Continuous Fiber Reinforced Resin Composite Material and Method for Producing the Same

Abstract

To provide a fiber-reinforced resin composite material having high vibration fatigue recovery characteristics and strength stability, and a method for producing the same.SOLUTION: A continuous fiber-reinforced resin composite material is a continuous fiber-reinforced resin composite material containing continuous reinforcement fibers and a thermoplastic resin, wherein an interface coating rate variation index represented by the following expression of the continuous fiber-reinforced resin composite material is 0.8 to 1.2. Expression: (interface coating rate variation index)=(interface coating rate of continuous fiber-reinforced resin composite material before destruction test) / (interface coating rate of continuous fiber-reinforced resin composite material after destruction test).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a continuous fiber reinforced resin composite material and a method for manufacturing the same.

Background Art

[0002] Composite material molded bodies in which a reinforcing material such as glass fiber is added to a matrix resin material are used for various structural parts of machines, automobiles, etc., pressure vessels, tubular structures, and the like. In particular, from the viewpoint of strength, a continuous fiber reinforced resin composite material in which the reinforcing fiber is a continuous fiber is desired. As this continuous fiber reinforced resin composite material, those in which the sizing agent added to the reinforcing fiber is devised (for example, see Patent Document 1 below), those in which the difference between the melting point and the crystallization temperature is devised (for example, see Patent Document 2 below), those in which an organic salt is added to the resin material (for example, see Patent Document 3 below), those in which a cloth of a preform is laminated with a thermoplastic resin (for example, see Patent Document 4 below), and those having good adhesion, affinity, etc. at the interface between the continuous reinforcing fiber and the resin (for example, see Patent Document 5 below) have been proposed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the continuous fiber reinforced resin composites of the prior art, since the interface thickness changes before and after the fracture test, there is room for improvement in that the interface recovery characteristics and the strength stability are not sufficient.

[0005] In view of such a prior art level, the problem to be solved by the present invention is to provide a fiber reinforced resin composite material having high vibration fatigue recovery characteristics and excellent strength stability, and a method for manufacturing the same.

Means for Solving the Problems

[0006] That is, the present invention is as follows. [1] A method for manufacturing a continuous fiber reinforced resin composite material, wherein the impregnation rate of the thermoplastic resin into the continuous reinforcing fibers is 0.8 to 1.2 times the impregnation rate of the thermoplastic resin into the coupling continuous reinforcing fibers treated only with a coupling agent, wherein the flexural strength of the coupling continuous fiber reinforced resin composite material composed of the coupling continuous reinforcing fibers and the thermoplastic resin is 0.6 times or more the flexural strength of the continuous fiber reinforced resin composite material, wherein the continuous reinforcing fibers are continuous reinforcing fibers to which a sizing agent containing an amino-silane-based silane coupling agent is attached, characterized in that it is a method for manufacturing a continuous fiber reinforced resin composite material. [2] The method for manufacturing a continuous fiber reinforced resin composite material according to claim 1, wherein the interfacial coating rate change index represented by the following formula of the continuous fiber reinforced resin composite material is 0.8 to 1.2. (Interfacial coating rate change index) = (Interfacial coating rate of the continuous fiber reinforced resin composite material before the fracture test) / (Interfacial coating rate of the continuous fiber reinforced resin composite material after the fracture test) [3] A method for manufacturing a continuous fiber reinforced resin composite material according to [1], including a step of setting the continuous reinforcing fibers and the thermoplastic resin in a mold, a melting step of melting the thermoplastic resin, and a compression step of compressing the mold to shape the continuous fiber reinforced resin composite material. A method for manufacturing a continuous fiber reinforced resin composite material. [4] The method for manufacturing a continuous fiber reinforced resin composite material according to [3], wherein the mold clamping pressure in the compression step is 1 MPa or more. [5] The method for manufacturing a continuous fiber reinforced resin composite material according to [1], including a step of installing the continuous reinforcing fibers and the thermoplastic resin in a mold and compressing them with a double belt press, or installing a mold frame so as to surround the four sides of the installed continuous reinforcing fibers and the thermoplastic resin and compressing them with a double belt press. [6] A method for manufacturing a continuous fiber reinforced resin composite material according to any one of [1] to [5], including a step of preparing a compression molding machine set at one or more temperatures for heating and a compression molding machine set at one or more temperatures for cooling, and sequentially inserting the mold in which the continuous reinforcing fibers and the thermoplastic resin are installed into the compression molding machine for molding.

Effects of the Invention

[0007] The continuous fiber reinforced resin composite material according to the present invention has high vibration fatigue recovery characteristics and excellent strength stability.

Modes for Carrying Out the Invention

[0008] Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as "the present embodiment") will be described in detail. It should be noted that the present invention is not limited to the following embodiments, and various modifications can be made and implemented within the scope of the gist thereof.

[0009] [Continuous Fiber Reinforced Resin Composite Material] The continuous fiber reinforced resin composite material (hereinafter also simply referred to as "composite material") of the present embodiment includes continuous reinforcing fibers and a thermoplastic resin, and the interfacial coating rate change index shown below is 0.8 to 1.2 before and after the fracture test. (Interfacial coating rate change index) = (Interfacial coating rate of the continuous fiber reinforced resin composite material before the fracture test) / (Interfacial coating rate of the composite material after the fracture test) The above interfacial coating rate change index is preferably 0.9 to 1.2, and more preferably 0.95 to 1.15.

[0010] In this specification, the interfacial coating rate (%) of the continuous fiber reinforced resin composite material refers to the relative elemental concentration of the component elements derived from the thermoplastic resin remaining on the surface of the continuous reinforcing fibers when the continuous reinforcing fibers after dissolving the thermoplastic resin from the continuous fiber reinforced resin composite material in a solvent are measured by X-ray photoelectron spectroscopy (XPS), and can be obtained from the ratio of the relative elemental concentration of the component elements derived from the thermoplastic resin remaining on the surface of the continuous reinforcing fibers to the total of the relative elemental concentration of the component elements derived from the continuous reinforcing fibers. The interfacial coating rate (the interfacial coating rate of the composite material before the fracture test) of the continuous fiber reinforced resin composite material of the present embodiment is preferably 3 to 44%, more preferably 10 to 40%, and still more preferably 20 to 37%.

[0011] The coating rate of the thermoplastic resin remaining on the surface of the continuous reinforcing fibers after dissolving the thermoplastic resin of the continuous fiber reinforced resin composite material of the present embodiment in a solvent (the interfacial coating rate of the continuous fiber reinforced resin composite material) can be measured, for example, by the following method. Immerse the continuous fiber reinforced resin composite material in a solvent to dissolve the thermoplastic resin contained in the composite material in the solvent. After removing the above solvent, wash the remaining composite material again with the fresh above solvent to remove the thermoplastic resin on the surface of the continuous reinforcing fiber. At this time, the thermoplastic resin that strongly binds to the sizing agent (preferably a coupling agent) on the surface of the continuous reinforcing fiber remains on the surface of the continuous reinforcing fiber, and only the thermoplastic resin that is not bound to the sizing agent is removed by the solvent. The interfacial coating rate (%) of the continuous fiber reinforced resin composite material can be obtained from the ratio of the relative elemental concentration of the component elements derived from the thermoplastic resin remaining on the surface of the continuous reinforcing fiber to the total of the relative elemental concentration of the component elements derived from the continuous reinforcing fiber when the composite material is measured by X-ray photoelectron spectroscopy (XPS) after drying.

[0012] For example, when the thermoplastic resin is polyamide and the continuous reinforcing fiber is glass fiber, the following treatment method can be mentioned. (a) Cut the above continuous fiber reinforced resin composite material into thin pieces. (b) Put 100 mg of the thin piece of the above continuous fiber reinforced resin composite material and 20 mL of hexafluoroisopropanol (HFIP) as a solvent into a mixing rotor and stir at 23 °C for 5 hours. (c) Remove the solvent by suction filtration, pour 40 mL of fresh HFIP over the filter to wash the composite material, and then air-dry it. (d) Put the composite material obtained in (c) and 20 mL of fresh HFIP into a mixing rotor and stir at 23 °C for 2 hours. (e) Remove the solvent by suction filtration, pour 40 mL of fresh HFIP over the filter to wash the composite material, and then dry it with nitrogen blowing at 23 °C. (f) Put the continuous reinforcing fiber obtained in (e) and 20 mL of fresh HFIP into a mixing rotor and stir at 23 °C for 2 hours. (g) Remove the solvent by suction filtration, pour 40 mL of fresh HFIP over the filter to wash the composite material, and then air-dry it. (h) Dry overnight in a vacuum dryer set at 23 °C. The interfacial coating rate is (Interface coverage rate) (%) = [N] / ([N] + [Si]) × 100 It can be determined as follows. Here, [N] is the relative elemental concentration of nitrogen determined by XPS measurement, and [Si] is the relative elemental concentration of silicon.

[0013] For example, when the thermoplastic resin is polyamide and the continuous reinforcing fiber is carbon fiber, using HFIP as a solvent, the sample is prepared in the same manner as when the thermoplastic resin is polyamide and the continuous reinforcing fiber is glass fiber. The interface coverage rate is, (Interface coverage rate) (%) = [N] / ([N] + [O]) × 100 It can be determined as follows. Here, [O] is the relative elemental concentration of oxygen determined by XPS measurement.

[0014] For example, when the thermoplastic resin is polypropylene and the continuous reinforcing fiber is glass fiber, the sample is prepared using xylene as a solvent. At this time, except that the temperature when stirring the composite material and the solvent is 90°C, the temperature when drying and the temperature of nitrogen blowing are 120°C, and the temperature of vacuum drying is 120°C, the sample is prepared in the same manner as when the thermoplastic resin is polyamide and the continuous reinforcing fiber is glass fiber. The interface coverage rate is, (Interface coverage rate) (%) = ([C] - [C0]) / ([C] - [C0] + [Si]) × 100 It can be determined as follows. [C] is the relative elemental concentration of carbon determined by XPS measurement. [C0] is the relative elemental concentration of carbon obtained when preparing the composite material and the sample in the same manner using continuously reinforced fibers without a sizing agent, etc., after removing the surface treatment agent such as the sizing agent from the continuously reinforced fibers by incineration, etc., and performing XPS measurement. In the case of the combination of polypropylene and glass fiber, the interface coverage rate is calculated using the relative elemental concentration of carbon after treatment with continuously reinforced fibers without a surface treatment agent because a carbon element is detected even when measuring a sample that is considered not to contain carbon in the XPS measurement.

[0015] When the thermoplastic resin is polyphenylene ether, regardless of the type of continuous reinforcing fiber, using chloroform as a solvent, samples can be prepared in the same manner as in the case where the thermoplastic resin is polyamide and the continuous reinforcing fiber is glass fiber, and the interfacial coating rate can be determined. Also, when the continuous reinforcing fiber is glass fiber, the calculation formula for the interfacial coating rate is (Interfacial coating rate) (%) = ([C] - [C0]) / ([C] - [C0] + [Si]) × 100 is as follows.

[0016] When the thermoplastic resin is polyvinyl alcohol, regardless of the type of continuous reinforcing fiber, samples can be prepared using water as a solvent. At this time, except that the temperature for stirring the composite material and the solvent is 95 °C, the drying temperature and the nitrogen blowing temperature are 120 °C, and the vacuum drying temperature is 120 °C, samples can be prepared in the same manner as in the case where the thermoplastic resin is polyamide and the continuous reinforcing fiber is glass fiber, and the interfacial coating rate can be determined. Also, when the continuous reinforcing fiber is glass fiber, the calculation formula for the interfacial coating rate is (Interfacial coating rate) (%) = ([C] - [C0]) / ([C] - [C0] + [Si]) × 100 is as follows.

