JPH09316339A - Curable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a curable compsn. of a reactive silicon polymer excellent in viscosity, thixotropy and transparency by incorporating a specified fine silica powder into a specified oxyalkylene polymer. SOLUTION: This compsn. comprises (a) an oxyalkylene polymer containing at least one reactive silicon group in the molecule and (b) a fine silica powder surface-treated with an organopolysiloxane. The silica is one formed by flame hydrolisis of a silicon halide compd. and having a specific surface area of 20 to 400m<2> /g as determined by the nitrogen adsorption method. The organopolysiloxane is preferably one having a polymer chain of the formula (X is an alkyl group, hydroxyl group or alkoxyl group; R is an alkyl group, phenyl group, polyether group, polyether-substituted alkyl group or carbinol group; and n is an integer of 1 to 500.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a moisture-curable composition having excellent thixotropy.

[0002]

2. Description of the Related Art A polymer having a reactive silicon group is crosslinked and cured in the presence of moisture, and a curable composition using a polymer having a main chain skeleton of polyoxypropylene, for example, at room temperature It is liquid and has the property of becoming a rubber elastic body when cured, and is widely used in construction sealants, industrial sealants, elastic adhesives, and the like. An anti-sagging agent is used for the purpose of improving workability when applying the curable composition by filling the joints or coating the adherend. The anti-sagging agent improves workability by increasing the viscosity and thixotropy of the composition. As an anti-sagging agent, organic compounds such as polyamide wax and hydrogenated castor oil have been used so far, but it cannot be said that the dispersibility is high, the mixture is opaque, and the characteristics are exhibited unless heat treatment is performed. It is difficult and the viscosity is unstable. On the other hand, the inorganic surface silanol group hydrophilic fine powder silica produced by the dry method has a feature that a transparent composition can be easily obtained by mixing at room temperature, but the composition considered to be due to the reactivity of the surface silanol group Viscosity becomes unstable.
In addition, there is a problem that the thickening and thixotropic properties are small when using hydrophobic fine powder silica whose surface is treated with a silane compound (silylating agent) such as hexamethylsilazane or dimethyldichlorosilane to make it hydrophobic. It was

[0003]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention The invention of the present application is a solution to these problems, and is excellent in viscosity and thixotropy and is excellent in transparency. The curability of an oxyalkylene polymer containing a reactive silicon group is excellent. It is intended to provide a composition.

[0004]

Means for Solving the Problems The inventors of the present application have made extensive studies to solve the above problems, and as a result, have found that the above problems can be solved by using an organopolysiloxane surface-treated silica fine powder as a thixotropic agent. They found out and completed the invention of this application. That is, the invention of the present application relates to a curable composition containing (a) an oxyalkylene polymer containing at least one reactive silicon group in one molecule, and (b) an organopolysiloxane surface-treated silica fine powder. .

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The main chain skeleton of an oxyalkylene polymer having at least one reactive silicon group in one molecule (a) used in the present invention is essentially represented by the general formula (1). It has the repeating unit shown. —R ¹ —O— (1) (In the formula, R ¹ is a divalent alkylene group)

R ¹ in the general formula (1) has 1 to 1 carbon atoms.
Fourteen, even two to four, linear or branched alkylene groups are preferred. Specific examples of the repeating unit represented by the general formula _{(1), -CH 2 O -} , - CH 2 CH 2 O -, - CH 2 CH (C
_{H 3) O -, - CH} 2 CH (C 2 H 5) O -, - CH 2 C
_{(CH 3) 2 O -,} - CH 2 CH 2 CH 2 CH 2 O- and the like.

The main chain skeleton of the oxyalkylene polymer is 1
It may be composed of only types of repeating units, or may be composed of two or more types of repeating units. In particular, it is preferably composed of a polymer containing propylene oxide as a main component. Further, the polymer main chain may contain a repeating unit other than an alkylene group. In this case, the total sum of oxyalkylene units in the polymer is preferably 80% by weight or more, and particularly preferably 90% by weight or more.

The reactive silicon group contained in the component (a) is a group which has a hydroxyl group or a hydrolyzable group bonded to a silicon atom and can be crosslinked by forming a siloxane bond.

