JP2023033950A - Thermoplastic polyester resin composition, molded product and method for producing thermoplastic polyester resin composition - Google Patents

Abstract

To obtain a molded product which shows excellent retention stability in spite of containing a metal hydroxide and has excellent dimensional stability and molding stability.SOLUTION: There is provided a thermoplastic polyester resin composition which is obtained by blending (B) 5 to 100 pts.wt. of a metal hydroxide and (C) 5 to 100 pts.wt. of a polyolefin resin and/or a styrene-based resin based on (A) 100 pts.wt. of a thermoplastic polyester resin, wherein the rate of change between the value of 5 minutes and the value of 15 minutes of the melt residence time of the melt flow rate measured according to ISO 1133 at a temperature condition of the melting point of the thermoplastic polyester resin + 50°C is 200% or less.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a thermoplastic polyester resin composition, a molded article obtained by molding the same, and a method for producing the same.

Thermoplastic polyester resins are used in a wide range of fields, such as mechanical parts, electric/electronic parts, and automobile parts, taking advantage of their excellent injection moldability and mechanical properties. However, the high crystallinity of the thermoplastic polyester resin, which is a factor in expressing its excellent properties, also has the property of causing dimensional changes in the molded product due to crystallization during molding. Therefore, when applying thermoplastic polyester resins to electrical and electronic parts applications that require precise dimensional stability, high dimensional stability is required to suppress deformation such as shrinkage of thermoplastic polyester resin molded products. There were cases where it was done.

There is a technology to add inorganic fillers to improve the dimensional stability of thermoplastic polyester resins. It is used in polyarylene sulfide resins, polyamide resins, etc. due to various properties such as excellent reinforcing effect, low cost, and high safety to the human body and the environment (for example, Patent Document 1). However, with respect to thermoplastic polyester resins, the use thereof has been limited due to the decomposition of thermoplastic polyester resins due to the alkalinity of magnesium hydroxide. Among them, as a thermoplastic polyester resin composition to which magnesium hydroxide is applied, a thermoplastic polyester resin composition that is blended in a small amount as an acid trapping agent (for example, Patent Document 2) and a magnesium hydroxide surface treatment that decomposes during processing a thermoplastic polyester resin composition (e.g., Patent Documents 3 and 4) in which the 5) is disclosed.

JP 2014-145006 A JP-A-2001-294050 JP-A-2005-232539 JP-A-2006-93006 JP 2019-85659 A

However, when magnesium hydroxide is applied to a thermoplastic polyester resin, in the inventions disclosed in Patent Documents 2 to 5, the amount of magnesium hydroxide that exhibits the reinforcing effect is used in the manufacturing process of the thermoplastic polyester resin composition. Although the decomposition of the thermoplastic polyester resin by magnesium hydroxide is improved to some extent, the problem is that the decomposition of the thermoplastic polyester resin progresses under long-term melt retention due to troubles during injection molding. was there.

The present invention provides a thermoplastic polyester resin composition that exhibits excellent retention stability even at a compounded amount of a metal hydroxide that exhibits a reinforcing effect, and that is capable of obtaining a molded article that is excellent in dimensional stability and molding stability. An object of the present invention is to provide a method for producing a resin composition, a molded product, and a thermoplastic polyester resin composition.

As a result of repeated studies to solve the above problems, the present inventors have found that (A) 5 to 100 parts by weight of a metal hydroxide is added to 100 parts by weight of a thermoplastic polyester resin, and ( C) The inventors have found that the above problems can be solved by adding 5 to 100 parts by weight of a polyolefin resin and/or a styrene resin, and have completed the present invention. That is, the present invention has the following configurations.
[1] (A) 100 parts by weight of thermoplastic polyester resin, (B) 5 to 100 parts by weight of metal hydroxide, and (C) 5 to 100 parts by weight of polyolefin resin and/or styrene resin (A) Melt flow rate measured according to ISO 1133 under the temperature condition of +50°C melting point of the thermoplastic polyester resin. A thermoplastic polyester resin composition which is:
[2] The thermoplastic polyester resin composition according to [1], wherein 0.5 to 15 parts by weight of (D) an acidic phosphoric acid ester compound is blended with 100 parts by weight of (A) the thermoplastic polyester resin. .
[3] The thermoplastic polyester resin composition according to [1] or [2], wherein 5 to 150 parts by weight of (E) glass fiber is blended with 100 parts by weight of (A) the thermoplastic polyester resin.
[4] A molded article obtained by injection molding the thermoplastic polyester resin composition according to any one of [1] to [3].
[5] The molded article according to [4], which is used for electric and electronic parts.
[6] (B) metal hydroxide, (C) polyolefin resin and/or styrenic resin, and (D) acidic phosphoric acid ester compound are melt-kneaded to obtain a first resin composition, and then the first resin The method for producing a thermoplastic polyester resin composition according to [2] or [3], wherein the composition and (A) the thermoplastic polyester resin are melt-kneaded.

Since the thermoplastic polyester resin composition of the present invention has excellent retention stability, it is possible to obtain a molded article having excellent molding stability and excellent dimensional stability.

Next, the thermoplastic polyester resin composition of the present invention will be described in detail.

