WO2020213391A1

WO2020213391A1 - Polyester resin composition

Info

Publication number: WO2020213391A1
Application number: PCT/JP2020/014846
Authority: WO
Inventors: 雄大佐々木
Original assignee: 日清紡ケミカル株式会社
Priority date: 2019-04-15
Filing date: 2020-03-31
Publication date: 2020-10-22
Also published as: JP2020176167A; JP7249197B2

Abstract

Provided is a polyester resin composition that exhibits superior hydrolytic resistance and generates little isocyanate gas when heated during melt kneading and molding. The polyester resin composition contains a polyester resin (A) and a carbodiimide compound (B) having a specific structure, wherein the carbodiimide compound (B) content is 0.1-10 parts by mass relative to a total of 100 parts by mass of the polyester resin (A) and the carbodiimide compound (B).

Description

Polyester resin composition

The present invention relates to a polyester resin composition.

Polyester resin is widely used for films, sheets, etc. because it has excellent transparency, mechanical strength, melt stability, solvent resistance, and recyclability. In recent years, it has been used as a housing for home appliances and OA equipment. It is also used on the body.
However, since polyester resins have the property of being easily hydrolyzed as compared with conventional general-purpose resins, a method of adding a carbodiimide compound has been studied for the purpose of improving hydrolysis resistance. There is.

By blending a carbodiimide compound with a polyester resin and molding it, the carboxy group in the polyester resin and the carboxy group generated by the decomposition of the ester group when kneading at a high temperature react with the blended carbodiimide compound to mold it. It is possible to suppress a decrease in the initial performance (for example, mechanical strength) of an object. In addition, the durability of the molded product is improved by leaving the carbodiimide compound in the molded product.

As such a hydrolysis resistant stabilizer for polyester resins, those containing, for example, a specific aliphatic or aromatic carbodiimide compound as a main component are known (Patent Documents 1 and 2).
However, although the polyester resin composition to which such a specific aliphatic or aromatic carbodiimide compound is added has improved hydrolysis resistance, the carbodiimide compound is decomposed by heating during melt kneading and molding, and the isocyanate gas is decomposed. There was a problem that the work environment was deteriorated.

Japanese Unexamined Patent Publication No. 9-249801 Japanese Unexamined Patent Publication No. 2015-147838

Therefore, an object of the present invention is to provide a polyester resin composition having excellent hydrolysis resistance and less generation of isocyanate gas due to heating during melt kneading and molding.

As a result of diligent studies, the present inventors have contained a polyester resin (A) and a specific carbodiimide compound (B), and the content of the carbodiimide compound (B) is the polyester resin (A) and the carbodiimide. Since the total amount of the compound (B) is 0.1 to 10 parts by mass with respect to 100 parts by mass, the polyester type has excellent hydrolysis resistance and generates less isocyanate gas due to heating during melt kneading and molding. They have found that a resin composition can be obtained, and have completed the present invention.

That is, the gist structure of the present invention is as follows.
[1] A polyester resin composition containing a polyester resin (A) and a carbodiimide compound (B) represented by the following general formula (1).
A polyester resin composition in which the content of the carbodiimide compound (B) is 0.1 to 10 parts by mass with respect to 100 parts by mass of the total amount of the polyester resin (A) and the carbodiimide compound (B). ..

(In the general formula (1), R ¹ and R ⁴ represent residues excluding the functional group of an organic compound having one functional group capable of reacting with an isocyanate group, and R ¹ and R ⁴ are the same but different. R ² represents a divalent residue obtained by removing two isocyanate groups from the diisocyanate compound, and the diisocyanate compound has a benzene-based aromatic ring that is directly bonded to the isocyanate group, and the benzene-based aromatic ring is used. The structure has no substituent or only one substituent at both ortho positions of the ring at the position where it is bonded to the isocyanate group. R ³ is a divalent residue obtained by removing two hydroxyl groups from the diol compound. Representing a group. X ¹ and X ² represent a group formed by the reaction of the functional group of the organic compound with the isocyanate group of the diisocyanate compound, and X ¹ and X ² may be the same or different. n and m represent numbers from 1 to 20.)
[2] The polyester-based resin composition according to the above [1], wherein the diisocyanate compound contains at least one selected from toluene diisocyanate, trizine diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate and paraphenylenedi isocyanate.
[3] The diisocyanate compound contains a mixture of 2,4'-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate.
When the total amount of the diisocyanate compound is 100 mol%, the ratio of the 2,4'-diphenylmethane diisocyanate is 30 to 70 mol%, and the ratio of the 4,4'-diphenylmethane diisocyanate is 30 to 70 mol%. The polyester-based resin composition according to the above [2].
[4] When the total amount of the diisocyanate compound is 100 mol%, the ratio of the 2,4'-diphenylmethane diisocyanate is 50 to 60 mol%, and the ratio of the 4,4'-diphenylmethane diisocyanate is 40 to 50. The polyester-based resin composition according to the above [3], which is mol%.
[5] The above-mentioned [1] to [5], wherein the organic compound having one functional group capable of reacting with the isocyanate group is one or more selected from monoisocyanate, monoalcohol, monoamine, monocarboxylic acid and acid anhydride. The polyester-based resin composition according to any one of 4].
[6] The polyester-based resin composition according to any one of the above [1] to [5], wherein the diol compound is one or more selected from a polyether polyol, a polyester polyol, a polycarbonate polyol, and an alkane diol. object.
[7] The above-mentioned [1] to [6], wherein the polyester 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 the items.

According to the present invention, it is possible to provide a polyester-based resin composition having excellent hydrolysis resistance and less generation of isocyanate gas due to heating during melt-kneading and molding.

An embodiment of the polyester resin composition according to the present invention will be described in detail below.

The polyester-based resin composition of the present invention contains a polyester-based resin (A) and a carbodiimide compound (B) represented by the following general formula (1), and the content of the carbodiimide compound (B) is polyester-based. The total amount of the resin (A) and the carbodiimide compound (B) is 0.1 to 10 parts by mass with respect to 100 parts by mass.

In the above general formula (1), R ¹ and R ⁴ represent residues excluding the functional group of an organic compound having one functional group capable of reacting with an isocyanate group, and R ¹ and R ⁴ are the same but different. You may. R ² represents a divalent residue obtained by removing two isocyanate groups from the diisocyanate compound, and the diisocyanate compound has a benzene-based aromatic ring directly bonded to the isocyanate group, and the isocyanate of the benzene-based aromatic ring. The structure has no substituent or has only one substituent at both ortho positions at the position where it is bonded to the group. R ³ represents a divalent residue obtained by removing two hydroxyl groups from the diol compound. X ¹ and X ² represent groups formed by the reaction of the functional group of the organic compound with the isocyanate group of the diisocyanate compound, and X ¹ and X ² may be the same or different. n and m represent numbers from 1 to 20.

