JP5245541B2 - Curable composition for adhesive - Google Patents

Description

  The present invention relates to an adhesive composition that can be cured at room temperature, and more particularly to a curable composition for an elastic adhesive that has excellent weather resistance, little discoloration outdoors, and excellent workability.

A curable composition containing an organic polymer having a room-temperature curable reactive group is used as a sealing material or an adhesive for buildings. For example, a curable composition based on an oxyalkylene-based polymer having a hydrolyzable silyl group has good workability and is widely used as an adhesive for outer walls having a good balance of mechanical properties such as elongation at break and strength at break. It's being used.
In recent years, metal-based and ceramic-based outer wall materials such as tiles and panels have been frequently used, and an elastic adhesive capable of following the movement of the outer wall has been demanded.
In addition, since the adhesive itself may be exposed when joining tiles and panels, not only the adhesion to the outer wall material, but also the weather resistance and discoloration resistance that maintain performance over a long period of time are important. Various studies have been made.

  For example, in Japanese Patent Laid-Open No. 2001-329025, a polyether polymer (a) having at least one crosslinkable functional group that is incompatible with each other and a vinyl polymer (b) having at least one crosslinkable functional group. A method of adding a compatibilizing agent obtained by copolymerizing a plurality of vinyl monomers, which compatibilizes the component (a) and the component (b) to the above mixture is disclosed. However, the composition as described above has improved compatibility, but has a problem of insufficient weather resistance.

  Japanese Patent Application Laid-Open No. 2003-129036 discloses a sealing material composition comprising a copolymer containing an acrylic ester having a specific structure and a modified silicone polymer. However, the composition has insufficient workability when used as an adhesive, and there has been no description regarding performance as an adhesive.

  JP-A-2003-313419 is excellent in water-resistant adhesiveness containing a polyoxyalkylene polymer (a) having a silicon-based functional group and a polyoxyethylene chain-containing (meth) acrylic acid ester polymer (b). Curable compositions are disclosed. However, in order to produce a low molecular weight polymer (b), a large amount of chain transfer goods such as mercaptan is necessary, and the obtained polymer is difficult to use because of its strong odor, and is also resistant to discoloration and The weather resistance was also insufficient.

  Japanese Patent Application Laid-Open No. 2005-126671 discloses a vinyl polymer (a) containing a crosslinkable hydrolyzable silyl group and a polyether segment, and an organic polymer having a polyether segment and a number average molecular weight of 200 to 50,000. A curable composition containing a coalesced (b) is disclosed, and it is described that the additive is hard to be bleed-out after curing and has a viscosity that makes it easy to apply and fill. Yes. However, when the number average molecular weight of the organic polymer having a polyether segment is large, there is a problem that when used for an adhesive for an outer wall, the compatibility is lowered and weather resistance becomes insufficient, or discoloration occurs. there were.

JP 2001-329025 A JP 2003-129036 A JP 2003-313419 A JP 2005-126671 A

  An object of the present invention is to provide a curable composition for an elastic adhesive that can be cured at room temperature, with a good balance of mechanical properties such as elongation at break and strength at break, excellent weather resistance and discoloration resistance, and good workability. Is to provide.

  As a result of intensive studies in order to solve the above problems, the present inventors have determined that at least one of (poly) oxyalkylene glycol mono (meth) acrylate and (poly) oxyalkylene glycol monoalkyl ether mono (meth) acrylate. The present inventors have found that a curable composition containing a (meth) acrylic copolymer containing the above monomer and an oxyalkylene polymer having a hydrolyzable silyl group can satisfy the above performance, thereby completing the present invention.

