KR101967476B1 - Meta aramid paper with enhanced Tear strength - Google Patents

Abstract

The present invention relates to a meta-aramid paper having excellent strength, and has an advantage of providing an excellent elongation and a breaking load.
Further, the meta-aramid paper having excellent strength of the present invention as described above and the meta-aramid sheet made of the meta-aramid paper have thinness and excellent elongation, so that they can be used for products requiring slimming, A meta-aramid paper having an excellent elongation showing a breaking load superior to that of a meta-aramid produced by the method of the present invention.

Description

Meta aramid paper with enhanced tear strength < RTI ID = 0.0 >

The present invention relates to a meta-aramid paper having excellent strength, and more particularly, to a meta-aramid paper having an excellent strength capable of providing a strength and a cutting load higher than that of a conventional meta-aramid paper.

Generally, polyamide-based synthetic resins are classified into aliphatic polyamides and aromatic polyamides. Aliphatic polyamides are generally known under the trade name Nylon, and aromatic polyamides are known under the trade name Aramid. Among the aliphatic polyamides, nylon 6 and nylon 6,6 are the most common thermoplastic engineering plastics, and they are used not only as fibers but also as molding materials in various fields. The nylon resin used in the molding industry is made of reinforced plastics which is reinforced with mineral or glass fiber to improve mechanical properties such as elasticity and lowering the price to have improved flame retardancy and impact resistance.

Aromatic polyamides, developed in the 1960s, were developed to improve the heat resistance of nylon, an aliphatic polyamide. Aromatic polyamides, well known for their trade names such as Nomex and Kevlar, And has excellent heat resistance and high tensile strength which can be used for fibers such as cord. A typical aliphatic polyamide is a synthetic resin having an aliphatic hydrocarbon bonded between amide groups, and an aramid is a synthetic resin having an amide bond having 85% of benzene groups bonded to two aromatic rings between amide groups. The aliphatic hydrocarbon of the aliphatic polyamide easily undergoes molecular motion when heat is applied, whereas the benzene ring of the aromatic polyamide is stable to heat and has a high elastic modulus because the molecular chain is rigid and molecules do not easily move even when heat is applied. And there are many differences in characteristics.

The aromatic polyamides are classified into para-aramid and meta-aramid. The para-aramid is represented by Kevlar developed by DuPont. The para-aramid is the benzene ring bound to the amide group at the para position. Since the molecular chain is very stiff and has a linear structure, it has a very high strength and a particularly high elasticity, so that it has excellent shock absorbing performance. It is used for armor, bulletproof helmet, safety gloves, boots and fire extinguisher. It is used for sports equipment such as sticks, fishing rods and golf clubs, and also for industrial use such as FRP (Fiber Reinforced Plastic) and asbestos replacement fibers. The meta-aramid is a combination of benzene ring and amide group at the meta position. Its strength and elongation are similar to ordinary nylon, but it has very good heat stability. It is light and sweat-absorbing compared to other heat-resistant materials. have. In the early days, the color was limited to a few, but recently it has been made in various colors including fluorescent colors. It is used as fire-resistant clothing, uniforms for racing motorists, astronaut uniforms, work clothes, etc., and for industrial use, it is used for high-temperature filters.

Generally, meta-aramid paper is made by mixing meta-aramid flock with meta-aramid fibrid at a certain ratio.

However, although the meta-aramid flocs acted as a binder for the meta-aramid fibrids, there was a problem that the meta-aramid flocs tangled with each other or aggregated to deteriorate the physical properties of the meta-aramid paper.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a meta-aramid paper having excellent strength, which improves the physical properties of the paper by preventing the meta-aramid flakes from entangling or aggregating, .

In order to solve the above-mentioned problems, the present invention provides a meta-aramid fabric layer; And a meta-aramid fibrid layer formed on at least one side of the fabric layer.

According to a preferred embodiment of the present invention, the meta-aramid fabric layer may include meta-aramid fibers, and the meta-aramid fibers may be 1.1 to 2.6 D (denier).

According to a preferred embodiment of the present invention, the meta-aramid fabric layer may be woven in a plain weave shape, and the average pore size of the meta-aramid fabric layer may be 5 to 200 탆. The thickness of the meta-aramid fabric layer may range from 30 to 300 [mu] m.

According to a preferred embodiment of the present invention, the meta-aramid fibrid layer included in the meta-aramid fibrid layer may have a width of 15 to 50 μm and a length of 0.1 to 3 mm, and the thickness of the meta- To 200 [mu] m.

