JP7000518B2 - Method for producing deposits containing thermoplastic resin and discontinuous carbon fiber - Google Patents

Description

The present invention is a method for inspecting the internal state of a deposit containing a thermoplastic resin and discontinuous carbon fibers and a material obtained from the deposit using infrared rays or X-rays, and the appearance, voids, and foreign matter of the material. The present invention relates to a method for producing a deposit including a step of an inspection method capable of detecting the presence or absence of the deposit as a two-dimensional spatial distribution, and a method for producing a composite material using the deposit as a molding material.

In the industrial world, as a non-destructive inspection method for materials, there is an inspection method using infrared rays or X-rays. A method of heating an inspected object with a xenon lamp and receiving infrared rays from the inspected object to inspect the inspected object is described (see, for example, Patent Document 1). A method of irradiating a plate-shaped resin or a composite material to be inspected with soft X-rays and determining the abundance rate and thickness of voids in the plate material from the difference in permeability is described (for example, non-patented). See Document 1).

However, in this method, since a xenon lamp is used as a method for heating the material, the life of the lamp, the decrease in the amount of light and the increase in noise due to long-term use become problems in the mass production process, which affects the quantification of the basis weight spots ( For example, see Non-Patent Document 1). Further, when a general flash lamp is used, the charge time until its light emission is also an issue, and it is not suitable for short-time task processing. Further, although the method described in Patent Document 1 describes the analysis method, the apparatus described in Non-Patent Document 1 cannot inspect a large product having a side of 300 mm or more in a short time. It is possible. Therefore, in-line inspection of a large product is difficult with the apparatus described in Non-Patent Document 1. Further, there is no description in the literature regarding a method for detecting a slight basis weight spot and a determination of a significant difference in a slight basis weight spot (see, for example, Patent Document 2 and Patent Document 3).

Japanese Patent No. 5574261 Japanese Patent No. 6165207 Jikkensho 58-026328 Gazette

Takahiro Hayashi, Takayuki Kobayashi, Atsushi Takahashi: "Study on Soft X-ray Absorption Coefficient of Composite Materials", Journal of Japan Society for Composite Materials, 42, (5) (2016), 169-177

Therefore, an object of the present invention is an inspection method and an inspection process capable of inspecting and quantifying slight spots on a material containing carbon fiber while being stable for a long period of time. It is an object of the present invention to provide a carbon fiber composite material having no voids and suppressing eye spots.

In order to solve the above problems, the present invention provides the following means. That is, the main inventions in the present invention are as shown below.
<1> A method for producing a deposit containing a thermoplastic resin and an aggregate of discontinuous carbon fibers, wherein the length of one side of the deposit is 300 mm or more, and the deposit is produced through the following steps. Method.
Step 101: If the deposit is in a state where a film, sheet, or non-woven fabric made of a thermoplastic resin is arranged on at least one surface of the aggregate of the discontinuous carbon fibers, the aggregate of the discontinuous carbon fibers. If the texture of the body [g / m ² ] is such that the deposit is a state in which particulate or long fiber or short fiber thermoplastic resin is dispersed in the space in the aggregate of the discontinuous carbon fibers. Inspection step for non-destructively inspecting the grain [g / m ² ] of the deposit (the aggregate of discontinuous carbon fibers or the deposit whose grain is non-destructively inspected is hereinafter referred to as the inspected body 1. .)
Step 201: A step of grasping the basis weight spots of the inspected body 1 based on the inspection result of the step 101.
Step 301: When the aggregate of the discontinuous carbon fibers is the inspected body 1 based on the spots on the spots in the step 201, the spots on the spots are formed on the insufficient spots in the aggregates of the discontinuous carbon fibers. Discontinuous carbon fibers are added so as to reduce the amount, and when the deposit is the object 1 to be inspected, the deposit is discontinuous according to the amount of the shortage so as to reduce the spots on the deposit. The process of adding carbon fiber and / or thermoplastic resin.
The present invention relates to the above <1>, but other matters (for example, matters described in the following [1] to [2]) are also described for reference.
[1] A method for producing a deposit containing a thermoplastic resin and carbon fibers, wherein the length of one side of the deposit is 300 mm or more, and the deposit is produced through the following steps.
Step 101: Inspection step 201 of nondestructively inspecting the appearance of either the aggregate of the discontinuous carbon fibers or the deposit (hereinafter referred to as the inspected body 1) Step 201: Inspection result of the step 101. Step 301 for grasping the spots on the subject 1 based on A step of adding the discontinuous carbon fibers to the surface, or a step of adding an aggregate of the discontinuous carbon fibers and / or a thermoplastic resin to the portion of the deposit where the appearance is insufficient so as to reduce the unevenness of the appearance [2] Carbon. A method for inspecting an aggregate of fibers, a deposit containing an aggregate of a thermoplastic resin and the aggregate of the discontinuous carbon fibers, or a composite material obtained by heating the deposit and impregnating the discontinuous carbon fibers with the thermoplastic resin. The aggregate, the deposit, or the composite material (hereinafter, referred to as the inspected body 2) has a side length of 300 mm or more, and undergoes the following steps. Inspection method.
Step 111: Inspection process for non-destructively inspecting the basis weight of the object 2 to be inspected Step 211: A step of grasping the basis weight spots of the object 2 to be inspected based on the inspection result of the step 111.

By carrying out the present invention, it is possible not only to perform a qualitative inspection for the presence or absence of foreign matter inside the material and the presence or absence of voids inside the material, but also to quantitatively inspect a slight basis weight spot on the material. At the same time, it is possible to provide a method for producing a carbon fiber composite material in which the basis weight spots are suppressed or reduced by going through the inspection step.

Here, a method for producing an aggregate of deposits or discontinuous carbon fibers containing a thermoplastic resin and discontinuous carbon fibers, wherein the length of one side of the deposit or the aggregate of discontinuous carbon fibers is 300 mm or more. Disclosed is a method for producing an aggregate of deposits or discontinuous carbon fibers through the following steps.
Step 101: Presence or absence of foreign matter other than the thermoplastic resin and carbon fibers in either the aggregate of the discontinuous carbon fibers or the deposit (hereinafter referred to as the inspected body 1), 1 mm × 1 mm or more. Inspection step of inspecting the presence or absence of voids or the appearance in a non-destructive manner Step 201: Understanding the appearance spots of the inspected body 1 based on the inspection result of the step 101 Step 301: Based on the appearance spots of the step 201 , The step of adding the discontinuous carbon fiber so as to reduce the unevenness in the spots in the aggregate of the discontinuous carbon fibers, or not to reduce the spots in the spots in the deposit. Step of adding continuous carbon fiber and / or thermoplastic resin

Further, it is a method for inspecting an aggregate of discontinuous carbon fibers, a deposit containing a thermoplastic resin and discontinuous carbon fibers, or a composite material in which the deposit is heated and the discontinuous carbon fibers are impregnated with the thermoplastic resin. The aggregate, the deposit, or the composite material (hereinafter referred to as the inspected body 2) has a side length of 300 mm or more and undergoes the following steps other than the thermoplastic resin and the carbon fiber. Also disclosed is a method for inspecting the presence or absence of foreign matter, the presence or absence of voids of 1 mm × 1 mm or more, or the spots on the eyes (hereinafter referred to as spots on the eyes).
Step 111: Presence / absence of foreign matter other than the thermoplastic resin and carbon fiber of the object 2 to be inspected, presence / absence of voids of 1 mm × 1 mm or more, or inspection step of non-destructive inspection of eye spots Step 211: Inspection result of the step 111 Step 311: Based on the eye-catching spots and the like in the step 211, the eye-catching spots are reduced in the places where the eye-catching is insufficient in the aggregate of the discontinuous carbon fibers. The step of adding the discontinuous carbon fiber so as to be performed, or the step of adding the discontinuous carbon fiber and / or the thermoplastic resin so as to reduce the unevenness of the grain to the portion where the grain is insufficient.

Also shown herein is a manufacturing method comprising at least one of a raw material, an in-process intermediate (intermediate product), or a final product in the above inspection method. Hereinafter, the terms "the present method" and "the present invention" without particular reference refer to both an inspection method and a manufacturing method including inspection by the inspection method.

(Non-destructive inspection using infrared rays)
Infrared rays used for inspection are generally emitted from the inspected body 1 or the inspected body 2 (hereinafter, when both are referred to, simply referred to as the inspected body) in a state where the inspected body has a certain heat. Is to be done. The infrared rays may be heated and radiated in the process in which the object to be inspected is manufactured, or may be intentionally heated and radiated from the outside outside the manufacturing process for the present invention. .. The heating device is not particularly limited, and examples thereof include halogen lamps, flash lamps, carbon lamps, quartz lamps, laser light, electromagnetic induction heating, and dielectric heating. In the present invention, it is preferable to use laser light. Further, examples of the laser beam include a CO ₂ laser (carbon dioxide gas laser), a YAG laser, a semiconductor laser, and a fiber laser. Among them, the life of the heating device is extended, the energy conversion efficiency to the laser is stable and controllable, and the heat energy with few spots can be supplied. It is more preferable to use a fiber laser from the viewpoint that even if there is, it can be heated without spots. The output of the laser oscillator depends on the irradiation area and width of the laser, but is preferably 0.1 kW or more and 10.0 kW or less, more preferably 0.3 kW or more and 8.0 kW or less, and 1.0 to 5.0 kW. More preferred. Further, it is preferable to irradiate and heat the object to be inspected after passing through a device for adjusting or controlling the irradiation range (irradiation area, irradiation width, etc.) of the laser, and to detect the emitted infrared rays. Specifically, it is preferable that the laser beam is adjusted by passing it through a collimator and then irradiated to the object to be inspected for use.

An infrared sensor is preferable as an inspection device for detecting the emitted infrared rays. As the infrared sensor, it is preferable to select a pixel that can capture the required temperature amplitude and has spatial resolution. The temperature amplitude preferably has a resolution of 0.1 degC (° C.) or less, more preferably 0.08 degC (° C.) or less, and most preferably 0.05 degC (° C.) or less. .. As the spatial resolution, it is preferable to have a resolution of 5 mm or less per pixel.
Further, the index actually used for the analysis does not have to be the actual temperature, and the luminance temperature or a standardized numerical value (0 to 100%, 0 to 256, etc.) may be used. Further, it is preferable to detect the emitted infrared rays and use the method of phase analysis because the difference in heat conduction of the inspected object appears as a timed change of the temperature amplitude.

