JP7134424B2 - Curable composition - Google Patents

Description

The present invention relates to a curable composition that is cured by moisture in the atmosphere (air) to form a cured product having excellent weather resistance and flame retardancy.

A curable composition containing an oxyalkylene polymer having a crosslinkable hydrolyzable silyl group is conventionally known (for example, Patent Document 1). The curable composition produces a cured product with excellent adhesion by hydrolyzing the crosslinkable hydrolyzable silyl groups by moisture contained in the atmosphere and then dehydrating condensation.

As a curable composition, Patent Document 2 discloses an alkoxysilyl group-containing polyoxyalkylene polymer (A), a metal hydroxide powder (B) having an average particle size of 0.1 to 200 μm, and an average particle size of 0.1 μm. A flame-retardant, moisture-curable adhesive composition characterized by containing as essential components heavy calcium carbonate (C) having a particle size of 1 to 10 μm and an amide wax (D) is disclosed.

JP-A-2008-1833 JP 2010-285462 A

Such a curable composition is used, for example, in the outer walls of building structures, such as joints (so-called “joints”) between outer wall members such as mortar plates, concrete plates, ALC (Autoclaved Light-weight Concrete) plates, and metal plates. ) is used to join the outer wall members together. By using the curable composition in this way, it is possible to suppress the infiltration of rainwater into the inside of the building structure through the joints between the outer wall members.

In the outer wall of a building structure, the joint width changes slightly because the outer wall member expands or contracts due to temperature changes, or the outer wall member moves due to vibration or external force caused by an earthquake or strong wind. Therefore, the curable composition is required to have excellent rubber elasticity after curing and to be able to expand and contract so that it can follow changes in joint width. Furthermore, flame retardancy is desired.

However, in a conventional curable composition, when flame retardancy such as metal hydroxide powder is imparted, the rubber elasticity decreases and the composition becomes hard, and when the joint width changes, the composition does not follow the change in joint width. This makes it difficult to expand and contract, causing peeling at the adhesion interface and damage to the outer wall members, or cracking in the cured product of the curable composition, allowing rainwater to enter the building structure, There was a problem of water leakage.

Accordingly, an object of the present invention is to provide a curable composition that can maintain excellent rubber elasticity over a long period of time after curing while having flame retardancy.

The curable composition of the present invention comprises a polyalkylene oxide (A) having a hydrolyzable silyl group having a number average molecular weight (Mn) of 20,000 to 50,000 and a molecular weight distribution (Mw/Mn) of 1.2 or less; A hydrated metal compound (B), an aminosilane (C), a silanol condensation catalyst (D) and a plasticizer (E) are included, and the content ratio of the hydrated metal compound (B) to the plasticizer (E) [hydrated metal compound The mass of (B)/mass of plasticizer (E)] is 1.8-7.

[Polyalkylene oxide (A)]
The polyalkylene oxide (A) contained in the curable composition has hydrolyzable silyl groups. In the present invention, a hydrolyzable silyl group is a group in which 1 to 3 hydrolyzable groups are bonded to a silicon atom.

The hydrolyzable group of the hydrolyzable silyl group is not particularly limited. groups, alkenyloxy groups, and the like.

Among them, as the hydrolyzable silyl group, an alkoxysilyl group is preferable because the hydrolysis reaction is mild. Alkoxysilyl groups include trialkoxysilyl groups such as trimethoxysilyl group, triethoxysilyl group, triisopropoxysilyl group and triphenoxysilyl group; and monoalkoxysilyl groups such as dimethylmethoxysilyl and dimethylethoxysilyl groups. Among them, a dialkoxysilyl group is more preferable, and a methyldimethoxysilyl group is particularly preferable.

Polyalkylene oxide (A) preferably has an average of 1 to 2 hydrolyzable silyl groups per molecule. When the number of hydrolyzable silyl groups in the polyalkylene oxide (A) is 1 or more, the curability of the curable composition is improved. Moreover, when the number of hydrolyzable silyl groups in the polyalkylene oxide (A) is 2 or less, the mechanical strength or elongation of the cured product of the curable composition is improved. Moreover, the polyalkylene oxide (A) preferably has a hydrolyzable silyl group on at least one of both ends of its molecular chain.

The average number of hydrolyzable silyl groups per molecule in the polyalkylene oxide (A) is the concentration of the hydrolyzable silyl groups in the polyalkylene oxide (A) determined by ¹ H-NMR and GPC. It can be calculated based on the number average molecular weight of the polyalkylene oxide (A) determined by the law.

As the polyalkylene oxide (A), the main chain has the general formula: -(RO) _n - (wherein R represents an alkylene group having 1 to 14 carbon atoms, n is the number of repeating units is a positive integer.) is preferred. The main chain skeleton of the polyalkylene oxide may consist of one type of repeating unit, or may consist of two or more types of repeating units.

Examples of the main chain skeleton of the polyalkylene oxide (A) include polyethylene oxide, polypropylene oxide, polybutylene oxide, polytetramethylene oxide, polyethylene oxide-polypropylene oxide copolymer, and polypropylene oxide-polybutylene oxide copolymer. be done. Among them, polypropylene oxide is preferable. Polypropylene oxide can provide a curable composition that exhibits excellent rubber elasticity and adhesiveness after curing.