As a typical example, the general formula (2)-(SiR ² _2-a X _a O) _p -SiR ³ _3-b X _b (2) (wherein R ² and R ³ are both carbon C1-C20 alkyl group, C6-C20 aryl group, C7-C2
0 aralkyl group or R ⁴ SiO— (R ⁴ is 1 to 1 carbon atoms
20 is a monovalent hydrocarbon group, and three R ^{4 s} may be the same or different), and a triorganosiloxy group represented by the formula (2) and two or more R ² or R ³ are present. When they do, they may be the same or different. X represents a hydroxyl group or a hydrolyzable group, and when two or more Xs are present, they may be the same or different. a is 0, 1, or 2, b is 0, 1, or
2 or 3 is shown, respectively. In addition, p in the group represented by the general formula (3) and a in —SiR ² _2-a X _a O— (3) may be the same or different. p shows the integer of 0-19. However, (sum of a) + b
It is assumed that ≧ 1 is satisfied. And a group represented by).

The hydrolyzable group represented by X above is
There is no particular limitation, and any conventionally known hydrolyzable group may be used. Specific examples include 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 and 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, and an alkoxy group is particularly preferable from the viewpoint of mild hydrolyzability and easy handling.

The hydrolyzable group or hydroxyl group can be bonded to one silicon atom in the range of 1 to 3, and (sum of a) + b is preferably in the range of 1 to 5. When two or more hydrolyzable groups or hydroxyl groups are bonded to the reactive silicon group,
They may be the same or different.

The number of silicon atoms forming the reactive silicon group may be one or two or more, but in the case of silicon atoms linked by a siloxane bond or the like, 20
There may be about one. In general formula ^{_{(4) -SiR 3 3-b}} X b (4) ( wherein, R ^3, X, b are as defined above) is a reactive silicon group represented by, from the viewpoint is easily available .

Specific examples of R ² and R ^{3 in} the above general formulas (3) and (4) include, for example, a methyl group,
Alkyl groups such as ethyl group, cycloalkyl groups such as cyclohexyl group, aryl groups such as a phenyl group, or an aralkyl group such as a benzyl group, R ⁴ R ⁴ is an aryl group such as an alkyl group, a phenyl group such as a methyl group ₃ SiO
A triorganosiloxy group and the like.
R ² and R ³ are methyl groups, R ⁴ is a methyl group,
Phenyl is particularly preferred.

The reactive silicon group may be introduced by a known method. That is, for example, the following method is used. (A) An oxyalkylene polymer having a functional group such as a hydroxyl group in a molecule is reacted with an organic compound having an active group and an unsaturated group reactive with the functional group to form an oxyalkylene group containing an unsaturated group. An alkylene polymer is obtained. Alternatively, an unsaturated group-containing oxyalkylene polymer is obtained by copolymerization with an unsaturated group-containing epoxy compound. Then, the obtained reaction product is reacted with a compound having a group capable of reacting with an unsaturated group and reactive silicon. Examples of the compound having a group capable of reacting with an unsaturated group and a reactive silicon group include hydrosilane having a reactive silicon group and a mercapto compound having a reactive silicon group. (B) An oxyalkylene polymer having a functional group such as a hydroxyl group, an epoxy group or an isocyanate group in the molecule is reacted with a compound having a functional group reactive with this functional group and a reactive silicon group. Among the above methods,
Among the method (a) or the method (b), a method 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 polymer as the component (a) may be a linear polymer or a branched polymer, and its molecular weight is from 500 to 500.
About 50,000, more preferably 1,000 to 30,
000. At least one reactive silicon group is preferably present in one molecule of the polymer, and preferably 1.1 to 5 reactive silicon groups are present. The number of reactive silicon groups contained in the molecule is 1
If it is less than the number, the curability will be insufficient, and if it is too large, the network structure will be too dense and good mechanical properties will not be exhibited.

