KR20010089661A - Hybrid Protective Composite - Google Patents

Abstract

The present invention provides a plurality of woven polybenzoxazole or polybenzothiazole fiber layers 12, a plurality of impact resistant layers 16, and a plurality of densely woven anti-penetration layers 14 that prevent knife and ice awl puncture penetration. It relates to a composite prepared from. The layers may comprise para-aramid fibers or polyethylene fibers.

Description

Hybrid Protective Composites

International Patent Publication No. 93/20400, published October 14, 1993, discloses the use of polybenzoxazole and polybenzothiazole fibers in impact resistant articles.

US Patent No. 5,578,358 to Foy et al., Issued November 26, 1996, discloses an anti-penetration structure made from woven aramid yarns, particularly of low linear density.

International Patent Publication No. 93/00564, published on January 7, 1993, discloses an impact structure using a fabric layer woven from high stiffness para-aramidyan.

U.S. Patent 5,472,769, issued Dec. 5, 1995, describes a combination of a knitted aramid yarn layer and a deflection layer of material, such as metal wire, as an example of an attempt to provide both puncture and impact protection. have.

European Patent Application No. 670,466, published on September 6, 1995, describes a shock and puncture prevention system in which chainmail is inserted into a polymer resin to impart knife puncture protection.

<Overview of invention>

The present invention provides a protective fabric comprising a plurality of fabric layers comprising polybenzoxazole (PBO) or polybenzothiazole (PBT) fibers, a plurality of densely woven fabric layers, and a network of fibrous layers of impact protective fabrics. For composite structures, the structure has an inner surface and an outer surface, wherein the plurality of densely woven anti-woven fabric layers are located closer to the outer surface, i.e., the impact surface against penetration threats, than the plurality of impact protection layers.

Compared to other protective composites that are commonly used, the present invention provides a knife and ice pick stab that, on the one hand, provides greater protection against a given weight and, on the other hand, equal protection at lighter weights. A protective composite in the field of protection. The composite of the present invention is flexible and provides excellent protection against impact threats.

1 is an enlarged elevation view of a composite of the present invention.

Knife and ice awl puncture protection is often considered a secondary property after impact protection, but efforts have been made to improve the composite for knife and ice awl puncture protection. In general, knife and ice prick protection is required for garments worn by escorts, police officers, and the like, and impact protection is also a desirable feature of such garments. Such garments should be as flexible as possible to ensure sufficient comfort for easy wearing.

The subject matter of the present invention lies in the use of specific combinations of three different material layers that provide the desired protective performance, while the other layers each exhibit inherent utility in the combination.

Materials in such hybrid composites that are primarily effective in preventing knife stabbing are polybenzoxazoles or polybenzothiazoles that exist in the form of fibers in the woven layer.

Polybenzoxazoles and polybenzothiazoles are generally as described in International Publication No. 93/20400, supra, incorporated herein by reference. The polybenzoxazole and polybenzothiazole are preferably composed of mer of the following structures.

Aromatic groups indicated as being connected to a nitrogen atom may be heterocycles but are preferably carbocycles, and they may be fused or unfused polycyclic systems but are preferably single six-membered rings. The group indicated in the main chain of bis-azole is preferably a para-phenylene group, but this group may be substituted with any divalent organic group that does not interfere with the polymer preparation, or may be free of any groups. For example, the group may be an aliphatic group having 12 or less carbon atoms, tolylene, biphenylene, bis-phenylene ether, and the like.

The polybenzoxazoles and polybenzothiazoles used to make the fibers of the invention should have at least 25, preferably at least 100 mer units. The manufacturing method of this polymer and the spinning method of these polymers are described in the above-mentioned international patent publication 93/20400.

Polybenzoxazole and polybenzothiazole fibers are woven in the form of any fabric commonly used, for example plain weave, crowfoot weave, basket weave and runner weave. Plain weave is preferred.

