JPH05287186A - Curable composition - Google Patents

Abstract

PURPOSE:To provide the curable composition excellent in weather resistance and useful for sealing materials, etc., which comprises a reactive silicon group- containing oxyalkylene polymer, a benzotriazole UV absorbent, and a hindered- phenol-based antioxidant as essential components. CONSTITUTION:(A) 100 pts.wt. of a reactive silicon group-containing oxyalkylenepolymer (e.g. gamma-glycidoxypropyltrimethoxysiliane-treated polyoxypropylene) is mixed with 120 pts.wt. of a fatty acid-treated colloidal calcium carbonate, 20 pts.wt. of titanium oxide, 50 pts.wt. of dioctylphthalate, 2 pts.wt. of stannous octylate and 0.5 pt.wt. of laurylamine. The mixture is mixed with (B) 1 pt.wt. of a benzotriazole UV absorbent [e.g. 2-(3,5-di-t-butyl-2- hydroxyphenyl)-5-chlorobenzotriazole] and (C) 1 pt.wt. of a hindered phenol-based antioxidant [e.g. 2,2'-methylenebis(4-methyl-6-t-butylphenol)] to give the curable composition.

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 provides a sealing material having excellent weather resistance.

[0002]

2. Description of the Related Art Sealing materials based on organic polymers containing a reactive silicon group are excellent in weather resistance and durability as modified silicone-based sealing materials, so that the demand is steadily expanding. Various synthetic methods have been proposed for organic polymers having at least one urethane bond at the same time as a reactive silicon group in the molecule, and interesting properties such as mechanical properties and water resistance of sealing materials have been found. However, due to the poor surface weather resistance caused by the contained urethane bonds, etc., it has not been put to practical use as a building sealing material where the same characteristics are important.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a sealing material which has a reactive silicon group-containing oxyalkylene polymer as a main component and has good weather resistance and excellent surface weather resistance. The inventors of the present invention have found that the combination of an ultraviolet absorber and an antioxidant exhibits a specific effect to obtain a sealing material having good weather resistance and excellent surface weather resistance, and has reached the present invention.

[0004]

Means for Solving the Problems The above-mentioned problems are (1) a reactive silicon group-containing oxyalkylene polymer having a number average molecular weight of 10,000 or more, (2) a benzotriazole type ultraviolet absorber and (3) a hindered phenol. This is achieved by a curable composition containing a system antioxidant as an essential component.

The reactive silicon group of the reactive silicon group-containing organic polymer that can be used in the present invention is not particularly limited, but representative ones are represented by the following general formula (1). And the groups mentioned above.

[0006]

[Chemical 1]

[Wherein R ¹ and R ² are each an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms,
Aralkyl group having 7 to 20 carbon atoms or (R ^{₃₎ 3} SiO-
When the number of R ¹ or R ² is 2 or more, they may be the same or different. Here, R ³ has 1 to 20 carbon atoms
Which is a monovalent hydrocarbon group, and the three R ^{3 s} may be the same or different. X represents a hydroxyl group or a hydrolyzable group, and when two or more X are present, they may be the same or different. a is 0, 1,
2 or 3, and b represents 0, 1, or 2.
In addition, b in the following m [Chemical Formula 2] groups may be different. m shows the integer of 0-19. However, a + Σb ≧
Satisfy 1. ]

[0008]

[Chemical 2]

The hydrolyzable group represented by X above is not particularly limited and may be any conventionally known hydrolyzable group. Specifically, for example, a hydrogen atom, a halogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an acid amide group, an aminooxy group, a mercapto group,
Examples thereof include an alkenyloxy group. Among these,
A hydrogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amido group, an aminooxy group, a mercapto group and an alkenyloxy group are preferable, but an alkoxy group such as a methoxy group is preferable from the viewpoint of mild hydrolyzability and easy handling. Particularly preferred.

1 to 3 of these hydrolyzable groups and hydroxyl groups can be bonded to one silicon atom, and (a + Σb) is 1
It is preferably -5. When two or more hydrolyzable groups or hydroxyl groups are present in the reactive silicon, they may be the same or different. The reactive silicon may have one silicon atom or two or more silicon atoms, but in the case of a reactive silicon group in which silicon atoms are linked by a siloxane bond or the like, there may be about 20 silicon atoms. Good.

The reactive silicon group represented by the following general formula (2) [Chemical Formula 3] is preferable from the viewpoint of easy availability.

