Phenoxy resin

Abstract

The objective is to provide a resin with excellent thermal conductivity, solvent solubility, and heat resistance. [Solution] A phenoxy resin is provided obtained by reacting a compound represented by the following general formula (1) with a compound represented by the following general formula (2). TIFF2026098331000012.tif43140 TIFF2026098331000013.tif3096

Description

Technical Field

[0001] The present invention relates to a novel phenoxy resin.

Background Art

[0002] In recent years, with the miniaturization and high performance of electronic devices, heat dissipation countermeasures for electronic devices have become an issue, and the development of various thermally conductive materials has been progressing. The thermally conductive materials to be developed can be roughly divided into fillers to be filled and resins. As fillers, alumina and magnesium oxide are known, and as resins, biphenyl-type epoxy resins and phenoxy resins are known.

[0003] Patent Document 1 discloses a sealing resin composition containing an epoxy resin and an inorganic filler. Using a transfer molding machine, a molded product with a width of 4 mm × thickness of 3 mm × length of 15 mm is molded at a mold temperature of 175°C, an injection pressure of 7.4 MPa, and a curing time of 2 minutes, and post-cured at 175°C for 4 hours. A sealing resin composition is disclosed in which the glass transition temperature measured by thermomechanical analysis of the cured product is 140°C or higher and 270°C or lower, and the flexural modulus of elasticity E260 at 260°C of the cured product is 0.1 GPa or higher and 5 GPa or lower. It is described that the epoxy resin is a biphenyl-type epoxy resin represented by the general formula (1).

[0004] Patent Document 2 discloses a phenoxy resin containing a specific repeating unit. It is described that it has a specific structure having a novel structure (mesogen structure) with an ester bond between two benzene rings.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

[0006] However, although the resin composition described in Patent Document 1 has been shown to have excellent crack resistance through evaluation, there is no mention of its thermal conductivity, and further investigation is needed. In addition, the phenoxy resin described in Patent Document 2 has low solvent solubility, which affects its processability.

[0007] Therefore, the object of the present invention is to provide a resin with excellent thermal conductivity, solvent solubility, and heat resistance. [Means for solving the problem]

[0008] The inventors have found that the above problems can be solved by using a novel phenoxy resin having a specific structure.

[0009] (1) A phenoxy resin obtained by reacting a compound represented by the following general formula (1) with a compound represented by the following general formula (2).

[0010] [ka] (In the formula, R1 independently represents either a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms.)

[0011] [ka] (In the formula, Y represents a carbonyl group or a carboxyl group, Z represents a hydrocarbon group having 1 to 6 carbon atoms, and R2 independently represents one of a hydrogen atom, a methyl group, or a methoxy group.) (2) The phenoxy resin according to (1) above, wherein the general formula (2) is a compound represented by the following general formula (3).

[0012] [Chemical formula] (3) The phenoxy resin according to (1) or (2) above, wherein R1 in the general formula (1) is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. (4) The phenoxy resin according to any one of (1) to (3) above, having a weight average molecular weight of 2,000 to 30,000 (5) The phenoxy resin according to any one of (1) to (4) above, having an epoxy equivalent of 300 g / eq to 6,000 g / eq. (6) A resin composition containing the phenoxy resin according to any one of (1) to (5) above. [Advantages of the Invention]

[0013] (3) According to the present invention, it is possible to provide a novel phenoxy resin having high thermal conductivity, high solvent solubility and high heat resistance. [Modes for Carrying Out the Invention]

[0014] Hereinafter, embodiments of the present invention will be described in detail.

[0015] [Phenoxy Resin] The phenoxy resin of the present invention has a structure formed by reacting a compound represented by the following general formula (1) and a compound represented by the following general formula (2).

[0016] [Chemical formula]

[0017] In the general formula (1), each R1 independently represents a hydrogen atom or any one of hydrocarbon groups having 1 to 10 carbon atoms.

