Sheet-shaped epoxy resin molding material, columnar sheet, and method for manufacturing columnar sheet

Abstract

The sheet-shaped epoxy resin molding material of the present application contains an epoxy resin and a fibrous or acicular filler, and has a cross-sectional area of 3 cm 2 The above 100 cm 2 Hereinafter, when the specific gravity of the sheet-shaped epoxy resin molding material is set as G, the mass as M (g), and the volume as V (cm 3 ) according to JIS K 6911:2006, the compression ratio calculated from [(M / G) / V] x 100 satisfies 70% or more and 95% or less.

Description

Technical Field

[0001] This invention relates to sheet-like epoxy resin molding materials, columnar sheets, and methods for manufacturing columnar sheets. Background Technology

[0002] To date, various methods for molding sheet-like epoxy resin molding materials have been developed. For example, the technology described in Patent Document 1 is known. Patent Document 1 describes a method for transfer molding a sheet-like epoxy resin composition containing inorganic fillers such as quartz glass powder, talc, silica powder, alumina powder, and calcium carbonate in order to seal semiconductor elements (claims 1, paragraphs 0005 and 0030 of Patent Document 1, etc.).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 9-208805 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] However, the inventors' research has shown that the sheet-like epoxy resin molding material described in Patent Document 1 has room for improvement in terms of resistance to breakage and fracture toughness during transportation.

[0008] Means for solving technical problems

[0009] Further research by the inventors revealed that by reducing the compression ratio of the sheet-like epoxy resin molding material to an appropriate value, it is possible to mold a molded body with excellent resistance to breakage and fracture toughness during transportation, thus completing the present invention.

[0010] According to one aspect of the present invention, it is possible to provide the following sheet-like epoxy resin molding material, columnar sheet, and method for manufacturing columnar sheet.

[0011] 1. A sheet-like epoxy resin molding material, characterized in that it contains:

[0012] Epoxy resin; and

[0013] Fiber or needle-like fillers,

[0014] Cross-sectional area is 3cm 2 Above 100cm 2 the following,

[0015] Let the specific gravity of the sheet-like epoxy resin molding material, measured according to JIS K 6911:2006, be G, the mass be M (g), and the volume be V (cm³).3 When [(M / G) / V]×100 is used, the compression rate is above 70% and below 95%.

[0016] 2. The sheet-like epoxy resin molding material according to 1, characterized in that:

[0017] The volume average fiber length of the fibrous or needle-like filler, measured according to step A below, is more than 5 μm and less than 500 μm.

[0018] (Step A)

[0019] After dissolving the sheet-like epoxy resin molding material in acetone to remove the resin components, the insoluble components were dispersed on a glass plate. The filler in the insoluble components was photographed using an optical microscope, and the fiber length was determined using an image analysis device. The average fiber length, based on fiber volume, of the first 100 fillers arranged from longest to shortest was taken as the volume average fiber length.

[0020] 3. The sheet-like epoxy resin molding material according to 1. or 2, characterized in that:

[0021] When the volume average fiber length of the fibrous or needle-like filler, measured according to step A below, is set as L, and the number average fiber diameter of the fibrous or needle-like filler, measured according to step B below, is set as D,

[0022] L / D is between 3 and 100.

[0023] (Step A)

[0024] After dissolving the sheet-like epoxy resin molding material in acetone to remove the resin components, the insoluble components were dispersed on a glass plate. The filler in the insoluble components was photographed using an optical microscope, and the fiber length was determined using an image analysis device. The average fiber length, based on fiber volume, of the first 100 fillers arranged from longest to shortest was taken as the volume average fiber length.

[0025] (Step B)

[0026] Using a scanning electron microscope, the cross-sections of 100 fibrous or needle-like fillers were measured from the cross-section of the sheet-like epoxy resin molding material, and the average of the minimum diameter of each fiber cross-section was obtained as the number-average fiber diameter.

[0027] 4. The sheet epoxy resin molding material according to any one of 1 to 3, characterized in that:

[0028] The fibrous or needle-like filler comprises one or more selected from wollastonite fibers, glass fibers, metal fibers, carbon fibers, fibrous alumina, aramid fibers, silicon carbide whiskers, silicon nitride whiskers, and potassium titanate whiskers.

[0029] 5. The sheet-like epoxy resin molding material according to any one of 1 to 4, characterized in that:

[0030] The spiral flow measured according to the following steps is greater than 20 cm.

[0031] (step)

[0032] Using a low-pressure transfer molding machine, the sheet-like epoxy resin molding material was injected into a mold for spiral flow measurement according to EMMI-1-66 under the conditions of mold temperature of 175°C, injection pressure of 6.9 MPa, and curing time of 120 seconds, and the flow length (cm) was measured.

[0033] 6. The sheet-like epoxy resin molding material according to any one of 1 to 5, characterized in that:

[0034] In the sheet-like epoxy resin molding material, the content of the fibrous or needle-like filler is more than 5% by mass and less than 80% by mass.

[0035] 7. The sheet epoxy resin molding material according to any one of 1 to 6, characterized in that:

[0036] The epoxy resin contains cresol varnish-type epoxy resin and / or bisphenol A type epoxy resin.

[0037] 8. The sheet-like epoxy resin molding material according to any one of 1 to 7, characterized in that:

[0038] It contains one or more curing catalysts selected from amine-based catalysts and phosphorus-based catalysts.

[0039] 9. The sheet-like epoxy resin molding material according to any one of 1 to 8, characterized in that:

[0040] It has 5cm 3 Above 1500cm 3 The following volumes.

[0041] 10. The sheet-like epoxy resin molding material according to any one of 1 to 9, characterized in that:

[0042] The sheet-like epoxy resin molding material can be used for any of the following: magnet fixing, electronic control unit sealing, coil sealing, or stator core sealing.

[0043] 11. A columnar sheet, characterized in that it is formed from any one of the sheet-like epoxy resin molding materials described in 1. to 10.

[0044] 12. A method for manufacturing a columnar sheet, characterized in that it comprises:

[0045] The process of obtaining epoxy resin molding materials by melt-blending an epoxy resin composition containing epoxy resin and fibrous or needle-like fillers; and

[0046] The process of obtaining columnar sheets using the obtained epoxy resin molding material.