In phase analysis, heat is applied to the object to be inspected from a heating device such as laser light, and the heat is transferred to the inside, and then the phase difference due to the difference in how the heat of the energy (infrared rays) radiated from the surface is transmitted is analyzed. It is to be. This method of heat transfer is due to the difference in thermal conductivity, specific heat, and density of the inspected object, which is shown when the thermal conductivity is expressed by a mathematical formula. That is, there is a difference in the time variation of the surface temperature of the inspected object and the radiant energy of infrared rays from the surface depending on the internal state of the inspected object. The large detectable spots in the body to be inspected are the presence of voids and foreign substances such as metals, and the small basis weights are the weights of the resin and reinforcing fibers contained in the body to be inspected [g / m ² ]. ] Is the difference. The time required for phase analysis is preferably short because there is a tact time that can be applied to each process of the production line. When the time required for the phase analysis is intentionally described, it is preferably 30 minutes or less, more preferably 10 minutes or less, and most preferably 5 minutes or less. The object to be inspected may be inspected in a state of being conveyed by a device such as a conveyor, or may be inspected in a state of being stopped for a certain period of time for inspection. When using a heating device, the infrared sensor is installed on the same side as the heating device with respect to the inspected object, and after deep heat conduction to the inspected object, it is radiated back to the surface on the heating side. You may catch infrared rays. On the other hand, an infrared sensor may be installed on the side facing the heating device to conduct heat deeply to the inspected object and then capture the infrared rays radiated from the surface on the opposite side to the heating side. When installed on the same side as the heating device, it is preferable because the space for installing the entire inspection device is small, and when installed at a position facing the heating device, the distribution in the thickness direction of the inspected object is accurate. It is preferable because it can be caught.

In order to perform the above processing, it is preferable that the inspection device is equipped with a computer for arithmetic analysis and image processing for performing phase analysis and image processing, and a drawing monitor for displaying an image. A plurality of captured images are used for phase analysis, and in performing the phase analysis, it is common to perform numerical calculation by FFT (Fast Fourier Transform) using digital data of each pixel of the captured image. In order to complete this numerical calculation process in a short time, it is preferable that a computer having excellent processing capacity is installed. In addition, software for image processing is installed in the computer, and the threshold value and image processing flow can be set in advance in the software, and after the image is captured, the pass / fail judgment can be made for the temporary threshold value. preferable. By performing such an operation, it is possible to grasp the basis weight spots of the inspected object by analyzing the inspection data of the emitted infrared rays. The basis weight can be quantified based on the inspection data and the calibration curve prepared in advance for the basis weight, and the basis weight spot can be inspected. The size of the space average when handling the basis weight spots is preferably 1 mm × 1 mm or more and 300 mm × 300 mm or less, more preferably 3 mm × 3 mm or more and 150 mm × 150 mm or less, and 5 mm × 5 mm or more and 100 mm × 100 mm or less. Most preferred.

These software and the device used in the present invention communicate with the device in the upstream process of the production process of the inspected object, and the information on the spots on the inspected object obtained from the radiated infrared inspection data is transmitted to the upstream process. It is preferable to send to. Using the transmitted information on the spots on the surface, in the equipment in the upstream process of the manufacturing process of the inspected object, various parameters related to the determination and control of the spots are controlled in the direction of reducing the spots on the surface, so that the composite material can be used in real time. It is preferable to give feedback to the manufacturing process such as, and control the quality to be stable before the intermediate or final product exceeds the allowable value. More specifically, based on the result of the feedback, after this inspection step, the step of adding discontinuous carbon fiber to the place where the numerical value of the grain is low, or the spot where the grain is insufficient in the deposit is formed. There may be a step of adding an aggregate of discontinuous carbon fibers and / or a thermoplastic resin so as to reduce the amount. By adding at least one selected from the group consisting of discontinuous carbon fibers, aggregates of discontinuous carbon fibers, and thermoplastic resin in this way, it is possible to correct the unevenness of the grain, and the composite material can be corrected in the subsequent steps. It is preferable because it reduces the unevenness of the final product. As a method of correcting the unevenness of the grain, based on the image data, an aggregate of discontinuous carbon fibers and / or a thermoplastic resin can be obtained from the material quantitative transfer device within a certain period of time according to the amount of the insufficient amount of the missing part. It is preferable to be supplied.

Further, it is preferable that the coefficient of variation 1 of the basis weight of the aggregate of discontinuous carbon fibers in the object to be inspected thus obtained or the coefficient of variation 2 of the total basis weight of the deposit is 20% or less. When the coefficient of variation is in the range of 20% or less, the basis weight spots are reduced from the above-mentioned grasp of the basis weight spots in the inspected object and the feedback to the manufacturing process of the aggregate or deposit of discontinuous carbon fibers based on the basis weight spots. It is preferable because the step of controlling various parameters so as to be performed is executed quickly. For faster and more reliable execution, the coefficient of variation is more preferably 0.05% or more and 19% or less, and even more preferably 0.1% or more and 18% or less.

(Non-destructive inspection using X-rays)
The X-rays used in this method are general, and are electromagnetic waves having a short wavelength whose radiation mechanism and properties are different from those of ordinary electromagnetic waves. The wavelength of X-rays used in the present invention is usually several hundred angstroms (1 angstrom is one hundred millionth of a centimeter) to 0.01 angstroms, which is shorter than that of ultraviolet rays and lower than that of γ (gamma) rays. It is said to be long. In the present invention, X-rays having a fixed wavelength are not used, but X-rays having a wavelength distribution having a certain width are used. Therefore, 0.01 × ^10-10 to 100 × ^10-10 m (0.01). It is preferable to include X-rays having a wavelength of (angstrom to 100 angstrom).

Further, the X-rays in the present invention are preferably generated by the method shown below, but usually X-rays having an intensity peak in the above-mentioned wavelength range are used. In the present invention, X-rays having an intensity peak below a wavelength of 1.0 × 10 ^-10 m (1.0 angstrom) are preferably used, and a wavelength of 0.01 × 10 ^-10 to 0.9 × 10 ^-10 m. X-rays with an intensity peak are more preferably used, and X-rays with an intensity peak at a wavelength of 0.05 × 10-10 to 0.8 × ^10-10 m are even more preferably used, 0.1 × ^{10 −} . Most preferably, X-rays having an intensity peak of ¹⁰ m or more and 0.7 × 10 ^-10 m or less are used.

The main properties of X-rays are a) straightness like light, b) well-transmitted substances, c) hard X-rays with good transmission (many components with short wavelengths) and soft X with poor transmission. There are lines (many components with long wavelengths), and so on. Further, when X-rays pass through an object, the X-rays are attenuated depending on the properties of the object, but in general, the atomic numbers of the components that are the density, thickness, and composition of the object through which the X-rays pass are used. Its attenuation depends.

The X-rays used in this method are generally generated by utilizing electrical energy. The filament side of the electrode is the cathode, the target side is the anode, and a high voltage of several kV to several hundred kV is applied between the cathode and the anode. X-rays are emitted when thermions ejected from the filament accelerate toward the anode and collide with a metal target. Tungsten, rhodium, molybdenum, chromium, copper, nickel, iron and the like are preferably used as the metal target used at this time. In the present invention, it is preferable to select one or two of these metal targets. Among these metal targets, it is preferable to select tungsten because it is easy to handle and stable inspection can be continuously performed. On the other hand, since characteristic X-rays with little frequency dependence are emitted, it is preferable to select copper from the viewpoint of easy visibility of eye spots and foreign substances in the inspected object. Further, the voltage applied to the electrode filament is not particularly limited because the wavelength band of the X-ray generated by the metal target changes, but it is 10k.
V to 200 kV is preferable, and 10 kV to 160 kV is more preferable. When the generated X-rays pass through an object (in this method, the object to be inspected), they are partially reflected and scattered by the influence of the atomic nuclei that make up the object to be inspected, and then pass through the object. X-rays are attenuated.

By receiving the attenuated X-rays with the sensor, the transmission intensity of the X-rays that have passed through the object can be grasped. That is, it becomes possible to grasp the properties of the object. Sensors used in X-ray inspection should be used in various shapes such as point-shaped, linear (line sensor), planar (flat panel sensor or area sensor), and C-shaped according to the application. Can be done. The resolution of the sensor is determined by the size of the object to be detected, the amount of X-rays received per unit time (relative exposure amount) depending on the X-ray transmission characteristics and the transport speed, and is 0.05 mm, 0.2 mm, 0. Elements of about 4 mm, 0.8 mm, and 1.6 mm are often used. In the present invention, it is preferable to use a 0.4 mm or 0.8 mm element. As the type of sensor, CCD (Chaged-coupled devices) and CMOS (complementary metal-oxide-semiconductor: complementary metal oxide semiconductor) are preferable, and protective films, scintillators, amplifiers, and X-ray image intensifiers are used. It may be a type via a CCD, a type having a higher sensitivity to X-rays than a general one, or another method. For example, it may be a dual energy sensor that can separate different substances, or if two types of metal targets are used, it is a device that prepares a sensor corresponding to it and analyzes a plurality of images. You may.

Further, a tomographic image by CT (Computed Tomography) may be imaged. In the CT image, basically, the object to be inspected is rotated around any one of the X-ray, Y-axis, and Z-axis when the object to be inspected is placed at the origin of the three-dimensional space, and the rotation axis thereof. It is obtained by irradiating X-rays from all directions perpendicular to the above and analyzing a plurality of images obtained by the X-ray area sensor by numerical processing. That is, since tomographic images at arbitrary positions of the inspected object can be obtained, it is possible to grasp the distribution in the thickness direction, that is, the basis weight by analyzing those images. At the same time, it is possible to detect voids and metal pieces existing in the object to be inspected.

