KR101503100B1 - Mobile terminal part - Google Patents

Abstract

The present invention provides a portable terminal component comprising a polybutadiene terephthalate resin composition excellent in physical properties such as mechanical strength and impact strength and excellent in low shrinkage and low flexural deformation. Specifically, a portable terminal component comprising a polybutylene terephthalate resin composition comprising (B) 40 to 140 parts by weight of glass fibers having a flat cross-sectional shape, with respect to 100 parts by weight of (A) modified polystyrene terephthalate resin.

Description

{MOBILE TERMINAL PART}

The present invention relates to a portable terminal component molded with a specific polybutylene terephthalate resin composition. More particularly, the present invention relates to a portable terminal component using a polybutadiene terephthalate resin composition excellent in physical properties such as mechanical strength, impact strength, and moldability such as low shrinkage and low warpage.

There is a demand for miniaturization of electric / electronic devices such as various OA devices, home appliances, and telephones, and in particular, there is a strong demand for small size and light weight in portable electronic products. 2. Description of the Related Art From the viewpoint of protecting electronic devices, metal materials such as aluminum, magnesium, and the like have been widely used as materials for housing (housings) for housing electronic devices of various portable terminals and reinforcing plates (chassis) Ceramic materials have been used. However, since the specific gravity of these materials is quite large starting from 2.69 of aluminum, the ratio of the case to the total weight of the electronic apparatus becomes large, which is considerably heavy. Further, since the metal material is expensive and difficult to be formed, there is a problem in weight, cost, and productivity. In order to solve the above problems in which a metal material is held, a plastic material having a low specific gravity, a low value and an excellent molding processability has attracted attention as an alternative material.

Since the specific gravity of a general plastic material is less than 2.0, which is smaller than the specific gravity of the metal material, it is possible to reduce the weight of the portable terminal product by applying them to the parts. The plastic material is generally molded by a method such as compression molding, injection molding, injection-compression molding, pro-molding, etc. Among them, the injection molding method is excellent in mass productivity, Which is the most commonly used molding technique. These portable terminals may be made of a polycarbonate (PC) resin, an acrylonitrile-butadiene-styrene copolymer (ABS) resin, a blend material of an ABS resin and a polycarbonate resin or a polybutylene terephthalate (PBT) (Japanese Unexamined Patent Publication (Kokai) No. Hei 7-60777) has been studied as a composite material in which reinforcing materials such as carbon fiber and glass fiber are filled.

However, the use of a general plastic material such as ABS resin, PC resin, ABS / PC resin, and ABS / PBT resin alone has relatively low mechanical strength and impact properties such as tensile strength and elastic modulus, It is necessary to use the reinforcing plate of the reinforcing plate in combination. On the other hand, a composite material reinforced with ordinary glass fibers or carbon fibers has been proposed for the purpose of improving mechanical strength, rigidity and impact properties, but the effect thereof is not sufficient, and in particular, a composite material reinforced with carbon fiber has rigidity But it was not practicable because the price of materials was remarkably high.

Further, a reinforcing resin material using a blend material of an aromatic polyamide resin and a modified polyphenylene resin (Japanese Patent Laid-Open No. 6-240132) is proposed. However, these resin materials have excellent strength and rigidity, but they have insufficient impact properties, have a large amount of gas generated at the time of molding, are inferior in molding mass productivity, and require burring treatment to occur in molded articles, There was a problem that it increased.

On the other hand, Japanese Patent Application Laid-Open No. 62-268612 discloses a polybutylene terephthalate resin composition having excellent mechanical strength by using non-circular cross-section fibers having a rectangular cross section as glass fibers. However, the ordinary polybutylene terephthalate resin has a problem that the shrinkage occurring in the solidification process during the molding process such as injection molding is large, the shrinkage of the molded article is large, and the deflection due to shrinkage anisotropy is large. It has been difficult to apply it to a molded article which requires high strength, high rigidity, high impact, shrinkage and bending deformation of the molded article at the same time as portable terminal parts.

An object of the present invention is to provide a portable terminal component comprising a polybutadiene terephthalate resin composition excellent in physical properties such as mechanical strength and impact strength and excellent in low shrinkage and low flexural deformation.

Means for Solving the Problems As a result of intensive studies in order to solve the above problems, the present inventors have found that a mobile terminal component capable of achieving the above object by molding a resin composition comprising a combination of a specific modified polystyrene terephthalate resin and a glass fiber having a flat cross- And the present invention has been accomplished.

