KR102267208B1 - Polyester-based resin composition, production method for said polyester-based resin composition, and molded article using said polyester-based resin composition - Google Patents

Abstract

A polyester-based resin composition containing a polyester-based resin (A) and a carbodiimide compound (B) represented by the general formula (1), wherein the content of the carbodiimide compound (B) is a polyester-based resin (A) and 0.1 to 8 parts by weight of the polyester resin composition with respect to 100 parts by weight of the total amount of the carbodiimide compound (B).

Description

A polyester-based resin composition, a method for producing the polyester-based resin composition, and a molded article using the polyester-based resin composition TECHNICAL FIELD BASED RESIN COMPOSITION}

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

Polyester resins are widely used in films, sheets, and the like because of their excellent transparency, mechanical strength, melt stability, solvent resistance, and recyclability, and in recent years, they are also used in the cases of home appliances and OA equipment.

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

By mixing the carbodiimide compound with the polyester resin and molding it, the carbodiimide compound captures the carboxyl groups in the polyester resin or the carboxyl groups generated by the decomposition of the ester group when kneading at high temperature, thereby suppressing the initial performance degradation of the molded product. can do. In addition, the durability of the molded article is also improved by the presence of the carbodiimide compound in the molded article.

For example, Patent Document 1 discloses a hydrolysis-resistant stabilizer for an unsaturated polyester resin, characterized in that it contains a specific aliphatic or aromatic carbodiimide compound as a main component as a hydrolysis-resistant stabilizer for an unsaturated polyester resin. .

Patent Document 2 discloses that it has a carbodiimide structure as a stabilizer against cleavage by hydrolysis of a polyester plastic, and further has a urethane structure, a urea structure, or both structures, is solid at 25°C, and has a carbodiimide structure Carbodiimides bonded to non-aromatic carbon atoms are disclosed.

Patent Document 3 discloses an aliphatic polyester resin composition containing an aliphatic polyester resin, a hydrolysis inhibitor, and a non-reactive silicone for the purpose of obtaining an aliphatic polyester resin composition excellent in moisture and heat aging resistance. Among them, a technique using a carbodiimide-based compound as a hydrolysis inhibitor and an adipic acid ester as a plasticizer is disclosed.

Patent Document 4 discloses a polyester polycarbodiimide air having a chemical structure in which 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 achieving both hydrolysis resistance and bending workability. Adhesives and adhesive compositions containing them are disclosed.

Japanese Patent Application Laid-Open No. 9-249801 Japanese Patent Application Laid-Open No. 2000-256436 Japanese Patent Laid-Open No. 2009-256405 Japanese Patent Application Laid-Open No. 2013-75972

In the technique of Patent Document 1, hydrolysis of the polyester resin can be suppressed, but during melt-kneading and molding, the carboxy group in the polyester resin and the carbodiimide group react rapidly, resulting in an increase in viscosity or gelation. In some cases, it may be difficult to produce a stable molded product.

In the technique of Patent Document 2, solid carbodiimide can be obtained, and by adding this carbodiimide to a polyester-based plastic, the strength retention at low temperature can be improved, but hydrolysis resistance is low and storage at high temperature and high humidity There was a problem that the strength retention rate afterward was inferior.

In the technique of Patent Document 3, the moldability can be improved by using a plasticizer. However, when a general plasticizer such as phthalic acid ester is used, bleed-out may occur from the molded article depending on the amount added. There was a problem that the environment, health problems, etc. were caused by the outdated material. Moreover, since these plasticizers do not have reactivity with a carboxy group, the hydrolysis inhibitory effect of a carbodiimide compound may be reduced, and improvement was desired.

The technique of Patent Document 4 aims to obtain a coating film excellent in hydrolysis resistance and bending workability, but since the polyester-polycarbodiimide copolymer is the main component, the applicable uses are limited and productivity and cost are also limited. There were cases where further improvement was desired.

The present invention provides a polyester-based resin composition excellent in hydrolysis resistance and bleed-out resistance that does not cause a significant increase in melt viscosity and solution viscosity, a method for producing the polyester-based resin composition, and the polyester-based resin An object of the present invention is to provide a molded article using the composition.

