Polymer, crosslinked body, electric wire, wiring harness, method for producing polymer, and method for producing crosslinked body

Abstract

Provided are a polymer formed using an epoxy monomer and a crosslinked object formed using an epoxy-modified polymer, which are excellent in terms of convenience of molding and heat resistance and suitable for removably covering metal surfaces. Also provided are an electric wire and a wire harness which are obtained using such polymer and crosslinked object and methods for producing such polymer and crosslinked object.　The polymer includes a structure of formula (1) and has a flow initiation temperature of 150°C or higher. Extract water obtained by immersing the polymer in a ten-fold amount of pure water at 120°C for 24 hours has an acidity pH of 4-9. In formula (1), R1 is an organic group and n is an integer of 2 or larger.

Description

[Technical Field]

[0001] The present disclosure relates to a polymer, a crosslinked body, an electric wire, a wire harness, a method for producing a polymer, and a method for producing a crosslinked body. [Background technology]

[0002] In insulated wires and wiring harnesses, thermoplastic polymer materials are often used as insulating coatings that cover the outer periphery of conductors. When molding a thermoplastic polymer material into a desired shape, it is heated to make it fluid, and then a molding method such as extrusion molding is applied. To easily perform molding by heating, it is preferable that the polymer material acquires fluidity without being heated to an extremely high temperature.

[0003] On the other hand, insulated wires and wiring harnesses, the temperature rises when electricity is passed through them, so the polymer materials placed near the current-carrying parts, including the insulating coating, are required to have high heat resistance. In other words, the polymer materials must not undergo irreversible deformation due to heat generated when electricity is passed through them. For example, the insulating coating of electric wires for automobiles is required to withstand temperatures of 150°C or less. No It is desirable that no reversible deformation occurs.

[0004] Thus, polymer materials used in insulated wires and wiring harnesses are required to be relatively easily moldable by heating and to have high heat resistance after molding. To achieve both of these properties, a method is used in which unpolymerized monomer material is placed in a predetermined position to form a desired shape, and then the monomer material is polymerized. Another method is to mold an uncrosslinked polymer material into a desired shape by extrusion molding or the like, and then crosslink the molecular chains to improve heat resistance.

[0005] As described above, examples of materials that are arranged in a predetermined position and then polymerized or crosslinked to form insulated wires or wiring harnesses include epoxy monomers and epoxy-modified polymers. Polymerization of the epoxy monomers and crosslinking of the epoxy-modified polymers proceed through a ring-opening polymerization reaction of the epoxy groups. For example, Patent Document 1 listed below describes a form in which an epoxy resin composition is crosslinked and used for wire coating. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-89078 Summary of the Invention [Problem to be solved by the invention]

[0007] As described above, it is possible to achieve both moldability and heat resistance by utilizing the polymerization of epoxy monomers and the crosslinking of epoxy-modified polymers. However, the polymerization of epoxy monomers and the crosslinking of epoxy-modified polymers require ring-opening polymerization of epoxy groups, and conventionally, ring-opening polymerization of epoxy groups has generally been achieved by addition polymerization using a curing agent or cationic polymerization using an initiator.

[0008] In the addition polymerization of epoxy compounds, as disclosed in Patent Document 1, polymerization proceeds by adding a curing agent, such as an amine compound, a thiol-containing compound, a hydroxyl-containing compound, or an acid anhydride, to the epoxy group. Because hydroxyl groups are generated during this addition polymerization, if the addition polymerization is performed on the surface of a metal material, such as a conductor, the epoxy polymer adheres to the metal surface via the hydroxyl groups, making peeling difficult. This makes it difficult to apply to applications requiring peeling, such as wire coating. Furthermore, when using addition polymerization, the curing agent must be added in an equimolar amount to the epoxy group, or in an amount close to that amount. Even at relatively low temperatures, such as room temperature, the addition polymerization proceeds immediately after the addition of the curing agent. Therefore, preparation is required before use, and controlling the polymerization rate is difficult. Therefore, the molding convenience is not excellent.

[0009] On the other hand, in the cationic polymerization of epoxy compounds, acidic initiators such as photoacid generators or Lewis acids are used. In this case, hydroxyl groups are not generated, so adhesion to metal surfaces does not occur as in addition polymerization. However, since acid remains in the material after cationic polymerization, it may cause corrosion of the metal material, making it difficult to apply to applications that come into contact with metal materials.

[0010] In view of the above, an object of the present invention is to provide a polymer formed using an epoxy monomer and a crosslinked body formed using an epoxy-modified polymer, which are easy to mold and have excellent heat resistance, and are suitable for peelably coating metal surfaces, and also to provide an electric wire and a wiring harness using such a polymer and crosslinked body, and further to provide a method for producing such a polymer and crosslinked body. [Means for solving the problem]

[0011] The polymer of the present disclosure comprises a structure of the following formula (1), has a flow initiation temperature of 150°C or higher, and has an acidity of pH 4 or higher and 9 or lower when extracted with water obtained by immersing the polymer in 10 times its amount of pure water at 120°C for 24 hours. [ka] Here, R1 is an organic group, and n is an integer of 2 or more.

[0012] The crosslinked body of the present disclosure comprises the structure of the following formula (3), has a flow-initiation temperature of 150°C or higher, and has an acidity of pH 4 or higher and 9 or lower in the extract obtained by immersing the crosslinked body in 10 times the amount of pure water at 120°C for 24 hours. [ka] Here, R2 is a polymer chain, and n is an integer of 2 or more.

[0013] The electric wire of the present disclosure has a conductor made of metal and an insulating coating that contains the polymer or the crosslinked body and coats the outer periphery of the conductor.

[0014] The wire harness of the present disclosure includes the polymer or the crosslinked body.

[0015] In the method for producing a polymer according to the present disclosure, a composition containing an epoxy monomer of the following formula (2) and a fatty acid salt is heated to cause a polymerization reaction, thereby producing the polymer. [ka]

[0016] In the method for producing a crosslinked body of the present disclosure, a composition containing an epoxy-modified polymer of the following formula (4) and a fatty acid salt is heated to cause a crosslinking reaction, thereby producing the crosslinked body. [ka] [Effects of the Invention]

[0017] The polymer and crosslinked body of the present disclosure are polymers formed using epoxy monomers and crosslinked bodies formed using epoxy-modified polymers, and are polymers and crosslinked bodies that are easy to mold and have excellent heat resistance, and are suitable for peelably coating metal surfaces. Furthermore, the electric wire, wire harness, method for producing a polymer, and method for producing a crosslinked body of the present disclosure are electric wires and wire harnesses using such polymers and crosslinked bodies, and methods for producing such polymers and crosslinked bodies. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a diagram illustrating the mechanism of polymer formation according to one embodiment of the present disclosure. [Figure 2] FIG. 2 is a perspective view showing the structure of an electric wire according to one embodiment of the present disclosure. [Figure 3]Figure 3 shows the infrared absorption spectrum of the material corresponding to sample A5, where (i) shows the state of the epoxy compound (OD-ep) alone before heating, (ii) shows the state after heating, (iii) shows the state of the mixed solution with the fatty acid salt (st-Mg) before heating, and (iv) shows the state of the mixed solution after heating. DETAILED DESCRIPTION OF THE INVENTION

[0019] [Description of the embodiments of the present disclosure] First, embodiments of the present disclosure will be listed and described.

