JP2022176924A - Curable composition - Google Patents

Abstract

To provide a curable composition to be cured by humidity in an atmosphere (air) or a member such as an external wall member, excellent in anti-fouling property, and generating a cured product that can retain rubber elasticity excellent in a high temperature atmosphere for a long period.SOLUTION: A curable composition contains: an organic polymer (A) having a hydrolyzable silyl group; a mineral (B) containing aluminum silicate; and a (meth)acrylic acid ester-based polymer (C) containing a (meth)acrylic acid ester unit having a polyethylene oxide chain.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a curable composition that cures with moisture to form a cured product that is excellent in both antifouling properties and heat-resistant rubber elasticity.

A curable composition containing a polyoxyalkylene polymer having a crosslinkable hydrolyzable silyl group is conventionally known. The curable composition produces a cured product with excellent adhesiveness by hydrolyzing the crosslinkable hydrolyzable silyl groups by the atmosphere or moisture contained in the building member or the like, followed by dehydration condensation.

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 as to adhere firmly to the outer wall and follow changes in joint width.

Patent Document 1 discloses a hydrolytic condensate of a polyalkylene oxide (A) having a hydrolyzable silyl group, an acrylic polymer (B) having a hydrolyzable silyl group, an alkylalkoxysilane and an aminoalkoxysilane. and an alkoxysilane oligomer (C) having a nitrogen atom content of 1% by weight or more.

Patent Document 2 discloses a curable composition containing a vinyl polymer having a reactive silicon group and an amine compound having a specific structural formula.

WO2014/175358 JP 2009-120730 A

However, the cured products of the curable compositions of Patent Documents 1 and 2 have a problem of low heat resistance. On the middle and upper floors of collective housing, the temperature rise due to sunlight is large, and if the heat resistance of the cured product of the curable composition is low, the rubber elasticity of the cured product of the curable composition decreases over time, and the joints between the outer wall members It becomes difficult for the cured product to expand and contract following the change in width. When the rubber elasticity of the cured product of the curable composition is lowered in this way, the cured product of the curable composition may peel off from the adhesion interface with the outer wall member, or the outer wall member may be damaged, resulting in rainwater flowing into the building. Problems such as infiltration into structures and causing water leakage arise.

Moreover, the cured products of the curable compositions of Patent Documents 1 and 2 have a problem of low antifouling properties. When the antifouling property is low, rain streak stains occur over time on the surface of the cured product of the curable composition. Rain streak stains are caused by streak-like traces left on the surface of the cured product of the curable composition where rainwater runs down after it rains. Rain streak stains often remain as black or white streaky marks. When rain streak stains occur, the surface of the cured product of the curable composition has a difference between the areas where rain streak stains have occurred and the areas where rain streak stains have not occurred, resulting in poor appearance. Therefore, the curable composition is required to have excellent antifouling properties so as to reduce the occurrence of rain streak stains after curing and maintain a beautiful appearance.

The present invention is hardened by the atmosphere (air) or moisture in members such as outer wall members, and has excellent antifouling properties (stain resistance), and also exhibits excellent rubber elasticity over a long period of time even in a high temperature atmosphere. Provided is a curable composition that produces a cured product that can maintain its elasticity (heat-resistant rubber elasticity).

The curable composition of the present invention is
an organic polymer (A) having a hydrolyzable silyl group;
a mineral (B) containing aluminum silicate;
and a (meth)acrylic acid ester-based polymer (C) containing a (meth)acrylic acid ester unit having a polyethylene oxide chain

[Organic polymer (A) having a hydrolyzable silyl group]
The curable composition contains an organic polymer (A) having hydrolyzable silyl groups. In the organic polymer (A) containing a hydrolyzable silyl group, the hydrolyzable group of the hydrolyzable silyl group is hydrolyzed to form a silanol group (--SiOH) in the presence of water. Then, the silanol groups undergo dehydration condensation to form a crosslinked structure. Incidentally, the organic polymer (A) having a hydrolyzable silyl group may be simply referred to as "organic polymer (A)".

The organic polymer (A) having a hydrolyzable silyl group is not particularly limited. a silicone resin having a hydrolyzable silyl group, a urethane resin having a hydrolyzable silyl group, a polyolefin resin having a hydrolyzable silyl group, polyalkylene oxide having a hydrolyzable silyl group, and acrylic resin having a hydrolyzable silyl group. based polymers are preferred. The organic polymer (A) having a hydrolyzable silyl group preferably contains a polyalkylene oxide having a hydrolyzable silyl group. The polyalkylene oxide having a hydrolyzable silyl group improves the durability of the cured product of the curable composition, thereby allowing the cured product to maintain excellent heat resistant rubber elasticity for a longer period of time. can. The organic polymer (A) having a hydrolyzable silyl group may contain a polyalkylene oxide (A1) having a hydrolyzable silyl group and an acrylic polymer (A2) having a hydrolyzable silyl group. preferable. The organic polymer (A) having a hydrolyzable silyl group contains a polyalkylene oxide (A1) having a hydrolyzable silyl group and an acrylic polymer (A2) having a hydrolyzable silyl group. With this, the durability of the cured product of the curable composition is further improved, whereby the cured product can maintain excellent heat resistant rubber elasticity for a longer period of time. The organic polymer (A) having a hydrolyzable silyl group may be used alone or in combination of two or more.

Total content of polyalkylene oxide having a hydrolyzable silyl group (A1) and acrylic polymer having a hydrolyzable silyl group (A2) in the organic polymer having a hydrolyzable silyl group (A) is preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, more preferably 95% by mass or more, more preferably 99% by mass or more, more preferably 100% by mass % is more preferred.

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, an alkoxysilyl group is preferable as the hydrolyzable silyl group of the organic polymer (A) 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.

The organic polymer (A) having a hydrolyzable silyl group preferably has 1 to 2 hydrolyzable silyl groups per molecule on average. When the number of hydrolyzable silyl groups in the organic polymer (A) having a hydrolyzable silyl group is 1 or more, the curability of the curable composition is improved. Further, when the number of hydrolyzable silyl groups in the organic polymer (A) having a hydrolyzable silyl group is 2 or less, the mechanical strength or heat resistant rubber elasticity of the cured product of the curable composition is improved. Moreover, the organic polymer (A) having a hydrolyzable silyl group preferably has a hydrolyzable silyl group at least one of both ends of its molecular chain.

The average number of hydrolyzable silyl groups per molecule in the organic polymer (A) having a hydrolyzable silyl group is the hydrolyzability in the organic polymer (A) determined by ¹ H-NMR. It can be calculated based on the concentration of silyl groups and the number average molecular weight of the organic polymer (A) determined by the GPC method.

As the polyalkylene oxide constituting the polyalkylene oxide having a hydrolyzable silyl group (A1), the main chain has the general formula: —(R ¹ —O) _n — (wherein R ¹ has a carbon number of is an alkylene group of 1 to 14, and n is the number of repeating units and is a positive integer.). 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. In addition, in the present invention, the main chain means the longest chain in the molecule. The length of the chain is determined by the number of atoms forming the chain, and the greater the number of atoms, the longer the chain.

An alkylene group is a divalent atomic group generated by excluding two hydrogen atoms bonded to two different carbon atoms in an aliphatic saturated hydrocarbon, and includes both linear and branched atomic groups. include. The term "branched" includes the case where one carbon (methyl group) is bonded as a side chain.

Examples of the alkylene group include an ethylene group, a propylene group [ _--CH.sub.2 -- _{CH.sub.2 --} CH.sub.2--(trimethylene group), --CH( _CH.sub.3 )-- _CH.sub.2-- ], a butylene group, an amylene group, and a hexylene group. mentioned.

Examples of the main chain skeleton of polyalkylene oxide include polyethylene oxide, polypropylene oxide, polybutylene oxide, polytetramethylene oxide, polyethylene oxide-polypropylene oxide copolymer, and polypropylene oxide-polybutylene oxide copolymer. Among them, polypropylene oxide is preferable. By using polypropylene oxide, the durability of the cured product of the curable composition is improved, so that the cured product can maintain excellent heat resistant rubber elasticity for a longer period of time.

