JP2020189898A - Thermoplastic resin composition for millimeter wave radar, compact and manufacturing method of resin composition - Google Patents

Abstract

To provide a thermoplastic resin composition for millimeter wave radar member having low specific permittivity, a small deviation of the specific permittivity for every obtained compact, low warping property and excellent appearance, and excellent strength and rigidity.SOLUTION: A thermoplastic resin composition for millimeter wave radar member characterized by containing, relative to 100 pts.mass of (A) a polybutylene terephthalate resin, (B) 15 to 65 pts.mass of a rubber-reinforced polystyrene-based resin, (C) 10 to 60 pts.mass of a styrene-maleic acid anhydride copolymer, (D) 0.1 to 3 pts.mass of an epoxy compound, and (E) 30 to 150 pts.mass of glass fiber.SELECTED DRAWING: None

Description

The present invention relates to a thermoplastic resin composition for a millimeter-wave radar member, a molded product, and a method for producing the resin composition. Specifically, the specific dielectric constant is low, and the variation in the specific dielectric constant of the obtained molded product is small and low. The present invention relates to a thermoplastic resin composition for a millimeter-wave radar member, which is excellent in warpage and appearance, and also has excellent strength and rigidity, a molded product made of the same, and a method for producing the resin composition.

The millimeter-wave radar emits radio waves in the millimeter-wave band, receives the reflected wave that the transmitted millimeter-wave collides with an obstacle and returns, and detects the presence of the obstacle, and detects the obstacle. Compared to other methods (optical laser radar, camera, etc.), it is less susceptible to rain, fog, backlight, etc., so it has the characteristic of being strong at night when visibility is poor and in bad weather, and prevents collisions with automobiles. It is applied to sensors, driving support systems, automatic driving systems, road information providing systems, and the like.

The millimeter-wave radar has an antenna unit built in, and a cover for the millimeter-wave radar is attached to the front of the transmitting / receiving antenna to protect the antenna surface. If the millimeter-wave radar cover does not have sufficient millimeter-wave transmission, obstacles and the like cannot be detected accurately due to the reduction of transmitted millimeter-waves and reflected waves from the transmitting and receiving antennas, and as a millimeter-wave radar. It will not be possible to meet the required performance. In order to reduce the millimeter wave transmittance, the relative permittivity is required to be low.

Patent Document 1 describes that a polybutylene terephthalate resin composition composed of a polybutylene terephthalate resin and a cyclic olefin resin having a glass transition temperature of 100 ° C. or higher is suitable as a radome for millimeter waves. However, the polybutylene terephthalate resin composition containing such a cyclic olefin resin needs further improvement as a material for millimeter-wave radar members in recent years.

In particular, recently, resin materials for millimeter-wave radar members are required to have extremely high levels of performance, and not only are they excellent in dielectric performance such as low relative permittivity, but also they are excellent in low warpage and appearance. It is also required to have excellent strength and rigidity. Further, it is required that there is no variation in the performance of the molded product obtained by molding.

Japanese Unexamined Patent Publication No. 2013-43942

An object (problem) of the present invention is a millimeter-wave radar member having a low relative permittivity, a small variation in the relative permittivity of the obtained molded product, excellent low warpage and appearance, and excellent strength and rigidity. It is an object of the present invention to provide a thermoplastic resin composition for use, a molded product made of the same, and a method for producing a thermoplastic resin composition for a millimeter-wave radar member.

As a result of diligent studies to solve the above problems, the present inventor has combined polybutylene terephthalate resin, rubber-reinforced polystyrene-based resin, styrene-maleic anhydride copolymer, epoxy compound, and glass fiber in specific amounts. We have found that the thermoplastic resin composition contained can solve the above problems, and have reached the present invention.
The present invention relates to the following thermoplastic resin composition for millimeter-wave radar members, a molded product made of the same, and a method for producing the thermoplastic resin composition.

[1] With respect to 100 parts by mass of (A) polybutylene terephthalate resin, (B) 15 to 65 parts by mass of rubber-reinforced polystyrene resin, (C) 10 to 60 parts by mass of styrene-maleic anhydride copolymer, (D). A thermoplastic resin composition for a millimeter-wave radar member, which contains 0.1 to 3 parts by mass of an epoxy compound and 30 to 150 parts by mass of (E) glass fiber.
[2] (E) The thermoplastic resin composition according to the above [1], wherein the glass fiber converging agent or surface treatment agent is a novolak type epoxy.
[3] A molded product obtained by molding the thermoplastic resin composition according to the above [1] or [2].
[4] The molded product according to the above [3], wherein the relative dielectric constant of the molded product is 3.50 or less.
[5] The molded product according to the above [3] or [4], wherein the difference between the maximum value and the minimum value of the relative permittivity of at least 10 or more molded products is 0.07 or less.
[6] The molded product according to any one of the above [3] to [5], wherein the molded product is a millimeter-wave radar member.
[7] A method for producing the thermoplastic resin composition according to the above [1] or [2] by a twin-screw kneading extruder, wherein at least the components (A) to (C) are the twin-screw kneading extruder. A method for producing a thermoplastic resin composition for a millimeter-wave radar member, which is supplied to the root, and (E) glass fiber is side-fed and kneaded under a screw kneading temperature of 200 ° C. or lower.

The thermoplastic resin composition for millimeter-wave radar members of the present invention has a low relative permittivity, a small variation in the relative permittivity of the obtained molded product, excellent low warpage and appearance, and strength and rigidity. Since it is excellent, it can be suitably used as a member for a millimeter wave radar.
Further, according to the method for producing a thermoplastic resin composition of the present invention, the relative permittivity is low, the variation in the relative permittivity of the obtained molded product is small, the warpage property and appearance are excellent, and the strength and rigidity are excellent. It is possible to easily and stably produce a thermoplastic resin composition for a millimeter-wave radar member, which is also excellent in

Hereinafter, embodiments of the present invention will be described in detail. Although the description described below may be based on embodiments and specific examples, the present invention is not construed as being limited to such embodiments and specific examples.
In addition, in this specification, when "~" is used to indicate the range by sandwiching the value before and after it with numerical values or physical property values, it means the range including the values before and after it.

The thermoplastic resin composition for millimeter-wave radar members of the present invention comprises (A) 100 parts by mass of polybutylene terephthalate resin, (B) 15 to 65 parts by mass of rubber-reinforced polystyrene resin, and (C) styrene-maleic anhydride. It is characterized by containing 10 to 60 parts by mass of a copolymer, 0.1 to 3 parts by mass of an epoxy compound (D), and 30 to 150 parts by mass of (E) glass fiber.

