Composition for injection molding material

Abstract

The present invention relates to a composition for an injection-molding material, and vehicle components molded using same.

Description

Composition for injection molding molding material

[0001] The present invention relates to a composition for a molding material capable of injection molding and an automobile part molded using the same.

[0002]

[0003] Resin compositions for molding materials are used as sealing materials to protect semiconductor devices, automobile parts, etc. from the outside, and research is continuing 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, which includes 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 thermoelastic modulus of the cured product of the epoxy resin composition. However, molding material compositions using epoxy resin, a thermosetting resin, are applicable to compression type molding, C-molding, and lamination processes, but are difficult to use in injection molding processes.

[0004] In the case of injection molding, since the injection molding composition must remain in a plasticized state inside the molding machine for a long time, thermoplastic resins are mainly used rather than thermosetting resins that cure with heat. Thermoplastic resins have excellent productivity and are applied in various fields, and most plastic structural materials in use today are injection-molded products using thermoplastic resins. Recently, high thermal conductivity has been required for injection-molded structural materials. However, in the case of thermoplastic resins, it is difficult to manufacture molded products with a thermal conductivity of 1W or higher due to the characteristics of the manufacturing process, and there is a problem of deformation when exposed to high-temperature environments.

[0005] Therefore, development of a heat-dissipating coating material using a thermosetting resin instead of a thermoplastic resin is required.

[0006] Meanwhile, the non-solvent thermosetting resin composition is in a solid state and must be kept in a plasticized state (molten state) for a long time within the molding machine during injection molding. However, if it is continuously exposed to high temperatures (below 110°C) to maintain the plasticized state, a curing reaction may occur within the molding machine, which may cause the ejection part to become clogged or aggregates to form inside, which may reduce continuous workability and adversely affect moldability.

[0007] Accordingly, there is a need for development of a composition for molding materials that has excellent thermal conductivity as well as excellent continuous workability and ejection properties during injection molding.

[0008]

[0009] The present invention provides a composition for an injection molding molding material having excellent thermal conductivity, continuous workability and ejection properties during injection molding, and an automobile part molded using the same.

[0010]

[0011] The present invention provides a composition for an injection molding material comprising an epoxy resin, a curing agent, a filler and a catalyst, wherein the catalyst comprises an imidazole-based catalyst and a phosphorus-based catalyst.

[0012]

[0013] The present invention provides a composition for a molding material having excellent thermal conductivity, as well as excellent continuous workability and extrusion properties during injection molding. The composition for a molding material according to the present invention can produce a molded product having a thermal conductivity of 3W or higher, and thus can be applied to structural materials such as motor housings and battery pack cases that require high thermal conductivity (2.5W or higher) to control heat generated from motors and batteries used in electric vehicles.

[0014] In addition, the molding material composition according to the present invention can be applied to injection molding by maximally suppressing the curing of a thermosetting resin composition during a process of melting the resin with heat inside an injection molding machine, and continuous molding is possible.

[0015]

[0016] 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.

[0017] As used herein, “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 (D50)” is measured by a conventional method known in the art, and can be measured, for example, using laser light scattering (LLS).

[0018]

[0019] <Composition for molding material>

[0020] The composition for a molding material according to the present invention comprises an epoxy resin, which is a thermosetting resin, a curing agent, a filler, and a catalyst. The present invention controls the DSC reaction start temperature of the composition for a molding material measured by a differential scanning calorimeter (DSC) to exceed 110°C, the peak temperature of the DSC curve to exceed 157°C, and uses an imidazole catalyst and a phosphorus catalyst, thereby suppressing the composition for a molding material from being cured by heat when left to stand for a long time in an injection molding machine as much as possible, thereby providing a composition for a molding material having excellent continuous workability and ejection properties during injection molding.

[0021]

[0022] epoxy resin

[0023] 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.

[0024] 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.

[0025] For example, the epoxy resin is a polymer of (chloromethyl)oxirane and 2-methylphenol and formaldehyde (Formaldehyde polymer with (chloromethyl)oxirane and 2-methylphenol, Cas No. 0029690-82-2), a polymer of formaldehyde, 1,1'-biphenyl and phenol, glycidyl ether, 4,4-bis(2,3-epoxypropoxy)-3,3,5,5-tetramethyl(1,1-biphenyl), 2,7-naphthalenediol polymer with 2-(chloromethyl)oxirane and ar-benzyl derivatives. 2-(chloromethyl)oxirane, ar-benzyl derivs.) or mixtures thereof.

