JP5659630B2 - Method for producing polyisocyanurate compound - Google Patents

Description

  The present invention relates to a method for producing a polyisocyanurate compound by polymerizing a diisocyanate compound.

  Polyisocyanurate compounds are used as raw materials for paints, adhesives, elastomers, artificial leather, foams and the like for the purpose of improving heat insulation, weather resistance, abrasion resistance, heat resistance, chemical resistance, and the like.

  Further, it is known that the polyisocyanurate compound can be produced in one pot via isocyanurate by polymerizing a diisocyanate compound. As a method for producing such a polyisocyanurate compound, for example, in order to improve heat resistance, chemical resistance and hardness, the alicyclic diisocyanate compound is self-crosslinked to a residual NCO group amount of 13% by weight or less. A method (Patent Document 1) and a method of reacting in an N, N′-dimethylformaldehyde (DMF) solvent in the presence of a nitrogen-containing heterocyclic carbene (Non-Patent Document 1) have been reported.

JP 2001-98042 A

Chem. Eur. J. 2009, 15, 1077-1081

However, the polyisocyanurate compound obtained by a conventional production method has a high residual ratio of isocyanate groups in the polyisocyanurate skeleton, and is not satisfactory in terms of thermal stability.
Accordingly, an object of the present invention is to provide a method for producing a polyisocyanurate compound having a low residual ratio of isocyanate groups and having excellent thermal stability.

In the above Patent Document 1, when a polyisocyanurate compound is synthesized by self-crosslinking a diisocyanate compound, if a solvent is present, the remaining solvent affects the physical properties of the polyisocyanurate compound. It is stated not to.
However, as a result of intensive studies to solve the above problems, the present inventors polymerized the diisocyanate compound in the presence of a specific solvent, so that the residual ratio of the isocyanate group is low and has excellent thermal stability. It has been found that a polyisocyanurate compound can be obtained.

  That is, 1) The present invention provides the following formula (1)

(In the formula, R ¹ represents a divalent hydrocarbon group having 1 to 20 carbon atoms that may have a substituent.)
Wherein the compound represented by formula (hereinafter also referred to as compound (1)) is polymerized in the presence of an oxygen-containing solvent.

(In the formula, * represents a bond, and R ¹ has the same meaning as described above.)
The manufacturing method of the polyisocyanurate compound (henceforth a compound (2)) which has a structural unit represented by these is provided.

  2) Also, the present invention provides the following formula (2)

(In the formula, R ¹ and * are as defined above.)
And a polyisocyanurate compound having a 5% weight reduction temperature of 380 ° C. or more and a 10% weight reduction temperature of 400 ° C. or more.

  According to the production method of the present invention, a polyisocyanurate compound having a low residual ratio of isocyanate groups in the molecule and having excellent thermal stability can be produced simply and efficiently.

It is a figure which shows the IR spectrum measurement result of the hardened | cured material 1. FIG. It is a figure which shows the result of TGA of the hardened | cured material 1. It is a figure which shows the result of DSC of hardened | cured material 1. It is a figure which shows the IR spectrum measurement result of hardened | cured material 2. FIG. It is a figure which shows the result of TGA of the hardened | cured material 2. It is a figure which shows the result of DSC of hardened | cured material 2. It is a figure which shows the IR spectrum measurement result of the hardened | cured material 3. FIG. It is a figure which shows the result of TGA of the hardened | cured material 3. It is a figure which shows the result of DSC of the hardened | cured material 3. It is a figure which shows the IR spectrum measurement result of the hardened | cured material. It is a figure which shows the result of TGA of the hardened | cured material 4. It is a figure which shows the result of DSC of the hardened | cured material 4.

