JP2007169367A - Polyester resin composition and molded item - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester resin composition that is excellent in toughness, impact resistance and molding processability (flowability), particularly in heat shock resistance while retaining biodegradability. <P>SOLUTION: The polyester resin composition comprises 100 pts.wt. of the total of 1-99 pts.wt. of (A) an aromatic polyester resin and 1-99 pts.wt. of (B) an aliphatic polyester copolymer, and 0.5-40 pts.wt. of (C) an impact modifier, where the aromatic polyester resin (A) has a terminal carboxy group concentration of at most 50 eq/ton and the aliphatic polyester copolymer (B) comprises 0-30 mol% of an aliphatic oxycarboxylic acid unit, 35-50 mol% of an aliphatic unit and/or an alicyclic diol unit and 35-50 mol% of an aliphatic dicarboxylic acid unit. A molded item obtained by molding the resin composition is also provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polyester resin composition and a molded body. Specifically, the polyester resin composition is excellent in toughness, impact resistance and molding processability, particularly improved in heat shock resistance and biodegradability. The present invention relates to a polyester resin composition suitable as a material for parts such as electronic devices and machines, and a molded body formed by molding the resin composition.

  Aromatic polyester resins as engineering plastics, especially polybutylene terephthalate resins, are superior in ease of molding, mechanical strength, heat resistance, chemical resistance, and other physical and chemical properties. It is widely used as a material for various parts in fields such as electrical / electronic equipment and precision equipment. As the application field of aromatic polyester resins expands, further improvements in toughness and impact resistance are required, and molding processability (fluidity) is increasing as moldings become thinner and larger in recent years. There has been a strong demand for improvements. Furthermore, from the viewpoint of environmental conservation in recent years, there has been a demand for performance such as ease of volume reduction and fine graining at the time of disposal of molded products, and biodegradability. In order to satisfy these requirements, various resin compositions in which an aliphatic polyester resin is blended with an aromatic polyester resin have been proposed.

  For example, Patent Document 1 discloses a resin composition comprising a polymer having an aliphatic ester structure and an aromatic group-containing polyester resin. In particular, an aliphatic polyester polycarbonate resin is used as the polymer having an aliphatic ester structure. It is described that a resin composition that exhibits biodegradability and has high tear strength can be obtained by use. Patent Document 2 discloses that a resin composition obtained by adding a specific amount of a condensed polymer having an aromatic ring to an aliphatic polyester has improved crystallization speed and excellent strand cutting properties. Yes.

However, the resin compositions disclosed in Patent Documents 1 and 2 are still insufficient in terms of mechanical properties, molding processability (fluidity) and heat shock resistance, and the physical properties of the aromatic polyester are No attention has been paid to the influence on these characteristics.

  In addition, since polybutylene terephthalate resin is a resin having a balanced physical property, it is also known that it is insert-molded together with a metal or an inorganic solid. For example, Patent Document 3 discloses an insert molded product obtained by insert molding a resin composition composed of a polybutylene terephthalate resin and an acrylic rubber, and a metal as an insert molded product with improved heat shock resistance. ing. However, the method disclosed in Patent Document 3 relates to a thick molded product, and it cannot be said that the heat shock property in a thin molded product having a thickness of about 1 mm is sufficient.

Therefore, it is hoped to develop a reinforced polyester resin composition that retains biodegradability, has excellent mechanical properties and molding processability (fluidity), has excellent heat shock properties, and has excellent overall performance. It was rare.
JP 2004-18842 A JP 2005-133003 A JP-A 63-3055

The present invention has been made in view of such circumstances, and its purpose is to maintain biodegradability and to be excellent in toughness, impact resistance and molding processability (fluidity), and in particular, heat shock resistance. It is providing the polyester resin composition which is excellent in.

  As a result of intensive studies, the present inventors have found that the terminal carboxyl group concentration of the aromatic polyester resin affects each of the above-described properties for the resin composition containing the aromatic polyester resin and the aliphatic polyester copolymer. I found out. Then, the inventors have reached the present invention, knowing that the above object can be achieved by using an aromatic polyester resin having a terminal carboxyl group concentration of a specific value or less and containing an impact resistance improver.

That is, the first gist of the present invention is that (A) 1 to 99 parts by weight of an aromatic polyester resin and (B) 1 to 99 parts by weight of an aliphatic polyester copolymer are combined with (C ) A polyester resin composition containing 0.5 to 40 parts by weight of an impact resistance improver, wherein the (A) aromatic polyester resin has a terminal carboxyl group concentration of 50 eq / ton or less, and the (B) fat The aliphatic polyester copolymer contains 0 to 30 mol% of an aliphatic oxycarboxylic acid unit represented by the following formula (I) and 35 aliphatic and / or alicyclic diol units represented by the following formula (II). To 50 mol%, and 35 to 35 aliphatic dicarboxylic acid units represented by the following formula (III):
It exists in the polyester resin composition characterized by including 50 mol%.

  The second gist of the present invention resides in a molded body obtained by molding the polyester resin composition of the first gist.

  The polyester resin composition of the present invention retains biodegradability and is excellent in toughness, impact resistance and molding processability (fluidity), especially improved heat shock resistance, and a comprehensively balanced performance. Therefore, it is expected as an engineering plastic material that can cope with the environment.

  In particular, it is expected to be used as various structural materials that require impact resistance and heat shock resistance. Specifically, aircraft, rockets, artificial satellites and other aerospace equipment, railways, boats, automobiles, Structural materials, outer panels and pressure members of transport equipment such as motorcycles and bicycles; Housings and internal precision parts for electrical and electronic equipment; Various office supplies such as writing utensils, desks and chairs, and daily necessaries including various resin structures For example, it can be suitably used.

  Hereinafter, the present invention will be described in detail. However, the description of the constituent elements described below is a representative example of embodiments of the present invention, and the present invention is not limited to these contents.

(A) Aromatic polyester resin First, the (A) aromatic polyester resin used in the present invention will be described. The aromatic polyester resin is a polycondensate of an aromatic dicarboxylic acid or a derivative thereof and a diol. As the raw material aromatic dicarboxylic acid or derivative thereof, terephthalic acid or its lower alkyl ester is mainly used, but phthalic acid, isophthalic acid, 4,4′-diphenyldicarboxylic acid, 4,4′-diphenylether dicarboxylic acid. 4,4′-benzophenone dicarboxylic acid, 4,4′-diphenoxyethanedicarboxylic acid, 4,4′-diphenylsulfone dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, or a lower alkyl ester thereof, or one or two of them You may use the above together.

Examples of the diol to be reacted with the aromatic dicarboxylic acid or its derivative include ethylene glycol, 1,4-butanediol, polyethylene glycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol, polypropylene glycol, polytetra Methylene glycol, dibutylene glycol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, aliphatic diols such as 1,8-octanediol, 1,2-cyclohexanediol, 1,4-cyclohexanediol , 1,1-cyclohexanedimethylol, 1,4-cyclohexanedimethylol and other alicyclic diols, xylylene glycol, 4,4′-dihydroxybiphenyl, 2,2-bis (4-hydroxyphenyl) propane, bis ( 4 Aromatic diols such as -hydroxyphenyl) sulfone are mentioned, and ethylene glycol or 1,4-butanediol is preferred.

  Furthermore, as a part of the dicarboxylic acid and diol, hydroxy such as lactic acid, glycolic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 6-hydroxy-2-naphthalenecarboxylic acid, p-β-hydroxyethoxybenzoic acid, etc. Monofunctional components such as carboxylic acid, alkoxycarboxylic acid, stearyl alcohol, benzyl alcohol, stearic acid, benzoic acid, t-butylbenzoic acid, benzoylbenzoic acid, tricarbaric acid, trimellitic acid, trimesic acid, pyromellitic acid, Trifunctional or higher polyfunctional components such as gallic acid, trimethylolethane, trimethylolpropane, glycerol, pentaerythritol and the like can be used.

