Polyester, molded article, and method for producing molded article

Abstract

Provided are a polyester that has both good dielectric properties and excellent molding processability, a molded article, and a method for producing a molded article. A polyester includes: first monomer units from a first monomer having a furan ring with 2 carbonyl groups bonded thereto, and second monomer units having a condensed aromatic ring, wherein the content of the first monomer units is 0.1 mol% or more and 40 mol% or less relative to the total of all monomer units, and the content of the second monomer units is 20 mol% or more relative to the total of all monomer units.

Description

Technical Field

[0001] This disclosure relates to polyester, molded articles, and methods for manufacturing molded articles. Background Technology

[0002] Liquid crystal polyester has been developed for various applications, including electronic components, automotive parts, office automation components, and heat-resistant tableware.

[0003] For example, Patent Document 1 discloses an aromatic liquid crystal polyester film for capacitors, characterized in that it is formed from an aromatic liquid crystal polyester that exhibits optical anisotropy when molten.

[0004] Existing technical documents Patent Document 1: Japanese Patent Application Publication No. 2002-359145 Summary of the Invention

[0005] The problem that the invention aims to solve In recent years, from the perspective of expanding into more diverse applications and using more sophisticated components, there has been a demand for resins with high processability. However, with conventional liquid crystal polyesters, uneven thickness and perforations sometimes occur during film molding (especially during compression molding).

[0006] The purpose of this disclosure is to provide a polyester that combines good dielectric properties (also known as dielectric characteristics) and excellent molding processability. Furthermore, the purpose of this disclosure is to provide molded articles comprising this polyester and a method for manufacturing the same.

[0007] Methods for solving problems This disclosure provides, for example, the following solutions.

[0008] [1] A polyester comprising: The first monomer unit from the first monomer having a furan ring bonded with two carbonyl groups, and The second monomer unit has a fused aromatic ring. The content of the first monomer unit mentioned above is between 0.1 mol% and 40 mol% relative to the total content of all monomer units. The content of the second monomer unit mentioned above is more than 20 mol% relative to the total of all monomer units.

[0009] [2] The polyester according to [1], wherein 90 mol% or more of the total of all monomer units are monomer units having aromatic rings.

[0010] [3] The polyester according to [1] or [2] further comprises a third monomer unit having a benzene ring but not having a fused aromatic ring and a furan ring.

[0011] [4] The polyester according to [3], wherein the content of the third monomer unit is more than 10 mol% and less than 75 mol% relative to the total of all monomer units.

[0012] [5] The polyester according to any one of [1] to [4] has a 5% weight reduction temperature of 450°C or higher.

[0013] [6] A molded article comprising any one of [1] to [5] polyester.

[0014] [7] A method for manufacturing a molded article, comprising a step of molding a molding raw material containing any one of [1] to [5] to obtain a molded article.

[0015] [8] According to the manufacturing method described in [7], the above-mentioned process is a process of pressing the above-mentioned molding raw material into shape.

[0016] Invention Effects According to this disclosure, a polyester that combines good dielectric properties and excellent moldability can be provided. Furthermore, according to this disclosure, molded articles comprising the polyester and methods for manufacturing the same can also be provided. Detailed Implementation

[0017] The preferred embodiments of this disclosure will now be described in detail.

[0018] The polyester of this embodiment comprises: a first monomer unit derived from a first monomer having a furan ring bonded with two carbonyl groups, and a second monomer unit having a fused aromatic ring. In this embodiment, the content of the first monomer unit is 0.1 mol% or more and 40 mol% or less relative to the total number of monomer units constituting the polyester, and the content of the second monomer unit is 20 mol% or more relative to the total number of monomer units constituting the polyester.

[0019] The polyester of this embodiment exhibits good dielectric properties and excellent molding processability. The reasons for this effect may not be clear, but can be considered as follows.

[0020] The polyester of this embodiment contains more than 20 mol% of a second monomer unit having a fused aromatic ring, thus exhibiting good dielectric properties and a high 5% weight reduction temperature.

[0021] Polyesters with fused aromatic rings are prone to orientation due to the strong interactions between these rings. This leads to uneven resin expansion during molding (especially compression molding), sometimes resulting in defects such as uneven thickness and perforations. In this embodiment, it is argued that because the polyester contains a first monomer unit with a furan ring, the weak interactions between the fused aromatic rings and the furan ring are mitigated. Consequently, the linearity of the polymer chain is disrupted by the furan ring, making it easier for the chain to entangle. This results in more uniform resin expansion during molding (especially compression molding), reducing the likelihood of defects such as uneven thickness and perforations.

[0022] Furthermore, polyesters with fused aromatic rings exhibit good dielectric properties (and, in some cases, a higher 5% weight reduction temperature) due to the interaction between the fused aromatic rings. In this embodiment, it is believed that by employing furan rings, the stiffness of the polymer chain caused by the interaction between the fused aromatic rings is mitigated, and the decrease in dielectric properties (and, in some cases, a higher 5% weight reduction temperature) is suppressed by the intervention of the weak interaction between the fused aromatic rings and furan rings. Thus, it is possible to achieve both good dielectric properties (and, in some cases, a higher 5% weight reduction temperature) and excellent molding processability.

[0023] The polyester in this embodiment can be a polyester that exhibits liquid crystal properties in the molten state (i.e., a liquid crystal polyester). The polyester in this embodiment can be a single polymer or a mixture of two or more polymers. When the polyester is a mixture of two or more polymers, the content of each monomer unit described later represents the total amount of each monomer unit in the mixture. Furthermore, when the polyester is a mixture of two or more polymers, the parameters related to the polyester described later represent parameters of the mixture (parameters measured using the mixture). Additionally, the total of all monomer units represents the total number of monomer units constituting each polymer.

[0024] The polyester of this embodiment has structural units (monomer units) derived from raw material monomers. The polyester may have monomer units whose main monomer units (e.g., monomer units whose total percentage relative to all monomer units is 90 mol% or more, 95 mol% or more, or 99 mol% or more, preferably all monomer units) are monomer units having aromatic rings, i.e., monomer units derived from aromatic compounds. A polyester in which all monomer units are monomer units derived from aromatic compounds is also called a fully aromatic polyester. A liquid crystal polyester in which all monomer units are monomer units derived from aromatic compounds is also called a fully aromatic liquid crystal polyester.