The polyalkylene oxide (A) has a number average molecular weight of 20,000 to 50,000, preferably 20,000 to 40,000. When the number average molecular weight of the polyalkylene oxide (A) is 20000 or more, the rubber elasticity of the cured product of the curable composition is improved. When the number average molecular weight of the polyalkylene oxide (A) is 50000 or less, the coatability of the curable composition is improved.

The molecular weight distribution (weight average molecular weight (Mw)/number average molecular weight (Mn)) of the polyalkylene oxide (A) is 1.2 or less. A polyalkylene oxide having a molecular weight distribution of 1.2 or less improves the rubber elasticity of the cured product of the curable composition.

In the present invention, the number average molecular weight of polyalkylene oxide (A) means a value measured by GPC (gel permeation chromatography) and converted to polystyrene.

Specifically, 6 to 7 mg of polyalkylene oxide is sampled, and the sampled polyalkylene oxide is supplied to a test tube. Prepare an ortho-dichlorobenzene (o-DCB) solution containing 0.05% by mass of dibutylhydroxytoluene (BHT), add this solution to a test tube, and dilute so that the concentration of polyalkylene oxide is 1 mg/mL. to prepare a diluted solution. Using a dissolution filtration device, the above diluted solution is shaken at 145° C. and a rotation speed of 25 rpm for 1 hour to dissolve the polyalkylene oxide in the solution to obtain a measurement sample. Using this measurement sample, the number average molecular weight of the polyalkylene oxide can be measured by the GPC method.

The number average molecular weight of polyalkylene oxide can be measured, for example, using the following measuring apparatus and measuring conditions.
Measuring device manufactured by TOSOH, trade name “HLC-8121GPC/HT”
Measurement conditions Column: TSKgelGMHHR-H (20) HT x 3
TSKguard column-HHR (30) HT x 1
Mobile phase: o-DCB 1.0 mL/min
Sample concentration: 1 mg/mL
Detector: Bryce refractometer
Standard substance: polystyrene (manufactured by TOSOH, molecular weight: 500 to 8420000)
Elution conditions: 145°C
SEC temperature: 145°C

A commercially available polyalkylene oxide (A) containing a hydrolyzable silyl group can be used. For example, as a polyalkylene oxide having a main chain skeleton of polypropylene oxide and having a methyldimethoxysilyl group at the end of the main chain skeleton, Asahi Glass Co., Ltd.'s product name "Exester S4530" can be mentioned.

[Hydrated metal compound (B)]
The curable composition comprises a hydrated metal compound. _The hydrated metal compound is not particularly limited _, and examples thereof include aluminum hydroxide [Al ₂ O _{3 .3H 2 O} ; magnesium oxide [MgO.H2O; or Mg(OH) ₂ ], calcium hydroxide [ _CaO.H2O ; or Ca ₍ OH) ₂ ], zinc hydroxide [Zn(OH) ₂ ], silicic acid [ _H4 SiO4; or _H2SiO3 ; or _H2Si2O5 ] _{, iron} hydroxide [ _Fe2O3.H2O or _{2FeO (} OH)] _, copper hydroxide [Cu ₍ OH) ₂ ], hydroxide barium [ _BaO.H2O ; or _BaO.9H2O ], zirconium oxide hydrate [ _ZrO.nH2O ], tin oxide hydrate [ _SnO.H2O ], basic magnesium carbonate [ _3MgCO3 . Mg ₍ OH) _2.3H2O ], _hydrotalcite [ _{6MgO.Al2O3.H2O} ] _{, dawsonite} [ _{Na2CO3.Al2O3.nH2O} ] _{, borax} [ _{Na2O . B2O5.5H2O ]} and _{zinc borate [ 2ZnO.3B2O5.3.5H2O} ]. As the hydrated metal compound, since the cured product of the curable composition has excellent flame retardancy, it preferably contains aluminum hydroxide and / or magnesium hydroxide. And it is more preferable to contain aluminum hydroxide because it has better rubber elasticity. The hydrated metal compound more preferably contains aluminum hydroxide and magnesium hydroxide because the cured product of the curable composition is excellent in flame retardancy and rubber elasticity.

When the hydrated metal compound contains aluminum hydroxide and magnesium hydroxide, the content ratio of aluminum hydroxide to magnesium hydroxide (mass of aluminum hydroxide/mass of magnesium hydroxide) is preferably 0.3 to 9. 0.5 to 6 are more preferred, and 1 to 4 are particularly preferred. When the content ratio of aluminum hydroxide to magnesium hydroxide (mass of aluminum hydroxide/mass of magnesium hydroxide) is 0.3 or more, the cured product of the curable composition has excellent flame retardancy. When the content ratio of aluminum hydroxide to magnesium hydroxide (mass of aluminum hydroxide/mass of magnesium hydroxide) is 9 or less, the cured product of the curable composition has excellent rubber elasticity.

The median particle size of the hydrated metal compound is preferably 1 to 100 μm, more preferably 3 to 50 μm, particularly preferably 4 to 15 μm. When the median particle size is 1 μm or more, the hydrated metal compound can be finely dispersed, which is preferable. When the median particle size is 100 μm or less, the curable composition forms a cured product having excellent flame retardancy. The median particle size of the hydrated metal compound refers to a value measured by a laser diffraction method.