  The aromatic polyester resin (A) used in the present invention is preferably a polyethylene terephthalate resin (hereinafter sometimes referred to as PET resin) or a polybutylene terephthalate resin (hereinafter sometimes referred to as PBT resin). A PBT resin having moderate mechanical strength is most preferable. Here, the PBT resin is a component (terephthalic acid component) in which 50% by weight or more of all dicarboxylic acid components are derived from terephthalic acid or a derivative thereof, and 50% by weight or more of all diol components are converted to 1,4-butanediol. Polyesters composed of derived components are preferred. Among them, the ratio of the terephthalic acid component to the total dicarboxylic acid component is preferably 80 mol% or more, and more preferably 95 mol% or more. Moreover, 80 mol% or more is preferable and, as for the ratio of the 1, 4- butanediol component with respect to all the diol components, 95 mol% or more is still more preferable.

The present invention is characterized in that the terminal carboxyl group concentration of (A) the aromatic polyester resin, particularly the PBT resin, is 50 eq / ton or less. Thereby, compatibility with (A) aromatic polyester resin and (B) aliphatic polyester copolymer which will be described later can be moderately increased, the hydrolysis resistance of the resin composition is remarkably enhanced, and heat shock resistance is also achieved. Can be improved. The terminal carboxyl group concentration is 38 eq / ton or less, further 30 e.
It is preferably q / ton or less, particularly 25 eq / ton or less. The terminal carboxyl group concentration can be determined by dissolving (A) the aromatic polyester resin in an organic solvent and titrating with an alkali hydroxide solution.

  In the aromatic polyester resin (A) of the present invention, the content of the titanium compound is usually 300 ppm (weight ratio) or less in terms of titanium atoms, among which 150 ppm or less, more preferably 70 ppm or less, and particularly 40 ppm or less. preferable. On the other hand, the lower limit is 10 ppm or more, preferably 12 ppm or more, more preferably 15 ppm or more, and particularly preferably 20 ppm or more. If the content exceeds 300 ppm, the residence thermal stability and hydrolysis resistance of the resin composition may be reduced, or transesterification with the aliphatic polyester copolymer may proceed. The metal content of the titanium atom can be measured using a method such as atomic emission, atomic absorption, Inductively Coupled Plasma (ICP) after recovering the metal in the polymer by a method such as wet ashing. The titanium compound is usually mixed in the resin by leaving the catalyst used in the process of producing the (A) aromatic polyester resin. Therefore, the amount of titanium compound in the resin can be adjusted by adjusting the amount of titanium catalyst used.

The intrinsic viscosity of the PBT resin was measured using a mixed solvent of 1,1,2,2-tetrachloroethane / phenol = 1/1 (weight cost) at a solution concentration of 0.5 g / dl at 30 ° C. Usually, it is 0.5-3 dl / g, Preferably it is 0.6-2 dl / g, More preferably, it is the range of 0.7-1.5 dl / g. If the intrinsic viscosity is less than 0.5 dl / g, the mechanical strength may be insufficient. On the other hand, if the intrinsic viscosity is more than 3 dl / g, molding may be difficult.
Moreover, the intrinsic viscosity of PET resin is 0.4-3 dl / g normally, Preferably it is 0.5-1.5 dl / g, More preferably, it is the range of 0.6-1.0 dl / g. In addition, you may adjust so that an intrinsic viscosity may become the said range by using together 2 or more types of PBT resin and PET resin from which intrinsic viscosity differs.

  Furthermore, (A) the amount of residual tetrahydrofuran in the aromatic polyester resin, particularly PBT resin, is usually 800 ppm (weight ratio) or less, but 300 ppm (weight ratio) or less, more preferably 250 ppm (weight ratio) or less, Is preferably 200 ppm or less. The amount of the remaining tetrahydrofuran can be determined by immersing the resin pellet in water and treating it at 120 ° C. for 6 hours, and quantifying the amount of tetrahydrofuran eluted in water by gas chromatography. By setting the residual tetrahydrofuran amount to 300 ppm (weight ratio) or less, even when a molded product obtained from the resin composition of the present invention is used at a high temperature, the generation of gas such as tetrahydrofuran is small, and corrosion of electrical contacts is caused. Therefore, it can be suitably used for electrical / electronic components having electrical contacts such as relay components.

  The lower limit of the residual tetrahydrofuran amount is not particularly limited, but is usually about 50 ppm (weight ratio). A smaller amount of residual tetrahydrofuran tends to reduce the generation of organic gas, but the remaining amount and the amount of gas generated are not necessarily proportional. Further, as described in JP-A-8-209004, the presence of a small amount of tetrahydrofuran is also expected to suppress the corrosion of electrical contacts.

  The (A) aromatic polyester resin having a low terminal carboxyl group concentration used in the present invention may be either a method of melt polymerizing an aromatic dicarboxylic acid or a derivative thereof and a diol, or a method of further solid-phase polymerization after a melt polymerization reaction. It can be produced, and may be either a continuous process or a batch process. Among these methods, the melt polymerization method by the continuous method in which the raw material supply, the esterification reaction, and the subsequent polycondensation reaction are continuously produced more easily produces an aromatic polyester resin having a low terminal carboxyl group concentration. It is preferable in that it can be performed.

  As the melt polymerization method by a continuous method, for example, a dicarboxylic acid component and a diol component are preferably used at 150 to 280 ° C., more preferably in the presence of an esterification reaction catalyst in one or a plurality of esterification reaction vessels. Is a continuous esterification reaction at a temperature of 180 to 265 ° C., preferably 6.67 to 133 kPa, more preferably 9.33 to 105 kPa, with stirring for 2 to 5 hours. Subsequently, the oligomer which is the obtained esterification reaction product is transferred to a polycondensation reaction tank, and preferably in the presence of a polycondensation reaction catalyst in one or a plurality of polycondensation reaction tanks, preferably 210 to 280 ° C. The polycondensation reaction can be carried out continuously for 2 to 5 hours with stirring under a reduced pressure of 220 to 265 ° C., preferably 26.7 kPa or less, more preferably 20 kPa or less. The aromatic polyester resin such as PBT resin obtained by the polycondensation reaction is transferred from the bottom of the polycondensation reaction tank to a polymer extraction die and extracted in the form of a strand, and while being cooled with water or after being cooled with water, the pelletizer is used. Cut into pellets.

  The (A) aromatic polyester resin having a low terminal carboxyl group concentration used in the present invention can also be produced by performing solid phase polymerization after melt polymerization. For example, it can also be produced by melt polymerization such as batch method, transesterification, or esterification and polycondensation to obtain a polyester resin having a relatively high intrinsic viscosity, followed by solid phase polymerization. It is.

  (A) In the esterification reaction in the production of an aromatic polyester resin, for example, an esterification reaction catalyst such as a titanium compound, a tin compound, a magnesium compound, or a calcium compound can be used, and among these, a titanium compound is preferable. Used for. Examples of the titanium compound include titanium alcoholates such as tetramethyl titanate, tetraisopropyl titanate, and tetrabutyl titanate, and titanium phenolates such as tetraphenyl titanate.

  (A) In the polycondensation reaction in the production of the aromatic polyester resin, a polycondensation reaction catalyst such as an antimony compound such as antimony trioxide or a germanium compound such as germanium dioxide or germanium tetroxide can be used. .

  In the esterification reaction and / or polycondensation reaction described above, in addition to the above-described catalyst, orthophosphoric acid, phosphorous acid, hypophosphorous acid, polyphosphoric acid, or phosphorus compounds such as esters and metal salts thereof, water Reaction aids such as alkali metal or alkaline earth metal compounds such as sodium oxide, sodium benzoate, magnesium acetate, calcium acetate, 2,6-di-t-butyl-4-octylphenol, pentaerythrityl tetrakis [3- Phenol compounds such as (3 ′, 5′-t-butyl-4′-hydroxyphenyl) propionate], dilauryl-3,3′-thiodipropionate, pentaerythrityltetrakis (3-laurylthiodipropionate), etc. Thioether compounds, triphenyl phosphite, tris (nonylphenyl) phosphite, Antioxidants such as phosphorus compounds such as bis (2,4-di-t-butylphenyl) phosphite, paraffin wax, microcrystalline wax, polyethylene wax, long chain fatty acids such as montanic acid and montanic acid ester, or esters thereof, A release agent such as silicone oil can be present.