[0025] It should be noted that, in this specification, "from" refers to a situation where, in the monomer unit of the polyester formed by the polymerization of the raw material monomer, the chemical structure of the functional groups that facilitate polymerization changes, while other structures remain unchanged. Here, "from" also includes the concept of polymerizable derivatives from the raw material monomer (e.g., compounds formed by converting the functional groups that facilitate polymerization of the raw material monomer into other polymerizable groups).

[0026] Aromatic compounds are compounds that have an aromatic ring. Suitable aromatic compounds as raw material monomers may have an aromatic ring and two or more polymerizable groups (e.g., hydroxyl, amino, or carboxyl groups, preferably hydroxyl or carboxyl groups) bonded to the aromatic ring.

[0027] Aromatic compounds may be, for example, compounds represented by formula (1-1) below (hereinafter also referred to as monomer (1-1)), compounds represented by formula (1-2) below (hereinafter also referred to as monomer (1-2)) or compounds represented by formula (1-3) below (hereinafter also referred to as monomer (1-3)).

[0028] X 1 -Ar 1 -Y 1 (1-1) X 2 -Ar 2 -X 3 (1-2) Y 2 -Ar 3 -Y 3 (1-3) [In the formula, Ar] 1 and Ar 2 Each of these groups independently represents a phenylene group, a biphenylene group, a fused polycyclic aromatic hydrocarbon group, or a group represented by formula (Z-1); Ar 3 This indicates a furanyl dimethyl group, a phenylene group, a biphenylene group, a fused polycyclic aromatic hydrocarbon group, or a group represented by formula (Z-1); Ar 1 Ar 2 and Ar 3 Some or all of the hydrogen atoms may be replaced by halogen atoms, alkyl groups, or aryl groups; X 1 X 2 and X 3 Each can be represented independently as either hydroxyl or amino; Y 1 Y 2 and Y 3 This indicates a carboxyl group. -Ar 4 -Z 1 -Ar 5 - (Z-1) [In the formula, Ar] 4 and Ar 5 Each can be used independently to represent either a phenylene group or a fused polycyclic aromatic hydrocarbon group. Z 1 This indicates an oxygen atom (-O-), a sulfur atom (-S-), a carbonyl group (-CO-), a sulfonyl group (-SO2-), or an alkyl dimethyl group. Monomer units derived from aromatic compounds can be exemplified by, for example, the monomer unit represented by equation (2-1) below (hereinafter also referred to as monomer unit (2-1)), the structural unit represented by equation (2-2) below (hereinafter also referred to as monomer unit (2-2)), or the structural unit represented by equation (2-3) below (hereinafter also referred to as monomer unit (2-3)). It should be noted that monomer unit (2-1) can be said to be a monomer unit derived from monomer (1-1), monomer unit (2-2) is a monomer unit derived from monomer (1-2), and monomer unit (2-3) is a monomer unit derived from monomer (1-3).

[0029] -X 11 -Ar 1 -Y 11 - (2-1) -X 12 -Ar 2 -X 13 - (2-2) -Y 12 -Ar 3 -Y 13 - (2-3) [In the formula, Ar] 1 Ar 2 and Ar 3 Same meaning as above; X 11 X 12 and X 13 Each can independently represent an oxygen atom (-O-) or an imino atom (-NH-); Y 11 Y 12 and Y 13 This represents a carbonyl group (-CO-). The phenylene oxide can be, for example, 1,4-phenylene oxide or 1,3-phenylene oxide, preferably 1,4-phenylene oxide.

[0030] For example, a biphenylene oxide can be 4,4'-biphenylene oxide.

[0031] A fused polycyclic aromatic hydrocarbon group is a group obtained by removing two hydrogen atoms from a fused polycyclic aromatic hydrocarbon. Examples of fused polycyclic aromatic hydrocarbons include naphthalene, anthracene, phenanthrene, benzo[a]phenylene, pyrene, benzo[a]phenanthrene, perylene, and fluorene. Among these, naphthalene is preferred from the viewpoint of availability and price.

[0032] The fused polycyclic aromatic hydrocarbon group can be naphthylene. For example, the naphthylene can be 2,6-naphthylene, 2,7-naphthylene, 1,4-naphthylene, 1,5-naphthylene, 1,6-naphthylene or 1,5-naphthylene, preferably 2,6-naphthylene.

[0033] Furandiyl is a group obtained by removing two hydrogen atoms from furan. Furandiyl can be, for example, 2,5-furandiyl, 2,4-furandiyl, 2,3-furandiyl or 3,4-furandiyl, preferably 2,5-furandiyl.

[0034] Halogen atoms that can be used as substituents include fluorine, chlorine, bromine, and iodine.

[0035] The alkyl group used as a substituent can be straight-chain, branched, or cyclic. For example, the alkyl group can have 1 to 10 carbon atoms. Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-hexyl, 2-ethylhexyl, n-octyl, and n-decyl.

[0036] The aryl group used as a substituent can be monocyclic or fused-ring. For example, aryl groups can have 6 to 20 carbon atoms. Examples of aryl groups include phenyl, o-tolyl, m-tolyl, p-tolyl, 1-naphthyl, and 2-naphthyl. An aryl group can be a group obtained by substituting an alkyl group for a hydrogen atom in the aromatic ring, such as tolyl.

[0037] Ar 1 Ar 2 and Ar 3 The number of substituents can be, for example, 0 to 2, 0 or 1, or 0.

[0038] Z 1 The alkyl diyl group can be straight-chain or branched. The alkyl diyl group can be an alkyl diyl group with 1 to 10 carbon atoms. Examples of alkyl diyl groups include methylene, ethane diyl, propane diyl (e.g., propane-2,2-diyl), butane diyl, octane diyl (e.g., octane-3,3-diyl), etc.

[0039] X 1 X 2 and X 3 Preferably, hydroxyl group, X 11 X 12 and X 13 Preferably, the monomer (1-1) is an oxygen atom (-O-). That is, monomer (1-1) can be an aromatic hydroxycarboxylic acid, and monomer (1-2) can be an aromatic diol. It should be noted that monomer (1-3) can be an aromatic dicarboxylic acid.

[0040] The polyester of this embodiment comprises a first monomer unit derived from a first monomer having a furan ring bonded with two carbonyl groups. The first monomer unit may be a monomer unit having a furan ring bonded with two carbonyl groups, a monomer unit derived from the first monomer having a structure formed by ring opening of the furan ring, or a monomer unit having a pyranone ring derived from the furan ring.