MEANS TO SOLVE THE PROBLEM As a result of repeating earnest examination in order to achieve the said objective, the present inventors discovered that the said subject could be solved by mix|blending a specific carbodiimide compound in a specific ratio with respect to a polyester resin, and completed this invention.

That is, the present invention provides the following polyester-based resin composition, a method for producing the polyester-based resin composition, and a molded article using the polyester-based resin composition.

[1] A polyester-based resin composition containing a polyester-based resin (A) and a carbodiimide compound (B) represented by the following general formula (1), wherein the content of the carbodiimide compound (B) is The polyester resin composition which is 0.1-8 weight part with respect to 100 weight part of total amounts of a system resin (A) and a carbodiimide compound (B).

[Tue 1]

In the formula, R ¹ represents the 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- shall be directly bonded to the alicyclic structure of ^{R 2 .} R ³ represents a divalent residue of polyesterdiol. X is the following general formulas (2) to (4)

[Tue 2]

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

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

[3] The polyester resin composition according to the above [1] or [2], ^{wherein 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 equivalent of the carbodiimide compound (B) is 100 to 1,000.

[5] The above [1] to [4] wherein the polyester-based resin (A) is at least one selected from polyethylene terephthalate, polybutylene terephthalate, polybutylene succinate, polylactic acid, and polyhydroxyalkanoic acid. The polyester-based resin composition according to any one of ].

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

[7] The method for producing the polyester resin composition according to any one of [1] to [6], wherein the polyester resin (A) and the carbodiimide compound (B) are melt-kneaded.

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

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

According to the present invention, a polyester-based resin composition excellent in hydrolysis resistance and bleed-out resistance that does not cause a significant increase in melt viscosity and solution viscosity, a method for producing the polyester-based resin composition, and the polyester-based resin It is possible to provide a molded article using the composition.

[Polyester-based resin composition]

The polyester-based resin composition of the present invention is a polyester-based resin composition containing a polyester-based resin (A) and a carbodiimide compound (B) represented by the following general formula (1), wherein the carbodiimide compound (B) Content of is 0.1-8 weight part with respect to 100 weight part of total amounts of polyester-type resin (A) and carbodiimide compound (B), It is characterized by the above-mentioned.

[Tue 3]

In the formula, R ¹ represents the 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- shall be directly bonded to the alicyclic structure of ^{R 2 .} R ³ represents a divalent residue of polyesterdiol. X is the following general formulas (2) to (4)

[Tuesday 4]

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

Although the reason why the polyester-based resin composition of the present invention is excellent in hydrolysis resistance and bleed-out resistance and does not cause a significant increase in melt viscosity and solution viscosity is not certain, it is considered as follows.

Since the carbodiimide compound (B) represented by the general formula (1) contained in the polyester-based resin composition of the present invention has a polyester segment between polycarbodiimide groups, an appropriate distance between the polycarbodiimide groups is It is thought that the rapid increase in viscosity due to the crosslinking reaction at the time of melt-kneading was suppressed by this.

Moreover, since the carbodiimide compound (B) has a polyester segment between polycarbodiimide groups, the solubility and dispersibility of the carbodiimide compound (B) in the polyester-based resin (A) can be improved. It is thought that a molded article excellent in hydrolysis resistance and bleed-out resistance was obtained while suppressing the increase in melt viscosity and solution viscosity.

Further, it is considered that by using a polycarbodiimide having a specific alicyclic structure as the polycarbodiimide, excellent hydrolysis resistance can be exhibited even at a carbodiimide group concentration lower than that of the conventional aliphatic polycarbodiimide.

<Polyester-based resin (A)>

As the polyester-based resin (A), any resin having an ester group can be used without any particular limitation.

As such a polyester-based resin (A), for example, polyethylene terephthalate (hereinafter also referred to as "PET"), polybutylene succinate (hereinafter also referred to as "PBS"), polybutylene succinate adipate ( Hereinafter also referred to as "PBSA"), polybutylene adipate terephthalate (hereinafter also referred to as "PBAT"), polybutylene terephthalate (hereinafter also referred to as "PBT"), polyethylene naphthalate, polyarylate, ethylene At least one selected from polyhydroxyalkanoic acids (hereinafter, also referred to as “PHA”) such as terephthalate-isophthalate copolymer, polylactic acid (hereinafter also referred to as “PLA”), and polybutyric acid can be used.