That is, the present invention
[1] Component (A) Oxyalkylene polymer containing hydrolyzable silyl group, Component (B) (Poly) oxyalkylene glycol mono (meth) acrylate and (Poly) oxyalkylene glycol monoalkyl ether mono (meth) The number average molecular weight in terms of polystyrene by GPC obtained by copolymerizing at least one of the acrylate monomers (b1) at a ratio of 5 to 30 parts by weight and the other monomers at a ratio of 95 to 70 parts by weight. A (meth) acrylic copolymer that is less than 2000, and the weight ratio of the component (A) to the component (B) is 80 to 80 parts of the component (A) / (B) with respect to 100 parts by weight in total. It is 35 / 20-65, The curable composition for adhesive agents characterized by the above-mentioned.
[ 2 ] The other monomer of the component (B) is one or more (meth) acrylate monomers (b2) having an alkyl group having any one of 1 to 20 carbon atoms and may be branched. The curable composition for adhesives according to [1 ] .
[ 3 ] The oxyalkylene repeating unit contained in the (poly) oxyalkylene glycol mono (meth) acrylate and (poly) oxyalkylene glycol monoalkyl ether mono (meth) acrylate monomers of component (B) is 5 or more. The curable composition as described in [1] or [2] .
[ 4 ] The adhesive according to any one of [1] to [ 3 ], wherein the component (B) is obtained by continuous polymerization at a high temperature of 170 to 300 ° C. without using a mercaptan. Curable composition.
[ 5 ] In addition to one or more (meth) acrylates (b2) having other alkyl groups that may be branched, the functional group may be a functional group. (B3) may be included, and when the curable composition is 100 parts by weight, (b3) in the monomer of component (B) is 0 to 25 parts by weight [1] to [ 4 ] The curable composition for adhesives according to any one of [ 4 ].
[ 6 ] 20 to 300 parts by weight of filler as component (C) with respect to a total of 100 parts by weight of component (A) and component (B), the filler being heavy calcium carbonate and light calcium carbonate. The ratio (weight ratio) of heavy calcium carbonate / light calcium carbonate is 50/50 to 0/100, and the curability for an adhesive according to any one of [1] to [ 5 ] Composition.

  According to the present invention, it is possible to obtain a curable composition for an elastic adhesive having a good balance of mechanical properties such as elongation at break and strength at break, excellent weather resistance and discoloration resistance, and good workability.

  Hereinafter, the present invention will be described in detail. In addition, in this invention, (meth) acrylic acid ester or (meth) acrylate means acrylic acid ester and methacrylic acid ester.

Component (A) As the oxyalkylene polymer containing a hydrolyzable silyl group used in the present invention, what is generally called a modified silicone polymer is known, and a typical modified silicone polymer is known. Is a polymer having a structure having a hydrolyzable silyl group at the molecular end of polyoxyalkylene.
Examples of the polyoxyalkylene that becomes the skeleton of the polymer include polyoxyethylene, polyoxypropylene, and polyoxybutylene, and polyoxypropylene is preferable. The number average molecular weight of the polymer is preferably 1000 to 20000, more preferably 2000 to 15000. Moreover, the preferable glass transition temperature of this polymer is -100 degreeC-0 degreeC.
Commercially available products may be used as the polymer, and commercial products include trade name MS polymer and Silyl manufactured by Kaneka Corporation, or trade name Exstar manufactured by Asahi Glass Co., Ltd.

  Specifically, MS polymer S-203, S-303, S-801, etc. as trade name MS polymer, and silylyl SAT-200, SAT-350, SAT-400, SAT-010, SAT- Exstar ESS-3620, ESS-3430, ESS-3630, ESS-2420, ESS-2410, etc. are commercially available as trade name exesters such as 030 and ESX-250.

The (A) component of the present invention contains a (meth) acrylic group containing a hydrolyzable silyl group within a range that does not impair the adhesion and mechanical properties of the curable composition for the purpose of further improving the weather resistance. A copolymer (A ') component can be contained.
As a specific example of the component (A ′), a (meth) acrylic acid ester polymer having a polystyrene-equivalent number average molecular weight of 3,000 to 1,000,000 and having a hydrolyzable silyl group is preferable.
Such a (meth) acrylic acid ester polymer can be produced not only by ordinary radical solution polymerization but also by high-temperature continuous polymerization.
As polymerization conditions in the high-temperature continuous polymerization, the temperature is preferably 160 to 230 ° C.
It is preferable to employ high-temperature continuous polymerization from the viewpoint of obtaining stable quality without using a chain transfer agent such as mercaptan. As the high-temperature continuous polymerization method, JP-A-57-502171 and JP-A-59-6207 are preferred. And a known method disclosed in JP-A-60-215007.

