JP2002037835A - Polyisocyanate composition with excellent thixotropic properties - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing material excellent in thixotropy using a polyisocyanate composition having a low urethane bond in a resin, a low viscosity and having no low molecular weight compound causing a reduction in surface tack. provide. A polyisocyanate composition comprising A) an isocyanate-terminated prepolymer obtained from an aliphatic and / or alicyclic diisocyanate monomer and B) a thixotropic agent, and a sealing material using the same. .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel polyisocyanate composition useful as a sealing material for buildings and automobiles, and a sealing material using the same.

[0002]

2. Description of the Related Art Moisture-curable high molecular weight compounds having terminal isocyanate groups are widely used as sealing materials for construction and automobiles. The isocyanate group reacts and cures with moisture in the air to exhibit physical properties as a sealing material. There are many proposals on this. Regarding building sealing materials, Japanese Unexamined Patent Publication (Kokai) No. 3-111448 discloses an average molecular weight of 3,
000 and 5,000 polypropylene glycol and 4,4'-diphenylmethane diisocyanate (hereinafter referred to as M
JP) JP-A-4-370146 discloses polyoxypropylene glycol having an average molecular weight of 3,000, polyoxypropylene triol having an average molecular weight of 300 and MDI, and JP-A-6-080755 discloses an average molecular weight of 3, 2,000 polyoxypropylene glycol, polyoxypropylene triol having an average molecular weight of 3,000, and xylylene diisocyanate were prepared by the method described in JP-A-6-2.
No. 56499 discloses a polyalkylene ether triol having an average molecular weight of 7,000, a polyalkylene triol having an average molecular weight of 5,000 and MDI are disclosed in JP-A-3-215.
Japanese Patent Application Laid-Open No. 554/554 discloses a reaction between a polyether triol having a molecular weight of 3,000 and MDI, and Japanese Patent Application Laid-Open No. Hei 5-209165 discloses a reaction between a polyoxypropylene ether diol having a molecular weight of 4,000 and a polyoxypropylene triol having a molecular weight of 10,000 with tolylene diisocyanate. The isocyanate group-terminated high molecular weight product is disclosed.

[0003] Urethane-based sealing materials for construction are desired to have no surface tack, to be improved in weather resistance, stain resistance, low modulus, high curability, low viscosity, and foam resistance. However, the above proposal has its limitations. All of these are
In the reaction between the polyol and the diisocyanate monomer, the reaction is performed in a state where the equivalents of the hydroxyl group and the isocyanate group are relatively close. Such reaction conditions are effective in improving the molecular weight for maintaining the physical properties of the cured sealing material, and indeed, a high molecular weight substance is generated by the reaction. However, since such a method basically has the following problems, it is dealt with by various prescriptions. Therefore, there were many restrictions.

[0004] a) The fact that the molecular weight is increased by the urethane bond results in an increase in viscosity due to the urethane bond and an increase in the modulus of the cured resin. Therefore, plasticizers, solvents and the like are used, which cause contamination. B) The polyoxyalkylene polyol contains a small amount of monoalcohol. In such a reaction in which the equivalents of the hydroxyl group and the isocyanate group are relatively close, a low molecular weight in which the monoalcohol is added to both ends of the diisocyanate monomer is used. The compound forms, which is not reactive,
It causes surface tack.

(C) The high molecular weight product obtained under such conditions has unreacted diisocyanate monomer remaining,
Reacts with moisture and easily foams. Therefore, the present inventors first,
A high-molecular-weight polyol and a diisocyanate monomer are reacted in a large excess of a diisocyanate monomer state, and a sealing material using a specific polyisocyanate product from which an unreacted diisocyanate monomer is removed after the reaction has been proposed (JP-A-10-168155, WO 99/5296).
0). This proposal fulfilled the above task,
Further, the present inventors have conducted studies in pursuit of thixotropic properties for improving workability.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a moisture-curable sealing material using a low-viscosity polyisocyanate composition having a small amount of urethane bonds in a resin, particularly having excellent thixotropic properties.

[0007]

Means for Solving the Problems The present inventors have found that the above object can be achieved by adding a thixotropic agent to an isocyanate-terminated prepolymer, and have accomplished the present invention. That is, the present invention is as follows.

