Resin composition and molded article of the same

Abstract

To provide a resin composition from which a molded article having excellent hydrolysis resistance and more excellent mechanical strength than conventional one 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 (A1) where glass fibers (A) are aligned in a length direction is impregnated with a mixture (D) containing a polyalkylene terephthalate resin (B) and an epoxy compound (C) having an epoxy equivalent of 600 to 1,500 g / eq, wherein a content of the epoxy compound (C) to the total mass of the polyalkylene terephthalate resin-impregnated glass fiber bundle (X) is less than 2.9 mass%.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 mechanical properties and heat resistance particularly when combined with an inorganic filler such as glass fiber, and 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 devices. On the other hand, since polyester resins have ester groups in the molecule, hydrolysis easily occurs in a high-temperature and high-humidity environment, and 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 polyester resins themselves, it is known to blend an epoxy compound or a carbodiimide compound. For example, Patent Document 1 shows that the hydrolysis resistance can be improved by blending an epoxy compound with polybutylene terephthalate having a specific terminal carboxyl group concentration and intrinsic viscosity. In addition, the hydrolysis resistance of glass fiber-containing polyester resin compositions has also been improved by treating the surface of glass fiber blended as an inorganic filler. For example, Patent Document 2 proposes a polyester resin composition containing glass fiber 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 molded articles obtained from conventional glass fiber-containing polyester resin compositions still have insufficient hydrolysis resistance, and improvement in mechanical strength is also desired.

[0006] The present application has been made in view of the above circumstances, and an object thereof is to provide a resin composition and a molded article thereof that are excellent in hydrolysis resistance and have higher mechanical strength than conventional ones.

Means for Solving the Problems

[0007] As a result of intensive studies, the inventors of the present application have found that a resin composition, which contains a glass fiber impregnated polyalkylene terephthalate resin bundle (X) impregnated with a mixture (D) containing a polyalkylene terephthalate resin (B) and an epoxy compound (C) having an epoxy equivalent of 600 to 1500 g / eq in a fiber bundle (A1) in which glass fibers (A) are aligned in the longitudinal direction, and the content of the epoxy compound (C) is less than 2.9% by mass based on the total mass of the polyalkylene terephthalate resin impregnated glass fiber bundle (X), can solve the above-mentioned problems.

Effects of the Invention

[0008] According to the present invention, it is possible to provide a resin composition and a molded article thereof that are excellent in hydrolysis resistance and have higher mechanical strength than conventional ones.

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 features 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 explanation described for one embodiment also applies to other embodiments, the explanation 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 features 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 glass fiber (A) aligned in the length direction in a fiber bundle (A1), a polyalkylene terephthalate resin (B), and a mixture (D) containing an epoxy compound (C) having an epoxy equivalent of 600 to 1500 g / eq, and the resin composition contains a polyalkylene terephthalate resin-impregnated glass fiber bundle (X) impregnated with the mixture (D), and relates to a resin composition in which the content of the epoxy compound (C) is less than 2.9% by mass based on the total mass of the polyalkylene terephthalate resin-impregnated glass fiber bundle (X). The resin composition according to the first embodiment includes a resin-impregnated fiber bundle obtained by impregnating a glass fiber bundle with a resin. In this way, by impregnating the fiber bundle (A1) with a mixture (D) containing a polyalkylene terephthalate resin (B) and a specific epoxy compound (C), a molded article excellent in hydrolysis resistance and having better mechanical strength than conventional ones can be obtained.

[0012] <Polyalkylene terephthalate resin-impregnated glass fiber bundle (X)> The resin composition according to the first embodiment includes a polyalkylene terephthalate resin-impregnated glass fiber bundle (X) (hereinafter referred to as "resin-impregnated fiber bundle (X)"). The resin-impregnated fiber bundle (X) is a composite material obtained by impregnating a fiber bundle (A1) in which glass fibers (A) are aligned in the longitudinal direction with a mixture (D) containing a polyalkylene terephthalate resin (B) (hereinafter sometimes referred to as "resin (B)") and an epoxy compound (C) having an epoxy equivalent of 600 to 1500 g / eq, and then cutting. In one embodiment, the resin composition may contain only the resin-impregnated fiber bundle (X).

