WO2009081571A1

WO2009081571A1 - Polybutylene terephthalate resin composition and thin molded article

Info

Publication number: WO2009081571A1
Application number: PCT/JP2008/003906
Authority: WO
Inventors: Sei Wakatsuka; Hiroyuki Amano
Original assignee: Wintech Polymer Ltd.
Priority date: 2007-12-25
Filing date: 2008-12-24
Publication date: 2009-07-02
Also published as: KR101520133B1; JP2009155367A; KR20100110794A; CN101910304B; CN101910304A

Abstract

Disclosed is a polybutylene terephthalate resin composition exhibiting excellent mechanical strength and impact strength, while having improved fluidity (melt fluidity). The polybutylene terephthalate resin composition hardly suffers from warping deformation. Specifically disclosed is a polybutylene terephthalate resin composition which is obtained by blending, per 100 parts by weight of a polybutylene terephthalate resin (A), 40-140 parts by weight of glass fibers (B) having a flat cross section and 0.05-5 parts by weight of a glycerol fatty acid ester (C) which is composed of glycerol and/or a dehydration condensation product thereof and a fatty acid having 12 or more carbon atoms and has a hydroxyl number as measured by the process mentioned in the description of not less than 200.

Description

Polybutylene terephthalate resin composition and thin-walled molded article

The present invention relates to a polybutylene terephthalate resin composition and a thin-walled molded article that are excellent in mechanical strength, impact strength, and fluidity and have little warping deformation. More specifically, the present invention relates to a polybutylene terephthalate resin composition and a thin-walled molded article that are optimal for molded articles such as switches and capacitors, and electrical and electronic parts.
Background art

Crystalline thermoplastic polyester resins, such as polyalkylene terephthalate resins, are excellent in mechanical properties, electrical properties, other physical and chemical properties, and have good processability. It is used for a wide range of applications such as parts.

Such crystalline thermoplastic polyester resins are used alone in various molded products, but depending on the application field, various reinforcing agents and additives may be blended for the purpose of improving their properties, particularly mechanical properties. Has been done. In fields where high mechanical strength and rigidity are required, it is well known to use fibrous reinforcing agents such as glass fibers and carbon fibers.

However, a crystalline thermoplastic polyester resin containing a general fibrous reinforcing agent has improved mechanical strength and impact strength, but has a large shrinkage anisotropy generated during the solidification process during molding such as injection molding. As a result, there is a problem that warpage deformation of the molded product becomes remarkably large. For this reason, polybutylene terephthalate resin containing a general fibrous reinforcing agent has been considered difficult to apply to thin plate-shaped molded products.

As a method for solving these problems, it has been proposed to blend an amorphous heterogeneous polymer such as polycarbonate (Japanese Patent Laid-Open No. 9-291204) with a modified polybutylene terephthalate resin. However, in the method of blending polycarbonate, there is a problem that the fluidity is remarkably lowered and the impact strength is lowered, and it is difficult to adapt to a thin molded product.

Further, although it has been proposed to use glass fibers having a flat cross section as reinforced glass fibers (Japanese Patent Laid-Open Nos. 7-309999 and 2004-248487), they have high mechanical strength and high impact strength. In order to obtain it, it is necessary to increase the filling amount of the glass fiber, which causes a problem that the fluidity is remarkably lowered and a thin molded product cannot be molded.

It is also known to add a fluidity improver to polybutylene terephthalate resin in order to improve fluidity. For example, a resin composition in which a specific aromatic polybasic acid ester is mixed as a fluidity improver is disclosed (Japanese Patent Laid-Open No. 61-85467). However, in the resin composition described in this document, the mechanical strength tends to decrease as compared with the case where no fluidity improver is added.

As described above, in the known polybutylene terephthalate resin composition, the composition showing little warpage deformation, high strength and high impact has poor fluidity, and it is extremely difficult to apply it to a thin plate-shaped molded product. there were.
Disclosure of the invention

An object of the present invention is to provide a polybutylene terephthalate resin composition having excellent mechanical strength and impact strength, little warpage deformation and improved fluidity (melt fluidity), and a molded product thereof.