(B) Aliphatic polyester copolymer Next, the (B) aliphatic polyester copolymer used in the present invention will be described. (B) The aliphatic polyester copolymer is a copolymer containing the units represented by the following (I), (II) and (III) in predetermined mol%, and an aliphatic oxy corresponding to each unit. It can be produced by copolymerizing a predetermined amount of carboxylic acid, aliphatic and / or alicyclic diol, and aliphatic dicarboxylic acid. The number average molecular weight of the (B) copolymer is usually 10,000 to 200,000, preferably 30,000 to 100,000.

The aliphatic oxycarboxylic acid unit represented by the formula (I) is composed of one hydroxyl group and a carboxyl group in the molecule represented by HO—R ¹ —COOH (R ¹ represents a divalent aliphatic hydrocarbon group). It is obtained by using an aliphatic oxycarboxylic acid having a derivative thereof or a derivative thereof (cyclic monomer, cyclic dimer, anhydride, ester, etc.). As the aliphatic oxycarboxylic acid, those in which R ¹ is a divalent alkylidene group having 1 to 20 carbon atoms or an alkylene group are preferable. Furthermore, an α-oxycarboxylic acid represented by the following formula (I-1) is: preferable.

（式中、ｎは０又は１〜１０の整数を示す。）

(In the formula, n represents 0 or an integer of 1 to 10.)

  N in the formula (I-1) is 0 or an integer of 1 to 10, preferably 0 or an integer of 1 to 5. Specific examples of the oxycarboxylic acid of the formula (I-1) include glycolic acid, L-lactic acid, D-lactic acid, D, L-lactic acid, 2-hydroxy-n-butyric acid, 2-hydroxy-3-methyl-n. -Butyric acid, 2-hydroxy-3,3-dimethyl-n-butyric acid, 3-hydroxy-n-butyric acid, 4-hydroxy-n-butyric acid, 2-hydroxy-n-valeric acid, 3-hydroxy-n-valeric acid 4-hydroxy-n-valeric acid, 5-hydroxy-n-valeric acid, 2-hydroxy-n-caproic acid, 2-hydroxy-i-caproic acid, 3-hydroxy-n-caproic acid, 4-hydroxy- Examples include n-caproic acid, 5-hydroxy-n-caproic acid, and 6-hydroxy-n-caproic acid. Examples of the oxycarboxylic acid derivative include lactones such as propiolactone, butyrolactone, valerolactone, caprolactone, and laurolactone. Of these oxycarboxylic acids, preferred is lactic acid or glycolic acid, and particularly preferred is lactic acid. Lactic acid is particularly prominent in increasing the polymerization rate during the production of the polyester copolymer, and is easily available. Lactic acid is usually available in the form of a 30-95% by weight aqueous solution.

The aliphatic or alicyclic diol corresponding to the diol unit of the formula (II) is a diol represented by HO—R ² —OH (R ² represents a divalent aliphatic or alicyclic hydrocarbon). is there. In the formula (II), the divalent aliphatic hydrocarbon group represented by R ² is preferably a linear alkylene group, and the carbon number thereof is usually 2 to 10, preferably 3 to 10, and more preferably. Is 4-6. Examples of the alicyclic hydrocarbon group represented by R ^2, preferably a cycloalkylene group, the number of carbon is usually 3-10, preferably 4-6.

Specific examples of the aliphatic or alicyclic diol as described above include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,2-butanediol, 1,5-pentanediol, 1, 6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol, 1,18-octadecanediol, 1,2 -Cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethylol, 1,4-cyclohexanedimethylol and the like. These can be used as a mixture of two or more, for example, aliphatic diol and alicyclic diol. Among the above diols, ethylene glycol, 1,3-propanediol, and 1,4-butanediol are preferable from the viewpoint of physical properties of the polyester resin composition, and more preferably 1,3-propane. Diols and 1,4-butanediol, particularly 1,4-butanediol are preferred.

The aliphatic dicarboxylic acid corresponding to the aliphatic dicarboxylic acid unit of the formula (III) or a derivative thereof is represented by HOOC-R ³ —COOH (R ³ represents a direct bond or a divalent aliphatic hydrocarbon group). Dicarboxylic acid, its lower alcohol ester or acid anhydride. In the formula, R ³ is preferably a direct bond or a linear alkylene group, and the linear alkylene usually has 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms. Examples of the carboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecadicarboxylic acid, dodecadicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, dimer acid and hydrogenated product thereof, hexahydrophthalic acid, hexahydroisophthalic acid, hexahydroterephthalic acid and the like. Examples of the lower alcohol ester of dicarboxylic acid include esters of aliphatic alcohols having about 1 to 4 carbon atoms such as dimethyl ester, diethyl ester, and dibutyl ester. Examples of acid anhydrides include succinic anhydride and anhydrous adipic acid. Etc. These can also be used as a mixture of two or more. Among these, succinic acid and adipic acid are preferable and succinic acid is most preferable from the viewpoint of physical properties of the polyester resin composition.

  Part of the dicarboxylic acid component which is a component of the (B) aliphatic polyester copolymer of the present invention may be copolymerized with an aromatic dicarboxylic acid. In this case, the ratio of the aromatic dicarboxylic acid to the total dicarboxylic acid is preferably 60 mol% or less, more preferably 50 mol% or less, and still more preferably 30 mol% or less.

The ratio of each unit in the aliphatic polyester copolymer used in the present invention is as follows. That is, the unit of the formula (I) is 0 to 30 mol%, and the unit of the formula (II) and (III) is 35 to 50 mol%, preferably 40 to 49.75 mol%, more preferably 45 Although selected from the range of ˜49.5 mol%, the proportions of units of formula (II) and formula (III) are usually substantially equal. Here, the fact that the proportion of both is substantially equal means that the difference between the proportions of the two is usually within 3 mol%, and further within 2 mol%. In addition, when using a mixture of an aliphatic diol and an alicyclic diol as the diol corresponding to the diol unit of the formula (II), the total content of both may be within the above range.

  Further, the unit of the formula (I) is an arbitrary unit, but it is preferable to include it as an essential unit, and the ratio in that case is usually 0.02 to 30 mol%, preferably 0.5 to 20 mol%, More preferably, it is the range of 1-10 mol%. If the number of units of formula (I) is too small, the biodegradability effect of the resulting copolymer will be small, and if it is too large, the crystallinity of the resulting copolymer will be lost and molding will be difficult. It may not be preferable.

The aliphatic polyester copolymer in the present invention is prepared by reacting a diol and a dicarboxylic acid corresponding to the units (II) and (III) or a derivative thereof as described in, for example, JP-A-8-239461. When the aliphatic polyester is produced, the aliphatic oxycarboxylic acid corresponding to the unit of the formula (I) can be produced by a copolymerization method so that the amount is in the above-mentioned predetermined range.

The amount of diol corresponding to formula (II) is substantially equimolar to the dicarboxylic acid or derivative thereof (value based on the amount of dicarboxylic acid) corresponding to formula (III), but it is distilled during the esterification reaction. Therefore, it is usually used in an excess of 1 to 20 mol%. The amount of the aliphatic oxycarboxylic acid corresponding to the formula (I) is the dicarboxylic acid corresponding to the formula (III) or its derivative 10
It is 0-60 mol normally with respect to 0 mol, Preferably it is 0.04-60 mol, More preferably, it is 1-40 mol, Most preferably, it is 2-20 mol.

  The addition time of the aliphatic oxycarboxylic acid is not particularly limited as long as it is before the polycondensation reaction, but a method of adding at the same time as the catalyst at the time of raw material charging, a method of adding the catalyst by dissolving it in the oxycarboxylic acid solution in advance, etc. are adopted. I can do it.

(B) It is preferable to use a polymerization catalyst in the production of the aliphatic polyester copolymer. Although it does not specifically limit as a polymerization catalyst, A germanium compound, especially germanium oxide are suitable. The usage-amount of a polymerization catalyst is 0.001 to 3 weight% normally with respect to the whole monomer amount to be used, Preferably it is 0.005 to 1.5 weight%.
The polymerization reaction temperature is usually 150 to 260 ° C., preferably 180 to 230 ° C., the reaction time is usually 2 hours or more, preferably 4 to 15 hours, and the reaction pressure is usually 10 mmHg or less, preferably 2 mmHg or less.

