Method for decomposing acid anhydride epoxy cured products, and polyols and thermosetting resins prepared thereby

Abstract

The present invention provides a method for decomposing an acid anhydride epoxy cured product, and a polyol and a thermosetting resin prepared thereby. [Solution] The method for decomposing a cured acid anhydride epoxy product includes a mixing step of mixing a cured acid anhydride epoxy product with an alcohol amine compound to form a decomposition system, where the alcohol amine compound has the structure shown in formula (I), and each symbol in formula (I) is defined in the specification; and a decomposition step of heating the decomposition system to a decomposition temperature to decompose the cured acid anhydride epoxy product to form a polyol. In this way, the cured acid anhydride epoxy product is decomposed by heating with the alcohol amine compound, and the resulting polyol can be used to prepare an unsaturated polyester resin, thereby achieving the goal of recycling and recovery.

Description

[Technical Field]

[0001] The present invention relates to a method for decomposing a cured material, particularly a method for decomposing an acid anhydride epoxy cured material, and to a polyol and a thermosetting resin prepared thereby. [Background technology]

[0002] Thermosetting materials have advantages such as excellent resin processability before curing and excellent thermal stability, mechanical strength, and chemical resistance after crosslinking and curing, making them widely used in various fields, and are often used in fiber composite materials that require high strength and light weight. However, the inability to be reprocessed and the good chemical resistance of thermosetting materials themselves make them difficult to recover and reuse after disposal. Furthermore, the combustion of fiber composite materials tends to shorten the life of firing equipment and cause large-scale waste problems. Therefore, how to dispose of discarded thermosetting materials is a key improvement goal in the current environmental protection agenda. Summary of the Invention [Problem to be solved by the invention]

[0003] Currently, epoxy resin is one of the most popular thermosetting resins, with a wide design space for physical properties. By combining different types of curing agents, it is possible to meet a variety of molding conditions and physical property requirements. However, after mixing various curing agents with the epoxy cured material, a stable covalent network bond is formed, which makes it difficult to reprocess or recover for secondary applications.

[0004] Among the many types of hardeners, acid anhydrides are a common combination used in traditional pultruded carbon fiber composites. After crosslinking, they generate ester bonds, which can lead to structural decomposition through transesterification or hydrolysis, ultimately achieving the goal of decomposing the composite. However, this method has problems such as residual catalyst and poor conversion efficiency. In addition, alkaline catalysts can also be used to promote the hydrolysis of ester bonds in the resin, but this decomposition method generates wastewater and causes secondary pollution to the environment.

[0005] In view of this, in order to achieve the effects of a circular economy, related businesses have been striving to find ways to decompose cured epoxy resins and recover and reuse the decomposed products. [Means for solving the problem]

[0006] One object of the present invention is to provide a method for decomposing a cured acid anhydride epoxy material and a polyol prepared thereby. The cured acid anhydride epoxy material is decomposed by heating with an alcohol amine compound, and the resulting product is an amide- or urea-containing polyol.

[0007] Another object of the present invention is to provide a thermosetting resin, in which polyol, which is the decomposition product of acid anhydride epoxy cured product, can be used to prepare the thermosetting resin, thereby achieving the purpose of recycling and recovery.

[0008] According to one embodiment of the present invention, a mixing step of mixing an acid anhydride epoxy cured product and an alcohol amine compound to form a decomposition system, wherein the alcohol amine compound has a structure represented by formula (I): [ka] The present invention provides a method for decomposing a cured acid anhydride epoxy material, the method comprising: a mixing step in which R2's are each independently a methyl group or a hydrogen atom, and p is an integer of 0 to 6; and a decomposition step in which the decomposition system is heated to a decomposition temperature to decompose the cured acid anhydride epoxy material and form a polyol.