[0020] The polymer of the present disclosure comprises a structure of the following formula (1), has a flow initiation temperature of 150°C or higher, and has an acidity of pH 4 or higher and 9 or lower when extracted with water obtained by immersing the polymer in 10 times its amount of pure water at 120°C for 24 hours. [ka] Here, R1 is an organic group, and n is an integer of 2 or more.

[0021] The structure of the above formula (1) can be formed by ring-opening polymerization of an epoxy monomer of the following formula (2) with a fatty acid salt. [ka]

[0022] The crosslinked body of the present disclosure comprises the structure of the following formula (3), has a flow-initiation temperature of 150°C or higher, and has an acidity of pH 4 or higher and 9 or lower in the extract obtained by immersing the crosslinked body in 10 times the amount of pure water at 120°C for 24 hours. [ka] Here, R2 is a polymer chain, and n is an integer of 2 or more.

[0023] The structure of the above formula (3) can be formed by ring-opening polymerization of an epoxy-modified polymer of the following formula (4) with a fatty acid salt. [ka]

[0024] Before ring-opening polymerization, the epoxy monomer (2) and the epoxy-modified polymer (4) are in a highly fluid or soft state, allowing them to be easily placed at a predetermined location, such as a metal surface, to assume a desired shape. Furthermore, contacting the epoxy monomer or epoxy-modified polymer with a fatty acid salt at relatively low temperatures, such as room temperature, does not cause ring-opening polymerization. Therefore, the polymers and crosslinked products of the present disclosure are highly moldable in their raw material state before heating. However, upon heating, a ring-opening polymerization reaction occurs, forming a polymerized structure having the structure (1) or a crosslinked structure having the structure (3), resulting in a highly heat-resistant state in which flow only begins at temperatures above 150°C. Thus, the polymers and crosslinked products of the present disclosure combine moldability with heat resistance. Furthermore, because ring-opening polymerization of epoxy compounds with fatty acid salts does not generate hydroxyl groups or require acidic substances, the resulting polymers and crosslinked products have a near-neutral pH of between pH 4 and pH 9 in the extraction water. Therefore, adhesion to metal surfaces via hydroxyl groups and corrosion of the metal surfaces are unlikely to occur, making the polymer and crosslinked product suitable for peelably coating metal surfaces.

[0025] Here, the polymer preferably does not contain any compound that causes ring-opening polymerization of an epoxy group, except for the fatty acid salt. Furthermore, the crosslinked body preferably does not contain any compound that causes ring-opening polymerization of an epoxy group, except for the fatty acid salt. As described above, the polymer and crosslinked body of the present disclosure can be formed by ring-opening polymerization of an epoxy compound using a fatty acid salt. Therefore, it is not necessary to add compounds other than the fatty acid salt, such as a crosslinking agent for addition polymerization or an initiator for cationic polymerization, for the purpose of ring-opening polymerization of an epoxy group. The absence of these compounds prevents addition polymerization or cationic polymerization of the epoxy compound, thereby suppressing phenomena associated with addition polymerization or cationic polymerization, such as adhesion to metal surfaces and corrosion of metal surfaces. The compounds that cause ring-opening polymerization of an epoxy group also include chemical species derived from these compounds that remain after ring-opening polymerization.

[0026] The electric wire of the present disclosure has a conductor made of metal and an insulating coating containing the polymer or the crosslinked product and covering the outer periphery of the conductor. As described above, the polymer and crosslinked product of the present disclosure are easy to mold and have excellent heat resistance, making it possible to easily form an insulating coating of a desired thickness around the outer periphery of the conductor, and they are less likely to deform or denature even when heated by passing current through the conductor. Furthermore, the polymer and crosslinked product of the present disclosure do not adhere to metal surfaces, making it easy to peel off the insulating coating when connecting a terminal to the end of the electric wire, for example. Furthermore, the polymer and crosslinked product of the present disclosure are less likely to cause metal corrosion, so corrosion of the conductor in the electric wire can be avoided.

[0027] The wire harness of the present disclosure includes the polymer or the crosslinked body. The polymer and crosslinked body of the present disclosure can be used as a constituent material of the wire harness for a variety of applications, such as a curable material for covering exposed conductor portions and a molding material, in addition to the insulating coating of the electric wire described above. Furthermore, by utilizing the ease of molding and excellent heat resistance of the polymer and crosslinked body, they can be easily molded into shapes required for each application, and the effects of heat generated during current flow and heat from the surrounding environment can be minimized.

[0028] In the method for producing a polymer according to the present disclosure, a composition containing an epoxy monomer of the following formula (2) and a fatty acid salt is heated to cause a polymerization reaction, thereby producing the polymer. [ka]

[0029] In the method for producing a crosslinked body of the present disclosure, a composition containing an epoxy-modified polymer of the following formula (4) and a fatty acid salt is heated to cause a crosslinking reaction, thereby producing the crosslinked body. [ka]

[0030] In the methods for producing a polymer and a crosslinked body of the present disclosure, a polymer and a crosslinked body are obtained by heating the epoxy group through ring-opening polymerization by a fatty acid salt. This ring-opening polymerization does not proceed at low temperatures, such as room temperature, so that the composition can be easily positioned in a desired position and shape before heating. This provides high convenience in molding. Meanwhile, the polymer and crosslinked body obtained after heating have high heat resistance. Furthermore, since the ring-opening polymerization of the epoxy group does not require the use of compounds that may cause adhesion to or corrosion of metal surfaces, the methods for producing the polymer and the crosslinked body are suitable for peelably coating the surface of metal materials.

[0031] Here, the initiation temperature of the polymerization reaction is preferably 100°C or higher. Also, the initiation temperature of the crosslinking reaction is preferably 100°C or higher. In this case, the epoxy compound before polymerization or before crosslinking does not undergo polymerization or crosslinking reactions at temperatures below 100°C and remains in a highly fluid or soft state. Therefore, high moldability can be ensured in the state before heating.

[0032] [Details of the embodiments of the present disclosure] The polymer, crosslinked body, electric wire, wire harness, method for producing a polymer, and method for producing a crosslinked body according to embodiments of the present disclosure will be described in detail below. Note that the present disclosure is not limited to these embodiments.

[0033] [1] Polymers and manufacturing methods First, a polymer according to an embodiment of the present disclosure and a method for producing the same will be described. The polymer according to this embodiment includes a structure represented by the following formula (1). [ka] Here, R1 is an organic group, and n is an integer of 2 or more. The polymer according to this embodiment has a flow initiation temperature of 150°C or higher, and the acidity of the extracted water is pH 4 or higher and pH 9 or lower. Here, the extracted water refers to a solution obtained by immersing the object, i.e., the polymer in this case, in 10 times the amount (by mass) of pure water at 120°C for 24 hours (the same applies to the extracted water hereinafter).

