JP3291790B2 - Polyester resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to mechanical properties, heat resistance,
Excellent in moldability and appearance of the molded product, especially the thermoplastic polyester resin composition with improved deformation and low warpage, and improved weld strength, especially automotive parts, electric and electronic parts, For example, plugs, coil bobbins, sockets, switches, tuner parts, relays, capacitors, terminal boards, valves, fuse cases,
Used in applications that require high toughness and low warpage, such as flyback transformer cases, connectors, motor brush holders, lamp sockets, rear end panels, distributor caps, ignition coils, fuel pumps, transmission valves, and carburetor parts. A polyester resin composition.

[0002]

2. Description of the Related Art Thermoplastic polyester resins represented by polyethylene terephthalate and polybutylene terephthalate have excellent mechanical properties, heat resistance, chemical resistance and weather resistance, and are used as various molded products. In some cases, various reinforcing materials and additives have been blended for the purpose of further improving the properties. Particularly in fields where high strength and high rigidity are required, fibrous fillers such as glass fibers are often used. However, a composition containing a fibrous filler such as glass fiber generally has large anisotropy and high mechanical properties, but is deformed into a molded product (warpage).
Has the disadvantage of causing In order to prevent or reduce the deformation of the molded article and to increase the strength, a number of methods using titanium oxide, a particulate filler typified by glass beads, and a plate-like filler such as talc, mica, and plate-like glass have been proposed. But
Although these fillers are effective to some extent in preventing deformation, improvement in mechanical properties cannot be expected. Therefore, attempts have been made to improve both mechanical strength and deformation prevention by using a fibrous filler such as glass fiber and a plate-like filler and a granular filler together. By combining a fibrous filler and a plate-like filler such as mica, the deformation of a molded article can be reduced to some extent while maintaining the mechanical strength, as described in JP-A-53-121843, and polybutylene terephthalate. A method for improving low warpage and improving mechanical properties by combining a large particle size mica and glass fiber is disclosed in
JP-A-57-16055 discloses a method for improving low warpage and mechanical properties by combining mica and glass beads in combination with polybutylene terephthalate.
JP-A-59-6250 discloses a method for improving low warpage and improving surface smoothness by combining an amorphous polymer such as ABS and two kinds of inorganic fillers having different average particle sizes in combination with polybutylene terephthalate. Respectively.

[0003]

However, the addition of a fibrous filler such as glass fiber exhibits a large anisotropy. Therefore, the combined use of a generally used plate-like filler and a granular filler reduces mechanical strength. There is a limit in maintaining and reducing the deformation, and there is a drawback that the appearance of the molded product is greatly impaired. In addition, as for applications in which these materials are used, there are many complicated structural parts, and a confluent (weld) portion of a molten portion is easily generated in a molded product. In most cases, the formation of welds is unavoidable, but there is a drawback in that the strength of the welds is insufficient, and the weld strength is not improved with these formulations.

Accordingly, the present invention is to obtain a polyester resin composition having excellent mechanical properties, heat resistance, moldability, and appearance of a molded product in a balanced manner, in particular, an excellent effect of suppressing deformation of the molded product, and improved weld strength. Make it an issue.

That is, the present invention relates to (A) 50 to 97% by weight of a thermoplastic polyester resin and (B) (a) (a) a diene rubber and / or (b) a non-diene rubber.
(C) rubber reinforcement obtained by graft copolymerizing a monomer or a monomer mixture containing at least one selected from an aromatic vinyl monomer and (d) a vinyl cyanide monomer. With respect to 100 parts by weight of a thermoplastic polyester resin composition comprising 50 to 3% by weight of a graft copolymer or a rubber-reinforced graft copolymer which is a copolymer obtained by copolymerizing the graft copolymer and the remaining monomers. Te average particle diameter and the fibrous filler (D) is Ri range near the 20 to 120, and, D
Particles having a particle diameter of −15 ≦ d ≦ D + 15 (d: effective particles
Particle size distribution is 50% by weight or more of the whole.
The present invention provides a polyester composition containing a total of 2 to 300 parts by weight of mica .

