Aromatic polyester and method for producing same

Abstract

To provide an aromatic polyester having a plurality of operative functional groups and a method for producing the same.SOLUTION: An aromatic polyester comprises a polycarboxylic acid component and a polyhydric alcohol component as a copolymerization component, wherein the aromatic polyester comprises a polycarboxylic acid component having an operative functional group by 50 mol% or more when the total amount of the polycarboxylic acid component is taken as 100 mol%, and the aromatic polyester comprises an aromatic polyhydric alcohol component by 50 mol% or more when the total amount of the polyhydric alcohol component is taken as 100 mol%.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an aromatic polyester having a functional group, and more particularly to an aromatic polyester having a functional group that can be polymerized without causing gelation while retaining the functional group derived from a carboxylic acid component. [Background technology]

[0002] Copolymer polyester resins are widely used as raw materials for resin compositions used in paints, coatings, adhesives, etc. Copolymer polyester resins are generally composed of polycarboxylic acids and polyhydric alcohols. By selecting and combining the polycarboxylic acids and polyhydric alcohols, the molecular weight can be freely controlled, and the resulting copolymer polyester resins are used in a variety of applications, including paints and adhesives. In particular, aromatic polyesters are particularly useful industrially due to their excellent heat resistance and chemical resistance.

[0003] Among these, aromatic polyesters having branched functional groups (functional functional groups) that do not participate in polymerization, such as hydroxyl groups or carboxyl groups, are particularly useful industrially because they have good reactivity with curing agents, etc. For example, Patent Document 1 discloses a polyester resin containing a polymerizable double bond, and Patent Document 2 discloses an unsaturated polyester resin containing an itaconic acid ester unit as a reactive unsaturated site.

[0004] On the other hand, an example of synthesis of an aliphatic polyester having multiple functional groups using a rare earth triflate catalyst has been reported (Patent Document 3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-302779 [Patent Document 2] Special Publication No. 2012-521469 [Patent Document 3] Japanese Patent Application Laid-Open No. 2003-306535 Summary of the Invention [Problem to be solved by the invention]

[0006] However, although the polyester resin of Patent Document 1 has a polymerizable double bond as a functional group, it uses a large amount of a monomer without a functional group as a copolymerization component, resulting in a low concentration and thus not being of high industrial utility. It has also been found that increasing the concentration of polymerizable double bonds in the polyester resin can cause gelation due to isomerization or three-dimensional crosslinking during polymerization. Patent Document 2 describes a polyester resin obtained by polycondensation of at least one polyol with unsaturated carboxylic acids such as itaconic acid, citraconic acid, and / or mesaconic acid, but it does not have an aromatic skeleton and requires a radical inhibitor as an essential component to suppress isomerization and gelation during polymerization. Therefore, the polyester resin is not of high industrial utility and also causes impurities. Patent Document 3 investigates the polycondensation of aliphatic monomers having various functional groups (functional groups) other than those involved in polymerization, but does not investigate aromatic monomers. The reasons for this include the technical reason that, in the case of the direct polymerization method of dicarboxylic acid and diol, aromatic dicarboxylic acid with a melting point of 300°C or higher and diol are generally subjected to an esterification reaction at a high temperature (e.g., 200 to 240°C) above the boiling point of the diol, resulting in a large amount of energy consumption during polycondensation, and that terephthalic acid and isophthalic acid, which are commonly used as raw materials for aromatic polyesters, both have melting points of 300°C or higher and are sublimable crystals, making them difficult to handle.

[0007] An object of the present invention is to provide an aromatic polyester having a plurality of functional groups that do not participate in polymerization, which has been difficult to synthesize, and a method for synthesizing the same. [Means for solving the problem]

[0008] As a result of extensive research, the present inventors have found that the above problems can be solved by the following means, and have arrived at the present invention. That is, the present invention has the following configuration.

[0009] An aromatic polyester containing a polycarboxylic acid component and a polyhydric alcohol component as copolymerization components, wherein when the total polycarboxylic acid components are taken as 100 mol %, the aromatic polyester contains 50 mol % or more of a polycarboxylic acid component having a functional group, and when the total polyhydric alcohol components are taken as 100 mol %, the aromatic polyester contains 50 mol % or more of an aromatic polyhydric alcohol component.

[0010] The functional group is preferably at least one selected from the group consisting of a hydroxyl group, a thiol group, a carboxyl group, an aldehyde group, an azide group, a halogen, a disulfide group, a sulfonyl group, a sulfinyl group, and a methylidene group.