More specifically, the obtained three-dimensional image is acquired as a tomographic image at regular intervals in the thickness direction of the inspected object. Each acquired image is divided into certain sections (for example, length 5 mm × 5 mm square), and the spatial mean value of the digital value in each section is calculated. The same calculation is performed on the tomographic images obtained at regular intervals (for example, every 0.1 mm), and the thickness is used by using the spatial mean value of the digital values of the same section on each plane of the inspected object. Calculate the integrated value for the number of tomographic images in the direction. Based on this numerical value and the calibration curve prepared in advance for the basis weight, the basis weight can be quantified and the basis weight spot can be inspected. The size of the space average when handling the basis weight spots is preferably 1 mm × 1 mm or more and 300 mm × 300 mm or less, more preferably 3 mm × 3 mm or more and 150 mm × 150 mm or less, and 5 mm × 5 mm or more and 100 mm × 100 mm or less. Most preferred.

As an imaging method, the inspected object may be rotated, or the inspected object may be fixed and the X-ray generator and the X-ray area sensor may be used so that the place where the inspected object is installed becomes the rotation axis. Then, it may be rotated to take an image. In particular, the latter method is more preferable when the state of the object to be inspected changes when the object to be inspected is rotated. The number of images to be imaged is preferably 100 to 10,000, more preferably 1,000 to 5,000, from the viewpoint of the resolution required for inspection and the measurement and analysis time.

On the other hand, in addition to CT imaging, it is also preferable to make an image diagnosis using a fluoroscopic image of X-rays. That is, a fluoroscopic image obtained by imaging an inspected object using an X-ray area sensor (flat panel sensor) or an X-ray inspection apparatus equipped with an X-ray line sensor in the inspection process, or data derived from the fluoroscopic image is used. This is a non-destructive method for inspecting the eyes. For example, an inspected object is placed on a device that is driven in one direction, such as a conveyor or a robo cylinder, the inspected object is irradiated with X-rays, and a line sensor is placed at a position that opposes the X-ray source across the inspected object. Or an image in the thickness direction, a method in which the straight line connecting the X-ray source and the line sensor and the transport direction of the inspected object do not intersect at a right angle. May be. The number of X-ray sources, line sensors, or flat panel sensors (area sensors) may be one or more, and the number is not limited. Although the transport speed is not particularly limited, it is preferably 0.1 m / min or more and 1000 m / min or less, more preferably 0.3 m / min or more and 300 m / min or less, and 0.5 m / min or more from the viewpoint of mass productivity and imaging conditions. 100 m / min or less is even more preferable. Alternatively, a method of using a flat panel sensor (area sensor) to temporarily stop the inspected object and take an image may be used. Since it is most preferable to place nothing other than the air to be inspected between the X-ray source and the sensor, the image may be taken at the seam between the conveyors, or it may be installed on the conveyor belt or robo cylinder. The jig may be cut out in a square shape, and the cutout portion may be used for imaging. However, for the purpose of protecting the equipment, transporting the equipment, or cutting the frequency in a specific region, the image may be taken through a thin film, a belt of a conveyor, an aluminum alloy or a copper alloy plate, or a foil. The distance between the X-ray source and the sensor is determined by the imaging field of view and the imaging conditions, and is not particularly limited, but is preferably 0.02 m or more and 7 m or less, and 0.05 m or more and 5 m or less. More preferably, 0.1 m or more and 3 m or less are even more preferable.

In order to take an image as described above, it is preferable that the inspection device is equipped with an image processing computer for image processing and a drawing monitor for displaying an image. The image data may be the raw data of each pixel detected by the sensor, the deviation from the target numerical value may be displayed on each pixel, the spatial average value of the data in a certain pixel section may be displayed on each pixel, or each pixel may be displayed. The image data may be processed by performing a filter process such as amplifying the data of the above 1.0 times or more, or they may be used in combination. In the present invention, the inspection target has a maximum deviation of 1500 g / m ² or less from the average value of the basis weight of the object to be inspected, and an inspection target having a relatively small basis weight spot is assumed. That is, the basis weight spots are obtained by inspection as a difference in digital values due to a difference in X-ray transparency, but the difference in the numerical values is small. In order to judge the difference in the numerical values as a significant difference that can be distinguished from noise, the imaging conditions are such that the spatial average of the digital values in the fluoroscopic image is 5% or more and less than 100% of the detection limit value of the digital values in the fluoroscopic image. It is preferable to do so. Alternatively, a necessary signal can be extracted by including a step of amplifying numerical digital data based on the relative exposure amount of the X-ray or data calculated and processed based on the data more than 1.0 times. Therefore, it is preferable. In the former case, the detection limit of the digital value is preferably 5% or more and less than 100%, more preferably 7% or more and less than 95%, and even more preferably 10% or more and less than 90%. preferable. In the latter case, in order to suppress noise amplification, the data is preferably more than 1.0 times and less than 10.0 times, and more preferably 1.5 times or more and less than 5.0 times.

In addition, image processing software is installed in the computer, and the threshold value and image processing flow can be set in advance in the software. It is even more preferable to be able to do it. It is preferable that the results and image data can be stored so as to ensure traceability.

By communicating with these software and the equipment in the upstream process of the equipment used in the present invention and controlling various parameters of the equipment in the upstream process, feedback of the material manufacturing process is applied in real time, and the intermediate or final product is the allowable value. It is preferable to control so as to stabilize the quality before exceeding. Alternatively, after this inspection step, it is preferable to correct the basis weight spot by adding a discontinuous carbon fiber and / or a thermoplastic resin to a portion having a low basis weight value.
As a method for correcting the basis weight spots, it is preferable that the basis weight is supplied from the material quantitative transfer device for a certain period of time according to the insufficient amount of the insufficient basis weight based on the image data.

Further, it is preferable that the coefficient of variation 1 of the basis weight of the aggregate of discontinuous carbon fibers in the object to be inspected thus obtained or the coefficient of variation 2 of the total basis weight of the deposit is 20% or less. When the coefficient of variation is in the range of 20% or less, the basis weight spots are reduced from the above-mentioned grasp of the basis weight spots in the inspected object and the feedback to the manufacturing process of the aggregate or deposit of discontinuous carbon fibers based on the basis weight spots. It is preferable because the step of controlling the parameters in various manufacturing is rapidly executed. For faster and more reliable execution, the coefficient of variation is more preferably 0.05% or more and 19% or less, and even more preferably 0.1% or more and 18% or less.

The basis weight can be quantified based on the numerical value obtained from the fluoroscopic image of the X-ray and the calibration curve prepared in advance for the basis weight, and the basis weight spot can be inspected. Similar to the method using CT, the size of the spatial average when dealing with the basis weight spot is preferably 1 mm × 1 mm or more and 300 mm × 300 mm or less, more preferably 3 mm × 3 mm or more and 300 mm × 300 mm or less, and 5 mm × Most preferably, it is 5 mm or more and 150 mm × 150 mm or less.

(Inspected body)
The inspected body (inspected body 1, inspected body 2) according to this method is not particularly limited as long as it is a material capable of non-destructive inspection, and various materials and shapes can be used. Here, the inspected body 1 according to the invention of the manufacturing method is defined as an aggregate of discontinuous carbon fibers or a deposit containing a thermoplastic resin and discontinuous carbon fibers, and the inspected body 2 is defined as a discontinuous carbon fiber. Aggregates, deposits containing thermoplastic resin and discontinuous carbon fibers, composites obtained by heating the deposits and impregnating the aggregates of thermoplastic resin with thermoplastic resin, or reheating the composites. It is defined as one of the molding materials that will be the final product that has been molded. That is, the inspected body 2 also shows a composite material and a final product obtained by further processing the composite material with respect to the inspected body 1. In the state of the composite material or the final product, it is possible to measure and inspect the basis weight spots, but it is difficult to perform treatment to reduce the basis weight spots based on the result of the basis weight spots. , In the present invention, both are used properly. The deposit contains thermoplastic resin and carbon fiber. Specifically, a state in which the thermoplastic resin in the form of particles or long fibers or short fibers is dispersed in the space inside the carbon fiber aggregate, or a film made of the thermoplastic resin on at least one surface of the carbon fiber aggregate. It is a concept that includes the state in which the sheet and the non-woven fabric are arranged.

The deposit containing the thermoplastic resin and the discontinuous carbon fibers, which is one aspect of the inspected body 1 or the inspected body 2 used in the present invention, is composed of the above-mentioned aggregate of discontinuous carbon fibers and the thermoplastic resin. A mixture in which the thermoplastic resin is spherical, particulate, pyramidal, columnar, rectangular, pellet-shaped, fibrous or film-shaped, and is a space between aggregates of discontinuous carbon fibers or discontinuous carbon fibers. Represents a composition in which the space between the carbon fibers of the single yarn constituting the above is not sufficiently filled with the thermoplastic resin. Hereinafter, in Production Examples, Examples and the like, one of the forms of the deposit composed of carbon fiber and the thermoplastic resin in the present invention may be referred to as dry mat 1 or dry mat 2. Further, a description of the aggregate of discontinuous carbon fibers will be described later.

Since this method can perform the state of the inspected object non-destructively, efficiently and with high accuracy, for example, a) spots on the aggregate of discontinuous carbon fibers, b) thermoplastic resin and discontinuous carbon fibers are used. Containing spots on the deposits, c) Spots on the composite material by heating the deposits and impregnating the discontinuous carbon fibers with thermoplastic resin, and d) Presence or absence of voids in the molded thermoplastic resin molded product and metal. It is suitable for inspection of the presence or absence of foreign matter such as pieces. That is, this method is suitable for inspection of ceramic materials or resin materials and production of ceramic products and resin products including the inspection. The term "Metsuke spot" as used herein is a concept including a foreign substance such as metal or a void, and is referred to as a basis weight spot in a broad sense. The objects to be inspected in this method include resin materials (thermoplastic resins or thermosetting resins), ceramic materials (inorganic materials other than metals, including glass and carbon materials), fiber reinforced materials, and composites thereof. It is more preferable that the material is at least one selected from the group consisting of. Examples of the fiber reinforced material include a resin material or a material composed of a matrix made of a ceramic material and a reinforcing fiber, and in particular, a composite material which is a fiber reinforced resin composed of a resin material and a reinforcing fiber (for example, glass fiber reinforced heat curing). (Sex resin, glass fiber reinforced thermoplastic resin, carbon fiber reinforced thermocurable resin, or carbon fiber reinforced thermoplastic resin) is preferable. When the object to be inspected contains a fiber reinforced material made of a metal-based material, it goes without saying that the metal pieces detected by the inspection method of the present invention include metal atoms other than the main atoms constituting the fiber reinforced material. It is a piece of metal that contains it.