  The proportion of the component (A ′) in 100 parts by weight of the component (A) is preferably 0 to 200 parts by weight, and when the component (A ′) is included, more preferably 10 to 150 parts by weight of (A ′). And 30 to 100 parts by weight is most preferred.

  In addition, the goods in which (A ') component was contained in (A) component are marketed, and this thing can also be used conveniently. Specific examples thereof include Silyl MA430, MA440, MA447, MA903, MA911, and MA943 manufactured by Kaneka Corporation.

Component (B) In the present invention, the component (B) includes at least one monomer (b1) of (poly) oxyalkylene glycol mono (meth) acrylate and (poly) oxyalkylene glycol monoalkyl ether mono (meth) acrylate. ), A (meth) acrylic copolymer obtained by copolymerizing the other monomer (b2).
The (poly) oxyalkylene glycol mono (meth) acrylate of (b1) is represented by the general formula [— (R—O) n—, wherein R represents an alkylene group having 1 to 4 carbon atoms. ] (Meth) acrylic acid ester having at least one polyalkylene oxide such as polyethylene oxide, polypropylene oxide, polybutylene oxide, etc. represented by polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (Meth) acrylate and polybutylene glycol mono (meth) acrylate are exemplified.
(Poly) propylene glycol mono (meth) acrylate is preferred because the adhesive of the present invention is excellent in workability and has good weather resistance.

Furthermore, poly (ethylene glycol-propylene glycol) mono (meth) acrylate, polyethylene glycol-polypropylene glycol mono (meth) acrylate, poly (ethylene glycol-tetramethylene glycol) mono (meth) acrylate, polyethylene glycol-polytetramethylene glycol mono (Meth) acrylate and the like can also be used.
Specific product names include Bremma-AP series, AEP series, PEP series, and PET series manufactured by NOF Corporation.

The other (b1) (poly) oxyalkylene glycol monoalkyl ether mono (meth) acrylate is represented by the general formula [-(RO) n-R1, wherein R has 1 to 4 carbon atoms. An alkylene group is shown. (Meth) acrylic acid ester having at least one polyalkylene oxide such as polyethylene oxide, polypropylene oxide, polybutylene oxide, and the like, specifically, polyethylene glycol monoalkyl ether mono (meth) acrylate, Examples thereof include polypropylene glycol monoalkyl ether mono (meth) acrylate and polybutylene glycol monoalkyl ether mono (meth) acrylate. Examples of the alkyl group (R1) of the alkyl ether include methyl, ethyl, propyl, butyl, and phenyl.
(Poly) oxyethylene glycol monomethyl ether mono (meth) acrylate is preferred in terms of weather resistance, workability, and discoloration resistance.
Specific examples of the product name include Bremma-PME series, AME series, and AEE series manufactured by NOF Corporation.

  Furthermore, n of the oxyalkylene repeating unit (general formula [-(RO) n-]) is 5 or more in order to improve various physical properties such as weather resistance, workability, tensile properties, and adhesive properties of the adhesive. It is preferable.

As the other monomer (b2) of the component (B), one or more (meth) acrylate monomers having an alkyl group having 1 to 20 carbon atoms and which may be branched are preferable. . The alkyl group may be cyclic.
Specific examples of such monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic acid. Isobutyl, secondary butyl (meth) acrylate, tertiary butyl (meth) acrylate, neopentyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, ( (Meth) acrylic acid alkyl esters such as (meth) acrylic acid tridecyl and (meth) acrylic acid stearyl; (meth) (meth) acrylic acid cyclohexyl, (meth) acrylic acid isobornyl and (meth) acrylic acid tricyclodecynyl Acrylic alicyclic alkyl ester; (meth) acrylic Chloroethyl, is (meth) (meth) halogenated alkyl esters of acrylic acid such as acrylic acid trifluoroethyl are exemplified.
From the viewpoint of workability when used as an adhesive, an alkyl group-containing (meth) acrylate having 1 to 8 carbon atoms is preferable, and methyl (meth) acrylate (also referred to as methyl (meth) acrylate in the present invention). 1 of butyl (meth) acrylate (also referred to as butyl (meth) acrylate in the present invention), 2-ethylhexyl (meth) acrylate (also referred to as 2-ethylhexyl (meth) acrylate in the present invention) More preferably, more than one species is used.

