JP2002053634A - Polyisocyanate composition excellent in mechanical property - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sealing material which uses a polyisocyanate composition having a slight urethane bond in a resin, a low viscosity, containing no low- molecular weight compound to cause reduction in surface tack and has especially a low modulus and is excellent in stain resistance and tack resistance. SOLUTION: This polyisocyanate composition is characterized by comprising (A) an isocyanate terminal prepolymer obtained from an aliphatic and/or alicyclic diisocyanate monomer and (B) at least one or more kinds selected from polymer plasticizers. This sealing material is obtained by using the polyisocyanate composition.

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. An isocyanate group-terminated high molecular weight product obtained by the above method 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 means that the viscosity increases due to the urethane bond,
Increase 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, but 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. A compound forms, which is not reactive and causes surface tack.

C) In the high molecular weight product obtained under such conditions, unreacted diisocyanate monomer remains, and at the time of curing,
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 lower modulus and higher stain resistance.

[0006]

SUMMARY OF THE INVENTION The present invention provides a polyisocyanate composition having a low urethane bond in a resin and a low viscosity, and a moisture-curable sealing material using the same, particularly having a low modulus and excellent stain resistance. The purpose is to:

[0007]

Means for Solving the Problems The present inventors have proposed that an isocyanate-terminated prepolymer has a number average molecular weight of 300 to 20,
000 polyester, polyether, polystyrene, polybutadiene, alkyd resin, polychloroprene, butadiene-acrylonitrile copolymer, ethylene glycol-propylene glycol copolymer, polyoxyalkylene monoether, natural oil, epoxidized natural oil It has been surprisingly found that high contamination resistance can be achieved while having a low modulus by adding at least one of polymeric plasticizers such as paraffins and polyolefin waxes. .

That is, the present invention is as follows. 1) Moisture curing, comprising (A) an isocyanate-terminated prepolymer obtained from an aliphatic and / or alicyclic diisocyanate monomer and (B) at least one selected from polymeric plasticizers. -Type polyisocyanate composition. 2) The polymer plasticizer has a number average molecular weight of 300 to 20,000.
No. 00 polyester, polyether, polystyrene, polybutadiene, alkyd resin, polychloroprene, butadiene-acrylonitrile copolymer, ethylene glycol-propylene glycol copolymer, polyoxyalkylene monoether, natural oil, epoxidized natural oil The polyisocyanate composition according to claim 1, wherein the composition is a paraffin or a polyolefin wax.

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. The polyisocyanate composition according to 1) or 2), wherein the composition satisfies all of the following conditions: A) Isocyanate average number of functional groups 2 to 4) Number average molecular weight 3,000 to 30,000) Viscosity 1,000 to 100,000 mPa · s /
At 25 ° C) Concentration of isocyanate group 0.05 to 10 wt% (approx.) Diisocyanate monomer concentration 0 to 5 wt%

4) The polyisocyanate composition according to 3), wherein the isocyanate-terminated prepolymer contains an allophanate bond. 5) The polyisocyanate composition according to 4), wherein the allophanate bond ratio is 0.05 to 0.4. 6) The polyisocyanate composition according to 5), which is a moisture-curable type. 7) A sealing material comprising the polyisocyanate composition according to any one of 1) to 6).

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 HDI) 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. HDI is more preferred.

The average number of hydroxyl functional groups of the polyol used in the present invention is preferably 2-3. 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. For the production of polyether polyols, specifically, polyhydric alcohols, polyhydric phenols, polyamines, alkanolamines and the like, specifically, for example, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,4-butanediol , 1,6-hexanediol, dihydric alcohols such as bisphenol A, glycerin, trihydric alcohols such as trimethylolpropane,
Diamines such as ethylenediamine alone or in a mixture, for example, lithium, sodium, hydroxides such as potassium, alcoholates, strong basic catalysts such as alkylamines, metal porphyrins, complex metal cyanide complexes,
Using a complex of a metal with a chelating agent having a tridentate or higher coordination or a complex metal complex such as a zinc hexacyanocobaltate complex, an alkylene oxide such as ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, or styrene oxide alone Or it is obtained by adding a mixture. 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. When the molecular weight is less than 3,000, physical properties of the cured resin such as elongation are reduced, and when it is more than 30,000, 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 solution may be used, but in that case, it is preferable to use a solution inert to the isocyanate.
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. As the catalyst, those having basicity are generally preferable. 1) For example, a quaternary amine compound obtained from a tetraalkylammonium hydroxide and an organic weak acid group such as acetic acid and capric acid, 2) for example, trioctylamine, 1,4-diazabicyclo (2,2,2) octane, 1,8-diazabicyclo (5,4,0) undecene-7, 1,5-diazabicyclo (4,3,0) nonene-
A catalyst which promotes the allophanation reaction such as a tertiary amine compound such as 5, 3) a metal salt of acetylacetone such as zinc, or a metal organic weak acid salt such as zinc, tin, lead or iron is also effective.

