JPH0257824B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a composition suitable as a sealant composition that can be cured at room temperature into a rubber-like elastic body when exposed to moisture, and in particular has excellent heat resistance and weather resistance, and has adhesive properties. , relates to a room temperature curable composition that provides a rubber-like cured product with a high elongation rate. [Technical background of the invention and its problems] Polymers having hydrolyzable silicon functional groups and whose main chain is polyether are known (Japanese Patent Application Laid-Open No. 1983-1999).
156599, etc.). Room-temperature curable compositions based on this polymer have recently begun to be used as sealing materials for joints in buildings, joints in transportation machines, etc. (Japanese Unexamined Patent Publication No. 73998/1983, etc.). However, this type of composition has poor heat resistance and weather resistance, so it can be used in joints of external walls of buildings where weather resistance is required.
There is a problem in that it is not suitable for use in places where the temperature is relatively high, such as parts of joints in transportation machines. Furthermore, since this type of composition does not inherently have adhesive properties, it is necessary to apply a primer treatment to the surface to which it is adhered before applying the sealant. Furthermore, especially in architectural applications, a sealing material with as high an elongation rate as possible is desired in order to withstand fluctuations in joint width due to seasons and temperature differences between day and night. However, there is a limit to the elongation rate that can be obtained with the above-mentioned compositions, and if you try to forcibly obtain a high elongation rate by adding a large amount of plasticizer, the tear strength will decrease significantly or the surface of the cured product will become sticky. There is a problem in that it remains unsuitable for use as a sealant. [Object of the Invention] The present invention is intended to solve these problems, and provides a room-temperature curable rubber-like cured product that has excellent heat resistance and weather resistance, has adhesive properties, and has a high elongation rate. The purpose is to provide a composition. [Structure of the invention] That is, the present invention comprises (A) general formula; (In the formula, R ¹ , R ² , R ³ and R ⁴ are divalent hydrocarbon groups, R ⁵ is a monovalent hydrocarbon group, X is a hydrolyzable group, and A is a monovalent hydrocarbon group having a phenolic hydroxyl group. aromatic group, a represents a number of 1 to 3, m is 10 to
The number 500, n indicates a number of 1 or more. ) 100 parts by weight of a polyether whose molecular chain ends are blocked with a hydrolyzable silyl group (B) 3 to 300 parts by weight of an inorganic filler (C) 0.001 to 20 parts by weight of a curing catalyst The present invention relates to a room temperature curable composition. (A) General formula used in the present invention; (In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , X, A, a, m
and n are as described above. ) In the polyether represented by R ¹ O, the oxyalkylene unit represented by R 1 O is preferably an oxyethylene unit, an oxypropylene unit, or a combination system of oxyethylene units and oxypropylene units, which is easy to obtain raw materials and polymerize, and has a high degree of polymerization. However, oxypropylene units are particularly preferred because they can easily maintain a liquid state. The degree of polymerization m of oxyalkylene units is
It is selected in the range of 10 to 500, and if m is smaller than 10, it becomes difficult to obtain a rubber-like cured product with a sufficient elongation rate and a viscosity below which practical workability is obtained. On the other hand, if m is larger than 500, the heat resistance and weather resistance, which are the characteristics of the present invention, will decrease. The divalent hydrocarbon group of R ² is a methylene group,
Ethylene group, trimethylene group, tetramethylene group, phenylene group, cyclohexylene group and

