JP2016210840A - Curable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable composition which exhibits excellent tensile shear adhesive strength after curing and is also excellent in repeated load resistance.SOLUTION: The curable composition of the present invention contains: a polyoxyalkylene polymer containing a crosslinkable silyl group and having a number average molecular weight of 15,000-50,000 and a molecular weight distribution (weight average molecular weight (Mw)/number average molecular weight (Mn)) of 1.3 or less; a methoxy group-containing silyl group-modified (meth)acrylate polymer; and an aminosilane coupling agent.SELECTED DRAWING: None

Description

  The present invention relates to a curable composition.

  A rain gutter for receiving and flowing rain water is composed of gutter members such as eaves, a water collector, a call, a gutter, and a joint (for example, elbow, cheese, etc.). These gutter members are formed into a predetermined length for transportation, and gutters are formed by joining and assembling gutter members at a construction site. As a constituent material of the gutter member, for example, a synthetic resin having excellent weather resistance such as vinyl chloride resin, acrylic resin, ASA resin, and AES resin is used.

  Conventionally, a solvent-type adhesive has been used for joining rain gutter members. The solvent contained in the solvent-type adhesive dissolves or swells the synthetic resin that forms the receiving port or the insertion port of the gutter member, thereby firmly bonding the constituent members.

  However, in the case of solvent-based adhesives, there is a risk of plasticizing the rain gutter member due to penetration of the solvent, deterioration of the working environment due to volatilization of the solvent, risk of fire or explosion, and so on. It is desired to use an adhesive having a very low solvent content for joining the members.

  On the other hand, a curable composition containing a polyoxyalkylene polymer having a hydrolyzable silyl group as a main component is known as an adhesive having an extremely low solvent content (for example, Patent Document 1). Such a curable composition cures even at room temperature by hydrolyzable silyl groups forming a siloxane bond by hydrolysis and dehydration condensation reactions with moisture such as moisture, thereby eliminating the need for a solvent. Can be demonstrated.

JP 2008-280435 A

  However, in the assembled rain gutter, a large tensile shear stress is generated at the junction between the rain gutter members, but the conventional curable composition can exhibit an excellent adhesive strength against the tensile shear stress. Since it was not possible, it could not be used for joining rain gutter members.

  Therefore, an object of the present invention is to provide a curable composition that exhibits excellent tensile shear adhesive strength after curing and also has excellent resistance to repeated load.

  The curable composition of the present invention has a crosslinkable silyl group, a number average molecular weight of 15,000 to 50,000, and a molecular weight distribution (weight average molecular weight (Mw) / number average molecular weight (Mn)) of 1.3 or less. It comprises an oxyalkylene polymer, a methoxy group-containing silyl group-modified (meth) acrylate polymer, and an aminosilane coupling agent.

  In the curable composition, the main chain skeleton of the methoxy group-containing silyl group-modified (meth) acrylate polymer is a copolymer of methyl (meth) acrylate, butyl acrylate and butyl methacrylate.

  The curable composition of the present invention is cured by moisture in the air or moisture contained in the adherend, and forms a cured product having excellent tensile shear adhesive strength and resistance to repeated loading.

  The curable composition of the present invention contains a polyoxyalkylene polymer, a methoxy group-containing silyl group-modified (meth) acrylate polymer, and an aminosilane coupling agent.

[Polyoxyalkylene polymer]
In the polyoxyalkylene polymer having a crosslinkable silyl group, the main chain has a general formula:-(R-O) _n- (wherein R represents an alkylene group having 1 to 14 carbon atoms, n is A polymer containing a repeating unit represented by the number of repeating units and a positive integer is preferred. The main chain skeleton of the polyoxyalkylene polymer may be composed of only one type of repeating unit, or may be composed of two or more types of repeating units.

  The main chain skeleton of the polyoxyalkylene polymer includes polyoxyethylene, polyoxypropylene, polyoxybutylene, polyoxytetramethylene, polyoxyethylene-polyoxypropylene copolymer, and polyoxypropylene-polyoxybutylene copolymer. Examples thereof include polymers, and polyoxypropylene is preferable.

  The polyoxyalkylene polymer has a crosslinkable silyl group. As the crosslinkable silyl group, for example, a condensation reaction may be performed by using a catalyst or the like, if necessary, in the presence of moisture or a crosslinker such as a silicon-containing group or silanol group having a hydrolyzable group bonded to a silicon atom. Refers to a group that yields

  Examples of the crosslinkable silyl group include trimethoxysilyl group, methyldimethoxysilyl group, dimethylmethoxysilyl group, triethoxysilyl group, methyldiethoxysilyl group, alkoxysilyl group such as dimethylethoxysilyl group, and trichlorosilyl group. Examples include a silyl group to which a halogen is bonded, an alkoxysilyl group is preferable, and a methyldimethoxysilyl group is more preferable.

  The polyoxyalkylene polymer may further have a urethane bond in addition to the crosslinkable silyl group. The urethane bond can impart polarity to the polyoxyalkylene polymer, thereby imparting excellent tensile shear adhesive strength and resistance to repeated loads to a cured product obtained by curing the curable composition. .

  The polyoxyalkylene polymer may have a crosslinkable silyl group via a urethane bond at both ends of the polyoxyalkylene chain, or it may be crosslinkable without a urethane bond at both ends of the polyoxyalkylene chain. It may have a silyl group.

