JP5925405B2 - Thermosetting resin composition - Google Patents

Description

  The present invention relates to a thermosetting resin composition.

  Polyurethane resins are widely used in the industrial and daily life fields because of their excellent mechanical properties such as toughness and strength. For example, Patent Document 1 discloses that a polyurethane resin is used as an adhesive film for bonding a semiconductor chip and a semiconductor mounting organic substrate.

  Among polyurethane resins, cured products of polyurethane resins using alicyclic polyisocyanates provide sufficient transparency in the near-ultraviolet region and are excellent in coloration resistance. Used for applications. On the other hand, alicyclic polyisocyanates are less reactive with polyols than aromatic isocyanates due to electronic and steric structural factors.

The molding method of the polyurethane resin cured product includes a casting method in which a mixture of a liquid polyisocyanate-containing resin and a liquid polyol-containing resin is poured into a mold and thermally cured, and then cooled and removed from the mold. There is known a reaction, injection, molding method, etc., in which the above mixture is poured into a mold while being pressed and cured by pressing and heating in a short time and then removed from the mold, but the above mixture can be cured in a shorter time. It has been demanded. For this reason, in general, a basic catalyst or a metal salt catalyst is added to the mixture in order to accelerate the curing reaction.
JP 2000-106372 A Journal of Applied Polymer Science, Vol. 23, 1385-1396 (1979)

  However, it is clear that basic catalysts and metal salt catalysts as catalysts for urethanization reactions are not sufficient for use in molding polyurethane resins for optical applications because they may cause the polyurethane resin cured product to be colored. It became.

  This invention is made | formed in view of such a situation, and provides the thermosetting resin composition with high reactivity of a urethanation reaction, without using a basic catalyst and a metal salt type catalyst.

  The thermosetting resin composition according to the present invention contains a polyisocyanate, a polyol, and a component that generates a Bronsted acid by heating.

  In the thermosetting resin composition according to the present invention, Bronsted acid that is a reaction accelerator for the urethanization reaction between polyisocyanate and polyol is generated by heating. And this Bronsted acid acts on the isocyanate group of polyisocyanate, and it will be in the state which the said isocyanate group and the hydroxyl group of a polyol react easily. Thereby, the reactivity of a urethanation reaction can be improved. Moreover, since it is not necessary to add the catalyst which has a bad influence on the color of hardened | cured material for acceleration | stimulation of urethanation reaction, coloring of hardened | cured material can be suppressed.

  The Bronsted acid is preferably an oxonium ion. Moreover, it is preferable that the component which generate | occur | produces a Bronsted acid contains the compound which has an epoxy group, and a quaternary phosphonium salt. Furthermore, the quaternary phosphonium salt is preferably a tetraalkylphosphonium salt.

  The polyisocyanate preferably contains a prepolymer obtained by reacting a polyisocyanate and a polyol having a total number of hydroxyl groups smaller than the total number of isocyanate groups of the polyisocyanate. The polyol preferably contains a prepolymer obtained by reacting a polyol and a polyisocyanate having a total number of isocyanate groups smaller than the total number of hydroxyl groups of the polyol. In such a thermosetting resin composition, the compatibility can be improved as compared with the case where each of polyisocyanate and polyol is used alone. Therefore, a thermosetting resin composition suitable for molding methods such as a casting method and a reaction injection molding method is provided.

  The thermosetting resin composition according to the present invention is a two-component thermosetting resin comprising a liquid A containing polyisocyanate and a quaternary phosphonium salt, and a liquid B containing a polyol and a compound having an epoxy group. A composition is preferred. With such a thermosetting resin composition, stability during storage, that is, pot life can be improved.

  It is preferable that polyisocyanate contains bifunctional or more alicyclic polyisocyanate. Bifunctional or higher alicyclic polyisocyanates include 4,4′-methylenebis (cyclohexyl isocyanate), isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, and norbornene diisocyanate (2,5- (2, 6) At least one selected from the group consisting of bisisocyanatomethyl [2,2,1] heptane) is preferable.

  The thermosetting resin composition according to the present invention has high reactivity of the urethanization reaction without using a basic catalyst or a metal salt catalyst, and is suitable for a molded product for optical use.

  Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

  The thermosetting resin composition according to the present invention (hereinafter sometimes referred to as “resin composition”) is a Bronsted that serves as a reaction accelerator for a urethanization reaction between a polyisocyanate, a polyol, and the polyisocyanate and the polyol. And a component that generates an acid by heating.

  As the Bronsted acid, an oxonium ion is particularly preferable. Specifically, the component that generates the Bronsted acid is preferably a combination of a compound having an epoxy group (hereinafter, sometimes referred to as “epoxy group-containing compound”) and a quaternary phosphonium salt.

  By the way, as described in Non-Patent Document 1, when a compound having an epoxy group and a quaternary phosphonium salt coexist and react by heating, an oxygen atom rich in nucleophilicity of the epoxy group is obtained in the initial process. In addition to the hydrogen atom bonded to the carbon atom adjacent to the phosphorus atom of the quaternary phosphonium salt, the oxygen atom of the epoxy group is rich in electrophilicity (see the following reaction formula (1)). In the formula (1), X represents a counter ion of a quaternary phosphonium ion, and R and R ′ represent an arbitrary substituent such as an alkyl group. Furthermore, it is considered that the oxygen atom of this epoxy group is attacked by another epoxy group to generate an oxonium ion (see the following reaction formula (2)).

  The mechanism of action produced in the present invention is estimated as follows. However, the action mechanism is not limited to this. That is, when a compound having an epoxy group and a quaternary phosphonium salt coexist in a thermosetting resin composition containing a polyisocyanate and a polyol, the oxygen atom of the generated oxonium ion is converted to the isocyanate group of the polyisocyanate. Add to oxygen atom. As a result, the carbon atom at the center of the isocyanate group is rich in electrophilicity, and it is presumed that the reaction with the oxygen atom rich in nucleophilicity of the hydroxyl group is promoted (see the following reaction formula (3)).

  The quaternary phosphonium salt according to the present invention is preferably a tetraalkylphosphonium salt. Examples of the tetraalkylphosphonium salt include tetra-n-butylphosphonium o, o-diethylphosphodithionate, methyltributylphosphonium dimethyl phosphate, tetraethylphosphonium boronide, tetra-n-butylphosphonium bromide, and tetra-n-butylphosphonium. There are benzotriazolate, tetra-n-butylphosphonium tetrafluoroborate, tetra-n-butylphosphonium tetraphenylborate, and tetra-n-butylphosphonium o, o- from the viewpoint of solubility in thermosetting resin compositions. Diethyl phosphodithionate or methyl tributyl phosphonium dimethyl phosphate is preferred.

  The compounding amount of the quaternary phosphonium salt is preferably 0.01 to 2% by mass and more preferably 0.05 to 0.1% by mass with respect to the total mass of the resin composition. If the blending amount is less than 0.01% by mass, the effect of curing acceleration is not observed, while if it exceeds 2% by mass, the colorability of the cured product may be adversely affected.

  Examples of the compound having an epoxy group according to the present invention include tris (2,3-epoxypropyl) isocyanurate, hydrogenated bisphenol A glycidyl ether, bisphenol A glycidyl ether, 3,4-epoxycyclohexylmethyl, 3,4- There are epoxycyclohexanecarboxylate and ethylene glycol diglycidyl ether.

  It is preferable that the compounding quantity of the compound which has an epoxy group is 0.1-10 mass% with respect to the total mass of a resin composition, and it is more preferable that it is 0.5-5.0 mass%. When the blending amount is less than 0.1% by mass, the effect of curing acceleration is not observed. On the other hand, when it exceeds 10% by mass, there are problems such as solubility in the resin composition and coloration of the cured product.

  The polyisocyanate according to the present invention preferably contains a bifunctional or higher functional polyisocyanate, and is not particularly limited. However, for the alicyclic polyisocyanate having low reactivity with the polyol, the reactivity of the urethanization reaction Can be improved effectively. As the bifunctional or higher alicyclic polyisocyanate, for example, alicyclic diisocyanate is preferable, and specifically, 4,4′-methylenebis (cyclohexyl isocyanate), isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane. , And norbornene diisocyanate (2,5- (2,6) bisisocyanatomethyl [2,2,1] heptane), or a mixture thereof is preferable. Further, in addition to the above bifunctional or higher alicyclic polyisocyanate, for example, an isocyanurate type, biuret type or adduct type polyisocyanate made from hexamethylene diisocyanate may be included, and hexamethylene diisocyanate was used. Isocyanurate type polyisocyanates are particularly preferred.