Among these, from the viewpoint of economy and processability, preferably at least one selected from polyethylene terephthalate, polybutylene terephthalate, polybutylene succinate, polylactic acid, and polyhydroxyalkanoic acid, more preferably polyethylene It is terephthalate.

The content of the polyester-based resin (A) in the polyester-based resin composition of the present invention is preferably 80 to 99.9% by weight, more preferably from the viewpoint of hydrolysis resistance, melt viscosity, and solution viscosity of the polyester-based resin composition. Preferably, it is 85 to 99.8% by weight, more preferably 90 to 99.7% by weight, and still more preferably 95 to 99.5% by weight.

<Carbodiimide compound (B)>

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

[Tue 5]

In the formula, R ¹ represents the 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- shall be directly bonded to the alicyclic structure of ^{R 2 .} R ³ represents a divalent residue of polyesterdiol. X is the following general formulas (2) to (4)

[Tue 6]

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

In general formula (1), R<^1> represents the residue of the compound (henceforth "terminal blocker (a)" or "component (a)") which has one functional group which has reactivity with isocyanate.

In the carbodiimide compound (B) used in the present invention, the compatibility of the carbodiimide compound (B) with the polyester resin (A) and the poly It is thought that the storage stability of an ester-type resin composition can be improved and quality can be improved.

[End encapsulant; (a) component]

Monoalcohol, monophenol, monoisocyanate, monoamine etc. are mentioned as said (a) component.

As said monoalcohol, methanol, ethanol, cyclohexanol, polyethyleneglycol monomethyl ether, polypropylene glycol monomethyl ether, etc. are mentioned.

Phenol, methylphenol, dimethylphenol, naphthol etc. are mentioned as said monophenol.

Examples of the monoisocyanate include lower alkyl monoisocyanates such as methyl isocyanate, ethyl isocyanate, propyl isocyanate, n-, sec- or tert-butyl isocyanate; alicyclic aliphatic monoisocyanates such as cyclohexyl isocyanate; Aromatic monoisocyanate, such as phenyl isocyanate, tolyl isocyanate, dimethylphenyl isocyanate, and 2, 6- diisopropyl phenyl isocyanate, etc. are mentioned.

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

Among these, from the viewpoint of improving the compatibility of the carbodiimide compound (B) with the polyester resin (A) and storage stability of the polyester resin composition, preferably monoalcohol or monoisocyanate, more preferably mono Alcohol, more preferably polyethylene glycol monomethyl ether or polypropylene glycol monomethyl ether, still more preferably polyethylene glycol monomethyl ether.

In the general formula (1), R ² represents a divalent aliphatic group having at least one alicyclic structure. However, -N=C=N- shall be directly bonded to the alicyclic structure of ^{R 2 .}

In the carbodiimide compound (B) used in the present invention, since the carbodiimide group (-N=C=N-) is directly bonded to the alicyclic structure, the reactivity with the carboxyl group can be increased, and lower than that of the conventional aliphatic polycarbodiimide. It is thought that the outstanding hydrolysis resistance was able to be exhibited also in the carbodiimide group density|concentration.

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

[diisocyanate; (b) component]

Examples of the component (b) include cyclohexane-1,4-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, and methylcyclohexanediisocyanate. Among these, dicyclohexylmethane-4,4'-diisocyanate is preferable from the viewpoints of hydrolysis resistance, melt viscosity, and solution viscosity of the polyester resin composition.

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

Since the carbodiimide compound (B) used in the present invention has ^{a polyester segment as R 3} , the compatibility with the polyester resin (A) is good, and the carbodiimide compound ( Since the solubility and dispersibility of B) can be improved, while suppressing an increase in melt viscosity and solution viscosity, it is thought that hydrolysis resistance and bleed-out resistance were improved.