[0041] The first monolayer can be a monolayer equivalent to monolayer (2-3). For example, the first monolayer could be Ar. 3 It is a monomer unit (2-3) of furandiyl (preferably 2,5-furandiyl) (hereinafter also referred to as monomer unit (2-3-1)).

[0042] The first monomer can be a monomer equivalent to monomer (1-3). For example, the first monomer could be Ar. 3 It is a monomer (1-3) of furandiyl (preferably 2,5-furandiyl) (hereinafter also referred to as monomer (1-3-1)).

[0043] Examples of first monomers include 2,5-furandicarboxylic acid, 2,4-furandicarboxylic acid, 2,3-furandicarboxylic acid, and 3,4-furandicarboxylic acid, with 2,5-furandicarboxylic acid being preferred.

[0044] The polyester in this embodiment also includes a second monomer unit having a fused aromatic ring.

[0045] The fused aromatic rings that the second monomer unit may contain include, for example, naphthalene rings, anthracene rings, phenanthrene rings, tetraphenyl rings, pyrene rings, benzo[a]phenanthrene rings, perylene rings, fluorene rings, etc. Among these, naphthalene rings are preferred from the viewpoint of availability and price.

[0046] The second unit may be a unit equivalent to unit (2-1), a unit equivalent to unit (2-2), or a unit equivalent to unit (2-3). For example, the second unit may be a unit equivalent to unit (2-1) or unit (2-3).

[0047] The second monomer unit could be, for example, Ar. 1 The monomer unit (2-1) is a fused polycyclic aromatic hydrocarbon group (hereinafter also referred to as monomer unit (2-1-2)). It can also be Ar. 2 The monomer unit (2-2) is a fused polycyclic aromatic hydrocarbon group (hereinafter also referred to as monomer unit (2-2-2)). It can also be Ar. 3 The monomer unit (2-3) is a fused polycyclic aromatic hydrocarbon group (hereinafter also referred to as monomer unit (2-3-2)). In the second monomer unit, the fused polycyclic aromatic hydrocarbon group is preferably naphthylene, more preferably 2,6-naphthylene.

[0048] The second monomer unit can also be referred to as a monomer unit derived from a second monomer having a fused aromatic ring.

[0049] The second monomer can be a monomer equivalent to monomer (1-1), a monomer equivalent to monomer (1-2), or a monomer equivalent to monomer (1-3). For example, the second monomer can be a monomer equivalent to monomer (1-1) or monomer (1-3).

[0050] The second monomer could be, for example, Ar. 1 The monomer (1-1) is a fused polycyclic aromatic hydrocarbon group (hereinafter also referred to as monomer (1-1-2)). It can also be Ar. 2 The monomer (1-2) is a fused polycyclic aromatic hydrocarbon group (hereinafter also referred to as monomer (1-2-2)). It can also be Ar. 3 The monomer (1-3) is a fused polycyclic aromatic hydrocarbon group (hereinafter also referred to as monomer (1-3-2)). In the second monomer, the fused polycyclic aromatic hydrocarbon group is preferably naphthylene, more preferably 2,6-naphthylene.

[0051] Examples of second monomers include 2-hydroxy-6-naphthoic acid, 2,6-naphthoic acid, 2,6-dihydroxynaphthoic acid, 1,5-dihydroxynaphthoic acid, 2-hydroxy-3-naphthoic acid, 1-hydroxy-5-naphthoic acid, and 2,7-naphthodiol. 2-hydroxy-6-naphthoic acid and 2,6-naphthoic acid are preferred as second monomers.

[0052] The polyester of this embodiment may further include a third monomer unit having a benzene ring but not having a fused aromatic ring or a furan ring.

[0053] The third monomer unit can be a monomer unit equivalent to monomer unit (2-1), a monomer unit equivalent to monomer unit (2-2), or a monomer unit equivalent to monomer unit (2-3).

[0054] The third monomer unit could be, for example, Ar. 1 It is a phenylene, biphenylene, or a group represented by formula (Z-1) (wherein Ar) 4 and Ar 5 The monomer unit (2-1) (hereinafter also referred to as monomer unit (2-1-3) of phenylene) can also be Ar. 2 It is a phenylene, biphenylene, or group represented by formula (Z-1) (wherein Ar) 4 and Ar 5 The monomer unit (2-2) (hereinafter also referred to as monomer unit (2-2-3) of phenylene) can also be Ar. 3 It is a phenylene, biphenylene, or group represented by formula (Z-1) (wherein Ar)4 and Ar 5 The monomer unit (2-3) of the third monomer unit is (hereinafter also referred to as monomer unit (2-3-3)). In the third monomer unit, Ar... 1 Ar 2 and Ar 3 Preferably, it is phenylene or biphenylene, more preferably 1,4-phenylene, 1,3-phenylene or 4,4'-biphenylene, and even more preferably 1,4-phenylene or 4,4'-biphenylene.

[0055] The third monomer unit can also be referred to as a monomer unit derived from a third monomer that has a benzene ring but does not have a fused aromatic ring or a furan ring.

[0056] The third monomer can be a monomer equivalent to monomer (1-1), a monomer equivalent to monomer (1-2), or a monomer equivalent to monomer (1-3).

[0057] The third monomer could be, for example, Ar. 1 It is a phenylene, biphenylene, or a group represented by formula (Z-1) (wherein Ar) 4 and Ar 5 The monomer (1-1) (hereinafter also referred to as monomer (1-1-3) is a phenylene oxide, and can also be Ar. 2 It is a phenylene, biphenylene, or group represented by formula (Z-1) (wherein Ar) 4 and Ar 5 The monomer (1-2) (hereinafter also referred to as monomer (1-2-3) is a phenylene oxide, and can also be Ar. 3 It is a phenylene, biphenylene, or group represented by formula (Z-1) (wherein Ar) 4 and Ar 5 The monomer (1-3) is a phenylene group (hereinafter also referred to as monomer (1-3-3)). In the third monomer, Ar 1 Ar 2 and Ar 3 Preferably, it is phenylene or biphenylene, more preferably 1,4-phenylene, 1,3-phenylene or 4,4'-biphenylene, and even more preferably 1,4-phenylene or 4,4'-biphenylene.