As a result of intensive studies to solve the above problems, the present inventors have achieved the above object by combining a polybutylene terephthalate resin with a glass fiber having a flat cross-sectional shape and a specific glycerin fatty acid ester. The present inventors have found that a resin composition that can be obtained is obtained, and have completed the present invention.
That is, the present invention
(A) For 100 parts by weight of polybutylene terephthalate resin,
(B) 40 to 140 parts by weight of glass fiber having a flat cross-sectional shape,
(C) Polybutylene comprising glycerin and / or a dehydrated condensate thereof and a fatty acid having 12 or more carbon atoms, and 0.05 to 5 parts by weight of a glycerin fatty acid ester having a hydroxyl value measured by the method described herein of 200 or more. A terephthalate resin composition and a thin molded article comprising the same.

The polybutylene terephthalate resin composition of the present invention is excellent in mechanical strength and impact strength, has little warpage deformation, and is excellent in fluidity (melt fluidity). Applicable to molded products and suitable for various electronic equipment casings, especially switches, capacitors, connectors, integrated circuits (ICs), relays, resistors, light emitting diodes (LEDs), coil bobbins, electronic equipment, mobile phones It is suitable for molded products such as terminals, ECUs, various sensors, power modules, gear parts and their peripheral devices or their housings or chassis.
Detailed Description of the Invention

Hereinafter, the constituent components of the resin material of the present invention will be described in detail.
(A) Polybutylene terephthalate resin Polybutylene terephthalate resin is a polymerization component comprising at least terephthalic acid (terephthalic acid or an ester-forming derivative thereof) and alkylene glycol having 4 carbon atoms (1,4-butanediol or an ester-forming derivative thereof). It is a thermoplastic resin. The (A) polybutylene terephthalate resin of the present invention is not limited to polybutylene terephthalate homopolymer, but also includes polybutylene terephthalate containing isophthalic acid-modified polybutylene terephthalate and isophthalic acid-modified polyester. An isophthalic acid-modified polybutylene terephthalate and a polybutylene terephthalate containing an isophthalic acid-modified polyester can be preferably used.

Isophthalic acid-modified polybutylene terephthalate is an alkylene glycol component of 1,4-butanediol or an ester-forming derivative thereof, and isophthalic acid or an ester-forming derivative thereof together with terephthalic acid or an ester-forming derivative thereof (lower alcohol ester such as dimethyl ester) Etc.) as a comonomer unit.

The isophthalic acid-modified polyester includes terephthalic acid or an ester-forming derivative thereof and alkylene glycol having 2 to 4 carbon atoms, particularly preferably ethylene glycol, trimethylene glycol, 1,4-butanediol or an ester-forming derivative thereof. This is a copolymer comprising, as a main component, a polyester obtained by polycondensation reaction, into which isophthalic acid or an ester-forming derivative thereof (such as a lower alcohol ester such as dimethyl ester) is introduced as a comonomer unit.

The amount of isophthalic acid comonomer unit introduced in isophthalic acid-modified polybutylene terephthalate or isophthalic acid-modified polyester is preferably 5 to 30 mol%, more preferably 10 to 30 mol%, and particularly preferably 10 to 20 mol%. If the amount introduced is less than 5 mol%, the crystallinity is high, and the low warpage effect may be low. Further, when the introduction amount exceeds 30 mol%, the strength and thermal stability, which are the advantages of the original polybutylene terephthalate, are greatly reduced, and the crystallization is remarkably reduced and delayed, thereby reducing the molding cycle. There is a possibility that the mold releasability is lowered and a problem that is not practically used is caused. When a mixture of polybutylene terephthalate and isophthalic acid-modified polyester is used as the base resin, the content of isophthalic acid with respect to the total dicarboxylic acid component is preferably 5 to 30 mol%.

Polybutylene terephthalate as a base resin can be used as a copolymer copolymerized with a copolymerizable monomer (hereinafter sometimes referred to simply as a copolymerizable monomer) as long as the effects of the present invention are not impaired. it can. Examples of the copolymerizable monomer include dicarboxylic acid components excluding terephthalic acid and isophthalic acid, diols other than alkylene glycol having 2 to 4 carbon atoms, oxycarboxylic acid components, and lactone components. A copolymerizable monomer can be used 1 type or in combination of 2 or more types.