[0011] The aromatic polyester preferably contains a structural unit represented by the following formula (1). [ka] (In formula (1), X1, X2, Y1, and Y2 each independently represent hydrogen, an alkyl group, a hydroxyl group, a thiol group, a carboxyl group, an aldehyde group, an azide group, a halogen atom, oxygen, or a methylidene group. The Z1-X1 bond, the Z1-X2 bond, the Z2-Y1 bond, and the Z2-Y2 bond each independently represent a single bond or a double bond, and the Z1-Z2 bond is a single bond, a double bond, or an S-S bond. When X1, X2, Y1, and Y2 are all hydrogen or alkyl groups, the Z1-X1 bond, the Z1-X2 bond, the Z2-Y1 bond, and the Z2-Y2 bond are all single bonds, and the Z1-Z2 bond is a double bond. When the Z1-Z2 bond is an S-S bond, X1, X2, Y1, and Y2 each independently represent oxygen, or does not exist. When X1 is a methylidene group, the Z1-X1 bond is a double bond, X2 is absent, and the Z1-Z2 bond is a single bond. When X2 is a methylidene group, the Z1-X2 bond is a double bond, X1 is absent, and the Z1-Z2 bond is a single bond. When Y1 is a methylidene group, the Z2-Y1 bond is a double bond, Y2 is absent, and the Z1-Z2 bond is a single bond. When Y2 is a methylidene group, the Z2-Y2 bond is a double bond, Y1 is absent, and the Z1-Z2 bond is a single bond. A is a residue of an aromatic polyhydric alcohol. R1, R2, R3, and R4 each independently represent hydrogen or an alkyl group. m and n each independently represent an integer of 0 to 10, and p is an integer of 1 to 10.

[0012] The aromatic polyester preferably contains 500 mass ppm or more of fluorine and 250 mass ppm or more of sulfur, and preferably contains substantially no organic solvent. The aromatic polyester is preferably obtained by a low-temperature melt polycondensation method at 80 to 150°C.

[0013] An adhesive or paint containing the aromatic polyester. [Effects of the Invention]

[0014] The aromatic polyester of the present invention contains a predetermined amount of functional groups. Therefore, the functional groups are double bonds, and aromatic polyesters having double bonds in the main chain can serve as reaction sites for thiol-ene reactions and Michael addition reactions. Furthermore, aromatic polyesters having halogen functional groups in the main chain can serve as initiation sites for living radical polymerization, enabling various chemical modifications. DETAILED DESCRIPTION OF THE INVENTION

[0015] The aromatic polyester of the present invention is a resin that contains a polycarboxylic acid component and a polyhydric alcohol component as copolymerization components, and contains 50 mol % or more of a polycarboxylic acid component having a functional group when the total polycarboxylic acid components are taken as 100 mol %, and contains 50 mol % or more of an aromatic polyhydric alcohol component when the total polyhydric alcohol components are taken as 100 mol %.

[0016] The functional group is preferably a reactive functional group other than a functional group (dicarboxylic acid) involved in polymerization, and specifically, is preferably at least one selected from the group consisting of a hydroxyl group (-OH), a thiol group (-SH), a carboxyl group (-COH), an aldehyde group (-CHO), an azide group (-N), halogens (-F, -Cl, -Br, -I), a disulfide group (-SS-), a sulfinyl group (-S(=O)-), a sulfonyl group (-S(=O)-), and a methylidene group (=CH).

[0017] Examples of the polycarboxylic acid component having a functional group include an aromatic polycarboxylic acid having a functional group, an aliphatic polycarboxylic acid having a functional group, or an alicyclic polycarboxylic acid having a functional group, and preferably an aromatic dicarboxylic acid having a functional group, an aliphatic dicarboxylic acid having a functional group, or an alicyclic dicarboxylic acid having a functional group, and more preferably an aliphatic dicarboxylic acid having a functional group.

[0018] The polycarboxylic acid component having the functional group is not particularly limited, but examples thereof include maleic acid (unsaturated bond), fumaric acid (unsaturated bond), citraconic acid (unsaturated bond), itaconic acid (unsaturated bond), malic acid (OH), tartaric acid (OH), thiomalic acid (SH), bromosuccinic acid (Br), azidosuccinic acid (N3), 3,3-dithiodipropionic acid (SS), tricarboxylic acid (COOH), etc. One or more of these may be selected and used.

[0019] When the polycarboxylic acid component of the aromatic polyester is taken as 100 mol %, it is necessary that the polycarboxylic acid component having the functional group be contained in an amount of 50 mol % or more, preferably 60 mol % or more, more preferably 70 mol % or more, even more preferably 80 mol % or more, still more preferably 90 mol % or more, particularly preferably 95 mol % or more, and most preferably 99 mol % or more, and it may even be 100 mol %.

[0020] Furthermore, a polycarboxylic acid component other than the polycarboxylic acid component having a functional functional group can be used as a copolymerization component. The polycarboxylic acid component other than the polycarboxylic acid component having a functional functional group is preferably a polycarboxylic acid that does not contain a reactive functional group other than the functional group (dicarboxylic acid) involved in polymerization (hereinafter also referred to as a polycarboxylic acid component without a functional functional group). Examples of the polycarboxylic acid component without a functional functional group include the following alicyclic polycarboxylic acids, aliphatic polycarboxylic acids, and aromatic polycarboxylic acids. Examples of alicyclic polycarboxylic acids include alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,2-cyclohexanedicarboxylic acid and their acid anhydrides. Examples of aliphatic polycarboxylic acids include aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, dimer acid, 1,2,3-propanetricarboxylic acid, and 1,3,5-pentanetricarboxylic acid. Examples of aromatic polycarboxylic acids include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, biphenyldicarboxylic acid, diphenic acid, and 5-hydroxyisophthalic acid. Other examples include aromatic dicarboxylic acids having a sulfonic acid group or a sulfonate salt group, such as sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, 5-(4-sulfophenoxy)isophthalic acid, sulfoterephthalic acid, and / or their metal salts and ammonium salts. One or more of these may be selected and used.

