TW201643218A - Polyester resin composition, preparation method thereof and formed product using polyester resin composition - Google Patents

Abstract

This invention discloses a polyester resin composition containing polyester resin (A) and a carbodiimide compound (B) represented by the following general formula (1); based on the total weight (100 parts by mass) of the polyester resin (A) and the carbodiimide compound (B), the content (parts by mass) of the carbodiimide compound (B) is 0.1-8.

Description

Polyester resin composition, method for producing the polyester resin composition, and molded article using the polyester resin composition

The present invention relates to a polyester resin composition containing a polyester resin and a carbodiimide compound, a method for producing the polyester resin composition, and a molded article using the polyester resin composition.

Polyester resin is widely used in films, sheets, and the like because it is excellent in transparency, mechanical strength, melt stability, solvent resistance, and recyclability, and is also used in recent years in the frame of home electric appliances or OA equipment. Body and so on.

However, since the polyester resin has a property of being easily hydrolyzed compared to the conventional general-purpose resin, a method of adding a carbodiimide compound has been explored for the purpose of improving hydrolysis resistance.

By incorporating a carbodiimide compound into a polyester resin and performing molding, the carbodiimide compound can complement the carboxyl group in the polyester resin or the carboxyl group generated by decomposition of the ester group at a high temperature kneading, and suppress The initial performance of the formed product is degraded. Further, by retaining the carbodiimide compound in the molded article, the durability of the molded article can be improved.

For example, Patent Document 1 discloses a hydrolysis-resistant stabilizer for an unsaturated polyester resin which is characterized by a specific aliphatic or aromatic A hydrolysis-resistant stabilizer for an unsaturated polyester resin having a carbodiimide compound or the like as a main component.

Patent Document 2 discloses a structure having a carbodiimide structure, even a urethane structure, a urea structure, or both, which is solid at 25 ° C, and the carbodiimide structure is bonded to a non-aromatic bond. The carbodiimide of a carbon atom serves as a stabilizer for the cleavage by hydrolysis of a polyester-based plastic.

Patent Document 3 discloses an aliphatic polyester resin composition containing an aliphatic polyester resin, a hydrolysis inhibitor, and a non-reactive fluorenone for the purpose of obtaining an aliphatic polyester resin composition excellent in moisture and heat aging resistance. . There is disclosed a technique in which a carbodiimide-based compound is used as a hydrolysis inhibitor, and an adipate or the like is used as a plasticizer.

Patent Document 4 discloses that a polyester segment having a number average molecular weight of 5,000 to 30,000 and a polycarbodiimide segment are linked by a urethane bond for the purpose of having both hydrolysis resistance and bending workability. A polyester-polycarbodiimide copolymer having a chemical structure and an adhesive composition containing the same.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. Hei 9-249801

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2000-256436

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2009-256405

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2013-75972

In the technique of Patent Document 1, the hydrolysis of the polyester resin can be suppressed However, in the case of melt-kneading and forming, the carboxyl group in the polyester resin reacts violently with the carbodiimide group, and there is an increase in viscosity or gelation, and it is difficult to produce a stable molded product. .

In the technique of Patent Document 2, a solid carbodiimide can be obtained, and by adding the carbodiimide to the polyester-based plastic, the strength retention at a low temperature can be improved, but the hydrolysis resistance is low, and The problem of poor strength retention after storage under high temperature and high humidity.

In the technique of Patent Document 3, the formability can be improved by using a plasticizer. However, when a general plasticizer such as phthalic acid ester is used, there is a possibility of overflow from the molded body depending on the amount of addition, and there is a molded product. The decline in physical properties, or the occurrence of environmental and health disorders due to spillage. Further, since these plasticizers do not have reactivity with a carboxyl group, the hydrolysis inhibiting effect of the carbodiimide compound may be lowered, and improvement is desired.

In the technique of Patent Document 4, the coating film having excellent hydrolysis resistance and bending workability is obtained. However, since the polyester-polycarbodiimide copolymer is used as a main component, the application is limited, and Productivity and cost are also expected to be further improved.

An object of the present invention is to provide a polyester resin composition which is excellent in hydrolysis resistance and overflow resistance, and which does not cause a large increase in melt viscosity and solution viscosity, a method for producing the polyester resin composition, and a method for producing the polyester resin composition. A molded article of the polyester resin composition is used.

