JP2849883B2 - Sealant composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sealant composition and a method for using the same.

[0002]

2. Description of the Related Art A sizing board is a plate made of various materials used for an outer wall of a building or the like. When the sizing board itself is attached, a gap (joint) always occurs between the sizing board and another member of the building or between the sizing board and another sizing board. The joint is filled with a sealing material to provide waterproofness and shut off from outside air.

[0003] The width of the joint fluctuates due to changes in temperature, movement of the building, and the like. Therefore, the sealing material needs to have excellent rubber properties, that is, excellent resilience, so that it can follow the fluctuation of the width. In other words, once the joint has expanded or narrowed, and then returned to its original width, it is necessary to restore the sealing material to its original state, and the sealing material remains expanded without being restored or remains contracted In the state (2), there are problems that the appearance is impaired and the sealing material peels off from the adhesive surface. Peeling is particularly fatal to the sealing material.

[0004] The resilience of the sealing material is JIS A5758.
, And those positioned in the section 9030 have excellent resilience. However, in the case of a sealing material using a reactive silicon group-containing polyoxyalkylene polymer (a modified silicon-based material in the above JIS), even a material belonging to the category 9030 may be peeled off from the interface with time. The usual solutions to this problem are to add an adhesive to the sealing material or apply a primer to the surface of the sizing board to increase the adhesive strength. A method for reducing the stress on the interface is conceivable. However, these methods have problems that they are complicated, increase the cost, and change the physical properties of the cured product.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a sealing material composition having excellent adhesion durability by a method other than the above.

[0006]

Means for Solving the Problems The present inventors have determined that the sizing board joint does not have a specific movement, that is, expansion and contraction around a fixed joint width (this corresponds to the durability test of JIS A5758). Focusing on the movement in a certain direction (the direction in which the joints spread) due to shrinkage due to drying of the board, and the accompanying movement in a certain direction out of the plane of the board due to warpage and torsion, the present invention resulted in the present invention Reached.

[0007] That is, peeling often occurs at locations where there is movement in the direction in which the joints spread, and in such locations, rather than a sealing material having good resilience, the resilience is poor and deformation is fixed, and no stress is applied to the interface. It is appropriate to use a sealing material. It has been found that even when a sealing material having poor restoring property is used, it can be used satisfactorily even at a place where joint expansion and contraction is repeated, even though the expansion and contraction is not so large as to be considered. Accordingly, the above-mentioned object is achieved by a sealing material composition for a sizing board comprising a reactive silicon group-containing polyoxyalkylene polymer having a heat compression recovery ratio of a cured product of 10% or less.

In the present invention, the heat compression recovery ratio is defined by JIS
In accordance with the durability evaluation section of A5758, it is calculated by the following equation (1) using the numbers measured after one cycle at 90 ° C. and left at room temperature for one day. Heat compression restoration ratio = (L ₂ −L ₁ / L ₀ −L ₁ ) × 100 (1) where L ₀ : thickness of the sealing material in the compression direction before heat compression L ₁ : at the time of heat compression Thickness of the sealing material in the compression direction L ₂ : Thickness in the compression direction of the sealing material after one cycle of the JIS A5758 durability 9030 test and left at room temperature for one day.

Typical reactive silicon groups of the reactive silicon group-containing polyoxyalkylene polymer include, for example, groups represented by the following general formula (1).

[0010]

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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,
An aralkyl group having 7 to 20 carbon atoms or (R ³ ) ₃ SiO
Represents a triorganosiloxy group represented by-, and when two or more R ¹ or R ² are present, they may be the same or different. Here, R ³ has 1 to 2 carbon atoms.
0 is a monovalent hydrocarbon group, and three R ^{3 s} 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, 2 or 3 represents b, and 0 represents 1, 1 or 2. Further, b in the following m groups may be different. m shows the integer of 0-19. However, a + Σ
It is assumed that b ≧ 1 is satisfied. ]

[0012]

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The hydrolyzable group represented by X 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,
An alkenyloxy group and the like can be mentioned. Of these,
A hydrogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an aminooxy group, a mercapto group and an alkenyloxy group are preferred. Particularly preferred.

