Molded stator and motor

Abstract

A molded stator according to the present invention includes: a stator having a stator core and a coil wound around the stator core; and a molding material covering the stator. The molding material is the cured product of a thermosetting resin composition containing: a saturated polyester resin (A), a thermosetting resin (B), an ethylenically unsaturated monomer (C), a thermal polymerization initiator (D), glass fibers (E), an inorganic filler (F), and a thickener (G). The thickener (G) is at least one selected from the group consisting of styrene-butadiene rubber (SBR), styrene-butadiene-styrene rubber (SBS), and styrene-ethylene-butadiene-styrene rubber (SEBS). The thickener (G) content in the thermosetting resin composition is 0.8 to 9 parts by mass with respect to 100 parts by mass, which is the total amount of the thermosetting resin (B) and the ethylenically unsaturated monomer (C). The saturated polyester resin (A) is a polycondensate of a diol and a saturated polybasic acid. The saturated polybasic acid contains an aromatic saturated polybasic acid or an acid anhydride thereof, and an aliphatic saturated polybasic acid. In the saturated polyester resin (A), the content ratio (molar ratio) of the structure derived from the aromatic saturated polybasic acid or the acid anhydride thereof to the structure derived from the aliphatic saturated polybasic acid is 20:80 to 80:20. The saturated polyester resin (A) includes a block (X) that is a polycondensate of a diol and an aromatic saturated polybasic acid or an acid anhydride thereof, and a block (Y) that is a polycondensate of a diol and an aliphatic saturated polybasic acid. The weight-average molecular weight of the block (X) is 3,000 to 5,000.

Description

Molded stators and motors

[0001] The present disclosure relates to a molded stator, a motor including the molded stator, and a thermosetting resin composition.

[0002] There is a growing demand for smaller, thinner, lighter, and more powerful motors and transformers for home appliances. Furthermore, due to the characteristics of the environment in which these appliances are used, they must be low-noise and low-vibration. To meet this demand, a structure has been proposed in which an electromagnetic coil wound around a stator core is covered with a molded resin (see Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2023-091064

[0004] When molding a stator so that it is covered with mold resin, the increasingly complex shape of the stator results in thin and thick sections in the hardened mold resin. Furthermore, the need to reduce the amount of mold resin to the utmost is becoming a necessity as thinner and lighter motors are made available. This has resulted in the mold resin not being strong enough as it hardens, causing cracks in the molded product. Furthermore, if the mold resin does not fill well, the resin does not fill the mold completely, resulting in chips in the molded product.

[0005] The present disclosure provides a molded stator covered with a molding material that has a good appearance without chips or cracks.

[0006] The present disclosure includes the following aspects: [1] A molded stator including a stator having a stator core and a coil wound around the stator core, and a molding material covering the stator, wherein the molding material is a cured product of a thermosetting resin composition containing (A) a saturated polyester resin, (B) a thermosetting resin, (C) an ethylenically unsaturated monomer, (D) a thermal polymerization initiator, (E) glass fiber, (F) an inorganic filler, and (G) a thickener, wherein the thickener (G) is one or more selected from the group consisting of styrene-butadiene rubber (SBR), styrene-butadiene-styrene rubber (SBS), and styrene-ethylene-butadiene-styrene rubber (SEBS), and the content of the thickener (G) in the thermosetting resin composition is 0.8 to 9 parts by mass, where the total amount of the thermosetting resin (B) and the ethylenically unsaturated monomer (C) is 100 parts by mass, [2] A molded stator according to [1], wherein the saturated polyester resin (A) is a polycondensate of a diol and a saturated polybasic acid, the saturated polybasic acid containing an aromatic saturated polybasic acid or its acid anhydride and an aliphatic saturated polybasic acid, the content ratio (molar ratio) of the structure derived from the aromatic saturated polybasic acid or its acid anhydride to the structure derived from the aliphatic saturated polybasic acid in the saturated polyester resin (A) is 20:80 to 80:20, the saturated polyester resin (A) contains a block (X) which is a polycondensate of a diol and an aromatic saturated polybasic acid or its acid anhydride, and a block (Y) which is a polycondensate of a diol and an aliphatic saturated polybasic acid, and the weight average molecular weight of the block (X) is 3,000 to 5,000. [3] The molded stator according to [1] or [2], wherein the aromatic saturated polybasic acid constituting the block (X) is one or more selected from isophthalic acid and terephthalic acid. [4] The molded stator according to any one of [1] to [3], wherein the aliphatic saturated polybasic acid constituting the block (Y) is one or more selected from succinic acid, adipic acid, and sebacic acid.[5] The molded stator according to any one of [1] to [4], wherein the weight average molecular weight of the thermosetting resin (B) is 10,000 to 50,000. [6] The molded stator according to any one of [1] to [5], wherein the thermosetting resin (B) contains an unsaturated polyester resin, the unsaturated polyester resin is a polycondensate of a diol, an unsaturated polybasic acid, and an optional saturated polybasic acid, and the diol contains propylene glycol and neopentyl glycol. [7] The molded stator according to any one of [1] to [6], wherein the thermosetting resin composition contains, where the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer is 100 parts by mass, 5 to 30 parts by mass of the (A) saturated polyester resin, 5 to 80 parts by mass of the (B) thermosetting resin, 20 to 95 parts by mass of the (C) ethylenically unsaturated monomer, 0.5 to 20 parts by mass of the (D) thermal polymerization initiator, 5 to 200 parts by mass of the (E) glass fiber, and 50 to 1000 parts by mass of the (F) inorganic filler. [8] A motor comprising: the molded stator according to any one of [1] to [7], a rotor having a rotating shaft extending in an axial direction, and a rotating body including a magnetic component extending in the axial direction and fixed to the rotating shaft, the rotor being positioned inside the stator, and a bearing rotatably supporting the rotor.[9] A composition comprising (A) a saturated polyester resin, (B) a thermosetting resin, (C) an ethylenically unsaturated monomer, (D) a thermal polymerization initiator, (E) glass fiber, (F) an inorganic filler, and (G) a thickener, wherein the (G) thickener is one or more selected from the group consisting of styrene-butadiene rubber (SBR), styrene-butadiene-styrene rubber (SBS), and styrene-ethylene-butadiene-styrene rubber (SEBS), and the content of the (G) thickener is 0.8 to 9 parts by mass, relative to 100 parts by mass of the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer, and the (A) saturated polyester resin is a polycondensate of a diol and a saturated polybasic acid, and the saturated polybasic acid comprises an aromatic saturated polybasic acid or an acid anhydride thereof, and an aliphatic saturated polybasic acid,

[10] A thermosetting resin composition according to [9], wherein the saturated polyester resin (A) has a weight average molecular weight of 9,500 to 13,500, and the saturated polyester resin (A) has a molar ratio of the structure derived from the saturated aromatic polybasic acid or its acid anhydride to the structure derived from the saturated aliphatic polybasic acid of 20:80 to 80:20. The saturated polyester resin (A) comprises a block (X) which is a polycondensate of a diol and a saturated aromatic polybasic acid or its acid anhydride, and a block (Y) which is a polycondensate of a diol and a saturated aliphatic polybasic acid, and the weight average molecular weight of the block (X) is 3,000 to 5,000.

[11] The thermosetting resin composition according to [9] or

[10] , comprising: 5 to 30 parts by mass of the (A) saturated polyester resin; 5 to 80 parts by mass of the (B) thermosetting resin; 20 to 95 parts by mass of the (C) ethylenically unsaturated monomer, 0.5 to 20 parts by mass of the (D) thermal polymerization initiator; 5 to 200 parts by mass of the (E) glass fiber; and 50 to 1,000 parts by mass of the (F) inorganic filler, where the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer is 100 parts by mass.

[12] A molding material that is a cured product of the thermosetting resin composition according to any one of [9] to

[11] .

[0007] According to the present disclosure, it is possible to provide a molded stator covered with a molding material that has a good appearance and is free from chips and cracks.

[0008] FIG. 1 is a cross-sectional schematic view of an exemplary motor.

[0009] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the embodiments described below.

[0010] In this specification, when "to" is used to describe a numerical range, the numerical values ​​at both ends are the upper and lower limits, respectively, and are included in the numerical range. When multiple upper or lower limits are listed, numerical ranges can be created using all combinations of the upper and lower limits. Similarly, when multiple numerical ranges are listed, separate numerical ranges can be created by individually selecting and combining the upper and lower limits from those numerical ranges.

[0011] In this specification, "(meth)acrylic acid" means methacrylic acid or acrylic acid, "(meth)acrylate" means acrylate or methacrylate, and "(meth)acryloyloxy" means acryloyloxy or methacryloyloxy.

[0012] In this specification, the term "thermosetting resin" refers to a resin that hardens by forming a crosslinked structure when heated, and indicates the resin in the pre-hardened state.

[0013] In this specification, the term "ethylenically unsaturated bond" means a double bond formed between carbon atoms excluding carbon atoms forming an aromatic ring, and the term "ethylenically unsaturated monomer" means a monomer having an ethylenically unsaturated bond.

[0014] In this specification, the "weight average molecular weight" and "number average molecular weight" refer to values ​​measured using gel permeation chromatography (GPC) at room temperature (23°C) under the following conditions and determined using a standard polystyrene calibration curve. Apparatus: Shodex™ GPC-101 (Resonac Inc.) Column: Shodex™ LF-804 (Resonac Inc.) Column temperature: 40°C Sample: 0.2% by mass solution of sample in tetrahydrofuran Flow rate: 1 mL / min Eluent: Tetrahydrofuran Detector: Shodex™ RI-71S (Resonac Inc.)