The content of the hydrated metal compound in the curable composition is preferably 140 to 500 parts by mass, more preferably 210 to 400 parts by mass, per 100 parts by mass of the polyalkylene oxide (A). When the content of the hydrated metal compound is 140 parts by mass or more, the cured product of the curable composition has excellent flame retardancy. When the content of the hydrated metal compound is 500 parts by mass or less, the curable composition has excellent curability.

[Aminosilane compound (C)]
The curable composition contains an aminosilane compound. Aminosilane compounds are specifically 3-aminopropyltrimethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, N,N'-bis-[3-(trimethoxysilyl)propyl]ethylenediamine, N,N'-bis-[3-(triethoxysilyl ) propyl]ethylenediamine, N,N'-bis-[3-(methyldimethoxysilyl)propyl]ethylenediamine, N,N'-bis-[3-(trimethoxysilyl)propyl]hexamethylenediamine, N,N'- bis-[3-(triethoxysilyl)propyl]hexamethylenediamine and the like, preferably N-(2-aminoethyl)-3-aminopropyltrimethoxysilane. The aminosilane compound (C) may be used alone or in combination of two or more. The aminosilane compound (C) may be the monomers shown above or hydrolytic condensates of these monomers. In particular, the aminosilane compound (C) is preferably an alkoxysilane oligomer which is a hydrolytic condensate of an alkylalkoxysilane and an aminoalkoxysilane. That is, the curable composition preferably contains an alkoxysilane oligomer obtained by hydrolyzing and then condensing an alkylalkoxysilane and an aminoalkoxysilane.

The viscosity of the aminosilane compound (C) at 20° C. is preferably 1 to 200 mPa·s, more preferably 5 to 100 mPa·s. The viscosity of the aminosilane compound (C) at 20°C is a value measured according to JIS Z8803.

In the alkoxysilane oligomer, which is a hydrolytic condensate of alkylalkoxysilane and aminoalkoxysilane, the content of nitrogen atoms is preferably 1% by mass or more, more preferably 3% by mass or more, and particularly preferably 5% by mass or more. When the nitrogen atom content is 1% by mass or more, the adhesion of the curable composition is excellent, and the cured product of the curable composition is excellent in rubber elasticity and flame retardancy, which is preferable. The upper limit of the nitrogen atom content is not particularly limited, but is preferably 20% by mass or less, more preferably 10% by mass or less. When the nitrogen atom content is 20% by mass or less, the cured product of the curable composition maintains excellent rubber elasticity even after reaching a high temperature, which is preferable. The content of nitrogen atoms in the alkoxysilane oligomer refers to a value measured based on CHN elemental analysis.

Alkylalkoxysilane means a compound in which at least one alkyl group and at least two alkoxy groups are bonded directly to a silicon atom. Alkylalkoxysilanes are preferably monoalkyltrialkoxysilanes in which one alkyl group and three alkoxy groups are directly bonded to a silicon atom. Specific examples of alkylalkoxysilanes include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, and hexyltrimethoxysilane, with ethyltriethoxysilane being preferred.

Aminoalkoxysilane means a compound having at least one amino group-containing functional group in one molecule and at least two alkoxy groups directly bonded to a silicon atom. The amino group-containing functional group is preferably directly bonded to the silicon atom. The aminoalkoxysilane is preferably a compound having one amino group-containing functional group in one molecule and three alkoxy groups directly bonded to a silicon atom.

As the amino group-containing functional group, an aminopropyl functional group is preferable because it improves the adhesiveness of the curable composition. Aminopropyl functional groups include -(CH ₂ ) ₃ -NH ₂ , -(CH ₂ ) ₃ -NHR, -(CH ₂ ) ₃ -NH(CH ₂ ) ₂ -NH ₂ (3-[N-(2 -aminoethyl)amino]propyl group) and -(CH ₂ ) ₃ -NH(CH ₂ ) ₂ -NH(CH ₂ ) ₂ -NH ₂ (3-[[2-(2-aminoethylamino)ethyl ]amino]propyl groups) are preferred. More preferred aminopropyl functional groups are --(CH ₂ ) ₃ --NH ₂ and --(CH ₂ ) ₃ --NH(CH ₂ ) ₂ --NH ₂ .

In —(CH ₂ ) ₃ —NHR, R is an alkyl group having 1 to 18 carbon atoms, a monovalent saturated alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a 12 aryl groups.

Examples of alkyl groups having 1 to 18 carbon atoms include straight-chain alkyl groups and branched-chain alkyl groups. Linear alkyl groups include, for example, methyl group, ethyl group, propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group and the like. Preferred linear alkyl groups are methyl, ethyl and n-butyl groups. Examples of branched chain alkyl groups include isopropyl, isobutyl, sec-butyl and tert-butyl groups.

Examples of monovalent saturated alicyclic hydrocarbon groups having 3 to 18 carbon atoms include cyclopentyl group, cycloheptyl group, cyclohexyl group, 4-methylcyclohexyl group, cyclooctyl group and the like, and cyclohexyl group is preferable.

The aryl group having 6 to 12 carbon atoms includes, for example, a phenyl group and a benzyl group, with a phenyl group being preferred.

