Insulating resin

Abstract

The present invention provides an insulating resin that exhibits a uniform dielectric breakdown field improvement effect throughout the entire film and suppresses film degradation due to heating. [Solution] The insulating resin comprises (A) a thermoplastic resin which is at least one selected from polycarbonate resin, polyester resin, and polyarylate resin, and (B) a metal diketone complex which is crosslinked by ether bonds and contains one or more β-diketones as ligands.

Description

Technical Field

[0001] The present disclosure relates to an insulating resin. More specifically, it relates to an insulating resin containing a metal diketone complex crosslinked by an ether bond.

Background Art

[0002] Film capacitors are mounted in various electronic devices, and resin films are used as insulating materials and dielectric materials. In recent years, due to the miniaturization and high functionality of electronic devices, the usage environment of electronic components has become hotter. These electronic components are required to have heat resistance that can provide stable electrical characteristics for a long time even in a high-temperature environment. As a means to reduce the size of film capacitors, thinning of the dielectric film, reduction in the number of layers and winding turns of the dielectric film can be mentioned. However, in order to thin the dielectric film, it is necessary to improve the breakdown voltage of the dielectric film. As a method for improving the breakdown voltage, for example, in Patent Document 1, it has been proposed to use an insulating resin containing a metal diketone complex as an additive in a thermoplastic resin in order to increase the breakdown voltage of the dielectric film.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Disclosure of the Invention

Problems to be Solved by the Invention

[0004] In the prior art of Patent Document 1 above, the insulating resin containing a conventional metal diketone complex as an additive has a problem that although the breakdown electric field is improved, its effect cannot be uniformly exerted on the entire film. In addition, there is a problem that the molecular chains of the polymer, which is the main component of the dielectric film, are decomposed by heating and the deterioration of the dielectric film progresses.

[0005] Therefore, there is a need for an insulating resin that uniformly improves the dielectric breakdown field throughout the entire film and can suppress the degradation of the dielectric film even when heated. [Means for solving the problem]

[0006] The thermoplastic resin of this disclosure comprises (A) a thermoplastic resin and (B) a metal diketone complex crosslinked by an ether bond. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide an insulating resin that can uniformly exhibit a dielectric breakdown field improvement effect throughout the entire film and suppresses film degradation even when heated. [Brief explanation of the drawing]

[0008] [Figure 1] This is a conceptual diagram showing the position of the central metal of a metal diketone complex in a thermoplastic resin film when a conventional metal diketone complex is replaced with a metal diketone complex crosslinked by an ether bond. [Figure 2] This is a chemical formula showing the process by which polyarylate resin is decomposed by metal diketone complexes. [Figure 3] This graph shows the change in weight-average molecular weight of a dielectric film with respect to heating time. [Figure 4] This is a graph showing the measurement results of film BDE using the flat-plate electrode method. [Modes for carrying out the invention]

[0009] The insulating resin of this embodiment comprises (A) a thermoplastic resin and (B) a metal diketone complex crosslinked by ether bonds.

[0010] (A) Thermoplastic resin As the thermoplastic resin used in the present invention, at least one selected from polycarbonate resins, polyester resins, and polyarylate resins which is one type of aromatic polyester resin is preferably used. Further, a copolymer or a mixed resin containing any of these plurality of types of resins may also be used. These resins are excellent in heat resistance, and by using these resins, an insulating resin excellent in heat resistance can be obtained.

[0011] Regarding each of the above resins, for example, in the case of a polycarbonate resin, a polymer having a repeating unit represented by General Formula (1), and in the case of a polyester resin or a polyarylate resin, a polymer having a repeating unit represented by General Formula (2) or (3) can be cited as an example.

[0012]

Chemical Formula

[0013] In General Formula (1), X represents at least one selected from an aliphatic divalent group, a cycloaliphatic divalent group, and a divalent group represented by General Formula (4). In General Formula (2) or (3), X represents at least one selected from the divalent groups represented by General Formula (4). In General Formula (3), Y represents a substituted or unsubstituted arylene group.

[0014] In General Formula (4), R1 and R2 each independently represent a substituted or unsubstituted alkyl group, an aryl group, or a halogen atom. A represents a single bond, a linear, branched, or cyclic alkylene group having 1 to 12 carbon atoms.