[0015] In this specification, the term "acid value" refers to the acid value measured in accordance with JIS K6901:2021 5.3. That is, the acid value refers to the number of milligrams of potassium hydroxide required to neutralize the acidic components contained in 1 g of nonvolatile matter excluding the solvent.

[0016] <Motor> A motor is a device that generates a rotational force by passing current through an internal coil to generate an electromagnetic force and by the repulsive or attractive force between the coil and a main shaft or a permanent magnet or electromagnet provided around the main shaft. Generally, a motor includes a stator having a stator core and a coil wound around the stator core, and a rotating body including a magnetic component. A motor in which the stator is covered with a molding material is also called a molded motor. In this specification, a stator covered with a molding material is referred to as a molded stator.

[0017] In one embodiment, the motor comprises: a molded stator; a rotating shaft extending in the axial direction; a rotating body including a magnetic component, extending in the axial direction, and fixed to the rotating shaft, the rotor being positioned inside the stator; and a bearing that rotatably supports the rotor.

[0018] In the motor, the molding material constituting the molded stator is a cured product of a thermosetting resin composition, which will be described later. The components of the motor other than the molding material may be any known components.

[0019] A cross-sectional view of an exemplary motor is shown in FIG. 1. Detailed components such as brackets and insulators attached to the coils are omitted from FIG. 1. In FIG. 1, motor 10 includes stator 11, rotor 15, and bearings 19 that rotatably support rotor 15. Stator 11 includes stator core 12 made of multiple metal plates and coils 13 with windings wound around stator core 12. Stator 11 is covered with molding material 14. Rotor 15 is located inside stator 11. Rotor 15 includes a rotating shaft 17 extending axially and a rotating body 18 fixed to rotating shaft 17, and rotating body 18 includes magnets 16.

[0020] <Molded Stator> The molded stator is a stator covered with a molding material. In one embodiment, the molded stator includes a stator having a stator core and a coil wound around the stator core, and a molding material that covers the stator. Note that the entire stator does not need to be covered with the molding material.

[0021] The molding material constituting the molded stator is a cured product of a thermosetting resin composition described below. The components of the molded stator other than the molding material may be any known component. There are no particular limitations on the motor to which the molded stator is applied, and any known component may be used.

[0022] <Molding Material> The molding material is a cured product of a thermosetting resin composition, which will be described later. By using the molding material, a motor with low noise and vibration can be obtained.

[0023] <Thermosetting Resin Composition> A thermosetting resin composition according to one embodiment contains (A) a saturated polyester resin having a specific structure, (B) a thermosetting resin, (C) an ethylenically unsaturated monomer, (D) a thermal polymerization initiator, (E) glass fibers, (F) an inorganic filler, and (G) a thickener, wherein the (G) thickener is at least one selected from the group consisting of styrene-butadiene rubber (SBR), styrene-butadiene-styrene rubber (SBS), and styrene-ethylene-butadiene-styrene rubber (SEBS), and the content of the (G) thickener is 0.8 to 9 parts by mass, relative to 100 parts by mass of the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer. The (A) saturated polyester resin is a polycondensation product of a diol and a saturated polybasic acid, and the saturated polybasic acid contains an aromatic saturated polybasic acid or its acid anhydride and an aliphatic saturated polybasic acid. The (A) saturated polyester resin contains a structure derived from the aromatic saturated polybasic acid or its acid anhydride and a structure derived from the aliphatic saturated polybasic acid in a molar ratio of 20:80 to 80:20. The (A) saturated polyester resin contains a block (X) that is a polycondensation product of a diol and an aromatic saturated polybasic acid or its acid anhydride, and a block (Y) that is a polycondensation product of a diol and an aliphatic saturated polybasic acid, and the weight-average molecular weight of the block (X) is 3,000 to 5,000. The cured product of the thermosetting resin composition is suitable for use as a molding material for covering a stator. By using a cured product of a thermosetting resin composition containing the (A) saturated polyester resin having a specific structure as a molding material, a molded stator with a good appearance and no cracks can be obtained. Furthermore, a molded stator having excellent durability against heat cycles can be obtained. By using a specific amount of the thickener (G), a thermosetting resin composition having excellent filling properties during molding can be obtained, and a molded stator without chipping can be obtained.

[0024] [(A) Saturated Polyester Resin] The (A) saturated polyester resin is a polycondensate of a diol and a saturated polybasic acid, and the saturated polybasic acid contains an aromatic saturated polybasic acid or its acid anhydride and an aliphatic saturated polybasic acid. In the (A) saturated polyester resin, the content ratio (molar ratio) of the structure derived from the aromatic saturated polybasic acid or its acid anhydride to the structure derived from the aliphatic saturated polybasic acid is 20:80 to 80:20. The (A) saturated polyester resin contains a block (X) which is a polycondensate of a diol and an aromatic saturated polybasic acid or its acid anhydride, and a block (Y) which is a polycondensate of a diol and an aliphatic saturated polybasic acid, and the weight-average molecular weight of the block (X) is 3,000 to 5,000.

[0025] The saturated polyester resin (A) may be used alone or in combination of two or more thereof. By using the saturated polyester resin (A), the occurrence of cracks during molding is suppressed.

[0026] In the present disclosure, styrene monomers and the like contained in commercially available saturated polyester resins are classified as (C) ethylenically unsaturated monomers.

[0027] The diol is not particularly limited as long as it is a compound having two hydroxyl groups. Examples of diols include alkylene glycols such as ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, neopentyl glycol, 2-methyl-1,3-propanediol, 1,4-cyclohexanedimethanol, and hydrogenated bisphenol A; polyoxyalkylene polyols such as diethylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol, and polyethylene glycol; bisphenol A; and alkylene oxide-modified bisphenol A such as an ethylene oxide adduct of bisphenol A and a propylene oxide adduct of bisphenol A. From the viewpoint of crack resistance during molding, one or more selected from the group consisting of alkylene glycols and polyoxyalkylene polyols are preferred, polyoxyalkylene glycols are more preferred, and one or more selected from diethylene glycol, dipropylene glycol, and triethylene glycol are even more preferred. In particular, from the viewpoint of improving the durability of molded articles, it is preferable to use polyoxyethylene glycol and polyoxypropylene glycol in combination, and it is more preferable to use diethylene glycol and dipropylene glycol in combination. The content ratio (molar ratio) of polyoxyethylene glycol to polyoxypropylene glycol or the content ratio (molar ratio) of diethylene glycol to dipropylene glycol is not particularly limited, but from the viewpoint of improving durability, it is preferably 40:60 to 80:20, more preferably 50:50 to 70:30, even more preferably 55:45 to 65:35, and particularly preferably 58:42 to 63:37. The diols may be used alone or in combination of two or more.

[0028] The saturated polybasic acid contains an aromatic saturated polybasic acid or its acid anhydride and an aliphatic saturated polybasic acid. Examples of aromatic saturated polybasic acids or their acid anhydrides include phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, nitrophthalic acid, and halogenated phthalic anhydride. The aromatic saturated polybasic acid or its acid anhydride is preferably one or more selected from the group consisting of aromatic saturated dibasic acids and their acid anhydrides, more preferably one or more selected from phthalic acid, phthalic anhydride, isophthalic acid, and terephthalic acid, and even more preferably one or more selected from isophthalic acid and terephthalic acid. The aromatic saturated polybasic acid or its acid anhydride may be used alone or in combination. Examples of aliphatic saturated polybasic acids include succinic acid, adipic acid, sebacic acid, oxalic acid, malonic acid, azelaic acid, and glutaric acid. The aliphatic saturated polybasic acid is preferably an aliphatic saturated dibasic acid, more preferably an aliphatic saturated dibasic acid having 4 to 10 carbon atoms, and even more preferably one or more selected from succinic acid, adipic acid, and sebacic acid. The aliphatic saturated polybasic acids may be used alone or in combination of two or more. From the viewpoint of crack resistance during molding, it is preferable to use one or more selected from isophthalic acid and terephthalic acid in combination with one or more selected from succinic acid, adipic acid, and sebacic acid.

[0029] The total ratio of the aromatic saturated polybasic acid and the acid anhydride of the aromatic saturated polybasic acid to the total of the aromatic saturated polybasic acid, the acid anhydride of the aromatic saturated polybasic acid, and the aliphatic saturated polybasic acid is preferably 20 mol% or more, more preferably 30 mol% or more, and even more preferably 40 mol% or more. The total ratio of the aromatic saturated polybasic acid and the acid anhydride of the aromatic saturated polybasic acid to the total of the aromatic saturated polybasic acid, the acid anhydride of the aromatic saturated polybasic acid, and the aliphatic saturated polybasic acid is preferably 80 mol% or less, more preferably 70 mol% or less, and even more preferably 60 mol% or less. If the total ratio of the aromatic saturated polybasic acid and the acid anhydride of the aromatic saturated polybasic acid is within the above range, the moldability is better and the properties of the cured product can be further improved.

[0030] The ratio of the aliphatic saturated polybasic acid to the total of the aromatic saturated polybasic acid, the acid anhydride of the aromatic saturated polybasic acid, and the aliphatic saturated polybasic acid is preferably 20 mol% or more, more preferably 30 mol% or more, and even more preferably 40 mol% or more. The ratio of the aliphatic saturated polybasic acid to the total of the aromatic saturated polybasic acid, the acid anhydride of the aromatic saturated polybasic acid, and the aliphatic saturated polybasic acid is preferably 80 mol% or less, more preferably 70 mol% or less, and even more preferably 60 mol% or less. If the ratio of the aliphatic saturated polybasic acid is within the above range, crack resistance can be improved.

