JPH11130829A - Moisture-curing polyurethane resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moisture-curing polyurethane resin composition having excellent weather resistance compared with conventional moisture-curing polyurethane resin compositions. SOLUTION: This polyurethane resin composition contains 100 pts.wt. of a urethane prepolymer having isocyanate group on molecular terminal, 0.01-30 pts.wt. of a (meth) acrylic compound and 0.01-30 pts.wt. of a hindered phenol antioxidant which causes steric hindrance to either one of carbon atoms positioned at the 2- and 6-sites of the benzene ring based on the carbon of a benzene ring bonded with the hydroxyl group of the phenolic skeleton.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a moisture-curable polyurethane resin composition, and more particularly, to a moisture-curable polyurethane resin composition which can be suitably used for a sealing material, a waterproof material, a paint, an adhesive and the like.

[0002]

2. Description of the Related Art Conventionally, moisture-curable polyurethane resin compositions have been widely used as sealing materials, waterproof materials, paints, adhesives, etc. because of their excellent flexibility, extensibility, adhesiveness and the like. However, the moisture resistance of the conventionally used moisture-curable polyurethane resin composition is not sufficient, and when it is used outdoors, it is liable to be deteriorated by rainwater and temperature changes, particularly ultraviolet rays, and cracks and There is a problem that chalking or the like occurs.

[0003] Therefore, for example, Japanese Patent Publication No. Sho 63-5267.
Japanese Patent Application Laid-Open No. 9-278247 proposes that a moisture-curable polyurethane resin composition is blended with an acrylic compound to improve weather resistance, and Japanese Patent Application Laid-Open No. 7-278247 discloses that a hydroxyl group-containing (meth) compound is used. It has been proposed to improve the weather resistance by using a urethane prepolymer modified with an acrylic compound.

[0004]

However, the above-mentioned Japanese Patent Publication No. Sho 63-52679 and Japanese Patent Laid-Open Publication No. 7-27824.
Even the method proposed in Japanese Patent Publication No. 7 cannot obtain sufficient weather resistance enough to be practically satisfactory. Accordingly, the present invention has been made in view of such circumstances, and has an object to provide a moisture-curable polyurethane resin composition having better weather resistance than the above-described moisture-curable polyurethane resin composition. I do.

[0005]

In order to achieve the above object, a moisture-curable polyurethane resin composition of the present invention comprises a urethane prepolymer having an isocyanate group at a molecular terminal, a (meth) acrylic compound, For the carbon of the benzene ring to which the hydroxyl group of the skeleton is bonded,
A hindered phenolic acid inhibitor having a substituent capable of sterically hindering only one of the carbons of the benzene ring at the 2- or 6-position. .

[0006] Further, the substituent which may be steric hindrance of the hindered phenolic antioxidant is represented by the following formula (1):
—CR ₁ R ₂ R ₃ (wherein, R ₁ R ₂ R ₃ represents hydrogen or a hydrocarbon group, and at least two of R ₁ R ₂ R ₃ represent a hydrocarbon group) or Formula (2): -C
H ₂ —CR ₄ R ₅ R ₆ (wherein, R ₄ R ₅ R ₆ represents a hydrogen or a hydrocarbon group, and at least two of R ₄ R ₅ R ₆ represent a hydrocarbon group.) It is preferable that it is a group represented by these, and it is more preferable that it is a tert-butyl group.

In addition, the (meth) acrylic compound is
(Meth) acrylic acid esters and / or (meth) acrylic acid amides are preferred. In addition, the moisture-curable polyurethane resin composition of the present invention may contain the (meth) acrylic compound and the hindered phenolic antioxidant in an amount of 0.01 to 30 parts by weight based on 100 parts by weight of the urethane prepolymer. It is preferred that the content be contained by weight.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The urethane prepolymer having an isocyanate group at a molecular terminal used in the present invention generally comprises an active hydrogen group-containing compound having two or more active hydrogen groups in one molecule and a polyisocyanate. And an isocyanate group of the polyisocyanate so that the isocyanate groups are excessive in relation to the active hydrogen groups of the active hydrogen group-containing compound. Any urethane prepolymer having an isocyanate group at the molecular end can be used without any particular limitation.

