JP2006035671A - Frp structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an FRP structure having high rigidity, lightweight property as well as high X ray transmission and damping performance, and to provide a suitable FRP structure for the member of X-ray instruments and the like. <P>SOLUTION: The FRP structure comprises the following structural elements: a thermoplastic resin foam layer [A]; an FRP layer [B] having a continuous carbon fiber as a reinforced fiber; and a sheet-like resin layer [C]. The FRP structure has a laminated composition having the structural element [C] with a thickness of 5-200 μm provided on one side of the structural element [B] and the structural element [A] provided on the other side, and a neutral plane of the FRP structure is in the inside of [A]. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an FRP structure excellent in vibration damping properties, and more particularly to a good-appearance FRP structure suitable as a member of a medical device component or the like that requires high rigidity, light weight, and X-ray permeability.

  For medical equipment parts that require high X-ray transmission, such as cassettes for X-ray imaging, X-ray image conversion panels, and CT top panels, fibers that are superior to X-ray transmission and lighter than aluminum instead of aluminum A structure made of reinforced plastic (hereinafter abbreviated as FRP), particularly made of carbon fiber reinforced plastic (hereinafter abbreviated as CFRP) has been proposed.

  The CFRP structure is effective in reducing the deflection due to its own weight and load, and ensuring the necessary rigidity and strength against impacts. However, an X-ray engineer directly carries in the X-ray equipment members, There are members to handle, and further weight reduction is required.

  In X-ray imaging, it is necessary to sharpen the captured image, but it is required to reduce the X-ray irradiation amount in order to reduce the amount of X-ray exposure to the human body. In order to obtain sharp image characteristics with a smaller amount of irradiation, it is necessary to further improve the X-ray transmittance of the X-ray equipment structure.

  In order to solve this problem, a radiation image conversion panel including a filler layer having a density lower than that of the rigid layer and good X-ray permeability between two rigid layers such as CFRP has been proposed (Patent Document 1). ).

  In this method, sufficient lightness, rigidity, and strength can be obtained, and the X-ray transmission is improved. However, the sharpness of the photographed image is not significantly improved as compared with the conventional CFRP structure. The level is not satisfactory.

  Recently, in order to obtain stable X-ray image characteristics, it has been found that damping is required for vibration transmitted from the outside so that the structure itself does not vibrate greatly during imaging.

  In general, the following requirements are effective for improving the vibration damping performance.

(1) Reduction of initial vibration amplitude of structure by high rigidity (2) Increase of natural frequency by high rigidity and light weight (3) Increase of loss factor related to vibration energy conversion Patent Document 1 is considered from this viewpoint Then, it is considered that the above requirements (1) and (2) are satisfied to some extent by increasing the rigidity and weight, but the requirement (3) is not taken into account, and the damping performance is insufficient. .

As described above, a structural material having sufficient vibration damping has not been proposed so far in medical device parts and the like that require X-ray transparency.
JP 2002-303696 A

      An object of the present invention is to provide an FRP structure in which lightness, X-ray permeability, and vibration damping properties are improved at the same time while having high rigidity in view of the drawbacks of the conventional technology. It is another object of the present invention to provide a suitable FRP structure for an X-ray device structure.

      In order to achieve the above object, according to the present invention, the following means are adopted. That is, it includes the following constituent elements [A], [B], and [C], the constituent element [C] having a thickness of 5 to 300 μm on one side of the constituent element [B], and the constituent element [A] on the other side. And the neutral surface of the FRP structure is inside [A].

[A] Thermoplastic resin foam layer [B] FRP layer using continuous carbon fiber as reinforcing fiber [C] Sheet-like resin layer In the present invention, the FRP layer includes a different type of reinforcing fiber or is continuous. Even if the reinforcing fibers are arranged at different angles and have a non-uniform distribution in the thickness direction, those integrated by the same matrix resin are defined as a single FRP layer.

  In the present invention, the neutral surface is defined as a surface that does not expand or contract because bending stress and bending strain become zero when an external force is applied in the thickness direction and bending deformation occurs.

The component [A] preferably has an apparent density of 0.03 to 0.7 g / cm ³ . The component [A] preferably has a loss coefficient of 0.05 to 1.5 with respect to 110 Hz at 25 ° C. The loss factor here is measured based on JIS K 7244.

  Furthermore, the component [A] preferably has a shear modulus of 0.01 to 0.3 GPa. The shear modulus of elasticity of the thermoplastic resin foam here is a physical property value measured based on ASTM D3846. Furthermore, the constituent element [A] preferably has an average diameter of the foamed cell of 1 mm or less.

  The component [B] preferably contains 30 to 80% by weight of continuous carbon fiber having a tensile modulus of 200 to 850 GPa. Moreover, it is preferable that the said component [B] contains the structure which laminated | stacked the continuous carbon fiber arranged in one direction at a different angle.

  The ratio Ta / Tb between the total thickness Ta (mm) of the component [A] and the total thickness Tb (mm) of the component [B] is preferably 0.5 to 10.

  The component [C] is preferably made of a resin having a tensile elastic modulus of 0.5 to 5 GPa. The tensile elastic modulus of the sheet-like resin layer is a physical property value based on JIS K 7161. Moreover, it is preferable that the said component [C] consists of resin whose loss coefficient with respect to 110Hz at 25 degreeC is 0.01-1.00.

  Ratio ηa / loss factor ηa for 110 Hz at 25 ° C. of the thermoplastic resin foam constituting the component [A] and loss factor ηc for 110 Hz at 25 ° C. of the thermoplastic resin constituting the component [C] ηc is preferably 1 to 100.

The overall apparent density is 0.2 to 1.4 g / cm ³ . Moreover, it is preferable that the whole thickness is 0.8-5.0 mm.

  The FRP structure preferably includes a structure in which the constituent element [B] is arranged on both sides of the constituent element [A]. It is preferable that at least one surface is the component [C], and the arithmetic average roughness (Ra) of the surface is 0.05 to 0.5 μm. The arithmetic mean roughness (Ra) of the surface here is measured based on JIS B 0601.

  The FRP structure of the present invention is preferably used as a medical device component that requires X-ray transparency.

