Method for manufacturing a shaped body, resin impregnation device and 3D printer

Abstract

A method for manufacturing a molded body formed of a fiber-reinforced composite material containing a cured product of a thermosetting resin or a thermosetting resin composition and containing continuous reinforcing fibers, a resin impregnation device suitable for use in the manufacturing method, and a 3D printer, the manufacturing method sequentially comprising the following processes (I) to (III). Process (I): a coating process in which a thermosetting resin or a thermosetting resin composition is coated on the surface of a continuous reinforcing fiber bundle; Process (II): a resin impregnation process in which the aforementioned continuous reinforcing fiber bundle is twisted after process (I) to obtain a prepreg in which the aforementioned thermosetting resin or thermosetting resin composition is impregnated; and Process (III): a heat molding process in which the aforementioned prepreg obtained in process (II) is disposed and then heated.

Description

Technical Field

[0001] This invention relates to a method for manufacturing molded articles formed from fiber-reinforced composite materials, a resin impregnation apparatus, and a 3D printer. Background Technology

[0002] In recent years, there has been a growing trend towards environmentally friendly CNG vehicles and fuel cell vehicles (FCVs). Fuel cell vehicles use fuel cells as their power source, and the equipment needed to compress hydrogen gas into high pressure and fill the vehicle with hydrogen is essential.

[0003] High-pressure gas storage tanks, used as onboard fuel tanks for hydrogen refueling stations in fuel cell vehicles, CNG vehicles, and other fuel cell vehicles, have traditionally been made of steel. However, there is a growing trend towards developing lighter high-pressure gas storage tanks that incorporate resin materials in the tank lining or outer layer. This lightweighting of onboard fuel tanks offers advantages such as improved fuel efficiency in the vehicle.

[0004] Fiber-reinforced plastics (FRPs) and other fiber-reinforced composites possess very high elastic modulus, strength, and lightweight properties, making them a highly sought-after alternative to metals. Increased demand for FRPs in automotive structural materials, wind turbine blades, pressure vessels, and aerospace applications is anticipated.

[0005] When FRP (fiber-reinforced plastic) using cured thermosetting resins such as epoxy resin as the base resin is used for pressure vessel applications, it is known to be molded by fiber winding. For example, reinforcing fiber yarns (tow prepreg) impregnated with thermosetting resin compositions such as epoxy resin compositions can be wound around the outer surface of a metal or resin gasket to cover it, and then the composition can be cured and molded.

[0006] However, in the above methods, a liner or core material, which is used as a mold for winding the reinforcing fiber yarn, is required. Therefore, it is difficult to manufacture a pressure vessel without a liner made of only FRP.

[0007] On the other hand, as a method for creating three-dimensional models using a prepreg impregnated with a thermosetting resin composition without the use of a mold, a method using a 3D printer was also investigated.

[0008] For example, Patent Document 1 discloses a three-dimensional modeling system equipped with a nozzle and a robotic arm. The nozzle has a supply section for supplying a continuous material comprising resin and fiber, and the robotic arm protects a molding section that receives the continuous material from the supply section and shapes a three-dimensional model, allowing the molding section to move and rotate, and its position and orientation relative to the supply section to be freely changed. Furthermore, it discloses that the nozzle, having a supply section for supplying a continuous material comprising resin and fiber, includes a resin impregnation device for impregnating thermosetting resin into the fiber, and that the resin impregnation device includes a resin tank for storing the resin.

[0009] Existing technical documents

[0010] Patent documents

[0011] Patent Document 1: Japanese Patent Application Publication No. 2019-48398 Summary of the Invention

[0012] The problem the invention aims to solve

[0013] Similar to Patent Document 1, the conventional fiber winding method also employs the following approach: impregnating the reinforcing fiber yarn with a resin tank containing a thermosetting resin or a thermosetting resin composition (hereinafter also referred to as "thermosetting resin or composition") by immersing it in the thermosetting resin.

[0014] However, in the above methods, thermosetting resins or compositions with short pot life will cure during the pre-molding stage, such as while stored in the resin tank, thus making them unusable.

[0015] On the other hand, if a method other than impregnation is used to impregnate the reinforcing fiber yarn with thermosetting resin or composition, insufficient impregnation of the thermosetting resin or composition with the reinforcing fiber yarn may result in problems such as a decrease in the physical properties of the obtained FRP.

[0016] The objective of this invention is to provide a manufacturing method in which a thermosetting resin or thermosetting resin composition with a short pot life can be used in the manufacture of a molded article formed from a cured product comprising a thermosetting resin or a thermosetting resin composition and comprising continuous reinforcing fibers, and the thermosetting resin or thermosetting resin composition exhibits good impregnation in the continuous reinforcing fiber bundles; a resin impregnation apparatus and a 3D printer suitable for use in this manufacturing method.

[0017] Solution for solving the problem

[0018] The inventors have discovered that a manufacturing method comprising a coating step (I) of coating a thermosetting resin or composition onto the surface of a continuous reinforcing fiber bundle, a resin impregnation step (II) of twisting the continuous reinforcing fiber bundle after step (I) to obtain a prepreg impregnated with a thermosetting resin or composition, and a thermoforming step (III) of preparing the prepreg and then heating it, as well as a resin impregnation apparatus and a 3D printer with a defined mechanism suitable for use in the manufacturing method, can solve the above-mentioned problems.

[0019] That is, the present invention relates to the following [1] to [3].

[0020] [1] A method for manufacturing a molded body, the molded body being formed from a fiber-reinforced composite material comprising a cured product of a thermosetting resin or a thermosetting resin composition and comprising continuous reinforcing fibers, the manufacturing method comprising the following steps (I) to (III) in sequence.

[0021] Process (I): Coating process, in which a thermosetting resin or a thermosetting resin composition is coated on the surface of a continuous reinforcing fiber bundle;

[0022] Step (II): Resin impregnation step, after step (I), the aforementioned continuous reinforcing fiber bundle is twisted to obtain a prepreg impregnated with the aforementioned thermosetting resin or thermosetting resin composition.

[0023] Step (III): Heating and molding process, in which the prepreg obtained in step (II) is prepared and then heated.

[0024] [2] A resin impregnation apparatus comprising: a mechanism for discharging a continuous reinforcing fiber bundle; a nozzle for spraying a thermosetting resin or a thermosetting resin composition onto the surface of the continuous reinforcing fiber bundle; and a mechanism for twisting the continuous reinforcing fiber bundle.

[0025] [3] A 3D printer equipped with the resin impregnation device described in [2] above.

[0026] The effects of the invention

[0027] According to the present invention, a manufacturing method is provided that enables the use of thermosetting resins or compositions with short pot life in the manufacture of molded articles formed from cured thermosetting resins or compositions and containing continuous reinforcing fibers, and that improves the impregnation of thermosetting resins or compositions in continuous reinforcing fiber bundles; a resin impregnation apparatus and a 3D printer are suitable for use in the manufacturing method.

[0028] According to the manufacturing method of the present invention, a pressure vessel without a liner can be easily manufactured. This pressure vessel is suitable as a high-pressure gas storage tank for vehicle use and is lightweight, thus improving fuel efficiency in the vehicle. Attached Figure Description

[0029] Figure 1 This is a schematic diagram illustrating one embodiment of the twisting process in step (II).

[0030] Figure 2 This is a cross-sectional schematic diagram illustrating one embodiment of a pressure vessel without a liner.

[0031] Figure 3 This is a schematic diagram illustrating one embodiment of the resin impregnation apparatus of the present invention and a 3D printer equipped with it. Detailed Implementation

[0032] [Manufacturing method of molded body]

[0033] The method for manufacturing a molded body of the present invention (hereinafter also referred to as "the manufacturing method of the present invention") is a method for manufacturing a molded body, wherein the method comprises the following steps (I) to (III) in sequence, and the molded body is formed from a fiber-reinforced composite material comprising a cured product of a thermosetting resin or a thermosetting resin composition and comprising continuous reinforcing fibers.

[0034] Process (I): Coating process, in which a thermosetting resin or a thermosetting resin composition is coated on the surface of a continuous reinforcing fiber bundle.

[0035] Step (II): Resin impregnation step, after step (I), the aforementioned continuous reinforcing fiber bundle is twisted to obtain a prepreg impregnated with the aforementioned thermosetting resin or thermosetting resin composition.

[0036] Step (III): Heating and molding process, in which the prepreg obtained in step (II) is prepared and then heated.

[0037] In this specification, thermosetting resin refers to a resin that can be heat-cured alone, and thermosetting resin composition refers to a thermosetting composition containing two or more resin components. Typically, a two-component thermosetting resin composition containing a main agent (A) and a curing agent (B) can be listed as a thermosetting resin composition.

[0038] According to the manufacturing method of the present invention, in the manufacture of a molded article formed from a cured product comprising a thermosetting resin or a thermosetting resin composition and comprising continuous reinforcing fibers, it is possible to use a thermosetting resin or composition with a short pot life, and the impregnation of the thermosetting resin or composition in the continuous reinforcing fiber bundles becomes good. The reason for this is not yet certain, but it can be speculated as follows.

[0039] In the manufacturing method of the present invention, step (I) is performed to coat the surface of a continuous reinforcing fiber bundle with a thermosetting resin or a thermosetting resin composition (coating step). Conventionally, a method for impregnating a continuous reinforcing fiber bundle with a thermosetting resin, which serves as a precursor for the base resin, involves immersing the continuous reinforcing fiber bundle in a thermosetting resin bath. However, this method suffers from the problem that the thermosetting resin bath can cure during the manufacturing process. However, by performing step (I) in the present invention, resin curing during the manufacturing process can be avoided even when using a thermosetting resin or composition with a short shelf life. Furthermore, when, for example, a two-component thermosetting resin composition is used, the main agent (A) or a composition containing it, and the curing agent (B) or a composition containing it can be coated separately in the coating step without pre-mixing them. From this perspective, it is also easy to apply thermosetting resin compositions with short shelf lives in the manufacturing method of the present invention.

