JPWO2015093453A1 - Polyester resin composition and molded article obtained using the same - Google Patents

Abstract

A polyester resin composition containing a copolyester resin (A) and a carbodiimide compound (B), wherein the mass ratio (A / B) of the copolyester resin (A) and the carbodiimide compound (B) is from 10/90 to A polyester resin composition characterized by being 85/15.

Description

  The present invention relates to a polyester resin composition containing a copolyester resin and a carbodiimide compound.

  Molded articles formed from a polyester resin such as a polyethylene terephthalate film (PET film) and a polyethylene terephthalate bottle (PET bottle) are excellent in transparency and heat resistance, and thus are used in various packaging and industrial applications. In order to suppress hydrolysis of the polyester resin, carbodiimide compounds have been widely used as additives for polyester resins.

  The carbodiimide compound used as an additive has been used which has been pressed into a pellet to improve handling. However, since the carbodiimide compound is inferior in dispersibility and affinity to the polyester resin and is not compatible as a result, the polyester resin molded product obtained by adding the carbodiimide compound may lose transparency. The hydrolysis resistance could not be sufficiently improved. Further, in the production of a PET film, the film may be broken at the time of stretching, or in a produced PET bottle, a carbodiimide compound may cause gel or granular unmelted material.

In order to improve the compatibility of the carbodiimide compound, there is a method in which a master batch in which a carbodiimide compound is contained in a thermoplastic resin at a high concentration is prepared and added at the time of melt molding of a polyester resin (for example, patent document). 1).
In the production of PET films and the like, master batch pellets containing a carbodiimide compound may be used in order to increase the durability against hydrolysis.

JP 2013-49790 A

  In the production of PET films and the like, in order to further improve the compatibility of the carbodiimide compound, it has been studied to use polyethylene terephthalate as a thermoplastic resin constituting the masterbatch. However, since polyethylene terephthalate has a melting point of about 250 ° C., it needs to be melt-processed at a temperature of 260 ° C. or higher when preparing a masterbatch using it, and may be hydrolyzed during this melt-processing. It was. As a result, a part of the carbodiimide compound may be consumed by reacting with the end of the polyethylene terephthalate after hydrolysis. Therefore, even if a master batch containing polyethylene terephthalate as a thermoplastic resin is added and molded, the content of the reactive carbodiimide compound is reduced and the reactivity is lowered. Hydrolyzability may not be improved sufficiently.

  An object of the present invention is to provide a polyester resin composition in which the reactivity of a carbodiimide compound is not lowered while the dispersibility and affinity to a molded body are increased.

The inventor of the present invention has reached 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 as follows.
(1) A polyester resin composition containing a copolymerized polyester resin (A) and a carbodiimide compound (B), wherein the mass ratio (A / B) of the copolymerized polyester resin (A) and the carbodiimide compound (B) is 10 / 90-85 / 15 polyester resin composition characterized by the above-mentioned.
(2) The polyester according to (1), wherein the copolyester resin (A) is a crystalline polyester resin having a melting point of 210 ° C. or lower and / or an amorphous polyester resin having a glass transition temperature of 50 ° C. or higher. Resin composition.
(3) The polyester resin composition according to (1) or (2), wherein the copolymer polyester resin (A) contains 0.05 to 10 mol% of an organic sulfonate compound as a copolymer component.
(4) A resin pellet comprising the polyester resin composition according to any one of (1) to (3) above.
(5) A method for producing resin pellets as described in (4) above, wherein the copolymer polyester resin (A) and the carbodiimide compound (B) are melt-kneaded at a temperature of 220 ° C. or lower. Pellet manufacturing method.
(6) A molded article obtained by melt-molding a thermoplastic resin containing the resin pellet described in (4) above.

  According to the present invention, a polyester resin composition containing a carbodiimide compound in a copolyester resin can be obtained without reducing the reactivity. The resin pellet obtained from the polyester resin composition of the present invention has improved dispersibility and affinity of the carbodiimide compound in the copolymerized polyester resin, and is added to a thermoplastic resin such as a polyester resin as a master batch of the carbodiimide compound. Can be used, and a molded article having sufficiently improved hydrolysis resistance can be formed.

Hereinafter, the present invention will be described in detail.
The polyester resin composition of the present invention contains a copolymerized polyester resin (A) and a carbodiimide compound (B), and the resin pellet containing the resin composition is made of a thermoplastic resin (hereinafter referred to as a polyester resin). When molding a matrix resin), it can be added as a master batch of a carbodiimide compound to improve the hydrolysis resistance of the molded body.

<Copolymerized polyester resin (A)>
The copolymerized polyester resin (A) constituting the polyester resin composition of the present invention is mainly composed of a dicarboxylic acid component and a glycol component, and includes those modified products.

  The dicarboxylic acid component constituting the copolymerized polyester resin (A) is not particularly limited, and examples thereof include terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, and 3-tert-butyl. Aromatic dicarboxylic acids such as isophthalic acid and diphenic acid; saturated aliphatic dicarboxylic acids such as oxalic acid, succinic acid, succinic anhydride, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, aicosanedioic acid, and hydrogenated dimer acid Unsaturated fatty dicarboxylic acids such as fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, dimer acid; 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid Acid, 1,2-cyclohexanedicarboxylic acid, 2,5-norbornenedicarboxylic acid Beauty anhydrides, alicyclic dicarboxylic acids such as tetrahydrophthalic acid and its anhydride.

  Among the dicarboxylic acids described above, terephthalic acid is preferably used as the dicarboxylic acid component, and the content of terephthalic acid in the dicarboxylic acid component is preferably 30 to 99.9 mol%, and 45 to 99.9 mol. % Is more preferable, and 60 to 99.9 mol% is still more preferable.

  The glycol component constituting the copolyester resin (A) is not particularly limited, and examples thereof include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, and 2-methyl. -1,3-propanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 2-ethyl-2- Aliphatic glycols such as butylpropanediol; Alicyclic glycols such as 1,4-cyclohexanedimethanol and 1,3-cyclobutanedimethanol; Diethylene glycol, triethylene glycol, dipropylene glycol, polytetramethylene glycol, polyethylene glycol, polypropylene A such as glycol Glycol containing glycol; alkylene oxide adducts of bisphenols (bisphenol A) such as 2,2-bis [4- (hydroxyethoxy) phenyl] propane and bisphenols such as bis [4- (hydroxyethoxy) phenyl] sulfone An alkylene oxide adduct of bisphenol S (bisphenol S) can also be used.

  In the present invention, the copolyester resin (A) must have the dicarboxylic acid component composed of two or more dicarboxylic acids or the glycol component composed of two or more glycols. Each of the glycol components may be composed of two or more.