  The thermoplastic resin foam constituting the component [A] is heat-press molded so that the thickness after molding of the thermoplastic resin foam is 0.2 to 0.95 times the thickness before molding, and the component [A], [B] and [C] are preferably integrated.

  The thermoplastic resin foam constituting the constituent element [A] is heat-press molded so that the thickness after molding is 0.2 to 0.95 times the thickness before molding, and the constituent element [A ] And [B] are integrated, and it is also preferable to form component [C].

  According to the present invention, it includes a laminated structure in which a thermoplastic resin foam layer, an FRP layer having continuous carbon fibers as reinforcing fibers, and a sheet-like resin layer are sequentially arranged, and the neutral surface of the FRP structure is a thermoplastic resin. FRP structure that is placed inside the foam layer and the sheet-like resin layer has a thickness in the range of 5 to 200 μm, and thus has high rigidity, light weight, high X-ray permeability, and excellent vibration damping. Can be obtained.

        Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

1, 2 and 3 are all perspective views of the FRP structure according to the present invention.
Each of these is an FRP structure including a laminated structure in which a thermoplastic resin foam layer 1 and a sheet-like resin layer 3 are arranged with an FRP layer 2 interposed therebetween.

  The FRP layer 2 is necessary to ensure high strength and rigidity. It is formed by impregnating a reinforcing fiber with a matrix resin. In the present invention, in order to ensure higher lightness and X-ray transmittance, mechanical properties such as strength and rigidity can be obtained with a smaller thickness. Therefore, the form of the reinforcing fiber needs to be a continuous fiber. .

  As a material of the reinforcing fiber, a carbon fiber having excellent specific strength and specific elastic modulus and good X-ray permeability among inorganic fibers and organic fibers is used. Examples of the carbon fiber include polyacrylonitrile (PAN), pitch, and cellulose, but PAN-based carbon fiber is preferable from the balance of strength and rigidity, and a tensile elastic modulus is more preferably 200 to 850 GPa. A tensile modulus of 200 GPa or more is preferable because the rigidity necessary for the FRP layer 2 can be obtained efficiently. The higher the tensile modulus, the more the required rigidity can be obtained with a small carbon fiber content, which is more preferable in terms of light weight and X-ray permeability. Furthermore, if there is a carbon fiber having a high tensile elastic modulus, it can be used.

  In addition, other reinforcing fibers such as glass fibers, organic high modulus fibers (for example, polyaramid fibers “Kevlar” manufactured by DuPont, USA), alumina fibers, silicon carbide fibers, boron fibers, unit price silicon fibers, etc. You may use together a strength, a high elastic modulus fiber, etc.

  Further, synthetic fibers such as polyamide fibers, polyester fibers, acrylic fibers, polyolefin fibers, and vinylon fibers, and organic natural fibers may be included.

  FIG. 4 is a perspective view showing an example of the FRP layer 2 in the FRP structure according to the present invention. The FRP layer is usually formed by laminating a plurality of layers of continuous carbon fibers 4 oriented in one direction and a layer 2 ′ composed of a matrix resin 5. The number of layers and the angle of each layer of the continuous carbon fiber 4 are not particularly limited, and can be arbitrarily set according to required strength and rigidity. The layers of the layer 2 'oriented in the one direction are preferably laminated in different orientation directions. The different orientation directions only need to include at least two kinds of orientation directions, and a plurality of layers 2 ′ constituting the FRP layer 2 may include a layer 2 ′ having the same orientation angle.

  Another example of the FRP layer 2 may include a continuous carbon fiber fabric and a layer including a layer made of a matrix resin 5. Preferably, continuous carbon fibers aligned in one direction are formed at different angles. It includes a structure of the type represented by FIG. Continuous carbon fibers that are aligned in one direction exhibit less bending than continuous carbon fiber fabrics, and therefore exhibit higher rigidity when carbon fibers with the same tensile modulus are used at the same fiber content. In addition to the fact that the carbon fibers are likely to be uniformly distributed in the plane, there is no void such as a texture, so that a uniform X-ray transmission distribution is easily obtained.

  Moreover, it is preferable that the FRP layer 2 contains the continuous carbon fiber 4 within the range of the tensile elastic modulus of 200 to 850 GPa within the range of 30 to 80% by weight of the FRP layer 2. When the carbon fiber content is less than 30% by weight, the weight required for the FRP layer 2 to obtain the required rigidity increases, so that it is difficult to obtain high rigidity while maintaining the light weight of the FRP structure. . On the other hand, when the carbon fiber content is higher than 80% by weight, it becomes difficult to uniformly impregnate the reinforcing fibers with the matrix resin 5, and the quality problems such as insufficient strength of the FRP structure and remarkably poor appearance quality. May occur.

  As the matrix resin 5, a thermosetting resin or a thermoplastic resin can be used. Specific examples of thermosetting resins include epoxy resin, phenol resin, unsaturated polyester resin, vinyl ester resin, cyanate resin, benzoxazine resin, maleimide resin, polyimide resin, etc., heat or energy from outside such as light or electron beam And a resin which is cured at least partially to form a three-dimensional cured product. Specific examples of the thermoplastic resin include ABS resin, polyethylene terephthalate resin, nylon resin, and polyimide resin. As matrix resin applied to this invention, thermosetting resins, such as an epoxy resin, are preferable.

  When a thermosetting matrix resin is used, the glass transition temperature is 100 ° C. or higher, preferably 120 ° C. or higher, more preferably 150 ° C. or higher. The reason is that the FRP structure of the present invention may be applied with a surface treatment process such as painting or vapor deposition at around 100 ° C., and if the glass transition temperature of the matrix resin is less than 100 ° C. This is because the rigidity of the structure is lowered, causing problems of deformation and warping.

  The thermoplastic resin foam layer 1 is for increasing the secondary moment of the cross section without impairing the light weight in the FRP structure, and obtaining high rigidity as the FRP structure. Furthermore, since the thermoplastic resin foam layer 1 is generally lower in density than the FRP layer 2 containing continuous carbon fibers 4, it is excellent in X-ray permeability.