[0034] In formula (1), R1 can be any organic group. R1 is preferably a hydrocarbon group or a hydrocarbon group containing a heteroatom such as an oxygen atom at the midpoint or end of the hydrocarbon group. In these cases, the type of hydrocarbon group is not particularly limited, but is preferably an alkyl group, an alkylene group, or an aromatic ring-containing group. The hydrocarbon group may also have a branched structure or a substituent. However, the substituent should preferably not include a substituent that can cause a polymerization reaction of the epoxy compound through a reaction pathway other than the ring-opening polymerization of the epoxy group by a fatty acid salt, as described below, or a substituent that can bond to or react with the fatty acid salt. Examples of substituents that should preferably not be included include an amino group, a thiol group, and an acid anhydride group.

[0035] The structure containing a heteroatom in the middle or at the end of the hydrocarbon group refers to a structure in which carbon atoms are bonded via a heteroatom, such as an ester bond or an ether bond. Preferably, R1 has a structure in which it is bonded to a carbon atom adjacent to an epoxy group via an ether bond, or a glycidyl ester structure in which it is bonded to a carbon atom adjacent to an epoxy group via an ester bond. Furthermore, when a substituent is bonded to a hydrocarbon group, the substituent may be bonded via a structure in which a heteroatom is interposed, such as an ester bond or an ether bond.

[0036] The number of carbon atoms in R1 is not particularly limited, but from the viewpoint of improving the heat resistance of the polymer, it is preferably 3 or more, more preferably 4 or more. On the other hand, from the viewpoint of ensuring high fluidity in the epoxy monomer before polymerization, the number of carbon atoms is preferably 30 or less, more preferably 22 or less.

[0037] In formula (1), n ​​represents the degree of polymerization of the polymer. The value of n is not particularly limited, but from the viewpoint of improving the heat resistance of the polymer, it is preferable that it is 5 or more, and more preferably 30 or more. On the other hand, from the viewpoint of ensuring the flexibility of the polymer, n is preferable that it is 500 or less, and more preferably 200 or less.

[0038] The terminals of the polymer may optionally contain a fatty acid ester structure derived from the fatty acid salt used in the polymerization reaction described below, and an alkoxy metal structure (see (v) in Figure 1). The polymer, excluding the terminals, is preferably composed solely of repeating units of formula (1). However, the polymer may also be a copolymer containing two or more repeating units of formula (1) with different structures in the R1 moiety. The polymer may also be a block copolymer having, in addition to a block composed of repeating units of formula (1), blocks composed of other types of repeating units.

[0039] The polymer has a structure in which a backbone containing an ether bond (...-O-CCOCCO-...) constitutes the main chain, and the R1 moiety is attached as a side chain. This main chain structure is thermally stable, giving the polymer high heat resistance. In fact, as shown in the examples below, the flow initiation temperature of the polymer (the melting point or pour point of the material; if both are present, the lower) is 150°C or higher. The flow initiation temperature of the polymer tends to increase with the number of carbon atoms used as R1 and the degree of polymerization n. By setting the carbon number of R1 to 5 or more and the degree of polymerization n to 10 or more, a flow initiation temperature of 150°C or higher is easily achieved. More preferably, the flow initiation temperature is 200°C or higher, or 230°C or higher. Furthermore, it is desirable that the flow initiation temperature increase by 10°C or more, or even 50°C or more, due to polymerization.

[0040] The polymer of formula (1) can be formed by ring-opening polymerization of an epoxy monomer of formula (2) below with a fatty acid salt. Specifically, a polymerization reaction occurs when a composition containing the epoxy monomer of formula (2) and a fatty acid salt is heated. [ka] Here, the structure of R1 is as explained above for formula (1). The epoxy equivalent of the epoxy monomer is preferably 100 g / eq or more and 500 g / eq or less. The epoxy monomer may be a monoepoxy compound containing only one epoxy group in the molecule, or a polyepoxy compound containing two or more epoxy groups. In the case of a polyepoxy compound, the R1 portion of formula (2) also contains one or more epoxy groups. Furthermore, in the polymer formed from such a polyepoxy compound, the R1 portion of formula (1) contains a polymerization structure resulting from ring-opening polymerization of the epoxy group (in this case, the structure of the R1 portion of formula (1) is such that multiple R1 portions of formula (2) are bonded via the ring-opening polymerization structure of the epoxy group).

[0041] The polymerization mechanism is explained as shown in Figure 1. In other words, as shown in structure (i), a fatty acid salt (here, the terminal is -COO- M + When a metal soap (M, where M is a metal) and an epoxy compound (here, a glycidyl ester) are heated in their coexistence, electrons are transferred between them, resulting in the formation of a new bond between them. Specifically, the carboxylate anion at the end of the fatty acid salt reacts with the epoxy group of the epoxy compound, forming an ester structure and ring-opening the epoxy group. This results in the formation of an alkoxy metal intermediate, as shown in structure (ii). Furthermore, the metal cation contained in this alkoxy metal intermediate extracts an electron from the epoxy group of a new epoxy compound molecule, as shown in structure (iii), ring-opening the epoxy group. This results in the formation of a new alkoxy metal intermediate, as shown in structure (iv), with one new ring-opened epoxy compound inserted. This polymerization reaction proceeds through repeated ring-opening and bonding of the epoxy group by the alkoxy metal intermediate. As a result, many ring-opened epoxy compounds are bonded together, as shown in structure (v), to form a polymer with a main chain containing an ether bond and …-O—CCOCCO-…. This corresponds to the polymer of formula (1).

[0042] The type of fatty acid salt used in the polymerization reaction is not particularly limited, but it is preferable to use a metal salt of a long-chain fatty acid, known as a metal soap. Typically, a mixture of a fatty acid salt and an epoxy compound is stable at room temperature. Furthermore, the initiation temperature of the polymerization reaction is preferably 100°C or higher, or 150°C or higher. Therefore, if the temperature is less than 100°C or less than 150°C, the mixture of the fatty acid salt and the epoxy compound can be stably maintained without reaction. On the other hand, by heating the mixture to a temperature equal to or higher than the initiation temperature of the polymerization reaction, such as 100°C or higher, a polymer having the structure of formula (1) can be obtained. Furthermore, it is preferable for the fatty acid salt to have a melting point of 300°C or lower, or even 250°C or lower. Melting the fatty acid salt to a liquid state can achieve a high reaction rate with the epoxy compound, but heating above 300°C can cause decomposition of the epoxy compound, so it is preferable to melt the fatty acid salt and react it at 300°C or lower. The initiation temperature of the polymerization reaction can be controlled by the specific composition of the fatty acid salt and the epoxy compound. For example, the higher the compatibility between the fatty acid salt and the epoxy compound, the lower the temperature at which the fatty acid salt disperses and dissolves in the epoxy compound, thereby lowering the reaction initiation temperature. Specifically, since epoxy compounds typically lack polar groups such as hydroxyl groups, carboxyl groups, and amino groups, when controlling the reaction initiation temperature low, a fatty acid salt with a long chain (e.g., 9 or more carbon atoms) is preferred, and the metal that forms the salt is preferably one that can form ions that belong to soft acids according to the HSAB rule (e.g., transition metals including zinc, copper, etc.). Conversely, when controlling the reaction initiation temperature high, it is preferable to use a fatty acid salt with a short chain (e.g., 8 or less carbon atoms) that contains a metal that can form ions that belong to hard acids (e.g., typical metals including lithium, magnesium, etc.).

