Resin composition and molded article

Abstract

The invention provides a resin composition and a molded article. A resin composition containing 2-15 parts by mass of an elastomer, 3-20 parts by mass of a hydroxyl group-containing compound, and 3-20 parts by mass of conductive carbon per 100 parts by mass of a resin component comprising a polybutylene terephthalate resin, the hydroxyl group concentration represented by [(hydroxyl group-derived peak area / total peak area) * 100], which is the ratio of the hydroxyl group-derived peak area to the total peak area when the hydroxyl group-containing compound is analyzed by 1H NMR, is within the range of 0.5-15.0%.

Description

Technical Field

[0001] The present invention relates to a resin composition and a molded article, and more particularly to a conductive resin composition suitable for electrostatic coating of a water-based paint. Background Art

[0002] Polybutylene terephthalate resin is easy to process and has excellent mechanical properties, electrical properties, heat resistance and other physical / chemical properties. Therefore, it is widely used in automobile parts, electrical / electronic equipment parts and other precision equipment parts.

[0003] At present, the fuel cap parts of automobiles are mainly made of steel plates, but in recent years, resin fuel cap parts have attracted attention due to their high degree of shape freedom. In addition, in order to reduce process costs, in-line electrostatic coating is specially carried out in the coating of this part.

[0004] As an electrostatic coating material, a resin composition having conductivity has been proposed. For example, Patent Document 1 discloses a conductive polyester resin composition comprising conductive carbon black, an ethylene copolymer-based impact modifier, and a hyperbranched polyester.

[0005] In addition, in recent years, in order to cope with the molding of parts with complex shapes, the demand for molding processability has increased. In order to improve the molding processability, the resin material is required to have improved fluidity when melted. For example, Patent Document 2 discloses a polybutylene terephthalate resin composition containing a thermoplastic elastomer and an acrylic oligomer.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: International Publication No. 2019 / 037122

[0009] Patent Document 2: International Publication No. 2008 / 075776 Summary of the invention

[0010] Problems to be solved by the invention

[0011] Here, from the viewpoint of imparting designability, rust resistance, and weather resistance to a molded body formed of a composition containing a polybutylene terephthalate resin and conductive carbon, painting may be performed.

[0012] However, the inventors of the present invention have conducted research and found that when a molded body formed from a composition containing a polybutylene terephthalate resin and conductive carbon is coated with a water-based paint, there is a problem that the adhesion between the molded body and the water-based paint is low, and the water-based paint is easily peeled off.

[0013] The purpose of the present invention is to solve the above-mentioned problems, and its purpose is to provide a resin composition and a molded body, wherein the resin composition is a resin composition containing polybutylene terephthalate resin and conductive carbon, which can provide a molded body that has high adhesion with water-based paint when applying water-based paint and the water-based paint is not easy to peel off.

[0014] Methods for solving problems

[0015] Based on the above problems, the present inventors have conducted intensive studies and found that the above problems can be solved by blending an elastomer, a hydroxyl group-containing compound and conductive carbon in a resin component including a polybutylene terephthalate resin at a predetermined ratio.

[0016] Specifically, the above-mentioned problems were solved by the following means.

[0017] <1> A resin composition, wherein, relative to 100 parts by mass of a resin component comprising a polybutylene terephthalate resin, 2 to 15 parts by mass of an elastomer, 3 to 20 parts by mass of a hydroxyl-containing compound and 3 to 20 parts by mass of conductive carbon are contained, wherein the hydroxyl-containing compound is 1 The hydroxyl concentration represented by the ratio of the peak area derived from hydroxyl groups to the total peak area in H NMR analysis, i.e., [peak area derived from hydroxyl groups / total peak area)×100, is in the range of 0.5 to 15.0%.

[0018] <2> according to <1> The resin composition, wherein the resin component further comprises a polycarbonate resin.

[0019] <3> according to <2> The resin composition further comprises 0.05 to 2 parts by mass of a phosphorus stabilizer based on 100 parts by mass of the resin component.

[0020] <4> according to <1> ~ <3> The resin composition described above, wherein the polybutylene terephthalate resin has an intrinsic viscosity of 1.00 to 1.50 dL / g.

[0021] <5> according to <1> ~ <4> The resin composition described above, wherein the elastomer contains an epoxy-containing compound.

[0022] <6> according to <1> ~ <5> The resin composition described above, wherein the hydroxyl-containing compound has a weight average molecular weight of 1,500 to 30,000.

[0023] <7> according to <1> ~ <6> The resin composition described in any one of the preceding claims, wherein the hydroxyl group-containing compound comprises a (meth)acrylic acid compound.

[0024] <8> according to <1> ~ <7> The resin composition described in any one of the preceding claims, wherein the hydroxyl group-containing compound is an amorphous compound.

[0025] <9> according to <1> ~ <8> The resin composition described above, wherein the hydroxyl group concentration of the hydroxyl group-containing compound is within a range of 0.5 to 10.0%.

[0026] <10> according to <1> ~ <9> The resin composition described in any one of the above is used for forming a molded body for electrostatic coating of a water-based paint.

[0027] <11> A molded body comprising <1> ~ <10> The resin composition described in any one of the above is formed.

[0028] <12> according to <11> The molded body is a fuel oil port cover.

[0029] Effects of the Invention

[0030] According to the present invention, a resin composition and a molded body can be provided. The resin composition is a resin composition containing a polybutylene terephthalate resin and conductive carbon, and can provide a molded body that has high adhesion to the water-based paint when the water-based paint is applied and the water-based paint is not easily peeled off. DETAILED DESCRIPTION

[0031] Hereinafter, a mode for implementing the present invention (hereinafter, simply referred to as "this embodiment") will be described in detail. It should be noted that the following this embodiment is an example for explaining the present invention, and the present invention is not limited to this embodiment.

[0032] In addition, in this specification, "to" is used to mean that the numerical values ​​described before and after it are included as a lower limit and an upper limit.

[0033] In this specification, various physical property values ​​and characteristic values ​​are assumed to be values ​​at 23° C. unless otherwise specified.

[0034] In the description of the group (atomic group) in this specification, the description of not recording substitution and unsubstituted includes the group (atomic group) with substitution while including the group (atomic group) without substitution. For example, "alkyl" includes not only the alkyl group without substitution (unsubstituted alkyl group), but also the alkyl group with substitution (substituted alkyl group). In this specification, the description of not recording substitution and unsubstituted is preferably unsubstituted.

[0035] In the present specification, "(meth)acrylate" means both or either of acrylate and methacrylate, and "(meth)acrylic acid" means both or either of acrylic acid and methacrylic acid.

[0036] In this specification, the weight average molecular weight is a polystyrene conversion value measured by GPC (gel permeation chromatography) method.

[0037] In the present specification, the term "step" includes not only an independent step but also a step that cannot be clearly distinguished from other steps as long as the intended effect of the step is achieved.

[0038] In this specification, ppm means mass ppm.

