KR101485309B1 - Multilayered material sheet and process for its preparation - Google Patents

Abstract

The present invention relates to a multilayer material sheet comprising a consolidated laminate consisting of a unidirectional monolayer of stretched ultra high molecular weight polyolefin. The stretching directions of the two continuous single layers in the laminate are different. The multi-layered sheet also includes at least one monolayer having a thickness of 50 mu m or less, and at least one monolayer having a strength of 1.2 to 3 GPa. The present invention also relates to a ballistic article comprising said multilayer sheet and a method of making said article.

Description

[0001] MULTILAYERED MATERIAL SHEET AND PROCESS FOR ITS PREPARATION [0002]

The present invention relates to a multilayer material sheet comprising a consolidated laminate consisting of a unidirectional monolayer of stretched ultrahigh molecular weight polyolefin and a method of making the same. The present invention is also directed to a ballistic article comprising said multilayer sheet.

A multilayer material sheet comprising a consolidated laminate consisting of a unidirectional monolayer of stretched ultra high molecular weight polyethylene is known from EP 162 77 19 A1. This publication discloses a multilayer material sheet comprising a plurality of unidirectional monolayers essentially consisting of ultra high molecular weight polyethylene and essentially free of bonding matrices, wherein the two continuous monolayers in the laminate have different stretching directions. In the case of a single layer of the multi-layer sheet, the posted thickness is 30 to 120 mu m, preferably 50 to 100 mu m.

The multilayer sheet according to EP 1627719 A1 uses ultra high molecular weight polyethylene which is essentially free of bonding matrix. This feature is necessary to obtain desirable bulletproof characteristics. Although the multilayered sheet according to EP 1627719 A1 shows satisfactory bulletproof performance, such performance can be further improved.

It is an object of the present invention to provide a multilayer sheet having improved bulletproof properties compared to known materials.

The object is achieved by a laminate comprising a consolidated laminate consisting of a unidirectional monolayer of a drawn ultra-high molecular weight polyolefin, wherein the two continuous monolayers in the laminate are different in the stretching direction and have a thickness of not more than 50 탆, Layer material sheet comprising at least one monolayer having a strength of at least 1.2, 2.5 or 3.0 GPa. Preferably, it comprises at least one monolayer having a strength of 1.2 to 3 GPa, more preferably 1.5 to 2.6 GPa, most preferably 1.8 to 2.4 GPa. Surprisingly, it has been found that due to the particular combination of these features, improved bulletproof properties are obtained compared to known multilayer sheet materials. More specifically, when the ballistic performance of the multi-layer material sheet according to European Patent No. 1627719 A1 is 100%, a ballistic performance of 130% or more is obtained by the multi-layer material sheet according to the present invention. A further advantage of the material sheet according to the invention is that it is no longer necessary to use ultrahigh molecular weight polyethylene which is essentially free of the associative matrix in order to obtain the desired level of anti-ballistic properties.

A preferred multilayer material sheet according to the present invention comprises at least one monolayer having a thickness of 25 [mu] m or 29 [mu] m or less, wherein the monolayer strength is 1.2, 2.5 or 3.0 GPa or more, preferably 1.2 to 3 GPa, 1.5 to 2.6 GPa, and most preferably 1.8 to 2.4 GPa. A further preferred material sheet according to the present invention comprises at least one monolayer having a thickness of from 3 to 29 microns, more preferably from 3 to 25 microns, wherein the monolayer strength is 1.2, 2.5 or 3.0 GPa or more, preferably 1.2 To 3 GPa, more preferably from 1.5 to 2.6 GPa, and most preferably from 1.8 to 2.4 GPa. Another preferred material sheet according to the present invention comprises at least one monolayer having a thickness of 5 mu m, preferably 7 mu m, more preferably more than 10 mu m and not more than 50 mu m, 3.0 GPa or more. More preferably, the monolayer strength is 1.2 to 3 GPa, even more preferably 1.5 to 2.6 GPa, and most preferably 1.8 to 2.4 GPa.

