Method for manufacturing a cured body, method for manufacturing a molded body

Abstract

The present invention provides a method for producing a cured resin composition that exhibits excellent moldability during curing and a high glass transition temperature, as well as a method for producing a molded article. [Solution] The method for manufacturing a cured body comprises a first heating step, in which the temperature T H1 Using a first heating section preheated to (°C), a resin composition in direct contact with the first heating section is heated, or a resin composition placed in the first heating section via a solid heat transfer medium is heated. The resin composition comprises a compound (A) having at least two epoxy groups in one molecule, an acid anhydride-based curing agent (B), and a curing accelerator (C), wherein the curing accelerator (C) comprises one or more selected from the group consisting of imidazole-based curing accelerators, amine-based curing accelerators, ammonium salt-based curing accelerators, phosphine-based curing accelerators, phosphonium salt-based curing accelerators, urea-based curing accelerators, and fatty acid salt-based curing accelerators. H1 The following equation is satisfied: T1-20≦T H1 ≤T1+20

Description

[Technical Field]

[0001] This invention relates to a method for manufacturing a cured article and a method for manufacturing a molded article. [Background technology]

[0002] Copper-clad laminates (CCLs) are known as printed circuit boards used for electrical connection / insulation between electronic components that make up a circuit, and for the mechanical arrangement / fixation of components. CCLs are obtained by impregnating glass fibers with a thermosetting resin composition containing epoxy resin or polyphenylene ether resin and a reactive curing agent to obtain a prepreg, which is a semi-cured resin sheet, and then stacking multiple sheets of this prepreg, sandwiching both sides with copper foil, and heat-pressing them together.

[0003] Styrene-maleic anhydride copolymer (SMA) is often used as a reactive curing agent due to its low dielectric loss. It is also known that styrene (St)-maleic anhydride (MAH)-N-phenylmaleimide (NPMI) copolymer can be used as a reactive curing agent (Patent Documents 1-2). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-169276 [Patent Document 2] Japanese Patent Publication No. 2009-197242 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, controlling the molding process during the curing of thermosetting resin compositions containing curing agents and curing accelerators was difficult, and the glass transition temperature of the cured product was sometimes insufficient.

[0006] This invention has been made in view of the above problems, and provides a method for producing a cured body that is excellent in moldability during curing of a thermosetting resin composition and in the glass transition temperature of the cured body, and a method for producing a molded body including the cured body. [Means for solving the problem]

[0007] As a result of diligent research to solve the above problems, the inventors of the present invention discovered that the above problems can be solved by the specific relationship between the formulation of the thermosetting resin composition and the manufacturing conditions, and thus completed the present invention.

[0008] In other words, the present invention provides the following invention. [1] A method for manufacturing a cured body, Equipped with a first heating step, In the previous heating step, the temperature T H1 Using the first heating section preheated to (°C), The resin composition in direct contact with the first heating element is heated, or The resin composition, which is placed in the first heating section via a solid heat transfer medium, is heated. The resin composition comprises a compound (A) having at least two epoxy groups in one molecule, an acid anhydride-based curing agent (B), and a curing accelerator (C). The curing accelerator (C) comprises one or more selected from the group consisting of imidazole-based curing accelerators, amine-based curing accelerators, ammonium salt-based curing accelerators, phosphine-based curing accelerators, phosphonium salt-based curing accelerators, urea-based curing accelerators, and fatty acid salt-based curing accelerators. Said T H1 The following equation (1) is satisfied, T1-20≦T H1 ≤T1+20 (1) In the above formula (1), T1 (°C) is the temperature represented by the following formula (2): T1(°C) = 184 × (Z / M × 100) -0.07 -40 (2) In formula (2) above, M (mol) is the amount of substance of the acid anhydride group in the resin composition, and Z (mol) is the amount of substance of the curing accelerator in the resin composition. Manufacturing method. [2] The manufacturing method according to [1], wherein the curing accelerator (C) comprises the imidazole-based curing accelerator. [3] The method for producing the acid anhydride-based curing agent (B) according to [1] or [2], comprising a copolymer (b1) having an acid anhydride monomer unit and an aromatic vinyl monomer unit. [4] The method for producing the copolymer (b1) according to [3], wherein the copolymer (b1) comprises the acid anhydride monomer unit, the aromatic vinyl monomer unit, and the maleimide monomer unit. [5] The copolymer (b1) has a maleimide monomer unit content of 5.0% by mass or more and less than 49.0% by mass when the total amount of monomer units contained in the copolymer (b1) is 100% by mass, according to the manufacturing method of [4]. [6] The method for producing the copolymer (b1) according to [4] or [5], wherein, when the total amount of monomer units contained in the copolymer (b1) is 100% by mass, the copolymer (b1) comprises 45.0 to 89.9% by mass of aromatic vinyl monomer units, 0.1 to 8.0% by mass of acid anhydride monomer units, 10.0 to 30.0% by mass of maleimide monomer units, and 0.0 to 20.0% by mass of other monomer units. [7] The reactive curing agent according to any one of [4] to [6], wherein the number of acid anhydride monomer units contained in each molecular chain of the copolymer (b1) is 2 to 25. [8] The reactive curing agent according to any one of [4] to [7], wherein the glass transition temperature of the copolymer (b1) is 125 to 200°C. [9] The weight-average molecular weight of the copolymer (b1) is 20,000 or more, the method of production according to any one of [4] to [8].

[10] Said T H1 The following equation (1A) is satisfied: T1-15≦T H1 ≤T1+15 (1A) The manufacturing method described in any one of [1] to [9].

[11] Said T H1satisfies the following formula (1B): T1 - 10 ≤ T H1 ≤ T1 + 10 (1B) The manufacturing method according to any one of [1] to

[10] .

[12] In the first heating step, the first heating part that directly contacts the resin composition heats the resin composition, and the first heating part is a mold. The manufacturing method according to any one of [1] to

[11] .

[13] In the first heating step, the first heating part heats the resin composition through a solid heat medium, and the solid heat medium is a metal foil. The manufacturing method according to any one of [1] to

[11] .

[14] Further includes a second heating step, In the second heating step, using a second heating part at a temperature T H2 (°C), heat the first cured body in direct contact with the second heating part, or heat the first cured body disposed via a solid heat medium with respect to the second heating part, The first cured body is the cured body obtained by the first heating step, The T satisfies the following formula (3) and the following formula (4): H2 T T H1 < T H2 (3) 120°C ≤ T H2 ≤ 200°C (4) The manufacturing method according to any one of [1] to

[13] .

[15] A manufacturing method of a molded body, including an impregnation step and a curing step, In the impregnation step, impregnate a reinforcing base material with a resin composition to form an impregnated base material, The curing step includes a first heating step, including a first heating step, In the first heating step, using a first heating part preheated to a temperature T H1 (°C), heat the impregnated base material in direct contact with the first heating part, or heat the impregnated base material in which the first heating part is disposed via a solid heat medium, heat the impregnated base material in which the first heating part is disposed via a solid heat medium, The resin composition comprises a compound (A) having at least two epoxy groups in one molecule, an acid anhydride-based curing agent (B), and a curing accelerator (C). The curing accelerator (C) comprises one or more selected from the group consisting of imidazole-based curing accelerators, amine-based curing accelerators, ammonium salt-based curing accelerators, phosphine-based curing accelerators, phosphonium salt-based curing accelerators, urea-based curing accelerators, and fatty acid salt-based curing accelerators. Said T H1 The following equation (1) is satisfied, T1-20≦T H1 ≤T1+20 (1) In the above formula (1), T1 (°C) is the temperature represented by the following formula (2): T1(°C) = 184 × (Z / M × 100) -0.07 -40 (2) In formula (2) above, M (mol) is the amount of substance of the acid anhydride group in the resin composition, and Z (mol) is the amount of substance of the curing accelerator in the resin composition. Manufacturing method.

[16] The curing step further comprises a second heating step, In the second heating step described above, the temperature is T H2 Using the second heating section which is (°C), The second heating element, which is in direct contact with the first molded body, heats the first molded body, or The first molded body, which is placed in the second heating section via a solid heat transfer medium, is heated. The first molded body is a molded body obtained by the first heating step, Said T H2 The following equations (3) and (4) are satisfied: T H1 <T H2 (3) 120℃≦T H2 ≤200℃ (4) The manufacturing method described in

[15] . [Modes for carrying out the invention]

[0009] <Explanation of Terms> In this specification, the description "A to B" means that it is greater than or equal to A and less than or equal to B.

[0010] Embodiments of the present invention will be described below. The various features shown in the embodiments below can be combined with each other. Furthermore, each feature can stand alone as an independent invention.

[0011] 1. Method for manufacturing the cured body A method for manufacturing a cured body according to one embodiment of the present invention (first embodiment) comprises a first heating step. The method for manufacturing a cured body may further comprise a second heating step. The second heating step is performed after the completion of the first heating step.

[0012] 1-1. 1st heating process In the first heating step, the temperature T H1 Using a first heating section preheated to (°C), the resin composition in direct contact with the first heating section is heated, or the resin composition placed in relation to the first heating section via a solid heat transfer medium is heated, thereby curing the resin composition.