[0039] When the standards shown in this manual differ in measurement methods depending on the year, unless otherwise specified, they are based on the standards as of January 1, 2021.

[0040] The resin composition of the present embodiment is characterized in that it contains 2 to 15 parts by mass of an elastomer, 3 to 20 parts by mass of a hydroxyl-containing compound, and 3 to 20 parts by mass of conductive carbon, relative to 100 parts by mass of a resin component containing a polybutylene terephthalate resin, wherein the hydroxyl-containing compound is 1 The hydroxyl concentration represented by the ratio of the peak area derived from the hydroxyl group to the total peak area when analyzed by H NMR, i.e., [peak area derived from the hydroxyl group / total peak area)×100, is in the range of 0.5 to 15.0%. By setting the above configuration, a resin composition can be obtained, which is a resin composition comprising a polybutylene terephthalate resin and conductive carbon, and can provide a molded body that has high adhesion to the water-based paint when applied with the water-based paint and is not easy to peel off the water-based paint.

[0041] The reason for this is presumably that the polybutylene terephthalate resin and the hydroxyl-containing compound are moderately compatible, so that the hydroxyl-containing compound does not separate from the polybutylene terephthalate resin but precipitates on the surface of the obtained molded body, and the hydroxyl groups of the hydroxyl-containing compound react with the water-based coating material, thereby significantly improving the coating adhesion.

[0042] <<Polybutylene terephthalate resin>>

[0043] Polybutylene terephthalate resin can be produced on a large scale by reacting terephthalic acid with 1,4-butanediol. In the present embodiment, these resins available on the market can be used. Polybutylene terephthalate resin sometimes also contains copolymer components other than terephthalic acid components and 1,4-butanediol components. In the present embodiment, a resin containing preferably 3 to 40% by mass, more preferably 5 to 30% by mass, and further preferably 10 to 25% by mass of copolymer components can also be used.

[0044] The intrinsic viscosity (IV) of polybutylene terephthalate resin is preferably more than 1.00dL / g, more preferably more than 1.10dL / g, further preferably more than 1.18dL / g, and further preferably more than 1.20dL / g. In addition, the above-mentioned intrinsic viscosity is preferably less than 1.50dL / g, more preferably less than 1.40dL / g, further preferably less than 1.35dL / g, further preferably less than 1.30dL / g, further preferably less than 1.28dL / g, further preferably less than 1.27dL / g, and particularly preferably less than 1.26dL / g. By being set to more than the above-mentioned lower limit, excellent toughness can be exerted. In addition, when being below the above-mentioned upper limit, the fluidity of the resin composition will not be lost, and the moldability tends to be excellent.

[0045] The intrinsic viscosity of the polybutylene terephthalate resin herein is a value measured at 30° C. in a mixed solvent of phenol / tetrachloroethane (mass ratio 1 / 1).

[0046] In addition, the terminal carboxyl amount of polybutylene terephthalate resin is usually below 60eq / ton, preferably below 50eq / ton, and more preferably below 30eq / ton. By being set to below 60eq / ton, alkali resistance and hydrolysis resistance are improved, and it is not easy to generate gas during the melt molding of resin composition. The lower limit of the terminal carboxyl amount is not particularly limited, but considering the manufacturing productivity of polybutylene terephthalate resin, it is usually 10eq / ton.

[0047] The amount of terminal carboxyl groups of the polybutylene terephthalate resin can be determined by dissolving 0.5 g of the resin in 25 mL of benzyl alcohol and titrating the mixture with a 0.01 mol / L benzyl alcohol solution of sodium hydroxide.

[0048] Polybutylene terephthalate resin can be a polybutylene terephthalate resin modified by copolymerization. As its specific preferred copolymer, polyalkylene glycols can be cited, especially polyester ether resins obtained by copolymerizing polytetramethylene glycol, dimer acid copolymerized polybutylene terephthalate resins, and isophthalic acid copolymerized polybutylene terephthalate resins. It should be noted that these copolymers refer to copolymers having a copolymerization amount of more than 1 mol% and less than 50 mol% in all segments of polybutylene terephthalate resin. Among them, the copolymerization amount is preferably 2 to 50 mol%, more preferably 3 to 40 mol%, and particularly preferably 5 to 20 mol%. These details can be referred to in paragraphs 0014 to 0022 of Japanese Patent Publication No. 2019-006866, and its content is incorporated into this specification.

[0049] The catalyst used in the esterification reaction may be a conventionally known one, for example, a titanium compound, a tin compound, a magnesium compound, a calcium compound, etc. Among them, a titanium compound is particularly preferred. Specific examples of the titanium compound as the esterification catalyst include titanium alkoxides such as tetramethyl titanate, tetraisopropyl titanate, and tetrabutyl titanate, and titanium phenolates such as tetraphenyl titanate.

[0050] The content of the polybutylene terephthalate resin in the resin composition of the present embodiment is preferably 30 parts by mass or more in 100 parts by mass of the resin component containing the polybutylene terephthalate resin, more preferably 40 parts by mass or more, further preferably 45 parts by mass or more, and further preferably 50 parts by mass or more. By setting it to above the above lower limit, there is a tendency that chemical resistance is further improved. In addition, the content of the above-mentioned polybutylene terephthalate resin is preferably 99 parts by mass or less, more preferably 90 parts by mass or less, further preferably 80 parts by mass or less, further preferably 70 parts by mass or less, and further preferably 60 parts by mass or less. By setting it to below the above upper limit, there is a tendency that the warpage amount of the molded body can be more effectively reduced.

[0051] The resin composition of the present embodiment may contain only one polybutylene terephthalate resin or may contain two or more polybutylene terephthalate resins. When containing two or more polybutylene terephthalate resins, the total amount is preferably within the above range.

[0052] <<Polycarbonate resin>>

[0053] The resin composition of the present embodiment may contain a polycarbonate resin in addition to the polybutylene terephthalate resin. By containing the polycarbonate resin, the impact resistance of the obtained molded body can be effectively improved. In addition, the molded body containing both the polybutylene terephthalate resin and the polycarbonate resin as resin components is prone to peeling when applying a water-based paint, but in the present embodiment, by containing the hydroxyl-containing compound, the peeling of the water-based paint can be effectively suppressed.

[0054] The polycarbonate resin can be obtained by reacting a dihydroxy compound or a small amount of a polyhydroxy compound with phosgene or a carbonic acid diester, and may have a branched chain, and may be a homopolymer or a copolymer. The method for producing the polycarbonate resin is not particularly limited, and polycarbonate resins produced by the conventionally known phosgene method (interfacial polymerization method) and melt method (ester exchange method) may be used.

[0055] The dihydroxy compound as a raw material is preferably an aromatic dihydroxy compound, and examples thereof include 2,2-bis(4-hydroxyphenyl)propane (=bisphenol A), tetramethylbisphenol A, bis(4-hydroxyphenyl)-p-diisopropylbenzene, hydroquinone, resorcinol, 4,4-dihydroxybiphenyl, and the like, and more preferably bisphenol A. In addition, a compound in which one or more tetraalkylphosphonium sulfonates are bonded to the above aromatic dihydroxy compounds may also be used.