[0040] In step (II) of the manufacturing method of the present invention, by performing a twisting operation on the continuous reinforcing fiber bundle coated with a thermosetting resin or composition in step (I), the thermosetting resin or composition is allowed to flow, thereby promoting its impregnation within the continuous reinforcing fiber bundle. Furthermore, when using a two-component thermosetting resin composition, even if the main agent (A) or a composition containing it and the curing agent (B) or a composition containing it are separately coated onto the surface of the continuous reinforcing fiber bundle in step (I), the main agent (A) and the curing agent (B) can be sufficiently mixed within the continuous reinforcing fiber bundle through step (II). As a result, it can be considered that the decrease in the Tg of the cured product caused by insufficient mixing of the main agent (A) and the curing agent (B) can also be suppressed.

[0041] <Process (I): Coating Process>

[0042] In step (I), a thermosetting resin or a thermosetting resin composition is coated onto the surface of the continuous reinforcing fiber bundle. By performing step (I), even when using a thermosetting resin or composition with a short pot life, adverse conditions such as curing of the thermosetting resin or composition before molding will not occur, thus enabling the manufacture of fiber-reinforced composite materials and molded articles.

[0043] (Thermosetting resins, thermosetting resin compositions)

[0044] The thermosetting resin used in this invention is not particularly limited as long as it is a resin that can be cured by heating. Furthermore, the thermosetting resin composition used in this invention is a composition containing such a thermosetting resin.

[0045] As thermosetting resins, examples include at least one selected from the group consisting of epoxy resins, phenolic resins, unsaturated polyester resins, urea resins, melamine resins, unsaturated polyimide resins, cyanate ester resins, silicone resins, urethane resins, casein resins, furan resins, alkyd resins, and xylene resins.

[0046] Furthermore, examples of two-component thermosetting resin compositions containing a main component (A) and a curing agent (B) include epoxy resin compositions in which the main component (A) is an epoxy resin and the curing agent (B) is an epoxy resin curing agent, and urethane resin compositions in which the main component (A) is a polyol and the curing agent (B) is a polyisocyanate. From the viewpoint of ease of impregnation in continuously reinforcing fiber bundles and the viewpoint of heat resistance, strength, and gas barrier properties such as hydrogen in the resulting cured product, two-component epoxy resin compositions in which the main component (A) is an epoxy resin and the curing agent (B) is an epoxy resin curing agent are preferred.

[0047] Among the above-described epoxy resin compositions, a more preferred epoxy resin composition is one in which the main agent (A) is epoxy resin (A1) and the curing agent (B) is epoxy resin curing agent (B1), wherein the epoxy resin curing agent (B1) comprises the reaction product (X) of the following components (x1) and (x2). This epoxy resin composition can achieve higher gas barrier properties and impact resistance, and is therefore suitable for manufacturing pressure vessels described later.

[0048] (x1) Select at least one from the group consisting of m-phenylenediamine and p-phenylenediamine;

[0049] (x2) is selected from at least one of the groups consisting of unsaturated carboxylic acids and their derivatives as shown in the following general formula (1).

[0050]

[0051] (In equation (1), R) 1 R 2 Each of these can independently represent a hydrogen atom, an alkyl group with 1 to 8 carbon atoms, an aryl group with 6 to 12 carbon atoms, or an aralkyl group with 7 to 13 carbon atoms.

[0052] The cured epoxy resin composition exhibits high gas barrier properties. For example, the hydrogen permeability coefficient of the cured composition is preferably set to 8.0 × 10⁻⁶. -11 [cc·cm / (cm 2 ·s·cmHg)] or less, more preferably set to 6.0×10 -11 [cc·cm / (cm 2 The value of ·s·cmHg)] is further preferably set to 4.5×10 -11 [cc·cm / (cm 2 ·s·cmHg)] below.

[0053] The hydrogen permeability coefficient of the cured epoxy resin composition described above can be determined by the method described in the examples under drying conditions at 23°C.

[0054] [Epoxy Resin (A1)]

[0055] The epoxy resin (A1) used as the main agent (A) (hereinafter also referred to as "component (A1)") is not particularly limited as long as it is a multifunctional epoxy resin having two or more epoxy groups. However, considering the high gas barrier properties, it is preferred to be a multifunctional epoxy resin containing an aromatic ring or alicyclic structure within the molecule.

[0056] Specific examples of this multifunctional epoxy resin include at least one resin selected from the following: epoxy resins derived from m-phenylenediamine having glycidyl amino groups; epoxy resins derived from p-phenylenediamine having glycidyl amino groups; epoxy resins derived from 1,3-bis(aminomethyl)cyclohexane having glycidyl amino groups; epoxy resins derived from 1,4-bis(aminomethyl)cyclohexane having glycidyl amino groups; epoxy resins derived from diaminodiphenylmethane having glycidyl amino groups; epoxy resins derived from p-aminophenol having glycidyl amino and / or glycidyloxy groups; epoxy resins derived from bisphenol A having glycidyloxy groups; epoxy resins derived from bisphenol F having glycidyloxy groups; epoxy resins derived from phenolic varnish having glycidyloxy groups; and epoxy resins derived from resorcinol having glycidyloxy groups. To improve various properties such as flexibility, impact resistance, and resistance to damp heat, two or more of the above-mentioned epoxy resins can be mixed in an appropriate proportion.

[0057] Of the above, from the viewpoint of gas barrier properties, the epoxy resin (A1) is preferably selected as at least one of the following as the main component: epoxy resin with glycidyl amino group derived from m-phenylenediamine, epoxy resin with glycidyl amino group derived from p-phenylenediamine, epoxy resin with glycidyl oxy group derived from bisphenol A, and epoxy resin with glycidyl oxy group derived from bisphenol F. From the viewpoint of exhibiting high hydrogen barrier properties, the epoxy resin with glycidyl amino group derived from m-phenylenediamine is more preferably selected as the main component.

[0058] It should be noted that the term "main component" as used herein refers to the inclusion of other components within the scope of the present invention, preferably 50-100% by mass, more preferably 70-100% by mass, and even more preferably 90-100% by mass.

[0059] [Epoxy resin curing agent (B1)]

[0060] From the viewpoint of exhibiting high gas barrier properties and impact resistance, epoxy resin curing agent (B1) (hereinafter also referred to as "component (B1)") contains the reaction product (X) of the following components (x1) and components (x2).

[0061] (x1) Select at least one from the group consisting of m-phenylenediamine and p-phenylenediamine;

[0062] (x2) is selected from at least one of the groups consisting of unsaturated carboxylic acids and their derivatives as shown in the following general formula (1).

[0063]

[0064] (In equation (1), R) 1 R 2 Each of these can independently represent a hydrogen atom, an alkyl group with 1 to 8 carbon atoms, an aryl group with 6 to 12 carbon atoms, or an aralkyl group with 7 to 13 carbon atoms.

[0065] [Reaction product (X)]

[0066] The reaction product (X) is the reaction product of the aforementioned components (x1) and (x2).

[0067] From the viewpoint of gas barrier properties, component (x1) is used, and from the viewpoint of gas barrier properties, m-phenylenediamine is preferred. Component (x1) can be used alone or in combination of two.

[0068] Component (x2) is at least one selected from the group consisting of unsaturated carboxylic acids and their derivatives represented by the aforementioned general formula (1). From the viewpoint of exhibiting high gas barrier properties and impact resistance, R in the aforementioned general formula (1) 1 Preferably, it is an alkyl group having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, even more preferably an alkyl group having 1 to 3 carbon atoms, and even more preferably an alkyl group having 1 to 3 carbon atoms.

[0069] Furthermore, from the viewpoint of exhibiting high air barrier properties and impact resistance, R in the aforementioned general formula (1) 2 Preferably, it is an alkyl group having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, even more preferably an alkyl group having 1 to 3 carbon atoms, and even more preferably an alkyl group having 1 to 3 carbon atoms.

[0070] As derivatives of the unsaturated carboxylic acid represented by the aforementioned general formula (1), examples include esters, amides, acid anhydrides, and acyl chlorides of the unsaturated carboxylic acid. As an ester of the unsaturated carboxylic acid, an alkyl ester is preferred, and from the viewpoint of obtaining good reactivity, the number of carbon atoms in the alkyl group is preferably 1 to 6, more preferably 1 to 3, and even more preferably 1 to 2.

[0071] Examples of unsaturated carboxylic acids and their derivatives represented by the aforementioned general formula (1) include acrylic acid, methacrylic acid, α-ethylacrylic acid, α-propylacrylic acid, α-isopropylacrylic acid, α-n-butylacrylic acid, α-tert-butylacrylic acid, α-pentylacrylic acid, α-phenylacrylic acid, α-benzylacrylic acid, crotonic acid, 2-pentenoic acid, 2-hexenoic acid, 4-methyl-2-pentenoic acid, 2-heptenoic acid, 4-methyl-2-hexenoic acid, 5-methyl-2-hexenoic acid, 4,4-dimethyl-2-pentenoic acid, 4-phenyl-2-butenoic acid, cinnamic acid, o-methylcinnamic acid, m-methylcinnamic acid, p-methylcinnamic acid, 2-octenic acid, and their esters, amides, anhydrides, acyl chlorides, etc.

[0072] From the viewpoint of exhibiting high air barrier properties and impact resistance, component (x2) is preferably at least one selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid and their derivatives, more preferably at least one selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid and their alkyl esters, even more preferably at least one selected from the group consisting of acrylic acid, methacrylic acid and their alkyl esters, even more preferably an alkyl ester of acrylic acid, and even more preferably methyl acrylate.

[0073] Component (x2) can be used alone or in combination of two or more.

[0074] Regarding the reaction between component (x1) and component (x2), when using unsaturated carboxylic acids, esters, or amides as component (x2), it is carried out by mixing component (x1) and component (x2) at 0 to 100°C, more preferably 0 to 70°C, and conducting a Michael addition reaction and an amide group formation reaction based on dehydration, de-alcoholization, and deaminement at 100 to 300°C, preferably 130 to 250°C.

[0075] In this case, during the amide group formation reaction, the reaction apparatus can be subjected to reduced pressure in the final stage of the reaction to terminate the reaction, if necessary. Alternatively, a non-reactive solvent can be used for dilution if needed. Furthermore, catalysts such as phosphites can be added as dehydrating or dealcoholizing agents.