The number average molecular weight (Mn) of the organic polymer (A) having a hydrolyzable silyl group is preferably 15,000 or more, more preferably 20,000 or more. On the other hand, the number average molecular weight (Mn) of the organic polymer (A) having a hydrolyzable silyl group is preferably 50,000 or less, more preferably 40,000 or less. When the number average molecular weight of the organic polymer (A) having a hydrolyzable silyl group is 15000 or more, the durability and antifouling properties of the cured product of the curable composition are improved. When the number average molecular weight of the organic polymer (A) having a hydrolyzable silyl group is 50,000 or less, the surface tack of the cured product of the curable composition is reduced, the antifouling property is improved, and the curable composition is improved. improves the coatability of

The molecular weight distribution [weight average molecular weight (Mw)/number average molecular weight (Mn)] of the organic polymer (A) having a hydrolyzable silyl group is preferably 1.4 or less, more preferably 1.3 or less. 25 or less is particularly preferred. On the other hand, the molecular weight distribution [weight average molecular weight (Mw)/number average molecular weight (Mn)] of the organic polymer (A) having a hydrolyzable silyl group is preferably 1.05 or more, more preferably 1.1 or more. When the molecular weight distribution of the organic polymer (A) having a hydrolyzable silyl group is 1.4 or less, the durability and antifouling properties of the cured product of the curable composition are improved. When the molecular weight distribution of the organic polymer (A) having a hydrolyzable silyl group is 1.05 or more, the heat-resistant rubber elasticity of the cured product of the curable composition is improved, and the adhesiveness of the cured product to the adherend is improved. It can be maintained even in a high-temperature atmosphere, and the durability of the portion to which the curable composition is applied is improved.

The number average molecular weight (Mn) of the polyalkylene oxide (A1) having a hydrolyzable silyl group is preferably 15,000 or more, more preferably 20,000 or more. On the other hand, the polyalkylene oxide (A1) having a hydrolyzable silyl group preferably has a number average molecular weight (Mn) of 50,000 or less, more preferably 40,000 or less. When the polyalkylene oxide (A1) having a hydrolyzable silyl group has a number average molecular weight of 15,000 or more, the cured product of the curable composition has improved durability and antifouling properties. When the number average molecular weight of the polyalkylene oxide having a hydrolyzable silyl group (A1) is 50000 or less, the surface tack of the cured product of the curable composition is reduced, the antifouling property is improved, and the curable composition is improved. improves the coatability of

The molecular weight distribution [weight average molecular weight (Mw)/number average molecular weight (Mn)] of the polyalkylene oxide (A1) having a hydrolyzable silyl group is preferably 1.4 or less, more preferably 1.3 or less. 25 or less is particularly preferred. On the other hand, the molecular weight distribution [weight average molecular weight (Mw)/number average molecular weight (Mn)] of the polyalkylene oxide (A1) having a hydrolyzable silyl group is preferably 1.05 or more, more preferably 1.1 or more. When the polyalkylene oxide (A1) having a hydrolyzable silyl group has a molecular weight distribution of 1.4 or less, the cured product of the curable composition has improved durability and antifouling properties. When the molecular weight distribution of the polyalkylene oxide (A1) having a hydrolyzable silyl group is 1.05 or more, the heat-resistant rubber elasticity of the cured product of the curable composition is improved, and the adhesion of the cured product to the adherend is improved. It can be maintained even in a high-temperature atmosphere, and the durability of the portion to which the curable composition is applied is improved.

In the present invention, the number-average molecular weight and weight-average molecular weight of the organic polymer mean values measured by GPC (gel permeation chromatography) and converted to polystyrene.

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

The number-average molecular weight and weight-average molecular weight of the organic polymer can be measured, for example, using the following measurement apparatus and measurement 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, polyalkylene oxide having a main chain skeleton of polypropylene oxide and having a methyldimethoxysilyl group at the end of the main chain skeleton includes AGC's product name "Exester S4530".

The content of the polyalkylene oxide (A1) having a hydrolyzable silyl group in the organic polymer (A) having a hydrolyzable silyl group is preferably 40% by mass or more, more preferably 45% by mass or more. The content of the polyalkylene oxide (A1) having a hydrolyzable silyl group in the organic polymer (A) having a hydrolyzable silyl group is preferably 80% by mass or less, more preferably 70% by mass or less, and 60% by mass. % or less is more preferable. When the content of the polyalkylene oxide (A1) having a hydrolyzable silyl group is 40% by mass or more, the heat resistant rubber elasticity of the cured product of the curable composition is improved. When the content of the polyalkylene oxide (A1) having a hydrolyzable silyl group is 80% by mass or less, the heat resistant rubber elasticity of the cured product of the curable composition is improved.

The acrylic polymer (A2) having a hydrolyzable silyl group preferably does not contain a chain containing a polyalkylene oxide chain because the cured product of the curable composition has improved heat resistant rubber elasticity. A chain containing a polyalkylene oxide has the general formula: —(R ⁶ —O)y— (wherein R ⁶ represents an alkylene group and y is the number of repeating units and is a positive integer). It is the chain containing the indicated repeat unit. A chain containing a polyalkylene oxide may consist of only one kind of repeating unit, or may consist of two or more kinds of repeating units. In addition, since the alkylene group is the same as the alkylene group described above, the description thereof is omitted.

The acrylic polymer (A2) having a hydrolyzable silyl group has a main chain skeleton composed of a polymer of acrylic monomers.

As the hydrolyzable silyl group, an alkoxysilyl group is preferable because the cured product of the curable composition can maintain excellent heat-resistant rubber elasticity over a long period of time. Alkoxysilyl groups include trialkoxysilyl groups such as trimethoxysilyl group, triethoxysilyl group, triisopropoxysilyl group, and triphenoxysilyl group; dimethoxysilyl groups such as methyldimethoxysilyl group and methyldiethoxysilyl group; and monoalkoxysilyl groups such as a dimethylmethoxysilyl group and a dimethylethoxysilyl group. Among them, a dialkoxysilyl group and a trialkoxysilyl group are more preferable, and a dialkoxysilyl group is more preferable.

The acrylic polymer (A2) having a hydrolyzable silyl group preferably has an average of 1 to 3 hydrolyzable silyl groups per molecule. When the number of hydrolyzable silyl groups in the acrylic polymer (A2) having a hydrolyzable silyl group is 1 or more, the curability of the curable composition is improved. When the number of hydrolyzable silyl groups in the acrylic polymer (A2) having a hydrolyzable silyl group is 3 or less, the heat resistant rubber elasticity of the cured product of the curable composition is improved.

The average number of hydrolyzable silyl groups per molecule in the acrylic polymer (A2) having a hydrolyzable silyl group is the same as the measurement method described above, so the description is omitted.

The main chain skeleton of the acrylic polymer (A2) having a hydrolyzable silyl group is composed of a polymer of acrylic monomers. Although the acrylic monomer is not particularly limited, it preferably contains a (meth)acrylic acid alkyl ester. When the acrylic monomer contains a (meth)acrylic acid ester, the heat resistant rubber elasticity of the cured product of the curable composition is improved. The (meth)acrylic acid alkyl ester preferably does not contain a chain containing polyalkylene oxide.

In the acrylic monomer, the content of the (meth)acrylic acid alkyl ester is preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, and more preferably 95% by mass or more. , more preferably 99% by mass or more, more preferably 100% by mass.

Examples of (meth)acrylic acid alkyl esters include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, and n-butyl (meth)acrylate. , isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate , n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, and stearyl (meth)acrylate. be done. Among them, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and stearyl (meth)acrylate are preferred. The (meth)acrylic acid alkyl esters may be used alone or in combination of two or more.

The number of carbon atoms in the alkyl group of the (meth)acrylic acid alkyl ester is preferably 2 or more, more preferably 3 or more, and more preferably 4 or more. The number of carbon atoms in the alkyl group of the (meth)acrylic acid alkyl ester is preferably 25 or less, more preferably 22 or less, and more preferably 20 or less. When the number of carbon atoms in the alkyl group of the (meth)acrylic acid alkyl ester is 2 or more, the heat resistant rubber elasticity of the cured product of the curable composition is improved. When the number of carbon atoms in the alkyl group of the (meth)acrylic acid alkyl ester is 25 or less, the viscosity of the curable composition is suppressed to improve the coatability, and the adhesiveness of the curable composition is improved.

The method for introducing a hydrolyzable silyl group into an acrylic polymer is not particularly limited. (2) a method of reacting an acrylic polymer having an unsaturated group introduced into the molecule with a compound having a mercapto group and a hydrolyzable silyl group; A method of reacting an acrylic polymer having a group with a compound having a functional group and a hydrolyzable silyl group that exhibits reactivity with this functional group, (4) (meth)acrylic having a hydrolyzable silyl group Examples thereof include a method of polymerizing an acrylic monomer containing an acid ester.

The (meth)acrylic acid ester having a hydrolyzable silyl group is not particularly limited, and examples thereof include 3-(trimethoxysilyl)propyl (meth)acrylate and 3-(triethoxysilyl)propyl (meth)acrylate. , 3-(methyldimethoxysilyl)propyl (meth)acrylate, 2-(trimethoxysilyl)ethyl (meth)acrylate, 2-(triethoxysilyl)ethyl (meth)acrylate, 2-(meth)acrylate (Methyldimethoxysilyl)ethyl, (meth)trimethoxysilylmethyl acrylate, (meth)triethoxysilylmethyl acrylate, (methyldimethoxysilyl)methyl (meth)acrylate, 4-(trimethoxysilyl(meth)acrylate) ) Butyl, 4-(triethoxysilyl)butyl (meth)acrylate, 4-(methyldimethoxysilyl)butyl (meth)acrylate, 8-(trimethoxysilyl)octyl (meth)acrylate, (meth)acrylic acid 8-(methyldimethoxysilyl)octyl and the like, preferably 3-(methyldimethoxysilyl)propyl (meth)acrylate, more preferably 3-(methyldimethoxysilyl)propyl methacrylate. Incidentally, the (meth)acrylic acid esters containing a hydrolyzable silyl group may be used alone or in combination of two or more.

