JP2017043679A - Polyester-based resin composition and molded body comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester-based resin composition that has properties suitable for blow molding, is excellent in moldability during blow molding, and can produce a blow molded body having excellent impact resistance.SOLUTION: There is provided a polyester-based resin composition containing a polyester-based resin (A) having ethylene terephthalate as a main repeating unit and containing 2 to 20 mol% of 1,4-cyclohexanedimethanol as a copolymerization component and having intrinsic viscosity of 0.7 to 1.4, and a polyester block copolymer (B). The polyester-based resin composition contains 0.1 to 25 pts.mass of a polyester block copolymer (B) per 100 pts.mass of a polyester resin (A), and having melt tension measured at 260°C of 15 to 60 mN. In the polyester-based resin composition, the polyester block copolymer (B) comprises a crystalline aromatic polyester unit as a hard segment and an aliphatic polyether unit and/or an aliphatic polyester unit as a soft segment.SELECTED DRAWING: None

Description

  The present invention relates to a polyester resin composition containing a polyester resin copolymerized with 1,4-cyclohexanedimethanol and a polyester block copolymer, and a molded article comprising the same.

  Polyethylene terephthalate (PET) is excellent in mechanical properties, chemical stability, transparency, etc., is inexpensive, and is widely used as various sheets, films, containers, and the like. There are few concerns about residual monomers and harmful additives as in molded products, and hygiene and safety are high, so replacement with vinyl chloride resins is also progressing in various applications.

  In order to widely use PET for various purposes, it is necessary to have impact resistance. In particular, a container obtained from a sheet-like molded article, a blow molded article obtained by blow molding, and the like are required to have excellent impact resistance from the viewpoint of durability.

  Patent Document 1 describes a thermoplastic polymer composition comprising a thermoplastic polymer and a core-shell impact buffer. As thermoplastic polymers, polyesters such as PET, polybutylene terephthalate, and polylactic acid are also described.

  However, Patent Document 1 does not describe that a molded body is obtained by blow molding, and a molded body (such as a bottle) obtained by blow molding the thermoplastic polymer composition of Patent Document 1 has impact resistance. The improvement effect was insufficient.

  Patent Document 2 describes a resin composition obtained by adding a modified polyolefin or a modified olefin elastomer to PET. However, the resin composition described in Patent Document 2 is not considered to obtain a molded body by blow molding, and is intended to obtain a molded body having excellent impact resistance and heat resistance by injection molding. there were. For this reason, the resin composition described in Patent Document 2 requires a crystal nucleating agent, a (meth) acrylate copolymer, an ester plasticizer, and a fibrous reinforcing material, and is difficult to blow-mold. Even if blow molding is possible, the resulting molded body (bottle or the like) has an insufficient impact resistance improvement effect.

Patent Document 1: Japanese Patent Application Laid-Open No. 2012-126902 Patent Document 2: Japanese Patent Application Laid-Open No. 61-200159

  The present invention solves the above-mentioned problems, has a characteristic suitable for blow molding, has excellent moldability during blow molding, and can obtain a blow molded article having excellent impact resistance. Is to provide.

The inventors of the present invention have arrived at the present invention as a result of intensive studies in order to solve the above problems. That is, the gist of the present invention is the following (1) to (3).
(1) A polyester resin (A) containing ethylene terephthalate as a main repeating unit, 2 to 20 mol% of 1,4-cyclohexanedimethanol as a copolymerization component, and having an intrinsic viscosity of 0.7 to 1.4 The polyester block copolymer (B) and a polyester resin composition containing 0.1 to 25 mass of the polyester block copolymer (B) with respect to 100 mass parts of the polyester resin (A). A polyester-based resin composition containing a part and having a melt tension of 15 to 60 mN measured at 260 ° C.
(2) Melt flow rate (MFR-1) measured under conditions of 260 ° C. and 21.2N is 0.1 to 20 g / 10 min, and melt flow rate (MFR) measured under conditions of 260 ° C. and 130N -2) and the ratio (MFR-2 / MFR-1) of 10-20, the polyester-type resin composition as described in (1).
(3) A molded article comprising the polyester resin composition according to (1) or (2).

The polyester-based resin composition of the present invention contains a specific amount of a specific copolymerized polyester-based resin and a specific polyester block copolymer and has a performance suitable for blow molding, so that it has good moldability and impact resistance. It is possible to obtain a blow molded article excellent in the above.
In particular, by setting the melt flow rate value within a specific range, it is possible to obtain a blow molded article having characteristics particularly suitable for blow molding, good moldability and excellent impact resistance.
And since the molded object of this invention is formed using the polyester-type resin composition of this invention, it can be obtained with high productivity, it is excellent in impact resistance, and is used for various uses. Can be used.

Hereinafter, the present invention will be described in detail.
The polyester-based resin composition of the present invention is composed mainly of a polyester-based resin (A) containing ethylene terephthalate as a main repeating unit and 1,4-cyclohexanedimethanol as a copolymerization component and containing 2 to 20 mol%. is there.
The polyester resin (A) in the present invention has a copolymerization amount of 1,4-cyclohexanedimethanol of 2 to 20 mol%, preferably 2 to 18 mol%, more preferably 3 to 15 mol%. It is preferable that By copolymerizing an appropriate amount of 1,4-cyclohexanedimethanol, the crystallization speed of the polyester resin (A) can be adjusted to those suitable for molding methods such as injection molding, extrusion molding, and blow molding. A molded article having excellent impact properties can be obtained. And the impact resistance of the molded object obtained can be improved more by adding a proper quantity of the polyester block copolymer (B) mentioned later.

