Method for manufacturing continuous fiber-reinforced thermoplastic resin sheet

Abstract

Provided are, inter alia, a manufacturing method that can be carried out using simple equipment and that makes it possible to efficiently manufacture many continuous fiber-reinforced thermoplastic resin sheets in a short period of time.　The above problem is overcome by a method for manufacturing a continuous fiber-reinforced thermoplastic resin sheet comprising: an impregnation step for impregnating continuous fiber with a thermoplastic resin solution containing a halogen-containing organic solvent and a thermoplastic resin containing at least one resin from among polycarbonate resins and polyarylate resins; and a solvent removal step for removing, under exposure to IR radiation, the halogen-containing organic solvent from the continuous fiber impregnated with the thermoplastic resin solution. In the solvent removal step, the distance between a heater for emitting the IR radiation and the continuous fiber is 400 mm or less, and the temperature of a heating element for radiating the IR radiation in the heater is 260°C or higher.

Description

Method for producing continuous fiber reinforced thermoplastic resin sheet

[0001] The present invention relates to a method for producing a continuous fiber reinforced thermoplastic resin sheet such as a prepreg.

[0002] Fiber-reinforced thermoplastic resins with a thermoplastic resin matrix have been known. For example, intermediate materials for composite materials made of reinforcing fibers such as glass fibers and a thermoplastic polymer (Patent Document 1), fiber-reinforced composite materials with a thermoplastic resin matrix reinforced with conductive fibers (Patent Document 2), and carbon fiber-reinforced thermoplastic resins (CFRTPs: Patent Documents 3 to 5), which are composite materials combining carbon fibers and a thermoplastic resin, are used in a variety of fields. Carbon fiber-reinforced thermoplastic resins are suitable for use in aircraft components, spacecraft components, automobile components, ship components, electronic equipment components, and sports-related components.

[0003] From the above-mentioned fiber-reinforced thermoplastic resin such as CFRTP, continuous fiber-reinforced thermoplastic resin sheets such as prepregs are usually produced. In this way, continuous fiber-reinforced thermoplastic resin sheets produced from fiber-reinforced thermoplastic resins and the like are widely used as materials for products for the above-mentioned various applications, for example.

[0004] Japanese Patent Application Laid-Open No. 4-85337 Japanese Patent Application Laid-Open No. 2005-225993 International Publication No. 2018 / 216516 International Publication No. 2018 / 216517 International Publication No. 2018 / 216518

[0005] It can be said that the conventional manufacturing process of continuous fiber reinforced thermoplastic resin sheets has not always been carried out efficiently. That is, the conventional manufacturing process of continuous fiber reinforced thermoplastic resin sheets requires relatively large-scale equipment, and it cannot be said that the manufacturing efficiency of the production line of the conventional manufacturing method has been sufficiently improved. The main problem to be solved by the present invention is to provide a manufacturing method that can be carried out with simple equipment and can efficiently produce many continuous fiber reinforced thermoplastic resin sheets in a short time.

[0006] As a result of intensive studies to solve the above problems, the present inventor has found that the production efficiency of fiber-reinforced thermoplastic resin sheets can be improved in a manufacturing method in which the solvent is efficiently removed from an intermediate material of a fiber-reinforced thermoplastic resin sheet containing a solvent in a simple process.

[0007] The present invention includes the following: [1] A method for producing a continuous fiber-reinforced thermoplastic resin sheet, comprising: an impregnation step of impregnating continuous fibers with a thermoplastic resin solution containing a thermoplastic resin including at least one of a polycarbonate resin and a polyarylate resin, and a halogen-containing organic solvent; and a solvent removal step of removing the halogen-containing organic solvent from the continuous fibers impregnated with the thermoplastic resin solution by irradiating the continuous fibers with infrared rays, wherein in the solvent removal step, the distance between a heater irradiating the infrared rays and the continuous fibers is 400 mm or less, and the temperature of a heating element in the heater radiating the infrared rays is 260°C or higher. [2] The method for producing a continuous fiber-reinforced thermoplastic resin sheet according to [1] above, wherein the halogen-containing organic solvent includes dichloromethane. [3] The method for producing a continuous fiber-reinforced thermoplastic resin sheet according to [1] or [2] above, wherein in the solvent removal step, the distance between the heater and the continuous fibers is 100 mm or more and 410 mm or less. [4] The method for producing a continuous fiber-reinforced thermoplastic resin sheet according to any one of [1] to [3] above, wherein the temperature of the heating element in the heater is 300°C or higher and 400°C or lower in the solvent removal step. [5] The method for producing a continuous fiber-reinforced thermoplastic resin sheet according to any one of [1] to [4] above, wherein the heater irradiates far infrared rays having a wavelength range of 2 μm to 20 μm in the solvent removal step. [6] The method for producing a continuous fiber-reinforced thermoplastic resin sheet according to any one of [1] to [5] above, wherein the concentration of the thermoplastic resin in the thermoplastic resin solution is 10 to 30 mass%. [7] The method for producing a continuous fiber-reinforced thermoplastic resin sheet according to any one of [1] to [6] above, wherein the rate at which the thermoplastic resin solution is impregnated into the continuous fibers in the impregnation step is 0.3 m / min to 3.0 m / min. [8] The method for producing a continuous fiber-reinforced thermoplastic resin sheet according to any one of [1] to [7] above, wherein the infrared irradiation time in the solvent removal step is 2 minutes to 15 minutes. [9] The proportion of the thermoplastic resin in the continuous fiber reinforced thermoplastic resin sheet is 15 to 50% by mass, according to any one of [1] to [8]. The method for producing a continuous fiber reinforced thermoplastic resin sheet.

[10] The continuous fiber reinforced thermoplastic resin sheet according to any one of [1] to [9], wherein the content of residual halogen-containing organic solvent in the continuous fiber reinforced thermoplastic resin sheet is less than 1000 ppm by mass. The method for producing a thermoplastic resin sheet.

