Resin composition and molded article of the same

Abstract

To provide a resin composition from which a molded article having excellent hydrolysis resistance and mechanical strength can be obtained, and a molded article of the same.SOLUTION: A resin composition contains a polyalkylene terephthalate resin-impregnated glass fiber bundle (X) in which a fiber bundle (A) where glass fibers (a1) are aligned in a length direction is impregnated with a polyalkylene terephthalate resin (B), wherein the fiber bundle (A) contains a sizing agent (a2) containing a polymer containing at least one constitutional unit selected from a carboxylic acid-derived constitutional unit, and a carboxylic acid anhydride-derived constitutional unit, and an epoxy resin.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a resin composition and a molded article thereof.

Background Art

[0002] Polyester resins such as polyalkylene terephthalate resins are excellent in mechanical properties, electrical properties, heat resistance, moldability, etc. These polyester resins are known to further improve their mechanical properties and heat resistance particularly when combined with inorganic fillers such as glass fibers. Such glass fiber-containing polyester resin compositions are widely used in various fields such as automotive parts, parts for electric and electronic devices, and parts for precision instruments. On the other hand, since polyester resins have ester groups in their molecules, hydrolysis easily occurs in a high-temperature and high-humidity environment. In automotive parts where environmental changes are large, improvement of hydrolysis resistance is always desired.

[0003] As a method for improving the hydrolysis resistance of the polyester resin itself, it is known to blend an epoxy compound or a carbodiimide compound. For example, Patent Document 1 shows that the hydrolysis resistance is improved by blending an epoxy compound with polybutylene terephthalate having a specific terminal carboxyl group concentration and intrinsic viscosity. Also, improvement of the hydrolysis resistance of glass fiber-containing polyester resin compositions has been carried out by treating the surface of glass fibers blended as an inorganic filler. For example, Patent Document 2 proposes a polyester resin composition containing glass fibers surface-treated with a surface treatment agent containing a novolac-type epoxy resin.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the conventional glass fiber-containing polyester resin composition still has insufficient hydrolysis resistance and there is room for improvement in mechanical strength.

[0006] The present application has been made in view of the above circumstances, and an object thereof is to provide a resin composition capable of obtaining a molded article excellent in hydrolysis resistance and having good mechanical strength, and a molded article thereof.

Means for Solving the Problems

[0007] As a result of intensive studies, the inventors of the present application have found that a resin composition containing a polyalkylene terephthalate resin-impregnated glass fiber bundle (X) in which a fiber bundle (A) with glass fibers (a1) aligned in the length direction is impregnated with a polyalkylene terephthalate resin (B), and the fiber bundle (A) contains a polymer containing at least one structural unit selected from a structural unit derived from a carboxylic acid and a structural unit derived from a carboxylic anhydride, and a sizing agent (a2) containing an epoxy resin can solve the above-mentioned problems.

Effects of the Invention

[0008] According to the present invention, it is possible to provide a resin composition capable of obtaining a molded article excellent in hydrolysis resistance and having good mechanical strength, and a molded article thereof.

Modes for Carrying Out the Invention

[0009] Hereinafter, an embodiment of the present disclosure will be described in detail. However, the scope of the present disclosure is not limited to the embodiment described here, and various modifications can be made without departing from the spirit of the present disclosure. Each aspect disclosed in this specification can be combined with any other feature disclosed in this specification. Also, when a plurality of upper limit values and lower limit values are described for a specific parameter, any upper limit value and lower limit value among these can be combined to form a suitable numerical range. Further, the lower limit value and / or upper limit value of the numerical range described in the present disclosure can be replaced with a numerical value within that numerical range and shown in the examples. The expression "α~β" indicating a numerical range means "α or more and β or less". When a specific description given for one embodiment also applies to other embodiments, the description may be omitted in other embodiments.

[0010] Each configuration and their combinations in each embodiment are examples, and within the scope not departing from the gist of the present disclosure, addition, omission, substitution, and other changes of the configuration can be made as appropriate. The present disclosure is not limited by the embodiments. Each aspect disclosed in this specification can be combined with any other feature disclosed in this specification.

[0011] [Resin Composition] The first embodiment in the present disclosure relates to a resin composition. The first embodiment is a resin composition, wherein the resin composition contains a polyalkylene terephthalate resin-impregnated glass fiber bundle (X) in which a fiber bundle (A) with glass fibers (a1) aligned in the length direction is impregnated with a polyalkylene terephthalate resin (B), and the fiber bundle (A) contains a polymer containing at least one structural unit selected from a structural unit derived from a carboxylic acid and a structural unit derived from a carboxylic anhydride, and a sizing agent (a2) containing an epoxy resin. The resin composition according to the first embodiment is excellent in hydrolysis resistance and can obtain a molded product with good mechanical strength.

[0012] <Glass fiber bundle (X) impregnated with polyalkylene terephthalate resin> The resin composition according to the first embodiment includes a glass fiber bundle (X) impregnated with a polyalkylene terephthalate resin (hereinafter referred to as "resin-impregnated fiber bundle (X)"). By including the resin-impregnated fiber bundle (X) in the resin composition according to the first embodiment, the above problems can be solved.

[0013] The resin-impregnated fiber bundle (X) is a composite material obtained by impregnating a fiber bundle (A) in which glass fibers (a1) are aligned in the longitudinal direction with a polyalkylene terephthalate resin (B) (hereinafter sometimes referred to as "resin (B)") and then cutting. The fiber bundle (A) further includes a sizing agent (a2) containing a polymer containing at least one structural unit selected from a structural unit derived from a carboxylic acid and a structural unit derived from a carboxylic anhydride, and an epoxy resin. In one embodiment, the resin composition may include only the resin-impregnated fiber bundle (X).

