Epoxy resin composition particles, briquette, and method for producing columnar briquette

Abstract

The epoxy resin composition particles of the present invention are used in any one of magnet fixing, electronic control unit sealing, coil sealing, or stator core sealing, and are characterized by containing an epoxy resin and a fibrous or needle-like filler.

Description

TECHNICAL FIELD

[0001] The present application relates to a manufacturing method of an epoxy resin composition particle, a tablet, and a cylindrical tablet. BACKGROUND

[0002] Hitherto, various developments have been made on a molding method of a tablet-shaped epoxy resin composition. As such a technique, for example, the technique described in Patent Literature 1 is known. In Patent Literature 1, a method of performing transfer molding on a tablet-shaped epoxy resin composition obtained by compounding quartz glass powder, talc, silica powder, alumina powder, calcium carbonate, or the like as an inorganic filler is described (claim 1, paragraphs 0005, 0030, and the like of Patent Literature 1).

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Laid-Open No. 9-208805 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] However, as a result of the present inventors' studies, it was found that there is room for improvement in the bending elastic modulus of the tablet-shaped epoxy resin composition described in the above Patent Literature 1.

[0008] Further, in a molded body having a skew structure obtained using the conventional epoxy resin composition, a phenomenon in which a gap is generated at a discontinuous surface of the molded body (a portion of the molded body where the displacement occurs) was confirmed.

[0009] MEANS FOR SOLVING THE PROBLEMS

[0010] As a result of further studies by the present inventors, it was found that the use of an epoxy resin composition particle containing an epoxy resin and a fibrous or acicular filler makes it possible to improve the mechanical properties such as the bending elastic modulus of a molded body, and thus a molding material suitable for any one of a magnet fixing, an electronic control unit sealing, a coil sealing, or a stator core sealing can be achieved, and thus the first application was completed.

[0011] Further, the present inventors focused on a molded body having a skew structure obtained using the conventional epoxy resin composition. It is considered that, in the case where a magnet fixing material is filled in a rotor core having a skew structure, a corner portion of a magnet that becomes a portion that hinders the flow of the magnet fixing material is a starting point of a damage in the magnet fixing material, and thus a gap is generated.

[0012] As a result of further research by the present inventors, it was found that by using the fracture toughness value of the material for fixing a magnet as an index, the degree of gap when filled in a skew structure can be stably evaluated. As a result of further research based on this insight, it was found that by using a moderately high kneading temperature on the basis of using a fibrous or acicular filler, the fracture toughness value in the epoxy resin composition particles can be increased to a prescribed value or more, whereby the generation of a gap when filled in a skew structure can be suppressed, thus completing the second invention.

[0013] According to the present invention, it is possible to provide the following epoxy resin composition particles and technologies related thereto.

[0014] [1] An epoxy resin composition particle for any one of magnet fixing, electronic control unit sealing, coil sealing, or stator core sealing,

[0015] The epoxy resin composition particle is characterized by containing:

[0016] an epoxy resin; and

[0017] a fibrous or acicular filler.

[0018] [2] An epoxy resin composition particle for magnet fixing,

[0019] The epoxy resin composition particle is characterized by containing:

[0020] an epoxy resin; and

[0021] a fibrous or acicular filler,

[0022] a fracture toughness value (K1c) of 3.0 MPa·m 1 / 2 or more, measured in the following Step i.

[0023] (Step i)

[0024] A molded body was molded from the epoxy resin composition particle using a transfer molding device based on molding conditions of a mold temperature of 175°C, an injection pressure of 9.8 MPa, and a curing time of 120 seconds.

[0025] The obtained molded body was made into a size of a length of 50 mm, a width B of 5 mm, and a thickness W of 10 mm, a notch of a depth of 3.5 mm in the thickness direction was formed in the central portion in the length direction, and a cured product was obtained by curing at 175°C for 4 hours. Further, a scratch of a depth of 0.1 mm in the thickness direction was applied to the front end portion of the notch of the cured product with a razor, and a test piece having a total crack length a = 3.6 mm was produced.

[0026] Then, for the obtained test pieces, a three-point bending test was performed using a tensile compression testing machine under the conditions of a measurement temperature of 25℃, a speed of 10mm / min, and a support distance S=40mm. The fracture toughness value (K1c (MPa·m)) was calculated according to the following formula. 1 / 2 In the following formula, P Q The maximum load is (N).

[0027] KI C =(P Q ×S) / (B×W) 3 / 2 ))×f(a / W)

[0028] 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 )

[0029] [3] The epoxy resin composition particles according to [1] or [2] are characterized in that:

[0030] The number-average fiber length of the fibrous or needle-like filler, measured according to step A below, is 5 μm to 500 μm.

[0031] (Step A)

[0032] After dissolving the epoxy resin composition particles 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. Starting with the filler with the longest fiber length, the average fiber length of 100 fillers was taken as the number-average fiber length.

[0033] [4] The epoxy resin composition particles according to any one of [1] to [3], characterized in that:

[0034] When the number-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,

[0035] L / D is between 3 and 100.

[0036] (Step A)

[0037] After dissolving the epoxy resin composition particles 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. Measurements were taken sequentially starting with the filler with the longest fiber length, and the average value of 100 fillers was taken as the number-average fiber length.

[0038] (Step B)

[0039] Using a scanning electron microscope, the cross-sections of 100 fibrous fillers were measured from the cross-sections of the epoxy resin composition particles, and the average of the minimum diameters of each fiber cross-section was determined as the number-average fiber diameter.

[0040] [5] The epoxy resin composition particles according to any one of [1] to [4], characterized in that:

[0041] The fibrous or needle-like filler contains 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.

[0042] [6] The epoxy resin composition particles according to any one of [1] to [5], characterized in that:

[0043] The spiral flow measured in step ii below is 30 cm or more.

[0044] (Step ii)

[0045] Using a low-pressure transfer molding machine, the epoxy resin composition particles were injected into a spiral flow measurement mold according to EMMI-1-66 under the conditions of mold temperature 175°C, injection pressure 6.9 MPa, and curing time 120 seconds, and the flow length (cm) was measured.

[0046] [7] The epoxy resin composition particles according to any one of [1] to [6], characterized in that:

[0047] In the epoxy resin composition particles, the content of the fibrous or needle-like filler is more than 5% by mass and less than 80% by mass in 100% by mass.

[0048] [8] The epoxy resin composition particles according to any one of [1] to [7], characterized in that:

[0049] The epoxy resin contains cresol varnish-type epoxy resin and / or bisphenol A type epoxy resin.

[0050] [9] The epoxy resin composition particles according to any one of [1] to [8], characterized in that:

[0051] The epoxy resin composition particles contain one or more curing catalysts selected from imidazole-based catalysts and phosphorus-based catalysts.

[0052]

[10] The epoxy resin composition particles according to any one of [1] to [9], characterized in that:

[0053] The epoxy resin composition particles are used to form briquettes through the following steps: feeding the epoxy resin composition particles to a heated extruder and mixing them while they melt to obtain an epoxy resin molding material; and continuously extruding the molten epoxy resin molding material from an opening at the front end of the extruder and cutting the epoxy resin molding material to obtain briquettes.

[0054]

[11] The epoxy resin composition particles according to any one of [1] to

[10] , characterized in that:

[0055] For injection molding, in which an injection molding apparatus is used, the injection molding apparatus comprising an injection unit consisting of a barrel and a screw inserted into the barrel, and a mold having a cavity connected to the injection unit, wherein the epoxy resin composition particles are fed into the barrel for use.

[0056]

[12] The epoxy resin composition particles according to any one of [1] to

[11] , characterized in that:

[0057] Contains epoxy resin or curing agent with a softening point of less than 110℃.

[0058]

[13] A pressing block, characterized in that:

[0059] The compressed block is formed using any one of the epoxy resin composition particles described in [1] to

[12] ,

[0060] The pressing block has a diameter of 5cm. 3 Above 1500cm 3 The following volumes.

