Thermoplastic resin composition for millimeter wave radar member, molded body, and method for producing resin composition

Abstract

The present application relates to a thermoplastic resin composition for a millimeter wave radar member, a molded body, and a method for producing the resin composition. A thermoplastic resin composition for a millimeter wave radar member, characterized by containing, relative to 100 parts by mass of a polybutylene terephthalate resin (A), 15 to 65 parts by mass of a rubber-reinforced polystyrene-based resin (B1) and / or 10 to 70 parts by mass of a polycarbonate resin (B2) as a component (B), 0.1 to 3 parts by mass of an epoxy compound (D), and 30 to 150 parts by mass of a glass fiber (E).

Description

[0001] This application is a divisional application of the application with the application number 202080037010.6, the application date of May 15, 2020, and the title of Thermoplastic resin composition for millimeter wave radar member, molded body, and method for producing resin composition. TECHNICAL FIELD

[0002] The present application relates to a thermoplastic resin composition for millimeter wave radar member; a molded body; and a method for producing a resin composition, more specifically to a thermoplastic resin composition for millimeter wave radar member, which has a low relative dielectric constant, a small deviation in the relative dielectric constant of the resulting molded body, excellent low warpage and appearance, exhibits excellent strength and rigidity, exhibits high transmittance, and exhibits excellent laser welding property; a molded body composed thereof; and a method for producing a resin composition. BACKGROUND

[0003] A millimeter wave radar detects the presence of an obstacle by emitting electromagnetic waves in the millimeter wave band and receiving reflected waves that return after the emitted millimeter waves hit the obstacle, and has the feature of being strong in the night and in bad weather with poor visibility, compared to other methods for detecting obstacles (laser radar by optical system, and camera, etc.), and is less affected by rain, fog, and backlight, etc., and is used for automobile collision avoidance sensors, driving support systems, automatic driving systems, and road information providing systems, etc.

[0004] A millimeter wave radar has an antenna unit built-in, and a millimeter wave radar cover is attached in front of the transmitting and receiving antennas to protect the antenna surface. If the millimeter wave radar cover does not exhibit sufficient millimeter wave transmittance, it cannot accurately detect obstacles, etc., because the transmitted millimeter waves and reflected waves from the transmitting and receiving antennas are attenuated, and the required performance of the millimeter wave radar cannot be achieved. A low relative dielectric constant is required to reduce millimeter wave transmittance.

[0005] Patent Document 1 indicates that a polybutylene terephthalate resin composition of a polybutylene terephthalate resin and a cyclic olefin resin having a glass transition temperature of 100°C or higher is suitable for use as a millimeter wave radar antenna cover (radome). However, in recent years, polybutylene terephthalate resin compositions containing such a cyclic olefin resin as a millimeter wave radar member material require further improvement.

[0006] Specifically, in recent years, resin materials for millimeter wave radar members require an extremely high level of performance, not only in excellent dielectric properties such as low relative dielectric constant, etc., but also in low warpage, excellent appearance, and excellent strength and rigidity. Furthermore, there is a need for no change in the performance of the molded body obtained by molding.

[0007] For example, in recent years, in many cases, when manufacturing a millimeter wave radar member, a millimeter wave radar cover is brought into direct contact with an outer shell formed of a resin molded product and is laser-welded, requiring high laser light transmission and excellent laser-welding properties.

[0008] Prior Art Documents

[0009] Patent Documents

[0010] [Patent Document 1] JP 2013-43942 A SUMMARY

[0011] Problem to be solved by the invention

[0012] An object (problem to be solved by the invention) of the present invention is to provide a thermoplastic resin composition for a millimeter wave radar member, which has a low relative dielectric constant, a small deviation in the relative dielectric constant of the obtained molded body, low warpage, and excellent appearance, exhibits excellent strength and rigidity, exhibits high transmittance, and exhibits excellent laser-welding properties; a molded body formed thereof; and a manufacturing method of a thermoplastic resin composition for a millimeter wave radar member.

[0013] Solution for solving the problem

[0014] As a result of conducting intensive research to solve the above-described problems, the inventors of the present invention found that the above-described problems can be solved by obtaining a thermoplastic resin composition by blending a polybutylene terephthalate resin with a rubber-reinforced polystyrene-based resin and a polycarbonate resin, or with a polycarbonate resin, and further mixing in a specific amount of an epoxy compound and glass fibers, thereby completing the present invention.

[0015] The present invention relates to a thermoplastic resin composition for a millimeter wave radar member; a molded body formed thereof; and a manufacturing method of a thermoplastic resin composition.

[0016] [1] A thermoplastic resin composition for a millimeter wave radar member, comprising, with respect to 100 parts by mass of a polybutylene terephthalate resin (A), 15 to 65 parts by mass of a rubber-reinforced polystyrene-based resin (B1) and / or 10 to 70 parts by mass of a polycarbonate resin (B2) as a component (B), 0.1 to 3 parts by mass of an epoxy compound (D), and 30 to 150 parts by mass of glass fibers (E).

[0017] [2] The thermoplastic resin composition according to the above-mentioned [1], wherein the component (B) is a rubber-reinforced polystyrene-based resin (B1), and with respect to 100 parts by mass of the polybutylene terephthalate resin (A), the composition comprises 10 to 60 parts by mass of a styrene-maleic anhydride copolymer (C).

[0018] [3] The thermoplastic resin composition according to the above [1], comprising, with respect to 100 parts by mass of the polybutylene terephthalate resin (A), the following as a component (B):

[0019] (i) 15 to 65 parts by mass of the rubber-reinforced polystyrene-based resin (B1) and 10 to 60 parts by mass of the polycarbonate resin (B2), or

[0020] (ii) 10 to 70 parts by mass of the polycarbonate resin (B2).

[0021] [4] The thermoplastic resin composition according to any one of the above [1] to [3], further comprising 0.0005 to 0.5 parts by mass of a laser light-transmissive dye (F) with respect to 100 parts by mass of the polybutylene terephthalate resin (A).

[0022] [5] The thermoplastic resin composition according to any one of the above [1] to [4], wherein carbon black is not contained, or even if contained, the content of carbon black is 0.1 parts by mass or less with respect to 100 parts by mass of the polybutylene terephthalate resin (A).

[0023] [6] The thermoplastic resin composition according to any one of the above [1] to [5], wherein the sizing agent or surface treatment agent of the glass fiber (E) is a novolak-type epoxy compound.

[0024] [7] A molded body obtained by molding the thermoplastic resin composition according to any one of the above [1] to [6].

[0025] [8] The molded body according to the above [7], having a relative dielectric constant of 3.50 or less.

[0026] [9] The molded body according to the above [7] or [8], wherein the difference between the maximum value and the minimum value of the relative dielectric constant of at least 10 molded bodies is 0.07 or less.

[0027]

[10] The molded body according to any one of the above [7] to [9], wherein the molded body is a millimeter wave radar member.

[0028]

[11] The molded body according to any one of the above [7] to

[10] , which is used for a transmission side at the time of laser welding.

[0029]

[12] A millimeter wave radar member obtained by connecting the molded body according to any one of the above [7] to

[10] and a resin molded product as a mating material by means of laser welding.

[0030]

[13] A method for producing a thermoplastic resin composition for a millimeter wave radar member, which is a method for producing the thermoplastic resin composition according to any one of the above-mentioned [1] to [6] by using a twin-screw kneading extruder, the method comprising feeding at least components (A), (B1), (B2), and (C) to a base portion of the twin-screw kneading extruder and side-feeding the glass fiber (E) thereto, and kneading at a screw kneading temperature of 200°C or lower.

[0031] Effects of the invention

[0032] The thermoplastic resin composition for a millimeter wave radar member of the present application has a low relative dielectric constant, a small deviation in the relative dielectric constant of the resulting molded body, achieves an excellent balance between low relative dielectric constant, low warpage, and appearance, exhibits excellent low warpage and appearance, exhibits excellent strength and rigidity, has high transmittance and exhibits excellent laser welding properties, and thus can be advantageously used as a millimeter wave radar member.

[0033] Further, the method for producing a thermoplastic resin composition according to the present application can easily and stably produce a thermoplastic resin composition for a millimeter wave radar member having a low relative dielectric constant and a small deviation in the relative dielectric constant of the resulting molded body, exhibiting excellent low warpage and appearance, and exhibiting excellent strength and rigidity. BRIEF DESCRIPTION OF DRAWINGS

[0034] [ Figure 1 ] Figure 1 is an appearance view of a laser welding body for measuring laser welding properties in Examples and Comparative Examples. DETAILED DESCRIPTION

[0035] Hereinafter, the embodiments of the present application will be explained in detail. The explanations given below are based on the embodiments and specific examples, but it should be understood that the present application is not limited to these embodiments and specific examples.

[0036] Further, in the case where the preposition "to" is used in the present specification to indicate a range of values or physical property values encompassing the values before and after "to", the range includes the values before and after "to".

