JP2005290273A - Curable composition, sealing material and adhesive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a moisture-curable composition which has elasticity and a shortened curing time, to provide a sealing material, and to provide an adhesive. <P>SOLUTION: This curable composition comprises (a) a vinylic polymer having cross-linkable silyl groups represented by formula (1): -[Si(R<SP>1</SP>)<SB>2-b</SB>(Y)<SB>b</SB>O]<SB>m</SB>-Si(R<SP>2</SP>)<SB>3-a</SB>(Y)<SB>a</SB>[R<SP>1</SP>and R<SP>2</SP>are each an alkyl, an aryl, an aralkyl, or the like; Y is OH or a hydrolyzable group; (a) is 0 to 3; (b) is 0 to 2; (m) is an integer of 0 to 19, where (a)+(m)(b)≥1], at the terminals, and having a number-average mol.wt. of 3,000 to 100,000 and a glass transition temperature of 20 to 150°C, and has a dynamic viscoelasticity (application frequency: 10 Hz, strain: 1%) storage elastic modulus characteristic E' of ≤105 Pa at temperature of 50 to 200°C and ≥106 Pa in a temperature region of ≤50°C. The curable composition can also be used as a hot melt adhesive or a sealing material. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a curable composition that is cured by moisture in an atmosphere, and more particularly, a moisture-curable curing composed of a vinyl polymer containing a crosslinkable hydrolyzable silyl group. The present invention relates to an adhesive composition, a sealing material and an adhesive using the curable composition.

  Conventionally, various curable compositions comprising a compound having a hydrolyzable silyl group such as an alkoxysilyl group and a crosslinking catalyst for curing the compound have been proposed (for example, Patent Documents 1 and 2 below). The above-mentioned crosslinking catalyst that hydrolyzes, dehydrates and condenses a silyl group of a compound having a hydrolyzable silyl group catalyzes a crosslinking reaction due to moisture in the air. As such a crosslinking catalyst, an organic metal catalyst such as an organic tin compound or an organic titanium compound, or an acid or a base is known.

  The cured product after moisture cross-linking of the compound having the hydrolyzable silyl group is rich in flexibility and has a joint that must absorb strain, a joint that receives a history of strain, impact resistance and creep resistance. Widely used in required joints. Further, the cured product is often used as a sealing material in a sealing portion that receives the same stress.

JP-A-56-67366 JP 57-155250 A

  Conventional curable compositions using a compound having a hydrolyzable silyl group are often in a liquid state, and therefore, in use, a relatively long time is required to obtain an appropriate bonding force that can be temporarily fixed. Sometimes this happened. Therefore, there has been a problem that it is difficult to apply the curable composition to an in-line production method with excellent productivity.

  The object of the present invention is not only in the light of the above-described state of the art, but can be cured by moisture in the atmosphere to give a cured product with excellent elasticity, as well as a bonding strength that can be temporarily fixed in use. It is an object of the present invention to provide a curable composition that can be used as a hot melt type adhesive or a sealing material, and a sealing material and an adhesive using the curable composition.

The curable composition according to the present invention has a crosslinkable silyl group represented by the formula (1) at the terminal, has a number average molecular weight of 3000 to 100,000, and a glass transition temperature in the range of 20 to 150 ° C. A curable composition comprising a polymer (a), which has a storage elastic modulus characteristic E ′ of 50 to 200 ° C. of dynamic viscoelasticity (applied frequency: 10 Hz, strain: 1%) of the curable composition. The curable composition has a temperature of 10 ⁵ Pa or lower at a temperature of 10 ⁶ Pa or higher in a temperature range of 50 ° C. or lower.
_{^{- [Si (R 1) 2}} -b (Y) b O] m -Si (R 2) 3-a (Y) a (1)
(In the formula, R ¹ and R ² are all alkyl groups having 1 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, or aralkyl groups having 7 to 20 carbon atoms, or (R ′) ₃ Si— ( R ′ represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, and three R ′ may be the same or different, and represents a triorganosiloxy group represented by R ¹ Alternatively, when two or more R ² are present, they may be the same or different, Y represents a hydroxyl group or a hydrolyzable group, and when two or more Y are present, they are the same. A may be 0 or 1, 2, or 3, and b may be 0, 1, or 2. m is an integer of 0 to 19, provided that a + mb ≧ 1 to be satisfied.)

  In another specific aspect of the curable composition according to the present invention, in addition to the vinyl polymer (a), a polyether polymer (c) having a crosslinkable hydrolyzable silyl group is further blended. The

  In still another specific aspect of the curable composition according to the present invention, a layered silicate is further blended.

The sealing material and the adhesive according to the present invention are both characterized by comprising a curable composition constituted according to the present invention.
Details of the present invention will be described below.

(Storage elastic modulus characteristic E ′ of dynamic viscoelasticity of curable composition)
In the curable composition according to the present invention, the storage elastic modulus characteristic E ′ of dynamic viscoelasticity (applied wave number 10 Hz, strain 1%) needs to be 10 ⁵ Pa or less at any temperature of 50 to 200 ° C. It is. If the storage elastic modulus characteristic E ′ exceeds 10 ⁵ Pa in this temperature range, the cohesive force is too high, the viscosity becomes remarkably high, and coating and coating may be difficult.

On the other hand, when the storage elastic modulus characteristic E ′ is 10 ⁵ Pa or less at a temperature of 50 ° C. or less, blocking may easily occur when the curable composition is stored, and handling may be difficult. Further, since the cohesive force is lowered, the initial adhesiveness is remarkably lowered. On the other hand, when the storage elastic modulus property E ′ is 10 ⁵ Pa or less at a temperature exceeding 200 ° C., the cohesive force and blocking property are excellent, but fluidity is not exhibited unless the temperature exceeds 200 ° C. Sex cannot be secured.