In the present invention, the copolymer polyester resin (A) preferably contains an organic sulfonate compound as a copolymer component. By using a polyester resin composition containing a copolymerized polyester resin containing an organic sulfonate compound as a copolymerization component, an increase in the viscosity of the molded product can be suppressed.
Examples of the organic sulfonate compound include dicarboxylic acid having a sulfonate and glycol having a sulfonate.
The copolymerization amount of the organic sulfonate compound is preferably 0.05 to 10 mol%, more preferably 0.15 to 7.5 mol% of the copolymerized polyester resin (A), and More preferably, it is 25-5 mol%. When the content of the organic sulfonate compound is less than 0.05 mol%, the effect of suppressing the increase in the viscosity of the molded article is not sufficient, whereas when the content of the organic sulfonate compound exceeds 10 mol%, the obtained molding is obtained. The body's hydrolysis resistance may decrease.

Examples of the raw material used for copolymerizing the organic sulfonate compound with the copolymer polyester resin (A) include 5-sodium sulfoisophthalic acid, 5-sodium sulfoterephthalic acid, 5-potassium sulfoisophthalic acid, and 5-potassium. Examples include sulfoterephthalic acid, 5-lithium sulfoisophthalic acid, and 5-lithium sulfoterephthalic acid. Further, sodium 3,5-di (carbo-β-hydroxyethoxy) benzenesulfonate obtained by adding ethylene glycol or the like to the above dicarboxylic acid, sodium 2,5-di (carbo-β-hydroxyethoxy) benzenesulfonate, 3 , 5-di (carbo-β-hydroxyethoxy) benzenesulfonic acid potassium, 3,5-di (carbo-β-hydroxyethoxy) benzenesulfonic acid lithium and the like, and methanol etc. are added to the dicarboxylic acid. And esters of dicarboxylic acids such as dimethyl 5-sodium sulfoisophthalate, dimethyl 5-sodium sulfoterephthalate, dimethyl 5-potassium sulfoisophthalate, and dimethyl 5-lithium sulfoisophthalate.
In addition to the above, metal salt compounds of glycols such as 2-sulfo-1,4-butanediol and 2,5-dimethyl-3-sulfo-2,5-hexanediol can be mentioned.
Among them, 5-sodium sulfoisophthalic acid, 5-sodium sulfoisophthalic acid dimethyl, 5-sodium sulfoisophthalic acid diglycol ester, etc. should be used as a raw material in terms of a good balance between viscosity increase inhibiting effect and hydrolysis resistance. It is particularly preferable to use 5-sodium sulfoisophthalic acid as a raw material from the viewpoint of effectively imparting viscosity increase inhibition.

The copolymerized polyester resin (A) may be copolymerized with a hydroxycarboxylic acid as necessary. Hydroxycarboxylic acids include lactic acid, glycolic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxyisobutyric acid, 2-hydroxy-2-methylbutyric acid, 2-hydroxyvaleric acid, 3-hydroxy Hydroxycarboxylic acids such as valeric acid, 4-hydroxyvaleric acid, 5-hydroxyvaleric acid, 6-hydroxycaproic acid, 10-hydroxystearic acid, 4- (β-hydroxy) ethoxybenzoic acid, β-propiolactone, β And aliphatic lactones such as -butyrolactone, γ-butyrolactone, δ-valerolactone, and ε-caprolactone.
When copolymerizing hydroxycarboxylic acid, the copolymerization amount is preferably 20 mol% or less of the total dicarboxylic acid component.

Further, the copolymerized polyester resin (A) may be copolymerized with a trifunctional or higher functional carboxylic acid, a trifunctional or higher functional alcohol, a monocarboxylic acid, or a monoalcohol as long as the amount is small.
Trifunctional or higher carboxylic acids include trimellitic acid, trimellitic anhydride, trimesic acid, pyromellitic acid, pyromellitic anhydride, benzophenone tetracarboxylic acid, benzophenone tetracarboxylic anhydride, ethylene glycol bis (anhydro trimellitate) ), Glycerol tris (anhydro trimellitate), 1,2,3,4-butanetetracarboxylic acid and the like. Examples of the tri- or higher functional alcohol include trimethylolethane, trimethylolpropane, glycerin, pentaerythritol, α-methylglucose, mannitol, and sorbitol.
When copolymerizing a trifunctional or higher functional carboxylic acid or a trifunctional or higher functional alcohol, the copolymerization amount is preferably 5 mol% or less, and preferably 4 mol% or less, based on the total dicarboxylic acid component or total glycol component, respectively. It is more preferable that it is 3 mol% or less. When the copolymerization amount of a trifunctional or higher functional carboxylic acid or a trifunctional or higher functional alcohol exceeds 5 mol%, processability such as stretchability may be impaired when processing into a molded body using the obtained master batch. .

  Examples of the monocarboxylic acid copolymerized with the copolymerized polyester resin (A) include benzoic acid, phenylacetic acid, lauric acid, palmitic acid, stearic acid, oleic acid and the like, and monoalcohols include cetyl alcohol, decyl alcohol, Examples include lauryl alcohol, myristyl alcohol, octyl alcohol, stearyl alcohol, and the like. When copolymerizing monocarboxylic acid and monoalcohol, the copolymerization amount is preferably 0.2 to 20 mol% with respect to the total dicarboxylic acid component and the total glycol component, respectively.

  The copolyester resin (A) is preferably a crystalline polyester resin having a melting point of 210 ° C. or lower, an amorphous polyester resin having a glass transition temperature of 50 ° C. or higher, or a mixture thereof. The amorphous property of the copolyester resin (A) is such that the heat of crystal fusion corresponding to the melting point, measured using a differential scanning calorimeter at a heating rate of 10 ° C./min, is less than 0.25 cal / g. It is defined as a thing.

  The crystalline polyester resin preferably has a melting point of 210 ° C. or lower, more preferably 30 to 200 ° C., further preferably 40 to 195 ° C., and most preferably 50 to 190 ° C. When the melting point exceeds 210 ° C., the kneading temperature at the time of melt mixing with the carbodiimide compound becomes too high, the copolymerized polyester resin (A) is hydrolyzed, and the concern that a part of the carbodiimide compound reacts increases. Further, when the melting point is less than 30 ° C., there is a concern such as blocking when handling the obtained master batch, and workability may be lowered. Note that the crystalline polyester resin having a melting point exceeding 210 ° C. does not hinder the use of the crystalline polyester resin because the expected effect can be expressed by devising the processing conditions. For example, a crystalline polyester resin having a melting point exceeding 210 ° C. can be kneaded using shearing heat generation even if the kneading temperature is less than 210 ° C., and the kneading temperature exceeds 220 ° C. Even if there is, the carbodiimide compound (B) is introduced from the upstream side of the extruder, the crystalline polyester resin having a melting point exceeding 210 ° C. is supplied on the downstream side of the extruder, and melt mixing is performed in a short time. It is possible to prepare a resin composition.