[0013] (Fiber bundle (A1)) The fiber bundle (A1) is formed by bundling glass fibers (A) in the longitudinal direction. In this way, by impregnating the fiber bundle (A1) in which glass fibers (A) are bundled in the longitudinal direction with the mixture (D), a molded article having improved mechanical strength compared to a molded article obtained from a conventional glass fiber-containing polyester resin composition can be obtained. Also, a molded article excellent in hydrolysis resistance can be obtained.

[0014] (Glass fiber (A)) The type of the glass fiber (A) is not particularly limited, but in terms of quality, E-glass fibers or fibers of corrosion-resistant glass containing zirconium elements in the composition are preferably used.

[0015] ·Average fiber diameter In one embodiment, the average fiber diameter of the glass fiber (A) is preferably 5 to 20 μm, more preferably 8 to 20 μm, and even 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 (A) is the average value of the fiber diameters measured for about 100 of the fibers observed with a scanning electron microscope after heating the resin composition (or resin-impregnated fiber bundle (X)) at 600°C for 2 hours to obtain an ash residue and observing the glass fiber (A) of this ash residue.

[0016] ·Average fiber length In one embodiment, the average fiber length of the glass fiber (A) in the fiber bundle (A1) 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 (A1) of the glass fiber (A) with an average fiber length of 5 to 30 mm with the mixture (D), a molded product having more excellent mechanical strength is likely to be obtained. The average fiber length of the glass fiber (A) can be calculated from the average value of the major axis lengths of about 100 pellets of the resin-impregnated fiber bundle (X) measured with calipers or the like. Also, when the resin composition contains a resin-impregnated fiber bundle (X) and other thermoplastic resins, the average fiber length of the glass fiber (A) in the resin composition is preferably also within the above range. The average fiber length of the glass fiber (A) 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 fiber (A) of this ash residue in a medium, and performing image processing on the fibers.

[0017] In one embodiment, as the glass fiber (A), either one having a circular cross-section or one having a non-circular cross-section can be used. Examples of the non-circular cross-section include an oval shape, an elliptical shape, a cocoon shape, etc. The aspect 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 aspect 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 product are easily obtained. Also, it is easy to suppress the glass fiber (A) from becoming too flat and being easily broken, and as a result, the strength of the molded product from decreasing.

[0018] The glass fiber (A) may be used alone or in combination of two or more. When combining two or more glass fibers (A), glass fibers (A) with different fiber cross-sections may be combined, or glass fibers (A) with different average fiber diameters may be combined.

[0019] In one embodiment, the number of glass fibers (A) in the fiber bundle (A1) can be adjusted in consideration of the outer diameter (major axis length and minor axis length) of the fiber bundle (A1). For example, the number of glass fibers (A) may be 100 to 30,000, may be 500 to 20,000, or may be 1,000 to 10,000. Among these, from the viewpoint of manufacturability, the number of glass fibers (A) is preferably 2,000 to 6,000.

[0020] In one embodiment, the content of the glass fiber (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, even more preferably 20 to 55% by mass, and particularly preferably 30 to 50% by mass.

[0021] In one embodiment, the glass fiber (A) may be bundled by a bundling agent. That is, the fiber bundle (A1) may contain the glass fiber (A) and the bundling agent.

[0022] (Mixture (D)) The mixture (D) contains a resin (B) and an epoxy compound (C) having an epoxy equivalent of 600 to 1500 g / eq. As described above, by impregnating the fiber bundle (A1) with the mixture (D) in which the specific epoxy compound (C) is combined with the resin (B), the molded article obtained from the resin composition according to the first embodiment is excellent in hydrolysis resistance and mechanical strength. In the present disclosure, the mixture (D) is an impregnating component of the resin-impregnated fiber bundle (X).