In the composition of the present invention, it is important to use a composition comprising a thermoplastic polyester and a rubber-reinforced graft copolymer as a base polymer, and to use a fibrous filler and mica having a specific average particle size in combination. Polyester resin composition which has excellent mechanical properties, heat resistance, moldability and appearance of molded products, has excellent effect of suppressing deformation of molded products, and has improved weld strength. Things are obtained.

The thermoplastic polyester resin (A) used in the present invention is a polymer obtained by a polycondensation reaction containing dicarboxylic acid (or an ester-forming derivative thereof) and diol (or an ester-forming derivative thereof) as main components. It is a united or copolymer. As the dicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 2,6-
Such as naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, bis (p-carboxyphenyl) methane, anthracenedicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 4,4-dicarboxybiphenyl, and 5-sodium sulfoisophthalic acid Aliphatic dicarboxylic acids such as aromatic dicarboxylic acids, adipic acid, sebacic acid, azelaic acid, dodecadionic acid, alicyclic dicarboxylic acids such as 1,3-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid, and ester formation thereof Derivatives and the like. The diol component includes aliphatic glycols having 2 to 20 carbon atoms, that is, ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, decamethylene. Glycol, cyclohexanedimethanol, cyclohexanediol and the like, and ester-forming derivatives thereof and the like.

Preferred examples of these polymers and copolymers include polybutylene terephthalate, polybutylene (terephthalate / isophthalate), polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), and polybutylene (terephthalate / decanedicarboxylate). Rate), polybutylene naphthalate, polyethylene terephthalate, polyethylene (terephthalate / isophthalate), polyethylene (terephthalate / adipate), polyethylene (terephthalate / 5-sodium sulfoisophthalate),
Polyethylene (terephthalate / 5-sodium isophthalate), polyethylene (terephthalate / 5-phenyl-4,4'-dicarboxylate), polyethylene naphthalate, polycyclohexane dimethylene terephthalate, etc., and the moldability of the polyester resin composition Particularly preferred are polybutylene terephthalate, polybutylene (terephthalate / adipate), polybutylene (terephthalate / decanedicarboxylate), polybutylene naphthalate, polyethylene terephthalate, polyethylene (terephthalate / adipate), polyethylene naphthalate, and polycyclohexane dimethylene terephthalate. used.

Further, these thermoplastic polyester resins include:
The intrinsic viscosity of the o-chlorophenol solution measured at 25 ° C. is 0.36 to 1.60, particularly 0.52 to 1.35.
Are preferred in terms of mechanical properties and moldability.

(A) The blending amount of the thermoplastic polyester is 5
0 to 97% by weight, preferably 60 to 94% by weight.
0-91% by weight is preferred.

(A) If the blending amount of the thermoplastic polyester resin exceeds 97% by weight, the improvement of the mechanical properties is insufficient, and
If the amount is less than 0% by weight, the heat resistance and chemical resistance of the composition become poor, which is not preferable.

The (a) (a) diene rubber in the rubber reinforced graft copolymer (B) in the present invention includes polybutadiene rubber, acrylonitrile butadiene copolymer rubber, styrene butadiene copolymer rubber, polyisoprene rubber and the like. Examples of (a) (b) non-diene rubbers include polyolefin rubbers such as ethylene-propylene copolymer rubber, ethylene butene-1 copolymer rubber, and ethylene-propylene-non-conjugated diene rubber;
Alkyl acrylates having ~ 12 alkyl groups,
An acrylic rubber containing an alkyl methacrylate, for example, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, n-octyl methacrylate, or the like as a component may be used, and one or more of these may be used in combination.

The (b) monomer or monomer mixture contains at least one of (c) an aromatic vinyl monomer and (d) a vinyl cyanide monomer. Wherein at least one of the components is (C)
It is preferable to use an aromatic vinyl monomer, and particularly to use both components (c) and (d).

The aromatic vinyl monomer (c) includes styrene, α-methylstyrene, p-methylstyrene, pt-butylstyrene and the like, and among them, styrene and α-methylstyrene are preferred.