[0013] The resin composition is at temperature T H1 It is heated using a first heating section that has been preheated to a temperature T H1 It is preheated to a temperature T at the point when the first heating unit starts heating the resin composition. H1 It is set to be such that the temperature T H1 By starting heating using a preheated first heating section, a cured body with excellent moldability during curing and a superior glass transition temperature can be obtained. H1 If the temperature is lower, the glass transition temperature is low, T H1 If the temperature is higher, the glass transition temperature is lower and the moldability is poor.

[0014] The first heating section is not particularly limited as long as it can heat the resin composition, but for example, it is a solid member having a heating surface. The heating surface is heated to a predetermined temperature (T) by a heat source provided in or outside the heating section. H1) can be controlled. The heating surface may be a smooth surface, or it may be a surface with irregularities such as a predetermined shape or pattern.

[0015] In one embodiment, the first heating element may heat the resin composition in direct contact with the first heating element. The first heating element may heat, for example, to a temperature T H1 Heating can be performed by bringing the heating surface of a preheated first heating section into contact with the resin composition. The first heating section is, for example, a mold. The resin composition can be heated and molded by methods such as pouring it into a preheated mold, pressing it using a preheated mold, or injection molding it using a preheated mold.

[0016] In one embodiment, the first heating unit may heat a resin composition that is placed relative to the first heating unit via a solid heat transfer medium. The first heating unit may heat, for example, to a temperature T H1 The heating surface of the preheated first heating section is brought into contact with a thin solid heat transfer medium with high thermal conductivity, thereby indirectly heating the resin composition in contact with the solid heat transfer medium. Examples of solid heat transfer mediums include metal foils such as copper foil and aluminum foil, and release films. The thickness of the solid heat transfer medium is, for example, 1 to 300 μm. The first heating section is, for example, a metal plate. In a specific example, two metal plates (multiple first heating sections), two copper foils (multiple solid heat transfer mediums), and a resin composition (one or more layers of thermoplastic resin composition) are arranged in the order of metal plate / copper foil / resin composition / copper foil / metal plate, and the resin composition can be heated via the copper foil by the metal plate acting as a heating section.

[0017] 1-1-1.Resin composition The resin composition is a thermosetting resin composition. The resin composition comprises a compound (A) having at least two epoxy groups in one molecule, an acid anhydride-based curing agent (B), and a curing accelerator (C).

[0018] <Compound (A)> Compound (A) is a compound having at least two epoxy groups in one molecule (epoxy compound). The epoxy compound is, for example, a polymer having at least two epoxy groups in one molecule (epoxy resin). The epoxy resin is not particularly limited, but examples include epoxidized polybutadiene resin, epoxy resin having a cyclohexyl group, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, fluorene type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, and modified products thereof. One or more of these epoxy resins may be selected and used. Among these, bisphenol A type epoxy resin and phenol novolac type epoxy resin are preferred in terms of dielectric properties and copper foil adhesion. The epoxy resin is a resin having reactive epoxy groups at one or both ends.

[0019] <Acid anhydride-based curing agent (B)> Acid anhydride-based curing agent (B) is a compound having an acid anhydride group. Acid anhydride-based curing agent (B) may contain two or more compounds having acid anhydride groups.

[0020] The acid anhydride-based curing agent (B) preferably comprises a copolymer (b1) having acid anhydride monomer units and aromatic vinyl monomer units. The copolymer (b1) preferably comprises acid anhydride monomer units, aromatic vinyl monomer units and maleimide monomer units. The acid anhydride-based curing agent (B) may contain two or more copolymers (b1) with different monomer unit contents. For example, the acid anhydride-based curing agent (B) may contain "a copolymer (b1a) having acid anhydride monomer units and aromatic vinyl monomer units, but not maleimide monomer units" and "a copolymer (b1b) having acid anhydride monomer units, aromatic vinyl monomer units and maleimide monomer units".

[0021] The acid anhydride-based curing agent (B) may contain a low molecular weight acid anhydride-based curing agent. Examples of low molecular weight acid anhydride-based curing agents include compounds with a molecular weight of 100 to 300, preferably compounds with a molecular weight of 150 to 190. Specific examples of low molecular weight acid anhydride-based curing agents include phthalic acid anhydrides such as 3 or 4-methyl-1,2,3,6-tetrahydrophthalic anhydride and methyl-3,6-endomethylene-1,2,3,6-tetrahydrophthalic anhydride; succinic acid anhydrides such as 2-octenyl succinic anhydride and 2-tetrapropenyl succinic anhydride; and so on. In one example, the acid anhydride-based curing agent (B) may contain a low molecular weight acid anhydride-based curing agent and a copolymer (b1).

[0022] <Acid anhydride monomer units> Examples of acid anhydride monomers derived from the acid anhydride monomer units contained in copolymer (b1) include unsaturated acid anhydride monomers such as maleic anhydride, itaconic anhydride, citraconic anhydride, and aconitic anhydride. Among these, maleic anhydride is preferred from the viewpoint of imparting curability to the resin composition containing the copolymer. Acid anhydride monomers may be used individually or in combination of two or more types.

[0023] The copolymer (b1) preferably contains 0.1 to 8.0% by mass of acid anhydride monomer units, more preferably 0.1 to 6.0% by mass, and even more preferably 0.1 to 4.0% by mass, when the total amount of monomer units contained in the copolymer (b1) is taken as 100% by mass. Specifically, for example, it is preferably 0.1, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 5.0, 6.0, 7.0, or 8.0% by mass, and may be within the range of any two of the values ​​exemplified here. If the acid anhydride monomer unit content is 0.1% by mass or more, the curability of the thermosetting resin composition containing copolymer (b1) is improved, and if it is 8.0% by mass or less, the thermal stability of copolymer (b1) and the hygroscopicity and thermal stability of the thermosetting resin composition containing copolymer (b1) are improved. The acid anhydride monomer unit content is 13 These values ​​were measured by 13C-NMR. When acid anhydride monomer units are used in combination, the content of unsaturated acid anhydride monomer units refers to the total amount of unsaturated acid anhydride monomer units used in combination.

[0024] <Aromatic vinyl monomer units> Aromatic vinyl monomers derived from aromatic vinyl monomer units contained in copolymer (b1) include, for example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, ethylstyrene, p-tert-butylstyrene, α-methylstyrene, and α-methyl-p-methylstyrene. Among these, styrene is preferred from the viewpoint of the copolymer's solubility in solvents such as methyl ethyl ketone (MEK). The aromatic vinyl monomers may be used individually or in combination of two or more types.

[0025] The copolymer (b1) preferably contains 45.0 to 89.9% by mass of aromatic vinyl monomer units, more preferably 55.0 to 85.0% by mass, and even more preferably 60.0 to 80.0% by mass, when the total amount of monomer units contained in copolymer (b1) is taken as 100% by mass. Specifically, for example, it is preferably 45.0, 50.0, 55.0, 60.0, 65.0, 70.0, 74.0, 76.0, 78.0, 80.0, 82.0, 84.0, 86.0, 88.0, or 89.9% by mass, and may be within the range of any two of the values ​​exemplified here. If the aromatic vinyl monomer unit content is 45.0% by mass or more, the solubility of the copolymer in solvents such as MEK is improved, and if it is 89.9% by mass or less, the copolymer can contain more maleimide monomer units, which can contribute to improved heat resistance, thus improving the heat resistance of the thermosetting resin composition containing the copolymer. The aromatic vinyl monomer unit content is, 13 These values ​​were measured by 13C-NMR. Furthermore, when aromatic vinyl monomer units are used in combination, the content of aromatic vinyl monomer units refers to the total amount of aromatic vinyl monomer units used in combination.

[0026] <Maleimide-based monomer units> Maleimide monomers derived from maleimide monomer units contained in copolymer (b1) include, for example, N-alkyl maleimides such as N-methylmaleimide, N-butylmaleimide, and N-cyclohexylmaleimide, and N-aryl maleimides such as N-phenylmaleimide, N-chlorophenylmaleimide, N-methylphenylmaleimide, N-methoxyphenylmaleimide, and N-tribromophenylmaleimide. Among these, N-aryl maleimide is preferred from the viewpoint of thermal stability of the copolymer, and N-phenylmaleimide is even more preferred. Maleimide monomers may be used individually or in combination of two or more types. To incorporate maleimide monomer units into a copolymer, for example, a copolymer obtained by copolymerizing a raw material consisting of acid anhydride monomer units with another monomer can be imidized with ammonia or a primary amine. Alternatively, a raw material consisting of maleimide monomers can be copolymerized with another monomer.

[0027] The copolymer (b1) contains 5.0% by mass or more and less than 49.0% by mass of maleimide monomer units, preferably 10.0 to 30.0% by mass, more preferably 14.0 to 28.0% by mass, and even more preferably 18.0 to 26.0% by mass, when the total amount of monomer units contained in the copolymer (b1) is taken as 100% by mass. Specifically, for example, it is preferably 5.0, 8.0, 10.0, 12.5, 15.0, 17.5, 20.0, 22.5, 25.0, 27.5, 30.0, 35.0, 40.0, 45.0, 48.0, or 48.9% by mass, and may be within the range of any two of the values ​​exemplified here. If the maleimide monomer unit content is 5.0% by mass or more, the heat resistance of the thermosetting resin composition containing the copolymer is improved, and if it is less than 49.0% by mass, the solubility of the copolymer in solvents such as MEK is improved. The maleimide monomer unit content is 13 These values ​​were measured by 13C-NMR. When maleimide monomer units are used in combination, the content of maleimide monomer units refers to the total amount of maleimide monomer units used in combination.