[0076] On the other hand, when using anhydrides and acyl chlorides of unsaturated carboxylic acids as components (x2), the reaction is carried out by mixing them at 0–150°C, preferably 0–100°C, followed by a Michael addition reaction and an amide group formation reaction. In this case, during the amide group formation reaction, the reaction apparatus may be subjected to reduced pressure in the final stage of the reaction to terminate the reaction, if necessary. Additionally, dilution with a non-reactive solvent may be used if needed. Furthermore, tertiary amines such as pyridine, methylpyridine, dimethylpyridine, and trialkylamines may be added.

[0077] The amide group formed by the reaction of component (x1) and component (x2) has high cohesive strength. Therefore, the cured epoxy resin composition obtained by using an epoxy resin curing agent containing the reaction product (X) of component (x1) and component (x2) has high gas barrier properties and good adhesion to continuous reinforcing fibers.

[0078] In the reaction product (X), the reaction molar ratio of component (x2) to component (x1) [(x2) / (x1)] is preferably in the range of 0.3 to 1.0, more preferably in the range of 0.6 to 1.0. If the above reaction molar ratio is 0.3 or more, a sufficient amount of amide groups are generated in the epoxy resin curing agent, exhibiting a high level of gas barrier properties and adhesion to reinforcing fibers. On the other hand, if the above reaction molar ratio is 1.0 or less, the amount of amino groups required for reaction with the epoxy groups in the epoxy resin (A1) is sufficient, and the heat resistance and solubility in organic solvents are also excellent.

[0079] The reaction product (X) may be the reaction product of the aforementioned components (x1) and (x2) with at least one compound further selected from the group consisting of components (x3), (x4) and (x5).

[0080] (x3) Choose freely R 3 At least one of the group consisting of monocarboxylic acids and their derivatives represented by -COOH (R) 3 (Represents a hydrogen atom, an alkyl group having 1 to 7 carbon atoms, or an aryl group having 6 to 12 carbon atoms, optionally containing a hydroxyl group.)

[0081] (x4) Cyclic carbonates

[0082] (x5) Monoepoxides with 2 to 20 carbon atoms

[0083] From the viewpoint of reducing the reactivity between the epoxy resin curing agent (B1) containing the reaction product (X) and the epoxy resin (A1), and improving workability and pot life, R can be used as a component (x3) as needed. 3 -COOH represents monocarboxylic acids and their derivatives.

[0084] R 3 R represents a hydrogen atom, an alkyl group having 1 to 7 carbon atoms (optionally containing a hydroxyl group), or an aryl group having 6 to 12 carbon atoms. 3 Preferably, it is an alkyl or phenyl group having 1 to 3 carbon atoms.

[0085] Additionally, as R 3Derivatives of the monocarboxylic acid represented by -COOH can include, for example, esters, amides, anhydrides, and acyl chlorides of the carboxylic acid. As an ester of the carboxylic acid, an alkyl ester is preferred, and the alkyl group preferably has 1 to 6 carbon atoms, more preferably 1 to 3, and even more preferably 1 to 2.

[0086] As components (x3), examples include monocarboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, lactic acid, glycolic acid, and benzoic acid, as well as their derivatives.

[0087] The ingredients (x3) can be used alone or in combination of two or more.

[0088] From the viewpoint of reducing the reactivity between the epoxy resin curing agent (B1) containing the reaction product (X) and the epoxy resin (A1), improving workability, pot life, etc., cyclic carbonates can be used as components (x4) as needed.

[0089] From the viewpoint of reactivity with component (x1), component (x4) is preferably a cyclic carbonate with a six-membered ring or less. Examples include ethylene carbonate, propylene carbonate, glyceryl carbonate, 1,2-butylene carbonate, vinylene carbonate, 4-vinyl-1,3-dioxolane-2-one, 4-methoxymethyl-1,3-dioxolane-2-one, and 1,3-dioxane-2-one. Among these, from the viewpoint of gas barrier properties, at least one selected from the group consisting of ethylene carbonate, propylene carbonate, and glyceryl carbonate is preferred.

[0090] The ingredients (x4) can be used alone or in combination of two or more.

[0091] The monoepoxy compound used as component (x5) is a monoepoxy compound with 2 to 20 carbon atoms, and is used as needed from the viewpoint of reducing the reactivity between the epoxy resin curing agent (B1) containing the reaction product (X) and the epoxy resin (A1), improving workability, and extending the pot life. From the viewpoint of gas barrier properties, component (x5) is preferably a monoepoxy compound with 2 to 10 carbon atoms, and more preferably a compound shown in the following formula (2).

[0092]

[0093] (In equation (2), R) 4 Representing hydrogen atoms, alkyl, aryl, chloromethyl or R groups having 1 to 8 carbon atoms 5 -O-CH2-;R 5 (This indicates phenyl or benzyl.)

[0094] Examples of monoepoxide compounds represented by formula (2) include ethylene oxide, propylene oxide, 1,2-butane oxide, phenyl ethylene oxide, epichlorohydrin, phenyl glycidyl ether, and benzyl glycidyl ether.

[0095] The ingredient (x5) can be used alone or in combination of two or more.

[0096] When the reaction product (X) uses component (x3), component (x4) or component (x5), any one of the compounds selected from the group consisting of component (x3), component (x4) and component (x5) can be used alone, or two or more can be used in combination.

[0097] It should be noted that the reaction product (X) can be a reaction product obtained by further reacting with other components (x1) to (x5) without impairing the effect of the present invention. Other components mentioned herein include, for example, aromatic dicarboxylic acids or their derivatives.

[0098] The amount of the "other components" is preferably 30% by mass or less of the total amount of the reaction components constituting the reaction product (X), more preferably 10% by mass or less, and even more preferably 5% by mass or less.

[0099] The reaction product of components (x1) and (x2) with at least one compound selected from the group consisting of components (x3), (x4), and (x5) can be obtained by combining at least one compound selected from the group consisting of components (x3), (x4), and (x5) with component (x2) and reacting it with component (x1) as a polyamine compound. The reaction can be performed by adding components (x2) to (x5) in any order and reacting them with component (x1), or by mixing components (x2) to (x5) and reacting them with component (x1).

[0100] The reaction between component (x1) and component (x3) can be carried out under the same conditions as the reaction between component (x1) and component (x2). When using component (x3), component (x2) and component (x3) can be mixed and reacted with component (x1), or component (x1) can be reacted with component (x2) first, and then reacted with component (x3).

[0101] On the other hand, when using component (x4) and / or component (x5), it is preferable to react component (x1) with component (x2) first, and then react with component (x4) and / or component (x5).

[0102] The reaction of component (x1) with component (x4) and / or component (x5) is carried out by mixing component (x1) with component (x4) and / or component (x5) at 25–200°C and carrying out an addition reaction at 30–180°C, preferably 40–170°C. Alternatively, catalysts such as sodium methoxide, sodium ethoxide, or potassium tert-butoxide may be used as needed.

[0103] In the above reaction, to promote the reaction, components (x4) and / or components (x5) may be melted or diluted with a non-reactive solvent as needed.

[0104] When the reaction product (X) is a reaction product of the aforementioned components (x1) and (x2) with at least one compound selected from the group consisting of the aforementioned components (x3), (x4), and (x5), the reaction molar ratio of the aforementioned component (x2) to component (x1) [(x2) / (x1)] is preferably in the range of 0.3 to 1.0, more preferably in the range of 0.6 to 1.0, for the same reasons as described above. On the other hand, the reaction molar ratio of the aforementioned components (x3), (x4), and (x5) to component (x1) [{(x3)+(x4)+(x5)} / (x1)] is preferably in the range of 0.05 to 3.1, more preferably in the range of 0.07 to 2.5, and even more preferably in the range of 0.1 to 2.0.

[0105] From the viewpoints of air barrier properties, workability, and service life, the reaction molar ratio of components (x2) to (x5) relative to component (x1) [{(x2)+(x3)+(x4)+(x5)} / (x1)] is preferably in the range of 0.35 to 2.5, and more preferably in the range of 0.35 to 2.0.

[0106] The epoxy resin curing agent (B1) may contain curing agent components other than the reaction product (X). "Curing agent components other than the reaction product (X)" refers to components having two or more functional groups that can react with the epoxy groups in the epoxy resin (A1) and other than the reaction product (X). From the viewpoint of reactivity with epoxy resin (A1) and gas barrier properties, preferred components include polyamine compounds and modified polyamine compounds having two or more amino groups in their molecules, other than component (x1).

[0107] Examples of such polyamine compounds include chain-like aliphatic polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, and hexamethylenediamine; polyamines with alicyclic structures such as 1,2-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, menthene diamine, isophorone diamine, norbornane diamine, and 1,4-diamino-3,6-diethylcyclohexane; polyamines with aromatic rings such as o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, phenylenediamine, diaminodiphenylmethane, and diaminodiphenyl sulfone; polyamines with heterocyclic structures such as N-aminomethylpiperazine and N-aminoethylpiperazine; and polyether polyamines. They can be used alone or in combination of two or more. Of the above, the polyamine compound is more preferably selected from at least one of the group consisting of 1,2-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, isophorone diamine, o-phenylenediamine, m-phenylenediamine and p-phenylenediamine.

[0108] Examples of modified polyamine compounds include reaction products of polyamine compounds with epoxides, and Mannich reaction products of polyamine compounds, phenolic compounds, and aldehydes.

[0109] From the viewpoint of exhibiting high gas barrier properties and impact resistance, the epoxy resin curing agent (B1) preferably has a high content of reaction product (X). From this viewpoint, the content of reaction product (X) in the epoxy resin curing agent (B1) is preferably 50% by mass or more, more preferably 70% by mass or more, further preferably 80% by mass or more, and even more preferably 90% by mass or more. Furthermore, the upper limit is 100% by mass.

[0110] Regarding the ratio of epoxy resin (A1) to epoxy resin curing agent (B1) in the epoxy resin composition, it can be the standard ratio generally used when preparing epoxy resin reactants by reacting epoxy resin and epoxy resin curing agent. Specifically, the ratio of the number of active amine hydrogens in epoxy resin curing agent (B1) to the number of epoxy groups in epoxy resin (A1) (number of active amine hydrogens in epoxy resin curing agent (B1) / number of epoxy groups in epoxy resin (A1)) is preferably in the range of 0.2 to 12.0. From the viewpoint of exhibiting high gas barrier properties and impact resistance, (number of active amine hydrogens in epoxy resin curing agent (B1) / number of epoxy groups in epoxy resin (A1)) is more preferably 0.4 to 10.0, further preferably 0.6 to 8.0, even more preferably 0.9 to 6.0, and even more preferably in the range of more than 1.0 and less than 5.0.