That is,

(A) 100 parts by weight of modified polystyrene terephthalate resin,

(B) 40 to 140 parts by weight of glass fibers having a flat cross-sectional shape

And a polybutylene terephthalate resin composition comprising the polybutylene terephthalate resin composition.

The present invention is a portable terminal component application of the composition.

The portable terminal component made of the polybutylene terephthalate resin composition of the present invention is characterized in that it is lightweight and highly resistant to stiffness and impact, so that it is not easily broken. In addition, since the moldability is excellent and post-processing can be simplified, the manufacturing cost can be reduced. The present invention is suitable for a case (housing), a reinforcing plate (chassis), a frame, a hinge, or peripheral parts thereof of portable terminal parts.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing a cellular phone housing formed in the embodiment and its evaluation status. Fig.

Hereinafter, the constituent components of the resin material of the present invention will be described in detail.

The modified polystyrene terephthalate resin (A) used in the present invention refers to (1) a polybutylene terephthalate resin obtained by polycondensation reaction of a terephthalic acid or an ester-forming derivative thereof with a 1,4-butanediol or an ester- A copolymer comprising terephthalate as a main component and 5 to 30 mol% of isophthalic acid as a comonomer unit, or a polybutylene terephthalate resin containing the copolymer, (2) a terephthalic acid or an ester thereof And a modified polyethylene terephthalate copolymer containing polyethylene terephthalate as a main component obtained by polycondensation reaction of ethylene glycol or an ester forming derivative thereof and 5 to 30 mol% of isophthalic acid as a comonomer unit Is a polybutylene terephthalate resin which contains (1) and (2) Deodorant-modified polystyrene terephthalate, isophthalic acid-modified polyethylene terephthalate, and polybutylene terephthalate.

In both of (1) and (2), it is possible to use isophthalic acid as a copolymer component by using an ester-forming derivative such as a lower alcohol ester such as a dimethyl ester for polycondensation.

Here, the introduction amount of the isophthalic acid comonomer unit is 5 to 30 mol%, preferably 10 to 30 mol%, and particularly preferably 10 to 20 mol%. When the introduced amount is less than 5 mol%, the anisotropy of molding shrinkage becomes large due to the high crystallinity, and the warp deformation becomes large. If the amount is more than 30 mol%, the strength and thermal stability, which are the dominant points of the original polybutylene terephthalate, are considerably lowered, and the crystallization is remarkably reduced and delayed, resulting in a decrease in molding cycle and a decrease in releasability, There is a possibility of causing a problem that can not be practically used.

(1), either an isophthalic acid-modified copolymer alone or a combination of an isophthalic acid-modified copolymer and polybutylene terephthalate not containing an isophthalic acid component may be used. In the case of the combination, it is necessary to include an isophthalic acid component in an amount of 5 to 30 mol% based on the total dicarboxylic acid component combined with the isophthalic acid-modified copolymer and the polybutylene terephthalate not containing the isophthalic acid component. For example, the proportion of polybutylene terephthalate is less than 50% by weight among 100% by weight of the combined composition of polybutylene terephthalate having a carboxylic acid component only of terephthalic acid and a 10 mol% isophthalic acid modified copolymer.

(2), isophthalic acid-modified polyethylene terephthalate and polystyrene terephthalate are used in combination. In this case, it is necessary to include an isophthalic acid component in an amount of 5 to 30 mol% based on the entire dicarboxylic acid component in the modified polyethylene terephthalate. The ratio of the isophthalic acid-modified polyethylene terephthalate to the isophthalic acid-modified polyethylene terephthalate when the sum of the isophthalic acid-modified polyethylene terephthalate and the polystyrene terephthalate is 100% by weight is preferably 10 to 60% by weight. If it is less than 10% by weight, the effect of suppressing warp deformation is insufficient. If it exceeds 60% by weight, moldability as polystyrene terephthalate is impaired and molding at a mold temperature of 100 占 폚 or less may not be possible.

The modified polystyrene terephthalate resin (A) can be used as a copolymer copolymerized with a copolymerizable monomer (hereinafter, may be simply referred to as a copolymerizable monomer) within a range that does not impair the effect of the present invention. Examples of the copolymerizable monomer include a dicarboxylic acid component other than terephthalic acid and isophthalic acid, a diol other than an alkylene glycol having 2 to 4 carbon atoms, an oxycarboxylic acid component, and a lactone component. The copolymerizable monomers may be used alone or in combination of two or more.