[0028] <Other monomer units> Copolymer (b1) may be copolymerized with other copolymerizable monomers other than acid anhydride monomers, aromatic vinyl monomers, and maleimide monomers, as long as they do not hinder the effects of the present invention. Examples of other copolymerizable monomers include vinyl cyanide monomers, acrylic acid ester monomers, methacrylic acid ester monomers, vinyl carboxylic acid monomers, acrylamides, and methacrylic acid amides. Among these, vinyl cyanide monomers and methacrylic acid ester monomers are preferred from the viewpoint of affinity with epoxy resins. Examples of vinyl cyanide monomers include acrylonitrile, methacrylonitrile, ethacrylonitrile, and fumaronitrile. Examples of acrylic acid ester monomers include methyl acrylic acid ester, ethyl acrylic acid ester, and butyl acrylic acid ester. Examples of methacrylate monomers include methyl methacrylate and ethyl methacrylate. Examples of vinyl carboxylic acid monomers include acrylic acid and methacrylic acid. Other monomers copolymerizable with the copolymer may be used individually or in combination of two or more types.

[0029] Such copolymerizable other monomers can be copolymerized to the extent that they do not impede the effects of the present invention. However, from the viewpoint of balancing affinity with epoxy resin and solubility in solvents such as MEK, it is preferable that the copolymer (b1) contains 0.0 to 20.0% by mass of other monomer units, more preferably 0.1 to 10.0% by mass, and even more preferably 0.5 to 5.0% by mass, when the total amount of monomer units contained in the copolymer (b1) is 100% by mass. Specifically, for example, it is preferable that the amount be 0.0, 0.5, 1.0, 2.0, 5.0, 10.0, 15.0, or 20.0% by mass, and it may be within the range of any two of the values ​​exemplified here. When other monomer units are included, the affinity with epoxy resin improves, and if the amount is 20.0% by mass or less, the solubility in solvents such as MEK improves. The content of other monomer units is 13These values ​​were measured by 13C-NMR. Furthermore, when other monomer units are used in combination, this refers to the total amount of those other monomer units used.

[0030] <Additives contained in acid anhydride-based curing agent (B)> The acid anhydride-based curing agent (B) may contain additives as described below, to the extent that they do not impair the effects of the present invention. After polymerization of copolymers such as copolymer (b1) contained in acid anhydride-based curing agent (B) is complete, the polymerization solution may optionally contain heat stabilizers such as hindered phenol compounds, lactone compounds, phosphorus compounds, and sulfur compounds, light stabilizers such as hindered amine compounds and benzotriazole compounds, lubricants, plasticizers, colorants, antistatic agents, and mineral oil. The amount of these additives is preferably less than 0.2 parts by mass per 100 parts by mass of the total monomer units. These additives may be used individually or in combination of two or more types.

[0031] <Copolymer Manufacturing> The polymerization mode of copolymers such as copolymer (b1) contained in the acid anhydride-based curing agent (B) can be, for example, solution polymerization or bulk polymerization. Solution polymerization is preferred from the viewpoint that a copolymer with a more uniform copolymer composition can be obtained by polymerization while performing additive addition, etc. The solvent for solution polymerization is preferably nonpolymerizable from the viewpoint that by-products are less likely to form and adverse effects are minimized. Examples include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and acetophenone; ethers such as tetrahydrofuran and 1,4-dioxane; aromatic hydrocarbons such as benzene, toluene, xylene, and chlorobenzene; N,N-dimethylformamide, dimethyl sulfoxide, and N-methyl-2-pyrrolidone. Methyl ethyl ketone and methyl isobutyl ketone are preferred from the ease of solvent removal during defoliation and recovery of the copolymer. The polymerization process can be a continuous polymerization, batch process, or semi-batch process.

[0032] The method for producing copolymers such as copolymer (b1) is not particularly limited, but is preferably obtained by radical polymerization, and the polymerization temperature is preferably in the range of 80 to 150°C. The polymerization initiator is not particularly limited, but for example, known azo compounds such as azobisisobutyronitrile, azobiscyclohexanecarbonilite, azobismethylpropionitrile, and azobismethylbutyronitrile, or known organic peroxides such as benzoyl peroxide, t-butyl peroxybenzoate, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexanoate, di-t-butyl peroxide, dicumyl peroxide, and ethyl-3,3-di-(t-butylperoxy)butyrate can be used, and one or more of these may be used in combination. From the viewpoint of controlling the polymerization reaction rate and polymerization rate, it is preferable to use azo compounds or organic peroxides with a 10-hour half-life of 70 to 120°C. The amount of polymerization initiator used is not particularly limited, but it is preferable to use 0.1 to 1.5% by mass per 100% by mass of total monomer units, and more preferably 0.1 to 1.0% by mass. If the amount of polymerization initiator used is 0.1% by mass or more, a sufficient polymerization rate can be obtained, which is preferable. If the amount of polymerization initiator used is 1.5% by mass or less, the polymerization rate can be suppressed, making it easier to control the reaction and obtain the target molecular weight.

[0033] Chain transfer agents can be used in the production of copolymers such as copolymer (b1). The chain transfer agents used are not particularly limited, but examples include n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, α-methylstyrene dimer, ethyl thioglycolate, limonene, and terpinolene. The amount of chain transfer agent used is not particularly limited as long as the target molecular weight is obtained, but it is preferably 0.01 to 2.0% by mass, and more preferably 0.1 to 1.5% by mass, based on 100% by mass of total monomer units. The target molecular weight can be easily obtained if the amount of chain transfer agent used is 0.01% to 1.2% by mass.

[0034] Methods for introducing maleimide monomer units into copolymer (b1) include copolymerization with maleimide monomers, acid anhydride monomers, aromatic vinyl monomers, and other monomers (direct method), or pre-polymerization with acid anhydride monomers, aromatic vinyl monomers, and other monomers, followed by a reaction of the unsaturated acid anhydride groups with ammonia or a primary amine to convert the unsaturated acid anhydride groups into maleimide monomer units (post-imidization method). The post-imidization method is preferable because it reduces the amount of residual maleimide monomers in the copolymer.

[0035] Primary amines used in the post-imidization method include, for example, alkylamines such as methylamine, ethylamine, n-propylamine, iso-propylamine, n-butylamine, n-pentylamine, n-hexylamine, n-octylamine, cyclohexylamine, and decylamine, as well as chlor- or brom-substituted alkylamines and aromatic amines such as aniline, toluidine, and naphthylamine. Among these, aniline and cyclohexylamine are preferred. These primary amines may be used individually or in combination of two or more. The amount of primary amine added is not particularly limited, but is preferably 0.7 to 1.1 molar equivalents, and more preferably 0.85 to 1.05 molar equivalents, relative to the unsaturated acid anhydride group. An amount of 0.7 molar equivalents or more relative to the unsaturated acid anhydride monomer units in the crude product raw material is preferred because it results in good thermal stability of the copolymer. An amount of 1.1 molar equivalents or less is preferred because it reduces the amount of primary amine remaining in the copolymer.

[0036] A catalyst may be used when introducing maleimide monomer units by post-imidation. The catalyst can improve the dehydration and ring-closing reaction in the reaction between ammonia or a primary amine and an unsaturated acid anhydride group, particularly in the reaction from an unsaturated acid anhydride group to a maleimide group. The type of catalyst is not particularly limited, but for example, a tertiary amine can be used. Examples of tertiary amines are not particularly limited, but include trimethylamine, triethylamine, tripropylamine, tributylamine, N,N-dimethylaniline, and N,N-diethylaniline. The amount of tertiary amine added is not particularly limited, but it is preferably 0.01 molar equivalents or more relative to the unsaturated acid anhydride group. The temperature of the imidation reaction in this invention is preferably 100 to 250°C, and more preferably 120 to 200°C. If the temperature of the imidation reaction is 100°C or higher, the reaction rate is sufficiently fast and is preferable from the viewpoint of productivity. If the temperature of the imidation reaction is 250°C or lower, it is preferable because it can suppress the deterioration of physical properties due to thermal degradation of the copolymer.

[0037] A known method can be used to remove volatile components such as the solvent used in solution polymerization and unreacted monomers from the solution of copolymer (b1) or other copolymers after solution polymerization or after post-imidization (devolatilization method). For example, a vacuum devolatilization tank with a heater or a devolatilization extruder with a vent can be used. The devolatilized molten copolymer is transferred to a granulation process, where it can be extruded in strand form from a porous die and processed into pellets using a cold-cut method, an air-hot-cut method, or a water-hot-cut method. The resulting pellets can be processed into a powder by a grinding process. Powdering the copolymer has the advantage of increasing the dissolution rate when incorporated into a thermosetting resin composition. If the weight-average molecular weight of the copolymer is reduced, the extruded copolymer may be recovered and ground into a powder without going through the pelletization process. There are no particular limitations on the grinding method, and known grinding techniques can be used. Suitable grinding devices include rotary blade grinders, turbo mill grinders, turbo disc mill grinders, turbo cutter grinders, jet mill grinders, impact grinders, hammer grinders, and vibratory grinders.

