JP6405954B2 - Polyester resin composition that is flexible and resistant to dirt - Google Patents

Description

  The present invention relates to a polyester resin composition which is flexible and excellent in moldability, impact resistance and weather resistance, without impairing the excellent physical properties, heat resistance and chemical resistance of polybutylene terephthalate (PBT) resin. The present invention relates to a polyester resin composition that is extremely useful as a clip or hole blocking part used in automobile exterior parts with little contamination due to adhesion of earth and sand.

  PBT is widely used for automotive applications, but its non-reinforced molded product lacks impact resistance. In addition, the copolymer elastomer having a PBT skeleton not only has a high price, but also has poor weather resistance and heat resistance because of the copolymer. Polycarbonate resin can also be designed with certain impact resistance, flexibility, and chemical resistance, but since it is extremely inferior in weather resistance, it may not be able to satisfy the characteristics as an automotive exterior part that requires weather resistance.

  Patent Document 1 discloses a polyester copolymer resin composition for thin-wall molding using a combination of a polyester block copolymer, PBT, and a compatibilizing material. This resin composition has high impact resistance in a low temperature environment and excellent moldability. However, since the ratio of the block copolymer is high, the material cost is high and the melting point is low, so that the heat resistance is poor.

  Patent Document 2 discloses a polybutylene terephthalate resin composition in which a stabilizer and a certain amount of a core-shell type elastomer are added to PBT or PBT copolymer and a polyester elastomer. This resin composition is soft and has improved hydrolyzability, but has a high ratio of polyester elastomer, so that the adhesion of dust and earth and sand becomes high.

  Patent Document 3 discloses a resin composition excellent in fluidity and toughness in which a polyester elastomer and a polyfunctional compound having three or more functional groups are blended with PBT. In this resin composition, a polyester elastomer or a modified olefin elastomer is selected as the elastomer component. Since these elastomers have high polarity, they have high adhesion to earth and sand.

  In Patent Documents 4 and 5, an assembly mechanism for attaching a bumper or a fender is disclosed. As an important mechanism, there is an assembly clip. Clips are used for assembling exterior materials, and weather resistance and chemical resistance are required, and it is preferable as quality if it can reduce adhesion of earth and sand and dust, but no specific resin composition for that is taught .

JP2012-126732A JP 2009-263648 A JP 2009-173899 A JP 2002-308150 A JP 2013-112224 A

  The present invention was devised in view of the current state of the prior art described above, and its purpose is to provide excellent physical properties, heat resistance and chemical resistance of PBT resin, in particular, without sacrificing low contamination from surface energy. An object of the present invention is to provide a polyester resin composition which is excellent in moldability and hardly contaminated. In particular, the present invention is resistant to contamination such as earth and sand and dust, and can be easily removed by wiping even if it is contaminated, and because of the blending design that does not impair the good chemical resistance and weather resistance of PBT resin. Provided is a polyester resin composition that is extremely useful as a component, its fastener, or clip.

  As a result of intensive investigations to achieve the above object, the present inventor has made softening by adding an elastomer to the PBT resin at a unique blending ratio. For the elastomer blending, a crystalline polyester elastomer, a modified olefin elastomer, and / or Or by adding a silicone compound according to the compounding of the core-shell type elastomer and adding a carbodiimide compound, it not only lowers the elastic modulus without degrading chemical resistance and weather resistance, but also controls the affinity for water and stains The present invention has been completed.

That is, the present invention has the following configurations (1) to ( 5 ).
(1) 0.3 to 5 parts by mass of a silicone compound (E), a carbodiimide compound (A) based on 60 to 90 parts by mass of a polybutylene terephthalate resin (A) and 40 to 10 parts by mass of a thermoplastic elastomer. F) A polyester resin composition containing 0.1 to 5 parts by mass, wherein the thermoplastic elastomer includes the modified olefin elastomer (B) , and optionally, a crystalline polyester elastomer (C) or a core-shell type It contains an elastomer (D) or contains both a crystalline polyester elastomer (C) and a core-shell type elastomer (D) , a modified olefin-based elastomer (B), a crystalline polyester elastomer (C) and a core-shell type elastomer (D ) Is ((B) + (C)) ≧ (D) , And modified olefin elastomer (B), characterized in that one or more ethylenically resin selected to 0.01 to 15 wt% of maleic acid or glycidyl methacrylate anhydride from copolymerized ethylene copolymer Polyester resin composition.
(2) The intrinsic viscosity of the polybutylene terephthalate resin (A) is 0.65 to 0.85 dL / g, and the Charpy impact value with a notch is 10 kJ / m ² or more. Polyester resin composition.
( 3 ) A hard segment comprising a crystalline polyester in which the crystalline polyester elastomer (C) is composed of an aromatic dicarboxylic acid and an aliphatic or alicyclic diol, an aliphatic polyether, an aliphatic polyester and an aliphatic polycarbonate The polyester resin composition according to (1) or (2 ), wherein the polyester resin composition comprises at least one soft segment selected from the group consisting of 10 to 85% by mass.
( 4 ) The polyester resin composition according to any one of (1) to ( 3 ), wherein no crack is generated in the ultraviolet irradiation test.
( 5 ) A molded article for an automobile exterior comprising the polyester resin composition according to any one of (1) to ( 4 ).