  The polyol according to the present invention is not particularly limited, and examples thereof include aliphatic polyols, alicyclic polyols, polyether polyols, carbonate polyols, polyester diols, polycaprolactone polyols, and acrylic resin polyols. In order to obtain a soft cured product, a polyol having a smaller hydroxyl equivalent, for example, a high molecular weight, bifunctional polyether diol, carbonate diol, or polyester diol is preferable. On the other hand, in the case of obtaining a hard cured product, a polyol having a larger hydroxyl equivalent, for example, a low molecular weight difunctional carbonate diol, caprolactone diol, trifunctional caprolactone triol, aliphatic triol trimethylolpropane, propane-1, Examples include 2,3-triol, a derivative obtained by adding ethylene oxide or propylene oxide thereto, a tetrafunctional aliphatic tetraol diglycerin, a derivative obtained by adding ethylene oxide or propylene oxide thereto, a mixture thereof, and the like.

  In the thermosetting resin composition according to the present invention, it is possible to use, as the polyisocyanate, an isocyanate group residual prepolymer obtained by reacting a polyisocyanate and a polyol having a total number of hydroxyl groups smaller than the total number of isocyanate groups of the polyisocyanate. Preferably, as the polyol, a hydroxyl group-remaining prepolymer obtained by reacting a polyol and a polyisocyanate having a total number of isocyanate groups smaller than the total number of hydroxyl groups of the polyol is preferably used. In this case, the above polyisocyanate can be used as the polyisocyanate, and the above polyol can be used as the polyol. By using a prepolymer, the compatibility at the time of mixing can be improved as compared with the case where the polyisocyanate and the polyol are mixed alone.

  The isocyanate group-remaining prepolymer comprises the polyol component and the polyisocyanate component so that the ratio X / Y of the hydroxyl group equivalent X in the polyol component and the isocyanate group equivalent Y in the polyisocyanate component is 3 to 20. It is preferable that it is obtained by reacting. When the isocyanate group-remaining prepolymer is produced, if the ratio X / Y is less than 3, the molecular weight of the prepolymer is increased and the viscosity becomes high and difficult to handle. If the ratio X / Y is greater than 20, the prepolymer It is almost impossible to obtain the effect of conversion.

  Moreover, it is preferable that the said hydroxyl group residual prepolymer is obtained by making the said polyol component and the said polyisocyanate component react so that ratio X / Y may be 0.05-0.3. When preparing the hydroxyl group-remaining prepolymer, if the ratio X / Y is larger than 0.3, there is a problem that the molecular weight of the prepolymer becomes large and the viscosity becomes high and difficult to handle. If the ratio X / Y is smaller than 0.05, The prepolymerization effect is hardly obtained.

  The thermosetting resin composition according to the present invention is a two-component thermosetting resin comprising a liquid A containing polyisocyanate and a quaternary phosphonium salt, and a liquid B containing a polyol and a compound having an epoxy group. A composition is preferred. Here, the “two-component thermosetting resin composition” is composed of, for example, at least two compositions such as Component A and Component B, and these can be reacted to obtain a cured product. is there. Storage stability can be further improved by using a two-component thermosetting resin composition.

  The synthesis of the prepolymer can be shortened by adding a catalyst, but it is preferable to carry out the reaction at room temperature or in the absence of a catalyst in order to avoid coloring.

  The mixing ratio of the polyol and the polyisocyanate is preferably mixed so that the ratio of hydroxyl group equivalent / isocyanate group equivalent is 0.7 to 1.3, and is mixed so that the ratio is 0.8 to 1.1. More preferred. When this ratio deviates from 0.7 to 1.3, the heat resistance, optical properties, and mechanical properties of the cured product tend to deteriorate.

  In addition to the above components, an antioxidant, a light stabilizer, an ultraviolet absorber, an inorganic filler, an organic filler, a coupling agent, a polymerization inhibitor, and the like are added to the thermosetting resin composition. Can do. Moreover, a mold release agent, a plasticizer, an antistatic agent, a flame retardant, etc. may be added from the viewpoint of moldability. These may be used singly or in combination of two or more.

