JP2001172610A - Modified silicone-based sealing material for building use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-component modified silicone-based sealing material having good curability at the deep part. SOLUTION: The objective two-component modified silicone-based sealing material for building use is composed of (A) a rubbery organic polymer having Si-bonded hydroxyl group and/or hydrolyzable group and at least one Si- containing group crosslinkable by the formation of a siloxane bond, (B) a straight-chain polyether-modified silicone-based surfactant, (C) a water-containing base agent and (D) a curing agent containing a silanol condensation catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modified silicone-based sealing material for buildings, which is filled between joints on the interior and exterior of buildings and joints at joints to prevent the penetration of wind and rain.

More specifically, the present invention relates to a modified silicone sealing material which belongs to a building sealing material system specified in JIS A 5758 and is fast-curing and has good deep-curing properties.

[0003]

2. Description of the Related Art A modified silicone sealing material for construction is provided as one or two components prepared in the form of a paste, which is filled into a joint of a building, applied and cured. The main component is a rubber-based organic polymer having a silicon group which can be crosslinked by forming a siloxane bond (hereinafter referred to as a modified silicone resin). Usually, a curing agent, a curing accelerator,
It is composed of a curing retarder, a plasticizer, a filler, a dye / pigment, an ultraviolet absorber, an antioxidant and the like. The modified silicone resin is cured by reacting with moisture in the air by the action of a curing catalyst, and develops rubber elasticity.

[0004] In the one-component form, a curing catalyst is added to a dehydrated denatured modified silicone resin or another compound, and the mixture is supplied in a hermetically sealed manner. on the other hand,
The two-component type comprises a base containing a modified silicone resin and a curing agent containing a silanol condensation catalyst, and is cured by mixing the base and the curing agent with the moisture in the base and the moisture in the air. In the two-component type, since the base and the curing agent are packaged separately, the choice of curing catalyst is wide. Therefore, it is possible to design a sealing material having better storage stability and better deep-section curability than the one-component type, and good sealing properties can be obtained from an early stage.

[0005]

However, even in the case of the two-component type, there is a disadvantage that the curing speed is extremely delayed when the supply of moisture is small. That is, when the joint is filled into the joint as a building sealing material, the deep cured property of the cured product may be insufficient even in the two-component form depending on the joint shape. In addition, when the temperature is low and the humidity is low, the curability deteriorates.

Particularly, in a high-rise building or the like in which a two-component type sealing material is frequently used, it is necessary to develop a sealing property at an early stage. I have.

On the other hand, a method of increasing the amount of the curing catalyst to improve the curability is conceivable, but in this case, the extrudable time from the start of mixing to the filling of the joint and the finishable time of the surface spatula are shortened and workability is deteriorated. Further, addition of an excessive curing catalyst lowers weather resistance, durability and the like.

In order to improve the curability, a method of mixing moisture in a base, a method of mixing a water-containing substance, and the like have been proposed, but none of them has a sufficient effect.

Further, when water is mixed into the base by the above-mentioned method, the modified silicone resin has poor compatibility with water, so that the dispersion becomes insufficient and the curability varies, and the adsorption to the filler becomes difficult. For example, the viscosity and thixotropic properties vary, and the workability deteriorates, and the adhesion-providing component and water react with each other, resulting in variations in adhesion. Furthermore, the addition of excess water may reduce the catalytic activity, and conversely, cure may be delayed.

[0010] The present invention has been made in view of the above problems, and has as its object to provide a two-component modified silicone-based sealing material having excellent fast-curing and deep-curing properties.

The present inventors have solved the above-mentioned problem by
As a result of various studies, it was found that mixing a specific silicone compound and water in the base improved the deep curing property, and led to the present invention.

[0012]

That is, the present invention provides:
(A) a rubber-based organic polymer having at least one silicon-containing group that has a hydroxyl group and / or a hydrolyzable group bonded to a silicon atom and can be cross-linked by forming a siloxane bond; The present invention relates to a two-component modified silicone-based sealing material for building, comprising a polyether-modified silicone-based surfactant, (C) a base containing water, and (D) a curing agent containing a silanol condensation catalyst.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the modified silicone resin (A) include, for example, polymers in which the main chain is substantially a polymer such as polyether or acrylic and a reactive silicone functional group is introduced. The number average molecular weight is 3,000
~ 30,000 is preferred, more preferably 15,000.
It is from 0 to 20,000 and is generally called a modified silicone resin. As specific examples of these, "MS Polymer" (manufactured by Kanegafuchi Chemical Industry Co., Ltd.) and "EXETER" (manufactured by Asahi Glass Co., Ltd.), which are already industrially produced.
Can be used.

