KR20110103634A - A manufacturing method of mat-plastic composite containing clay particles - Google Patents

Abstract

Method for producing a mat-plastic composite containing clay particles of the present invention comprises the steps of (S1) preparing a mat formed of pellets and fibers in which the clay particles are dispersed in a thermoplastic compound; (S2) impregnating the melt melt the pellet into the mat; (S3) preparing a mat prepreg impregnated with a polymer resin by heating the resultant of the step (S2) to polymerize the thermoplastic compound into a thermoplastic polymer resin; And (S4) heat-molding the mat prepreg impregnated with the polymer resin into a predetermined shape.
According to the production method of the present invention can be mass-produced by the thermoforming process, it is possible to obtain a plastic composite excellent in mechanical properties. The mat-plastic composite prepared according to the present invention is useful as parts of automobiles or aircrafts.

Description

A manufacturing method of mat-plastic composite containing clay particles

The present invention relates to a plastic composite that can be usefully used as parts of automobiles and aircraft by replacing metals.

  Recently, research and development for replacing metal materials using plastic composite materials has been steadily progressing.

Metal materials are excellent materials in terms of heat resistance and mechanical strength, and are currently used in many fields such as automobiles, aircrafts, and construction. However, metal materials have a disadvantage of being heavy because of their high specific gravity. On the other hand, since plastics have a low specific gravity, there is an advantage that a product of the same size can be manufactured several times lighter than metal, and efforts are being made to use it as a substitute for metal materials. In particular, the recent high oil prices are driving the auto and aircraft industries to this end.

Plastics known to date are very difficult to achieve performance comparable to metals. Thus, attempts have been made to replace metals by combining plastics with other materials to realize the form of composite materials. The most commonly used composite materials include thermoset plastic composites. The thermosetting plastic composite material is prepared by dispersing carbon fiber or glass fiber in a thermosetting resin such as epoxy resin and then partially curing it to prepare a prepreg. do. The advantage of such a thermosetting plastic composite is that once it is cured, its heat resistance and mechanical properties are very good. On the other hand, there is a limitation in the shape of the product because it is manufactured using a sheet-shaped prepreg, there is a disadvantage in that productivity is reduced and recycling is not performed because the heat curing process.

Other forms of plastic composites include thermoplastic composites. Since the thermoplastic composite is used by mixing short glass fibers or carbon fibers with a thermoplastic resin that can be injected or extruded, various types of products can be processed and recycled. On the other hand, when the fiber content is increased, the melt viscosity is rapidly increased and the workability is inferior, and there is a problem in that the fiber content in the composite cannot be increased. .

The technical problem to be achieved by the present invention is to overcome the shortcomings of the conventional thermosetting and thermoplastic composites, to provide a method of manufacturing a thermoplastic composite that can be easily replaced by a metal material with excellent mechanical strength and easy thermoforming processing. .

Method for producing a mat-plastic composite containing clay particles of the present invention comprises the steps of (S1) preparing a mat formed of pellets and fibers in which the clay particles are dispersed in a thermoplastic compound; (S2) impregnating the melt melt the pellet into the mat; (S3) preparing a mat prepreg impregnated with a polymer resin by heating the resultant of the step (S2) to polymerize the thermoplastic compound into a thermoplastic polymer resin; And (S4) heat-molding the mat prepreg impregnated with the polymer resin into a predetermined shape.

In the production method of the present invention, the content of the clay particles is preferably less than 10 wt% based on the total weight of the thermoplastic compound.

In the manufacturing method of this invention, the said thermoplastic compound can use cyclic butylene terephthalate and caprolactam individually or in mixture of these, respectively.

According to the manufacturing method of the present invention, it is possible to mass-produce without a thermosetting process, such as the existing thermosetting plastic composite, it is possible to provide a thermoplastic composite having excellent mechanical properties.

Plastic composite obtained according to the present invention is excellent in mechanical properties and can be reduced by 50% or more compared to steel, it can be applied to the production of high-performance components such as automobiles and aircraft.

1 is a view schematically showing a process of manufacturing a mat prepreg impregnated with a polymer resin according to the production method of the present invention,
FIG. 2 is a view schematically illustrating a process of heating a mat prepreg impregnated with a polymer resin.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated.

According to the method for producing a mat-plastic composite containing clay particles of the present invention, first, a mat formed of pellets and fibers in which clay particles are dispersed in a thermoplastic compound is prepared (step S1).

The present invention, unlike the conventional plastic composite for the high mechanical strength is used not to produce fibers in the form of mats but short fibers. That is, the mat is formed of high-strength fibers such as glass fiber or carbon fiber. The mat formed of the fiber can realize high mechanical properties because the fibers are arranged in a certain direction, and the various types of mats such as weave and biax can be used to optimize the properties according to the shape of the part to be manufactured. have.

On the other hand, the thermoplastic compound used in the present invention is used in the form before polymerization into a polymer to facilitate penetration and impregnation between the fibers constituting the mat. This is because the melt viscosity of the polymer is so large that it is very difficult to impregnate between the fibers. The thermoplastic compound is usually in the form of a powder at room temperature, but when melted by heating, it is obtained as a melt having high fluidity. Resin materials having such characteristics include CBT (Cyclic Butylene Terephthalate) and Caprolactam, and CBT becomes PBT through polymerization, and Caprolactam becomes Polyamide (Nylon resin) through polymerization. Both PBT and Polyamide are widely used engineering plastics because of their excellent heat resistance and mechanical strength. The thermoplastic compound that can be used in the present invention is not limited to CBT or Caprolactam, and other thermoplastic compounds having a low melt viscosity can also be used.

