Resin composition, coated film using the same, and electrolyte

Abstract

The present invention relates to a resin composition comprising a polycarbonate resin containing structural units represented by general formula (1); and a carbonate-based organic solvent, wherein R1 to R4 and R 11 14 independently represent hydrogen, fluorine, chlorine, bromine, iodine or the like, a is an integer of 1 to 1,000, X represents -S- or the like, the content of the polycarbonate resin in the resin composition is 0.05 to 50% by mass, the content of the carbonate-based organic solvent in the resin composition is 50 to 99.5% by mass, and the total proportion of structural units represented by formulae (2) to (4) among all the structural units represented by general formula (1) is 0 to 75% by mole ratio.​

Description

Technical Field

[0001] This invention relates to a resin composition with low toxicity that can be easily applied as an ink or coating, and to coatings and electrolytes using the resin composition. Background Technology

[0002] It is known that specific polycarbonate resins are dissolved in organic solvents for use in inks, coatings, etc., in which various organic solvents are used. In recent years, halogenated organic solvents and solvents such as toluene and 1,4-dioxane, which may pose safety concerns to humans, are being replaced by safer solvents (Patent Document 1).

[0003] On the other hand, carbonate solvents such as dimethyl carbonate and ethylene carbonate are relatively safe, especially as their applications are expanding towards becoming electrolyte solvents for lithium-ion batteries. However, when used as polycarbonate electrolytes, the low solubility of polycarbonate resin in carbonate solvents makes it difficult to obtain a coating film, leaving room for improvement. To address these issues, various studies have been conducted; for example, a scheme has been proposed to add dichloromethane as a solvent to form a colloidal solution for coating (Patent Document 2). However, since dichloromethane is a halogenated solvent with a high environmental impact, it may pose safety concerns for humans.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: WO2018 / 123282 Publication

[0007] Patent Document 2: Japanese Patent Application Publication No. 2000-357533 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] The objective of this invention is to provide a resin composition with low toxicity that is easy to apply as an ink or coating, as well as a coating film and an electrolyte using the resin composition.

[0010] Although the inventors have noticed carbonate-based organic solvents with low toxicity, since carbonate-based organic solvents cannot dissolve conventional bisphenol A type polycarbonate resins, it is necessary to improve the solvent solubility of polycarbonate resins themselves and combine them with the optimal carbonate-based solvents in order to dissolve polycarbonate resins.

[0011] Technical solutions for solving the problem

[0012] The inventors conducted repeated and in-depth research to solve the above-mentioned problems, and found that polycarbonate resins with specific structural units have excellent solubility in carbonate-based organic solvents with low toxicity, thus completing the present invention.

[0013] That is, the present invention is as follows.

[0014] <1> A resin composition comprising: a polycarbonate resin containing structural units of general formula (1); and a carbonate-based organic solvent.

[0015]

[0016] In the formula, R1~R4 and R 11 ~R 14 Each of these can independently represent hydrogen, fluorine, chlorine, bromine, or iodine, or can have substituents, namely alkyl with 1 to 20 carbon atoms, aryl with 6 to 12 carbon atoms, alkenyl with 2 to 12 carbon atoms, alkoxy with 1 to 5 carbon atoms, or aralkyl with 7 to 17 carbon atoms, where a is an integer from 1 to 1,000.

[0017] X is

[0018] -S-、-(CH2) b -, -O-, -SO-, -CO-, -SO2-,

[0019]

[0020] Wherein, R5 and R6 independently represent hydrogen, fluorine, chlorine, bromine, or iodine, or may be alkyl with 1 to 20 carbon atoms, alkoxy with 1 to 5 carbon atoms, or aryl with 6 to 12 carbon atoms, respectively, or R5 and R6 may be bonded to form a carbon ring with 5 to 20 carbon atoms or a heterocycle with 5 to 12 elements.

[0021] R7 and R8 independently represent hydrogen, fluorine, chlorine, bromine, or iodine, or, respectively, alkyl groups having 1 to 9 carbon atoms, alkoxy groups having 1 to 5 carbon atoms, alkenyl groups having 2 to 12 carbon atoms, or aryl groups having 6 to 12 carbon atoms, which may have substituents.

[0022] b represents an integer from 0 to 20.

[0023] The content of the polycarbonate resin in the above resin composition is 0.05% to 50% by mass.

[0024] The content of the above-mentioned carbonate-based organic solvent in the above-mentioned resin composition is 50-99.5% by mass.

[0025] The total proportion of the structural units shown in formulas (2) to (4) of all structural units shown in the above general formula (1) is 0% to 75% in molar ratio.

[0026]

[0027] <2> As mentioned above <1> The resin composition wherein the content of the carbonate-based organic solvent in the resin composition is 70-99% by mass.

[0028] <3> As mentioned above <1> or <2> The resin composition wherein the carbonate-based organic solvent comprises at least one selected from dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate.

[0029] <4> As mentioned above <3> The resin composition further comprises ethylene carbonate in the carbonate-based organic solvent.

[0030] <5> As mentioned above <1> ~ <4> The resin composition described in any one of the above general formulas (1) comprises one or more structural units selected from those shown in formulas (5) to (9) below.

[0031]

[0032] <6> As mentioned above <5> The resin composition wherein the structural unit represented by the above general formula (1) comprises one or more structural units selected from those represented by formulas (5), (6) and (8).

[0033] <7> As mentioned above <1> ~ <6> The resin composition according to any one of the following methods, wherein the polycarbonate resin has an intrinsic viscosity of 0.3 to 2.0 dl / g.

[0034] <8> As mentioned above <1> ~ <7> The resin composition according to any one of the above-mentioned resin compositions, wherein the resin composition does not contain any organic solvent other than the above-mentioned carbonate-based organic solvents.