[0056] As the polycarbonate resin, among the above, preferably, an aromatic polycarbonate resin derived from 2,2-bis(4-hydroxyphenyl)propane or an aromatic polycarbonate copolymer derived from 2,2-bis(4-hydroxyphenyl)propane and other aromatic dihydroxy compounds is used. In addition, a copolymer with a polymer or oligomer having a siloxane structure, etc., which is mainly composed of an aromatic polycarbonate resin, may also be used. Furthermore, two or more of the above polycarbonate resins may be used in combination.

[0057] In order to adjust the molecular weight of the polycarbonate resin, a monovalent aromatic hydroxy compound may be used, and examples thereof include m-cresol, p-cresol, m-propylphenol, p-propylphenol, p-tert-butylphenol, and p-long-chain alkyl-substituted phenol.

[0058] The viscosity average molecular weight (Mv) of the polycarbonate resin is preferably 10,000 or more, more preferably 15,000 or more, and further preferably 20,000 or more. By using a polycarbonate resin having a viscosity average molecular weight of 10,000 or more, there is a tendency that the mechanical strength of the obtained resin composition is further improved. In addition, the viscosity average molecular weight (Mv) of the polycarbonate resin is preferably 60,000 or less, more preferably 40,000 or less, and further preferably 30,000 or less. By using a polycarbonate resin of 60,000 or less, there is a tendency that the fluidity and moldability of the resin composition are improved.

[0059] In the present embodiment, the viscosity average molecular weight (Mv) of the polycarbonate resin refers to a value calculated from the viscosity of a dichloromethane solution of the polycarbonate resin measured at 20° C. using an Ubbelohde viscometer to determine the limiting viscosity ([η]) according to the following Schnell viscosity formula.

[0060] [η] = 1.23 × 10 -4 Mv 0.83

[0061] The method for producing the polycarbonate resin is not particularly limited, and any polycarbonate resin produced by a phosgene method (interfacial polymerization method) or a melt method (ester exchange method) can be used. In addition, a polycarbonate resin produced by a melt method and subjected to a post-treatment to adjust the amount of terminal OH groups is also preferred.

[0062] In 100 parts by mass of the resin component containing polybutylene terephthalate resin, the content of polycarbonate resin is preferably 1 part by mass or more, more preferably 10 parts by mass or more, further preferably 20 parts by mass or more, further preferably 30 parts by mass or more, further preferably 40 parts by mass or more. In addition, in 100 parts by mass of the resin component containing polybutylene terephthalate resin, the content of polycarbonate resin is preferably 70 parts by mass or less, more preferably 60 parts by mass or less, further preferably 55 parts by mass or less, further preferably 50 parts by mass or less. By setting such a content, the impact resistance of the molded body using the resin composition is improved, and warping can also be reduced.

[0063] The resin composition of the present embodiment may contain only one polycarbonate resin or two or more polycarbonate resins. When two or more polycarbonate resins are contained, the total amount is preferably within the above range.

[0064] The mass ratio of the polybutylene terephthalate resin to the polycarbonate resin is preferably 50 to 90 / 50 to 10, more preferably 50 to 70 / 50 to 30, and even more preferably 50 to 60 / 50 to 40.

[0065] The resin composition of the present embodiment may or may not contain resin components other than the polybutylene terephthalate resin and the polycarbonate resin.

[0066] When the resin composition of the present embodiment includes other resin components, styrene resins, polyethylene terephthalate resins, polyarylate resins, modified polyphenylene ether resins, and polyamide resins can be exemplified. The high molecular weight components in the components described in the elastomer and other additives described later are not included in the resin components of the present embodiment.

[0067] The resin component in the resin composition of the present embodiment preferably accounts for 90 mass % or more of the total of the polybutylene terephthalate resin and the polycarbonate resin, more preferably 95 mass % or more, further preferably 98 mass % or more, and further preferably 99 mass % or more.

[0068] In addition, the total content of the resin components in the resin composition is preferably 72% by mass or more of the resin composition, more preferably 75% by mass or more. In addition, the total content of the resin components in the resin composition is preferably 92% by mass or less of the resin composition, more preferably 90% by mass or less, further preferably 85% by mass or less, and even more preferably 84% by mass or less.

[0069] By setting it as the said range, the molded body with chemical resistance, impact resistance, and dimensional stability well-balanced can be obtained.

[0070] <<Elastomer>>

[0071] In the present embodiment, in order to improve the impact resistance of the molded article, an elastomer different from the resin component including the polybutylene terephthalate resin may be blended.

[0072] Examples of thermoplastic elastomers used for improving the impact resistance of a general molded product include a rubber polymer and a rubber polymer copolymerized with a compound reactive therewith.

[0073] Among the elastomers, epoxy group-containing elastomers (epoxy group-containing compounds) are preferred. By including an epoxy group-containing elastomer, not only the impact resistance of the molded body can be improved, but also the adhesion of the water-based paint can be effectively improved.

[0074] The first embodiment of the epoxy-containing elastomer is a copolymer obtained by copolymerizing α-olefins, glycidyl esters of α,β-unsaturated acids, and unsaturated monomers copolymerizable with them as needed. From the viewpoint of adhesion with water-based coatings, the content of glycidyl esters of α,β-unsaturated acids is preferably 1% by mass or more of all copolymer components, more preferably 3% by mass or more, and further preferably 5% by mass or more. There is no particular restriction on the upper limit, but from the perspective of operability, it is preferably 20% by mass or less of all copolymer components, more preferably 18% by mass or less, and further preferably 16% by mass or less.

[0075] Examples of α-olefins include ethylene, propylene, 1-butene, 1-pentene, and the like. Two or more of these may be used. Examples of glycidyl esters of α,β-unsaturated acids include glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, glycidyl itaconate, and the like. Two or more of these may be used. Examples of vinyl monomers copolymerizable with the above components include vinyl ethers, vinyl acetate, vinyl propionate, and other vinyl esters, methyl, ethyl, propyl, butyl, and other acrylic and methacrylic esters, acrylonitrile, styrene, and the like. Two or more of these may be used.

[0076] Preferred examples of epoxy-containing elastomers include ethylene / glycidyl methacrylate copolymers, ethylene / glycidyl methacrylate / vinyl acetate copolymers, ethylene / glycidyl methacrylate / alkyl acrylate copolymers, and ethylene / alkyl acrylate / vinyl acetate copolymers. In particular, ethylene / glycidyl methacrylate / alkyl acrylate (preferably butyl acrylate) copolymers are preferred from the viewpoint of excellent toughness and further improving the heat and humidity resistance and impact resistance of the molded body. Specific examples of epoxy-containing elastomers include "LOTADER" (registered trademark) AX8900 and AX8700 manufactured by Arkema.