  X-ray transparency depends on the molecular weight and thickness of the structure material. In general, the smaller the molecular weight and / or thickness, the better the X-ray transparency. That is, the FRP structure includes the thermoplastic resin foam layer 1 having a small apparent density, and the smaller the overall thickness, the more easily X-rays are transmitted. Therefore, a clear image can be obtained with high contrast even at a low dose. In medical radiology equipment, the ease of X-ray transmission of a structure is evaluated by a parameter called aluminum equivalent (mmAl). This is a measure of how much the X-ray transmittance of the structure corresponds to the thickness of the aluminum, and the smaller the aluminum equivalent, the higher the X-ray transmittance and the better.

  In order to obtain stable X-ray image characteristics when the FRP structure of the present invention is used as a member for an X-ray device, the vibration damping performance of the structure against vibration from outside the structure is improved during imaging. I need it. The main requirements for this are as follows.

(1) Reduction of initial vibration amplitude of structure (2) Increase of natural frequency of structure (3) Increase of loss factor of structure High rigidity is effective for (1) and (2). It is effective to increase the elasticity and / or increase the thickness. In the present invention, by providing the FRP layer 2 having continuous carbon fibers having a high elastic modulus, high rigidity is achieved, and effects are exerted on (1) and (2).

  Further, weight reduction is effective for (2), and it is effective to reduce the density and / or thickness of the member. In this invention, density reduction is achieved by providing the thermoplastic resin foam layer 1, and an effect is demonstrated with respect to (2).

  Further, the improvement in dynamic viscoelasticity and / or friction within the structure converts vibration energy into other energy, which is effective in (3). In the present invention, generally, by using a thermoplastic resin having a higher dynamic viscoelasticity than a metal or a thermosetting resin, the vibration energy of the thermoplastic resin foam layer 1 is increased with respect to external vibration. Loss is converted into thermal energy, and the vibration amplitude is attenuated. Also, vibration energy is converted into heat energy by friction between the reinforcing fiber and the matrix resin inside the FRP layer 2. Furthermore, since the FRP layer 2 is in contact with the thermoplastic resin foam layer 1, vibration energy transmitted through the FRP layer 2 can be expected to be attenuated at the interface with the thermoplastic resin layer 1. Since the surface of the thermoplastic resin foam layer 1 is unlikely to be a smooth surface due to the cell structure, the contact area with the FRP layer 2 increases compared to the case of planar contact, and is particularly effective in damping vibration energy. It is effective. Similarly to the thermoplastic resin foam layer 1, the sheet-like resin layer 3 can be expected to be lightweight, X-ray transmissive and vibration-damping. Moreover, by arranging in contact with the FRP layer 2, it is possible to conceal the fiber pattern and black color of the FRP layer 2 and to expect excellent design.

  In this laminated structure, the neutral surface of the FRP structure needs to be disposed inside the thermoplastic resin foam layer 1. As a result, it is possible to reduce the influence of deformation due to bending stress on the thermoplastic resin foam layer 1 having a smaller elastic modulus than the FRP layer 2 and the sheet-like resin layer 3, and to improve the bending rigidity of the FRP structure. .

  Moreover, the thickness of the sheet-like resin layer 3 needs to be in the range of 5 to 300 μm. This is because the vibration damping effect becomes insufficient when the thickness is less than 5 μm. Moreover, if thickness is 50 micrometers or more, since an external appearance design property improves with the concealment effect, it is preferable. On the other hand, when the thickness is larger than 300 μm, the specific elastic modulus of the FRP structure is lowered, which leads to a decrease in rigidity and an increase in weight of the FRP structure.

  The material of the thermoplastic resin foam layer 1 is polyamide resin, modified phenylene ether resin, polyacetal resin, polyphenylene sulfide resin, liquid crystal polyester, polyethylene terephthalate, polybutylene terephthalate, polyester resin such as polycyclohexanedimethyl terephthalate, polyarylate resin, polycarbonate Resin, polystyrene resin, HIPS resin, ABS resin, AES resin, styrene resin such as AAS resin, acrylic resin such as polymethyl methacrylate resin, polyolefin resin such as vinyl chloride, polyethylene, polypropylene, modified polyolefin resin, thermoplastic polyimide, Imide resins such as polymethacrylimide and polyetherimide, ethylene / propylene copolymer, ethylene / 1- Ten copolymer, ethylene / propylene / diene copolymer, ethylene / carbon monoxide / diene copolymer, ethylene / (meth) acrylate glycidyl, ethylene / vinyl acetate / (meth) acrylate glycidyl copolymer, poly There are various elastomers such as ether ester elastomers, polyether ether elastomers, polyether ester amide elastomers, polyester amide elastomers, polyester ester elastomers, etc., but are not limited to these, and these may be used alone, Two or more types of mixtures may be used.

In the FRP structure of the present invention, the thermoplastic resin foam layer 1 is preferably made of a thermoplastic resin foam having an apparent density of 0.03 to 0.7 g / cm ³ . If the apparent density of the thermoplastic resin foam is 0.03 g / cm ³ or more, it is preferable because sufficient strength and rigidity can be secured for the FRP structure. In addition, when the apparent density is 0.7 g / cm ³ or less, the lightness and X-ray transparency are good, and the degree of freedom of design is widened.

  Further, the thermoplastic resin foam preferably has a loss coefficient with respect to 110 Hz at 25 ° C. in the range of 0.05 to 1.5. If the loss coefficient is 0.05 or more, vibration energy is efficiently attenuated. On the other hand, a larger loss factor is preferable from the viewpoint of vibration energy attenuation. However, in general, in a region where the loss factor exceeds 1.5, the loss of rigidity increases, so the loss factor is preferably 1.5 or less. This is preferable because design constraints are reduced.

  In addition, since the thermoplastic resin foam layer 1 is disposed including the neutral plane in the FRP structure, the shear elastic modulus contributes more to the bending rigidity of the FRP structure than the bending elastic modulus. Further, in a region where the shear elastic modulus exceeds 0.3 GPa, since the loss coefficient is generally small, the vibration damping performance is lowered. From such a viewpoint, the thermoplastic resin foam layer 1 is preferably made of a thermoplastic resin foam having a shear modulus of 0.01 to 0.3 GPa.