[0015] <了 Specific examples of X in the above General Formulas (1), (2), and (3) include, for example, divalent groups represented by General Formulas (5a) to (5n).

[0016]

Chemical Formula

[0017] (B) Metal diketone complex crosslinked by ether bond The metal diketone complex crosslinked by ether bond in the present invention is an oligomeric metal diketone complex having a structure in which two or more metal diketone complexes are crosslinked by ether bonds. The metal diketone complex before crosslinking (hereinafter, when simply referred to as metal diketone complex, it means the metal diketone complex before crosslinking) is a complex in which at least a ligand containing diketone is coordinated to a central metal by one or more. A diketone is a β-dicarbonyl compound having two carbonyl groups at the β-position in the molecule, and in the metal diketone complex, a coordination bond with the central metal occurs through these two carbonyl groups.

[0018] The chemical structural formula of the metal diketone complex crosslinked by ether bond of one embodiment of the present invention is shown below.

[0019] (Chemical formula 3) X - [Zr(AcAc)2 - CH2CH2OCH2CH2O - ] n (Zr(AcAc)2) - Y ··· (6)

[0020] Here, n is 1 to 5. The terminal is any of H, -OCH2CH2OCH2CH2OH, or acetylacetone.

[0021] In formula (6), as a specific example, tetravalent Zr is used as the central metal, two acetylacetones are coordinated to each Zr, and the remaining two are bonded by an ether bond, and the metal diketone complex is crosslinked by an ether bond.

[0022] For example, when n is 1, Zr is a dimer of 2. When n is 2, Zr is a trimer of 3. Also, although not shown in the above chemical formula, there may be cases where both ends are acetylacetone.

[0023] When n is 1 or more, an effect of improving the breakdown electric field can be obtained. When n is 5 or less, the dispersibility in the thermoplastic resin is good.

[0024] Metal diketone complexes bridged by ether bonds are not particularly limited as long as the central metal of the metal diketone complex is bridged by an ether bond. For example, metal diketone complexes have a structure in which two central metals are linked by -ORO- (where R is an alkylene group such as ethylene, propylene, or butylene, an alkylene group having an ether bond inside) as described above.

[0025] The metal diketone complex crosslinked by ether bonds is linear, consisting of two or more metal diketone complexes bonded together, but may also be branched. Mixtures of these may also be used. Preferably, from the viewpoint of solubility in thermoplastic resins and the effect of improving the dielectric breakdown field, it is linear and in the form of 2 to 5-mers.

[0026] In a metal diketone complex crosslinked by ether bonds, the central metal is at least one selected from Zr, Mo, V, Zn, Ti, and Al. The metal diketone complex crosslinked by ether bonds is dispersed in a thermoplastic resin, and the dielectric strength of the insulating resin is improved by oxygen capture by the central metal. In addition to the above, other central metals such as Cu, Fe, Ni, Ca, Co, Mn, Mg, Ir, In, Cr, or La may also be present.

[0027] In a metal diketone complex crosslinked by an ether bond, the diketone is not particularly limited as long as it coordinates to the central metal. The ligands of the metal diketone complex crosslinked by an ether bond are the same as those of the metal diketone complex before crosslinking, and may include one or more β-diketones as ligands. As for the diketone, as described above, it is a β-dicarbonyl compound having two carbonyl groups at the β position in the molecule, and examples include at least one selected from acetylacetonate (acetylacetone), dibenzoylmethane, ethyl acetoethyl, and diethyl malonate. In a metal diketone complex crosslinked by an ether bond, the number of ligands of the original metal diketone complex decreases by the amount used for bonding.

[0028] By incorporating a metal diketone complex crosslinked by ether bonds into the above-mentioned thermoplastic resin, the following two effects can be obtained.

