JP2006207965A - Cloth for bulletproof clothing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively provide an inexpensive cloth for bulletproof clothing having a high mechanical property (a toughness factor), superior process stability in a manufacturing process, and superior bulletproof performance. <P>SOLUTION: The cloth is composed of all aromatic polyamide filaments containing carbon nanotubes, and 0.5-5wt.% carbon nanotubes with respect to overall weight of the all aromatic polyamide filaments is contained in the all aromatic polyamide filaments. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a bulletproof clothing fabric, and more particularly to a bulletproof clothing fabric composed of wholly aromatic polyamide filaments containing carbon nanotubes.

  In recent years, there has been a great interest in increasing the added value and performance of polymers. As one means for that purpose, development of a composite material in which a filler, that is, a filler is dispersed and mixed in a polymer has been actively conducted.

  Up to now, fibrous and acicular fillers have been used for the purpose of improving the mechanical properties and heat resistance of polymers. Tensile strength, elastic modulus, bending strength, thermal dimensional stability, improved creep properties, warpage It is known that various physical properties such as improvement of wear, wear resistance, surface hardness, heat resistance, and marching resistance are improved.

  For example, Japanese Patent Application Laid-Open No. 2003-119622 (Patent Document 1) discloses a polybenzazole fiber containing 5% by weight or more of carbon nanotubes and improving its compressive strength, and the fiber is in the form of a fabric. It is also described that it can be used for purposes such as bulletproof clothing.

  However, in the case of a cloth-like ballistic resistant material, simply improving the compressive strength of the constituent fibers may lower the impact-absorbing ability of the fabric, and the polymer material generally containing a filler Since there is a defect that the elongation is lowered, there is a problem that even if a filler or polymer exhibiting high strength and high elasticity is used, it is not always possible to obtain a fabric excellent in bulletproof performance.

Furthermore, polybenzazole fiber is very expensive, and as a result, there is a problem that the bulletproof material made of the fiber becomes extremely expensive, and the appearance of a bulletproof material that is inexpensive and excellent in bulletproof performance has appeared. It has been longing for.
JP 2003-119622 A

  The present invention has been made against the background of the above-described prior art, and its purpose is to have high mechanical properties (toughness factor), excellent process stability in the manufacturing process, low cost, and excellent bulletproof performance. The object is to provide a fabric for bulletproof clothing.

  As a result of intensive studies to solve the above problems, the inventors of the present invention can obtain a fabric having excellent ballistic performance (toughness factor) when the fabric is composed of wholly aromatic polyamide filaments containing carbon nanotubes. And the present invention was reached.

  That is, according to the present invention, a fabric composed of wholly aromatic polyamide filaments containing carbon nanotubes, wherein the wholly aromatic polyamide filaments have no carbon nanotubes relative to the total weight of the wholly aromatic polyamide filaments. The cloth for bulletproof clothing characterized by containing 5 to 5 weight% is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the fabric for bulletproof clothing which has a high mechanical physical property (toughness factor), is excellent in process stability in a manufacturing process, is inexpensive, and is excellent in bulletproof performance is provided.

Hereinafter, embodiments of the present invention will be described in detail.
The wholly aromatic polyamide used in the present invention can be obtained from low-temperature solution polymerization or interfacial polymerization of dicarboxylic acid dichloride and diamine in solution. Specific examples of the diamine component used in the present invention include p-phenylenediamine, 2-chloro p-phenylenediamine, 2,5-dichloro p-phenylenediamine, 2,6-dichloro p-phenylenediamine, and m-phenylene. Examples thereof include diamine, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfone, and 3,3′-diaminodiphenyl sulfone. However, it is not limited to these.

  Of these, p-phenylenediamine, m-phenylenediamine and 3,4′-diaminodiphenyl ether are preferred as the diamine component.

