07633 PCT/~S()0/064;;
20727~8 trans-bis(tri-n-butylphosphine)platinum dichloride with a bisacetylene or trans-bis(tri-n-butylphosphine)bis(1,4-butadinynyl)platinum and similar combinations in the presence of cuprous iodine and an amide; cellulose and 5 cellose derivatives such as esters of cellulose as for example triacetate cellulose, acetate cellulose, acetate-butyrate cellulose, nitrate cellulose, and sulfate cellulose, ethers of cellulose as for example, ethyl ether cellulose, hydro~ymethyl ether cellulose, hydro~ypropyl 10 ether cellulose, carbo~ymethyl ether celulose, ethyl hydroxyethyl ether cellulose, cyanoethylethyl ether cellulose, ether-esters of cellulose as for example aceto~yethyl ether cellulose and benzoylo~ypropyl ether cellulose, and urethane cellulose as for example phenyl 15 urethane cellulose; thermotropic liquid crystalline polymers such as celluloses and their derivatives as for example hydro~ypropyl cellulose, ethyl cellulose propiono~ypropyl cellulose; thermotropic copolyesters as for e~ample copolymers of 6-hydro~y-2-naphthoic acid and p-hydro~y benzoic acid, copolymers of 6-hydro~y-2-naphthoic acid, terephthalic acid and hydroquinone and copolymers of poly(ethylene terephthalate) and p-hydro~ybenzoic acid; and thermotropic polyamides and thermotropic copoly(amide-esters).
Also illustrative of useful organic filament for use in the fabrication of vibration isolating layer 14 are those composed of e~tended chain polymers formed by polymerization of ,~-unsaturated monomers of the formula:

Rl R2-C ' CH2 wherein:
Rl and R2 are the same or different and are hydrogen,hydrosy, halogen, alkylcarbonyl, carboxy, alkosycarbonyl, heterocycle or alkyl or aryl either unsubstituted or substituted with one or more substituents selected from the group consisting of alkoxy, cyano, hydrosy, alkyl and aryl. Illustrative of such polymers of wos1Jo~63~ ~ PCT/~S90/064 L.B-unsaturated monomers are polymers including polystyrene, polyethylene, polypropylene, poly(l-octadence), polyisobutylene, poly(l-pentene), poly(2-methylstyrene), poly(4-methylstyrene), 5 poly(l-hexene), poly(l-pentene), poly(4-methoxystrene), poly(5-methyl-1-he~ene), poly(4-methylpentene), poly (l-butene), polyvinyl chl~ride, polybutylene, polyacrylonitrile, poly(methyl pentene-l), poly(vinyl alcohol), poly(vinylacetate), poly(vinyl butyral), 10 poly(vinyl chloride), poly(vinylidene chloride), vinyl chloride-vinyl acetate chloride copolymer, poly(vinylidene fluoride), poly(methyl acrylate, poly(methyl methacrylate), poly(methacrylo-nitrile), poly(acrylamide), poly(vinyl fluoride), poly(vinyl formal), poly(3-methyl-lS l-butene), poly(l-pen.tene), poly(4-methyl-1-butene), poly(l-pentene), poly(4-methyl-1-pentence, poly(l-he~ane), poly(5-methyl-1-he~ene), poly(l-octadence), poly(vinyl-cyclopentane), poly(vinylcyclothe~ane), poly(a-vinyl-naphthalene), poly(vinyl methyl ether), poly(vinyl-20 ethylether), poly(vinyl propylether), poly(vinylcarbazole), poly(vinyl pyrolidone), poly(2-chlorostyrene), poly(4-chlorostyrene), poly(vinyl formate), poly(vinyl butyl ether), poly(vinyl octyl ether), poly(vinyl methyl ketone), poly(methylisopropenyl ketone), 25 poly(4-phenylstyrene) and the like.
Illustrative of useful inorganic filaments for use-in the fabrication of vibration isolating layer 14 are glass fibers such as fibers formed from quartz, magnesia aluminosilicate, non-alkaline aluminoborosilicate, soda 30 borosilicate, soda silicate, soda lime-aluminosilicate, lead silicate, non-alkaline lead boroalumina, non-alkaline barium boroalumina, non-alkaline zinc boroalumina, non-alkaline iron aluminosilicate, cadmium borate, alumina fibers which include ~saffil" fiber in eta, delta, and theta phase form, asbestos, boron, silicone carbide, graphite and carbon such as those derived from the carbonization of polyethylene, polyvinylalcohol, saras, polyamide (Nome~) type, nylon, polybenzimidazole, ... . .
",, :, . , , ,,, ,, , ~, , :