[(A) Polybutylene terephthalate resin]
The thermoplastic resin composition of the present invention contains (A) polybutylene terephthalate resin.
The polybutylene terephthalate resin is a polyester resin having a structure in which a terephthalic acid unit and a 1,4-butanediol unit are ester-bonded. In addition to the polybutylene terephthalate resin (copolymer), a terephthalic acid unit and 1,4-butanediol unit are used. It contains a polybutylene terephthalate copolymer containing other copolymerization components other than the butanediol unit, and a mixture of a homopolymer and the copolymer.

The polybutylene terephthalate resin may contain a dicarboxylic acid unit other than terephthalic acid, and specific examples of other dicarboxylic acids include isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, and 2,5-naphthalenedicarboxylic acid. Acid, 2,6-naphthalenedicarboxylic acid, biphenyl-2,2'-dicarboxylic acid, biphenyl-3,3'-dicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, bis (4,5'-carboxyphenyl) Aromatic dicarboxylic acids such as methane, anthracene dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, 4,4'-dicyclohexyldicarboxylic acid, and adipine. Examples thereof include aliphatic dicarboxylic acids such as acids, sebacic acids, azelaic acids and dimeric acids.

The diol unit may contain other diol units in addition to 1,4-butanediol, and specific examples of the other diol units include aliphatic or alicyclic diols having 2 to 20 carbon atoms. , Bisphenol derivatives and the like. Specific examples include ethylene glycol, propylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, decamethylene glycol, cyclohexanedimethanol, 4,4'-dicyclohexylhydroxymethane, 4 , 4'-Dicyclohexylhydroxypropane, ethylene oxide-added diol of bisphenyl A, and the like. In addition to the bifunctional monomers as described above, trifunctional monomers such as trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, and trimethylolpropane for introducing a branched structure, and fatty acids for adjusting the molecular weight, etc. A small amount of the monofunctional compound can also be used in combination.

As described above, the polybutylene terephthalate resin is preferably a polybutylene terephthalate copolymer obtained by polycondensing terephthalic acid and 1,4-butanediol, but the carboxylic acid unit is a dicarboxylic acid other than the above-mentioned terephthalic acid. A polybutylene terephthalate copolymer containing one or more and / or one or more diols other than the 1,4-butanediol may be used, and the polybutylene terephthalate resin is modified by copolymerization. In the case of a terephthalate resin, specific preferred copolymers thereof include a polyester ether resin copolymerized with polyalkylene glycols, particularly polytetramethylene glycol, a dimer acid copolymer polybutylene terephthalate resin, and an isophthalic acid copolymer. Examples include polybutylene terephthalate resin. Above all, it is preferable to use a polyester ether resin copolymerized with polytetramethylene glycol.
In addition, these copolymers have a copolymerization amount of 1 mol% or more and less than 50 mol% in all the polybutylene terephthalate resin segments. Among them, 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%. With such a copolymerization ratio, fluidity, toughness, and tracking resistance tend to be improved, which is preferable.

The amount of the terminal carboxyl group of the polybutylene terephthalate resin may be appropriately selected and determined, but is usually 60 eq / ton or less, preferably 50 eq / ton or less, and more preferably 30 eq / ton or less. preferable. If it exceeds 50 eq / ton, the alkali resistance and hydrolysis resistance are lowered, and gas is likely to be generated during melt molding of the resin composition. The lower limit of the amount of the terminal carboxyl group is not particularly determined, but is usually 10 eq / ton in consideration of the productivity of producing the polybutylene terephthalate resin.

The amount of terminal carboxyl groups in the polybutylene terephthalate resin is a value measured by titration using a 0.01 mol / l benzyl alcohol solution of sodium hydroxide in which 0.5 g of the polyalkylene terephthalate resin is dissolved in 25 mL of benzyl alcohol. is there. As a method for adjusting the amount of the terminal carboxyl group, a conventionally known arbitrary method such as a method of adjusting the polymerization conditions such as the raw material charging ratio at the time of polymerization, the polymerization temperature, the depressurization method, and the method of reacting the terminal blocking agent can be used. Just do it.

The intrinsic viscosity of the polybutylene terephthalate resin is preferably 0.5 to 2 dl / g. From the viewpoint of moldability and mechanical properties, those having an intrinsic viscosity in the range of 0.6 to 1.5 dl / g are more preferable. If an intrinsic viscosity of less than 0.5 dl / g is used, the obtained resin composition tends to have low mechanical strength. If it is higher than 2 dl / g, the fluidity of the resin composition may be deteriorated and the moldability may be deteriorated.
The intrinsic viscosity of the polybutylene terephthalate resin is a value measured at 30 ° C. in a 1: 1 (mass ratio) mixed solvent of tetrachloroethane and phenol.

Polybutylene terephthalate resin is produced by melt-polymerizing 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 by batch or continuous method. be able to. Further, the degree of polymerization (or molecular weight) can be increased to a desired value by producing a low molecular weight polybutylene telecturate resin by melt polymerization and then performing solid phase polymerization under a nitrogen stream or under reduced pressure.
The polybutylene terephthalate resin is preferably obtained by a production method in which a dicarboxylic acid component containing terephthalic acid as a main component and a diol component containing 1,4-butanediol as a main component are continuously melt-polycondensed.

The catalyst used in carrying out the esterification reaction may be a conventionally known catalyst, and examples thereof include titanium compounds, tin compounds, magnesium compounds and calcium compounds. Of these, a titanium compound is particularly suitable. Specific examples of the titanium compound as an esterification catalyst include titanium alcoholates such as tetramethyl titanate, tetraisopropyl titanate and tetrabutyl titanate, and titanium phenolates such as tetraphenyl titanate.

[(B) Rubber-reinforced polystyrene resin]
The thermoplastic resin composition of the present invention contains (B) a rubber-reinforced polystyrene-based resin.
The rubber-reinforced polystyrene-based resin is a mixture of a rubbery polymer in polystyrene. Examples of the mixing method include (1) a method of mechanically blending the two, (2) a so-called graft copolymerization method in which a styrene-based monomer or the like is graft-copolymerized in the presence of a rubbery polymer, and (3) the above. Examples thereof include a so-called graft-blending method in which general-purpose polystyrene produced by another method is mixed with the graft copolymer of (2). From the viewpoint of compatibility and affinity between polystyrene and the rubbery polymer, the graft copolymer obtained by the method (2) or the graft-blend product obtained by the method (3) is preferable. ..