  When the copolymerization amount of 1,4-cyclohexanedimethanol is less than 2 mol%, the impact resistance improvement effect is poor, and even when the polyester block copolymer (B) is added, excellent impact resistance is imparted. Difficult to do. On the other hand, if the copolymerization amount of 1,4-cyclohexanedimethanol exceeds 20 mol%, the resin becomes amorphous, resulting in poor impact resistance. Also, drying at a high temperature and solid phase polymerization become difficult, and blocking tends to occur during high temperature drying and in a solid phase polymerization process.

  The glycol component in the polyester resin (A) is preferably 60 mol% or more of ethylene glycol, more preferably 70 mol% or more of ethylene glycol, and even more preferably 80 mol% or more of ethylene glycol. It is preferable. When the content of ethylene glycol is less than 60 mol%, the resulting polyester resin has poor crystallinity and heat resistance. On the other hand, when it exceeds 98 mol%, since the ratio of 1,4-cyclohexanedimethanol decreases, the above-mentioned effect due to containing 1,4-cyclohexanedimethanol becomes poor.

  The total amount of ethylene glycol and 1,4-cyclohexanedimethanol is preferably 70 mol% or more of all glycol components, and more preferably 80 mol% or more.

  Examples of glycol components other than ethylene glycol and 1,4-cyclohexanedimethanol include neopentyl glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexamethylenediol, diethylene glycol, and dimer. Ethylene oxide adducts of diol, bisphenol A or bisphenol S can be used.

  On the other hand, 60 mol% or more of the acid component is preferably terephthalic acid, and among them, the ratio of terephthalic acid is preferably 70 mol% or more, and more preferably 80 mol% or more. When the proportion of terephthalic acid is less than 60 mol%, the crystallinity of the resin is lowered and the resin tends to be amorphous.

  Examples of dicarboxylic acid components other than terephthalic acid include phthalic acid, phthalic anhydride, isophthalic acid, naphthalenedicarboxylic acid, adipic acid, 1,4-cyclohexanedicarboxylic acid, sebacic acid, dimer acid, and the like. These acids may be used in combination, or ester-forming derivatives of these acids may be used.

The polyester resin (A) of the present invention has an intrinsic viscosity of 0.7 to 1.4, preferably 0.75 to 1.3. Furthermore, when using it for a direct blow molding use, it is preferable that it is 0.9-1.3.
The intrinsic viscosity is measured at a temperature of 20 ° C. using an equal mass mixture of phenol and ethane tetrachloride as a solvent.

  When the intrinsic viscosity is less than 0.7, since the viscosity of the resin is low, the drawdown of the parison becomes large at the time of blow molding, and the molding itself becomes difficult. Above all, the parison drawdown becomes remarkable during direct blow molding. Moreover, even if it can obtain a molded object, it will be inferior to impact resistance. On the other hand, when the intrinsic viscosity exceeds 1.4, it is necessary to raise the molding temperature, the thermal decomposition of the resin is promoted, and the impact resistance and color tone of the resulting molded article are deteriorated. In addition, the obtained molded product has uneven thickness, and the impact resistance is also deteriorated.

  The polyester resin (A) is a melt flow rate (MFR) (measured at 260 ° C. and 21.2 N according to ASTM D1238) from the viewpoint of compatibility with the polyester block copolymer (B) described later and the improvement of impact strength. Is preferably 0.1 to 20 g / 10 min, and more preferably 0.5 to 10 g / 10 min.

Furthermore, the polyester-based resin (A) of the present invention preferably has a carboxyl end group concentration of 20 equivalent / t or less, more preferably 19 equivalent / t or less. By setting the carboxyl end group concentration of the polyester resin (A) to 20 equivalent / t or less, thermal decomposition does not occur during processing, and stable molding becomes possible. Moreover, it becomes possible to obtain the molded object excellent also in durability.
When the carboxyl end group concentration exceeds 20 equivalent / t, thermal decomposition of the resin occurs due to thermal history during processing. For this reason, since a molded object will be inferior to a physical property or will cause appearance deterioration, such as coloring, it is unpreferable. Moreover, since it is also inferior to durability, it is not preferable.

  Next, the polyester block copolymer (B) will be described. The polyester block copolymer (B) of the present invention comprises a hard segment (b1) mainly composed of crystalline aromatic polyester units and a soft segment (b2) mainly composed of aliphatic polyether units and / or aliphatic polyester units. It will be.

  The hard segment (b1) of the polyester block copolymer (B) is a crystalline aromatic polyester mainly formed from an aromatic dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof. Specific examples of the group dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, anthracene dicarboxylic acid, diphenyl-4,4′-dicarboxylic acid, Examples include diphenoxyethane dicarboxylic acid, 4,4′-diphenyl ether dicarboxylic acid, 5-sulfoisophthalic acid, and sodium 3-sulfoisophthalate. Although aromatic dicarboxylic acid is mainly used, if necessary, a part of the aromatic dicarboxylic acid may be converted to alicyclic dicarboxylic acid such as 1,4-cyclohexanedicarboxylic acid, cyclopentanedicarboxylic acid, 4,4′-dicyclohexyldicarboxylic acid, etc. Alternatively, it may be substituted with an aliphatic dicarboxylic acid such as adipic acid, succinic acid, oxalic acid, sebacic acid, dodecanedioic acid, and dimer acid. Of course, ester-forming derivatives of dicarboxylic acids such as lower alkyl esters, aryl esters, carbonates, and acid halides can be used equally.