  As the antioxidant, a hindered phenolic antioxidant may be used, and particularly [2- {3- (3-tert-butyl-4-hydroxy-5-methyl] because of high light resistance and heat-resistant coloring property. Phenyl) propionyl} -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane is preferably used.

  It is preferable that the compounding quantity of antioxidant is 0.05-5 mass% with respect to the total mass of a resin composition, respectively, and it is preferable that it is 0.05-0.3 mass%. When the content is less than 0.05% by mass, the effect as an antioxidant is not observed. On the other hand, when the content exceeds 5% by mass, there are problems such as solubility and precipitation during curing.

  As a mold release agent, in order to increase the mold release property of a molded product from a mold, a polysiloxane type, polyethylene type, fluorine type, fatty acid ester type, higher fatty acid salt type mold release agent can be added, In particular, fatty acid esters and higher fatty acid salt release agents are preferred.

  It is preferable that the compounding quantity of a mold release agent is 0.01-5 mass% with respect to the total mass of a resin composition, and it is preferable that it is 0.01-2 mass%. When the blending amount is less than 0.01% by mass, the effect as a mold release agent cannot be obtained.

  The method for producing a cured product using the thermosetting resin composition according to the present invention is not particularly limited. For example, the thermosetting resin composition prepared and homogenized is cast, potted, or reaction-injected. It is preferable to obtain a cured product by heat-curing by a molding method. Also in the case of the two-component type, it is preferable to obtain a cured product similarly after mixing and homogenizing the two components.

  These resin composition preparation methods and stirring methods include methods such as rotational stirring and ultrasonic dispersion, and it is necessary that the resin composition be uniform. In addition, before casting, potting, reaction injection, and molding of the resin mixture, the resin mixture is evacuated in order to remove bubbles generated during the preparation and mixing, and carbon dioxide generated by the reaction of isocyanate and moisture in the air. It is desirable to degas.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Example 1
Polycaprolactone triol having a weight average molecular weight of 300 and a hydroxyl value of 540 mg KOH / g as a polyol (B1: manufactured by Daicel Chemical Industries, trade name “Placcel 303”) is used as a compound having an epoxy group. 2.4 parts by mass of 3-epoxypropyl) isocyanurate (C1: Nissan Chemical, trade name “TEPIC-S”) was heated and stirred at 80 ° C. to dissolve. After cooling to room temperature, 47.0 parts by mass of 1,3-bis (isocyanatomethyl) cyclohexane (A1: Mitsui Takeda Chemicals, trade name “Takenate 600”) is added as a polyisocyanate, followed by stirring and ultrasonic dispersion treatment Thus, a uniform transparent mixed solution was obtained. Further, 0.1 part by mass of tetra-n-butylphosphonium o, o-diethylphosphodithionate (D1: Nippon Chemical Industry Co., Ltd., trade name “Hishicolin PX-4ET”) is added as a quaternary phosphonium salt, and thermosetting is performed. A functional resin composition was obtained.

(Example 2)
Similarly, B1 as a polyol and C1 as a compound having an epoxy group in 51.2 parts by mass and 1.0 part by mass were dissolved by heating and stirring at 80 ° C. After cooling to room temperature, A1, 47.7 parts by weight as polyisocyanate was added and stirred and subjected to ultrasonic dispersion treatment to obtain a uniform transparent mixed solution. Furthermore, D1, 0.05 mass part was added as a quaternary phosphonium salt, and the thermosetting resin composition was obtained.

(Example 3)
Similarly, B1 as polyol and C1, 2.4 parts by mass as compounds having an epoxy group at 49.0 parts by mass were heated and stirred at 80 ° C. to dissolve. After cooling to room temperature, norbornene diisocyanate (2,5- (2,6) bisisocyanatomethyl [2,2,1] heptane) (A2: manufactured by Mitsui Takeda Chemical Co., Ltd., trade name “Cosmonate NBDI” as polyisocyanate) 48.5 parts by mass were added and stirred and subjected to ultrasonic dispersion treatment to obtain a uniform transparent mixed solution. Furthermore, D1, 0.1 mass part was added as a quaternary phosphonium salt, and the thermosetting resin composition was obtained.