(D) As the vinyl cyanide monomer,
Acrylonitrile, methacrylonitrile and the like can be mentioned, among which acrylonitrile is preferable.

The composition ratio of (c) the aromatic vinyl monomer and (d) the vinyl cyanide monomer in the monomer or the monomer mixture is determined by the mechanical ratio of the obtained composition. From the viewpoint of properties and moldability, (c) the aromatic vinyl monomer is 50 to 100% by weight, preferably 55 to 90% by weight,
Particularly preferred is 57 to 82% by weight, and (d) the amount of the vinyl cyanide monomer is 0 to 50% by weight, preferably 10 to 45% by weight, and particularly preferably 18 to 43% by weight.

It is also possible to graft copolymerize another monomer copolymerizable in a range of 70 parts by weight or less based on 100 parts by weight of the total of the monomers (c) and (d). .

Other copolymerizable monomers include methyl methacrylate, ethyl methacrylate, t-methacrylate.
Α, β-unsaturated carboxylic esters such as butyl, cyclohexyl methacrylate, glycidyl acrylate, and glycidyl methacrylate; and imide compounds of α, β-unsaturated dicarboxylic acids such as maleic anhydride and itaconic anhydride. Can be

(B) The composition ratio of (a) and (b) in the rubber-reinforced graft copolymer is usually the sum of (a) and (b) in view of the mechanical properties and moldability of the composition. As 100 parts by weight, (b) is 10 to 95 parts by weight, preferably 12 to 90 parts by weight, particularly preferably 15 to 85 parts by weight.

The method for producing the rubber-reinforced graft copolymer (B) is not particularly limited, and ordinary methods such as bulk polymerization, solution polymerization, bulk suspension polymerization, suspension polymerization, and emulsion polymerization are used. There is no particular limitation on the method of charging the monomers, and they may be added all at once in the initial stage, and a part or all of the charged monomers may be continuously charged or divided in order to prevent formation of a composition distribution of the copolymer. The polymerization may be performed while charging.

(B) The compounding amount of the rubber-reinforced graft copolymer is 50 to 3% by weight, preferably 40 to 6% by weight, particularly preferably 30 to 9% by weight, and when the compounding amount is less than 3% by weight. No improvement in mechanical properties and deformation suppression effect can be expected.
If it exceeds 0% by weight, heat resistance is impaired, which is not preferred.

Examples of the fibrous filler used in the present invention include glass fibers, carbon fibers, whiskers, and organic fibers. Among them, particularly preferred fibrous fillers include glass fibers.

The fiber diameter of the fibrous filler used in the present invention is 2 to 50 μm, preferably 4 to 30 μm, and more preferably 8 to 15 μm.

Examples of the mica used in the present invention include muscovite, biotite, phlogopite and artificial mica, among which muscovite is particularly preferred.

The average particle size (D) of the mica used in the present invention is from 20 to 120 from the viewpoints of deformation suppressing effect, improvement of weld strength, melt fluidity, appearance of the molded product and mechanical properties.
μm, preferably 40 to 100 μm is suitably used. Here, the average particle diameter (D) is JIS K-51
It is a value in which the integrated weight of the particle size distribution measured by the coarse sieving method described in No. 01 shows a particle size corresponding to 50% by weight.

In order to obtain a further excellent effect in the present invention, the particle size distribution of the mica particles is d−15 ≦ d ≦ D + 15 (where D: average particle diameter (μm)). Is required to be 50% by weight or more based on the total amount of particles having
It is desirable that the content be not less than% by weight.

In order to exert the effect of the present invention, it is necessary that the average particle size of the mica satisfies the above range. If the average particle size outside this range is less than 20 μm, the surface appearance is good. The warpage of the molded product is increased, which is not preferable. If the average particle diameter exceeds 120 μm, the warpage of the molded article becomes small, but the surface appearance becomes poor, which is not preferable.
When the effective particle content is less than 50% by weight, the particle size distribution is undesirably high in warpage, which results in improved weld strength and poor mechanical properties.