[0029] (1) The dielectric breakdown field improvement effect can be uniformly exerted throughout the film, thereby improving the dielectric breakdown field of the thermoplastic resin film. Conventional metal diketone complex additives tended to aggregate in thermoplastic resins, causing the metal diketone complex to vary within the thermoplastic resin, and preventing the dielectric breakdown field improvement effect from being uniformly exerted throughout the thermoplastic resin film. As a result, the dielectric breakdown field of the dielectric film decreased. By using a metal diketone complex crosslinked by ether bonds instead of a conventional metal diketone complex, the metal diketone complex is oligomerized, so the central metal is not disordered and can be dispersed at a certain distance. This reduces aggregation and sparse areas of the central metal, reducing localized electric field concentration, and as a result, the dielectric breakdown field can be improved overall.

[0030] Figure 1 is a conceptual diagram showing the position of the central metal of a metal diketone complex in a thermoplastic resin film when a conventional metal diketone complex is replaced with a metal diketone complex crosslinked by an ether bond.

[0031] In Figure 1, the left figure shows the state when using a conventional metal diketone complex, and the right figure shows the state when using a metal diketone complex crosslinked by ether bonds. The black circles represent a single central metal. In the left figure, the central metals are scattered, and there are dense and sparse areas of central metals in the thermoplastic resin, indicating poor dispersibility of the metal diketone complex. In the right figure, a dimer with two central metals is shown, and the central metals are separated by a certain distance, indicating that the metal diketone complex crosslinked by ether bonds is more uniformly arranged in the thermoplastic resin. As a result, the conventional localized electric field concentration shown in the left figure can be prevented, and the dielectric breakdown field can be improved.

[0032] (2) Even when the dielectric film is heated, the molecular chains of the polymer, which are the main component of the dielectric film, are less likely to decompose. Conventional additives had molecular structures that readily reacted with the functional groups of the polymer chains (for example, polyarylate resin) that were the main component. When the dielectric film was heated, the molecular chains of the polymer, which are the main component of the dielectric film, decomposed, and the dielectric film deteriorated. Since the metal diketone complex crosslinked by ether bonds is a liquid, it disperses easily in thermoplastic resins, eliminating the need to add acetylacetone as a dispersion aid. Therefore, the decomposition of polyarylate resin at high temperatures caused by acetylacetone can be reduced. In addition, because it is a metal diketone complex crosslinked by ether bonds, the steric hindrance of the molecular structure is significant, making it difficult for it to approach the polymer chains, and thus suppressing the progress of the decomposition reaction of the polymer chains. As a result of these factors, the resistance of the dielectric film is thought to have been strengthened.

[0033] Figure 2 shows the chemical formulas illustrating the decomposition process of polyarylate resin by metal diketone complexes. The decomposition process of polyarylate resin is shown in equations 8 to 10. The central metal of the metal diketone complex approaches the carbonyl group of the polyarylate resin (equation 8), Zr bonds to the carbonyl group, and acetylacetone is removed (equation 9). Furthermore, the polyarylate resin at this site is decomposed by water into carboxylic acid and OH (equation 10). Because the metal diketone complex is crosslinked by ether bonds, steric hindrance makes it difficult for the central metal to approach the carbonyl group of the polyarylate resin, and as a result, the decomposition of the polyarylate resin is inhibited.

[0034] Metal diketone complexes crosslinked by ether bonds can be produced by ligand exchange reactions by heating, ligand exchange reactions by ultraviolet irradiation, nucleophilic substitution reactions with weak bases, and ligand exchange reactions by microwaves and ultrasound. While there are no limitations on the production method as long as the structure is as described above, ligand exchange reactions by heating of the metal diketone complex are preferred due to their high ligand exchange efficiency.

[0035] The following describes a method for obtaining a metal diketone complex bridged by an ether bond through a ligand exchange reaction by heating the metal diketone complex. This method involves exchanging the diketone present in the metal diketone complex with a polyol such as a diol.

[0036] The metal diketone complex used has the same central metal and ligand as described in the section on metal diketone complexes bridged by ether bonds. That is, the central metal is at least one selected from Zr, Mo, V, Zn, Ti, and Al. In addition to the above, other metals such as Cu, Fe, Ni, Ca, Co, Mn, Mg, Ir, In, Cr, or La may also be present as the central metal.