The inventors of the present invention repeatedly and carefully explored the results of the above-mentioned objects and found that they were blended in a specific ratio with respect to the polyester resin. The above problems can be solved by combining a specific carbodiimide compound, and the present invention is completed.

In other words, the present invention is a polyester resin composition described below, a method for producing the polyester resin composition, and a molded article using the polyester resin composition.

[1] A polyester resin composition comprising a polyester resin composition of a polyester resin (A) and a carbodiimide compound (B) represented by the following formula (1) The content of the carbodiimide compound (B) is 0.1 to 8 parts by mass based on 100 parts by mass of the total of the polyester resin (A) and the carbodiimide compound (B);

In the formula, R ¹ represents a residue of a compound having one functional group reactive with isocyanate, and R ² represents a divalent aliphatic group having at least one alicyclic structure. However, -N=C=N- is a direct bond to the alicyclic structure of R ² . R ³ represents a divalent residue of the polyester diol. X represents a group selected from the following general formulae (2) to (4).

m represents the number from 1 to 20, n represents the number from 1 to 20, and p represents the number from 1 to 5. A plurality of R ² and X may be the same or different.

[2] The polyester resin composition according to [1], wherein the polyester diol has a number average molecular weight of 1,000 to 40,000.

[3] The polyester resin composition according to [1] or [2] wherein the R ² is a divalent residue of dicyclohexylmethane-4,4'-diisocyanate.

[4] The polyester resin composition according to any one of [1] to [3] wherein the carbodiimide compound (B) has a carbodiimide equivalent of from 100 to 1,000.

[5] The polyester resin composition according to any one of [1] to [4] wherein the polyester resin (A) is selected from the group consisting of polyethylene terephthalate and polyterephthalic acid. One or more of butylene diester, polybutylene succinate, polylactic acid, and polyhydroxyalkanoic acid.

[6] The polyester resin composition according to any one of [1] to [5] wherein the compound having one functional group reactive with isocyanate is a monool, a monophenol, a monoisocyanate, or Monoamine.

[7] The method for producing a polyester resin composition according to any one of [1] to [6] wherein the polyester resin (A) and the carbodiimide compound (B) are used. Melt and knead.

[8] The method for producing a polyester resin composition according to [7], wherein the carbodiimide compound (B) is granulated.

[9] A molded article obtained by molding the polyester resin composition according to any one of [1] to [6].

According to the present invention, it is possible to provide a polyester resin composition which is excellent in hydrolysis resistance and overflow resistance, and which does not cause a large increase in melt viscosity and solution viscosity, a method for producing the polyester resin composition, and A molded article of the polyester resin composition is used.

[Formation of the Invention]

[Polyester resin composition]

The polyester resin composition of the present invention contains a polyester resin composition of the polyester resin (A) and the carbodiimide compound (B) represented by the following formula (1), and is characterized by The total amount of the polyester resin (A) and the carbodiimide compound (B) is 100 parts by mass, and the content of the carbodiimide compound (B) is 0.1 to 8 parts by mass.

In the formula, R ¹ represents a residue of a compound having one functional group reactive with isocyanate, and R ² represents a divalent aliphatic group having at least one alicyclic structure. However, -N=C=N- is a direct bond to the alicyclic structure of R ² . R ³ represents a divalent residue of the polyester diol. X represents a group selected from the following general formulae (2) to (4).

m represents the number from 1 to 20, n represents the number from 1 to 20, and p represents the number from 1 to 5. A plurality of R ² and X may be the same or different.

The polyester-based resin composition of the present invention is excellent in both hydrolysis resistance and overflow resistance, and the reason why the melt viscosity and the solution viscosity are not greatly increased is not determined, but it is considered as follows.

The carbodiimide compound (B) represented by the formula (1) contains the polyester-based resin composition of the present invention, and since it has a polyester segment between the polycarbodiimide groups, it can be used in the polycarbodiimide. By giving an appropriate distance between the amine groups, according to the above, the rapid increase in viscosity due to the crosslinking reaction at the time of melt kneading can be suppressed.

Further, since the carbodiimide compound (B) has a polyester segment between the polycarbodiimide groups, the solubility of the carbodiimide compound (B) in the polyester resin (A) can be improved. Since the dispersibility is suppressed, the melt viscosity and the increase in the viscosity of the solution can be suppressed, and a molded article excellent in hydrolysis resistance and overflow resistance can be obtained.

Further, as the polycarbodiimide, by using a polycarbodiimide having a specific alicyclic structure, even a lower carbodiimide concentration than the conventional aliphatic polycarbodiimide can be exerted. Excellent hydrolysis resistance.

