JP2019157052A - Epoxy resin, epoxy resin composition and epoxy resin cured product, and semiconductor device, electric wire and rotating machine coil comprising epoxy resin cured product - Google Patents

Abstract

To provide an epoxy resin cured product in which an epoxy resin that does not accompany an increase in melting temperature or crystallization is used, has a glass transition temperature that represents heat resistance, is higher than ever, and is excellent in electrical insulation property.SOLUTION: An epoxy resin having a structure in which at least two glycidyl ether groups are bonded to a structure in which amidated phenolphthalein skeleton is dimerized is used. A desired epoxy resin cured product is obtained by the curing reaction of an epoxy resin composition containing said epoxy resin and a curing agent.SELECTED DRAWING: None

Description

  The present invention relates to an epoxy resin, an epoxy resin composition, an epoxy resin cured product, a semiconductor device including the epoxy resin cured product, an electric wire, and a rotating machine coil.

  A cured epoxy resin obtained from a mixture of an epoxy resin, a curing agent, a catalyst, a filler, and the like is excellent in various properties such as heat resistance, dimensional stability, moisture resistance, mechanical properties, and electrical insulation. Epoxy resins and epoxy resin cured products are used in a wide range of fields such as adhesives, paints, fiber reinforced composite materials, and the like from the field of electronic components such as semiconductor sealing materials and printed wiring board substrates.

  In recent years, the operating environment of inverters, motors, generators, and the like used in electric vehicles, hybrid vehicles, and the like that have a low environmental load and a high effect of improving fuel efficiency has become high temperature and high voltage. For this reason, the epoxy resin hardened | cured material which has higher heat resistance is requested | required for resin used for the sealing material of a power semiconductor device, or the conducting wire insulation material of a motor.

  Examples of the epoxy resin include novolac type epoxy resin, phenol aralkyl type epoxy resin, biphenyl type epoxy resin, monoglycidyloxybenzene type epoxy resin, and the like. These epoxy resins become a cured resin having high heat resistance by a curing reaction with a phenol compound, an amine compound or an acid anhydride.

  Patent Document 1 describes (A) an epoxy resin containing components represented by the following general formulas (1) and (2) as structural units in the main chain skeleton, (B) a curing agent, (C) a curing accelerator, (D) An epoxy resin molding material for sealing containing an inorganic filler as an essential component is described.

  Patent Document 2 describes a phenol aralkyl type epoxy resin having a structure in which at least glycidoxybenzenes or glycidoxynaphthalenes are bonded using an aralkyl group as a bonding group. The said literature describes that the said phenol aralkyl type epoxy resin may be an epoxy resin obtained by reaction of the phenol aralkyl resin of the structure shown to following formula (3), (4), and (5) and epihalohydrin. To do.

  Patent Document 3 describes an epoxy resin composition containing an epoxy resin having a molecular structure in which a monoglycidyloxybenzene structural moiety is bonded to an alkoxynaphthalene structural moiety via a methylene group.

  Patent Document 4 discloses a compound represented by the following formula (6) as an epoxy resin mixture having a low viscosity and a cured product having excellent heat resistance, water absorption characteristics, and flame retardancy. G and R each independently exist, G represents a glycidyl group, R represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms), and biphenol Those containing an epoxidized product are described.

JP 2001-11158 A JP 2007-191877 A JP 2008-195849 A International Publication No. 15/037584

  As described in Patent Documents 1 to 4, cured epoxy resins having various basic skeletons have been developed. However, in view of the usage environment of the cured resin having a high temperature and a high electric field, the conventional cured epoxy resin has a need to improve performance in terms of heat resistance and electrical insulation. In addition, an epoxy resin having a high heat-resistant skeleton needs to be mixed with another low melting point epoxy resin in order to avoid an increase in melting temperature and crystallization.

  Further, the heat resistance of the cured product of such an epoxy resin composition is higher than that of a general epoxy resin, but the glass transition temperature Tg measured by a thermodynamic viscoelasticity measuring device (DMA) is 180 ° C. at the maximum. I stayed at.

  An object of the present invention is to produce an epoxy resin cured product that has an unprecedented high glass transition temperature that exhibits heat resistance and excellent electrical insulation, using an epoxy resin that does not increase in melting temperature or crystallize. It is in.

  The epoxy resin of the present invention has a structure in which at least two glycidyl ether groups are bonded to a structure in which an amidated phenolphthalein skeleton is dimerized.

  The cured epoxy resin of the present invention is obtained by curing reaction of an epoxy resin composition containing the epoxy resin and a curing agent.

