Note: Descriptions are shown in the official language in which they were submitted.
CA 02859943 2014-06-19
i.
Specification
[Title of the Invention]
BULLETPROOF FABRIC AND BODY ARMOR MANUFACTURED BY
USING SAME
[Technical Field]
The present invention relates to a bulletproof fabric
and body armor prepared using the same, and more
particularly, to a bulletproof fabric with greatly
improved bulletproofing performance in a condition of
getting wet (hereinafter referred to as a "wet state") and
a body armor manufactured using the same.
[Background Art]
Bulletproof garments(hereinafter referred to as a
body armor) are clothes developed to protect a human body
against shell splinter (broken pieces) of shells and
bullets fired by enemy. The most requirement of such body
armor is a bulletproof performance determining how safely
the human body can be protected against bullets or shells.
In recent years, there is required development of
body armor with excellent bulletproof performances in a
wet state as well as in dry state.
Conventional techniques to produce body armor
include dipping an aramid fabric in a water-repellent
solution containing fluorine resin or the like, padding
and drying the same to prepare a water-repellent aramid
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fabric; and then, stacking up 10 to 50 sheets of the
water-repellent fabric, so as to complete the body armor
with a laminate structure. Such manufactured body armor
have been widely employed in the art.
However, the conventional body armor as described
above involved a demerit of lowered bulletproof
performance in a wet state due to poor water-repellent
treatment, although the bulletproof performance in dry
state was excellent.
Further, at the test of bulletproof performance, the
conventional body armor were found to barely satisfy the
national institute of Justice (NIJ) standards of 44 mm or
less, in terms of rear deformation of body armor.
Therefore, it has entailed a limitation in applying in a
case that more strict standards for rear deformation are
required.
[Summary of the Invention]
[Problems to be Solved by the Invention]
In order to solve the conventional problems as
described above, it is an object of the present invention
to provide a bulletproof fabric with improved water-proof
performance in a wet state and considerably reduced rear
deformation, as compared to NIJ standards for rear
deformation of water-proof clothes at a bulletproof
performance test, and a body armor manufactured using the
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A
same.
[Means for Solving the Problems]
In order to achieve the above object, there is
provided a bulletproof fabric on which two water-repellent
layers, that is, a primary water-repellent coating layer
20 and a secondary water-repellent coating layer 30 are
formed sequentially by conducting water-repellent
treatment of the fabric twice, thereby improving
bulletproof performance in a wet state of a body armor.
In addition, the present invention includes
inserting an aramid composite pad 40 into a pocket provided
at a part of the body armor so as to considerably reduce
rear deformation at a bulletproof performance test,
wherein the aramid composite pad 40 is prepared by
heat-pressing a first aramid prepreg X with a second aramid
prepreg Y to form an integrated laminate structure, and
wherein the first aramid prepreg X includes a high-strength
aramid fabric A and a resin impregnated therein while the
second aramid prepreg Y includes a high-elastic aramid
fabric B and a resin impregnated therein.
[Effects of the Invention]
According to the present invention, water-repellent
performance is excellent to noticeably improve
bulletproof performance in a wet state and, specifically,
when a body armor includes an aramid composite pad 40
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*
inserted therein, rear deformation of the body armor after
a bulletproof performance test may be considerably
reduced.
[Brief Description of the Drawings]
FIG. 1 is a cross-sectional view illustrating a
bulletproof fabric according to the present invention; and
FIG. 2 is a cross-sectional view illustrating an
aramid composite pad to be inserted into a pocket of a body
armor.
[Description of Reference Numerals]
10: aramid fabric, 20: primary water-repellent
coating layer
30: secondary water-repellent coating layer, 40:
aramid composite pad
A: high-strength aramid fabric, B: high-elastic
aramid fabric
C: resin, X: first aramid prepreg
Y: second aramid prepreg
[Modes for Carrying out the Invention]
Hereinafter, the present invention will be described
in more detail with reference to accompanying drawings.
A bulletproof fabric according to the present
invention has a structure in which two water-repellent
coating layers, that is, a primary water-repellent coating
layer 20 and a secondary water-repellent coating layer 30
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*
are sequentially formed on an aramid fabric 10, as shown
in FIG. 1.