[0038] <Weight-average molecular weight (Mw) of copolymer (b1)> The weight-average molecular weight (Mw) of the copolymer (b1) is preferably 20,000 or more, and more preferably 20,000 or more and less than 90,000. Specifically, for example, it is preferably 20,000, 30,000, 40,000, 50,000, 60,000, 70,000, 80,000, or 89,000, and may be within the range of any two of the values ​​exemplified here. If the weight-average molecular weight (Mw) of the copolymer is 20,000 or more, the amount of chain transfer agent used in the polymerization step of the copolymer is reduced, and therefore the amount of VOCs contained in the resulting copolymer can be reduced. If it is less than 90,000, the solubility of the copolymer in solvents such as MEK can be improved. To control the weight-average molecular weight (Mw) of copolymer (b1), methods include adjusting the polymerization temperature, polymerization time, and amount of polymerization initiator added, as well as adjusting the solvent concentration and the amount of chain transfer agent added.

[0039] The weight-average molecular weight (Mw) of copolymer (b1) is a polystyrene-converted value measured by gel permeation chromatography (GPC), and can be measured, for example, under the following conditions. Device name: SYSTEM-21 Shodex (manufactured by Showa Denko Corporation) Column: Three PL gel MIXED-B columns in series Temperature: 40℃ Detection: Differential refractive index Solvent: tetrahydrofuran Concentration: 2% by mass Calibration curve: Prepared using standard polystyrene (PS) (manufactured by PL Co., Ltd.).

[0040] <Number-average molecular weight (Mn) of copolymer (b1)> The number-average molecular weight (Mn) of copolymer (b1) is preferably 10,000 to 40,000, and more preferably 20,000 to 40,000. Specifically, for example, it is preferably 1, 2, 3, or 40,000, and may be within the range of any two of the values ​​exemplified here. If the number-average molecular weight (Mn) of copolymer (b1) is 10,000 or more, the amount of chain transfer agent used in the polymerization step of the copolymer is reduced, thus reducing the amount of VOCs contained in the resulting copolymer. If it is 40,000 or less, the solubility of the copolymer in solvents such as MEK and the curability of the thermosetting resin composition containing the copolymer can be improved. To control the number-average molecular weight (Mn) of copolymer (b1), methods include adjusting the polymerization temperature, polymerization time, and amount of polymerization initiator added, as well as adjusting the solvent concentration and the amount of chain transfer agent added. The number-average molecular weight (Mn) of copolymer (b1) is a polystyrene-converted value measured by gel permeation chromatography (GPC), and can be measured, for example, under the same conditions as the weight-average molecular weight (Mw) described above.

[0041] <Number of acid anhydride monomer units per molecular chain of copolymer (b1)> The number of acid anhydride monomer units per molecular chain of copolymer (b1) is preferably 2 to 25, more preferably 3 to 16, and even more preferably 4 to 12. Specifically, the number of acid anhydride monomer units per molecular chain of copolymer (b1) is preferably 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 15, 20, or 25, and may be within the range of any two of the values ​​exemplified here. If the number of acid anhydride monomer units per molecular chain of copolymer (b1) is 2 or more, the curability of the thermosetting resin composition containing copolymer (b1) is improved, and if it is 25 or less, the balance between the thermal decomposition properties of copolymer (b1) and the curability of the thermosetting resin composition containing copolymer (b1) is improved. To control the number of acid anhydride monomer units per molecular chain of copolymer (b1), methods such as adjusting the acid anhydride monomer unit content in copolymer (b1) or the number-average molecular weight (Mn) of the copolymer can be used.

[0042] The number of acid anhydride monomer units (N) per molecular chain of copolymer (b1) can be calculated using the following formula (1) from the content of unsaturated acid anhydride monomer units in the copolymer (A, unit: mass%), when the total amount of monomer units contained in the copolymer is taken as 100% by mass, and the number-average molecular weight (Mn) of the copolymer. N=(A / 100)×Mn / 98 Formula (1)

[0043] <Glass transition temperature Tg of copolymer (b1)> The glass transition temperature (Tg) of copolymer (b1) is preferably 125°C to 200°C, more preferably 130°C to 190°C, and even more preferably 135°C to 180°C. Specifically, for example, it is preferably 125, 130, 135, 140, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, or 200°C, and may be within the range of any two of the values ​​exemplified here. If the glass transition temperature (Tg) of the copolymer is 125°C or higher, the heat resistance of the thermosetting resin composition containing the copolymer is improved, and if it is 200°C or lower, the solubility of the copolymer in solvents such as MEK can be improved. The glass transition temperature (Tg) of copolymer (b1) can be controlled, for example, by adjusting the content of maleimide monomer units contained in copolymer (b1) or the weight-average molecular weight of copolymer (b1).

[0044] The glass transition temperature is the intermediate glass transition temperature (Tmg) measured by DSC in accordance with JIS K-7121, and is the measured value under the measurement conditions described below. Device name: Seiko Instruments Inc. Robot DSC6200 Heating rate: 10°C / min

[0045] <Amount of residual aromatic vinyl monomers in copolymer (b1)> The amount of residual aromatic vinyl monomers in copolymer (b1) is preferably 0 to 500 ppm, more preferably 0 to 400 ppm, and even more preferably 0 to 300 ppm. Specifically, for example, it is preferably 1, 50, 100, 150, 200, 250, 300, 350, 400, 450, or 50 ppm or less. If the amount of residual aromatic vinyl monomers in copolymer (b1) is 500 ppm or less, the amount of VOCs contained in copolymer (b1) can be reduced. The amount of residual aromatic vinyl monomers in copolymer (b1) is measured under the following conditions after pretreatment, which involves weighing 0.3-0.4 g of copolymer (b1) into a 50 mL Erlenmeyer flask, dissolving it in 10 mL of DMF containing an internal standard (cyclopentanol), and then measuring the amount of residual aromatic vinyl monomers in copolymer (b1). Device name: GC-12A (manufactured by Shimadzu Corporation) Detector: FID Column: 3m glass column (packing material: liquid phase PEG20M + TCEP (15 + 5)) Temperature: INJ 150℃, DET 150℃, Column 115℃ Injection volume: 1μL The amount of residual aromatic vinyl monomers in copolymer (b1) can be reduced, for example, by reducing the amount of chain transfer agent in the polymerization process.

[0046] <Amount of residual maleimide monomer in copolymer (b1)> The amount of residual maleimide monomers in copolymer (b1) is preferably 0 to 500 ppm, more preferably 0 to 400 ppm, and even more preferably 0 to 300 ppm. Specifically, for example, it is preferably 1, 50, 100, 150, 200, 250, 300, 350, 400, 450, or 500 ppm or less. If the amount of residual maleimide monomers in copolymer (b1) is 500 ppm or less, the amount of VOCs contained in the copolymer can be reduced. The amount of residual maleimide monomer in copolymer (b1) is measured under the following conditions. Device name: GC-2010 (manufactured by Shimadzu Corporation) Column: Capillary column DB-5MS (phenylalene polymer) Temperature: Inlet 280°C, Detector 280°C The analysis is performed with a column temperature of 80°C (initial). (Temperature-based analysis conditions) 80℃: Hold for 12 minutes 80-280℃: Heat at a rate of 20℃ / min for 10 minutes 280℃: Hold for 10 minutes Detector: FID Procedure: Dissolve 0.5 g of the sample in 5 ml of 1,2-dichloroethane solution (0.014 g / L) containing undecane (internal standard). Then, add 5 ml of n-hexane and shake with a shaker for 10-15 minutes to precipitate. After the polymer has precipitated, inject only the supernatant into the GC. From the peak area of ​​the obtained monomer, calculate the quantitative value using the coefficient obtained from the internal standard. The amount of residual maleimide monomer in copolymer (b1) can be reduced, for example, by employing a post-imidization method in the production of copolymer (b1).

[0047] <Curing accelerator (C)> The curing accelerator (C) comprises one or more selected from the group consisting of imidazole-based curing accelerators, amine-based curing accelerators, ammonium salt-based curing accelerators, phosphine-based curing accelerators, phosphonium salt-based curing accelerators, urea-based curing accelerators, and fatty acid metal salts. These can be used individually or in combination of two or more. The curing accelerator (C) preferably comprises an imidazole-based curing accelerator.

[0048] Imidazole-based curing accelerators are compounds having an imidazole skeleton. Imidazole-based curing accelerators are, for example, compounds having a structure represented by the following general formula (i).