The number average molecular weight of the acrylic polymer (A2) having a hydrolyzable silyl group is preferably over 10,000, more preferably 12,000 or more, more preferably 14,000 or more, and more preferably 15,000 or more. The number average molecular weight of the acrylic polymer (A2) having a hydrolyzable silyl group is preferably 40,000 or less, more preferably 35,000 or less, more preferably 30,000 or less, and more preferably 25,000 or less. When the number average molecular weight of the acrylic polymer (A2) having a hydrolyzable silyl group exceeds 10,000, the durability and antifouling properties of the cured product of the curable composition are improved. When the number average molecular weight of the acrylic polymer (A2) having a hydrolyzable silyl group is 40,000 or less, the surface tack of the cured product of the curable composition is reduced, the antifouling property is improved, and the curable composition is The coatability of the product is improved.

The molecular weight distribution [weight average molecular weight (Mw)/number average molecular weight (Mn)] of the acrylic polymer (A2) having a hydrolyzable silyl group is preferably 3.0 or less, more preferably 2.8 or less. 0.5 or less is more preferable, and 2.2 or less is more preferable. On the other hand, the molecular weight distribution [weight average molecular weight (Mw)/number average molecular weight (Mn)] of the acrylic polymer (A2) having a hydrolyzable silyl group is preferably 1.05 or more, more preferably 1.1 or more. . When the molecular weight distribution of the acrylic polymer (A2) having a hydrolyzable silyl group is 3.0 or less, the durability and antifouling properties of the cured product of the curable composition are improved. When the molecular weight distribution of the acrylic polymer (A2) having a hydrolyzable silyl group is 1.05 or more, the heat-resistant rubber elasticity of the cured product of the curable composition is improved, and the adhesion of the cured product to the adherend. can be maintained even in a high-temperature atmosphere, and the durability of the portion to which the curable composition is applied is improved.

The content of the acrylic polymer (A2) having a hydrolyzable silyl group in the organic polymer (A) having a hydrolyzable silyl group is preferably 40% by mass or more, more preferably 45% by mass or more. The content of the acrylic polymer (A2) having a hydrolyzable silyl group in the organic polymer (A) having a hydrolyzable silyl group is preferably 80% by mass or less, more preferably 70% by mass or less, and 60% by mass or less. % by mass or less is more preferable. When the content of the acrylic polymer (A2) having a hydrolyzable silyl group is 40% by mass or more, the heat resistant rubber elasticity of the cured product of the curable composition is improved. When the content of the acrylic polymer (A2) having a hydrolyzable silyl group is 80% by mass or less, the elongation at maximum load of the cured product of the curable composition is improved.

[Mineral (B)]
The curable composition contains a mineral (B) containing aluminum silicate. As the mineral (B) containing aluminum silicate, an aluminosilicate is preferred. Aluminosilicates include mullite, kaolinite, illite, feldspars, and zeolites. Note that the mineral (B) containing aluminum silicate is sometimes simply referred to as "mineral (B)".

The content of the aluminosilicate in the mineral (B) is preferably 50% by mass or more, more preferably 70% by mass or more, more preferably 90% by mass or more, more preferably 95% by mass or more, and 99% by mass or more. More preferably, 100% by mass is more preferable.

Feldspars include feldspar and quasi-feldspar, preferably quasi-feldspar. The feldspars may be used singly or in combination of two or more.

Examples of feldspar include alkali feldspar such as orthoclase, sanidine, microcline feldspar and anosclase; be done.

Examples of quasi-feldspar include nepheline such as calcilite and cancrinite, nepheline syenite, leucite, and soda. Examples include sodalite, auin, lazurite, nosean, and melilite, with nepheline syenite being preferred. Nepheline syenite is sometimes described as syenite.

The feldspars have an average particle size of 0.01 to 100 μm, preferably 0.1 to 50 μm, more preferably 1 to 25 μm, more preferably 2 to 15 μm, and more preferably 3 to 10 μm. When the average particle size of the feldspars is 0.01 μm or more, the dispersibility of the feldspars in the cured product of the curable composition is improved, the heat resistant rubber elasticity of the cured product of the curable composition is improved, and the cured product is cured. The adhesiveness of the article to the adherend can be maintained even in a high-temperature atmosphere, and the durability of the applied portion of the curable composition is improved. When the average particle size of the feldspars is 100 µm or less, the heat resistant rubber elasticity of the cured product of the curable composition is improved.

The mean particle size of feldspars refers to a value measured by image analysis using a transmission electron microscope. Specifically, feldspars were photographed at a magnification of 100 times using a transmission electron microscope, 50 arbitrary feldspars were extracted, the diameter of each feldspar was measured, and the diameter of each feldspar was measured. The arithmetic mean value of is taken as the average particle size of the feldspars. The diameter of the feldspars refers to the diameter of the smallest perfect circle that can surround the feldspars.

In the curable composition, the content of the mineral (B) containing aluminum silicate is preferably 5 parts by mass or more, preferably 10 parts by mass or more, relative to 100 parts by mass of the organic polymer (A) having a hydrolyzable silyl group. is more preferable, 15 parts by mass or more is more preferable, and 18 parts by mass or more is more preferable. The content of the mineral (B) containing aluminum silicate is preferably 200 parts by mass or less, more preferably 150 parts by mass or less, more preferably 100 parts by mass with respect to 100 parts by mass of the organic polymer (A) having a hydrolyzable silyl group. Parts or less is more preferable, 80 parts by mass or less is more preferable, 60 parts by mass or less is more preferable, and 50 parts by mass or less is more preferable. When the content of the mineral (B) is within the above range, the heat resistant rubber elasticity and antifouling properties of the cured product of the curable composition are improved.

[(Meth) acrylic acid ester polymer (C)]
The curable composition contains a (meth)acrylate polymer (C) containing a (meth)acrylate unit having a polyethylene oxide chain. The (meth)acrylic ester polymer (C) containing (meth)acrylic ester units having a polyethylene oxide chain is sometimes simply referred to as "(meth)acrylic ester polymer (C)". In the present invention, (meth)acrylic acid means acrylic acid or methacrylic acid.

The curable composition contains a (meth)acrylic acid ester polymer (C) containing a (meth)acrylic acid ester unit having a polyethylene oxide chain. improve sexuality.

Furthermore, by containing the (meth)acrylic acid ester polymer (C) containing (meth)acrylic acid ester units having a polyethylene oxide chain, the surface of the cured product of the curable composition is rendered moderately hydrophilic. can be As a result, when water comes into contact with the surface of the cured product of the curable composition due to rainfall or the like, the water spreads thinly on the surface of the cured product without becoming water droplets and can easily run off. Therefore, the occurrence of rain streak stains on the surface of the cured product of the curable composition can be reduced, and the cured product of the curable composition has excellent antifouling properties.

Further, by containing a (meth)acrylic acid ester polymer (C) containing a (meth)acrylic acid ester unit having a polyethylene oxide chain, an organic polymer (A) having a hydrolyzable silyl group and a mineral Mixability with (B) is improved, the heat resistant rubber elasticity of the cured product of the curable composition is improved, and the curability of the curable composition is also improved.

Thus, the curable composition contains an organic polymer (A) having a hydrolyzable silyl group, a mineral (B) containing aluminum silicate and a (meth)acrylate unit having a polyethylene oxide chain ( By containing the meth)acrylic acid ester polymer (C), the cured product of the curable composition has excellent antifouling properties and heat resistant rubber elasticity.

The (meth)acrylic acid ester polymer (C) contains (meth)acrylic acid ester units containing polyethylene oxide chains. The (meth)acrylic acid ester polymer (C) has polyethylene oxide chains in side chains.

The main chain skeleton of the (meth)acrylic acid ester polymer (C) is preferably a polymer of acrylic monomers containing a (meth)acrylic acid ester containing a polyethylene oxide chain. An acrylic monomer has an ethylenically unsaturated double bond, and a polymer of the acrylic monomer is obtained by addition-polymerizing the acrylic monomer at the ethylenically unsaturated double bond. .

A (meth)acrylic acid ester containing a polyethylene oxide chain is preferably a (meth)acrylic acid ester represented by the following general formula (1).
_CH2 =C( ^R2 )C(O)-( _OCH2CH2 ) _m - ^OR3 (1 ₎
(In the formula, R ² is a hydrogen atom or a methyl group, R ³ is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 24 carbon atoms, a substituted or unsubstituted or a substituted or unsubstituted aralkyl group having 7 to 20 carbon atoms, and m is an integer of 2 to 100.)