  Moreover, it is preferable that the thermoplastic resin foam layer 1 consists of a thermoplastic resin foam whose average diameter of a foam cell is 1 mm or less. If the average diameter is 1 mm or less, even if the thickness of the thermoplastic resin foam layer 1 is thin (for example, if it is a thin wall thickness of 2 mm or less, etc.), the strength variation hardly occurs, and the FRP structure has a stable strength. This is preferable because X-rays that have passed through have a more uniform intensity distribution and are less likely to scatter X-rays inside the thermoplastic resin foam layer 1.

  Further, the ratio Ta / Tb between the total thickness Ta (mm) of the thermoplastic resin foam layer 1 as the component [A] and the total thickness Tb (mm) of the FRP layer 2 as the component [B] is 0. Preferably it is in the range of 5-10. If this ratio is 0.5 or more, it becomes possible to ensure the vibration damping property and X-ray permeability as the FRP structure by a sufficient thickness of the thermoplastic resin foam layer 1. The degree of freedom increases. Moreover, if it is 10 or less, it is preferable since it can design without worrying about the point of bending rigidity and a fall of intensity | strength.

  The sheet-like resin layer 3 can be made of various thermosetting resins such as those mentioned in the matrix resin 5 of the FRP layer 2 or various thermoplastic resins mentioned in the thermoplastic resin foam layer 1. The sheet-like resin layer 3 may include a woven fabric or a non-woven fabric made of the same kind or different kinds of synthetic resins. Furthermore, the sheet-like resin layer 3 can obtain a color tone having a high degree of freedom, a smooth surface close to a mirror surface, a surface structure having a high design such as a texture, and the like. The fiber pattern and black color can also be concealed. As the formation of the sheet-like resin layer 3, a film, a sheet material, or a nonwoven fabric may be disposed on the surface of the FRP structure, or a molten thermoplastic resin may be applied, coated, or molded.

  Moreover, it is preferable that the sheet-like resin layer 3 consists of resin in the range whose tensile elasticity modulus is 0.5-5GPa. This is effective for ensuring high rigidity of the FRP structure. Moreover, it is preferable that the sheet-like resin layer 3 consists of resin whose loss coefficient with respect to 110 Hz in 25 degreeC exists in the range of 0.01-1.00. This is effective for maintaining a balance between high damping of vibration energy and rigidity, and reducing design constraints, as in the thermoplastic resin foam layer 1.

  Ratio ηa / loss factor ηa for 110 Hz at 25 ° C. of the thermoplastic resin foam constituting the component [A] and loss factor ηc for 110 Hz at 25 ° C. of the thermoplastic resin constituting the component [C] ηc is preferably 1 to 100. When it is 1 or more, it is possible to dispose a structure with a large loss coefficient in the vicinity of a neutral surface having a high vibration damping effect, which is preferable in order to improve the damping performance of the FRP structure. In the case of 100 or less, it is possible to maintain an appropriate balance between vibration damping properties and bending rigidity, which is preferable in order to reduce design restrictions.

Furthermore, the apparent density of the entire FRP structure is preferably in the range of 0.2 to 1.4 g / cm ³ . In order to improve portability, X-ray permeability and vibration damping properties, a light weight with an apparent density of 1.4 g / cm ³ or less is effective. On the other hand, a density of 0.2 g / cm ³ or more is preferable because sufficient strength and bending rigidity can be easily obtained, and design restrictions can be reduced.

  Moreover, it is preferable that the thickness of the whole FRP structure exists in the range of 0.8-5.0 mm. When the thickness is 0.8 mm or more, the improvement in lightness and X-ray permeability is properly balanced with the securing of strength, rigidity, and vibration damping properties, and design constraints can be reduced. . On the other hand, when the thickness is 5.0 mm or less, lightness and X-ray transmission are improved, and interference is caused between parts because it is thin when incorporated into a part of the apparatus as a structure. This is preferable because it is less likely to be restricted by the thickness of the device design.

  Furthermore, the FRP structure of the present invention has a structure in which the component [B] is disposed on both sides of the component [A], that is, the thermoplastic resin foam layer 1 is sandwiched from both sides by the FRP layer 2 as shown in FIG. More preferably, it has a sandwich structure. This is because the FRP layer 2 having a high bending elastic modulus is disposed on both outer layers where the bending stress increases with respect to the bending load, and the thermoplastic resin foam having a small bending elastic modulus in the vicinity of the neutral surface where the bending stress is zero. This is because the arrangement of the layer 1 is effective in improving the bending rigidity of the FRP structure under the same apparent density. Further, this configuration is preferable because it is effective in reducing the warpage of the FRP structure and the surface smoothness can be easily obtained. Even more preferably, it is a multilayer laminated structure as shown in FIG. 3, and since there are many interfaces between layers, vibration attenuation at the interfaces is large, which is preferable.

  Furthermore, it is preferable that at least one surface of the surface of the FRP structure is composed of the sheet-like resin layer 3, and the arithmetic average roughness (Ra) of the surface is in the range of 0.05 to 0.5 μm. In addition to obtaining high designability as an FRP structure, surface treatment such as painting or vapor deposition may be applied as post-processing on the surface of the FRP structure. This is effective for obtaining a satisfactory surface quality and is preferable for reducing scattering of X-rays incident on the FRP structure.

  The FRP structure of the present invention is an FRP structure that is lightweight and has high strength, high rigidity, and excellent vibration damping properties, and is preferably used as a medical device component that requires X-ray permeability.

  Further, the FRP structure of the present invention is a hot press, an autoclave, a resin transfer molding, or the like so that the thickness of the thermoplastic resin foam layer 1 after molding is 0.2 to 0.95 times the thickness before molding. It is preferable that the thermoplastic resin foam layer 1 and the FRP layer 2 are integrated by heat and pressure molding by using a molding method alone or in combination. As a result, when the heat and pressure molding is performed, the thermoplastic resin foam layer 1 absorbs a part of the molding pressure, and the FRP structure is molded under a uniform pressure distribution in the plane. As a result, it is preferable because the FRP structure with small thickness variation and small residual strain and warpage can be provided. The sheet-like resin layer may be integrated simultaneously with the thermoplastic resin foam layer 1 and the FRP layer 2, or after the thermoplastic resin foam layer 1 and the FRP layer 2 are integrated, by pasting or painting. , May be formed.