[0017] When the thermoplastic resin is polyvinyl acetate, regardless of the type of continuous reinforcing fiber, using acetone as a solvent, samples can be prepared in the same manner as in the case where the thermoplastic resin is polyamide and the continuous reinforcing fiber is glass fiber, and the interfacial coating rate can be determined. Also, when the continuous reinforcing fiber is glass fiber, the calculation formula for the interfacial coating rate is (Interfacial coating rate) (%) = ([C] - [C0]) / ([C] - [C0] + [Si]) × 100 is as follows.

[0018] When the thermoplastic resin is polylactic acid, regardless of the type of continuous reinforcing fiber, using chloroform as a solvent, samples can be prepared in the same manner as in the case where the thermoplastic resin is polyamide and the continuous reinforcing fiber is glass fiber, and the interfacial coating rate can be determined. Also, when the continuous reinforcing fiber is glass fiber, the calculation formula for the interfacial coating rate is (Interface coverage rate) (%) = ([C] - [C0]) / ([C] - [C0] + [Si]) × 100 is as follows.

[0019] When the thermoplastic resin is polyvinyl chloride, regardless of the type of continuous reinforcing fiber, using acetone as a solvent, samples can be prepared in the same manner as in the case where the thermoplastic resin is polyamide and the continuous reinforcing fiber is glass fiber, and the interface coverage rate can be determined. Also, the calculation formula for the interface coverage rate is, when the continuous reinforcing fiber is glass fiber, (Interface coverage rate) (%) = ([C] - [C0]) / ([C] - [C0] + [Si]) × 100 is as follows.

[0020] The interface coverage rate change index can be obtained by dividing the interface coverage rate of the interfacial resin of the continuous fiber reinforced resin composite material (the interface coverage rate of the continuous fiber reinforced resin composite material without performing a fracture test) by the interface coverage rate of the continuous fiber reinforced resin composite material after the fracture test (for example, after performing the single - hand bending fatigue test described in the examples below). When the interface coverage rate change index is within the above range, high interface recovery characteristics are exhibited, and the variation in physical properties (such as strength) can be reduced. To adjust the above interface coverage rate change index to the above range, for example, the rate at which the thermoplastic resin impregnates the continuous reinforcing fiber is 0.8 - 1.2 times, preferably 0.85 - 1.15 times, more preferably 0.9 - 1.1 times the rate at which the thermoplastic resin impregnates the coupling continuous reinforcing fiber treated only with the coupling agent; a method of using a combination of continuous reinforcing fiber and thermoplastic resin such that the flexural strength of the coupling continuous fiber reinforced resin composite material composed of the coupling continuous reinforcing fiber treated only with the above coupling agent and the above thermoplastic resin is 0.6 times or more, preferably 0.6 - 1.2 times the flexural strength of the above continuous fiber reinforced resin composite material; a method of using a combination of glass fiber with a surface treatment agent added by the method described in the examples and PA66 manufactured by the method described in the examples can be mentioned. As combinations of continuous reinforcing fibers and a thermoplastic resin in which the bending strength is within the above range, combinations of a polyamide-based resin (preferably, polyamide 66, polyamide 6I, polyamide 6, polyamide 610, polyamide 410) and glass fibers or carbon fibers, and combinations of a polyolefin-based resin (preferably, polypropylene, modified polypropylene, polyethylene, modified polyethylene) and glass fibers or carbon fibers are preferable. If the impregnation rate and / or the bending strength are within the above ranges, the compatibility between the thermoplastic resin and a sizing agent (for example, a coupling agent in the sizing agent) on the surface of the continuous reinforcing fibers is improved. Here, the impregnation rate is obtained, for example, by laminating a continuous reinforcing fiber base material and a thermoplastic resin base material, performing hot press molding such that the maximum temperature of the continuous fiber reinforced resin composite material is the melting temperature of the thermoplastic resin + 15°C and the molding pressure is 5 MPa, then performing a cold press to room temperature with water cooling (water temperature 20°C) and a pressure of 5 MPa, cutting the obtained continuous reinforcing fiber composite material with a band saw or the like, polishing the cross section, and from an image obtained by SEM observation or the like, obtaining the occupied areas of each of the continuous reinforcing fiber bundle, the thermoplastic resin, and the voids, obtaining the ratio of the void area to the continuous reinforcing fiber bundle (total) area, and using the following formula: Impregnation rate (%) = {1 - (void area / continuous reinforcing fiber bundle area)} × 100 The impregnation rate (%) calculated by the above can be obtained by dividing by the time (minutes) during which the temperature of the thermoplastic resin during hot press molding and cold press is above the melting point for a thermoplastic resin having a melting point, and above the glass transition temperature for a resin not having a melting point. The bending strength of the continuous fiber reinforced resin composite material can be obtained, for example, by cutting out a strip-shaped test piece from the continuous fiber reinforced resin composite material and performing a three-point bending test in an environment of 23°C and 50% RH.

[0021] In the composite material of this embodiment, when the compatibility between the thermoplastic resin and the sizing agent (e.g., coupling agent) on the surface of the continuous reinforcing fiber is good, the sizing agent on the surface of the continuous reinforcing fiber and the thermoplastic resin around the sizing agent are bonded or adhered. Here, in the sample in which the thermoplastic resin is removed with a solvent by the above method, only the thermoplastic resin bonded or adhered to the sizing agent remains around the continuous reinforcing fiber, and the thermoplastic resin not bonded to the sizing agent is removed. That is, by using this sample, the ratio of the thermoplastic resin bonded or adhered to the sizing agent present on the surface of the continuous reinforcing fiber can be measured. When a fracture test is performed, due to the impact, the thermoplastic resin that is not bonded or adhered to the sizing agent and the thermoplastic resin with weak bonding or adhesion to the sizing agent present on the surface of the continuous reinforcing fiber fall off. When there are many thermoplastic resins firmly bonded or adhered to the sizing agent on the surface of the continuous reinforcing fiber, the thermoplastic resin is less likely to fall off by the fracture test, and the coating ratio of the thermoplastic resin on the continuous reinforcing fiber after the fracture test is less likely to decrease. And, a lot of thermoplastic resin remains on the surface of the continuous reinforcing fiber even after the fracture test, and the change in the interfacial coating rate of the continuous fiber reinforced resin composite material before and after the fracture test becomes small. In addition, in the above example, the example in which there is a sizing agent on the surface of the continuous reinforcing fiber is used for explanation, but even when the thermoplastic resin is directly bonded or adhered to the continuous reinforcing fiber without using a sizing agent, the evaluation can be performed in the same manner.

[0022] The change index of the exposed reinforcing fiber of the continuous fiber reinforced resin composite material of this embodiment represented by the following formula is preferably 0.8 to 1.2. (Change index of exposed reinforcing fiber) = (Exposed ratio of reinforcing fiber of continuous fiber reinforced resin composite material before fracture test) / (Exposed ratio of reinforcing fiber of composite material after fracture test) The above change index of the exposed reinforcing fiber is more preferably 0.85 to 1.15, and even more preferably 0.90 to 1.10. When the change index of the exposed reinforcing fiber is within the above range, higher interfacial recovery characteristics are exhibited, and the variation in physical properties can be made smaller. The reinforced fiber exposure change index can be obtained by dividing the exposure ratio of continuous reinforcing fibers after dissolution of the thermoplastic resin in a continuous fiber reinforced resin composite by the exposure ratio of continuous reinforcing fibers after dissolution of the thermoplastic resin in the continuous fiber reinforced resin composite after a fracture test (for example, after performing the single-handed bending fatigue test described in the examples below). The exposure ratio of continuous reinforcing fibers after dissolution of the thermoplastic resin can be obtained, for example, by dissolving the thermoplastic resin contained in the continuous fiber reinforced resin composite in a solvent by the above method, removing the solvent, washing the remaining continuous reinforcing fibers with the above fresh solvent, removing the thermoplastic resin other than the thermoplastic resin bonded to the continuous reinforcing fibers, drying, measuring by X-ray photoelectron spectroscopy (XPS), and dividing the relative elemental concentration of the elements derived from the obtained continuous reinforcing fibers by the relative elemental concentration of the elements derived from the continuous reinforcing fiber raw material not treated with a sizing agent. When the reinforcing fiber of the composite material is a glass fiber, for example, (Reinforcing fiber exposure ratio of composite material)=[Al] / [Al0] where [Al] is the relative elemental concentration of aluminum obtained by XPS measurement. [Al0] is the relative elemental concentration of aluminum obtained when continuous reinforcing fibers without a sizing agent such as a sizing agent are treated in the same manner and XPS measurement is performed. When the continuous reinforcing fiber is a carbon fiber, for example, (Reinforcing fiber exposure ratio of composite material)=[O] / [O0] where [O] is the relative elemental concentration of oxygen obtained by XPS measurement. [O0] is the relative elemental concentration of oxygen obtained when continuous reinforcing fibers without a surface treatment agent such as a sizing agent are treated in the same manner and XPS measurement is performed.

[0023] The reinforcing fiber exposure ratio is the ratio of the portion where the continuous reinforcing fibers are exposed after the above treatment on the surface of the continuous reinforcing fibers as the raw material. By having little change in the reinforcing fiber exposure ratio before and after the fracture test, a composite material with stable strength can be obtained even when vibrations, impacts, etc. occur.

[0024] The relative elemental change index of the interfacial nitrogen in the continuous fiber reinforced resin composite material of this embodiment is preferably 0.8 to 1.2, and more preferably 0.9 to 1.1. The relative elemental change index of the interfacial carbon in the continuous fiber reinforced resin composite material of this embodiment is preferably 0.8 to 1.2, and more preferably 0.9 to 1.1. The relative elemental change index of the interfacial aluminum in the continuous fiber reinforced resin composite material of this embodiment is preferably 0.8 to 1.2, and more preferably 0.9 to 1.1. The relative elemental change index of the interfacial silicon in the continuous fiber reinforced resin composite material of this embodiment is preferably 0.8 to 1.2, and more preferably 0.9 to 1.1. The relative elemental change index of the interfacial calcium in the continuous fiber reinforced resin composite material of this embodiment is preferably 0.8 to 1.2, and more preferably 0.9 to 1.1. The relative elemental change index of the interfacial oxygen in the continuous fiber reinforced resin composite material of this embodiment is preferably 0.8 to 1.2, and more preferably 0.9 to 1.1. When the relative elemental change index is within the above range, high interfacial recovery characteristics are exhibited, and the variation in physical properties can be reduced.

[0025] The relative elemental change index can be obtained by dividing the relative elemental concentration after dissolution of the thermoplastic resin in the continuous fiber reinforced resin composite material by the relative elemental concentration after resin dissolution in the continuous fiber reinforced resin composite material after a fracture test (for example, the one-handed bending fatigue test described in the examples below) is performed. The dissolution of the thermoplastic resin in the continuous fiber reinforced resin composite material can be carried out by the method described above. To adjust the relative element change index within the above range, for example, the impregnation rate of the thermoplastic resin into the continuous reinforcing fibers is set to be 0.8 to 1.2 times, preferably 0.85 to 1.15 times, more preferably 0.9 to 1.1 times the impregnation rate of the thermoplastic resin into the coupling continuous reinforcing fibers treated only with the coupling agent. Also, a method can be mentioned where the bending strength of the coupling continuous fiber reinforced resin composite material composed of the coupling continuous reinforcing fibers treated only with the above coupling agent and the above thermoplastic resin is 0.6 to 1.2 times the bending strength of the continuous fiber reinforced resin composite material, and a combination of continuous reinforcing fibers and thermoplastic resin is used.