[0031] In the saturated polyester resin (A), the content ratio (molar ratio) of the structure derived from an aromatic saturated polybasic acid or an acid anhydride thereof to the structure derived from an aliphatic saturated polybasic acid is 20:80 to 80:20, preferably 30:70 to 70:30, and more preferably 40:60 to 60:40.

[0032] From the viewpoint of crack resistance during molding, the (A) saturated polyester resin includes a block (X) which is a polycondensate of a diol and an aromatic saturated polybasic acid or an acid anhydride thereof, and has a weight-average molecular weight of 3,000 to 5,000, and a block (Y) which is a polycondensate of a diol and an aliphatic saturated polybasic acid.

[0033] In the saturated polyester resin (A), a structure derived from an aromatic saturated polybasic acid or an acid anhydride thereof may be interspersed in portions other than the block (X) and the block (Y).

[0034] The weight-average molecular weight of block (X) is 3000 or more, preferably 3500 or more. The weight-average molecular weight of block (X) is 5000 or less, preferably 4500 or less. When the weight-average molecular weight of block (X) is within the above range, crack resistance during molding is good.

[0035] The aromatic saturated polybasic acid or acid anhydride thereof constituting the block (X) is preferably one or more selected from the group consisting of aromatic saturated dibasic acids and acid anhydrides thereof, more preferably one or more selected from phthalic acid, phthalic anhydride, isophthalic acid, and terephthalic acid, and even more preferably one or more selected from isophthalic acid and terephthalic acid.

[0036] The aliphatic saturated polybasic acid constituting the block (Y) is preferably an aliphatic saturated dibasic acid, more preferably an aliphatic saturated dibasic acid having 4 to 10 carbon atoms, and even more preferably one or more selected from succinic acid, adipic acid, and sebacic acid.

[0037] A preferred combination of diol and saturated polybasic acid includes polyoxyalkylene glycol and saturated dibasic acid. More specifically, for example, a combination of diethylene glycol and isophthalic acid, a combination of diethylene glycol and adipic acid, a combination of dipropylene glycol and isophthalic acid, a combination of dipropylene glycol and adipic acid, a combination of diethylene glycol, isophthalic acid and adipic acid, a combination of dipropylene glycol, isophthalic acid and adipic acid, a combination of diethylene glycol, dipropylene glycol, isophthalic acid and adipic acid, a combination of diethylene glycol, dipropylene glycol, isophthalic acid and adipic acid, etc. Among them, the combination of diethylene glycol, isophthalic acid and adipic acid, the combination of dipropylene glycol, isophthalic acid and adipic acid, and the combination of diethylene glycol, dipropylene glycol, isophthalic acid and adipic acid are preferred because they have good crack resistance during molding.

[0038] The weight-average molecular weight of the (A) saturated polyester resin is preferably 9,500 or more, more preferably 9,800 or more, and even more preferably 10,000 or more. The weight-average molecular weight of the (A) saturated polyester resin is preferably 13,500 or less, more preferably 13,000 or less, and even more preferably 12,500 or less. When the weight-average molecular weight is within the above range, cracking during molding is further suppressed. Without being bound by any theory, it is believed that by setting the weight-average molecular weight of the (A) saturated polyester resin within the above range, compatibility with the (B) thermosetting resin and dispersibility of the (C) to (G) components are improved, thereby suppressing cracking during molding. The weight-average molecular weight of the (A) saturated polyester resin can be adjusted by the reaction time during synthesis of the (A) saturated polyester resin. Specifically, the longer the reaction time, the higher the weight-average molecular weight, and the shorter the reaction time, the lower the weight-average molecular weight.

[0039] The content of the (A) saturated polyester resin in the thermosetting resin composition is preferably 5 parts by mass or more, more preferably 8 parts by mass or more, and even more preferably 10 parts by mass or more, based on 100 parts by mass of the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer. The content of the (A) saturated polyester resin in the thermosetting resin composition is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, and even more preferably 20 parts by mass or less, based on 100 parts by mass of the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer. The content of the (A) saturated polyester resin in the thermosetting resin composition is preferably 5 to 30 parts by mass, more preferably 8 to 25 parts by mass, and even more preferably 10 to 20 parts by mass, based on 100 parts by mass of the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer. If the content of the (A) saturated polyester resin in the thermosetting resin composition is 5 parts by mass or more, the occurrence of cracks during molding can be further suppressed. When the content of the saturated polyester resin (A) in the thermosetting resin composition is 30 parts by mass or less, the moldability of the thermosetting resin composition and the mechanical properties of the cured product are better.

[0040] (Method for synthesizing (A) saturated polyester resin) The (A) saturated polyester resin can be synthesized by a known method using the above-mentioned raw materials. Various conditions for synthesizing the (A) saturated polyester resin are appropriately set depending on the raw materials used and their amounts.

[0041] Generally, the esterification reaction can be carried out in a stream of an inert gas such as nitrogen gas at a temperature of 140°C to 230°C under pressure or reduced pressure. In the esterification reaction, an esterification catalyst can be used as needed. Examples of the esterification catalyst include known catalysts such as manganese acetate, dibutyltin oxide, stannous oxalate, zinc acetate, and cobalt acetate. The esterification catalysts may be used alone or in combination of two or more.

[0042] The equivalent of the hydroxyl groups of the diol relative to the total amount of carboxyl groups of the saturated polybasic acid is preferably in the range of 0.9 to 1.2.

[0043] From the viewpoint of crack resistance during molding, the (A) saturated polyester resin contains a block (X) which is a polycondensate of a diol and an aromatic saturated polybasic acid or its acid anhydride, and a block (Y) which is a polycondensate of a diol and an aliphatic saturated polybasic acid. Such (A) saturated polyester resin can be obtained by first charging one of the saturated polybasic acids into a reaction vessel, allowing the esterification reaction to proceed until a certain amount of the saturated polybasic acid is consumed, then charging the other saturated polybasic acid into the reaction vessel, and allowing the esterification reaction to proceed until a desired weight-average molecular weight is obtained. For example, the (A) saturated polyester resin can be synthesized as follows: first, a diol equivalent to the total amount of the aromatic saturated polybasic acid or its acid anhydride and the aliphatic saturated polybasic acid and the aromatic saturated polybasic acid or its acid anhydride are charged into the reaction vessel, and the esterification reaction is allowed to proceed until a certain amount of the aromatic saturated polybasic acid or its acid anhydride is consumed, then charging the aliphatic saturated polybasic acid into the reaction vessel, and allowing the esterification reaction to proceed.

[0044] The weight-average molecular weight of block (X) can be adjusted by adjusting the timing of adding the subsequently added aliphatic saturated polybasic acid. For example, the acid value of the reaction solution, i.e., the remaining amount of the previously added aromatic saturated polybasic acid or its acid anhydride, can be traced, and the aliphatic saturated polybasic acid can be added when the remaining amount reaches the desired amount. From the viewpoint of crack resistance, the acid value of the reaction solution when the aliphatic saturated polybasic acid is added is preferably 30 KOHmg / g or less, more preferably 20 KOHmg / g or less, and even more preferably 10 KOHmg / g or less. The acid value of the reaction solution when the aliphatic saturated polybasic acid is added may be 1 KOHmg / g or more, 3 KOHmg / g or more, or 5 KOHmg / g or more.

[0045] [(B) Thermosetting Resin] The (B) thermosetting resin is not particularly limited as long as it is a thermosetting resin generally used for sealing material applications. For example, a resin having a functional group capable of forming a crosslinked structure when the thermosetting resin composition is cured by heating is preferred. In particular, a resin having a plurality of ethylenically unsaturated groups as functional groups is preferred from the viewpoint of being able to react with the (C) ethylenically unsaturated monomer.

[0046] The weight-average molecular weight of the (B) thermosetting resin is preferably 2,000 or more, more preferably 5,000 or more, and even more preferably 10,000 or more. The weight-average molecular weight of the (B) thermosetting resin is preferably 50,000 or less, more preferably 40,000 or less, and even more preferably 35,000 or less. When the weight-average molecular weight is within the above range, cracking during molding is further suppressed. Without being bound by any theory, it is believed that by setting the weight-average molecular weight of the (B) thermosetting resin within the above range, compatibility with the (A) saturated polyester resin and dispersibility of the (C) to (G) components are improved, thereby suppressing cracking during molding. Note that the weight-average molecular weight of the (B) thermosetting resin refers to the weight-average molecular weight of the resin in an uncured state.

[0047] Specific examples of the (B) thermosetting resin include (B-1) unsaturated polyester resin, (B-2) vinyl ester resin, (B-3) urethane (meth)acrylate resin, (B-4) diallyl phthalate resin, and (B-5) epoxy resin. From the viewpoints of moldability, fluidity, and cure shrinkage, the (B) thermosetting resin preferably contains (B-1) unsaturated polyester resin. The (B) thermosetting resin may be used alone or in combination of two or more types.

[0048] The content of the (B) thermosetting resin in the thermosetting resin composition is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more, based on 100 parts by mass of the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer. The content of the (B) thermosetting resin in the thermosetting resin composition is preferably 80 parts by mass or less, more preferably 60 parts by mass or less, and even more preferably 40 parts by mass or less, based on 100 parts by mass of the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer. When the content of the (B) thermosetting resin in the thermosetting resin composition is 5 parts by mass or more, the mechanical strength of the cured product is good. When the content of the (B) thermosetting resin in the thermosetting resin composition is 80 parts by mass or less, the viscosity of the thermosetting resin composition can be adjusted to an appropriate range, and the moldability is good.