  According to the present invention, a cured epoxy resin product having a glass transition temperature exhibiting heat resistance reaches 192 ° C. and excellent in electrical insulation can be produced. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

2 is a graph showing a nuclear magnetic resonance spectrum of the epoxy resin of Example 1. FIG. It is sectional drawing which shows one Embodiment of the semiconductor device produced using the epoxy resin composition of this invention. It is sectional drawing which shows one Embodiment of the electric wire produced using the epoxy resin composition of this invention. It is sectional drawing which shows one Embodiment of the rotary machine coil produced using the epoxy resin composition of this invention.

  The epoxy resin of the present invention has a structure in which the amidated phenolphthalein skeleton is dimerized. The cured epoxy resin of the present invention has a structure in which the amidated phenolphthalein skeleton is dimerized as a basic skeleton. The cured epoxy resin of the present invention can be obtained by curing reaction of the epoxy resin of the present invention.

  The present inventor synthesized a compound in which the amidated phenolphthalein skeleton was dimerized by using an acid dianhydride having an asymmetric structure as a starting material. Subsequently, a novel epoxy resin was synthesized by epoxidizing this compound.

  Even if this epoxy resin was not mixed with other epoxy resins, the melting temperature measured with a calorimeter (DSC: Differential Scanning Calibration) was as low as 109 ° C. Moreover, when the cured product of this epoxy resin was cured using phenol novolac as a curing agent, the glass transition temperature Tg measured by a thermodynamic viscoelasticity measuring device (DMA) showed 192 ° C.

  Hereinafter, preferred embodiments of the present invention will be described in detail. Hereinafter, the present embodiment will be described as appropriate with reference to the drawings. The following description shows specific examples of the contents of the present invention. The present invention is not limited to the following description, and various changes and modifications can be made by those skilled in the art within the scope of the technical idea disclosed in the present specification. In all the drawings for explaining the present invention, the same reference numerals are given to those having the same function, and the repeated description thereof may be omitted.

<1. Epoxy resin>
The present invention relates to an epoxy resin. The epoxy resin of the present invention needs to have a structure in which the amidated phenolphthalein skeleton is dimerized. By curing reaction of the epoxy resin of the present invention, the cured epoxy resin of the present invention described below can be obtained.

  The present inventor found that an epoxy resin having a structure in which an amidated phenolphthalein skeleton is dimerized has higher heat resistance than a conventional epoxy resin having a structure in which an aromatic ring and another aromatic ring are mediated by a methylene group. It was found to have Further, the present inventors have found that this epoxy resin has a lower melting point than an epoxy resin containing a conventional monomeric amidated phenolphthalein structure. The reason why the epoxy resin (epoxy compound) of the present invention has the above-described characteristics can be explained as follows. Note that the present invention is not limited to the following actions and principles.

  Conventional epoxy compounds are synthesized, for example, by reaction of a polymerization product of a phenol compound and formaldehyde with epichlorohydrin. The epoxy resin cured product formed of such an epoxy compound may be improved in heat resistance by polyfunctionalizing and / or increasing the molecular weight of the polymerization product. However, since conventional epoxy compounds have a structure in which an aromatic ring and another aromatic ring are bonded via a methylene group, the degree of freedom of molecular motion is high, and the resulting cured epoxy resin has a high degree of freedom. There was a limit to heat resistance.

  On the other hand, since the epoxy compound of the present invention has a structure in which the amidated phenolphthalein skeleton is dimerized, the degree of freedom of molecular motion is limited. For this reason, the cured epoxy resin obtained by curing the epoxy compound of the present invention has a high glass transition temperature. Therefore, the epoxy compound of the present invention having a structure in which the amidated phenolphthalein skeleton is dimerized is compared with a conventional epoxy compound having a structure in which an aromatic ring and another aromatic ring are bonded via a methylene group. Thus, an epoxy resin cured product having high heat resistance can be formed.

  The epoxy compound and the cured epoxy resin of the present invention have a structure in which the amidated phenolphthalein skeleton is dimerized. For example, the nuclear magnetic resonance spectrum (NMR spectrum) of the epoxy compound and the cured epoxy resin is obtained. This can be confirmed by measuring. The glass transition temperature of the cured epoxy resin of the present invention can be determined by, for example, a thermodynamic viscoelasticity measuring device (DMA).

  As described above, the cured epoxy resin formed by the epoxy compound of the present invention has high heat resistance due to the dimerized structure of the amidated phenolphthalein skeleton. For this reason, the epoxy compound of this invention can form the epoxy resin hardened | cured material which has high heat resistance, without making the epoxy group density | concentration in a molecule | numerator high by having said structure.

  Usually, in an epoxy compound, when the concentration of epoxy groups in the molecule is high, the concentration of hydroxyl groups in the molecule generated by the curing reaction is high. In this case, there is a possibility that the water absorption amount of the cured epoxy resin formed is increased.

