JP2023132798A - Polyether polyol and polyester - Google Patents

Abstract

To make a polyester that retains flexibility and has improved gas barrier and aroma retention properties, by providing a polyether polyol as a structural unit of the polyester.SOLUTION: The polyether polyol comprises a structural unit derived from an alkylene diol (hereinafter referred to as "structural unit A") and a structural unit derived from a compound represented by the formula (1) in the figure (hereinafter referred to as "structural unit B"). In Formula (1), m and n are integers equal to or greater than 1; and R1 and/or R2 are groups represented by -R3-O-R4-R5 or -R3-O-R5, and if only one of R1 and R2 is -R3-O-R4-R5 or -R3-O-R5 then the other is a hydrogen atom or an alkyl group having 6 or less carbon atoms (where R3 is an alkylene group having 1 to 5 carbon atoms; R4 is an alkylene group having 1 to 5 carbon atoms; and R5 is an aromatic group.)SELECTED DRAWING: None

Description

The present invention relates to polyether polyols and polyesters. Specifically, the present invention relates to a polyether polyol that is a raw material for polyester and the like, and a polyester containing a structural unit derived from this polyether polyol.

Polyester occupies an important position in industry due to its excellent mechanical and chemical properties. For example, aromatic polyesters such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT) are resins with excellent heat resistance and chemical resistance, and are used in fibers, films, sheets, bottles, etc. due to their ease of molding and economy. It is widely used in fields such as extrusion molding and injection molding of electrical and electronic parts, automobile parts, precision equipment parts, etc. However, in recent years, there has been a demand for polyester that maintains the basic properties of polyester while adding new functions such as flexibility, gas barrier properties, low-temperature properties, and impact resistance. It is also desired to efficiently produce such polyesters.

Patent Document 1 describes that PBT is copolymerized with polytetramethylene oxide glycol, and it is said that flexibility can be imparted. Patent Document 2 discloses a polyether polyol having a specific number average molecular weight and a specific molecular weight distribution, and it is said that a polyester elastomer using the same has excellent flexibility and elastic recovery.

Japanese Unexamined Patent Publication No. 49-31795 JP2017-25282A

However, with the previously known polyether polyols, the polyesters produced using them lack gas barrier properties and fragrance retention properties, and the polyesters cannot be used in the form of thin films such as films for packaging such as food applications. was difficult.
The present invention was made in view of the above problems, and provides a polyether polyol that is a structural unit of the polyester in order to obtain a polyester that maintains flexibility and has improved gas barrier properties and fragrance retention properties. The task is to do so.

As a result of intensive studies on the above-mentioned problems, the present inventors found that by creating a polyether polyol containing a structural unit derived from an alkylene diol and a structural unit derived from a specific compound, structural units derived from the polyether polyol can be obtained. The present inventors have discovered that a polyester containing the following polyester retains flexibility and has improved gas barrier properties and fragrance retention properties, and has completed the present invention.

The present invention has been achieved based on such knowledge, and has the following gist [1] to [7].
[1] A structural unit derived from alkylene diol (hereinafter referred to as "structural unit A"), and
A polyether polyol containing a structural unit (hereinafter referred to as "structural unit B") derived from a compound represented by the following formula (1).

(In formula (1), m and n are integers of 1 or more, and R ¹ and/or R ² are -R ³ -O-R ⁴
-R ⁵ or -R ³ -O-R ⁵ , and only one of R ¹ and R ² is -R ³ -O
When it is -R ⁴ -R ⁵ or -R ³ -O-R ⁵ , the other is a hydrogen atom or an alkyl group having 6 or less carbon atoms. (R ³ is an alkylene group having 1 to 5 carbon atoms, R ⁴ is an alkylene group having 1 to 5 carbon atoms, and R ⁵ is an aromatic group.)
[2] The polyether polyol has a number average molecular weight of 500 or more and 5,000 or less,
The polyether polyol described in [1].
[3] The polyether polyol according to [1] or [2], wherein the compound represented by formula (1) includes a compound where m is 1 and n is 1.
[4] The polyether polyol according to any one of [1] to [3], wherein the alkylene diol contains 1,4-butanediol.
[5] A polyester containing a structural unit derived from the polyether polyol according to any one of [1] to [4], a structural unit derived from a dicarboxylic acid component, and a structural unit derived from a diol component.
[6] The polyester according to [5], wherein the dicarboxylic acid component has an alicyclic dicarboxylic acid component as a main component.
[7] The polyester has an intrinsic viscosity of 0.20 dL/g to 1.60 dL/g [5]
Or the polyester described in [6].

According to the polyether polyol of the present invention, the polyester having the polyether polyol as a structural unit can maintain flexibility and improve gas barrier properties and fragrance retention properties.

Hereinafter, embodiments of the present invention will be described in detail, but the explanation of the constituent elements described below is an example of the embodiment of the present invention, and the present invention is not limited to these contents. In this specification, a numerical range expressed using "~" means a range that includes the numerical values written before and after "~" as the lower limit and upper limit.
Moreover, in this specification, "containing as a main component" means that it accounts for 70 mol% or more of the component. For example, "a dicarboxylic acid component containing a terephthalic acid component as a main component" means that the terephthalic acid component accounts for 70 mol% or more of the total acid components constituting the polyester.

<Polyether polyol>
The polyether polyol of the present invention has a structural unit derived from an alkylene diol (hereinafter referred to as "
It is called "structural unit A". ), and a structural unit derived from the compound represented by the following formula (1) (hereinafter referred to as "structural unit B").