  The amorphous polyester resin preferably has a glass transition temperature of 50 ° C or higher, more preferably 55 ° C or higher, further preferably 60 ° C or higher, and most preferably 65 ° C or higher. When the glass transition temperature is less than 50 ° C., there is a concern such as blocking when handling the obtained master batch, and workability may be lowered. The glass transition temperature of the polyester resin can be controlled within the above range by appropriately selecting a monomer to be copolymerized.

  In the present invention, the use of a crystalline polyester resin rather than an amorphous polyester resin as the copolyester resin (A) reduces problems such as blocking when handling a masterbatch, and improves workability. Is particularly preferable.

The number average molecular weight of the copolyester resin (A) is preferably 1000 to 20000, more preferably 1500 to 15000, still more preferably 2000 to 10,000, and most preferably 2500 to 5000. . When the number average molecular weight of the copolymerized polyester resin (A) is less than 1000, the resulting polyester resin composition has insufficient compatibility when used as a masterbatch and may impair the transparency of the molded product. . On the other hand, when the number average molecular weight of the copolyester resin (A) exceeds 20000, the melt viscosity at the time of mixing and melt-kneading with the carbodiimide compound is increased, and not only the workability is lowered, but also the heat generation is more than necessary due to shearing heat generation. By increasing the kneading temperature, the copolymerized polyester resin (A) is hydrolyzed, and as described above, there is an increased concern that a part of the carbodiimide compound reacts. Moreover, since ester group density | concentration in a polyester resin composition will increase when a number average molecular weight is high, there exists a tendency for hydrolysis resistance to fall.
As a method for controlling the number average molecular weight of the copolymerized polyester resin (A), a method of terminating the polymerization of the polyester melt during polymerization at a predetermined viscosity, a depolymerizer is added after producing a polyester resin having a high molecular weight. And a method of controlling the molecular weight and a method of adding a monoalcohol or a monocarboxylic acid. Among them, a method of terminating the polymerization with a predetermined viscosity is preferable.

  The acid value of the copolyester resin (A) is preferably 10 mgKOH / g or less, and more preferably 8 mgKOH / g or less. When the acid value exceeds 10 mgKOH / g, the copolymerized polyester resin (A) may be inferior in hydrolysis resistance.

In the present invention, examples of the method for producing the copolyester resin (A) include known production methods such as a direct esterification method and a transesterification method. Examples of the direct esterification method include a method in which a necessary monomer raw material is injected into a reaction vessel, an esterification reaction is performed, and then a polycondensation reaction is performed. In the esterification reaction, the reaction is performed by heating and melting at a temperature of 180 ° C. or higher for 4 hours or longer in a nitrogen atmosphere. In the polycondensation reaction, the polycondensation reaction proceeds under a reduced pressure of 130 Pa or less until a desired molecular weight is reached at a temperature of 220 to 280 ° C. A catalyst may be used in the esterification reaction and polycondensation reaction. Examples of the catalyst include titanium compounds such as tetrabutyl titanate, metal acetates such as zinc acetate, magnesium acetate, and aluminum compounds, and organic tin compounds such as antimony trioxide, hydroxybutyltin oxide, and tin octylate. The amount of the catalyst, the acid component per mol, preferably in a 0.1 × ^{10 -4} ~100 × ¹⁰ -4 mol.

  The copolyester resin (A) constituting the polyester resin composition of the present invention may contain a modified polyester resin. Examples of the modified polyester resin include a polyester polyurethane resin, a polyether ester, and an acrylic modified polyester resin. From the viewpoint of improving the hydrolysis resistance of the resulting molded article, a polyester polyurethane resin modified with an organic diisocyanate component is preferred. When polyester polyurethane resin is used, the crosslink density due to the carbodiimide compound increases, so that the resulting molded article has improved hydrolysis resistance as described above, but a film is produced using polyethylene terephthalate as the thermoplastic resin. When the film is formed, the compatibility with polyethylene terephthalate is lowered and the stretchability may be inferior.

The polyester polyurethane resin used in the present invention is obtained by adding an organic diisocyanate component to a polyester resin composed of the above components.
A known isocyanate can be used as the organic diisocyanate component. Specifically, 1,6-hexamethylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, p-phenylene diisocyanate, diphenylmethane diisocyanate, m-phenylene diisocyanate, tetramethylene diisocyanate, 3,3 ′ -Dimethoxy-4,4'-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 2,6-naphthalene diisocyanate, 3,3'-dimethyl-4,4'-diisocyanate, 4,4'-diisocyanate diphenyl ether, 1,5 -Xylylene diisocyanate, 1,3-diisocyanate methylcyclohexane, 1,4-diisocyanate methylcyclohexane, 4,4'-diisocyanate cyclohexane, 4,4'-diisocyanate Sulfonates cyclohexyl methane include isocyanates such as isophorone diisocyanate. Of these, 1,6-hexamethylene diisocyanate is preferably used from the viewpoints of reactivity, weather resistance, and the like.
These organic diisocyanates may be used as a mixture of two or more.

  The polyester resin component content in the polyester polyurethane resin is preferably 40% by mass or more, more preferably 60% by mass or more, and further preferably 80% by mass or more. When there is little content of the polyester resin component in a polyester polyurethane resin, the hydrolysis resistance improvement effect may not be enough in the molded object obtained.

  The polyester polyurethane resin can be produced by a known method. For example, a solution polymerization method of a copolymerized polyester resin and an organic diisocyanate in a solvent can be used. In solution polymerization, a copolyester resin obtained in advance is dissolved in a general-purpose solvent such as toluene, and then an organic diisocyanate component and a urethanization catalyst are charged and reacted at 40 to 80 ° C. to obtain a polyester polyurethane resin. . Further, in order to increase the reactivity of urethanization, dimethylolpropionic acid, dimethylolbutanoic acid, bis- (2-hydroxyethyl) propionic acid, bis- (2-hydroxyethyl) butane is used with respect to the copolyester resin. It is preferable to copolymerize an acid or the like. Examples of the urethanization catalyst include organotin compounds such as dibutyltin dilaurate and tin octylate, and amine-based compounds such as triethylenediamine.