In the present invention, not all monolayers need to have the thickness and strength of the claimed range, but a multilayer material sheet in which all monolayers have a thickness and strength in the claimed range is particularly preferred.

The unidirectional monolayer can be made of an oriented tape or film. Unidirectional tapes and monolayers as used herein mean tapes and monolayers in which the preferred orientation of the polymer chains in one direction, that is, in the direction of stretching. Such tapes and monolayers may be prepared by stretching, preferably uniaxial stretching, and exhibit anisotropic mechanical properties.

The multi-layered sheet of the present invention preferably comprises ultra high molecular weight polyethylene. The ultrahigh molecular weight polyethylene may be linear or branched, but preferably linear polyethylene is used. Linear polyethylene herein is understood to mean polyethylene having less than 1 side chain per 100 carbon atoms, preferably less than 1 side chain per 300 carbon atoms (side chain or branch generally containing 10 or more carbon atoms ). The side chains can be suitably measured by FTIR on a 2 mm thick, compression molded film, as described, for example, in EP 0269151. [ The linear polyethylene may additionally contain not more than 5 mole% of one or more other alkenes which can be incorporated together, for example, propene, butene, pentene, 4-methylpentene, octene. Preferably, said linear polyethylene has an intrinsic viscosity (IV, measured in solution in decalin at 135 DEG C) of at least 4 dl / g, more preferably at least 8 dl / g and most preferably at least 10 dl / g High-mass. Such polyethylenes are also referred to as ultra high molecular weight polyethylene (UHMWPE). The intrinsic viscosity is a measure of the molecular weight that can be measured more easily than the actual molar mass parameters such as Mn and Mw. This type of polyethylene film is particularly excellent in anti-ballistic properties.

The tape according to the present invention can be produced in the form of a film. A preferred method for forming such a film or tape is to supply the polymeric powder between a combination of endless belts, press-mold the polymeric powder at a temperature below the melting point of the polymeric powder, Rolling the molded polymer, and then stretching. Such a method is described, for example, in European Patent No. 0733460 A2, which is incorporated herein by reference. If desired, the polymer powder may be mixed with a suitable liquid organic compound having a boiling point above its melting point before feeding and compression-molding the polymer powder. Compression-molding may also be performed by temporarily holding the polymer powder between the endless belts during transfer. This can be done, for example, by providing a pressing platen and / or a compression roller connected to the endless belt. Preferably, UHMWPE is used in this method. This UHMWPE needs to be extensible in the solid state.

Another preferred method for forming a film comprises feeding the polymer to an extruder, extruding the film at a temperature above the melting point of the film, and stretching the extruded polymer film. If desired, the polymer may be mixed with an appropriate liquid organic compound to form, for example, a gel, prior to feeding the polymer to the extruder, which is preferred when ultra high molecular weight polyethylene is used.

The polyethylene film is preferably produced by the above gel method. Suitable gel spinning processes are described, for example, in GB-A-2042414, GB-A-2051667, EP-A-0205960 A and WO 01/73173 A1, and Advanced Fiber Spinning Technology "Ed. T. Nakajima, Woodhead Publ. Ltd (1994), ISBN 185573 1827). In short, the gel spinning process comprises preparing a polyolefin solution of high intrinsic viscosity, extruding the solution at a temperature above its dissolution temperature, cooling the film below its gelation temperature to at least partially gellify the film, And stretching the film before, during, and / or after at least partial removal of the solvent.