  The polyoxyalkylene polymer having a crosslinkable silyl group via a urethane bond at both ends of the polyoxyalkylene chain includes, for example, a prepolymer having hydroxyl groups at both ends of the polyoxyalkylene chain, a crosslinkable silyl group, and It is obtained by reacting with a compound having an isocyanate group.

  Examples of the prepolymer having hydroxyl groups at both ends of the polyoxyalkylene chain include polyoxyethylene glycol, polyoxypropylene glycol, polyoxybutylene glycol, polyoxytetramethylene glycol, polyoxyethylene-polyoxypropylene glycol, and polyoxyethylene Examples include propylene-polyoxybutylene glycol.

  Examples of the compound having a crosslinkable silyl group and an isocyanate group include 1-isocyanate methyltrimethoxysilane, 2-isocyanateethyltrimethoxysilane, 3-isocyanatepropyltrimethoxysilane, 3-isocyanatebutyltrimethoxysilane, 3-isocyanatepentyltril. Examples include methoxysilane and 1-isocyanatopropyltrimethoxysilane.

  In order to synthesize a polyoxyalkylene polymer having a crosslinkable silyl group via a urethane bond at both ends of the polyoxyalkylene chain, a prepolymer having a hydroxy group at both ends of the polyoxyalkylene chain and a crosslinkable silyl Mixing a compound having a group and an isocyanate group to obtain a mixture, and stirring the mixture to react the hydroxy group of the prepolymer with the isocyanate group of the compound to form a urethane bond. it can. Moreover, reaction can be accelerated | stimulated by stirring the said mixture, heating.

  A polyoxyalkylene polymer having a crosslinkable silyl group without a urethane bond at both ends of the polyoxyalkylene chain is, for example, an oxyalkylene polymer having a functional group such as a hydroxyl group at the terminal. It is produced by reacting an organic compound having an active group and an unsaturated group that are reactive to a functional group, and then hydrolylating the resulting reaction product with hydrosilane having a hydrolyzable group. be able to.

  The number average molecular weight of the polyoxyalkylene polymer is 15000 to 50000, preferably 20000 to 40000. When the number average molecular weight of the polyoxyalkylene polymer is 50000 or less, the cured product of the curable composition has excellent tensile shear adhesive strength. When the number average molecular weight of the polyoxyalkylene polymer is 15000 or more, the cured product of the curable composition has excellent tensile shear adhesive strength and resistance to repeated loads.

  The molecular weight distribution (weight average molecular weight (Mw) / number average molecular weight (Mn)) of the polyoxyalkylene polymer is 1.3 or less, preferably 1.2 or less. According to the polyoxyalkylene polymer having a molecular weight distribution of 1.3 or less, the cured product of the curable composition has excellent tensile shear adhesive strength and resistance to repeated loads.

  In the present invention, the number average molecular weight and the weight average molecular weight of the polyoxyalkylene polymer are values converted to polystyrene measured by a GPC (gel permeation chromatography) method. Specifically, 6 to 7 mg of a polyoxyalkylene polymer is sampled, and after the collected polyoxyalkylene polymer is supplied to a test tube, 0.05% by mass of BHT (dibutylhydroxytoluene) is added to the test tube. An o-DCB (orthodichlorobenzene) solution containing is added to dilute the polyoxyalkylene polymer to a concentration of 1 mg / mL to prepare a diluted solution.

  The dilution liquid is shaken for 1 hour at a rotation speed of 25 rpm at 145 ° C. using a dissolution filter, and the polyoxyalkylene polymer is dissolved in an o-DCB solution containing BHT to obtain a measurement sample. . Using this measurement sample, the number average molecular weight and the weight average molecular weight of the polyoxyalkylene polymer can be measured by the GPC method.

The number average molecular weight and the weight average molecular weight in the polyoxyalkylene polymer can be measured, for example, with the following measuring apparatus and measurement conditions.
Product name "HLC-8121GPC / HT" manufactured by TOSOH
Measurement conditions Column: TSKgelGMHHR-H (20) HT x 3
TSKguardcolumn-HHR (30) HT x 1
Mobile phase: o-DCB 1.0 mL / min
Sample concentration: 1 mg / mL
Detector: Bryce refractometer
Reference material: Polystyrene (Molecular weight: 500-8420000, manufactured by TOSOH)
Elution conditions: 145 ° C
SEC temperature: 145 ° C

  The viscosity at 25 ° C. of the polyoxyalkylene polymer is preferably 5,000 to 200,000 mPa · s, more preferably 5,000 to 100,000 mPa · s, and particularly preferably 10,000 to 30,000 mPa · s. When the viscosity at 25 ° C. of the polyoxyalkylene polymer is 200000 mPa · s or less, the cured product of the curable composition has excellent strength, and the cured product of the curable composition has excellent tensile shear adhesive strength. Have When the viscosity of the polyoxyalkylene polymer at 25 ° C. is 5000 mPa · s or more, the cured product of the curable composition has excellent tensile shear adhesive strength and resistance to repeated loads.

  In the present invention, the viscosity of the polyoxyalkylene polymer at 25 ° C. is determined according to JIS K1557, after being allowed to stand at 25 ° C. for 24 hours or more, and then using a BM viscometer under the condition of 12 rpm. Can be measured.