Here, examples of the resin material include the thermoplastic resins exemplified below, and those resins further containing various additives such as the carbon fibers described below.

The size of the object to be inspected is not particularly limited, but one having a certain width is preferable for the convenience of production. In order to ensure productivity, it is necessary that the length of one side of the object to be inspected is 300 mm or more. It is preferable to use the width direction in which one side is perpendicular to the traveling direction in the process of the object to be inspected at the time of production. The width of the object to be inspected is preferably 300 mm or more, more preferably 500 mm or more, and even more preferably 1000 mm or more. There are no particular restrictions on the shape of the object to be inspected, but a substantially plate shape is preferable because it is easy to inspect. Further, from the viewpoint of productivity and ease of subsequent processing, it is preferable that the length in the width direction and the length direction is sufficiently longer than the length in the thickness direction, that is, a plate shape, a surface shape or a sheet shape. The plate-like, planar or sheet-like shape may have a curved surface in a part thereof. Further, the length (thickness) in the thickness direction is preferably 1.0 mm or more, more preferably 1.5 mm or more and 20 mm or less, and further preferably 1.8 mm or more and 10 mm or less. Further, with respect to these shapes, cotton-like ones such as deposits of discontinuous carbon fibers are laminated, and may have a substantially plate-like shape having some irregularities and curved shapes. However, since X-ray inspection is usually performed in a space where X-rays are shielded, if the device is to be provided with an opening, the height of the opening is constant. It is preferable to keep it within the range. From the above, there is no particular limitation, but when the object to be inspected has a shape in which a plurality of plate-like forms are joined, the height is preferably 500 mm or less, more preferably 300 mm or less.

(Thermoplastic resin)
The thermoplastic resin that may be contained in the object to be inspected used in the present invention is not particularly limited as long as it can obtain a carbon fiber reinforced resin composite material having a desired strength. A thermoplastic resin appropriately selected according to the use of the carbon fiber reinforced resin composite material can be used.

Generally, thermoplastic resins and thermosetting resins are known as typical matrix resins used for fiber-reinforced composite materials. However, in the object to be inspected used in the present invention, a thermoplastic resin can be preferably used as the matrix resin. However, in the object to be inspected used in the present invention, it is also preferable to use the thermosetting resin and the thermoplastic resin in combination as long as the characteristics as the thermoplastic resin are not lost when the matrix resin as a whole is considered. The thermoplastic resin is not particularly limited, and a resin having a desired softening point or melting point can be appropriately selected and used depending on the use of the deposit or the composite material in the present invention.

As the thermoplastic resin that may be contained in the object to be inspected used in this method, a resin having a softening point in the range of 180 ° C. to 350 ° C. is usually used, but is not limited thereto. For example, polyolefin resin (excluding polystyrene resin), polystyrene resin, thermoplastic polyamide resin, polyester resin, polyacetal resin (polyoxymethylene resin), polycarbonate resin, (meth) acrylic resin, polyallylate resin, polyphenylene ether resin, polyimide resin. , Polyether nitrile resin, phenoxy resin, polyphenylene sulfide resin, polysulfone resin, polyketone resin, polyether ketone resin, thermoplastic urethane resin, fluororesin, thermoplastic polybenzoimidazole resin and the like.

Examples of the polyolefin resin include polyethylene resin, polypropylene resin, polybutadiene resin, polymethylpentene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl acetate resin, polyvinyl alcohol resin and the like.

Examples of the polystyrene resin include polystyrene resin, acrylonitrile-styrene resin (AS resin), acrylonitrile-butadiene-styrene resin (ABS resin) and the like.

Examples of the thermoplastic polyamide resin include PA6 (also referred to as polycaproamide, polycaprolactam, and polyε-caprolactam), PA26 (polyethylene adipamide), PA46 (polytetramethylene adipamide), and PA66 (polyhexamethylene). Adipamide), PA69 (polyhexamethylene azepamide), PA610 (polyhexamethylene sebacamide), PA611 (polyhexamethylene undecamide), PA612 (polyhexamethylene dodecamide), PA11 (polyundecaneamide) , PA12 (polydodecaneamide), PA1212 (polydodecamethylene dodecamide), PA6T (polyhexamethylene terephthalamide), PA6I (polyhexamethylene isophthalamide), PA912 (polynonamethylene dodecamide), PA1012 (polydecamethylene dodeca). Mid), PA9T (Polynonamethylene terephthalamide), PA9I (Polynonamethylene isophthalamide), PA10T (Polydecamethylene terephthalamide), PA10I (Polydecamethylene isophthalamide), PA11T (Polyundecamethylene terephthalamide) , PA11I (polyundecamethylene isophthalamide), PA12T (polydodecamethylene terephthalamide), PA12I (polydodecamethylene isophthalamide), polyamide MXD6 (polymethoxylylen adipamide). preferable.

Examples of the polyester resin include polyethylene terephthalate resin, polyethylene naphthalate resin, polytrimethylene terephthalate resin, polytrimethylene naphthalate resin, bolibutylene terephthalate resin, bolibutylene naphthalate resin, and liquid crystal polyester.

Examples of the (meth) acrylic resin include polymethylmethacrylate. Examples of the modified polyphenylene ether resin include modified polyphenylene ether and the like. Examples of the thermoplastic polyimide resin include thermoplastic polyimide, polyamide-imide resin, and polyetherimide resin. Examples of the polysulfone resin include modified polysulfone resin, polyethersulfone resin and the like. Examples of the polyetherketone resin include a polyetherketone resin, a polyetheretherketone resin, and a polyetherketoneketone resin. Examples of the fluororesin include polytetrafluoroethylene and the like.

The thermoplastic resin used in the present invention may contain only one type or two or more types of thermoplastic resin. Examples of the mode in which two or more types of thermoplastic resins are used in combination include a mode in which thermoplastic resins having different softening points or melting points are used in combination, a mode in which thermoplastic resins having different average molecular weights are used in combination, and the like. Can be done, but this is not the case.

(Carbon fiber)
The carbon fiber contained in the subject to be inspected used in the present invention is not particularly limited, but high-strength and high elastic modulus carbon fiber can be used, and one or more of these carbon fibers may be used in combination. Generally, polyacrylonitrile (PAN) carbon fiber, petroleum pitch carbon fiber, coal pitch carbon fiber, rayon carbon fiber, cellulose carbon fiber, lignin carbon fiber, phenol carbon fiber, gas phase growth carbon fiber. However, in the present invention, any of these carbon fibers can be suitably used as the inspected body. Among them, PAN-based, pitch-based, rayon-based and other carbon fibers are preferably mentioned.

Among them, the polyacrylonitrile (PAN) -based carbon fiber is preferable as the carbon fiber contained in the object to be inspected used in the present invention because of its excellent tensile strength. When a PAN-based carbon fiber is used as the carbon fiber, its tensile strength is preferably in the range of 2000 MPa to 10000 MPa, more preferably in the range of 3000 MPa to 8000 MPa. The tensile elastic modulus is preferably in the range of 100 GPa to 600 GPa, more preferably in the range of 200 GPa to 500 GPa, and further preferably in the range of 230 to 450 GPa.

The form of the carbon fiber contained in the object to be inspected used in the present invention is not particularly limited as long as it is a discontinuous fiber.

When the object to be inspected is a carbon fiber reinforced resin composite material and discontinuous fibers are used as the reinforcing fibers, for example, the carbon fibers are arranged in the resin so as to be oriented in a specific one direction or a plurality of directions. Preferable examples include materials, materials in which discontinuous carbon fibers are randomly dispersed and arranged in a two-dimensional in-plane direction, and materials in which discontinuous carbon fibers are randomly arranged in a two-dimensional in-plane direction. Can be done. The carbon fiber contained in the object to be inspected used in the present invention is a discontinuous fiber and may be randomly oriented in a two-dimensional in-plane direction. Here, "randomly oriented in the in-plane direction" means that the carbon fibers are oriented in a disorderly manner in the in-plane direction of the inspected object, not in a specific direction as in one direction, and are generally specific. It refers to the state of being arranged in the seat surface without showing the directionality. When the carbon fibers are randomly oriented in the in-plane direction, it is preferable that the fiber-reinforced resin composite material is a material having no anisotropy in the in-plane direction, that is, a substantially isotropic material. In this case, when the fiber-reinforced resin composite material is prepared, the molding material may be wet-made into a sheet, or the discontinuous carbon fibers are arranged so as to be dispersed and overlapped to form a sheet or a mat (hereinafter referred to as a mat). It may also be called a matte shape).

The carbon fibers contained in the object to be inspected used in the present invention are discontinuous fibers, which are randomly oriented in the in-plane direction in combination (for example, laminated), and are discontinuous carbon fibers in a carbon fiber reinforced resin composite material. May be included.

When discontinuous carbon fiber is used as the carbon fiber contained in the object to be inspected used in the present invention, mechanical properties, surface smoothness of the molded body, surface uniformity, shapeability in the molding mold, and carbon fiber are used. It is preferably applicable because it has an excellent balance of productivity of the reinforced resin composite material. Therefore, the present invention mainly describes the case where the inspected body uses a thermoplastic resin and discontinuous carbon fibers randomly oriented in the in-plane direction.

The fiber length of the discontinuous carbon fiber that may be contained in the object to be inspected used in the present invention has an average fiber length preferably in the range of 1 mm or more, more preferably 1 mm to 100 mm, and even more preferably 3 mm to 3 mm. It is within the range of 90 mm, more preferably 10 mm to 80 m.
It is in the range of m, more preferably in the range of 10 mm to 50 mm, and most preferably in the range of 12 mm to 40 mm. When the inspected body used in this method contains carbon fibers as reinforcing fibers, carbon fibers having an average fiber length within the above range are randomly and randomly in the matrix in the in-plane direction of the inspected body. It is preferable that the fibers are oriented in a (two-dimensional random orientation). The discontinuous carbon fiber in the present invention represents the above-mentioned carbon fiber having an average fiber length of 1 mm to 100 mm.

