JP7487472B2 - Fiber-reinforced thermoplastic resin moldings and fiber-reinforced thermoplastic resin molding materials - Google Patents

Description

The present invention relates to a fiber-reinforced thermoplastic resin molding product and a fiber-reinforced thermoplastic resin molding material that contain a thermoplastic resin, carbon fiber, and organic fibers having a specific color.

Molded products containing reinforcing fibers and thermoplastic resins are widely used in sporting goods, aerospace, and general industrial applications because they are lightweight and have excellent mechanical properties. Reinforcing fibers used in these molded products include metal fibers such as aluminum fibers and stainless steel fibers, silicon carbide fibers, carbon fibers such as carbon fibers, and organic fibers such as aramid fibers and polyparaphenylenebenzoxazole (PBO) fibers.

Furthermore, molded products containing reinforced fibers and thermoplastic resins have excellent light weight and mechanical properties, and are therefore used in fields such as automobile components and, more recently, electronic device housings and exterior parts for home appliances. In particular, electronic device housings and exterior parts for home appliances require a high level of appearance. More specifically, molded products containing carbon fibers require jet black molded products that reflect the black color of the carbon fibers and have a luxurious and heavy feel.

In addition, motors and other components are built into electronic device housings and exterior parts for home appliances, and with the recent tightening of regulations on noise levels and the trend among users to demand quieter devices, there is an increasing need to make these devices quieter.

As a means of improving mechanical properties, fiber-reinforced thermoplastic resin molded products containing carbon fibers, organic fibers, and a thermoplastic resin, in which the average fiber length and average fiber end distance of the carbon fibers and the average fiber length and average fiber end distance of the organic fibers are within specific ranges (see, for example, Patent Document 1), and fiber-reinforced propylene-based resin compositions containing organic fibers and carbon fibers (see, for example, Patent Document 2) have been proposed.

As a technique for coloring molded products, a propylene-based resin molded product containing colored organic fibers and polypropylene resin has been proposed as a means of suppressing whitening caused by stress concentration in a part of the molded product, or whitening caused by the filler components on the surface of the molded product peeling off or sliding off when rubbed or scratched (see, for example, Patent Document 3).

International Publication No. 2014/098103 JP 2009-114332 A JP 2011-137078 A

Patent Documents 1 and 2 disclose that molded articles obtained using the techniques contain organic fibers in addition to carbon fibers to improve impact strength. Patent Document 3 also discloses that whitening can be suppressed by adding colored fibers to thermoplastic resins.

However, because the molded articles obtained by the techniques of Patent Documents 1 and 2 also use organic fibers, the appearance of the molded article is easily affected by the color tone of the organic fibers. Patent Documents 1 and 2 do not mention the appearance quality of the molded article, but it is presumed that if the organic fibers specifically described in Patent Documents 1 and 2 are used, a black molded article cannot be obtained. Furthermore, because the molded article obtained by the technique of Patent Document 3 does not contain carbon fibers, the improvement in mechanical strength is insufficient, and it is presumed that it is difficult to obtain a black molded article. In addition, there is no mention of noise reduction in any of Patent Documents 1 to 3.

As described above, conventional techniques have not produced fiber-reinforced thermoplastic resin molded products with high mechanical properties (excellent impact resistance), excellent appearance quality (black color), and excellent noise reduction properties in fiber-reinforced thermoplastic resin molded products with a thermoplastic resin matrix, and there has been a demand for the development of such fiber-reinforced thermoplastic resin molded products.

In view of the above problems with the conventional technology, the present invention aims to provide a fiber-reinforced thermoplastic resin molded product that has excellent mechanical properties (impact resistance), appearance quality, and noise reduction properties, and a fiber-reinforced thermoplastic resin molding material from which such a molded product can be obtained.

In order to solve the above problems, the present invention mainly comprises the following configuration.
(1) A fiber-reinforced thermoplastic resin molded product comprising carbon fiber (A), colored organic fiber (B) containing at least one of a colorant other than black, an inorganic pigment, and an organic pigment, a thermoplastic resin (C), and a component (D) selected from an epoxy resin, a phenolic resin, a terpene resin, and a cyclic polyarylene sulfide resin, the component (D) having a melt viscosity at 200°C lower than that of the thermoplastic resin (C), the product comprising 5 to 45 parts by weight of carbon fiber (A), 1 to 45 parts by weight of the colored organic fiber (B), and 10 to 94 parts by weight of the thermoplastic resin (C) per 100 parts by weight of the total of the carbon fiber (A), the colored organic fiber (B), and the thermoplastic resin (C), and the product has an L ^* of 25 to 70 in the CIELab color space of the colored organic fiber (B). , a value of -110 to +110 (excluding -1 to +4), b value of -110 to +110 (excluding -1 to +4) , fiber strength of 4 cN/dtex or more, and energy propagation speed represented by formula (1) of 2.0 km/s or more, the weight average fiber length (L _wa ) of the carbon fiber (A) in the fiber-reinforced thermoplastic resin molded product is 0.3 mm or more and 1.5 mm or less, and the weight average fiber length (L _wb ) of the colored organic fiber (B) is 2 mm or more and 10 mm or less. A fiber-reinforced thermoplastic resin molded product.

(2) A fiber-reinforced thermoplastic resin molding material comprising carbon fiber (A), colored organic fiber (B) containing at least one of a colorant other than black, an inorganic pigment, and an organic pigment, a thermoplastic resin (C), and a component (D) selected from an epoxy resin, a phenolic resin, a terpene resin, and a cyclic polyarylene sulfide resin having a melt viscosity at 200°C lower than that of the thermoplastic resin (C), the material comprising 5 to 45 parts by weight of carbon fiber (A), 1 to 45 parts by weight of the colored organic fiber (B), 10 to 93 parts by weight of the thermoplastic resin (C), and 1 to 20 parts by weight of the component (D), relative to a total of 100 parts by weight of the carbon fiber (A), the colored organic fiber (B), and the thermoplastic resin (C), and the material has an L ^* of 25 to 70 in the CIELab color space of the colored organic fiber (B). , a value of -110 to +110 (excluding -1 to +4), b value of -110 to +110 (excluding -1 to +4) , fiber strength of 4 cN/dtex or more, and energy propagation speed represented by formula (1) of 2.0 km/s or more, carbon fiber (A) and the colored organic fiber (B) are arranged substantially parallel to the axial direction, and the length of the carbon fiber (A) and the colored organic fiber (B) is substantially the same as the length of the fiber reinforced thermoplastic resin molding material, and the length of the fiber reinforced thermoplastic resin molding material in the longitudinal direction is 2 to 10 mm. A fiber reinforced thermoplastic resin molding material.

The fiber-reinforced thermoplastic resin molded product of the present invention contains carbon fiber, organic fiber, and thermoplastic resin, and therefore has a high reinforcing effect and excellent impact properties. Furthermore, since the fiber-reinforced thermoplastic resin molded product of the present invention contains organic fibers having a specific color tone, the molded product also has excellent appearance quality and noise reduction. Such molded products can be obtained by using the fiber-reinforced thermoplastic resin molding material of the present invention.

These molded products are extremely useful for electrical and electronic equipment, office automation equipment, home appliances, housings, and automobile parts, and are particularly suitable for use in electronic equipment housings that incorporate motors and exterior parts for home appliances. Specific examples of molded products include automobile parts such as instrument panels, parts for home and office electrical appliances such as telephones, facsimiles, VTRs, copy machines, televisions, microwave ovens, audio equipment, refrigerators, air conditioners, and vacuum cleaners, and even electrical and electronic equipment components such as housings used in personal computers and mobile phones, and keyboard supports that support keyboards inside personal computers.

FIG. 2 is a schematic diagram showing a form in which carbon fibers (A) enclose organic fibers (B) in a cross section of a molding material. FIG. 2 is a schematic diagram showing a form in which organic fibers (B) enclose carbon fibers (A) in a cross section of a molding material. FIG. 2 is a schematic diagram showing a state in which bundles of carbon fibers (A) and bundles of organic fibers (B) are present in a state separated by a boundary portion in a cross section of a molding material. FIG. 2 is a schematic diagram showing a composite fiber bundle (E) in a form in which a component (D) is attached to a fiber bundle made of carbon fiber (A) and organic fiber (B) in a cross section of a molding material.

The present invention is a fiber-reinforced thermoplastic resin molded product containing carbon fiber (A), organic fiber (B), and thermoplastic resin (C), and the fiber-reinforced thermoplastic resin molded product contains 5 to 45 parts by weight of carbon fiber (A), 1 to 45 parts by weight of organic fiber (B), and 10 to 94 parts by weight of thermoplastic resin (C) relative to a total of 100 parts by weight of carbon fiber (A), organic fiber (B), and thermoplastic resin (C). In the fiber-reinforced thermoplastic resin molded product, the weight average fiber length (L _wa ) of the carbon fiber (A) is 0.3 mm or more and 1.5 mm or less, and the weight average fiber length (L _wb ) of the organic fiber (B) is 2 mm or more and 10 mm or less. Further, a fiber-reinforced thermoplastic resin molding material containing carbon fiber (A), organic fiber (B), thermoplastic resin (C), and a component (D) having a melt viscosity at 200 ° C. lower than that of the thermoplastic resin (C), which can be used to obtain such a molded product, and which contains 5 to 45 parts by weight of carbon fiber (A), 1 to 45 parts by weight of organic fiber (B), 10 to 93 parts by weight of thermoplastic resin (C), and 1 to 20 parts by weight of component (D) relative to a total of 100 parts by weight of carbon fiber (A), organic fiber (B), and thermoplastic resin (C), and the carbon fiber (A) and the organic fiber (B) are arranged almost parallel to the axial direction, and the lengths of the components (A) and (B) are substantially the same as the length of the fiber-reinforced thermoplastic resin molding material, and the fiber-reinforced thermoplastic resin molding material has a longitudinal length of 2 mm to 10 mm. Also included in the present invention is a fiber-reinforced thermoplastic resin molding material. Thus, the fiber-reinforced thermoplastic resin molded product (sometimes referred to as "molded product") and the fiber-reinforced thermoplastic resin molding material (sometimes referred to as "molding material") of the present invention both contain at least carbon fiber (A), organic fiber (B), and thermoplastic resin (C).

The organic fiber (B) containing at least one of a colorant other than black, an inorganic pigment, and an organic pigment in the present invention has, in the CIELab color space, an L ^* of 25 to 70 , an a value of -110 to +110 (excluding -1 to +4), and a b value of -110 to +110 (excluding -1 to +4) , a fiber strength of 4 cN/dtex or more, and an energy propagation velocity of 2.0 km/s or more.

<Molded products>
First, the molded article of the present invention will be described in detail. The molded article of the present invention is a fiber-reinforced thermoplastic resin molded article containing carbon fibers (A), organic fibers (B), and a thermoplastic resin (C).

<Carbon fiber (A)>
The carbon fiber (A) in the present invention can improve the mechanical properties of the molded article due to the fiber reinforcing effect on the thermoplastic resin (C). Furthermore, when the carbon fiber (A) has inherent properties such as electrical conductivity or thermal conductivity, the molded article can be imparted with these properties that cannot be achieved by the thermoplastic resin (C) alone. In addition, for the purpose of imparting electrical conductivity, carbon fibers coated with metals such as nickel, copper, and ytterbium are also preferably used.

There are no particular limitations on the carbon fibers, but examples include PAN-based carbon fibers, pitch-based carbon fibers, rayon-based carbon fibers, cellulose-based carbon fibers, vapor-grown carbon fibers, and graphitized fibers of these.

Furthermore, the carbon fiber preferably has a surface oxygen concentration ratio [O/C], which is the ratio of the number of oxygen (O) and carbon (C) atoms on the fiber surface measured by X-ray photoelectron spectroscopy, of 0.05 to 0.5. A surface oxygen concentration ratio of 0.05 or more ensures a sufficient amount of functional groups on the carbon fiber surface, and stronger adhesion to the thermoplastic resin (C) can be obtained, thereby further improving the bending strength and tensile strength of the molded product. A surface oxygen concentration ratio of 0.1 or more is more preferable. Furthermore, the upper limit of the surface oxygen concentration ratio is more preferably 0.3 or less, in terms of the balance between the handleability and productivity of the carbon fiber.

