Unsaturated polyester resin composition, molding material and molded product

Abstract

The unsaturated polyester resin composition comprises an unsaturated polyester, a vinyl ester, a polymerizable monomer, and aluminum hydroxide. The vinyl ester is a reaction product of an epoxy resin and an unsaturated monobasic acid. The proportion of the vinyl ester relative to the unsaturated polyester is a prescribed proportion. The proportion of the aluminum hydroxide relative to the vinyl ester is a prescribed proportion.

Description

Technical Field

[0001] The present invention relates to an unsaturated polyester resin composition, a molding material and a molded article, and more particularly to an unsaturated polyester resin composition, a molding material comprising the unsaturated polyester resin composition, and a molded article comprising a cured product of the molding material. Background Art

[0002] Conventionally, molded articles formed of molding materials containing unsaturated polyester resins (particularly SMC (sheet molding compound)) have been used in various fields because of their excellent appearance, mechanical properties, water resistance, corrosion resistance, etc.

[0003] As such a molding material, for example, a molding material containing a crystalline unsaturated polyester resin, a vinyl ester resin, SOFTON 1200 (calcium carbonate) as a filler, and glass fiber has been proposed (for example, see Example 1 of Patent Document 1 listed below).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 8-295714 Summary of the invention

[0007] Problems to be solved by the invention

[0008] However, since the molding material of Patent Document 1 contains calcium carbonate, a molded product obtained using the molding material has a disadvantage of being poor in flame retardancy.

[0009] From the viewpoint of improving flame retardancy, it has been studied to add aluminum hydroxide to the molding material. However, when aluminum hydroxide is added, there is a disadvantage that the mechanical properties of the molded product are deteriorated.

[0010] In addition, such molded products may require low shrinkage in order to reduce warping and deformation.

[0011] An object of the present invention is to provide an unsaturated polyester resin composition for obtaining a molded product having excellent flame retardancy and mechanical strength and low shrinkage, a molding material comprising the unsaturated polyester resin composition, and a molded product comprising a cured product of the molding material.

[0012] Means for solving problems

[0013] The present invention [1] is an unsaturated polyester resin composition, which comprises an unsaturated polyester, a vinyl ester, a polymerizable monomer, and aluminum hydroxide, wherein the vinyl ester is a reaction product of an epoxy resin and an unsaturated monobasic acid, the mixing ratio of the vinyl ester is 5 parts by mass or more and 20 parts by mass or less relative to 100 parts by mass of the unsaturated polyester, and the mixing ratio of the aluminum hydroxide to the vinyl ester (aluminum hydroxide / vinyl ester) is 22 or more and 45 or less.

[0014] The present invention [2] comprises the unsaturated polyester resin composition described in the above [1], wherein the epoxy resin is a bisphenol epoxy resin and the epoxy equivalent of the epoxy resin is 250 g / eq or more and 350 g / eq or less.

[0015] The present invention [3] comprises the unsaturated polyester resin composition described in the above [2], wherein the epoxy resin is a bisphenol A type epoxy resin.

[0016] The present invention [4] comprises the unsaturated polyester resin composition according to any one of [1] to [3], further comprising a flame retardant.

[0017] The present invention [5] comprises a molding material comprising the unsaturated polyester resin composition according to [1] to [4] above, and reinforcing fibers.

[0018] The present invention [6] includes a molded article comprising a cured product of the molding material described in [5] above.

[0019] Effects of the Invention

[0020] In the unsaturated polyester resin composition of the present invention, the blending ratio of the vinyl ester to the unsaturated polyester is a predetermined ratio.

[0021] Therefore, a molded article obtained using the unsaturated polyester resin composition has excellent mechanical properties (bending properties, tensile properties) and low shrinkage.

[0022] In addition, in the unsaturated polyester resin composition, the mixing ratio of aluminum hydroxide to vinyl ester is a predetermined ratio.

[0023] Therefore, a molded article obtained using the unsaturated polyester resin composition has excellent flame retardancy and excellent mechanical properties (flexural properties and tensile properties).

[0024] The molding material of the present invention contains the unsaturated polyester resin composition of the present invention. Therefore, a molded article obtained using the molding material has excellent flame retardancy and mechanical strength (bending properties, tensile properties) and has low shrinkage.

[0025] The molded article of the present invention includes a cured product of the molding material of the present invention, and therefore has excellent flame retardancy and mechanical strength (bending properties, tensile properties), and has low shrinkage. DETAILED DESCRIPTION

[0026] The unsaturated polyester resin composition of the present invention comprises an unsaturated polyester, a vinyl ester, a polymerizable monomer, and aluminum hydroxide.

[0027] Unsaturated polyesters are the polymerization products of polyacids and polyols.

[0028] The polybasic acid includes a polybasic acid having an ethylenically unsaturated double bond (hereinafter referred to as a polybasic acid containing an ethylenically unsaturated bond) as an essential component and a polybasic acid not having an ethylenically unsaturated double bond (hereinafter referred to as a polybasic acid not containing an ethylenically unsaturated bond) as an optional component.

[0029] Examples of the polybasic acid containing an ethylenically unsaturated bond include ethylenically unsaturated aliphatic dibasic acids such as maleic acid, fumaric acid, itaconic acid, and dihydromuconic acid, halides of these acids, and alkyl esters of these acids.

[0030] In addition, the polybasic acid containing an ethylenically unsaturated bond includes an acid anhydride derived from the above-mentioned ethylenically unsaturated aliphatic dibasic acid, for example, maleic anhydride.

[0031] Preferred examples of the ethylenically unsaturated bond-containing polybasic acid include maleic anhydride and fumaric acid.

[0032] Examples of the polybasic acid not containing an ethylenically unsaturated bond include saturated aliphatic polybasic acids, saturated alicyclic polybasic acids, aromatic polybasic acids, halides of these acids, and alkyl esters of these acids.

[0033] Examples of the saturated aliphatic polybasic acid include saturated aliphatic dibasic acids such as oxalic acid, malonic acid, succinic acid, methylsuccinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylsuccinic acid, hexylsuccinic acid, glutaric acid, 2-methylglutaric acid, 3-methylglutaric acid, 2,2-dimethylglutaric acid, 3,3-dimethylsuccinic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid.

[0034] In addition, the saturated aliphatic polybasic acid includes anhydrides derived from the above-mentioned saturated aliphatic dibasic acid, such as oxalic anhydride and succinic anhydride.

[0035] Examples of the saturated alicyclic polybasic acid include saturated alicyclic dibasic acids such as chlorodiacid (HET acid), 1,2-hexahydrophthalic acid, 1,1-cyclobutanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid (cis- or trans-1,4-cyclohexanedicarboxylic acid or a mixture thereof), and dimer acid.

[0036] The saturated alicyclic polybasic acid includes anhydrides derived from the above-mentioned saturated alicyclic dibasic acids, such as chlorohydric acid anhydride.

[0037] Examples of the aromatic polybasic acid include aromatic dibasic acids such as phthalic acid (phthalic acid, isophthalic acid, terephthalic acid), trimellitic acid, and pyromellitic acid.

[0038] In addition, the aromatic polybasic acid includes an acid anhydride derived from the above-mentioned aromatic dibasic acid, for example, phthalic anhydride and the like.

[0039] As the polybasic acid not containing an ethylenically unsaturated bond, preferably an aromatic polybasic acid is used, more preferably an aromatic dibasic acid is used, further preferably phthalic acid is used, and particularly preferably isophthalic acid is used.

[0040] The polybasic acid can be used alone or in combination of two or more.

[0041] The polybasic acid preferably contains only polybasic acids containing ethylenically unsaturated bonds.