Another aspect of the present invention is a meta-aramid paper comprising a meta-aramid fabric layer, wherein when the thickness of the meta-aramid paper is 200 탆 or less, a meta-aramid paper having a breaking load of 1250 mN or more and an elongation of 3% or more can be provided .

Another aspect of the present invention provides a meta-aramid sheet made from the meta-aramid paper.

The meta-aramid paper having excellent strength of the present invention can be used for a product which is thin and has excellent strength and is required to be slim.

Also, it is possible to provide a meta-aramid paper having excellent strength showing a breaking load superior to that of the meta-aramid produced by the prior art.

1 is a cross-sectional view of a meta-aramid paper according to an embodiment of the present invention.
2 is a cross-sectional view of a meta-aramid paper according to another embodiment of the present invention.
3 is a top view of the meta-aramid fabric layer of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in more detail with reference to the accompanying drawings.

As described above, the conventional meta-aramid paper produced meta-aramid flock and meta-aramid fibrid at a constant mixing ratio. However, when the meta-aramid flocs serve as a binder, meta-aramid flocs are entangled with each other, There was a problem that the physical properties of the aramid paper were lowered.

Thus, according to one aspect of the present invention, a meta-aramid fabric layer; And

And a meta-aramid fibrid layer formed on at least one side of the fabric layer, thereby solving the above-mentioned problem. Accordingly, the meta-aramid paper of the present invention has a thin thickness and excellent strength and breaking load It can be used for products that require slimming.

1 is a cross-sectional view of a meta-aramid paper according to an embodiment of the present invention. In the meta-aramid paper 100, a meta-aramid fibrid layer 110 is formed on one side of the meta-aramid fabric layer 120.

First, the meta-aramid fabric layer 120 will be described.

In the present invention, the fabric of the meta-aramid fabric layer may be poly (metaphenylene isophthalamide), 4,4-diaminodiphenyl sulfone, or 3,3-diaminodiphenyl sulfone polymer as raw materials. I do not.

The polymer can be a polyamide in which at least 85% of the amide (-CO-NH-) bonds are attached directly to the two aromatic rings, and additives can be used together, and as many as 10% Can be blended with an aramid. Copolymers having as many as 10% of other diamines replacing the diamine of the aramid or as many as 10% other diacids replacing the diacid chlorides of the aramid may be used. In some of the most preferred embodiments, the meta-aramid polymer may be a poly (metaphenylene isophthalamide).

The meta-aramid fabric layer of the present invention has a high physical property when the meta-aramid flock is mixed with the paper and the meta-aramid flock is mixed with the meta-aramid flock. This is because the meta-aramid fibrids serve as binders for holding the meta-aramid flocs rather than using only meta-aramid fibrids, thereby increasing the physical properties. Therefore, the conventional paper made the paper by mixing the two raw materials with the meta-aramid flock and the meta-aramid fibrid. Although the strength can be increased, since the meta-aramid flocs are scattered randomly, When the paper is produced using the meta-aramid fabric of the present invention, it is possible to produce a meta-aramid paper superior to conventional methacrylamide flock and meta-aramid fibrid paper. Therefore, the meta-aramid paper of the present invention is superior to the conventional one.

FIG. 3 is a plan view of the meta-aramid fabric layer of the present invention. According to a preferred embodiment of the present invention, the meta-aramid fabric layer may include meta-aramid staple fibers.

The meta-aramid fibers of the present invention may be 1.1 to 2.6 D (denier). If the staple fiber is less than 1.1D, there is a problem in making the fabric. If the staple fiber is more than 2.6D, the thickness of the paper is too thick, so that it is difficult to produce thin paper.

According to a preferred embodiment of the present invention, the meta-aramid fabric layer may be woven in a plain weave shape or may be woven in various other forms.

However, if the meta-aramid fabric layer is woven in a plain weave shape, it may be most preferable since it is thin, highly rigid and strong because it has many tissue points, and can be practically used and various changed fabrics can be obtained.

In the present invention, the average pore size formed in the meta-aramid fabric layer means the space between the lattices when weaving the fabric with fibers. That is, the space between the weft and the warp of the fabric. Also, in the case of a paper made only of meta-aramid fibrids, the average pore size may mean the space between meta-aramid fibrids.

If the average pore size of the fabric layer is less than 5 탆, the porosity may be too low, and when the average pore size of the fabric layer is more than 200 탆, There may be a problem with strength because of this.

According to a preferred embodiment of the present invention, the thickness of the meta-aramid fabric layer may range from 30 to 100 탆. If the thickness is less than 30 탆, it may be difficult to produce a fabric. There may be a problem.

Next, the meta-aramid fibrid layer 110 will be described.

