Unsaturated polyester resin composition and molded article

Abstract

An unsaturated polyester resin composition according to the present invention contains a resin component containing an unsaturated polyester and a polymerizable monomer. The unsaturated polyester is the reaction product of a polybasic acid and a polyhydric alcohol. The polybasic acid includes a polybasic acid that contains an ethylenically unsaturated bond and a polybasic acid that does not contain an ethylenically unsaturated bond. The polybasic acid that does not contain an ethylenically unsaturated bond includes a saturated aliphatic polybasic acid having 7 or more carbon atoms. The content ratio of the saturated aliphatic polybasic acid having 7 or more carbon atoms is 30 mol% or more with respect to 100 mol% of the polybasic acid that does not contain an ethylenically unsaturated bond. The polybasic acid and / or the polyhydric alcohol has an aromatic ring. The polymerizable monomer contains a styrene-based monomer.

Description

Unsaturated polyester resin composition and molded article

[0001] The present invention relates to an unsaturated polyester resin composition and a molded article, and more specifically relates to an unsaturated polyester resin composition and a molded article including a cured product of a molding material containing the unsaturated polyester resin composition.

[0002] Conventionally, molded articles including a cured product of an unsaturated polyester resin composition containing an unsaturated polyester resin have been used in a wide range of fields because they are excellent in mechanical properties, water resistance, electrical insulation properties, and corrosion resistance.

[0003] As an unsaturated polyester resin composition, for example, a thermosetting resin composition containing an unsaturated polyester and styrene has been proposed (see, for example, Patent Document 1 below). In Patent Document 1, an unsaturated polyester is produced by setting the molar ratio of propylene glycol, sebacic acid, and maleic anhydride to 2:1:1.

[0004] Japanese Patent Application Laid-Open No. 55-137965

[0005] On the other hand, molded articles are required to have water resistance depending on their purposes and applications.

[0006] Further, in the preparation of an unsaturated polyester resin, the unsaturated polyester is sometimes dissolved in a styrenic monomer. Therefore, the unsaturated polyester is required to have solubility in styrenic monomers.

[0007] The present invention provides an unsaturated polyester resin composition excellent in water resistance and solubility in styrenic monomers, and a molded article including a cured product of a molding material containing the unsaturated polyester resin composition.

[0008] The present invention [1] is an unsaturated polyester resin composition comprising a resin component including an unsaturated polyester and a polymerizable monomer, wherein the unsaturated polyester is a reaction product of a polybasic acid and a polyhydric alcohol, the polybasic acid includes an ethylenically unsaturated bond-containing polybasic acid and an ethylenically unsaturated bond-free polybasic acid, the ethylenically unsaturated bond-free polybasic acid includes a saturated aliphatic polybasic acid having 7 or more carbon atoms, the content of the saturated aliphatic polybasic acid having 7 or more carbon atoms is 30 mol% or more with respect to 100 mol% of the ethylenically unsaturated bond-free polybasic acid, the polybasic acid and / or the polyhydric alcohol has an aromatic ring, and the polymerizable monomer includes a styrene monomer.

[0009] The present invention [2] comprises the unsaturated polyester resin composition described in [1] above, wherein the ethylenically unsaturated bond-free polybasic acid has an aromatic ring.

[0010] The present invention [3] includes the unsaturated polyester resin composition described in [1] above, wherein the molar ratio of the polybasic acid without an ethylenically unsaturated bond to the polybasic acid containing an ethylenically unsaturated bond is 2.5 or more.

[0011] The present invention [4] comprises the unsaturated polyester resin composition described in [1] above, wherein the polyhydric alcohol includes a branched aliphatic alcohol.

[0012] The present invention [5] includes a molded article comprising a cured product of a molding material containing an unsaturated polyester resin composition as described in any one of the above items [1] to [4].

[0013] In the unsaturated polyester resin composition of the present invention, the ethylenically unsaturated bond-free polybasic acid includes a saturated aliphatic dibasic acid having 7 or more carbon atoms, and the content of the saturated aliphatic dibasic acid having 7 or more carbon atoms is 30 mol% or more relative to the ethylenically unsaturated bond-free polybasic acid. Therefore, water resistance can be improved.

[0014] Furthermore, in the unsaturated polyester resin composition, the polybasic acid and / or polyhydric alcohol have an aromatic ring. Therefore, solubility in styrene monomers can be improved.

[0015] The molded article of the present invention includes a cured product of a molding material containing the unsaturated polyester resin composition of the present invention. Therefore, water resistance can be improved.

[0016] 1. Unsaturated polyester resin composition The unsaturated polyester resin composition contains a resin component.

[0017] [Resin components] The resin components include unsaturated polyester, polymerizable monomers, and a low-shrinkage agent, which may be added as needed.

[0018] (Unsaturated polyester) Unsaturated polyester is obtained by the reaction of a polybasic acid with a polyhydric alcohol.