[0058] Examples of third monomers include p-hydroxybenzoic acid, m-hydroxybenzoic acid, hydroquinone, resorcinol, 4,4'-dihydroxybiphenyl, terephthalic acid, isophthalic acid, and 4,4'-biphenyl dicarboxylic acid. The preferred third monomers are p-hydroxybenzoic acid, hydroquinone, 4,4'-dihydroxybiphenyl, terephthalic acid, or isophthalic acid.

[0059] The polyester in this embodiment may be composed of monomer unit (2-1), or it may be composed of monomer unit (2-1), monomer unit (2-2) and monomer unit (2-3).

[0060] When the polyester of this embodiment comprises monomer (2-1), monomer unit (2-2), and monomer unit (2-3), the content of monomer unit (2-1) relative to the total of all monomer units can be, for example, 10 mol% or more, or 20 mol% or more, 30 mol% or more, 40 mol% or more, 45 mol% or more, or 50 mol% or more. Furthermore, when the polyester of this embodiment comprises monomer (2-1), monomer unit (2-2), and monomer unit (2-3), the content of monomer unit (2-1) relative to the total of all monomer units can be, for example, 99 mol% or less, or 98 mol% or less, 95 mol% or less, 90 mol% or less, 85 mol% or less, 80 mol% or less, or 75 mol% or less.

[0061] When the polyester in this embodiment comprises monomer (2-1), monomer unit (2-2) and monomer unit (2-3), the content of monomer unit (2-2) and the content of monomer unit (2-3) can be approximately the same (for example, the difference is less than 3 mol%, less than 1 mol%, less than 0.5 mol%, or less than 0.1 mol%).

[0062] When the polyester of this embodiment comprises monomer (2-1), monomer unit (2-2), and monomer unit (2-3), the total content of monomer unit (2-2) and monomer unit (2-3) relative to the total content of all monomer units may be, for example, 0.2 mol% or more, or 1 mol% or more, 2 mol% or more, 5 mol% or more, 10 mol% or more, 15 mol% or more, 20 mol% or more, or 25 mol% or more. Furthermore, when the polyester of this embodiment comprises monomer (2-1), monomer unit (2-2), and monomer unit (2-3), the total content of monomer unit (2-2) and monomer unit (2-3) relative to the total content of all monomer units may be, for example, 90 mol% or less, or 80 mol% or less, 70 mol% or less, 60 mol% or less, 55 mol% or less, or 50 mol% or less.

[0063] The content of the first monomer unit relative to the total of all monomer units is 0.1 mol% or more. From the viewpoint of obtaining more significant effects from the furan ring described above, it can be 0.3 mol% or more, 0.5 mol% or more, 1 mol% or more, 2 mol% or more, or 5 mol% or more. Furthermore, the content of the first monomer unit relative to the total of all monomer units is 40 mol% or less. From the viewpoint of further improving dielectric properties and heat resistance, it can be 30 mol% or less, 20 mol% or less, 15 mol% or less, 10 mol% or less, or 5 mol% or less.

[0064] The content of the second monomer unit relative to the total of all monomer units is 20 mol% or more. From the viewpoint of further improving dielectric properties, it can be 25 mol% or more, 30 mol% or more, 35 mol% or more, 40 mol% or more, 45 mol% or more, 50 mol% or more, or 55 mol% or more. Furthermore, for conventional polyesters, the higher the content of fused aromatic rings, the more likely molding defects will occur due to the strong interactions between the fused aromatic rings. However, the polyester of this embodiment, through its combination with the first monomer unit, achieves excellent molding processability even when the content of fused aromatic rings is high (the content of the second monomer unit is high). Additionally, the content of the second monomer unit relative to the total of all monomer units can be, for example, 99 mol% or less, or 95 mol% or less, 90 mol% or less, 85 mol% or less, 80 mol% or less, or 75 mol% or less.

[0065] The content of the second monomer unit can be, for example, the remainder obtained by subtracting the contents of the first and third monomer units from the total content of all monomer units. That is, the upper limit of the content of the second monomer unit can be, for example, a value that makes the sum of the lower limit of the content of the first monomer unit and the lower limit of the content of the third monomer unit 100 mol%.

[0066] When the polyester in this embodiment contains a third monomer unit, the content of the third monomer unit relative to the total of all monomer units can, for example, be 10 mol% or more, and from the viewpoint of flowability, it can be 15 mol% or more, 20 mol% or more, or 25 mol% or more. Alternatively, the content of the third monomer unit relative to the total of all monomer units can, for example, be 75 mol% or less, or 70 mol% or less, 65 mol% or less, or 60 mol% or less.

[0067] The content of the third monomer unit can be, for example, the remainder obtained by subtracting the contents of the first and second monomer units from the total content of all monomer units. That is, the upper limit of the content of the third monomer unit can be, for example, a value that makes the sum of the lower limit of the content of the first monomer unit and the lower limit of the content of the second monomer unit 100 mol%.

[0068] In the polyester of this embodiment, the total amount of the first monomer unit, the second monomer unit and the third monomer unit relative to the total of all monomer units can be, for example, 90 mol% or more, 95 mol% or more, 97 mol% or more or 99 mol% or more, or 100 mol.

[0069] In this specification, the number of each monomer unit in the polyester is determined by the analytical method described in Japanese Patent Application Publication No. 2000-19168. Specifically, the polyester is depolymerized by reacting it with a lower alcohol in a supercritical state, and the depolymerization products (monomers from which each monomer unit is derived) are quantified using liquid chromatography, thereby calculating the number of each monomer unit relative to the total number of monomer units.

[0070] The flow initiation temperature of the polyester in this embodiment can be, for example, 200°C or higher. From the viewpoint of further improving shape stability under high-temperature conditions, it can be 220°C or higher, 240°C or higher, or 245°C or higher. Furthermore, the flow initiation temperature of the polyester in this embodiment can be, for example, 360°C or lower. From the viewpoint of mitigating temperature conditions during molding, it can be 330°C or lower, 325°C or lower, or 320°C or lower.

[0071] It should be noted that the flow onset temperature of the polyester in this specification was determined using a flow testing instrument, with the polyester subjected to a pressure of 9.8 MPa (100 kg / cm²). 2 Molten polyester was extruded from a nozzle with an inner diameter of 1 mm and a length of 10 mm while being heated at a rate of 4 °C / min under a load, and the viscosity of the polyester was 4800 Pa·s (48000 poise) at the temperature.