In the meta-aramid fibrid layer in the present invention, the fibrids are derived from the fiber-film hybrid, meaning a very fine polymer product of a small filmy or irregular fibrous particles, and the shape varies greatly depending on processing conditions. Such processing conditions lead to various forms and rheological morphology of the fibrids from the foam form to the fibrous form, and therefore, how to select the fibrid preparation conditions can have a very important influence on the physical properties of the paper. The meta-aramid forming the meta-aramid fibrid layer may be poly (metaphenylene isophthalamide), 4,4-diaminodiphenylsulfone, 3,3-diaminodiphenylsulfone, but is not limited thereto.

The film-like fibrids can be fibrous or fibrous fibrids and can be very finely divided meta-aramid polymer products of two-dimensional particles, usually up to 0.1 to 3 mm in length and 15 to 50 μm in width.

The fibrids can be prepared by streaming a polymer solution into a coagulating bath of a liquid that is immiscible with the solvent of the solution. The stream of polymer solution is subjected to intense shear and turbulence as the polymer coagulates.

Meta-aramid polymers suitable for use in the meta-aramid fibrid layer may be polyamides in which at least 85% of the amide (-CO-NH-) bonds are attached directly to the two aromatic rings, As many as many weight percent of the other polymeric materials can be blended with the meta-aramid. Copolymers having as many as 10% of other diamines replacing the diamine of the aramid or as many as 10% other diacids replacing the diacid chlorides of the aramid may be used. In some of the most preferred embodiments, the meta-aramid polymer may be a poly (metaphenylene isophthalamide).

The meta-aramid fibrid layer 110 of the present invention serves as an average pore control.

The meta-aramid fibrids included in the meta-aramid fibrid layer may have a width of from 15 to 50 μm and a length of from 0.1 to 3 mm. If the width is less than 15 μm and the length is less than 0.1 mm, If the width exceeds 50 탆, pore control is difficult, and if the length exceeds 3 mm, the meta aramid fibrids may be entangled or aggregated, which may cause a problem of paper aggregation.

The meta-aramid fibrid layer of the present invention can produce a meta-aramid fibrid layer by compressing meta-aramid fibrids. Preferably, the meta-aramid fibrid layer is rolled into a meta-aramid fibrid layer by a calender .

According to a preferred embodiment of the present invention, the thickness of the meta-aramid fibril layer may be 5 to 300 m, and if the thickness of the fibrid layer is less than 5 m, it may be too thin to form a phaser. If it is more than 300 mu m, there may be a problem that the thickness is too high and the average porosity is low.

FIG. 2 is a cross-sectional view of a meta-aramid paper according to another embodiment of the present invention. In the meta-aramid paper 100, a meta-aramid fibrid layer 110 is formed on both sides of a meta-aramid fabric layer 120.

The meta-aramid fibrid layer is included on the cross-section or on both sides of the meta-aramid fabric layer, with differences in porosity, strength, and flatness. Such differences can be found in FIGS. 1 and 2.

On the other hand, the meta-aramid paper of the present invention can form a meta-aramid fibrid layer on a cross-section or both sides with the meta-aramid fabric layer as a center, but the meta-aramid fabric layer and the meta-aramid fibrid layer are not necessarily in contact with each other . That is, even if another type of layer is further formed between the meta-aramid fabric layer and the meta-aramid fibrid layer, they are included in the scope of the present invention.

Further, the meta-aramid paper comprising the meta-aramid fabric layer and the fibrid layer of the present invention can be compressed to produce a meta-aramid paper. Preferably, the meta-aramid paper is rolled into a calender to produce a meta-aramid paper. have.

On the other hand, the conventional meta-aramid paper has a thickness It was difficult to satisfy both of the two physical properties at a cutting load of 1250 mN or more and an elongation of 3% or more at the same time. Therefore, the conventional meta-aramid paper has a problem that the elongation and breaking load are poor.

According to another aspect of the present invention, there is provided a meta-aramid paper having a breaking load of 1250 mN or more and an elongation of 3% or more when the thickness of the meta-aramid paper is 200 m or less. Accordingly, the present invention can satisfy both of the two physical properties at a cutting load of 1250 mN or more and an elongation of 3% or more when the thickness is 200 mu m or less. Thereby, it is possible to provide a meta-aramid paper having superior physical properties.

As a result, the meta-aramid paper of the present invention is not manufactured by mixing flock and fibrids, which are the conventional manufacturing methods, but is made by forming a meta-aramid staple fiber as a fabric and forming a meta-aramid fabric layer; And a meta-aramid fibrid layer formed on at least one side of the fabric layer, thereby providing a meta-aramid paper having improved physical properties compared to the prior art. Thus, meta-aramid paper produced by the meta- An aramid sheet can be provided. According to another aspect of the present invention, there is provided a meta-aramid sheet made of the meta-aramid paper.