[0021] The content of the polycarboxylic acid component not having the functional group is preferably 50 mol% or less, more preferably 40 mol% or less, even more preferably 30 mol% or less, still more preferably 20 mol% or less, even more preferably 10 mol% or less, particularly preferably 5 mol% or less, and most preferably 1 mol% or less, when the polycarboxylic acid component of the aromatic polyester is taken as 100 mol%. It may even be 0 mol%.

[0022] The aromatic polyhydric alcohol component used in the aromatic polyester of the present invention may or may not have the functional group (a reactive functional group other than the functional group (diol) involved in polymerization). An aromatic polyhydric alcohol component without a functional group is preferred, and an aromatic diol component without a functional group is more preferred. The aromatic diol without a functional group is not particularly limited, but is preferably an aromatic diol compound, a glycol-modified aromatic diol compound, or a glycol-modified aromatic dicarboxylic acid, and more preferably a glycol-modified aromatic diol compound or a glycol-modified aromatic dicarboxylic acid. Specific examples of the aromatic glycol compound include, but are not limited to, 1,2-phenylene glycol, 1,3-phenylene glycol, 1,4-phenylene glycol, naphthalenediol, bisphenol A, bisphenol F, etc. Specific examples of glycol-modified aromatic diol compounds include, but are not limited to, an ethylene oxide adduct of 1,2-phenylene glycol, a propylene oxide adduct of 1,2-phenylene glycol, an ethylene oxide adduct of 1,3-phenylene glycol, a propylene oxide adduct of 1,3-phenylene glycol, an ethylene oxide adduct of 1,4-phenylene glycol, a propylene oxide adduct of 1,4-phenylene glycol, an ethylene oxide adduct of naphthalene diol, a propylene oxide adduct of naphthalene diol, an ethylene oxide adduct of bisphenol A, a propylene oxide adduct of bisphenol A, an ethylene oxide adduct of bisphenol F, and a propylene oxide adduct of bisphenol F. Specific examples of glycol-modified aromatic dicarboxylic acids include, but are not limited to, ethylene glycol-modified terephthalic acid, propylene glycol-modified terephthalic acid, ethylene glycol-modified isophthalic acid, propylene glycol-modified isophthalic acid, ethylene glycol-modified orthophthalic acid, and propylene glycol-modified orthophthalic acid.Further examples of glycol-modified aromatic dicarboxylic acids include glycol-modified aromatic dicarboxylic acids having a sulfonic acid group or a sulfonate salt group, such as naphthalenedicarboxylic acid, biphenyldicarboxylic acid, diphenic acid, 5-hydroxyisophthalic acid, sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, 5-(4-sulfophenoxy)isophthalic acid, sulfoterephthalic acid, and / or their metal salts or ammonium salts. These can be used alone or in combination of two or more. Among these, glycols obtained by adding 1 to several moles of ethylene oxide or propylene oxide to two phenolic hydroxyl groups of bisphenols, such as an ethylene oxide adduct of 1,4-phenylene glycol, bisphenol A, an ethylene oxide adduct of bisphenol A (manufactured by Sanyo Chemical Industries, Ltd., Newpol (registered trademark) BPE-20T), and a propylene oxide adduct (manufactured by Sanyo Chemical Industries, Ltd., Newpol BP-5P), and BHET (ethylene glycol-modified terephthalic acid) can be more preferably used.

[0023] When the polyhydric alcohol component of the aromatic polyester is taken as 100 mol %, the aromatic diol component must be contained in an amount of 50 mol % or more, preferably 60 mol % or more, more preferably 70 mol % or more, even more preferably 80 mol % or more, still more preferably 90 mol % or more, particularly preferably 95 mol % or more, and most preferably 99 mol % or more, and may even be 100 mol %.

[0024] Furthermore, as polyhydric alcohol components other than the aromatic polyhydric alcohol component, the following aliphatic polyhydric alcohols, alicyclic polyhydric alcohols, ether bond-containing glycols, etc. can be used in combination.

[0025] Examples of aliphatic polyhydric alcohols include ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 2-ethyl-2-butylpropanediol, hydroxypivalic acid neopentyl glycol ester, dimethylolheptane, 2,2,4-trimethyl-1,3-pentanediol, and polycarbonate diol (manufactured by Asahi Kasei Corporation, Duranol (registered trademark)). Examples of alicyclic polyhydric alcohols include 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, tricyclodecanediol, tricyclodecanedimethylol, spiroglycol, hydrogenated bisphenol A, or ethylene oxide adducts and propylene oxide adducts of hydrogenated bisphenol A. Examples of glycols containing an ether bond include diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, neopentyl glycol ethylene oxide adduct, and neopentyl glycol propylene oxide adduct. One or more of these can be selected and used.