[0043] Preferably, the carbon number of the fatty acid salt is 4 or more, and even more preferably 6 or more. This is because the fatty acid salt will have strong organic properties, lower its melting point, and improve its compatibility with epoxy compounds. On the other hand, from the viewpoint of easy availability and maintaining a high metal content in the molecule, the carbon number of the fatty acid salt is preferably 30 or less, and even more preferably 24 or less. Suitable examples of fatty acid salts include behenate, stearate, palmitate, myristate, laurate, caprate, caprylate, erucate, oleate, and palmitoleate. The type of metal constituting the metal soap is not particularly limited and may be monovalent or divalent or higher. Regardless of the valence, the alkoxy metal intermediates shown in (ii) and (iii) of Figure 1 can be stably formed. Suitable examples of metals include alkali metals such as Li, alkaline earth metals such as Mg and Ca, and Zn.

[0044] In a composition containing epoxy monomer and fatty acid salt as polymerization raw materials, the amount of fatty acid salt added is preferably 0.1% by mass or more, and even 1% by mass or more, relative to the epoxy monomer. On the other hand, the amount of fatty acid salt added is preferably limited to 50% by mass or less, and even more preferably 30% by mass or less. As shown in structure (iii) in Figure 1, during the polymerization of epoxy monomer, once an alkoxy metal intermediate is generated, electrons are extracted from the epoxy group, catalytically forming a new epoxy ring-opened product. Therefore, it is not necessary to add an equimolar amount of fatty acid salt to the epoxy monomer or an amount close to that amount to form a polymer. The reaction can proceed sufficiently with an amount of fatty acid salt added up to the upper limit mentioned above. However, if the amount of fatty acid salt is too small, the polymerization reaction will proceed slowly, and the alkoxy metal intermediate may be deactivated before the polymerization has progressed sufficiently. Therefore, it is preferable to add the amount of fatty acid salt above the lower limit mentioned above. Adding a large amount of fatty acid salt may deteriorate the physical properties of the polymer, so it is preferable to add an amount that is just enough to be used in the polymerization reaction.

[0045] As described above, the mixture of fatty acid salt and epoxy compound is stable from room temperature to a certain high temperature (e.g., about 100°C) without undergoing polymerization. Therefore, during storage or preparation of the polymerization raw materials, the mixture is maintained within a temperature range that maintains its stability. When starting the polymerization reaction, the mixture is heated to a temperature at which the ring-opening polymerization reaction illustrated in FIG. 1 occurs, for example, 100°C or higher, or even 150°C or higher. Furthermore, it is preferable that the fatty acid salt be melted at that temperature. During the polymerization reaction, the reaction rate can be controlled by adjusting the heating temperature. The higher the temperature, the faster the polymerization reaction rate. However, since heating to an excessively high temperature may cause decomposition of the epoxy compound, it is preferable to keep the reaction temperature below 300°C, preferably below 250°C. The polymerization reaction may also be carried out by heating the mixture in an organic solvent.

[0046] As described above, the polymer according to this embodiment can be formed by heating a composition containing a fatty acid salt and an epoxy monomer. Before polymerization, the composition is in a highly fluid or soft state. This pre-polymerization composition can be placed in a predetermined position, such as the outer periphery of an electric wire conductor (described later), by extrusion molding or liquid application, to form a desired shape, and then polymerized. This results in a polymer with excellent moldability. Furthermore, since the polymerization reaction does not proceed at low temperatures, such as room temperature, unintended polymerization reactions do not occur during the preparation or molding of the composition, which also contributes to excellent molding convenience. Meanwhile, after polymerization, the polymer according to this embodiment has stable polymer chains containing ether bonds and is in a highly heat-resistant state with a flow initiation temperature of 150°C or higher. Therefore, the polymer can be suitably used in applications that are subject to heat, such as the insulating coating of electric wires. Thus, the polymer according to this embodiment combines ease of molding with excellent heat resistance.

[0047] Furthermore, as shown in Figure 1, the polymer according to this embodiment proceeds via the formation of an alkoxy metal intermediate by electron abstraction from the epoxy group by the fatty acid salt, and the reaction does not require the use of an acid or base. Furthermore, during the reaction process, no by-products, including protons and hydroxyl groups, are released from either the fatty acid salt or the epoxy monomer. Therefore, the resulting polymer is neutral or close to neutral, and the extracted water exhibits an acidity of pH 4 or higher and 9 or lower. More preferably, the pH is 6 or higher and 8 or lower.

[0048] As described above, the polymer does not contain acids or bases derived from the polymerization raw materials or by-products during polymerization, making the polymer of this embodiment suitable for applications involving peelable coating of metal surfaces. In other words, if the polymer contains hydroxyl groups, the polymer will adhere to the metal surface through electrostatic interactions with the metal surface, particularly hydrogen bonding with hydroxyl groups generated on the metal surface by cleavage of water molecules. However, the polymer of this embodiment is substantially free of hydroxyl groups, and therefore does not exhibit adhesive properties to the metal surface and remains peelable. This differs from the case where epoxy monomers are polymerized by addition polymerization using curing agents such as amines or hydroxyl-containing compounds, which exhibit adhesive properties to metal surfaces sufficient for use as adhesives. Note that when epoxy polymers are formed by addition polymerization using these curing agents, adjacent epoxy ring-opening units are not directly bonded as in formula (1), but rather a crosslinked structure is formed between them by the curing agent. Furthermore, the absence of acid in the polymer of this embodiment prevents corrosion of the coated metal surface. This differs from the case where epoxy monomers are polymerized by cationic polymerization, which requires the use of an acidic initiator such as a Lewis acid, and the residual acid component can cause corrosion of metal materials. The absence of by-products during polymerization not only means that the polymer is maintained in a neutral or nearly neutral state, but also means that the shape of the material is less likely to change before and after polymerization, which also improves convenience during molding. The polymer according to this embodiment preferably does not contain an acidic or basic group in the R1 structure of formula (1) or, if a repeating unit other than formula (1) is included, in the repeating unit.

[0049] The polymer according to this embodiment may be used alone for applications such as coating metal surfaces, or may contain other components by adding them to a composition before polymerization. Examples of such components that can be added include polymer components other than the epoxy polymer of formula (1). Examples of polymer components other than the epoxy polymer include polyolefins, polyesters, and polyurethanes. Examples of additives other than the polymer components include flame retardants, copper inhibitors, antioxidants, and colorants.