[0037] The thermoplastic resin composition for a millimeter wave radar member of the present application, characterized by comprising, with respect to 100 parts by mass of a polybutylene terephthalate resin (A), 15 to 65 parts by mass of a rubber-reinforced polystyrene-based resin (B1) and / or 10 to 70 parts by mass of a polycarbonate resin (B2) as a component (B), 0.1 to 3 parts by mass of an epoxy compound (D), and 30 to 150 parts by mass of a glass fiber (E).

[0038] [(A) polybutylene terephthalate resin]

[0039] The thermoplastic resin composition of the present application comprises a polybutylene terephthalate resin (A).

[0040] The polybutylene terephthalate resin is a polyester resin having a structure in which terephthalic acid units and 1,4-butanediol units are bonded via ester bonds, and includes, in addition to polybutylene terephthalate resins (homopolymers), polybutylene terephthalate copolymers containing other copolymer components in addition to terephthalic acid units and 1,4-butanediol units, and mixtures of homopolymers and such copolymers.

[0041] The polybutylene terephthalate resin can contain other dicarboxylic acid units in addition to terephthalic acid, and specific examples of these other dicarboxylic acid units include aromatic dicarboxylic acids such as isophthalic acid, phthalic acid, 1,5-naphthalene dicarboxylic acid, 2,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, biphenyl-2,2'-dicarboxylic acid, biphenyl-3,3'-dicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, bis(4,4'-carboxyphenyl)methane, anthracene dicarboxylic acid, and 4,4'-diphenyl ether dicarboxylic acid; alicyclic dicarboxylic acids such as 1,4-cyclohexane dicarboxylic acid and 4,4'-dicyclohexane dicarboxylic acid; and aliphatic dicarboxylic acids such as adipic acid, sebacic acid, and azelaic acid and dimer acid.

[0042] When the polybutylene terephthalate resin (A) contains other diol units in addition to 1,4-butanediol, specific examples of these other diol units include aliphatic and alicyclic diols and bisphenol derivatives having a carbon number of 2 to 20. Specific examples thereof include ethylene glycol, propylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, decamethylene glycol, cyclohexane dimethanol, 4,4'-dicyclohexylhydroxymethane, 4,4'-dicyclohexylpropanol, and ethylene oxide addition diols of bisphenol A. In addition to difunctional monomers such as those described above, a small amount of a trifunctional monomer such as trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, or trimethylolpropane can be additionally used to introduce a branched structure, or a monofunctional compound such as a fatty acid can be used to adjust the molecular weight.

[0043] As described above, the polybutylene terephthalate resin is preferably a polybutylene terephthalate homopolymer obtained by polycondensation of terephthalic acid and 1,4-butanediol, but can also be a polybutylene terephthalate copolymer containing one or more kinds of dicarboxylic acids other than terephthalic acid as a carboxylic acid unit and / or one or more kinds of diols other than 1,4-butanediol as a diol unit, and in the case where the polybutylene terephthalate resin is a polybutylene terephthalate resin modified by copolymerization, examples of the preferred specific copolymer include a polyester-ether resin obtained by copolymerization with a polyalkylene glycol, particularly polytetramethylene glycol, a dimer acid copolymerized polybutylene terephthalate resin, and an isophthalic acid copolymerized polybutylene terephthalate resin. Among these, use of a polyester-ether resin obtained by copolymerization with polytetramethylene glycol is preferred.

[0044] Further, in these copolymers, the copolymerization amount is 1 mol% or more and less than 50 mol% in all segments of the polybutylene terephthalate resin. Within this range, the copolymerization amount is preferably 2 mol% or more and less than 50 mol%, more preferably 3 to 40 mol%, and particularly preferably 5 to 20 mol%. From the viewpoint of improving flowability, toughness, and tracking resistance, such a copolymerization ratio is preferred.

[0045] The amount of terminal carboxyl groups in the polybutylene terephthalate resin should be appropriately selected and determined, and is generally 60 eq / ton or less, preferably 50 eq / ton or less, and more preferably 30 eq / ton or less. If this amount exceeds 50 eq / ton, the alkali resistance and hydrolysis resistance deteriorate, and gas tends to be generated during melt molding of the resin composition. The lower limit value of the amount of terminal carboxyl groups is not particularly limited, but from the viewpoint of productivity in the production of the polybutylene terephthalate resin, it is generally 10 eq / ton.

[0046] Further, the amount of terminal carboxyl groups in the polybutylene terephthalate resin is a value determined by dissolving 0.5 g of the polybutylene terephthalate resin in 25 mL of benzyl alcohol, and titrating using a 0.01 mol / l sodium hydroxide solution in benzyl alcohol. The method of adjusting the amount of terminal carboxyl groups should be a conventionally known method, and for example, includes a method of adjusting the polymerization conditions such as the raw material charge ratio at the time of polymerization, the polymerization temperature, or a reduced pressure method, or a method of allowing a capping agent to react.

[0047] The polybutylene terephthalate resin preferably has an intrinsic viscosity of 0.5 to 2 dl / g. From the viewpoints of moldability and mechanical properties, the intrinsic viscosity is more preferably in the range of 0.6 to 1.5 dl / g. If a resin having an intrinsic viscosity of less than 0.5 dl / g is used, the obtained resin composition tends to have low mechanical strength. In addition, if a resin having an intrinsic viscosity of more than 2 dl / g is used, the flowability and moldability of the resin composition can be deteriorated.

[0048] Further, the intrinsic viscosity of the polybutylene terephthalate resin is a value measured at 30°C in a mixed solvent containing tetrachloroethane and phenol at a mass ratio of 1:1.

[0049] The polybutylene terephthalate resin can be produced by carrying out batch or continuous melt polymerization of a dicarboxylic acid component containing terephthalic acid as a main component, or an ester derivative thereof, and a diol component containing 1,4-butanediol as a main component. Further, it is also possible to produce a low-molecular-weight polybutylene terephthalate resin by means of melt polymerization, and then carry out solid-phase polymerization under a stream of nitrogen or under reduced pressure to increase the degree of polymerization (or molecular weight) to a desired value.

[0050] The polybutylene terephthalate resin is preferably obtained using a production method including continuously melt polycondensing a dicarboxylic acid component containing terephthalic acid as a main component and a diol component containing 1,4-butanediol as a main component.

[0051] The catalyst used when the esterification reaction is carried out can be a catalyst known in the past, such as a titanium compound, a tin compound, a magnesium compound, or a calcium compound. Among them, a titanium compound is particularly preferable. Specific examples of the titanium compound used as the esterification catalyst include titanium alcoholates such as tetramethyl titanate, tetraisopropyl titanate, and tetrabutyl titanate; and titanium phenolates such as tetraphenyl titanate.

[0052] The thermoplastic resin composition of the present application contains a rubber-reinforced polystyrene-based resin (B1) and / or a polycarbonate resin (B2) as component (B).

[0053] [(B1) Rubber-reinforced polystyrene-based resin]

[0054] Rubber-reinforced polystyrene resins are obtained by blending a rubber polymer in polystyrene. Examples of the blending method include (1) a method of mechanically blending the two components, (2) a so-called graft copolymerization method in which a styrene-based monomer or the like is graft copolymerized in the presence of a rubber polymer, and (3) a so-called graft-blending method in which a general-purpose polystyrene produced using another method is blended with a graft copolymer in the above-mentioned method (2). From the viewpoint of compatibility and affinity between polystyrene and a rubber polymer, a graft copolymer obtained using the method (2) or a graft-blending product obtained using the method (3) is preferably used.

[0055] Examples of the method of producing a rubber-reinforced polystyrene resin by means of a graft copolymerization method include a method of graft polymerizing a styrene-based monomer or the like by, for example, an emulsion polymerization method, a solution polymerization method, and a suspension polymerization method, or the like in the presence of a rubber. Such a rubber-modified polystyrene resin is generally referred to as a high-impact polystyrene (HIPS).

[0056] Specific examples of the rubber polymer contained in the rubber-reinforced polystyrene resin include conjugated diene rubbers such as polybutadiene, styrene-butadiene copolymer, and hydrogenated styrene-butadiene block copolymer, and non-conjugated diene rubbers such as ethylene-propylene copolymer. Among them, polybutadiene is preferred.

[0057] Examples of the styrene-based monomer constituting the rubber-reinforced polystyrene resin include styrene, a-methylstyrene, p-methylstyrene, and bromostyrene. Among them, styrene and / or a-methylstyrene is most preferred. Examples of the monomer other than the styrene-based monomer include vinyl monomers such as acrylonitrile and methyl methacrylate.

[0058] The content of the rubber polymer component in the rubber-reinforced polystyrene resin is preferably 1 to 50 mass%, more preferably 2 to 40 mass%, and further preferably 3 to 30 mass%. Furthermore, in the case where a monomer component other than the styrene-based monomer is contained, the total content of the rubber polymer component and the styrene-based monomer component in the rubber-reinforced polystyrene resin is preferably 90 mass% or more, more preferably 95 mass% or more.

[0059] The MFR value reflecting the molecular weight of the rubber-reinforced polystyrene resin is preferably 0.5 to 15 g / 10 min, more preferably 1.0 to 10 g / 10 min, when measured at a load of 5 kg and a temperature of 200°C. If the MFR value falls outside this range, when the rubber-reinforced polystyrene resin is melt-kneaded with polybutylene terephthalate, the compatibility is insufficient, which can result in deterioration of the physical properties of the product.