Examples include groups represented by [Formula]. Among these groups, a methylene group is preferred from the viewpoint of easy availability of raw materials. Examples of R ³ and R ⁴ include those similar to R ² , but R ³ is preferably a methylene group from the viewpoint of easy availability of raw materials. Further, R ⁴ is preferably a trimethylene group or a tetramethylene group from the viewpoint of ease of synthesis and availability of raw materials, and particularly preferably a trimethylene group. The monovalent hydrocarbon group of R ⁵ is a methyl group, an ethyl group,
Alkyl groups such as propyl groups; aryl groups such as phenyl groups; aralkyl groups such as β-phenylethyl groups and β-phenylpropyl groups; however, from the viewpoint of ease of synthesis and raw material availability, methyl groups or phenyl groups is preferred, and methyl group is particularly preferred. The hydrolyzable group of
Examples include dialkylaminoxy groups, ketoxime groups, and alkenoxy groups, but methoxy groups, ethoxy groups, propoxy groups, and isopropoxy , alkoxy groups having 1 to 6 carbon atoms such as hexyloxy groups, and 2-methoxyethoxy groups are suitable, and methoxy groups and ethoxy groups are preferred from the viewpoint of high hydrolyzability (curing reactivity of the composition). , methoxy group is particularly preferred. The number a of hydrolyzable groups is selected within the range of 1 to 3, but it is preferable that a is 2 in order to obtain a composition that provides a rubber-like cured product with a high elongation rate. A is a monovalent aromatic group having a phenolic hydroxyl group, and since the raw material exhibits high reactivity, it is necessary to have a phenolic hydroxyl group. As a specific example of A,

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[Formula] etc. Among these, at least one
It is preferably a substituted phenyl group substituted with 2 phenolic hydroxyl groups and with or without other substituents. Further, n is a number of 1 or more, and may be 1, but it is preferably selected so that the molecular weight of the polyether which is the component (A) of the present invention is in the range of 500 to 50,000. When the composition of the present invention is used as a sealant, if the molecular weight is less than 500, the elongation of the cured elastic body will not reach the required value as a sealant, and if it is more than 50,000, the viscosity will be high. Workability deteriorates over time. For example, the polyether (A) used in the present invention has the general formula (); (In the formula, R ₁ , R ₂ and m are as described above.) General formula: A-NH ₂ (In the formula, A is as described above) Aromatic amine represented by ) and () general formula; (In the formula, R ³ , R ⁴ , R ⁵ , . A typical example of () is one obtained by adding epichlorohydrin to polyoxyethylene or polyoxypropylene, both ends of which are blocked with hydroxyl groups, in the presence of a basic catalyst or the like. () Specific examples of ingredients include:

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〔Effect of the invention〕

The composition of the present invention has excellent heat resistance and weather resistance, has adhesive properties, and forms a rubber-like cured product with a high elongation rate, so it is used for joint seals of buildings and joints of transportation machines. Suitable as a sealant. [Example] The present invention will be explained below with reference to Examples. In addition, in the synthesis examples, examples, and comparative examples, all parts are parts by weight.
% indicates weight %. Synthesis Example 1 For 10 epoxy equivalents of glycidyl group-end-blocked polyoxypropylene with an average degree of polymerization of 15, a molecular weight of about 1000, and a viscosity of 270 cst at 25°C,

Methanol in an amount corresponding to 6 mol of [Formula] and 10% of polyoxypropylene was added, and heating and stirring was started at 60°C under a nitrogen atmosphere. A portion of the sample was extracted at 4-hour intervals from the start of heating and stirring, and the total amount of epoxy groups and primary amines in the sample was determined using potentiometric titration, and the peak due to protons of epoxide methylene was measured using NMR (based on tetramethylsilane). 2.67 ppm) and measured the viscosity at 25°C. 24 hours after starting heating and stirring
After some time, the titration of the epoxy group and the primary amine decreased by almost the theoretical amount, and at the same time the peak due to the proton of epoxide methylene disappeared, and the viscosity, which was 90 cSt before the start of heating and stirring, reached 1300 cSt. 2.2 mol of was added, and heating and stirring was continued under the same conditions.
After adding the above silane, a portion was taken out at 4 hour intervals, and the total amount of epoxy groups and primary amines in the sample was determined using potentiometric titration and NMR.
When we observed peaks due to protons of epoxide methylene, all of them almost disappeared 16 hours after the addition of silane, so we stopped heating and stirring and distilled off the methanol. is 1.01,
A pale brown viscous liquid (polyether whose molecular chain terminals are blocked with hydrolyzable silyl groups represented by the following formula, P-1) having a number average molecular weight of 6000 as measured by GPC was obtained. Synthesis Example 2 For 10 epoxy equivalents of glycidyl group-end-blocked polyoxypropylene with an average degree of polymerization of 32, a molecular weight of approximately 2000, and a viscosity of 550 cSt at 25°C,

