JPH032450B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a polyether whose molecular chain ends are blocked with a hydrolyzable silyl group, which can be cured at room temperature into a rubber-like elastic body when exposed to moisture, and a method for producing the same, in particular a polyether having a heat-resistant property. The present invention relates to a polyether useful as a base polymer for a room-temperature curable composition, which provides a rubber-like cured product having excellent weather resistance, adhesive properties, and no sticky residue on the surface, and a method for producing the same. [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 polymer has poor heat resistance and weather resistance, so
There is a problem in that it is not suitable for use in places where the temperature is relatively high, such as joints in the exterior walls of buildings that require weather resistance or parts of joints in transportation machines. Furthermore, since this type of polymer 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, since adhesiveness remains on the surface of the cured product,
There is a problem in that dust tends to adhere to the sealant. [Object of the Invention] The present invention is intended to solve these problems, and aims to provide a rubber-like cured product that has excellent heat resistance and weather resistance, has adhesive properties, and does not leave any sticky residue on the surface. An object of the present invention is to provide a polyether whose molecular chain ends are blocked with a hydrolyzable silyl group, which is useful as a base polymer for a room-temperature curable composition, and a method for producing the same. [Structure of the invention] That is, the present invention has the 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, and R ⁶ has 1 to 6 carbon atoms.
(A is a substituted or unsubstituted divalent aromatic group, a is a number of 1 to 3, m is a number of 10 to 500, and n is a number of 1 or more). A polyether whose molecular chain ends are blocked with a hydrolyzable silyl group, and whose molecular weight is 500 to 50,000, and (A) general formula; (In the formula, R ¹ and R ² are divalent hydrocarbon groups, m is 10
Indicates a number of ~500. ) Polyoxyalkylene (B) whose molecular chain terminal is blocked with an epoxy group General formula; H ₂ N-A-NH ₂ (wherein A represents a substituted or unsubstituted divalent aromatic group) ) and (C) general formula; (In the formula, R ³ and R ⁴ are divalent hydrocarbon groups, R ⁵
represents a monovalent hydrocarbon group, R ⁶ represents an alkyl group having 1 to 6 carbon atoms, and a represents a number of 1 to 3. ) A general formula characterized by reacting an epoxy group represented by the following with an organosilicon compound having a hydrolyzable group; (In the formula, R ¹ , R ² , R ³ and R ⁴ are divalent hydrocarbon groups, R ⁵ is a monovalent carbon hydrogen group, and R ⁶ has 1 to 6 carbon atoms.
A is a substituted or unsubstituted divalent aromatic group, a is a number from 1 to 3, m is a number from 10 to 500, and n is a number from 1 to 500. ) The present invention relates to a method for producing a polyether having a molecular weight of 500 to 50,000 and whose molecular chain ends are blocked with a hydrolyzable silyl group. General formula of the present invention; (In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , A, a, m
and n 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
If m is selected within the range of 10 to 500, it will be difficult to obtain a polyether that provides a rubber-like cured product with a sufficient elongation rate at a viscosity below that at 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 group and β-phenylpropyl group, etc. is preferred, and methyl group is particularly preferred. The alkyl group having 1 to 6 carbon atoms in R ⁶ is
Since the alkoxy group bonded to the silicon atom represented by R ⁶ O- has high hydrolyzability, a methyl group or an ethyl group is preferred, and a methyl group is particularly preferred. The number a of hydrolyzable groups is selected in the range of 1 to 3, but in order to obtain a polyether suitable as a base polymer for a composition that provides a rubber-like cured product with a high elongation rate, a must be 2. is preferred. A is a substituted or unsubstituted divalent aromatic group, and the raw materials are easily available, the compatibility with other raw materials is good, and the room-temperature curable composition using the polyether of the present invention has good construction workability,
And since it has a sufficient elongation rate after curing, a phenylene group, a bisphenylene group or a general formula;-
A group represented by R ⁷ -Q-R ⁸ - (in the formula, R ⁷ , R ⁸ and Q are as described above) is preferable. As a specific example of A,