[0008] A polyisocyanate composition comprising: 1.1) an isocyanate-terminated prepolymer derived from an aliphatic and / or alicyclic diisocyanate monomer; and 2) a thixotropic agent. 2. The thixotropic agent is one selected from hydrogenated castor oil, amide wax, aluminum stearate, calcium stearate, zinc stearate, fine powdered silica, organic bentonite, bentone, silicic anhydride, silicic acid derivative, urea derivative, and Aerosil. Or two or more types. The polyisocyanate composition according to the above.

3. Isocyanate-terminated prepolymer,
It is obtained by reacting an aliphatic and / or alicyclic diisocyanate with a polyol having a number average molecular weight of 3,000 to 30,000 and an average number of hydroxyl groups of 2 to 3, and satisfies all the following conditions. Or 2. The polyisocyanate composition according to the above. 1) Isocyanate average functional group number 2 to 4 2) Number average molecular weight 3,000 to 30,000 3) Viscosity 1,000 to 100,000 mPa · s /
25 ° C 4) Isocyanate group concentration 0.05 to 10% by weight 5) Diisocyanate monomer concentration 0 to 5% by weight

[0010] 4. 2. the isocyanate-terminated prepolymer contains allophanate linkages; The polyisocyanate composition according to the above. 5. 3. The allophanate binding ratio is 0.05 to 0.4. The polyisocyanate composition according to the above. 6. 4. It is a moisture-curing type. The polyisocyanate composition according to the above. 7.1. From 6. A sealing material comprising the polyisocyanate composition according to any one of the above.

Hereinafter, the present invention will be described in detail. The isocyanate-terminated prepolymer used in the present invention is not particularly limited, and examples thereof include those obtained by reacting a diisocyanate monomer and a polyol. Representative examples thereof are shown below. The diisocyanate monomer used in the present invention is aliphatic and / or alicyclic.

The aliphatic and / or alicyclic diisocyanate monomer preferably has 4 to 30 carbon atoms, for example, tetramethylene-1,4-diisocyanate, pentamethylene-1,5-diisocyanate, hexamethylene diisocyanate. 2,2,4-trimethyl-hexamethylene-1,6-diisocyanate, lysine diisocyanate, isophorone diisocyanate,
Examples thereof include 1,3-bis (isocyanatomethyl) -cyclohexane and 4,4′-dicyclohexylmethane diisocyanate. Among them, hexamethylene diisocyanate (hereinafter, referred to as HMDI) and isophorone diisocyanate (hereinafter, referred to as IPDI) are preferable from the viewpoint of weather resistance and industrial availability, and they may be used alone or in combination. The average number of hydroxyl functional groups of the polyol used in the present invention is preferably 2 to 3. If it is less than 2, the curability is not always sufficient, and if it exceeds 3, the cured resin properties tend to decrease. Polyols include acryl, polyester, polybutadiene, polyether and the like, and polyether polyol is preferable.

The production of polyether polyols is carried out by specifically preparing polyhydric alcohols, polyhydric phenols, polyamines, alkanolamines, etc., for example, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol,
4-butanediol, 1,6-hexanediol, dihydric alcohols such as bisphenol A, glycerin, trihydric alcohols such as trimethylolpropane, and diamines such as ethylenediamine alone or in mixtures, for example, lithium, sodium, potassium, etc. Strongly basic catalysts such as hydroxides, alcoholates, and alkylamines, metal porphyrins, complex metal cyanide complexes, complexes of metals with chelating agents of tridentate or higher, and complex metal complexes such as zinc hexacyanocobaltate complex It is obtained by adding an alkylene oxide alone or a mixture such as ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide and styrene oxide. The preferred alkylene oxide is propylene oxide.

The molecular weight of the polyol is from 3,000 to 30,
000 is preferable, and 5,000 to 2 is more preferable.
000, particularly preferably from 6,000 to 1
5,000. If the molecular weight is less than 3,000, the cured resin properties such as elongation tend to decrease, and
If it is more than 00, the curability tends to be insufficient. The diisocyanate monomer and the polyol are preferably reacted at an isocyanate group / hydroxyl group equivalent ratio of 5/1 to 100/1. If the equivalent ratio is less than 5/1, the viscosity of the reaction solution increases, and if it exceeds 100/1, the yield tends to decrease.