[0037] The ligand is not particularly limited as long as it coordinates to the central metal mentioned above. The ligand may contain one or more β-diketones. The diketone is a β-dicarbonyl compound having two carbonyl groups at the β position in the molecule, as described above, and includes, for example, at least one selected from acetylacetonate (acetylacetone), dibenzoylmethane, ethyl acetoethyl, and diethyl malonate.

[0038] A metal diketone complex may consist of all diketones of the same type, or it may consist of multiple types of diketones. For example, when the central metal is Zr, four diketones are coordinated to form a metal diketone complex. Its chemical structure is shown in Equation 11.

[0039] [ka]

[0040] In formula 11, all four ligands of Zr are acetylacetonates, and the metal diketone complex is Zracetylacetonate. When multiple types of diketones are coordinated, some of the acetylacetonates may be substituted with other diketones. For example, one of the four acetylacetonates may be substituted with dibenzoylmethane.

[0041] The polyol is not limited as long as it can be formed by ligand exchange with a metal diketone complex to create an ether bond, but examples include diols and triols. Preferably, it is a diol having 2 to 6 carbon atoms. Specifically, examples include alkylene glycols such as ethylene glycol, propylene glycol, and n-butylene glycol, and alkylene glycols having an ether bond inside, such as diethylene glycol and triethylene glycol.

[0042] The metal diketone complex, crosslinked by ether bonds, is preferably reacted using the above-mentioned starting materials under the following conditions. 1. Mix 1 mole of a metal alkoxide complex, such as zirconium tetraalkoxide, with 1.5 moles of a diketone, such as acetylacetone. 2. Heat the mixture and stir at 80-95°C for 24-48 hours to carry out a ligand exchange reaction in which the alkoxide is replaced with a diketone. To further accelerate the ligand exchange reaction, degas the mixture at the same temperature under reduced pressure of -0.06 to -0.02 MPa until no more bubbles (alcohol) are produced. This yields the metal diketone complex described above. 3. Once bubbles stop forming, add 1.5 moles of a diol such as diethylene glycol and stir. Increase the temperature to 100-120°C and continue stirring at the same temperature for 24-48 hours to carry out a ligand exchange reaction in which diketones are replaced with diols. To further promote the ligand exchange reaction (crosslinking reaction), degas the mixture under reduced pressure of -0.06 to -0.02 MPa at the same temperature until no more bubbles (diketones) form. 4. The temperature is further increased to 170-220°C (referred to as the crosslinking completion temperature), and the mixture is allowed to stand for 30 minutes to 1 hour to complete the crosslinking reaction, yielding a metal diketone complex crosslinked by ether bonds.

[0043] The central metal of the metal diketone complex bridged by ether bonds obtained by the above method is bonded to both the diketone and the ether bond. The number of diketone and ether bonds, i.e., the state of bridgedness, varies depending on the valence of the central metal, but can be controlled to some extent by the type and amount of polyol added to the metal diketone complex and the reaction temperature. If one ligand is exchanged, mainly dimers are formed, but if two ligands are exchanged, mainly linear trimers are formed. If three to four ligands are exchanged, branched bridgedness occurs.

[0044] Furthermore, the degree of crosslinking and the resulting crosslinked state vary depending on the temperature during the crosslinking completion reaction described in item 4 above. This also affects the dispersibility in thermoplastic resins. The preferred crosslinking completion temperature is 170-190°C. At this temperature, a balance is struck between the degree of crosslinking and dispersibility in thermoplastic resins, resulting in the best possible improvement in dielectric breakdown field.

[0045] The insulating resin of this embodiment is obtained by blending (A) a thermoplastic resin with (B) a metal diketone complex crosslinked by ether bonds. In insulating resins, the content of metal diketone complexes crosslinked by ether bonds is 0.1 to 10% by mass relative to the thermoplastic resin (A). When the content of metal diketone complexes crosslinked by ether bonds is between 0.1% by mass and 10% by mass, the dielectric breakdown field improves.

[0046] The insulating resin of this embodiment may further contain various components depending on the intended use and the type of electronic component used. For example, when the insulating resin is used as a dielectric film for a film capacitor, it may further contain at least one of (C) diketone, alcohol, or carboxylic acid as an additive. Additive (C) can improve the oxidation suppression effect of the thermoplastic resin.