  The polyester resin composition of the present invention is not only flexible and excellent in hydrolysis resistance and weather resistance, but also has a high design property that can be wiped off immediately even when it gets dirty, with little adhesion in soil and dirt. It can be suitably used as a plastic molded product such as a clip useful for mounting automobile exterior members, exterior steel plates, and exterior resin molded products.

FIG. 1 shows an enlarged photograph of the surface state of the resins of Example 1 and Comparative Example 6 after the weather resistance test.

Hereinafter, the polyester resin composition of the present invention will be described in detail.
The polyester resin composition of the present invention is based on a resin composition in which a specific thermoplastic elastomer ((B), (C) and / or (D)) is blended in a specific blending ratio with the polybutylene terephthalate resin (A). The silicone compound (E) is blended as necessary, and the carbodiimide compound (F) is blended.

  The polybutylene terephthalate resin (A) can be produced by a known polycondensation method or ring-opening polymerization method, and may be either batch polymerization or continuous polymerization. Transesterification and direct polymerization can also be applied. From the viewpoint of reducing the amount of carboxyl end groups and controlling the fluidity, continuous polymerization is preferred, and direct polymerization is preferred from the viewpoint of cost. Regarding components and constitution, a dicarboxylic acid component containing at least terephthalic acid or an ester-forming derivative thereof, such as a lower alcohol ester, and a glycol containing at least C 4 alkylene glycol (1,4-butanediol) or an ester-forming derivative thereof It is preferably obtained by polycondensation with components. The polybutylene terephthalate resin (A) is not limited to a homopolybutylene terephthalate resin, but may be a copolymer containing 80 mol% or more of butylene terephthalate units.

  The polybutylene terephthalate resin (A) is usually an intrinsic viscosity (IV) measured at a temperature of 30 ° C. using a mixed solvent of 1,1,2,2-tetrachloroethane / phenol = 1/1 (mass ratio). Is preferably 0.65 to 0.85 dl / g. The upper limit of the intrinsic viscosity is more preferably 0.83 dl / g, still more preferably 0.80 dl / g, and the lower limit is more preferably 0.68 dl / g, still more preferably 0.70 dl / g. If the intrinsic viscosity is less than the above range, the mechanical strength of the resin composition is lowered. Conversely, if the intrinsic viscosity is greater than the above range, the fluidity is poor and the moldability may be impaired. In addition, the polybutylene terephthalate resin (A) may be adjusted so as to have the above-mentioned intrinsic viscosity by using two or more kinds having different intrinsic viscosities.

  The polybutylene terephthalate resin (A) preferably has a carboxyl end group content of 30 meq / kg or less from the viewpoints of fluidity and hydrolysis resistance. The amount of carboxyl end groups can be determined by pulverizing a polybutylene terephthalate resin and dissolving it in benzyl alcohol at 200 ° C., followed by titration with a 0.01N sodium hydroxide aqueous solution.

  In the polyester resin composition of the present invention, a thermoplastic elastomer is blended with the polybutylene terephthalate resin (A) described above. As the thermoplastic elastomer, at least one selected from the group consisting of a modified olefin elastomer (B), a crystalline polyester elastomer (C), and a core-shell type is used.

  The modified olefin elastomer (B) is preferably an ethylene copolymer obtained by copolymerizing maleic anhydride or 0.01 to 15% by mass of glycidyl methacrylate. Furthermore, it is preferably a modified ethylene copolymer obtained by copolymerizing ethylene (co) polymer with maleic anhydride or glycidyl methacrylate 0.01 to 15% by mass, preferably 0.01 to 10% by mass. These can be produced by a conventionally known method, and may be a method produced by ordinary copolymerization or a method produced by graft copolymerization.

  Further, the modified olefin elastomer (B) may be used alone or in combination of two or more selected from an unmodified ethylene copolymer and a modified ethylene copolymer. It is preferable that at least one glass transition temperature used is −30 ° C. or lower for improving impact resistance at a low temperature of −30 ° C. or lower.

  The crystalline polyester elastomer (C) comprises a hard segment composed of a crystalline polyester composed of an aromatic dicarboxylic acid and an aliphatic or alicyclic diol, and a group composed of an aliphatic polyether, an aliphatic polyester and an aliphatic polycarbonate. It is preferable to use at least one kind of soft segment selected from as the main component (70% by mass or more), and the content of the soft segment component is preferably 10 to 85% by mass.