[0042] Examples of the polyol include ethylene glycol, propylene glycol (1,2- or 1,3-propylene glycol or a mixture thereof), butanediol (1,2- or 1,3- or 1,4-butylene glycol or a mixture thereof), 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2,2-trimethylpentanediol, 3,3-dihydroxymethylheptane and other alkanediols; aliphatic diols such as ether diols such as diethylene glycol, triethylene glycol, and dipropylene glycol; cyclohexanediol (1,2- or 1,3- or 1,4-cyclohexanediol or a mixture thereof), cyclohexanedimethanol (1,2- or 1,3- or 1,4-cyclohexanediol) and the like. The preferred alkylene glycols include 1,2-, 1,3-, or 1,4-cyclohexanediethanol and 1,4-cyclohexanediethanol and 1,2-, 1,3-, or 1,4-cyclohexanediethanol and 1,4-cyclohexanediethanol and 1,2-, 1,3-, or 1,4-cyclohexanediethanol and 1,4-cyclohexanediethanol and 1,2-, 1,3-, or 1,4-cyclohexanediethanol and 1,4-cyclohexanediethanol and 1,2-, 1,3-, or 1,4-cyclohexanediethanol and 1,4-cyclohexanediethanol and 1,4-cyclohexanediethanol and 1,4-cyclohexanediethanol and 1,4-cyclohexanediethanol and 1,4-cyclohexanediethanol and 1,4-cyclohexanediethanol and 1,4-cyclohexanediethanol and 1,4-cyclohexanediethanol and 1,4-cyclohexanediethanol and 1,4-cyclohexanediethanol and 1,4-cyclohexanediol ...

[0043] The polyhydric alcohol may be used alone or in combination of two or more kinds. Preferably, the polyhydric alcohol contains propylene glycol and neopentyl glycol.

[0044] Unsaturated polyesters can be obtained by polycondensation (condensation polymerization) of polyacids and polyols.

[0045] In order to polycondense the polybasic acid and the polyol (condensation polymerization), the polyol is mixed so that the equivalent ratio of the polyol to the polybasic acid (hydroxyl group of the polyol / carboxyl group of the polybasic acid) is, for example, 0.9 or more, preferably 0.95 or more, and for example, 1.2 or less, preferably 1.1 or less, and stirred under normal pressure and nitrogen atmosphere.

[0046] The reaction temperature is, for example, 150° C. or higher, preferably 190° C. or higher, and, for example, 250° C. or lower, preferably 230° C. or lower.

[0047] The reaction time is, for example, 8 hours or longer, and, for example, 30 hours or shorter.

[0048] In the above-mentioned reaction, a known solvent and a known catalyst may be added as necessary.

[0049] Thus, an unsaturated polyester can be obtained.

[0050] The acid value of the unsaturated polyester (measurement method: in accordance with JIS K6901 (2008)) is, for example, 20 mgKOH / g or more, preferably 25 mgKOH / g or more, and, for example, less than 40 mgKOH / g, preferably 30 mgKOH / g or less.

[0051] The weight average molecular weight of the unsaturated polyester is, for example, 4000 or more, preferably 6000 or more, and, for example, 25000 or less, preferably 20000 or less.

[0052] In addition, the weight average molecular weight is a weight average molecular weight based on GPC (gel permeation chromatography) in terms of polystyrene, and can be obtained by subjecting the unsaturated polyester to GPC measurement.

[0053] The blending ratio of the unsaturated polyester is, for example, 30 parts by mass or more, and for example, 60 parts by mass or less, relative to 100 parts by mass of the total amount of the unsaturated polyester, the vinyl ester, and the polymerizable monomer.

[0054] Vinyl esters are the reaction products of epoxy resins and unsaturated monobasic acids.

[0055] Examples of the epoxy resin include bisphenol epoxy resins and Novolac epoxy resins.

[0056] The bisphenol-type epoxy resin is a reaction product of a phenol component such as a bisphenol compound (eg, bisphenol A) and an epoxy component such as a bisphenol A-type epoxy compound.

[0057] The bisphenol epoxy resin is represented by the following general formula (1).

[0058] [Chemical formula 1]

[0059]

[0060] (Where Y 1 represents any one of -C(CH3)2-, -CH2-, -O-, -S-, and -(O=S=O)-, and n represents an integer of 0 to 5. )

[0061] Examples of such bisphenol epoxy resins include bisphenol A epoxy resins, bisphenol F epoxy resins, and bisphenol S epoxy resins, and preferably, bisphenol A epoxy resins are used.

[0062] When the bisphenol-type epoxy resin is a bisphenol A-type epoxy resin, the mechanical strength (tensile properties (tensile strength)) of a molded article (described later) obtained using the unsaturated polyester resin composition can be improved.

[0063] The epoxy equivalent of the bisphenol epoxy resin is, for example, 100 g / eq or more, preferably 250 g / eq or more, and, for example, 800 g / eq or less, preferably 400 g / eq or less, and more preferably 350 g / eq or less.

[0064] When the epoxy equivalent is not less than the above lower limit, the mechanical strength (bending properties, tensile properties) of a molded article (described later) obtained using the unsaturated polyester resin composition can be improved.

[0065] When the epoxy equivalent is not more than the upper limit, the mechanical strength (bending properties, tensile properties) of a molded article (described later) obtained using the unsaturated polyester resin composition can be improved.

[0066] The epoxy equivalent mentioned above when two bisphenol epoxy resins are used in combination is the epoxy equivalent of all bisphenol epoxy resins obtained by adding the epoxy equivalent of each bisphenol epoxy resin multiplied by the mass ratio of each bisphenol epoxy resin relative to the total amount of the bisphenol epoxy resin.

[0067] It should be noted that, in the above description, the bisphenol epoxy resin is a reaction product of a phenol component and an epoxy component, but it is not limited thereto, and the bisphenol epoxy resin may also be a reaction product of a phenol component and epichlorohydrin. Preferably, the bisphenol epoxy resin is a reaction product of a phenol component and an epoxy component.

[0068] Novolac-type epoxy resins are, for example, the reaction product of Novolac and epichlorohydrin.

[0069] Novolac type epoxy resin is represented by the following general formula (2).

[0070] [Chemical formula 2]

[0071]

[0072] (In the formula, R represents any one of -H and -CH3, and n represents an integer of 0 to 5.)

[0073] Examples of such Novolac epoxy resins include phenol Novolac epoxy resins (in the above general formula (2), R represents -H) and cresol Novolac epoxy resins (in the above general formula (2), R represents -CH3). Preferably, phenol Novolac epoxy resins are used.

[0074] The epoxy equivalent of the Novolac type epoxy resin is, for example, 100 g / eq or more, and for example, 800 g / eq or less, preferably 400 g / eq or less, more preferably 350 g / eq or less, and further preferably 200 g / eq or less.

[0075] In addition, a commercially available epoxy resin may be used. Alternatively, an epoxy resin obtained by chain-extending an epoxy resin with a phenol compound may be used.

[0076] As unsaturated monobasic acids, for example, monocarboxylic acids such as (meth)acrylic acid, crotonic acid, cinnamic acid, and sorbic acid, for example, reaction products of dibasic acid anhydrides and alcohols having at least one unsaturated group in the molecule, etc. It should be noted that (meth)acrylic- has the same meaning as methacrylic- and / or propylene-.

[0077] Examples of the dibasic acid anhydride include maleic anhydride, succinic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride.

[0078] Examples of the alcohol having an unsaturated group include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, pentaerythritol tri(meth)acrylate, and glycerol di(meth)acrylate.