The thermoplastic polyester resin composition of the present invention comprises (A) 100 parts by weight of the thermoplastic polyester resin, (B) 5 to 100 parts by weight of a metal hydroxide, and (C) a polyolefin resin and / or a styrene-based 5 to 100 parts by weight of a resin is blended, and the melt flow rate measured according to ISO 1133 at a temperature condition of (A) the melting point of the thermoplastic polyester resin + 50 ° C. is 5 minutes and 15 minutes. It is a thermoplastic polyester resin composition having a rate of change in value of 200% or less.

In (A) thermoplastic polyester resin, the ester bond is decomposed by the alkalinity of (B) metal hydroxide, and decomposition is accelerated especially under long-term melt retention, resulting in a decrease in mechanical strength. In the present invention, (A) 5 to 100 parts by weight of a metal hydroxide and (C) 5 to 100 parts by weight of a polyolefin resin and/or a styrene resin are blended with 100 parts by weight of a thermoplastic polyester resin. do. Since the surface of the alkaline metal hydroxide is covered with a polyolefin resin and/or a styrenic resin, contact with the thermoplastic polyester resin is suppressed, so that the resulting thermoplastic polyester resin composition remains molten. It is possible to suppress the decomposition at , and it is possible to achieve excellent molding stability of the thermoplastic polyester resin composition and high dimensional stability of the obtained molded article.

Here, the thermoplastic polyester resin composition of the present invention includes reactants obtained by reacting components (A), (B), and (C) with other components. Circumstances exist where it is impractical to specify the structure of a generated object. Therefore, the present invention specifies the invention by the components to be blended.

The (A) thermoplastic polyester resin used in the present invention includes (1) a dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof, (2) a hydroxycarboxylic acid or an ester-forming derivative thereof, and (3) ) A polymer or copolymer whose main structural unit is at least one residue selected from the group consisting of lactones. Here, "main structural unit" means having 50 mol% or more of at least one residue selected from the group consisting of (1) to (3) in all structural units, and those residues It is a preferred embodiment to have 80 mol % or more. Among these, (1) a polymer or copolymer having residues of a dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof as a main structural unit is preferable from the viewpoint of excellent mechanical properties and heat resistance. .

Examples of the dicarboxylic acids or ester-forming derivatives thereof include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, bis(p-carboxyphenyl)methane, and anthracene. Dicarboxylic acids, aromatic dicarboxylic acids such as 4,4'-diphenyl ether dicarboxylic acid, 5-tetrabutylphosphonium isophthalic acid, 5-sodium sulfoisophthalic acid, oxalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedione aliphatic dicarboxylic acids such as acids, malonic acid, glutaric acid and dimer acid; alicyclic dicarboxylic acids such as 1,3-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid; and ester-forming derivatives thereof. . You may use 2 or more types of these.

Examples of diols or ester-forming derivatives thereof include ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, and decamethylene glycol. , cyclohexanedimethanol, cyclohexanediol, dimer diol, aliphatic or alicyclic glycols having 2 to 20 carbon atoms, polyethylene glycol, poly-1,3-propylene glycol, polytetramethylene glycol, molecular weight 200 to 100,000 aromatic dioxy compounds such as 4,4'-dihydroxybiphenyl, hydroquinone, t-butylhydroquinone, bisphenol A, bisphenol S and bisphenol F, and ester-forming derivatives thereof. You may use 2 or more types of these.

Examples of polymers or copolymers having structural units of a dicarboxylic acid or its ester-forming derivative and a diol or its ester-forming derivative include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polypropylene isophthalate, and polybutylene isophthalate. , polybutylene naphthalate, polypropylene isophthalate/terephthalate, polybutylene isophthalate/terephthalate, polypropylene terephthalate/naphthalate, polybutylene terephthalate/naphthalate, polybutylene terephthalate/decanedicarboxylate, polypropylene terephthalate/5-sodium sulfoisophthalate, poly Butylene terephthalate/5-sodium sulfoisophthalate, polypropylene terephthalate/polyethylene glycol, polybutylene terephthalate/polyethylene glycol, polypropylene terephthalate/polytetramethylene glycol, polybutylene terephthalate/polytetramethylene glycol, polypropylene terephthalate/isophthalate/polytetramethylene glycol , polybutylene terephthalate/isophthalate/polytetramethylene glycol, polybutylene terephthalate/succinate, polypropylene terephthalate/adipate, polybutylene terephthalate/adipate, polypropylene terephthalate/sebacate, polybutylene terephthalate/sebacate, polypropylene terephthalate/isophthalate/adipate, poly Aromatic polyester resins such as butylene terephthalate/isophthalate/succinate, polybutylene terephthalate/isophthalate/adipate, and polybutylene terephthalate/isophthalate/sebacate. Here, "/" represents a copolymer.

Among these, from the viewpoint of further improving mechanical properties and heat resistance, polymers having residues of aromatic dicarboxylic acids or ester-forming derivatives thereof and residues of aliphatic diols or ester-forming derivatives thereof as main structural units Or a copolymer is more preferable, and mainly comprises a residue of terephthalic acid, naphthalene dicarboxylic acid or an ester-forming derivative thereof and an aliphatic diol selected from propylene glycol, 1,4-butanediol or an ester-forming derivative thereof. A polymer or copolymer as a structural unit is more preferable.

Aromatic polyester resins such as polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polypropylene naphthalate, polybutylene naphthalate, polypropylene isophthalate/terephthalate, polybutylene isophthalate/terephthalate, polypropylene terephthalate/naphthalate and polybutylene terephthalate/naphthalate among others are particularly preferred, polyethylene terephthalate, polypropylene terephthalate and polybutylene naphthalate are more preferred, and polybutylene terephthalate is even more preferred from the viewpoint of excellent moldability and crystallinity. Moreover, these 2 or more types can also be used by arbitrary content.