Ethanol in an amount corresponding to 6 moles of [Formula] and 10% of polyoxypropylene was added, and heating and stirring at 60°C under a nitrogen atmosphere was started. A portion was extracted at 4-hour intervals from the start of heating and stirring, and the total amount of epoxy groups and primary amines in the sample was determined using potentiometric titration, the peak due to protons of epoxide methylene was observed using NMR, and the viscosity at 25°C was determined. Measurements were made. 16 hours after the start of heating and stirring, the titration of the epoxy group and the primary amine decreased by almost the theoretical amount, and at the same time the peak due to protons of epoxide methylene disappeared, and the viscosity, which was 230cSt before the start of heating and stirring, decreased to 3900cSt. Because it reached 2.2 mol of was added, and heating and stirring was continued under the same conditions.
After adding the above silane, a portion was taken out at 4 hour intervals, and the total amount of epoxy groups and primary amines in the sample was determined using potentiometric titration and NMR.
When we observed peaks due to protons of epoxide methylene, all of them almost disappeared 12 hours after the addition of silane, so we stopped heating and stirring and distilled off the ethanol. is 1.01,
A light brown viscous liquid (polyether P-2 whose molecular chain ends are blocked with hydrolyzable silyl groups represented by the following formula) having a number average molecular weight of 10,000 as measured by GPC was obtained. Synthesis Example 3 For 6 epoxy equivalents of glycidyl group-terminated polyoxypropylene with an average degree of polymerization of 50, a molecular weight of approximately 3000, and a viscosity of 970 cSt at 25°C,

4 moles of [Formula] and methanol in an amount equivalent to 10% of polyoxypropylene were added, and heating and stirring was started at 60°C under a nitrogen atmosphere. A portion was extracted at 4-hour intervals from the start of heating and stirring, and the total amount of epoxy groups and primary amines in the sample was determined using potentiometric titration, the peak due to protons of epoxide methylene was observed using NMR, and the viscosity at 25°C was determined. Measurements were carried out. 16 hours after the start of heating and stirring, the epoxy group and the first
The titration amount with the grade amine decreased by almost the theoretical amount, and at the same time the peak due to protons of epoxide methylene disappeared, and the viscosity, which was 380 cSt at the start of heating and stirring, reached 4900 cSt. 2.2 mol of was added and heating and stirring was continued under the same conditions.
After adding the above silane, a portion was taken out at 4 hour intervals, and the total amount of epoxy groups and primary amines in the sample was determined using potentiometric titration and NMR.
When we observed peaks due to protons of epoxide methylene, all of them almost disappeared 12 hours after the addition of silane, so we stopped heating and stirring and distilled off methanol to find a viscosity of 22,000 cSt at 25°C and a specific gravity of 22,000 cSt at the same temperature. is 1.01,
A pale brown viscous liquid (polyether P-3 whose molecular chain ends are blocked with hydrolyzable silyl groups represented by the following formula) having a number average molecular weight of 9000 as measured by GPC was obtained. Synthesis Example 4 To 10 epoxy equivalents of the same glycidyl group-terminated polyoxypropylene used in Synthesis Example 2, 6 mol of p-aminophenol used in Synthesis Example 2 and 1 mol of polyoxypropylene were added.
% of phenol was added thereto, and the mixture was heated and stirred at 80° C. for 16 hours under a nitrogen atmosphere. Then, 2.2 mol of was added and heated and stirred under the same conditions for 16 hours to form a light brown viscous liquid (polyether whose molecular chain ends are blocked with hydrolyzable silyl groups represented by the following formula, P-4). ) was obtained. Synthesis Example 5 For 6 epoxy equivalents of the same glycidyl group-terminated polyoxypropylene used in Synthesis Example 3, 4 moles of p-aminophenol as used in Synthesis Example 2 and 2% of polyoxypropylene.
amount of tris(dimethylaminomethyl) equivalent to
Add phenol and incubate at 60℃ under nitrogen atmosphere for 16 hours.
The mixture was heated and stirred for hours. then 2.2 mol of was added and heated and stirred under the same conditions for 16 hours to obtain a pale brown viscous liquid (polyether whose molecular chain ends are blocked with hydrolyzable silyl groups represented by the following formula, P-5). I got it. Examples 1 to 5 Polyethers (P-1 to 5) whose molecular chain ends were blocked with hydrolyzable silyl groups obtained in Synthesis Examples 1 to 5
To 100 parts, the filler, inorganic pigment, and thixotropic agent shown in Table 1 were added and uniformly dispersed with a triple roll, and then the organic tin compound also shown in Table 1 was added and mixed. , Samples-1 to 5
I got it. These samples were cured into sheets with a thickness of about 2 mm, cured at room temperature for 14 days, and then punched into JIS No. 2 dumbbells and subjected to a tensile test. Next, the dumbbell-shaped sample piece obtained in the same manner was placed in a 150°C dryer and a weather meter, and after applying the deterioration conditions (heating and ultraviolet irradiation) for the period shown in Table 1, the condition of the sample piece was observed. A tensile test was conducted.
These results are also shown in Table 1. Comparative example 1 Molecular weight approximately 8000, as a terminal group