A mixture of carbon fibers having different fiber lengths of the discontinuous carbon fibers contained in the object to be inspected used in the present invention may be used. In other words, the carbon fiber contained in the inspected body used in the present invention may have a single peak in the distribution of fiber length, or may have a plurality of peaks.

The measurement of the average fiber length of the discontinuous carbon fiber contained in the object to be inspected used in the present invention may be a number average fiber length or a weight average fiber length, but the one having a long fiber length is emphasized. It is preferable to measure with the weight average fiber length calculated as described above. Assuming that the fiber length of each carbon fiber is Li and the number of measured fibers is j, the number average fiber length (Ln) and the weight average fiber length (Lw) are calculated by the following mathematical formulas (1-1) and (1-2). Desired.
Ln = ΣLi / j ・ ・ ・ (1-1)
Lw = (ΣLi ² ) / (ΣLi) ・ ・ ・ (1-2)

If the reinforcing fiber contained in the object to be inspected is a continuous fiber cut with a rotary cutter and the fiber length of the reinforcing fiber is a certain length, the number average fiber length and the weight average fiber length are the same. Become a value. When a carbon fiber reinforced resin which is an in-plane isotropic base material is obtained by a method as described later using such cut carbon fibers, the average fiber length of the carbon fibers in the in-plane isotropic base material is Approximately equal to the average fiber length at the time of cutting.

Extraction of carbon fibers from the deposit or composite material is performed, for example, by subjecting the deposit or composite material to heat treatment at about 500 ° C. for about 1 hour in a furnace and removing the resin in the furnace. Can be done.

The average fiber diameter of the carbon fibers is usually preferably in the range of 3 μm to 50 μm, more preferably in the range of 3.5 μm to 20 μm, and further preferably in the range of 4.0 μm to 12 μm. It is more preferably in the range of 4.5 μm to 10 μm, particularly preferably in the range of 5.0 μm to 8.0 μm, and most preferably in the range of 5.5 μm to 7.0 μm. preferable. The preferable range of the average fiber diameter of the carbon fiber may be a combination of the lower limit value of each of the above ranges and the upper limit value of another range, and an example thereof is 4.5 μm to 20 μm.

Here, the average fiber diameter is assumed to indicate the diameter of a single yarn of carbon fiber. Therefore, when the carbon fiber is in the form of a fiber bundle, it refers to the diameter of the carbon fiber (single yarn) constituting the fiber bundle, not the diameter of the fiber bundle. The average fiber diameter of the carbon fibers can be measured, for example, by the method described in JIS R-7607: 2000.

The carbon fiber contained in the object to be inspected used in the present invention may be only a single thread-like one, a fiber bundle-like one, or a mixture of both. When a fiber bundle is used, the number of single yarns constituting each fiber bundle may be substantially uniform or different in each fiber bundle. In the present invention, the aggregate of discontinuous carbon fibers, which is one aspect of the object to be inspected, is a collection of one or two or more carbon fiber bundles, or one or two or more carbon fiber bundles. Further, it may contain one or two or more single-thread-shaped carbon fibers.

When the carbon fibers constituting the aggregate of discontinuous carbon fibers contained in the object to be inspected used in the present invention are in the form of fiber bundles, the number of single yarns constituting each fiber bundle is not particularly limited. Usually, it is in the range of 1000 to 100,000.

Generally, carbon fibers are in the form of fiber bundles in which thousands to tens of thousands of filaments are aggregated. When a carbon fiber bundle is used as the carbon fiber, if the carbon fiber bundle is used as it is, the entanglement portion of the fiber bundle becomes thick locally, and it may be difficult to obtain a thin-walled deposit or a composite material. Therefore, when a carbon fiber bundle is used as the carbon fiber, it is usual to widen or open the carbon fiber bundle.

When the carbon fiber bundle is opened and used, the degree of opening of the fiber bundle after opening is not particularly limited, but the degree of opening of the carbon fiber bundle is controlled and the fiber bundle is composed of a specific number or more. It is preferable to contain a carbon fiber bundle and a carbon fiber (single yarn) or a carbon fiber bundle less than that. In this case, specifically, a carbon fiber bundle (hereinafter referred to as a carbon fiber bundle (A)) composed of a critical single yarn number or more defined by the following mathematical formula (2) and other defibrated fibers. It is preferably composed of carbon fibers, that is, fiber bundles composed of a single yarn state or less than the critical number of single yarns.
Number of critical single yarns = 600 / D ... (2)
(Here, D is the average fiber diameter (μm) of the carbon fiber)

Specifically, when the average fiber diameter of the carbon fibers constituting the aggregate of discontinuous carbon fibers is 5 to 7 μm, the number of critical single yarns defined in the above formula (1) is 86 to 120. When the average fiber diameter of the carbon fibers is 5 μm, the average number of fibers in the carbon fiber bundle (A) is in the range of 240 to less than 4000, but more preferably 300 to 2500. More preferably, it is 400 to 1600. When the average fiber diameter of the carbon fibers is 7 μm, the average number of fibers in the carbon fiber bundle (A) is in the range of 122 to 2040, but more preferably 150 to 1500 fibers, more preferably 200. ~ 800 pieces.

Further, in the inspected body used in the present invention, the ratio of the carbon fiber bundle (A) to the total amount of carbon fibers in the inspected body is preferably more than 0 Vol% and 99 Vol% or less, and 20 Vol% or more and less than 98 Vol. More preferably, it is more preferably 30 Vol% or more and less than 95 Vol%, particularly preferably 30 Vol% or more and 90 Vol% or less, and most preferably 50 Vol% or more and less than 85 Vol%. By coexisting a carbon fiber bundle composed of a specific number or more of carbon fibers and other opened carbon fibers or carbon fiber bundles at a specific ratio in this way, the abundance of carbon fibers in the inspected object can be determined. That is, it is possible to increase the fiber volume content (Vf).

The degree of opening of the carbon fiber can be within the target range by adjusting the opening conditions of the fiber bundle. For example, when the fiber bundle is opened by blowing a gas such as air on the fiber bundle, the degree of opening can be adjusted by controlling the pressure of the air blown on the fiber bundle. In this case, by increasing the air pressure, the degree of fiber opening is high (the number of single threads constituting each fiber bundle is small), and by reducing the air pressure, the degree of fiber opening is low (constituting each fiber bundle). There is a tendency for the number of single threads to be increased).

In the object to be inspected used in the present invention, the average number of fibers (N) in the carbon fiber bundle (A) can be appropriately determined within a range that does not impair the object of the present invention, and is not particularly limited. .. N is usually in the range of 1 <N <12000, but it is more preferable to satisfy the following mathematical formula (3).
0.6 × 10 ⁴ / D ² <N <6 × 10 ⁵ / D ² ... (3)
(Here, D is the average fiber diameter (μm) of the carbon fiber)

When the average number of fibers (N) in the carbon fiber bundle (A) satisfies the above range, a high fiber volume content (Vf) can be easily obtained, and depending on the manufacturing method, the carbon fiber reinforced resin composite material The flatness is good. When N is larger than 0.6 × 10 ⁴ / D ² , it is easy to obtain a high fiber volume content (Vf), which is preferable. Further, when the average number of fibers (N) in the reinforcing fiber bundle (A) is less than 6 × 10 ⁵ / D ² , especially less than 1 × ¹⁰⁵ , in the unimpregnated precursor or the carbon fiber reinforced resin composite material which is the final product. It is preferable that a thick portion is less likely to occur locally and void formation is suppressed.

Composite materials containing carbon fibers, especially carbon fiber reinforced resins, are lightweight and have excellent mechanical properties such as tensile strength and tensile elastic modulus, and are preferable for various applications. However, since the high cost of using carbon fiber is an obstacle to its adoption in various applications, extreme cost reduction is required from the raw material of carbon fiber to the manufacturing method. Therefore, in the present invention, when the carbon fiber composite material, particularly the carbon fiber reinforced resin, is the inspected object, it is assumed that the quality requirements are not satisfied or the quality requirements are not satisfied from the numerical values of the grain and the spots. It is suitable because carbon fiber aggregates, deposits and composite materials can be eliminated before the final manufacturing process. In particular, among the carbon fiber reinforced resins, the in-plane isotropic base material in which the carbon fibers, which are discontinuous fibers, are two-dimensionally randomly oriented and contained in the thermoplastic resin as the matrix resin is highly practical. Therefore, the present invention is suitable for the production of an in-plane isotropic base material, the production of a molded product using the same, and the inspection of intermediates in the process at that time. Such in-plane isotropic substrates and methods for manufacturing them include US Pat. No. 8,946,342, US Pat. No. 8,829,103, US Pat. No. 9,193,840, US Pat. No. 9, Examples are those described in 545,760, US Patent Application Publication No. 2015-02922145, and the like.

Here, if it is desired to define particularly strictly and numerically that the reinforcing fiber such as carbon fiber has a two-dimensional random orientation in the inspected body, it is shown in Japanese Patent No. 5,944,114. As shown above, with respect to the reinforcing fibers, the plane orientation σ defined by 1- (the number of reinforcing fibers having a plane orientation angle γ of 10 ° or more) / (total number of reinforcing fibers)) is 90. A state of% or more may be a preferable two-dimensional random orientation.

(Composition ratio)
When the inspected body 1 or the inspected body 2 used in the present invention is a deposit or a composite material containing a thermoplastic resin, the abundance of the thermoplastic resin or the thermosetting resin is determined by the type of these resins and carbon fibers. The resin can be appropriately determined according to the type and the like, and is not particularly limited, but is usually in the range of 3 parts by mass to 1000 parts by mass of the resin with respect to 100 parts by mass of the carbon fiber. The resin is preferably in the range of 10 to 900 parts by mass with respect to 100 parts by mass of carbon fiber, more preferably 20 to 400 parts by mass with respect to 100 parts by mass of carbon fiber, and further preferably carbon fiber. The amount of the resin is 50 to 100 parts by mass with respect to 100 parts by mass.