[0061]

[14] A method for manufacturing a columnar pressure block, characterized in that it includes:

[0062] The process of preparing epoxy resin composition particles as described in any one of [1] to

[12] ;

[0063] The process of feeding the epoxy resin composition particles into a heated extruder and mixing them while melting them to obtain an epoxy resin molding material; and

[0064] The process of continuously extruding molten epoxy resin molding material from the opening at the front end of an extruder and cutting the epoxy resin molding material to obtain columnar briquettes.

[0065] The cross-sectional area of ​​the columnar pressure block is 3 cm². 2 Above 100cm 2 the following.

[0066]

[15] A structure, characterized in that:

[0067] The structure is formed using any one of the epoxy resin composition particles described in [1] to

[12] .

[0068]

[16] A method for manufacturing a structure, which is the method for manufacturing the structure described in

[15] .

[0069] In the manufacturing method of the structure, an injection molding apparatus is used, which includes an injection unit consisting of a barrel and a screw inserted into the barrel, and a mold with a cavity connected to the injection unit.

[0070] The method for manufacturing the structure is characterized by comprising:

[0071] The process of melting the epoxy resin composition particles in the barrel to form a molten resin composition; and

[0072] The process of injecting molten resin composition from the front end of the screw to fill the mold cavity.

[0073]

[17] The method for manufacturing the structure according to

[16] is characterized in that:

[0074] During the filling process, the temperature T at the front end of the screw is 60–100°C.

[0075]

[18] The method for manufacturing the structure according to

[16] or

[17] is characterized in that:

[0076] During the filling process, the temperature inside the mold cavity is 150–180°C.

[0077] Invention Effects

[0078] According to the present invention, epoxy resin composition particles that can be molded into molded articles with excellent flexural modulus, or epoxy resin composition particles that have excellent gap suppression when filled in oblique structures, can be provided. Attached Figure Description

[0079] Figure 1 This is a longitudinal cross-sectional view of an extruder in one example of this embodiment.

[0080] Figure 2 This is a cross-sectional schematic diagram showing an example of the injection molding apparatus according to this embodiment.

[0081] Figure 3 This is a cross-sectional view illustrating the general structure of the tensile compression testing machine. Detailed Implementation

[0082] Hereinafter, embodiments of the present invention will be described using the accompanying drawings. Furthermore, in all the drawings, the same reference numerals are used to label the same constituent elements, and descriptions are omitted where appropriate. Also, the drawings are schematic diagrams and do not correspond to actual dimensions.

[0083] <First Embodiment>

[0084] The epoxy resin composition particles of this embodiment are particulate epoxy resin compositions containing epoxy resin and fibrous or needle-like fillers.

[0085] Such epoxy resin composition particles can be used for magnet fixing, electronic control unit (ECU) sealing, coil sealing, or stator core sealing. Specifically, a briquette-shaped molding material can be manufactured from the epoxy resin composition particles, and the obtained briquette-shaped molding material can be used for magnet fixing, electronic control unit (ECU) sealing, coil sealing, or stator core sealing by known molding methods.

[0086] By utilizing the epoxy resin composition particles of this embodiment, the mechanical properties of the obtained molded article, such as the flexural modulus of elasticity, can be improved. That is, by the entanglement of fibrous or needle-like fillers, the toughness of the molded article can be easily improved, thus making it easier to obtain elasticity that is more suitable for magnet fixing, electronic control unit (ECU) sealing, coil sealing, or stator core sealing.

[0087] <Second Implementation>

[0088] The epoxy resin composition particles of this embodiment contain epoxy resin and fibrous or needle-like fillers, and the fracture toughness value (K1c) measured according to step i below satisfies 3.0 MPa·m. 1 / 2 above.

[0089] By setting the fracture toughness value (K1c) of the epoxy resin composition particles to or above the aforementioned lower limit, gap formation can be suppressed in rotor cores with skewed structures when magnet fixing materials filled with epoxy resin composition particles are used. The exact reason is not yet clear, but it can be considered that the degree of crack propagation can be highly controlled by the fracture toughness value. Therefore, it can be considered that even if cracks occur in rotor cores with skewed structures filled with epoxy resin composition particles, crack propagation can be appropriately controlled using this fracture toughness value, thus suppressing gap formation.

[0090] The upper limit of the fracture toughness value (K1c) mentioned above is not particularly limited; for example, it can be 10.0 MPa·m. 1 / 2 the following.

[0091] (Step i for measuring fracture toughness)

[0092] Using a transfer molding apparatus, a molded body is formed from the epoxy resin composition particles under molding conditions of 175°C mold temperature, 9.8 MPa injection pressure, and 120 seconds curing time.

[0093] Following the KIc method specified in ASTM D5045-14, the obtained molded body was made into a size of 50 mm in length, B5 mm in width, and W10 mm in thickness. A notch with a depth of 3.5 mm in the thickness direction was formed in the center of the length direction. It was cured at 175°C for 4 hours to obtain a cured product. Then, a scratch with a depth of 0.1 mm in the thickness direction was applied to the front end of the notch of the cured product with a razor to produce a test piece with a total crack length a = 3.6 mm.

[0094] Then, for the obtained test pieces, a three-point bending test was performed using a tensile compression testing machine under the conditions of a measurement temperature of 25℃, a speed of 10mm / min, and a support distance S=40mm. The fracture toughness value (K1c (MPa·m)) was calculated according to the following formula. 1 / 2 In the following formula, P Q The maximum load is (N).

[0095] KI C =(P Q ×S) / (B×W) 3 / 2 ))×f(a / W)

[0096] 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 )}

[0097] In this embodiment, the fracture toughness value can be controlled, for example, by appropriately selecting the types and amounts of each component contained in the epoxy resin composition particles and the preparation method of the epoxy resin composition particles. Among the factors for ensuring that the fracture toughness value is within the desired range, examples include improving the material's compatibility and increasing the fiber length of the fiber filler.

[0098] The common structure and function of the epoxy resin composition particles in the first and second embodiments will be described below.

[0099] [Morphology of epoxy resin composition particles]

[0100] The epoxy resin composition particles of this embodiment are preferably used in the manufacture of tablet-shaped, more preferably columnar tablet-shaped, epoxy resin molding materials. Using the epoxy resin composition particles, tablet-shaped epoxy resin molding materials can be stably manufactured.

[0101] Regarding methods for manufacturing briquette-shaped epoxy resin molding materials, for example, as an extrusion molding method, it may include: a step of feeding epoxy resin composition particles to a heated extruder and mixing them while they are melting to obtain epoxy resin molding materials; and a step of continuously extruding the molten epoxy resin molding materials from the opening at the front end of the extruder and cutting the epoxy resin molding materials to obtain briquettes.

[0102] In the method for manufacturing the above-mentioned compressed epoxy resin molding material, as a specific example, it is possible to use... Figure 1 The extruder shown. Figure 1 A longitudinal cross-sectional view showing an example of the structure of an extruder.

[0103] The extruder includes: a hopper 2 into which epoxy resin composition particles 1 can be fed; a heater 41 for heating the epoxy resin composition particles 1 via a barrel 43; a screw 42; and a die 5 mounted at the front end of the extruder, having an opening of the same shape as a predetermined briquette cross-section and being temperature-controlled. Additionally, a temperature regulator 51 for controlling the temperature of the die 5 may be connected to the extruder.

[0104] The extruder extrudes epoxy resin composition particles 1 into barrel 43 and the feed-side barrel 43a, and simultaneously extrudes epoxy resin molding material formed by melting the epoxy resin composition particles 1 through heating, while the screw 42 performs compounding. Then, the extruder continuously extrudes the molten and compounded epoxy resin molding material from the opening of the die 5. The extruded epoxy resin molding material becomes extruded material 6. The extruded material 6 is cut into a predetermined briquette length using a cutting machine (not shown) or the like to obtain briquette-shaped epoxy resin molding material (briquette).

[0105] The epoxy resin composition particles 1 comprise powder and / or granules. For example, finer particles (powder) can be obtained by pulverizing and / or classifying relatively coarse particles (granules).