This hydrolyzable group or hydroxyl group can be bonded to one to three silicon atoms, and (a + Δb) is 1
-5 is preferred. When two or more hydrolyzable groups or hydroxyl groups are present in the reactive silicon, they may be the same or different. In the reactive silicon, there may be one silicon atom or two or more silicon atoms. In the case of a reactive silicon group in which silicon atoms are linked by a siloxane bond or the like, about 20 silicon atoms may be present. Good. The reactive silicon group represented by the following general formula (2) is preferable from the viewpoint of easy availability.

[0015]

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Wherein R ² , X and a are the same as above. Specific examples of R ¹ and R ² in the general formula (1) include, for example, an alkyl group such as a methyl group and an ethyl group, a cycloalkyl group such as a cyclohexyl group, an aryl group such as a phenyl group, and a benzyl group. An aralkyl group such as (R ³ ) _{3 wherein} R ³ is a methyl group or a phenyl group;
And a triorganosiloxy group represented by SiO—. As R ¹ , R ² and R ³ , a methyl group is particularly preferred. It is preferable that at least one, preferably 1.1 to 5 reactive silicon groups be present in one molecule of the oxyalkylene polymer. When the number of reactive silicon groups contained in one polymer molecule is less than one, the curability becomes insufficient and 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 therein. When the reactive silicon group is present at the terminal of the molecular chain, the effective network chain amount of the oxyalkylene polymer component contained in the finally formed cured product increases, so that high strength, high elongation, and low elastic modulus are obtained. The resulting rubber-like cured product 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)-(RO) _n- : (R represents a divalent alkylene group having 1 to 4 carbon atoms, n represents the number of repetitions) However, from the viewpoint of availability, An oxyalkylene polymer having a repeating unit represented by the following general formula (4) is preferable.

Formula (4) -CH (CH ₃ ) CH ₂ O- The oxyalkylene polymer may be linear or branched, or 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 by 50%.
It is preferably present in an amount of at least 80% by weight, preferably at least 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 introduction of the reactive silicon group may be performed by a known method. That is, for example, the following method is 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 having reactivity to the functional group, or an epoxy compound having an unsaturated group is used. To obtain an unsaturated group-containing oxyalkylene polymer obtained by copolymerization of Next, the obtained reaction product is reacted with hydrosilane having a reactive silicon group to effect hydrosilylation. (2) A compound having a mercapto group and a reactive silicon group is reacted with the unsaturated group-containing oxyalkylene polymer obtained in the same manner as in the method (1). (3) a hydroxyl group at a terminal, functional groups such as epoxy group or an isocyanate group (hereinafter, Y ¹ as functional group) to the oxypropylene polymer having a functional group (hereinafter reactive toward 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, γ-aminopropyltriethoxysilane Amino group-containing silanes such as γ-
Mercapto group-containing silanes such as mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane; γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, etc. Epoxysilanes; vinyl-type unsaturated group-containing silane groups such as vinyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-acryloyloxypropylmethyldimethoxysilane; and γ-chloropropyltrimethoxysilane. Silanes containing chlorine atoms;
γ-isocyanatopropyltriethoxysilane, γ-
Isocyanate-containing silanes such as isocyanatopropylmethyldimethoxysilane and the like; hydrosilanes such as methyldiethoxysilane and the like 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 terminal hydroxyl group with a compound having an isocyanate group and a reactive silicon group is preferable.

The reactive silicon group-containing oxyalkylene organic polymer is not particularly limited, but typical examples thereof include, for example, JP-A-50-15659.
No. 9, No. 54-6096, No. 57-126823,
Nos. 59-78223, 55-82123, 55
-131022, 55-137129, 62-
No. 230822, No. 63-83131, JP-A No. 3-4
No. 7825, No. 3-72527, No. 3-122152
Nos. 3,632,557 and 4,345.
053, 4,366,307, 4,960,8
No. 44 and the like can be exemplified.