[0047] (C) Diketones, alcohols, or carboxylic acids A dielectric film can be obtained, for example, by dissolving a thermoplastic resin and a metal diketone complex crosslinked by ether bonds in a solvent and forming a film from the resin solution. Here, the metal diketone complex crosslinked by ether bonds may exhibit poor solubility in solvents in which the thermoplastic resin is soluble, which can reduce its dispersibility. By adding a diketone, alcohol, or carboxylic acid, the metal diketone complex crosslinked by ether bonds can be highly dispersed in the thermoplastic resin. High dispersion of the metal diketone complex crosslinked by ether bonds in the thermoplastic resin increases the probability of oxygen capture by the central metal, improving the oxidation suppression effect of the thermoplastic resin and improving the dielectric breakdown field of the dielectric film. Below, a dielectric film is described as one example of an application of the insulating resin of this disclosure, but the applications are not limited to this.

[0048] (C-1) Diketone The diketone additive may be added separately from the diketone ligand of the metal diketone complex crosslinked by the ether bond described above. The diketone additive may exist as a single compound in the resin solution and dielectric film. Some of the diketone additive may form a complex as a ligand for some of the metal diketone complex crosslinked by the ether bond.

[0049] The diketone used as an additive may be the same as the diketone used as a ligand described above. For example, a β-diketone or a ketoacetic acid ester may be used. As a β-diketone, for example, at least one of acetylacetonate (acetylacetone) or dibenzoylmethane may be used. As a ketoacetic acid ester, for example, at least one of ethyl acetoacetate or diethyl malonate may be used. The diketone used as an additive may be the same compound as the diketone used as a ligand described above, or a different compound may be used. For example, even if acetylacetone is used as the diketone in the metal diketone complex crosslinked by ether bonds, the same compound acetylacetone may be used as an additive, or a different compound dibenzoylmethane may be used. If a different compound is used, the diketone additive may be substituted for some of the ligands of the metal diketone complex crosslinked by ether bonds in the resin solution and dielectric film.

[0050] In the dielectric film of this embodiment, the diketone content is, for example, 0.05 to 10% by mass.

[0051] (C-2) Alcohol The alcohol is a monoalcohol. Using alcohol as an additive allows for high dispersion of ether-linked metal diketone complexes in thermoplastic resins. In the resin solution, the alcohol replaces some of the ligands of the ether-linked metal diketone complex. Alcohol-substituted metal diketone complexes have higher solubility in solvents than unsubstituted complexes.

[0052] As the additive alcohol, for example, at least one selected from methanol, ethanol, propanol, butanol, hexanol, 2-ethylhexanol, octanol, nonanol, and decanol can be used. In the dielectric film of this embodiment, the alcohol content is, for example, 0.05 to 10% by mass.

[0053] (C-3)carboxylic acid As the carboxylic acid additive, at least one selected from acetic acid, propionic acid, butyric acid, valeric acid, lauric acid, tridecyl acid, palmitic acid, stearic acid, oleic acid, maleic acid, fumaric acid, succinic acid, citric acid, fumaric acid, lactic acid, tartaric acid, benzoic acid, and phthalic acid can be used. In the dielectric film of this embodiment, the alcohol content is, for example, 0.05 to 10% by mass.

[0054] The dielectric film of this embodiment can be obtained, for example, as follows: A thermoplastic resin is dissolved in a solvent, and a metal diketone complex crosslinked by ether bonds is added to obtain a resin solution. Additional additives may be added as needed. Using this resin solution, a dielectric film can be deposited on a substrate made of, for example, polyethylene terephthalate (PET). Known methods can be used for film deposition, and for example, molding methods selected from the doctor blade method, die coater method, and knife coater method can be used.

[0055] The dielectric film of this embodiment has a thickness of, for example, 0.1 to 10 μm. Furthermore, the dielectric breakdown field strength of the dielectric film for film capacitors, when measured using the flat electrode method specified in JIS-C2151 section 17.2.2 and the measurement method compliant with JIS C2110-2, is 405 to 430 V / μm, compared to a film without additives (365 V / μm) and a general polypropylene film for film capacitors (316 V / μm).