.
r; ,, 0 9 1 /07633 Pl / I~S90/064~
207274~

polyoxadiazole, polyphenylene, PPR, petroleum and coal pitches (isotropic), mesophase pitch, cellulose and polyacrylonitrile, ceramic fibers such as those of the ceramic materials discussed earlier for the use in the 5 fabrication of ceramic body 18, metal fibers as for e~ample steel, aluminum metal alloys, and the like.
In the preferred embodiments of the invention, vibration isolating layer 14 is fabricated from a filament network, which may include a high molecular weight 10 polyethylene filament, a high molecular weight polypropylene filament, an aramid filament, a high molecular weight polyvinyl alcohol filament, a high molecular weight polyacrylonitrile filament or mixtures thereof. Highly oriented polypropylene and polyethylene filaments of molecular weight at least 200,000, preferably at least one million and more preferably at least two million may be used in the fabrication of girdle 14. Such high molecular weight polyethylene and polypropylene may be formed into reasonably well oriented filaments by the techniques prescribed in the various references referred to above, and especially by the technique of US Patent Nos. 4,413,110, 4,457,985 and 4,663,101 and preferable US
Patent Application Serial Nos. 895,396, filed Auqust 11, 1986, and 069,~84, filed July 6, 1987. Since 25 polypropylene is a much less crystalline material than polyethylene and contains pendant methyl groups, tenacity values achievable with polypropylene are generally substantially lower than the corresponding values for polyethylene. Accordingly, a suitable tenacity is at least about 8 grams/denier,~ith a preferred tenacity being at least about 11 grams/denier. The tensile modulus for polypropylene is at least about 160 grams/denier, preferably at least about 200 grams/denier.
High molecular weight polyvinyl alcohol filaments having high tensile modulus preferred for use in the fabrication of layer 14 are described in USP 4,440,711 to Y. Kwon, et al., which is hereby incorporated by reference to the e~tent it is not inconsistent herewith. In the . .
, ~ ,, .

WO91/07633 PCT/~S90/0~5 q~ 18-case of polyvinyl alcohol (Pv-OH), PV-OH ilament of molecular weight of at least about 200,000. Particularly useful Pv-OH filament should have a modulus of a~ least about 300 g/denier, a tenacity of at least about 7 5 g/denier (preferably at least about 10 g/denier, ~ore preferably at about 14 g/denier, and most preferably at least about 17 g/denier), and an energy to break o~ at least about 8 joules/g. P(V-OH) filaments having a weight average molecular weight of at least about 200,000, a tenacity of at least about 10 g/denier, a modulus of at least about 300 g/denier, and an energy to break of about 8 joules/g are more useful in producing a ballistic resistant article. P(V-OH) filament having such properties can be produced, for e~ample, by the process 15 disclosed in US Patent No. 4,599,267.
In the case of polyacrylonitrile (PAN), PAN filament for use in the fabrication of layer 14 are of molecular weight of at least about 4000,000. Particularly useful PAN filament should have a tenacity of at least about 10 20 g/denier and an energy-to-break of at least about 8 joule/g. PAN filament having a molecular weight of at least about 4000,000, a tenacity of at least about 15 to about 20 g/denier and an energy-to-break of at least about 8 joule/g is most useful in producing ballistics resistant articles; and such filaments are disclosed, for e~ample, in US 4,535,027.
In the case of aramid filaments, suitable aramid filaments for use in the fabrication of girdle 14 are those formed principally from aromatic polyamide are 30 described in US Patent No. 3,671,542, which is hereby incorporated by reference. Preferred aramid filament will have a tenacity of at least about 20 g/d, a tensile modulus of at least about 400 g/d and an energy-to-break at least about 8 joules/gram, and particularly preferred aramid filaments will have a tenacity of at least about 20 g/d, a modulus of at least about 480 g/d and an energy to -break of at least about 20 joules/gram. Most preferred aramid filaments will have a tenacity of at least about 20 - . , .,, . , " . .: :
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, ~O 9~/0763~ PCr/l~S90/064~
20727~

g/denier, a modulus of at least about 900 g/denier and a~
energy-to-~reak of at least about 30 joules/gram. For example, poly(phenylenediamine terephalamide) filaments produced commerciall~ by Dupont Corporation under the trade name of Kevlar 29, 99, 129 and 149 and having moderately high moduli and tenacity values are particularly useful in forming ballistic resistant composites. Also useful in the practice of this invention is poly(metaphenylene isophthalamide~ filaments produced commercially by Dupont under the trade name Nomex.
In the more preferred embodiments of this invention, layer 19 is formed of filaments arranged in a network which can have various configurations. For example, a plurality of filaments can be grouped together to form a twisted or untwisted yarn The filaments or yarn may be formed as a feltted, knitted or woven (plain, basket, sating and crow feet weaves, etc.) into a network, or formed into a network by any of a variety of conventional techniques. In the preferred embodiments of the invention, the filaments are untwisted mono- ilament yarn wherein the filaments are parallel, unidirectionally aligned. For e~ample, the filaments may also be formed into nonwoven cloth layers be convention techniques.
In the most preferred embodiments of this invention, vibration isolating layer 14 is composed by one or more layers of continuous fibers embedded in a continuous phase of an elastomeric matri~ material which preferably substantially coats each filament contained in the bundle of filaments. The manner in which the filaments are dispersed may vary widely. The filaments may be aligned in a substantially parallel, unidirectional fashion, or filaments may be aligned in a multidirectional fashion, or with filaments at varying angles with each other. In preferred embodiments of this invention, filaments in each layer forming layer 12 are aligned in a substantially parallel, unidirectional fashion such as in a prepreg, pultruded sheet and the like.

