KR101174958B1 - Method for manufacturing of aramid prepreg and aramid steel composite - Google Patents

Abstract

Disclosed are a method for producing aramid prepreg and a method for producing an aramid steel sheet composite material, which can maintain the antiballistic performance of the level required in the industry for a long time and do not significantly reduce the adhesion even under a large impact. The method for producing aramid prepreg of the present invention comprises the steps of: impregnating a resin in the aramid fabric; And pretreating one surface of the resin-impregnated aramid fabric. In addition, the method for producing an aramid steel sheet composite of the present invention, the step of laminating and curing the aramid prepreg to prepare an aramid composite; Preparing a steel sheet; And adhering the aramid composite material and the steel sheet to each other using an adhesive medium, wherein at least one of preparing the aramid composite material and preparing the steel sheet includes pretreatment. It includes a method for producing an aramid steel sheet composite material.

Pretreatment stage, aramid steel sheet composite, bulletproof performance

Description

Manufacturing Method of Aramid Prepreg and Manufacturing Method of Aramid Steel Sheet Composite {Method for manufacturing of aramid prepreg and aramid steel composite}

The present invention relates to a method for producing aramid prepreg and aramid steel sheet composite material, and more specifically, to provide a ballistic performance of the level required in the industry for a long time, the adhesion performance of the aramid prepreg that does not significantly decrease even under a large impact A manufacturing method and a manufacturing method of an aramid steel plate composite material.

Bulletproof products are products for protecting the human body from bullets and shells, and the bulletproof performance of bulletproof products depends greatly on the materials used.

In particular, bulletproof products used in vehicles require materials with better bulletproof performance in order to safely report the human body from a great danger such as external shells.

Accordingly, conventionally, a vehicle body has been constructed and manufactured mainly using steel sheets having excellent ballistic resistance.

 However, the steel sheet has excellent ballistic performance while the specific gravity is very high, increasing the weight of the vehicle, reducing the maneuverability, thereby increasing the risk of exposure to the risk, and increase the use of fuel to reduce the efficiency of the operation.

On the other hand, bulletproof products using high-strength plastic or high-strength fiber is very lightweight, but the bulletproof performance is less than the steel sheet is not enough to protect the human body from external dangers.

Therefore, in order to reduce the weight of the bulletproof product, a dissimilar material composite using a steel sheet as a front material and a fiber reinforced composite as a back material is used.

However, such a dissimilar material composite has a low adhesive strength due to the use of materials having different properties, and when exposed to the external environment for a long time or when subjected to a large physical shock, the adhesive strength is significantly lowered and the ballistic performance is degraded.

Accordingly, in order to improve the adhesion between the steel sheet and the fiber-reinforced composite, although an adhesive medium having excellent adhesion is used, there is a limit in improving the adhesion between dissimilar materials having different properties.

Therefore, the present invention relates to a method for producing aramid prepreg and a method for producing an aramid steel sheet composite which can prevent the problems caused by the above limitations and disadvantages of the related art.

An advantage of the present invention is to provide a method for producing an aramid prepreg and a method for producing an aramid steel sheet composite, which can maintain the level of antiballistic performance required in the industry for a long time, and does not significantly degrade the adhesive performance even under a large impact.

In order to achieve the above advantages, and in accordance with the object of the present invention, impregnating a resin in the aramid fabric; And pretreating a surface of the aramid fabric impregnated with the resin.

In another aspect of the invention, the step of laminating and curing the aramid prepreg to prepare an aramid composite; Preparing a steel sheet; And adhering the aramid composite material and the steel sheet to each other using an adhesive medium, wherein at least one of preparing the aramid composite material and preparing the steel sheet includes pretreatment. A method for producing an aramid steel sheet composite is provided.

According to the present invention, the aramid prepreg pretreated on the surface provides excellent adhesive strength when adhering with other materials, and the aramid steel sheet composite prepared by mutual bonding after pretreatment can not only maintain bulletproof performance for a long time due to excellent adhesive strength. Bulletproof performance is not greatly reduced even under a large impact.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Therefore, the present invention encompasses all changes and modifications that come within the scope of the invention as defined in the appended claims and equivalents thereof.