[0035] <9> A coating film, wherein the coating film is formed by applying the above-mentioned... <1> ~ <8> The resin composition described in any one of the above is dried.

[0036] <10> An electrolyte, wherein the electrolyte is in the above-mentioned <1> ~ <8> The resin composition described in any one of the above methods contains an electrolyte of 0.1 to 30% by mass of lithium salt dissolved in it.

[0037] <11> As mentioned above <10> The electrolyte, wherein the lithium salt comprises at least one of LiPF6 and C2F6LiNO4.

[0038] <12> A polymeric gel electrolyte, wherein the polymeric gel electrolyte is formed by... <10> or <11> The electrolyte is obtained by gelling the electrolyte solution.

[0039] <13> As mentioned above <12> The polymeric gel electrolyte, wherein the conductivity of the polymeric gel electrolyte is 1 to 30,000 μS / cm.

[0040] Invention Effects

[0041] Compared to conventional polycarbonate resin solutions, the resin composition of the present invention is not only less toxic, but also readily applicable as an ink or coating, suitable for forming coatings on various substrates. Furthermore, it possesses advantages such as good compatibility with lithium salts, conductivity even when the polycarbonate resin is in a dissolved state, and the ability to function as an electrolyte. Detailed Implementation

[0042] The present invention will be described in detail below with embodiments and examples. However, the present invention is not limited to the embodiments and examples described below. Any modifications can be made to the implementation without departing from the essential points of the present invention.

[0043] [Resin Composition]

[0044] The resin composition of the present invention comprises a polycarbonate resin containing structural units of general formula (1); and a carbonate-based organic solvent.

[0045]

[0046] The content of the polycarbonate resin in the above resin composition is 0.05 to 50% by mass, the content of the carbonate-based organic solvent in the above resin composition is 50 to 99.5% by mass, and the total proportion of the structural units shown in formulas (2) to (4) among all the structural units shown in the above general formula (1) is 0 to 75% by molar ratio.

[0047]

[0048] In the above general formula (1), R1~R4 and R 11 ~R 14 Each can independently represent hydrogen, fluorine, chlorine, bromine or iodine, or can have substituents, namely alkyl with 1 to 20 carbon atoms, aryl with 6 to 12 carbon atoms, alkenyl with 2 to 12 carbon atoms, alkoxy with 1 to 5 carbon atoms or aralkyl with 7 to 17 carbon atoms.

[0049] It should be noted that, in this specification, the "substituents" that "may have substituents" can include "fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, alkyl groups with 1 to 7 carbon atoms, aryl groups with 6 to 12 carbon atoms, alkenyl groups with 2 to 7 carbon atoms, alkoxy groups with 1 to 5 carbon atoms, and aralkyl groups with 7 to 17 carbon atoms" (the same applies below).

[0050] a is an integer from 1 to 1,000, preferably an integer from 10 to 900, and more preferably an integer from 30 to 600.

[0051] X is

[0052] -S-、-(CH2) b -, -O-, -SO-, -CO-, -SO2-,

[0053]

[0054] Wherein, R5 and R6 independently represent hydrogen, fluorine, chlorine, bromine, or iodine, or may be alkyl with 1 to 20 carbon atoms, alkoxy with 1 to 5 carbon atoms, or aryl with 6 to 12 carbon atoms, respectively, or R5 and R6 may be bonded to form a carbon ring with 5 to 20 carbon atoms or a heterocycle with 5 to 12 elements.

[0055] R7 and R8 independently represent hydrogen, fluorine, chlorine, bromine, or iodine, or, respectively, alkyl groups having 1 to 9 carbon atoms, alkoxy groups having 1 to 5 carbon atoms, alkenyl groups having 2 to 12 carbon atoms, or aryl groups having 6 to 12 carbon atoms, which may have substituents.

[0056] b represents an integer from 0 to 20, preferably an integer from 1 to 15, and more preferably an integer from 1 to 10.

[0057] In this invention, the structural unit shown in the above general formula (1) preferably includes one or more structural units selected from the structural units shown in formulas (5) to (9) below.

[0058]

[0059] Particularly preferred is that, in this invention, the structural unit shown in the above general formula (1) includes one or more structural units selected from those shown in formulas (5), (6) and (8).

[0060] In this invention, the total proportion of the structural units shown in formulas (2) to (4) in all structural units shown in the general formula (1) is 0 to 75%, preferably 0 to 70%, and more preferably 0 to 60% in molar ratio. Since the lower limit value of the structural units shown in formulas (2) to (4) is 0%, the structural units shown in the general formula (1) may not include these structural units, so these are arbitrary structural units. Among them, the structural unit shown in formula (2) is a structural unit derived from 2,2-bis(4-hydroxyphenyl)propane (BPA), the structural unit shown in formula (3) is a structural unit derived from 1,1-bis(4-hydroxyphenyl)cyclohexane (BPZ), and the structural unit shown in formula (4) is a structural unit derived from 1,1-bis(4-hydroxyphenyl)-1-phenylethane (BPAP).

[0061] When the structural unit represented by general formula (1) consists only of structural units derived from 2,2-bis(4-hydroxyphenyl)propane (BPA), 1,1-bis(4-hydroxyphenyl)cyclohexane (BPZ), and / or 1,1-bis(4-hydroxyphenyl)-1-phenylethane (BPAP) (i.e., the molar ratio is 100%), or when the proportion of these structural units is large, i.e., the molar ratio is greater than 75%, its solubility in carbonate-based organic solvents will decrease. The molar ratio of each structural unit can be determined based on the molar ratio of the monomers used in the synthesis of polycarbonate resin. Alternatively, the molar ratio can also be calculated by analysis such as nuclear magnetic resonance spectroscopy.