[0060] The content of the rubber-reinforced polystyrene-based resin (B1) is 15 to 65 parts by mass, preferably 20 parts by mass or more, more preferably 30 parts by mass or more, further preferably 40 parts by mass or more, and preferably 60 parts by mass or less, more preferably 55 parts by mass or less, relative to 100 parts by mass of the polybutylene terephthalate resin (A). At such a mass, a resin composition having excellent dielectric properties, low warpage, and excellent appearance, strength, and rigidity can be obtained by blending with the specified amounts of the epoxy compound (D) and the glass fiber (E).

[0061] [(B2) Polycarbonate Resin]

[0062] The polycarbonate resin is an optionally branched thermoplastic polymer or copolymer obtained by reacting a dihydroxy compound, or a dihydroxy compound and a small amount of a polyhydroxy compound, with phosgene or a carbonic acid diester. The method of producing the polycarbonate resin is not particularly limited, and a conventional well-known phosgene method (interfacial polymerization method) or melt method (ester exchange method) can be used.

[0063] The dihydroxy compound raw material is preferably an aromatic dihydroxy compound substantially free of bromine atoms. Specific examples thereof are 2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A), 1,1-bis(4-hydroxyphenyl)propane, 2,2,-bis(3-methyl-4-hydroxyphenyl)propane (i.e., bisphenol C), tetramethyl bisphenol A, bis(4-hydroxyphenyl)-p-diisopropylbenzene, hydroquinone, resorcinol, and 4,4-dihydroxydiphenyl, preferably bisphenol A and bisphenol C. In addition, a compound in which one or more tetraalkyl phosphonium sulfonate is bonded to the above-described aromatic dihydroxy compound can also be used.

[0064] Among the foregoing, the polycarbonate resin is preferably an aromatic polycarbonate resin derived from 2,2-bis(4-hydroxyphenyl)propane and an aromatic polycarbonate copolymer derived from 2,2-bis(4-hydroxyphenyl)propane and another aromatic dihydroxy compound. In addition, the polycarbonate resin can also be a copolymer mainly containing an aromatic polycarbonate resin, for example, a copolymer of an aromatic polycarbonate and a polymer or oligomer having a siloxane structure. In addition, a mixture of two or more of the above-described polycarbonate resins can be used.

[0065] A monovalent aromatic hydroxy compound should be used to adjust the molecular weight of the polycarbonate resin, and examples of such compounds are m- and p-methylphenol, m- and p-propylphenol, p-tert-butylphenol, and p-long-chain-alkyl-substituted phenol compounds.

[0066] The viscosity average molecular weight (Mv) of the polycarbonate resin is preferably 15,000 or greater, particularly preferably 16,000 or greater, and most preferably 20,000 or greater. By using a polycarbonate resin having a viscosity average molecular weight of less than 15,000, the obtained resin composition tends to have lower impact resistance. Furthermore, the Mv value is preferably 40,000 or less, more preferably 35,000 or less, and further preferably 30,000 or less. If a polycarbonate resin having a viscosity average molecular weight of greater than 40,000 is used, the flowability and moldability of the resin composition can be deteriorated.

[0067] In the present application, the viscosity average molecular weight (Mv) of the polycarbonate resin is a value obtained by determining the intrinsic viscosity ([η]) from the viscosity of a methylene chloride solution of the polycarbonate resin measured at 25°C using an Ubbelohde viscometer, and then calculating the viscosity average molecular weight from the following Schott equation.

[0068] [η] = 1.23 x 10 -4 Mv 0.83

[0069] The method for producing the polycarbonate resin is not particularly limited, and a polycarbonate resin produced by a phosgene method (interfacial polymerization method) or a melt method (transesterification method) can be used. Furthermore, it is also preferable to use a polycarbonate resin obtained by subjecting a polycarbonate resin produced by a melt method to a post-treatment for adjusting the amount of terminal hydroxyl (OH) groups.

[0070] The content of the polycarbonate resin (B1) is:

[0071] (i) when used in combination with the rubber-reinforced polystyrene-based resin (B), 10 to 60 parts by mass, more preferably 40 parts by mass or less, further preferably 30 parts by mass or less, and more preferably 15 parts by mass or more, relative to 100 parts by mass of the polybutylene terephthalate resin (A), and

[0072] (ii) when not used in combination with the rubber-reinforced polystyrene-based resin (B), 10 to 70 parts by mass, preferably 20 parts by mass or less, more preferably 30 parts by mass or less, more preferably 40 parts by mass or more, and preferably 65 parts by mass or less and more preferably 55 parts by mass or less, relative to 100 parts by mass of the polybutylene terephthalate resin (A).

[0073] [(C) styrene-maleic anhydride copolymer]

[0074] The thermoplastic resin composition of the present application preferably contains a styrene-maleic anhydride copolymer (C).

[0075] The styrene-maleic anhydride copolymer is a copolymer of styrene monomers and maleic anhydride monomers, and can be produced by a known polymerization method such as emulsion polymerization, solution polymerization, suspension polymerization, or radical polymerization.

[0076] The molecular weight and the like of the styrene-maleic anhydride copolymer are not particularly limited, but the weight average molecular weight Mw thereof is preferably from 10,000 to 500,000, more preferably from 40,000 to 400,000, and further preferably from 80,000 to 350,000.

[0077] Here, the weight average molecular weight Mw is the polystyrene-conversion mass average molecular weight measured by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent.

[0078] Further, the glass transition temperature Tg of the styrene-maleic anhydride copolymer is preferably within a range of from 100 to 165°C.

[0079] The content of the maleic anhydride in the styrene-maleic anhydride copolymer is preferably selected within a range of from 1 to 20 mass%. If the amount of the maleic anhydride exceeds 20 mass%, it can excessively react with the polybutylene terephthalate resin, which can result in an increase in viscosity due to crosslinking.

[0080] The styrene-maleic anhydride copolymer can be copolymerized with other monomer components, as long as the properties of the present application are not impaired, specific examples of the other monomer components include, for example, aromatic vinyl monomers such as α-methylstyrene, vinyl cyan monomers such as acrylonitrile, unsaturated carboxylic acid alkyl ester monomers such as methyl methacrylate and methyl acrylate, and maleimide monomers such as N-methylmaleimide, N-ethylmaleimide, N-cyclohexylmaleimide, and N-phenylmaleimide, and one of these other monomer components, or two or more kinds thereof can be used.

[0081] The styrene-maleic anhydride copolymer (C) is preferably a styrene-maleic anhydride copolymer referred to as an SMA resin.

[0082] The content of the styrene-maleic anhydride copolymer (C) is preferably from 10 to 60 mass parts, more preferably 13 mass parts or more, further preferably 15 mass parts or more, and more preferably 50 mass parts or less, further preferably 40 mass parts or less, with respect to 100 mass parts of the polybutylene terephthalate resin (A). By being contained in such an amount, a resin composition having excellent dielectric properties, low warpage, and excellent appearance, strength, and rigidity can be obtained. In particular, in the case where the component (B) is a rubber-reinforced polystyrene resin (B1), it is preferable to use the styrene-maleic anhydride copolymer (C).

[0083] [(D) Epoxy Compound]

[0084] The thermoplastic resin composition of the present application contains an epoxy compound (D).

[0085] The epoxy compound should have one or more epoxy groups per molecule, and a glycidyl compound, which is a reaction product between an epichlorohydrin and an alcohol, a phenolic compound or a carboxylic acid, etc., or an epoxy compound obtained by epoxidation of an olefinic double bond, is generally used.

[0086] Examples of the epoxy compound include a novolak type epoxy compound, a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, an alicyclic epoxy compound, a glycidyl ether compound class, a glycidyl ester compound class, an epoxidized butadiene polymer, and a resorcinol type epoxy compound.

[0087] Examples of the novolak type epoxy compound include a phenol novolak type epoxy compound and a cresol novolak type epoxy compound.

[0088] Examples of the bisphenol A type epoxy compound include a bisphenol A diglycidyl ether and a hydrogenated bisphenol A diglycidyl ether, and examples of the bisphenol F type epoxy compound include a bisphenol F diglycidyl ether and a hydrogenated bisphenol F diglycidyl ether.

[0089] Examples of the alicyclic epoxy compound include a vinylcyclohexene oxide, a dicyclopentadiene oxide, a 3,4-epoxycyclohexyl-3,4-cyclohexyl carboxylate, a bis(3,4-epoxycyclohexylmethyl) adipate, a vinylcyclohexene diepoxide, and a 3,4-epoxycyclohexyl glycidyl ether.

[0090] Examples of the glycidyl ether compound include a monoglycidyl ether compound such as a methyl glycidyl ether, a butyl glycidyl ether, a 2-ethylhexyl glycidyl ether, a decyl glycidyl ether, a stearyl glycidyl ether, a phenyl glycidyl ether, a butylphenyl glycidyl ether, and an allyl glycidyl ether; and a diglycidyl ether compound such as a neopentyl glycol diglycidyl ether, an ethylene glycol diglycidyl ether, a glycerol diglycidyl ether, a propylene glycol diglycidyl ether, and a bisphenol A diglycidyl ether.

