Crosslinked aromatic polyester resin composition and method for producing the same

Abstract

Provided is a crosslinked aromatic polyester resin composition which has high strength at room temperature due to "dynamic" covalent bond crosslinking capable of bonding exchange at a high temperature, and with which reprocessing and adhesion between films can be performed at a bonding exchange activating temperature or higher.　This crosslinked aromatic polyester resin composition contains a crosslinked aromatic polyester resin (C) and a transesterification catalyst (D) and satisfies the following (1)-(2). (1) The crosslinked aromatic polyester resin (C) is a reaction product of an epoxy compound (B) and an aromatic polyester resin (A) containing a carboxy group in a side chain. (2) When the crosslinked aromatic polyester resin composition is measured by infrared spectroscopy, the ratio (A3200-3600 / A1730) of the absorbance (A3200-3600) of a peak derived from a hydroxyl group in a wave number of about 3,200-3,600 cm-1 to the absorbance (A1730) of a peak derived from an ester bond in a wave number of about 1,730 cm-1 is 0.005-0.038.

Description

[Technical Field]

[0001] The present invention relates to a crosslinked aromatic polyester resin composition that exhibits self-adhesiveness, remoldability, and self-repairability under high-temperature conditions, and a method for producing the same. More specifically, the present invention relates to an aromatic polyester composition that has a stable crosslinked polymer network at room temperature and exhibits activated intermolecular bond exchange reactions at high temperatures, resulting in sample softening. [Background technology]

[0002] Crosslinked polyesters, obtained by curing aromatic polyesters with carboxyl groups in their side chains and epoxy compounds, have traditionally been used in adhesives and paints. However, due to the irreversibility of the covalent crosslinking points, they lack adhesion, reshapeability, and repairability. On the other hand, films incorporating dynamic bond exchange crosslinks can bond films together without adhesives, suppressing the leaching of foreign matter and residual solvents caused by adhesives, making them highly safe. Furthermore, aromatic polyesters are particularly useful industrially due to their excellent heat and chemical resistance.

[0003] A crosslinked polyester resin has been reported that can be obtained by mixing an aliphatic polyester having a carboxy group on the side chain, an aliphatic diepoxy having epoxy groups on both ends, and zinc acetate, and then heating the mixture to crosslink the mixture (Patent Document 1).

[0004] A resin composition has been reported that can be obtained by mixing a thermoplastic resin containing a hydroxy group, a thermoplastic resin containing an ester bond, and an ester exchange catalyst, and heating the mixture to crosslink the mixture (Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] WO2020 / 045439 [Patent Document 2] Japanese Patent Publication No. 2020-23591 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the crosslinked polyester resins described in Patent Document 1 are based on aliphatic polyesters containing carboxyl groups in the molecule, but not on aromatic polyesters. Patent Document 1 describes a method for synthesizing a polyester precursor containing thiol groups in the side chains by melt polycondensation of a diol component with thiomalic acid, a dicarboxylic acid containing thiol groups in the side chains, and then subjecting the precursor to a Michael addition reaction with acrylic acid to obtain a polyester resin containing carboxyl groups in the side chains. However, direct polymerization of dicarboxylic acids and diols typically involves esterification of aromatic dicarboxylic acids with melting points of 300°C or higher with diols at temperatures above the boiling point of the diol (e.g., 200-240°C), which consumes a lot of energy during polycondensation. Furthermore, terephthalic acid and isophthalic acid, which are commonly used as raw materials for aromatic polyesters, both have melting points above 300°C and are difficult to handle due to their sublimable crystal structure. Furthermore, in Patent Document 2, resin powders of a thermoplastic resin containing a hydroxy group and a thermoplastic resin containing an ester bond are prepared, mixed with an ester exchange catalyst, and then flat plates are produced using an injection molding machine. However, this method is essentially only achieved with acrylic resin, which has the problem of low heat resistance.

[0007] The present invention aims to provide a crosslinked aromatic polyester resin composition that uses an aromatic polyester as a base polymer and exhibits high strength at room temperature due to "dynamic" covalent crosslinking that enables bond exchange at high temperatures, and that enables reprocessing, film-to-film adhesion, and self-repair at or above the bond exchange activation temperature, something that has been difficult to achieve until now. The present invention also aims to provide a crosslinked aromatic polyester resin composition that exhibits excellent heat resistance due to the inclusion of an aromatic component. [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. A crosslinked aromatic polyester resin composition comprising a crosslinked aromatic polyester resin (C) and a transesterification catalyst (D), and satisfying the following (1) and (2): (1) The crosslinked aromatic polyester resin (C) is a reaction product of an aromatic polyester resin (A) containing a carboxy group in the side chain and an epoxy compound (B). (2) When the crosslinked aromatic polyester resin composition is measured by infrared spectroscopy, the wave number of 1730 cm originating from the ester bond is -1 The absorbance (A 1730 ) for the hydroxyl group-derived wavenumber of 3200-3600 cm -1 The absorbance (A 3200-3600 ) ratio (A 3200-3600 / A 1730 ) is greater than or equal to 0.005 and less than or equal to 0.038. The aromatic polyester resin (A) containing a carboxy group in the side chain preferably has an acid value of 5 mgKOH / g or more and 120 mgKOH / g or less, and a number average molecular weight of 8,000 or more. The molar ratio of the carboxy groups of the aromatic polyester resin (A) containing a carboxy group in a side chain to the epoxy groups of the epoxy compound (B) (carboxy groups:epoxy groups) is preferably 100:50 to 100:150. The epoxy compound (B) preferably has a number average molecular weight of 100 or more and 500 or less. The molar ratio of the transesterification catalyst (D) to the carboxy groups of the aromatic polyester resin (A) containing carboxy groups in its side chains (carboxy groups:transesterification catalyst) is preferably 100:10 to 100:40. A method for producing a crosslinked aromatic polyester resin composition, comprising the steps of mixing an aromatic polyester resin (A) having an acid value of 5 mgKOH / g or more and 120 mgKOH / g or less and containing a carboxy group in a side chain, an epoxy compound (B), and an ester exchange catalyst (D), and heating the mixture to crosslink the mixture. A self-adhesive, self-repairing material, or molding material containing the crosslinked aromatic polyester resin composition. [Effects of the Invention]

[0009] The crosslinked aromatic polyester resin composition of the present invention has high strength at room temperature due to "dynamic" covalent crosslinking that allows bond exchange at high temperatures, and is reprocessable and allows film-to-film adhesion above the bond exchange activation temperature. Furthermore, the remoldability of the crosslinked aromatic polyester resin composition allows it to be molded and thinned after the crosslinking reaction, and its self-healing ability allows it to repair scratches, making it suitable for semi-permanent use. DETAILED DESCRIPTION OF THE INVENTION

[0010] The crosslinked aromatic polyester resin composition is a resin composition containing a crosslinked aromatic polyester resin (C) which is a reaction product of an aromatic polyester resin (A) containing a carboxy group in the side chain (hereinafter simply referred to as "aromatic polyester resin (A) containing a carboxy group in the side chain" or "polyester resin (A)") and an epoxy compound (B), and a transesterification catalyst (D).

[0011] <Aromatic polyester resin (A) containing a carboxy group in the side chain> The aromatic polyester resin (A) containing a carboxy group in a side chain is a resin having a carboxy group in a side chain of an aromatic polyester resin. Here, the side chain may be a structure in which a carboxy group is present in a substituent (e.g., an aliphatic hydrocarbon group, an aromatic hydrocarbon group, an alicyclic hydrocarbon group, etc.) branched from the main chain of the aromatic polyester resin, or a structure in which a carboxy group is present directly in the aromatic polyester resin. A structure in which a carboxy group is present directly in the aromatic polyester resin is preferred.

[0012] The acid value of the polyester resin (A) is preferably 5 mgKOH / g or more. Since sufficient crosslinking is achieved and heat resistance is improved, it is more preferably 10 mgKOH / g or more, and even more preferably 15 mgKOH / g or more. Furthermore, the acid value is preferably 120 mgKOH / g or less. Since excessive crosslinking density can be prevented, and the coating film obtained from the crosslinked aromatic polyester resin composition can be prevented from becoming too hard, it is more preferably 110 mgKOH / g or less, and even more preferably 100 mgKOH / g or less.