  Specific examples of the diol include diols having a molecular weight of 400 or less, for example, aliphatic diols such as 1,4-butanediol, ethylene glycol, trimethylene glycol, pentamethylene glycol, hexamethylene glycol, neopentyl glycol, decamethylene glycol, , 1-cyclohexanedimethanol, 1,4-dicyclohexanedimethanol, alicyclic diols such as tricyclodecane dimethanol, and xylylene glycol, bis (p-hydroxy) diphenyl, bis (p-hydroxy) diphenylpropane, 2,2′-bis [4- (2-hydroxyethoxy) phenyl] propane, bis [4- (2-hydroxyethoxy) phenyl] sulfone, 1,1-bis [4- (2-hydroxyethoxy) phenyl] cyclohexane Aromatic diols such as 4,4′-dihydroxy-p-terphenyl and 4,4′-dihydroxy-p-quarterphenyl are preferred, and such diols may be ester-forming derivatives such as acetyl compounds, alkali metal salts, etc. It can also be used in the form.

  Two or more of these dicarboxylic acids, derivatives thereof, diol components and derivatives thereof may be used in combination. An example of a preferable hard segment (b1) is a polybutylene terephthalate unit derived from terephthalic acid and / or dimethyl terephthalate and 1,4-butanediol. Also preferred are those composed of polybutylene terephthalate units derived from terephthalic acid and / or dimethyl terephthalate, and polybutylene isophthalate units derived from isophthalic acid and / or dimethyl isophthalate and 1,4-butanediol. .

  The soft segment (b2) of the polyester block copolymer (B) used in the present invention is an aliphatic polyether and / or an aliphatic polyester. Aliphatic polyethers include poly (ethylene oxide) glycol, poly (propylene oxide) glycol, poly (trimethylene oxide) glycol, poly (tetramethylene oxide) glycol, poly (hexamethylene oxide) glycol, and a combination of ethylene oxide and propylene oxide. And a polymer, an ethylene oxide addition polymer of poly (propylene oxide) glycol, a copolymer glycol of ethylene oxide and tetrahydrofuran, and the like. Examples of the aliphatic polyester include poly (ε-caprolactone), polyenanthlactone, polycaprylolactone, polybutylene adipate, and polyethylene adipate. Among these aliphatic polyethers and / or aliphatic polyesters, poly (tetramethylene oxide) glycol, ethylene oxide adduct of poly (propylene oxide) glycol, copolymer glycol of ethylene oxide and tetrahydrofuran, poly (ε-caprolactone) , Polybutylene adipate, and polyethylene adipate are preferred. Among these, poly (tetramethylene oxide) glycol, ethylene oxide adduct of poly (propylene oxide) glycol, copolymer glycol of ethylene oxide and tetrahydrofuran, and poly (ε -Caprolactone) is preferred.

  In addition, the number average molecular weight of these soft segments is preferably about 300 to 6000 in the copolymerized state. The copolymerization amount of the soft segment (b2) of the polyester block copolymer (B) used in the present invention is preferably 15 to 65% by mass, and more preferably 15 to 60% by mass.

  In the polyester block copolymer (B) in the present invention, as a preferable combination of the hard segment (b1) and the soft segment (b2), polybutylene terephthalate is used for the hard segment (b1), and the soft segment (b2) is used. Examples include those using poly (tetramethylene oxide) glycol, and those using polybutylene terephthalate for the hard segment (b1) and poly (ε-caprolactone) for the soft segment (b2).

Furthermore, the polyester block copolymer (B) in the present invention may contain other components in addition to the hard segment (b1) and the soft segment (b2) as long as the effect is not impaired.
The other component is preferably a styrene elastomer composed of an aromatic vinyl-conjugated diene block copolymer from the viewpoint of dispersibility and flexibility. As the styrene-based elastomer, styrene / butadiene / styrene (SBS), styrene / butadiene / butylene / styrene (SBBS), and styrene / ethylene / butylene / styrene (SEBS) are preferable, and among them, SEBS is more preferable from the viewpoint of compatibility.
The content of such other components is preferably 60% by mass or less in the polyester block copolymer (B), preferably 50% by mass or less, and more preferably 40% by mass or less. It is preferable. When it exceeds 60 mass%, since the impact resistance improvement effect of a polyester block copolymer (B) becomes small, it is unpreferable.

  Commercially available products of such a polyester block copolymer (B) include "Primalloy AP series" manufactured by Mitsubishi Chemical Corporation, "Perprene" manufactured by Toyobo Co., Ltd., "Hytrel" manufactured by Toray DuPont, and "Esthetic" manufactured by Aron Kasei Co., Ltd. Lar "etc.

  The polyester block copolymer (B) has a melt flow rate (MFR) (measured at 230 ° C. and 2.16 kg load according to ASTM D1238) from the viewpoint of compatibility with the polyester resin (A) and improvement of impact strength. It is preferably 0.01 to 40 g / 10 minutes, more preferably 0.05 to 30 g / 10 minutes, and even more preferably 0.1 to 20 g / 10 minutes.

  The polyester block copolymer (B) used in the present invention can be produced by a known method. Specific examples thereof include, for example, a method of transesterifying a lower alcohol diester of a dicarboxylic acid, an excessive amount of a low molecular weight glycol and a low melting point polymer segment component in the presence of a catalyst, and polycondensing the resulting reaction product, and Any method such as a method in which a dicarboxylic acid, an excess amount of glycol and a low melting point polymer segment component are esterified in the presence of a catalyst and the resulting reaction product is polycondensed may be used.

