JP6214442B2 - Curable composition - Google Patents

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.

  Then, an object of this invention is to provide the curable composition which can exhibit the outstanding tensile shear adhesive strength after hardening.

  The curable composition of the present invention comprises a polyoxyalkylene polymer (A) having a trimethoxysilyl group and having a urethane bond in the main chain skeleton, a trimethoxysilyl group and the main chain skeleton being methyl. It contains a (meth) acrylate polymer (B) composed of a copolymer of monomers containing (meth) acrylate, butyl acrylate, and butyl methacrylate, and an aminosilane coupling agent.

[Polyoxyalkylene polymer (A)]
The polyoxyalkylene polymer (A) having a trimethoxysilyl group has a main chain skeleton represented by the general formula: — (R—O) _n — (wherein R represents an alkylene group having 1 to 14 carbon atoms). , N is the number of repeating units and is a positive integer). 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 trimethoxysilyl group is a group formed by bonding three methoxy groups to a silicon atom.

  According to the polyoxyalkylene polymer (A) having a trimethoxysilyl group, the tensile shear bond strength of the curable composition after curing can be improved.

  As the main chain skeleton of the polyoxyalkylene polymer (A), polyoxyethylene, polyoxypropylene, polyoxybutylene, polyoxytetramethylene, polyoxyethylene-polyoxypropylene copolymer, and polyoxypropylene-poly Examples thereof include oxybutylene copolymers. Of these, polyoxypropylene is preferable.

  The polyoxyalkylene polymer (A) has a urethane bond in the main chain skeleton. The urethane bond can impart polarity to the polyoxyalkylene polymer (A) after curing, thereby improving the tensile shear adhesive strength of the curable composition after curing.

  The polyoxyalkylene polymer (A) preferably has a trimethoxysilyl group at both ends of the polyoxyalkylene chain via a urethane bond. According to the polyoxyalkylene polymer (A) having a urethane bond in the vicinity of the trimethoxysilyl group, the tensile shear bond strength of the curable composition after curing can be further improved.

  The polyoxyalkylene polymer (A) having a trimethoxysilyl 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, trimethoxy It can be obtained by reacting a compound having a silyl group and 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 trimethoxysilyl group and an isocyanate group include 1-isocyanate methyltrimethoxysilane, 2-isocyanateethyltrimethoxysilane, 3-isocyanatepropyltrimethoxysilane, 3-isocyanatobutyltrimethoxysilane, 3-isocyanatepentyltril. Examples include methoxysilane and 1-isocyanatopropyltrimethoxysilane.

  In order to synthesize a polyoxyalkylene polymer (A) having a trimethoxysilyl group via a urethane bond at both ends of the polyoxyalkylene chain, a prepolymer having hydroxy groups at both ends of the polyoxyalkylene chain; By mixing a compound having a trimethoxysilyl 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 be carried out. Moreover, reaction can be accelerated | stimulated by stirring the said mixture, heating.

  The number average molecular weight of the polyoxyalkylene polymer (A) is preferably 3,000 to 50,000, and more preferably 10,000 to 20,000. If the number average molecular weight of the polyoxyalkylene polymer (A) is too large, the viscosity of the resulting curable composition will increase, and the coating properties of the curable composition may be reduced. Moreover, when the number average molecular weight of a polyoxyalkylene type polymer (A) is too small, the hardened | cured material of the obtained curable composition may become weak, and there exists a possibility that the tensile shear adhesive strength of hardened | cured material may fall.

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

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

The number average molecular weight in the polyoxyalkylene polymer (A) can be measured by, for example, the following measuring apparatus and measuring conditions.
Product name “HLC-8121GPC / HT” manufactured by TOSOH
Measurement conditions Column: TSKgelGMHHR-H (20) HT x 3
TSK guard 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 (Molecular weight: 500-8420000, manufactured by TOSOH)
Elution conditions: 145 ° C
SEC temperature: 145 ° C

  In addition, the measurement of the weight average molecular weight of the (meth) acrylate polymer (B) described later can also be performed using the same method as described above.