[0077] In addition, elastomers other than the elastomer containing epoxy groups may be appropriately added. As these elastomers, copolymers of ethylene and unsaturated carboxylic acid esters (ethylene-methacrylate copolymers, ethylene-butyl acrylate copolymers, etc.), copolymers of ethylene and aliphatic vinyl compounds, terpolymers of ethylene, propylene and non-conjugated dienes, acrylic rubbers (polybutyl acrylate, poly(2-ethylhexyl acrylate), butyl acrylate-2-ethylhexyl acrylate copolymers, etc.), polybutadiene, polyisoprene, diene copolymers (styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, acrylic acid-butadiene rubbers, etc.), copolymers of ethylene and α-olefins having more than 3 carbon atoms (ethylene-propylene copolymers, ethylene-butene copolymers, ethylene-octene copolymers, etc.), silicone rubbers (polyorganosiloxane rubbers, IPN type composite rubbers composed of polyorganosiloxane rubbers and poly(meth)alkyl acrylate rubbers), etc. may be cited.

[0078] As other elastomers, core-shell elastomers can be cited. By using core-shell elastomers, there is a tendency that the adhesion with thermoplastic resins such as polybutylene terephthalate resins is excellent and the weld strength becomes higher due to the reactive compound contained in the core layer. The core-shell elastomer can be exemplified by the material obtained by grafting a copolymer component on the polymer of the core.

[0079] The core is preferably a rubber polymer, examples of which include acrylonitrile-acrylic rubber polymer-styrene graft copolymer (ASA resin), methyl methacrylate-acrylic rubber polymer-styrene graft copolymer (MSA resin), methyl methacrylate-acrylonitrile-acrylic rubber polymer-styrene graft copolymer (MASA resin), and rubber polymers containing polyorganosiloxane.

[0080] Specific examples of the monomer components that can be graft-copolymerized with the core include aromatic vinyl compounds, vinyl cyanide compounds, (meth)acrylate compounds, (meth)acrylic acid compounds, epoxy-containing (meth)acrylate compounds such as glycidyl (meth)acrylate, maleimide, N-methylmaleimide, N-phenylmaleimide and other maleimide compounds, maleic acid, phthalic acid, itaconic acid and other α, β-unsaturated carboxylic acid compounds, their anhydrides (such as maleic anhydride, etc.), etc.

[0081] As specific examples of rubber polymers, aromatic vinyl compounds, vinyl cyanide compounds, and (meth)acrylate compounds, reference can be made to paragraphs 0042 to 0046 of JP-A-2019-059813, the contents of which are incorporated herein by reference.

[0082] The melt flow rate (MFR) of the elastomer measured at 190°C and a load of 2.16 kgf in accordance with JIS K7210 is preferably 0.1 to 50 g / 10 min, more preferably 0.5 to 30 g / 10 min. When the MFR is within the above range, poor appearance is more effectively suppressed and impact resistance tends to be improved.

[0083] Relative to 100 parts by mass of the resin component containing polybutylene terephthalate resin, the content of the elastomer in the resin composition of the present embodiment is 2 parts by mass or more, preferably 3 parts by mass or more, more preferably 4 parts by mass or more, more preferably 5 parts by mass or more, can be 6 parts by mass or more, or can be 7 parts by mass or more. In addition, relative to 100 parts by mass of the resin component containing polybutylene terephthalate resin, the content of the elastomer in the resin composition of the present embodiment is 15 parts by mass or less, preferably 14 parts by mass or less, more preferably 13 parts by mass or less, more preferably 12 parts by mass or less, can be 11 parts by mass or less, can be 10 parts by mass or less, can be 9 parts by mass or less, or can be 8 parts by mass or less. By making the content of the elastomer within the above range, the toughness and impact resistance of the obtained molded body can be further improved without reducing the conductivity required for electrostatic coating.

[0084] The resin composition of the present embodiment may contain only one type of elastomer, or may contain two or more types. When containing two or more types, the total amount is preferably in the above range.

[0085] <<Hydroxy compounds>>

[0086] The hydroxyl-containing compound used in this embodiment is 1 The hydroxyl concentration represented by the ratio of the peak area derived from hydroxyl groups to the total peak area ((peak area derived from hydroxyl groups / total peak area)×100) in H NMR analysis is in the range of 0.5 to 15.0%. Such a hydroxyl-containing compound is used in the present embodiment to improve the coating adhesion of the water-based coating.

[0087] As the hydroxyl-containing compound, there is no particular limitation as long as the prescribed hydroxyl concentration is satisfied, and examples include known hydroxyl-containing oligomers and polymers, preferably hydroxyl-containing polymers. In these hydroxyl-containing oligomers and polymers, the content of polar groups other than the hydroxyl group is preferably less than 10 mol% of the hydroxyl group. By setting such a configuration, there is a tendency to more effectively exert the effect of the present invention.

[0088] Specific examples of the hydroxyl-containing compound include polyalkylene glycol, polyvinyl alcohol, (meth)acrylic acid compounds (preferably (meth)acrylic acid polymers), multi-branched polyester resins, etc. Among them, (meth)acrylic acid compounds are preferred, and (meth)acrylic acid polymers are particularly preferred in terms of their moderate compatibility with the polybutylene terephthalate resin.

[0089] The hydroxyl-containing compound used in the present embodiment can be a crystalline compound or an amorphous compound, preferably an amorphous compound. In the case of a crystalline resin, it is inferred that due to the molecular chain folding structure of the crystal part, the hydroxyl group is easily present between molecules, and the proportion of the hydroxyl group present in the surface part also decreases. In the case of an amorphous resin, there is a tendency that the molecular chain structure is randomized, the proportion of the hydroxyl group in the surface layer of the molded product also increases, and the coating adhesion can be more effectively exerted.

[0090] Amorphous compound refers to a compound that does not show a clear melting point when measured by differential scanning calorimetry (DSC). When using more than two hydroxy-containing compounds, at least one of the hydroxy-containing compounds contained in the preferred resin composition is an amorphous compound. In addition, when using more than two hydroxy-containing compounds, more than 80% by mass (and then more than 90% by mass) of the hydroxy-containing compounds contained in the preferred resin composition are amorphous compounds.

[0091] The hydroxyl concentration in the hydroxyl-containing compound is 0.5% or more, preferably 1.0% or more, and more preferably 1.2% or more. In addition, the upper limit of the above-mentioned hydroxyl concentration is 15.0% or less, preferably 12.0% or less, more preferably 10.0% or less, further preferably 9.0% or less, further preferably 7.0% or less, further preferably 5.0% or less, and further preferably 3.0% or less. By making the hydroxyl concentration below 0.5%, the adhesion of the water-based paint is improved, and by setting it to below 15.0% and further below 10.0%, it is possible to appropriately maintain compatibility with the polybutylene terephthalate resin, and it is not easy to be retained in the resin interior, and the adhesion and mechanical strength of the water-based paint can be improved. Furthermore, by using the hydroxyl-containing compound within the above range, the affinity between the surface of the molded body and the water-based paint can be improved, and the adhesion of the water-based paint during coating can be improved.