(Example)
The measuring method of the tensile elasticity modulus of the carbon fiber used for the Example and the comparative example is shown below.

(A) Tensile modulus The tensile modulus was measured according to the resin impregnated fiber bundle test method of the JIS R 7601 carbon fiber test method. The test piece length was 200 mm, the number of tests was 5 times, and the average value was adopted.

  The FRP structure shown in FIG. 1 was manufactured by the following procedure.

Continuous carbon fiber 4 ("Torayca" T700S manufactured by Toray Industries, Inc.) having a tensile elastic modulus of 230 GPa is aligned in a sheet shape and impregnated with an epoxy resin. The carbon fiber basis weight is 200 g / m ² and the carbon fiber content is 67 weights. % UD prepreg was prepared. Three pieces of this prepreg were cut out in a size of 300 mm in length and 300 mm in width, and three pieces were bonded at room temperature so that the orientation angle was (0 ° / 90 ° / 0 °) to obtain a prepreg laminate.

  One polypropylene resin foam sheet with a thickness of 3.0 mm ("Fcel" CP4030 manufactured by Furukawa Electric Co., Ltd.) and one PET film with a thickness of 0.19 mm ("Lumirror" S10 # 188 manufactured by Toray Industries, Inc.) Each was prepared in a size of 300 mm in length and 300 mm in width.

  These were laminated at room temperature so as to be (polypropylene resin foam sheet / prepreg laminate / PET film having an orientation angle of (0 ° / 90 ° / 0 °)) to obtain a laminate. The laminate was heated and pressurized at 130 ° C. and 1 MPa for 60 minutes using a hot press apparatus to cure the prepreg laminate and bond each layer to obtain an FRP structure having a thickness of 3 mm.

  In the obtained FRP structure, the polypropylene resin foam sheet corresponds to the thermoplastic resin foam layer 1, the cured prepreg laminate corresponds to the FRP layer 2, the PET film corresponds to the sheet-like resin layer 3. .

  The surface of the sheet-like resin layer 3 of the obtained FRP structure was smooth and good without any defects such as irregularities. According to JIS B 0601 surface roughness-definition and display, the arithmetic average roughness (Ra) of the surface of the FRP structure on the sheet-like resin layer 3 side was measured with a stylus type surface roughness meter. The cut-off value λc was 0.8 mm, the evaluation length ln was 4 mm, the number of tests was 5 times, and the average value was obtained. The arithmetic average roughness (Ra) was 0.2 μm.

  Further, the cross section of the FRP structure was observed with an enlarged microscope, and the total thickness of the thermoplastic resin foam layer 1 and the total thickness of the FRP layer 2 were measured. (Total thickness of the thermoplastic resin foam layer 1 (mm)) / (Total thickness (mm) of the FRP layer 2) was determined to be 3.92.

  Moreover, 20 foam cells of the thermoplastic resin foam layer 1 were randomly selected by observing the enlarged cross section, and the diameter thereof was measured. The average diameter of 20 pieces was 0.15 mm.

Further cut part 5 pieces of the thermoplastic resin foam layer 1 from FRP structure was determined an average apparent density of 5 pieces from the apparent volume and weight, was 0.41 g / cm ^3.

Further, when the apparent density of the FRP structure was determined from the apparent volume and weight of the FRP structure, it was 0.75 g / cm ³ . The thickness of the thermoplastic resin foam layer 1 was 2.25 mm, which was 0.75 times the thickness of the polypropylene resin foam sheet before molding.

  Using an X-ray irradiation device (X-ray high voltage device for diagnosis KXO-30F manufactured by Toshiba Corp.), X-ray transmission was performed at 60 kV toward the smooth surface of the FRP structure and transmitted through the FRP structure. As a result of measuring the dose with a dosimeter (model No. 2025 Radiation Monitor manufactured by Radial Corporation), the aluminum equivalent was 0.17 mmAl.

  From this FRP structure, five strip-shaped test pieces having a width of 15 mm and a length of 140 mm were cut out with the 0 ° direction being the length direction and the 90 ° direction being the length direction. . Using this test piece, a three-point bending test was performed according to the bending test method of JIS K7074 carbon fiber reinforced plastic. The indenter used was a round indenter with a radius of 5 mm, the distance between fulcrums was 120 mm, and the test speed was 8 mm / min. The strip-shaped test pieces were arranged so that the thermoplastic resin foam layer 1 was on the indenter side. The average value of the flexural modulus of the 5 pieces measured in the 0 ° direction was 15 GPa, and the average value of the flexural modulus of the 5 pieces in the 90 ° direction was similarly 11 GPa.

  As a result of structural analysis calculation of the laminated structure, the neutral surface of the FRP structure was disposed inside the thermoplastic resin foam layer 1.

  From the measurement results of the apparent density, the aluminum equivalent, and the flexural modulus, the FRP structure is lightweight, excellent in X-ray permeability, and highly rigid.

  Further, five test pieces having a width of 15 mm and a length of 170 mm were cut out from the FRP structure with the 0 ° direction as the length direction. One end of the test piece was fixed with a vise through a silicon rubber sheet having a thickness of 5 mm and arranged in a cantilever shape with a span of 120 mm. The accelerometer was bonded to the tip of the cantilever with double-sided tape, and the vicinity of the support of the beam was hit with an impact vibration hammer to vibrate the test piece. The hammer impact electrical signal and the acceleration pickup electrical signal are connected to an FFT analyzer (multi-purpose FFT analyzer CF-5210 manufactured by Ono Sokki Co., Ltd.) via an amplifier. The natural frequency of the test piece and the loss factor by the half width method were obtained by FFT analysis. When the average value of the five test pieces was obtained, the natural frequency was 140 Hz and the loss factor was 0.18. The vibration attenuation curve in this case is as shown in FIG. The vertical axis is the vibration amplitude, and the horizontal axis is the time.

  The FRP structure shown in FIG. 2 was manufactured under the following conditions.