The surface oxygen concentration ratio of carbon fiber is determined by X-ray photoelectron spectroscopy according to the following procedure. First, if a sizing agent or the like is attached to the carbon fiber surface, the sizing agent or the like is removed with a solvent. The carbon fiber is cut to 20 mm and spread out and arranged on a copper sample support, and then AlKα1 and 2 are used as X-ray sources, and the inside of the sample chamber is kept at 1×10 ⁻⁸ Torr. The kinetic energy value (K.E.) of the main peak of C _1s is adjusted to 1202 eV as a correction value for the peak associated with charging during measurement. The C _1s peak area is determined by drawing a straight baseline in the K.E. range of 1191 to 1205 eV. The O _1s peak area is determined by drawing a straight baseline in the K.E. range of 947 to 959 eV.

Here, the surface oxygen concentration ratio [O/C] is calculated as an atomic ratio using a sensitivity correction value specific to the device from the ratio of the O _1s peak area to the C _1s peak area. As the X-ray photoelectron spectrometer, an ES-200 model manufactured by International Electric Co., Ltd. is used, and the sensitivity correction value is set to 1.74. The average fiber diameter of the carbon fiber is not particularly limited, but is preferably 1 to 20 μm, more preferably 3 to 15 μm, from the viewpoint of the mechanical properties and surface appearance of the molded product.

The carbon fibers may be surface-treated for the purpose of improving the adhesion between the carbon fibers and the thermoplastic resin (C). Examples of surface treatment methods include electrolytic treatment, ozone treatment, and ultraviolet treatment.

The carbon fibers may be provided with a sizing agent for the purpose of preventing fluffing of the carbon fibers and improving the adhesion between the carbon fibers and the thermoplastic resin (C). By providing a sizing agent, the surface properties such as functional groups on the carbon fiber surface can be improved, and the adhesion and mechanical properties (particularly impact strength) of the molded product can be improved. Examples of sizing agents include epoxy resins, phenolic resins, polyethylene glycol, polyurethane, polyester, emulsifiers, and surfactants. Two or more of these may be used. The sizing agent is preferably water-soluble or water-dispersible. Epoxy resins that have excellent wettability with carbon fibers are preferred, and polyfunctional epoxy resins are more preferred.

Examples of polyfunctional epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, aliphatic epoxy resins, and phenol novolac type epoxy resins. Among them, aliphatic epoxy resins, which are easy to exhibit adhesion with the thermoplastic resin (C), are preferred. Because aliphatic epoxy resins have a flexible skeleton, they tend to have a structure with high toughness even when the crosslinking density is high. Furthermore, when aliphatic epoxy resins are present between carbon fiber and thermoplastic resin, they are flexible and difficult to peel off, which can further improve the strength of the molded product.

Examples of polyfunctional aliphatic epoxy resins include diglycidyl ether compounds and polyglycidyl ether compounds. Examples of diglycidyl ether compounds include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ethers, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ethers, 1,4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, polytetramethylene glycol diglycidyl ethers, polyalkylene glycol diglycidyl ethers, and the like. Examples of polyglycidyl ether compounds include glycerol polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ethers, sorbitol polyglycidyl ethers, arabitol polyglycidyl ethers, trimethylolpropane polyglycidyl ethers, trimethylolpropane glycidyl ethers, pentaerythritol polyglycidyl ethers, and polyglycidyl ethers of aliphatic polyhydric alcohols.

Among the above aliphatic epoxy resins, aliphatic epoxy resins having three or more functionalities are preferred, and aliphatic polyglycidyl ether compounds having three or more highly reactive glycidyl groups are more preferred. Aliphatic polyglycidyl ether compounds have a good balance of flexibility, crosslinking density, and compatibility with the thermoplastic resin (C), and can further improve adhesion. Among these, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ethers, polyethylene glycol glycidyl ethers, and polypropylene glycol glycidyl ethers are more preferred.

The amount of sizing agent attached is preferably 0.01 to 10% by weight, based on 100% by weight of the total of the sizing agent and carbon fiber. If the amount of sizing agent attached is 0.01% by weight or more, the adhesion to the thermoplastic resin (C) can be further improved. The amount of sizing agent attached is more preferably 0.05% by weight or more, and even more preferably 0.1% by weight or more. On the other hand, if the amount of sizing agent attached is 10% by weight or less, the physical properties of the thermoplastic resin (C) can be maintained at a higher level. The amount of sizing agent attached is more preferably 5% by weight or less, and even more preferably 2% by weight or less.

<Organic fiber (B)>
The molded article of the present invention contains organic fiber (B) in addition to the carbon fiber (A) described above. Carbon fibers such as carbon fiber (A) are rigid and brittle, so they are difficult to tangle and break easily. Therefore, fiber bundles consisting only of carbon fibers have the problem that they are easily cut during the production of molded articles or easily fall off from the molded articles. On the other hand, organic fiber (B) has flexibility, so it is difficult to break during molding and tends to remain in the molded article while maintaining its long fiber length. Therefore, by including flexible and difficult-to-break organic fiber (B), the impact properties of the molded article can be significantly improved.

Specifically, by setting the remaining fiber length of the organic fibers (B) in the molded article (in other words, the weight average fiber length (L _wb ) in the molded article) to 2 mm or more and 10 mm or less, the molded article can be endowed with higher impact resistance. Furthermore, by setting the weight average fiber length (L _wb ) of the organic fibers (B) within this range, noise reduction can be improved.

Moreover, the organic fiber (B) contained in the molded article of the present invention has, in the CIELab color space, an L ^* of 25 to 70. By setting the color tone of the organic fiber (B) within the above-mentioned range, the molded article can have a desired appearance quality.

The CIELab color space is one of the methods of displaying colors, and was formulated by the International Commission on Illumination (CIE). L ^* a ^* b ^* indicate three-dimensional coordinate axes in a color solid, with L ^* representing lightness, L ^* =0 being the darkest (black), and L ^* =100 being the brightest (white). With respect to a ^* b ^* , tan θ(b ^* /a ^* ) represents the hue, each of which has a + and - range. That is, the L ^* axis stands perpendicular to the origin 0, and a ^* and b ^* are perpendicular to the vertical and horizontal axes at a certain L ^* value, and if a ^* is +, it represents red, if -, it represents the complementary color green, if b ^* is +, it represents yellow, and if -, it represents the complementary color blue. In the present invention, by focusing on the lightness represented by L ^* , it has been found that by setting the L ^* of the organic fiber (B) within a specific range, the appearance quality of a molded product containing the organic fiber can be controlled.

To explain the appearance quality in the present invention more specifically, when a fiber-reinforced thermoplastic resin molded product is applied to the exterior parts of electronic devices and home appliances, the color of the fiber is reflected in the appearance of the molded product. In particular, in the case of a molded product containing carbon fiber, a black-based appearance is often required to give a luxurious feel. When carbon fiber and organic fiber are used in combination to improve mechanical strength, the color derived from the organic fiber may be reflected in the appearance, and the luxurious feel of the obtained molded product may be impaired. However, if organic fiber (B) having L ^* in the above range is used, a molded product with low brightness and black color can be obtained, similar to a molded product containing only carbon fiber, and a molded product with high impact strength can be obtained.

The L ^* of the organic fiber (B) is 25 or more. In order to obtain an organic fiber with L ^* of 25 or more, it is common to prevent the coloring without including a colorant. On the other hand, since the color becomes black when L ^* is closer to 0, it is presumed that if an organic fiber with L ^* close to 0 is used, the molded product obtained will be black even when used in combination with carbon fiber. However, in order to obtain an organic fiber with L ^* of less than 25, in other words, L ^* close to 0, it is common to knead a black colorant such as carbon black into the thermoplastic resin to be spun and then perform spinning. At this time, if the content of the black colorant is high, the mechanical properties (e.g., tensile strength and tensile elongation) of the organic fiber (B) tend to decrease. Therefore, when the organic fiber (B) kneaded with the colorant is contained in the molded product, the mechanical strength (especially the impact strength) of the molded product obtained decreases. Therefore, in order to achieve both the appearance quality and impact strength of the molded product, it is necessary to set the L ^* of the organic fiber (B) to the above-mentioned range. L ^* is more preferably 30 or more, and more preferably 40 or more. Furthermore, the L ^* of the organic fiber (B) is 70 or less. If it is 70 or less, whitening of the molded product can be suppressed. To make L ^* 70 or less, a colorant other than black, an inorganic pigment or an organic pigment can be used, and among inorganic pigments, a colored inorganic pigment is preferable.

As described above, when making a molded article black, this is possible by setting the L ^* of the organic fiber (B) within a preferred range, and the a value of the organic fiber is preferably −110 to +110 (excluding −1 to +4), and the b value is preferably −110 to +110 (excluding −1 to +4). By setting the a value and b value of the organic fiber within the preferred ranges, it is possible to add color to the organic fiber, and it is possible to adjust the appearance to a desired one.

The measurement method for the Lab color space is specified in the Japanese Industrial Standard JIS Z 8781-4:2013, and can be measured using a spectrophotometer, which is a measuring device that complies with this measurement method.

The organic fiber (B) can be appropriately selected within a range that does not significantly reduce the mechanical properties of the molded product. For example, the fibers can be obtained by spinning resins such as polyolefin resins such as polyethylene and polypropylene, polyamide resins such as nylon 6, nylon 66, and aromatic polyamide, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, fluororesins such as polytetrafluoroethylene, perfluoroethylene-propene copolymer, and ethylene-tetrafluoroethylene copolymer, liquid crystal polymers such as liquid crystal polyester and liquid crystal polyesteramide, and polyarylene sulfides such as polyether ketone, polyether sulfone, and polyphenylene sulfide. Two or more of these may be used. It is preferable to appropriately select and use from among these organic fibers (B) in combination with the thermoplastic resin (C). In particular, the melting temperature of the organic fiber (B) is preferably 30°C to 150°C higher than the molding temperature (melting temperature) of the thermoplastic resin (C), and more preferably 50°C to 100°C higher. Alternatively, organic fibers (B) made of a resin that is incompatible with the thermoplastic resin (C) are preferred because they remain in a fibrous state within the molded article, and therefore can further improve the impact properties of the molded article. They also have excellent noise reduction properties. Examples of organic fibers (B) with high melting temperatures include polyester fibers and liquid crystal polyester fibers. As the organic fibers (B) in the present invention, it is preferred to use at least one type of fiber selected from the group consisting of these.

It has become clear that, among the organic fibers (B) exemplified above, when polyester fibers or liquid crystal polyester fibers are used, the transmission loss increases, and the molded product is particularly quiet.

To explain more specifically about the quietness of the present invention, when a fiber-reinforced thermoplastic resin molded product is applied to the housing of an electronic device and the exterior parts for home appliances, the increased rigidity of the molded product makes it easier for internal sounds to resonate, i.e., the sound is more likely to leak to the outside. Since the leakage of operating sounds leads to discomfort for users, there is a demand for an improvement in the transmission loss (an index showing how quiet the sound is when heard from the sound source through a partition wall) through the exterior parts of the molded product. This demand is particularly high for housings of electronic devices and exterior parts for home appliances that have motors built in.

In the present invention, it has become clear that when a specific polyester fiber and/or liquid crystal polyester fiber is used among the organic fibers (B) exemplified above, the transmission loss increases, and the molded product is particularly excellent in terms of noise reduction. Although the reason for this is unclear, it is presumed to be due to the high energy propagation velocity of the organic fiber (B). Here, the energy propagation velocity can be calculated from the initial elastic modulus and fiber density of the fiber using the following formula.

A high energy propagation speed indicates that the energy given to the fiber is easily propagated over a wider range. In other words, by including organic fiber (B) with excellent energy propagation speed, the energy given to the molded product can be diffused throughout the entire molded product more quickly. The diffused energy gradually decreases, and as a result, the energy can be shielded within the molded product, resulting in high transmission loss. It is believed that the same action occurs with the sound that is the subject of this application, and therefore the transmission loss is high and high quietness is expressed by using fibers with a high energy propagation speed. It is presumed that the above-mentioned polyester fiber and liquid crystal polyester fiber are able to express excellent quietness characteristics because of their excellent energy propagation speed obtained from the above-mentioned formula. Furthermore, if the above-mentioned organic fiber (B) remains in the molded product for a long time, the energy propagates within the fiber, so that the energy can be diffused more efficiently and the transmission loss can be increased, and therefore the quietness effect is further enhanced. By improving the quietness, the quietness can be improved when used as an exterior part. The energy propagation speed of the organic fiber (B) in this invention is 2.0 km/s or more. 2.5 or more is more preferable. The energy propagation speed is preferably 25 km/s or less, and more preferably 20 km/s. If the energy propagation speed exceeds 25 km/s, the propagation speed of cracks inside the molded product will increase, and the mechanical strength of the molded product, especially its impact strength, will decrease, which is undesirable.