In the reaction between the diisocyanate monomer and the polyol, a solvent may be used, but in such a case, a solvent inert to the isocyanate should be used. The reaction temperature is preferably from 60 to 200 ° C, more preferably from 120 to 180 ° C. If the reaction temperature is lower than 60 ° C., the reaction rate is low, so that the productivity is lowered and allophanate bonds are hardly generated. If the reaction temperature is higher than 200 ° C., side reactions such as coloring may occur.

In the reaction, a catalyst can be used. The catalyst is generally preferably basic. 1) For example, a quaternary amine compound such as a tetraalkylammonium hydroxide or an organic weak acid group such as acetic acid or capric acid, 2) a trioctylamine, for example. Tertiary such as 1,4-diazabicyclo (2,2,2) octane, 1,8-diazabicyclo (5,4,0) undecene-7 and 1,5-diazabicyclo (4,3,0) nonene-5 Amine-based compounds, 3) Catalysts that promote allophanation reactions such as metal organic weak acid salts such as zinc, tin, lead, and iron, such as acetylacetone metal salts such as zinc, are also effective.

The catalyst concentration is usually selected from the range of 10 ppm to 1.0% with respect to the isocyanate compound. It is preferable that at least a part of the urethane bond present in the reaction solution is converted to an allophanate bond. The allophanate bond ratio is defined as allophanate bond / (urethane bond + allophanate bond), and the allophanate bond ratio is preferably 0.05 to 0.4, and more preferably 0.2 to 0.4. If the value is less than 0.05, good physical properties such as curability may not be obtained, and if it exceeds 0.4, a sufficiently low modulus may not be obtained. In this case, the reaction may be stopped halfway so that the allophanate binding ratio falls within the above range, or one having a large allophanate binding ratio and one having a small allophanate binding ratio may be mixed after purification.

After the reaction, unreacted diisocyanate monomer and solvent are removed by a method such as thin film distillation or extraction to obtain an isocyanate-terminated prepolymer. The diisocyanate monomer concentration in the isocyanate-terminated prepolymer is preferably 5% or less, more preferably 1%.
Or less, more preferably 0.5% or less. If the diisocyanate monomer concentration exceeds 5%, foaming is likely to occur when the isocyanate-terminated prepolymer is cured.

The isocyanate-terminated prepolymer thus obtained has an isocyanate group concentration of preferably 0.05 to 10% by weight, more preferably 0.5 to 5% by weight, and a viscosity at 25 ° C. Is preferably 1,00
0-100,000 mPa · s, more preferably 3,0
00 to 50,000 mPa · s. If the isocyanate group concentration is less than 0.05% by weight, sufficient curability cannot be obtained, and if it exceeds 10% by weight, a sufficiently low modulus tends not to be obtained. On the other hand, if the viscosity is less than 1,000, it is difficult to obtain sufficient thixotropic properties. If the viscosity is more than 100,000, the viscosity becomes high and the workability tends to deteriorate.

As the thixotropic agent in the present invention, various thixotropic agents usually added for imparting thixotropic properties can be used. As the thixotropic agent, hydrogenated castor oil, amide wax, aluminum stearate, calcium stearate, zinc stearate, fine powdered silica, organic bentonite, bentone, silicic anhydride, silicic acid derivative, urea derivative, Aerosil and the like are known. Therefore, any commercially available substance can be used in the present invention. Further, a combination of two or more kinds selected from these can also be used. Particularly preferred are hydrogenated castor oil, finely divided silica and Aerosil.

In the present invention, it is essential to add one or more of thixotropic agents to the isocyanate-terminated prepolymer. The thixotropic agent is preferably used in an amount of 0.0
It is used in a proportion of 01 to 50 parts by weight, more preferably 0.01 to 20 parts by weight. If the amount is less than 0.001 part by weight, the effect tends to be small, and if it is more than 50 parts by weight, workability may be adversely affected.

The polyisocyanate composition of the present invention contains a stabilizer, an inert solvent, a plasticizer, a filler, a photocurable substance, a curing catalyst, titanium oxide, an adhesion promoter, a dye, a pigment, a flame retardant and the like. Then, it becomes a moisture-curable sealing material. Examples of the stabilizer include a benzotriazole-based ultraviolet absorber, a phosphite-based antioxidant, an organic sulfur-based antioxidant, a hindered phenol-based antioxidant, and a hindered amine light stabilizer.