First, definitions of symbols used in this specification will be described.
In the formula (1) and (2), R ¹ is a divalent hydrocarbon group having 1 to 20 carbon atoms that may have a substituent. The “divalent hydrocarbon group having 1 to 20 carbon atoms” is preferably a divalent hydrocarbon group having 1 to 16 carbon atoms from the viewpoint of thermal stability and reaction efficiency. A valent hydrocarbon group is more preferable, and a divalent hydrocarbon group having 5 to 14 carbon atoms is particularly preferable. Here, the “divalent hydrocarbon group” includes a divalent aliphatic hydrocarbon group, a divalent alicyclic hydrocarbon group, a divalent aromatic hydrocarbon group, and two or more selected from these. It is a concept that includes a bonded divalent hydrocarbon group. The divalent hydrocarbon group may have an unsaturated bond in the molecule.

  Although carbon number of the said bivalent aliphatic hydrocarbon group is 1-20, 1-16 are preferable from the point of thermal stability and reaction efficiency, 1-14 are more preferable, 1-12 are still more preferable, 5 to 12 is particularly preferable. The divalent aliphatic hydrocarbon group may be linear or branched. Specific examples include a methylene group, an alkylene group, an alkenylene group, and an alkynylene group, and a methylene group and an alkylene group are preferable from the viewpoint of thermal stability and reaction efficiency. Specific examples of the alkylene group include, for example, ethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, 2,2,4-trimethylhexamethylene group. 2,4,4-trimethylhexamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, etc., among these, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, 2,2,4-trimethylhexamethylene group, 2,4,4-trimethylhexamethylene group, decamethylene group, undecamethylene group and dodecamethylene group are preferred.

Moreover, although carbon number of the said bivalent alicyclic hydrocarbon group is 3-20, 3-12 are preferable and 3-8 are more preferable. Specifically, a cycloalkylene group such as a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, and a cyclohexylene group; a cycloalkenylene group such as a cyclobutenylene group, a cyclopentenylene group, and a cyclohexenylene group; -C _3-7 cycloalkylene-C _1-6 alkylene-C _3-7 such as a group represented by xylene-methylene-cyclohexylene, a group represented by -cyclohexylene-ethylene-cyclohexylene- And a group represented by cycloalkylene-. The binding site of the alicyclic hydrocarbon group may be on any carbon on the alicyclic ring.

  As carbon number of the said bivalent aromatic hydrocarbon group, 6-18 are preferable from the point of thermal stability and reaction efficiency, and 6-14 are more preferable. Specifically, arylene groups such as a phenylene group, a biphenylene group, a naphthylene group, a phenanthrene group, an anthrylene group; the following formula (3)

(In the formula, R ³ represents a divalent hydrocarbon group having 1 to 6 carbon atoms.)
The group represented by these is mentioned. Among these, a group represented by the formula (3) is preferable from the viewpoint of thermal stability, flexibility, chemical resistance, transparency, and reaction efficiency. The binding site of the aromatic hydrocarbon group may be on any carbon on the aromatic ring, but the 4-position and 4'-position are preferred.

Examples of the divalent hydrocarbon group having 1 to 6 carbon atoms represented by R ³ include those similar to the “divalent hydrocarbon group” in R ¹ , but from the viewpoint of thermal stability and reaction efficiency. , A divalent aliphatic hydrocarbon group having 1 to 6 carbon atoms is preferable, a methylene group and an alkylene group having 2 to 6 carbon atoms are more preferable, and a methylene group and an alkylene group having 2 to 3 carbon atoms are particularly preferable.

The above “divalent hydrocarbon group” is a divalent group in which two or more selected from a divalent aliphatic hydrocarbon group, a divalent alicyclic hydrocarbon group, and a divalent aromatic hydrocarbon group are bonded. Specific examples of preferred hydrocarbon groups include: a group represented by -C _1-6 alkylene-C _3-7 cycloalkylene-C _1-6 alkylene-, -C _1-6 alkylene-phenylene. -C _1-6 alkylene - groups represented mentioned in, -C _1-3 alkylene -C _3-7 cycloalkylene -C _1-3 alkylene -, a group represented by, -C _1-3 alkylene - phenylene A group represented by —C _1-3 alkylene- is preferred.