Such a polyester-based resin composition has excellent hydrolysis resistance, and generates less isocyanate gas due to heating during melt-kneading and molding. The reason is not clear, but it can be considered as follows.
The polyester-based resin composition of the present invention has higher reactivity than the conventional aliphatic carbodiimide by using the carbodiimide compound (B) which is a specific aromatic carbodiimide, and has excellent hydrolysis resistance even at a low carbodiimide group concentration. It is thought that it can exert.
In particular, the carbodiimide compound (B) has a benzene-based aromatic ring that directly bonds with an isocyanate group, and does not have a substituent at both ortho positions at positions that bond with the isocyanate group of the benzene-based aromatic ring, or 1 because having a divalent residue R ² derived from a diisocyanate compound having only one substituent, be a carbodiimide compound (B) is decomposed in the heating process at the time of melt kneading and molding, degradation resulting reaction of the isocyanate It is considered that the isocyanate gas is easily taken into the polyester resin (A) and is not easily released into the environment as an isocyanate gas.

Hereinafter, the polyester-based resin composition of the present invention will be described in detail for each component.

<Polyester resin (A)>
As the polyester resin (A), any resin having an ester group can be used without particular limitation.
The polyester resin (A) can be obtained, for example, by a polycondensation reaction of a dibasic acid or an acid anhydride thereof or a dibasic acid ester with a dihydric alcohol, a polycondensation reaction of a hydroxycarboxylic acid or a cyclic derivative thereof, or ring-opening polymerization. It is a resin having an ester bond in the main chain.

Examples of the dibasic acid or its acid anhydride include phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, succinic anhydride, adipic acid, azelaic acid, sebacic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and the like. Examples thereof include tetrabrom phthalic anhydride, tetrachlorophthalic anhydride, hetic anhydride, endomethylenetetrahydrophthalic anhydride, maleic anhydride, fumaric acid and itaconic acid.
Examples of the dibasic acid ester include dimethyl terephthalate and dimethyl naphthalenedicarboxylic acid.

Examples of the dihydric alcohol include ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, and triethylene glycol. Examples thereof include hydride bisphenol A, bisphenol A2-hydroxypropyl ether, cyclohexanedimethanol and the like.
In addition, polyalkylene oxide glycols such as polyethylene oxide glycol, polypropylene oxide glycol, polytetramethylene oxide glycol, and polyhexamethylene oxide glycol, which are aliphatic polyethers having OH groups at both ends, can also be used.

Examples of the hydroxycarboxylic acid include lactic acid and hydroxybutyric acid.
Examples of the cyclic derivative of hydroxycarboxylic acid include lactide and lactone, examples of lactide include cyclic dimer of lactic acid, and examples of lactone include β-propiolactone and δ-valerolactone. Can be mentioned.

Specific examples of the polyester resin (A) include polyethylene terephthalate (hereinafter, also referred to as “PET”), polybutylene terephthalate (hereinafter, also referred to as “PBT”), and 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"), polyethylene naphthalate, polyarylate, ethylene terephthalate-isophthalate copolymer, polylactic acid. (Hereinafter, also referred to as "PLA"), and one or more selected from polyhydroxyalkanoic acids such as polyhydroxybutyric acid can be used.
Among these, one or more selected from polyethylene terephthalate, polybutylene terephthalate, polybutylene succinate, polylactic acid, and polyhydroxyalkanoic acid, more preferably polyethylene terephthalate and polybutylene, from the viewpoint of economy and processability. One or more selected from terephthalate.

The polyester-based resin composition of the present invention contains a polyester-based resin (A) and a carbodiimide compound (B), and the carbodiimide compound (B) has a specific structure, so that the polyester-based resin (A) can be used. The affinity is improved and it can be more uniformly dispersed in the polyester resin (A). As a result, it is possible to prevent the polyester resin (A) from locally cross-linking in the composition.

The content of the polyester resin (A) in the polyester resin composition of the present invention is preferably 80 to 99.9% by mass, more preferably 85 to 99.8% by mass, and further preferably 90 to 99.7% by mass. It is by mass, more preferably 95 to 99.5% by mass.

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

(R ¹ , R ⁴ )
In the above general formula (1), R ¹ and R ⁴ represent residues excluding the functional group of an organic compound having one functional group capable of reacting with an isocyanate group, and R ¹ and R ⁴ are the same but different. You may.

The organic compound having one functional group capable of reacting with the isocyanate group (hereinafter, also simply referred to as “organic compound”) is not particularly limited as long as it has one functional group capable of reacting with the isocyanate group, but is reactive. From the viewpoint of the above, it is preferable that the mixture is one or more selected from monoisocyanate, monoalcohol, monoamine, monocarboxylic acid and acid anhydride.

Above all, monoisocyanate is preferable in that the content ratio of the carbodiimide group in the carbodiimide compound (B) can be increased.
Examples of the monoisocyanate include lower alkyl isocyanates such as methyl isocyanate, ethyl isocyanate, propyl isocyanate, n-, sec- or ter-butyl isocyanate; alicyclic isocyanates such as cyclohexyl isocyanate; phenyl isocyanate, tolyl isocyanate and dimethylphenyl isocyanate. , 2,6-Diisopropylphenylisocyanate and other aromatic isocyanates. Of these, phenylisocyanate and tolylisocyanate are preferable, and phenylisocyanate is more preferable, from the viewpoint of reactivity. On the other hand, phenylisocyanate is particularly reactive and tends to be carbodiimided by itself to become monocarbodiimide. Therefore, from the viewpoint of suppressing the formation of monocarbodiimide, monoisocyanate excluding phenylisocyanate is preferable.

Further, the monoalcohol has high reactivity with the isocyanate group, which makes it easy to synthesize the carbodiimide compound (B), and can effectively suppress the generation of isocyanate gas when the carbodiimide compound (B) is decomposed. Preferred in terms of points.
Examples of monoalcohols include aliphatic alcohols, alicyclic alcohols, and polyether monools. Examples of such monoalcohols include methanol, ethanol, isopropyl alcohol, cyclohexanol, 2-ethylhexanol, octanol, dodecyl alcohol, polyethylene glycol monomethyl ether, polypropylene glycol monomethyl ether and the like. Among them, isopropyl alcohol, 2-ethylhexanol, octanol and dodecyl alcohol are preferable, and isopropyl alcohol is preferable from the viewpoint of excellent handleability of the obtained carbodiimide compound (B) and good processability with the polyester resin (A). Is more preferable.