  By adding the above polyester block copolymer (B) to the polyester resin (A), the impact resistance of the resulting resin composition can be remarkably improved. Furthermore, when adding inorganic particles, such as a pigment, in a resin composition, there exists an effect which improves the dispersibility of these inorganic particles. For this reason, usually, when the dispersibility of the inorganic particles contained in the resin composition is poor, the impact strength is reduced, but the resin composition of the present invention is a case containing a relatively large amount of inorganic particles. Also, since the inorganic particles are excellent in dispersibility, they have good impact resistance.

  The content of the polyester block copolymer (B) needs to be 0.1 to 25 parts by mass with respect to 100 parts by mass of the polyester resin (A), and in particular, 0.5 to 20 parts by mass. It is preferable that it is 0.5 to 15 parts by mass. When content is less than 0.1 mass part, the impact strength of the resin composition obtained cannot fully be improved. In addition, the effect of improving the dispersibility of the inorganic particles is poor. On the other hand, when it exceeds 25 mass parts, compatibility with a polyester-type resin (A) may fall, and the dispersibility of a polyester block copolymer (B) may worsen. For this reason, the moldability is deteriorated, blow molding is particularly difficult, and the resulting molded product is not preferable because it may have uneven thickness or poor appearance.

  Next, the polyester resin composition of the present invention has a melt tension value measured at 260 ° C. of 15 to 60 mN, preferably 15 to 50 mN, and more preferably 17 to 35 mN. When the melt tension is less than 15 mN, the viscosity at the time of blow molding is not sufficiently high, which causes drawdown and the like, causing deterioration of the appearance and causing thickness unevenness. On the other hand, when the melt tension exceeds 60 mN, the flowability deteriorates when blow molding is performed, and thus the molding temperature needs to be raised. For this reason, thermal decomposition of the resin occurs, which causes coloring and appearance deterioration.

  The melt tension in the present invention is measured as follows. The measurement is performed using a Capillograph 1C manufactured by Toyo Seiki Seisakusho (cylinder inner diameter 9.55 mm, orifice inner diameter 1.0 mm, length 10.0 mm). First, the set temperature of the cylinder and the orifice is set to 260 ° C., the polyester resin composition (measurement sample) is filled in the cylinder, left for 5 minutes, and then the molten resin at 260 ° C. is set at a piston speed of 10 mm / min. Extruded into a strand from the orifice. The strand is wound while passing through a circular guide of a tension detection pulley having a lower diameter of 40 mm, and a load applied to the circular guide is detected by a tensiometer. The winding speed is gradually increased, and the tension at which the strand breaks (that is, the maximum measurable tension) is taken as the melt tension.

  Furthermore, the polyester resin composition of the present invention preferably has a melt flow rate (MFR-1) of 0.1 to 20 g / 10 minutes measured under conditions of 260 ° C. and a load of 21.2 N, It is preferable that it is 0.5-10 g / 10min. If the MFR-1 is outside this range, it does not have fluidity suitable for blow molding, the moldability is deteriorated, and the resulting blow molded product tends to have uneven thickness.

Moreover, it is preferable that ratio (MFR-2 / MFR-1) with the melt flow rate (MFR-2) measured on condition of 260 degreeC and load 130N is 10-20, and it is 11-18. Is more preferable, and it is further more preferable that it is 12-15.
The melt flow rate in the present invention is measured according to JIS K-7210.

  The value of MFR-2 / MFR-1 is also a measure of the molecular weight distribution and linear branching of the resin composition. The higher the value of MFR-2 / MFR-1, the wider the molecular weight distribution or the higher the linear branching. It shows that. When the value of MFR-2 / MFR-1 is less than 10, the fluidity is too high, and it is not preferable because spots are easily formed in the blow molding. On the other hand, when the value of MFR-2 / MFR-1 exceeds 20, the flowability is poor, so the molding temperature needs to be increased. Thereby, the resin is easily decomposed, and the possibility of deterioration of the appearance such as coloring and gelation is increased, which is not preferable. In addition, an increase in the carboxylic acid terminal of the resin composition due to decomposition is not preferable because durability of the resulting molded article is deteriorated.

  And in order to satisfy the said range which prescribes | regulates the melt tension and MFR ratio of a polyester-type resin composition by this invention, the melt flow of a polyester-type resin (A) and a polyester block copolymer (B) It is preferable to adjust the rate to an appropriate value or add a fatty acid ester or a hindered phenol antioxidant to the polyester resin composition.

  The content of the fatty acid ester and the hindered phenol antioxidant in the polyester resin composition is preferably 0.01 to 1.0% by mass, and more preferably 0.05 to 1.0% by mass. Is preferred.

  Specific examples of fatty acid esters include beeswax (mixture based on myricyl palmitate), stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmitate, glycerin monostearate, glycerin distearate, Examples thereof include glycerin tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate, dipentaerythritol hexastearate and the like. Among these, glycerin monostearate, pentaerythritol tetrastearate, and dipentaerythritol hexastearate are preferable.

  Examples of hindered phenol antioxidants include 2,6-di-t-butyl-4-methylphenol and n-octadecyl-3- (3 ′, 5′-di-t-butyl-4′-hydroxy. Phenyl) propionate, tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane, tris (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate, 4,4′-butylidenebis- (3-methyl-6-tert-butylphenol), triethylene glycol-bis [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate], 3,9- Bis {2- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1'-dimethylethyl} -2, , 8,10-tetraoxaspiro [5,5] undecane, etc. are used, but tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate in terms of effect and cost. Methane is preferred.