[0009] The method for decomposing a cured acid anhydride epoxy material described in the previous paragraph may further include a step of synthesizing a cured acid anhydride epoxy material by reacting an epoxy compound represented by formula (II) or / and an epoxy compound represented by formula (III) with an acid anhydride compound represented by formula (IV). [ka]

[0010] X's each independently represent an alkyl chain having 1 to 12 carbon atoms or a structure represented by formula (A) or formula (B), [ka] R1's each independently represent an alkyl group having 1 to 4 carbon atoms, a methoxy group, a nitro group, or a halogen atom; a is an integer of 0 to 4; n and q are integers of 0 to 10; Y's each independently represent a single bond, or a structure represented by formula (i), formula (ii), formula (iii), formula (iv), formula (v), formula (vi), formula (vii), formula (viii), formula (ix), or formula (x); [ka] X1 and X2 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aromatic group having 6 to 12 carbon atoms; Z each independently represent an alkyl chain having 1 to 12 carbon atoms, an ortho-phenylene group, a meta-phenylene group, a para-phenylene group, or a structure represented by formula (xi) or formula (xii); [ka] t is an integer of 1 to 6, and Ar is a single bond, a double bond, or a structure represented by formula (a), formula (b), formula (c), or formula (d). [ka]

[0011] According to the method for decomposing an acid anhydride epoxy cured product described in the previous paragraph, the decomposition temperature may be 80°C to 180°C.

[0012] According to the method for decomposing an acid anhydride epoxy cured product described in the previous paragraph, the decomposition temperature may be 100°C to 150°C.

[0013] According to the method for decomposing an acid anhydride epoxy cured material described in the previous paragraph, in the decomposition step, the decomposition system is heated to a decomposition temperature and then maintained for a decomposition time which may be 5 to 600 minutes.

[0014] According to the method for decomposing an acid anhydride epoxy cured product described in the previous paragraph, the decomposition time may be 360 ​​minutes to 480 minutes.

[0015] According to the method for decomposing an acid anhydride epoxy cured material described in the previous paragraph, the polyol may include at least one of the structures shown in formula (V), formula (VI), formula (VII), and formula (VIII). [ka]

[0016] According to the method for decomposing an acid anhydride epoxy cured product described in the previous paragraph, the weight ratio of the alcohol amine compound to the acid anhydride epoxy cured product may be 5:1 to 20:1.

[0017] According to the method for decomposing a cured acid anhydride epoxy material described in the previous paragraph, the weight ratio of the alcohol amine compound to the cured acid anhydride epoxy material may be 10:1.

[0018] Another embodiment of the present invention provides a polyol prepared by the decomposition method of the acid anhydride epoxy cured material.

[0019] Yet another embodiment of the present invention provides a thermoset resin prepared by adding said polyol to the resin reactants.

[0020] According to the thermosetting resin described in the previous paragraph, the thermosetting resin may be an unsaturated polyester resin.

[0021] In accordance with the thermosetting resin described in the previous paragraph, the resin reactants may include propylene glycol, diethylene glycol, benzoquinone, phthalic anhydride, maleic anhydride, and styrene.

[0022] According to the thermosetting resin described in the previous paragraph, the amount of polyol added may be 1% to 30% by weight of the total content of the resin reactant and the polyol.

[0023] According to the thermosetting resin described in the previous paragraph, the amount of polyol added may be 5% to 15% by weight of the total content of the resin reactant and the polyol. [Effects of the Invention]

[0024] Therefore, the method for decomposing the cured epoxy anhydride material of the present invention mainly involves heating the cured epoxy anhydride material with an alcohol amine compound to dissolve the cured epoxy anhydride material, thereby obtaining a polyol having an amide or urea structure, which can be used to prepare a thermosetting resin, thereby achieving the purpose of recycling and recovery. [Brief explanation of the drawings]

[0025] To make the above and other objects, features, advantages and embodiments of the present invention more clear and understandable, the drawings are described as follows. [Figure 1] 1 is a process flowchart of a method for decomposing a cured acid anhydride epoxy material according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] Each embodiment of the present invention will be discussed in more detail below. However, the embodiments are applications of various inventive concepts and may be specifically implemented within a variety of different specific scopes. The specific embodiments are for illustrative purposes only and are not intended to be limiting in scope.