In the present invention, terephthalic acid or terephthalic acid or The ratio of the ester-forming derivative is preferably 30 mol % or more, more preferably 40 mol % or more.

In the present invention, a liquid crystalline polyester resin capable of forming anisotropy when melted can be used as (A) the thermoplastic polyester resin. Structural units of the liquid crystalline polyester resin include, for example, aromatic oxycarbonyl units, aromatic dioxy units, aromatic and/or aliphatic dicarbonyl units, alkylenedioxy units and aromatic iminooxy units.

The (A) thermoplastic polyester resin used in the present invention preferably has a melt flow rate of 0.1 g/10 minutes or more from the viewpoint of further improving fluidity. It is more preferably 1 g/10 minutes or more, and still more preferably 5 g/10 minutes. Further, the upper limit of the melt flow rate is preferably 100 g/10 minutes or less because the mechanical properties can be improved. It is more preferably 75 g/10 minutes or less, still more preferably 50 g/10 minutes or less. In the present invention, the melt flow rate of (A) thermoplastic polyester resin is a value measured according to ISO 1133 at the melting point of (A) thermoplastic polyester resin +20° C. and a load of 1000 gf.

The (A) thermoplastic polyester resin used in the present invention can be produced by a known polycondensation method, ring-opening polymerization method, or the like. The production method may be either batch polymerization or continuous polymerization, and can be applied to either transesterification or direct polymerization. From the viewpoint of productivity, continuous polymerization is preferred, and direct polymerization is preferred. It is used more preferably. Moreover, in order to effectively advance the esterification reaction, the transesterification reaction, and the polycondensation reaction, it is preferable to add a polymerization reaction catalyst during these reactions.

The thermoplastic polyester resin composition of the present invention contains (B) a metal hydroxide in order to improve the dimensional stability of the resulting molded article while maintaining retention stability and molding stability.

The (B) metal hydroxide of the present invention is a compound composed of a metal element and a hydroxyl group, and examples thereof include magnesium hydroxide, calcium hydroxide, aluminum hydroxide and manganese hydroxide. Among them, magnesium hydroxide is preferable from the viewpoint of the reinforcing effect.

The purity of the magnesium hydroxide in the present invention is preferably 80% by weight or more, more preferably 90% by weight or more, still more preferably 90% by weight or more of the compound represented by the chemical formula Mg(OH) ₂ . is 95% by weight or more. Magnesium hydroxide may contain impurities resulting from raw materials and manufacturing processes, such as compounds such as magnesium oxide, calcium oxide, iron, and sodium, as long as the object of the present invention is not impaired.

The method for producing magnesium hydroxide in the present invention includes the reaction of seawater, bittern, etc. with a basic aqueous solution, synthesis by hydration reaction of magnesium oxide, dry pulverization and wet pulverization of brucite, which is a natural ore. There may be.

Magnesium hydroxide in the present invention is commercially available as "Kisuma" 5 series manufactured by Kyowa Chemical Industry Co., Ltd., "MAGSTAR" manufactured by Tateho Chemical Industry Co., Ltd., and "Junmag series" manufactured by Fimatech Co., Ltd. etc.

The average particle size of (B) the metal hydroxide in the present invention is preferably 0.1 to 20 μm. It is preferable that the average particle size is 0.1 μm or more because the decomposition of the thermoplastic polyester resin composition under molten retention is suppressed. 0.5 μm or more is more preferable, and 1 μm or more is even more preferable. On the other hand, when the average particle size is 20 μm or less, the dimensional stability of molded articles of the thermoplastic polyester resin composition is excellent, which is preferable. 15 μm or less is more preferable. Here, the average particle size is determined as _D50 using a laser diffraction scattering method.

The (B) metal hydroxide in the present invention may be surface-treated. The surface treatment can improve the reactivity between magnesium hydroxide and (C) the polyolefin resin and/or the styrenic resin. Examples of surface treatments include higher fatty acids and metal salts thereof, silane coupling agents, phosphate esters, silicone oils, and the like.

The metal hydroxide (B) in the present invention may be used alone or in combination of two or more different metal hydroxides.

The amount of (B) the metal hydroxide compounded in the present invention is 5 to 100 parts by weight per 100 parts by weight of the (A) thermoplastic polyester resin. If the amount of the metal hydroxide is less than 5 parts by weight, the dimensional stability of the resulting thermoplastic polyester resin composition is lowered. It is preferably 6 parts by weight or more, more preferably 9 parts by weight or more, and still more preferably 11 parts by weight or more. On the other hand, when the amount of the metal hydroxide compounded exceeds 100 parts by weight, the retention stability is lowered, and the molding stability of the obtained thermoplastic polyester resin composition is lowered. It is preferably 70 parts by weight or less, more preferably 50 parts by weight or less, and even more preferably 40 parts by weight or less.

The thermoplastic polyester resin composition of the present invention contains (C) a polyolefin resin and/or a styrenic resin in order to retain retention stability and molding stability while containing (B) a metal hydroxide.