  The viscosity at 25 ° C. of the polyoxyalkylene polymer (A) is preferably 1000 to 30000 mPa · s, more preferably 4000 to 25000 mPa · s, and particularly preferably 5000 to 15000 mPa · s. If the viscosity of the polyoxyalkylene polymer (A) is too high, the viscosity of the resulting curable composition will be high, and the coatability of the curable composition may be reduced. Moreover, when the viscosity of a polyoxyalkylene type polymer (A) is too low, the hardened | cured material of a curable composition will become weak, and there exists a possibility that the tensile shear adhesive strength of hardened | cured material may fall.

  In the present invention, the viscosity of the polyoxyalkylene polymer (A) at 25 ° C. is measured by using a BM viscometer in accordance with JIS K1557 after being left at 25 ° C. for 24 hours or more. Rotor NO. 4. It can be measured under the condition of 12 rpm.

  As the polyoxyalkylene polymer (A) containing a trimethoxysilyl group, a commercially available product can be used. For example, as a polyoxyalkylene polymer having a main chain skeleton of polyoxypropylene and having trimethoxysilyl groups at both ends of the main chain skeleton via urethane bonds, Desmosal (registered trademark) manufactured by Bayer XP2749 is mentioned.

[(Meth) acrylate polymer (B)]
The main chain skeleton of the (meth) acrylate polymer (B) is composed of a copolymer of monomers including methyl (meth) acrylate, butyl acrylate, and butyl methacrylate. According to the (meth) acrylate polymer (B) whose main chain skeleton is composed of the above copolymer, the tensile shear adhesive strength of the curable composition after curing can be improved. In addition, (meth) acrylate means a methacrylate and / or an acrylate.

  In the (meth) acrylate polymer (B), monomers used for the copolymer constituting the main chain skeleton are methyl (meth) acrylate, butyl acrylate, and butyl methacrylate, as well as other monomers. A monomer may be included. Examples of other monomers include styrene such as styrene, indene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, p-chloromethylstyrene, p-methoxystyrene, p-tert-butoxystyrene, and divinylbenzene. Derivatives, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl benzoate, vinyl cinnamate and other compounds having vinyl ester groups, maleic anhydride, N-vinylpyrrolidone, N-vinylmorpholine, (meta ) Acrylonitrile, (meth) acrylamide, N-cyclohexylmaleimide, N-phenylmaleimide, N-laurylmaleimide, N-benzylmaleimide, n-propylvinylether, n-butylvinylether, isobutylvinylether, tert-butylbi 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 di Vinyl 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-di Vinyl ether, di (4-vinyloxy) butyl isophthalate, di (glutaric acid) ( 4-vinyloxy) butyl, di (4-vinyloxy) butyltrimethylolpropane trivinyl ether, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, 6-hydroxyhexyl vinyl ether, cyclohexane-1,4-dimethanol monovinyl ether, Examples thereof include compounds having a vinyloxy group such as 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.

  The polymerization method of the (meth) acrylate polymer (B) 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, Various polymerization methods such as a living anionic polymerization method, a living cation polymerization method, and a living radical polymerization method may be mentioned.

  The (meth) acrylate polymer (B) has a trimethoxysilyl group in the side chain or terminal of the main chain skeleton. By using the (meth) acrylate polymer (B) in combination with the polyoxyalkylene polymer (A) described above, the tensile shear adhesive strength of the curable composition after curing can be improved.

  The average number of trimethoxysilyl groups per molecule of the (meth) acrylate polymer (B) is 1.5 to 3, particularly 1.8 to 2.5 trimethoxysilyl groups. It is preferable. The (meth) acrylate polymer (B) having an average number of trimethoxysilyl groups within the above range can improve the tensile shear adhesive strength of the curable composition after curing.