[0049] [ka]

[0050] In general formula (i), R 1 R is a hydrogen atom or a monovalent organic group (first organic group). The first organic group is, for example, a linear, branched, or cyclic alkyl group which may have a substituent (1 substituent). The number of carbon atoms in the first organic group is, for example, 1 to 10, preferably 1 to 4. The first substituent is, for example, a cyano group, a phenyl group, a 2,6-diaminotriazinyl group, etc. 1 This is preferably a hydrogen atom or a propionitrile group. R 2This is a monovalent organic group (second organic group). The second organic group is, for example, a linear, branched, or cyclic alkyl group (second alkyl group) which may have a substituent (second substituent). The number of carbon atoms in the second organic group is, for example, 1 to 10, preferably 1 to 4. The second substituent is, for example, a cyano group, a phenyl group, a 2,6-diaminotriazinyl group, etc. 2 Preferably, this is a methyl group or an ethyl group. R 4 R is a hydrogen atom or a monovalent organic group (quaternary organic group). The quaternary organic group is, for example, a linear, branched, or cyclic alkyl group (quaternary alkyl group) which may have a substituent (quaternary substituent). The number of carbon atoms in the quaternary organic group is, for example, 1 to 5, preferably 1 to 2. The quaternary substituent is, for example, a cyano group, a phenyl group, a 2,6-diaminotriazinyl group, etc. 4 Preferably, this is a hydrogen atom or a methyl group. R 5 R is a hydrogen atom or a monovalent organic group (fifth organic group). 5 Preferably, it is a hydrogen atom.

[0051] Examples of imidazole-based curing accelerators include 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, and bisphenol A bis{3-(2-phenyl)imidazolyl-2-hydroxypropyl} ether. These can be used individually or in combination of two or more.

[0052] The amine-based curing accelerator is an amine compound (excluding those having the imidazole skeleton described above). The amine-based curing accelerator is, for example, a primary amine, a secondary amine, or a tertiary amine, and is preferably a tertiary amine. The amine-based curing accelerator may be a heterocyclic compound, a polycyclic compound, or a heterocyclic and polycyclic compound (a polycyclic heterocyclic compound).

[0053] Examples of amine-based curing accelerators include triethylamine, DBU (1,8-diazabicyclo[5.4.0]-7-undecene), and DBN (1,5-diazabicyclo[4.3.0]-5-nonene). These can be used individually or in combination of two or more.

[0054] Ammonium salt-based curing accelerators are salts of the amine compounds of the amine-based curing accelerators described above. Examples of amine-based curing accelerators include salts of triethylamine, DBU (1,8-diazabicyclo[5.4.0]-7-undecene), and DBN (1,5-diazabicyclo[4.3.0]-5-nonene) (e.g., phenol salts, octylates, p-toluenesulfonates, formates, o-phthalates, phenol novolac resin salts, etc.), and boron trifluoride monoethylamine. These can be used individually or in combination of two or more.

[0055] Phosphine-based curing accelerators are trivalent phosphorus compounds.

[0056] Examples of phosphine-based curing accelerators include triphenylphosphine. These can be used individually or in combination of two or more.

[0057] Phosphonium salt-based hardening accelerators are pentavalent phosphates.

[0058] Examples of phosphonium salt-based curing accelerators include tetraphenylphosphonium-tetraphenylborate, tetra-n-butylphosphonium bromide, and bis(tetra-n-butylphosphonium) pyromelitate. These can be used individually or in combination of two or more.

[0059] Urea-based curing accelerators are urea compounds.

[0060] Examples of urea-based curing accelerators include 3-phenyl-1,1'-dimethylurea and 3-(3,4-dichlorophenyl)-1,1-dimethylurea. These can be used individually or in combination of two or more.

[0061] Fatty acid salt-based hardening accelerators are fatty acid salts such as fatty acid metal salts.

[0062] Examples of fatty acid metal salts include tin octoate and zinc naphthenate. These can be used individually or in combination of two or more.

[0063] <Solvent> The resin composition may contain a solvent such as an organic solvent. Examples of organic solvents include ketones such as MEK, cyclohexanone, and methyl isobutyl ketone.

[0064] <Other ingredients> The resin composition may contain cyanate resin and other resins such as bismaleimide resin as resin components, to the extent that they do not impair the effects of the present invention. Furthermore, the resin composition may contain additives as needed, to the extent that they do not impair the effects of the present invention.

[0065] The resin composition may contain elastomers such as butadiene rubber, isoprene rubber, acrylate rubber, graft copolymers containing these, and hydrogenated graft copolymers, to the extent that it does not impair the effects of the present invention. By including such rubbers and elastomers, it is possible to suppress the peeling of the cured resin composition from the metal foil.

[0066] <Additives> For the purpose of imparting flame retardancy to the resin composition and its cured product, flame retardants such as phosphate ester-based flame retardants like tricresyl phosphate and triphenyl phosphate, and inorganic substances such as red phosphorus, antimony trioxide, aluminum hydroxide, and magnesium hydroxide may be added within a range that does not impair the effects of the present invention. Furthermore, inorganic fillers such as silica, mica, talc, glass short fibers, glass fine powder, and hollow glass may be incorporated to reduce the coefficient of thermal expansion and increase the modulus of elasticity, within limits that do not impair the effects of the present invention.

[0067] <Manufacturing of resin compositions> The resin composition can be obtained by mixing compound (A), an acid anhydride-based curing agent (B), a curing accelerator (C), and other necessary resins and additives. Alternatively, it may be obtained by dissolving compound (A), an acid anhydride-based curing agent (B), a curing accelerator (C), and other necessary resins and additives in an organic solvent and mixing them.

[0068] 1-1-2.Heating conditions <Heating temperature> Temperature T of the first heating section H1 (°C) is the temperature that satisfies the following equation (1). T1-20≦T H1 ≤T1+20 (1)

[0069] In equation (1), T1 (°C) is the temperature represented by the following equation (2). T1(°C) = 184 × (Z / M × 100) -0.07 -40 (2)

[0070] In formula (2), M (mol) is the amount of substance of acid anhydride groups in the resin composition, and Z (mol) is the amount of substance of the curing accelerator in the resin composition.

[0071] The acid anhydride groups in the resin composition are, for example, the acid anhydride groups contained in acid anhydride monomer units of a copolymer (b1) of an acid anhydride-based curing agent (B). If a molecule contains multiple acid anhydride groups, the amount of substance of the acid anhydride groups is calculated based on the number of acid anhydride groups contained in that molecule. For example, if a molecule contains one acid anhydride group, the amount of substance of that molecule is taken as the amount of substance of the acid anhydride groups. If the polymer contains acid anhydride monomer units, the amount of substance of the acid anhydride groups is taken by multiplying the amount (mass) of the polymer by the content of acid anhydride monomer units in the polymer and dividing the result by the molecular weight (g / mol) of the acid anhydride monomer units. If the resin composition contains multiple types of compounds containing acid anhydride groups, the sum of the amounts of substance of the acid anhydride groups calculated from each of them is taken as M (mol) in formula (2).

[0072] If the resin composition contains multiple types of curing accelerators, the sum of the amounts of substance of each curing accelerator calculated from them shall be Z (mol) in equation (2).

[0073] T H1 Preferably satisfies the following formula (1A), and more preferably satisfies the following formula (1B). T1-15≦T H1 ≤T1+15 (1A) T1-10≦T H1 ≤T1+10 (1B)

[0074] T H1 For example, T1-20, T1-19, T1-18, T1-17, T1-16, T1-15, T1-14, T1-13, T1-12, T1-11, T1-10, T1-9, T1-8, T1-7, T1-6, T1-5, T1-4, T1-3, T1-2, T1-1, T1, T1+1, T1+2, T1+ These are T1+4, T1+5, T1+6, T1+7, T1+8, T1+9, T1+10, T1+11, T1+12, T1+13, T1+14, T1+15, T1+16, T1+17, T1+18, T1+19, and T1+20 (°C), and may be within the range of any two of the temperatures exemplified here.

[0075] The heating in the first heating step is performed at a temperature TH1 The heating process is initiated by a first heating section preheated to (°C). However, during the subsequent heating process (or for a predetermined heating time), the first heating section may be temperature-controlled to maintain a constant temperature, or the first heating section may be controlled to heat while changing within the range that satisfies the above formula (1). When the second heating process is carried out, the temperature of the first heating section is set to T H1 From T H2 The temperature may be increased at a predetermined rate.

[0076] <Cooking time> In the first heating step, the temperature T H1 The resin composition is heated using the first heating section for, for example, 10 seconds to 600 minutes, preferably 5 minutes to 250 minutes.

[0077] 1-2.Second heating process In the second heating step, the temperature T H2 Using a second heating section at (°C), the first cured body in direct contact with the second heating section is heated, or the first cured body placed relative to the second heating section via a solid heat transfer medium is heated. The first cured body is the cured body obtained in the first heating step. If the cured body obtained in the first heating step is a further curable semi-cured body (an intermediate cured product which is a further curable thermoplastic resin composition), it can be further cured in the second heating step to obtain a second cured body.

[0078] The first cured body has a temperature T H2 The heating is performed using a second heating section. In the second heating step, the second heating section is heated to a temperature T H2 It is preheated, and at the point when the heating of the first hardened body by the second heating section begins, the temperature T H2 It may be set to be such. The second heating section is at a temperature T at the time the second heating section starts heating the first hardened body. H2 A lower temperature, and during heating, temperature T H2 It may be set to be such.

[0079] The second heating section may be a different heating section from the first heating section, or it may be the same heating section. If it is the same heating section, T H1 The temperature of the first heating section may be increased and used as a second heating section.