  Specific examples of the dicarboxylic acid chloride component used in the present invention include, for example, isophthalic acid chloride, terephthalic acid chloride, 2-chloroterephthalic acid chloride, 2,5-dichloroterephthalic acid hundred chloride, 2,6-dicarboxylic acid. Examples include, but are not limited to, chloroterephthalic acid chloride and 2,6-naphthalenedicarboxylic acid chloride. Of these, terephthalic acid dichloride and isophthalic acid dichloride are preferred as the dicarboxylic acid chloride component. Accordingly, examples of the wholly aromatic polyamide in the present invention include copolyparaphenylene • 3,4′-oxydiphenylene terephthalamide, polyparaphenylene terephthalamide, and polymetaphenylene terephthalamide.

  Further, as a solvent for polymerizing wholly aromatic polyamide, specifically, organic polar amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, Water-soluble ether compounds such as tetrahydrofuran and dioxane, water-soluble alcohol compounds such as methanol, ethanol and ethylene glycol, water-soluble ketone compounds such as acetone and methyl ethyl ketone, and water-soluble nitrile compounds such as acetonitrile and propionitrile. . These solvents can be used as a mixed solvent of two or more, and are not particularly limited. The solvent is preferably dehydrated.

  In this case, in order to increase solubility, an appropriate amount of a generally known rough salt may be added before, during or after the polymerization. Examples of such inorganic salts include lithium chloride and calcium chloride.

  The polymer concentration of the wholly aromatic polyamide solution used in the production of the wholly aromatic polyamide is preferably 0.5 to 30% by weight, more preferably 1 to 25% by weight. When the polymer concentration is less than 0.5% by weight, there are cases where there is little entanglement of the polymer and sufficient stretching cannot be performed. On the other hand, when the polymer concentration exceeds 30% by weight, unstable flow tends to occur when discharging from the nozzle, and it may be difficult to perform stable spinning.

  Moreover, when manufacturing a wholly aromatic polyamide, these diamine components and acid chloride components are preferably 0.90 to 1.10, more preferably 0.95 to 1.0 as the molar ratio of the diamine component to the acid chloride component. It is preferable to use in the range of 05.

  The ends of this wholly aromatic polyamide can also be sealed. In the case of sealing with an end-capping agent, examples of the end-capping agent include phthalic acid chloride and substituted products thereof, and examples of the amine component include aniline and substituted products thereof.

  In the reaction of generally used acid chloride and diamine, an aliphatic or aromatic amine or a quaternary ammonium salt can be used in combination to trap an acid such as hydrogen chloride formed.

  After completion of the reaction, a basic inorganic compound such as sodium hydroxide, potassium hydroxide, calcium hydroxide, calcium oxide or the like is added as necessary to carry out a neutralization reaction. The reaction conditions do not require special restrictions. The reaction between acid chloride and diamine is generally rapid, and the reaction temperature is, for example, -25 ° C to 100 ° C, preferably -10 ° C to 80 ° C.

  The wholly aromatic polyamide thus obtained can be put into a non-solvent such as alcohol or water, precipitated, and taken out as a pulp. This can be dissolved again in another solvent and used for molding, but the solution obtained by the polymerization reaction can be used as it is as a molding solution. The solvent used for re-dissolving is not particularly limited as long as it dissolves the wholly aromatic polyamide, but a solvent used for the polymerization of the wholly aromatic polyamide is preferable.

  The carbon nanotube used in the present invention is a tubular compound consisting essentially of carbon, and the number of layers may be either a single layer or multiple layers. As a manufacturing method, an arc discharge method, a vapor phase growth method, and the like are known (for example, Japanese Patent Application Laid-Open No. 2001-80913), and carbon nanotubes obtained by any method may be used. The carbon nanotube has an outer diameter of 100 nm or less and a length of 0.5 μm to 10 μm, preferably 1 μm to 5 μm. When the outer diameter exceeds 100 nm or the length exceeds 10 μm, it is difficult to uniformly disperse the fibers in the fiber as will be described later. On the other hand, when the length of the carbon nanotube is less than 0.5 μm, the carbon nanotube is not sufficiently oriented in the fiber axis direction in the spinning process and may not contribute to the improvement of the strength.