[0056] As a solvent, for example, an organic solvent containing ethylene glycol monopropyl ether, methyl ethyl ketone, methyl isobutyl ketone, xylene, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, dimethylacetamide, cyclohexane, ethylcyclohexane, toluene, chloroform, tetrahydrofuran, or a mixture of two or more selected from these may be used.

[0057] The concentration of thermoplastic resin in the resin solution (resin concentration) is, for example, 1 to 25% by mass. The concentration of metal diketone complexes crosslinked by ether bonds in the resin solution is, for example, 0.015 to 3% by mass. The concentration of diketones, monoalcohols, or carboxylic acids is, for example, 0.005 to 3% by mass.

[0058] While dielectric films were described above as an example of an insulating resin application, insulating resins are not limited to this and can be used in a variety of applications. For example, they can be used as wire and cable coating resins, electronic component sealing resins, insulating paints, and insulating adhesives. In the case of wire and cable coating resins, for example, the insulating resin disclosed herein can be molded into strips or sheets and wrapped around the surface of cables. It can also be molded into tubes and used by inserting cables through them. In the case of sealing resins, for example, entire coils and transformers can be embedded in the insulating resin. Semiconductor elements and electronic components mounted on wiring boards can be coated with insulating resin, or insulating resin can be used to fill the gaps between connection terminals. In the case of insulating paints, for example, they can be used as a resin component in various paints such as solvent-based paints and powder coatings, together with colorants and other necessary components. In the case of insulating adhesives, for example, they can be used as solvent-based adhesives by dissolving the insulating resin in a solvent.

[0059] (Examples) The insulating resin of this disclosure will be described in detail below based on examples. A dielectric film using the insulating resin was used as an example.

[0060] (Manufacturing Example 1) 23.02 g (0.06 mol) of zirconium tetra-n-butoxide and 9.01 g (0.09 mol) of acetylacetone were mixed and stirred. The mixture was heated to 80°C and stirred at the same temperature for 24 hours. Further degassing was carried out at the same temperature under reduced pressure of -0.06 to -0.02 MPa until no more n-butanol bubbles were produced. Once no more bubbles were produced, 9.55 g (0.09 mol) of diethylene glycol was added and the mixture was heated to 100°C while stirring. After stirring at the same temperature for 24 hours, the mixture was degassed at the same temperature under reduced pressure of -0.06 to -0.02 MPa until no more acetylacetone bubbles were produced. After no more bubbles were produced, the temperature was further increased to 200°C and allowed to stand for 30 minutes to complete the crosslinking reaction, yielding a metal diketone complex (KZ-1) crosslinked by ether bonds.

[0061] (Manufacturing example 2) In the same procedure as in Production Example 1, except that the final crosslinking reaction temperature was changed from 200°C to 180°C, a metal diketone complex (KZ-2) crosslinked by ether bonds was obtained.

[0062] (Example 1) Polyarylate was used as the thermoplastic resin, and the metal diketone complex KZ-1, which was crosslinked by ether bonds as prepared in Production Example 1, was used as the metal diketone complex. Polyarylate was dissolved in toluene, and then KZ-1 was dissolved to obtain a resin solution with a thermoplastic resin concentration of 12% by mass. Resin solutions with KZ-1 concentrations of 0.3% by mass and 3.0% by mass were also obtained.

[0063] (Example 2) Resin solutions with concentrations of 0.3% by mass and 3.0% by mass of KZ-2 were obtained in the same manner as in Example 1, except that the ether-linked metal diketone complex KZ-2 prepared in Preparation Example 2 was used instead of the ether-linked metal diketone complex KZ-1.

[0064] (Comparative Example 1) Polyarylate was used as the thermoplastic resin, and a resin solution with a thermoplastic resin concentration of 12% by mass was obtained.

[0065] (Comparative Example 2) A resin solution with a thermoplastic resin concentration of 12% by mass and a zirconium acetylacetone complex concentration of 3.0% by mass was obtained in the same manner as in Example 1, except that a zirconium acetylacetone complex was used instead of the metal diketone complex KZ-1 crosslinked by ether bonds.