[0008]

[11] The thermoplastic resin has a structural unit derived from a dihydric phenol represented by the following general formula (1), [1] to

[10] . A method for producing a continuous fiber-reinforced thermoplastic resin sheet. (In general formula (1), R １ ~R ４ each independently represents hydrogen, halogen, a nitro group, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 5 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, an aralkyl group having 7 to 17 carbon atoms which may have a substituent, or an alkenyl group having 2 to 15 carbon atoms which may have a substituent; X represents -O-, -S-, -SO-, -SO ２ -, -CO-, or a divalent group represented by any one of the following formulas (2) to (5): (In formula (2), R ５ and R ６ each independently represents hydrogen, halogen, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 5 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, an aralkyl group having 7 to 17 carbon atoms which may have a substituent, or an alkenyl group having 2 to 15 carbon atoms which may have a substituent, or ５ and R ６ are bonded to each other to form a carbocyclic ring having 3 to 20 carbon atoms or a heterocyclic ring having 1 to 20 carbon atoms; and c represents an integer of 0 to 20. ７ and R ８ each independently represents hydrogen, halogen, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 5 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, an aralkyl group having 7 to 17 carbon atoms which may have a substituent, or an alkenyl group having 2 to 15 carbon atoms which may have a substituent, or ７ and R８ are bonded to each other to form a carbocyclic ring having 3 to 20 carbon atoms or a heterocyclic ring having 1 to 20 carbon atoms.) (In formula (4), R ９ ~R １２ each independently represents hydrogen, halogen, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 5 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, an aralkyl group having 7 to 17 carbon atoms which may have a substituent, or an alkenyl group having 2 to 15 carbon atoms which may have a substituent, each of the substituents being independently halogen, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and R ９ and R １０ and R １１ and R １２ may be bonded to each other to form a carbon ring having 3 to 20 carbon atoms or a hetero ring having 1 to 20 carbon atoms.) (In formula (5), R １３ ~R ２２ each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; R １３ ~R ２２wherein at least one of the groups is an alkyl group having 1 to 3 carbon atoms.)

[12] The method for producing a continuous fiber-reinforced thermoplastic resin sheet according to any one of [1] to

[11] above, further comprising a solution production step of dissolving the thermoplastic resin in the halogen-containing organic solvent to produce a thermoplastic resin solution.

[13] The method for producing a continuous fiber-reinforced thermoplastic resin sheet according to any one of [1] to

[12] above, further comprising a measurement step of measuring the content of residual halogen-containing organic solvent in the continuous fiber-reinforced thermoplastic resin sheet after the solvent removal step.

[14] The method for producing a continuous fiber-reinforced thermoplastic resin sheet according to any one of [1] to

[13] above, further comprising a comparison step of comparing the content of residual halogen-containing organic solvent in the continuous fiber-reinforced thermoplastic resin sheet with a predetermined threshold value after the solvent removal step.

[15] The method for producing a continuous fiber-reinforced thermoplastic resin sheet according to any one of [1] to

[14] above, wherein the continuous fibers are a single strand, a unidirectional sheet, or a woven fabric.

[16] The method for producing a continuous fiber-reinforced thermoplastic resin sheet according to any one of [1] to

[15] above, wherein the continuous fibers are carbon fibers, glass fibers, or aramid fibers.

[17] The method for producing a continuous fiber-reinforced thermoplastic resin sheet according to any one of [1] to

[16] above, wherein the continuous fiber-reinforced thermoplastic resin sheet is a prepreg.

[0009] According to the present invention, an intermediate material for a fiber-reinforced thermoplastic resin sheet is a continuous fiber impregnated with a thermoplastic resin solution containing a predetermined organic solvent. The organic solvent can be efficiently removed by irradiating the continuous fiber with infrared rays, thereby improving the production efficiency of the fiber-reinforced thermoplastic resin sheet.

[0010] The method for producing a continuous fiber-reinforced thermoplastic resin sheet of the present invention includes an impregnation step in which continuous fibers are impregnated with a thermoplastic resin solution containing a predetermined thermoplastic resin and a halogen-containing organic solvent, and a solvent removal step in which the halogen-containing organic solvent is removed from the continuous fibers impregnated with the thermoplastic resin solution by irradiating them with infrared rays. In the solvent removal step, the distance between the heater irradiating the infrared rays and the continuous fibers is adjusted to 400 mm or less, and the temperature of the infrared rays irradiated by the heater is adjusted to 260°C or higher. This method for producing a continuous fiber-reinforced thermoplastic resin sheet allows for efficient removal of solvent from a solvent-containing intermediate material of a fiber-reinforced thermoplastic resin sheet in a simple process, thereby improving the production efficiency of fiber-reinforced thermoplastic resin sheets. In particular, the production method of the present invention can improve the efficiency of the solvent removal process from the intermediate material, which is often the rate-limiting step in large-scale fiber-reinforced thermoplastic resin sheet production lines, thereby improving the production efficiency of fiber-reinforced thermoplastic resin sheets on an industrial scale. The method for producing a continuous fiber-reinforced thermoplastic resin sheet of the present invention is described in more detail below.

[0011] <1. Continuous fiber reinforced thermoplastic resin sheet> The continuous fiber reinforced thermoplastic resin sheet produced by the manufacturing method of the present invention is a thermoplastic resin sheet reinforced with continuous fibers, containing a thermoplastic resin and continuous fibers. The thermoplastic resin includes at least one of a polycarbonate resin and a polyarylate resin, which will be described in detail later. In addition, the manufacturing process of the continuous fiber reinforced thermoplastic resin sheet includes an impregnation step in which the continuous fibers are impregnated with a solution in which the thermoplastic resin is dissolved in a halogen-containing organic solvent, as will be described in detail later. Therefore, the continuous fiber reinforced thermoplastic resin sheet may contain a small amount of solvent such as a halogen-containing organic solvent. The continuous fiber reinforced thermoplastic resin sheet is, for example, a prepreg.