Specific examples of aminoalkoxysilanes include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-methyl-aminopropyltrimethoxysilane, N-methyl-aminopropyltriethoxysilane, Nn -butyl-aminopropyltrimethoxysilane, Nn-butyl-aminopropyltriethoxysilane, N-cyclohexylaminopropyltrimethoxysilane, N-cyclohexylaminopropyltriethoxysilane, N-phenyl-aminopropyltrimethoxysilane, N -phenyl-aminopropyltriethoxysilane, 3-[N-(2-aminoethyl)amino]propyltrimethoxysilane, 3-[N-(2-aminoethyl)amino]propyltriethoxysilane, [3-[2 -(2-aminoethylamino)ethylamino]propyl]trimethoxysilane, [3-[2-(2-aminoethylamino)ethylamino]propyl]triethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-amino Propylmethyldiethoxysilane, N-methyl-aminopropylmethyldimethoxysilane, N-methyl-aminopropylmethyldiethoxysilane, Nn-butyl-aminopropylmethyldimethoxysilane, Nn-butyl-aminopropylmethyldiethoxysilane Silane, N-cyclohexylaminopropylmethyldimethoxysilane, N-cyclohexylaminopropylmethyldiethoxysilane, N-phenyl-aminopropylmethyldimethoxysilane, N-phenyl-aminopropylmethyldiethoxysilane, 3-[N-(2- aminoethyl)amino]propylmethyldimethoxysilane, 3-[N-(2-aminoethyl)amino]propylmethyldiethoxysilane, [3-[2-(2-aminoethylamino)ethylamino]propyl]methyldimethoxysilane , [3-[2-(2-aminoethylamino)ethylamino]propyl]methyldiethoxysilane, N,N'-bis-[3-(trimethoxysilyl)propyl]ethylenediamine, N,N'-bis- [3-(triethoxysilyl)propyl]ethylenediamine, N,N'-bis-[3-(methyldimethoxysilyl)propyl]ethylenediamine, N,N'-bis-[3-(trimethoxysilyl)propyl]hexamethylene diamine, and N,N'-bis-[3-(triethoxysilyl)propyl]hexamethylene diamine amines and the like. As the aminoalkoxysilane, 3-[N-(2-aminoethyl)amino]propyltrimethoxysilane, 3-[N-(2-aminoethyl)amino]propyltriethoxysilane are preferred, and 3-[N-( 2-Aminoethyl)amino]propyltriethoxysilane is more preferred.

The alkoxysilane oligomer is preferably a hydrolytic condensate of a monoalkyltrialkoxysilane and an aminoalkoxysilane in which one aminopropyl functional group and three alkoxy groups are directly bonded to the silicon atom.

The alkoxysilane oligomer is preferably a hydrolytic condensate of monoalkyltrialkoxysilane and 3-[N-(2-aminoethyl)amino]propyltrialkoxysilane.

The alkoxysilane oligomer is preferably a hydrolytic condensate of monoalkyltriethoxysilane and 3-[N-(2-aminoethyl)amino]propyltrialkoxysilane.

The alkoxysilane oligomer is particularly preferably a hydrolytic condensate of monoalkyltrialkoxysilane and 3-[N-(2-aminoethyl)amino]propyltriethoxysilane.

A particularly preferred alkoxysilane oligomer is a hydrolytic condensate of ethyltriethoxysilane and 3-[N-(2-aminoethyl)amino]propyltriethoxysilane.

An alkoxysilane oligomer is obtained by hydrolyzing an alkoxy group of an alkylalkoxysilane and an alkoxy group of an aminoalkoxysilane to form a silanol group, and then condensing these silanol groups. The silanol group means a hydroxy group (≡Si—OH) directly bonded to a silicon atom.

The alkoxysilane oligomer preferably has an aminopropyl functional group. Alkoxysilane oligomers are -(CH ₂ ) ₃ -NH ₂ , -(CH ₂ ) ₃ -NHR, -(CH ₂ ) ₃ -NH(CH ₂ ) ₂ -NH ₂ (3-[N-(2-amino ethyl)amino]propyl) and —(CH ₂ ) ₃ —NH(CH ₂ ) ₂ —NH(CH ₂ ) ₂ —NH ₂ (3-[[2-(2-aminoethylamino)ethyl]amino ] propyl group). It is particularly preferred that the alkoxysilane oligomer has --(CH ₂ ) ₃ --NH(CH ₂ ) ₂ --NH ₂ .

Moreover, an alkoxysilane oligomer can use what is marketed. For example, Evonik Dexsa's product name "Dynasilane 1146" can be used.

The content of the aminosilane compound (C) in the curable composition is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, with respect to 100 parts by mass of the polyalkylene oxide (A). 1 to 3 parts by weight is particularly preferred. When the content of the aminosilane compound (C) is 0.1 parts by mass or more, the adhesiveness of the curable composition is improved. When the content of the aminosilane compound (C) is 10 parts by mass or less, the curability of the curable composition is improved.