[0047] The cross-sectional area of ​​the columnar sheet is 3 cm². 2 Above 100cm 2 the following,

[0048] Let the specific gravity of the columnar sheet, measured according to JIS K 6911:2006, be G, the mass be M (g), and the volume be V (cm³). 3 When [(M / G) / V]×100 is used, the compression rate is above 70% and below 95%.

[0049] Invention Effects

[0050] According to the present invention, sheet-shaped epoxy resin molding materials, columnar sheets, and methods for manufacturing columnar sheets are provided that can produce molded articles with excellent resistance to breakage and fracture toughness during transportation. Attached Figure Description

[0051] Figure 1 This is a cross-sectional view illustrating the general structure of the tensile compression testing machine. Detailed Implementation

[0052] The embodiments of the present invention will now be described using the accompanying drawings. Furthermore, in all the drawings, the same reference numerals are used to denote the same constituent elements, and descriptions are omitted where appropriate. Also, the drawings are schematic diagrams and do not correspond to actual dimensions.

[0053] An overview of the sheet-like epoxy resin molding material of this embodiment will be described.

[0054] The sheet-like epoxy resin molding material of this embodiment is composed of epoxy resin and fibrous or needle-like fillers.

[0055] Cross-sectional area is 3cm 2 Above 100cm 2 the following,

[0056] Let the specific gravity of the sheet-like epoxy resin molding material, measured according to JIS K 6911:2006, be G, the mass be M (g), and the volume be V (cm³).3 When [(M / G) / V]×100 is used, the compression rate is above 70% and below 95%.

[0057] According to the inventors' insights, it has been determined that by appropriately reducing the compression ratio of sheet epoxy resin molding materials, it is possible to mold articles with excellent fracture toughness.

[0058] Although the detailed mechanism is not yet clear, it can be inferred that the tablet's low compression ratio means that the tablet is formed under mild conditions. During the tablet forming process under mild conditions, the fiber length of the fibrous or needle-like filler can be suppressed, thus preventing the reduction of the fracture toughness of the molded body.

[0059] The upper limit of the aforementioned compression ratio is 95% or less, preferably 94% or less, and more preferably 93% or less. This allows for the molding of a molded article with excellent fracture toughness. Furthermore, it improves mechanical strength such as flexural modulus.

[0060] On the other hand, the lower limit of the aforementioned compression ratio is, for example, 70% or more, preferably 75% or more, and more preferably 80% or more. This helps to suppress the decrease in the breakage resistance of the molded article during transportation.

[0061] Transportation can include air transport, land transport, and sea transport.

[0062] In this embodiment, the compression ratio can be controlled, for example, by appropriately selecting the types and amounts of each component included in the epoxy resin molding material, and the preparation method of the epoxy resin molding material. Among these, for example, as manufacturing conditions, factors such as appropriately controlling the molding pressure and compression time during molding, and increasing the fiber length of the fiber filler, can be cited as elements for achieving the desired compression ratio within a certain range.

[0063] Such epoxy resin molding materials can be used for magnet fixing, electronic control unit (ECU) sealing, coil sealing, or stator core sealing. Specifically, sheet-shaped epoxy resin molding materials can be used for magnet fixing, electronic control unit (ECU) sealing, coil sealing, or stator core sealing using known molding methods.

[0064] In these various applications, it can improve the mechanical properties of the molded body, such as the flexural modulus of elasticity. Furthermore, in rotor cores with skewed structures, it can suppress the generation of gaps when filled with magnet fixing material.

[0065] The columnar sheet in this embodiment is a columnar molded body obtained by molding the above-mentioned epoxy resin molding material.

[0066] A method for manufacturing sheet-like epoxy resin molding materials, for example as an extrusion molding method, may include: a step of melt-blending an epoxy resin composition containing at least epoxy resin and fibrous or needle-like fillers to obtain an epoxy resin molding material; and a step of using the obtained epoxy resin molding material to obtain a sheet.

[0067] The method for obtaining the tablets can employ known methods, such as using a tableting machine to compress the powdered epoxy resin composition into tablets. Not limited to this molding method, a method can also be used to obtain tablets by continuously extruding molten epoxy resin molding material from an opening at the front end of an extruder while simultaneously cutting the epoxy resin molding material.

[0068] The granular epoxy resin composition contains powder and / or particles. For example, relatively fine particles (powder) can be obtained by pulverizing and / or classifying relatively coarse particles (particles).

[0069] The particle shape of the epoxy resin composition is not particularly limited and can be spherical, polygonal, or irregular in shape. These can be used alone or in combination of two or more.

[0070] The volume of the sheet-like epoxy resin molding material (sheet) is, for example, 5 cm³. 3 Above 1500cm 3 The following is preferred: 10cm 3 Above 1000cm 3 the following.

[0071] For example, the cross-sectional area of ​​the columnar sheet is 3 cm². 2 Above 100cm 2 The following is preferred: 10cm 2 Above 95cm 2 the following.

[0072] The length of the columnar sheet is, for example, 10 mm to 300 mm, preferably 20 mm to 200 mm.

[0073] By using sheet-like epoxy resin molding material and employing known molding methods such as transfer molding, it is possible to manufacture any one of the following fixed structures or sealing structures: magnet fixing structure, electronic control unit sealing structure, coil sealing structure, and stator core sealing structure.

[0074] Regarding the aforementioned fixed or sealed structures, for example, as a rotor core for fixing magnets, one can refer to international publication WO2012 / 029278, etc.; as an electronic control unit for vehicles, one can refer to international publication WO2016 / 139985, etc.; and as a stator core, one can refer to Japanese Patent Application Laid-Open No. 2020-094092, etc.

[0075] The use of epoxy resin molding material in the above-mentioned magnet fixing structure will be explained.

[0076] The rotor core includes: multiple holes; and permanent magnets inserted into the multiple holes respectively. The permanent magnets can be fixed to the rotor core by filling the space between the holes and the permanent magnets with epoxy resin molding material.

[0077] The use of epoxy resin molding materials in the sealing structure of automotive electronic control units is explained.

[0078] The vehicle-mounted electronic control unit includes a substrate on which electronic components are mounted. In the vehicle-mounted electronic control unit, at least a portion of the substrate and the electronic components can be sealed together using an epoxy resin molding material.

[0079] The use of epoxy resin molding materials in coil sealing structures is explained.

[0080] The coil, consisting of windings such as copper wire, is used in motors or transformers. For insulation, the coil is molded (sealed) with an epoxy resin molding material.

[0081] The use of epoxy resin molding materials in stator core sealing structures is explained.

