HK1080796A - Ballistic fabric laminates - Google Patents

Description

Ballistic fabric laminates

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Cross Reference to Related Applications

This application relates to a co-pending application entitled "impact resistant rigid composite and method of manufacture" filed on 8/16/2000 with application serial No. 09/639,903.

Background

1. Field of the invention

The present invention relates to woven fabric laminates having superior resistance to puncture by ballistic projectiles, combinations thereof, and methods of making the same.

2. Description of related Art

The construction of body armor for personal protection is an ancient but not old technology. The origin and first use of armor is likely to go back to prehistoric times. Metal armor has been known to egypt 1500 b.c. Fresco in graves dating back to amethotep II domination period (1436 before the c-1411 before the c) clearly show protective clothing formed by overlapping bronze scales. These are sewn into a cloth lining, resembling a long shirt with short sleeves and a collar. ("weapon and Armor History Guide to Arms and Armor)", Steven Bull, edited by Tony North, Studio Editions Inc., London, 1991).

The use of body armor continues until the end of approximately the 17 th century. The weight of the armour is increased in order to maintain effectiveness against rifle fire. At the same time, however, new strategies and tactics require greater infantry mobility. The armor is disabled and is not widely used until world war ii. During world war ii, casualties from sabot fragments rose to 80% and 70% of all wounds affected the trunk, making it urgently desirable to produce a suitable body armor. Bomber personnel and ground forces armor is formed from steel, aluminum and resin bonded fiberglass panels, and heavy nylon cloth.

In recent years, with the introduction of new strong fibers, such as aramid and high molecular weight polyethylene, the weight of body armor has been reduced to a level where daily use by police officers has become practical. In 1974, 132 federal, state and local officers were killed on duty; of them, 128 were killed by the gun, and most of the weapon was a 0.38 caliber or smaller pistol. Lightweight body armor is then introduced very quickly. It is believed that death of an estimated 2,500 police officers was prevented over the next years (Personal Body Armor Selection and Application Guide to Personal Body Armor, National Institute of Justice, 11 months 2001).

There are a variety of compositions for fiber-reinforced composites used in impact resistant articles, such as helmets, plates, and vests. These composites exhibit different resistance to puncture from high velocity impacts such as projectiles, e.g., BB's, bullets, shells (shells), shrapnel, glass fragments, and the like. For example, U.S. patents 6,268,301B1, 6,248,676B 1, 6,219,842B 1; 5,677,029,5,587,230; 5,552,208; 5,471,906, respectively; 5,330,820, respectively; 5,196,252, respectively; 5,190,802, respectively; 5,187,023, respectively; 5,185,195, respectively; 5,175,040, respectively; 5,167,876; 5,165,989, respectively; 5,124,195, respectively; 5,112,667, respectively; 5,061,545; 5,006,390; 4,953,234, respectively; 4,916,000; 4,883,700, respectively; 4,820,568, respectively; 4,748,064; 4,737,402; 4,737,401, respectively; 4,681,792, respectively; 4,650,710; 4,623,574; 4,613,535; 4,584,347, respectively; 4,563,392, respectively; 4,543,286, respectively; 4,501,856, respectively; 4,457,985; 4,403,012; PCT publications WO 91/12136; and E.I. DuPont De Nemours International S.A.1984, entitled "light weight composite Hard armor Systems with T-9633300 dtex DuPont Kevlar 29 fiber," all describe impact resistant composites that include high strength fibers made from materials such as high molecular weight polyethylene, aramid, and polybenzazole. Such composite materials are said to be flexible or rigid, depending on the nature of their structure and the materials used.

U.S. patent 4,737,401, Harpell et al, filed 12/9 1985, and co-pending applications thereof, discloses impact resistant fine woven fabric articles.

U.S. Pat. No. 4,623,574 to Harpell et al, filed 1985 on month 1 and 14, and co-pending applications thereof, discloses simple composites comprising high strength fibers embedded in an elastomeric matrix.

U.S. patent 5,677,029, Prevorsek et al, filed 12/1996, and co-pending applications thereof, discloses a flexible puncture resistant composite material comprising at least one fibrous layer comprising a network of strong fibers, and at least one continuous polymer layer extending through the same space and at least partially bonded to one surface of the fibrous layer.

U.S. patent No. 5,552,208, Lin et al, filed 1993 at 10/29, and co-pending applications thereof, discloses an impact resistant article comprising a high strength fiber web in a matrix and a second matrix material in the form of a film adjacent at least one side of the matrix impregnated fiber web.

U.S. patent 5,471,906, Bachner, jr. et al, discloses a body armor comprising a layer of armor and a cover, surrounding and sealing the layer of armor, comprising a layer of waterproof sheet and a moisture vapor permeable woven fabric oriented to face the wearer.

U.S. Pat. Nos. 5,788,907 and 5,958,804, Brown, Jr, et al, disclose impact-resistant calendered woven fabrics.

Rubber-coated one or both sides of aramid fabric is commercially available from Verseiderag Industrial textile Gmbh under the trade name UltraX. It is also possible to form the rigid plate by bonding rubber-coated fabric under heat and pressure.

Impact resistant composites are typically formed from layers of woven fabric or sheets of fibers that are overlapped together. The fibers in the sheet may be unidirectionally oriented or bonded in a free direction. When the individual layers are unidirectionally oriented fibers, successive layers are rotated relative to each other, for example at an angle of 0 °/90 °, or 0 °/45 °/90 °/45 °/0 °, or at other angles. In previous methods, with some exceptions, individual layers of woven fabric or fibers were typically uncoated or embedded in a polymeric matrix material filled with void spaces between the fibers. The fabric or fibrous sheet is inherently flexible if no matrix is present. The opposite type of construction is a composite material composed of fibers and a single primary matrix material. To build this type of rigid composite, the layers are bonded using heat and pressure to bond the substrates in the layers, form a bond between them, and cure the whole into an article.

Each of the constructs cited above represents an advancement to the goal to which they are directed. However, none describe the specific construction and combination of the laminates of the present invention and none meet all of the needs of the present invention.

These earlier constructions have several disadvantages. Woven fabrics generally have inferior impact resistance compared to cross-lapped unidirectional fiber composites. On the other hand, woven fabrics can be produced at lower cost and with easier equipment than cross-lapped unidirectional fiber composites. The impact resistance of the woven fabric can be enhanced by the addition of a low modulus elastomeric matrix. However, the use of matrix resins that completely fill the interstitial spaces between the fibers increases the weight and reduces the flexibility of the fabric. There is a need for a woven fabric construction that retains the advantages of being less costly and easier to produce than cross-lapped unidirectional composites, but which has impact resistance superior to conventional woven fabrics. Desirably, the woven fabric construction is highly flexible but may be bonded to itself, or to a stiff facing, to form a rigid panel.

Brief description of the invention

The present invention relates to novel fabric laminates having superior resistance to puncture by impact projectiles, combinations thereof, and methods of making the same. In one embodiment, among others, the impact resistant laminate of the present invention comprises: a woven fabric comprising at least 50% by weight of high strength yarns having a tenacity equal to or greater than about 7 grams per denier (g/d), an initial tensile modulus equal to or greater than about 150g/d, an energy to break measured by astm d2256 equal to or greater than about 8J/g; an elastomer coated on at least a portion of at least one side of said woven fabric, said elastomer having an initial tensile modulus as measured by ASTM D638 of equal to or less than about 6,000psi (41.3 MPa); and a plastic film bonded to at least a portion of said elastomer-coated surface.