The (C-1) polyolefin resin in the present invention is a thermoplastic resin obtained by polymerizing or copolymerizing olefins such as ethylene, propylene, butene, isoprene and pentene. Homopolymers such as 1-butene, poly-1-pentene, and polymethylpentene, ethylene/propylene copolymers, ethylene/propylene/non-conjugated diene copolymers, ethylene-butene-1 copolymers, ethylene/glycidyl methacrylate copolymers Polymer, ethylene/butene-1/glycidyl methacrylate copolymer, ethylene/propylene/glycidyl methacrylate copolymer, ethylene/octene-1/glycidyl methacrylate copolymer, ethylene/acrylate/glycidyl methacrylate copolymer, ethylene /maleic anhydride copolymer, ethylene/butene-1/maleic anhydride copolymer, ethylene/propylene/maleic anhydride copolymer, ethylene/acrylic acid ester/maleic anhydride copolymer and the like. From the viewpoint of mechanical properties and workability, polyethylene, polypropylene, ethylene-butene-1 copolymer, and ethylene/glycidyl methacrylate copolymer are preferred.

The (C-1) polyolefin resin in the present invention may be used alone or in combination of two or more different types of polyolefin resins.

The (C-1) polyolefin resin in the present invention preferably has a melt flow rate of 0.01 g/10 minutes or more from the viewpoint of suppressing aggregation in the thermoplastic polyester resin composition. More preferably, it is 0.03 g/10 minutes or more. From the viewpoint of further improving the mechanical strength, it is preferably 70 g/10 minutes or less. More preferably, it is 60 g/10 minutes or less. The melt flow rate of the polyolefin resin in the present invention is a value measured at a temperature of 190° C. according to ISO1133.

The (C-2) styrenic resin in the present invention includes polystyrene, AS resin (acrylonitrile/styrene copolymer) and rubber-modified styrenic resin. Specific examples of rubber-modified styrene resins include high-impact polystyrene (HIPS), ABS resin (acrylonitrile/butadiene/styrene copolymer), AAS resin (acrylonitrile/acrylic/styrene copolymer), and AES resin. (acrylonitrile/ethylene propylene/styrene copolymer), hydrogenated or unhydrogenated SBS resin (styrene/butadiene/styrene triblock copolymer) and hydrogenated or unhydrogenated SIS resin (styrene/isoprene/styrene triblock copolymer). polymer), SEBS resin (hydrogenated styrene/butadiene/styrene triblock copolymer), and the like. AS resin (acrylonitrile/styrene copolymer) is preferable from the viewpoint of mechanical properties and workability.

The (C-2) styrene resin used in the present invention preferably has an intrinsic viscosity [η] of 0.25 dl/g or more from the viewpoint of further improving mechanical properties. More preferably, it is 0.35 dl/g or more. From the viewpoint of suppressing aggregation in the thermoplastic polyester resin composition, the intrinsic viscosity [η] is preferably 5.00 dl/g or less. More preferably, it is 3.00 dl/g or less. In the present invention, the intrinsic viscosity of the styrenic resin is a value measured at 30° C. using methyl ethyl ketone as a solvent.

The (C) polyolefin resin and/or styrene resin in the present invention may be one of (C-1) polyolefin resin or (C-2) styrene resin, or two or more (C- 1) Polyolefin resin or (C-2) styrene resin may be used in combination, or one or more types of (C-1) polyolefin resin and (C-2) styrene resin may be used in combination. In order to improve the reactivity with (A) the thermoplastic polyester resin and (B) the metal hydroxide, it is preferable to use two or more (C) polyolefin resins and/or styrene resins.

The blending amount of (C) the polyolefin resin and/or the styrene resin in the present invention is 5 to 100 parts by weight per 100 parts by weight of the (A) thermoplastic polyester resin. If the blending amount of the polyolefin resin and/or the styrene resin is less than 5 parts by weight, the retention stability is lowered, and the molding stability of the resulting thermoplastic polyester resin composition is lowered. It is preferably 6 parts by weight or more, more preferably 9 parts by weight or more, and still more preferably 11 parts by weight or more. On the other hand, when the amount of the metal hydroxide compounded exceeds 100 parts by weight, the dimensional stability of the resulting thermoplastic polyester resin composition is lowered. It is preferably 70 parts by weight or less, more preferably 50 parts by weight or less, and even more preferably 40 parts by weight or less.

The compounding ratio (weight ratio) of (B) the metal hydroxide and (C) the polyolefin resin and/or the styrenic resin in the present invention takes a structure in which the (B) component is covered with the (C) component. Although there is no particular limitation as long as the rate of change in melt flow rate of the plastic polyester resin composition is expressed within a specific range, it is preferable that (B)/(C)=0.25-4. From the viewpoint of improving dimensional stability, (B)/(C)=0.5 or more is more preferable. On the other hand, from the viewpoint of molding stability, (B)/(C)=2 or less is more preferable.

The thermoplastic polyester resin composition of the present invention has a melt flow rate measured according to ISO 1133 under a temperature condition of (A) the melting point of the thermoplastic polyester resin + 50 ° C., with a residence time of 5 minutes and a value of 15 minutes. is 200% or less. When the melt flow rate change rate is within the above range, decomposition of (A) thermoplastic polyester resin by (B) metal hydroxide is suppressed, and the obtained thermoplastic polyester resin composition has excellent molding stability. and dimensional stability. If the melt flow rate change rate of the thermoplastic polyester resin composition of the present invention exceeds 200%, the molding stability of the resulting thermoplastic polyester resin composition deteriorates. It is preferably 180% or less, more preferably 150% or less, and still more preferably 100% or less. The minimum value of change in melt flow rate is 0%.