Examples of organic fibers with an energy propagation speed of 2.0 km/s or more include "Tetoron (registered trademark)" 1670T-144-706C, "Sciberas" (registered trademark) 1700T-288f, "Tetoron (registered trademark)" 1670T-144-706C, and "Tetoron (registered trademark)" 1670T-108-705C (all manufactured by Toray Industries, Inc.).

Transmission loss can be measured using normal incidence transmission loss measurement in a transmission type acoustic chamber. Specifically, a round molded product that has been processed to a specified size is placed in the acoustic chamber, and a microphone is installed on one side of the molded product, and a speaker is installed on the other side of the molded product. A certain amount of sound pressure is then generated from the speaker, and the amount of sound pressure that reaches the microphone after passing through the molded product is measured. There are no particular limitations on the sound measurement frequency band, and measurements are performed in the general frequency band of 500 Hz to 7000 Hz.

The single fiber fineness of the organic fiber (B) is preferably 0.1 to 50 dtex. It is preferably 3 dtex or more, and more preferably 6 dtex or more. By setting the single fiber fineness within the above-mentioned range, it is possible to increase the impact strength of the molded product because the fiber length tends to remain long in the molded product due to the resistance to fiber shear during molding.

The fiber strength of the organic fiber (B) can be determined by a known single-fiber tensile test. Here, the fiber strength of the organic fiber (B) can be calculated by performing a tensile test in a room under standard conditions (20°C, 65% RH) with a grip interval of 250 mm and a tensile speed of 300 mm/min, and dividing the load at the time of fiber breakage by the single-fiber fineness. Here, the single-fiber fineness represents the thickness of a thread that has a length of 10,000 m and weighs 1 g, and the single-fiber fineness of the organic fiber (B) used in the present invention can be determined by a known fiber fineness measurement (for example, JIS L 1013:2010).

The fiber strength is 4 cN/dtex or more. If it is less than 4 cN/dtex, the impact properties of the molded product in particular will be reduced. It is preferable that it exceeds 4 cN/dtex, more preferably 5 cN/dtex or more, and even more preferably 6 cN/dtex or more. In addition, the initial fiber elastic modulus was calculated from the initial slope in the stress-strain curve obtained with the above-mentioned fiber strength.

The fiber strength is preferably 50 cN/dtex, more preferably 40 cN/dtex, and even more preferably 30 cN/dtex. If the fiber strength exceeds 50 cN/dtex, it is not preferable because cutting of the fiber becomes difficult and the productivity of the molding material decreases.

The density of the organic fiber (B) can be determined by known density measurements (e.g., JIS L 1015:2010).

<Thermoplastic resin (C)>
In the present invention, the thermoplastic resin (C) is a matrix resin constituting the molded article and the molding material. The thermoplastic resin (C) is preferably one having a molding temperature (melting temperature) of 200 to 450°C, and examples thereof include polyolefin resin, polystyrene resin, polyamide resin, halogenated vinyl resin, polyacetal resin, saturated polyester resin, polycarbonate resin, polyarylsulfone resin, polyarylketone resin, polyarylene ether resin, polyarylene sulfide resin, polyaryletherketone resin, polyethersulfone resin, polyarylenesulfide sulfone resin, polyarylate resin, and polyamide resin. Two or more of these may be used. As the polyolefin resin, polypropylene resin is preferable.

Among the thermoplastic resins (C), at least one selected from the group consisting of polypropylene resin, polyamide resin, polycarbonate resin, and polyarylene sulfide resin is more preferable because it is lightweight and has an excellent balance between mechanical properties and moldability, and polypropylene resin and polycarbonate resin are even more preferable because they are highly versatile. The polypropylene resin may be unmodified or modified.

Specific examples of unmodified polypropylene resins include homopolymers of propylene and copolymers of propylene and at least one monomer selected from the group consisting of α-olefins, conjugated dienes, non-conjugated dienes, and other thermoplastic monomers. Propylene homopolymers are preferred from the viewpoint of improving the rigidity of molded articles. Random or block copolymers of propylene and at least one monomer selected from the group consisting of α-olefins, conjugated dienes, and non-conjugated dienes are preferred from the viewpoint of further improving the impact properties of molded articles.

As the modified polypropylene resin, an acid-modified polypropylene resin is preferable, and an acid-modified polypropylene resin having a carboxylic acid and/or a carboxylate group bonded to the polymer chain is more preferable. The acid-modified polypropylene resin can be obtained by various methods. For example, it can be obtained by graft polymerization of a monomer having a neutralized or non-neutralized carboxylic acid group and/or a monomer having a saponified or non-saponified carboxylate ester group onto an unmodified polypropylene resin.

Here, examples of monomers having a neutralized or unneutralized carboxylic acid group, or monomers having a saponified or unsaponified carboxylic acid ester group include ethylenically unsaturated carboxylic acids, their anhydrides, and ethylenically unsaturated carboxylic acid esters.

Two or more of these can be used. Among these, ethylenically unsaturated carboxylic acid anhydrides are preferred, and maleic anhydride is more preferred.

To further improve the bending strength and tensile strength of the molded product, it is preferable to use both unmodified and modified polypropylene resins. In particular, from the viewpoint of the balance between flame retardancy and bending strength and tensile strength, it is preferable to use unmodified and modified polypropylene resins in a weight ratio of 95/5 to 75/25. More preferably, it is 95/5 to 80/20, and even more preferably, 90/10 to 80/20.

Polyamide resins are resins whose main raw materials are amino acids, lactams, or diamines and dicarboxylic acids.

Polyamide resins with a melting point of 200°C or higher are particularly useful because of their excellent heat resistance and strength. Specific examples thereof include polycaproamide (nylon 6), polyhexamethylene adipamide (nylon 66), polycaproamide/polyhexamethylene adipamide copolymer (nylon 6/66), polytetramethylene adipamide (nylon 46), polyhexamethylene sebacamide (nylon 610), polyhexamethylene dodecamide (nylon 612), polyhexamethylene terephthalamide/polycaproamide copolymer (nylon 6T/6), polyhexamethylene adipamide/polyhexamethylene terephthalamide copolymer (nylon 66/6T), polylaurylamide/polyhexamethylene terephthalamide copolymer (nylon 12T/6), polyhexamethylene adipamide/polyhexamethylene isophthalamide copolymer (nylon 66/6I), polyhexamethylene Examples of such copolymers include nylon 66/6T/6I, nylon 6T/6I/6I, nylon 6T/6I/6I, nylon 6T/6I/6I, nylon 6T/6I, nylon 6T/6I, nylon 6T/12, nylon 6T/12, poly(2-methylpentamethylene) terephthalamide/poly(nylon 6T/M5T), polyxylylene adipamide (nylon XD6), polynonamethylene terephthalamide (nylon 9T), and copolymers thereof. Two or more of these may be used. Of these, nylon 6 and nylon 66 are more preferable.

Polycarbonate resins are obtained by reacting dihydric phenols with carbonate precursors. They may be copolymers obtained using two or more dihydric phenols or two or more carbonate precursors. Examples of reaction methods include interfacial polymerization, melt transesterification, solid-phase transesterification of carbonate prepolymers, and ring-opening polymerization of cyclic carbonate compounds. Such polycarbonate resins are known per se, and the polycarbonate resins described in JP-A-2002-129027 can be used, for example.

As polycarbonate resins, those available on the market such as "Iupilon" (registered trademark) and "Novarex" (registered trademark) manufactured by Mitsubishi Engineering Plastics Corporation, "Panlite" (registered trademark) manufactured by Teijin Chemical Co., Ltd., and "Toughlon" (registered trademark) manufactured by Idemitsu Petrochemical Co., Ltd. can also be used.

Examples of polyarylene sulfide resins include polyphenylene sulfide (PPS) resins, polyphenylene sulfide sulfone resins, polyphenylene sulfide ketone resins, and random or block copolymers thereof. Two or more of these may be used. Of these, polyphenylene sulfide resins are particularly preferred.

Polyarylene sulfide resins can be produced by any method, such as the method for obtaining a polymer with a relatively small molecular weight described in JP-B-45-3368, or the method for obtaining a polymer with a relatively large molecular weight described in JP-B-52-12240 and JP-A-61-7332.

As polyarylene sulfide resins, those commercially available as "TORELINA" (registered trademark) manufactured by Toray Industries, Inc., "DIC.PPS" (registered trademark) manufactured by DIC Corporation, and "DURAFIDE" (registered trademark) manufactured by Polyplastics Co., Ltd. can also be used.

<Content of each ingredient>
The molded article of the present invention contains 5 to 45 parts by weight of carbon fiber (A) per 100 parts by weight of the total of carbon fiber (A), organic fiber (B), and thermoplastic resin (C). If the content of carbon fiber (A) is less than 5 parts by weight, the impact properties of the molded article are reduced. The content of carbon fiber (A) is preferably 7 parts by weight or more, more preferably 10 parts by weight or more. On the other hand, if the content of carbon fiber (A) exceeds 45 parts by weight, the dispersibility of the fibers is reduced, and the entanglement of the fibers increases. As a result, fiber breakage occurs, the fiber length is shortened, and the impact properties are reduced. The content of carbon fiber (A) is preferably 30 parts by weight or less, more preferably 20 parts by weight or less, and even more preferably 15 parts by weight or less.

The content of organic fiber (B) in the molded article of the present invention is 1 to 45 parts by weight per 100 parts by weight of the total of carbon fiber (A), organic fiber (B), and thermoplastic resin (C). If the content of organic fiber (B) is less than 1 part by weight, the impact properties of the molded article are reduced, and the transmission loss of the molded article is also poor. The content of organic fiber (B) is preferably 3 parts by weight or more. On the other hand, if the content of organic fiber (B) exceeds 45 parts by weight, the entanglement of the fibers increases, the dispersibility of organic fiber (B) in the molded article is reduced, and this often leads to a reduction in the impact properties of the molded article. The content of organic fiber (B) is preferably 20 parts by weight or less, more preferably 10 parts by weight or less.

The content of thermoplastic resin (C) in the molded product of the present invention is 10 to 94 parts by weight per 100 parts by weight of the total of carbon fiber (A), organic fiber (B), and thermoplastic resin (C). If the content of thermoplastic resin (C) is less than 10 parts by weight, the fiber dispersion of carbon fiber (A) and organic fiber (B) in the molded product decreases, and the impact properties decrease. The content of thermoplastic resin (C) is preferably 30 parts by weight or more. On the other hand, if the content of thermoplastic resin (C) exceeds 94 parts by weight, the content of carbon fiber (A) and organic fiber (B) becomes relatively small, so the reinforcing effect of the fibers decreases and the impact properties decrease. The content of thermoplastic resin (C) is preferably 85 parts by weight or less, and more preferably 75 parts by weight or less.

<Color tone of molded product>
Next, in the present invention, the color tone of the molded article is preferably L ^* 20 or less. By making L* 20 or less, the surface of the molded article is suppressed from whitening, so that the appearance quality is good and the appearance can be made to have a high-class appearance. It is more preferable that it is 19 or less. As a means for obtaining such a molded article, a method using a molding material described later can be mentioned. In addition, in order to express the desired appearance quality, there is also a method of adding a colorant without using the molding material described later. However, when such a method is used, while the appearance quality is improved, the toughness of the matrix resin is reduced, and the mechanical strength is reduced, so that it is impossible to achieve both appearance quality and mechanical strength.

The L ^* of the molded article can be measured using a spectrophotometer (SD7000 manufactured by Nippon Denshoku Kogyo Co., Ltd.) for a test piece of 80 mm x 80 mm x 3 mm thickness obtained by injection molding, and the L ^* of the appearance of the molded article surface can be measured.

<Other ingredients>
The molded article of the present invention may contain other components in addition to the above (A) to (C) within the scope of the present invention. Examples of the other components include thermosetting resins, flame retardants, crystal nucleating agents, ultraviolet absorbers, antioxidants, vibration dampers, antibacterial agents, insect repellents, deodorants, coloring inhibitors, heat stabilizers, release agents, antistatic agents, plasticizers, lubricants, foaming agents, foam control agents, and coupling agents. In addition, the molded article of the present invention may contain, for example, component (D) used in the molding material described below.

As a coloring inhibitor, general carbon black may be added to suppress whitening. The content of carbon black (J) contained inside the molded product is 0.1 to 10 parts by weight per 100 parts by weight of the total of carbon fiber (A), organic fiber (B), and thermoplastic resin (C). If the content of carbon black (J) is less than 0.1 part by weight, the color tone of the molded product is poor. The content of carbon black (J) is preferably 0.5 parts by weight or more. On the other hand, if the content of carbon black (J) exceeds 10 parts by weight, the molded product becomes brittle and the mechanical strength, especially impact strength, of the molded product decreases, which is not preferable. The content of carbon black (J) is preferably 5 parts by weight or less.