Dicarboxylic acids (or dicarboxylic acid components or dicarboxylic acids) include aliphatic dicarboxylic acids (for example, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, hexadecandioyl carboxylic acid, C _{4 ~ 40} dicarboxylic acids such as dimer acid, preferably C _{4 ~ 14} dicarboxylic acids), alicyclic dicarboxylic acid component (e.g., hexahydrophthalic acid, hexahydroisophthalic acid, hexahydroterephthalic acid, hymic C _{8 ~ 12} dicarboxylic acids, such as acid), an aromatic dicarboxylic acid component other than terephthalic acid (e.g., naphthalene dicarboxylic acids such as phthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-diphenyl dicarboxylic acid, 4, 4'-diphenoxyether dicarboxylic acid, 4,4'- Phenyl ether dicarboxylic acid, 4,4'-diphenylmethane dicarboxylic acid, 4,4'-diphenyl ketone C _{8 ~ 16} dicarboxylic acids such as dicarboxylic acids), or reactive derivatives thereof (e.g., lower alkyl esters (dimethyl phthalate, C _1-4 alkyl esters of phthalic acid, etc.), and ester-forming derivatives such as acid chlorides and acid anhydrides). Furthermore, you may use together polyvalent carboxylic acid, such as trimellitic acid and pyromellitic acid, or its ester formation derivative (alcohol ester etc.) etc. as needed. When such a polyfunctional compound is used in combination, a branched polybutylene terephthalate resin can also be obtained.

Diols (or diol components or diols) include, for example, aliphatic alkanediols excluding 1,4-butanediol [for example, alkanediols (for example, ethylene glycol, trimethylene glycol, propylene glycol, neopentyl glycol, hexanediol ( 1,6-hexanediol), octanediol (1,3-octanediol, 1,8-octanediol, etc.), lower alkane diols, such as decanediol, preferably a straight chain or branched chain C _{2 ~ 12} alkane Diols, more preferably linear or branched C _2-10 alkane diols); (poly) oxyalkylene glycols (eg glycols having a plurality of oxy C _2-4 alkylene units, eg diethylene glycol, dipropylene glycol) Ditetramethylene glycol , Triethylene glycol, tripropylene glycol, polytetramethylene glycol, etc.)], alicyclic diols (eg 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.), aromatic family diol [for example, hydroquinone, resorcinol, Jihidokishi C _{6 ~ 14} arenes such as naphthalene diol; (such as 4,4'-hydrin carboxymethyl biphenyl) biphenol; bisphenols; xylylene glycol, etc.], and reactive derivatives thereof ( For example, ester-forming derivatives such as alkyl, alkoxy or halogen-substituted products). Furthermore, if necessary, a polyol such as glycerin, trimethylolpropane, trimethylolethane, 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 can also be obtained.

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%, more preferably 5 to 5 mol%. It is about 20 mol% (for example, 5 to 15 mol%). In addition, when a homopolyester (polybutylene terephthalate) and a copolymer (copolyester) are used in combination, the proportion of the homopolyester and the copolyester is such that the proportion of the copolymerizable monomer is relative to the total monomers. The range is about 0.1 to 30 mol% (preferably 1 to 25 mol%, more preferably 5 to 25 mol%). Usually, the former / the latter = 99/1 to 1/99 (weight ratio), preferably It can be selected from the range of 95/5 to 5/95 (weight ratio), more preferably about 90/10 to 10/90 (weight ratio).

The intrinsic viscosity (IV) of the (A) polybutylene terephthalate resin is preferably 1.0 dL / g or less, and more preferably 0.9 dL / g or less. By blending polybutylene terephthalate resins or modified polyesters with different intrinsic viscosities, for example by blending polybutylene terephthalate resins with intrinsic viscosities of 1.2 dL / g and 0.8 dL / g, an intrinsic viscosity of 1.0 dL / g or less is achieved. It may be realized. 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 such a range is used, it is easy to efficiently achieve sufficient toughness and a reduced melt viscosity. If the intrinsic viscosity is too large, the melt viscosity at the time of molding becomes high, and in some cases, there is a possibility of causing poor resin flow and poor filling in the molding die.