[0012]

[Chemical 3]

[In the formula, R ² , X and a are the same as defined above. Specific examples of R ¹ and R ² in the general formula (1) include, for example, alkyl groups such as methyl group and ethyl group, cycloalkyl groups such as cyclohexyl group, aryl groups such as phenyl group, and benzyl group. Such as aralkyl group, R ³ is methyl group or phenyl group, etc. (R ³ ) ₃ S
Examples include a triorganosiloxy group represented by iO-. A methyl group is particularly preferable as R ¹ , R ² and R ³ .

At least one reactive silicon group is preferably present in one molecule of the oxyalkylene polymer, and preferably 1.1 to 5 is present. When the number of reactive silicon groups contained in one molecule of the polymer is less than 1, the curability becomes insufficient,
It becomes difficult to exhibit good rubber elasticity behavior. The reactive silicon group may be present at the terminal of the molecular chain of the oxyalkylene polymer or may be present inside thereof. When the reactive silicon group is present at the terminal of the molecular chain, the amount of effective network chains of the oxyalkylene polymer component contained in the finally formed cured product increases, so that high strength, high elongation, and low elastic modulus are achieved. The rubber-like cured product shown is easily obtained.

As the oxyalkylene polymer constituting the polymer chain in the polymer of the present invention, those represented by the following general formula (3) can be used. General formula (3)-(R-O) _n- : (R is a divalent alkylene group having 1 to 4 carbon atoms) However, from the viewpoint of easy availability, the repeating formula represented by the following general formula (4) is used. Oxyalkylene polymers having units are preferred.

General Formula (4) --CH (CH ₃ ) CH ₂ O-- The oxyalkylene polymer may be linear or branched, or may be a mixture thereof. Good. Further, other monomers and the like may be contained, but the monomer unit represented by the above general formula (4) is contained in the polymer in an amount of 50 or more.
It is preferably present in an amount of not less than 80% by weight, preferably not less than 80% by weight.

The oxyalkylene polymer having a reactive silicon group of the present invention is preferably obtained by introducing a reactive silicon group into an oxyalkylene polymer having a functional group. The reactive silicon group may be introduced by a known method. That is, for example, the following method can be used.

(1) An oxyalkylene polymer having a functional group such as a hydroxyl group at the terminal is reacted with an organic compound having an active group and an unsaturated group reactive with the functional group, or containing an unsaturated group. An unsaturated group-containing oxyalkylene polymer obtained by copolymerization with an epoxy compound is obtained. Then, the obtained reaction product is hydrosilylated by reacting hydrosilane having a reactive silicon group.

(2) The unsaturated group-containing oxyalkylene polymer obtained in the same manner as in the method (1) is reacted with a compound having a mercapto group and a reactive silicon group. (3) An oxypropylene polymer having a functional group such as a hydroxyl group, an epoxy group or an isocyanate group (hereinafter referred to as Y ¹ functional group) at the above-mentioned terminal has a functional group (hereinafter referred to as a functional group reactive with the Y ¹ functional group). , Y ² functional group) and a compound having a reactive silicon group.

Examples of the silicon compound having a Y ² functional group include γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane and γ-aminopropyltriethoxysilane. Amino group-containing silanes such as; γ-
Mercapto group-containing silanes such as mercaptopropyltrimethoxysilane and γ-mercaptopropylmethyldimethoxysilane; such as γ-glycidoxypropyltrimethoxysilane and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane Epoxy silanes; vinyl-type unsaturated group-containing silane groups such as vinyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-acryloyloxypropylmethyldimethoxysilane; γ-chloropropyltrimethoxysilane, etc. Chlorine atom-containing silanes;
γ-isocyanatopropyltriethoxysilane, γ-
Isocyanate-containing silanes such as isocyanate propylmethyldimethoxysilane; hydrosilanes such as methyldiethoxysilane can be specifically exemplified, but not limited thereto.

Among the above methods, the method (1) or the method (3) of reacting a polymer having a hydroxyl group at the terminal with a compound having an isocyanate group and a reactive silicon group is preferable. The reactive silicon group-containing polyoxyalkylene polymer is not particularly limited, but representative ones include, for example, JP-A-50-15.
6599, 54-6096, 57-12682.
No. 3, No. 59-78223, No. 55-82123,
55-131022, 55-137129, 62-230822, 63-83131, JP-A-3-47825, 3-72527, 3-122.
152, U.S. Pat. Nos. 3,632,557 and 4,3.
45,053, 4,366,307, 4,96
Examples thereof include those disclosed in No. 0,844.