[0106] The shape of the epoxy resin composition particles 1 is not particularly limited; they can be spherical, polygonal, irregular in shape, etc. These can be used alone or in combination of two or more.

[0107] In this embodiment, the opening shape of the die 5 installed at the front end of the extruder is the same as the cross-sectional shape of the compressed epoxy resin molding material (briquette). Furthermore, when the opening shape is circular, the size of the opening shape is, for example, a diameter of 20 mm to 200 mm, preferably 40 mm to 120 mm. The opening shape, including its size, can be appropriately selected according to the desired briquette shape.

[0108] Furthermore, the extruded material 6 from the extruder can be cut into the desired length using a cutting machine. This length is, for example, 10 mm to 300 mm, preferably 20 mm to 200 mm.

[0109] The volume of the compressed block (compressed epoxy resin molding material) is, for example, 5 cm³. 3 Above 1500cm 3 The following is preferred: 10cm 3 Above 1000cm 3 the following.

[0110] The cross-sectional area of ​​the columnar compact is, for example, 3 cm². 2 Above 100cm 2 The following is preferred: 10cm 2 Above 95cm 2 the following.

[0111] By using the epoxy resin composition particles of this embodiment, it is possible to continuously obtain briquette-shaped epoxy resin molding materials, thus enabling the efficient manufacture of briquette-shaped epoxy resin molding materials with high briquette height.

[0112] Furthermore, the method of manufacturing briquettes using the epoxy resin composition particles of this embodiment is not limited to the extrusion molding method described above, and compression molding, transfer molding, injection molding, etc., can also be used.

[0113] [Physical properties of epoxy resin composition particles]

[0114] The lower limit of the spiral flow of the epoxy resin composition particles is, for example, 30 cm or more, preferably 50 cm or more.

[0115] On the other hand, the upper limit of the spiral flow of the epoxy resin composition particles is, for example, 250 cm or less, preferably 200 cm or less.

[0116] The spiral flow can be measured according to the following steps ii.

[0117] (Step ii)

[0118] Using a low-pressure transfer molding machine, epoxy resin composition particles were injected into a spiral flow measurement mold according to EMMI-1-66 under the conditions of mold temperature 175°C, injection pressure 6.9 MPa, and curing time 120 seconds, and the flow length (cm) was measured.

[0119] [Purpose / Usage]

[0120] Various structures can be manufactured by using compressed epoxy resin molding materials and employing known molding methods such as transfer molding and injection molding.

[0121] In this embodiment, the epoxy resin composition particles are preferably used for injection molding. Specifically, they are preferably used in injection molding in which an injection molding apparatus is used, the apparatus comprising an injection unit consisting of a barrel and a screw inserted into the barrel, and a mold having a cavity connected to the injection unit, wherein the epoxy resin composition particles are fed into the barrel for use.

[0122] For example, when using the epoxy resin composition particles of this embodiment to manufacture a magnet fixing structure, the epoxy resin composition particles can be fed into an injection molding machine and melted in the barrel, and the molten resin can be directly filled between the hole in the mold and the permanent magnet.

[0123] [Structure]

[0124] The structure of this embodiment is formed using the epoxy resin composition particles described above. Specifically, examples include any one of the following: a magnet fixing structure, an electronic control unit sealing structure, a coil sealing structure, and a stator core sealing structure.

[0125] Regarding the aforementioned fixed or sealed structures, for example, as a rotor core serving as a fixed magnet, reference can be made to International Publication No. 2012 / 029278, etc.; as an electronic control unit for vehicle use, reference can be made to International Publication No. 2016 / 139985, etc.; and as a stator core, reference can be made to Japanese Patent Application Publication No. 2020-094092, etc.

[0126] The use of epoxy resin molding material in the above-mentioned magnet fixing structure will be explained.

[0127] The rotor core includes multiple holes and permanent magnets inserted into each hole. The permanent magnets are secured to the rotor core by filling the space between the holes and the permanent magnets with epoxy resin molding material.

[0128] This section explains the use of epoxy resin molding materials in the sealing structure of vehicle electronic control units.

[0129] 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.

[0130] The use of epoxy resin molding materials in coil sealing structures is explained.

[0131] 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.

[0132] The use of epoxy resin molding materials in stator core sealing structures is explained.

[0133] The stator core consists of multiple teeth and coils (windings) wound on each of the multiple teeth respectively.

[0134] By sealing the coil wound on the teeth with an epoxy resin molding material, the coil can be insulated from the stator core. Furthermore, when the teeth formed on the stator core have a receiving portion, by receiving the coil wound on the teeth in the receiving portion and filling the space between them with epoxy resin molding material, the coil can be insulated from the stator core.

[0135] Furthermore, 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, a coil is inserted into the teeth to seal the coil using the epoxy resin molding material.

[0136] The windings that can be used in the above-mentioned coils or stator cores can be made of round wire or flat wire.

[0137] The process of manufacturing a fixed structure or a sealed structure can be carried out, for example, using a block-shaped 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.

[0138] [Manufacturing methods for structures]

[0139] The following is a detailed explanation of an example of a method for manufacturing a structure. The following uses... Figure 2 Please provide an explanation.

[0140] exist Figure 2 The image shows an injection molding apparatus 1, which includes: an injection unit 20 consisting of a barrel 21 and a screw 22 inserted into the barrel 21; and a mold 10 having a mold cavity 12.

[0141] The injection molding apparatus 1 includes: a mold 10 having a molding space (mold cavity 12) with a gate, runner, and sprue; and an injection molding machine 20 for performing injection molding. The injection molding machine 20 includes, for example: a barrel 21; a screw 22 capable of rotating within the barrel 21; a hopper 23 capable of feeding epoxy resin composition particles into the barrel 21; a heater 24 for melting and heating the epoxy resin composition particles via the barrel 21; and a nozzle 25 for discharging the epoxy resin composition particles, which have been melt-mixed within the barrel 21, to the mold 10.

[0142] Furthermore, in Figure 2 The diagram shows a screw 22 with a backflow valve 26 at its front end, but the screw 22 is not limited to this. The screw 22 may also not have a backflow valve 26.

[0143] The method for manufacturing the structure includes: a step of melting epoxy resin composition particles in a barrel 21 to form a molten resin composition; and a step of injecting the molten resin composition from the front end of a screw 22 to fill the mold cavity 12.

[0144] That is, firstly, epoxy resin composition particles are fed into the heating injection molding machine 20. Thereby, the epoxy resin composition particles are melted by the heater 24 inside the barrel 21 while being mixed by the screw 22. From the viewpoint of effectively heating the molten epoxy resin composition particles, the temperature at the tip of the screw 22 inside the barrel 21 is preferably 60–100°C.

[0145] Next, the molten resin composition is conveyed by the screw 22 while being compressed and mixed towards the nozzle 25, and the screw 22 descends rearward (in the opposite direction to the nozzle 25). At this time, a back pressure can be applied from the rear to push the screw 22, applying pressure to the molten resin composition gathered in the nozzle 25. Then, the molten resin composition gathered in the nozzle 25 at the front end of the screw 22 is metered to a set position.

[0146] Then, by advancing the screw 22, which is descending backward, the metered molten resin composition is injected into the mold cavity 12 of the mold 10 via the nozzle 25 using the pressure generated by the screw 22. From the viewpoint of properly filling the molten resin composition, the temperature inside the mold cavity 12 when filling the molten resin composition is preferably 150 to 180°C.

[0147] Next, the molten resin composition is cured in the mold cavity 12, and then the mold 10 is opened and the structure is removed from the mold cavity 12.

[0148] For example, when using the epoxy resin composition particles of this embodiment to manufacture a magnet fixing structure, the epoxy resin composition particles can be fed into an injection molding machine and melted in the barrel 21, and the molten resin can be directly filled between the hole in the mold 10 and the permanent magnet.

[0149] The components of the epoxy resin composition particles of this embodiment will be described in detail below.

[0150] [Epoxy Resin]

[0151] The epoxy resin composition particles contain epoxy resin.