WO91/07633 PCT/US90/064~;

wetting and adhesion of filaments in the polymer or matrices, is enhanced by prior treatment of the surface of the filaments. The method of surface treatment may be chemical, physical or a combination of chemical and 5 physical actions. E~amples of purely chemical treatments are used of SO~ or chlorosulfonic acid. Examples of combined chemical and physical treatments are corona discharge treatment or plasma treatment using one of several commonly available machines.
The matri~ material is a low modulus elastomeric material. A wide variety of elastomeric materials and formulation may be utilized in the preferred embodiments of this invention. Representative e~amples of suitable elastomeric materials for use in the formation of the 15 matri~ are those which have their structures, properties, and formulation together with cross-linking procedures summarized in the Encyclopedia of Polymer Science, Volume 5 in the section Elastomers-Synthetic (John Wiley & Sons Inc., 1964). For example, any of the following elastomeric materials may be employed: polybutadiane, polyisoprene, natural rubber, ethylene-propylene copolymers, ethylene-propylene-dien terpolymers, polysulfide polymers, polyurethane elastomers, chlorosulfonated polyethylene, polychloroprene, plasticized polyvinylchloride using dioctyl phthate or other plasticers well known in the art, butadiene acrylonitrile elastomers, poly(isobutylene-co-isoprene), polyacrylates, polyesters, unsaturated polyesters, vinyl esters, polyethers, fluoroelastomers, silicone elastomers, thermoplastic elastomers, and copolymers of ethylene.
Particularly useful elastomers are polysulfide -polymers, polyurethane elastomers, unsaturated polyesters vinyl esters; and block copolymers of conjugated dienes such as butadiene and isoprene are vinyl aromatic monomers such as styrene, vinyl toluene and t-butyl styrene are preferred conjugated aromatic monomers. Block copolymers incorporating polyisoprene may be hydrogenated to produce thermoplastic elastomers having saturated hydrocarbon ,................................. . . . . ... . .
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20727~(~

elastomer segments. The polymers may be simple tri-block copolymers of the type A-B-A, multiblock copolymers o~ the type (AB)n (n-2-10) or radial configuration copolymers o~
the type R-(8A)x (x-3-150); wherein A is a block from a 5 polyvinyl aromatic monomer and ~ is a block rom a conjugated dien elastomer. Many of these polymers are produced commercially by the Shell Chemical Co. and described in the bulletin "Kraton Thermoplastic Rubber", SC-68-81.
Most preferably, the elastomeric matrix material consists essentially of at least one of the above-mentioned elastomers. The low modulus elastomeric matrixes may also include fillers such as carbon black, glass microballons, and the like up to an amount 15 preferably not to exceed about 250% by volume of the elastomeric material, more preferably not to exceed about 100% by weight and most preferably not to exceed about 50%
by volume. The matri~ material may be extended with oils, may include fire retardants such as halogenated parafins, and vulcanized by sulfur, peroxide, metal o~ide, or radiation cure systems using methods well known to rubber technologists. Blends of different elastomeric materials may be blended with one or more thermoplastics. High density, low density, and linear low density polyethylene 25 may be cross-linked to obtain a matri~ material of appropriate properties, either alone or as blends. In every instance, the modulus of the elastomeric matri~
material should not e~ceed about 6,000 psi (41,300 kpa), preferably is less than about 5,000 psi (34,500 kpa), more preferably is less than 500 psi (3450 kpa).
In the preferred embodiments of the invention, the matri~ material is a low modulus, elastomeric material has a tensile modulus, measured at about 23C, of less than about 7,000 psi (41,300 kpa). Preferably, the tensile modulus of the elastomeric material is less than about 5,000 psi (34,500 kpa), more preferably, is less than 1,000 psi (6900 kpa) and most preferably is less than about 500 psi (3,450 kpa) to provide even more improved , ~ ' , - ., ~ ,, " ' : ' ., .. . . .
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WO91/07633 PC~/~S90/064;~