(B) The glass fiber having a flat cross-sectional shape used in the present invention is a long diameter (longest linear distance in the cross section) and a short diameter (longest straight distance in the direction perpendicular to the long diameter). The glass fiber has a ratio of 1.3 to 10, preferably 1.5 to 8, particularly preferably 2 to 5. Specific shapes include a substantially oval shape, a substantially oval shape, a substantially eyebrow shape, and the like.

(B) Glass fiber having a flat cross-sectional shape is excellent in mechanical strength and impact strength, suppresses warpage deformation, and is excellent in moldability.

Further, the glass fiber having a flat cross-sectional shape preferably has an average cross-sectional area of 100 to 300 micro square meters. If it is smaller than 100 micro square meters, the mechanical strength and impact strength are insufficient, and if it exceeds 300 micro square meters, problems such as gate clogging at the time of injection molding and wear of molds and molding machines occur.

The amount of (B) glass fiber having a flat cross-sectional shape used in the present invention is 40 to 140 parts by weight, preferably 50 to 120 parts by weight, per 100 parts by weight of (A) polybutylene terephthalate resin. When the blending amount is less than 40 parts by weight, the mechanical strength and impact strength are low, and when it exceeds 140 parts by weight, the fluidity is remarkably deteriorated.

(B) When using a glass fiber having a flat cross-sectional shape, it is desirable to use a sizing agent or a surface treatment agent if necessary. If this example is shown, all functional compounds, such as an epoxy-type compound, an acryl-type compound, an isocyanate type compound, a silane type compound, and a titanate type compound, are used preferably. These compounds may be used after surface treatment or convergence treatment in advance, or may be added at the same time as the material preparation. The amount of the functional surface treating agent used in combination is 0 to 10% by weight, preferably 0.01 to 5% by weight, based on the filler.

Such glass fiber (B) can be used regardless of the glass fiber form at the time of blending A glass, E glass, an alkali-resistant glass composition containing a zirconia component, chopped strands, roving glass, or the like.

(B) The glass fiber having a flat cross-sectional shape used in the present invention uses a nozzle having an appropriate hole shape such as an oval, an ellipse, a rectangle, or a slit as a bushing used for discharging molten glass. Prepared by spinning. Also prepared by spinning molten glass from a plurality of adjacent nozzles having various cross-sectional shapes (including circular cross-sections), and joining the spun molten glass into a single filament it can.

Next, the (C) glycerin fatty acid ester used in the present invention is a fatty acid ester composed of glycerin and / or a dehydration condensate thereof and a fatty acid having 12 or more carbon atoms and having a hydroxyl value measured by the method described later of 200 or more. Usually, when a fluidity improver or the like is added to a polybutylene terephthalate resin, even if the fluidity can be improved, a decrease in properties such as mechanical strength and toughness of the polybutylene terephthalate resin itself cannot be avoided. In the present invention, by using the specific glycerin fatty acid ester (C), the fluidity of the polybutylene terephthalate resin composition can be efficiently improved while maintaining the above characteristics at a high level.

(C) Glycerin fatty acid ester can be produced by a method known per se, and a commercially available product may be used, and the esterification is adjusted so that the hydroxyl value measured by the method described below is 200 or more. Preferably, it has a hydroxyl value of 250 or more. When the hydroxyl value is less than 200, the effect of improving the fluidity is small, which is not preferable.

Examples of the fatty acid having 12 or more carbon atoms constituting the ester of glycerin fatty acid ester include lauric acid, oleic acid, palmitic acid, stearic acid, behenic acid, montanic acid and the like, preferably a fatty acid having 12 to 32 carbon atoms, particularly Preferably, fatty acids having 12 to 22 carbon atoms are used, and lauric acid, stearic acid or behenic acid is particularly preferred. Those having less than 12 carbon atoms are not preferable because the heat resistance may be lowered, and those having more than 32 carbon atoms are not preferable because the effect of improving fluidity is small.

Examples of preferable glycerin fatty acid esters include glycerin monostearate, glycerin monobehenate, diglycerin monostearate, triglycerin monostearate, tetraglycerin stearic acid partial ester, decaglycerin lauric acid partial ester, and the like.