[0018] [Chemical formula]

[0019] In general formula (2), Y represents a carbonyl group or a carboxyl group, Z represents a hydrocarbon group having 1 to 6 carbon atoms, and R2 independently represents a hydrogen atom, a methyl group, or a methoxy group.

[0020] The hydrocarbon group having 1 to 10 carbon atoms in general formula (1) is not particularly limited, but examples include alkyl groups having 1 to 10 carbon atoms. Among these, alkyl groups having 1 to 4 carbon atoms are preferred, and methyl groups are particularly preferred. The substituents are preferred from the viewpoint of heat resistance and discoloration resistance.

[0021] The hydrocarbon group having 1 to 6 carbon atoms in general formula (2) is not particularly limited, but examples include alkyl groups having 1 to 6 carbon atoms and alicyclic groups having 3 to 6 carbon atoms. Among these, alkyl groups or cyclohexyl groups having 1 to 3 carbon atoms are preferred, and ethyl groups and cyclohexyl groups are particularly preferred. Furthermore, the hydrocarbon group may have some of its hydrogen atoms replaced by hydroxyl groups. The number of hydroxyl groups is not particularly limited, but it is preferably 0 or 1.

[0022] The aforementioned general formula (2) is not particularly limited, but from the viewpoint of the solvent solubility of the resulting phenoxy resin, it is more preferably a compound represented by the following general formula (3).

[0023] [ka]

[0024] The weight-average molecular weight (Mw) of the phenoxy resin of the present invention is preferably 2,000 to 30,000, more preferably 2,000 to 20,000, and even more preferably 2,000 to 10,000. Mw is measured by gel permeation chromatography (GPC) and the value is shown converted using a standard polystyrene calibration curve. By keeping the Mw within the above range, the thermal conductivity and solvent solubility of the phenoxy resin can be improved.

[0025] The epoxy equivalent of the phenoxy resin of the present invention is preferably 300 g / eq to 6,000 g / eq, more preferably 350 g / eq to 5,000 g / eq, and particularly preferably 400 g / eq to 4,500 g / eq. Being within this range is preferable because it improves the thermal conductivity and solvent solubility of the phenoxy resin in the resulting resin composition.

[0026] The melt viscosity of the phenoxy resin in this embodiment is not particularly limited, but for example, the melt viscosity at 180°C is preferably 50 mPa·s or less, and more preferably 30 mPa·s or less. Within this range, excellent moldability can be achieved.

[0027] [Method for producing phenoxy resin] The phenoxy resin of the present invention can be synthesized by reacting a compound represented by the above general formula (1) with a compound represented by the above general formula (2).

[0028] <Compounds of general formula (1)> Examples of compounds represented by the above general formula (1) include 4,4'-bis(glycidyloxy)-1,1'-biphenyl, tetramethyl-4,4'-bis(glycidyloxy)-1,1'-biphenyl, tetraethyl-4,4'-bis(glycidyloxy)-1,1'-biphenyl, and tetrabutyl-4,4'-bis(glycidyloxy)-1,1'-biphenyl. Among these, 4,4'-bis(glycidyloxy)-1,1'-biphenyl and tetramethyl-4,4'-bis(glycidyloxy)-1,1'-biphenyl are more preferred from the viewpoint of maintaining molecular orientation and improving thermal conductivity.

[0029] <Compounds of general formula (2)> Examples of compounds represented by the above general formula (2) include esterified compounds of hydroxybenzoic acid and 4-(4-hydroxycyclohexyl)phenol, compounds obtained by reacting at least one selected from the group consisting of 2-hydroxybenzaldehyde, 3-hydroxybenzaldehyde, and 4-hydroxybenzaldehyde with one of 2-hydroxyacetophenone, 3-hydroxyacetophenone, 4-hydroxyacetophenone, 4'-hydroxy-2'-methylacetophenone, 4'-hydroxy-3'-methylacetophenone, 2'-hydroxy-5'-methylacetophenone, 4'-hydroxy-3'-methoxyacetophenone, and 2'-hydroxy-4'-methoxyacetophenone.