In the curable composition according to the present invention, in the temperature range of 50 ° C. or lower, the storage elastic modulus characteristic E ′ needs to be 10 ⁶ Pa or higher. If it is less than 10 ⁶ Pa, blocking tends to occur when the curable composition is stored, and handling becomes difficult. Further, the cohesive force is lowered, and the initial adhesiveness is remarkably lowered.

The vinyl polymer (a) having at least a crosslinkable silyl group used in the present invention is not particularly limited as long as the number average molecular weight is 3000 to 100,000 and the glass transition temperature is 25 to 150 ° C. Absent.
The curable composition of the present invention contains a vinyl polymer (a) having the terminal formula (1).
_{^{- [Si (R 3) 2}} -b (Y) b O] m -Si (R 4) 3-a (Y) a (1)
(In the formula, R ¹ and R ² are all alkyl groups having 1 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, or aralkyl groups having 7 to 20 carbon atoms, or (R ′) ₃ Si— ( R ′ represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, and three R ′ may be the same or different, and represents a triorganosiloxy group represented by R ¹ Alternatively, when two or more R ² are present, they may be the same or different, Y represents a hydroxyl group or a hydrolyzable group, and when two or more Y are present, they are the same. A may be 0 or 1, 2, or 3, and b may be 0, 1, or 2. m is an integer of 0 to 19, provided that a + mb ≧ 1 to be satisfied.)

  The hydrolyzable group represented by Y is not particularly limited, and examples thereof include an alkoxy group such as hydrogen, a halogen atom, a methoxy group, and an ethoxy group, an acyl oxide group, a ketoximate group, an amino group, an amide group, and an acid amide group. An aminooxy group, a mercapto group, an alkenyl oxide group and the like are preferable examples, and an alkoxy group that is easy to handle and does not generate harmful by-products during the reaction is particularly preferable. The hydroxyl group and hydrolyzable group can be bonded to one silicon atom in the range of 1 to 3, and the total number of hydroxyl groups and hydrolyzable groups in the formula (1), that is, a + mb is 1 to 1 A range of 5 is preferred. When two or more hydrolyzable groups or hydroxyl groups are bonded to the crosslinkable silicon group, they may be the same or different. The number of silicon atoms constituting the crosslinkable silicon compound may be one or two or more. In the case of silicon atoms linked by a siloxane bond, up to about 20 silicon atoms may be used.

  The vinyl polymer part constituting the vinyl polymer (a) may be a polymer obtained by polymerizing a vinyl monomer, such as polyethylene, polypropylene, polyisobutylene, poly (meth) acrylate, Examples include polystyrene, polyvinyl chloride, polyvinylidene chloride, polybutadiene, polyisoprene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, and polyvinyl ether. Moreover, the copolymer which has these vinyl polymer parts may be sufficient. A poly (meth) acrylate having a number average molecular weight of 10,000 or more and a copolymer thereof having a good balance between cohesive strength and adhesiveness are preferable. Here, (meth) acryl is an expression collectively showing methacryl and acryl.

Examples of the monomer for obtaining poly (meth) acrylate and its copolymer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, tert-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, glycidyl (meth) acrylate, tetrahydro Rufuryl (meth) acrylate, hexanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol di (Meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, epoxy acrylate, Polyester acrylate, urethane acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropy (Meth) acrylate, 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, pentaerythritol tri (meth) acrylate, 2-[(meth) acryloyloxy] ethyl 2-hydroxyethylphthalic acid, 2- [ (Meth) acryloyloxy] ethyl 2-hydroxypropylphthalic acid,
[Compound 1]
CH2 = CH-C (O) O-CH2CH2O-
[C (O) CH2CH2CH2CH2CH2O] n-H
(N = 1-10)
[Compound 2]
CH2 = C (CH3) -C (O) O-CH2CH2O-
[C (O) CH2CH2CH2CH2CH2O] n-H
(N = 1-10)
[Compound 3]
CH2 = CH-C (O) O- (CH2CH2O) n-H
(N = 1-12)
[Compound 4]
CH2 = C (CH3) -C (O) O- (CH2CH2O) n-H
(N = 1-12)
[Compound 5]
CH2 = CH-C (O) O- [CH2CH (CH3) O] n-H
(N = 1-12)
[Compound 6]
CH2 = C (CH3) -C (O) O- [CH2CH (CH3) O] n-H (n = 1-12)
[Compound 7]
CH2 = C (CH3) -C (O) O- (CH2CH2O) n-
[CH2CH (CH3) O] m-H
(M, n = 1-12)
[Compound 8]
CH2 = CH-C (O) O- (CH2CH2O) n-
[CH2CH (CH3) O] m-H
(M, n = 1-12)
[Compound 9]
CH2 = C (CH3) -C (O) O- (CH2CH2O) n-
(CH2CH2CH2CH2O) mH
(M, n = 1-12)
[Compound 10]
CH2 = CH-C (O) O- (CH2CH2O) n-
(CH2CH2CH2CH2O) mH
(M, n = 1-12)
[Compound 11]
CH2 = CH-C (O) O- (CH2CH2O) n-CH3
(N = 1-10)
[Compound 12]
CH2 = C (CH3) -C (O) O- (CH2CH2O) n-CH3
(N = 1-30)
[Compound 13]
CH2 = CH-C (O) O- [CH2CH (CH3) O] n-CH3
(N = 1-10)
[Compound 14]
CH2 = C (CH3) -C (O) O- [CH2CH (CH3) O] n-CH3
(N = 1-10)
[Compound 15]
CH2 = C (CH3) -C (O) O- (CH2CH2O) n-
[CH2CH (CH3) O] m-H
(M, n = 1-10)
[Compound 16]
CH2 = CH-C (O) O- (CH2CH2O) n-
[CH2CH (CH3) O] m-H
(M, n = 1-10)
[Compound 17]
CH2 = CH-C (O) O- [CH2CH (CH3) O] n
-C (O) -CH = CH2
(N = 1-20)
[Compound 18]
CH2 = C (CH3) -C (O) O- [CH2CH (CH3) O] n
-C (O) -C (CH3) = CH2
(N = 1-20)
[Compound 19]
CH2 = CH-C (O) O- (CH2CH2O) n-C (O) -CH = CH2
(N = 1-20)
[Compound 20]
CH2 = C (CH3) -C (O) O- (CH2CH2O) n
-C (O) -C (CH3) = CH2
(N = 1 to 20).