  In contrast, the epoxy compound of the present invention has a low epoxy group concentration in the molecule and a high epoxy equivalent. Specifically, the epoxy equivalent of the epoxy compound of the present invention is usually in the range of 246 to 300 g / eq, typically in the range of 250 to 280 g / eq, in particular, 253 to 268 g / eq. Range. Therefore, the cured epoxy resin formed by the epoxy compound of the present invention can have a low water absorption and dielectric constant. Thereby, the epoxy resin hardened | cured material of this invention can become a resin material excellent in the electrical insulation which has high dielectric breakdown strength.

  The epoxy group concentration or the number of glycidyl ether groups introduced in the epoxy compound of the present invention can be determined, for example, by performing elemental analysis or mass spectrometry of the epoxy compound. Moreover, the epoxy equivalent of the epoxy compound of this invention can be determined by the method prescribed | regulated to JISK7236, for example.

  The epoxy resin of the present invention is a compound represented by the following formula (7).

  In the above formula (7), G is a glycidyl ether group, and R is hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. Each G may have the same structure or a different structure. Each R may have the same structure or a different structure.

  A compound having a structure in which phenolphthalein is dimerized by reacting 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride (a-BPDA), which is an asymmetric acid dianhydride, with phenol (P— BPDA). This is reacted with an amine for amidation. The epoxy resin of the present invention can be produced by epoxidizing the amidation product (NP-BPDA). The epoxidation reaction can be performed, for example, by reacting a compound having a structure in which an epihalohydrin and an amidated phenolphthalein skeleton are dimerized. The reaction material used for the reaction and the reaction conditions for each reaction can be appropriately selected based on the structure of the epoxy compound of the present invention.

<2. Epoxy resin composition>
The epoxy compound of the present invention can form an epoxy resin cured product by curing reaction with a curing agent. Therefore, the present invention also relates to an epoxy resin composition comprising the epoxy compound of the present invention. The epoxy resin composition of the present invention needs to contain the epoxy compound of the present invention and at least one curing agent.

  The at least one curing agent contained in the epoxy resin composition of the present invention is usually a compound having a hydroxyl group. The curing agent is preferably a phenolic curing agent having a hydroxyl group, and more preferably a phenolic curing agent having two or more hydroxyl groups in the molecule. Examples of the curing agent include, but are not limited to, for example, resol type phenol resins such as aniline-modified resole resin or dimethyl ether resole resin; Type phenol resin; and phenol compounds such as phenol aralkyl resin, 2,2′-biphenol, resorcinol, and the like. The said hardening | curing agent may use only 1 type and may be used with the form of a 2 or more types of mixture. The epoxy resin composition of the present invention containing the curing agent is allowed to undergo a curing reaction under predetermined conditions, whereby the glycidyl ether group of the epoxy compound of the present invention and the curing agent undergo a crosslinking reaction, thereby having an epoxy crosslinking group. A cured resin product can be formed.

  The epoxy resin composition of the present invention may optionally include at least one curing accelerator.

  Examples of the curing accelerator include, but are not limited to, tertiary amines such as triethanolamine, tetramethylbutanediamine, tetramethylpentanediamine, tetramethylhexanediamine, triethylenediamine, or methylaniline; dimethylaminoethanol or Mention may be made of oxyalkylamines such as dimethylaminopentanol; and amines such as tris (dimethylaminomethyl) phenol or methylmorpholine.

  Examples of the curing accelerator include, but are not limited to, 2-undecylimidazole, 2-methylimidazole, 2-ethylimidazole, 2-heptadecylimidazole, 2-methyl-4-ethylimidazole, 1 -Butylimidazole, 1-propyl-2-methylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole or Imidazole compounds such as 1-azine-2-undecylimidazole, etc .; tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, 2-ethyl-4-methylimidazolium tetraphenyl volley Or tetraphenylboron salts such as 2-ethyl-1,4-dimethylimidazolium tetraphenylborate, triphenylphosphine triphenylborane, triethylamine triphenylborane, triphenylphosphine, diazabicycloundecene, diazabicyclononene, and An acid anhydride etc. can also be mentioned.

  The said hardening accelerator may use only 1 type and may be used with the form of 2 or more types of mixtures. By containing the curing accelerator, the curing reaction of the epoxy resin composition of the present invention can be accelerated.

  The epoxy resin composition of the present invention may optionally contain at least one filler. The filler can be appropriately selected based on desired characteristics. Examples of the filler include, but are not limited to, silica powder such as fused silica, talc, aluminum powder, mica, clay, and calcium carbonate. An epoxy resin cured product having desired characteristics can be obtained by curing reaction of the epoxy resin composition of the present invention containing the at least one filler under predetermined conditions.