[0062] <Polycarbonate resin>

[0063] The polycarbonate resin used in the resin composition of the present invention can be manufactured by reacting a bisphenol derived from the structural unit represented by general formula (1) with a carbonate-forming compound. Therefore, it can be manufactured using known methods used in the manufacture of bisphenol A-derived polycarbonate resins, such as the direct reaction of bisphenols with phosgene (phosgene method) or the transesterification reaction of bisphenols with diaryl carbonates (transesterification method).

[0064] The bisphenols used as raw material monomers for the polycarbonate resin in the resin compositions of the present invention are compounds represented by the following general formula (11):

[0065]

[0066] (In the formula, R1~R4, R11~R14 and X have the same meaning as in general formula (1).)

[0067] Examples of monomers represented by general formula (11) include 4,4'-biphenyl, bis(4-hydroxyphenyl)methane, bis(2-hydroxyphenyl)methane, 2,4'-dihydroxydiphenylmethane, bis(4-hydroxyphenyl) ether, bis(4-hydroxyphenyl) sulfone, 2,4'-dihydroxydiphenyl sulfone, bis(2-hydroxyphenyl) sulfone, bis(4-hydroxy-3-methylphenyl) sulfone, bis(4-hydroxyphenyl) sulfoxide, bis(4-hydroxyphenyl) sulfide, bis(4-hydroxyphenyl) ketone, and 1,1-bis(4-hydroxyphenyl) Ethane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, bis(4-hydroxyphenyl)diphenylmethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 1,1-bis(4-hydroxy-3-methylphenyl)ethane, bis(4-hydroxy-3-methylphenyl)methane, 2,2-bis(4-hydroxy-3-tert-butylphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)hexafluoropropane, 1,1- bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)cycloundecane, 1,1-bis(4-hydroxyphenyl)cyclododecane, 2,2-bis(4-hydroxy-3-allylphenyl)propane, 3,3,5-trimethyl-1,1-bis(4-hydroxyphenyl)cyclohexane, 9,9-bis(4-hydroxy-3-ethylphenyl)fluorene, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 9,9-bis(4-hydroxyphenyl)fluorene, Examples include 4,4'-[1,4-phenylenebis(1-methylethylene)]bisphenol, 4,4'-[1,3-phenylenebis(1-methylethylene)]bisphenol, 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4-hydroxyphenyl)-2-ethylhexane, 1,1-bis(4-hydroxyphenyl)-2-methylpropane, 2,2-bis(4-hydroxyphenyl)-4-methylpentane, 1,1-bis(4-hydroxyphenyl)decane, and 1,3-bis(4-hydroxyphenyl)-5,7-dimethyladamantane. Two or more of these can also be used in combination.

[0068] Among them, bis(4-hydroxyphenyl)methane (BPF), 2,2-bis(4-hydroxyphenyl)propane (BPA), 2,2-bis(4-hydroxy-3-methylphenyl)propane (BPC), 1,1-bis(4-hydroxyphenyl)cyclohexane (BPZ), 1,1-bis(4-hydroxyphenyl)-1-phenylethane (BPAP), 3,3,5-trimethyl-1,1-bis(4-hydroxyphenyl)cyclohexane (TMC), 2,2-bis(4-hydroxyphenyl)-4-methylpentane (MIBK) and 2,2-bis(4-hydroxyphenyl)hexafluoropropane (BPAF) are particularly preferred.

[0069] It should be noted that 2,2-bis(4-hydroxyphenyl)propane (BPA), 1,1-bis(4-hydroxyphenyl)cyclohexane (BPZ), and 1,1-bis(4-hydroxyphenyl)-1-phenylethane (BPAP) are not preferred because they have low solubility in dimethyl carbonate, diethyl carbonate, and methyl ethyl carbonate, which are common carbonate-based organic solvents, when used alone. Therefore, when 2,2-bis(4-hydroxyphenyl)propane (BPA), 1,1-bis(4-hydroxyphenyl)cyclohexane (BPZ), or 1,1-bis(4-hydroxyphenyl)-1-phenylethane (BPAP) are used as monomers represented by the above general formula (11), the amount of 2,2-bis(4-hydroxyphenyl)propane (BPA), 1,1-bis(4-hydroxyphenyl)cyclohexane (BPZ), and 1,1-bis(4-hydroxyphenyl)-1-phenylethane (BPAP) in the monomers represented by the above general formula (11) is 0 to 75% in molar ratio, preferably 0 to 70%, and more preferably 0 to 60%.

[0070] Furthermore, when solubility in the electrolyte is of interest, the preferred materials are selected from 2,2-bis(4-hydroxyphenyl)propane (BPA), 1,1-bis(4-hydroxyphenyl)cyclohexane (BPZ), 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxyphenyl)-4-methylpentane (MIBK) and 2,2-bis(4-hydroxyphenyl)hexafluoropropane (BPAF).

[0071] In the phosgene process, the monomer represented by the above general formula (11) is typically reacted with phosgene in the presence of an acid binder and a solvent. As an acid binder, pyridine or hydroxides of alkali metals such as sodium hydroxide or potassium hydroxide can be used, while as a solvent, dichloromethane or chloroform can be used. Furthermore, to promote the polycondensation reaction, a catalyst such as a tertiary amine such as triethylamine or a quaternary ammonium salt such as benzyltriethylammonium chloride is preferably added. Additionally, to adjust the degree of polymerization, monofunctional compounds such as phenol, p-tert-butylphenol, p-cumylphenol, p-hydroxyphenylethanol, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and long-chain alkyl-substituted phenols are preferably added as molecular weight regulators. Additionally, small amounts of antioxidants such as sodium sulfite or dithionite and / or branching agents such as phloroglucinol or indomethacin bisphenol can be added as needed. The reaction is typically set within a range of 0–150°C, preferably 5–40°C. Although the reaction time depends on the reaction temperature, it is typically 0.5 minutes to 10 hours, preferably 1 minute to 2 hours. Furthermore, it is preferable to maintain the pH of the reaction system above 10 during the reaction process.