[0111] From the viewpoint of further improving impact resistance, the ratio of (number of active amine hydrogens in epoxy resin curing agent (B1) / number of epoxy groups in epoxy resin (A1)) is more preferably 1.1 or more, and from the viewpoint of further improving hydrogen barrier properties, it is more preferably 4.0 or less, and even more preferably 3.2 or less.

[0112] The epoxy resin composition may be an epoxy resin composition in which the main agent (A) is an epoxy resin (A1) and the curing agent (B) does not contain the aforementioned reaction product (X).

[0113] From the viewpoint of reactivity with epoxy resin (A1) and gas barrier properties, the aforementioned polyamine compound or its modified form is preferred as the epoxy resin curing agent. More preferably, the polyamine compound is selected from at least one of the following groups: 1,2-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, isophorone diamine, o-phenylenediamine, m-phenylenediamine, and p-phenylenediamine.

[0114] Furthermore, the preferred range of the ratio of the number of active amine hydrogens in the epoxy resin curing agent to the number of epoxy groups in the epoxy resin (A1) in this case (number of active amine hydrogens in the epoxy resin curing agent / number of epoxy groups in the epoxy resin (A1)) is the same as the range described above (number of active amine hydrogens in the epoxy resin curing agent (B1) / number of epoxy groups in the epoxy resin (A1)).

[0115] [Solvent]

[0116] In the thermosetting resin compositions such as the main agent (A) composition, the curing agent (B) composition, and the epoxy resin composition used in process (I), from the viewpoint of improving the impregnation of the composition in the continuous reinforcing fiber bundle by achieving a low viscosity and from the viewpoint of adjusting the pot life, a solvent may be further contained.

[0117] In this invention, "solvent" refers to both reactive solvents, such as reactive diluents, and non-reactive solvents. From the viewpoint of improving pot life, the solvent is preferably a non-reactive solvent.

[0118] Specific examples of non-reactive solvents include alcohol solvents such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, 2-butoxyethanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, and 1-propoxy-2-propanol; ester solvents such as ethyl acetate and butyl acetate; ketone solvents such as acetone and methyl isobutyl ketone; ether solvents such as diethyl ether and diisopropyl ether; hydrocarbon solvents such as toluene; and non-reactive diluents such as benzyl alcohol. One or more of these solvents may be used.

[0119] From the viewpoint of the solubility of the aforementioned epoxy resin (A1) and epoxy resin curing agent (B1), and from the viewpoint of the ease of solvent removal, the solvent is preferably at least one non-reactive diluent selected from the group consisting of alcohol solvents, ester solvents and hydrocarbon solvents having 8 or fewer carbon atoms, more preferably at least one selected from the group consisting of methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, ethyl acetate and toluene, and even more preferably at least one selected from the group consisting of methanol and ethyl acetate.

[0120] When the composition of the main agent (A), the composition of the curing agent (B), or the thermosetting resin composition contains a solvent, its content is not particularly limited. From the viewpoint of improving the permeability of the composition in the continuous reinforcing fiber bundle and adjusting the pot life, it is preferably 5% by mass or more in each composition. From the viewpoint of ease of solvent removal and control of its permeation in the continuous reinforcing fiber bundle, it is preferably 95% by mass or less, more preferably 90% by mass or less, further preferably 80% by mass or less, and even more preferably 70% by mass or less.

[0121] In the manufacturing method of the present invention, compositions with low solvent content and solvent-free compositions can also be used as thermosetting resin compositions. Generally, thermosetting resin compositions containing non-reactive solvents can maintain a longer pot life, but the manufacturing method of the present invention includes step (I), so even solvent-free compositions with short pot life can be used.

[0122] That is, the composition of the main agent (A) and the composition of the curing agent (B) used in this invention can also reduce the solvent content and can also be made into a solvent-free product.

[0123] From the viewpoint of ease of solvent removal and control of its impregnation in continuous reinforcing fiber bundles, the solvent content in, for example, the composition of the main agent (A), the composition of the curing agent (B), or the thermosetting resin composition is preferably set to 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less. In particular, from the viewpoint of ease of solvent removal and control of its impregnation in continuous reinforcing fiber bundles, the composition of the main agent (A) is preferably solvent-free. Furthermore, the solvent content in the composition of the curing agent (B) is preferably 40% by mass or less.

[0124] It should be noted that, in this invention, a thermosetting resin composition with a short pot life refers to a composition in the case of, for example, a two-component thermosetting resin composition, where the pot life of the main agent (A) and the curing agent (B) after mixing is preferably less than 1 hour, more preferably less than 30 minutes, further preferably less than 20 minutes, even more preferably less than 10 minutes, and even more preferably less than 10 minutes. More specifically, the time (gelation time) from when the main agent (A) and the curing agent (B) are mixed and left to stand at 23°C until a gel is formed is preferably less than 1 hour, more preferably less than 30 minutes, further preferably less than 20 minutes, even more preferably less than 10 minutes, and even more preferably less than 10 minutes. The above-mentioned gelation time can be measured using a rheometer. Specifically, the storage modulus G' and loss modulus G'" of the thermosetting resin or composition are measured using a rheometer at a temperature of 23°C, a frequency of 1Hz, and a plate-to-plate distance of 0.5mm, and the intersection of G' and G'" is defined as the gelation time.

[0125] Within the scope that does not impair the effects of the present invention, coupling agents, curing accelerators, wetting agents, rubber, thermoplastic resins, thickeners, defoamers, rust inhibitors, lubricants, pigments, oxygen scavengers, ultraviolet absorbers, antioxidants, and other additives may be further blended into the thermosetting resin composition as needed.

[0126] When the above composition contains additives, the total content of the additives in the composition is preferably 20.0 parts by mass or less, more preferably 0.001 to 15.0 parts by mass, relative to 100 parts by mass of the thermosetting resin in the thermosetting resin composition (in the case of a two-component type, the total amount of the main agent (A) and the curing agent (B)).

[0127] From the viewpoint of achieving the effects of the present invention, the content of thermosetting resin (in the case of a two-component type, the main agent (A) and the curing agent (B)) in the solid component of the thermosetting resin composition is preferably 60% by mass or more, more preferably 70% by mass or more, further preferably 80% by mass or more, even more preferably 85% by mass or more, and the upper limit is 100% by mass. "Solid component of the thermosetting resin composition" refers to the component after removing the solvent from the thermosetting resin composition.

[0128] (Continuous reinforcing fiber)

[0129] The continuous reinforcing fiber used in this invention is a reinforcing fiber with a fiber length of more than 100 mm.

[0130] Examples of continuous reinforcing fiber shapes include tows, sheets, and ribbons. Examples of continuous reinforcing fibers that make up sheets or ribbons include unidirectional (UD) materials, woven fabrics, and nonwoven fabrics.

[0131] From the viewpoint of obtaining a molded article by the manufacturing method of the present invention, the shape of the continuous reinforcing fiber is preferably a tow or a ribbon, more preferably a tow (continuous reinforcing fiber yarn). As the continuous reinforcing fiber yarn, in addition to using fiber bundles with a generally circular cross-section, fiber bundles (rovings) with a flat cross-section can also be used.

[0132] In addition, as a single yarn constituting a continuous reinforcing fiber, fibers with a flat cross-section can also be used, in addition to fibers with a roughly circular cross-section.

[0133] From the viewpoint of easily obtaining high strength and high elastic modulus, the number of fibers (filaments) constituting the continuous reinforcing fiber bundle is preferably 0.3K to 60K, more preferably 3K to 60K, and even more preferably 6K to 50K.

[0134] The average fiber length of the continuously reinforcing fiber bundle is not particularly limited, but from the viewpoint of molding and processability, it is preferably 100 to 100,000 m, and more preferably 500 to 10,000 m.

[0135] A higher average fineness value of the continuously reinforcing fiber bundles improves the production efficiency of the molded articles. From the viewpoints of production efficiency, molding processability, and ease of obtaining high strength and high elastic modulus, the average fineness of the continuously reinforcing fiber bundles is preferably 50 to 10,000 tex (g / 1000m), more preferably 200 to 7,500 tex, and even more preferably 500 to 5,000 tex.

[0136] In addition, the average tensile modulus of the continuously reinforcing fiber bundle is preferably 100 to 1000 GPa.

[0137] Examples of materials that can be used as continuous reinforcing fibers include inorganic fibers such as glass fiber, carbon fiber, metal fiber, boron fiber, basalt fiber, and ceramic fiber; and organic fibers such as aromatic polyamide fiber, polyoxymethylene fiber, poly(p-phenylenebenzobisoxazole) fiber, and ultra-high molecular weight polyethylene fiber. Among these, inorganic fibers are preferred from the viewpoint of obtaining high strength, and from the viewpoint of exhibiting lightweight, high strength, and high elastic modulus, at least one fiber selected from the group consisting of glass fiber, carbon fiber, and basalt fiber is more preferred, and carbon fiber is even more preferred.

[0138] Examples of carbon fibers include polyacrylonitrile-based carbon fibers and pitch-based carbon fibers. Additionally, carbon fibers derived from plant sources such as lignin and cellulose can also be used.

[0139] The continuous reinforcing fibers used in this invention can be treated with a treatment agent. Examples of treatment agents include surface treatment agents or bundling agents.

[0140] As the surface treatment agent described above, a silane coupling agent is preferred. Examples of silane coupling agents include vinyl silane coupling agents, amino silane coupling agents, epoxy silane coupling agents, (meth)acryloyl silane coupling agents, and mercapto silane coupling agents.

[0141] Examples of such bundlers include urethane-based bundlers, epoxy-based bundlers, acrylic-based bundlers, polyester-based bundlers, vinyl ester-based bundlers, polyolefin-based bundlers, polyether-based bundlers, and carboxylic acid-based bundlers. One of these or a combination of two or more can be used. Examples of bundlers combining two or more types include urethane / epoxy bundlers, urethane / acrylic bundlers, and urethane / carboxylic acid bundlers.