The stretching, preferably uniaxial stretching, of the produced film can be carried out by means known in the art. This means includes extrusion elongation and tensile elongation on suitable elongation units. To obtain increased mechanical strength and stiffness, the stretching can be performed in multiple steps. In the case of a preferred ultra high molecular weight polyethylene film, uniaxial stretching is typically carried out with a number of stretching steps. The first stretching step may include, for example, stretching with an extension factor of three. Multiple stretches typically result in an elongation factor of 9 in the case of a draw temperature below 120 DEG C, an elongation factor of 25 in the case of a draw temperature below 140 DEG C and 50 in the case of a draw temperature of 150 DEG C and above . By multiple stretching with increasing temperature, an elongation factor of about 50 or more can be reached. As a result, a high-strength tape is obtained, whereby in the case of ultrahigh molecular weight polyethylene, a claimed strength range of 1.2 to 3 GPa or more can be easily obtained.

Using the obtained stretched tape as it is, a single layer can be produced, cut to a desired width, or split according to the stretching direction. The width of the unidirectional tape thus produced is limited only by the width of the film used in the production of the tape. The width of the tape is preferably greater than 2 mm, more preferably greater than 5 mm, and most preferably greater than 30, 50, 75, or 100 mm. The area density of the tape or monolayer can vary widely and is, for example, 3 to 200 g / m 2. The preferred areal density is 5 to 120 g / m 2, more preferably 10 to 80 g / m 2, and most preferably 15 to 60 g / m 2. In the case of UHMWPE, the areal density is preferably less than 50 g / m 2, more preferably less than 29 or 25 g / m 2.

A preferred multilayer sheet according to the present invention is characterized in that it comprises at least one monolayer including a plurality of unidirectional tapes of oriented polyolefin aligned in the same direction but not overlapping with adjacent tapes. This provides a multilayer sheet having a structure much simpler than the structure disclosed in EP 1627719 A1. Indeed, the multilayer material disclosed in EP 162 7719 A1 is produced by placing a plurality of tapes of ultrahigh molecular weight polyethylene adjacent to each other, wherein the tapes overlap over some contact area of their longitudinal edges. Preferably, the area is further covered by a polymeric film. The multi-layer material of the preferred embodiment of the present invention does not require such a complicated structure for excellent bulletproof performance.

In some embodiments, the monolayer may be applied locally to include a binder that bonds and stabilizes the plurality of unidirectional tapes so that the structure of the monolayer is maintained during handling and manufacturing of the unidirectional sheet. Suitable binders are described, for example, in EP 0191306 B1, EP 1170925 A1, EP 0683374 B1 and EP 1144740 A1. Applying the binder during monolayer formation advantageously stabilizes the tape, and therefore a faster production cycle can be achieved.

Another particularly preferred multilayer material sheet according to the present invention comprises at least one, preferably all, monolayers of a plurality of unidirectional tapes of oriented polymer aligned to form a woven structure. Such tapes may be produced by applying textile techniques, such as weaving, braiding, etc., to a small strip of ultra-high molecular weight polyolefin and ultrahigh molecular weight polyethylene in particular. The strip has the same thickness and strength values as those required in the present invention.

The multi-layer material sheet according to the present invention preferably comprises at least two uni-directional monolayer, more preferably at least four uni-directional monolayer, even more preferably at least six uni-directional monolayer, even more preferably at least eight uni-directional monolayer , And most preferably at least 10 unidirectional monolayers. Increasing the number of unidirectional monolayers in the multilayered sheet of the present invention simplifies the manufacture of articles for forming the material sheet, e.g., a bulletproof plate.

The present invention also relates to a method of making a multilayer sheet of the claimed form. The process according to the invention comprises the following steps:

(a) providing a stretched plurality of ultra-high molecular weight polyethylene tapes according to the invention, wherein each tape is aligned to be oriented parallel to the adjacent tape so that adjacent tapes can be partially overlapped;

(b) placing the plurality of stretched ultrahigh molecular weight polyethylene tapes on a substrate to form a first monolayer;

(c) placing a plurality of stretched ultrahigh molecular weight polyethylene tapes according to the present invention on the first monolayer to form a second monolayer having an angle? relative to the first monolayer; And

(d) squeezing the formed laminate under high temperature to consolidate its monolayers.