R ² in formula (1) is preferably a methyl group.

m in formula (1) is the number of repeating units, preferably an integer of 2 or more, more preferably an integer of 3 or more, and particularly preferably an integer of 4 or more. On the other hand, m in formula (1) is preferably an integer of 100 or less, more preferably an integer of 40 or less, and more preferably an integer of 30 or less.

The substituted or unsubstituted alkyl group having 1 to 24 carbon atoms in R ³ of formula (1) may be either linear or branched, and is not particularly limited. Examples of unsubstituted alkyl groups include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, amyl group and isoamyl group. , tert-amyl group, neopentyl group, n-hexyl group and the like. Hydrogen atoms of these alkyl groups may be substituted with organic groups such as hydroxy groups and alkoxy groups. Note that the aryl group is preferably excluded from the above organic groups. Examples of substituted alkyl groups include hydroxyalkyl groups and alkoxyalkyl groups. The substituted alkyl group preferably excludes an alkyl group in which a hydrogen atom is substituted with a substituent containing an aromatic ring, such as a benzyl group.

In the substituted or unsubstituted aryl group having 6 to 20 carbon atoms in R ³ of formula (1), the aromatic ring constituting the aryl group may be a single ring or a condensed ring. Examples of unsubstituted aryl groups include phenyl, 1-naphthyl, 2-naphthyl, 1-anthracenyl, 2-anthracenyl and 9-anthracenyl groups. A hydrogen atom possessed by these aryl groups may be substituted with an organic group such as a hydroxy group, an alkyl group, or an alkoxy group. Examples of substituted aryl groups include alkoxyphenyl groups and alkylphenyl groups.

Examples of substituted or unsubstituted aralkyl groups having 7 to 20 carbon atoms in R ³ of formula (1) include benzyl group, α,α-phenylmethylbenzyl group, α,α-dimethylbenzyl group, α,α- methylphenylbenzyl group, α-naphthylmethyl group, 1-α-naphthylethyl group, 2-α-naphthylethyl group, 1-α-naphthylisopropyl group, 2-α-naphthylisopropyl group, β-naphthylmethyl group, 1 -β-naphthylethyl group, 2-β-naphthylethyl group, 1-β-naphthylisopropyl group, and 2-β-naphthylisopropyl group.

R ³ in formula (1) is preferably a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 24 carbon atoms, more preferably an unsubstituted alkyl group having 1 to 10 carbon atoms. More preferred are unsubstituted alkyl groups whose number is 1-3.

An alcohol residue forming a (meth)acrylic acid ester containing a polyethylene oxide chain is preferably a polyethylene glycol residue capped with an alkyl group having 1 to 24 carbon atoms.

Specific examples of the (meth)acrylic acid ester containing a polyethylene oxide chain include methoxypolyethylene glycol (meth)acrylate, ethoxypolyethyleneglycol (meth)acrylate, and propoxypolyethyleneglycol (meth)acrylate. Methoxypolyethylene glycol (meth)acrylate is preferred, and methoxypolyethylene glycol methacrylate is more preferred. The (meth)acrylic acid esters containing polyethylene oxide chains may be used alone or in combination of two or more.

In the (meth)acrylate polymer (C), the content of (meth)acrylate units containing a polyethylene oxide chain is preferably 5% by mass or more, preferably 10% by mass or more, and 20% by mass or more. is more preferably 25% by mass or more, more preferably 40% by mass or more, more preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more It is preferably 90% by mass or more, more preferably 95% by mass or more, more preferably 99% by mass or more, and more preferably 100% by mass. When the content of the (meth)acrylic acid ester unit containing a polyethylene oxide chain is 5% by mass or more, the surface of the cured product of the curable composition can be made moderately hydrophilic, thereby making the cured product Both antifouling property and heat resistant rubber elasticity can be improved. If the hydrophilicity of the surface of the cured product of the curable composition is too high, the cured product will contact moisture in the air or water such as rainwater, thereby accelerating the deterioration of the heat resistant rubber elasticity of the cured product of the curable composition. may cause

The (meth)acrylic acid ester-based polymer (C) preferably contains (meth)acrylic acid alkyl ester units. A polymer of acrylic monomers in which the main chain skeleton of the (meth)acrylic acid ester polymer (C) contains a (meth)acrylic acid ester containing a polyethylene oxide chain and a (meth)acrylic acid alkyl ester is more preferable. By using the (meth)acrylic acid alkyl ester, the heat resistant rubber elasticity of the cured product of the curable composition is improved. In addition, the (meth)acrylic acid alkyl ester preferably does not contain a polyethylene oxide chain and/or a hydrolyzable silyl group. It is preferable that the hydrogen atoms in the alkyl group of the (meth)acrylic acid alkyl ester are not substituted.

Examples of (meth)acrylic acid alkyl esters include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, and n-butyl (meth)acrylate. , isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate , n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, and stearyl (meth)acrylate. be done. Among them, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, and (meth)acrylic acid n-hexyl is preferred, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate and n-butyl (meth)acrylate are more preferred, n-butyl (meth)acrylate is more preferred. The (meth)acrylic acid alkyl esters may be used alone or in combination of two or more.

The (meth)acrylate polymer (C) may have a hydrolyzable silyl group. The hydrolyzable silyl group is the same as the hydrolyzable silyl group described for the organic polymer (A), so the description is omitted. The hydrolyzable silyl group of the (meth)acrylate polymer (C) and the hydrolyzable silyl group of the organic polymer (A) may be the same or different. As the hydrolyzable silyl group of the (meth)acrylic acid ester-based polymer (C), an alkoxysilyl group is used because the cured product of the curable composition can maintain excellent heat-resistant rubber elasticity over a long period of time. is preferred. Alkoxysilyl groups include trialkoxysilyl groups such as trimethoxysilyl group, triethoxysilyl group, triisopropoxysilyl group, and triphenoxysilyl group; dimethoxysilyl groups such as methyldimethoxysilyl group and methyldiethoxysilyl group; and monoalkoxysilyl groups such as a dimethylmethoxysilyl group and a dimethylethoxysilyl group. Among them, a dialkoxysilyl group and a trialkoxysilyl group are more preferable, a trialkoxysilyl group is more preferable, and a trimethoxysilyl group is more preferable.

The (meth)acrylate polymer (C) preferably has an average of 0.1 to 3 hydrolyzable silyl groups per molecule. When the number of hydrolyzable silyl groups in the (meth)acrylate polymer (C) is 0.1 or more, the curability of the curable composition is improved. When the number of hydrolyzable silyl groups in the (meth)acrylic acid ester polymer (C) is 3 or less, the cured product of the curable composition has improved mechanical strength or heat resistant rubber elasticity.

The average number of hydrolyzable silyl groups per molecule in the (meth)acrylate polymer (C) is determined by ¹ H-NMR. It can be calculated based on the concentration of hydrolyzable silyl groups in the medium and the number average molecular weight of the (meth)acrylate polymer (C) determined by the GPC method.

The (meth)acrylate polymer (C) preferably contains a (meth)acrylate unit containing a hydrolyzable silyl group. The main chain skeleton of the (meth)acrylate polymer (C) comprises a (meth)acrylate unit containing a polyethylene oxide chain and a (meth)acrylate unit containing a hydrolyzable silyl group. More preferably, it is a polymer of an acrylic monomer containing a (meth) acrylic acid ester unit containing a polyethylene oxide chain, a (meth) acrylic acid alkyl ester unit, and a hydrolyzable silyl group ( It is more preferably a polymer of acrylic monomers containing meth)acrylic acid ester units.

The (meth)acrylic acid ester containing a hydrolyzable silyl group is not particularly limited, and examples thereof include 3-(trimethoxysilyl)propyl (meth)acrylate and 3-(triethoxysilyl)(meth)acrylate. Propyl, 3-(methyldimethoxysilyl)propyl (meth)acrylate, 2-(trimethoxysilyl)ethyl (meth)acrylate, 2-(triethoxysilyl)ethyl (meth)acrylate, 2-(meth)acrylate -(methyldimethoxysilyl)ethyl, trimethoxysilylmethyl (meth)acrylate, triethoxysilylmethyl (meth)acrylate, (methyldimethoxysilyl)methyl (meth)acrylate and the like. Among them, 3-(trimethoxysilyl)propyl (meth)acrylate and 3-(methyldimethoxy)propyl (meth)acrylate are preferred, 3-(trimethoxysilyl)propyl (meth)acrylate is more preferred, and methacryl More preferred is the 3-(trimethoxysilyl)propyl acid. The (meth)acrylic acid esters containing a hydrolyzable silyl group may be used alone or in combination of two or more.