The ratio in the copolymerization of (b1) and (b2) is a ratio of 5 to 30 parts by weight of (b1) monomer and 95 to 70 parts by weight of (b2) monomer. When the amount of (b1) is too large, the water resistance is lowered, and when it is too small, the workability and the discoloration resistance are undesirably lowered.
The number average molecular weight in terms of polystyrene by gel permeation (GPC) of the copolymer is less than 2,000. If it is 2000 or more, the compatibility with the component (A) decreases, which is not preferable. The number average molecular weight is preferably 500 or more. If it is less than 500, it has a large amount of volatile components and causes odor and bleed out.

In the present invention, the weight ratio of the component (A) to the component (B) needs to be 80 to 35/20 to 65 for the component (A) / (B) with respect to 100 parts by weight of the total amount. When the component (A) is too much, the weather resistance is not improved, and when it is too little, the mechanical properties are insufficient. More preferably, (A) component / (B) component is 80-60 / 20-40.

The copolymer of the component (B) of the present invention may contain a monomer (b3) having a functional group in addition to the monomer (b2). Examples of the functional group of the monomer include a hydroxyl group, a hydrolyzable silyl group, an isocyanate group, an epoxy group, and a carboxylic acid group. From the viewpoint of curability, a hydroxyl group or a hydrolyzable silyl group is preferred.
Specific examples of the monomer having a hydroxyl group include hydroxyethyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxypropyl (meth) acrylate, and ε-caprolactone addition product of hydroxyethyl (meth) acrylate. Etc. are exemplified.
Specific examples of the monomer having a hydrolyzable silyl group include trimethoxysilylpropyl (meth) acrylate, triethoxysilylpropyl (meth) acrylate, methyldimethoxysilylpropyl (meth) acrylate, (meth) acrylic Examples thereof include methyldiethoxysilylpropyl acid.
The amount of the functional group-containing monomer (b3) used is an amount for substituting 0 to 25 parts by weight of the monomer (b2). In such a case, the amount of the functional group-containing monomer is used. The corresponding amount of the other monomer (b2) will be reduced.
That is, when the curable composition is 100 parts by weight, (b3) in the monomer of the component (B) is 0 to 25 parts by weight.

In addition, another monomer can be copolymerized with the monomer of (B) component in the range which does not drop the physical property of a curable composition. Examples of the monomer include α-olefins, vinyl esters, styrenes, vinyl ethers, and halogenated olefins.
In the production of the component (B) of the present invention, solution polymerization performed in an organic solvent, bulk polymerization performed in the absence of a solvent, suspension polymerization or emulsion polymerization performed in an aqueous medium can be used. Preferably, a mercaptan is used. Without producing it by continuous polymerization at a temperature of 170 to 300 ° C. More preferably, it is 200-280 degreeC, More preferably, it is 220-270 degreeC. A reaction temperature of less than 170 ° C. requires a large amount of initiator or organic solvent to obtain a copolymer having a polystyrene-reduced number average molecular weight of less than 2000 by GPC. This is not preferable because the properties are lowered. On the other hand, when the temperature is 300 ° C. or higher, the copolymer that can generate a decomposition reaction is colored, which is not preferable. The pressure depends on the reaction temperature, the monomer mixture to be used, and the boiling point of the solvent, and may be any pressure that does not affect the reaction but can maintain the reaction temperature. The residence time of the monomer mixture is preferably 1 to 60 minutes. If the residence time is less than 1 minute, the monomer may not sufficiently react, and if the residence time exceeds 60 minutes, productivity is lowered, which is not preferable. A more preferable residence time is 2 to 40 minutes.
In such a polymerization method, at the above temperature, it is not necessary to use a polymerization initiator, or even when a polymerization initiator is used, a copolymer having a desired molecular weight can be obtained with a small amount of use. A highly pure polymer containing almost no impurities as in the case of generating radical species is obtained. Further, since the molecular weight can be adjusted by adjusting the temperature, a chain transfer agent such as mercaptan is not required. For these reasons, the composition can be made more excellent in weather resistance. Further, since it is a continuous polymerization, there is no runaway polymerization, and it can be said to be a safe manufacturing method.

