KR101155765B1 - Composite of aramid and Method for manufacturing tComposite of aramid and Method for manufacturing the same he same - Google Patents

Abstract

According to the present invention, as the resin layer made of polyurethane resin, phenol resin and polyvinyl butyral resin is coated on the aramid fiber reinforcing agent under optimum conditions, the viscoelasticity is increased, and the anti-ballistic performance is improved. The present invention relates to a composite material and a method of manufacturing the same. Aramid fibers of the present invention, the fiber reinforcing agent containing aramid fibers; And a resin layer coated on the fiber reinforcing agent, wherein the resin layer includes a polyurethane resin, a phenol resin, and a polyvinyl butyral resin.

Composite material, Aramid, Bulletproof performance

Description

Aramid composite material and its manufacturing method {Composite of aramid and Method for manufacturing the same}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aramid composite material and a method for producing the same, and more particularly, to an aramid composite material usable for bulletproof articles such as a body armor and a bulletproof helmet, and a method for manufacturing the same.

Aramid fibers include para-aramid fibers having a structure in which benzene rings are linearly connected through an amide group and meta-aramid fibers having a bent structure. Among them, para-aramid fibers have high strength, high elasticity, and the like, and thus are used as sports articles, body armor, composite materials, and the like.

Composites consist of reinforcements that serve to support external forces and matrix resins that protect these reinforcements and improve processability. In particular, composite materials including aramid reinforcing agents are being used in various fields such as aircraft, sports, and automobiles because of their excellent mechanical and thermal properties.

Composite materials containing such aramid fibers generally use a lot of phenolic resins for the matrix resin. However, phenolic resins are vulnerable to impact due to their hard properties and poor adhesion due to structural differences with aramid. When using a composite material composed of such a phenolic resin for bulletproof products such as body armor, there is a problem that the ballistic performance is poor.

Accordingly, the present invention relates to an aramid composite material and a method of manufacturing the same that can prevent the problems caused by the above limitations and disadvantages of the related art.

An advantage of the present invention is to provide an aramid composite material having excellent antiballistic performance as the viscoelasticity is increased and a method for producing the same.

Another advantage of the present invention is to provide an aramid composite material having excellent anti-ballistic performance as the aramid fiber reinforcing agent is in the optimum form and a method for producing the same.

Another advantage of the present invention is to provide an aramid composite material and a method for manufacturing the same that can reduce the production cost because the content of the coated resin layer can be lowered.

In order to achieve the above advantages, and in accordance with the object of the present invention, a fiber reinforcement comprising aramid fibers; And a resin layer coated on the fiber reinforcing agent, wherein the resin layer is provided with a composite material including a polyurethane resin, a phenol resin, and a polyvinylbutyral resin.

In another aspect of the invention, there is provided a process for preparing a fiber reinforcement comprising aramid fibers; Coating a resin on the fiber reinforcing agent to form a resin layer; And a step of molding the fiber reinforcing agent on which the resin layer is formed, wherein the resin layer is provided with a method of manufacturing a composite material including a polyurethane resin, a phenol resin, and a polyvinyl butyral resin.

According to the present invention by the above configuration has the following effects.

First, the aramid composite material according to the present invention includes a polyurethane resin, a phenol resin, and a polyvinyl butyral resin to improve the viscoelasticity when used in bulletproof products such as bulletproof helmets, body armor, etc. It works.

Second, since the aramid composite material according to the present invention is manufactured through a laminating process, the resin content can be greatly reduced, thereby reducing material costs and improving weight.

Hereinafter, the present invention will be described in detail.

First, the aramid composite material of the present invention will be described in detail.

The aramid composite material according to the present invention comprises a reinforcement comprising aramid fibers, and a resin layer coated on the fiber reinforcement.

Fiber reinforcing agent plays a role in enhancing the mechanical properties and shape stability of the composite material, and when used in bulletproof products, the fiber reinforcement should have a resistance that is not punctured against high-speed rotating ballistics. It should be made of a structure that can uniformly disperse the impact of in a short time.

The fiber reinforcing agent of the present invention includes aramid fibers that can perform such a role, the aramid fibers have excellent tensile strength and tensile modulus.

Such aramid fibers, in order to express the level of ballistic performance required in the industry, it is preferable to use filaments made of long fibers rather than spun yarn made of short fibers, measured according to the ASTM D2256 test method The tensile strength may be 15 g / d, more preferably 20 g / d or more, and the tensile modulus may be 300 g / d, more preferably 400 g / d or more. The aramid fibers may include twisted yarns (twisted yarn), non-twisted yarns, or air entangled filaments are concentrated together.

The fiber reinforcing agent may include various types of fiber reinforcing agents, such as woven fabrics, knitted fabrics, nonwoven fabrics, and uni-directional, in order to express better ballistic performance, using a unidirectional fabric made of aramid fibers arranged in one direction. It may be desirable.