  Further, in the polyester resin composition of the present invention, in addition to the above-described antioxidants, examples of coloring inhibitors include phosphorous acid, phosphoric acid, trimethyl phosphite, triphenyl phosphite, and tridecyl phosphite. Phosphorus compounds such as phyto, trimethyl phosphate, tridecyl phosphate and triphenyl phosphate can be used, and these phosphorus compounds may be used alone or in combination of two or more. In addition, additives such as a cobalt compound such as cobalt acetate, a manganese compound such as manganese acetate, an anthraquinone dye compound, and a copper phthalocyanine compound may be contained in order to suppress coloring due to thermal decomposition of the polyester resin.

  The total content of the polyester resin (A) and the polyester block copolymer (B) in the polyester resin composition of the present invention is preferably 80% by mass or more, and more preferably 90% by mass or more. More preferably, it is 95% by mass or more.

  The polyester-based resin composition of the present invention may contain other resin components as long as the effects of the present invention are not impaired. Examples of thermoplastic resins include polyethylene glycol or derivatives thereof, polyvinyl alcohol, polyvinyl acetate, nylon and other polyamides, polyethylene, polypropylene, polyvinyl chloride, polytetrafluoroethylene and other fluorocarbon resins, cellulose resins, acrylic resins, acrylonitrile -Butadiene-styrene or acrylonitrile-thermoplastic resins such as styrene, polycarbonate, polyvinyl alcohol, polyoxymethylene, polyformaldehyde, polyacetal or the like, phenol-formaldehyde resins such as graft, resol and novolak, and copolymers thereof, and mixtures thereof Etc. Examples of the thermosetting resin include polyurethane, silicone, fluorosilicone, phenol resin, melamine resin, melamine / formaldehyde, urea / formaldehyde and copolymers thereof, and mixtures thereof.

  In addition, pigments, heat stabilizers, weathering agents, flame retardants, plasticizers, lubricants, mold release agents, antistatic agents, etc. are added to the polyester resin composition of the present invention as long as the effects of the present invention are not impaired. May be. As the heat stabilizer, for example, phosphorus compounds, hindered amines, sulfur compounds, copper compounds, alkali metal halides, or mixtures thereof can be used. These additives are generally added during melt kneading or polymerization.

The polyester resin composition of the present invention may contain a foaming agent as shown below, and the molded product of the present invention may be made into a blown blow molded product by foam blow molding.
Examples of the foaming agent include pyrolysis-type organic compounds containing decomposable groups such as azo, N-nitroso, heterocyclic nitrogen and sulfonyl hydrazide groups, and inorganic compounds such as ammonium carbonate and sodium hydrogen carbonate. Can be mentioned. Specific examples thereof include azodicarbonamide, azobisisobutyronitrile, azocyclohexylnitrile, diazoaminobenzene, dinitrosopentamethylenetetramine, N, N′-dimethyl-N, N′-dinitrosotephthalamide, benzenesulfonyl Hydrazide, 4,4′-oxy-bis (benzenesulfonyl) hydrazide, diphenylsulfone-3,3′-disulfonylhydrazide, 4-toluenesulfonyl hydrazide, 4,4′-oxy-bis (benzenesulfonyl) semicarbazide, 4- Examples include toluenesulfonyl semicarbazide, barium azodicarboxylate, 5-phenyltetrazole, trihydrazinotriazine, 4-toluenesulfonyl azide, 4,4′-diphenyldisulfonyl azide, and the like.

  As the foaming agent, gaseous agents such as gaseous fluorocarbon, nitrogen, carbon dioxide, air, helium, and argon, and those that are liquid at ordinary temperatures such as liquid fluorocarbon and pentane can be used.

  Next, the manufacturing method of the polyester-type resin composition of this invention is demonstrated. The polyester resin (A) in the present invention is preferably obtained through an esterification reaction, a melt polymerization reaction, and a solid phase polymerization reaction step. Only by the esterification reaction and the melt polymerization reaction, it becomes difficult to obtain a polyester resin having a target intrinsic viscosity. Even if it is obtained, the reaction time of the melt polymerization reaction becomes longer, and the resulting polyester resin has a poor color tone. And the polyester-type resin (A) of this invention can be obtained by making the process and conditions in a solid-phase polymerization reaction into a specific thing.

  The polyester resin composition of the present invention can be obtained by melt-kneading the polyester resin (A) and the polyester block copolymer (B). The kneading method is not particularly limited, and for example, a melt kneading method that is industrially simplest can be adopted. A general extruder can be used for melt-kneading, and it is preferable to use a twin-screw extruder for improving the kneading state. When supplying the polyester-based resin (A) and the polyester block copolymer (B) to the extruder, a mixture obtained by dry blending all raw materials in advance may be supplied to one hopper, or two hoppers. The respective resins may be charged and supplied while being quantitatively determined with a screw or the like under the hopper.

  At this time, regarding the addition method of the polyester block copolymer (B), a master batch pellet in which the polyester block copolymer (B) is added at a high concentration in the polyester resin (A) is prepared. It is preferable to employ a method of obtaining a polyester resin composition by diluting the pellet with the polyester resin (A). By adopting such a method, the cost of obtaining a molded body can be suppressed, and at the same time, the thermal history of the molded body can be reduced, so that the thermal degradation of the polyester resin can be suppressed, and the viscosity and tension can be reduced. Can be suppressed. Thereby, it is excellent in molding processability, and the molded object obtained becomes a molded object more excellent in impact resistance, and can be excellent in color tone.

