JPS62151455A - Room temperature-curable composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition free from deterioration in mechanical properties, with good storage stability in one packaging form, suitable as construction sealing materials, by incorporating a specific polymer carrying hydrolyzable silicon functional group with specified amount of active alumina fine powder, etc. CONSTITUTION:The objective composition can be obtained by incorporating (A) 100pts.wt. of a hydrolyzable silicon functional group (said hydrolyzable group being e.g. alkoxy one)-contg. polymer with its main chain essentially constituted by polyether (e.g. polypropylene oxide) with (B) 0.05-200 (pref. 1-50)pts. by wt. of active alumina fine powder with an average particle size <=10mu and (C) 0.001-10pts.wt. of a curing catalyst (e.g. tin octanoate).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a room temperature curable composition, and more particularly to a composition that has excellent storage stability in the form of a single package and has no deterioration in mechanical properties after storage. .

[Conventional technology and its problems]

A composition having a hydrolyzable silicon functional group and having a main chain essentially a polyether as a base polymer is disclosed in Japanese Patent Application Laid-Open No. 52-73998, etc.
In recent years, this type of composition has begun to be used as a sealant for joints in buildings. This type of sealant was initially used in two packages, but one package that did not require mixing was used.
The use of packaged forms is increasing.

As a method of imparting self-adhesive properties and long-term storage stability to such single-packed sealant compositions, it has been proposed in Japanese Patent Application Laid-Open No. 57-1997 to add an alkoxysilane having three or more alkoxy groups in the molecule. It is described in No. 205443 and is used for -1'lQ. However, this type of sealant containing an organosilicon compound has insufficient stability during long-term storage. In addition, an example of using zeolite is JP-A-59-11
No. 3051 discloses this method, but although it is possible to improve the surface curing failure, problems such as an increase in viscosity occur during long-term storage.

It is an object of the present invention to provide a room-temperature curable composition based on a polymer having hydrolyzable silicon functional groups and whose main chain is essentially a polyether, which exhibits excellent storage stability in single package form and An object of the present invention is to provide a room-temperature curable composition without deterioration of physical properties.

[Means for solving problems]

As a result of intensive studies on methods to improve the above-mentioned problems, the present inventor found that by incorporating activated alumina fine powder with adsorption properties, the increase in viscosity is extremely small even after long-term storage in a single package, and The present inventors have discovered that it is possible to obtain a composition that exhibits no retardation in the curing speed after exposure to water, and have completed the present invention.

That is, the present invention comprises: (A) 100 parts by weight of a polymer having a hydrolyzable silicon functional group and whose main chain is a woody polyether; (B) 0.05 to 200 parts by weight of activated alumina fine powder; and (C) ) A room temperature curable composition characterized by comprising o, ooi to 10 parts by weight of a curing catalyst.

The polymer (A) in the present invention has a crosslinkable silicon-functional group, and the main chain essentially has the formula R-0 (wherein R is a divalent alkylene group having 2 to 4 carbon atoms). ), and by having a silicon atom and a hydrolyzable group bonded to it,
It is a polymer that can be crosslinked by moisture in the air.

Examples of the structural unit represented by -R-0- include CHz CHzCHi -CH2CH20-, -CHCHzO-3-CHCHz
O-1-CHzClhCHzO-1-CHzCHzCH
Specific examples include zClhO-. As polyether, these structural units may be bonded not only by one type but also by a mixture of two or more types of structural units, but those with a relatively high degree of polymerization are easily bonded. A polyether produced using propylene oxide as a raw material is particularly preferred because it is liquid at room temperature even at a high degree of polymerization. It is also preferred that the hydrolyzable silicon functional groups are present at the ends of the polyether polymer. Examples of the hydrolyzable group include an alkoxy group, an acyloxy group, an amino group, an aminoxy group, an oxime group, a ketoxime group, an amide group, an alkenyloxy group, and a halogen atom. Among these, alkoxy groups are preferred because they have no risk of damaging the adherend and generate a weak odor during the curing reaction, and methoxy groups are more preferred because they provide an appropriate curing speed.

