JP2009019089A - Fiber-reinforced plastic and reinforced heat-insulating composite material using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-weight fiber-reinforced plastic being excellent in strength, heat-insulating properties, water resistance and torsion strength, while reducing the usage of an expensive reinforcing fiber, and to provide a reinforced heat-insulating composite material for a cold insulation container by using the plastic. <P>SOLUTION: The fiber-reinforced plastic is obtained by impregnating a reinforcing fiber material 2 with a binder resin 3 mixed with a reinforcing filler 4, and curing the resultant product. The reinforced heat-insulating composite material is obtained by nipping both side surfaces of a sheet-shaped or plate-shaped foam material 7 with a pair of the fiber-reinforced materials 2 impregnated with the binder resin 3 mixed with the reinforcing filler 4, and compressing the foam material 7 so as to be formed into a thickness for the wall material of the cold insulation container. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fiber reinforced plastic obtained by infiltrating a binder resin into a reinforced fiber and cured, and a reinforced heat insulating composite material obtained by laminating the fiber reinforced plastic and a foamed material. The present invention relates to a suitable reinforced heat insulating composite material.

  Conventionally, since fiber reinforced plastic has characteristics such as high strength, light weight, and corrosion resistance, it has been used in various fields such as vehicle bodies, tennis racket frames, and bath tubs. In addition, composite materials that combine fiber reinforced plastics with other substances and take advantage of each other's properties have been proposed.

  For example, in a cold insulated container that is mounted on a trailer or the like and transports food such as fresh food, a heat insulating composite material in which fiber reinforced plastic and a wooden board are bonded together with an adhesive is generally used as a wall material.

  However, a composite material of fiber reinforced plastic and wood used as a wall material of a conventional cold container has a problem that the weight of the vehicle increases by several tens of kg when used for several years because the wood easily absorbs moisture. is there. In other words, if freezing and thawing are repeated in the cold container, the water at the time of thawing is absorbed by the wall material and the vehicle weight increases. For this reason, there is a problem that it takes a considerable amount of time until moisture is removed, and it is easily corroded. In recent years, it has become a problem that cannot be overlooked in the situation where the occurrence of a traffic accident due to an excess of the load of the load is regarded as a problem. Moreover, when the weight increases, the disadvantage of deterioration in fuel consumption for long-distance transportation is large.

  On the other hand, in Japanese Patent Application Laid-Open No. 2005-289056, an impact-resistant fiber reinforced by laminating two or more layers having different flexural moduli by adjusting the type of reinforcing fiber, the type of resin, and the thickness thereof. A multilayer structure in which ceramics or metal is bonded to plastic and this impact-resistant fiber reinforced plastic has been proposed (Patent Document 1). According to Patent Document 1, for example, a high bending elastic modulus layer is laminated on the collision surface side of a high-speed flying object, so that it can be used for a light bulletproof vest, a helmet, an aircraft, etc. having excellent impact resistance. Yes.

  Japanese Patent Application Laid-Open No. 2004-314561 is formed by laminating a fiber reinforced plastic before being completely cured and a thermosetting resin mixed with a balloon-like polyimide, and curing them by heating at one time. A method of manufacturing a composite material has been proposed (Patent Document 2). According to this Patent Document 2, since a balloon-shaped polyimide air layer is formed in the resin, it is said to have excellent heat insulation.

JP 2005-289056 A JP 2004-314561 A

  However, in the invention described in Patent Document 1, since two or more layers having different flexural moduli are combined, it is difficult to adjust and manufacture them, and the manufacturing cost increases. In addition, the product is distorted due to differences in time, temperature, and shrinkage until each layer is completely cured, and there is also a problem that it is difficult to provide a product with a constant quality.

  In the invention described in Patent Document 2, since the specific gravity difference between the balloon-shaped polyimide and the resin is large, the balloon-shaped polyimide is likely to float during heating, and it is difficult to uniformly distribute the balloon-shaped polyimide. Therefore, the distribution may be biased, or the thermal characteristics such as thermal conductivity and the strength characteristics such as tensile strong elastic modulus may be biased.