  A commercially available polyoxyalkylene polymer having a crosslinkable silyl group can be used. For example, as a polyoxyalkylene polymer having a main chain skeleton of polyoxypropylene, having a dimethoxysilyl group at the end of the main chain skeleton and having no urethane bond, for example, trade name “ESS4530 manufactured by Asahi Glass Co., Ltd.” Or the like.

[Methoxy group-containing silyl group-modified (meth) acrylate polymer]
As the main chain skeleton of the methoxy group-containing silyl group-modified (meth) acrylate polymer, radical polymerization of (meth) acrylate monomers such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, etc. The (meth) acrylate polymer obtained is mentioned. In addition, (meth) acrylate means a methacrylate or an acrylate. The methoxy group-containing silyl group-modified (meth) acrylate polymer may be simply referred to as “(meth) acrylate polymer”.

  Specific examples of the (meth) acrylate monomer constituting the main chain skeleton of the (meth) acrylate polymer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and n-butyl (meth) ) Acrylate, tert-butyl (meth) acrylate, i-butyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) ) Acrylate, isomyristyl (meth) acrylate, stearyl (meth) acrylate, isobornyl (meth) acrylate, benzyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate Rate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, hexanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, tri Methylolpropane tri (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, epoxy (meth) acrylate, polyester (meta ) Acrylate, urethane (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylic 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 3- Hydroxy-3-methylbutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2- [acryloyloxy] ethyl-2-hydroxyethylphthalic acid, and 2- [acryloyloxy] ethyl-2-hydroxy And propyl phthalic acid. These (meth) acrylate monomers may be used alone or in combination of two or more.

  Other monomers can be copolymerized in the main chain skeleton of the (meth) acrylate polymer. Examples of such monomers include styrene, indene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, p-chloromethylstyrene, p-methoxystyrene, p-tert-butoxystyrene, and divinylbenzene. Styrene derivatives, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl benzoate, vinyl cinnamate and other compounds having a vinyl ester group, maleic anhydride, N-vinylpyrrolidone, N-vinylmorpholine, ( (Meth) acrylonitrile, (meth) acrylamide, N-cyclohexylmaleimide, N-phenylmaleimide, N-laurylmaleimide, N-benzylmaleimide, n-propylvinylether, n-butylvinylether, isobutylvinylether, tert-butyl Ru vinyl ether, tert-amyl vinyl ether, cyclohexyl vinyl ether, 2-ethylhexyl vinyl ether, dodecyl vinyl ether, octadecyl vinyl ether, 2-chloroethyl vinyl ether, ethylene glycol butyl vinyl ether, triethylene glycol methyl vinyl ether, benzoic acid (4-vinyloxy) butyl, ethylene glycol Divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, butane-1,4-diol-divinyl ether, hexane-1,6-diol-divinyl ether, cyclohexane-1,4-dimethanol Divinyl ether, di (4-vinyloxy) butyl isophthalate, glutar Di (4-vinyloxy) butyl acid, di (4-vinyloxy) butyl trimethylolpropane trivinyl ether, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, 6-hydroxyhexyl vinyl ether, cyclohexane-1,4-dimethanol Examples thereof include compounds having a vinyloxy group such as monovinyl ether, diethylene glycol monovinyl ether, 3-aminopropyl vinyl ether, 2- (N, N-diethylamino) ethyl vinyl ether, urethane vinyl ether, and polyester vinyl ether. These monomers may be used alone or in combination of two or more.

  Among them, as the main chain skeleton of the (meth) acrylate polymer, a copolymer of butyl (meth) acrylate and methyl (meth) acrylate is preferable, and a copolymer of methyl (meth) acrylate, butyl acrylate and butyl methacrylate. Are more preferable, and a copolymer of methyl methacrylate, butyl acrylate and butyl methacrylate is particularly preferable. According to the (meth) acrylate polymer whose main chain skeleton is composed of the above copolymer, the cured product of the curable composition has excellent tensile shear adhesive strength and resistance to repeated loading.

  When the main chain skeleton of the (meth) acrylate polymer is a copolymer of butyl (meth) acrylate and methyl (meth) acrylate, the content of butyl (meth) acrylate in the copolymer is 10 to 90. % By mass is preferable, and 50 to 80% by mass is more preferable. 10-90 mass% is preferable and, as for content of methyl (meth) acrylate in a copolymer, 20-50 mass% is more preferable. When the content of butyl (meth) acrylate is 10% by mass or more, the flexibility of the cured product of the curable composition is improved, and the cured product has excellent tensile shear adhesive strength and resistance to repeated loads. When the content of butyl (meth) acrylate is 90% by mass or less, the cured product of the curable composition has excellent strength, and the cured product has excellent tensile shear adhesive strength. When the content of methyl (meth) acrylate is 10% by mass or more, the cured product of the curable composition has excellent strength, and the cured product has excellent tensile shear adhesive strength. When the content of methyl (meth) acrylate is 90% by mass or less, the flexibility of the cured product of the curable composition is improved, and the cured product has excellent tensile shear adhesive strength and resistance to repeated loads.