In addition, a general rubber polymer may be used as the vibration damping agent (K).

Rubbery polymers are polymers that contain polymers with low glass transition temperatures, and in which some of the intermolecular bonds are constrained by covalent bonds, ionic bonds, van der Waals forces, entanglements, etc. The glass transition temperature of the rubbery polymer is preferably 25°C or lower. Examples of rubbery polymers include diene rubbers such as polybutadiene, polyisoprene, random copolymers and block copolymers of styrene-butadiene, hydrogenated products of the block copolymers, acrylonitrile-butadiene copolymers, and butadiene-isoprene copolymers; random copolymers and block copolymers of ethylene-propylene; random copolymers and block copolymers of ethylene-butene; copolymers of ethylene and α-olefins; ethylene-unsaturated carboxylic acid copolymers such as ethylene-acrylic acid copolymers and ethylene-methacrylic acid copolymers; ethylene-unsaturated carboxylic acid ester copolymers such as ethylene-acrylic acid esters and ethylene-methacrylic acid esters; copolymers in which some of the unsaturated carboxylic acids are metals. Preferred examples of the salts include ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid metal salt copolymers such as ethylene-acrylic acid-metal acrylic acid salts and ethylene-methacrylic acid-metal methacrylic acid salts; acrylic acid ester-butadiene copolymers, e.g., butyl acrylate-butadiene copolymers, and other acrylic elastic polymers; copolymers of ethylene and vinyl fatty acids, such as ethylene-vinyl acetate; ethylene-propylene-ethylidenenorbornene copolymers, ethylene-propylene-hexadiene copolymers, and other ethylene-propylene non-conjugated diene terpolymers; butylene-isoprene copolymers; chlorinated polyethylene; and thermoplastic elastomers, such as polyamide elastomers and polyester elastomers.

When polyamide or polypropylene is used as the thermoplastic resin (C), from the viewpoint of compatibility, an ethylene-unsaturated carboxylic acid ester copolymer or an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid metal salt copolymer is preferably used.

As the unsaturated carboxylate in the ethylene-unsaturated carboxylate copolymer, a (meth)acrylic acid ester is preferred. Specific examples of unsaturated carboxylate include (meth)acrylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and stearyl (meth)acrylate. Here, "(meth)acrylic acid" means "acrylic acid or methacrylic acid."

The weight ratio of the ethylene component to the unsaturated carboxylic acid ester component in the copolymer is not particularly limited, but is preferably in the range of 90/10 to 10/90, and more preferably 85/15 to 15/85.

The number average molecular weight of the ethylene-unsaturated carboxylic acid ester copolymer is not particularly limited, but from the viewpoint of fluidity and mechanical properties, a range of 1,000 to 70,000 is preferable.

Specific examples of the unsaturated carboxylic acid in the ethylene-unsaturated carboxylic acid-metal salt of unsaturated carboxylic acid copolymer include (meth)acrylic acid. Examples of the metal salt of unsaturated carboxylic acid include metal salt of (meth)acrylic acid. The metal of the metal salt of unsaturated carboxylic acid is not particularly limited, but preferably includes alkali metals such as sodium, alkaline earth metals such as magnesium, zinc, etc.

The weight ratio of the unsaturated carboxylic acid component and the unsaturated carboxylic acid metal salt component in the ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid metal salt copolymer is not particularly limited, but is preferably in the range of 95/5 to 5/95, and more preferably 90/10 to 10/90.

The number average molecular weight of the ethylene-unsaturated carboxylic acid-metal salt of unsaturated carboxylic acid copolymer is not particularly limited, but from the viewpoint of fluidity and mechanical properties, a range of 1,000 to 70,000 is preferable.

The reactive functional group contained in the vibration damping agent is not particularly limited as long as it reacts with the functional group present in the thermoplastic resin (C), but preferably includes at least one selected from the group consisting of amino groups, carboxyl groups, metal salts of carboxyl groups, hydroxyl groups, epoxy groups, acid anhydride groups, isocyanate groups, mercapto groups, oxazoline groups, and sulfonic acid groups. Among these, groups selected from the group consisting of amino groups, carboxyl groups, metal salts of carboxyl groups, epoxy groups, acid anhydride groups, and oxazoline groups are more preferably used because they are highly reactive and cause fewer side reactions such as decomposition and crosslinking.

When introducing an acid anhydride group into a rubbery polymer, the method can be carried out by known techniques and is not particularly limited. For example, a method of copolymerizing an acid anhydride such as maleic anhydride, itaconic anhydride, endic anhydride, citraconic anhydride, or 1-butene-3,4-dicarboxylic anhydride with a monomer that is the raw material of the rubbery polymer, or a method of grafting an acid anhydride onto a rubbery polymer can be used.

In addition, when an epoxy group is introduced into a rubber polymer, the method can be performed by a known technique and is not particularly limited. For example, a method of copolymerizing a vinyl monomer having an epoxy group, such as a glycidyl ester compound of an α,β-unsaturated acid such as glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, or glycidyl itaconate, with a monomer that is a raw material for the rubber polymer, a method of polymerizing a rubber polymer using a polymerization initiator or chain transfer agent having an epoxy group, or a method of grafting an epoxy compound to a rubber polymer can be used. The content of the vibration damping agent (K) is 5 to 30 parts by weight relative to a total of 100 parts by weight of the carbon fiber (A), the organic fiber (B), and the thermoplastic resin (C). If the content of the vibration damping agent (K) is less than 5 parts by weight, the transmission loss of the molded product is inferior. The content of the vibration damping agent (K) is preferably 10 parts by weight or more, more preferably 15 parts by weight or more. On the other hand, if the content of the vibration damping agent (K) exceeds 30 parts by weight, the color tone of the molded article becomes whitish and the L ^* of the molded article decreases, which is not preferable. The content of the vibration damping agent (K) is preferably 25 parts by weight or less.

<Weight average fiber length>
In the molded article of the present invention, the weight average fiber length (L _wa ) of the carbon fiber (A) in the molded article is 0.3 mm or more and 1.5 mm or less. When the average fiber length (L _wa ) of the carbon fiber (A) is less than 0.3 mm, the effect of improving the bending strength and impact properties of the molded article is difficult to achieve. L _wa is preferably 0.4 mm or more, more preferably 0.5 mm or more, and most preferably 0.7 mm or more. On the other hand, when the weight average fiber length (L _wa ) exceeds 1.5 mm, the entanglement between the single yarns of the carbon fiber (A) is difficult to suppress, and the dispersibility is difficult to improve, so that the effect of improving the bending strength of the molded article is difficult to achieve. L _wa is preferably 1.3 mm or less, and more preferably 1 mm or less.

In addition, the molded article of the present invention has a weight average fiber length (L _wb ) of the organic fiber (B) in the molded article of 2 mm or more and 10 mm or less. When the weight average fiber length (L _wb ) of the organic fiber (B) is less than 2 mm, the reinforcing effect of the organic fiber (B) in the molded article is difficult to achieve, the impact properties are poor, the transmission loss is low, and the quietness is poor. L _wb is preferably 3 mm or more. On the other hand, when the average fiber length (L _wb ) exceeds 10 mm, the entanglement between the single yarns of the organic fiber (B) is difficult to suppress and the dispersibility is difficult to improve, so that the impact properties of the molded article are poor. L _wb is more preferably 8 mm or less, and even more preferably 7 mm or less. By setting the weight average fiber length (L _wb ) of the organic fiber (B) in the above-mentioned range, the entanglement between the single yarns of the organic fiber is suppressed, and the organic fiber (B) exists in a state in which the fibers are dispersed while being curved. As a result, the cracks do not propagate in one direction when the molded article is broken, and the molded article can absorb more impact energy, improving its impact strength. The same is true for the transmission loss. By setting the Lwb of the organic fiber (B) within the above range, the range in which sound waves passing through the molded article are blocked is broadened, improving the noise reduction of the molded article.

Here, the "weight average fiber length" in the present invention refers to an average fiber length calculated from the following formula, which does not simply take a number average but applies the calculation method for the weight average molecular weight to the calculation of the fiber length and takes into account the contribution of the fiber length, provided that the following formula is applicable when the fiber diameter and density of the carbon fiber (A) and the organic fiber (B) are constant.
Weight average fiber length=Σ( ^Mi2 ×Ni)/Σ(Mi×Ni)
Mi: fiber length (mm)
Ni: number of reinforcing fibers of fiber length Mi.

The weight average fiber length can be measured by the following method. The ISO dumbbell test piece is sandwiched between glass plates and heated on a hot stage set at 200 to 300°C, and uniformly dispersed in a film. The film in which the fibers are uniformly dispersed is observed under an optical microscope (50 to 200 times). The fiber lengths of 1,000 randomly selected carbon fibers (A) and organic fibers (B) are measured, and the weight average fiber length (L _wa ) of the carbon fibers (A) and the weight average fiber length (L _wb ) of the organic fibers (B) are calculated from the above formula.

The weight average fiber length of the carbon fiber (A) and the organic fiber (B) in the molded product can be adjusted, for example, by the molding conditions. In the case of injection molding, for example, such molding conditions include pressure conditions such as back pressure and dwell pressure, time conditions such as injection time and dwell time, and temperature conditions such as cylinder temperature and mold temperature. Specifically, by taking advantage of the fact that the organic fiber (B) is more flexible and less likely to break than the carbon fiber (A), the pressure conditions such as back pressure are increased appropriately to appropriately increase the shear force in the cylinder, and the average fiber length of the carbon fiber (A) is made shorter than that of the organic fiber (B). In addition, the injection time may be appropriately shortened to appropriately increase the shear force during injection, and the average fiber length of the carbon fiber (A) may be made shorter than that of the organic fiber (B). Furthermore, by appropriately lowering the temperature such as the cylinder temperature and mold temperature, the viscosity of the flowing resin increases, and the shear force can be increased, so that the average fiber length of the carbon fiber (A) can be made shorter than that of the organic fiber (B) by such a method. In the present invention, the average fiber length of the carbon fiber (A) and the organic fiber (B) in the molded product can be adjusted to the desired range by appropriately changing the conditions as described above. Among these, it is particularly effective to adjust the shear force by controlling the back pressure conditions and injection time. However, care must be taken because if the shear force acting on the fibers is increased more than necessary, the average fiber length of not only the carbon fiber (A) but also the organic fiber (B) will be shortened.

In the present invention, the weight average fiber length (L _wa ) of the carbon fiber (A) and the weight average fiber length (L _wb ) of the organic fiber (B) can be set within the above ranges by using a molding material described later.

<Molding material>
Next, the form of the molding material of the present invention will be described. In the present invention, the "molding material" means a raw material used when molding a molded article by injection molding or the like.

In the present invention, a fiber-reinforced thermoplastic resin molding material containing carbon fiber (A), organic fiber (B), thermoplastic resin (C), and component (D) having a melt viscosity at 200 ° C. lower than that of thermoplastic resin (C), and containing 5 to 45 parts by weight of carbon fiber (A), 1 to 45 parts by weight of organic fiber (B), 10 to 93 parts by weight of thermoplastic resin (C), and 1 to 20 parts by weight of component (D) per 100 parts by weight of carbon fiber (A), organic fiber (B), thermoplastic resin (C), and component (D) in total, can be suitably used as a molding material for obtaining the molded product of the present invention. The specific shape of such a molding material will be described later, but examples include a columnar body having a cross section as shown in Figures 1 to 4. Figures 1 to 3 show an embodiment in which a thermoplastic resin (C) containing component D is arranged around a fiber bundle made of carbon fiber (A) and organic fiber (B) (an embodiment in which there is no clear boundary between component D and thermoplastic resin (C)), and Figure 4 shows an embodiment in which component (D) is arranged around a fiber bundle made of carbon fiber (A) and organic fiber (B), and thermoplastic resin (C) is further arranged around the outer periphery of that.

The molding material of the present invention contains 5 to 45 parts by weight of carbon fiber (A) per 100 parts by weight of the total of carbon fiber (A), organic fiber (B), thermoplastic resin (C) and component (D). If the content of carbon fiber (A) is less than 5 parts by weight, the impact properties of the molded product will be reduced. The content of carbon fiber (A) is preferably 7 parts by weight or more, more preferably 10 parts by weight or more. On the other hand, if the content of carbon fiber (A) exceeds 45 parts by weight, the dispersion of the fibers will decrease, and the entanglement of the fibers will increase. As a result, fiber breakage will occur, the fiber length will be shortened, and the impact properties will be reduced. The content of carbon fiber (A) is preferably 30 parts by weight or less, more preferably 20 parts by weight or less, and even more preferably 15 parts by weight or less.