The rate of change of the melt flow rate of the thermoplastic polyester resin composition in the present invention is determined by measuring the melt flow rate after allowing the thermoplastic polyester resin composition to melt and stay for 5 minutes and 15 minutes in the cylinder of the measuring device. The difference between the melt flow rate of 5 minutes and the melt flow rate of 15 minutes of residence was divided by the melt flow rate of 5 minutes of residence, and the percentage of the value was obtained as the melt flow rate change rate. The rate of change (%) calculated here is an absolute value and was calculated as a positive value. The melt flow rate of the thermoplastic polyester resin composition in the present invention can be measured, for example, with a melt indexer manufactured by Toyo Seiki Co., Ltd.

The thermoplastic polyester resin composition of the present invention preferably further contains (D) an acidic phosphate. By blending the acidic phosphate, the surface of (B) the metal hydroxide is efficiently covered with the (C) polyolefin resin and / or styrene resin, so (A) heat during long-term melting retention Decomposition of the plastic polyester resin is suppressed.

The (D) acidic phosphoric acid ester in the present invention is a general term for partial ester compounds of alcohols and phosphoric acid, in which the hydrogen of phosphoric acid is partially substituted with an alkyl group, an aryl group, or the like, and has a hydroxyl group. is a compound. Specific examples include monomethyl acid phosphate, monoethyl acid phosphate, monoisopropyl acid phosphate, monobutyl acid phosphate, monolauryl acid phosphate, monostearyl acid phosphate, monododecyl acid phosphate, monobehenyl acid phosphate, dimethyl acid phosphate, and diethyl acid. phosphates, diisopropyl acid phosphate, dibutyl acid phosphate, lauryl acid phosphate, distearyl acid phosphate, didodecyl acid phosphate, dibehenyl acid phosphate, trimethyl acid phosphate, triethyl acid phosphate, and mixtures of said mono- and dialkyl acid phosphates , monoalkyl acid phosphates, dialkyl acid phosphates and trialkyl acid phosphates and mixtures of one or more of said compounds. Preferred are long chain alkyl acid phosphate compounds such as mixtures of monostearyl acid phosphate and distearyl acid phosphate. Commercially available products thereof include “ADEKA STAB” AX-71 manufactured by ADEKA Corporation.

As for the (D) acidic phosphate in the present invention, only one kind may be used, or two or more different kinds of acidic phosphate may be used in combination.

The content of (D) the acidic phosphate ester in the present invention is preferably 0.5 to 15 parts by weight per 100 parts by weight of the (A) thermoplastic polyester resin. When the amount of the acidic phosphate is 0.5 parts by weight or more, the molding stability of the obtained thermoplastic polyester resin composition is improved, which is preferable. It is more preferably 0.7 parts by weight or more, and still more preferably 1 part by weight or more. On the other hand, when the amount of the acidic phosphate is 15 parts by weight or less, the mechanical strength and low gas properties are excellent, which is preferable. It is more preferably 10 parts by weight or less, still more preferably 5 parts by weight or less.

The thermoplastic polyester resin composition of the present invention preferably further contains (E) glass fiber. By adding (E) glass fiber, the mechanical strength and heat resistance can be further improved.

(E) Specific examples of glass fibers include chopped strand type and roving type glass fibers, and silane coupling agents such as aminosilane compounds and epoxysilane compounds and/or urethane and acrylic acid/styrene copolymers. One or more of acrylic acid copolymers, maleic anhydride copolymers such as methyl acrylate/methyl methacrylate/maleic anhydride copolymers, vinyl acetate, bisphenol A diglycidyl ether, and novolac epoxy compounds A glass fiber treated with a sizing agent containing an epoxy compound of (1) or the like is preferably used. The glass fiber treated with a sizing agent containing an epoxy compound or the like has excellent reactivity with (A) the thermoplastic polyester resin, and the obtained thermoplastic polyester resin composition has excellent mechanical properties and heat resistance. preferable. A silane coupling agent and/or a sizing agent may be used by being mixed with the emulsion liquid. Also, the fiber diameter of the glass fiber is preferably in the range of 1 to 30 μm. From the viewpoint of the dispersibility of the glass fiber in the resin, the lower limit is preferably 5 μm. From the viewpoint of mechanical strength, the upper limit is preferably 15 μm. In addition, although the above-mentioned fiber cross section is usually circular, it is also possible to use glass fibers having arbitrary cross sections such as elliptical glass fibers, flat glass fibers, and cocoon-shaped glass fibers with arbitrary aspect ratios. It is characterized by improved fluidity and the ability to obtain molded products with little warpage.

The blending amount of (E) the glass fiber in the present invention is preferably 5 to 150 parts by weight per 100 parts by weight of the (A) thermoplastic polyester resin. (E) Adding 5 parts by weight or more of the glass fiber is preferable because the mechanical strength and heat resistance can be further improved. 10 parts by weight or more is more preferable, and 15 parts by weight or more is even more preferable. On the other hand, (E) adding 150 parts by weight or less of the glass fiber is preferable because the mechanical strength and fluidity can be further improved. 100 parts by weight or less is more preferable, and 90 parts by weight or less is even more preferable.

In the thermoplastic polyester resin composition of the present invention, glass flakes, kaolin, talc, mica, calcium carbonate, zinc oxide, magnesium oxide, aluminum oxide, magnesium oxide and aluminum oxide may be added as inorganic fillers other than the glass fiber. , finely divided silicic acid, aluminum silicate and silicon oxide. Thereby, dimensional stability, retention stability and the like can be further improved. Two or more inorganic fillers may be used in combination in the present invention.

