JPH08325466A - Improved curable composition - Google Patents

Abstract

PURPOSE: To prepare a curable compsn. which can provide a cured product having a surface possessing long-term crack resistance by incorporating a photocurable compd. having a photocurable unsatd. group and a urethane bond into an org. polymer having a reactive silyl group crosslinkable upon hydrolysis. CONSTITUTION: (A) An org. polymer contg. a reactive silyl group crosslinkable upon hydrolysis is mixed with (B) a photocurable compd. having a photocurable unsatd. group and a urethane bond to prepare a curable compsn. The component (A) is a polymer derived from polyether, polyester, or polycarbonate, and a polymer derived from a hydroxyl-contg. polyether is particularly pref. Pref., the component (B) has a photocurable unsatd. group, such as acryloyl, at its both ends having a relatively large chain length. In this curable compsn., the use of the component (B) in an amt. of 0.5 to 20 pts.wt. based on 100 pts.wt. of the component (A) is pref. If necessary, a photopolymerization initiator and other additives may be incorporated. This curable compsn., when used in a sealant for building, can inhibit creation of a surface crack and exhibits good stain resistance for a long period of time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a curable composition which is cured by moisture and is useful as a sealing material, a waterproof material and a coating material and has improved weather resistance. Specifically, it relates to a curable composition having excellent weather resistance, surface crack resistance, surface antifouling property, and coatability.

[0002]

2. Description of the Related Art Curable compositions obtained by blending various compounding agents with an organic polymer having one or more reactive silyl groups in the molecule are widely used as sealants, adhesives and the like.

[0003]

However, when this curable composition is used, for example, in a sealant for construction, there is a problem in long-term weather resistance depending on the composition conditions and construction conditions, and stickiness or cracks occur on the surface. Dirt such as dust adhered to the surface, which was a cause of impaired appearance.

For the purpose of solving this problem, Japanese Patent Publication No. 62-
26349, JP-A-57-190044, JP-A-3-2
94361 shows that a curable composition containing an organic polymer having a reactive silyl group and a photocurable compound having a (meth) acryloyl group is effective in reducing surface contamination. These methods include forming a film of a photocurable resin on the surface of the cured body by natural light after curing the curable composition by incorporating a photocurable compound having a functionality for light energy, and thus the weather resistance and the surface are improved. Based on the idea of improving pollution, both are
A method of adding an aliphatic ester oligomer having a polyfunctional acryloyl group is used.

However, as a result of the inventors' investigations on these methods, these polyfunctional acryloyl group-terminated ester oligomers have poor curability in air and a large number of crosslinking points, resulting in a brittle film to be formed. Tend to be
When used in applications that require flexibility and substrate followability, such as sealants, the surface layer part cannot follow the movement of the deep part, and rather it is not very effective in actual use such as generating deep cracks. found.

[0006]

[Means for Solving the Problems] The present inventors have investigated additives to be added to an organic polymer having a reactive silyl group for the purpose of improving long-term weather resistance, stain resistance and surface crack resistance. As a result, by using a compound having a photocurable unsaturated group and having one or more urethane bonds, weather resistance and stain resistance are excellent, and flexibility, curability, especially long-term crack resistance of the surface is improved. It has been found that an excellent cured product can be obtained.

The present invention is, namely, an organic polymer (A) having at least one reactive silyl group capable of being crosslinked by hydrolysis in the molecule, and at least one urethane having a photocurable unsaturated group. A curable composition containing a photocurable compound (B) having a bond.

[Organic Polymer] The organic polymer (A) having one or more reactive silyl groups capable of being crosslinked by hydrolysis in the present invention is an organic polymer selected from polyether, polyester and polycarbonate. And organic polymers derived from Further, a diene compound such as (meth) acrylic acid ester, vinyl alkyl ether, isobutylene, butadiene and chloroprene, a polymerizable monomer such as chlorotrifluoroethylene, tetrafluoroethylene, ethylene or propylene and a reactive silyl group-containing polymerizable monomer are used together. Examples include reactive silyl group-containing vinyl polymers obtained by polymerization.