[0023] (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 or a diol component other than the main components. Further, a copolyester combined with an oxycarboxylic acid component, a lactone component, etc. (hereinafter sometimes referred to as a copolymerizable monomer) can also be used as another copolymerizable monomer.

[0024] 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, hymic 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 two or more of these can also be used in combination. However, with respect to the total amount of the dicarboxylic acid components contained as copolymerizable monomers, it is preferable to contain 50 mol% or more of the aromatic dicarboxylic acid compound, more preferably 80 mol% or more, and particularly preferably 90 mol% or more. Further, if necessary, polyvalent carboxylic acids such as trimellitic acid, pyromellitic acid or ester-forming derivatives thereof (such as alcohol esters) etc. may be used in combination. By using such polyfunctional compounds in combination, a branched resin (B) can also be obtained.

[0025] 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 components 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.

[0026] 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 derivatives thereof.

[0027] Examples of the lactone include lactones having 3 to 12 carbon atoms such as propiolactone, butyrolactone, valerolactone, caprolactone (e.g., ε-caprolactone, etc.).

[0028] 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% based on 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).

[0029] 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, and polybutylene terephthalate (PBT) resin; copolyesters containing an alkylene isophthalate unit as a copolymer component with an alkylene terephthalate unit as a main component; copolyesters containing an alkylene naphthalate unit as a copolymer 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 (B) as a thermoplastic resin. Further, in a preferred embodiment, the resin composition contains only a PBT resin as a thermoplastic resin.

[0030] ·Amount of carboxylic acid end groups The amount of carboxylic acid end groups of the 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 of the 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 of the resin (B) is in the range of 3 to 33 meq / kg, the adhesion between the glass fiber (A) and the resin (B) is likely to be good. Also, the hydrolysis resistance of the resulting molded product is likely to be good. In a preferred embodiment, the 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 of the resin (B) can be measured by titrating a pulverized sample of the pellets of the 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.

[0031] ·Intrinsic viscosity The intrinsic viscosity of the 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 the resin (B) is preferably 0.6 to 1.3 dL / g, more preferably 0.7 to 1.2 dL / g, from the viewpoint of moldability. 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, the 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 the resin (B) is a value measured by an Ubbelohde viscometer under the condition of a temperature of 35°C in o-chlorophenol.

[0032] In addition, commercially available products may be used as the resin (B), or those 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.

[0033] In one embodiment, the proportion of the resin (B) in the mixture (D) is preferably 90 to 99% by mass based on the total mass of the mixture (D). The proportion of the resin (B) may be 92 to 99% by mass, may be 93.5 to 99% by mass, or may be 94 to 99% by mass. Also, in one embodiment, the proportion of the resin (B) in the resin-impregnated fiber bundle (X) is preferably 25 to 90% by mass, more preferably 40 to 90% by mass, and even more preferably 50 to 80% by mass. When the proportion of the resin (B) is within the above range, a resin composition excellent in mechanical strength and moldability can be easily obtained.

[0034] (Epoxy compound (C)) The resin-impregnated fiber bundle (X) contains an epoxy compound (C) having an epoxy equivalent of 600 to 1500 g / eq. When the epoxy equivalent of the epoxy compound (C) is 600 g / eq or more, molded products excellent in hydrolysis resistance and mechanical strength can be obtained. Furthermore, thickening occurs due to the reaction between the resin (B) and the epoxy compound (C), which can prevent production defects such as the mixture (D) being difficult to impregnate the fiber bundle (A1) or the glass fiber (A) breaking during resin impregnation. Also, when the epoxy equivalent is 1500 g / eq or less, hydrolysis resistance can be imparted without impairing the mechanical properties due to the foreign matter effect.

[0035] The epoxy equivalent of the epoxy compound (C) can be arbitrarily adjusted within the range of 600 to 1500 g / eq. In one embodiment, the epoxy equivalent of the epoxy compound (C) may be 700 to 1300 g / eq, or may be 800 to 1000 g / eq.