Any linear density fibers and yarns are believed to be effective in increasing knife puncture protection in the present invention. The preferred linear density for the individual fibers should be 0.3 to 17 dtex, with 0.5 to 3.5 dtex being most preferred. Yarns in the range of 100 to 3300 dtex are preferred, with 220 to 1700 dtex being most preferred. Yarns with linear densities greater than 3300 dtex are generally more difficult to manufacture and use effectively, and yarns with linear densities less than 100 dtex are difficult to weave without damaging the yarns.

The materials of the hybrid composites that are primarily effective in preventing ice awl puncture and impact protection can be polyamides and polyolefins, among others; It may also be polybenzoxazole and polybenzothiazole.

If another polymer is polyamide, aramid is preferable. "Aramid" means a polyamide wherein at least 85% of the amide (-CO-NH-) bond is directly attached to the two aromatic rings. Suitable aramid fibers are described in Man-Made Fibers-Science and Technology, Vol. 2, Section titled Fiber-Forming Aromatic Polyamides, page 297, W. Black et al., Interscience Publishers, 1968. Aramid fibers are also described in US Pat. No. 4,172,938; 3,869,429; 3,819,587; 3,673,143; US Pat. 3,354,127 and 3,094,511.

Additives can be used with the aramid and can be blended with the aramid in large amounts up to 10% by weight of other polymeric materials, or copolymers or diacid chlorides or aramids in which the diamine in the aramid is substituted as much as 10% It has been found that copolymers substituted as much as 10% with other diacid chlorides can be used.

Preferred aramids are para-aramids and poly (p-phenylene terephthalamide) (PPD-T) is preferred para-aramid. PPD-T is a homopolymer produced by mole-to-mole polymerization of p-phenylene diamine and terephthaloyl chloride, and also a copolymer produced by mixing a small amount of other diamine with p-phenylene diamine and a small amount of other diacid. It means a copolymer produced by mixing chloride and terephthaloyl chloride. In general, other diamines and other diacid chlorides may be used in large amounts or slightly more than about 10 mole percent of p-phenylene diamine or terephthaloyl chloride, provided that the other diamine and diacid chloride are polymerized. There should be no reactive groups which would interfere with this. PPD-T can also be mixed with other aromatic diamines with other aromatic diacid chlorides, for example 2,6-naphthaloyl chloride or chloro- or dichloroterephthaloyl chloride, or 3,4'-diaminodiphenylether It means the produced copolymer.

If the other polymer is polyolefin, polyethylene or polypropylene is preferred. Polyethylenes may contain small amounts of branched or comonomers that do not exceed 5 modified units per 100 main chain carbon atoms, and may also contain up to about 50% by weight of one or more polymerizable additives (eg, alkene- Mono-polymers, especially low density polyethylene and propylene and the like) or low molecular weight additives (e.g., commonly incorporated antioxidants, lubricants, ultraviolet screening agents and coloring agents, etc.) By linear polyethylene material. Such polyolefins are commonly known as extended chain polyethylene (ECPE). Likewise, polypropylene is preferably a predominantly linear polypropylene material having a molecular weight of at least one million. High molecular weight linear polyolefin fibers are commercially available. The preparation of polyolefin fibers is disclosed in US Pat. No. 4,457,985.

In general, flexible articles having ice auger penetration protection are made using a fabric layer woven from a high stiffness and high toughness yarn material; The degree of protection against ice awl penetration is a function of yarn density and weaving density, among others. The lower the line density of the yarn and the denser the fabric, the greater the protection against penetration of the ice awl.

"Fabric density" and "cover factor" are terms given for fabric weaving density. Coverage is a calculated value for the geometry of the fabric, which indicates the percentage of the total surface area of the fabric covered by the yarns of the fabric. The equation used to calculate the coverage is as follows (Weaving: Conversion of Yarns to Fabric, Lord and Mohamed, published by Merrow (1982), pages 141-143).

d _w = width of the slope in the fabric

d _f = width of the weft in the fabric

P _w = pitch of slopes (ends per unit length)

P _f = pitch of weft

Depending on the type of weaving the fabric, the maximum coverage may be quite low, even if the yarns of the fabric are laid tight together. For that reason, a more useful index of weaving density is called "fabric density". Fabric density is a measure of the density of fabric weaving compared to maximum weave density as a function of coverage.