Compression of the unidirectional monolayers means that they are sufficiently interconnected with each other that the unidirectional monolayers are not desorbed under normal use conditions such as room temperature, for example. According to the method of the present invention, a multilayer material sheet having a single layer of required thickness and strength can be easily manufactured.

The multi-layer material sheet according to the invention is particularly useful for manufacturing armor products, for example vests or protective plates. Ballistic products include products with ballistic threats to various types of trajectories, including trajectories for protective piercings, so-called APs, ballistic improved explosive devices, and hard particles, such as debris and grenades.

The bulletproof article according to the present invention preferably comprises at least two unidirectional monolayers, preferably at least 10 unidirectional monolayers, more preferably at least 20 unidirectional monolayers, even more preferably at least 30 or at least 40 unidirectional monolayers, Lt; RTI ID = 0.0 > 80 < / RTI > The stretching direction of the two continuous monolayers in the laminate is different by angle?. The angle α is preferably 45 to 135 °, more preferably 65 to 115 °, and most preferably 80 to 100 °.

The bulletproof article according to the present invention is preferably a ceramic, a metal, preferably steel, aluminum, magnesium, titanium, nickel, chromium, iron and alloys thereof; An additional sheet of inorganic material selected from the group consisting of glass, graphite, and combinations thereof. A metal is particularly preferred. In this case, the metal in the metal sheet preferably has a melting point of 350 DEG C or higher, more preferably 500 DEG C or higher, and most preferably 600 DEG C or higher. Examples of suitable metals include alloys of aluminum, magnesium, titanium, copper, nickel, chromium, beryllium, iron, copper and their alloys such as steel and stainless steel and aluminum and magnesium And alloys of magnesium or zinc, magnesium and copper (so-called aluminum 7000 series). In the alloy, for example, the amount of aluminum, magnesium, titanium and iron is preferably 50% by weight or more. Preferred metal sheets include aluminum, magnesium, titanium, nickel, chromium, beryllium, iron and their alloys. More preferred metal sheets are based on aluminum, magnesium, titanium, nickel, chromium, iron and alloys thereof. As a result, a lightweight, bulletproof product having excellent durability is obtained. Even more preferably, the iron in the metal sheet and the alloy thereof have a Brinell hardness of 500 or more. The most preferred metal sheets are based on aluminum, magnesium, titanium and alloys thereof. This results in a lightest bulletproof product having the highest durability. Durability herein means the life of the composite under conditions of exposure to heat, moisture, light and ultraviolet (UV) radiation. The additional sheet of material may be located anywhere within the laminate of the monolayer, but the preferred armor article is characterized in that the additional sheet of material is located on the outside of the laminate of the monolayer, most preferably at least at the impingement side thereof.

The armor-proof product according to the present invention preferably comprises an additional sheet of the above-mentioned inorganic material having a thickness of 100 mm or less. The maximum thickness of the additional sheet of inorganic material is preferably 75 mm, more preferably 50 mm, and most preferably 25 mm. This results in the best balance between weight and saturation characteristics. Preferably, when the additional sheet of inorganic material is a metal sheet, the thickness of the additional sheet, preferably the metal sheet, is at least 0.25 mm, more preferably at least 0.5 mm, and most preferably at least 0.75 mm. This results in much better ballistic performance.

Optionally, additional sheets of inorganic material may be pre-treated to improve adhesion to the multilayer sheet. Suitable pre-treatments of the additional sheet include mechanical treatment, such as sanding or grinding, e.g. chemical etching with nitric acid and roughening or cleaning of the sheet surface by laminating with a polyethylene film.

In another embodiment of the armor article, a bonding layer, such as an adhesive, may be applied between the additional sheet and the multi-layered sheet. The adhesive may include an epoxy resin, a polyester resin, a polyurethane resin, or a vinyl ester resin. The bonding layer preferably comprises less than 30% by weight, more preferably less than 20% by weight, even more preferably less than 10% by weight, most preferably less than 5% by weight of the anti-tarnish product.