Further, monoamine is preferable in that it has high reactivity with an isocyanate group, facilitates the synthesis of a carbodiimide compound (B), and has excellent compatibility with a polyester resin (A).
Examples of monoamines include primary and secondary alkylamines. Examples of such monoamines include primary amines such as butylamine and cyclohexylamine; and secondary amines such as diethylamine, dibutylamine and dicyclohexylamine. Of these, butylamine and cyclohexylamine are preferable from the viewpoint of improving processability with the polyester resin (A).

Further, the monocarboxylic acid and the acid anhydride have excellent heat resistance of the bond sites (X ¹ , X ² in the above general formula (1)) generated by the reaction with the isocyanate group, and the carbodiimide compound (B). It is preferable in that it can effectively suppress the generation of isocyanate gas when it is decomposed.
Examples of monocarboxylic acids include formic acid, acetic acid, propionic acid, isovaleric acid, hexanoic acid, octanoic acid, lauric acid, myrstinic acid, palmitic acid, stearic acid, araquinic acid, oleic acid, linoleic acid, linolenic acid, and benzoic acid. Examples include acid. Of these, acetic acid, propionic acid and octanoic acid are preferable from the viewpoint of improving processability with the polyester resin (A).
Examples of the acid anhydride include phthalic anhydride, acetic anhydride, succinic anhydride, maleic anhydride, benzoic anhydride and the like. Of these, phthalic anhydride, acetic anhydride and succinic anhydride are preferable from the viewpoint of improving processability with the polyester resin (A).

(R ² )
In the general formula (1), R ² represents a divalent residue obtained by removing two isocyanate groups from the diisocyanate compound, and the diisocyanate compound has a benzene-based aromatic ring that is directly bonded to the isocyanate group. The structure has no substituent or only one substituent at both ortho positions of the benzene-based aromatic ring at the position where it is bonded to the isocyanate group. The diisocyanate compound has one or more benzene-based aromatic rings, and the two isocyanate groups are directly bonded to the same or different benzene-based aromatic rings, respectively. The benzene-based aromatic ring to which each isocyanate group is bonded does not have a substituent at both the ortho positions with respect to the bonding position of the isocyanate group. That is, the benzene-based aromatic ring to which each isocyanate group is bonded has a substituent at only one of the ortho positions with respect to the bonding position of the isocyanate group, or both have no substituent.

In such a carbodiimide compound (B) having R ² , the carbodiimide group (-N = C = N-) is directly bonded to the benzene-based aromatic ring, so that the carbodiimide compound (B) has high reactivity with the carboxy group and is conventionally used. It is considered that even if the carbodiimide group concentration is lower than that of the aliphatic polycarbodiimide, excellent hydrolysis resistance can be exhibited with respect to the polyester resin (A).

Further, the carbodiimide compound (B) used in the present invention has a benzene-based aromatic ring that is directly bonded to an isocyanate group, and a substituent is placed at both ortho positions of the benzene-based aromatic ring at a position where it is bonded to the isocyanate group. because it has a divalent residue R ² derived from a diisocyanate compound having no or only one substituent have, as the carbodiimide compound (B) is decomposed by heat during melt kneading and molding, The isocyanate produced is highly reactive and can be effectively suppressed from being released as a gas to the outside of the composition.

In particular, the isocyanate produced by the decomposition of the carbodiimide compound (B) having the predetermined R ² has a conventional carbodiimide compound (for example, a benzene-based aromatic ring directly bonded to an isocyanate group, and the benzene-based aromatic ring. A polyester resin because it is more reactive than isocyanates produced by decomposition of diisocyanate compounds (carbodiimide compounds with divalent residues derived from diisocyanate compounds that have substituents at both ortho positions at the positions where they bond with isocyanate groups). It is presumed that it easily reacts with the components in (A) and is easily incorporated into the resin.
Further, particularly in the case of the carbodiimide compound (B) having a relatively large molecular weight in the R ² portion, the molecular weight of the isocyanate produced by decomposition is also relatively large, so that the polyester resin (A) has a higher molecular weight than the low molecular weight compound. It is presumed that it will be more likely to remain.

The diisocyanate compound has a benzene-based aromatic ring that is directly bonded to the isocyanate group, and has no substituent or only one substituent at both ortho positions of the position where the benzene-based aromatic ring is bonded to the isocyanate group. As long as it has a structure, it is not particularly limited, and for example, tolylene diisocyanate (also referred to as toluene diisocyanate; may be abbreviated as “TDI” below), trizine diisocyanate (also referred to as dimethylbiphenyl diisocyanate, hereinafter. "TODI" may be abbreviated), diphenylmethane diisocyanate (hereinafter may be abbreviated as "MDI"), naphthalenediocyanate (hereinafter may be abbreviated as "NDI") and paraphenylenediocyanate (1, 4-Also also referred to as phenylenediisocyanate) and the like.

Here, toluene diisocyanate has two types of isomers, 2,4-TDI and 2,6-TDI. As such a toluene diisocyanate, a mixture of 2,4-TDI and 2,6-TDI is preferable, and specifically 2,4-TDI (80 mol%) and 2,6-TDI (20 mol%). Mixtures of are common.

In addition, diphenylmethane diisocyanate has three types of isomers, 2,2'-MDI, 2,4'-MDI and 4,4'-MDI. As such diphenylmethane diisocyanate, a simple substance of 4,4'-MDI or a mixture of 2,4'-MDI and 4,4'-MDI is preferable. Above all, a mixture of 2,4'-MDI and 4,4'-MDI is more preferable from the viewpoint of suppressing an increase in the melt viscosity of the carbodiimide compound (B) produced. As such a mixture of 2,4'-MDI and 4,4'-MDI, the ratio of 2,4'-MDI is preferably 30 to 70 mol%, and 40 to 65 mol% is preferable. More preferably, it is 50-60 mol%, where the proportion of 4,4'-MDI is the balance of the total mixture (100 mol%) minus the proportion of 2,4'-MDI.

The trizine diisocyanate is generally 3,3'-dimethylbiphenyl-4,4'-diisocyanate.
The naphthalene diisocyanate is generally 1,5-naphthalene diisocyanate.

The diisocyanate compound preferably contains at least one selected from tolylene diisocyanis, trizine diisocyanis, diphenylmethane diisocyanate, naphthalenediocyanis and paraphenylenediisocyanus from the viewpoint of hydrolysis resistance and effective suppression of isocyanate gas generation. More preferably, it contains at least one selected from trizine diisocyanate, diphenylmethane diisocyanate, naphthalenediocyanis and paraphenylenediisocyanate, more preferably diphenylmethane diisocyanate, and a mixture of 2,4'-MDI and 4,4'-MDI. It is even more preferable to include it.