[Polyester diol; (c) component]

Although it will not restrict|limit especially as said (c) component if it is diol which has an ester group, For example, what consists of a chemical structure obtained by polycondensation of polyhydric carboxylic acid and polyhydric alcohol is mentioned.

Examples of the polyhydric carboxylic acid include aliphatic dibasic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, brassylic acid, dimer acid and hydrogenated substances thereof, 1,2-cyclohexanedicarboxylic acid, At least one selected from dibasic acids such as alicyclic dibasic acids such as 1,3-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid, and aromatic dibasic acids such as terephthalic acid, isophthalic acid, orthophthalic acid and naphthalenedicarboxylic acid It is preferable to use

Examples of the polyhydric alcohol include aliphatic glycols such as ethylene glycol, propylene glycol, butanediol, neopentyl glycol, methylpentanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, dodecanediol and dimerdiol; It is preferable to use 1 or more types chosen from glycols, such as alicyclic glycols, such as cyclohexanediol and hydrogenated xylene glycol, and aromatic ring containing glycols, such as xylene glycol.

(c) As a number average molecular weight of a component, From a viewpoint of the hydrolysis resistance of a polyester resin composition, melt viscosity, and solution viscosity, Preferably it is 1,000-40,000, More preferably, 1,500-35,000, More preferably, 2,000- 30,000. In addition, the number average molecular weight is measured using polystyrene as a standard substance by the gel chromatography method.

In general formula (1), m represents the number of 1-20 from a viewpoint of the hydrolysis resistance of a polyester resin composition, melt viscosity, and solution viscosity, Preferably it is 2-18, More preferably, 4- 16, More preferably, it is 6-15.

In general formula (1), n represents the number of 1-20 from the same viewpoint, Preferably it is 2-18, More preferably, it is 4-16, More preferably, it is 6-15.

In general formula (1), p represents the number of 1-5 from the same viewpoint, Preferably it is 1-4, More preferably, it is 1-3.

(carbodiimide equivalent)

The carbodiimide equivalent (the formula weight per 1 mol of the carbodiimide group) of the carbodiimide compound (B) is preferably 100 to 1,000 from the viewpoints of hydrolysis resistance, melt viscosity, and solution viscosity of the polyester-based resin composition. , More preferably, it is 150-850, More preferably, it is 200-600.

(Content of carbodiimide compound (B))

The content of the carbodiimide compound (B) is 100 weight of the total amount of the polyester resin (A) and the carbodiimide compound (B) from the viewpoint of hydrolysis resistance, melt viscosity, and solution viscosity of the polyester resin composition It is 0.1-8 weight part with respect to a part, Preferably it is 0.2-7 weight part, More preferably, it is 0.3-6 weight part, More preferably, it is 0.5-5 weight part.

<Method for producing carbodiimide compound (B)>

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

For example,

(i) carbodiimidization reaction of diisocyanate (b) in the presence of a catalyst to obtain polycarbodiimide (hereinafter also referred to as “component (d)”) a) and a method of adding polyesterdiol (c), copolymerizing reaction and end-blocking reaction;

(ii) a method of carbodiimidization reaction, copolymerization reaction, and terminal capping reaction of diisocyanate (b), polyesterdiol (c), and terminal blocker (a) in the presence of a catalyst;

(iii) a method in which a diisocyanate (b) and a polyesterdiol (c) are copolymerized, then a terminal blocker (a) and a catalyst are added, and a carbodiimidization reaction and a terminal block reaction are performed. can

Among these, it is preferable to manufacture according to the said method (i) from a viewpoint of productivity.

(Preparation of polycarbodiimide (d))

The polycarbodiimide (d) can be synthesized by subjecting the diisocyanate (b) to a carbodiimidization reaction in a solvent-free or inert solvent using an organophosphorus compound or an organometallic compound as a carbodiimidization catalyst. .

Specific examples of the carbodiimidization catalyst include 3-methyl-1-phenyl-2-phospholene-1-oxide, 3-methyl-1-ethyl-2-phospholene-1-oxide, and 1,3-dimethyl -2-phospholene-1-oxide, 1-phenyl-2-phospholene-1-oxide, 1-ethyl-2-phospholene-1-oxide, 1-methyl-2-phospholene-1-oxide oxides and the like. Among these, 3-methyl-1-phenyl-2-phospholene-1-oxide, which is industrially available, is preferable. A carbodiimidation catalyst may be used individually by 1 type or in combination of 2 or more type.