  The epoxy resin composition of the present invention may optionally contain at least one additive. Examples of the additive include, but are not limited to, release agents such as natural waxes, synthetic waxes, linear aliphatic metal oxides, acid amides, esters, paraffins; carbon black or bengara Coloring agents such as: various coupling agents; metal hydroxides such as aluminum hydroxide or magnesium hydroxide. An epoxy resin cured product having desired characteristics can be obtained by curing reaction of the epoxy resin composition of the present invention containing the at least one additive under predetermined conditions.

<3. Cured epoxy resin>
In the cured epoxy resin of the present invention, the ether crosslinking group is a group formed from a glycidyl ether group of the epoxy compound of the present invention contained in the epoxy resin composition of the present invention. The ether crosslinking group is formed, for example, by the ring opening reaction of the hydroxyl group of the curing agent contained in the epoxy resin composition of the present invention with the glycidyl ether group of the epoxy compound of the present invention, or by the ring opening reaction. The hydroxyl group derived from the glycidyl ether group to be formed is formed by further ring-opening reaction with another glycidyl ether group.

  By having the basic skeleton, the cured epoxy resin of the present invention can have high heat resistance and excellent electrical insulation.

  As already explained, the cured epoxy resin of the present invention has a high glass transition temperature. Specifically, the cured epoxy resin of the present invention usually has a high glass transition temperature of 150 ° C. or higher, typically in the range of 150 to 450 ° C., particularly in the range of 170 to 350 ° C. By having a glass transition temperature in the above range, the cured epoxy resin of the present invention can have high heat resistance.

  In addition, the glass transition temperature of the epoxy resin hardened | cured material of this invention can be determined with a thermodynamic viscoelasticity measuring apparatus (DMA), for example.

  As already explained, the cured epoxy resin of the present invention has a low dielectric constant. Specifically, the cured epoxy resin of the present invention usually has a relative dielectric constant of 3.5 or less, typically 2.0 to 3.5. By having a low relative dielectric constant in the above range, the cured epoxy resin of the present invention can be a resin material having high dielectric breakdown strength and excellent electrical insulation. The relative dielectric constant of the cured epoxy resin of the present invention can be determined as a value at 10 GHz by, for example, a cavity resonance perturbation method.

  The cured epoxy resin of the present invention can be obtained by curing reaction of the epoxy resin composition of the present invention. The temperature of the curing reaction is preferably in the range of 100 to 250 ° C, more preferably in the range of 130 to 230 ° C. The time for the curing reaction is preferably in the range of 0.5 to 16 hours, and more preferably in the range of 1 to 6 hours. By carrying out the curing reaction under the above conditions, the cured epoxy resin of the present invention can be obtained.

<4. Uses of cured epoxy resin>
The cured epoxy resin of the present invention can be used as a sealing material for electrical devices and semiconductor devices. Therefore, the present invention also relates to a semiconductor device having a semiconductor element and a sealing member that seals the semiconductor element and includes the cured epoxy resin of the present invention.

  In the present invention, “semiconductor device” means any semiconductor device known in the art. Examples of the semiconductor device of the present invention include, but are not limited to, for example, a television receiver, a mobile phone, a device built in an electronic device such as a computer or an electronic device, or a computer or the like in an automobile or various industrial devices. Can be cited as an example.

  In the present invention, the “semiconductor element” means an electronic component itself composed of a semiconductor or an element at the functional center of the electronic component. Examples of the semiconductor element include, but are not limited to, a transistor, an integrated circuit (IC or LSI), a resistor, and a capacitor.

  In the present invention, the “sealing member” is one of members constituting the semiconductor device and means a member used for preventing air oxidation of the semiconductor element and / or contamination of the semiconductor element.

  FIG. 2 shows a cross-sectional view of a power semiconductor device which is an embodiment of the semiconductor device of the present invention.

  As shown in the figure, in the power semiconductor device 2 of the present invention, the lower surface side electrode of the power semiconductor element 204 is electrically connected to the heat radiating plate 206 through a bonding material 205. The main electrode of the power semiconductor element 204 is electrically connected to the lead member 203 via the wire 202. The periphery of the power semiconductor element 204 is sealed with the sealing member 201 in a state where the heat radiating plate 206 and the lead member 203 are partially exposed. The sealing member 201 includes the cured epoxy resin of the present invention.

  The cured epoxy resin of the present invention has high dielectric breakdown strength. For this reason, in the power semiconductor device of this invention which uses the epoxy resin hardened | cured material of this invention as a sealing member, the short circuit with a power semiconductor element and wiring by partial discharge can be prevented. Therefore, by using the cured epoxy resin of the present invention as a sealing member, it can contribute to the extension of the life of the power semiconductor device of the present invention.

