Molding material composition for injection molding

Abstract

The present invention relates to a molding material composition that can be injection-molded.

Description

Molding material composition for injection molding

[0001] The present invention relates to a molding material composition capable of injection molding.

[0002]

[0003] Resin compositions for molding materials are used as sealing materials to protect semiconductor devices, automobile parts, and other components from external influences, and research is ongoing in various fields to improve the performance of molding materials. For example, Japanese Patent Application Laid-Open No. 2017-197620 relates to an epoxy resin composition for semiconductor sealing, comprising an epoxy resin, a phenol resin curing agent, and a filler. The composition discloses a technique for improving electrical connection reliability by controlling the content of the filler and the thermal elastic modulus of the cured product of the epoxy resin composition.

[0004] Meanwhile, transfer molding, a method for forming molding materials, offers the advantage of stability due to its insensitivity to various variables. However, its complexity, including the preform process (called "tampering") followed by the transfer molding process, reduces productivity. In contrast, injection molding offers superior productivity due to the absence of a tampering step, and its high accuracy and short cycle times offer superior productivity and cost-effectiveness.

[0005] In the case of injection molding, which has a simple manufacturing process and allows continuous operation, it is important that the epoxy molding compound (EMC) reaches the injection molding machine without clumping when fed into the hopper. In the conventional EMC manufacturing process, small particles are created through a 3Φ screen and a hammer mill, thereby maintaining a smooth pellet appearance, and the process temperature is set low at 15 to 20℃ to prevent powder clumping. However, in the case of injection molding, since injection molding is performed immediately after raw material input at a relatively high temperature of 25 to 30℃, the application of the conventional grinding method causes clumping due to fine powder and powder clumping due to the use of a resin with a low softening point. This causes clumping within the hopper during injection molding, which causes problems with continuous operation.

[0006] Accordingly, there is a need for development of a molding material composition that prevents clumping and has excellent continuous workability during injection molding.

[0007]

[0008] The present invention provides a molding material composition that prevents clumping and has excellent continuous workability during injection molding.

[0009]

[0010] The present invention provides a molding material composition for injection molding, comprising: an epoxy resin having a softening point of 60 to 80°C and an epoxy equivalent weight (EEW) of 100 to 250 g / eq; a curing agent having a softening point of 70 to 95°C; a filler; and a release agent.

[0011]

[0012] The present invention provides a molding material composition that prevents powder agglomeration within a hopper during injection molding and exhibits excellent continuous workability. The molding material composition according to the present invention is applicable to injection molding, and simplifies the manufacturing process by omitting the preform step required in conventional transfer molding. In addition, the molding material composition according to the present invention improves price competitiveness and workability by enabling continuous processing. In addition, the molding material composition according to the present invention provides excellent releasability. Since the molding material composition of the present invention exhibits high thermal conductivity through the use of a thermosetting resin, it is applicable to motors and battery structural materials for electric vehicles, etc.

[0013]

[0014] The present invention will be described in detail below. However, it is not limited to the following description, and each component may be modified or selectively mixed as needed. Therefore, it should be understood that all modifications, equivalents, and alternatives included within the spirit and technical scope of the present invention are included.

[0015] The “softening point” used in this specification is measured by a conventional method known in the art, and can be measured, for example, using a dropping point meter (Dropping Point system calorimetry DP70) from Mettler Toledo. The “viscosity” is measured by a conventional method known in the art, and can be measured, for example, using a Brookfield viscometer at room temperature (25°C). “Particle size (D 50 )” is measured by a conventional method known in the art, and can be measured, for example, by laser light scattering (LLS).

[0016]

[0017] The molding material composition according to the present invention comprises an epoxy resin, which is a thermosetting resin, a curing agent, a filler, and a release agent. The present invention utilizes an epoxy resin having a specific softening point and epoxy equivalent weight, and a curing agent having a specific softening point, thereby preventing powder clumping within the hopper during injection, thereby improving continuous workability. Furthermore, the molding material composition of the present invention prevents contamination of manufacturing equipment, thereby reducing maintenance costs associated with cleaning or replacement.

[0018]

[0019] epoxy resin

[0020] The molding material composition of the present invention comprises an epoxy resin. The epoxy resin is used as a main resin, and upon reaction with a curing agent and curing, forms a three-dimensional network structure, thereby imparting strong and solid adhesion to the adherend and heat resistance, chemical resistance, and electrical insulation properties.