  When the main chain skeleton of the (meth) acrylate polymer is a copolymer of methyl (meth) acrylate, butyl acrylate and butyl methacrylate, the content of methyl (meth) acrylate in the copolymer is from 10 to 80. % By mass is preferable, and 15 to 65% by mass is more preferable. 5-50 mass% is preferable and, as for content of butyl acrylate in a copolymer, 10-45 mass% is more preferable. 5-50 mass% is preferable and, as for content of butyl methacrylate in a copolymer, 10-45 mass% is more preferable. When the content of methyl (meth) acrylate is 10% by mass or more, the cured product of the curable composition has excellent adhesion to the synthetic resin and the rubber material, and the cured product is composed of the synthetic resin and the rubber material. Excellent tensile shear adhesive strength and resistance to repeated loading. When the content of methyl (meth) acrylate is 80% by mass or less, the cured product of the curable composition has excellent tensile shear adhesive strength. When the content of butyl acrylate is 5% by mass or more, the cured product of the curable composition has excellent flexibility, and the cured product has excellent tensile shear adhesive strength and resistance to repeated loads. When the content of butyl acrylate is 50% by mass or less, the cured product of the curable composition has excellent strength, and the cured product has excellent tensile shear adhesive strength. When the content of butyl methacrylate is 5% by mass or more, the compatibility with the polyoxyalkylene polymer is improved, the cured product of the curable composition has excellent strength, and the cured product has excellent tensile strength. Has shear bond strength. When the content of butyl methacrylate is 50% by mass or less, the cured product of the curable composition does not become too hard, and the cured product has excellent tensile shear adhesive strength.

  When the main chain skeleton of the (meth) acrylate polymer is a copolymer of methyl methacrylate, butyl acrylate and butyl methacrylate, the content of methyl methacrylate in the copolymer is preferably 10 to 80% by mass, 15 -65 mass% is more preferable. 5-50 mass% is preferable and, as for content of butyl acrylate in a copolymer, 10-45 mass% is more preferable. 5-50 mass% is preferable and, as for content of butyl methacrylate in a copolymer, 10-45 mass% is more preferable. When the content of methyl methacrylate is 10% by mass or more, the cured product of the curable composition has excellent adhesion to the synthetic resin and the rubber material, and the cured product is based on the synthetic resin and the rubber material. Excellent tensile shear bond strength and resistance to repeated loading. When the content of methyl methacrylate is 80% by mass or less, the cured product of the curable composition has excellent tensile shear adhesive strength. When the content of butyl acrylate is 5% by mass or more, the cured product of the curable composition has excellent flexibility, and the cured product has excellent tensile shear adhesive strength and resistance to repeated loads. When the content of butyl acrylate is 50% by mass or less, the cured product of the curable composition has excellent strength, and the cured product has excellent tensile shear adhesive strength. When the content of butyl methacrylate is 5% by mass or more, the compatibility with the polyoxyalkylene polymer is improved, the cured product of the curable composition has excellent strength, and the cured product has excellent tensile strength. Has shear bond strength. When the content of butyl methacrylate is 50% by mass or less, the cured product of the curable composition does not become too hard, and the cured product has excellent tensile shear adhesive strength.

  The polymerization method of the (meth) acrylate polymer is not particularly limited, and a known method can be used. For example, a free radical polymerization method, an anionic polymerization method, a cationic polymerization method, a UV radical polymerization method, a living anion polymerization method can be used. Various polymerization methods such as a combination method, a living cationic polymerization method, and a living radical polymerization method may be mentioned.

  The methoxy group-containing silyl group-modified (meth) acrylate polymer has a methoxy group-containing silyl group in the side chain or terminal of the main chain skeleton of all molecules or some molecules. By using the (meth) acrylate polymer in combination with the polyoxyalkylene polymer described above, the cured product of the curable composition has excellent tensile shear adhesive strength.

  A methoxy group-containing silyl group refers to a silicon-containing group having a methoxy group bonded to a silicon atom. Examples of the methoxy group-containing silyl group include a trimethoxysilyl group, a methyldimethoxysilyl group, and a dimethylmethoxysilyl group. A trimethoxysilyl group and a methyldimethoxysilyl group are preferable, and a trimethoxysilyl group is more preferable.

  The number of methoxy groups bonded to the silicon atom of the methoxy group-containing silyl group is not limited and may be any of 1 to 3, but the cured product of the curable composition has excellent tensile shear adhesive strength. 2 and 3 are preferable, and 3 is more preferable.

  The average number of methoxy group-containing silyl groups per molecule of the (meth) acrylate polymer is preferably 0.5 to 3, and more preferably 1.5 to 2.5. According to the (meth) acrylate polymer in which the average number of methoxy group-containing silyl groups is within the above range, the cured product of the curable composition has excellent tensile shear adhesive strength.

The number average number of methoxy group-containing silyl groups per molecule in the (meth) acrylate polymer is the peak area derived from the methoxy group-containing silyl group in the (meth) acrylate polymer determined by ¹ H-NMR. The ratio can be calculated.

  The method for introducing the methoxy group-containing silyl group into the main chain skeleton of the (meth) acrylate polymer is not particularly limited. For example, after introducing an unsaturated group into the main chain skeleton of the (meth) acrylate polymer. A method of hydrosilylating by reacting hydrosilane having a methoxy group-containing silyl group can be used.

  The weight average molecular weight of the (meth) acrylate polymer is preferably 3000 to 50000, more preferably 5000 to 15000, and particularly preferably 5000 to 10,000. According to the (meth) acrylate polymer having a weight average molecular weight within the above range, the cured product of the curable composition has excellent tensile shear adhesive strength. In addition, the weight average molecular weight of a (meth) acrylate type polymer can be measured in the same way as the measuring method of the weight average molecular weight of the polyoxyalkylene type polymer mentioned above.