[0026] Furthermore, as polyhydric alcohol components other than the aromatic polyhydric alcohol components, divalent or higher alicyclic polycarboxylic acid components or polyhydric alcohol components in which both terminals of an aliphatic polycarboxylic acid component are modified with glycol can also be used. Examples of alicyclic polycarboxylic acids include alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,2-cyclohexanedicarboxylic acid and their acid anhydrides. Examples of aliphatic polycarboxylic acids include aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, and dimer acid.

[0027] The content of the aliphatic polyhydric alcohol, alicyclic polyhydric alcohol, and ether bond-containing glycol component is preferably 50 mol% or less, more preferably 40 mol% or less, even more preferably 30 mol% or less, still more preferably 10 mol% or less, even more preferably 10 mol% or less, particularly preferably 5 mol% or less, and most preferably 1 mol% or less, and may even be 0 mol%, when the polyhydric alcohol component of the aromatic polyester is taken as 100 mol%.

[0028] The aromatic polyester of the present invention preferably has a structural unit represented by the following formula (1). [ka] In formula (1), X1, X2, Y1, and Y2 each independently represent hydrogen (-H), an alkyl group, a hydroxyl group (-OH), a thiol group (-SH), a carboxyl group (-CO2H), an aldehyde group (-CHO), an azide group (-N3), a halogen (-F, -Cl, -Br, -I), oxygen (=O), or a methylidene group (=CH2). The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and even more preferably 1 to 3 carbon atoms. The alkyl group may be either linear or branched. The halogen may be fluorine, chlorine, bromine, or iodine, with bromine being preferred. The Z1-X1 bond, the Z1-X2 bond, the Z2-Y1 bond and the Z2-Y2 bond are each independently a single bond or a double bond, and the Z1-Z2 bond is a single bond, a double bond or an S-S bond. When X1, X2, Y1, and Y2 are all hydrogen or alkyl groups, the Z1-X1 bond, Z1-X2 bond, Z2-Y1 bond, and Z2-Y2 bond are all single bonds, and the Z1-Z2 bond is a double bond. When the Z1-Z2 bond is an S-S bond, X1, X2, Y1, and Y2 are each independently oxygen (-S(=0)-S-, -S(=0)-S(=0)-, -S(=0)-S-, -S(=0)-S(=0)-, or -S(=0)-S(=0)-) or absent (-S-S-). Absent (-S-S-) is preferred. When X1 is a methylidene group, the Z1-X1 bond is a double bond, X2 is absent, and the Z1-Z2 bond is a single bond. When X2 is a methylidene group, the Z1-X2 bond is a double bond, X1 is absent, and the Z1-Z2 bond is a single bond. When Y1 is a methylidene group, the Z2-Y1 bond is a double bond, Y2 is absent, and the Z1-Z2 bond is a single bond. When Y2 is a methylidene group, the Z2-Y2 bond is a double bond, Y1 is absent, and the Z1-Z2 bond is a single bond. R1, R2, R3 and R4 are each independently hydrogen or an alkyl group, and m and n are each independently an integer of 0 to 10, preferably an integer of 1 to 5, and more preferably an integer of 1 to 3.

[0029] In formula (1), A is a residue of an aromatic polyhydric alcohol, preferably a residue of an aromatic diol. The aromatic polyhydric alcohol is not particularly limited, but is preferably an aromatic diol compound, a glycol-modified aromatic diol compound, or a glycol-modified aromatic dicarboxylic acid, and more preferably a glycol-modified aromatic diol compound or a glycol-modified aromatic dicarboxylic acid. Specific examples of the aromatic glycol compound are not particularly limited, but include 1,2-phenylene glycol, 1,3-phenylene glycol, 1,4-phenylene glycol, naphthalenediol, bisphenol A, bisphenol F, etc. Specific examples of glycol-modified aromatic diol compounds include, but are not limited to, an ethylene oxide adduct of 1,2-phenylene glycol, a propylene oxide adduct of 1,2-phenylene glycol, an ethylene oxide adduct of 1,3-phenylene glycol, a propylene oxide adduct of 1,3-phenylene glycol, an ethylene oxide adduct of 1,4-phenylene glycol, a propylene oxide adduct of 1,4-phenylene glycol, an ethylene oxide adduct of naphthalene diol, a propylene oxide adduct of naphthalene diol, an ethylene oxide adduct of bisphenol A, a propylene oxide adduct of bisphenol A, an ethylene oxide adduct of bisphenol F, and a propylene oxide adduct of bisphenol F. Specific examples of glycol-modified aromatic dicarboxylic acids include, but are not limited to, ethylene glycol-modified terephthalic acid, propylene glycol-modified terephthalic acid, ethylene glycol-modified isophthalic acid, propylene glycol-modified isophthalic acid, ethylene glycol-modified orthophthalic acid, and propylene glycol-modified orthophthalic acid. These may be used alone or in combination of two or more. Of these, an ethylene oxide adduct of bisphenol A, a propylene oxide adduct of bisphenol A, or an ethylene glycol-modified terephthalic acid is preferred. p is an integer of 1 to 10, preferably an integer of 1 to 5, and more preferably an integer of 1 to 3.