[0014] (Fiber bundle (A)) The resin-impregnated fiber bundle (X) includes a fiber bundle (A) containing glass fibers (a1) and a sizing agent (a2). By impregnating such a fiber bundle (A) with a polyalkylene terephthalate resin (B), the effect of improving mechanical strength can be obtained, and furthermore, the hydrolysis resistance of the molded product is also improved.

[0015] In the present disclosure, the fiber bundle (A) includes "a fiber bundle in which a part or all of the surface is covered with a sizing agent (a2) and glass fibers (a1) are aligned in the longitudinal direction", "a fiber bundle in which the voids of the fibers are filled with a sizing agent (a2) and glass fibers (a1) are aligned in the longitudinal direction", and "a fiber bundle in which a part or all of the surface of a fiber bundle in which glass fibers (a1) are aligned in the longitudinal direction is covered with a sizing agent (a2)". In these embodiments, the sizing agent (a2) may react with the components constituting the glass fibers (a1). Also, "glass fibers (a1)" refers to glass monofilaments. Preferably, a fiber bundle in which part or all of the surface is coated with a sizing agent (a2) and the glass fibers (a1) are aligned in the longitudinal direction, and / or a fiber bundle in which the glass fibers (a1) are aligned in the longitudinal direction, and part or all of the surface is coated with a sizing agent (a2). More preferably, in the resin-impregnated fiber bundle (X), the sizing agent (a2) is present at the interface between the glass fiber (a1) and the polybutylene alkylene terephthalate resin (B). Such a fiber bundle (A) may be obtained by applying a sizing agent (a2) to the glass fiber (a1) and gathering and winding a predetermined number of the glass fibers (a1) coated with the sizing agent (a2).

[0016] In one embodiment, the content of the fiber bundle (A) with respect to the total mass of the resin-impregnated fiber bundle (X) is preferably 5 to 70% by mass, more preferably 10 to 60% by mass, still more preferably 20 to 55% by mass, and particularly preferably 30 to 50% by mass.

[0017] (Glass fiber (a1)) The type of the glass fiber (a1) is not particularly limited, but in terms of quality, E-glass fibers or corrosion-resistant glass fibers containing zirconium elements in the composition are preferably used.

[0018] ·Average fiber diameter In one embodiment, the average fiber diameter of the glass fiber (a1) is preferably 5 to 20 μm, more preferably 8 to 20 μm, and still more preferably 10 to 18 μm. When the average fiber diameter is within the above range, the balance between productivity and mechanical properties is likely to be good. The average fiber diameter of the glass fiber (a1) is the average value of the fiber diameters measured for about 100 of the fibers by observing the glass fiber (a1) of the ash residue obtained by heating the resin composition (or the resin-impregnated fiber bundle (X)) at 600 °C for 2 hours.

[0019] ·Average fiber length In one embodiment, the average fiber length of the glass fibers (a1) in the fiber bundle (A) is preferably 5 to 30 mm, more preferably 5 to 20 mm, and even more preferably 6 to 15 mm. By impregnating the fiber bundle (A) containing the glass fibers (a1) with an average fiber length of 5 to 30 mm and the sizing agent (a2) with the polyalkylene terephthalate resin (B), a molded article excellent in hydrolysis resistance and even more excellent in mechanical strength can be easily obtained. The average fiber length of the glass fibers (a1) can be calculated from the average value obtained by measuring the lengths of the major axes of about 100 pellets of the resin-impregnated fiber bundle (X) with a caliper or the like. Further, when the resin composition contains the resin-impregnated fiber bundle (X) and other thermoplastic resins, the average fiber length of the glass fibers (a1) in the resin composition is also preferably in the above range. The average fiber length of the glass fibers (a1) in the resin composition can be calculated as the average value of the fiber lengths measured by heating the resin composition at 600 °C for 2 hours to obtain an ash residue, dispersing the glass fibers (a1) of this ash residue in a medium, and performing image processing on the fibers.

[0020] In one embodiment, as the glass fibers (a1), either those having a circular cross-section or those having a non-circular cross-section can be used. Examples of the non-circular cross-section include an oval shape, an elliptical shape, and a cocoon shape. The shape ratio (major axis diameter: minor axis diameter) of the non-circular cross-section is not particularly limited, but is preferably 1.5:1 to 6:1, more preferably 2:1 to 5:1, and even more preferably 2.5:1 to 4:1. When the shape ratio is in the range of 1.5:1 to 6:1, by flattening the cross-section, effects such as dimensional stability and warp reduction of the molded article can be easily obtained. Further, it is also easy to suppress the excessive flattening and the easy breakage of the glass fibers (a1), and as a result, the strength of the molded article is reduced.

[0021] The glass fibers (a1) may be used alone or in combination of two or more. When combining two or more types of glass fibers (a1), glass fibers (a1) having different fiber cross-sections may be combined, or glass fibers (a1) having different average fiber diameters may be combined.

[0022] In one embodiment, the number of glass fibers (a1) in the fiber bundle (A) can be adjusted in consideration of the outer diameter (major axis length and minor axis length) of the fiber bundle (A). For example, the number of glass fibers (a1) may be 100 to 30,000, may be 1,000 to 24,000, or may be 2,000 to 12,000.