(C) component In this invention, 20-300 weight part of fillers are contained as (C) component with respect to a total of 100 weight part of (A) component and (B) component.
As the filler, heavy calcium carbonate and light calcium carbonate are preferable, and the weight ratio of heavy calcium carbonate / light calcium carbonate is 50/50 to 0/100.
The heavy calcium carbonate is calcium carbonate having an average particle size of about 1.0 to 5.0 μm, and the light calcium carbonate is calcium carbonate having an average particle size of about 0.02 to 2.0 μm. Specifically, those sold by Maruo Calcium Co., Ltd., Shiraishi Kogyo Co., Ltd., Shiraishi Calcium Co., Ltd., etc. may be used.

In order to adjust mechanical properties, the curable composition for adhesives of the present invention can contain other fillers in addition to calcium carbonate.
Specific examples include silica, silicic acids, diatomaceous earth, magnesium carbonate, carbon black, clay, talc, bentonite, titanium oxide, iron oxide, zinc oxide, zinc white, shirasu balloon, asbestos, glass fiber, and filament. The
For increasing the strength, silica, silicic acids, carbon black, clay, zinc white and the like are suitable. When importance is attached to elasticity, titanium oxide, magnesium carbonate, talc, ferric oxide, zinc oxide, and shirasu are preferred. A balloon or the like is preferred.

In order to control physical properties such as changing the hardness when the adhesive composition is cured, a physical property adjusting agent can be used. Examples of the physical property modifier include alkyl alkoxysilanes such as methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane and n-propyltrimethoxysilane; dimethyldiisopropenoxysilane, methyltriisopropenoxysilane and γ-glycol. Alkylisopropenoxysilanes such as Sidoxypropylmethyldiisopropenoxysilane; Various silane coupling agents such as vinyltrimethoxysilane, vinyltriethoxysilane, and vinylmethyldimethoxysilane; Silicone varnishes; Polysiloxanes are required Depending on the addition.
It is preferable to add in the range of 0-20 mass parts with respect to a total of 100 mass parts of (A) component and (B) component of this invention.

  Furthermore, in the present invention, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, N- ( β-aminoethyl) -γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and the like can be blended.

Moreover, an epoxy compound can be mix | blended for the improvement of adhesiveness or mechanical property.
Examples of such epoxy resins include epichlorohydrin-bisphenol A type epoxy resins, epichlorohydrin-bisphenol F type epoxy resins, flame retardant type epoxy resins such as glycidyl ether of tetrabromobisphenol A, novolac type epoxy resins, hydrogenated bisphenol A type epoxies. Resin, glycidyl ether type epoxy resin of bisphenol A propylene oxide adduct, p-oxybenzoic acid glycidyl ether ester type epoxy resin, m-aminophenol type epoxy resin, diaminodiphenylmethane type epoxy resin, urethane-modified epoxy resin, various alicyclic type Epoxy resin, N, N-diglycidylaniline, N, N-diglycidyl-o-toluidine, triglycidyl isocyanurate, polyalkylene glycol jig Examples include, but are not limited to, glycidyl ethers of polyhydric alcohols such as sidyl ether and glycerin, epoxidized unsaturated polymers such as hydantoin-type epoxy resins and petroleum resins, and glycidyl (meth) acrylate copolymers. The epoxy resin generally used can be used instead. Of these epoxy resins, those containing at least two epoxy groups in the molecule are particularly preferred because they are highly reactive during curing and the cured product easily forms a three-dimensional network. Among these, bisphenol A type epoxy resins or novolac type epoxy resins are more preferable.