<Carbodiimide compound (B)>
The carbodiimide compound (B) constituting the polyester resin composition of the present invention is a compound having a carbodiimide group (—N═C═N—) in the molecule, and depending on the number of carbodiimide groups in the molecule, monocarbodiimide, Classified as polycarbodiimide.

  Examples of the monocarbodiimide having one carbodiimide group in the molecule include N, N′-di-2,6-diisopropylphenylcarbodiimide, N, N′-diphenylcarbodiimide, and N, N′-di-2,6. -Dimethylphenylcarbodiimide, N, N'-di-2,6-di-tert-butylphenylcarbodiimide, N-tolyl-N'-phenylcarbodiimide, N, N'-di-p-nitrophenylcarbodiimide, N, N '-Di-p-aminophenylcarbodiimide, N, N'-di-p-hydroxyphenylcarbodiimide, N-octadecyl-N'-phenylcarbodiimide, N-benzyl-N'-phenylcarbodiimide, N, N'-di- o-Ethylphenylcarbodiimide, N, N'-di-p-ethylphenylcarbodiimide N, N'-di-o-isopropylphenylcarbodiimide, N, N'-di-p-isopropylphenylcarbodiimide, N, N'-di-o-isobutylphenylcarbodiimide, N, N'-di-p-isobutylphenyl Carbodiimide, N, N'-di-2,6-diethylphenylcarbodiimide, N, N'-di-2-ethyl-6-isopropylphenylcarbodiimide, N, N'-di-2-isobutyl-6-isopropylphenylcarbodiimide N, N'-di-2,4,6-trimethylphenylcarbodiimide, N, N'-di-2,4,6-triisopropylphenylcarbodiimide, N, N'-di-2,4,6-tri Isobutylphenylcarbodiimide, di-β-naphthylcarbodiimide, N, N′-di-o-tolylcarbodiimide, N -Tolyl-N'-cyclohexylcarbodiimide, N, N'-di-p-tolylcarbodiimide, N, N'-benzylcarbodiimide, N-octadecyl-N'-tolylcarbodiimide, N-cyclohexyl-N'-tolylcarbodiimide, N -Aromatic monocarbodiimide such as benzyl-N'-tolylcarbodiimide, N, N'-dioctyldecylcarbodiimide, N, N'-di-cyclohexylcarbodiimide, diisopropylcarbodiimide, dimethylcarbodiimide, diisobutylcarbodiimide, dioctylcarbodiimide, t-butylisopropyl Aliphatic / or alicyclic monocarbodiimides such as carbodiimide and di-t-butylcarbodiimide are exemplified.

Examples of the polycarbodiimide having two or more carbodiimide groups in the same molecule include poly (p-phenylenecarbodiimide), poly (m-phenylenecarbodiimide), poly (4,4′-diphenylmethanecarbodiimide), and poly (methyl- Diisopropylphenylenecarbodiimide), poly (triisopropylphenylenecarbodiimide), poly (triylcarbodiimide), poly (diisopropylphenylenecarbodiimide), p-phenylene-bis-di-o-tolylcarbodiimide, p-phenylene-bis-dicyclohexylcarbodiimide, ethylene -Bis-diphenylcarbodiimide, hexamethylene-bis-dicyclohexylcarbodiimide and the like.
Polycarbodiimide can be produced by polymerizing the above-mentioned monocarbodiimide, and a commercially available product can also be used. Examples of commercially available products of polycarbodiimide include aromatic polycarbodiimides such as Stavacsol P manufactured by Rheinhemy, Stavacsol P-100 manufactured by Rheinhemy, Stavacsol P-400 manufactured by Rheinhemy, and LA- manufactured by Nisshinbo Chemical Co., Ltd. 1. An aliphatic / or alicyclic polycarbodiimide such as HMV-15CA manufactured by Nisshinbo Chemical Co., Ltd. can be mentioned.

  As a method for producing polycarbodiimide, in addition to the above method, a method for producing using organic diisocyanate may be mentioned. As the organic diisocyanate, various organic diisocyanates such as aromatic diisocyanate, aliphatic diisocyanate, and alicyclic diisocyanate, and mixtures thereof can be used.

  Examples of the organic diisocyanate include 1,5-naphthalene diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-diphenyldimethylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4- Tolylene diisocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4-diisocyanate, methylcyclohexane diisocyanate, tetramethylxylylene diisocyanate, 2,6-diisopropylphenyl isocyanate, 1,3,5-triisopropylbenzene-2,4-diiso Aneto, methylenebis (4,1-cyclohexylene) = can be mentioned diisocyanate. These may be used individually by 1 type and may be used in combination of 2 or more type. Among these organic diisocyanates, dicyclohexylmethane-4,4-diisocyanate and methylenebis (4,1-cyclohexylene) = diisocyanate are preferable.

  In order to seal the terminal of the carbodiimide compound and control the degree of polymerization, a terminal blocking agent such as monoisocyanate can be used. Examples of the monoisocyanate include phenyl isocyanate, tolyl isocyanate, dimethylphenyl isocyanate, cyclohexyl isocyanate, butyl isocyanate, and naphthyl isocyanate. These may be used individually by 1 type and may be used in combination of 2 or more type.

  In addition to the monoisocyanate, an active hydrogen compound capable of reacting with isocyanate may be used as a terminal blocker for the carbodiimide compound. Active hydrogen compounds include aliphatic, aromatic and alicyclic compounds such as methanol, ethanol, phenol, cyclohexanol, N-methylethanolamine, polyethylene glycol monomethyl ether, polypropylene glycol monomethyl ether and other alcohols, diethylamine Secondary amines such as dicyclohexylamine, primary amines such as butylamine and cyclohexylamine, carboxylic acids such as succinic acid, benzoic acid and dichlorohexanecarboxylic acid, thiols such as ethyl mercaptan, allyl mercaptan, thiophenol, and epoxy groups And the like. These may be used individually by 1 type and may be used in combination of 2 or more type.

In the present invention, the carbodiimide compound (B) preferably contains an isocyanate group at the end in order to increase the reactivity with the polyester resin. For this reason, it is preferable to leave an isocyanate group appropriately at the terminal even when the terminal isocyanate of the polycarbodiimide is sealed using the terminal blocking agent as described above. Specifically, the content of the terminal isocyanate in the carbodiimide compound is preferably more than 0% by mass and less than 15% by mass, more preferably 0.1 to 12% by mass, and more preferably 0.5 to 10% by mass. % Is more preferable.
In the carbodiimide compound in which the content of the terminal isocyanate group is 0% by mass, the reaction between the terminal hydroxyl group of the copolymerized polyester resin (A) and the isocyanate group does not occur. Therefore, when this carbodiimide compound is used for the master batch, the compatibility with the matrix resin and the dispersibility are lowered, so that the obtained molded product is uneven and the strength may be lowered.
On the other hand, in a carbodiimide compound having a terminal isocyanate group of 15% by mass or more, the terminal hydroxyl group and the isocyanate group of the copolyester resin (A) are excessively reacted to increase the crosslinking density. When a carbodiimide compound is used, the dispersibility into the matrix resin may decrease, and the stretchability may decrease during film formation.