[0142] From the viewpoint of improving the interfacial adhesion to the cured product of the thermosetting resin or composition, especially the cured product of the epoxy resin composition, and further improving the strength and impact resistance of the resulting molded article, the continuous reinforcing fiber is preferably treated with one or more of the group consisting of urethane-based bundlers, epoxy-based bundlers, and urethane / epoxy-based bundlers, and more preferably treated with an epoxy-based bundler.

[0143] From the viewpoint of improving the interfacial adhesion to the cured thermosetting resin or thermosetting resin composition and further improving the strength and impact resistance of the resulting molded article, the amount of the aforementioned treatment agent relative to the continuous reinforcing fiber is preferably 0.001 to 5% by mass, more preferably 0.1 to 3% by mass, and even more preferably 0.5 to 2% by mass.

[0144] Commercially available products can also be used as continuous reinforcing fibers. Examples of commercially available carbon fibers as continuous reinforcing fibers include Toray Industries' various series of toreca yarns: "T300", "T300B", "T400HB", "T700SC", "T800SC", "T800HB", "T830HB", "T1000GB", "T100GC", "M35JB", "M40JB", "M46JB", "M50JB", "M55J", "M55JB", "M60JB", "M30SC", and "Z600"; and toreca fabrics such as "CO6142", "CO6151B", "CO6343", "CO6343B", "CO6347B", "CO6644B", "CK6244C", "CK6273C", "CK6261C", "UT70" series, "UM46" series, and "BT70" series. In addition, commercially available glass fiber products include the "E-glass yarn" series manufactured by Nitto Boki Co., Ltd.

[0145] When using a two-component thermosetting resin composition containing a main agent (A) and a curing agent (B), the coating process of step (I) can be exemplified by: a process of coating the main agent (A) or its composition onto the surface of a continuous reinforcing fiber bundle and a process of coating the curing agent (B) or its composition; and a process of coating the main agent (A) or its composition onto the surface of the continuous reinforcing fiber bundle after pre-mixing the curing agent (B) or its composition. Methods for pre-mixing the main agent (A) and the curing agent (B) can be exemplified by, for example, mixing the main agent (A) or its composition with the curing agent (B) or its composition using a stirrer; or feeding the main agent (A) or its composition and the curing agent (B) or its composition from both sides of a T-tube respectively, causing the main agent (A) or its composition to collide and mix with the curing agent (B) or its composition, etc.

[0146] When using thermosetting resin compositions with short pot life, step (I) preferably includes a step of coating the surface of the continuous reinforcing fiber bundles with a main agent (A) or a composition thereof, and a step of coating with a curing agent (B) or a composition thereof.

[0147] In step (I), as a method for coating the surface of a continuous reinforcing fiber bundle with a thermosetting resin or composition, there is no particular limitation. Examples include spraying the coating agent (A), curing agent (B), thermosetting resin, or a combination thereof onto the surface of the continuous reinforcing fiber bundle from a nozzle capable of supplying the thermosetting resin or composition.

[0148] When the process includes a step of coating a main agent (A) or a composition thereof onto the surface of a continuous reinforcing fiber bundle and a step of coating a curing agent (B) or a composition thereof, from the viewpoint of avoiding the curing of the thermosetting resin composition in the manufacturing process, it is preferable to spray the main agent (A) or a composition thereof onto one side of the continuous reinforcing fiber bundle and spray the curing agent (B) or a composition thereof onto the other side. The "other side" is preferably the side opposite to the aforementioned "one side".

[0149] <Process (II): Resin Impregnation Process>

[0150] In step (II), after step (I), the continuous reinforcing fiber bundle is twisted to impregnate it with a thermosetting resin or a thermosetting resin composition to obtain a prepreg. By performing step (II), the thermosetting resin or composition can be allowed to flow, promoting its impregnation within the continuous reinforcing fiber bundle. Furthermore, when using a two-component thermosetting resin composition, even if the main agent (A) or a composition containing it and the curing agent (B) or a composition containing it are separately coated onto the continuous reinforcing fiber bundle in step (I), the main agent (A) and the curing agent (B) will be thoroughly mixed within the continuous reinforcing fiber bundle.

[0151] In step (II), the continuous reinforcing fiber bundle obtained in step (I) is twisted (twisting step). The twisting direction is preferably one direction, preferably a circumferential direction that is substantially perpendicular to the length direction of the continuous reinforcing fiber bundle. For example, if the continuous reinforcing fiber bundle is a filament bundle, twisting is performed along a circumferential direction that is substantially perpendicular to the length direction of the filament bundle. Through this operation, the thermosetting resin or composition coated in step (I) can be fully impregnated into the continuous reinforcing fiber bundle.

[0152] From the viewpoint of ensuring that the thermosetting resin or composition coated in step (I) is fully impregnated into the continuous reinforcing fiber, the twisting speed of the continuous reinforcing fiber bundle is preferably 20 to 300 revolutions per meter of continuous reinforcing fiber, more preferably 50 to 200 revolutions per meter, and even more preferably 70 to 150 revolutions per meter.

[0153] The twisting process in process (II) can also be achieved through... Figure 1 The institution shown will carry it out. Figure 1 (a) and (b) are schematic diagrams illustrating one embodiment of the twisting process in step (II). Figure 1 (a) is a diagram viewed from the top surface. Figure 1 (b) is a view taken from the side. Figure 1 In this context, A is the continuous reinforcing fiber yarn coated with a thermosetting resin or thermosetting resin composition in process (I), and B1 and B2 are traction rollers. The continuous reinforcing fiber yarn A, held between the two traction rollers B1 and B2, is conveyed along its length (axial direction) by the rotation of the traction rollers. Here, as... Figure 1 As shown in (a), by tilting the rotation axes of the two traction rollers in opposite directions by θ°, the continuous reinforcing fiber yarn A is rotated in the circumferential direction, which allows the continuous reinforcing fiber yarn to be twisted and pulled in the axial direction at the same time.

[0154] Step (II) preferably includes a step of untwisting after twisting the continuous reinforcing fiber bundle. By performing the untwisting step, the thermosetting resin or composition can be further flowed by using the recovery of the twisted continuous reinforcing fiber bundle as a driving force, thereby promoting its impregnation and mixing within the continuous reinforcing fiber bundle.

[0155] The untwisting process is performed by twisting the continuously reinforcing fiber bundle in the opposite direction to the twisting direction in the twisting process. In use... Figure 1 In the case of a twisting mechanism, untwisting is achieved by tilting the rotation axes of the two traction rollers θ° in the opposite direction to the twisting process and applying traction.

[0156] The untwisting process can be performed alternately with the twisting process. For example, in the twisting process, after twisting the continuous reinforcing fiber bundle by rotating it once in a circumferential direction that is approximately perpendicular to the length direction of the continuous reinforcing fiber bundle, it is then twisted once in the opposite direction, thereby untwisting. By repeating this series of operations, the thermosetting resin or composition can be fully impregnated into the continuous reinforcing fiber bundle.

[0157] When performing the untwisting process, the rotation speed is preferably the same as the twisting speed in the twisting process, preferably 20 to 300 revolutions per 1m length of continuous reinforcing fiber bundle, more preferably 50 to 200 revolutions per 1m length, and even more preferably 70 to 150 revolutions per 1m length.

[0158] The twisting and untwisting processes in process (II) can be performed manually or mechanically using a device with a twisting mechanism, such as the resin impregnation device described later.

[0159] After the twisting process or in the case of a detwisting process, a process can be performed to remove the remaining thermosetting resin or composition coated on the continuous reinforcing fiber bundle. It should be noted that, in the following description, the process of removing the remaining thermosetting resin or composition is also referred to as the "twisting process." This process further promotes the penetration of the thermosetting resin or composition into the continuous reinforcing fiber bundle. Furthermore, by performing this process, the cross-section perpendicular to the forward direction (length direction) of the continuous reinforcing fiber bundle becomes elliptical or flat, thus suppressing gap formation and strength reduction caused by unevenness (curling) when stacking prepregs in step (III). The twisting process can be performed using, for example, rollers.

[0160] Furthermore, after the twisting process or in the case of the untwisting process, a process to remove solvents and other contaminants contained in the thermosetting resin composition (solvent removal process) may be performed as needed. From a productivity point of view, the solvent removal process is usually performed under heating. There are no particular limitations on the heating conditions, as long as they are sufficient to remove the solvent and prevent excessive curing of the thermosetting resin, and they can be appropriately selected according to the type of thermosetting resin and solvent. For example, the heating temperature can be selected in the range of 30 to 100°C, and the heating time can be selected in the range of 10 seconds to 10 minutes.

[0161] The solvent removal process described above can be performed using known methods such as hot air dryers, heaters, heating rollers, and heating plates. Examples include methods that involve moving the solvent within a heating atmosphere based on a hot air dryer or heater; and methods that involve contacting the solvent with heating elements such as heating rollers or heating plates. Among these, the method using a hot air dryer is preferred.

[0162] By performing the above steps (I) and (II), a prepreg is obtained in which a continuous reinforcing fiber bundle is impregnated with a thermosetting resin or composition.

[0163] The prepreg obtained in process (II) can be temporarily wound into bobbins, etc. From the point of view of improving productivity, it is preferable to supply it to process (III) without winding.

[0164] From the viewpoint of productivity of the molded article, processes (I) and (II) are preferably performed using a resin impregnation apparatus, which includes a mechanism for feeding a continuous reinforcing fiber bundle; a nozzle for spraying the aforementioned thermosetting resin or thermosetting resin composition onto the surface of the continuous reinforcing fiber bundle; and a mechanism for twisting the continuous reinforcing fiber bundle. The resin impregnation apparatus will be described below.

[0165] <Process (III): Heating and Forming Process>

[0166] In step (III), the prepreg obtained in step (II) is prepared and then heated to obtain a molded body. "Prepreg preparation" refers to the stacking of prepregs in a manner that presents the desired shape of the molded body.

[0167] The method for preparing the prepreg can be appropriately selected based on the shape of the prepreg and the resulting molded body. For example, when the prepreg is a towed prepreg, weaving, winding, or 3D printing methods can be used. Weaving and winding can be performed using known methods. When using 3D printing, the 3D printer of the present invention, described later, is preferred.