performance. The glass transition temperature (tg) of the elastomeric material (as evidenced by a sudden drop in the ductility and elasticity of the material) is less than about 0 C. Preferable, the Tg of the elastomeric material 5 is less than about -40 C, and more preferably is less than about -50 C. The elastomeric material also has an elongation to break of at least about 50% Preferably, the elongation to break of the elastomeric material is at least about 300%
The proportions of matrix to filament in layer 14 may vary widely depending on a number of factors including, whether the matrix material has any ballistic-resistant properties of its own (which is generally not the case) and upon the rigidity, shape, hèat resistance, wear resistance, flammability resistance and other properties desired for layer 14. In general, the proportion of matrix to filament in layer 14 may vary from relatively small amounts where the amount of matri~ is about 10% by volume of the filaments to relatively large amount where 20 the amount of matri~ is up to about 90% by volume of the filaments. In the preferred embodiments of this invention, matri~ amounts of from about 15 to about 80% by - volume are employed. All volume percents are based on the total volume of layer 14. In the particularly preferrea 25 embodiments of the invention, ballistic-resistant articles of the present invention, girdle 14 contains a relatively `-minor proportion of the matri~ (e.g., about 10 to about 30% by volume of composite), since the ballistic-resistant properties are almost entirely attributable to the 30 filaments, and in the particularly preferred embodiments of the invention, the proportion of the matri~ in layer 14 is from about 10 to about 30% by weight of filaments.
Vibration isolating layer 14 can be fabricated using conventional procedures. For e~ample, in those 35 embodiments of the invention in which vibration isolation layer 14 is a woven fabric, vibration isolating layer 14 can be fabricated using conventional fabric weaving , . . .
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WO9l/07633 ~'CT/~ISgO/064~
20727~g techniques of the type commonly employed for ballistic purposes such as a plain weave or a Panama weave. In those embodiments of the invention in which vibration isolating layer 14 is a network of fibers in a matrix, 5 vibration isolating layer 14 is formed by continuing the combination of fibers and matrix material in the desired co~figurations and amounts, and then subjecting the combination to heat and pressure.
For e~tended chain polyethylene filaments, molding temperatures range from about 20 to about 150 C, preferably from about 80 to about 145 C, more preferably from about 100 to about 135 C, and more preferably from about 110 to about 130 C. The pressure may range from about 10 psi (69 kpa to about 10,000 psi (69,000 kpa). A
15 pressure between about 10 psi (69 kpa) and about 100 psi (690 kpa), when combined with temperatures below about 100 C for a period of time less than about 1.0 min., may be used simply to cause adjacent filaments to stick together. Pressures from about 100 psi to about 10,000 20 psi (69,000 kpa), when coupled with temperatures in the range of about 100 to about 155 C for a time of between about 1 to about 5 min., may cause the filaments to deform and to compress together (generally in a film-like shape). Pressures from about 100 psi (690 kpa) to about 10,000 psi (69,000 kpa), when coupled with temperatures in the range of about 150 to about 155 C for a time of between 1 to about 5 min., may cause the film to become translucent or transparent. For polypropylene filaments, the upper limitation of the temperature range would be about 10 to about 20 C higher than for ECPE filament.
In the preferred embodiments of the invention, the filaments (pre-molded if desired) are pre-coated with the desired matri~ material prior to being arranged in a network and molded into layer 14 as described above. The coating may be applied to the filaments in a variety of ways and any method known to those of skill in the art for coating filaments may be used. For e~ample, one method is to apply the matri~ material to the stretched high modulus W091/07633 PCT/US90/064~;
7 '. ~
~ ~ 7 -24-filaments either as a liquid, a sticky solid or particles in suspension, or as ~luidized bed. Alternatively, the matri~ material may be applied as a solution or emulsion in a suitable solvent which does not adversely affect the 5 properties of the filament at the temperature of application. In these illustrative embodiments, any liquid may be used. However, in the preferred embodiments of the invention in which the matrix material is an elastomeric material, preferred groups of sol~ents include 10 water, paraffin oils, ketones, alcohols, aromatic solvents or hydrocarbon solvents or mistures thereof, with illustrative specific solvents including paraffin oil, ~ylene, toluene and octane. The techniques used to dissolve or disperse the matri~ in the solvents will be those conventionally used for the coating of similar elastomeric materials on a variety of substrates. Other techniques for applying the coating to the filaments may be used, including coating of the high modulus precursor (gel filament) before the high temperature stretching 20 operation, either before or after removal of the solvent from the filament. The filament may then be stretched at elevated temperatures to produce the coated filaments. -' The gel filament may be passed through a solution of the appropriate matris material, as for e~ample an elastomeric 25 material dissolved in paraffin oil, or an aromatic oraliphatic solvent, under conditions to attain the desired coating. Crystallization of the polymer in the gel filament may or may not have taken place before the filament passes into the cooling solution. Alternatively, the filament may be estruded into a fluidized bed of the appropriate matris material in powder form.
The proportion of coating on the coated filaments or fabrics n layer 14 may vary from relatively small amounts of (e.g. 1% by volume of filaments) to relatively large amounts (e.g. 150% by volume of filaments), depending upon whether the coating material has any impact or ballistic-resistant properties of its own (which is generally not the case) and upon the rigidity, shape, heat ..... .. . . .
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~IO9l/07633 PCT/~S90/064;~
2~727~o resistance, wear resistance, flammability resistance and other properties desired for the complex composite article. In general, layer 14 containing coated filaments should have a relatively minor proportion of coating (e.g.
5 about 10 to about 30 percent by volume of filaments), since the ballistic-resistant properties of girdle 19 are almost entirely attributable to the filament. Neverthe-less, coated filaments with higher coating contents may be employed. Generally, however, when the coating 10 constitutes greater than about 60~ (by volume of filament), the coated filament is consolidated with similar coated filaments to forma fiber layer without the use of additional matrix material.
Furthermore, if the filament achieves its final 15 properties only after a stretching operation or other manipulative process, e.g. solvent e~changing, drying or the like, it is contemplated that the coating may be applied to a precursor material of the final filament. IN
such cases, the desired and preferred tenacity, modulus and other properties of the filament should be judged by continuing the manipulative process on the filament precursor in a manner corresponding to that employed on the coated filament precursor. Thus, for esample, if the coating is applied to the serogel filament described in US
25 Application Serial No. 572,607 of ~avesh et al., and the -coated serogel filament is then stretched under defined temperature and stretch ratio conditions, then the filament tenacity and filament modulus values would be measùred on uncoated serogel filament which is similarly strétched.
It is a preferred aspect of the invention that each filament be substantially coated with the matrix material for the production of vibration isolating layer 14. A
filament is substantially coated by using any of the 35 coating processes described above or can be substantially -coated by employing any other process capable of producing a filament coated essentially to the same degree as a filament coated by the processes described heretofore :, , ~ , : ' ' WO9l/07633 ~) PCT/~S90/0~
r ! ~¦ ,L '') - 2 6 -(e.g., by employing known high pressure molding techniques).
The filaments and networks produced therefrom are formed into ~'simple composites~ as the precursor to 5 preparing the complex composite articles of the present invention. The term, "simple composite~, as used herein is intended to mean composites made up of one or more layers, each of the layers containing filaments as described above with a single major matrix material, which 10 material may include minor proportions of other materials such as fillers, lubricants or the like as noted heretofore.
The proportion of elastomeric matrix material to filament is variable for the simple composites, with 15 matrix material amounts of from about 5% to about 150 vol %, by volume of the filament, representing the broad general range. Within this range, it is preferred to use composites having a relatively high filament content, such as composites having only about 10 to about 50 vol %
20 matri~ material, by volume of the composite, and more preferably from about 10 to about 30 vol % matrix material by volume of the composite.
Stated another way, the filament network occupies different proportions of the total volume of the simple 25 composite. Preferably, however, the filament network comprises at least about 20 volume percent of the simple composite. For ballistic protecting, the filament network comprises at least about 50 volume percent, more preferably about 70 volume percent, and most preferably at least about 95 volume percent, with the matrix occupying the remaining volume.
A particularly effective technique for preparing a preferred composite of this invention comprised of substantially parallel, undirectionally aligned filaments includes the steps of pulling a filament or bundles of filaments through a bath containing a solution of a matrix material preferably, an elastomeric matrix material, and circumferentially winding this filament into a single W O 91/07633 P(~r/US90/064~
20727~8 sheet-like layer around and along a bundle of filaments the length of a suitable form, such as a cylinder. The solvent is then e~aporated leaving a sheet-like layer of filaments embedded in a matri~ that can be removed from 5 the cylindrical form. Alternatively, a plurality of filaments or bundles of filaments can be simultaneously pulled through the bath containing a solution or dispersion of a matrix material and laid down in closely positioned, substantially parallel relation to one another on a suitable surface. Evaporation of the solvent leaves a sheet-like layer comprised of filaments which are coated with the matrix material and which are substantially parallel and aligned along a common filament direction. The sheet is suitable for subsequent 15 processing such as laminating to another sheet to form composites containing more than one layer.
Similarly, a yarn-type simple composite can be produced by pulling a group of filament bundles through a dispersion or solution of the matrix material to substantially coat each of the individual filaments, and then evaporating the solvent to form the coated yarn. The yarn can then, for example, be employed to form fabrics, which in turn, can be used to form more complex composite structures. Moreover, the coated yarn can also be 25 processed into a simple composite by employing conventional filament winding techniques; for esample, the simple composite can have coated yarn formed into overlapping filament layers.
The number of layers of fibers included in layer 14 30 may vary widely. In general, the greater the number of layers the greater the degree of ballistic protection provided and conversely, the lesser the number of layers the lesser the degree of ballistic protection provided.
One pre~erred configuration of layer 14 is a laminate in which one or more layers of filaments coated with matris material (pre-molded if desired) are arranged in a sheet-like array and aligned parallel to one another along a common filament direction. Successive layers of such , ,' . , . ~ ~ , .