(In formula (1), m and n are integers of 1 or more, and R ¹ and/or R ² are -R ³ -O-R ⁴
-R ⁵ or -R ³ -O-R ⁵ , and only one of R ¹ and R ² is -R ³ -O
When it is -R ⁴ -R ⁵ or -R ³ -O-R ⁵ , the other is a hydrogen atom or an alkyl group having 6 or less carbon atoms. (R ³ is an alkylene group having 1 to 5 carbon atoms, R ⁴ is an alkylene group having 1 to 5 carbon atoms, and R ⁵ is an aromatic group.)
The compound represented by the formula (1) (sometimes referred to as "compound B") is the compound represented by the formula (1)
It is preferable to include a compound in which m is 1 and n is 1. Also, since it is easily available, only one of R ¹ and R ² is -R ³ -O-R ⁴ -R ⁵ or -R ³ -O-R ⁵
It is preferably a group represented by the following, and more preferably -R ³ -O-R ⁵ . Specific compounds include 2-phenoxymethyl-1,3-propanediol, 2-(1-naphthoxy)methyl-1,3-propanediol, and 2-(2-naphthoxy)methyl-1,3-
Propanediol, 2-methyl-2-phenoxymethyl-1,3-propanediol, 2
-Methyl-2-(1-naphthoxy)methyl-1,3-propanediol, 2-methyl-2
-(2-naphthoxy)methyl-1,3-propanediol, 2-ethyl-2-phenoxymethyl-1,3-propanediol, 2-ethyl-2-(1-naphthoxy)methyl-1,
3-propanediol, 2-ethyl-2-(2-naphthoxy)methyl-1,3-propanediol, 2,2-bis(phenoxymethyl)-1,3-propanediol, 2,2-bis[(1 -naphthoxy)methyl]-1,3-propanediol, 2,2-bis[(2-naphthoxy)methyl]-1,3-propanediol, 2-[(phenylmethoxy)methyl]
-1,3-propanediol, 2-[(2-naphthylmethoxy)methyl]-1,3-propanediol, (7,8-dihydro-6H-dibenzo[f,h][1,5]dioxonine-7 ,7-diyl)dimethanol, (9,10-dihydro-8H-dinaphtho[2,1-f
:1',h][1,5]dioxonine-7,7-diyl)dimethanol, (8,9-dihydro-7H-dinaphtho[2,3-f:2',3'-h][1, 5] Dioxonine-8,8
-diyl)dimethanol, but it is more preferable to include a compound in which the aromatic group of R ⁵ is a polycyclic aromatic group.

By using a polyether polyol containing a structural unit derived from the compound B, the polyester containing the polyether polyol as a structural unit can maintain flexibility and become a polyester with improved gas barrier properties and fragrance retention properties. There is sex.
The alkylene diol is preferably an alkylene diol having 2 to 6 carbon atoms, such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5
-pentanediol, 1,4-pentanediol, 2-methyl-1,4-butanediol, 1,6-hexanediol, but 1,4-butanediol, 1,4-pentanediol or 2- More preferably, it contains methyl-1,4-butanediol,
More preferably, it contains 4-butanediol. By using a polyether polyol containing a structural unit derived from the alkylene diol, the polyester containing the polyether polyol as a structural unit can maintain flexibility and become a polyester with improved gas barrier properties and fragrance retention properties. There is sex.

The content of structural unit A in the polyether polyol of the present invention is not particularly limited, but is preferably 15% by mass or more, more preferably 30% by mass or more, and further preferably 50% by mass or more, based on 100% by mass of the polyether polyol. preferable. Further, it is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 80% by mass or less. When the content of the structural unit A is within the above range, the polyester containing the polyether polyol as a structural unit may maintain flexibility and become a polyester with improved gas barrier properties and fragrance retention properties.

The content of structural unit B in the polyether polyol of the present invention is not particularly limited, but is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 20% by mass or more, based on 100% by mass of the polyether polyol. preferable. Also preferably 70% by mass or less, 60% by mass
The following is more preferable, and 50% by mass or less is even more preferable. When the content of the structural unit B is within the above range, there is a possibility that the polyester containing the polyether polyol as a structural unit maintains flexibility and becomes a polyester with improved gas barrier properties and fragrance retention properties. still,
The content of each structural unit of the polyether polyol can be calculated by analyzing it by NMR (nuclear magnetic resonance spectrum).

The ratio of the mass of structural unit B to the sum of the mass of structural unit A and the mass of structural unit B contained in the polyether polyol of the present invention is preferably 5% to 85%, and preferably 10% to
More preferably 70%, even more preferably 15% to 60%, 20%
Most preferably, it is between 50% and 50%. When the ratio is within the above range, there is a possibility that the polyester containing the polyether polyol as a structural unit maintains flexibility and becomes a polyester with improved gas barrier properties and aroma retention properties.

The polyether polyol of the present invention may contain structural units other than structural unit A and structural unit B. Other structural units include structural units derived from compounds having three or more hydroxyl groups, such as triols and tetraols. The content of other structural units is more preferably 20% by mass or less, even more preferably 10% by mass or less, based on 100% by mass of the polyether polyol. If the content of other structural units is too high,
Polyesters containing the polyether polyol as a structural unit may have reduced flexibility.

The structure and content of each structural unit of the polyether polyol can be determined by ¹ H-NMR analysis.
The number average molecular weight (Mn) of the polyether polyol of the present invention is preferably 500 or more and 5,000 or less. The lower limit is more preferably 600, even more preferably 700, and 800.
is particularly preferred. The upper limit is more preferably 4,000, even more preferably 3,000, and 2,000.
000 is particularly preferred. When the number average molecular weight is within the above range, there is a possibility that the polyester containing the polyether polyol as a structural unit has flexibility and has improved gas barrier properties and fragrance retention properties.

The number average molecular weight of polyether polyols can be determined by gel permeation chromatography (
It can be determined by the number average molecular weight in terms of polytetramethylene ether glycol measured by GPC).
Various additives can be added to the polyether polyol of the present invention as necessary.

For example, an antioxidant can be added to suppress deterioration due to oxidation. In this case, the antioxidant concentration in the polyether polyol after adding the antioxidant is preferably 1 mass ppm or more, more preferably 10 mass ppm or more, still more preferably 50 mass ppm or more, and preferably 5,000 mass ppm. Hereinafter, it is added so that the amount is more preferably 500 mass ppm or less, and even more preferably 300 mass ppm or less.

If the antioxidant concentration is too high, bleed-out or precipitation tends to occur. On the other hand, if the antioxidant concentration is too low, hue deterioration and oxidative deterioration tend to occur.
As the antioxidant, hindered phenol compounds, organic phosphite compounds, and organic phosphonite compounds are preferred from the viewpoint of effectiveness and stability.
<Production method of polyether polyol>
The polyether polyol of the present invention can usually be produced by ring-opening polymerization of at least two types of cyclic ethers and/or derivatives thereof in the presence of a catalyst. One of the two types of cyclic ether and/or its derivative (raw material A) is a compound that becomes structural unit A by ring-opening polymerization, and the number of carbon atoms forming the ring is preferably 2 to 6, and ethylene oxide , propylene oxide, oxetane, tetrahydrofuran (THF), tetrahydropyran, 1,4-dioxane, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, oxepane, and the like. Among these, it is more preferable to contain tetrahydrofuran, 2-methyltetrahydrofuran or 3-methyltetrahydrofuran, and even more preferable to contain tetrahydrofuran. Raw material A may be used alone or in combination of two or more.