[0023] (Sizing agent (a2)) The fiber bundle (A) contains a sizing agent (a2) including a polymer containing at least one structural unit selected from a structural unit derived from a carboxylic acid and a structural unit derived from a carboxylic anhydride, and an epoxy resin. The inventors of the present application have found that in the fiber bundle (A), since the sizing agent (a2) contains both a polymer containing a specific structural unit and an epoxy resin, the hydrolysis resistance of the molded article obtained from the resin composition according to the first embodiment is improved, and further the mechanical strength is significantly improved. In particular, the molded article is likely to have improved flexural strength and Charpy impact strength.

[0024] ·A polymer containing at least one structural unit selected from a structural unit derived from a carboxylic acid and a structural unit derived from a carboxylic anhydride The sizing agent (a2) contains a polymer (hereinafter simply referred to as "polymer") containing at least one structural unit selected from a structural unit derived from a carboxylic acid and a structural unit derived from a carboxylic anhydride.

[0025] Examples of the carboxylic acid capable of constituting the structural unit derived from a carboxylic acid contained in the polymer include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, fumaric acid, maleic acid, succinic acid, cinnamic acid, itaconic acid, mesaconic acid, and citraconic acid. These unsaturated carboxylic acids may have substituents. The polymer can contain one or more structural units derived from these unsaturated carboxylic acids.

[0026] Examples of the carboxylic anhydrides that can form the structural units derived from carboxylic anhydrides contained in the polymer include unsaturated carboxylic anhydrides such as maleic anhydride, itaconic anhydride, succinic anhydride, phthalic anhydride, glutaric anhydride, dodecenyl succinic anhydride, and chlorendic anhydride. These unsaturated carboxylic anhydrides may have substituents. The polymer can contain one or more structural units derived from these unsaturated carboxylic anhydrides.

[0027] In one embodiment, from the viewpoint of easily obtaining a molded article with excellent hydrolysis resistance, it is preferable that the polymer contains a structural unit derived from a carboxylic anhydride, and more preferably contains a structural unit derived from maleic anhydride.

[0028] The polymer may be a homopolymer of one type of carboxylic acid or carboxylic anhydride, or may be a copolymer of two or more types of carboxylic acids and / or carboxylic anhydrides.

[0029] In one embodiment, the polymer can contain other constitutional units other than at least one constitutional unit selected from constitutional units derived from carboxylic acids and constitutional units derived from carboxylic anhydrides. The other constitutional units are not particularly limited as long as they are constitutional units derived from monomers copolymerizable with the aforementioned carboxylic acids and / or carboxylic anhydrides. In one embodiment, the other constitutional units can include unsaturated monomers such as styrene monomers, butadiene, acrylonitrile, vinyl acetate, (meth)acrylic acid esters, olefins having 2 to 6 carbon atoms, and vinyl ethers. The polymer can contain one or more other constitutional units derived from these unsaturated monomers. Among these, from the viewpoint of easily obtaining a molded article having excellent hydrolysis resistance and mechanical strength, it is preferable to contain a (meth)acrylic acid ester, more preferably to contain at least one (meth)acrylic acid ester selected from methyl acrylate, methyl methacrylate, ethyl acrylate, and ethyl methacrylate, and even more preferably to contain methyl acrylate and / or methyl methacrylate. In a preferred embodiment, the polymer is a copolymer of a carboxylic anhydride, methyl acrylate, and methyl methacrylate. The mass ratio of the carboxylic anhydride, methyl acrylate, and methyl methacrylate is not particularly limited.

[0030] In one embodiment, the weight average molecular weight of the polymer is not particularly limited, but is preferably from 10,000 to 1,000,000. If the weight average molecular weight of the polymer is within the range of 10,000 to 1,000,000, it is easy to obtain a molded article having sufficient hydrolysis resistance, and it is easy for the sizing agent (a2) to adhere (and / or coat) to the surface of the glass fiber (a1). The weight average molecular weight of the polymer can be measured by SEC (size exclusion chromatography).

[0031] ·Epoxy resin The bundling agent (a2) further contains an epoxy resin. Examples of the epoxy resin include glycidyl ether type epoxy resins, glycidyl ester type epoxy resins (e.g., diglycidyl phthalate, diglycidyl tetrahydrophthalate, diglycidyl hexahydrophthalate, dimethyl glycidyl phthalate, dimethyl glycidyl hexahydrophthalate, dimer acid glycidyl ester, aromatic diglycidyl ester, cycloaliphatic diglycidyl ester, etc.), glycidyl amine type epoxy resins (e.g., tetraglycidyl diaminodiphenylmethane, triglycidyl - para - aminophenol, triglycidyl - meta - aminophenol, diglycidyl toluidine, tetraglycidyl metaxylylenediamine, diglycidyl tribromoaniline, tetraglycidyl bisaminomethylcyclohexane, etc.), heterocyclic epoxy resins (e.g., triglycidyl isocyanurate (TGIC), hydantoin type epoxy resins, etc.), cycloaliphatic epoxy resins (e.g., vinylcyclohexene dioxide, dicyclopentadiene monoxide, alicyclic diepoxy acetal, alicyclic diepoxy adipate, alicyclic diepoxy carboxylate, etc.), epoxidized polybutadiene, and the like.

[0032] The glycidyl ether type epoxy resins include glycidyl ethers of polyhydroxy compounds, novolak type epoxy resins, and the like.