[0050] However, it is preferable not to add components having acidic or basic groups to the polymer of this embodiment. The acidity of the extraction water for the entire polymer material, including the added components, should be between pH 4 and 9. Furthermore, the polymer of this embodiment and the composition used as its raw material preferably do not contain any compound that causes ring-opening polymerization of epoxy groups, except for the fatty acid salt. As described with reference to FIG. 1 , the polymer of this embodiment can sufficiently proceed with the polymerization reaction using only the fatty acid salt, and there is no need to use other compounds that cause ring-opening polymerization of epoxy groups. Furthermore, the use of such compounds may generate acids or bases in the polymer material, which may impair the suitability of the polymer of this embodiment for applications involving peelable coating of metal surfaces.

[0051] Examples of compounds that cause ring-opening polymerization of epoxy groups and that should not be added include the following: Curing agents that cause addition polymerization of epoxy compounds: amine compounds, thiol compounds, hydroxyl group-containing compounds, acid anhydrides, isocyanates, isothiocyanates, etc. Initiators that cause cationic polymerization of epoxy compounds: iodonium compounds, sulfonium compounds, fluorophosphate compounds, fluoroborate compounds, fluorophenylborate compounds, fluoroantimonate compounds, fluoroarsenate compounds, fluoromethanesulfonic acid compounds, p-toluenesulfonic acid compounds, etc. Furthermore, it is also preferable not to add cationic polymerization initiators or radical polymerization initiators that act by a mechanism different from those of the curing agent or initiator. The above-mentioned compounds and additives also include chemical species that are derived from these compounds and additives and remain in the material after reactions such as ring-opening polymerization of epoxy groups, and it is preferable that these chemical species do not exist in the polymer.

[0052] [2] Crosslinked body and manufacturing method Next, a crosslinked body according to an embodiment of the present disclosure and a method for producing the same will be described. The crosslinked body according to this embodiment includes a structure represented by the following formula (3). [ka] Here, R2 is a polymer chain, and n is an integer of 2 or more. The crosslinked body according to this embodiment has a flow-start temperature of 150° C. or higher, and the acidity of the extraction water is pH 4 or higher and 9 or lower.

[0053] In formula (3), R2 can be any polymer chain. Here, polymer chains include those with a relatively low degree of polymerization, such as oligomer chains. R2 is preferably a polyolefin chain or a polyolefin chain containing a heteroatom in the form of an ester bond, ether bond, or the like, at the middle or end of the polyolefin chain. Such polyolefin chains may have a branched structure or a substituent. However, the substituents should preferably not include functional groups that can cause a reaction of the epoxy compound through a reaction pathway other than the ring-opening polymerization of the epoxy group by the fatty acid salt, or substituents that can bond to or react with the fatty acid salt. Furthermore, it is preferable that the substituents should preferably not include acidic or basic substituents.

[0054] The structure of formula (3) corresponds to a state in which multiple polymer chains R2 are crosslinked via a -CCO- structure. n indicates the number of crosslinked polymer chains and is not particularly limited, but for example, n may be 3 or more. Also, n may be 100 or less. Furthermore, it is preferable that multiple crosslinking sites exist in one polymer chain. The crosslinked polymer chain R2 may contain only one type, or two or more different types may be mixed and crosslinked.

[0055] The crosslinked body has a structure in which polymer chains are crosslinked by crosslinking moieties having a -CCO- structure. These crosslinking moieties are thermally stable, giving the crosslinked body high heat resistance. In fact, as shown in the examples below, the flow initiation temperature of the crosslinked body is as high as 150°C or higher. More preferably, the flow initiation temperature is 200°C or higher, or even 270°C or higher. The flow initiation temperature of the crosslinked body tends to increase as a higher flow initiation temperature is adopted as R2. For example, the flow initiation temperature of the epoxy-modified polymer before crosslinking, as shown in the following formula (4), may be 50°C or higher, or even 80°C or higher. Furthermore, the formation of the crosslinked structure may increase the flow initiation temperature by 10°C or more, or even 50°C or more.

[0056] The polymer of formula (3) can be formed by ring-opening polymerization of an epoxy-modified polymer of formula (4) below with a fatty acid salt. Specifically, a crosslinking reaction occurs when a composition containing the epoxy-modified polymer of formula (4) and the fatty acid salt is heated. [ka] Here, the structure of R2 is as explained above for formula (3). The epoxy group may be contained in the main chain of the polymer chain R2, but from the viewpoint of high reactivity, it is preferable that it is contained in the side chain in the form of glycidyl ether. It is also preferable that one polymer chain has multiple epoxy groups. The epoxy equivalent of the epoxy-modified polymer is preferably 100 g / eq or more and 5000 g / eq or less.

[0057] The crosslinking reaction proceeds via a mechanism involving the generation of an alkoxy metal intermediate, similar to that described above with reference to FIG. 1 for the polymer according to the embodiment of the present disclosure. Therefore, the epoxy-modified polymer before crosslinking and the fatty acid salt are mixed, placed in a predetermined position so as to assume the desired shape, and then heated to allow the crosslinking reaction, which involves ring-opening of the epoxy groups, to proceed. The initiation temperature of the crosslinking reaction is preferably 100°C or higher, or 150°C or higher. The initiation temperature of the crosslinking reaction can be controlled by the specific configurations of the fatty acid salt and the epoxy-modified polymer. For example, the higher the compatibility between the fatty acid salt and the epoxy-modified polymer, the lower the dispersion and dissolution of the fatty acid salt in the epoxy-modified polymer, thereby lowering the reaction initiation temperature. Specifically, the same fatty acid salt structures as those listed above for the polymerization reaction can be used to lower or raise the reaction initiation temperature.

[0058] When the flow initiation temperature of the epoxy-modified polymer is lower than the temperature at which the crosslinking reaction occurs, such as below 100°C, an uncrosslinked mixed material can be obtained by kneading the epoxy-modified polymer and fatty acid salt at a temperature lower than the temperature at which the crosslinking reaction occurs. On the other hand, when the flow initiation temperature of the epoxy-modified polymer is higher than the temperature at which the crosslinking reaction occurs, such as 100°C or higher, an uncrosslinked mixed material can be obtained by dissolving the epoxy-modified polymer and fatty acid salt in an organic solvent, mixing them at a temperature below the temperature at which the crosslinking reaction occurs, and then drying. The mixed material obtained by these methods can be molded into a desired shape by extrusion molding or the like, and then heated to a temperature above the reaction initiation temperature of the crosslinking reaction, such as 100°C or higher, to obtain a crosslinked product of formula (3). In this case, if the temperature during molding of the mixed material by extrusion molding or the like is set high enough to achieve a high crosslinking rate (e.g., 150°C or higher), crosslinking can be achieved simultaneously with molding.