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

Specific examples of the rubber polymer contained in the rubber-reinforced polystyrene-based resin include conjugated diene-based rubber such as polybutadiene, styrene-butadiene copolymer, hydrogenated styrene-butadiene block copolymer, and ethylene-propylene-based polymer. Examples thereof include non-conjugated diene rubber such as a copolymer. Of these, polyptagen is preferred.

Examples of the styrene-based monomer constituting the rubber-reinforced polystyrene-based resin include styrene, α-methylstyrene, p-methylstyrene, and bromostyrene. Of these, styrene and / or α-methylstyrene are the most suitable. Examples of the non-styrene-based monomer include vinyl-based monomers such as acrylonitrile and methyl methacrylate.

The content of the rubber polymer component in the rubber-reinforced polystyrene-based resin is preferably in the range of 1 to 50% by mass, more preferably 2 to 40% by mass, and further preferably 3 to 30% by mass. When a monomer component other than the styrene-based monomer is contained, the sum of the contents of the rubber polymer component and the styrene-based monomer component in the rubber-reinforced polystyrene-based resin is 90% by mass or more. It is desirable, and more preferably 95% by mass or more.

As the MFR that reflects the molecular weight of the rubber-reinforced polystyrene resin, the measured value under the conditions of a temperature of 200 ° C. and a load of 5 kg is preferably in the range of 0.5 to 15 g / 10 minutes, more preferably 1.0 to 10 g. The range is / 10 minutes. If the MFR is out of the above range, it may not be sufficiently compatible with the polybutylene terephthalate resin during melt-kneading, and the physical properties of the product may deteriorate.

The content of (B) rubber-reinforced polystyrene-based resin is 15 to 65 parts by mass, preferably 20 parts by mass or more, more preferably 30 parts by mass or more, and further, with respect to 100 parts by mass of (A) polybutylene terephthalate resin. It is preferably 40 parts by mass or more, preferably 60 parts by mass or less, and more preferably 55 parts by mass or less. By blending a predetermined amount of (C) styrene-maleic anhydride copolymer, (D) epoxy compound and (E) glass fiber together in such an amount, excellent dielectric properties and low warpage are obtained. A resin composition having excellent appearance, strength and rigidity can be obtained.

[(C) Styrene-maleic anhydride copolymer]
The thermoplastic resin composition of the present invention contains (C) a styrene-maleic anhydride copolymer.
The styrene-maleic anhydride copolymer is a copolymer of a styrene monomer and a maleic anhydride monomer, and is known as a production method such as an emulsion polymerization method, a solution polymerization method, a suspension polymerization method, and a radical polymerization method. A polymerization method is possible.

The molecular weight of the styrene-maleic anhydride copolymer is not particularly limited, but the weight average molecular weight Mw is preferably 1000 to 500000, more preferably 40,000 to 400,000, and further preferably 80,000 to 350,000.
Here, the weight average molecular weight Mw is a polystyrene-equivalent mass average molecular weight measured by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent.
The glass transition temperature Tg of the styrene-maleic anhydride copolymer is preferably in the range of 100 to 165 ° C.

The content of maleic anhydride in the styrene-maleic anhydride copolymer is preferably selected in the range of 1 to 20% by mass. If the amount of maleic anhydride exceeds 20% by mass, it may react excessively with the polybutylene terephthalate resin and increase the viscosity by crosslinking.

The styrene-maleic anhydride copolymer can be copolymerized with other monomer components as long as the characteristics of the present invention are not impaired. Specific examples thereof include aromatic vinyl monomers such as α-methylstyrene. Vinyl cyanide-based monomers such as acrylonitrile, unsaturated carboxylic acid alkyl ester-based monomers such as methyl methacrylate and methyl acrylate, N-methylmaleimide, N-ethylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide Examples thereof include maleimide-based monomers such as, and these can be used alone or in combination of two or more.

As the styrene-maleic anhydride copolymer (C), a styrene-maleic anhydride copolymer, which is also called an SMA resin, is preferable.

The content of the styrene-maleic anhydride copolymer is 10 to 60 parts by mass, preferably 13 parts by mass or more, and more preferably 15 parts by mass with respect to 100 parts by mass of the (A) polybutylene terephthalate resin. It is more than parts, preferably 50 parts by mass or less, and more preferably 40 parts by mass or less. By blending a predetermined amount of (B) rubber-reinforced polystyrene resin, (D) epoxy compound, and (E) glass fiber together in such an amount, excellent dielectric properties, low warpage, and appearance are obtained. A resin composition having excellent strength and rigidity can be obtained.

[(D) Epoxy compound]
The thermoplastic resin composition of the present invention contains (D) an epoxy compound.
The epoxy compound may be any one having one or more epoxy groups in one molecule, and is usually a glycidyl compound which is a reaction product of an alcohol, a phenol, a carboxylic acid or the like and epichlorohydrin, or an olefinic compound. A compound in which the double bond is epoxidized may be used.
Examples of the epoxy compound include novolak type epoxy compounds, bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, alicyclic epoxy compounds, glycidyl ethers, glycidyl esters, epoxidized butadiene polymers, resorcin type epoxy compounds and the like. Can be mentioned.

Examples of the novolak type epoxy compound include phenol novolac type epoxy compounds and cresol novolak type epoxy compounds.
Examples of the bisphenol A type epoxy compound include bisphenol A-diglycidyl ether and hydrogenated bisphenol A-diglycidyl ether. Examples of the bisphenol F type epoxy compound include bisphenol F-diglycidyl ether and hydrogenated bisphenol F-diglycidyl ether. Examples include ether.

Examples of alicyclic epoxy compounds include vinylcyclohexene dioxide, dicyclopentadiene oxide, 3,4-epoxycyclohexyl-3,4-cyclohexylcarboxylate, bis (3,4-epoxycyclohexylmethyl) adipate, and vinylcyclohexenedi. Examples thereof include epoxides and 3,4-epoxycyclohexene glycidyl ethers.

Specific examples of glycidyl ethers include monoglycidyl ethers such as methyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, decyl glycidyl ether, stearyl glycidyl ether, phenyl glycidyl ether, butyl phenyl glycidyl ether and allyl glycidyl ether; Examples thereof include diglycidyl ethers such as pentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, glycerin diglycidyl ether, propylene glycol diglycidyl ether, and bisphenol A diglycidyl ether.