,, Wo 91 /U~633 ~ c~ PCI /I,'S90/~)64 ~,,, ij,) ,,,, -coated unidirectional filaments can be rotated with respect to the previous layer after which the laminate can be ~olded under heat and pressure to form the laminate.
An example of such a layered vibration isolating layer is 5 the layered structure in which the second, third, fourth and fifth layer are rotated 45, 45, 90 and 0 with respect to the first layer, ~ut not necessarily in that order. Similarly, another e~ample of such a layered layer 12 is a layered structure in which the various 10 unidirectional layers forming girdle are aligned such that the common filament asis is adjacent layers is 0, 90.
Backing layer 16 is comprised of a rigid ballistic material which may vary widely depending on the uses of article 10, and may offer additional ballistic protection.
15 The term ~rigid~ as used in the present specification and claims is intended to include semi-flesible and semi-rigid structures that are not capable of being free standing, without collapsing. The backing material employed may vary widely and may be metallic, semi-metallic material, an organic material and/or an inorganic material.
Illustrative of such materials are those described in G.S.
Brady and H.R. Clauser, ~aterials Handbook, 12th edition (1986). Materials useful for fabrication of backing layer 16 include high modulus polymeric materials such as 25 polyamides as for esample aramids, nylon-66, nylon-6 and the like; polyesters such as polyethylene terephthalate polybutylene terephthalate, and the like, acetalo;
poylsulfones; polyethersulfones; polyacrylates;
acrylonitrile/butadiene/styrene copolymers; poly(amide-imide); polycarbonates; polyphenylenesulfides;polyurethanes, polyphenyleneosides; polyester carbonates;
polyesterimides; polyimides; polyetheretherketone; epo~y resins; phenolic resins; polysulfides; silicones;
polyacrylates; polyacrylics; polydienes; vinyl ester resins; modified phenolic resins; unsaturated polyester;
allylic resins; alkyd resins; melamine and urea resins;
polymer alloys and blends of thermoplastics and/or thermosets of the materials described above; and , ' ' , ' , ~' .: .' ~ , ' ' ', , '. " .
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WO9l/07633 PCT/US90/064~
2~727~