[0049] <(B-1) Unsaturated Polyester Resin> The (B-1) unsaturated polyester resin is a polycondensate of a polyhydric alcohol and an unsaturated polybasic acid, or a polycondensate of a polyhydric alcohol, an unsaturated polybasic acid, and a saturated polybasic acid, and is not particularly limited. The (B-1) unsaturated polyester resin is preferably a polycondensate of a diol, an unsaturated polybasic acid, and an optional saturated polybasic acid, more preferably a polycondensate of a diol containing propylene glycol, an unsaturated polybasic acid, and an optional saturated polybasic acid, and even more preferably a polycondensate of a diol containing propylene glycol and neopentyl glycol, an unsaturated polybasic acid, and an optional saturated aromatic polybasic acid.

[0050] The unsaturated polyester resin (B-1) may be used alone or in combination of two or more. By using the unsaturated polyester resin (B-1), a cured product having excellent mechanical strength and heat resistance can be obtained.

[0051] In the present disclosure, reactive diluents such as styrene monomers contained in commercially available unsaturated polyester resins are classified as (C) ethylenically unsaturated monomers.

[0052] The polyhydric alcohol is not particularly limited as long as it is a compound having two or more hydroxyl groups. The polyhydric alcohol is preferably one or more selected from the group consisting of diols and triols, and more preferably a diol. Examples of the polyhydric alcohol include alkylene glycols such as ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, neopentyl glycol, 2-methyl-1,3-propanediol, 1,4-cyclohexanedimethanol, and hydrogenated bisphenol A; polyoxyalkylene polyols such as diethylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol, and polyethylene glycol; bisphenol A; alkylene oxide-modified bisphenol A such as an ethylene oxide adduct of bisphenol A and a propylene oxide adduct of bisphenol A; and glycerin. From the viewpoint of crack resistance during molding, alkylene glycols are preferred, alkylene glycols having 2 to 6 carbon atoms are more preferred, and one or more selected from ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, and neopentyl glycol are even more preferred, with propylene glycol being particularly preferred. From the viewpoint of improving the durability of molded articles, it is preferable to use propylene glycol and neopentyl glycol in combination. From the viewpoint of chemical resistance, it is preferable to use propylene glycol and hydrogenated bisphenol A in combination. The polyhydric alcohols may be used alone or in combination of two or more.

[0053] The unsaturated polybasic acid is not particularly limited as long as it is a compound having an ethylenically unsaturated bond and two or more carboxy groups, or an acid anhydride thereof, and known compounds can be used. Unsaturated polybasic acids having 4 to 6 carbon atoms or acid anhydrides thereof are particularly preferred because they are less expensive and can produce thermosetting resin compositions with superior mechanical strength and heat resistance in cured products. The unsaturated polybasic acid is preferably an unsaturated dibasic acid. Examples of unsaturated polybasic acids include maleic acid, maleic anhydride, fumaric acid, citraconic acid, itaconic acid, and chloromaleic acid. More preferably, the unsaturated polybasic acid is one or more selected from fumaric acid, maleic acid, maleic anhydride, and itaconic acid. The unsaturated polybasic acids may be used alone or in combination.

[0054] A preferred combination of a polyhydric alcohol and an unsaturated polybasic acid is a diol and an unsaturated dibasic acid, and more preferably an alkylene glycol and an unsaturated dibasic acid having 4 to 6 carbon atoms. More specific examples include a combination of maleic anhydride, propylene glycol, and neopentyl glycol, a combination of maleic anhydride and propylene glycol, a combination of fumaric acid and propylene glycol, a combination of maleic anhydride, propylene glycol, neopentyl glycol, and hydrogenated bisphenol A, and a combination of maleic anhydride, fumaric acid, propylene glycol, neopentyl glycol, and hydrogenated bisphenol A. The combinations of maleic anhydride, propylene glycol, and neopentyl glycol, and the combination of maleic anhydride and propylene glycol are preferred because they are lower in cost and improve crack resistance during molding and the durability of molded products.

[0055] The saturated polybasic acid is not particularly limited as long as it is a compound having no ethylenically unsaturated bond and two or more carboxy groups or an acid anhydride thereof, and known compounds can be used. Examples of saturated polybasic acids include aromatic saturated polybasic acids or acid anhydrides thereof such as phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, nitrophthalic acid, and halogenated phthalic anhydride; aliphatic saturated polybasic acids such as succinic acid, adipic acid, sebacic acid, oxalic acid, malonic acid, azelaic acid, and glutaric acid; and acid anhydrides of cyclic aliphatic saturated polybasic acids such as hexahydrophthalic anhydride. The saturated polybasic acids may be used alone or in combination of two or more.

[0056] The weight-average molecular weight of the (B-1) unsaturated polyester resin is not particularly limited. The weight-average molecular weight of the (B-1) unsaturated polyester resin is preferably 2,000 to 50,000, more preferably 5,000 to 50,000, even more preferably 10,000 to 50,000, and particularly preferably 13,000 to 35,000. A weight-average molecular weight of 2,000 to 50,000 further improves the moldability of the thermosetting resin composition. A weight-average molecular weight of 2,000 to 50,000 further suppresses cracking during molding. Without being bound by any theory, it is believed that by setting the weight-average molecular weight of the (B-1) unsaturated polyester resin within the above range, compatibility with the (A) saturated polyester resin and dispersibility of the (C) to (G) components are improved, thereby suppressing cracking during molding.

[0057] The degree of unsaturation of the unsaturated polyester resin (B-1) is preferably 50 to 100 mol %, more preferably 60 to 100 mol %, and even more preferably 70 to 100 mol %. When the degree of unsaturation is within the above range, the moldability of the thermosetting resin composition containing the unsaturated polyester resin (B-1) is improved.

[0058] The degree of unsaturation of the (B-1) unsaturated polyester resin can be calculated using the number of moles of the unsaturated polybasic acid and saturated polybasic acid used as raw materials according to the following formula: Degree of unsaturation (mol %) = {(number of moles of unsaturated polybasic acid × number of ethylenically unsaturated bonds per molecule of unsaturated polybasic acid) / (number of moles of unsaturated polybasic acid + number of moles of saturated polybasic acid)} × 100

[0059] (Method for synthesizing (B-1) unsaturated polyester resin) The (B-1) unsaturated polyester resin can be synthesized by a known method using the above-mentioned raw materials. The various conditions for synthesizing the (B-1) unsaturated polyester resin are appropriately set depending on the raw materials used and their amounts.

[0060] Generally, the esterification reaction can be carried out in a stream of an inert gas such as nitrogen gas at a temperature of 140°C to 230°C under pressure or reduced pressure. In the esterification reaction, an esterification catalyst can be used as needed. Examples of the esterification catalyst include known catalysts such as manganese acetate, dibutyltin oxide, stannous oxalate, zinc acetate, and cobalt acetate. The esterification catalysts may be used alone or in combination of two or more.

[0061] In order to increase the molecular weight by improving the reaction rate, it is preferable that the equivalent weight of the hydroxyl groups of the polyhydric alcohol is in the range of 0.9 to 1.2 relative to the total amount of carboxyl groups of the unsaturated polybasic acid and any saturated polybasic acid.

[0062] The content of the unsaturated polyester resin (B-1) in the thermosetting resin (B) is preferably 75% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more. When the content of the unsaturated polyester resin (B-1) is 75% by mass or more, appropriate moldability, fluidity, and cure shrinkage can be ensured. There is no particular upper limit for the content of the unsaturated polyester resin (B-1) in the thermosetting resin (B). For example, it may be 100% by mass, 97% by mass, or 95% by mass.

[0063] <(B-2) Vinyl Ester Resin> (B-2) vinyl ester resin is generally a compound having an ethylenically unsaturated bond obtained by a ring-opening reaction between (a) an epoxy group in an epoxy compound having two or more epoxy groups and (b) a carboxy group of an unsaturated monobasic acid having an ethylenically unsaturated bond and a carboxy group. (B-2) vinyl ester resin is described, for example, in Polyester Resin Handbook (published by The Nikkan Kogyo Shimbun, Ltd. in 1988).

[0064] The (B-2) vinyl ester resin may be used alone or in combination of two or more. In terms of handling, the (B-2) vinyl ester resin is generally used after being diluted with the (C) ethylenically unsaturated monomer. By using the (B-2) vinyl ester resin, the material cost of the thermosetting resin composition can be reduced.

[0065] The weight average molecular weight (Mw) of the vinyl ester resin (B-2) can be adjusted depending on the desired physical properties, but from the viewpoint of handling, it is preferably in the range of 500 to 5,000.

[0066] ((a) Epoxy Compound) The (a) epoxy compound is not particularly limited as long as it is a compound having two or more epoxy groups. Preferably, it is at least one selected from the group consisting of bisphenol-type epoxy compounds and novolac phenol-type epoxy compounds, more preferably a bisphenol-type epoxy compound. By using the (B-2) vinyl ester resin using the (a) epoxy compound as a raw material, the mechanical strength and corrosion resistance of the cured product are further improved.