The total amount of the fibrous filler and mica used in the present invention is 2 to 300 parts by weight, preferably 5 to 200 parts by weight, and more preferably 10 to 100 parts by weight. If the added amount is less than 2 parts by weight, mechanical properties cannot be expected, and if it exceeds 300 parts by weight, not only the fluidity at the time of melting becomes poor, but also the toughness decreases, which is not preferable.

The weight ratio (X / Y) of the added amount of the fibrous filler (X) and mica (Y) is from 0.05 to 15, preferably 0, from the viewpoint of mechanical properties, deformation suppressing effect and weld strength. 0.1 to 10, more preferably 0.15 to 5 can be suitably used.

The fibrous filler and mica used in the present invention can exhibit their performance by being blended as they are, but an appropriate surface treatment agent can be used to enhance the affinity and adhesion to the resin.

Examples of the surface treatment agent include a silane coupling agent, a zircoaluminate coupling agent, a titanate coupling agent, and the like. Particularly, a silane coupling agent (eg, aminosilane, epoxysilane) is preferably used. Can be. The use of a material which has been subjected to these surface treatments further improves the mechanical properties.

By using various elastomer components in combination with the composition of the present invention, the mechanical properties, deformation suppressing effect and weld strength can be further improved. Examples of such an elastomer component include (i) an epoxy group-containing copolymer composed of an α-olefin and an epoxy group-containing unsaturated monomer, (ii) ethylene and an α-olefin having 3 or more carbon atoms and / or a vinyl monomer. Consists of multimers (a)
An unmodified ethylene copolymer, (b) a modified ethylene polymer obtained by subjecting the unmodified ethylene polymer to a graft reaction with 0.01 to 10% by weight of an unsaturated carboxylic acid or a derivative thereof, (iii) (C) an unmodified olefin-based block copolymer which is a block copolymer of a hydrogenated or unhydrogenated conjugated diene and an aromatic vinyl, 0.01 to 10% by weight based on the unmodified olefin-based block copolymer (Iv) modified olefin block copolymers obtained by a graft reaction of the above unsaturated carboxylic acid or a derivative thereof.

The (i) epoxy group-containing copolymer has α
-It can be produced by a known method such as a high-pressure radical polymerization method, a solution polymerization method, or an emulsion polymerization method using an olefin and an epoxy group-containing unsaturated monomer.

Examples of the α-olefin include ethylene, propylene and butene-1, and ethylene is preferably used. Examples of the epoxy group-containing unsaturated monomer include glycidyl ethers such as allyl glycidyl ether and 2-methylallyl glycidyl ether, and glycidyl esters of the following general formula (I).

[0035]

Embedded image (In the formula, R1 is a hydrogen atom, a lower alkyl group or a lower alkyl group substituted with a glycidyl ester group.) Specific examples of the glycidyl ester include glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, and glycidyl itaconate. It is. Preferred examples of the epoxy group-containing unsaturated monomer include glycidyl methacrylate and glycidyl acrylate. The copolymerization amount of the epoxy group monomer in the epoxy group-containing copolymer is 0.1.
A suitable range is 1 to 30% by weight, preferably 1 to 20% by weight. Further, if the content is 40% by weight or less, unsaturated monomers copolymerizable with the above copolymer, ie, vinyl esters such as vinyl ethers, vinyl acetate, and vinyl propionate, and acrylic acids such as methyl, ethyl, propyl, and butyl. And methacrylic acid esters, acrylonitrile, styrene, carbon monoxide and the like may be copolymerized.

Preferred examples of the epoxy group-containing copolymer include ethylene / glycidyl methacrylate copolymer, ethylene / vinyl acetate / glycidyl methacrylate copolymer, ethylene / methyl methacrylate / glycidyl methacrylate copolymer, ethylene / Glycidyl acrylate copolymer, ethylene / vinyl acetate / glycidyl acrylate copolymer, ethylene / glycidyl ether copolymer and the like, among which ethylene / glycidyl methacrylate copolymer is most preferred.