interpenetratins polymer networks such as those of polycyanate ester of a polyol such as the dicyanoes~er of bisphenol-A and a thermoplastic such as a polysulfone.
These materials may be reinforced by high strength 5 filaments described above for use in the fabrication of vibration isolating layer 14, such as aramid filaments, Spectra polyethylene filaments, boron filaments, glass filaments, ceramic filaments, carbon and graphite filaments, and the like.
Useful backing materials also include metals such as nickel, manganese, tungsten, magnesium, titanium, aluminum and steel plate. Illustrative of useful steels are carbon steels which include mild steels of grades AISI 1005 to AISI 1030, medium-carbon steels of grades AISI 1030 to 15 AISI 1055, high-carbon steels of the grades AISI 1060 to AISI 1095, free-machining steels, low-temperature carbon steels, rail steel, and superplastic steels; high-speed steels such as tungsten steels, molybdenum steels, chromium steels, vanadium steels, and cobalt steels;
hot-die steels; low-alloy steels; low-expansion alloys;
mold-steel; nitriding steels for example those composed of low-and medium-carbon steels in combination with chromium and aluminum, or nickel, chromium, and aluminum; silicon steel such as transformer steel and silicon-manganese steel; ultrahigh-strength steels such as medium-carbon low alloy steels, chrominum-molybdenum steel, chromium-nickel-molybdenum steel, iron-chromium-molybdenum-cobalt steeli quenched-and-tempered steels, cold-worked high-carbon steel; and stainless steels such as iron-chromium alloys austenitic steels, and choromium-nickel austenitic stainless steels, and chromium-manganese steel. Vseful materials also include alloys such as manganese alloys, such as manganese aluminum alloy, manganese bronze alloy; nickel alloys such as, nickel bronze, nickel cast iron alloy, nickel-chromium alloys, nickel-chromium steel alloys, nickel copper alloys, nickel-molydenum iron alloys, nickel-molybdenum steel alloys, nickel-silver alloys, nickel-steel alloys;

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~0 91/07633 PCr/l~S90/064;;

iron-chromium-molYbdenUm-CObalt steel alloys; magnesium alloys; aluminum alloys such as those of aluminum alloy 1000 series of commercially pure aluminum, aluminum-manganese alloys of aluminum alloy 300 series, 5 aluminum-magnesium-manganese alloys, aluminum-magnesium alloys, aluminum~copper alloys, aluminum-silicon-magnesium alloys of 6000 series, aluminum-copper-chromium of 7000 series, aluminum casting alloys; aluminum brass alloys and aluminum bronze alloys. Still other materials 10 useful in the fabrication of backing layer 16 are the fiber composites used in the fabrication of vibration isolating layer 14 which comprises fibrous network in a rigid matri~. Yet, other materials useful in the fabrication o~ backing layer 16 are non-shattering glass 15 such as bulletproof glass.
FIG 2 depicts an armor plate composite 20 which differs from the armor plate 10 of FIG 1 as far as the construction of the vibration isolating layer 14 is concerned, corresponding parts being referred to by like 20 numerals. In armor plate 20, vibration isolating layer 14 is composed of three superimposed constituent layers 22, 24 and 26. Layers 22 and 26 are thin layers of a metal or non-metal rigid material such as those materials used in the fabrication of backing layer 16 (preferably a glass-25 filled epo~y resin), and layer 30 is a network ofpolymeric fibers in a matri~ such as those materials discussed herein above for use in the fabrication of vibration isolating layer l4 and is preferably e~tended chain polyethylene fibers in a matri~. Rigid layers 26 30 and 30 function: to improve the overall performance of vibration isolating layer 14; to improve the surface characteristics of vibration isolation layer 14; to provide a surface on which ceramic bodies 12 can be attached; and to retain dimensional stability (i.e.
3S flatness and straightness) of the surface of vibration isolating layer 14 subject to severe impact deformation.
At their contact points, constituent layers 22, 24 and 26 are bonded together with a suitable agent such as an '' ' ' : ' ' ' , u o 9 1 /07633 2 ~ 7 ~ 7 ~ .) ~1--adhesive described above ~or attachment of ceramic bodies 12 to vibration isolation layer 14 as for e~ample a polysulfide or an epo~y. In composite 20, backing layer 16 is of double layer construction and includes rigid 5 layer 28 formed from a metal or rigid polymeric material such as glass filled epoxy resin and ballistic resistant composite and layer 30 formed from high strength fibers such as Spectra polyethylene fibers in a polymeric matrix.
FIG 3 shows a variant of the embodiment of FIG 2, 10 which is indicated at 32. In composite 32, ceramic impact layer 10 is covered with cover layer 34 which functions as an anti-spall layer to retain spall or particles resulting from the shattering of ceramic bodies 18 by the striking projectile, and which functions to maintain ceramic bodies 15 18 which are not hit by the projectile in position. In FIG 3, cover layer 34 consists of top cover 40 and release layer 38. Top cover 36 is formed from a rigid material as for e~ample the metals and non-metals described above for use in the fabrication of backing layer 16 and is 20 preferably composed of a metal such as steel, titanium and aluminum alloys, or of a rigid high strength polymeric composite such as a thermoplastic resin such as a polyurethane, polyester or polyamide, a thermosetting resin such as epo~y, phenolic or vinylester resin or a 25 mi~ture thereof reinforced with polymeric filaments such as aramid or e~tended chain polyethylene or inorganic filaments such as S-glass fibers, silicon carbide fibers, E-glass fibers, carbon fibers, boron fibers and the like.
Release layer 38 is for~ed from materials similar to those 30 used to form vibration isolating layer 14 and functions to eliminate or to substantially reduce the strain on unhit ceramic bodies 18 in the deformation of the composites from impact by the projectile. The construction of vibration isolating layer 14 and backing layer 6 in 35 composite 32 and their materials of construction are the same as in composite 20 of FIG 2.
FIG 4 depicts composite 40, which is a variation of the embodiment of FIG 2. Composite 40 includes ceramic :
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WO 91tO7633 PCr/l,'S90/064~