  In the present invention, fillers other than carbon nanotubes can be used in combination as long as the physical properties are not impaired. Examples of the filler used include non-fibrous fillers such as fibrous, plate-like, scale-like, granular, indeterminate shapes, and crushed products. Specific examples include glass fiber, polyacrylonitrile-based, and pitch-based carbon. Fibers, stainless steel fibers, metal fibers such as aluminum fibers and brass fibers, organic fibers such as wholly aromatic polyamide fibers, gypsum fibers, ceramic fibers, asbestos fibers, zirconia fibers, alumina fibers, silica fibers, titanium oxide fibers, silicon carbide fibers , Rock wool, potassium titanate whisker, barium titanate whisker, aluminum borate whisker, silicon nitride whisker, mica, talc, kaolin, silica, calcium carbonate, glass beads, glass flakes, glass microballoon, clay, molybdenum disulfide , Wollastonite, oxidation Examples thereof include titanium, zinc oxide, calcium polyphosphate, graphite, metal powder, metal flake, metal ribbon, metal oxide, carbon powder, graphite, carbon flake, and scaly carbon. Moreover, said filler can also be used in combination of 2 or more types.

  The filler used in the present invention can be used by treating the surface with a known coupling agent (for example, silane coupling agent, titanate coupling agent, etc.) or other surface treatment agents.

  In the present invention, it is necessary that the filament made of the wholly aromatic polyamide contains carbon nanotubes in the range of 0.5 to 5% by weight with respect to the total weight of the wholly aromatic polyamide filament. When the content is less than 0.5% by weight, the toughness factor is not improved. On the other hand, when the content exceeds 5% by weight, it is difficult to uniformly disperse the carbon nanotubes in the spinning solution. .

  The wholly aromatic polyamide filament containing the carbon nanotubes can improve the tensile strength (T) by 10% or more compared to those not containing carbon nanotubes. In addition, the wholly aromatic polyamide filament of the present invention can improve the elongation (E) by 10% or more as compared with those not containing carbon nanotubes.

  Further, the wholly aromatic polyamide filament containing the carbon nanotubes has a toughness factor (TF) of 10% or more, preferably 20% or more, and a toughness of 30 or more as compared with those containing no carbon nanotubes. It is possible to obtain wholly aromatic polyamide filaments with factors. Here, the toughness factor (TF) is represented by the product of the tensile strength (T) measured in units of grams / denier and the square root of elongation (E), as represented by the following formula. .

  Although the wholly aromatic polyamide filament of the present invention has high mechanical properties (tensile strength, elongation, and toughness factor) and is made into a fabric, it is not clear as a reason for having excellent ballistic performance, It is considered that the carbon nanotubes are highly oriented in the fiber axis direction by stretching and orientation in the spinning process.

  For example, when the orientation degree of the carbon nanotube in the filament used in the present invention is analyzed by X-ray measurement, the orientation degree A calculated by the following formula from the reflection peak intensity of (002) is preferably 50% or more. More preferably, it is 70% or more, and further preferably 80% or more.

  The degree of orientation A is a parameter indicating the orientation of the filler in the filament. A = 0 when there is no orientation of the carbon nanotube layer surface, and A when the layer surface is aligned completely parallel to the filament fiber axis direction. = 100.

  In the present invention, the carbon nanotubes are selectively oriented in the fiber axis direction with a high degree of orientation A of 50% or more, more preferably 70% or more in the wholly aromatic polyamide filament, whereby mechanical properties (toughness) Factor) and the resulting improvement in ballistic performance.

  In the present invention, the method for producing a wholly aromatic polyamide filament is not particularly limited, but a spinning solution (dope) comprising a wholly aromatic polyamide, carbon nanotubes and a solvent is prepared, and the obtained dope is discharged from a nozzle. It can be produced by coagulation in a coagulation bath comprising a poor solvent and drying.

  Further, as the solvent used for the dope for spinning, it is possible to use a solvent that can dissolve and / or disperse the wholly aromatic polyamide and the carbon nanotube, such as the solvent used in the production of the wholly aromatic polyamide. These solvents can also be used as a mixed solvent of two or more.