  The present invention has been made to solve such problems, and is a lightweight fiber excellent in strength, heat insulation, water resistance, and torsional strength while suppressing the use of expensive reinforcing fibers. An object of the present invention is to provide a reinforced heat insulating composite material for a wall material of a reinforced plastic and a cold container using the reinforced plastic.

  The feature of the fiber reinforced plastic according to the present invention is that the binder resin in which the reinforcing filler is mixed into the reinforcing fiber material is infiltrated and cured.

  In addition, the feature of the reinforced heat insulating composite material according to the present invention is that the binder resin mixed with the reinforcing filler is infiltrated into the sheet-like or plate-like reinforcing fiber material, and at least one surface is laminated and cured. In the point.

  Furthermore, the feature of the reinforced heat insulating composite material according to the present invention is that the foamed material in the form of a sheet is sandwiched between a pair of reinforcing fiber materials infiltrated with a binder resin mixed with a reinforcing filler, and the foamed The material is compressed and formed into a thickness for the wall material of the cold storage container.

  The term “penetration” as used in the present invention refers to the case where the binder resin mixed with the reinforcing filler penetrates between the reinforcing fiber materials, that is, between the reinforcing fibers.

  According to the present invention, while suppressing the use of expensive reinforcing fibers, it is possible to inexpensively manufacture lightweight wall materials and the like that are excellent in strength, heat insulation, torsion resistance, and water resistance. When used, the product life can be extended and fuel efficiency and transportation costs can be reduced.

  Hereinafter, a first embodiment of a fiber reinforced plastic according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a fiber reinforced plastic 1 in the first embodiment.

  As shown in FIG. 1, the fiber reinforced plastic 1 according to the first embodiment includes a reinforced fiber material 2, a binder resin 3 mixed with a reinforced filler 4, and a coating material 5 that coats the surface of the fiber reinforced plastic 1. It consists of and.

  The reinforcing fiber material 2 is used as a reinforcing material, and general reinforcing fibers such as glass fiber, carbon fiber, and aramid fiber are used. In addition, in this embodiment, although a nonwoven fabric is used, it is good also as a woven fabric and it is good also as a three-dimensional shape with the thickness which laminated | stacked them.

  The binder resin 3 is a main material of the fiber reinforced plastic 1 and functions as a curing material by infiltrating and curing between the reinforcing fiber materials 2 and in the fibers. The fiber reinforced plastic 1 is constituted by performing the function of bonding. As the binder resin 3 in the first embodiment, an unsaturated polyester resin that is cured when it comes into contact with air is used. However, the present invention is not limited to this, and an epoxy resin or the like may be used. Alternatively, a multi-component resin that cures by mixing more than that may be used.

  The reinforcing filler 4 mixed in the binder resin 3 is a powdery or short fiber material suitable for strengthening the physical properties of the binder resin 3, for example, a carbon powder having an appropriate particle size. , Powders such as metal powders, ceramics powders, and plastic powders, or short fibers such as carbon, metal, glass fibers, and plastic fibers. In this embodiment, a non-uniform powdery and short fiber carbon material generated in the previous stage of forming a carbon fiber having a predetermined length is used. The reinforcing filler 4 is mixed with the binder resin 3 and cured together, so that it can maintain an appropriate bending elastic modulus and bending strength without using the long-fiber reinforcing fiber material 2, and can resist torsion. Yield strength can be improved.

  When the binder resin 3 mixed with the reinforcing filler 4 is permeated into the reinforcing fiber material 2, it is applied to the sheet-like reinforcing fiber material 2 with a brush or the like, or conversely, the gel-like or liquid binder resin 3 is put into the container. What is necessary is just to infiltrate by putting and dipping the reinforcing fiber material 2.

  For example, when the carbon filler 41 is used as the reinforcing filler 4 mixed in the binder resin 3, the carbon filler 41 is mixed so that the weight ratio with the binder resin 3 is 1: 100 to 3: 100. It is preferable. Further, it is desirable that the reinforcing filler 4 is uniformly distributed in the binder resin 3, so that the carbon filler 41 is mixed in a predetermined amount about 10 times, and further stirred for about 30 minutes and then strengthened. It is preferable to penetrate the fiber material 2.