;~ , ~ 32-body k~taining means 42 between individual ceramic bodies 18 and peripheral impact layer retaining means 44.
Ceramic body retaining means 42 reduces the differences in performance of segmented ceramic impact layer 12 at the 5 seams formed by adjacent ceramic bodies 18 which is usually a weak area, and at the center of ceramic body 18 which is usually a strong area. Ceramic body retaining means 42 also allows ma~imum loading of ceramic bodies 18 in segmented ceramic impact layer 12, provides optimized 10 spacing between adjacent ceramic bodies 18 retains unhit ceramic bodies 18 in place upon severe impact deormation, and transmitts and distributes the impact shock to the entire composite 40 upon impact. Peripheral impact layer retaining means 94 minimizes the differences in the 15 performance at the edges of the composite armor (which because of the segmented nature of the ceramic impact layer 14 tends to be a relatively weak area) and a: the center of the ceramic which tends to be a relatively strong area.
Ceramic body retaininq means 42 and peripheral impact layer retaining means 44 are composed of an "elastic~' material which may vary widely and be metallic, semi-metallic material, an organic material and/or an inorganic material. The term ~elastic~ as used in the present 25 specification and claims is intended to include materials inherently capable of free standing without collapsing.
Illustrative of such materials are those described in G.S.
Brady and H.R. Clauser, Materials Handbook, 12th Edition (1986). Also illustrative useful materials suitable for 30 use in the fabrication of ceramic body retaining means 42 and peripheral impact layer retaining means 44 are those materials described herein abovefor use in the fabricaton of the backing layer 16 and cover layer 34. These materials include in the embodiments of FIGs. 1, 2 and 3 35 high modulus polymeric materials with or without fibrous fillers such as a thermosetting or thermoplastic resin such as a polycarbonate or epo~y which is optionally reinforced by high strength filaments such as aramid . .

WO91/07633 PCT/~S9n/O~S~

filament, Spectra~ e~tended chain polQet~ e~e filaments, boron filament, glass filaments, ceramic filaments, carbon and graphite filament, and the like; metals and metal alloys such as nickel, manganese, tungsten, magnesium, 5 titanium, aluminum, steel, manganese alloys, nickel alloys, magnesium alloys, and aluminum alloys with or without creramic fillers such as silicone carbide; and non-shattering glass such as bulletproof glassdescribed above. The construction of vibration isolating layer 14 10 and backing layer 16 in composite 40 and their mateials of construction are the same as in composite 20 of FIG 2.
Comple~ ballistic articles of this invention have many uses. For esample, such composites may be incorporated into more comple~ composites to provide a lS rigid comples composite article suitable, for esample, as structural ballistic-resistant components, such as helmets, structural members of aircraft, and vehicle panels.
The following esamples are presented to provide a 20 more complete understanding of the invention. The specific techniques, conditions, materials,proportions and reported data set forth to illustrate the principles of the invention are esemplary and should not be construed as limiting the scope of the invention.
EXAMPLE I
.
Eight layers of 16" (40.6 cm) s 16" (40.6 cm) Spectra Fabric (of the style 952 plain 65~d) stitched 30 together with a Spectra 1000 polyethylene fiber were placed between two pieces of 1/32" (0.08 cm) thin glass reinforced eposy plastic sheet (sold by Ryerson Plastics under the trade name GPO-2Grade PEF 2002). The sandwich is placed in a mold. A mixture (100 grams) of a vinyl ester resin (VE 8520 sold by Interplastics), a peroside (Benzoate Peroside) sold by Lucidol under the tradename Luperco AFR-400) and a promoter (N,N,-dimethyl aniline) was poured in the mold until the sandwich surface was , ,., , , : : ':, ,: . ,, - .

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WO91/07633 PCT/US90/064~
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~, completely covered. The composition of the mi~ture of vinyl ester resin/pero~ide/promoter is 10/0.1/0.006. The material was cured for two hours at room temperature under pressure. The thickness of the cured material was about 1/8~ (0.32 cm).