  Examples of other vinyl monomers include styrene such as styrene, indene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, p-chloromethylstyrene, p-methoxystyrene, p-tert-butoxystyrene, divinylbenzene, and the like. Derivatives; for example, compounds having vinyl ester groups such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl benzoate, vinyl cinnamate; maleic anhydride, N-vinylpyrrolidone, N-vinylmorpholine, (Meth) acrylonitrile, (meth) acrylamide, N-cyclohexylmaleimide, N-phenylmaleimide, N-laurylmaleimide, N-benzylmaleimide, n-propylvinylether, n-butylvinylether, isobutylvinylether, ter -Butyl 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, tritylene 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, glu Di (4-vinyloxy) butyl tartrate, di (4-vinyloxy) butyl trimethylolpropane trivinyl ether, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, 6-hydroxyhexyl vinyl ether, cyclohexane-1,4-di succinate Mention may be made of compounds having a vinyloxy group such as methanol-monovinyl ether, diethylene glycol monovinyl ether 3-aminopropyl vinyl ether, 2- (N, N-diethylamino) ethyl vinyl ether, urethane vinyl ether, polyester vinyl ether and the like.

The method for producing a vinyl polymer having a crosslinkable silyl group of formula (1) at the terminal is not particularly limited. For example, the above-described method is performed using an organic halide or a sulfonyl halide compound as an initiator and a transition metal complex as a catalyst. By polymerizing a vinyl monomer, a vinyl polymer having a terminal structure represented by formula (2) is produced, and the halogen of formula (2) is converted to a crosslinkable silyl group-containing substituent represented by formula (1). A method is mentioned.
-C (R ³ ) (R ⁴ ) (X) (2)
(In the formula, R ^3, R ⁴ represents a group bonded to an ethylenically unsaturated group of a vinyl monomer. In addition, X represents chlorine, bromine, or halogen atom iodine,.)
It is.

  The method for converting the halogen of the above formula (2) into the crosslinkable silyl group-containing substituent represented by the formula (1) is not particularly limited. For example, a compound having an alkenyl group and a crosslinkable silyl group, a silyl group, A method of reacting a compound having a stabilized carbanion, a compound having a polymerizable alkenyl group and another alkenyl group, an organometallic compound having an alkenyl group, a carboxylic acid metal salt having an alkenyl group, an alkenyl group and a stabilized carbanion For example, a method in which a halogen compound represented by formula (2) is substituted with an alkenyl group and then a hydrosilane having a crosslinkable silyl group is reacted with the alkenyl group.

In addition, when producing a vinyl polymer having a crosslinkable silyl group at the end of formula (1), an organic halide having a crosslinkable silyl group is used as an initiator, and a halogen is contained at one end. After synthesizing a polymer having a crosslinkable silyl group at one end, a polymer having a crosslinkable silyl group at both ends may be prepared by reacting with halogen and glycol, diamine, dicarboxylic acid, etc. After synthesizing a polymer having a halogen at one end and a crosslinkable silyl group at the other end,
Halogen may be converted to a crosslinkable silyl group by the above reaction. Alternatively, after synthesizing a polymer having a halogen at one end and a crosslinkable silyl group at the other end, the halogen may be converted to an alkenyl group by the above-described reaction, and then further converted to a crosslinkable silyl group. good.

Further, when producing a vinyl polymer having a terminal crosslinkable silyl group of formula (1),
After synthesizing a polymer having a halogen at one end and an alkenyl group at the other end using an organic halide having an alkenyl group as an initiator, the halogen is converted to an alkenyl group, And a method of converting to a crosslinkable silyl group by the above method.

  The number average molecular weight of the vinyl polymer (a) needs to be in the range of 3000 to 100,000 as described above. When it is less than 3000, the cohesive force is remarkably lowered and the initial adhesiveness is lowered. If it exceeds 100,000, the melt viscosity will remarkably increase or stringing will occur, making handling difficult.

  The glass transition temperature of the vinyl polymer (a) needs to be in the range of 25 to 150 ° C. When the temperature is lower than 25 ° C., blocking tends to occur when the curable composition is stored, and handling becomes difficult. Further, since the cohesive force is low, the initial adhesiveness is remarkably lowered. If the glass transition temperature exceeds 150 ° C, the cohesive force and blocking properties are excellent, but if the melting temperature is not heated close to the decomposition temperature of the resin, fluidity will not be exhibited, and thermal stability during heat melting cannot be secured. .