The term 'aramid prepreg' as used herein refers to an aramid composite material in which an aramid fabric is impregnated with a resin, which means that the impregnated resin is not completely cured but is in a prepreg state.

As used herein, the term "aramid composite material" refers to an aramid composite material made by laminating and curing the aramid prepregs in several layers, and may include the following aramid laminate.

As used herein, the term "aramid laminate" refers to a composite material prior to completion of the aramid composite, and refers to a form in which several layers of aramid fabric are laminated and bonded to each other.

As used herein, the term 'aramid steel sheet composite' refers to an aramid composite material including an aramid fabric including a resin and a steel sheet to which the steel sheet is bonded by an adhesive medium.

Hereinafter, with reference to the accompanying drawings will be described in detail a specific embodiment of the method for producing the aramid prepreg 10 and the aramid steel sheet composite according to the present invention.

1 and 2 schematically illustrate a cross section of an aramid prepreg 10 according to an embodiment of the invention.

As shown in Fig. 1, the aramid prepreg 10 of the present invention is aramid fabric 11, the resin 12 impregnated in the aramid fabric 11 and the resin-impregnated aramid fabric surface It includes the active layer 13 formed.

In addition, as shown in Figure 2, the aramid prepreg (10) of the present invention, the aramid fabric 11, the resin 12 impregnated in the aramid fabric 11, the aramid fabric impregnated with the resin It may include an active layer 13 formed on the surface and a binder layer 14 formed on the active layer 13.

The aramid fabric 11 can be produced by applying conventional aramid filaments to warp and weft yarns and weaving.

The process of impregnating the resin in the aramid fabric 11 may be performed by a coating (coating) or a dipping (dipping) process, etc. Among these, the dipping process will be described in detail.

First, the resin 12 is dissolved in a solvent such as methyl ethyl ketone or methanol, and an additive is mixed therein to prepare a resin composition for impregnation. Thereafter, the aramid fabric 11 is immersed in the resin composition, and the solvent is evaporated using an oven to complete the aramid fabric impregnated with the semi-cured resin.

The active layer 13 formed on one surface of the resin-impregnated aramid fabric can be produced by the pretreatment process described below. The pretreatment process may be performed by a corona discharge treatment process or a flame treatment process.

In the corona discharge state, sufficient hot electrons are supplied from the cathode, and a large current flows because the potential difference between the negative and positive poles is lowered, and the cathode and the anode are made of plasma. At this time, the temperature is about 3,000 to 6,000 ° C., in particular, because the temperature near the anode is very high, a part of the electrode material is evaporated to become a light source of continuous spectrum.

The light source in the corona discharge state is used to activate the surface of the resin-impregnated aramid fabric. The surface of the aramid fabric having the active layer 13 has a large number of active groups such as carboxyl groups, amine groups, and hydroxyl groups, which are hydrophilic groups. Thus, the aramid prepreg 10 having a plurality of active groups is easily bonded with other materials such as other prepregs or steel sheet 20 to provide excellent interfacial adhesion strength.

The corona discharge treatment process may be performed under the following process conditions.

In the air at room temperature and normal pressure, a high alternating voltage is applied between the two electrodes to induce corona discharge, and the sample is placed between the two electrodes to treat the surface of the sample. At this time, the applied AC voltage is 1,000 ~ 50,000V, the treatment time is preferably 1 ~ 60 minutes. If the AC voltage is too high or the processing time is too long, the surface of the sample may be damaged and the physical properties may be deteriorated. On the other hand, if the AC voltage is too low or the processing time is too short, the desired activation effect may be obtained. Can't expect

In addition, the pretreatment process of the present invention may be carried out by a flame treatment process. The flame treatment process activates the surface of the aramid fabric by treating the surface of the resin-impregnated aramid fabric with a flame. As described above, the aramid fabric surface having the active layer 13 has a large number of active groups such as carboxyl groups, amine groups, and hydroxyl groups, which are hydrophilic groups. Thus, the aramid prepreg 10 having a plurality of active groups is easily bonded with other materials such as other prepregs or steel sheet 20 to provide excellent interfacial adhesion strength.

The flame treatment process may be carried out under the following process conditions.