[0026] [Form of continuous fiber reinforced resin composite material] The form of the continuous fiber reinforced resin composite material is not particularly limited, and the following various forms can be mentioned. For example, a form in which a woven or knitted fabric, braided cord, pipe-shaped object of continuous reinforcing fibers and a thermoplastic resin are combined, a form in which continuously aligned continuous reinforcing fibers in one direction and a thermoplastic resin are combined, a form in which yarns composed of continuous reinforcing fibers and a thermoplastic resin are aligned in one direction and shaped, a form in which yarns composed of continuous reinforcing fibers and a thermoplastic resin are made into a woven or knitted fabric, braided cord, or pipe shape and shaped, etc. The continuous fiber reinforced resin composite material of this embodiment may be a flat plate or may be a laminate including a layer of continuous reinforcing fibers and a layer of thermoplastic resin. For example, the length direction of the continuous reinforcing fibers may be arranged substantially parallel to the surface of the flat plate. Note that the layer of continuous reinforcing fibers is a layer containing continuous reinforcing fibers (for example, a continuous reinforcing fiber base material), and may be a layer in which a thermoplastic resin is impregnated inside the continuous reinforcing fibers. The form of the intermediate material before shaping of the continuous fiber reinforced resin composite material is not particularly limited, and examples include a mixed yarn of continuous reinforcing fibers and resin fibers, a coated yarn in which the periphery of a bundle of continuous reinforcing fibers is coated with resin, a tape-shaped material obtained by previously impregnating continuous reinforcing fibers with resin, a material in which continuous reinforcing fibers are sandwiched between resin films, a material in which resin powder is adhered to continuous reinforcing fibers, a material in which a bundle of continuous reinforcing fibers is used as a core material and the periphery is made into a braided cord with resin fibers, a material in which resin is previously impregnated between reinforcing fibers, a form in which continuous reinforcing fibers are brought into contact with molten resin, etc.

[0027] [Method for manufacturing continuous fiber reinforced resin composite material] The method for manufacturing the continuous fiber reinforced resin composite material of the present embodiment is not particularly limited, and the following various methods can be mentioned.

[0028] In one method, for example, a base material (for example, a base material made of continuous reinforcing fibers, a base material made of a thermoplastic resin) constituting the continuous fiber reinforced resin composite material is cut or shaped according to the desired composite material, stacked in the required number or laminated in the required number considering the thickness of the target product, and set in a mold according to the mold shape.

[0029] The base material may be cut one by one, or may be cut after stacking the desired number. From the viewpoint of productivity, it is preferable to cut in a stacked state. The cutting method may be any method, and examples include a water jet, a blade press machine, a hot blade press machine, a laser, a plotter, etc. Among them, a hot blade press machine is preferable because it has excellent cross-sectional shape and further improves handleability by welding the end faces when cutting a plurality of stacked materials. The appropriate cutting shape can be adjusted by repeating trial and error, but it is preferably set by performing a simulation by CAE (computer aided engineering) according to the shape of the mold.

[0030] The shaping of the base material may be performed by any method, and for example, it may be shaped into a sheet shape.

[0031] After setting the base material in the mold, the mold is closed and compressed. Then, the mold is temperature-controlled to a temperature equal to or higher than the melting point of the thermoplastic resin constituting the continuous fiber reinforced resin composite material to melt and shape the thermoplastic resin. There is no particular regulation on the clamping pressure, but it is preferably 1 MPa or more, more preferably 3 MPa or more. Also, in order to vent gas, etc., the mold may be clamped once, and after compression molding, the clamping pressure of the mold may be released once. From the viewpoint of strength development, the compression molding time is preferably long within the range where the thermoplastic resin used does not undergo thermal degradation, but from the viewpoint of productivity, it is preferably within 2 minutes, more preferably within 1 minute.

[0032] The continuous fiber reinforced resin composite material may further be injection filled with a thermoplastic resin composition for hybrid to form a hybrid composite material. In the manufacturing process of the hybrid composite material, the above base material is set in a mold, the mold is closed and pressurized, and after a predetermined time, a predetermined thermoplastic resin composition for hybrid is further injection filled and molded, and the thermoplastic resin of the base material and the predetermined thermoplastic resin composition for hybrid are joined together to manufacture a hybrid composite material.

[0033] The timing of injection filling the predetermined thermoplastic resin composition for hybrid greatly affects the interfacial strength between the two thermoplastic resins. The timing of injection filling the predetermined thermoplastic resin composition for hybrid is preferably within 30 seconds after the mold temperature rises to the melting point or above the glass transition temperature of the thermoplastic resin constituting the base material after setting the base material in the mold and closing the mold. The mold temperature when injecting the predetermined thermoplastic resin composition for hybrid is preferably at or above the melting point or above the glass transition temperature of the thermoplastic resin constituting the base material that joins with the thermoplastic resin composition for hybrid. More preferably, it is at or above the melting point + 10°C or above the glass transition temperature + 10°C of the thermoplastic resin constituting the base material that joins with the thermoplastic resin composition for hybrid, still more preferably at or above the melting point + 20°C or above the glass transition temperature + 20°C, and even more preferably at or above the melting point + 30°C or above the glass transition temperature + 30°C.

[0034] In the hybrid composite material, the joint portion between the thermoplastic resin constituting the base material and the thermoplastic resin composition for hybrid formed by injection molding preferably has an uneven structure in which they are mixed with each other. Setting the mold temperature to be at or above the melting point of the thermoplastic resin composition for hybrid to be injected and keeping the resin pressure high during injection molding, for example, 1 MPa or more, is effective in increasing the interfacial strength. To increase the interfacial strength, it is preferable to set the above-mentioned holding pressure to 5 MPa or more, and more preferably 10 MPa or more. Also, it is preferable from the viewpoint of enhancing the interfacial strength to make the pressure holding time long, for example, 5 seconds or more, preferably 10 seconds or more, and more preferably to hold the time until the mold temperature becomes equal to or lower than the melting point of the thermoplastic resin composition.

[0035] In the method for manufacturing the composite material of the present embodiment described above, the impregnation rate of the thermoplastic resin into the continuous reinforcing fiber is preferably 0.8 to 1.2 times the impregnation rate of the thermoplastic resin into the coupling continuous reinforcing fiber treated only with the coupling agent. Here, the coupling continuous reinforcing fiber refers to a continuous reinforcing fiber manufactured in the same manner as the continuous reinforcing fiber, except that the sizing agent is changed to only the coupling agent. In the continuous reinforcing fiber, it is preferable to use a sizing agent containing a coupling agent and a lubricant and / or a binder, and in the coupling continuous reinforcing fiber, it is preferable to use the coupling agent. In the method for manufacturing the composite material of the present embodiment described above, the flexural strength of the coupling continuous fiber reinforced resin composite material composed of the coupling continuous reinforcing fiber and the thermoplastic resin is preferably 0.6 times or more the flexural strength of the continuous fiber reinforced resin composite material. Here, the coupling continuous fiber reinforced resin composite material refers to a composite material manufactured in the same manner as the continuous fiber reinforced resin composite material, except that the coupling continuous reinforcing fiber is used as the continuous reinforcing fiber. In the continuous reinforcing fiber, it is preferable to use a sizing agent containing a coupling agent and a lubricant and / or a binder, and in the coupling continuous reinforcing fiber, it is preferable to use the coupling agent.

[0036] (Thermoplastic resin composition for hybrid) The thermoplastic resin composition for hybrid for injection molding used for manufacturing a hybrid composite material is not particularly limited as long as it is a thermoplastic resin composition used for general injection molding. The thermoplastic resin contained in the thermoplastic resin composition for hybrid is not limited to the following, but examples include a mixture of one or more thermoplastic resins such as polyethylene, polypropylene, polyvinyl chloride, acrylic resin, styrene resin, polyethylene terephthalate, polybutylene terephthalate, polyarylate, polyphenylene ether, modified polyphenylene ether resin, wholly aromatic polyester, polyacetal, polycarbonate, polyetherimide, polyethersulfone, polyamide resin, polysulfone, polyetheretherketone, polyetherketone, etc.

[0037] Various fillers may be blended in the thermoplastic resin composition for hybrid. The thermoplastic resin composition for hybrid may be a black resin composition containing a colorant. Examples of the various fillers include short fibers and long fiber materials which are discontinuous reinforcing materials of the same kind of material as the above continuous reinforcing fibers. When using short glass fibers and long fibers as the discontinuous reinforcing material, the same sizing agent as that applied to the continuous reinforcing fibers constituting the continuous fiber reinforced resin composite material of the present embodiment may be used. The sizing agent (sizing agent) preferably consists of at least one selected from the group consisting of a coupling agent (preferably a silane coupling agent), a lubricant, and a binder. Regarding the types of the silane coupling agent, the lubricant, and the binder, the same ones as those of the sizing agent for the continuous reinforcing fibers can be used.

[0038] From the viewpoint of the interfacial strength with the thermoplastic resin to be joined, the thermoplastic resin contained in the thermoplastic resin composition for hybrid used for injection molding is preferably similar to the thermoplastic resin on the joining surface constituting the continuous fiber reinforced resin composite material, and more preferably of the same kind. Specifically, when using polyamide 66 for the thermoplastic resin on the joining surface, the resin material of the thermoplastic resin composition for hybrid for injection molding is preferably polyamide 66.

[0039] As other methods, there are a molding method in which a base material is placed in a mold and compressed by a double-belt press machine, a method in which a mold frame is installed so as to surround the four sides of the installed base material and pressurized and molded by a double-belt press machine, a compression molding machine set at one or more temperatures for heating, and a compression molding machine set at one or more temperatures for cooling. Examples include a molding method in which a mold with a base material installed is sequentially put into the compression molding machine for molding, a continuous compression molding machine, and the like.

[0040] (Continuous reinforcing fiber) As the continuous reinforcing fiber, those used in ordinary continuous fiber reinforced resin composite materials may be used. The continuous reinforcing fiber is not limited to the following, and examples include glass fiber, carbon fiber, plant fiber, aramid fiber, ultra-high strength polyethylene fiber, polybenzazole-based fiber, liquid crystal polyester fiber, polyketone fiber, metal fiber, ceramic fiber, and the like. From the viewpoints of mechanical properties, thermal properties, and versatility, glass fiber, carbon fiber, plant fiber, and aramid fiber are preferable, and from the viewpoint of productivity, glass fiber is preferable. The above continuous reinforcing fiber may be used alone or in combination of two or more.

[0041] -Sizing agent- It is preferable that the above continuous reinforcing fiber has a sizing agent attached thereto. When glass fiber is selected as the continuous reinforcing fiber, a sizing agent may be used. The sizing agent may contain one or more selected from the group consisting of a coupling agent, a lubricant, and a binder, preferably contains at least a binder or a coupling agent, and more preferably consists of only one or more selected from the group consisting of a coupling agent, a lubricant, and a binder. The coupling agent is a compound that binds materials with different properties, mainly inorganic materials and organic materials. The coupling agent is not limited to the following, and examples include silane coupling agents, polymer coupling agents, polymerizable coupling agents, etc. From the viewpoint of the compatibility between the thermoplastic resin and the continuous reinforcing fiber, a silane coupling agent is preferable. Further, the sizing agent may consist of a coupling agent (preferably a silane coupling agent) and a binder, or may consist of a coupling agent (preferably a silane coupling agent), a lubricant, and a binder. By being a sizing agent that creates a strong bond between continuous reinforcing fibers (preferably glass fibers) and the resin coating around them, a continuous fiber reinforced resin composite material with low porosity can be obtained. The sizing agent may be externally added to the materials used, or may be internally contained in the materials used. For example, the lubricant may be included in commercially available products of the thermoplastic resin used.