[0013] The polyester resin (A) preferably contains multiple ester bonds and carboxy groups in the molecule. In particular, it is more preferable that the polyester resin (A) contains two or more carboxy groups in the molecular chain, more preferably three or more carboxy groups, and even more preferably four or more carboxy groups. The number of carboxy groups per molecular chain (N COOH There is no particular upper limit to the score, but it is sufficient if it is 50 points or less, and even 30 points or less is acceptable.

[0014] The aromatic polyester resin (A) containing a carboxy group in its side chain preferably has a number average molecular weight (Mn) of 8,000 or more, more preferably 10,000 or more, and even more preferably 12,000 or more. The number average molecular weight is preferably 30,000 or less, more preferably 25,000 or less, and even more preferably 20,000 or less. By keeping the number average molecular weight within the above range, it becomes easier to control the acid value of the polyester resin (A).

[0015] The glass transition temperature of the polyester resin (A) is preferably −10° C. or higher, more preferably 0° C. or higher, and even more preferably 5° C. or higher. The glass transition temperature is preferably 100° C. or lower, more preferably 80° C. or lower, and even more preferably 60° C. or lower.

[0016] The aromatic polyester resin (A) containing a carboxyl group in the side chain must have a side chain (hereinafter also referred to as a branched structure) and an aromatic group in the molecule. For the polyester resin (A) to have a branched structure and an aromatic group, it is preferable that the copolymerization component used as the raw material has a branched structure and an aromatic group. The polyester resin (A) may be (i) a product obtained by reacting (copolymerizing) a high molecular weight polyol with a chain extender or the like, or (ii) a product obtained by adding a monomer having a carboxyl group to a polyester having a reactive site obtained by reacting a polycarboxylic acid component with a polyalcohol component.

[0017] In the case of (i), at least one of the polymer polyol and / or the chain extender may have a branched structure and the other may have an aromatic group, or one may have both a branched structure and an aromatic group. One or more polymer polyols may be used in combination. When two or more polymer polyols are used in combination, one polymer polyol may have a branched structure and the other may have an aromatic group, or one may have both a branched structure and an aromatic group. Furthermore, in the case of (ii), at least one of the polyester and / or the addition monomer having a carboxy group may have an aromatic group, or both may have aromatic groups.

[0018] The polycarboxylic acid component used in the aromatic polyester resin (A) containing a carboxy group in its side chain is preferably an aromatic dicarboxylic acid component. Examples of aromatic dicarboxylic acid components include, but are not limited to, terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, biphenyldicarboxylic acid, and diphenic acid. Other examples include aromatic dicarboxylic acids containing sulfonic acid groups, such as sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, and 5(4-sulfophenoxy)isophthalic acid, as well as aromatic dicarboxylic acids containing sulfonate salt groups, such as their metal salts and ammonium salts. These can be used alone or in combination. Terephthalic acid, isophthalic acid, and mixtures thereof are particularly preferred for increasing the cohesive strength of the coating film.

[0019] Other polycarboxylic acid components include alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,2-cyclohexanedicarboxylic acid and their anhydrides, aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, and dimer acid, and unsaturated bond-containing dicarboxylic acids such as maleic acid and fumaric acid and their anhydrides. Also usable are hydroxycarboxylic acid compounds having a hydroxyl group and a carboxyl group in their molecular structure, such as 5-hydroxyisophthalic acid, p-hydroxybenzoic acid, p-hydroxyphenethyl alcohol, p-hydroxyphenylpropionic acid, p-hydroxyphenylacetic acid, 6-hydroxy-2-naphthoic acid, and 4,4-bis(p-hydroxyphenyl)valeric acid, and thiomalic acid having a thiol group in their molecular structure.

[0020] The polyalcohol component used in the aromatic polyester resin (A) containing a carboxy group in its side chain is preferably a glycol component, and the glycol component is preferably an aliphatic glycol, an alicyclic glycol, an aromatic-containing glycol, or an ether bond-containing glycol.

[0021] Examples of aliphatic glycols include ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, 2-methyl-1,3-butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 2-ethyl-2-butylpropanediol (DMH), hydroxypivalic acid neopentyl glycol ester, dimethylolheptane, and 2,2,4-trimethyl-1,3-pentanediol.

[0022] Examples of alicyclic glycols include 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, tricyclodecanediol, tricyclodecanedimethylol, spiroglycol, hydrogenated bisphenol A, ethylene oxide adducts and propylene oxide adducts of hydrogenated bisphenol A, and the like.

[0023] Examples of aromatic-containing glycols include paraxylene glycol, metaxylene glycol, orthoxylene glycol, 1,4-phenylene glycol, an ethylene oxide adduct of 1,4-phenylene glycol, bisphenol A, an ethylene oxide adduct and a propylene oxide adduct of bisphenol A, which are glycols obtained by adding 1 to several moles of ethylene oxide or propylene oxide to two phenolic hydroxyl groups of bisphenols. Specific examples of glycol-modified aromatic dicarboxylic acids include, but are not limited to, bis-2-hydroxyethyl terephthalate (BHET), which is an ethylene glycol-modified terephthalic acid, a propylene glycol-modified terephthalic acid, an ethylene glycol-modified isophthalic acid, a propylene glycol-modified isophthalic acid, an ethylene glycol-modified orthophthalic acid, and a propylene glycol-modified orthophthalic acid. Further, other 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 metal salts or ammonium salts thereof.

[0024] Examples of ether bond-containing glycols include diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, neopentyl glycol ethylene oxide adduct, and neopentyl glycol propylene oxide adduct.

[0025] These can be used alone or in combination of two or more.

[0026] The polymer polyol used in the aromatic polyester resin (A) containing a carboxy group in the side chain is preferably a copolymer of the polycarboxylic acid component and the polyol component (polymer polyester polyol). In addition, in order to impart an acid value to the polymer polyol, it is also preferable to add an acid to the polymer polyol using a polycarboxylic acid compound having three or more functional groups.

[0027] Examples of tri- or higher functional polycarboxylic acid components include trimellitic acid, trimesic acid, ethylene glycol bis(anhydrotrimellitate), glycerol tris(anhydrotrimellitate), trimellitic anhydride, pyromellitic anhydride (PMDA), oxydiphthalic dianhydride (ODPA), 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), 3,3',4,4'-diphenyltetracarboxylic dianhydride (BPDA), 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride (DSDA), 4,4'-(hexafluoroisopropylidene)diphthalic dianhydride (6FDA), 2,2'-bis[(dicarboxyphenoxy)phenyl]propane dianhydride (BSAA), etc. On the other hand, examples of tri- or higher functional polyols include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, etc.

[0028] The number average molecular weight (Mn) of the polymer polyol is preferably 1000 or more, more preferably 2000 or more, and even more preferably 3000 or more. The number average molecular weight is preferably 30000 or less, more preferably 25000 or less, and even more preferably 20000 or less.

[0029] The acid value of the polymer polyol is preferably 0.1 mgKOH / g or more, more preferably 0.2 mgKOH / g or more, and even more preferably 0.3 mgKOH / g or more, and is preferably 20 mgKOH / g or less, more preferably 15 mgKOH / g or less, and even more preferably 10 mgKOH / g or less.

[0030] The glass transition temperature of the polymer polyol is preferably −10° C. or higher, more preferably 0° C. or higher, and even more preferably 5° C. or higher. The glass transition temperature is preferably 100° C. or lower, more preferably 80° C. or lower, and even more preferably 60° C. or lower.

[0031] The chain extender is not particularly limited, but may include tetracarboxylic dianhydrides.

[0032] The tetracarboxylic dianhydride may be an aromatic tetracarboxylic dianhydride, an aliphatic tetracarboxylic dianhydride, or an alicyclic tetracarboxylic dianhydride, with aromatic tetracarboxylic dianhydride being preferred. Specific examples include pyromellitic anhydride (PMDA), oxydiphthalic dianhydride (ODPA), 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), 3,3',4,4'-diphenyltetracarboxylic dianhydride (BPDA), 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride (DSDA), 4,4'-(hexafluoroisopropylidene)diphthalic dianhydride (6FDA), and 2,2'-bis[(dicarboxyphenoxy)phenyl]propane dianhydride (BSAA). These may be used alone or in combination of two or more. Among these, pyromellitic anhydride is preferred.