  (B) The intrinsic viscosity of the aliphatic polyester copolymer is a mixed solvent of 1,1,2,2-tetrachloroethane / phenol = 1/1 (weight cost), and the solution concentration is 0.5 g / 30 ° C. at 30 ° C. The value measured by dl is usually in the range of 0.5 to 4 dl / g, preferably 0.8 to 3 dl / g, more preferably 1 to 2.5 dl / g. If the intrinsic viscosity is less than 0.5 dl / g, the mechanical strength may be insufficient. On the other hand, if the intrinsic viscosity is greater than 4 dl / g, molding may be difficult.

  The content of the (B) aliphatic polyester copolymer in the resin composition of the present invention is not particularly limited, but is usually 1 to 500 parts by weight, preferably 100 parts by weight of the (A) aromatic polyester resin. Is 5 to 300 parts by weight, more preferably 10 to 150 parts by weight, and particularly preferably 15 to 90 parts by weight. When the amount of the (B) copolymer is too small, the biodegradability of the resulting resin composition may be insufficient. On the other hand, when the amount is too large, the impact resistance of the resulting resin composition may be insufficient. In some cases, improvement of mechanical properties such as property is insufficient.

In addition to the structural units (I) to (III), other copolymer components can be introduced into the (B) aliphatic polyester copolymer as long as the effects of the present invention are not impaired. Other raw materials for the copolymerization component include aromatic oxycarboxylic acids such as hydroxybenzoic acid, aromatic diols such as bisphenol A, aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, trimethylolpropane, glycerin and the like. And polyhydric oxycarboxylic acids such as monohydric alcohols and malic acid.

(C) Impact resistance improver The polyester resin composition of the present invention is characterized by containing (C) an impact resistance improver in addition to the resin component described above. Thereby, impact values, such as an Izod impact value of a molded article, a Charpy impact value, and a surface impact value, and heat shock resistance can be improved. (C) Examples of the impact resistance improver include thermoplastic elastomers and core-shell polymers.

  A thermoplastic elastomer is a solid having a rubber-like elasticity at room temperature, but its viscosity decreases when heated. Therefore, it is a general term for polymer substances having the property of being melt-mixable with a thermoplastic polyester resin. Although it does not restrict | limit especially as a kind of thermoplastic elastomer, For example, an olefin type, an acrylic type, a styrene type, a polyester type, a polyamide type, a urethane type, a butadiene type, a silicone type etc. are mentioned.

  Although it does not specifically limit as an olefin-type elastomer, It is a copolymer which has ethylene and / or propylene as a main component, Specifically, an ethylene-propylene copolymer, an ethylene-butene copolymer, an ethylene-octene copolymer An ethylene-propylene-butene copolymer, an ethylene-propylene-diene copolymer, an ethylene-ethyl acrylate copolymer, an ethylene-vinyl acetate copolymer, an ethylene-glycidyl methacrylate copolymer, and the like are preferable.

  Among olefin elastomers, (a-1) an ethylene-unsaturated carboxylic acid copolymer or an alkyl ester copolymer thereof, or (a-2) a glycidyl ester of an α-olefin and an α, β-unsaturated acid. A branched or cross-linked olefin copolymer and (b) one or more of a polymer or a copolymer mainly composed of repeating units represented by the following general formula (1) at least at one point A graft copolymer having a structure can be suitably used. Such a graft copolymer obtains a significant impact resistance improving effect that cannot be obtained by simply blending (a-1), (a-2) or (b) alone. Here, the ratio of (a-1) or (a-2) and (b) for constituting the graft copolymer is usually (a-1) / (a-2) :( b) 95: 5 to 5:95 (weight ratio), preferably 80:20 to 20:80.

（一般式（１）中、Ｒは水素原子又は低級アルキル基を表し、Ｘは、カルボキシル基、アルコキシカルボニル基、アリーロキシカルボニル基、シアノ基から選ばれる１種又は２種以上の基を表す。）

(In general formula (1), R represents a hydrogen atom or a lower alkyl group, and X represents one or more groups selected from a carboxyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, and a cyano group. )

In general formula (1), when X is an alkoxycarbonyl group, the alkoxy group is usually an alkoxy group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, specifically, —COOCH ₃ , —COOC. _{2 H 5, -COOC 4 H 9} , -COOCH 2 CH (C 2 H 5) C 4 H 9, -COOC 6 H 5, include -CN, or the like. Moreover, a phenoxy group is mentioned as an aryloxy group in case X is an aryloxycarbonyl group.

  The graft copolymer of (a-1) or (a-2) and (b) described above is particularly effective in improving the thermal shock characteristics, and is particularly suitable as the impact resistance-imparting agent of the present invention. Among these, specific examples of (a-1) ethylene-unsaturated carboxylic acid copolymer and alkyl ester copolymer thereof include ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-acrylic acid. -Copolymers, such as an ethyl acrylate copolymer and an ethylene-ethyl acrylate copolymer, are mentioned, Furthermore, these copolymers can also be used in mixture.

  (A-2) The α-olefin, which is one monomer constituting the olefin copolymer, includes ethylene, propylene, butene-1, and the like, and ethylene is preferably used. Moreover, as the glycidyl ester of α, β-unsaturated acid which is another monomer, a compound represented by the following general formula (2) is preferable.

（一般式（２）中、Ｒ’は水素原子または低級アルキル基を示す。）
上記一般式（２）で表されるα，β−不飽和酸のグリシジルエステルとしては、アクリル酸グリシジルエステル、メタクリル酸グリシジルエステル、エタクリル酸グリシジルエステル等が挙げられるが、特にメタクリル酸グリシジルエステルが好ましく用いられる。

(In general formula (2), R ′ represents a hydrogen atom or a lower alkyl group.)
Examples of the glycidyl ester of α, β-unsaturated acid represented by the general formula (2) include glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, and the like, and glycidyl methacrylate is particularly preferable. Used.

  (A-2) The olefin copolymer can be obtained by copolymerizing an α-olefin and a glycidyl ester of an α, β-unsaturated acid by a well-known radical polymerization reaction. The composition of (a-2) is preferably 70 to 99% by weight of α-olefin units and 30 to 1% by weight of glycidyl ester of α, β-unsaturated acid.

  Next, as the polymer or copolymer (b) mainly composed of the repeating unit represented by the general formula (1), for example, polymethyl methacrylate, polyethyl acrylate, polybutyl acrylate, polyacryl Acid-2-ethylhexyl, polystyrene, polyacrylonitrile, acrylonitrile-styrene copolymer, butyl acrylate-methyl methacrylate copolymer, butyl acrylate-styrene copolymer, and the like, particularly preferably butyl acrylate- It is a methyl methacrylate copolymer. These polymers or copolymers (b) can be produced by radical polymerization of the corresponding vinyl monomers.

  In addition, the method for producing the graft copolymer used in the present invention may be any of generally known methods such as chain transfer method and ionizing radiation irradiation method, but the most preferable method is in the main chain component particles. The grafting precursor obtained by copolymerizing the monomer of the component (b) which is the polymer or copolymer described above and the radical (co) polymerizable organic peroxide is melt-kneaded, It is a method of manufacturing by grafting reaction. This method is preferable in that the efficiency of the performance is more effective because the grafting efficiency is high and secondary aggregation due to heat does not occur.

  An acrylic elastomer, which is a thermoplastic elastomer, is a rubber-like elastic body obtained by a polymerization reaction of an acrylic ester or a copolymerization reaction mainly composed of an acrylic ester. Typically, an acrylic ester such as butyl acrylate Examples thereof include rubber-like polymers obtained by graft polymerizing a graft-polymerizable monomer such as methyl methacrylate with a polymer obtained by polymerizing a small amount of a cross-linkable monomer such as butylene diacrylate.

  Examples of the acrylic ester include methyl acrylate, ethyl acrylate, propyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate and the like in addition to butyl acrylate. Moreover, as the crosslinkable monomer, in addition to butylene diacrylate, polyols such as butylene dimethacrylate and trimethylolpropane trimethacrylate and esters of acrylic acid or methacrylic acid, vinyl compounds such as divinylbenzene, vinyl acrylate and vinyl methacrylate, Examples include allyl compounds such as allyl acrylate, allyl methacrylate, diallyl malate, diallyl fumarate, diallyl itaconate, monoallyl malate, monoallyl fumarate, triallyl cyanurate, and the like.