[0072] The 5% weight loss temperature of the polyester in this embodiment can be, for example, 450°C or higher, or 455°C or higher, 460°C or higher, or 465°C or higher. Polyesters with higher 5% weight loss temperatures generally exhibit superior heat resistance. The upper limit of the 5% weight loss temperature of the polyester in this embodiment is not limited; for example, it can be 550°C or lower, or 500°C or lower.

[0073] In this embodiment, the dielectric loss tangent of the polyester at 20 GHz can be, for example, 0.0050 or less, or 0.0040 or less, 0.0030 or less, or 0.0015 or less. It can be said that polyesters with lower dielectric loss tangents have superior dielectric properties. The lower limit of the dielectric loss tangent of the polyester in this embodiment at 20 GHz is not limited; for example, it can be 0.0005 or more, or 0.0010 or more.

[0074] The polyester of this embodiment has a relative permittivity of 4.0 or less, or 3.5 or less, 3.3 or less, or 3.2 or less at 20 GHz. A lower relative permittivity tends to result in better insulation. The polyester of this embodiment also has a relative permittivity of 2.5 or more, or 3.0 or more, 3.3 or more, or 3.4 or more at 20 GHz. A higher relative permittivity tends to increase the material's polarization susceptibility.

[0075] In addition, the dielectric loss tangent and relative permittivity of the polyester at 20 GHz were determined by the following method in this specification.

[0076] For the test piece of liquid crystal polyester, the dielectric loss tangent at 20 GHz at 23°C and 50%RH was measured using a vector network analyzer (e.g., Keysight Technologies Co., Ltd., N5290A) and a split cylindrical resonator (e.g., EM Labs Co., Ltd., CR710).

[0077] The polyester of this embodiment can be manufactured by polymerizing raw material monomers corresponding to the monomers constituting it. The polymerization method can be appropriately selected from known methods. For example, the polyester of this embodiment can be manufactured according to the method described in Japanese Patent No. 6439027.

[0078] The polyester of this embodiment is suitable for use as a molding raw material for obtaining molded articles. For example, the polyester can be used as granules, powders, etc.

[0079] The polyester of this embodiment can be used as a resin composition (resin composition) mixed with other components.

[0080] The resin composition may contain one or more resins other than the polyester of this embodiment. Examples of such resins include liquid crystal polyesters, polyolefins, cyclic polyolefins, polyvinyl chloride, polysulfone, (meth)acrylic resins, polyphenylene ether resins, polyacetal resins, polyamide resins, imide resins, cellulose resins, polyetheretherketone resins, fluororesins, polycarbonate resins, styrene-based resins, and thermosetting resins.

[0081] The resin composition may further include inorganic fillers, colorants, dispersants, plasticizers, antioxidants, curing agents, flame retardants, heat stabilizers, ultraviolet absorbers, antistatic agents, surfactants, lubricants, release agents, etc.

[0082] The resin composition is suitable for use as a molding raw material for obtaining molded articles. For example, the resin composition can be used as granules, powders, etc.

[0083] (Molded product) The molded article of this embodiment may be a molded article containing the polyester of this embodiment described above, or a molded article containing the resin composition described above.

[0084] The molded article of this embodiment can be a molded article obtained by molding a molding raw material containing the polyester of this embodiment.

[0085] There are no particular limitations on the molding method, but melt molding is preferred. Examples of melt molding methods include injection molding, extrusion molding, compression molding, blow molding, vacuum molding, foam molding, and compression molding. Among these, compression molding is preferred from the viewpoint of achieving the aforementioned effects more significantly.

[0086] There are no particular limitations on the conditions for compression molding. The molding temperature during compression molding can be any temperature higher than the flow start temperature of the polyester, for example, it can be 220~370℃ or 240~350℃.

[0087] The difference between the molding temperature during compression molding and the flow start temperature of the polyester (molding temperature - flow start temperature) can be, for example, 3°C or more, or 5°C or more, 10°C or more, or 15°C or more. Additionally, the difference between the molding temperature during compression molding and the flow start temperature of the polyester (molding temperature - flow start temperature) can be, for example, below 50°C, or below 40°C, 30°C or less, or 20°C or less.

[0088] The molded articles of this embodiment can be, for example, films, connectors, sockets, relay components, coil frames, optical pickups, oscillators, semiconductor packages, IC trays, wafer carriers, household appliance components, lighting fixture components, audio product components, optical cable ferrules, telephone components, fax components, modem components, release claws, heater brackets, impellers, fan gears, gears, bearings, motor components, motor housings, engine components, engine compartment components, electrical components, automotive interior trim components, microwave cooking pots, heat-resistant tableware, flooring materials, wall materials, beams, columns, roofing materials, aircraft components, spacecraft components, aerospace equipment components, nuclear reactors, marine facility components, washing fixtures, optical equipment components, valves, pipes, nozzles, filters, medical equipment components, medical materials, sensor components, sanitary spare parts, sporting goods, leisure goods, etc.

[0089] From the viewpoint of achieving the above-mentioned effects more significantly, the molded article of this embodiment can be a film.

[0090] The film thickness is not particularly limited; for example, it can be less than 1000 μm, or less than 300 μm, 250 μm, or 200 μm. For thinner films, defects caused by the interaction of the fused aromatic rings are more easily generated during molding, thus the aforementioned effects of the polyester of this embodiment can be obtained more significantly. The film thickness can, for example, be 10 μm or more, or 20 μm or more, or 50 μm or more.

[0091] The preferred embodiments of this disclosure have been described above, but this disclosure is not limited to the above embodiments.

[0092] Example The present disclosure will now be described in more detail through examples, but the present disclosure is not limited to these examples.

[0093] (Example A-1) In a reactor equipped with a stirrer, torque meter, nitrogen inlet pipe, thermometer, and reflux cooler, 188.2 g (1.0 mol) of 2-hydroxy-6-naphthoic acid, 62.1 g (0.33 mol) of 4,4'-dihydroxybiphenyl, 41.5 g (0.25 mol) of terephthalic acid, 13.0 g (0.08 mol) of 2,5-furandicarboxylic acid, and 195.7 g (1.92 mol) of acetic anhydride were added, along with 0.030 g of 1-methylimidazole as a catalyst. After fully purging the reactor with nitrogen, the temperature was raised to 145°C over a nitrogen flow for 30 minutes and maintained at that temperature under reflux for 1 hour.