[0030] The reaction between the compound represented by general formula (1) and the compound represented by general formula (2) can be carried out using the compound and a reaction catalyst, either in the absence of a solvent or in the presence of a solvent.

[0031] <Reaction catalyst> The reaction catalyst is not particularly limited as long as it is a compound that has catalytic activity to promote the etherification reaction between an epoxy group and a phenolic hydroxyl group. Examples include alkali metal compounds, organophosphorus compounds, tertiary amines, quaternary ammonium salts, cyclic amines, imidazoles, and the like.

[0032] Specific examples of the alkali metal compounds include, for example, alkali metal hydroxides such as sodium hydroxide, lithium hydroxide, and potassium hydroxide; alkali metal salts such as sodium carbonate, sodium bicarbonate, sodium chloride, lithium chloride, and potassium chloride; alkali metal alkoxides such as sodium methoxide and sodium ethoxide; and alkali metal salts of organic acids such as alkali metal phenoxide, sodium hydride, lithium hydride, sodium acetate, and sodium stearate.

[0033] Specific examples of the aforementioned organophosphorus compounds include, for example, chain phosphines such as tri-n-propylphosphine, tri-n-butylphosphine, tricyclohexylphosphine, triphenylphosphine, and diphenylmethylphosphine; cyclic phosphines such as paramethylphosphine; bisphosphines such as 1,2-bis(dimethylphosphine)ethane and 1,4-bis(diphenylphosphine)butane; tetramethylphosphonium bromide, tetramethylphosphonium iodide, tetramethylphosphonium hydroxide, trimethylcyclohexylphosphonium chloride, trimethylcyclohexylphosphonium bromide, trimethylbenzylphosphonium chloride, trimethylbenzylphosphonium bromide, tetraphenylphosphonium bromide, triphenylmethylphosphonium iodide, triphenylethylphosphonium chloride, triphenylethylphosphonium bromide, triphenylethylphosphonium iodide, triphenylbenzylphosphonium chloride, and triphenylbenzylphosphonium bromide.

[0034] Specific examples of the aforementioned tertiary amines include triethylamine, tri-n-propylamine, tri-n-butylamine, triethanolamine, and benzyldimethylamine. Specific examples of quaternary ammonium salts include tetramethylammonium chloride, tetramethylammonium bromide, tetramethylammonium hydroxide, triethylmethylammonium chloride, tetraethylammonium chloride, tetraethylammonium bromide, tetraethylammonium iodide, tetrapropylammonium bromide, tetrapropylammonium hydroxide, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylammonium hydroxide, benzyltributylammonium chloride, and phenyltrimethylammonium chloride.

[0035] Examples of the quaternary ammonium salts include tetramethylammonium hydroxide, benzyltributylammonium chloride, and tetrabutylammonium chloride.

[0036] Examples of the aforementioned cyclic amines include, for example, 1,8-diazabicyclo(5,4,0)undecene-7 and 1,5-diazabicyclo(4,3,0)nonene-5.

[0037] Specific examples of the imidazoles mentioned above include, for example, 2-methylimidazole, 2-ethyl-4-methylimidazole, and 2-phenylimidazole.

[0038] These catalysts can be used in combination. Typically, the amount of catalyst used is preferably 0.001 to 3% by mass, more preferably 0.1 to 2% by mass, and particularly preferably 0.5 to 1% by mass, relative to the reaction solids.

[0039] Among them, chain-like phosphines such as triphenylphosphine and tributylphosphine are Triphenylphosphine is preferred in terms of ease of synthesis and storage stability.

[0040] <Solvent> In the present invention, when a solvent is used in the synthesis reaction during manufacturing, it is not particularly limited as long as it dissolves the phenoxy resin, and examples include amide solvents, ketone solvents, glycol solvents, aromatic solvents, ester solvents, and other polar solvents.