[0067] Examples of bisphenol epoxy compounds include those obtained by reacting a bisphenol compound such as bisphenol A, bisphenol F, bisphenol S, and tetrabromobisphenol A with epichlorohydrin and / or methylepichlorohydrin; and those obtained by reacting a condensate of a compound obtained by glycidyl etherifying one or more of the above bisphenol compounds with epichlorohydrin and / or methylepichlorohydrin. From the viewpoint of durability, a reaction product of a bisphenol compound with epichlorohydrin is preferred, and a reaction product of bisphenol A with epichlorohydrin is more preferred.

[0068] Examples of novolak phenol type epoxy compounds include those obtained by reacting phenol novolak or cresol novolak with epichlorohydrin and / or methyl epichlorohydrin.

[0069] (b) Unsaturated Monobasic Acid) The (b) unsaturated monobasic acid is not particularly limited as long as it is a monocarboxylic acid having an ethylenically unsaturated bond. Preferred are methacrylic acid, acrylic acid, crotonic acid, cinnamic acid, etc., more preferably acrylic acid or methacrylic acid, and from the viewpoint of the corrosion resistance of the cured product, even more preferably methacrylic acid.

[0070] (Method for Synthesizing (B-2) Vinyl Ester Resin) The (B-2) vinyl ester resin can be synthesized by a known synthesis method. For example, there can be mentioned a method in which, in a reaction vessel capable of being heated and stirred, an unsaturated monobasic acid (b) is added in the presence of an esterification catalyst and an epoxy compound (a), and the reaction is carried out at 70 to 150°C, preferably 80 to 140°C, and more preferably 90 to 130°C.

[0071] As the esterification catalyst, for example, known catalysts such as tertiary amines such as triethylamine, N,N-dimethylbenzylamine, N,N-dimethylaniline and diazabicyclooctane, triphenylphosphine and diethylamine hydrochloride can be used.

[0072] The compounding ratio of the (a) epoxy compound and the (b) unsaturated monobasic acid is preferably such that the total amount of carboxy groups in the (b) unsaturated monobasic acid is 0.3 to 1.2 mol per 1 mol of the total amount of epoxy groups in the (a) epoxy compound, more preferably 0.4 to 1.1 mol, and even more preferably 0.5 to 1.0 mol. When the total amount of carboxy groups in the (b) unsaturated monobasic acid is 0.3 mol or more, a cured product with sufficient hardness can be obtained when the thermosetting resin composition is cured. On the other hand, when the total amount of carboxy groups in the (b) unsaturated monobasic acid is 1.2 mol or less, the amount of unreacted (b) unsaturated monobasic acid can be reduced during the synthesis of the (B-2) vinyl ester resin, and thus a cured product with excellent mechanical strength can be obtained.

[0073] Since unreacted (b) unsaturated monobasic acid may volatilize when the thermosetting resin composition is heat-cured, it is preferable to reduce the content of unreacted (b) unsaturated monobasic acid as much as possible. For example, the content of unreacted (b) unsaturated monobasic acid is preferably 5% by mass or less, and more preferably 3% by mass or less, relative to the total amount of the (B-2) vinyl ester resin and unreacted (b) unsaturated monobasic acid.

[0074] The content of the vinyl ester resin (B-2) in the thermosetting resin (B) may be 1% by mass or more, 3% by mass or more, or 5% by mass or more. The upper limit of the content of the vinyl ester resin (B-2) in the thermosetting resin (B) is not particularly limited. For example, it may be 25% by mass, 20% by mass, or 10% by mass.

[0075] <(B-3) Urethane (meth)acrylate resin> Examples of the (B-3) urethane (meth)acrylate resin include resins obtained by introducing (meth)acryloyl groups into hydroxyl groups or isocyanato groups at both ends of polyurethane obtained by reacting a polyisocyanate with a polyhydric alcohol.

[0076] As the polyhydric alcohol, the compounds described as raw materials for the unsaturated polyester resin (B-1) above can be used without any particular limitation.

[0077] Examples of polyisocyanates include aliphatic polyisocyanates such as hexamethylene diisocyanate, lysine diisocyanate, lysine triisocyanate, and trimethylhexane diisocyanate; alicyclic polyisocyanates such as hydrogenated xylylene diisocyanate, isophorone diisocyanate, methylcyclohexane-2,4 (or 2,6)-diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), and 1,3-(isocyanatomethyl)cyclohexane; aromatic polyisocyanates such as tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, and triphenylmethane triisocyanate; and adducts, isocyanurates, and biurets of these polyisocyanates. The polyisocyanates may be used alone or in combination of two or more.

[0078] When introducing a (meth)acryloyl group, for example, a method of reacting a terminal isocyanato group with a hydroxyl group-containing (meth)acrylic compound, or a method of reacting a terminal hydroxyl group with an isocyanato group-containing (meth)acrylic compound such as 2-(meth)acryloyloxyethyl isocyanate, 2-(meth)acryloyloxypropyl isocyanate, or 1,1-bis(acryloyloxymethyl)ethyl isocyanate can be used. Examples of hydroxyl group-containing (meth)acrylic compounds include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, caprolactone-modified hydroxyalkyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, tris(hydroxyethyl)isocyanuric acid di(meth)acrylate, pentaerythritol tri(meth)acrylate, glycerin mono(meth)acrylate, and hydroxyethyl acrylamide, with 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, caprolactone-modified hydroxyalkyl (meth)acrylate, and hydroxyethyl acrylamide being preferred. The isocyanato group-containing (meth)acrylic compounds and hydroxyl group-containing (meth)acrylic compounds may each be used alone or in combination of two or more.

[0079] The content of the urethane (meth)acrylate resin (B-3) in the thermosetting resin (B) may be 1% by mass or more, 3% by mass or more, or 5% by mass or more. The upper limit of the content of the urethane (meth)acrylate resin (B-3) in the thermosetting resin (B) is not particularly limited. For example, it may be 25% by mass, 20% by mass, or 10% by mass.

[0080] <(B-4) Diallyl phthalate resin> The (B-4) diallyl phthalate resin is an oligomer of diallyl phthalate, and conventionally known diallyl phthalate resins can be used without particular limitation. The (B-4) diallyl phthalate resins can be used alone or in combination of two or more.

[0081] The content of the diallyl phthalate resin (B-4) in the thermosetting resin (B) may be 1% by mass or more, 3% by mass or more, or 5% by mass or more. The upper limit of the content of the diallyl phthalate resin (B-4) in the thermosetting resin (B) is not particularly limited. For example, it may be 25% by mass, 20% by mass, or 10% by mass.

[0082] <(B-5) Epoxy Resin> As the (B-5) epoxy resin, the compounds described in the section (a) Epoxy Compound for the (B-2) Vinyl Ester Resin can be used. The (B-5) epoxy resin may be used alone or in combination of two or more types.

[0083] The content of the epoxy resin (B-5) in the thermosetting resin (B) may be 1% by mass or more, 3% by mass or more, or 5% by mass or more. The upper limit of the content of the epoxy resin (B-5) in the thermosetting resin (B) is not particularly limited. For example, it may be 25% by mass, 20% by mass, or 10% by mass.

[0084] [(C) Ethylenically Unsaturated Monomer] The (C) ethylenically unsaturated monomer is not particularly limited as long as it is a monomer having an ethylenically unsaturated bond. The (C) ethylenically unsaturated monomer may be used alone or in combination of two or more kinds.

[0085] Specific examples include vinyl compounds such as styrene, vinyltoluene, t-butylstyrene, methoxystyrene, divinylbenzene, and vinylnaphthalene; methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, furfuryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, phenyl (meth)acrylate, and benzyl (meth)acrylate. (Meth)acrylates such as acrylate, phenoxyethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, allyl (meth)acrylate, isobornyl (meth)acrylate, acetoacetoxyethyl (meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, tricyclodecanol di(meth)acrylate, and trimethylolpropane tri(meth)acrylate; and cyclic unsaturated compounds such as acenaphthylene and norbornene. From the viewpoint of copolymerizability with the (B) thermosetting resin, vinyl compounds are preferred, and one or more selected from styrene, vinyltoluene, t-butylstyrene, and methoxystyrene are more preferred, with styrene being even more preferred.

[0086] The content of the (C) ethylenically unsaturated monomer in the thermosetting resin composition is preferably 20 parts by mass or more, more preferably 40 parts by mass or more, and even more preferably 60 parts by mass or more, based on 100 parts by mass of the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer. The content of the (C) ethylenically unsaturated monomer in the thermosetting resin composition is preferably 95 parts by mass or less, more preferably 90 parts by mass or less, and even more preferably 80 parts by mass or less, based on 100 parts by mass of the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer. When the content of the (C) ethylenically unsaturated monomer in the thermosetting resin composition is 20 parts by mass or more, the viscosity of the thermosetting resin composition can be adjusted within an appropriate range, and the moldability is good. When the content of the (C) ethylenically unsaturated monomer in the thermosetting resin composition is 95 parts by mass or less, the mechanical strength of the cured product is good.

[0087] [(D) Thermal Polymerization Initiator] The (D) thermal polymerization initiator is not particularly limited as long as it is a polymerization initiator that generates radicals upon heating. Examples thereof include organic peroxides such as diacyl peroxides, peroxyesters, hydroperoxides, dialkyl peroxides, ketone peroxides, peroxyketals, alkyl peresters, and percarbonates.

[0088] Among these organic peroxides, the preferred thermal polymerization initiator (D) is 1,1-di-t-hexylperoxycyclohexane, t-hexylperoxyisopropyl carbonate, t-butylperoxyoctoate, t-butylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t-amylperoxy-2-ethylhexanoate, benzoyl peroxide, 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, t-butylperoxyisopropyl carbonate, t-butylperoxybenzoate, dicumyl peroxide, and di-t-butyl peroxide. The thermal polymerization initiator (D) may be used alone or in combination of two or more.