In the present invention, when the oxyalkylene polymer as the component (1) contains a urethane bond (for example, when the isocyanate compound is used when introducing the crosslinkable silicon group), the effect of the present invention is obtained. Is achieved particularly markedly. Further, in the present invention, the number average molecular weight of the oxyalkylene polymer as the component (1) is 10,000 or more.
The effect of the present invention can be achieved remarkably even when it is 0 or more, particularly 15,000 or more.

When the above reactive silicon group-containing polymer is used as a curable composition, a curable catalyst, a filler, a plasticizer and various other additives can be used in combination, if necessary. Specific examples of the curable catalyst include titanic acid esters such as tetrabutyl titanate and tetrapropyl titanate; tin carboxylates such as dibutyltin dilaurate, dibutyltin maleate, dibutyltin acetate, tin octylate, tin naphthenate; dibutyltin oxide. Reaction products of phthalates with dibutyltin acetylacetonate; organoaluminum compounds such as aluminum trisacetylacetonate, aluminum trisethylacetoacetate, diisopropoxyaluminumethylacetoacetate; zirconium tetraacetylacetonate, titanium tetraacetylacetate Chelate compounds such as nato; lead octylate; butylamine, octylamine, dibutylamine,
Monoethanolamine, diethanolamine, triethanolamine, diethylenetriamine, triethylenetetramine, oleylamine, cyclohexylamine, benzylamine, diethylaminopropylamine, xylylenediamine, triethylenediamine, guanidine, diphenylguanidine, 2,4,6-tris (dimethylamino) Methyl) phenol, morpholine, N-methylmorpholine, 2-ethyl-4-methylimidazole, 1,8 diazabicyclo (5.4.0) undecene-7 (DBU), and other amine compounds, or carboxylic acids of these amine compounds Low molecular weight polyamide resin obtained from excess polyamine and polybasic acid; reaction product of excess polyamine and epoxy compound; γ-aminopropyltrimethoxysilane, N- (β-aminoe Le) a silane coupling agent having an amino group such as aminopropyl methyl dimethoxy silane; silanol condensation catalyst such as news other acidic catalysts, such as well-known silanol condensation catalysts such as basic catalyst. These catalysts may be used alone or in combination of two or more.

Examples of fillers include reinforcing fillers such as fumed silica, precipitated silica, silicic anhydride, hydrous silicic acid and carbon black; calcium carbonate, magnesium carbonate, diatomaceous earth, calcined clay, clay, talc, titanium oxide. Fillers such as bentonite, organic bentonite, ferric oxide, zinc oxide, activated zinc white, hydrogenated castor oil and silas balloons; fibrous fillers such as asbestos, glass fibers and filaments. Of course, these fillers may be used alone or in combination of two or more.

As the plasticizer, phthalic acid esters such as dioctyl phthalate, dibutyl phthalate and butylbenzyl phthalate; aliphatic dibasic acid esters such as dioctyl adipate, isodecyl succinate and dibutyl sebacate; diethylene glycol. Glycol esters such as dibenzoate and pentaerythritol ester; Aliphatic esters such as butyl oleate and methyl acetylricinoleate; Phosphate esters such as tricresyl phosphate, trioctyl phosphate, octyl diphenyl phosphate; epoxy Epoxy plasticizers such as epoxidized soybean oil, epoxidized linseed oil, and benzyl epoxy stearate; Polyester plasticizers such as polyesters of dibasic acid and dihydric alcohol; Polypropylene group Polyethers such as calls and derivatives thereof; poly -α- methyl styrene, polystyrenes such as polystyrene; polybutadiene, butadiene -
Plasticizers such as acrylonitrile copolymer, polychloroprene, polyisoprene, polybutene, and chlorinated paraffins may be optionally used alone or in the form of a mixture of two or more kinds.

As other additives, other curing catalysts (for example, laurylamine, lead octylate, etc.),
Adhesion improver, physical property adjuster, storage stability improver, ultraviolet absorber, metal deactivator, ozone deterioration inhibitor, light stabilizer, amine radical chain inhibitor, phosphorus peroxide decomposer, lubricant , Various additives such as pigments and foaming agents can be exemplified.