[0012] 1-1. Thermoplastic Resin At least one of the polycarbonate resin and polyarylate resin included in the thermoplastic resin used in the present invention has a structural unit derived from a dihydric phenol represented by the following general formula (1). For both the polycarbonate resin and the polyarylate resin, any of a homopolymer, a copolymer, or a mixture of a plurality of homopolymers or copolymers can be used. Furthermore, the thermoplastic resin may be any of a polycarbonate resin alone, a mixture of polycarbonate resins, a polyarylate resin alone, a mixture of polyarylate resins, or a mixture of polycarbonate resin and polyarylate resin. (In general formula (1), R １ ~R ４ each independently represents hydrogen, halogen, a nitro group, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 5 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, an aralkyl group having 7 to 17 carbon atoms which may have a substituent, or an alkenyl group having 2 to 15 carbon atoms which may have a substituent; X represents -O-, -S-, -SO-, -SO ２ -, -CO-, or a divalent group represented by any one of the following formulas (2) to (5): １ ~R ４ is preferably hydrogen, an alkyl group having 1 to 10 carbon atoms which may have a substituent, an alkoxy group having 1 to 3 carbon atoms which may have a substituent, an aryl group having 6 to 10 carbon atoms which may have a substituent, an aralkyl group having 7 to 12 carbon atoms which may have a substituent, or an alkenyl group having 2 to 10 carbon atoms which may have a substituent, more preferably hydrogen, an alkyl group having 1 to 10 carbon atoms which may have a substituent, an alkoxy group having 1 or 2 carbon atoms which may have a substituent, an aryl group having 6 to 8 carbon atoms which may have a substituent, an aralkyl group having 7 to 9 carbon atoms which may have a substituent, or an alkenyl group having 2 to 6 carbon atoms which may have a substituent, and particularly preferably hydrogen, an alkyl group having 1 to 6 carbon atoms which may have a substituent, or an aryl group having 6 to 7 carbon atoms which may have a substituent. In formula (2), R ５ and R ６each independently represents hydrogen, halogen, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 5 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, an aralkyl group having 7 to 17 carbon atoms which may have a substituent, or an alkenyl group having 2 to 15 carbon atoms which may have a substituent, or R ５ and R ６ are bonded to each other to form a carbon ring having 3 to 20 carbon atoms or a hetero ring having 1 to 20 carbon atoms. From the viewpoint of easy availability of raw materials, R ５ represents an alkyl group having 1 to 3 carbon atoms or an aryl group having 6 to 12 carbon atoms. From the viewpoint of availability of raw materials, R ６ represents an alkyl group having 1 to 3 carbon atoms or an aryl group having 6 to 12 carbon atoms. From the viewpoint of availability of raw materials, R ５ and R ６ are bonded to each other to form a carbon ring having 6 to 12 carbon atoms. In formula (2), c represents an integer of 0 to 20, and preferably represents 1 or 2 from the viewpoint of easy availability of raw materials.

[0013] In the above formula (3), R ７ and R ８ each independently represents hydrogen, halogen, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 5 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, an aralkyl group having 7 to 17 carbon atoms which may have a substituent, or an alkenyl group having 2 to 15 carbon atoms which may have a substituent, or ７ and R ８ are bonded to each other to form a carbon ring having 3 to 20 carbon atoms or a hetero ring having 1 to 20 carbon atoms. From the viewpoint of easy availability of raw materials, R ７ represents hydrogen or a methyl group. From the viewpoint of availability of raw materials, R ８ represents hydrogen or a methyl group. From the viewpoint of availability of raw materials, R ７ and R ８ are bonded to each other to form a carbon ring having 5 to 12 carbon atoms.

[0014] In the above formula (4), R ９ ~R １２ each independently represents hydrogen, halogen, an alkyl group having 1 to 20 carbon atoms, preferably 1 to 9 carbon atoms, which may have a substituent; an alkoxy group having 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms, which may have a substituent; an aryl group having 6 to 12 carbon atoms, preferably 6 to 8 carbon atoms, which may have a substituent; an aralkyl group having 7 to 17 carbon atoms, preferably 7 to 12 carbon atoms, which may have a substituent; or an alkenyl group having 2 to 15 carbon atoms, preferably 2 to 5 carbon atoms, which may have a substituent. ９ and R １０ and R １１ and R １２ may be bonded to each other to form a carbocyclic ring having 3 to 20 carbon atoms or a heterocyclic ring having 1 to 20 carbon atoms.

[0015] The substituents in the above formulas (1) to (4) are each independently any one of a halogen, an alkyl group having 1 to 20 carbon atoms, and an aryl group having 6 to 12 carbon atoms. In addition, when a substituent is present, the above-mentioned number of carbon atoms is the total number of carbon atoms including the carbon atoms of the substituent.

[0016] In the above formula (5), R １３ ~R ２２ each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; R １３ ~R ２２ At least one of R is an alkyl group having 1 to 3 carbon atoms. From the viewpoint of availability of raw materials, R １３ ~R ２２ each independently represents hydrogen or a methyl group.

[0017] Examples of the dihydric phenol of the general formula (1) include 2,2-bis(4-hydroxyphenyl)propane [=bisphenol A], bis(4-hydroxyphenyl)-p-diisopropylbenzene, 4,4'-dihydroxydiphenyl, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxy-3,5-diethylphenyl)propane, 2,2-bis(4-hydroxy-3-ethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-diphenylphenyl)propane, 2,2-bis(4-hydroxy-3-phenylphenyl)propane, 2,2-bis(4 -hydroxy-3,5-dibromophenyl)propane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 2,2-bis(4-hydroxyphenyl)pentane, 2,4'-dihydroxy-diphenylmethane, bis-(4-hydroxy-3-methylphenyl)methane, bis-(4-hydroxy-3-nitrophenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxy-3-methylphenyl)ethane, 3,3-bis(4-hydroxyphenyl)pentane, 1,1-bis(4-hydroxyphenyl)cyclohexane [= bisphenol Z], bis(4-hydroxyphenyl)sulfone, 2,4'-dihydroxydiphenyl sulfone, bis(4-hydroxyphenyl)sulfide, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 4,4'-dihydroxy-2,5-diethoxydiphenyl ether, 1-phenyl-1,1-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane, 1-phenyl-1,1-bis(4-hydroxy-3-methylphenyl)ethane, bis(4-hydroxyphenyl)diphenylmethane, bis(4-hydroxy-3-methylphenyl)diphenylmethane, 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 2,Examples of suitable aromatic dihydroxy compounds include 2-bis(4-hydroxyphenyl)hexafluoropropane, but bis(4-hydroxyphenyl)alkanes are preferred, and 2,2-bis(4-hydroxyphenyl)propane [bisphenol A] is particularly preferred. These aromatic dihydroxy compounds can be used alone or in combination of two or more. Polycarbonate resins are produced, for example, by interfacial polycondensation polymerization using the above-mentioned dihydric phenols and phosgene (carbonyl chloride), or by transesterification polymerization using the above-mentioned dihydric phenols and diphenyl carbonate. Polyarylate resins are produced by reacting the above-mentioned dihydric phenols with dicarboxylic acids, such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, tartaric acid, glutamic acid, o-phthalic acid, isophthalic acid, and terephthalic acid.

[0018] The polycarbonate resin used in the present invention preferably has a viscosity average molecular weight of 10,000 to 100,000, more preferably 14,000 to 60,000, and even more preferably 16,000 to 40,000, from the viewpoint of solution viscosity that makes it easy to handle as a resin solution.