[0072] On the other hand, in the transesterification process, the monomer shown in the above general formula (11) is mixed with a diaryl carbonate and reacted under reduced pressure at high temperature. Examples of diaryl carbonates include diphenyl carbonate, di-p-toluene carbonate, phenyl-p-toluyl carbonate, di-p-chlorophenyl carbonate, and dinaphthalene carbonate. Two or more of these compounds may also be used in combination. The reaction is usually carried out at a temperature in the range of 150 to 350°C, preferably 200 to 300°C. In addition, the vacuum level is preferably ultimately reduced to below 1 mmHg, and the phenols generated from the diaryl carbonate through the transesterification reaction are distilled out of the system. Although the reaction time depends on the reaction temperature, vacuum level, etc., it is usually on the order of 1 to 24 hours. The reaction is preferably carried out in an environment of inert gas such as nitrogen or argon. In addition, molecular weight regulators, antioxidants, or branching agents may be added as needed to carry out the reaction.

[0073] The polycarbonate resin used in the resin composition of the present invention preferably maintains a good balance in terms of solvent solubility, ease of application, peelability, scratch resistance, and impact resistance, which are required for use as a coating film forming resin. By setting the lower limit of the intrinsic viscosity of the resin above a specified value, scratch resistance and impact resistance are improved; by setting the upper limit of the intrinsic viscosity below a specified value, the decrease in solvent solubility and the increase in solution viscosity can be suppressed, thus maintaining ease of application. The intrinsic viscosity of the polycarbonate resin is preferably in the range of 0.3 to 2.0 dl / g, more preferably in the range of 0.35 to 1.5 dl / g.

[0074] The amount of polycarbonate resin in the resin composition of the present invention is 0.05 to 50% by mass. In the case of coating applications, this amount is preferably 1 to 30% by mass, more preferably 1 to 20% by mass, depending on intrinsic viscosity and solvent solubility. When the amount of polycarbonate resin is within this range, a good balance is achieved between solvent solubility and ease of application, resulting in improved workability and appearance. On the other hand, when the resin composition of the present invention is used as an electrolyte, the amount of polycarbonate resin is preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass. Although this also depends on the lithium salt concentration, when it exceeds 10% by mass, polycarbonate resin may precipitate.

[0075] <Carbonate-based organic solvents>

[0076] The resin composition of the present invention is a solution obtained by dissolving the above-mentioned polycarbonate resin in a carbonate-based organic solvent, and its state is equivalent to that of a paint commonly referred to as transparent. The resin composition of the present invention can also be used to prepare a colored paint composition by further dissolving or dispersing the desired dyes and / or pigments.

[0077] In the resin composition of the present invention, at least a carbonate-based organic solvent is used as the solvent. Specific examples of carbonate-based organic solvents include dimethyl carbonate (hereinafter referred to as "DMC"), diethyl carbonate (hereinafter referred to as "DEC"), methyl ethyl carbonate (hereinafter referred to as "MEC"), ethylene carbonate (hereinafter referred to as "EC"), propylene carbonate, vinylene carbonate, fluoroethylene carbonate, etc., which are linear carbonates; in the present invention, two or more of these organic solvents may be used in combination. Preferably, it contains one or more of DMC, DEC, and MEC, which have relatively high solubility for polycarbonate resins. Furthermore, the carbonate-based organic solvent used in the present invention preferably contains at least one selected from DMC, DEC, and MEC, as well as ethylene carbonate. In this case, considering that polycarbonate resins are prone to precipitation, the content of ethylene carbonate in the carbonate-based organic solvent is preferably less than 50% by mass.

[0078] In this invention, the content of carbonate-based organic solvent in the resin composition is 50-99.95% by mass, preferably 70-99% by mass, more preferably 75-99% by mass, and particularly preferably 80-99% by mass.

[0079] In this invention, it is preferred to use a solvent formed solely from a combination of carbonate-based organic solvents. However, in the case of preparing a coating solution, any organic solvent may be added as long as it does not impair the effects of this invention and is not a toxic or hazardous substance as defined by the Japanese Toxic and Hazardous Substances Control Law, nor a special chemical substance as defined by the Japanese Occupational Safety and Health Law. Specifically, the content of organic solvents other than carbonate-based organic solvents in the resin composition of this invention may be from 0% to 30% by mass.

[0080] Furthermore, when the resin composition of the present invention is intended for use as an electrolyte, organic solvents with minimal impact on the electrolyte, such as acetonitrile, tetraethylene glycol dimethyl ether, and sulfolane, may be added for purposes such as solubility and viscosity adjustment, without compromising the effects of the present invention. Specifically, the content of organic solvents other than carbonate-based organic solvents in the resin composition of the present invention can be from 0% to 30% by mass.

[0081] <Optional Additives>

[0082] When the resin composition of the present invention is used for coating, pigments, dyes, colored particles, and particles with optical coherence can be added to enhance the coloring effect. Examples of pigments and dyes include azo pigments and phthalocyanine pigments, which are organic pigments; specifically, examples include Red 104, Red 106, Red 201, Red 202, Red 204, Red 215, Red 220, Orange 203, Orange 204, Blue 1, Blue 404, Yellow 205, Yellow 401, and Yellow 405. Furthermore, to achieve white, pearlescent, metallic (luster), and shiny effects, materials such as mica titanium, titanium oxide, iron oxide, tin oxide, zirconium oxide, chromium oxide, bismuth oxychloride, silicon dioxide, chromium, titanium nitride, titanium, magnesium fluoride, gold, silver, and nickel can also be used. Optically coherent particles refer to particles that enhance color effects through light reflection, scattering, etc. Examples include glass beads, tiny seashells, and mica. These optional additives are preferably added to the resin composition in the range of 0.0001 to 10.0% by mass, as needed.