[0082] The stator core includes: multiple teeth; and coils (windings) wound on the multiple teeth respectively.

[0083] By sealing the coil wound around the teeth with epoxy resin molding material, the coil can be insulated from the stator core. Alternatively, if the teeth formed on the stator core have a receiving portion, by receiving the coil wound around the teeth within the receiving portion and filling the space between them with epoxy resin molding material, the coil can be insulated from the stator core.

[0084] Alternatively, as an example of manufacturing, the following method can be used: An insulating layer is formed on the surface of the stator core using an epoxy resin molding material. Then, the coil is inserted into the teeth and sealed using the epoxy resin molding material.

[0085] The windings that can be used in the aforementioned coils or stator cores can be made of round wire or flat wire.

[0086] The process of manufacturing a fixed structure or a sealed structure can be carried out, for example, using sheet-like epoxy resin molding material, at a temperature of 120°C to 200°C and a pressure of 3 MPa to 15 MPa, preferably at a temperature of 140°C to 180°C and a pressure of 5 to 12 MPa.

[0087] The lower limit of the spiral flow of the epoxy resin molding material is, for example, 30 cm or more, preferably 50 cm or more.

[0088] On the other hand, the upper limit of the spiral flow of the epoxy resin molding material is, for example, 250 cm or less, preferably 200 cm or less.

[0089] Helical flow can be measured using the following steps.

[0090] Using a low-pressure transfer molding machine, epoxy resin molding material was injected into a mold for spiral flow determination according to EMMI-1-66 under the conditions of mold temperature of 175°C, injection pressure of 6.9 MPa, and curing time of 120 seconds, and the flow length (cm) was measured.

[0091] The method for manufacturing sheets using the epoxy resin molding material of this embodiment is not limited to compression molding; extrusion molding, transfer molding, injection molding, etc., can also be used.

[0092] The components of the epoxy resin molding material of this embodiment will now be described in detail.

[0093] [Epoxy Resin]

[0094] Epoxy resin molding materials contain epoxy resin.

[0095] Examples of epoxy resins include phenolic varnish resins such as phenolic varnish resins, cresol varnish resins, and bisphenol A varnish resins; methyl phenolic resins; phenolic varnish epoxy resins such as phenolic varnish epoxy resins and cresol varnish epoxy resins; bisphenol type epoxy resins such as bisphenol A type epoxy resin and bisphenol F type epoxy resin; aromatic glycidylamine type epoxy resins such as N,N-diglycidylaniline, N,N-diglycidyltoluidine, diaminodiphenylmethane type glycidylamine, and aminophenol type glycidylamine; hydroquinone type epoxy resins; and biphenyl type epoxy resins. Epoxy resins, including arsenic-type epoxy resins, triphenol methane-type epoxy resins, triphenol propane-type epoxy resins, alkyl-modified triphenol methane-type epoxy resins, triazine-core-containing epoxy resins, dicyclopentadiene-modified phenol-type epoxy resins, naphthol-type epoxy resins, naphthyl-type epoxy resins, phenol aralkyl-type epoxy resins with a phenylene backbone and / or a biphenylene backbone, naphthol aralkyl-type epoxy resins with a phenylene backbone and / or a biphenylene backbone, and other aralkyl-type epoxy resins, as well as alicyclic epoxy resins such as vinylcyclohexene dioxide, dicyclopentadiene oxide, and alicyclic diethio-adipate esters. These can be used alone or in combination of two or more.

[0096] The epoxy resin preferably contains cresol varnish-type epoxy resin and / or bisphenol A type epoxy resin.

[0097] The epoxy resin content is preferably 5% by mass or more and 40% by mass or less, more preferably 10% by mass or more and 20% by mass or less, relative to the overall epoxy resin molding material.

[0098] [Curing agent]

[0099] Epoxy resin molding materials may contain curing agents used to cure epoxy resin.

[0100] As a curing agent, phenolic resin-based curing agents are preferred, for example. Examples of phenolic resin-based curing agents include phenolic varnish resins such as phenol, cresol, and naphthol; multifunctional phenolic resins such as triphenol-methane phenolic resins; modified phenolic resins such as terpene-modified and dicyclopentadiene-modified phenolic resins; aralkyl resins such as phenol with a phenylene and / or biphenylene skeleton, and naphthol with a phenylene and / or biphenylene skeleton; and bisphenol compounds such as bisphenol A and bisphenol F. One of these can be used alone, or two or more can be used simultaneously. Using such phenolic resin-based curing agents results in a good balance of flame retardancy, moisture resistance, electrical properties, curing properties, and storage stability.

[0101] Furthermore, examples of curing agents that can be used simultaneously include addition-polymerization curing agents and condensation-polymerization curing agents.

[0102] Examples of addition-polymer curing agents include: polyamine compounds, such as aliphatic polyamines like diethylenetriamine (DETA), triethylenetetramine (TETA), and m-phenylenediamine (MXDA); aromatic polyamines like diaminodiphenylmethane (DDM), m-phenylenediamine (MPDA), and diaminodiphenyl sulfone (DDS); as well as dicyandiamide (DICY) and organic acid diacid hydrazides; acid anhydrides, such as alicyclic acid anhydrides like hexahydrophthalic anhydride (HHPA) and methyltetrahydrophthalic anhydride (MTHPA); aromatic acid anhydrides like trimellitic anhydride (TMA), pyromellitic tetracarboxylic anhydride (PMDA), and benzophenone tetracarboxylic dianhydride (BTDA); polyphenolic compounds such as phenolic resins and phenol polymers; polysulfides, thioesters, and thioethers; isocyanate compounds such as isocyanate prepolymers and capped isocyanates; and organic acids such as carboxylic acid-containing polyester resins.

[0103] Examples of condensation-type curing agents include methyl phenolic resins, urea resins such as hydroxymethyl urea resins, and melamine resins such as hydroxymethyl melamine resins.

[0104] Furthermore, the phenolic resin and epoxy resin used as curing agents are preferably combined in such a way that the equivalent ratio (EP) of the number of epoxy groups (EP) in the epoxy resin molding material to the number of phenolic hydroxyl groups (OH) in all phenolic resins is 0.8 to 1.3 or less. When the equivalent ratio is within the above range, sufficient curing properties can be obtained when the obtained epoxy resin molding material is molded. In the case where resins other than phenolic resins that can react with epoxy resins are used simultaneously, the equivalent ratio can be adjusted appropriately.