[0079] The unsaturated monobasic acid may be used alone or in combination of two or more.

[0080] As the unsaturated monobasic acid, preferably, monocarboxylic acid is used, more preferably, (meth)acrylic acid is used, and further preferably, methacrylic acid is used.

[0081] Furthermore, in order to obtain vinyl esters, epoxy resins are reacted with unsaturated monobasic acids.

[0082] In the above reaction, the epoxy group of the epoxy resin undergoes an addition reaction with the unsaturated monobasic acid.

[0083] In the above reaction, the equivalent of the carboxyl group of the unsaturated monobasic acid to the epoxy group of the epoxy resin is, for example, 0.8 or more, preferably 1.0 or more, and for example, 1.5 or less, preferably 1.2 or less.

[0084] The catalyst includes, for example, amines such as triethylamine and benzyldimethylamine, ammonium salts such as tetramethylammonium chloride and triethylbenzylammonium chloride, imidazoles such as 2-ethyl-4-imidazole, amides, pyridines, phosphines such as triphenylphosphine, phosphonium salts such as tetraphenylphosphonium bromide and ethyltriphenylphosphonium bromide, sulfonium salts, sulfonic acids, and organic metal salts such as zinc octoate. Preferably, ammonium salts are used, and more preferably, triethylbenzylammonium chloride is used.

[0085] The mixing ratio of the catalyst relative to 100 parts by mass of the epoxy resin is, for example, 0.01 parts by mass or more, preferably 0.05 parts by mass or more, and, for example, 0.5 parts by mass or less, preferably 0.1 parts by mass or less.

[0086] In the above reaction, a polymerization inhibitor (described later) (preferably hydroquinone) may be added as necessary.

[0087] The mixing ratio of the polymerization inhibitor relative to 100 parts by mass of the epoxy resin is, for example, 0.01 parts by mass or more, preferably 0.05 parts by mass or more, and, for example, 0.5 parts by mass or less, preferably 0.1 parts by mass or less.

[0088] In addition, as reaction conditions, the reaction temperature is, for example, 80°C or more, preferably 100°C or more, and, for example, 150°C or less, preferably 130°C or less, and the reaction time is, for example, 1 hour or more, preferably 2 hours or more, and, for example, 10 hours or less.

[0089] It should be noted that the above reaction may be carried out after the above reaction between the phenol component and the epoxy component.

[0090] Thus, vinyl ester can be obtained.

[0091] The acid value of the vinyl ester (measurement method: in accordance with JIS K6901 (2008)) is, for example, 1 mgKOH / g or more and 20 mgKOH / g or less, and preferably 10 mgKOH / g or less.

[0092] The mixing ratio of the vinyl ester is, for example, 5 parts by mass or more, and for example, 20 parts by mass or less, or preferably 10 parts by mass or less, relative to 100 parts by mass of the total amount of the unsaturated polyester, the vinyl ester, and the polymerizable monomer.

[0093] The blending ratio of the vinyl ester is 5 parts by mass or more, preferably 10 parts by mass or more, and for example, 20 parts by mass or less, based on 100 parts by mass of the unsaturated polyester.

[0094] When the blending ratio of the vinyl ester is not less than the above lower limit, the mechanical strength (bending properties, tensile properties) of a molded article (described later) obtained using the unsaturated polyester resin composition can be improved.

[0095] On the other hand, when the blending ratio of the vinyl ester is less than the above lower limit, the mechanical strength (bending properties, tensile properties) of a molded article (described later) obtained using the unsaturated polyester resin composition decreases.

[0096] When the blending ratio of the vinyl ester is not more than the above upper limit, a molded article (described later) obtained using the unsaturated polyester resin composition has low shrinkage.

[0097] On the other hand, when the blending ratio of the vinyl ester exceeds the above upper limit, the low shrinkage property of a molded article (described later) obtained using the unsaturated polyester resin composition decreases.

[0098] The polymerizable monomer is a solvent for dissolving the unsaturated polyester and is a crosslinking monomer (reactive diluent) that can crosslink with the unsaturated polyester when the unsaturated polyester resin (described later) is cured. Examples thereof include styrene monomers such as styrene, α-methylstyrene, α-ethylstyrene, vinyltoluene, tert-butylstyrene, and chlorostyrene, and examples thereof include methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, isobutyl (meth)acrylate, and (meth)acrylate. ) 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, alkyl (meth)acrylates such as stearyl (meth)acrylate, allyl (meth)acrylates such as allyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, dicyclopentenyl (meth)acrylate, (meth) (Meth)acrylates containing a ring structure such as dicyclopentyl acrylate and dicyclopentenyloxyethyl (meth)acrylate, hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate, alkoxyalkyl (meth)acrylates such as 2-methoxyethyl (meth)acrylate and 2-ethoxyethyl (meth)acrylate, aminoalkyl (meth)acrylates such as dimethylaminoethyl (meth)acrylate and diethylaminoethyl (meth)acrylate, and chloride salts thereof, trifluoroethyl (meth)acrylate, (Meth)acrylate monomers such as fluoroalkyl (meth)acrylates such as heptadecafluorodecyl (meth)acrylate, polyfunctional (meth)acrylates such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate, and allyl monomers such as glycerol monoallyl ether, pentaerythritol diallyl ether, pentaerythritol monoallyl ether, and trimethylolpropane monoallyl ether are preferred, and styrene monomers are more preferred.

[0099] The polymerizable monomers may be used alone or in combination of two or more.

[0100] The blending ratio of the polymerizable monomer is, for example, 30 parts by mass or more, preferably 40 parts by mass or more, and for example, 60 parts by mass or less, relative to 100 parts by mass of the total amount of the unsaturated polyester, the vinyl ester, and the polymerizable monomer.

[0101] The mixing ratio of the polymerizable monomer relative to 100 parts by mass of the unsaturated polyester is, for example, 50 parts by mass or more, preferably 100 parts by mass or more, and, for example, 200 parts by mass or less, preferably 130 parts by mass or less.

[0102] The mixing ratio of the polymerizable monomer relative to 100 parts by mass of the vinyl ester is, for example, 500 parts by mass or more, preferably 700 parts by mass or more, and, for example, 1000 parts by mass or less, preferably 800 parts by mass or less.

[0103] Aluminum hydroxide is blended in order to impart flame retardancy, transparency, and depth to a molded article (described later) obtained using the unsaturated polyester resin composition.

[0104] The average particle size of aluminum hydroxide is, for example, 1 μm or more, and for example, 50 μm or less, and preferably 25 μm or less.

[0105] The average particle size of aluminum hydroxide can be determined by preparing a particle size distribution curve using a laser diffraction / scattering particle size distribution measuring apparatus and calculating a particle size corresponding to 50% by mass.

[0106] Aluminum hydroxides having different average particle sizes and aluminum hydroxides having different sodium oxide contents may be used alone or in combination of two or more kinds.

[0107] The mixing ratio of aluminum hydroxide relative to 100 parts by mass of the total amount of the unsaturated polyester, vinyl ester and polymerizable monomer is, for example, 100 parts by mass or more, preferably 150 parts by mass or more, and for example, 300 parts by mass or less, preferably 250 parts by mass or less.

[0108] The mixing ratio of aluminum hydroxide relative to 100 parts by mass of the unsaturated polyester is, for example, 300 parts by mass or more, preferably 400 parts by mass or more, and, for example, 700 parts by mass or less, preferably 600 parts by mass or less.

[0109] The mixing ratio of aluminum hydroxide to vinyl ester (aluminum hydroxide / vinyl ester) is 22 or more and 45 or less, preferably 30 or less.