Furthermore, a dehydrating agent can be added. Examples of dehydrating agents include orthoesters such as methyl orthoformate and methyl orthoacetate; compounds having hydrolyzable silyl groups such as tetraethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, and γ-methacryloxypropyltrimethoxysilane Etc.
It is preferable to add in 0-20 mass parts with respect to 100 mass parts of all the polymers of this invention.

In the adhesive curable composition of the present invention, a curing accelerator can be used in order to crosslink the hydrolyzable silyl group of the component (A). Examples of such curing accelerators include tin-based compounds such as dibutyltin dilaurate, dibutyltin bis (alkylmalate), dibutyltin dimethoxide, dibutyltin diphenoxide, dibutyltin diacetylacetonate, dibutyltin acetoacetate, dibutyltin oxide and ester compounds. And a reaction product of dibutyltin oxide and a silicate compound.
Examples of organic acid salts include tin octylate, tin oleate, tin stearate, and tin ferzatic acid.
In addition, organic carboxylic acids, organic sulfonic acids, and acidic phosphate esters can also be used.

  The adhesive curable composition of the present invention includes various solvents such as toluene and methyl ethyl ketone, surface property modifiers such as ultraviolet curable resins and oxygen curable resins, colorants such as pigments and dyes, and anti-aging agents. Additives such as UV absorbers, light stabilizers, flame retardants and the like may optionally be used.

  The adhesive composition of the present invention can be prepared as a one-pack type that cures by pre-blending and preserving all blending components and absorbing moisture in the air after construction. It is also possible to prepare as a two-component type of an adhesive hardener mainly composed of a copolymer and, if necessary, an epoxy resin, and a curing catalyst and optionally an epoxy resin hardener. .

  The present invention will be described below based on examples, but is not limited to the following examples.

<Synthesis Example 1>
The temperature of a 1000 ml capacity pressurized stirred tank reactor equipped with an oil jacket was kept at 200 ° C. Next, while keeping the pressure in the reactor constant, 85.0 parts by weight (hereinafter referred to simply as “parts”) of n-butyl acrylate (hereinafter referred to as BA), polypropylene glycol monomethacrylate (n = 5) A monomer mixture consisting of 15.0 parts, 10 parts of methyl ethyl ketone (hereinafter referred to as MEK) and 1.0 part of ditertiary butyl peroxide as a polymerization initiator, a constant feed rate (48 g / min, residence time) : 12 minutes), continuous supply from the raw material tank to the reactor was started, and a reaction solution corresponding to the supply amount of the monomer mixture was continuously withdrawn from the outlet. Immediately after the start of the reaction, once the reaction temperature decreased, an increase in temperature due to the heat of polymerization was observed. By controlling the oil jacket temperature, the reaction temperature was maintained at 248 to 252 ° C. and a pressure of 1.5 MPa.
The time when the temperature became stable from the start of the supply of the monomer mixture was taken as the reaction liquid collection start point, and the reaction was continued for 25 minutes. As a result, 1.2 kg of the monomer mixture was supplied, and 1.2 kg of reaction was started. The liquid was collected. Thereafter, the reaction solution was introduced into a thin film evaporator to separate volatile components such as unreacted monomers to obtain a concentrated solution. Tetrahydrofuran was used as a solvent, the polystyrene-equivalent number average molecular weight (hereinafter referred to as Mn) measured by gel permeation chromatography (hereinafter referred to as GPC) was 1270, and the weight average molecular weight (hereinafter referred to as Mw) was 2110. Met. The copolymers obtained by the reaction are collectively shown in Table 1 as “Polymer 1”.

<Synthesis Examples 2-9, 11-13>
A copolymer was synthesized by performing polymerization and treatment in the same manner as in Synthesis Example 1 except that the conditions shown in Table 1 were changed. The obtained polymers are referred to as “polymers 2 to 9, 11 to 13”, respectively. These results are shown in Table 1.
In Table 1, HEMA refers to 2-hydroxyethyl methacrylate, and HEA refers to 2-hydroxyethyl acrylate.