  In such a master batch pellet, the content of the polyester block copolymer (B) is preferably 3 to 40 parts by mass, more preferably 4 to 35 parts by mass with respect to 100 parts by mass of the polyester resin (A). Part is preferable, and 5 to 30 parts by mass is more preferable. When the content of the polyester block copolymer (B) is less than 3 parts by mass, the amount of the master batch pellet used in obtaining the resin composition of the present invention increases, and the polyester block copolymer (B) is increased. It cannot be said to be a master batch pellet contained in the concentration. On the other hand, when the content exceeds 40 parts by mass, the operability at the time of preparing the master batch pellet is lowered, the dispersibility of the polyester block copolymer (B) is lowered, and the resulting master batch pellet is likely to have uneven concentration. Become.

Next, after manufacturing the masterbatch pellet of the present invention as described above, a method of manufacturing the polyester resin composition of the present invention by diluting with the polyester resin (A) will be described.
First, the manufacturing method of the masterbatch pellet of this invention is demonstrated. In the extruder, the polyester resin (A) and the polyester block copolymer (B) are added and melt-kneaded. At this time, melt kneading is performed with a single screw extruder or a twin screw extruder, the cylinder temperature is 250 to 290 ° C., the die temperature is 260 to 290 ° C., the resin composition is melt kneaded and extruded, and the strand is cooled. The method of cutting into pellet size is preferable. The extruder to be used is preferably a twin screw extruder because of the kneading ability. Further, the addition method is not particularly limited, such as a method of adding the polyester block copolymer (B) from another feeder, a method of dry blending and adding from the hopper, etc., but the concentration can be measured accurately and dispersion unevenness can be obtained. Since it can suppress, it is preferable to measure and add with a separate feeder, respectively.

And the polyester-type resin composition of this invention is polyester-type resin (A) so that a polyester block copolymer (B) may become a desired density | concentration using the masterbatch pellet obtained as mentioned above. It can be obtained by dilution. Specifically, after the master batch pellet and the polyester resin (A) are dry blended, it is preferable to perform melt kneading with a single screw extruder or a twin screw extruder.
In that case, it is preferable that the ratio of a masterbatch pellet and a polyester-type resin (A) is 5 / 95-20 / 80 mass parts.

  As described above, the polyester resin composition of the present invention is suitable for blow molding. However, even if an injection molding or stretching method is adopted, a molded body excellent in impact resistance (an injection molded body, a sheet). , Film, etc.) can be obtained.

  Next, the molded article of the present invention is formed using the polyester resin composition of the present invention, and among them, a blow molded article is preferable. The blow molded product of the present invention can be manufactured using a general-purpose direct blow molding machine or stretch blow molding machine, and the temperature of each part of the cylinder and the nozzle of the molding machine is in the range of 230 to 280 ° C. Is preferred.

  The blow molded article of the present invention may be a single-layer blow molded article formed using only the resin composition of the present invention, or at least a part of the resin composition of the present invention is used. It may be a blow molded article having a multilayer structure.

Next, the present invention will be specifically described using examples. The measurement and evaluation methods for various characteristic values in the examples are as follows.
(1) Intrinsic Viscosity of Polyester Resin (A) It was determined from the solution viscosity measured at a temperature of 20 ° C. using a mixed solvent of equal mass of phenol and ethane tetrachloride.
(2) Composition of resin composition The obtained polyester resin composition was dissolved in a mixed solvent having a volume ratio of deuterated hexafluoroisopropanol and deuterated chloroform of 1/20, and LA-manufactured by JEOL Ltd. 1H-NMR was measured with a 400-type NMR apparatus, and the type and content of the copolymerization component were determined from the integrated intensity of the proton peak of each component of the obtained chart.
(3) Melt tension of resin composition It measured by the said method.
(4) Melt flow rate (MFR) of resin composition
The obtained polyester resin composition (melted and kneaded with a twin screw extruder, cut into pellets and dried with hot air) was subjected to 260 ° C., 21.2N (MFR-1) and 130N (according to JIS K-7210). It was measured under MFR-2) conditions.

(5) Impact resistance (Charpy impact strength)
The obtained polyester resin composition was put into a NEX110 type injection molding machine manufactured by Nissei Resin Co., Ltd., with a cylinder temperature of 260 ° C. and a mold surface temperature of 40 ° C., a test piece for measuring general physical properties (ISO type) and a 2 mm thick plate 90 mm in length and 50 mm in width).
Charpy impact strength was measured according to ISO 179-1 using the obtained test piece for general physical property measurement (ISO type) having a V-shaped cut as a test sample.
(6) Impact resistance (DuPont impact strength)
Using the 2 mm thick plate obtained in (5) with a hole having a diameter of 2.5 mm as the measurement sample, impact resistance according to JIS K5600-5-3 “6. DuPont” (Weight drop resistance) was measured. The impact resistance was evaluated based on the value of 50% fracture energy obtained by the measurement.

(7) Direct blow moldability The thickness of the body part of the obtained direct blow molded body (100 samples) was measured, and the thickness difference between the thickest part and the thinnest part was up to 0.30 mm. The sample was accepted and the number of samples accepted was shown. A sample having 90 or more acceptable samples was evaluated as “◯”, and a sample having less than 90 samples as “×”.
(8) Stretch blow moldability The thickness of the body of the obtained stretch blow molded body (100 samples) is measured, and the difference between the thickness of the thickest part and the thinnest part is up to 30 μm. , Showed the number of samples passed. A sample having 90 or more acceptable samples was evaluated as “◯”, and a sample having less than 90 samples as “×”.