Specific examples of the component (a) include JP-B-45.
No. 36319, No. 46-12154, JP-A-50-
156599, 54-6096, 55-137.
No. 67, No. 55-13468, No. 57-164123.
No. 3, Japanese Patent Publication No. 3-2450, US Pat. No. 3,632,55
7, US Patent 4,345,053, US Patent 4,36
6,307, U.S. Pat. No. 4,960,844, and the like, and JP-A-61-197631.
No. 61-215622 and No. 61-215623.
Nos. 61-218632 and oxyalkylene polymers having a high number average molecular weight of 6,000 or more and a Mw / Mn of 1.6 or less and a narrow molecular weight distribution can be exemplified, but It is not limited to these. The above-mentioned oxyalkylene polymer containing a reactive silicon group may be used alone or in combination of two or more kinds. An oxyalkylene polymer obtained by blending a vinyl polymer having a reactive silicon group can also be used.

A method for producing an oxyalkylene polymer by blending a vinyl polymer having a reactive silicon group is disclosed in JP-A-59-122541 and JP-A-63-1264.
No. 2 and Japanese Patent Laid-Open No. 6-172631.

A preferred specific example is an acrylic acid ester monomer unit having a reactive silicon group and a molecular chain substantially having a C 1-8 alkyl group represented by the following general formula (5): (Or) A methacrylic acid ester monomer unit, an acrylic acid ester monomer unit having an alkyl group having 10 or more carbon atoms represented by the following general formula (6), and / or a methacrylic acid alkyl ester monomer In this method, a oxyalkylene polymer containing a reactive silicon group is blended with a unit copolymer.

—CH ₂ —C (R ⁶ ) (COOR ⁵ ) — (5) (In the formula, R ⁵ represents an alkyl group having 1 to 8 carbon atoms, and R ⁶ represents a hydrogen atom or a methyl group.) —CH ₂ —C (R ⁶ ) (COOR ⁷ ) — (6) (In the formula, R ⁶ is the same as above, R ⁷ represents an alkyl group having 10 or more carbon atoms.) As R ^{5 in the} general formula (5), For example, a methyl group,
Ethyl group, propyl group, n-butyl group, t-butyl group,
Examples thereof include alkyl groups having 1 to 8 carbon atoms, such as 2-ethylhexyl group, preferably 1 to 4 carbon atoms, and more preferably 1 to 2 carbon atoms. The monomer unit represented by the general formula (5) may be used alone or in combination of two or more. R ^{7 in the} general formula (6) is, for example, a lauryl group, a tridecyl group, a cetyl group, a stearyl group, an alkyl group having 22 carbon atoms, a behenyl group or the like having 10 or more carbon atoms, usually 10 to 10 carbon atoms.
There may be mentioned 30, preferably 10 to 20 long-chain alkyl groups. The monomer unit represented by the general formula (6) is 1
One kind may be used, or two or more kinds may be used.

The molecular chain of this vinyl-based copolymer consists essentially of the monomer units of (5) and formula (6), but the term "substantially" as used herein means that it exists in this copolymer. Expression (5)
And that the total of the monomer units of formula (6) exceeds 50% by weight. The total of the monomer units of formula (5) and formula (6) is preferably 70% by weight or more.

The abundance ratio of the monomer unit of the formula (5) and the monomer unit of the formula (6) is 95: 5 to 40:60 by weight.
Is preferred, and 90:10 to 60:40 is more preferred. Examples of the monomer unit other than the formula (5) and the formula (6) which may be contained in the copolymer include acrylic acid such as acrylic acid and methacrylic acid; acrylamide;
Methacrylamide, N-methylolacrylamide, N
-An amide group such as methylol methacrylamide, an epoxy group such as glycidyl acrylate and glycidyl methacrylate, an amino group-containing monomer such as diethylaminoethyl acrylate, diethylaminoethyl methacrylate and aminoethyl vinyl ether; other acrylonitrile, styrene, α-methylstyrene, Examples thereof include monomer units derived from alkyl vinyl ether, vinyl chloride, vinyl acetate, vinyl propionate, ethylene and the like.