  In the present invention, the molecular weight of the polycarbodiimide compound is preferably 1000 to 10,000, preferably 1000 to 9000, and more preferably 1000 to 8000. A polycarbodiimide compound having a molecular weight of 1000 or less has a low carbodiimide group concentration, so it must be added in a large amount to the polyester resin composition, and the compatibility with the matrix resin is reduced, and the resulting molded product is reduced in strength. Sometimes. On the other hand, when the molecular weight of the polycarbodiimide compound exceeds 10,000, the compatibility with the matrix resin and the dispersibility are lowered, so that the obtained molded product becomes non-uniform and the strength may be lowered.

In the polycarbodiimide compound, the number of carbodiimide groups in the molecule is preferably 2 to 100, more preferably 2 to 80, and even more preferably 2 to 60. With monocarbodiimide having less than 2 carbodiimide groups, the effect of trapping carboxyl groups generated when a matrix resin having an ester bond such as a polyester resin is hydrolyzed is reduced, and the resulting molded product is resistant to hydrolysis. May decrease. On the other hand, when the number of carbodiimide groups in the polycarbodiimide compound exceeds 100, the crosslinking density may increase too much, and the resulting polyester resin composition may become non-uniform or gel, and this polyester resin composition may be When a PET film or the like is formed as a master batch, the stretchability is lowered and the film may be broken.
The number of carbodiimide groups, which is the number of carbodiimides in the polycarbodiimide molecule, corresponds to (polymerization degree -1) if it is a polycarbodiimide obtained from a diisocyanate compound. For example, the degree of polymerization of polycarbodiimide obtained by connecting 21 diisocyanate compounds in a chain is 21, and the number of carbodiimide groups in the molecular chain is 20. Usually, polycarbodiimide is a mixture of molecules having various degrees of polymerization, and the number of carbodiimide groups is represented by an average value. The number of carbodiimide groups can be measured by ¹³ C-NMR, IR, GPC, titration method or a combination thereof, and can be grasped as the number of carbodiimide groups. It is possible to observe a peak at 130 to 142 ppm in ¹³ C-NMR and 2130 to 2140 cm ⁻¹ in IR.

<Polyester resin composition>
In the polyester resin composition of the present invention, the mass ratio (A / B) of the copolymerized polyester resin (A) and the carbodiimide compound (B) needs to be 10/90 to 85/15, and 20/80 It is preferably ˜80 / 20, more preferably 30/70 to 75/25. When the content of the copolymerized polyester resin (A) is less than 10% by mass, the molded product formed by including a master batch containing the obtained polyester resin composition has insufficient compatibility and transparency. It will be damaged. On the other hand, when the content of the copolymerized polyester resin (A) exceeds 85% by mass, sufficient hydrolysis resistance cannot be imparted to the molded body.

  The polyester resin composition of the present invention may contain an additive as long as the effects of the invention are not impaired. Additives include cross-linking agents, antioxidants, viscosity modifiers, extenders, dyes, pigments, UV absorbers, void forming agents, lubricants, radical scavengers, thermal stabilizers, flame retardants, inhibitors, and antiblocking agents. Agents, surfactants, slip aids, gloss improvers, degradation accelerators, viscosity modifiers, dispersion stabilizers, and the like.

  The polyester resin composition of the present invention can be produced by mixing a copolymer polyester resin (A) and a carbodiimide compound (B). The method is not particularly limited. For example, a method of melt kneading using a twin screw kneading extruder or the like is the simplest and most efficient.

<Resin pellets>
The resin pellets of the present invention can be produced by melt-kneading using the above-described biaxial kneader-extruder or the like, then taking them into a strand shape from a die die, cooling, and pelletizing.
The kneading temperature for melt kneading is preferably 220 ° C. or lower. Even if the kneading temperature is set to 220 ° C. or lower, the resin temperature may exceed 220 ° C. due to shear heat generation during melt kneading, so while monitoring the resin temperature so that the resin temperature does not exceed 220 ° C., It is preferable to perform melt-kneading by controlling the screw rotation speed and the discharge amount. Further, by using a copolymer polyester resin (A) having a low melting point or glass transition temperature, it is possible to reduce shearing heat generation during melt-kneading.
The obtained resin pellet can be used as a master batch. The master batch may be subjected to heat treatment such as drying as necessary.

<Thermoplastic resin>
The said resin pellet can be made into a molded object by melt-molding, after mixing with various thermoplastic resins (matrix resin), such as a polyester resin. In addition, since the resin pellet of the present invention uses the copolyester resin (A), it can be particularly suitably used for a polyester matrix resin such as polyethylene terephthalate, but is particularly limited to a polyester matrix resin. However, it can be used in a wide range as long as no problem occurs such as compatibility.
The acid value of the matrix resin is preferably 10 mgKOH / g or less, more preferably 8 mgKOH / g or less, and further preferably 6 mgKOH / g or less. When the acid value of the matrix resin exceeds 10 mgKOH / g, the carbodiimide group in the master batch to be mixed reacts to reduce the effective carbodiimide group concentration contributing to hydrolysis resistance, and the expected hydrolysis resistance. It may not be obtained.

<Molded body>
The molded article of the present invention is a thermoplastic resin used as a matrix resin and melt-molded by containing resin pellets, and has excellent hydrolysis resistance due to the carbodiimide compound contained in the resin pellets.
Such an effect is effectively exhibited especially when the matrix resin is a polyester resin. In order to further improve the hydrolysis resistance, the amount of resin pellets added is the ester group concentration (a equivalent / ton) of the polyester resin of the matrix resin and the ester group concentration of the copolyester resin (A) constituting the master batch. The ratio (c / (a + b)) to the carbodiimide group concentration (c equivalent / ton) of the carbodiimide compound (B) with respect to the total of (b equivalent / ton) is preferably 0.1 to 1.5, It is more preferably 0.2 to 1.3, still more preferably 0.3 to 1.1, and most preferably 0.5 to 1.0. If the ratio (c / (a + b)) is less than 0.1, the expected hydrolysis resistance cannot be obtained, and if it exceeds 1.5, the carbodiimide group in the molded body undergoes excessive reaction, resulting in a decrease in thermal stability. May cause gelation or gelation, and when the film is formed, the stretchability may be reduced or the film may be broken.

  Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited to these examples.

  The measuring method used for evaluation of the copolyester resin (A) used in Examples and Comparative Examples is as follows.

1. Evaluation Method (1) Number Average Molecular Weight of Copolyester Resin (A) Liquid-feeding unit ("LC-10ADvp type" manufactured by Shimadzu Corporation) and UV-visible spectrophotometer ("SPD-6AV type" manufactured by Shimadzu Corporation)) Was obtained by GPC analysis. The analysis conditions were a detection wavelength of 254 nm, tetrahydrofuran was used as a solvent, and the measurement was performed in terms of polystyrene.

(2) Composition of copolymerized polyester resin (A) Using an NMR measuring apparatus (“JNM-LA400 type” manufactured by JEOL Ltd.), ¹ H-NMR measurement was performed to determine the composition of each copolymer component. Note that deuterated trifluoroacetic acid was used as a measurement solvent.

(3) Glass transition temperature (Tg) and melting point (Tm) of the copolyester resin (A)
In accordance with JIS-K 7121, a glass transition temperature (Tg) was calculated from a chart heated at 10 ° C./min from 20 ° C. to 300 ° C. using an input-compensated differential scanning calorimeter (“Diamond DSC” manufactured by PerkinElmer). ), And the melting point (Tm) was read.

(4) Compatibility of resin pellet and polyester resin (matrix resin) The appearance of the films obtained in Examples and Comparative Examples was visually observed. Judgment was made based on the following evaluation criteria.
◯: Excellent transparency.
(Triangle | delta): Although it is transparent, the dispersion | distribution of the mixed masterbatch is non-uniform | heterogenous and has a feeling of fluctuation.
X: Opaque or cloudy.

(5) Extensibility In Examples and Comparative Examples, extensibility was evaluated by operability when producing films.
○: There is no problem in operation.
(Triangle | delta): Although it can extend | stretch, a film thickness etc. are nonuniform.
X: It cannot extend | stretch with a fracture | rupture etc.

(6) Hydrolysis resistance The obtained film was treated for 2000 hours under the condition of 85 ° C. × 85% RH. About the film before and behind a process, the tensile breaking strength was measured, the tensile strength retention was computed from the following formula, and the hydrolysis resistance was judged by the following reference | standard. The evaluation result is preferably ◎ or ○, particularly preferably ◎.
The film was cut into a strip shape having a width of 10 mm and a length of 150 mm, and used as a measurement sample. The tensile breaking strength was measured under the conditions of 23 ° C. × 50% RH and a tensile speed of 10 mm / min.
Tensile strength retention (%) = (Tensile rupture strength of the film after treatment) / (Tensile rupture strength of the film before treatment) × 100
A: Tensile strength retention is 95% or more.
A: Tensile strength retention is 90% or more and less than 95%.
Δ: Tensile strength retention is 70% or more and less than 90%.
X: Tensile strength retention is less than 70%.

(7) Viscosity change The obtained film was dissolved using an equal mass mixture of phenol and ethane tetrachloride as a solvent, and the intrinsic viscosity η was measured under the conditions of a sample concentration of 0.5 mass% and a temperature of 20 ° C.
Since the intrinsic viscosity of the polyester resin used as the matrix resin at the time of film production was 0.60, the viscosity change rate was calculated from the following formula in comparison with this, and the viscosity change rate was evaluated according to the following criteria. The evaluation result is preferably ◎ or ○, particularly preferably ◎.
Viscosity change rate (%) = η / 0.60 × 100
◎: Less than 120% ○: 120% or more, less than 130% Δ: 130% or more, less than 140% ×: 140% or more

2. Raw material (1) Carbodiimide compound (B)
B1: Aromatic polycarbodiimide (Rhein Chemie's “Stabbackzol P”, poly (1,3,5-triisopropylbenzene) carbodiimide, number average molecular weight of about 700)
B2: Alicyclic polycarbodiimide ("LA-1" manufactured by Nisshinbo Chemical Co., Ltd., average polymerization degree 15, with terminal isocyanate group)
B3: Aromatic monopolycarbodiimide (Rhein Chemie's “Stabbackzol I”, N, N′-di-2,6-diisopropylphenylcarbodiimide)
B4: Alicyclic type polycarbodiimide (Nisshinbo "HMV-15CA", average polymerization degree 15, no terminal isocyanate group)

(2) Compounds other than carbodiimide compounds (epoxy compounds)
X: EGMA (ethylene-glycidyl methacrylate copolymer) -g (graft) -AS (acrylonitrile styrene) copolymer (“MODIPA A4400” manufactured by NOF Corporation, EGMA / AS = 70/30 (mass ratio), E / GMA = 85/15 (mass ratio))

(3) Preparation Preparation Example 1 of Copolymerized Polyester Resin (A)
70 mol% terephthalic acid, 30 mol% sebacic acid, 135 mol% ethylene glycol and 0.1 g of tetrabutyl titanate as a polymerization catalyst were charged into the reactor, and the system was replaced with nitrogen. And while stirring these raw materials at 1000 rpm, the reactor was heated at 245 ° C. and melted. After the temperature in the reactor reached 245 ° C., the esterification reaction was allowed to proceed for 3 hours. After 0.5 hours, the temperature in the system was set to 240 ° C., and the pressure in the system was reduced. After the inside of the system reached a high vacuum (pressure: 0.1 to 10 ⁻⁵ Pa), a polymerization reaction was further performed for 0.5 hour to obtain a copolymerized polyester resin (A1).

Preparation Examples 2-12
Copolymerized polyester resins (A2) to (A12) were obtained in the same manner as in Preparation Example 1, except that the type of monomer used, its composition, and the polymerization reaction time were changed as shown in Table 1.

Preparation Example 13 (Preparation of polyester polyurethane resin)
A polyester polyurethane resin (A13) was obtained by adding an organic diisocyanate component to the copolymerized polyester resin (A1) obtained in Preparation Example 1.
Specifically, the same amount of toluene was charged into the copolymerized polyester resin (A1), and the resin was dissolved at 100 ° C. Thereafter, the temperature was raised to 130 ° C., 30% by mass of the total amount of the copolyester resin (A1) and toluene was distilled, and the reaction system was dehydrated. Thereafter, the system was cooled to 60 ° C., 40% by mass of methyl ethyl ketone and 9% by mass of dimethylolbutanoic acid were added to the copolymerized polyester resin (A1), and the mixture was stirred at 60 ° C. for 30 minutes. Thereafter, 6% by mass of 1,6-hexamethylene diisocyanate was charged, and the mixture was stirred at 60 ° C. for 30 minutes. Subsequently, dibutyltin dilaurate was added as a catalyst, and the mixture was heated to 80 ° C. and reacted. The concentration was adjusted to 30% to obtain a polyester polyurethane resin (A13).