The other of the two types of cyclic ether and/or its derivative (raw material B) is a compound that becomes structural unit B through ring-opening polymerization. Therefore, it is preferable that the raw material B is a compound represented by the following formula (2).

(In formula (2), p and q are integers of 1 or more, and R ⁶ and/or R ⁷ are -R ⁸ -O-R ⁹
-R ¹⁰ or -R ⁸ -O-R ¹⁰ , and only one of R ⁶ and R ⁷ is -R ⁸
When it is -O-R ⁹ -R ¹⁰ or -R ⁸ -O-R ¹⁰ , the other is a hydrogen atom or an alkyl group having 6 or less carbon atoms. (R ⁸ is an alkylene group having 1 to 5 carbon atoms, R ⁹ is an alkylene group having 1 to 5 carbon atoms, and R ¹⁰ is an aromatic group.)
In the compound represented by the formula (2), p is 1 and q is 1.
It is preferable to include a compound that is. Also, only one of R ⁶ and R ⁷ is -R ⁸ -O-R ⁹
A group represented by -R ¹⁰ or -R ⁸ -O-R ¹⁰ is preferable, and -R ⁸ -O-R ¹
More preferably, it is ⁰ .

Specific compounds include 3-(phenoxymethyl)oxetane, 3-[(1-naphthoxy)methyl]oxetane, 3-[(2-naphthoxy)methyl]oxetane, 3-methyl-3-(phenoxymethyl)oxetane. , 3-methyl-3-[(1-naphthoxy)methyl]oxetane, 3-methyl-3-[(2-naphthoxy)methyl]oxetane, 3-ethyl-
3-(phenoxymethyl)oxetane, 3-ethyl-3-[(1-naphthoxy)methyl]oxetane, 3-ethyl-3-[(2-naphthoxy)methyl]oxetane, 3,3-bis(
phenoxymethyl)-oxetane, 3,3-bis[(1-naphthoxy)methyl]oxetane, 3,3-bis[(2-naphthoxy)methyl]oxetane, 2-[(phenylmethoxy)methyl]oxetane, 2-[ (2-Naphthylmethoxy)methyl]oxetane, 6H,8
H-spiro[dibenzo[f,h][1,5]dioxonine-7,3'-oxetane], 8
H,10H-spiro[dinaphtho[2,1-f:1',2'-h][1,5]dioxonine-9,3'-oxetane],7H,9H-spiro[dinaphtho[2,3-f :2',3'-
h][1,5]dioxonine-8,3'-oxetane], but due to the availability of raw materials, 3-ethyl-3-(phenoxymethyl)oxetane and/or 3-ethyl-3-[
More preferably, it contains (2-naphthoxy)methyl]oxetane. Raw material B may be used alone or in combination of two or more.

In the production of the polyether polyol of the present invention, other raw materials (raw material C) other than the above two types of cyclic ethers and/or their derivatives may be used. Other raw materials include alkylene diols and/or derivatives thereof having 2 to 18 carbon atoms, cyclic ethers having 7 or more carbon atoms and/or derivatives thereof, and cyclic ethers having a hydroxyl group and/or derivatives thereof. A cyclic ether having a hydroxyl group and/or a derivative thereof is contained in the polyether polyol as another structural unit by ring-opening polymerization.

In the production of polyether polyol, the usage amounts and ratios of each of raw material A, raw material B, and raw material C are based on the content of structural unit A and structural unit B of the produced polyether polyol.
The content may be adjusted as appropriate so that it falls within a preferable range.
The catalyst used in the production of polyether polyol is not particularly limited as long as it is a catalyst capable of ring-opening polymerization of at least the raw material A and the raw material B, and either a homogeneous catalyst or a heterogeneous catalyst can be used. can. Examples of the homogeneous catalyst include fluorosulfuric acid, fuming sulfuric acid, hydrohalic acid, heteropolyacid, trifluoroborane, trispentafluorophenylborane, and aluminum trichloride. Examples of the heterogeneous catalyst include composite metal oxides, zeolites, metalloaluminosilicates, ion exchange resins, and activated clay, and several types of these may be combined. The amount of catalyst used is selected depending on the type of catalyst and manufacturing conditions. For example, when a metal oxide is used as a catalyst, the amount used is usually 0.01% by mass to 100% by mass, preferably 0.1% by mass to 100% by mass, based on the total amount of polyether polyol raw materials used. It is 20% by mass. If the amount of catalyst is too small, ring-opening polymerization may not proceed. Furthermore, if the amount of catalyst is too large, the physical properties of the produced polyester tend to deteriorate when polyester is produced using the produced polyether polyol as a raw material. In addition, when using a heterogeneous catalyst, the ring-opening polymerization may be carried out in the coexistence of water, a carboxylic acid and/or a carboxylic acid anhydride, etc. as an auxiliary agent. Carboxylic acids and carboxylic acid anhydrides include aliphatic carboxylic acids, aromatic carboxylic acids, and their anhydrides, and specifically include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, heptanoic acid, benzoic acid, Examples include phthalic acid, naphthalic acid and its anhydride, and mixtures thereof. Among these, acetic acid and acetic anhydride are preferred from the viewpoint of reactivity and product demand.

In addition, when using an auxiliary agent, since the molecular chain end of the product after ring-opening polymerization is an ester group, the molecular chain end is converted to a hydroxyl group by performing a hydrolysis reaction or transesterification reaction.
Can be converted to polyether polyols. For example, a polyether polyol can be obtained by mixing the product after ring-opening polymerization with an aliphatic alcohol having 1 to 4 carbon atoms and performing transesterification by an alcoholysis reaction in the presence of a transesterification catalyst.