[0092] When the resin composition of the present embodiment contains two or more hydroxyl group-containing compounds, the hydroxyl group concentration is determined by calculating the hydroxyl group concentration of each compound and determining the average hydroxyl group concentration based on the mass ratio.

[0093] The concentration of hydroxyl groups in the hydroxyl-containing compound can be determined by dissolving the compound in a solvent. 1 The following formula representing the ratio of the peak area derived from the hydroxyl group to the total peak area in the analysis by H NMR was determined.

[0094] Hydroxyl concentration (%) = [(peak area derived from hydroxyl group (hydroxyl proton integrated value) / total peak area (total proton integrated value)) × 100]

[0095] The solvent used is preferably a good solvent in which the compound is sufficiently dissolved, and examples of the solvent used include dimethyl sulfoxide-d6, deuterated chloroform, deuterated tetrachloroethane, deuterated methanol, and the like.

[0096] When a plurality of hydroxy compounds are used, the amount is expressed as the sum of the products of the ratios of the amounts of the respective hydroxy compounds divided by the total amount of the hydroxy compounds and the concentrations of the respective hydroxy compounds.

[0097] Example: When hydroxy compound A and hydroxy compound B are used,

[0098] Hydroxyl concentration (%) = Hydroxyl concentration of hydroxy compound A (%) / (Hydroxy compound A mass parts / total hydroxy compound mass parts) + Hydroxyl concentration of hydroxy compound B (%) / (Hydroxy compound B mass parts / total hydroxy compound mass parts)

[0099] The acid value of the hydroxy-containing compound used in the present embodiment is preferably 200mgKOH / g or less, more preferably 100mgKOH / g or less, further preferably 50mgKOH / g or less, further preferably 30mgKOH / g or less, further preferably 15mgKOH / g or less, further preferably 10mgKOH / g or less. The lower limit of the above-mentioned acid value is usually 0mgKOH / g or more. By setting the acid value to less than 200mgKOH / g, there is a tendency that the impact resistance of the obtained molded body is further improved. In the case where the resin composition of the present embodiment includes more than two hydroxy-containing compounds, the above-mentioned acid value is set to the acid value of the mixture of hydroxy-containing compounds. The acid value is measured according to JIS K0070-1992.

[0100] The weight average molecular weight of the hydroxy-containing compound used in the present embodiment is preferably more than 1,500, more preferably more than 2,000, and in addition, preferably less than 30,000, more preferably less than 25,000, further preferably less than 20,000, further preferably less than 18,000, and further preferably less than 16,000. By setting the weight average molecular weight to more than 1,500, it is possible to suppress separation on the surface of the molded body, effectively suppressing the deterioration of the appearance of the molded body and mold contamination. In addition, by setting the weight average molecular weight to less than 30,000, the hydroxy-containing compound is not easily retained in the interior of the molded body, and the adhesion of the water-based paint can be further improved. That is, by using a hydroxy-containing compound within a preferred range, the hydroxy-containing compound can be appropriately floated to the surface of the molded body, and the adhesion of the water-based paint during coating can be more effectively improved.

[0101] In the present embodiment, in addition, the hydroxyl-containing compound is preferably a mixture of a compound having a weight average molecular weight of 1,500 to 5,000 (preferably 2,000 or more, preferably 4,000 or less, and more preferably 3,000 or less) and a compound having a weight average molecular weight of 10,000 to 30,000 (preferably 11,000 or more, more preferably 12,000 or more, further preferably 13,000 or more, and preferably 27,000 or less, more preferably 24,000 or less, further preferably 21,000 or less, further preferably 18,000 or less, and further preferably 16,000 or less). By setting such a structure, there is a tendency to more effectively exert the effect of the present invention. In particular, in the resin composition of the present embodiment, the mass ratio of the hydroxyl-containing compound having a weight average molecular weight of 1,500 to 5,000 and the hydroxyl-containing compound having a weight average molecular weight of 10,000 to 30,000 is preferably 1:1 to 1:4, and more preferably 1:1 to 1:3.

[0102] In the present embodiment, the ratio of the weight average molecular weight of the polybutylene terephthalate resin to the weight average molecular weight of the hydroxyl-containing compound (weight average molecular weight of the polybutylene terephthalate resin / weight average molecular weight of the hydroxyl-containing compound) is preferably 40 / 1 to 5 / 1, and more preferably 40 / 1 to 8 / 1. By setting it to be above the above lower limit, there is a tendency to suppress the delamination phenomenon near the gate and to improve the appearance. By setting it to be below the above upper limit, there is a tendency to improve the fluidity during molding.

[0103] Relative to 100 parts by mass of the resin component containing polybutylene terephthalate resin, the content of the hydroxy-containing compound used in the present embodiment is 3 parts by mass or more, preferably 4 parts by mass or more, more preferably 5 parts by mass or more, and according to the purpose, it can be 6 parts by mass or more, 7 parts by mass or more, 8 parts by mass or more, or 10 parts by mass or more. Relative to 100 parts by mass of the resin component containing polybutylene terephthalate resin, the content of the hydroxy-containing compound used in the present embodiment is 20 parts by mass or less, more preferably 18 parts by mass or less, and further, according to the purpose, it can be 16 parts by mass or less, 14 parts by mass or less, 12 parts by mass or less, 10 parts by mass or less, 9 parts by mass or less, or 8 parts by mass or less. By setting the content of the hydroxy-containing compound to the above range, the adhesion of the water-based coating can be further improved without reducing the impact resistance.

[0104] The resin composition of the present embodiment may contain only one hydroxyl group-containing compound or may contain two or more hydroxyl group-containing compounds. When two or more hydroxyl group-containing compounds are contained, the total amount is preferably within the above range.

[0105] <<Conductive Carbon>>

[0106] The resin composition of the present embodiment contains conductive carbon. By containing conductive carbon, the resistivity of the molded body is reduced, and electrostatic coating can be performed.

[0107] Examples of the conductive carbon include carbon black (eg, Ketjen black, furnace black, channel black, acetylene black), graphene, graphite, fullerene, carbon nanocoil, carbon nanotube, and carbon fiber. Carbon black is preferred, and Ketjen black is more preferred.

[0108] The number average primary particle size of the conductive carbon used in the present embodiment can be determined by appropriate selection, preferably 5 nm or more, more preferably 7 nm or more, and more preferably 10 nm or more. In addition, the above average particle size is preferably 60 nm or less, more preferably 55 nm or less, and more preferably 50 nm or less. By setting the number average primary particle size to the above range, there is a tendency to suppress the aggregation of conductive carbon and improve the appearance. It should be noted that the number average primary particle size of conductive carbon can be obtained using a transmission electron microscope. When conductive carbon is not a particle, it refers to the average primary particle size when converted to particles of the same volume.