The active hydrogen group-containing compound used as a raw material of the urethane prepolymer of the present invention includes, for example,
Ethylene glycol, 1,2-propanediol, 1,
3-propanediol, 1,4-butylene glycol,
1,3-butylene glycol, 1,2-butylene glycol, 1,6-hexanediol, neopentyl glycol, alkane (C7-C22) diol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, cyclohexane dimethanol , Alkane-1,2-diol (C17-
C20), hydrogenated bisphenol A, 1,4-dihydroxy-2-butene, 2,6-dimethyl-1-octene-
3,8-diol, bishydroxyethoxybenzene,
Low molecular weight diols such as xylene glycol and bishydroxyethylene terephthalate, for example, glycerin, 2-
Methyl-2-hydroxymethyl-1,3-propanediol, 2,4-dihydroxy-3-hydroxymethylpentane, 1,2,6-hexanetriol, 1,1,1
Low molecular weight triols such as tris (hydroxymethyl) propane, 2,2-bis (hydroxymethyl) -3-butanol, and other aliphatic triols (C8-C24), for example, ethylenediamine, propylenediamine,
Hexamethylenediamine, hydrazine, 1,2-diaminoethane, 1,2-diaminopropane, 1,3-diaminopentane, 1,6-diaminohexanediaminotoluene, bis- (4-aminophenyl) methane, bis- (4
-Amino-3-chlorophenyl) low molecular weight diamines such as methane, triethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, and trifunctional or higher molecular weight low molecular weight polyamines such as 2,2'-diaminodiethylamine. Low molecular weight diols, low molecular weight triols, low molecular weight diamines and trifunctional or higher molecular weight low molecular weight polyamines and the like, and polyoxyalkylene polyols obtained by addition reaction with alkylene oxides such as ethylene oxide and propylene oxide,
For example, polytetramethylene glycol obtained by ring-opening polymerization of tetrahydrofuran, for example, one or more of the above-mentioned low molecular diols and low molecular triols, and oxalic acid, malonic acid, succinic acid, methyl succinic acid,
Glutaric acid, adipic acid, 1,1-dimethyl-1,3
-Dicarboxypropane, 3-methyl-3-ethylglutaric acid, azelaic acid, sebacic acid, other aliphatic dicarboxylic acids (C11 to 13), hetic acid and acid anhydrides composed of these carboxylic acids, ie, anhydrous Obtained by reaction with oxalic acid, succinic anhydride, 2-alkyl (C12-C18) succinic anhydride, and an acid halide composed of these carboxylic acids, ie, oxalic acid dichloride, adipic acid chloride, sebacic acid chloride and the like. Polyester polyols, for example, the aforementioned low-molecular diols, polyester polyols obtained by ring-opening polymerization of lactones such as ε-caprolactone and γ-valerolactone using the low-molecular triols and the like as initiators, for example, the low-molecular diols and Starting ethylene carbonate using molecular triol etc. as an initiator Polycarbonate polyols obtained by ring polymerization, for example, natural fats and oils polyols such as castor oil, for example, polybutadiene polyols, polyolefin polyols such as polyisoprene polyols and hydrogenated products thereof, for example, one or more hydroxyl groups in one molecule Polymerizable monomers such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. With other polymerizable monomers, that is, (meth) acrylic acid, alkyl (meth) acrylate (C1-C12) ester, maleic acid, fumaric acid, styrene, α-methylstyrene, (meth) acrylonitrile, etc. Acrylic obtained by copolymerization Mention may be made of the polyols and the like. These may be used alone or in combination of two or more. Of these, polyoxyalkylene polyols are preferred.