This copolymer has a number average molecular weight of 500 to
100,000 is preferable from the viewpoint of easy handling. As the reactive silicon group contained in this copolymer, the same reactive silicon group in the oxyalkylene polymer as the component (a) used in the present invention can be used. The number of reactive silicon groups in the copolymerization is 1 or more on average from the viewpoint of obtaining sufficient curability, and further 1.1 or more,
Particularly, 1.5 or more is preferable, and the number average molecular weight per apparently reactive silicon group is 300 to 4,000.
Preferably, it is present so that

Further, as a method for producing an oxyalkylene polymer by blending a vinyl-based polymer having a reactive silicon functional group, in addition, in the presence of an oxyalkylene polymer having a reactive silicon group ( A method of polymerizing a (meth) acrylic acid ester-based monomer can be used. This manufacturing method is disclosed in JP-A-59-78223 and JP-A-59-78223.
No. 168,014, JP-A-60-228516, JP-A-60-228517, and the like, but the disclosure is not limited thereto.

The silica used in the component (b) of the present invention is preferably so-called fumed silica produced by flame hydrolysis of a silicon halogen compound. Examples of commercially available silica fine powders include the following. Some products are marketed under such trade names. AEROSIL 50, 130, 200, 300, 38
0, OX50, TT600, MOX80, MOX170
(Now Nippon Aerosil Co., Ltd.), REOLOSILQS-1
0, QS-20, QS-102, QS-30, QS-4
0 (above Tokuyama), Cabosil M-5, MS
-7, MS-75, HS-5, EH-5 (above CABO
Company T), Wacker HDK N20, T30, T4
0 (above WACKER CHEMIE)

As the organopolysiloxane used in the invention of the present application, which is a treatment agent for fine silica powder, any polymer known as organopolysiloxane can be used. Viscosity of organopolysiloxane is from 2 cSt to 1,000 cSt (25 ° C), especially 5 cSt
St to 500 cSt, more preferably 5 cSt to 100 cSt are desirable. If it is less than 2 cSt, it is easily volatilized and heat treatment cannot be performed. If it is more than 1,000 cSt, the viscosity is too high to process silica uniformly.

A specific example of the organopolysiloxane is an organopolysiloxane having a polymer chain represented by the following general formula. _{XR 2 Si-O (SiR 2} O) in _n -SiR ₂ X (wherein, X is an alkyl group, a hydroxyl group, a group selected from alkoxy group, R represents an alkyl group, a phenyl group, a polyether group, a polyether substituted alkyl group Represents a group selected from an epoxy-substituted alkyl group and a carbinol group, and a plurality of Rs may be the same or different, and n is 1
To an integer of 500. In the above formula, when R or X is an alkyl group, a methyl group, an ethyl group, etc. can be exemplified.

Examples of the organopolysiloxane include those sold under the following trade names. KF96L, KF96 (above dimethyl type), KF9
9 (methyl hydrogen type), KF50 (methyl phenyl type), KF410 (alkyl modified type), KF351, KF351A, KF353, KF3
55, KF615, KF618, KF945, KF90
7, X-22-6008, KF6011 (above polyether modified type), KF851 (alcohol modified type), X-22-819 (fluorine modified type), KF91
0 (higher fatty acid ester modified type), X-22-350
0 (carnauba modified type), KF3935 (amide modified type), KF393 (amino modified type) KF105
(Epoxy modified type), X-22-162A (carboxyl modified), KF6001 (carbinol modified type), X-22-164B, X-22-5002 (methacryl modified type), X-22-3667, X- 22-39
39A (polyether group and different functional group modified type), etc. (above Shin-Etsu Chemical Co., Ltd.), SH200, SH550, S
H1107, SH8411, SH8416, SH840
0, OFS546, 818B, etc. (Toray Dow Corning Silicone Co., Ltd.), TSF451, TSF431,
TSF483, TSF4420, TSF4730, etc. (Toshiba Silicone)

In the above formula, when R is a modified organopolysiloxane such as a polyether group, the position of the organic group may be either the side chain or the terminal of the polysiloxane. Among the organopolysiloxanes, a polyether-modified type polysiloxane having a polyether chain bonded to a side chain or a terminal thereof is particularly preferable because it is particularly excellent in viscosity and thixotropy.