Through the flame nozzle, a mixed gas of natural gas and air is introduced to make a flame, and the surface of the sample is treated by using the flame. At this time, it is preferable that the distance of a sample from a flame end is 1-10 mm, and processing time is 0.1-30 minutes. If the distance of the sample from the flame end is too close or the treatment time is too long, the surface of the sample may be carbonized, thereby deteriorating physical properties. On the other hand, if the distance of the sample from the flame end is too long or the treatment time is short. You can not expect the desired degree of activation effect.

As shown in FIG. 2, the aramid prepreg 10 of the present invention may include a binder layer 14 on the active layer 13 formed on the resin-impregnated aramid fabric surface.

The process of forming the binder layer 14 may be performed by various methods, and typically, an aramid fabric containing the active layer 13 is immersed in a binder solution made by dissolving a coupling agent in an alcohol solvent. The drying may be performed through a dipping process.

The concentration of the binder in such a binder solution may be 0.01 to 5.0% by weight. If the concentration of the binder is less than 0.01% by weight, the aramid prepreg 10 that does not sufficiently provide the binder to the surface of the active layer 13, and thus does not have sufficient binder on the surface, may be replaced with another prepreg or steel sheet 20. It may not have good adhesive strength by insufficient chemical bonding with the back. On the other hand, when the concentration of the binder exceeds 5.0% by weight, since the binder is sufficiently formed on the surface of the active layer 13, the improvement in adhesive strength is not great and the binder is wasted.

The binder may be a silane-based or titanium-based binder that is excellent in heat resistance and can greatly improve the bonding strength with the steel sheet 20.

Thus, a plurality of active groups are introduced to the surface of the aramid impregnated with resin through a corona discharge or flame treatment process, which is a pretreatment process, and the hydroxyl groups of the activator and the binder are chemically bonded through a dehydration reaction. The binder which is chemically bonded to such an active group has a different hydroxyl group, and the other hydroxyl group can greatly improve adhesion by chemically bonding to a reactor of a heterogeneous material such as another prepreg or steel sheet 20.

Figure 3 schematically shows the cross section of the aramid steel sheet composite according to an embodiment of the present invention. As shown in FIG. 3, the aramid steel sheet composite material of the present invention includes an aramid composite material 40, an adhesive layer 30, and a steel sheet 20.

First, the aramid composite 40 may be prepared by stacking and curing the aramid prepreg 10.

The prepregs 10 may be a prepreg including an active layer 13 as shown in FIG. 1, may be a prepreg including a binder layer 14 formed on the active layer 13 as shown in FIG. 2, Ordinary prepreg, i.e., aramid fabric impregnated with resin, may be used.

The aramid composite 40 can be prepared by the method described below.

A step of preparing the aramid prepreg 10, the step of laminating the aramid prepreg 10 in a plurality of layers according to the use, and the step of pressing the laminate in a high temperature state sequentially.

Optionally, when the active layer 13 formed on the top surface of the laminate does not have sufficient active groups, the above-described pretreatment process, corona discharge or flame treatment may be further performed.

In addition, when the binder layer 14 formed on the top layer surface of the laminate does not have sufficient binder, the above-described binder treatment process may be further performed.

That is, after laminating the aramid prepreg 10 after the pretreatment process or the pretreatment process and the binder treatment process and press molding, the pretreatment process may be further performed, or the pretreatment process and the binder treatment process may be further performed. 40) can be prepared. Alternatively, after the pretreatment process or the pretreatment process and the binder treatment process, that is, laminating the aramid prepreg 10 that does not include the active layer 13 or the binder layer 14 and press-molded, performing a pretreatment process, or The aramid composite 40 may be prepared by performing a pretreatment process and a binder treatment process.

Typically, the aramid steel sheet composite used in bulletproof vehicles, etc., the adhesive strength between the aramid composite material 40 and the steel sheet 20 is lower than the adhesive strength between the resin-impregnated aramid fabrics. Therefore, the adhesive strength at the level required by the industry may be achieved only by performing the pretreatment process and the binder treatment process in the aramid composite 40 manufacturing process without performing the pretreatment process and the binder treatment process in the aramid prepreg 10 manufacturing process. Bulletproof performance can be obtained.

Next, the process of preparing the steel sheet 20 will be described.

The steel sheet 20 has a very different property from the aramid composite 40 which is a kind of organic polymer. For this reason, when bonding the steel plate 20 and the aramid fabric 11, it is difficult to obtain sufficient adhesive strength.