[0109] The DBP absorption of the conductive carbon used in this embodiment is preferably 300 cm 3 There is no particular upper limit, but it is preferably 1000 cm 3 / 100g or less. By making the DBP absorption amount 300cm 3 / 100g or more, it is possible to impart good conductivity to the resin composition with a smaller addition amount. It should be noted that the DBP absorption can be measured according to JIS K6217 (unit: cm 3 / 100g).

[0110] The conductive carbon used in this embodiment preferably has a nitrogen adsorption specific surface area of ​​600 m 2 / g or more, preferably 800 m 2 There is no particular upper limit, but from the perspective of operability, it is preferably 1500 m 2 / g or less, more preferably 1300m 2 / g or less. By making the nitrogen adsorption specific surface area 600m 2 / g or more, it is possible to suppress the reduction of mechanical properties and impart conductivity to the molded body. It should be noted that the nitrogen adsorption specific surface area can be measured according to JIS K6217 (unit: m 2 / g).

[0111] The pH of the conductive carbon used in the present embodiment is also not particularly limited, and is usually 2 or more, preferably 3 or more, and more preferably 4 or more. The pH is 10 or less, preferably 9 or less, and more preferably 8 or less.

[0112] The content of the conductive carbon used in this embodiment is 3 parts by mass or more, more preferably 4 parts by mass or more, and more preferably 5 parts by mass or more, and can be 6 parts by mass or more, 7 parts by mass or more, 8 parts by mass or more, or 10 parts by mass or more, relative to 100 parts by mass of the resin component containing polybutylene terephthalate resin. In addition, the content of the conductive carbon is 20 parts by mass or less, more preferably 19 parts by mass or less, and more preferably 18 parts by mass or less, and further, according to the use, it can be 17 parts by mass or less, 16 parts by mass or less, 14 parts by mass or less, 12 parts by mass or less, 10 parts by mass or less, 9 parts by mass or less, or 8 parts by mass or less, relative to 100 parts by mass of the resin component containing polybutylene terephthalate resin. By setting the content of the conductive carbon to the above range, it is possible to impart conductivity to the molded body while maintaining mechanical properties.

[0113] The resin composition of the present embodiment may contain only one type of conductive carbon or two or more types. When containing two or more types, the total amount is preferably in the above range.

[0114] <<Stabilizer>>

[0115] The resin composition of the present embodiment may contain a stabilizer such as an antioxidant.

[0116] By using a stabilizer, the decomposition caused by the transesterification reaction of polybutylene terephthalate resin and polycarbonate resin can be suppressed, and the physical properties and appearance are improved. As the stabilizer, phenol stabilizers, amine stabilizers, phosphorus stabilizers, thioether stabilizers, etc. can be cited. In the present embodiment, phosphorus stabilizers and / or phenol stabilizers are preferred, and more preferably both phosphorus stabilizers and phenol stabilizers are included.

[0117] In particular, when a polycarbonate resin is used, it is preferred to mix a phosphorus-based stabilizer.

[0118] As the phosphorus stabilizer, any known phosphorus stabilizer can be used. Specific examples include phosphorus oxygen acids such as phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, and polyphosphoric acid; acidic pyrophosphate metal salts such as acidic sodium pyrophosphate, acidic potassium pyrophosphate, and acidic calcium pyrophosphate; phosphates of Group 1 or Group 2B metals such as potassium phosphate, sodium phosphate, cesium phosphate, and zinc phosphate; organic phosphate compounds, organic phosphite compounds, and organic phosphonite compounds, and organic phosphate compounds are particularly preferred.

[0119] As the phenolic stabilizer, a hindered phenolic stabilizer is preferably used. Specific examples of the hindered phenolic stabilizer include pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], 2,4-dimethyl-6-(1-methylpentadecyl)phenol, diethyl[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphate, 3,3',3",5,5',5"-hexa-tert-butyl-a,a',a"-(all 1,2-dimethyl-6-(1,2-dimethyl ...,2-dimethyl-4-hydroxyphenyl)propionamide, 2,4-dimethyl-6-(1,2-dimethyl-4-hydroxyphenyl)propionamide, 2,4-dimethyl-6-(1,2-dimethyl-4-hydroxyphenyl)propionamide, 2,4-dimethyl-6-(1,2-dimethyl-4-hydroxyphenyl)propionamide, 2,4-dimethyl-6-(1, Trimethylol-2,4,6-triyl) tri-p-cresol, 4,6-bis(octylmethylthio)-o-cresol, ethylenebis(oxyethylene)bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], hexamethylenebis[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-triazine-2-ylamino)phenol, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate, etc.

[0120] Among them, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are preferred. Specific examples of such hindered phenol stabilizers include "Irganox (registered trademark, hereinafter the same) 1010" and "Irganox 1076" manufactured by BASF, and "Adekastab AO-50" and "Adekastab AO-60" manufactured by ADEKA.

[0121] When a stabilizer is contained, the content thereof is preferably in the range of 0.01 to 5% by mass of the resin composition.

[0122] In particular, when the resin composition of the present embodiment contains a phosphorus-based stabilizer, the content thereof is preferably 0.05 parts by mass or more, more preferably 0.06 parts by mass or more, further preferably 0.08 parts by mass or more, and further preferably 0.10 parts by mass or more, relative to 100 parts by mass of the resin component. In addition, it is preferably 2 parts by mass or less, more preferably 1.5 parts by mass or less, further preferably 1.0 parts by mass or less, further preferably 0.7 parts by mass or less, further preferably 0.5 parts by mass or less, further preferably 0.3 parts by mass or less, further preferably 0.2 parts by mass or less, and further preferably 0.15 parts by mass or less.

[0123] In particular, when the resin composition of the present embodiment contains a phenolic stabilizer, the content thereof is preferably 0.1 parts by mass or more, more preferably 0.2 parts by mass or more, further preferably 0.25 parts by mass or more, and further preferably 0.3 parts by mass or more, relative to 100 parts by mass of the resin component, and is preferably 2 parts by mass or less, more preferably 1.5 parts by mass or less, further preferably 1.0 parts by mass or less, further preferably 0.7 parts by mass or less, and further preferably 0.5 parts by mass or less.

[0124] When a phosphorus stabilizer and a phenol stabilizer are used in combination, the mass ratio of the phosphorus stabilizer to the phenol stabilizer is preferably 1 / 0.5 to 5.

[0125] The resin composition of the present embodiment may contain only one stabilizer or two or more stabilizers. When two or more stabilizers are contained, the total amount is preferably within the above range.

[0126] <<Other additives>>

[0127] The resin composition of the present embodiment may also include resin additives other than those mentioned above. Specifically, it may include a release agent (polyethylene wax, oxidized polyethylene wax, silicone oil, fluorine resin, fatty acid, fatty acid ester, fatty acid metal salt, etc.), a flame retardant (phosphorus flame retardant, halogen flame retardant, organic metal flame retardant, etc.), an internal lubricant (fatty acid metal salt, polyethylene wax, etc.), a reinforcing material (carbon fiber, glass fiber, talc, mica, etc.), a dye, a weathering improver, a nucleating agent, a plasticizer, a fluidity improver, etc.