[0094] Then, while distilling off the distillate byproducts of acetic acid and unreacted acetic anhydride, the temperature was increased to 310°C over 3 hours and 30 minutes. The reaction was considered complete when the specified torque increase was confirmed, and the contents of the reactor were removed. The flow start temperature of the obtained solid component was 272°C.

[0095] The obtained solid component was cooled to room temperature and pulverized to obtain a powder. The powder was then heated in a nitrogen atmosphere from room temperature to 260°C over 1 hour, and from 260°C to 290°C over 3 hours. The powder was held at 290°C for 5 hours to induce a solid-state polymerization reaction, yielding polyester (A-1). The flow onset temperature of the obtained polyester (A-1) was 327°C. The flow onset temperature was determined using the following method. Furthermore, the 5% weight loss temperature, molding processability, and dielectric properties of the obtained polyester (A-1) were evaluated using the following methods. The results are shown in Table 1.

[0096] <Determination of Flow Onset Temperature> The tests were performed using a flow testing apparatus (Shimadzu CFT-500 model). Specifically, approximately 2g of sample was filled into a capillary rheometer fitted with a die head having an inner diameter of 1mm and a length of 10mm. Then, the sample was tested at 9.8MPa (100kg / cm²). 2 Under a load of 4℃ / min, the sample was extruded from the nozzle and the temperature at which the melt viscosity showed 4800 Pa·s (48000 poise) was determined. This temperature was taken as the flow start temperature.

[0097] <Determination of 5% weight loss temperature> Using Shimadzu's "DTG-60A", a 10mg sample was heated under a nitrogen atmosphere at an initial temperature of 30°C and a heating rate of 10°C / min. The temperature at which the weight loss rate was 5% was determined.

[0098] <Evaluation of Molding Processability> Using a single-action compression molding machine NF-37 (manufactured by Shinto Metal Industry), a molded product is produced by hot-pressing a sample with a thickness of 0.2 mm at a temperature of +20°C and a set pressure of 0.1 MPa.

[0099] The presence or absence of perforations (number of perforations) and the difference between the maximum and minimum thickness measurements at any five points on the molded part (i.e., thickness non-uniformity) are used as evaluation criteria to assess moldability. Specifically, a case with no perforations and thickness non-uniformity less than 30 μm is rated "A"; a case with no perforations and thickness non-uniformity greater than 30 μm but less than 50 μm is rated "B"; a case with one or more but less than ten perforations and thickness non-uniformity greater than 30 μm but less than 50 μm is rated "C"; and a case with more than ten perforations or thickness non-uniformity greater than 50 μm is rated "D".

[0100] Evaluation of dielectric properties Using a single-action compression molding machine NF-37 (manufactured by Shinto Metal Industry), a molded product is produced by hot-pressing a sample with a thickness of 0.2 mm at a temperature of +20°C and a set pressure of 0.1 MPa.

[0101] For the obtained molded articles, the relative permittivity and dielectric loss tangent at 20 GHz were measured using a vector network analyzer (Keysight Technologies, Inc., N5290A) and a split cylindrical resonator (EM labs, Inc., CR710). The measurements were performed at 23°C and 50%RH.

[0102] (Example A-2) The components added to the reactor were changed to 172.5 g (0.92 mol) of 2-hydroxy-6-naphthoic acid, 42.5 g (0.39 mol (0.01 mol in excess) of hydroquinone), 63.1 g (0.29 mol) of 2,6-naphthoic acid, 13.0 g (0.08 mol) of 2,5-furandicarboxylic acid, 198.3 g (1.94 mol) of acetic anhydride, and 0.030 g of 1-methylimidazole. Otherwise, a powder of the solid components was obtained in the same manner as in Example A-1.

[0103] Next, the obtained powder was heated from room temperature to 250°C over 1 hour under a nitrogen atmosphere, then heated from 250°C to 280°C over 3 hours, and held at 280°C for 5 hours to carry out a solid-state polymerization reaction, yielding polyester (A-2). The flow onset temperature of the obtained polyester (A-2) was 324°C. The obtained polyester (A-2) was evaluated in the same manner as in Example A-1. The results are shown in Table 1.

[0104] (Example A-3) The components added to the reactor were changed to 188.2 g (1.0 mol) of 2-hydroxy-6-naphthoic acid, 18.9 g (0.17 mol) of hydroquinone, 31.0 g (0.17 mol) of 4,4'-dihydroxybiphenyl, 52.0 g (0.33 mol) of 2,5-furandicarboxylic acid, 196.8 g (1.93 mol) of acetic anhydride and 0.030 g of 1-methylimidazole. Otherwise, a powder of solid components was obtained in the same manner as in Example A-1.

[0105] Next, the obtained powder was heated from room temperature to 190°C over 1 hour under a nitrogen atmosphere, then heated from 190°C to 220°C over 3 hours, and held at 220°C for 5 hours to carry out a solid-state polymerization reaction, yielding polyester (A-3). The flow onset temperature of the obtained polyester (A-3) was 239°C. The obtained polyester (A-3) was evaluated in the same manner as in Example A-1. The results are shown in Table 1.

[0106] (Example A-4) The components added to the reactor were changed to 125.5 g (0.67 mol) of 2-hydroxy-6-naphthoic acid, 28.4 g (0.26 mol (0.01 mol in excess) of hydroquinone), 46.6 g (0.25 mol) of 4,4'-dihydroxybiphenyl, 78.0 g (0.50 mol) of 2,5-furandicarboxylic acid, 197.4 g (1.93 mol) of acetic anhydride, and 0.028 g of 1-methylimidazole. Otherwise, a powder of solid components was obtained in the same manner as in Example A-1.

[0107] Next, the obtained powder was heated from room temperature to 210°C over 1 hour under a nitrogen atmosphere, and then from 210°C to 240°C over 3 hours. The temperature was maintained at 240°C for 5 hours to carry out a solid-state polymerization reaction, yielding polyester (A-4). The flow onset temperature of the obtained polyester (A-4) was 244°C. The obtained polyester (A-4) was evaluated in the same manner as in Example A-1. The results are shown in Table 1.