The polyisocyanate used as a raw material of the urethane prepolymer of the present invention includes, for example, m
-Phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenyl diisocyanate,
1,5-naphthalenediisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4- or 2,6-
Tolylene diisocyanate or a mixture thereof, 4,
Aromatic diisocyanates such as 4'-toluidine diisocyanate and 4,4'-diphenyl ether diisocyanate, for example, araliphatic diisocyanates such as 1,3- or 1,4-xylylene diisocyanate or a mixture thereof, for example, trimethylene diisocyanate, tetra Methylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2
-Propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate,
Aliphatic diisocyanates such as 1,3-butylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, for example, 1,3-cyclopentene diisocyanate; 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), methyl-
2,4-cyclohexane diisocyanate, methyl-
Alicyclic diisocyanates such as 2,6-cyclohexane diisocyanate and 1,4-bis (isocyanatomethyl) cyclohexane, and carbodiimide-modified, biuret-modified, allophanate-modified, dimer, trimer, or diisocyanate of these diisocyanates Examples thereof include polyisocyanates used in the production of ordinary polyurethane resins, such as polymethylene polyphenyl polyisocyanate (crude MDI, polymeric MDI), and these may be used alone or in combination of two or more. Among these,
1,3- or 1,4-xylylene diisocyanate or a mixture thereof is preferred.

The method for producing a urethane prepolymer having an isocyanate group at the molecular terminal according to the present invention may be under ordinary production conditions for a urethane prepolymer. That is, as described above, the active hydrogen group-containing compound is reacted with the polyisocyanate such that the isocyanate groups of the polyisocyanate are in excess with respect to the active hydrogen groups of the active hydrogen group-containing compound. Manufactured. As the production conditions, for example, the equivalent ratio of the isocyanate group to the hydroxyl group (NCO / OH) of the active hydrogen group-containing compound and the polyisocyanate is 1.1 to 1.0.
The reaction is carried out at a reaction temperature of 50 to 80 ° C. for about several hours under a nitrogen stream at a ratio of 4.0, preferably 1.3 to 3.0. In this reaction, a known urethanization catalyst such as an organic acid-based, tin-based, lead-based, or amine-based catalyst may be used, if necessary. The resulting urethane prepolymer having an isocyanate group at the molecular terminal has an isocyanate group content of 0.7% to 4.0%, and more preferably 0.7% to 4.0%.
It is preferably in the range of 8% to 2.0%.

The acrylic compound used in the present invention is:
There is no particular limitation, and examples thereof include monomers, oligomers having one or several acryl unsaturated groups or methacryl unsaturated groups in the molecule, or mixtures thereof. These are the same as acrylic acid and methacrylic acid, but also the amino and hydroxyl groups of compounds containing amino and hydroxyl groups.
Acrylic acid (indicating acrylic acid or methacrylic acid)
In the present invention, (meth) acryl means acryl or methacryl. )), Which includes a reaction product of the acid obtained by the amidation reaction and the esterification reaction, that is, a (meth) acrylate or a (meth) acrylamide.

Specific examples of these (meth) acrylic acid ester or (meth) acrylic acid amide monomers include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate,
-Hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxy-3
-Phenyloxypropyl (meth) acrylate, 2-
Hydroxyalkyl (C1-C20) (meth) acryloyl phosphate, 4-hydroxycyclohexyl (meth) acrylate, neopentyl glycol mono (meth) acrylate, methoxyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, nonylphenoxy Ethyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, phenoxypolypropylene glycol (meth) acrylate, butoxypolyethylene glycol (meth) acrylate, Alkyl (C1-C20)
(Meth) acrylate, cyclohexyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, benzyl (meth) acrylate, cumylphenol (meth) acrylate, cumylphenoxy polyethylene glycol (meth) acrylate, Milphenoxy polypropylene glycol (meth) acrylate, 2-ethylhexyl (meth) acrylate, dicyclopentadiene dimethanol mono (meth) acrylate, 2- (meth) acryloyloxyethyl-2-hydroxyethylphthalic acid, 3
-Acryloyloxyglycerin mono (meth) acrylate, 2-hydroxy-1- (meth) acryloxy-3
-(Meth) acryloxypropane, polypropylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, polyε-caprolactone mono (meth) acrylate, dialkyl (C1 to C2)
0) aminoethyl (meth) acrylate, glycidyl (meth) acrylate, mono [2- (meth) acryloyloxyethyl] acid phosphate, trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl ( Meth) acrylate, 2,2,3,4
4,4-hexafluorobutyl (meth) acrylate, perfluorooctylethyl (meth) acrylate, dicyclopentenyloxyalkyl (C1-C20) (meth)
Acrylate, dicyclopentenyl (meth) acrylate, tricyclodecanyl (meth) acrylate, tricyclodecanyloxyethyl (meth) acrylate, isobornyloxyethyl (meth) acrylate, morpholine (meth) acrylate and N, N ' -Compounds having one (meth) acrylic unsaturated group in the molecule, such as dimethylacrylamide.