In other words, the bulletproof fabric of the present
invention may include: the aramid fabric 10 including warps
and wefts formed of wholly aromatic polyamide
multi fi laments ; the primary water-repellent coating layer
20 formed on the aramid fabric 10; and the secondary
water-repellent coating layer 30 formed on the primary
water-repellent coating layer 20.
FIG. 1 is a cross-sectional view illustrating the
bulletproof fabric according to the present invention.
The primary water-repellent coating layer 20 is a
resin layer containing a water-repellent agent,
preferably, fluorocarbon, and is formed using a coating
solution, which is prepared by adding the water-repellent
agent such as fluorocarbon to a resin solution in an amount
of 2 to 35 wt.% and dispersing the same therein, according
to any process of coating the aramid fabric 10 with the
coating solution through dipping, spray or knife over roll
coating, or the like, wherein the resin solution is
prepared by dissolving resin such as acrylate in a solvent.
The water-repellent agent contained in the primary
water-repellent coating layer 20 may include a variety of
water-repellent agents, however, is preferably a
fluorocarbon water-repellent agent because it enables
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water-repellent performance to be improved and retained
even in a wet state.
The secondary water-repellent coating layer 30 is a
polyurethane resin layer including micro-pores
irregularly formed therein, and is formed by a process of
coating the primary water-repellent coating layer 20 with
a polyurethane resin solution through dipping, spray or
knife over roll coating, wherein the polyurethane resin
solution is prepared by dissolving polyurethane resin in
a solvent such as dimethyl formamide.
Since the secondary water-repellent coating layer 30
includes microfine pores irregularly provided in the
coating layer, which have a size smaller than a water
droplet, penetration of the water droplets into the armaid
fabric 10 can be prevented, therefore, water-proofing
properties and water-repellent properties may be
attained simultaneously even in a wet state.
A body armor according to the present invention may
be configured using the bulletproof fabric of the present
invention, more particularly, in a laminate form obtained
by stacking up 10 to 50 sheets of the bulletproof fabrics
in such a structure that two water-repellent coating layers
20 and 30 are provided in sequential order above the aramid
fabric 10.
The bulletproof fabric of the present invention has
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such a structure that two water-repellent coating layers
20 and 30 are sequentially formed on the aramid fabric 10,
thereby accomplishing noticeable improvement in
water-repellent performance. Therefore, a body armor
manufactured using the bulletproof fabric described above
may exhibit remarkably improved bulletproof performance
in a wet state.
The body armor may have a structure of including an
aramid composite pad 40 inserted therein, as shown in FIG.
2, so as to preferably reduce rear deformation of the
bulletproof jacket to a level smaller than 44 mm as NIJ
standard, at a bulletproof performance test.
FIG. 2 is a cross-sectional view illustrating the
above- described aramid composite pad 40.
The aramid composite pad 40 may have such a structure
that a first aramid prepreg X is heat-pressed with a second
aramid prepreg Y to form an integrated laminate, wherein
the first aramid prepreg X includes a high-strength aramid
fabric A and a resin C impregnated therein while the second
aramid prepreg Y includes a high-elastic aramid fabric B
and a resin C impregnated therein, and the high-strength
aramid fabric A includes wholly aromatic polyamide
multifilaments having an overall fineness of the warps and
wefts in a range of 500 to 1,000 denier while the
high-elastic aramid fabric B includes wholly aromatic
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polyamide multifilaments having an overall fineness of the
warps and wefts in a range of 840 to 3,000 denier, thereby
preferably further reducing rear deformation of the
bulletproof jacket at a bulletproof performance test.
The aramid composite pad 40 may have a hybrid
structure of the high-strength aramid fabric A including
wholly aromatic polyamide multifilaments having an
overall fineness of the warps and wefts in a range of 500
to 1,000 denier and the high-elastic aramid fabric B
including wholly aromatic polyamide multifilaments having
an overall fineness of the warps and wefts in a range of
840 to 3,000 denier.
The resin C used herein may be properly selected
depending upon use of the aramid composite pad and, for
example, include a polyvinyl chloride resin or a phenol
resin. According to the present invention, the resin C
is not particularly limited thereto.
Both of the high-strength aramid fabric A and the
high-elastic aramid fabric B may be treated by a
water-repellent process and, as measured by ISO 4920:1981
method, may have an initial water-repellency in a range
of 90 to 100. Further, after 300 times rubbing, these
fabrics preferably have the water-repellency in a range
of 80 to 100.