[0027] In the present invention, the compound structure may be represented by a skeleton formula, and such a representation may omit carbon atoms, hydrogen atoms, and hydrocarbon bonds. If the structural formula clearly depicts functional groups, the drawing shall be used as the basis.

[0028] In the present invention, for the sake of brevity and simplicity, "an alcoholamine compound having a structure represented by formula (I)" may be expressed as an alcoholamine compound represented by formula (I) or alcoholamine compound (I), and other compound or group representations may be inferred as follows:

[0029] <Method for decomposing acid anhydride epoxy cured products> Please also refer to Figure 1, which is a process flow chart of a method 100 for decomposing a cured acid anhydride epoxy material according to one embodiment of the present invention. In Figure 1, the method 100 for decomposing a cured acid anhydride epoxy material includes steps 110 and 120.

[0030] Step 110 is a mixing step of mixing an acid anhydride epoxy cured product and an alcohol amine compound to form a decomposition system, and the alcohol amine compound has a structure shown in formula (I): [ka] R2's each independently represent a methyl group or a hydrogen atom, and p represents an integer of 0-6.

[0031] Step 120 is a decomposition step in which the decomposition system is heated to a decomposition temperature to decompose the acid anhydride epoxy cured product to form a polyol, and the decomposition temperature may be 80° C. to 180° C., and preferably 100° C. to 150° C. In particular, after the decomposition system is heated to the decomposition temperature, it can be maintained for a decomposition time, which may be 5 minutes to 600 minutes, and preferably 360 minutes to 480 minutes.

[0032] Furthermore, the method 100 for decomposing a cured acid anhydride epoxy material of the present invention may further include, before the mixing step, a step of synthesizing a cured acid anhydride epoxy material by reacting an epoxy compound represented by formula (II) and / or an epoxy compound represented by formula (III) with an acid anhydride compound represented by formula (IV). [ka]

[0033] X's each independently represent an alkyl chain having 1 to 12 carbon atoms or a structure represented by formula (A) or formula (B), [ka] R1's each independently represent an alkyl group having 1 to 4 carbon atoms, a methoxy group, a nitro group, or a halogen atom, a represents an integer of 0 to 4, and n and q represent integers of 0 to 10. Y's each independently represent a single bond, or a structure represented by formula (i), formula (ii), formula (iii), formula (iv), formula (v), formula (vi), formula (vii), formula (viii), formula (ix), or formula (x), [ka] X1 and X2 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aromatic group having 6 to 12 carbon atoms. Z each independently represent an alkyl chain having 1 to 12 carbon atoms, an ortho-phenylene group, a meta-phenylene group, a para-phenylene group, or a structure represented by formula (xi) or formula (xii), [ka] t is an integer of 1 to 6. Ar is a single bond, a double bond, or a structure represented by formula (a), formula (b), formula (c), or formula (d), [ka] In detail, the present invention provides a method for curing an epoxy compound represented by formula (II), an epoxy compound represented by formula (III), or a mixture of epoxy compounds represented by formulas (II) and (III), with an acid anhydride compound represented by formula (IV) to form an acid anhydride epoxy cured product, and then heating the acid anhydride epoxy cured product with an alcohol amine compound represented by formula (I) to cause a decomposition reaction. The polyol obtained after the decomposition may contain at least one of the structures represented by formulas (V), (VI), (VII), and (VIII).

[0034] [ka] The definitions of X, Ar, R2, and p are as defined above and will not be explained here. The weight ratio of the alcohol amine compound to the acid anhydride epoxy cured product may be 5:1 to 20:1, and is preferably 10:1.

[0035] Specifically, an acid anhydride epoxy cured product synthesized from an epoxy compound represented by formula (II) can form polyols including those represented by formulas (V), (VI), and (VII) after decomposition; an acid anhydride epoxy cured product synthesized from an epoxy compound represented by formula (III) can form polyols including those represented by formulas (VI) and (VIII) after decomposition; and an acid anhydride epoxy cured product synthesized from a mixed epoxy compound of formulas (II) and (III) can form polyols including those represented by formulas (V), (VI), (VII), and (VIII) after decomposition.