  Examples of the graft polymerizable monomer include, in addition to methyl methacrylate, methacrylic acid esters such as ethyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, and lauryl methacrylate, styrene, and acrylonitrile. A part of this graft polymerizable monomer can be copolymerized by coexisting when the polymer is produced by polymerizing the acrylate ester and the crosslinkable monomer.

  Examples of the styrene elastomer include a block copolymer comprising a polymer block A mainly composed of a vinyl aromatic compound such as styrene and a polymer block B mainly composed of an unhydrogenated and / or hydrogenated conjugated diene compound. Can be mentioned. Examples of the vinyl aromatic compound constituting the block copolymer include styrene, α-methylstyrene, vinyltoluene, p-tertiary butylstyrene, divinylbenzene, p-methylstyrene, 1,1-diphenylstyrene, and the like. One type or two or more types can be selected, and among them, styrene is preferable. Examples of the conjugated diene compound include butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, pyrylene, 3-butyl-1,3-octadiene, phenyl-1,3- One or more selected from butadiene and the like are selected, and butadiene, isoprene and combinations thereof are particularly preferable. The copolymerization ratio (vinyl aromatic compound / conjugated diene compound) of the vinyl aromatic compound and the conjugated diene compound in the block copolymer is usually 5/95 to 70/30, and more preferably 10/90 to 60/40. Is preferred.

  The number average molecular weight of the block copolymer as the styrene-based elastomer described above is usually 5000 to 600000, preferably 10,000 to 500000, and the molecular weight distribution [weight average molecular weight (Mw) and number average molecular weight (Mn)]. The ratio (Mw / Mn)] is preferably 10 or less. The molecular structure of the block copolymer may be linear, branched, radial, or any combination thereof. A polymer block mainly composed of a vinyl aromatic compound is A, and a conjugated diene. When the polymer block mainly composed of the compound is B, for example, the structure such as ABA, BABA, (AB) 4Si, ABBABA, etc. Can be mentioned. Further, the unsaturated bond of the conjugated diene compound of the block copolymer may be partially hydrogenated.

  The method for producing a block copolymer as a styrene-based elastomer is not particularly limited. For example, according to the method described in Japanese Patent Publication No. 40-23798, Japanese Patent Publication No. 43-171979 or Japanese Patent Publication No. 56-28925, The biblock copolymer can be produced in an inert solvent using a lithium catalyst or the like. Further, hydrogenation is carried out in the presence of a hydrogenation catalyst in an inert solvent by the method described in JP-B-42-8704, JP-B-43-6636, or JP-B-59-133203. A hydrogenated block copolymer can also be produced.

  In the present invention, an epoxy-modified block copolymer can also be used by epoxidizing the above-mentioned block copolymer as a styrenic elastomer. The epoxy-modified block copolymer can be obtained by reacting the above block copolymer with an epoxidizing agent such as hydroperoxides and peracids in an inert solvent. Examples of hydroperoxides include hydrogen peroxide, tertiary butyl hydroperoxide, cumene peroxide and the like, and examples of peracids include performic acid, peracetic acid, perbenzoic acid, and trifluoroperacetic acid. Among these, as the epoxidizing agent, peracetic acid is preferred because it is industrially produced in large quantities, can be obtained at low cost, and has high stability.

In the epoxidation, a catalyst can be used as necessary. For example, when peracids are used as the epoxidizing agent, an alkali such as sodium carbonate or an acid such as sulfuric acid can be used as a catalyst. When hydroperoxides are used, a catalytic effect can be obtained by using a mixture of tungstic acid and caustic soda in combination with hydrogen peroxide or molybdenum hexacarbonyl with tertiary butyl hydroperoxide. There is no strict regulation of the amount of epoxidizing agent, and the optimum amount in each case is determined by the particular epoxidizing agent used, the desired degree of epoxidation, the particular block copolymer used, and the like.

  An inert solvent for producing the epoxy-modified block copolymer is used for the purpose of decreasing the raw material viscosity and diluting and stabilizing the epoxidizing agent. Preferred solvents include hexane, cyclohexane, toluene, Benzene, ethyl acetate, carbon tetrachloride, chloroform. When peracetic acid is used as the epoxy agent, solvents such as ethers and esters can be used.

  The epoxidation reaction conditions are not limited, but the reaction temperature range that can be used is determined by the reactivity of the epoxidizing agent. For example, in the case of peracetic acid, the reaction temperature is preferably from 0 to 70 ° C. If the temperature is lower than 0 ° C., the reaction slows down. Moreover, in the case of the tertiary butyl hydroperoxide / molybdenum dioxide diacetylacetonate system which is an example of hydroperoxide, 20-150 degreeC is preferable for the same reason. No special operation is required for the reaction mixture. For example, the mixture may be stirred for 2 to 10 hours. Isolation of the resulting epoxy-modified copolymer can be carried out by an appropriate method, such as a method of precipitation with a poor solvent, a method of pouring the polymer into hot water with stirring and distilling off the solvent, or a direct solvent removal method. It can be carried out.

  The epoxy equivalent of the epoxy-modified block copolymer is preferably 140 to 2700 g / mol, more preferably 200 to 2000 g / mol. When the epoxy equivalent exceeds 2700 g / mol, the compatibility is lowered and phase separation may occur. Moreover, if it is less than 140 g / mol, side reactions, such as a gelled product, may occur during the isolation of the polymer.

  Examples of polyester elastomers include aromatic polyesters such as polyethylene terephthalate and polybutylene terephthalate as hard segments, polyethers such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol, and fats such as polyethylene adipate, polybutylene adipate and polycaprolactone. Although the block copolymer which uses group polyester as a soft segment is mentioned, it is not limited to this.

  Examples of polyamide-based elastomers include block copolymers having nylon 6, nylon 66, nylon 11, nylon 12 and the like as hard segments and the same polyether or aliphatic polyester as the above as soft segments. It is not limited to.

  Examples of urethane elastomers include reacting diisocyanates such as 4,4′-diphenylmethane diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate and glycols such as ethylene glycol and tetramethylene glycol. Although the block copolymer which makes the polyurethane obtained by this as a hard segment and uses the polyether or aliphatic polyester similar to the above as a soft segment is mentioned, it is not limited to this.

On the other hand, the core-shell polymer is a core-shell type graft copolymer having a multilayer structure and including a shell layer in which a rubber layer is formed of a glassy resin. As the rubber layer of the core-shell type copolymer, those having an average particle diameter of 1.0 μm or less, preferably 0.2 to 0.6 μm can be used. If the average particle size of the rubber layer exceeds 1.0 μm, the effect of improving the impact resistance may be insufficient. As the rubber layer of the core-shell type copolymer, a silicone-based or diene-based elastomer alone, or a copolymer obtained by copolymerizing / grafting two or more kinds of elastomer component systems selected from these can be used.

  The silicon-based elastomer is produced by polymerizing an organosiloxane monomer. Examples of the organosiloxane include hexamethyltricyclosiloxane, octamethylcyclosiloxane, decamethylpentacyclosiloxane, dodecamethylhexacyclosiloxane, Trimethyltriphenylsiloxane, tetramethylphenylcyclotetrasiloxane, octaphenylcyclotetrasiloxane and the like are used.

Furthermore, a vinyl polymer is preferably used as a shell layer formed of a glassy resin of a core-shell type copolymer. The vinyl polymer is obtained by polymerizing at least one monomer selected from an aromatic vinyl monomer, a vinyl cyanide monomer, a methacrylic ester monomer, and an acrylate monomer. Obtained by copolymerization. The rubber layer and the shell layer of such a core-shell type copolymer are usually bonded by graft copolymerization. If necessary, this graft copolymerization is obtained by adding a graft crossing agent that reacts with the shell layer during polymerization of the rubber layer, giving a reactive group to the rubber layer, and then forming the shell layer. As the graft crossing agent, when the rubber layer is a silicone type, an organosiloxane having a vinyl bond or a thiol is used, and among them, an acoxysiloxane, a methacryloxysiloxane, or a vinylsiloxane is preferably used.
Among the above-mentioned impact resistance improvers, olefin-based or styrene-based thermoplastic elastomers or core-shell polymers are preferable.