In one embodiment of a method for formation of the
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..
aramid composite pad according to the present invention,
the high-strength aramid fabric A and the high-elastic
aramid fabric B may be firstly subjected to dipping in a
water-repellent agent solution, followed by padding using
a mangle, drying and/or heating, thereby completing the
water-repellent treatment.
In this case, the water-repellent agent composition
used herein may be a water-soluble solution including
hydroxylated perfluoroalkylethyl acrylate copolymer.
A particular example of the water-repellent agent
composition may be a water-repellent agent which includes:
1 to 5 wt.% water-soluble solution of a composition
containing 5 to 35 wt.% of
hydroxylated
perfluoroalkylethyl acrylate copolymer, 10 to 15 wt.% of
dipropylene glycol and 50 to 65 wt.% of water; and 0.1 to
1 wt. parts of silicon oil and 0.5 to 10 wt. parts of
isopropylalcohol relative to 100 wt. parts of the
water-soluble solution.
Next, by dipping the high-strength aramid fabric A
and the high-elastic aramid fabric B treated by the above
water-repellent process, respectively, in a bath
containing the resin C solution, a high-strength aramid
fabric A prepreg (hereinafter, referred to as a "first
prepreg") and a high-elastic aramid fabric B prepreg
(hereinafter, referred to as a "second prepreg") are
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k
prepared, respectively.
Following this, the first aramid prepreg X and the
second aramid prepreg Y are stacked up in several sheets,
followed by heat-pressing both of the laminates to form
an aramid composite pad.
Alternatively, after placing a resin film between the
high-strength aramid fabric A and the high-elastic aramid
fabric B, both of which were treated by the water-repellent
process, the above laminate may be heat-pressed to form
an aramid composite pad. In this case, the resin film is
molten, and partially impregnated into both of the
high-strength aramid fabric A and the high-elastic aramid
fabric B while partially being welded at the interface to
integrate the same.
A body armor having the aramid composite pad 40
inserted in a pocket provided at a part of the body armor
may exhibit excellent rear deformation of within a range
of 40 mm at a bulletproof performance test according to
NIJ standards.
Hereinafter, the present invention will be more
particularly understood by the following examples and
comparative examples.
However, these examples are proposed for more
concretely explaining the present invention, while not
limiting the scope of the present invention.
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Example 1
A polyacrylate resin solution containing 5 wt.% of
fluorocarbon was applied to one side of an aramid fabric
including wholly aromatic polyamide multifilaments
5 having a fineness of the warp and weft of 840 denier/840
monofilaments, in a dipping mode, to prepare a primary
water-repellent coating layer 20 having a thickness of 1.2
pm.
Next, a polyurethane solution was applied to the
10 primary water-repellent coating layer 20 through dipping,
to prepare a secondary water-repellent coating layer 30
having a thickness of 50 pm, to prepare a bulletproof
fabric.
Following this, 32 sheets of the prepared bulletproof
fabrics were stacked up and used for manufacturing a body
armor.
Physical properties of such manufactured body armor
were evaluated and results thereof are shown in Table 1.
Example 2
First, a 2.5 wt.% water-soluble solution of a
composition including 30 wt.% of hydroxylated
perfluoroalkylethyl acrylate copolymer, 15 wt.% of
dipropyleneglycol and 55 wt.% of water was prepared.
After adding 0.3 wt. part of silicon oil and 5 wt. parts
of isopropylalcohol to 100 wt. parts of the above
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water-soluble solution, the mixture was sufficiently
agitated to prepare a water-repellent agent composition.
A high-strength aramid fabric A including wholly aromatic
polyamidemultifilaments having an overall fineness of 840
denier, each of which includes 840 wholly aromatic
polyamide monofilaments having a fineness of the warp and
weft of 1.0 denier, was dipped in the above water-repellent
agent composition, followed by padding with a mangle and
drying the same, so as to form the high-strength aramid
fabric A with water-repellent properties by
water-repellent treatment.
Next, by dipping the high-strength aramid fabric A
with water-repellent properties in a phenol solution, a
high-strength aramid fabric A prepreg impregnated with
phenol resin, that is, a first aramid prepreg X was
prepared.