Further, when the diisocyanate compound contains at least one selected from the group consisting of toluene diisocyanate, trizine diisocyanate, diphenylmethane diisocyanate, naphthalenediocyanisocyanate and paraphenylenediisocyanate, 1 is selected from the above group in the whole diisocyanate compound. The ratio (total) of the compounds of the species or more is preferably 80 mol% or more, more preferably 90 mol% or more, further preferably 95 mol% or more, and it is selected from the above group1 It may consist only of compounds of more than one species. Further, from the viewpoint of ease of production control and reduction of production cost, the diisocyanate compound is preferably one selected from the above group.

Further, when the diisocyanate compound contains a mixture of 2,4'-MDI and 4,4'-MDI, the ratio of 2,4'-MDI is 30 to 30 to 100 mol% as a whole of the diisocyanate compound. It is preferably 70 mol%, and the ratio of 4,4'-MDI is preferably 30 to 70 mol%. When the ratio of 2,4'-MDI is 30 mol% or more, the carbodiimide compound (B) is less likely to gel, and storage stability and solubility in a solvent can be improved. Further, by setting the ratio of 2,4'-MDI to 70 mol% or less, the steric hindrance does not become too large, the reactivity of the carbodiimide compound (B) becomes good, and when used together with the polyester resin (A), It becomes easy to obtain the desired performance. From this point of view, the ratio of 2,4'-MDI in the diisocyanate compound is more preferably 40 to 65 mol%, further preferably 50 to 60 mol%, and 4,4'-MDI. The ratio of is more preferably 35 to 60 mol%, still more preferably 40 to 50 mol%.

Further, from the viewpoint of preventing the formation of monocarbodiimide during the synthesis of the carbodiimide compound (B), when the diisocyanate compound is tolylene diisocyanate, the organic compound is monoisocyanate, monoalcohol, monoamine, excluding phenylisocyanate. It is preferably one or more selected from monocarboxylic acids and acid anhydrides.
When the diisocyanate compound is tolylene diisocyanate and the organic compound is phenyl isocyanate, n is preferably a number of 4 to 20.

When the diisocyanate compound contains two or more kinds of diisocyanate compounds, R ² is represented by two or more kinds of residues.

(R ³ )
In the above general formula (1), R ³ represents a divalent residue obtained by removing two hydroxyl groups from the diol compound. In the present specification, the diol compound means a compound having two hydroxyl groups in the molecule.

Since the carbodiimide compound (B) used in the present invention has the residue of the diol compound and the urethane bond adjacent to the carbodiimide group, it is familiar with the polyester resin (A) and more uniformly the polyester resin (A). It is thought that it can be dispersed inside. Therefore, it is considered that the increase in viscosity can be suppressed without causing a local cross-linking reaction in the composition during melt-kneading.

Examples of the diol compound include a high molecular compound having two hydroxyl groups in the molecule and a low molecular compound.
Examples of the polymer compound having two hydroxyl groups in the molecule include polyether polyol (polyalkylene oxide glycol), polyester polyol, polycarbonate polyol, silicone diol, polyolefin polyol, polyurethane polyol, alkane (21 to carbon atoms) diol and the like. Can be mentioned. Among these, from the viewpoint of the melt viscosity and the solution viscosity of the polyester resin composition, one or more selected from preferably a polyether polyol, a polyester polyol, a polycarbonate polyol, and an alcan diol, more preferably a polyether polyol, a polyester. One or more selected from polyols and polycarbonate polyols. Further, from the viewpoint of hydrolysis resistance of the polyester resin composition, a polyether polyol and a polycarbonate polyol are preferable, and a polyether polyol is particularly preferable.

Examples of the low molecular weight compound having two hydroxyl groups in the molecule include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, and 2-methyl-. Alcan diols such as 1,3-propanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, and alkane (7 to 20 carbon atoms) diol; Diols having alicyclic aliphatic groups such as cyclohexanediol, cyclohexanedimethanol, hydride bisphenol A, alkendiols such as 1,4-dihydroxy-2-butene; bishydroxyethoxybenzene, xylene glycol, bis (2-hydroxy) Examples thereof include diols having an aromatic ring such as ethyl) terephthalic acid. Among these, from the viewpoint of the melt viscosity and the solution viscosity of the polyester resin composition, an alkane diol or a diol having an aromatic ring is preferable, an alkane diol is more preferable, and ethylene glycol is more preferable.

The above diol compound may be used alone or in combination of two or more. In particular, from the viewpoint of improving hydrolysis resistance and preferably adjusting the melt viscosity during melt-kneading, it is preferable to use a combination of a low molecular weight diol compound and a high molecular weight diol compound.
The number average molecular weight of the diol compound is preferably 100 to 40,000, more preferably 150 to 10,000, from the viewpoint of hydrolysis resistance, melt viscosity, and solution viscosity of the polyester resin composition. More preferably, it is 200 to 1,000. The number average molecular weight is measured by a gel chromatography method using polystyrene as a standard substance. However, this does not apply to low molecular weight compounds.

(X ¹ , X ² )
In the general formula (1), X ¹ and X ² represent groups formed by the reaction of a functional group capable of reacting with the isocyanate group of the organic compound and the isocyanate group of the diisocyanate compound, and X ¹ and X ² are represented. May be the same or different. For example, when the organic compound is monoisocyanate, X ¹ and X ² are groups represented by the following formula (I), and when the organic compound is mono alcohol, X ¹ and X ² are the following formula (II). When the organic compound is a monoamine, X ¹ and X ² are groups represented by the following formula (III), and when the organic compound is a monocarboxylic acid, X ¹ , X ² Is a group represented by the following formula (IV), and when the organic compound is an acid anhydride, X ¹ and X ² are groups represented by the following formula (V).

(N, m)
In the above general formula (1), n and m represent numbers from 1 to 20.
In particular, in the above general formula (1), n is preferably 1 to 15, more preferably 2 to 10, from the viewpoint of hydrolysis resistance of the polyester resin composition, suppression of increase in melt viscosity, and suppression of isocyanate gas generation. is there. When the diisocyanate compound is tolylene diisocyanate and the organic compound is phenyl isocyanate, n is particularly preferably a number of 4 to 20.
Further, in the above general formula (1), m is preferably 1 to 15, more preferably 1 to 10, and further preferably 1 to 1 from the viewpoint of hydrolysis resistance of the polyester resin composition and suppression of increase in melt viscosity. 3, even more preferably 1.
In the general formula (1), the relationship between n and m is preferably n ≧ m, more preferably n> m, from the viewpoint of hydrolysis resistance of the polyester resin composition.