[0108] (Example A-5) The components added to the reactor were changed to 150.5 g (0.80 mol) of 2-hydroxy-6-naphthoic acid, 4.6 g (0.03 mol) of p-hydroxybenzoic acid, 77.6 g (0.42 mol) of 4,4'-dihydroxybiphenyl, 65.0 g (0.42 mol) of 2,5-furandicarboxylic acid, 195.7 g (1.92 mol) of acetic anhydride and 0.030 g of 1-methylimidazole. Otherwise, a powder of the solid components was obtained in the same manner as in Example A-1.

[0109] Next, the obtained powder was heated from room temperature to 220°C over 1 hour under a nitrogen atmosphere, then heated from 220°C to 250°C over 3 hours, and held at 250°C for 5 hours to carry out a solid-state polymerization reaction, yielding polyester (A-5). The flow onset temperature of the obtained polyester (A-5) was 301°C. The obtained polyester (A-5) was evaluated in the same manner as in Example A-1. The results are shown in Table 2.

[0110] (Example A-6) The components added to the reactor were changed to 508.1 g (2.70 mol) of 2-hydroxy-6-naphthoic acid, 732.0 g (5.30 mol) of p-hydroxybenzoic acid, 113.4 g (1.03 mol (0.03 mol in excess) of hydroquinone), 156.1 g (1.00 mol) of 2,5-furandicarboxylic acid, 1181.1 g (11.57 mol) of acetic anhydride, and 0.151 g of 1-methylimidazole. Otherwise, a powder of the solid components was obtained in the same manner as in Example A-1.

[0111] Next, the obtained powder was heated from room temperature to 190°C over 1 hour under a nitrogen atmosphere, and then from 190°C to 220°C over 3 hours. The temperature was maintained at 220°C for 5 hours to carry out a solid-state polymerization reaction, yielding polyester (A-6). The flow onset temperature of the obtained polyester (A-6) was 218°C. The obtained polyester (A-6) was evaluated in the same manner as in Example A-1. The results are shown in Table 2.

[0112] (Example A-7) The components added to the reactor were changed to 940.9 g (5.00 mol) of 2-hydroxy-6-naphthoic acid, 465.5 g (2.50 mol) of 4,4'-dihydroxybiphenyl, 216.2 g (1.00 mol) of 2,6-naphthoic acid, 234.1 g (1.50 mol) of 2,5-furandicarboxylic acid, 1174.0 g (11.50 mol) of acetic anhydride, and 0.186 g of 1-methylimidazole. Otherwise, a powder of solid components was obtained in the same manner as in Example A-1.

[0113] Next, the obtained powder was heated from room temperature to 210°C over 1 hour under a nitrogen atmosphere, and then from 210°C to 240°C over 3 hours. The temperature was maintained at 240°C for 5 hours to carry out a solid-state polymerization reaction, yielding polyester (A-7). The flow onset temperature of the obtained polyester (A-7) was 248°C. The obtained polyester (A-7) was evaluated in the same manner as in Example A-1. The results are shown in Table 2.

[0114] (Example A-8) The components added to the reactor were changed to 1035.0 g (5.50 mol) of 2-hydroxy-6-naphthoic acid, 255.2 g (2.32 mol (0.07 mol in excess) of hydroquinone), 367.5 g (1.70 mol) of 2,6-naphthoic acid, 7.8 g (0.05 mol) of 2,5-furandicarboxylic acid, 83.1 g (0.50 mol) of terephthalic acid, 1189.9 g (11.65 mol) of acetic anhydride, and 0.175 g of 1-methylimidazole. Otherwise, a powder of solid components was obtained in the same manner as in Example A-1.

[0115] Next, the obtained powder was heated from room temperature to 250°C over 1 hour under a nitrogen atmosphere, then heated from 250°C to 280°C over 3 hours, and held at 280°C for 5 hours to carry out a solid-state polymerization reaction, yielding polyester (A-8). The flow onset temperature of the obtained polyester (A-8) was 306°C. The obtained polyester (A-8) was evaluated in the same manner as in Example A-1. The results are shown in Table 2.

[0116] (Example A-9) The components added to the reactor were changed to 1035.0 g (5.50 mol) of 2-hydroxy-6-naphthoic acid, 255.2 g (2.32 mol (0.07 mol in excess) of hydroquinone), 335.1 g (1.55 mol) of 2,6-naphthoic acid, 31.2 g (0.20 mol) of 2,5-furandicarboxylic acid, 83.1 g (0.50 mol) of terephthalic acid, 1189.9 g (11.65 mol) of acetic anhydride, and 0.175 g of 1-methylimidazole. Otherwise, a powder of solid components was obtained in the same manner as in Example A-1.

[0117] Next, the obtained powder was heated from room temperature to 240°C over 1 hour under a nitrogen atmosphere, then heated from 240°C to 270°C over 3 hours, and held at 270°C for 5 hours to carry out a solid-state polymerization reaction, yielding polyester (A-9). The flow onset temperature of the obtained polyester (A-9) was 298°C. The obtained polyester (A-9) was evaluated in the same manner as in Example A-1. The results are shown in Table 2.

[0118] (Comparative Example B-1) The components added to the reactor were changed to 1035.0 g (5.50 mol) of 2-hydroxy-6-naphthoic acid, 255.2 g (2.32 mol (0.07 mol in excess) of hydroquinone), 83.1 g (0.5 mol) of terephthalic acid, 378.3 g (1.75 mol) of 2,6-naphthoic acid, 1189.9 g (11.66 mol) of acetic anhydride, and 0.175 g of 1-methylimidazole. Otherwise, a powder of solid components was obtained in the same manner as in Example A-1.

[0119] Next, the obtained powder was heated from room temperature to 260°C over 1 hour under a nitrogen atmosphere, then heated from 260°C to 280°C over 3 hours, and held at 280°C for 5 hours to carry out a solid-state polymerization reaction, yielding polyester (B-1). The flow onset temperature of the obtained polyester (B-1) was 317°C. The obtained polyester (B-1) was evaluated in the same manner as in Example A-1. The results are shown in Table 3.

[0120] (Comparative Example B-2) The components added to the reactor were changed to 1129.1 g (6.00 mol) of 2-hydroxy-6-naphthoic acid, 113.4 g (1.03 mol (0.03 mol in excess) of hydroquinone, 186.2 g (1.00 mol) of 4,4'-dihydroxybiphenyl, 432.4 g (2.00 mol) of 2,6-naphthoic acid, 1181.1 g (11.57 mol) of acetic anhydride, and 0.186 g of 1-methylimidazole. Otherwise, a powder of the solid components was obtained in the same manner as in Example A-1.