[0152] 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 so on. Epoxy resins include benzene-type epoxy resins, styrene-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, naphthol-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 vinylcyclohexene dioxide, dicyclopentadiene dioxide, alicyclic diethio-adipate esters, and other alicyclic epoxy resins, etc. These can be used alone or in combination of two or more.

[0153] The epoxy resin preferably includes cresol varnish-type epoxy resin and / or bisphenol A type epoxy resin.

[0154] Furthermore, as an epoxy resin, a softening point of less than 80°C is preferred.

[0155] In addition, the softening point can be measured using the ball ring method.

[0156] 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 total epoxy resin composition particles.

[0157] [Curing agent]

[0158] The epoxy resin composition particles may contain a curing agent that cures the epoxy resin.

[0159] 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 backbone and / or a biphenylene backbone, and naphthol with a phenylene backbone and / or a biphenylene backbone; 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. With such phenolic resin-based curing agents, a good balance is achieved in terms of flame retardancy, moisture resistance, electrical properties, curing properties, and storage stability.

[0160] Furthermore, examples of curing agents that can be used simultaneously include addition curing agents and condensation curing agents.

[0161] Examples of addition polymerization 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 phenolic polymers; polysulfides, thioesters, and thioethers; isocyanate compounds such as isocyanate prepolymers and capped isocyanates; and organic acids such as carboxylic acid-containing polyester resins.

[0162] 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.

[0163] Furthermore, as a curing agent, the softening point is preferably less than 110°C, and more preferably less than 105°C.

[0164] In addition, the softening point can be measured using the ball ring method.

[0165] Furthermore, the phenolic resin and epoxy resin used as curing agents are preferably formulated such that the equivalent ratio (EP) of the number of epoxy groups (EP) in the epoxy resin composition particles 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 molding the obtained epoxy resin composition particles. However, when using resins other than phenolic resins that can react with epoxy resins, the equivalent ratio can be adjusted appropriately.

[0166] [Inorganic packing]

[0167] (Fiber-like or needle-like fillers)

[0168] The epoxy resin composition particles contain fibrous or needle-like fillers as inorganic fillers.

[0169] The lower limit of the number-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.

[0170] On the other hand, the upper limit of the number-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.

[0171] When the number-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.

[0172] 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.

[0173] 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.

[0174] (Step A for measuring number-average fiber length)

[0175] After dissolving the epoxy resin composition particles 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. Starting with the filler with the longest fiber length, the average fiber length of 100 fillers was taken as the above-mentioned number-average fiber length.

[0176] (Step B for measuring the number-average fiber diameter)

[0177] Using a scanning electron microscope, the cross-sections of 100 fibrous fillers were measured from the cross-sections of the epoxy resin composition particles, and the average of the minimum diameters of each fiber cross-section was determined as the number-average fiber diameter.

[0178] 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.

[0179] In this epoxy resin composition, the lower limit of the content of fibrous or needle-like fillers in 100% by mass of particles 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.

[0180] 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 particles is not particularly limited, and can be 80% by mass or less, preferably 75% by mass or less.

[0181] 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, more preferably 50% by mass or more, and even more preferably 72% by mass or more. This further improves the flexural modulus of elasticity and enhances toughness.

[0182] 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.

[0183] (Inorganic fillers other than fibrous or needle-shaped fillers)

[0184] The epoxy resin composition particles may contain inorganic fillers other than fibrous or needle-shaped fillers.

[0185] 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.

[0186] Other inorganic fillers include, for example, silica, alumina, kaolin, talc, clay, mica, asbestos, 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.

[0187] Silica can be made from materials such as molten crushed silica and molten spherical silica, as well as crystalline silica.

[0188] 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 To convert the volumetric average particle size measured using the RODOS SR type (SYMPATEC HEROS & RODOS) laser diffraction measuring device.

[0189] The content of inorganic filler relative to the total epoxy resin composition particles is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 65% ​​by mass or more, and particularly preferably 75% by mass or more.

[0190] On the other hand, relative to the total number of epoxy resin composition particles, 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.

[0191] Furthermore, when inorganic fillers and metal hydroxides such as aluminum hydroxide and magnesium hydroxide, or inorganic flame retardants such as zinc borate, zinc molybdate, and antimony trioxide, are used simultaneously, the total amount of these inorganic flame retardants and the aforementioned inorganic fillers is preferably within the range of the content of the aforementioned inorganic fillers.

[0192] [Cure catalyst]

[0193] The epoxy resin composition particles may contain a curing catalyst as needed.

[0194] As a curing catalyst, it is preferred to use one or more of imidazole-based and phosphorus-based catalysts.

[0195] As imidazole-based catalysts, imidazoles are preferred, for example. Imidazoles may include, for example, imidazole compounds selected from imidazole, 2-methylimidazolium, 2-undecylimidazolium, 2-heptadecylimidazolium, 1,2-dimethylimidazolium, 2-ethyl-4-methylimidazolium, 2-phenylimidazolium, 2-phenyl-4-methylimidazolium, 1-benzyl-2-phenylimidazolium, 1-benzyl-2-methylimidazolium, 1-cyanoethyl-2-methylimidazolium, 1-cyanoethyl-2-ethyl-4-methylimidazolium, 1-cyanoethyl-2-undecylimidazolium, 1-cyanoethyl-2-phenylimidazolium, 2-phenyl-4,5-dihydroxyimidazolium, 2-phenyl-4,5-dihydroxydimethylimidazolium, and 2-phenyl-4-methyl-5-hydroxymethylimidazolium. One or more of the following: 1-cyanoethyl-2-undecylimidazolium triester, 1-cyanoethyl-2-phenylimidazolium triester, 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, 2,4-diamino-6-[2'-methylimidazolyl(1')]-ethyl-triazine, isocyanuric acid adducts of 2-phenylimidazolium, and isocyanuric acid adducts of 2-methylimidazolium.

[0196] When the curing catalyst contains an imidazole-based catalyst, the lower limit of the imidazole-based catalyst content relative to the total epoxy resin composition particles 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.

[0197] Furthermore, the upper limit of the content of the imidazole catalyst relative to the total epoxy resin composition particles 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.

[0198] 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.

[0199] Examples of organophosphines that can be used in epoxy resin composition particles 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.

[0200] Examples of tetrasubstituted phosphonium compounds that can be used in epoxy resin composition particles include compounds represented by the following general formula (4).

[0201]

[0202] (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.

[0203] Compounds represented by general formula (4) can be obtained, for example, but are not limited to, the following method: First, a tetrasubstituted phosphonium halide, an aromatic organic acid, and a base are mixed and homogenized in an organic solvent to generate an aromatic organic acid anion in the solution system. Then, when water is added, the compound represented by general formula (4) can be precipitated. Among the compounds represented by general formula (4), R atoms bonded to phosphorus atoms are preferred. 4 R 5 R 6 and R 7 The phenol is a phenyl compound, and AH is a compound having a hydroxyl group on the aromatic ring, i.e., a phenol, where 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; bisphenols such as bisphenol A, bisphenol F, and bisphenol S; and polycyclic phenols such as phenylphenol and biphenol.

[0204] Phosphate betaine compounds that can be used as curing catalysts include, for example, compounds represented by the following general formula (5).

[0205]

[0206] (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.

[0207] Compounds represented by general formula (5). For example, obtained in the following manner. Obtained by the following steps: First, a triaromatic substituted phosphine, which is a tertiary phosphine, is contacted with a diazonium salt, thereby replacing the diazonium group present in the diazonium salt with the triaromatic substituted phosphine. However, it is not limited to this.

[0208] 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).

[0209]

[0210] (In the above general formula (6), P represents a phosphorus atom. R) 10 R 11 and R 12 The R group represents an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms; these groups may be the same as or different from each other. 13 R 14 and R 15 R represents hydrocarbon groups with 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.

[0211] Phosphine compounds used in adducts of phosphine and quinone compounds are preferably triphenylphosphine, tri(alkylphenyl)phosphine, tri(alkoxyphenyl)phosphine, trinaphthylphosphine, tri(benzyl)phosphine, etc., which are unsubstituted or have alkyl, alkoxy, or other substituents on the aromatic ring. Examples of alkyl, alkoxy, or other substituents include groups having 1 to 6 carbon atoms. From the viewpoint of availability, triphenylphosphine is preferred.