  In the crystalline polyester elastomer (C), a normal aromatic dicarboxylic acid is widely used as the aromatic dicarboxylic acid constituting the hard segment polyester, and the main aromatic dicarboxylic acid is terephthalic acid or naphthalenedicarboxylic acid. It is desirable that Other acid components include diphenyl dicarboxylic acid, isophthalic acid, aromatic dicarboxylic acid such as 5-sodium sulfoisophthalic acid, cycloaliphatic dicarboxylic acid, alicyclic dicarboxylic acid such as tetrahydrophthalic anhydride, succinic acid, glutaric acid, adipine Examples thereof include aliphatic dicarboxylic acids such as acid, azelaic acid, sebacic acid, dodecanedioic acid, dimer acid, and hydrogenated dimer acid. These are used within a range that does not significantly lower the melting point of the resin, and the amount thereof is less than 30 mol%, preferably less than 20 mol% of the total acid component.

  In the crystalline polyester elastomer (C), as the aliphatic or alicyclic diol constituting the hard segment polyester, general aliphatic or alicyclic diols are widely used and are not particularly limited. It is desirable that the alkylene glycol is ˜8. Specific examples include ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol and the like. Most preferred are 1,4-butanediol and 1,4-cyclohexanedimethanol.

  The component constituting the hard segment polyester is preferably a butylene terephthalate unit or a butylene naphthalate unit in terms of physical properties, moldability, and cost performance.

  In the crystalline polyester elastomer (C), an aromatic polyester suitable as a polyester constituting the hard segment can be easily obtained according to a normal polyester production method. Moreover, what has the number average molecular weight 10000-40000 is preferable for this polyester.

  In the crystalline polyester elastomer (C), the aliphatic polyether as a soft segment component is poly (ethylene oxide) glycol, poly (propylene oxide) glycol, poly (tetramethylene oxide) glycol, poly (hexamethylene oxide) glycol, ethylene oxide. And a copolymer of propylene oxide, an ethylene oxide addition polymer of poly (propylene oxide) glycol, a poly (alkylene oxide) glycol such as a copolymer of ethylene oxide and tetrahydrofuran, and the like.

  Among the above aliphatic polyethers, poly (tetramethylene oxide) glycol, ethylene oxide adducts of poly (propylene oxide) glycol, and copolymer glycols of ethylene oxide and tetrahydrofuran are preferred, more preferably poly (tetramethylene oxide) glycol, It is an ethylene oxide adduct of poly (propylene oxide) glycol. In addition, the number average molecular weight of these soft segments is preferably about 300 to 6000 in the copolymerized state.

  As for the copolymerization amount of the soft segment of crystalline polyester elastomer (C), 10-85 mass% is preferable, More preferably, it is 20-85 mass%.

  The crystalline polyester elastomer (C) can be produced by a conventionally known method. For example, a method in which a lower alcohol diester of a dicarboxylic acid, an excess amount of a low molecular weight glycol, and a soft segment component are transesterified in the presence of a catalyst and the resulting reaction product is polycondensed, a dicarboxylic acid and an excess amount of glycol and a soft A method can be employed in which the segment component is esterified in the presence of a catalyst and the resulting reaction product is polycondensed.

  The core-shell type elastomer (D) may be an elastomer having a core-shell structure. For example, one of the core layer and the shell layer is composed of a rubber component (soft component), and the other component is composed of a hard component. Are listed. The core-shell type elastomer (D) usually has a multilayer structure including a core layer composed of a rubber component and a shell layer composed of a hard resin (such as a glassy resin) covering or enclosing the core layer. There are many cases.

  The core-shell type elastomer (D) has a rubber layer selected from a butadiene component-containing rubber, a butyl acrylate component-containing rubber, and a silicone rubber from the viewpoint of improving the impact resistance of the resin composition, and an acrylic ester around the core layer. A core-shell type elastomer comprising a shell layer formed by graft polymerization of a monomer selected from a methacrylic ester and an aromatic vinyl compound is particularly preferred.

  Examples of core-shell type elastomers include methyl methacrylate-butadiene-styrene polymer (MBS), methyl methacrylate-acrylonitrile-butadiene-styrene polymer (MABS), methyl methacrylate-butadiene polymer (MB), methyl methacrylate-acrylic rubber heavy Copolymer (MA), methyl methacrylate-acrylic rubber-styrene polymer (MAS), methyl methacrylate-acrylic butadiene rubber copolymer, methyl methacrylate-acrylic butadiene rubber-styrene copolymer, methyl methacrylate (acrylic silicone IPN (INTERPRETETRATING POLYMER NETWORK) rubber) and the like. These rubbery polymers may be used alone or in combination of two or more.

  The glass transition temperature of the core layer (rubber component) of the core-shell type elastomer (D) is preferably less than 0 ° C., more preferably −20 ° C. or less, and still more preferably −30 ° C. or less in order to obtain an effect even at a low temperature.