<Synthesis Example 10>
The monomer mixture was 57 parts of 2-ethylhexyl acrylate (hereinafter referred to as HA), 20 parts of methyl methacrylate (hereinafter referred to as MMA), 20 parts of polypropylene glycol monomethacrylate (n = 5), and γ-methacryloxypropyl. 3 parts of trimethoxysilane (hereinafter referred to as MSi), 10 parts of methyl orthoacetate (hereinafter referred to as MOA), 6.5 parts of methyl ethyl ketone (hereinafter referred to as MEK), and 1. 1 part of ditertiary hexyl peroxide as a polymerization initiator. A copolymer was synthesized by performing polymerization and treatment in the same manner as in Synthesis Example 1 except that the reaction temperature was changed to 0 part and the reaction temperature was 232 to 235 ° C. Mn was 1400 and Mw was 2510. The copolymer obtained by the reaction is referred to as “polymer 10”, and is shown in Table 1 together.

<Synthesis Example 14>
Into a 3 liter flask equipped with a dropping funnel, a nitrogen introduction tube, a thermometer, and a stirrer was charged 500 parts by weight of MEK as a solvent, and the temperature was raised to 80 ° C. while replacing with nitrogen. After confirming that the temperature became constant, 700 parts by weight of 2-ethylhexyl acrylate (hereinafter referred to as HA), 300 parts by weight of polypropylene glycol monomethacrylate (n = 5), 181 parts by weight of dodecyl mercaptan, 200 kg of MEK A mixture of both parts and 30 parts of azobisisobutyronitrile was added dropwise over 4 hours. Further, after stirring for 1 hour, the polymerization was stopped, and after MEK was distilled off, 1070 parts by weight of a liquid copolymer was obtained. Mn = 2300 and Mw = 3750. The copolymer obtained by the reaction is referred to as “polymer 14”.

<Synthesis Example 15>
The monomer mixture was 5 parts butyl methacrylate (hereinafter referred to as BMA), 5 parts methyl methacrylate (hereinafter referred to as MMA), 44 parts butyl acrylate (hereinafter referred to as BA), and 42.5 HA. Parts, 3.5 parts of γ-methacryloxypropyltrimethoxysilane (hereinafter referred to as MSi), 6 parts of isopropyl alcohol (hereinafter referred to as IPA), 4 parts of methyl orthoacetate (hereinafter referred to as MOA), methyl ethyl ketone (hereinafter referred to as MEK) Was changed to 8 parts, and ditertiary hexyl peroxide was changed to 0.1 part as a polymerization initiator, and the reaction temperature was 197 to 199 ° C. Mn of the obtained copolymer was 3600 and Mw was 11000. The number of hydrolyzable silyl groups per molecule of the polymer was 0.5. The copolymer obtained by the reaction is referred to as “polymer A”.

<Synthesis Example 16>
Into a 1 liter flask equipped with a dropping funnel, a nitrogen inlet tube, a thermometer, and a stirrer, 400 parts by weight of toluene and 3.0 parts by weight of mercaptopropylmethyldimethoxysilane (MDSi) were charged as solvents, and the temperature was changed to 90 ° C. while replacing with nitrogen. The temperature rose. After confirming that the temperature became constant, a mixture of 100.0 parts by weight of BA, 97.5 parts by weight of HA, 50.0 parts by weight of MMA, 2.5 parts by weight of MDSi, and azobisisobutyronitrile was dropped over 5 hours. did. After further stirring for 3 hours, the polymerization was stopped, and toluene was distilled off to obtain 224 parts by weight of a liquid copolymer. The composition of this copolymer was BA / HA / MMA / MDSi = 39/39/20/2, Mn = 3900, and Mw = 10200. The number of hydrolyzable silyl groups per molecule of the polymer was 0.5. The copolymer obtained by the reaction is referred to as “polymer B”.

<Examples 1-18, Comparative Examples 1-9>
The formulations of the examples are shown in Tables 2 and 3, and the formulations of the comparative examples are shown in Table 4. “Parts” in the table is “parts by weight”.
ES-S2420 (Asahi Glass Co., Ltd.) was used as the polyoxyalkylene polymer having a hydrolyzable silyl group.
The following evaluations were performed on these formulations. The evaluation results are shown in Tables 2 to 4 together with the formulation.