[0066] (Rating 1) The above resin solution was applied to a polyethylene terephthalate (PET) substrate using a coater, and the solvent was removed by drying at 125°C for 3 hours to prepare a dielectric film with a thickness of 2.0 μm. These dielectric films were heated under reduced pressure at 160°C, and removed after 0 hours, 48 ​​hours, and 140 hours. The weight-average molecular weight was measured to investigate the change in weight-average molecular weight with respect to heating time. The results are shown in Figure 3.

[0067] Figure 3 is a graph showing the change in weight-average molecular weight of a dielectric film with respect to heating time. The horizontal axis represents heating time (hrs), and the vertical axis represents the weight-average molecular weight. Note that the weight-average molecular weight is The measurement was performed using gel permeation chromatography.

[0068] While the weight-average molecular weight of the unadded sample gradually decreased, the sample with 0.3 wt% KZ-1 and KZ-2 added showed almost no change with heating time. Furthermore, the sample with 3.0 wt% zirconium acetylacetone added saw a decrease in weight-average molecular weight from approximately 86,000 to approximately 65,000 immediately after heating, decreasing to approximately 42,000 after 48 hours of heating and to approximately 39,000 after 140 hours. In contrast, the sample with 3.0 wt% KZ-1 and KZ-2 added saw a decrease in weight-average molecular weight from approximately 86,000 to approximately 60,000 immediately after heating, but only decreased to approximately 53,000 after 48 hours and to approximately 49,000 after 140 hours of heating. In other words, the solution with 3.0 wt% KZ-1 and KZ-2 added showed a significantly smaller decrease in weight-average molecular weight compared to the solution with 3.0 wt% zirconium acetylacetone added, confirming that KZ-1 and KZ-2 have the effect of suppressing the degradation of thermoplastic resins.

[0069] (Example 3) In the same manner as in Example 1, polyarylate was used as the thermoplastic resin, and metal diketone complexes KZ-1 and KZ-2, which were crosslinked by ether bonds as prepared in Production Examples 1 and 2, were used as the metal diketone complexes. The polyarylate was dissolved in toluene, and then KZ-1 and KZ-2 were dissolved to obtain a resin solution with a thermoplastic resin concentration of 12% by mass. Resin solutions with various concentrations of KZ-1 and KZ-2 were obtained.

[0070] (Rating 2) The above-mentioned resin solutions were applied to a polyethylene terephthalate (PET) substrate using a coater, and the solvent was removed by drying at 125°C for 3 hours to produce a dielectric film with a thickness of 2.0 μm. The BDE (dielectric breakdown field strength) of the dielectric film was measured. The measurement method followed the planar electrode method specified in JIS-C2151 section 17.2.2 and JIS C2110-2, with 24 points measured for each film. The test was conducted in a dry air environment with a dew point of approximately -30°C. The results are shown in Figure 4.

[0071] Figure 4 shows graphs of the BDE measurement results for films using the planar electrode method. The graph on the left is for films containing KZ-1, and the graph on the right is for films containing KZ-2. The horizontal axis shows the amount of KZ-1 and KZ-2 added to the polyarylate resin (wt%), and the vertical axis shows BDE (V / μm).

[0072] In all cases, those with 10.0 wt% or less of the additive showed higher BDE values ​​than those without the additive. These results were obtained from measurements at 24 points on the film, indicating that the dielectric breakdown field improvement effect was uniformly exerted throughout the entire film. Although not shown in this graph, the BDE value for the film with 3.0 wt% zirconium acetylacetone added was 392 V / μm. From the graph, KZ-2 (slightly less than 430 V / μm) and KZ-1 (405 V / μm) showed even higher BDE values. This indicates that metal diketone complexes cross-linked by ether bonds exhibit a higher dielectric breakdown field improvement effect than uncross-linked metal diketone complexes.

[0073] Furthermore, as mentioned above, KZ-2 (slightly less than 430V / μm) shows a higher BDE value than KZ-1 (405V / μm). However, the crosslinking completion temperature for KZ-2 (180℃) is lower than that of KZ-1 (200℃). Therefore, it is thought that if the temperature is too high, crosslinking will proceed too much, reducing the dispersibility in the thermoplastic resin. This indicates that 180℃ is a well-balanced crosslinking completion temperature.