Fillers, inorganic pigments, and thixotropic properties shown in Table 1 were added to 100 parts of polyoxypropylene having the formula and uniformly dispersed with a triple roll.
Similarly, the organic tin compounds shown in Table 1 were added and mixed to obtain Sample-6. Example 1 using sample-6
The same test as in 5 was conducted. The results are also shown in Table 1. Examples 6-10 Same samples-1-1 as those prepared in Examples 1-5
A shear adhesion test specimen shown in FIG. 1 was prepared using No. 5. After curing the prepared test specimens at room temperature for 28 days, a tensile test was conducted. The results are shown in Table 2. Comparative Example 2 Using the same sample 6 as prepared in Comparative Example 1, a shear adhesion test specimen shown in FIG. 1 was prepared. Tests similar to Examples 6 to 10 were conducted using this test specimen. The results are also shown in Table 2.

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【table】 [Brief explanation of drawings]

FIG. 1 shows a perspective view of a specimen subjected to a shear adhesion test. The unit in the figure is mm. 1... Sample, 2... Adherent (glass, aluminum or PVC steel plate).

Claims (1)

[Claims] 1 (A) General formula; (In the formula, R ¹ , R ² , R ³ and R ⁴ are divalent hydrocarbon groups, R ⁵ is a monovalent hydrocarbon group, X is a hydrolyzable group, and A is a monovalent hydrocarbon group having a phenolic hydroxyl group. aromatic group, a represents a number of 1 to 3, m is 10 to
The number 500, n indicates a number of 1 or more. ) 100 parts by weight of a polyether whose molecular chain ends are blocked with a hydrolyzable silyl group (B) 3 to 300 parts by weight of an inorganic filler (C) 0.001 to 20 parts by weight of a curing catalyst A room temperature curable composition. 2 The oxyalkylene unit R ¹ O is an oxyethylene unit, an oxypropylene unit, or a combination system of an oxyethylene unit and an oxypropylene unit,
A composition according to claim 1. 3. The composition according to claim 1, wherein the oxyalkylene unit R ¹ O is an oxypropylene unit. 4. The composition of claim 1, wherein A is a substituted phenyl group substituted with at least one phenolic hydroxyl group, with or without other substituents. 5. The composition according to claim 1, wherein X is an alkoxy group having 1 to 6 carbon atoms. 6. The composition of claim 1, wherein a is 2.