[0033] Examples of the glycidyl ethers of polyhydroxy compounds include glycidyl ethers of aromatic polyhydroxy compounds such as bisphenol type epoxy resins (e.g., bisphenol A type, bisphenol AD type, or bisphenol F type epoxy resins, etc.), resorcin type epoxy resins; and aliphatic epoxy resins (e.g., glycidyl ethers of alkylene glycols and polyoxyalkylene glycols, etc.).

[0034] Examples of the novolak type epoxy resins include phenol novolak type epoxy resins, cresol novolak type epoxy resins, and the like.

[0035] In one embodiment, as the epoxy resin, aromatic epoxy resins such as bisphenol type epoxy resin, resorcin type epoxy resin, and phenol novolac type epoxy resin, and cycloaliphatic epoxy resin are preferable, and it is more preferable to contain bisphenol type epoxy resin and / or phenol novolac type epoxy resin.

[0036] The epoxy equivalent of the epoxy resin is preferably 100 to 1600 g / eq, more preferably 100 to 800 g / eq, and still more preferably 150 to 500 g / eq.

[0037] The number average molecular weight of the epoxy resin is preferably 200 to 50,000, more preferably 300 to 10,000, and still more preferably 400 to 6,000. The number average molecular weight of the epoxy resin can be measured by SEC.

[0038] In one embodiment, from the viewpoint that the mechanical strength of the molded product is more likely to be improved, the mass ratio of the polymer to the mass ratio of the epoxy resin in the sizing agent (a2) (polymer / epoxy resin) is preferably 0.001 to 1.500.

[0039] The ratio of the sizing agent (a2) is preferably 0.1 to 3.0% by mass, more preferably 0.3 to 2.5% by mass, based on the total mass of the fiber bundle (A). If the ratio of the sizing agent (a2) in the fiber bundle (A) is within the above range, the hydrolysis resistance of the molded product is more likely to be improved.

[0040] In addition to the above polymer and epoxy resin, the sizing agent (a2) may contain optional components such as urethane resin, silane coupling agent, lubricant, nonionic surfactant, antistatic agent, etc., and the blending ratio of each component can be determined as needed.

[0041] The urethane resin contributes to the bundling property and dispersibility of the glass fiber (a1), and is a resin obtained from the reaction of polyisocyanate and polyol. As the silane coupling agent, aminosilane, epoxysilane, chlorosilane, mercaptosilane, vinylsilane, acrylsilane, etc. can be used. As the lubricant, fatty acid amide, quaternary ammonium salt, etc. can be used. In addition, as the nonionic surfactant, synthetic alcohol type, natural alcohol type, fatty acid ester type, etc. can be used. The aggregating agent (a2) can contain one or more of the above-mentioned optional components.

[0042] In one embodiment, the ratio of the aggregating agent (a2) to the total mass of the resin-impregnated fiber bundle (X) is preferably 0.03 to 1.5% by mass, more preferably 0.09 to 1.25% by mass. If the ratio of the aggregating agent (a2) in the resin-impregnated fiber bundle (X) is within the above range, the hydrolysis resistance of the molded product is likely to be good, and the mechanical strength is also likely to be improved.

[0043] <Polyalkylene terephthalate resin (B)> The resin-impregnated fiber bundle (X) contains a polyalkylene terephthalate resin (B). The resin (B) is a thermoplastic polyester resin obtained by the reaction of a dicarboxylic acid component mainly composed of a dicarboxylic acid compound and / or its ester-forming derivative and a diol component mainly composed of a diol compound and / or its ester-forming derivative. Among them, the dicarboxylic acid component is mainly composed of terephthalic acid and / or its ester-forming derivative, and the diol component is mainly composed of alkylene glycol and / or its ester-forming derivative. The resin (B) can contain a dicarboxylic acid component and a diol component other than the main components. As other copolymerizable monomers, copolyesters combined with an oxycarboxylic acid component, a lactone component, etc. (hereinafter sometimes referred to as copolymerizable monomers) can also be used.

[0044] Examples of dicarboxylic acid components other than the main components include aliphatic dicarboxylic acids (for example, dicarboxylic acids having about 4 to 40 carbon atoms such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, hexadecanedicarboxylic acid, dimer acid, preferably dicarboxylic acids having about 4 to 14 carbon atoms), alicyclic dicarboxylic acids (for example, dicarboxylic acids having about 4 to 40 carbon atoms such as hexahydrophthalic acid, hexahydroisophthalic acid, hexahydroterephthalic acid, himic acid, preferably dicarboxylic acids having about 8 to 12 carbon atoms), aromatic dicarboxylic acids other than terephthalic acid (for example, naphthalenedicarboxylic acids such as phthalic acid, isophthalic acid, methylisophthalic acid, methylterephthalic acid, 2,6-naphthalenedicarboxylic acid; dicarboxylic acids having about 8 to 16 carbon atoms such as 4,4'-biphenyldicarboxylic acid, 4,4'-diphenoxyetherdicarboxylic acid, 4,4'-dihydroxybenzoic acid, 4,4'-diphenylmethanedicarboxylic acid, 4,4'-diphenylketonedicarboxylic acid), or derivatives thereof (for example, ester-forming derivatives such as lower alkyl esters, aryl esters, acid anhydrides). Preferred dicarboxylic acid components for use in combination with terephthalic acid include isophthalic acid, naphthalenedicarboxylic acid, etc., and these can also be used in combination of two or more. However, it is preferable that the aromatic dicarboxylic acid compound is contained in an amount of 50 mol% or more, more preferably 80 mol% or more, and particularly preferably 90 mol% or more, based on the total amount of the dicarboxylic acid components contained as copolymerizable monomers. Further, if necessary, polyvalent carboxylic acids such as trimellitic acid, pyromellitic acid or ester-forming derivatives thereof (such as alcohol esters) may be used in combination. By using such polyfunctional compounds in combination, a branched resin (B) can also be obtained.