[0026] For example, the epoxy resin may include a formaldehyde polymer with (chloromethyl)oxirane and 2-methylphenol. In this case, better heat resistance, chemical resistance, and electrical insulation properties can be secured.

[0027] The above epoxy resin may be used having an epoxy equivalent weight (EEW) of 100 to 400 g / eq, for example, 180 to 230 g / eq. If the epoxy equivalent weight is less than the above-mentioned range, the cured density may increase, resulting in poor moisture resistance reliability. If the epoxy equivalent weight exceeds the above-mentioned range, the curing property may be poor.

[0028] 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.

[0029] Based on the total weight of the composition for molding materials 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 content of the filler.

[0030]

[0031] hardener

[0032] 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.

[0033] The curing agent may be any curing agent known in the art that undergoes a curing reaction with an epoxy resin. The curing agent may be a phenol-based compound having two or more phenolic hydroxyl groups in one molecule. Non-limiting examples of usable curing agents 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.

[0034] For example, the curing agent may include a phenol polymer with formaldehyde (Cas No. 0009003-35-4), a phenol polymer with 4,4-bis(methoxymethyl)1,1-bisphenyl, a phenol polymer with hydroxybenzaldehyde, or a mixture thereof.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] Based on the total weight of the composition for molding material, the content of the curing agent may be 2 to 20 wt%, for example 2 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.

[0039]

[0040] filling

[0041] 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.

[0042] 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.

[0043] 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.

[0044] The above filler may include two or more types of fillers having different particle sizes. In this case, the moldability and workability of the composition for molding materials can be further improved. For example, the filler may include a first filler (e.g., silica) having an average particle size (D50) of 5 to 20 um, for example, 12 to 18 um, and a second filler (e.g., alumina) having an average particle size (D50) of 20 to 40 um, for example, 22 to 29 um.

[0045] Based on the total weight of the composition for molding materials, the content of the filler may be 50 to 90 wt%, for example, 70 to 90 wt%. If the content of the filler is less than the aforementioned range, the moisture absorption of the cured product may increase, which may lower the reliability of the molding material. If the content of the filler exceeds the aforementioned range, fluidity may be reduced, resulting in poor moldability.

[0046]

[0047] catalyst

[0048] The molding material composition of the present invention comprises a catalyst, wherein the catalyst comprises an imidazole-based catalyst and a phosphorus-based catalyst. By including the two types of catalysts, the reaction start temperature and exothermic peak temperature of the molding material composition of the present invention are controlled, so that the reaction is promoted at 120°C or higher, and as a result, excellent continuous workability and ejection properties can be secured during injection molding.

[0049] The above imidazole catalyst may be used with a molecular weight of 160 g / mol or more, for example, 160 to 400 g / mol. If the molecular weight is less than the above-mentioned range, the curing reaction may begin within the injection molding machine due to a rapid catalytic reaction, which may reduce continuous workability. If the molecular weight is more than the above-mentioned range, the curing time may be prolonged due to an excessively slow catalytic reaction, which may take a considerable amount of time for curing even after discharging, which may reduce productivity.

[0050] For example, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,4-diamino-6-[2'-methylimidazol-[1']]-ethyl-s-triazine isocyanuric acid adduct, 2,4-diamino-6-[2'-methylimidazol-[1']]-ethyl-s-triazine, etc. can be used as the imidazole-based catalyst.

[0051] The above-mentioned phosphorus catalyst may be used with a molecular weight of 700 g / mol or more, for example, 700 to 1,000 g / mol. If the molecular weight is less than the above-mentioned range, a curing reaction may begin within the injection molding machine due to a rapid catalytic reaction, which may reduce continuous workability. If the molecular weight is more than the above-mentioned range, the curing time may be prolonged due to an excessively slow catalytic reaction, which may take a considerable amount of time for curing even after discharging, which may reduce productivity and deteriorate moldability.

[0052] For example, tetraphenylphosphonium, tetrahydroxy dinaphthalene, etc. can be used as the above-mentioned phosphorus catalyst.

[0053] For example, the catalyst may include 2-phenyl-4-methyl-5-hydroxymethylimidazole and tetraphenylphosphonium, tetrahydroxy dinaphthalene. In this case, better continuous workability and ejection properties can be secured during injection molding.

[0054] For example, the mixing ratio of the imidazole catalyst and the phosphorus catalyst may be 2:8 to 8:2 by weight. If the mixing ratio of the imidazole catalyst to the phosphorus catalyst is less than the above-mentioned range, the curing reaction may be slow, resulting in a decrease in H / H after molding, which may deteriorate workability. If it exceeds the above-mentioned range, the curing reaction may be too fast, which may cause problems with continuous operation during the injection process.