The inert solvent is a solvent having no functional group which reacts with an isocyanate group, for example, an aromatic hydrocarbon such as toluene and xylene, an aliphatic hydrocarbon such as hexane, heptane and octane; There are petroleum solvents such as gasoline, kerosene and process oil, esters, ketones, ether esters and the like. As a plasticizer,
For example, dibutyl phthalate, phthalic acid derivatives such as dioctyl phthalate, benzoic acid, trimellitic acid, pyromellitic acid, adipic acid, sebacic acid, fumaric acid, maleic acid, itaconic acid, derivatives such as citric acid, polyester, polyether, There is an epoxy type and the like, and as a polymer plasticizer, for example, polyester, polyether, polystyrene, poly-α-methylstyrene, polybutadiene, alkyd resin, polychloroprene, and butadiene-acrylonitrile copolymer, ethylene glycol-propylene glycol Copolymers, polyoxyalkylene monoethers, natural oils, epoxidized natural oils, paraffinic polyolefin waxes and the like.

As the filler, for example, a silicic acid derivative,
Examples include talc, metal powder, calcium carbonate, clay, and carbon black. Photo-curable substances are light-cured
Various substances such as organic monomers, oligomers, resins and compositions containing these are known as such substances, and any commercially available substance is used in the present invention. can do. For example, unsaturated acrylic compounds, polyvinyl cinnamates, azide resins and the like can be mentioned.

Examples of the curing catalyst include organic tin compounds such as dibutyltin dilaurate and dioctyltin dilaurate, organic zinc compounds such as zinc octylate, triethyleneamine, triethylenediamine, laurylamine, morpholine, diazabicyclocycloun, and the like. There are amine compounds such as decene, diazabicyclooctane and the like, which may be used in combination. Specific examples of the titanium oxide include, for example, Typek R-820, Typek R-830, Typek R-930, Typek R-850, and Typek R-8.
55, Taipe CR-57, Taipe CR-80,
Taipe CR-90, Taipe CR-93, Taipe CR-95, Taipe CR-97, Taipe C
R-85 (all of which are trade names manufactured by Ishihara Sangyo Co., Ltd.) and the like.

Examples of the adhesion-imparting agent include 3-glycidylpropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane. Examples include silane coupling agents such as silane.

The polyisocyanate composition of the present invention can also be used as a two-part sealing material. When used as a two-part sealing material, a polyvalent active hydrogen compound is added in addition to the additives. Examples of the polyvalent active hydrogen compound include polyols and polythiols. Polyvalent active hydrogen compounds that are commonly used for urethane-based two-pack sealing materials can be used, and examples include polyether-based, polyester-based, and acrylic-based compounds. Examples of the polyether type include, for example, an average number of hydroxyl functional groups of 2 to 3 used to obtain the isocyanate-terminated prepolymer.
And polyethers. As the acrylic resin, an acrylic polyol having an average number of hydroxyl groups of 2 to 3 in one molecule, for example, a hydroxyl-terminated telechelic polymer described in JP-A-4-132706 can be used. Further, as the fluorinated acrylic polyol, for example, it is also possible to use a fluorinated acrylic polymer or the like derived from a polymerizable monomer such as tetrafluoroethylene, trifluoroethylene, chlorotrifluoroethylene, vinyl fluoride, hexafluoropropylene, or the like. it can.

The obtained sealing material of the present invention can be used as a working joint or a non-working joint for various exterior panels for curtain walls, ceramic siding boards, ALC, concrete, etc., metal fittings and the like. Further, the polyisocyanate composition of the present invention can be used for an adhesive, a pressure-sensitive adhesive, a waterproofing material, a flooring material, a resin, an elastomer and the like in addition to a sealing material.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to the following examples. In addition, "part" represents "part by weight". The measuring method is as follows.

(Measurement of number average molecular weight)
It is a number average molecular weight based on polystyrene by gel permeation chromatography (hereinafter, referred to as GPC) measurement using the following apparatus. Equipment: Tosoh Corporation HLC-802A Carrier: Tetrahydrofuran Detection method: Differential refractometer

(Viscosity) The viscosity at a temperature of 25 ° C. was measured with an E-type viscometer “RE80R” manufactured by Toki Sangyo. (Allophanate bond ratio) FT-NMR manufactured by JEOL
Using “FT90Q”, acetone-d6 was used as a solvent, and as a result of H-NMR measurement, the peak integrated value of allophanate bond and urethane bond was calculated as
(Allophanate bond + urethane bond).