[0045] Examples of the diol component other than the main component include aliphatic alkanediols (e.g., aliphatic diols having about 2 to 12 carbon atoms such as ethylene glycol, trimethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, neopentyl glycol, hexanediol, octanediol, decanediol, preferably aliphatic diols having about 2 to 10 carbon atoms (excluding the aliphatic alkanediol used as the main component)), polyoxyalkylene glycols (glycols having a plurality of oxyalkylene units having about 2 to 4 carbon atoms, e.g., diethylene glycol, dipropylene glycol, ditetramethylene glycol, triethylene glycol, tripropylene glycol, polytetramethylene glycol, etc.), alicyclic diols (e.g., 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.). Further, aromatic diols such as hydroquinone, resorcinol, bisphenol, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis-(4-(2-hydroxyethoxy)phenyl)propane, xylylene glycol may be used in combination. However, it is preferable that the alkylene glycol is contained in an amount of 50 mol% or more, more preferably 80 mol% or more, and particularly preferably 90 mol% or more based on the total amount of the diol component contained as the copolymerizable monomer. Further, if necessary, polyols such as glycerin, trimethylolpropane, trimethylolethane, pentaerythritol or their ester-forming derivatives may be used in combination. By using such polyfunctional compounds in combination, a branched resin (B) can also be obtained.

[0046] Examples of the oxycarboxylic acid (or oxycarboxylic acid component or oxycarboxylic acids) include oxycarboxylic acids such as oxybenzoic acid, oxynaphthoic acid, hydroxyphenylacetic acid, glycolic acid, oxycaproic acid, or their derivatives.

[0047] Examples of the lactone include lactones having 3 to 12 carbon atoms such as propiolactone, butyrolactone, valerolactone, caprolactone (e.g., ε-caprolactone, etc.).

[0048] In one embodiment, when the resin (B) is a copolyester, the proportion of the copolymerizable monomer in the copolyester is preferably in the range of 0.01 to 30 mol%, more preferably 1 to 25 mol%, still more preferably 3 to 20 mol%, and particularly preferably 5 to 15 mol%. Further, when a homopolyester and a copolyester are used in combination, the proportion of the homopolyester and the copolyester is preferably in the range such that the proportion of the copolymerizable monomer is 0.01 to 30 mol% with respect to the total amount of all monomers. More preferably, it is 1 to 25 mol%, still more preferably 3 to 20 mol%, and particularly preferably 5 to 15 mol%. In one embodiment, the homopolyester / copolyester (mass ratio) can be blended so as to be 99 / 1 to 1 / 99, preferably 95 / 5 to 5 / 95 (mass ratio), and still more preferably 90 / 10 to 10 / 90 (mass ratio).

[0049] In a preferred embodiment, the resin (B) is a homopolyester or copolyester having an alkylene terephthalate unit as a main component (for example, 50 to 100 mol%, preferably about 75 to 100 mol%). For example, homopolyesters such as polyethylene terephthalate (PET) resin, polytrimethylene terephthalate (PTT) resin, polybutylene terephthalate (PBT) resin; copolyesters containing an alkylene isophthalate unit as a copolymerization component with an alkylene terephthalate unit as a main component; copolyesters containing an alkylene naphthalate unit as a copolymerization component with an alkylene terephthalate unit as a main component, etc. are included. These can be used alone or in combination of two or more. In a more preferred embodiment, the resin (B) contains a PBT resin. In a particularly preferred embodiment, the resin (B) is a PBT resin. In a preferred embodiment, the resin composition contains only a polyalkylene terephthalate resin as a thermoplastic resin.

[0050] ·Amount of carboxylic acid terminal groups The amount of carboxylic acid end groups in resin (B) is not particularly limited as long as it does not inhibit the effects of the resin composition according to the first embodiment. In one embodiment, the amount of carboxylic acid end groups in resin (B) is preferably 3 to 33 meq / kg, more preferably 5 to 33 meq / kg, and even more preferably 7 to 33 meq / kg. If the amount of carboxylic acid end groups in resin (B) is in the range of 3 to 33 meq / kg, the adhesion between glass fiber (A) and resin (B) tends to be good. Also, the hydrolysis resistance of the resulting molded product tends to be good. In a preferred embodiment, resin (B) is a PBT resin having a carboxylic acid end group amount of 3 to 33 meq / kg. The amount of carboxylic acid end groups in resin (B) can be measured by titrating a pulverized sample of the pellets of resin (B) obtained by polymerization with a 0.01N aqueous sodium hydroxide solution after dissolving it by heating at 215°C for 10 minutes in benzyl alcohol.

[0051] ·Intrinsic viscosity The intrinsic viscosity of resin (B) is not particularly limited as long as it does not inhibit the effects of the resin composition according to the first embodiment. In one embodiment, the intrinsic viscosity of resin (B) is preferably 0.6 to 1.3 dL / g from the viewpoint of moldability, and more preferably 0.7 to 1.2 dL / g. If the intrinsic viscosity of the PAT resin is 0.6 to 1.3 dL / g, the resulting resin composition is likely to be particularly excellent in moldability. Also, the intrinsic viscosity can be adjusted by blending two or more resins (B) having different intrinsic viscosities. For example, a resin (B) having an intrinsic viscosity of 0.78 dL / g can be prepared by blending a resin (B) having an intrinsic viscosity of 0.69 dL / g and a resin (B) having an intrinsic viscosity of 0.88 dL / g. In a more preferred embodiment, resin (B) is a PBT resin having a carboxylic acid end group amount of 3 to 33 meq / kg and an intrinsic viscosity of 0.6 to 1.3 dL / g. The intrinsic viscosity of resin (B) is a value measured with an Ubbelohde viscometer under the condition of a temperature of 35°C in o-chlorophenol.