  The structure of the power semiconductor device shown in FIG. 2 is an example showing an embodiment of the semiconductor device of the present invention. Even in a semiconductor device having another structure, similar effects can be obtained by using the cured epoxy resin of the present invention as a sealing member.

  The cured epoxy resin of the present invention can also be used as an insulating material for covering a conductor. Therefore, the present invention also relates to an electric wire having a conductor and an insulating member covering the conductor and containing the cured epoxy resin of the present invention.

  In the present invention, the “electric wire” includes a linear conductor such as a metal used to conduct electricity between two points, and a coating member for insulation and / or protection is provided on the surface thereof. It means what you have. Examples of the electric wires include, but are not limited to, high-voltage distribution wires, high-voltage lead-in wires, low-voltage overhead wires, low-voltage lead-in wires, or indoor wires, etc .; electric wires for electric equipment, communication wires, underground wires Cables for indoor wiring, fire fighting equipment, control circuit, power equipment, marine or undercarpet wiring; and cords used by connecting to outlets of small electrical products Can be mentioned. The shape of the said electric wire is not specifically limited, The electric wire of various shapes normally used in the said technical field, such as a single wire, a twisted wire, a twisted pair wire, or a shield wire, can be included.

  In the present invention, the “conductor” means a material having a high electrical conductivity (conductivity) having a property of containing a movable charge and easily conducting electricity. Examples of the conductor include, but are not limited to, copper, silver, aluminum, alloys thereof, and optical fibers.

  In the electric wire of the present invention, the insulating member includes the cured epoxy resin of the present invention as an insulating material. The insulating member has a property that it is difficult to conduct electricity and / or heat, such as polyethylene, cross-linked polyethylene, polyvinyl chloride, kapton, rubber-like polymer, oil-impregnated paper, Teflon (registered trademark), silicone, or fluororesin, if desired. One or more additional materials may be included.

  FIG. 3 shows a cross-sectional view of an insulated wire which is an embodiment of the wire of the present invention.

  As shown in the figure, the insulated wire 3 of the present invention has a conductor 301 and an insulating member 302 covering the conductor 301. The insulating member 302 includes the cured epoxy resin of the present invention. The insulated wire 3 can be produced, for example, by applying the epoxy resin composition of the present invention to the conductor 301 and then heat-curing it. Thereby, the insulating member 302 containing the cured epoxy resin of the present invention covering the conductor 301 is formed.

  The cured epoxy resin of the present invention has high dielectric breakdown strength. For this reason, the insulated electric wire which is excellent in surge-proof characteristics can be obtained by using the epoxy resin hardened | cured material of this invention as an insulating material.

  In addition, the structure of the insulated wire shown in FIG. 3 is an example which shows one Embodiment of the electric wire of this invention. In the electric wires having other structures, similar effects can be obtained by using the cured epoxy resin of the present invention as an insulating material.

  The cured epoxy resin of the present invention can also be used as an insulating material for an insulating member in which a conductor is wound in a rotating machine coil. Therefore, the present invention also relates to a rotating machine coil having a conductor, an insulating member wound around the conductor, and an impregnated resin member impregnated in the insulating member and containing the cured epoxy resin of the present invention. .

  In the present invention, the “rotary machine coil” means a conductor in which an insulation coating is wound in a coil shape. The rotating machine coil of the present invention can be used as a constituent member of a motor or a generator by combining with a magnet.

  FIG. 4 shows a perspective view of one embodiment of the rotating machine coil of the present invention.

  As shown in this figure, the rotating machine coil 4 of the present invention has a conductor 401, an insulating member wound around the conductor 401, and an impregnated resin member 402 impregnated in the insulating member. The impregnated resin member 402 includes the cured epoxy resin of the present invention. The impregnated resin member 402 is usually formed by impregnating an insulating member with the cured epoxy resin of the present invention. In the rotating machine coil 4 of the present invention, for example, an insulating member such as an insulating tape is wound around the conductor 401, and after heating and drying, the insulating member is impregnated with the epoxy resin composition of the present invention under a vacuum, for example, It can produce by heat-hardening. Thereby, the impregnation resin member 402 containing the cured epoxy resin of the present invention is formed.

  The cured epoxy resin of the present invention has high dielectric breakdown strength. For this reason, the rotating machine coil which is excellent in heat-resistant lifetime can be obtained by using the epoxy resin hardened | cured material of this invention as an insulating material of the insulating member which has wound the conductor.

  In addition, the structure of the rotating machine coil shown in FIG. 4 is an example which shows one Embodiment of the rotating machine coil of this invention. Even in a rotating machine coil having another structure, similar effects can be obtained by using the cured epoxy resin of the present invention as an insulating material.