The reaction temperature for producing polyether polyol is usually 0°C to 200°C, preferably 20°C.
~80°C. If the reaction temperature is too low, ring-opening polymerization tends to be delayed, leading to a decrease in productivity. Furthermore, if the reaction temperature is too high, by-products are likely to be produced, which tends to lead to a decrease in quality.
<Polyester>
The polyester of the present invention is obtained by using the polyether polyol of the present invention, and the polyester of the present invention is obtained by a normal polyester manufacturing method except for using the polyether polyol of the present invention, a dicarboxylic acid component, and a diol component. It can be manufactured by applying

The polyester of the present invention is prepared by subjecting the dicarboxylic acid component, the diol component, the polyether polyol of the present invention, and other copolymerizable components, if necessary, to a transesterification reaction and/or an esterification reaction. Obtained by polycondensation reaction.
A reaction catalyst can be used in the esterification reaction, transesterification reaction, and polycondensation reaction.

(dicarboxylic acid component)
Examples of the dicarboxylic acid component include the dicarboxylic acids and ester-forming derivatives thereof described below. Moreover, those manufactured by a petrochemical method and/or a manufacturing method having a fermentation process derived from biomass resources can also be used. As the ester-forming derivative of dicarboxylic acid, in addition to lower alcohol ester of dicarboxylic acid, ester-forming derivatives such as acid anhydrides and acid chlorides are preferred. Here, the lower alcohol usually refers to a straight-chain or branched-chain alcohol in which the alkyl group has 1 to 4 carbon atoms.

The dicarboxylic acid component is not particularly limited, but specifically includes oxalic acid, succinic acid,
Aliphatic chain dicarboxylic acids such as glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecadicarboxylic acid, dodecanedicarboxylic acid and their ester-forming derivatives (aliphatic chain dicarboxylic acid components);
Alicyclic dicarboxylic acids such as hexahydroterephthalic acid, hexahydroisophthalic acid, 1,4-cyclohexanedicarboxylic acid and dimethyl 1,4-cyclohexanedicarboxylate (1
, 4-DMCD) and other ester-forming derivatives of alicyclic dicarboxylic acids (alicyclic dicarboxylic acid components);
Terephthalic acid, phthalic acid, isophthalic acid, dibromoisophthalic acid, sodium sulfoisophthalate, phenylenedioxydicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4
, 4'-diphenyl ether dicarboxylic acid, 4,4'-diphenyl ketone dicarboxylic acid,
Aromatic dicarboxylic acids such as 4,4'-diphenoxyethane dicarboxylic acid, 4,4'-diphenylsulfone dicarboxylic acid, and 2,6-naphthalene dicarboxylic acid, and esters of aromatic dicarboxylic acids such as methyl terephthalate (DMT). Examples include formable derivatives (aromatic dicarboxylic acid components).

In addition to the above, examples of the ester-forming derivative include anhydrides such as succinic anhydride and adipic anhydride.
Among these, it is possible to obtain polyester that maintains both transparency and heat resistance.
Preferably, the main component is an alicyclic dicarboxylic acid component, and more preferably, the main component is 1,4-cyclohexanedicarboxylic acid and/or an ester-forming derivative of 1,4-cyclohexanedicarboxylic acid.

These dicarboxylic acid components may be used alone or in combination of two or more.
(Diol component)
Diol components include, but are not particularly limited to, ethylene glycol, diethylene glycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butylene glycol (1,4-BG), 1, 5-pentanediol,
Linear aliphatic diols such as neopentyl glycol, 1,6-hexanediol, 1,8-octanediol;
1,2-cyclohexanediol, 1,4-cyclohexanediol (1,4-CHD
O), cycloaliphatic diols such as 1,4-CHDM;
Aromatic diols such as xylylene glycol, 4,4'-dihydroxybiphenyl, 2,2-bis(4-hydroxyphenyl)propane, bis(4-hydroxyphenyl)sulfone;
Examples include diols derived from plant materials such as isosorbide, isomannide, isoidet, and erythritan.

In addition, ethylene glycol, 1,3-propanediol, neopentyl glycol, 1
, 4-BG, etc., may also be derived from biomass resources.
Among these, 1,4-BG, 1,4-CHD are preferred in terms of the physical properties of the polyester obtained.
O, 1,4-CHDM, ethylene glycol are preferred, especially 1,4-BG and 1,4-C
HDM is preferred.

These diol components may be used alone or in combination of two or more.
These diol components, in combination with dicarboxylic acid components, constitute the hard segment of the polyester.
The amount of the diol component is such that the molar amount of the entire glycol combined with the polyether polyol component described below is approximately equal to the molar amount of the dicarboxylic acid component. When the polyester contains "other copolymerizable components", the amount of the diol component is determined by taking this amount into account.

One type of polyether polyol may be used alone, or two or more types may be used in combination.
The content of structural units derived from polyether polyol in the polyester of the present invention is preferably 1 to 80% by mass, more preferably 5 to 65% by mass, and still more preferably 10 to 40% by mass. When the content is within this range, it becomes possible to obtain a polyester that is excellent in flexibility and has improved gas barrier properties and fragrance retention properties.

(Other copolymerizable components)
In addition to the dicarboxylic acid component, diol component, and polyether polyol, the polyester of the present invention may contain other copolymerizable components as necessary.
Other copolymerizable compounds that can be used as raw materials for polyester in the present invention include:
Hydroxycarboxylic acids and alkoxycarboxylic acids such as glycolic acid, p-hydroxybenzoic acid, and p-β-hydroxyethoxybenzoic acid; Monofunctional carboxylic acids such as stearic acid, behenic acid, benzoic acid, t-butylbenzoic acid, and benzoylbenzoic acid. Acids: tri- or higher-functional carboxylic acids such as tricarballylic acid, trimellitic acid, trimesic acid, pyromellitic acid, naphthalenetetracarboxylic acid, gallic acid; trimethylolethane, trimethylolpropane, glycerol, pentaerythritol, sugar ester Examples include polyfunctional alcohols having trifunctionality or higher.

The other copolymerizable components may be used alone or in combination of two or more.
The amount of other copolymerizable components used, that is, the content in the polyester of the present invention, is preferably 10% based on the total carboxylic acid component in the case of an acid, and based on the total diol component in the case of a hydroxyl group compound. Less than mol %, more preferably less than 5 mol %.

<Production method of polyester>
The polyester of the present invention can be produced by a transesterification reaction and/or esterification reaction step using a dicarboxylic acid component, a diol component, a polyether polyol, and other copolymerizable components used as necessary, and a process of transesterification and/or esterification reaction. It can be produced by a method in which a polyester is obtained through a polycondensation reaction of the oligomer obtained by the method and, if necessary, a polycondensation step in which solid-phase polycondensation is performed.