  Tables 1 and 2 show the monomer charge composition, polymerization reaction time, and characteristics of the copolyester resins obtained in Preparation Examples 1 to 13.

Preparation Example 14
A reactor was charged with 98 mol% terephthalic acid, 2 mol% 5-sodium sulfoisophthalic acid, 75 mol% ethylene glycol, 60 mol% butanediol and 0.1 g tetrabutyl titanate and 0.1 g lithium acetate as a polymerization catalyst. The inside was replaced with nitrogen. And while stirring these raw materials at 1000 rpm, the reactor was heated at 245 ° C. and melted. After the temperature in the reactor reached 245 ° C., the esterification reaction was allowed to proceed for 3 hours. After 0.5 hours, the temperature in the system was set to 240 ° C., and the pressure in the system was reduced. After the inside of the system reached a high vacuum (pressure: 0.1 to 10 ⁻⁵ Pa), a polymerization reaction was further performed for 0.5 hour to obtain a copolymerized polyester resin (A14).

Preparation Examples 15-31
Copolymerized polyester resins (A15) to (A31) were obtained in the same manner as in Preparation Example 14 except that the type and composition of the monomer used and the polymerization reaction time were changed as shown in Table 3.

Preparation Example 32 (Preparation of polyester polyurethane resin)
In Preparation Example 13, a polyester polyurethane resin (A32) was obtained in the same manner as Preparation Example 13 except that the polyester resin (A14) was used instead of the polyester resin (A1).

  Tables 3 and 4 show the monomer charge composition, polymerization reaction time, and characteristics of the copolymer polyester resins obtained in Preparation Examples 14 to 32.

In addition, the abbreviation in Tables 1-4 shows the following, respectively.
TPA: terephthalic acid IPA: isophthalic acid SIPA: 5-sodium sulfoisophthalic acid SIPM: 5-sodium sulfoisophthalic acid dimethyl SIPAL: 5-lithium sulfoisophthalic acid ADA: adipic acid SEA: sebacic acid EG: ethylene glycol SIPG: 5-sodium Sulfoisophthalic acid diglycol ester PG: propanediol BD: 1,4-butanediol NPG: neopentyl glycol TCD: tricyclodecane dimethanol ISB: isosorbide HDI: 1,6-hexamethylene diisocyanate

Example 1
After uniformly mixing 35 parts by mass of the copolymerized polyester resin (A1) and 65 parts by mass of the carbodiimide compound (B1), a total charge of 3 kg is supplied with a loss-in-weight continuous quantitative supply device (CE-W-1 type manufactured by Kubota Corporation). It was used for melt kneading by supplying it to the main supply port of a twin screw extruder (TEM26SS type manufactured by Toshiba Machine Co., Ltd.) having a screw diameter of 26 mm. In the middle, deaeration was performed at a vent pressure reduction of -0.099 MPa (gauge pressure), the strands were taken out in a strand shape, cooled and solidified in a water tank, and cut with a pelletizer, to obtain resin pellets made of a polyester resin composition. The melt kneading was performed under the conditions of an extruder barrel temperature setting of 200 ° C., a discharge rate of 20 kg / h, and a screw rotation speed of 300 rpm.
After the obtained resin pellets are sufficiently dried, the resin pellet content is 1 mass with respect to polyethylene terephthalate resin (unitika Co., Ltd. PET resin, intrinsic viscosity 0.60, acid value 2 mgKOH / g) as a matrix resin. %, And then kneaded at a temperature of 280 ° C. and extruded from a T-die. The sheet was brought into close contact with a cooling drum whose temperature was adjusted to 35 ° C. by an electrostatic application method and rapidly cooled to obtain a sheet having a thickness of 260 μm. The sheet was stretched 3 times in the machine direction at 90 ° C., and stretched 4.0 times in the transverse direction at 120 ° C., followed by heat treatment at 230 ° C. for 5 seconds to form a polyethylene terephthalate having a thickness of 25 μm. A film was obtained.

Examples 2 to 21, 23 to 53, Comparative Examples 1 to 8
Except having changed so that the kind and compounding ratio of the copolyester resin to be used and a carbodiimide compound may be changed as shown in Tables 5-7, operation similar to Example 1 was performed and the resin pellet which consists of a polyester resin composition was obtained. . In Examples 52 and 53, two types of copolymer polyester resins were used in the ratios (mass ratios) described in the table.
Using the obtained resin pellets, a 25-μm thick polyethylene terephthalate film was obtained in the same manner as in Example 1.

Examples 22, 54
Examples 22 and 54 are the same as those in Examples 1 and 23 except that the barrel temperature setting of the extruder was changed from 200 ° C. to 230 ° C. in the melt-kneading in the twin-screw extruder. Resin pellets made of the composition were obtained.
Using the obtained resin pellets, a 25-μm thick polyethylene terephthalate film was obtained in the same manner as in Example 1.

  The obtained polyethylene terephthalate film was evaluated for compatibility, stretchability, and hydrolysis resistance, and for Examples 23 to 54 and Comparative Examples 5 to 8, the viscosity change was also evaluated.

  The polyester resin compositions obtained in Examples 1 to 54 were excellent in handling as a master batch, and the molded articles obtained using the polyester resin compositions were excellent in compatibility, stretchability, and hydrolysis resistance. . Since the polyester resin compositions obtained in Examples 23 to 28 and 30 to 54 used the copolymerized polyester resin (B) containing an organic sulfonate compound, the obtained molded product was inhibited from increasing in viscosity. It was what was done.

In Comparative Examples 1 and 5, the carbodiimide compound was added directly to the matrix resin without adding the resin pellets of the polyester resin composition containing the copolymerized polyester resin and the carbodiimide compound. In Comparative Examples 2 and 6, Since the content of the copolyester resin in the polyester resin composition was less than the amount specified in the present invention, both were inferior in compatibility.
In Comparative Examples 3 and 7, the content of the copolyester resin in the polyester resin composition exceeded the amount specified in the present invention, and thus the hydrolysis resistance of the molded product could not be sufficiently improved.
In Comparative Examples 4 and 8, since a resin composition containing a carbodiimide compound was not used, the hydrolysis resistance of the molded article was low and the stretchability was inferior.