Also, for example, di (meth) acrylate of trimethylolpropane di (meth) acrylate, 2,2-dimethyl-3-hydroxypropyl-2,2-dimethyl-3-hydroxypropionate, ethylene glycol di ( (Meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1,4-butanediol di (meth)
Acrylate, 1,6-hexanediol di (meth) acrylate, glycerin di (meth) acrylate, neopentyl glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate hydroxypivalate, ethylene oxide adduct of bisphenol A Di (meth) acrylate, di (meth) acrylate of propylene oxide adduct of bisphenol A, 2,
2'-di (hydroxyethoxyphenyl) propane di (meth) acrylate, tricyclodecane dimethylol di (meth) acrylate, dicyclopentadiene dimethanol di (meth) acrylate, 1,5-pentanediol di (meth) Compounds having two (meth) acrylic unsaturated groups in a molecule such as acrylate and (meth) acrylic acid adduct of 2,2′-di (glycidyloxyphenyl) propane are exemplified.

Further, for example, trimethylolpropane tri (meth) acrylate, trimethylolpropane trioxyethyl tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate A) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, tris (acryloxy) isocyanurate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, tris (hydroxypropyl) isocyanate 3 or more (meth) acrylic unsaturated groups in the molecule such as tri (meth) acrylate, triallyl trimellitic acid, triallyl isocyanurate Compounds having the like. In addition, (meth) acrylic acid ester or (meth) acrylic acid amide oligomer, specifically, for example, a compound in which 3 or 4 acrylic acid is ester-bonded to an ester oligomer such as oligoester (meth) acrylate Is mentioned.

These acrylic compounds may be used alone or in combination of two or more. Among them, 2-hydroxyethyl (meth) acrylate, pentaerythritol tetra (meth) acrylate, oligoester (meth) acrylate and the like are preferable. . The proportion of the acrylic compound is preferably in the range of 0.01 to 30 parts by weight based on 100 parts by weight of the urethane prepolymer. If the amount is less than 0.01 part by weight, the weather resistance may not be improved, and if it exceeds 30 parts by weight, the adhesiveness may be reduced. More preferably, 0.1 to 100 parts by weight of the urethane prepolymer.
The range is 10 parts by weight.

The hindered phenolic antioxidant used in the present invention may be any one of the carbons of the benzene ring at the 2- or 6-position with respect to the carbon of the benzene ring to which the hydroxyl group of the phenol skeleton is bonded. It is a hindered phenolic antioxidant having a substituent which can be sterically hindered on only one of the carbons. Generally, a hindered phenolic antioxidant is a substituent capable of acting as a steric hindrance to both the carbons of the benzene ring at the 2- and 6-positions relative to the carbon of the benzene ring to which the hydroxyl group of the phenol skeleton is bonded. In the present invention, any one of the carbons of the benzene ring at the 2- or 6-position with respect to the carbon of the benzene ring to which the hydroxyl group of the phenol skeleton is bonded. A compound having a substituent capable of acting as a steric hindrance only on one carbon is used. here,
Examples of the substituent capable of acting as a steric hindrance include groups represented by the following formulas (1) and (2) in which the group bonded to the carbon of the benzene ring at the 2- or 6-position. (1) Formula: -CR ₁ R ₂ R ₃ (wherein, R ₁ R ₂ R
₃ represents hydrogen or a hydrocarbon group, and R ₁ R ₂ R
_At least two of the three represent hydrocarbon groups. (2) Formula: —CH ₂ —CR ₄ R ₅ R ₆ (wherein, R ₄ R ₅
R ₆ represents a hydrogen or hydrocarbon group, and R ₄ R ₅
At least two of R ₆ represent a hydrocarbon group. Here, the hydrocarbon groups represented by R ₁ R ₂ R ₃ R ₄ R ₅ and R ₆ are, for example, hydrocarbon groups having 1 or more carbon atoms, preferably 1 to 20 carbon atoms, and as,
For example, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, a cycloalkenyl group, an aryl group,
Aralkyl groups and the like. Preferably, carbon number 1
And an alkyl group of 4, more preferably a methyl group and an ethyl group.