  The breakdown strength of the cured epoxy resin of the present invention is, for example, a rate of decrease of the breakdown voltage in a predetermined time in an electrical device and a semiconductor device using the cured epoxy resin of the present invention by an accelerated life evaluation test at 150 ° C. Can be evaluated.

  In a 100 mL three-necked flask, 10.0 g (34.0 mmol) of a-BPDA and 16.9 g of phenol (170 mmol, 2.5 equivalents with respect to the carbonyl group) were put, and after being placed in an argon atmosphere, 24.8 mL of methanesulfonic acid. (382 mmol) was added and stirred at 90 ° C. for 48 hours. After cooling to room temperature, it was added dropwise to 20 times the amount of ice-cold ion-exchanged water and stirred for 12 hours. The generated solid was collected by suction filtration, washed with water, and dried under reduced pressure at 60 ° C. overnight to obtain P-BPDA, a compound obtained by phenolizing a-BPDA, as a reddish brown solid. The yield was 18.4 g (yield: 85%).

  Subsequently, 15.0 g (23.5 mmol) of P-BPDA and 339 mL (3.61 mol) of 40% methylamine aqueous solution were added to a glass bottle with a 1000 mL lid, and the lid was capped and stirred at room temperature for 21 days. During this time, the color of the solution changed from dark purple to reddish purple. The solution after the reaction was added dropwise to “ice-cooled ion-exchange water (20 times the amount of the reaction solution) mixed with 383 mL (4.6 mol) of 12 mol / L hydrochloric acid”, and then the produced solid was collected by suction filtration. The solid was washed with water and dried under reduced pressure at 60 ° C. overnight to obtain a light blue solid. This solid was dissolved again in methanol (160 mL), and then re-precipitated by adding dropwise to 20 times the amount of ion-exchanged water. The obtained solid was collected by suction filtration, washed with water, and dried under reduced pressure at 60 ° C. overnight to obtain an amidated product NP-BPDA as a pale blue solid. The yield was 15.1 g (yield: 97%).

  Next, 10.0 g (15.1 mmol) of N-PBPDA, 84.9 g (0.918 mol) of epichlorohydrin, 1.26 g of tetramethylammonium chloride, ion-exchanged water (Pasteur pipette) in a 300 mL three-necked flask And then stirred at 80 ° C. for 8 hours under an argon stream (stirring speed: 250 rpm). Thereafter, the argon stream was stopped while stirring was continued, and after cooling to 40 ° C., 45.9 g of a 20 mass% NaOH aqueous solution was added dropwise and reacted at 40 ° C. for 15 hours.

  After the reaction solution was cooled to room temperature, it was neutralized by dropwise addition of 55.2 g of a 20% by mass aqueous acetic acid solution, and extracted with methylene chloride. The organic layer after extraction was washed three times with an aqueous sodium chloride solution, then concentrated by an evaporator, and the concentrated solution was dropped into 20 times the amount of hexane. The produced solid was collected by suction filtration and then poured into THF (without stabilizer), and the THF soluble part was collected by suction filtration. The solvent THF was distilled off under reduced pressure using an evaporator and then dried under reduced pressure at 60 ° C. overnight to obtain an epoxy resin (E-NP-PBPDA) of the present invention as a light orange solid. The yield was 12.8 g (yield: 96%).

FIG. 1 shows the ¹ H-NMR spectrum of E-NP-PBPDA (solvent: deuterated dimethyl sulfoxide, measurement temperature: room temperature).

  Moreover, when the epoxy equivalent of E-NP-PBPDA was calculated | required by the hydrochloric acid-dioxane method, it was 259 g / eq. It was 109 degreeC as a result of measuring the softening point of E-NP-PBPDA by TMA.

  The obtained epoxy resin and phenol resin (Phenolite TD-2131, DIC) were blended and mixed so that the molar ratio of glycidyl ether group and hydroxyl group was 1: 1.1. By adding tetraphenylphosphonium tetra-p-tolylborate (TPP-MK, Hokuko Chemical) as a curing catalyst to 1 part by mass with respect to 100 parts by mass of the obtained mixture, the resin was mixed at 130 ° C. A composition was obtained. The obtained resin composition was cured by heating in this order at 130 ° C. for 2 hours, 160 ° C. for 3 hours, 180 ° C. for 3 hours, 200 ° C. for 5 hours, and 230 ° C. for 3 hours. A cured product was obtained.

  The glass transition temperature of the cured resin determined by a thermodynamic viscoelasticity measuring apparatus (DMA) is 192 ° C., and the relative dielectric constant of the cured resin at 10 GHz determined by the cavity resonance perturbation method is 3.4. Met.

