Novel diol compounds with an isocyanurate skeleton

Abstract

To solve the problem in which introducing isocyanurate skeletons into resin systems, such as polyester, polyurethane, polycarbonate, polymerized from diol monomers, is desired for the expression of characteristics such as heat resistance, mechanical strength, moisture resistance, and electrical properties, but there are only a limited number of reports of isocyanurate compounds with hydroxy groups, and to provide novel diol compounds with isocyanurate skeletons.SOLUTION: The foregoing problem is solved by a compound represented by the following formula (1) (where R is a hydrogen atom or a monovalent organic group).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a novel diol compound having an isocyanurate skeleton. [Background technology]

[0002] Isocyanurate compounds have traditionally been used as resin modifiers and crosslinking agents in the field of resin materials. Because they have a rigid, highly stacking central skeleton, their incorporation into resin materials can impart unprecedented physical properties, such as improved mechanical strength, heat resistance, moisture resistance, and hydrolysis resistance. Patent Document 1 demonstrates that combining polyphenylene ether with an isocyanurate crosslinking agent exhibits excellent electrical properties. Patent Document 2 discloses an isocyanurate compound having a glycidyl group, which, when combined with an epoxy resin, can impart excellent heat resistance and mechanical properties. Furthermore, in addition to being used as a crosslinking agent or resin modifier, examples have also been reported in which an isocyanurate skeleton is directly introduced into the main skeleton of a resin as a monomer. The diamine compound having an isocyanurate skeleton described in Patent Document 3 can be used as a raw material (monomer) for polyimide resins. Direct introduction of an isocyanurate skeleton into the polyimide skeleton is expected to reveal unprecedented physical properties. Furthermore, this diamine compound can also be used as a curing agent for epoxy resins.

[0003] Patent Document 4 also describes a diamine monomer having an isocyanurate skeleton, shows the use of a polyimide obtained using the monomer as a liquid crystal aligning agent, and discloses the unique physical properties of polyimides containing an isocyanurate skeleton. As such, diamine monomers having an isocyanurate skeleton are essential for introducing specific structures into resins such as polyamides, polyimides, and polybenzoxazoles, and various examples have been reported. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] WO2020 / 196718 [Patent Document 2] Patent No. 6513012 [Patent Document 3] Patent Publication No. 2014-58452 [Patent Document 4] Patent No. 4868167 Summary of the Invention [Problem to be solved by the invention]

[0005] On the other hand, diol monomers are also important in introducing specific structures into resins. For example, resins such as polyester, polyurethane, and polycarbonate can be obtained from diol monomers. The introduction of an isocyanurate skeleton into these resin systems is desirable from the viewpoint of expressing properties such as heat resistance, mechanical strength, moisture resistance, and electrical properties. However, there have been limited reports of isocyanurate compounds having hydroxy groups. In light of the above-mentioned circumstances, an object of the present invention is to provide a novel diol compound having an isocyanurate skeleton. [Means for solving the problem]

[0006] The present invention can solve the above problems by providing the following novel diol compound containing an isocyanurate skeleton.

[0007] [1] A compound represented by general formula (1): (wherein R is a hydrogen atom or a monovalent organic group.) [ka]

[0008] [2] The compound according to [1], wherein R in general formula (1) is a monovalent hydrocarbon group having 60 or less carbon atoms. [Effects of the Invention]

[0009] The diol compound having an isocyanuric acid skeleton of the present invention can impart the rigidity characteristic of isocyanurates to urethanes, polyesters, polycarbonates, etc. Furthermore, the substituent on the isocyanurate ring (R in general formula (1)) can be varied in various ways, which significantly broadens the options when synthesizing resins with various properties. DETAILED DESCRIPTION OF THE INVENTION

[0010] Although the embodiments of the present invention are described below, the present invention is not limited thereto. All academic documents and patent documents described in this specification are incorporated herein by reference. Unless otherwise specified in this specification, "A to B" representing a numerical range means "A or more (including A and greater than A) and B or less (including B and less than B)."

[0011] The diol compound having an isocyanurate skeleton of the present invention has phenyl groups bonded to two of the three nitrogen atoms on the isocyanurate ring, and a hydroxyl group bonded to the phenyl group. Furthermore, a hydrogen atom or a substituent is bonded to the remaining nitrogen atom on the isocyanurate ring, and is a diol compound represented by general formula (1). (In the formula, R represents a hydrogen atom or a monovalent organic group.)