The one-way fabric means a sheet-like fabric in which aramid fibers in the same layer are arranged only in one direction, and the anti-ballistic performance is better because the aramid fibers cross each other to form a warp and weft yarn and there is no intersection point. great. That is, since the fabric is bent at the intersection of the aramid fibers, the external force can be concentrated at the intersection when subjected to external impact, so that the composite material can easily rupture, while the one-way fabric is arranged side by side without the intersection By uniformly distributing the external force, it is possible to prevent the concentration of the external force, so that the composite material is not easily ruptured.

The fiber reinforcing agent may be made of a multi-layered structure in which a plurality of one-way fabric is laminated when used in bulletproof products that require better ballistic performance.

The composite material includes a resin layer coated on a fiber reinforcement to serve as a matrix. This resin layer serves to protect the fiber reinforcement from the outside and to easily mold. The resin layer may include a polyurethane resin, a phenol resin, and a polyvinylbutyral resin.

Since phenolic resin has good heat resistance, excellent electrical insulation, and rigid three-dimensional structure, the phenol resin has excellent chemical resistance and good affinity with various other materials, so that it can be applied to various fields. However, phenolic resins are easily brittle, so they have low moldability and low impact strength, and have low affinity due to structural differences with aramid fibers.

On the other hand, since the polyvinyl butyral resin has a flexible property, when used in combination with the phenol resin, it is possible to somewhat improve the easily broken properties of the phenol resin. However, even when a mixture of polyvinyl butyral resin and phenol resin is used, since flexibility is not greatly improved, external impact cannot be smoothly and uniformly dispersed, and thus there is a limit in improving ballistic performance of bulletproof products.

Since the polyurethane resin has a flexible molecular structure, it has excellent viscoelasticity and can smoothly and uniformly disperse external impacts.

As such, the resin layer in which a phenol resin having excellent mechanical properties and a polyurethane resin having excellent viscoelasticity is mixed with a polyvinyl butyral resin having excellent flexibility and adhesiveness can smoothly and uniformly disperse external impact.

Therefore, a composite material including a resin layer including a polyurethane resin, a phenol resin, and a polyvinyl butyral resin exhibits excellent ballistic resistance when used in a bulletproof article such as a body armor.

The polyurethane resin may be included in an amount of 5 to 60% by weight relative to the resin layer. If the content of the polyurethane resin is less than 5% by weight, the viscoelasticity may not be greatly increased, and thus the antiballistic performance of the composite material may not be improved. On the other hand, when the content of the polyurethane resin is more than 60% by weight, the mechanical properties Because of this, the ballistic resistance of the composite material may be lowered.

The polyurethane resin may be thermoplastic, and may be a homo polymer or copolymer.

It may be preferable that the resin layer is included in the composite material in 10 to 25% by weight. When the content of the resin layer is less than 10% by weight, the resin layer may not concentrate the fiber reinforcement sufficiently, so the durability and the ballistic resistance of the composite material may be reduced, whereas when the content of the resin layer exceeds 25% by weight of the fiber As the content of the reinforcing agent is lowered, the antiballistic performance of the composite material may be degraded.

Hereinafter, a method of manufacturing a composite material according to an embodiment of the present invention will be described. Detailed description of the same parts, such as the fiber reinforcing agent, the resin layer of the above-described composite material will be omitted.

First, a fiber reinforcement agent containing aramid fibers is produced.

The aramid fibers were polymerized with para-phenylenediamine and terephthaloyl dichloride in a polymerization solvent to prepare a poly paraphenylene terephthalamide polymer, and then the polymer was dissolved in concentrated sulfuric acid solvent to prepare a spinning dope, and spinning The dope may be prepared by spinning through a spinneret and then solidifying. Aramid fibers produced through such a process may have a tensile strength of 20g / d or more and an elastic modulus of 400g / d or more.

The fiber reinforcing agent may include various forms such as woven fabrics, knitted fabrics, unidirectional fabrics, and the like, which may be prepared by conventional methods, and in order to obtain excellent ballistic performance as described above, it is preferable to use unidirectional fabrics.

The one-way fabric, through the process of inserting the aramid fibers wound bobbin in the krill according to the required width, unwinding the aramid fibers from the bobbins, using a comb device so that the aramid fibers are arranged side by side at regular intervals It can manufacture. At this time, the maritime tension may be used by using a tension adjusting device to maintain the tension of the loose aramid fibers uniformly.

On the other hand, the one-way fabrication process and the formation process of the resin layer to be described later can be carried out continuously in the same apparatus.

Next, a resin composition to be coated on the fiber reinforcement is prepared.