[0074] Based on the above, it was confirmed that the insulating resin of this disclosure can uniformly exhibit a dielectric breakdown field improvement effect throughout the entire film, and that film degradation is suppressed even when heated.

[0075] This disclosure can be implemented in the following embodiments (1) to (11).

[0076] (1) An insulating resin comprising (A) a thermoplastic resin and (B) a metal diketone complex crosslinked by an ether bond.

[0077] (2)(B) The insulating resin according to embodiment (1) above, wherein the central metal of the metal diketone complex crosslinked by ether bonds is one of Zr, Mo, V, Zn, Ti, and Al.

[0078] (3)(B) The insulating resin according to embodiment (1) or (2) above, wherein the ligand of the metal diketone complex crosslinked by an ether bond contains one or more β-diketones.

[0079] (4)(B) The insulating resin according to embodiment (3) above, wherein the ligand of the metal diketone complex crosslinked by an ether bond comprises at least one selected from acetylacetonate, dibenzoylmethane, ethyl acetoethyl, and diethyl malonate.

[0080] (5)(C) An insulating resin according to any one of embodiments (1) to (4) above, further comprising at least one of a diketone, an alcohol, or a carboxylic acid.

[0081] (6)(C) The insulating resin according to embodiment (5) above, wherein the diketone is a β-diketone or a ketoacetic acid ester.

[0082] (7) The insulating resin according to embodiment (6), wherein the β-diketone comprises at least one of acetylacetonate or dibenzoylmethane, and the ketoacetic acid ester comprises at least one of ethyl acetoacetate or diethyl malonate.

[0083] (8)(C) The insulating resin according to any one of the above embodiments (1) to (7), wherein the alcohol is at least one selected from methanol, ethanol, propanol, butanol, hexanol, and 2-ethylhexanol, octanol, nonanol, and decanol.

[0084] (9)(A) The thermoplastic resin is an insulating resin according to any one of the above embodiments (1) to (8), wherein the glass transition temperature is 50°C or higher.

[0085] (10)(A) An insulating resin according to any one of the above embodiments (1) to (9), wherein the thermoplastic resin is at least one selected from polycarbonate resin, polyester resin, and polyarylate resin.

[0086] (11)(D) An insulating resin according to any one of the above embodiments (1) to (10), comprising toluene or tetrahydrofuran as a solvent.

Claims

1. An insulating resin comprising (A) a thermoplastic resin and (B) a metal diketone complex crosslinked by ether bonds.

2. (B) The insulating resin according to claim 1, wherein the central metal of the metal diketone complex crosslinked by ether bonds is one of Zr, Mo, V, Zn, Ti, and Al.

3. (B) The insulating resin according to claim 1 or 2, wherein the ligand of the metal diketone complex crosslinked by ether bonds comprises one or more β-diketones.

4. (B) The insulating resin according to claim 3, wherein the ligand of the metal diketone complex crosslinked by an ether bond comprises at least one selected from acetylacetonate, dibenzoylmethane, ethyl acetoethyl, and diethyl malonate.

5. (C) The insulating resin according to claim 1, further comprising at least one of a diketone, an alcohol, or a carboxylic acid.

6. (C) The insulating resin according to claim 5, wherein the diketone is a β-diketone or a ketoacetic acid ester.

7. The insulating resin according to claim 6, wherein the β-diketone comprises at least one of acetylacetonate or dibenzoylmethane, and the ketoacetic acid ester comprises at least one of ethyl acetoacetate or diethyl malonate.

8. (C) The insulating resin according to claim 1, wherein the alcohol is at least one selected from methanol, ethanol, propanol, butanol, hexanol, and 2-ethylhexanol, octanol, nonanol, and decanol.

9. (A) The insulating resin according to claim 1, wherein the thermoplastic resin has a glass transition temperature of 50°C or higher.

10. (A) The insulating resin according to claim 1, wherein the thermoplastic resin is at least one selected from polycarbonate resin, polyester resin, and polyarylate resin.

11. (D) The insulating resin according to claim 1, comprising toluene or tetrahydrofuran as a solvent.

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