The thermoplastic polyester resin composition of the present invention may contain thermoplastic resins other than the components (A) and (C) within a range that does not impair the object of the present invention. Shrinkage and toughness can be improved. Examples of thermoplastic resins other than components (A) and (C) include vinyl resins, polyamide resins, polyacetal resins, polyurethane resins, aromatic or aliphatic polyketone resins, polyether ether ketone resins, polyimide resins, heat Plastic starch resins, polyurethane resins, aromatic polycarbonate resins, polyarylate resins, polyphenylene sulfide resins, polyphenylene ether resins, polysulfone resins, polyethersulfone resins, phenoxy resins, polyetherimide resins, cellulose acetate resins, polyvinyl alcohol resins, etc. be able to. When a thermoplastic resin other than the components (A) and (C) is blended, the ratio of the component (A) or the component (C) is the highest among the thermoplastic resin species in the thermoplastic polyester resin composition. A large number is preferable.

The thermoplastic polyester resin composition of the present invention may contain a flame retardant within a range that does not impair the effects of the present invention. Examples of flame retardants include halogen flame retardants such as phosphorus flame retardants and brominated flame retardants, salts of triazine compounds with cyanuric acid or isocyanuric acid, silicone flame retardants and inorganic flame retardants. . You may mix|blend 2 or more types of these.

The blending amount of the flame retardant is preferably 1 to 50 parts by weight per 100 parts by weight of the thermoplastic polyester resin (A). From the viewpoint of flame retardancy, it is more preferably 5 parts by weight or more, and from the viewpoint of heat resistance, it is more preferably 40 parts by weight or less.

The thermoplastic polyester resin composition of the present invention can be blended with a release agent to improve the releasability from the mold during melt processing. Examples of the release agent include higher fatty acid ester-based waxes such as montanic acid and stearic acid, polyolefin-based waxes, and ethylene bis-stearamide-based waxes.

The content of the release agent is preferably 0.01 to 1 part by weight per 100 parts by weight of the thermoplastic polyester resin (A). From the viewpoint of releasability, it is more preferably 0.03 parts by weight or more, and from the viewpoint of heat resistance, it is more preferably 0.6 parts by weight or less.

The thermoplastic polyester resin composition of the present invention can further contain one or more of carbon black, titanium oxide, and pigments and dyes of various colors to provide various color toning and weather (light) resistance. and conductivity can be improved. Examples of carbon black include channel black, furnace black, acetylene black, anthracene black, soot, pine soot, and graphite. Carbon black having an average particle size of 500 nm or less and a dibutyl phthalate oil absorption of 50 to 400 cm ³ /100 g is preferably used. Titanium oxide having a crystal form such as rutile or anatase and having an average particle size of 5 μm or less is preferably used as titanium oxide.

These carbon black, titanium oxide and various color pigments and dyes may be treated with aluminum oxide, silicon oxide, zinc oxide, zirconium oxide, polyols, silane coupling agents and the like. In addition, in order to improve the dispersibility in the resin composition of the present invention and the handling property during production, it may be used as a mixed material obtained by melt blending or simply blending with various thermoplastic resins.

The blending amount of the pigment or dye is preferably 0.01 to 3 parts by weight per 100 parts by weight of the thermoplastic polyester resin (A). From the viewpoint of preventing uneven coloring, it is more preferably 0.03 parts by weight or more, and from the viewpoint of mechanical strength, it is more preferably 1 part by weight or less.

The thermoplastic polyester resin composition of the present invention may contain an antioxidant, a heat stabilizer, an ultraviolet absorber, a light stabilizer, a crystal nucleating agent, a plasticizer, a flame retardant auxiliary, as long as the objects of the present invention are not impaired. and one or more optional additives such as antistatic agents.

The thermoplastic polyester resin composition of the present invention can be obtained by melt-kneading the components (A) to (C) and, if necessary, components (D), (E) and other components.

The thermoplastic polyester resin composition of the present invention expresses the rate of change in melt flow rate within the range described above, and it is possible to control the reaction between the components (A) and (B) in order to achieve the effects of the present invention. is important. Specifically, the melt-kneading method for that purpose is to combine components (A) to (C), and optionally components (D), (E) and other additives together at a low temperature near the melting point of component (A). and a method of melt-kneading the components (B) and (C), and optionally the component (D) and other additives to obtain a first resin composition by melt-kneading, and the first resin composition and A method of melt-kneading the (A) component and, if necessary, the (E) component and other additives, and mixing the (B) to (D) components with a mixer or the like to coat the surface of the (B) component. A thermoplastic polyester resin composition can be obtained by a method of melt-kneading the treated powder with the component (A) and, if necessary, the component (E) and other additives.

In particular, the surface of the component (B) is easily covered with the component (C) and the decomposition of the component (A) is suppressed. A preferred method is to obtain a thermoplastic polyester resin composition by obtaining the first resin composition and melt-kneading the first resin composition and component (A). This method includes a method of melt-kneading the first resin composition as a master pellet containing components (B) to (D) at a high concentration and then melt-kneading it with the component (A); After the component (D) is fed from the main feeder and melt-kneaded, the component (A) is fed from the side feeder and melt-kneaded.