[0041] Examples of the aforementioned amide solvents include formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N,N,N',N'-tetramethylurea, 2-pyrrolidone, N-methylpyrrolidone, and carbamitic acid esters.

[0042] Examples of the ketone solvents include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, acetylacetone, diisobutyl ketone, isophorone, methylcyclohexanone, and acetophenone.

[0043] Examples of the glycol-based solvents include: ethylene glycol dialkyl ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and ethylene glycol dibutyl ether; polyethylene glycol dialkyl ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, and triethylene glycol dibutyl ether; ethylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, and ethylene glycol monobutyl ether acetate; diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, and triethylene glycol monomethyl ether acetate. Polyethylene glycol monoalkyl ether acetates such as triethylene glycol monoethyl ether acetate, triethylene glycol monobutyl ether acetate; propylene glycol dialkyl ethers such as propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dibutyl ether; polypropylene glycol dialkyl ethers such as dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol dibutyl ether, tripropylene glycol dimethyl ether, tripropylene glycol diethyl ether, tripropylene glycol dibutyl ether; propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate;Examples include polypropylene glycol monoalkyl ether acetates such as dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene glycol monobutyl ether acetate, tripropylene glycol monomethyl ether acetate, tripropylene glycol monoethyl ether acetate, and tripropylene glycol monobutyl ether acetate; dialkyl ethers of copolymerized polyether glycols such as low molecular weight ethylene-propylene copolymers; monoacetate monoalkyl ethers of copolymerized polyether glycols; alkyl esters of copolymerized polyether glycols; and monoalkyl ester monoalkyl ethers of copolymerized polyether glycols.

[0044] Examples of the aromatic solvents include benzene, toluene, xylene, as well as Solvesso 100 (manufactured by Kyoei Solvent Co., Ltd.) and Solvesso 150 (manufactured by Kyoei Solvent Co., Ltd.).

[0045] Examples of the ester solvent include ethyl acetate, n-propyl acetate, isopropyl acetate, and n-butyl acetate.

[0046] Other polar solvents mentioned above include dimethyl sulfoxide, sulfolane, and γ-butyrolactone.

[0047] <Synthesis conditions> The reaction temperature of the phenoxy resin should be within a temperature range that does not cause the reaction catalyst to decompose. The reaction temperature can be appropriately selected from the viewpoint of achieving the desired molecular weight and suppressing side reactions. For example, 50 to 300°C is preferred, 100 to 250°C is more preferred, and 120 to 200°C is particularly preferred. From the viewpoint of reaction rate, 120°C or higher is suitable, and from the viewpoint of suppressing side reactions, 200°C or higher is suitable. When using a low-boiling point solvent, the reaction temperature can also be ensured by carrying out the reaction under high pressure using an autoclave.

[0048] The reaction time is not particularly limited and can be selected as appropriate from the standpoint of achieving the desired molecular weight or suppressing side reactions, but for example, 2 to 10 hours is preferable.

[0049] Furthermore, the phenoxy resin of the present invention can also be synthesized by reacting a compound represented by the following general formula (4) with a compound represented by the following general formula (5).

[0050] [ka]

[0051] In general formula (4), Y represents a carbonyl group or a carboxyl group, Z represents a hydrocarbon group having 1 to 6 carbon atoms, and R2 independently represents one of a hydrogen atom, a methyl group, or a methoxy group.

[0052] [ka]

[0053] In general formula (5), R1 independently represents either a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms.

[0054] <Compounds of general formula (4)> Examples of compounds represented by the above general formula (4) include epoxidized compounds of the compounds represented by the aforementioned general formula (2).

[0055] <Compounds of general formula (5)> Examples of compounds represented by the above general formula (5) include biphenol, tetramethylbiphenol, tetraethylbiphenol, and tetrabutylbiphenol. Among these, biphenol and tetramethylbiphenol are more preferred from the viewpoint of maintaining molecular orientation and improving thermal conductivity.