  Examples of the group that can be substituted with the above-mentioned “divalent hydrocarbon group having 1 to 20 carbon atoms” include, for example, an alkoxy group having 1 to 12 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and a cyclohexyloxy group. Alkyl group having 1 to 3 carbon atoms such as methyl group, ethyl group, n-propyl group and isopropyl group; halogen atom such as fluorine, chlorine, bromine and iodine; cyano group; amino group; oxo group; Examples include alkanoyl groups having 2 to 10 carbon atoms such as groups; alkoxycarbonyl groups such as methoxycarbonyl groups and ethoxycarbonyl groups. The position and number of these substituents are arbitrary, and when having two or more substituents, the substituents may be the same or different.

Next, the manufacturing method of this invention is demonstrated.
The method for producing the compound (2) of the present invention comprises a step of polymerizing the compound (1) in the presence of an oxygen-containing solvent.
Examples of the compound (1) used in the present invention include 1-isocyanate-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate. , Dodecamethylene diisocyanate, 2,6-diisocyanatomethyl caproate, 1,3-cyclohexyl diisocyanate, 1,4-cyclohexyl diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate) ), Methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, m-xylylene diisocyanate, p-xylylene diisocyanate, 1,3-tetramethylxylylene diisocyanate Narate, 1,4-tetramethylxylylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, methylene diphenyl-2,4'-diisocyanate, methylene diphenyl-4,4 ' -Diisocyanate, 1,5-naphthalene diisocyanate, 1,8-naphthalene diisocyanate and the like. Among these, hexamethylene diisocyanate and methylene diphenyl-4,4′-diisocyanate are preferably used from the viewpoints of thermal stability, flexibility, chemical resistance, transparency, and reaction efficiency. In addition, in the manufacturing method of this invention, the said compound (1) may be used independently, and 2 or more types may be mixed and used for it.

  The oxygen-containing solvent used in the production method of the present invention may be any solvent having an oxygen atom in the molecule. For example, imidazolidinones such as 1,3-dialkyl-2-imidazolidinone; pyrrolidone such as alkylpyrrolidone Amides such as N, N-dimethylformamide; ketones such as methyl ethyl ketone and methyl isobutyl ketone; sulfoxides such as dimethyl sulfoxide; ethers such as diethylene glycol dimethyl ether (diglyme) and triethylene glycol dimethyl ether (triglyme); A mixed solvent etc. are mentioned. Among these, from the viewpoint of thermal stability, flexibility, chemical resistance, transparency, and reaction efficiency, oxygen-containing polar solvents are preferable, oxygen-containing aprotic polar solvents are more preferable, imidazolidinones are more preferable, 2- Imidazolidinones are particularly preferred.

Moreover, as a boiling point of the said solvent, 150 degreeC or more is preferable, 150-300 degreeC is more preferable, 200-250 degreeC is especially preferable.
Preferable specific examples of the solvent include 1,3-dimethyl-2-imidazolidinone, alkylpyrrolidone, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, N, N-dimethylformamide, dimethyl sulfoxide and the like. Among them, 1,3-dialkyl-2-imidazolidinone such as 1,3-dimethyl-2-imidazolidinone, N-methyl from the viewpoint of thermal stability, flexibility, chemical resistance, transparency and reaction efficiency Alkyl pyrrolidones such as pyrrolidone are preferred, and 1,3-dialkyl-2-imidazolidinone is particularly preferred. In addition, as carbon number of this alkyl group, 1-6 are preferable.
The amount of the solvent used is preferably 10 ^{−7 to} 6 parts by mass, more preferably 10 ^{−6 to} 3 parts by mass, and more preferably 10 ⁻³ to 1 part from the viewpoint of reaction efficiency with respect to 1 part by mass of compound (1). .4 parts by mass is particularly preferred.

  The production method of the present invention can be carried out in the presence of a catalyst and in the absence of a catalyst, but is preferably carried out in the presence of a catalyst from the viewpoint of reaction efficiency. Examples of the catalyst include organic quaternary ammonium salts such as tetrabutylammonium iodide, tetrabutylammonium bromide, tetrabutylammonium fluoride, benzyltriethylammonium chloride, tetrabutylammonium hydroxide, and tetrabutylammonium hydrogen sulfate; triethylamine, dimethyl Organic tertiary amines such as octylamine and dimethyllaurylamine; organic sulfinic acids or salts thereof and the like may be used, and two or more of these may be used. Of these, organic quaternary ammonium salts and organic sulfinates are preferred from the viewpoints of thermal stability, flexibility, chemical resistance, transparency, and reaction efficiency. Among these, organic sulfinates are particularly preferable from the viewpoint of achieving both color tone and transparency.