The inventor of the present invention has reached 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 as follows.
(1) A polyester resin composition containing a copolymerized polyester resin (A) and a carbodiimide compound (B),
The weight ratio of the copolymerized polyester (A) and the carbodiimide compound (B) (A / B) is Ri 10/90 to 85/15 der,
Copolyester resin (A), an organic sulfonate compound polyester resin composition characterized that you containing 0.05 to 10 mol% as a copolymer component.
(2) The polyester according to (1), wherein the copolyester resin (A) is a crystalline polyester resin having a melting point of 210 ° C. or lower and / or an amorphous polyester resin having a glass transition temperature of 50 ° C. or higher. Resin composition .
(3 ) A resin pellet comprising the polyester resin composition as described in (1) or (2) above.
( 4 ) A method for producing resin pellets as described in ( 3 ) above, wherein the copolymerized polyester resin (A) and the carbodiimide compound (B) are melt-kneaded at a temperature of 220 ° C. or lower. Pellet manufacturing method.
( 5 ) A molded article obtained by melt-molding a thermoplastic resin containing the resin pellet described in ( 3 ) above.

Reference example 1
After uniformly mixing 35 parts by mass of the copolymerized polyester resin (A1) and 65 parts by mass of the carbodiimide compound (B1), a total charge of 3 kg is supplied with a loss-in-weight continuous quantitative supply device (CE-W-1 type manufactured by Kubota Corporation). It was used for melt kneading by supplying it to the main supply port of a twin screw extruder (TEM26SS type manufactured by Toshiba Machine Co., Ltd.) having a screw diameter of 26 mm. In the middle, deaeration was performed at a vent pressure reduction of -0.099 MPa (gauge pressure), the strands were taken out in a strand shape, cooled and solidified in a water tank, and cut with a pelletizer, to obtain resin pellets made of a polyester resin composition. The melt kneading was performed under the conditions of an extruder barrel temperature setting of 200 ° C., a discharge rate of 20 kg / h, and a screw rotation speed of 300 rpm.
After the obtained resin pellets are sufficiently dried, the resin pellet content is 1 mass with respect to polyethylene terephthalate resin (unitika Co., Ltd. PET resin, intrinsic viscosity 0.60, acid value 2 mgKOH / g) as a matrix resin. %, And then kneaded at a temperature of 280 ° C. and extruded from a T-die. The sheet was brought into close contact with a cooling drum whose temperature was adjusted to 35 ° C. by an electrostatic application method and rapidly cooled to obtain a sheet having a thickness of 260 μm. The sheet was stretched 3 times in the machine direction at 90 ° C., and stretched 4.0 times in the transverse direction at 120 ° C., followed by heat treatment at 230 ° C. for 5 seconds to form a polyethylene terephthalate having a thickness of 25 μm. A film was obtained.

Examples 2 to 28 , 30 to 53, Reference Examples 2 to 21, 23, Comparative Examples 1 to 8
Except having changed the kind of copolyester resin and carbodiimide compound to be used, and the blending ratio as shown in Tables 5 to 7, the same operation as in Reference Example 1 was performed to obtain resin pellets made of the polyester resin composition. . In Examples 52 and 53, two types of copolymer polyester resins were used in the ratios (mass ratios) described in the table.
Using the obtained resin pellets, a 25 μm thick polyethylene terephthalate film was obtained in the same manner as in Reference Example 1 .

Example 5 4 , Reference Example 22
Example 5 4 and Reference Example 22 were the same as Example 2 3 and Reference Example 1 , respectively, except that the barrel temperature setting of the extruder was changed from 200 ° C. to 230 ° C. in the melt-kneading in the twin-screw extruder. Operation was performed and the resin pellet which consists of a polyester resin composition was obtained.
Using the obtained resin pellets, a 25 μm thick polyethylene terephthalate film was obtained in the same manner as in Reference Example 1 .

The obtained polyethylene terephthalate film was evaluated for compatibility, stretchability, and hydrolysis resistance. For Examples 23 to 28 , 30 to 54, Reference Example 23, and Comparative Examples 5 to 8, evaluation of viscosity change was also performed. went.

The polyester resin compositions obtained in Examples 23 to 28 and 30 to 54 are excellent in handling as a masterbatch, and molded articles obtained using the polyester batch are excellent in compatibility, stretchability, and hydrolysis resistance. It was a thing. Since the polyester resin compositions obtained in Examples 23 to 28 and 30 to 54 used the copolymerized polyester resin (B) containing an organic sulfonate compound, the obtained molded product was inhibited from increasing in viscosity. It was what was done.

The inventor of the present invention has reached 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 as follows.
(1) A polyester resin composition containing a copolymerized polyester resin (A) and a carbodiimide compound (B),
The mass ratio (A / B) of the copolymerized polyester resin (A) and the carbodiimide compound (B) is 10/90 to 85/15,
Copolyester resin (A) contains 0.05-10 mol% of organic sulfonate compounds as a copolymerization component, The polyester resin composition characterized by the above-mentioned.
(2) The polyester according to (1), wherein the copolyester resin (A) is a crystalline polyester resin having a melting point of 210 ° C. or lower and / or an amorphous polyester resin having a glass transition temperature of 50 ° C. or higher. Resin composition.
(3) A resin pellet comprising the polyester resin composition described in (1) or (2) above.
(4) A method for producing resin pellets as described in (3) above, wherein the copolymer polyester resin (A) and the carbodiimide compound (B) are melt-kneaded at a temperature of 220 ° C. or lower. Pellet manufacturing method.
(5) above (1) or (2) the polyester resin composition according molded article which is characterized by containing the other thermoplastic resin.

Claims (6)

  A polyester resin composition containing a copolyester resin (A) and a carbodiimide compound (B), wherein the mass ratio (A / B) of the copolyester resin (A) and the carbodiimide compound (B) is from 10/90 to A polyester resin composition characterized by being 85/15.   The polyester resin composition according to claim 1, wherein the copolyester resin (A) is a crystalline polyester resin having a melting point of 210 ° C or lower and / or an amorphous polyester resin having a glass transition temperature of 50 ° C or higher. .   The polyester resin composition according to claim 1 or 2, wherein the copolymerized polyester resin (A) contains 0.05 to 10 mol% of an organic sulfonate compound as a copolymerization component.   A resin pellet comprising the polyester resin composition according to claim 1.   It is a method for manufacturing the resin pellet of Claim 4, Comprising: Copolyester resin (A) and a carbodiimide compound (B) are melt-kneaded at the temperature of 220 degrees C or less, The manufacturing method of the resin pellet characterized by the above-mentioned. . A molded article characterized in that the resin pellet according to claim 4 is contained in a thermoplastic resin and melt-molded.