For example, the maximum possible coverage for plain fabrics is 0.75; If the actual coverage of the plain fabric is 0.68, the fabric density will be 0.91. Preferred weaving in the practice of the present invention is plain weave.

Flexible impact resistant articles are made using sufficient layers of reinforcing and high toughness reticulated fiber material to be effective against specific impact threats. The layer may be in the form of reticulated fibers and may comprise polyamide fibers, polyolefin fibers or other fibers commonly used for impact protection; Polybenzoxazole or polybenzothiazole fibers.

A woven fabric may be a woven, knitted or nonwoven structure, meaning nonwoven is processed with felt of unidirectional (when included in the matrix resin) and the like. Fabric refers to any fabric commonly used, such as plain weave, triangular weave, basket weave and runner weave.

Impact-protective fabrics generally use relatively high-density yarns and, in the case of textiles, have little to do with the density of weaving, except to avoid extremely dense weaving to avoid damaging the yarn fibers due to the stringency of the weaving. .

Certain combinations of the present invention using special anti- penetration materials and impact protection materials provide much greater ice augment and knife penetration protection and good impact resistance than would be expected from the sum of penetration protection of individual components in the combination. Indicates. Individual components in the combination of the present invention have a specific component to component relationship.

The primary knife penetration prevention layer of polybenzoxazole or polybenzothiazole fabric can be located anywhere in the composite of the present invention. In general, more than one layer of such fabric is required to provide the desired knife sticking ability. Each layer of polybenzoxazole and polybenzothiazole generally has a surface density of 75 to 450 g / m 2, and generally 1 to 15 layers are used. The surface density of the layer depends greatly on the type of the fiber and the type and linear density of the fiber. However, polybenzoxazole and polybenzothiazole fibers generally comprise from 10 to 90% by weight, preferably from 15 to 50% by weight of the total composite.

The primary ice awl puncture resistant fabric layer is made from densely woven yarns of high strength fibers, which yarns generally have a linear density of less than 500 dtex, preferably the individual fibers of these yarns have a linear density of 0.2 to 2.5 dtex, More preferably, it is 0.7-1.7 dtex. These layers can be prepared from polyamides, polyolefins, polybenzoxazoles, polybenzothiazoles, or other fibers commonly used for penetration prevention. Preferred materials for these layers are para-aramidyans. Preferred linear densities of these yarns are from 100 to 500 dtex, and these yarns are preferably woven to a fabric density of 0.75 to 1.00 or perhaps more, more preferably greater than 0.95. The relationship between yarn dtex and fabric density in a densely woven fabric layer is most preferred in the following cases, as disclosed in US Pat. No. 5,578,358, above.

Y> X 6.25 × 10 ^-4 + 0.69

Where Y is the fabric density and X is the line density of the yarn.

The primary impact protection layer may or may not be woven, or may be a unidirectional single fabric or the like if not woven. The layer can be prepared from polyamide, polyolefin, polybenzoxazole, polybenzothiazole, or other polymers commonly used in impact protection layers. Preferred constructions for these impact protection layers are woven para-aramidyans having a linear density of 50 to 3000 dtex. Plain weave is preferred when weaving, but other weaving types may be used, such as basket weave, runner weave or twill weave. Preferred para-aramid is poly (p-phenylene terephthalamide).

Yarns used in any of the fabric layers of the present invention have a high stiffness of 20 grams / dtex to 50 grams / dtex, an elongation at break of at least 2.0% to 6% or more, and a modulus of at least 270 grams / dtex to 2000 It should be large in grams / dtex or more.

Combinations of the three components of the present invention are made by placing these three components together face to face, with or without other layer material between them if desired. Other layer materials that may be disposed between these three components include, for example, waterproof materials and damage prevention materials.

Improved ice auger and knife penetration protection can be obtained using only two of the components according to the invention. According to the invention, the combination of a plurality of woven polybenzoxazole or polybenzothiazole fiber layers and a plurality of tightly woven anti-penetration layers is much larger than the sum of the anti-penetrating properties exhibited by the components used separately. And prevention of knife penetration.