The reaction temperature of the carbodiimidization reaction is preferably 70 to 250°C, more preferably 100 to 230°C, still more preferably 150 to 200°C from the viewpoint of productivity.

From the same viewpoint, the reaction time of the carbodiimidization reaction is preferably 1 to 50 hours, more preferably 10 to 40 hours, still more preferably 20 to 30 hours.

The amount of the catalyst to be used can be appropriately determined depending on the type of catalyst to be used, but preferably 0.01 to 10 parts by weight, more preferably 0.05 to 5 parts by weight, further preferably based on 100 parts by weight of diisocyanate (b). 0.2 to 1 part by weight.

(copolymerization reaction)

The copolymerization reaction can be carried out by reacting the polycarbodiimide (d), the terminal blocker (a), and the polyesterdiol (c) obtained above under heating. Although there is no particular limitation on the order of adding the component (d) and the component (a) and the component (c), it is preferable to add the component (d), the component (a) and the component (c) at the same time from the viewpoint of workability at the time of synthesis. Preferably, from a viewpoint of suppressing a side reaction, it is preferable to add (d) component and (a) component, and to add (c) component after confirming completion|finish of reaction of (d) component and (a) component.

The mixing ratio of polycarbodiimide (d) and polyesterdiol (c) is the terminal isocyanate of polycarbodiimide (d) from the viewpoint of hydrolysis resistance, melt viscosity, and solution viscosity of the obtained polyester-based resin composition. The ratio [NCO(d)/OH(c)] of the number of moles of groups to the number of moles of hydroxyl groups in the polyesterdiol (c) is preferably 1.20 to 2, more preferably 1.25 to 2, still more preferably 1.33 ~2.

The reaction temperature of the copolymerization reaction is, from the viewpoint of productivity, preferably 40 to 250 °C, more preferably 90 to 220 °C, still more preferably 130 to 200 °C.

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

From the viewpoint of the productivity of the polyester resin composition, the obtained carbodiimide compound (B) is melt-mixed with the polyester resin (A) to form a master batch, or it is preferable to pelletize only the carbodiimide compound (B) component. It is more preferable to pelletize only the carbodiimide compound (B) component. Pelletization can be performed by processing into pellet shape with a well-known pelletizer.

<Other ingredients>

Additives, such as a pigment, a filler, a leveling agent, surfactant, a dispersing agent, a ultraviolet absorber, antioxidant, a flame retardant, and a coloring agent, can be mix|blended suitably with the polyester resin composition as needed.

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

The total content of the polyester-based resin (A) and the carbodiimide compound (B) in the polyester-based resin composition of the present invention is from the viewpoint of processability, hydrolysis resistance, melt viscosity, and solution viscosity of the polyester-based resin composition, Preferably it is 90-100 weight%, More preferably, it is 92-100 weight%, More preferably, it is 95-100 weight%.

[Method for Producing Polyester-Based Resin Composition]

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

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

Melt-kneading can be performed using a well-known mixer etc. provided with a heating means. Although there is no particular limitation on the order in which each material is put into the mixer, the polyester-based resin (A) serving as the base is first added and melted, and then the carbodiimide compound (B) and other components added as needed are added. It is preferable to do

The time of melt-kneading can be appropriately determined by the shape of the screw, rotational speed, etc., and is usually 1 to 30 minutes, preferably 1 to 10 minutes, and more preferably 1 to 5 minutes. Moreover, although the temperature at the time of melt-kneading changes with the kind of polyester-type resin (A) used as a base, it is about 150-350 degreeC normally, Preferably it is 200-320 degreeC, More preferably, it is 240-300 degreeC. to be.

It is preferable that the carbodiimide compound (B) used in the manufacturing method of this invention is pelletized.