The blending amount of (C) glycerin fatty acid ester is 0.05 to 5 parts by weight, preferably 0.5 to 3 parts by weight with respect to 100 parts by weight of (A) polybutylene terephthalate resin. (C) If the blending amount of glycerin fatty acid ester is less than 0.05 parts by weight, the effect of improving the fluidity may not be sufficiently obtained, and if it exceeds 5 parts by weight, the amount of gas generation increases with molding, There is a risk of damage to the appearance and mold contamination.

It should be noted that the resin composition of the present invention may contain other resins as needed within a range not impairing the effects of the present invention. Other resins include polyester resins other than polybutylene terephthalate resins (polyethylene terephthalate, polytrimethylene terephthalate, etc.), polyolefin resins, polystyrene resins, polyamide resins, polyacetals, polyarylene oxides, polyarylene sulfides, fluorine resins, etc. Is exemplified. Moreover, copolymers such as acrylonitrile-styrene resin, acrylonitrile-butadiene-styrene resin, and ethylene-ethyl acrylate resin are also exemplified. These other resins may be used alone or in combination of two or more.

Further, various additives (stabilizer, moldability improving agent, etc.) may be added to the resin composition of the present invention. Examples of additives include various stabilizers (antioxidants, ultraviolet absorbers, heat stabilizers, etc.), nucleating agents (crystallization nucleating agents), flame retardants, lubricants, mold release agents, antistatic agents, dyes / pigments, etc. Colorants, dispersants, and the like.

In particular, when polybutylene terephthalate and a modified polyester having a different alkylene glycol component are used in combination, it is preferable to add a phosphorus stabilizer to suppress transesterification. Examples of the phosphorus stabilizer used include organic phosphite compounds, phosphonite compounds, and metal phosphates. Specific examples include bis (2,4-di-t-4methylphenyl) pentaerythritol diphosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, tetrakis (2,4 Examples of the -di-t-butylphenyl) -4,4'-biphenylene phosphonite and the metal phosphate include monocalcium phosphate and monohydrate of monobasic sodium phosphate.

It should be noted that other reinforcing fillers can be added to the resin composition of the present invention as needed within a range not impairing 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, Silicates such as aluminum silicate, kaolin, talc and clay, metal oxides such as iron oxide, titanium oxide, zinc oxide, antimony oxide and alumina, carbonates and sulfates of metals such as calcium, magnesium and zinc, and carbonization Examples of the organic filler include silicon polyester, silicon nitride, boron nitride and the like, and examples of the organic filler include high melting point aromatic polyester fiber, liquid crystalline polyester fiber, aromatic polyamide fiber, fluororesin fiber, and polyimide fiber.

The composition of the present invention is easily prepared by equipment and methods generally used as conventional resin composition preparation methods. For example, after mixing each component, kneading and extruding with a single-screw or twin-screw extruder to prepare pellets, then forming the pellets, once preparing pellets with different compositions, mixing the pellets in a predetermined amount Any method can be used, such as a method of obtaining a molded product having a desired composition after molding and a method of directly charging one or more of each component into a molding machine. Further, mixing a part of the resin component as a fine powder with other components and adding it is a preferable method for uniformly blending these components. The fluidity of the resin composition of the present invention can reflect the melt viscosity under a condition under a constant piston flow shear rate as an index. For example, the melt viscosity of the resin composition of the present invention is 200 Pa · s or less, preferably 170 Pa · s or less, more preferably 150 Pa · s or less (for example, at a shear rate of 1000 sec ⁻¹ at 260 ° C. in accordance with ISO 11443 (for example, 50 to 150 Pa · s). The measurement results are obtained in units of Pa · s as described above. The lower the numerical value, the better the fluidity during melting and the better fluidity during molding.

In general, a melt index measured under conditions of ASTM D-1238 at 235 ° C and a load of 2160g is used as an index of fluidity, but the melt index is measured under a constant load. The shear rate is different. On the other hand, the melt viscosity measurement index under a constant piston flow is considered to be an index closer to the actual flow characteristics considering that actual injection molding is performed with a constant piston flow. In the present invention, the melt viscosity under such a constant shear rate condition is used as an index of fluidity.