  In obtaining the vinyl polymer (a) having a glass transition temperature in the range of 25 to 150 ° C., the above-mentioned monomer for obtaining the vinyl polymer (a) preferably has a glass transition temperature of 25 to 25 ° C. Monomers that give a homopolymer at 150 ° C. are preferably used. Such monomers and glass transition points are as follows.

  tert-butyl acrylate (Tg = 41 ° C.), cetyl acrylate (Tg = 35 ° C.), isobornyl acrylate (Tg = 94 ° C.), phenyl acrylate (Tg = 57 ° C.), o-toluyl acrylate (Tg = 25 ° C.) , M-toluyl acrylate (Tg = 52 ° C.), p-toluyl acrylate (Tg = 43 ° C.), 2-naphthyl acrylate (Tg = 85 ° C.), 2-methoxycarbonylphenyl acrylate (Tg = 46 ° C.), 2-acryloyl Oxyethyl-2-hydroxypropyl phthalate (Tg = 68 ° C.), methyl methacrylate (Tg = 105 ° C.), ethyl methacrylate (Tg = 65 ° C.), sec-butyl methacrylate (Tg = 60 ° C.), isobutyl methacrylate (Tg = 48) ° C), propyl methacrylate (Tg = 35 ° C), isopropyl Tacrylate (Tg = 81 ° C.), n-stearyl methacrylate (Tg = 38 ° C.), cyclohexyl methacrylate (Tg = 66 ° C.), 4-tert-butylcyclohexyl methacrylate (Tg = 83 ° C.), tetrahydrofurfuryl methacrylate (Tg = 60) ° C.), benzyl methacrylate (Tg = 54 ° C.), phenethyl methacrylate (Tg = 26 ° C.), 2-hydroxyethyl methacrylate (Tg = 55 ° C.), 2-hydroxypropyl methacrylate (Tg = 26 ° C.), glycidyl methacrylate (Tg = 46 ° C), styrene (Tg = 100 ° C), p-methylstyrene (Tg = 101 ° C), p-chlorostyrene (Tg = 110 ° C)

(Polyether polymer (b))
In the curable composition concerning this invention, Preferably, the polyether polymer (b) which has a hydrolyzable silyl group which can be bridge | crosslinked is further mix | blended.

  Examples of the polyether polymer (b) include those in which the main chain consists essentially of a polyether polymer, and polymers in which the main chain consists of polyether and (meth) acrylic acid ester. By blending this polyether polymer, the water resistance of the cured product can be increased, and the rubber elasticity when a sealing material is formed can be increased. When the (meth) acrylic acid ester polymer and the polyether organic polymer are used in combination, the blending ratio of the polyether polymer (b) is 100 parts by weight of the vinyl polymer (a). ) Is preferably added at a ratio of 0.1 to 100 parts by weight, more preferably 0.5 to 100 parts by weight.

  When the blending ratio of the polyether polymer (b) is less than 0.1 parts by weight, the effect of improving the adhesiveness may be reduced, and when it exceeds 200 parts by weight, the weather resistance may be lowered and the adhesiveness may be decreased. The improvement effect may not be so high.

  The polyether polymer (b) essentially has a main chain of the general formula [— (R—O) n —, wherein R represents an alkylene group having 1 to 4 carbon atoms. ] A polymer containing a hydrolyzable silyl group which can be cross-linked at the terminal.

  The polyether polymer (b) is synthesized, for example, by reacting a polyalkylene oxide having an allyl group at the terminal with a hydrosilane compound represented by the following chemical formula (3) in the presence of a group VIII transition metal. .

Wherein R ⁵ is a group selected from a monovalent hydrocarbon group and a halogenated monovalent hydrocarbon group, a is an integer of 0, 1 or 2, X is a halogen atom, an alkoxy group, an acyloxy group, and Means an atom or group selected from a ketoximate group.)
Examples of the polyalkylene oxide that is the main chain of the polymer include polyethylene oxide, polypropylene oxide, polybutylene oxide, etc., but the cured product of the room temperature curable composition is excellent in water resistance and as a sealing material. Polypropylene oxide is preferable because it can ensure elasticity.

  As the crosslinkable hydrolyzable silyl group, those which do not generate harmful by-products after the reaction are preferable, and examples thereof include alkoxysilyl groups such as methoxysilyl group and ethoxysilyl group.

  If the number average molecular weight of the polyether polymer (b) is small, the elongation of the cured product is not sufficient, the followability to the joint surface is lowered, and if it is large, the viscosity before curing is increased, and the workability of the blending process is increased. Deteriorate. Therefore, the number average molecular weight is preferably 4,000 to 30,000, more preferably 10,000 to 30,000, and the molecular weight distribution is preferably 1.6 or less.

  Examples of the polyether polymer (b) include the trade name “MS polymer” (manufactured by Kaneka Chemical Industry Co., Ltd.), MS polymer S-203, S-303, etc. As Sakai Chemical Industry Co., Ltd.), Silyl SAT-200, SAT-350, SAT-400, and trade name "Exester" (manufactured by Asahi Glass Co., Ltd.), Exester ESS-3620, ESS-3430, ESS-2420, ESS -2410 and the like are commercially available.

(Layered silicate)
The layered silicate preferably used in the present invention means a silicate mineral having exchangeable cations between layers. The layered silicate used in the present invention is not particularly limited, and examples thereof include smectite clay minerals such as montmorillonite, saponite, hectorite, beidellite, stevensite, nontronite, vermiculite, halloysite, and swelling mica. It is done. Among these, montmorillonite and swellable mica are preferable. The layered silicate may be a natural product or a synthetic product, and one or more of these may be used.

