JP2002037846A - Polyisocyanate composition excellent in contamination resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealant excellent in contamination resistance and tackiness resistance having low modulus obtained from a polyisocyanate composition without adding a low molecular weight compound reducing the surface tackiness, having low viscosity and few urethane bonds in the polyisocyanate resin. SOLUTION: The polyisocyanate composition is characterized by containing A) an isocyanate terminated prepolymer obtained from aliphatic and/or alicyclic diisocyanate and B) an unsaturated compound capable of reacting with oxygen.

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,
Furthermore, the present inventors have conducted further studies in pursuit of even lower modulus and stain resistance.

[0006]

An object of the present invention is to provide a moisture-curable sealing material which uses a low-viscosity polyisocyanate composition containing a small amount of urethane bonds in a resin, and which has particularly low modulus and excellent stain resistance. Aim.

[0007]

Means for Solving the Problems The present inventors have found that the above object can be achieved by adding an unsaturated compound capable of reacting with oxygen to an isocyanate-terminated prepolymer. Reached. Unsaturated compounds that can react with oxygen are polymerized or cross-linked by oxygen in the air to become insoluble. In other words, it reacts a lot on the part that comes in contact with oxygen more, that is, on the surface of the compound, so it has no adverse effect on physical properties such as strength and elongation and durability, and has extremely effective stain resistance and tack resistance. Improve. On the other hand, surprisingly, it has been discovered that unsaturated compounds that can react with oxygen inside the sealing material, which is hard to reach oxygen in the air, contribute to low modulus without polymerizing or crosslinking. The invention has been reached.

That is, the present invention is as follows. A polyisocyanate composition comprising: 1.1) an isocyanate-terminated prepolymer derived from an aliphatic and / or alicyclic diisocyanate monomer; and 2) a compound capable of reacting with oxygen. 2. The unsaturated compound capable of reacting with oxygen is at least one selected from the group consisting of a diene polymer, a drying oil and a modified product thereof. 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, and more preferably. Is HMDI. 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 tetraalkylammonium hydroxide or an organic weak acid group such as acetic acid or capric acid. 2) Trioctyl. Amines 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; Catalysts which promote the allophanate-forming reaction of metal organic weak salts such as zinc, tin, lead and iron, such as acetylacetone metal salts such as zinc, etc. 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. In addition, the viscosity is 1,000 mPa.
If it is less than s, it is difficult to obtain sufficient thixotropic properties,
If it exceeds 000 mPa · s, the viscosity increases and the workability tends to deteriorate.

The unsaturated compound capable of reacting with oxygen in the air which can be used in the present invention generally includes an air oxidation cured material having an unsaturated group in the molecule which is polymerized by oxygen in the air. Specifically, for example, tung oil,
Dry oils such as linseed oil, various alkyd resins obtained by modifying the compound, acrylic polymers modified with drying oil, epoxy resins, silicone resins, 1,2-polybutadiene, 1,4-polybutadiene, Examples thereof include polymers and copolymers of C _{5 to} C ₈ dienes, and various modified products of the polymer and copolymer (maleated modified products, boiled oil modified products, and the like). Among them, liquid substances (liquid diene polymers) and modified products thereof among tung oil, linseed oil and diene polymers are preferable.

Specific examples of the liquid diene polymer include butadiene, chloroprene, isoprene, and the like.
A liquid polymer obtained by polymerizing or copolymerizing a diene compound such as 1,3-pentadiene, or a monomer such as acrylonitrile or styrene having a copolymer with these diene compounds is mainly composed of a diene compound. Polymers such as NBS and SBR obtained by copolymerization as well as various modified products thereof (maleic compounds, boiled oil modified products, etc.). Of these liquid diene polymers, liquid polybutadiene is preferred.

The unsaturated compounds capable of reacting with oxygen in the air may be used alone or in combination of two or more. Also,
The effect may be enhanced when an unsaturated compound capable of reacting with oxygen in the air is used in combination with a catalyst or a metal dryer that promotes the oxidative curing reaction. As these catalysts and metal dryers, for example, cobalt naphthenate, lead naphthenate, zirconium naphthenate, cobalt octylate,
Examples thereof include metal salts such as zirconium octylate and amine compounds.