[0091] Examples of the glycidyl ester compound include a monoglycidyl ester compound such as a glycidyl benzoate and a glycidyl sorbate; and a diglycidyl ester compound such as a diglycidyl adipate, a diglycidyl terephthalate, and a diglycidyl phthalate.

[0092] Examples of the epoxidized butadiene polymer include an epoxidized polybutadiene, an epoxidized styrene-butadiene copolymer, and an epoxidized hydrogenated styrene-butadiene copolymer.

[0093] Examples of the resorcinol type epoxy compound include a resorcinol diglycidyl ether.

[0094] Further, the epoxy compound can be a copolymer including a compound containing a glycidyl ether group as one component. Examples thereof include glycidyl esters of α,β-unsaturated acids and copolymers of one or two or more kinds of monomers selected from the group consisting of α-olefins, acrylic acid, acrylic esters, methacrylic acid, and methacrylic esters.

[0095] An epoxy compound having an epoxy equivalent of 50 to 10,000 g / eq and a weight average molecular weight of 8,000 or less is preferred as the epoxy compound. If the epoxy equivalent is less than 50 g / eq, the viscosity of the resin composition increases due to the excessive amount of epoxy groups, but if the epoxy equivalent exceeds 10,000 g / eq, the amount of epoxy groups is small, meaning that it tends to be difficult to sufficiently achieve the improvement effect of the alkali resistance and hydrolysis resistance of the thermoplastic resin composition. The epoxy equivalent is more preferably 100 to 7,000 g / eq, further preferably 100 to 5,000 g / eq, and most preferably 100 to 3,000 g / eq.

[0096] Further, if the weight average molecular weight exceeds 8,000, the compatibility with the polybutylene terephthalate resin decreases and the mechanical strength of the molded body tends to deteriorate. The weight average molecular weight is more preferably 7,000 or less, further preferably 6,000 or less.

[0097] From the viewpoint of the hydrolysis resistance and appearance of the molded body, a bisphenol A type epoxy compound or a novolac type epoxy compound obtained by reacting an epichlorohydrin with bisphenol A or novolac is preferred as the epoxy compound.

[0098] The content of the epoxy compound (D) is 0.1 to 3 parts by mass, preferably 0.2 parts by mass or more, more preferably 0.3 parts by mass or more, and further preferably 0.35 parts by mass or more, relative to 100 parts by mass of the polybutylene terephthalate resin (A). Further, the content of the epoxy compound (D) is preferably 2.5 parts by mass or less, more preferably 2 parts by mass or less, further preferably 1.5 parts by mass or less, and particularly preferably 1 part by mass or less. By mixing the epoxy compound in such an amount, the molecular weight and the mechanical strength and the like can be reduced by the hydrolysis of the polybutylene terephthalate, and by blending the specified amounts of the rubber reinforced polystyrene resin (B1), the polycarbonate resin (B2), and the glass fiber (E), a resin composition that exhibits excellent dielectric properties, low warpage, and excellent appearance, strength, and rigidity can be obtained. If the content of the epoxy compound is less than 0.1 parts by mass, the alkali resistance and the hydrolysis resistance tend to deteriorate, and if the content of the epoxy compound exceeds 3 parts by mass, crosslinking tends to occur and the flowability at the time of molding tends to deteriorate.

[0099] Further, the equivalent ratio of the epoxy group in the epoxy compound (D) to the terminal COOH group in the polybutylene terephthalate resin (A) (epoxy group / COOH group) is preferably within a range of 0.2 to 2.7. If the equivalent ratio is lower than 0.2, the hydrolysis resistance tends to be deteriorated, and if the equivalent ratio exceeds 2.7, the moldability tends to become unstable. The epoxy group / COOH group ratio is more preferably 0.3 to 2.5.

[0100] [(E) Glass fiber]

[0101] The polycarbonate resin composition of the present application contains a glass fiber (E).

[0102] If a glass fiber generally used for a thermoplastic polyester resin is used as the glass fiber, an A glass, an E glass, or an alkali-resistant glass composition containing a zirconia component, etc. can be used, but from the viewpoint of improving the heat stability of the resin composition, an alkali-free glass (E glass) is preferred.

[0103] Further, regardless of the form of the glass fiber at the time of blending, such as a chopped strand, a roving glass, or a master batch of a thermoplastic resin and a glass fiber, any type of publicly known glass fiber can be used, but generally, it is preferred to use a product obtained by bundling a large number of these fibers as a chopped strand glass fiber (chopped glass fiber) cut to a specified length by shearing.

[0104] The average fiber diameter of the glass fiber is preferably 3 to 20 μm, more preferably 5 μm or more, further preferably 7 μm or more, and more preferably 18 μm or less, further preferably 15 μm or less. Further, the fiber length is preferably 0.3 to 10 mm, more preferably 0.5 mm or more, further preferably 1 mm or more, and more preferably 8 mm or less, further preferably 5 mm or less.

[0105] The glass fiber can be treated with a bundling agent or a surface treatment agent. In addition to an untreated glass fiber, the glass fiber can be surface-treated by adding a bundling agent or a surface treatment agent at the time of manufacturing the resin composition of the present application.

[0106] Examples of the bundling agent and the surface treatment agent include emulsions of resins such as a vinyl acetate resin, an ethylene / vinyl acetate copolymer, an acrylic resin, an epoxy resin, a polyurethane resin, and a polyester resin.

[0107] Other examples include epoxy resins such as novolac-type epoxy resins, epoxy-based compounds such as bisphenol A-type epoxy resins, aminosilane-based compounds such as γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and γ-(2-aminoethyl)aminopropyltrimethoxysilane, chlorosilane-based compounds such as vinyltrichlorosilane and methylvinyl dichlorosilane, alkoxy silane-based compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, and γ-ethylacryloxypropyltrimethoxysilane, epoxysilane-based compounds such as β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and γ- glycidoxypropyltrimethoxysilane, acrylic-based compounds, isocyanate-based compounds, and titanate-based compounds.

[0108] Among these clustering agents and surface treatment agents, novolac-type epoxy resins and bisphenol A-type epoxy resins are preferred, and novolac-type epoxy resins are particularly preferred.

[0109] Combinations of two or more of these clustering agents and surface treatment agents can be used, and the amount of use (adhesion amount) is generally 10 mass% or less and preferably 0.05 to 5 mass% with respect to the mass of the glass fiber. Setting the adhesion amount to 10 mass% or less achieves an essential and sufficient effect, and is thus economically advantageous.

[0110] Two or more kinds of glass fibers can be used in combination according to the desired properties.

[0111] The content of the glass fiber (E) is 30 to 150 parts by mass, preferably 40 parts by mass or more, more preferably 50 parts by mass or more, and preferably 120 parts by mass or less, more preferably 100 parts by mass or less, with respect to 100 parts by mass of the polybutylene terephthalate resin (A). By mixing the glass fiber in such an amount, the strength and heat resistance of the obtained molded body can be improved and the beneficial effect of reducing shrinkage is enhanced, and if the content exceeds 150 parts by mass, the impact resistance and flowability are insufficient, the surface appearance of the molded body tends to deteriorate, and stable production is difficult. If the content is less than 30 parts by mass, the beneficial effect of improving the strength, rigidity, and the like is reduced. However, in the case where the amount of addition of the glass fiber is less than 30 parts by mass, there can be some applications and use examples in which such use is possible if the dielectric constant, appearance, and weld strength are good due to product design and use environment. In the case corresponding to such examples, the content of the glass fiber is preferably 25 parts by mass or more.

[0112] [Other inorganic fillers]

[0113] In addition to the above glass fiber, the thermoplastic resin composition of the present application preferably contains other plate-like, particulate, or amorphous inorganic fillers. The plate-like inorganic fillers exhibit the effect of reducing anisotropy and warping, and examples thereof include talc, glass flake, mica, kaolin, and metal foil. Among these plate-like inorganic fillers, glass flake is preferred.

[0114] Examples of other types of particulate and amorphous inorganic fillers include ceramic beads, clay, zeolite, barium sulfate, titanium oxide, silicon oxide, aluminum oxide, magnesium hydroxide, and zinc sulfide.

[0115] Talc, titanium oxide, and zinc sulfate are particularly preferred as the other inorganic fillers.

[0116] In the case of containing the other inorganic fillers, the content of the other inorganic fillers is preferably 0.1 to 30 parts by mass, more preferably 0.5 parts by mass or more, further preferably 1 part by mass or more, and more preferably 20 parts by mass or less, relative to 100 parts by mass of the polybutylene terephthalate resin (A).

[0117] [Laser light absorber]

[0118] The molded body formed from the thermoplastic resin composition of the present application is preferably laser-welded with a mating material.