(Comparative Example 1)
As a comparative example, an ortho cresol novolak type epoxy compound (211 g / eq, YDCN-750, Toto Kasei) having a structure bonded via a methylene group was used. The ortho-cresol novolac type epoxy compound (YDCN-750) and the phenol resin phenolite TD-2131 were blended and mixed so that the molar ratio of glycidyl ether group and hydroxyl group was 1: 1.1. By adding tetraphenylphosphonium tetra-p-tolylborate (TPP-MK, Hokuko Chemical)) as a curing catalyst to 100 parts by mass of the obtained mixture, and mixing at 150 ° C. A resin composition was obtained. The obtained resin composition was heat-cured at 180 ° C. for 6 hours to obtain a cured resin.

  The glass transition temperature of the cured resin determined by a thermodynamic viscoelasticity measuring apparatus (DMA) is 170 ° C., and the relative dielectric constant of the cured resin at 10 GHz determined by the cavity resonance perturbation method is 3.8. Met.

  The epoxy compound used in Comparative Example 1 has a structure in which ortho-cresol is bonded via a methylene group.

  On the other hand, since the epoxy compound of Example 1 has a structure in which the amidated phenolphthalein skeleton is dimerized, the degree of freedom of molecular motion is limited. For this reason, the cured epoxy resin obtained by curing the epoxy compound of the present invention has a high glass transition temperature.

  The epoxy equivalent of Example 1 was 259 g / eq, which was higher than that of the ortho-cresol novolak epoxy compound of Comparative Example 1. In general, the higher the epoxy equivalent of the epoxy compound, the lower the concentration of the epoxy group that becomes the reaction point, and as a result, the concentration of the hydroxyl group generated by the curing reaction decreases. For this reason, when the epoxy compound of Example 1 was used, compared with the case where the comparative example 1 was used, it is thought that the resin hardened | cured material with a low dielectric constant was able to be obtained.

  From the comparison between Example 1 and Comparative Example 1, since the epoxy compound of the present invention has a structure in which the amidated phenolphthalein skeleton is dimerized, it gives a cured resin having high heat resistance and excellent electrical insulation. It was shown that.

  A power semiconductor device was manufactured using the epoxy resin composition of the present invention.

  The epoxy compound of Example 1 and a phenol resin (Phenolite TD-2131) were blended and mixed so that the molar ratio of glycidyl ether group and hydroxyl group was 1: 1.1. To 100 parts by mass of the obtained mixture, 1 part by mass of tetraphenylphosphonium tetra-p-tolylborate (TPP-MK, Hokuko Chemical) was added as a curing catalyst. 400 parts by mass of silica as a filler, 5 parts by mass of KBM403 (manufactured by Shin-Etsu Chemical Co., Ltd.) as a silane coupling agent, 2 parts by mass of Hoechst wax E (manufactured by Clariant Japan Co., Ltd.) as a release agent, and as a colorant 1 part by mass of carbon black was added and melt kneaded to prepare a sealing resin raw material.

  A module having a power semiconductor element was produced according to a conventional method.

  Using the sealing resin raw material, the entire module was covered by a transfer mold method, and heat-cured at 180 ° C. for 6 hours to seal the resin.

(Comparative Example 2)
In Example 2, an ortho-cresol novolak type epoxy compound (211 g / eq, YDCN-750, Toto Kasei) having a structure bonded via a methylene group is used as the epoxy compound, as in Example 2. Thus, a power semiconductor device was manufactured.

  And about the power semiconductor device of Example 2 and Comparative Example 2, the power cycle life was evaluated by the power cycle (PC) test. Here, the power cycle test is a cycle in which a constant current is supplied to the power semiconductor device for 5 seconds to generate heat and the junction temperature of the power semiconductor element is increased from 20 ° C. to 190 ° C. and then cooled to 20 ° C. The number of cycles in which the junction temperature of the power semiconductor element when the current was constant increased to 200 ° C. or higher was defined as the power cycle life.

  As a result, the power cycle life of the power semiconductor device of Example 2 was 25,000 times, whereas the power cycle life of the power semiconductor device of Comparative Example 2 was 4000 times.

  From this test result, it is shown that a power semiconductor device manufactured using the cured resin product of the present invention has an improved power cycle life compared to a power semiconductor device manufactured using a conventional cured resin product. It was done. This result is considered to be because the deterioration of insulation associated with the partial discharge voltage is suppressed by using the cured epoxy resin of the present invention as the sealing member.

  An enameled wire was prepared using the epoxy resin composition of the present invention. The epoxy resin composition of the present invention was prepared by the same procedure as in Example 1. After the obtained epoxy resin composition was applied to an electric wire, it was cured by heating at 180 ° C. for 6 hours to obtain an enameled wire coated with the cured epoxy resin of the present invention.