[0083] Furthermore, depending on the requirements, rust inhibitors, antioxidants, dispersants, UV absorbers, defoamers, or leveling agents can be added.

[0084] The viscosity of the resin composition of the present invention can be set arbitrarily according to the desired application, but is preferably in the range of 1 to 20,000 mPa·s, more preferably in the range of 5 to 10,000 mPa·s. It should be noted that when the resin composition of the present invention is used as an electrolyte, its viscosity is preferably in the range of 1 to 10,000 mPa·s, more preferably in the range of 10 to 5,000 mPa·s.

[0085] As a method for measuring viscosity, it can be measured using, for example, an A&D vibratory viscometer (CJV5000) manufactured by A&D Corporation at a measurement temperature of 25°C.

[0086] The coating thickness of the resin composition of the present invention after coating and drying is preferably in the range of 1 to 200 μm, more preferably in the range of 5 to 120 μm, and particularly preferably in the range of 10 to 60 μm. Setting the coating thickness to 1 μm or more ensures the surface protective strength of the coating, and setting the coating thickness to 200 μm or less suppresses peeling caused by coating shrinkage, thus this is preferred.

[0087] Electrolyte

[0088] When the resin composition of the present invention is used as an electrolyte, it is preferable to add 0.1 to 30% by mass of a Li salt. The Li salt is a lithium salt soluble in carbonate-based organic solvents, specifically including LiPF6, C2F6LiNO4, LiClO4, LiBF4, LiCoO2, LiBOB, LiBH4, Li(FSO2)2N, Li(CF3SO2)2N, etc. Preferably, the Li salt includes at least one of LiPF6 and C2F6LiNO4. Additionally, small amounts of stabilizers, overcharge inhibitors, flame retardants, etc., for stabilizing the electrode surface may also be added.

[0089] [Polymer Gel Electrolyte]

[0090] By concentrating the electrolyte of the present invention and partially forming a gel, a polymeric gel electrolyte can be obtained. There are no particular limitations on the method for concentrating the electrolyte; examples include methods such as removing some solvent by air drying or forming a highly viscous liquid with surface curing.

[0091] The polymeric gel electrolyte of the present invention preferably has a conductivity of 1 to 30,000 S / cm at 20°C, more preferably 10 to 20,000 μS / cm, and particularly preferably 100 to 10,000 μS / cm.

[0092] The polymeric gel electrolyte of the present invention can be preferably used as a material for Li-ion polymer batteries, double-layer capacitors, electrolytic capacitors, etc.

[0093] Example

[0094] The following examples and comparative examples illustrate the invention in detail, but the invention is not limited to these examples.

[0095] (Example 1)

[0096] 102.4 g (0.4 mol) of 2,2-bis(4-hydroxy-3-methylphenyl)propane (hereinafter referred to as "BPC", manufactured by Honshu Chemical Industry Co., Ltd.) and 0.1 g of dithionite were dissolved in 1100 ml of 5 w / w% sodium hydroxide aqueous solution.

[0097] Add 500ml of dichloromethane, and while stirring, add 0.5g of benzyltriethylammonium chloride (hereinafter referred to as "TEBAC"). Then, while maintaining the temperature at 15°C, blow in 60g of phosgene for 60 minutes.

[0098] After phosgene blowing, 1.5g of p-tert-butylphenol (hereinafter referred to as "PTBP", manufactured by Dai Nippon Ink Chemical Industry Co., Ltd.) as a molecular weight regulator was added and the mixture was stirred vigorously to emulsify the reaction solution. After emulsification, 0.4ml of triethylamine was added and the mixture was stirred at 20-25°C for about 1 hour to complete the polymerization.

[0099] After polymerization, the reaction solution was separated into an aqueous phase and an organic phase. The organic phase was neutralized with phosphoric acid and repeatedly washed with water until the conductivity of the washing solution (aqueous phase) reached below 10 μS / cm. The resulting polymer solution was added dropwise to warm water maintained at 45°C, and the solvent was evaporated to obtain a white powdery precipitate. The precipitate was filtered and dried at 105°C for 24 hours to obtain polymer powder.

[0100] After analyzing the obtained polymer using infrared absorption spectroscopy, a value of 1770 cm⁻¹ was observed. －1 Absorption caused by the carbonyl group at a location near 1240 cm⁻¹ －1 The absorption at nearby sites caused by ether bonds was confirmed to be a polycarbonate resin with carbonate bonds (hereinafter referred to as "PC-1").

[0101] The intrinsic viscosity of the obtained polycarbonate resin was measured using the method described later. Furthermore, as described later, resin compositions containing the obtained polycarbonate resin and various carbonate-based organic solvents were prepared, and solvent solubility tests and film thickness measurements were performed on each composition. Electrolytes A and B, described later, were also prepared using the obtained polycarbonate resin, and the conductivity of each electrolyte was measured. The results are shown in Table 1.

[0102] Intrinsic viscosity (η) of polycarbonate resin

[0103] The specific viscosity of a 0.5 g / dL polycarbonate resin dichloromethane solution at 25 °C was measured using an Ubbelohde capillary viscometer. The Huggins coefficient was 0.45. The intrinsic viscosity was calculated using the following formula (I).