[0168] From the viewpoint that pressure vessels and other molded objects can be formed without using core materials such as mandrels, the molding method in step (III) is preferably a weaving method or a 3D printing method. From the viewpoint of forming complex shapes, the 3D printing method is more preferred.

[0169] The heating in step (III) is carried out by known methods at a temperature and time sufficient for curing the thermosetting resin contained in the prepared prepreg. From the viewpoint of improving productivity, the heating temperature is preferably set in the range of 80 to 150°C, and the heating time is preferably set in the range of 10 minutes to 5 hours.

[0170] By employing the manufacturing method comprising the steps (I) to (III) described above in sequence, it is possible to efficiently manufacture molded articles formed from a cured product containing a thermosetting resin or a thermosetting resin composition and containing continuous reinforcing fibers.

[0171] The content of continuous reinforcing fibers in the molded article obtained by the manufacturing method of the present invention is not particularly limited. From the viewpoint of high strength and high elastic modulus of the molded article, the volume fraction (Vf) of the continuous reinforcing fibers is preferably 10% or more, more preferably 20% or more, further preferably 30% or more, and even more preferably 40% or more. In addition, from the viewpoint of air barrier properties and impact resistance of the molded article, this volume fraction is preferably 98% or less, more preferably 95% or less, further preferably 80% or less, and even more preferably 70% or less.

[0172] The volume fraction Vf of continuous reinforcing fibers in the molded body can be calculated according to the following formula.

[0173] Vf(%) = {Mass of continuous reinforcing fiber (g) / Specific gravity of continuous reinforcing fiber} ÷ [{Mass of continuous reinforcing fiber (g) / Specific gravity of continuous reinforcing fiber} + {Mass of cured thermosetting resin (composition) (g) / Specific gravity of cured thermosetting resin (composition)}] × 100

[0174] Furthermore, from the viewpoint of high strength and high elastic modulus of the molded article, the total content of cured thermosetting resin or composition and continuous reinforcing fibers in the molded article is preferably 70% by mass or more, more preferably 80% by mass or more, further preferably 90% by mass or more, and the upper limit is 100% by mass.

[0175] <Pressure Vessel>

[0176] As an example of a molded body manufactured by the manufacturing method of the present invention, a pressure vessel can be cited. In particular, when an epoxy resin composition in which the main agent (A) is the aforementioned epoxy resin (A1) and the curing agent (B) is the aforementioned epoxy resin curing agent (B1) is used as a thermosetting resin composition, the resulting pressure vessel exhibits good gas barrier properties against hydrogen and the like, and also has excellent lightweight, pressure resistance, and impact resistance.

[0177] The storage medium for pressure vessels can be a gas or liquid at 25°C and 1 atm, preferably a gas at 25°C and 1 atm. Specific examples include, in addition to hydrogen, oxygen, carbon dioxide, nitrogen, argon, LPG, Freon substitutes, methane, etc. Of these, hydrogen is preferred from the viewpoint of effectiveness when using the aforementioned epoxy resin composition as a thermosetting resin composition.

[0178] As pressure vessels, examples include (1) a pressure vessel having a gasket and an outer layer for reinforcing the gasket, and (2) a pressure vessel without a gasket. The manufacturing method of the present invention can also be applied to any of the pressure vessels in (1) and (2). In the pressure vessel of (1), the manufacturing method of the present invention can be applied to the manufacture of either or both of the gasket and the outer layer.

[0179] From the viewpoints of effectiveness and lightweight design, pressure vessels are preferably without gaskets.

[0180] The following explanation focuses on pressure vessels, specifically those without gaskets.

[0181] A pressure vessel only needs to have an internal space to be filled with gas, and is usually hollow. Refer to the attached diagram for an explanation of the shape of a pressure vessel.

[0182] Figure 2 This is a cross-sectional schematic diagram showing one embodiment of a pressure vessel. Figure 2 In the process, the pressure vessel 100 without a gasket is shaped with a cylindrical portion 1 and two dome-shaped ends 2a and 2b, which seal the two ends (1a and 1b) of the cylindrical portion 1.

[0183] Both dome 2a and 2b are hollow, and at least one of the domes (in) Figure 1 2a) An opening 3 for connecting a valve or the like for a pressure vessel can be provided at the top of the rounded top. The rounded top may be pre-installed with a valve or the like for a pressure vessel.

[0184] Pressure vessels may also be fitted with optional layers such as protective layers, coating layers, and rust-proof layers (not shown in the illustration) as needed.

[0185] The fiber-reinforced composite material constituting the pressure vessel 100 is formed using the prepreg obtained in the aforementioned step (II). By molding the prepreg obtained in the aforementioned step (II), preferably a tow prepreg, using a weaving method, winding method, 3D printing method, or the like in the aforementioned step (III), a pressure vessel 100 composed of a fiber-reinforced composite material having a helical surface structure, a braided structure, a spiral structure, or the like, can be obtained. That is, the prepreg (preferably a tow prepreg) obtained in step (II) of the aforementioned manufacturing method is arranged in step (III) in a form that presents the shape of a pressure vessel having a helical surface structure, a braided structure, or a spiral structure.

[0186] From the viewpoint of improving air barrier properties, strength, and impact resistance, the fiber-reinforced composite material constituting the pressure vessel 100 preferably has a braided or helical structure. The braided and helical structures are formed by seamlessly configuring the cured prepreg, which consists of a thermosetting resin or composition and continuous reinforcing fiber bundles, into a braided or helical structure, thereby constituting a hollow pressure vessel 100.

[0187] If a prepreg consisting of a thermosetting resin or composition and continuous reinforcing fiber bundles is used in step (III) and formed by weaving, a pressure vessel with a braided structure can be manufactured. Alternatively, if the prepreg is formed by unidirectional weaving, winding, or 3D printing, a pressure vessel with a helical structure can be manufactured. Pressure vessels with braided or helical structures exhibit excellent gas barrier properties, strength, and impact resistance, and are also advantageous in terms of productivity.

[0188] From the viewpoints of air barrier properties, strength, impact resistance, and productivity, the cylindrical portion 1 constituting at least the pressure vessel 100 preferably has a braided or spiral structure. The domed tops 2a and 2b constituting the pressure vessel 100 may also be made of fiber-reinforced composite materials with braided or spiral structures, but there are no particular limitations.

[0189] Figure 2 The pressure vessel 100 can be formed by separately manufacturing the cylindrical part and the dome and joining them together, or the cylindrical part and the dome can be formed together. From a productivity point of view, it is preferable to form the cylindrical part 1 together with at least one dome.

[0190] If weaving, winding, or 3D printing is used in process (III), the cylindrical part and the dome of the pressure vessel can be easily formed together.

[0191] When manufacturing the dome of a pressure vessel separately, the manufacturing method is not particularly limited. It can be manufactured, for example, by hot-pressing a prepreg in which reinforcing fibers are pre-impregnated with a thermosetting resin or composition using a mold. If the thermosetting resin or composition used is solvent-free, it can also be manufactured using known molding methods such as Va-RTM (vacuum-assisted resin transfer molding), RTM (resin transfer molding), and HP-RTM (high-pressure resin transfer molding).

[0192] At this point, the same materials as those constituting the cylindrical portion of the pressure vessel can be used as the thermosetting resin or composition constituting the dome and the reinforcing fibers.

[0193] When the manufacturing method of the present invention forms only the cylindrical portion of the pressure vessel or forms only a component that seals one end of the cylindrical portion, a separately manufactured dome can be joined to one or both ends of the cylindrical portion for sealing, thereby manufacturing a pressure vessel.

[0194] The thickness of pressure vessel 100 ( Figure 2 The thickness of the fiber (t) can be appropriately selected based on the capacity and shape of the pressure vessel, as well as the thickness of the continuous reinforcing fibers used or the outer diameter of the fiber bundle. From the viewpoint of ensuring sufficient gas barrier properties and pressure resistance for the pressure vessel, the thickness of the pressure vessel is preferably 100 μm or more, more preferably 200 μm or more, and even more preferably 400 μm or more. From the viewpoint of miniaturization and weight reduction of the pressure vessel, it is preferably 60 mm or less, more preferably 40 mm or less.

[0195] [Resin Impregnation Device]

[0196] The present invention provides a resin impregnation apparatus comprising a mechanism for feeding a continuous reinforcing fiber bundle, a nozzle for spraying a thermosetting resin or a thermosetting resin composition onto the surface of the continuous reinforcing fiber bundle, and a mechanism for twisting the continuous reinforcing fiber bundle.

[0197] The resin impregnation apparatus can be suitably used in steps (I) and (II) of the manufacturing method of the present invention.

[0198] The resin impregnation apparatus of the present invention will be described with reference to the accompanying drawings.

[0199] Figure 3 This is a schematic diagram illustrating one embodiment of a resin impregnation apparatus and a 3D printer equipped with it. Figure 3 In this process, the resin impregnation apparatus 200 includes a conveying roller 20 for feeding out a continuous reinforcing fiber bundle 11, a nozzle 21 (21a, 21b) for spraying a thermosetting resin or a thermosetting resin composition onto the surface of the fed continuous reinforcing fiber bundle 11, and a twisting mechanism 22 for twisting the continuous reinforcing fiber bundle 11.

[0200] The nozzle 21 is a mechanism for spraying thermosetting resin or a thermosetting resin composition onto the surface of the continuous reinforcing fiber bundle 11, and is capable of performing step (I) in the manufacturing method of the present invention.

[0201] Nozzle 21 is connected to tanks 23 (23a, 23b) filled with thermosetting resin or composition, and thermosetting resin or composition is supplied from tank 23 to nozzle 21 via resin supply lines 24 (24a, 24b). When using a two-component thermosetting resin composition containing a main agent (A) and a curing agent (B) as the thermosetting resin composition, it is preferable to have tank 23a for filling the main agent (A) or its composition and tank 23b for filling the curing agent (B) or its composition. With this configuration, it is easy to use a thermosetting resin composition with a short shelf life in step (I).