[0033] The copolymerization ratio of the polymer polyol and the chain extender is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 2 parts by mass or more, per 100 parts by mass of the polymer polyol, and is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less, per 100 parts by mass of the polymer polyol.

[0034] For the aromatic polyester resin (A) containing a carboxy group in the side chain, a polyester containing multiple carboxy groups is preferably used. There are two methods for introducing an acid value into the polyester resin (A).

[0035] The first method is to introduce carboxylic acid into polyester polyol by acid addition after polymerization. When monocarboxylic acid, dicarboxylic acid, or trifunctional or higher polycarboxylic acid compound is used for acid addition, molecular weight may decrease due to ester exchange, so it is preferable to use a compound having at least one carboxylic anhydride group.

[0036] Examples of carboxylic acid anhydrides include succinic anhydride, maleic anhydride, phthalic anhydride, 2,5-norbornene dicarboxylic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride (PMDA), oxydiphthalic dianhydride (ODPA), 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), 3,3',4,4'-diphenyltetracarboxylic dianhydride (BPDA), 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride (DSDA), 4,4'-(hexafluoroisopropylidene)diphthalic dianhydride (6FDA), and 2,2'-bis[(dicarboxyphenoxy)phenyl]propane dianhydride (BSAA).

[0037] In the second method, a polyester precursor containing multiple double bond sites is obtained by melt polycondensation using a glycol-modified aromatic dicarboxylic acid as the diol component and maleic acid as the dicarboxylic acid component. When this precursor is reacted with, for example, thioglycolic acid, a Michael addition reaction occurs between the double bond sites derived from maleic acid and the thiol group, resulting in a polyester resin (A) containing multiple carboxyl groups in the side chain.

[0038] <Epoxy compound (B)> The epoxy compound (B) is not particularly limited, but is preferably a compound having two or more epoxy groups in the molecule. The compound having two or more epoxy groups in the molecule (epoxy crosslinking agent) is not particularly limited as long as it undergoes a curing reaction with the carboxyl group of the polyester resin (A) to form a crosslink, but is preferably a polyfunctional epoxy compound having multiple epoxy groups in one molecule. By using a polyfunctional epoxy compound, the cured coating film obtained from the crosslinked aromatic polyester resin composition is more likely to form three-dimensional crosslinks, making it possible to improve heat resistance.

[0039] Examples of polyfunctional epoxy compounds include cresol novolac epoxy compounds, epoxy compounds having a dicyclopentadiene skeleton, and phenol novolac epoxy compounds, which can be used alone or in combination of two or more.

[0040] Furthermore, in addition to the polyfunctional epoxy compounds, nitrogen-containing epoxy compounds can also be used. The use of nitrogen-containing epoxy compounds in combination is preferred because it allows the coating film of the resin composition to be semi-cured by heating at a relatively low temperature and is expected to have the effect of suppressing foaming.

[0041] Examples of epoxy compounds containing a nitrogen atom include glycidylamines such as tetraglycidyldiaminodiphenylmethane, triglycidyl paraaminophenol, tetraglycidyl bisaminomethylcyclohexanone, and N,N,N',N'-tetraglycidyl-m-xylenediamine.

[0042] Commercially available nitrogen atom-containing epoxy compounds include "TETRAD-X" (trade name) manufactured by Mitsubishi Gas Chemical Company, Inc. and "jER630" (trade name) manufactured by Mitsubishi Chemical Corporation.

[0043] Other epoxy compounds can also be used in combination as the epoxy compound (B) used in the present invention. Examples include glycidyl ether types such as bisphenol A diglycidyl ether, bisphenol S diglycidyl ether, and brominated bisphenol A diglycidyl ether, glycidyl ester types such as hexahydrophthalic acid glycidyl ester and dimer acid glycidyl ester, and alicyclic or aliphatic epoxides such as triglycidyl isocyanurate, 3,4-epoxycyclohexylmethylcarboxylate, epoxidized polybutadiene, and epoxidized soybean oil. These may be used alone or in combination of two or more.

[0044] The number average molecular weight (Mn) of the epoxy compound (B) is preferably 100 or more and 500 or less, more preferably 200 or more and 400 or less, from the viewpoint of crosslink density.

[0045] <Crosslinked aromatic polyester resin (C)> The crosslinked aromatic polyester resin (C) is a reaction product of the polyester resin (A) and the epoxy compound (B). The reaction may be carried out in the absence of a solvent or in the presence of an organic solvent.

[0046] The organic solvent is not particularly limited as long as it does not react with the polyester resin (A), the epoxy compound (B), and the crosslinked aromatic polyester resin (C), and examples thereof include aromatic organic solvents such as toluene and xylene, aliphatic organic solvents such as heptane and octane, ether solvents such as tetrahydrofuran and diethyl ether, and amide solvents such as dimethylformamide and N-methylpyrrolidone. These can be used alone or in combination of two or more.

[0047] The reaction temperature is preferably 80° C. or higher, more preferably 100° C. or higher, and even more preferably 120° C. or higher. The reaction temperature is preferably 200° C. or lower, more preferably 180° C. or lower, and even more preferably 160° C. or lower.

[0048] The reaction time, although it depends on the reaction temperature, is preferably 30 minutes or more, more preferably 1 hour or more, and even more preferably 2 hours or more, and is preferably 10 hours or less, more preferably 8 hours or less, and even more preferably 5 hours or less.

[0049] The mixing ratio of the polyester resin (A) and the epoxy compound (B) can be determined based on the functional group molar ratio between the carboxy groups in the side chains of the polyester resin (A) and the epoxy groups in the epoxy compound (B). From the viewpoint of crosslinking reaction efficiency, the ratio of the carboxy groups in the polyester resin (A) to the epoxy groups in the epoxy compound (B) (carboxy groups:epoxy groups) is preferably 100:50 to 100:150 (mol parts), more preferably 100:80 to 100:120 (mol parts).

[0050] <Transesterification catalyst (D)> The transesterification catalyst (D) is a catalyst for transesterification of the ester groups in the polyester resin (A). The transesterification catalyst (D) causes "dynamic" covalent crosslinking, which allows bond exchange at high temperatures, in the crosslinked aromatic polyester resin composition of the present invention. This results in high strength at room temperature, and reprocessing and film adhesion are possible above the ester bond exchange activation temperature. Furthermore, the remoldability of the crosslinked aromatic polyester resin composition allows for molding and thinning after the crosslinking reaction, and its self-healing ability allows for the repair of scratches, allowing for semi-permanent use. The ester bond exchange activation temperature of the crosslinked aromatic polyester resin composition can be determined as the softening temperature based on the inflection point of the change in the linear expansion coefficient.

[0051] Examples of the transesterification catalyst (D) include zinc acetate, triphenylphosphine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, and 1,8-diazabicyclo[5.4.0]undecene-7, among which zinc acetate is preferred.

[0052] The amount of the transesterification catalyst (D) mixed is preferably 10 to 40 parts by mole, more preferably 15 to 30 parts by mole, per 100 parts by mole of carboxy groups in the polyester resin (A), from the viewpoint of the mechanical strength of the polyester resin (A) and the uniformity of the sample.

[0053] <Crosslinked aromatic polyester resin composition> The crosslinked aromatic polyester resin composition is a composition containing the crosslinked aromatic polyester resin (C) and the transesterification catalyst (D).

[0054] The crosslinked aromatic polyester resin composition exhibits a wavenumber of 1730 cm attributable to ester bonds when measured by infrared spectroscopy. -1 The absorbance (A 1730 ) for the hydroxyl group-derived wavenumber of 3200-3600 cm -1 The absorbance (A 3200-3600 ) ratio (A 3200-3600 / A 1730 ) is 0.005 or more and 0.038 or less. Since the self-repairing property, remolding property and scratch repairing property are good, the ratio (A 3200-3600 / A 1730 ) is preferably 0.007 or more, more preferably 0.01 or more. 3200-3600 / A 1730 ) is preferably 0.035 or less, more preferably 0.03 or less. The measurement method by infrared spectroscopy is as described in the Examples.