Component (B) used in the present invention has a composition that exhibits almost no thickening even when stored for a long period of time in the form of a single package, and does not slow down the curing speed after being exposed to the outside air, which is a characteristic of the present invention. It is an essential ingredient for obtaining things. These are selected from activated alumina fine powders with adsorption properties, and those obtained by firing alumina hydrates such as alumina hydroxide and bauxite are recommended for this use.

These (B) component a powders have an average particle size of
It is desirable that it is 0μ or less. The blending amount of these components (B) is 0.05 to 2 parts by weight per 100 parts by weight of component (A).
00 parts by weight, preferably in the range of 1 to 50 parts by weight.

If the amount of component (B) is less than 0.05 parts by weight, the effect of preventing thickening and curing speed retardation during storage will not be obtained;
If the amount exceeds the weight part, the physical properties of the rubber-like elastic body after curing,
In particular, the elongation rate decreases.

Incidentally, silica-based oxide fine powders exist as inorganic powders with adsorption properties, but although these are effective in preventing retardation of the curing speed after storage, they increase the thixotropic properties of the composition over time. In addition to reducing workability, the longer the storage period, the harder the rubber-like elastic material becomes after curing.
Its use is undesirable because it lowers the elongation rate.

On the other hand, such a problem does not arise with component (B) used in the present invention.

The curing catalyst (C) in the present invention includes tin carboxylates such as tin octylate; reactants with organic tin compounds and esters thereof such as dibutyltin dilaurate, dibutyltin dilaurate, and dibutyltin phthalate; such as tetrabutyl titanate. organic titanate ester;
Examples include amines, amine salts, quaternary ammonium salts, and guanidine compounds. These curing catalysts are used in an amount of 0.001 to 10 parts by weight per 100 parts by weight of component (A). If the amount of component (C) is less than this, the curing speed is too slow and it is not suitable for use as a sealant (on the contrary, if it is more than this, it is not only meaningless, but also may cause oozing or precipitation. Undesirable.

In addition to the above essential components, the room temperature curable composition of the present invention includes:
An inorganic filler may be contained for the purpose of obtaining reinforcing properties and appropriately adjusting fluidity. Examples of these inorganic fillers include calcium carbonate, ground quartz, diatomaceous earth, talc, and clay. Furthermore, the room temperature curable composition of the present invention may contain other additives such as a thixotropic agent, a coloring pigment, and an ultraviolet absorber.

In addition, silicon compounds such as those shown below may be added to the composition of the present invention for the purpose of imparting self-adhesive properties.

HzNCHzCHzCHzSi (OCH3) z,H
zNCHzCHzCHzSi (OCI(zcHt)
3, HzNCHzCHzNHCHzCHzCHzS
i (OCHz) 3, CH3 ■ CHz=C-C-OCHzCHzCHzSi (OCI
I:l) 3, CHz=(JISi (OCHzCHi
) 3, HSCHzCHzCHzSi (OCH3)
3 [Effects of the Invention] The room temperature curable composition of the present invention can be used by packaging components (8) to (C) and other components as necessary, and has good storage stability. , and does not lose its initial hardenability and mechanical properties even after storage. Therefore, it is extremely suitable as a sealing material for construction.

〔Example〕

The present invention will be explained below using examples. In the examples, all parts are parts by weight, and physical properties such as viscosity are measured at 25°C.

Preparation Example 1 Average molecular weight is about 8000, as a terminal group? 113 (CIhO) 2Si-C) 12C)1. 100 parts of fatty acid-treated colloidal calcium carbonate, 20 parts of rutile-type titanium oxide, 40 parts of dioctyl phthalate, and 3 parts of hydrogenated castor oil were added to 100 parts of polyoxypropylene having a CH2O group and mixed uniformly using a triple roll. A blend was prepared and then kneaded at 60 to 70° C. and 5 Torr for 30 minutes to obtain a main ingredient (X-1).