[0021] As the above epoxy resin, an epoxy resin commonly used in the relevant technical field can be used. Non-limiting examples of usable epoxy resins include bisphenol A type epoxy resins, alicyclic epoxy resins, cresol novolac epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, naphthalene type epoxy resins, anthracene epoxy resins, tetramethyl biphenyl type epoxy resins, phenol novolac epoxy resins, bisphenol A novolac epoxy resins, bisphenol S novolac epoxy resins, biphenyl novolac epoxy resins, naphthol novolac epoxy resins, naphthol phenol cocondensed novolac epoxy resins, naphthol cresol cocondensed novolac epoxy resins, aromatic hydrocarbon formaldehyde resin modified phenol resin epoxy resins, triphenyl methane type epoxy resins, tetraphenyl ethane type epoxy resins, dicyclopentadiene type epoxy resins, dicyclopentadiene phenol addition reaction epoxy resins, biphenyl type epoxy resins, phenol aralkyl type epoxy resins, multifunctional phenol resins, and naphthol. There are aralkyl type epoxy resins, etc., and one or more of these may be included.

[0022] For example, the epoxy resin may include a cresol novolac type epoxy resin, for example, a formaldehyde polymer with (chloromethyl)oxirane and 2-methylphenol (Cas No. 0029690-82-2). In this case, better heat resistance, chemical resistance, and electrical insulation properties can be secured.

[0023] The above epoxy resin may be used having a softening point of 60 to 80°C, for example, 60 to 70°C. If the softening point is below the above-mentioned range, the resin becomes soft and brittle during the high-temperature injection molding process, which reduces dispersibility, and the filler may clump, causing the composition to clump in the hopper. As a result, the injection molding transport device may become clogged, preventing proper ejection, which may reduce moldability, or the efficiency of the production process may decrease due to frequent cleaning of the equipment. On the other hand, if the softening point exceeds the above-mentioned range, the softening of the resin may be insufficient, increasing the viscosity and reducing the flowability. As a result, the composition may not spread sufficiently into the mold during molding, which may cause an underfill phenomenon at the edges, etc.

[0024] The epoxy resin may be used having an epoxy equivalent weight (EEW) of 100 to 250 g / eq, for example, 180 to 220 g / eq. If the epoxy equivalent weight is less than the above-mentioned range, it may react with the curing agent at a high density, resulting in poor moisture resistance reliability. If it exceeds the above-mentioned range, it may react with the curing agent at a low density, resulting in insufficient curing, resulting in poor curing properties and the molding material may become brittle.

[0025] The above epoxy resin may be used with a viscosity (150°C) of 200 to 400 cps, for example, 240 to 320 cps. If the viscosity is below the above-mentioned range, excessive bleed flush may occur during molding, and if it exceeds the above-mentioned range, flowability may be reduced, resulting in an underfill phenomenon during molding.

[0026] Based on the total weight of the molding material composition of the present invention, the content of the epoxy resin may be 0.5 to 15 wt%, for example, 1 to 10 wt%. If the content of the epoxy resin is less than the above-mentioned range, adhesion, flowability, and moldability may be reduced, and if it exceeds the above-mentioned range, the reliability of the molding material may be deteriorated due to an increase in moisture absorption, and the strength may be reduced due to a relative decrease in the filler content.

[0027]

[0028] hardener

[0029] The molding material composition of the present invention includes a curing agent. The curing agent reacts with the epoxy resin to promote curing of the composition.

[0030] The curing agent may be a curing agent known in the art that undergoes a curing reaction with an epoxy resin, and the curing agent may be a phenol-based compound having two or more phenolic hydroxyl groups in one molecule. Non-limiting examples of curing agents that can be used include phenol novolac resins, cresol novolac resins, phenol aralkyl resins, and multifunctional phenol compounds, and the curing agent may include one or more of these. For example, the curing agent may include a phenol novolac-based curing agent, for example, a phenol polymer with formaldehyde (Cas No. 0009003-35-4).

[0031] The above curing agent may be one having a softening point of 70 to 95°C, for example, 80 to 90°C. If the softening point is below the aforementioned range, the curing agent becomes soft and brittle during the high-temperature injection molding process, which reduces dispersibility, and the filler may clump, causing the composition to clump together in the hopper. As a result, the injection molding transport device may become clogged, preventing proper ejection, which may reduce moldability or reduce the efficiency of the production process due to frequent cleaning of the equipment. On the other hand, if the softening point exceeds the aforementioned range, the softening of the resin may be insufficient, increasing the viscosity and reducing the flowability. As a result, the composition may not spread sufficiently into the mold during molding, which may cause unfilled areas such as the edges.