[0104] The measurement conditions are as follows:

[0105] Measuring equipment: Ubbelohde capillary viscometer

[0106] Solvent: dichloromethane

[0107] Resin solution concentration: 0.5 g / dL (=C)

[0108] Temperature measured: 25℃

[0109] Specific viscosity: η sp

[0110] The intrinsic viscosity [η]dL / g was obtained under the condition that the Huggins constant is 0.45(k').

[0111] η sp / C=[η]+k'[η] 2 C(I)

[0112] <Solvent Solubility Test>

[0113] The obtained polycarbonate resins were added to various carbonate-based organic solvents (dimethyl carbonate (DMC), diethyl carbonate (DEC), and methyl ethyl carbonate (MEC)) to prepare resin compositions with concentrations of 1%, 10%, and 20% by mass. These compositions were then placed in sealed glass containers and vibrated on a vibrating sieve for 24 hours. The presence of dissolved residues was visually confirmed. The judgment criteria are as follows:

[0114] A: Completely dissolves at 20% by mass.

[0115] B: 10% by mass completely dissolved, but 20% by mass leaves a residue.

[0116] C: 1% by mass completely dissolved, but at 10% by mass, a dissolution residue was formed.

[0117] D: 0.05% by mass completely dissolved, but 1% by mass produced a dissolution residue.

[0118] Dissolution residue is formed at E: 0.05% by mass.

[0119] Coating performance

[0120] The obtained polycarbonate resin was added to dimethyl carbonate (DMC) to prepare a resin composition with a concentration of 10% by mass, and a coating film was formed using a 200 μm slit coater (only Example 7 used a 400 μm slit coater). After air drying for 1 day, the coating film was dried at 120°C for 1 hour, and the film thickness was measured.

[0121] <Conductivity Measurement>

[0122] A 0.5 mol / L dimethyl carbonate (DMC) solution was prepared using commercially available C2F6LiNO4 (manufactured by Fujifilm and Wako Pure Chemical Industries Co., Ltd.), as solution A. Five parts by weight of polycarbonate resin and 85 parts by weight of DMC were dissolved in a sealed container. Ten parts by weight of solution A were then added while stirring to obtain electrolyte A.

[0123] A commercially available solution containing 1.0 mol / L LiPF6 (EC:DEC = 1:1, volume ratio) (LBG-96533 electrolytic solution (1 mol / L LiPF6, EC:DEC = 1:1 v / v%) manufactured by Kishida Chemical Co., Ltd.) was used as solution B. It should be noted that EC represents ethylene carbonate. Five parts by mass of polycarbonate resin and 90 parts by mass of DMC were dissolved in a sealed container, and five parts by mass of the above solution B were added while stirring to obtain electrolyte B. The conductivity of the resulting electrolytes A and B was measured.

[0124] Measuring device: Conductivity meter (AS ONE Corporation waterproof conductivity meter AS650)

[0125] (Example 2)

[0126] Except for changing BPC to 60.4g, PTBP to 1.8g, and using 40.1g of 2,2-bis(4-hydroxyphenyl)propane (hereinafter referred to as "BPA", manufactured by Mitsubishi Chemical Corporation of Japan), the polymerization was carried out in the same manner as in Example 1 to obtain polycarbonate resin (hereinafter referred to as "PC-2").

[0127] The intrinsic viscosity of the obtained polycarbonate resin was measured in the same manner as in Example 1. Furthermore, using the obtained polycarbonate resin, resin compositions and electrolytes were prepared in the same manner as in Example 1, and solvent solubility tests, film thickness, and conductivity measurements were performed. The results are shown in Table 1.

[0128] (Example 3)

[0129] Except for replacing BPC with 54g of 2,2-bis(4-hydroxyphenyl)-4-methylpentane (hereinafter referred to as "MIBK", manufactured by Honshu Chemical Industry Co., Ltd.) and 58g of 1,1-bis(4-hydroxyphenyl)-1-phenylethane (hereinafter referred to as "BPAP", manufactured by Honshu Chemical Industry Co., Ltd.), changing PTBP to 2.0g, and omitting TEBAC, polymerization was carried out in the same manner as in Example 1 to obtain polycarbonate resin (hereinafter referred to as "PC-3").

[0130] The intrinsic viscosity of the obtained polycarbonate resin was measured in the same manner as in Example 1. Furthermore, using the obtained polycarbonate resin, resin compositions and electrolytes were prepared in the same manner as in Example 1, and solvent solubility tests, film thickness, and conductivity measurements were performed. The results are shown in Table 1. It should be noted that the conductivity measurements were discontinued because polycarbonate resin precipitated in electrolytes A and B.

[0131] (Example 4)

[0132] Except that BPC was replaced with 108g of MIBK, PTBP was replaced with 4.3g of 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole (hereinafter referred to as "BTAZ", manufactured by Otsuka Chemical Co., Ltd.), and TEBAC was not used, polymerization was carried out in the same manner as in Example 1 to obtain polycarbonate resin (hereinafter referred to as "PC-4").

[0133] The intrinsic viscosity of the obtained polycarbonate resin was measured in the same manner as in Example 1. Furthermore, using the obtained polycarbonate resin, resin compositions and electrolytes were prepared in the same manner as in Example 1, and solvent solubility tests, film thickness, and conductivity measurements were performed. The results are shown in Table 1.

[0134] (Example 5)

[0135] Except for replacing BPC with 36.0g and 50.2g of bis(4-hydroxyphenyl)methane (hereinafter referred to as "BPF", manufactured by Sanko Co., Ltd.), changing PTBP to 0.93g, and omitting TEBAC, polymerization was carried out in the same manner as in Example 1 to obtain polycarbonate resin (hereinafter referred to as "PC-5").