[0119] The laser welding method is not particularly limited, and a conventional method can be used. For example, a single molded product is preferably obtained by using the obtained welding molded body as an absorbing side (absorbing side member), bringing the absorbing side member into contact with a resin molded body (transmitting side member) as a mating material, irradiating laser light so that the two molded bodies are welded and integrated. A single molded product can be obtained by bringing the welding portion of the welding molded body (absorbing side member containing a laser light absorber) obtained by injection molding into surface contact or butt contact with the transmitting side member of the mating side that transmits laser light, and irradiating laser light from the side of the transmitting side member that exhibits high transmittance, so that the interface between the two members is at least partially melted, and then the two members are integrated by cooling.

[0120] The absorbing side member containing a laser light absorber is a member that contains a thermoplastic resin composition that can absorb laser light and is melted due to the absorption of laser light, and specific examples thereof include a member containing a thermoplastic resin containing an absorber such as carbon black or a laser light-absorbing dye to be able to absorb laser light.

[0121] The content of the absorber such as carbon black is not particularly limited, but is preferably, for example, 0.2 to 1% by mass relative to the resin composition.

[0122] Preferred examples of laser light transmittable dyes which can be used for the laser light transmittable side member include nigrosine, aniline black, phthalocyanine, naphthalocyanine, porphyrin, perylene, quaterrylene, azo dye, anthraquinone, squarine derivative, and immonium compound.

[0123] The content of the laser light transmittable dye is preferably 0.001 to 5 parts by mass, more preferably 0.003 to 3 parts by mass, further preferably 0.005 to 2 parts by mass, relative to 100 parts by mass of the resin component.

[0124] In order to achieve higher weld strength, it is preferable that both the absorbing side member and the transmittable side member are the polybutylene terephthalate resin composition of the present application, and that the absorbing side member contains an absorber such as carbon black or laser light-absorbing dye, and the transmittable side member does not contain a coloring material or contains a coloring material which transmits laser light.

[0125] The absorbing side member and the transmittable side member are not limited to be the same resin composition as long as the weld strength and the air tightness are satisfied, and a resin composition different from the resin composition of the present application can be used in the transmittable side member from the viewpoints of, for example, appearance and low warpage.

[0126] [Stabilizer]

[0127] The thermoplastic resin composition of the present application preferably contains a stabilizer from the viewpoints of improving heat stability and preventing deterioration of mechanical strength, transparency, and hue. A phosphorus-based stabilizer, a sulfur-based stabilizer, and a phenol-based stabilizer are preferable as the stabilizer.

[0128] Examples of the phosphorus-based stabilizer include phosphorous acid, phosphoric acid, esters of phosphorous acid (phosphite ester), trivalent phosphoric acid ester (phosphonite), and pentavalent phosphoric acid ester (phosphate ester), of which, organic phosphite ester, organic phosphonite ester, and organic phosphate ester are preferable.

[0129] A preferable organic phosphate ester compound is a compound represented by the following general formula:

[0130] (R 1 O) 3-n P(=O)OH n

[0131] (in the formula, R 1 represents an alkyl group or an aryl group, and R 1 groups can be the same as or different from each other. n represents an integer of 0 to 2.)

[0132] A more preferable organic phosphate ester compound is a compound in which R 1Long-chain alkyl acid phosphate compounds having 8 to 30 carbon atoms. Specific examples of alkyl groups having 8 to 30 carbon atoms include octyl, 2-ethylhexyl, isooctyl, nonyl, isononyl, decyl, isodecyl, dodecyl, tridecyl, isotridecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, and triacontyl.

[0133] Examples of long-chain alkyl acid phosphates include octyl acid phosphate, 2-ethylhexyl acid phosphate, decyl acid phosphate, lauryl acid phosphate, octadecyl acid phosphate, oleyl acid phosphate, behenyl acid phosphate, phenyl acid phosphate, nonylphenyl acid phosphate, cyclohexyl acid phosphate, phenoxyethyl acid phosphate, alkoxypolyethylene glycol acid phosphate, bisphenol A acid phosphate, dimethyl acid phosphate, diethyl acid phosphate, dipropyl acid phosphate, diisopropyl acid phosphate, dibutyl acid phosphate, dioctyl acid phosphate, di-2-ethylhexyl acid phosphate, dioctadecyl acid phosphate, dilauryl acid phosphate, distearyl acid phosphate, diphenyl acid phosphate, and bisnonylphenyl acid phosphate. Of these, octadecyl acid phosphate is preferred, and this compound is commercially available under the trade name "Adeka Stab AX-71" manufactured by ADEKA.

[0134] The preferred organic phosphite compound is a compound represented by the following general formula:

[0135] R 2 O-P(OR 3 )(OR 4 )

[0136] (in the formula, R 2 , R 3 , and R 4 each is a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or an aryl group having 6 to 30 carbon atoms, and at least one of R 2 , R 3 , and R 4 is an aryl group having 6 to 30 carbon atoms.)

[0137] Examples of the organic phosphite compound include triphenyl phosphite, tris(nonylphenyl) phosphite, dilauryl hydrogen phosphite, triethyl phosphite, tridecyl phosphite, tris(2- ethylhexyl) phosphite, tris(tridecyl) phosphite, tristearyl phosphite, diphenyl monodecyl phosphite, monophenyl didecyl phosphite, diphenyl monotridecyl phosphite, tetraphenyl dipyrogyl phosphite, tetraphenyl tetra(tridecyl) pentaerythritol phosphite, hydrogenated bisphenol A phenol phosphite polymer, diphenyl hydrogen phosphite, 4,4'-butylidenebis(3-methyl-6-tert-butylphenyl di(tridecyl) phosphite, tetra(tridecyl) 4,4'-isopropylidene diphenyl diphosphite, bis(tridecyl) pentaerythritol diphosphite, bis(nonylphenyl) pentaerythritol diphosphite, dilauryl pentaerythritol diphosphite, di-stearyl pentaerythritol diphosphite, tris(4-tert-butylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, hydrogenated bisphenol A pentaerythritol phosphite polymer, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, 2,2'-methylenebis(4,6-di-tert-butylphenyl) octyl phosphite, and bis(2,4-dicumylphenyl) pentaerythritol diphosphite. Among them, bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite is preferred.

[0138] The preferred organic phosphonite compound is a compound represented by the following general formula:

[0139] R 5 -P(OR 6 )(OR 7 )

[0140] (in the formula, R 5 , R 6 , and R 7 each is a hydrogen atom, an alkyl group having a carbon number of 1 to 30, or an aryl group having a carbon number of 6 to 30, and at least one of R 5 , R 6 , and R 7 is an aryl group having a carbon number of 6 to 30.)

[0141] Further, examples of the organic phosphite compound include tetrakis(2,4-di-iso-propylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,4-di-n-butylphenyl)-4,4'- biphenylenediphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,4'- biphenylenediphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,3'- biphenylenediphosphonite, tetrakis(2,4-di-tert-butylphenyl)-3,3'- biphenylenediphosphonite, tetrakis(2,6-di-iso-propylphenyl)-4,4'- biphenylenediphosphonite, tetrakis(2,6-di-n-butylphenyl)-4,4'- biphenylenediphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,4'- biphenylenediphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,3'- biphenylenediphosphonite, and tetrakis(2,6-di-tert-butylphenyl)-3,3'- biphenylenediphosphonite.

[0142] Any conventionally known compound containing a sulfur atom can be used as the sulfur-based stabilizer, and among them, a sulfide compound is preferred. Specific examples thereof include dilaurylthiodipropionate, ditetradecylthiodipropionate, distearylthiodipropionate, pentaerythritol tetrakis(3-dodecylthiopropionate), thio-bis(N-phenyl-β-naphthylamine), 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, tetramethyl thiuram monosulfide, tetramethyl thiuram disulfide, nickel dibutyldithiocarbamate, nickel isopropyl xanthate, and trilauryl trithiophosphite. Among them, pentaerythritol tetrakis(3-dodecylthiopropionate) is preferred.

[0143] Preferred examples of the phenol-based stabilizer are hindered phenol-based stabilizers, examples of which 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), and pentaerythritol tetrakis(3-(3,5-dineopentyl-4-hydroxyphenyl)propionate). 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.

[0144] Specific examples of such hindered phenol-based stabilizers include the products "Irganox 1010" and "Irganox 1076" manufactured by BASF and the products "Adekastab AO-50" and "Adekastab AO-60" manufactured by ADEKA.

[0145] One stabilizer can be mixed in or two or more stabilizers can be mixed in in any combination and in any ratio.

[0146] In the present application, from the viewpoints of the residence characteristics, heat resistance, laser light transmittance, and laser welding properties, it is preferable to use a combination of the phosphorus-based stabilizer represented by the above general formula (1), particularly a long-chain alkyl acid phosphoric acid ester, and a hindered phenol-based stabilizer.

[0147] The content of the stabilizer is preferably 0.001 to 2 parts by mass with respect to 100 parts by mass of the polybutylene terephthalate resin (A). If the content of the stabilizer is less than 0.001 parts by mass, it is almost difficult to expect improvement in the heat stability and the compatibility of the resin composition, and molecular weight reduction and color tone deterioration are likely to occur when the molding composition is molded, and if the content of the stabilizer exceeds 2 parts by mass, the amount becomes excessive, and silvering and color tone deterioration are likely to occur. The content of the stabilizer is more preferably 0.01 to 1.5 parts by mass, and further preferably 0.1 to 1 part by mass.