The volume ratio (fiber volume content (Vf)) of the carbon fiber contained in the inspected body defined by the following formula (4) is the volume (carbon) of the inspected body in the inspected body used in the present invention. 55% by volume or less is preferable based on the total amount of fibers + total amount of thermoplastic resin). It is more preferably in the range of 15 to 45%, and even more preferably in the range of 25 to 40%. When the fiber volume content of the carbon fiber is 15% or more, the reinforcing effect due to the content is sufficiently exhibited, which is preferable. Further, if it is 55% or less, voids are less likely to occur in the composite material or the final product (hereinafter referred to as composite material or the like) obtained after molding, although it depends on the molding method, and the physical properties of the composite material or the like are improved. preferable.
Vf = 100 x carbon fiber volume / (carbon fiber volume + thermoplastic resin volume) ... (4)

Further, in the inspected body used in the present invention, when the carbon fibers are randomly oriented in the in-plane direction, the volume content (Vf) of the carbon fibers in the composite material or the like is 10 to 70 Vol%. It is also preferable to have. When the volume content of the carbon fiber in the composite material or the like is 10 Vol% or more, it is preferable that the desired mechanical properties can be easily obtained. On the other hand, when it is 70 Vol% or less, the fluidity of the thermoplastic resin does not decrease when the composite material or the like is produced, and it is easy to obtain a desired shape at the time of molding, which is preferable. A more preferable range of the volume content of the reinforcing fiber in the composite material or the like is 20 to 60 Vol%, and a more preferable range is 30 to 50 Vol%.

(Orientation of carbon fiber)
In the present invention, the discontinuous carbon fibers in the composite material or the like should have a two-dimensional random orientation in which the major axis direction of the fibers is randomly oriented in the two-dimensional direction in the in-plane direction of the composite material or the like. The above-mentioned composite material or the like in which carbon fibers are two-dimensionally randomly oriented is excellent in isotropic properties in the in-plane direction, and is suitable for obtaining a composite material or the like having a complicated shape portion such as unevenness.

The orientation mode of the carbon fibers in the above-mentioned composite material or the like is measured after performing a tensile test based on, for example, an arbitrary direction of the above-mentioned composite material or the like and a direction orthogonal to the direction, and measuring the tensile elastic modulus. It can be confirmed by measuring the ratio (Eδ) obtained by dividing a large value of the tensile elastic modulus by a small value. The closer the ratio of the tensile elastic modulus of the composite material or the like is to 1, the more the carbon fibers are randomly oriented in the in-plane direction, in other words, the two-dimensional random orientation, and the composite material or the like is isotropic in the plane. It can be evaluated as. For example, if Eδ is less than 2, it is in-plane isotropic, if Eδ is 1.5 or less, it is excellent in in-plane isotropic, and if Eδ is 1.3 or less, it is in-plane. It can be said that it is extremely excellent in isotropic properties.

The orientation state in the composite material or the like used in the present invention is preferably the above-mentioned two-dimensional random orientation, but it deviates from the object of the present invention or the mechanical properties of the composite material or the like used in the present invention. As long as it does not affect the formability, there may be a portion oriented in one direction. Further, it may be an irregular orientation between the one-way orientation and the two-dimensional random orientation (the orientation state in which the major axis direction of the reinforcing fiber is not completely unidirectional and is not completely random). Further, depending on the fiber length of the carbon fiber, the long axis direction of the carbon fiber may be oriented so as to have an angle with respect to the in-plane direction of the composite material or the like, and the carbon fibers may be oriented so as to be entangled in a cotton-like manner. Further, the carbon fibers may be oriented such as bidirectional fabrics such as plain weave and twill weave, multiaxial fabrics, non-woven fabrics, mats, knits, braids, and paper made from carbon fibers.

(Additive)
As described above, the composite material or the like used in the present invention contains at least carbon fibers and a thermoplastic resin or a thermosetting resin, but various types are required as long as the object of the present invention is not impaired. Additives may be included. The various additives are not particularly limited as long as they can impart desired functions or properties to the composite material or the like, depending on the intended use.

Various additives that may be contained in the subject to be inspected used in the present invention include, for example, melt viscosity reducing agents, antistatic agents, pigments, softeners, plasticizing agents, surfactants, conductive particles, fillers, and carbon black. , Coupling agent, foaming agent, lubricant, corrosion inhibitor, crystal nucleating agent, crystallization accelerator, mold release agent, stabilizer, ultraviolet absorber, colorant, anticoloring agent, antioxidant, flame retardant, flame retardant Auxiliary agents, anti-drip agents, lubricants, fluorescent whitening agents, phosphorescent pigments, fluorescent dyes, flow modifiers, inorganic and organic antibacterial agents, insect repellents, photocatalytic antifouling agents, infrared absorbers, photochromic agents, etc. be able to.

(Manufacturing of composite materials containing discontinuous carbon fiber)
In the present invention, the above-mentioned carbon fiber reinforced composite is used for manufacturing a composite material using the above-mentioned aggregate of discontinuous carbon fibers and a deposit made of a thermoplastic resin as a material, and further manufacturing a final product based on the composite material. It can be manufactured by applying the usual processing methods in the field of materials. A typical manufacturing method includes a press molding method (cold press molding method, hot press molding method), but there are also injection molding method, injection compression molding method, extrusion molding method, insert molding method, and in-mold coating molding method. Etc. can also be used. Specifically, in producing a composite material, any of the above molding methods is applied to the above deposits, and at least a part of the thermoplastic resin constituting the deposit is aggregated with discontinuous carbon fibers. A composite material can be produced by impregnating the body. In this case, impregnation of the thermoplastic resin into the aggregate of discontinuous carbon fibers means that when the thermoplastic resin is arranged so as to fill the space between the discontinuous carbon fibers, it constitutes a discontinuous carbon fiber aggregate. Includes both cases where the continuous carbon fibers are arranged to fill the space between the single yarns. Hereinafter, in Production Examples, Examples and the like, one of the forms of the composite material in the present invention may be referred to as an impregnated base material n (n = 1 to 3). The composite material corresponds to the concept of deposits in the present invention, which is obtained by heat-molding the above-mentioned dry mat.

Examples are shown below, but the present invention is not limited thereto. In addition, Example 1-2, Example 1-3, Example 2-1, Example 2-2, Example 2-3, Example 3-1, Example 3-2, and Example 3-3. Reference Example 1-2, Reference Example 1-3, Reference Example 2-1, Reference Example 2-2, Reference Example 2-3, Reference Example 3-1 and Reference Example 3-2, and Reference Example 3-, respectively. It shall be read as 3. Each value in this example was obtained according to the following method.
1) Calculation of the ratio of the carbon fiber bundle (A) in the fiber-reinforced resin material The method of calculating the ratio of the carbon fiber bundle (A) contained in the fiber-reinforced resin material is as follows. The fiber-reinforced resin material is cut into a size of 50 mm × 50 mm, heated in a furnace at 500 ° C. for about 1 hour to completely remove the thermoplastic resin, and then all the fiber bundles are taken out with a tweezers to lengthen the fiber bundles ( Li), mass (Wi), and number of fiber bundles (I) were measured. For those whose fiber bundles were so small that they could not be taken out with tweezers, the mass was measured at the end (Wk). A balance capable of measuring up to 1/100 mg is used for measuring the mass.

After the measurement, the following calculation was performed. From the fineness (F) of the carbon fibers used, the number of fibers (Ni) of each fiber bundle was calculated by the following formula.
Number of fibers (Ni) = Wi / (Li × F) ・ ・ ・ (5)
The average number of fibers (N) in the carbon fiber bundle (A) was calculated by the following formula.
N = ΣNi / I ・ ・ ・ (6)
The volume ratio (VR) of the carbon fiber bundle (A) to the entire reinforcing fiber was calculated by the following formula using the carbon fiber density (ρ).
VR = Σ (Wi / ρ) × 100 / ((Wk + ΣWi) / ρ) ・ ・ ・ (7)

2) Weight average carbon fiber length of reinforcing fibers The average fiber length of reinforcing fibers is the fiber length of 100 reinforcing fibers randomly selected after completely removing the thermoplastic resin from the fiber reinforced resin material by the above operation. Was measured up to 1 mm unit with a fiber shaving or the like. Generally, assuming that the fiber length of each reinforcing fiber is Li, the number average fiber length Ln and the weight average fiber length Lw in the fiber-reinforced resin material can be obtained by the following mathematical formulas (1-1) and (1-2). The units of the number average fiber length Ln and the weight average fiber length Lw are both mm.
Ln = ΣLi / I ... (1-1)
Lw = (ΣLi ² ) / (ΣLi) ・ ・ ・ (1-2)
Here, "I" represents the number of carbon fibers whose fiber length is measured.

3) Analysis of carbon fiber orientation in prepreg After producing the prepreg, as a method of measuring the isotropic property of carbon fibers, a tensile test is performed based on an arbitrary direction of the molded plate and a direction orthogonal to the direction. The tensile elastic modulus was measured, and the ratio (Eδ) obtained by dividing the large value of the measured tensile elastic modulus by the small one was measured. The closer the ratio of tensile elastic modulus is to 1, the better the isotropic property. Specifically, if Eδ is less than 2, the in-plane isotropic property, that is, the two-dimensional random orientation is used. The molded plate for analyzing the fiber orientation in the examples was molded under the same conditions as those for producing the prepreg in the examples.

4) Analysis of type of thermoplastic resin For the type of thermoplastic fiber (primary structure), ¹ H-NMR measurement (JEOL A-600 type manufactured by JEOL Ltd.) is performed on the sampled minute pieces, and the spectrum chart is analyzed. Identified by.
5) Measurement and evaluation of the length of the object to be inspected Measured with a tape measure having a scale in units of 1 mm.

[Manufacturing Example 1]
-Manufacture of mixed dry mat of carbon fiber and resin (hereinafter referred to as dry mat 1) Carbon fiber "Tenax" (registered trademark) STS40-24KS (registered trademark) manufactured by Toho Tenax Co., Ltd. cut to an average fiber length of 20 mm as carbon fiber. Using an average fiber diameter of 7 μm) and using nylon 6 resin A1030 manufactured by Unitika Co., Ltd., which is a thermoplastic resin as a matrix resin, carbon fiber is added with reference to the method described in the WO2012 / 105080 pamphlet. A dry mat 1 in which carbon fibers aiming at 1500 g / m ² and a nylon resin grain of 2100 g / m ² were randomly dispersed (two-dimensionally randomly oriented) in the in-plane direction was prepared.