As a method for producing these surface-treated silica, silica powder (for example, AEROSIL200) is put into a closed Henschel mixer, and 3 to 4 is added to 100 parts of silica.
0 parts by weight of organopolysiloxane (eg KF96-50cst) are added dropwise with rapid stirring. For uniform treatment, the organopolysiloxane is preferably diluted with a solvent such as hexane. 100-400 after dropping
The organopolysiloxane is chemically bonded to the silica surface by heat treatment at ℃. When the treatment amount of the organopolysiloxane is 3 parts by weight or less, the silica surface cannot be sufficiently covered, and silanol groups remain, which is not preferable. Over 40 parts by weight is not economical.

The composition of the present invention can use various plasticizers as required. When these additives are used so that the total amount of the plasticizer is in the range of 0.1 to 150 parts by weight with respect to 100 parts by weight of the oxyalkylene polymer, preferable results are obtained. If it exceeds 150 parts by weight, the liquid component increases and the improvement effect becomes small.

As the plasticizer, dioctyl phthalate,
Phthalates such as diisodecyl phthalate, dibutyl phthalate and butylbenzyl phthalate; epoxy plasticizers such as epoxidized soybean oil, epoxidized linseed oil and benzyl epoxy stearate; polyesters of dibasic acid and dihydric alcohol Polyester plasticizers such as; Polyethers such as polypropylene glycol and its derivatives; Polystyrenes such as poly-α-methylstyrene and polystyrene; Polybutadiene, butadiene-acrylonitrile copolymer, polychloroprene, polyisoprene, polybutene, chlorinated A plasticizer such as paraffin can be optionally used alone or in the form of a mixture of two or more kinds.

In the present invention, a curing catalyst that accelerates the curing reaction of the oxyalkylene polymer having at least one reactive silicon group in one molecule of the component (a) may be used. As this catalyst, a conventionally known silanol condensation catalyst (curing catalyst) can be widely used.

Specific examples thereof include titanic acid esters such as tetrabutyl titanate and tetrapropyl titanate; tin carboxylates such as dibutyltin dilaurate, dibutyltin maleate, dibutyltin diacetate, tin octylate and tin naphthenate; dibutyltin oxide and Reaction products with phthalates; dibutyltin diacetylacetonate; organoaluminum compounds such as aluminum trisacetylacetonate, aluminum trisethylacetoacetate, diisopropoxyaluminum ethylacetoacetate; zirconium tetraacetylacetonate, titanium tetraacetylacetonate Chelate compounds such as; lead octylate;
Iron naphthenate; bismuth compounds such as bismuth-tris (2-ethylhexoate); butylamine, octylamine, dibutylamine, monoethanolamine, diethanolamine, triatanolamine, diethylenetriamine, triethylenetetramine, oleylamine,
Cyclohexylamine, benzylamine, diethylaminopropylamine, xylylenediamine, triethylenediamine, guanidine, diphenylguanidine, 2,
4,6-tris (dimethylaminomethyl) phenol,
Morpholine, N-methylmorpholine, 2-ethyl-4-
Methyl imidazole, 1,8-diazabicyclo (5,
4,0) amine compounds such as undecene-7 (DBU), or salts of these amine compounds with carboxylic acids; low molecular weight polyamide resins obtained from excess polyamine and polybasic acid; excess polyamine and epoxy Reaction products with compounds; silane coupling agents having amino groups such as γ-aminopropyltrimethoxysilane and N- (β-aminoethyl) aminopropylmethyldimethoxysilane; silanol condensation catalysts such as; Known silanol condensation catalysts such as catalysts and basic catalysts can be mentioned. These catalysts may be used alone or 2
More than one kind may be used in combination.

The amount of these silanol condensation catalysts used is
0.1 to 100 parts by weight of oxyalkylene polymer
The amount is preferably about 20 parts by weight, more preferably about 1 to 10 parts by weight. If the amount of the silanol condensation catalyst used is too small with respect to the oxypropylene polymer, the curing rate will be slow and the curing reaction will not proceed sufficiently, which is not preferable. On the other hand, if the amount of the silanol condensation catalyst used is too large with respect to the oxyalkylene polymer, local heat generation or foaming occurs during curing, and it becomes difficult to obtain a good cured product, which is not preferable.

In the invention of this application, a low molecular weight silicon compound having a hydrolyzable functional group which reacts in the presence of moisture may be used in combination for the purpose of adjusting the physical properties of the cured product and removing the water content in the composition. . The molecular weight is preferably 500 or less. In addition, this compound preferably has a functional substituent.