In another preferred embodiment, the bonding layer may further comprise a woven or non-woven layer of inorganic fibers, for example glass fibers or carbon fibers. It is also possible to attach the additional sheet to the multilayer sheet by mechanical means such as screws, bolts and snap fit. When a bulletproof article according to the present invention is used for ballistic purposes which may be confronted with the AP bullet threat, said additional sheet preferably comprises a metal sheet covered with a ceramic layer. Thereby, a bulletproof article having the following laminated structure is obtained: ceramic layer / metal sheet / two or more unidirectional sheets, wherein the direction of the fibers in the unidirectional sheet is in the direction of the fibers in the adjacent unidirectional sheet Lt; / RTI > Suitable ceramic materials include, for example, alumina oxide, titanium oxide, silicon oxide, silicon carbide, and boron carbide. The thickness of the ceramic layer varies depending on the trajectory threat level, but generally varies between 2 mm and 30 mm. Such armor articles are preferably positioned such that the ceramic layer faces the ballistic threat. This provides the best protection against AP bullets and hard debris.

The present invention also relates to a method of making a bulletproof article comprising the steps of:

(a) laminating one or more multi-layer material sheets according to the present invention and an additional sheet of inorganic material selected from the group consisting of ceramic, steel, aluminum, titanium, glass, graphite and combinations thereof;

(b) consolidating the laminated sheet under high temperature and high pressure.

A preferred method of making a bulletproof product comprises the following steps:

(a) laminating at least one multi-layered sheet comprising a consolidated laminate of unidirectional monolayers of a drawn ultra-high molecular weight polyolefin, wherein the two continuous monolayers in the laminate are different in elongation direction and 50 (Or more preferably from 1.2 to 3 GPa) of a monolayer having a thickness of at most 1.2 m, preferably at most 0.2 m, more preferably at most 29 m, even more preferably at most 25 m, Wherein the additional sheet of material is selected from the group consisting of ceramic, steel, aluminum, titanium, glass, graphite, and combinations thereof; And

(b) consolidating the laminated sheet under high temperature and high pressure.

In both of the above-described methods, consolidation can be performed properly in a hydraulic press. Consistency means that the monolayers are relatively strongly adhered to each other to form a unit. The temperature at solidification is generally controlled through the temperature of the press. The minimum temperature is generally chosen such that a reasonable cementing rate is obtained. In this regard, a suitable lower temperature limit is 80 占 폚, preferably 100 占 폚 or higher, more preferably 120 占 폚 or higher, and most preferably 140 占 폚 or higher. The maximum temperature is selected to be below the temperature at which the stretched polymer monolayers lose their high mechanical properties, for example due to melting. Preferably, the temperature is lower than the melting temperature of the stretched polymer monolayer, preferably at least 10 占 폚, more preferably at least 15 占 폚, and even more preferably at least 20 占 폚. If the stretched polymer monolayer does not exhibit a certain melt temperature, the temperature at which the stretched polymer monolayer starts to lose its mechanical properties should be read instead of the melt temperature. In the case of the preferred ultra-high molecular weight polyethylene, a temperature of less than 149 DEG C, preferably less than 145 DEG C, will generally be selected. The pressure at the solidification is preferably at least 7 MPa, more preferably at least 15 MPa, even more preferably at least 20 MPa, and most preferably at least 35 MPa. Thereby, a rigid bulletproof product is obtained. The optimum curing time is generally from 5 to 120 minutes, depending on conditions such as temperature, pressure and part thickness, which can be ascertained through routine experimentation. If it is desired to produce curved armor articles, it may be advantageous to first preform the said additional sheet of material in its preferred form and then consolidate with said single layer and / or multi-layer material sheet.