In the present invention, when an epoxy group-containing copolymer is used, an ethylene copolymer comprising ethylene and an α-olefin having 3 or more carbon atoms and / or ethylene, an α-olefin having 3 or more carbon atoms and a non-conjugated diene are used. When the diene copolymer is used in combination, the mechanical properties can be further improved.

Specific examples of these copolymers include ethylene / propylene copolymer, ethylene / butene-1 copolymer, ethylene / pentene-1 copolymer, ethylene / propylene / butene-1 copolymer, ethylene /propylene/
5-ethylidene-2-norbornene copolymer, ethylene / propylene / 1,4-hexadiene copolymer, ethylene / propylene / dicyclopentadiene copolymer, etc., among which ethylene / propylene copolymer and ethylene / butene- One copolymer is preferred.

The copolymerization ratio (molar ratio) of ethylene to an α-olefin having 3 or more carbon atoms in the ethylene-based copolymer or diene-based copolymer is 40/60 to 99/1, preferably 70/30 to 95. / 5. The amount of the non-conjugated diene in the diene-based copolymer is 0.1 to 10 mol%, preferably 0.5 to 5 mol%.

The amount of the ethylene-based or diene-based copolymer to be added is from 0.1 to 0.1% of the epoxy-containing copolymer.
It is preferably in the range of 4 times the amount.

The (ii) (a) unmodified or (b) modified ethylene copolymer is composed of ethylene and α having 3 or more carbon atoms.
-An unmodified ethylene-based copolymer obtained by copolymerizing an olefin and / or a vinyl-based monomer, or 0.01 to 10% by weight of an unsaturated carboxylic acid or an unsaturated carboxylic acid thereof based on the unmodified ethylene-based copolymer. It refers to a modified ethylene copolymer obtained by a graft reaction of a derivative.

(Ii) (a) The α-olefin having 3 or more carbon atoms in the unmodified ethylene copolymer is preferably propylene, butene-1, pentene-1, 3-methylpentene-1, or octacene-1. And the like and / or vinyl monomers include acrylic acid or methacrylic acid esters such as methyl, ethyl, propyl, butyl, etc., acrylonitrile, styrene and the like, among which propylene, butene-1, methyl acrylate and ethyl acrylate are exemplified. More preferably, these can be used in combination of two or more. In the unmodified ethylene polymer, a non-conjugated diene may be further copolymerized.

When a non-conjugated diene is not contained, the copolymerization ratio between ethylene and an α-olefin having 3 or more carbon atoms is usually 4
0/60 to 99/1 (molar ratio), preferably 70/30
９５95/5 (molar ratio).

The copolymerization amount of the α-olefin having 3 or more carbon atoms in the ethylene copolymer containing a non-conjugated diene is usually 3 to 80 mol%, preferably 15 to 60 mol%.
And the copolymerization amount of the conjugated diene is usually 0.1 to 15 mol%, preferably 0.5 to 10 mol%.

Specific examples of the unmodified ethylene copolymer include ethylene / propylene copolymer and ethylene / butene-1
Copolymer, ethylene / pentene-1 copolymer, ethylene / propylene / butene-1 copolymer, ethylene / propylene / dicyclopentadiene copolymer, ethylene / propylene / 5-ethylidene-2-norbornene copolymer,
Ethylene / propylene / dicyclopentadiene copolymer, ethylene / methyl acrylate copolymer, ethylene /
Ethyl acrylate copolymer and the like can be mentioned, among which ethylene / propylene copolymer, ethylene / butene-1 copolymer, ethylene / methyl methacrylate copolymer, ethylene / ethyl methacrylate copolymer can be preferably used. .