[0089] The content of the (D) thermal polymerization initiator in the thermosetting resin composition is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 3 parts by mass or more, based on 100 parts by mass of the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer. The content of the (D) thermal polymerization initiator in the thermosetting resin composition is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less, based on 100 parts by mass of the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer. When the content of the (D) thermal polymerization initiator in the thermosetting resin composition is 0.5 parts by mass or more, the curing reaction during molding of the thermosetting resin composition proceeds uniformly, resulting in better physical properties and appearance of the cured product. When the content of the (D) thermal polymerization initiator in the thermosetting resin composition is 20 parts by mass or less, the storage stability of the thermosetting resin composition is improved, and handleability is improved.

[0090] [(E) Glass Fiber] The (E) glass fiber is not particularly limited as long as it is a fibrous substance having an aspect ratio of at least 3. Specific examples include chopped strand glass.

[0091] The fiber length of the (E) glass fiber is preferably 20 mm or less, more preferably 10 mm or less, and even more preferably 5 mm or less. When the fiber length is 20 mm or less, the moldability of the thermosetting resin composition is good, and the appearance of the cured product is good. The fiber length is preferably 0.1 mm or more, more preferably 0.5 mm or more, and even more preferably 1 mm or more. When the fiber length is 0.1 mm or more, the strength of the cured product is good. The average fiber diameter of the (E) glass fiber is preferably 3 to 100 μm, and more preferably 5 to 30 μm.

[0092] The content of the (E) glass fiber in the thermosetting resin composition is preferably 5 parts by mass or more, more preferably 20 parts by mass or more, and even more preferably 40 parts by mass or more, based on 100 parts by mass of the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer. The content of the (E) glass fiber in the thermosetting resin composition is preferably 200 parts by mass or less, more preferably 150 parts by mass or less, and even more preferably 100 parts by mass or less, based on 100 parts by mass of the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer. When the content of the (E) glass fiber in the thermosetting resin composition is 5 parts by mass or more, the mechanical properties of the cured product obtained from the thermosetting resin composition are better. When the content of the (E) glass fiber in the thermosetting resin composition is 200 parts by mass or less, the (E) glass fiber is more uniformly dispersed in the thermosetting resin composition, allowing for the production of a homogeneous cured product.

[0093] [(F) Inorganic Filler] As the (F) inorganic filler, any particulate material known in the technical field of the present invention other than magnesium hydroxide and magnesium oxide can be used. The use of the (F) inorganic filler can reduce the molding shrinkage of the molded article, improve workability by adjusting the viscosity of the thermosetting resin composition, or improve the strength of the molded article.

[0094] Examples of (F) inorganic fillers include calcium carbonate, silica, aluminum oxide, aluminum hydroxide, barium sulfate, calcium sulfate, calcium oxide, calcium hydroxide, wollastonite, clay, kaolin, mica, gypsum, silicic anhydride, and glass powder. Calcium carbonate, aluminum oxide, and aluminum hydroxide are preferred because they are inexpensive. (F) inorganic fillers may be used alone or in combination of two or more.

[0095] The average particle size of the (F) inorganic filler is preferably 1 to 100 μm, more preferably 1 to 60 μm, and even more preferably 1 to 50 μm. If the average particle size of the (F) inorganic filler is 1 μm or more, particle aggregation can be suppressed. On the other hand, if the average particle size of the (F) inorganic filler is 100 μm or less, the moldability of the thermosetting resin composition is good.

[0096] In this specification, the term "average particle size" refers to the 50% particle size (D50) in the volume-based cumulative particle size distribution measured using a laser diffraction / scattering particle size distribution analyzer (Microtrac Bell Co., Ltd., FRA).

[0097] The shape of the inorganic filler (F) is not particularly limited, and examples thereof include substantially spherical, ellipsoidal, scaly, and amorphous shapes.

[0098] The content of the (F) inorganic filler in the thermosetting resin composition is preferably 50 parts by mass or more, more preferably 100 parts by mass or more, and even more preferably 200 parts by mass or more, based on 100 parts by mass of the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer. The content of the (F) inorganic filler in the thermosetting resin composition is preferably 1000 parts by mass or less, more preferably 800 parts by mass or less, and even more preferably 600 parts by mass or less, based on 100 parts by mass of the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer. If the content of the (F) inorganic filler in the thermosetting resin composition is 50 parts by mass or more, the mechanical properties of the cured product are better. If the content of the (F) inorganic filler in the thermosetting resin composition is 1000 parts by mass or less, the (F) inorganic filler is more uniformly dispersed in the thermosetting resin composition, and a homogeneous cured product can be produced.

[0099] [(G) Thickener] The (G) thickener is one or more selected from the group consisting of styrene-butadiene rubber (SBR), styrene-butadiene-styrene rubber (SBS), and styrene-ethylene-butadiene-styrene rubber (SEBS). By using a specific amount of the (G) thickener, a thermosetting resin composition with excellent filling properties during molding can be obtained, thereby resulting in a molded stator without chips. By using a specific amount of the (G) thickener, the fluidity of the thermosetting resin composition during molding can be adjusted to a desired range, resulting in a molded stator covered with a molding material that has a good appearance and is free of cracks. The use of magnesium oxide or magnesium hydroxide can also adjust the fluidity of the thermosetting resin composition during molding to a desired range. However, because the fluidity fluctuates over time, it is difficult to ensure a constant usable life after preparing the thermosetting resin composition. As a result, there is a tendency for problems such as the inability to control filling properties during molding, making it impossible to obtain a molded stator covered with a molding material that has a good appearance. Furthermore, the use of magnesium oxide or magnesium hydroxide tends to increase the shrinkage rate of the cured product, which tends to result in problems such as the inability to obtain a molded stator covered with a molding material that is free of cracks and has a good appearance.

[0100] The form of the thickener (G) is not particularly limited, and examples thereof include crumbs and powders.

[0101] The content of the (G) thickener in the thermosetting resin composition is 0.8 parts by mass or more, preferably 1.5 parts by mass or more, and more preferably 3 parts by mass or more, based on 100 parts by mass of the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer. The content of the (G) thickener in the thermosetting resin composition is 9 parts by mass or less, preferably 8 parts by mass or less, and more preferably 7 parts by mass or less, based on 100 parts by mass of the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer. When the content of the (G) thickener in the thermosetting resin composition is within the above range, the fluidity of the thermosetting resin composition can be adjusted to the desired range, resulting in good filling properties during molding. In addition, a molded stator covered with a molding material having a good appearance and no cracks can be obtained.

[0102] [(H) Other Low-Shrinkage Agents] The thermosetting resin composition may contain (H) other low-shrinkage agents other than the saturated polyester resin, as needed. The (H) other low-shrinkage agents are not particularly limited, and those known in the technical field of the present invention can be used. As the (H) other low-shrinkage agents, thermoplastic resins are preferred. Examples of the (H) other low-shrinkage agents include polystyrene, polyethylene, polymethyl methacrylate, polyvinyl acetate, polycaprolactone, etc. Among these, polystyrene is preferred from the viewpoint of reducing the shrinkage rate of the cured product. The (H) other low-shrinkage agents may be used alone or in combination of two or more.

[0103] The content of the (H) other low-shrinkage agent in the thermosetting resin composition may be 1 part by mass or more, 3 parts by mass or more, or 5 parts by mass or more, based on 100 parts by mass of the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer. The content of the (H) other low-shrinkage agent in the thermosetting resin composition may be 40 parts by mass or less, 30 parts by mass or less, or 20 parts by mass or less, based on 100 parts by mass of the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer. When the content of the (H) other low-shrinkage agent in the thermosetting resin composition is 1 part by mass or more, the shrinkage rate of the cured product is small, and the desired dimensional accuracy can be obtained in the molded product. When the content of the (H) other low-shrinkage agent in the thermosetting resin composition is 40 parts by mass or less, the moldability of the thermosetting resin composition and the mechanical properties of the cured product are better.

[0104] [(I) Mold Release Agent] The thermosetting resin composition may contain a (I) mold release agent as needed. The (I) mold release agent is not particularly limited, and any agent known in the technical field of the present invention can be used. Examples of the (I) mold release agent include stearic acid, oleic acid, zinc stearate, calcium stearate, aluminum stearate, magnesium stearate, stearic acid amide, oleic acid amide, silicone oil, and synthetic wax. The (I) mold release agent may be used alone or in combination of two or more types.

[0105] When (I) mold release agent is used, its content is preferably 1 to 40 parts by mass, more preferably 5 to 30 parts by mass, and even more preferably 8 to 20 parts by mass, per 100 parts by mass of (B) thermosetting resin. If the content of (I) mold release agent is 1 part by mass or more, the releasability of the cured product during molding is good, resulting in good product productivity. On the other hand, if the content of (I) mold release agent is 40 parts by mass or less, excess mold release agent will not contaminate the surface of the cured product, and a cured product with good appearance can be obtained.

[0106] [Other Additives] In addition to the above components, the thermosetting resin composition may contain components known in the technical field of the present invention, such as viscosity reducers, colorants, polymerization inhibitors, and molding aids, within the range that does not impair the effects of the present invention.

[0107] A colorant is used when coloring a cured product. Examples of colorants include various dyes, inorganic pigments, and organic pigments. The colorants may be used alone or in combination of two or more. The content of the colorant can be appropriately adjusted depending on the degree of coloration desired in the cured product.