[0032] The above-mentioned hardener may be used having a hydroxyl equivalent of 80 to 150 g / eq, for example, 100 to 120 g / eq. If the hydroxyl equivalent is less than the above-mentioned range, moisture resistance reliability may be poor, and if it exceeds the above-mentioned range, curing property may be poor.

[0033] The above-mentioned hardener may be used with a viscosity (150°C) of 100 to 1,000 cps, for example, 150 to 300 cps. If the viscosity is below the above-mentioned range, excessive bleed flush may occur during molding, and if it exceeds the above-mentioned range, the flowability may be reduced, resulting in an underfill phenomenon during molding.

[0034] The above-mentioned hardener may be used with an electrical conductivity of 9 ㎲ / ㎝ or less. If the electrical conductivity exceeds the above-mentioned range, the dielectric constant may increase, which may deteriorate reliability and electrical insulation properties.

[0035] Based on the total weight of the molding material composition, the content of the curing agent may be 1 to 20 wt%, for example, 1 to 10 wt%. If the content of the curing agent is less than the above-mentioned range, curability and moldability may be reduced, and if it exceeds the above-mentioned range, the reliability of the molding material may be deteriorated and the strength may be reduced due to increased moisture absorption.

[0036]

[0037] filling

[0038] The molding material composition of the present invention includes a filler. The filler serves to improve the strength and flowability of the molding material composition.

[0039] As the above-mentioned filler, any inorganic filler commonly used in the relevant technical field can be used without any particular restrictions. For example, inorganic fillers such as silica, silica nitride, alumina, aluminum nitride, and boron nitride can be used, and these can be used alone or in combination of two or more.

[0040] The shape of the above filler is not particularly limited, and both angular and spherical shapes can be used. For example, spherical silica particles, spherical alumina particles, or mixtures thereof can be used.

[0041] The above filler may include two or more types of fillers having different particle sizes. In this case, the moldability and workability of the molding material composition can be further improved. For example, the filler may have an average particle size (D 50 ) of a first filler (e.g., silica) having an average particle size (D) of 5 to 20 um, for example, 12 to 18 um. 50 ) may include a second filler (e.g., alumina) having a particle size of 20 to 40 um, for example, 22 to 29 um. For example, the filler may include 1 to 30 wt% of the first filler and 10 to 90 wt% of the second filler.

[0042] Based on the total weight of the molding material composition, the content of the filler may be 50 to 98 wt%, for example, 70 to 98 wt%. If the content of the filler is less than the aforementioned range, the moisture absorption of the cured product may increase, which may reduce the reliability of the molding material. If the content of the filler exceeds the aforementioned range, fluidity may decrease, resulting in poor moldability.

[0043]

[0044] Lee Hyung-je

[0045] The molding material composition of the present invention includes a release agent. The release agent can impart release properties to the injection molding material after it has been cured.

[0046] As the release agent, waxes such as paraffin wax, carnauba wax, polyethylene wax, and ester wax; silicone oils such as double-terminal amine-modified silicone oil; and the like can be used. For example, the release agent can include double-terminal amine-modified silicone oil, ester wax, or a mixture thereof.

[0047] In general, a molding material can be formed through a process of molding and forming by pouring a molten molding material composition into a mold of a predetermined shape. In order to ensure releasability from the mold and compatibility with the epoxy resin, an epoxy-modified silicone oil may be included in the molding material composition. When an epoxy-modified silicone oil is used, the epoxy group contained in the epoxy-modified silicone oil reacts with the curing agent, so an excessive amount of curing agent must be used compared to the epoxy equivalent contained in the epoxy resin. If the content of the curing agent in the composition increases, the content of the filler decreases accordingly, which may cause problems such as a decrease in the strength of the sealant or a decrease in the insulating properties and thermal conductivity exerted by the filler. In addition, as the molecular weight of the epoxy-modified silicone oil that has reacted with the curing agent becomes bulky, the curing reactivity between the epoxy resin and the curing agent decreases, which may increase the manufacturing process time, lowering the process efficiency and adversely affecting the formability and strength. When a double-terminal amine-modified silicone oil is used as a release agent, it can provide excellent release properties from the mold after molding, thereby improving workability and moldability, thereby providing excellent appearance and reliability.