The organic sulfinate is preferably an aromatic sulfinate from the viewpoint of thermal stability, flexibility, chemical resistance, color tone, transparency and reaction efficiency. Examples of the salt include alkali metal salts and alkaline earth metal salts. Specific examples include alkali metal salts of p-toluenesulfinic acid, alkali metal salts of o-toluenesulfinic acid, and alkaline earth metal salts of benzenesulfinic acid. Among these, an alkali metal salt of p-toluenesulfinic acid is particularly preferable from the viewpoint of achieving both color tone and transparency.
The amount of the catalyst used is preferably 10 ^{−4 to} 0.5 part by mass, and more preferably 10 ^{−3 to} 0.1 part by mass with respect to 1 part by mass of the compound (1).

  Although the reaction temperature of the said reaction is not specifically limited, 20-200 degreeC is preferable. Moreover, it is preferable to perform the said reaction in inert gas atmosphere from the point of reaction efficiency. The inert gas is not particularly limited, and examples thereof include argon gas, nitrogen gas, and helium gas.

  In the production method of the present invention, from the viewpoint of flexibility, in addition to the compound (1), (i) a polyalkylene glycol compound, (ii) a polyvinyl compound, (iii) a polyallyl compound, and (iv) poly ( One or more compounds selected from a (meth) acrylic compound may be used in combination.

  (I) Examples of the polyalkylene glycol compound include polyethylene glycol (PEG) and polypropylene glycol. Among these, polyethylene glycol is preferable.

  (Ii) Examples of the polyvinyl compound include divinylbenzene and N, N-methylenebisacrylamide.

  (Iii) Examples of the polyallyl compound include N, N-diallylacrylamide, diallylamine, diallylmethacrylamide, diallyl phthalate, diallyl malate, diallyl terephthalate, triallyl cyanurate, triallyl phosphate and the like.

  (Iv) As the poly (meth) acrylic compound, (a) ethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6 -Hexanediol di (meth) acrylate, cyclohexanedimethanol di (meth) acrylate, alkoxylated hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, caprolactone modified neopentyl glycol hydroxypivalate di (meth) acrylate , Cyclohexanedimethanol di (meth) acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, bisphenol-A di (meth) acrylate, ethoxylated bisphenol -A di (meth) acrylate, hydroxypivalaldehyde-modified trimethylolpropane di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, propoxy Neopentyl glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, triethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, etc. Functional acrylate compounds; (b) glycerol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethoxylated tri (meth) acrylate (e.g. Toxylated trimethylolpropane tri (meth) acrylate, etc.), pentaerythritol tri (meth) acrylate, glycerin tri (meth) acrylate, propoxylated tri (meth) acrylate (eg propoxylated glyceryl tri (meth) acrylate, propoxylated tri Trifunctional acrylate compounds such as methylolpropane tri (meth) acrylate) and tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate; (c) ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol penta (meth) Acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) Tetrafunctional or more acrylate compounds such as acrylate.

  Although the usage-amount of the said compounds (i)-(iv) is not specifically limited, From the point of thermal stability and a softness | flexibility, for example, it is 20 mass% or less with respect to a compound (1), Preferably it is 10 mass% or less. is there.

  Compound (2) can be separated from the reaction system by isolation and purification by appropriately combining ordinary means such as filtration, washing, drying, recrystallization, centrifugation, extraction with various solvents, chromatography and the like. it can.