Among the above-exemplified organic polymers, the one in which the effect of adding the photocurable compound (B) is particularly remarkable is an organic polymer which undergoes hydrolysis and a crosslinking reaction due to moisture to change into a rubber-like elastic body. is there. In particular, organic polymers derived from polyethers (hereinafter also referred to as reactive silyl group-containing polyethers) are liquid at room temperature, and the cured product retains flexibility even at relatively low temperatures, and is suitable for sealants, adhesives, etc. When utilized, it has desirable characteristics.

The polyether is obtained by subjecting an initiator containing active hydrogen to ring-opening polymerization reaction of alkylene oxide in the presence of a catalyst. Examples of the alkylene oxide include propylene oxide, ethylene oxide, butylene oxide, epichlorohydrin, styrene oxide and allyl glycidyl ether. Also, oxetane, tetrahydrofuran, etc. can be used.

As the initiator, polyhydric alcohols, polyhydric carboxylic acids, polyhydric active hydrogen compounds such as polyamines, terminal unsaturated group-containing monools, unsaturated phenols, unsaturated carboxylic acid-containing unsaturated group-containing compounds, etc. Examples include active hydrogen compounds.

As the catalyst, alkali metal compounds such as alkali metals such as sodium, potassium and cesium and hydroxides of these alkali metals, complex metal cyanide complexes,
Metal porphyrin complexes can be used.

It is particularly preferred that the reactive silyl group-containing polyether is derived from a hydroxyl group-containing polyether.

The reactive silyl group which can be cross-linked by hydrolysis (hereinafter also simply referred to as a reactive silyl group) is a silanol group or a hydrolyzable silyl group, which undergoes a condensation reaction with moisture or a curing catalyst to form an organic compound. It is capable of promoting the increase in molecular weight by crosslinking the polymer, and is preferably represented by the formula (1).

[0015]

[Chemical formula 1] -R ⁰ -SiX _a R ¹ _3-a (1)

In the formula, R ⁰ is a divalent organic group, R ¹ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, X is a hydroxyl group or a hydrolyzable group, and a is 1 to 3. Is an integer.

R ⁰ in the formula (1) is a divalent organic group.
R ¹ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, preferably an alkyl group having 8 or less carbon atoms,
It is a phenyl group or a fluoroalkyl group. Particularly preferred are methyl group, ethyl group, propyl group, butyl group, hexyl group, cyclohexyl group and phenyl group.

X in the formula (1) is a hydroxyl group or a hydrolyzable group, and the hydrolyzable group is, for example, a halogen atom, an alkoxy group, an acyloxy group, an amide group, an amino group, an aminooxy group, a ketoximate group or a hydride. There is a basis. Of these, the hydrolyzable group having a carbon atom preferably has 6 or less carbon atoms, and particularly preferably 4 or less carbon atoms. Preferred X is an alkoxy group having 4 or less carbon atoms, particularly a methoxy group, an ethoxy group or a propoxy group. 2 or 3 is preferable for a in Formula (1).

Examples of the method for producing the organic polymer (A) in the present invention include, but are not limited to, the following (a) to (f). In addition, (a) to (d)
It is an example of producing a reactive silyl group-containing polyether,
(E) to (f) are production examples of the vinyl polymer containing a reactive silyl group.

(A) A method of reacting an organosilicon compound having an isocyanate group and a reactive silyl group with a hydroxyl group-containing polyether.

As a concrete organosilicon compound,
The compound of

[0022]

Embedded image (C ₂ H ₅ O) ₃ Si (CH ₂ ) ₃ NCO (CH ₃ O) ₃ Si (CH ₂ ) ₃ NCO (CH ₃ O) ₂ (CH ₃ ) Si (CH ₂ ) ₃ NCO ( CH ₃ O) ₃ SiNCO (CH ₃ O) ₂ Si (NCO) ₂

(B) Formula HSiX _a R ¹ _3-a (wherein R ¹ ,
X and a are the same as the above), and a method of reacting a silicon hydride compound and a polyether having an unsaturated group introduced at the terminal.