According to the present invention, the unsaturated compound capable of reacting with oxygen in the air is used in an amount of preferably 0.001 to 30 parts by weight, more preferably 0.01 to 20 parts by weight, based on 100 parts by weight of the isocyanate-terminated prepolymer. Use in proportions. If the amount is less than 0.001 part by weight, the effect tends to be small, and if it is more than 30 parts by weight, physical properties may be adversely affected. In the polyisocyanate composition of the present invention, a stabilizer, an inert solvent, a plasticizer, a filler, a photocurable substance, a thickener or a thixotropic agent, a curing catalyst, titanium oxide, an adhesion agent, a dye, and a pigment , A flame-retardant, etc., to form a moisture-curable sealing material.

Examples of the stabilizer include a benzotriazole ultraviolet absorber, a phosphite antioxidant, an organic sulfur antioxidant, a hindered phenol antioxidant, a hindered amine light stabilizer and the like. An inert solvent is a solvent having no functional group that reacts with an isocyanate group, for example, an aromatic hydrocarbon such as toluene and xylene, an aliphatic hydrocarbon such as hexane, heptane, and octane, gasoline, and kerosene. And petroleum solvents such as process oils, esters, ketones, ether esters and the like.

Examples of the plasticizer include phthalic acid derivatives such as dibutyl phthalate and dioctyl phthalate, benzoic acid, trimellitic acid, pyromellitic acid, adipic acid, and the like.
Derivatives such as sebacic acid, fumaric acid, maleic acid, itaconic acid, and citric acid, polyesters, polyethers, epoxy-based resins, and the like. Examples of the polymer plasticizer include polyester, polyether, polystyrene, and poly-α-methyl. There are styrene, polybutadiene, alkyd resin, polychloroprene, butadiene-acrylonitrile copolymer, ethylene glycol-propylene glycol copolymer, polyoxyalkylene monoether, natural oil, epoxidized natural oil, paraffin polyolefin wax and the like.

As the filler, for example, silicic acid derivatives,
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 thixotropic agent include hydrogenated castor oil, amide wax, aluminum stearate,
Examples include calcium stearate, zinc stearate, finely divided silica, organic bentonite, bentone, silicic anhydride, silicic acid derivatives, urea derivatives, and Aerosil. As the curing catalyst, for example, organic tin compounds such as dibutyltin dilaurate, dioctyltin dilaurate, organic zinc compounds such as zinc octylate, triethyleneamine, triethylenediamine, laurylamine, morpholine, diazabicyclocycloundecene, dia There are amine compounds such as zabicyclooctane and the like, which may be used in combination.

As the titanium oxide, specifically, for example,
Taipa R-820, Taipa R-830, Taipa R-930, Taipa R-850, Taipa R
-855, Taipe CR-57, Taipe CR-8
0, Taipe CR-90, Taipe CR-93, Taipe CR-95, Taipe CR-97, Taipe CR-85 (all of which are trade names of Ishihara Sangyo Co., Ltd.) and the like. As the adhesion imparting agent, for example,
3-glycidylpropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, γ
-Silane coupling agents such as mercaptopropyltrimethoxysilane.

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 for curtain walls, ceramic siding boards, ALC, various exterior panels for concrete and the like, metal fittings and the like, and a non-working joint. 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.

[0031]

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) The number average molecular weight was measured by gel permeation chromatography (hereinafter, GP) using the following apparatus.
C) is the number average molecular weight based on polystyrene measured. 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 carried out using Twin Mix (Dalton Co., Ltd.).

(Contamination test) Using a siding board (trademark “Kanbe” of Toray Grasal Co., Ltd.), a width of 12 m
m, a depth of 10 mm, a groove having a length of 300 mm, and a compound of the polyisocyanate composition is applied there,
After curing for 3 weeks at 20 ° C. and a humidity of 60 RH%, an exposure test was performed. The evaluation was performed by a visual test, and represented by three levels of の, Δ, and × in the order of good, good, and bad, respectively.

(Tackiness) Using a siding board (trade name “Kanbe” of Toray Grasal Co., Ltd.), a width of 12 m
m, a depth of 10 mm, a groove having a length of 300 mm, and a compound of the polyisocyanate composition is applied there,
After curing at 20 ° C. and a humidity of 60 RH% for 3 weeks, a tackiness test was performed. The evaluation was performed by a finger touch test, and was expressed in three stages of ○, Δ, and × in the order of good, good, and bad, respectively.

(Tensile test) A compound of the polyisocyanate composition was poured into a mold so as to have a thickness of 1 mm, and was left at 20 ° C. and a humidity of 60 RH% for 3 weeks.
0 mm, cut into a test piece of 50 mm length, pulling speed 50 mm / min, distance between chucks at the start of measurement 10 mm,
A tensile test was performed with a cross-sectional area of 10 mm2 at the start of the measurement.