Further, the compound (2) obtained by the production method of the present invention has a high conversion rate of isocyanate group in the molecule of 95% or more, preferably 99% or more, as shown in the following Examples. Since the residual rate of is low, it has excellent thermal stability.
Further, the 5% weight loss temperature (T _d5 ) of the compound (2) is preferably 380 ° C. or higher, more preferably 400 to 600 ° C., further preferably 405 to 500 ° C., and particularly preferably 410 to 450 ° C. Further, the 10% weight loss temperature (T _d10 ) is preferably 400 ° C. or more, more preferably 420 to 600 ° C., further preferably 425 to 550 ° C., further preferably 430 to 500 ° C., particularly 440 to 475 ° C. preferable. And in a thermogravimetric analysis (TGA), what does not have a weight reduction of a compound (2) to 400 degreeC is preferable.
The measurement of T _d5 and T _d10 is subject to the conditions described in the examples below.
Moreover, the lower limit of the residual carbon ratio at 500 ° C. is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more. The upper limit is preferably 100% by mass. Here, the residual carbon ratio refers to the mass ratio of carbon remaining when the compound is heated from 50 ° C. to 500 ° C. by 10 ° C. and fired for 45 minutes in a non-oxidizing atmosphere.
Further, the glass transition temperature of the compound (2) is not particularly limited, but from the viewpoint of thermal stability, the lower limit is preferably 100 ° C, more preferably 250 ° C, further preferably 275 ° C, particularly preferably 300 ° C. On the other hand, the upper limit is preferably 450 ° C., particularly preferably 400 ° C.

Moreover, as a Young's modulus (GPa) of a compound (2), 0.5-2 are preferable. Further, the elongation at break (%) is preferably 3 or less.
In addition, the measurement of a Young's modulus and breaking elongation rate shall follow the conditions as described in the following Example.

Accordingly, the compound (2) is a film or sheet such as a heat resistant film or sheet or an optical film or sheet, a lens material, an optical communication part, an optical material such as an optical disk, a coating agent, a polyisocyanurate molded product, a polyisocyanate. It is useful as a raw material for nurate moldings, polyisocyanurate foams, rigid polyurethane foams, paints, adhesives, elastomers, artificial leather, flame retardant low dielectric constant thermosetting materials, and semiconductor resist materials. In addition, when making a compound (2) into the form of a film or a sheet | seat, it can manufacture by a well-known method using a spin coater, a bar coater, a spray coat, an inkjet, or a die coater.
Further, the molded body may be molded according to a conventional method, and examples thereof include extrusion molding and compression molding. When the compound (2) is used as a raw material for a polyisocyanurate molded article, other polymers such as foaming agents, foam stabilizers, polyols, additives, fillers, and the like may be used.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited by these.

The reagents used in the examples are as shown below.
1,6-hexamethylene diisocyanate was purchased from Tokyo Chemical Industry, and methylene diphenyl-4,4′-diisocyanate (methylene diphenyl 4,4′-diisocyanate) was purchased from Wako Pure Chemical Industries, Ltd. Used by distillation under reduced pressure.
Further, sodium p-toluenesulfinate was purchased from Tokyo Chemical Industry, and tetrabutylammonium iodide was purchased from Wako Pure Chemical Industries, Ltd., both of which were used after drying under reduced pressure at room temperature.
1,3-dimethyl-2-imidazolidinone was purchased from Wako Pure Chemical Industries, dried over calcium hydride, and then used after vacuum distillation.

The analysis conditions of the cured product in the examples are as shown below.
<IR spectrum>
Absorption derived from isocyanate was confirmed by IR spectrum, and the conversion rate of isocyanate group was determined. The IR spectrum was measured by the ATR method using a NICOLET iS10 with a SMARTiTR sampling unit manufactured by Thermo Scientific.

<Thermogravimetric analysis>
Thermogravimetric analysis (TGA) was measured with a TG-DTA6200 manufactured by Seiko Instruments Inc. by using an aluminum pan and raising the temperature in a nitrogen stream of 50 mL / min at 10 ° C./min. In thermogravimetric analysis, T _d5 and T _d10 mean 5% weight reduction temperature and 10% weight reduction temperature of the compound, respectively.

<Differential scanning thermal analysis>
Differential scanning calorimetry (DSC) was performed using a DSC6200 manufactured by Seiko Instruments Inc., and 10 mg of the cured product was enclosed in an aluminum pan and heated from 50 ° C. to 300 ° C. at a rate of 5 ° C./min in a nitrogen stream. And measured.