In another embodiment, the impact resistant laminate of the present invention comprises: a washed and corona treated woven fabric comprising at least a majority of high strength yarns having a tenacity equal to or greater than about 7g/d, an initial tensile modulus of at least about 150g/d, an energy to break of at least about 8J/g; a matrix resin having an initial tensile modulus equal to or greater than about 300,000(2.07GPa) when cured; and a plastic film bonded to at least a portion of one of said fabric surfaces.

The combinations of the present invention include, inter alia, rigid plates wherein at least one component is comprised of multiple groups of the inventive laminates bonded together in a stacked arrangement.

The laminates and combinations of the present invention provide improved impact protection of hard and soft armor.

In one embodiment, the method of the present invention comprises the steps of: forming a woven fabric comprising at least a majority of yarns having a tenacity equal to or greater than about 7g/d, an initial tensile modulus of at least about 150g/d, an energy to break of at least about 8J/g; coating at least a portion of one side of said fabric with an elastomer, said elastomer having an initial tensile modulus equal to or less than about 6,000psi (41.3 MPa); and adhering a plastic film to at least a portion of one of said fabric surfaces.

In another embodiment, the method of the present invention comprises the steps of: forming a woven fabric comprising at least a majority of yarns having a tenacity equal to or greater than about 7g/d, an initial tensile modulus of at least about 150g/d, an energy to break of at least about 8J/g; washing and corona treating said fabric, impregnating said fabric with a matrix resin having an initial tensile modulus equal to or greater than 300,000psi (2.07GPa) when cured; and adhering a plastic film to at least a portion of one of said fabric surfaces.

Detailed Description

The present invention includes novel fabric laminates, combinations thereof, and methods of making the same. In one embodiment, among others, the impact resistant laminate of the present invention comprises: a woven fabric comprising at least 50% by weight of high strength yarns having a tenacity equal to or greater than about 7g/d, an initial tensile modulus of at least about 150g/d, an energy to break as measured by astm d2256 of at least about 8J/g; an elastomer coated on at least a portion of one side of said woven fabric, said elastomer having an initial tensile modulus measured by ASTM D638 of less than about 6,000psi (41.3 MPa); and a plastic film bonded to at least a portion of said elastomer-coated surface.

The present invention also includes impact resistant rigid panels wherein at least one component is comprised of multiple sets of the inventive laminates as just described bonded together in a stacked arrangement.

As used throughout herein, the terms initial tensile modulus, tensile modulus and modulus mean the modulus of elasticity of the yarn as measured by ASTM D2256 and the modulus of elasticity of the elastomeric or matrix material as measured by ASTM D638.

In another embodiment, the impact resistant laminate of the present invention comprises: a laundered and corona treated woven fabric comprising at least 50 weight percent yarn having a tenacity equal to or greater than about 7g/D, an initial tensile modulus of at least about 150g/D, an energy to break as measured by ASTM D2256 of at least about 8J/g; a matrix resin having an initial tensile modulus when cured of equal to or greater than about 300,000psi (2.07GPa) as measured by ASTM D638; and a plastic film bonded to at least a portion of one of said fabric surfaces.

The present invention also includes impact resistant rigid panels wherein at least one component is a plurality of groups of the inventive laminates as just described bonded together in a stacked arrangement.

Although the laminate of the present invention has excellent resistance to piercing by ballistic projectiles, it is contemplated that additional protection will still be required for projectiles designed to pierce armor. Thus, in other embodiments of the invention, the impact resistant rigid plate disclosed above is bonded to one or both surfaces of a component rigid plate comprising one or more metals, ceramics, glasses, metal-filled composites, ceramic-filled composites or glass-filled composites.

For the purposes of the present invention, a fiber is an elongated body having a length dimension that is much greater than the transverse dimensions of width and thickness. Thus, the term fiber includes filaments, ribbons, strips and the like having regular or irregular cross-sections. A yarn is a continuous single yarn composed of a plurality of fibers or filaments.

A complete analysis of fiber reinforced composite punctures is still beyond current capabilities, although several mechanisms have been identified. Small sharp projectiles can pierce the armor by displacing the fibers laterally without breaking them. In this case, the puncture resistance depends on how easily the fibers are pushed aside and, therefore, on the properties of the web. Important factors are the tightness of the weave or periodicity of the cross-overs in the cross-ply unoriented composite, yarn and fiber denier, fiber-to-fiber friction, matrix properties, interlaminar bond strength, and others. Sharp shards can be pierced by the shearing fibers.

The projectile may also break the fibers during drawing. The impact of the projectile on the fabric causes the propagation of a strain wave through the fabric. The impact resistance is greater if the strain wave can propagate through the fiber quickly and without retardation and involves a greater amount of fiber. Experimental and analytical work has shown that in all practical cases, all puncture modes exist and their relative importance is greatly influenced by the composite design.

The fabric portion of the inventive laminate may be any weave texture, including plain weave, twill weave, satin weave, three-dimensional woven fabric, and any of several variations thereof. Plain weave fibers are preferred. More preferably a plain weave fabric having an equal number of warp and weft threads. The preferred warp and fill count of the flat woven fabric is, in turn, related to the denier of the component yarns, as shown in the general ranges in table I.

TABLE I

Range of yarn denier	Preferred range of yarn counts for fabrics
			Warp/inch	Warp/cm
	50-150	60-100			24-39
150-1500			17-60	7-24
	1,500-3,000	13-17			5-7

It should be understood that the foregoing is a general rule and that for any particular combination of materials, fiber denier and yarn denier, it is currently not possible to determine the best preferred weave count. On the one hand, a tighter weave with the most likely coverage is more difficult for a projectile to find holes and push yarns and fibers aside. On the other hand, high frequency yarn crossing limits the propagation of the projectile through the fabric and reduces the fiber volume that can absorb energy from the projectile. For each fibrous material, yarn denier and filament denier, the skilled artisan will readily find its best yarn count by experimentation.

For 1200 denier polyethylene yarns, for example SPECTRA manufactured by Honeywell International Inc^*900 yarns, preferably a plain weave fabric having from about 17 x 17 ends/inch (6.7 ends/cm) to about 45 x 45 ends/inch (17.7 ends/cm). More preferred are plain weave fabrics having from about 19 x 19 ends/inch (7.5 ends/cm) to about 23 x 23 ends/inch (9.0 ends/cm). For 650 denier SPECTRA^*900 polyethylene yarns, preferably a plain weave fabric having from about 20 x 20 ends/inch (7.9 ends/cm) to about 40 x 40 ends/inch (16 ends/cm). For 215 denier SPECTRA^*1000 polyethylene yarns, preferably having a plain weave of from about 40 x 40 ends/inch (16 ends/cm) to about 60 x 60 ends/inch (24 ends/cm).