The layers forming the zone of such composites can be joined together, for example by sewing together, or they can be stacked together to contain, for example, a fabric envelope. The layers that make up each zone are usually arranged together, so that the composite can be seen as a structure with distinct zones of layers.

The high knife puncture protection of the present invention is provided by polybenzoxazole or polybenzothiazole fiber layers. The polybenzoxazole or polybenzothiazole fiber layer can be located anywhere in the article. The high ice auger penetration protection of the present invention is provided by a densely woven fabric layer, wherein the tightly woven fabric layer is impacted against the impact-impact side of the ice auger threat to realize a high ice auger prevention. It should be placed closer than the protective layer. The high impact protection penetration protection of the present invention is provided by an impact protection layer that can be placed anywhere in the article of the present invention except that it can be placed on the impact surface.

In view of the limitations on the location of such components, it is understood that only three different alignments exist for the components of the combination of the present invention. That is, from the outer or impact surface (1) a polybenzoxazole or polybenzothiazole layer, a densely woven layer, an impact protective layer; (2) a densely woven layer, an impact protective layer, a polybenzoxazole or polybenzothiazole layer; And (3) a densely woven layer, a polybenzoxazole or polybenzothiazole layer, an impact protective layer.

1 consists of a zone 11 consisting of woven polybenzoxazole or polybenzothiazole layers 12, a zone 13 consisting of densely woven layers 14, and an impact protective material layer 16. A protective composite 10 of the present invention having a zone 15 is shown. Layers 12 and 14 may be combined with each other in any order such that zones 11 and 13 are not distinguished from each other, although the layers of zone 13 are more impact resistant than the layers of zone 15. It is important to be closer.

<Test method>

Linear density

The linear density of the yarns was measured by weighing yarns of known length. "dtex" is defined as the weight in grams of 10,000 meter yarn length.

In practice, the measured dtex, test conditions, and sample validation records of the yarn samples were entered into the computer before starting the test; The computer recorded the load-elongation curve at yarn break and calculated its properties.

Tensile properties

First, the yarn for tensile properties testing was conditioned and then twisted so that the twist multiplier was 1.1. Yarn's twist multiplier (TM) is defined as follows.

TM = (turns / cm) (dtex) ^1/2 /30.3

The yarn to be tested was conditioned for at least 14 hours under test conditions of 25 ° C. and 55% relative humidity, and a tensile test of the yarn was performed at this condition. Stiffness (break stiffness), elongation at break and modulus were measured by breaking test yarns on an Instron tester (Instron Engineering Corp .; Canton, Mass., USA).

Stiffness, elongation and initial modulus as defined in ASTM D2101-1985 were measured using yarns with a gauge length of 25.4 cm and elongation of 50% strain / min. The modulus is calculated from the slope of the stress-strain curve at 1% strain, which is equal to the stress (grams) at 1% strain (absolute value) multiplied by 100 divided by the linear density of the test yarn.

Penetration prevention

Knife penetration protection is a bonding knife (Russell) with a single-blade blade that is 15 cm (6 inches) long, about 2 cm (0.8 inches) wide, tapered towards the end and has a Rockwell hardness of C-55. Measurements were made on samples to be tested using Russell Harrington Cutlery, Inc .; Southbridge, Mass., USA. The test was H.P. It was performed according to HPW test TP-0400.03 (November 28, 1994) from H.P. White Lab., Inc. A test sample placed on a 10% gelatin backing was impacted with a knife weighing 4.55 kg (10 pounds) at various heights until the sample penetrated greater than 6 mm under test conditions. Ice auger penetration was measured by the same procedure as above, except that instead of a bonding knife, an ice auger of Rockwell hardness C-42 having a length of 18 cm (7 inches) and a shaft diameter of 0.64 cm (0.25 inches) was used. The results were reported as penetrating energy (joules) by multiplying the kilogram-meter from the energy at the penetrating height by 9.81.