[0110] When the above-mentioned blending ratio is not less than the above-mentioned lower limit, the flame retardancy of a molded article (described later) obtained by using the unsaturated polyester resin composition can be improved.

[0111] On the other hand, when the above-mentioned compounding ratio is less than the above-mentioned lower limit, the flame retardancy of a molded article (described later) obtained by using the unsaturated polyester resin composition decreases.

[0112] When the above-mentioned blending ratio is not more than the above-mentioned upper limit, the mechanical strength (bending properties, tensile properties) of a molded article (described later) obtained by using the unsaturated polyester resin composition can be improved.

[0113] On the other hand, when the above-mentioned mixing ratio exceeds the above-mentioned upper limit, the mechanical strength (bending property, tensile property) of the molded article (described later) obtained by using the unsaturated polyester resin composition is reduced. In addition, the linear expansion coefficient of the molded article (described later) becomes low, and when the molded article is used in combination with a light metal, the difference between the linear expansion coefficient of the molded article (described later) and the linear expansion coefficient of the light metal (e.g., aluminum) causes a reduction in dimensional stability.

[0114] The unsaturated polyester resin composition can be obtained by mixing the unsaturated polyester, the vinyl ester, the polymerizable monomer, and aluminum hydroxide in the above-mentioned mixing ratio.

[0115] In this way, an unsaturated polyester resin composition can be obtained.

[0116] In such an unsaturated polyester resin composition, the proportion of the unsaturated polyester is, for example, 5% by mass or more, preferably 10% by mass or more, and for example, 20% by mass or less, relative to the unsaturated polyester resin composition. In addition, the proportion of the vinyl ester is, for example, 1% by mass or more, and for example, 10% by mass or less, and preferably 5% by mass or less, relative to the unsaturated polyester resin composition. In addition, the proportion of the polymerizable monomer is, for example, 10% by mass or more, and for example, 30% by mass or less, and preferably 20% by mass or less, relative to the unsaturated polyester resin composition. In addition, the proportion of aluminum hydroxide is, for example, 50% by mass or more, and for example, 70% by mass or less, relative to the unsaturated polyester resin composition. In addition, the total amount of the unsaturated polyester, the vinyl ester, and the polymerizable monomer is, for example, 20% by mass or more, preferably 30% by mass or more, and for example, 50% by mass or less, and preferably 40% by mass or less, relative to the unsaturated polyester resin composition. The total amount of the unsaturated polyester, vinyl ester, polymerizable monomer and aluminum hydroxide relative to the unsaturated polyester resin composition is, for example, 60 mass % or more, preferably 70 mass % or more, more preferably 80 mass % or more, and, for example, 99.9 mass % or less.

[0117] Furthermore, a flame retardant may be blended into the unsaturated polyester resin composition as required.

[0118] When the unsaturated polyester resin composition contains a flame retardant, flame retardancy can be imparted to a molded article (described later) obtained using the unsaturated polyester resin composition.

[0119] Examples of the flame retardant include halogen flame retardants such as bromine flame retardants, and non-halogen flame retardants such as phosphorus flame retardants, inorganic flame retardants, and nitrogen compound flame retardants. Preferred examples include non-halogen flame retardants, and more preferred examples include phosphorus flame retardants.

[0120] In addition, commercially available phosphorus-based flame retardants can be used, and specific examples include Exolit AP series (specifically Exolit AP422 (ammonium polyphosphate)), OP series (specifically Exolit OP1230 (phosphinate metal salt)), RP series (manufactured by Clariant International Ltd.), and FP series (specifically FP-2500S phosphate series) (manufactured by ADEKA Co., Ltd.).

[0121] The flame retardant is blended in an amount of, for example, 1 part by mass or more, preferably 5 parts by mass or more, and for example, 50 parts by mass or less, preferably 20 parts by mass or less, relative to 100 parts by mass of the total amount of the unsaturated polyester, the vinyl ester, and the polymerizable monomer.

[0122] In addition, the unsaturated polyester resin composition may be formulated with additives such as a shrinkage reducing agent, a polymerization inhibitor, a curing agent, a mold release agent, a coloring agent, a filler, a wetting and dispersing agent, and a thickener as required. These additives may be used alone or in combination of two or more.

[0123] The shrinkage reducing agent is blended in order to suppress the curing shrinkage and thermal shrinkage of a molded article (described later) when obtaining a molded article (described later) using the unsaturated polyester resin composition.

[0124] Examples of the low shrinkage agent include polyethylene, polystyrene, styrene-based thermoplastic elastomers, crosslinked polystyrene, polyvinyl acetate-polystyrene block copolymers, polyvinyl acetate, polymethyl methacrylate, and saturated polyester resins. Preferred examples include polyethylene, polystyrene, polyvinyl acetate, and saturated polyester resins.

[0125] The saturated polyester resin can be obtained by dissolving a saturated polyester in the above-mentioned polymerizable monomer.

[0126] The saturated polyester is a polymerization product of the above-mentioned polybasic acid not containing an ethylenically unsaturated bond and the above-mentioned polyol.

[0127] As the polybasic acid not containing an ethylenically unsaturated bond, preferably, a saturated aliphatic polybasic acid and an aromatic polybasic acid are mentioned, more preferably, a saturated aliphatic dibasic acid and an aromatic dibasic acid are mentioned, and further preferably, adipic acid and isophthalic acid are mentioned.

[0128] The polybasic acid not containing an ethylenically unsaturated bond may be used alone or in combination of two or more.

[0129] As the polyol, preferably, diol is used, and more preferably, neopentyl glycol is used.

[0130] The polyols can be used alone or in combination of two or more.

[0131] The saturated polyester can be obtained by polycondensing (condensation polymerization) a polybasic acid not containing an ethylenically unsaturated bond and a polyol.

[0132] In order to polycondense a polyacid not containing an ethylenically unsaturated bond with a polyol (condensation polymerization), the equivalent ratio of the polyol to the polyacid (hydroxyl group of the polyol / carboxyl group of the polyacid) is, for example, 0.9 or more, preferably 0.95 or more, and for example, 1.2 or less, preferably 1.1 or less, and stirring is carried out under normal pressure and a nitrogen atmosphere.

[0133] The reaction temperature is, for example, 150° C. or higher, preferably 190° C. or higher, and, for example, 250° C. or lower, preferably 230° C. or lower.

[0134] The reaction time is, for example, 8 hours or longer, and, for example, 30 hours or shorter.

[0135] In the above-mentioned reaction, a known solvent and a known catalyst may be added as necessary.

[0136] In this way, a saturated polyester can be obtained.

[0137] The acid value of the saturated polyester (measurement method: in accordance with JIS K6901 (2008)) is, for example, 5 mgKOH / g or more and less than 40 mgKOH / g.

[0138] Then, the saturated polyester is dissolved in the above-mentioned polymerizable monomer (preferably styrene), and an additive (polymerization inhibitor (described later) (preferably hydroquinone)) is added as necessary to prepare a saturated polyester resin.

[0139] In the preparation of the saturated polyester resin, the proportion of the polymerizable monomer is, for example, 35 parts by mass or more, and, for example, 150 parts by mass or less, relative to 100 parts by mass of the saturated polyester; the proportion of the polymerization inhibitor is, for example, 0.001 parts by mass or more, and preferably 0.005 parts by mass or more, and, for example, 0.1 parts by mass or less, and preferably 0.05 parts by mass or less, relative to 100 parts by mass of the saturated polyester.

[0140] The shrinkage reducing agent may be used alone or in combination of two or more.