Here, as a method of introducing an unsaturated group,
Method in which OH of hydroxyl group-containing polyether is changed to OM (M is an alkali metal) and then reacted with an unsaturated group-containing halogenated hydrocarbon such as allyl chloride, or a compound having an unsaturated group and a functional group capable of reacting with a hydroxyl group With a hydroxyl group-containing polyether to give an ester bond, a urethane bond,
There is a method of introducing an unsaturated group through a carbonate bond or the like. When polymerizing alkylene oxide in the production of a terminal hydroxyl group-containing polyether, a method of introducing an unsaturated group into a side chain by copolymerizing an unsaturated group-containing alkylene oxide such as allyl glycidyl ether, or a terminal as an initiator. There is also a method of introducing an unsaturated group at the terminal by using a hydroxyl group-containing polyether produced using an unsaturated group-containing monol.

(C) After the end of the hydroxyl group-containing polyether is reacted with a polyisocyanate such as tolylene diisocyanate to form an isocyanate group terminal, the isocyanate group is reacted with the W group of the silicon compound represented by the formula (2). Method.

[0026]

## STR3 ## _{^{W-R 2 -SiX a R 1}} 3-a ··· (2)

In the formula, R ¹ , X and a are as defined above, R ² is a divalent hydrocarbon group having 1 to 20 carbon atoms, W is a hydroxyl group, a carboxyl group, a mercapto group and an amino group. It is an active hydrogen-containing group selected from (primary or secondary).

(D) A method of reacting the unsaturated group of the polyether having an unsaturated group introduced at the terminal with the mercapto group of the silicon compound represented by the formula (2) in which W is a mercapto group.

(E) A method of copolymerizing a polymerizable monomer having a reactive silyl group or an oligomer thereof with another polymerizable monomer or an oligomer thereof.

The polymerizable monomer is, for example, the compound represented by the formula (3) alone or as a mixture of two or more kinds.

[0031]

[Chemical formula 4] CR ³ ₂ = CR ⁴ R ⁵ (3)

In the formula, R ³ is a hydrogen atom, a halogen atom or a monovalent hydrocarbon group, and R ⁴ and R ⁵ are monovalent organic groups. R ³ is preferably a hydrogen atom or a monovalent hydrocarbon group, R ⁴ and R ⁵ are a hydrogen atom, a halogen atom,
It is preferably a group selected from a monovalent hydrocarbon group, a phenyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, a glycidoxycarbonyl group, a nitrile group, an alkenyl group, an acyloxy group, an amide group and a pyridyl group.

Specific examples of the polymerizable monomer include styrene-based monomers such as styrene and α-methylstyrene, (meth) acrylic acid, their esters or (meth) acrylic monomers such as (meth) acrylamide, acrylonitrile, and 2 , 4-dicyanobutene-1 and other cyano group-containing monomers, vinyl acetate and other vinyl ester monomers, isoprene and butadiene and other diene monomers, isobutylene and other olefins and other unsaturated esters, halogenated olefins, vinyl ethers and the like. .

As the polymerizable monomer having a reactive silyl group, the compound represented by the formula (4) is used.

[0035]

[Chemical formula 5] Y _3-n -SiR ⁶ _n R ⁷ (4)

In the formula, R ⁶ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, Y is a hydroxyl group, a halogen atom, an alkoxy group, an acyloxy group, an amide group,
It is a hydrolyzable group such as an amino group, an aminoxy group, a ketoximate group, R ⁷ is an organic residue having a polymerizable unsaturated group, and n is an integer of 0 to 2.

Specific examples of the compound represented by the formula (4) include compounds represented by Chemical formula 6 and the like.

[0038]

Embedded image CH ₂ ═C (CH ₃ ) COO (CH ₂ ) ₃ Si
_{(CH 3) (OCH 3)} 2 CH 2 = C (CH 3) Si (CH 3) (OCH 3) 2

(F) A method of polymerizing a polymerizable monomer in the presence of a chain transfer agent containing a reactive silyl group.

Specific examples of the chain transfer agent containing a reactive silyl group include the compounds of Chemical formula 7 and the like.