Shock protection

The impact protection test of the multilayer panel measured the impact limit value (V50) according to MIL-STD-662e, except that the choice of projectile was as follows: hold the test panel firmly perpendicular to the path of the test projectile. Roma Plastina No. in installed samples. It was placed against one clay backing material. The projectile was a 9 mm all metal jacketed pistol bullet weighing 124 grains and was fired from a test gun capable of firing the projectile at different speeds. The first firing for each panel was at projectile velocity estimated to be near impact limit (V50). When the first shot completely penetrated the panel, the next shot reduced the projectile speed by approximately 15.5 m / s (50 ft / s) to partially penetrate the panel. On the other hand, if not or partially penetrated in the first foaming, the next foaming increased the speed by approximately 15.2 m / s (50 ft / s) to fully penetrate. Once partially penetrated by the projectile and once fully penetrated, increase or decrease the subsequent speed by approximately 15.2 m / s (50 ft / s) until sufficient firing to determine the impact threshold (V50) for the panel. Used.

The impact threshold (V50) is calculated by arithmetic averaging at least three of the same partial penetration maximum velocity and the minimum full penetration impact velocity, except that the difference between the highest and lowest individual impact velocity is 38.1 m / s (125 ft / s). )

<Production of floor>

A number of different yarns were woven or made into a fabric or a layer of fiber and then made into a composite structure for conducting puncture protection tests.

1. A plain fabric of 1560 denier (1733 dtex) polybenzoxazole yarns was prepared with a surface density of 0.47 lb / ft ² (2.3 kg / m 2) at 21 × 21 ends / inch (8.3 × 8.3 ends / cm). The yarn was purchased from Toyobo Co., Ltd. under the trade name Zylon (registered trademark).

2. Plain fabrics of 400 denier (444 dtex) poly (p-phenylene terephthalamide) yarns were subjected to 31 x 31 ends / inch (12.2 x 12.2 ends / cm) with a surface density of 0.92 lb / ft ² (4.49 kg / m 2). ) This is Yan. children. It was purchased from EI du Pont de Nemours and Company under the trade name Kevlar (registered trademark).

3. A plain fabric of 650 denier (722 dtex) polyethylene yarns was prepared with a surface density of 0.50 lb / ft ² (2.44 kg / m 2) at 35 × 35 ends / inch (13.8 × 13.8 ends / cm). The yarn was purchased under the trade name Spectra 900 from AlliedSignal, Inc.

4. A unidirectional stretched polyethylene fiber (UDECPE) layer with a surface density of 0.51 lb / ft ² (2.49 kg / m 2), crossplied and sandwiched with a polyethylene film in the 0/90 degree direction, was used. This layer was purchased from Allied Signal Inc. under the trade name Spectra Shield Plus (registered trademark) as a finished product.

<Example 1>

Combinations of polybenzoxazole (PBO) layers with other polymer layers were assembled and tested for puncture protection; The results were compared to structures of equivalent surface density made from polybenzoxazole alone or from other polymers alone. The results are shown in the table below.

Configuration Penetrating Energy (J) Surface density (psf) (kgsm) 8 layers (PBO) plain weave 8.3 x 8.3 22.6 0.47 2.30 40 layers (PPDT) plain weave 12.2 x 12.2 18.1 0.92 4.49 12 layers (ECPE) plain weave 13.8 x 13.8 11.3 0.50 2.44 22 floors (UDECPE) 20.3 0.51 2.49 8 layers (PBO) (T) 40 layers (PPDT) (B) 67.8 1.39 6.79 40 layers (PPDT) (T) 8 layers (PBO) (B) 61.0 1.39 6.79 8 layers (PBO) (T) 12 layers (ECPE) (B) 76.8 0.97 4.74 12 layers (ECPE) (T) 8 layers (PBO) (B) 50.8 0.97 4.74 8 layers (PBO) (T) 22 layers (UDEDPE) (B) 74.6 0.98 4.78 22 floors (UDECPE) (T) 8 floors (PBO) (B) 45.0 0.98 4.78 (T) indicates the top or outer surface (of the knife stab) (B) indicates the bottom or inner surface

It can be seen that the composite structure of the present invention provides much higher penetration energy than would be expected from simply combining the components of the individual zones of the combination. It can also be seen that the anti-penetration ability is significantly higher when the polybenzoxazole zone is located on top (exposed to knife stab).

<Example 2>

Additional fabrics were woven in this example for use in combination with the fabrics from the above examples.