Usually, the catalyst concentration is preferably in the range of 10 ppm to 1.0% based on 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 binding ratio is expressed as allophanate binding / (urethane binding +
Allophanate bond), whose value is 0.05-
0.4, more preferably 0.2
~ 0.4. If the value is less than 0.05, good physical properties such as curability may not be obtained,
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 the prepolymer may be mixed and adjusted such that the allophanate binding ratio satisfies the above range after purification.

After the reaction, the unreacted diisocyanate monomer and solvent are removed by a method such as thin film distillation or extraction to obtain a polyisocyanate product. The diisocyanate monomer concentration in the polyisocyanate product is
It is preferably at most 5%, more preferably at most 1%, even more preferably at most 0.5%. If the diisocyanate monomer concentration exceeds 5%, foaming tends to occur when the polyisocyanate product is cured.

The polyisocyanate product thus obtained preferably has an isocyanate functional group number of 2 to 2.
4. The isocyanate group concentration is preferably 0.05 to 10
wt%, more preferably 0.5 to 5 wt%, and the viscosity at 25 ° C. is preferably 1,000 to 100,
000 mPa · s, more preferably 3,000 to 50,
000 mPa · s. Isocyanate group concentration is 0.
If it is less than 05 wt%, it is difficult to obtain sufficient curability,
If it exceeds 10 wt%, there is a tendency that a sufficiently low modulus cannot be obtained. On the other hand, if the viscosity is less than 1,000, it is difficult to obtain sufficient thixotropic properties, and if it exceeds 100,000, the viscosity tends to be high and the workability tends to be poor.

The high molecular weight plasticizer which can be used in the present invention is a polyester type having a number average molecular weight of 300 to 20,000,
Polyether, polystyrene, polybutadiene,
Alkyd resins, polychloroprene, butadiene-acrylonitrile copolymer, ethylene glycol-propylene glycol copolymer, polyoxyalkylene monoether, natural oil, epoxidized natural oil, paraffins, and polyolefin wax are preferred. Examples of the polymer plasticizer containing an ester group include an aliphatic linear polyester, a vinyl acetate-based copolymer, and a methyl methacrylate-based copolymer. Aliphatic linear polyesters are synthesized by polycondensation of dibasic acids such as adipic acid, sebacic acid and phthalic acid with glycols such as 1,2-propylene glycol and 1,3-butylene glycol, for example, polypropylene glycol adipate. and so on. The vinyl acetate copolymer is typified by a copolymer of ethylene and vinyl acetate. The methyl methacrylate copolymer is obtained by copolymerizing methyl methacrylate with an alkyl acrylate or the like. As a polymer plasticizer containing an ether group is a polyoxyalkylene glycol ether,
Polyethylene glycol, polypropylene glycol and the like are used.

Others include epoxidized natural oils such as poly-α-methylstyrene and epoxidized soybean oil, castor oil, chlorinated paraffin, liquid paraffin, liquid polybutene, liquid polyisobutylene, liquid polybutadiene, liquid polyisoprene, hydrogenated Liquid polybutadiene, hydrogenated liquid polyisoprene, other polyolefin waxes and the like are used, but those compatible with the isocyanate-terminated prepolymer of the present invention can be used.