  The coating material 5 is for smoothening the surface of the fiber reinforced plastic 1 so that the fiber reinforced plastic 1 is not easily damaged and maintaining a good appearance. In the first embodiment, after the fiber reinforced plastic 1 is completely cured, a coating resin is applied to the surface thereof.

  Next, the operation of the first embodiment will be described.

  The fiber reinforced plastic 1 according to the first embodiment is considered to effectively act on the binding force between the binder resin 3 and the reinforcing fiber material 2 by mixing the reinforcing filler 4 into the binder resin 3. Compared with fiber reinforced plastic 1 that does not contain, the tensile modulus, tensile strength, and tensile elongation at break, while maintaining the same or higher strength, the flexural modulus and bending strength are reduced, and the durability against twisting is reduced. Increase. Therefore, when used for a member that is susceptible to vibration or impact during transportation, such as a cold container, it exhibits effective durability.

  According to the first embodiment as described above, it is possible to obtain an inexpensive and high-strength material while reducing the amount of the reinforcing fiber material 2 by mixing the reinforcing filler 4 into the binder resin 3. Further, it is possible to adjust characteristics such as strength by adjusting the type, particle size, mixing amount, and the like of the reinforcing filler 4.

  Next, a second embodiment of the reinforced heat insulating composite material according to the present invention will be described with reference to the drawings. FIG. 2 is a perspective view of the reinforced heat insulating composite material 6 in the second embodiment. In addition, the same code | symbol is attached | subjected about the structure which is the same as that of 1st Embodiment mentioned above among the structures of this 2nd Embodiment, or equivalent, and abbreviate | omits description.

  As shown in FIG. 2, the reinforced heat insulating composite material 6 in the second embodiment is between a pair of sheet-like or plate-like reinforcing fiber materials 2 into which the binder resin 3 mixed with the reinforcing filler 4 is infiltrated. A foam material 7 having a sheet-like or plate-like heat insulating effect is sandwiched, and a coating material 5 is applied to both surfaces. The reinforced heat insulating composite material 6 of the second embodiment is mainly used as a wall material, and is particularly suitable as a wall material for a cold container.

  The binder resin 3 mixed with the reinforcing filler 4 in the second embodiment functions as a main material of the reinforced heat insulating composite material 6 as a resin material, and firmly bonds the reinforcing fiber material 2 and the foamed material 7 together. Also functions as an adhesive.

  The foamed material 7 is for making the reinforced heat insulating composite material 6 have heat insulating properties. In the second embodiment, a relatively inexpensive polyethylene foam is used. The reinforcing fiber material 2 infiltrated with the binder resin 3 mixed with the reinforcing filler 4 is bonded so as to be laminated on the foam material 7 before the binder resin 3 is completely cured. As shown in FIG. 2, the reinforcing fiber material 2 is laminated on both side surfaces of the foam material 7, but may be laminated only on one side surface according to needs.

  According to the reinforced heat insulating composite material 6 of the second embodiment, since the foam material 7 has a large number of foam-like air layers, the heat conductivity can be reduced and the heat insulation property can be improved. Further, since the binder resin 3 also functions as an adhesive, the fiber-reinforced plastic 1 and the foamed material 7 can be easily bonded in a short time.

  In addition, the second embodiment is assumed to be used as a wall material for a cold container, and the both sides of the foamed material 7 formed in a sheet shape or a plate shape are bonded with the binder resin 3 mixed with the reinforcing filler 4. The foamed material 7 is compressed by applying a uniform pressure to both side surfaces thereof until the thickness reaches a predetermined thickness, and the pressure is maintained until the binder resin 3 is cured. Here, the predetermined thickness is a thickness that can be held between wall support pillars of the cold storage container. Of course, you may adjust thickness suitably according to the request of an application place.