[0038]

[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.

The temperature of the reaction solution was lowered, and unreacted HMDI was removed using a thin film evaporator. The number average molecular weight of the obtained isocyanate-terminated prepolymer (prepolymer A) is 8
000, isocyanate group concentration 1.7%, viscosity 60
00mPa · s, allophanate bond concentration 0.60, diisocyanate monomer concentration 0.2%, and average isocyanate functional group number 3.2.

[0040]

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.

The temperature of the reaction solution was lowered, and unreacted HMDI was removed using a thin film evaporator. The number average molecular weight of the obtained isocyanate-terminated prepolymer (prepolymer B) is 8
000, isocyanate group concentration 1.0%, viscosity 60
00 mPa · s, allophanate bond concentration 0.00, diisocyanate monomer concentration 0.2%, and average isocyanate functional group number 2.0.

[0042]

[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.

[0043]

Example 1 100 parts of light calcium carbonate (trade name “Calfine 200M” of Maruo Calcium Co., Ltd.) was dried in a mixer at 120 ° C. and 133 Pa or less for 2 hours. After cooling, titanium dioxide (Ishihara Sangyo Co., Ltd.) ) Trademark (Taipaek CR-90)), 20 parts of prepolymer C, linseed oil 5 as an unsaturated compound capable of reacting with oxygen in the air
Part, a benzotriazole-based ultraviolet absorber (trade name “Tinuvin 327” of Ciba Specialty Chemicals Co., Ltd.) dissolved in tetrahydrofuran at 20% by weight.
5 parts, 0.2 parts of BHT (2,6-di-tert-butyl-4-methylphenol) dissolved at 50% by weight in tetrahydrofuran, and 0.2 parts of dibutyltin dilaurate as a curing catalyst were added. Then, the mixture was sufficiently kneaded and dispersed while being degassed under reduced pressure to prepare a curable composition, and a sample for a contamination test was prepared using the curable composition.
After curing at H% for 14 days, an exposure test was performed. Table 1 shows the results
Shown in

[0044]

Example 2 Example 2 was carried out in the same manner as in Example 1 except that the unsaturated compounds capable of reacting with oxygen in the air shown in Table 1 and the amounts added were used. Table 1 shows the results.

[0045]

[Comparative Example 1] 100 parts of light calcium carbonate (trade name “Calfine 200M” of Maruo Calcium) was mixed with 1 part of a mixer.
After drying at 20 ° C. and 133 Pa or less for 2 hours, and cooling, titanium dioxide (trademark “Taipeku CR-9” of Ishihara Sangyo Co., Ltd.)
0 ") 20 parts, prepolymer C 100 parts, and" tinuvin 327 "dissolved in tetrahydrofuran at 20% by weight.
Of BHT dissolved in tetrahydrofuran at 50% by weight, and 0.2 parts of dibutyltin dilaurate as a curing catalyst, and sufficiently kneaded and dispersed while degassing under reduced pressure. A curable composition was prepared, and a sample for a contamination test was prepared using the curable composition.
After curing at RH% for 14 days, an exposure test was performed. Table 1 shows the results.

[0046]

[Table 1]

[0047]

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 excellent weather resistance, and particularly has excellent stain resistance. It is most suitable as a moisture-curable sealing material.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C09K 3/10 C09K 3/10 Z F term (Reference) 4H017 AA04 AA31 AB05 AC05 AC11 AC19 AD06 AE03 AE05 4J034 BA07 DA01 DB04 DB05 DG01 DP18 DP19 EA11 HA07 HC03 HC22 HC46 HC52 HC61 HC64 HC71 JA42 JA46 QA01 QA05 QA07 QB12 QB13 RA08 RA10 RA12 RA17

Claims (7)

[Claims] 1. A polyisocyanate composition comprising: 1) an isocyanate-terminated prepolymer derived from an aliphatic and / or alicyclic diisocyanate monomer; and 2) an unsaturated compound capable of reacting with oxygen. 2. The poly according to claim 1, wherein the unsaturated compound capable of reacting with oxygen is at least one selected from the group consisting of diene polymers, drying oils and modified products thereof. Isocyanate composition. 3. An isocyanate-terminated prepolymer 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 The polyisocyanate composition according to claim 1 or 2, wherein 1) isocyanate average functional group number is 2 to 4 2) number average molecular weight is 3,000 to 30,000 3) viscosity is 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.