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[Formula] etc. Further, n is a number of 1 or more, and may be 1, but if the molecular weight of the polyether of the present invention is 500 to 50,000
It is necessary to choose a range that is within the range of . When the polyether of the present invention is used as a base polymer for a sealant, if the molecular weight is less than 500, the elongation rate of the cured elastic body will not reach the elongation required for the sealant; Viscosity increases and workability decreases. The polyether of the present invention has, for example, (A) general formula; (In the formula, R ¹ , R ² and m are as described above.) Polyoxyalkylene (B) whose molecular chain terminal is blocked with an epoxy group General formula: H ₂ N-A-NH ₂ (In the formula , A is as described above.) An aromatic diamine compound represented by: and (C) general formula; (In the formula, R ³ , R ⁴ , R ⁵ , R ⁶ and a are as described above.) It can be synthesized by reacting an epoxy group represented by the formula with an organosilicon compound having a hydrolyzable group. can. A typical example of (A) 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 component (B) include:

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〔Effect of the invention〕

A sealing material can be obtained by adding a curing catalyst such as an organotin compound, a filler, and the like to the polyether of the present invention. By using the polyether of the present invention as a base polymer, it has excellent heat resistance and weather resistance, and exhibits adhesion without the need for primer treatment on the surface to be adhered.Also, since there is no residual surface tackiness, it is difficult to prevent dust from adhering to the surface. A sealing material that does not cause staining can be obtained. [Example] Hereinafter, the present invention will be explained in more detail with reference to Examples. In addition, in the examples, comparative examples, and reference examples,
All parts are by weight, and % is by weight. 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 at 25°C of 270 cSt,

Methanol in an amount corresponding to 6 moles of [Formula] and 10% of polyoxypropylene was 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.
Peak due to proton of epoxide methylene by NMR (based on tetramethylsilane)
2.67 ppm) and measured the viscosity at 25°C. 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 100cSt before the start of heating and stirring, decreased to 1800cSt. Because it reached

2.2 mol of [Formula] 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 the peak due to protons of epoxide methylene was observed using NMR. However, 12 hours after the addition of the silane, all of them had almost disappeared, so we ended the heating and stirring, and distilled off the methanol. A pale yellow viscous liquid with a molecular weight of 6500 (a polyether whose molecular chain ends are blocked with a hydrolyzable silyl group represented by the following formula, P-
1) was obtained. Example 2 For 10 epoxy equivalents of glycidyl group-end-blocked polyoxypropylene with an average degree of polymerization of 32, a molecular weight of about 2000, and a viscosity at 25°C of 550 cSt,

Methanol in an amount corresponding to 6 moles 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 NMR.
Observation of the proton peak of epoxide methylene and measurement of viscosity at 25°C were carried out. 16 hours after the start of heating and stirring, the titration amount 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 before the start of heating and stirring, the titration amount of the epoxy group and the primary amine decreased to 250 cSt.
As the viscosity reached 4200cSt, 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 methanol. is 1.01,
A pale yellow viscous liquid having a number average molecular weight of 11,000 as measured by GPC (polyether P-2 whose molecular chain ends are blocked with hydrolyzable silyl groups represented by the following formula) was obtained. Example 3 For 6 epoxy equivalents of glycidyl group-terminated polyoxypropylene with an average degree of polymerization of 50, a molecular weight of about 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 made. 18 hours after the start of heating and stirring, the appropriate amounts of epoxy groups and primary amines 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 400 cSt before heating and stirring, decreased.
As it reached 5200cSt,