<Polyester resin (A)>

The polyester resin (A) can be used as long as it is a resin having an ester group, and is not particularly limited.

As the polyester resin (A) as described above, for example, polyethylene terephthalate (hereinafter also referred to as "PET") or polybutylene succinate (hereinafter also referred to as "PBS" can be used. "), polybutylene succinate adipate (hereinafter also referred to as "PBSA"), polybutylene adipate terephthalate (polybutylene adipate terephthalate) (hereinafter also referred to as "PBAT"), polybutylene terephthalate (hereinafter also referred to as "PBT"), polyethylene naphthalate, polyarylate, para-benzene One or more kinds of polyhydroxyalkanoic acid (hereinafter also referred to as "PHA") such as polyethylene diester-isophthalate copolymer, polylactic acid (hereinafter also referred to as "PLA"), and polybutyric acid (hereinafter also referred to as "PHA") .

Among these, from the viewpoint of economy and processability, it is preferably selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, polybutylene succinate, polylactic acid, and poly One or more kinds of hydroxyalkanoic acids are more preferably polyethylene terephthalate.

The content of the polyester resin (A) in the polyester resin composition of the present invention is preferably from 80 to 99.9% by mass, from the viewpoint of the hydrolysis resistance, the melt viscosity, and the solution viscosity of the polyester resin composition. More preferably, it is 85 to 99.8 mass%, particularly preferably 90 to 99.7% by mass, and most preferably 95 to 99.5% by mass.

<Carbodiimide Compound (B)>

The carbodiimide compound (B) used in the present invention is represented by the following formula (1).

In the formula, R ¹ represents a residue of a compound having one functional group reactive with isocyanate, and R ² represents a divalent aliphatic group having at least one alicyclic structure. However, -N=C=N- is a direct bond to the alicyclic structure of R ² . R ³ represents a divalent residue of the polyester diol. X represents a group selected from the following general formulae (2) to (4).

m represents the number from 1 to 20, n represents the number from 1 to 20, and p represents the number from 1 to 5. A plurality of R ² and X may be the same or different.

In the formula (1), R ¹ represents a residue of a compound having a functional group reactive with isocyanate (hereinafter also referred to as "blocking agent (a)" or "component (a)").

The carbodiimide compound (B) used in the present invention can improve the carbodiimide compound (B) to the polyester resin by sealing the residual terminal isocyanate as the component (a) as a terminal blocking agent. The compatibility of the polyester resin composition and the storage stability of the polyester resin composition can improve the quality.

[Capping agent; (a) component]

The component (a) may, for example, be a monool, a monophenol, a monoisocyanate or a monoamine.

Examples of the monool include methanol, ethanol, cyclohexanol, polyethylene glycol monomethyl ether, and polypropylene glycol monomethyl ether.

Examples of the monophenol include phenol, cresol, xylenol, and naphthol.

Examples of the monoisocyanate include a lower alkyl monoisocyanate such as methyl isocyanate, ethyl isocyanate, propyl isocyanate, or a second or a third butyl isocyanate; and an alicyclic aliphatic monoisocyanate such as cyclohexyl isocyanate. An aromatic monoisocyanate such as phenyl isocyanate, tolyl isocyanate, dimethylphenyl isocyanate or 2,6-diisopropylphenyl isocyanate.

Examples of the monoamine include a primary amine such as butylamine or cyclohexylamine; and a secondary amine such as diethylamine, dibutylamine or dicyclohexylamine.

From the viewpoint of improving the compatibility between the carbodiimide compound (B) and the polyester resin (A) and the storage stability of the polyester resin composition, among these, a monool or a monoisocyanate is preferable. Preferably, it is a monool, particularly preferably polyethylene glycol monomethyl ether or polypropylene glycol monomethyl ether, and most preferably polyethylene glycol monomethyl ether.

In the formula (1), R ² represents a divalent aliphatic group having at least one alicyclic structure. However, -N=C=N- is a direct bond to the alicyclic structure of R ² .

The carbodiimide compound (B) used in the present invention can directly increase the reactivity with a carboxyl group by directly bonding a carbodiimide group (-N=C=N-) to an alicyclic structure, even if it is more conventional. The aliphatic carbodiimide has a lower carbodiimide concentration and also exhibits excellent hydrolysis resistance.