[0042] --Silane coupling agent-- Silane coupling agents are usually used as surface treatment agents for glass fibers and carbon fibers, and contribute to improving the interfacial adhesion strength. Examples of silane coupling agents include, but are not limited to, aminosilanes such as γ-aminopropyltrimethoxysilane and N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane; mercaptosilanes such as γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane; epoxysilanes; vinylsilanes; maleic acids, etc. When using polyamide as the thermoplastic resin, it is preferable to select one that easily binds to the carboxyl group or amino group, which are the end groups of the polyamide-based resin, and aminosilanes are preferred.

[0043] --Lubricant-- The lubricant contributes to improving the fibrillability of continuous reinforcing fibers (preferably glass fibers). As the lubricant, any ordinary liquid or solid lubricating material according to the purpose can be used as long as it does not inhibit the coupling agent and the binder. Examples include, but are not limited to, waxes of animal and plant or mineral origin such as carnauba wax and lanolin wax; surfactants such as fatty acid amides, fatty acid esters, fatty acid ethers, aromatic esters, and aromatic ethers.

[0044] --Sizing agent-- The sizing agent contributes to improving the bundling property and the interfacial adhesion strength of continuous reinforcing fibers (preferably glass fibers). As the sizing agent, polymers according to the purpose, and thermoplastic resins other than the above-mentioned thermoplastic resin as the main material of the continuous fiber reinforced resin composite material can be used. The polymer as the sizing agent is not limited to the following, but for example, homopolymers of acrylic acid, copolymers of acrylic acid and other copolymerizable monomers, copolymers of methacrylic acid esters and copolymerizable monomers, and salts thereof with primary, secondary, and tertiary amines, etc. can be mentioned. Also, for example, polyurethane resins synthesized from isocyanates such as m-xylylene diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), and isophorone diisocyanate, and polyester-based or polyether-based diols are also preferably used. The homopolymer of acrylic acid preferably has a weight average molecular weight of 1,000 to 90,000, more preferably 1,000 to 25,000. The copolymerizable monomers constituting the copolymer of acrylic acid and other copolymerizable monomers are not limited to the following, but for example, among the monomers having a hydroxyl group and / or a carboxyl group, one or more selected from the group consisting of acrylic acid, maleic acid, methacrylic acid, vinyl acetic acid, crotonic acid, isocrotonic acid, fumaric acid, itaconic acid, citraconic acid, and mesaconic acid can be mentioned (however, the case of only acrylic acid is excluded). It is preferable to have one or more ester-based monomers as the copolymerizable monomer. As the copolymer of a methacrylic acid ester and a copolymerizable monomer, it is preferably a copolymerizable monomer of methyl methacrylate or ethyl methacrylate (preferably methyl methacrylate) and one or more copolymerizable monomers selected from the group consisting of acrylic acid, maleic acid, maleic anhydride, methacrylic acid, vinyl acetic acid, crotonic acid, isocrotonic acid, fumaric acid, itaconic acid, citraconic acid, trimellitic anhydride, pyromellitic dianhydride, and mesaconic acid (preferably maleic anhydride). For example, it may be a copolymer of one methacrylic acid ester and one copolymerizable monomer. The mass ratio of the structural unit derived from the methacrylic acid ester to 100% by mass of the copolymer of the methacrylic acid ester and the copolymerizable monomer is preferably 30 to 98% by mass, more preferably 60 to 95% by mass. The mass ratio of the structural unit derived from the copolymerizable monomer to 100% by mass of the copolymer of the methacrylic acid ester and the copolymerizable monomer is preferably 2 to 70% by mass, more preferably 5 to 40% by mass. The weight average molecular weight of the copolymer of the methacrylic acid ester and the copolymerizable monomer is preferably 1,000 to 90,000, more preferably 1,000 to 25,000. The salts of the homopolymers and copolymers of acrylic acid with primary, secondary, and tertiary amines are not limited to the following, and examples include triethylamine salts, triethanolamine salts, glycine salts, and the like. From the viewpoints of improving the stability of the mixed solution with other co-used agents (such as silane coupling agents) and reducing the amine odor, the degree of neutralization is preferably 20 to 90%, more preferably 40 to 60%. The weight average molecular weight of the polymer of acrylic acid forming the salt is not particularly limited, but a range of 3,000 to 50,000 is preferable. From the viewpoint of improving the bundling property of the continuous reinforcing fibers, 3,000 or more is preferable, and from the viewpoint of improving the properties when forming a composite body, 50,000 or less is preferable. When using polyamide as the thermoplastic resin, it is preferable to use a resin that has good wettability with the polyamide resin or a resin with a similar surface tension as the binder. Specifically, for example, an emulsion of a polyurethane resin, an emulsion of a polyamide resin, or a modified product thereof can be selected.

[0045] The thermoplastic resins used as binders are not limited to the following, but examples include polyolefin resins, polyamide resins, polyurethane resins, polyacetal resins, polycarbonate resins, polyester resins, polyether ketone, polyether ether ketone, polyether sulfone, polyphenylene sulfide, thermoplastic polyetherimide, thermoplastic fluorine-based resins, and modified thermoplastic resins obtained by modifying these. It is preferable that the thermoplastic resin used as the binder is the same type of thermoplastic resin and / or modified thermoplastic resin as the resin that coats the continuous reinforcing fiber, as this improves the adhesion between the glass fiber and the thermoplastic resin after forming a composite material.

[0046] Furthermore, when further improving the adhesion between the continuous reinforcing fiber and the thermoplastic resin coating it, and attaching the sizing agent as an aqueous dispersion to the continuous reinforcing fiber (e.g., glass fiber), from the perspective of reducing the ratio of the emulsifier component or making the emulsifier unnecessary, a modified thermoplastic resin is preferable as the thermoplastic resin used as the binder. Here, the modified thermoplastic resin means a resin obtained by copolymerizing different monomer components for the purpose of changing the properties of the thermoplastic resin in addition to the monomer components that can form the main chain of the thermoplastic resin, and modifying the hydrophilicity, crystallinity, thermodynamic properties, etc. The modified thermoplastic resins used as binders are not limited to the following, but examples include modified polyolefin resins, modified polyamide resins, modified polyester resins, etc.

[0047] The modified polyolefin resin as a finishing agent is a copolymer of an olefin monomer such as ethylene or propylene and a monomer copolymerizable with an unsaturated carboxylic acid and / or its ester form, etc., or a homopolymer of a monomer copolymerizable with an olefin monomer such as an unsaturated carboxylic acid and / or its ester form, etc., and can be produced by a known method. It may be a random copolymer obtained by copolymerizing an olefin monomer with an unsaturated carboxylic acid and / or its ester form, or a graft copolymer obtained by grafting an unsaturated carboxylic acid onto an olefin. Examples of the olefin monomer include, but are not limited to, ethylene, propylene, 1-butene, etc. These may be used alone or in combination of two or more. Examples of the monomer copolymerizable with the olefin monomer include unsaturated carboxylic acids such as acrylic acid, maleic acid, maleic anhydride, methacrylic acid, vinyl acetic acid, crotonic acid, isocrotonic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, and esterified products of these unsaturated carboxylic acids (methyl ester, ethyl ester, etc.). These may be used alone or in combination of two or more. When the modified polyolefin resin is a copolymer of an olefin monomer and a monomer copolymerizable with the olefin monomer, the monomer ratio is preferably 60 to 95% by mass of the olefin monomer and 5 to 40% by mass of the monomer copolymerizable with the olefin monomer, with the total mass of the copolymer being 100% by mass. More preferably, it is 70 to 85% by mass of the olefin monomer and 15 to 30% by mass of the monomer copolymerizable with the olefin monomer. If the olefin monomer is 60% by mass or more, the affinity with the matrix is good. If the mass% of the olefin monomer is 95% by mass or less, the water dispersibility of the modified polyolefin resin is good, and it is easy to uniformly apply it to the continuous reinforcing fiber.

[0048] The modified polyolefin resin used as a binder may have modified groups such as carboxyl groups introduced by copolymerization neutralized with a basic compound. Examples of the basic compound include, but are not limited to, alkalis such as sodium hydroxide and potassium hydroxide; ammonia; and amines such as monoethanolamine and diethanolamine. The weight average molecular weight of the modified polyolefin resin used as a binder is not particularly limited, but is preferably 5,000 to 200,000, and more preferably 50,000 to 150,000. From the viewpoint of improving the bundling property of glass fibers, 5,000 or more is preferable, and from the viewpoint of emulsion stability in the case of water dispersibility, 200,000 or less is preferable.

[0049] The modified polyamide resin used as a binder is a modified polyamide compound having a hydrophilic group such as a polyalkylene oxide chain or a tertiary amine component introduced into the molecular chain, and can be produced by a known method. When introducing a polyalkylene oxide chain into the molecular chain, for example, it is produced by copolymerizing a modified product of part or all of polyethylene glycol, polypropylene glycol, etc. with diamine or dicarboxylic acid. When introducing a tertiary amine component, for example, it is produced by copolymerizing aminoethylpiperazine, bisaminopropylpiperazine, α-dimethylamino ε-caprolactam, etc.

[0050] The modified polyester resin used as a binder is a copolymer of polycarboxylic acid or its anhydride and polyol, and is a resin having a hydrophilic group in the molecular skeleton including the terminal, and can be produced by a known method. Examples of the hydrophilic group include polyalkylene oxide group, sulfonate, carboxyl group, and neutralized salts thereof. Examples of the polycarboxylic acid or its anhydride include aromatic dicarboxylic acid, sulfonate-containing aromatic dicarboxylic acid, aliphatic dicarboxylic acid, alicyclic dicarboxylic acid, and polycarboxylic acid having three or more functional groups. Examples of the aromatic dicarboxylic acid include, but are not limited to, phthalic acid, terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, phthalic anhydride, and the like. Examples of the sulfonate group-containing aromatic dicarboxylic acid include, but are not limited to, sulfoterephthalate, 5-sulfoisophthalate, 5-sulfoorthophthalate, and the like. Examples of the aliphatic dicarboxylic acid or alicyclic dicarboxylic acid include, but are not limited to, fumaric acid, maleic acid, itaconic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, 1,4-cyclohexanedicarboxylic acid, succinic anhydride, maleic anhydride, and the like. Examples of the polycarboxylic acid having three or more functional groups include, but are not limited to, trimellitic acid, pyromellitic acid, trimellitic anhydride, pyromellitic anhydride, and the like. From the viewpoint of improving the heat resistance of the modified polyester resin, 40 to 99 mol% of the total polycarboxylic acid component is preferably an aromatic dicarboxylic acid. Further, from the viewpoint of the emulsion stability when the modified polyester resin is made into an aqueous dispersion, 1 to 10 mol% of the total polycarboxylic acid component is preferably a sulfonate group-containing aromatic dicarboxylic acid.

[0051] Examples of the polyol constituting the modified polyester resin include diol, polyol having three or more functional groups, and the like. Examples of the diol include, but are not limited to, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, polybutylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, polytetramethylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, bisphenol A or its alkylene oxide adduct, and the like. Examples of the polyol having three or more functional groups include trimethylolpropane, glycerin, pentaerythritol, and the like.