[0141] The blending ratio of the shrinkage reducing agent is 5 parts by mass or more, preferably 10 parts by mass or more, and for example, 30 parts by mass or less, preferably 20 parts by mass or less, based on 100 parts by mass of the total amount of the unsaturated polyester, vinyl ester and polymerizable monomer.

[0142] The polymerization inhibitor is blended for adjusting the usable time and the curing reaction, and examples thereof include hydroquinone compounds such as hydroquinone, methyl hydroquinone, and tert-butyl hydroquinone, benzoquinone compounds such as p-benzoquinone and methyl p-benzoquinone, catechol compounds such as tert-butyl catechol, phenol compounds such as 2,6-di-tert-butyl-4-methylphenol and 4-methoxyphenol, and 1-oxy-2,2,6,6-tetramethylpiperidine, 1-oxy-2,2,6,6-tetramethylpiperidin-4-ol, 4-hydroxy-2,2,6,6-tetrapiperidin-1-oxyl, 4-methoxy-2, 2,6,6-tetramethylpiperidin-1-oxyl, 1-oxy-2,2,6,6-tetramethylpiperidin-4-yl acetate, 1-oxy-2,2,6,6-tetramethylpiperidin-4-yl-2-ethyl hexanoate, 1-oxy-2,2,6,6-tetramethylpiperidin-4-yl stearate, 1-oxy-2,2,6,6-tetramethylpiperidin-4-yl 4-tert-butylbenzoate, bis(1-oxy-2,2,6,6-tetramethylpiperidin-4-yl) succinate, bis(1-oxy-2,2,6,6-tetramethylpiperidin-4-yl) adipate, sebacic acid Bis(1-oxy-2,2,6,6-tetramethylpiperidin-4-yl) ester, bis(1-oxy-2,2,6,6-tetramethylpiperidin-4-yl) malonate, bis(1-oxy-2,2,6,6-tetramethylpiperidin-4-yl) phthalate, bis(1-oxy-2,2,6,6-tetramethylpiperidin-4-yl) isophthalate, bis(1-oxy-2,2,6,6-tetramethylpiperidin-4-yl) terephthalate, bis(1-oxy-2,2,6,6-tetramethylpiperidin-4-yl) hexahydroterephthalate, N,N'-bis(1-oxy-2,2,6,6-tetramethylpiperidin-4-yl) N-oxyl compounds such as (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)adipamide, N-bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)caprolactam, N-bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)dodecylsuccinimide, 2,4,6-tri-[N-butyl-N-(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)]-s-triazine, and 1-oxyl-2,2,6,6-tetramethylpiperidin-4-one, preferably benzoquinone compounds, more preferably p-benzoquinone.

[0143] The blending ratio of the polymerization inhibitor is, for example, 0.01 parts by mass or more, and for example, 0.1 parts by mass or less, relative to 100 parts by mass of the total amount of the unsaturated polyester, the vinyl ester, and the polymerizable monomer.

[0144] The polymerization inhibitors may be used alone or in combination of two or more.

[0145] Examples of the curing agent include peroxides such as benzoyl peroxide, tert-butyl peroxyisopropyl monocarbonate, tert-amyl peroxyisopropyl monocarbonate, tert-hexyl peroxyisopropyl monocarbonate, 1,1-bis(tert-butylperoxy)cyclohexane, tert-butyl peroxy-2-ethylhexanoate, pentyl peroxy-2-ethylhexanoate, 2-ethylhexyl peroxy-2-ethylhexanoate, tert-butyl peroxybenzoate, tert-hexyl peroxybenzoate, and tert-hexyl peroxyacetate. Preferred examples of the curing agent include peroxyisopropyl monocarbonate such as tert-butyl peroxyisopropyl monocarbonate, tert-amyl peroxyisopropyl monocarbonate, tert-hexyl peroxyisopropyl monocarbonate, and tert-butyl peroxybenzoate.

[0146] The mixing ratio of the curing agent relative to 100 parts by mass of the total amount of the unsaturated polyester, the vinyl ester and the polymerizable monomer is, for example, 0.5 parts by mass or more, preferably 1 part by mass or more, and for example, 10 parts by mass or less, preferably 3 parts by mass or less.

[0147] The curing agent can be used alone or in combination of two or more.

[0148] Examples of the release agent include fatty acids such as stearic acid and lauric acid, fatty acid metal salts such as zinc stearate and calcium stearate, paraffin wax, liquid wax, fluoropolymers, and silicon-based polymers. Fatty acid metal salts are preferred, and zinc stearate is more preferred.

[0149] The mixing ratio of the release agent is, for example, 1 part by mass or more, preferably 3 parts by mass or more, and for example, 10 parts by mass or less, relative to 100 parts by mass of the total amount of the unsaturated polyester, the vinyl ester, and the polymerizable monomer.

[0150] The release agents may be used alone or in combination of two or more.

[0151] The colorant is not particularly limited, and examples thereof include titanium oxide and polyester toner (a polyester colorant containing titanium oxide and / or carbon black). Preferably, the polyester toner is used.

[0152] The mixing ratio of the colorant is, for example, 1 part by mass or more, preferably 5 parts by mass or more, and for example, 20 parts by mass or less per 100 parts by mass of the total amount of the unsaturated polyester, the vinyl ester, and the polymerizable monomer.

[0153] The coloring agents can be used alone or in combination of two or more.

[0154] Examples of fillers include oxides such as aluminum oxide and titanium dioxide, hydroxides such as magnesium hydroxide (excluding aluminum hydroxide), carbonates such as calcium carbonate, sulfates such as barium sulfate, silica (such as crystalline silica, fused silica, fumed silica, dry silica (aerogel), etc.), hollow fillers such as glass powder, glass balls, silica balls, and alumina balls, silicates such as silica sand, diatomaceous earth, mica, clay, kaolin, and talc, fluorides such as fluorite, phosphates such as calcium phosphate, and clay minerals such as smectite. Inorganic fillers and the like can be cited.

[0155] The proportion of the filler relative to 100 parts by mass of the total amount of the unsaturated polyester, vinyl ester and polymerizable monomer is, for example, 1 part by mass or more, preferably 3 parts by mass or more, and for example, 50 parts by mass or less, preferably 30 parts by mass or less.

[0156] The filler may be used alone or in combination of two or more.

[0157] The wetting dispersant is blended to reduce the viscosity of the unsaturated polyester resin composition to a level suitable for heat compression molding, and examples thereof include known wetting dispersants such as phosphoric acid polyesters. In addition, commercially available wetting dispersants can be used, and specifically, BYK-W996 (manufactured by BYK Japan KK) can be used.

[0158] The mixing ratio of the wetting and dispersing agent relative to 100 parts by mass of the total amount of the unsaturated polyester, the vinyl ester and the polymerizable monomer is, for example, 0.5 parts by mass or more, preferably 1 part by mass or more, and for example, 10 parts by mass or less, preferably 3 parts by mass or less.

[0159] The wetting and dispersing agents may be used alone or in combination of two or more.

[0160] The thickener is blended in order to increase the viscosity of the unsaturated polyester resin composition to a viscosity suitable for heat compression molding, and is preferably blended before (preferably immediately before) the unsaturated polyester resin composition is impregnated into reinforcing fibers (described later). Examples thereof include alkaline earth metal oxides such as magnesium oxide, and alkaline earth metal hydroxides such as magnesium hydroxide and calcium hydroxide. Alkaline earth metal oxides are preferred, and magnesium oxide is more preferred.

[0161] The blending ratio of the thickener is, for example, 0.5 parts by mass or more, and for example, 10 parts by mass or less, and preferably 3 parts by mass or less, relative to 100 parts by mass of the total amount of the unsaturated polyester, the vinyl ester, and the polymerizable monomer.