Examples of the glycidyl ester include monoglycidyl esters such as benzoic acid glycidyl ester and sorbic acid glycidyl ester; and diglycidyl esters such as adipate diglycidyl ester, terephthalic acid diglycidyl ester and orthophthalic acid diglycidyl ester.

Examples of the epoxidized butadiene polymer include epoxidized polybutadiene, epoxidized styrene-butadiene copolymer, and epoxidized hydride styrene-butadiene copolymer.
Examples of the resorcin type epoxy compound include resorcin diglycidyl ether and the like.

Further, the epoxy compound may be a copolymer containing a glycidyl group-containing compound as one component. For example, a copolymer of a glycidyl ester of α, β-unsaturated acid and one or more kinds of monomers selected from the group consisting of α-olefin, acrylic acid, acrylic acid ester, methacrylic acid and methacrylic acid ester can be mentioned. Be done.

As the epoxy compound, an epoxy compound having an epoxy equivalent of 50 to 10000 g / eq and a weight average molecular weight of 8000 or less is preferable. If the epoxy equivalent is less than 50 g / eq, the amount of epoxy groups is too large and the viscosity of the resin composition becomes high. On the contrary, if the epoxy equivalent exceeds 10,000 g / eq, the amount of epoxy groups is small. The effect of improving the alkali resistance and hydrolysis resistance of the thermoplastic resin composition tends to be difficult to sufficiently exhibit. The epoxy equivalent is more preferably 100 to 7000 g / eq, even more preferably 100 to 5000 g / eq, and most preferably 100 to 3000 g / eq.
Further, when the weight average molecular weight exceeds 8000, the compatibility with the polybutylene terephthalate resin is lowered, and the mechanical strength of the molded product tends to be lowered. The weight average molecular weight is more preferably 7,000 or less, still more preferably 6000 or less.

As the epoxy compound, the bisphenol A type epoxy compound and the novolac type epoxy compound obtained from the reaction of bisphenol A and novolak with epichlorohydrin are likely to improve the alkali resistance, and also have hydrolysis resistance and a molded product. It is particularly preferable from the viewpoint of surface appearance.

The content of the epoxy compound (C) is 0.1 to 3 parts by mass, preferably 0.2 parts by mass or more, and more preferably 0.3 parts by mass or more with respect to 100 parts by mass of the polybutylene terephthalate resin (A). Further, it is preferably 0.35 parts by mass or more. Further, 2.5 parts by mass or less is preferable, 2 parts by mass or less is more preferable, and 1.5 parts by mass or less, particularly 1 part by mass or less is preferable. By containing the epoxy compound in such an amount, it is possible to reduce the molecular weight and the mechanical strength due to the hydrolysis of the polybutylene terephthalate resin, and a predetermined amount of (B) rubber-reinforced polystyrene resin, (C). By blending together with a styrene-maleic anhydride copolymer and (E) glass fiber, it is possible to obtain a resin composition having excellent dielectric properties, low warpage, appearance, strength and rigidity. it can. If the content of the epoxy compound is less than 0.1 parts by mass, the alkali resistance and the hydrolysis resistance are likely to be lowered, and if it is more than 3 parts by mass, cross-linking is likely to proceed and the fluidity during molding is likely to be deteriorated. ..

Further, the equivalent ratio (epoxy group / COOH group) of the epoxy group of the (D) epoxy compound to the terminal COOH group of the (A) polybutylene terephthalate resin is preferably in the range of 0.2 to 2.7. If the equivalent ratio is less than 0.2, the hydrolysis resistance tends to deteriorate, and if it exceeds 2.7, the moldability tends to become unstable. The epoxy group / COOH group is more preferably 0.3 or more, and 2.5 or less.

[(E) Glass fiber]
The polycarbonate resin composition of the present invention contains (E) glass fiber.
As the glass fiber, if it is usually used for a thermoplastic polyester resin, A glass, E glass, an alkali-resistant glass composition containing a zirconia component, etc. can be used, but the thermal stability of the resin composition can be improved. Non-alkali glass (E glass) is preferable for the purpose of improving.
In addition, any known glass fiber can be used regardless of the form of the glass fiber at the time of blending such as chopped strand, roving glass, a master batch of thermoplastic resin and glass fiber, but usually these fibers are used. It is preferable to use a large number of bundled pieces as chopped strand glass fiber (chopped glass fiber) cut to a predetermined length.

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

The glass fiber may be treated with a sizing agent or a surface treating agent. Further, at the time of producing the resin composition of the present invention, a sizing agent or a surface treating agent may be added separately from the untreated glass fiber for surface treatment.

Examples of the sizing agent or surface treatment agent include resin emulsions such as vinyl acetate resin, ethylene / vinyl acetate copolymer, acrylic resin, epoxy resin, polyurethane resin, and polyester resin.
Further, for example, an epoxy resin such as novolak type, an epoxy compound such as bisphenol A type epoxy resin, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropyltri. Aminosilane compounds such as methoxysilane, chlorosilane compounds such as vinyltrichlorosilane and methylvinyldichlorosilane, epoxysilanes such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane and γ-methacryloxypropyltrimethoxysilane Examples thereof include compounds, epoxysilane compounds such as β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane and γ-glycidoxypropyltrimethoxysilane, acrylic compounds, isocyanate compounds, and titanate compounds.
Among the above, the novolac type epoxy resin and the bisphenol A type epoxy resin are preferable, and the novolac type epoxy resin is particularly preferable as the sizing agent or the surface treatment agent.

Two or more of these sizing agents and surface treatment agents may be used in combination, and the amount used (adhesion amount) is usually 10% by mass or less, preferably 0.05 to 5% by mass, based on the mass of the glass fiber. Is. By setting the adhesion amount to 10% by mass or less, a necessary and sufficient effect can be obtained, which is economical.

Two or more types of glass fibers may be used in combination depending on the required properties.

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 more preferably 50 parts by mass or more, based on 100 parts by mass of the polybutylene terephthalate resin (A). Is 120 parts by mass or less, more preferably 100 parts by mass or less. By containing the molded product in such a range, the strength and heat resistance of the molded product can be improved and the shrinkage reduction effect can be enhanced. When the content exceeds 150 parts by mass, the impact resistance and fluidity are improved. Insufficient, the surface appearance of the molded product tends to deteriorate, and stable production becomes difficult. If it is less than 30 parts by mass, the effect of improving strength, rigidity, etc. is reduced.