[0041]

Embedded image HS (CH ₂ ) ₃ Si (OCH ₃ ) ₃ HS (CH ₂ ) ₃ Si (CH ₃ ) (OCH ₃ ) ₂

The organic polymer (A) of the present invention has a molecular weight of 50.
It is preferably from 00 to 50,000. When the molecular weight of the organic polymer (A) is less than 5000, the cured product becomes hard and has a low elongation. When the molecular weight exceeds 50,000, the flexibility and the elongation of the cured product are not a problem, but the organic polymer (A) The viscosity of itself becomes remarkably large, and its practicality becomes low. The molecular weight is particularly preferably 8000 to 30,000, more preferably 10,000 to 30,000.

[Photocurable compound (B)] In the present invention, the photocurable compound (B) having a photocurable unsaturated group and one or more urethane bonds (hereinafter referred to as a urethane bond-containing photocurable compound). (Also referred to as (B)).

The photo-curable unsaturated group means a group capable of undergoing a chemical change by the action of light. Examples of the photocurable unsaturated group include an acryloyl group, a methacryloyl group, a cinnamoyl group, and the acryloyl group is particularly preferable. Below, the acryloyl group and methacryloyl group (meth)
It is shown as an acryloyl group.

The photocurable compound (B) in the present invention is
A relatively long-chain polymer having a structure having photocurable unsaturated groups at both ends is preferable. Such a photocurable compound (B) can be synthesized by, for example, the following method, but is not limited thereto. (A) A method of reacting a hydroxyl group-containing compound having a photocurable unsaturated group, a polyvalent isocyanate, and a polyhydric alcohol. (B) A method of reacting a compound having an isocyanate group with a photocurable unsaturated group and a compound having a hydroxyl group.

In the case of synthesizing by the method (a), a polyhydric alcohol and a polyisocyanate are charged so that the molar ratio of isocyanate group / hydroxyl group is 1 or more, and reacted to obtain an isocyanate group-terminated prepolymer. It is obtained by charging the prepolymer and a hydroxyl group-containing compound having a photocurable unsaturated group so that the molar ratio of isocyanate group / hydroxyl group is about 1, and reacting.

Specific examples of the polyvalent isocyanate include 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate, tolidine diisocyanate and hexa. Methylene diisocyanate (HDI), isophorone diisocyanate, p-phenylene diisocyanate, transcyclohexane-1,4-diisocyanate, xylylene diisocyanate (XDI), hydrogenated XDI, hydrogenated MDI, lysine diisocyanate, tetramethylxylene diisocyanate, trimethylhexamethylene diisocyanate , Lysine ester triisocyanate, 1,6,11
-Undecane triisocyanate, 1,8-diisocyanate-4-isocyanatomethyl octane, 1,3
Examples thereof include 6-hexamethylene triisocyanate, bicycloheptane triisocyanate and the like, modified products of these isocyanates, and adduct compounds of these isocyanates with water, trimethylolpropane and the like. You may use 2 or more types of these polyvalent isocyanates.

As the polyhydric alcohol, ethylene glycol, 1,2-propylene glycol, trimethylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, Low-molecular compounds such as neopentyl glycol, 2,2,4-trimethyl-1,3-pentanediol, cyclohexanediol, dimethylolcyclohexane, and spiroglycol having a structure of chemical formula 8; polyethylene glycol, polypropylene glycol, alkylene of bisphenol A Oxide adducts, alkylene oxide adducts of the above low molecular weight compounds, polyether polyols such as polyoxytetramethylene glycol; polybutadiene diol, hydrogenated polybutadiene diol , An aliphatic polyol; a poly (epsilon) -caprolactone polyol, adipic acid, sebacic acid, phthalic acid, maleic acid, fumaric acid, azelaic acid, glutaric acid, and other polybasic acids; Examples thereof include a polyol having a terminal hydroxyl group such as a polycarbonate polyol of hexanediol. You may use 2 or more types of these polyhydric alcohols.

[0049]

Embedded image

Examples of the hydroxyl group-containing compound having a photocurable unsaturated group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl acrylate, trimethylene glycol mono (meth) acrylate and 1,4-butanediol mono (meth). ) Acrylate, 2-butene-
1,4-diol mono (meth) acrylate, 1,6-
(Meth) acrylates such as hexanediol mono (meth) acrylate, glycerol dimethacrylate, pentaerythritol triacrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate and the like can be mentioned.