[0030] When all structural units of the aromatic polyester are taken as 100 mol %, the aromatic polyester of the present invention preferably contains structural units of formula (1) in an amount of 50 mol % or more, more preferably 60 mol % or more, even more preferably 70 mol % or more, still more preferably 80 mol % or more, particularly preferably 90 mol % or more, particularly preferably 95 mol % or more, and most preferably 99 mol % or more, and may even be 100 mol %.

[0031] Preferred structures of the formula (1) include the following formulas (2) to (5). [ka] In formula (2), X1, X2, Y1, and Y2 are preferably each independently hydrogen, an alkyl group, a hydroxyl group, a thiol group, a carboxyl group, an aldehyde group, an azide group, or a halogen. However, not all of X1, X2, Y1, and Y2 are hydrogen or an alkyl group. More preferably, X1 and / or Y1 are a hydroxyl group, a thiol group, a carboxyl group, an aldehyde group, an azide group, or a halogen, and even more preferably, X1 is a hydroxyl group, a thiol group, a carboxyl group, an aldehyde group, an azide group, or a halogen, and Y1 is hydrogen. The structure of formula (2) enables various chemical modifications, such as serving as an initiation point for living radical polymerization.

[0032] [ka] In formula (3), X1 and Y1 are preferably each independently a methylidene group. More preferably, one of X1 or Y1 is a methylidene group and the other is hydrogen, and even more preferably, X1 is a methylidene group and Y1 is hydrogen.

[0033] [ka] In formula (4), X1 and Y1 are each preferably independently hydrogen or an alkyl group, more preferably hydrogen. When X1 and / or Y1 are an alkyl group, the alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and even more preferably 1 to 3 carbon atoms. The alkyl group may be either linear or branched. Having the structure of formula (4) enables various chemical modifications, such as serving as a reaction site for thiol-ene reaction or Michael addition reaction.

[0034] [ka] In formula (5), it is preferable that X1, X2, Y1, and Y2 are each independently absent (disulfide bond) or oxygen (=O). It is more preferable that all of X1, X2, Y1, and Y2 are absent (disulfide bond).

[0035] In the formulas (2) to (5), R1, R2, R3, and R4 are each independently preferably hydrogen or an alkyl group, more preferably hydrogen. When R1 to R4 are each independently an alkyl group, it is preferable that the number of carbon atoms therein is 1 to 10, more preferably 1 to 5, and even more preferably 1 to 3. The alkyl group may be linear or branched. m and n are each independently an integer of 0 to 10, preferably an integer of 1 to 5, and even more preferably an integer of 1 to 3. In particular, in the formulas (2) and (3), it is preferable that m is 0 and n is 1. In the formula (4), it is preferable that both m and n are 0. In the formula (5), it is preferable that both m and n are 2. In all of the formulas (2) to (5), p is preferably an integer of 1 to 10, more preferably an integer of 1 to 5, and even more preferably an integer of 1 to 3.

[0036] Preferred specific examples of formula (1) include, but are not limited to, the following structures: [ka]

[0037] [ka]

[0038] [ka]

[0039] The aromatic polyester of the present invention preferably contains 500 ppm by mass or more of fluorine. Since the polyester tends to exhibit water repellency and oil-repellent properties, the fluorine content is more preferably 1000 ppm by mass or more, and even more preferably 2000 ppm by mass or more. Furthermore, since the polyester has good heat resistance and chemical resistance, the fluorine content is preferably 10000 ppm by mass or less, more preferably 8000 ppm by mass or less, and even more preferably 5000 ppm by mass or less.

[0040] The aromatic polyester of the present invention preferably contains 250 ppm by mass or more of sulfur. Since the melting point tends to be high, the sulfur content is more preferably 500 ppm by mass or more, and even more preferably 1000 ppm by mass or more. Furthermore, since the heat resistance and chemical resistance are improved, the sulfur content is preferably 5000 ppm by mass or less, more preferably 4000 ppm by mass or less, and even more preferably 3000 ppm by mass or less.

[0041] The aromatic polyester of the present invention preferably contains substantially no organic solvent. By containing substantially no organic solvent, adhesives and coatings that are excellent for the human body and the environment can be produced. "Substantially containing no organic solvent" preferably means that the organic solvent is contained in an amount of 5% by mass or less, more preferably 2% by mass or less, even more preferably 1% by mass or less, and particularly preferably 0% by mass, based on 100% by mass of the aromatic polyester.

[0042] Examples of the organic solvent include aromatic hydrocarbons such as benzene, toluene, and xylene; aliphatic hydrocarbons such as hexane, heptane, and octane; ketone solvents such as acetone and methyl ethyl ketone; ester solvents such as ethyl acetate and propyl acetate; ether solvents such as dimethyl ether and diethyl ether; and aprotic solvents such as N-methylpyrrolidone (NMP) and N,N-dimethylformamide (DMF).