[Other inorganic fillers]
In addition to the above-mentioned glass fibers, the thermoplastic resin composition of the present invention preferably contains other inorganic fillers in the form of plates, granules or amorphous. The plate-shaped inorganic filler exhibits a function of reducing anisotropy and warpage, and examples thereof include talc, glass flakes, mica, mica, kaolin, and metal foil. Among the plate-shaped inorganic fillers, glass flakes are preferable.
Examples of other granular or amorphous fillers include ceramic beads, clay, zeolite, barium sulfate, titanium oxide, silicon oxide, aluminum oxide, magnesium hydroxide, zinc sulfide and the like.
As other inorganic fillers, talc, titanium oxide and zinc sulfide are particularly preferable.

When the other inorganic filler is contained, the content is preferably 0.1 to 30 parts by mass, more preferably 0.5 parts by mass or more, based on 100 parts by mass of the polybutylene terephthalate resin (A). It is more preferably 1 part by mass or more, and more preferably 20 parts by mass or less.

[Stabilizer]
It is preferable that the thermoplastic resin composition of the present invention contains a stabilizer because it has an effect of improving thermal stability and preventing deterioration of mechanical strength, transparency and hue. As the stabilizer, a phosphorus-based stabilizer, a sulfur-based stabilizer and a phenol-based stabilizer are preferable.

Examples of the phosphorus-based stabilizer include phosphorous acid, phosphoric acid, phosphite ester (phosphite), trivalent phosphoric acid ester (phosphonite), pentavalent phosphoric acid ester (phosphate), and the like. , Phosphite, phosphate are preferred.

The organic phosphate compound is preferably given the following general formula:
(R ¹ O) _3-n P (= O) OH _n
(In the formula, R ¹ is an alkyl group or an aryl group, which may be the same or different. N represents an integer of 0 to 2.)
It is a compound represented by. More preferably, a long-chain alkyl acid phosphate compound having R ¹ having 8 to 30 carbon atoms can be mentioned. Specific examples of the alkyl group having 8 to 30 carbon atoms include an octyl group, a 2-ethylhexyl group, an isooctyl group, a nonyl group, an isononyl group, a decyl group, an isodecyl group, a dodecyl group, a tridecyl group, an isotridecyl group and a tetradecyl group. Examples thereof include a hexadecyl group, an octadecyl group, an eikosyl group, and a triacontyl group.

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, and 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 Examples thereof include phosphate, dioctyl acid phosphate, dilauryl acid phosphate, distearyl acid phosphate, diphenyl acid phosphate, bisnonylphenyl acid phosphate and the like. Among these, octadecyl acid phosphate is preferable, and this product is commercially available under the trade name "ADEKA STAB AX-71" of ADEKA Corporation.

The organic phosphite compound is preferably given the following general formula:
R ² OP (OR ³ ) (OR ⁴ )
^(Wherein, R 2, ^{R 3} and ^{R 4} are each a hydrogen atom, an alkyl group or an aryl group having 6 to 30 carbon atoms having 1 to 30 carbon ^atoms, of R 2, ^{R 3} and ^{R 4} At least one of them is an aryl group having 6 to 30 carbon atoms.)
Examples thereof include compounds represented by.

Examples of the organic phosphite compound include triphenylphosphite, tris (nonylphenyl) phosphite, dilaurylhydrogenphosphite, triethylphosphite, tridecylphosphite, tris (2-ethylhexyl) phosphite, and tris (tridecyl). ) Phenylphosphite, tristearyl phosphite, diphenylmonodecylphosphite, monophenyldidecylphosphite, diphenylmono (tridecyl) phosphite, tetraphenyldipropylene glycol diphosphite, tetraphenyltetra (tridecyl) pentaerythritol tetraphosphite , Hydrogenated bisphenol A phenol phosphite polymer, diphenylhydrogenphosphite, 4,4'-butylidene-bis (3-methyl-6-tert-butylphenyldi (tridecyl) phosphite), tetra (tridecyl) 4,4 '-Isopropyridene diphenyl diphosphite, bis (tridecyl) pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, dilauryl pentaerythritol diphosphite, distearyl 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) pentaerythritoldi Phosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, 2,2'-methylenebis (4,6-di-tert-butylphenyl) octylphosphite, bis ( 2,4-Dicumylphenyl) pentaerythritol diphosphite and the like. Among these, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite is preferable.

The organic phosphonite compound is preferably given the following general formula:
R ^5- P (OR ⁶ ) (OR ⁷ )
^(Wherein, R 5, ^{R 6} and ^{R 7} are each a hydrogen atom, an alkyl group or an aryl group having 6 to 30 carbon atoms having 1 to 30 carbon ^atoms, of R 5, ^{R 6} and ^{R 7} At least one of them is an aryl group having 6 to 30 carbon atoms.)
Examples thereof include compounds represented by.

Examples of the organic phosphonite compound include tetrakis (2,4-di-iso-propylphenyl) -4,4'-biphenylenediphosphonite and tetrakis (2,4-di-n-butylphenyl) -4,4'-biphenyl. Range phosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,4'-biphenylenediphosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,3'-biphenylenediphospho Nite, tetrakis (2,4-di-tert-butylphenyl) -3,3'-biphenylenediphosphonite, tetrakis (2,6-di-iso-propylphenyl) -4,4'-biphenylenediphosphonite, Tetrax (2,6-di-n-butylphenyl) -4,4'-biphenylenediphosphonite, tetrakis (2,6-di-tert-butylphenyl) -4,4'-biphenylenediphosphonite, tetrakis (2,6-di-n-butylphenyl) 2,6-di-tert-butylphenyl) -4,3'-biphenylenediphosphonite, tetrakis (2,6-di-tert-butylphenyl) -3,3'-biphenylenediphosphonite and the like. ..

As the sulfur-based stabilizer, any conventionally known sulfur atom-containing compound can be used, and among them, thioethers are preferable. Specifically, for example, didodecylthiodipropionate, ditetradecylthiodipropionate, dioctadecylthiodipropionate, pentaerythritol tetrakis (3-dodecylthiopropionate), thiobis (N-phenyl-β-naphthylamine). ), 2-Mercaptobenzothiazole, 2-mercaptobenzimidazole, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, nickeldibutyldithiocarbamate, nickelisopropylxanthate, trilauryltrithiophosphite. Of these, pentaerythritol tetrakis (3-dodecylthiopropionate) is preferred.