  The shell layer can be composed of, for example, a hard resin component, and can be generally composed of a vinyl polymer. Vinyl polymers include aromatic vinyl monomers (such as styrene and α-methylstyrene), vinyl cyanide monomers (such as (meth) acrylonitrile), methacrylic acid ester monomers, and acrylic acid esters. It can be composed of a single or copolymer of at least one monomer selected from monomers. Examples of the methacrylic acid ester monomer include alkyl methacrylate (for example, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, etc., alkyl methacrylate having 1 to 20 carbon atoms, preferably carbon Examples thereof include alkyl methacrylate having 1 to 10 carbon atoms, more preferably alkyl methacrylate having 1 to 6 carbon atoms, aryl methacrylate (such as phenyl methacrylate), and cycloalkyl methacrylate (such as cyclohexyl methacrylate). Examples of the acrylate monomer include the acrylate ester of the core layer. In many cases, the vinyl polymer is a polymer having at least one selected from methacrylic monomers and aromatic vinyl monomers [particularly, at least methyl methacrylate, etc.] as a polymerization component. The vinyl polymer constituting the shell layer may be a copolymer with the same crosslinkable monomer as described above.

  The glass transition temperature of the shell layer is preferably 30 ° C. or higher, more preferably 50 ° C. or higher, more preferably 70 ° C. or higher from the viewpoint of handling and heat resistance.

  The average particle size of the core-shell type elastomer (D) is, for example, preferably 0.05 to 10 μm, more preferably 0.05 to 5 μm, still more preferably 0.1 to 3 μm. The core layer (rubber layer) of the core-shell type elastomer (D) and the shell layer are usually bonded by a graft bond, and this graft bond can be added to the polymerization component of the core layer (rubber layer) as a shell layer. It can be obtained by adding a reactive graft crossing agent to give a reactive group to the rubber layer and then forming a shell layer.

  As the core-shell type elastomer (D), those prepared by a conventional method (emulsion polymerization method, seed polymerization method, micro suspension polymerization method, suspension polymerization method, etc.) may be used, or commercially available products may be used. More specifically, a product “Paraloid EXL-2620” from Rohm and Haas Japan Co., Ltd. can be obtained and used.

  The polyester resin composition of the present invention has a modified olefin elastomer (B) and a crystalline polyester elastomer (C) with respect to 60 to 90 parts by mass of the polybutylene terephthalate resin (A) in terms of impact resistance and flexibility. And 40 to 10 parts by mass of a thermoplastic elastomer selected from at least one elastomer selected from the core-shell type elastomer (D). If the thermoplastic elastomer is less than 10 parts by mass, the desired impact resistance and flexibility cannot be obtained, and if it exceeds 40 parts by mass, the moldability is deteriorated.

  Furthermore, the polyester resin composition of the present invention comprises 0-5 mass% of the silicone compound (E) and the carbodiimide compound (F) with respect to the resin composition in which the thermoplastic elastomer is blended with the polybutylene terephthalate resin (A). 0.1-5 mass% is mix | blended.

  The silicone compound (E) is preferably selected from, for example, the following (i) to (iii).

(I) A silicone compound having an OH group in the side chain, which is represented by the following general formula (I):
(In the formula (I), R ¹ and R ² are alkyl groups, EO represents ethylene oxide, and PO represents propylene oxide.)

  (Ii) A product obtained by graft polymerization of a crystalline resin-reactive polyorganosiloxane grafted with 30% by mass or more of a silicone compound onto a thermoplastic crystalline resin. In addition, as said crystalline resin, although various polyethylene resins, ethylene / olefin type resin, etc. are preferable, it is not limited to this.

  (Iii) Containing polar groups such as amino groups, hydroxyl groups, carboxyl groups, acid anhydride groups, and epoxy groups that react with the polyamide resin at both or one end of the silicone compound polyorganosiloxane having polar groups that react with the polyamide resin A silicone compound.

  The compounding amount of the silicone compound (E) in the polyester resin composition of the present invention is 100 parts by mass of the total amount of the polybutylene terephthalate resin (A) and the thermoplastic elastomer ((B) + (C) + (D)). Then, 0-5 mass parts is preferable. More preferably, when the blending ratio of the modified olefin-based elastomer (B), the crystalline polyester elastomer (C) and the core-shell type elastomer (D) is ((B) + (C)) ≧ (D), the silicone compound (E) Is 0.3 to 5 parts by mass and ((B) + (C)) <(D), the silicone compound (E) is less than 0.3 parts by mass. The modified olefin elastomer (B) and the crystalline polyester elastomer (C) have a high affinity for water with respect to the core-shell type elastomer (D), and increase the ratio of the components (B) and (C) in the thermoplastic elastomer. If the amount is too large, contamination using water as a medium increases, and it is preferable to add a large amount of silicone compound (E) to prevent this. On the other hand, when the ratio of the core-shell type elastomer (D) in the thermoplastic elastomer is high, the smaller the amount of the silicone compound (E) added, the better the physical properties and the necessary stain resistance may be imparted.