Specific examples of such a substituent which may cause steric hindrance include, for example, isopropyl group, sec-
Butyl group, t-butyl group, 1-methyl-butyl group, 1-
Ethyl-propyl group, 1,1-dimethyl-propyl group,
2,2-dimethyl-propyl group (t-pentyl group), 1
And alkyl groups having 3 to 8 carbon atoms such as -ethyl-1-methyl-propyl group, 1,1-diethyl-propyl group and 2,2-diethyl-butyl group. Of these, t-
Butyl groups are preferred.

On the other hand, for example, a methyl group or the like does not correspond to the substituent which can be steric hindrance here. Accordingly, the most preferred embodiment of the hindered phenolic antioxidant of the present invention is the benzene ring carbon at the 2- and 6-positions relative to the benzene ring carbon to which the hydroxyl group of the phenol skeleton is bonded. Is that one of the carbons at the 2- or 6-position has a substituent of a tert-butyl group and the other carbon has no substituent or a substituent of a methyl group. The aspect which has these is mentioned. Hereinafter, such a compound is referred to as a one-sided hindered phenol-based antioxidant. On the other hand, the benzene ring carbon to which the hydroxyl group of the phenol skeleton is bonded has a substituent capable of acting as a steric hindrance at both the benzene ring carbon at the 2-position and the 6-position. The compounds will be referred to as both hindered phenolic antioxidants.

Further, a substituent which may be steric hindrance is te
Examples of the one-sided hindered phenolic antioxidant which is an rt-butyl group include, for example, triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate] (trade name: IRGANOX)
245, manufactured by Nippon Ciba Geigy), 3,9-bis [2-
{3- (3-t-butyl-4-hydroxy-5-methylphenyl) -propionyloxy} -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro (5,5) undecane ( Product Name: Smilizer G
A-80, manufactured by Sumitomo Chemical Co., Ltd.), 4,4′-butylidenebis (3-methyl-6-t-butylphenol) (trade name: Smilizer BBM-S, manufactured by Sumitomo Chemical Co., Ltd.), 4,4′-thiobis (3-methyl-6-t-butylphenol) (trade name: Smilizer WX-
R, manufactured by Sumitomo Chemical Co., Ltd.).

These single hindered phenolic antioxidants may be used alone or in combination of two or more. Among them, triethylene glycol-bis [3- (3-t-butyl-5-methyl-4- Hydroxyphenyl) propionate] (trade name: IRGANOX245, manufactured by Nippon Ciba Geigy), 3,9-bis [2- {3- (3-t-butyl-4-hydroxy-5-methylphenyl) -propionyloxy} -1 , 1-dimethylethyl] -2,4
Preferred is 8,10-tetraoxaspiro (5,5) undecane (trade name: Smilizer GA-80, manufactured by Sumitomo Chemical Co., Ltd.). The proportion of the single-sided hindered phenolic antioxidant is preferably in the range of 0.01 to 30 parts by weight based on 100 parts by weight of the urethane prepolymer. If the amount is less than 0.01 part by weight, the weather resistance may not be improved, and if it exceeds 30 parts by weight, the adhesiveness may be reduced. More preferably, it is in the range of 0.1 to 10 parts by weight based on 100 parts by weight of the urethane prepolymer.