The content of organic fiber (B) in the molded article of the present invention is 1 to 45 parts by weight per 100 parts by weight of the total of carbon fiber (A), organic fiber (B), thermoplastic resin (C) and component (D). If the content of organic fiber (B) is less than 1 part by weight, the impact properties of the molded article are reduced, and the transmission loss of the molded article is also poor. The content of organic fiber (B) is preferably 3 parts by weight or more. On the other hand, if the content of organic fiber (B) exceeds 45 parts by weight, the entanglement of the fibers increases, the dispersibility of organic fiber (B) in the molded article is reduced, and this often leads to a reduction in the impact properties of the molded article. The content of organic fiber (B) is preferably 20 parts by weight or less, more preferably 10 parts by weight or less.

The content of thermoplastic resin (C) in the molded product of the present invention is 10 to 93 parts by weight per 100 parts by weight of the total of carbon fiber (A), organic fiber (B), thermoplastic resin (C) and component (D). If the content of thermoplastic resin (C) is less than 10 parts by weight, the fiber dispersion of carbon fiber (A) and organic fiber (B) in the molded product decreases, and the impact properties decrease. The content of thermoplastic resin (C) is preferably 30 parts by weight or more. On the other hand, if the content of thermoplastic resin (C) exceeds 93 parts by weight, the content of carbon fiber (A) and organic fiber (B) becomes relatively small, so the reinforcing effect of the fibers decreases and the impact properties decrease. The content of thermoplastic resin (C) is preferably 84 parts by weight or less, and more preferably 74 parts by weight or less.

The carbon fibers (A), organic fibers (B), and thermoplastic resin (C) in the molding material may be (A) to (C) as described above for the molded product of the present invention, and may also contain other components as exemplified for the molded product of the present invention. The effects of these are also as described above. However, the carbon fibers (A) and organic fibers (B) may each be bundled in the molding material before molding, and as described below, they preferably have substantially the same length as the molding material containing the fibers.

Component (D), which has a lower melt viscosity at 200°C than thermoplastic resin (C), often has a low molecular weight and is usually a relatively brittle and easily crushed solid or liquid at room temperature. Since component (D) has a low molecular weight, it has high fluidity and can enhance the dispersion effect of carbon fiber (A) and organic fiber (B) in thermoplastic resin (C). Examples of component (D) include epoxy resin, phenol resin, terpene resin, and cyclic polyarylene sulfide resin. Two or more of these may be contained. Component (D) is preferably one that has a high affinity with thermoplastic resin (C). By selecting component (D) that has a high affinity with thermoplastic resin (C), it is efficiently compatible with thermoplastic resin (C) during the production of the molding material and during molding, and therefore the dispersibility of carbon fiber (A) and organic fiber (B) can be further improved.

Component (D) is appropriately selected depending on the combination with thermoplastic resin (C). For example, if the molding temperature is in the range of 150°C to 270°C, terpene resin is preferably used. If the molding temperature is in the range of 270°C to 320°C, epoxy resin, phenol resin, and cyclic polyarylene sulfide resin are preferably used. Specifically, if the thermoplastic resin (C) is a polypropylene resin, component (D) is preferably a terpene resin. If the thermoplastic resin (C) is a polycarbonate resin or a polyarylene sulfide resin, component (D) is preferably an epoxy resin, a phenol resin, or a cyclic polyarylene sulfide resin. If the thermoplastic resin (C) is a polyamide resin, component (D) is preferably a terpene phenol resin.

The melt viscosity of component (D) at 200°C is preferably 0.01 to 10 Pa·s. If the melt viscosity at 200°C is 0.01 Pa·s or more, the destruction originating from component (D) can be further suppressed, and the impact properties of the molded product can be further improved. The melt viscosity is more preferably 0.05 Pa·s or more, and even more preferably 0.1 Pa·s or more. On the other hand, if the melt viscosity at 200°C is 10 Pa·s or less, component (D) can be easily impregnated into the inside of carbon fiber (A) and organic fiber (B). Therefore, when molding the molding material of the present invention, the dispersibility of carbon fiber (A) and organic fiber (B) can be further improved. The melt viscosity is preferably 5 Pa·s or less, and more preferably 2 Pa·s or less. Here, the melt viscosity at 200°C of thermoplastic resin (C) and component (D) can be measured by a viscoelasticity measuring instrument at 0.5 Hz using a 40 mm parallel plate.

As described below, in producing the molding material of the present invention, it is preferable to first obtain a composite fiber bundle (E) by attaching component (D) to carbon fiber (A) and organic fiber (B), and the melting temperature (temperature in the melt bath) when supplying component (D) is preferably 100 to 300°C. Therefore, we focused on the melt viscosity of component (D) at 200°C as an index of the impregnation of carbon fiber (A) and organic fiber (B) with component (D). If the melt viscosity at 200°C is in the above-mentioned preferred range, the impregnation of carbon fiber (A) and organic fiber (B) is excellent in such a preferred melting temperature range, and the dispersibility of carbon fiber (A) and organic fiber (B) in the molded product can be further improved, and the mechanical properties, especially the impact properties, of the molded product can be further improved.

The number average molecular weight of component (D) is preferably 200 to 50,000. If the number average molecular weight is 200 or more, the mechanical properties, especially the impact properties, of the molded article can be further improved. The number average molecular weight is more preferably 1,000 or more. Furthermore, if the number average molecular weight is 50,000 or less, the viscosity of component (D) is appropriately low, so that the impregnation of the carbon fiber (A) and organic fiber (B) contained in the molded article is excellent, and the dispersibility of the carbon fiber (A) and organic fiber (B) in the molded article can be further improved. The number average molecular weight is more preferably 3,000 or less. The number average molecular weight of such a compound can be measured using gel permeation chromatography (GPC).

It is preferable that component (D) has a heat loss of 5% or less by weight when heated at a rate of 10°C/min (in air) at the molding temperature. More preferably, it is 3% or less by weight. When the heat loss is 5% or less by weight, the generation of decomposition gas can be suppressed when impregnated into carbon fiber (A) and organic fiber (B), and the generation of voids can be suppressed during molding. Furthermore, the generation of gas can be suppressed, particularly during molding at high temperatures.

In the present invention, the heat loss refers to the weight loss rate of component (D) before and after heating under the above heating conditions, with the weight of component (D) before heating being taken as 100%, and can be calculated by the following formula: The weight before and after heating can be determined by measuring the weight at the molding temperature by thermogravimetric analysis (TGA) using a platinum sample pan under conditions of an air atmosphere and a heating rate of 10° C./min.
Loss on heating [wt %]={(weight before heating−weight after heating)/weight before heating}×100.

In addition, it is preferable that the melt viscosity change rate of component (D) after heating at 200°C for 2 hours is 2% or less. By keeping the melt viscosity change rate at 2% or less, even when the composite fiber bundle (E) is produced over a long period of time, uneven adhesion and the like can be suppressed, and the composite fiber bundle (E) can be produced stably. The melt viscosity change rate is more preferably 1.5% or less, and even more preferably 1.3% or less.

The melt viscosity change rate of component (D) can be determined by the following method. First, a 40 mm parallel plate is used to measure the melt viscosity at 200° C. at 0.5 Hz with a viscoelasticity measuring device. After component (D) is left to stand in a hot air dryer at 200° C. for 2 hours, the melt viscosity at 200° C. is similarly measured, and the viscosity change rate is calculated by the following formula:
Melt viscosity change rate [%] = {| (melt viscosity at 200 ° C before heating at 200 ° C for 2 hours - melt viscosity at 200 ° C after heating at 200 ° C for 2 hours) | / (melt viscosity at 200 ° C before heating at 200 ° C for 2 hours)} × 100.

In the present invention, the epoxy resin preferably used as component (D) is a compound having two or more epoxy groups, substantially does not contain a curing agent, and does not cure by so-called three-dimensional crosslinking even when heated. The epoxy resin has epoxy groups, which makes it easier to interact with the carbon fiber (A) and the organic fiber (B). Therefore, it is more compatible with the carbon fiber (A) and the organic fiber (B) that make up the composite fiber bundle (E) during impregnation, and the dispersibility of the carbon fiber (A) and the organic fiber (B) during molding is further improved.

Here, examples of epoxy resins that are preferably used as component (D) include glycidyl ether type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, and alicyclic epoxy resins. Two or more of these may be used.

Among these, glycidyl ether type epoxy resins are preferred because they have an excellent balance between viscosity and heat resistance, and bisphenol A type epoxy resins and bisphenol F type epoxy resins are more preferred.

The number average molecular weight of the epoxy resin used as component (D) is preferably 200 to 5000. If the number average molecular weight of the epoxy resin is 200 or more, the mechanical properties of the molded product can be further improved. 800 or more is more preferable, and 1000 or more is even more preferable. On the other hand, if the number average molecular weight of the epoxy resin is 5000 or less, the impregnation of the carbon fiber (A) and organic fiber (B) constituting the composite fiber bundle (E) is excellent, and the dispersibility of the carbon fiber (A) and organic fiber (B) in the molded product can be further improved. The number average molecular weight is more preferably 4000 or less, and even more preferably 3000 or less. The number average molecular weight of the epoxy resin can be measured using gel permeation chromatography (GPC).

Examples of terpene resins include polymers or copolymers obtained by polymerizing a terpene monomer, if necessary with an aromatic monomer, in an organic solvent in the presence of a Friedel-Crafts catalyst.

In particular, α-pinene, β-pinene, dipentene, and d-limonene are preferred as terpene monomers because they have excellent compatibility with the thermoplastic resin (C), and homopolymers of these terpene monomers are even more preferred.

It is also possible to use hydrogenated terpene resins obtained by hydrogenating these terpene resins, and terpene phenol resins obtained by reacting a terpene monomer with a phenol in the presence of a catalyst. Here, the phenols preferably have 1 to 3 substituents on the benzene ring of the phenol, at least one of which is selected from the group consisting of an alkyl group, a halogen atom, and a hydroxyl group. Of these, phenol and cresol are preferred. Of these, hydrogenated terpene resins are preferred because they have better compatibility with thermoplastic resins (C), particularly polypropylene resins.

The glass transition temperature of the terpene resin is not particularly limited, but is preferably 30 to 100°C. If the glass transition temperature is 30°C or higher, the component (D) is easy to handle during molding. If the glass transition temperature is 100°C or lower, the fluidity of the component (D) during molding can be appropriately suppressed, improving moldability.

The number average molecular weight of the terpene resin is preferably 200 to 5000. If the number average molecular weight is 200 or more, the mechanical properties, particularly the impact properties, of the molded article can be further improved. If the number average molecular weight is 5000 or less, the viscosity of the terpene resin is appropriately low, so that the resin has excellent impregnation properties into the carbon fiber (A) and the organic fiber (B), and the dispersibility of the carbon fiber (A) and the organic fiber (B) in the molded article can be further improved. The number average molecular weight of the terpene resin can be measured using gel permeation chromatography (GPC).

The content of component (D) in the molding material of the present invention is preferably 1 to 20 parts by weight per 100 parts by weight of the total of carbon fiber (A), organic fiber (B), and thermoplastic resin (C). If the content of component (D) is less than 1 part by weight, the fluidity and dispersibility of carbon fiber (A) and organic fiber (B) during the production of a molded product will decrease. The content of component (D) is preferably 2 parts by weight or more, and more preferably 4 parts by weight or more. On the other hand, if the content of component (D) exceeds 20 parts by weight, the bending strength, tensile strength, and impact properties of the molded product will decrease. It is preferably 15 parts by weight or less, more preferably 12 parts by weight or less, and even more preferably 10 parts by weight or less.

As a specific shape of the molding material of the present invention, a columnar body having a cross section as shown in Figures 1 to 4 can be exemplified. In such a columnar body, it is preferable that the carbon fiber (A) and the organic fiber (B) are aligned almost parallel to the axial direction of the columnar body, and the length of the carbon fiber (A) and the organic fiber (B) is substantially the same as the length of the molding material. Since the fiber length is substantially the same as the length of the molding material, the fiber length of the carbon fiber (A) and the organic fiber (B) in the molded product produced using it can be easily controlled and can be relatively long, so that a molded product with better mechanical properties can be obtained. In addition, "allocated almost parallel" refers to a state in which the axis of the long axis of the fiber bundle containing the carbon fiber (A) and the organic fiber (B) and the axis of the long axis of the molding material are oriented in the same direction, and the angular deviation between the axes is preferably 20° or less, more preferably 10° or less, and even more preferably 5° or less. The length of the molding material is the length in the fiber bundle orientation direction in the molding material, and in the case of the above-mentioned columnar body, it is the length in the long axis direction of the columnar body. Furthermore, "substantially the same length" means that the fiber bundles are not intentionally cut within the molding material, and fiber bundles significantly shorter than the overall length of the molding material are not substantially included. In particular, there is no limitation on the amount of fiber bundles shorter than the overall length of the molding material, but the content of fiber bundles with a length of 50% or less of the overall length of the molding material is preferably 30% by mass or less, and more preferably 20% by mass or less, of the total fiber bundles. More preferably, the content of fiber bundles with a length of 85% or more of the overall length of the molding material is preferably 80% by mass or more, and more preferably 90% by mass or more.