[0080] The second heating section is not particularly limited as long as it can heat the first hardened body, but for example, it is a solid member having a heating surface. The heating surface is heated to a predetermined temperature (T) by a heat source provided in or outside the heating section. H2 ) can be controlled. The heating surface may be a smooth surface, or it may be a surface with irregularities such as a predetermined shape or pattern.

[0081] In one embodiment, the second heating element may heat the first cured body that is in direct contact with the second heating element. The second heating element may heat, for example, to a temperature T H2 Heating can be performed by bringing the heating surface of the second heating section, which has been preheated to a certain temperature, into contact with the first hardened body. The second heating section can also be heated to, for example, a temperature T H2 The heating surface of the second heating section, which is below a certain temperature, is brought into contact with the first cured body, and then the temperature T is raised. H2 The temperature can be raised to a certain level for heating. The second heating section is, for example, a mold. The first cured body obtained by pouring the resin composition into a mold and heating it in the first heating step, the first cured body obtained by pressing and heating it using a mold in the first heating step, the first cured body obtained by injection molding and heating it using a mold in the first heating step, etc., can be further cured by further heating.

[0082] In one embodiment, the second heating section may heat the first cured body which is placed relative to the second heating section via a solid heat transfer medium. The second heating section may heat, for example, at a temperature T H2 The heating surface of the preheated second heating section is brought into contact with a thin, solid heat transfer medium with high thermal conductivity, thereby indirectly heating the first hardened body that is in contact with the solid heat transfer medium. The second heating section is, for example, heated to temperature T H2 The heating surface of the second heating section, which is below a certain temperature, is brought into contact with a thin solid heat transfer medium with high thermal conductivity, and then the temperature is raised to T H2The first cured body, which is in contact with a solid heat transfer medium, can be indirectly heated by raising the temperature to a certain level. The solid heat transfer medium is, for example, a metal foil such as copper foil or aluminum foil, or a release film. The thickness of the solid heat transfer medium is, for example, 1 to 300 μm. The second heating section is, for example, a metal plate. In a specific example, two metal plates (multiple first heating sections), two copper foils (multiple solid heat transfer mediums), and a first cured body (one or more layers of first cured body) are arranged in the order of metal plate / copper foil / first cured body / copper foil / metal plate, and the first cured body can be heated by the metal plate as a heating section via the copper foil.

[0083] 1-2-1. Heating conditions <Heating temperature> Temperature T of the second heating section H2 (°C) is the temperature that satisfies the following equations (3) and (4). T H1 <T H2 (3) 120℃≦T H2 ≤200℃ (4)

[0084] T H2 For example, these values ​​could be 120, 130, 140, 150, 160, 170, 180, 190, or 200°C, and may also be within the range of any two of the values ​​exemplified here.

[0085] <Cooking time> In the second heating step, the temperature T H2 The first cured body is heated using the second heating section for, for example, 10 seconds to 600 minutes, preferably 10 minutes to 480 minutes. The heating time is, for example, T H2 Less than T H2 This is the time during which heating by the second heating section is performed after reaching a certain point.

[0086] 1-3.Drying process The method for manufacturing the cured product may further include a drying step. The drying step is performed before the first heating step. If the resin composition contains a solvent, the drying step may involve, for example, evaporating the solvent from the resin composition by applying hot air in a heating furnace at 50 to 200°C, or by evaporating the solvent from the resin composition in a vacuum dryer at 50 to 200°C. The drying time is, for example, 10 seconds to 600 minutes.

[0087] 2. Method for manufacturing molded articles A method for manufacturing a molded article according to one embodiment of the present invention (second embodiment) comprises an impregnation step and a curing step.

[0088] 2-1. Impregnation process In the impregnation process, the reinforcing substrate is impregnated with a resin composition to form an impregnated substrate. Impregnation can be carried out, for example, by immersing the reinforcing substrate in a resin composition in a container, or by passing it through a resin composition in a container.

[0089] The impregnation step may further include a drying step for drying the impregnated substrate. If the resin composition contains a solvent, in the drying step, for example, hot air may be applied to the impregnated substrate in a heating furnace at 50 to 200°C to evaporate the solvent of the resin composition, or the impregnated substrate may be placed in a vacuum dryer at 50 to 200°C to evaporate the solvent of the resin composition. The drying time is, for example, 10 seconds to 600 minutes. When manufacturing a copper-clad laminate prepreg as a molded body, the impregnated substrate becomes, for example, a prepreg, and the prepreg is preferably produced through a drying step.

[0090] 2-1-1. Reinforcement base material Examples of reinforcing materials include glass fiber substrates such as glass fiber cloth and glass fiber nonwoven fabric, and organic nonwoven fabrics. When manufacturing copper-clad laminates as molded articles, for example, glass fiber substrates can be used.

[0091] 2-1-2.Resin composition As the resin composition used in this embodiment, the resin composition described in the first embodiment ("1-1-1. Resin Composition") can be used.

[0092] 2-2.Curing process The curing process comprises a first heating step. The curing process may further comprise a second heating step.

[0093] 2-2-1. First heating step In the first heating step, the temperature T H1 Using a first heating unit preheated to (°C), the impregnated substrate in direct contact with the first heating unit is heated, or the impregnated substrate in which the first heating unit is arranged via a solid heat transfer medium is heated.

[0094] The impregnated substrate is heated to a temperature T H1 It is heated using a first heating section that has been preheated to a temperature T H1 It is preheated to a temperature T at the point when the first heating unit starts heating the impregnated substrate. H1 It is set to be such. In the first heating step, preferably the first heating section maintains a temperature T from the start of heating to the end of heating. H1 It is maintained at temperature T. H1 By starting heating using a preheated first heating section, a molded article containing a cured body with excellent moldability during curing and a good glass transition temperature can be obtained. H1 If the temperature is lower, the glass transition temperature is low, T H1 If the temperature is higher, the glass transition temperature is lower and the moldability is poor.

[0095] The first heating section is not particularly limited as long as it can heat the impregnated substrate, but for example, it is a solid member having a heating surface. The heating surface is heated to a predetermined temperature (T) by a heat source provided in or outside the heating section. H1 ) can be controlled. The heating surface may be a smooth surface, or it may be a surface with irregularities such as a predetermined shape or pattern.

[0096] In one embodiment, the first heating unit may heat the impregnated substrate that is in direct contact with the first heating unit. The first heating unit may heat, for example, to a temperature T H1Heating can be performed by bringing the heating surface of the preheated first heating section into contact with the impregnated substrate. The first heating section is, for example, a mold. Heating and molding can be performed by methods such as pressing using the preheated mold.

[0097] In one embodiment, the first heating unit may heat the impregnated substrate which is placed relative to the first heating unit via a solid heat transfer medium. The first heating unit may heat, for example, at a temperature T H1 The heating surface of the preheated first heating section is brought into contact with a thin solid heat transfer medium with high thermal conductivity, thereby indirectly heating the impregnated substrate in contact with the solid heat transfer medium. Examples of solid heat transfer mediums include metal foils such as copper foil and aluminum foil, and release films. The thickness of the solid heat transfer medium is, for example, 1 to 300 μm. The first heating section is, for example, a metal plate. In a specific example, two metal plates (multiple first heating sections), two copper foils (multiple solid heat transfer mediums), and an impregnated substrate (one or more layers of impregnated substrate) are arranged in the order of metal plate / copper foil / resin composition / copper foil / metal plate, and the impregnated substrate can be heated via the copper foil by the metal plate acting as a heating section.

[0098] 2-2-1-1. Heating conditions The heating conditions in the first heating step of this embodiment, including the heating temperature and heating time, can be appropriately used from the heating conditions described in the first embodiment ("1-1-2. Heating Conditions").

[0099] 2-2-2.Second heating process In the second heating step, the temperature is T H2 Using a second heating section at (°C), the second heating section, which is in direct contact with the first molded body, heats the first molded body, or the first molded body is heated with a solid heat transfer medium in between the second heating section and the second heating section. The first molded body is the molded body obtained in the first heating step. If the cured material contained in the molded body obtained in the first heating step is a further curable semi-cured material (an intermediate cured material which is a further curable thermoplastic resin composition), it can be further cured in the second heating step to obtain a second molded body.

[0100] The first molded body is heated to temperature TH2 It is heated using a second heating unit. In the second heating step, the second heating unit is preheated to a temperature T H2 and may be set to be at temperature T H2 when starting to heat the first molded body by the second heating unit. The second heating unit has a temperature lower than T H2 at the time of starting to heat the first molded body by the second heating unit, and may be set to reach temperature T H2 during heating.

[0101] The second heating unit may be a heating unit different from the first heating unit or the same heating unit. In the case of the same heating unit, the temperature of the first heating unit, which is T H1 at the end of heating in the first heating step, may be raised and used as the second heating unit.

[0102] The second heating unit is not particularly limited as long as it can heat the first molded body. For example, it is a solid member having a heating surface. The heating surface can be controlled to a predetermined temperature (T H2 ) by a heating source provided in the heating unit or outside the heating unit. The heating surface may be a smooth surface or a surface having irregularities such as a predetermined shape or pattern.