The woven fabric component of the inventive laminate is preferably washed to remove all of the finish. Preferably, the rinsing process comprises stirring with a solution of a non-ionic surfactant and trisodium phosphate at a temperature of about 50 ℃, followed by rinsing with clear water at about 50 ℃ and drying. For the purposes of the present invention, a rinsed fabric will be understood to have been treated in the manner described above.

The woven fabric is preferably corona treated prior to application of the surface coating or matrix resin. Preferably, the fabric is subjected to a temperature of from about 0.5 to about 3kVA-min/m²Corona treatment. More preferably, the corona treatment is about 1.7kVA-min/m². Suitable corona treatment devices are available from Enercon industries Corp., Menomonee Falls, Wis and from Sherman TreatersLtd., Thame, Oxon.

The woven fabric is preferably calendered prior to corona treatment. Preferably, calendering is performed by passing the woven fabric through a pair of rolls rotating at the same speed and applying a pressure of from about 800 lbs/inch (140kN/m) to about 1200 lbs/inch (210kN/m) of width of the woven fabric at a temperature of from about 100 ℃ to about 130 ℃. The pressure of calendering at about 115 ℃ to about 125 ℃ is preferably about 900 lbs/inch (158kN/m) to about 1000 lbs/inch (175kN/m) of fabric width.

The yarns comprising the fabric component of the inventive laminate may be from about 50 denier to about 3000 denier. The selection is controlled by considering the effectiveness of the impact and the cost. Spun yarn is most expensive to produce and weave, but can produce greater impact effectiveness per unit weight. The yarns in the laminate of the present invention are preferably from about 200 denier to about 3000 denier. More preferably, the yarns are from about 650 denier to about 1500 denier. Most preferably, the yarn is about 800 to about 1300 denier.

The fibers comprising the yarn are preferably from about 0.4 to about 20 denier. More preferably, the fibers are from about 0.8 to about 15 denier. Most preferably, the fibers are from about 1 to about 12 denier.

The cross-section of the fibers used in the present invention may vary widely. They may be circular, flat or oval in cross-section. They may also be irregular or regular multi-lobal with a cross-section having one or more regular or irregular lobes projecting from the linear or longitudinal axis of the fiber. Preferably the fibers are substantially round, flat or oval in cross-section, most preferably the former.

The high tenacity yarns used in the present invention are those having a tenacity equal to or greater than about 7g/d, an initial tensile modulus equal to or greater than about 150g/d, and an energy to break equal to or greater than about 8J/g. For the purposes of this invention, yarn tenacity, initial tensile modulus (modulus of elasticity) and energy to break are measured by ASTM D2256. Preferred yarns are those having a tenacity equal to or greater than about 10g/d, an initial tensile modulus equal to or greater than about 200g/d, and an energy to break equal to or greater than about 20J/g. Particularly preferred yarns are those having a tenacity equal to or greater than about 16g/d, an initial tensile modulus equal to or greater than about 400g/d, and an energy to break equal to or greater than about 27J/g. Most preferred yarns are those having a tenacity equal to or greater than about 22g/d, an initial tensile modulus equal to or greater than about 900g/d, and an energy to break equal to or greater than about 27J/g. In the practice of the present invention, the selected yarns have a tenacity equal to or greater than about 28g/d, an initial tensile modulus equal to or greater than about 1200g/d and an energy to break equal to or greater than about 40J/g.

The yarns and fabrics of the present invention may be comprised of one or more different high strength fibers. The yarns may be comprised of one or more different substantially parallel oriented high strength fibers, or the yarns may be twisted, over-wrapped or entangled, as disclosed in U.S. patent 5,773,370 to Dunbar et al. The fabric of the present invention may be woven with yarns having fibers that differ in the warp and weft directions, or in other directions.

High strength fibers useful in the yarns and fabrics of this invention include highly oriented high molecular weight polyolefin fibers, particularly polyethylene fibers, aramid fibers, polybenzazole fibers such as Polybenzoxazole (PBO) and Polybenzothiazole (PBT), polyvinyl alcohol fibers, polyacrylonitrile, liquid crystal copolyesters, glass, carbon fibers or basalt or other mineral fibers.

Such high molecular weight polyethylene and polypropylene fibers are generally discussed in U.S. Pat. No. 4,457,985, the disclosure of which is incorporated herein by reference and not to be inconsistent herewith. In the case of polyethylene, suitable fibers areThose having an average molecular weight of at least 150,000, preferably at least one million and more preferably two to five million. Such high molecular weight polyethylene fibers may be grown in solution as described in U.S. Pat. No. 4,137,394 issued 10/26 1982 to Meihuzen et al, or U.S. Pat. No. 4,356,138 to Kavesh et al, or spun from solution to form a cement structure as described in Germany Off. 3,004,399 and GB2051667, and in particular as described in U.S. Pat. No. 4,413,110, or polyethylene fibers may be produced by the rolling and drawing process as described in U.S. Pat. No. 5,702,657 and produced by the ITS Industries Inc. in TENSYLON^*The name of (2) sales. As used herein, the term polyethylene means a predominantly linear polyethylene material which may contain minor amounts of chain branching or comonomers not exceeding 5 modifying units per 100 main chain carbon atoms, and which may also contain admixed therewith not more than about 50 wt.% of one or more polymeric additives, such as alkene-1-polymers, particularly low density polyethylene, polypropylene or polybutylene, mono-olefin copolymers containing as a major monomer, oxidized polyolefins, grafted polyolefin copolymers and polyoxymethylenes, or low molecular weight additives such as antioxidants, lubricants, uv screeners, colorants and the like, which are generally incorporated herein by reference.

These fibers can be imparted with a variety of properties depending on the formation technique, draw ratio and temperature, and other conditions. The tenacity of the fibers should be at least 15g/d, preferably at least 20g/d, more preferably at least 25g/d and most preferably at least 30 g/d. Similarly, the initial tensile modulus of the fiber, as measured by an Instron tensile tester, is at least 300g/d, preferably at least 500g/d and more preferably at least 1,000g/d and most preferably at least 1,200 g/d. These highest values of initial tensile modulus and tenacity are generally only obtainable by using a hydroponic or gel-spinning process. Many filaments have a melting point above that of the polymer. Thus, for example, polyethylene having a high molecular weight of 150,000, one and two million typically has a melting point of 138 ℃ in bulk (bulk). Highly oriented polyethylene filaments made from these materials have melting points that are about 7 ℃ to about 13 ℃ higher. Thus, a slight increase in melting point compared to the bulk polymer reflects the crystalline perfection and high crystalline orientation of the fibrils.

Similarly, highly oriented high molecular weight polyethylene fibers having a weight average molecular weight of at least 200,000, preferably at least one million and more preferably at least two million, may be used. Such extended chain polyethylene can be formed into reasonably well oriented filaments by the various techniques given in the various references above, particularly by the technique of U.S. patent 4,413,410. Since polypropylene is a less crystalline material than polyethylene and contains pendant methyl groups, toughness values achievable with polypropylene are generally substantially lower than those achievable with polyethylene. Accordingly, a suitable toughness is at least 8g/d, preferably a toughness value of at least 11 g/d. The initial tensile modulus is at least 160g/d, preferably at least 200 g/d. The melting point of the polypropylene is typically raised by several degrees by the orientation process so that the polypropylene filaments preferably have a major melting point of at least 168 c, more preferably at least 170 c. The particularly preferred ranges of the above-described parameters may advantageously provide improved performance in the final article. The use of filaments having a weighted average molecular weight of at least 200,000 coupled with preferred ranges for the parameters described above (modulus and tenacity) can provide advantageous improved performance in the final article.