  The same UD prepreg as in Example 1 was used as the material for the FRP layer 2. Cut out 6 prepregs with 300mm length and 300mm width, and paste 3 sheets at normal temperature so that the orientation angle of continuous carbon fiber aligned in one direction is (0 ° / 90 ° / 0 °) Two sets of combined prepreg laminates were prepared.

  Separately, the sheet-like resin layer 3 is made of the same two PET films as in Example 1, and the thermoplastic resin foam layer 1 is made of a 2.0 mm-thick polypropylene resin foam sheet (Furukawa Electric Co., Ltd.). One “F-cell” CP3020) made of 300 mm in length and 300 mm in width was prepared.

  These were bonded together at room temperature so as to have the configuration of FIG. 2 to obtain a laminate.

  Two pairs of prepreg laminates in the laminate were bonded so that the orientation angles of the continuous carbon fibers 4 were symmetric with respect to the thickness direction of the laminate. Molding was performed under the same conditions as in Example 1 to obtain an FRP structure having a thickness of 3 mm.

The surface of the obtained FRP structure was smooth and good without any defects such as irregularities. When the characteristics of the obtained FRP structure were measured in the same manner as in Example 1, the arithmetic average roughness (Ra) of the surface was 0.2 μm, (total thickness (mm) of the thermoplastic resin foam layer 1) ) / (Total thickness of FRP layer 2 (mm)) is 1.32, the average diameter of the foamed cell of the thermoplastic foam layer 1 is 0.15 mm, and the apparent density of the thermoplastic resin foam layer 1 is 0.41 g / The apparent density of the cm ³ , FRP structure was 0.94 g / cm ³ , the aluminum equivalent was 0.25 mm Al, the flexural modulus in the 0 ° direction was 30 GPa, and the flexural modulus in the 90 ° direction was 20 GPa.

  The neutral surface of the FRP structure is disposed inside the thermoplastic resin foam layer 1.

The thickness of the thermoplastic resin foam layer 1 was 1.5 mm, which was 0.75 times the thickness before molding.
From the measurement results of the apparent density, the aluminum equivalent, and the flexural modulus, the FRP structure is lightweight, excellent in X-ray permeability, and highly rigid.

  Further, the natural frequency and loss factor of the test piece were obtained by the same method as in Example 1. The natural frequency was 190 Hz and the loss factor was 0.11. The vibration attenuation curve in this case is as shown in FIG. 6, and the vibration amplitude becomes 0 approximation in a short time, and the vibration damping property is excellent.

  An FRP structure as shown in FIG. 2 was manufactured under the following conditions.

The material of the FRP layer 2 includes a carbon fiber basis weight of 320 g / m ² in which a plain woven fabric of continuous carbon fiber 4 (“Torayca” T700S manufactured by Toray Industries, Inc.) having a tensile elastic modulus of 230 GPa is impregnated with an epoxy resin, containing carbon fiber A 50% by weight fabric prepreg was prepared. Two pieces of the prepreg were cut out in a size of 300 mm in length and 300 mm in width.

  Also, two PET films and one polypropylene resin foam sheet as in Example 1 were prepared in a size of 300 mm in length and 300 mm in width, respectively.

  These were bonded together at room temperature so as to have the configuration of FIG. 2 to obtain a laminate. Molding was performed under the same conditions as in Example 1 to obtain an FRP structure having a thickness of 3 mm.

The surface of the obtained FRP structure was smooth and good without any defects such as irregularities. When the characteristics of the obtained FRP structure were measured in the same manner as in Example 1, the arithmetic average roughness (Ra) of the surface was 0.2 μm, (total thickness (mm) of the thermoplastic resin foam layer 1) ) / (Total thickness (mm) of the FRP layer 2) is 2.86, the average diameter of the foam cell of the thermoplastic resin foam layer 1 is 0.2 mm, and the apparent density of the thermoplastic resin foam layer 1 is 0.8. 35 g ^/ cm 3, an apparent density of FRP structure 0.80 g / cm ^3, the aluminum equivalent weight 0.18mmAl, 0 ° direction flexural modulus 17 GPa, 90 ° direction flexural modulus was 17 GPa. The neutral surface of the FRP structure is disposed inside the thermoplastic resin foam layer 1. The thickness of the thermoplastic resin foam layer 1 was 1.95 mm, which was 0.65 times the thickness before molding.
From the measurement results of the apparent density, the aluminum equivalent, and the flexural modulus, the FRP structure is lightweight, excellent in X-ray permeability, and highly rigid.

  Further, the natural frequency and loss factor of the test piece were obtained by the same method as in Example 1. The natural frequency was 150 Hz and the loss factor was 0.14. The vibration attenuation curve in this case is as shown in FIG. 7, and the vibration amplitude becomes 0 approximation in a short time, and the vibration damping property is excellent.

  An FRP structure as shown in FIG. 3 was manufactured under the following conditions.

A continuous carbon fiber 4 having a tensile modulus of 230 GPa ("Torayca" T700S manufactured by Toray Industries, Inc.) is drawn in one direction on the material of the FRP layer 2, and the basis weight of the carbon fiber impregnated with an epoxy resin is 125 g / m ² . A UD prepreg having a carbon fiber content of 67% by weight was prepared, and the prepreg was cut into 8 pieces of 300 mm length and 300 mm width at room temperature so that the orientation angle of the continuous carbon fiber was (0 ° / 90 °). Four sets of prepreg laminates obtained by bonding two sheets were obtained.

  Also, four PET films as in Example 1 and one polypropylene resin foam sheet as in Example 2 were prepared in a size of 300 mm in length and 300 mm in width, respectively.