[0019] {Polybasic Acids} Polybasic acids include polybasic acids having an ethylenically unsaturated double bond (hereinafter referred to as ethylenically unsaturated bond-containing polybasic acids) and polybasic acids not having an ethylenically unsaturated double bond (hereinafter referred to as ethylenically unsaturated bond-free polybasic acids).

[0020] Examples of polybasic acids containing ethylenically unsaturated bonds include ethylenically unsaturated aliphatic dibasic acids, ethylenically unsaturated aromatic dibasic acids, anhydrides of these acids, halides of these acids, and alkyl esters of these acids.

[0021] Examples of ethylenically unsaturated aliphatic dibasic acids include maleic acid, fumaric acid, itaconic acid, and dihydromoconic acid. An example of an anhydride of an ethylenically unsaturated aliphatic dibasic acid is maleic anhydride.

[0022] An example of an ethylenically unsaturated aromatic dibasic acid is 5-vinylisophthalic acid.

[0023] Preferably, polybasic acids containing ethylenically unsaturated bonds include ethylenically unsaturated aliphatic dibasic acids. More preferably, polybasic acids containing ethylenically unsaturated bonds include maleic acid and fumaric acid.

[0024] More preferably, maleic anhydride is used as the anhydride of an ethylenically unsaturated aliphatic dibasic acid.

[0025] Polybasic acids containing ethylenically unsaturated bonds can be used alone or in combination of two or more types.

[0026] The content of the ethylenically unsaturated bond-containing polybasic acid is, for example, 10 mol% to 40 mol%, preferably 13 mol% to 30 mol%, and more preferably 15 mol% to 25 mol%, relative to 100 mol% of the polybasic acid.

[0027] Polybasic acids that do not contain ethylenically unsaturated bonds include saturated aliphatic polybasic acids with seven or more carbon atoms.

[0028] Examples of saturated aliphatic polybasic acids with 7 or more carbon atoms include saturated aliphatic dibasic acids with 7 or more carbon atoms. Examples of saturated aliphatic dibasic acids with 7 or more carbon atoms include linear saturated aliphatic dibasic acids with 7 or more carbon atoms.

[0029] Examples of linear saturated aliphatic dibasic acids with seven or more carbon atoms include pimelic acid, suberic acid, azelaic acid, and sebacic acid.

[0030] Furthermore, saturated aliphatic polybasic acids with seven or more carbon atoms also include the anhydrides of the above acids, the halides of the above acids, and the alkyl esters of the above acids.

[0031] As a saturated aliphatic polybasic acid having 7 or more carbon atoms, sebacic acid is a preferred example.

[0032] Saturated aliphatic polybasic acids with seven or more carbon atoms can be used alone or in combination of two or more.

[0033] The content of saturated aliphatic polybasic acids with 7 or more carbon atoms is 30 mol% or more, preferably 40 mol% or more, more preferably 50 mol% or more, even more preferably 60 mol% or more, particularly preferably 70 mol% or more, and for example, 90 mol% or less, based on 100 mol% of polybasic acids that do not contain ethylenically unsaturated bonds.

[0034] If the content of saturated aliphatic polybasic acids with 7 or more carbon atoms is above the lower limit mentioned above, water resistance can be improved.

[0035] On the other hand, if the content of saturated aliphatic polybasic acids with 7 or more carbon atoms is below the lower limit, the water resistance will decrease.

[0036] If the content of saturated aliphatic polybasic acids with 7 or more carbon atoms is below the above upper limit, the solubility and mechanical strength in styrene monomers will improve.

[0037] Furthermore, the content of saturated aliphatic polybasic acids with 7 or more carbon atoms is, for example, 20 mol% to 80 mol%, preferably 40 mol% to 70 mol%, and more preferably 55 mol% to 65 mol%, relative to 100 mol% of polybasic acid.

[0038] More specifically, the content of saturated aliphatic polybasic acids with 7 or more carbon atoms is, from the viewpoint of water resistance, for example, 20 mol% or more, preferably 40 mol% or more, and more preferably 55 mol% or more, relative to 100 mol% of polybasic acid, and from the viewpoint of mechanical strength, for example, 80 mol% or less, preferably 70 mol% or less, and more preferably 65 mol% or less.

[0039] Polybasic acids that do not contain ethylenically unsaturated bonds may include not only saturated aliphatic polybasic acids with seven or more carbon atoms, but also other polybasic acids that do not contain ethylenically unsaturated bonds.

[0040] Other polybasic acids that do not contain ethylenically unsaturated bonds include, for example, saturated aliphatic polybasic acids, saturated alicyclic polybasic acids, saturated aromatic polybasic acids, anhydrides of these acids, halides of these acids, and alkyl esters of these acids, all having 2 to 6 carbon atoms.