In the present invention, it is essential to add one or more polymer plasticizers to the isocyanate-terminated prepolymer. The amount of the above-mentioned polymer plasticizer is 0.1 to 100 parts by mass of the isocyanate-terminated prepolymer of the present invention.
The amount is preferably 100 parts by mass, more preferably 1 to 50 parts by mass, and still more preferably 5 to 30 parts by mass. When the amount is less than 0.1 part by mass, the effect of adding the polymer plasticizer is reduced, and when the amount is more than 100 parts by mass, mechanical properties such as elongation tend to deteriorate.

The polyisocyanate composition of the present invention may contain a stabilizer, an inert solvent, a filler, a photocurable substance, a thickener or a thixotropic agent, a curing catalyst, titanium oxide, an adhesive agent,
Dyes, pigments, flame retardants, etc. are blended to form 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.

As the inert solvent, for example, toluene,
Aromatic hydrocarbons such as xylene, hexane, heptane,
Examples include aliphatic hydrocarbons such as octane, petroleum solvents such as gasoline, kerosene, and process oil. As a filler,
For example, there are silicic acid derivatives, talc, metal powder, calcium carbonate, clay, carbon black and the like. Examples of the photocurable substance include unsaturated acrylic compounds, polyvinyl cinnamate, and azide resin. Photocurable substances are those that cause physical changes such as curing by light, and various types of substances such as organic monomers, oligomers, resins, and compositions containing these are known. In the present invention, any commercially available substance can be used.

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 laurate, 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.

Specific examples of titanium oxide include, 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 trademarks of 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, and the like. Silane coupling agents.

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-based polyether include a polyether having an average number of hydroxyl groups of 2 to 3 used for obtaining the polyisocyanate product. 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 mass". 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.

(Viscosity) The viscosity at a temperature of 25 ° C. was measured by an E-type viscometer. (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 a twin mix (manufactured by Dalton).

(Contamination test) 12 m wide using a siding board (trademark “Kanbe” of Toray Grasal Co., Ltd.)
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 65 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 65 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 after curing at 20 ° C. and a humidity of 65 RH% for 3 weeks, a width of 1 mm was obtained.
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 mm ² at the start of the measurement.

[0034]

[Production Example 1] A four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blower, and a dropping funnel was set to a nitrogen atmosphere, and 600 parts of HDI was added to a divalent polyether polyol (trade name of Asahi Glass "Preminol 8000"). 1000 parts (equivalent ratio of isocyanate group / hydroxyl group 28.6 / 1) was charged in a nitrogen atmosphere.
The temperature inside the reactor was maintained at 160 ° C. for 3 hours with stirring.

The temperature of the reaction solution was lowered, and unreacted HDI was removed using a thin film evaporator. The number average molecular weight of the obtained isocyanate-terminated prepolymer (prepolymer A) is 80.
00, isocyanate group concentration 1.7%, viscosity 600
The allophanate binding ratio was 0 mPa · s, the diisocyanate monomer concentration was 0.2%, and the average number of isocyanate functional groups was 3.2.

[0036]

[Production Example 2] A four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blower, and a dropping funnel was set to a nitrogen atmosphere, and 600 parts of HDI was added to a divalent polyether polyol (trade name of Asahi Glass "Preminol 8000"). 1000 parts (equivalent ratio of isocyanate group / hydroxyl group 28.6 / 1) was charged in a nitrogen atmosphere.
The temperature inside the reactor was kept at 120 ° C. for 8 hours with stirring. The temperature of the reaction solution was lowered, and unreacted HDI was removed using a thin film evaporator. The number average molecular weight of the obtained isocyanate-terminated prepolymer (prepolymer B) is 8000, the isocyanate group concentration is 1.0%, the viscosity is 6000 mPa · s, the allophanate binding ratio is 0.00, the diisocyanate monomer concentration is 0.2%, The average isocyanate functionality was 2.0.

[0037]

[Production Example 3] Prepolymer A 100 parts, Prepolymer B
400 parts were sufficiently kneaded and dispersed. The obtained mixed isocyanate-terminated prepolymer (prepolymer C) had a number average molecular weight of 8000, an isocyanate group concentration of 1.1%, a viscosity of 6000 mPa · s, and an allophanate binding ratio of 0.
12. The diisocyanate monomer concentration was 0.2%, and the average number of isocyanate functional groups was 2.1.