[0105] [Inorganic packing]

[0106] (Fibrous or needle-like fillers)

[0107] Epoxy resin molding materials contain fibrous or needle-like fillers as inorganic fillers.

[0108] The lower limit of the volume average fiber length of the fibrous or needle-like filler is, for example, 5 μm or more, preferably 10 μm or more, more preferably 30 μm or more, and even more preferably 50 μm or more. This improves the strength of the material.

[0109] On the other hand, the upper limit of the volume average fiber length of the fibrous or needle-like filler is, for example, 500 μm or less, preferably 450 μm or less, and more preferably 400 μm or less. This improves the formability of the material.

[0110] When the volume average fiber length of the fibrous or needle-like filler is set as L and the number average fiber diameter of the fibrous or needle-like filler is set as D, the aspect ratio is defined as L / D.

[0111] The lower limit of the L / D ratio of the fibrous or needle-like filler is, for example, 3 or more, preferably 10 or more, and more preferably 15 or more. This further improves the flexural modulus and, consequently, the toughness.

[0112] On the other hand, the upper limit of the L / D of the fibrous or needle-like filler is, for example, 100 or less, preferably 70 or less, and more preferably 50 or less. This improves the formability of the material.

[0113] (Step A for determining the volume average fiber length)

[0114] After dissolving the epoxy resin molding material in acetone to remove the resin components, the insoluble components were dispersed on a glass plate. The filler in the insoluble components was photographed using an optical microscope, and the fiber length was measured using an image analysis device. The average fiber length, based on fiber volume, of the first 100 fillers arranged from longest to shortest was taken as the volume average fiber length.

[0115] (Step B for determining the number-average fiber diameter)

[0116] Using a scanning electron microscope, the cross-sections of 100 fibrous or needle-like fillers were measured from the cross-section of the epoxy resin molding material, and the average of the minimum diameter of each fiber cross-section was calculated as the number-average fiber diameter.

[0117] The fibrous or needle-like filler may contain one or more selected from wollastonite fibers, glass fibers, metal fibers, carbon fibers, fibrous alumina, aramid fibers, silicon carbide whiskers, silicon nitride whiskers, and potassium titanate whiskers. Preferably, it contains at least one of wollastonite fibers and glass fibers, and more preferably, it contains wollastonite fibers.

[0118] In this epoxy resin composition, the lower limit of the content of fibrous or needle-like fillers in 100% by mass is, for example, 5% by mass or more, preferably 10% by mass or more, and more preferably 30% by mass or more. This further improves the flexural modulus and also enhances toughness.

[0119] On the other hand, the upper limit of the content of fibrous or needle-like fillers in 100% by mass of the epoxy resin composition is not particularly limited, and can be 80% by mass or less, preferably 75% by mass or less.

[0120] Furthermore, the lower limit of the content of fibrous or needle-like fillers in all inorganic fillers is, for example, 30% by mass or more, preferably 40% by mass or more, and more preferably 50% by mass or more. This further improves the flexural modulus of elasticity and enhances toughness.

[0121] On the other hand, there is no particular limit to the upper limit of the content of fibrous or needle-like fillers in all inorganic fillers, which can be less than 100% by mass.

[0122] (Inorganic fillers other than fibrous or needle-shaped fillers)

[0123] Epoxy resin molding materials may contain inorganic fillers other than fibrous or needle-like fillers.

[0124] Other inorganic packing materials are not particularly limited as long as they have a spherical, polygonal, or irregular shape. Specifically, inorganic packing materials with an aspect ratio of 2 or less are preferred, and spherical inorganic packing materials are more preferred.

[0125] Other inorganic fillers include, for example, silica, alumina, kaolin, talc, clay, mica, rock wool, glass powder, glass flakes, glass beads, silicon carbide, silicon nitride, aluminum nitride, carbon black, graphite, titanium dioxide, calcium carbonate, calcium sulfate, barium carbonate, magnesium carbonate, magnesium sulfate, and barium sulfate. These can be used individually or in combination of two or more.

[0126] Silica can be made from materials such as molten crushed silica and molten spherical silica, as well as crystalline silica.

[0127] The average particle size D of the inorganic filler 50 Preferably, the average particle size is 0.01 μm to 75 μm, more preferably 0.05 μm to 50 μm. By keeping the average particle size of the inorganic filler within the above range, the filling performance within the mold is improved. Furthermore, by setting the upper limit of the average particle size of the inorganic filler to 75 μm or less, the filling performance is further improved. Average particle size D 50 The volume-converted average particle size is obtained using a RODOS SR type laser diffraction measuring device (SYMPATEC HEROS & RODOS).

[0128] The content of inorganic filler relative to the epoxy resin molding material as a whole is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 65% ​​by mass or more, and especially preferably 75% by mass or more.

[0129] On the other hand, relative to the overall epoxy resin molding material, the content of inorganic filler is preferably 93% by mass or less, more preferably 91% by mass or less, and even more preferably 90% by mass or less.

[0130] Furthermore, when using inorganic fillers and inorganic flame retardants such as aluminum hydroxide, magnesium hydroxide, zinc borate, zinc molybdate, and antimony trioxide simultaneously, the total amount of these inorganic flame retardants and the aforementioned inorganic fillers is preferably within the range of the aforementioned inorganic filler content.

[0131] [Cure catalyst]

[0132] Epoxy resin molding materials may contain curing catalysts as needed.

[0133] As a curing catalyst, it is preferred to use one or more of the following: amine-based catalysts and phosphorus-based catalysts.

[0134] As amine catalysts, imidazoles are preferred, for example. Imidazoles may include, for example, imidazole compounds selected from imidazole, 2-methylimidazole, 2-undecylimidazole, 2-heptadecaylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 2-phenyl-4,5-dihydroxyimidazole, 2-phenyl-4,5-dihydroxydimethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole, etc., 1-cyano... The following are one or more of the following: ethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl(1')]-ethyl-triazine, 2,4-diamino-6-[2'-undecylimidazolyl(1')]-ethyl-triazine, 2,4-diamino-6-[2'-ethyl-4-methylimidazolyl(1')]-ethyl-triazine, isocyanuric acid adducts of 2,4-diamino-6-[2'-methylimidazolyl(1')]-ethyl-triazine, isocyanuric acid adducts of 2-phenylimidazolium, isocyanuric acid adducts of 2-methylimidazolium, and hexamethylenetetramine.