[0052] As the copolymerization ratio of the polycarboxylic acid or its anhydride and the polyol that constitute the modified polyester resin, with the total mass of the copolymerization components being 100% by mass, it is preferably 40 to 60% by mass of the polycarboxylic acid or its anhydride and 40 to 60% by mass of the polyol, and more preferably 45 to 55% by mass of the polycarboxylic acid or its anhydride and 45 to 55% by mass of the polyol. As the weight average molecular weight of the modified polyester resin, 3,000 to 100,000 is preferable, and 10,000 to 30,000 is more preferable. From the viewpoint of improving the bundling property of continuous reinforcing fibers (for example, glass fibers), 3,000 or more is preferable, and from the viewpoint of emulsion stability when making it water-dispersible, 100,000 or less is preferable.

[0053] As the polymer and thermoplastic resin used as the binder, only one kind may be used alone, or two or more kinds may be used in combination. With the total amount of the binder being 100% by mass, it is preferable to use 50% by mass or more of one or more polymers selected from homopolymers of acrylic acid, copolymers of acrylic acid and other copolymerizable monomers, and salts thereof with primary, secondary, and tertiary amines, and more preferably 60% by mass or more.

[0054] When the bundling agent consists of a coupling agent (for example, a silane coupling agent) and a binder, the total adhesion mass of the coupling agent and the binder with respect to 100% by mass of the continuous reinforcing fiber (for example, glass fiber) is preferably 0.1 to 3% by mass, more preferably 0.15 to 2% by mass, and even more preferably 0.2 to 1% by mass. From the viewpoints of controlling the bundling property of the continuous reinforcing fiber (for example, glass fiber) and improving the interfacial adhesion strength, the adhesion amount of the bundling agent is preferably 0.1% by mass or more as the total mass of the coupling agent and the binder with respect to 100% by mass of the continuous reinforcing fiber (for example, glass fiber), and preferably 3% by mass or less from the viewpoint of the handleability of the yarn. In addition, when the sizing agent consists of a coupling agent (preferably a silane coupling agent), a lubricant, and a binder, the total adhered mass of the coupling agent, lubricant, and binder with respect to 100% by mass of the continuous reinforcing fibers (e.g., glass fibers) is preferably 0.1 to 3% by mass, more preferably 0.2 to 2% by mass, and still more preferably 0.2 to 1% by mass. From the viewpoints of controlling the bundling property of the continuous reinforcing fibers (e.g., glass fibers) and improving the interfacial adhesion strength, the adhesion amount of the sizing agent is preferably 0.1% by mass or more as the total mass of the coupling agent, lubricant, and binder with respect to 100% by mass of the continuous reinforcing fibers, and preferably 3% by mass or less from the viewpoint of the handleability of the yarn. In addition, the adhesion mass of the coupling agent with respect to 100% by mass of the continuous reinforcing fibers is preferably 0.05 to 1% by mass, more preferably 0.1 to 0.9% by mass.

[0055] --Composition of sizing agent for glass fibers-- The blending amount of the coupling agent in the sizing agent for glass fibers is preferably 0.1 to 2% by mass, more preferably 0.1 to 1% by mass, and still more preferably 0.2 to 0.5% by mass from the viewpoints of improving the bundling property of glass fibers, improving the interfacial adhesion strength, and improving the mechanical strength of the composite molded body. The blending amount of the lubricant in the sizing agent for glass fibers is preferably 0.01% by mass or more, more preferably 0.02% by mass or more from the viewpoint of providing sufficient lubricity, and preferably 1.5% by mass or less, more preferably 1% by mass or less, and still more preferably 0.5% by mass or less from the viewpoints of improving the interfacial adhesion strength and improving the mechanical strength of the composite molded body. The blending amount of the binder in the sizing agent for glass fibers is preferably 1 to 25% by mass, more preferably 3 to 15% by mass, and still more preferably 3 to 10% by mass from the viewpoints of controlling the bundling property of glass fibers, improving the interfacial adhesion strength, and improving the mechanical strength of the composite molded body.

[0056] When glass fiber is used as the continuous reinforcing fiber and the sizing agent consists of a silane coupling agent, a lubricant, and a binder, in the sizing agent for the glass fiber, it is preferable to contain 0.1 to 2% by mass of the silane coupling agent, 0.01 to 1.5% by mass of the lubricant, and 1 to 25% by mass of the binder, respectively. It is preferable to dilute these components with water and adjust the total mass to 100% by mass.

[0057] --Mode of use of sizing agent for glass fiber-- The sizing agent for glass fiber may be adjusted to any form according to the mode of use, such as an aqueous solution, a colloidal dispersion form, an emulsion form using an emulsifier, etc. However, from the viewpoints of improving the dispersion stability and heat resistance of the sizing agent, it is preferable to use it in the form of an aqueous solution. The glass fiber as the continuous reinforcing fiber constituting the continuous fiber reinforced resin composite material of the present embodiment is obtained continuously by applying the above-described sizing agent to the glass fiber using a known method such as a roller-type applicator in a known manufacturing process of glass fiber and drying the produced glass fiber. In addition, as the mode of use of the sizing agent for glass fiber, there are also methods such as immersing the glass fiber in a liquid containing the sizing agent and immersing a glass fiber substrate in a liquid containing the sizing agent.

[0058] Similarly, when carbon fiber is selected as the continuous reinforcing fiber, a sizing agent may also be used, and the sizing agent preferably consists of a coupling agent, a lubricant, and a binder. As the coupling agent, one having good compatibility with the hydroxyl groups present on the surface of the carbon fiber is selected. As the binder, one having good wettability with the selected thermoplastic resin or having a surface tension close thereto is selected. As the lubricant, one that does not inhibit the coupling agent and the binder can be selected. Regarding the type of sizing agent used for carbon fiber, known ones can be used. Specifically, for example, those described in JP-A-2015-101794 can be used.

[0059] When using other continuous reinforcing fibers, according to the properties of the continuous reinforcing fibers, the type and application amount of the sizing agent that can be used for glass fibers and carbon fibers can be appropriately selected. It is preferable to use the type and application amount of the sizing agent according to that for carbon fibers.

[0060] (Shape of continuous reinforcing fiber) The continuous reinforcing fiber is a multifilament composed of a plurality of filaments, and the number of filaments per single yarn is preferably 30 to 15,000 from the viewpoint of handleability. The single filament diameter R of the continuous reinforcing fiber is preferably 2 to 30 μm, more preferably 4 to 25 μm, still more preferably 6 to 20 μm, and most preferably 8 to 18 μm from the viewpoints of strength and handleability. The product RD of the single filament diameter R (μm) and the density D (g / cm 3 ) of the continuous reinforcing fiber is preferably 5 to 100 μm·g / cm 3 , more preferably 10 to 50 μm·g / cm 3 , still more preferably 15 to 45 μm·g / cm 3 , even more preferably 20 to 45 μm·g / cm 3 from the viewpoints of the handleability of the continuous reinforcing fiber and the strength of the composite material.

[0061] The density D can be measured by a hydrometer. On the other hand, the single filament diameter R (μm) can be calculated from the density D (g / cm 3 ) and the fineness (dtex) and the number of filaments per single yarn (pieces) by the following formula:

Equation

[0062] To make the product RD of the continuous reinforcing fiber within a predetermined range, for commercially available continuous reinforcing fibers, the fineness (dtex) and the number of filaments per single yarn (pieces) can be appropriately selected according to the density of the continuous reinforcing fiber. For example, when using glass fiber as the continuous reinforcing fiber, if the density is about 2.5 g / cm3 Therefore, those with a single fiber diameter of 2 to 40 μm can be selected. Specifically, when the single fiber diameter of the glass fiber is 9 μm, by selecting glass fiber with a fineness of 660 dtex and 400 single fibers, the product RD becomes 23. Also, when the single fiber diameter of the glass fiber is 17 μm, by selecting glass fiber with a fineness of 11,500 dtex and 2,000 single fibers, the product RD becomes 43. When using carbon fiber as the continuous reinforcing fiber, the density is about 1.8 g / cm 3 Therefore, those with a single fiber diameter of 2.8 to 55 μm can be selected. Specifically, when the single fiber diameter of the carbon fiber is 7 μm, by selecting carbon fiber with a fineness of 2,000 dtex and 3,000 single fibers, the product RD becomes 13. When using aramid fiber as the continuous reinforcing fiber, the density is about 1.45 g / cm 3 Therefore, those with a single fiber diameter of 3.4 to 68 μm can be selected. Specifically, when the single fiber diameter of the aramid fiber is 12 μm, by selecting aramid fiber with a fineness of 1,670 dtex and 1,000 single fibers, the product RD becomes 17.

[0063] Continuous reinforcing fibers, for example, glass fibers, are produced by weighing and mixing raw materials of glass, melting them into molten glass in a melting furnace, spinning them into glass filaments, applying a sizing agent, and passing through a spinning machine to form a winding form such as direct wind roving (DWR), cake, or twisted yarn. The continuous reinforcing fiber can be in any form, but it is preferable to wind it into yarn, cake, or DWR because it improves productivity and production stability in the process of coating with resin. From the perspective of productivity, DWR is most preferable.

[0064] The form of the continuous reinforcing fiber is not particularly limited, and various forms such as woven fabric, knitted fabric, braided cord, pipe-shaped, non-crimp fabric, unidirectional material, etc. can be mentioned. Preferably, it is in the form of woven fabric, non-crimp fabric, or unidirectional material.

[0065] (Thermoplastic resin) The thermoplastic resin is not limited to the following, and examples include polyolefin resins such as polyethylene and polypropylene; polyamide resins such as polyamide 6, polyamide 66, polyamide 46, polyamide 612, polyamide 6I, polyamide 6T, polyamide 6I / 6T, polyamide MXD6, polyamide 11, polyamide 12, polyamide 610, and polyamide 1010; polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polytrimethylene terephthalate; polyacetal resins such as polyoxymethylene; polycarbonate resins; polyether resins such as polyether ketone, polyether ether ketone, polyether glycol, polypropylene glycol, and polytetramethylene ether glycol; polyether sulfone; polyphenylene sulfide; thermoplastic polyether imide; thermoplastic fluorine resins such as tetrafluoroethylene-ethylene copolymer; polyurethane resins; acrylic resins; polyphenylene ether; and modified thermoplastic resins obtained by modifying these.

[0066] Among these thermoplastic resins, polyolefin resins, polyamide resins, polyester resins, polyether resins, polyether sulfone, polyphenylene sulfide, thermoplastic polyether imide, thermoplastic fluorine resins, and polyphenylene ether are preferred. From the viewpoints of mechanical properties and versatility, polyolefin resins, modified polyolefin resins, polyamide resins, polyester resins, polyurethane resins, polyphenylene ether, and acrylic resins are more preferred. Considering the viewpoint of thermal properties, polyamide resins, polyphenylene ether, and polyester resins are even more preferred. Further, from the viewpoint of durability against repeated load, polyamide resins are even more preferred.

[0067] - Polyester resin - The polyester resin means a polymer compound having a -CO-O- (ester) bond in the main chain. Examples of the polyester resin include, but are not limited to, polyethylene terephthalate, polybutylene terephthalate, polytetramethylene terephthalate, poly-1,4-cyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalene dicarboxylate, and the like. The polyester resin may be a homopolyester or a copolyester. In the case of a copolyester, it is preferably a copolymer obtained by appropriately copolymerizing a third component with a homopolyester. Examples of the third component include, but are not limited to, diol components such as diethylene glycol, neopentyl glycol, and polyalkylene glycol, and dicarboxylic acid components such as adipic acid, sebacic acid, phthalic acid, isophthalic acid, and 5-sodium sulfoisophthalic acid. Moreover, a polyester resin using a raw material derived from biomass resources can also be used. Examples include, but are not limited to, aliphatic polyester resins such as polylactic acid, polybutylene succinate, and polybutylene succinate adipate, and aromatic polyester resins such as polybutylene adipate terephthalate.