In the general formula (1), the structural unit (N): "-N = C = N-R ^2- " and the structural unit (M) "-NH-CO-OR ^3- O-CO" When there are a plurality of "-NH-R ^2- ", the method of connecting each structural unit may be a block connection or a random connection.
That is, in the general formula (1), n and m only indicate the number of the structural units (N) and the structural units (M) contained in the carbodiimide compound (B), and the general formula (1) ) Is not limited to the carbodiimide compound in which the structural unit (N) and the structural unit (M) are block-bonded.

(Carbodiimide equivalent)
The carbodiimide equivalent (chemical formula amount per 1 mol of carbodiimide group) of the carbodiimide compound (B) is preferably 200 to 1,500, more preferably 200 to 1,500 from the viewpoint of hydrolysis resistance of the polyester resin composition and suppression of isocyanate gas generation. It is 200 to 1,250, more preferably 200 to 1,000, and even more preferably 200 to 700.

(Content of carbodiimide compound (B))
The content of the carbodiimide compound (B) is 100 parts by mass in total of the polyester resin (A) and the carbodiimide compound (B) from the viewpoint of hydrolysis resistance of the polyester resin composition and suppression of isocyanate gas generation. On the other hand, it is 0.1 to 10 parts by mass, preferably 0.2 to 7 parts by mass, and more preferably 0.3 to 5 parts by mass.

(Method for producing carbodiimide compound (B))
The carbodiimide compound (B) of the present invention can be produced by a known method.
For example
(I) The diisocyanate compound (a) and the diol compound (b) are reacted to produce a compound of both-terminal isocyanates containing a urethane bond (hereinafter, also referred to as “component (d)”), and then the component (a) is produced. , (D), carbodiimidization and terminal encapsulation in the presence of terminal encapsulant (c) and catalyst,
(Ii) The diisocyanate compound (a) is carbodiimided in the presence of a catalyst to obtain a polycarbodiimide (hereinafter, also referred to as “component (e)”), and then the component (e) is added to the diol compound (b) and the terminal. A method of adding a sealing agent (c) to carry out a copolymerization reaction and a terminal sealing reaction,
(Iii) Examples thereof include a method in which a diisocyanate compound (a), a diol compound (b), and an end-capping agent (c) are simultaneously subjected to a urethanization reaction, a carbodiimideization reaction, and an end-sealing reaction in the presence of a catalyst. ..
Among these, from the viewpoint of productivity, it is preferable to produce by the method (i) above.
Specifically, the diisocyanate compound (a) and the diol compound (b) are mixed with the hydroxyl group of the diol compound (b) so that the isocyanate group of the diisocyanate is excessive, and a urethanization reaction is carried out. Next, it is preferable to add the terminal sealant (c) and an organic phosphorus compound or an organic metal compound as a carbodiimidization catalyst to carry out the carbodiimidization reaction in a solvent-free or inert solvent.

Here, specific examples of the diisocyanate compound (a) and the diol compound (b) are as described above. The diisocyanate compound and the diol compound may be used alone or in combination of two or more.
Further, the terminal encapsulant (c) is an organic compound having one functional group capable of reacting with the above-mentioned isocyanate group, and specific examples are as described above. The organic compound may be used alone or in combination of two or more. Further, the blending amount of the organic compound may be appropriately adjusted so that n and m in the general formula (1) are within the above range.

Examples of the catalyst used in the carbodiimidization reaction 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 and 3-methyl-2-phospholene-1-oxide 1-methyl-2- Phosphorene-1-oxide and the like can be mentioned, and among these, 3-methyl-1-phenyl-2-phospholene-1-oxide, which has good reactivity and is easily available industrially, is preferable. These may be used alone or in combination of two or more.

The amount of the catalyst used can be appropriately determined depending on the type of catalyst used, but is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5.0 parts by mass with respect to 100 mass by mass of the diisocyanate compound (a). It is by mass, more preferably 0.1 to 3.0 parts by mass.

The above carbodiimideization reaction can be carried out without a solvent or in a solvent. Solvents that can be used include alicyclic ethers such as tetrahydrofuran, 1,3-dioxane, and dioxolane: benzene, toluene, xylene, and aromatic hydrocarbons such as ethylbenzene: chlorobenzene, dichlorobenzene, trichlorobenzene, percrene, trichloroethane, etc. And halogenated hydrocarbons such as dichloroethane, cyclohexanone and the like. These may be used alone or in combination of two or more.

Further, the conditions for the urethanization reaction between the component (a) and the component (b) are not particularly limited and can be appropriately determined according to the raw materials used and the like. For example, the reaction temperature is preferably 30 to 200 ° C., more preferably 35 to 120 ° C., and even more preferably 40 to 80 ° C. from the viewpoint of productivity.

The conditions for the carbodiimidization reaction are not particularly limited and can be appropriately determined according to the raw materials used and the like. For example, the reaction temperature is preferably 40 to 250 ° C., more preferably 60 to 200 ° C., still more preferably 80 to 150 ° C. when the reaction is carried out in a solvent, from the viewpoint of productivity when no solvent is used. Is preferably 40 ° C. or higher and lower than the boiling point of the solvent. Further, the reaction time is preferably 10 minutes to 20 hours, more preferably 1 hour to 10 hours, still more preferably 2 hours to 4 hours from the viewpoint of productivity.

<Other ingredients>
Additives such as pigments, fillers, leveling agents, surfactants, dispersants, ultraviolet absorbers, antioxidants, flame retardants, and colorants should be appropriately added to the polyester resin composition, if necessary. Can be done.

<Total content of polyester resin (A) and carbodiimide compound (B)>
The total content of the polyester resin (A) and the carbodiimide compound (B) in the polyester resin composition of the present invention includes hydrolysis resistance, mechanical properties, suppression of melt viscosity increase, processability, and processability of the polyester resin composition. From the viewpoint of suppressing the generation of isocyanate gas, it is preferably 90 to 100% by mass, more preferably 92 to 100% by mass, and further preferably 95 to 100% by mass.

<Manufacturing method of polyester resin composition>
The polyester-based resin composition of the present invention can be produced, for example, by blending a carbodiimide compound (B) with a polyester-based resin (A) and other components added as necessary, and melt-kneading the mixture. it can. By using the carbodiimide compound (B) in such a polyester-based resin composition of the present invention, isocyanate gas is less likely to be generated even during melt-kneading, so that the working environment is not deteriorated. Further, by using the carbodiimide compound (B), a significant increase in melt viscosity can be suppressed, and workability during melt-kneading can be improved, so that the productivity of the polyester-based resin composition is excellent. it is conceivable that.