The moisture-curable polyurethane resin composition of the present invention is obtained by mixing a urethane prepolymer, an acrylic compound and a single-sided hindered phenol antioxidant by mixing, kneading or the like, preferably in the above-mentioned ratio. Can be obtained by In this case, the acrylic compound may be reacted with the urethane prepolymer. Such a reactant is obtained, for example, by preparing an urethane prepolymer and then reacting an acrylic compound having an active hydrogen group capable of reacting with an isocyanate group such as 2-hydroxyethyl (meth) acrylate with an isocyanate of the urethane prepolymer. Group and reaction temperature 60-70 ° C
For about several hours.
When producing a urethane prepolymer, an acrylic compound having an active hydrogen group capable of reacting with an isocyanate group may be reacted with a polyisocyanate together with an active hydrogen group-containing compound. A certain acrylic polyol may be used as it is as an acrylic compound.

The moisture-curable polyurethane resin composition of the present invention thus obtained may contain a filler, if necessary.
A plasticizer and a solvent may be blended. As the filler, for example, calcium carbonate, silicon oxide, titanium oxide,
Clay, talc, carbon black and the like can be mentioned. These fillers are blended in the moisture-curable polyurethane resin composition at about 10 to 70% by weight.

Examples of the plasticizer include dimethyl phthalate, diethyl phthalate, dioctyl phthalate, butylbenzyl phthalate, diisodecyl phthalate, dibutyl sebacate, tricresyl phosphate, and triphenyl phosphate. These plasticizers are blended in the moisture-curable polyurethane resin composition in an amount of about 5 to 40% by weight.

As the solvent, for example, benzene,
Examples include toluene, xylene and mixtures thereof, and petroleum solvents such as mineral terpenes. These solvents are
1 to 30% by weight in the moisture-curable polyurethane resin composition
Degree is blended. Further, the moisture-curable polyurethane resin composition of the present invention may contain, if necessary, other known curing catalysts and various additives, such as an antifoaming agent, a leveling agent, a matting agent, a twist-resistant agent, and a dispersant. , Thixotropic agents, tackifiers, thickeners, lubricants, antistatic agents, surfactants, reaction retarders, dehydrating agents, various antioxidants, weather stabilizers such as ultraviolet absorbers, hydrolysis inhibitors, Dyes, inorganic pigments, organic pigments, extenders and the like may be appropriately blended.

The moisture-curable polyurethane resin composition of the present invention thus obtained has excellent weather resistance, and hardly causes cracks or chalking in the cured product even when used outdoors. Sealing material, waterproof material,
It can be used effectively for paints, adhesives and the like.

[0027]

As described above, the moisture-curable polyurethane resin composition of the present invention comprises a urethane prepolymer having an isocyanate group at a molecular terminal, a (meth) acrylic compound, and a one-sided hindered phenolic acid inhibitor. By containing, the weather resistance is improved, and even in outdoor use,
The cured product is less likely to crack or chalk, and can be effectively used as a sealing material, a waterproof material, a paint, an adhesive, and the like.

[0028]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. The molecular weight is a number average molecular weight. Example 1 (1) Production of urethane prepolymer [A] Polyoxypropylene diol 373 having a molecular weight of 3000
Parts by weight, and 82 parts by weight of polyoxypropylene triol having a molecular weight of 3000 (both having a water content of not more than 0.03%) and 45 parts by weight of xylylene diisocyanate are placed in a kolben, and placed in a nitrogen atmosphere at 80 ° C. for 1 hour. The mixture was stirred and reacted. Subsequently, dibutyltin dilaurate 0.05
After adding parts by weight, the mixture was further reacted at 80 ° C. for 3 hours to obtain a urethane prepolymer [A] having an isocyanate group at a molecular terminal. The isocyanate group content of the obtained urethane prepolymer [A] was 1.08%. (2) Preparation of moisture-curable polyurethane resin composition 500 parts by weight of urethane prepolymer [A], 300 parts by weight of dried calcium carbonate, 50 parts by weight of dried titanium oxide, 100 parts by weight of xylene, fumed silica (trade name: Aerosil A-200, manufactured by Nippon Aerosil Co., Ltd.) 40
Parts by weight, triethylene glycol-bis [3- (3-t
-Butyl-5-methyl-4-hydroxyphenyl) propionate] (trade name: IRGANOX245, manufactured by Nippon Ciba Geigy) and 10 parts by weight of pentaerythritol tetraacrylate are charged into a planetary mixer, kneaded under vacuum, and humidified. A curable polyurethane resin composition was obtained.