Thus, similar to using the aramid composite 40 including the active layer 13 or the active layer 13 and the binder layer 14, the active layer 13, or the active layer 13 and the binder layer 14 The steel plate 20 containing it can be used.

The method of applying the active layer 13 to the steel sheet 20 may be performed through the pretreatment process as described above.

Meanwhile, the process of applying the binder to the surface of the steel sheet 20 may be performed by using a spray method, a coating method, or a dipping method.

Next, the manufacturing method of the said aramid steel plate composite material is demonstrated. Aramid steel sheet composite manufacturing method, the step of manufacturing the aramid composite material 40, preparing a steel sheet 20, and the step of adhering the aramid composite material 40 and the steel sheet 20 to each other using an adhesive medium Include.

The step of preparing the aramid composite 40 and the step of preparing the steel sheet 20 has already been described above. Accordingly, a process of adhering the aramid composite material 40 and the steel sheet 20 to each other using an adhesive medium will be described.

The adhesive medium may use an adhesive in a composition state or an adhesive film. The adhesive may use a polysulfide adhesive, and the adhesive film may use a polyvinyl alcohol film. When the polyvinyl alcohol adhesive medium in the form of film is used, uniform adhesive strength can be obtained. On the other hand, the polysulfide adhesive can provide a good adhesive strength even when bonded at room temperature.

The process of adhering the aramid composite material 40 and the steel sheet 20 to each other using an adhesive medium comprises the steps of: inserting an adhesive medium between the steel sheet 20 and the aramid composite material 40 and a pressure of 800 psi or more. It is completed by performing the step of gluing under sequential order.

The aramid steel sheet composite produced by the above-described method, after performing a peel test under conditions of a load cell of 100 kgf and a speed of 300 mm / min, to have an excellent adhesive strength of 3.0 kgf / 5 cm or more do.

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.

1) Aramid Prepreg Manufacture

Example  One

Aramid fabric 11 having a density of 450 g / m 2 was prepared by applying ordinary 3,000 denier wholly aromatic aramid filaments to warp and weft yarns, respectively, and weaving them into plain weave.

Next, the aramid fabric 11 was immersed in a resin composition prepared by dissolving the phenol resin in a methanol solvent, and then the methanol solvent was removed to obtain an aramid fabric having a content of 20% of the phenol resin.

Thereafter, the aramid prepreg 10 having the active layer 13 was prepared by performing a pretreatment process using a corona discharge treatment device on the surface of the aramid fabric impregnated with the resin 12. The corona discharge process at this time was carried out in the air at room temperature, atmospheric pressure, a voltage of 10,000V, a frequency of 60 Hz and a treatment time of 20 minutes.

Example  2

In Example 1 described above, in order to form the binder layer 14 on the active layer 13, the aramid prepreg (10) having the active layer 13 to 2% by weight of 3-glycidoxypropyl trimeth Aramid prepreg 10 was prepared in the same manner as in Example 1 except for adding a binder treatment step consisting of a step of immersion in a 3-glycidoxylpropyltrimethoxysilane methanol solution and drying.

Example  3

In Example 1 described above, the aramid prepreg 10 was prepared in the same manner as in Example 1, except that a flame treatment apparatus was used instead of the corona discharge treatment apparatus in the pretreatment process. At this time, the flame treatment process was a mixed gas having a volume ratio of natural gas and air of 1: 1, the distance from the flame end to the sample was 5 mm and the treatment time was carried out in a state of 5 minutes.

Example  4

In Example 3 described above, in order to form the binder layer 14 on the active layer 13, the aramid prepreg (10) having the active layer 13, 2% by weight of 3-glycidoxypropylpropylmeth Aramid prepreg 10 was prepared in the same manner as in Example 1 except for adding a binder treatment step consisting of a step of immersion in a 3-glycidoxylpropyltrimethoxysilane methanol solution and drying.

Comparative example  One

In Example 1, the aramid prepreg 10 was prepared by the same method as Example 1, except that the pretreatment process was not performed.

Adhesive strength of each of the aramid prepregs 10 prepared by Examples and Comparative Examples was measured by the following method, the results are shown in Table 1.