[0128] When other components are contained, the total content thereof is preferably in the range of 0.01 to 10% by mass of the resin composition.

[0129] The resin composition of the present embodiment is adjusted so that the total of the polybutylene terephthalate resin, the polycarbonate resin, the elastomer, the hydroxyl group-containing compound, the conductive carbon, and other components optionally blended is 100% by mass.

[0130] The resin composition of the present embodiment is adjusted to a total of 100 mass% of polybutylene terephthalate resin, polycarbonate resin, elastomer, hydroxyl-containing compound and conductive carbon and other selectively matched components. In addition, the total of polybutylene terephthalate resin, polycarbonate resin, elastomer, hydroxyl-containing compound and conductive carbon preferably accounts for more than 90 mass% of the resin composition, more preferably more than 94 mass%, and further preferably more than 96 mass%. Furthermore, the total of polybutylene terephthalate resin, polycarbonate resin, elastomer, hydroxyl-containing compound, conductive carbon, stabilizer and release agent preferably accounts for more than 95 mass% of the resin composition, more preferably more than 97 mass%, and further preferably more than 99 mass%.

[0131] <Method for producing resin composition>

[0132] The method for manufacturing the resin composition of the present embodiment is not limited to a specific method, and examples thereof include a method of mixing components such as polybutylene terephthalate resin, polycarbonate resin, elastomer, hydroxyl-containing compound, conductive carbon, and then melt-kneading. The melt-kneading method can be performed by a method commonly used for thermoplastic resins.

[0133] As a melt-mixing method, for example, the above-mentioned essential components and other components prepared as needed are uniformly mixed using a Henschel mixer, a ribbon mixer, a V-type mixer, a rotary drum, etc., and then melt-mixed using a single screw or multi-screw mixing extruder, a roller, a Banbury mixer, a Labo Plastomill (Brabender), etc. In the case of adding a reinforcing material, it is possible to suppress the loss of the reinforcing material and disperse it by supplying it from the side feeder of the mixing extruder, so it is preferred. The temperature and mixing time during melt-mixing can be selected according to the type of components constituting the resin component, the ratio of the components, the type of the melt-mixing machine, etc., and the temperature during melt-mixing is preferably in the range of 200 to 300°C. By being set to below 300°C, the thermal degradation of each component is not easy to become a problem, and there is a tendency that the physical properties of the obtained molded body are improved, and in addition, there is a tendency that the appearance is improved.

[0134] <Volume resistivity>

[0135] The resin composition of the present embodiment is molded into a 3 mm thick test piece, and the volume resistivity measured according to IEC60093 is preferably 1.0×10 14 Ω·cm or less, more preferably less than 1.0×10 12 Ω·cm. The lower limit is not particularly limited, but is practically 1.0×10 10When the volume resistivity of the resin composition is within the above range, electrostatic coating becomes easier.

[0136] <Method for producing molded article>

[0137] The molded article of the present embodiment is formed from the resin composition of the present embodiment.

[0138] The manufacturing method of the molded body in the present embodiment is not particularly limited, and the molding method commonly used for the resin composition can be arbitrarily adopted. As its example, the hollow molding methods such as injection molding, ultra-high speed injection molding, injection compression molding, two-color molding, gas-assisted, the molding method using a heat-insulating mold, the molding method using a rapid heating mold, foam molding (also including supercritical fluid), insert molding, IMC (in-mold coating molding) molding method, extrusion molding, sheet molding, thermoforming, rotational molding, stacking molding, compression molding, blow molding, etc. can be cited. In addition, the molding method using a hot runner mode can also be adopted.

[0139] <Purpose>

[0140] The resin composition and molded article of this embodiment are suitable for a wide range of uses such as interior parts and exterior parts of vehicles and aircraft, electric / electronic / OA equipment parts, mobile phones, machine parts, building components, leisure products and sundries.

[0141] Specifically, for example, automobile exterior parts include outside handles, door mirror brackets, fenders, decorative parts, bumpers, roof beams, wiper arms, etc., and automobile interior parts include inside handles, center consoles, instrument panels, auxiliary handles, seat belt buckles, etc.

[0142] In addition, rail vehicle parts include table-top handrails, hanging rings, auxiliary handles, etc., and electrical parts include razor frames, dryers, refrigerator handles and pulls, microwave oven doors, portable MD system handles, earphone arms, electric screwdriver housings, etc. Moreover, building material parts include door handles, crescent locks, latches, etc.

[0143] The resin composition of the present embodiment can be electrostatically coated in water-based paint, and is therefore used for the formation of a molded body of electrostatically coated water-based paint. The resin composition and molded body of the present embodiment are particularly preferably used for automotive exterior parts such as fuel oil port cover parts. As water-based paint, water-based polyurethane paint and water-based acrylic paint can be exemplified, which are particularly suitable for water-based polyurethane paint. It is speculated that this is because the carbamate raw material of the water-based polyurethane paint, i.e., the residual isocyanate reacts with the hydroxyl group of the hydroxy-containing compound to further improve adhesion. That is, in the present embodiment, a molded body having the present embodiment and a water-based paint layer coated on its surface (preferably electrostatically coated) and a molded body having a paint layer can be provided.

[0144] In addition, a kit using the resin composition of the present embodiment and a water-based polyurethane coating is preferred. The kit is particularly preferably used as a kit for a fuel cap.

[0145] Example

[0146] The present invention is described in more detail below by enumerating examples. The materials, usage, ratio, processing contents, processing steps, etc. shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

[0147] When the measuring equipment used in the examples is difficult to obtain due to discontinuation of production or the like, other equipment having equivalent performance may be used for the measurement.

[0148] <Raw materials used>

[0149] [Table 1]

[0150]

[0151] [Table 2]

[0152]

[0153] <Determination of Hydroxyl Concentration of Hydroxyl-Containing Compounds>

[0154] 14.2 g of the hydroxyl-containing compound was dissolved in 0.5 mL of dimethyl sulfoxide-d6 and the mixture was prepared by Bruker. 1 In the case of HNMR (AVANCE III) analysis, the hydroxyl concentration was determined from the following formula representing the ratio of the peak area derived from the hydroxyl group to the total peak area.

[0155] Hydroxyl concentration (%) = [(peak area derived from hydroxyl group (hydroxyl proton integrated value) / total peak area (total proton integrated value)) × 100]

[0156] When a plurality of hydroxy compounds are used, the amount is expressed as the sum of the products of the ratios of the amounts of the respective hydroxy compounds divided by the total amount of the hydroxy compounds and the concentrations of the respective hydroxy compounds.