[0162] The thickeners may be used alone or in combination of two or more.

[0163] In addition, in the unsaturated polyester resin composition, as required, additives such as handle materials, antibacterial agents, hydrophilic agents, photocatalysts, ultraviolet absorbers, ultraviolet stabilizers, anti-separation agents, silane coupling agents, antistatic agents, thixotropy imparting agents, thixotropy stabilizers, and polymerization accelerators may be added within a range that does not impair the effects of the present invention. These additives may be used alone or in combination of two or more.

[0164] It should be noted that, in the above description, the unsaturated polyester, vinyl ester, polymerizable monomer, aluminum hydroxide, a flame retardant blended as required, and an additive blended as required are blended to obtain an unsaturated polyester resin composition, but the unsaturated polyester resin may also be prepared by first dissolving the unsaturated polyester in the polymerizable monomer, and then the obtained unsaturated polyester resin, vinyl ester, polymerizable monomer, aluminum hydroxide, a flame retardant blended as required, and an additive blended as required are blended.

[0165] In the preparation of the unsaturated polyester resin, not only the unsaturated polyester and the polymerizable monomer may be blended, but also the above-mentioned additives (for example, a polymerization inhibitor) may be appropriately blended as necessary.

[0166] In the preparation of the unsaturated polyester resin, the proportion of the polymerizable monomer is, for example, 35 parts by mass or more, and for example, 150 parts by mass or less, relative to 100 parts by mass of the unsaturated polyester; the proportion of the polymerization inhibitor is, for example, 0.001 parts by mass or more, and preferably 0.005 parts by mass or more, and for example, 0.1 parts by mass or less, and preferably 0.05 parts by mass or less, relative to 100 parts by mass of the unsaturated polyester.

[0167] Alternatively, a vinyl ester resin may be prepared by dissolving a vinyl ester in a polymerizable monomer, and then the obtained vinyl ester resin, unsaturated polyester, polymerizable monomer, aluminum hydroxide, a flame retardant as required, and additives as required may be blended.

[0168] In the preparation of the vinyl ester resin, not only the unsaturated polyester and the polymerizable monomer may be blended, but also the above-mentioned additives may be appropriately blended as necessary.

[0169] In the preparation of the vinyl ester resin, the mixing ratio of the polymerizable monomer relative to 100 parts by mass of the vinyl ester is, for example, 35 parts by mass or more, and for example, 150 parts by mass or less.

[0170] Alternatively, the unsaturated polyester resin and the vinyl ester resin may be first prepared by the above method, and then the obtained unsaturated polyester resin, the obtained vinyl ester resin, the polymerizable monomer, aluminum hydroxide, a flame retardant as required, and additives as required may be blended.

[0171] In the unsaturated polyester resin composition obtained as described above, the blending ratio of the vinyl ester to the unsaturated polyester is a predetermined ratio.

[0172] Therefore, a molded article (described later) obtained using the unsaturated polyester resin composition has excellent mechanical properties (bending properties, tensile properties) and low shrinkage.

[0173] In addition, in the unsaturated polyester resin composition, the mixing ratio of aluminum hydroxide to vinyl ester is a predetermined ratio.

[0174] Therefore, a molded article (described later) obtained using the unsaturated polyester resin composition has excellent flame retardancy and excellent mechanical properties (flexural properties and tensile properties).

[0175] That is, the unsaturated polyester resin composition contains a predetermined ratio of vinyl ester and a predetermined ratio of aluminum hydroxide.

[0176] Therefore, a molded article (described later) obtained using the unsaturated polyester resin composition is excellent in flame retardancy and mechanical strength and has low shrinkage.

[0177] Furthermore, by blending reinforcing fibers into such an unsaturated polyester resin composition, a molding material can be prepared. Furthermore, a molded article can be obtained from such a molding material by a known method.

[0178] Examples of the reinforcing fibers include inorganic fibers such as glass fibers, carbon fibers, metal fibers, and ceramic fibers; organic fibers such as polyvinyl alcohol fibers, polyester fibers, polyamide fibers, fluororesin fibers, and phenol fibers; and natural fibers such as hemp and kenaf. Preferably, inorganic fibers are used; more preferably, carbon fibers and glass fibers are used; and further preferably, glass fibers are used.

[0179] The shape of these reinforcing fibers may be a cloth shape such as roving cloth, a mat shape such as chopped strand mat, a preformable mat, a continuous strand mat, a surfacing mat, a strand shape such as chopped strand, a roving shape, a nonwoven fabric shape, a paper shape, etc. Preferably, a chopped strand is used.

[0180] Among these reinforcing fibers, preferably, there is mentioned a chopped glass strand obtained by bundling glass fibers and cutting them into a predetermined length.

[0181] The length of the reinforcing fibers is not particularly limited, and is, for example, 0.1 mm or more, preferably 1.5 mm or more, more preferably 5 mm or more, further preferably 15 mm or more, and is, for example, 80 mm or less, preferably 40 mm or less.

[0182] Furthermore, the molding material can be obtained as a sheet-shaped molding material, for example, by impregnating reinforcing fibers with the unsaturated polyester resin composition.

[0183] The blending ratio of the reinforcing fiber (for example, when the reinforcing fiber is glass fiber, hereinafter referred to as the glass content) relative to the total amount of the unsaturated polyester resin composition and the reinforcing fiber is, for example, 5 mass % or more, preferably 10 mass % or more, more preferably 20 mass % or more, and for example, 50 mass % or less, preferably 40 mass % or less.

[0184] As a method for preparing the molding material, a known method may be mentioned, for example, SMC (sheet molding compound), TMC (sheet molding compound), BMC (bulk molding compound) and the like may be mentioned, and SMC is preferred.

[0185] Thereby, a molding material comprising the above-mentioned unsaturated polyester resin composition and reinforcing fibers can be obtained.

[0186] With respect to the molding material, in the above-mentioned unsaturated polyester resin composition, the total amount (volume content) of components other than fillers (specifically, the total amount of unsaturated polyester, vinyl ester, polymerizable monomer, flame retardant mixed as required, and other additives other than fillers mixed as required) other than aluminum hydroxide and fillers mixed as required is, for example, 40% by volume or more, preferably 45% by volume or more, and, for example, 70% by volume or less, preferably 60% by volume or less.

[0187] The volume content of aluminum hydroxide relative to the molding material is, for example, 10 volume % or more, preferably 20 volume % or more, and for example, 30 volume % or less.

[0188] The volume content of the reinforcing fibers relative to the molding material is, for example, 15 volume % or more, preferably 20 volume % or more, and, for example, 40 volume % or less, preferably 30 volume % or less.

[0189] Since the molding material contains the above-mentioned unsaturated polyester resin composition, a molded article (described later) obtained using the molding material has excellent flame retardancy and mechanical strength and low shrinkage.

[0190] Next, in order to thicken the molding material so as to enable heat compression molding (described later), the molding material is preferably aged under conditions of, for example, 20° C. to 50° C. for 8 to 120 hours.

[0191] Thereby, the shape of the molding material can be maintained in, for example, a sheet shape. That is, the molding material has a sheet shape.

[0192] Furthermore, the molded product can be obtained by heating and compression molding a molding material using a known method.

[0193] The conditions for heat compression molding can be appropriately set according to the purpose and use. Specifically, the molding temperature is, for example, above 100°C, and further, for example, below 200°C. In addition, the molding pressure is, for example, above 0.1 MPa, preferably above 1 MPa, more preferably above 5 MPa, and further, for example, below 20 MPa, preferably below 15 MPa.