The thermoplastic polyester resin composition of the present invention is preferably molded after being pelletized. As a method of pelletizing, for example, a single screw extruder, a twin screw extruder, a triple screw extruder, a conical extruder and a kneader type kneader equipped with a “Unimelt” or “Darmage” type screw are used to form strands. A method of discharging in a shape and cutting with a strand cutter can be mentioned.

By melt-molding the thermoplastic polyester resin composition of the present invention, films, fibers, and other molded articles of various shapes can be obtained. Examples of melt molding methods include injection molding, extrusion molding and blow molding, and injection molding is particularly preferably used.

Injection molding methods include gas assist molding, two-color molding, sandwich molding, in-mold molding, insert molding, and injection press molding, in addition to ordinary injection molding methods, but any molding method is applicable. can.

The molded article of the present invention can be used as a molded article for machine mechanism parts, electrical parts, electronic parts, and automobile parts that take advantage of its excellent dimensional stability and molding stability. In addition, the molded article of the present invention is excellent in dimensional stability and molding stability, and is particularly useful for electrical and electronic parts.

Specific examples of machine mechanism parts, electric parts, electronic parts, and automobile parts include breakers, electromagnetic switches, focus cases, flyback transformers, moldings for fixing machines of copiers and printers, general household appliances, and office automation equipment. Equipment housings, variable capacitor case parts, various terminal boards, transformers, printed wiring boards, housings, terminal blocks, coil bobbins, connectors, relays, disk drive chassis, transformers, switch parts, outlet parts, motor parts, sockets, plugs , capacitors, various cases, resistors, electrical and electronic parts with metal terminals and conductors, computer-related parts, audio parts such as audio parts, lighting parts, telegraph equipment-related parts, telephone equipment-related parts, air-conditioner parts, VTRs and televisions, copier parts, facsimile parts, optical equipment parts, automotive ignition device parts, automotive connectors, and various automotive electrical components.

EXAMPLES Next, the effects of the thermoplastic polyester resin composition of the present invention will be specifically described by way of examples. Raw materials used in Examples and Comparative Examples are shown below. Here, % and parts all represent weight % and parts by weight, and "/" in the following resin names means copolymerization.

(A) Thermoplastic polyester resin <A-1> Polybutylene terephthalate resin: manufactured by Toray Industries, Inc., polybutylene terephthalate resin with MFR: 35 g/10 min (measured at 250°C and 1000 gf by a method conforming to ISO 1133) was used.
<A-2> Polyethylene terephthalate resin: A polyethylene terephthalate resin manufactured by Toray Industries, Inc. and having an MFR of 38 g/10 minutes (measured under conditions of 270° C. and 1000 gf according to ISO 1133) was used.

(B) Metal hydroxide <B-1> Surface-untreated magnesium hydroxide: Junmag Series 4N (average particle diameter = 4 µm) manufactured by Fimatech Co., Ltd. was used.
<B-2> Surface-treated magnesium hydroxide: "Kisuma" (registered trademark) 5E (average particle size = 0.9 µm) manufactured by Kyowa Chemical Industry Co., Ltd. was used.

(C) Polyolefin resin and/or styrene resin <C-1> Polyolefin resin: ethylene-butene-1 copolymer, "Tafmer" (registered trademark) A4085S manufactured by Mitsui Chemicals, Inc. was used. The melt flow rate was 4 g/10 minutes.
<C-2> AS resin (acrylonitrile/styrene copolymer): A bead-like vinyl copolymer was prepared by suspension polymerization of styrene and acrylonitrile. The weight ratio of each component was styrene/acrylonitrile=24/76 (parts by weight/parts by weight). The intrinsic viscosity measured at 30° C. in methyl ethyl ketone solvent was 0.52 dl/g.

(D) Acidic phosphate <D-1> Long-chain alkyl acid phosphate compound: "ADEKA STAB" (registered trademark) AX-71 manufactured by ADEKA Corporation was used.

(E) Glass fiber <E-1> Glass fiber: Glass fiber ECS03T-187 manufactured by Nippon Electric Glass Co., Ltd. was used.

[Measurement method of each characteristic]
In Examples and Comparative Examples, the properties were evaluated by the following measurement methods.

(1) Retention stability (rate of change in melt flow rate)
Using C501DOS manufactured by Toyo Seiki Co., Ltd., the thermoplastic polyester resin composition is melted and retained in a cylinder for 5 minutes according to ISO 1133 under the conditions of (A) the melting point of the thermoplastic polyester resin + 50 ° C. and a load of 1000 gf. After that, the melt flow rate was measured. Furthermore, after the thermoplastic polyester resin composition was melted and retained in the cylinder for 15 minutes, the melt flow rate was measured under the same conditions, and the difference between the melt flow rates of 5 minutes and 15 minutes of melt retention was determined by the melt retention of 5 minutes. The percentage of the value divided by the flow rate was obtained as the melt flow rate change rate (%). The rate of change (%) calculated here is an absolute value and was calculated as a positive value. It was judged that the smaller the rate of change in melt flow rate, the better the retention stability.