(Mixing) The mixing of the polyisocyanate composition with various additives, fillers, and the like was performed using Twin Mix (Dalton Co., Ltd.). (Thixotropic) Thickening was represented by A / B, where A was the viscosity measured at 0.5 rpm, and B was the viscosity measured at 5 rpm.

[0033]

[Production Example 1] A four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blowing ring, and a dropping funnel was set to a nitrogen atmosphere, and 600 parts of HMDI and a divalent polyether polyol (trade name "Preminol 8000 of Asahi Glass") were used. "Number average molecular weight 8,000) 1000 parts (isocyanate group /
The hydroxyl group equivalent ratio was 28.6 / 1), and the temperature in the reactor was maintained at 160 ° C. for 3 hours with stirring in a nitrogen atmosphere. Reduce the temperature of the reaction solution and use a thin-film evaporator to remove unreacted HMDI.
Was removed. The number average molecular weight of the obtained isocyanate-terminated prepolymer (prepolymer A) is 8000, the isocyanate group concentration is 1.7%, and the viscosity is 6000 mPa · s.
s, allophanate bond concentration 0.60, diisocyanate monomer concentration 0.2%, and average isocyanate functional group number 3.2.

[0034]

Production Example 2 A four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blowing ring, and a dropping funnel was set to a nitrogen atmosphere, and 600 parts of HMDI and divalent polyether polyol (trade name "Preminol 8000 of Asahi Glass Co., Ltd.""Number average molecular weight 8,000) 1000 parts (isocyanate group /
The equivalent ratio of the hydroxyl group was 28.6 / 1), and the temperature in the reactor was kept at 120 ° C. for 8 hours with stirring under a nitrogen atmosphere. Reduce the temperature of the reaction solution and use a thin-film evaporator to remove unreacted HMDI.
Was removed. The obtained isocyanate-terminated prepolymer (prepolymer B) had a number average molecular weight of 8000, an isocyanate group concentration of 1.0%, and a viscosity of 6000 mPa ·
s, allophanate bond concentration 0.00, diisocyanate monomer concentration 0.2%, average isocyanate functional group number 2.0.

[0035]

[Production Example 3] Prepolymer A 100 parts, Prepolymer B
400 parts were sufficiently kneaded and dispersed. The obtained mixed isocyanate-terminated prepolymer (prepolymer C) has a number average molecular weight of 8000, an isocyanate group concentration of 1.1%, a viscosity of 6000 mPa · s, and an allophanate bond concentration of 0.1%.
12. The diisocyanate monomer concentration was 0.2%, and the average number of isocyanate functional groups was 2.1.

[0036]

Example 1 100 parts of heavy calcium carbonate (trade name "Super SS" of Maruo Calcium Co., Ltd.) was mixed in a mixer.
After drying at 120 ° C. and 133 Pa or less for 2 hours, and cooling, titanium dioxide (trade name “Taipe CR-
90 ") 20 parts, prepolymer C 100 parts, hydrogenated castor oil (Kusumoto Kasei Co., Ltd. trademark" Disparon 305 ") 1
0 parts were added, and the mixture was sufficiently kneaded and dispersed while deaerated under reduced pressure to prepare a curable composition. Table 1 shows the results.

[0037]

Example 2 70 parts of heavy calcium carbonate (trade name "Super SS" of Maruo Calcium Co., Ltd.) and light calcium carbonate (trade name of "Calfine 2" of Maruo Calcium Co., Ltd.)
00M ”) in a mixer at 120 ° C. for 2 hours at 133 Pa or less, and after cooling, 20 parts of titanium dioxide (trade name“ Taipec CR-90 ”of Ishihara Sangyo Co., Ltd.), 100 parts of prepolymer C, water Add 4 parts of castor oil (Kusumoto Kasei Co., Ltd. trademark "DISPARON 305"), knead and disperse sufficiently while degassing under reduced pressure to prepare a curable composition.
Viscosity was measured at 5 ° C. to determine thixotropic properties. Table 1 shows the results
Shown in

[0038]

Example 3 Example 3 was carried out in the same manner as in Example 1 except that the thixotropic agent and the amount shown in Table 1 were used. Table 1 shows the results.