[0068] - Polyamide resin - The polyamide resin means a polymer compound having a -CO-NH- (amide) bond in the main chain. Examples include aliphatic polyamides, aromatic polyamides, and wholly aromatic polyamides.

[0069] Examples of the polyamide resin include, but are not limited to, polyamides obtained by ring-opening polymerization of lactams, polyamides obtained by self-condensation of ω-aminocarboxylic acids, polyamides obtained by condensing diamines and dicarboxylic acids, and copolymers thereof. The polyamide resin may be used alone or as a mixture of two or more. Examples of the lactam include, but are not limited to, pyrrolidone, caprolactam, undecanolactam, and dodecanolactam. Examples of ω - aminocarboxylic acids include, but are not limited to, ω - amino fatty acids which are ring - opening compounds of lactams with water. Lactams or ω - aminocarboxylic acids may be condensed by using two or more kinds of monomers in combination respectively. Examples of diamines (monomers) include, but are not limited to, linear aliphatic diamines such as hexamethylenediamine and pentamethylenediamine; branched aliphatic diamines such as 2 - methylpentanediamine and 2 - ethylhexamethylenediamine; aromatic diamines such as p - phenylenediamine and m - phenylenediamine; and alicyclic diamines such as cyclohexanediamine, cyclopentanediamine and cyclooctanediamine. Examples of dicarboxylic acids (monomers) include, but are not limited to, aliphatic dicarboxylic acids such as adipic acid, pimelic acid and sebacic acid; aromatic dicarboxylic acids such as phthalic acid and isophthalic acid; and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. The diamine and dicarboxylic acid as monomers may be condensed either alone or in combination of two or more kinds.

[0070] Examples of polyamide - based resins include, but are not limited to, aliphatic polyamides such as polyamide 4 (poly α - pyrrolidone), polyamide 6 (polycaproamide), polyamide 11 (polyundecanamide), polyamide 12 (polydodecanamide), polyamide 46 (polytetramethylene adipamide), polyamide 66 (polyhexamethylene adipamide), polyamide 610, polyamide 612, polyamide 1010; semi - aromatic polyamides such as polyamide 6T (polyhexamethylene terephthalamide), polyamide 9T (polynonamethylene terephthalamide), polyamide 6I (polyhexamethylene isophthalamide), polyamide MXD6, polyamide 6I / 6T; and copolymer polyamides containing these as constituent components. Examples of the copolyamide include, but are not limited to, copolymers of hexamethylene adipamide and hexamethylene terephthalamide, copolymers of hexamethylene adipamide and hexamethylene isophthalamide, and copolymers of hexamethylene terephthalamide and 2-methylpentanediamine terephthalamide.

[0071] [Additive] The continuous fiber reinforced resin composite material of the present embodiment may contain an additive as necessary. Examples of the composite material of the present embodiment include colorants, anti-aging agents, antioxidants, weathering agents, metal deactivators, light stabilizers, heat stabilizers, ultraviolet absorbers, antibacterial and antifungal agents, deodorants, conductivity imparting agents, dispersants, softeners, plasticizers, crosslinking agents, co-crosslinking agents, vulcanizing agents, vulcanization aids, foaming agents, foaming aids, flame retardants, vibration damping agents, nucleating agents, neutralizing agents, lubricants, anti-blocking agents, dispersants, fluidity improvers, mold release agents, and other additives. The above additives refer to those excluding the above-described components (for example, the above thermoplastic resin, the above continuous reinforcing fiber, the components contained in the above hybrid thermoplastic resin composition, and the components contained in the sizing agent). The content of the additive may be 3% by mass or less based on 100% by mass of the composite material.

[0072] (Colorant) Examples of the colorant include carbon black, nigrosine, aluminum pigment, titanium dioxide, ultramarine, cyanine blue, cyanine green, quinacridone, diatomaceous earth, monoazo salt, perylene, disazo, condensed azo, isoindoline, valve handle, nickel titanium yellow, diketopyrrolopyrrole, metal salt, perylene red, metal oxide, bismuth vanadate, cobalt green, cobalt blue, anthraquinone, phthalocyanine green, phthalocyanine blue, etc. Among them, black colorants are preferred, and carbon black and nigrosine are more preferred.

[0073] The continuous fiber reinforced resin composite material of this embodiment preferably has a content of continuous reinforcing fibers of 90 to 525 parts by mass and a content of components other than these of 0 to 2 parts by mass with respect to 100 parts by mass of the thermoplastic resin. More preferably, with respect to 100 parts by mass of the thermoplastic resin, the content of continuous reinforcing fibers is 150 to 340 parts by mass, and the content of components other than these is 0 to 1 part by mass. The continuous fiber reinforced resin composite material of this embodiment may be a composite material composed only of a thermoplastic resin and continuous reinforcing fibers.

[0074] [Applications of Continuous Fiber Reinforced Resin Composite Materials] The continuous fiber reinforced resin composite material of this embodiment can be preferably used for structural material applications such as aircraft, automobiles, building materials, and robots. In the case of automotive applications, although not limited to the following, for example, it can be used for chassis / frame, underbody, drive system parts, interior parts, exterior parts, functional parts, and other parts. Specifically, the steering shaft, mount, sunroof, step, surf trim, door trim, trunk, boot lid, bonnet, seat frame, seat back, retractor, retractor support bracket, clutch, gear, pulley, cam, argae, elastic beam, buffering, lamp, reflector, glazing, front end module, back door inner, brake pedal, steering wheel, electrical components, sound absorbing material, door exterior, interior panel, instrument panel, rear gate, ceiling rib, seat, seat frame assembly, wiper pillar, EPS (Electric Power Steering), small motor, heat sink, ECU (Engine Control Unit) box, ECU housing, steering gear box housing, plastic housing, housing for EV (Electric Vehicle) motor, wire harness, in-vehicle meter, combination switch, small motor, spring, damper, wheel, wheel cover, frame, sub-frame, side frame, two-wheeled frame, fuel tank, oil pan, intake manifold, propeller shaft, drive motor, monocoque, hydrogen tank, electrodes of fuel cell, panel, floor panel, outer panel, door, cabin, roof, hood, valve, EGR (Exhaust GasRecirculation) valve, variable valve timing unit, connecting rod, cylinder bore, member (engine mounting, front floor cross, footwell cross, seat cross, inner side, rear cross, suspension, pillar reinforcement, front side, front panel, upper, dash panel cross, steering), tunnel, fastening insert, crash box, crash rail, corrugate, roof rail, upper body, side rail, bradding, door surround assembly, airbag member, body pillar, dash to pillar gasket, suspension tower, bumper, body pillar lower, front body pillar, reinforcement (instrument panel, rail, roof, front body pillar, roof rail, roof side rail, rocker, door belt line, front floor under, front body pillar upper, front body pillar lower, center pillar, center pillar hinge, door outer panel), side outer panel, front door window frame, MICS (Minimum Intrusion CabinSystem) Bulk, torque box, radiator support, radiator fan, water pump, fuel pump, electronic control throttle body, engine control ECU, starter, alternator, manifold, transmission, clutch, dash panel, dash panel insulator pad, door side impact protection beam, bumper beam, door beam, bulkhead, outer pad, inner pad, rear seat rod, door panel, door trim bodysub assembly, energy absorber (bumper, shock absorption), shock absorber, shock absorption garnish, pillar garnish, roof side inner garnish, resin rib, side rail front spacer, side rail rear spacer, seat belt pretensioner, airbag sensor, arm (suspension, lower, hood hinge), suspension link, shock absorption bracket, fender bracket, inverter bracket, inverter module, hood inner panel, hood panel, cowl louver, cowl top outer front panel, cowl top outer panel, floor silencer, dump seat, hood insulator, fender side panel protector, cowl insulator, cowl top ventilator loop, cylinder head cover, tire deflector, fender support, strut tower bar, mission center tunnel, floor tunnel, radiator core support, luggage panel, luggage floor, accelerator pedal, accelerator pedal base, etc. can be suitably used as parts.

[0075] [Molding of composite materials] The continuous fiber reinforced resin composite material of this embodiment can be further molded. Examples of the above method include cutting the continuous fiber reinforced resin composite material of this embodiment into a predetermined size, heating it with an infrared heater, and performing hot compression pressing with a press molding machine.

Examples

[0076] Hereinafter, the present invention will be specifically described with reference to examples and comparative examples. However, the present invention is not limited to these examples, and it goes without saying that various modifications can be made and implemented within the scope of the gist of the present invention.

[0077] [Interface coating rate change index, reinforcing fiber exposure change index, relative elemental concentration change index of continuous fiber reinforced resin composite material] When using 100 mg of the continuous fiber-reinforced resin composite material cut into flakes and Resins 1 to 4, 20 mL of HFIP was placed in a mixing rotor. When using Resin 5, 20 mL of xylene was placed in a mixing rotor. When using HFIP, it was stirred at a temperature of 23 °C for 5 hours, and when using xylene, it was stirred at a temperature of 90 °C for 5 hours. After that, the solvent was removed by suction filtration. 40 mL of fresh solvent was poured onto the filter to wash the continuous reinforcing fibers. When using HFIP, it was air-dried, and when using xylene, it was heat-dried in an environment of 120 °C. The obtained continuous reinforcing fibers and 20 mL of fresh solvent were placed in a mixing rotor and stirred at a temperature of 23 °C when using HFIP and at a temperature of 90 °C when using xylene for 2 hours. After that, the solvent was removed by suction filtration. 40 mL of fresh solvent was poured onto the filter to wash the continuous reinforcing fibers. When using HFIP, it was dried by nitrogen blowing at a temperature of 23 °C, and when using xylene, it was dried by nitrogen blowing in an environment of 120 °C. The obtained continuous reinforcing fibers and 20 mL of fresh solvent were placed in a mixing rotor, stirred at a temperature of 23 °C when using HFIP and at a temperature of 90 °C when using xylene for 2 hours, the solvent was removed by suction filtration, 40 mL of fresh solvent was poured onto the filter to wash the continuous reinforcing fibers. When using HFIP, it was air-dried, and when using xylene, it was heat-dried in an environment of 120 °C. When using HFIP, it was dried overnight in a vacuum dryer set at a temperature of 23 °C, and when using xylene, it was dried overnight in a vacuum dryer set at 120 °C. The obtained continuous reinforcing fibers were pressed into a flat plate, small pieces of 2 mm were taken out, and using XPS (Versa probeII, ULVAC-PHI, Inc.), the excitation source was mono.AlKα 20 kV×5 mA 100 W, the analysis size was 100 μm×1.4 mm, the photoelectron extraction angle was 45°, the capture region (Survey scan): 117.4 eV, (Narrow scan): C1s, O1s, N1s, Si2p, Ca2p, Al2p, Pass Energy (Survey scan): 117.4 eV, (Narrow scan): 46.95 eV for measurement, and the relative elemental concentrations of carbon, oxygen, nitrogen, silicon, aluminum, and calcium were determined. The interfacial coating rate of the continuous fiber-reinforced resin composite material was determined by the following formula 1 in Examples 1 to 4, 6, and Comparative Examples 1 to 3, by the following formula 2 in Example 5, and by the following formula 3 in Example 7. (Interfacial coating rate)=[N] / ([N]+[Si])×100 (1) (Interface coverage rate) = [N] / ([N] + [O]) × 100 (2) (Interface coverage rate) = ([C] - [C0]) / ([C] - [C0] + [Si]) × 100 (3) The exposed ratio of reinforcing fibers in the composite material was determined by the following formula (4) in Examples 1 to 4, 6, 7, and Comparative Examples 1 to 3, and by the following formula (5) in Example 5. (Exposed ratio of reinforcing fibers in the continuous fiber reinforced resin composite material) = [Al] / [Al0] (4) (Exposed ratio of reinforcing fibers in the continuous fiber reinforced resin composite material) = [O] / [O0] (5) [Al0] is the relative elemental concentration of aluminum when GF0 is used, and [C0] is the relative elemental concentration of aluminum when CF0 is used. The interface coverage rate change index, the reinforcing fiber exposure change index, and the relative elemental change index of each element were determined by the following formulas. (Interface coverage rate change index) = (Interface coverage rate of the continuous fiber reinforced resin composite material before the fracture test) / (Interface coverage rate of the composite material after the fracture test) (Reinforcing fiber exposure change index) = (Exposed ratio of reinforcing fibers in the continuous fiber reinforced resin composite material before the fracture test) / (Exposed ratio of reinforcing fibers in the composite material after the fracture test) (Relative elemental change index of interfacial nitrogen) = (Relative elemental index of interfacial nitrogen in the continuous fiber reinforced resin composite material before the fracture test) / (Relative elemental index of interfacial nitrogen in the composite material after the fracture test) (Relative elemental change index of interfacial oxygen) = (Relative elemental index of interfacial oxygen in the continuous fiber reinforced resin composite material before the fracture test) / (Relative elemental index of interfacial oxygen in the composite material after the fracture test) (Relative elemental change index of interfacial carbon) = (Relative elemental index of interfacial carbon in the continuous fiber reinforced resin composite material before the fracture test) / (Relative elemental index of interfacial carbon in the composite material after the fracture test) (Relative elemental change index of interfacial silicon) = (Relative elemental index of interfacial silicon in the continuous fiber reinforced resin composite material before the fracture test) / (Relative elemental index of interfacial silicon in the composite material after the fracture test) (Relative elemental change index of interfacial aluminum) = (Relative elemental index of interfacial aluminum in the continuous fiber reinforced resin composite material before the fracture test) / (Relative elemental index of interfacial aluminum in the composite material after the fracture test) (Relative element change index of interfacial calcium) = (Relative element index of interfacial calcium of continuous fiber reinforced resin composite material before fracture test) / (Relative element index of interfacial calcium of composite material after fracture test) The above fracture test is the one-handed bending vibration fatigue test described below.