Meanwhile, a 2.5 wt.% water-soluble solution of a
composition including 30 wt.% of hydroxylated
perfluoroalkylethyl acrylate copolymer, 15 wt.% of
dipropyleneglycol and 55 wt.% of water was prepared again.
After adding 0.3 wt. part of silicon oil and 5 wt. parts
of isopropylalcohol to 100 wt. parts of the above
water-soluble solution, the mixture was sufficiently
agitated to prepare a water-repellent agent composition.
A high-elastic aramid fabric B including wholly aromatic
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polyamide multifilaments having an overall fineness of
1,500 denier, each of which includes 1,000 wholly aromatic
polyamide monofilaments having a fineness of the warp and
weft of 1.5 denier, was dipped in the above water-repellent
agent composition, followed by padding with a mangle and
drying the same, so as to form the high-elastic aramid
fabric B with water-repellent properties.
Next, by dipping the high-elastic aramid fabric B
with water-repellent properties in a phenol solution, a
high-elastic aramid fabric B prepreg impregnated with
phenol resin, that is, a second aramid prepreg Y was
prepared.
Subsequently, three (3) sheets of the first aramid
prepreg X and three (3) sheets of the second aramid prepreg
Y were laminated together, followed by heat-pressing the
same to form an aramid composite pad.
Following this, after forming a pocket at a part of
the body armor manufactured according to the same
procedures as described in Example 1, a sheet of the aramid
composite pad formed as described above was inserted into
the pocket.
Physical properties of the manufactured body armor
were evaluated and results thereof are shown in Table 1.
Comparative Example 1
First, a 2.5 wt.% water-soluble solution of a
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composition including 30 wt.% of hydroxylated
perfluoroalkylethyl acrylate copolymer, 15 wt.% of
dipropyleneglycol and 55 wt.% of water was prepared.
After adding 0.3 wt. part of silicon oil and 5 wt. parts
of isopropylalcohol to 100 wt. parts of the above
water-soluble solution, the mixture was sufficiently
= agitated to prepare a water-repellent agent composition.
Then, a wholly aromatic polyamide fabric refined using a
surfactant was dipped in the above water-repellent agent
composition, to impregnate the water-repellent agent
composition into the wholly aromatic fabric.
The wholly aromatic polyamide fabric used in this
example was a fabric woven in a plain form with each of
warp and weft densities of 10 threads/cm by using wholly
aromatic polyamidemultifilaments as the warps and wefts,
each of which includes 1,000 wholly aromatic polyamide
monofilaments having a fineness of 1Ø
Following this, a part of the water-repellent agent
composition impregnated in the wholly aromatic polyamide
fabric was removed, in particular, at a pick-up rate of
60%, using a mangle. Then, the treated fabric was dried
in a tenter at 150 C for 1 minute, thereby preparing a
bulletproof fabric.
Subsequently, 40 sheets of the prepared bulletproof
fabrics were stacked up to manufacture a body armor.
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Physical properties of the manufactured body armor
were evaluated and results thereof are shown in Table 1.
[TABLE 1]
Physical properties of body armor
Comparative
Items Example 1 Example 2
Example 1
Bulletproof performance
in a wet state
Not
(satisfaction of 3AV0 Satisfied Satisfied
satisfied
standards according to
NIJ)
Rear deformation of body
armor at a bulletproof 40 20 44
performance test
With regard to evaluation of the physical properties
stated in the above Table 1, bulletproof performance was
measured according to the following procedure.
Measurement of bulletproof performance
After dipping each of the prepared armaid composites
in water for 30minutes, bulletproof performance was tested
using a 44 magnum (44 mag) with a 3A grade standard
according to National Institute of Justice (NIJ),
immediately after taking out the aramid composite.
Meanwhile, on the basis of 436 m/sec, which is a bullet
speed of 44 mag, VO was measured within a range of
acceptable standards to evaluate the bulletproof
performance.
[Industrial Applicability]
According to the present invention, water-repellent
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performance is excellent to noticeably improve
bulletproof performance in a wet state. Especially, in
a case that the aramid composite pad 40 is inserted in a
pocket provided in a body armor, rear deformation of the
body armor after execution of a bulletproof performance
test is considerably reduced, therefore, the present
invention is effectively useable in manufacturing body
armor.
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