<Flexibility test>
Flexibility was measured by a tensile test. That is, with a stress / strain control TMA device (manufactured by SII Nano Technology Co., Ltd.), a cured product (3 mm × 10 mm) was subjected to a load of 5.9 N at room temperature and atmospheric pressure and strained to 1000 μm at 10 μm / min. The measurement was performed by determining the Young's modulus (GPa) and the elongation at break (%).

<Chemical resistance test>
The cured product was immersed in a 5% hydrochloric acid solution and a 5% sodium hydroxide solution at room temperature for two days, and the subsequent appearance was observed.

Example 1 Synthesis of polyisocyanurate compound (1)
According to the following synthesis route (self-crosslinking reaction), a polyisocyanurate compound was synthesized (networked) using 1,6-hexamethylene diisocyanate (HMDI) as a substrate.

Sodium p-toluenesulfinate (27 mg, 0.15 mmol) and tetrabutylammonium iodide (TBAI, 28 mg, 0.075 mmol) were added to 1,3-dimethyl-2-imidazolidinone (DMI, 1.0 mL). Dissolved. HMDI (1.2 mL, 7.5 mmol) was added to this solution and stirred at 150 ° C. for 2 hours under a nitrogen atmosphere to obtain a HMDI varnish. Subsequently, the obtained varnish was poured into a petri dish to obtain a light yellow transparent film-like cured product 1.
After this cured product 1 was cooled to room temperature, absorption of isocyanate groups was confirmed by IR spectrum.
As a result of the IR spectrum (FIG. 1), the absorption derived from the isocyanate group near 2200 cm ⁻¹ almost completely disappeared, and the absorption near 1700 cm ⁻¹ derived from the carbonyl group of the isocyanurate skeleton was newly increased. From this result, it was found that the isocyanate group was almost completely consumed (conversion rate of 99%) and was networked in a high density with an isocyanurate skeleton.

The obtained cured product 1 was Soxhlet extracted with chloroform for 24 hours, dried in a vacuum dryer at 120 ° C. overnight, and then subjected to TGA and DSC. The results of TGA are shown in FIG. 2, and the results of DSC are shown in FIG.
Further, T _d5 , T _d10 , and glass transition temperature of the cured product 1 measured by the TGA are shown in Table 1 below.

As a result of TGA, weight reduction of the cured product 1 was not observed up to 400 ° C., and T _d5 and T _d10 were 431 ° C. and 449 ° C., respectively.
Moreover, it turned out that the glass transition temperature (Tg) of the hardened | cured material 1 is 114 degreeC from the result of DSC.

Example 2 Synthesis of polyisocyanurate compound (2)
According to the following synthesis route (self-crosslinking reaction), a polyisocyanurate compound was synthesized (networked) using methylenediphenyl-4,4′-diisocyanate (MDI) as a substrate.

MDI (0.75 g, 3 mmol) was dissolved in DMI (0.7 mL) and this solution was mixed with sodium p-toluenesulfinate (5.4 mg, 0.03 mmol) and TBAI (5.5 mg, 0.015 mmol). The solution dissolved in DMI (0.3 mL) was mixed under a nitrogen atmosphere and allowed to stand at room temperature for 15 minutes. The reaction proceeded quickly (pot life about 1 minute), and an MDI varnish was obtained in 15 minutes. Subsequently, the obtained varnish was poured into a petri dish to obtain a light yellow transparent film-like cured product 2.
As a result of IR spectrum of cured product 2 (FIG. 4), the absorption derived from the isocyanate group near 2200 cm ⁻¹ almost completely disappeared, and the absorption near 1700 cm ⁻¹ derived from the carbonyl group of the isocyanurate skeleton increased. It was. From this result, it was found that the isocyanate group was almost completely consumed (conversion rate of 99%) and was networked in a high density with an isocyanurate skeleton.