[0012] The first feature of the present invention is that it is a diol compound with an isocyanurate as the central skeleton. As explained below, when an isocyanate compound is reacted, three molecules are usually condensed to give a trifunctional compound, but by utilizing a specific reaction, it is possible to make it bifunctional.

[0013] The second feature is that various substituents R can be introduced into the diol compound of the present invention. This allows the resin to be given diverse properties when used as a resin raw material, and also significantly expands the variety of monomers that can be selected. This is not easy to achieve with a benzene ring as the central skeleton. [ka]

[0014] An example of a synthesis scheme for obtaining the diol compound of the present invention will be shown below. [ka]

[0015] In reaction (A), a solution of an isocyanate compound (1-1), such as 3-methoxyphenyl isocyanate or 4-methoxyphenyl isocyanate, dissolved in a solvent is added dropwise to a cyanate salt dispersed in a solvent. After the reaction, the solvent is distilled off under reduced pressure, and the resulting mixture is separated several times using an appropriate organic solvent and water. The aqueous layer is then recovered and a Brønsted acid is added to precipitate the isocyanurate compound (1-2). After the product is recovered, it may be further purified by washing or recrystallization.

[0016] Examples of the solvent for this reaction and the solvent for the dropping solution include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N,N-dimethylpropanamide, 3-methoxy-N,N-dibutylpropanamide, dimethyl sulfoxide, and 1,4-dioxane. Of these, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone are preferred.

[0017] Examples of cyanate that can be used include potassium cyanate and sodium cyanate. The reaction is carried out at a temperature of 25°C to 150°C, preferably 40°C to 120°C, and more preferably 60°C to 100°C. The reaction time for dropwise addition is 10 to 120 minutes, preferably 15 to 60 minutes.

[0018] After the dropwise addition, the reaction is continued for 10 minutes to 6 hours, preferably 15 minutes to 3 hours. The organic solvent used for separation is not particularly limited, but hexane, toluene, ethyl acetate, diethyl ether, methylene chloride, chloroform, etc. can be used, and a combination of these may also be used. Examples of acids to be added to the aqueous layer after separation include hydrochloric acid, sulfuric acid, and acetic acid, with hydrochloric acid being preferred. When recrystallizing the obtained solid, alcohols such as ethanol and 2-propanol, or esters such as ethyl acetate and butyl acetate can be used, with ethanol being particularly preferred.

[0019] When R is a hydrogen atom, step (B) of introducing the substituent R can be omitted and the process can proceed to the demethylation reaction step (C). Here, the case where R is other than a hydrogen atom will be described. The substituent R can be introduced by dissolving the isocyanurate compound (1-2) and a base in an appropriate solvent, and adding 1.0 to 2.0 equivalents, preferably 1.1 to 1.5 equivalents, of the compound RX, which is the source of introducing the substituent R, relative to the isocyanurate, and carrying out the reaction.

[0020] Here, R is a monovalent organic group, and X is a leaving group of any type, including chloro, bromo, iodo, tosyloxy, mesyloxy, and trifluoromethanesulfonyloxy. The substituent R is a monovalent organic group, and is not particularly limited, including alkyl groups such as methyl, ethyl, n-propyl, n-butyl, s-butyl, and t-butyl, and hydrocarbon groups containing carbon-carbon double or triple bonds such as allyl, homoallyl, cinnamyl, and propargyl. Heteroatom-containing substituents such as glycidyl and oxetanyl are also acceptable.

[0021] There is a wide range of variations in the substituent R, and by varying the substituent, it is possible to achieve the desired material properties, resin polymerizability, etc. When the substituent R is a hydrogen atom (when no substituent is substantially introduced), the NH bond of the isocyanurate ring functions as an acid. Therefore, it is possible to use the diol compound of the present invention as an acid group without actively introducing the substituent R. It is also possible to introduce the diol compound as a monomer into the main resin skeleton without introducing the substituent R, and then introduce a substituent or use it as a crosslinking point. In the present invention, the advantage of using an isocyanurate ring rather than a benzene ring as the central skeleton of the diol is not only the unique rigidity and stacking properties of isocyanurates, but also the ease of introducing a substituent.