Examples of the hydrolyzable functional group include an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an aminooxy group, an amido group and an alkenyloxy group.

Examples of the substituent include epoxy-containing group, amino-containing group, acryl-containing group, mercapto-containing group and the like. An example of such a compound is a silane coupling agent. These silane compounds may be used alone or in combination of two or more. Further, various additives such as a dehydrating agent, a physical property adjusting agent, a filler, and an antiaging agent may be appropriately added to the composition of the present invention as required. Hereinafter, the present invention will be specifically described with reference to examples.

[0038]

【Example】

Synthesis Example 1 100 parts by weight of silica fine powder (AEROSIL200, manufactured by Nippon Aerosil Co., Ltd.) produced by flame hydrolysis of a silicon halogen compound was placed in a closed Henschel mixer and stirred while substituting with nitrogen, and a viscosity of 50 cst as a treating agent was added thereto. After spray-mixing 20 parts by weight of the terminal methyl-capped dimethylpolysiloxane (KF96, manufactured by Shin-Etsu Chemical Co., Ltd.), the mixture was heated and stirred at 250 ° C. for 30 minutes to obtain a surface-dimethylpolysiloxane-treated silica (A).

Synthesis Example 2 Polysiloxane-treated silica (B) was obtained in the same manner as in Synthesis Example 1 except that the treating agent polysiloxane was polyether modified silicone oil KF618 (manufactured by Shin-Etsu Chemical Co., Ltd.).

Synthesis Example 3 Polysiloxane-treated silica (C) was prepared in the same manner as in Synthesis Example 1 except that the treating agent polysiloxane was polyether modified silicone oil KF351A (manufactured by Shin-Etsu Chemical Co., Ltd.).
I got

Synthetic Example 4 Polysiloxane-treated silica (D) was obtained in the same manner as in Synthetic Example 1 except that the treating agent polysiloxane was epoxy-modified silicone oil 818B (manufactured by Toray Dow Corning Silicone Co., Ltd.).

Synthetic Example 5 Polysiloxane-treated silica (E) was obtained in the same manner as in Synthetic Example 1 except that the treating agent polysiloxane was OFS546 (manufactured by Dow Corning Toray Silicone Co., Ltd.) modified with hydroxyl groups at both ends. It was

Example 1 60 parts by weight of a propylene oxide polymer having a number average molecular weight of 8,000 and containing an average of 1.4 methyldimethoxysilyl groups —Si (CH ₃ ) (OCH ₃ ) ₂ per molecule, and 1 Number average molecular weight 9,0 containing an average of 2.2 methyldimethoxysilyl groups per molecule
To a mixture of 40 parts by weight of the propylene oxide polymer of No. 00, 3 parts by weight of the surface-dimethylpolysiloxane-treated silica (A) of Synthesis Example 1 was directly added as a powder as an anti-sagging agent,
DOP (dioctyl phthalate) 5 as a plasticizer
0 parts by weight, 100 parts by weight of surface-treated colloidal calcium carbonate as a filler, and 35 parts by weight of ground calcium carbonate were added. After kneading with a spatula in advance, it was passed through a small three-piece paint roll three times to obtain a composition. The obtained composition was put in a glass container (K-5) and stored at 23 ° C. for 15 days. The viscosity and thixotropy of this were measured using a BS type viscometer at 23 ° C. The results are shown in Table 1. The viscosity indicates a viscosity value at 2 rpm. The viscosity ratio was determined from the ratio of the viscosity at 2 rpm to the viscosity at 10 rpm.

[0044]

[Table 1]

Example 2 The same procedure as in Example 1 was carried out except that as the anti-sagging agent, a commercially available product RY200S (produced by Nippon Aerosil Co., Ltd.) having surface dimethylpolysiloxane was used as it was.

Comparative Examples 1 and 2 As the anti-sagging agent, surface silane treated hydrophobic treated silica R
972, RX200 (manufactured by Nippon Aerosil Co., Ltd.) was used in the same manner as in Example 1 except that it was used.

Comparative Example 3 The procedure of Example 1 was repeated except that the anti-sagging agent was not used.