[Silanol condensation catalyst (D)]
The curable composition contains a silanol condensation catalyst (D). The silanol condensation catalyst (D) refers to hydrolyzable silyl groups contained in the polyalkylene oxide (A) and silanol groups formed by hydrolyzing the alkoxysilyl groups contained in the aminosilane compound (C). is a catalyst for promoting the dehydration condensation reaction of

The silanol condensation catalyst (D) is not particularly limited. Tin diacetate, dibutyltin phthalate, bis(dibutyltin laurate) oxide, dibutyltin bis(acetylacetonate), dibutyltin bis(monoester maleate), tin octoate, dibutyltin octoate, dioctyltin oxide, dibutyltin Organotin compounds such as bis(triethoxysilicate), bis(dibutyltin bistriethoxysilicate) oxide, and dibutyltinoxybisethoxysilicate; organotitanium compounds such as tetra-n-butoxytitanate and tetraisopropoxytitanate; Organic tin compounds are preferred, and dioctyltin monodecanate is more preferred. These silanol condensation catalysts may be used alone or in combination of two or more.

The content of the silanol condensation catalyst (D) in the curable composition is preferably 1 to 10 parts by mass, more preferably 1 to 5 parts by mass, per 100 parts by mass of the polyalkylene oxide (A). When the content of the silanol condensation catalyst in the curable composition is 1 part by mass or more, the curing speed of the curable composition can be increased, and the time required for curing the curable composition can be shortened. . Further, when the content of the silanol condensation catalyst in the curable composition is 10 parts by mass or less, the curable composition has an appropriate curing rate, and the storage stability and handling properties of the curable composition are improved. be able to.

[Plasticizer (E)]
The curable composition contains a plasticizer. As the plasticizer, a compound having a molecular weight of 300 to 10,000 is used except for polymers and oligomers. In the case of polymers and oligomers, polymers having a weight average molecular weight of 400 to 11,000 are used as plasticizers. Specific examples include phthalate esters such as dioctyl phthalate, dibutyl phthalate, and butylbenzyl phthalate, polyalkylene oxides such as polypropylene glycol, and acrylic polymers, with acrylic polymers being preferred. The acrylic polymer preferably contains at least an acrylic polymer containing no hydrolyzable silyl group. In order to prevent deterioration of rubber elasticity over time, the acrylic polymer may contain a hydrolyzable silyl group, and the average number of hydrolyzable silyl groups per molecule is 0.1 to 0.5. It preferably contains Also, the weight average molecular weight of the acrylic polymer is preferably 500 to 10,000, more preferably 1,000 to 5,000. Bleeding out of the acrylic polymer can be suppressed when the weight average molecular weight of the acrylic polymer is 500 or more. Also, the acrylic polymer has a weight average molecular weight of 10,000 or less. The curable composition is sufficiently plasticized so that the cured product of the curable composition has excellent rubber elasticity.

In the curable composition, the content ratio of the hydrated metal compound (B) and the plasticizer (E) [mass of the hydrated metal compound (B)/mass of the plasticizer (E)] is 1.8 to 7. , preferably 3 to 6.5, more preferably 4 to 6. When the content ratio of the hydrated metal compound (B) to the plasticizer (E) [mass of the hydrated metal compound (B)/mass of the plasticizer (E)] is 1.8 or more, the plasticizer bleeds out. can be suppressed, and contamination of the cured product of the curable composition can be suppressed. When the content ratio of the hydrated metal compound (B) to the plasticizer (E) [mass of the hydrated metal compound (B)/mass of the plasticizer (E)] is 7 or less, the curable composition is excellent. Excellent rubber elasticity can be maintained for a long period of time while having excellent flame retardancy.

The content of the plasticizer (E) in the curable composition is preferably 100 parts by mass or less, more preferably 70 parts by mass or less, with respect to 100 parts by mass of the polyalkylene oxide (A), and 1 to 70 parts by mass. Especially preferred. When the content of the plasticizer (E) in the curable composition is 100 parts by mass or less, bleeding out of the plasticizer can be suppressed, and contamination of the cured product of the curable composition can be suppressed.

[Glass frit (F)]
The curable composition contains glass frit (glass powder) (F). By containing the glass frit (F), the cured product of the curable composition has excellent flame retardancy and rubber elasticity.

Examples of the glass constituting the glass frit (F) include phosphate glass, boric acid glass, bismuth oxide glass, silicate glass, sodium oxide glass, and the like. Acid-based glass is preferred, and phosphate-based glass is more preferred. These glass frits _are B2O3 _, P2O5, ZnO, _SiO2 , _{Bi2O3 , Al2O3 ,} BaO, CaO, _MgO , _MnO2 , _ZrO2 , _TiO2 , _CeO2 , _SrO , V ₂ O ₅ , SnO ₂ , Li ₂ O, Na ₂ O, K ₂ O, CuO, Fe ₂ O ₃ and the like can be adjusted at predetermined component ratios.

The softening point of the glass constituting the glass frit (F) is preferably 350 to 650°C, more preferably 360 to 560°C, particularly preferably 370 to 540°C, most preferably 380 to 520°C. The softening point of the glass forming the glass frit (F) is the temperature at which the viscosity of the glass becomes 107.6 dPa·s (log η=7.6).

The content of the glass frit (F) in the curable composition is preferably 100 parts by mass or less with respect to 100 parts by mass of the polyalkylene oxide (A), more preferably 50 parts by mass or less, and particularly 10 to 40 parts by mass. preferable. When the content of the glass frit (F) is 100 parts by mass or less, the cured product of the curable composition has excellent flame retardancy and rubber elasticity over a long period of time.