As the unsaturated carboxylic acid to obtain (ii) the modified ethylene copolymer obtained by the graft reaction with the above-mentioned unmodified ethylene copolymer, it is preferable to use acrylic acid, methacrylic acid, crotonic acid, maleic acid or the like. Acid, fumaric acid, itaconic acid, citraconic acid, butenedicarboxylic acid,
And tetrahydrophthalic acid. Examples of the derivatives include alkyl esters, glycidyl esters, acid anhydrides, and imides. Of these, glycidyl esters, acid anhydrides, and imides are preferable. Preferred specific examples of unsaturated carboxylic acids or derivatives thereof include maleic acid, fumaric acid, glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, glycidyl itaconate, glycidyl citraconic acid, diglycidyl butenedicarboxylate, monoglycidyl butenedicarboxylate, Diglycidyl tetrahydrophthalate, maleic anhydride, itaconic anhydride, citraconic anhydride, maleic imide, itaconic imide, citraconic imide and the like, especially glycidyl methacrylate, glycidyl tetrahydrophthalate, maleic anhydride, itaconic anhydride, Maleic imide and the like can be preferably used. Two or more of these unsaturated monomers may be used in combination.

The (iii) unmodified and modified olefin block copolymer is used in an amount of 0.01 to 0.01% with respect to the unmodified olefin block copolymer of conjugated diene and aromatic vinyl or the unmodified olefin block copolymer. It is obtained by grafting 10% by weight of an unsaturated carboxylic acid or a derivative thereof.

The conjugated dienes are 1,3-butadiene, isoprene (2-methyl-1,3-butadiene), 2,3-butadiene,
One or more of dimethyl-1,3-butadiene, 1,3-butadiene, 1,3-pentadiene and the like, and 1,3-butadiene and isoprene can be preferably used. Styrene, α-
One or more of methylstyrene, o-methylstyrene, p-methylstyrene, 1,3-dimethylstyrene, vinylnaphthalene, etc., and styrene and α-methylstyrene can be preferably used.

The hydrogenated olefin-based block copolymer is one in which at least 80% of the unsaturated content of the unhydrogenated olefin-based block copolymer is reduced by hydrogenation. The ratio reduced by hydrogenation is desirably 10% or less.

Preferred examples of the hydrogenated or unhydrogenated olefin block copolymer include hydrogenated or unhydrogenated styrene / butadiene / styrene triblock copolymer and hydrogenated or unhydrogenated olefin block copolymer from the viewpoint of heat resistance and the like. Examples include an unhydrogenated styrene / isoprene / styrene triblock copolymer, and among them, a hydrogenated styrene / butadiene / styrene triblock copolymer is preferably used.

The unsaturated carboxylic acids and derivatives thereof to obtain the modified hydrogenated or unhydrogenated olefin block copolymer obtained by the graft reaction with the above hydrogenated or unhydrogenated olefin block copolymer include (ii) The compounds mentioned in the section of the modified ethylene copolymer can be used in the same manner.

The amount of the elastomer components (i) to (iii) can be suitably used in the range of 0.1 to 40 parts by weight, preferably 1 to 35 parts by weight, per 100 parts by weight of the thermoplastic polyester resin.

The composition of the present invention contains a nucleating agent for a thermoplastic polyester resin (for example, sodium stearate, barium stearate, sodium montanate, barium montanate, partial sodium salt of montanic acid ester, or barium salt). Metal salts of organic carboxylic acids, ionomers, talc, etc., and crystallization promoters (eg, polyethylene glycol, polyethylene glycol dibenzoate, neopentyl glycol dibenzoate, polyethylene glycol bis (2-ethylhexanote))
Such as polyalkylene glycol derivatives, benzoic acid esters, polylactones, and N-substituted toluenesulfonamide).

Various other additives (for example, release agents such as montanic acid wax, polyethylene wax, silicone oil, flame retardants, heat stabilizers, ultraviolet absorbers, pigments, dyes, etc.) are added to the composition of the present invention. can do.

Other thermoplastic resins (for example, polyethylene, polypropylene, polystyrene, acrylic resin, fluororesin, polyamide,
Polyacetal, polysulfone, polyphenylene sulfide, etc.), thermosetting resin (for example, phenolic resin,
Melamine resin, polyester resin, silicone resin, epoxy resin, etc.), soft thermoplastic resin (eg, ethylene / vinyl acetate copolymer, polyester elastomer, etc.) can be added, and further other fillers (eg, talc, kaolin,
Walathenite, clay, silica, sericite, titanium oxide, glass beads, glass balloons, glass flakes, glass powder, etc.) can be added.