[0059] The polymer of formula (1) and the crosslinked product of formula (3), and the epoxy monomer of formula (2) and the epoxy-modified polymer of formula (4) differ only in that the R1 moiety is an organic group that is not a polymer chain, while the R2 moiety is a polymer chain. Therefore, in the case of a crosslinking reaction, the mechanism of the reaction that occurs with a fatty acid salt is the same as that explained for a polymerization reaction with reference to Figure 1, and the above explanation for the polymer also applies to the crosslinked product. Therefore, the above explanations for the polymer, such as the structure and amount of fatty acid salt added, reaction conditions including reaction temperature, other components that may be added, other components that should not be added, and applications, also apply to the crosslinked product by appropriately replacing R1 with R2 and polymerization with crosslinking, etc.

[0060] Whether to use a polymer or a crosslinked product can be selected depending on the application and the location of application. For example, since the epoxy-modified polymer, which is the raw material for the crosslinked product, has a higher viscosity than the epoxy monomer, which is the raw material for the polymer, the polymer is more suitable for application in liquid form and molding, while the crosslinked product is more suitable for molding by extrusion molding.

[0061] [3] Electrical wires and wiring harnesses The polymers and crosslinked bodies according to the embodiments of the present disclosure described above can be suitably used in applications requiring heat resistance and peelable coating of metal materials. As examples of such applications, electric wires and wire harnesses will be briefly described. FIG. 1 shows the structure of an example of an electric wire. The electric wire 1 has a conductor 2 made of a metal material and an insulating coating 3 that coats the outer periphery of the conductor 2. The insulating coating 3 contains the polymer or crosslinked body according to the embodiments of the present disclosure described above.

[0062] The conductor 2 of the electric wire 1 is not particularly limited in terms of its diameter or material, and can be appropriately selected depending on the application of the electric wire 1. Metallic materials such as copper, copper alloys, aluminum, and aluminum alloys can be suitably used as materials for the conductor 2. The conductor 2 may be made of a single wire, but is preferably made of a stranded wire in which a plurality of wires are twisted together, from the viewpoint of ensuring flexibility, etc.

[0063] The polymer and crosslinked body according to the embodiment of the present disclosure are easy to mold, allowing an insulating coating 3 of a predetermined thickness to be easily formed around the periphery of the conductor 2. Furthermore, because the polymer and crosslinked body have high heat resistance, the insulating coating 3 is less likely to deform or deteriorate even if it is heated by passing current through the conductor 2. Furthermore, because the polymer and crosslinked body are made of near-neutral materials, the conductor 2 is less likely to corrode due to acid, and the insulating coating can be easily stripped from the terminal portion of the electric wire 1, etc.

[0064] A wire harness according to an embodiment of the present disclosure includes a polymer or crosslinked body according to an embodiment of the present disclosure. The application locations of the polymer or crosslinked body are not particularly limited. For example, an example of a wire harness in which an electric wire is constituted by the electric wire 1 described above having the polymer or crosslinked body according to an embodiment of the present disclosure as an insulating coating 3 can be exemplified. In addition, in a wire harness, the polymer or crosslinked body can be suitably used as a curable material or molding material that coats the surface of metal materials such as electric wire conductors and terminal materials at connections between terminals and conductors, or at locations where exposed conductors or terminal materials need to be waterproofed. In particular, a polymer can be suitably used as a curable material, and a crosslinked body can be suitably used as a molding material. By utilizing the properties of the polymer and crosslinked body in each location, a coating can be constructed that has excellent properties such as ease of molding, heat resistance against heating due to current flow, corrosion prevention of the coated metal material, and ease of peeling. [Example]

[0065] Examples are shown below. The present invention is not limited to these examples. Unless otherwise specified, sample preparation and evaluation were carried out at room temperature in the atmosphere.

[0066] <Sample preparation> A mixed solution of materials was prepared for samples A1 to A9 and B1 to B8. Specifically, the components listed in Table 1 below were prepared in the mixing ratios shown in Table 1, and stirred with xylene in an amount 9 times the amount of the epoxy compound (epoxy monomer or epoxy-modified resin) at 50°C for 1.5 hours. The mixed solution was then returned to room temperature.

[0067] Next, solid samples were prepared using the above material mixture solutions. Each material mixture solution, in which a fatty acid salt or an amine curing agent was added to an epoxy compound (if gelled, the gel was used as well), was poured into a 30 mm x 30 mm x 30 mm Teflon frame (Teflon is a registered trademark; the same applies below), air-dried, and then vacuum-dried to remove the xylene. The sample was then left in an oven at 180°C for 10 minutes to heat it for reaction (polymerization or crosslinking reaction), and then returned to room temperature. If the sample was in a solid state, it was removed from the Teflon frame. On the other hand, for samples in which a cationic curing agent was added to an epoxy compound, the material mixture solution was irradiated with a UV lamp (manufactured by SEN Tokushu Kogen Co., Ltd.; 100 mW / cm 2 ) for 5 minutes to allow the reaction (polymerization reaction or crosslinking reaction) to occur.

[0068] The components used in preparing the samples are as follows: (1) Epoxy monomer CH-ep: 3,4-epoxycyclohexylmethyl 3',4'-epoxycyclohexanecarboxylate (molecular weight 252.3, liquid at room temperature, epoxy equivalent 126 g / eq; Fujifilm Wako Pure Chemical Industries, Ltd.) OD-ep: 1,2-epoxyoctadecane (molecular weight 268.5, flow temperature 27°C, epoxy equivalent 269g / eq; manufactured by Tokyo Chemical Industry Co., Ltd.) (2) Epoxy-modified resin BF-E: Bondfast BF-E (ethylene-glycidyl methacrylate copolymer; average molecular weight 2.2 × 10 5 , flow starting temperature 110°C, epoxy equivalent 1185g / eq; manufactured by Sumitomo Chemical Co., Ltd.) BF-7M: Bondfast BF-7M (ethylene-glycidyl methacrylate copolymer; average molecular weight 1.9 × 10 5 , flow starting temperature 55°C, epoxy equivalent 2370g / eq; manufactured by Sumitomo Chemical Co., Ltd. (3) Fatty acid salts (metal soaps) st-Li: Lithium stearate (molecular weight 290.4; melting point 220°C; Fujifilm Wako Pure Chemical Industries, Ltd.) st-Mg: Magnesium stearate (molecular weight 591.3; melting point 200°C; Fujifilm Wako Pure Chemical Industries, Ltd.) st-Ca: Calcium stearate (molecular weight 607.0; melting point 180°C; Fujifilm Wako Pure Chemical Industries, Ltd.) st-Zn: Zinc stearate (molecular weight 632.3; melting point 128°C; Fujifilm Wako Pure Chemical Industries, Ltd.) (4) Amine hardener DTA: Diethylenetriamine (molecular weight 103.2, liquid at room temperature, amine active hydrogen equivalent 21 g / eq; manufactured by Tokyo Chemical Industry Co., Ltd.) (5) Cationic curing agent (initiator, photoacid generator) WPI-116: Bis[n-alkyl(C10-13)phenyl]iodonium hexafluoroantimonate (50% propylene carbonate solution; molecular weight 853.5 (n=12); Fujifilm Wako Pure Chemical Industries, Ltd.)