Preferably, to obtain a high degree of bulletproofing, cooling after compression-molding at high temperatures is also carried out under pressure. The pressure is preferably maintained at least until the temperature is low enough to prevent relaxation. The temperature can be set by a person skilled in the art. When making armored products comprising monolayers of ultrahigh molecular weight polyethylene, typical compression temperatures are from 90 to 150 캜, preferably from 115 to 130 캜. Typical press pressures are from 100 to 400 bar, more preferably from 110 to 350 bar, even more preferably from 110 to 250 bar, most preferably from 120 to 160 bar, and the pressing time is typically 20 minutes, Is from 40 to 180 minutes.

The multilayer sheet and armor articles of the present invention are advantageous over bulletproof materials previously known to provide improved levels of protection, particularly as lightweight, known products. As well as properties such as thermal stability, shelf life, deformation resistance, ability to bond with other material sheets, and workability.

The experimental method referred to herein (unless otherwise stated) is as follows.

- Intrinsic viscosity (IV): It is determined according to the method of PTC-179 (Hercules Inc. Rev. Apr. 29, 1982) in decalin at 135 ° C, dissolution time is 16 hours, antioxidant is 2 g / l A solution of DBPC is used, and the viscosity at different concentrations is determined by extrapolation to zero concentration.

Tensile strength (or strength), tensile modulus (or modulus) and elongation at break (or eab) are the nominal gauge length of a 500 mm fiber, crosshead speed at 50% / min Filament yarn as specified in ASTM D885M. Based on the measured stress-strain curve, the modulus is determined by a gradient between 0.3 and 1% stress. To calculate the modulus and strength, the measured tensile force is divided by the titre determined by weighing 10 m of fiber, and the GPa value is calculated assuming a density of 0.97 g / cm < 3 >. The tensile properties of the thin film were measured according to ISO 1184 (H).

The invention is now further illustrated by the following examples and comparative experiments, but is not limited thereto.

[ Example ]

Example  - Tape manufacturing

The ultra high molecular weight polyethylene having an intrinsic viscosity of 20 was mixed with decalin to obtain a 7 wt% suspension. The suspension was fed to an extruder and mixed at a temperature of 170 캜 to prepare a homogeneous gel. The gel was then fed through a slot die having a width of 600 mm and a thickness of 800 [mu] m. After extrusion through a slot die, the gel was quenched in a water bath to form a gel-tape. The gel tape was stretched to a factor of 3.8 and then dried in an oven consisting of two parts at 50 캜 and 80 캜 until the amount of decalin was less than 1%. This dry gel tape was then stretched in an oven at 140 DEG C at a draw ratio of 5.8 and then subjected to a second stretching step at an oven temperature of 150 DEG C to obtain a final thickness of 18 mu m.

Of tape Performance test

The tensile properties of the tape were tested by twisting the tape at a frequency of 38 twist / m to form a narrow structure to be tested in the case of ordinary yarns. Additional testing was performed according to ASTM D885M using a nominal gauge length of 500 mm fiber, a crosshead speed of 50% / min and an Instron 2714 clamp of the Fiber Grip D5618C type.

Example : Protective panel from tape ( armor panel )

The first layer of tape was placed and parallel tapes were placed adjacent to each other. The second layer of the adjacent parallel tape was placed on the first layer while the tape direction of the second layer was made perpendicular to the tape direction of the first layer. The third layer was then placed over the second layer, but was again perpendicular to the second layer. The third layer was positioned slightly shifted (about 5 mm) relative to the first layer. This movement is applied to minimize the possibility of stacking the tape edges at a particular point. The fourth layer was positioned to be orthogonal to the third layer, but slightly shifted relative to the second layer. This process was repeated until an areal density (AD) of 2.57 kg / m < 2 > was reached. The laminate of laminated tapes was transferred into a press and compressed at a temperature of 145 캜 and a pressure of 300 bar for 65 minutes. Cooling was carried out under pressure until a temperature of 80 < 0 > C was reached. The binder was not applied to the tape. Nevertheless, the laminate was fused to a homogeneous 800 x 400 mm plate of rigidity.