[0052] In addition, a commercially available product may be used as the resin (B), or a product produced by copolymerizing (polycondensing) a dicarboxylic acid component or its reactive derivative, a diol component or its reactive derivative, and, if necessary, a copolymerizable monomer by a conventional method such as transesterification or direct esterification method may also be used.

[0053] The proportion of the resin (B) in the resin-impregnated fiber bundle (X) is preferably 30 to 95% by mass, more preferably 40 to 90% by mass, and even more preferably 50 to 80% by mass.

[0054] <Method for producing resin-impregnated fiber bundle (X)> As the method for producing the resin-impregnated fiber bundle (X), a conventionally known method using a crosshead die or the like can be adopted. For example, it can be produced according to the methods described in JP-A-2013-107979 (production of resin-impregnated glass long fiber bundle in Production Example 1), JP-A-2013-121988 (production of resin-impregnated glass long fiber bundle in Production Example 1), etc.

[0055] <Other components> The resin composition according to the first embodiment may contain components other than the resin-impregnated fiber bundle (X) (other components). Examples of other components include thermoplastic resins, inorganic fillers other than the glass fiber (a1), antioxidants, weather stabilizers, molecular weight regulators, ultraviolet absorbers, antistatic agents, dyes, pigments, lubricants, crystallization accelerators, crystal nucleating agents, near-infrared absorbers, flame retardants, flame retardant aids, organic fillers, colorants, etc. These other components may be used alone or in combination of two or more. Note that these other components may be blended in the resin-impregnated fiber bundle (X). In one embodiment, the inorganic filler other than the glass fiber (a1) may contain glass short fibers (chopped strands).

[0056] In one embodiment, a thermoplastic resin containing one or more components selected from the polymer and epoxy resin described above for the sizing agent (a2) may be combined with the resin-impregnated fiber bundle (X). Further, the thermoplastic resin may be a polyalkylene terephthalate resin. Furthermore, short glass fibers may be further blended into the polyalkylene terephthalate resin.

[0057] When the resin composition contains other components, it is preferably 10% by mass or less based on the total mass of the resin composition.

[0058] [Method for producing resin composition] The method for producing the resin composition according to the first embodiment is not particularly limited, and any method can be adopted. In one embodiment, the resin-impregnated fiber bundle (X) is obtained by the method for producing the resin-impregnated fiber bundle (X) described above, and the resin-impregnated fiber bundle (X) and other components are mixed as necessary. The resin composition according to the first embodiment may be obtained by a method including this.

[0059] [Molded article] The second embodiment of the present disclosure relates to a molded article. The molded article according to the second embodiment is composed of the resin composition according to the first embodiment. Therefore, the molded article according to the second embodiment is excellent in hydrolysis resistance and also has good mechanical strength.

[0060] The molded article according to the second embodiment has a Charpy impact strength of 40 kJ / cm measured in accordance with ISO179 / 1eA 2 or more, and the retention rate of the tensile strength ((tensile strength after storage (MPa) / tensile strength before storage (MPa)) × 100 (%)) after storage under hydrothermal conditions of 121°C, 100% RH, and 2 atmospheres for 50 hours is preferably 47% or more (here, the tensile strength of the molded article before and after storage is the value measured in accordance with ISO527). Such a molded article is superior in hydrolysis resistance and has good mechanical strength compared to the conventional ones.

[0061] In one embodiment, the flexural strength of the molded article measured in accordance with ISO 178 is preferably 260 MPa or more, more preferably 270 MPa or more.

[0062] [Method for manufacturing a molded article] The method for manufacturing the molded article according to the second embodiment is not particularly limited, and a conventionally known method can be adopted. For example, a molded article may be obtained by a method including injection molding the resin composition according to the first embodiment.

[0063] [Applications] As described above, the molded article according to the second embodiment is excellent in hydrolysis resistance and has good mechanical strength. Such a molded article can be suitably used, for example, in applications that are exposed to high-temperature and high-humidity environments such as automobiles, trains, and aerospace industry applications for a long period of time.

[0064] A non-limiting list of exemplary embodiments of the present disclosure and combinations of exemplary embodiments is described below. [1] A resin composition, The resin composition includes a polyalkylene terephthalate resin-impregnated glass fiber bundle (X) in which a fiber bundle (A) having glass fibers (a1) aligned in the length direction is impregnated with a polyalkylene terephthalate resin (B), The fiber bundle (A) includes a sizing agent (a2) including a polymer including at least one structural unit selected from a structural unit derived from a carboxylic acid and a structural unit derived from a carboxylic anhydride, and an epoxy resin. [2] The resin composition according to [1], wherein the content of the fiber bundle (A) relative to the total mass of the polyalkylene terephthalate resin-impregnated glass fiber bundle (X) is 5 to 70% by mass, and the content of the polyalkylene terephthalate resin (B) is 30 to 95% by mass. [3] The resin composition according to [1] or [2], wherein the average fiber length of the glass fibers (a1) is 5 to 30 mm. [4] The resin composition according to any one of [1] to [3], wherein the polyalkylene terephthalate resin (B) includes a polybutylene terephthalate resin. [5] The resin composition according to any one of [1] to [4], wherein the intrinsic viscosity of the polyalkylene terephthalate resin (B) is 0.6 to 1.3 dL / g and the amount of carboxylic acid end groups is 3 to 33 meq / kg. [6] The resin composition according to any one of [1] to [5], wherein the ratio of the sizing agent (a2) to the total mass of the fiber bundle (A) is 0.1 to 3.0% by mass. [7] A molded article of the resin composition according to any one of [1] to [6].