The (meth)acrylate polymer (C) may contain (meth)acrylic acid-substituted alkyl ester units. (Meth)acrylic acid-substituted alkyl ester means that the hydrogen atom possessed by the alkyl group of the (meth)acrylic acid alkyl ester is an alkoxy group, a hydroxy group, a halogen atom (fluorine atom, chlorine atom, etc.), a fluoroalkyl group , means a compound substituted by an organic group such as an amino group.

Examples of (meth)acrylic acid-substituted alkyl esters include 2-methoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and 2-hydroxyethyl (meth)acrylate. Hydroxypropyl, 2,2,2-trifluoroethyl (meth)acrylate, 3,3,3-trifluoropropyl (meth)acrylate, 3,3,4,4,4-pentafluoro (meth)acrylate Butyl, 2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate, trifluoromethyl (meth)acrylate, perfluoroethyl (meth)acrylate, bis(trifluoromethyl)methyl (meth)acrylate , 2-trifluoromethyl-2-perfluoroethylethyl (meth)acrylate, 2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl (meth)acrylate, 2-(meth)acrylate perfluorohexadecylethyl, dimethylaminoethyl (meth)acrylate, 2-chloroethyl (meth)acrylate, 2-aminoethyl (meth)acrylate and the like. The (meth)acrylic acid-substituted alkyl esters may be used alone or in combination of two or more.

(Meth)acrylate polymer (C) includes (meth)acrylic acid, phenyl (meth)acrylate, toluyl (meth)acrylate, benzyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and the like. may contain other acrylic monomer units.

The method for synthesizing the (meth)acrylic acid ester polymer (C) is not particularly limited and includes known methods. Examples thereof include various polymerization methods such as free radical polymerization, anionic polymerization, cationic polymerization, UV radical polymerization, living anionic polymerization, living cationic polymerization, and living radical polymerization.

For example, as a free radical polymerization method, a (meth)acrylic acid ester containing a polyethylene oxide chain and, if necessary, a (meth)acrylic acid alkyl ester or a (meth)acrylic acid ester containing a hydrolyzable silyl group A solution polymerization method for polymerizing the acrylic monomer at 50 to 150 ° C. by adding a polymerization initiator, a chain transfer agent, a solvent, etc. to the acrylic monomer containing Examples thereof include a continuous bulk polymerization method in which polymerization is performed at high temperature and high pressure as described in JP-A No. 2001-207157.

As the polymerization initiator, usually an oil-soluble radical initiator is used to initiate the reaction. Oil-soluble radical initiators include, for example, azo polymerization initiators and organic peroxides.

The azo polymerization initiator is not particularly limited. Azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis[N-(2-propenyl)-2-methylpropion amide], 1,1′-azobis(cyclohexane-1-carbonitrile) and the like.

The organic peroxide is not particularly limited, and examples thereof include benzoyl peroxide, isobutyryl peroxide, isononanoyl peroxide, decanoyl peroxide, lauroyl peroxide, parachlorobenzoyl peroxide, di(3,5,5 -trimethylhexanoyl) peroxide; - Peroxydicarbonates such as 3-methoxybutyl peroxydicarbonate and dicyclohexyl peroxydicarbonate; tert-butyl peroxybenzoate, tert-butyl peroxyacetate, tert-butyl peroxy-2-ethylhexanoate, tert- peroxyesters such as butyl peroxyisobutyrate, tert-butyl peroxypivalate, tert-butyl diperoxyadipate, cumyl peroxyneodecanoate; ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide; - dialkyl peroxides such as tert-butyl peroxide, dicumyl peroxide, tert-butyl cumyl peroxide, 1,1-di(tert-hexylperoxy)-3,3,5-trimethylcyclohexane; cumene hydroperoxide , tert-butyl hydroperoxide; 1,1-di(tert-hexylperoxy)-3,3,5-trimethylcyclohexane; When a peroxide is used as the radical polymerization initiator, it may be used in combination with a reducing agent as a redox polymerization initiator. The polymerization initiators may be used alone or in combination of two or more.

Examples of chain transfer agents include mercapto group-containing compounds such as n-dodecylmercaptan, tert-dodecylmercaptan, and laurylmercaptan. Further, when it is desired to introduce a hydrolyzable silyl group to the molecular chain end of the (meth)acrylic acid ester polymer (C), examples of chain transfer agents include 3-mercaptopropyltrimethoxysilane, 3-mercapto propylmethyldimethoxysilane, 3-mercaptopropylchloromethyldimethoxysilane, 3-mercaptopropylmethoxymethyldimethoxysilane, mercaptomethyltrimethoxysilane, (mercaptomethyl)dimethoxymethylsilane and the like. Chain transfer agents may be used alone or in combination of two or more. Since chain transfer agents may adversely affect durability, the amount used is preferably 2% or less of the total amount of monomers, and it is particularly preferable not to use them.

Examples of solvents include aromatic compounds such as toluene, xylene, styrene, ethylbenzene, paradichlorobenzene, di-2-ethylhexyl phthalate, and di-n-butyl phthalate; hexane, heptane, octane, cyclohexane, methylcyclohexane, and the like. Carboxylic acid ester compounds such as butyl acetate, n-propyl acetate and isopropyl acetate; Ketone compounds such as methyl isobutyl ketone and methyl ethyl ketone; Dialkyl carbonate compounds such as dimethyl carbonate and diethyl carbonate; 1-propanol and 2-propanol , 1-butanol, 2-butanol, isobutanol, tert-butyl alcohol, amyl alcohol, and other alcohol compounds. Among them, dimethyl carbonate, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol and tert-butyl alcohol are more preferable, and 2-propanol and isobutanol are particularly preferable.

The number average molecular weight (Mn) of the (meth)acrylate polymer (C) is preferably 1,000 or more, more preferably 1,500 or more. The number average molecular weight (Mn) of the (meth)acrylate polymer (C) is preferably 20,000 or less, more preferably 10,000 or less, more preferably 8,000 or less, more preferably 6,000 or less, and more preferably 4,000 or less. 3000 or less is more preferable. When the number average molecular weight of the (meth)acrylic acid ester polymer (C) is 1000 or more, the heat resistant rubber elasticity of the cured product of the curable composition is improved. When the number average molecular weight of the (meth)acrylic acid ester polymer (C) is 20000 or less, the coatability of the curable composition is improved.

The content of the (meth)acrylic acid ester polymer (C) in the curable composition is preferably 5 parts by mass or more relative to 100 parts by mass of the organic polymer (A) having a hydrolyzable silyl group. It is more preferably at least 15 parts by mass, more preferably at least 15 parts by mass. The content of the (meth)acrylic acid ester polymer (C) in the curable composition is preferably 200 parts by mass or less with respect to 100 parts by mass of the organic polymer (A) having a hydrolyzable silyl group. It is more preferably not more than 75 parts by mass, more preferably not more than 75 parts by mass. When the content of the (meth)acrylate polymer (C) is 5 parts by mass or more, the cured product of the curable composition has improved antifouling properties and heat resistant rubber elasticity. When the content of the (meth)acrylic acid ester polymer (C) is 200 parts by mass or less, the heat-resistant rubber elasticity of the cured product of the curable composition is improved, and the adhesion of the cured product to the adherend at high temperatures. It can be maintained even in an atmosphere, and the durability of the portion to which the curable composition is applied is improved, and the coatability of the curable composition is improved.

[Plasticizer]
The curable composition preferably 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 number average molecular weight of 400 to 9,000 are preferably 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 used as a plasticizer is preferably a (meth)acrylic polymer (D) containing a hydrolyzable silyl group. The (meth)acrylic polymer (D) does not have a chain containing polyalkylene oxide. Incidentally, the (meth)acrylic polymer (D) containing a hydrolyzable silyl group may be simply referred to as "(meth)acrylic polymer (D)".

A chain containing a polyalkylene oxide has the general formula: —(R ⁵ —O) _x — (wherein R ⁵ represents an alkylene group, and x is the number of repeating units and is a positive integer). It is the chain containing the indicated repeat unit. A chain containing a polyalkylene oxide may consist of only one kind of repeating unit, or may consist of two or more kinds of repeating units. The alkylene group is the same as the alkylene group described for the organic polymer (A), so the description is omitted.

The (meth)acrylic polymer (D) has a main chain skeleton composed of a polymer of acrylic monomers. The acrylic monomer unit constituting the main chain skeleton of the (meth)acrylic polymer (D) contains a (meth)acrylic acid ester unit containing a hydrolyzable silyl group. (Meth)acrylic acid esters containing hydrolyzable silyl groups do not have chains containing polyalkylene oxides.