High molecular weight polyvinyl alcohol (PV-OH) fibers having a high tensile modulus are described in U.S. Pat. No. 4,440,711 to Kwon et al, which is incorporated herein by reference, and not in contradiction. The high molecular weight PV-OH fibers should have a weight average molecular weight of at least about 200,000. Particularly useful PV-OH fibers should have a modulus of at least about 300g/d, a tenacity of at least about 7g/d, preferably at least about 10g/d, more preferably at least about 14g/d and most preferably at least about 17g/d, and an energy to break of at least about 8J/g. PV-OH fibers having a weight average molecular weight of at least about 200,000, a tenacity of at least about 10g/d, a modulus of at least about 300g/d, and a fracture energy of about 8J/g are more useful in producing impact resistant articles. PV-OH fibers having such properties can be produced, for example, by the methods disclosed in U.S. patent 4,599,267.

In the case of Polyacrylonitrile (PAN), the PAN fibers should have a weight average molecular weight of at least about 400,000. Particularly useful PAN fibers have a tenacity of at least about 10g/d and an energy to break of at least about 8J/g. PAN fibers having a molecular weight of at least about 400,000, a tenacity of at least about 15-20g/d and an energy to break of at least about 8J/g are most useful; such fibers are disclosed, for example, in U.S. Pat. No. 4,535,027.

For aramid fibers, suitable fibers formed from aramid are described in U.S. Pat. No. 3,671,542, which is incorporated herein by reference. Preferred aramid fibers have a tenacity of at least about 20g/d, an initial tensile modulus of at least about 400g/d and an energy to break of at least about 8J/g, and particularly preferred aramid fibers have a tenacity of at least about 20g/d and an energy to break of at least about 20J/g. The most preferred aramid fibers have a tenacity of at least about 20g/d, a modulus of at least about 900g/d and an energy to break of at least about 30J/g. Such as Dupont corporation (Dupont corporation) under the trade name KEVLAR^*Poly (p-phenyleneetherephthalamide) filaments that are commercially produced and have moderately high modulus and tenacity values are particularly useful in forming impact resistant composites. KEVLAR 29 and KEVLAR 49 have initial tensile modulus and tenacity values of 500g/d and 22g/d and initial tensile modulus and tenacity values of 100g/d and 22g/d, respectively. Dupont corporation (Dupont corporation) is available under the name NOMEX^*Commercially produced poly (m-phenylene isophthalamide) s are also useful in the practice of the present invention.

In, for example, U.S. Pat. nos. 3,975,487; suitable liquid crystal copolyester fibers for use in the practice of the present invention are disclosed in U.S. Pat. Nos. 4,118,372 and 4,161,470.

In, for example, U.S. Pat. nos. 5,286,833; 5,296,185; 5,356,584; suitable polybenzole fibers for use in the practice of the present invention are disclosed in U.S. Pat. Nos. 5,534,205 and 6,040,050. Preferably, the polybenzazole fiber is ZYLON from Toyobo co^*The brand fiber.

The elastomers useful in the laminates of the present invention preferably have an initial tensile modulus (modulus of elasticity) of equal to or less than about 6,000psi (41.4MPa) as measured by ASTM D638. More preferably, the elastomer has an initial tensile modulus equal to or less than about 2,400psi (16.5 MPa). Most preferably, the elastomer has an initial tensile modulus equal to or less than about 1,200psi (8.23 MPa).

A wide variety of elastomeric materials and formulations having suitably low moduli may be used in the present invention. For example, any of the following materials may be used: polybutadiene, polyisoprene, natural rubber, ethylene-propylene copolymers, ethylene-propylene-diene terpolymers, polysulfide polymers, polyurethane elastomers, chlorosulfonated polyethylene, polychloroprene, plasticized polyvinyl chloride, the use of dioctyl phthalate or other plasticizers well known in the art, butadiene acrylonitrile elastomers, poly (isobutylene-co-isoprene), polyacrylates, polyesters, polyethers, fluoroelastomers, silicone elastomers, thermoplastic elastomers, copolymers of ethylene.

Preferably, the elastic material does not adhere too well or too loosely to the textile material. Preferred for the polyethylene fabric are block copolymers of conjugated dienes and vinyl aromatic copolymers. Butadiene and isoprene are preferred conjugated diene elastomers. Styrene, vinyl toluene and t-butyl styrene are preferred conjugated aromatic monomers. The block copolymer with the addition of polyisoprene can be hydrogenated to produce a thermoplastic elastomer having a saturated hydrocarbon elastomer portion. The polymer may be of the simple type R (BA)_x(x ═ 3 to 150) triblock copolymers; wherein A is a block of a polyvinyl aromatic monomer and B is a block derived from a conjugated diene elastomer. Many of these Polymers are commercially produced by Kraton Polymers, inc.

The low modulus elastomer may be compounded with fillers such as carbon black, silica, and the like and may be extruded with oil and cured by sulfur, peroxides, metal oxides, or radiation cure systems using methods well known to rubber technologists. Blends of different elastomeric materials may be used together or one or more elastomers may be mixed with one or more thermoplastics.

The elastomeric coating preferably forms about 1 to about 10 percent by weight of the inventive laminate. More preferably, the elastomeric coating forms about 2 to about 8 percent by weight of the laminate.

The elastomer coating may also be applied by spraying or rolling the elastomer solution onto the surface of the woven fabric, followed by drying. Alternatively, the elastomer may be formed into a film or sheet and applied to the woven fabric surface by pressure and/or heat. The block copolymer elastomer of styrene-isoprene-styrene or styrene-butadiene-styrene is preferably applied by roller coating of the solution and subsequently dried.

The matrix resin useful in the laminate of the present invention preferably has an initial tensile modulus (modulus of elasticity) equal to or greater than about 300,000psi (2.07GPa) as measured by ASTM D638. More preferably, the matrix resin has an initial tensile modulus equal to or greater than about 400,000psi (2.76 GPa).

Matrix resins useful in the laminates of the present invention include thermosetting allylic resins, amino, cyanate, epoxy, phenolic, unsaturated polyesters, bismaleimides, rigid polyurethanes, silicones, vinyl esters and copolymers and blends thereof. It is important that only the matrix resin has the requisite initial tensile modulus. Thermosetting vinyl ester resins are preferred. Preferably, the vinyl ester is an ester produced by esterification of a polyfunctional epoxy resin with an unsaturated monocarboxylic acid, typically methacrylic acid or acrylic acid. Exemplary vinyl esters include diglycidyl adipate, diglycidyl isophthalate, di- (2, 3-epoxybutyl) adipate, di- (2, 3-epoxybutyl) oxalate, di- (2, 3-epoxyhexyl) succinate, di- (3, 4-epoxybutyl) maleate, di- (2, 3-epoxyoctyl) pimelate, di- (2, 3-epoxybutyl) phthalate, di- (2, 3-epoxyoctyl) tetrahydroterephthalate, di (4, 5-epoxydodecyl) maleate, di (2, 3-epoxybutyl) terephthalate, di- (2, 3-epoxypentyl) thiodipropionate, di- (5, 6-epoxytetradecyl) diphenyldicarboxylate, bis- (3, 4-epoxyheptyl) sulfonyl dibutyrate, tris- (2, 3-epoxybutyl) -1, 2, 4-butanetricarboxylate, bis- (5, 6-epoxypentadecyl) maleate, bis- (2, 3-epoxybutyl) nonanedioate, bis- (3, 4-epoxypentadecyl) citrate, bis- (4, 5-epoxyoctyl) cyclohexane-1, 3-dicarboxylate, bis- (4, 5-epoxyoctadecyl) malonate, bisphenol a-fumaric polyester, and similar materials.