Melt kneading can be performed with a mixer equipped with heating means. The order in which each material is charged into the mixer is not particularly limited, but it is preferable that the base polyester resin is first charged and melted, and then the carbodiimide compound and, if necessary, additives are added.

The melt-kneading time can be appropriately determined depending on the shape of the screw, the rotation speed, etc., and is usually about 1 to 30 minutes. The temperature during melt-kneading varies depending on the type of the base polyester resin, but is usually about 150 to 350 ° C.

According to the polyester-based resin composition of the present invention, a high-quality molded product can be obtained without deteriorating the working environment in the manufacturing process.

When a molded product is obtained from the polyester-based resin composition of the present invention, it may be molded by extrusion molding, injection molding, blow molding or the like during the above-mentioned melt-kneading, or it may be first compounded into a masterbatch or the like and then other. You may perform molding by melt-kneading with the material of.

The polyester-based resin composition of the present invention can effectively suppress the generation of isocyanate gas during heat molding in any molding method, does not deteriorate the working environment, and significantly increases the melt viscosity during molding. Workability is good because there is no need to do so. In addition, the molded product molded from the polyester-based resin composition of the present invention has good hydrolysis resistance, and is therefore excellent in various performances such as strength.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, but includes all aspects included in the concept of the present invention and claims, and varies within the scope of the present invention. Can be modified to.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

Hereinafter, various materials used in Synthesis Examples, Examples and Comparative Examples are shown.
<Diisocyanate compound>
A mixture of 54% by mass of 2,4'-diphenylmethane diisocyanate and 46% by mass of 4,4'-diphenylmethane diisocyanate (mixture of 2,4'-MDI (54%) and 4,4'-MDI (46%)): Product name "Monomeric MDI; Millionate NM" manufactured by Tosoh Corporation
-4,5'-Diphenylmethane diisocyanate (4,5'-MDI): Tosoh Corporation, product name "Millionate MT"
-Mixture of 2,4-toluene diisocyanate 80% by mass and 2,6-toluene diisocyanate 20% by mass (mixture of 2,4-TDI (80%) and 2,6-TDI (20%)): Mitsui Chemicals Product name "Cosmonate T-80" manufactured by SKC Polyurethane Co., Ltd.
・ 4,4'-Dicyclohexylmethane diisocyanate (HMDI): manufactured by Sumika Covestro Urethane Co., Ltd., product name "Death Module W"
-2,4,6-triisopropylphenyl-1,3-diisocyanate: manufactured by Synthesia, product name "TRIDI"

<Diol compound>
-Polycarbonate polyol 1: Made by Ube Industries, Ltd., product name "Etanacol UH-50", molecular weight 504
-Polycarbonate polyol 2: manufactured by Asahi Kasei Chemicals Co., Ltd., product name "Duranol T-5650E", molecular weight 523
-Polyester polyol 1: Kawasaki Kasei Chemicals Co., Ltd., product name "Maximol RFK-505", molecular weight 442
-Polyester polyol 2: manufactured by Kawasaki Kasei Chemicals Co., Ltd., product name "Maximol RFK-509", molecular weight 573
-Polyester polyol 3: Kuraray Co., Ltd., product name "Kuraray polyol P-1020", molecular weight 1000
-Polyester polyol 4: Kuraray Co., Ltd., product name "Kuraray polyol P-520", molecular weight 500
-Polyether polyol 1: Made by NOF CORPORATION, product name "Uniol PB-500", molecular weight 500
-Polyether polyol 2: Sanyo Chemical Industries, Ltd., product name "Sannicks PP-400", molecular weight 405

<Terminal sealant>
・ Phenyl isocyanate: manufactured by Rankses Co., Ltd. ・ Isopropyl alcohol: manufactured by Kanto Chemical Co., Inc. ・ 1-octanol: manufactured by Tokyo Chemical Industry Co., Ltd. ・ Dodecyl alcohol: manufactured by Kanto Chemical Co., Inc. ・ Cyclohexylamine: manufactured by Tokyo Chemical Industry Co., Ltd. : Made by Tokyo Chemical Industry Co., Ltd. ・ Phtalic anhydride: Made by Tokyo Chemical Industry Co., Ltd. <Carbodiimidization catalyst>
-3-Methyl-1-phenyl-2-phospholene-1-oxide: manufactured by Shikoku Chemicals Corporation, product name "MPO"

<Polyester resin (A)>
-Polybutylene terephthalate (PBT) resin: manufactured by Mitsubishi Engineering Plastics Co., Ltd., product name "Novaduran 5010L"
-Polyethylene terephthalate (PET) resin: manufactured by Teijin Chemicals Ltd., product name "TRN-8500FF"
-Polylactic acid (PLA) resin: manufactured by Natureworks, product name "Ingeo Biopolymer 4032D"

(Synthesis Example 1)
The diisocyanate compound shown in Table 1, the diol compound, and the terminal encapsulant were placed in a reaction vessel equipped with a reflux tube and a stirrer at the ratio shown in Table 1, stirred at 60 ° C. for 1 hour under a nitrogen stream, and then a carbodiimidation catalyst. Was added at the ratio shown in Table 1 and stirred at 100 ° C. for 3 hours.
Then, by infrared absorption (IR) spectrum measurement, it was confirmed that the absorption peak due to the isocyanate group having a wavelength of about 2270 cm ^-1 was almost eliminated, and a carbodiimide compound P1 having m = 1 and n = 2 was obtained.

(Synthesis Example 2)
In Synthesis Example 2, the diisocyanate compound shown in Table 1, the diol compound, the terminal encapsulant, and the carbodiimidization catalyst were blended in the proportions shown in Table 1, but in the same manner as in Synthesis Example 1, m = A carbodiimide compound P2 having 1, n = 3 was obtained.

(Synthesis Example 3)
In Synthesis Example 3, the diisocyanate compound shown in Table 1, the diol compound, the terminal encapsulant, and the carbodiimidization catalyst were blended in the proportions shown in Table 1, but in the same manner as in Synthesis Example 1, m = A carbodiimide compound P3 having 1, n = 3 was obtained. As shown in Table 1, phenylisocyanate and isopropyl alcohol are used in combination as the end-capping agent, but if they are mixed, their functions as end-capping agents may be lost. After blending isopropyl alcohol first, phenyl isocyanate was blended with a sufficient time difference.

(Synthesis Example 4)
In Synthesis Example 4, the diisocyanate compound shown in Table 1, the diol compound, the terminal encapsulant, and the carbodiimidization catalyst were blended in the proportions shown in Table 1, but in the same manner as in Synthesis Example 1, m = A carbodiimide compound P4 having 1, n = 5 was obtained.