[0036] For example, in the epoxy compounds represented by formula (II) and formula (III), when X is the structure represented by formula (A), n and a are 0, Y is the structure represented by formula (i), and X1 and X2 are methyl groups, the epoxy compounds have the structures represented by formula (II-a) and formula (III-a). [ka]

[0037] Furthermore, in the acid anhydride compound represented by formula (IV), when Ar has the structure represented by formula (d), the acid anhydride compound is methylhexahydroanhydride (MHHPA), and in the alcohol amine compound represented by formula (I), when R2 is a hydrogen atom and p is 0, the alcohol amine compound is ethanolamine. As a result, after decomposing the acid anhydride epoxy cured product synthesized from the epoxy compounds represented by formulas (II-a) and (III-a) and methylhexahydroanhydride with ethanolamine, polyols including those represented by formulas (Va), (VI-a), (VII-a), and (VIII-a) can be obtained. [ka]

[0038] In addition, in the epoxy compound represented by formula (III), when X is the structure represented by formula (B), q is 0, and Z is an alkyl chain having 4 carbon atoms, the epoxy compound has a structure represented by formula (III-b). [ka]

[0039] In this way, after the acid anhydride epoxy cured product synthesized from the epoxy compound represented by formula (III-b) and methylhexahydroanhydride is decomposed with ethanolamine, polyols including those represented by the above formulas (VI-a) and (VIII-b) can be obtained. [ka]

[0040] The present invention further provides a polyol containing an amide or urea structure, which includes at least one of the structures represented by formula (V), formula (VI), formula (VII), and formula (VIII), obtained by heating and decomposing a mixture of a cured acid anhydride epoxy material and an alcohol amine compound using the above-mentioned method 100 for decomposing a cured acid anhydride epoxy material.

[0041] <Thermosetting resin> The present invention also provides a thermosetting resin prepared by adding a polyol prepared by the method 100 for decomposing a cured acid anhydride epoxy material to a resin reactant. Specifically, the amount of polyol added may be 1% to 30% by weight, preferably 5% to 15% by weight, of the total content of the resin reactant and polyol, so as not to affect the basic physical properties of the resin. For details about polyols, please refer to the above and will not be described in detail here. Furthermore, since the thermosetting resin of the present invention may be an unsaturated polyester resin, the resin reactant may include propylene glycol, diethylene glycol, benzoquinone, phthalic anhydride, maleic anhydride, and styrene. However, the type of thermosetting resin and its resin reactant are not limited to the disclosed contents. If necessary, a different resin reactant can be cured with the polyol obtained by the method 100 for decomposing a cured acid anhydride epoxy material of the present invention to form a desired thermosetting resin. Thus, the polyol obtained by the method 100 for decomposing a cured acid anhydride epoxy material of the present invention can be used to produce a thermosetting resin, thereby achieving the goal of recycling and recovery.

[0042] In order to facilitate the skilled artisan's understanding, the present invention will now be further illustrated by the following specific examples, which will enable one to fully utilize and practice the present invention without the need for undue interpretation, and which should not be construed as limiting the scope of the invention, but rather serve to illustrate materials and methods of how to practice the invention. [Example]

[0043] <Examples / Comparative Examples> <Decomposed acid anhydride epoxy cured product> Example 1: An acid anhydride epoxy cured product obtained by curing an epoxy resin mixture of formula (II-a) and formula (III-a) with methylhexahydroanhydride was heated to 150°C with ethanolamine. The amount of ethanolamine used was 10 times the weight ratio of the acid anhydride epoxy cured product, and the reaction time was 6 hours. After the acid anhydride epoxy cured product was completely dissolved, the ethanolamine was extracted by vacuum concentration, and finally a polyol containing the compounds represented by formula (Va), formula (VI-a), formula (VII-a), and formula (VIII-a) (active hydrogen equivalent HEW = 147.98 g / eq) was obtained.