[0148] [Release agent]

[0149] The thermoplastic resin composition of the present application preferably contains a release agent. A known release agent commonly used for polyester resins can be used as the release agent, but among them, from the viewpoint of achieving good alkali resistance, it is preferable to use a polyolefin-based compound and a fatty acid ester-based compound.

[0150] The polyolefin-based compound includes a compound selected from the group consisting of paraffin wax and polyethylene wax, and among them, a compound having a weight average molecular weight of 700 to 10,000, particularly 900 to 8,000 is preferable.

[0151] Examples of the fatty acid ester-based compound include, for example, esters of a saturated or unsaturated monovalent or divalent aliphatic carboxylic acid, fatty acid glycerol esters, and fatty acid sorbitan esters, and the like, and partial saponification products thereof. Among them, fatty acid monoesters and fatty acid diesters composed of a fatty acid having a carbon number of 11 to 28, preferably 17 to 21, and an alcohol are preferable.

[0152] Examples of the fatty acid include palmitic acid, stearic acid, hexanoic acid, decanoic acid, lauric acid, arachidic acid, behenic acid, wood tar acid, cerotic acid, melissic acid, tetratriacontanoic acid, montanic acid, adipic acid, and azelaic acid. In addition, the fatty acid can be alicyclic.

[0153] Saturated or unsaturated mono- or polyhydric alcohols can be used as the alcohol. These alcohols can have substituents such as fluorine atoms or aryl groups. Among them, saturated mono- or polyhydric alcohols having a carbon number of 30 or less are preferred, and aliphatic saturated mono- and polyhydric alcohols having a carbon number of 30 or less are more preferred. Here, aliphatic compounds also include alicyclic compounds.

[0154] Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerol, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentyl glycol, di(trimethylolpropane), and dipentaerythritol.

[0155] Furthermore, the above-mentioned ester compounds can contain aliphatic carboxylic acids and / or alcohols as impurities, and can be a mixture of a plurality of compounds.

[0156] Specific examples of aliphatic ester compounds include glyceryl monostearate, glyceryl monobehenate, glyceryl dibehenate, 12-hydroxy glyceryl monostearate, sorbitan monobehenate, pentaerythritol monostearate, pentaerythritol distearate, stearyl stearate, and ethylene glycol montanic acid ester.

[0157] The content of the release agent is preferably 0.1 to 3 parts by mass, more preferably 0.2 to 2.5 parts by mass, and further preferably 0.3 to 2 parts by mass, relative to 100 parts by mass of the polybutylene terephthalate resin (A). If the content is less than 0.1 parts by mass, the surface properties tend to deteriorate due to release defects at the time of melt molding, but if the content exceeds 3 parts by mass, the kneadability of the resin composition tends to deteriorate and the surface of the molded body tends to become foggy.

[0158] [Carbon black]

[0159] The thermoplastic resin composition of the present application preferably contains carbon black.

[0160] There is no particular limitation on the type, raw material, or manufacturing method of the carbon black, and furnace carbon black, tank carbon black, acetylene black, or Ketjen black, etc. can be used. There is no particular limitation on the number average particle diameter of the carbon black, but it is preferably about 5 to 60 nm.

[0161] Preferably, the carbon black is blended with the thermoplastic resin, preferably the polybutylene terephthalate resin, and it is particularly preferable to be mixed with the polybutylene terephthalate resin in advance as a master batch.

[0162] The content of the carbon black is preferably 0.1 to 4 parts by mass, and more preferably 0.2 to 3 parts by mass, relative to 100 parts by mass of the polybutylene terephthalate resin (A). If the content is less than 0.1 parts by mass, the desired color cannot be achieved and the weather resistance improvement effect is insufficient, and if the content exceeds 4 parts by mass, the mechanical properties tend to deteriorate.

[0163] [Other components]

[0164] The thermoplastic resin composition of the present application can contain other thermoplastic resins in addition to the above-mentioned components (A) to (C), provided that the advantageous effects of the present application are not impaired. Specific examples of the other thermoplastic resins include polyethylene terephthalate resins, polyacetal resins, polyamide resins, polyphenylene ether resins, polyphenylene sulfide resins, polysulfone resins, polyether sulfone resins, polyether imide resins, polyether ketone resins, and polyolefin resins.

[0165] However, in the case of containing other types of resins, the content thereof is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, further preferably 5 parts by mass or less, and particularly preferably 3 parts by mass or less, relative to 100 parts by mass of the polybutylene terephthalate resin (A).

[0166] Furthermore, the thermoplastic resin composition of the present application can contain various additives other than those mentioned above, examples of such additives including flame retardants, auxiliary flame retardants, anti-dripping agents, ultraviolet absorbers, static electricity suppressors, anti-fogging agents, anti-blocking agents, plasticizers, dispersants, antibacterial agents, and coloring agents, dyes, and pigments other than carbon black.

[0167] [Manufacture of thermoplastic resin composition]

[0168] The thermoplastic resin composition of the present application is manufactured by feeding the above-mentioned essential components and other components as needed to an extruder, melt-kneading to obtain a kneaded product, and extruding the kneaded product. The kneaded product is preferably extruded to form a pellet-like resin composition.

[0169] The following method can be given as an example of a particularly preferred method of manufacturing the thermoplastic resin composition of the present application.

[0170] That is, the thermoplastic resin composition is manufactured by the following method: using a twin-screw kneading extruder as the extruder, feeding at least the polybutylene terephthalate resin (A), the rubber-reinforced polystyrene-based resin (Bl), the polycarbonate resin (B2), and the styrene-maleic anhydride copolymer (C) to the base portion (main feed port) of the twin-screw kneading extruder, feeding the glass fiber (E) laterally, and kneading at a screw-kneading temperature of 200°C or lower.

[0171] The twin-screw kneading extruder has a barrel and two screws inside the barrel, and the barrel has a main feed port and a lateral feed port on the downstream side in the extrusion direction from the main feed port. The barrel is preferably provided with a degassing portion at one or more positions.

[0172] The resin components (A) to (C) are fed from a main feed port located at the base of the extruder, and the glass fiber (E) is fed from a side feed port of the extruder. The epoxy compound (D) can be fed from the main feed port, but can also be fed from the side feed port where the glass fiber is fed or from a separately provided side feed port.

[0173] The resin components fed from the main feed port can be plasticized in the first kneading section, and the glass fiber (E) is screw-kneaded with the plasticized resin composition, but the temperature during this screw-kneading is, for example, 200°C or lower, which is a temperature lower than that conventionally used. By setting the temperature when the glass fiber is screw-kneaded to 200°C or lower, the melt viscosity of the components (B) and (C) having a low melting point (or Tg value) can be maintained at a higher melt viscosity than usual, increasing the shear force for opening the glass fiber, so that the glass fiber is sufficiently opened and uniformly dispersed in the resin composition. Unopened glass fibers that are aggregated while not being sufficiently opened have a high dielectric constant, which leads to an increase in dielectric constant deviation in a molded body in which these unopened glass fibers remain and are not uniformly dispersed, meaning that the rigidity of the molded body tends to be insufficient, and the performance required for a millimeter wave radar member cannot be stably achieved.

[0174] The temperature when the glass fiber is screw-kneaded is preferably 280°C or lower, more preferably 195°C or lower, further preferably 190°C or lower, and is preferably 170°C or higher, more preferably 175°C or higher, further preferably 180°C or higher.

[0175] [Molded body]

[0176] The manufacturing method for the molded body using the thermoplastic resin composition of the present application is not particularly limited, and any molding method conventionally used for thermoplastic resin compositions can be employed. Examples thereof include an injection molding method, an ultra-high-speed injection molding method, an injection compression molding method, a two-color molding method, a hollow molding method such as a gas-assisted molding method, a molding method using an insulated mold, a molding method using a rapid heating mold, a foam molding (including supercritical fluid), an insert molding, an IMC (in-mold coating) molding method, an extrusion molding method, a sheet molding method, a thermoforming method, a rotational molding method, a laminate molding method, a press molding method, and a blow molding method, etc. Among these, an injection molding method is preferred from the viewpoint that the advantageous effects of the present application are remarkable in terms of productivity and, for example, good surface properties of the obtained molded body, etc.

[0177] The molded body of the thermoplastic resin composition of the present application preferably has a relative dielectric constant of 3.50 or less, more preferably 3.45 or less, further preferably 3.40 or less, particularly preferably 3.35 or less. In addition, the molded body preferably has a dielectric loss tangent of 0.013 or less. The relative dielectric constant and the dielectric loss tangent are values at a frequency of 70 to 90 GHz. Here, the molded body preferably has a thickness of 1 to 5 mm, and the relative dielectric constant and / or the dielectric loss tangent is preferably the above-mentioned value in the thickness range.

[0178] In addition, the molded body obtained by molding the thermoplastic resin composition of the present application has a small variation in relative dielectric constant, and the difference between the maximum and minimum values of the relative dielectric constant of at least 10 molded bodies is preferably 0.07 or less, and particularly preferably 0.05 or less.