[0136] The intrinsic viscosity of the obtained polycarbonate resin was measured in the same manner as in Example 1. Furthermore, using the obtained polycarbonate resin, resin compositions and electrolytes were prepared in the same manner as in Example 1, and solvent solubility tests, film thickness, and conductivity measurements were performed. The results are shown in Table 1. It should be noted that the conductivity measurements were discontinued because polycarbonate resin precipitated in electrolytes A and B.

[0137] (Example 6)

[0138] Except for changing BPC to 60.4g, using 40.1g of BPA and 1.92g of p-hydroxyphenylethanol (hereinafter referred to as "PHEP", manufactured by Otsuka Chemical Co., Ltd.), and not using PTBP and TEBAC, the polymerization was carried out in the same manner as in Example 1 to obtain polycarbonate resin (hereinafter referred to as "PC-6").

[0139] The intrinsic viscosity of the obtained polycarbonate resin was measured in the same manner as in Example 1. Furthermore, using the obtained polycarbonate resin, resin compositions and electrolytes were prepared in the same manner as in Example 1, and solvent solubility tests, film thickness, and conductivity measurements were performed. The results are shown in Table 1.

[0140] (Example 7)

[0141] Except for replacing BPC with 124.0g of 3,3,5-trimethyl-1,1-bis(4-hydroxyphenyl)cyclohexane (hereinafter referred to as "TMC", manufactured by Sanko Co., Ltd.), changing PTBP to 1.62g, and not using TEBAC, polymerization was carried out in the same manner as in Example 1 to obtain polycarbonate resin (hereinafter referred to as "PC-7").

[0142] The intrinsic viscosity of the obtained polycarbonate resin was measured in the same manner as in Example 1. Furthermore, using the obtained polycarbonate resin, resin compositions and electrolytes were prepared in the same manner as in Example 1, and solvent solubility tests, film thickness, and conductivity measurements were performed. The results are shown in Table 1. It should be noted that the conductivity measurements were discontinued because polycarbonate resin precipitated in electrolytes A and B.

[0143] (Example 8)

[0144] Except that BPC was replaced with 94.1g of BPAF, 27.4g of BPA, 1.10g of PHEP, and PTBP was not used, polymerization was carried out in the same manner as in Example 1 to obtain polycarbonate resin (hereinafter referred to as "PC-8").

[0145] The intrinsic viscosity of the obtained polycarbonate resin was measured in the same manner as in Example 1. Furthermore, using the obtained polycarbonate resin, resin compositions and electrolytes were prepared in the same manner as in Example 1, and solvent solubility tests, film thickness, and conductivity measurements were performed. The results are shown in Table 1.

[0146] (Example 9)

[0147] 2.0 g of PC-1 obtained in Example 1 and 8.0 g of diethyl carbonate (DEC) were added to a 100 ml beaker and dissolved by stirring with a Teflon stir bar. After dissolution, 1.0 ml of the above-mentioned solution B (LBG-96533 electrolyte manufactured by Kishida Chemical Co., Ltd. (1 mol / L LiPF6, EC:DEC = 1:1 v / v%)) was added dropwise while stirring. After mixing with the solution B, stirring was stopped, and the mass was measured (the mass excluding the beaker and stir bar was 11.2 g, before concentration). Then, the beaker was placed in a fume hood for 24 hours to remove some of the solvent by air drying, resulting in a surface-cured high-viscosity liquid. The mass of the solution was 8.1 g (after concentration). The conductivity was measured by inserting a conductivity meter into the polymeric gel electrolyte (containing solvent) that had formed a gel. The results are shown in Table 2.

[0148] In addition, the conductivity was measured as follows.

[0149] Measuring device: Conductivity meter (AS ONE Corporation waterproof conductivity meter AS650)

[0150] (Example 10)

[0151] 2.0 g of PC-8 obtained in Example 8 and 8.0 g of DEC were added to a 100 ml beaker and dissolved by stirring with a Teflon stir bar. After dissolution, 2.5 ml of the above-mentioned solution B was added dropwise while stirring. After mixing with solution B, stirring was stopped, and the mass was measured (the mass excluding the beaker and stir bar was 13.0 g, before concentration). Then, the beaker was placed in a fume hood for 24 hours to remove some of the solvent by air drying, resulting in a surface-cured high-viscosity liquid. The mass of the solution was 7.1 g (after concentration). The conductivity was measured by inserting a conductivity meter into the polymeric gel electrolyte (containing solvent) and measuring the conductivity in the same manner as in Example 9. The results are shown in Table 2.

[0152] (Comparative Example 1)

[0153] Except for replacing BPC with 91.2g of BPA, changing PTBP to 2.00g, and omitting TEBAC, polymerization was carried out in the same manner as in Example 1 to obtain polycarbonate resin (hereinafter referred to as "PC-9").

[0154] The intrinsic viscosity of the obtained polycarbonate resin was measured in the same manner as in Example 1. Furthermore, a resin composition was prepared using the obtained polycarbonate resin in the same manner as in Example 1, and a solvent solubility test was performed. It was originally intended to use the resin composition prepared in the same manner as in Example 1 to form a coating film, but this was unsuccessful. Electrolytes A and B were prepared in the same manner as in Example 1, but the conductivity measurement was discontinued due to the precipitation of polycarbonate resin. The results are shown in Table 1.

[0155] (Comparative Example 2)

[0156] Except for replacing BPC with 107.2g of BPZ, changing PTBP to 2.00g, and not using TEBAC, polymerization was carried out in the same manner as in Example 1 to obtain polycarbonate resin (hereinafter referred to as "PC-10").