Examples of dicarboxylic acids (or dicarboxylic acid components or dicarboxylic acids) include aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecane dicarboxylic acid, Kane-dicarboxylic acid, hexadecane dicarboxylic acid, dimer acid, and the like of C _{4 ~ 40-dicarboxylic} acid, preferably a C _{4 ~ 14-dicarboxylic} acid), an alicyclic dicarboxylic acid component (e.g., hexahydro phthalic acid, hexahydro isophthalic acid, hexahydro terephthalic acid, such as hydro, high-mix (hymic) acid C _{8 ~ 12-dicarboxylic} acid), terephthalic acid, aromatic dicarboxylic acid component other than the isophthalic acid (e.g., phthalic acid, naphthalene dicarboxylic acid, such as 2,6-naphthalene dicarboxylic acid, 4,4 Diphenyl dicarboxylic acid, 4,4'-diphenoxyethane dicarboxylic acid, 4,4'-diphenyl ethanedicarboxylic acid, 4,4'-diphenylmethane dicarboxylic acid, 4,4'-diphenyl ketone Dicarboxylic acids, such as available in the C _{8 ~ 16-dicarboxylic} acid), or to form esters, such as those of the reactive derivative (e.g., lower alkyl ester (the die of the acid, such as methyl acid C _{1 ~ 4} alkyl esters, etc.), acid chloride, acid anhydride Derivatives) and the like. If necessary, a polyvalent carboxylic acid such as trimellitic acid or pyromellitic acid or an ester-forming derivative thereof (such as an alcohol ester) and the like may be used in combination. When such a polyfunctional compound is used in combination, a branched polybutylene terephthalate resin in a branched form can be obtained.

The diols (or diol components or diols) include, for example, aliphatic alkene diols other than 1,4-butanediol [e.g., alkene diols (e.g., ethylene glycol, trimethylene glycol, Propylene glycol, neopentyl glycol, hexane diol (such as 1,6-hexane diol), octene diol (such as 1,3-octane diol, 1,8- ), Decanediol, and the like, preferably a linear or branched C _{2 to} C ₁₂ alkane diol, more preferably a linear or branched C _{2 to} C ₂₀ alkene diol, etc.); (Poly) oxy alkylene glycol (for example, a plurality of oxy-C _{2 ~ 4} glycol having an alkylene unit, for example, diethylene glycol, dipropylene glycol, dimethyl tetramethylene glycol, triethylene article Cyclohexanediol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A (e.g., 1,4-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, and the like), aromatic diol [for example, hydroquinone, resorcinol, naphthalene diol, such as dihydroxy C _{6 ~ 14} arene; Biphenol (4,4'-dihydroxybiphenyl and the like); Bisphenols; Xylylene glycol, and the like], and reactive derivatives thereof (e.g., ester-forming derivatives such as alkyl, alkoxy, or halogen substituents). If necessary, a polyol such as glycerin, trimethylol propane, trimethylol ethane, pentaerythritol or an ester-forming derivative thereof may be used in combination. When such a polyfunctional compound is used in combination, a branched polybutylene terephthalate resin in a branched form can be obtained.

On the other hand, in the copolymer, the proportion of the copolymerizable monomer can be selected from the range of, for example, about 0.01 to 30 mol%, and is usually 1 to 30 mol%, preferably 3 to 25 mol% 20 mol% (for example, 5 to 15 mol%). When the homopolyester (polybutylene terephthalate) and the copolymer (copolyester) are used in combination, the ratio of the homopolyester to the copolyester is preferably 0.1 to 5 parts by weight, Is preferably in the range of 30 mol% (preferably 1 to 25 mol%, and more preferably 5 to 25 mol%), and the ratio of the former to the latter is preferably 99/1 to 1/99 (weight ratio) Can be selected from the range of about 5 to 5/95 (weight ratio), and more preferably about 90/10 to 10/90 (weight ratio).

The modified polyethylene terephthalate resin can also be used as a copolymer obtained by copolymerizing with a copolymerizable monomer other than isophthalic acid within a range that does not impair the effect of the present invention.