[0157] Example: When hydroxy compound A and hydroxy compound B are used,

[0158] Hydroxyl concentration (%) = Hydroxyl concentration of hydroxy compound A (%) / (mass part of hydroxy compound A / mass part of all hydroxy compounds) + Hydroxyl concentration of hydroxy compound B (%) / (mass part of hydroxy compound B / mass part of all hydroxy compounds)

[0159] Examples 1 to 4, Comparative Examples 1 to 6

[0160] <Compound>

[0161] The components were weighed so as to have the composition shown in the table described later (each component is in parts by mass), uniformly mixed using a tumbler, and then supplied to a twin-screw extruder ("TEX30α", manufactured by The Nippon Steel Works, Ltd., L / D=42), and kneaded under the conditions of a screw speed of 200 rpm, a discharge volume of 30 kg / hour, and a barrel temperature of 250°C. The molten resin extruded into a strand shape was quenched in a water tank and pelletized using a pelletizer to obtain pellets of the resin composition.

[0162] <Tensile strength at break (MPa), tensile elongation at break (%)>

[0163] The pellets obtained by the above-mentioned manufacturing method were dried at 120°C for 6 hours, and then injection molded using an injection molding machine manufactured by Nippon Steel Works, Ltd. (mold clamping force 85T) at a barrel temperature of 250°C and a mold temperature of 80°C to produce ISO3167:93A type test pieces (hereinafter referred to as "ISO test pieces").

[0164] According to ISO-527, the tensile strength at break (unit: MPa) and the tensile elongation at break (unit: %) were measured using the ISO test pieces obtained above.

[0165] <Maximum flexural strength (MPa) and flexural modulus (MPa)>

[0166] Using a 80 mm x 10 mm x 4 mm long test piece produced by machining the parallel portion of the ISO test piece, the maximum bending strength (unit: MPa) and the bending modulus (unit: MPa) were measured in an environment of 23°C and 50% humidity in accordance with ISO-178.

[0167] <Notched Charpy impact strength (kJ / m 2 )>

[0168] According to ISO-179-1 and ISO179-2, the ISO test piece obtained above was cut to remove the clamping parts at both ends and to set a notch (notch) in the center to form a notched Charpy impact test piece. For the obtained notched Charpy impact test piece, as an impact resistance evaluation, the notched Charpy impact strength (unit: kJ / m) at 23°C was measured according to ISO-179-1 and ISO179-2. 2 ).

[0169] <Strength Judgment>

[0170] A: All meet the requirements of tensile strength at break of 50MPa or more, maximum bending strength of 75MPa or more, and notched Charpy impact strength of 12kJ / m 2 .

[0171] B: does not meet the conditions of A, but meets the following requirements: tensile strength at break of 45 MPa or more, maximum bending strength of 70 MPa or more, notched Charpy impact strength of 10 kJ / m 2 .

[0172] C: does not meet the conditions of A and B.

[0173] <Deflection temperature under load (°C)>

[0174] In accordance with ISO-75-1, a strip-shaped test piece of 80 mm×10 mm×4 mmt produced by machining the parallel portion of the above-mentioned ISO test piece was used to measure the load deflection temperature (unit: °C) under a load of 1.80 MPa.

[0175] <Volume resistivity>

[0176] The pellets obtained by the above production method were dried at 120°C for 6 hours and then injection molded using an injection molding machine ("NEX80" manufactured by Nissei Plastic Industry Co., Ltd.) at a cylinder temperature of 260°C and a mold temperature of 80°C to form a 100 mm×100 mm×3 mm flat test piece.

[0177] The volume resistivity of the test piece obtained by the above molding method was measured in accordance with IEC 60093. The unit of volume resistivity is expressed in Ω·cm.

[0178] As the resistivity meter for the volume specific resistance, a product number R8340A manufactured by Advantest was used.

[0179] <Conductivity Determination>

[0180] A: Volume resistivity is less than 1.0×10 12 Ω·cm

[0181] B: Volume resistivity is 1.0×10 12 Ω·cm or more and 1.0×10 14 Ω·cm or less

[0182] C: Volume resistivity exceeds 1.0×10 14 Ω·cm

[0183] <Paintability>

[0184] Wipe the surface of the test piece of 100mm×100mm×2mmt size with isopropyl alcohol, degrease it, apply a general automotive body paint (made by BASF), and sinter it at 140°C for 20 minutes. After sintering, perform a 100-block checkerboard peeling test according to the method of JISK5600. Use a cutting knife to carve 11 cuts in the vertical and horizontal directions at intervals of 2mm on the painted surface, paste a transparent adhesive tape on it, rub the adhesive tape with your fingertips, and peel the transparent adhesive tape upward in one breath within 5 minutes. Perform it a total of 3 times in the vertical and horizontal directions, and then record the number of squares with paint remaining on the painted surface.

[0185] <Painting judgment>

[0186] A: In the coating test, there is no peeling of the grid

[0187] B: In the coating test, the number of squares with coating residue is more than 85.

[0188] C: In the coating test, the number of squares with coating residue is less than 85

[0189] [Table 3]

[0190]

[0191] [Table 4]

[0192]

[0193] From the above results, it can be seen that the water-based coating of the resin composition of the present embodiment has excellent coating adhesion. It can also be seen that since the volume specific resistance is also low, it is suitable for use in fuel caps and other applications requiring electrostatic coating. Furthermore, the various mechanical strengths and heat resistance of the molded body obtained from the resin composition of the present embodiment are also excellent.

Claims

1. A resin composition, wherein The present invention comprises 2 to 15 parts by mass of an elastomer, 3 to 20 parts by mass of a hydroxyl-containing compound and 3 to 20 parts by mass of conductive carbon, relative to 100 parts by mass of a resin component comprising a polybutylene terephthalate resin. The hydroxyl-containing compound is 1 The hydroxyl concentration represented by the ratio of the peak area derived from hydroxyl groups to the total peak area in H NMR analysis, i.e. [(peak area derived from hydroxyl groups / total peak area)×100], was in the range of 0.5 to 15.0%.

2. The resin composition according to claim 1, wherein The resin component further includes a polycarbonate resin.

3. The resin composition according to claim 2, wherein The present invention further contains 0.05 to 2 parts by mass of a phosphorus-based stabilizer based on 100 parts by mass of the resin component.

4. The resin composition according to any one of claims 1 to 3, wherein The intrinsic viscosity of the polybutylene terephthalate resin is 1.00 to 1.50 dL / g.

5. The resin composition according to any one of claims 1 to 4, wherein The elastomer comprises an epoxy-containing compound.

6. The resin composition according to any one of claims 1 to 5, wherein The weight average molecular weight of the hydroxyl-containing compound is 1,500 to 30,000.

7. The resin composition according to any one of claims 1 to 6, wherein The hydroxyl group-containing compound includes a (meth)acrylic acid compound.

8. The resin composition according to any one of claims 1 to 7, wherein The hydroxyl-containing compound is an amorphous compound.

9. The resin composition according to any one of claims 1 to 8, wherein The hydroxyl concentration of the hydroxyl-containing compound is in the range of 0.5 to 10.0%. 10 . The resin composition according to claim 1 , which is used for forming a molded body for electrostatic coating of a water-based paint. 11 . A molded product formed from the resin composition according to claim 1 .

12. The molded article according to claim 11, which is a fuel filler cap.

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