Since the resin composition of the present invention is excellent in melt fluidity as described above, it has good moldability and is useful for producing a molded article or molded article having high mechanical strength and heat resistance. .

Especially, it is suitable for manufacturing a molded product having a thin portion. For example, it is possible to mold an injection molded product having a thickness of 1 mm or less in injection molding at a cylinder temperature of 260 ° C. and a mold temperature of 80 ° C., which are manufacturing conditions for injection molding of a normal polybutylene terephthalate resin. For example, it can be molded at an injection speed of 67 mm / sec with an injection molding machine having a clamping force of 100 t and a screw diameter of φ30 mm.

The flow length at a thickness of 1 mm may be required to be 120 mm or more, and the flow length of 120 mm or more is possible with the resin composition of the present invention.

Thin parts with a thickness of 1 mm or less in a part of the molded product include switches, capacitors, connectors, integrated circuits (ICs), relays, resistors, light emitting diodes (LEDs), coil bobbins, electronic devices, and portable terminals. , ECUs, various sensors, power modules, gear parts and their peripheral devices or their housings or chassis.

Injection molding, extrusion molding, compression molding, blow molding, vacuum molding, rotational molding, gas injection molding, etc. can be applied as a molding method for filling the resin into the mold, but injection molding is common. .
Example

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto.

Examples 1-7, Comparative Examples 1-6
Each resin composition was dry blended at the mixing ratio shown in Tables 1 and 2, and melt-kneaded at a cylinder setting temperature of 250 ° C using a twin screw extruder (manufactured by Nippon Steel Co., Ltd.) having a 30mmφ screw, then pellets Test pieces were prepared and evaluated. The results are shown in Tables 1 and 2.

Moreover, the detail of the used component and the measuring method of physical property evaluation are as follows.
(A) Polyester resin (A-1) Polybutylene terephthalate (Intrinsic viscosity IV = 0.69 dL / g, manufactured by Wintech Polymer Co., Ltd.)
(A-2) Isophthalic acid-modified polyethylene terephthalate (modified with 12.0 mol% isophthalic acid, intrinsic viscosity IV = 0.80 dL / g, manufactured by Bell Polyester Products)
(A-3) Isophthalic acid-modified polybutylene terephthalate (Intrinsic viscosity IV = 0.65dL / g)
Modified polybutylene terephthalate using 12.5 mol% of dimethylisophthalic acid as a copolymer component instead of a part of terephthalic acid (12.5 mol%) in the reaction of terephthalic acid with 1,4-butanediol
(B) Glass fiber (B-1): Glass fiber having a flat cross section (major axis / minor axis ratio: 4, average cross-sectional area 196 μm ² , manufactured by Nittobo Co., Ltd.)
(B'-1): Glass fiber having a general circular cross-section (major axis / minor axis ratio: 1, average cross-sectional area of 133 μm ² , manufactured by NEC Glass, Inc.)
(C) Glycerol fatty acid ester (C-1) Glycerol monostearate (Hydroxyl value 330, “Electro Stripper TS-5” manufactured by Kao Corporation)
(C-2) Glycerol monobehenate (Hydroxyl value 300, “Riquemar B-100” manufactured by Riken Vitamin Co., Ltd.)
(C-3) Triglycerin stearic acid partial ester (hydroxyl value 280, "Rikemar AF-70" manufactured by Riken Vitamin Co., Ltd.)
(C-4) Decaglycerin lauric acid partial ester (hydroxyl value 600, “Poem L-021” manufactured by Riken Vitamin Co., Ltd.)
(C'-1) Glycerol tristearate (hydroxyl value 87, "Poem S-95" manufactured by Riken Vitamin Co., Ltd.)
The hydroxyl value of (C) glycerin fatty acid ester was measured by the Oil Chemistry Association method 2,4,9,2-71 hydroxyl value (pyridine / acetic anhydride method).

Moreover, about Example 7, 0.15 weight part of monocalcium phosphate is further added to the composition in a table | surface.