[0056] [Resin composition] The resin composition of the present invention preferably contains the phenoxy resin. The inclusion of the phenoxy resin is preferable because it improves the handling properties of the resin composition due to the excellent solvent solubility of the phenoxy resin, and also because it results in excellent thermal conductivity and heat resistance when used as a resin sheet or metal base substrate.

[0057] It is more preferable that the phenoxy resin is present in an amount of 0.3% to 30% by mass relative to the non-volatile content (100% by mass) of the resin composition that does not contain the filler described later.

[0058] The resin composition may contain a thermally conductive filler. The thermally conductive filler may include, for example, at least one selected from alumina, aluminum nitride, boron nitride, silicon nitride, silicon carbide, and magnesium oxide. These may be used individually or in combination of two or more.

[0059] The resin composition may also contain a silane coupling agent. This can improve the compatibility of the thermally conductive filler in the resin composition. The coupling agent may be added to the resin composition or used by treating the surface of the thermally conductive filler.

[0060] The resin composition may contain other components besides those described above. Examples of these other components include antioxidants and leveling agents.

[0061] The resin composition may contain low molecular weight components generated during the production of phenoxy resin. These low molecular weight components are components with a weight-average molecular weight Mw of 1,000 or less, and include unreacted compounds represented by the above general formulas (1) and (2), or reactants thereof, with a weight-average molecular weight below the aforementioned range.

[0062] The lower the content of the low molecular weight component, the better the thermal conductivity of the resulting resin sheet or metal-based substrate. On the other hand, from the viewpoint of the fluidity of the resulting resin composition, a certain amount may be included.

[0063] The content of the low molecular weight component is preferably 1% by mass or more and 70% by mass or less, more preferably 2% by mass or more and 50% by mass or less, and particularly preferably 3% by mass or more and 45% by mass or less, relative to the non-volatile content (100% by mass) of the resin composition that does not contain inorganic fillers.

[0064] 〔varnish〕 The resin composition of the present invention is suitably used in varnishes. Known methods can be used to prepare the varnish; the resin composition can be dissolved (diluted) in an organic solvent to produce the varnish.

[0065] As the solvent, for example, polar solvents such as methyl ethyl ketone, methoxypropanol, N,N-dimethylformamide, and dimethyl sulfoxide can be used, and one solvent may be used alone, or two or more may be used in combination.

[0066] The amount of solvent used is not particularly limited and can be appropriately determined, for example, taking into account sheet processability. Specifically, it is preferable to prepare the resulting varnish so that its viscosity is between 3000 mPa·s and 15000 mPa·s. A viscosity of 3000 mPa·s or higher is preferable because it suppresses appearance defects due to repulsion during coating. A viscosity of 15000 mPa·s or lower is preferable because it suppresses appearance defects due to streaking during coating.

[0067] [Resin sheet] The aforementioned varnish is suitably used for resin sheets. The resin sheet is obtained by applying the above-mentioned varnish to a carrier material and then heating and drying it. Furthermore, the resin sheet is formed in a semi-cured state on the surface of the carrier material. In other words, the heat drying process is a B-stage process, in which the phenoxy resin in the varnish is partially reacted by heating the varnish applied to the carrier material. Therefore, the resin sheet of this embodiment has the property of melting once due to the heat and pressure of lamination molding and then curing.

[0068] The method of applying the varnish is not particularly limited and can be carried out by known methods. Examples include comma coating, die coating, lip coating, and gravure coating. Preferred methods for forming an inorganic composite sheet of a predetermined thickness include the comma coating method, in which the object to be coated is passed through gaps, and the die coating method, in which varnish is applied from a nozzle with a controlled flow rate.