Example 4
Similarly, B1, 17.8 parts by weight as a polyol, 17.8 parts by weight of trimethylolpropane (B2: manufactured by Perstorp, trade name “TMP”), 80 parts of C1, 2.4 parts by weight as a compound having an epoxy group It was heated and stirred at 0 ° C. to dissolve. After cooling to room temperature, 21.3 parts by mass of A1, 32.6 parts by mass as polyisocyanate, and 29.3 parts by mass of 4-4′methylenebis (cyclohexyl isocyanate (A3: Sumitomo Bayer Urethane Co., Ltd., trade name “Desmodur W”) were added. The mixture was stirred and subjected to ultrasonic treatment to obtain a uniform transparent mixed solution, and D1 and 0.1 part by mass were added as a quaternary phosphonium salt to obtain a thermosetting resin composition.

(Example 5)
Similarly, 2.4 parts by mass of B1 as a polyol and bisphenol A diglycidyl ether (C2: made by Japan Epoxy Resin, trade name “Epicoat 828”) as a compound having an epoxy group at 49.0 parts by mass is dissolved by stirring. It was. Thereafter, A2 and 48.5 parts by mass were added as polyisocyanate, followed by stirring and ultrasonic dispersion treatment to obtain a uniform transparent mixed solution. Furthermore, D1, 0.1 mass part was added as a quaternary phosphonium salt, and the thermosetting resin composition was obtained.

(Example 6)
Similarly, B1 as polyol and C1, 2.4 parts by mass as compounds having an epoxy group at 49.0 parts by mass were heated and stirred at 80 ° C. to dissolve. After cooling to room temperature, A2, 48.5 parts by mass as polyisocyanate was added and stirred and subjected to ultrasonic dispersion treatment to obtain a uniform transparent mixed solution. Furthermore, 0.1 part by mass of methyltributylphosphonium dimethyl phosphate (D2: Nippon Chemical Industry Co., Ltd., trade name “Hishicolin PX-4MP”) was added as a quaternary phosphonium salt to obtain a thermosetting resin composition.

(Example 7)
B1 and 5.0 parts by mass were reacted with A1 and 41.9 parts by mass at 80 ° C. for 4 hours to obtain 46.9 parts by mass of an isocyanate group-remaining prepolymer (A4). On the other hand, B1 and 46.6 parts by mass were reacted with A1 and 4.7 parts by mass at 80 ° C. for 4 hours to obtain 51.3 parts by mass of a hydroxyl group-retaining prepolymer (B3). D1 and 0.1 part by mass as a quaternary phosphonium salt were added to the isocyanate group residual prepolymer (liquid A). Moreover, C1, 2.5 mass parts as a compound which has an epoxy group in a hydroxyl-residual prepolymer was dissolved by heating and stirring at 80 degreeC (B liquid). A two-component thermosetting resin composition was obtained with the above-described A solution and B solution.

(Comparative Example 1)
In the same manner as in Example 1, B1, 51.8 parts by mass as polyol and A1, 48.2 parts by mass as polyisocyanate were added and stirred and subjected to ultrasonic dispersion treatment to obtain a uniform transparent thermosetting resin composition. It was.

(Comparative Example 2)
Similarly, B1, 51.8 parts by mass as polyol and A2, 49.7 parts by mass as polyisocyanate were added and stirred and subjected to ultrasonic dispersion treatment to obtain a uniform transparent thermosetting resin composition.

(Comparative Example 3)
Similarly, C1,2.4 mass parts as a compound which has an epoxy group in B1 and 50.5 mass parts as a polyol was heated and stirred at 80 degreeC, and was dissolved. After cooling to room temperature, A1, 47.1 parts by weight as polyisocyanate was added and stirred and subjected to ultrasonic dispersion treatment to obtain a uniform and transparent thermosetting resin composition.

(Comparative Example 4)
Similarly, B1, 51.7 parts by mass as a polyol, A1, 48.2 parts by mass as polyisocyanate, and D1, 0.1 parts by mass as a quaternary phosphonium salt were added to obtain a thermosetting resin composition.

(Comparative Example 5)
Similarly, B1 as polyol and C1, 2.4 parts by mass as compounds having an epoxy group at 49.0 parts by mass were heated and stirred at 80 ° C. to dissolve. After cooling to room temperature, A2, 49.0 parts by mass as polyisocyanate was added and stirred and subjected to ultrasonic dispersion treatment to obtain a uniform transparent mixed solution. Furthermore, 0.1 part by mass of 2-ethyl-4-methylimidazole (E: manufactured by Wako Pure Chemical Industries, Ltd.), which is an imidazole generally known as an accelerator for the ring-opening reaction of epoxy, is added, and a thermosetting resin composition is added. Obtained.