  The polymer concentration of the dope for spinning, that is, the concentration of wholly aromatic polyamide is 0.05 to 30% by weight, more preferably 1 to 25% by weight.

  The spinning dope comprising a wholly aromatic polyamide, carbon nanotubes and a solvent is prepared by (a) adding carbon nanotubes to a solution of wholly aromatic polyamides, (a) a solution of wholly aromatic polyamides and a solution of carbon nanotubes. And (c) a method in which a wholly aromatic polyamide is added to a carbon nanotube solution and dissolved. Further, the dope for spinning in the present invention includes other components within a range not impairing the effects of the present invention, such as antioxidants, heat stabilizers, weathering agents, dyes, antistatic agents, flame retardants, conductive polymers, and others. The polymer can be added.

Using the spinning dope obtained by the above method, the fiber is formed into a fiber by a wet method, a semi-dry semi-wet method, etc., and after removing the solvent, the fully aromatic polyamide filament of the present invention is produced by drying. be able to. Further, it is considered that by stretching the obtained molded body, the fully aromatic polyamide as the polymer matrix and the carbon nanotubes used as the filler are highly oriented, and the high physical properties of the fully aromatic polyamide filament are expressed.

  As a drawing method, washing drawing in a coagulated yarn state, boiling water drawing, heating drawing in a dry yarn state, or the like can be performed. The draw ratio is not particularly limited, but is preferably 1.05 times or more, more preferably 1.1 times or more. When the draw ratio is less than 1.05 times, the polymer The orientation of the carbon nanotubes in the matrix is insufficient, which is not preferable. Moreover, the elongation and strength of the wholly aromatic polyamide filament can be controlled by controlling the draw ratio.

  In the present invention, the wholly aromatic polyamide filament is used in the form of a fabric such as a woven fabric, a knitted fabric or a non-woven fabric. At this time, when used in the form of a woven fabric, the fully aromatic polyamide filaments are arranged in one direction, so that the performance of the fibers is easily exhibited, and the high bulletproof performance that is the object of the present invention is easily achieved.

  The cover factor (CF) represented by the following formula of the fabric is preferably 2500-3500. When the cover factor (CF) is in the above range, the form of the woven structure is easily maintained, and the texture is difficult to open. Therefore, the fibers are not displaced by landing, and the loss of fiber performance is reduced, and high ballistic performance is exhibited.

The above fabric may be used alone or in combination with other fiber fabrics. At this time, it is preferable to use a fiber fabric having a tensile strength of 18 cN / dtex or more, such as other aramid fibers, polyarylate fibers, and high-strength polyethylene fibers.

  Hereinafter, the present invention will be described more specifically with reference to examples. In addition, each characteristic in an Example was evaluated in accordance with the following method.

(1) Bulletproof performance Bulletproof performance was evaluated using a 9 mm handgun. The sample to be evaluated was fixed on a 10 cm thick clay so as not to move with a belt or the like, and set at an angle such that the bullet was perpendicular to a position 5 m from the muzzle.

Since the speed of the bullet is constant, the total basis weight was changed by increasing or decreasing the number of stacked samples, and the evaluation was performed based on the basis weight where the bullet did not penetrate the sample (non-penetrating minimum basis weight). Evaluation is repeated four times under the same conditions, and it is determined that no penetration occurs when there is no single penetration.
Note that the size of the sample was sufficiently large so as not to be affected by the damage given to the sample by other test bullets.

  The bullet used in the performance evaluation is a 9mm bullet, the shape is a full metal jacket covered with lead and the weight is 8.0g. The speed of the bullet fired from the handgun was 345 m / s.

[Example 1]
As the carbon nanotubes to be added, multi-walled carbon nanotubes (hereinafter sometimes referred to as MWNTs) produced by a vapor phase growth method and having a plurality of carbon sheets stacked on concentric circles were used. The tube diameter of the multi-walled carbon nanotube was 40 nm, and the aspect ratio was 110.