  The method for introducing a trimethoxysilyl group into the (meth) acrylate polymer (B) is not particularly limited. For example, co-polymerization of monomers including methyl (meth) acrylate, butyl acrylate, and butyl methacrylate. A method of hydrosilylating by introducing a hydrosilane having a trimethoxysilyl group after introducing an unsaturated group into the coalescence can be used.

  The weight average molecular weight of the (meth) acrylate polymer (B) is preferably 3,000 to 50,000, more preferably 5,000 to 15,000, and particularly preferably 5,000 to 10,000. According to the (meth) acrylate polymer (B) having a weight average molecular weight within the above range, the tensile shear adhesive strength of the curable composition after curing can be improved.

  The content of the (meth) acrylate polymer (B) in the curable composition is preferably 5 to 300 parts by weight, preferably 10 to 250 parts by weight, based on 100 parts by weight of the polyoxyalkylene polymer (A). Is more preferable, and 30 to 200 parts by weight are particularly preferable. If the content of the (meth) acrylate polymer (B) in the curable composition is too low, the tensile shear bond strength of the curable composition after curing may not be sufficiently improved. Moreover, when content of the (meth) acrylate type polymer (B) in a curable composition is too high, the hardened | cured material of the curable composition obtained may become weak, and the tensile shear adhesive strength of hardened | cured material may fall. There is.

[Aminosilane coupling agent]
The curable composition of the present invention 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 tensile shear bond strength of the curable composition after curing can be further improved.

  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 Preferred is ethoxysilane, and more preferred is N- (2-aminoethyl) -3-aminopropyltrimethoxysilane.

  The content of the aminosilane coupling agent in the curable composition is preferably 0.5 to 10 parts by weight and more preferably 1 to 5 parts by weight with respect to 100 parts by weight of the polyoxyalkylene polymer (A). If the content of the aminosilane coupling agent in the curable composition is too low, the tensile shear bond strength of the curable composition after curing may not be sufficiently improved. Further, if the content of the aminosilane coupling agent in the curable composition is too high, the curing rate of the curable composition becomes too high, and the storage stability and handleability of the curable composition may be reduced. .

[silica]
The curable composition of the present invention preferably contains silica. By using silica, the tensile shear bond strength of the curable composition after curing can be further improved.

  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 tensile shear adhesive strength of the curable composition after curing can be further improved.

  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. Silica having an average primary particle diameter of less than 5 nm is likely to aggregate and has low dispersibility, so that there is a possibility that sufficient effects cannot be obtained by adding silica. Moreover, when the average primary particle diameter of a silica exceeds 30 nm, there exists a possibility that the viscosity of the curable composition obtained may become high too much, or the thixotropy of a curable composition may fall.

  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. In silica having a BET specific surface area of less than 50 m ² / g, the viscosity of the resulting curable composition may be too high, or the thixotropy of the curable composition may be reduced. In addition, silica having a BET specific surface area of more than 300 m ² / g has low dispersibility, so that there is a possibility that sufficient effects cannot be obtained by adding silica.

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

  The content of silica in the curable composition is preferably 10 to 100 parts by weight and more preferably 10 to 50 parts by weight with respect to 100 parts by weight of the polyoxyalkylene polymer (A). If the content of silica in the curable composition is too low, there is a possibility that sufficient effects cannot be obtained due to the addition of silica. Moreover, when content of the silica in a curable composition is too high, there exists a possibility that the viscosity of the curable composition obtained may become high too much, or the thixotropy of a curable composition may fall.

[Plasticizer]
The curable composition of the present invention may contain a plasticizer. According to the plasticizer, the flexibility and elongation of the cured product of the curable composition can be improved, and as a result, the weather resistance of the cured product can be improved.

  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. According to these plasticizers, the weather resistance of the cured product of the curable composition can be further improved.