[0041] Examples of saturated aliphatic polybasic acids having 2 to 6 carbon atoms include saturated aliphatic dibasic acids having 2 to 6 carbon atoms. Examples of saturated aliphatic dibasic acids having 2 to 6 carbon atoms include oxalic acid, malonic acid, succinic acid, methylsuccinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylsuccinic acid, 3,3-dimethylsuccinic acid, glutaric acid, 2-methylglutaric acid, 3-methylglutaric acid, and adipic acid. Examples of anhydrides of saturated aliphatic polybasic acids having 2 to 6 carbon atoms include oxalic anhydride and succinic anhydride.

[0042] Examples of the saturated alicyclic polybasic acid include saturated alicyclic dibasic acids. Examples of the saturated alicyclic dibasic acid include het acid, 1,2-hexahydrophthalic acid, 1,1-cyclobutanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid (cis- or trans-1,4-cyclohexanedicarboxylic acid or a mixture thereof). Examples of an anhydride of the saturated alicyclic polybasic acid include het acid anhydride.

[0043] Examples of the saturated aromatic polybasic acid include saturated aromatic dibasic acids. Examples of the saturated aromatic dibasic acid include phthalic acid (orthophthalic acid, isophthalic acid, terephthalic acid), trimellitic acid, and pyromellitic acid. Examples of an anhydride of the aromatic polybasic acid include phthalic anhydride.

[0044] As another ethylenically unsaturated bond-free polybasic acid, an aromatic polybasic acid is preferably mentioned. As another ethylenically unsaturated bond-free polybasic acid, phthalic acid is more preferably mentioned. As another ethylenically unsaturated bond-free polybasic acid, isophthalic acid is even more preferably mentioned.

[0045] Other ethylenically unsaturated bond-free polybasic acids can be used alone or in combination of two or more.

[0046] The content ratio of other ethylenically unsaturated bond-free polybasic acids is, for example, 10 mol% or more and, for example, 70 mol% or less, preferably 60 mol% or less, more preferably 50 mol% or less, still more preferably 40 mol% or less, particularly preferably 30 mol% or less, based on 100 mol% of the total ethylenically unsaturated bond-free polybasic acids.

[0047] The content ratio of the ethylenically unsaturated bond-free polybasic acids is, for example, 60 mol% to 90 mol%, preferably 70 mol% to 87 mol%, more preferably 75 mol% to 85 mol%, based on 100 mol% of the total polybasic acids.

[0048] Furthermore, the molar ratio of the polybasic acid containing no ethylenically unsaturated bond to the polybasic acid containing an ethylenically unsaturated bond is, for example, 1.1 to 8.0, preferably 1.5 to 7.5, more preferably 2.0 to 7.0, still more preferably 2.5 to 6.5, particularly preferably 3.0 to 6.0, most preferably 3.5 to 5.5, and even more preferably 4.0 to 5.2.

[0049] Specifically, from the viewpoint of water resistance, the above molar ratio is, for example, 1.1 or more, preferably 1.5 or more, more preferably 2.0 or more; from the viewpoint of further improving water resistance, it is still more preferably 2.5 or more, particularly preferably 3.0 or more, most preferably 3.5 or more, and even more preferably 4.0 or more. Further, from the viewpoints of mechanical strength and heat resistance, the molar ratio is, for example, 8.0 or less, preferably 7.5 or less, more preferably 7.0 or less, still more preferably 6.5 or less, particularly preferably 6.0 or less, most preferably 5.5 or less, and even more preferably 5.2 or less.

[0050] {Polyhydric Alcohol} Examples of the polyhydric alcohol include aliphatic alcohols, alicyclic alcohols and aromatic alcohols.

[0051] Examples of the aliphatic alcohol include aliphatic diols and aliphatic triols.

[0052] Examples of the aliphatic diol include linear aliphatic alcohols and branched aliphatic alcohols.

[0053] Examples of the linear aliphatic alcohol include linear alkanediols and linear ether diols.

[0054] Examples of the linear alkanediol include linear alkanediols having 2 to 10 carbon atoms. Examples of the linear alkanediol having 2 to 10 carbon atoms include ethylene glycol, 1,3-propanediol, 1,4-butylene glycol, 1,5-pentanediol, and 1,6-hexanediol. As the linear alkanediol having 2 to 10 carbon atoms, 1,6-hexanediol is preferable.

[0055] Examples of linear ether diols include diethylene glycol and triethylene glycol. Diethylene glycol is preferred as the linear ether diol.

[0056] Examples of branched aliphatic alcohols include branched alkanediols and branched etherdiols.

[0057] Examples of branched alkanediols include those with 2 to 10 branched carbon atoms. Examples of branched alkanediols with 2 to 10 branched carbon atoms include 1,2-propanediol, 1,2-butylene glycol, 1,3-butylene glycol, neopentyl glycol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2,2-trimethylpentanediol, and 3,3-dimethylolheptane. Preferably, 1,2-propanediol is used as the branched alkanediol.