  The content of the (C) impact modifier in the resin composition of the present invention is 0.5 with respect to a total of 100 parts by weight of the (A) aromatic polyester resin and the (B) aliphatic polyester copolymer. ~ 40 parts by weight. If the amount is less than 0.5 parts by weight, the impact resistance and heat shock resistance may not be improved. If the amount exceeds 40 parts by weight, mechanical properties such as tensile strength and bending strength may deteriorate. . The content of the (C) impact resistance improver is preferably 1 to 35 parts by weight, more preferably 2 to 30 parts by weight, and particularly preferably 5 to 25 parts by weight.

(D) Reinforcing filler In addition to the above-mentioned (A) aromatic polyester resin, (B) aliphatic polyester copolymer, and (C) impact resistance improver, the polyester resin composition of the present invention further comprises (D ) It preferably contains a reinforcing filler. Thereby, there exists a merit that mechanical characteristics, such as impact resistance, and thermal characteristics, such as a deflection temperature under load, improve.

  The reinforcing filler to be filled in the present invention is preferably a fibrous reinforcing material, and the type thereof is not particularly limited. For example, glass fiber, carbon fiber, silica-alumina fiber, zirconia fiber, boron fiber, boron nitride fiber, nitriding Examples thereof include inorganic fibers such as silicon potassium titanate fibers and metal fibers, and organic fibers such as aromatic polyamide fibers, aromatic polyester fibers, aramid fibers, fluororesin fibers, and natural fibers. These fibrous reinforcing materials can be used alone or in combination of two or more. Among these, inorganic fibers, particularly glass fibers are preferable.

Although there is no restriction | limiting in particular in the glass fiber used for this invention, For example, glass fibers, such as E glass, C glass, A glass, S glass, S-2 glass, can be mentioned. Among these, E glass having a low alkali content and good electrical characteristics can be particularly preferably used.
Although there is no restriction | limiting in particular in the average fiber diameter of the fibrous reinforcement used for this invention, 1-100 micrometers, Furthermore, 2-50 micrometers, Especially 3-30 micrometers, Most preferably, 5-20 micrometers is preferable. A fibrous reinforcing material having an average fiber diameter of less than 1 μm is not easy to produce and may increase the cost. Moreover, when the average fiber diameter of a fibrous reinforcement exceeds 100 micrometers, there exists a possibility that the tensile strength of a fibrous reinforcement may fall. Although there is no restriction | limiting in particular in the average fiber length of the fibrous reinforcement used for this invention, 0.1-20 mm, Furthermore, 1-10 mm is preferable. If the average fiber length of the fibrous reinforcing material is less than 0.1 mm, the reinforcing effect by the fibrous reinforcing material may not be sufficiently exhibited. Moreover, when the average fiber length of a fibrous reinforcement exceeds 20 mm, there exists a possibility that melt kneading with resin and shaping | molding of a resin composition may become difficult.

The fibrous reinforcing material used in the present invention, particularly glass fiber, is preferably treated with a surface treating agent. By treating the surface of the glass fiber with the surface treatment agent, strong adhesion or bonding occurs at the interface between the resin and the glass fiber, stress is transmitted from the resin to the glass fiber, and the reinforcing effect by the glass fiber is exhibited. The surface treatment agent used is not particularly limited, and examples thereof include chlorosilane compounds such as vinyltrichlorosilane and methylvinyldichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, and γ-methacryloxypropyltrimethoxysilane. Such as alkoxysilane compounds such as β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, acrylic compounds, isocyanate compounds, titanate compounds And epoxy compounds.

  The fibrous reinforcing material used in the present invention, particularly glass fiber, is preferably treated with a sizing agent. By treating the glass fiber with the sizing agent, it is possible to improve the handling workability of the glass fiber and prevent the glass fiber from being damaged. There is no restriction | limiting in particular in the sizing agent to be used, For example, resin emulsions, such as a vinyl acetate resin, an ethylene-vinyl acetate copolymer, an acrylic resin, an epoxy resin, a polyurethane resin, a polyester resin, etc. can be mentioned.

  In the polyester resin composition of the present invention, other fillers can be blended together with the above-described fibrous reinforcing material. Other fillers include, for example, plate-like inorganic fillers such as glass flakes, mica, metal foil, ceramic beads, asbestos, wollastonite, talc, clay, mica, zeolite, kaolin, potassium titanate, barium sulfate. And particulate inorganic fillers such as titanium oxide, silicon oxide, aluminum oxide, and magnesium hydroxide. Among these, plate-like inorganic fillers, particularly glass flakes, are preferable because they can reduce anisotropy and warpage of the molded product.

  The content of the (D) reinforcing filler is 0 to 150 parts by weight, preferably 5 to 100 parts per 100 parts by weight in total of the (A) aromatic polyester resin and the (B) aliphatic polyester copolymer. Part by weight, more preferably 10 to 70 parts by weight. When the content of the reinforcing filler exceeds 150 parts by weight, melt kneading and molding of the resin composition may be difficult.

  The polyester resin composition of the present invention can be blended with conventional additives as required. For example, mold release agents such as paraffin wax, polyethylene wax, stearic acid and esters thereof, silicone oil; heat stabilizers such as hindered phenols, phosphates, phosphites, thioethers; crystallization accelerators UV absorbers or weather resistance imparting agents; flame retardants and flame retardant aids; resin additives such as dyes, pigments, foaming agents and antistatic agents.

In addition to the above additives, various polyamide resins such as nylon 6, nylon 66, nylon 12 and nylon MXD6, various polyamide elastomers, polycarbonate, various styrene resins (polystyrene, ABS, AS, MS, etc.), various acrylic resins Resins, various olefin resins (polyethylene, polypropylene, ethylene-propylene copolymers, etc.), fluororesins (polytetrafluoroethylene, etc.), ionomer resins, elastomers (isobutylene-isoprene rubber, styrene-butadiene rubber, styrene-butadiene rubber-styrene, Resins such as ethylene-propylene rubber) and thermosetting resins (phenoxy resin, phenol resin, melamine resin, silicone resin, epoxy resin) can be blended.

  The polyester resin composition of the present invention comprises the above (A) aromatic polyester resin, (B) aliphatic polyester copolymer, (C) impact resistance improver, and various additives used as necessary. It is produced by a method of blending, dry blending or melt kneading. Dry blending is performed using, for example, a ribbon blender, a Henschel mixer, a drum blender, or the like. Melt kneading is performed using various extruders, Brabender plastographs, lab blast mills, kneaders, Banbury mixers, and the like. The heating temperature at the time of melt kneading is usually 230 to 290 ° C. In order to suppress decomposition during kneading, it is preferable to use the above heat stabilizer. Each component including an additional component can be supplied to the kneader in a lump or sequentially. Furthermore, two or more kinds of components selected from each component including additional components can be mixed in advance. By adding a fibrous reinforcing filler such as glass fiber after the resin is melted from the middle of the extruder, it can avoid crushing and exhibit high characteristics.

  The polyester resin composition of the present invention can be produced by various molding methods known as thermoplastic resin molding methods such as injection molding, hollow molding, extrusion molding, compression molding, calendar molding, rotational molding, etc. It can be molded into various products used in the electronic equipment field, automobile field, machine field, medical field, packaging field, textile field and the like. In addition, since the resin composition of the present invention has good fluidity, the injection molding method is particularly suitable, and particularly suitable for injection molding thin molded products such as relay cases and large molded products such as automobile outer plates. . During injection molding, it is preferable to control the resin temperature to 240 to 280 ° C. Furthermore, since the molded body obtained from the resin composition of the present invention is excellent in heat shock resistance, it is particularly suitable for insert molding using a metal or an inorganic solid.