  When the silicone compound (E) is a crystalline resin grafted with a silicone compound, a compatibilizing agent may be added to improve the compatibility between the silicone compound (E) and the PBT resin. When the crystalline resin is a polyethylene resin, it is preferable to add a modified polyethylene resin as a compatibilizing agent, and the modified olefin elastomer (B) corresponds to this compatibilizing agent.

  The carbodiimide compound (F) is a carbodiimide having two or more —N═C═N— structures in one molecule, and includes aliphatic carbodiimides, alicyclic carbodiimides, aromatic carbodiimides, and combinations of these structures. A polymer etc. are mentioned.

  The carbodiimide compound (F) is prepared, for example, by a carbon dioxide removal reaction of a diisocyanate compound, and usable diisocyanates include 4,4-diphenylmethane diisocyanate, 4,4-diphenyldimethylmethane diisocyanate, 1,3-phenylene diisocyanate. 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,5-naphthylene diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diene Isocyanate, isophorone diisocyanate, methylcyclohexane diisocyanate, tetramethylxylylene diisocyanate, 1,3,5-tri And isopropyl phenylene-2,4-diisocyanate were copolymerized alone or in combination of two or more kinds may be used. Moreover, you may introduce | transduce a branched structure or introduce | transduce functional groups other than a carbodiimide group or an isocyanate group by copolymerization. Furthermore, the degree of polymerization can be controlled and the terminal isocyanate can be blocked by blocking part or all of the terminal isocyanate. As the end-capping agent, monoisocyanate compounds such as phenyl isocyanate, tris isocyanate, dimethylphenyl isocyanate, cyclohexyl isocyanate, butyl isocyanate, naphthyl isocyanate, -OH group, -COOH group, -SH group, -NH-R (R is hydrogen) A compound having an atom or an alkyl group) can be used.

  The number of carbodiimide groups in the carbodiimide compound (F) is preferably 2 to 50, more preferably 5 to 30 in terms of stability and handleability. When the polymerization degree is solid at around room temperature, it is pulverized and excellent in workability and compatibility when mixed with a thermoplastic elastomer, and is preferable in terms of uniform reactivity and bleed-out resistance.

  The carbodiimide compound (F) is blended in an amount of 0.1 to 5 parts by mass when the total amount of the polybutylene terephthalate resin (A) and the thermoplastic elastomer ((B) + (C) + (D)) is 100 parts by mass. It is preferably 0.5 to 5 parts by mass, more preferably 1 to 4 parts by mass. If the blending amount exceeds the above range, the flexibility, mechanical properties, heat resistance, and melt viscosity decrease, which is not preferable. Moreover, when it is less than the above range, the amount of —N═C═N— in the composition is decreased, and the effect of improving hydrolysis resistance is inferior.

  It is preferable to add a stabilizer to the resin composition of the present invention. For example, a hindered phenol antioxidant is preferable. Specifically, 3,5-di-t-butyl-4-hydroxy-toluene, n-octadecyl-β- (4′-hydroxy-3 ′, 5′-di-t-butylphenyl) propionate, tetrakis [ Methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, 1,3,5-trimethyl-2,4,6′-tris (3,5-di-) t-butyl-4-hydroxybenzyl) benzene, calcium (3,5-di-t-butyl-4-hydroxy-benzyl-monoethyl-phosphate), triethylene glycol-bis [3- (3-t-butyl -5-methyl-4-hydroxyphenyl) propionate], penterythrityl-tetrakis [3- (3,5-di-t-butylanilino) -1,3,5-triazine, 3,9- [1,1-dimethyl-2- {β- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl] 2,4,8,10-tetraoxaspiro [5,5] Undecane, bis [3,3-bis (4′-hydroxy-3′-t-butylphenyl) butyric acid] glycol ester, triphenol, 2,2′-ethylidenebis (4,6-di-t-butylphenol), N, N′-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine, 2,2′-oxamidobis [ethyl-3- (3,5-di-t-butyl) -4-hydroxyphenyl) propionate], 1,1,3-tris (3 ′, 5′-di-t-butyl-4′-hydroxybenzyl) -S-triazine-2,4,6 (1H, 3H, 5H)- Rion, 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, 3,5-di-t-butyl-4-hydroxyhydrocinnamic ahydrester With-1,3,5-tris (2-hydroxyethyl) -S-triazine-2,4,6 (1H, 3H, 5H), N, N-hexamethylenebis (3,5-di-t-butyl -4-hydroxy-hydrocinnamide) and the like. Among these, those having a molecular weight of 500 or more such as tetrakis [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane are preferable.