[0058] Examples of branched ether diols include dipropylene glycol.

[0059] Examples of aliphatic triols include glycerol, trimethylolpropane, and triisopropanolamine.

[0060] Examples of alicyclic alcohols include alicyclic diols. Examples of alicyclic diols include cyclohexanediol (1,2- or 1,3- or 1,4-cyclohexanediol or mixtures thereof), cyclohexanedimethanol (1,2- or 1,3- or 1,4-cyclohexanedimethanol or mixtures thereof), cyclohexanediethanol (1,2- or 1,3- or 1,4-cyclohexanediethanol or mixtures thereof), and hydrogenated bisphenol A.

[0061] Examples of aromatic alcohols include aromatic diols. Examples of aromatic diols include ethylene oxide adducts of bisphenol A and propylene oxide adducts of bisphenol A.

[0062] Preferably, the polyhydric alcohol is an aliphatic alcohol. More preferably, the polyhydric alcohol is a branched aliphatic alcohol. In other words, the polyhydric alcohol more preferably includes a branched aliphatic alcohol. If the polyhydric alcohol includes a branched aliphatic alcohol, the solubility in styrene monomers can be improved. Even more preferably, the polyhydric alcohol is a branched alkanediol.

[0063] Polyhydric alcohols can be used alone or in combination of two or more types.

[0064] {Aromatic ring} Polybasic acids and / or polyhydric alcohols have aromatic rings. Specifically, a polybasic acid has an aromatic ring and a polyhydric alcohol has an aromatic ring, or a polybasic acid has an aromatic ring and a polyhydric alcohol does not have an aromatic ring, or a polybasic acid does not have an aromatic ring and a polyhydric alcohol has an aromatic ring. More specifically, a polybasic acid contains an ethylenically unsaturated aromatic dibasic acid and / or a saturated aromatic dibasic acid and a polyhydric alcohol contains an aromatic alcohol, or a polybasic acid contains an ethylenically unsaturated aromatic dibasic acid and / or a saturated aromatic dibasic acid and a polyhydric alcohol does not contain an aromatic alcohol, or a polybasic acid does not contain an ethylenically unsaturated aromatic dibasic acid and a saturated aromatic dibasic acid and a polyhydric alcohol contains an aromatic alcohol.

[0065] Preferably, from the viewpoint of flexibility, the polybasic acid includes an ethylenically unsaturated aromatic dibasic acid and / or a saturated aromatic dibasic acid, and the polyhydric alcohol does not contain an aromatic alcohol.

[0066] Furthermore, preferably, from the viewpoint of softness, the polybasic acid does not contain ethylenically unsaturated aromatic dibasic acids but contains saturated aromatic dibasic acids. In other words, preferably, the ethylenically unsaturated bond-containing polybasic acid does not have an aromatic ring, while the ethylenically unsaturated bond-free polybasic acid has an aromatic ring.

[0067] Furthermore, if polybasic acids and / or polyhydric alcohols have aromatic rings, their solubility in styrene monomers can be improved.

[0068] {Preparation of Unsaturated Polyesters} Unsaturated polyesters are prepared by reacting a polybasic acid with a polyhydric alcohol.

[0069] The equivalent ratio of the polyhydric alcohol to the polybasic acid (hydroxyl group of the polyhydric alcohol / carboxyl group of the polybasic acid) is, for example, 0.90 to 1.20, preferably 0.95 to 1.10.

[0070] The reaction temperature is, for example, 150°C to 250°C, preferably 190°C to 230°C.

[0071] In addition, known solvents and known reaction catalysts may be added to the above reaction as needed.

[0072] This allows for the preparation of unsaturated polyester.

[0073] The acid value of unsaturated polyester (measurement method: in accordance with JIS K6901 (2008)) is, for example, 5 mg KOH / g to 40 mg KOH / g, preferably 10 mg KOH / g to 35 mg KOH / g, and more preferably 20 mg KOH / g to 30 mg KOH / g.

[0074] The weight-average molecular weight of the unsaturated polyester is, for example, 2,000 to 30,000, preferably 3,000 to 25,000, and more preferably 4,000 to 20,000.

[0075] The weight-average molecular weight is the weight-average molecular weight converted to polystyrene, determined by GPC (gel permeation chromatography). The weight-average molecular weight can be determined by GPC measurement of unsaturated polyester.

[0076] Furthermore, unsaturated polyester is preferably flexible.

[0077] Unsaturated polyesters can be used alone or in combination of two or more types.

[0078] The content of unsaturated polyester is, for example, 20% to 80% by mass, preferably 30% to 75% by mass, and more preferably 40% to 70% by mass, relative to the resin component.

[0079] (Polymerizable monomers) Polymerizable monomers include styrene monomers.

[0080] Examples of styrene-based monomers include styrene, vinyltoluene, t-butylstyrene, and chlorostyrene.

[0081] Styrene monomers can be used alone or in combination of two or more types.