[0103] In one aspect, the second heating unit may heat the first molded body that is in direct contact with the second heating unit. For example, the second heating unit can perform heating by bringing the heating surface of the second heating unit preheated to temperature T H2 into contact with the first molded body. Also, for example, the second heating unit can bring the heating surface of the second heating unit at a temperature lower than T H2 into contact with the first molded body and then raise the temperature to T H2 to perform heating. The second heating unit is, for example, a mold or the like. By further heating the first molded body obtained by pressing and heating using a mold in the first heating step, it can be further cured.

[0104] In one embodiment, the second heating unit may heat the first molded body which is placed relative to the second heating unit via a solid heat transfer medium. The second heating unit may heat, for example, at a temperature T H2 The heating surface of the preheated second heating section is brought into contact with a thin, solid heat transfer medium with high thermal conductivity, thereby indirectly heating the first molded body that is in contact with the solid heat transfer medium. The second heating section is, for example, heated to temperature T H2 The heating surface of the second heating section, which is below a certain temperature, is brought into contact with a thin solid heat transfer medium with high thermal conductivity, and then the temperature is raised to T H2 The first molded body, which is in contact with a solid heat transfer medium, can be indirectly heated by raising its temperature to a certain level. The solid heat transfer medium is, for example, a metal foil such as copper foil or aluminum foil, or a release film. The thickness of the solid heat transfer medium is, for example, 1 to 300 μm. The second heating section is, for example, a metal plate. In a specific example, two metal plates (multiple first heating sections), two copper foils (multiple solid heat transfer mediums), and a first molded body (a first molded body with one or more layers) are arranged in the order of metal plate / copper foil / first molded body / copper foil / metal plate, and the first molded body can be heated by the metal plates as heating sections via the copper foil.

[0105] 2-2-2-1. Heating conditions The heating conditions in the second heating step of this embodiment, including the heating temperature and heating time, can be appropriately used from the heating conditions described in the first embodiment ("1-2-1. Heating Conditions"). [Examples]

[0106] The details will be explained below using examples, but the present invention is not limited to the following examples. Note that St may represent styrene, AN may represent acrylonitrile, NPMI may represent N-phenylmaleimide, MAH may represent maleic anhydride, and MEK may represent methyl ethyl ketone.

[0107] <<Ingredients>> The components used in the examples and comparative examples will be explained below.

[0108] <Epoxy compound (A)> • A-1: ​​Bisphenol A type epoxy resin (jER 828US, manufactured by Mitsubishi Chemical Corporation) [Number of epoxy groups per molecule: 2] • A-2: Phenol novolac type epoxy resin (jER 152, manufactured by Mitsubishi Chemical Corporation) [Number of epoxy groups per molecule: 2 or more]

[0109] <Acid anhydride-based curing agent (B)> B-1: Prepared by synthesizing as shown below. 83 parts by mass of styrene, 1 part by mass of maleic anhydride, 2.0 parts by mass of α-methylstyrene dimer, and 26 parts by mass of methyl ethyl ketone were charged into an autoclave with a volume of approximately 120 liters equipped with a stirrer. After replacing the gas phase with nitrogen gas, the temperature was raised to 92°C over 40 minutes while stirring. While maintaining the temperature at 92°C, a solution of 16 parts by mass of maleic anhydride and 0.6 parts by mass of t-butyl peroxy-2-ethylhexanoate dissolved in 78 parts by mass of methyl ethyl ketone was continuously added over 5 hours. After the addition was complete, the temperature was raised to 120°C and the reaction was carried out for 1 hour to complete the polymerization. Subsequently, 15 parts by mass of aniline and 0.3 parts by mass of triethylamine were added to the polymerization solution and the reaction was carried out at 140°C for 6 hours. The imidization reaction solution after the reaction was put into a vented screw extruder, and volatile components were removed to obtain pelletized copolymer. The obtained pellets were pulverized using a rotary impeller to obtain powdered copolymer (B-1). As described below 13 Compositional analysis of copolymer (B-1) by 13C-NMR revealed that it contained 74.0% by mass of styrene, 23.0% by mass of N-phenylmaleimide, and 3.0% by mass of maleic anhydride. The weight-average molecular weight was 32,000, the number of acid anhydride monomer units per molecular chain of the copolymer was 5, and the glass transition temperature was 155°C. The residual styrene monomer content was 300 ppm, and the residual N-phenylmaleimide monomer content was 180 ppm.

[0110] <Composition analysis> The compositional analysis of copolymer (B-1) is as follows: 13 Measurements were taken using the 1C NMR method under the measurement conditions described below. Instrument name: FT-NMR AVANCE300 (manufactured by BRUKER) Solvent: Deuterated chloroform Concentration: 14% by mass Temperature: 27℃ Total number of times: 8000

[0111] <Weight-average molecular weight (Mw) and number-average molecular weight (Mn)> The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of copolymer (B-1) are polystyrene-converted values ​​measured by gel permeation chromatography (GPC) under the following conditions. Device name: SYSTEM-21 Shodex (manufactured by Showa Denko Corporation) Column: Three PL gel MIXED-B columns in series Temperature: 40℃ Detection: Differential refractive index Solvent: tetrahydrofuran Concentration: 2% by mass Calibration curve: Created using standard polystyrene (PS) (manufactured by PL Co., Ltd.).

[0112] <Number of acid anhydride monomer units per molecular chain of copolymer> The number (N) of (unsaturated) acid anhydride monomer units per molecular chain of copolymer (B-1) was calculated using the following formula (1) based on the content of acid anhydride monomer units in copolymer (B-1) (A, unit: mass%), where the total amount of monomer units contained in copolymer (B-1) is taken as 100% by mass, and the number-average molecular weight (Mn) of copolymer (B-1). N=(A / 100)×Mn / 98 Formula (1)

[0113] <Glass transition temperature (Tg) of copolymers> The glass transition temperature of copolymer (B-1) was measured as the intermediate glass transition temperature (Tmg) by DSC in accordance with JIS K-7121, under the measurement conditions described below. Device name: Seiko Instruments Inc. Robot DSC6200 Heating rate: 10°C / min

[0114] <Amount of residual styrene monomer> The amount of residual styrene monomer in copolymer (B-1) was measured by the following procedure. As a pretreatment, 0.3-0.4 g of copolymer (B-1) was weighed into a 50 mL Erlenmeyer flask, 10 mL of DMF containing an internal standard (cyclopentanol) was added to dissolve the copolymer (B-1), and the following measurements were taken. Device name: GC-12A (manufactured by Shimadzu Corporation) Detector: FID Column: 3m glass column (packing material: liquid phase PEG20M + TCEP (15 + 5)) Temperature: INJ 150℃, DET 150℃, Column 115℃ Injection volume: 1μL

[0115] <Amount of remaining N-phenylmaleimide monomer> The amount of residual N-phenylmaleimide monomer in copolymer (B-1) was measured under the following conditions. Device name: GC-2010 (manufactured by Shimadzu Corporation) Column: Capillary column DB-5MS (phenylalene polymer) Temperature: Inlet 280°C, Detector 280°C The analysis was performed with a column temperature of 80°C (initial). (Temperature-based analysis conditions) 80℃: Hold for 12 minutes 80-280℃: Heat at a rate of 20℃ / min for 10 minutes 280℃: Hold for 10 minutes Detector: FID Procedure: 0.5 g of copolymer (B-1) was dissolved in 5 ml of 1,2-dichloroethane solution (0.014 g / L) containing undecane (internal standard). Then, 5 ml of n-hexane was added and the mixture was shaken for 10-15 minutes to precipitate. Only the supernatant liquid was injected into a GC after the polymer had precipitated. The quantitative value was calculated from the peak area of ​​the obtained monomer using a coefficient obtained from the internal standard.

[0116] • B-2: Styrene-maleic anhydride copolymer (EF40, CRAY VALLEY) [Composition: 82% by mass of styrene, 18% by mass of maleic anhydride; weight-average molecular weight: 10,000; number of acid anhydride monomer units per molecular chain of copolymer: 11; glass transition temperature: 120°C]

[0117] • B-3: 3 or 4-methyl-1,2,3,6-tetrahydrophthalic anhydride (HN-2200, Resonaq Corporation) [Molecular weight: 166; Number of acid anhydride monomer units per molecule: 1]

[0118] <Curing accelerator (C)> • C-1: 2-Ethyl-4-methylimidazole (2E4MZ, manufactured by Shikoku Chemicals Co., Ltd.) [Molecular weight: 110] • C-2: 1-Cyanoethyl-2-ethyl-4-methylimidazole (2MZ-CN, manufactured by Shikoku Chemicals Co., Ltd.) [Molecular weight 163]

[0119] <<Resin composition>> Compounds (A) A-1 to A-2, acid anhydride-based curing agents (B) B-1 to B-3, and curing accelerators (C) C-1 to C-2 were dissolved in the same amount of MEK as acid anhydride-based curing agent (B) in the formulations shown in Table 1 to obtain thermosetting resin compositions R-1 to R-9.