  Sulfur antioxidants are also preferred as stabilizers. Specifically, dilauryl-3,3′-thiodipropionic acid ester, dimyristyl-3,3′-thiodiuropionic acid ester, distearyl-3,3′-thiodipropionic acid ester, laurylstearyl-3,3 ′ -Thiodipropionic acid ester, dilauryl thiodipropionate, dioctadecyl sulfide, pentaerythroleyl-tetra (β-lauryl-thiopropionate) ester, and the like. Among these, thiodipropion ester compounds are particularly preferable.

  Stabilizers that can be used in the present invention are not limited to those described above, and there is no problem in simultaneously using a plurality of other stabilizers. When the total amount of the polybutylene terephthalate resin (A) and the thermoplastic elastomer ((B) + (C) + (D)) is 100 parts by mass, the stabilizer is preferably 0.01 to 5 parts by mass, more preferably. Is 0.05 to 3 parts by mass, more preferably 0.1 to 1.5 parts by mass. If the blending amount is less than the above range, it is difficult to obtain the intended effect of improving heat resistance, and if it exceeds the above range, bleeding may occur and the appearance may be deteriorated.

  Furthermore, in the polyester resin composition of the present invention, in addition to the stabilizer described above, various additives can be blended depending on the purpose within a range that does not impair the effects of the present invention, thereby obtaining a composition. Additives include known hindered amines, triazoles, benzophenones, benzoates, nickels, salicyls and other light stabilizers, antistatic agents, lubricants, molecular modifiers such as peroxides, metal deactivators, Organic and inorganic nucleating agents, neutralizing agents, antacids, antibacterial agents, fluorescent brighteners, fillers, flame retardants, flame retardant aids, organic and inorganic pigments, and the like can be added. These additives are combined in a total amount of 40 parts by mass or less, assuming that the total amount of the polybutylene terephthalate resin (A) and the thermoplastic elastomer ((B) + (C) + (D)) is 100 parts by mass. Is possible.

  The method for producing the polyester resin composition of the present invention is selected from the polybutylene terephthalate resin (A) in the present invention, the modified olefin elastomer (B), the crystalline polyester elastomer (C), and the core-shell type elastomer (D). What is necessary is just to melt-knead, after mix | blending each component, such as a silicone compound (E) and a carbodiimide compound (F), with a predetermined | prescribed mixture ratio with respect to the resin composition which consists of at least 1 sort (s) of elastomer. For mixing, a Henschel mixer, a ribbon blender, a V-type blender, or the like can be used. For melt kneading, a Banbury mixer, a kneader-type heater, a single or twin screw melt kneading extruder, or the like can be used.

  The flexural modulus of the polyester resin composition of the present invention is measured according to ISO178. The flexural modulus of the polyester resin composition of the present invention is preferably 1.8 GPa or less. By setting the flexural modulus within this range, it can be expected that the flexibility of the product is obtained. In order to make the flexural modulus within this range, it is important that the polyester resin composition has the above composition. The flexural modulus is more preferably 1.6 GPa or less, and further preferably 1.5 GPa or less.

  The polyester resin of the present invention obtains necessary impact resistance and flexibility by blending a modified olefin elastomer and a crystalline polyester elastomer while satisfying the necessary weather resistance by using PBT as a base. Furthermore, the surface characteristics expressed by the blending ratio of these elastomers are further controlled by adding specific silicone compounds as needed according to the blending of PBT and elastomer, and both impact resistance, low contamination and weather resistance are combined. A resin composition can be provided.

  The polyester resin composition of the present invention is preferably molded by injection molding. Injection molding is excellent in the efficiency of thermoplasticization, molding and cooling by melting, and it is possible to produce a large amount of molded products in a short time. The degree of freedom in shape design is also excellent, and a shape design that maximizes the characteristics of the polyester resin of the present invention can be achieved.

  Since the polyester resin composition of the present invention is produced as described above, the molded product is flexible, excellent in moldability and hardly contaminated, and even if it is contaminated, it has a characteristic that it can be easily removed by wiping. Therefore, the polyester resin composition of the present invention can be suitably used as an automobile exterior member, its fastener, or clip.

  Hereinafter, the present invention will be described in detail with reference to examples and comparative examples. However, the present invention is not limited to the following examples as a matter of course, and the present invention is modified and implemented within a range that can meet the gist of the preceding and following descriptions. These are all included in the technical scope of the present invention. In addition, in this specification, each measurement followed the following method.

[Composition analysis of crystalline polyester elastomer]
The composition of the thermoplastic polyester elastomer was determined from its integral ratio by ¹ H-NMR analysis using a nuclear magnetic resonance analyzer (NMR) Gemini-200 manufactured by Varian in a deuterated chloroform solvent.

[Reduced viscosity of crystalline polyester elastomer]
0.05 g of resin was dissolved in 25 mL of a mixed solvent (phenol / tetrachloroethane = 60/40) and measured at 30 ° C. using an Ostwald viscometer.