[0036] As the epoxy compound (C), any epoxy resin with an epoxy equivalent of 600 to 1500 g / eq can be used. In one embodiment, from the viewpoint that the hydrolysis resistance and mechanical strength of the obtained molded product are likely to be improved, it is preferable to use an aromatic epoxy compound with an epoxy equivalent of 600 to 1500 g / eq. Examples of such aromatic epoxy compounds include biphenyl-type epoxy compounds, bisphenol A-type epoxy compounds, phenol novolak-type epoxy compounds, cresol novolak-type epoxy compounds, and the like. These may be used alone or in combination of two or more.

[0037] More preferable examples of the aforementioned aromatic epoxy compounds include at least one selected from bisphenol A-type epoxy resins and novolak-type epoxy resins having a weight average molecular weight of 1,000 to 2,000. The weight average molecular weight can be measured by GPC.

[0038] The content of the epoxy compound (C) in the resin-impregnated fiber bundle (X) is less than 2.9% by mass based on the total mass of the resin-impregnated fiber bundle (X). When the content of the epoxy compound (C) in the resin-impregnated fiber bundle (X) is 2.9% by mass or more, the mechanical strength of the obtained molded product is likely to decrease. In addition, black foreign matter may occur and the appearance of the molded product may deteriorate. Here, the "black foreign matter" means a blackish foreign matter having a maximum length or maximum major axis of 1 mm or more present on the surface of the molded product. According to the study of the inventors of the present application, it has been found that black foreign matter may occur on the surface of a molded product obtained from a resin composition containing the resin-impregnated fiber bundle (X). As a result of further study by the inventors of the present application, it has been found that black foreign matter is likely to occur as the proportion of the epoxy compound (C) in the resin-impregnated fiber bundle (X) increases. That is, according to the resin composition according to the first embodiment, since the content of the epoxy compound (C) in the resin-impregnated fiber bundle (X) is controlled to be less than 2.9% by mass, not only is it excellent in hydrolysis resistance and mechanical strength, but also the generation of black foreign matter can be effectively suppressed.

[0039] In one embodiment, the content of the epoxy compound (C) in the resin-impregnated fiber bundle (X) is preferably 0.1% by mass or more and less than 2.9% by mass, more preferably 0.3 to 2.5% by mass, and particularly preferably 0.5 to 2.0% by mass.

[0040] The proportion of the epoxy compound (C) in the mixture (D) is preferably 0.3 to 11% by mass. The proportion of the epoxy compound (C) may be 0.3 to 10% by mass, may be 0.5 to 10% by mass, may be 0.5% by mass or more and less than 5.0% by mass, may be 0.7% by mass or more and less than 5.0% by mass, or may be 0.7 to 3.5% by mass.

[0041] The mixture (D) may contain components other than the resin (B) and the epoxy compound (C) (other components). Examples of the other components include thermoplastic resins other than the resin (B), 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, and the like. These other components may be used alone or in combination of two or more. Among these, from the viewpoint of heat aging resistance, it is preferable to contain an antioxidant.

[0042] As the antioxidant, a phenolic antioxidant is preferable, and a hindered phenolic antioxidant is more preferable. Examples of the hindered phenol-based antioxidant include pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, thiodiethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide), 2,4-dimethyl-6-(1-methylpentadecyl)phenol, diethyl [[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphoate, 3,3',3",5,5',5"-hexa-tert-butyl-a,a',a"-(mesitylene-2,4,6-triyl)tri-p-cresol, 4,6-bis(octylthiomethyl)-o-cresol, ethylene bis(oxyethylene) bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], hexamethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazin-2-ylamino)phenol, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate, and the like. These antioxidants may be used alone or in combination of two or more. By blending such an antioxidant into the mixture (D), heat aging resistance can be easily obtained. In one embodiment, the proportion of the antioxidant in the mixture (D) is preferably 0.1 to 1.0 parts by mass, more preferably 0.1 to 0.8 parts by mass, and even more preferably 0.2 to 0.7 parts by mass with respect to 100 parts by mass of the resin (B).