  Further, by sandwiching the pair of fiber reinforced plastics 1 through the foamed material 7, the bending due to the shrinkage when the binder resin 3 is cured is suppressed as much as possible. By further pressurization, the adhesion between the reinforcing fiber material 2, the binder resin 3, and the foamed material 7 becomes dense, so that the binder resin 3 can uniformly penetrate and the unevenness of characteristics can be suppressed.

  In addition, the volume of the foam-like air layer is also compressed by compressing the foam material 7, but since the total number of air layers is not changed, the heat insulation effect is maintained, and only the amount of moisture entering the air layer is reduced, and the water absorption The rate can be reduced.

According to the second embodiment as described above, the following effects can be obtained in addition to the effects of the first embodiment.
1. It can have excellent heat insulation.
2. The water absorption rate can be reduced and kept light for a long period of time.
3. Bonding between the fiber reinforced plastic 1 and the foamed material 7 is simplified.
4). It is possible to provide the reinforced heat insulating composite material 6 which is strong against twisting during transportation and excellent as a wall material of a cold storage container that is carried on a truck.

"Production method of reinforced thermal insulation composite"
Next, specific examples of the above-described reinforced heat insulating composite material 6 according to the second embodiment of the present invention will be described. In Example 1, the reinforced heat insulation composite material 6 used as the wall material of a cold storage container was produced. As shown in FIG. 3, the manufacturing method of the reinforced heat insulating composite material 6 includes step S1 of mixing a carbon filler 41 as the reinforcing filler 4 in the binder resin 3, and the reinforcing fiber material 2 and the carbon filler 41 in the mold. It consists of step S2 for laminating the mixed binder resin 3 and foamed material 7, step S3 for applying pressure and curing, and step S4 for performing the final molding operation.

  First, a carbon filler 41 made of carbon powder is mixed into the binder resin 3 using an unsaturated polyester resin. The carbon filler 41 is mixed in such an amount that the weight ratio with the binder resin 3 is 1: 100. In the present Example 1, carbon powder with a non-uniform particle size produced before producing a carbon fiber was used. This is because the carbon powder having a non-uniform particle size in this state is inexpensive, and if a desired effect can be exhibited thereby, the merit from the cost side is great. In order to mix in the binder resin 3, the carbon filler 41 is mixed 10 times, and further stirred for about 30 minutes to uniformly distribute the carbon filler 41 in the binder resin 3 (step S1).

  Next, the mold is preheated to 50 ° C. so that the binder resin 3 can flow smoothly. The reinforcing fiber material 2 which is a nonwoven fabric of glass fiber and the binder resin 3 mixed with the carbon filler 41 are laminated on the mold. In Example 1, two reinforcing fiber materials 2 were laminated on one side with a binder resin 3 mixed with a carbon filler 41 interposed therebetween. A plate-like foam material 7 made of polyethylene is placed thereon, and two reinforcing fiber materials 2 and a binder resin 3 are laminated thereon and sandwiched between molds (step S2).

  Hold the pressure uniformly from the upper and lower molds for about 1 hour. In Example 1, a pressure of about 96 tons was applied to form one sheet (step S3).

  Then, leave it until it reaches room temperature. In Example 1, the temperature was lowered to 20 ° C. in about 1.5 hours. Thereafter, using another mold of the same mold that does not perform temperature control, the same pressure as in step 3 was applied and held for about 6 hours to perform the standard work (step S4).

  In Example 1, the surface of the reinforced heat insulating composite material 6 was coated by applying a coating resin after the molding in Step S4.

"Physical properties"
The physical properties of the reinforced heat insulating composite material 6 produced in Example 1 were evaluated. For comparison purposes, a conventional fiber reinforced composite material 6 used in a general cold container, a test piece 1 using a glass fiber woven fabric as the reinforcing fiber material 2, and a length that does not mix uniformly. The thermal conductivity was compared with that of the test piece 2 sprinkled with the carbon fiber not filled in the binder resin 3.

  First, the comparison target will be described. The conventional product is used for a wall material of a general cold container, and is configured by adhering wood to one side of a fiber reinforced plastic obtained by curing glass fiber with a resin with an adhesive.