[0157] The intrinsic viscosity of the obtained polycarbonate resin was measured in the same manner as in Example 1. Furthermore, a resin composition was prepared using the obtained polycarbonate resin in the same manner as in Example 1, and a solvent solubility test was performed. It was originally intended to use the resin composition prepared in the same manner as in Example 1 to form a coating film, but this was unsuccessful. Electrolytes A and B were prepared in the same manner as in Example 1, but the conductivity measurement was discontinued due to the precipitation of polycarbonate resin. The results are shown in Table 1.

[0158] (Comparative Example 3)

[0159] Except for replacing BPC with 116.0g of BPAP, changing PTBP to 2.00g, and omitting TEBAC, polymerization was carried out in the same manner as in Example 1 to obtain polycarbonate resin (hereinafter referred to as "PC-11").

[0160] The intrinsic viscosity of the obtained polycarbonate resin was measured in the same manner as in Example 1. Furthermore, a resin composition was prepared using the obtained polycarbonate resin in the same manner as in Example 1, and a solvent solubility test was performed. It was originally intended to use the resin composition prepared in the same manner as in Example 1 to form a coating film, but this was unsuccessful. Electrolytes A and B were prepared in the same manner as in Example 1, but the conductivity measurement was discontinued due to the precipitation of polycarbonate resin. The results are shown in Table 1.

[0161] (Comparative Example 4)

[0162] Except for replacing BPC with 14.8g of 4,4'-biphenyl hydroquinone (hereinafter referred to as "BP", manufactured by Honshu Chemical Industry Co., Ltd.) and 73.0g of BPA, changing PTBP to 1.30g, and omitting TEBAC, polymerization was carried out in the same manner as in Example 1 to obtain polycarbonate resin (hereinafter referred to as "PC-12").

[0163] The intrinsic viscosity of the obtained polycarbonate resin was measured in the same manner as in Example 1. Furthermore, a resin composition was prepared using the obtained polycarbonate resin in the same manner as in Example 1, and a solvent solubility test was performed. It was originally intended to use the resin composition prepared in the same manner as in Example 1 to form a coating film, but this was unsuccessful. Electrolytes A and B were prepared in the same manner as in Example 1, but the conductivity measurement was discontinued due to the precipitation of polycarbonate resin. The results are shown in Table 1.

[0164] (Comparative Example 5)

[0165] The composition was prepared in the same manner as in Example 1, except that polycarbonate resin was replaced by dimethyl carbonate (DMC) instead of polycarbonate resin. It was intended to form a coating film using the resulting composition, but this was unsuccessful. Electrolytes A and B were also prepared in the same manner as in Example 1, except that polycarbonate resin was replaced by dimethyl carbonate (DMC) instead of polycarbonate resin, and conductivity measurements were performed. The results are shown in Table 1.

[0166] [Table 1]

[0167]

[0168] [Table 2]

[0169] The composition of solution B after mixing and stopping stirring (before concentration)

[0170]

[0171] Composition and conductivity of the highly viscous liquid after air drying to remove some of the solvent and surface curing (after concentration)

[0172]

[0173]

[0174] Industrial practicality

[0175] The resin composition of the present invention is a resin composition obtained by dissolving polycarbonate resin, which has high solubility in carbonate-based organic solvents. It has low toxicity and is suitable for use as a coating material (paint or ink) for various substrates. Furthermore, it exhibits good compatibility with Li salts and maintains high conductivity even when the polycarbonate resin is dissolved, making it highly effective as an electrolyte. It is particularly effective in modifying the SEI (Solid Electrolyte Interphase) layer of electrolytes in Li-ion batteries and Li-ion polymer batteries, and can impart flame retardancy and other properties to Li-ion batteries and Li-ion polymer batteries. Moreover, since a concentrated solution of the electrolyte of the present invention can form a gel, it can be used as a polymeric gel electrolyte for Li-ion polymer batteries.

Claims

1. A resin composition, characterized in that, Include, Polycarbonate resin and carbonate-based organic solvents The content of the polycarbonate resin in the resin composition is 0.05% to 50% by mass. The content of the carbonate-based organic solvent in the resin composition is 50-99.5% by mass. In the polycarbonate resin, the total proportion of the structural units represented by the following formula (2) or (3) is 0-75% in molar ratio. ， The polycarbonate resin contains structural units comprising one or more structural units selected from those shown in formula (6) or (8) below. 。 2. The resin composition according to claim 1, characterized in that, The content of carbonate-based organic solvent in the resin composition is 70-99% by mass.

3. The resin composition according to claim 1, characterized in that, The carbonate-based organic solvent includes at least one selected from dimethyl carbonate, diethyl carbonate, and methyl ethyl carbonate.

4. The resin composition according to claim 3, characterized in that, The carbonate-based organic solvent also contains ethylene carbonate.

5. The resin composition according to claim 1, characterized in that, The polycarbonate resin has an intrinsic viscosity of 0.3 to 2.0 dl / g.

6. The resin composition according to claim 1, characterized in that, The resin composition does not contain any organic solvents other than the carbonate-based organic solvents.

7. A coating film, characterized in that, The coating is formed by drying the resin composition according to any one of claims 1 to 6.

8. An electrolyte, characterized in that, The electrolyte is an electrolyte in which 0.1 to 30% by mass of lithium salt is dissolved in the resin composition according to any one of claims 1 to 6.

9. The electrolyte as described in claim 8, characterized in that, The lithium salt comprises at least one of LiPF6 and C2F6LiNO4.

10. A polymeric gel electrolyte, characterized in that, The polymeric gel electrolyte is an electrolyte obtained by gelling the electrolyte according to claim 8.

11. The polymeric gel electrolyte as described in claim 10, characterized in that, The conductivity of the polymeric gel electrolyte is 1–30,000 μS / cm.

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