[0194] Thereby, the molding material can be molded while the molding material is being solidified.

[0195] Thereby, a molded product can be obtained.

[0196] Since the molded article includes a cured product of the above-mentioned molding material, it is excellent in flame retardancy and mechanical strength and has low shrinkage.

[0197] Such molded products can be widely used in building materials, housings, casting materials, mechanical parts (e.g., battery pack cases of electric vehicles), electronic and electrical parts, and various components of vehicles, ships, aircraft, etc.

[0198] In particular, excellent flame retardancy is sometimes required for battery pack cases of electric vehicles in order to slow down the spread of fire during a vehicle fire.

[0199] Furthermore, in order to reduce warping and deformation, the battery pack case of an electric vehicle is sometimes required to have excellent mechanical strength and low shrinkage.

[0200] On the other hand, the molded article is excellent in flame retardancy and mechanical strength and has low shrinkage, and therefore can be suitably used for a battery pack case of an electric vehicle.

[0201] Example

[0202] The specific numerical values ​​of the mixing ratio (content ratio), physical property values, parameters, etc. used in the following description can be replaced by the upper limit value (the numerical value defined in the form of "below" or "lower than") or the lower limit value (the numerical value defined in the form of "above" or "higher than") of the corresponding mixing ratio (content ratio), physical property values, parameters, etc. recorded in the above-mentioned "Specific Embodiment". In addition, in the following description, unless otherwise specified, "parts" and "%" are based on mass.

[0203] 1. Preparation of unsaturated polyester resin

[0204] Synthesis example 1

[0205] 10.0 mol of maleic anhydride, 6.5 mol of propylene glycol and 4.0 mol of neopentyl glycol were placed in a flask equipped with a thermometer, a nitrogen inlet tube, a reflux condenser and a stirrer, and polycondensation reaction was carried out at 200°C to 210°C under a nitrogen atmosphere while stirring to obtain an unsaturated polyester having an acid value of 26.5 mgKOH / g. It should be noted that the method for determining the acid value is in accordance with JIS K6901 (2008). 0.01 mol of hydroquinone and 66.7 mol of styrene were added as a polymerization inhibitor to 100 mol of the obtained unsaturated polyester, and they were mixed uniformly to obtain an unsaturated polyester resin (styrene content of 40%).

[0206] 2. Preparation of saturated polyester resin

[0207] Synthesis example 2

[0208] In a flask equipped with a thermometer, a nitrogen inlet tube, a reflux condenser and a stirrer, 4.0 mol of isophthalic acid and 10.5 mol of neopentyl glycol were charged, and polycondensation reaction was carried out at 200°C to 210°C under a nitrogen atmosphere while stirring. Then, the reaction product was cooled to 150°C when the acid value of the reaction product reached 10 mgKOH / g, 6.0 mol of adipic acid was charged, and the reaction was carried out again at 210°C to 220°C to obtain a saturated polyester having an acid value of 9.5 mgKOH / g. 0.01 parts by mass of hydroquinone and 66.7 parts by mass of styrene were added as a polymerization inhibitor to 100 parts by mass of the obtained saturated polyester, and the mixture was uniformly mixed to obtain a saturated polyester resin (styrene content was 40%).

[0209] 3. Preparation of vinyl ester resin

[0210] Synthesis example 3

[0211] Into a reaction vessel (flask) equipped with a stirrer, a reflux condenser, and a gas introduction tube, 1850 parts by mass (10.0 equivalents) of a bisphenol A type epoxy compound (epoxy equivalent of 185 g / eq), 317 parts by mass (2.78 equivalents) of bisphenol A, and 0.5 parts by mass of triethylbenzylammonium chloride as a catalyst were charged, and reacted at 150° C. for 5 hours while blowing nitrogen to obtain an epoxy resin with an epoxy equivalent of 298 g / eq. After cooling to 120° C., 2.0 parts by mass of hydroquinone as a polymerization inhibitor, 2.0 parts by mass of triethylbenzylammonium chloride as a catalyst, and 636 parts by mass (7.40 equivalents) of methacrylic acid were added, and reacted at 110° C. for 8 hours while blowing air to obtain a vinyl ester with an acid value of 8.0 mgKOH / g. Next, 1869 parts by mass of styrene (66.7 parts by mass relative to 100 parts by mass of the vinyl ester) was added to the vinyl ester to obtain a vinyl ester resin containing 40% by mass of styrene.

[0212] Synthesis example 4

[0213] Into the same reaction vessel as in Synthesis Example 3, 1850 parts by mass (10.0 equivalents) of bisphenol A type epoxy compound (epoxy equivalent of 185 g / eq), 477 parts by mass (4.18 equivalents) of bisphenol A, and 0.5 parts by mass of triethylbenzylammonium chloride as a catalyst were charged, and reacted at 150° C. for 5 hours while blowing nitrogen, to obtain an epoxy resin with an epoxy equivalent of 395 g / eq. After cooling to 120° C., 2.0 parts by mass of hydroquinone as a polymerization inhibitor, 2.0 parts by mass of triethylbenzylammonium chloride as a catalyst, and 513 parts by mass (5.97 equivalents) of methacrylic acid were added, and reacted at 110° C. for 8 hours while blowing air, to obtain a vinyl ester with an acid value of 8.5 mgKOH / g. Next, 1893 parts by mass of styrene (66.7 parts by mass relative to 100 parts by mass of the vinyl ester) was added to the vinyl ester to obtain a vinyl ester resin containing 40% by mass of styrene.

[0214] Synthesis example 5

[0215] Into the same reaction vessel as in Synthesis Example 3, 1800 parts by mass (10.0 equivalents) of phenol Novolac type epoxy resin (epoxy equivalent: 180 g / eq, average functional group number: 3.6), 2.0 parts by mass of hydroquinone as a polymerization inhibitor, 2.0 parts by mass of triethylbenzylammonium chloride as a catalyst, and 882 parts by mass (10.3 equivalents) of methacrylic acid were added, and reacted at 110° C. for 8 hours while blowing air, to obtain a vinyl ester having an acid value of 10.5 mgKOH / g. Next, 1788 parts by mass of styrene (66.7 parts by mass relative to 100 parts by mass of the vinyl ester) was added to the vinyl ester, thereby obtaining a vinyl ester resin containing 40% by mass of styrene.

[0216] 4. Preparation of unsaturated polyester resin composition and molding material

[0217] Example 1

[0218] 60 parts by mass of the unsaturated polyester resin of Synthesis Example 1 (36 parts by mass of unsaturated polyester, 24 parts by mass of styrene), 10 parts by mass of the vinyl ester resin of Synthesis Example 3 (6 parts by mass of vinyl ester, 4 parts by mass of styrene), 10 parts by mass of styrene as a polymerizable monomer, 150 parts by mass of aluminum hydroxide (average particle size of 8 μm), 15 parts by mass of a polystyrene solution (35% styrene solution of polystyrene having a weight average molecular weight of about 250,000) as a low shrinkage agent, 5 parts by mass of polyethylene powder, 0.05 parts by mass of p-benzoquinone as a polymerization inhibitor, 1 part by mass of tert-butyl perbenzoate as a curing agent, 5 parts by mass of zinc stearate as a release agent, 10 parts by mass of a black polyester toner (a toner obtained by dispersing carbon black in a polyester resin) as a colorant, and 1 part by mass of a phosphoric acid polyester as a wetting dispersant were mixed to obtain an unsaturated polyester resin composition.