  The content of the plasticizer in the curable composition is preferably 10 to 100 parts by weight and more preferably 20 to 70 parts by weight with respect to 100 parts by weight of the polyoxyalkylene polymer (A). When content of the plasticizer in a curable composition is too low, the viscosity of the obtained curable composition will become high and there exists a possibility that the applicability | paintability of the said curable composition may fall. Moreover, when content of the plasticizer in a curable composition is too high, there exists a possibility that a plasticizer may ooze out on the hardened | cured material surface of a curable composition, and may reduce the weather resistance of hardened | cured material.

[Dehydrating agent]
The curable composition of the present invention 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 weight, more preferably 1 to 10 parts by weight, based on 100 parts by weight of the polyoxyalkylene polymer (A). 5 parts by weight is particularly preferred. If the content of the dehydrating agent in the curable composition is too low, the effect obtained by the dehydrating agent may not be sufficient. Moreover, when content of the dehydrating agent in a curable composition is too high, there exists a possibility that the sclerosis | hardenability of a curable composition may fall.

[Weatherproof stabilizer]
The curable composition of the present invention preferably further contains a weathering 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 individually by 1 type, and may use 2 or more types 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 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 weight, more preferably 0.3 to 10 parts by weight with respect to 100 parts by weight of the polyoxyalkylene polymer (A). 0.5 to 5 parts by weight is particularly preferable.

  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 TINUVIN (trademark) 384-2 (melting | fusing point 10 degrees C or less) by BASF, can also be used.

  0.1-20 weight part is preferable with respect to 100 weight part of polyoxyalkylene type polymers (A), and, as for content of the ultraviolet absorber in a curable composition, 0.1-10 weight part is more preferable. 0.5 to 5 parts by weight is particularly preferable.

  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 weight, more preferably 1 to 10 parts by weight, with respect to 100 parts by weight of the polyoxyalkylene polymer (A). ˜5 parts by weight is particularly preferred.

  The melting point of the weather stabilizer is preferably 10 ° C. or lower, and more preferably −20 to 5 ° C. According to the weather stabilizer having a melting point of 10 ° C. or lower, the weather resistance of the cured product of the curable composition can be further improved. In particular, the melting point of the light stabilizer is preferably 10 ° C. or less, and more preferably −20 to 5 ° C.

  When a weathering stabilizer having a melting point of 10 ° C. or less is used, the curable composition may contain a weathering stabilizer having a melting point of 10 ° C. or less and a weathering stabilizer having a melting point exceeding 10 ° C. The weather resistance of the cured product can be improved. However, it is preferable that the curable composition contains only a weathering stabilizer having a melting point of 10 ° C. or lower.

  In the present invention, the melting point of the weather stabilizer can be measured by the following method. The value is measured by a visual method according to JIS K0064 (1922).

  In addition to the components described above, the curable composition of the present invention may contain other additives such as a thixotropic agent, a pigment, a dye, and an anti-settling agent. Further, the curable composition of the present invention may contain a small amount of a solvent as long as the effect is not impaired. Another additive and solvent may be used individually by 1 type, and may use 2 or more types together.

  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.

  The content of the thixotropic agent in the curable composition is preferably 0.1 to 200 parts by weight and more preferably 1 to 150 parts by weight with respect to 100 parts by weight of the polyoxyalkylene polymer (A). If the content of the thixotropic agent in the curable composition is small, there is a possibility that thixotropic properties cannot be imparted to the curable composition. Moreover, when there is much content of the thixotropy imparting agent in a curable composition, there exists a possibility that the viscosity of a curable composition may become high and the handleability of a curable composition may fall.

[Silanol condensation catalyst]
In the curable composition of the present invention, the use of the silanol condensation catalyst can be omitted by using the polyoxyalkylene polymer (A) and the (meth) acrylate polymer (B) described above in combination. . In addition, when a silanol condensation catalyst is contained in the curable composition, the urethane bond contained in the main chain skeleton of the polyoxyalkylene polymer (A) is decomposed over time, and the tensile shear after curing. Adhesive strength and rubber hardness are reduced. When the curable composition does not contain a silanol condensation catalyst, decomposition of the urethane bond contained in the main chain skeleton of the polyoxyalkylene polymer (A) can be suppressed, and the curable composition is After curing, an appropriate rubber hardness (flexibility) capable of smoothly absorbing tensile shear stress can be maintained over a long period of time, and excellent tensile shear adhesive strength can be maintained over a long period of time.