The cured product 2 was subjected to Soxhlet extraction with chloroform for 24 hours and dried overnight in a vacuum dryer at 120 ° C., and then TGA and DSC were performed. The TGA result of the cured product 2 is shown in FIG. 5, and the DSC result is shown in FIG.
Table 2 below shows T _d5 , T _d10 , residual carbon ratio at 500 ° C., and glass transition temperature of cured product 2 measured by the TGA.

As a result of TGA, weight reduction of cured product 2 was not observed up to 400 ° C., and T _d5 and T _d10 were 411 and 445 ° C., respectively. Furthermore, the hardened | cured material 2 showed the high residual carbon rate of 70 mass% or more also under 500 degreeC.
Moreover, as a result of DSC, glass transition did not occur up to 300 ° C. From this result, it was found that the glass transition temperature (Tg) of the cured product 2 is a temperature exceeding at least 300 ° C., and the cured product 2 has extremely high heat resistance.

Example 3 Synthesis of polyisocyanurate compound (3)
The synthesis was performed in the same manner as in Example 2 except that the type of catalyst was changed.
That is, MDI (0.75 g, 3 mmol) was dissolved in DMI (0.4 mL), and this solution and sodium p-toluenesulfinate (5.3 mg, 0.03 mmol) were dissolved in DMI (0.6 mL). The solution was mixed under a nitrogen atmosphere and allowed to stand at room temperature for 15 minutes. The reaction proceeded quickly (pot life about 1 minute), and an MDI varnish was obtained in 15 minutes. Next, the obtained varnish was poured into a petri dish to obtain a cured product 3 in the form of a colorless transparent film.

As a result of IR spectrum of the cured product 3 obtained in Example 3 (FIG. 7), absorption derived from an isocyanate group near 2200 cm ⁻¹ almost completely disappeared, and a new 1700 cm derived from a carbonyl group of an isocyanurate skeleton was newly obtained. Absorption near ^-1 increased. From this result, it was found that the isocyanate group was almost completely consumed (conversion rate of 99%) and was networked in a high density with an isocyanurate skeleton.

The cured product 3 was subjected to Soxhlet extraction with chloroform for 24 hours, dried overnight in a vacuum dryer at 120 ° C., and then subjected to TGA and DSC. The TGA result of the cured product 3 is shown in FIG. 8, and the DSC result is shown in FIG.
Table 3 below shows T _d5 , T _d10 , residual carbon ratio at 500 ° C., Young's modulus, elongation at break, and chemical resistance measured by TGA.

As a result of TGA, almost no weight reduction of the cured product 3 was observed up to 400 ° C., and T _d5 and T _d10 were 446 and 465 ° C., respectively. Furthermore, the hardened | cured material 3 showed the high residual carbon ratio (75 mass%) also under 500 degreeC.

  Moreover, as a result of DSC, glass transition did not occur up to 300 ° C. From this result, it was found that the glass transition temperature (Tg) of the cured product 3 is a temperature exceeding at least 300 ° C., and the cured product 2 has extremely high heat resistance.

From the result of the flexibility test, the cured product 3 showed a high Young's modulus (GPa) and an excellent elongation at break (%).
From this result, it was found that the cured product 3 has excellent flexibility.

As a result of the chemical resistance test, no change in the appearance of the cured product 3 could be confirmed when either a hydrochloric acid solution or a sodium hydroxide solution was used.
From this result, it was found that the cured product 3 has excellent chemical resistance.

Example 4 Synthesis of polyisocyanurate compound (4)
MDI (0.75 g, 3 mmol) was dissolved in DMI (0.5 mL), and this solution was dissolved in p-toluenesulfinate sodium (0.27 mg, 0.0015 mmol) in DMI (0.5 mL). Were mixed under a nitrogen atmosphere to obtain an MDI varnish. This varnish retained fluidity for 30 minutes after mixing (pot life 30 minutes).
Next, the obtained varnish was coated on a substrate with a coater, and then heated at 120 ° C. for 2 hours. Thus, a colorless transparent film-like cured product 4 was obtained in 2 hours.