Among these polymers, JP-A-3-4782
No. 5, 3-72527, and 3-122152, the tensile modulus is obtained by using a polymer having a molecular weight of 10,000 or more and a molecular weight distribution ( _Mw / _Mn ) of 1.5 or less. It is possible to obtain a cured product having a small particle size and to effectively prevent peeling of the cured product from the interface. The molecular weight distribution and molecular weight were measured using a Tosoh high-speed gel permeation chromatograph HLC8020 and T
SK gel G3000H and G4000H connected in series, THF as solvent, 40.0 ° C as measurement temperature,
The measurement can be performed by using a solution obtained by dissolving a sample solution having a solvent flow rate of 1.0 ml / min and a sample solution of 0.05 g in 10 cc of THF. Further, the heat-compression restoration ratio of the cured product can be reduced to 10% or less by using a tetravalent tin compound as a curing catalyst. Note that the use of a divalent tin compound increases the restoration rate. In applying the sealing material to the sizing board, a primer can be used as needed.

[0024]

The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Examples 1-2, Comparative Example 1 85% of all terminals (CH ₃ O) ₂ Si (CH ₃ ) CH ₂
A polyoxypropylene polymer having a CH ₂ CH ₂ — group, a number average molecular weight of 5,000 and a molecular weight distribution (M _w / M _n ) of 2.0 was used, and dibutyltin phthalate, tin octylate, and laurylamine were used as curing catalysts. By using a mixed catalyst and changing the ratio of dibutyltin phthalate and tin octylate, the heat compression recovery ratio of the cured product was 3%, 10%, and 3%.
A curable sealing material composition of 0% was obtained. Regarding these sealing materials, a commercially available sizing board [length (a) × width (b) × height (c)] is 10 cm ×
A test piece cut into a square of 5 cm × 1.2 cm was sealed with a sealing material [width (d) × length (e)] of 1.2 c as shown in FIG.
After being cured at room temperature for 7 days and then at 50 ° C. for 7 days, it was subjected to 30% tensile deformation [width (1.3d) = f] (shown in FIG. 2) and 10 °. A torsional deformation [torsion angle Θ] (shown in FIG. 3) was given (in this case, Θ = 10 °), and left standing at room temperature for one month while applying a stress, and then the adhesion state was observed. The observation results are also shown in Table 1 below.

[0026]

[Table 1]

Example 3 (CH ₃ O) ₂ Si (CH ₃ ) CH ₂ was added to 85% of all terminals.
It contains a CH ₂ CH ₂ — group and has a number average molecular weight of 10,000
0. A sealing material having a heat compression recovery ratio of 10% was obtained using a polyoxypropylene polymer having a molecular weight distribution ( _Mw / _Mn ) of 1.3 measured by gel permeation chromatography. A test similar to the above was conducted on this sealing material, but no abnormality was found in any case of 30% tensile deformation and 10 ° twist.

[0028]

According to the present invention, a sealing material composition having excellent adhesion durability can be provided.

[Brief description of figures]

FIG. 1 is a schematic diagram of a sizing board test piece cut into a 10 cm × 5 cm × 1.2 cm square, and a sealing material applied thereto.

FIG. 2 is a schematic diagram showing a state in which a sizing board test piece on which a sealing material is applied is subjected to a 30% tensile deformation.

FIG. 3 is a schematic side view showing a state in which 10 ° torsional deformation is applied to a sizing board test piece on which a sealing material is applied.

[Explanation of symbols]

 1 Sizing board (test piece) 2 Sealing material 3 Spacer

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) C09K 3/10 C08L 71/02 E04B 1/682

Claims (1)

(57) [Claims] 1. A sealing material composition for a sizing board comprising a reactive silicon group-containing polyoxyalkylene polymer having a heat compression recovery ratio of 10% or less of a cured product.