On the other hand, in the case of synthesizing by the method (b), it can be obtained by directly reacting a compound having an isocyanate group, a photocurable unsaturated group and a hydroxyl group-containing compound. Examples of the compound having an isocyanate group and a photocurable unsaturated group include 2-isocyanate ethyl (meth) acrylate, methacryloyl isocyanate, 3- or 4-
Examples include isopropenyl-α, α-dimethylbenzyl isocyanate and the like.

Examples of the hydroxyl group-containing compound include the above polyhydric alcohols, hydroxyl group-terminated prepolymers, and oligomers having a hydroxyl group in the side chain. Among the above examples, those having a relatively high molecular weight are preferable as the polyhydric alcohol. The hydroxyl group-terminated prepolymer is obtained by charging the above polyhydric alcohol and the above polyvalent isocyanate so that the molar ratio of isocyanate group / hydroxyl group is less than 1, and reacting them. Oligomers having a hydroxyl group on the side chain are allyl alcohol, vinyl alcohol, hydroxyalkyl ether,
It is obtained by copolymerizing a hydroxyl group-containing polymerizable monomer such as hydroxyalkyl (meth) acrylate and a hydroxyl group-free polymerizable monomer.

The above photocurable compounds may be used alone or in combination of two or more. Further, the curable compound of the present invention may contain a photocurable compound containing no urethane bond (hereinafter, also referred to as a urethane bond-free photocurable compound) other than the photocurable compound (B).

Examples of such a urethane bond-free photocurable compound include propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, butylene glycol di (meth) acrylate, pentaerythritol tetra (meth) acrylate; Hydroxyl group-containing compounds having a photocurable unsaturated group, or unsaturated acrylic esters such as so-called oligoesters having a molecular weight of 10,000 or less, polycinnamic acid vinyls such as dicinnamoylhydroquinone, and azides obtained by polymerizing them. Chemical resin or the like is used.

The total amount of the photocurable compound used is preferably 0.1 to 40 parts by weight, more preferably 0.5 to 20 parts by weight, based on 100 parts by weight of the organic polymer (A). The amount of the urethane bond-containing photocurable compound (B) used in the total photocurable compound is preferably 50 to 100% by weight of the total photocurable compound.

If desired, a photopolymerization initiator may be added to the composition of the present invention. Examples of such a photopolymerization initiator include benzophenone, acetophenone, benzoin, and 2
-Chlorothioxanthone, benzyl, 2-ethylanthraquinone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one and the like can be mentioned.

In the curable composition of the present invention, in addition to the organic polymer (A), the photocurable compound (B) and the photopolymerization initiator added as necessary, a curing catalyst, a filler, a plasticizer,
Other additives and the like can be added as necessary.

[Curing Catalyst] In curing the curable composition of the present invention, a curing catalyst that accelerates the curing reaction of the reactive silyl group may be used. The following compounds may be mentioned as specific examples. One or more of them are used. The curing catalyst is preferably used in an amount of 0 to 10 parts by weight based on 100 parts by weight of the organic polymer (A).

Metal titanates, organosilicon titanates, metal salts such as bismuth tris (2-ethylhexoate), acidic compounds such as phosphoric acid, p-toluenesulfonic acid, phthalic acid, ethylenediamine, hexanediamine, etc. Aliphatic polyamines such as diamine triamine, triethylene tetramine, tetraethylene pentamine, heterocyclic amines such as piperidine and piperazine, aromatic amines such as m-phenylenediamine, ethanolamines, triethylamine, Amine compounds such as various modified amines used as curing agents for epoxy resins.

Tin dioctylate, dibutyl tin dilaurate (DBTDL), dioctyl tin dilaurate and
And a mixture of the carboxylic acid type organotin compound and the above amines.

A sulfur-containing organotin compound represented by Chemical formula 10.

Organotin oxides such as (nC ₄ H ₉ ) ₂ SnO and (nC ₈ H ₁₇ ) ₂ SnO, and these organotin oxides and ethyl silicates, dimethyl maleate, diethyl maleate, dioctyl maleate, phthalic acid Reaction products with ester compounds such as dimethyl, diethyl phthalate and dioctyl phthalate.

Chelating tin compounds such as Chemical formula 11 and the like, and reaction products of these tin compounds with alkoxysilane (where acac is an acetylacetonato ligand).