  The content of the (meth) acrylate polymer in the curable composition is preferably 5 to 300 parts by mass, more preferably 10 to 250 parts by mass, with respect to 100 parts by mass of the polyoxyalkylene polymer, and 30 to 200. Part by mass is particularly preferable, and 40 to 100 parts by mass is most preferable. When the content of the (meth) acrylate polymer in the curable composition is 5 parts by mass or more, the cured product of the curable composition has excellent tensile shear adhesive strength. When the content of the (meth) acrylate polymer in the curable composition is 300 parts by mass or less, the cured product of the curable composition has excellent tensile shear adhesive strength.

[Aminosilane coupling agent]
The curable composition contains an aminosilane coupling agent. The aminosilane coupling agent means a compound containing a silicon atom having an alkoxy group bonded in one molecule and a functional group containing a nitrogen atom. By using an aminosilane coupling agent, the cured product of the curable composition has excellent tensile shear adhesive strength.

  Specific examples of aminosilane coupling agents include 3-aminopropyltrimethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, and N- (2-aminoethyl) -3-aminopropyltrimethoxy. 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. These aminosilane coupling agents may be used alone or in combination of two or more.

  Among them, aminosilane coupling agents include 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, and N- (2-aminoethyl) -3-aminopropyltri Ethoxysilane is preferred, 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane is more preferred, and 3-aminopropyltrimethoxysilane is particularly preferred.

  0.5-10 mass parts is preferable with respect to 100 mass parts of polyoxyalkylene polymers, and, as for content of the aminosilane coupling agent in a curable composition, 1-5 mass parts is more preferable. When the content of the aminosilane coupling agent in the curable composition is 0.5 parts by mass or more, the cured product of the curable composition has excellent tensile shear adhesive strength. In addition, when the content of the aminosilane coupling agent in the curable composition is 10 parts by mass or less, the curing rate of the curable composition becomes too high, and the storage stability and handleability of the curable composition are lowered. There is a fear.

[silica]
It is preferable that the curable composition contains silica. By containing silica, the cured product of the curable composition has better tensile shear adhesive strength.

  Examples of silica include hydrophobic silica and hydrophilic silica, with hydrophobic silica being preferred.

  Examples of the hydrophobic silica include silica that is surface-treated with a silane compound containing a hydrophobic group such as a methyl group, a dimethyl group, and a trimethyl group.

  Preferable examples of the silane compound containing a hydrophobic group include silane compounds containing a methyl group and a halogen atom. Examples of the halogen atom include a chlorine atom and a bromine atom. Specific examples of the silane compound containing a methyl group and a halogen atom include dimethyldichlorosilane, trimethylchlorosilane, methyltrichlorosilane, benzyldimethylchlorosilane, and bromomethyldimethylchlorosilane. Of these, dimethyldichlorosilane is preferable.

  Usually, silica has silanol groups on its surface. Then, by treating the surface of the silica with a silane compound containing a methyl group and a halogen atom, the silanol group present on the silica surface reacts with the halogen atom contained in the silane compound, and the silica surface Hydrophobic silica is obtained by introducing a methyl group into. The silanol group means a hydroxy group (≡Si—OH) bonded directly to a silicon atom.

  According to the hydrophobic silica surface-treated with a silane compound containing a methyl group and a halogen atom, the cured product of the curable composition has a superior tensile shear adhesive strength.

  In addition, a well-known method is used as a method of performing the surface treatment of silica with a silane compound containing a hydrophobic group. For example, a method of mixing a silane compound containing a hydrophobic group and silica, or a method of applying or spraying a solution containing a silane compound containing a hydrophobic group on the surface of silica is used.

  The average primary particle diameter of silica is preferably 5 to 30 nm, and more preferably 10 to 20 nm. According to the silica having an average primary particle diameter of 5 nm or more, the dispersibility can be improved by suppressing the aggregation of the silica, and the cured product of the curable composition has a more excellent tensile shear adhesive strength. According to the silica having an average primary particle size of 30 nm or less, the viscosity of the resulting curable composition can be suppressed from becoming too high, and excellent thixotropic properties can be imparted to the curable composition. .

  In the present invention, the average primary particle diameter of silica can be measured according to the following procedure. Taking silica with a transmission electron microscope at a magnification of 50,000 to 100,000, measuring the primary particle diameter of 100 or more silicas from the obtained photographed image, and averaging the obtained values The average primary particle diameter of silica can be calculated. Note that the primary particle diameter of silica means the diameter of the smallest perfect circle that can surround the primary particles of silica.

BET specific surface area of silica is preferably ^{50~300m 2 / g, 100~200m 2 /} g is more preferable. When the BET specific surface area of silica is 50 m ² / g or more, the viscosity of the resulting curable composition can be prevented from becoming too high, and excellent thixotropy can be imparted to the curable composition. it can. When the BET specific surface area of the silica is 300 m ² / g or less, the aggregation of the silica can be suppressed and the dispersibility can be improved, and the cured product of the curable composition has a more excellent tensile shear adhesive strength.

  In the present invention, the BET specific surface area of silica can be measured by a method based on DIN 66131.

  5-100 mass parts is preferable with respect to 100 mass parts of polyoxyalkylene polymers, and, as for content of the silica in a curable composition, 8-50 mass parts is more preferable. When the content of silica in the curable composition is 5 parts by mass or more, the cured product of the curable composition has more excellent tensile shear adhesive strength. When the content of silica in the curable composition is 100 parts by mass or less, the viscosity of the resulting curable composition can be prevented from becoming too high, and thixotropic properties excellent in the curable composition can be achieved. Can be granted.