Examples of the divalent aliphatic group having at least one alicyclic structure include a diisocyanate having at least one alicyclic structure (hereinafter also referred to as "diisocyanate (b)" or "(b) component"). Valence residue.

[diisocyanate; (b) component]

Examples of the component (b) include cyclohexane-1,4-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, and methylcyclohexane diisocyanate. Among the above, from the viewpoint of hydrolysis resistance, melt viscosity, and solution viscosity of the polyester resin composition, dicyclohexylmethane-4,4'-diisocyanate is preferred.

In the formula (1), R ³ represents a divalent residue of a polyester diol (hereinafter also referred to as "polyester diol (c)" or "(c) component").

The carbodiimide compound (B) used in the present invention has good compatibility with the polyester resin (A) by having a polyester segment as R ³ and can be improved in the polyester resin (A). The solubility and dispersibility of the carbodiimide compound (B) can suppress the increase in melt viscosity and solution viscosity, and at the same time improve hydrolysis resistance and overflow resistance.

[polyester diol; (c) component]

The component (c) is not particularly limited as long as it is a diol having an ester group, and examples thereof include a chemical structure obtained by polycondensation of a polycarboxylic acid and a polyhydric alcohol.

As the polycarboxylic acid, it is selected from the group consisting of succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, tridecanedioic acid, dimer acid and their hydrides. An aliphatic dibasic acid such as an aliphatic dibasic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid or 1,4-cyclohexanedicarboxylic acid, or the like One or more kinds of dibasic acids such as an aromatic dibasic acid such as phthalic acid, isophthalic acid, phthalic acid or naphthalene dicarboxylic acid are preferred.

Further, as the polyol, a solvent selected from the group consisting of ethylene glycol, propylene glycol, butanediol, neopentyl glycol, methyl pentanediol, pentanediol, hexanediol, heptanediol, octanediol, and decanediol is used. And alicyclic diols such as decanediol, dodecanediol, and dimer diol, alicyclic diols such as cyclohexane diol and hydrogenated hydric diol, and xylylene glycol One or more kinds of diols such as an aromatic ring diol are preferable.

From the viewpoint of hydrolysis resistance, melt viscosity, and solution viscosity of the polyester resin composition, the number average molecular weight of the component (c) is preferably from 1,000 to 40,000, more preferably from 1,500 to 35,000, particularly preferably from 2,000 to 2,000. 30,000. Further, the number average molecular weight was measured by colloidal chromatography using polystyrene as a standard substance.

In the general formula (1), m represents a number of from 1 to 20, preferably from 2 to 18, more preferably from 4 to 16, from the viewpoints of hydrolysis resistance, melt viscosity, and solution viscosity of the polyester resin composition. Very good for 6~15.

From the same viewpoint, in the general formula (1), n represents a number of 1 to 20, preferably 2 to 18, more preferably 4 to 16, and particularly preferably 6 to 15.

From the same viewpoint, in the general formula (1), p represents a number of 1 to 5, preferably 1 to 4, more preferably 1 to 3.

(carbodiimide equivalent)

From the viewpoints of hydrolysis stability, melt viscosity, and solution viscosity of the polyester resin composition, the carbodiimide equivalent of the carbodiimide compound (B) (the amount of the carbodiimide group per 1 mol of the formula) Good for 100~1,000, better for 150~850, especially good for 200~600.

(content of carbodiimide compound (B))

The carbon dioxide is a total amount of the polyester resin (A) and the carbodiimide compound (B) in terms of the hydrolysis resistance, the melt viscosity, and the solution viscosity of the polyester resin composition. The content of the imine compound (B) is 0.1 to 8 parts by mass, preferably 0.2 to 7 parts by mass, more preferably 0.3 to 6 parts by mass, particularly preferably 0.5 to 5 parts by mass.

<Method for Producing Carbonodiimide Compound (B)>

The carbodiimide compound (B) used in the present invention can be produced by a known method.

For example, (i) the diisocyanate (b) is subjected to a carbodiimidation reaction in the presence of a catalyst to obtain a polycarbodiimide (hereinafter also referred to as "(d) component"). Next, the blocking agent (a) and the polyester diol (c) are added to the component (d) to carry out copolymerization. a method of combining and capping the reaction, (ii) subjecting the diisocyanate (b), the polyester diol (c), and the blocking agent (a) to a carbodiimidation reaction and copolymerization in the presence of a catalyst a reaction and a method of blocking the reaction, (iii) copolymerizing the diisocyanate (b) with the polyester diol (c), and then adding a blocking agent (a) and a catalyst to carry out carbodiimization Reaction and blocking reaction methods, and the like.