[Melting point of crystalline polyester elastomer (Tm)]
The resin dried under reduced pressure at 50 ° C. for 15 hours was measured using a differential scanning calorimeter DSC-50 (manufactured by Shimadzu Corporation) at a temperature increase rate of 20 ° C./min from the room temperature, and the endothermic peak temperature due to melting was taken as the melting point. In addition, 10 mg of a measurement sample was weighed in an aluminum pan (TA Instruments, product number 900793.901), sealed with an aluminum lid (TA Instruments, product number 900794.901), and measured in an argon atmosphere. .

(Flexural modulus)
It calculated | required based on ISO187.

[Charpy impact value]
It calculated | required based on ISO179 (with a notch).

[Contact angle with water]
Referring to JIS-R3257, the contact angle of water with a 2 mm-thick flat test piece prepared by injection molding the compositions of Examples and Comparative Examples and water contact angle meter manufactured by Kyowa Interface Science Co., Ltd. CA- Measured using VP type. A water droplet of 5 μl was dropped on the surface of the test piece, the water drop after 30 seconds was photographed with a camera, and the contact angle was measured from the obtained image with a protractor.

[Contamination]
Those having a contact angle with water of less than 79 degrees are judged to have high wettability and high contamination (x), and those having a contact angle with water of 79 degrees or more are water repellent and have low contamination (○). It was determined.

〔Weatherability〕
Using a “Super UV Tester” manufactured by Iwasaki Electric Co., Ltd., after treatment at 63 ° C., no condensation, and irradiation intensity of 60 mW / cm ² for 50 hours, the presence of cracks was confirmed by surface observation with a microscope. Those with cracks were determined to have poor weather resistance (x), and those without cracks were determined to have good weather resistance (◯). In addition, the enlarged photograph of the surface state after the weather resistance test of resin of Example 1 and Comparative Example 6 is shown in FIG.

[Calcium chloride resistance]
(I) 80 ° C. × 95% × 4 hours treatment, (ii) 23 ° C. saturated calcium chloride aqueous solution applied and left for 30 minutes, (iii) 100 ° C. × 2 hours treatment, (iv) 23 ° C. room temperature × 18 hours standing . Bending strength and crack observation were carried out after 10 cycles of treatment (i) to (iv) described above as one cycle. When the retention rate of bending strength is 80% or more and there is no crack, it is judged that the calcium chloride resistance is good (O), and when the bending strength retention rate is less than 80% or when cracks occur on the surface, the calcium chloride resistance is poor. (X) was determined.

〔Comprehensive evaluation〕
Charpy impact value of 10 kJ / m ² or more, flexural modulus of 1.8 GPa or less, contact angle with water (O), good contamination (O), good weather resistance (O), calcium chloride resistance (O) When all of the conditions were satisfied, a comprehensive evaluation (◯) was made. When any of the conditions was not satisfied, the overall evaluation (x) was made.

[Polybutylene terephthalate resin (PBT) (A)]
A-1: 1200-211E Intrinsic viscosity = 0.68, Carboxyl end = 21 meq / kg (CHANGE CHUN PLASTICS CO., LTD.)
A-2: 1200-211M Intrinsic viscosity = 0.84, Carboxyl end = 12 meq / kg (CHANGE CHUN PLASTICS CO., LTD.)

[Modified olefin elastomer (B)]
B-1: Bond First 7M (manufactured by Sumitomo Chemical Co., Ltd., ethylene / methyl acrylate / glycidyl methacrylate copolymer, glass transition temperature-33 ° C., GMA content 6%)
B-2: Bond First 7L (manufactured by Sumitomo Chemical Co., Ltd., ethylene / methyl acrylate / glycidyl methacrylate copolymer, glass transition temperature about −33 ° C. GMA content 3%)

[Crystalline polyester elastomer (C)]
Crystalline polyester elastomers (C-1) and (C-2) having the compositions shown in Table 1 using dimethyl terephthalate, 1,4-butanediol, and poly (tetramethylene oxide) glycol having a number average molecular weight of 1000 as raw materials. Synthesized. Table 1 shows the composition and various physical properties of the obtained polyester elastomer.

[Core-shell type elastomer (D)]
Rohm and Haas Co., Ltd. “Paraloid EXL2620”

[Silicone compound (E)]
“BY27-202H” manufactured by Toray Dow Corning Co., Ltd.

[Carbodiimide compound (F-1)]
To 262 g of 4,4′-dicyclohexylmethane diisocyanate (hereinafter also referred to as HMDI), 1.5 g of 3-methyl-1-phenyl-2-phospholene-1-oxide (hereinafter abbreviated as carbodiimidization catalyst) as a carbodiimidization catalyst In addition, a polycarbodiimide (C-1) derived from HMDI (polymerization degree = 20, isocyanate group content 1.8%) was obtained by performing a condensation reaction at 185 ° C. for 28 hours while bubbling nitrogen.