The tin compound of Chemical formula 12

[0065]

Embedded image (nC ₄ H ₉ ) ₂ Sn (OCOCH = CHCOOCH ₃ ) ₂ ; (nC ₄ H ₉ ) ₂ Sn
(OCOCH = CHCOOC ₄ H ₉ -n) ₂ ； (nC ₈ H ₁₇ ) ₂ Sn (OCOCH = CHCOOC
_{H 3) 2; (nC 8} H 17) 2 Sn (OCOCH = CHCOOC 4 H 9 -n) 2; (nC 8 H 17)
₂ Sn (OCOCH = CHCOOC ₈ H ₁₇ -iso) ₂ ;

[0066]

Embedded image (nC ₄ H ₉ ) ₂ Sn (SCH ₂ COO); (nC ₈ H ₁₇ ) ₂ Sn (SCH ₂ C
OO) ； (nC ₈ H ₁₇ ) ₂ Sn (SCH ₂ CH ₂ COO) ； (nC ₈ H ₁₇ ) ₂ Sn (SCH ₂ C
OOCH ₂ CH ₂ OCOCH ₂ S); (nC ₄ H ₉ ) ₂ Sn (SCH ₂ COOC ₈ H ₁₇ -iso) ₂ ;
(nC ₈ H ₁₇ ) ₂ Sn (SCH ₂ COOC ₈ H ₁₇ -iso) ₂ ; (nC ₈ H ₁₇ ) ₂ Sn (SCH
₂ COOC ₈ H ₁₇ -n) ₂ ; (nC ₄ H ₉ ) ₂ SnS;

[0067]

Embedded image (nC ₄ H ₉ ) ₂ Sn (acac) ₂ ; (nC ₈ H ₁₇ ) ₂ Sn (acac)
_{2; (nC 4 H 9)} 2 (C 8 H 17 O) Sn (acac);

[0068]

(NC ₄ H ₉ ) ₂ (CH ₃ COO) SnOSn (OCOCH ₃ ) (nC ₄ H ₉ )
₂ ; (nC ₄ H ₉ ) ₂ (CH ₃ O) SnOSn (OCH ₃ ) (nC ₄ H ₉ ) ₂ ;

[Filler] As the filler, known fillers can be used. The amount of the filler used is 100% of the organic polymer (A).
0 to 1000 parts by weight, especially 50 to 250 parts by weight
Parts by weight are preferred. Specific examples of the filler include the following. These fillers may be used alone,
You may use 2 or more types together.

Calcium carbonate, fumed silica, precipitated silica, silicic acid anhydride, hydrous silicic acid and carbon black, magnesium carbonate, diatomaceous earth, calcined clay, clay, talc, titanium oxide, bentonite, organic bentonite, ferric oxide, Powdered fillers such as zinc oxide, activated zinc oxide, shirasu balloon, wood flour, pulp, cotton chips, mica, walnut flour, rice flour, graphite, aluminum fine powder, flint powder, asbestos, glass fiber, glass filament, Fibrous fillers such as carbon fiber, Kevlar fiber and polyethylene fiber.

[Plasticizer] As the plasticizer, known plasticizers can be used. The amount of the plasticizer used is the organic polymer (A) 10
0 to 100 parts by weight is preferable with respect to 0 parts by weight. The following may be mentioned as specific examples of the plasticizer.

Dioctyl phthalate, dibutyl phthalate,
Phthalates such as butylbenzyl phthalate. Aliphatic carboxylic acid esters such as dioctyl adipate, diisodecyl succinate, dibutyl sebacate and butyl oleate. Alcohol esters such as pentaerythritol ester. Phosphate esters such as trioctyl phosphate and tricresyl phosphate. Epoxy plasticizers such as epoxidized soybean oil, dioctyl 4,5-epoxyhexahydrophthalate, and benzyl epoxystearate. Chlorinated paraffin. Polyester plasticizers such as polyesters of dibasic acids and dihydric alcohols, polyethers such as polyoxypropylene glycol and its derivatives, oligomers of polystyrene such as poly-α-methylstyrene and polystyrene, polybutadiene, butadiene- Polymer plasticizers such as acrylonitrile copolymer, oligomers such as polychloroprene, polyisoprene, polybutene, hydrogenated polybutene, and epoxidized polybutadiene.