From the viewpoint of productivity, among these, it is preferable to manufacture by the method of the above (i).

(Manufacture of polycarbodiimide (d))

The polycarbodiimide (d) can be subjected to a carbon diimide (b) in a solvent-free or inert solvent by using an organophosphorus compound or an organometallic compound or the like as a carbodiimide catalyst. Amination reaction to synthesize.

Specific examples of the carbodiimidation catalyst include 3-methyl-1-phenyl-2-cyclophosphene-1-oxide and 3-methyl-1-ethyl- 2-cyclophosphene-1-oxide, 1,3-dimethyl-2-cyclophosphene-1-oxide, 1-phenyl-2-cyclophosphene-1-oxide, 1-ethyl -2-cyclophosphene-1-oxide, 1-methyl-2-cyclophosphene-1-oxide, and the like. Among these, 3-methyl-1-phenyl-2-cyclophosphene-1-oxide which is industrially easy to obtain is preferable. The carbodiimide catalyst may be used singly or in combination of two or more.

From the viewpoint of productivity, the reaction temperature of the carbodiimidation reaction is preferably 70 to 250 ° C, more preferably 100 to 230 ° C, and particularly preferably 150 to 200 ° C.

From the same point of view, the reaction time of the aforementioned carbodiimidation reaction, It is preferably from 1 to 50 hours, more preferably from 10 to 40 hours, and particularly preferably from 20 to 30 hours.

The amount of the catalyst to be used may be appropriately determined depending on the type of the catalyst to be used, but it is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, per 100 parts by mass of the diisocyanate (b). It is 0.2 to 1 part by mass.

(copolymerization)

The copolymerization reaction can be carried out by reacting the polycarbodiimide (d), the terminal blocking agent (a), and the polyester diol (c) obtained above under heating. The order of adding the component (d), the component (a), and the component (c) is not particularly limited, but it is preferable to add the component (d), the component (a) and the component (c) from the viewpoint of workability at the time of synthesis. From the viewpoint of suppressing the side reaction, the component (d) and the component (a) are added, and after confirming the completion of the reaction between the component (d) and the component (a), it is preferred to add the component (c).

From the viewpoints of hydrolysis resistance, melt viscosity, and solution viscosity of the obtained polyester resin composition, a mixture ratio of polycarbodiimide (d) to polyester diol (c), polycarbodiimide ( The ratio of the molar number of the terminal isocyanate group of d) to the molar number of hydroxyl groups of the polyester diol (c) [NCO(d)/OH(c)] is preferably 1.20 to 2, more preferably 1.25. ~2, especially good for 1.33~2.

From the viewpoint of productivity, the reaction temperature of the above copolymerization reaction is preferably 40 to 250 ° C, more preferably 90 to 220 ° C, and particularly preferably 130 to 200 ° C.

From the same viewpoint, the reaction time of the above copolymerization reaction is preferably from 5 minutes to 20 hours, more preferably from 30 minutes to 10 hours, particularly preferably from 1 hour to 3 hours.

The obtained carbodiimide compound (B) and the polyester resin (A) are melt-mixed from the viewpoint of productivity of the polyester resin composition. It is preferred to carry out the granulation of the carbodiimide compound (B) component, or to granulate only the carbodiimide compound (B) component. Granulation can be carried out by processing into a pellet shape by a known granulator.

<Other ingredients>

In the polyester resin composition, additives such as a pigment, a filler, a leveling agent, a surfactant, a dispersant, an ultraviolet absorber, an antioxidant, a flame retardant, and a colorant may be appropriately blended as needed.

<Total content of polyester resin (A) and carbodiimide compound (B)>

The polyester resin (A) and the carbodiimide compound (B) in the polyester resin composition of the present invention from the viewpoints of processability, hydrolysis resistance, melt viscosity, and solution viscosity of the polyester resin composition The total content of the compound is preferably from 90 to 100% by mass, more preferably from 92 to 100% by mass, particularly preferably from 95 to 100% by mass.

[Method for Producing Polyester Resin Composition]

The method for producing the polyester resin composition of the present invention is a method of melt-kneading the polyester resin (A) and the carbodiimide compound (B).

In the production method of the present invention, by using the carbodiimide compound (B), a large increase in the melt viscosity can be suppressed, and workability at the time of melt kneading can be improved. Therefore, the productivity of the polyester resin composition is excellent.