These were bonded together at room temperature so as to have the configuration of FIG. 3 to obtain a laminate. The four pairs of prepreg laminates in the laminate were bonded so that the orientation angles of the continuous carbon fibers 4 were symmetric with respect to the thickness direction of the laminate. Molding was performed under the same conditions as in Example 1 to obtain an FRP structure having a thickness of 3 mm. The surface of the obtained FRP structure was smooth and good without any defects such as irregularities. When the characteristics of the obtained FRP structure were measured in the same manner as in Example 1, the arithmetic average roughness (Ra) of the surface was 0.2 μm, (total thickness (mm) of the thermoplastic resin foam layer 1) ) / (Total thickness (mm) of the FRP layer 2) is 1.37, the average diameter of the foam cell of the thermoplastic resin foam layer 1 is 0.15 mm, and the apparent density of the thermoplastic resin foam layer 1 is 0.00. 47 g ^/ cm 3, an apparent density of FRP structure 0.99 g / cm ^3, the aluminum equivalent weight 0.21mmAl, 0 ° direction flexural modulus 23 GPa, 90 ° direction flexural modulus was 20 GPa. The neutral surface of the FRP structure is disposed inside the thermoplastic resin foam layer 1. The thickness of the thermoplastic resin foam layer 1 was 1.32 mm, which was 0.66 times the thickness before molding.
From the measurement results of the apparent density, the aluminum equivalent, and the flexural modulus, the FRP structure is lightweight, excellent in X-ray permeability, and highly rigid.

  Further, the natural frequency and loss factor of the test piece were obtained by the same method as in Example 1. The natural frequency was 160 Hz, and the loss factor was 0.17. The vibration attenuation curve in this case is as shown in FIG. 8, and the vibration amplitude becomes 0 approximation in a short time, and the vibration damping property is excellent.

(Comparative Example 1)
Implemented as the material of the FRP layer 2 in Example 1 to the same tensile modulus aligned pull the continuous carbon fibers 4 of 230GPa in one direction into a sheet, a carbon fiber basis weight 125 g / m 2 impregnated with epoxy ^resin, carbon fiber content 67 wt % UD prepreg was prepared. Twenty-two prepregs having a length of 300 mm and a width of 300 mm were cut out, and the orientation angle of continuous carbon fibers aligned in one direction was (0 ° / 90 ° / 0 ° /.../ 90 ° / 0 ° / (0 ° / 90 ° /... / 0 ° / 90 ° / 0 °) were bonded at room temperature to obtain a prepreg laminate. Separately, as the material for the sheet-like resin layer 3, two PET films as in Example 1 were prepared in a size of 300 mm in length and 300 mm in width. These were laminated at room temperature so as to be (PET film / prepreg laminate / PET film) to obtain a laminate. Unlike the examples, the thermoplastic resin foam sheet is not used. Molding was performed under the same conditions as in Example 1 to obtain an FRP structure having a thickness of 3 mm. The surface of the obtained FRP structure was smooth and good without any defects such as irregularities.

When the characteristics of the obtained FRP structure were measured in the same manner as in Example 1, the arithmetic average roughness (Ra) of the surface was 0.2 μm, the apparent density of the FRP structure was 1.55 g / cm ³ , The aluminum equivalent was 0.39 mm Al, the flexural modulus in the 0 ° direction was 49 GPa, and the flexural modulus in the 90 ° direction was 39 GPa. From the measurement results of the apparent density, the aluminum equivalent, and the flexural modulus, the present FRP structure has higher rigidity than the examples, but lacks light weight and X-ray permeability.

  Further, the natural frequency and loss factor of the test piece were obtained by the same method as in Example 1. The natural frequency was 190 Hz, and the loss factor was 0.05. The vibration attenuation curve in this case is as shown in FIG. 9, and more time is required for the vibration amplitude to be approximated to 0 as compared with the example, and the damping performance is inferior.

(Comparative Example 2)
As the material of the FRP layer 2, continuous carbon fibers 4 having the same tensile modulus of 230 GPa as in Example 1 are aligned in a sheet shape in one direction, and the carbon fiber basis weight impregnated with epoxy resin is 200 g / m ² , and the carbon fiber content is 67 weights. % UD prepreg was prepared. Cut out 10 prepregs of 300mm length and 300mm width, and paste 3 sheets at normal temperature so that the orientation angle of continuous carbon fiber aligned in one direction is (0 ° / 90 ° / 0 °) Two sets of combined prepreg laminates were obtained. Further, instead of the thermoplastic resin foam of the embodiment, as a thermoplastic resin sheet, a 1.9 mm thick nylon resin (“Amilan” CM1021 manufactured by Toray Industries, Inc.) sheet obtained by extrusion molding is 300 mm long, horizontal. Prepared in a size of 300 mm. These were laminated at room temperature so as to be (prepreg laminate / thermoplastic resin sheet / prepreg laminate) to obtain a laminate. Unlike Example, the thermoplastic resin foam layer 1 is not used. Two pairs of prepreg laminates in the laminate were bonded so that the orientation angles of the continuous carbon fibers 4 were symmetric with respect to the thickness direction of the laminate. Molding was performed under the same conditions as in Example 1 to obtain an FRP structure having a thickness of 3 mm. The surface of the obtained FRP structure was smooth and good without any defects such as irregularities. When the characteristics of the obtained FRP structure were measured in the same manner as in Example 1, the arithmetic average roughness (Ra) of the surface was 0.8 μm, the apparent density of the FRP structure was 1.24 g / cm ³ , The aluminum equivalent was 0.35 mm Al, the flexural modulus in the 0 ° direction was 42 GPa, and the flexural modulus in the 90 ° direction was 24 GPa.
From the measurement results of the apparent density, the aluminum equivalent, and the flexural modulus, the present FRP structure has higher rigidity than the examples, but lacks light weight and X-ray permeability.

  Further, the natural frequency and loss factor of the test piece were obtained by the same method as in Example 1. The natural frequency was 190 Hz, and the loss factor was 0.08. The vibration attenuation curve in this case is as shown in FIG. 10, and more time is required for the vibration amplitude to be approximated to 0 as compared with the example, and the damping performance is slightly inferior.