On the other hand, the intrinsic viscosity (IV) of the modified polystyrene terephthalate resin (A) is preferably 1.2 dL / g or less, more preferably 1.0 dL / g or less. By blending a polybutylene terephthalate resin or a modified polyester having another intrinsic viscosity, for example, a polybutylene terephthalate resin having an intrinsic viscosity of 1.2 dL / g and a densities of 0.8 dL / g, an intrinsic viscosity of 1.0 dL / g or less . On the other hand, the intrinsic viscosity (IV) can be measured, for example, in o-chlorophenol at a temperature of 35 ° C. When a polybutylene terephthalate resin having an intrinsic viscosity in this range is used, impartation of sufficient toughness and reduction in melt viscosity can be efficiently realized. If the intrinsic viscosity is too large, the melt viscosity at the time of molding becomes high, and accordingly, there is a possibility that the flow of resin and the defective filling may occur in the molding die depending on the case.

The glass fiber having a flat cross-sectional shape (B) used in the present invention is a glass fiber having a flat cross section in which the ratio of the long diameter (longest straight line distance of a section) perpendicular to the longitudinal direction to the short diameter (longest straight line distance in a direction perpendicular to the long axis) To 10, preferably from 1.5 to 8, particularly preferably from 2 to 5. [ Specific examples of the shape include a substantially elliptical shape, a substantially rectangular shape, and a substantially cogged shape.

(B) The glass fiber having a flat cross-sectional shape is excellent in mechanical strength and impact strength, and has excellent moldability while suppressing warpage.

The glass fibers having a flat cross-sectional shape preferably have an average cross-sectional area of 100 to 300 square micrometers. When it is smaller than 100 square micrometers, the mechanical strength and the impact strength are not sufficient, and when it exceeds 300 square micrometers, the clogging of the gate during injection molding and the wear of the mold or the molding machine are caused.

The amount of the (B) glass fiber having a flat cross-sectional shape used in the present invention is preferably 40 to 140 parts by weight, more preferably 50 to 130 parts by weight, per 100 parts by weight of the modified polystyrene terephthalate resin (A) to be. When the blending amount is less than 40 parts by weight, the mechanical strength and the impact strength are low. When the blending amount is more than 140 parts by weight, the flowability is markedly deteriorated.

(B) In the use of the glass fiber having a flat cross-sectional shape, it is preferable to use a convergent agent or a surface treatment agent if necessary. In this example, any functional compound such as an epoxy compound, an acrylic compound, an isocyanate compound, a silane compound, or a titanate compound is preferably used. A compound such as this may be used in advance by surface treatment or convergence treatment, or may be added at the same time during preparation of the material. The amount of the functional surface treatment agent to be used in combination is from 0 to 10% by weight, preferably from 0.01 to 5% by weight, based on the filler.

Such glass fiber (B) can be used in the form of an alkali-resistant glass composition containing A glass, E glass and zirconia, and glass fiber in the form of cord strand, roving glass and the like.

The glass fiber (B) having a flat cross-sectional shape used in the present invention can be produced by spinning using a nozzle having a suitable hole shape such as a long circular shape, an elliptical shape, a rectangular shape or a slit shape as a bushing for discharging molten glass do. It is also possible to prepare molten glass by discharging molten glass from a plurality of nozzles having various cross-sectional shapes (including a circular cross section) and bonding the molten glass to each other to form a single filament.

As a portable terminal part, a resin material may be colored and used. In this case, it is common to use an inorganic white pigment at the same time as various color pigments and dyes. Examples of the inorganic white pigment suitable for the resin composition of the present invention include (C) inorganic white pigments having a Mohs hardness of 4.5 or less such as zinc sulfide, zinc oxide, barium sulfate, lithopone, magnesium carbonate, muscovite, calcium sulfate, . In these white pigments, good physical properties can be obtained because the breaking of glass fibers is small. On the other hand, rutile type titanium oxide, anatase type titanium oxide, brittle type titanium oxide and the like having a Mohs hardness of more than 4.5 often cause glass fiber breakage, which is not preferable. The amount of the inorganic white pigment to be blended is not particularly limited and may be any amount required for general coloring.