As the hydrolyzable silyl group, an alkoxysilyl group is preferable because the cured product of the curable composition can maintain excellent heat-resistant rubber elasticity over a long period of time. Alkoxysilyl groups include trialkoxysilyl groups such as trimethoxysilyl group, triethoxysilyl group, triisopropoxysilyl group, and triphenoxysilyl group; dimethoxysilyl groups such as methyldimethoxysilyl group and methyldiethoxysilyl group; and monoalkoxysilyl groups such as a dimethylmethoxysilyl group and a dimethylethoxysilyl group. Among them, a dialkoxysilyl group and a trialkoxysilyl group are more preferable, a trialkoxysilyl group is more preferable, and a trimethoxysilyl group is more preferable.

The (meth)acrylic polymer (D) preferably has an average of 1 to 3 hydrolyzable silyl groups per molecule. When the number of hydrolyzable silyl groups in the (meth)acrylic polymer (D) is 1 or more, the curability of the curable composition is improved. When the number of hydrolyzable silyl groups in the (meth)(meth)acrylic polymer (D) is 3 or less, the heat resistant rubber elasticity of the cured product of the curable composition is improved.

The average number of hydrolyzable silyl groups per molecule in the (meth)acrylic polymer (D) is the same as the method for measuring the organic polymer (A), so the description is omitted.

The (meth)acrylic acid ester containing a hydrolyzable silyl group is not particularly limited, and examples thereof include 3-(trimethoxysilyl)propyl (meth)acrylate and 3-(triethoxysilyl)(meth)acrylate. Propyl, 3-(methyldimethoxysilyl)propyl (meth)acrylate, 2-(trimethoxysilyl)ethyl (meth)acrylate, 2-(triethoxysilyl)ethyl (meth)acrylate, 2-(meth)acrylate -(methyldimethoxysilyl)ethyl, trimethoxysilylmethyl (meth)acrylate, triethoxysilylmethyl (meth)acrylate, (methyldimethoxysilyl)methyl (meth)acrylate and the like. Among them, 3-(trimethoxysilyl)propyl (meth)acrylate and 3-(methyldimethoxy)propyl (meth)acrylate are preferred, 3-(trimethoxysilyl)propyl (meth)acrylate is more preferred, and methacryl More preferred is the 3-(trimethoxysilyl)propyl acid. The (meth)acrylic acid esters containing a hydrolyzable silyl group may be used alone or in combination of two or more.

The main chain skeleton of the (meth)acrylic polymer (D) preferably contains (meth)acrylic acid alkyl ester units. The (meth)acrylic polymer (D) is more preferably a polymer of acrylic monomers containing a (meth)acrylic acid ester having a hydrolyzable silyl group and a (meth)acrylic acid alkyl ester. , a polymer of a (meth)acrylic acid ester having a hydrolyzable silyl group and a (meth)acrylic acid alkyl ester. By using the (meth)acrylic acid alkyl ester, the heat resistant rubber elasticity of the cured product of the curable composition is improved. The (meth)acrylic acid ester and (meth)acrylic acid alkyl ester having a hydrolyzable silyl group do not contain a chain containing polyalkylene oxide. In the (meth)acrylic polymer (D), the total content of (meth)acrylic acid ester units having a hydrolyzable silyl group and (meth)acrylic acid alkyl ester units is preferably 80% by mass or more, and 90% by mass. It is more preferably 95% by mass or more, more preferably 99% by mass or more, and more preferably 100% by mass.

Examples of (meth)acrylic acid alkyl esters include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, and n-butyl (meth)acrylate. , isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate , n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, and stearyl (meth)acrylate. be done. Among them, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-(meth)acrylate -hexyl and 2-ethylhexyl (meth)acrylate are preferred, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate and (meth)acrylic Acid 2-ethylhexyl is more preferred, methyl (meth)acrylate, 2-ethylhexyl (meth)acrylate and n-butyl (meth)acrylate are more preferred, methyl (meth)acrylate and 2-(meth)acrylate Ethylhexyl is more preferred, and methyl methacrylate and 2-ethylhexyl acrylate are more preferred. The (meth)acrylic acid alkyl ester preferably contains methyl (meth)acrylate and 2-ethylhexyl (meth)acrylate. The (meth)acrylic acid alkyl esters may be used alone or in combination of two or more.

The number average molecular weight (Mn) of the (meth)acrylic polymer (D) is preferably 500 or more, more preferably 1000 or more. The number average molecular weight of the (meth)acrylic polymer (D) is preferably 10,000 or less, more preferably 5,000 or less, more preferably 4,000 or less, more preferably 3,000 or less, and more preferably 2,000 or less. When the number average molecular weight of the acrylic polymer (D) is 500 or more, the heat-resistant rubber elasticity of the cured product of the curable composition is improved, and the adhesion of the cured product to the adherend is maintained even in a high-temperature atmosphere. and the durability of the portion to which the curable composition is applied is improved. When the number average molecular weight of the (meth)acrylic polymer (D) is 10,000 or less, the heat resistant rubber elasticity of the cured product of the curable composition is improved.

The content of the (meth)acrylic polymer (D) in the plasticizer is preferably 1% by mass or more, more preferably 10% by mass or more, and more preferably 100% by mass. That is, the plasticizer preferably contains only the (meth)acrylic polymer (D). When the content of the (meth)acrylic polymer (D) is 1% by mass or more, the cured product of the curable composition has excellent heat resistant rubber elasticity.

The content of the plasticizer in the curable composition is preferably 1 part by mass or more, more preferably 10 parts by mass or more, relative to 100 parts by mass of the organic polymer (A) having a hydrolyzable silyl group. The content of the plasticizer in the curable composition is preferably 80 parts by mass or less, more preferably 60 parts by mass or less, relative to 100 parts by mass of the organic polymer (A) having a hydrolyzable silyl group.

[Silanol condensation catalyst]
The curable composition preferably contains a silanol condensation catalyst. The silanol condensation catalyst is a catalyst for promoting the dehydration condensation reaction between silanol groups formed by hydrolyzing the hydrolyzable silyl groups contained in the organic polymer (A).

The silanol condensation catalyst is not particularly limited. , dibutyltin phthalate, bis(dibutyltin laurate) oxide, dibutyltin bis(acetylacetonate), dibutyltin bis(monoester maleate), tin octoate, dibutyltin octoate, dioctyltin oxide, dibutyltin bis(tri ethoxysilicate), bis(dibutyltin bistriethoxysilicate) oxide, and organic tin compounds such as dibutyltinoxybisethoxysilicate; organic titanium compounds such as tetra-n-butoxy titanate and tetraisopropoxy titanate; . Among them, organic tin compounds are preferable, and dioctyltin oxide is more preferable. These silanol condensation catalysts may be used alone or in combination of two or more.

The content of the silanol condensation catalyst in the curable composition is preferably 0.1 parts by mass or more, more preferably 0.2 parts by mass or more, relative to 100 parts by mass of the organic polymer (A) having a hydrolyzable silyl group. Preferably, 0.3 parts by mass or more is more preferable. The content of the silanol condensation catalyst in the curable composition is preferably 10 parts by mass or less, more preferably 8 parts by mass or less with respect to 100 parts by mass of the organic polymer (A) having a hydrolyzable silyl group, and 6 parts by mass. Parts or less is more preferable, and 5 parts by mass or less is more preferable. When the content of the silanol condensation catalyst in the curable composition is 0.1 parts by mass or more, the curing speed of the curable composition is increased, and the time required for curing the curable composition is shortened. can be done. 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 handleability of the curable composition can be improved. can.

[Aminosilane compound]
The curable composition preferably contains an aminosilane compound. The aminosilane compounds may be used alone or in combination of two or more. As the aminosilane compound, aminoalkoxysilanes are 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. 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. Preferably, the aminosilane compound does not contain chains containing polyalkylene oxides. The chain containing polyalkylene oxide is the same as the chain described for the (meth)acrylic polymer (D), so the description is omitted.

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 ⁸ , -(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) At least one aminopropyl functional group selected from the group consisting of ethyl]amino]propyl groups) is 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 ⁸ , R ⁸ is an alkyl group having 1 to 18 carbon atoms, a monovalent saturated alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a 6 to 12 aryl groups.

The alkyl group having 1 to 18 carbon atoms in R ⁸ includes a linear alkyl group and a branched alkyl group. 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 for R ⁸ include cyclopentyl group, cycloheptyl group, cyclohexyl group, 4-methylcyclohexyl group, cyclooctyl group and the like. , cyclohexyl groups are preferred.

The aryl group having 6 to 12 carbon atoms in R ⁸ includes, for example, a phenyl group.

Specific examples of aminoalkoxysilanes include 3-aminopropyltrimethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, and N-2-(aminoethyl)-3-aminopropyltrimethoxysilane. Silane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, N,N'-bis-[3-(trimethoxysilyl)propyl]ethylenediamine, N,N'-bis-[3-(tri ethoxysilyl)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. Aminoalkoxysilanes may be used alone or in combination of two or more.