[0202] exist Figure 3 In the process, tank 23a is connected in sequence to resin supply line 24a and nozzle 21a, and tank 23b is connected in sequence to resin supply line 24b and nozzle 21b. In addition, nozzles 21a and 21b are positioned opposite each other in a manner that clamps the sides of the continuous reinforcing fiber bundle 11. The main agent (A) or its composition can be sprayed from nozzle 21a to one side of the continuous reinforcing fiber bundle 11, and the curing agent (B) or its composition can be sprayed from nozzle 21b to the other side.

[0203] In the method of using a two-component thermosetting resin composition containing a main agent (A) and a curing agent (B) as the thermosetting resin composition, when the main agent (A) or its composition is mixed by collision and then applied to the surface of the continuous reinforcing fiber bundle 11, it is preferable to provide a confluence section 25 (not shown) upstream of the nozzle 21, connecting the resin supply line 24a connected to the tank 23a and the resin supply line 24b connected to the tank 23b. This allows the main agent (A) or its composition to be mixed with the curing agent (B) or its composition in the confluence section 25, and the resulting thermosetting resin composition to be supplied to the nozzle 21. The confluence section 25 may be constructed of a T-tube or the like.

[0204] The resin impregnation apparatus 200 includes a twisting mechanism 22. The twisting mechanism 22 can be used to perform step (II) in the manufacturing method of the present invention. The twisting mechanism 22 is located downstream of the nozzle 21.

[0205] A continuous reinforcing fiber bundle 11 coated with a thermosetting resin or composition using a nozzle 21 is twisted using a twisting mechanism 22, preferably in a circumferential direction substantially perpendicular to the direction of travel. This allows the thermosetting resin or composition to be fully impregnated and mixed into the continuous reinforcing fiber bundle 11.

[0206] In step (II) of the manufacturing method of the present invention, if the continuous reinforcing fiber bundle 11 is twisted in a unidirectional direction using the twisting mechanism 22, the untwisting step can be performed.

[0207] It should be noted that the twisting mechanism 22 can be Figure 1 The twisting mechanism is illustrated in the image.

[0208] The resin impregnation device 200 may have a pinch roller 26 on the downstream side of the twisting mechanism 22 for removing residual thermosetting resin or composition coated on the continuous reinforcing fiber bundle 11.

[0209] The resin impregnation apparatus 200 may be further equipped with a drying mechanism 27 if needed. The drying mechanism 27 is preferably located downstream of the twisting mechanism 22 (or downstream of it if the pinch roller 26 is provided).

[0210] The drying unit 27 is provided for removing the solvent from the thermosetting resin composition that has permeated into the continuous reinforcing fiber bundle 11. Examples of its form include a hot air dryer, a heater, a heating roller, and a heating plate.

[0211] A continuous reinforcing fiber bundle 11 impregnated with a solvent-containing thermosetting resin composition is passed through a drying unit 27, thereby removing the solvent to form a prepreg.

[0212] [3D printer]

[0213] The present invention also provides a 3D printer equipped with the aforementioned resin impregnation device. This 3D printer is applicable to the manufacturing method of the present invention.

[0214] The 3D printer of the present invention preferably includes at least the aforementioned resin impregnation device and robotic arm. By performing steps (I) and (II) using the resin impregnation device, and using the obtained prepreg and the robotic arm to perform step (III) molding, it is possible to easily manufacture three-dimensional shaped bodies.

[0215] Figure 3 The 3D printer 400 shown is configured with a resin impregnation device 200 and a robotic arm 300.

[0216] The robotic arm 300 consists of a support platform 30 for preparing the prepreg obtained in step (II) and an arm 31 for holding the support platform 30. The arm 31 holds the support platform 30 and, through mechanical control, allows the position (X, Y, Z directions), rotation direction, tilt angle, etc., of the support platform 30 to be freely adjusted. The arm 31 is connected to, for example, the lower surface of the support platform 30 in a manner that holds the support platform 30.

[0217] The position, rotation direction, and tilt of the support platform 30 can be freely changed by the movement of the arm 31, thereby arranging the prepreg supplied by the resin impregnation device 200 onto the support platform 30 into the desired shape. The movement of the arm 31 is controlled by, for example, a control device (not shown) according to a programmed procedure.

[0218] Prepreg supplied from the resin impregnation apparatus 200 toward the robotic arm 300 is pressed and stacked on the support table 30 using the stacking roller 32, and formed into the desired shape. According to this method, even when forming a pressure vessel without a liner, it is possible to form it simultaneously without using a core material such as a mandrel.

[0219] Next, the laminate 33 obtained by placing the prepreg on the support 30 is heated to obtain a molded article formed of fiber-reinforced composite material. The heating of the laminate 33 can be supplied to the heating mechanism while it is placed on the support 30, or it can be moved from the support 30 and supplied to the heating mechanism.

[0220] Example

[0221] The present invention will then be specifically described through examples. However, the present invention is not limited to these examples at all.

[0222] The measurement and evaluation in this embodiment are performed using the following methods.

[0223] Hydrogen permeability coefficient [cc·cm / (cm)] 2 ·s·cmHg)]>

[0224] Using a rod coater, the mixture of the main agent and curing agent solution (epoxy resin composition) used in Example 1 was coated onto a smooth metal plate coated with a release agent to a thickness of 100 μm and a square of 200 mm. The coated plate was then heated at 100°C for 5 minutes to cure, producing a cured product. Using this cured product, the hydrogen permeability coefficient was measured under dry conditions at 23°C using a vapor transmission rate measuring device (GTR TECH "G2700T·F").

[0225] <Permeability>

[0226] In each case, the following methods were used to evaluate the impregnation of thermosetting resin compositions in continuous reinforcing fiber bundles.

[0227] An arbitrary vertical cross-section was ground from the molded body, and the cross-section was photographed using an ultra-deep color 3D shape measuring microscope. For the obtained cross-sectional photographs, the image analysis software "ImageJ" was used to select the impregnation area of ​​the epoxy resin composition as the thermosetting resin composition, and its area was measured. The impregnation rate is expressed as the area of ​​the impregnated area of ​​the epoxy resin composition / (area of ​​the total area - area of ​​the area where the continuous reinforcing fiber bundles are present) × 100 (%).

[0228] The impregnation zone of the epoxy resin composition refers to the area where a thermosetting resin composition is impregnated between continuous carbon fibers or continuous glass fibers, and where air between the fibers is removed. That is, within the impregnation zone of the epoxy resin composition, there is a cured product of the thermosetting resin composition between the continuous carbon fibers or continuous glass fibers.

[0229] The ultra-deep color 3D shape measuring microscope uses the Keyence VK-9500 (control unit) / VK-9510 (measuring unit) system.

[0230] The determination of permeability shall be made according to the following criteria.

[0231] [Evaluation Criteria]

[0232] AA: Infiltration rate is 100%

[0233] A: The penetration rate is above 95% and less than 100%.

[0234] B: The penetration rate is above 90% and less than 95%.

[0235] C: Penetration rate less than 90%

[0236] Glass transition temperature (Tg)

[0237] The glass transition temperature (Tg) of the base resin (cured epoxy resin composition) of the fiber-reinforced composites obtained in each example was determined using a differential scanning calorimeter (DSC25 manufactured by TA INSTRUMENTS).

[0238] Under a nitrogen atmosphere, approximately 5 mg of a sample (cured epoxy resin composition) was subjected to a thermal process under the following conditions. The thermal process conditions were as follows: a first heating (heating rate of 10 °C / min), followed by cooling (cooling rate of 10 °C / min), and then a second heating (heating rate of 10 °C / min). The heating temperature was set from room temperature to 225 °C, and the peak temperature of the glass transition temperature observed during the second heating was recorded and is shown in Table 1. In examples using the same thermosetting resin composition, a higher Tg indicates a more thorough mixing of the main agent and curing agent in the thermosetting resin composition.

[0239] Manufacturing Example 1

[0240] (Preparation of epoxy resin curing agent solution B-1)

[0241] 1 mol of m-phenylenediamine (MXDA) was added to the reaction vessel. The mixture was heated to 60°C under a nitrogen atmosphere, and 0.93 mol of methyl acrylate was added dropwise over 1 hour. The generated methanol was distilled off while the temperature was raised to 165°C and maintained at 165°C for 2.5 hours, thus obtaining the reaction product of MXDA and methyl acrylate, i.e., an epoxy resin curing agent. Methanol was then added dropwise over 1.5 hours to obtain epoxy resin curing agent solution B-1, which consisted of 65% epoxy resin curing agent and 35% methanol.

[0242] Example 1 (Manufacturing and Evaluation of the Molded Article)

[0243] As the main component of the thermosetting resin composition, an epoxy resin with glycidyl amino groups derived from m-phenylenediamine (TETRAD-X manufactured by Mitsubishi Gas Chemical Co., Ltd.) was used. As the curing agent, epoxy resin curing agent solution B-1 obtained in Manufacturing Example 1 was used. As the continuous reinforcing fiber, carbon fiber roving "T700SC-12000" (filament number: 12000, fineness: 800 tex, cross-sectional shape of carbon fiber roving: elliptical) manufactured by Toray Industries, Ltd. was used.

[0244] On one side of the aforementioned carbon fiber roving, the main agent is first applied with a ratio of 1.2 (number of active amine hydrogens in the epoxy resin curing agent / number of epoxy groups in the epoxy resin) and a total solid content of 700 g / 1000 m. Then, the aforementioned curing agent solution B-1 is applied to the other side (Step (I)). The resulting roving is twisted circumferentially at 100 revolutions per m, then untwisted by rotating it 100 revolutions per m in the opposite direction, allowing the main agent and curing agent solution to impregnate and mix. Next, the remaining resin composition (main agent and curing agent solution) is removed using a pinch roller (twisting step). Finally, it is heated and dried in a hot air dryer at 60°C for 6 minutes to remove the solvent, yielding a tow prepreg (Step (II)).

[0245] The obtained fiber prepreg is configured into a spiral structure in a can shape and molded, and then heated and cured at 120°C for 1 hour to produce a molded body made of carbon fiber reinforced composite material (step (III)).

[0246] The resulting molded body was evaluated using the methods described above. The results are shown in Table 1.

[0247] It should be noted that the hydrogen permeability coefficient of the cured product of the mixture of the main agent and the curing agent solution (epoxy resin composition) used in Example 1, measured by the aforementioned method, is 3.9 × 10⁻⁶. -11 [cc·cm / (cm 2 ·s·cmHg)].