Conventional polycarbodiimide additives have a low melting point, so if they are added to an extruder using a feeder or the like, they may melt at the inlet portion, making it difficult to put in. On the other hand, powdery polycarbodiimide additives are mixed with polyester resin pellets and dry When adding by blending, the carbodiimide additive segregated due to the difference in shape, resulting in concentration nonuniformity in some cases. In addition, since the polycarbodiimide additive is slightly inferior in compatibility with the polyester-based resin (A), it is difficult to uniformly disperse the polycarbodiimide additive in a low concentration in the molded article.

On the other hand, the carbodiimide compound (B) used in the present invention can be pelletized and dry blended with the polyester resin (A) to process a molded article. In particular, since the carbodiimide compound (B) having a large molecular weight has a high melting point, pelletization is facilitated. Since it is in the form of pellets, segregation does not occur easily, and since the polyester segment is present in the molecule, compatibility with the polyester resin (A) is good, and even at a low concentration, it is uniformly dispersed in the molded body of the polyester resin (A). I think I could

In addition, since it can be added directly to the polyester-based resin (A) by dry blending, it is not necessary to prepare a master batch for each type of the polyester-based resin (A), and it becomes possible to reduce the number of manufacturing steps. Together, it is thought that the deactivation (reaction of ester resin and carbodiimide) caused by thermal history due to master batch formation was avoided.

[Molded article using polyester-based resin composition]

The molded article of the present invention is a molded article molded using the polyester-based resin composition of the present invention.

In the case of obtaining a molded article from the polyester-based resin composition of the present invention, it may be molded by extrusion molding, injection molding, blow molding, etc. at the time of melt-kneading described above, once compounded in a master batch or the like, and then melt-kneaded with other materials. You may perform shaping|molding.

The polyester-based resin composition of the present invention has good workability because the melt viscosity does not increase significantly during molding in any molding method. In addition, the molded article molded from the polyester resin composition of the present invention is excellent in various performances such as strength in terms of good hydrolysis resistance.

Example

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

[Evaluation items]

(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)). , It measured at 30 degreeC using the Canon Penske viscometer. The unit is (dl/g).

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

The melt-kneaded polyester resin composition was dried at 130° C. for 4 hours, and melt mass flow rate was performed at a test temperature of 270° C. and a test load of 2.16 kgf using a melt flow indexer (VR-4100, manufactured by Ueshima Corporation), which is a melt viscosity measuring instrument. (MFR) was measured. The unit is (g/10min). The obtained MFR (g/10min) was made into the parameter|index of melt viscosity. It shows that melt viscosity is low, so that MFR value is large.

(3) Strength retention rate (hydrolysis resistance test)

The melt-kneaded polyester resin composition was flat-pressed 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.

Then, the tensile strength of the rectangular sheet produced by the tensile testing machine was measured. In addition, the produced rectangular sheet was put into a highly accelerated life tester (HAST CHAMBER EHS-210M manufactured by ESPEC) under the conditions of 121 ° C. and 100% RH, after 24 hours and after 40 hours, the sample was taken out, and tensile The tensile strength of the rectangular sheet was measured with a testing machine. The average value of the tensile strength of each 5 sheets before and after a test was computed, and the strength retention was calculated|required as an evaluation index of hydrolysis resistance by the following formula.

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

(4) Bleed-out resistance evaluation

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

Synthesis Example 1 (Synthesis of carbodiimide compound P1)

100 parts by weight of 4,4'-dicyclohexylmethane diisocyanate and 0.5 parts by weight of a carbodiimidization catalyst (3-methyl-1-phenyl-2-phospholene-1-oxide) were placed in a reaction vessel equipped with a reflux tube and a stirrer. and stirred at 185°C under a nitrogen stream for 24 hours to obtain isocyanate-terminated poly4,4'-dicyclohexylmethanecarbodiimide.

The absorption peak by the carbodiimide group around ^{wavelength 2150cm<-1>} was confirmed by infrared absorption (IR) spectrum measurement. As a result of measuring the residual isocyanate group concentration (hereinafter also referred to as "NCO%") measured by titration, it was 3.78%, and the number of repeating units of the structural unit represented by ^{(-R 2 -N = C = N-) (hereinafter, "} degree of polymerization") was 9.0.