[0069] The thickness of the resin sheet formed on the carrier material is preferably 35 μm to 100 μm, more preferably 40 μm to 90 μm, and particularly preferably 40 μm to 80 μm. A thickness of 100 μm or less is preferable because it reduces thermal resistance. When a two-layer lamination is used, a thickness of 60 μm or less for the resin sheet results in particularly excellent thermal conductivity and insulation reliability of the resulting molded product.

[0070] It is preferable to use a polymer film or a metal sheet as the carrier material. Examples of polymer films include polyolefins such as polyethylene, polypropylene, and polyvinyl chloride, polyesters such as polyethylene terephthalate, polycarbonate, acetylcellulose, and tetrafluoroethylene. Examples of metal sheets include copper foil, aluminum foil, and nickel foil. Furthermore, release paper can be used as a carrier material.

[0071] [Metal-based substrate] The resin sheet of the present invention can be suitably used as a metal base substrate after lamination molding. Specifically, two or more of the resin sheets obtained above are laminated to a desired thickness, and then a metal foil is placed on the outermost layer of one or both sides to form a laminate. This laminate is then integrated by heating and pressing, such as in press molding. Here, as the metal foil, single, alloy, or composite metal foils of copper, aluminum, brass, nickel, etc. can be used. The conditions for heating and pressing the laminate can be appropriately adjusted to the conditions under which the varnish of the present invention hardens. However, if the pressure is too low, air bubbles may remain inside the resulting metal base substrate, which may reduce its electrical properties. Therefore, it is preferable to pressurize under conditions that satisfy moldability. For example, a metal base substrate can be obtained by integral molding by heating and pressing for 10 minutes to 2 hours under conditions of a heating temperature of 100 to 200°C and a pressure of 0.98 to 4.9 MPa.

[0072] [Application] The phenoxy resin of the present invention possesses thermal conductivity, solvent solubility, and heat resistance, and resin sheets and metal base substrates containing them can be suitably used in printed circuit boards such as heat dissipation substrates for mounting semiconductor wafers, high-brightness LEDs, power semiconductor devices, and the like. [Examples]

[0073] Next, the present invention will be specifically described with reference to examples and comparative examples. In the following, "parts" and "%" refer to mass unless otherwise specified. Phenoxy resin, resin sheets obtained using the phenoxy resin, and metal base substrates were prepared under the conditions shown below, and measured or calculated and evaluated under the conditions shown below.

[0074] <Heat resistance> For the obtained resin, using a DSC device (Pyris Diamond) manufactured by PerkinElmer, after measuring the exothermic peak temperature (thermosetting temperature) observed when measuring under heating conditions of 20 °C / min from room temperature, it was held at a temperature 50 °C higher than that for 30 minutes. Then, the sample was cooled to room temperature under cooling conditions of 20 °C / min, and further heated under heating conditions of 20 °C / min again to measure the glass transition temperature (Tg) (°C) of the resin film (cured product). Note that as the glass transition temperature (Tg), if it is 170 °C or higher, there is no practical problem, and preferably it is 180 °C or higher.

[0075] <Solvent solubility> Into a sample bottle, 8 parts of each of the resins of the examples and comparative examples and methyl ethyl ketone were added to make the solution concentration 20%, and then stirred with a shaker under normal temperature conditions. After stirring, the state of the solvent in the sample bottle was visually evaluated. The evaluation was "○" for a uniform and transparent state, "△" for a state where some solid components were precipitated, and "×" for a state where solid components were precipitated.

[0076] <Thermal conductivity> · Preparation of resin molded body A mixture obtained by mixing 2 parts of a catalyst (2-methylimidazole) with 100 parts of each of the phenoxy resins of the examples and comparative examples was set in a mold coated with a release agent, and compression molding was carried out at 180 °C for 30 min to obtain a resin molded body with a diameter of 10 mm × thickness of 1 mm. Then, curing was carried out in an oven at 180 °C for 180 min to obtain a resin molded body (sample for measuring thermal conductivity).