[filler]
Preferably, the curable composition further comprises a filler. A filler can provide a curable composition capable of obtaining a cured product having excellent mechanical strength.

Examples of fillers include calcium carbonate, magnesium carbonate, calcium oxide, hydrous silicic acid, anhydrous silicic acid, finely powdered silica, calcium silicate, titanium dioxide, clay, talc, carbon black, and glass balloons. Calcium carbonate is preferred, and colloidal calcium carbonate and ground calcium carbonate are preferred. These fillers may be used alone or in combination of two or more.

The average particle size of calcium carbonate is preferably 0.01-5 μm, more preferably 0.05-2.5 μm. Calcium carbonate having such an average particle size makes it possible to obtain a cured product having excellent mechanical strength and elongation, and to obtain a curable composition having excellent adhesiveness. can provide.

Moreover, calcium carbonate is preferably surface-treated with a fatty acid, a fatty acid ester, or the like. Calcium carbonate surface-treated with fatty acid, fatty acid ester, or the like can impart thixotropic properties to the curable composition and can suppress aggregation of calcium carbonate.

The content of the filler in the curable composition is preferably 1-700 parts by mass, more preferably 10-200 parts by mass, per 100 parts by mass of the polyalkylene oxide (A). When the content of the filler in the curable composition is 1 part by mass or more, the effect of adding the filler can be sufficiently obtained. Moreover, when the content of the filler in the curable composition is 700 parts by mass or less, the cured product obtained by curing the curable composition has excellent rubber elasticity.

[Dehydrating agent]
Preferably, the curable composition further contains a dehydrating agent. The dehydrating agent can suppress curing of the curable composition due to moisture contained in the air or the like during storage of the curable composition.

Dehydrating agents include silane compounds such as vinyltrimethoxysilane, dimethyldimethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, phenyltrimethoxysilane, and diphenyldimethoxysilane; and methyl orthoformate. , ethyl orthoformate, methyl orthoacetate, and ester compounds such as ethyl orthoacetate. These dehydrating agents may be used alone or in combination of two or more. Among them, vinyltrimethoxysilane is preferred.

The content of the dehydrating agent in the curable composition is preferably 0.5 to 20 parts by mass, more preferably 1 to 15 parts by mass, per 100 parts by mass of the polyalkylene oxide (A). When the content of the dehydrating agent in the curable composition is 0.5 parts by mass or more, the effect obtained by the dehydrating agent can be sufficiently obtained. Moreover, when the content of the dehydrating agent in the curable composition is 20 parts by mass or less, the curable composition has excellent curability.

[Light stabilizer]
The curable composition preferably further contains a light stabilizer, more preferably a hindered amine light stabilizer. A hindered amine light stabilizer can provide a curable composition that can maintain excellent rubber elasticity over a long period of time after curing.

Hindered amine light stabilizers include, for example, a mixture of bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate , bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, dibutylamine/1,3,5-triazine/N,N'-bis(2,2,6,6-tetramethyl-4 - polycondensation product of piperidyl-1,6-hexamethylenediamine and N-(2,2,6,6-tetramethyl-4-piperidyl)butylamine, poly[{6-(1,1,3,3- tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene {(2,2,6,6 -tetramethyl-4-piperidyl)imino}], polycondensates of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, and the like.

The content of the hindered amine light stabilizer in the curable composition is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, based on 100 parts by mass of the polyalkylene oxide (A).

[Other additives]
The curable composition may contain other additives such as thixotropic agents, antioxidants, UV absorbers, pigments, dyes, anti-settling agents, and solvents. Among them, thixotropy-imparting agents, ultraviolet absorbers, and antioxidants are preferred.

The thixotropy-imparting agent may be any agent capable of imparting thixotropy to the curable composition. Preferred examples of the thixotropic agent include hydrogenated castor oil, fatty acid bisamide, and fumed silica.

The content of the thixotropic agent in the curable composition is preferably 0.1 to 200 parts by mass, more preferably 1 to 150 parts by mass, based on 100 parts by mass of the polyalkylene oxide (A). When the content of the thixotropic agent in the curable composition is 0.1 parts by mass or more, thixotropic properties can be effectively imparted to the curable composition. Moreover, when the content of the thixotropy-imparting agent in the curable composition is 200 parts by mass or less, the curable composition has an appropriate viscosity and the handleability of the curable composition is improved.

Examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, and the like, and benzotriazole-based ultraviolet absorbers are preferred. The content of the ultraviolet absorber in the curable composition is preferably 0.1 to 20 parts by weight with respect to a total of 100 parts by weight of the polyalkylene oxide (A) and the acrylic polymer (B), and 0.1 ~10 parts by mass is more preferable.

Examples of antioxidants include hindered phenol-based antioxidants, monophenol-based antioxidants, bisphenol-based antioxidants, and polyphenol-based antioxidants, with hindered phenol-based antioxidants being preferred. be done. The content of the antioxidant in the curable composition is preferably 0.1 to 20 parts by mass, more preferably 0.3 to 10 parts by mass, per 100 parts by mass of the polyalkylene oxide (A).

The curable composition comprises a polyalkylene oxide (A), a hydrated metal compound (B), an aminosilane compound (C), a silanol condensation catalyst (D) and a plasticizer (E), and, if necessary, additives in a stirrer. It can be produced by mixing until uniform, preferably under reduced pressure.