  The silanol condensation catalyst is a dehydration condensation reaction between silanol groups formed by hydrolyzing the trimethoxysilyl group of the polyoxyalkylene polymer (A) and the (meth) acrylate polymer (B). It is a catalyst for promoting. The silanol group means a hydroxy group (≡Si—OH) bonded directly to a silicon atom. When the curable composition contains a silanol condensation catalyst, the cured product of the curable composition is accelerated to deteriorate, and the cured product loses flexibility and extensibility and becomes brittle. As a result, the cured product is cracked. There is a possibility that the generation and the adhesive strength may be reduced. Therefore, it is preferable that the curable composition of the present invention does not contain a 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 less than 0.001 part by weight and more preferably 0 part by weight with respect to 100 parts by weight of the polymer (A).

  Production of the curable composition of the present invention includes a polyoxyalkylene polymer (A) containing a trimethoxysilyl group, a (meth) acrylate polymer (B) containing a trimethoxysilyl group, and an aminoliran coupling. The agent and, if necessary, the silica, the weather stabilizer, other additives, and the solvent can be mixed by a predetermined weight ratio. Mixing is preferably performed under reduced pressure.

  The curable composition of the present invention has a polyoxyalkylene polymer (A) or a (meth) acrylate polymer (B) depending on moisture in the air or moisture contained in the adherend. The crosslinkable trimethoxysilyl group is cured by hydrolysis and dehydration condensation to form a siloxane bond, thereby giving a cured product having excellent adhesion. The use of such a curable composition of the present invention is not particularly limited. However, since the curable composition of the present invention can exhibit excellent tensile shear adhesive strength after curing, tensile shear stress is applied at the joint. It is preferably used for joining members. 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.

  In the curable composition of the present invention, the polyoxyalkylene polymer (A) having a trimethoxysilyl group and having a urethane bond in the main chain skeleton, and having a trimethoxysilyl group and the main chain skeleton being methyl By using a combination of a (meth) acrylate polymer (B) composed of a copolymer of monomers containing (meth) acrylate, butyl acrylate, and butyl methacrylate, and an aminosilane coupling agent, it is excellent after curing. High tensile shear bond strength can be exhibited.