It is preferable that the molding material has a substantially identical cross-sectional shape continuously for a certain length in the longitudinal direction. The longitudinal length of the molding material is in the range of 2 mm to 10 mm. If it is less than 2 mm, the reinforcing effect of the fibers is poor. In other words, if molding is performed using a molding material of less than 2 mm, the weight average fiber length of the organic fibers in the resulting molded product cannot be sufficiently long, resulting in poor impact properties. The molding material is preferably 3 mm or more, more preferably 5 mm or more, and even more preferably 7 mm or more. On the other hand, if the molding material exceeds 10 mm, the moldability during injection molding decreases. In other words, if the length of the molding material exceeds 10 mm, the molding material is too long to be caught in the injection molding machine. This reduces moldability. The molding material is preferably 9 mm or less, and more preferably 7 mm or less.

In addition, when the molding material of the present invention having the above-mentioned configuration is injection molded into a molded product under the conditions of a back pressure of 3 MPa and an injection speed of 30 mm/s, the weight average fiber length _Lwb of the organic fiber (B) in the molded product is likely to be 60% or more of the length of the starting molding material. When _Lwb is 60% or more of the length of the molding material, the fiber reinforcing effect of the organic fiber (B) in the molded product is likely to be exhibited, and the impact properties of the molded product are improved. It is more preferable that _Lwb is 70% or more. In the examples described later, _Lwb is measured in an ISO dumbbell test piece, but the molded product is not limited to this. The method of measuring Lwb of the organic fiber (B) in the molded product is the same as the method of measuring _Lwb of the organic fiber in the molded product.

The molding material of the present invention preferably has a fiber bundle containing continuous fiber bundles of carbon fiber (A) and organic fiber (B) in a thermoplastic resin (C). In other words, it is preferable to have a configuration in which the thermoplastic resin (C) is arranged on the outside of the fiber bundle. The thermoplastic resin (C) may contain component (D), and a composite fiber bundle (E) may be formed in which component (D) is filled between each single fiber of the fiber bundle, and thermoplastic resin (C) may be arranged on the outside. The composite fiber bundle (E) is formed by impregnating a fiber bundle with component (D), and is in a state in which carbon fiber (A) and organic fiber (B) are dispersed like islands in a sea of component (D).

The molding material of the present invention preferably has a core-sheath structure in which the fiber bundle or composite fiber bundle (E) is covered with the thermoplastic resin (C). The thermoplastic resin (C) that forms the sheath structure may contain other components as necessary to form a thermoplastic resin composition. Here, the "covered structure" refers to a structure in which a composition containing the thermoplastic resin (C) (hereinafter, the composition may also be simply referred to as "thermoplastic resin (C)") is disposed on and adhered to the surface of the fiber bundle or composite fiber bundle (E).

Component (D) contained in the molding material of the present invention is often low molecular weight, and is usually a relatively brittle and easily crushed solid or liquid at room temperature. By including thermoplastic resin (C) on the outside of the composite fiber bundle (E), the high molecular weight thermoplastic resin (C) protects the composite fiber bundle (E), suppresses crushing and scattering of component (D) due to impacts and abrasions during transportation and handling of the molding material, and maintains the shape of the molding material. From the viewpoint of handleability, it is preferable that the molding material of the present invention maintains the above-mentioned shape until it is used for molding.

The composite fiber bundle (E) and the thermoplastic resin (C) may be in a state where the thermoplastic resin (C) partially penetrates into a part of the composite fiber bundle (E) near the boundary, so that they are compatible with each other, or the composite fiber bundle (E) may be in a state where the thermoplastic resin (C) is impregnated into the composite fiber bundle (E).

In the molding material of the present invention, it is preferable that the carbon fiber (A) and the organic fiber (B) are unevenly distributed in the fiber bundle cross section. Here, the fiber bundle cross section refers to a cross section perpendicular to the fiber longitudinal direction of the fiber bundle. By unevenly distributing the carbon fiber (A) and the organic fiber (B) in the fiber bundle cross section, the entanglement of the carbon fiber (A) and the organic fiber (B) during molding can be suppressed, and a molded product in which the carbon fiber (A) and the organic fiber (B) are uniformly dispersed can be obtained. Therefore, the impact properties of the molded product can be further improved. Here, in the present invention, "uneven distribution" refers to the fact that the carbon fiber (A) and the organic fiber (B) are not evenly distributed in all regions of the fiber bundle cross section, but are partially unevenly distributed. For example, in the fiber bundle cross section as shown in Fig. 1, a form in which the carbon fiber (A) 1 contains the organic fiber (B) 2, a form in which the organic fiber (B) 2 contains the carbon fiber (A) 1, a so-called core-sheath type structure, and a structure in which the bundle of the carbon fiber (A) 1 and the bundle of the organic fiber (B) 2 are present in a state separated by a certain boundary portion in the fiber bundle cross section as shown in Fig. 3, are examples of the "uneven distribution" in the present invention. In the present invention, "inclusion" refers to a form in which the carbon fiber (A) is arranged in the core and the organic fiber (B) is arranged in the sheath, or a form in which the organic fiber (B) is arranged in the core and the carbon fiber (A) is arranged in the sheath. In the case of the form shown in Fig. 3, at least a part of each of the carbon fiber (A) and the organic fiber (B) is in contact with the thermoplastic resin (C) 3 of the outer layer in the fiber bundle cross section. In this case, the embodiment in which the carbon fiber (A) or the organic fiber (B) is in contact with the thermoplastic resin (C) 3 also includes the embodiment in which the carbon fiber (A) or the organic fiber (B) is in contact with the thermoplastic resin (C) 3 via the component (D), as shown in FIG. 4.

In the present invention, a method for confirming that the carbon fibers (A) and the organic fibers (B) are unevenly distributed in the fiber bundle can be, for example, a method of observing a cross section perpendicular to the longitudinal direction of the fibers of the molding material using an optical microscope set at a magnification of 300 times, and then performing image processing and analysis of the obtained microscopic image.

One method for unevenly distributing the carbon fiber (A) and organic fiber (B) in the cross section of the fiber bundle is to align bundles of carbon fiber (A) and bundles of organic fiber (B) to produce the molding material. By aligning each bundle to produce the molding material, the carbon fiber (A) and organic fiber (B) exist as independent fiber bundles, and can be unevenly distributed. By increasing the number of single fibers in the bundles of carbon fiber (A) and organic fiber (B) used, the bundles can be made larger, and by decreasing the number of single fibers, the bundles can be made smaller, so it is possible to vary the size of the bundles to cause uneven distribution.

There are no particular limitations on the carbon fiber (A), but it is preferable to use a fiber bundle containing 100 to 350,000 carbon fibers, and from the viewpoint of productivity, it is more preferable to use a fiber bundle containing 20,000 to 100,000 fibers. On the other hand, when polyester fiber or liquid crystal polyester fiber is used as the organic fiber (B), there are no particular limitations on the number of fibers, but it is preferable to use a fiber bundle containing 1 to 2,000 fibers, and from the viewpoint of productivity and suppressing entanglement of fibers in the molded product, it is more preferable to use a fiber bundle containing 10 to 1,000 fibers, and it is even more preferable to use a fiber bundle containing 30 to 700 fibers.

By molding using the above molding material, it is possible to obtain a molded product that has excellent dispersion of carbon fiber (A) and organic fiber (B) and has excellent bending strength, impact properties, appearance quality (black color), and quietness.

Next, a method for producing the molding material will be described. The molding material of the present invention can be obtained, for example, by the following method.

First, a roving of carbon fiber (A) and a roving of organic fiber (B) are combined in parallel with respect to the longitudinal direction of the fibers to produce a fiber bundle having carbon fiber (A) and organic fiber (B). Next, the fiber bundle is impregnated with molten component (D) to produce a composite fiber bundle (E). Furthermore, the composite fiber bundle (E) is guided to an impregnation die filled with a composition containing molten thermoplastic resin (C), and the thermoplastic resin (C) is coated on the outside of the composite fiber bundle (E), and the composite fiber bundle (E) is drawn through a nozzle. After cooling and solidifying, the composite fiber bundle is pelletized to a predetermined length to obtain a molding material (form I). The thermoplastic resin (C) may be impregnated into the fiber bundle as long as it is disposed at least on the outside of the composite fiber bundle (E).

The molding material produced by the above method, in which the composite fiber bundle (E) is coated with the thermoplastic resin (C), may be pellet-blended with pellets containing the thermoplastic resin (C) (not containing the carbon fiber (A) or the organic fiber (B)) to obtain a molding material mixture. This makes it easy to adjust the content of the carbon fiber (A) and the organic fiber (B) in the molded product. Pellet blending differs from melt kneading in that multiple materials are stirred and mixed at a temperature at which the resin components do not melt, to make them substantially uniform, and is preferably used when using a pellet-shaped molding material, such as in injection molding or extrusion molding.

The present invention also includes a molding material obtained by pellet blending pellets of carbon fiber (A) coated with thermoplastic resin (C) and pellets of organic fiber (B) coated with the same or different thermoplastic resin (C) as the previous pellets. In this embodiment, it is more preferable to impregnate at least carbon fiber (A) with component (D). Specifically, for example, it is preferable to prepare a carbon fiber reinforced thermoplastic resin molding material (X) (sometimes referred to as "carbon fiber reinforced molding material (X)") containing at least carbon fiber (A), thermoplastic resin (C), and component (D) and an organic fiber reinforced thermoplastic resin molding material (Y) (sometimes referred to as "organic fiber reinforced molding material (Y)") containing at least organic fiber (B), thermoplastic resin (F), and component (G), and to pellet blend these.

The carbon fiber reinforced molding material (X) preferably has a configuration including a composite fiber bundle (H) formed by impregnating carbon fiber (A) with component (D), and including a thermoplastic resin (C) on the outside of the composite fiber bundle (H). The carbon fibers (A) are preferably arranged substantially parallel to the axial direction of the carbon fiber reinforced molding material (X), and the length of the carbon fiber reinforced molding material (X) is preferably 2 to 10 mm. At the same time, it is preferable that the length of the carbon fiber (A) and the length of the carbon fiber reinforced molding material (X) are substantially the same.

The organic fiber reinforced molding material (Y) preferably has a configuration including a composite fiber bundle (I) formed by impregnating organic fiber (B) with component (G), and including a thermoplastic resin (F) on the outside of the composite fiber bundle (I). Note that the compound exemplified in component (D) described above can also be used for component (G), and in that case, component (D) and component (G) may be the same compound or different compounds. The resin exemplified in thermoplastic resin (C) described above can be used for thermoplastic resin (F), and thermoplastic resin (C) and thermoplastic resin (F) may be the same compound or different compounds.

It is preferable that the organic fibers (B) are arranged almost parallel to the axial direction of the organic fiber reinforced molding material (Y), and the length of the organic fiber reinforced molding material (Y) is preferably 2 to 10 mm. At the same time, it is preferable that the length of the organic fibers (B) and the length of the organic fiber reinforced molding material (Y) are substantially the same.

Here, "arranged almost parallel" means that in the carbon fiber reinforced molding material (X) and the organic fiber reinforced molding material (Y), the axis of the long axis of the fiber bundle and the axis of the long axis of the molding material containing them are oriented in the same direction, and the angular deviation between the axes is preferably 20° or less, more preferably 10° or less, and even more preferably 5° or less. Also, "substantially the same length" means that in the carbon fiber reinforced molding material (X) and the organic fiber reinforced molding material (Y), the content of fiber bundles with a length of 50% or less of the total length of the molding material is 30% by mass or less of the total fiber bundles, and more preferably 20% by mass or less. More preferably, the content of fiber bundles with a length of 85% or more of the total length is 80% by mass or more, and even more preferably 90% by mass or more.