[0044] Example 2: An acid anhydride epoxy cured product obtained by curing an epoxy compound represented by formula (III-b) with methylhexahydroanhydride was heated to 150°C with ethanolamine. The amount of ethanolamine used was 10 times the weight ratio of the acid anhydride epoxy cured product, and the reaction time was 6 hours. After the acid anhydride epoxy cured product was completely dissolved, the mixture was concentrated under reduced pressure to extract the ethanolamine, and finally a polyol containing compounds represented by formulas (VI-a) and (VIII-b) (active hydrogen equivalent HEW = 103.12 g / eq) was obtained.

[0045] Comparative Example 1: A cured acid anhydride epoxy product obtained by curing a commercially available o-cresol novolac epoxy resin (purchased from Changchun Resin, product code CNE220) with methylhexahydroanhydride was heated to 150°C with ethanolamine. The amount of ethanolamine used was 10 times the weight ratio of the cured acid anhydride epoxy product, and the reaction time was 6 hours. During this time, the cured acid anhydride epoxy product was not completely dissolved.

[0046] Comparative Example 2: Ethylene glycol and titanium n-butoxide (Ti(OBu)4) were added as a transesterification catalyst to an acid anhydride epoxy cured product obtained by curing an epoxy resin mixture consisting of formula (II-a) and formula (III-a) with methylhexahydroanhydride, and the mixture was heated to 150°C. The amount of ethylene glycol used was 10 times the weight ratio of the acid anhydride epoxy cured product, and the reaction time was 6 hours. At this time, the acid anhydride epoxy cured product was not completely dissolved.

[0047] Comparative Example 3: Ethylene glycol and 3-picoline were added to an acid anhydride epoxy cured product obtained by curing an epoxy resin mixture consisting of formula (II-a) and formula (III-a) with methylhexahydroanhydride, and the mixture was heated to 150°C. The amount of ethylene glycol used was 10 times the weight ratio of the acid anhydride epoxy cured product, and the reaction time was 6 hours. At this time, the acid anhydride epoxy cured product was not completely dissolved.

[0048] The remaining weights (%) of Examples 1 and 2 and Comparative Examples 1 to 3 of the present application after reacting for 6 hours are listed in Table 1 below.

[0049] [Table 1]

[0050] As can be seen from the results in Table 1, in Examples 1 and 2, linear epoxy compounds of different structures were cured to form acid anhydride epoxy cured products, which were then thermally decomposed with an alcohol amine compound. All were completely decomposed at 150°C, demonstrating excellent decomposition effects. However, as shown in Comparative Example 1, when the linear epoxy compound was replaced with a nonlinear multifunctional epoxy resin (CNE) and then heat-treated with an alcohol amine compound, no complete decomposition product was obtained, making subsequent applications difficult. Furthermore, in order to decompose an acid anhydride epoxy cured product into an alcohol-based mixture, theoretically, it can also be achieved by a dialcohol-based transesterification reaction, in addition to heating with an alcohol amine compound according to the present invention. However, as shown in Table 1, in Comparative Examples 2 and 3, after treatment at 150°C for 6 hours using a combination of ethylene glycol and an alkali catalyst or a transesterification catalyst, no significant decomposition effect was observed in either of the acid anhydride epoxy cured products, demonstrating the advantages of using an alcohol amine compound to decompose an acid anhydride epoxy cured product according to the present invention.

[0051] <Preparation of Unsaturated Polyester Resin> Example 3: 160.82 grams of the polyol obtained in Example 1, 59.05 grams of propylene glycol, 29.11 grams of diethylene glycol, 0.052 grams of benzoquinone, 110 grams of phthalic anhydride, and 82.83 grams of maleic anhydride were mixed, heated to 100°C and stirred for 10 minutes, heated to 210°C and distilled (vacuum distillation) to remove excess alcohol amine compound, mixed with the polyol, propylene glycol, diethylene glycol, benzoquinone, phthalic anhydride, and maleic anhydride, and reacted for 8 hours. After that, the acid value was found to be less than 35 mg KOH / g, and 214.99 grams of styrene was added to dilute, and the unsaturated polyester resin of Example 3 was obtained.