The aminosilane compound may be the above-described aminoalkoxysilane or a hydrolytic condensate of aminoalkoxysilane. Examples of aminosilane compounds include alkoxysilane oligomers, which are hydrolytic condensates of aminoalkoxysilanes, and alkoxysilane oligomers, which are hydrolytic condensates of aminoalkoxysilanes and alkylalkoxysilanes. That is, the aminosilane compound includes an alkoxysilane oligomer obtained by hydrolyzing an aminoalkoxysilane and then condensing it, and an alkoxysilane oligomer obtained by hydrolyzing an aminoalkoxysilane and an alkylalkoxysilane and then condensing them.

Alkylalkoxysilane means a compound in which at least one alkyl group and at least two alkoxy groups are bonded directly to a silicon atom. The alkylalkoxysilanes include monoalkyltrialkoxysilanes in which one alkyl group and three alkoxy groups are directly bonded to a silicon atom, and two alkyl groups and two alkoxy groups in which silicon is bonded. Dialkyldialkoxysilanes directly attached to atoms are included. Specific examples of monoalkyltrialkoxysilanes include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, and hexyltrimethoxysilane. Specific examples of dialkyldialkoxysilanes include dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, and diethyldiethoxysilane. Among them, monoalkyltrialkoxysilane is preferred, and ethyltriethoxysilane is more preferred. The alkylalkoxysilanes may be used alone or in combination of two or more.

The content of the aminosilane compound in the curable composition is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, relative to 100 parts by mass of the organic polymer (A) having a hydrolyzable silyl group. , more preferably 1 part by mass or more. The content of the aminosilane compound in the curable composition is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and 3 parts by mass with respect to 100 parts by mass of the organic polymer (A) having a hydrolyzable silyl group. The following are more preferred. When the content of the aminosilane compound is 0.1 parts by mass or more, the adhesiveness of the curable composition is improved. When the content of the aminosilane compound is 10 parts by mass or less, the curability of the curable composition is improved.

[filler]
The curable composition preferably contains fillers. 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 the filler is preferably 0.01-5 μm, more preferably 0.05-2.5 μm. According to the filler having such an average particle size, it is possible to obtain a cured product having excellent mechanical strength and heat-resistant rubber elasticity, and a curable composition having excellent adhesiveness. can be provided.

The average particle size of the filler is a value calculated from the arithmetic mean of the diameters of 10 particles measured on a scale by observation with SEM. The particle diameter is the diameter of the smallest perfect circle that can enclose the particle in a micrograph obtained by SEM (Scanning Electron Microscope).

Calcium carbonate is preferably surface-treated with fatty acid, 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 part by mass or more, more preferably 10 parts by mass or more, and 50 parts by mass with respect to 100 parts by mass of the organic polymer (A) having a hydrolyzable silyl group. The above is more preferable, and 100 parts by mass or more is particularly preferable. The content of the filler in the curable composition is preferably 700 parts by mass or less, more preferably 250 parts by mass or less, and 200 parts by mass with respect to 100 parts by mass of the organic polymer (A) having a hydrolyzable silyl group. The following are particularly preferred. 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 heat resistant 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 parts by mass or more, more preferably 1 part by mass or more, relative to 100 parts by mass of the organic polymer (A) having a hydrolyzable silyl group. On the other hand, the content of the dehydrating agent in the curable composition is preferably 20 parts by mass or less, more preferably 15 parts by mass or less with respect to 100 parts by mass of the organic polymer (A) having a hydrolyzable silyl group. 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 may further contain a light stabilizer. Light stabilizers include hindered amine light stabilizers. 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}], polycondensation products of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, etc. Hindered amine light stabilizers. may be used alone or in combination of two or more.

The content of the hindered amine light stabilizer in the curable composition is preferably 0.01 parts by mass or more, preferably 0.1 parts by mass or more, relative to 100 parts by mass of the organic polymer (A) having a hydrolyzable silyl group. is more preferred. The content of the hindered amine light stabilizer in the curable composition is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, relative to 100 parts by mass of the organic polymer (A) having a hydrolyzable silyl group.

[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 parts by mass or more, more preferably 1 part by mass or more, relative to 100 parts by mass of the organic polymer (A) having a hydrolyzable silyl group. . The content of the thixotropic agent in the curable composition is preferably 200 parts by mass or less, more preferably 150 parts by mass or less, relative to 100 parts by mass of the organic polymer (A) having a hydrolyzable silyl group. 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 parts by mass or more, more preferably 0.5 parts by mass or more, relative to 100 parts by mass of the organic polymer (A) having a hydrolyzable silyl group. preferable. The content of the ultraviolet absorber in the curable composition is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, relative to 100 parts by mass of the organic polymer (A) having a hydrolyzable silyl group.

Examples of antioxidants include hindered phenol antioxidants, monophenol antioxidants, bisphenol antioxidants, and polyphenol antioxidants. The content of the antioxidant in the curable composition is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, relative to 100 parts by mass of the organic polymer (A) having a hydrolyzable silyl group. preferable. The content of the antioxidant in the curable composition is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, relative to 100 parts by mass of the organic polymer (A) having a hydrolyzable silyl group.

Since the curable composition can form a cured product that can maintain excellent rubber elasticity for a long period of time, it can be used in various applications such as sealants, coating materials, adhesives, and paints. can. Among others, it is preferably used as a sealant, and more preferably used as a joint structural sealant.

Furthermore, since the cured product of the curable composition of the present invention has excellent antifouling properties, it reduces the occurrence of rain streak stains, and even when used outdoors, it can be used beautifully for a long period of time. Appearance can be preserved.

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 Examples of the wall portion of the building structure include an outer wall, an inner wall, a ceiling portion, etc. Among them, the outer wall is preferable. The wall member includes, for example, an outer wall member, an inner wall member, a ceiling member, and the like, and an outer wall member is preferable.

The joints are not particularly limited, but examples include joints in outer walls, inner walls, and ceilings of building structures. The curable composition can exhibit excellent antifouling properties after curing. Furthermore, the curable composition can maintain excellent rubber elasticity for a long period of time after curing, even at high temperatures due to temperature, sunshine, and the like. In addition, since the curable composition can maintain excellent heat-resistant rubber elasticity after curing for a long period of time, joints due to expansion and contraction of members due to temperature changes such as air temperature and sunlight, or due to the action of vibration and wind pressure. It exhibits excellent followability to changes in the width of the wall, and can prevent damage to members and water leakage into the building structure. Therefore, the curable composition is suitably used for sealing joints on the outer walls of building structures, which are so-called "working joints" where contaminants are likely to adhere and rain streaks are likely to occur.

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 described above, it is cured by the atmosphere (air) or moisture in the member to produce a cured product excellent in both antifouling property and heat-resistant rubber elasticity. can do.

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.
[Organic polymer (A) having a hydrolyzable silyl group]
[Polyalkylene oxide having a hydrolyzable silyl group (A1)]
- A polyalkylene oxide containing a methyldimethoxysilyl group and having a main chain skeleton made of polypropylene oxide [polyalkylene oxide (A11), product name "Exester S4530" manufactured by AGC Co., Ltd., number average molecular weight (Mn): 25000, molecular weight Distribution (Mw/Mn): 1.16, average number of methyldimethoxysilyl groups per molecule: 1.6]
- A polyalkylene oxide containing a methyldimethoxysilyl group and having a main chain skeleton made of polypropylene oxide [polyalkylene oxide (A12), product name "MS-203H" manufactured by Kaneka Corporation, number average molecular weight (Mn): 17000, molecular weight Distribution (Mw/Mn): 1.18, average number of methyldimethoxysilyl groups per molecule: 1.3]
- A polyalkylene oxide containing a methyldimethoxysilyl group and having a main chain skeleton made of polypropylene oxide [polyalkylene oxide (A13), product name "Excester S2420" manufactured by AGC Corporation, number average molecular weight (Mn): 17000, molecular weight Distribution (Mw/Mn): 1.41, average number of methyldimethoxysilyl groups per molecule: 1.6]
Moreover, none of the polyalkylene oxides (A11) to (A13) contained a (meth)acrylic acid ester unit containing a polyethylene oxide chain.

[Acrylic polymer having a hydrolyzable silyl group (A2)]
- An acrylic polymer containing a dimethoxysilyl group and having a main chain skeleton composed of a polymer of an acrylic monomer [acrylic polymer (A21), trade name "SA420S" manufactured by Kaneka Corporation, number average molecular weight: 20000 , molecular weight distribution (Mw/Mn): 1.2, having dimethoxysilyl groups at both ends of the main chain, average number of dimethoxysilyl groups per molecule: 1.6, butyl acrylate units and stearyl acrylate units Total content of butyl acrylate units and stearyl acrylate units, including: 90% by mass or more]
・Acrylic polymer containing a dimethoxysilyl group and having a main chain skeleton that is a polymer of an acrylic monomer [acrylic polymer (A22), trade name “NE-4003B” manufactured by Soken Kagaku Co., Ltd., number average Molecular weight: 17500, molecular weight distribution (Mw/Mn): 2.3, average number of methyldimethoxysilyl groups per molecule: 1.6, butyl acrylate units, 2-ethylhexyl acrylate units and methacrylic acid 3-( Total content of butyl acrylate units and 2-ethylhexyl acrylate units including methyldimethoxysilyl)propyl units: 95% by mass or more]
Neither of the acrylic polymers (A21) and (A22) had a chain containing polyalkylene oxide in the molecule.