[0043] The number-average molecular weight of the aromatic polyester of the present invention is preferably 2,000 to 30,000, more preferably 3,000 to 25,000, and even more preferably 4,000 to 20,000. By setting the number-average molecular weight to the above-mentioned lower limit or more, the coating film becomes strong and the coating film properties during processing become good. Furthermore, by setting the number-average molecular weight to the above-mentioned upper limit or less, the melt viscosity during polycondensation is prevented from becoming too high, and the polyester can be easily removed from the reaction vessel (flask).

[0044] The aromatic component of the aromatic polyester of the present invention is derived from an aromatic polyhydric alcohol component. Generally, aromatic-containing monomers have a high melting point of 200 to 300°C, so when polymerizing a polyester, the reaction must be carried out at a temperature above the melting point. They melt at temperatures below 150°C, making it difficult to homogenize them. However, by modifying both ends of an aromatic carboxylic acid with a glycol component, the melting point is lowered, enabling low-temperature polymerization. For example, the melting point of terephthalic acid, a raw material for PET, is 300°C, but BHET (bis-2-hydroxyethyl terephthalate), in which both ends are modified with ethylene glycol, has a melting point of 110°C, making polycondensation possible at temperatures below 150°C.

[0045] In addition to BHET, bisphenol-ethylene glycol 2-mol adduct and propylene glycol 5-mol adduct are also available, in which both ends of the bisphenol are modified with glycol components, lowering the melting point and enabling low-temperature polymerization.

[0046] Furthermore, the use of a triflate catalyst (trifluoromethanesulfonate catalyst) enables the esterification reaction at a low temperature of approximately 80 to 150°C. Conventionally, when a monomer having a functional group other than the functional group involved in the polymerization (such as a hydroxyl group, a thiol group, a carboxyl group, an aldehyde group, an azide group, a halogen, or a methylidene group) was used, the high-temperature reaction caused side reactions such as hydrolysis (solvolysis) and elimination of these functional groups, making it difficult to obtain an aromatic polyester. In contrast, the present invention enables a low-temperature reaction, and even when a monomer having a functional group other than the functional group involved in the polymerization (a functional functional group) is used, no side reactions occur, resulting in the production of an aromatic polyester. In other words, aromatic polyesters can be obtained by a low-temperature melt polycondensation method at approximately 80 to 150°C.

[0047] Examples of triflate catalysts include rare earth triflate catalysts. Specific examples of rare earth metals used in rare earth triflate catalysts include scandium (Sc) and yttrium (Y). Lanthanoid elements such as lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu) are effective. The rare earth metals can be used alone or in combination. Among these, scandium is preferred. As the triflate catalyst other than the rare earth metals, specifically, those containing copper (Cu), zinc (Zn), tin (Sn), hafnium (Hf), bismuth (Bi), etc. are effective. An example of the triflate is X(OSO2CF3). Here, X is a rare earth or other element, and among these, X is preferably scandium (Sc).

[0048] Aromatic polyesters can be polymerized at low temperatures (low-temperature melt polycondensation). Specifically, a temperature of 150°C or lower is preferred. Since side reactions of functional groups (functional functional groups) other than those involved in the polymerization can be suppressed, the temperature is more preferably 140°C or lower, even more preferably 130°C or lower, even more preferably 120°C or lower, and particularly preferably 110°C or lower. There is no particular lower limit, but a temperature of 60°C or higher is preferred. Furthermore, since the reaction time can be shortened, the temperature is more preferably 70°C or higher, even more preferably 80°C or higher, and particularly preferably 90°C or higher.

[0049] The aromatic polyester can be polymerized substantially without using an organic solvent. Substantially no organic solvent means that the amount of organic solvent used is preferably 5 parts by mass or less, more preferably 2 parts by mass or less, even more preferably 1 part by mass or less, and particularly preferably 0 part by mass, per 100 parts by mass of the resulting aromatic polyester. Substantially no organic solvent used not only improves the volumetric efficiency of the reaction, but also allows the production of a resin that is good for the human body and the environment.

[0050] The aromatic polyester can be polymerized substantially without using a radical inhibitor. Substantially no radical inhibitor means that the amount of radical inhibitor used is preferably 5 parts by mass or less, more preferably 2 parts by mass or less, even more preferably 1 part by mass or less, and particularly preferably 0 part by mass, per 100 parts by mass of the resulting aromatic polyester. Substantially no radical inhibitor is used, allowing the aromatic polyester to be produced efficiently and free from impurities derived from the radical inhibitor. Examples of radical inhibitors include hydroquinone, 2-methylhydroquinone, benzoquinone, and 2-methylbenzoquinone.

[0051] The reaction time can be appropriately set depending on the types of monomers (polycarboxylic acid component and aromatic diol component), the type of catalyst, the reaction temperature, etc. Specifically, the reaction time is preferably 1 to 20 hours, more preferably 2 to 15 hours, and even more preferably 3 to 12 hours.

[0052] The aromatic polyester of the present invention can be used in adhesives or coating materials. The aromatic polyester is preferably contained in the adhesive or coating material in an amount of 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, calculated as solid content. The amount is preferably 95% by mass or less, more preferably 90% by mass or less. [Example]

[0053] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the following examples, and it is possible to carry out the present invention by making appropriate modifications within the scope that is compatible with the spirit of the present invention, and all such modifications are included in the technical scope of the present invention.