[0078] [Impregnation rate] As a molding machine, a hydraulic molding machine (Shoji Co., Ltd.) with a maximum clamping force of 50 tons was used. Five continuous reinforced fiber base materials and six thermoplastic resin films were alternately stacked and placed in a mold equipped with a temperature sensor, and then put into a hot press molding machine set at the melting temperature of the thermoplastic resin + 65°C. While monitoring the temperature, press at a pressure of 5 MPa. After reaching the melting temperature of the thermoplastic resin, take it out of the hot press molding machine 30 seconds later and put it into a cooling press machine, and cool it with water cooling at a pressure of 5 MPa. At this time, the maximum temperature of the continuous fiber reinforced resin composite material was the melting point of the thermoplastic resin + 15°C, and the time above the melting temperature of the thermoplastic resin was 1 minute. The obtained continuous reinforced fiber composite material was cut with a band saw, and after polishing the cross section so that the continuous reinforced fibers were not damaged, from the image obtained by FE-SEM observation at a magnification of 50 times, the occupied areas of the continuous reinforced fiber bundles, thermoplastic resin, and voids were obtained by ImageJ respectively, and the ratio of the void area to the area of the continuous reinforced fiber bundles (total) was obtained. The following formula: Impregnation rate (%) = {1 - (void area / continuous reinforced fiber bundle area)} × 100 The impregnation rate (%) calculated by the above formula was divided by the time (minutes) when the temperature of the thermoplastic resin was above the melting temperature during hot press molding and cooling press to obtain the impregnation rate (% / min). Here, the continuous reinforced fiber bundle is a region where the fibers (bundles of single filaments) in the cross section of the injection molded product are densely packed. For example, it can be regarded as a region connecting the outer peripheries of the densely packed fibers. Here, the above melting temperature is the melting point when the thermoplastic resin has a melting point, and the glass transition temperature when it does not have a melting point.

[0079] [Bending strength] A strip-shaped test piece with a length of 100 mm, a width of 10 mm, and a thickness of 2 mm was cut out from a continuous fiber-reinforced resin composite material. Using a three-point bending jig on an Instron universal testing machine, with the span set to 32 mm and a speed of 1 mm / min, the bending strength (MPa) was measured under the environment of 23°C and 50% RH. Fifty measurements were taken, and the median value was taken as the bending strength.

[0080] [Flexural vibration fatigue recovery characteristics] Test pieces of ASTM-D671 Type A were prepared from a continuous fiber-reinforced resin composite material. Using a repeated vibration fatigue testing machine (B-70, manufactured by Toyo Seiki Seisakusho Co., Ltd.), a one-handed flexural vibration fatigue test was carried out at a test temperature of 23°C, a frequency of 20 Hz, and a sine wave waveform. The number of judgment cycles (A) of the vibration fatigue test at a stress corresponding to 35% of the bending strength of the continuous fiber-reinforced resin composite material of each example was determined. Similarly, a vibration fatigue test was carried out at a stress corresponding to 35% of the bending strength. The test was stopped when the number of cycles reached half of (A), and a test piece after fracture was obtained. The test piece after fracture was placed in a mold with an inlay structure, and a hydraulic molding machine (Shoji Co., Ltd.) with a maximum clamping force of 50 tons was used. The temperature inside the molding machine was heated to 200°C, then clamped with a clamping force of 5 MPa, and a heating press was carried out for 15 minutes to obtain a test piece after recovery. The test piece after recovery was subjected to a flexural vibration fatigue test under the same conditions, and the number of judgment cycles (B) was determined. The flexural vibration fatigue recovery characteristics were determined by the following formula. (Flexural vibration fatigue characteristics) = (B) / (A)

[0081] [Measurement of variation] The bending strength test was carried out on 50 test pieces to measure the bending strength. The average value of the bending strength was A, and the bending strength in the i-th measurement (i = 1 to 50) was Ai. The coefficient of variation was determined according to the following formula and taken as the variation. [Number]

[0082] The materials used in the examples and comparative examples are as follows. [Continuous reinforcing fiber] (Glass fiber) Glass fiber 1 (GF1): Based on 100% by mass of glass fiber with a fineness of 1.15 g / m and 2000 filaments per single yarn, 0.8% by mass of a sizing agent was adhered. The winding form was DWR, and the average single fiber diameter was about 16 μm. For the adhesion of the sizing agent, an aqueous sizing agent solution prepared by adjusting with deionized water was used so that it contained 0.8% by mass of γ-aminopropyltrimethoxysilane (KBM-903, manufactured by Shin-Etsu Chemical Co., Ltd.), 1.2% by mass of carnauba wax, and 2% by mass of a copolymer compound with a weight average molecular weight of 15,000 obtained by copolymerizing 10% by mass of maleic anhydride and 90% by mass of methyl methacrylate. Each component adhered to the glass fiber was 0.16% by mass of γ-aminopropyltrimethoxysilane, 0.40% by mass of carnauba wax, and 0.24% by mass of the copolymer compound with respect to 100% by mass of the glass fiber. Glass fiber 2 (GF2): The glass fiber obtained by treating GF1 in an electric furnace at 650 °C for 3 hours was immersed in a 0.2% by mass aqueous solution of γ-aminopropyltrimethoxysilane (KBM-903, manufactured by Shin-Etsu Chemical Co., Ltd.), a coupling agent, for 30 minutes and dried at 110 °C for 3 hours. The γ-aminopropyltrimethoxysilane adhered to the glass fiber was 0.16% by mass with respect to 100% by mass of the glass fiber. Glass fiber 0 (GF0): GF1 was treated in an electric furnace at 650 °C for 3 hours to obtain GF0 without a sizing agent.

[0083] (Carbon fiber) Carbon fiber 1 (CF1): 100% by mass of PAN-based carbon fibers with a single fiber fineness of 12,000 was produced with 1.0% by mass of a sizing agent attached thereto. For the attachment of the sizing agent, an aqueous sizing agent solution was prepared by adjusting with deionized water so that it contained 0.8% by mass of γ-aminopropyltrimethoxysilane (KBM-903, manufactured by Shin-Etsu Chemical Co., Ltd.), 0.3% by mass of carnauba wax, and 1% by mass of a copolymer compound with a weight average molecular weight of 20,000 obtained by copolymerizing 10% by mass of maleic anhydride and 90% by mass of methyl methacrylate. Each component attached to the carbon fibers was 0.38% by mass of γ-aminopropyltrimethoxysilane, 0.48% by mass of carnauba wax, and 0.14% by mass of the copolymer compound with respect to 100% by mass of the carbon fibers. Carbon fiber 2 (CF2): PAN-based carbon fibers with a single fiber fineness of 12,000 were immersed in an aqueous solution containing 0.38% by mass of γ-aminopropyltrimethoxysilane (KBM-903, manufactured by Shin-Etsu Chemical Co., Ltd.), which is a coupling agent, at 60°C for 12 hours and then dried at 110°C for 6 hours. The γ-aminopropyltrimethoxysilane attached to the carbon fibers was 0.38% by mass with respect to 100% by mass of the carbon fibers. Carbon fiber 0 (CF0): PAN-based carbon fibers with a single fiber fineness of 12,000

[0084] [Production of continuous reinforced fiber base material] Glass cloth: Using a rapier loom (loom width 1 m), glass cloth 1 (GC1) was produced by weaving using the above GF1 as the warp and weft. The woven form of the obtained glass cloth was plain weave, the weave density was 6.5 threads / 25 mm, and the areal density was 640 g / m 2 It was like this. Similarly, GC2 was obtained using GF2. Carbon fiber cloth: Using a rapier loom (loom width 1 m), carbon fiber cloth 1 (CC1) was produced by weaving using the above carbon fiber 1 as the warp and weft. The woven form of the obtained carbon fiber cloth was plain weave, the weave density was 6.5 threads / 25 mm, and the areal density was 425 g / m 2 It was like this. Similarly, CC2 was obtained using carbon fiber 2.