Next, the isocyanate-terminated poly4,4'-dicyclohexylmethanecarbodiimide obtained above was heated to 150°C, and thereto, 7.9 parts by weight of polyethylene glycol monomethyl ether (molecular weight 208), and polyesterdiol (Toyo It was made to react for 2 hours, adding 57.3 weight part of "Byron 220", molecular weight 3,000 by Bosco Corporation, and heating to 180 degreeC and stirring.

It was confirmed by infrared absorption (IR) spectrum measurement that ^{absorption of the isocyanate group having a wavelength of 2200 to 2300 cm -1} disappeared, and the reaction product was taken out from the reaction vessel 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 Synthesis Example 1, carbodiimide compounds P2 to P4 were obtained in the same manner as in Synthesis Example 1 except that the raw material composition and reaction conditions were changed to the conditions shown in Table 1.

Synthesis Example 5 (Synthesis of carbodiimide compound P5)

In Synthesis Example 1, the reaction conditions and the type of terminal blocker were changed to the conditions shown in Table 1, and the same as in Synthesis Example 1 except that polyesterdiol (“Byron 220” manufactured by Toyobo Co., Ltd., molecular weight 3,000) was not added. and carbodiimide compound P5 was obtained.

Synthesis Example 6 (Synthesis of carbodiimide compound P6 in pellet form)

100 parts by weight of 4,4'-dicyclohexylmethane diisocyanate and 0.5 parts by weight of a carbodiimidization catalyst (3-methyl-1-phenyl-2-phospholene-1-oxide) to a reaction vessel equipped with a reflux tube and a stirrer and stirred at 185°C under a nitrogen stream for 28 hours to obtain isocyanate-terminated poly4,4'-dicyclohexylmethanecarbodiimide. The absorption peak by the carbodiimide group around ^{wavelength 2150cm<-1>} was confirmed by infrared absorption (IR) spectrum measurement. As a result of measuring NCO%, it was 2.92% (polymerization degree = 12.0).

Then, the isocyanate-terminated poly4,4'-dicyclohexylmethanecarbodiimide obtained above is heated to 150°C, and 6.1 parts by weight of polyethylene glycol monomethyl ether (molecular weight 208) is added thereto, heated to 180°C, and stirred. After making it react for 1 hour, the reaction product was taken out from the reaction vessel, cooled to room temperature, and pale yellow transparent isocyanate piece terminal 4,4'-dicyclohexylmethanecarbodiimide was obtained.

Next, 90.6 parts by weight of the isocyanate single terminal 4,4'-dicyclohexylmethanecarbodiimide and 44.0 parts by weight of polyesterdiol ("Byron 220" manufactured by Toyobo Corporation, molecular weight 3,000) by a twin-screw extruder (Toyosei Corporation) The pellet-form carbodiimide compound P6 was obtained by supplying to the key manufacturing company, lab plast mill), melt-kneading at 180 degreeC, and processing the obtained strand into pellet shape with a pelletizer.

In the obtained pellet-form carbodiimide compound P6, it was confirmed by infrared absorption (IR) spectrum measurement that absorption of the isocyanate group having a ^{wavelength of 2200 to 2300 cm -1 disappeared.}

Synthesis Example 7 (Synthesis of carbodiimide compound P7 in pellet form)

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

*1: HDMI, 4,4'-dicyclohexylmethane diisocyanate

*2: TMXDI, tetramethylxylylene diisocyanate

*3: 3-methyl-1-phenyl-2-phospholene-1-oxide

*4: PG1, polyethylene glycol monomethyl ether, molecular weight 208

*5: PG2, polyethylene glycol monomethyl ether, average molecular weight 400

*6: PE1, polyesterdiol, Toyobo Co., Ltd. "Byron 220", average molecular weight 3,000

*7: PC, polycarbonate diol, Asahi Kasei Chemicals Co., Ltd. "Duranol T-5650E", average molecular weight 500

*8: PE2, polyesterdiol, “XP-1233” manufactured by Unitica Co., Ltd., average molecular weight 3,900

*9: Formula weight per 1 mol of carbodiimide group

Example 1

After melting 99.00 parts by weight of PET resin (manufactured by China Petrochemical) with a laboratory mixer under the conditions of 270° C., 1.00 parts by weight of the carbodiimide compound P1 obtained in Synthesis Example 1 was added and mixed for 3 minutes to obtain a polyester resin composition got it Table 2 shows the viscosity characteristics of the obtained polyester resin composition.