[0055] An example of a method for producing a crosslinked aromatic polyester resin composition is shown below. The crosslinked aromatic polyester resin composition can be obtained by mixing a polyester resin (A), an epoxy compound (B), and a transesterification catalyst (D), heating the mixture, and carrying out a crosslinking reaction via an epoxy ring-opening reaction. The order in which the polyester resin (A), the epoxy compound (B), and the transesterification catalyst (D) are mixed is not particularly limited, but it is preferable to mix the polyester resin (A) and the epoxy compound (B) first, then add the transesterification catalyst (D) to carry out the crosslinking reaction.

[0056] The softening temperature of the crosslinked aromatic polyester resin composition is preferably 100° C. or higher, more preferably 110° C. or higher, and even more preferably 120° C. or higher. There are no particular limitations on the upper limit of the softening temperature, but from an industrial perspective, it is sufficient that the softening temperature is 300° C. or lower, and it may even be 250° C. or lower.

[0057] The temperature at which the crosslinked aromatic polyester resin composition loses 5% weight when heated (5% weight loss temperature) is 230° C. or higher, preferably 250° C. or higher, more preferably 280° C. or higher, and even more preferably 300° C. or higher. There are no particular limitations on the upper limit of the 5% weight loss temperature, but from an industrial perspective, it is sufficient that it is 500° C. or lower, and it may even be 450° C. or lower. The 5% weight loss temperature can be used as an indicator of heat resistance.

[0058] Molded articles made from crosslinked aromatic polyester resin compositions can be formed in a variety of shapes, but a film shape is preferred from the viewpoint of maintaining a sufficient adhesive area. That is, the crosslinked aromatic polyester resin composition of the present invention can be used as a film-shaped adhesive, and can be used as an adhesive between resin films, between metal foils, or between a resin film and a metal foil. Examples of resin films include polyimide film, polyester film, and PET film. Examples of metal foils include copper foil, silver foil, and gold foil. The adhesiveness of the crosslinked aromatic polyester resin composition can be evaluated based on the 90° peel strength shown in the examples.

[0059] The crosslinked aromatic polyester resin composition is capable of bond exchange when heated above its ester bond exchange activation temperature. Therefore, when the crosslinked aromatic polyester resin composition is used as an adhesive material, the adhesive becomes easily peeled by heating the adhesive above its ester bond exchange activation temperature. Therefore, the crosslinked aromatic polyester resin composition can be used as a material for adhesives for repair applications that can be applied and removed. The peelability of the crosslinked aromatic polyester resin composition when heated to a high temperature can be evaluated based on the 90° peel strength when heated, as shown in the examples.

[0060] The crosslinked aromatic polyester resin composition can be used as a laminating material. Since the crosslinked aromatic polyester resin composition has heat resistance, for example, by laminating a film using the crosslinked aromatic polyester resin composition on the surface of a resin molded body or a metal molded body, the heat resistance of the resin molded body or the metal molded body can be improved. The effect as a laminating material can be evaluated by the solder heat resistance shown in the examples.

[0061] The crosslinked aromatic polyester resin composition is hardly dissolved even when immersed in a solvent (especially an organic solvent), and therefore has good solvent resistance. Therefore, the crosslinked aromatic polyester resin composition can be suitably used as, for example, a laminating material.

[0062] The crosslinked aromatic polyester resin composition has good room temperature storage stability. That is, even when stored at a predetermined temperature for a predetermined period of time, the gel fraction hardly changes. Furthermore, even when stored at a predetermined temperature for a predetermined period of time, the composition exhibits softening behavior similar to that before storage.

[0063] The crosslinked aromatic polyester resin composition can be used as a self-adhesive, a self-repairing material, or a main component of a molding material.

[0064] The self-repairing material can be used, for example, as a paint material.

[0065] The crosslinked aromatic polyester resin composition has good moldability and extrusion moldability, and is therefore useful as a molding material, and can be used, for example, as a material for 3D printers or a material for filamentous molded articles.

[0066] The crosslinked aromatic polyester resin composition can also be used as a material for a network structure. A network structure is a structure in which parts of filamentous molded articles are connected to each other. The network structure can be produced by melting the crosslinked aromatic polyester resin composition, discharging the molten material from a nozzle, and solidifying the discharged material while welding it together.

[0067] The content of the crosslinked aromatic polyester resin composition in the solid content of the self-adhesive, self-repairing material, or molding material is preferably 60% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more, and may be 100% by mass.

[0068] This application claims the benefit of priority based on Japanese Patent Application No. 2020-174488, filed on October 16, 2020. The entire contents of the specification of Japanese Patent Application No. 2020-174488 are incorporated herein by reference. [Example]

[0069] In order to explain the present invention in more detail, examples and comparative examples are given below, but the present invention is not limited to these examples. The measured values ​​described in the examples and comparative examples were measured by the following methods. Unless otherwise specified, "parts" means "parts by mass" and "moles" means "parts by mole."

[0070] Polymerization example of high molecular weight polyol (A1-1) A reactor equipped with a stirrer, thermometer, and distillation condenser was charged with 30 mol parts of terephthalic acid, 69 mol parts of isophthalic acid, 1 mol part of trimellitic anhydride, 15 mol parts of 2-methyl-1,3-butanediol, 85 mol parts of 1,6-hexanediol, and 0.2 mol parts of tetrabutyl titanate. The temperature was gradually raised to 250 °C, and the esterification reaction was carried out while removing the distilled water from the system. After the esterification reaction was completed, the pressure was gradually reduced to 10 mmHg to carry out initial polymerization, and the temperature was raised to 250 °C. Further polymerization was carried out at a pressure of 1 mmHg or less until the specified torque was reached. The pressure was then returned to normal with nitrogen, and 1 mol part of trimellitic anhydride was added. The reaction was carried out at 220 °C for 30 minutes to obtain polymer polyol (A1-1). The composition and properties of the polymer polyol (A1-1) obtained in this manner are shown in Table 1. Measurements and evaluation items were performed according to the methods described below.

[0071] Polymerization example of high molecular weight polyol (A1-2) A reactor equipped with a stirrer, thermometer, and distillation condenser was charged with 50 mol parts of terephthalic acid, 50 mol parts of isophthalic acid, 55 mol parts of ethylene glycol, 45 mol parts of 2,2-dimethyl-1,3-propanediol, and 0.2 mol parts of tetrabutyl titanate. The temperature was gradually raised to 250 °C, and the esterification reaction was carried out while removing the distilled water from the system. After the esterification reaction, the pressure was gradually reduced to 10 mmHg while performing initial polymerization. The temperature was then raised to 250 °C, and further polymerization was carried out at 1 mmHg or less until the specified torque was reached, thereby obtaining a polymer polyol (A1-2). The composition and properties of the polymer polyol (A1-2) obtained in this manner are shown in Table 1. Measurements and evaluation items were performed according to the methods described below.

[0072] Polymerization example of high molecular weight polyol (A1-3) A reactor equipped with a stirrer, thermometer, and distillation condenser was charged with 50 mol parts of terephthalic acid, 49 mol parts of isophthalic acid, 1 mol part of trimellitic anhydride, 83 mol parts of 2-methyl-1,3-butanediol, 17 mol parts of 1,4-butanediol, and 0.2 mol parts of tetrabutyl titanate. The temperature was gradually raised to 250 °C, and the esterification reaction was carried out while removing the distilled water from the system. After the esterification reaction was completed, the pressure was gradually reduced to 10 mmHg to carry out initial polymerization, and the temperature was raised to 250 °C. Further polymerization was carried out at a predetermined torque below 1 mmHg. The pressure was then returned to normal with nitrogen, and 1 mol part of trimellitic anhydride was added. The reaction was carried out at 220 °C for 30 minutes to obtain polymer polyol (A1-3). The composition and properties of the polymer polyol (A1-3) obtained in this manner are shown in Table 1. Measurements and evaluation items were performed according to the methods described below.

[0073] Polymerization example of high molecular weight polyol (A1-4) A reactor equipped with a stirrer, thermometer, and distillation condenser was charged with 40 mol parts of terephthalic acid, 39 mol parts of isophthalic acid, 20 mol parts of adipic acid, 1 mol part of trimellitic anhydride, 58 mol parts of 2-methyl-1,3-butanediol, 42 mol parts of 1,4-butanediol, and 0.2 mol parts of tetrabutyl titanate. The temperature was gradually raised to 250 °C, and the esterification reaction was carried out while removing the distilled water from the system. After the esterification reaction was completed, the pressure was gradually reduced to 10 mmHg while performing initial polymerization. The temperature was then raised to 250 °C, and the final polymerization was carried out at 1 mmHg or less until the specified torque was reached. The pressure was then returned to normal with nitrogen, and 1 mol part of trimellitic anhydride was added. The reaction was carried out at 220 °C for 30 minutes to obtain polymer polyol (A1-4). The composition and properties of the polymer polyol (A1-4) obtained in this manner are shown in Table 1. Measurements and evaluation items were performed according to the methods described below.