Example 2 Instead of 10 parts by weight of pentaerythritol tetraacrylate, an oligoester acrylate (having a molecular weight of about 50) was used.
0, 3-4 functional, trade name: Aronix M-8060,
A moisture-curable polyurethane resin composition was obtained by the same blending and preparation method as in Example 1 except that 20 parts by weight (manufactured by Toagosei Chemical Industry Co., Ltd.) was used.

Example 3 (1) Production of acrylic-containing urethane prepolymer [B] Polyoxypropylene diol 260 having a molecular weight of 3000
Parts by weight, and 175 parts by weight of polyoxypropylene triol having a molecular weight of 3000 (both having a water content of not more than 0.03%) and 55 parts by weight of xylylene diisocyanate are placed in a kolben, and placed in a nitrogen atmosphere at 80 ° C. for 1 hour. The mixture was stirred and reacted. Subsequently, dibutyltin dilaurate 0.0
After adding 5 parts by weight, the mixture was further reacted at 80 ° C. for 3 hours. Subsequently, 2-hydroxyethyl methacrylate 1
After adding 0 parts by weight, the mixture was reacted at 60 ° C. to 70 ° C. for 2 hours to obtain an acrylic-containing urethane prepolymer [B] having an isocyanate group at a molecular terminal. The isocyanate group content of the obtained urethane prepolymer [B] is 1.1.
3%. (2) Preparation of moisture-curable polyurethane resin composition Acrylic-containing urethane prepolymer [B] 500 parts by weight, dried calcium carbonate 300 parts by weight, dried titanium oxide 50 parts by weight, xylene 100 parts by weight, fumed silica (product) Name: Aerosil A-200, manufactured by Nippon Aerosil Co., Ltd.) 40 parts by weight and 3,9-bis [2- @ 3-
(3-t-butyl-4-hydroxy-5-methylphenyl) -propionyloxy {-1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro (5
5) Undecane (trade name: Smilizer GA-8)
0, manufactured by Sumitomo Chemical Co., Ltd.) was charged into a planetary mixer and kneaded under vacuum to obtain a moisture-curable polyurethane resin composition.

Comparative Example 1 Triethylene glycol-bis [3- (3) used in Example 1 as a one-sided hindered phenolic antioxidant
-T-butyl-5-methyl-4-hydroxyphenyl)
Instead of 10 parts by weight of propionate] (trade name: IRGANOX245, manufactured by Nippon Ciba Geigy), 1,6-hexanediol-bis [3- (3,5-di-t-) is used as both hindered phenolic antioxidants. Butyl-4-
[Hydroxyphenyl) propionate] (trade name: IR
A moisture-curable polyurethane resin composition was obtained by the same blending and preparation method as in Example 1 except that 10 parts by weight of GANOX259 (manufactured by Ciba Geigy Japan) were used.

Comparative Example 2 A moisture-curable polyurethane resin composition was obtained in the same manner as in Example 1 except that pentaerythritol tetraacrylate was not used. Comparative Example 3 In Example 2, triethylene glycol-bis [3
-(3-t-butyl-5-methyl-4-hydroxyphenyl) propionate] (trade name: IRGANOX24
5, manufactured by Nippon Ciba Geigy)
A moisture-curable polyurethane resin composition was obtained by the same blending and preparation method as in Example 2.

Comparative Example 4 3,9-Bis [2- {3- (3-t-butyl-4-hydroxy-5-methylphenyl) -propionyl] used in Example 3 as a one-sided hindered phenolic antioxidant Oxy {-1,1-dimethylethyl] -2,4,
Instead of 10 parts by weight of 8,10-tetraoxaspiro (5,5) undecane (trade name: Smilizer GA-80, manufactured by Sumitomo Chemical Co., Ltd.), pentaerythrityl-tetrakis is used as both hindered phenolic antioxidants. [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (trade name: IRGANOX1
010, manufactured by Nippon Ciba Geigy Co.) A moisture-curable polyurethane resin composition was obtained by the same blending and preparation method as in Example 1 except that 10 parts by weight was used.