The curable composition has excellent flame retardancy, excellent adhesiveness, and can form a cured product that can maintain excellent rubber elasticity for a long period of time. It can be used for various applications such as materials, coating materials, adhesives, and paints. Among others, it is preferably used as a sealant, and more preferably used as a joint structural sealant.

As a method for obtaining a joint structure by applying the curable composition to the joint, a method is used in which the joint is filled with the curable composition and then cured to harden. The resulting joint structure has a wall member that constitutes the wall of the building structure, and a cured product of the curable composition that fills the joint formed between the adjacent wall members. there is Walls of building structures include, for example, outer walls, inner walls, and ceilings. Examples of the wall member include an outer wall member, an inner wall member, and a ceiling member.

The joints are not particularly limited, but examples include joints in outer walls, inner walls, and ceilings of building structures. Since the curable composition of the present invention can maintain excellent rubber elasticity for a long period of time after curing, it can be cured by expansion or contraction of the member due to temperature changes such as air temperature or sunlight, or by the action of vibration, wind pressure, or the like. It exhibits excellent followability to changes in the width of the joint due to erosion, and can prevent damage to members and water leakage into the building structure. Therefore, it can be suitably used for sealing joints, so-called "working joints", where the width varies greatly, such as joints in the outer walls of building structures.

Joints in the outer walls of building structures include, for example, joints formed between outer wall members such as mortar plates, concrete plates, ceramic siding boards, metal siding boards, ALC plates, and metal plates. .

Since the curable composition of the present invention has the structure as described above, it has excellent adhesiveness, excellent flame retardancy, and maintains excellent rubber elasticity for a long period of time. It is possible to form a cured product that can be.

EXAMPLES The present invention will be described in more detail below using examples, but the present invention is not limited to these.

The following compounds were used in Examples and Comparative Examples.
[Polyalkylene oxide (A)]
Polyalkylene oxide (A1) containing a methyldimethoxysilyl group and having a main chain skeleton composed of polypropylene oxide (manufactured by Asahi Glass Co., Ltd., product name “Excester S4530”, number average molecular weight (Mn): 25000, molecular weight distribution (Mw / Mn ): 1.16)
Polyalkylene oxide containing no hydrolyzable silyl group (A2) (product name “Excester S2420” manufactured by Asahi Glass Co., Ltd., number average molecular weight (Mn): 20000, molecular weight distribution (Mw/Mn): 1.49)
[Hydrated metal compound (B)]
Aluminum hydroxide (B1) (trade name “C-305” manufactured by Sumitomo Chemical Co., Ltd., central particle size: 5.5 μm)
Magnesium hydroxide (B2) (manufactured by Kojima Kagaku Kogyo Co., Ltd., trade name “Magshees N”, central particle size: 1.1 μm)
[Aminosilane compound (C)]
Alkoxysilane oligomer (C1) (hydrolytic condensate of ethyltriethoxysilane and 3-[N-(2-aminoethyl)amino]propyltriethoxysilane, nitrogen atom content: 6% by mass, viscosity (20° C. ): 20 mPa s, manufactured by Evonik Degussa Japan, product name “Dynasilane 1146”)
Aminosilane compound (C2) (N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., product name “KBM-603”)
[Silanol condensation catalyst (D)]
Silanol condensation catalyst (D) (dioctyltin monodecanate, manufactured by Nitto Kasei Co., Ltd., product name “Neostan U-830”)
[Plasticizer (E)]
Plasticizer (E1) (polypropylene oxide, weight average molecular weight: 3000, product name “Exester 3020” manufactured by Asahi Glass Co., Ltd.)
Plasticizer (E2) (acrylic polymer containing no hydrolyzable silyl group, weight average molecular weight: 2000, product name “UP1110” manufactured by Toagosei Co., Ltd.)
[Glass frit (F)]
Glass frit (F) (phosphoric acid glass, glass softening point: 404 ° C., trade name “VYO144” manufactured by Nihon Frit Co., Ltd.)
〔filler〕
Colloidal calcium carbonate (manufactured by Kojima Chemical Co., Ltd. product name “PLS-505”, average particle size: 0.1 μm)
Heavy calcium carbonate (manufactured by Nitto Funka Kogyo Co., Ltd., product name “NCC2310”, average particle size: 1.0 μm)
[Dehydrating agent]
Vinyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., product name “KBM-1003”)
[Ultraviolet absorber]
Benzotriazole-based UV absorber (manufactured by BASF Japan, product name “Tinuvin 326”)
〔Antioxidant〕
Hindered phenolic antioxidant (manufactured by BASF Japan, product name “Irganox 1010”)
[Light stabilizer]
NH-type hindered amine light stabilizer (manufactured by BASF Japan, product name “Tinuvin 770”)

(Examples 1 to 13 and Comparative Examples 1 to 4 )
The above-mentioned polyalkylene oxide (A), hydrated metal compound (B), aminosilane compound (C), silanol condensation catalyst (D), plasticizer (E), glass frit (F), filler, dehydrating agent, ultraviolet rays A curable composition was obtained by mixing the absorber, the antioxidant and the light stabilizer in the respective amounts shown in Table 1 in a sealed stirrer while reducing the pressure until uniform.