Examples

[0065] Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following description.

[0066] The components described in Tables 1 to 2 are as follows. Also, the ratio of the sizing agent in the fiber bundle is as shown in Table 1. <Fiber bundle (A)> · Fiber bundle (A-1) (roving): A fiber bundle (count: 2400 tex) obtained by aligning glass fibers (a1) (average fiber diameter: 17 μm) made of E glass in the length direction and bundling them. As the sizing agent (a2), it contains an epoxy resin (phenol novolac type epoxy resin) and a polymer (a copolymer of maleic anhydride, methyl methacrylate, and methyl acrylate). · Fiber bundle (A'-1) (roving): A fiber bundle (count: 2400 tex) obtained by aligning glass fibers (a1) (average fiber diameter: 17 μm) made of E glass in the length direction and bundling them. As the sizing agent, it contains an epoxy resin (phenol novolac type epoxy resin). · Fiber bundle (A'-2) (roving): A fiber bundle (count: 2400 tex) obtained by aligning glass fibers (a1) (average fiber diameter: 17 μm) made of E glass in the length direction and bundling them. As the sizing agent, it contains a polymer (a copolymer of maleic anhydride, methyl methacrylate, and methyl acrylate).

[0067] <Short glass fiber bundle (A'')> · Glass short fiber bundle (A’’-1) (chopped strand): A glass short fiber bundle obtained by bundling and then cutting glass fibers (a1) made of E-glass (average fiber diameter: 13 μm). It contains an epoxy resin (phenol novolac type epoxy resin) and a polymer (a copolymer of maleic anhydride, methyl methacrylate, and methyl acrylate) as a sizing agent. · Glass short fiber bundle (A’’-2) (chopped strand): A glass short fiber bundle obtained by bundling and then cutting glass fibers (a1) made of E-glass (average fiber diameter: 13 μm). It contains an epoxy resin (phenol novolac type epoxy resin) as a sizing agent.

[0068] <Polyalkylene terephthalate resin (B)> · Resin (B-1): PBT resin, manufactured by Polyplastics Co., Ltd., intrinsic viscosity: 0.91 dL / g, carboxylic acid end group content: 7 meq / kg. · Resin (B-2): PBT resin, manufactured by Polyplastics Co., Ltd., intrinsic viscosity: 0.86 dL / g, carboxylic acid end group content: 12 meq / kg. · Resin (B-3): PBT resin, manufactured by Polyplastics Co., Ltd., intrinsic viscosity: 0.66 dL / g, carboxylic acid end group content: 30 meq / kg. <Other components> · Antioxidant: Hindered phenolic antioxidant, manufactured by BASF Japan Ltd., product name "Irganox (registered trademark) 1010".

[0069]

Table 1

[0070] [Example 1] 59.8% by mass of resin (B-1) and 0.2% by mass of an antioxidant were mixed and put into a twin-screw extruder (manufactured by Japan Steel Works, Ltd., product name "TEX30α"). After that, the molten mixture obtained by melt-kneading at a cylinder temperature of 285°C was impregnated into the fiber bundle (A-1) passed through a crosshead die so that the fiber bundle (A-1) accounted for 40% by mass. Then, it was shaped by a shaping nozzle at the crosshead die outlet, shaped by a shaping roll, and then cut into lengths of 9 mm by a pelletizer to obtain the resin composition of Example 1 consisting of pellet-shaped resin-impregnated fiber bundles (X).

[0071] Next, the resin composition (pellets) of Example 1 was injection-molded under the following conditions to obtain a molded product (ISO multipurpose test piece type A1). For the obtained molded product, various mechanical strengths were measured under the following conditions. Also, the moisture and heat resistance was measured under the following conditions. (Molding conditions) Molding machine: manufactured by Fanuc Corporation, product name "ROBOSHOT α-S150iA". Test piece: ISO multipurpose test piece type A1. Molding temperature: 270°C. Mold temperature: 80°C.

[0072] <Evaluation of mechanical strength> ·Measurement of tensile strength and tensile fracture strain Using the obtained ISO multipurpose test piece type A1 (total length 170 mm, parallel part length: 80 mm, thickness: 4 mm), it was measured in accordance with ISO527. Specifically, using a tensile testing machine (manufactured by Shimadzu Corporation, product name "Autograph (registered trademark) AG-20kNXDplus"), it was measured under the conditions of temperature: 23°C, test speed: 5 mm / min, and chuck distance (span) of 115 mm.

[0073] ·Measurement of Charpy impact strength The obtained ISO multi-purpose test piece type A1 was cut into test pieces of 80 mm × 10 mm × 4 mm and measured in accordance with ISO 179 / 1eA. Specifically, using a digital impact tester (manufactured by Yasuda Seiki Seisakusho Co., Ltd., product name "Impact Tester No. 258-L IMPACT TESTER"), the measurement was carried out under the conditions of test temperature: 23°C, measurement mode: with V-notch, and hammer capacity: 4 J.