[0055] The above catalyst may further include a naphthalene-based latent catalyst, an amine-based compound, an organometallic compound, a boron compound, etc.

[0056] Based on the total weight of the composition for molding materials, the content of the catalyst may be 0.1 to 6 wt%, for example, 0.2 to 2 wt%. For example, based on the total weight of the composition for molding materials, the imidazole-based catalyst may be 0.05 to 3 wt%, for example, 0.1 to 1 wt%, and the phosphorus-based catalyst may be 0.05 to 3 wt%, for example, 0.1 to 1 wt%. If the content of the catalyst is less than the above-mentioned range, the curing speed may be too slow, which may lower workability and productivity, and if it exceeds the above-mentioned range, the curing reaction may be too fast, resulting in non-molding, or gelation may occur during the continuous manufacturing process.

[0057]

[0058] additives

[0059] 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, release agents, colorants, flame retardants, and the like.

[0060] Coupling agents promote bonding between inorganic and organic substances and improve adhesion to metal substrates, and amino silanes, epoxy silanes, etc. can be used. Release agents are added to secure releasability between the molding material formed after the injection molding molding material composition is cured and the mold, and examples of the release agents include waxes such as paraffin wax, carnauba wax, polyethylene wax, and ester wax; and silicone oils such as both-terminal amine-modified silicone oils. Colorants are added to provide color to the molding material composition, and examples of the colorants include carbon black, Bengala, etc. The flame retardant is added to provide flame retardancy, and examples of the flame retardant include metal hydroxides, etc.

[0061] 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 5 wt%, respectively, based on the total weight of the composition for molding materials, but is not limited thereto.

[0062]

[0063] The non-solvent thermosetting resin composition is in a solid state and must be kept in a plasticized state (molten state) for a long time within the molding machine during injection molding. However, if it is continuously exposed to high temperatures (below 110°C) to maintain the plasticized state, a curing reaction may occur within the molding machine, which may cause the ejection part to become clogged or aggregates to form inside, which may reduce continuous workability and adversely affect moldability.

[0064] The molding composition of the present invention has a DSC reaction start temperature exceeding 110°C as measured by a differential scanning calorimeter (DSC), and a DSC curve peak temperature exceeding 157°C. By controlling the reaction start temperature and exothermic peak temperature of the molding composition within the aforementioned ranges, the reaction is promoted at 120°C or higher, and as a result, excellent continuous workability and ejectability can be secured during injection molding.

[0065] For example, the composition for a molding material of the present invention may have a DSC reaction start temperature measured by a differential scanning calorimeter (DSC) of more than 110°C and less than 150°C, for example, more than 110°C and less than 140°C, and a peak temperature of the DSC curve of more than 157°C and less than 230°C, for example, more than 157°C and less than 200°C. In this case, excellent continuous workability and ejectability can be secured during injection molding, while further improving production efficiency.

[0066] 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.

[0067]

[0068] Semiconductor devices and automotive components

[0069] The present invention provides a semiconductor device molded using the aforementioned molding material composition. The semiconductor device may be a transistor, a diode, a microprocessor, a semiconductor memory, a power semiconductor, or the like.

[0070] In addition, the present invention provides a vehicle part molded using the aforementioned composition for a molding material. The vehicle part may be a housing of a motor used in an electric vehicle, a battery pack case, etc. In addition, the aforementioned composition for a molding material may be used as a molding material to fix and seal components within the vehicle part. For example, a permanent magnet may be inserted into a hollow space formed within a rotor core of a vehicle motor, and the composition for a molding material of the present invention may be filled between the hollow space and the permanent magnet to fix the permanent magnet within the rotor core. In addition, it may be used as a substitute for insulating paper used for electrical insulation within a stator, and it may also be used in a manner of molding the portion where the coil is wound instead of an impregnation process after coil winding of the stator.

[0071]

[0072] 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.

[0073]

[0074] [Experimental Example 1-11]

[0075] After mixing each component according to the composition described in Tables 1 and 2 below, the mixture was melt-mixed at a temperature of 100 to 130°C using a melt kneader, cooled to room temperature, pulverized into a powder state, and then subjected to a sieving process to manufacture a powder-type molding material composition for each experimental example.

[0076] Using a differential scanning calorimeter (DSC), the reaction start temperature and peak temperature were measured at a temperature increase rate of 10°C per minute from 30°C to 300°C, and the results are listed in Tables 1 and 2 below.