[0077] Using the obtained resin molded body, the thermal diffusivity and specific heat at 25 °C were measured using a thermal conductivity measuring device (LFA467 HyperFlash, manufactured by NETZSCH). Then, the density of this resin molded body was measured by the Archimedes method. The thermal conductivity of this resin molded body was estimated from the product of the obtained thermal diffusivity, specific heat, and density.

[0078] <GPC measurement (evaluation of the weight average molecular weight (Mw) of the curable resin)> The following measuring devices and conditions were used to obtain GPC charts for the phenoxy resins obtained in the examples and comparative examples. The weight-average molecular weight (Mw) of the phenoxy resins was calculated from the results of the GPC charts.

[0079] Measuring device: Tosoh Corporation "HLC-8320 GPC" Columns: Tosoh Corporation Guard Column "HXL-L" + Tosoh Corporation "TSK-GEL G2000HXL" + Tosoh Corporation "TSK-GEL G2000HXL" + Tosoh Corporation "TSK-GEL G3000HXL" + Tosoh Corporation "TSK-GEL G4000HXL" Detector: RI (Differential Refractometer) Data processing: Tosoh Corporation's "GPC Workstation EcoSEC-WorkStation" Measurement conditions: Column temperature 40℃ Developing solvent: tetrahydrofuran Flow rate 1.0ml / min Standard: In accordance with the measurement manual for the aforementioned "GPC Workstation EcoSEC-WorkStation," the following monodisperse polystyrenes with known molecular weights were used.

[0080] (Uses polystyrene) "A-500" manufactured by Tosoh Corporation "A-1000" manufactured by Tosoh Corporation "A-2500" manufactured by Tosoh Corporation "A-5000" manufactured by Tosoh Corporation "F-1" manufactured by Tosoh Corporation "F-2" manufactured by Tosoh Corporation "F-4" manufactured by Tosoh Corporation Tosoh Corporation's "F-10" F-20 manufactured by Tosoh Corporation Tosoh Corporation's "F-40" Tosoh Corporation's "F-80" Tosoh Corporation's "F-128" Sample: A tetrahydrofuran solution containing 1.0% by mass (based on solid content) of the phenoxy resin obtained in the examples and comparative examples, filtered through a microfilter (50 μl).

[0081] [Example 1] 11.0 parts of 4-hydroxybenzoic acid, 19.9 parts of 4-(4-hydroxycyclohexyl)phenol, 1.51 parts of p-toluenesulfonic acid, and 220 parts of chlorobenzene were added to a reaction vessel and refluxed for 16 hours. After the resulting mixture was cooled to room temperature, the precipitated solid was filtered. The precipitate was added to a mixed solution of 700 ml of chloroform and 100 ml of ethanol and stirred at 55°C for 1 hour. After the resulting mixture was cooled, the precipitated solid was filtered, washed with chloroform, and dried under reduced pressure for 4 hours to obtain dihydroxy compound 1.

[0082] 14.52 parts of 3,3',5,5'-tetramethyl-4,4'-biphenol, 80 parts of epichlorohydrin, 0.65 parts of benzyltriethylammonium chloride, and 10 parts of isopropanol were added to a reaction vessel and heated and stirred at 90°C for 6 hours. Then, 8 g of 40% sodium hydroxide solution was added dropwise and stirred for 1 hour. After the resulting mixture was cooled to room temperature, it was added to pure water to obtain a precipitate. The obtained precipitate was washed with water and dried to obtain epoxy compound 1.

[0083] The obtained dihydroxy compound 1 and epoxy compound 1 were added to a reactor together with triphenylphosphine (TPP) and cyclohexanone, and melted and mixed at 100°C to 110°C for 1 hour. The mixture was then heated to 150°C, and the reaction was carried out under reduced pressure at this temperature while removing the solvent. The reaction was stopped after confirming that the desired molecular weight was reached by GPC, and phenoxy resin 1 was obtained. The reaction was carried out for 16 hours. After the reaction, 100 parts of cyclohexanone were added to the resin to dissolve it, and the resin was cooled to room temperature. After cooling, the resin was purified by reprecipitation using methanol to obtain phenoxy resin 1. The phenoxy resin 1 had a Tg of 180°C and good solvent solubility. Furthermore, its thermal conductivity was excellent at 0.4.