  As the layered silicate, it is more preferable to use smectites or swelling mica having a large shape anisotropy effect defined by the following formula from the viewpoint of improving the mechanical strength and gas barrier property of the curable composition. In addition, the crystal | crystallization surface (A) and crystal | crystallization end surface (B) of layered silicate are typically shown in FIG.

Shape anisotropy effect = area of crystal surface (A) / area of crystal end face (B) As shown in FIG. 2, the exchangeable cation existing between the layers of the layered silicate is sodium on the crystal surface, These are ions such as calcium, and these ions have an ion exchange property with a cationic substance, so that various substances having a cationic property can be trapped (intercalated) between the layers of the layered silicate.

  Although it does not specifically limit as a cation exchange capacity | capacitance of the said layered silicate, It is preferable that it is 50-200 milliequivalent / 100g. If it is less than 50 milliequivalents / 100 g, the amount of the cationic surfactant that can be trapped (intercalated) between the crystal layers by ion exchange decreases, so the layers may not be sufficiently nonpolarized. On the other hand, when it exceeds 200 milliequivalents / 100 g, the bonding force between the layers of the layered silicate becomes strong, and it may be difficult to increase the distance between the crystal flakes constituting each layer of the layered silicate.

  The layered silicate is blended in an amount of 0.1 to 100 parts by weight with respect to 100 parts by weight of the base resin. More preferably, it is 0.5 to 50 parts by weight, and particularly preferably 1 to 10 parts by weight. When the amount is less than 0.1 part by weight, the effect of improving the weather resistance of the cured product and flame retardancy is hardly exhibited, and when the amount exceeds 10 parts by weight, the viscosity of the curable composition is increased and workability and productivity are reduced. There is.

In addition, the said base resin is the sum total of the said vinyl polymer (a) and the polyether polymer (b) added as needed.
The layered silicate preferably has an average interlayer distance of (001) plane measured by wide-angle X-ray diffraction measurement method of 3 nm or more and dispersed including those existing in 5 layers or less. When the average interlayer distance is 3 nm or more and the dispersion is 5 layers or less, it is advantageous for the weather resistance and flame retardancy performance of the curable composition.

  In the present specification, the average interlayer distance of the layered silicate is an average interlayer distance when the fine flaky crystal is used as a layer, and is obtained by X-ray diffraction peak and transmission electron microscope photography, that is, wide-angle X It can be calculated by a line diffraction measurement method. The state where the layers are cleaved to 3 nm or more and dispersed including those existing in 5 layers or less means that a part or all of the layered silicate laminate is dispersed, This is because the interaction between layers is weakened.

  Furthermore, when the average interlayer distance of the layered silicate is 6 nm or more, it is particularly advantageous for expressing functions such as flame retardancy, mechanical properties, and heat resistance. If the average interlaminar distance is 6 nm or more, the lamellar silicate crystal flake layers separate into layers, and the interaction of the lamellar silicate weakens so that it can be almost ignored. The dispersion state in progresses in the direction of delamination stabilization. That is, the layered silicate is present in a stabilized state in the curable composition in a state where the layered silicates are separated in a flake form one by one.

  As a dispersion state of the layered silicate, it is preferable that the flaky crystals of the layered silicate are highly dispersed in the base resin. More specifically, it is preferable that 10% by weight or more of the layered silicate is dispersed in a state where it is present in 5 layers or less, more preferably, 20% by weight or more of the layered silicate is 5 layers or less. It is desirable to exist in a state. Furthermore, if the number of laminated flaky crystals is 5 or less, the effect of the addition of the layered silicate can be obtained satisfactorily, but if it is 3 or less, it is more preferable, and it is dispersed in a single layer. More desirable.

  The layered silicate of the present invention is preferably a layered silicate treated with a quaternary ammonium salt. This is because the dispersibility of the layered silicate in the base resin can be improved by treating with a quaternary ammonium salt. Further, quaternary ammonium salts are known to have a catalytic action for the crosslinking reaction of the vinyl polymer, and disperse in the base resin together with the layered silicate to improve the dispersibility and accelerate the curing rate. It is also possible.

  Examples of the quaternary ammonium salt include lauryl trimethyl ammonium salt, stearyl trimethyl ammonium salt, trioctyl ammonium salt, distearyl dimethyl ammonium salt, di-cured tallow dimethyl ammonium salt, distearyl dibenzyl ammonium salt, and N-polyoxyethylene. -N-lauryl-N, N-dimethylammonium salt and the like can be mentioned, and these quaternary ammonium salts may be used alone or in combination of two or more. Among them, a quaternary alkyl ammonium ion salt having an alkyl chain having 6 or more carbon atoms or a polyoxyalkylene chain is preferable because good dispersibility can be obtained.

  Various stirrers can be used to disperse the layered silicate, but if it is difficult to disperse, it may be easy to obtain a desired dispersion state by dispersing using a high shearing device such as a three roll.

(Ultraviolet absorber and light stabilizer)
The curable composition of the present invention preferably contains various ultraviolet absorbers and light stabilizers in order to improve the weather resistance. This is because the layered silicate acts so as to suppress bleed-out of various ultraviolet absorbers and light stabilizers in combination with the layered silicate, so that these are retained in the cured product for a long time.

  Examples of the UV absorber include known UV absorbers such as benzotriazole and benzophenone, and among them, a benzotriazole UV absorber is preferable because of its high UV absorption performance. When the ultraviolet absorber is blended, it is preferably blended in an amount of 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the base resin. When the amount is less than 0.1 parts by weight, the effect of improving weather resistance may be insufficient. When the amount exceeds 20 parts by weight, problems such as deterioration of the appearance as a sealing material due to coloration occur.