[Adhesiveness imparting agent] An adhesiveness imparting agent is used for the purpose of further improving the adhesiveness. Examples of these adhesiveness-imparting agents include (meth) acryloxy group-containing silanes, amino group-containing silanes, mercapto group-containing silanes, epoxy group-containing silanes, and carboxyl group-containing silanes.

As the (meth) acryloxy group-containing silanes, γ-methacryloxypropyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, γ
-Methacryloxypropylmethyldimethoxysilane and the like.

As amino group-containing silanes, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane. Silane, N- (β-aminoethyl)-
γ-aminopropylmethyldimethoxysilane, N- (β
-Aminoethyl) -γ-aminopropyltriethoxysilane, γ-ureidopropyltriethoxysilane, N-
(N-vinylbenzyl-β-aminoethyl) -γ-aminopropyltrimethoxysilane, γ-anilinopropyltrimethoxysilane and the like.

As the mercapto group-containing silanes, γ-
Examples include mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, and γ-mercaptopropylmethyldiethoxysilane.

Examples of epoxy group-containing silanes include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane and γ-glycidoxypropyltriethoxysilane.

As the carboxyl group-containing silanes, β-
Carboxyethyltriethoxysilane, β-carboxyethylphenylbis (β-methoxyethoxy) silane,
N- (N-carboxylmethyl-β-aminoethyl)-
γ-aminopropyltrimethoxysilane and the like.

Further, a reaction product obtained by reacting two or more kinds of silane coupling agents may be used. Examples of the reaction product are reaction products of amino group-containing silanes and epoxy group-containing silanes, reaction products of amino group-containing silanes and (meth) acryloxy group-containing silanes, epoxy group-containing silanes and mercapto group-containing Examples thereof include reaction products of silanes and reaction products of silanes containing mercapto groups. These reactants are mixed with the silane coupling agent at room temperature to 150 ° C.
It is easily obtained by stirring in the temperature range of ° C for 1 to 8 hours.

The adhesion-imparting agents may be used alone or in combination of two or more. The amount of the adhesiveness-imparting agent used is 0 to 30 relative to 100 parts by weight of the organic polymer (A).
Parts by weight are preferred.

Other additives include storage stabilizers, hydrogenated castor oil, anti-sagging agents such as organic bentonites, surface modifiers such as air-curable compounds and photocurable compounds, phenol resins and epoxy resins. Known compounds such as tackifiers and pigments can be used.

In the present invention, the method for preparing the composition is not particularly limited. For example, the organic polymer (A) and the photocurable compound (B) are blended, and the mixture is mixed at room temperature or at room temperature with a mixer, roll, kneader or the like. A usual method such as kneading under heating or using a small amount of a suitable solvent to dissolve and mix the components may be employed. Further, by appropriately combining these components, a one-pack type or a two-pack type compound can be prepared and used.

[0083]

EXAMPLES Examples (Examples 1 to 8) and comparative examples (Examples 9 to 11) of the present invention will be given below, but the present invention is not limited thereto. The organic polymers P1 and P2 are the organic polymers used in the examples or comparative examples, and are the following propylene oxide polymers, respectively.

P1: A propylene oxide polymer having an average molecular weight of 17,000 and containing a dimethoxysilylpropyl group at 75% of all terminals. P2: A propylene oxide polymer having an average molecular weight of 30,000 and containing a dimethoxysilylpropyl group at 78% of all terminals.

The compounds A1 to A7 are shown in Table 1. The compounds A1 to A5 are photocurable compounds containing one or more urethane bonds in the molecule, and the compounds A6 to A7 are photocurable compounds containing no urethane bond.

[0086]

[Table 1]

(Synthesis Example 1: Synthesis of compound A4) Stirrer,
MDI (750 g), polycaprolactone diol of molecular weight 500 (1000 g), and DBTDL in a 3 L flask equipped with temperature controller, thermometer and condenser.
(53 mg) was added, and the mixture was heated at about 40 ° C. for 2 hours.
2-Hydroxyethyl acrylate (232 g) and hydroquinone monomethyl ether (198 mg) were added to the obtained reaction product. The reaction temperature was kept around 80 ° C. and the reaction was carried out for about 3 hours to obtain a resin composition.