[0074] Polymerization example of high molecular weight polyol (A1-5) A reactor equipped with a stirrer, thermometer, and distillation condenser was charged with 30 mol parts of terephthalic acid, 64 mol parts of isophthalic acid, 5 mol parts of sebacic acid, 1 mol part of trimellitic anhydride, 28 mol parts of 2-methyl-1,3-butanediol, 55 mol parts of 1,4-butanediol, 17 mol parts of 1,4-cyclohexanedimethanol, and 0.2 mol parts of tetrabutyl titanate. The temperature was gradually raised to 250 °C, and the esterification reaction was carried out while removing the distilled water from the system. After the esterification reaction was completed, the pressure was gradually reduced to 10 mmHg to carry out initial polymerization, and the temperature was raised to 250 °C. The final polymerization was carried out at a pressure of 1 mmHg or less until the specified torque was reached. The pressure was then returned to normal with nitrogen, and 1 mol part of trimellitic anhydride was added. The reaction was carried out at 220 °C for 30 minutes to obtain polymer polyol (A1-5). The composition and properties of the polymer polyol (A1-5) obtained in this manner are shown in Table 1. Each measurement and evaluation item was performed according to the methods described below.

[0075] As the polymer polyol (T5652), polycarbonate diol "T5652" (number average molecular weight 2000) manufactured by Asahi Kasei Corporation was used.

[0076] Synthesis example of aromatic polyester resin (A-1) containing carboxyl groups in the side chains In a reactor equipped with a stirrer, thermometer, and reflux condenser, 80 parts of polymer polyol (A1-1), 20 parts of polymer polyol (A1-2), 2.6 parts of pyromellitic anhydride, and 100 parts of toluene were charged and dissolved in toluene while gradually increasing the temperature to 80 ° C. After dissolution was complete, 0.05 parts of triethylamine was added as a reaction catalyst, and the temperature was gradually increased to 105 ° C. and the reaction was continued for 24 hours. After confirming the completion of the reaction by IR (infrared spectroscopy), the mixture was diluted with 54 parts of toluene to obtain a solution of aromatic polyester resin (A-1) containing carboxy groups in the side chains with a solids concentration of 40%. The composition and properties of the aromatic polyester resin (A-1) containing carboxy groups in the side chains obtained in this manner are shown in Table 2.

[0077] Synthesis example of aromatic polyester resin (A-2) containing carboxyl groups in the side chain In a reactor equipped with a stirrer, thermometer, and reflux condenser, 80 parts of polymer polyol (A1-3), 20 parts of polymer polyol (A1-2), 2.6 parts of pyromellitic anhydride, and 100 parts of toluene were charged and dissolved in toluene while gradually increasing the temperature to 80 ° C. After dissolution was complete, 0.05 parts of triethylamine was added as a reaction catalyst, and the temperature was gradually increased to 105 ° C. and the reaction was continued for 24 hours. After confirming the completion of the reaction by IR, the mixture was diluted with 54 parts of toluene to obtain a solution of aromatic polyester resin (A-2) containing carboxy groups in the side chains with a solids concentration of 40%. The composition and properties of the aromatic polyester resin (A-2) containing carboxy groups in the side chains obtained in this manner are shown in Table 2.

[0078] As the aromatic polyester resin (A-3), a polymer polyol (A1-2) was used.

[0079] Preparation of aromatic polyester resin (A-4) containing carboxyl groups in the side chains A 50 ml glass flask equipped with a stirrer was charged with 25 mol parts maleic acid, 25 mol parts adipic acid, 50 mol parts bis-2-hydroxyethyl terephthalate (BHET), and 0.5 mol parts scandium triflate and homogenized at 100°C. After dissolving the raw materials, the pressure in the system was gradually reduced to 5 mmHg over 30 minutes. The polycondensation reaction was then carried out at 110°C for 4 hours under a vacuum of 0.3 mmHg or less. The contents were then removed and cooled. Subsequently, a side-chain carboxy-containing aromatic polyester resin (A-4) was prepared by Michael addition of the double bond sites of maleic acid and the thiol groups of thioglycolic acid, which contained multiple carboxy groups in the side chain. The composition and properties of the resulting side-chain carboxy-containing aromatic polyester resin (A-4) are shown in Table 3.

[0080] Preparation of aromatic polyester resin (A-5) containing carboxyl groups in the side chains The aromatic polyester resin (A-5) containing a carboxyl group in the side chain was synthesized in the same manner as the aromatic polyester resin (A-4) containing a carboxyl group in the side chain, except that the charging ratio was changed, and the same evaluation was carried out as for the aromatic polyester resin (A-4) containing a carboxyl group in the side chain. The evaluation results are shown in Table 3.

[0081] Synthesis example of aromatic polyester resin (A-6) containing carboxyl groups in the side chain In a reactor equipped with a stirrer, thermometer, and reflux condenser, 70 parts of polymer polyol (A1-4), 30 parts of polymer polyol (A1-2), 2.5 parts of pyromellitic anhydride, and 100 parts of toluene were charged and dissolved in toluene while gradually increasing the temperature to 80 ° C. After dissolution was complete, 0.05 parts of triethylamine was added as a reaction catalyst, and the temperature was gradually increased to 105 ° C. and the reaction was continued for 24 hours. After confirming the completion of the reaction by IR, the mixture was diluted with 54 parts of toluene to obtain a solution of aromatic polyester resin (A-6) containing carboxy groups in the side chains with a solids concentration of 40%. The composition and properties of the aromatic polyester resin (A-6) containing carboxy groups in the side chains obtained in this manner are shown in Table 2.

[0082] Synthesis example of aromatic polyester resin (A-7) containing carboxyl groups in the side chain In a reactor equipped with a stirrer, thermometer, and reflux condenser, 80 parts of polymer polyol (A1-5), 20 parts of Asahi Kasei Corporation's polycarbonate diol "T5652," 2.8 parts of pyromellitic anhydride, and 100 parts of toluene were charged and dissolved in toluene while gradually increasing the temperature to 80 ° C. After dissolution was complete, 0.05 parts of triethylamine was added as a reaction catalyst, and the temperature was gradually increased to 105 ° C. The reaction was allowed to proceed for 24 hours. After confirming the completion of the reaction by IR, the mixture was diluted with 54 parts of toluene to obtain a solution of aromatic polyester resin (A-7) containing carboxy groups in the side chains with a solids concentration of 40%. The composition and properties of the aromatic polyester resin (A-7) containing carboxy groups in the side chains obtained in this manner are shown in Table 2.

[0083] [Table 1]

[0084] [Table 2]

[0085] [Table 3]

[0086] <Number average molecular weight (Mn)> Samples [polymer polyols (A1-1 to A1-5) and aromatic polyester resins (A-1 to A-7) containing carboxyl groups in the side chains] were dissolved or diluted in tetrahydrofuran to a sample 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 number-average molecular weight was measured by gel permeation chromatography using tetrahydrofuran 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. However, when the sample was insoluble in tetrahydrofuran, N,N-dimethylformamide was used instead. Low molecular weight compounds (oligomers, etc.) with a number-average molecular weight of less than 1000 were not counted and were omitted.

[0087] <Acid value> 0.2 g of sample [polymer polyols (A1-1 to A1-5), aromatic polyester resins containing carboxyl groups in the side chains (A-1 to A-7)] was dissolved in 20 ml of chloroform and titrated with a 0.1 N potassium hydroxide ethanol solution using phenolphthalein as an indicator. From this titration amount, the number of mg of KOH consumed for neutralization was converted to the amount per 1 g of resin to calculate the acid value (mg KOH / g).