[0082] The content of styrene monomer is, for example, 80% by mass or more, preferably 90% by mass or more, and more preferably 100% by mass, relative to the polymerizable monomer.

[0083] Polymerizable monomers may include other polymerizable monomers besides styrene monomers.

[0084] Other polymerizable monomers include, for example, (meth)acrylic acid ester monomers.

[0085] Examples of (meth)acrylic acid ester monomers include alkyl (meth)acrylates, allyl (meth)acrylates, ring-structure-containing (meth)acrylic acid esters, hydroxyalkyl (meth)acrylates, alkoxyalkyl (meth)acrylates, aminoalkyl (meth)acrylates, fluoroalkyl (meth)acrylates, and polyfunctional (meth)acrylic acid esters. Examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate), 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, and stearyl (meth)acrylate. Examples of allyl (meth)acrylates include allyl (meth)acrylate. Examples of ring-structure-containing (meth)acrylate esters include cyclohexyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate. Examples of hydroxyalkyl (meth)acrylate esters include 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate. Examples of alkoxyalkyl (meth)acrylate esters include 2-methoxyethyl (meth)acrylate and 2-ethoxyethyl (meth)acrylate. Examples of aminoalkyl (meth)acrylate esters include dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, and their chloride salts. Examples of (meth)acrylate fluoroalkyl esters include trifluoroethyl (meth)acrylate and heptadecafluorodecyl (meth)acrylate.Examples of polyfunctional (meth)acrylic acid esters include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate.

[0086] Other polymerizable elements can be used alone or in combination of two or more.

[0087] The content of other polymerizable monomers is, for example, 20% by mass or less, preferably 10% by mass or less, and more preferably 0% by mass, relative to the polymerizable monomer. In other words, more preferably, the polymerizable monomer does not contain other polymerizable monomers and consists of styrene monomers.

[0088] The content of polymerizable monomers is, for example, 20% to 80% by mass, preferably 25% to 70% by mass, and more preferably 30% to 60% by mass, relative to the resin component.

[0089] (Shrinkage-reducing agent) A shrinkage-reducing agent is added as needed when obtaining a molded article using this unsaturated polyester resin composition, in order to suppress curing shrinkage and thermal shrinkage of the molded article and improve its appearance.

[0090] Examples of low-shrinkage agents include polyethylene, polystyrene, styrene-based thermoplastic elastomers, crosslinked polystyrene, polyvinyl acetate-polystyrene block copolymer, polyvinyl acetate, polymethyl methacrylate, and saturated polyester resins.

[0091] Shrinkage-reducing agents can be used alone or in combination of two or more types.

[0092] The content of the low-shrinkage agent is, for example, 10% by mass or less, preferably 5% by mass or less, more preferably 1% by mass or less, and even more preferably 0% by mass or less, relative to the resin component. In other words, even more preferably, the resin component does not contain a low-shrinkage agent and consists of an unsaturated polyester and a polymerizable monomer.

[0093] <Additives> The unsaturated polyester resin composition may contain additives as needed, to the extent that it does not impair the effects of the present invention.

[0094] Examples of additives include polymerization inhibitors, curing agents, curing accelerators, fillers, mold release agents, colorants, thickeners, flame retardants, wetting and dispersing agents, patterning agents, antibacterial agents, hydrophilic agents, photocatalysts, UV absorbers, UV stabilizers, separation inhibitors, silane coupling agents, antistatic agents, thixotropic agents, thixotropic stabilizers, and polymerization accelerators. Additives can be used individually or in combination of two or more.

[0095] (Polymerization inhibitors) Examples of polymerization inhibitors include hydroquinone compounds, benzoquinone compounds, catechol compounds, phenol compounds, and N-oxyl compounds. Hydroquinone compounds are preferred as polymerization inhibitors.

[0096] Polymerization inhibitors can be used alone or in combination of two or more types.

[0097] The polymerization inhibitor content is, for example, 0.001 to 0.050 parts by mass, preferably 0.005 to 0.020 parts by mass, per 100 parts by mass of the resin component.

[0098] (Curing agent) For curing the unsaturated polyester resin composition, peroxides can be used as curing agents (polymerization initiators). Examples of peroxides include methyl ethyl ketone peroxide, acetylacetone peroxide, cumene hydroxyperoxide, cyclohexanone peroxide, benzoyl peroxide, t-butyl peroxyisopropyl monocarbonate, t-amyl peroxyisopropyl monocarbonate, t-hexyl peroxyisopropyl monocarbonate, 1,1-bis(t-butyl peroxy)cyclohexane, t-butyl peroxy-2-ethylhexanoate, amyl peroxy-2-ethylhexanoate, 2-ethylhexyl peroxy-2-ethylhexanoate, t-butyl peroxybenzoate, t-hexyl peroxybenzoate, and t-hexyl peroxyacetate. The curing agents (polymerization initiators) can be used alone or in combination of two or more.