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

(Examples 1-17, Comparative Examples 1-6)
A curable composition was prepared by mixing the following components so as to have the blending amounts shown in Tables 1 to 3, respectively, in a sealed stirrer while reducing the pressure until uniform.
component:
Polyoxyalkylene polymer (A1) 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. of 5,000 mPa S, Desmosal (registered trademark) XP2749, manufactured by Bayer
-Polyoxyalkylene polymer (A2) having a main chain skeleton of polyoxypropylene, having trimethoxysilyl groups at both ends of the main chain skeleton and having no urethane bond (viscosity 7,000 mPa at 25 ° C)・ S, Kaneka Co., Ltd. Silyl SAX530)
Copolymer of main chain skeleton of methyl methacrylate, n-butyl acrylate and butyl methacrylate (methyl methacrylate component content: 60% by weight, n-butyl acrylate component content: 20% by weight, butyl methacrylate component content (Meth) acrylate polymer (B1) (Alfon RA-100, manufactured by Toagosei Co., Ltd.), and having a trimethoxysilyl group at the side chain or terminal of the main chain skeleton. (Average molecular weight: 8,200, average number of trimethoxysilyl groups per molecule: 2.2)
Copolymer of main chain skeleton of methyl methacrylate, n-butyl acrylate and butyl methacrylate (methyl methacrylate component content: 60% by weight, n-butyl acrylate component content: 20% by weight, butyl methacrylate component content (Meth) acrylate polymer (B2) (RAE-505 manufactured by Toagosei Co., Ltd., weight average) having a trimethoxysilyl group at the side chain or terminal of the main chain skeleton. (Molecular weight: 8,500, average number of trimethoxysilyl groups per molecular weight: 1.3)
The main chain skeleton is a copolymer of methyl methacrylate and n-butyl acrylate (methyl methacrylate component content: 25% by weight, n-butyl acrylate component content: 75% by weight), and the side of the main chain skeleton (Meth) acrylate polymer (B3) having a trimethoxysilyl group at the chain or terminal (Alfon US-6110 manufactured by Toagosei Co., Ltd., weight average molecular weight: 3,200, trimethoxysilyl group per molecular weight Average number: 0.9)
The main chain skeleton is a copolymer of butyl methacrylate and methyl methacrylate (butyl methacrylate component content: 35% by weight, methyl methacrylate component content: 65% by weight), and at the side chain or terminal of the main chain skeleton (Meth) acrylate polymer (B4) having a trimethoxysilyl group (weight average molecular weight: 6,500, average number of trimethoxysilyl groups per molecular weight: 1.8)
Aminosilane coupling agent (1) (3-aminopropyltrimethoxysilane (KBM-903 manufactured by Shin-Etsu Chemical Co., Ltd.))
Aminosilane coupling agent (2) (N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (KBM-603, Shin-Etsu Chemical Co., Ltd.))
Hydrophobic silica surface-treated with dimethyldichlorosilane (average primary particle diameter 16 nm, BET specific surface area 110 m ² / g, AEROSIL R972 manufactured by Evonik Degussa)
・ Plasticizer (diisodecyl phthalate)
・ Dehydrating agent (vinyltrimethoxysilane (KBM-1003 manufactured by Shin-Etsu Chemical Co., Ltd.))
Hindered phenol antioxidant (1) (pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], melting point 118 ° C., IRGANOX (registered trademark) 1010 manufactured by BASF )
Benzotriazole-based UV absorber (1) (2- [5-chloro (2H) -benzotriazol-2-yl] -4-methyl-6- (tert-butyl) phenol, melting point 139 ° C., TINUVIN manufactured by BASF Corporation (Registered trademark) 326)
Benzotriazole ultraviolet absorber (2) (melting point: 10 ° C. or less, TINUVIN (registered trademark) 384-2 manufactured by BASF)
A mixture of hindered amine light stabilizer (bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate, melting point 10 ℃ or less, HS ester 765 manufactured by Toyokuni Oil Co., Ltd.)

  The initial tensile shear bond strength and the durable tensile shear bond strength of the curable composition with respect to the vinyl chloride plate or the AES plate were measured according to JIS A5536. The initial rubber strength and the durable rubber strength of the curable composition were measured as follows. The initial storage stability of the curable composition and the storage stability after standing for 7 days were measured as follows.

(Initial tensile shear bond strength)
Two vinyl chloride plates (width 25 mm, length 100 mm) were prepared, and the curable composition was applied to one end of each vinyl chloride plate in an application area of width 25 mm × length 25 mm. Next, these vinyl chloride plates were laminated so that the coating portions of the curable composition on each vinyl chloride plate overlapped to obtain a laminate. In the laminate, the lengths of the two vinyl chloride plates were parallel to each other, and the other end of each vinyl chloride plate was disposed at each of both ends in the length direction of the test piece. The curable composition was cured by allowing the laminate to stand in an atmosphere at a temperature of 23 ° C. and a relative humidity of 50% for 30 days, thereby obtaining a test piece. And the one end part of the length direction of each vinyl chloride board in this test piece is hold | gripped with a grip, is fixed to a tensile tester, and is pulled at a tensile speed of 50 mm / min, and thereby tensile shear adhesive strength (N / mm ² ) Was measured. Ten test pieces were prepared according to the same procedure, the tensile shear bond strength was measured for each test piece, and the arithmetic average value of these was used as the initial tensile shear bond strength of the curable composition. A result is shown in the column of "vinyl chloride board" of Tables 1-3.