(Synthesis Example 5)
The diisocyanate compound and the diol compound shown in Table 1 are placed in a reaction vessel equipped with a reflux tube and a stirrer, the terminal sealant shown in Table 1 is added while stirring, and the mixture is stirred at 100 ° C. for 2 hours under a nitrogen stream, and then carbodiimide. A chemical catalyst was added and the mixture was stirred at 100 ° C. for 3 hours. The blending ratio of each component was as shown in Table 1.
Then, by infrared absorption (IR) spectrum measurement, it was confirmed that the absorption peak due to the isocyanate group having a wavelength of about 2270 cm ^-1 was almost eliminated, and a carbodiimide compound P5 having m = 1 and n = 5 was obtained.

(Synthesis Example 6)
In Synthesis Example 6, the diisocyanate compound shown in Table 1, the diol compound, the terminal encapsulant, and the carbodiimidization catalyst were blended in the proportions shown in Table 1, but in the same manner as in Synthesis Example 1, m = A carbodiimide compound P6 having 1, n = 5 was obtained.

(Synthesis Example 7)
In Synthesis Example 7, the diisocyanate compound shown in Table 1, the diol compound, the terminal encapsulant, and the carbodiimidization catalyst are blended at the ratios shown in Table 1, and stirring under a nitrogen stream is performed at 60 ° C. for 1 hour. A carbodiimide compound P7 having m = 1 and n = 5 was obtained in the same manner as in Synthesis Example 1 except that the temperature was changed from 1 to 160 ° C. for 2 hours.

(Synthesis Example 8)
In Synthesis Example 8, the diisocyanate compound shown in Table 1, the diol compound, the terminal encapsulant, and the carbodiimidization catalyst were blended in the proportions shown in Table 1, but in the same manner as in Synthesis Example 1, m = A carbodiimide compound P8 having 1, n = 8 was obtained.

(Synthesis Example 9)
In Synthesis Example 9, the diisocyanate compound shown in Table 1, the diol compound, the terminal encapsulant, and the carbodiimidization catalyst are blended at the ratios shown in Table 1, and stirring at 100 ° C. after adding the carbodiimided catalyst is performed. A carbodiimide compound P9 having m = 1 and n = 4 was obtained in the same manner as in Synthesis Example 1 except that the time was changed from 3 hours to 4 hours.

(Synthesis Example 10)
In Synthesis Example 10, the diisocyanate compound shown in Table 1 and the carbodiimidization catalyst were placed in a reflux tube and a reaction vessel equipped with a stirrer at the ratio shown in Table 1, stirred at 180 ° C. for 4 hours under a nitrogen stream, and then the temperature was raised to 150 ° C. I lowered it. Then, the diol compound and the terminal encapsulant were added at the ratios shown in Table 1, and the mixture was stirred at 150 ° C. for 1 hour.
Then, by infrared absorption (IR) spectrum measurement, it was confirmed that the absorption peak due to the isocyanate group having a wavelength of about 2270 cm ^-1 was almost eliminated, and a carbodiimide compound P10 having m = 1 and n = 6 was obtained.

(Synthesis Example 11)
In Synthesis Example 11, the diisocyanate compound shown in Table 1, the diol compound, the terminal encapsulant, and the carbodiimidization catalyst were blended in the proportions shown in Table 1, but in the same manner as in Synthesis Example 1, m = A carbodiimide compound P11 having 1, n = 6 was obtained.

(Example 1)
98 parts by mass of PBT resin as polyester resin (A) was melted under the condition of 250 ° C. using a lab mixer, and then carbodiimide compound P1: 2 mass obtained as carbodiimide compound (B) in Synthesis Example 1. Parts were added and mixed for 3 minutes to obtain a polyester resin composition.

(Example 2)
In Example 2, the same method as in Example 1 was used except that the blending amount of the PBT resin was changed from 98 parts by mass to 95 parts by mass and the blending amount of the carbodiimide compound P1 was changed from 2 parts by mass to 5 parts by mass. A polyester resin composition was obtained.

(Examples 3 to 10)
In Examples 3 to 10, the carbodiimide compounds P2 to 9 obtained in Synthesis Examples 2 to 9 are used in place of the carbodiimide compounds P1 obtained in Synthesis Example 1, and the amounts of the PBT resin and each carbodiimide compound compounded. A polyester resin composition was obtained in the same manner as in Example 1 except that the ratios shown in Table 2 were set.

(Comparative Examples 1 and 2)
In Comparative Examples 1 and 2, the same method as in Example 1 was used except that the carbodiimide compounds P10 and 11 obtained in Synthesis Examples 10 and 11 were used in place of the carbodiimide compound P1 obtained in Synthesis Example 1. A polyester resin composition was obtained.

(Comparative Example 3)
In Comparative Example 3, the same method as in Example 1 was used except that the blending amount of the PBT resin was changed from 98 parts by mass to 85 parts by mass and the blending amount of the carbodiimide compound P1 was changed from 2 parts by mass to 15 parts by mass. A polyester resin composition was obtained.

(Examples 11 to 20 and Comparative Examples 4 to 6)
In Examples 11 to 20 and Comparative Examples 4 to 6, PET resin was used instead of PBT resin, and Examples 1 to 10 and Comparative Examples 1 to 3 were used, respectively, except that the melting temperature was changed from 250 ° C. to 280 ° C. A polyester resin composition was obtained in the same manner as in the above.

(Examples 21 to 30 and Comparative Examples 7 to 9)
In Examples 21 to 30 and Comparative Examples 7 to 9, PLA resin was used instead of PBT resin, and Examples 1 to 10 and Comparative Examples 1 to 3, respectively, except that the melting temperature was changed from 250 ° C. to 200 ° C. A polyester resin composition was obtained in the same manner as in the above.

[Evaluation]
The polyester-based resin compositions according to the above Examples and Comparative Examples were evaluated for the characteristics shown below. The results are shown in Tables 2-4.

[1] Isocyanate gas generation (Examples 1 to 20 and Comparative Examples 1 to 6)
The melt-kneaded polyester resin composition was heated at 300 ° C. for 20 minutes, and the gas generated by GC-MS was analyzed.
For GC-MS, a product name "6890GC system" manufactured by Shimadzu Corporation was used.
The smaller the detected amount (generated amount) of the isocyanate gas, the more preferable, and the evaluation was made at the following detection levels according to the detected amount.
<Detection level and its reference value>
A: When the detected amount of isocyanate gas is less than 500 ppm B: When the detected amount of isocyanate gas is 500 ppm or more and less than 1000 ppm C: When the detected amount of isocyanate gas is 1000 ppm or more

(Examples 21 to 30 and Comparative Examples 7 to 9)
In Examples 21 to 30 and Comparative Examples 7 to 9, gas analysis was performed in the same manner as in Example 1 and the like except that the heating temperature was changed from 300 ° C. to 200 ° C., and the detection amount of isocyanate gas was evaluated. went.