As a result of IR spectrum of cured product 4 obtained in Example 4 (FIG. 10), absorption derived from an isocyanate group near 2200 cm ⁻¹ almost completely disappeared, and 1700 cm newly derived from a carbonyl group of an isocyanurate skeleton. Absorption near ^-1 increased. From this result, it was found that the isocyanate group was almost completely consumed (conversion rate of 96%) and was networked in a high density with an isocyanurate skeleton.

The cured product 4 was subjected to Soxhlet extraction with chloroform for 24 hours, dried overnight in a vacuum dryer at 150 ° C., and then subjected to TGA and DSC. The TGA result of the cured product 4 is shown in FIG. 11, and the DSC result is shown in FIG.
Further, Table 4 below shows T _d5 , T _d10 , residual carbon ratio under 500 ° C., and glass transition temperature of the cured product 4 measured by the TGA.

As a result of TGA, almost no weight reduction of the cured product 4 was observed up to 400 ° C., and T _d5 and T _d10 were 444 and 463 ° C., respectively. Furthermore, the hardened | cured material 4 showed the high residual carbon ratio (74 mass%) even under 500 degreeC.
Moreover, as a result of DSC, glass transition did not occur up to 300 ° C. From this result, it was found that the glass transition temperature (Tg) of the cured product 4 is a temperature exceeding at least 300 ° C., and the cured product 4 has extremely high heat resistance.

The polyisocyanurate compound obtained by the production method of the present invention has flexibility, chemical resistance and transparency, and has a very low residual ratio of isocyanate groups, and thus has high heat resistance and thermal stability. .
Accordingly, the high molecular weight polyisocyanurate obtained in the present invention is an optical material such as a lens material, an optical communication component, a heat resistant film or sheet, an optical film or sheet, a flame retardant low dielectric constant thermosetting material, and an optical disk. It can be used as a resist material for semiconductors.

Claims (11)

Following formula (1)

(In the formula, R ¹ represents a divalent hydrocarbon group having 1 to 20 carbon atoms.)
The compound represented by, saw including a step of polymerizing in the presence of oxygen-containing solvent and an organic sulfinate, as the oxygen-containing solvent, characterized by using 2-imidazolidinone represented by the following formula (2)

(In the formula, * represents a bond, and R ¹ has the same meaning as described above.)
The manufacturing method of the polyisocyanurate compound which has a structural unit represented by these. The production method according to claim 1, wherein the 2-imidazolidinone is 1,3-dialkyl-2-imidazolidinone. The production method according to claim 2, wherein the 1,3-dialkyl-2-imidazolidinone is 1,3-dimethyl-2-imidazolidinone. The manufacturing method according to any one of claims 1 to 3, wherein the amount of the organic sulfinate used is ^{10-4 to} 0.5 parts by mass with respect to 1 part by mass of the compound represented by the formula (1). The method according to any one of claims 1 to 4 , wherein the organic sulfinate is an aromatic sulfinate. 2. The organic sulfinate is one or more selected from an alkali metal salt of p-toluenesulfinic acid, an alkali metal salt of o-toluenesulfinic acid, and an alkaline earth metal salt of benzenesulfinic acid. -5. The manufacturing method in any one of 5 . The method according to any one of claims 1-6 boiling point of the 2-imidazolidinone is 0.99 ° C. or higher. R < ¹ > is a C5-C14 bivalent hydrocarbon group, The manufacturing method in any one of Claims 1-7. A polyisocyanurate compound obtained by the production method according to claim 1, wherein the following formula (2):

(In the formula, R ¹ represents a divalent hydrocarbon group having 1 to 20 carbon atoms, and * represents a bond.)
A polyisocyanurate compound having a structural unit represented by the formula: 5% weight loss temperature of 380 ° C. or higher and 10% weight loss temperature of 400 ° C. or higher. R ¹ is an alkylene group having 1 to 20 carbon atoms, or the following formula (3)

(In the formula, R ³ represents an alkylene group having 1 to 6 carbon atoms.)
The compound of Claim 9 which is group represented by these.   The compound according to claim 9 or 10, wherein the residual carbon ratio at 500 ° C is 50% or more and the glass transition temperature is 275 ° C or more.

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