(Transesterification reaction and/or esterification reaction)
In the present invention, as a first step, a transesterification reaction and/or an esterification reaction between the dicarboxylic acid component, the diol component, and the polyether polyol are performed.
Normally, the dicarboxylic acid component and the polyether polyol are not distilled off in the polycondensation reaction described below following the transesterification reaction and/or the esterification reaction, but the diol component is not distilled off in the polycondensation reaction. There are things that are accepted and things that are not.

When using a diol component that can be distilled off in the polycondensation reaction, the molar amount of the entire glycol, which is the sum of the diol component and the polyether polyol, is used slightly larger than the molar amount of the dicarboxylic acid component, and the transesterification reaction and/or Alternatively, after all the dicarboxylic acid components are reacted in the esterification reaction, it is preferable to distill off unreacted diol components during the polycondensation reaction.
On the other hand, when using a diol component that cannot be distilled off in the polycondensation reaction, in order to sufficiently proceed the polycondensation reaction, the molar amount of the entire glycol, which is the sum of the diol component used and the polyether polyol, must be calculated by the molar amount of the dicarboxylic acid component. It is best to make it approximately equal to the amount.

That is, when using a diol component that can be distilled off in a polycondensation reaction, such as 1,4-BG, the total amount of glycol used, which is the sum of the diol component and polyether polyol, is 1.5% per mole of the dicarboxylic acid component. It is preferably 1 to 3.0 mol, more preferably 1.
1 to 1.5 mol is preferred. If this value is too small, the polycondensation reaction tends not to proceed sufficiently, and if it is too large, the production of THF due to decomposition of 1,4-BG tends to increase. In addition, when using a diol component such as 1,4-CHDM that cannot be distilled off in the polycondensation reaction, the amount is preferably 0.9 to 1.1 mol, more preferably 0.9 to 1.1 mol, per 1 mol of dicarboxylic acid component.
．． 98 to 1.02 mol is preferred. If this value is too small or too large, the polycondensation reaction tends not to proceed sufficiently.

Catalysts used in this first stage reaction include, for example, antimony compounds such as diantimony trioxide; germanium compounds such as germanium dioxide and germanium tetroxide; titanium alcoholates such as tetramethyl titanate, tetraisopropyl titanate, and tetrabutyl titanate; Titanium compounds such as titanium phenolates such as tetraphenyl titanate; dibutyltin oxide, methylphenyltin oxide, tetraethyltin, hexaethyldistin oxide, cyclohexahexyldistin oxide, didodecyltin oxide, triethyltin hydroxide, triphenyltin Tin compounds such as hydroxide, triisobutyltin acetate, dibutyltin diacetate; magnesium acetate,
Magnesium compounds such as magnesium hydroxide, magnesium carbonate, magnesium oxide, magnesium alkoxide, magnesium hydrogen phosphate, etc.; calcium compounds such as calcium acetate, calcium hydroxide, calcium carbonate, calcium oxide, calcium alkoxide, calcium hydrogen phosphate, etc. Examples include metal compounds containing atoms of Group 2A metals in the periodic table, as well as manganese compounds, zinc compounds, and the like. Among these, metal compounds containing titanium atoms and atoms of Group 2A metals in the periodic table are preferred, titanium compounds and tin compounds are particularly preferred, and tetrabutyl titanate is particularly preferred. These catalysts can be used alone or in combination of two or more.

These reaction catalysts are preferably added so that the concentration of metal derived from the reaction catalyst contained in the produced polyester falls within the following range.
In the case of transesterification, the amount of these catalysts used is usually 1 to 300 mass ppm, preferably 5 to 250 mass ppm, more preferably 10 to 200 mass ppm, particularly preferably 20-175 ppm by weight, most preferably 2
The amount is 5 to 150 ppm by mass. In the case of the esterification reaction, the amount of these catalysts used is usually 1 to 300 mass ppm, preferably 5 to 200 mass ppm, more preferably 1 to 100 mass ppm, particularly preferably 20-90 mass pp
m, most preferably 30 to 70 ppm by weight.

When the amount of catalyst added in the transesterification reaction and/or esterification reaction is within this range in terms of metal content in the polyester, the generation of foreign substances is suppressed, and the deterioration reaction and deterioration reaction during heat retention of the resulting polyester are suppressed. Gas generation is less likely to occur.
The transesterification reaction and/or esterification reaction conditions are arbitrary as long as the reaction can proceed, and the reaction temperature of the transesterification reaction is usually 120°C or higher, preferably 150°C or higher.
On the other hand, the reaction temperature for transesterification is usually 300°C or lower, preferably 280°C or lower, and more preferably 270°C or lower. In addition, the reaction time for transesterification is usually 2~
8 hours, preferably 2 to 6 hours, more preferably 2 to 4 hours.

The first stage reaction produces an oligomer in which the dicarboxylic acid component, diol component, and polyether polyol have reacted.
(polycondensation reaction)
Next, a polycondensation reaction (second stage reaction) of the oligomers produced in the first stage is performed. The polycondensation reaction is usually carried out by melt polycondensation reaction. The conditions for the melt polycondensation reaction are arbitrary as long as the reaction can proceed. The reaction temperature during the polycondensation reaction is preferably 300°C or lower, preferably 280°C or lower, and preferably 200°C or higher, more preferably 240°C or higher. When the reaction temperature is below the above upper limit, the thermal decomposition reaction during production is suppressed and the color tone tends to improve. When the reaction temperature is equal to or higher than the above lower limit, the polycondensation reaction tends to proceed efficiently.

As the polycondensation reaction catalyst, the catalyst species described in the transesterification reaction and/or esterification reaction can be used. The catalyst for the transesterification reaction and/or the esterification reaction may be used as it is as a polycondensation reaction catalyst, or a catalyst may be further added. It is preferable to add the amount in such a manner that the metal equivalent content of the polycondensation reaction catalyst in the polyester falls within the following range.

In the case of polycondensation following the transesterification reaction, the amount of catalyst added is usually 5 ppm to 300 ppm by mass, preferably 10 ppm to 20 ppm by mass, based on the metal content in the polyester.
0 mass ppm, more preferably 15 mass ppm to 150 mass ppm, particularly preferably 20 mass ppm
The range is from ppm to 100 ppm by weight, most preferably from 30 ppm to 50 ppm by weight.