[0121] Next, the obtained powder was heated from room temperature to 240°C over 1 hour under a nitrogen atmosphere, then heated from 240°C to 270°C over 3 hours, and held at 270°C for 5 hours to carry out a solid-state polymerization reaction, yielding polyester (B-2). The flow initiation temperature of the obtained polyester (B-2) was 270°C. The obtained polyester (B-2) was evaluated in the same manner as in Example A-1. The results are shown in Table 3.

[0122] (Comparative Example B-3) The components added to the reactor were changed to 1129.1 g (6.00 mol) of 2-hydroxy-6-naphthoic acid, 113.4 g (1.03 mol (0.03 mol in excess) of hydroquinone, 186.2 g (1.00 mol) of 4,4'-dihydroxybiphenyl, 332.3 g (2.00 mol) of terephthalic acid, 1181.1 g (11.57 mol) of acetic anhydride, and 0.186 g of 1-methylimidazole. Otherwise, a powder of solid components was obtained in the same manner as in Example A-1.

[0123] Next, the obtained powder was heated from room temperature to 220°C over 1 hour under a nitrogen atmosphere, then heated from 220°C to 250°C over 3 hours, and held at 250°C for 5 hours to carry out a solid-state polymerization reaction, yielding polyester (B-3). The flow initiation temperature of the obtained polyester (B-3) was 250°C. The obtained polyester (B-3) was evaluated in the same manner as in Example A-1. The results are shown in Table 3.

[0124] (Comparative Example B-4) The components added to the reactor were changed to 903.3 g (4.80 mol) of 2-hydroxy-6-naphthoic acid, 27.6 g (0.20 mol) of p-hydroxybenzoic acid, 465.5 g (2.50 mol) of 4,4'-dihydroxybiphenyl, 415.3 g (2.50 mol) of terephthalic acid, 1174.0 g (11.50 mol) of acetic anhydride and 0.181 g of 1-methylimidazole. Otherwise, a powder of solid components was obtained in the same manner as in Example A-1.

[0125] Next, the obtained powder was heated from room temperature to 270°C over 1 hour under a nitrogen atmosphere, then heated from 270°C to 300°C over 3 hours, and held at 300°C for 5 hours to carry out a solid-state polymerization reaction, yielding polyester (B-4). The flow onset temperature of the obtained polyester (B-4) was 312°C. The obtained polyester (B-4) was evaluated in the same manner as in Example A-1. The results are shown in Table 4.

[0126] (Comparative Example B-5) The components added to the reactor were changed to 131.7 g (0.70 mol) of 2-hydroxy-6-naphthoic acid, 357.3 g (3.24 mol (0.09 mol in excess) of hydroquinone), 491.7 g (3.15 mol) of 2,5-furandicarboxylic acid, 844.0 g (8.27 mol) of acetic anhydride and 0.100 g of 1-methylimidazole. Otherwise, a powder of solid components was obtained in the same manner as in Example A-1.

[0127] Next, the obtained powder was heated from room temperature to 230°C in a nitrogen atmosphere for 1 hour, then from 230°C to 240°C in 3 hours, and held at 240°C for 5 hours to carry out a solid-state polymerization reaction, yielding polyester (B-5). The flow onset temperature of the obtained polyester (B-5) was 250°C. The obtained polyester (B-5) was evaluated in the same way as in Example A-1. However, polyester (B-5) was difficult to press-mold, therefore it was impossible to produce molded articles for evaluating dielectric properties, and thus the dielectric properties could not be evaluated. The results are shown in Table 4.

[0128] (Comparative Example B-6) The components added to the reactor were changed to 828.7 g (6.00 mol) of p-hydroxybenzoic acid, 372.4 g (2.00 mol) of 4,4'-dihydroxybiphenyl, 249.2 g (1.50 mol) of terephthalic acid, 83.1 g (0.50 mol) of isophthalic acid, 1174.0 g (11.5 mol) of acetic anhydride and 0.153 g of 1-methylimidazole. Otherwise, a powder of solid components was obtained in the same manner as in Example A-1.

[0129] Next, the obtained powder was heated from room temperature to 260°C over 1 hour under a nitrogen atmosphere, then heated from 260°C to 280°C over 3 hours, and held at 280°C for 5 hours to carry out a solid-state polymerization reaction, yielding polyester (B-6). The flow onset temperature of the obtained polyester (B-6) was 316°C. Polyester (B-6) underwent the same evaluation as in Example A-1. The results are shown in Table 4.

[0130] In Tables 1-4, "1-3-1" represents 2,5-furandicarboxylic acid, "1-1-2" represents 2-hydroxy-6-naphthoic acid, "1-3-2" represents 2,6-naphthoic acid, "1-1-3" represents p-hydroxybenzoic acid, "1-2-3-1" represents hydroquinone, "1-2-3-2" represents 4,4'-dihydroxybiphenyl, "1-3-3-1" represents terephthalic acid, and "1-3-3-2" represents isophthalic acid. The numerical values ​​for each component in Tables 1-4 represent the proportion (mol%) of each component relative to the total amount of monomers forming the polyester.

[0131]

Claims

1. A polyester comprising: The first monomer unit from the first monomer having a furan ring bonded with two carbonyl groups, and The second monomer unit has a fused aromatic ring. in, The content of the first monomer unit relative to the total content of all monomer units is more than 0.1 mol% and less than 40 mol%. The content of the second monomer unit relative to the total of all monomer units is 20 mol% or more.

2. The polyester according to claim 1, wherein, More than 90 mol% of the total number of monomer units are monomer units with aromatic rings.

3. The polyester according to claim 1, further comprising a third monomer unit having a benzene ring but not having a fused aromatic ring and a furan ring.

4. The polyester according to claim 3, wherein, The content of the third monomer unit is more than 10 mol% and less than 75 mol% relative to the total of all monomer units.

5. The polyester according to claim 1, wherein the 5% weight reduction temperature is above 450°C.

6. A molded article comprising the polyester according to any one of claims 1 to 5.

7. A method for manufacturing a molded article, comprising a step of molding a molding raw material containing the polyester according to any one of claims 1 to 5 to obtain a molded article.

8. The manufacturing method according to claim 7, wherein, The process described is the process of pressing and molding the raw material.

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