Example 3 60 parts by weight of a propylene oxide polymer having a number average molecular weight of 8,000 and containing an average of 1.4 methyldimethoxysilyl groups —Si (CH ₃ ) (OCH ₃ ) ₂ per molecule, and 1 Number average molecular weight 9,0 containing an average of 2.2 methyldimethoxysilyl groups per molecule
3 parts by weight of the surface-dimethylpolysiloxane-treated silica (A) of Synthesis Example 1 was used as an anti-sagging agent in a mixture of 40 parts by weight of the propylene oxide polymer of No. 00. It was passed around to obtain a composition. The obtained composition was put in a glass container (K-8) having a diameter of 3.6 cm and stored at 23 ° C. for 7 days. This is 23
Viscosity and thixotropy were measured using a BH type viscometer at ° C. The results are shown in Tables 2 and 3. The viscosity indicates a viscosity value at 2 rpm. Viscosity ratio is 2 rpm and 10 rpm
It was determined by the ratio with the viscosity at the time. Transparency is 3.6 cm in diameter
The sample placed in the glass container (K-8) of No. 1 was visually observed.

[0049]

[Table 2]

[0050]

[Table 3]

Example 4 The same procedure as in Example 3 was carried out except that as the anti-sagging agent, a commercially available product RY200S (produced by Nippon Aerosil Co., Ltd.) having surface dimethylpolysiloxane was used as it was.

Example 5 Example 5 was repeated except that the surface-polyether-modified silicone-treated silica (B) of Synthesis Example 2 was used as the anti-sagging agent.

Example 6 The procedure of Example 3 was repeated, except that the surface-polyether-modified silicone-treated silica (C) of Synthesis Example 3 was used as the anti-sagging agent.

Example 7 Example 7 was carried out in the same manner as in Example 3 except that the surface-epoxy-modified silicone-treated silica (D) of Synthesis Example 4 was used as the anti-sagging agent.

Example 8 Example 8 was carried out in the same manner as in Example 3 except that the surface-modified hydroxyl group-modified silicone treated silica (E) of Synthesis Example 5 was used as the anti-sagging agent.

Comparative Examples 4 to 7 As the anti-sagging agent, surface silane treated hydrophobic treated silica R
972, RX200 (manufactured by Nippon Aerosil Co., Ltd.), hydrogenated castor oil, and aliphatic amide wax were used as they were in the same manner as in Example 3.

Comparative Example 8 The procedure of Example 3 was repeated except that the anti-sagging agent was not used.

[0058]

EFFECTS OF THE INVENTION As described above, the curable composition of the present invention can provide a composition having excellent viscosity and thixotropy and excellent transparency.

Claims (7)

[Claims] 1. An oxyalkylene polymer having at least one reactive silicon group in one molecule, and (b) a fine silica powder surface-treated with an organopolysiloxane. Curable composition. Wherein the silica is a silica produced by flame hydrolysis of silicon halide, characterized in that the specific surface area of 20m ² / g~400m ² / g by a nitrogen adsorption method (BET method) The curable composition according to claim 1. 3. The curable composition according to claim 1, wherein the organopolysiloxane is an organopolysiloxane having a polymer chain represented by the following general formula. _{XR 2 Si-O (SiR 2} O) in _n -SiR ₂ X (wherein, X is an alkyl group, a hydroxyl group, a group selected from alkoxy group, R represents an alkyl group, a phenyl group, a polyether group, a polyether substituted alkyl group , An epoxy-substituted alkyl group, a carbinol group, R may be the same or different, and n represents an integer of 1 to 500.) 4. The curable composition according to claim 1, wherein the organopolysiloxane is a polyether group- or polyether-substituted alkyl group-modified polysiloxane. 5. The curable composition according to claim 1, wherein the treatment amount of the organopolysiloxane is 3 to 40 parts by weight based on 100 parts by weight of silica. 6. An oxyalkylene polymer having at least one reactive silicon group in one molecule, and (b) a fine silica powder surface-treated with an organopolysiloxane. Curable composition for sealants. 7. An oxyalkylene polymer containing at least one reactive silicon group in one molecule, and (b) a fine silica powder surface-treated with an organopolysiloxane. Curable composition for adhesion.