[0219] To the unsaturated polyester resin composition, 0.8 parts by mass of magnesium oxide as a thickener was added, and then, as reinforcing fibers, glass chopped strands obtained by continuously cutting glass roving into 25 mm were added so that the glass content became 20.7% by mass. A molding material (SMC) was obtained using a known SMC impregnation machine, and then, the molding material was aged at 40° C. for 48 hours to thicken the material until it became a state that could be heat-compression molded.

[0220] Examples 2 to 9 and Comparative Examples 1 to 8

[0221] Except for changing the compounding formula as described in Table 1 and Table 2, the same treatment as in Example 1 was carried out to obtain a molding material.

[0222] In addition, in Example 2 and Example 6, a polyvinyl acetate solution (40% styrene solution of polyvinyl acetate) was used as a shrinkage reducing agent.

[0223] In Example 9 and Comparative Example 7, a phosphinate metal salt (OP1230 (trade name, Exolit OP1230, manufactured by Clariant International Ltd., phosphorus content: 23%)) was used as a flame retardant.

[0224] In Comparative Examples 5 and 8, calcium carbonate having an average particle size of about 3 μm was used as the filler.

[0225] 5. Evaluation

[0226] (Molding shrinkage)

[0227] The molding materials of each example and each comparative example were heat-compressed and molded using a 300 mm×300 mm flat metal plate to obtain a flat molded product having a thickness of 4 mm.

[0228] The molding was carried out under the conditions of 140°C mold temperature on both the product surface and the back surface, 10 MPa molding pressure, and 420 seconds of holding time in the mold. Then, the molded product was demolded from the mold and immediately sandwiched between iron plates for cooling. Then, the molded product was placed at 25°C for 24 hours, and the dimensions of the four sides of the molded product at 25°C were measured, and the shrinkage was measured by the ratio with the dimensions of the above-mentioned flat mold. The results are shown in Tables 3 and 4.

[0229] In addition, the shrinkage rate was evaluated according to the following criteria. The results are shown in Tables 3 and 4.

[0230] Evaluation criteria:

[0231] ◎: Shrinkage rate is less than 0.00.

[0232] ○: The shrinkage rate is 0.00 or more and less than 0.10.

[0233] ×: The shrinkage ratio is 0.10 or more.

[0234] (Flame retardancy)

[0235] The test pieces cut from the flat molded products used for the measurement of mold shrinkage were subjected to a combustion test in accordance with the UL94 standard (combustibility test of plastic materials) of the UL standard (Underwriters Laboratories Inc.). Specifically, the test pieces with a thickness of 4 mm, a thickness of 3 mm, and a thickness of 2.5 mm were used to evaluate whether they met the V-0 standard. The results are shown in Tables 3 and 4.

[0236] In addition, regarding flame retardancy, the quality was evaluated according to the following criteria. The results are shown in Tables 3 and 4.

[0237] Evaluation criteria:

[0238] ◎: Conforms to the V-0 standard (thickness 2 mm).

[0239] ○: Conforms to the V-0 standard (thickness: 3 mm).

[0240] ×: Does not meet the V-0 standard (thickness 4 mm).

[0241] (Linear expansion coefficient)

[0242] A test piece (4 mm × 4 mm × 5 mm) was cut from a flat molded product (4 mm thick) used in the measurement of mold shrinkage, and the linear expansion coefficient in the horizontal direction of the molded product was measured using a compression / expansion probe in a thermomechanical analyzer (manufactured by Hitachi High-Tech Science Corporation, EXSTAR TMASS7100). The temperature was raised from room temperature to 100°C at a heating rate of 5°C / min, and the linear expansion coefficient in the range of 50°C to 80°C was measured. The results are shown in Tables 3 and 4.

[0243] In addition, the difference between the obtained linear expansion coefficient and the linear expansion coefficient of aluminum (23.0 ppm / ° C.) is also shown in Tables 3 and 4.

[0244] The linear expansion coefficient was evaluated based on the following criteria. The results are shown in Tables 3 and 4.

[0245] ○: The absolute value of the difference in linear expansion coefficient from aluminum is 0 or more and less than 4.5

[0246] △: The absolute value of the difference in linear expansion coefficient from aluminum is 4.5 or more and less than 6

[0247] ×: The absolute value of the difference in linear expansion coefficient from aluminum is 6 or more

[0248] (Smoky)

[0249] In the flame retardancy test, in the V-0 judgment test when using a test piece having a thickness of 3 mm, it was visually observed whether black smoke was generated during combustion.

[0250] The smoke generation properties were evaluated based on the following criteria. The results are shown in Tables 3 and 4.

[0251] ○: No black smoke was generated.

[0252] ×: Black smoke was generated.

[0253] (density)

[0254] A test piece was cut out from a flat plate-shaped molded product (thickness 4 mm) used for measuring the mold shrinkage, and the density was measured in accordance with JIS K6911 (1995).

[0255] (Bending characteristics)

[0256] Test pieces (length 80 mm, width 10 mm) were cut out from the flat plate-shaped molded product (thickness 4 mm) used for the measurement of mold shrinkage, and the flexural strength and flexural modulus were measured at 23° C. and 90° C. in accordance with JIS K7017 (1999). The results are shown in Tables 3 and 4.

[0257] In addition, the specific rigidity at 23° C. and 90° C. was calculated from the measurement results of the bending elastic modulus and the density using the following formula (1). The results are shown in Tables 3 and 4.

[0258] Specific stiffness = (bending modulus of elasticity) 1 / 3 / (density) (1)

[0259] (Tensile properties)

[0260] Test pieces were cut out from the flat plate-shaped molded product (thickness 4 mm) used for the measurement of mold shrinkage, and the tensile strength and tensile modulus were measured at 23° C. in accordance with JIS K7164 (2005).

[0261] [Table 1]

[0262]

[0263] [Table 2]

[0264]

[0265] [Table 3]

[0266]

[0267] [Table 4]

[0268]

[0269] It should be noted that the above invention is provided as an exemplary embodiment of the present invention, but it is merely an illustration and is not to be construed as limiting. Modifications of the present invention that are obvious to those skilled in the art are also included in the scope of the appended claims.

[0270] Industrial Applicability

[0271] The unsaturated polyester resin composition, molding material and molded product of the present invention can be suitably used for building materials, housings, casting materials, mechanical parts (e.g., battery pack cases of electric vehicles), electronic and electrical parts, and various components of vehicles, ships, aircraft, etc.

Claims

1. A molding material, characterized in that: Comprising an unsaturated polyester resin composition, and reinforcing fibers, The unsaturated polyester resin composition comprises unsaturated polyester, vinyl ester, polymerizable monomer, and aluminum hydroxide. The vinyl ester is the reaction product of an epoxy resin and an unsaturated monobasic acid. The mixing ratio of the vinyl ester is 5 parts by mass or more and 16.7 parts by mass or less relative to 100 parts by mass of the unsaturated polyester. The mixing ratio of the aluminum hydroxide to the vinyl ester, i.e., the ratio of aluminum hydroxide / vinyl ester, is 22 to 30, wherein the mixing ratio is a mass ratio. The blending ratio of the reinforcing fiber is 5 mass % or more and 50 mass % or less relative to the total amount of the unsaturated polyester resin composition and the reinforcing fiber.

2. The molding material according to claim 1, characterized in that The epoxy resin is a bisphenol epoxy resin, The epoxy equivalent of the epoxy resin is greater than or equal to 250 g / eq and less than or equal to 350 g / eq.

3. The molding material according to claim 2, characterized in that The epoxy resin is bisphenol A type epoxy resin.

4. The molding material according to claim 1, characterized in that The unsaturated polyester resin composition further comprises a flame retardant.

5. A molded article, characterized in that: A cured product comprising the molding material according to claim 1.

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