  The insert molding method is a molding method in which a metal or an inorganic solid (hereinafter abbreviated as “metal”, etc.) is embedded in a resin to take advantage of the properties of the resin and the metal, such as automobiles, electrical products, OA equipment, and other parts. It is used in a wide range of fields. In particular, parts around automobile engines, such as ignition systems and distributors, which are becoming increasingly resinous in recent years, have complicated structures, large resin wall thickness changes, and changes in temperature because they are used around engines. Is big. The molded product obtained from the resin composition of the present invention is excellent in toughness and impact resistance, and is particularly thin molded having a thickness of 1 cm or less, more preferably 5 mm or less, particularly 3 mm or less, most preferably 1 mm or less. Even if it is a product, it has excellent stability against heat shock and hydrolysis. Therefore, metal parts such as aluminum, copper, iron, and brass are insert-molded with the resin composition of the present invention, and by producing these parts, a molded product having the ability to withstand long-term temperature changes can be obtained. Obtainable.

  The reinforced polyester resin composition of the present invention is excellent in biodegradability and impact resistance, and is expected to be used as various structural materials particularly requiring impact resistance. Specifically, for example, aircraft, rockets, artificial satellites and other aircraft / spacecraft, railways, boats, automobiles, motorcycles, bicycles and other transportation equipment structural materials, outer panels, pressure members; electrical and electronic equipment Cases and internal precision parts; various office supplies such as writing utensils, desks and chairs, and daily necessities including various resin structures can be suitably used. Especially, as above-mentioned, it can use suitably as insert molded articles, such as components for motor vehicles by which the stability with respect to a heat shock is calculated | required.

In addition, the polyester resin composition of the present invention is excellent in molding processability (fluidity) and has high productivity. Therefore, among the above-described uses, particularly, structural materials and outer plates of motorcycles and automobiles with a large production amount, In addition to a pressure member, it is preferably used as a resin structure typified by minute precision parts such as a housing in an electric / electronic device and a gear inside a machine. Specifically, basic frame materials for motorcycle mainframes, automobile platforms, etc .; automotive outer panels such as front apron, hood, roof, hard top roof, pillar, trunk lid, door, fender, side mirror cover; front Aerodynamic members such as air dams, rear spoilers, side air dams, and engine undercovers; automotive interior materials such as instrument panels; housings for electrical and electronic devices such as flexible disks and hard disks; minute precision such as gears, wiring connectors, and various switches Examples include resin structures such as parts.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not restrict | limited to the following examples, unless the summary is exceeded. The raw materials and physical property measurement methods used in the following examples are as follows.

[raw materials]
(A) Aromatic polyester resin (A-1) PBT1
Both raw materials were supplied to a slurry preparation tank at a ratio of 1.8 mol of 1,4-butanediol to 1.0 mol of terephthalic acid, and 1,000 parts by weight of the slurry prepared by mixing with a stirrer was continuously added. And transferred to a first esterification reaction vessel adjusted to a temperature of 230 ° C. and a pressure of 101 kPa by a gear pump, and 0.158 parts by weight of tetrabutyl titanate (30 ppm as Ti amount with respect to the theoretical polymer) was supplied, and the residence time was 2 hours. The oligomer was obtained by esterification with stirring.

The oligomer obtained in the first esterification reaction tank was transferred to a second esterification reaction tank adjusted to a temperature of 240 ° C. and a pressure of 101 kPa, and the esterification reaction was further advanced with stirring for 1 hour.
Next, the oligomer obtained in the second esterification reaction tank was heated at a temperature of 250 ° C. and a pressure of 6.67.
It was transferred to a first polycondensation reaction tank adjusted to kPa, and a polycondensation reaction was carried out with stirring for 2 hours to obtain a prepolymer.

Furthermore, the prepolymer obtained in the first polycondensation reaction tank was transferred to a second double condensation reaction tank adjusted to a temperature of 250 ° C. and a pressure of 133 Pa, and the polycondensation reaction was further advanced with stirring for 3 hours. To obtain a polymer. The polymer was extracted from the second double condensation tank, transferred to a die, drawn into a strand, and cut with a pelletizer to obtain a beret-like polybutylene terephthalate resin (PBT1).
The resulting polybutylene terephthalate resin (PBT1) had a terminal carboxyl group concentration of 20 eq / ton, an intrinsic viscosity of 0.85 dl / g, and a residual tetrahydrofuran amount of 18
It was 0 ppm (weight ratio).

(A-2) PBT2
A total of 1,000 parts by weight of both raw materials was supplied to the transesterification reaction tank so that the ratio of 1.8 mol of 1,4-butanediol to 1.0 mol of dimethyl terephthalate was 0.53 tetrabutyl titanate. Part by weight (100 ppm as the amount of Ti with respect to the theoretical polymer) was added and subjected to a transesterification reaction at a temperature of 210 ° C. and a pressure of 101 kPa for 3 hours to obtain an oligomer.

Subsequently, the obtained oligomer was transferred to a polycondensation reaction tank, and under agitation, a polycondensation reaction was carried out at a temperature of 250 ° C. and a pressure of 133 Pa for 3 hours to obtain a polymer. Next, nitrogen pressure was applied to extract the strand, and the pellet was cut with a pelletizer to obtain a pellet-like polybutylene terephthalate resin (PBT2).
The resulting polybutylene terephthalate resin (PBT2) had a terminal carboxyl group concentration of 41 eq / ton, an intrinsic viscosity of 0.85 dl / g, and a residual tetrahydrofuran amount of 68.
It was 0 ppm (weight ratio).

(A-3) PBT3
In the production method of PBT2, pellets were similarly used except that the amount of tetrabutyl titanate used was 1.00 parts by weight, the polymerization temperature of the polycondensation reaction was 260 ° C., the polymerization pressure was 333 Pa, and the polymerization time was 4 hours. -Shaped polybutylene terephthalate resin (PBT3) was obtained.
The resulting polybutylene terephthalate resin (PBT3) has a terminal carboxyl group concentration of 55 eq / ton, an intrinsic viscosity of 0.85 dl / g, and a residual tetrahydrofuran amount of 70.
It was 0 ppm (weight ratio).

(B) Aliphatic polyester copolymer (B-1) Aliphatic polyester copolymer 1 (PBSL)
In a reaction vessel equipped with a stirrer, a nitrogen inlet, a heating device, and a decompression device, 118.1 parts by weight of succinic acid, 104.5 parts by weight of 1,4-butanediol, and 1% by weight of germanium oxide were dissolved in advance 90 6.40 parts by weight of a weight% lactic acid aqueous solution and 0.2 parts by weight of super talc as a crystal nucleating agent were charged, and the system was placed in a nitrogen atmosphere by nitrogen replacement. Next, the temperature was raised to 220 ° C. while stirring the system, and the reaction was carried out at this temperature for 1 hour. Thereafter, the temperature was raised to 230 ° C. over 30 minutes, and at the same time, the pressure was reduced to 0.07 × 10 ³ Pa over 1 hour and 30 minutes. The intrinsic viscosity of the obtained polyester was 1.82 dl / g. The mol% of each component was 48.8 mol% succinic acid units, 48.8 mol% 1,4-butanediol units, and 2.4 mol% lactic acid units. Let the obtained aliphatic polyester be PBSL (polybutylene succinate lactate).

(B-2) Aliphatic polyester copolymer 2 (PBSLA)
(B-1) In the manufacturing method of aliphatic polyester copolymer-1, except that 118.1 parts by weight of succinic acid was used, 94.48 parts by weight of succinic acid and 29.23 parts by weight of adipic acid were used. Similarly, a polymerization reaction was performed. The intrinsic viscosity of the obtained polyester polymer was 1.82 dl / g. The mol% of each component was 38.7 mol% succinic acid unit, 48.8 mol% 1,4-butanediol unit, 2.8 mol% lactic acid unit, and 9.7 mol% adipic acid unit. The obtained aliphatic polyester is designated as PBSLA (polybutylene succinate lactate adipate).

(C) Impact resistance improver (C-1) Core-shell polymer A copolymer obtained by polymerizing 69.3 parts by weight of butyl acrylate, 0.35 parts by weight of butylene diacrylate and 0.35 parts by weight of diallyl malate, A core-shell type acrylic rubber obtained by graft polymerization of 30 parts by weight of methyl methacrylate.