[0135] When the curing catalyst includes an amine catalyst, the lower limit of the content of the amine catalyst relative to the overall epoxy resin molding material is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, and particularly preferably 0.05% by mass or more.

[0136] Furthermore, relative to the overall epoxy resin molding material, the upper limit of the content of the amine catalyst is preferably 2.0% by mass or less, more preferably 1.5% by mass or less, and especially preferably 1.0% by mass or less.

[0137] Examples of phosphorus-based catalysts include organophosphorus compounds, tetrasubstituted phosphonium compounds, phosphate betaine compounds, adducts of phosphonium compounds and quinone compounds, and adducts of phosphonium compounds and silane compounds, as well as other phosphorus-containing compounds.

[0138] Examples of organophosphines that can be used in epoxy resin molding materials include primary phosphines such as ethylphosphine and phenylphosphine; secondary phosphines such as dimethylphosphine and diphenylphosphine; and tertiary phosphines such as trimethylphosphine, triethylphosphine, tributylphosphine, and triphenylphosphine.

[0139] Examples of tetrasubstituted phosphonium compounds that can be used in epoxy resin molding materials include compounds represented by the following general formula (4).

[0140]

[0141] (In the above general formula (4), P represents a phosphorus atom. R) 4 R 5 R 6 and R 7 This indicates an aromatic group or alkyl group. A represents the anion of an aromatic organic acid having at least one functional group selected from hydroxyl, carboxyl, or thiol groups on the aromatic ring. AH represents an aromatic organic acid having at least one functional group selected from hydroxyl, carboxyl, or thiol groups on the aromatic ring. x and y are numbers from 1 to 3, z is a number from 0 to 3, and x = y.

[0142] The compound represented by general formula (4) can be obtained, for example, as follows, but is not limited thereto. First, a tetrasubstituted phosphonium halide, an aromatic organic acid, and a base are mixed in an organic solvent and homogenized, so that an aromatic organic acid anion is generated in the solution system. Then, when water is added, the compound represented by general formula (4) can be precipitated. In the compound represented by general formula (4), R bonded to a phosphorus atom is preferred. 4 R 5 R 6 and R 7 A compound is a phenyl group, and AH is a hydroxyl group on an aromatic ring; that is, a phenol, and A is the anion of the phenol. Examples of such phenols include monocyclic phenols such as phenol, cresol, resorcinol, and catechol; condensed polycyclic phenols such as naphthol, dihydroxynaphthalene, and anthraquinone phenol; bisphenols such as bisphenol A, bisphenol F, and bisphenol S; and polycyclic phenols such as phenylphenol and biphenol.

[0143] Phosphate betaine compounds that can be used as curing catalysts include, for example, compounds represented by the following general formula (5).

[0144]

[0145] (In the above general formula (5), R) 8 R represents an alkyl group having 1 to 3 carbon atoms. 9 This represents a hydroxyl group. f is a number from 0 to 5, and g is a number from 0 to 3.

[0146] The compound represented by general formula (5) is obtained, for example, by the following steps: First, a triaromatic substituted phosphine, which is a tertiary phosphine, is contacted with a diazonium salt, thereby causing the triaromatic substituted phosphine to replace the diazonium group present in the diazonium salt. However, this is not a limitation.

[0147] Examples of compounds that can be used as curing catalysts and are adducts of phosphine and quinone compounds include compounds represented by the following general formula (6).

[0148]

[0149] (In the above general formula (6), P represents a phosphorus atom. R) 10 R 11 and R 12 R represents an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms; they can be the same or different from each other. 13 R 14 and R 15 R represents a hydrocarbon group consisting of 1 to 12 hydrogen or carbon atoms, which can be the same or different from each other. 14 With R 15 They can bond together to form a ring structure.

[0150] The phosphine compound used as an adduct of a phosphine compound and a quinone compound is preferably a phosphine compound that is unsubstituted on the aromatic ring or has substituents such as alkyl or alkoxy groups, such as triphenylphosphine, tri(alkylphenyl)phosphine, tri(alkoxyphenyl)phosphine, trinaphthylphosphine, or tri(benzyl)phosphine. Examples of substituents such as alkyl or alkoxy groups include those having 1 to 6 carbon atoms. From the viewpoint of availability, triphenylphosphine is preferred.

[0151] In addition, quinone compounds used as adducts of phosphine compounds and quinone compounds include benzoquinone and anthraquinones, among which p-benzoquinone is preferred from the viewpoint of preservation stability.

[0152] As a method for producing adducts of phosphine and quinone compounds, the adduct can be obtained by contacting and mixing an organophosphine and a benzoquinone in a solvent capable of dissolving both. Preferably, the solvent is a ketone such as acetone or methyl ethyl ketone, which has low solubility for the adduct. However, it is not limited to this.

[0153] In the compounds represented by general formula (6), from the viewpoint of reducing the thermal elastic modulus of the cured epoxy resin molding material, R bonded to phosphorus atoms is preferred. 10 R 11 and R 12 It is a phenyl group and R 13 R 14 and R 15 Compounds containing hydrogen atoms, including those obtained by the addition reaction of 1,4-benzoquinone with triphenylphosphine.

[0154] Examples of compounds that can be used as curing catalysts and are adducts of phosphonium compounds and silane compounds include compounds represented by the following general formula (7).

[0155]

[0156] (In the above general formula (7), P represents a phosphorus atom and Si represents a silicon atom. R 16 R 17 R 18 and R 19 These represent organic groups with aromatic or heterocyclic rings, or aliphatic groups, which may be the same or different from each other. In the formula, R... 20 For the group Y 2 and Y 3 Bonded organic groups. Where R 21 For the group Y 4 and Y 5 Bonded organic groups. Y 2 and Y 3 A group representing a proton-donating group that releases a proton; a group Y within the same molecule. 2 and Y 3 It bonds with silicon atoms to form a chelate structure. 4 and Y 5 A group representing a proton-donating group that releases a proton; a group Y within the same molecule. 4 and Y 5 It bonds with silicon atoms to form a chelate structure. 20 and R 21 They can be the same or different, Y 2 Y 3 Y 4 and Y 5 They can be the same or different. Z 1 These are organic groups with aromatic or heterocyclic rings, or aliphatic groups.