[0099] Such curing agents (polymerization initiators) are appropriately selected as official curing agents (polymerization initiators) depending on the application.

[0100] The content ratio of the curing agent (polymerization initiator) is, for example, 0.3 to 5 parts by mass, preferably 0.5 to 3 parts by mass, per 100 parts by mass of the resin component.

[0101] (Curing accelerators) Examples of curing accelerators include metal soaps and amine compounds.

[0102] Examples of metal soaps include cobalt soap (e.g., cobalt octenoate, cobalt naphthenate), manganese soap (e.g., manganese octenoate, manganese neodecanoate), and zinc soap (e.g., zinc octenoate).

[0103] Examples of amine compounds include N,N-substituted anilines (e.g., N,N-dimethylaniline, N,N-diethylaniline, etc.) and N,N-substituted p-toluidines (e.g., N,N-dihydroxyethyl-p-toluidine, etc.).

[0104] The hardening accelerator can be used alone or in combination of two or more types.

[0105] Preferably, the curing accelerator is a metal soap, more preferably a cobalt soap, and even more preferably cobalt octenoate.

[0106] The content ratio of the curing accelerator is, for example, 0.001 parts by mass to 5 parts by mass, preferably 0.01 parts by mass to 1.0 part by mass, per 100 parts by mass of the resin component. (Filler) Examples of fillers include inorganic fillers. Examples of inorganic fillers include oxides (e.g., alumina, titanium oxide), hydroxides (e.g., magnesium hydroxide, aluminum hydroxide), carbonates (e.g., calcium carbonate), sulfates (e.g., barium sulfate), silica (e.g., crystalline silica, fused silica, fumed silica, dry silica (aerosil)), hollow fillers, silicates (e.g., silica sand, diatomaceous earth, glass powder, glass balloons, glass flakes, mica, clay, kaolin, talc), fluorides (e.g., fluorite), phosphates (e.g., calcium phosphate), metal powders, ceramics, milled fibers, and clay minerals (e.g., smectite).

[0107] The fillers can be used individually or in combination of two or more types.

[0108] The filler content is, for example, 10 parts by mass or less, preferably 5 parts by mass or less, more preferably 1 part by mass or less, and even more preferably 0 parts by mass, per 100 parts by mass of the resin component. In other words, even more preferably, the unsaturated polyester resin composition does not contain filler. If the filler content is below the above upper limit, the flexibility can be improved.

[0109] <Preparation of Unsaturated Polyester Resin Composition> An unsaturated polyester resin composition is prepared by mixing a resin component with additives that are added as needed.

[0110] Furthermore, in the above preparation, an unsaturated polyester resin can also be prepared by first dissolving an unsaturated polyester in a polymerizable monomer and, if necessary, blending in the above-mentioned additives. The unsaturated polyester resin is an unsaturated polyester resin composition containing an unsaturated polyester and a polymerizable monomer.

[0111] In the preparation of the unsaturated polyester resin, the content of the polymerizable monomer is, for example, 10 to 100 parts by mass per 100 parts by mass of unsaturated polyester.

[0112] Furthermore, in the preparation of unsaturated polyester resins, the above-mentioned additives (preferably polymerization inhibitors) may also be incorporated.

[0113] Furthermore, after preparing the unsaturated polyester resin, polymerizable monomers can also be added when mixing this unsaturated polyester resin with additives.

[0114] This is used to prepare an unsaturated polyester resin composition.

[0115] 2. Molding material The molding material comprises an unsaturated polyester resin composition.

[0116] The molding material may also contain reinforcing fibers as needed.

[0117] Examples of reinforcing fibers include inorganic fibers, organic fibers, and natural fibers. Examples of inorganic fibers include glass fibers, carbon fibers, metal fibers, and ceramic fibers. Examples of organic fibers include polyvinyl alcohol-based fibers, polyester-based fibers, polyamide-based fibers, fluororesin-based fibers, and phenol-based fibers. Examples of natural fibers include hemp and kenaf.

[0118] The reinforcing fibers can take the following forms, for example: cloth (e.g., roving cloth), mat (e.g., chopped strand mat, preformable mat, continuous strand mat, and surfacing mat), strand, roving, nonwoven, and paper forms.

[0119] The length of the reinforcing fibers is not particularly limited, but is, for example, 1.5 mm to 80 mm, preferably 3 mm to 40 mm, more preferably 5 mm to 20 mm, and even more preferably 6 mm to 10 mm.

[0120] The reinforcing fiber content is, for example, 50% by mass or less, preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 1% by mass or less, and particularly preferably 0% by mass, relative to the total amount of the unsaturated polyester resin composition and reinforcing fibers. In other words, particularly preferably, the molding material does not contain reinforcing fibers. If the reinforcing fiber content is below the above upper limit, the flexibility can be improved.