[Plasticizer]
The curable composition may contain a plasticizer. Plasticizers include: dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dinormal hexyl phthalate, bis (2-ethylhexyl) phthalate, dinormal octyl phthalate, diisononyl phthalate, dinonyl phthalate, Phthalates such as diisodecyl phthalate, diisoundecyl phthalate, and bisbutylbenzyl phthalate; non-aromatic dibasic esters such as dioctyl adipate, dioctyl sebacate, dibutyl sebacate, and isodecyl succinate; butyl oleate; And aliphatic esters such as methyl acetylricinoleate; esters of polyalkylene glycols such as diethylene glycol dibenzoate, triethylene glycol dibenzoate, and pentaerythritol ester; Tricresyl phosphate, and phosphoric acid esters such as tributyl phosphate. These plasticizers may be used alone or in combination of two or more.

  Especially, as a plasticizer, a phthalic acid ester is used preferably and diisodecyl phthalate is more preferable.

  10-100 mass parts is preferable with respect to 100 mass parts of polyoxyalkylene polymers, and, as for content of the plasticizer in a curable composition, 20-70 mass parts is more preferable. When the content of the plasticizer in the curable composition is 10 parts by mass or more, the cured product of the curable composition has excellent elongation, and the cured product has excellent tensile shear adhesive strength and repeated load resistance. Have When the content of the plasticizer in the curable composition is 100 parts by mass or less, the cured product of the curable composition has excellent strength, and the cured product has excellent tensile shear adhesive strength.

[Dehydrating agent]
The curable composition preferably further contains a dehydrating agent. According to the dehydrating agent, when the curable composition is stored, the curable composition can be prevented from being cured by moisture contained in the air.

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

  The content of the dehydrating agent in the curable composition is preferably 0.5 to 20 parts by mass, more preferably 1 to 10 parts by mass, and 1 to 5 parts by mass with respect to 100 parts by mass of the polyoxyalkylene polymer. Particularly preferred. The storage stability of a curable composition can be improved as content of the dehydrating agent in a curable composition is 0.5 mass part or more. When the content of the dehydrating agent in the curable composition is 20 parts by mass or less, the curability of the curable composition is improved.

[Weatherproof stabilizer]
It is preferable that the curable composition further contains a weather stabilizer. Preferred examples of the weathering stabilizer include an antioxidant, an ultraviolet absorber, and a light stabilizer. By using these weather stabilizers, the weather resistance of the cured product of the curable composition can be improved. A weathering stabilizer may be used independently or 2 or more types may be used together.

  Examples of the antioxidant include hindered phenolic antioxidants, monophenolic antioxidants, bisphenolic antioxidants, and polyphenolic antioxidants. Of these, hindered phenol antioxidants are preferred. Specific examples of the hindered phenol antioxidant include pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (melting point: 118 ° C.), octadecyl-3- (3 , 5-di-tert-butyl-4-hydroxyphenyl) propionate] (melting point 52 ° C.), and N, N′-hexane-1,6-diylbis [3- (3,5-di-tert-butyl-4 -Hydroxyphenylpropionamide)] (melting point: 158 ° C.). Moreover, as a hindered phenolic antioxidant, commercial items, such as a brand name "IRGANOX (trademark) 1135" (melting | fusing point 5 degreeC) by BASF, can also be used.

  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 with respect to 100 parts by mass of the polyoxyalkylene polymer. ˜5 parts by mass is particularly preferred.

  Examples of ultraviolet absorbers include benzotriazole ultraviolet absorbers and benzophenone ultraviolet absorbers. Of these, benzotriazole-based ultraviolet absorbers are preferred. Specific examples of the benzotriazole ultraviolet absorber include 2- (2H-benzotriazol-2-yl) -p-cresol (melting point 130 ° C.), 2- (2H-benzotriazol-2-yl) -4- 6-bis (1-methyl-1-phenylethyl) phenol (melting point 139 ° C.), 2- [5-chloro (2H) -benzotriazol-2-yl] -4-methyl-6- (tert-butyl) phenol (Melting point 139 ° C.), 2- (2H-benzotriazol-2-yl) -4,6-di-tert-pentylphenol (melting point 84 ° C.), and 2- (2H-benzotriazol-2-yl) -4 -(1,1,3,3-tetramethylbutyl) phenol (melting point 104 ° C.) and the like. Moreover, as a benzotriazole type ultraviolet absorber, commercial items, such as a brand name "TINUVIN (trademark) 384-2" (melting | fusing point 10 degrees C or less) made from BASF, can also be used.

  The content of the ultraviolet absorber in the curable composition is preferably 0.1 to 20 parts by mass, more preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the polyoxyalkylene polymer. ˜5 parts by mass is particularly preferred.

  Examples of the light stabilizer include hindered amine light stabilizers. Specifically, a mixture of bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate (melting point: 10 ° C. or lower) ), Dibutylamine, 1,3,5-triazine, N, N′-bis (2,2,6,6-tetramethyl-4-piperidyl-1,6-hexamethylenediamine and N- (2,2, Polycondensation product with 6,6-tetramethyl-4-piperidyl) butylamine (melting point 135 ° C.), 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}] (melting point 118 ° C), dimethyl succinate Such as polycondensates of 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol (mp 63 ° C.) and the like.