(Synthesis Example 2: Synthesis of compound A5) Stirrer,
In a 3 L flask equipped with a temperature controller, thermometer and condenser, HDI (504 g), a polycarbonate diol with a molecular weight of 500 (1000 g) and DBTDL (45
mg) was added and the mixture was heated at about 40 ° C. for 3 hours. 2-Hydroxyethyl acrylate (232
g) and hydroquinone monomethyl ether (174 m
g) was added. The reaction temperature was kept around 80 ° C. and the reaction was carried out for about 3 hours to obtain a resin composition.

[Examples 1 to 11] Organic polymers (P1 to P2)
With respect to 100 parts by weight (hereinafter referred to as "parts"), the parts shown in the table of the photocurable compounds (A1 to A7) shown in Tables 2 and 3, 60 parts of white gloss CCR (calcium carbonate manufactured by Shiraishi Industry Co., Ltd.), Whiten SB (Shiraishi Kogyo Calcium Carbonate) 70 parts, Dioctyl Phthalate 60 parts, Epicoat 828 5.0 parts,
Titanium oxide 3.5 parts, Tinuvin 327 (Ciba Geigy benzotriazole UV absorber) 1.0 part, Sanol 765 (Sankyo Kasei Hindered amine light stabilizer)
0.5 parts of Irganox 245 (hindered phenolic antioxidant manufactured by Ciba-Geigy) and 4.0 parts of hydrogenated castor oil were added and mixed in a 2L d'alnetary mixer at 60 ° C. for 3 hours. After that, vacuum deaeration treatment was performed at 10 torr to obtain a composition.

3.0 parts of a curing catalyst prepared by mixing tin dioctylate and laurylamine in a weight ratio of 3/1 was added to the above composition and sufficiently kneaded to obtain a kneaded product.

This kneaded product was 50 mm long, 150 mm wide,
The mixture was placed in a mold having a thickness of 5 mm, formed into a sheet, and placed in a thermo-hygrostat at 20 ° C. and 65% humidity for 7 days to obtain two types of cured sheet. Table 2 shows the results of the following tests for each.
3 shows.

One of the cured sheets was set on a sunshine weatherometer (manufactured by Suga Test Instruments Co., Ltd.) and 750
The appearance of the surface after the lapse of time and after 1500 hours was visually observed (accelerated weathering test). The evaluations were: ⊚: no cracks were generated, ∘: microcracks were generated, Δ: deep cracks were generated, and x: cracks accompanied by surface softening were generated.

Furthermore, another one of the cured sheets is placed on the south side of the roof of the Tamagawa branch of Asahi Glass Co., Ltd. in Kawasaki City, Kanagawa Prefecture.
It was left at an angle of 1 degree, and the surface contamination after one year was visually observed (exposure test). The evaluation is: ◎: No cracks or dust adhered, ○: No cracks but dust adhered, △: Cracks and dust adhered, ×: Dust adhered severely I was told.

As shown in Examples 1 to 8, with the urethane bond-containing photocurable compound added, almost no cracks were observed in the accelerated weathering test. In the exposure test, no noticeable stains or cracks were found.

On the other hand, as shown in Example 9, in the system to which the photocurable compound was not added, surface softening and cracking occurred in the accelerated weathering test, and the contamination by exposure to light was severe.

Further, as shown in Examples 10 and 11, in the system to which only the urethane bond-free photocurable compound was added, cracks tended to be severe in both the accelerated weathering test and the exposure test.

[0097]

[Table 2]

[0098]

[Table 3]

[0099]

EFFECTS OF THE INVENTION The curable composition of the present invention is excellent in long-term durability of a cured product, especially in surface crack resistance and surface stain resistance.

Claims (2)

[Claims] 1. An organic polymer (A) having at least one reactive silyl group crosslinkable by hydrolysis in the molecule, and
A curable composition containing a photocurable compound (B) having a photocurable unsaturated group and having one or more urethane bonds. 2. The curable composition according to claim 1, wherein the photocurable unsaturated group is an acryloyl group.