[0212] Furthermore, examples of quinone compounds used in adducts of phosphine compounds and quinone compounds include benzoquinone and anthraquinones, among which p-benzoquinone is preferred from the viewpoint of preservation stability.

[0213] 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.

[0214] In compounds represented by general formula (6), R bonded to phosphorus atoms 10 R 11 and R 12 It is phenyl and R 13 R 14 and R 15 Compounds containing hydrogen atoms, i.e., compounds obtained by adding 1,4-benzoquinone to triphenylphosphine, are preferred in terms of reducing the thermal modulus of the cured epoxy resin composition particles.

[0215] 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).

[0216]

[0217] (In the above general formula (7), P represents a phosphorus atom and Si represents a silicon atom. R16 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 This refers to a group formed by the release of a proton from a proton-donating group, and the group Y within the same molecule. 2 and Y 3 It bonds with silicon atoms to form a chelate structure. 4 and Y 5 This refers to a group formed by the release of a proton from a proton-donating group, and the 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 as each other, or they can be different from each other, Y 2 Y 3 Y 4 and Y 5 They can be the same as each other, or they can be different from each other. Z 1 These are organic groups with aromatic or heterocyclic rings, or aliphatic groups.

[0218] 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, more preferably are aromatic groups or unsubstituted aromatic groups having alkyl, alkoxy, hydroxy, or other substituents, such as phenyl, methylphenyl, methoxyphenyl, hydroxyphenyl, and hydroxynaphthyl.

[0219] 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 3 A group formed by releasing a proton from a proton-donating group, and 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, and 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 as each other or different from each other, group Y 2 Y 3 Y 4 and Y 5 They can be the same as each other, or they can be different from each other. In such a general formula (7), Y... 2 -R 20 -Y 3 -and-Y 4 -R 21 -Y 5 The group indicated by - is formed by the release of two protons from a proton donor. The proton donor is preferably an organic acid having at least two carboxyl or hydroxyl groups in the molecule, and more preferably an aromatic compound having at least two carboxyl or hydroxyl groups on adjacent carbons constituting the aromatic ring. More preferably, it is an aromatic compound having at least two hydroxyl groups on adjacent carbons constituting the aromatic ring. Examples include catechol, pyrogallol, 1,2-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,2'-biphenyl, 1,1'-bis-2-naphthol, salicylic acid, 1-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, chlorogenic 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.

[0220] Furthermore, Z in general formula (7) 1 This refers to an organic group or aliphatic group having an aromatic ring or heterocycle. Specific examples of these 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, aminopropyl, alkyl and vinyl groups having glycidoxy, mercapto, or amino groups. Among these, methyl, ethyl, phenyl, naphthyl and biphenyl are more preferred from the viewpoint of thermal stability.

[0221] 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 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.

[0222] The content of the curing catalyst relative to the total epoxy resin composition particles 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 value or above, the curability of the epoxy resin composition particles during transfer molding can be effectively improved. On the other hand, the content of the curing catalyst relative to the total epoxy resin composition particles 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 value or below, the flowability during sealing can be improved, which helps to improve the filling performance.

[0223] [wax]

[0224] The epoxy resin composition particles may contain wax as a release agent, as needed.

[0225] 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.

[0226] The amount of wax incorporated relative to the total epoxy resin composition particles 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 composition particles 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 composition particles is preferably 1.5% by mass or less, more preferably 1.0% by mass or less. By incorporating wax within the above range, the obtained epoxy resin composition particles exhibit excellent flowability and filling properties during transfer molding.

[0227] [Coupled agent]

[0228] The epoxy resin composition particles may contain coupling agents such as silane coupling agents as needed.

[0229] Examples of coupling agents include epoxy silanes, amino silanes, ureosilanes, and mercaptosilanes.

[0230] Examples of epoxy silanes include γ-epoxypropoxypropyltriethoxysilane, γ-epoxypropoxypropyltrimethoxysilane, γ-epoxypropoxypropylmethyldimethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. Furthermore, examples of aminosilanes 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-phenylenediamine). Examples of ureosilanes include γ-ureopropyltriethoxysilane and hexamethyldisilazane. Potential aminosilane coupling agents are used to protect the primary amino group of an aminosilane by reacting it with a ketone or aldehyde. Furthermore, the aminosilane may have a secondary amino group. 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. These silane coupling agents can be combined with substances obtained by prior hydrolysis. One of these silane coupling agents can be used alone, or two or more can be used simultaneously.

[0231] 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.

[0232] As a lower limit for the content of coupling agents such as silane coupling agents that can be used in epoxy resin composition particles, it 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 composition particles. 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, as an upper limit for the content of coupling agents such as silane coupling agents, it 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 composition particles. 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, it is possible to prevent an increase in the water absorption of the cured epoxy resin composition particles.

[0233] [Other Additives]

[0234] In addition to the components described above, the epoxy resin composition particles of this embodiment may also contain other additives such as colorants, flame retardants, and stress-reducing agents, as needed. These can be used alone or in combination of two or more.

[0235] The embodiments of the present invention have been described above, but these are merely examples, and various configurations other than those described can 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.

[0236] The following shows a first reference configuration of this embodiment.

[0237] 1. An epoxy resin composition particle for use in magnet fixing.

[0238] The epoxy resin composition particles are characterized in that they contain:

[0239] Epoxy resin; and

[0240] Fiber or needle-like fillers,

[0241] The fracture toughness value (K1c) measured according to the following steps is 3.0 MPa·m. 1 / 2 above.

[0242] (step)

[0243] Using a transfer molding apparatus, a molded body is formed from the epoxy resin composition particles under molding conditions of 175°C mold temperature, 9.8 MPa injection pressure, and 120 seconds curing time.

[0244] Following the KIc method specified in ASTM D5045-14, the obtained molded body was made into a size of 50 mm in length, B5 mm in width, and W10 mm in thickness. A notch with a depth of 3.5 mm in the thickness direction was formed in the center of the length direction. It was cured at 175°C for 4 hours to obtain a cured product. Then, a scratch with a depth of 0.1 mm in the thickness direction was applied to the front end of the notch of the cured product with a razor to produce a test piece with a total crack length a = 3.6 mm.

[0245] Then, for the obtained test pieces, a three-point bending test was performed using a tensile compression testing machine under the conditions of a measurement temperature of 25℃, 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 The maximum load is (N).

[0246] KI C =(P Q ×S) / (B×W) 3 / 2 ))×f(a / W)

[0247] 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 )

[0248] 2. The epoxy resin composition particles according to 1, characterized in that:

[0249] The number-average fiber length of the fibrous or needle-like filler, measured according to step A below, is 5 μm to 500 μm.

[0250] (Step A)

[0251] After dissolving the epoxy resin composition particles 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. Starting with the filler with the longest fiber length, the average fiber length of 100 fillers was taken as the number-average fiber length.

[0252] 3. The epoxy resin composition particles according to 1. or 2, characterized in that:

[0253] When the number-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,

[0254] L / D is between 3 and 100.

[0255] (Step A)

[0256] After dissolving the epoxy resin composition particles 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. Measurements were taken sequentially starting with the filler with the longest fiber length, and the average value of 100 fillers was taken as the number-average fiber length.

[0257] (Step B)

[0258] Using a scanning electron microscope, the cross-sections of 100 fibrous fillers were measured from the cross-sections of the epoxy resin composition particles, and the average of the minimum diameters of each fiber cross-section was determined as the number-average fiber diameter.

[0259] 4. The epoxy resin composition particles according to any one of 1 to 3, characterized in that:

[0260] The fibrous or needle-like filler contains 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.

[0261] 5. The epoxy resin composition particles according to any one of 1 to 4, characterized in that:

[0262] The spiral flow measured according to the following steps is 30 cm or more.