In the case of polycondensation following the esterification reaction, the amount of catalyst added is usually 0.5 mass ppm to 300 mass ppm, preferably 1 mass ppm to 20 mass ppm in terms of metal content in the polyester.
0 ppm by weight, more preferably 3 ppm to 100 ppm by weight, particularly preferably 5 ppm to 50 ppm by weight, most preferably 10 ppm to 40 ppm by weight.
When the amount of catalyst added in the polycondensation reaction is within this range in terms of metal content in the polyester, the generation of foreign substances is suppressed, and deterioration reactions and gas generation during heat retention of the resulting polyester are less likely to occur.

The lower the pressure inside the reaction tank during the polycondensation reaction, the easier the reaction will progress, and the final stage is usually 27 kP.
a, preferably 20 kPa or less, more preferably 13 kPa or less, particularly preferably 0.4 kPa or less in at least one polycondensation reaction tank. The time required for the polycondensation reaction is adjusted by measuring the intrinsic viscosity of the polyester obtained and keeping the range constant, and is usually 2 to 12 hours, preferably 2 to 10 hours. When the polycondensation reaction is carried out in a continuous manner, the average residence time in the polycondensation reaction tank is regarded as the time required for the polycondensation reaction.

The polyether polyol is added to the reaction system from the start of the transesterification reaction and/or the esterification reaction until the end of the polycondensation reaction.
By adding polyether polyol during this time, it is possible to easily maintain the blocking properties as a copolymerization component and to obtain a polyester having a high melting point. The timing of addition is preferably from the start of the transesterification reaction and/or esterification reaction to the start of the polycondensation reaction in terms of addition operation and ensuring blocking properties.

After the polycondensation reaction is completed, the obtained polymer is taken out from the reaction tank in the form of a strand, and cut into pellets under or after cooling with water. The degree of polymerization of the pellets can be further increased by subjecting them to solid phase polycondensation, if necessary.
The solid phase polycondensation reaction is carried out under an atmosphere of an inert gas such as nitrogen, under reduced pressure, or under an inert gas flow. The reaction temperature is usually 180°C or higher, preferably 190°C or higher, and usually 240°C or lower, preferably 230°C or lower. The solid phase polycondensation reaction is carried out for a relatively long time until the desired intrinsic viscosity is reached. The reaction time for solid phase polycondensation is usually 5 to 20 hours, preferably 6 to 15 hours. Solid phase polycondensation can be carried out batchwise or continuously.

The polyester of the present invention may optionally contain stabilizers, antioxidants, fillers, antistatic agents,
A polyester composition can be prepared by blending various additives such as a mold release agent and a flame retardant, or PBT and other resins. Moreover, the polyester composition can also be used to form a molded article.
(Blending method)
The method of blending the various additives and resins described above is not particularly limited. Various additives can be added during or after the production of the polyester, and PBT and other resins can be added after the production of the polyester. When blending after producing polyester, it is preferable to use a single-screw or twin-screw extruder equipped with equipment that can devolatilize from a vent port as a kneader. Each component can be supplied to the kneader sequentially or can be supplied all at once. Alternatively, two or more components selected from each component may be mixed in advance.

(Molding method)
The polyester of the present invention and the composition containing the same can be produced into filaments by molding methods commonly used for thermoplastic resins, such as injection molding, blow molding, extrusion molding, press molding, stretch molding, and inflation molding. It can be made into various molded bodies including fibers, sheets, films, etc.

Preferred physical property values of the polyester of the present invention are listed below. The method for measuring each physical property is as described in the Examples section below.
(intrinsic viscosity)
The intrinsic viscosity (dL/g) of the polyester of the present invention is preferably 0.20 to 1.60, more preferably 0.50 to 1.50, even more preferably 0.70 to 1.30.

When the intrinsic viscosity is within this range, moldability is good and the molded product has excellent physical properties.
(melting point)
The melting point of the polyester of the present invention is preferably 100°C to 220°C, more preferably 150°C to 220°C.

When the melting point is within this range, it has excellent heat resistance to withstand use at high temperatures, has excellent thermal stability, and does not generate harmful gases even at high temperatures.

The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to the following Examples unless it exceeds the gist thereof.
[Measurement/evaluation method]
The methods for measuring physical properties and evaluation items adopted in the following examples are as follows.
<Number average molecular weight of polyether polyol>
The number average molecular weight (Mn) of the polyether polyol is a value measured under the following conditions.

After preparing a tetrahydrofuran solution of polyether polyol, use a GPC device [manufactured by Tosoh Corporation, product name "HLC-8220" or "HLC-8420" (column: TSKgelS
upperHZM-N (4 pieces)]. For GPC calibration, we used POLYTETRAHYDROFUR from POLYMER LABORATORIES, UK.
Use AN calibration kit.

<Analysis of structural units of polyether polyol>
The composition ratio of polyether polyol was calculated using ¹ H-NMR. Specifically, a polyether polyol was dissolved in deuterated chloroform (containing 0.03 v/v% TMS), ^{a 1} H-NMR spectrum was measured using a Bruker AVANCE 400 spectrometer, and the resulting spectrum was assigned. , calculated from the ratio of structural unit A to structural unit B. The measurement conditions were that the resonance frequency was 400 MHz, the number of integrations was 64, and the measurement temperature was room temperature.

<Intrinsic viscosity of polyester>
The viscosity was determined using a fully automatic viscosity measuring device (model DT553, capillary type) manufactured by Sentech Co., Ltd. in the following manner.
That is, a mixture of PTM11 (a mixture of phenol and 1,1,2,2-tetrachloroethane in a mass ratio of 1/1) was used as a solvent, and at 30°C, a sample solution with a concentration of 1.0 g/dL and only the solvent were used. The number of seconds for the drop to fall was measured and calculated using the following formula.

Intrinsic viscosity (dL/g) = ((1+4K _H η _sp ) ^0.5 -1)/(2K _H C)
(However, η _sp = η/η ₀ -1, η is the number of seconds the sample solution falls, η ₀ is the number of seconds the solvent falls,
C is the sample solution concentration (g/dL), and K _H is Huggins' constant. _KH was set at 0.33. )
<Melting point of polyester>
Measured by DSC (differential scanning calorimeter). Measurement conditions are -10℃ to 300℃
The temperature was raised at 20°C/min to 300°C, held at 300°C for 3 minutes, rapidly cooled at 20°C/min, and then raised again from -10°C to 300°C at 20°C/min until the peak of the endothermic peak reached 300°C. The temperature was taken as the melting point.