[0039]

COMPARATIVE EXAMPLE 1 100 parts of heavy calcium carbonate (trade name "Super SS" of Maruo Calcium) was put in a mixer at 120 ° C.
After drying at 133 Pa or less for 2 hours and cooling, titanium dioxide (trade name “Taipek CR-90” of Ishihara Sangyo Co., Ltd.) 2
0 parts and 100 parts of prepolymer C were added, and kneaded and dispersed sufficiently while deaeration under reduced pressure to prepare a curable composition.
And the thixotropic properties were measured. Table 1 shows the results.

[0040]

Comparative Example 2 70 parts of heavy calcium carbonate (trade name “Super SS” of Maruo Calcium Co., Ltd.) and light calcium carbonate (trade name “Calfine 2” of Maruo Calcium Co., Ltd.)
00M ”) in a mixer at 120 ° C. for 2 hours at 133 Pa or less, and after cooling, 20 parts of titanium dioxide (trade name“ Taipek CR-90 ”of Ishihara Sangyo Co., Ltd.) and 100 parts of prepolymer C are added. Then, the mixture was sufficiently kneaded and dispersed while deaerated under reduced pressure to prepare a curable composition, and the viscosity was measured at 25 ° C. to measure thixotropic properties. Table 1 shows the results.

[0041]

[Table 1]

[0042]

The composition of the present invention, when used as a sealing material for buildings and automobiles, has a low viscosity, has no surface tack, achieves a low modulus, has high weather resistance, and has particularly excellent thixotropic properties. Most suitable as a moisture-curing sealing material.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) C08K 3/34 C08K 3/34 3/36 3/36 5/098 5/098 5/21 5/21 C08L 75/04 C08L 75/04 91/00 91/00 C09K 3/00 103 C09K 3/00 103N 3/10 3/10 A D Q F term (reference) 4H017 AA04 AA24 AA25 AA27 AA31 AA35 AC05 AC19 AE03 AE05 4J002 AE032 AE052 CK031 CK041 CK041 CK051 DE116 DJ006 DJ016 EG036 EG046 ET006 FA086 FD202 FD206 GJ02 4J034 BA03 DA01 DB04 DB05 DB07 DC02 DC42 DC50 DF01 DG02 DG03 DG04 DG05 DG08 DG18 DP02 DP18 DP19 GA02 GA06 HA01 HA02 HA07 HA11 HC02 MA01 MA01 MA03 MA01 MA03

Claims (7)

[Claims] 1. A polyisocyanate composition comprising: 1) an isocyanate-terminated prepolymer derived from an aliphatic and / or alicyclic diisocyanate monomer; and 2) a thixotropic agent. 2. Thixotropic agents are hydrogenated castor oil, amide wax, aluminum stearate, calcium stearate, zinc stearate, finely divided silica, organic bentonite, bentone, silicic anhydride, silicic acid derivatives, urea derivatives, aerosil The polyisocyanate composition according to claim 1, wherein the composition is at least one member selected from the group consisting of: 3. An isocyanate-terminated prepolymer is obtained by reacting an aliphatic and / or alicyclic diisocyanate with a polyol having a number average molecular weight of 3,000 to 30,000 and an average number of hydroxyl groups of 2 to 3, and 3. The polyisocyanate composition according to claim 1, wherein the composition satisfies the following. 1) Isocyanate average functional group number 2 to 4 2) Number average molecular weight 3,000 to 30,000 3) Viscosity 1,000 to 100,000 mPa · s /
25 ° C 4) Isocyanate group concentration 0.05 to 10% by weight 5) Diisocyanate monomer concentration 0 to 5% by weight 4. The polyisocyanate composition according to claim 3, wherein the isocyanate-terminated prepolymer contains allophanate linkages. 5. An allophanate binding ratio of 0.05 to
The polyisocyanate composition according to claim 4, wherein the composition is 0.4. 6. The polyisocyanate composition according to claim 5, wherein the composition is a moisture-curable type. 7. A sealing material comprising the polyisocyanate composition according to claim 1.