[0263] (step)

[0264] Using a low-pressure transfer molding machine, the epoxy resin composition particles were injected into a spiral flow measurement mold according to EMMI-1-66 under the conditions of mold temperature 175°C, injection pressure 6.9 MPa, and curing time 120 seconds, and the flow length (cm) was measured.

[0265] 6. The epoxy resin composition particles according to any one of 1 to 5, characterized in that:

[0266] In the epoxy resin composition particles, the content of the fibrous or needle-like filler is more than 5% by mass and less than 80% by mass in 100% by mass.

[0267] 7. The epoxy resin composition particles according to any one of 1 to 6, characterized in that:

[0268] The epoxy resin contains cresol varnish-type epoxy resin and / or bisphenol A type epoxy resin.

[0269] 8. The epoxy resin composition particles according to any one of 1 to 7, characterized in that:

[0270] The epoxy resin composition particles contain one or more curing catalysts selected from imidazole-based catalysts and phosphorus-based catalysts.

[0271] 9. Epoxy resin composition particles according to any one of 1 to 8, characterized in that:

[0272] The epoxy resin composition particles are used to form briquettes through the following steps: feeding the epoxy resin composition particles to a heated extruder and mixing them while they melt to obtain an epoxy resin molding material; and continuously extruding the molten epoxy resin molding material from an opening at the front end of the extruder and cutting the epoxy resin molding material to obtain briquettes.

[0273] 10. A pressing block, characterized in that:

[0274] The compressed block is formed using epoxy resin composition particles according to any one of 1 to 9.

[0275] The pressing block has a diameter of 5cm. 3 Above 1500cm 3 The following volumes.

[0276] 11. A method for manufacturing a columnar compression block, characterized in that it comprises:

[0277] The process of preparing epoxy resin composition particles according to any one of 1 to 9;

[0278] The process of feeding the epoxy resin composition particles into a heated extruder and mixing them while melting them to obtain an epoxy resin molding material; and

[0279] The process of continuously extruding molten epoxy resin molding material from the opening at the front end of an extruder and cutting the epoxy resin molding material to obtain columnar briquettes.

[0280] The cross-sectional area of ​​the columnar pressure block is 3 cm². 2 Above 100cm 2 the following.

[0281] The following shows a second reference configuration of this embodiment.

[0282] 1. An epoxy resin composition particle used for any of the following: magnet fixing, electronic control unit sealing, coil sealing, or stator core sealing.

[0283] The epoxy resin composition particles are characterized in that they contain:

[0284] Epoxy resin; and

[0285] Fiber-like or needle-like fillers.

[0286] 2. The epoxy resin composition particles according to 1, characterized in that:

[0287] The number-average fiber length of the fibrous or needle-like filler, measured according to step A below, is 5 μm to 500 μm.

[0288] (Step A)

[0289] After dissolving the epoxy resin composition particles 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. Measurements were taken sequentially starting with the filler with the longest fiber length, and the average value of 100 fillers was taken as the number-average fiber length.

[0290] 3. The epoxy resin composition particles according to 1. or 2, characterized in that:

[0291] When the number-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,

[0292] L / D is between 3 and 100.

[0293] (Step A)

[0294] After dissolving the epoxy resin composition particles 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. Starting with the filler with the longest fiber length, the average fiber length of 100 fillers was taken as the number-average fiber length.

[0295] (Step B)

[0296] Using a scanning electron microscope, the cross-sections of 100 fibrous fillers were measured from the cross-sections of the epoxy resin composition particles, and the average of the minimum diameters of each fiber cross-section was determined as the number-average fiber diameter.

[0297] 4. The epoxy resin composition particles according to any one of 1 to 3, characterized in that:

[0298] The fibrous or needle-like filler contains 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.

[0299] 5. The epoxy resin composition particles according to any one of 1 to 4, characterized in that:

[0300] The spiral flow measured according to the following steps is 30 cm or more.

[0301] (step)

[0302] Using a low-pressure transfer molding machine, the epoxy resin composition particles were injected into a spiral flow measurement mold according to EMMI-1-66 under the conditions of mold temperature 175°C, injection pressure 6.9 MPa, and curing time 120 seconds, and the flow length (cm) was measured.

[0303] 6. The epoxy resin composition particles according to any one of 1 to 5, characterized in that:

[0304] In the epoxy resin composition particles, the content of the fibrous or needle-like filler is more than 5% by mass and less than 80% by mass in 100% by mass.

[0305] 7. The epoxy resin composition particles according to any one of 1 to 6, characterized in that:

[0306] The epoxy resin contains cresol varnish-type epoxy resin and / or bisphenol A type epoxy resin.

[0307] 8. The epoxy resin composition particles according to any one of 1 to 7, characterized in that:

[0308] The epoxy resin composition particles contain one or more curing catalysts selected from imidazole-based catalysts and phosphorus-based catalysts.

[0309] 9. Epoxy resin composition particles according to any one of 1 to 8, characterized in that:

[0310] The epoxy resin composition particles are used to form briquettes through the following steps: feeding the epoxy resin composition particles to a heated extruder and mixing them while they melt to obtain an epoxy resin molding material; and continuously extruding the molten epoxy resin molding material from an opening at the front end of the extruder and cutting the epoxy resin molding material to obtain briquettes.

[0311] 10. A pressing block, characterized in that:

[0312] The compressed block is formed using epoxy resin composition particles according to any one of 1 to 9.

[0313] The pressing block has a diameter of 5cm. 3 Above 1500cm 3 The following volumes.

[0314] 11. A method for manufacturing a columnar compression block, characterized in that it comprises:

[0315] The process of preparing epoxy resin composition particles according to any one of 1 to 9;

[0316] The process of feeding the epoxy resin composition particles into a heated extruder and mixing them while melting them to obtain an epoxy resin molding material; and

[0317] The process of continuously extruding molten epoxy resin molding material from the opening at the front end of an extruder and cutting the epoxy resin molding material to obtain columnar briquettes.

[0318] The cross-sectional area of ​​the columnar pressure block is 3 cm². 2 Above 100cm 2 the following.

[0319] Example

[0320] The present invention will now be described in detail with reference to the embodiments, but the present invention is not limited in any way by the description of these embodiments.

[0321] (1) First implementation method

[0322] (Examples 1-6, Comparative Example 1)

[0323] <Preparation of Epoxy Resin Composition Particles>

[0324] The mixture of materials obtained by combining the components according to the proportions shown in Table 1 below is kneaded using a heated roller, and the cooled, sheet-like mixture is pulverized to obtain epoxy resin composition particles (granular molding materials).

[0325] In addition, the mixing conditions for the heating roller are: rotation speed 20 rpm, temperature 120℃, and mixing time 5 to 10 minutes.

[0326] The detailed information of each component in Table 1 is as follows.

[0327] • Fibrous or needle-like filler 1: Glass fiber (manufactured by NITTO BOSEKI CO., LTD., CS3E479)

[0328] • Fibrous or needle-like filler 2: Wollastonite fiber (manufactured by NYCO Minerals, Inc., NYAD325)

[0329] • Spherical inorganic filler 1: Glass beads (manufactured by UNITIKA LTD., UNIBEADSUB-13L)

[0330] • Spherical inorganic filler 2: fused silica (manufactured by Fumitec Co., Ltd., FMT-15C)

[0331] • Colorant: Carbon black (manufactured by Mitsubishi Chemical Corporation, #750B)

[0332] • Low-stress agent: Epoxy-polyether modified silicone oil (manufactured by Dow Corning Toray Co., Ltd., FZ-3730)

[0333] • Epoxy resin: Cresol phenolic resin varnish type epoxy resin (manufactured by DIC Corporation, N-673), softening point 78℃

[0334] • Hardener 1: Phenolic hardener (phenolic resin for varnish type, manufactured by Sumitomo Bakelite Co., Ltd., PR-51470) softening point 104℃

[0335] • Hardener 2: Phenolic hardener (phenolic resin of varnish type, manufactured by Sumitomo Bakelite Co., Ltd., PR-HF-3) softening point 80℃

[0336] • Curing catalyst: Imidazole-based catalyst (2-phenyl-4,5-dihydroxyimidazole, manufactured by Shikoku Chemicals Corporation, 2PHZ-PW)

[0337] • Release agent: Ester wax (manufactured by Clariant Chemicals Japan KK, LICOWAX OP)

[0338] • Coupling agent: Aminosilane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., KBE-903)

[0339] <Number Average Fiber Length>

[0340] After dissolving the epoxy resin composition particles 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. Starting with the filler with the longest fiber length, the average fiber length of 100 fillers was taken as the number-average fiber length (μm).