The meta-aramid paper manufactured according to the present invention is widely used in electric insulating materials and honeycomb panel applications. Electric insulating materials include a generator, a transformer, a microwave oven HVT, a battery pack for a mobile phone, a reactor Spark Plug Leads Shield, Wire Cladding and Speaker Voice Coil. Honeycomb Panel is used for aircraft tail fins, engine nacelle, Helicopter blades and interior materials, interior materials for railway vehicles, automobile chassis, boat bodies, and architectural interior materials, and can be used as separator paper.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples should not be construed as limiting the scope of the present invention, and should be construed to facilitate understanding of the present invention.

[ Example ]

Example 1

A meta-aramid fabric layer was produced by weaving meta-aramid fibers with a fineness of 1.5 denier. The fabric layer was fabricated with an average pore size of 50 ㎛ and a thickness of 120 ㎛. And width A meta-aramid fibrid layer having a thickness of 20 mu m and a thickness of 30 mu m and a length of 1.5 mm was rolled with a calender to produce a fibrid meta-aramide layer. Then, the meta-aramid fibrid layer was rolled and adhered to the cross section of the prepared meta-aramid fabric layer with a calender to make a 128-μm thick meta-aramid paper.

Example  2

The meta-aramid paper was prepared in the same manner as in Example 1 except that the values in Table 1 were met.

Example  3

A meta-aramid paper was prepared in the same manner as in Example 1 except that the numerical values were satisfied in Table 1.

Example  4

A meta-aramid paper was prepared in the same manner as in Example 1 except that the numerical values were satisfied in Table 1.

Meta-aramid fabric layer Meta-aramid fibrid layer Paper Denia
(D) Average pore size
(탆) thickness
(탆) width
(탆) Length
(Mm) thickness
(탆) thickness
(탆) Example 1 1.1 25 80 30 1.5 20 90 Example 2 1.5 50 120 30 1.5 20 128 Example 3 2.0 90 160 30 1.5 20 170 Example 4 2.6 130 200 30 1.5 20 200

Comparative Example 1

50: 50 weight ratio of meta-aramid flock (1.5 denier, length of 5 to 7 mm) and meta-aramid fibrid (fiber length of 1.5 mm, fiber width of 30 탆) were mixed and rolled with a calender to obtain a meta- Aramid paper.

[ Experimental Example ]

Experimental Example  One

In Examples 1 to 4 And the meta-aramid paper prepared in Comparative Example 1 were tested for elongation and breaking load in a L & W tensile strength tester. The results are shown in Table 2 below.

Thickness, ㎛ Elongation,% Tear Strength, mN Example 1 90 3.1 1254.2 Example 2 128 3.9 1852.3 Example 3 170 4.2 2410.3 Example 4 200 5 2631.5 Comparative Example 1 128 2.2 1111.8

As a result of measurement, Examples 1 to 4 exhibited excellent elongation and breaking load while being thin, and Comparative Example 1 showed a thin thickness but significantly reduced elongation and breaking load. In particular, in Example 3, since the fabric layer having a fineness of 2 denier is formed, it can be seen that the meta-aramid paper having the highest strength, elongation, and cutting load is manufactured.

100: meta-aramid paper 110: meta-aramid fibrid layer
120: Meta-aramid fabric layer

Claims (10)

A meta-aramid fabric layer comprising meta-aramid fibers of 1.1 to 2.6 D (denier); And
And a meta-aramid fibrid layer formed on at least one side of the fabric layer. delete delete The method according to claim 1,
Wherein the meta-aramid fabric layer is woven in a plain weave. 5. The method of claim 4,
Wherein the meta-aramid fabric layer has an average pore size of from 5 to 200 m. The method according to claim 1,
Wherein the meta-aramid fabric layer has a thickness of 30 to 300 占 퐉. The method according to claim 1,
Wherein the meta-aramid fibrid layer has a thickness of 5 to 200 占 퐉. The method of claim 1, wherein
Wherein the meta-aramid fibrids contained in the meta-aramid fibrid layer have a width of 15 to 50 탆 and a length of 0.1 to 3 mm. A meta-aramid paper comprising a meta-aramid fabric layer comprising meta-aramid fibers of 1.1 to 2.6 D (denier)
The thickness of the meta-aramid paper A meta-aramid paper having a breaking load of 1250 mN or more and an elongation of 3% or more when the thickness is 200 mu m or less. A meta-aramid sheet produced from the meta-aramid paper of any one of claims 1 to 9.

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