Examples of the phenolic stabilizer include pentaerythritol tetrakis (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate) and octadecyl-3- (3,5-di-tert-butyl-4). -Hydroxyphenyl) propionate, thiodiethylenebis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), pentaerythritol tetrakis (3- (3,5-di-neopentyl-4-hydroxyphenyl) ) Propionate) and the like. Among these, pentaerythritol tetrakis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate) and octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) ) Propionate is preferred.

One type of stabilizer may be contained, and two or more types may be contained in any combination and ratio.

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 part by mass, it is difficult to expect improvement in thermal stability and compatibility of the resin composition, and a decrease in molecular weight and deterioration of hue during molding are likely to occur. If it exceeds the amount, the amount becomes excessive, and the generation of silver and the deterioration of hue tend to occur more easily. The content of the stabilizer is more preferably 0.01 to 1.5 parts by mass, still more preferably 0.1 to 1 part by mass.

[Release agent]
The thermoplastic resin composition of the present invention preferably contains a mold release agent. As the release agent, known release agents usually used for polyester resins can be used, but among them, polyolefin-based compounds and fatty acid ester-based compounds are preferable in terms of good alkali resistance.

Examples of the polyolefin compound include compounds selected from paraffin wax and polyethylene wax, and among them, those having a weight average molecular weight of 700 to 10000, more preferably 900 to 8000 are preferable.

Examples of fatty acid ester compounds include saturated or unsaturated monovalent or divalent aliphatic carboxylic acid esters, glycerin fatty acid esters, sorbitan fatty acid esters and other fatty acid esters, and partial saponifications thereof. Among them, mono or difatty acid esters composed of fatty acids having 11 to 28 carbon atoms, preferably 17 to 21 carbon atoms and alcohols are preferable.

Examples of fatty acids include palmitic acid, stearic acid, caproic acid, caproic acid, lauric acid, araquinic acid, bechenic acid, lignoceric acid, cerotic acid, melissic acid, tetrariacontanic acid, montanic acid, adipic acid, azelaic acid and the like. Be done. Moreover, the fatty acid may be an alicyclic type.
Examples of the alcohol include saturated or unsaturated monohydric or polyhydric alcohols. These alcohols may have a substituent such as a fluorine atom or an aryl group. Among these, monohydric or polyhydric saturated alcohols having 30 or less carbon atoms are preferable, and aliphatic saturated monohydric alcohols or polyhydric alcohols having 30 or less carbon atoms are more preferable. Here, the aliphatic term also contains an alicyclic compound.
Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaerythritol and the like. Can be mentioned.
The above ester compound may contain an aliphatic carboxylic acid and / or an alcohol as an impurity, or may be a mixture of a plurality of compounds.

Specific examples of the fatty acid ester compound include glycerin monostearate, glycerin monobehenate, glycerin dibehenate, glycerin-12-hydroxymonostearate, sorbitan monobehenate, pentaerythritol monostearate, and pentaeristol distea. Examples include rate, stearyl stearate, ethylene glycol montanic acid ester and the like.

The content of the release agent is preferably 0.1 to 3 parts by mass, but more preferably 0.2 to 2.5 parts by mass with respect to 100 parts by mass of the (A) polybutylene terephthalate resin. , More preferably 0.3 to 2 parts by mass. If it is less than 0.1 part by mass, the surface property tends to be deteriorated due to poor mold release during melt molding, while if it exceeds 3 parts by mass, the kneading workability of the resin composition is likely to be deteriorated, and the molded product is formed. The surface is prone to fogging.

[Carbon black]
The thermoplastic resin composition of the present invention preferably contains carbon black.
The type, raw material type, and manufacturing method of carbon black are not limited, and any of furnace black, channel black, acetylene black, ketjen black, and the like can be used. The number average particle diameter is not particularly limited, but is preferably about 5 to 60 nm.

Carbon black is preferably blended as a masterbatch premixed with a thermoplastic resin, preferably a polybutylene terephthalate resin, particularly a polybutylene terephthalate resin.

The content of carbon black is preferably 0.1 to 4 parts by mass, and more preferably 0.2 to 3 parts by mass with respect to 100 parts by mass of the polybutylene terephthalate resin (A). If it is less than 0.1 parts by mass, a desired color may not be obtained or the effect of improving weather resistance may not be sufficient, and if it exceeds 4 parts by mass, mechanical properties may be deteriorated.

[Other ingredients]
The thermoplastic resin composition of the present invention comprises a thermoplastic resin other than the above-mentioned (A) polybutylene terephthalate resin, (B) rubber-reinforced polystyrene-based resin, and (C) styrene-maleic anhydride copolymer. It can be contained within a range that does not impair the effects of the present invention. Specific examples of other thermoplastic resins include polyethylene terephthalate resin, polyacetal resin, polyamide resin, polyphenylene oxide resin, polyphenylene sulfide resin, polysulfone resin, polyether sulfone resin, polyetherimide resin, and polyether ketone. Examples thereof include resins and polyolefin resins.
However, when the other resin is contained, the content is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and further 5 parts by mass with respect to 100 parts by mass of the (A) polybutylene terephthalate resin. Hereinafter, it is particularly preferable that the amount is 3 parts by mass or less.

Further, the thermoplastic resin composition of the present invention may contain various additives other than those described above, and such additives include flame retardants, flame retardant aids, antistatic agents, and ultraviolet absorption. Examples thereof include agents, antistatic agents, antifogging agents, antiblocking agents, plasticizers, dispersants, antibacterial agents, coloring agents other than carbon black, and dyeing pigments.

[Manufacturing of thermoplastic resin composition]
The thermoplastic resin composition of the present invention is produced by supplying the above-mentioned components (A) to (E) and other components used as necessary to an extruder, melt-kneading them, and extruding the kneaded product. .. It is preferable to extrude the kneaded product into a pellet-shaped resin composition.

Particularly preferable methods for producing the thermoplastic resin composition of the present invention include the following methods.
That is, a twin-screw kneading extruder is used as the extruder, and at least (A) polybutylene terephthalate resin, (B) rubber-reinforced polystyrene resin, and (C) styrene-maleic anhydride copolymer are used in the twin-screw kneading extruder. This is a method in which the glass fiber is supplied to the root (main feed port), side-fed, and kneaded under the condition of a screw kneading temperature of 200 ° C. or lower.