[0088] <Number of carboxyl groups> The number of carboxyl groups can be calculated using the following method. For example, if the acid value is A (mg KOH / g), the number of moles of carboxyl groups per 1 g of aromatic polyester resin (A) containing carboxyl groups in the side chains can be expressed as A / 56.1 (mmol / g), since the molecular weight of KOH is 56.1 g / mol. If the number average molecular weight of aromatic polyester resin (A) containing carboxyl groups in the side chains is B (g), the number of carboxyl groups in the polymer can be expressed as A / 56.1 x B / 1000 (mol), which can be used as the number of carboxyl groups per polymer chain (N COOH ) was decided.

[0089] <Glass transition temperature> Using a differential scanning calorimeter "DSC220" manufactured by Seiko Electronics Co., Ltd., 5 mg of samples [polymer polyols (A1-1 to A1-5), aromatic polyester resins containing carboxyl groups in the side chains (A-1 to A-7)] were placed in an aluminum pan, the pan was sealed with a lid, and the pan was held at 250°C for 5 minutes, then rapidly cooled with liquid nitrogen. After that, the pan was heated from -100°C to 300°C at a heating rate of 20°C / min. The inflection point of the obtained curve was taken as the glass transition temperature.

[0090] Example 1 A crosslinked aromatic polyester resin composition in the form of a film (hereinafter referred to as a crosslinked aromatic polyester resin film) was prepared as follows.

[0091] 100 mole parts of carboxy groups in the side chain-containing aromatic polyester resin (A-1) were dissolved in NMP (N-methyl-2-pyrrolidone) with 50 mole parts of 1,4-butanediol diglycidyl ether as the epoxy compound (B) so that the carboxy group / epoxy group ratio was 1 / 1 (functionality) per 100 mole parts of carboxy groups. Separately, 20 mole parts of the transesterification catalyst Zn(OAc)2 was dissolved in NMP (N-methyl-2-pyrrolidone). These two solutions were mixed in a Teflon mold, and the solvent was then evaporated on a heater at 40°C. This mixed sample was heated at 140°C for 3 hours to obtain a crosslinked aromatic polyester resin film (thickness 0.7 mm). The results are shown in Table 4.

[0092] Examples 2 to 8, Comparative Examples 1 to 5 The aromatic polyester resin (A-1) containing a carboxy group in the side chain and the epoxy compound (B) were changed to those shown in Table 4, and Examples 2 to 8 and Comparative Examples 1 to 5 were carried out in the same manner as in Example 1, with the blending amounts changed to those shown in Table 4. The results are shown in Table 4.

[0093] The epoxy compounds (B) used in Table 4 are as follows: "jER630" (trade name) (triglycidyl para-aminophenol) manufactured by Mitsubishi Chemical Corporation Multifunctional epoxy compound "TETRAD-X" (trade name) (N,N,N',N'-tetraglycidyl-m-xylenediamine) manufactured by Mitsubishi Gas Chemical Company, Inc.

[0094] (Absorbance measurement by infrared spectroscopy) The infrared absorption spectrum of the obtained crosslinked aromatic polyester resin film was measured by the ATR method (attenuated total reflection method) under the following conditions using an Agilent Technologies "Cary 660 FTIR." The measurement was performed 16 times. The peak at 1730 cm originating from the ester bond was observed. -1 The absorbance (A 1730 ) is 1730±10cm -1The value of the absorption peak height with an absorption maximum in the region of 3200-3600 cm originating from the hydroxyl group -1 The absorbance (A 3200-3600 ) is 3200~3600cm -1 The absorbance ratio was calculated from the absorbance values ​​obtained using the following formula: (absorbance ratio)=A 3200-3600 / A 1730

[0095] Table 4 shows 1730±10cm -1 The peak position of the absorption peak with an absorption maximum in the region of 3200-3600 cm -1 The peak positions of the absorption peaks with absorption maxima in the region are shown.

[0096] [Table 4-1]

[0097] [Table 4-2]

[0098] [Table 4-3]

[0099] (Softening temperature) The softening temperature was determined from the bending point of the change in the linear expansion coefficient of the sample (crosslinked aromatic polyester resin film) from room temperature to 300°C using a Hitachi "TMA7100." Measurements were performed in a nitrogen gas atmosphere with a small constant tension (30 mN) applied to prevent sample deflection. The initial jig distance was 15 mm. If a bending point was observed, the corresponding temperature was recorded; if not, it was recorded as "-."

[0100] (Self-adhesive) Two cross-linked aromatic polyester resin films (4 mm wide x 2 cm long x 0.7 mm thick) were overlapped at one end by approximately 1 cm, and pressed at a temperature above the softening temperature, with a pressure of 400 kPa, for two hours to produce a two-layer cross-linked aromatic polyester resin film. Self-adhesiveness was evaluated as 'good' when the two layers bonded together, and 'poor' when they did not.

[0101] (Remoldability) A crosslinked aromatic polyester resin film (4 mm wide x 2 cm long x 0.7 mm thick) was wrapped around a spatula, both ends secured with tape, and then subjected to a heat treatment process. The heat treatment process involved leaving the film at a high temperature (softening temperature + approximately 20°C) for 2 hours and then allowing it to cool to room temperature. After allowing it to cool, the deformed crosslinked polyester resin film was removed from the spatula. When the deformed crosslinked aromatic polyester resin film was removed from the spatula, it was evaluated as 'good' for remoldability if it maintained its wrapped state. When it did not maintain its wrapped state and returned to its original flat state, it was evaluated as 'bad' for remoldability. Furthermore, cases in which a portion of the crosslinked aromatic polyester resin film melted and could not be evaluated were evaluated as '-'.

[0102] (Scratch repair) Scratches (approximately 0.1 mm deep) were made on the surface of a crosslinked aromatic polyester resin film (1.5 cm long x 1.5 cm wide x 0.7 mm thick) using a cutter. The crosslinked aromatic polyester resin film was then subjected to a heat treatment process. The heat treatment process involved leaving the film at a high temperature (softening temperature + approximately 20°C) for 10 minutes and then allowing it to cool to room temperature. If the scratches disappeared after the heat treatment process, resulting in a crosslinked aromatic polyester resin film with no scratches on the surface, the scratch repairability (self-repairability) was evaluated as ◯; if scratches remained, the scratch repairability (self-repairability) was evaluated as ×. In addition, if part of the crosslinked aromatic polyester resin film melted and could not be evaluated, the scratch repairability (self-repairability) was evaluated as -.

[0103] (5% weight loss temperature) Measurements were taken using a Shimadzu DTG-60 thermal analyzer. 10 g of the sample (crosslinked aromatic polyester resin film) was placed in an aluminum pan, and the weight loss was measured as the temperature was raised from room temperature to 400°C at a rate of 5°C / min. The temperature at which the weight had decreased by 5% (5% weight loss temperature) was used as an index of heat resistance.

[0104] (90° peel strength) A test piece measuring 20 mm long x 50 mm wide was cut from the resulting crosslinked aromatic polyester resin film (0.7 mm thick). The cut test piece was placed on a 25 μm thick PET film (manufactured by Toyobo Co., Ltd.), and another PET film of the same type was placed on top of the test piece to form a three-layer structure of "PET film / crosslinked aromatic polyester resin film / PET film." The layers were then bonded together by heating and pressurizing at 170°C, 2 MPa, and 280 seconds in a heat press. The resulting laminate was used as a sample for evaluating 90° peel strength.

[0105] Furthermore, a polyimide film (PI, "Apical" (registered trademark) manufactured by Kaneka Corporation, thickness 12.5 μm) was used instead of the PET film, and a sample for evaluating 90° peel strength was prepared under the same conditions except for a three-layer structure of "PI / crosslinked aromatic polyester resin film / PI." For the crosslinked aromatic polyester resin films obtained in Examples 5 and 6, samples were also prepared by changing the heating temperature in the heat press to 200°C.

[0106] Furthermore, a sample for evaluating 90° peel strength was prepared under the same conditions as in Example 5, except that a rolled copper foil (thickness: 20 μm) and a polyimide film (PI, "Apical" (registered trademark) manufactured by Kaneka Corporation, thickness: 12.5 μm) were used instead of the PET film, resulting in a three-layer structure of "Cu / crosslinked aromatic polyester resin film / PI." For the crosslinked aromatic polyester resin films obtained in Examples 5 and 6, samples were also prepared by changing the heating temperature in the heat press to 200°C.