  As the light stabilizer, for example, a hindered amine light stabilizer is used. A hindered amine light stabilizer generally exhibits an excellent effect when used in combination with an ultraviolet absorber. Among the hindered amine light stabilizers (hereinafter referred to as light stabilizers), those having a group having a structure represented by the following general formula (A) in the molecule are particularly effective when used in combination with a layered silicate. Examples of such a hindered amine light stabilizer include, for example, bis (2,2,6,6-tetramethyl-4-piperidine) sebacate, poly [{6- (1,1,3,3, -tetramethyl Butyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidine) imino} hexamethylene {(2,2,6,6-tetra Methyl-4-piperidine) imino}] and the like. These may be used alone or in combination of two or more.

  It is considered that the weather resistance effect by the combined use with the layered silicate is mainly due to the bleed-out prevention effect of the light stabilizer. That is, it is considered that the layered silicate interacts with the light stabilizer in the composition to prevent the light stabilizer from escaping from the system. In addition, it is considered that the bleedout of the light stabilizer is suppressed when the layered silicate acts like a plate that inhibits bleedout among the interactions. Among the light stabilizers, those having a group having the structure represented by the following general formula (A) in the molecule are considered to be particularly effective because the H atom bonded to the N atom is involved. .

  When the light stabilizer is blended, it is preferably blended in an amount of 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the base resin. If the amount is less than 0.1 part by weight, the effect of improving the weather resistance may be insufficient. If the amount exceeds 20 parts by weight, coloring problems may occur and the appearance as a sealing material may be impaired.

(Other additives)
In the curable composition of the present invention, unless the effect is hindered from the object of the present invention, a curing accelerator for the vinyl polymer (a), a viscosity modifier for adjusting the viscosity characteristics of the composition, a thixotropic agent, a tensile property Property modifiers, fillers, reinforcing agents, plasticizers, colorants, flame retardants, UV absorbers, light stabilizers, antioxidants, anti-sagging agents, anti-aging agents, solvents, fragrances, pigments, dyes Further, a dehydrating agent or the like may be added.

  As a hardening accelerator of a vinyl polymer (a), an organometallic compound part can be used, for example. As an organic metal compound that can be suitably used, an organic metal compound obtained by substituting a metal element such as germanium, tin, lead, boron, aluminum, gallium, indium, titanium, and zirconium with an organic group can be given. For example, dibutyltin dilaurate, dibutyltin oxide, dibutyltin diacetate, dibutyltin phthalate, bis (dibutyltin laurate) oxide, dibutyltin bisacetylacetonate, dibutyltin bis (monoester malate), tin octylate, dibutyl Tin compounds such as tin octoate and dioctyl tin oxide, titanate compounds such as tetra-n-butoxy titanate and tetraisopropoxy titanate, and these can be used alone or in combination of two or more.

  The viscosity modifier is selected, for example, from a polymer compound having good compatibility with the vinyl polymer (a), and is appropriately selected from compounds to be blended. For example, acrylic polymers, methacrylic polymers, polyvinyl alcohol derivatives, polyvinyl acetate, polystyrene derivatives, polyesters, polyethers, polyisobutene, polyolefins, polyalkylene oxides, polyurethanes, polyamides, natural rubber, polybutadiene , Polyisoprene, NBR, SBS, SIS, SEBS, hydrogenated NBR, hydrogenated SBS, hydrogenated SIS, hydrogenated SEBS, and the like. Moreover, these copolymers and functional group modified products can be mentioned, and these may be combined as appropriate.

  The thixotropic agent is appropriately selected from substances whose composition exhibits thixotropic properties. Examples thereof include colloidal silica, polyvinyl pyrrolidone, hydrophobized calcium carbonate, glass balloons, and glass beads. Regarding the selection of the thixotropic agent, it is desirable to have a surface having a high affinity for the vinyl polymer (a).

  Examples of physical property modifiers that improve tensile properties include various silane coupling agents such as vinyltrimethoxysilane, dimethyldimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, and phenyltrimethoxy. Silane, diphenyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- ( 2-aminoethyl) -3-aminopropyltriethoxysilane, N, N′-bis- [3- (trimethoxysilyl) propyl] ethylenediamine, N, N′-bis- [3- (triethoxysilyl) propyl] ethylene Amines, N, N′-bis- [3- (trimethoxysilyl) propyl] hexaethylenediamine, N, N′-bis- [3- (triethoxysilyl) propyl] hexaethylenediamine, and the like. Two or more types may be used in combination.

  As the extender, those which are added to the composition according to the present invention and do not exhibit thixotropic properties can be suitably used. For example, talc, clay, calcium carbonate, magnesium carbonate, anhydrous silicon, hydrous silicon, calcium silicate, Examples thereof include titanium dioxide and carbon black, and these may be used alone or in combination of two or more.

  Examples of the plasticizer include phosphate esters such as tributyl phosphate and tricresyl phosphate, phthalate esters such as dioctyl phthalate, fatty acid-basic acid esters such as glycerin monooleate, and dioctyl adipate. Examples thereof include fatty acid dibasic acid esters and polypropylene glycols, and these may be used alone or in combination of two or more.

(Adhesive and sealing material)
The curable composition according to the present invention is suitably used as a sealing material or an adhesive. As is clear from the examples described later, the curable composition according to the present invention is quickly cured by moisture in the atmosphere, gives a cured product having flexibility, and exhibits good adhesive strength. In addition, the curable composition according to the present invention can be quickly applied to the application part by heating and melting, and the time until temporary fixing can be shortened. Therefore, the curable composition according to the present invention can be suitably used as a hot-melt adhesive or sealing material.