  The content of the light stabilizer in the curable composition is preferably 0.5 to 20 parts by mass, more preferably 1 to 10 parts by mass, and 1 to 5 parts by mass with respect to 100 parts by mass of the polyoxyalkylene polymer. Is particularly preferred.

  In addition to the components described above, the curable composition may contain other additives such as a thixotropic agent, a pigment, a dye, and an anti-settling agent. Further, the curable composition may contain a small amount of a solvent as long as the effect is not impaired. Other additives and solvents may be used alone or in combination of two or more.

  Any thixotropic agent may be used as long as it can develop thixotropic properties in the curable composition. Preferred examples of the thixotropic agent include hydrogenated castor oil, fatty acid bisamide, and fumed silica.

  0.1-200 mass parts is preferable with respect to 100 mass parts of polyoxyalkylene polymers, and, as for content of the thixotropic imparting agent in a curable composition, 1-150 mass parts is more preferable. When the content of the thixotropic agent in the curable composition is 0.1 parts by mass or more, excellent thixotropic properties can be imparted to the curable composition. When the content of the thixotropic agent in the curable composition is 200 parts by mass or less, the viscosity of the curable composition is suppressed from becoming too high, and the curable composition has excellent handleability.

[Silanol condensation catalyst]
Silanol condensation catalysts include dibutyltin dilaurate, dibutyltin oxide, dibutyltin diacetate, dibutyltin phthalate, bis (dibutyltin lauric acid) oxide, dibutyltin bis (acetylacetonate), dibutyltin bis (monoester maleate) , Tin octylate, dibutyltin octoate, dioctyltin oxide, dibutyltin bis (triethoxysilicate), dioctyltin dilaurate, bis (dibutyltin bistriethoxysilicate) oxide, dibutyltin oxybisethoxysilicate, and 1,1,3,3 Organotin compounds such as 3-tetrabutyl-1,3-dilauryloxycarbonyl-distannoxane; organotitanium compounds such as tetra-n-butoxy titanate and tetraisopropoxy titanate; 1 5,7-triazabicyclo [4.4.0] deca5-ene, 7-methyl-1,5,7-triazabicyclo [4.4.0] deca5-ene, 1,8-diazabicyclo [ 5.4.0] Undec-7-ene, 6-dibutylamino-1,8-diazabicyclo [5.4.0] undec-7-ene, 1,5-diazabicyclo [4.3.0] noner 5- And cycloamidine compounds such as ene; dibutylamine-2-ethylhexoate and the like. Other acidic catalysts and basic catalysts can also be used as the silanol condensation catalyst.

  The content of the silanol condensation catalyst in the curable composition is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the polyoxyalkylene polymer.

  In the curable composition, the crosslinkable silyl group of the polyoxyalkylene polymer and the (meth) acrylate polymer is hydrolyzed by moisture in the air or moisture contained in the adherend. It hardens | cures by decomposing | disassembling and dehydrating and forming a siloxane bond, and forms the hardened | cured material excellent in the adhesive force. The use of the curable composition is not particularly limited. However, since the curable composition can exhibit excellent tensile shear adhesive strength and repeated load resistance after curing, members to which tensile shear stress and repeated load are added at the joint portion. It is preferably used for joining. Specific examples of such applications include joining rain gutter members.

  The gutter is composed of gutter members such as eaves, a water collector, a call, a gutter, and a joint (eg, elbow, cheese, etc.). Examples of the material constituting the gutter member include synthetic resins such as vinyl chloride resin, acrylic resin, ASA resin, and AES resin, steel plates, glass fibers, and carbon fibers. Moreover, as a gutter member, the composite material which has the core part which consists of a steel plate, glass fiber, carbon fiber, a fiber reinforced plastic, etc., and the coating layer formed in at least one surface of this core part is also mentioned. . The coating layer preferably contains a synthetic resin such as a vinyl chloride resin, an acrylic resin, an ASA resin, and an AES resin.

  Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.