[Elongation at maximum load]
Using the curable composition, an H-type specimen was produced according to JIS A1439 4.21. Specifically, two aluminum plates (50 mm long x 50 mm wide x 3 mm thick) that have been anodized are used, and a space (vertical 12 mm x 50 mm wide x 12 mm high). This space was filled with the curable composition in such a manner that no air entered. After filling the curable composition, the curable composition was allowed to stand for 14 days in an atmosphere of 23° C. and 50% relative humidity. After that, the curable composition was further left for 14 days in an atmosphere at a temperature of 30°C. By curing and curing the curable composition, an H-shaped specimen was produced in which two aluminum plates were bonded and integrated by the cured product of the curable composition.

Then, the H-shaped specimen immediately after preparation was subjected to a tensile test at a tensile speed of 50 mm / min in an atmosphere of 23 ° C. and a relative humidity of 50% in accordance with JIS A1439, and the elongation at maximum load [%] was measured. did. The results obtained are shown in the "Initial" column in Table 1, respectively.
As a durability evaluation, the H-shaped specimen immediately after production was exposed to an atmosphere of 80° C. for 90 days, and then left to stand in an atmosphere of 23° C. and a relative humidity of 50% for an additional 24 hours. Elongation at maximum load [%] was measured in the same manner as above. The obtained results are described in the column of "after heat resistance" in Table 1, respectively.

[Flame retardant evaluation]
The flame retardancy of the curable composition was measured according to UL94-VO rating. Specifically, the curable composition was molded into a sheet having a thickness of 2 mm to prepare a sheet, and this sheet was left in an atmosphere of 23° C. and 50% relative humidity for one month. A test sheet was prepared by curing and curing the curable composition. Five test sheets were prepared as described above.

The test sheet was held vertically, and a gas burner flame was applied to the lower end of the test sheet for 10 seconds. If the burning ceased within 30 seconds, the bottom edge of the test sheet was also exposed to the flame of the gas burner for an additional 10 seconds.
(criterion)
As a V-0 evaluation, "○" if any of the following conditions (1) to (5) are satisfied, and "X" if none of the following conditions (1) to (5) are satisfied "
(1) None of the five test sheets can continue to burn for more than 10 seconds after contact with the flame.
(2) The total burning time of 10 flame contact times of 5 test sheets does not exceed 50 seconds.
(3) No test sheet burned up to the position of the fixing clamp.
(4) There is no test sheet to drop burning particles that ignite the absorbent cotton placed underneath the test sheet.
(5) No test sheet continues to glow red for more than 30 seconds after the second flame application.

As a V-1 evaluation, "○" if any of the following conditions (1) to (5) are satisfied, and "×" if none of the following conditions (1) to (5) are satisfied "
(1) None of the five test sheets can continue to burn for more than 10 seconds after contact with the flame.
(2) The total burning time of 10 flame contact times of 5 test sheets does not exceed 250 seconds.
(3) No test sheet burned up to the position of the fixing clamp.
(4) There is no test sheet to drop burning particles that ignite the absorbent cotton placed underneath the test sheet.
(5) No test sheet continues to glow red for more than 60 seconds after the second flame application.

As a V-2 evaluation, "○" if any of the following conditions (1) to (5) are satisfied, and "X" if none of the following conditions (1) to (5) are satisfied "
(1) None of the five test sheets can continue to burn for more than 10 seconds after contact with the flame.
(2) The total burning time of 10 flame contact times of 5 test sheets does not exceed 250 seconds.
(3) No test sheet burned up to the position of the fixing clamp.
(4) A falling burning particle is allowed to ignite cotton wool placed under the test sheet.
(5) No test sheet continues to glow red for more than 60 seconds after the second flame application.

Claims (4)

100 parts by mass of a polyalkylene oxide (A) having a hydrolyzable silyl group having a number average molecular weight (Mn) of 20000 to 50000 and a molecular weight distribution (Mw/Mn) of 1.2 or less, aluminum hydroxide and/ or 200 to 400 parts by mass of a hydrated metal compound (B) containing magnesium hydroxide, and 0.1 to 10 parts by mass of an aminosilane compound (C) containing an alkoxysilane oligomer which is a hydrolytic condensate of an alkylalkoxysilane and an aminoalkoxysilane. , 1 to 10 parts by mass of a silanol condensation catalyst (D), and an acrylic polymer having a weight average molecular weight of 400 to 11,000 and containing no hydrolyzable silyl group or a polyalkylene having a weight average molecular weight of 400 to 11,000 30 to 100 parts by mass of a plasticizer (E) containing an oxide is included, and the content ratio of the hydrated metal compound (B) and the plasticizer (E) [mass of the hydrated metal compound (B) / the amount of the plasticizer (E) mass] of 3 to 7. 2. The curable composition of claim 1, wherein the hydrated metal compound (B) comprises aluminum hydroxide and magnesium hydroxide. 3. The curable composition according to claim 1, further comprising 10 to 50 parts by mass of glass frit with respect to 100 parts by mass of the polyalkylene oxide (A). 4. The curable composition according to any one of claims 1 to 3, characterized by containing 10 to 200 parts by weight of calcium carbonate as a filler with respect to 100 parts by weight of the polyalkylene oxide (A).