Resins used in the following examples and comparative examples are as follows.
Polyester resin (A)
A-1: It was produced by the method shown in Production Example 1. (1,4-cyclohexanedimethanol copolymerization amount: 6 mol%, intrinsic viscosity 1.13)
A-2: Prepared by the method shown in Production Example 2. (Copolymerization amount of 1,4-cyclohexanedimethanol: 10 mol%, intrinsic viscosity 1.11)
A-3: Prepared by the method shown in Production Example 3. (Copolymerization amount of 1,4-cyclohexanedimethanol: 8 mol%, limiting viscosity 1.12)
a-1: Prepared by the method shown in Production Example 4. (1,4-cyclohexanedimethanol copolymerization amount: 1 mol%, intrinsic viscosity 1.11)
a-2: Prepared by the method shown in Production Example 5. (1,4-cyclohexanedimethanol copolymerization amount: 22 mol%, intrinsic viscosity 0.66)
a-3: Prepared by the method shown in Production Example 6. (Isophthalic acid copolymerization amount: 6 mol%, intrinsic viscosity 1.13)

Polyester block copolymer (B)
B-1: Block copolymer of polybutylene terephthalate and poly (tetramethylene oxide) glycol ["Hytrel 5077" manufactured by Toray DuPont, MFR: 1.6 g / 10 min]
B-2: Mixture of block copolymer of polybutylene terephthalate and poly (tetramethylene oxide) glycol and styrene elastomer ["Esteral ES-A60NX" manufactured by Aron Kasei Co., Ltd., MFR: 0.3 g / 10 min, styrene (Elastomer content is 50% by mass)

Other elastomers (X)
X-1: SEBS [Aron Kasei Co., Ltd. “AR-815C”, MFR: 1.0 g / 10 min]
X-2: Core-shell type impact resistance improver [core layer component: butadiene rubber, shell layer component: (meth) methyl acrylate polymer “Metabrene C-223” manufactured by Mitsubishi Rayon Co., Ltd.]

Production Example 1: Preparation of A-1 A slurry of terephthalic acid (TPA) and ethylene glycol (EG) (TPA / EG molar ratio = 1 / 1.6) was supplied to an esterification reactor, and the temperature was 250 ° C. and the pressure was The reaction was carried out under the condition of 50 hPa to obtain a reaction product (number average degree of polymerization: 5) having an esterification reaction rate of 95%.
59.4 parts by mass of a reaction product of TPA and EG were charged into a polymerization reactor, followed by 3.8 parts by mass of 1,4-cyclohexanedimethanol, 0.008 parts by mass of germanium dioxide as a polymerization catalyst, and 0. 004 parts by mass, 0.12 parts by mass of a hindered phenolic antioxidant (manufactured by ADEKA: Adeka Stub AO-60) were added, respectively, and the reactor was evacuated and after 60 minutes, the final pressure was 0.9 hPa and the temperature was 280 ° C. A melt polymerization reaction was performed for 4 hours to obtain a prepolymer of a copolyester. The intrinsic viscosity of this prepolymer was 0.66.
Subsequently, the prepolymer was continuously supplied to a crystallization apparatus and crystallized at 150 ° C., then supplied to a dryer, dried at 160 ° C. for 8 hours, then sent to a preheater and heated to 190 ° C. Then, it was supplied to a solid phase polymerization machine, and a solid phase polymerization reaction was carried out at 190 ° C. for 50 hours under nitrogen gas to obtain a polyester resin (A-1).

Production Examples 2 to 5: Preparation of (A-2), (A-3), (a-1), and (a-2) The copolymerization amount of 1,4-cyclohexanedimethanol is the value shown in Table 1. A prepolymer of a copolyester was obtained in the same manner as in Production Example 1 except that the composition was changed. Then, using the obtained prepolymer, a solid-state polymerization reaction was performed in the same manner as in Production Example 1, and polyester resins (A-2), (A-3), (a-1), and (a-2) were changed. Obtained.

Production Example 6: Production of a-3 A slurry of terephthalic acid (TPA) and ethylene glycol (EG) (TPA / EG molar ratio = 1 / 1.6) was supplied to the esterification reactor, and the temperature was 250 ° C. and the pressure was The reaction was carried out under the condition of 50 hPa to obtain a reaction product (number average degree of polymerization: 5) having an esterification reaction rate of 95%.
In another esterification reaction can, a slurry (IPA / EG molar ratio = 1 / 3.1) composed of isophthalic acid (IPA) and ethylene glycol is charged, and the esterification reaction is performed at a temperature of 200 ° C. for 3 hours. A reaction solution of ethylene glycol was obtained.
55.5 parts by mass of a reaction product of TPA and EG were charged into a polymerization reactor, followed by 6.1 parts by mass of a reaction solution of isophthalic acid and ethylene glycol, 0.008 parts by mass of germanium dioxide as a polymerization catalyst, and 0 parts of cobalt acetate. .004 parts by mass, 0.12 parts by mass of a hindered phenol-based antioxidant (manufactured by AEDKA: Adeka Stub AO-60) were added, and the reactor was evacuated, and after 60 minutes, final pressure 0.9 hPa, temperature 280 ° C. The polyester was subjected to a melt polymerization reaction for 4 hours to obtain a polyester resin (a-3).

  Table 1 shows the compositions and characteristic values of the obtained polyester resins (A-1) to (A-3) and (a-1) to (a-3).

Production Example 7 Production of Master Batch Pellet of B-1 Using a twin screw extruder (TEM37BS type manufactured by Toshiba Machine Co., Ltd.), 100 parts by mass of a polyester resin (A-1) and a polyester block copolymer (B-1) ) 25 parts by mass was dry blended and supplied from the root supply port of the extruder, and extrusion was carried out while venting under the conditions of a kneading temperature of 260 ° C., a screw rotation speed of 150 rpm, and a discharge of 20 kg / h. The resin composition discharged from the tip of the extruder was cut into pellets and dried in hot air at 85 ° C. for 12 hours, and used as a B-1 master batch pellet for various molded body preparations.