The melt kneading can be carried out using a known mixer or the like having a heating means. The order in which the materials are put into the mixer is not particularly limited, but the base polyester resin (A) is first charged, and after melting, the carbodiimide compound (B) and other components to be added as needed are added. More investment miss you.

The time of the melt kneading can be appropriately determined depending on the shape of the screw, the rotation speed, etc., and is usually 1 to 30 minutes, preferably 1 to 10 minutes, more preferably 1 to 5 minutes. Further, the temperature at the time of melt kneading varies depending on the type of the polyester resin (A) to be used, but is usually about 150 to 350 ° C, preferably 200 to 320 ° C, more preferably 240 to 300 ° C.

The carbodiimide compound (B) used in the production method of the present invention is preferably granulated.

In the conventional polycarbodiimide additive, since the melting point is low, when the extruder is added by using a feeder or the like, the input port is partially melted and the input becomes difficult. On the other hand, the powdered polycarbodiene is used. When the amine additive and the polyester resin particles are added by dry blending, the concentration of segregation of the carbodiimide additive may be uneven due to the difference in shape. Further, since the compatibility between the polycarbodiimide additive and the polyester resin (A) is slightly inferior, it is difficult to uniformly disperse in the molded body at a low concentration.

On the other hand, the carbodiimide compound (B) used in the present invention can be granulated and dry blended with the polyester resin (A), and the shaped body can be processed. In particular, the carbodiimide compound (B) having a large molecular weight has a high melting point and thus can be easily granulated. It is considered that it is difficult to cause segregation due to the granules, and the polyester segment is present in the molecule, so that it has good compatibility with the polyester resin (A), and can be uniformly dispersed in the polyester resin even at a low concentration. In the molded body of (A).

In addition, it is considered that since the polyester resin (A) can be directly mixed by dry blending, it is not necessary to prepare a master batch for each type of the polyester resin (A), and the number of manufacturing steps can be reduced. Avoid according to the masterbatch Inactivation caused by the thermal history (reaction of ester resin with carbodiimide).

[Formed product using a polyester resin composition]

The molded article of the present invention is a molded article formed by using the polyester resin composition of the present invention.

When a molded article is obtained from the polyester resin composition of the present invention, it may be formed by extrusion molding, injection molding, blow molding, or the like during the melt-kneading, or may be temporarily compounded into a master batch or the like, and thereafter, The material is melted and kneaded for forming.

In the polyester resin composition of the present invention, the melt viscosity does not increase significantly during molding in any molding method, and therefore workability is good. In addition, since the molded article molded by the polyester resin composition of the present invention has excellent hydrolysis resistance, it is excellent in various properties such as strength.

[Examples]

Hereinafter, the present invention will be more specifically described by way of Examples and Comparative Examples, but the present invention is not limited thereto.

[evaluation project]

(1) Solution viscosity

The melt-kneaded polyester resin composition was dried at 130 ° C for 4 hours, and 0.15 g of the dried resin was dissolved in 30 mL of a mixed solution of phenol and tetrachloroethane (phenol / tetrachloroethane = 1 / 1 (weight Ratio)) and measured at 30 ° C using a Cannon-Fenske viscometer. The unit is (dl/g).

(2) Melt flow rate (MFR) (melt viscosity)

The melt-kneaded polyester resin composition was dried at 130 ° C for 4 hours, and was tested at a test temperature of 270 ° C using a Melt-Flow Indexer (VR-4100, manufactured by Ushimashima Co., Ltd.) as a melt viscosity measuring device. The melt flow rate (MFR) was measured at a load of 2.16 kgf. The unit is (g/10min). The obtained MFR (g/10 min) was used as an index of the melt viscosity. It means that the larger the MFR value, the lower the melt viscosity.

(3) Strength retention rate (hydrolysis resistance test)

The melt-kneaded polyester resin composition was subjected to flat pressing at a temperature equal to or higher than the softening point to prepare a sheet having a thickness of about 300 μm, and a rectangular sheet having a width of 10 mm and a length of 70 mm was produced from the sheet.

Next, the tensile strength of the produced rectangular sheet was measured by a tensile tester. Furthermore, the prepared rectangular sheet was placed in a highly accelerated life tester (HAST CHAMBER EHS-210M manufactured by ESPEC Co., Ltd.), and the sample was taken out after 24 hours and after 40 hours at 121 ° C and 100% Rh. The tensile strength of the rectangular sheet was measured by a tensile tester. The average value of the tensile strengths of the five sheets before and after the test was calculated, and the strength retention ratio was determined as an evaluation index of hydrolysis resistance by the following formula.