[0120] <<Manufacturing of hardened material>> [Example 1] The obtained thermosetting resin composition R-1 was vacuum-dried at 60°C for 240 minutes. Then, the stainless steel plate / mold (86mm x 86mm x 2mm mold) / 0.2mm thick fluororesin release film / vacuum-dried thermosetting resin composition R-1 / 0.2mm thick fluororesin release film / stainless steel plate were arranged in that order. As the first heating stage, the mold was preheated to 105°C and pressurized at 18 MPa for 120 minutes using a hot press molding machine. After that, the mold temperature was increased, and as the second heating stage, the mold temperature was 180°C and pressurized at 18 MPa for 240 minutes to produce a cured body. The weight of the vacuum-dried thermosetting resin composition R-1 used for molding was determined by calculating backward from the specific gravity of the cured body, so that the weight was 110 vol% of the mold. The specific gravity of the hardened material was measured at 23°C using an MDS-300 manufactured by Tokyo Glass Instruments Co., Ltd.

[0121] <Glass transition temperature (Tg) of the hardened material> The glass transition temperature of the cured material was measured as the intermediate glass transition temperature (Tmg) by DSC in accordance with JIS K-7121, under the measurement conditions described below. Device name: Seiko Instruments Inc. Robot DSC6200 Heating rate: 10°C / min

[0122] <Moldability> The moldability was evaluated based on the degree of gap formation between the mold and the cured body. The degree of gap formation was defined as the ratio of the area of ​​the cured body to the area of ​​the mold (%) [= (area of ​​cured body) / (area of ​​mold) × 100] when the cured body was observed from the thickness direction. The evaluation criteria for the ratio of the area of ​​the cured body to the area of ​​the mold are as follows. A: Over 99% B: 97% or higher and less than 99% C: 95% or more and less than 97% D: Less than 95%

[0123] [Example 2] The cured body was manufactured in the same manner as in Example 1, except that the mold temperature in the first stage was set to 87°C. [Example 3] The cured body was manufactured in the same manner as in Example 1, except that the mold temperature in the first stage was set to 123°C. [Example 4] A cured body was manufactured in the same manner as in Example 1, except that the second heating stage at 180°C was omitted. [Example 5] A cured body was manufactured in the same manner as in Example 1, except that the thermosetting resin composition R-2 was used and the mold temperature in the first stage was set to 98°C. [Example 6] A cured body was manufactured in the same manner as in Example 1, except that the thermosetting resin composition R-3 was used and the mold temperature in the first stage was set to 115°C. [Example 7] A cured product was manufactured in the same manner as in Example 1, except that thermosetting resin composition R-4 was used. [Example 8] A cured body was manufactured in the same manner as in Example 1, except that the thermosetting resin composition R-5 was used and the mold temperature in the first stage was set to 125°C. [Example 9] A cured body was manufactured in the same manner as in Example 1, except that the thermosetting resin composition R-6 was used and the mold temperature in the first stage was set to 139°C. [Example 10] A cured body was produced in the same manner as in Example 1, except that the thermosetting resin composition R-7 was used and the mold temperature in the first stage was set to 139°C. [Comparative Example 1] The cured body was manufactured in the same manner as in Example 1, except that the mold temperature in the first stage was set to 75°C. [Comparative Example 2] The cured body was manufactured in the same manner as in Example 1, except that the mold temperature in the first stage was set to 135°C. [Comparative Example 3] A cured body was manufactured in the same manner as in Example 1, except that the thermosetting resin composition R-7 was used and the mold temperature in the first stage was set to 87°C.

[0124] [Table 1]

[0125] [Table 2]

[0126] In Examples 1 to 10, the predetermined resin compositions exhibited good moldability and glass transition temperature when heated under conditions satisfying formula (1).

Claims

1. A method for manufacturing a cured body, It includes a first heating step, In the first heating step, the temperature T Ｈ１ Using the first heating section preheated to (°C), The resin composition in direct contact with the first heating element is heated, or The resin composition, which is placed in the first heating section via a solid heat transfer medium, is heated. The resin composition comprises a compound (A) having at least two epoxy groups in one molecule, an acid anhydride-based curing agent (B), and a curing accelerator (C). The curing accelerator (C) comprises one or more selected from the group consisting of imidazole-based curing accelerators, amine-based curing accelerators, ammonium salt-based curing accelerators, phosphine-based curing accelerators, phosphonium salt-based curing accelerators, urea-based curing accelerators, and fatty acid salt-based curing accelerators. Said T Ｈ１ The following equation (1) is satisfied, T １ -20≦T Ｈ１ ≦T １ +20 (1) The T in formula (1) １ (°C) is the temperature represented by the following formula (2): T １ (℃)=184×(Z / M×100) －０．０７ -40 (2) In formula (2) above, M (mol) is the amount of substance of the acid anhydride group in the resin composition, and Z (mol) is the amount of substance of the curing accelerator in the resin composition. Manufacturing method.

2. The manufacturing method according to claim 1, wherein the curing accelerator (C) includes the imidazole-based curing accelerator.

3. The method for producing the product according to claim 1, wherein the acid anhydride-based curing agent (B) comprises a copolymer (b1) having acid anhydride monomer units and aromatic vinyl monomer units.

4. The manufacturing method according to claim 3, wherein the copolymer (b1) comprises the acid anhydride monomer unit, the aromatic vinyl monomer unit, and the maleimide monomer unit.

5. The manufacturing method according to claim 4, wherein the copolymer (b1) has 5.0% by mass or more and less than 49.0% by mass of maleimide monomer units when the total amount of monomer units contained in the copolymer (b1) is 100% by mass.

6. The copolymer (b1) is defined as follows, when the total amount of monomer units contained in the copolymer (b1) is 100% by mass: The aforementioned aromatic vinyl monomer units amount to 45.0 to 89.9% by mass, The acid anhydride monomer units amount to 0.1 to 8.0% by mass, The maleimide monomer units amount to 10.0 to 30.0% by mass, Other monomer units are 0.0 to 20.0% by mass, The manufacturing method according to claim 5.

7. The reactive curing agent according to claim 4, wherein the number of acid anhydride monomer units contained per molecular chain of the copolymer (b1) is 2 to 25.

8. The reactive curing agent according to claim 4, wherein the glass transition temperature of the copolymer (b1) is 125 to 200°C.

9. The manufacturing method according to claim 4, wherein the weight-average molecular weight of the copolymer (b1) is 20,000 or more.

10. The above-mentioned T Ｈ１ satisfies the following formula (1A): T １ -15≦T Ｈ１ ≦T １ +15 (1A) The manufacturing method according to claim 1.

11. Said T Ｈ１ The following equation (1B) is satisfied: T １ -10≦T Ｈ１ ≦T １ +10 (1B) The manufacturing method according to claim 1.

12. In the first heating step, the first heating unit, which is in direct contact with the resin composition, heats the resin composition. The first heating section is a mold. The manufacturing method according to any one of claims 1 to 11.

13. In the first heating step, the first heating unit heats the resin composition via a solid heat transfer medium. The solid heat transfer medium is a metal foil. The manufacturing method according to any one of claims 1 to 11.

14. Further comprising a second heating step, In the second heating step described above, the temperature T Ｈ２ Using the second heating section which is (°C), The first hardened body in direct contact with the second heating section is heated, or The first hardened body, which is placed in the second heating section via a solid heat transfer medium, is heated. The first cured body is a cured body obtained by the first heating step, Said T Ｈ２ The following equations (3) and (4) are satisfied: T Ｈ１ <T Ｈ２ (3) 120℃≦T Ｈ２ ≦200℃ (4) The manufacturing method according to claim 1.

15. A method for manufacturing a molded article, Impregnation process, curing process, preparation, In the impregnation step, the reinforcing substrate is impregnated with a resin composition to form an impregnated substrate. The curing process comprises a first heating step, It includes a first heating step, In the first heating step, the temperature T Ｈ１ Using the first heating section preheated to (°C), The impregnated substrate in direct contact with the first heating unit is heated, or The first heating unit heats the impregnated substrate, which is arranged via a solid heat transfer medium. The resin composition comprises a compound (A) having at least two epoxy groups in one molecule, an acid anhydride-based curing agent (B), and a curing accelerator (C). The curing accelerator (C) comprises one or more selected from the group consisting of imidazole-based curing accelerators, amine-based curing accelerators, ammonium salt-based curing accelerators, phosphine-based curing accelerators, phosphonium salt-based curing accelerators, urea-based curing accelerators, and fatty acid salt-based curing accelerators. Said T Ｈ１ The following equation (1) is satisfied, T １ -20≦T Ｈ１ ≦T １ +20 (1) The T in formula (1) １ (°C) is the temperature represented by the following formula (2): T １ (℃)=184×(Z / M×100) －０．０７ -40 (2) In formula (2) above, M (mol) is the amount of substance of the acid anhydride group in the resin composition, and Z (mol) is the amount of substance of the curing accelerator in the resin composition. Manufacturing method.

16. The curing step further comprises a second heating step, In the second heating step, the temperature is T Ｈ２ Using the second heating section which is (°C), The second heating unit, which is in direct contact with the first molded body, heats the first molded body, or The first molded body, which is placed in the second heating section via a solid heat transfer medium, is heated. The first molded body is a molded body obtained by the first heating step, Said T Ｈ２ The following equations (3) and (4) are satisfied: T Ｈ１ <T Ｈ２ (3) 120℃≦T Ｈ２ ≦200℃ (4) The manufacturing method according to claim 15.

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