Aramid Prepreg (10)  Adhesion Strength Measurement

Two aramid prepregs (10) prepared by the above Examples and Comparative Examples were laminated and bonded to each other while maintaining a pressure of 1200psi and a temperature of 150 ℃ to make a sample. Using the sample, the adhesive strength (gf / 5 cm) between the prepregs was measured by a peel test at a load cell of 1 kgf and a speed of 300 mm / min in accordance with ASTM D903.

division Active layer presence Binder layer Adhesive strength (gf / 5 ㎝) Example 1 U radish 350 Example 2 U U 450 Example 3 U radish 320 Example 4 U U 430 Comparative Example 1 radish radish 150

2) Preparation of Aramid Steel Sheet Composite

Example  5

15 aramid prepregs 10 prepared by the above-described embodiment 1 were laminated in order so that the active layer 13 in the same direction and then press-molded under a pressure of 1200psi and a temperature of 150 ℃ to form the aramid composite 40 Prepared.

On the other hand, a steel sheet 20 having a thickness of 4.8 mm having an average surface roughness of 30 μm was prepared.

After applying the polysulfide adhesive on the steel sheet 20, the aramid composite 40 is seated on the adhesive so that the active layer 13 faces the adhesive, and then bonded for 1 hour at a temperature of 50 ℃, 1000psi Aramid steel sheet composite was prepared.

Example  6

In Example 5 described above, an aramid steel sheet composite was prepared in the same manner as in Example 5 except for using the aramid prepreg 10 prepared in Example 2.

Example  7

In Example 5 described above, an aramid steel sheet composite material was prepared in the same manner as in Example 5 except for using the aramid prepreg 10 prepared in Example 3.

Example  8

In Example 5 described above, an aramid steel sheet composite material was manufactured by the same method as Example 5 except for using the aramid prepreg 10 prepared in Example 4.

Example  9

The aramid prepreg (10) prepared by Comparative Example 1 was laminated in 15 sheets and then press-molded under a pressure of 1200psi and a temperature of 150 ℃ to prepare an aramid laminate. As in Example 1, the aramid composite 40 having the active layer 13 was prepared by performing a pretreatment process using a corona discharge treatment device on the surface of the aramid laminate.

Aramid steel sheet composite material was prepared in the same manner as in Example 5, except that the aramid composite material 40 was used.

Example  10

In Example 9 described above, except that the aramid laminate having the active layer 13 was used, the aramid composite 40 having the binder layer 14 prepared by performing the binder treatment process in the same manner as in Example 2 was used. Prepared an aramid steel sheet composite material in the same manner as in Example 9.

Example  11

In Example 9 described above, Example 9 was used except that the aramid composite material 40 having the active layer 13 prepared by performing a pretreatment process using a flame treatment device instead of a corona discharge treatment device on the surface of the aramid laminate. Aramid steel sheet composite was prepared by the same method as.

Example  12

In Example 10 described above, Example 10 was used except that the aramid composite material 40 having the active layer 13 prepared by performing a pretreatment process using a flame treatment device instead of a corona discharge treatment device on the surface of the aramid laminate. Aramid steel sheet composite was prepared by the same method as.

Example  13

In Example 5 described above, an aramid steel sheet composite material was manufactured by the same method as Example 5 except for using the steel sheet 20 manufactured by performing a pretreatment process using a corona discharge treatment apparatus.

Example  14

In Example 5 described above, an aramid steel sheet composite material was manufactured by the same method as Example 5 except for using the steel sheet 20 manufactured by performing a pretreatment process using a flame treatment apparatus.

Example  15

In Example 13 described above, the same method as Example 13 was used except that the steel sheet 20 manufactured by performing the process of treating the binder using the same process as in Example 2 was used. The aramid steel sheet composite was produced.

Example  16

In Example 14 described above, the same method as Example 14 was used except that the steel sheet 20 manufactured by performing the process of treating the binder using the same process as in Example 2 was used. The aramid steel sheet composite was produced.

Comparative example  2

In Example 5 described above, an aramid steel sheet composite material was prepared by the same method as Example 5 except for using the aramid prepreg 10 prepared in Comparative Example 1.

The adhesive strength of each aramid steel sheet composite prepared by the Examples and Comparative Examples was measured by the following method, the results are shown in Table 2.