[0019] Furthermore, the polyarylate resin used in the present invention preferably has a viscosity average molecular weight of 10,000 to 100,000, more preferably 14,000 to 60,000, and even more preferably 16,000 to 40,000, from the viewpoint of solution viscosity that makes it easy to handle as a resin solution.

[0020] The thermoplastic resin may contain components other than at least one of the polycarbonate resin and polyarylate resin described above, as long as the effects of the invention are achieved, and other resins and various additives such as mold release agents, flame retardants, antioxidants, heat stabilizers, flame retardant assistants, ultraviolet absorbers, colorants, antistatic agents, fluorescent brightening agents, antifogging agents, flow improvers, plasticizers, dispersants, and antibacterial agents may be blended therein.

[0021] Examples of other resins include thermoplastic polyester resins such as polyethylene terephthalate resin (PET resin), polytrimethylene terephthalate (PTT resin), and polybutylene terephthalate resin (PBT resin); styrene-based resins such as polystyrene resin (PS resin), high impact polystyrene resin (HIPS), acrylonitrile-styrene copolymer (AS resin), and methyl methacrylate-styrene copolymer (MS resin); core / shell elastomers such as methyl methacrylate-acrylic rubber-styrene copolymer (MAS), and polyester-based elastomers; polyolefin resins such as cyclic cycloolefin resin (COP resin) and cyclic cycloolefin (COP) copolymer resin; polyamide resin (PA resin); polyimide resin (PI resin); polyetherimide resin (PEI resin); polyurethane resin (PU resin); polyphenylene ether resin (PPE resin); polyphenylene sulfide resin (PPS resin); polysulfone resin (PSU resin); polymethacrylate resin (PMMA resin); and polycaprolactone. The proportion of these components, i.e., components other than the above-mentioned polycarbonate resin and polyarylate resin, is preferably 0 to 50% by mass, and more preferably 0 to 20% by mass, of 100% by mass of the thermoplastic resin. Furthermore, the proportion of the total mass of the polycarbonate resin and polyarylate resin in 100% by mass of the thermoplastic resin is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, and particularly preferably 80 to 100% by mass. The thermoplastic resin preferably consists of only one or both of the polycarbonate resin and the polyarylate resin.

[0022] The proportion of thermoplastic resin in the continuous fiber reinforced thermoplastic resin sheet is preferably 15 to 50% by mass, more preferably 20 to 45% by mass, even more preferably 25 to 40% by mass, and particularly preferably 30 to 35% by mass, based on the total mass of the continuous fiber reinforced thermoplastic resin sheet. Thus, when the content of thermoplastic resin in the continuous fiber reinforced thermoplastic resin sheet is adjusted within an appropriate range, it is easy to suppress the amount of residual solvent that is not removed even by the solvent removal step described in detail below, and the properties such as elasticity and strength of the continuous fiber reinforced thermoplastic resin sheet can be maintained at a good level.

[0023] 1-2. Continuous Fibers Examples of continuous fibers used in the present invention include organic fibers such as carbon fibers, polyamide fibers such as nylon or aramid, and polyester fibers, and inorganic fibers such as glass fibers, with carbon fibers being preferred. Carbon fibers are derived from polyacrylonitrile (PAN) fibers or pitch fibers, and may be PAN-based carbon fibers made from PAN fibers or pitch-based hydrocarbons. The carbon content of the carbon fibers is preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably substantially 100% by mass.

[0024] The average fiber length of the continuous fibers is preferably 10 mm or more, more preferably 30 mm or more, and even more preferably 50 mm or more. Examples of the form of the continuous fibers include a single strand, a unidirectional sheet, a woven sheet, and a multiaxial laminate sheet. The number of single fibers contained in a fiber bundle (filament), the number of filaments contained in a filament bundle (tow), and their configurations can vary, and a wide variety of continuous fibers can be used in the present invention.

[0025] The proportion of continuous fibers in the continuous fiber reinforced thermoplastic resin sheet is preferably 50 to 85% by mass based on the total mass of the continuous fiber reinforced thermoplastic resin sheet, and from the viewpoint of the mechanical properties of the continuous fiber reinforced thermoplastic resin, it is more preferably 55 to 80% by mass, even more preferably 60 to 75% by mass, and particularly preferably 65 to 70% by mass.

[0026] The components other than the continuous fibers and thermoplastic resin in the continuous fiber reinforced thermoplastic resin sheet are preferably 0 to 20% by mass, more preferably 0 to 10% by mass, even more preferably 0 to 5% by mass, and particularly preferably 0 to 2% by mass, based on the total mass of the continuous fiber reinforced thermoplastic resin sheet. Furthermore, the proportion of the total mass of the continuous fibers and thermoplastic resin based on the total mass of the continuous fiber reinforced thermoplastic resin sheet is preferably 80 to 100% by mass, more preferably 90 to 100% by mass, even more preferably 95 to 100% by mass, and particularly preferably 98 to 100% by mass. The continuous fiber reinforced thermoplastic resin sheet preferably consists essentially of only continuous fibers and thermoplastic resin.

[0027] 1-3. Residual Organic Solvent The manufacturing process of a continuous fiber reinforced thermoplastic resin sheet, as described in detail below, includes an impregnation step in which the continuous fibers are impregnated with a solution in which a thermoplastic resin is dissolved in a halogen-containing organic solvent. Therefore, the continuous fiber reinforced thermoplastic resin sheet may contain a small amount of solvent such as a halogen-containing organic solvent. Thus, the content of the residual halogen-containing organic solvent that may be contained in the continuous fiber reinforced thermoplastic resin sheet is preferably 1000 mass ppm or less, more preferably 1000 mass ppm or less, more preferably 800 mass ppm or less, even more preferably 500 mass ppm or less, particularly preferably 200 mass ppm or less, and particularly preferably 150 mass ppm or less, 100 mass ppm or less, or less than 100 mass ppm. According to the manufacturing method of the present invention, the content of the residual halogen-containing organic solvent can be adjusted within the above-mentioned range in the continuous fiber reinforced thermoplastic resin sheet immediately after the solvent removal step or immediately after production, even if air drying has not been performed.

[0028] 1-4. Properties of Continuous Fiber Reinforced Thermoplastic Resin Sheet The thickness of the continuous fiber reinforced thermoplastic resin sheet of the present invention is not particularly limited, but is preferably 0.01 mm to 1 mm, more preferably 0.05 mm to 0.5 mm, and even more preferably 0.1 mm to 0.3 mm. The continuous fiber reinforced thermoplastic resin sheet of the present invention may be a single-layer sheet or a laminated sheet in which multiple sheets are directly laminated. In particular, a laminated sheet in which only multiple continuous fiber reinforced thermoplastic resin sheets are laminated is more preferable. Examples of a process for producing a laminated sheet by stacking the continuous fiber reinforced thermoplastic resin sheets of the present invention include a press molding process.