The twin-screw kneading extruder has a cylinder and two screws in the cylinder, and the cylinder uses a main feed port and a side feed port provided on the downstream side in the extrusion direction from the main feed port. To do. It is preferable that the cylinder is provided with vent portions at one or more locations.
The resin components (A) to (C) are supplied from the main feed port at the base of the extruder, and the glass fiber (E) is supplied from the side feed port of the extruder. The epoxy compound (D) may be supplied from the main feed port, the side feed port for supplying the glass fiber, or the side feed port provided separately.
The resin component supplied from the main feed port is plasticized in the first kneading portion, and (E) glass fiber is screw-kneaded into the plasticized resin component. The temperature during this screw kneading is 200 ° C. The temperature is lower than the normally applied conditions. By setting the temperature at which the glass fiber is screw-kneaded to 200 ° C. or lower, the melt viscosities of the components (B) and (C) having a low melting point (or Tg) are maintained higher than usual, and the glass fiber is opened. The shearing force for the glass fiber can be increased, the glass fiber can be sufficiently opened, and the glass fiber can be uniformly dispersed in the resin composition. The unopened fiber that remains aggregated due to insufficient opening of the glass fiber has a high relative permittivity, and if it remains and is not uniformly dispersed, the variation in the relative permittivity in the molded body becomes large, and molding The rigidity of the body tends to be insufficient, and the required performance cannot be stably achieved as a millimeter-wave radar member.

The temperature at which the glass fibers are screw-kneaded is preferably 280 ° C. or lower, more preferably 195 ° C. or lower, still more preferably 190 ° C. or lower, preferably 170 ° C. or higher, more preferably 175 ° C. or higher, still more preferably 180 ° C. It is above ℃.

[Molded product]
The method for producing a molded product using the obtained thermoplastic resin composition is not particularly limited, and a molding method generally used for the thermoplastic resin composition can be arbitrarily adopted. For example, 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 gas assist, a molding method using a heat insulating mold, and a rapid heating mold were used. Molding method, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating molding) molding method, extrusion molding method, sheet molding method, thermal molding method, rotary molding method, laminated molding method, press molding method, Blow molding method and the like can be mentioned. Among them, the injection molding method is preferable because the effects of the present invention are remarkable, such as good productivity and surface properties of the obtained molded product.

The relative permittivity of the molded product of the thermoplastic resin composition of the present invention is preferably 3.50 or less, more preferably 3.45 or less, still more preferably 3.40 or less, and particularly preferably 3.35 or less. .. The dielectric loss tangent of the molded product is preferably 0.013 or less. Both the relative permittivity and the dielectric loss tangent are numerical values at 70 to 90 GHz. Here, the thickness of the molded product is preferably 1 to 5 mm, and it is preferable that the relative permittivity and / or the dielectric loss tangent show the above values in this thickness range.
Further, the thermoplastic resin composition of the present invention has little variation in the relative permittivity of the molded product obtained by molding the same, and the difference between the maximum value and the minimum value of the relative permittivity of at least 10 or more molded products is preferably 0. It is .07 or less, particularly preferably 0.05 or less.
In the present invention, a resin containing (A) polybutylene terephthalate resin, (B) rubber-reinforced polystyrene-based resin, (C) styrene-maleic anhydride copolymer, (D) epoxy compound, and (E) glass fiber. A molded product obtained from the composition, the relative dielectric constant of the molded product at 70 to 90 GHz is preferably 3.50 or less, and particularly preferably 3.45 or less. Further, the dielectric loss tangent of the molded product at 70 to 90 GHz is preferably 0.013 or less, and particularly preferably 0.012 or less.

The obtained molded body has a low relative permittivity, a small variation in the relative permittivity for each obtained molded body, excellent low warpage and appearance, and excellent strength and rigidity. Therefore, the millimeter-wave radar member Is preferably used as. The millimeter-wave radar member includes a housing that stores or protects an antenna module that transmits or receives millimeter waves, an antenna cover (radome), and a path between the millimeter-wave radar module that includes them and an object that is sensed by millimeter waves. Includes all members installed in the vehicle (covers, vehicle exterior members, emblems, etc. installed on the millimeter-wave path transmitted and received from the millimeter-wave radar module when applied to automobile sensors).

Specific examples of millimeter-wave radar include automatic brake control device, inter-vehicle distance control device, pedestrian accident reduction steering device, false transmission suppression control device, acceleration suppression device when pedal is mistakenly pressed, approaching vehicle alert device, and lane keeping support. In-vehicle millimeter-wave radar used for devices, collision prevention warning devices, parking support devices, vehicle peripheral obstacle alerting devices, etc .; home monitoring / crossing obstacle detection devices, in-train content transmission devices, road train / railroad collision prevention Millimeter-wave radar for railways and aviation used for equipment, foreign matter detection devices in runways, etc .; Millimeter-wave radar for traffic infrastructure such as intersection monitoring devices and elevator monitoring devices; Millimeter-wave radar for various security devices; Children and elderly watching systems Millimeter-wave radars for medical / nursing care; millimeter-wave radars for transmitting various information contents; and the like can be preferably mentioned.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not construed as being limited to the following examples.
The components used in the following Examples and Comparative Examples are as shown in Table 1 below.

(Examples 1 to 3 and Comparative Example 1)
Of the components shown in Table 1 above, each component excluding glass fiber is uniformly mixed with a tumbler mixer at the ratio shown in Table 2 below (all by mass), and then a twin-screw kneading extruder (Japan). It is supplied from the main feed port of "TEX30α" manufactured by Japan Steel Works, Ltd., L / D = 42), plasticized by setting the barrel temperature of the first kneading part to 270 ° C., and the glass fiber is side feeder at the ratio shown in Table 2. The barrel temperature after the addition of glass fiber is set to 270 ° C., the mixture is melt-kneaded under the conditions of a discharge rate of 40 kg / h and a screw rotation speed of 200 rpm, the kneaded product is extruded, rapidly cooled in a water tank, and used with a pelletizer. Pellets were obtained to obtain pellets of the thermoplastic resin composition. Except for Example 2, kneading was performed under the above conditions, and the screw kneading temperature was 278 ° C.
In Example 2, the barrel temperature after the addition of the glass fiber was set to 180 ° C., and the other parts were kneaded under the same conditions as in Example 1, and the kneading temperature was 186 ° C.