In the curable composition according to the present invention, the vinyl polymer (a) having a crosslinkable silyl group has a molecular weight of 3000 to 100,000 and a glass transition temperature of 25 to 150 ° C. Since the storage elastic modulus characteristic E ′ is 10 ⁵ Pa or less at a temperature of 50 to 200 ° C. and 10 ⁶ Pa or more at a temperature of 50 ° C. or less, it has sufficient initial adhesiveness and heat resistant adhesiveness, and It is possible to provide a curable composition suitable as a hot-melt adhesive or a sealing agent that can shorten the time until temporary fixing. Therefore, the adhesive etc. which are used for the in-line production system excellent in productivity can be provided by using the curable composition concerning this invention.
In particular, the crosslinkable silyl group-containing vinyl polymer (a) of the present invention has a crosslinkable silyl group at the terminal as described above, so that it has a crosslinkable silyl group in the side chain. The cured product exhibits excellent elongation and elasticity despite its low viscosity before curing and easy handling with little stringing.

  Examples of the present invention and comparative examples will be described below. The present invention is not limited to the following examples.

(Example 1)
(Preparation of vinyl polymer (a1))
A 1 L three-necked round bottom flask equipped with a reflux tube was charged with cuprous bromide (6.25 g, 156 mmol), acetonitrile (50 mL), and pentamethyldiethylenetriamine (9.1 mL) and replaced with nitrogen gas. 180 g of isobornyl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd.), 45 g of styrene (manufactured by Wako Pure Chemical Industries, Ltd.), 135 g of cyclohexyl acrylate (manufactured by Osaka Organic Chemical Co., Ltd.), 90 g of n-butyl acrylate (manufactured by Wako Pure Chemical Industries, Ltd.), and diethyl- 2,5-Dibromoadipate (15.7 g, 43.6 mmol) was added, and the mixture was heated and stirred at 70 ° C. for 7 hours. The mixture was diluted with ethyl acetate and treated with activated alumina. Volatiles were distilled off under reduced pressure to obtain 350 g of a polyacrylic acid ester having a halogen at the terminal. The polymer had a Tg of 40 ° C., a number average molecular weight of 10700 as measured by GPC (polystyrene conversion), and a molecular weight distribution of 1.15.

Next, in a 2 L three-necked round bottom flask equipped with a reflux tube, poly (acrylic acid-n-butyl) having halogen at the terminal obtained as described above (350 g), potassium salt of 4-pentenoic acid ( 22.3 g, 161 mmol) and dimethylacetamide (350 mL) were charged and reacted at 70 ° C. for 4 hours in a nitrogen atmosphere. The mixture was diluted with ethyl acetate and washed with 2% hydrochloric acid, brine. The organic layer was dried over Na ₂ SO ₄ and the polymer was isolated by removing the volatiles under reduced pressure. An equivalent amount of aluminum silicate (manufactured by Kyowa Chemical Co., Ltd .: Kyowaard 700PEL) was added to the polymer and stirred at 100 ° C. for 4 hours to obtain poly (butyl acrylate) having an alkenyl group at the terminal. According to ¹ H-NMR analysis, 1.82 alkenyl groups were introduced per oligomer-1 molecule.

Next, the polymer (150 g), dimethoxymethylhydrosilane (18 mL, 145 mmol), dimethyl orthoformate (2.6 mL, 24.2 mmol), and a platinum catalyst were charged into a 200 mL pressure-resistant glass reaction vessel. However, the amount of platinum catalyst used was 2 × 10 ⁻⁴ equivalent in terms of molar ratio to the alkenyl group of the polymer. The reaction mixture was heated at 100 ° C. for 4 hours. The volatile component of the mixture was distilled off under reduced pressure to obtain poly (acrylic acid-n-butyl) having a silyl group at the terminal. According to ¹ H-NMR analysis, 1.46 silyl groups were introduced per oligomer-1 molecule.

(Preparation of curable composition)
100 g of the vinyl polymer (a1) obtained above, 3 g of dibutyltin dilaurate (manufactured by Wako Pure Chemical Industries, Ltd.) and 100 g of methyl acetate as a curing accelerator, and after mixing uniformly, the solvent is removed and the curable composition is removed. I got a thing.

When the storage elastic modulus characteristic E ′ was determined by dynamic viscoelasticity measurement of the curable composition obtained as described above, it was 4.89 × 10 ⁴ Pa or less at 120 ° C. and 2.50 × 50 ° C. It was 43 × 10 ⁶ Pa.

The above curable composition is melted at 150 ° C., applied to a 30 mm × 120 mm × 2 mm thick pentite steel plate to a thickness of 0.2 mm, and a slate plate of 30 mm × 120 mm × 8 mm thick is tensile-sheared on the coated surface. Bonding was performed so that the test was possible, and an adhesion test piece was obtained. The bonding area was 30 mm × 30 mm. The tensile shear adhesive force one minute after bonding was evaluated according to JIS K 6852 at a test speed of 5 mm / min. As a result, it was 0.51 N / mm ² . Moreover, when the tensile shear adhesive force 7 days after bonding was similarly evaluated, it was 0.57 N / mm ² . Also, the adhesion test piece 7 days after bonding was placed vertically in an oven, a load of 1000 g was applied to one adherend, and the temperature was raised from 30 ° C. at a rate of 1 ° C./min. No drop in load, that is, no peeling of the adhesive test piece could be confirmed even at a temperature of.