[0043] In one embodiment, the mixture (D) preferably contains only the resin (B) and the epoxy compound (C) as resin components. In a more preferred embodiment, the mixture (D) contains only the resin (B) and the epoxy compound (C) as resin components and contains an antioxidant as other components. In the mixture (D), the proportion of the antioxidant is preferably 0.1 to 0.7 parts by mass, and particularly preferably 0.2 to 0.6 parts by mass, based on 100 parts by mass in total of the resin (B) and the epoxy compound (C). By impregnating such a mixture (D) into the fiber bundle (A1), the hydrolysis resistance, mechanical strength, and appearance of the resulting molded article are more likely to be improved.

[0044] <Method for producing resin-impregnated fiber bundle (X)> As a 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), and the like.

[0045] <Other components> The resin composition according to the first embodiment can contain components other than the resin-impregnated fiber bundle (X) (other components). Examples of other components include the same components as those that may be contained in the above-described mixture (D). These other components may be used alone or in combination of two or more. Note that, as described above, these other components may be blended in the mixture (D). When the resin composition contains other components, it is preferably 5% by mass or less based on the total mass of the resin composition.

[0046] [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 composition according to the first embodiment may be obtained by a method including obtaining the resin-impregnated fiber bundle (X) by the method for producing the resin-impregnated fiber bundle (X) described above, and mixing the resin-impregnated fiber bundle (X) and other components as necessary.

[0047] [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 has good mechanical strength. In addition, since black foreign matter is less likely to occur, the appearance of the molded article is also good.

[0048] The molded article according to the second embodiment has a Charpy impact strength of 40 kJ / cm 2 or more as measured in accordance with ISO179 / 1eA, and it is preferable that 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 atm for 50 hours is 50% 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.

[0049] In one embodiment, the flexural strength of the molded article measured in accordance with ISO178 is preferably 270 MPa or more, more preferably 280 MPa or more.

[0050] [Method for producing molded article] The method for producing 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.

[0051] [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 for a long time, such as in the automotive, railway, and aviation industries.

[0052] A non-limiting list of exemplary embodiments and combinations of exemplary embodiments of the present disclosure is described below. [1] A resin composition, The resin composition contains a glass fiber (A) impregnated with a mixture (D) containing a polyalkylene terephthalate resin (B) and an epoxy compound (C) having an epoxy equivalent of 600 to 1500 g / eq in a fiber bundle (A1) with the glass fibers (A) aligned in the length direction, A resin composition in which the content of the epoxy compound (C) is less than 2.9% by mass based on the total mass of the polyalkylene terephthalate resin-impregnated glass fiber bundle (X). [2] Based on the total mass of the polyalkylene terephthalate resin-impregnated glass fiber bundle (X), the content of the glass fiber (A) is 5 to 70% by mass, the content of the polyalkylene terephthalate resin (B) is 25 to 90% by mass, the resin composition according to [1]. [3] The resin composition according to [1] or [2], wherein the average fiber length of the glass fiber (A) is 5 to 30 mm. [4] The resin composition according to any one of [1] to [3], wherein the polyalkylene terephthalate resin (B) contains 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] A molded article of the resin composition according to any one of [1] to [5].

Examples

[0053] Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following description.

[0054] The components described in Tables 1 to 3 are as follows. <Fiber bundle (A1)> · Fiber bundle (A1): A fiber bundle obtained by bundling E-glass fibers (A) made of E-glass in the length direction (rovings manufactured by Nippon Electric Glass Co., Ltd., product name "T-439N", average fiber diameter: 17 μm, count: 2400 tex). · Glass short fiber bundle (A1'): A glass short fiber bundle obtained by bundling glass fibers (A) made of E-glass (chopped strands manufactured by Nippon Electric Glass Co., Ltd., product name "T-187", average fiber diameter: 13 μm) and then cutting.

[0055] <Mixture (D)> (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. (Epoxy compound (C)) · Epoxy compound (C): Bisphenol A type epoxy compound (manufactured by Mitsubishi Chemical Corporation, product name "jER (registered trademark) 1004", epoxy equivalent: 925 g / eq, weight average molecular weight: 1600). · Epoxy compound (C'): Bisphenol A type epoxy compound (manufactured by Mitsubishi Chemical Corporation, product name "jER1001", epoxy equivalent: 525 g / eq, weight average molecular weight: 900). · Antioxidant: Hindered phenol-based antioxidant, manufactured by BASF Japan Ltd., product name "Irganox (registered trademark) 1010".