[0248] Example 2

[0249] In step (II) of Example 1, the twisting process was not performed. Otherwise, the molded articles were manufactured and evaluated using the same method as in Example 1. The results are shown in Table 1.

[0250] Example 3

[0251] In step (II) of Example 1, the untwisting and twisting processes were not performed. Otherwise, the molded articles were manufactured and evaluated using the same method as in Example 1. The results are shown in Table 1.

[0252] Example 4

[0253] In Example 1, a liquid epoxy resin ("jER828" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 186 g / equivalent) derived from bisphenol A and containing glycidyl groups was used as the main agent of the thermosetting resin composition, with a ratio of the number of active amine hydrogens in the epoxy resin curing agent to the number of epoxy groups in the epoxy resin being 1.0. 1,3-bis(aminomethyl)cyclohexane (1,3-BAC, manufactured by Mitsubishi Gas Chemical Corporation) was used as the curing agent. Otherwise, the molded articles were prepared and evaluated using the same method as in Example 1. The results are shown in Table 1.

[0254] Example 5

[0255] In Example 1, instead of carbon fiber roving, 16 strands of glass fiber roving manufactured by Nitto Boki Co., Ltd., entitled "E Glass Yarn ECG75 1 / 0 0.7Z" (filament diameter: 9.1 μm, filament count: 400, fineness: 68.7 tex, cross-sectional shape: round), were bundled together. Otherwise, the molded articles were manufactured and evaluated using the same method as in Example 1. The results are shown in Table 1.

[0256] Example 6

[0257] As the main component of the thermosetting resin composition, an epoxy resin with glycidyl amino groups derived from m-phenylenediamine (TETRAD-X manufactured by Mitsubishi Gas Chemical Co., Ltd.) was used; as the curing agent, epoxy resin curing agent solution B-1 obtained in Manufacturing Example 1 was used; and as the continuous reinforcing fiber, carbon fiber roving "T700SC-12000" manufactured by Toray Industries, Ltd. was used.

[0258] In step (I) of Example 2, the main agent and curing agent solution were mixed by collision before being applied to the carbon fiber roving. Otherwise, the molded article was manufactured and evaluated using the same method as in Example 2. This collision mixing was performed by feeding the main agent solution from the left and the curing agent solution from the right into a T-shaped feed tube (T-tube), and colliding the two at the branch point in the center of the T-tube. The mixture flowing from the bottom of the T-tube was then applied to the carbon fiber roving. The results are shown in Table 1. It should be noted that the pot life of the epoxy resin composition obtained by collision mixing of the main agent and curing agent solution was 10 minutes. This pot life was determined using the method described in the specification.

[0259] Comparative Example 1

[0260] In Example 1, step (II) was not performed. Otherwise, the molded articles were manufactured and evaluated using the same method as in Example 1. The results are shown in Table 1.

[0261] Comparative Example 2

[0262] As the main component of the thermosetting resin composition, an epoxy resin with glycidyl amino groups derived from m-phenylenediamine (TETRAD-X manufactured by Mitsubishi Gas Chemical Co., Ltd.) was used; as the curing agent, the epoxy resin curing agent solution B-1 obtained in Manufacturing Example 1 was used; and as the continuous reinforcing fiber bundle, carbon fiber roving "T700SC-12000" manufactured by Toray Industries, Ltd. was used.

[0263] In step (I) of Comparative Example 1, the above-mentioned main agent and curing agent solution were collided and mixed before being coated onto the carbon fiber roving. Otherwise, the molded article was manufactured and evaluated using the same method as in Comparative Example 1. The collision mixing was performed in the same manner as described in Example 6. The results are shown in Table 1.

[0264] Comparative Example 3

[0265] In Comparative Example 1, after process (I), a twisting process was performed using clamping rollers. Otherwise, the molded body was manufactured and evaluated using the same method as in Comparative Example 1. The results are shown in Table 1.

[0266] Table 1 shows the shape of the prepreg after process (II). "Elliptical cylinder" and "cylinder" refer to the cross-sectional shape of the prepreg, which is elliptical and circular respectively, perpendicular to the direction of travel of the tow prepreg. "Spiral cylinder" refers to the shape of the tow prepreg after twisting.

[0267] [Table 1]

[0268] Table 1

[0269]

[0270] As shown in Table 1, by sequentially implementing the manufacturing method of this embodiment, which includes steps (I) to (III) as specified in this invention, the impregnation of the thermosetting resin composition in the continuous reinforcing fiber bundle can be improved. Even when the main agent and curing agent constituting the thermosetting resin composition are supplied separately, they are thoroughly mixed within the continuous reinforcing fiber bundle, achieving a high Tg. In particular, by performing the untwisting and twisting steps in step (II), the impregnation of the thermosetting resin composition is further improved.

[0271] Industrial availability

[0272] According to the present invention, a manufacturing method is provided that enables the use of thermosetting resins or compositions with short pot life in the manufacture of molded articles formed from cured articles comprising thermosetting resins or thermosetting resin compositions and containing continuous reinforcing fiber bundles, and that improves the impregnation of thermosetting resins or compositions in continuous reinforcing fiber bundles; a resin impregnation apparatus suitable for the manufacturing method; and a 3D printer are provided.

[0273] According to the manufacturing method of the present invention, a pressure vessel without a liner can be easily manufactured. This pressure vessel is suitable as a high-pressure gas storage tank for vehicle use and is lightweight, thus improving fuel efficiency in the vehicle.

[0274] Explanation of reference numerals in the attached figures

[0275] 100 Pressure Vessel

[0276] 1. Cylindrical section

[0277] 1a, 1b Ends of the cylindrical section

[0278] 2a, 2b Rounded top

[0279] 3. Opening

[0280] 11 Continuously reinforced fiber bundles

[0281] 200 Resin Impregnation Device

[0282] 20 conveying rollers

[0283] Nozzles 21, 21a, and 21b

[0284] 22 Twisting Mechanism

[0285] Cans 23, 23a, and 23b

[0286] 24, 24a, 24b resin supply lines

[0287] 26 pinch rollers

[0288] 27. Drying mechanism

[0289] 300 robotic arms

[0290] 30 Support platform

[0291] 31 Arm

[0292] 32-layer stacked rollers

[0293] 33. Laminated Prepregs

[0294] 400 3D printer

Claims

1. A method for manufacturing a molded article, said molded article being formed from a cured product comprising a thermosetting resin composition and a fiber-reinforced composite material comprising continuous reinforcing fibers, said manufacturing method comprising the following steps (I) to (III) in sequence. Process (I): Coating process, in which a thermosetting resin composition is coated on the surface of a continuous reinforcing fiber bundle; Step (II): Resin impregnation step, after step (I), the continuous reinforcing fiber bundle is twisted to obtain a prepreg impregnated with the thermosetting resin composition; Step (III): Thermoforming step, in which the prepreg obtained in step (II) is prepared and then heated. The thermosetting resin composition is a two-component thermosetting resin composition containing a main agent (A) and a curing agent (B). The process (I) comprises the following steps: coating the surface of the continuous reinforcing fiber bundle with the main agent (A) or a composition thereof, and coating the surface of the continuous reinforcing fiber bundle with the curing agent (B) or a composition thereof, or The process (I) includes the following step: after mixing the main agent (A) or its composition with the curing agent (B) or its composition by collision, applying it to the surface of the continuous reinforcing fiber bundle. The main agent (A) is epoxy resin (A1), and the curing agent (B) is an epoxy resin curing agent (B1) comprising the reaction product (X) of the following components (x1) and (x2). (x1) Select at least one from the group consisting of m-phenylenediamine and p-phenylenediamine; (x2) Select at least one from the group consisting of unsaturated carboxylic acids and their derivatives represented by the following general formula (1). In equation (1), R 1 R 2 Each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 13 carbon atoms, or, The main agent (A) is an epoxy resin (A1), and the curing agent (B) is an epoxy resin curing agent that does not contain the reaction product (X). The epoxy resin curing agent is a polyamine compound or a modified form thereof. The polyamine compound is at least one selected from the group consisting of 1,2-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, isophorone diamine, o-phenylenediamine, m-phenylenediamine, and p-phenylenediamine.

2. The method for manufacturing a molded article according to claim 1, wherein, The process (II) includes a process of untwisting the continuous reinforcing fiber bundle after twisting it.

3. The method for manufacturing the molded article according to claim 1 or 2, wherein, The processes (I) and (II) are performed using a resin impregnation apparatus, the resin impregnation apparatus comprising: The mechanism for delivering the continuous reinforcing fiber bundle; A nozzle for spraying the thermosetting resin composition onto the surface of the continuous reinforcing fiber bundle; and A mechanism for twisting the continuous reinforcing fiber bundle.

4. The method for manufacturing a molded article according to claim 1 or 2, wherein, The molding method in process (III) is 3D printing.

5. The method for manufacturing a molded article according to claim 1 or 2, wherein, The pot life of the main agent (A) and the curing agent (B) after mixing is less than 10 minutes.

6. The method for manufacturing a molded article according to claim 1 or 2, wherein, The solvent content in the composition of the curing agent (B) is less than 40% by mass.

7. The method for manufacturing a molded article according to claim 1 or 2, wherein, The composition of the main agent (A) is solvent-free.

8. The method for manufacturing a molded article according to claim 1 or 2, wherein, The epoxy resin (A1) uses an epoxy resin with glycidyl amino groups derived from m-phenylenediamine as the main component.

9. The method for manufacturing a molded article according to claim 1 or 2, wherein, The molded body is a pressure vessel.

10. The method for manufacturing a molded article according to claim 9, wherein, The pressure vessel has no gasket.

11. A resin impregnation apparatus, comprising: A mechanism for delivering continuous reinforcing fiber bundles; A nozzle for spraying a thermosetting resin composition onto the surface of the continuous reinforcing fiber bundle; and The mechanism for twisting the continuous reinforcing fiber bundle. in, The resin impregnation apparatus performs steps (I) and (II) in the method for manufacturing the molded article according to any one of claims 1-10.

12. The resin impregnation apparatus according to claim 11, further comprising a drying mechanism.

13. A 3D printer equipped with the resin impregnation apparatus of claim 11 or 12.

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