[0107] The 90° peel strength was measured using a Shimadzu Autograph AG-Xplus at 25°C and a pulling speed of 50 mm / min. Based on the measured 90° peel strength, the adhesiveness of the film was evaluated according to the following criteria. The evaluation results are shown in Table 5 below. Note that "-" means that the test was not performed. <Evaluation criteria> ◎:1.0N / mm or more ○: 0.5N / mm or more and less than 1.0N / mm △: 0.35N / mm or more and less than 0.5N / mm ×: Less than 0.35N / mm

[0108] (Moldability) The obtained crosslinked aromatic polyester resin film (thickness: 0.7 mm) was cut into a sample of 5 mm width x 5 mm length and packed into a mold. The mold was made by cutting an 8 mm diameter circle out of a 1 mm thick Teflon (registered trademark) sheet. Then, pressure and heat were applied using a heat press. The pressure conditions were 4 MPa, and the heating conditions were softening temperature + 30°C for 15 minutes. The moldability was evaluated as ◯ if the crosslinked aromatic polyester resin film piece could be molded into the mold shape, and × if it could not be molded. The evaluation results are shown in Table 5 below. Note that "-" means not performed.

[0109] (Extrusion moldability) 6 g of the obtained crosslinked aromatic polyester resin film (thickness 0.7 mm) was cut into a sample of 5 mm wide x 5 mm long, and the sample was fed into a twin-screw extruder "MiniLab" manufactured by HAAKE in three batches at a barrel temperature of 150 °C and a screw rotation speed of 50 min -1 After the sample was completely charged, the mixture was kneaded for 5 minutes, and then extruded from the barrel. After kneading, if the mixture could be discharged and a filamentous molded product was obtained, the extrusion moldability was evaluated as ◯; if the mixture could not be discharged and a filamentous molded product was not obtained, the extrusion moldability was evaluated as ×. The evaluation results are shown in Table 5 below. Note that "-" means that the experiment was not carried out.

[0110] (solder heat resistance) The resulting crosslinked aromatic polyester resin film was bonded to the shiny side of the rolled copper foil of a 49 μm thick copper-clad laminate (manufactured by Nippon Steel Chemical & Material Co., Ltd., ESPANEX series, Cu / polyimide / Cu=12 μm / 25 μm / 12 μm). 2 The laminate samples were pressed under a pressure of 0.1 MPa for 280 seconds to bond the films together, yielding laminate samples for evaluating solder heat resistance. If the softening temperature of the crosslinked aromatic polyester resin film was 150°C or higher and sufficient adhesion was not achieved at a press temperature of 170°C, the press temperature was increased to 180°C or 200°C to prepare laminate samples. 2.0 cm x 2.0 cm test pieces were cut from the resulting laminate samples and floated for 1 minute in a solder bath with the bath temperature adjusted in 10°C increments from 250°C to 280°C. The upper limit of the temperature at which no blistering occurred was measured. Specifically, the test pieces were floated for 1 minute in a solder bath at 250°C. If no blistering occurred, they were floated for 1 minute in solder baths at 260°C, 270°C, or 280°C, and this process was repeated until blistering occurred. The upper limit of the temperature at which no blistering occurred was measured. The measurement results are shown in Table 5 below. The higher the upper limit temperature at which blistering does not occur, the better the solder heat resistance. For Examples 5 and 6, the solder heat resistance was evaluated for samples fabricated at a press temperature of 170°C and samples fabricated at a press temperature of 200°C.

[0111] (room temperature storage stability) The room temperature storage stability of the resulting crosslinked aromatic polyester resin film was evaluated based on the rate of change in gel fraction and softening behavior.

[0112] (1) Change in gel fraction First, the gel fraction of the resulting crosslinked aromatic polyester resin film was measured by the following method.

[0113] 0.125 g of the resulting crosslinked aromatic polyester resin film was weighed and immersed in 25 mL of methyl ethyl ketone at room temperature for 2 hours. The remaining gel component was then dried in a vacuum dryer at 80°C for 1 hour and its mass was measured. The gel fraction was calculated using the following formula: Gel fraction (%) = (weight of remaining gel component after drying ÷ 0.125) × 100

[0114] Next, the crosslinked aromatic polyester resin film was stored at a constant temperature of 5°C, 25°C, or 40°C for 6 months, and the gel fraction was measured using the method described above after 6 months. The rate of change from the gel fraction at the start of storage was calculated based on the gel fraction at the start of storage and the gel fraction after 6 months of storage. The rate of change was expressed as the absolute value of the difference in gel fraction (%) before and after 6 months, as shown in the following formula. Change rate = gel fraction (%) after 6 months - gel fraction (%) at the start of storage

[0115] A change rate of less than 10% was evaluated as ◯, a change rate of 10% to 25% was evaluated as △, and a change rate of more than 25% was evaluated as ×. The evaluation results are shown in Table 5 below. Note that "-" means that the test was not performed.

[0116] (2) Softening behavior The obtained crosslinked aromatic polyester resin film was stored at 25°C for 6 months, and the presence or absence of softening behavior due to bond exchange reaction was evaluated by stress relaxation measurement. For the stress relaxation measurement, an MCR302 (manufactured by Anton Paar) was used, and stress relaxation tests were performed at temperatures of 100°C, 150°C, and 180°C. The test was performed in a N2 gas atmosphere. The test specimen was a disk-shaped sample with a diameter of 8 mm and a thickness of 0.7 mm cut out from the above crosslinked aromatic polyester resin film.

[0117] After storage at 25°C for six months, samples that showed softening behavior when stress relaxation tests were performed at any of the temperatures of 100°C, 150°C, and 180°C were evaluated as ○, and samples that showed no softening behavior when stress relaxation tests were performed at any of the temperatures of 100°C, 150°C, and 180°C were evaluated as ×. The evaluation results are shown in Table 5 below. The fact that stress relaxation was observed after storage at 25°C for six months indicates that the softening properties due to bond exchange were maintained even after storage, and that there was no change from the initial behavior during long-term storage at room temperature.

[0118] (Solvent resistance) The resulting crosslinked aromatic polyester resin film (0.7 mm thick) was cut into 5 mm wide x 5 mm long samples, and three samples were placed in each screw bottle, one per bottle, for each level. 3 mL of ethanol, dimethylformamide (DMF), or tetrahydrofuran (THF) was added to each bottle and allowed to stand at room temperature for 5 hours. After 5 hours of standing, if there was no change from before immersion, the solvent resistance was evaluated as excellent (◎); if the sample swelled but did not dissolve, the solvent resistance was evaluated as good (○); if the sample dissolved, the solvent resistance was evaluated as poor (×). The evaluation results are shown in Table 5 below. Note that "-" indicates that the test was not performed.

[0119] (90° peel strength when heated) The 90° peel strength during heating was measured for the "Cu / crosslinked aromatic polyester resin film / PI" sample from the above 90° peel strength evaluation samples using a thermostatic chamber (Shimadzu Corporation, Thermostatic Chamber) at a temperature 30°C above the softening temperature of each sample listed in Table 5. The 90° peel strength was measured using a Shimadzu Corporation autograph AG-Xplus at a temperature 30°C above the softening temperature of each sample and a pulling speed of 50 mm / min. Based on the measured 90° peel strength during heating, the peelability of the laminate was evaluated according to the following criteria. The evaluation results are shown in Table 5 below. Note that "-" means not performed. <Evaluation criteria> ◎: Less than 0.35N / mm ○: 0.35N / mm or more and less than 0.5N / mm △: 0.5N / mm or more and less than 1.0N / mm ×: 1.0N / mm or more

[0120] The crosslinked aromatic polyester resin film obtained in Example 1 was chopped into fine resin shapes (5 mm wide x 5 mm long x 0.7 mm thick), melted at 200°C, and extruded into cooling water at a single-hole discharge rate of 1.0 g / min through a 40 cm wide x 4 cm long nozzle with 1.0 mm diameter round solid orifices arranged at 4 mm intervals on the nozzle's effective surface. The film was then solidified. Specifically, cooling water was placed 10 cm below the discharge position, and the film was drawn onto a pair of parallel 50 cm wide stainless steel endless nets spaced 3 cm apart by a pair of take-up conveyors, each partially above the water surface. The net was then fused at the contact points, sandwiched between the two sides, and drawn into the cooling water at a speed of 1.0 m / min for solidification. The film was then dried for 15 minutes in a hot air dryer at 70°C, and cut to the desired size. The resulting film had a thickness of 3 cm and a density of 0.060 g / cm. 3 A network structure of this size was obtained.