Example 1
Using a twin screw extruder (TEM37BS type manufactured by Toshiba Machine Co., Ltd.), 100 parts by mass of the polyester resin (A-1) and 0.5 parts by mass of the polyester block copolymer (B-1) are dry blended and extruded. Extrusion was carried out while venting was effected under the conditions of a kneading temperature of 260 ° C., a screw rotation speed of 150 rpm, and a discharge of 20 kg / h. The resin composition discharged from the tip of the extruder was cut into pellets. The pellet obtained was dried in hot air at 85 ° C. for 12 hours and used as a polyester resin composition for the production of various molded articles.
In addition, using a direct blow molding machine (manufactured by Tahara), the polyester-based resin composition is extruded at an extrusion temperature of 260 ° C. to form a cylindrical parison, which is sandwiched between molds while the parison is in a softened state, The bottom was formed and blown to form a bottle. At this time, when the parison diameter was 3 cm and the length became 25 cm, the bottom was formed and blow-molded to obtain a 500 cc hollow container (direct blow molded body).
Furthermore, the polyester-based resin composition was manufactured by an injection molding machine (Nissei ASB Co., Ltd.) in which each part of the cylinder and nozzle temperature were set to 260 ° C., screw rotation speed 100 rpm, injection time 10 seconds, cooling time 10 seconds, and mold temperature 15 ° C. A preform was molded using ASB-50TH type. Next, this preform was stretch blow molded at a blow pressure of 2 MPa in an atmosphere of 100 ° C., and a cylindrical bottle (a hollow container having an internal volume of 150 cc; stretched; an average thickness of 300 μm, an inner diameter of 3.5 cm, and a height of 15 cm) A blow molded article) was obtained.

Examples 2-7, 9-15, Comparative Examples 1-12
As shown in Table 1, a polyester resin composition was obtained in the same manner as in Example 1 except that the types and ratios of the polyester resin (A) and the polyester block copolymer (B) were changed. In Comparative Examples 7 to 12, a polyester resin composition was obtained in the same manner as in Example 1 except that the polyester block copolymer (B) was not added.
Using the obtained polyester resin composition, a direct blow molded article and a stretch blow molded article were obtained in the same manner as in Example 1.

Example 8
B-1 produced in the polyester resin (A-1) and Production Example 7 so that the ratio of the polyester resin (A-1) and the polyester block copolymer (B-1) is as shown in Table 1. A polyester resin composition was obtained in the same manner as in Example 1 except that the master batch pellet was driven.
Using the obtained polyester resin composition, a direct blow molded product and a stretch blow molded product were obtained in the same manner as in Example 1.

Table 2 shows the evaluation results of the polyester resin compositions and molded articles obtained in Examples 1 to 15 and Comparative Examples 1 to 12.

  As is clear from Table 2, the polyester-based resin compositions obtained in Examples 1 to 15 have excellent impact resistance, and both direct blow molding and stretch blow molding can be performed well. It was possible to obtain a molded article with less thickness unevenness and excellent impact resistance.

On the other hand, the polyester resin composition obtained in Comparative Example 1 had too much content of the polyester block copolymer (B), and the MFR-2 / MFR-1 value exceeded 20, The fluidity during molding was poor. Therefore, since the molding was carried out at a higher molding temperature, the resin was thermally decomposed, the moldability was deteriorated, and the number of molded products having thickness spots increased. Further, the obtained molded body was colored. Further, the obtained molded article was inferior in dispersibility and poor in appearance. The polyester resin composition obtained in Comparative Example 2 was inferior in impact resistance because the content of the polyester block copolymer (B) was too small.
The polyester-based resin composition obtained in Comparative Example 3 was inferior in impact resistance because another elastomer was added instead of the polyester block copolymer (B). The polyester-based resin composition obtained in Comparative Example 4 was inferior in impact resistance because another elastomer was added instead of the polyester block copolymer (B). Furthermore, since the value of the melt tension was less than 15 mN, drawdown occurred during blow molding, and the resulting molded product was uneven in thickness.
The polyester resin composition obtained in Comparative Example 5 was inferior in impact resistance because the amount of 1,4-cyclohexanedimethanol copolymerization of the polyester resin (A) was small. The polyester-based resin composition obtained in Comparative Example 6 has too much copolymerization amount of 1,4-cyclohexanedimethanol in the polyester-based resin (A), and solid-phase polymerization cannot be performed, so that the melt tension becomes low, Drawdown occurred during blow molding, and the resulting molded product was uneven in thickness.
In Comparative Examples 7-12, since only the polyester-based resin was used and the polyester block copolymer (B) was not used, all the obtained molded articles were inferior in impact resistance.

Claims (3)

Polyester resin (A) having ethylene terephthalate as the main repeating unit, 1,4-cyclohexanedimethanol as a copolymerization component, 2-20 mol%, and intrinsic viscosity of 0.7-1.4, and polyester block It is a polyester resin composition containing a copolymer (B), and contains 0.1 to 25 parts by mass of the polyester block copolymer (B) with respect to 100 parts by mass of the polyester resin (A). The polyester-type resin composition characterized by the melt tension measured at 260 degreeC being 15-60 mN. The melt flow rate (MFR-1) measured at 260 ° C and 21.2N is 0.1 to 20 g / 10 min, and the melt flow rate (MFR-2) measured at 260 ° C and 130N. The polyester-based resin composition according to claim 1, wherein the ratio (MFR-2 / MFR-1) to is 10-20. The molded object which consists of a polyester-type resin composition of Claim 1 or 2.