Measurement of Adhesion Strength (㎏f / 5㎝) of Aramid Steel Sheet Composite

According to ASTM D903, the adhesive strength (kgf / 5cm) between the steel sheet and the aramid composite was measured by a peel test at a load cell of 100 kgf and a speed of 300 mm / min.

division Prepreg pretreatment Prepreg adhesive treatment Lamination Pretreatment Laminate adhesive treatment Pre-treatment of steel sheet Steel sheet adhesive treatment Adhesive strength (㎏f / 5㎝) Example 5 U radish radish radish radish radish 3.0 Example 6 U U radish radish radish radish 3.5 Example 7 U radish radish radish radish radish 3.1 Example 8 U U radish radish radish radish 3.3 Example 9 radish radish U radish radish radish 4.5 Example 10 radish radish U U radish radish 5.6 Example 11 radish radish U radish radish radish 4.3 Example 12 radish radish U U radish radish 5.2 Example 13 U radish radish radish U radish 3.9 Example 14 U radish radish radish U radish 3.7 Example 15 U radish radish radish U U 4.2 Example 16 U radish radish radish U U 4.0 Comparative Example 2 radish radish radish radish radish radish 2.0

1 is a schematic cross-sectional view of an aramid prepreg according to an embodiment of the present invention.

2 schematically illustrates a cross section of an aramid prepreg according to another embodiment of the present invention.

Figure 3 schematically shows the cross section of the aramid steel sheet composite according to an embodiment of the present invention.

Description of the Related Art [0002]

10: aramid prepreg 11: aramid fabric

12: resin 13: active layer

14: binder layer

20: steel sheet 30: adhesive layer

40: Aramid Composite

Claims (10)

Dipping the aramid fabric in a resin composition containing an organic solvent and a resin dissolved in the organic solvent; Removing the organic solvent so that the aramid fabric is present in the semi-cured resin; And A method for producing aramid prepreg comprising the step of pre-treating the surface of the semi-cured resin. The method of claim 1, The pretreatment step comprises the steps of treating the corona discharge (corona discharge). 3. The method of claim 2, The step of treating the corona discharge is a method for producing aramid prepreg, characterized in that the AC voltage is 1000 ~ 50,000V, the processing time is carried out in a state of 1 to 60 minutes. The method of claim 1, The pretreatment step comprises the step of treating the flame method of producing aramid prepreg. 5. The method of claim 4, The step of treating the flame is carried out within a range of making the flame by injecting a mixed gas of natural gas and air through the flame nozzle, the distance from the flame end to the sample is 1 ~ 10㎜ and the treatment time is 0.1 ~ 30 minutes Method for producing aramid prepreg, characterized in that the. The method of claim 1, After the pretreatment, further comprising the step of treating the surface of the pretreated resin with a binder, The binder is a method for producing aramid prepreg, characterized in that the silane-based or titanium-based binder. Aramid prepreg of any one of claims 1 to 6 laminated and cured to prepare an aramid composite; Preparing a steel sheet; And Including the step of adhering the aramid composite material and the steel sheet to each other using an adhesive medium, And before the bonding step, pre-treating at least one of the adhesive surface of the aramid composite to be bonded to the steel sheet and the adhesive surface of the steel sheet to be bonded to the aramid composite. The method of claim 7, wherein The pretreatment step includes a corona discharge treatment step, wherein the corona discharge treatment step of the aramid steel sheet composite material is characterized in that the AC voltage is performed in the range of 1000 ~ 50,000V and processing time 1 ~ 60 minutes Manufacturing method. The method of claim 7, wherein The pretreatment step includes a flame treatment step, wherein the flame treatment step is performed by injecting a mixed gas of natural gas and air through a flame nozzle to make a flame, and a distance from the flame end to a sample is 1 to 10 mm and a treatment time. The method for producing an aramid steel sheet composite, characterized in that performed in the range of 0.1 to 30 minutes. The method of claim 7, wherein Between the pretreatment of the adhesive surface and the bonding step, the method of producing an aramid steel sheet composite further comprising the step of treating the adhesive surface of the aramid composite and the pre-treated adhesive surface of the adhesive surface of the steel sheet with a binder. .

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