[0074] ·Measurement of flexural strength and flexural modulus The obtained ISO multi-purpose test piece type A1 was cut into test pieces of 80 mm × 10 mm × 4 mm and measured in accordance with ISO 178. Specifically, using a tensile tester (manufactured by Toyo Seiki Seisakusho Co., Ltd., product name "Bendograph II"), the measurement was carried out under the conditions of temperature: 23°C, test speed: 2 mm / min, and chuck distance (span) 64 mm.

[0075] <Evaluation of Damp Heat Resistance (after 25 hours and 50 hours)> The obtained ISO multi-purpose test pieces were stored for 25 hours or 50 hours under the conditions of 121°C, 100% RH, and 2 atmospheres. Then, the tensile strength was measured under the same conditions as the above measurement of tensile strength. Furthermore, the tensile strength retention rate was calculated from the values of the tensile strength (MPa) after the damp heat test at 25 hours and 50 hours and the tensile strength (MPa) before the test.

[0076] Tensile strength retention rate (%) = (Tensile strength after damp heat test (MPa)) / (Tensile strength before damp heat test (MPa)) × 100

[0077] [Examples 2 to 5 and Comparative Examples 1 to 4] The resin composition was prepared under the same conditions as in Example 1 except that the composition of the resin composition was as shown in Table 2. Molded products were prepared from the obtained resin composition under the same conditions as in Example 1. Also, for the obtained molded products, the evaluation of mechanical strength and damp heat resistance was carried out under the same conditions as in Example 1. The results are shown in Table 2.

[0078] [Comparative Example 5] 59.8% by mass of resin (B-3), 40% by mass of short glass fiber bundles (A''-1), and 0.2% by mass of antioxidant were mixed and put into a 30 mm φ twin-screw extruder (manufactured by Japan Steel Works, Ltd., TEX30C). The temperature of the raw material supply part and the die tip was set at 260 °C, and the temperature between them was set at 220 - 260 °C. The melt kneading was carried out at a discharge rate of 15 kg / h and a screw rotation speed of 130 rpm and then extruded. Thereafter, it was cut into 3 mm lengths by a pelletizer to obtain a pellet-shaped resin composition of Comparative Example 5. Next, the resin composition (pellets) of Comparative Example 5 was injection molded under the same conditions as in Example 1 to obtain a molded product (ISO multi-purpose test piece). For the obtained molded product, various mechanical strengths and moisture and heat resistance were measured under the same conditions as in Example 1. The results are shown in Table 2.

[0079] [Comparative Example 6] A resin composition was prepared under the same conditions as in Comparative Example 5 except that the composition of the resin composition was as shown in Table 2. A molded product was prepared from the obtained resin composition under the same conditions as in Example 1. Also, for the obtained molded product, the mechanical strength and moisture and heat resistance were evaluated under the same conditions as in Example 1. The results are shown in Table 2.

[0080]

Table 2

[0081] As shown in Table 2, the molded products obtained from the resin compositions of Examples 1 to 5 were excellent in moisture and heat resistance and also excellent in mechanical strength. It was found that the molded products of Examples 1 to 5 were particularly excellent in flexural strength and Charpy impact strength. On the other hand, the molded products obtained from the resin compositions of Comparative Examples 1 to 3 in which the sizing agent does not contain a polymer and Comparative Example 4 in which the sizing agent does not contain an epoxy resin were slightly inferior in moisture and heat resistance to the molded products of the Examples. Also, the tensile strength, flexural strength, and Charpy impact strength were significantly lower than those of the molded products of the Examples. The resin compositions of Comparative Examples 5 to 6 containing short glass fiber bundles had good moisture and heat resistance, but their mechanical strength was significantly lower than that of the molded products of the Examples. From the above results, it was confirmed that the resin composition according to the first embodiment is excellent in hydrolysis resistance and can obtain a molded product with good mechanical strength.

Claims

1. A resin composition, wherein the resin composition contains a polyalkylene terephthalate resin-impregnated glass fiber bundle (X) in which a fiber bundle (A) with glass fibers (a1) aligned in the length direction is impregnated with a polyalkylene terephthalate resin (B), and the fiber bundle (A) contains a sizing agent (a2) including a polymer containing at least one structural unit selected from a structural unit derived from a carboxylic acid and a structural unit derived from a carboxylic anhydride, and an epoxy resin. The resin composition.

2. The resin composition according to Claim 1, wherein the content of the fiber bundle (A) is 5 to 70% by mass and the content of the polyalkylene terephthalate resin (B) is 30 to 95% by mass with respect to the total mass of the polyalkylene terephthalate resin-impregnated glass fiber bundle (X).

3. The resin composition according to Claim 1 or 2, wherein the average fiber length of the glass fibers (a1) is 5 to 30 mm.

4. The resin composition according to Claim 1 or 2, wherein the polyalkylene terephthalate resin (B) contains a polybutylene terephthalate resin.

5. The resin composition according to Claim 1 or 2, wherein the inherent viscosity of the polyalkylene terephthalate resin (B) is 0.6 to 1.3 dL / g and the amount of carboxylic acid end groups is 3 to 33 meq / kg.

6. The resin composition according to Claim 1 or 2, wherein the ratio of the sizing agent (a2) with respect to the total mass of the fiber bundle (A) is 0.1 to 3.0% by mass.

7. A molded article of the resin composition according to Claim 1 or 2.

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