[0054] In the following description, unless otherwise specified, "parts" refers to "parts by mass." The measurement and evaluation methods used in this specification are as follows.

[0055] <Resin composition> The aromatic polyester was dissolved in deuterated chloroform and analyzed using a VARIAN 400-MR NMR apparatus. 1 H-NMR analysis was carried out, and the molar ratio was determined from the ratio of the integral values.

[0056] <Number average molecular weight (Mn)> The aromatic polyester sample was dissolved in N,N-dimethylformamide to a resin concentration of approximately 0.5% by mass and filtered through a 0.5 μm pore size polytetrafluoroethylene membrane filter to prepare the measurement sample. The molecular weight was measured by gel permeation chromatography (GPC) using N,N-dimethylformamide as the mobile phase and a differential refractometer as the detector. The flow rate was 1 mL / min and the column temperature was 30°C. Showa Denko KF-802, 804L, and 806L columns were used. Monodisperse polystyrene was used as the molecular weight standard. The number average molecular weight was calculated by excluding the portion corresponding to a molecular weight less than 1000.

[0057] <Elemental analysis (fluorine, sulfur content)> <Pretreatment and measurement methods> A 20 mg sample (aromatic polyester) was placed in a magnetic boat and combusted in a quartz tube furnace (Mitsubishi Chemical Analytech AQF-2100H). The combustion gas was absorbed with 0.3% by mass of hydrogen peroxide. Fluoride ions and sulfate ions in the absorbed solution were then measured using an ion chromatograph (Thermo Fisher Scientific ICS-1600). <Automatic combustion furnace conditions> Equipment: Mitsubishi Chemical Analytech automatic combustion furnace AQF-2100H Sample decomposition temperature: 1000℃ Burning program: 15 minutes Absorption liquid composition: 0.3 mass% hydrogen peroxide aqueous solution <Ion chromatography analysis conditions> Equipment: Thermo Fisher ion chromatograph ICS-1600 Column: Anion exchange column AS12A Eluent composition: Sodium carbonate / sodium bicarbonate mixed aqueous solution Separation program: 15 minutes Detector: Electrical conductivity detector

[0058] <Organic solvent content> Approximately 0.5 g of sample (aromatic polyester) is weighed onto an aluminum dish (this is designated as A). The sample is then placed in a dryer at 150°C and dried under a reduced pressure of 5 mmHg or less for 2 hours. After drying is complete, the sample is cooled to room temperature and removed (this is designated as B). The organic solvent content is calculated using the following formula: Formula: Organic solvent content (mass%) = (AB) / A x 100

[0059] Example 1 No.1 aromatic polyester manufacturer A 50 ml glass flask equipped with a stirrer was charged with 100 mol% bis-2-hydroxyethyl terephthalate (BHET), 100 mol% maleic acid, and 1.0 mol% scandium triflate, and the mixture was homogenized at 100°C. After dissolving the raw materials, the pressure in the system was gradually reduced to 5 mmHg over 30 minutes, and then the polycondensation reaction was carried out at 110°C for 4 hours under a vacuum of 0.3 mmHg or less. The contents were then removed and cooled. The composition, number average molecular weight, etc. of the resulting aromatic polyester No. 1 are shown in Table 1.

[0060] Examples 2 to 11, Comparative Examples 1 to 3 Production of aromatic polyesters No. 2 to 14 Aromatic polyesters Nos. 2 to 14 were synthesized in the same manner as aromatic polyester No. 1, except that the raw materials used and their ratios were changed, and they were evaluated in the same manner as aromatic polyester No. 1. The evaluation results are shown in Tables 1 and 2. In Example 7, 50 mol% each of Duranol-T5650E (a polycarbonate diol manufactured by Asahi Kasei Chemicals Corporation: a mixture of 1,5-pentanediol and 1,6-hexanediol, number average molecular weight approximately 500) and adipic acid were used as the polyhydric alcohol component, and in Example 11, 50 mol% of 1,5-pentanediol was used as the polyhydric alcohol component.

[0061] [Table 1]

[0062] [Table 2]

[0063] No.3 In the system using the propylene oxide adduct of bisphenol A (BP-5P) as the polyhydric alcohol component, the secondary OH groups involved in the reaction have a slower reaction rate than the other primary OH groups. Therefore, even though the reaction time was long at 11.5 hours, the molecular weight did not increase significantly, even though the system had the structure of formula (1).

[0064] No. 5: When the same raw materials as in No. 4 were used but the catalyst amount was reduced from 1.0 mol% to 0.5 mol%, an aromatic polyester having the structure of formula (1) was obtained. However, the reaction time required to obtain a polymer of the same molecular weight was 4 hours.

[0065] No. 6: When the same raw materials as in No. 4 were used but the catalyst amount was reduced from 1.0 mol% to 0.2 mol%, an aromatic polyester having the structure of formula (1) was obtained. However, the reaction time required to obtain a polymer of the same molecular weight was 6 hours.

[0066] No. 12 When a similar reaction was carried out without a catalyst, the esterification reaction did not proceed and the molecular weight did not increase, so a polyester having the structure of formula (1) could not be obtained.