Evaluation of Moisture-Curable Polyurethane Resin Compositions The moisture-curable polyurethane resin compositions of Examples 1 to 3 and Comparative Examples 1 to 4 were subjected to a weather resistance test by the following method. Weather Resistance Test Method Each moisture-curable polyurethane resin composition was cured for 7 days at 25 ° C. and 50% RH at a thickness of 2 mm to obtain a sheet-shaped cured product. A sheet piece punched out with a No. 1 dumbbell specified by JIS K 6301 was used as a test piece, and the test piece was set on a sunshine weatherometer and subjected to a cycle test. The deterioration state of the test piece surface after 1500 hours and 2000 hours has passed. , Visual and finger touch.
The operating conditions of the sunshine weatherometer are as follows.

Tester: WEL-SUN-HCH-B type (manufactured by Suga Test Instruments Co., Ltd.) Spray cycle: 18 minutes / 120 minutes Black panel temperature: 63 ° C. Humidity: 60% The evaluation results are shown in Table 1.

[0036]

[Table 1]

As is clear from Table 1, in the test specimens of Examples 1 to 3 in which the acrylic compound and the single hindered phenolic antioxidant were blended, the sunshine weatherometer was operated for 2000 hours. Also maintain a good surface condition. However, the specimens of Comparative Examples 1 and 4 in which an acrylic compound and both hindered phenolic antioxidants were blended, and a comparison in which only a hindered phenolic antioxidant was blended and no acrylic compound was blended In Example 2, the occurrence of chalking and cracks was observed, and the test piece of Comparative Example 3 in which only the acrylic compound was blended and the one-sided hindered phenolic antioxidant was not blended, after 1500 hours of operation, The sheet was severely degraded and the sheet was cut.

The term "crack" used herein refers to a state in which a crack has occurred in a test piece, and the term "chalking" refers to a state in which the surface of the test piece is touched by a finger and powder such as a filler adheres to the finger.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Masahiro Miwa 2--17-85 Jusanhoncho, Yodogawa-ku, Osaka-shi, Osaka Inside the Takeda Pharmaceutical Company Chemical Company

Claims (5)

[Claims] 1. A urethane prepolymer having an isocyanate group at a molecular terminal, a (meth) acrylic compound,
It has a substituent that can cause steric hindrance to only one of the carbons of the benzene ring at the 2- or 6-position to the carbon of the benzene ring to which the hydroxyl group of the phenol skeleton is bonded. A moisture-curable polyurethane resin composition comprising a hindered phenolic acid inhibitor. 2. The substituent which may be steric hindrance of the hindered phenolic antioxidant is represented by the following formula (1): -CR ₁ R ₂ R ₃ (wherein, R ₁ R ₂ R
₃ represents hydrogen or a hydrocarbon group, and R ₁ R ₂ R
_At least two of the three represent hydrocarbon groups. Or (2) Formula: —CH ₂ —CR ₄ R ₅ R ₆ (wherein, R ₄ R ₅
R ₆ represents a hydrogen or hydrocarbon group, and R ₄ R ₅
At least two of R ₆ represent a hydrocarbon group. The moisture-curable polyurethane resin composition according to claim 1, which is a group represented by the formula: 3. The moisture-curable polyurethane resin composition according to claim 1, wherein the substituent capable of acting as a steric hindrance of the hindered phenolic antioxidant is a tert-butyl group. 4. The moisture-curable polyurethane resin composition according to claim 1, wherein the (meth) acrylic compound is a (meth) acrylic acid ester and / or a (meth) acrylic acid amide. . 5. The method according to claim 5, wherein the (meth) acrylic compound and the hindered phenolic antioxidant are each added in an amount of 0.01 to 100 parts by weight of the urethane prepolymer.
The moisture-curable polyurethane resin composition according to any one of claims 1 to 4, comprising 30 parts by weight.