On the other hand, the resin composition of the present invention may contain other resins as needed within a range not to impair the effects of the present invention. Examples of other resins include polyester resins other than polybutylene terephthalate resin (such as polyethylene terephthalate and polytrimethylene terephthalate), polyolefin resins, polystyrene resins, polyamide resins, polyacetals, polyarylene oxides, poly Arylene sulfide, fluorine resin and the like. Further, copolymers such as acrylonitrile-styrene resin, acrylonitrile-butadiene-styrene resin, and ethylene-ethyl acrylate resin are also exemplified. These other resins may be used singly or in combination of two or more kinds.

Various additives (stabilizers, moldability improvers, etc.) may be added to the resin composition of the present invention. Examples of the additives include colorants such as various stabilizers (antioxidants, ultraviolet absorbers, heat stabilizers, etc.), nucleating agents (crystallization nucleating agents), flame retardants, lubricants, release agents, antistatic agents, salts and pigments, and dispersions.

In particular, when polybutylene terephthalate and polyesters different in alkylene glycol component including polycarbonate and polyethylene terephthalate are used in combination, it is preferable to add a phosphorus stabilizer to suppress ester exchange. Examples of the phosphorus-based stabilizer include organic phosphite-based compounds, phosphonite-based compounds and metal phosphate salts. Specific examples include bis (2,4-di-t-4-methylphenyl) pentaerythritol diphosphite, bis (2,4-di-t- butylphenyl) pentaerythritol diphosphite, tetrakis Di-t-butylphenyl) -4,4'-biphenylene phosphonite, and examples of the metal phosphate include calcium monophosphate and hydrate of sodium monophosphate.

On the other hand, other reinforcing fillers may be added to the resin composition of the present invention within a range that does not impair the effects of the present invention. Other reinforcing fillers include glass fibers other than those specified in the present invention, milled glass fibers, glass beads, glass flakes, silica, alumina fibers, zirconia fibers, potassium titanate fibers, carbon fibers, graphite, calcium silicate, Metal oxides such as iron oxide, titanium oxide, zinc oxide, antimony oxide and alumina; carbonates or sulfates of metals such as calcium, magnesium and zinc; furthermore, silicon carbide, silicon nitride, Boron nitride, and the like. Examples of the organic filler include aromatic polyester fibers having a high melting point, liquid crystalline polyester fibers, aromatic polyamide fibers, fluororesin fibers, and polyimide fibers.

The preparation of the composition of the present invention is easily prepared by the facilities and methods generally used as conventional resin composition preparation methods. For example, it is possible to prepare pellets by mixing and mixing them with a single or twin-screw extruder to form pellets, and then molding the pellets, preparing pellets having different compositions at one time, mixing the pellets in a predetermined amount, A method of obtaining a molded article having a desired composition after molding, a method of directly introducing one or more of each component into a molding machine, and the like. The addition of a part of the resin component as a fine powder in combination with other components is a preferable method for uniformly blending these components. As the molding method for filling the resin into the mold, injection molding, extrusion molding, compression molding, pro-molding, vacuum molding, rotary molding, gas injection molding and the like are applicable, but injection molding is generally used.

Example

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

Examples 1 to 8 and Comparative Examples 1 to 7

Each of the resin compositions was dry-blended at the mixing ratio shown in Table 1, melted and kneaded at a cylinder set temperature of 250 占 폚 using a twin screw extruder (made by Nippon Steel Co., Ltd.) having a screw of 30 mm, And each evaluation was conducted. The results are shown in Table 1.

The details of the components used and the method for evaluating the physical properties are as follows.

(1) Component used

(A) Component

(A-1) isophthalic acid-modified polystyrene terephthalate (intrinsic viscosity IV = 0.65 dL / g)

In the reaction of terephthalic acid and 1,4-butanediol, instead of a part of terephthalic acid (12.5 mol%), 12.5 mol% of dimethyl isophthalic acid as a copolymerization component was used to obtain modified polystyrene terephthalate

(A-2) Polystyrene terephthalate (intrinsic viscosity IV = 0.69 dL / g, manufactured by Wintec Polymer Co., Ltd.)

(A-3) isophthalic acid-modified polyethylene terephthalate (isophthalic acid 12.0 mol% modified, intrinsic viscosity IV = 0.80 dL / g, manufactured by Bell Polyester Products)

(B) glass fiber

(B-1): glass fibers having a flat cross-sectional shape (long diameter: end diameter ratio: 4, average cross section: 196 탆 ² , manufactured by Nittobo Co., Ltd.)

(B'-1): glass fibers having a general circular cross-sectional shape (long diameter: end diameter ratio: 1, average cross section: 133 탆 ² , manufactured by Nippon Electric Glass Co., Ltd.)