[0157] In general formula (7), as R 16 R 17 R 18 and R 19 Examples of such groups include phenyl, methylphenyl, methoxyphenyl, hydroxyphenyl, naphthyl, hydroxynaphthyl, benzyl, methyl, ethyl, n-butyl, n-octyl, and cyclohexyl. Among these, aromatic groups with alkyl, alkoxy, hydroxynaphthyl, or other substituents, or unsubstituted aromatic groups, are more preferred.

[0158] Furthermore, in general formula (7), R 20 To be with Y 2 and Y 3 Bonded organic groups. Similarly, R 21 For the group Y 4 and Y 5 Bonded organic groups. Y 2 and Y 3A group formed by releasing a proton from a proton-donating group; a group Y within the same molecule. 2 and Y 3 It bonds with silicon atoms to form a chelate structure. Similarly, Y 4 and Y 5 A group formed by releasing a proton from a proton-donating group; a group Y within the same molecule. 4 and Y 5 It bonds with silicon atoms to form a chelate structure. Group R 20 and R 21 They can be the same or different, group Y 2 Y 3 Y 4 and Y 5 They can be the same or different. In such a general formula (7), -Y 2 -R 20 -Y 3 -and-Y 4 -R 21 -Y 5 - The group represented is a group formed by the release of two protons from a proton donor. As a proton donor, it is preferably an organic acid having at least two carboxyl or hydroxyl groups in the molecule, more preferably an aromatic compound having at least two carboxyl or hydroxyl groups on adjacent carbon atoms constituting the aromatic ring, and even more preferably an aromatic compound having at least two hydroxyl groups on adjacent carbon atoms constituting the aromatic ring. Examples include catechol, pyrogallol, 1,2-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,2'-biphenyl, 1,1'-bi-2-naphthol, salicylic acid, 1-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, chloroquinone acid, tannic acid, 2-hydroxybenzyl alcohol, 1,2-cyclohexanediol, 1,2-propanediol, and glycerol. Among these, catechol, 1,2-dihydroxynaphthalene, and 2,3-dihydroxynaphthalene are more preferred.

[0159] Furthermore, Z in general formula (7) 1 The term refers to organic groups or aliphatic groups having aromatic or heterocyclic rings. Specific examples of these groups include aliphatic hydrocarbon groups such as methyl, ethyl, propyl, butyl, hexyl, and octyl; aromatic hydrocarbon groups such as phenyl, benzyl, naphthyl, and biphenyl; and reactive substituents such as glycidoxypropyl, mercaptopropyl, and aminopropyl alkyl and vinyl groups having glycidoxy, mercapto, or amino groups. Among these, methyl, ethyl, phenyl, naphthyl, and biphenyl are preferred from the viewpoint of thermal stability.

[0160] A method for producing an adduct of a phosphonium compound and a silane compound involves adding and dissolving a silane compound such as phenyltrimethoxysilane and a proton donor such as 2,3-dihydroxynaphthalene in a flask containing methanol. Then, a sodium methoxide-methanol solution is added dropwise while stirring at room temperature. Next, a pre-prepared solution containing a tetrasubstituted phosphonium halide such as tetraphenylphosphonium bromide dissolved in methanol is added dropwise while stirring at room temperature, causing crystals to precipitate. The precipitated crystals are then filtered, washed with water, and dried under vacuum to obtain the adduct of the phosphonium compound and the silane compound. However, this method is not limited to this procedure.

[0161] The content of the curing catalyst, relative to the total epoxy resin molding material, is preferably 0.05% by mass or more, more preferably 0.08% by mass or more, and particularly preferably 0.10% by mass or more. By setting the content of the curing catalyst to the lower limit or above, the curability of the epoxy resin molding material during transfer molding can be effectively improved. On the other hand, the content of the curing catalyst, relative to the total epoxy resin molding material, is preferably 2.0% by mass or less, more preferably 1.0% by mass or less, and particularly preferably 0.5% by mass or less. By setting the content of the curing catalyst to the upper limit or below, the flowability during sealing can be improved, which helps to improve the filling performance.

[0162] [wax]

[0163] Epoxy resin molding materials may contain wax as a release agent, depending on the requirements.

[0164] Examples of waxes include natural waxes such as carnauba wax, ester waxes, lignite ester waxes, synthetic waxes such as oxidized polyethylene wax, and higher fatty acids and their metal salts such as zinc stearate.

[0165] The amount of wax incorporated relative to the total epoxy resin molding material is, for example, 0.05% by mass or more and 2.0% by mass or less. The lower limit of the wax amount incorporated relative to the total epoxy resin molding material is preferably 0.1% by mass or more, more preferably 0.2% by mass or more. The upper limit of the wax amount incorporated relative to the total epoxy resin molding material is preferably 1.5% by mass or less, more preferably 1.0% by mass or less. By incorporating wax within the above ranges, the resulting epoxy resin molding material exhibits excellent flowability and filling properties during transfer molding.

[0166] [Coupled agent]

[0167] Epoxy resin molding materials may contain coupling agents such as silane coupling agents as needed.

[0168] Examples of coupling agents include epoxy silanes, amino silanes, ureosilanes, and mercaptosilanes.

[0169] Examples of epoxy silanes include γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. Examples of amino silanes include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropylmethyldimethoxysilane, N-phenylγ-aminopropyltriethoxysilane, N-phenylγ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropyltriethoxysilane, N-6-(aminohexyl)3-aminopropyltrimethoxysilane, and N-(3-(trimethoxysilylpropyl)-1,3-phenyldimethylamine). Furthermore, examples of ureosilanes include γ-ureopropyltriethoxysilane and hexamethyldisilazane. Potential aminosilane coupling agents obtained by protecting the primary amino group of an aminosilane through reaction with a ketone or aldehyde can also be used. Furthermore, aminosilanes may have a secondary amino group. Furthermore, examples of mercaptosilanes include γ-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and silane coupling agents such as bis(3-triethoxysilylpropyl)tetrasulfide and bis(3-triethoxysilylpropyl)disulfide, which exhibit the same function as mercaptosilane coupling agents through thermal decomposition. Substances obtained by pre-hydrolyzing these silane coupling agents can also be used. One of these silane coupling agents can be used alone, or two or more can be used simultaneously.

[0170] From the viewpoint of continuous molding, mercaptosilanes are preferred; from the viewpoint of flowability, aminosilanes are preferred; and from the viewpoint of adhesion, epoxysilanes are preferred.