[0121] <Preparation of Molding Material> In the preparation of the molding material, if the molding material does not contain reinforcing fibers, the unsaturated polyester resin composition is prepared as is as the molding material.

[0122] On the other hand, if the molding material contains reinforcing fibers, the reinforcing fibers are blended into the unsaturated polyester resin composition. Specifically, the reinforcing fibers are impregnated with the unsaturated polyester resin composition. In such cases, examples of methods for preparing the molding material include SMC (sheet molding compound), TMC (thick molding compound), and BMC (bulk molding compound).

[0123] The molding material is prepared according to the above.

[0124] 3. Molded products: Molded products include cured products of the molding material.

[0125] Molded products are manufactured by molding the molding material using methods such as room temperature casting, heat compression molding, spray-up molding, and hand lay-up molding.

[0126] In room temperature casting, the unsaturated polyester resin composition (molding material) is pre-mixed with a curing agent and an accelerator, and the molding material is injected into a metal mold or FRP mold and allowed to cure. The conditions for room temperature casting are set appropriately according to the purpose and application, but for example, the material is left to stand at 23°C (room temperature) for 24 hours, and then after-curing is performed at 40°C for about 2 hours to obtain the molded product.

[0127] In the case of heat compression molding, the conditions are set appropriately according to the purpose and application. In heat compression molding, the molding temperature is, for example, 100°C to 200°C. The molding pressure is, for example, 0.1 MPa to 20 MPa, preferably 1 MPa to 15 MPa, and more preferably 5 MPa to 12 MPa.

[0128] This allows the molding material to be shaped and cured, resulting in a molded product.

[0129] The thickness of the molded product is, for example, 0.2 mm to 120.0 mm, preferably 0.5 mm to 100.0 mm.

[0130] 4. Effects: In the unsaturated polyester resin composition, the ethylenically unsaturated bond-free polybasic acid includes a saturated aliphatic dibasic acid with 7 or more carbon atoms, and the content of the saturated aliphatic dibasic acid with 7 or more carbon atoms is 30 mol% or more relative to the ethylenically unsaturated bond-free polybasic acid. Therefore, water resistance can be improved.

[0131] Furthermore, in the unsaturated polyester resin composition, the polybasic acid and / or polyhydric alcohol have an aromatic ring. Therefore, solubility in styrene monomers can be improved.

[0132] The molded product includes a cured product of a molding material containing the above-mentioned unsaturated polyester resin composition. Therefore, water resistance can be improved.

[0133] Such molded products can be used alone or partially blended with existing resins for each application in FRP applications that include reinforcing fibers, such as construction materials like corrugated and flat sheets, waterproof linings, and pipe rehabilitation; housing equipment such as bathroom units, bathtubs, septic tanks, toilet tanks, system kitchens, and wall materials; transportation equipment such as boats, ships, automobiles, and vehicles; corrosion-resistant materials such as tanks, containers, and corrosion-resistant linings; industrial equipment such as pipes, housings, laminates, and electrical components; and general merchandise.

[0134] The present invention will be described in further detail below with reference to examples. However, the following description represents one embodiment of the present invention, and the present invention is not limited to these descriptions.

[0135] The specific numerical values ​​such as blending ratios (content percentages), physical properties, and parameters used in the following description can be replaced with the corresponding upper limits (values ​​defined as "less than or equal to" or "less than") or lower limits (values ​​defined as "greater than or equal to" or "greater than") of the blending ratios (content percentages), physical properties, and parameters described in the "Modes for Carrying Out the Invention" section above. Furthermore, unless otherwise specified in the following description, "parts" and "%" refer to mass.

[0136] <Details of Components> The components used in each example and each comparative example are described in detail below. Bisphenol A-2,3PO adduct: Propylene oxide adduct of bisphenol A, average number of moles of propylene oxide added: 2.3 moles Bisphenol A-4EO adduct: Ethylene oxide adduct of bisphenol A, average number of moles of ethylene oxide added: 4.0 moles

[0137] <Preparation of Unsaturated Polyester Resin Composition (Molding Material) and Molded Articles> Example 1 (Preparation of Unsaturated Polyester Resin Composition (Molding Material)) A flask equipped with a thermometer, nitrogen gas inlet tube, reflux condenser, and stirrer was used as the reactor. 23 mol of isophthalic acid and 98 mol of propylene glycol were charged into this reactor and a polycondensation reaction was carried out at a temperature of 200-210°C with stirring under a nitrogen gas atmosphere. When the acid value reached 10 mg KOH / g, it was cooled to 100°C, 60 mol of sebacic acid and 17 mol of fumaric acid were charged, and the reaction was carried out again at 210-220°C for 8 hours to obtain an unsaturated polyester with an acid value of 25 mg KOH / g.

[0138] Next, the obtained unsaturated polyester was mixed with styrene and a polymerization inhibitor. This yielded an unsaturated polyester resin composition (molding material) containing the unsaturated polyester resin (solids content concentration 68% by mass).