Specific examples of the benzotriazole type ultraviolet absorber that can be used in the present invention include Tinuvin P, Tinuvin 234, Tinuvin 320, Tinuvin 326, Tinuvin 327, Tinuvin 327 (all of which are manufactured by Nippon Ciba Geigy Co., Ltd.).
Can be exemplified, but especially Tinuvin 326, that is, 2-
(3,5-di-t-butyl-2-hydroxyphenyl)
-5-chlorobenzotriazole is preferred.

Specific examples of the hindered phenolic antioxidant usable in the present invention include Nocrac 200, Nocrac M-17, Nocrac SP, Nocrac SP-N, Nocrac NS-5, Nocrac NS-6, Nocrac NS -30, Nocrac 300, Nocrac NS-7, Nocrac DAH (all manufactured by Ouchi Shinko Chemical Industry Co., Ltd.); MARK AO-30, MARK
AO-40, MARK AO-50, MARK AO-60, MARK AO-616, AO-635, AO-
658, MARK AO-15, MARK AO-18, MARK 328, MARK AO-37 (all of them are manufactured by Adeka Argus Chemical Co., Ltd.); IRGANOX-2
45, IRGANOX-259, IRGANOX-565, IRGANOX-1010, IRGANOX-10
35, IRGANOX-1076, IRGANOX-1081, IRGANOX-1098, IRGANOX-
1222, IRGANOX-1330, IRGANOX-1425WL (all of which are manufactured by Ciba-Geigy Co., Ltd.) can be exemplified, but Nocrac NS-6, that is, 2,2'-methylenebis (4-methyl-6-t-butylphenol) is particularly preferable. .

By using a benzotriazole type ultraviolet absorber and a hindered phenol type antioxidant together,
It brings a specific improvement effect to the above polymer. The ultraviolet absorber and the antioxidant are used in an amount of 0.01 to 10 parts by weight, preferably 0.3 to 3 parts by weight, based on 100 parts by weight of the polymer.

[0030]

【Example】

(Examples 1 to 4) (Comparative Examples 1 to 5) (CH ₃ O) ₂ Si (CH ₃ ) CH ₂ was added to 85% of all terminals.
A polyoxypropylene polymer containing a CH ₂ CH ₂ — group and having a number average molecular weight of 18,000 as measured by gel permeation chromatography (polymer A) and the following [Chemical 4] group in the main chain skeleton. Containing an average of 2 (4 urethane bonds), and 90% of all terminals are (CH ₃ O) ₂ Si (CH ₃ )
CH ₂ CH ₂ CH ₂ NHC (O) O— groups were used, and two kinds of polymers, a polyoxypropylene polymer (polymer B) having a number average molecular weight of 18,000, were used. 120 parts by weight of fatty acid-treated colloidal calcium carbonate (average particle size 0.08μ), 20 parts by weight of titanium oxide, 50 parts by weight of dioctyl phthalate, and the additions described in [Table 1] and [Table 2] below. Required amount of agent, 2 parts by weight of tin octylate as a curing catalyst, 0.5 of laurinamine
1 part by weight is added, and the mixture is sufficiently kneaded and dispersed to prepare a curable composition, and a sheet having a thickness of 3 mm is prepared using the curable composition. After curing for 7 days, the sheets were exposed to a sunshine weatherometer and visually observed for the degree of deterioration of the sheet surface.

The molecular weight used was a high-performance gel permeation chromatograph HLC8020 manufactured by Tosoh Corporation, in which TSK gels G3000H and G4000H were connected in series as a column, THF as a solvent, and a measurement temperature of 40.0.
The measurement was carried out using a solution obtained by dissolving 0.05 g of a sample in 10 cc of THF as a sample solution at 1.0 ° C. at a measurement solvent flow rate of 1.0 ml / min.

[0032]

[Chemical 4]

The results are shown in the following [Table 1] and [Table 2].

[0034]

[Table 1]

[0035]

[Table 2]

[Table 1] and [Table 2] show that the combination of the benzotriazole type ultraviolet absorber and the hindered phenol type antioxidant improves the surface weather resistance specifically.

[0037]

EFFECT OF THE INVENTION Weatherability is improved by adding a benzotriazole-based UV absorber and a hindered phenol-based antioxidant together to a curable composition for a sealant based on a reactive silicon group-containing oxypropylene polymer. It is possible to provide a sealing material having good surface weather resistance.

Claims (1)

[Claims] 1. A curable composition containing (1) a reactive silicon group-containing oxyalkylene polymer, (2) a benzotriazole-based ultraviolet absorber, and (3) a hindered phenol-based antioxidant as essential components.