  The test piece 1 is a heat insulating composite material manufactured by the same manufacturing method as in Example 1 without mixing the carbon filler 41 into the binder resin 3. Further, the foam material 7 is made of polyurethane foam material 7 which is more expensive than polyethylene and has high heat insulating properties, and the reinforcing fiber material 2 is made of woven glass fiber.

  The test piece 2 is a heat insulating composite material produced by sprinkling short carbon fibers without mixing the carbon filler 41 in the binder resin 3 and according to the same procedure as in Example 1.

  Hereinafter, the comparison results of the characteristics of the test pieces will be described with reference to the drawings. FIG. 4 is a table summarizing test data on thermal conductivity, strength, and water absorption.

"Comparison of thermal conductivity"
The thermal conductivity represents the ease of transmission of heat passing through the object or the like, and the smaller the value, the better the heat insulation. As shown in FIG. 4 and FIG. 5, when the outside air temperature is in the −20 ° C. range, the result of comparison was that the thermal conductivity was the largest at about 0.15 W / (m · K) of the conventional product. . On the other hand, the test piece 1 had the lowest thermal conductivity and was about 0.04 W / (m · K). The test piece 2 was about 0.06 W / (m · K), and the product of Example 1 was about 0.07 W / (m · K).

  Similarly, when comparing the thermal conductivity when the outside air temperature path is in the 20 ° C. zone and the 40 ° C. zone, the thermal conductivity tends to increase as the outside air temperature rises overall, but each test in the same temperature zone The magnitude relationship of the thermal conductivity of the piece had the same tendency as in the −20 ° C. band.

  That is, the thermal conductivity of the product of Example 1 and each test piece is about 1/3 smaller than that of the conventional product, indicating that the heat insulation is improved.

"Strength comparison"
Next, the products of Example 1, test piece 1, test piece 2 and conventional products were compared in terms of tensile modulus, tensile strength, tensile fracture elongation, flexural modulus and flexural strength. The tensile test was conducted according to JISK7113, and the bending test was conducted according to JISK7171.

  Note that the small values of the flexural modulus and the flexural strength indicate that the composite material is easy to bend, and the moderate ease of bending can release the force when twisted, leading to the torsional strength.

As shown in FIG. 4 and FIG. 6, the tensile modulus of elasticity is almost the same for the conventional product and the product of the first embodiment, the conventional product is about 5900 kgf / mm ² , and the first product is about 5800 kgf / mm ² . It was mm ^2. On the other hand, the test piece 1 and the test piece 2 were slightly smaller than these tensile elastic moduli, but the test piece 1 was about 5300 kgf / mm ² and the test piece 2 showed about 5400 kgf / mm ² . Therefore, it is confirmed that the tensile elastic modulus is improved by mixing the carbon filler 41 in the binder resin 3, and that of Example 1 is less affected by the tensile force than other comparative test pieces, and is less likely to be distorted. Indicated.

Next, as shown in FIG. 4 and FIG. 7, the tensile strength was 39.6 kgf / mm ² for the conventional product, while the product and test of Example 1 in which the foamed material 7 was held. The tensile strength of the piece 1 was as large as about 52 kgf / mm ^2, and the test piece 2 was also about 47 kgf / mm ² .

  In addition, the tensile elongation at break was 0.7% for the conventional product, whereas the product and the test piece 1 of Example 1 were 1%, and the test piece 2 was 0.9%. The same tendency was shown.

Next, when the results of the bending elastic modulus were compared, as shown in FIGS. 4 and 8, the bending elastic modulus of the conventional product was 2060 kgf / mm ² , whereas the specimen 1 was as large as 2550 kgf / mm ² . However, the test piece 2 was significantly reduced to 343 kgf / mm ² . Further, the product of Example 1 showed 1260 kgf / mm ^2, which was smaller than the conventional product. Therefore, it can be seen that the test piece 2 and the product of Example 1 are less susceptible to bending and have less deflection than the conventional product.