(C) a white pigment

(C-1) Zinc sulphide: Mohs hardness 4

(C'-1) rutile type titanium oxide: Mohs hardness 7

On the other hand, with respect to Examples 6, 7 and 8 and Comparative Example 5, 0.15 part by weight of calcium phosphate monobasic is added to the composition in the table.

(2) Evaluation of physical properties

<Tensile Strength>

The obtained pellets were dried at 140 DEG C for 3 hours and then tensile test pieces were produced by injection molding at a molding machine cylinder temperature of 260 DEG C and a mold temperature of 80 DEG C and measured according to ISO-527 (specimen thickness 4 mm).

&Lt; Charpy impact strength &

The obtained pellets were dried at 140 占 폚 for 3 hours, and Charpy impact test pieces were produced by injection molding at a molding machine cylinder temperature of 260 占 폚 and a mold temperature of 80 占 폚, and measured according to ISO-179 (test piece thickness: 4 mm).

(3) Evaluation of bending strain

The flatness of the flat plate was measured on the basis of the following criteria.

Evaluation molded article: 50 mm x 50 mm x 1 mm thick flat plate

Molding machine: FANUC ROBOSHOT α-100la

Cylinder temperature: 260-260-240-220 ℃

Mold temperature: 80 ℃

Injection pressure: 69MPa

Flatness measuring instrument: CNV image measuring instrument QuickVision QVH404 (manufactured by Mitsutoyo)

The planarity measurement method was measured at nine points on a flat plate (3 × 3 in the vertical and horizontal directions).

(4) Evaluation in cellular phone housing

The cellular phone housing shown in Fig. 1 was molded, and evaluation of (4-1) to (4-3) was carried out.

Molding machine: Sumitomo Heavy Industries SE100D

Cylinder temperature: 270-270-260-230 ° C

Mold temperature: 100 ℃

(4-1) Flexural strength of the hinge portion of the cellular phone housing

The hinge portion of Fig. 1 was pressed to measure the breaking strength.

Measuring machine: universal testing machine Tensilon UTA50KN (manufactured by Orientech)

Measuring speed: 1,000 mm / min

(4-2) Shrinkage of the boss portion of the cellular phone housing

The shrinkage state of the surface of the boss portion of Fig. 1 was visually observed.

judgment

○ ... Less contraction

× ... High shrinkage

(4-3) Grinding of the cellular phone housing (compressed heat generated by gas)

The grinding condition of the flow end of the hinge portion of Fig. 1 was visually observed.

judgment

○ ... Low number of grains

× ... Painful

Claims (8)

(A) 100 parts by weight of an isophthalic acid-modified polystyrene terephthalate resin containing 5 to 30 mol% of isophthalic acid relative to the total dicarboxylic acid component,
(B) 40 to 140 parts by weight of glass fibers having a flat cross-sectional shape
.
(B) the glass fiber having a flat cross-sectional shape has a ratio of a long diameter (longest straight line distance of a section) perpendicular to the longitudinal direction to a short diameter (longest straight line distance in a direction perpendicular to the long axis) of 1.3 to 10 And having an average cross-sectional area of 100 to 300 square micrometers, wherein the polybutylene terephthalate resin composition comprises a polybutylene terephthalate resin composition. delete delete delete delete The method according to claim 1,
Wherein the polybutylene terephthalate resin composition further comprises (C) an inorganic white pigment having a Mohs hardness of 4.5 or less, and colored with the component (C). 7. The method according to claim 1 or 6,
Portable terminal parts that are the case (housing) of a portable terminal part, a reinforcing plate (chassis), a frame, a hinge, or peripheral parts thereof. (A) 100 parts by weight of an isophthalic acid-modified polystyrene terephthalate resin containing 5 to 30 mol% of isophthalic acid relative to the total dicarboxylic acid component,
(B) 40 to 140 parts by weight of glass fibers having a flat cross-sectional shape
.
(B) the glass fiber having a flat cross-sectional shape has a ratio of a long diameter (longest straight line distance of a section) perpendicular to the longitudinal direction to a short diameter (longest straight line distance in a direction perpendicular to the long axis) of 1.3 to 10 And having an average cross-sectional area of 100 to 300 square micrometers. The present invention relates to a polybutylene terephthalate resin composition for portable terminal parts.

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