Most preferred are epoxy resins based on vinyl ester resins, such as DERAKANE manufactured by Dow Chemical Company^*And (3) resin.

The matrix resin preferably forms about 5 to about 25 percent by weight of the laminate. More preferably, the matrix resin forms about 5 to about 15 percent by weight of the laminate.

The matrix resin is preferably applied to the uncured liquid matrix resin or solution of matrix resin by dip coating of the woven fabric to complete the impregnation.

Plastic films useful in the laminate of the present invention may be selected from: polyolefins, polyamides, polyesters, polyurethanes, vinyl polymers, fluoropolymers and copolymers and mixtures thereof. Preferably, the plastic film does not adhere too well or too loosely to the elastomeric coating or matrix resin. When the elastomeric coating is a block copolymer of a conjugated diene and a vinyl aromatic copolymer, the plastic film is preferably a linear low density polyethylene. Similarly, when the matrix resin is a vinyl ester resin, the plastic film is preferably linear low density polyethylene.

The plastic film is preferably 0.0002 inches (5.1 microns) to about 0.005 inches (127 microns) in thickness. More preferably, the plastic film is about 0.0003 inches (7.6 microns) to about 0.003 inches (76 microns) in thickness.

The plastic film preferably forms about 0.5 to about 5 percent by weight of the laminate. Preferably the plastic film is biaxially oriented. The plastic film is preferably bonded to the base material of the laminate by heat and pressure.

In other embodiments, the present invention comprises methods of forming the inventive laminates. In one embodiment the process of the invention comprises the steps of: forming a woven fabric comprising at least a majority of high strength yarns having a tenacity equal to or greater than about 7g/d, an initial tensile modulus of at least about 150g/d, an energy to break of at least about 8J/g; coating an elastomer on at least a portion of one side of said woven fabric, said elastomer having an initial tensile modulus equal to or less than about 6,000psi (41.3 MPa); and adhering a plastic film to at least a portion of said elastomer-coated surface.

Preferably, the woven fabric is washed, calendered and corona treated. Preferably, calendering is performed by passing the woven fabric through a pair of rolls rotating at the same speed and applying a pressure of from about 800 lbs/inch (140kN/m) to about 1200 lbs/inch (210kN/m) of width of the woven fabric at a temperature of from about 100 ℃ to about 130 ℃.

In another embodiment, the method of the present invention comprises the steps of: forming a woven fabric comprising at least a majority of yarns having a tenacity equal to or greater than about 7g/d, an initial tensile modulus of at least about 150g/d, an energy to break of at least about 8J/g; washing and corona treating said woven fabric and impregnating said fabric with a matrix resin having an initial tensile modulus equal to or greater than 300,000psi (2.07GPa) when cured; and adhering a plastic film to at least a part of one surface of said woven fabric.

The woven fabric is preferably calendered after washing and before corona treatment.

The following examples are given to provide a more complete understanding of the invention. Specific techniques, conditions, materials, proportions and reported data set forth to illustrate the principles of the invention are exemplary and should not be construed as limiting the scope of the invention.

Examples

Example 1 (comparative example)

1200 denier x 120 filament polyethylene yarn designated SPECTRA from Honeywell International Inc^*900 having a tenacity characteristic of 30g/d, an initial tensile modulus of 850g/d and an energy to break of 63J/g, are woven into a plain weave fabric of 21 x 21 ends/inch (8.27 ends/cm). Washing the woven fabric to remove the finish and at 1.7kVA-min/m²And (4) performing lower corona treatment.

Example 2 (comparative example)

Washing, calendering and heating at 1.7kVA-min/m²The same polyethylene woven fabric as described in comparative example 1 was corona treated. The woven fabric was calendered at 121 c by passing it through a pair of rolls rotating at the same speed and applying a pressure of 952 lbs/inch (163kN/m) width of the woven fabric.

Example 3 (comparative example)

Washing and washing at 1.7kVA-min/m²The same polyethylene woven fabric as described in comparative example 1 was corona treated. By passing the fabric, polyethylene film and outer polyester release layer at 121 c and a rolling pressure of 635 lbs/inch (109kN/m) through a pair of rollers operating at the same speed, a linear low density polyethylene film having a thickness of 0.00035 inch (8.89 microns) was laminated to one side of the fabric. The release layer is then peeled from the polyethylene fabric laminate. The polyethylene constituted 3.5 wt.% of the laminate.

Example 4 (comparative example)

Washed, calendered as described in comparative example 2 and at 1.7kVA-min/m²The same polyethylene woven fabric as described in comparative example 1 was corona treated. From 20% by weight of a styrene-isoprene-styrene block copolymer elastomer designated KRATON^*The cyclohexane solution of D1107 was applied to the fabric surface. After drying, the elastomer constituted 5 wt.% of the coated fabric. Neat KRATON^*The initial modulus of elasticity of D1107 was 200psi (1.38 kPa).

Example 5

Washing and washing at 1.7kVA-min/m²The same polyethylene woven fabric as described in comparative example 1 was corona treated. One side of the fabric was coated with 5 wt.% KRATON as described in example 4^*D1107 elastomer coating. A linear low density polyethylene film having a thickness of 0.00035 inch (8.89 mm) was laminated to the elastomer-coated fabric surface at 121 c and a rolling pressure of 635 lbs/inch (109 kN/m). Thereby forming the laminate of the present invention.

Example 6

Washed, calendered as described in comparative example 2 and at 1.7kVA-min/m²The same polyethylene woven fabric as described in comparative example 1 was corona treated. From 20% by weight of a styrene-isoprene-styrene block copolymer elastomer designated KRATON^*The cyclohexane solution of D1107 was applied to the fabric surface. A linear low density polyethylene film having a thickness of 0.00035 inch (8.89 mm) was laminated to the elastomer-coated fabric surface at 121 c and a rolling pressure of 635 lbs/inch (109 kN/m). Thereby forming the laminate of the present invention.

Impact test

The impact targets were formed from each of the fabrics and laminates described in comparative examples 1-4 and examples 5 and 6. Each impact target consisted of an 18 x 18 inch (45.7 x 45.7 cm) square of 19 of the material prepared in the examples. Squares are packed together to form the target without any connections that join into an overlap.

The impact resistance of the target was evaluated according to the National Institute of Justice NIJ0101.03 using 124 (8.0g) pellets lined with clay and 9mm all-metal jacketed. The areal density of the target, the speed at which 50% of the projectiles failed to penetrate the target (V50) and the Specific Energy Absorption (SEAT) of the target are listed in table II below.