  Further, the initial tensile shear bond strength of the curable composition was measured according to the same procedure as described above except that two AES plates were used instead of the two vinyl chloride plates. A result is shown in the column of "AES board" of Tables 1-3.

(Durable tensile shear bond strength)
Instead of curing the curable composition by leaving the laminate in an atmosphere of 23 ° C. and 50% relative humidity for 30 days, the laminate is left in an atmosphere of 23 ° C. and 50% relative humidity for 14 days. Further, after being left for 6 months in an atmosphere at a temperature of 60 ° C. and a relative humidity of 50%, the laminate is left to stand in an atmosphere at a temperature of 23 ° C. and a relative humidity of 50% for 1 day to cure the curable composition. The durable tensile shear bond strength of the curable composition was measured according to the same procedure as “Initial tensile shear bond strength” except that the test piece was obtained. The results are shown in the columns “Vinyl chloride plate” and “AES plate” of “Durable tensile shear adhesive strength” in Tables 1 to 3.

(Rubber hardness)
After the curable composition is applied to a lauan plywood having a thickness of 12 mm to a thickness of 10 mm, the curable composition is left to cure in an environment of 23 ° C. and a relative humidity of 50% for one month to be cured. I got a thing. The rubber hardness of the cured product was measured using a rubber hardness meter (Shore A). The obtained rubber hardness is shown in the column of “initial rubber hardness” in Tables 1 to 3.

  After the curable composition is applied to a lauan plywood having a thickness of 12 mm to a thickness of 10 mm, the curable composition is left to cure in an environment of 23 ° C. and a relative humidity of 50% for 1 month to be cured. Got. Further, the cured product was allowed to stand at 110 ° C. for 1 month, and then the cured product was allowed to stand for 24 hours in an environment of 23 ° C. and a relative humidity of 50%. The rubber hardness of the cured product was measured in the same manner as described above, and the obtained rubber hardness is shown in the column of “Durable rubber hardness” in Tables 1 to 3.

(Storage stability)
The curable composition was filled in a container and sealed, and left in an atmosphere at a temperature of 23 ° C. for 1 day. The viscosity (mPa · S) at 23 ° C. of the curable composition after standing was measured using a viscometer (B8U viscometer manufactured by Brookfield, rotor: No. 7, rotation speed: 10 rpm). The obtained viscosity is shown in the column of “initial storage stability” in Tables 1 to 3.

  The curable composition was filled in a container, sealed, and left in an atmosphere at a temperature of 60 ° C. for 7 days. The viscosity (mPa · S) at 23 ° C. of the curable composition after standing was measured in the same manner as described above. The obtained viscosity is shown in the column of “Storage stability after standing for 7 days” in Tables 1 to 3.

Claims (2)

100 parts by weight of a polyoxyalkylene polymer (A) having a trimethoxysilyl group and having a urethane bond in the main chain skeleton, and having a trimethoxysilyl group and the main chain skeleton being methyl (meth) acrylate, butyl It comprises a (meth) acrylate polymer (B) comprising a copolymer of monomers containing acrylate and butyl methacrylate, an aminosilane coupling agent, and 1 part by weight or less of a silanol condensation catalyst. A curable composition. A polyoxyalkylene polymer (A) having a trimethoxysilyl group and having a urethane bond in the main chain skeleton; and a main chain skeleton having a trimethoxysilyl group and having a main chain skeleton consisting of methyl (meth) acrylate, butyl acrylate, and a copolymer of monomers comprising butyl methacrylate (meth) acrylate-based polymer (B), and one containing an amino silane coupling agent, hardening you characterized by not containing a silanol condensation catalyst Sex composition.