Strength retention rate (%) = [(average of tensile strength after test) / (average of tensile strength before test)] × 100

(4) Evaluation of spill resistance

The melt-kneaded polyester-based resin composition was pressed under the conditions described in the above (3) strength retention ratio, and the presence or absence of overflow was visually observed for the obtained sheet.

Synthesis Example 1 (Synthesis of carbodiimide compound P1)

100 parts by mass of 4,4'-dicyclohexylmethane diisocyanate and 0.5 parts by mass of a carbodiimide catalyst (3-methyl-1-phenyl-2-cyclophosphene-1-oxide) are added thereto. A reaction vessel equipped with a reflux tube and a stirrer was stirred at 185 ° C for 24 hours under a nitrogen stream to obtain an isocyanate terminal poly 4,4'-dicyclohexyl group. Methane carbodiimide.

The absorption peak due to the carbodiimide group before and after the formation of a wavelength of 2150 cm ^{-1 was} confirmed by infrared light absorption (IR) spectroscopy. The residual isocyanate group concentration (hereinafter also referred to as "NCO%") measured by the titration measurement is 3.78%, and the number of repeating units of the constituent unit represented by (-R ² -N=C=N-) (hereinafter also referred to as The "degree of aggregation" is 9.0.

Next, the isocyanate terminal poly(4,4'-dicyclohexylmethane carbodiimide obtained above was heated to 150 ° C, and polyethylene glycol monomethyl ether (molecular weight 208) of 7.9 parts by mass and polyester diol were added thereto. ("VYLON 220" manufactured by Toyobo Co., Ltd., molecular weight: 3,000) 57.3 parts by mass, heated to 180 ° C, and reacted for 2 hours while stirring.

The absorption of the isocyanate group having a wavelength of 2,200 to 2,300 cm ^{-1 was} confirmed by infrared light absorption (IR) spectrum measurement, and the reactant was taken out from the reaction container, and cooled to room temperature to obtain a pale yellow transparent carbodiimide compound P1.

Synthesis Examples 2 to 4 (synthesis of carbodiimide compounds P2 to P4)

In the synthesis example 1, the carbodiimide compounds P2 to P4 were obtained in the same manner as in the synthesis example 1 except that the raw material composition and the reaction conditions were changed to the conditions described in Table 1.

Synthesis Example 5 (Synthesis of carbodiimide compound P5)

In the synthesis example 1, the reaction conditions and the type of the blocking agent were changed to the conditions described in Table 1, and the polyester diol ("VYLON 220" manufactured by Toyobo Co., Ltd., molecular weight 3,000) was not added. The carbodiimide compound P5 was obtained in the same manner as in Synthesis Example 1.

Synthesis Example 6 (Synthesis of particulate carbodiimide compound P6)

100 parts by mass of 4,4'-dicyclohexylmethane diisocyanate and 0.5 parts by mass of a carbodiimide catalyst (3-methyl-1-phenyl-2-cyclophosphene-1-oxide) are added thereto. A reaction vessel equipped with a reflux tube and a stirrer was stirred at 185 ° C for 28 hours under a nitrogen stream to obtain an isocyanate terminal poly 4,4'-dicyclohexylmethane carbodiimide. The absorption peak due to the carbodiimide group before and after the formation of a wavelength of 2150 cm ^{-1 was} confirmed by infrared light absorption (IR) spectroscopy. The result of measuring NCO% was 2.92% (degree of polymerization = 12.0).

Next, the isocyanate terminal poly 4,4'-dicyclohexylmethane carbodiimide obtained above was heated to 150 ° C, and 6.1 parts by mass of polyethylene glycol monomethyl ether (molecular weight 208) was added thereto, and heated to 180 ° C. After reacting for 1 hour while stirring, the reaction product was taken out from the reaction vessel, and cooled to room temperature to obtain a pale yellow transparent isocyanate tablet terminal 4,4'-dicyclohexylmethane carbodiimide.