[0056] [Example 1] 59.3% by mass of resin (B-1), 0.5% by mass of epoxy compound (C), and 0.2% by mass of antioxidant were mixed and fed 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 a fiber bundle (A1) passed through a crosshead die so that the fiber bundle (A1) accounted for 40% by mass. Then, it was shaped by a shaping nozzle at the crosshead die outlet, and after shaping with a shaping roll, it was cut into pieces 9 mm in length by a pelletizer to obtain the resin composition of Example 1 consisting of pellet-shaped resin-impregnated fiber bundles (X). 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 and moisture and heat resistance were measured under the following conditions. Also, the presence or absence of black foreign matters was evaluated 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.

[0057] <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), measurements were made in accordance with ISO527. Specifically, using a tensile testing machine (manufactured by Shimadzu Corporation, product name "Autograph (registered trademark) AG-20kNXDplus"), measurements were made under the conditions of temperature: 23°C, test speed: 5 mm / min, and chuck distance (span) 115 mm.

[0058] ·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 ISO179 / 1eA. Specifically, it was measured using a digital impact tester (manufactured by Yasuda Seiki Seisakusho Co., Ltd., product name "Impact Tester No. 258-L IMPACT TESTER") under the conditions of test temperature: 23°C, measurement mode: with V-notch, and hammer capacity: 4 J.

[0059] ·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 ISO178. Specifically, it was measured using a tensile tester (manufactured by Toyo Seiki Seisakusho Co., Ltd., product name "Bendograph II") under the conditions of temperature: 23°C, test speed: 2 mm / min, and chuck distance (span) 64 mm.

[0060] <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 atm. 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 respectively and the tensile strength (MPa) before the test.

[0061] Tensile strength retention rate (%) = (Tensile strength after damp heat test (MPa)) / (Tensile strength before damp heat test (MPa)) × 100

[0062] <Evaluation of Black Foreign Matter> The presence or absence of black foreign matter on the surface of the obtained ISO multi-purpose test piece type A1 was evaluated. Foreign matters with a maximum length or maximum major axis of 1 mm or more were targeted.

[0063] [Examples 2 to 11 and Comparative Examples 1 to 3, 6 to 11] A resin composition composed of a resin-impregnated fiber bundle was prepared under the same conditions as in Example 1, except that the composition of the resin composition was as shown in Tables 1 to 3. A molded product was prepared from the obtained resin composition under the same conditions as in Example 1. Further, for the obtained molded product, various mechanical strengths, heat and humidity resistance, and black foreign matter were evaluated under the same conditions as in Example 1. The results are shown in Tables 1 to 3.

[0064] [Comparative Example 4] 59.8% by mass of resin (B-3), 40% by mass of short glass fiber bundle (A1'), and 0.2% by mass of antioxidant were mixed and put into a 30 mm φ twin-screw extruder (TEX30C, manufactured by Japan Steel Works, Ltd.). 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. Then, it was cut into lengths of 3 mm by a pelletizer to obtain a pellet-shaped resin composition of Comparative Example 4. Next, the resin composition (pellets) of Comparative Example 4 was injection molded under the same conditions as in Example 1 to obtain a molded product (ISO multi-purpose test piece type 1A). For the obtained molded product, various mechanical strengths, heat and humidity resistance, and black foreign matter were evaluated under the same conditions as in Example 1. The results are shown in Table 1.

[0065] [Comparative Example 5] A resin composition was prepared under the same conditions as in Comparative Example 4, except that the composition of the resin composition was as shown in Table 1. A molded product was prepared from the obtained resin composition under the same conditions as in Example 1. Further, for the obtained molded product, various mechanical strengths, heat and humidity resistance, and black foreign matter were evaluated under the same conditions as in Example 1. The results are shown in Table 1.