[0084] [Example 2] Dihydroxy compound 2 was obtained by the same synthesis method as in Example 1, except that 4-hydroxybenzoic acid was replaced with 4-hydroxy-3-methylbenzoic acid. Phenoxy resin 2 was obtained by reacting it with epoxy compound 1 in the same manner as in Example 1. The Tg of the phenoxy resin 2 was 180°C, and its solvent solubility was good. Furthermore, its thermal conductivity was excellent.

[0085] [Example 3] 13.6 parts of 4-hydroxyacetophenone, 15.2 parts of 4-hydroxy-3-methoxybenzaldehyde, and 20 parts of ethanol were added to a reaction vessel and stirred. Then, 2 parts of 97% by mass sulfuric acid were added, and the mixture was reacted at 60°C for 10 hours. The reaction solution was then injected with 120 parts of water and crystallized. The resulting precipitate was washed with water and dried to obtain dihydroxy compound 3. The obtained dihydroxy compound 3 was reacted with epoxy compound 1 in the same manner as in Example 1 to obtain phenoxy resin 3. The Tg of the phenoxy resin 3 was 175°C, and its solvent solubility was good. Furthermore, its thermal conductivity was excellent.

[0086] [Example 4] Dihydroxy compound 4 was obtained by the same synthesis method as in Example 3, except that 4-hydroxyacetophenone was replaced with 16.6 parts of 4-hydroxy-3-methoxyacetophenone and 4-hydroxy-3-methoxybenzaldehyde was replaced with 12.2 parts of 4-hydroxybenzaldehyde. This compound was then reacted with epoxy compound 1 in the same manner as in Example 1 to obtain phenoxy resin 4. The Tg of the phenoxy resin 4 was 170°C, and its solvent solubility was good. Furthermore, its thermal conductivity was excellent.

[0087] [Example 5] Dihydroxy compound 5 was obtained by the same synthesis method as in Example 3, except that 4-hydroxyacetophenone was replaced with 5.6 parts of 4-methylcyclohexanone. This compound was then reacted with epoxy compound 1 in the same manner as in Example 1 to obtain phenoxy resin 5. The Tg of the phenoxy resin 5 was 170°C, and its solvent solubility was good. Furthermore, its thermal conductivity was excellent.

[0088] [Comparative Example 1] As the dihydroxy compound, 4,4'-dihydroxydiphenyl ether was used and reacted with epoxy compound 1 in the same manner as in Example 1 to obtain phenoxy resin 6. The Tg of the phenoxy resin 5 was less than 170°C, and its solvent solubility was △. Furthermore, its thermal conductivity was poor.

Claims

1. A phenoxy resin obtained by reacting a compound represented by the following general formula (1) with a compound represented by the following general formula (2). 【Chemistry 1】 (In the formula, R1 independently represents either a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms.) 【Chemistry 2】 (In the formula, Y represents a carbonyl group or a carboxyl group, Z represents a hydrocarbon group having 1 to 6 carbon atoms, and R2 independently represents one of a hydrogen atom, a methyl group, or a methoxy group.)

2. The phenoxy resin according to claim 1, wherein the general formula (2) is a compound represented by the following general formula (3). 【Transformation 3】

3. The phenoxy resin according to claim 1 or 2, wherein R1 in the general formula (1) is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

4. The phenoxy resin according to claim 1 or 2, wherein the weight-average molecular weight is 2,000 to 30,000.

5. The phenoxy resin according to claim 1 or 2, wherein the epoxy equivalent is 300 g / eq to 6,000 g / eq.

6. A resin composition comprising the phenoxy resin according to claim 1 or 2.

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