Observing comparative example 2 in comparison to comparative example 1, it can be seen that calendering of the fabric substantially increases its impact effectiveness (SEAT: 72 to 34).

Observation of the comparison of comparative example 3 with comparative example 2 shows that laminating a polyethylene film to a fabric rather than calendering similarly increases impact effectiveness to nearly the same extent (SEAT: 68 to 72).

Observation of the comparison of comparative example 4 with comparative example 2 shows that 5 wt.% of a low modulus elastomeric coating on one side of the calendered fabric further increased impact effectiveness (SEAT: 100 to 72).

Surprisingly, example 5, a laminate of the present invention, comprising an uncalendered woven fabric, and a low modulus elastomeric coating of the fabric surface and a plastic film bonded to the elastomeric coated surface, exhibits superior impact resistance (SEAT: 112) to any of the foregoing fabrics or laminates. Also surprisingly, example 6, a laminate of the present invention, comprising the same low modulus elastomeric coating on a calendered fabric and plastic film, although the best of all, showed a small further increase in impact resistance (SEAT: 117).

Without being held to a particular theory, it is believed that the low modulus elastomer in the laminate of the present invention acts to increase the friction between yarns and between filaments in a yarn and thus makes it more difficult for the projectile to push filaments and yarns aside. It is believed that the plastic film functions to aid in the propagation of the strain wave caused by the projectile impact and involves a greater amount of fiber. As a result, the elastomer and plastic film work together requiring the projectile to break more high tensile yarns and dissipate more energy.

TABLE II

Impact properties of the target

The components of the fabric are as follows: 1200 denier SPECTRA^*900; 21 x 21 ends/inch

Example No. 2	Fabric treatment	Elastomer, wt. -%)	PE film, wt. -%)	Target areal density, kg/m2	V50		SEAT，J-m2/kg
								ft/sec	m/sec
					Comparative example 1	SC，CT				0	0	4.26	618	188.4	34
Comparative example 2	SC，CAL，CT	0	0	4.26			903	275.2	72
					Comparative example 3	SC，CT				0	3.5	4.41	894	272.5	68
Comparative example 4	SC，CAL，CT	5	0	4.56			1105	336.8	100
					5	SC，CT				5	3.5	4.93	1215	370.3	112
6	SC，CAL，CT	5	3.5	4.95			1246	379.8	117

SC: washing machine

CAL: calendering

CT: corona treatment

Example 7 (comparative example)

A215 denier by 60 filament polyethylene yarn designated SPECTRA from Honeywell International Inc^*1000 yarns, having a tensile characteristic of 35g/d tenacity, a modulus of 1320g/d and an energy to break of 65J/g, were woven into a 56X 56 ends/inch (22 ends/cm) plain weave fabric. Washing the woven fabric to remove the finish and at 1.7kVA-min/m²And (4) performing lower corona treatment.

The impact target was formed from 21 squares of 18 x 18 inches (45.7 x 45.7 cm) cut from the fabric and stacked together without any connection to join in an overlap.

Example 8

Washed, calendered as described in comparative example 2 and at 1.7kVA-min/m²Corona treatment asThe same polyethylene woven fabric as described in comparative example 7. From 20% by weight of a styrene-isoprene-styrene block copolymer elastomer, KRATON is specified^*A cyclohexane solution of D1107 was applied to one surface of the fabric. After drying, the elastomer constituted 5 wt.% of the coated fabric. A linear low density polyethylene film having a thickness of 0.00035 inch (8.89 microns) was laminated to the elastomer coated fabric surface at 121 c and a rolling pressure of 635 lbs/inch (109kN/m) width. Thereby forming the laminate of the present invention.

The impact target consisted of 39 18 x 18 inch (45.7 x 45.7 cm) squares cut from the laminate and stacked together without any connection joining into an overlap.

Example 9

Washed, calendered as described in comparative example 2 and at 1.7kVA-min/m²The same polyethylene woven fabric as described in comparative example 7 was corona treated. From 20% by weight of a styrene-isoprene-styrene block copolymer elastomer, KRATON is specified^*A cyclohexane solution of D1107 was applied to one surface of the fabric. After drying, the elastomer constituted 10 wt.% of the coated fabric. A linear low density polyethylene film having a thickness of 0.00035 inch (8.89 microns) was laminated to the elastomer-coated fabric surface as described in example 8. Thereby forming the laminate of the present invention.

The impact target consisted of 37 squares of 18 x 18 inches (45.7 x 45.7 cm) cut from the laminate and stacked together without any connection to join in an overlap.

Impact test

Impact resistance of the impact targets prepared from comparative example 7 and examples 8 and 9 according to the National Institute of Justice NIJ0101.03, using a clay liner and two pellets: 9mm all metal jacketed 124 (8.0g) and 357 magnum 158 (10.2g) pellets were evaluated. The areal density of the target, the speed at which 50% of the projectile penetrated the target (V50) and the specific energy absorption of the target (SEAT) are listed in Table III below.

It can be seen that both laminates of the present invention (examples 8 and 9) prevented 50% projectile penetration at V50 speed, two and a half times greater than the unmodified fabric of comparative example 7 even at somewhat lower areal densities. The specific energy absorption of the laminate containing the low elastomer coating weight (5 wt.% for example 8) was slightly better than the laminate containing the high elastomer coating weight (10% for example 8).

TABLE III

Impact properties of the target

The components of the fabric are as follows: 215 denier SPECTRA^*1000, parts by weight; 56 x 56 ends/inch

Example No. 2	Fabric treatment	Elastomer, wt. -%)	PE film, wt. -%)	Target areal density, kg/m2	9mm FMJ		357MAG
									V50，ft/sec(m/sec)	SEATJ-m2/kg	V50，ft/sec(m/sec)	SEATJ-m2/kg
					Comparative example 7	SC，CT	0	0					5.35	＜600(＜196)	n.a.	＜600(＜196)	n.a.
8	SC，CAL，CT	5	1.70	4.97					1617(530)	198	1656(543)	262
					9	SC，CAL，CT	10	1.71					4.93	1588(521)	190	156(514)	236

SC: washing machine

CAL: calendering

CT: corona treatment

n.a.: can not obtain

Example 10 (comparative example)

1200 denier x 120 filament polyethylene yarn designated SPECTRA from Honeywell International Inc^*900 yarns, having tensile properties of 30g/d tenacity, modulus of 850g/d and energy to break of 63J/g, were woven into a 21X 21 ends/inch (8.27 ends/cm) plain weave fabric. Washing the woven fabric to remove the finish and at 1.7kVA-min/m²And (4) performing lower corona treatment. The fabric was impregnated with 20% by weight of an epoxy vinyl ester resin (Derekane 411 from Dow chemical company) modified by the removal of styrene monomer, containing 1.5% 2, 5-dimethyl-2, 5-di (2-ethylhexanoylperoxy) hexane curative. The impregnated fabric layers are stacked and bonded together by heating and curing the resin at 120 c and 500psi (3.45MPa) pressure. The initial modulus of elasticity of the neat resin in the cured state is 460,000psi (3.17 GPa). Form a solution with 4.89kg/m²The areal density of the rigid plate impacts the target.