[0171] The lower limit for the content of coupling agents such as silane coupling agents that can be used in epoxy resin molding materials is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and particularly preferably 0.1% by mass or more, relative to the total epoxy resin molding material. When the lower limit for the content of coupling agents such as silane coupling agents is within the above range, the interfacial strength between the epoxy resin and the inorganic filler will not decrease, and good vibration resistance can be obtained. Furthermore, the upper limit for the content of coupling agents such as silane coupling agents is preferably 1% by mass or less, more preferably 0.8% by mass or less, and particularly preferably 0.6% by mass or less, relative to the total epoxy resin molding material. When the upper limit for the content of coupling agents such as silane coupling agents is within the above range, the interfacial strength between the epoxy resin and the inorganic filler will not decrease, and good vibration resistance can be obtained. Furthermore, when the content of coupling agents such as silane coupling agents is within the above range, the increase in water absorption of the cured epoxy resin molding material can be prevented.

[0172] [Other Additives]

[0173] In addition to the components described above, the epoxy resin molding material of this embodiment may also contain other additives such as colorants, flame retardants, stress reducers, and bonding agents, as needed. These can be used individually or in combination of two or more.

[0174] The embodiments of the present invention have been described above, but these are merely examples, and various configurations other than those described may also be employed. Furthermore, the present invention is not limited to the embodiments described above, and modifications and improvements within the scope of achieving the objectives of the present invention are also included in the present invention.

[0175] Example

[0176] The present invention will now be described in detail with reference to embodiments, but the present invention is not limited to any of the embodiments described herein.

[0177] (Examples 1-3, Comparative Examples 1 and 2)

[0178] <Manufacturing of Sheet Epoxy Resin Molding Materials>

[0179] The mixture of materials prepared according to the proportions shown in Table 1 below is kneaded with a heated roller, cooled into sheet form, and then pulverized to obtain a granular epoxy resin composition.

[0180] In addition, the mixing conditions for the heating roller are: rotation speed 20 rpm, temperature 120℃, and mixing time 5 to 10 minutes.

[0181] The details of each component in Table 1 regarding the raw materials of the epoxy resin composition are as follows.

[0182] • Fibrous or needle-like filler: Glass fiber (manufactured by Nitto Boseki Co., Ltd., CS3E479)

[0183] Other inorganic fillers: Crushed silica (manufactured by Tatsumori Ltd., RD-8)

[0184] • Colorant: Carbon black

[0185] • Epoxy resin: Phenolic varnish type epoxy resin (manufactured by DIC Corporation, N680)

[0186] • Hardener: Phenolic resin varnish 1 (manufactured by Sumitomo Bakelite Co., Ltd., PR51470)

[0187] • Hardener: Phenolic resin varnish 2 (manufactured by Sumitomo Bakelite Co., Ltd., PR51714)

[0188] • Curing catalyst: Amine-based catalyst (manufactured by Shikoku Chemicals Corporation, 2PZ-PW)

[0189] Wax: Carnauba wax

[0190] Wax: Calcium stearate

[0191] • Low-stress agent: Organic modified silicone oil (manufactured by Dow Inc., FZ-3730)

[0192] • Sealing aid: Triazine compound (manufactured by Shikoku Chemical Corporation, VD-5)

[0193] The epoxy resin composition obtained above was compressed into tablets using a tablet press (manufactured by Kikusui Seisakusho Ltd., BARPRESS) under the molding pressure and compression time conditions shown in Table 2, to obtain tablets with a weight of 8g, a tablet diameter of 14mm, and a tablet height of 29mm.

[0194] Through the above process, sheet-like epoxy resin molding materials (sheets) with different compression ratios of Examples 1-3 and Comparative Examples 1 and 2 were produced.

[0195] <Compression Ratio>

[0196] The specific gravity (G), mass (M) and volume (V) of the obtained sheet-like epoxy resin molding material were determined according to JIS K 6911:2006. 3 Using the measured G, M, and V, the compression ratio (%) was calculated using the formula: [(M / G) / V]×100. The results are shown in Table 2.

[0197] <Volume Average Fiber Length>

[0198] After dissolving the epoxy resin molding material in acetone to remove the resin components, the insoluble components were dispersed on a glass plate. The filler in the insoluble components was photographed using an optical microscope, and the fiber length was determined using an image analysis device. The average fiber length (μm) of the first 100 fillers arranged from longest to shortest, defined by the following formula based on fiber volume, was taken as the volume average fiber length. The results are shown in Table 2.

[0199] Lv = Σ(L×v) / Σv

[0200] Σ represents the set, L represents the length of each fiber, and v represents the volume of each fiber.

[0201] [Table 1]

[0202]

[0203] The following aspects were evaluated for the obtained epoxy resin compositions and sheet epoxy resin molding materials.

[0204] [Table 2]

[0205]

[0206] <Spiral Flow>

[0207] Using a low-pressure transfer molding machine (manufactured by KOHTAKI Corporation, KTS-15), the obtained epoxy resin composition was injected into a spiral flow measurement mold according to EMMI-1-66 under the conditions of mold temperature of 175°C, injection pressure of 6.9 MPa, and holding time of 120 seconds, and the flow length was measured.

[0208] <Bending Test: Flexural Modulus>

[0209] The obtained sheet was injection molded using a transfer molding machine at a mold temperature of 175℃, an injection pressure of 9.8MPa, and a curing time of 120 seconds to obtain a cured material with a width of 10mm × thickness of 4mm × length of 80mm as a test sheet.

[0210] The flexural modulus (GPa) of the test piece at room temperature was determined according to JIS K 6911.

[0211] <K1c>

[0212] Following the KIc method standardized in ASTM D5045-14, the obtained sheet-like epoxy resin molding material (cylindrical sheet) was adjusted to a size of 50 mm in length, 5 mm in width (B), and 10 mm in thickness (W). A notch with a depth of 3.5 mm in the thickness direction was formed in the center of the length direction. The material was cured at 175°C for 4 hours to obtain a cured product. Then, a 0.1 mm deep scratch was made on the front end of the notch in the thickness direction using a razor to create a test piece with a total crack length a = 3.6 mm.

[0213] Then, as Figure 1As shown in the summary, a tensile compression testing machine (STB-1225S Tensilon manufactured by ORIENTEC Co., Ltd.) was used to perform a three-point bending test on the obtained test piece 10 under the conditions of a test temperature of 25°C, a speed of 10 mm / min, and a support distance S = 40 mm. The fracture toughness value (K1c (MPa·m)) was calculated according to the following formula. 1 / 2 In the following formula, P Q This represents the maximum load (N). Additionally... Figure 1 The tensile and compression testing machine has a load pin 12 with a diameter of 10 mm and two R-machined circular support points 14.