4 and 9, the bending strength of the conventional product is the highest at 38.5 kgf / mm ² , 36.2 kgf / mm ² for test piece 1, and ² for test piece 2. The value of 9.6 kgf / mm ² and the product of Example 1 was 23.8 kgf / mm ^2, which was smaller than the conventional product.

  As described above, the test piece 1 has the same bending strength as that of the conventional product. Therefore, the yield strength against torsion is also equivalent. On the other hand, since the test piece 2 is significantly weaker to bending than the conventional product, the test piece 2 is weak against twisting and may be destroyed before the force is released. The product of the first embodiment has moderate durability against twisting, and has a suitable strength when used under conditions in which twisting occurs due to running of a truck such as a cold container. It is thought that there is.

"Comparison of water absorption rate"
For each test piece, the water absorption rate and the time required for complete drying were compared. In addition, the water absorption rate test was done based on JISK6911.

  As shown in FIGS. 4 and 10, the water absorption rate of the conventional product was 32.2%, but the test piece 1 was 2.6% and the test piece 2 was 0.5%. The product of Example 1 showed an extremely small value of 0.3%. In the case of conventional products, it is considered that water is easily absorbed because wood is used. In addition, the time required to change from the saturated water absorption state to the complete dry state required about 10 hours for the conventional product, but was as short as about 30 minutes for the product of Example 1.

  Therefore, since the wall material of the conventional cold storage container is easy to absorb water, there is a problem that when the cold thawing is repeated, water is absorbed, and the weight of the vehicle decreases due to an increase in the weight of the vehicle. Even if it is used under conditions where it is often touched, the amount of water absorption is very small, so it can be kept lightweight, and an increase in load weight due to water absorption can be effectively suppressed. Moreover, it is excellent also in corrosion resistance and it turns out that it is suitable as members, such as a cold storage container.

It is sectional drawing which shows 1st Embodiment of the fiber reinforced plastic which concerns on this invention. It is a perspective view which shows 2nd Embodiment of the reinforced heat insulation composite material which concerns on this invention. It is a flowchart which shows the preparation methods of the reinforcement heat insulation composite material of the present Example 1. It is a data table | surface which shows the result of having compared the characteristic of the reinforcement heat insulation composite material of the present Example 1, and a conventional product and a comparative test piece. It is a graph regarding heat conductivity among the results of having compared the characteristic of the reinforced heat insulation composite material of the present Example 1 and a conventional product and a comparative test piece. It is a graph regarding a tensile elasticity modulus among the results of having compared the characteristic of the reinforcement heat insulation composite material of the present Example 1 and a conventional product and a comparative test piece. It is a graph regarding tensile strength among the results of comparing the characteristics of the reinforced heat insulating composite material of the present embodiment example 1, the conventional product, and the comparative test piece. It is a graph regarding a bending elastic modulus among the results of having compared the characteristic of the reinforced heat insulation composite material of the example 1 of a present Example, a conventional product, and a comparative test piece. It is a graph regarding bending strength among the results which compared the characteristic of the reinforced heat insulation composite material of the example 1 of a present Example, a conventional product, and a comparative test piece. It is a graph regarding a water absorption rate among the results of having compared the characteristic of the reinforced heat insulation composite material of the present embodiment example 1, a conventional product, and a comparative test piece.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fiber reinforced plastic 2 Reinforced fiber material 3 Binder resin 4 Reinforcement filler 41 Carbon filler 5 Coating material 6 Reinforcement heat insulation composite material 7 Foam material

Claims (3)

  A fiber-reinforced plastic obtained by infiltrating a binder resin mixed with a reinforcing filler into a reinforcing fiber material and curing it.   A reinforced heat insulating composite material obtained by infiltrating a binder resin mixed with a reinforcing filler into a sheet-like or plate-like reinforcing fiber material and laminating and curing a foam material on at least one surface.   Thickness for the wall material of the cold container by sandwiching both side surfaces of the sheet-like or plate-like foam material by a pair of reinforcing fiber materials infiltrated with the binder resin mixed with the reinforcing filler, and compressing the foam material Reinforced heat-insulating composite material characterized by being molded into

Images