Specifically, a metal alloy slitter was placed and slit in the carbon fiber splitting device. A metal alloy cutter was used as the cutting device, and the pitch of the blade was adjusted so that the carbon fiber was cut to a fiber length of 20 mm.

The strands that passed through the cutter were introduced into the transport pipe located directly under the cutter, which was subsequently introduced into the defibration equipment. As a fiber-spreading device, a tube was manufactured and used. Compressed air was blown into the tube for fiber opening.

Particulate thermoplastic resin (nylon 6 resin) was supplied from the side surface of the tube. Then, a breathable support (hereinafter referred to as a fixing net) that moves in a certain direction is installed at the bottom of the pipe outlet, suction is performed from below with a blower, and a flexible transport pipe is placed on the fixing net. And while reciprocating the above pipe in the width direction, a mixture of cut carbon fiber and nylon resin was deposited in a band shape. Then, the supply amount of the reinforcing fiber and the supply amount of the matrix resin were set, and the apparatus was operated to obtain a dry mat 1 having a size of 1000 mm × 500 mm in which the reinforcing fiber and the thermoplastic resin were mixed on the fixing net.

[Manufacturing Example 2]
-Manufacture of carbon fiber reinforced resin impregnated base material The dry mat 1 obtained in Production Example 1 was heated and compressed for 15 minutes in an impregnation device heated to 260 ° C. to obtain an impregnated base material 1 having a thickness of 2.6 mm. rice field.

[Manufacturing Example 3]
-Manufacturing a partially impregnated base material of carbon fiber reinforced resin With reference to Production Example 2, an impregnated base material was prepared by the same method except that the heating time was 10 minutes, the compression conditions were changed, and the basis weight spots were changed. , An impregnated base material 2 having a thickness of 2.6 mm was obtained.

[Manufacturing Example 4]
-Manufacturing of an impregnated base material in which a metal piece is embedded in a carbon fiber reinforced resin Production example except that an aluminum piece of 30 mm × 30 mm × 0.5 mm was embedded in the process of depositing the mixture of Production Example 1. Using the dry mat obtained by the same method as in No. 1, an impregnated base material was prepared by the same method as in Production Example 2 to obtain an impregnated base material 3 having a thickness of 2.6 mm.

[Manufacturing Example 5]
-Manufacturing of carbon fiber dry mat (hereinafter referred to as dry mat 2) With reference to Production Example 1, one non-woven thermoplastic resin is placed on the lower surface of the carbon fiber instead of supplying the particulate thermoplastic resin. A dry mat was prepared in the same manner as in Production Example 1 except that the dry mat 2 was obtained.

○ Example using the phase analysis method of infrared image [Example 1-1]
-Metsuke and Metsuke Spot Inspection of Impregnated Base Material The impregnated base material 1 obtained in Production Example 2 is conveyed in the long direction of the impregnated base material 1 by a belt conveyor, and the impregnated base material 1 (hereinafter referred to as a material). In some cases), the infrared rays emitted from the material were captured and analyzed using the method of phase analysis. Specifically, the material was heated while being conveyed by a belt conveyor (conveying speed of 1 m / min), and the radiation of infrared rays from the heated material being conveyed was detected. For heating, a fiber laser (output: 1.5 kW) manufactured by Laserline Co., Ltd. and a collimator that expands the laser to a width of 500 mm were used. An infrared camera (640 x 512 pixel area sensor) from FLIR was used for infrared detection, and an image was analyzed using infrared phase analysis simulation software for the effective inspection unit of the moving image obtained by the infrared camera. .. At this time, the infrared camera was placed at a position facing the position of the fiber laser, which is a heating device, with respect to the material. The temperature amplitude of the infrared camera used was a camera with a resolution of 0.05 deg C (° C.). This step was repeated, and the entire material having a size of 1000 mm × 500 mm was inspected in a direction having a width of 500 mm and a length of 100 mm. The phase image information of the obtained material was partitioned by 50 mm × 50 mm, the spatial mean value was calculated, and it was quantified and drawn. At this time, the time required for the phase analysis was less than 5 minutes. As a result of the inspection, when the basis weight of each of the 20 portions of the 50 mm × 50 mm section of the base material was calculated, it was confirmed that 150 g / m ² or more could be detected as the basis weight spot.

[Example 1-2]
-Inspection of voids in the impregnated base material The inspection was performed using the same method as in Example 1-1, except that the impregnated base material 2 obtained in Production Example 3 was used.
As a result of the inspection, it was confirmed that the voids that were not partially impregnated could be detected.

[Example 1-3]
-Inspection of metallic foreign matter on the impregnated base material The inspection was performed using the same method as in Example 1-1 except that the impregnated base material 3 obtained in Production Example 4 was used.
As a result of the inspection, it was confirmed that the buried aluminum piece could be detected.

[Example 1-4]
-Metsuke inspection of mixed dry mat of carbon fiber and resin An inspection was performed using the same method as in Example 1-1 except that the dry mat 1 obtained in Production Example 1 was used.
As a result of the inspection, when the basis weight of each of the 200 parts of the 50 mm × 50 mm section of the base material was calculated, it was confirmed that 150 g / m ² or more could be detected as the basis weight spot.

[Example 1-5]
-Metsuke inspection of carbon fiber dry mat The inspection was performed using the same method as in Example 1-1 except that the dry mat 2 obtained in Production Example 5 was used.
As a result of the inspection, when the basis weight of each of the 200 parts of the 50 mm × 50 mm section of the base material was calculated, it was confirmed that 150 g / m ² or more could be detected as the basis weight spot.

○ Example of image analysis of X-ray CT [Example 2-1]
-Metsuke and Metsuke Spot Inspection of Impregnated Base Material The impregnated base material 1A (100 mm x 300 mm), which is created by the same method as in Production Example 2 and differs only in dimensions, is oriented toward an X-ray CT apparatus having a width of 300 mm and a length of 100 mm. It was placed in and the inspection analysis was performed. Specifically, an X-ray CT apparatus equipped with an area sensor manufactured by Nikon Instec Co., Ltd. (MCT225, an imaging condition in which the spatial average of the digital values of the effective inspection area is about 55% of the sensor limit value) was used. As the wavelength of X-rays, a wavelength band having an intensity peak of X-rays in the range of 0.1 × 10 ^-10 to 0.2 × 10 ^-10 m was used, and the Voxel size was 120 μm. The effective inspection part of the tomographic image data obtained by X-ray CT was image-analyzed using VGstudio manufactured by Volume Graphics, and the image information of the obtained material was divided into 50 mm × 50 mm and the spatial average value. Was calculated to obtain the digitized and drawn data.
As a result of the inspection, when the basis weight of each of the 12 portions of the 50 mm × 50 mm section of the base material was calculated, it was confirmed that 100 g / m ² or more could be detected as the basis weight spot.

[Example 2-2]
Void inspection of impregnated base material The same method as in Example 2-1 except that the impregnated base material 2A (100 mm × 300 mm), which is prepared by the same method as in Production Example 3 and differs only in dimensions, is used for inspection. Was inspected using.
As a result of the inspection, it was confirmed that the voids partially existing inside the material could be detected.

[Example 2-3]
-Inspection of metallic foreign matter on impregnated base material The same as in Example 2-1 except that the impregnated base material 3A (100 mm x 300 mm), which is prepared by the same method as in Production Example 4 and differs only in dimensions, is used for inspection. Inspected using the technique.
As a result of the inspection, it was confirmed that the buried aluminum piece could be detected.

[Example 2-4]
Metsuke inspection of mixed dry mat of carbon fiber and resin A dry mat 1A (100 mm × 300 mm) prepared by the same method as in Production Example 1 and different only in size was placed in an X-ray CT apparatus and inspected and analyzed. Specifically, an X-ray CT apparatus (Stella Scan AX) equipped with an area sensor manufactured by Rigaku Co., Ltd. was used. As the wavelength of X-rays, a wavelength band having an intensity peak of X-rays in the range of 0.5 × 10 ^-10 to 0.6 × 10 ^-10 m was used. Image analysis software is used to analyze the image of the effective inspection unit of the image obtained by X-ray CT, and the image information of the obtained material is divided into 50 mm × 50 mm to calculate the spatial mean value and numerical value. The converted and drawn data was obtained.
As a result of the inspection, when the basis weight of each of the 12 portions of the 50 mm × 50 mm section of the base material was calculated, it was confirmed that 100 g / m ² or more could be detected as the basis weight spot.

[Example 2-5]
-Metsuke inspection of carbon fiber dry mat Dry mat 2A (100 mm x), which is created by the same method as in Production Example 5 and differs only in dimensions.
300 mm) was inspected using the same method as in Example 2-4, except that it was used for the inspection.
As a result of the inspection, when the basis weight of each of the 12 portions of the 50 mm × 50 mm section of the base material was calculated, it was confirmed that 100 g / m ² or more could be detected as the basis weight spot.
The data of this basis weight spot was fed back to the manufacturing process. The supply amount of carbon fiber was adjusted for the parts where the basis weight was insufficient for the target basis weight. When the carbon fiber mixed dry mat that had undergone this adjustment was confirmed again in the same grain inspection step, a carbon fiber dry mat having a coefficient of variation of 1 of 12% (coefficient of variation before adjustment of 25%) was obtained.