Of the protective panel Performance test

Shooting tests on guard plates were performed with a 9 mm parabolic bullet. The test was conducted for the purpose of measuring V50 and / or absorbed energy (E-abs). V50 is the speed at which 50% of the projectile penetrates through the protection plate. The experimental procedure is as follows. The first projectile was fired at the predicted speed V50. Actual speed was measured just before impact. When the projectile was stopped, the next projectile was foamed at an intended rate of about 10% higher. If penetrated, the next projectile was foamed at an intended rate of about 10% lower. The actual impact velocity was always measured. V50 averaged the two highest stopping speeds and the lowest two throughputs. The performance of the protective plate was also determined by calculating the kinetic energy of the projectile at V50 and dividing it by the AD of the plate (E-abs).

Results :

Comparative Example A was performed on sheets formed from commercially available ultra high molecular weight polyethylene (UHMWPE) unidirectional fibers. The fibers were immersed in 20 wt% thermoplastic polymer and bound together. The strength of the monolayers in Comparative Example A was 2.8 GPa, which is the strength of the fiber drain relative to the fiber content in the monolayer. The monolayers of the comparative examples were pressed at about 125 캜 under a pressure of 165 bar for 65 minutes to produce sheets having the required areal density. The thickness of the single layers after pressing was 65 μm.

According to the above results, a multilayered material sheet having a single layer strength of 50 탆 or less and a single layer strength of 1.2 GPa or more exhibits an unexpectedly improved ballistic performance as compared with a protective sheet made of a conventional UD fiber-based multilayer sheet. In particular, the multi-layer material sheet of the present invention exhibits significantly higher E-abs values than comparative samples of the prior art.

Claims (15)

A multi-layer material sheet comprising a consolidated laminate consisting of a unidirectional monolayer of stretched ultra high molecular weight polyolefin,
Wherein two successive single layers in the laminate have different stretching directions;
Wherein the material sheet comprises at least one monolayer having a thickness of not more than 50 mu m and at least one monolayer having a strength of not less than 1.2 GPa;
Wherein the single layer is a gel having a surface area density of at least 2 mm wide and 3 to 200 g / m ² - spun containing (gel-spun) the polyolefin tape,
Multilayer sheet. The method according to claim 1,
And at least one monolayer having a strength of 1.2 to 3 GPa. The method according to claim 1,
3 to 200 g / m include one or more of the single layer has a area density of ^2, and containing one or more of the drawn ultra-high-molecular-weight polyolefin tape having an areal density of 10 to 80 g / m ^2, the multi-layer sheet material. The method of claim 3,
Wherein the tape has an areal density of 15 to 60 g / m < ² >. The method according to claim 1,
And at least one monolayer having a thickness of 29 占 퐉 or less. The method according to claim 1,
And at least one unidirectional monolayer having an areal density of 5 to 120 g / m < ² >. The method according to claim 1,
Wherein the polyolefin is ultra high molecular weight polyethylene and the area density of the tape is less than 50 g / m < 2 >. The method according to claim 1,
Wherein the stretching direction of the two continuous monolayers in the laminate is different by an angle? Of 45 to 135 占. delete The method according to claim 1,
A multi-layer material sheet comprising at least one monolayer comprising a plurality of unidirectional tapes of oriented polyolefin, aligned to form a fabric. A protective article comprising a multilayer sheet according to any one of claims 1 to 8 and 10. 12. The method of claim 11,
A bulletproof article comprising ten or more unidirectional monolayers. 12. The method of claim 11,
Wherein the article further comprises a sheet of one or more materials selected from the group consisting of ceramics, metals, alloys and graphite. 14. The method of claim 13,
Armor products with an additional sheet thickness of 50 mm or less. 14. The method of claim 13,
Further comprising a bonding layer between the additional sheet and the multi-layer material sheet, wherein the bonding layer comprises a woven or nonwoven layer of inorganic fibers.