[Mineral (B)]
・ Feldspar (average particle size: 5 μm, nepheline cyanite trade name “NESPER” manufactured by Shiraishi Calcium Co., Ltd., containing aluminum silicate)
・Kaolinite (containing aluminum silicate)
・Zeolite (containing aluminum silicate)

[(Meth) acrylic acid ester polymer (C)]
・ A (meth) acrylic acid ester polymer containing a (meth) acrylic acid ester unit having a polyethylene oxide chain (trade name “HAS-6” manufactured by Toagosei Co., Ltd., methoxy polyethylene glycol methacrylate and 3-methacryloxypropyl trimethoxy Silane copolymer [copolymer of methoxypolyethylene glycol methacrylate and 3-(trimethoxysilyl)propyl methacrylate], average number of hydrolyzable silyl groups per molecule: 0.14, number average molecular weight ( Mn): 2000)

[Plasticizer]
・ (Meth)acrylic polymer (D) having a hydrolyzable silyl group (product name “Alphon US6100” manufactured by Toagosei Co., Ltd., 2-ethylhexyl acrylate, methyl methacrylate and 3-(trimethoxy)propyl methacrylate) Copolymer [copolymer of 2-ethylhexyl acrylate, methyl methacrylate and 3-methacryloxypropyltrimethoxysilane], containing trimethoxysilyl groups as hydrolyzable silyl groups, not containing chains containing polyethylene oxide, number Average molecular weight (Mn): 1500)

[Silanol condensation catalyst]
・dioctyl tin oxide

[Aminosilane compound]
・ Aminosilane compound (N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, product name “KBM-603” manufactured by Shin-Etsu Chemical 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 (product name “Whiten SB” manufactured by Shiraishi Calcium Co., Ltd., average particle size: 2.0 μm)

[Dehydrating agent]
Dehydrating agent (vinyltrimethoxysilane, product name “KBM-1003” manufactured by Shin-Etsu Chemical Co., Ltd.)

[Antioxidant]
・ Hindered phenol antioxidant (product name “Irganox 1010” manufactured by BASF Japan)

[Ultraviolet absorber]
・ Benzotriazole-based UV absorber (manufactured by BASF Japan, product name “Tinuvin 326”)

(Examples 1 to 6 and Comparative Example 1)
An organic polymer (A) having a hydrolyzable silyl group, a mineral (B), a (meth)acrylic acid ester polymer (C), a (meth)acrylic polymer having a hydrolyzable silyl group (D), A silanol condensation catalyst, an aminosilane compound, a filler, a dehydrating agent, a hindered phenol-based antioxidant, and a benzotriazole-based ultraviolet absorber were adjusted to the blending amounts shown in Table 1, respectively, and the pressure was reduced in a sealed stirrer. A curable composition was obtained by mixing until uniform.

The obtained curable composition was measured for plane tensile strength and antifouling properties in the following manner, and the results are shown in Table 1.

[Compressive strength]
A curable composition was used to bond the slates together. A slate plate having a length of 12 mm, a width of 50 mm, and a thickness of 1.0 mm was used. After applying the curable composition to the surface of the slate so that the adhesion width after adhesion is 12 mm, the adhesion height is 10 mm, and the adhesion thickness is 0.3 mm, another slate plate is superimposed and the temperature is 23 ° C. And by curing the curable composition for 7 days in an environment with a relative humidity of 50%, a test piece was obtained in which two slate plates were bonded and integrated by the cured product of the curable composition. Using this specimen, a universal tensile tester (manufactured by Instron) was used to perform a tensile test at a speed of 3 mm/min. It was measured.

[Elongation at maximum load (initial)]
Using the curable composition, an H-type specimen was produced according to JIS A1439 5.17 (2010). Specifically, two anodized aluminum plates (length 50 mm x width 50 mm, thickness 5 mm) are used, and a spacer is sandwiched between these aluminum plates to create a rectangular parallelepiped space (length 12 mm x width 50 mm) in the center between the plates. x height 12 mm). 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 under an atmosphere of 23° C. and 50% relative humidity. After that, the curable composition was further left for 14 days in an atmosphere of 30° C. and 50% relative humidity. By curing and curing the curable composition, an H-shaped specimen was produced in which two plates were bonded and integrated by the cured product of the curable composition.

Then, the prepared H-shaped specimen 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 5.20.4 (2010). Elongation under load [%] was measured. Furthermore, after the tensile test was completed, the fracture form of the cured product of the curable composition was visually observed and evaluated according to the following criteria. The results obtained are shown in the "Initial" column in Table 1, respectively.

[Elongation at maximum load (90°C for 3 months)]
An H-type specimen was prepared in the same manner as above. After leaving the prepared H-type test piece in an atmosphere of 90°C and 50% relative humidity for 3 months, the H-type test piece was taken out and left in an atmosphere of 23°C and 50% relative humidity for an additional 24 hours. . After that, in an atmosphere of 23 ° C. and a relative humidity of 50%, a tensile test at a tensile speed of 50 mm / min was performed in accordance with JIS A1439 5.20.4 (2010), and the elongation at maximum load [%] was It was measured. Furthermore, after the tensile test was completed, the fracture form of the cured product of the curable composition was visually observed and evaluated according to the following criteria. The obtained results are described in the column of "90°C for 3 months" in Table 2, respectively.

The retention rate of the elongation at maximum load after the heat resistance test was calculated based on the following formula, and the results are shown in the "Retention rate" column.
Retention rate after heat resistance test at maximum load elongation (%)
= 100 x (elongation at maximum load for 3 months at 90°C)/(initial elongation at maximum load)

The evaluation criteria for the fracture form of the cured product of the curable composition are, after the tensile test is completed, the cohesive failure of the cured product of the curable composition is defined as "CF", and the cured product of the curable composition has interfacial failure. was designated as "AF".

In addition, "cohesive failure of the cured product" means a state in which the cured product itself is destroyed in a tensile test. "Interfacial failure of the cured product" means a state of peeling at the interface between the anodized aluminum plate and the cured product in a tensile test. The higher the adhesive force of the cured product of the curable composition, the more cohesive failure occurs, and the lower the adhesive force of the cured product of the curable composition, the more interfacial failure.

[Contamination (occurrence of rain streak stains)]
The curable composition was applied to a release-treated polyethylene terephthalate (PET) substrate in an atmosphere of 23° C. to a thickness of 2 mm and cured for 4 weeks, thereby forming a curable composition. A sheet-like test piece composed of the cured product was produced on the PET substrate.

Next, after peeling off the PET substrate from the sheet-like specimen, only the sheet-like specimen was attached to an aluminum plate to obtain a laminate. After that, the laminate was exposed outdoors (Koka City, Shiga Prefecture) for 3 months with the surface of the sheet-shaped test body vertical. Three months after the exposure, the surface condition of the sheet-like specimen was visually observed and evaluated according to the following criteria. The results are shown in the "Staining" column of Table 1.
◯: No rain streak stains occurred.
Δ: Slight rain streak staining occurred, but no problem in actual use.
x: Stained with rain streaks, and was in a considerably dirty state.

Claims (7)

an organic polymer (A) having a hydrolyzable silyl group;
a mineral (B) containing aluminum silicate;
A curable composition comprising a (meth)acrylic acid ester-based polymer (C) containing (meth)acrylic acid ester units having a polyethylene oxide chain. 2. The curable composition according to claim 1, wherein the mineral (B) contains feldspars. 2. The curable composition according to claim 1, comprising a (meth)acrylic polymer (D) having a hydrolyzable silyl group. 4. The curable composition according to claim 3, wherein the (meth)acrylic polymer (D) having a hydrolyzable silyl group has a number average molecular weight of 10,000 or less. The organic polymer (A) having a hydrolyzable silyl group includes a polyalkylene oxide (A1) having a hydrolyzable silyl group and an acrylic polymer having a number average molecular weight exceeding 10,000 and having a hydrolyzable silyl group ( A2). The curable composition of claim 4, comprising: 5. Polyalkylene oxide having a hydrolyzable silyl group (A1) has a number average molecular weight (Mn) of 15000 or more and a molecular weight distribution (Mw/Mn) of 1.4 or less. The curable composition according to . 6. The curable composition according to claim 5, wherein the acrylic polymer (A2) having a number average molecular weight of more than 10,000 and having a hydrolyzable silyl group does not have a polyalkylene oxide chain.