[0069] <Evaluation method> (1) Flow start temperature In the above sample preparation process, the sample was left in an oven at 180°C for 10 minutes, after which the state of the contents in the Teflon frame was checked with a spatula, and any liquid content was deemed to have undergone no polymerization or crosslinking (denoted as "L" in Table 1). On the other hand, any solid content was removed from the Teflon frame and cut into test pieces measuring 10 mm long x 10 mm wide x 2 mm thick, and the flow initiation temperature was measured.

[0070] To measure the flow initiation temperature, a test specimen was placed on a temperature-variable hot plate, and a 2 mm diameter cylindrical indenter with a dial gauge attached to the top was pressed against the center of the specimen with a force of 1 N. The temperature of the hot plate was then increased at a rate of 5°C / min, and the distance the indenter penetrated into the sample was recorded. The temperature when the indenter penetrated 2.0 mm (when it penetrated the specimen) was recorded as the flow initiation temperature. Samples with a flow initiation temperature 10°C or higher than that of epoxy compounds without fatty acid salts, amine curing agents, or cationic curing agents can be considered to be undergoing polymerization or crosslinking reactions.

[0071] (2) Acidity of the extraction water 1 g of each solidified test piece was weighed out, cut into small pieces, and placed in a pressure bottle. 10 g of pure water was added and the bottle was sealed. The pressure bottle was heated in an oven at 120 °C for 24 hours with occasional shaking to perform extraction. The pressure bottle was then returned to room temperature, and only the aqueous phase was sampled with a pipette. The acidity of the extracted water was measured using a pH meter.

[0072] (3) Metal peelability For the samples that solidified after heating in an oven at 180°C in the above sample preparation process, the pre-cured material mixture solution was poured into a Teflon frame measuring 30 mm in length, 5 mm in width, and 5 mm in depth placed on a copper plate. To ensure a grip for peeling after polymerization or crosslinking, the 5 mm lengthwise edge of the copper plate was protected with Teflon tape to prevent contact between the copper plate and the material mixture solution. After that, as in the above sample preparation process, the xylene was removed by air drying and vacuum drying. The sample was then left in an oven at 180°C for 10 minutes to allow for a thermal reaction, and then returned to room temperature.

[0073] The Teflon frame was then removed, the gripping portion was grasped, and the solid layer was pulled perpendicular to the copper plate using a tensile tester to check the peelability. Materials that peeled easily were rated as having good peelability (A). On the other hand, materials that broke before peeling or materials with fragments remaining on the copper plate after peeling were rated as having poor metal peelability (B).

[0074] (4) Fluidity after heating at 90℃ For samples that solidified after heating at 180°C in the sample preparation process, the uncured material mixture solution was poured into a Teflon frame measuring 30 mm long x 30 mm wide x 30 mm deep, air-dried, and then vacuum-dried to remove the xylene. The sample was then placed in a 90°C oven for 10 minutes, then returned to room temperature, and the state of the contents in the Teflon frame was checked with a spatula. Samples that remained liquid were considered to have undergone no polymerization at 90°C (denoted "L" in Table 1). Samples that were confirmed to be solid were removed from the Teflon frame and cut into test pieces measuring 10 mm long x 10 mm wide x 2 mm thick. The flow onset temperature was measured using the same method as in (1) Flow Onset Temperature Evaluation above. This confirmed whether polymerization or crosslinking reactions occurred at 90°C.

[0075] (6) Confirmation of the product Infrared absorption spectroscopy (FT-IR) was used to investigate the compounds produced in the solid material when a material mixture containing an epoxy compound and a fatty acid salt was heated to form a solid. Sample A5, which used OD-ep as the epoxy compound and st-Mg as the fatty acid salt, was analyzed as a representative example. FT-IR measurements were performed on OD-ep alone (i) before heating and (ii) after heating at 150°C for 5 minutes. FT-IR measurements were also performed on a mixed solution containing 100 parts by weight of OD-ep and 5 parts by weight of st-Mg (i.e., sample A5) (iii) before heating and (iv) after heating at 150°C for 5 minutes.

[0076] <Evaluation results> Table 1 below summarizes the results of various evaluations for Samples A1 to A9 and Samples B1 to B8, along with the blending amount of each component (unit: parts by mass).

[0077] [Table 1]

[0078] According to Table 1, Samples A1 to A5, which use a mixed solution of epoxy monomer and fatty acid salt, and Samples A6 to A9, which use a mixed solution of epoxy-modified resin and fatty acid salt, all have flow initiation temperatures exceeding 200°C, significantly higher than the flow initiation temperature of the epoxy compound alone. This suggests that the epoxy compound in each mixed solution undergoes polymerization or crosslinking reactions and solidifies after heating at 180°C. While the flow initiation temperatures of the epoxy compounds used differ significantly between Samples A1 to A4 and A5, and between Samples A6 and A7, the flow initiation temperatures when reacted with fatty acid salt are almost the same. This indicates that high flow initiation temperatures can be achieved through polymerization and crosslinking reactions, even when the flow initiation temperatures of the epoxy compounds used as raw materials differ. There is also little difference in flow initiation temperatures due to the fatty acid salt. Samples A7 to A9 use different amounts of fatty acid salt, but all achieve flow initiation temperatures above 270°C, indicating that the crosslinking reaction proceeds sufficiently regardless of the amount of fatty acid salt added.

[0079] Furthermore, for all of Samples A1 to A5 and Samples A6 to A9, the acidity of the extracted water was pH 6.0 to 8.0, confirming the absence of acidic or basic products. Metal peelability was also good, confirming the absence of adhesion of the polymer or crosslinked body to the metal surface via hydroxyl groups or the like. Furthermore, for all of these samples, the flow initiation temperature after heating to 90°C remained almost unchanged from the flow initiation temperature of the raw material epoxy compound. This confirms that the polymerization and crosslinking reactions observed when heated to 180°C did not occur at 90°C, and that the material mixture solution remained stable at 90°C without any reaction.

[0080] Sample B1, which does not contain fatty acid salts or various hardeners, remained in a liquid state similar to the original epoxy monomer even after heating at 180°C, indicating that no polymerization reaction occurred. Sample B2, which also does not contain fatty acid salts or various hardeners, did not change its flow initiation temperature from the original epoxy-modified resin even after heating at 180°C, indicating that no crosslinking reaction occurred. The poor metal peelability of Sample B2 is thought to be due to the generation of hydroxyl groups at the metal interface by the epoxy groups.