<Bending elastic modulus of polyester>
Strograph R2 manufactured by Toyo Seiki Seisakusho was used as a bending test device. A test piece with a length of 127 mm, width of 12.7 mm, and thickness of 3.1 mm was placed between two prismatic supports spaced apart by 100 mm, and a load was applied to the center at a constant speed (3 mm/min) to determine the deformation time. The stress and strain were measured. The bending elastic modulus was calculated from these measurement results. Note that the test piece was created by injection molding the obtained pellet.

Incidentally, the flexural modulus represents flexibility, and the smaller the value, the better the flexibility. Under the conditions of this example, if the flexural modulus is 450 MPa or less, preferably 420 MPa or less, more preferably 390 MPa or less, it can be judged that the film formability is good and flexibility is maintained.
<Gas permeability of polyester>
Two cells are separated by a test film with a thickness of 0.2 mm without a gap so that the permeation area is 50 ^mm2 , and one cell is filled with oxygen at 1 atm, and the other cell is left in a vacuum. It was left standing at room temperature. The amount of oxygen permeation was evaluated by measuring the internal pressure difference between both cells 24 hours after the cells were allowed to stand still.

Note that the oxygen permeation amount is a value representing gas barrier properties and aroma retention properties, and the smaller the value, the better the gas barrier properties and aroma retention properties. In this example, first, the evaluation is made in comparison with the oxygen permeation amount of a comparative example, which is a conventional technology, but the absolute value of the oxygen permeation amount under the conditions of this example is 5.
40mL/ ^m2・atm・24hr or less, preferably 500mL/ ^m2・atm・24h
If it is less than r, more preferably less than 460 mL/m ² ·atm · 24 hr, it can be judged that the gas barrier properties and fragrance retention properties are good.

[Example 1]
<Production of polyether polyol 1>
A jacketed pressure filtration device equipped with a mechanical stirrer, temperature sensor, reflux tube, and nitrogen bubbler was equipped with 3-ethyl-3-(phenoxymethyl)oxetane (hereinafter referred to as "EPOM").
210.0 g of acetic anhydride and 490.0 g of tetrahydrofuran were used as a raw material solution. After the raw material liquid was purged with nitrogen, it was heated with stirring. After the internal temperature reached 43° C., 35.0 g of ZrO ₂ /SiO ₂ catalyst was added to the raw material liquid to start the polymerization reaction. The polymerization reaction was continued while maintaining the internal temperature at 45°C. Six hours after the start of the polymerization reaction, the reaction solution was cooled, and the catalyst was removed by pressure filtration to obtain a polymerization solution.

250 g of the polymerization solution was placed in a mixing tank equipped with a stirrer, 250 g of methanol and 0.42 g of a methanol solution of sodium methoxide (concentration 24% by mass) were added, and the mixture was heated in an oil bath while stirring to start a methanolysis reaction. .
After 1 hour of total reflux from the start of methanol distillation, 250 g of methanol was distilled out. This was carried out twice in total, the methanolysis reaction was completed, and a methanolysis reaction solution was obtained.

The entire amount of the methanolysis reaction solution was placed in a mixing tank equipped with a stirrer, and heated with an external heating device to bring the internal temperature to 50°C. 30 mL of strongly acidic ion exchange resin (PK216LH) was washed with methanol, and then methanol was removed by drying. Furthermore, the strongly acidic ion exchange resin (PK
216LH) was swollen by adding methanol to 60 mL and added to the mixing tank. The internal temperature of the mixing tank was maintained at 48°C to 52°C, and the mixture was stirred and mixed for 30 minutes. After removing the coarse particles of the strongly acidic ion exchange resin (PK216LH) from the stirred mixture by decantation, the fine particles of the strongly acidic ion exchange resin (PK216LH) were filtered using a pressure filter to obtain a filtrate.
After concentrating the filtrate in an evaporator, it was transferred to a glass distillation apparatus, methanol was distilled off under reduced pressure at 90°C and a pressure of 8 hPa, and then the temperature was raised to 120°C and devolatilized under reduced pressure to obtain polyether polyol 1. I got it. The analysis results of polyether polyol 1 are shown in Table 1.

<Manufacture of polyester 1>
1 in a transesterification reaction tank equipped with a stirring device, nitrogen inlet, heating device, thermometer, and distillation tube.
, 4-cyclohexanedicarboxylic acid dimethyl (1,4-DMCD (cis form/trans form =
83.9 parts by mass of 1/9)), 1,4-cyclohexanedimethanol (1,4-CHDM
(cis form/trans form = 3/7)) and 37 parts by mass of polyether polyol 1.
．． 5 parts by mass were added to prepare a raw material liquid. As a catalyst, tetrabutyl titanate was added to the raw material liquid as a solution dissolved in butanol in an amount such that the amount was 61 mass ppm based on the produced polyester in terms of metal titanium. Next, the temperature of the raw material liquid was increased from 150°C to 200°C.
The temperature was raised over 60 minutes, and then maintained at 200°C for 60 minutes to carry out transesterification. During this time,
The transesterification reaction was carried out for a total of 120 minutes while distilling the methanol produced, and the reaction solution 1
And so.

After the completion of the transesterification reaction, tetrabutyl titanate was added to the reaction solution 1 as a solution dissolved in butanol in an amount such that the amount of tetrabutyl titanate was 33 mass ppm based on the produced polyester in terms of metal titanium. The reaction solution 1 containing butyl titanate was transferred to a polycondensation reaction tank equipped with a stirring device, a nitrogen inlet, a heating device, a thermometer, a distillation tube, and an exhaust port for reducing pressure, and the polycondensation reaction was carried out under the following reduced pressure conditions. I did it.

In the polycondensation reaction, the pressure inside the tank was gradually reduced from normal pressure to 0.4 kPa over 85 minutes, and then maintained at 0.4 kPa or less. The reaction temperature was raised from 200°C to 250°C over 45 minutes, and then maintained at 250°C. The reaction was continued and terminated when a predetermined stirring torque was reached. The time required for the polycondensation reaction was 180 minutes (the polycondensation reaction time was defined as the time from the start of pressure reduction to the time of pressure return with nitrogen).