[0066] [Table 1]

[0067] Table 1 shows the results of Examples 1 - 3 and Comparative Examples 1 - 5. Examples 1 - 3 and Comparative Examples 1 - 3 are the evaluation results of molded products of resin compositions composed of resin-impregnated fiber bundles. Further, Comparative Examples 4 - 5 are the evaluation results of molded products of resin compositions containing short glass fiber bundles (chopped strands). As shown in Table 1, the molded products of Examples 1 to 3 obtained from the resin composition composed of the resin-impregnated fiber bundle (X) were superior in moisture and heat resistance and mechanical strength to the molded products of Comparative Examples 1 to 3. Furthermore, the mechanical strength of the molded products of these Examples 1 to 3 was significantly improved compared to the mechanical strength of the molded products obtained from the resin compositions of Comparative Examples 4 to 5 containing short glass fiber bundles. By using the resin-impregnated fiber bundle (X), it was found that the tensile strength, flexural strength, and Charpy impact strength were particularly improved. Also, there were no black foreign matters in the molded products of these Examples 1 to 3.

[0068]

Table 2

[0069] Table 2 shows the results of Examples 4 to 9 and Comparative Examples 6 to 8. These Examples and Comparative Examples are examples in which the ratio of the epoxy compound (C) in the resin-impregnated fiber bundle (X) was changed. As shown in Table 2, it was found that in the molded products of Comparative Examples 6 to 8 in which the content of the epoxy compound (C) in the resin-impregnated fiber bundle (X) was 3.0% by mass, the mechanical strength tended to be lower than that of the molded products of Examples 4 to 9. Furthermore, black foreign matters were present on the surface of the molded products, and it was found that the appearance was inferior.

[0070]

Table 3

[0071] Table 3 shows the results of Examples 10 to 11 and Comparative Examples 9 to 11. Examples 10 to 11 and Comparative Examples 9 to 10 examined the influence of the presence or absence of the epoxy compound (C) when the ratio of the fiber bundle (A1) in the resin-impregnated fiber bundle (X) was changed. As shown in Table 3, it was found that even when the ratio of the fiber bundle (A1) was changed to 30% by mass and 50% by mass, the hydrolysis resistance and mechanical strength of the molded articles in Examples 10 to 11 were superior to those in Comparative Examples 10 to 11. Further, in Comparative Example 11 containing an epoxy compound (C') having an epoxy equivalent of less than 600 g / eq, the resin thickened during production and fiber breakage occurred, and the resin-impregnated fiber bundle (X) could not be produced. From the above results, it was confirmed that the resin composition according to the first embodiment is excellent in hydrolysis resistance and can provide a molded article having superior mechanical strength than conventional ones. Further, the resin composition according to the first embodiment is also excellent in stability during production. In addition, the molded article obtained from the resin composition according to the first embodiment has no black foreign matter and has a good appearance.

Claims

1. A resin composition, wherein the resin composition contains a polyalkylene terephthalate resin-impregnated glass fiber bundle (X) impregnated with a mixture (D) containing a polyalkylene terephthalate resin (B) and an epoxy compound (C) having an epoxy equivalent of 600 to 1500 g / eq in a fiber bundle (A1) in which glass fibers (A) are aligned in the longitudinal direction, and the content of the epoxy compound (C) is less than 2.9% by mass based on the total mass of the polyalkylene terephthalate resin-impregnated glass fiber bundle (X).

2. Based on the total mass of the polyalkylene terephthalate resin-impregnated glass fiber bundle (X), the content of the glass fiber (A) is 5 to 70% by mass, and the content of the polyalkylene terephthalate resin (B) is 25 to 90% by mass. The resin composition according to Claim 1.

3. The resin composition according to Claim 1 or 2, wherein the average fiber length of the glass fiber (A) 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 polyalkylene terephthalate resin (B) has an intrinsic viscosity of 0.6 to 1.3 dL / g and a carboxylic acid end group amount of 3 to 33 meq / kg.

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

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