○ Example of fluoroscopic image analysis of X-rays [Example 3-1]
-Metsuke and Metsuke Spot Inspection of Impregnated Base Material The impregnated base material 1 obtained in Production Example 2 is conveyed in the long direction of the impregnated base material 1 by a belt conveyor, and the impregnated base material 1 is irradiated with X-rays. The X-rays transmitted through the impregnated substrate 1 were captured by a line sensor and analyzed using the X-ray fluoroscopic image. Specifically, it is transported by IAI's Robo cylinder (conveyance speed 1.5 m / min), and is transported by Softex's X-ray generator (intensity peak wavelength band: 1.5 x ^10-10 to 1.6 x. ^10-10 m, imaging conditions where the spatial average of the digital value of the effective inspection area is about 60% of the sensor limit value) and an X-ray line sensor from Imagetech (0.4 mm resolution, sensor gain is 1x) are used. Then, an X-ray fluoroscopic image was taken and image analysis was performed using ImageJ manufactured by NIH and software manufactured in Teijin Co., Ltd.
By this step, the inspection of the entire material having a size of 1000 mm × 500 mm was performed in a direction having a width of 500 mm and a length of 100 mm. The image information of the obtained material was partitioned by 50 mm × 50 mm, the spatial mean value was calculated, and it was quantified and drawn.
As a result of the inspection, when the basis weight of each of the 200 parts of the 50 mm × 50 mm section of the base material was calculated, it was confirmed that 100 g / m ² or more could be detected as the basis weight spot.

[Example 3-2]
-Void inspection of impregnated base material The impregnated base material 2 prepared by the same method as in Production Example 3 is subjected to an X-ray generator of Kinki Roentgen Co., Ltd. (wavelength band of intensity peak: 0.8 × ^10-10 to 0.9. Using the same method as in Example 3-1 except that the imaging condition) of × ^10-10 m, where the spatial average of the digital values of the effective inspection area is about 20% of the sensor limit value) is used for the inspection. Inspected.
As a result of the inspection, it was confirmed that the voids that were not partially impregnated could be detected.

[Example 3-3]
-Inspection of metallic foreign matter on the impregnated base material The impregnated base material 3 prepared by the same method as in Production Example 4 was inspected using the same method as in Example 3-2 except that it was used for the inspection.
As a result of the inspection, it was confirmed that the buried aluminum piece could be detected.

[Example 3-4]
Metsuke inspection of mixed dry mat of carbon fiber and resin For dry mat 1 created by the same method as in Production Example 1, the imaging conditions are such that the spatial average of the digital values of the effective inspection area is about 25% of the sensor limit value. The inspection was performed using the same method as in Example 3-1 except that it was used for the inspection.
As a result of the inspection, when the basis weight of each of the 200 parts of the 50 mm × 50 mm section of the base material was calculated, it was confirmed that 100 g / m ² or more could be detected as the basis weight spot.

[Example 3-5]
Metsuke inspection of mixed dry mat of carbon fiber and resin For dry mat 1 created by the same method as in Production Example 1, the imaging conditions are such that the spatial average of the digital values of the effective inspection area is about 60% of the sensor limit value. The inspection was performed using the same method as in Example 3-4 except that it was used for the inspection.
As a result of the inspection, when the basis weight of each of the 200 parts of the 50 mm × 50 mm section of the base material was calculated, it was confirmed that 100 g / m ² or more could be detected as the basis weight spot.
The data of this basis weight spot was fed back to the manufacturing process. The supply amount of carbon fiber and resin was adjusted for the parts where the basis weight was insufficient for the target basis weight. When the carbon fiber and resin mixed dry mat that had undergone this adjustment was confirmed again in the same grain inspection process, the carbon fiber and resin mixed dry mat had a coefficient of variation of 18% (coefficient of variation before adjustment 32%). Got

[Example 3-6]
-Grade inspection of mixed dry mat of carbon fiber and resin A numerical value based on the relative exposure amount of X-rays received by amplifying the sensor gain of the dry mat 1 created by the same method as in Production Example 1 twice. The test was performed using the same procedure as in Example 3-5, except that the data was amplified 2.0 times.
As a result of the inspection, when the basis weight of each of the 200 parts of the 50 mm × 50 mm section of the base material was calculated, it was confirmed that 100 g / m ² or more could be detected as the basis weight spot. In addition, the life of the tube of the X-ray generator has been increased by at least 10%.

[Example 3-7]
-Metsuke inspection of carbon fiber dry mat The dry mat 2 prepared by the same method as in Production Example 5 was inspected by the same method as in Example 3-5 except that it was used for the inspection.
As a result of the inspection, when the basis weight of each of the 200 parts of the 50 mm × 50 mm section of the base material was calculated, it was confirmed that 100 g / m ² or more could be detected as the basis weight spot.

[Example 3-8]
-Metsuke inspection of carbon fiber dry mat A dry mat 1A (100 mm x 300 mm) prepared by the same method as in Production Example 1 and different only in size was placed in an X-ray transmission device and inspected and analyzed. Specifically, an X-ray transmission device equipped with an area sensor manufactured by Rigaku (Stella Scan AX also serves as an X-ray CT function. Imaging conditions in which the spatial average of the digital values of the effective inspection area is about 20% of the sensor limit value. )It was used. As the wavelength of X-rays, a wavelength band having an intensity peak of X-rays in the range of 0.8 × 10 ^-10 to 0.9 × 10 ^-10 m was used. Image information of the obtained material is divided into 5 mm × 5 mm and the spatial mean value is calculated for the effective inspection part of the image obtained by X-ray transmission imaging using ImageJ manufactured by NIH and software manufactured in Teijin Co., Ltd. Then, the image was analyzed, and as a result, the digitized and drawn data were obtained.
As a result of the inspection, when the basis weight of each of the 1200 5 mm × 5 mm sections of the base material was calculated, it was confirmed that 200 g / m ² or more could be detected as the basis weight spot.

[Comparative Example 1]
When the dry mat 1 obtained in Production Example 1 was cut into a size of 25 mm × 25 mm and the basis weight was measured with an electronic balance, the basis weight was 180 g / m ² at the maximum, so that there was no problem. However, because the material was cut into small pieces, it was not possible to produce a composite material of the desired size.

According to the present invention, it is possible to inspect the presence or absence of foreign matter inside the material, the presence or absence of voids inside the material, and the quantitative inspection of slight basis weight spots in the material, and by going through the inspection step, the basis weight spots can be inspected. It is possible to provide a method for producing a carbon fiber composite material in which the amount of carbon fiber is suppressed or reduced. Its significance is extremely great in the future industries that manufacture and use carbon fiber reinforced resin composite materials.

Claims (15)

A method for producing a deposit containing a thermoplastic resin and an aggregate of discontinuous carbon fibers, wherein the length of one side of the deposit is 300 mm or more, and the deposit is produced through the following steps.
Step 101: If the deposit is in a state where a film, sheet, or non-woven fabric made of a thermoplastic resin is arranged on at least one surface of the aggregate of the discontinuous carbon fibers, the aggregate of the discontinuous carbon fibers. If the texture of the body [g / m ² ] is such that the deposit is a state in which particulate or long fiber or short fiber thermoplastic resin is dispersed in the space in the aggregate of the discontinuous carbon fibers. Inspection step for non-destructively inspecting the grain [g / m ² ] of the deposit (the aggregate of discontinuous carbon fibers or the deposit whose grain is non-destructively inspected is hereinafter referred to as the inspected body 1. .)
Step 201: A step of grasping the basis weight spots of the inspected body 1 based on the inspection result of the step 101.
Step 301: When the aggregate of the discontinuous carbon fibers is the inspected body 1 based on the spots on the eyes in the step 201, the spots on the eyes are reduced at the insufficient spots in the aggregates of the discontinuous carbon fibers. When the deposit is the object 1 to be inspected, the discontinuous carbon fiber is added so as to be performed, and the discontinuous carbon is added according to the amount of the deficiency so as to reduce the blemishes on the deficient spots of the deposit. The process of adding fibers and / or thermoplastic resin.
The method for producing a deposit according to claim 1, further comprising the following step 202 after the step 201.
Step 202: A step of feeding back the data of the basis weight spots of the inspected body 1 obtained in the step 201 to the step of manufacturing the inspected body 1. The invention according to claim 1 or 2, wherein at a time point after the step 301, the coefficient of variation 1 of the basis weight of the aggregate of the discontinuous carbon fibers or the coefficient of variation 2 of the total basis weight of the deposit is 20% or less. How to make deposits. The method for producing a deposit according to any one of claims 1 to 3, wherein an infrared ray emitted from the inspected object 1 is detected and a phase analysis method is used in the inspection step. The method for producing a deposit according to claim 4, wherein the object 1 to be inspected is heated by using a fiber laser and the infrared rays are detected. The method for producing a deposit according to claim 5, wherein the laser is passed through an apparatus capable of adjusting the irradiation range of the laser, the inspected object 1 is heated, and the infrared rays are detected. The method for producing a deposit according to any one of claims 1 to 3, wherein a tomographic image obtained by imaging the inspected object 1 by X-ray CT or the tomographic image data is used in the inspection step. The method for producing a deposit according to claim 7, wherein X-rays having a wavelength of 0.01 × 10 ^-10 to 100 × 10 ^-10 m are used. Claims 1 to 3 use a fluoroscopic image obtained by imaging an inspected object 1 using an X-ray area sensor or an X-ray inspection apparatus provided with an X-ray line sensor, or data derived from the fluoroscopic image in the inspection step. The method for producing a deposit according to any one of the following items. The method for producing a deposit according to claim 9, wherein the spatial average of the digital values in the fluoroscopic image of the subject 1 is 5% or more and less than 100% of the limit value of the digital values in the fluoroscopic image. The method for producing a deposit according to claim 9 or 10, wherein X-rays having an intensity peak of X-rays having a wavelength of 0.01 × 10 ^-10 to 100 × 10 ^-10 m are used. A step of amplifying numerical digital data based on the relative exposure amount of X-rays received by the X-ray area sensor or the X-ray line sensor, or data calculated based on the data, more than 1.0 times. The method for producing a deposit according to any one of claims 9 to 11, which comprises. The production of the deposit according to any one of claims 1 to 12, wherein the maximum value of the deviation from the average value of the basis weight of the inspection body 1 inspected in the inspection step is 1500 g / m ² or less. Method. The deposit produced by the method for producing a deposit according to any one of claims 1 to 13 is heated to impregnate at least a part of the thermoplastic resin into the aggregate of the discontinuous carbon fibers. How to make a composite material. A claim for producing a composite material by applying a cold press molding method, a hot press molding method, an injection molding method, an injection compression molding method, an extrusion molding method, an insert molding method, or an in-mold coating molding method to the deposit. 14 Method for manufacturing a composite material.