Next, the pressure inside the polycondensation reactor was restored from the reduced pressure state with nitrogen, and then the pressure was increased to remove the polymer. The polymer was extruded from the die in the form of a strand with the heating medium temperature of the die being 235° C. during extraction, and then the strand was cooled in a cooling water tank, and then cut with a strand cutter and pelletized to obtain Polyester 1. Table 1 shows the evaluation results for Polyester 1.
It was shown to.

[Example 2]
<Production of polyether polyol 2>
3-Ethyl-3-[(2-naphthoxy)methyl]oxetane (hereinafter referred to as "ENOMO") 80.
0 g, 180.15 g of acetic anhydride, and 420.24 g of tetrahydrofuran were used as the raw material solution. After the raw material liquid was purged with nitrogen, it was heated in an oil bath while stirring. After the internal temperature reached 42° C., 30.025 g of ZrO ₂ /SiO ₂ catalyst was added to the raw material liquid to start the polymerization reaction. The polymerization reaction was continued while maintaining the internal temperature at 43°C to 48°C. From the start of the polymerization reaction, the reaction solution was sampled every 0.5 hours and the progress of the polymerization reaction was confirmed by ¹ H-NMR analysis. ENOMO was present in the reaction solution 4.5 hours after the start of the polymerization. Confirmed the disappearance of.
Five hours after the start of the polymerization reaction, the catalyst was removed from the reaction solution by decantation to obtain a polymerization solution.

200 g of the polymerization solution was placed in a reactor equipped with a stirrer, 500 mL of methanol and 0.57 g of a methanol solution of sodium methoxide (concentration 28% by mass) were added, and the mixture was heated in an oil bath with stirring to start the methanolysis reaction. From the time when the internal temperature reached 64 to 67°C, methanol was distilled off and additionally added as appropriate while checking the degree of conversion from terminal acetyl groups to hydroxyl groups of the polymerization reaction product by ¹ H-NMR analysis. The methanolysis reaction was continued. Six hours after the start of the methanolysis reaction, the conversion rate of terminal acetyl groups to hydroxyl groups exceeded 99.8%, the methanolysis reaction was completed, and a methanolysis reaction solution was obtained.

The entire amount of the methanolysis reaction solution was placed in a mixing tank equipped with a stirrer, and heated with an external heating device to bring the internal temperature to 50°C. 50 mL of a strongly acidic ion exchange resin (PK216LH) was washed with methanol, and then the methanol was removed by drying. Furthermore, the strongly acidic ion exchange resin (PK
216LH) was swollen by adding methanol to 60 mL and added to the mixing tank. The internal temperature of the mixing tank was maintained at 50°C to 51°C, and the mixture was stirred and mixed for 1 hour. After removing the coarse particles of the strongly acidic ion exchange resin (PK216LH) from the stirred mixture by decantation, the fine particles of the strongly acidic ion exchange resin (PK216LH) were filtered using a pressure filter to obtain a filtrate. . After concentrating the filtrate with an evaporator, it was transferred to a glass distillation apparatus, methanol was distilled off under reduced pressure at 90°C and a pressure of 8 hPa, and then the temperature was raised to 120°C and devolatilized under reduced pressure to obtain polyether polyol 2. I got it. The analysis results of polyether polyol 2 are shown in Table 1.

<Polyester 2>
Polyester was produced in the same manner as Polyester 1 in Example 1 except that Polyether Polyol 2 was used instead of Polyether Polyol 1, and Polyester 2 was obtained. The evaluation results for Polyester 2 are shown in Table 1.
[Comparative example 1]
<Polyester 3>
A polyester was produced in the same manner as Polyester 1 in Example 1, except that polytetramethylene ether glycol (PTMG1) having a number average molecular weight of 1,024 was used instead of Polyether Polyol 1, and Polyester 3 was obtained. The evaluation results for Polyester 3 are shown in Table 1.

As is clear from the above Examples and Comparative Examples, the polyesters (Polyester 1, Polyester 2) containing structural units derived from polyether polyols containing structural unit A and structural unit B contain structural units derived from PTMG. Compared to polyester (Polyester 3), the amount of oxygen permeation is small, and the value is 460 mL/m ² atm 24 hr or less, which clearly shows that it has excellent gas barrier properties and fragrance retention. It is. In addition, both Polyester 1 and Polyester 2 have a flexural modulus of 390 MPa or less and maintain flexibility.

From the above, by using the polyether polyol of the present invention, it is possible to obtain a polyester that maintains flexibility and has improved gas barrier properties and fragrance retention properties, such as:
It can be applied to packaging for food applications, etc.

Claims (7)

Polymer containing a structural unit derived from an alkylene diol (hereinafter referred to as "structural unit A") and a structural unit derived from a compound represented by the following formula (1) (hereinafter referred to as "structural unit B"). ether polyol.

(In formula (1), m and n are integers of 1 or more, and R ¹ and/or R ² are -R ³ -O-R ⁴
-R ⁵ or -R ³ -O-R ⁵ , and only one of R ¹ and R ² is -R ³ -O
When it is -R ⁴ -R ⁵ or -R ³ -O-R ⁵ , the other is a hydrogen atom or an alkyl group having 6 or less carbon atoms. (R ³ is an alkylene group having 1 to 5 carbon atoms, R ⁴ is an alkylene group having 1 to 5 carbon atoms, and R ⁵ is an aromatic group.) The polyether polyol according to claim 1, wherein the polyether polyol has a number average molecular weight of 500 or more and 5,000 or less. The polyether polyol according to claim 1 or 2, wherein the compound represented by the formula (1) includes a compound where m is 1 and n is 1. The polyether polyol according to any one of claims 1 to 3, wherein the alkylene diol comprises 1,4-butanediol. A structural unit derived from the polyether polyol according to any one of claims 1 to 4,
A polyester containing a structural unit derived from a dicarboxylic acid component and a structural unit derived from a diol component. The polyester according to claim 5, wherein the dicarboxylic acid component has an alicyclic dicarboxylic acid component as a main component. The polyester according to claim 5 or 6, wherein the polyester has an intrinsic viscosity of 0.20 dL/g to 1.60 dL/g.