In the present invention, a pellet in which clay particles are dispersed in such a thermoplastic compound is used. Clay particles serve to further improve the mechanical properties of the finally formed plastic composite. In the production method of the present invention, the content of the clay particles is preferably less than 10 wt% based on the total weight of the thermoplastic compound. In addition, the pellets may be added a catalyst for the polymerization reaction described later, a pigment for controlling the color, and the like.

Subsequently, the melt in which the pellets are melted is impregnated into the mat (step S2). Since the thermoplastic compound has a low melt viscosity as described above, the melt in which the pellet is melted is easily penetrated between the fibers constituting the mat.

Then, the resultant of step (S2) is heated to polymerize the thermoplastic compound to a thermoplastic polymer resin to prepare a mat prepreg impregnated with a polymer resin (step S3). When the mat prepreg impregnated with the polymer resin thus prepared is heated and molded into a predetermined shape, a mat-plastic composite molded article having a desired shape can be obtained. Using the method used in the present invention, it is also possible to prepare high-performance composites having a very high fiber content with a fiber content of 45-65 vol.%.

 An embodiment of the above-described manufacturing method of the present invention will be described with reference to the drawings.

First, the mat is prepared by determining the shape, thickness, and structure of the mat suitable for the intended use. The pellet 2 is evenly applied on the mat layer 1 thus constructed. This pellet is a pellet in which nano-sized clay particles, catalysts, additives, etc. are uniformly dispersed in CBT, for example. Subsequently, the resultant is heat treated to evenly impregnate the mat with melting pellets. The heat treatment is then continued to induce the polymerization of the thermoplastic compound. At this time, the heat treatment and polymerization temperature may be performed between 150 degrees and 210 degrees. Through this process, a mat prepreg 3 impregnated with a thermoplastic polymer resin is manufactured (FIG. 1).

The thus prepared mat prepreg can be manufactured into a component of a desired shape by a thermoforming process. The prepreg (3) prepared as shown in Figure 2 is heated through a heater (4) and then inserted into a mold (5) having a desired shape to produce a part (6) by pressing. Such a thermoforming process is a process that cannot be applied to a conventional thermosetting plastic composite, and is a technical feature that enables the mass production of the thermoplastic composite of the present invention.

Hereinafter, a specific method of the present invention will be described with reference to Examples, but the scope of the present invention is not limited to these Examples.

Example 1

 Functional mat layers were first constructed for product manufacture. Glass mats were constructed to have a four-layer structure of weave (0/90 degrees) + biax (+ 45 / -45 degrees) + biax (+ 45 / -45 degrees) + weave (0/90 degrees). Then, evenly disperse and blend the CBT (Cyclics) resin containing 0.5 mol% of the catalyst and 6 wt% of nanoclay (manufactured by Nanocor) to prepare in pellet form. The resin mixture was evenly coated on a glass mat, followed by heat treatment at 190 ° for 10 minutes for impregnation and polymerization. In this case, TiO 4 was used for the purpose of inducing a polymerization reaction. The thickness of the prepared thermoplastic composite was 1.3 mm, the content of Glass fiber Mat was 55 vol%. The composite prepreg thus prepared was preheated at 240 ° C. and then inserted into a thermoforming mold to prepare a product by pressing at a pressure of 3 atm.

On the other hand, the specific strength (value divided by the density) physical properties of the thermoplastic composite thus prepared is compared with other materials as shown in Table 1 below.

Nasal strength
(σ / ρ: MPa) Tensile strength
(MPa) Density (g / cm ³ ) GF 55vol.% Complex 238 428 1.8 Nylon 69 78 1.13 PP 37 33 0.9 GF35% / Nylon 120 192 1.6 steal 42 346 8.3 aluminum 115 312 2.7

Example 2

 The specimens were prepared in the same manner as in the examples except that the specimens having 35, 45, and 65 vol% were prepared to compare the physical property change according to the content of the glass fiber mat. Tensile tests were carried out for physical property evaluation, and were carried out by ASTM D3039. The measurement results are as follows.

Glass fiber content (vol.%) Tensile strength (MPa) Tensile modulus (GPa) 35 168 13.8 45 267 16.3 55 428 20 65 485 23

Example 3

In order to compare the change of physical properties according to the content of the polymerization catalyst, the specimens were prepared by changing the catalyst contents to 0.3, 0.5, and 0.7 mol%, respectively. The manufacturing method was manufactured by the same method as the method shown in the Example. At this time, the glass fiber content was prepared by fixing to 55vol.%.

Tensile tests were carried out for physical property evaluation, and were carried out by ASTM D3039. The measurement results are as follows.

Catalyst content (mol.%) Tensile strength (MPa) Tensile modulus (GPa) 0.3 219 15.8 0.5 428 20 0.7 307 17

Claims (3)

(S1) preparing a mat formed of pellets and fibers in which clay particles are dispersed in a thermoplastic compound;
(S2) impregnating the melt melt the pellet into the mat;
(S3) preparing a mat prepreg impregnated with a polymer resin by heating the resultant of the step (S2) to polymerize the thermoplastic compound into a thermoplastic polymer resin; And
(S4) comprising the step of heat-forming the mat prepreg impregnated with the polymer resin into a predetermined shape,
Method for producing a mat-plastic composite containing clay particles. The method of claim 1, wherein the content of the clay particles is less than 10 wt% based on the total weight of the thermoplastic compound. The method of claim 1, wherein the thermoplastic compound is any one selected from the group consisting of cyclic butylene terephthalate, caprolactam, and mixtures thereof.

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