[0085] [Thermoplastic resin] Resin 1: Polyamide 66 The polymerization reaction of polyamide was carried out as follows by the "thermal melt polymerization method". 1500 g of a salt containing adipic acid (Wako Pure Chemical Industries) and hexamethylenediamine (Tokyo Chemical Industry) in a molar ratio of 45:55 and 300 g of adipic acid were dissolved in 1500 g of distilled water to prepare a 55 mass% homogeneous aqueous solution of the raw material monomers. This aqueous solution was charged into an autoclave with an internal volume of 7.0 L and purged with nitrogen. While stirring at a temperature of 130°C or higher and 150°C or lower, water vapor was gradually removed to concentrate the solution to a concentration of 70 mass%. Then, the internal temperature was raised to 225°C. At this time, the pressure in the autoclave increased to 1.7 MPa. While gradually removing water vapor and maintaining the pressure at 1.7 MPa, the reaction was carried out for 70 minutes until the internal temperature reached 255°C for 2 hours. Next, the pressure was reduced over 1.7 hours. Then, the inside of the autoclave was maintained under a reduced pressure of 650 torr for 15 minutes with a vacuum device. At this time, the final internal temperature of the polymerization was 265°C. Then, it was pressurized with nitrogen and formed into strands from the lower spinning nozzle (nozzle), cooled with water, cut, discharged in pellet form, and dried at 100°C under a nitrogen atmosphere for 12 hours. The obtained pellets and a lubricant (PEG400, Tokyo Chemical Industry) were molded with a single-screw extruder, cooled with water, cut, discharged in pellet form, and dried at 100°C under a nitrogen atmosphere for 12 hours to obtain Resin 1 (polyamide 66). Mw = 42000, Mw / Mn = 2.08, melting temperature (melting point (Tm)) = 264°C, glass transition temperature (Tg) = 50°C. Resin 2: To 100 mass% of Resin 1, 0.03 mass% of copper iodide and 0.2 mass% of potassium iodide were dry-blended, kneaded with a twin-screw kneader (TEM26SS, Toshiba Machine) set at 280°C, cooled with water, cut, discharged in pellet form, and dried at 100°C under a nitrogen atmosphere for 12 hours to obtain Resin 2 with a melting temperature of 264°C. Resin 3: Polyamide 6I The polymerization reaction of polyamide was carried out as follows by the "thermal melt polymerization method". A salt containing an equimolar salt of isophthalic acid (Wako Pure Chemical Industries) and hexamethylenediamine in a molar ratio of 45:55: 1500 g, and 300 g of isophthalic acid were dissolved in 1500 g of distilled water to prepare a homogeneous aqueous solution. While stirring at a temperature of 110°C or higher and 140°C or lower, water vapor was gradually removed until the solution concentration reached 70% by mass and concentrated. Then, the internal temperature was raised to 235°C. As it was, for 70 minutes, until the internal temperature reached 245°C, water vapor was gradually removed while maintaining a constant pressure and reacted for 2 hours. Next, the pressure was reduced over 90 minutes. Then, the inside of the autoclave was maintained under a reduced pressure of 650 torr with a vacuum device for 10 minutes. At this time, the final internal temperature of the polymerization was 265°C. Then, it was pressurized with nitrogen and made into strands from the lower spinning nozzle, water-cooled, cut, and discharged in the form of pellets. The pellets were dried at 100°C in a nitrogen atmosphere for 12 hours. The obtained pellets and a lubricant (PEG400, Tokyo Chemical Industry) were molded with a single-screw extruder, water-cooled, cut, and discharged in the form of pellets, and dried at 100°C in a nitrogen atmosphere for 12 hours to obtain Resin 3 (polyamide 6I). The obtained Resin 3 (polyamide 6I) had Mw = 18000, Mw / Mn = 1.94, and a melting temperature (glass transition temperature (Tg)) = 130°C. In the case of an amorphous resin having no crystal melting point, the glass transition temperature is taken as the melting temperature. Resin 4: Resin 1 and Resin 3 were dry-blended at a mass ratio of 2:1 to obtain Resin 4 with a melting temperature of 259°C. Resin 5: Maleic acid-modified polypropylene (Sanyo Chemical Industries, Ltd., melting temperature (melting point) = 160°C)

[0086] [Production of thermoplastic resin film] A thermoplastic resin film was obtained by molding using a T-die extrusion molding machine (manufactured by Soken Co., Ltd.). The thickness of the thermoplastic resin film was 180 μm.

[0087] [Example 1] Using Resin 1, Thermoplastic Resin Film 1 was obtained by the above method. Four glass cloths 1 (GC1) and five thermoplastic resin films 1 were prepared. The glass cloth 1 and the thermoplastic resin film 1 were alternately stacked so that the thermoplastic resin film 1 was on the surface, and molding was performed to obtain a continuous fiber reinforced resin composite material with a thickness of 2 mm. A continuous compression molding machine was used as the molding machine. The above glass cloth and the above thermoplastic resin film 1 were stacked as described above and installed in the molding machine. The temperature of the heating zone in the molding machine was adjusted to 350 °C, and the cooling zone was oil-cooled. Compression molding was performed at a pressure of 5 MPa and a belt speed of 0.6 m / min. Also, in order to compare the flexural strength, a bending test material (coupling continuous fiber reinforced resin composite material) with a thickness of 2 mm was obtained in the same manner using a glass cloth 2 (coupling continuous reinforcing fiber) treated only with a coupling agent. Table 1 shows the physical properties of the obtained continuous fiber reinforced resin composite material.

[0088] [Example 2] A continuous fiber reinforced resin composite material with a thickness of 2 mm and a bending test material (coupling continuous fiber reinforced resin composite material) were obtained in the same manner as in Example 1, except that resin 2 was used as the thermoplastic resin. Table 1 shows the physical properties of the obtained continuous fiber reinforced resin composite material.

[0089] [Example 3] A continuous fiber reinforced resin composite material with a thickness of 2 mm and a bending test material (coupling continuous fiber reinforced resin composite material) were obtained in the same manner as in Example 1, except that resin 3 was used as the thermoplastic resin. Table 1 shows the physical properties of the obtained continuous fiber reinforced resin composite material.

[0090] [Example 4] A continuous fiber reinforced resin composite material with a thickness of 2 mm and a bending test material (coupling continuous fiber reinforced resin composite material) were obtained in the same manner as in Example 1, except that resin 4 was used as the thermoplastic resin. Table 1 shows the physical properties of the obtained continuous fiber reinforced resin composite material.

[0091] [Example 5] A continuous fiber reinforced resin composite material with a thickness of 2 mm was obtained in the same manner as in Example 1, except that carbon fiber cloth 1 was used as the continuous reinforcing fiber base material, and a composite material composed of carbon fiber cloth 1 and thermoplastic resin film 1 was produced. Note that as the thermoplastic resin film, a film produced in the same manner as the above thermoplastic resin film was used, except that the thickness was 118 μm. Also, in order to compare the flexural strength, a bending test material (coupling continuous fiber reinforced resin composite material) with a thickness of 2 mm was obtained in the same manner using carbon fiber cloth 2 treated only with a coupling agent. Table 1 shows the physical properties of the obtained continuous fiber reinforced resin composite material.

[0092] [Example 6] A continuous fiber reinforced resin composite material with a thickness of 2 mm was obtained in the same manner as in Example 1, except that glass fiber cloth GC3 was produced using glass fiber treated with 20 wt% aqueous sodium aluminate solution as an additive for adjusting the aluminum concentration in GF1 for 1 hour and dried at 110°C for 2 hours instead of GF1. The bending test material (coupling continuous fiber reinforced resin composite material) was produced in the same manner as in Example 1. Table 1 shows the physical properties of the obtained continuous fiber reinforced resin composite material.

[0093] [Example 7] A continuous fiber reinforced resin composite material with a thickness of 2 mm and a bending test material were obtained in the same manner as in Example 1, except that resin 5 was used as the thermoplastic resin. Table 1 shows the physical properties of the obtained continuous fiber reinforced resin composite material.

[0094] [Comparative Example 1] Instead of glass cloth 1, glass fiber (GF4) to which a mixture of 0.16 mass% of 3-glycidoxypropyltrimethoxysilane (KBM-402, Shin-Etsu Chemical Co., Ltd.), 0.40 mass% of epoxy resin emulsion, and 0.24 mass% of carnauba wax was attached as a sizing agent was used for 100 mass% of the glass fiber used in the production of GF1. Plain weave, weave density is 6.5 threads / 25 mm, basis weight 600 g / m 2A continuous fiber-reinforced resin composite material was obtained in the same manner as in Example 1, except that a glass cloth (GC4) was produced and used. Also, in order to compare the flexural strength, with respect to 100% by mass of the glass fiber used for producing GF1, as a coupling agent, glass fiber (coupling continuous reinforcing fiber, GF5) to which 0.16% by mass of 3-glycidoxypropyltrimethoxysilane (KBM-402, Shin-Etsu Chemical Co., Ltd.) was adhered was used, and plain weave was performed with a weave density of 6.5 threads / 25 mm and a basis weight of 600 g / m 2 Using a glass cloth (GC5) of, a bending test material (coupling continuous fiber-reinforced resin composite material) having a thickness of 2 mm was obtained in the same manner. Table 1 shows the physical properties of the obtained continuous fiber-reinforced resin composite materials.

[0095] [Comparative Example 2] Instead of the glass cloth 1, glass fiber (GF6) having a fineness of 1.15 g / m and 2000 filaments per single yarn without treatment with a sizing agent was used, and plain weave was performed with a weave density of 6.5 threads / 25 mm and a basis weight of 640 g / m 2 A continuous fiber-reinforced resin composite material and a bending test material were obtained in the same manner as in Example 1, except that a glass cloth (GC6) was produced and used. Table 1 shows the physical properties of the obtained continuous fiber-reinforced resin composite materials.

[0096] [Comparative Example 3] Using "Tepex dynalite 101" manufactured by Bond Laminate in which polyamide 66 was impregnated into a glass cloth, the same evaluation as in Example 1 was performed. Table 1 shows the physical properties of the obtained continuous fiber-reinforced resin composite materials.

[0097] Table 1 shows the impregnation rate and flexural strength when using glass cloth 2 or carbon fiber cloth 2.

[0098]

Table 1

Industrial Applicability

[0099] The continuous fiber reinforced resin composite material of this embodiment can be industrially used as a reinforcing material for materials that require high-level mechanical properties, such as structural parts of various machines and automobiles, and also as a composite molded body material with a thermoplastic resin composition.

Claims

1. A method for manufacturing a continuous fiber reinforced resin composite material, wherein the impregnation rate of the thermoplastic resin into the continuous reinforcing fibers is 0.8 to 1.2 times the impregnation rate of the thermoplastic resin into the coupling continuous reinforcing fibers treated only with a coupling agent, the flexural strength of the coupling continuous fiber reinforced resin composite material composed of the coupling continuous reinforcing fibers and the thermoplastic resin is 0.6 times or more the flexural strength of the continuous fiber reinforced resin composite material, the continuous reinforcing fibers are continuous reinforcing fibers to which a sizing agent containing a silane coupling agent which is aminosilanes adheres, characterized in that it is a method for manufacturing a continuous fiber reinforced resin composite material.

2. The method for manufacturing a continuous fiber reinforced resin composite material according to claim 1, wherein the interfacial coating rate change index represented by the following formula of the continuous fiber reinforced resin composite material is 0.8 to 1.

2. (Interfacial coating rate change index) = (Interfacial coating rate of the continuous fiber reinforced resin composite material before the fracture test) / (Interfacial coating rate of the continuous fiber reinforced resin composite material after the fracture test) 3. A method for manufacturing a continuous fiber reinforced resin composite material according to claim 1, wherein a step of setting the continuous reinforcing fibers and the thermoplastic resin in a mold, a melting step of melting the thermoplastic resin, and a compression step of compressing the mold to shape the continuous fiber reinforced resin composite material, characterized in that it is a method for manufacturing a continuous fiber reinforced resin composite material.

4. The method for manufacturing a continuous fiber reinforced resin composite material according to claim 3, wherein the mold clamping pressure in the compression step is 1 MPa or more.

5. The method for manufacturing a continuous fiber reinforced resin composite material according to claim 1, including a step of installing the continuous reinforcing fibers and the thermoplastic resin in a mold and compressing them with a double belt press machine, or a step of installing a mold frame so as to surround the four sides of the installed continuous reinforcing fibers and the thermoplastic resin and compressing them with a double belt press machine.

6. A method for manufacturing a continuous fiber reinforced resin composite material according to claim 1, including a step of preparing a compression molding machine set at one or more temperatures for heating and a compression molding machine set at one or more temperatures for cooling, and sequentially feeding the mold in which the continuous reinforcing fibers and the thermoplastic resin are installed into the compression molding machines for molding.

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