[2] Strength retention (hydrolysis resistance)
(Examples 1 to 10 and Comparative Examples 1 to 3)
As an evaluation index of hydrolysis resistance, the strength retention rate (%) after the highly accelerated life test was determined by the following method.
<Highly accelerated life test>
The melt-kneaded polyester resin composition was flat-plate 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 strip sheet having a width of 10 mm and a length of 70 mm was prepared from the sheet.
The strip sheet was placed in an advanced accelerated life test device (HAST CHAMBER EHS-210M manufactured by ESPEC) and held at 121 ° C. and 100% RH for 72 hours and 120 hours to perform an advanced accelerated life test.
<Measurement of tensile strength>
The tensile strength was measured under the following conditions for each of the sample before the test, the sample after 72 hours of the test, and the sample after 120 hours of the test.
The tensile strength was measured at room temperature (20 ° C. ± 5 ° C.) using a tensile tester (manufactured by INSTRON, product name "INSTRON3365"). The measurement was performed at 5 points (5 strip sheets) for each sample, and the average value of the measured values (N = 5) was taken as the tensile strength of the sample.
<Calculation of strength retention rate>
The strength retention rate (%) was calculated by the following formula (I) as the ratio of the tensile strength of the sample after the lapse of 72 hours or 120 hours of the test to the sample before the test.
Strength retention = [tensile strength after test] / [tensile strength before test] x 100 (%) ... (I)
The larger the value of the strength retention rate, the more the tensile strength is maintained before and after the high acceleration life test, and it means that the polyester resin composition is excellent in hydrolysis resistance.

(Examples 11 to 20 and Comparative Examples 4 to 6)
In Examples 11 to 20 and Comparative Examples 4 to 6, the strength was increased in the same manner as in Example 1 except that the holding time in the advanced accelerated life test was changed from 72 hours and 120 hours to 24 hours and 40 hours. The retention rate was calculated.

(Examples 21 to 30 and Comparative Examples 7 to 9)
In Examples 21 to 30 and Comparative Examples 7 to 9, in the advanced accelerated life test, a constant temperature and humidity controller (PH-2KT-E manufactured by ESPEC) was used instead of the advanced accelerated life test device, and the holding condition was set to 85. The strength retention rate was determined by the same method as in Example 1 and the like except that the retention was changed to 24 hours and 48 hours under the conditions of ° C. and 85% RH.

As shown in Tables 2 to 4, the polyester resin compositions (Examples 1 to 30) containing the carbodiimide compounds P1 to P9, which are the carbodiimide compounds (B) specified in the present invention, in a predetermined ratio are hydrolyzed resistant. It was confirmed that the property was excellent and isocyanate gas was hardly generated (detection levels A and B).

On the other hand, polyester resin compositions containing carbodiimide compounds P10 and P11 other than the carbodiimide compound (B) specified in the present invention (Comparative Examples 1, 2, 4, 5, 7 and 8) and the present invention specify. The polyester-based resin compositions (Comparative Examples 3, 6 and 9) containing the carbodiimide compound P1 which is the carbodiimide compound (B) but containing too much of the carbodiimide compound P1 are the polyester-based resin compositions of the present invention (Examples 1 to 30). It was confirmed that the amount of isocyanate gas generated was large (detection level C) in all cases.

When the carbodiimide compounds P10 and P11 other than the carbodiimide compound (B) specified in the present invention are contained, the polyester-based resin obtained depends on the relationship with the type of polyester-based resin (A) to be combined (for example, PBT resin). It was confirmed that the hydrolysis resistance of the resin composition deteriorated.
Further, it was confirmed that when the content of the carbodiimide compound is too large, the hydrolysis resistance of the obtained polyester resin composition deteriorates regardless of the type of the polyester resin (A) to be combined.

Claims

A polyester resin composition containing a polyester resin (A) and a carbodiimide compound (B) represented by the following general formula (1).
A polyester resin composition in which the content of the carbodiimide compound (B) is 0.1 to 10 parts by mass with respect to 100 parts by mass of the total amount of the polyester resin (A) and the carbodiimide compound (B). ..

(In the general formula (1), R 1 and R 4 represent residues excluding the functional group of an organic compound having one functional group capable of reacting with an isocyanate group, and R 1 and R 4 are the same but different. R 2 represents a divalent residue obtained by removing two isocyanate groups from the diisocyanate compound, and the diisocyanate compound has a benzene-based aromatic ring that is directly bonded to the isocyanate group, and the benzene-based aromatic ring is used. The structure has no substituent or only one substituent at both ortho positions of the ring at the position where it is bonded to the isocyanate group. R 3 is a divalent residue obtained by removing two hydroxyl groups from the diol compound. Representing a group. X 1 and X 2 represent a group formed by the reaction of the functional group of the organic compound with the isocyanate group of the diisocyanate compound, and X 1 and X 2 may be the same or different. n and m represent numbers from 1 to 20.)
The polyester-based resin composition according to claim 1, wherein the diisocyanate compound contains at least one selected from toluene diisocyanate, trizine diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate and paraphenylenedi isocyanate.
The diisocyanate compound contains a mixture of 2,4'-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate.
When the total amount of the diisocyanate compound is 100 mol%, the ratio of the 2,4'-diphenylmethane diisocyanate is 30 to 70 mol%, and the ratio of the 4,4'-diphenylmethane diisocyanate is 30 to 70 mol%. The polyester-based resin composition according to claim 2.
When the total amount of the diisocyanate compound is 100 mol%, the ratio of the 2,4'-diphenylmethane diisocyanate is 50 to 60 mol%, and the ratio of the 4,4'-diphenylmethane diisocyanate is 40 to 50 mol%. The polyester-based resin composition according to claim 3.
Any one of claims 1 to 4, wherein the organic compound having one functional group capable of reacting with the isocyanate group is at least one selected from monoisocyanate, monoalcohol, monoamine, monocarboxylic acid and acid anhydride. The polyester-based resin composition according to the section.
The polyester-based resin composition according to any one of claims 1 to 5, wherein the diol compound is one or more selected from a polyether polyol, a polyester polyol, a polycarbonate polyol, and an alkane diol.
The one according to any one of claims 1 to 6, wherein the polyester resin (A) is at least one selected from polyethylene terephthalate, polybutylene terephthalate, polybutylene succinate, polylactic acid, and polyhydroxyalkanoic acid. Polyester resin composition.