The carbon fiber reinforced molding material (X) preferably contains 5 to 45 parts by weight of carbon fiber (A), 10 to 94 parts by weight of thermoplastic resin (C), and 1 to 20 parts by weight of component (D) per 100 parts by weight of the total of carbon fiber (A), thermoplastic resin (C), and component (D). The organic fiber reinforced molding material (Y) preferably contains 1 to 45 parts by weight of organic fiber (B), 10 to 98 parts by weight of thermoplastic resin (F), and 1 to 20 parts by weight of component (G) per 100 parts by weight of the total of organic fiber (B), thermoplastic resin (F), and component (G).

It is preferable to mix 50 to 80 parts by weight of the carbon fiber reinforced molding material (X) and 20 to 50 parts by weight of the organic fiber reinforced molding material (Y) with respect to a total of 100 parts by weight of the carbon fiber reinforced molding material (X) and the organic fiber reinforced molding material (Y). Furthermore, when the carbon fiber reinforced molding material (X) and the organic fiber reinforced molding material (Y) are made into a pellet blend (mixture), it is preferable to prepare the mixture as a whole so that, with respect to a total of 100 parts by weight of the carbon fiber (A), the organic fiber (B), the thermoplastic resin (C), and the component (D), the carbon fiber (A) is 5 to 45 parts by weight, the organic fiber (B) is 1 to 45 parts by weight, the thermoplastic resin (C) is 10 to 93 parts by weight, and the component (D) is 1 to 20 parts by weight. In calculating such a ratio, the thermoplastic resin used as the thermoplastic resin (F) is entered as the thermoplastic resin (C), and when a component corresponding to the component (D) is used as the component (G), the component (G) is counted as the component (D).

Next, we will explain the manufacturing method of the molded product of the present invention.

By molding using the molding material of the present invention described above, a molded product can be obtained that has excellent dispersibility of the carbon fiber (A) and the organic fiber (B) and has excellent bending strength, impact properties, and appearance quality (black color). As a molding method, a molding method using a mold is preferable, and various molding methods such as injection molding, extrusion molding, and press molding can be used. In particular, a molding method using an injection molding machine can continuously obtain stable molded products. There are no particular regulations regarding the conditions of injection molding, but for example, the injection time is preferably 0.5 to 10 seconds, more preferably 2 to 10 seconds. The back pressure is preferably 0.1 MPa or more, more preferably 1 MPa or more, even more preferably 2 MPa or more, and most preferably 3 MPa or more. The upper limit is preferably 50 MPa or less, more preferably 30 MPa or less, even more preferably 20 MPa or less, and most preferably 10 MPa or less. The injection speed is preferably 1 mm/s to 200 mm/s, more preferably 10 mm/s to 150 mm/s, and even more preferably 20 mm/s to 100 mm/s. The screw rotation speed is preferably 10 rpm to 200 rpm, more preferably 30 rpm to 150 rpm, and even more preferably 50 rpm to 100 rpm. The dwell pressure is preferably 1 MPa to 50 MPa, more preferably 1 MPa to 30 MPa. The dwell time is preferably 1 second to 20 seconds, more preferably 5 seconds to 20 seconds. The cylinder temperature is preferably 200°C to 320°C, and the mold temperature is preferably 20°C to 100°C. Here, the cylinder temperature refers to the temperature of the part of the injection molding machine where the molding material is heated and melted, and the mold temperature refers to the temperature of the mold into which the resin is injected to form a predetermined shape. By appropriately selecting these conditions, particularly the injection time, back pressure, and mold temperature, the fiber length of the carbon fibers such as carbon fibers and organic fibers in the molded product can be easily adjusted.

The molded article of the present invention obtained in this manner has excellent mechanical properties, particularly bending strength and impact properties, and excellent appearance (black color).

The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to the description of these examples. First, the evaluation methods for various properties used in the examples will be explained.

(1) Melt Viscosity Measurement The melt viscosity of the thermoplastic resin (C) and component (D) used in each of the Examples and Comparative Examples was measured at 200° C. with a viscoelasticity measuring device at 0.5 Hz using a 40 mm parallel plate.

(2) Measurement of weight-average fiber length The ISO dumbbell test pieces obtained in each Example and Comparative Example were heated while sandwiched between glass plates on a hot stage set at 200 to 300°C, and the fibers were uniformly dispersed in a film. The film in which the carbon fibers (A) and the organic fibers (B) were uniformly dispersed was observed under an optical microscope (50 to 200 times). The fiber lengths of 1,000 randomly selected carbon fibers (A) and 1,000 randomly selected organic fibers (B) were measured, and the weight-average fiber length was calculated from the following formula.
Average fiber length=Σ( ^Mi2 ×Ni)/Σ(Mi×Ni)
Mi: fiber length (mm)
Ni: number of fibers of fiber length Mi.

(3) Fiber strength and initial modulus of elasticity The fiber strength of the organic fiber (B) was determined by a single-fiber tensile test. The tensile test was performed in a room under standard conditions (20°C, 65% RH) with a gripping distance of 250 mm and a pulling speed of 300 mm/min, and the load at fiber break was divided by the single fiber fineness to calculate the strength. (However, if the fiber breaks near the chuck, it is considered to be a chuck break and is excluded from the data.) The initial fiber modulus of elasticity was calculated from the initial gradient of the stress-strain curve obtained at that time.

(4) Fiber Fineness Measurement The single fiber fineness of the organic fiber (B) used in each Example and Comparative Example was determined using a single yarn of the organic fiber (B) according to JIS L 1013:2010.

(5) Fiber Density Measurement The density of the organic fiber (B) used in each Example and Comparative Example was determined in accordance with JIS L 1015:2010.

(6) Measurement of bending strength of molded products The bending strength of the ISO dumbbell test pieces obtained in each Example and Comparative Example was measured in accordance with ISO 178 using a three-point bending test jig (indenter radius 5 mm) with a support distance set to 64 mm and a test speed of 2 mm/min. The test machine used was an "Instron (registered trademark)" universal testing machine Model 5566 (manufactured by Instron Corporation). The measurement was performed three times, and the average value was calculated as the bending strength of each Example and Comparative Example.

(7) Measurement of Charpy impact strength of molded products Parallel sections were cut out from the ISO dumbbell test pieces obtained in each Example and Comparative Example, and a V-notched Charpy impact test was carried out in accordance with ISO 179 using a C1-4-01 model testing machine manufactured by Tokyo Test Instruments Co., Ltd. The measurement was carried out five times, and the average value was calculated as the impact strength (kJ/m ² ) of each Example and Comparative Example.

(8) Evaluation of fiber dispersion of molded products For the test pieces of 80 mm x 80 mm x 3 mm thickness obtained in each Example and Comparative Example, the number of undispersed carbon fiber bundles (CF bundles) present on both the front and back surfaces was visually counted. The evaluation was performed on 50 molded products, and the fiber dispersion of the total number was judged according to the following criteria, with A and B being considered as passing.
A: Less than 1 undispersed CF bundle. B: 1 or more undispersed CF bundle. C: 3 or more undispersed CF bundles.

(9) Color Tone Evaluation of Organic Fiber (B) and Molded Article For the test pieces of 80 mm x 80 mm x 3 mm thickness obtained in each Example and Comparative Example, a spectrophotometer (SD7000, Nippon Denshoku Kogyo Co., Ltd.) was used to measure L ^* in the appearance of the molded article surface. The measurement was performed three times, and the average value was used for the evaluation of each Example and Comparative Example. In addition, the organic fiber (B) was set in the measuring instrument in the state of a strand bundle, and the L ^* a ^* b ^* on the surface of the organic fiber (B) was measured. Similarly, three measurements were performed, and the average value was used for the evaluation of each Example and Comparative Example.

(10) Evaluation of Transmission Loss of Molded Articles Each test piece of 80 mm x 80 mm x 3 mm thickness obtained in each Example and Comparative Example was processed into a shape of φ100. The obtained molded articles were measured using a transmission type acoustic chamber (Bruel & Kjaer 4206-T type + UA-1630) with a frequency band of 50 Hz to 6500 Hz set as the measurement range. Measurements were performed in all frequency bands, and the measured value at 6000 Hz was calculated as the transmission loss of each Example and Comparative Example.

(11) Proportion of weight average fiber length _Lwb of organic fiber (B) in molded article The obtained long fiber pellets were injection molded under the injection molding conditions of the Examples described later, but with a back pressure of 3 MPa during molding, to prepare ISO dumbbell test pieces (Type A1) in the same manner. The weight average fiber length _Lwb of the organic fiber (B) was calculated for the obtained test pieces (molded articles) in the same manner as in (2). Then, 50 long fiber pellets used in each Example were randomly selected, and the ratio of the length to the _Lwb calculated from the molded article used in each Example was calculated from the following formula.
Weight average fiber length ratio of organic fiber (B) in molded article=(weight average fiber length L _wb of organic fiber (B))/(pellet length of long fiber pellets)×100.

<Preparation of carbon fiber (A)>
A copolymer mainly composed of polyacrylonitrile was spun, baked, and surface-oxidized to obtain a continuous carbon fiber having a total number of single fibers of 24,000, a single fiber diameter of 7 μm, a mass per unit length of 1.6 g/m, a specific gravity of 1.8 g/cm ³ , and a surface oxygen concentration ratio [O/C] of 0.2. The strand tensile strength of this continuous carbon fiber was 4,880 MPa, and the strand tensile modulus was 225 GPa. Next, a sizing agent mother liquid was prepared by dissolving glycerol polyglycidyl ether as a polyfunctional compound in water to a concentration of 2% by weight, and the sizing agent was applied to the carbon fiber by the immersion method, followed by drying at 230° C. The amount of sizing agent attached to the carbon fiber thus obtained was 1.0% by weight.

<Organic fiber (B)>
(B-1)
Orange polyester fiber (manufactured by Toray Industries, Inc., "Tetoron (registered trademark)" 1670T-144-706C, strength: 7.5 cN/dtex, melting point: 260° C., energy propagation speed: 2.8 km/s) was used.
(B-2)
A liquid crystal polyester fiber (Toray Industries, Inc., "Sciberas" (registered trademark) 1700T-288f, strength: 23.5 cN/dtex, melting point: 330° C., energy propagation speed: 17.3 km/s) was used.
(B-3)
A blue polyester fiber (manufactured by Toray Industries, Inc., "Tetoron (registered trademark)" 1670T-144-706C, strength: 7.4 cN/dtex, melting point: 260° C., energy propagation speed: 2.8 km/s) was used.
(B-4)
A white polyester fiber (manufactured by Toray Industries, Inc., "Tetoron (registered trademark)" 1670T-108-705C, strength: 7.8 cN/dtex, melting point: 260° C., energy propagation speed: 2.7 km/s) was used.
(B-5)
A black polyester fiber (strength: 4.0 cN/dtex, melting point: 260° C., energy propagation speed: 1.5 km/s) was prepared using a known manufacturing method and was used, with the carbon black content being 10% by weight relative to the total weight of the fiber.
(B-6)
A PAN-based flame-retardant fiber (manufactured by Toho Tenax Co., Ltd., "Pyromex" (registered trademark) CPX-1.6d", strength: 2.0 cN/dtex, melting point: none (insoluble), energy propagation speed: 1.2 km/s) was used.
(B-7)
Polyamide fiber (manufactured by Toray Industries, Inc., "Amilan (registered trademark)" 1870T-192-720, strength: 6.5 cN/dtex, melting point: 215°C, energy propagation speed: 1.7 km/s) was used.

<Thermoplastic resin (C)>
(C-1)
A pellet blend of polypropylene resin (Prime Polypro J137G manufactured by Prime Polymer Co., Ltd.) and maleic acid modified polypropylene resin (Admer QE840 manufactured by Mitsui Chemicals, Inc.) in a weight ratio of 85/15 was used. The melt viscosity at 200°C was measured by the method described in (1) above and found to be 50 Pa s.
(C-2)
A polycarbonate resin (Teijin Chemicals Limited, "Panlite" (registered trademark) L-1225L) was used. The melt viscosity at 200°C was measured by the method described in (1) above and found to be 14,000 Pa·s.
(C-3)
A polyamide 6 resin ("Amilan" (registered trademark) CM1001, manufactured by Toray Industries, Inc.) was used. The melt viscosity at 200°C was measured by the method described in (1) above and found to be 1000 Pa·s.