<Workability>
The workability (ease of application) when applying the adhesive composition was evaluated according to the following criteria.
・: Good, △: Somewhat bad, ×: Very bad <Adhesiveness>
A test piece was prepared based on JIS A5557 “Organic Adhesive for Exterior Tiling” and the adhesive strength was measured. Similarly, the fracture state was visually observed to determine the cohesive failure rate (%).
<Tensile test>
The above blend was applied at a thickness of 2 mm, and cured for one week under conditions of 23 ° C. and 50% RH to prepare a cured sheet. A dumbbell for tensile test (JIS K 6251 No. 3 type) was prepared from the obtained cured product, and the tensile strength (Tyolon 200, manufactured by Toyo Seiki Co., Ltd.) was used to determine the breaking strength (Ts in the table) and the breaking elongation (El in the table). ) Was measured.
<Weather resistance test>
The above blend was applied at a thickness of 0.4 mm, and cured for one week under conditions of 23 ° C. and 50% RH to prepare a cured sheet. An accelerated weather resistance test was performed with a metering weather meter (DAIPLA METAL WEATHER KU-R5NCI-A, manufactured by Daipura Wintes), the appearance change was observed, and the time when the abnormality occurred was recorded.
・: No change △: Shallow cracks occurred ×: Deep cracks reaching the base material <Discoloration resistance>
The above composition was applied to a mortar board at a thickness of 5 mm, and an exterior mosaic tile specified in JIS A 5209 was adhered thereto, followed by curing at 23 ° C. and 50% RH for 1 week to prepare a test piece. An exposure test was performed on an outdoor exposure table with an inclination angle of 45 degrees, and ΔE was determined from the exterior mosaic tile color tone before and after the test.

As is clear from the comparison between Examples and Comparative Examples, the adhesive composition of the present invention is excellent in workability and has a balance of sufficient adhesive strength, tensile (mechanical) physical properties, weather resistance, and discoloration resistance. A curable composition capable of curing at room temperature is obtained for the elastic adhesive.

Claims (6)

(A) Component An oxyalkylene polymer containing a hydrolyzable silyl group,
(B) Component 5-30 parts by weight of at least one monomer (b1) of (poly) oxyalkylene glycol mono (meth) acrylate and (poly) oxyalkylene glycol monoalkyl ether mono (meth) acrylate, other A (meth) acrylic copolymer having a polystyrene-reduced number average molecular weight of less than 2000, obtained by copolymerizing the monomer at a ratio of 95 to 70 parts by weight,
Contain,
The weight ratio of the component (A) to the component (B) is such that the (A) component / (B) component is 80 to 35/20 to 65 with respect to 100 parts by weight as a total amount . Composition. The other monomer of the component (B) is one or more (meth) acrylate monomers (b2) having an alkyl group which has any of 1 to 20 carbon atoms and may be branched. 1. The curable composition for adhesives according to 1. The oxyalkylene repeating unit contained in the monomer (B) component (poly) oxyalkylene glycol mono (meth) acrylate and (poly) oxyalkylene glycol monoalkyl ether mono (meth) acrylate is 5 or more. Or the curable composition of 2. The curable composition for an adhesive according to any one of claims 1 to 3 , wherein the component (B) is obtained by continuous polymerization at a high temperature of 170 to 300 ° C without using a mercaptan. . In addition to the one or more (meth) acrylates (b2) having other alkyl groups that may be branched, the other monomer of the component (B) has a functional group. may include mer (b3), the curable composition is 100 parts by weight, more of claims. 1 to 4 (B) in the monomer component (b3) is from 0 to 25 parts by weight The curable composition for adhesives as described in any one. 20 to 300 parts by weight of a filler as component (C) with respect to a total of 100 parts by weight of component (A) and component (B), the filler being heavy calcium carbonate and light calcium carbonate, The ratio (weight ratio) of fine calcium carbonate / light calcium carbonate is 50/50 to 0/100, and the curable composition for adhesives according to any one of claims 1 to 5 .