[0052] Example 4: 67.64 grams of the polyol obtained in Example 1, 63.05 grams of propylene glycol, 31.52 grams of diethylene glycol, 0.052 grams of benzoquinone, 110 grams of phthalic anhydride, and 82.83 grams of maleic anhydride were mixed, heated to 100°C and stirred for 10 minutes, heated to 210°C and distilled (vacuum distillation) to remove excess alcohol amine compound, and the polyol, propylene glycol, diethylene glycol, benzoquinone, phthalic anhydride, and maleic anhydride were mixed and reacted for 8 hours. After that, the acid value was found to be less than 35 mg KOH / g, and 214.99 grams of styrene was added to dilute, and the unsaturated polyester resin of Example 4 was obtained.

[0053] Comparative Example 4: 201.06 grams of the polyol obtained in Example 1, 12.94 grams of propylene glycol, 6.47 grams of diethylene glycol, 0.052 grams of benzoquinone, 110 grams of phthalic anhydride, and 82.83 grams of maleic anhydride were mixed, heated to 100°C and stirred for 10 minutes, heated to 210°C and distilled (vacuum distillation) to remove excess alcohol amine compound, and then mixed with the polyol, propylene glycol, diethylene glycol, benzoquinone, phthalic anhydride, and maleic anhydride, reacted for 8 hours, and then found that the acid value was less than 35 mgKOH / g. 214.99 grams of styrene diluent was added to obtain the unsaturated polyester resin of Comparative Example 4.

[0054] Comparative Example 5: 88.94 grams of propylene glycol, 44.47 grams of diethylene glycol, 0.052 grams of benzoquinone, 110 grams of phthalic anhydride, and 82.83 grams of maleic anhydride were mixed, heated to 100°C and stirred for 10 minutes, heated to 210°C and distilled, and reacted for 8 hours. After that, the acid value was found to be less than 35 mg KOH / g, and 214.99 grams of styrene was added to dilute, to obtain the unsaturated polyester resin of Comparative Example 5.

[0055] In addition, 1 phr of MEKPO peroxide and 1 phr of cobalt octanoate were added to each of the unsaturated polyester resins of Examples 3, 4, and Comparative Examples 4 and 5, and the mixture was stirred uniformly. The mixture was poured into a mold and cured at room temperature for 12 hours, and then at 80°C for 4 hours, after which the physical properties were evaluated.

[0056] <Thermal characteristic evaluation> The thermal properties of Examples 3 and 4 and Comparative Examples 4 and 5 were evaluated, and the glass transition temperature (T g ) and measure T g (°C) The measurement results are listed in Table 2 below.

[0057] [Table 2]

[0058] As can be seen from the results in Table 2, the polyols in Examples 3 and 4, which had an addition rate of less than 30 wt%, exhibited physical properties similar to those of Comparative Example 5, which had no polyol added, and were able to meet industry application standards (glass transition temperature greater than 60°C). On the other hand, the polyol in Comparative Example 4, which had an addition rate of more than 30 wt%, exhibited significantly reduced physical properties, and its heat resistance could not meet industry needs.

[0059] As described above, in the present invention, the acid anhydride epoxy cured product obtained by curing a linear epoxy compound structure with an acid anhydride compound is decomposed by heating with an alcohol amine compound, and the polyol obtained by the decomposition can be introduced into the synthesis of an unsaturated polyester resin, and can be used as a raw material for the subsequent synthesis of an unsaturated polyester resin without washing or purification. In addition, the raw material for the decomposition product can be obtained by recovering the acid anhydride epoxy cured product, which is advantageous in terms of industrial cost and contributes significantly to the recovery and reuse of resins.