2.2 mol of [Formula] 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 the peak due to protons of epoxide methylene was observed using NMR. However, 12 hours after the addition of the silane, all of them had almost disappeared, so we ended the heating and stirring, and distilled off the methanol. Pale yellow viscous liquid with a molecular weight of 9500 (polyether whose molecular chain ends are blocked with hydrolyzable silyl groups represented by the following formula, P-
3) was obtained. Reference Examples 1 to 3 Polyethers (P-1 to 3) whose molecular chain ends were blocked with hydrolyzable silyl groups obtained in Examples 1 to 3
To 100 parts, fillers, inorganic pigments, and thixotropic agents shown in Table 1 were added and dispersed uniformly with a triple roll, and then an organic tin compound also shown in Table 1 was added and mixed. , samples-1 to 3
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 the surface conditions were observed by finger touch and a tensile test was performed. Next, the dumbbell-shaped sample piece obtained in the same manner was placed in a 150°C dryer and a weatherometer, and after applying the deterioration conditions (heating and ultraviolet irradiation) for the period shown in Table 1, the state of the sample piece was evaluated. A tensile test was conducted. These results are also shown in Table 1. Comparative example 1 Molecular weight approximately 8000, as a terminal group For 100 parts of polyoxypropylene with
After adding the filler, inorganic pigment, and thixotropic agent shown in Table 1 and uniformly dispersing them with a triple roll, the organic tin compound also shown in Table 1 was added and mixed to obtain Sample-4. Ta. Tests similar to Reference Examples 1 to 3 were conducted using Sample-4. The results are also shown in Table 1. Reference Examples 4-6 Same samples 1-3 as those prepared in Reference Examples 1-3
Using this, a shear adhesion test specimen shown in FIG. 1 was prepared. After curing the created test specimen 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 4 as prepared in Comparative Example 1, a shear adhesion test specimen shown in FIG. 1 was prepared. Tests similar to Reference Examples 4 to 6 were conducted using this test specimen. The results are also shown in Table 2.

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【table】 [Brief explanation of the drawing]

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. 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, and R ⁶ has 1 to 6 carbon atoms.
A is a substituted or unsubstituted divalent aromatic group, a is a number from 1 to 3, m is a number from 10 to 500, and n is a number from 1 to 500. ) and has a molecular weight of 500 to 50,000, a polyether whose molecular chain ends are blocked with a hydrolyzable silyl group. 2. The polyether according to claim 1, wherein R ¹ is an ethylene group and/or a propylene group. 3. The polyether according to claim 2, wherein R ¹ is a propylene group. 4. The polyether according to claim 1, wherein R ² is a methylene group. 5. The polyether according to claim 1, wherein R ⁶ is a methyl group or an ethyl group. 6 A is substituted or unsubstituted phenylene group, biphenylene group or general formula; -R ⁷ -Q-R ⁸ - (wherein R ⁷ and R ⁸ are substituted or unsubstituted phenylene group, Q is alkylene group, - O-, -S-, _-SO2
- or -CO-. ) The polyether according to claim 1, which is a divalent aromatic group represented by: 7. The polyether according to claim 1, wherein a is 2. 8 (A) General formula; (In the formula, R ¹ and R ² are divalent hydrocarbon groups, m is 10
Showing a number of ~500. ) Polyoxyalkylene (B) whose molecular chain terminal is blocked with an epoxy group General formula; H ₂ N-A-NH ₂ (wherein A represents a substituted or unsubstituted divalent aromatic group) ) and (C) general formula; (In the formula, R ³ and R ⁴ are divalent hydrocarbon groups, R ⁵
represents a monovalent hydrocarbon group, R ⁶ represents an alkyl group having 1 to 6 carbon atoms, and a represents a number of 1 to 3. ) A general formula characterized by reacting an epoxy group represented by the following with an organosilicon compound having a hydrolyzable group; (In the formula, R ¹ , R ² , R ³ and R ⁴ are divalent hydrocarbon groups, R ⁵ is a monovalent hydrocarbon group, and R ⁶ has 1 to 6 carbon atoms.
A is a substituted or unsubstituted divalent aromatic group, a is a number from 1 to 3, m is a number from 10 to 500, and n is a number from 1 to 500. ) and has a molecular weight of 500 to 50,000, a method for producing a polyether whose molecular chain ends are blocked with a hydrolyzable silyl group.