[0038]

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.) was used. 20), prepolymer C (100 parts), high molecular weight plasticizer ("PF-X716" alkyl-terminated PPG manufactured by Asahi Glass Co., Ltd.) 20 parts, and 20% by weight dissolved in tetrahydrofuran. 5.5 parts of tinuvin 327 and 0.2% of BHT dissolved in tetrahydrofuran at 50% by weight.
Parts, 0.2 parts of dibutyltin dilaurate as a curing catalyst, kneading and dispersing sufficiently while deaeration under reduced pressure to prepare a curable composition, and using the curable composition for a contamination test and evaluation of strength and elongation. Sample for 20 ℃, 65RH%
After curing for a week, an exposure test, tackiness test, and tensile test were performed. Table 1 shows the results.

[0039]

Example 2 The same procedure as in Example 1 was carried out except for the amount of the polymer plasticizer shown in Table 1. Table 1 shows the results.

[0040]

[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, 100 parts of prepolymer C, 5.5 parts of tinuvin 327 dissolved in tetrahydrofuran at 20% by weight, 0.2 parts of BHT dissolved in tetrahydrofuran at 50% by weight, and a curing catalyst 0.2 parts of dibutyltin dilaurate was added, and kneaded and dispersed sufficiently while deaeration under reduced pressure to prepare a curable composition. Using the curable composition, a contamination test and a sample for elongation evaluation were prepared. Then 20
After curing for 3 weeks at 65 ° C. and 65% RH, an exposure test, a tackiness test, and a tensile test were performed. Table 1 shows the results.

[0041]

[Comparative Example 2] 100 parts of light calcium carbonate (trade name: Calfine 200M of Maruo Calcium) was mixed with
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, dioctyl phthalate 40 parts, tinuvin 327 dissolved in tetrahydrofuran at 20% by weight, 5.5 parts, and BHT dissolved in tetrahydrofuran at 50% by weight at 0.2%. 2 parts, 0.2 parts of dibutyltin dilaurate as a curing catalyst were added, and the mixture was sufficiently kneaded and dispersed while deaeration under reduced pressure to prepare a curable composition. An evaluation sample was prepared, and after curing at 20 ° C. and 65 RH% for 3 weeks, an exposure test, a tack test, and a tensile test were performed. Table 1 shows the results.

[0042]

[Table 1]

[0043]

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 is a moisture-curable sealing material. Optimal.

──────────────────────────────────────────────────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 AB03 AC01 AC05 AD05 AD06 AE03 AE05 4J002 AE032 AE042 AE052 BB062 BB172 BC092 BF032 BG042 BG062 BL012 CD162 CF102 CH052 CK031 CK041 CK051 EA016 FD010 FD022 FD026 GJ02 4J034 BA03 DA01 DB03 DB04 DB05 DB07 DF01 DG02 DG03 HC13 HC03 HC03 HC01 HC13 DG04 DG05 PG04 HC07 KC08 KC17 KC18 KC35 KD02 KD12 KE03 QA01 QA02 QA05 RA08

Claims (7)

[Claims] 1. It comprises (A) an isocyanate-terminated prepolymer obtained from an aliphatic and / or alicyclic diisocyanate monomer and (B) at least one selected from polymeric plasticizers. , Polyisocyanate composition. 2. The polymer plasticizer has a number average molecular weight of 300 to 300.
20,000 polyester, polyether, polystyrene, polybutadiene, alkyd resin, polychloroprene, butadiene-acrylonitrile copolymer,
Ethylene glycol-propylene glycol copolymer,
The polyisocyanate composition according to claim 1, which is a polyoxyalkylene monoether, a natural oil, an epoxidized natural oil, a paraffin, or a polyolefin wax. 3. An isocyanate-terminated prepolymer comprising an aliphatic and / or alicyclic diisocyanate having a number average molecular weight of 3,000 to 30,000 and an average number of hydroxyl groups of 2 to 3.
3 is obtained by reacting with the polyol of the present invention, and characterized by satisfying all the following conditions,
The polyisocyanate composition according to claim 1. 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 / 2
5 ° C 4) Isocyanate group concentration 0.05 to 10 wt% 5) Diisocyanate monomer concentration 0 to 5 wt% 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.