<Tensile strength>
The obtained pellets were dried at 140 ° C. for 3 hours, then a tensile test piece was prepared by injection molding at a molding machine cylinder temperature of 260 ° C. and a mold temperature of 80 ° C., and measured according to ISO-527 (test piece thickness 4 mm). did.
<Charpy impact strength>
The obtained pellets were dried at 140 ° C. for 3 hours, then a Charpy impact test piece was prepared by injection molding at a molding machine cylinder temperature of 260 ° C. and a mold temperature of 80 ° C., according to ISO-179 (test piece thickness 4 mm). It was measured.
<Melt viscosity>
The obtained pellets were dried at 140 ° C. for 3 hours, and then, using a Capillograph 1B (manufactured by Toyo Seiki Seisakusho Co., Ltd.), in accordance with ISO 11443, a furnace temperature of 260 ° C., capillary φ1 mm × 20 mmL, shear rate 1000 sec ⁻¹ Measured with The lower the value, the better the fluidity during melting and the better fluidity during molding.
<Fluidity>
The flow length of 1 mm thickness was measured according to the following criteria.
Evaluation molded product; Spiral flow molding machine with thickness 1mm x width 20mm; FANUC S2000i-100B (screw diameter φ30mm)
Cylinder temperature: 260-260-260-230 ℃
Mold temperature: 80 ℃
Injection pressure: 98MPa
Injection speed: 67mm / sec <warp deformation>
The flatness of the flat plate was measured according to the following criteria.
Evaluation molded product; 50mm x 50mm x 1mm thickness flat plate molding machine; FANUC ROBOSHOTα-100Ia
Cylinder temperature: 260-260-240-220 ℃
Mold temperature: 80 ℃
Injection pressure: 69MPa
Flatness measuring machine: CNC image measuring machine Quick Vision QVH404 (Mitutoyo)
The flatness measurement method was performed at 9 points (vertical and horizontal 3 × 3 points) on a flat plate.

Claims

(A) For 100 parts by weight of polybutylene terephthalate resin,
(B) 40 to 140 parts by weight of glass fiber having a flat cross-sectional shape,
(C) Polybutylene comprising glycerin and / or a dehydration condensate thereof and a fatty acid having 12 or more carbon atoms, and 0.05 to 5 parts by weight of a glycerin fatty acid ester having a hydroxyl value measured by the method described herein of 200 or more. A terephthalate resin composition.
2. The polybutylene terephthalate resin composition according to claim 1, wherein the (A) polybutylene terephthalate resin is a polybutylene terephthalate containing an isophthalic acid-modified polyester, and the content of isophthalic acid in the total dicarboxylic acid component is 5 to 30 mol%. object.
2. The polybutylene terephthalate resin composition according to claim 1, wherein the (A) polybutylene terephthalate resin is 5-30 mol% isophthalic acid-modified polybutylene terephthalate.
(B) The ratio of the long diameter (longest straight line distance in the cross section) to the short diameter (long straight line and longest straight distance in the right direction) of the glass fiber having a flat cross section is 1.3 to 10 4. The polybutylene terephthalate resin composition according to claim 1, wherein the polybutylene terephthalate resin composition is between the two.
(B) The polybutylene terephthalate resin composition according to any one of claims 1 to 4, wherein the glass fiber having a flat cross-sectional shape has an average cross-sectional area of 100 to 300 micro square meters.
6. The polybutylene terephthalate resin composition according to any one of claims 1 to 5, wherein the fatty acid constituting (C) glycerin fatty acid ester is lauric acid, stearic acid or behenic acid.
The polybutylene terephthalate resin composition according to any one of claims 1 to 6, wherein a measured value of melt viscosity at a shear rate of 1000 sec -1 at a temperature of 260 ° C according to ISO11443 is 200 Pa · s or less.
The thin-walled molded article comprising the polybutylene terephthalate resin composition according to any one of claims 1 to 7, wherein a flow length at a thickness of 1 mm is 120 mm or more in injection molding at a cylinder temperature of 260 ° C and a mold temperature of 80 ° C.
The thin molded product according to claim 8, wherein a part of the molded product has a portion having a thickness of 1 mm or less.
Switches, capacitors, connectors, integrated circuits (ICs), relays, resistors, light emitting diodes (LEDs), coil bobbins, electronic devices, mobile terminals, ECUs, various sensors, power modules, gear components and their peripheral devices or their housings or The thin molded article according to claim 8 or 9, which is a chassis.