Examples 2-5, Comparative Examples 1-4

A polyester-based resin composition was obtained in the same manner as in Example 1, except that the compounding composition in Example 1 was changed to the compounding composition shown in Table 2. Table 2 shows the viscosity characteristics of the obtained polyester resin composition.

*1: Polyethylene terephthalate resin (PET resin), made in China Petrochemical

*2: Carbodiimide concentration (wt%): Carbodiimide group (-N=C=N-) content in the polyester-based resin composition=[Theoretical carbodiimide group concentration in the carbodiimide compound (B) (weight) %) x addition amount (weight part)/polyester resin composition (weight part)] x 100

Examples 6-8, Comparative Examples 5-8

Hydrolysis resistance of the polyester-based resin compositions obtained in Examples and Comparative Examples and the presence or absence of bleed-out were confirmed. A result is shown in Table 3.

*1: 100 parts by weight of PET resin (made by China Petrochemical) melted at 270°C with a laboratory mixer

From Tables 2-3, the polyester-based resin composition of the present invention has no significant increase in melt viscosity and solution viscosity, despite the carbodiimide group concentration equivalent to that of Comparative Example, and has hydrolysis resistance and bleed-out resistance. It can be seen that excellent

On the other hand, the polyester-based resin composition of Comparative Example 1 containing the carbodiimide compound P4 having a polycarbonate diol residue in the carbodiimide compound had a remarkable rise in melt viscosity.

In addition, Comparative Examples 2-3 containing the carbodiimide compound P5 having no residue of a diol compound in the carbodiimide compound, and the carbodiimide compound P3 using an aliphatic diisocyanate having no alicyclic structure as the diisocyanate. The sheets obtained from Comparative Example 4 (Comparative Examples 6 to 8) were inferior in hydrolysis resistance to the sheets obtained from Examples 1 to 2 and 4 (Examples 6 to 8).

Claims (9)

A polyester-based resin composition containing a polyester-based resin (A) and a carbodiimide compound (B) represented by the following general formula (1), wherein the content of the carbodiimide compound (B) is a polyester-based resin ( A polyester resin composition which is 0.1-8 weight part with respect to 100 weight part of total amounts of A) and a carbodiimide compound (B).

(Wherein, R ¹ represents the 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 R ² It is assumed that it is directly bonded to the alicyclic structure of R ³ represents a divalent residue of polyesterdiol X represents the following general formulas (2) to (4)

represents a group selected from m represents the number of 1-20, n represents the number of 1-20, and p represents the number of 1-5. A plurality of R ² , X may be the same or different, respectively.) The method according to claim 1,
A polyester-based resin composition having a number average molecular weight of 1,000 to 40,000 of the polyester diol. The method according to claim 1 or 2,
The polyester-based resin composition wherein R ² is a divalent residue of dicyclohexylmethane-4,4'-diisocyanate. The method according to claim 1 or 2,
A polyester-based resin composition having a carbodiimide equivalent weight of 100 to 1,000 of the carbodiimide compound (B). The method according to claim 1 or 2,
The polyester-based resin (A) is at least one selected from polyethylene terephthalate, polybutylene terephthalate, polybutylene succinate, polylactic acid, and polyhydroxyalkanoic acid. The method according to claim 1 or 2,
A polyester-based resin composition wherein the compound having one functional group reactive with the isocyanate is monoalcohol, monophenol, monoisocyanate, or monoamine. The method for producing the polyester-based resin composition according to claim 1 or 2, wherein the polyester-based resin (A) and the carbodiimide compound (B) are melt-kneaded. 8. The method of claim 7,
A method for producing a polyester-based resin composition in which the carbodiimide compound (B) is pelletized. A molded article molded using the polyester-based resin composition of claim 1 or 2.