[0029] 2. Manufacturing Method of Continuous Fiber-Reinforced Thermoplastic Resin Sheet The manufacturing process of a continuous fiber-reinforced thermoplastic resin sheet includes an impregnation step of impregnating continuous fibers with a solution of a thermoplastic resin dissolved in a halogen-containing organic solvent, and a solvent removal step of removing the halogen-containing organic solvent from the continuous fibers by irradiating them with infrared rays. This solvent removal step allows the continuous fibers, which are an intermediate material for the continuous fiber-reinforced thermoplastic resin sheet and are impregnated with a solvent-containing thermoplastic resin, to be efficiently dried.

[0030] 2-1. Preparation of Thermoplastic Resin Solution (Solution Production Process) The method for producing a continuous fiber-reinforced thermoplastic resin sheet may include a solution production process. The thermoplastic resin solution is preferably prepared by a solution production process in which the above-mentioned thermoplastic resin or the like is dissolved in a halogen-containing organic solvent. The thermoplastic resin includes at least one of a polycarbonate resin and a polyarylate resin, but the production method of these resins is not particularly limited. For example, polycarbonate resins produced by various methods such as the phosgene method (interfacial polymerization method) and the melt transesterification method can be used. For example, a polycarbonate resin can be produced by an interfacial polymerization method under the following reaction conditions. That is, in the presence of dichloromethane and an alkaline aqueous solution, the pH is typically maintained at 10 or higher, and reaction raw materials including a dihydric phenol, a monohydric phenol as an end-capping agent, an antioxidant used to prevent oxidation of the dihydric phenol if necessary, and phosgene or triphosgene as a carbonate binder are mixed, and then a polymerization catalyst such as a tertiary amine or a quaternary ammonium salt is added to perform interfacial polymerization. The resulting resin solution is purified to obtain a polycarbonate resin solution. The timing of adding the terminal capping agent is not particularly limited as long as it is any time between the start of phosgenation and the start of polymerization. The reaction temperature is 0 to 35°C, and the reaction time is several minutes to several hours.

[0031] The concentration of the thermoplastic resin in the thermoplastic resin solution is preferably 10 to 30% by mass, more preferably 10 to 20% by mass or 12 to 25% by mass, and particularly preferably 10 to 18% by mass or 12 to 20% by mass, based on the total mass of the thermoplastic resin solution. If the concentration of the thermoplastic resin such as polycarbonate resin is within the above range, foaming during drying of the solvent in the next step can be prevented, and impregnation problems due to excessively high solution viscosity can also be prevented.

[0032] 2-2. Halogen-Containing Organic Solvent A variety of halogen-containing organic solvents can be used to form the thermoplastic resin solution. For example, halogen-containing organic solvents having a total carbon number of 3 or less, preferably 2 or less, and more preferably 1; those containing 3 or less, preferably 2 or less, halogen atoms per molecule; and those containing chlorine, fluorine, or iodine as the halogen, preferably chlorine or fluorine. Specific preferred examples of halogen-containing organic solvents include dichloromethane, chloromethane, trichloromethane, trichloroethylene, and tetrachloroethylene, with dichloromethane being more preferred as the halogen-containing organic solvent.

[0033] Furthermore, a solvent other than the halogen-containing organic solvent that is found to be compatible with the halogen-containing organic solvent may be contained in an amount of about 0 to 20 mass %, 0 to 10 mass %, 0 to 5 mass %, or 0 to 2 mass %, based on the mass of the entire solvent.

[0034] 2-3. Impregnation Step The impregnation step is a step in which a thermoplastic resin solution such as a polycarbonate resin solution is impregnated into a continuous fiber. The method of impregnation with the thermoplastic resin solution in the impregnation step is not particularly limited, and various methods can be used, such as a method in which the fiber is immersed in a tank containing the solution, a method in which the fiber is passed through a tank into which the solution has been sprayed, and a method in which the solution is sprayed onto the fiber. Among these, the method in which the continuous fiber is immersed in a tank containing the solution is preferred because it allows for the simplest and most uniform application of the solution.

[0035] In the impregnation step, the rate at which the thermoplastic resin solution is impregnated into the continuous fibers is preferably 0.3 m / min to 3.0 m / min, more preferably 0.3 m / min to 2.0 m / min or 0.3 m / min to 1.5 m / min, even more preferably 0.4 m / min to 2.0 m / min, 0.4 m / min to 1.5 m / min or 0.4 m / min to 1.2 m / min, and particularly preferably 0.5 m / min to 1.5 m / min or 0.5 m / min to 1.0 m / min. When the impregnation step is continued continuously for a relatively long time, it is preferable to impregnate the continuous fibers with the thermoplastic resin solution at a rate of, for example, about 1.0 m / min.

[0036] 2-4. Solvent Removal Step In the solvent removal step, the continuous fibers containing the thermoplastic resin solution, which are the intermediate material for the continuous fiber reinforced thermoplastic resin sheet, are dried using an infrared irradiation device, for example, a heater capable of irradiating infrared rays. The distance between the heater and the continuous fibers to be dried, i.e., the distance between the infrared irradiation surface of the heater and the surface of the continuous fibers to be dried, is preferably 100 mm or more and 410 mm or less. The distance between the heater and the continuous fibers to be dried is more preferably 150 mm or more and 380 mm or less, even more preferably 180 mm or more and 360 mm or less, and particularly preferably 200 mm or more and 320 mm or less, for example, 220 mm or more and 300 mm or less.

[0037] In the solvent removal step, the temperature of the heating element in the heater that radiates infrared rays is 260° C. or higher, and the temperature of the heating element is preferably 300° C. or higher and 400° C. or lower. The temperature of the heating element of the heater that radiates infrared rays is more preferably 325° C. or higher and 375° C. or lower, approximately 350° C. In addition, in the solvent removal step, it is preferable to use a heater that radiates far infrared rays including a wavelength range of 2 μm to 20 μm, and the heater is more preferably capable of radiating infrared rays including a wavelength range of 3 μm to 15 μm, and even more preferably capable of radiating infrared rays including a wavelength range of 5 μm to 12 μm. Furthermore, in the solvent removal step, it is preferable to use far-infrared rays having a peak wavelength of 2.0 μm to 6.0 μm, more preferably a far-infrared ray having a peak wavelength of 2.5 μm to 5.5 μm, even more preferably a far-infrared ray having a peak wavelength of 3.0 μm to 5.2 μm, and particularly preferably a far-infrared ray having a peak wavelength of 3.5 μm to 5.0 μm or 4.0 μm to 4.9 μm. Note that the above-mentioned peak wavelength value is the value immediately after irradiation from the infrared irradiation surface of the heater, and although the infrared wavelength may vary depending on the distance between the heater and the continuous fiber to be dried, irradiating infrared rays having a wavelength region or peak wavelength within the above-mentioned range at a distance within the above-mentioned range can make solvent removal more efficient.