[0341] [Table 1]

[0342]

[0343] The obtained epoxy resin composition particles were evaluated for the following items.

[0344] Spiral Flow

[0345] Using a low-pressure transfer molding machine (manufactured by KOHTAKI Corporation, KTS-15), the obtained epoxy resin composition particles were injected into a spiral flow measurement mold according to EMMI-1-66 under the conditions of mold temperature 175°C, injection pressure 6.9MPa, and holding time 120 seconds, and the flow length was measured.

[0346] <Bending Test: Flexural Modulus>

[0347] The epoxy resin composition particles obtained above were compressed into tablets to obtain briquettes. Using a transfer molding machine, the obtained briquettes were injection molded under the conditions of mold temperature 175°C, injection pressure 9.8 MPa, and curing time 120 seconds to obtain test pieces in the form of cured products with a width of 10 mm × thickness of 4 mm × length of 80 mm.

[0348] The flexural modulus (GPa) of the test piece at room temperature was measured according to JIS K 6911.

[0349] <K1c>

[0350] Using a transfer molding apparatus, a molded body is formed from the epoxy resin composition particles under molding conditions of 175°C mold temperature, 9.8 MPa injection pressure, and 120 seconds curing time.

[0351] Following the KIc method specified in ASTM D5045-14, the obtained molded body was made into a size of 50 mm in length, B5 mm in width, and W10 mm in thickness. A notch with a depth of 3.5 mm in the thickness direction was formed in the center of the length direction. It was cured at 175°C for 4 hours to obtain a cured product. Then, a scratch with a depth of 0.1 mm in the thickness direction was applied to the front end of the notch of the cured product with a razor to produce a test piece with a total crack length a = 3.6 mm.

[0352] Then, as Figure 3 As shown in the summary, a tensile compression testing machine (STB-1225S Tensilon manufactured by ORIENTEC Co., Ltd.) was used to conduct a three-point bending test on the obtained test specimen 10 under the conditions of a measurement 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 QThis represents the maximum load (N). Additionally... Figure 3 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.

[0353] KI C =(P Q ×S) / (B×W) 3 / 2 ))×f(a / W)

[0354] 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 )

[0355] 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 6 are shown in Table 1.

[0356] Based on the results above, it can be seen that the epoxy resin composition particles of Examples 1 to 6 in Table 1 exhibit a higher flexural modulus compared to Comparative Example 1. Furthermore, it can be seen that the epoxy resin composition particles of Examples 1 to 6 in Table 1 also demonstrate excellent fracture toughness. The epoxy resin composition particles of Examples 1 to 6 in Table 1 are preferably suitable for magnet fixing, electronic control unit sealing, coil sealing, or stator core sealing.

[0357] (2) Second implementation method

[0358] (Examples 1-5, Comparative Example 1)

[0359] <Preparation of Epoxy Resin Composition Particles>

[0360] The mixture of materials obtained by combining the components according to the proportions shown in Table 2 below is kneaded using a heated roller, and the cooled, sheet-like mixture is pulverized to obtain epoxy resin composition particles (granular molding materials).

[0361] In addition, the mixing conditions for the heating roller are: rotation speed 20 rpm, temperature 120℃, and mixing time 5 to 10 minutes.

[0362] (Comparative Example 2)

[0363] Under the mixing conditions of heated rollers, the temperature was set to 90°C. Otherwise, the same procedure as in Example 1 was followed according to the proportions and components in Table 2 to obtain epoxy resin composition particles (granular molding material).

[0364] The detailed information for each component in Table 2 is as follows.

[0365] • Fibrous or needle-like filler 1: Glass fiber (manufactured by NITTO BOSEKI CO., LTD., CS3E479)

[0366] • Fibrous or needle-like filler 2: Wollastonite fiber (manufactured by NYCO Minerals, Inc., NYAD325)

[0367] • Spherical inorganic filler 1: Glass beads (manufactured by UNITIKA LTD., UNIBEADSUB-13L)

[0368] • Spherical inorganic filler 2: fused silica (manufactured by Fumitec Co., Ltd., FMT-15C)

[0369] • Colorant: Carbon black (manufactured by Mitsubishi Chemical Corporation, #750B)

[0370] • Low-stress agent: Epoxy-polyether modified silicone oil (manufactured by Dow Corning Toray Co., Ltd., FZ-3730)

[0371] • Epoxy resin: Cresol phenolic resin varnish type epoxy resin (manufactured by DIC Corporation, N-673), softening point 78℃

[0372] • Hardener 1: Phenolic hardener (phenolic resin for varnish type, manufactured by Sumitomo Bakelite Co., Ltd., PR-51470) softening point 104℃

[0373] • Hardener 2: Phenolic hardener (phenolic resin of varnish type, manufactured by Sumitomo Bakelite Co., Ltd., PR-HF-3) softening point 80℃

[0374] • Curing catalyst: Imidazole-based catalyst (2-phenyl-4,5-dihydroxyimidazole, manufactured by Shikoku Chemicals Corporation, 2PHZ-PW)

[0375] • Release agent: Ester wax (manufactured by Clariant Chemicals Japan KK, LICOWAX OP)

[0376] • Coupling agent: Aminosilane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., KBE-903)

[0377] <Number Average Fiber Length>

[0378] After dissolving the epoxy resin composition particles 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. Starting with the filler with the longest fiber length, the average fiber length of 100 fillers was taken as the number-average fiber length (μm).

[0379] [Table 2]

[0380]

[0381] The following items were evaluated on the epoxy resin composition particles obtained in Table 2.

[0382] Spiral Flow

[0383] Using a low-pressure transfer molding machine (manufactured by KOHTAKI Corporation, KTS-15), the obtained epoxy resin composition particles were injected into a spiral flow measurement mold according to EMMI-1-66 under the conditions of mold temperature 175°C, injection pressure 6.9MPa, and holding time 120 seconds, and the flow length was measured.

[0384] <Bending Test: Flexural Modulus>

[0385] The epoxy resin composition particles obtained above were compressed into tablets to obtain briquettes. Using a transfer molding machine, the obtained briquettes were injection molded under the conditions of mold temperature 175°C, injection pressure 9.8 MPa, and curing time 120 seconds to obtain test pieces in the form of cured products with a width of 10 mm × thickness of 4 mm × length of 80 mm.

[0386] The flexural modulus (GPa) of the test piece at room temperature was measured according to JIS K 6911.

[0387] <K1c>

[0388] Using a transfer molding apparatus, a molded body is formed from the epoxy resin composition particles under molding conditions of 175°C mold temperature, 9.8 MPa injection pressure, and 120 seconds curing time.

[0389] Following the KIc method specified in ASTM D5045-14, the obtained molded body was made into a size of 50 mm in length, B5 mm in width, and W10 mm in thickness. A notch with a depth of 3.5 mm in the thickness direction was formed in the center of the length direction. It was cured at 175°C for 4 hours to obtain a cured product. Then, a scratch with a depth of 0.1 mm in the thickness direction was applied to the front end of the notch of the cured product with a razor to produce a test piece with a total crack length a = 3.6 mm.

[0390] Then, as Figure 3 As shown in the summary, a three-point bending test was performed on the obtained test specimen 10 using a tensile compression testing machine (STB-1225S Tensilon manufactured by ORIENTEC Co., Ltd.) under the conditions of a measurement 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 3 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.

[0391] KI C =(P Q ×S) / (B×W) 3 / 2 ))×f(a / W)

[0392] 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 )

[0393] The fracture toughness values ​​calculated above are shown in Table 1.