  The carbon nanotubes are dispersed using a bead mill (NanoGrainMi1l) manufactured by Asada Tekko Co., Ltd., and NMP is 0.3 wt% in N-methyl-2-pyrrolidone (hereinafter sometimes referred to as NMP). The dispersion was adjusted. At this time, 0.3 mm zirconia beads were used as media.

  The obtained carbon nanotube dispersion and NMP were placed in an NMP solution having a concentration of 6% by weight of copolyparaphenylene • 3,4′-oxydiphenylene terephthalamide (aromatic polyamide having a copolymerization molar ratio of 1: 1). Then, the carbon nanotubes in the obtained dope were added so that the content of carbon nanotubes was 1% by weight based on the total weight of the aromatic polyamide, and stirred at a temperature of 80 ° C. for 4 hours.

  Using the obtained dope, it was discharged from a spinneret with 667 holes, spun into an aqueous solution with an NMP concentration of 30% by weight through an air gap of about 10 mm (semi-dry semi-wet spinning method), washed with water, After drying, and then stretching 10 times at a temperature of 500 ° C., a fully aromatic polyamide filament in which carbon nanotubes were well dispersed was obtained by winding.

  The total wholly aromatic polyamide filament obtained had a total fineness of 1100 dtex, a filament count of 667 filaments, a single yarn fineness of 1.65 dtex, and a strength of 27.7 cN / dtex.

Using this filament, a warp density of 45 pieces / inch was used to obtain a plain woven fabric having a basis weight of 285 g / m ² (CF = 2985). A plurality of the obtained woven fabrics were stacked, and the bulletproof performance was evaluated according to the above method. The non-penetrating minimum basis weight was 4560 g / m ² (16 sheets).

[Examples 2-3]
In Example 1, it implemented like Example 1 except having added so that content of a carbon nanotube might be 3 weight% or 5 weight% on the basis of the total weight of a wholly aromatic polyamide filament. The results are shown in Table 1.

[Example 4]
In Example 1, instead of using multi-walled carbon nanotubes, the same procedure as in Example 1 was performed, except that single-walled carbon nanotubes (hereinafter sometimes referred to as SWNTs) consisting of only one carbon sheet were used. did. The results are shown in Table 1.

[Comparative Example 1]
In Example 1, it implemented like Example 1 except not having added a carbon nanotube. The results are shown in Table 1.

[Comparative Example 2]
In Example 1, it implemented like Example 1 except having added so that content of a carbon nanotube might be 10 weight% on the basis of the total weight of a wholly aromatic polyamide filament. The results are shown in Table 1.

  As is clear from Table 1, it is recognized that the wholly aromatic polyamide filaments to which carbon nanotubes are added not only improve the strength and modulus, but also greatly improve the ballistic performance as compared with the unadded filaments.

  According to the present invention, since a fabric for bulletproof clothing having high mechanical properties (toughness factor), excellent process stability in the production process, inexpensive and excellent in bulletproof performance is provided, Alternatively, it is useful in application fields such as safety clothing.

Claims (5)

  A fabric composed of wholly aromatic polyamide filaments containing carbon nanotubes, wherein the wholly aromatic polyamide filaments contain carbon nanotubes in an amount of 0.5 to 5% by weight based on the total weight of the wholly aromatic polyamide filaments. A fabric for bulletproof clothing, characterized in that   The cloth for bulletproof clothing according to claim 1, wherein the carbon nanotube is a multi-walled carbon nanotube.   The fabric for bulletproof clothing according to claim 1 or 2, wherein the wholly aromatic polyamide is copolyparaphenylene-3,4'-oxydiphenylene terephthalamide.   The cloth for bulletproof clothing according to claim 1 or 2, wherein the wholly aromatic polyamide is polyparaphenylene terephthalamide. The fabric for bulletproof clothing according to any one of claims 1 to 4, wherein the cover factor (CF) of the fabric represented by the following formula is 2500 to 3500.