[Tensile breaking strength and tensile modulus]
After the pellets obtained above are dried at 120 ° C. for 5 hours, ISO is used under the conditions of a cylinder temperature of 250 ° C. and a mold temperature of 80 ° C. using an injection molding machine (mold clamping force 85T) manufactured by Japan Steel Works, Ltd. A multipurpose test piece (4 mm thick) was injection molded.
In accordance with ISO527, the tensile breaking strength (unit: MPa) and tensile elastic modulus (unit: MPa) were measured using the above ISO multipurpose test piece (4 mm thickness).

[Hydrolysis resistance: Tensile strength retention after 100 hours of treatment]
The obtained pellets are dried at 120 ° C. for 5 hours using a hot air dryer, and then in an injection molding machine (“NEX80” manufactured by Nissei Resin Industry Co., Ltd.) under the conditions of a cylinder temperature of 250 ° C. and a mold temperature of 80 ° C. The ISO multipurpose test piece (4 mm thick) was injection-molded.
Tensile strength (before treatment) was measured using an ISO multipurpose test piece under the condition of a tensile speed of 5 mm / min in accordance with ISO527 (unit: MPa).
Further, the ISO multipurpose test piece is treated with a pressure cooker (PCT) tester (manufactured by Hirayama Seisakusho Co., Ltd.) under the conditions of a temperature of 121 ° C., a relative humidity of 100%, and a pressure of 2 atm for 100 hours to obtain the same tensile strength. The measurement was performed, the strength retention rate (unit:%) after the treatment was calculated, and the hydrolysis resistance was evaluated.

[Determining the amount of warpage and low warpage]
Using an injection molding machine (“NEX80-9E” manufactured by Nissei Resin Industry Co., Ltd.), a disk with a diameter of 100 mm and a thickness of 1.6 mm is molded with a side gate mold under the conditions of a cylinder temperature of 260 ° C and a mold temperature of 80 ° C. , The amount of warpage (unit: mm) of the disk was determined.
The evaluation judgment of low warpage was made according to the following criteria.
◯: Warp amount is less than 1 mm Δ: Warp amount is 1 mm or more and less than 3 mm ×: Warp amount is 3 mm or more

[Surface appearance evaluation]
Using an injection molding machine "NEX80-9E" manufactured by Nissei Resin Industry Co., Ltd., a flat plate of length 100 mm x width 100 mm x thickness 3 mm is molded at a cylinder temperature of 250 ° C and a mold temperature of 80 ° C, and the surface appearance is visually observed. Then, they were sorted as follows.
○: Good △: Slightly bad ×: Remarkably bad

[Relative permittivity, dielectric loss tangent]
The pellets obtained by the above method are dried at 120 ° C. for 5 hours, and then used by an injection molding machine "NEX80-9E" manufactured by Nissei Resin Industry Co., Ltd. at a cylinder temperature of 250 ° C. and a mold temperature of 80 ° C. Ten flat-plate molded bodies having a length of 100 mm, a width of 100 mm, and a thickness of about 2 mm were obtained.
The molded product thus obtained was placed on a sample table having a diameter of Φ80 mm, and a WR10-VNAX type millimeter wave module manufactured by Virginia Digides, an N5227A type network analyzer manufactured by KEYSIGN, and a transmission with a dielectric lens manufactured by Keycom Co., Ltd. Transmission attenuation and phase under measurement conditions of 25 ° C. and measurement frequency of 70 to 90 GHz by the free space frequency change method using a DPS10 type millimeter wave / microwave measurement device system manufactured by Keycom Co., Ltd. equipped with an attenuation measurement jig. The amount of change was measured. Further, the accurate thickness of the molded body was measured with a digital micrometer manufactured by Shinwa Co., Ltd., and the relative permittivity and the dielectric loss tangent were determined based on the above-mentioned transmission attenuation amount, phase change amount, and thickness measurement result.
The difference between the maximum value and the minimum value was obtained from the relative permittivity of 10 molded products.

[Comprehensive evaluation]
From the above results, the comprehensive evaluation was judged according to the following criteria 1 to 3.
1: Tensile strength is 120 MPa or more, hydrolysis resistance is 60% or more, disc warpage, appearance is evaluated as ○, relative permittivity is 3.40 or less, and the difference between the maximum and minimum relative permittivity is 0. .07 or less 2: Tensile strength of 120 MPa or more, hydrolysis resistance of 50 to 60%, disc warpage, appearance of Δ or more, relative permittivity of 3.40 or less, and measurement of 10 sheets The difference between the maximum value and the minimum value of the relative permittivity is 0.05 or less.
3: When the tensile strength is 120 MPa or more, the hydrolysis resistance is 50% or more and less than 60%, the disk warp, the appearance is Δ or more, and the relative permittivity is 3.40 or less.
The above results are shown in Table 2 below.

The thermoplastic resin composition of the present invention has a low relative permittivity, a small variation in the relative permittivity of each obtained molded product, excellent low warpage and appearance, and excellent strength and rigidity. It can be particularly preferably used for a wave radar member.

Claims (7)

(A) Polybutylene terephthalate resin 100 parts by mass, (B) rubber reinforced polystyrene resin 15 to 65 parts by mass, (C) styrene-maleic anhydride copolymer 10 to 60 parts by mass, (D) epoxy compound 0 A thermoplastic resin composition for a millimeter-wave radar member, which comprises 1 to 3 parts by mass and (E) 30 to 150 parts by mass of glass fiber. (E) The thermoplastic resin composition according to claim 1, wherein the glass fiber converging agent or surface treatment agent is a novolak type epoxy. A molded product obtained by molding the thermoplastic resin composition according to claim 1 or 2. The molded product according to claim 3, wherein the relative dielectric constant of the molded product is 3.50 or less. The molded product according to claim 3 or 4, wherein the difference between the maximum value and the minimum value of the relative permittivity of at least 10 or more molded products is 0.07 or less. The molded product according to any one of claims 3 to 5, wherein the molded product is a millimeter-wave radar member. The method for producing the thermoplastic resin composition according to claim 1 or 2 by a twin-screw kneading extruder, wherein at least the components (A) to (C) are supplied to the root of the twin-screw kneading extruder. E) A method for producing a thermoplastic resin composition for a millimeter-wave radar member, wherein the glass fiber is side-fed and kneaded under a screw kneading temperature of 200 ° C. or lower.