[0077]

[0078]

[0079]

[0080] Epoxy resin: Formaldehyde polymer with (chloromethyl)oxirane and 2-methylphenol (Cas No. 0029690-82-2, epoxy equivalent 202 g / eq, viscosity (150 ℃) 270 cps)

[0081] Curing agent: Phenol polymer with formaldehyde (Cas No. 0009003-35-4, equivalent weight 107 g / eq, viscosity (150 ℃) 220 cps)

[0082] Filler 1: Silica (D 50 15 ㎛)

[0083] Filler 2: Alumina (D 50 25.3 ㎛)

[0084] Catalyst 1: 2-phenyl-4-methyl-5-hydroxymethylimidazole (molecular weight 188.23 g / mol)

[0085] Catalyst 2: 2-Methylimidazole (molecular weight 82.10 g / mol)

[0086] Catalyst 3: 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidzole] (molecular weight 158.20 g / mol)

[0087] Catalyst 4: Tetraphenylphosphonium, Tetrahydroxy Dinaphthalene (molecular weight 818 g / mol)

[0088] Catalyst 5: Triphenylphosphine (molecular weight 658.6 g / mol)

[0089] Silane: Trimethoxy[3-(phenylamino)propyl]silane

[0090] Wax: Ester wax

[0091] Colorant: Carbon Black

[0092] Flame retardant: Magnesium hydroxide

[0093]

[0094] [Physical property evaluation]

[0095] 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.

[0096]

[0097] spiral flow

[0098] The molding material composition manufactured according to each experimental example was molded using a spiral flow mold in a heat transfer molding machine (pressure 70 kg / cm2, temperature 175 ℃, curing time 200 seconds), and then the flowability of the product was measured.

[0099]

[0100] gelation time

[0101] A small amount of the molding material composition manufactured according to each experimental example was spread widely and evenly on a gel timer, and the gelation time of the composition was measured.

[0102]

[0103] H / H

[0104] After completing the spiral flow measurement, the mold was opened and the high-temperature surface hardness of the molding material was measured using a hardness measuring device, Shore-D.

[0105]

[0106] thermal conductivity

[0107] After manufacturing a circular specimen measuring 30 mm in diameter x 2 mm in thickness, thermal conductivity was measured using a thermal conductivity measuring device. At this time, the specimen molding conditions were the same as the spiral flow conditions.

[0108]

[0109] Injection molding continuous operation

[0110] The composition for molding material manufactured in each experimental example was put into an injection molding facility, and continuous operation was performed for 1 hour. Then, the status of the nozzle, gate, mold, and molded product was observed to evaluate the continuous operation of injection molding.

[0111]

[0112]

[0113]

[0114] As shown in Tables 3 and 4 above, it was confirmed that the molding material compositions of Experimental Examples 1 to 5 according to the present invention exhibited excellent physical properties across all measured items. On the other hand, the molding material compositions of Experimental Example 6, which did not include an imidazole-based catalyst, and Experimental Examples 7 to 11, which had a peak temperature of 157°C or lower in the DSC curve, exhibited lower gel time, spiral flow value, and thermal conductivity than those of Experimental Examples 1 to 5, and it was confirmed that curing occurred in the injection molding machine or that continuous workability was reduced due to low high-temperature surface hardness.

[0115]

[0116] The present invention provides a composition for an injection molding molding material having excellent thermal conductivity, continuous workability and ejection properties during injection molding, and an automobile part molded using the same.

Claims

1. Contains epoxy resin, hardener, filler and catalyst, The above catalyst includes an imidazole-based catalyst and a phosphorus-based catalyst, A composition for injection molding molding material, wherein the DSC reaction start temperature measured by differential scanning calorimetry (DSC) exceeds 110°C and the peak temperature of the DSC curve exceeds 157°C.

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

3. A composition for injection molding material in claim 1, wherein the catalyst comprises an imidazole catalyst having a molecular weight of 160 g / mol or more and a phosphorus catalyst having a molecular weight of 700 g / mol or more.

4. A composition for injection molding material in the first paragraph, wherein the mixing ratio of the imidazole catalyst and the phosphorus catalyst is 2:8 to 8:2 by weight.

5. A composition for injection molding material according to claim 1, wherein the catalyst comprises 2-phenyl-4-methyl-5-hydroxymethylimidazole and tetraphenylphosphonium, tetrahydroxy dinaphthalene.

6. In paragraph 1, A composition for injection molding, comprising 0.5 to 15 wt% of the epoxy resin, 2 to 20 wt% of the curing agent, 50 to 90 wt% of the filler, and 0.1 to 6 wt% of the catalyst, based on the total weight of the composition for molding.

7. A vehicle part molded using a composition for injection molding according to any one of claims 1 to 6.

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