Example 2 A panel consisting of a 4 by 24 checker board with 10 square cells of dimensions of 4" (10.2cm) by 4~ (10.2cm) by 1~2~ (1.3 cm) depth was constructed. The cells of panel were filled with marble tiles. The panel was constructed on a Spectra composite of Example 1. The checker board was placed into a 16" (40.6 cm) by 16~ (90.6 15 cm) by 1/2~ (1.3 cm) aluminum frame, and was covered with a piece of 1/8" (0.32 cm) thick polycarbonate. The whole unit was mounted on a 1/4" (0.64 cm) thick steel plate (AR
400 sold by Ryerson Aluminum and Steel Company), and the entire arrangement was consolidated into a single unit 20 with the thermosetting vinyl ester resin mi~ture used in E~ample 1. After the first shot at the center of tile, 9 neighboring tiles at the point of impact remained undamaged. Thus, the efficiency was 100~. After 5 bullets were shot at a speed of 3100 ft/sec ~944.9 m/secj .
25 at the center of the tiles, 11 tiles were retained. Among these, 9 were undamaged and 2 were slightly cracked.
However, 9 out of 9 of these undamaged tiles were neighboring tiles. Therefore, the efficiency remained 100% after 5 hits. Furthermore, the composite remained flat and straight even though the steal backing plate had buckled after 5 hits.

ComDarative E~ample 1 A panel was constructed using the same procedure described in E~ample 2 with the e~ception that the Spectra composite was not included. ~he panel was tested under the same conditions. After the first shot at the :, . . .
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WO91/07633 PCT/US90/0645~
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center of tile, no neighboring tiles at the point f impact remained undamased. Thus, the efficiency is 0%. After 5 hits, all tiles had shattered. The eficiency re~ained 0%
after 5 hits.
Çom~arative ExamDle 2 A panel was constructed using the same procedure described in E2ample 2 e~cept that a known vibration~and 10 shock isolation material - felt replaced the Spectra composite sandwich. The felt used was a 1/8" (0.32 cm) think 100% dense wool pad (sold by McMaster-Carr under the trade name of 8757Kl with a weight of 1.53 lbs/sq.yd).
The sample was tested under the same conditions described in Esample 2. After the first shot at the center of tile, 2 out of 9 meighboring tiles at the point of impact remained undamaged. Thus, the efficiency was 22~. After 5 hits, 5 tiles were retained but they were slightly cracked. Therefore, the efficiency was 0% after 5 hits.
20 The other tiles were all shattered. The piece of felt used was torn into pieces after 5 shots.

ComDarative EsamDle 3 A panel was constructed using the same procedure as Esample 2 escept that a 1/8~ (0.32 cm) thick glass reinforced eposy composite (GRP) replaced the Spectra~
composite. This GRP is sold hy Ryerson Plastics under the trade name Ryerte~ G-10 PHPP4008. The sample was tested 30 under the same conditions as described in Esample 2.
After the first shot at the center of tile, 1 out of 9 neighboring tiles at the point of impact remained undamaged. Thus the efficiency was 10%. After 5 hits, 2 tiles were retained but were damaged. The remaining tiles 35 were shattered. There~ore, the efficiency was 0% after 5 hits. The GRP was badly damaged after 5 shots.

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Claims (10)

WHAT IS CLAIMED IS:

1. A multilayer complex armor comprising:
(a) hard impact layer comprised of one or more ceramic bodies;
(b) vibration isolating layer positioned adjacent to said hard impact layer and in contact therewith, said vibration isolating layer comprising a network of high strength filaments having a tenacity of at least about 7 grams/denier, a tensile modulus of at least about 169 grams/denier and an energy-to-break of at least about 160 grams.denier and an energy-to-break of at least about 8 joules/gram; and (c) a backing layer comprised of a rigid material attached to said vibration isolating layer of the side opposite the side therof attached to the hard impact layer.

2. The armor of claim 1 which further comprises a cover layer and a realease layer, said release layer being in contact and attached to said hard impact layer opposite to the side therof attached to said vibration isolating layer, and said cover layer in contact with and attached to said release layer on the side opposite to the side thereof attached to and in contact with said hard impact layer.

3. The armor of claim 1 which further comprises:
(a) peripheral retaining means position about and in contact with the periphery of said hard impact layer; and (b) ceramic body retaining means comprising a net work of interconnecting walls positioned about the periphery of each of the ceramic bodies comprising said hard impact layer.

4. The armor of claim 1 wherein said hard impact layer is segmented and comprises a plurality of ceramic bodies.

5. The armor of claim 4 wherein the area of the surface of said vibration isolating layer covered by said ceramic bodies is equal to or greater than about 95 area percent of said vibration isolating layer based on the total surface area of said vibration isolating layer.

6. The armor of claim 4 wherein the area of the surface of said vibration isolating layer covered by said ceramic bodies is equal to or greater than about 95 area percent based on the total area said surface.

7. An armor of claim 1 wherein said fibers are polyethylene fibers, aramid fibers or a combination thereof having a tenacity equal to or greater than about 20 g/d, a tensile modulus of at least about 500 g/denier and an energy-to-break of at least 15 j/d.

8. The armor of claim 1 wherein said vibration isolating layer comprises a network of fibers comprised of two or more layers each of which comprises sheet-like fiber array in which said fibers are arranged substantially parallel to one another along a common fiber direction, with adjacent layers aligned at an angle with respect to the common fiber direction of the parallel fibers contained is said layers.

9. The armor of claim 1 wherein said network of fibers are dispersed in a matrix material having a tensile modulus of greater than about 600 psi (41,300 kpa) measured at 25°C

10. The armor of claim 1 wherein the % efficiency of shock absorbance is at least about 70%.