[0394] <Evaluation of filling time gaps>

[0395] Forty sheets of electromagnetic steel with a diameter of 130 mm and a thickness of 0.35 mm are stacked together, and magnets are inserted into the holes of the stacked steel sheets.

[0396] The above unit is taken as 1 segment, and 5 segments with different heights are stacked in total by staggering the phase of the circumference by 2mm, thereby preparing a rotor structure with a skew structure.

[0397] The workpiece is mounted on the mold, and the epoxy resin composition particles described above are injected into the holes and the space between the magnets in the rotor structure using a transfer molding machine under the conditions of mold temperature 175°C, injection pressure 4MPa, and holding time 180 seconds.

[0398] For each segment of the obtained molded body, a gap gauge is used to confirm whether there is a gap.

[0399] A situation where a gap gauge of 0.02 mm cannot be inserted is rated as good, and a situation where a gap gauge of more than 0.02 mm can be inserted is rated as poor.

[0400] In the evaluation of the filling time gaps described above, good results were shown in Examples 1 to 5, while poor results were shown in Comparative Examples 1 and 2.

[0401] Based on the results above, it can be seen that the epoxy resin composition particles of Examples 1 to 5 in Table 2 have a higher K1c value compared with Comparative Examples 1 and 2, and show that they can suppress the generation of gaps when filled in the skewed structure.

[0402] The epoxy resin composition particles of Examples 1 to 5 in Table 2 are preferably used for magnet fixation.

[0403] This application claims priority based on Japanese Application No. 2023-071045 and Japanese Application No. 2023-071046, both filed on April 24, 2023, and incorporates the entire contents of their disclosures herein.

[0404] Explanation of reference numerals in the attached figures

[0405] 1. Epoxy resin composition particles; 2. Hopper; 41. Heater; 42. Screw; 43. Barrel; 43a. Feed side barrel; 5. Die; 51. Temperature regulator; 6. Extruded material; 10. Test piece; 12. Load pin; 14. Circular pivot; 100. Injection molding apparatus; 15. Mold; 16. Mold cavity; 20. Injection molding machine; 21. Barrel; 22. Screw; 23. Hopper; 24. Heater; 25. Nozzle; 26. Backflow valve; 30. On-board electronic control unit; 32. Wiring board; 34. Sealing resin; 36. Electronic components; 38. Connecting terminal; 40. Through hole.

Claims

1. An epoxy resin composition particle for use in any of the following applications: magnet fixing, electronic control unit sealing, coil sealing, or stator core sealing. The epoxy resin composition particles are characterized in that they contain: Epoxy resin; and Fiber-like or needle-like fillers.

2. An epoxy resin composition particle for use in magnet fixing. The epoxy resin composition particles are characterized in that they contain: Epoxy resin; and Fiber or needle-like fillers, The fracture toughness value (K1c) measured according to the following step i is 3.0 MPa·m. 1 / 2 above, (Step i) Using a transfer molding apparatus, a molded body was formed from the epoxy resin composition particles under molding conditions of 175°C mold temperature, 9.8 MPa injection pressure, and 120 seconds curing time. Following the KIc method specified in ASTM D5045-14, the obtained molded body was made into a size of 50 mm in length, B5 mm in width, and W10 mm in thickness. A notch with a depth of 3.5 mm in the thickness direction was formed in the center of the length direction. It was cured at 175°C for 4 hours to obtain a cured material. Then, a scratch with a depth of 0.1 mm in the thickness direction was applied to the front end of the notch of the cured material with a razor to produce a test piece with a total crack length a = 3.6 mm. Then, for the obtained test pieces, a three-point bending test was performed using a tensile compression testing machine under the conditions of a measurement temperature of 25℃, a speed of 10mm / min, and a support distance S=40mm. The fracture toughness value (K1c (MPa·m)) was calculated according to the following formula. 1 / 2 In the following formula, P Q The maximum load is (N). KEY C =((P Q ×S) / (B×W 3 / 2 ))×f(a / W) in, 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 ).

3. The epoxy resin composition particles according to claim 1 or 2, characterized in that: The number-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 epoxy resin composition particles 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 measured using an image analysis device. Starting with the filler with the longest fiber length, the average fiber length of 100 fillers is taken as the number-average fiber length.

4. The epoxy resin composition particles according to claim 1 or 2, characterized in that: When the number-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 epoxy resin composition particles 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, starting with the filler with the longest fiber length. The average value of 100 filler fibers was taken as the number-average fiber length. (Step B) Using a scanning electron microscope, the cross-sections of 100 fibrous fillers were measured from the cross-sections of the epoxy resin composition particles, and the average of the minimum diameters of each fiber cross-section was determined as the number-average fiber diameter.

5. The epoxy resin composition particles according to claim 1 or 2, characterized in that: The fibrous or needle-like filler contains 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.

6. The epoxy resin composition particles according to claim 1 or 2, characterized in that: The spiral flow measured according to step ii below is 30 cm or more. (Step ii) Using a low-pressure transfer molding machine, the epoxy resin composition particles were injected into a spiral flow measurement mold according to EMMI-1-66 under the conditions of mold temperature 175°C, injection pressure 6.9 MPa, and curing time 120 seconds, and the flow length (cm) was measured.

7. The epoxy resin composition particles according to claim 1 or 2, characterized in that: In the epoxy resin composition particles, the content of the fibrous or needle-like filler is more than 5% by mass and less than 80% by mass in 100% by mass.

8. The epoxy resin composition particles 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.

9. The epoxy resin composition particles according to claim 1 or 2, characterized in that: The epoxy resin composition particles contain one or more curing catalysts selected from imidazole-based catalysts and phosphorus-based catalysts.

10. The epoxy resin composition particles according to claim 1 or 2, characterized in that: The epoxy resin composition particles are used to form briquettes through the following steps: feeding the epoxy resin composition particles to a heated extruder and mixing them while they melt to obtain an epoxy resin molding material; and continuously extruding the molten epoxy resin molding material from an opening at the front end of the extruder and cutting the epoxy resin molding material to obtain briquettes.

11. The epoxy resin composition particles according to claim 1 or 2, characterized in that: For injection molding, in which an injection molding apparatus is used, the injection molding apparatus comprising an injection unit consisting of a barrel and a screw inserted into the barrel, and a mold having a cavity connected to the injection unit, wherein the epoxy resin composition particles are fed into the barrel for use.

12. The epoxy resin composition particles according to claim 1 or 2, characterized in that: Contains epoxy resin or curing agent with a softening point of less than 110℃.

13. A pressing block, characterized in that: The compressed block is formed using epoxy resin composition particles as described in claim 1 or 2. The pressing block has a diameter of 5cm. 3 Above 1500cm 3 The following volumes.

14. A method for manufacturing a columnar compression block, characterized in that, include: The process of preparing the epoxy resin composition particles according to claim 1 or 2; The process of feeding the epoxy resin composition particles into a heated extruder and mixing them while melting them to obtain an epoxy resin molding material; and The process of continuously extruding molten epoxy resin molding material from the opening at the front end of an extruder and cutting the epoxy resin molding material to obtain columnar briquettes. The cross-sectional area of ​​the columnar pressure block is 3 cm². 2 Above 100cm 2 the following.

15. A structure, characterized in that: The structure is formed using epoxy resin composition particles as described in claim 1 or 2.

16. A method for manufacturing a structure, wherein the method for manufacturing the structure as described in claim 15 is... In the manufacturing method of the structure, an injection molding apparatus is used, which includes an injection unit consisting of a barrel and a screw inserted into the barrel, and a mold with a cavity connected to the injection unit. The method for manufacturing the structure is characterized by comprising: The process of melting the epoxy resin composition particles in the barrel to prepare a molten resin composition; and The process of injecting molten resin composition from the front end of the screw to fill the mold cavity.

17. The method for manufacturing the structure according to claim 16, characterized in that: During the filling process, the temperature T at the front end of the screw is 60–100°C.

18. The method for manufacturing a structure according to claim 16, characterized in that: During the filling process, the temperature inside the mold cavity is 150–180°C.

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