Example 11

Washed, calendered as described in comparative example 2 and at 1.7kVA-min/m²The same woven fabric as described in comparative example 10 was corona treated.

The fabric was impregnated with 10% by weight of an epoxy vinyl ester resin (Derekane 411 from Dow Chemical Company) modified by the removal of styrene monomer, containing 1.5% 2, 5-dimethyl-2, 5-di (2-ethylhexanoylperoxy) hexane curative. The initial modulus of elasticity of the neat resin in the cured state is 460,000psi (3.17 GPa). A linear low density polyethylene film having a thickness of 0.0035 inches (88.9 microns) was laminated to the elastomer-coated fabric surface under a rolling pressure of 635 lbs/inch width (109kN/m), thereby forming the laminate of the present invention.

The laminate layers are stacked and bonded together by heating and curing the resin at 120 c and a pressure of 500psi (3.44 MPa). Thereby forming the invention with 4.89kg/m²The areal density of the rigid plate impacts the target.

Impact test

The impact resistance of the rigid plates prepared in comparative example 10 and example 11 was evaluated according to the procedure MIL-STD-662F (modified 12, 8 days 1997) using a caliber.22, type 2, 17.0 pellets (1.166g) of Fragment Simulation Pellets (FSP) conforming to MIL-P-46593A. The test specimen was mounted at a throw of 12.5 feet into the muzzle chamber of the test barrel to produce a zero degree pitch impact. The lighted screen was positioned at 5 and 10 feet, connected to a time-consuming device (timer), and used to calculate the projectile velocity at 7.5 feet from the muzzle the penetration was determined by visual inspection of a 0.020 inch (0.0508 cm) thick 2024-T3 aluminum plate positioned 2 inches behind and parallel to the test specimen.

V50 was calculated for each test sample based on the same number of highest partial penetration velocities and lowest full penetration velocities of 17.0 FSPs within 125 feet of bore.22, type 2, per second of velocity propagation. The normal up and down transmit steps are used. A minimum of four partial punctures and four complete punctures were achieved using velocities within 125 feet of velocity propagation per second. The V50 for each test specimen was calculated by taking the arithmetic mean of the same number of highest portion and lowest full puncture impact velocities over a velocity span of 125 feet per second.

The areal density of the target, V50, and the Specific Energy Absorption (SEAT) of the target are set forth in Table IV below. It can be seen that the rigid panels of the present invention have superior impact resistance compared to the control panels.

Example 12 (comparative example)

1140 denier yarn, designated KEVLAR from DuPont^*49 aramid (poly (phenylene terphthalamide)) having tensile properties of 28g/d tenacity, a modulus of 976g/d and an energy to break of 24J/g, was woven into a 17 x 17 ends/inch (6.7 ends/cm) plain weave fabric. The fabric was impregnated with 10% by weight of an epoxy vinyl ester resin (Derekane 411 from Dow Chemical Company) modified by the removal of styrene monomer, containing 1.5% 2, 5-dimethyl-2, 5-di (2-ethylhexanoylperoxy) hexane curative. The impregnated fabric layers are stacked and bonded together by heating and curing the resin at 120 c and 500psi (3.45MPa) pressure. The initial modulus of elasticity of the neat resin in the cured state is 460,000psi (3.17 GPa). Form a solution with 4.89kg/m²The areal density of the rigid plate impacts the target.

TABLE IV

Impact properties of the target

The components of the fabric are as follows: 1200 denier SPECTRA^*900; 21 x 21 ends/inch

Example No. 2	Fabric treatment	A resin matrix, wt. -%)	PE film, wt. -%)	Target areal density, kg/m2	V50		SEAT，J-m2/kg
								ft/sec	m/sec
					Comparative example 10	SC，CT				20	0	4.89	1550	472	24.3
11	SC，CAL，CT	10	1.67	4.89			1656	505	28.5

SC: washing machine

CAL: calendering

CT: corona treatment

Example 13

Washing and calendering as described in comparative example 2 the same KEVLAR as described in comparative example 12^*49 of fabric. The fabric was impregnated with 10% by weight of a modified epoxy vinyl ester resin (Derekane 411 from Dow Chemical Company) modified by the removal of styrene monomer, containing 1.5% 2, 5-dimethyl-2, 5-di (2-ethylhexanoylperoxy) hexane curative. The initial modulus of elasticity of the neat resin in the cured state is 460,000psi (3.17 GPa). A linear low density polyethylene film having a thickness of 0.0035 inches (88.9 microns) was laminated to the surface of the elastomer-coated fabric under a rolling pressure of 635 lbs/inch width (109kN/m), thereby forming the laminate of the present invention.

The laminate layers are stacked and bonded together by heating and curing the resin at 120 c and a pressure of 500psi (3.45 MPa). Thereby forming a catalyst having a molecular weight of 4.89kg/m²The areal density of the rigid plate impacts the target.

Example 14 (comparative example)

1090 dtex yarn, assigned ZYLON from Toyobo, grade HM^*PBO fibers (poly (p-phenylene-2, 6-benzobisoxazole)) having a tensile rating of 42g/d tenacity, a modulus of 1900g/d and an energy to break of 26J/g were woven into a 17X 17 ends/inch (6.7 ends/cm) plain weave fabric. The fabric was impregnated with 20% by weight of an epoxy vinyl ester resin (Derekane 411 from Dow chemical company) modified by the removal of styrene monomer, containing 1.5% 2, 5-dimethyl-2, 5-di (2-ethylhexanoylperoxy) hexane curative. The impregnated fabric layers are stacked and bonded together by heating and curing the resin at 120 c and 500psi (3.45MPa) pressure. The initial modulus of elasticity of the neat resin in the cured state is 460,000psi (3.17 GPa). Form a solution with 4.89kg/m²Rigid plate punch with surface densityAnd (6) hitting the target.

Example 15

As described in comparative example 2, the same ZYLON as described in comparative example 14 was washed^*PBO fibers. The fabric was impregnated with 10% by weight of a modified epoxy vinyl ester resin (Derekane 411 from Dow Chemical Company) modified by the removal of styrene monomer, containing 1.5% 2, 5-dimethyl-2, 5-di (2-ethylhexanoylperoxy) hexane curative. The initial modulus of elasticity of the neat resin in the cured state is 460,000psi (3.17 GPa). A linear low density polyethylene film having a thickness of 0.0035 inches (88.9 microns) was laminated to the surface of the elastomer-coated fabric under a rolling pressure of 635 lbs/inch width (109kN/m), thereby forming the laminate of the present invention.

The laminate layers are stacked and bonded together by heating and curing the resin at 120 c and a pressure of 500psi (3.44 MPa). Thereby forming the invention with 4.89kg/m²The areal density of the rigid plate impacts the target.