[0048] The above-described double-terminal amine-modified silicone oil contains amine groups as functional groups at both terminals, and the amine groups can participate in an epoxy curing reaction and bond with an epoxy resin through block copolymerization. This improves the strength of the cured molding material, and due to the silicone bonds formed within the molecules, dispersibility is improved and releasability from the mold can be improved. This prevents the composition from clumping in the hopper during transport within the injection molding machine, and allows the cured injection molding material to be released from the mold without damage to its appearance.

[0049] The amine equivalent of the above-described double-terminal amine-modified silicone oil may be 1,000 g / eq or more, for example, 1,000 to 13,000 g / eq, or another example, 1,500 to 6,000 g / eq. If the amine equivalent is less than the above-described range, the viscosity may be low, causing lumping within the hopper, and if it exceeds the above-described range, the viscosity may become excessively high, causing the double-terminal amine-modified silicone oil within the composition to remain in a lump without being dispersed, thereby causing gelation of the composition or reducing formability.

[0050] The viscosity (25 ℃) of the above-mentioned double-ended amine-modified silicone oil is 50 mm 2 / s can be more than that.

[0051] For example, the release agent may include a double-terminal amine-modified silicone oil and an ester wax. In this case, the release property may be better maintained even at high temperatures.

[0052] Based on the total weight of the molding material composition, the content of the release agent may be 0.1 to 1 wt%, for example, 0.1 to 0.5 wt%. If the content of the release agent is less than the aforementioned range, release properties may be insufficient, and if it exceeds the aforementioned range, workability may be reduced due to mold contamination and staining caused by the release agent.

[0053]

[0054] additives

[0055] The molding material composition of the present invention may additionally include additives commonly used in such compositions. Non-limiting examples of usable additives include coupling agents, colorants, catalysts, flame retardants, and the like.

[0056] Coupling agents promote bonding between inorganic and organic substances and enhance adhesion to metal substrates, and amino silanes, epoxy silanes, and the like can be used. Colorants are added to impart color to the molding material composition, and carbon black, Bengala, and the like can be used as the colorants. The catalysts are intended to improve curing speed and workability, and imidazole catalysts, phosphorus catalysts, and the like can be used. The flame retardants are intended to impart flame retardancy, and the like can be used as the flame retardant.

[0057] The above additives may be added within a content range known in the relevant technical field, and for example, may be included in an amount of 0.01 to 10 wt%, respectively, based on the total weight of the molding material composition, but is not limited thereto.

[0058]

[0059] The molding material composition according to the present invention can be manufactured by a conventional method known in the art, for example, a melt mixing method using a Banbury mixer, a kneader, a roll, a single-screw or twin-screw extruder, and a co-kneader. The molding material composition of the present invention is manufactured in a powder form, a granular form, etc., and can be molded using an injection molding machine. For example, in the case of a powder form or a granular form of a molding material composition, the above-described respective components are uniformly mixed, and then melt-mixed at a temperature of 80 to 130°C using a heat kneader, cooled to room temperature, pulverized into a powder state, and then subjected to a sieving process, but is not limited thereto.

[0060] The molding material composition according to the present invention may have a fine powder content of 0.5 mm or less of 1.0 wt% or less, for example, 0.00001 to 1.0 wt%. If the fine powder content exceeds the aforementioned range, powder agglomeration may occur in the hopper during injection.

[0061] The molding material composition having the above-described fine powder content range can be manufactured by controlling the grinding speed and screen size. For example, the grinding speed may be 1,000 to 1,500 RPM, and the screen size may be 4 to 8 Φ. By grinding at a low speed within the above-described range and separating using a large-sized screen, the fine powder content can be reduced during hammer mill grinding, thereby preventing powder clumping after grinding. If the grinding speed is less than the above-described range or the screen size is greater than the above-described range, the particle size of the molding material composition increases, which may cause clogging when transporting the molding material composition from the hopper to the barrel during injection molding, preventing the composition from being supplied evenly into the mold, thereby reducing moldability. On the other hand, if the grinding speed is more than the above-described range or the screen size is less than the above-described range, the particle size of the molding material composition may become fine or the particle distribution may become greater, which may increase the viscosity of the composition, or the powder may clump in the hopper, which may cause contamination of the equipment.

[0062]

[0063] Hereinafter, the present invention will be described in more detail through examples. However, the following examples are intended only to aid understanding of the present invention and are not intended to limit the scope of the present invention in any way.

[0064]

[0065] [Experimental Example 1-14]

[0066] After mixing each component according to the composition described in Table 1-2 below, the mixture was melt-mixed at a temperature of 100 to 130°C using a melt kneader, cooled to room temperature, and pulverized and separated according to the conditions of Table 1-2 below to manufacture a powder-type molding material composition for each experimental example.