[0038] In the solvent removal step, the infrared irradiation time is preferably 2 to 15 minutes, more preferably 3 to 12 minutes, even more preferably 3 to 6 minutes or 4 to 10 minutes, and particularly preferably 5 to 6 minutes.

[0039] In the solvent removal step, the area of ​​the infrared ray irradiated surface of the heater is preferably 10% or more, more preferably 20% or more, and particularly preferably 30% or more, of the area of ​​the surface of the continuous fiber to be dried. The above-mentioned area ratio value, i.e., the ratio of the area of ​​the infrared ray irradiated surface of the heater to the area of ​​the surface of the continuous fiber to be dried (area of ​​the surface to be dried (m ２ ) / area of ​​infrared irradiation surface (m ２ ) × 100(%)) is more preferably 35% or more. The upper limit of the area ratio is not particularly important, and may be, for example, 80%, 70%, 60%, or 50%. In the solvent removal step, the maximum energy density of the heater is 20 to 200 kW / m ２ It is preferable that the power consumption is about 30 to 150 kW / m ２ Or 35 to 120 kW / m ２ More preferably, it is 45 to 120 kW / m ２ Or 50 to 150 kW / m ２ It is more preferable that the maximum energy density of the heater is 40 to 100 kW / m ２ Or 45 to 80 kW / m ２ may be.

[0040] 2-5. Measurement step In the method for producing a continuous fiber reinforced thermoplastic resin sheet, it is preferable to further include a measurement step of measuring the content of residual halogen-containing organic solvent in the continuous fiber reinforced thermoplastic resin sheet after the solvent removal step. As described above, it is preferable that the content of residual halogen-containing organic solvent in the continuous fiber reinforced thermoplastic resin sheet is low, so it is possible to confirm whether a continuous fiber reinforced thermoplastic resin sheet with the desired properties has been produced by the measurement step.

[0041] 2-6. Comparison step In the method for producing a continuous fiber reinforced thermoplastic resin sheet, it is preferable to further include a comparison step in which the content of residual halogen-containing organic solvent in the continuous fiber reinforced thermoplastic resin sheet is compared with a predetermined threshold value after the solvent removal step. As described above, in order to suppress the content of residual halogen-containing organic solvent in the continuous fiber reinforced thermoplastic resin sheet, a predetermined reference value, mainly an upper limit value (for example, the above-mentioned 1000 mass ppm, etc.) is set as a threshold value, and by comparing it with the actual content of residual halogen-containing organic solvent, it can be confirmed whether a continuous fiber reinforced thermoplastic resin sheet with the desired properties has been produced.

[0042] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0043] <Resin Mass Content> The resin mass content in the carbon fiber reinforced resin prepregs obtained in the examples and comparative examples described below was calculated based on the fiber mass content determined in accordance with JIS K 7075. That is, the resin mass content was determined as the value (mass%) obtained by subtracting the fiber mass content (mass%) in the carbon fiber reinforced resin prepreg from 100(%).

[0044] <Residual dichloromethane content (ppm)> The carbon fiber reinforced resin prepreg obtained in the examples and comparative examples described below was cut to a size of 6.0 cm x 4.0 cm and dissolved in 20 milliliters of chloroform to extract the dichloromethane content in the sample. After extraction, the sample was filtered using a 0.45 μm filter (RJF3245NH) to obtain a sample for gas chromatography. GC analysis was performed under the following conditions, the peak area at a retention time of 4.7 minutes was determined, and the dichloromethane content was calculated using a calibration curve. Measurement equipment: Gas chromatograph (Shimadzu Corporation GC-2014) Solvent: Chloroform Sample vaporizer: 200°C, 252 kPa Column temperature and time: 60°C at the start of measurement, 120°C at the end of measurement, measurement time: 10 minutes Detector temperature: 320°C

[0045] Production Example 1: Production Example of Polycarbonate Resin (PC-1) 6.5 kg (28.47 mol) of bisphenol A (BPA) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. and 30 g of hydrosulfite as an antioxidant were added and dissolved in 40 kg of a 9% by mass (w / w%) aqueous sodium hydroxide solution. 17 kg of dichloromethane was added to the resulting solution, and while stirring, 3.7 kg of phosgene was blown in over 30 minutes while maintaining the solution temperature in the range of 15°C to 25°C. After the phosgene blow-in was completed, a solution prepared by dissolving 3 kg of a 9% by mass aqueous sodium hydroxide solution, 16 kg of dichloromethane, and 167.7 g (1.12 mol) of p-tert-butylphenol in 1 kg of dichloromethane was added to the reaction solution and emulsified with vigorous stirring. 10 ml of triethylamine was then added as a polymerization catalyst to the reaction solution, and the polymerization reaction was carried out for approximately 40 minutes. The resulting polymerization solution was separated into an aqueous phase and an organic phase, and the organic phase was neutralized with phosphoric acid. The organic phase was then repeatedly washed with pure water until the pH of the washings became neutral. The resulting polymer solution was added dropwise to warm water maintained at 47°C, and the solvent was evaporated to obtain a white powdery precipitate. The resulting precipitate was filtered and dried at 105°C for 24 hours to obtain a polycarbonate resin (PC-1). The resulting polycarbonate resin (PC-1) was used in the following examples and comparative examples. The viscosity average molecular weight of the resulting polycarbonate resin (PC-1) was measured and found to be 21,500.