[0067] When a general transesterification catalyst such as No. 13 Al catalyst was used, the esterification reaction did not proceed and the molecular weight did not increase. An aromatic polyester having the structure of formula (1) was not obtained.

[0068] No.14 When thiomalic acid was used as the dicarboxylic acid component, gelation occurred when the reaction was carried out at high temperatures for a long time, and therefore, aromatic polyesters having the structure of formula (1) could not be obtained. This is thought to be due to intermolecular coupling between branched SH groups in the polyester molecules produced by melt polycondensation, resulting in the formation of three-dimensional crosslinks. [Industrial Applicability]

[0069] The aromatic polyester of the present invention has specific structural units. Furthermore, by using a specific polycarboxylic acid component and an aromatic diol component, it can be synthesized by dehydration polycondensation under mild conditions without using a solvent. This method allows for the synthesis of polyesters having double bonds in the main chain and its side chains, as well as polyesters having functional groups other than the condensation functional group. Polyesters having double bonds in the main chain can serve as reaction sites for thiol-ene reactions and Michael addition reactions. Polyesters having halogens in the side chains can serve as initiation sites for living radical polymerization, enabling various chemical modifications. Polyesters having mercapto groups in the side chains can serve as reaction sites for Michael addition reactions, making them extremely useful polymers.

Claims

1. An aromatic polyester containing a polycarboxylic acid component and a polyhydric alcohol component as copolymerization components and having a number average molecular weight of 2,000 or more and 30,000 or less, the aromatic polyester comprises a triflate catalyst-derived product; When the total amount of all polycarboxylic acid components is taken as 100 mol %, the composition contains 50 mol % or more of an aliphatic polycarboxylic acid component or an alicyclic polycarboxylic acid component having two carboxyl groups and one or more functional groups selected from the group consisting of a hydroxyl group, a thiol group, a carboxyl group, an aldehyde group, an azide group, a halogen, a disulfide group, a sulfonyl group, a sulfinyl group, and a methylidene group, When the total amount of polyhydric alcohol components is 100 mol %, the aromatic polyhydric alcohol component is contained in an amount of 50 mol % or more, The aromatic polyester is characterized in that the aromatic polyhydric alcohol component is one or more aromatic diol compounds selected from the group consisting of 1,2-phenylene glycol, 1,3-phenylene glycol, 1,4-phenylene glycol, naphthalenediol, bisphenol A, and bisphenol F, a glycol-modified product of the aromatic diol compound, or a glycol-modified product of an aromatic dicarboxylic acid.

2. The aromatic polyester according to claim 1 , wherein the aromatic component of the aromatic polyester is derived from the aromatic polyhydric alcohol component.

3. 3. The aromatic polyester according to claim 1, which contains a structural unit represented by the following formula (1): 【Chemistry 1】 (In formula (1), X １ , X ２ , Y １ and Y ２ are each independently hydrogen, an alkyl group, a hydroxyl group, a thiol group, a carboxyl group, an aldehyde group, an azide group, a halogen atom, oxygen, or a methylidene group. Z １ -X １ join, Z １ -X ２ join, Z ２ -Y １ Bond and Z ２ -Y ２ each bond is independently a single bond or a double bond; Z １ -Z ２ The bond is a carbon-carbon single bond or an S—S bond. Z １ -Z ２ When the bond is an S-S bond, X １ , X ２ , Y １ and Y ２ are each independently oxygen or absent. X １ When is a methylidene group, Z １ -X １ The bond is a double bond, and X ２ does not exist, and Z １ -Z ２ The bond is a carbon-carbon single bond. X ２ When is a methylidene group, Z １ -X ２ The bond is a double bond, and X １ does not exist, and Z １ -Z ２ The bond is a carbon-carbon single bond. Y １ When is a methylidene group, Z ２ -Y １ The bond is a double bond, and Y ２ does not exist, and Z １ -Z ２ The bond is a carbon-carbon single bond. Y ２ When is a methylidene group, Z ２ -Y ２ The bond is a double bond, and Y １ does not exist, and Z １ -Z ２ The bond is a carbon-carbon single bond. A is the residue of an aromatic polyhydric alcohol. R １ , R ２ , R ３ and R ４ are each independently hydrogen or an alkyl group. m and n each independently represent an integer of 0 to 10, and p represents an integer of 1 to 10.

4. 4. The aromatic polyester according to claim 1, wherein the halogen is —Cl, —Br, or —I.

5. 5. The aromatic polyester according to claim 1, which contains 500 ppm by mass or more of fluorine and 250 ppm by mass or more of sulfur.

6. 6. The aromatic polyester according to claim 1, wherein the organic solvent is contained in an amount of 5% by mass or less based on 100% by mass of the aromatic polyester.

7. A method for producing the aromatic polyester according to any one of claims 1 to 6, comprising a low-temperature melt polycondensation step at 80 to 150°C.

8. An adhesive comprising the aromatic polyester according to any one of claims 1 to 6.

9. A paint containing the aromatic polyester according to any one of claims 1 to 6.

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