[0067]

[0068]

[0069]

[0070]

[0071] Epoxy resin 1: Formaldehyde polymer with (chloromethyl)oxirane and 2-methylphenol (softening point 62 ℃, epoxy equivalent 202 g / eq, viscosity (150 ℃) 270 cps)

[0072] Epoxy resin 2: 2,2'-[[1-[4-[1-methyl-1-[4-(2oxiranylmethoxy)phenyl]ethyl]phenyl]ethylidene]bis(4,1phenyleneoxymethylene)]bisoxirane (Cas No. 115254-47-2, softening point 60.5 ℃, epoxy equivalent 210 g / eq, viscosity (150 ℃) 120 cps)

[0073] Epoxy resin 3: [2,2-[Methylenebis[(2,6-dimethyl-4,1-phenylene)oxy methylene]]bisoxirane (Cas No. 0093705-66-9, softening point 79 ℃, epoxy equivalent 192 g / eq, viscosity (150 ℃) 10 cps)

[0074] Epoxy resin 4: Formaldehyde polymer with (chloromethyl)oxirane and 2-methylphenol (softening point 52.5 ℃, epoxy equivalent 200 g / eq, viscosity (150 ℃) 115 cps)

[0075] Epoxy resin 5: 4,4-Bis(2,3-epoxypropoxy)-3,3,5,5-tetramethyl(1,1-biphenyl)(Cas No. 0085954-11-6, softening point 107.5 ℃, epoxy equivalent 187 g / eq, viscosity (150 ℃) 20 cps)

[0076] Epoxy resin 6: Formaldehyde, polymer with 1,1'-biphenyl and phenol, glycidyl ether (softening point 57 ℃, epoxy equivalent 277 g / eq, viscosity (150 ℃) 80 cps)

[0077] Epoxy resin 7: Formaldehyde, polymer with 1,1'-biphenyl and phenol, glycidyl ether (softening point 90 ℃, epoxy equivalent 240 g / eq, viscosity (150 ℃) 30 cps))

[0078] Hardener 1: Phenol polymer with formaldehyde (softening point 84 ℃, OH equivalent 107 g / eq, viscosity (150 ℃) 200 cps)

[0079] Curing agent 2: Phenol polymer with 4,4-bis(methoxymethyl)1,1-bisphenyl (Cas No. 0205830-20-2, softening point 70 ℃, OH equivalent 201.5 g / eq, viscosity (150 ℃) 70 cps)

[0080] Curing agent 3: 1,3-Benzenediol polymer with 4,4-bis(chloromethyl)-1,1-biphenyl and phenol (Cas No. 0918825-38-4, softening point 93 ℃, OH equivalent 135 g / eq, viscosity (150 ℃) 650 cps)

[0081] Hardener 4: Phenol polymer with formaldehyde (softening point 63 ℃, OH equivalent 169 g / eq, viscosity (150 ℃) 65 cps)

[0082] Hardener 5: Phenol polymer with formaldehyde (softening point 67 ℃, OH equivalent 103 g / eq, viscosity (150 ℃) 34 cps)

[0083] Hardener 6: Phenol polymer with formaldehyde (softening point 97 ℃, OH equivalent 106 g / eq, viscosity (150 ℃) 650 cps)

[0084] Filler: Silica (D 50 15 ㎛) and alumina (D 50 A mixture of 25.3 ㎛ (5:79.5 weight ratio)

[0085] Release agent 1: Double-terminal amine-modified silicone oil (amine equivalent 2,200 g / mol, Mw 4,400 g / mol)

[0086] Release agent 2: Double-terminal amine-modified silicone oil (amine equivalent 800 g / mol, Mw 1,600 g / mol)

[0087] Wax: Ester wax (melting point 81 ℃, saponification value 15-20 mgKOH / g)

[0088] Silane: Trimethoxy[3-(phenylamino)propyl]silane

[0089] Colorant: Carbon Black

[0090] Catalyst: A mixture of 2-phenyl-4-methyl-5-hydroxymethylimidazole, Tetraphenylphosphonium, and Tetrahydroxy Dinaphthalene (1:1 weight ratio)

[0091] Flame retardant: Magnesium hydroxide

[0092]

[0093] [Physical property evaluation]

[0094] The properties of the molding material composition manufactured in each experimental example were measured as follows, and the results are shown in Tables 3 and 4 below.