<Component (D)>
(D-1)
A solid hydrogenated terpene resin (Yasuhara Chemical Co., Ltd., Clearon (registered trademark) P125, softening point 125°C) was used. This was placed in a tank in an impregnation aid application device, the temperature in the tank was set to 200°C, and the resin was heated for 1 hour to make it molten. The melt viscosity at 200°C at this time was measured by the method described in (1) above and found to be 1 Pa·s, and the rate of change in melt viscosity was calculated to be 1.2%.
(D-2)
A solid bisphenol A type epoxy resin (jER1004AF(E-2), softening point 97°C, manufactured by Mitsubishi Chemical Corporation) was used as component (D) when a polycarbonate resin was used as the thermoplastic resin (C). The melt viscosity of this was measured by the method described in (1) above in the same manner as for the above-mentioned P125, and was found to be 1 Pa·s. The rate of change in melt viscosity was calculated to be 1.1%.
(D-3)
A solid terpene phenol resin ("Mighty Ace" (registered trademark) K140 manufactured by Yasuhara Chemical Co., Ltd., softening point 140°C) was used. This was placed in a tank in an impregnation aid application device, the temperature in the tank was set to 200°C, and the resin was heated for 1 hour to make it molten. The melt viscosity at 200°C at this time was measured by the method described in (1) above and found to be 0.8 Pa·s, and the rate of change in melt viscosity was calculated to be 1.0%.

(J-1)
Furnace black (manufactured by Mitsubishi Chemical Corporation, "Mitsubishi Carbon Black" MA100) was used.

(K-1)
As the vibration damping agent, a glycidyl dimethacrylate modified polyethylene copolymer ("Bondfast BF-7L" manufactured by Sumitomo Chemical Co., Ltd.) was used.

Example 1
A long fiber reinforced resin pellet manufacturing device having a coating die for a wire coating method installed at the tip of a TEX-30α type twin screw extruder (screw diameter 30 mm, L/D = 32) manufactured by Japan Steel Works, Ltd. was used, the extruder cylinder temperature was set to 220°C, and the thermoplastic resin (C-1) shown above was fed from the main hopper and melt-kneaded at a screw rotation speed of 200 rpm. The component (D-1) was heated and melted at 200°C, and the discharge amount was adjusted to 8.7 parts by weight per 100 parts by weight of the total of (A) to (C) (8.0 parts by weight per 100 parts by weight of the total of (A) to (D)). The component (D-1) was applied to a fiber bundle consisting of carbon fiber (A) and organic fiber (B-1) to form a composite fiber bundle (E). The composite fiber bundle (E) was then fed to a die opening (diameter 3 mm) for discharging a composition containing molten thermoplastic resin (C-1), so that the periphery of the carbon fiber (A) and the organic fiber (B-1) was continuously covered with the composition containing thermoplastic resin (C-1). At this time, the carbon fiber (A) and the organic fiber (B-1) were unevenly distributed in the internal cross section of the composite fiber bundle (E). As shown in FIG. 3, the uneven distribution state was such that at least a part of each of the carbon fiber (A) and the organic fiber (B-1) was in contact with the composition containing thermoplastic resin (C-1). The obtained strand was cooled and then cut with a cutter to a pellet length of 7 mm to obtain long fiber pellets. At this time, the take-up speed was adjusted so that the carbon fiber (A) was 20 parts by weight and the organic fiber (B-1) was 5 parts by weight per 100 parts by weight of the total of (A) to (C). The length of the carbon fiber (A) and the organic fiber (B-1) in the obtained long fiber pellets was substantially the same as the pellet length.

The long fiber pellets thus obtained were injection molded using an injection molding machine (J110AD manufactured by Japan Steel Works, Ltd.) under the following conditions: injection time: 2 seconds, back pressure: 5 MPa, holding pressure: 20 MPa, holding time: 10 seconds, injection speed: 30 mm/s, screw rotation speed: 80 rpm, cylinder temperature: 230°C, and mold temperature: 60°C to produce ISO dumbbell test pieces (Type A1) and 80 mm x 80 mm x 3 mm test pieces as molded products. Here, the cylinder temperature refers to the temperature of the part of the injection molding machine where the molding material is heated and melted, and the mold temperature refers to the temperature of the mold into which the resin is injected to form a predetermined shape. The obtained test pieces (molded products) were left to stand for 24 hours in a constant temperature and humidity chamber adjusted to a temperature of 23°C and 50% RH, and then subjected to characteristic evaluation. The evaluation results evaluated by the above-mentioned method are summarized in Table 1.

(Examples 2 and 5, Reference Examples 3 and 4 )
Molded articles were produced and evaluated in the same manner as in Example 1, except that the composition ratio or the type of fibers used was changed as shown in Table 1. The evaluation results are shown in Table 1.

( Reference Example 6)
Molded articles were produced and evaluated in the same manner as in Example 1, except that the thermoplastic resin (C) was changed to (C-2), the organic fiber (B) to (B-2), the component (D) to (D-2), the extruder cylinder temperature was set to 300° C., and the injection molding machine cylinder temperature was changed to 300° C. and the mold temperature was changed to 80° C. The evaluation results are shown in Table 1.

( Reference Examples 7 and 8)
Molded articles were produced and evaluated in the same manner as in Example 1, except that the thermoplastic resin (C) was changed to (C-3), the component (D) to (D-3), the extruder cylinder temperature was set to 270° C., and the injection molding machine cylinder temperature was changed to 270° C. and the mold temperature to 80° C. The evaluation results are shown in Table 1.

( Reference Example 9)
Except for setting the extruder cylinder temperature to 270° C., adding the vibration damping agent (K-1) in addition to the thermoplastic resin (C-3) and feeding them from the main hopper, changing the component (D) to (D-3), and further changing the injection molding cylinder temperature to 270° C. and the mold temperature to 80° C., a molded article was produced and evaluated in the same manner as in Example 1. The evaluation results are summarized in Table 1.

(Comparative Examples 1 to 6)
Molded articles were produced and evaluated in the same manner as in Example 1, except that the composition was changed as shown in Table 2. The evaluation results are shown in Table 2.

(Comparative Example 7)
Molded articles were produced and evaluated in the same manner as in Example 1, except that the composition was changed as shown in Table 2 and the molding temperature was changed to 200° C. The evaluation results are shown in Table 2.

(Comparative Example 8)
Except for changing the pellet length to 14 mm, a molded article was produced and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

(Comparative Example 9)
A fiber bundle consisting of the carbon fiber (A-1) and organic fiber (B-1) shown above was impregnated with the component (D) in the ratio shown in Table 2 to produce a composite fiber bundle (E). The composite fiber bundle was melt-kneaded together with a molten thermoplastic resin (A-1) in a Japan Steel Works, Ltd. TEX-30α type twin-screw extruder (screw diameter 30 mm, L/D = 32) with the screw rotation speed set to 200 rpm in a cylinder, and the strand discharged from the tip of the die was cooled and solidified, and then cut into pellets with a cutter to a pellet length of 7 mm to produce pellets. Molded products were produced and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

In all of the materials in Examples 1 to 6, carbon fiber (A), organic fiber (B) and component (D) were present in the molded product, and the molded product showed high bending strength, impact properties and excellent transmission loss. Since the color tone of the organic fiber (B) was specified, the L ^* of the molded product was low and whitening could be suppressed. In addition, even when the thermoplastic resin (C) was changed to polyamide 6 resin, the same excellent effect was exhibited. Furthermore, in Example 9, in which a vibration damping agent was added, high impact properties and excellent transmission loss were exhibited. On the other hand, in Comparative Example 1, the L ^* of the organic fiber (B) was high, resulting in poor appearance quality of the molded product. In Comparative Example 2, since the carbon fiber (A) was excessively contained, breakage occurred due to contact between the fibers, and the remaining fiber length was shortened, resulting in low impact strength. In Comparative Example 3, since the organic fiber (B) was not contained, the fiber reinforcement effect was weak, the impact properties were low and the transmission loss was low. In Comparative Example 4, which used black polyester fiber containing carbon black, the organic fiber contained carbon black and the energy transmission speed of the organic fiber was low, so the impact strength and transmission loss of the molded product obtained were poor. In Comparative Example 5, which used PAN-based flame-resistant yarn, the fiber strength was low, so the impact properties were low. In Comparative Example 6, the molded product was brittle and had low impact properties because of the inclusion of carbon black. In Comparative Example 7, the energy transmission speed of the organic fiber (B) was low, so the transmission loss was low. In Comparative Example 8, the _Lwb of the organic fiber (B) contained was long, so the appearance quality of the molded product was poor. In Comparative Example 9, the _Lwb of the organic fiber (B) was short, so the impact properties of the molded product were low and the transmission loss was low.

1 Carbon fiber (A)
2. Organic fiber (B)
3 Thermoplastic resin (C)
4. Component (D) having a melt viscosity at 200° C. lower than that of thermoplastic resin (C)

Claims (9)

A fiber-reinforced thermoplastic resin molded product comprising carbon fiber (A), colored organic fiber (B) containing at least one of a colorant other than black, an inorganic pigment, and an organic pigment, a thermoplastic resin (C), and a component (D) selected from an epoxy resin, a phenol resin, a terpene resin, and a cyclic polyarylene sulfide resin, the component (D) having a melt viscosity at 200°C lower than that of the thermoplastic resin (C), the fiber-reinforced thermoplastic resin molded product comprising 5 to 45 parts by weight of carbon fiber (A), 1 to 45 parts by weight of colored organic fiber (B), and 10 to 94 parts by weight of thermoplastic resin (C) relative to a total of 100 parts by weight of carbon fiber (A), the colored organic fiber (B), and the thermoplastic resin (C), and wherein L ^* in the CIELab color space of the colored organic fiber (B) is 25 to 70. , a value of -110 to +110 (excluding -1 to +4), b value of -110 to +110 (excluding -1 to +4) , fiber strength of 4 cN/dtex or more, and energy propagation speed represented by formula (1) of 2.0 km/s or more, the weight average fiber length (L _wa ) of the carbon fiber (A) in the fiber-reinforced thermoplastic resin molded product is 0.3 mm or more and 1.5 mm or less, and the weight average fiber length (L _wb ) of the colored organic fiber (B) is 2 mm or more and 10 mm or less. A fiber-reinforced thermoplastic resin molded product.

The fiber-reinforced thermoplastic resin molded product according to claim 1, wherein the L ^* of the colored organic fiber (B) is 25 to 50. The fiber-reinforced thermoplastic resin molded product according to claim 1 or 2, wherein the colored organic fiber (B) is a polyester fiber and/or a liquid crystal polyester fiber. The fiber-reinforced thermoplastic resin molded product according to any one of claims 1 to 3, wherein the thermoplastic resin (C) is at least one selected from the group consisting of polypropylene-based resins, polyamide resins, polycarbonate resins, and polyarylene sulfide resins. A fiber-reinforced thermoplastic resin molding material comprising carbon fiber (A), colored organic fiber (B) containing at least one of a colorant other than black, an inorganic pigment, and an organic pigment, a thermoplastic resin (C), and a component (D) selected from an epoxy resin, a phenol resin, a terpene resin, and a cyclic polyarylene sulfide resin, the component (D) having a melt viscosity at 200°C lower than that of the thermoplastic resin (C), the fiber-reinforced thermoplastic resin molding material comprising 5 to 45 parts by weight of carbon fiber (A), 1 to 45 parts by weight of colored organic fiber (B), 10 to 93 parts by weight of thermoplastic resin (C), and 1 to 20 parts by weight of component (D), relative to a total of 100 parts by weight of carbon fiber (A), the colored organic fiber (B), and the thermoplastic resin (C), and the colored organic fiber (B) has an L ^* of 25 to 70 in the CIELab color space. , a value of -110 to +110 (excluding -1 to +4), b value of -110 to +110 (excluding -1 to +4) , fiber strength of 4 cN/dtex or more, and energy propagation speed represented by formula (1) of 2.0 km/s or more, carbon fiber (A) and the colored organic fiber (B) are arranged substantially parallel to the axial direction, and the length of the carbon fiber (A) and the colored organic fiber (B) is substantially the same as the length of the fiber reinforced thermoplastic resin molding material, and the length of the fiber reinforced thermoplastic resin molding material in the longitudinal direction is 2 to 10 mm. A fiber reinforced thermoplastic resin molding material.

The fiber reinforced thermoplastic resin molding material according to claim 5, wherein L ^* of the colored organic fiber (B) is 25 to 50. 7. The fiber-reinforced thermoplastic resin molding material according to claim 5 or 6, wherein when a molded product is injection molded under conditions of a back pressure of 3 MPa and an injection speed of 30 mm / s, the weight average fiber length L _wb of the colored organic fiber (B) in the molded product is 60% or more of the molding material length. The fiber-reinforced thermoplastic resin molding material according to any one of claims 5 to 7, wherein the colored organic fiber (B) is a polyester fiber and/or a liquid crystal polyester fiber. The fiber-reinforced thermoplastic resin molding material according to any one of claims 5 to 8, wherein the thermoplastic resin (C) is at least one selected from the group consisting of polypropylene-based resins, polyamide resins, polycarbonate resins, and polyarylene sulfide resins.

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