(C-2) Olefin Elastomer Ethylene-Glycidyl Methacrylate Copolymer (Bondfast 2C: manufactured by Sumitomo Chemical) (C-3) Olefin Elastomer Ethylene-ethyl acrylate copolymer 70 parts by weight and methyl methacrylate-acrylic acid Graft copolymer with 30 parts by weight of butyl copolymer (Modiper A5300: manufactured by NOF Corporation)

(C-4) Olefin-based elastomer Ethylene-ethyl acrylate copolymer (Evaflex EEA A713: manufactured by Nippon Unicar Co., Ltd.)
(C-5) Styrenic elastomer Epoxy-modified styrene-butadiene-styrene block copolymer (ESBS) (Epofriend AT501: manufactured by Daicel Chemical Industries, Ltd.)

(D) Fibrous reinforcing material glass fiber: manufactured by Nippon Electric Glass Co., Ltd., trade name T-187, average fiber diameter 13 μm, average fiber length 3 mm

[Physical property measurement method]
(1) Intrinsic viscosity About PBT resin, it calculated | required from the solution viscosity measured at 30 degreeC in the mixed solvent of 1,1,2,2-tetrachloroethane / phenol = 1: 1 (weight ratio) using the Ubbelohde viscometer. . The Haggins constant was 0.33.
(2) Terminal carboxyl group concentration 0.1 g of resin was dissolved in 3 ml of benzyl alcohol, and a titration method was performed using a sodium hydroxide 0.1 mol / 1 liter benzyl alcohol solution.

(3) Ti atom content The titanium metal concentration (weight ratio) in the PBT resin was quantified by Induced Coupled Plasma (ICP).
(4) Residual tetrahydrofuran amount (THF amount)
5 g of PBT resin pellets were immersed in 10 g of water, treated under pressure at 120 ° C. for 6 hours, and tetrahydrofuran eluted in water was quantified by gas chromatography.

(5) Polymer composition
The composition (mol%) of each component was calculated from the area ratio of the spectrum measured by ¹ H-NMR method.
(6) Melt viscosity The melt viscosity was measured on the conditions of 270 degreeC and the shear rate of 6080 sec- ¹ using the Toyo Seiki Capillograph 1C. It shows that it is excellent in fluidity | liquidity, so that the value of melt viscosity is low.
(7) Charpy impact strength A Charpy impact test was performed according to ISO 179-2.

(8) Biodegradability test After immersing the test piece in the soil for 5 months, if it is observed visually and multiple worm-eaten holes are observed, it is biodegradable (○). It was determined that there was no biodegradability (×).

(9) Heat Shock Resistance Using a rectangular parallelepiped iron insert (16 mm × 33 mm × 3 mm) shown in FIG. 1, it is shown in FIG. Insert molding was performed in the mold cavity, and an insert molded product (18 mm × 35 mm × 5 mm) shown in FIG. 3 was produced from the resin compositions of Examples and Comparative Examples. The thickness of the resin part of this insert molded product is 1 mm. The insert molded product thus obtained had traces of support pins, and two weld lines were generated in the vicinity thereof. About this insert molded product, the heat shock test was done using the thermal shock test apparatus (Irie Seisakusho model DTS-30). The test conditions were a combination of conditions of -40 ° C. for 1 hour and 130 ° C. for 1 hour, and the number of cycles at which cracks occurred in the weld line was determined. The presence or absence of cracks was confirmed every 25 cycles.

[Examples 1-7 and Comparative Examples 1-8]
A mixture obtained by dry blending a PBT resin, an aliphatic polyester copolymer, and an impact resistance improver so as to have a blending ratio shown in Table 1 is a twin-screw extruder (manufactured by Nippon Steel Works, TEX30HSST L / D = 42). On the other hand, glass fiber was introduced from the side feeder, extruded under conditions of a discharge rate of 20 kg / h, a screw rotation speed of 150 rpm, and a barrel temperature of 260 ° C., and pelletized to obtain pellets of a resin composition. .

From the obtained pellets, an ISO test piece was molded under the conditions of a cylinder temperature of 250 ° C. and a mold temperature of 80 ° C. by an injection molding machine (manufactured by Sumitomo Heavy Industries, model SH-100). Characteristics were measured. In addition, a film having a thickness of 0.3 to 0.37 mm was prepared from the obtained pellets using a desktop heat press machine, and this was cut into 2 cm × 2 cm to obtain a test piece, which was biodegraded by the above method. Sex was evaluated. Moreover, the heat shock resistance was evaluated by the method described above. The results are shown in Table 1.

表１の結果から以下のことが判明する。
（１）（Ａ）ＰＢＴ樹脂に（Ｂ）脂肪族ポリエステル共重合体と（Ｃ）耐衝撃改良剤を配合した実施例１〜７の樹脂組成物は、該（Ｂ）共重合体を含まない比較例１〜５の樹脂組
成物に比べ、生分解性を示し、衝撃強度が高く、耐ヒートショック性も著しく改善されている。また、溶融粘度が小さく流動性が良いため、薄肉や大型の成形品に適している。

From the results in Table 1, the following is found.
(1) The resin composition of Examples 1-7 in which (B) an aliphatic polyester copolymer and (C) an impact resistance improver are blended with (A) PBT resin does not contain the (B) copolymer. Compared to the resin compositions of Comparative Examples 1 to 5, the biodegradability is exhibited, the impact strength is high, and the heat shock resistance is remarkably improved. In addition, since it has a low melt viscosity and good fluidity, it is suitable for thin-walled and large-sized molded products.

(2) The resin compositions of Examples 1 to 7 are excellent in impact strength and remarkably improved in heat shock resistance compared to Comparative Examples 6 and 7 that do not contain (C) an impact resistance improver.
(3) Example 2 in which the terminal carboxyl group concentration of (A) PBT resin is 41 eq / ton has higher impact strength and excellent heat shock resistance than Comparative Example 8 in which the concentration is 55 eq / ton. It is excellent for insert molded products.
(4) Example 1 using a PBT resin having a terminal carboxyl group concentration of 20 eq / ton is superior in heat shock resistance compared to Example 2 using a PBT resin having a concentration of 41 eq / ton. Excellent for molded products.

Perspective view of a rectangular parallelepiped iron insert (16 mm × 33 mm × 3 mm) used when insert molding the resin compositions of Examples and Comparative Examples Cross section of mold cavity with inserts supported by support pins Perspective view of an insert-molded product (18 mm x 35 mm x 5 mm) with two weld lines near the support pin mark

Explanation of symbols

1: Insert 2: Support pin 3: Insert 4: Cavity 5: Trace of support pin 6: Weld line

Claims (7)

For (A) aromatic polyester resin 1-99 parts by weight and (B) aliphatic polyester copolymer 1-99 parts by weight in total 100 parts by weight, (C) impact resistance improver is 0.5- A polyester resin composition containing 40 parts by weight, wherein the (A) aromatic polyester resin has a terminal carboxyl group concentration of 50 eq / ton or less, and the (B) aliphatic polyester copolymer has the following (I): 0 to 30 mol% of an aliphatic oxycarboxylic acid unit represented by the formula, 35 to 50 mol% of an aliphatic and / or alicyclic diol unit represented by the following formula (II), and the following formula (III) The polyester resin composition characterized by including 35-50 mol% of aliphatic dicarboxylic acid units represented by these.

  The polyester resin composition according to claim 1, wherein the (A) aromatic polyester resin is a polybutylene terephthalate resin.   The polyester resin composition according to claim 1 or 2, wherein the content of the titanium compound in the (A) aromatic polyester resin is 70 ppm (weight ratio) or less in terms of titanium atoms.   The polyester resin composition according to any one of claims 1 to 3, wherein the (B) aliphatic polyester copolymer contains 0.5 to 20 mol% of an aliphatic oxycarboxylic acid unit represented by the formula (I). .   The polyester resin composition according to any one of claims 1 to 4, wherein the impact modifier (C) is selected from olefin-based or styrene-based thermoplastic elastomers and core-shell polymers.   A molded article obtained by molding the resin composition according to claim 1.   The molded article according to claim 6, wherein the resin composition according to any one of claims 1 to 5 and a metal or an inorganic solid are insert-molded.

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