[Carbodiimide compound (F-2)]
A commercially available polycarbodiimide (“HMV-15CA” manufactured by Nisshinbo Chemical Co., Ltd.) was used.

〔Antioxidant〕
In the preparation of Examples and Comparative Examples, 0.2 parts by mass of hindered phenol stabilizer Irganox 1010 (manufactured by BASF) and sulfur stabilizer Seanox 412S (manufactured by Sipro Kasei) were added during compounding.

[Release agent, black pigment]
In the preparation of Examples and Comparative Examples, 0.6 parts by mass of the following release agent and 1.0 part by mass of black pigment master (as carbon black) were added during compounding.
Mold release agent: WE40 (Montanic acid ester wax manufactured by Clariant)
Black pigment: ABF-T-9801 (carbon black masterbatch manufactured by Resino Color)

[Examples 1 and 2, Reference Example 3, Examples 4 and 5, Comparative Examples 1 to 7]
Polybutylene terephthalate resin (A), modified olefin elastomer (B), crystalline polyester elastomer (C), core-shell elastomer (D), silicone compound (E), carbodiimide compound (F), antioxidant, mold release Each component of the agent and the black pigment is dry blended at a blending ratio shown in Table 2, and melt-kneaded at a temperature setting of 240 to 260 ° C. using a 35 mmφ twin screw extruder (manufactured by Toshiba Machine Co., Ltd.) to form a strand. Extruded, cooled with water and pelletized with a pelletizer. The obtained pellets were dried under reduced pressure at 100 ° C. for 5 hours to obtain a polyester resin composition. Furthermore, as materials and brands already used in automobile exteriors, impact-resistant polyamide “Gramide TY102ND” manufactured by Toyobo Co., Ltd. as Comparative Example 5 and impact-resistant polyacetal resin manufactured by Polyplastics Co., Ltd. as Comparative Example 6 As “Duracon FT-20” and Comparative Example 7, polycarbonate resin “Iupilon S-2000” manufactured by Mitsubishi Engineering Plastics Co., Ltd. was prepared. These evaluation results are shown in Table 2.

As is clear from the results in Table 2, the polyester resin compositions of Examples 1 and 2, Reference Example 3, and Examples 4 and 5 are not only flexible and have a high Charpy impact value, but also have a contact angle with water and contamination. Excellent in weatherability, weather resistance and calcium chloride resistance. On the other hand, the composition of Comparative Examples 1-4 is inferior to an Example in any one of the above-mentioned items. In Comparative Examples 5 to 7, which are non-polyester materials corresponding to materials and brands already used in automobile exteriors, polyamide (Comparative Example 5) has poor calcium chloride resistance and has improved impact resistance polyacetal (Comparative Example 6). ), Polycarbonate (Comparative Example 7) has poor weather resistance and is inferior to the Examples.

  The polyester resin composition of the present invention is flexible and not only excellent in hydrolysis resistance and weather resistance, but also has high design characteristics that can be wiped off immediately even if it gets dirty, with little adhesion in soil and dirt. Therefore, it can be suitably used as a plastic molded product such as a clip useful for mounting an automobile exterior member, an exterior steel plate, or an exterior resin molded product.

Claims (5)

Against polybutylene terephthalate resin (A) resin composition containing a thermoplastic elastomer 40-10 parts by weight of 60 to 90 parts by mass, the silicone compound (E) 0.3 to 5 parts by weight of a carbodiimide compound (F) 0 A polyester resin composition containing 1 to 5 parts by mass, wherein the thermoplastic elastomer includes the modified olefin elastomer (B) , and optionally, a crystalline polyester elastomer (C) or a core-shell type elastomer (D ) Or including both of the crystalline polyester elastomer (C) and the core-shell type elastomer (D), the blending of the modified olefin elastomer (B), the crystalline polyester elastomer (C) and the core-shell type elastomer (D) The ratio is ((B) + (C)) ≧ (D), and Modified olefin elastomer (B) is a polyester resin, which is a one or more ethylene-based resin is selected to 0.01 to 15 wt% of maleic acid or glycidyl methacrylate anhydride from copolymerized ethylene copolymer Composition. ^2. The polyester resin according to claim 1, wherein the polybutylene terephthalate resin (A) has an intrinsic viscosity of 0.65 to 0.85 dL / g and a Charpy impact value with a notch of 10 kJ / m ² or more. Composition. The crystalline polyester elastomer (C) is selected from a hard segment composed of a crystalline polyester composed of an aromatic dicarboxylic acid and an aliphatic or alicyclic diol, an aliphatic polyether, an aliphatic polyester and an aliphatic polycarbonate. containing at least one soft segment, a polyester resin composition according to claim 1 or 2, wherein the content of the soft segment component is 10 to 85 mass%. The polyester resin composition according to any one of claims 1 to 3 , wherein no crack is generated in the ultraviolet irradiation test. An automotive exterior molded article comprising the polyester resin composition according to any one of claims 1 to 4 .