Impact test

The impact resistance of the rigid plates prepared in comparative examples 12 and 14 and inventive examples 13 and 15 was evaluated according to the procedure MIL-STD-662F (modified at 12.8 days 1997) using a caliber.22, type 2, 17.0 pellets (1.166g) of Fragment Simulation Pellets (FSP) conforming to MIL-P-46593A. The test specimen was mounted at a throw of 12.5 feet into the muzzle chamber of the test barrel to produce a zero degree pitch impact. The lighted screen, positioned at 5 and 10 feet, was connected to a time-consuming device (timer) and was used to calculate the projectile velocity at 7.5 feet from the muzzle. The puncture was determined by visual inspection of a 0.020 inch (0.0508 cm) thick 2024-T3 aluminum plate positioned 2 inches behind and parallel to the test specimen. It is desirable that the rigid panels of the present invention have superior impact resistance compared to their respective control panels.

Having thus described the invention in rather full detail, it is to be understood that such detail is not necessarily in the strict sense, which would enable one skilled in the art to make further changes and modifications, all of which are within the scope of the invention as defined by the appended claims.

Claims (27)

1. An impact resistant laminate comprising:

a. a woven fabric comprising at least 50% by weight high strength yarns having a tenacity equal to or greater than about 7g/D, an initial tensile modulus equal to or greater than about 150g/D, and an energy to break measured by ASTM D2256 equal to or greater than about 8J/g;

b. an elastomer coated on at least a portion of one side of said woven fabric, said elastomer having an initial tensile modulus of equal to or less than about 6,000psi (41.4MPa) as measured by ASTM D638; and

c. a plastic film bonded to at least a portion of said elastomer-coated surface.

2. The laminate of claim 1 wherein said woven fabric is a laundered and corona treated woven fabric.

3. The laminate of claim 1 wherein said woven fabric is a laundered, corona treated and calendered woven fabric.

4. The laminate of claim 1 wherein said high tenacity yarns have a tenacity equal to or greater than about 15g/D, an initial tensile modulus equal to or greater than about 400g/D and an energy to break measured by ASTM D2256 of equal to or greater than about 15J/g.

5. The laminate of claim 1 wherein said high tenacity yarns have a tenacity equal to or greater than about 30g/D, an initial tensile modulus equal to or greater than about 1000g/D and an energy to break measured by ASTM D2256 of equal to or greater than about 27J/g.

6. The laminate of claim 1 wherein at least one of said high tenacity yarns is a polyethylene yarn.

7. The laminate of claim 1 wherein at least one of said high tenacity yarns is a poly (p-phenylene terephtalamide) yarn.

8. The laminate of claim 1 wherein at least one of said high tenacity yarns is a polybenzazole yarn selected from the group consisting of: polybenzoxazole (PBO) yarns and Polybenzothiazole (PBT) yarns.

9. The laminate of claim 1 wherein said elastomer has an initial tensile modulus as measured by ASTM D638 of equal to or less than about 2400psi (16.5 MPa).

10. The laminate of claim 1 wherein said elastomer has an initial tensile modulus as measured by ASTM D638 of equal to or less than about 1200psi (8.23 MPa).

11. The laminate of claim 1 wherein said elastomer comprises from about 0.5 to about 15 weight percent of the laminate.

12. The laminate of claim 1 wherein said elastomer comprises from about 1 to about 10 weight percent of the laminate.

13. The laminate of claim 1 wherein said elastomer comprises from about 2 to about 8 weight percent of the laminate.

14. The laminate of claim 1 wherein said plastic film comprises from about 0.5 to about 5 weight percent of the laminate.

15. The laminate of claim 1 wherein said plastic film is comprised of a member selected from the group consisting of: polyolefins, polyamides, polyesters and polyfluorocarbons.

16. The laminate of claim 1 wherein said plastic film consists of polyethylene.

17. An impact resistant laminate comprising:

a) a laundered and corona treated woven fabric comprising at least 50% by weight high strength yarns having a tenacity equal to or greater than about 22g/D, an initial tensile modulus equal to or greater than about 400g/D and an energy to break equal to or greater than about 22J/g as measured by ASTM D2256;

b) an elastomer coated on at least a portion of one side of said woven fabric, said elastomer having an initial tensile modulus as measured by ASTM D638 of less than about 1200psi (8.23MPa), said elastomer comprising from about 1 to about 10 weight percent of the laminate; and

c) a plastic film bonded to said elastomer-coated surface, said plastic film comprising from about 0.5 to about 5 weight percent of a laminate.

18. An impact resistant laminate comprising:

a) a laundered and corona treated woven fabric comprising at least 50% by weight high tenacity polyethylene yarns, the yarns having a tenacity equal to or greater than about 22g/d, an initial tensile modulus equal to or greater than about 400g/d and an energy to break measured by astm d2256 equal to or greater than about 22J/g;

b) an elastomer coated on at least a portion of one side of said woven fabric, said elastomer comprising a block copolymer of a conjugated diene and a vinyl aromatic copolymer having an initial tensile modulus measured by ASTM D638 of less than about 1200psi (8.23GPa), said elastomer comprising from about 1 to about 10 weight percent of the laminate; and

c) a polyethylene film bonded to said elastomer-coated surface, said polyethylene film comprising from about 0.5 to about 5 weight percent of the laminate.

19. The laminate of claim 17 or 18 wherein said woven fabric is a laundered, corona treated and calendered woven fabric.

20. An impact resistant laminate comprising:

a. a laundered and corona treated woven fabric comprising at least a major portion of yarns having a tenacity equal to or greater than about 7g/D, an initial tensile modulus of at least about 150g/D and an energy to break as measured by ASTM D2256 of at least about 8J/g; impregnation was performed with the following;

b. a matrix resin having an initial tensile modulus, when cured, equal to or greater than about 300,000psi (2.07GPa) as measured by ASTM D638; and

c. a plastic film bonded to at least a portion of at least one side of said fabric.

21. The laminate of claim 20 wherein said woven fabric is a washed, calendered and corona treated woven fabric.

22. The laminate of claim 20 wherein said matrix resin comprises from about 5 to about 15 weight percent of the laminate.

23. An impact resistant rigid panel wherein at least one component is comprised of a plurality of laminates bonded in a stacked arrangement according to either claim 1 or claim 20.

24. The impact resistant rigid panel of claim 23 further comprising at least one hard-facing component selected from the group consisting of: metal, ceramic, glass, metal-filled composite, ceramic-filled composite or glass-filled composite.

25. A method of producing an impact resistant laminate comprising the steps of:

a) forming a woven fabric comprising at least a majority of yarns having a tenacity equal to or greater than about 7g/D, an initial tensile modulus of at least about 150g/D, an energy to break as measured by ASTM D2256 of at least about 8J/g;

b) coating at least a portion of one side of said fabric with an elastomer having an initial tensile modulus of less than about 6,000psi (41.4MPa) as measured by ASTM D638; and

c) adhering a plastic film to said elastomer-coated surface.

26. A method of producing an impact resistant laminate comprising the steps of:

a) forming a woven fabric comprising at least a majority of yarns having a tenacity equal to or greater than about 7g/d, an initial tensile modulus of at least about 150g/d, an energy to break of at least about 8J/g;

b) washing and corona treating said woven fabric;

c) impregnating said fabric with a resin having a tensile modulus equal to or greater than 300,000psi (2.07GPa) when cured; and

d) a plastic film is bonded to at least a portion of one surface of said fabric.

27. The process of either claim 25 or claim 26, further comprising the step of calendering said woven fabric.