(Comparative Example 3)
Two aluminum plates having a thickness of 0.5 mm were cut out in a size of 300 mm in length and 300 mm in width. Separately, one polypropylene resin foam sheet as in Example 1 was prepared as a material for the thermoplastic resin foam layer 1 in a size of 300 mm in length and 300 mm in width. These were bonded together using a two-component curable epoxy resin adhesive so as to be (aluminum sheet / polypropylene resin foam sheet / aluminum sheet) to obtain a structure having a thickness of 3 mm. The surface of the obtained structure was a semi-gloss surface peculiar to aluminum, and was satisfactory without defects such as irregularities. When the characteristics of the obtained structure were measured by the same method as in Example 1, the arithmetic average roughness (Ra) of the surface was 1.0 μm, and the average diameter of the foamed cells of the thermoplastic resin foam layer 1 was 0. 20 mm, the apparent density of the thermoplastic resin foam layer 1 is 0.35 g / cm ³ , the apparent density of the structure is 1.13 g / cm ³ , the aluminum equivalent is 1.10 mm Al, and the flexural modulus in the 0 ° direction is 31 GPa The bending elastic modulus in the 90 ° direction was 31 GPa. The thickness after molding of the thermoplastic resin foam layer 1 was 0.67 times the thickness before molding.
From the measurement results of the apparent density, the aluminum equivalent, and the flexural modulus, this structure lacks light weight and X-ray permeability as compared with the examples.

  Further, the natural frequency and loss factor of the test piece were obtained by the same method as in Example 1. The natural frequency was 210 Hz, and the loss factor was 0.08. The vibration attenuation curve in this case is as shown in FIG. 11. Compared with the example, more time is required for the vibration amplitude to be approximated to 0, and the vibration damping property is inferior.

  The results of Table 1 were obtained for the configurations and various evaluations of Examples 1, 2, 3, and 4 and Comparative Examples 1, 2, and 3. Examples 1, 2, 3, and 4 were lighter in weight, excellent in X-ray permeability, maintained high rigidity, and had excellent vibration damping properties as compared with Comparative Examples 1, 2, and 3.

      The present invention can be applied not only to medical devices that require X-ray transparency but also to housing members for storing electronic devices and mechanical members for aerospace applications. However, the scope of application is limited to these. Is not something

It is a perspective view which shows the FRP structure which concerns on one embodiment of this invention. It is a perspective view which shows the FRP structure which concerns on the other embodiment of this invention. It is a perspective view which shows the FRP structure which concerns on the further another embodiment of this invention. It is an expansion perspective view which shows the FRP layer contained in the FRP structure which concerns on one embodiment of this invention. It is a vibration attenuation curve which concerns on Example 1 of this invention. It is a vibration attenuation curve which concerns on Example 2 of this invention. It is a vibration attenuation curve which concerns on Example 3 of this invention. It is a vibration damping curve which concerns on Example 4 of this invention. It is a vibration damping curve which concerns on the comparative example 1 of this invention. It is a vibration damping curve which concerns on the comparative example 2 of this invention. It is a vibration damping curve which concerns on the comparative example 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thermoplastic resin foam layer 2 FRP layer 3 Sheet-like resin layer 4 Continuous carbon fiber 5 Matrix resin 6 Time when vibration amplitude becomes 0 approximation

Claims (18)

Including the following constituent elements [A], [B], and [C], the constituent element [B] is a constituent element [C] having a thickness of 5 to 300 μm on one side and the constituent element [A] on the other side. A FRP structure having a laminated configuration and having a neutral surface of the FRP structure inside [A].
[A] Thermoplastic resin foam layer [B] FRP layer using continuous carbon fiber as reinforcing fiber [C] Sheet-like resin layer The FRP structure according to claim 1, wherein the component [A] has an apparent density of 0.03 to 0.7 g / cm ³ . The FRP structure according to claim 1 or 2, wherein the component [A] has a loss coefficient of 0.05 to 1.5 with respect to 110 Hz at 25 ° C. The FRP structure according to any one of claims 1 to 3, wherein the component [A] has a shear elastic modulus of 0.01 to 0.3 GPa. The FRP structure according to any one of claims 1 to 4, wherein the constituent element [A] has an average diameter of foamed cells of 1 mm or less. The FRP structure according to any one of claims 1 to 5, wherein the constituent element [B] contains 30 to 80% by weight of continuous carbon fibers having a tensile modulus of 200 to 850 GPa. The FRP structure according to claim 1, wherein the component [B] includes a configuration in which continuous carbon fibers aligned in one direction are stacked at different angles. The ratio Ta / Tb between the total thickness Ta (mm) of the constituent element [A] and the total thickness Tb (mm) of the constituent element [B] is 0.5 to 10. FRP structure. The component [C] is made of a resin having a tensile modulus of 0.5 to 5 GPa, and the FRP structure according to any one of claims 1 to 8. The component [C] is made of a resin having a loss coefficient of 0.01 to 1.00 with respect to 110 Hz at 25 ° C. The FRP structure according to any one of claims 1 to 9. Ratio ηa / loss factor ηa for 110 Hz at 25 ° C. of the thermoplastic resin foam constituting the component [A] and loss factor ηc for 110 Hz at 25 ° C. of the thermoplastic resin constituting the component [C] (eta) c is 1-100, The FRP structure in any one of Claims 1-10. The FRP structure according to claim 1, wherein the overall apparent density is 0.2 to 1.4 g / cm ³ . The FRP structure according to any one of claims 1 to 12, wherein the entire thickness is 0.8 to 5.0 mm. The FRP structure according to any one of claims 1 to 13, which has a structure in which the constituent element [B] is arranged on both surfaces of the constituent element [A]. The FRP structure according to any one of claims 1 to 14, wherein at least one surface is a constituent element [C], and the arithmetic average roughness (Ra) of the surface is 0.05 to 0.5 µm. The FRP structure according to any one of claims 1 to 15, which is used as a medical device part requiring X-ray transparency. The thermoplastic resin foam constituting the component [A] is heat-press molded so that the thickness after molding of the thermoplastic resin foam is 0.2 to 0.95 times the thickness before molding, and the components [A], [ The manufacturing method of the FRP structure which integrates B] and [C] and obtains the FRP structure in any one of Claims 1-15. The thermoplastic resin foam constituting the component [A] is subjected to heat and pressure molding so that the thickness after molding of the thermoplastic resin foam is 0.2 to 0.95 times the thickness before molding, and the components [A] and [A The manufacturing method of the FRP structure which forms the component [C] after integrating B] and obtains the FRP structure in any one of Claims 1-15.

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