[0139] (Preparation of molded product) An unsaturated polyester resin composition (molding material) was mixed with a curing agent (Permec N, manufactured by NOF Corporation) and an accelerator (cobalt octoate, manufactured by Nippon Chemical Industrial Co., Ltd.). Then, a 3 mm thick U-shaped spacer was placed between glass plates coated with a release agent (Daifree GA-9700, manufactured by Daikin Corporation) and fixed in place. The above unsaturated polyester resin composition (molding material) was then injected and cured. After that, an after-curing period was carried out at 40°C for 24 hours to obtain a molded product.

[0140] Examples 2 to 5 and Comparative Examples 1 to 5: Unsaturated polyester resin compositions (molding materials) and molded articles were produced using the same procedure as in Example 1. However, the formulations of each component were changed based on the information in Table 1. In Table 1, the values ​​for polymerizable monomers indicate the percentage of polymerizable monomers in relation to the resin components.

[0141] <Evaluation> [Water Resistance] (Before hot water treatment) Tensile strength and elongation were measured for molded products of each example and comparative example. Specifically, samples were prepared according to the tensile test specimen of laminated board shown in Figure 31 of JIS K6911 (1995). Measurements were performed using a universal tensile testing machine at an ambient temperature of 23°C and a tensile speed of 100 mm / min. The results are shown in Table 1.

[0142] (After hot water treatment) The molded articles of each example and comparative example were immersed in 90°C hot water for 120 hours. After that, the tensile strength and elongation of the molded articles were measured according to the same procedure. The retention rate of tensile strength and elongation was also calculated.

[0143] The water resistance was evaluated based on the following criteria. The results are shown in Table 1. {Criteria} A: The elongation retention rate was 90% or higher. B: The elongation retention rate was 50% or higher but less than 90%. C: The elongation retention rate was 10% or higher but less than 50%. D: The elongation retention rate was less than 10%.

[0144] [Solubility to Styrene Monomers] The solubility of unsaturated polyesters in the unsaturated polyester resin compositions of each example and comparative example was observed visually. The solubility to styrene monomers was evaluated based on the following criteria. The results are shown in Table 1. {Criteria} A: No turbidity was observed. B: Slight turbidity was observed. C: Turbidity or separation was observed. Regarding solubility, a B rating is considered to be practically acceptable.

[0145] <Discussion> Examples 1, 3, 4 and Comparative Example 1 all use 1,2-propanediol of similar proportions. Examples 1, 3, and 4, in which the polybasic acid has an aromatic ring, show improved solubility in styrene monomers compared to Comparative Example 1, in which the polybasic acid and polyhydric alcohol do not have aromatic rings.

[0146]

[0147]

[0148] The above invention is provided as an illustrative embodiment of the present invention, but this is merely illustrative and should not be interpreted restrictively. Modifications of the present invention that are obvious to those skilled in the art are included in the claims below.

[0149] The unsaturated polyester resin composition and molded articles of the present invention can be used alone or partially blended with existing resins for each application in the manufacture of non-FRP products that do not contain reinforcing fibers, such as in the production of construction materials such as corrugated and flat sheets, waterproof linings and pipe rehabilitation; housing equipment such as bathroom units, bathtubs, septic tanks and toilet tanks, system kitchens and wall materials; transportation equipment such as boats, ships and automobiles and vehicles; corrosion-resistant materials such as tanks and containers and corrosion-resistant linings; industrial equipment such as pipes, housings, laminates and electrical components; and miscellaneous goods.

Claims

1. An unsaturated polyester resin composition comprising a resin component containing an unsaturated polyester and a polymerizable monomer, wherein the unsaturated polyester is a reaction product of a polybasic acid and a polyhydric alcohol, the polybasic acid comprises an ethylenically unsaturated bond-containing polybasic acid and an ethylenically unsaturated bond-free polybasic acid, the ethylenically unsaturated bond-free polybasic acid comprises a saturated aliphatic polybasic acid having 7 or more carbon atoms, the content of the saturated aliphatic polybasic acid having 7 or more carbon atoms is 30 mol% or more with respect to 100 mol% of the ethylenically unsaturated bond-free polybasic acid, the polybasic acid and / or the polyhydric alcohol has an aromatic ring, and the polymerizable monomer comprises a styrene monomer.

2. The unsaturated polyester resin composition according to claim 1, wherein the ethylenically unsaturated bond-free polybasic acid has an aromatic ring.

3. The unsaturated polyester resin composition according to claim 1, wherein the molar ratio of the ethylenically unsaturated polybasic acid to the ethylenically unsaturated polybasic acid is 2.5 or more.

4. The unsaturated polyester resin composition according to claim 1, wherein the polyhydric alcohol comprises a branched aliphatic alcohol.

5. A molded article comprising a cured product of a molding material containing the unsaturated polyester resin composition described in any one of claims 1 to 4.

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