The method for producing the composition of the present invention is not particularly limited. For example, a thermoplastic polyester resin, a fibrous filler, mica and other additives are blended if necessary, and the mixture is mixed with a screw extruder. A batch blending method in which pellets are adjusted, and a split blending method in which a thermoplastic polyester resin is first supplied to a screw type extruder and melted, and fillers and additives are supplied and kneaded from other supply ports and adjusted into pellets, etc. In particular, the split blending method can be suitably used.

The polyester resin composition of the present invention can be formed into a desired molded product by any molding method such as injection molding, extrusion molding, blow molding, vacuum molding and the like.

[0058]

EXAMPLES The effects of the present invention will be further described below with reference to examples.

Table 1 shows the rubber-reinforced graft copolymers used in the examples.

Examples 1 to 7 , Comparative Examples 1 to 7 Polybutylene terephthalate having an intrinsic viscosity of 0.87, a rubber-reinforced graft copolymer, mica, glass fiber, and other additives were blended in the proportions shown in Table 1 to give 250 parts. 40m set to ° C
The mixture was first melt-kneaded with a vented extruder having an mφ uniaxial screw to form pellets. After drying the pellets of the obtained composition at 130 ° C. for 5 hours, using a screw in-line type injection molding machine having a mold clamping pressure of 75 t set at 250 ° C., at a mold temperature of 80 ° C., a length of 80 mm × width 80 mm × thickness 1 mm was obtained. A square plate molded product, an ASTM No. 1 dumbbell test piece, and a two-point gate dumbbell (the same shape as the ASTM No. 1 dumbbell, a weld portion at the center) were formed.

The deformation of the molded article was measured using a square molded article. FIG. 1 is a plan view of an apparatus for measuring the amount of deformation of a molded product,
FIG. 2 is a sectional view of the same device. Square plate molded product 1 has reference surface 3
And one of the four corners is
It is fixed by. The amount of deformation of the molded article was determined by measuring the difference a between the point A on the diagonal line of the fixed point and the reference plane, and using the measured value as the amount of deformation. The surface roughness of the molded product was evaluated by measuring the irregularities generated on the surface of the molded product using a contracer. The mechanical properties of the molded article were evaluated by performing a tensile test (according to ASTM D638) using an ASTM No. 1 dumbbell.

For the weld strength, a tensile test was performed using a two-point gate dumbbell.

Table 2 shows the results. Table 3 shows a comparative example.

[0064]

[Table 1]

[Table 2]

[Table 3]

[0065]

The molded article obtained from the composition of the present invention is:
The mechanical properties, heat resistance, moldability and appearance of the molded product are balanced and excellent, especially the deformation of the molded product is small and excellent in low warpage,
Since the weld strength is improved, it is useful as a precision component material for automobiles, electric / electronic parts, and the like.

[Brief description of the drawings]

FIG. 1 is a plan view of an apparatus for measuring the amount of deformation of a molded product measured in an example.

FIG. 2 shows a sectional view of the same device.

[Explanation of symbols]

 1. Square plate molded product 2. Fixture 3. Reference plane a. clearance

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 67/00-67/04

Claims (1)

(57) [Claims] (A) a thermoplastic polyester resin 50 to 9
7% by weight of (B) (a) (a) a diene-based and / or (b) non-diene-based rubber and (b) (c) an aromatic vinyl monomer and (d) a vinyl cyanide monomer. Rubber-reinforced graft copolymer obtained by graft copolymerization of a monomer or a monomer mixture containing at least one selected from the group consisting of: The fibrous filler and the average particle diameter (D) are in the range of 20 to 1 based on 100 parts by weight of the thermoplastic polyester resin composition comprising 50 to 3% by weight of the rubber-reinforced graft copolymer as the copolymer.
Range near the 20μm is, and, D-15 ≦ d ≦ D + 15
(D: effective particle diameter μm) having a particle diameter of 5
Mica having a particle size distribution of 0% by weight or more
A polyester composition containing 300 parts by weight.