  The performance of the obtained enamel wire was evaluated by an accelerated life evaluation test at 150 ° C. As a result, the reduction rate of the dielectric breakdown voltage for 500 hours of the enameled wire of Example 3 was 5% of the initial value.

(Comparative Example 3)
An enameled wire of Comparative Example 3 was prepared using bisphenol A type epoxy resin and acid anhydride (MHACP: methyl-3,6 endomethylene-1,2,3,6-tetrahydrophthalic anhydride). Here, the equivalence ratio of the epoxy group and the acid anhydride was mixed so as to be 1: 0.9. 2% of 2-ethyl-methylimidazole was mix | blended with respect to this resin mixture, and it was set as the epoxy resin composition. This epoxy resin composition was applied to an electric wire and heat-cured at 180 ° C. for 6 hours to obtain an enameled wire. The performance of the obtained enamel wire was evaluated by an accelerated life evaluation test at 150 ° C.

  As a result, the reduction rate of the dielectric breakdown voltage for 500 hours of the enameled wire of Comparative Example 3 was 60% of the initial value.

  From this test result, it was shown that the enameled wire produced using the resin cured product of the present invention is superior in voltage resistance compared to the enameled wire produced using a conventional insulating coating material.

  A rotating machine coil was prepared using the epoxy resin composition of the present invention. The epoxy resin composition of the present invention was prepared by the same procedure as in Example 1. An insulating tape was wound around the conductor and dried by heating. The obtained epoxy resin composition was vacuum impregnated and then heat-cured at 180 ° C. for 6 hours to obtain a rotating machine coil having an impregnated resin member containing the cured epoxy resin of the present invention.

  The performance of the obtained rotating machine coil was evaluated by an accelerated life evaluation test at 150 ° C. As a result, the reduction rate of the dielectric breakdown voltage of the enameled wire of Example 5 for 500 hours was 8% of the initial value.

(Comparative Example 4)
A rotating machine coil of Comparative Example 4 was produced using bisphenol A type epoxy resin and acid anhydride (MHACP: methyl-3,6 endomethylene-1,2,3,6-tetrahydrophthalic anhydride). Here, the equivalence ratio of the epoxy group and the acid anhydride was mixed so as to be 1: 0.9. 2% of 2-ethyl-methylimidazole was mix | blended with respect to this resin mixture, and it was set as the epoxy resin composition. An insulating tape was wound around the conductor and dried by heating. The obtained epoxy resin composition was vacuum impregnated and then heated and cured at 180 ° C. for 6 hours to obtain a rotating machine coil having an impregnated resin member containing a cured epoxy resin.

  The performance of the obtained rotating machine coil was evaluated by an accelerated life evaluation test at 150 ° C. As a result, the reduction rate of the dielectric breakdown voltage for 500 hours of the rotating machine coil of Comparative Example 4 was 60% of the initial value.

  From this test result, it is shown that the rotating machine coil produced using the resin cured product of the present invention is superior in voltage resistance compared to the rotating machine coil produced using a conventional insulating coating material. It was.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, it is possible to add, delete, and / or replace another configuration with respect to a part of the configuration of each embodiment.

  2: power semiconductor device, 3: insulated wire, 4: rotating machine coil, 201: sealing member, 202: wire, 203: lead member, 204: power semiconductor element, 205: bonding material, 206: heat sink, 301: Conductor, 302: insulating member, 401: conductor, 402: impregnated resin member.

Claims (9)

  An epoxy resin having a structure in which at least two glycidyl ether groups are bonded to a structure obtained by dimerizing an amidated phenolphthalein skeleton. An epoxy resin having a structure represented by the following formula (7).
(In the formula, G is a glycidyl ether group, and R is hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. Each G has the same structure. Or each R may have the same structure or a different structure.)

  The epoxy resin of Claim 1 or 2 whose epoxy equivalent is 246-300 g / eq.   An epoxy resin composition comprising the epoxy resin according to any one of claims 1 to 3 and at least one curing agent.   A cured epoxy resin obtained by curing the epoxy resin composition according to claim 4.   An epoxy resin cured product having a structure obtained by dimerizing an amidated phenolphthalein skeleton as a basic skeleton. A semiconductor element, and a sealing member that seals the semiconductor element,
The said sealing member is a semiconductor device containing the epoxy resin hardened | cured material of Claim 5 or 6. A conductor and an insulating member covering the conductor;
The said insulation member is an electric wire containing the epoxy resin hardened | cured material of Claim 5 or 6. A conductor, an insulating member wound around the conductor, and an impregnated resin member impregnated in the insulating member;
The said impregnation resin member is a rotating machine coil containing the epoxy resin hardened | cured material of Claim 5 or 6.

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