5. Plain fabrics of 200 denier (222 dtex) poly (p-phenylene terephthalamide) yarns with a surface density of 0.26 lb / ft ² (1.26 kg / m 2) at 70 × 70 ends / inch (27.5 × 27.5 ends / cm ) This is Yan. children. Purchased under the trade name Kevlar® from Dupont Di Nemoa & Company.

The combination of layers was assembled to test for knife and ice auger penetration and impact protection in both cases; The results were compared with the structures made with only a single component. The results are shown in the table below.

Configuration Surface density (㎏ / ㎡) Penetrating Energy (J) Impact limit V ₅₀ (m / sec) knife Ice drill 8-layer PBO plain weave 8.3 x 8.3 2.30 22.6 <0.5 - 40 floors, 400d PPDT plain weave 12.2 x 12.2 4.49 18.1 0.9 523 10 layers, 200d PPDT plain weave 27.5 x 27.5 1.26 1.8 20.1 - 10 layers, 8 layers of 200d PPDT (T), 40 layers of PBO (M), 400d PPDT (B) 8.05 68.3 > 180 572 8 layers, 10 layers of PBO (T), 40 layers of 200d PPDT (M), 400d PPDT (B) 8.05 85.0 80.5 - compare 40 layers, 400d PPDT (T), 8 layers, 10 layers of PBO (M), 200d PPDT (B) 8.05 58.9 14.6 - (T) indicates the top or puncture (M) indicates the middle (B) indicates the bottom or the inner surface

It can be seen that the composite structures of the present invention provide much higher penetration energy than would be expected from simply combining each individual component of the combination. It can also be seen that the penetration energy is poor for the comparative composite where the densely woven layer is closer to the inner surface than the impact resistant layer.

Claims (17)

a) a plurality of fabric layers comprising polybenzoxazole or polybenzothiazole fibers, b) a plurality of densely interwoven fabric layers, c) reticular fibrous layers of multiple impact protection fabrics And an outer surface and an inner surface, wherein the plurality of densely woven through barrier layers are located closer to the outer surface than the plurality of impact protection layers. The composite of claim 1, wherein the densely woven through-proof fabric comprises polyamide fibers. The composite of claim 2, wherein the polyamide fiber is para-aramid. The composite of claim 1, wherein the densely woven anti-penetration fabric comprises polyolefin fibers. The composite of claim 4 wherein said polyolefin fibers are polyethylene. The composite of claim 1, wherein the densely woven through-proof fabric comprises polybenzoxazole or polybenzothiazole fibers. The composite of claim 1, wherein the impact protective fabric layer is made from fibers having an elongation at break greater than 2.0%, modulus greater than 270 grams per dtex, and stiffness greater than 20 grams per dtex. The composite of claim 1, wherein the impact protection layer comprises polyamide fibers. The composite of claim 8, wherein the polyamide fiber is para-aramid. The composite of claim 1, wherein the impact protection layer comprises polyolefin fibers. The composite of claim 10 wherein said polyolefin fibers are polyethylene. The composite of claim 1, wherein the impact protection layer comprises polybenzoxazole or polybenzothiazole fibers. The composite of claim 1, wherein the densely woven through-proof fabric comprises a fabric woven at a fabric density of at least 0.75 from aramid yarns having a linear density of less than 500 dtex. The composite of claim 1, wherein the polybenzoxazole or polybenzothiazole fibers are present as yarns having a linear density of 100 to 3300 dtex, and the fibers have a linear density of 0.3 to 17 dtex. a) a plurality of fabric layers comprising polybenzoxazole or polybenzothiazole fibers, b) a plurality of densely interwoven fabric layers Including, knife and ice awl penetration prevention article. 16. The article of claim 15, wherein the plurality of densely woven through-proof fabric layers have a fabric woven at a fabric density of at least 0.95 from aramid yarns having a linear density of less than 500 dtex. 16. The article of claim 15, wherein the plurality of densely woven through fabric layers have a fabric woven at a fabric density of at least 0.95 from polybenzoxazole or polybenzothiazole yarns having a linear density of less than 500 dtex.