[0179] The molded body obtained from the thermoplastic resin composition of the present application preferably has a relative dielectric constant of 3.50 or less, and particularly preferably 3.45 or less at a frequency of 70 to 90 GHz. In addition, the molded body preferably has a dielectric loss tangent of 0.013 or less, and particularly preferably 0.012 or less at a frequency of 70 to 90 GHz.

[0180] The obtained molded body has a low relative dielectric constant, a small variation in relative dielectric constant among the obtained molded bodies, exhibits low warpage and excellent appearance, exhibits excellent strength and rigidity, exhibits high transmittance and excellent laser welding properties, and the molded product obtained by laser welding to a resin molded product as a mating material exhibits excellent welding strength, and thus can be advantageously used as a millimeter wave radar member. The millimeter wave radar member includes a housing for housing or protecting an antenna module for transmitting or receiving millimeter waves, a radome (radar antenna cover), and a member installed in a path from a millimeter wave radar module including these to an object detected by millimeter waves (in the case where the millimeter wave radar member is used for an automobile sensor, this includes a cover, an automobile exterior member, or a commercial emblem, etc. disposed in a path of millimeter waves transmitted or received from the millimeter wave radar member).

[0181] The millimeter wave radar member can be obtained by irradiating a molded body formed of the thermoplastic resin composition of the present application (the molded body is preferably provided as a transmissive member) and a resin molded product as a mating material in surface contact or butt contact with the molded body with laser light so that the interface between the two members is at least partially melted, and then cooled to weld the two members and integrate.

[0182] From the viewpoint of easily achieving laser weldability and high welding strength, the resin molded product of the mating member is preferably a molded product containing a polybutylene terephthalate resin compound, and particularly preferably a molded product obtained by molding the thermoplastic resin composition of the present application.

[0183] Specific preferred examples of the millimeter wave radar include a vehicle-mounted millimeter wave radar for automatic brake control equipment, inter-vehicle distance control equipment, pedestrian accident reduction steering equipment, false alarm suppression control equipment, acceleration suppression equipment at the time of misfooting, approaching vehicle alarm equipment, lane keeping assistance equipment, rear-end collision prevention alarm equipment, parking assistance equipment, and vehicle surrounding obstacle alarm equipment; a millimeter wave radar for railway / airborne use for platform monitoring / railway crossing obstacle detection equipment, in-vehicle information (content) transmission equipment, tram / railway collision prevention equipment, and runway obstacle detection equipment; a millimeter wave radar for traffic infrastructure, such as intersection monitoring equipment and elevator monitoring equipment; a millimeter wave radar for security equipment; a millimeter wave radar for medical / care use, such as a system for protecting children and the elderly; and a millimeter wave radar for transmission of information content.

[0184] Embodiments

[0185] The present application will be described more specifically below using examples. However, it should be understood that the present application is not limited to the examples given below.

[0186] The components used in the following examples and comparative examples are shown in Table 1 and Table 3 below.

[0187] [Table 1]

[0188]

[0189]

[0190] (Examples 1 to 3 and Comparative Example 1)

[0191] Pellets of the thermoplastic resin composition were obtained by uniformly mixing the components shown in Table 1 above, except for the glass fiber, in the proportions (parts by mass) shown in Table 2 below using a tumbler mixer, feeding the mixture obtained from the main feed port of a twin-screw kneading extruder (TEX30α manufactured by Japan Steel Works, L / D = 42) at a cylinder temperature of the first kneading section of 270°C, plasticizing, feeding the glass fiber from the side feed port at the proportions shown in Table 2, setting the cylinder temperature to 270°C after the addition of the glass fiber, melt-kneading at a discharge rate of 40 kg / h and a screw rotation speed of 200 rpm, extruding the kneaded product obtained, rapidly cooling in a water bath, and then forming pellets using a pelletizer. Kneading was performed under the above conditions, with a screw kneading temperature of 278°C, except in Example 2.

[0192] In Example 2, the cylinder temperature was set to 180°C after the addition of the glass fiber, and kneading was performed in the same manner as in Example 1, except for the change in the cylinder temperature, with a kneading temperature of 186°C.

[0193] [Breaking tensile strength and tensile modulus]

[0194] The pellets thus obtained were dried at 120°C for 5 hours, and then injection-molded into ISO multi-purpose test pieces (thickness 4 mm) using an injection molding machine (mold clamping force 85T) manufactured by Japan Steel Works at a cylinder temperature of 250°C and a mold temperature of 80°C.

[0195] The breaking tensile strength (unit: MPa) and the tensile modulus (unit: MPa) were measured using ISO multi-purpose test pieces (thickness 4 mm) according to ISO 527.

[0196] [Hydrolysis resistance: tensile strength retention rate after 100 hours of treatment]

[0197] The pellets thus obtained were dried at 120°C for 5 hours using a hot air dryer, and then injection-molded into ISO multi-purpose test pieces (thickness 4 mm) using an injection molding machine ("NEX80" manufactured by Nissei Plastic Industrial Co.) at a cylinder temperature of 250°C and a mold temperature of 80°C.

[0198] The tensile strength (before treatment) (unit: MPa) was measured using ISO multi-purpose test pieces according to ISO 527 at a tensile speed of 5 mm / min.

[0199] Further, the ISO multi-purpose test pieces were treated at a temperature of 121°C, a relative humidity of 100%, and a pressure of 2 atm for 100 hours using a pressure cooker tester (PCT) (manufactured by Hirayama Manufacturing Corporation), and then the tensile strength was measured in the same manner, the strength retention rate (unit: %) was calculated from the strength after processing with respect to the strength before processing, and the hydrolysis resistance was evaluated.

[0200] [Warpage amount and evaluation of low warpage]

[0201] A disc having a diameter of 100 mm and a thickness of 1.6 mm was molded using a side gate mold in an injection molding machine (NEX80-9E manufactured by Nissei Plastic Industrial Co.) at a cylinder temperature of 260°C and a mold temperature of 80°C, and the warpage amount of the disc (unit: mm) was determined.

[0202] The low warpage was evaluated and rated using the following evaluation criteria.

[0203] A: Warpage amount was less than 1 mm

[0204] B: warpage amount is 1 mm or more but less than 3 mm

[0205] C: warpage amount is 3 mm or more

[0206] [evaluation of surface appearance]

[0207] A flat plate having a length of 100 mm, a width of 100 mm, and a thickness of 3 mm was molded using a NEX80-9E injection molding machine manufactured by Nissei Plastic Industrial Co., at a cylinder temperature of 250°C and a mold temperature of 80°C, and the surface appearance of the flat plate was visually observed and classified as follows.

[0208] A: good

[0209] B: slightly poor

[0210] C: extremely poor

[0211] [relative dielectric constant and dielectric loss tangent]

[0212] Ten flat plate-shaped molded bodies each having a length of 100 mm, a width of 100 mm, and a thickness of about 2 mm were molded using a NEX80-9E injection molding machine manufactured by Nissei Plastic Industrial Co., at a cylinder temperature of 250°C and a mold temperature of 80°C, after drying the pellets obtained using the above method at 120°C for 5 hours.

[0213] The molded bodies obtained by this method were placed on a sample stage having a diameter Φ of 80 mm, and using a WR10-VNAX millimeter wave module manufactured by Virginia Diodes and a DPS10 millimeter wave / microwave measurement equipment system equipped with a N5227A network analyzer manufactured by KEYSIGHT and a through-attenuation measurement tool equipped with a dielectric lens manufactured by Keycom Corporation, the amount of through-attenuation and the phase change were measured at a measurement frequency of 70 to 90 GHz at 25°C using a free space frequency change method. Furthermore, the precise thickness of the molded bodies was measured using a digital micrometer manufactured by Shinwa Rules Co., and the relative dielectric constant and the dielectric loss tangent were determined based on the amount of through-attenuation, the phase change, and the thickness measurement results.

[0214] The difference between the maximum value and the minimum value was determined from the relative dielectric constants of the ten molded bodies.

[0215] [comprehensive evaluation]

[0216] Based on the above results, a comprehensive evaluation was performed using the following evaluation criteria 1 to 3.

[0217] 1. Tensile strength of 120 MPa or more, hydrolysis resistance of 60% or more, evaluation of disc warping and appearance of A, relative dielectric constant of 3.40 or less, and difference between maximum and minimum values of dielectric constant of 0.07 or less.

[0218] 2. Tensile strength of 120 MPa or more, hydrolysis resistance of 50 to 60%, evaluation of disc warping and appearance of A or B, relative dielectric constant of 3.40 or less, and difference between maximum and minimum values of dielectric constant of 10 molded bodies of 0.05 or less.

[0219] 3. Any of the following: tensile strength of 120 MPa or more, hydrolysis resistance of 50% or more and less than 60%, evaluation of disc warping and appearance of A or B, and relative dielectric constant of 3.40 or less.

[0220] The structures of these evaluations are shown in Table 2 below.