The resin composition may be a liquid phase and may be a solid phase such as a film, which is prepared by conventional methods. That is, the resin composition of the liquid phase may be prepared by mixing and dissolving the above-mentioned resins in an organic solvent, and the resin composition of the film may be prepared by uniformly mixing with each other and then casting or blowing.

In addition, the process of manufacturing the said fiber reinforcing agent, and the process of preparing the said resin composition do not have a special process sequence.

Next, a process of forming a resin layer is performed by coating the resin composition on the fiber reinforcing agent prepared as described above.

The process of forming the resin layer may be performed through various methods, for example, it may be performed through a dipping process or a laminating process.

The dipping process may be performed by immersing a fiber reinforcing agent in a solution in which a polyurethane resin, a phenol resin, and a polyvinyl butyral resin are mixed, followed by drying. Such an immersion process is suitable for mass production due to its simple process, but it is difficult to uniformly control the content of the resin layer, so that the variation in the ballistic performance of the composite material is not only large, but also the weight decreases due to excessive use of the resin. There is this. The composite material prepared through the dipping process may have a low flexibility of the fiber reinforcement as the resin having good fluidity impregnates the whole fiber reinforcement, and the mechanical properties of the fiber reinforcement may decrease as the resin penetrates into the fiber reinforcement. Can be. Therefore, the composite material produced through such an immersion process does not significantly improve the ballistic performance when used in bulletproof articles such as body armor.

The laminating process may be performed by attaching a film mixed with a polyurethane, a phenol resin, and a polyvinyl butyral resin to a fiber reinforcing agent, and then coating the film under pressure. In this case, the laminating process may be performed in a state in which heat is applied to easily impregnate the resin between the fiber reinforcing agents.

Accordingly, when the resin layer is formed through the laminating process, the resin layer may be uniformly coated on the entire fiber reinforcement, and the content of the components constituting the resin layer may be precisely controlled. The composite material prepared through the laminating process does not significantly degrade the flexibility and mechanical properties of the fiber reinforcement because the resin layer is strongly attached only to the surface of the fiber reinforcement. Therefore, the composite material produced through the laminating process, such as when used in bulletproof articles, bulletproof helmets, bulletproof helmets, etc. will exhibit excellent weight and bulletproof performance.

It may be preferable that the fiber reinforcing agent in which the resin layer is formed through the process of forming the resin layer is a prepreg in a semi-cured state without being completely cured.

Next, the process of shape | molding the fiber reinforcement in which the resin layer was formed is performed. That is, the prepreg of the semi-hardened state manufactured in the above process is put in the mold which has a predetermined shape, and can be hardened | cured in the state which applied the pressure, and the molded product can be obtained. The mold has a predetermined shape corresponding to the shape of the product.

In order for the molding process to be easily performed, the prepreg inserted into the mold is preferably in a state where hardening does not proceed much. It cannot be manufactured smoothly.

The molding process may be performed in a state where a pressure of 50 to 500 bar is applied, and it is preferable to select an appropriate pressure in consideration of the thickness of the product, the characteristics of the resin layer, and the like.

On the other hand, the molding process may be carried out in a state where a temperature of 20 to 180 ℃ is given, preferably may be carried out in a temperature range of 60 to 150 ℃. The temperature may be selected in consideration of the type and content of the resin constituting the resin layer.

In addition, the molding process may be carried out for 1 minute to 2 hours at the appropriate pressure and temperature described above, preferably in the range of 10 minutes to 1 hour.

The molding process may be performed including a lamination process. That is, the composite material may be manufactured through a molding process of laminating and curing the prepregs of the semi-cured state in an appropriate number of sheets according to the required bulletproof performance and the product. In the lamination process, the respective prepregs in the semi-cured state can be oriented at a predetermined angle with respect to each other. It may be desirable.

Hereinafter, the present invention will be described in detail through Examples and Comparative Examples. However, the following examples are only intended to help the understanding of the present invention, and the scope of the present invention should not be limited.

Example  One

Para-phenylenediamine and terephthaloyl dichloride were polymerized in an N-methyl-2-pyrrolidone polymerization solvent to prepare a poly paraphenylene terephthalamide polymer, which was then dissolved in concentrated sulfuric acid solvent to spin dope. Was prepared, and the spinning dope was spun through a spinneret and then solidified to prepare 1,000 denier aramid fibers.

The prepared aramid fibers were placed in a krill and the aramid fibers were released from the krill and passed through a tension control device and a combing bar to prepare a sheet-shaped unidirectional fiber reinforcement. Thereafter, the resin composition solution was continuously applied onto the sheet-shaped one-way fiber reinforcing agent to form a resin layer, and then dried to prepare a one-way aramid prepreg by winding the wound roll. At this time, the resin layer was mixed with 40% by weight of polyurethane resin, 50% by weight of phenol resin, and 10% by weight of polyvinyl butyral resin.