[0060] Although the present invention has been disclosed in the above embodiments, the above embodiments are not used to limit the present invention, and anyone skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, so the scope of protection of the present invention should be based on what is defined in the claims. [Explanation of symbols]

[0061] 100: Decomposition method for acid anhydride epoxy cured material 110, 120: Process

Claims

1. A mixing step of mixing an acid anhydride epoxy cured product with an alcohol amine compound to form a decomposition system, wherein the alcohol amine compound has a structure represented by formula (I), 【Chemical 1】 R ２ are each independently a methyl group or a hydrogen atom, and p is an integer of 0 to 6; a decomposition step of heating the decomposition system to a decomposition temperature to decompose the acid anhydride epoxy cured product to form a polyol; A method for decomposing a cured acid anhydride epoxy material comprising:

2. The method further includes a step of synthesizing an acid anhydride epoxy cured product by reacting an epoxy compound represented by formula (II) or / and an epoxy compound represented by formula (III) with an acid anhydride compound represented by formula (IV), 【Chemistry 2】 X's each independently represent an alkyl chain having 1 to 12 carbon atoms or a structure represented by formula (A) or formula (B), 【Chemistry 3】 R １ are each independently an alkyl group having 1 to 4 carbon atoms, a methoxy group, a nitro group, or a halogen atom; a is an integer of 0 to 4; n and q are integers of 0 to 10; Y's each independently represent a single bond, or a structure represented by formula (i), formula (ii), formula (iii), formula (iv), formula (v), formula (vi), formula (vii), formula (viii), formula (ix), or formula (x), 【Chemistry 4】 X １ and X ２ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aromatic group having 6 to 12 carbon atoms, Z's each independently represent an alkyl chain having 1 to 12 carbon atoms, an ortho-phenylene group, a meta-phenylene group, a para-phenylene group, or a structure represented by formula (xi) or formula (xii), 【Chemistry 5】 t is an integer from 1 to 6, Ar is a single bond, a double bond, or a structure represented by formula (a), formula (b), formula (c), or formula (d). 【Chemistry 6】 The method for decomposing an acid anhydride epoxy cured product according to claim 1.

3. 2. The method for decomposing a cured acid anhydride epoxy material according to claim 1, wherein the decomposition temperature is 80°C to 180°C.

4. The method for decomposing a cured acid anhydride epoxy material according to claim 3, wherein the decomposition temperature is 100°C to 150°C.

5. 2. The method for decomposing an acid anhydride-epoxy cured material according to claim 1, wherein in the decomposition step, the decomposition system is heated to the decomposition temperature and then maintained for a decomposition time of 5 to 600 minutes.

6. The method for decomposing a cured acid anhydride epoxy material according to claim 5, wherein the decomposition time is 360 to 480 minutes.

7. 2. The method for decomposing a cured acid anhydride epoxy material according to claim 1, wherein the polyol contains at least one of the structures shown in formula (V), formula (VI), formula (VII), and formula (VIII). 【Chemistry 7】

8. 2. The method for decomposing a cured acid anhydride epoxy material according to claim 1, wherein a weight ratio of the alcohol amine compound to the cured acid anhydride epoxy material is 5:1 to 20:

1.

9. 9. The method for decomposing a cured acid anhydride epoxy material according to claim 8, wherein the weight ratio of the alcohol amine compound to the cured acid anhydride epoxy material is 10:

1.

10. A polyol prepared by the method for decomposing an acid anhydride epoxy cured product according to any one of claims 1 to 9.

11. A thermosetting resin prepared by adding the polyol of claim 10 to a resin reactant.

12. The thermosetting resin of claim 11, wherein the thermosetting resin is an unsaturated polyester resin.

13. 13. The thermoset of claim 12, wherein the resin reactants include propylene glycol, diethylene glycol, benzoquinone, phthalic anhydride, maleic anhydride, and styrene.

14. The thermosetting resin according to claim 11, wherein the amount of the polyol added is 1% by weight to 30% by weight of the total content of the resin reactant and the polyol.

15. The thermosetting resin according to claim 14, wherein the amount of the polyol added is 5% by weight to 15% by weight of the total content of the resin reactant and the polyol.

Images