[0214] KI C =(P Q ×S) / (B×W) 3 / 2 ))×f(a / W)

[0215] Among them, f(a / W)=(3(a / W) 1 / 2 [1.99-(a / W)(1-a / W){2.15-3.9(a / W)+2.7(a / W) 2}]) / (2{1+2(a / W)}{1-(a / W)} 3 / 2 )

[0216] When the fracture toughness value of Comparative Example 1 calculated above is standardized to 1.0, the relative values ​​of fracture toughness values ​​of Examples 1 to 3 and Comparative Examples 1 and 2 are shown in Table 2.

[0217] <Evaluation of resistance to breakage during transport>

[0218] The resistance to damage during transport is evaluated in the following manner.

[0219] The obtained sheets were stored in a box, and a transportation test with specified vibration was conducted for a specified time under this condition. The height of the sheets before and after the transportation test was measured with vernier calipers. If the standard deviation of the sheet height after transportation was within 20% of the average height of the sheet before transportation (just after forming), it was judged that there was little damage during transportation and good resistance to breakage during transportation. If the standard deviation exceeded 20%, it was judged that the resistance to breakage during transportation was poor.

[0220] Based on the above results, it can be seen that the epoxy resin molding materials of Examples 1-3 exhibit better resistance to breakage during transportation compared to Comparative Example 1. Furthermore, it can be seen that the epoxy resin molding materials of Examples 1-3 have higher fracture toughness and higher mechanical strength compared to Comparative Example 2.

[0221] The epoxy resin molding materials of Examples 1 to 3 are suitable for use in magnet fixing, electronic control unit sealing, coil sealing, or stator core sealing.

[0222] This application claims priority based on Japanese Patent Application No. 2024-058574, filed on April 1, 2024, the entire contents of which are incorporated herein by reference.

[0223] Explanation of reference numerals in the attached figures

[0224] 10 test pieces, 12 load pins, 14 circular fulcrums.

Claims

1. A sheet-like epoxy resin molding material, characterized in that, contain: Epoxy resin; and Fiber or needle-like fillers, Cross-sectional area is 3cm 2 Above 100cm 2 the following, Let the specific gravity of the sheet-like epoxy resin molding material, measured according to JIS K 6911:2006, be G, the mass be M (g), and the volume be V (cm³). 3 When [(M / G) / V]×100 is used, the compression rate is above 70% and below 95%.

2. The sheet-like epoxy resin molding material according to claim 1, characterized in that: The volume average fiber length of the fibrous or needle-like filler, measured according to step A below, is between 5 μm and 500 μm. Step A: After dissolving the sheet-like epoxy resin molding material in acetone to remove the resin components, the insoluble components are dispersed on a glass plate. The filler in the insoluble components is photographed using an optical microscope, and the fiber length is determined using an image analysis device. The average fiber length of the first 100 fillers arranged from longest to shortest, based on the fiber volume, is taken as the volume average fiber length.

3. The sheet-like epoxy resin molding material according to claim 1 or 2, characterized in that: When the volume average fiber length of the fibrous or needle-like filler, measured according to step A below, is set as L, and the number average fiber diameter of the fibrous or needle-like filler, measured according to step B below, is set as D, L / D is between 3 and 100 Step A: After dissolving the sheet-like epoxy resin molding material in acetone to remove the resin components, the insoluble components were dispersed on a glass plate. The filler in the insoluble components was photographed using an optical microscope, and the fiber length was measured using an image analysis device. The average fiber length, based on fiber volume, of the first 100 fillers arranged from longest to shortest was taken as the volume average fiber length. Step B: Using a scanning electron microscope, the cross-sections of 100 fibrous or needle-like fillers were measured from the cross-section of the sheet-like epoxy resin molding material, and the average of the minimum diameter of each fiber cross-section was obtained as the number-average fiber diameter.

4. The sheet-like epoxy resin molding material according to claim 1 or 2, characterized in that: The fibrous or needle-like filler comprises one or more selected from wollastonite fibers, glass fibers, metal fibers, carbon fibers, fibrous alumina, aramid fibers, silicon carbide whiskers, silicon nitride whiskers, and potassium titanate whiskers.

5. The sheet-like epoxy resin molding material according to claim 1 or 2, characterized in that: The spiral flow measured according to the following steps is greater than 20 cm. step: Using a low-pressure transfer molding machine, the sheet-like epoxy resin molding material was injected into a mold for spiral flow measurement according to EMMI-1-66 under the conditions of mold temperature of 175°C, injection pressure of 6.9 MPa, and curing time of 120 seconds, and the flow length (cm) was measured.

6. The sheet-like epoxy resin molding material according to claim 1 or 2, characterized in that: In the sheet-like epoxy resin molding material, the content of the fibrous or needle-like filler is more than 5% by mass and less than 80% by mass.

7. The sheet-like epoxy resin molding material according to claim 1 or 2, characterized in that: The epoxy resin contains cresol varnish-type epoxy resin and / or bisphenol A type epoxy resin.

8. The sheet-like epoxy resin molding material according to claim 1 or 2, characterized in that: It contains one or more curing catalysts selected from amine-based catalysts and phosphorus-based catalysts.

9. The sheet-like epoxy resin molding material according to claim 1 or 2, characterized in that: It has 5cm 3 Above 1500cm 3 The following volumes.

10. The sheet-like epoxy resin molding material according to claim 1 or 2, characterized in that: The sheet-like epoxy resin molding material can be used for any of the following: magnet fixing, electronic control unit sealing, coil sealing, or stator core sealing.

11. A columnar sheet, characterized in that: It is formed from the sheet-like epoxy resin molding material as described in claim 1 or 2.

12. A method for manufacturing a columnar sheet, characterized in that, include: The process of obtaining epoxy resin molding materials by melt-blending an epoxy resin composition containing epoxy resin and fibrous or needle-like fillers. and The process of obtaining columnar sheets using the obtained epoxy resin molding material. The cross-sectional area of ​​the columnar sheet is 3 cm². 2 Above 100cm 2 the following, Let the specific gravity of the columnar sheet, measured according to JIS K 6911:2006, be G, the mass be M (g), and the volume be V (cm³). 3 When [(M / G) / V]×100 is used, the compression rate is above 70% and below 95%.

Images