The one-way aramid prepregs were cut to a predetermined length, and 17 pieces of the cut prepregs were laminated on a mold and cured in a pressurized state to prepare an aramid composite material. At this time, the pressing and curing process was performed for 30 minutes at a pressure of 210 bar, a temperature of 115 ℃.

Example  2

In Example 1 described above, the aramid composite material was prepared in the same manner as in Example 1 except that the resin composition in the film state was used instead of the resin composition in the liquid state. At this time, the film was supplied onto the unidirectional fiber reinforcement through a separate film supply device.

Example  3

In Example 1 described above, the aramid composite was prepared in the same manner as in Example 1 except that the fiber reinforcing agent in the form of a fabric instead of the unidirectional fiber reinforcing agent. Here, the fabric reinforcing agent in the form of the fabric was prepared through the process of applying the prepared aramid fibers to warp and weft yarn and weaving into plain weave.

Example  4

In Example 1 described above, the aramid composite material was prepared in the same manner as in Example 1, except that the fiber type reinforcing agent was used instead of the one-way fiber reinforcing agent, and the resin composition in the film state was used instead of the liquid resin composition. It was.

Comparative example  One

In Example 1 described above, the aramid composite material was obtained in the same manner as in Example 1, except that a resin composition solution consisting only of a phenol resin was used instead of a resin composition solution mixed with a polyurethane resin, a phenol resin, and a polyvinyl butyral resin. Was prepared.

Comparative example  2

In Example 1 described above, the aramid composite was prepared in the same manner as in Example 1, except that a resin composition consisting only of a polyurethane resin was used instead of a resin composition mixed with a polyurethane resin, a phenol resin, and a polyvinyl butyral resin. The material was prepared.

Comparative example  3

In Example 1 described above, except that a resin composition consisting of 75% by weight of phenol resin and 25% by weight of polybutyral resin was used instead of a resin composition mixed with a polyurethane resin, a phenol resin, and a polyvinyl butyral resin. An aramid composite was prepared in the same manner as in Example 1.

Comparative example  4

In Example 1 described above, a resin composition consisting only of a phenol resin was used instead of a resin composition mixed with a polyurethane resin, a phenol resin, and a polyvinyl butyral resin, and a fiber reinforcing agent in the form of a fabric was used instead of a unidirectional fiber reinforcing agent. Prepared an aramid composite material in the same manner as in Example 1.

The physical properties of the composite materials prepared by Examples and Comparative Examples were measured by the following method and are shown in Table 1 below.

Bulletproof performance V50 )

Each sample was measured for ballistic performance at V50 (m / s), the average speed between full penetration and partial penetration with Cal.22 caliber debris simulation (FSP) according to MIL-STD-662F.

division Process type Resin layer content
(weight%) Bulletproof performance
(V50 (m / s)) Example 1 One Direction + Dipping Process 22 620 Example 2 One-way + film 18 660 Example 3 Fabric + Dipping Process 22 550 Example 4 Fabric + Film 18 600 Comparative Example 1 One-way + Dipping (Phenol) 22 520 Comparative Example 2 One-way + dip (PU) 22 560 Comparative Example 3 One-way + Dipping (Phenol + PVB) 22 550 Comparative Example 4 Fabric + Dipping (Phenol) 22 490

Claims (8)

Fiber reinforcements including aramid fibers; And Including a resin layer coated on the fiber reinforcement, The resin layer contains a polyurethane resin, a phenol resin, and a polyvinylbutyral resin, The polyurethane resin is a composite material, characterized in that 5 to 60% by weight relative to the resin layer. The method of claim 1, The resin layer is a composite material, characterized in that consisting of 10 to 25% by weight of the composite material. delete The method of claim 1, The fiber reinforcement is a uni-directional fiber reinforcement formed by arranging the aramid fibers in one direction. Preparing a fiber reinforcement agent comprising aramid fibers; Coating a resin on the fiber reinforcing agent to form a resin layer; And Including the step of molding the fiber reinforcing agent formed resin layer, The resin layer comprises a polyurethane resin, a phenol resin, and a polyvinylbutyral resin, The polyurethane resin is a method for producing a composite material, characterized in that 5 to 60% by weight relative to the resin layer. The method of claim 5, The process of forming the resin layer is a method for producing a composite material, characterized in that carried out through a laminating process. The method of claim 5, The process of manufacturing the fiber reinforcing agent is a method for producing a composite material, characterized in that it comprises a step of producing a one-way fiber fabric in which aramid fibers are arranged in one direction. The method of claim 5, The molding process includes the step of laminating a plurality of the fiber reinforcement having the resin layer formed in a predetermined number of sheets.