[0046] <Production Example 2: Production Example of Polycarbonate Resin (PC-2)> 6.7 kg (23.10 mol) of 1,1-bis(4-hydroxyphenyl)-1-phenylethane (BPAP) manufactured by Honshu Chemical Industry Co., Ltd. and 40 g of hydrosulfite as an antioxidant were added and dissolved in 36 kg of a 9 wt % aqueous sodium hydroxide solution. 16 kg of dichloromethane was added to the resulting solution, and while stirring, 3.2 kg of phosgene was blown in over 30 minutes while maintaining the solution temperature in the range of 15°C to 25°C. After the phosgene blow-in was completed, a solution prepared by dissolving 13 kg of dichloromethane and 132.8 g (0.89 mol) of p-tert-butylphenol in 1 kg of dichloromethane was added to the reaction solution and emulsified with vigorous stirring. 15 ml of triethylamine was then added as a polymerization catalyst to the reaction solution, and the polymerization reaction was carried out for approximately 40 minutes. The resulting polymerization solution was separated into an aqueous phase and an organic phase, and the organic phase was neutralized with phosphoric acid. The organic phase was then repeatedly washed with pure water until the pH of the washings became neutral. The resulting polymer solution was added dropwise to warm water maintained at 60°C, and the solvent was evaporated to obtain a white powdery precipitate. The resulting precipitate was filtered and dried at 120°C for 24 hours to obtain a polycarbonate resin (PC-2). The resulting polycarbonate resin (PC-2) was used in the following examples and comparative examples. The viscosity average molecular weight of the resulting polycarbonate resin (PC-2) was measured and found to be 21,000.

[0047] <Method for Measuring Viscosity Average Molecular Weight> The viscosity average molecular weight (Mv) was measured and calculated as follows: Measuring instrument: Ubbelohde capillary viscometer Solvent: dichloromethane Resin solution concentration: 0.5 g / dL Measurement temperature: 25°C Measurement was performed under the above conditions, and the intrinsic viscosity [η] / dL was determined with a Huggins constant of 0.45, and calculated using the following formula (1): η = 1.23 × 10 －４ ×Mv ０．８３ ...(1)

[0048] Example 1 A polycarbonate resin solution was prepared by dissolving 15 parts by mass of polycarbonate resin (PC-1) in 85 parts by mass of dichloromethane. A 2 / 2 twill carbon fiber fabric (Toray Industries, Inc., Torayca® Cloth CO6347B) made of continuous carbon fibers derived from polyacrylonitrile was cut into a size of 6.0 cm x 16.0 cm (thickness: 0.22 mm; weight: 198 g / m). ２ )) and impregnated with a polycarbonate resin solution at a lifting speed of 0.6 m / min using a dip coater. After impregnation, both surfaces of the prepreg intermediate material (prepreg base material), which is a carbon fiber fabric, were dried for 5 minutes using a pair of far-infrared heater panels (Far Infrared Electric Ceramic Heater PLC (PLC-328) manufactured by Noritake Co., Ltd.) facing each other to obtain a carbon fiber reinforced thermoplastic resin prepreg. The far-infrared heater was surrounded by an aluminum plate, and the solvent removal process was carried out with the distance between the heater panel and the prepreg base material and the heater temperature as shown in Table 1. In addition, in the solvent removal process, the area of ​​the infrared irradiated surface of one far-infrared heater panel was 0.0144 m ２ The area was 12 cm x 12 cm, and four far-infrared heater panels were used to face the front and back sides of two prepreg intermediate materials arranged side by side along approximately the same plane. The impregnated areas of the two prepreg intermediate materials, i.e., the surfaces to be dried from which the solvent was removed, were 0.0060 m². ２ (10 cm x 6 cm). Therefore, the ratio of the area of ​​the surface of the heater panel irradiated with far-infrared rays to the area of ​​the surface of the continuous fiber to be dried (area of ​​the surface to be dried (m ２ ) / area of ​​far-infrared irradiation surface (m ２ ) × 100(%)) was approximately 41.7%.

[0049] The electric capacity of the far-infrared heater panel is 800 W, and the area of ​​the infrared radiation surface is 0.0144 m as described above. ２ Therefore, the maximum energy density was 55.6 kW / m ２ (0.8kW / 0.0144m ２ ) was calculated.

[0050] As described above, in Example 1, a pair of far-infrared heater panels was used, and the prepreg base material was placed at the midpoint between the pair of far-infrared heater panels. Therefore, the value in the "Distance between heater and prepreg base material" column in Table 1 refers to the distance between the surface of the prepreg base material (the surface to be dried) and one of the far-infrared heater panels, and this is the same in Table 2 as in Table 1. Furthermore, the value in the "Infrared heater temperature" column in Table 1 refers to the temperature of the heating element emitting infrared rays in the heater, and this is the same in Table 2 as in Table 1. As shown in the table below, the infrared heater temperature in the example was 300 to 400°C, and the peak wavelength of the irradiated far-infrared rays calculated from Wien's displacement law for the far-infrared heater panel used was approximately 4.96 to 4.21 μm. Furthermore, the infrared heater temperature in the comparative example was 250 to 300°C, and the peak wavelength of the irradiated far-infrared rays was approximately 5.43 to 4.96 μm.

[0051] The resin mass content of the obtained carbon fiber reinforced resin prepreg (continuous fiber reinforced thermoplastic resin sheet) was 33 mass%, and the dichloromethane content in the prepreg was measured and found to be 100 mass ppm. The evaluation results are shown in Table 1.

[0052] Examples 2 to 14, Examples 1-1 to 1-7, Comparative Examples 1 to 4 Carbon fiber reinforced resin prepregs were produced and evaluated in the same manner as in Example 1, except that any one of the type of polycarbonate resin, the distance between the heater panel and the prepreg base material, and the heater temperature was changed as shown in Table 1. The evaluation results are shown in Table 1 or Table 2. The results of Examples 1-1 to 1-7 are shown in Table 2, along with the results of the above-mentioned Example 1, which is included in both Examples 1 and 2.

[0053] <Comparative Example 5> Impregnation with a polycarbonate resin solution was carried out in the same manner as in Example 1. After impregnation, the prepreg was dried for 5 minutes in a multi-shelf hot air dryer to obtain a carbon fiber reinforced resin prepreg. The evaluation results are shown in Table 1.

[0054] As is clear from the results of the Examples and Comparative Examples shown in Table 1, it was confirmed that infrared irradiation can efficiently remove solvent from intermediate materials (prepreg intermediate materials and prepreg base materials) that are continuous fibers containing a halogen-containing organic solvent (see Example and Comparative Example 5). Furthermore, in Examples in which various conditions in the solvent removal step, such as the distance between the heater irradiating infrared rays and the surface of the continuous fibers to be dried, the infrared heater temperature, and the drying time, were adjusted, it was confirmed that drying of the continuous fibers was carried out more efficiently, and that adjusting various conditions in the impregnation step, which is the step prior to the solvent removal step, such as the concentration of the resin solution and the impregnation rate, also made drying of the continuous fibers more efficient (see Tables 1 and 2).