[0081] Samples B3-B5 did not contain fatty acid salts but instead contained amine curing agents. Samples B3 and B5, which contain epoxy compounds containing multiple epoxy groups within their molecules, exhibited elevated flow initiation temperatures after heating at 180°C, suggesting that the polymerization and crosslinking reactions of the epoxy compounds were progressing. However, these reactions were addition polymerizations mediated by the amine curing agent, which correspondingly reduced metal peelability. This is likely due to the generation of hydrogen-bonding hydroxyl groups in the polymer and crosslinked product during the addition polymerization. The flow initiation temperature of sample B3 was lower than that of samples A1-A4, likely due to the incorporation of amine curing agent molecules into the polymer chains of the epoxy monomer polymer, preventing the polymer chains from aligning uniformly. The acidity of the extracted water was high, exceeding pH 10. This is due to the basicity of the amino groups contained in the amine curing agent, polymer, or crosslinked product. The flow initiation temperature after heating at 90°C was nearly the same as when heated at 180°C, indicating that the polymerization and crosslinking reactions were nearly complete at 90°C.

[0082] Sample B4 uses a monoepoxy compound, which contains only one epoxy group per epoxy monomer molecule, and therefore cannot be polymerized with a monoamine curing agent. Correspondingly, there is almost no increase in the flow initiation temperature. Metal peelability could not be evaluated due to the sample's brittleness and low melting point.

[0083] Samples B6 to B8 did not contain any fatty acid salts, but instead contained a cationic curing agent. In all samples, the flow initiation temperature rose to over 200°C as cationic polymerization progressed. However, the extracted water had a low pH of less than 3. This is thought to be due to acidification caused by the remaining cationic curing agent. The flow initiation temperature after heating to 90°C was nearly the same as when heated to 180°C, indicating that the polymerization and crosslinking reactions were nearly complete at 90°C.

[0084] Comparing Samples A1 to A9 with Samples B1 to B8, it is clear that adding a fatty acid salt to an epoxy compound makes it possible to produce a polymer or crosslinked product with excellent metal peelability without generating hydroxyl groups or acids after heating at 180° C. Furthermore, this reaction does not occur at relatively low temperatures below 90° C., demonstrating excellent reaction controllability.

[0085] Finally, Figure 3 shows the results of FT-IR measurements on a material corresponding to sample A5. (i) shows the state of epoxy monomer alone before heating, (ii) shows the state after heating at 150°C, (iii) shows the state of the mixture with added fatty acid salt before heating, and (iv) shows the state after heating at 150°C. First, for (i) and (ii) to which no fatty acid salt was added, there was no noticeable change in the spectrum before and after heating, and the peak at 910 cm -1 and 840 cm -1 The absorption peaks of the epoxy groups (peaks B1 and B2) maintain almost the same intensity. This means that simply heating the epoxy monomer without adding a fatty acid salt does not cause reactions such as polymerization, and no major changes occur in the chemical state of the epoxy monomer.

[0086] In contrast, when comparing the spectra of (iii) and (iv) to which fatty acid salts were added, the intensity of the epoxy group peaks (peaks B1 and B2) in (iv) after heating was significantly reduced compared to (iii) before heating. -1A new broad peak appears near this point (peak A). This new peak is a peak characteristic of ether bonds (C-O-C antisymmetric stretching vibration). From these results, it can be seen that adding a fatty acid salt to an epoxy compound and heating it causes a reaction involving the ring-opening of the epoxy group and the formation of an ether bond. In other words, it can be said that a polymer with the structure shown in formula (1) is formed through the polymerization reaction. [Explanation of symbols]

[0087] 1 electric wire 2 conductors 3. Insulation coating

Claims

1. It comprises the structure of the following formula (1): consisting solely of repeating units of formula (1) except for terminal portions, The flow starting temperature is 150°C or higher, The acidity of the extract obtained by immersing the material in 10 times the amount of pure water at 120°C for 24 hours is pH 4 or more and 9 or less, A polymer that does not contain a compound that causes ring-opening polymerization of an epoxy group, or a chemical species that remains derived from the compound after ring-opening polymerization of an epoxy group, except for a fatty acid salt that is an alkaline earth metal salt or a transition metal salt of a fatty acid. 【Chemistry 1】 However, R １ is an organic group, and n is an integer of 2 or more. The structure of the formula (1) is obtained by ring-opening polymerization of an epoxy monomer of the following formula (2) with the fatty acid salt. 【Chemistry 2】

2. The polymer according to claim 1 , wherein the polymer does not contain any acidic or basic groups.

3. The polymer according to claim 1 or 2, which does not contain a component having an acidic group or a component having a basic group.

4. 3. The polymer according to claim 1, which is free of amine compounds, hydroxyl group-containing compounds, isocyanates, and chemical species derived from these compounds remaining in the material.

5. It comprises the structure of the following formula (3): consisting solely of repeating units of formula (3) except for terminal portions, The flow starting temperature is 150°C or higher, The acidity of the extract obtained by immersing the material in 10 times the amount of pure water at 120°C for 24 hours is pH 4 or more and 9 or less, A crosslinked body that does not contain a compound that causes ring-opening polymerization of an epoxy group, or a chemical species that remains derived from the compound after ring-opening polymerization of an epoxy group, except for a fatty acid salt that is an alkaline earth metal salt or a transition metal salt of a fatty acid. 【Transformation 3】 However, R ２ is a polymer chain, and n is an integer of 2 or more. The structure of the formula (3) is obtained by ring-opening polymerization of an epoxy-modified polymer of the following formula (4) with the fatty acid salt. 【Chemistry 4】

6. The crosslinked product according to claim 5 , which does not contain an acidic group or a basic group.

7. The crosslinked body according to claim 5 or 6, wherein a component having an acidic group and a component having a basic group are not added.

8. 7. The crosslinked body according to claim 5, which is free of amine compounds, hydroxyl group-containing compounds, isocyanates, and chemical species derived from these compounds remaining in the material.

9. a conductor made of a metal; an insulating coating that covers an outer periphery of the conductor, the insulating coating comprising the polymer according to claim 1 or the crosslinked body according to claim 5; An electric wire having:

10. A wire harness comprising the polymer according to claim 1 or the crosslinked product according to claim 5.

11. A method for producing a polymer, comprising heating a composition containing the epoxy monomer of formula (2) and the fatty acid salt, and not containing any compound that causes ring-opening polymerization of an epoxy group except for the fatty acid salt, to cause a polymerization reaction, thereby producing the polymer according to claim 1 or 2.

12. The method for producing a polymer according to claim 11, wherein the initiation temperature of the polymerization reaction is 100°C or higher.

13. The method for producing a polymer according to claim 11 , wherein the composition does not contain an amine compound, a hydroxyl group-containing compound, or an isocyanate.

14. A method for producing a crosslinked body according to claim 5 or 6, comprising heating a composition containing the epoxy-modified polymer of formula (4) and the fatty acid salt, and not containing any compound that causes ring-opening polymerization of an epoxy group except for the fatty acid salt, to cause a crosslinking reaction, thereby producing the crosslinked body according to claim 5 or 6.

15. The method for producing a crosslinked body according to claim 14, wherein the initiation temperature of the crosslinking reaction is 100°C or higher.

16. The method for producing a crosslinked body according to claim 14, wherein the composition does not contain an amine compound, a hydroxyl group-containing compound, or an isocyanate.

Images