Each component used in the examples and comparative examples will be described.
[Polyoxyalkylene polymer]
Polyoxyalkylene polymer (A1) having a main chain skeleton of polyoxypropylene and having a methyldimethoxysilyl group at the end of the main chain skeleton without a urethane bond (viscosity at 25 ° C .: 23000 mPa · s Number average molecular weight: 20000, molecular weight distribution (Mw / Mn): 1.16, product name “ESS4530” manufactured by Asahi Glass Co., Ltd.)
Polyoxyalkylene polymer (A2) in which the main chain skeleton is polyoxypropylene and methyldimethoxysilyl groups are bonded to both ends of the main chain skeleton without a urethane bond (viscosity at 25 ° C .: 15000 mPa · s, number average molecular weight Mn: 18000, molecular weight distribution (Mw / Mn): 1.39, product name “ESS2420” manufactured by Asahi Glass Co., Ltd.)
Kaneka Corporation Silyl EST280)
Polyoxyalkylene polymer (A3) having a main chain skeleton of polyoxypropylene and having trimethoxysilyl groups at both ends of the main chain skeleton via urethane bonds (viscosity at 25 ° C .: 5000 mPa · s Number average molecular weight: 14000 Molecular weight distribution (Mw / Mn): 1.23, trade name “Desmosal (registered trademark) XP2749” manufactured by Bayer
[(Meth) acrylate polymer]
Copolymer of main chain skeleton of methyl methacrylate, n-butyl acrylate and n-butyl methacrylate (content of methyl methacrylate component: 60% by mass, content of n-butyl acrylate component: 20% by mass, n-butyl methacrylate (Meth) acrylate polymer (B1) (weight average molecular weight: 8200, 1 molecule) having a trimethoxysilyl group at the side chain or terminal of the main chain skeleton. Average number of trimethoxysilyl groups per unit: 2.2, trade name “Alfon RA-100” manufactured by Toagosei Co., Ltd.)
The main chain skeleton is a copolymer of n-butyl acrylate and methyl methacrylate (the content of n-butyl acrylate component: 75% by mass, the content of methyl methacrylate component: 25% by mass), and the side of the main chain skeleton (Meth) acrylate polymer (B2) having a trimethoxysilyl group at the chain or terminal (weight average molecular weight: 3200, average number of trimethoxysilyl groups per molecule: 0.9, Toagosei Co., Ltd. Product name "Alfon US-6110")
The main chain skeleton is a copolymer of n-butyl methacrylate and methyl methacrylate (content of n-butyl methacrylate component: 75 mass%, content of methyl methacrylate component: 25 mass%), and the side of the main chain skeleton (Meth) acrylate polymer (B3) having a trimethoxysilyl group at the chain or terminal (weight average molecular weight: 6500, average number of dimethoxysilyl groups per molecule: 0.9)
[Aminosilane coupling agent]
・ 3-Aminopropyltrimethoxysilane (trade name “KBM-903” manufactured by Shin-Etsu Chemical Co., Ltd.)
〔silica〕
Hydrophobic silica surface-treated with dimethyldichlorosilane (average primary particle size: 16 nm, BET specific surface area: 110 m ² / g, trade name “AEROSIL R972” manufactured by Evonik Degussa)
[Dehydrating agent]
・ Vinyltrimethoxysilane (trade name “KBM-1003” manufactured by Shin-Etsu Chemical Co., Ltd.)
〔Antioxidant〕
Hindered phenol antioxidant (pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], melting point 118 ° C., trade name “IRGANOX (registered trademark) 1010” manufactured by BASF ")
Benzotriazole-based ultraviolet absorber (2- [5-chloro (2H) -benzotriazol-2-yl] -4-methyl-6- (tert-butyl) phenol, melting point 139 ° C., trade name “TINUVIN” manufactured by BASF (Registered trademark) 326 ")
[Silanol condensation catalyst]
・ Dibutyltin dilaurate (product name “S-130” manufactured by Nitto Kasei Co., Ltd.)

(Examples 1-8, Comparative Examples 1-5)
Predetermined amounts of polyoxyalkylene polymers (A1) to (A3), (meth) acrylate polymers (B1) to (B3) shown in Table 1, 3-aminopropyltrimethoxysilane, hydrophobic silica, vinyl A raw material composition containing trimethoxysilane, hindered phenolic antioxidant, benzotriazole ultraviolet absorber and dibutyltin dilaurate was supplied to a stirrer. Next, after the inside of the stirrer was sealed, the raw material composition was uniformly mixed under reduced pressure to obtain a curable composition.

  The obtained curable composition was measured for tensile shear adhesive strength and resistance to repeated loading, and the results are shown in Table 1.

(Tensile shear adhesive strength)
The tensile shear bond strength of the curable composition to the test plate was measured according to JIS A5536.

  Specifically, two test plates (25 mm in width and 100 mm in length) are prepared, and the curable composition is applied to one end portion in the length direction of each test plate in an application area of 25 mm width × 25 mm length. did. Next, the two test plates were overlapped so that their length directions were parallel to each other to obtain a laminate. In addition, the one end part of the length direction in one test board and the other end part of the length direction in the other test board were made to mutually overlap.

The laminate was cured for 30 days in an atmosphere at a temperature of 23 ° C. and a relative humidity of 50% to cure the curable composition to obtain a test specimen. One end of each test piece of the test body was gripped and fixed to a tensile tester, and the tensile shear adhesive strength (N / mm ² ) was measured by pulling at a tensile speed of 50 mm / min.

  Ten test specimens were prepared in the same manner as described above, the tensile shear bond strength of each test specimen was measured, and the arithmetic average value thereof was taken as the tensile shear bond strength of the curable composition. The tensile shear adhesive strength was measured for each of the case where two polyvinyl chloride plates were used as the test plate and the case where two AES plates were used.

(Fatigue test)
A specimen was prepared in the same manner as the method for measuring tensile shear bond strength, and the specimen was cured in the same manner. The specimen was subjected to a fatigue test 100 times at a pull rate of 200 mm / min with a displacement of 10%. The case where the test piece did not break was evaluated as “◯”, and the case where it broke was evaluated as “x”.

Claims (2)

A polyoxyalkylene polymer having a crosslinkable silyl group and having a number average molecular weight of 15,000 to 50,000 and a molecular weight distribution (weight average molecular weight (Mw) / number average molecular weight (Mn)) of 1.3 or less, and a methoxy group A curable composition comprising a silyl group-modified (meth) acrylate polymer and an aminosilane coupling agent. The curable composition according to claim 1, wherein the main chain skeleton of the methoxy group-containing silyl group-modified (meth) acrylate polymer is a copolymer of methyl (meth) acrylate, butyl acrylate and butyl methacrylate. object.