[0055] Furthermore, it was confirmed that the solvent was efficiently removed not only in the example using the bisphenol-based polycarbonate resin (PC-1) but also in the example using the bisphenol AP-based polycarbonate resin (PC-2), which is usually not easy to dry.

Claims

1. an impregnation step of impregnating continuous fibers with a thermoplastic resin solution containing a thermoplastic resin including at least one of a polycarbonate resin and a polyarylate resin and a halogen-containing organic solvent; a solvent removal step of removing the halogen-containing organic solvent from the continuous fibers impregnated with the thermoplastic resin solution by irradiating the fibers with infrared rays; A method for producing a continuous fiber reinforced thermoplastic resin sheet, comprising: In the solvent removal step, the distance between the heater that irradiates the infrared rays and the continuous fibers is 400 mm or less, And the temperature of the heating element radiating infrared rays in the heater is 260 ° C. or higher.

2. The method for producing a continuous fiber reinforced thermoplastic resin sheet according to claim 1, wherein the halogen-containing organic solvent includes dichloromethane.

3. The method for producing a continuous fiber reinforced thermoplastic resin sheet according to claim 1 or 2, wherein in the solvent removal step, a distance between the heater and the continuous fibers is 100 mm or more and 410 mm or less.

4. The method for producing a continuous fiber reinforced thermoplastic resin sheet according to claim 1 or 2, wherein in the solvent removal step, the temperature of the heating element in the heater is 300 ° C. or higher and 400 ° C. or lower.

5. The method for producing a continuous fiber reinforced thermoplastic resin sheet according to claim 1 or 2, wherein in the solvent removal step, the heater irradiates far infrared rays including a wavelength range of 2 μm to 20 μm.

6. The method for producing a continuous fiber reinforced thermoplastic resin sheet according to claim 1 or 2, wherein the concentration of the thermoplastic resin in the thermoplastic resin solution is 10 to 30% by mass.

7. 3. The method for producing a continuous fiber reinforced thermoplastic resin sheet according to claim 1 or 2, wherein in the impregnation step, the rate at which the thermoplastic resin solution is impregnated into the continuous fibers is 0.3 m / min to 3.0 m / min.

8. The method for producing a continuous fiber reinforced thermoplastic resin sheet according to claim 1 or 2, wherein the infrared irradiation time in the solvent removal step is 2 minutes to 15 minutes.

9. The method for producing a continuous fiber reinforced thermoplastic resin sheet according to claim 1 or 2, wherein the proportion of the thermoplastic resin in the continuous fiber reinforced thermoplastic resin sheet is 15 to 50% by mass.

10. The method for producing a continuous fiber reinforced thermoplastic resin sheet according to claim 1 or 2, wherein the content of residual halogen-containing organic solvent in the continuous fiber reinforced thermoplastic resin sheet is less than 1000 ppm by mass.

11. The method for producing a continuous fiber-reinforced thermoplastic resin sheet according to claim 1 or 2, wherein the thermoplastic resin has a structural unit derived from a dihydric phenol represented by the following general formula (1): 【Chemical Formula 1】 (In general formula (1), R １ ~R ４ each independently represent hydrogen, halogen, a nitro group, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 5 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, an aralkyl group having 7 to 17 carbon atoms which may have a substituent, or an alkenyl group having 2 to 15 carbon atoms which may have a substituent; X is -O-, -S-, -SO-, -SO ２ -, -CO-, or a divalent group represented by any one of the following formulas (2) to (5): 【Chemistry 2】 (In formula (2), R ５ and R ６ each independently represents hydrogen, halogen, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 5 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, an aralkyl group having 7 to 17 carbon atoms which may have a substituent, or an alkenyl group having 2 to 15 carbon atoms which may have a substituent, or R ５ and R ６ are bonded to each other to form a carbocyclic ring having 3 to 20 carbon atoms or a heterocyclic ring having 1 to 20 carbon atoms; c represents an integer of 0 to 20. (In formula (3), R ７ and R ８ each independently represents hydrogen, halogen, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 5 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, an aralkyl group having 7 to 17 carbon atoms which may have a substituent, or an alkenyl group having 2 to 15 carbon atoms which may have a substituent, or R ７ and R ８ are bonded to each other to form a carbocyclic ring having 3 to 20 carbon atoms or a heterocyclic ring having 1 to 20 carbon atoms. (In formula (4), R ９ ~R １２ each independently represents hydrogen, halogen, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 5 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, an aralkyl group having 7 to 17 carbon atoms which may have a substituent, or an alkenyl group having 2 to 15 carbon atoms which may have a substituent, the substituents are each independently a halogen, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 12 carbon atoms; R ９ and R １０ and R １１ and R １２ may be bonded to each other to form a carbocyclic ring having 3 to 20 carbon atoms or a heterocyclic ring having 1 to 20 carbon atoms. (In formula (5), R １３ ~R ２２ each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; R １３ ~R ２２ At least one of the groups is an alkyl group having 1 to 3 carbon atoms.

12. The method for producing a continuous fiber-reinforced thermoplastic resin sheet according to claim 1 or 2, further comprising a solution producing step of dissolving the thermoplastic resin in the halogen-containing organic solvent to produce a thermoplastic resin solution.

13. The method for producing a continuous fiber reinforced thermoplastic resin sheet according to claim 1 or 2, further comprising a measuring step of measuring the content of residual halogen-containing organic solvent in the continuous fiber reinforced thermoplastic resin sheet after the solvent removal step.

14. 3. The method for producing a continuous fiber reinforced thermoplastic resin sheet according to claim 1 or 2, further comprising a comparison step of comparing the content of the residual halogen-containing organic solvent in the continuous fiber reinforced thermoplastic resin sheet with a predetermined threshold value after the solvent removal step.

15. The method for producing a continuous fiber reinforced thermoplastic resin sheet according to claim 1 or 2, wherein the continuous fibers are in the form of a single strand, a unidirectional sheet, or a woven fabric.

16. The method for producing a continuous fiber-reinforced thermoplastic resin sheet according to claim 1 or 2, wherein the continuous fibers are any of carbon fibers, glass fibers, and aramid fibers.

17. The method for producing a continuous fiber reinforced thermoplastic resin sheet according to claim 1 or 2, wherein the continuous fiber reinforced thermoplastic resin sheet is a prepreg.

Images