(Comparative Example 1)
In the synthesis of the vinyl polymer (a1), 90 g of isobornyl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd.), 45 g of styrene, 180 g of cyclohexyl acrylate (manufactured by Osaka Organic Chemical Co., Ltd.), 135 g of n-butyl acrylate (manufactured by Wako Pure Chemical Industries, Ltd.) A vinyl polymer (a2) was obtained in the same manner except that it was used. Tg of the vinyl polymer (a3) was 12 ° C., the number average molecular weight was 10700, as measured by GPC (polystyrene conversion), and the molecular weight distribution was 1.15.

It carried out similarly to Example 1 using the obtained vinyl polymer (2). The storage elastic modulus characteristic E ′ of the obtained curable composition was 8.10 × 10 ⁴ Pa or less at 100 ° C. and 8.40 × 10 ⁵ Pa at 50 ° C.
As a result of the adhesion test, the tensile shear adhesive force after 1 minute of bonding was 0.11 N / mm ² , and the shear adhesive force after 7 days of bonding was 0.49 N / mm ² . Moreover, about the adhesion test piece 7 days after bonding, when the temperature was increased by applying a load of 1000 g in the oven in the same manner as in Example 1, no drop in the load was observed even when the temperature reached 150 ° C. However, the adhesion region of the adhesion test piece was shifted by about 5 mm.

(Example 2)
In Example 1, during the preparation of the curable composition, 10 g of swellable fluoromica, organically treated with polyoxypropylene diethyl quaternary ammonium salt, manufactured by Co-op Chemical Co., Ltd., TINUVIN 770 (hindered amine) Curable composition in the same manner as in Example 1 except that 5 g of a light stabilizer, Ciba Specialty Chemicals) and 5 g of TINUVIN 327 (benzotriazole UV absorber, Ciba Specialty Chemicals) were added. Got.

(Measurement of average interlayer distance of layered silicate)
The average interlayer distance of the layered silicate in the curable composition obtained in Example 2 was measured as follows.

  Using a X-ray diffraction measurement device (RINT1100, manufactured by Rigaku Corporation), 2θ of the diffraction peak obtained by diffraction of the layered surface of the layered silicate is measured, and the (001) surface of the layered silicate using the following black diffraction equation The interval was calculated. The following d was defined as the average interlayer distance, and the average interlayer distance was well dispersed as 3 nm or more.

λ = 2 dsin θ
In the formula, λ (nm) = 0.154, d (nm) is the surface spacing of the layered silicate, and θ (degree) is the diffraction angle.

[Confirmation of dispersion state of layered silicate]
The dispersion state of the layered silicate in the cured product was observed with a transmission electron microscope (TEM, “JEM-1200EX II” manufactured by JEOL Ltd.), and was present in 5 layers or less.

Weather resistance evaluation [Evaluation]
The weather resistance of the curable compositions obtained in Examples 1 and 2 was evaluated by the following method. Each compounded composition was applied to a stainless steel plate of 50 mm × 150 mm (thickness 1 mm) at a thickness of 0.5 mm, allowed to stand for 7 days (168 hours) in an atmosphere of 20 ° C. × 60% RH, and then cured and cured. Irradiation with light was performed for 150 hours and 400 hours under the conditions, the surface state was visually confirmed, and those without cracks were determined as ◯.

Light irradiation condition Test apparatus: Eye super UV tester (SUV-F11 type), manufactured by Iwasaki Electric Co., Ltd. Irradiation intensity: 100 mW / cm ²
Limited wavelength: 295 nm to 450 nm
Black panel temperature: 63 ° C
Irradiation distance: 235mm (between light source and sample)
Although the light irradiation evaluation by the eye super UV tester varies depending on the material system and test conditions, it cannot be generally stated. However, it is usually 10 times more severe than the evaluation by the sunshine weatherometer. Has been. The results are shown in Table 1 below.

The schematic diagram for demonstrating the crystal | crystallization surface (A) and crystal | crystallization end surface (B) of the flaky crystal | crystallization of a layered silicate. The schematic diagram for demonstrating the exchangeable cation between the layers of layered silicate.

Claims (5)

It contains a vinyl polymer (a) having a crosslinkable silyl group represented by the formula (1) at the end, a number average molecular weight of 3000 to 100,000, and a glass transition temperature of 20 to 150 ° C. It is a curable composition, and the storage elastic modulus characteristic E ′ of the dynamic viscoelasticity (applied frequency: 10 Hz, strain: 1%) of the curable composition is 10 ⁵ Pa or less at any temperature of 50 to 200 ° C. In the temperature range of 50 ° C. or lower, the curable composition is 10 ⁶ Pa or higher.
_{^{- [Si (R 1) 2}} -b (Y) b O] m -Si (R 2) 3-a (Y) a (1)
(In the formula, R ¹ and R ² are all alkyl groups having 1 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, or aralkyl groups having 7 to 20 carbon atoms, or (R ′) ₃ Si— ( R ′ represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, and three R ′ may be the same or different, and represents a triorganosiloxy group represented by R ¹ Alternatively, when two or more R ² are present, they may be the same or different, Y represents a hydroxyl group or a hydrolyzable group, and when two or more Y are present, they are the same. A may be 0 or 1, 2, or 3, and b may be 0, 1, or 2. m is an integer of 0 to 19, provided that a + mb ≧ 1 to be satisfied.)   The curable composition according to claim 1, further comprising a polyether polymer (b) having a crosslinkable hydrolyzable silyl group.   The curable composition according to claim 1, further comprising a layered silicate.   A sealing material comprising the curable composition according to claim 1. An adhesive comprising the curable composition according to any one of claims 1 to 3.

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