[0121] [Table 5-1]

[0122] [Table 5-2]

[0123] [Table 5-3]

[0124] Examples 1, 3, and 4 The crosslinked aromatic polyester resin films of Examples 1, 3, and 4 were systems in which 100 molar parts of carboxy groups in polyester resins (A-1, A-2, A-4) were mixed with 50 molar parts of epoxy compound (B) (carboxy group / epoxy group = 1 / 1 (number of functional groups) per 100 molar parts of carboxy groups) and 20 molar parts of zinc acetate, and exhibited properties such as softening due to ester bond exchange, self-adhesion, remoldability, and scratch repairability.

[0125] Example 2 The crosslinked aromatic polyester resin film of Example 2 was a system in which the amount of zinc acetate used in Example 1 was reduced from 20 parts by mole to 10 parts by mole, and the softening temperature rose from 120° C. to 150° C. It is believed that the amount of transesterification catalyst added was small, which resulted in a decrease in transesterification activity.

[0126] Examples 5 and 6 A trifunctional epoxy or tetrafunctional epoxy was mixed as the epoxy compound (B) into the same polyester resin (A-1) as in Example 1, so that the ratio of carboxy groups to epoxy groups was 1 / 1 (number of functional groups) per 100 mole parts of carboxy groups in the polyester resin (A-1), and the softening temperature was increased by 50°C or more compared to Example 1. It was confirmed that the softening temperature tended to increase as the crosslink density of the resulting crosslinked aromatic polyester resin film increased.

[0127] Examples 7 and 8 The crosslinked aromatic polyester resin films of Examples 7 and 8 were prepared by mixing 100 molar parts of carboxy groups in the polyester resins (A-6 and A-7), 50 molar parts of the epoxy compound (B) (carboxy groups / epoxy groups = 1 / 1 (number of functional groups) per 100 molar parts of carboxy groups), and 20 molar parts of zinc acetate, and exhibited properties such as softening due to ester bond exchange, self-adhesion, remoldability, scratch repairability, and heat resistance.

[0128] The crosslinked aromatic polyester resin films of Examples 1 to 8 had high 90° peel strength and were useful as adhesives. They also had excellent moldability, extrusion moldability, solder heat resistance, room temperature storage stability, and solvent resistance. Furthermore, when heated to a temperature 30°C above the softening temperature, the 90° peel strength was low, indicating that they were easily peeled.

[0129] Comparative Example 1 The polyester resin (A-3) has a polymer structure that does not have carboxyl groups in the side chains, and since carboxyl groups exist only at the terminals, three-dimensional crosslinking did not progress, and its physical properties could not be evaluated.

[0130] Comparative Example 2 The crosslinked aromatic polyester resin composition using polyester resin (A-5) with a very high acid value had a high absorbance ratio and a softening temperature and a 5% weight loss temperature that were almost equal. It is believed that decomposition of the crosslinked aromatic polyester resin progressed near the softening temperature. This indicates that the crosslinked aromatic polyester resin composition had a high absorbance ratio, meaning that a large number of secondary OH groups were generated by the reaction of the carboxyl groups and epoxy groups in the polymer side chains. In other words, it is believed that the crosslinking density of the crosslinked aromatic polyester resin composition was so high that the molecules themselves were less mobile, making it difficult for ester bond exchange to occur.

[0131] Comparative Examples 3, 4, and 5 These are systems that do not contain an ester exchange catalyst (zinc acetate) as in Examples 1, 5, and 6. When only an aromatic polyester resin containing a carboxyl group in the side chain and an epoxy compound were mixed and cured, the crosslinking reaction proceeded, but the ester bond exchange reaction at high temperatures did not proceed, and softening behavior at high temperatures, self-adhesion, remoldability, and scratch repair properties were not exhibited. This is considered to be a typical thermosetting polyester resin. [Industrial Applicability]

[0132] The crosslinked aromatic polyester resin composition of the present invention has heat resistance of 230°C or higher (particularly 300°C or higher), while exhibiting excellent self-adhesiveness, remoldability, and scratch repair properties in a temperature range above its softening temperature, making it particularly useful as a reusable adhesive or coating material.

Claims

1. A crosslinked aromatic polyester resin composition containing a crosslinked aromatic polyester resin (C) and a transesterification catalyst (D), which satisfies the following (1) and (2): A crosslinked aromatic polyester resin composition, wherein the molar ratio of the carboxy groups of an aromatic polyester resin (A) containing carboxy groups in its side chains to the transesterification catalyst (D) (carboxy groups:transesterification catalyst) is 100:10 to 100:

40. (1) The crosslinked aromatic polyester resin (C) is a reaction product of an aromatic polyester resin (A) containing a carboxy group in the side chain and an epoxy compound (B). (2) When the crosslinked aromatic polyester resin composition is measured by infrared spectroscopy, a wave number of 1730 cm originating from an ester bond is detected. －１ The absorbance of the peak (A １７３０ ) The wavenumber of 3200 to 3600 cm due to the hydroxyl group －１ The absorbance of the peak (A ３２００－３６００ ) ratio (A ３２００－３６００ / A １７３０ ) is 0.005 or more and 0.038 or less.

2. 2. The crosslinked aromatic polyester resin composition according to claim 1, wherein the aromatic polyester resin (A) containing a carboxy group in a side chain has an acid value of 5 mgKOH / g or more and 120 mgKOH / g or less.

3. 3. The crosslinked aromatic polyester resin composition according to claim 1, wherein the aromatic polyester resin (A) containing a carboxy group in a side chain has a number average molecular weight of 8,000 or more.

4. 4. The crosslinked aromatic polyester resin composition according to claim 1, wherein the molar ratio of the carboxy groups in the aromatic polyester resin (A) containing a carboxy group in a side chain to the epoxy groups in the epoxy compound (B) (carboxy groups:epoxy groups) is 100:50 to 100:

150.

5. 5. The crosslinked aromatic polyester resin composition according to claim 1, wherein the epoxy compound (B) has a number average molecular weight of 100 or more and 500 or less.

6. The method includes a step of mixing an aromatic polyester resin (A) having an acid value of 5 mgKOH / g or more and 120 mgKOH / g or less and containing a carboxy group in a side chain, an epoxy compound (B), and an ester exchange catalyst (D), and heating the mixture to crosslink the mixture; A method for producing a crosslinked aromatic polyester resin composition, wherein the molar ratio of the transesterification catalyst (D) to the carboxy groups of the aromatic polyester resin (A) containing carboxy groups in its side chains (carboxy groups:transesterification catalyst) is 100:10 to 100:

40.

7. A self-adhesive comprising the crosslinked aromatic polyester resin composition according to any one of claims 1 to 5.

8. A self-repairing material containing a crosslinked aromatic polyester resin composition comprising a crosslinked aromatic polyester resin (C) and an ester exchange catalyst (D), and satisfying the following (1) to (2): (1) The crosslinked aromatic polyester resin (C) is a reaction product of an aromatic polyester resin (A) containing a carboxy group in the side chain and an epoxy compound (B). (2) When the crosslinked aromatic polyester resin composition is measured by infrared spectroscopy, the ratio (A 3200-3600 / A 1730 ) of the absorbance (A 1730 ) of the peak at a wavenumber of about 1730 cm −1 attributable to the ester bond to the absorbance (A 3200-3600 ) of the peak at a wavenumber of about 3200 to 3600 cm −1 attributable to the hydroxyl group is 0.005 or more and 0.038 or less.

9. A molding material containing a crosslinked aromatic polyester resin composition comprising a crosslinked aromatic polyester resin (C) and an ester exchange catalyst (D), and satisfying the following (1) to (2): (1) The crosslinked aromatic polyester resin (C) is a reaction product of an aromatic polyester resin (A) containing a carboxy group in the side chain and an epoxy compound (B). (2) When the crosslinked aromatic polyester resin composition is measured by infrared spectroscopy, the ratio (A 3200-3600 / A 1730 ) of the absorbance (A 1730 ) of the peak at a wavenumber of about 1730 cm −1 attributable to the ester bond to the absorbance (A 3200-3600 ) of the peak at a wavenumber of about 3200 to 3600 cm −1 attributable to the hydroxyl group is 0.005 or more and 0.038 or less.

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