(2) Dimensional stability Using a NEX1000 injection molding machine manufactured by Nissei Plastic Industry Co., Ltd., when polybutylene terephthalate resin is used as the component (A), the molding temperature is 260 ° C. and the mold temperature is 80 ° C. , When polyethylene terephthalate resin is used as component (A), injection molding is performed at a molding temperature of 280°C, a mold temperature of 80°C, a total injection time and holding pressure time of 10 seconds, and a cooling time of 10 seconds. Under the conditions, a rectangular plate for dimensional stability evaluation of 80 mm long×80 mm wide×3 mm thick was obtained. The flow direction (MD) of the molten resin of the square plate for evaluation and the direction (TD) perpendicular to the flow direction of the molten resin are measured with a Nikon universal projector V20B, and the TD molding shrinkage rate (along the TD direction The average length of the test piece obtained/the mold dimension in the TD direction) and the MD molding shrinkage rate (the average length of the test piece obtained along the MD direction/the mold dimension in the MD direction) were determined. A difference in molding shrinkage (Δ(TD-MD)) was calculated from the following formula. The smaller the molding shrinkage difference, the better the dimensional stability.
Mold shrinkage rate difference (Δ (TD-MD)) = TD molding shrinkage rate - MD molding shrinkage rate

(3) Molding stability (tensile strength retention after melt retention)
Using a NEX1000 injection molding machine manufactured by Nissei Plastic Industry Co., Ltd., under the same injection molding conditions as in item (2) above, a molding cycle in which the resin composition has a melting residence time of 3 minutes in the cylinder ASTM D638 (2005) A test piece for tensile physical property evaluation of ASTM No. 1 dumbbell (1/8 inch thickness) was obtained. Further, a test piece for evaluating tensile physical properties after melt retention was obtained under the same conditions except that the molding cycle was such that the melt retention time of the resin composition in the cylinder was 10 minutes. Using the obtained test piece for evaluating tensile physical properties, the maximum tensile strength (tensile strength) was measured according to ASTM D638 (2005). The value was the average value of three measured values. From the tensile strength of 3 minutes and 10 minutes of melting retention, the tensile strength retention rate was determined by the following formula. It was judged that the higher the numerical value of the tensile strength retention rate, the better the molding stability of the material, and that the material with the tensile strength retention rate of 80% or more was particularly excellent in the molding stability.
Tensile strength retention (%) = (maximum tensile strength at 10 minutes of melt retention/maximum tensile strength at 3 minutes of melt retention) x 100

[Production Examples 1 to 7]
(B) a metal hydroxide, (C) a polyolefin resin and/or a styrenic resin, using a co-rotating vented twin-screw extruder (manufactured by Japan Steel Works, Ltd., TEX-30α) with a screw diameter of 30 mm and an L/D of 35. And (D) acidic phosphate ester was mixed in the composition shown in Table 1 and added from the main loading section of the twin-screw extruder. Melt-mixing was carried out under extrusion conditions of a kneading temperature of 250° C. and a screw rotation of 200 rpm, and the mixture was extruded in the form of strands, passed through a cooling bath, and pelletized with a strand cutter.

The obtained pellets were dried in a hot air dryer at a temperature of 50° C. for 6 hours, and then used for the following examples and comparative examples.

[Examples 1 to 11], [Comparative Examples 1 to 5]
Using a co-rotating vented twin-screw extruder with a screw diameter of 30 mm and L/D 35 (manufactured by Japan Steel Works, TEX-30α), (A) a thermoplastic polyester resin, (B) a metal hydroxide, (C) A polyolefin resin and/or a styrenic resin, (D) an acidic phosphate ester, and Production Examples 1 to 7 shown in Table 1 are mixed in the compositions shown in Tables 2 and 3, and the mixture is fed from the main loading section of the twin-screw extruder. added. The (E) fibrous reinforcing material was added by installing a side feeder between the main loading portion and the vent portion. Melt-mixing was performed under the extrusion conditions of the melt-kneading temperature and screw rotation of 200 rpm shown in Tables 2 and 3, and the mixture was extruded in strand form, passed through a cooling bath, and pelletized with a strand cutter.

The obtained pellets were dried in a hot air dryer at a temperature of 110° C. for 6 hours and then evaluated by the method described above. Tables 2 and 3 show the results.

From the comparison of Examples and Comparative Examples, (A) a thermoplastic polyester resin, (B) a metal hydroxide, and (C) a polyolefin resin and / or a styrenic resin were mixed in a specific range, and a specific retention stability was obtained. A material with excellent dimensional stability and molding stability was obtained.

Claims (6)

(A) 100 parts by weight of thermoplastic polyester resin, (B) 5 to 100 parts by weight of metal hydroxide, and (C) 5 to 100 parts by weight of polyolefin resin and/or styrene resin are blended. (A) Melt flow rate measured according to ISO 1133 under a temperature condition of the melting point of the thermoplastic polyester resin + 50 ° C. The rate of change between the value of 5 minutes and the value of 15 minutes is 200% or less. A thermoplastic polyester resin composition. 2. The thermoplastic polyester resin composition according to claim 1, further comprising 0.5 to 15 parts by weight of (D) an acidic phosphate compound with respect to 100 parts by weight of (A) the thermoplastic polyester resin. 3. The thermoplastic polyester resin composition according to claim 1 or 2, wherein (E) 5 to 150 parts by weight of glass fiber is blended with 100 parts by weight of (A) the thermoplastic polyester resin. A molded article obtained by injection molding the thermoplastic polyester resin composition according to any one of claims 1 to 3. 5. The molded article according to claim 4, wherein said molded article is used for electric and electronic parts. (B) the metal hydroxide, (C) the polyolefin resin and/or the styrenic resin, and (D) the acidic phosphoric acid ester compound are melt-kneaded to obtain a first resin composition, and then the first resin composition is obtained. and (A) the thermoplastic polyester resin are melt-kneaded.