  Tables 1 and 2 show the composition of each thermosetting resin composition and the gelation time at 165 ° C. for each example and comparative example. In addition, the compounding quantity in Table 1 and Table 2 shows a mass part.

  In Tables 1 and 2, A1 is 1,3-bis (isocyanatomethyl) cyclohexane, A2 is 2,5- (2,6) bisisocyanatomethyl [2,2,1] heptane, and A3 is 4,4 '-Methylenebis (cyclohexyl isocyanate, A4 is an isocyanate group residual prepolymer, B1 is a polycaprolactone triol, B2 is trimethylolpropane, B3 is a hydroxyl group residual prepolymer, C1 is tris (2,3-epoxypropyl) isocyanurate, C2 is Bisphenol A diglycidyl ether, D1 is tetra-n-butylphosphonium o, o-diethylphosphodithionate, D2 is methyltributylphosphonium dimethyl phosphate, E is imidazole known to promote ring-opening of epoxy groups Indicates -4-methylimidazole

(Measurement of gelation time)
The measuring method of gelation time is the time until tack is eliminated by gelation while dropping the resin compositions of Examples 1 to 7 and Comparative Examples 1 to 5 on a hot plate at 165 ° C. and mixing with a stirring bar. Was measured.

  In Comparative Examples 1 and 2 that do not contain an epoxy group-containing compound and a quaternary phosphonium salt, the gelation time is long. Similarly, in Comparative Examples 3 and 4 that contain only one of an epoxy group-containing compound or a quaternary phosphonium salt, The gelation time was long. Furthermore, as shown in Comparative Example 5, even when imidazole was allowed to coexist in the epoxy group-containing compound, the gelation time was not shortened.

  On the other hand, in Examples 1 to 7, although the polyisocyanate species, polyol species, epoxy group-containing compound species, quaternary phosphonium species, and the addition amount thereof, a slight difference is observed in the gelation time. It was confirmed that the gelation time was significantly shorter than ˜5 and the urethanization reaction was promoted.

Claims (6)

A thermosetting resin composition used for casting, potting or reaction injection molding,
Polyisocyanate,
Polyols,
A compound having an epoxy group;
A quaternary phosphonium salt,
The quaternary phosphonium salt has a hydrogen atom bonded to a carbon atom adjacent to a phosphorus atom;
Wherein the poly isocyanates, seen containing a urethane prepolymer having an isocyanate Lee group,
The compounding quantity of the compound which has the said epoxy group is 0.1-10 mass% with respect to the total mass of the said resin composition,
The thermosetting resin composition whose compounding quantity of the said quaternary phosphonium salt is 0.01-2 mass% with respect to the total mass of the said resin composition . A thermosetting resin composition used for casting, potting or reaction injection molding,
Polyisocyanate,
Polyols,
A compound having an epoxy group;
A quaternary phosphonium salt,
The quaternary phosphonium salt has a hydrogen atom bonded to a carbon atom adjacent to a phosphorus atom;
Wherein the polyol is seen containing a urethane prepolymer having a water group,
The compounding quantity of the compound which has the said epoxy group is 0.1-10 mass% with respect to the total mass of the said resin composition,
The thermosetting resin composition whose compounding quantity of the said quaternary phosphonium salt is 0.01-2 mass% with respect to the total mass of the said resin composition .   The thermosetting resin composition according to claim 1, wherein the quaternary phosphonium salt is a tetraalkylphosphonium salt. Liquid A containing the polyisocyanate and the quaternary phosphonium salt;
The thermosetting resin composition according to any one of claims 1 to 3, wherein the thermosetting resin composition is a two-component thermosetting resin composition comprising the polyol and the B liquid containing the epoxy group-containing compound.   The said polyisocyanate is a thermosetting resin composition as described in any one of Claims 1-4 containing bifunctional or more alicyclic polyisocyanate.   The bifunctional or higher alicyclic polyisocyanates include 4,4′-methylenebis (cyclohexyl isocyanate), isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, and 2,5- (2,6) bisisocyanate. The thermosetting resin composition according to claim 5, which is at least one selected from the group consisting of netomethyl [2,2,1] heptane.