Preparation Example 2 50 parts of fatty acid-treated colloidal calcium carbonate and 50 parts of ground calcium carbonate were added to 100 parts by weight of polyoxypropylene having an average molecular weight of about 12,000 and a terminal group of CH3 (CH: +0) zsi-CHzCIIzCH2〇-. , 30 parts of dioctyl phthalate, 6 parts of hydrogenated castor oil
parts, 20 parts of rutile titanium oxide, 2 parts of bisphenol antioxidant, 2 parts of benzotriazole ultraviolet absorber,
After adding 2 parts of Penzimidazur Rubamate fungicide and 0.5 part of carbon blank and mixing uniformly with a triple roll, kneading was carried out for 30 minutes at 60-70°C and 15 Torr. ) was obtained.

Examples 1 to 3 100 parts of the base material (X-1) obtained in Preparation Example 1 were mixed with activated γ-alumina fine powder with an average particle size of 3μ in the amounts shown in Table 1, a curing catalyst, and a hydrolyzable silane. Inventive product samples Y-1 to Y-3 were obtained.

After measuring the viscosity of the sample thus obtained at 25°C, it was spread on a Teflon plate to a thickness of about 2 fm, and the drying time to the touch at 25°C and 60% relative humidity was measured. The rubber sheet was then cured for 14 days under the same conditions to obtain a rubber sheet, and its physical properties were measured using a JISZ dumbbell. These results are also shown in Table 1. In addition, a portion of the sample was sealed in a metal tube and stored in a constant temperature bath at 70° C. for 28 days, and then similar measurements were performed. The results are also shown in Table 1.

Comparative Example 1 100 parts of the base material (X-1) obtained in Preparation Example 1 were mixed with zeolite fine powder (Molecular Sieve 3A manufactured by Union Showa Corporation), a curing catalyst, and a hydrolyzable silane in the amounts shown in Table 1. A comparative sample Z-1 was obtained. The same measurements as in Examples 1 to 3 were performed using the obtained samples. The result is also the first
Shown in the table.

Comparative Example 2 Comparative sample Z-2 was obtained by mixing 100 parts of the base material (X-1) obtained in Preparation Example 1 with the amounts of curing catalyst and hydrolyzable silane shown in Table 1. Using the obtained samples, the same measurements as in Examples 1 to 3 were performed. The results are also shown in Table 1.

Examples 4 to 6 Activated γ-alumina imitation powder with an average particle size of 1.2μ, a tin catalyst, and a hydrolyzable amount were added to 100 parts of the base material (X-2) obtained in Preparation Example 2 in the amounts shown in Table 2. By mixing silane, inventive product samples Y-4 to Y-6 were obtained. The same measurements as in Examples 1 to 3 were performed on these samples. The results are shown in Table 2.

Comparative Example 3 Comparative sample Z-3 was obtained by mixing 100 parts of the base material (X-2) obtained in Preparation Example 2 with the amounts of tin catalyst and hydrolyzable silane shown in Table 2. In this sample, Examples 1 to 3
The same measurements were carried out.

The results are also shown in Table 2.

Claims (1)

[Scope of Claims] 1 (A) 100 parts by weight of a polymer having hydrolyzable silicon functional groups and whose main chain is essentially polyether (B) 0.05 to 200 parts by weight of activated alumina fine powder; (C) A room temperature curable composition comprising 0.001 to 10 parts by weight of a curing catalyst. 2. The composition according to claim 1, wherein the polyether (A) is polypropylene oxide. 3. The composition according to claim 1 or 2, wherein the hydrolyzable group in (A) is an alkoxy group. 4. Any one of claims 1 to 3, wherein (B) is an activated alumina fine powder with an average particle size of 10μ or less
The composition described in Section.