The linear polyether-modified silicone surfactant (B) is a linear block polymer in which dimethyl silicone and polyether are alternately and repeatedly bonded.

The structure shown in the following formula can be used. These are thought to exhibit the above-mentioned effects because they contain water in the molecular chain and are uniformly dispersed in the base material by the action of hydrophobic dimethyl silicone and hydrophilic polyethylene oxide. Specific examples of these are “FZ2222”, “FZ2203”, and “FZ220” manufactured by Nippon Unicar Co., Ltd.
7 "and the like.

[0015]

Embedded image Here, R and R ′ are an alkyl group, an aryl group, an aralkyl group, EO is a polyethylene oxide chain, PO is a polypropylene oxide chain, a and b are 0 or an integer of 1 or more, and n is an integer of 1 or more. . Where a,
Although the numerical values of b and n are not particularly limited, generally, as the ratio of EO increases, the water retention tends to increase.
Any grade can be selected in consideration of the compounding system.

(C) The method of adding water is not particularly limited, but a method of mixing the masterbatch previously mixed in (B) with the remaining base components in order to uniformly disperse, and (A) in (A) After mixing (B), (C) is added, and the mixture can be mixed by a method such as high-speed stirring and dispersion.
The compounding amount of (B) and (C) is 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of (A).

Examples of the silanol condensation catalyst (D) include known silanol catalysts such as titanates, tin carboxylate salts, organoaluminum compounds, amine compounds, acidic catalysts and basic catalysts. These catalysts may be used alone or in combination of two or more.

As other compounding agents of the present invention, a plasticizer and a filler are required, and further, a curing accelerator, a curing retarder,
Dyeing / pigment, surface tackiness inhibitor, anti-sagging agent, adhesion promoter, ultraviolet absorber, antioxidant and other additives are used as required.

As the plasticizer, dioctyl phthalate,
Ester plasticizers such as dibutyl phthalate, butyl benzyl phthalate, dioctyl adipate, isodecyl succinate, dibutyl sebacate; phosphates; epoxy plasticizers such as epoxidized soybean oil and benzyl epoxystearate; chlorinated paraffin Can be used for ensuring workability and imparting flexibility.

As the filler, an inorganic filler such as calcium carbonate, talc, kaolin or the like is used as a sealing material for a building. In order to impart proper thixotropic property, 150 to 25 parts by weight per 100 parts by weight of the modified silicone resin is used.
Use 0 parts by weight.

[0021]

Next, the present invention will be specifically described based on examples of the sealing material of the present invention. (Examples 1 to 3 and Comparative Examples 1 and 2) According to the base composition shown in Table 1, each component was kneaded with a butterfly mixer and then dispersed with three rolls. Thereafter, the mixture was remixed and degassed with a butterfly mixer to obtain a base. Also, according to the curing agent formulation in Table 1, a curing catalyst, a plasticizer, and a
The filler was mixed with a butterfly mixer under a nitrogen stream and stored in a moisture-proof container as a curing agent.

(Test Method) (1) Surface Skinning Time The skinning time on the surface was determined by finger touch. (2) 10 mm thick curing time The cured film was cured under low humidity (23 ° C., 30%), the cured film after aging was taken out, and the time when the thickness reached 10 mm was measured.

[0023]

[Table 1]

[0024]

[Table 2]

[0025]

The sealing material of the present invention has an effect that a good deep curability can be obtained by adding a small amount of water even under low humidity.

Claims (1)

[Claims] 1. A rubber-based organic polymer having (A) a hydroxyl group and / or a hydrolyzable group bonded to a silicon atom and having at least one silicon-containing group which can be crosslinked by forming a siloxane bond. , (B) a linear polyether-modified silicone-based surfactant, (C) a base containing water, and (D) a curing agent containing a silanol condensation catalyst, a two-component modified silicone sealant for architectural use. Material composition.