[0022] The base is not particularly limited, but examples thereof include triethylamine, diisopropylethylamine, pyridine, quinoline, isoquinoline, 3,5-lutidine, 2,6-lutidine, and picoline. Inorganic bases such as sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, and sodium hydride can also be used. The base can be used in an amount of 1.0 to 3.0 equivalents relative to the substrate (1-2), preferably 1.1 to 2.0 equivalents.

[0023] The solvent for this reaction is not particularly limited, but examples thereof include tetrahydrofuran, 1,4-dioxane, acetone, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N,N-dimethylpropanamide, 3-methoxy-N,N-dibutylpropanamide, and dimethyl sulfoxide.

[0024] The reaction can be carried out at a temperature of 20°C to 120°C, preferably 40°C to 100°C, and more preferably 50°C to 90°C. The reaction time can be 1 to 12 hours, preferably 2 to 6 hours. After the reaction, the solvent may be distilled off under reduced pressure, and an appropriate purification procedure may be carried out. For example, purification by liquid separation, recrystallization, or column chromatography may be mentioned, and these may be carried out alone or in combination.

[0025] Step (C) is a demethylation reaction, and known demethylation methods can be used. Examples include methods using strong Lewis acids such as boron tribromide or aluminum chloride, methods using hydrobromic acid as a Bronsted acid, and methods using alkylthiols under basic conditions. After the reaction is complete, the product can be purified by common organic chemistry purification procedures such as separation, recrystallization, and column chromatography, as described above.

[0026] (Application) The diol compound of the present invention can be used as a polymerization monomer to impart unprecedented properties to any resin material, such as thermoplastic resins, thermosetting resins, cation-curable resins, anion-curable resins, radical-curable resins, etc. By introducing the rigid structure of isocyanurate and alkyne into the main chain skeleton of the resin, it is possible to improve mechanical strength, heat resistance, chemical resistance, hydrolysis resistance, etc.

[0027] When the diol compound of the present invention is used as a monomer for polymerizing a resin, the type of resin is not particularly limited, but it is particularly suitable for use in resins that can generally be polymerized using the diol compound as a monomer, such as polyester, polyurethane, polycarbonate, and resins containing these as part of the repeating unit.

[0028] The diol compound of the present invention or a resin obtained using the compound can be used in various applications, such as adhesives, pressure-sensitive adhesives, electronic materials, insulating materials (including printed circuit boards, electric wire coatings, etc.), high-voltage insulating materials, interlayer insulating films, TFT passivation films, TFT gate insulating films, TFT interlayer insulating films, TFT transparent planarizing films, insulating packings, insulating coating materials, adhesives, highly heat-resistant adhesives, highly heat-dissipating adhesives, optical adhesives, adhesives for LED elements, adhesives for various substrates, adhesives for heat sinks, paints, UV powder paints, inks, colored inks, UV inkjet inks, coating materials (including hard coats, sheets, films, release paper coats, optical disk coats, and optical fiber coats), and molding materials (including sheets, films, FRP, etc.). ), sealing materials, potting materials, encapsulating materials, encapsulating materials for light-emitting diodes, liquid crystal sealants, sealants for display devices, encapsulating materials for electrical materials, encapsulating materials for various solar cells, high-heat-resistant sealants, resist materials, liquid resist materials, colored resists, dry film resist materials, solder resist materials, binder resins for color filters, transparent planarizing materials for color filters, binder resins for black matrices, photospacer materials for liquid crystal cells, transparent encapsulating materials for OLED elements, photolithography, materials for solar cells, materials for fuel cells, display materials, recording materials, vibration-proof materials, waterproof materials, moisture-proof materials, photosensitive drums for copiers, solid electrolytes for batteries, etc. The isocyanuric acid skeleton-containing polymer may also be used as an additive to other resins, etc. Needless to say, the uses are not limited to those listed below. [Example]

[0029] The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples.

[0030] Example 1 A reaction vessel was charged with 1 L of N,N-dimethylformamide (hereinafter referred to as DMF) and 48.7 g of potassium cyanate and heated to 75°C. A solution of 149 g of 4-methoxyphenyl isocyanate dissolved in 500 mL of DMF was added dropwise over 30 minutes using a dropping funnel, and the mixture was stirred for 1 hour after the dropwise addition to complete the reaction. The DMF was removed under reduced pressure, and 1 L of ethyl acetate and 3 L of water were added for phase separation. The aqueous layer was isolated, and concentrated hydrochloric acid was added, and the precipitate was collected. This crude product was washed several times with water and then recrystallized from ethanol to obtain 81.9 g of isocyanurate compound (2).