Next, 90.6 parts by mass of the terminal isocyanate sheet 4,4'-dicyclohexylmethane carbodiimide and 44.0 parts by mass of polyester diol ("VYLON 220" manufactured by Toyobo Co., Ltd., molecular weight 3,000) were supplied to the biaxial extrusion. The machine (manufactured by Toyo Seiki Seisakusho Co., Ltd., LABO PLASTOMILL) was melt-kneaded at 180 ° C, and the obtained strands were processed into pellets by a pelletizer to obtain a particulate carbodiimide compound P6.

The obtained particulate carbodiimide compound P6 was confirmed to have disappeared absorption of an isocyanate group having a wavelength of 2,200 to 2,300 cm ^-1 by infrared light absorption (IR) spectrum measurement.

Synthesis Example 7 (Synthesis of particulate carbodiimide compound P7)

In Synthesis Example 6, except that the raw material composition and the reaction conditions were changed to The carbodiimide compound P7 was obtained in the same manner as in the synthesis example 6 except the conditions shown in Table 1.

Example 1

99.00 parts by mass of PET resin (manufactured by Sinopec) was melted at 270 ° C in a laboratory mixer, and then 1.00 parts by mass of the carbodiimide compound P1 obtained in Synthesis Example 1 was added and mixed for 3 minutes to obtain A polyester resin composition. The viscosity characteristics of the obtained polyester resin composition are shown in Table 2.

Examples 2 to 5 and Comparative Examples 1 to 4

In the same manner as in Example 1, except that the blending composition was changed to the blending composition shown in Table 2, a polyester resin composition was obtained. The viscosity characteristics of the obtained polyester resin composition are shown in Table 2.

Examples 6-8, Comparative Examples 5-8

The hydrolysis resistance of the polyester resin composition obtained in each of the examples and the comparative examples and the presence or absence of overflow were confirmed. The results are shown in Table 3.

According to Tables 2 to 3, the polyester resin composition of the present invention has the same carbodiimide group concentration as the comparative example, but has no significant increase in melt viscosity and solution viscosity, and hydrolysis resistance and Excellent resistance to spillage.

On the other hand, the polyester resin composition of Comparative Example 1 containing the carbodiimide compound P4 having a residue of a polycarbonate diol in the carbodiimide compound remarkably increases the melt viscosity.

Further, Comparative Examples 2 to 3 containing a carbodiimide compound P5 having no residue of a diol compound in the carbodiimide compound, and a carbon bisene containing a diisocyanate having no alicyclic structure as a diisocyanate The sheet obtained in Comparative Example 4 of the amine compound P3 (Comparative Examples 6 to 8) was inferior in hydrolysis resistance as compared with the sheets obtained in Examples 1 to 2 and 4 (Examples 6 to 8).

Claims (9)

A polyester resin composition comprising a polyester resin composition of a polyester resin (A) and a carbodiimide compound (B) represented by the following formula (1); The content of the carbodiimide compound (B) is 0.1 to 8 parts by mass based on 100 parts by mass of the total of the polyester resin (A) and the carbodiimide compound (B); wherein R ¹ represents a residue of a compound reactive with isocyanate, R ² represents a divalent aliphatic group having at least one alicyclic structure; wherein -N=C=N- is an alicyclic structure with R ² Direct bond; R ³ represents a divalent residue of the polyester diol; X represents a group selected from the following formulas (2) to (4); m represents a number from 1 to 20, and n represents from 1 to 20 The number, p represents the number of 1~5; the plurality of R ² and X respectively may be the same or different; The polyester resin composition of claim 1, wherein the polyester diol has a number average molecular weight of 1,000 to 40,000. The polyester resin composition of claim 1 or 2, wherein the R ² is a divalent residue of dicyclohexylmethane-4,4'-diisocyanate. The polyester resin composition according to any one of claims 1 to 3, wherein the carbodiimide compound (B) has a carbodiimide equivalent weight of from 100 to 1,000. The polyester resin composition according to any one of claims 1 to 4, wherein the polyester resin (A) is selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, and polyaluminum One or more of polybutylene succinate, polylactic acid, and polyhydroxyalkanoic acid. The polyester resin composition according to any one of claims 1 to 5, wherein the compound having one functional group reactive with isocyanate is a monool, a monophenol, a monoisocyanate, or a monoamine. The method for producing a polyester resin composition according to any one of claims 1 to 6, wherein the polyester resin (A) and the carbodiimide compound (B) are melt-kneaded. The method for producing a polyester resin composition according to claim 7, wherein the carbodiimide compound (B) is granulated. A molded article formed by using the polyester resin composition according to any one of claims 1 to 6.