[0221] [Table 2]

[0222]

[0223] (Examples 4 to 7 and Comparative Example 2)

[0224] [Table 3]

[0225]

[0226] Pellets of the thermoplastic resin composition were obtained by uniformly mixing the other components shown in Table 3 above except for the glass fiber using a tumbler mixer, at the proportions (mass parts) shown in Table 4 below, feeding the mixture obtained from the main feed port of a twin-screw kneading extruder (TEX30α manufactured by Japan Steel Works, L / D = 42) at a cylinder temperature of the first kneading section of 270°C, plasticizing, feeding the glass fiber from the side feed port at the proportions shown in Table 4, setting the cylinder temperature to 220°C after the addition of the glass fiber, and melt-kneading at a discharge rate of 40 kg / h and a screw rotation speed of 200 rpm, extruding the kneaded product obtained, rapidly cooling in a water bath, then forming pellets using a pelletizer, and evaluating the pellets in the same manner as in Example 1, and the following evaluations were performed.

[0227] [Transmittance (%)]

[0228] The resin composition pellets thus obtained were dried at 120°C for 5 hours, and then the pellets were molded into a flat plate of 60 mm x 60 mm x 1.5 mm using an injection molding machine (NEX80-9E manufactured by Nissei Plastic Industrial Co.) at a cylinder temperature of 260°C and a mold temperature of 80°C.

[0229] The transmittance of light having a wavelength of 1,070 nm (unit: %) was measured using a UV-visible-near infrared spectrophotometer (UV-3100PC manufactured by Shimadzu Corporation).

[0230] [Laser Welding Strength (unit: N)]

[0231] The laser welding strength measurement was performed by preparing the circular plate-shaped transmittance-side member 1 and the cylindrical absorption-side member 2 shown in Table 1, overlapping the two members, laser welding to obtain a laser-welded member, and then measuring the welding strength thereof. Figure 1

[0232] (1) Preparation of Test Piece for Transmittance-Side Member

[0233] After the pellets obtained in the above-described examples and comparative examples were dried at 120°C for 5 hours, a test piece for a transmittance-side member in the shape of a circular plate (diameter 48 mm, thickness 1.5 mm) as shown in Table 1 was injection-molded using an injection molding machine (J55 manufactured by Japan Steel Works) at a cylinder temperature of 260°C, a mold temperature of 60°C, an injection speed of 60 mm / s, a holding pressure of 70 MPa, a holding time of 5 s, and a cooling time of 15 s. Figure 1

[0234] (2) Preparation of Test Piece for Absorption-Side Member

[0235] A test piece for an absorption-side member was prepared in the same manner as in the above-described manufacturing method by mixing 100 parts by mass of a polybutylene terephthalate resin (Novaduran 5008 described above), 1.5 parts by mass of a cresol novolak-type epoxy compound (YDCN704 described above), 0.3 parts by mass of a stabilizer (AO-60 manufactured by ADEKA), 0.7 parts by mass of a mold release agent (Unistar H476D manufactured by NOF Corp.), 2 parts by mass of a carbon black master batch as a colorant, and 44 parts by mass of a reinforcing filler (T-127 described above). The test piece for an absorption-side member was injection-molded under the same molding conditions as those described in the above-described (1). Figure 1 ​​A test piece for the absorption-side member shown in Fig. 1 was prepared in the same manner as in Example 1, except that the absorption-side member 2 was a cylindrical member (diameter 48 mm, height 20 mm, and having a protrusion 2 mm high and 2 mm wide with respect to the entire height (5 mm) of the joint surface 3).

[0236] (3) Laser Weldability

[0237] For laser welding, a welded member was prepared by the following: the pressing force per unit area was 2.5 N / mm2, the test piece for the absorption-side member 2 was overlaid on the test piece for the transmission-side member 1, and a laser beam X was scanned on the welding predetermined line 4 on the test piece for the transmission-side member 1 using a Fine Device Co. manufactured electric scanning type laser device (laser wavelength: 1,070 nm, laser spot diameter: 2.0 mm) at an output of 150 W and a speed of 900 mm / s, and the scan circuit was changed. 2 The pressing force per unit area was 2.5 N / mm2, the test piece for the absorption-side member 2 was overlaid on the test piece for the transmission-side member 1, and a laser beam X was scanned on the welding predetermined line 4 on the test piece for the transmission-side member 1 using a Fine Device Co. manufactured electric scanning type laser device (laser wavelength: 1,070 nm, laser spot diameter: 2.0 mm) at an output of 150 W and a speed of 900 mm / s, and the scan circuit was changed. :2.0mm), at an output of 150 W and a speed of 900 mm / s, on the welding predetermined line 4 on the test piece for the transmission-side member 1, and the scan circuit was changed.

[0238] The resulting welded member was then evaluated using a tensile strength tester (1t Tensilon manufactured by Orientec Co., Ltd.) by the following: a pull rod was attached to a test tool inserted into the welded body before welding, pulled out from the transmission-side member 8 side at a speed of 5 mm / min, and the scan circuit until the welded strength of 800 N was achieved was determined and evaluated as laser weldability.

[0239] A: Welded strength of 800 N achieved by a scan circuit of 10 weeks or less

[0240] B: Welded strength of 800 N achieved by a scan circuit of 11 to 15 weeks

[0241] C: Welded strength of 800 N achieved by a scan circuit of 15 weeks

[0242] [Comprehensive Evaluation]

[0243] Based on the results shown above, comprehensive evaluation was performed using the following evaluation criteria 1 to 3.

[0244] 1: Tensile strength of 120 MPa or more, hydrolysis resistance of 60% or more, evaluation of both low warpage and surface appearance of A, relative dielectric constant of 3.40 or less, and welded strength of 800 N achieved by a scan circuit of 10 weeks or less.

[0245] 2: Tensile strength of 120 MPa or more, hydrolysis resistance of 60% or more, evaluation of low warpage and surface appearance of A or B, relative dielectric constant of 3.40 to 3.60, and welded strength of 800 N achieved by a scan circuit of 11 to 15 weeks.

[0246] 3: Any of the following at least two cases: tensile strength is 120 MPa or less, hydrolysis resistance is less than 50%, low warpage or surface appearance evaluation is C, relative dielectric constant is 3.40 or more, and welding strength of 800 N is achieved by 15 or more scanning revolutions.

[0247] However, in the case of reducing the addition amount of glass fiber, the tensile strength and the hydrolysis resistance tend to deteriorate, but if the dielectric constant, the appearance, and the welding strength are good due to product design and use environment, use is possible.

[0248] The results of these evaluations are shown in Table 4 below.

[0249] Table 4

[0250]

[0251] Industrial applicability

[0252] The thermoplastic resin composition of the present application has a low relative dielectric constant, the deviation of the relative dielectric constant of the obtained molded body is small, an excellent balance between low relative dielectric constant, low warpage, and appearance is achieved, an excellent strength and rigidity are exhibited, has high permeability and exhibits excellent laser welding properties, and thus can be advantageously used as a millimeter wave radar member.

Claims

1. A millimeter wave radar member obtained by connecting a millimeter wave radar member shaped body with a resin molded article as a mating material by means of laser welding, the millimeter wave radar member shaped body being obtained by shaping a millimeter wave radar member thermoplastic resin composition, the millimeter wave radar member thermoplastic resin composition comprising, with respect to 100 parts by mass of a polybutylene terephthalate resin (A), 15 to 65 parts by mass of a rubber-reinforced polystyrene-based resin (Bl) as a component (B), 10 to 60 parts by mass of a styrene-maleic anhydride copolymer (C), 0.1 to 3 parts by mass of an epoxy compound (D), and 30 to 150 parts by mass of a glass fiber (E) as components (B).

2. The millimeter-wave radar component of claim 1, wherein, The millimeter wave radar member thermoplastic resin composition further comprises, with respect to 100 parts by mass of the polybutylene terephthalate resin (A), 10 to 60 parts by mass of a polycarbonate resin (B2) as a component (B).

3. The millimeter-wave radar component of claim 1, wherein, The millimeter wave radar member thermoplastic resin composition further comprises, with respect to 100 parts by mass of the polybutylene terephthalate resin (A), 0.0005 to 0.5 parts by mass of a laser light-transmitting dye (F).

4. The millimeter-wave radar component of claim 1, wherein, The millimeter wave radar member thermoplastic resin composition does not contain carbon black, or the millimeter wave radar member thermoplastic resin composition contains carbon black and the content of carbon black is 0.1 parts by mass or less with respect to 100 parts by mass of the polybutylene terephthalate resin (A).

5. The millimeter wave radar component of claim 1, wherein, The glass fiber (E) has a sizing agent or a surface treatment agent that is a novolak-type epoxy compound.

6. The millimeter-wave radar component of claim 1, wherein, The millimeter wave radar member shaped body has a relative dielectric constant of 3.50 or less.

7. The millimeter-wave radar component of claim 1 or 6, wherein, The difference between the maximum value and the minimum value of the relative dielectric constant of at least 10 millimeter wave radar member shaped bodies is 0.07 or less.

8. The millimeter-wave radar component of claim 1 or 6, wherein, The millimeter wave radar member shaped body is used for a transmission side at the time of laser welding.

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