[0031] Of this, 17.1 g was dissolved in 100 mL of N-methyl-2-pyrrolidone, and 15.1 g of 1-dodecanethiol and 3.00 g of sodium hydroxide were added, followed by heating and stirring at 130°C for 3 hours. After cooling, the reaction solution was poured into water to recover a solid crude product. This crude product was washed twice more with water and recrystallized from ethanol to obtain 9.31 g of the following diol compound (3). [ka] [ka]

[0032] Example 2 34.1 g of compound (2) obtained in Example 1 was dissolved in 500 mL of N-methyl-2-pyrrolidone, and 4.39 g of sodium hydroxide and 13.3 g of allyl bromide were added, followed by stirring at 70°C for 1 hour. After the reaction, 30.3 g of dodecanethiol and 6.00 g of sodium hydroxide were added, followed by heating and stirring at 130°C for 3 hours. After cooling, the reaction solution was poured into water to recover a solid crude product. This crude product was washed twice more with water and recrystallized from ethanol to obtain 19.7 g of the following diol compound (4). [ka]

[0033] Example 3 A reaction vessel was charged with 1 L of N,N-dimethylformamide (hereinafter referred to as DMF) and 48.7 g of potassium cyanate and heated to 75°C. A solution of 149 g of 3-methoxyphenyl isocyanate dissolved in 500 mL of DMF was added dropwise over 30 minutes using a dropping funnel, and the mixture was stirred for 1 hour after the dropwise addition to complete the reaction. The DMF was removed under reduced pressure, and 1 L of ethyl acetate and 3 L of water were added for phase separation. The aqueous layer was isolated, and concentrated hydrochloric acid was added, and the precipitate was collected. This crude product was washed several times with water and then recrystallized from ethanol to obtain 73.4 g of isocyanurate compound (5).

[0034] Of this, 17.1 g was dissolved in 100 mL of N-methyl-2-pyrrolidone, and 15.1 g of 1-dodecanethiol and 3.00 g of sodium hydroxide were added, followed by heating and stirring at 130°C for 3 hours. After cooling, the reaction solution was poured into water to recover a solid crude product. This crude product was washed twice more with water and recrystallized from ethanol to obtain 7.93 g of the following diol compound (6). [ka] [ka]

[0035] Example 4 34.1 g of compound (6) obtained in Example 3 was dissolved in 500 mL of N-methyl-2-pyrrolidone, and 4.39 g of sodium hydroxide and 13.3 g of allyl bromide were added, followed by stirring at 70°C for 1 hour. After the reaction, 30.3 g of dodecanethiol and 6.00 g of sodium hydroxide were added, followed by heating and stirring at 130°C for 3 hours. After cooling, the reaction solution was poured into water to recover a solid crude product. This crude product was washed twice more with water and recrystallized from ethanol to obtain 21.5 g of the following diol compound (7). [ka]

[0036] Alternatively, (3) and (6) can be synthesized in one step as follows: Example 5 A reaction vessel was charged with 1 L of DMF and 38 g of potassium cyanate and heated to 75°C. 210 g of 1-isocyanato-4-[(trimethylsilyl)oxy]benzene was added dropwise over 30 minutes using a dropping funnel, and the mixture was stirred for 1 hour after the addition to complete the reaction. The DMF was removed under reduced pressure, and 1 L of ethyl acetate and 3 L of water were added. Concentrated hydrochloric acid was added to the aqueous layer, and the precipitate was collected and recrystallized from ethanol to yield 64.3 g of compound (3).

[0037] Example 6 A reaction vessel was charged with 1 L of DMF and 38 g of potassium cyanate and heated to 75°C. 210 g of 1-isocyanato-3-[(trimethylsilyl)oxy]benzene was added dropwise over 30 minutes using a dropping funnel, and the mixture was stirred for 1 hour after the addition to complete the reaction. The DMF was removed under reduced pressure, and 1 L of ethyl acetate and 3 L of water were added. Concentrated hydrochloric acid was added to the aqueous layer, and the precipitate was collected and recrystallized from ethanol to obtain 52.5% of compound (6).

Claims

[Claim 1] A compound represented by general formula (1): (wherein R is a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a s-butyl group, a t-butyl group, an allyl group, a homoallyl group, a cinnamyl group, or a propargyl group.) 【Chemistry 1】

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