[0108] Examples of polymerization inhibitors include hydroquinone, trimethylhydroquinone, p-benzoquinone, naphthoquinone, t-butylhydroquinone, catechol, p-t-butylcatechol, and 2,6-di-t-butyl-4-methylphenol. The polymerization inhibitors may be used alone or in combination. The content of the polymerization inhibitor can be appropriately adjusted depending on the storage environment, storage period, curing conditions, etc. of the thermosetting resin composition.

[0109] <Method for Producing Thermosetting Resin Composition> The thermosetting resin composition can be produced by mixing (A) saturated polyester resin, (B) thermosetting resin, (C) ethylenically unsaturated monomer, (D) thermal polymerization initiator, (E) glass fiber, (F) inorganic filler, and (G) thickener, and, as necessary, optional components such as (H) other low-shrinkage agents, (I) mold release agents, and other additives.

[0110] An example of a mixing method is kneading. The kneading method is not particularly limited, and for example, a kneader, a disperser, a planetary mixer, etc. can be used. The kneading temperature is preferably 5°C to 50°C, more preferably 10°C to 40°C.

[0111] The order in which the components are mixed when producing a thermosetting resin composition is not particularly limited. For example, mixing the (B) thermosetting resin with part or all of the (C) ethylenically unsaturated monomer and then mixing the other components is preferred, as this makes it easier to obtain a thermosetting resin composition in which the components are sufficiently dispersed or uniformly mixed. At least a portion of the (C) ethylenically unsaturated monomer may be premixed with the (B) thermosetting resin so that it acts as a solvent, dispersion medium, etc. At least a portion of the (C) ethylenically unsaturated monomer may be premixed with the (G) thickener so that it acts as a solvent, dispersion medium, etc.

[0112] <Method for producing molding material> The molding material can be produced by heating and curing a thermosetting resin composition. The conditions for curing the thermosetting resin composition can be appropriately set depending on the materials used and the decomposition temperature of the (D) thermal polymerization initiator, etc. An example of preferred conditions is a temperature of 120 to 180°C, more preferably a temperature of 120 to 160°C, and a curing time of 1 to 30 minutes.

[0113] <Method for Manufacturing a Molded Stator> A molded stator can be manufactured, for example, by injecting a thermosetting resin composition into a mold in which a stator is placed in a predetermined position, and then heating the composition. The molding method is not particularly limited, and includes methods commonly used in the technical field of the present invention, such as transfer molding and injection molding.

[0114] More specific methods for manufacturing a molded stator include, for example, a method in which a mold is opened, a thermosetting resin composition is poured into the mold with a stator placed therein, and cured; and a method in which a thermosetting resin composition is injected from the outside into a closed mold with a stator placed therein through a hole in the mold, such as a sprue, under reduced pressure inside the mold or with pressure applied from the outside, as in injection molding, and cured. The conditions for curing the thermosetting resin composition in the mold can be set appropriately depending on the material used. An example of a preferred condition is a temperature of 120 to 180°C, more preferably a temperature of 120 to 160°C, and a curing time of 1 to 30 minutes.

[0115] The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0116] The synthesis examples of the saturated polyester resin (A) used in the examples and the saturated polyester resin (cA) used in the comparative examples are shown below.

[0117] The following raw materials were used: Diol: Diethylene glycol (Fujifilm Wako Pure Chemical Corporation) Dipropylene glycol (Fujifilm Wako Pure Chemical Corporation) Saturated polybasic acid: Isophthalic acid (Fujifilm Wako Pure Chemical Corporation) Adipic acid (Fujifilm Wako Pure Chemical Corporation)

[0118] Synthesis Example 1: 50 mol parts of isophthalic acid, 60 mol parts of diethylene glycol, and 40 mol parts of dipropylene glycol were charged into a four-neck flask equipped with a thermometer, a stirrer, an inert gas inlet, and a reflux condenser. The temperature was raised to 210°C while stirring under a nitrogen gas stream, and an esterification reaction was carried out. When the acid value of the reaction solution reached 10 KOH mg / g or less, 50 mol parts of adipic acid was added, and the esterification reaction was continued to obtain a saturated polyester resin. Thereafter, when the acid value of the reaction solution reached 10 KOH mg / g or less, styrene monomer was added in an amount of 40% by mass relative to the total of the saturated polyester resin and the styrene monomer, to obtain a mixture of saturated polyester resin and styrene. The resulting saturated polyester resin had a weight average molecular weight (Mw) of 10,000. The weight average molecular weight (Mw) of the block (X) of the resulting saturated polyester resin was 4,000.

[0119]

[0120] [Synthesis Examples 2 to 5] Mixtures of saturated polyester resin and styrene were obtained in the same manner as in Synthesis Example 1, except for using the compositions shown in Table 1. The weight average molecular weight (Mw) of the saturated polyester resin and the weight average molecular weight (Mw) of the block (X) of the saturated polyester resin are shown in Table 1.

[0121] Comparative Synthesis Example 1 A mixture of saturated polyester resin and styrene was obtained in the same manner as in Synthesis Example 1, except that the components shown in Table 1 were charged and reacted all at once from the beginning. The weight average molecular weight (Mw) of the saturated polyester resin is shown in Table 1.

[0122] An example of the synthesis of the thermosetting resin (B) is shown below.

[0123] The following raw materials were used: Diol: Propylene glycol (FUJIFILM Wako Pure Chemical Corporation) Neopentyl glycol (FUJIFILM Wako Pure Chemical Corporation) Hydrogenated bisphenol A (FUJIFILM Wako Chemical Co., Ltd.) Unsaturated polybasic acid: Maleic anhydride (FUJIFILM Wako Pure Chemical Corporation) Fumaric acid (FUJIFILM Wako Pure Chemical Corporation) Saturated polybasic acid: Isophthalic acid (FUJIFILM Wako Pure Chemical Corporation)

[0124] [Synthesis Example 6] (B) Synthesis of Thermosetting Resin 100 mol parts of maleic anhydride, 60 mol parts of propylene glycol, and 40 mol parts of neopentyl glycol were charged into a four-neck flask equipped with a thermometer, a stirrer, an inert gas inlet, and a reflux condenser. The mixture was heated to 210°C with stirring under a nitrogen gas flow to carry out an esterification reaction, yielding an unsaturated polyester resin. Styrene monomer was then added in an amount of 40% by mass relative to the total of the unsaturated polyester resin and the styrene monomer, yielding a mixture of unsaturated polyester resin and styrene. The resulting unsaturated polyester resin had an unsaturation degree of 100 mol% and a weight-average molecular weight (Mw) of 20,000.

[0125]

[0126] Synthesis Examples 7 to 10 Mixtures of unsaturated polyester resin and styrene were obtained in the same manner as in Synthesis Example 6, except for using the compositions shown in Table 2. The weight average molecular weights (Mw) of the unsaturated polyester resins are shown in Table 2.

[0127] The other components used were as follows:

[0128] (C) Ethylenically unsaturated monomer: Styrene (Idemitsu Kosan Co., Ltd.)

[0129] (D) Thermal polymerization initiator: Perhexyl I (t-hexylperoxyisopropyl carbonate, NOF Corporation)

[0130] (E) Glass fiber: Chopped strand ECS-03B173 / P9 (glass chopped, fiber diameter 13 μm, fiber length 3.0 mm, Nippon Electric Glass Co., Ltd.)

[0131] (F) Inorganic filler: Aluminum hydroxide (average particle size 7 μm, Nippon Light Metal Co., Ltd.)

[0132] (G) Thickener: Styrene-butadiene rubber (Asahi Kasei Corporation) Magnesium oxide (Kanto Chemical Co., Ltd.)

[0133] (H) Other low shrinkage agents: Polystyrene (PS MS-200, Sekisui Plastics Co., Ltd.)

[0134] Example 1 (Preparation of thermosetting resin composition) 28 parts by mass of a mixture of (A) saturated polyester resin and (C) the ethylenically unsaturated monomer obtained in Synthesis Example 1 with styrene (17 parts by mass of saturated polyester resin, 11 parts by mass of styrene), (B) 53 parts by mass of a mixture of (C) the ethylenically unsaturated monomer obtained in Synthesis Example 6 with styrene (32 parts by mass of unsaturated polyester resin, 21 parts by mass of styrene), an additional 36 parts by mass of styrene as the (C) ethylenically unsaturated monomer, (D) 9 parts by mass of Perhexyl I as a thermal polymerization initiator, (E) 85 parts by mass of chopped strand ECS-03B173 / P9 glass fiber, (F) 414 parts by mass of aluminum hydroxide as an inorganic filler, (G) 6 parts by mass of styrene-butadiene rubber as a thickener, and (H) 16 parts by mass of polystyrene as an additional low-shrinkage agent were charged into a twin-arm kneader and kneaded for 30 minutes at 30°C to produce a thermosetting resin composition.

[0135] (Initial Flow) Using a thermosetting resin composition immediately after kneading, the flowability was evaluated by measuring the flow length, i.e., the spiral flow value, in a spiral flow test. Specifically, a spiral flow mold with a trapezoidal cross section (upper base 6.5 mm, lower base 8 mm, height 2 mm) was attached to a 50-ton transfer molding machine, and the spiral flow value (cm) of the thermosetting resin composition was measured under the following conditions: charge amount 50 g, molding temperature 140°C, and molding pressure 5 MPa. The results are shown in Table 3.