[0095]

[0096] Fine content of 0.5 mm or less

[0097] After passing the crushed powder of each experimental example through a 35 Mesh frame, the content of the powder passed was calculated compared to the content of the powder before passing.

[0098]

[0099] Powder clumps after grinding

[0100] After the crushed powder of each experimental example was left at 30°C for 1 hour, the presence or absence of powder clumping was visually observed.

[0101] [metewand]

[0102] Good: No powder clumping

[0103] NG: Powder clumping occurs

[0104]

[0105] Powder clumps in the hopper

[0106] After the powder of each experimental example was injected into the injection molding machine hopper, the presence or absence of clumping was visually observed during the continuous manufacturing process moving into the barrel.

[0107] [metewand]

[0108] Good: No cake phenomenon (rathole) or bridge phenomenon in raw materials

[0109] NG: Cake phenomenon (rathole) or bridge phenomenon in raw materials

[0110]

[0111] spiral flow

[0112] Spiral flow was measured using a spiral flow measurement mold (mold press temperature 175℃, transfer pressure 1,000±25 psi, transfer speed 1-4 inch / sec, curing time 120 sec) according to ASTM D 3123-72. If the spiral flow is less than 20 inches, viscosity increases and flowability decreases, which may cause underfilling of the mold during molding.

[0113]

[0114] gelation time

[0115] The composition of each experimental example was placed on a hot plate (170±3 ℃), a thin film was formed using a spatula, and the time until the film began to break as curing began was measured.

[0116]

[0117] Filling

[0118] The composition of each experimental example was injected into an injection molding facility at a temperature of 28°C and molded in a mold. Then, the shape of the cured molding material was visually observed to determine the filling property according to the following criteria.

[0119] [metewand]

[0120] Good: Forming molding material in the shape of a mold

[0121] NG: Non-formation of molding material in the mold shape (the composition is not filled at the side far from the composition inlet or at the edge of the mold)

[0122]

[0123]

[0124]

[0125]

[0126] As shown in Tables 3 and 4 above, it can be confirmed that the molding material compositions of Experimental Examples 1-6 according to the present invention prevent powder clumping after grinding and powder clumping in the hopper during injection, and have excellent filling properties. On the other hand, in the case of the molding material compositions of Experimental Examples 7-10 using an epoxy resin (epoxy resin 4-7) having a softening point and / or epoxy equivalent outside the scope of the present invention, and in the case of the molding material compositions of Experimental Examples 11-13 using a hardener (hardener 4-6) having a softening point outside the scope of the present invention, powder clumping occurred in the hopper after grinding and / or during injection, or the filling properties were poor. On the other hand, in the case of the molding material composition of Experimental Example 14 using a release agent having a low amine equivalent (release agent 2), powder clumping was prevented after grinding and had excellent filling properties, but powder clumping occurred in the hopper during injection.

[0127]

[0128] The present invention provides a molding material composition that prevents clumping and has excellent continuous workability during injection molding.

[0129]

Claims

1. A molding material composition for injection molding comprising an epoxy resin having a softening point of 60 to 80°C and an epoxy equivalent weight (EEW) of 100 to 250 g / eq; a curing agent having a softening point of 70 to 95°C; a filler; and a release agent.

2. In the first paragraph, the epoxy resin has a viscosity (150°C) of 200 to 400 cps, A molding material composition for injection molding, wherein the hydroxyl equivalent of the above-mentioned curing agent is 80 to 150 g / eq, the viscosity (150 ℃) is 100 to 1,000 cps, and the electrical conductivity is 9 ㎲ / cm or less.

3. In the first paragraph, the release agent is a molding material composition for injection molding comprising a double-terminal amine-modified silicone oil, wax, or a mixture thereof.

4. In the third paragraph, the amine equivalent of the double-terminal amine-modified silicone oil is 1,000 g / eq or more, and the viscosity (25 ℃) is 50 mm 2 / s or more injection molding material composition.

5. A molding material composition for injection molding, comprising, based on the total weight of the molding material composition in paragraph 1, 0.5 to 15 wt% of the epoxy resin, 1 to 20 wt% of the curing agent, 50 to 98 wt% of the filler, and 0.1 to 1 wt% of the release agent.

6. In the first paragraph, a molding material composition for injection molding, manufactured by mixing the epoxy resin, the hardener, the filler, and the release agent, melting and mixing, cooling to room temperature, grinding at a speed of 1,000 to 1,500 RPM, and separating with a screen of size 4 to 8 Φ, and having a fine powder content of 0.5 mm or less of 1.0 wt% or less.

Images