[0136] (Flowability after Change Over Time) Using thermosetting resin compositions that had been kneaded and then stored in a 20°C environment for 30 days, the flowability was evaluated by measuring the flow length, i.e., the spiral flow value, in a spiral flow test. Specifically, a spiral flow mold with a trapezoidal cross section (upper base 6.5 mm, lower base 8 mm, height 2 mm) was attached to a 50-ton transfer molding machine, and the spiral flow value (cm) of the thermosetting resin composition was measured under the following conditions: charge amount 50 g, molding temperature 140°C, and molding pressure 5 MPa. The results are shown in Table 3.

[0137] (Molding shrinkage) According to JIS K-6911 (2006) 5.7, a disk-shaped test specimen (φ90 mm × 11 mm) was obtained by compression molding using a compression molding machine (Technomarushi Co., Ltd.) under conditions of a molding temperature of 120 ° C, a molding pressure of 5 MPa, and a molding time of 3 minutes, and the molding shrinkage was calculated. The test specimen was prepared using a thermosetting resin composition immediately after kneading. The results are shown in Table 3.

[0138] (Preparation of molded stator) A stator was placed in a mold, and a thermosetting resin composition was injected and molded at a molding temperature of 130°C, a molding pressure of 5 MPa, and a molding time of 5 minutes to obtain a molded stator. The filling property during molding and the appearance of the molded stator in terms of cracks were evaluated according to the following criteria. The results are shown in Table 3.

[0139] <<Initial Filling Property During Molding of Molded Stator>> The appearance of a molded stator produced using the thermosetting resin composition immediately after kneading was visually observed, and a state in which the cured product of the thermosetting resin composition was completely filled along the shape of the mold without any defects was rated as good, and a state in which there were some defects was rated as poor.

[0140] <<Filling property during molding of molded stator after change over time>> The appearance of a molded stator produced using a thermosetting resin composition that had been kneaded and then stored in an environment of 20°C for 30 days was visually observed, and a state in which the cured product of the thermosetting resin composition was completely filled along the mold shape without any defects was rated as good, and a state in which there were partial defects was rated as poor.

[0141] <<Initial Appearance of Molded Stator from the Viewpoint of Cracks>> The appearance of a molded stator produced using a thermosetting resin composition immediately after kneading was visually observed, and those with no cracks were rated as good, and those with cracks were rated as poor.

[0142] <<Appearance of Molded Stator from the Viewpoint of Cracks After Change Over Time>> The appearance of a molded stator produced using a thermosetting resin composition that had been kneaded and then stored in an environment of 20°C for 30 days was visually observed, and a molded stator with no cracks was rated as good, and a molded stator with cracks was rated as poor.

[0143] (Heat Cycle Test) A heat cycle test was conducted on a molded stator produced using the thermosetting resin composition immediately after kneading using a heat cycle tester (testing machine: TSA-71L-A, manufactured in 2010, Espec Corporation) in the atmosphere, with one cycle consisting of 20 minutes at -40°C and 20 minutes at 140°C. The test was conducted for 250 cycles, and the appearance of the molded stator was visually observed every 50 cycles to check for the occurrence of cracks. The maximum number of cycles in which no cracks occurred is shown in Table 3.

[0144]

[0145] Examples 2 to 9, Comparative Examples 1 to 5 Thermosetting resin compositions were prepared in the same manner as in Example 1, except that the types and compositions of raw materials were changed as shown in Table 3. Then, various evaluations were carried out in the same manner as in Example 1. The results are shown in Table 3. Note that a heat cycle test was not carried out for Comparative Examples 1 to 5.

[0146] In Examples 1 to 9, the fluidity of the thermosetting resin composition could be adjusted to the desired range, the filling properties during molding were good, and molded stators covered with a molding material with a good appearance free of chips and cracks were obtained. On the other hand, in Comparative Example 1, which did not use a thickener, and Comparative Example 2, which contained an insufficient amount of styrene-butadiene rubber, the filling properties were poor, resulting in partial defects in the molded stator. In Comparative Example 3, which contained an excessive amount of styrene-butadiene rubber, the fluidity and filling properties could not be adjusted to the desired range, resulting in partial defects in the molded stator. In Comparative Example 3, cracks occurred in the molding material, and a molded stator with a good appearance could not be obtained. In Comparative Example 4, in which magnesium oxide was used instead of styrene-butadiene rubber, cracks occurred in the molding material, and a molded stator with a good appearance could not be obtained. In addition, fluctuations in fluidity over time could not be controlled, and filling properties deteriorated after aging. In Comparative Example 5, in which no (A) saturated polyester resin was used, cracks occurred in the molding material, and a molded stator with a good appearance could not be obtained.

[0147] REFERENCE SIGNS LIST 10 Motor 11 Stator 12 Stator core 13 Coil 14 Molding material 15 Rotor 16 Magnet 17 Rotating shaft 18 Rotating body 19 Bearing

Claims

1. A molded stator comprising: a stator having a stator core and a coil wound around the stator core; and a molding material covering the stator, wherein the molding material is a cured product of a thermosetting resin composition containing (A) saturated polyester resin, (B) thermosetting resin, (C) ethylenically unsaturated monomer, (D) thermal polymerization initiator, (E) glass fiber, (F) inorganic filler, and (G) thickener, wherein the (G) thickener is one or more selected from the group consisting of styrene-butadiene rubber (SBR), styrene-butadiene-styrene rubber (SBS), and styrene-ethylene-butadiene-styrene rubber (SEBS), and the content of the (G) thickener in the thermosetting resin composition is 0.8 to 9 parts by mass, where the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer is 100 parts by mass. a saturated polyester resin (A) comprising a block (X) which is a polycondensate of a diol and a saturated polybasic acid or an acid anhydride thereof, and a saturated aliphatic polybasic acid; a saturated polyester resin (A) comprising a block (X) which is a polycondensate of a diol and a saturated aromatic polybasic acid or an acid anhydride thereof, and a block (Y) which is a polycondensate of a diol and a saturated aliphatic polybasic acid, and a weight average molecular weight of the block (X) is 3,000 to 5,000; 2. The molded stator according to claim 1, wherein the weight average molecular weight of the saturated polyester resin (A) is 9,500 to 13,500.

3. A molded stator according to claim 1 or 2, wherein the aromatic saturated polybasic acid constituting the block (X) is at least one selected from the group consisting of isophthalic acid and terephthalic acid.

4. A molded stator according to claim 1 or 2, wherein the aliphatic saturated polybasic acid constituting the block (Y) is at least one selected from the group consisting of succinic acid, adipic acid, and sebacic acid.

5. A molded stator according to claim 1, wherein the weight average molecular weight of said thermosetting resin (B) is 10,000 to 50,000.

6. The molded stator according to claim 1, wherein the thermosetting resin (B) comprises an unsaturated polyester resin, the unsaturated polyester resin being a polycondensate of a diol, an unsaturated polybasic acid, and optionally a saturated polybasic acid, and the diol contains propylene glycol and neopentyl glycol.

7. The molded stator according to claim 1, wherein the thermosetting resin composition contains: 5 to 30 parts by mass of the (A) saturated polyester resin; 5 to 80 parts by mass of the (B) thermosetting resin; 20 to 95 parts by mass of the (C) ethylenically unsaturated monomer; 0.5 to 20 parts by mass of the (D) thermal polymerization initiator; 5 to 200 parts by mass of the (E) glass fiber; and 50 to 1000 parts by mass of the (F) inorganic filler, assuming that the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer is 100 parts by mass.

8. A motor comprising: a molded stator according to any one of claims 1, 2, and 5 to 7; a rotating shaft extending in the axial direction; a rotor including a magnetic component extending in the axial direction and fixed to the rotating shaft; a rotor positioned inside the stator; and a bearing supporting the rotor for free rotation.

9. A composition comprising (A) a saturated polyester resin, (B) a thermosetting resin, (C) an ethylenically unsaturated monomer, (D) a thermal polymerization initiator, (E) glass fiber, (F) an inorganic filler, and (G) a thickener, wherein the (G) thickener is one or more selected from the group consisting of styrene-butadiene rubber (SBR), styrene-butadiene-styrene rubber (SBS), and styrene-ethylene-butadiene-styrene rubber (SEBS), and the content of the (G) thickener is 0.8 to 9 parts by mass, relative to 100 parts by mass of the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer, and the (A) saturated polyester resin is a polycondensate of a diol and a saturated polybasic acid, and the saturated polybasic acid comprises an aromatic saturated polybasic acid or an acid anhydride thereof, and an aliphatic saturated polybasic acid, a thermosetting resin composition, wherein the saturated polyester resin (A) contains a block (X) which is a polycondensate of a diol and a saturated aromatic polybasic acid or an acid anhydride thereof, and a block (Y) which is a polycondensate of a diol and a saturated aliphatic polybasic acid, and wherein the weight average molecular weight of the block (X) is 3,000 to 5,000; 10. The thermosetting resin composition according to claim 9, wherein the weight average molecular weight of the saturated polyester resin (A) is 9,500 to 13,500.

11. The thermosetting resin composition according to claim 9 or 10, comprising: 5 to 30 parts by mass of the (A) saturated polyester resin; 5 to 80 parts by mass of the (B) thermosetting resin; 20 to 95 parts by mass of the (C) ethylenically unsaturated monomer; 0.5 to 20 parts by mass of the (D) thermal polymerization initiator; 5 to 200 parts by mass of the (E) glass fiber; and 50 to 1000 parts by mass of the (F) inorganic filler, where the total amount of the (B) thermosetting resin and the (C) ethylenically unsaturated monomer is 100 parts by mass.

12. A molding material which is a cured product of the thermosetting resin composition according to claim 9 or 10.

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