JPH0457695B2 - - 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 that provides a rubber-like cured product with excellent weather resistance, adhesive properties, and high elongation, 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 locations that are relatively hot, such as joints in 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, 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 sealant compositions that use the above-mentioned polymer as a base polymer, and if you try to forcefully obtain a high elongation rate by adding a large amount of plasticizer, the tear strength will decrease significantly. There are also problems in that adhesiveness remains on the surface of the cured product, making it 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 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 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.
alkyl group, A is a monovalent aromatic group having a phenolic hydroxyl group, a is a number from 1 to 3, m is 10
~500, n represents a number of 1 or more. ), and has a molecular weight of 500 to 50,000, a polyether whose molecular chain ends are blocked with a hydrolyzable silyl group, 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: A-NH ₂ (wherein A represents a monovalent aromatic group having a phenyl hydroxyl group) aromatic amine 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 , R ⁴ , R ⁵ , R ⁶ , A, a, m
and n are as described above. ), the molecular weight of which is 500 to 50,000, and whose molecular chain ends are blocked with hydrolyzable silyl groups. 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 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, because raw materials are easy to obtain and polymerize, and the polymerization degree is high. 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 which provides practical workability. 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 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, A is

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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 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.) General formula of polyoxyalkylene (B) blocked with an epoxy group at the end of the molecular chain; A-NH ₂ (In the formula, A is as described above) ) and (C) the 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 the product obtained by adding epichloropidrine to polyoxyethylene or polyoxypropylene, both ends of which are blocked with hydroxyl groups, in the presence of a basic catalyst, etc. . 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 is possible to obtain a sealing material that has excellent heat resistance and weather resistance, exhibits adhesive properties without priming the surface to which it is adhered, and has a high elongation rate. [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,

Add 6 moles of [formula] and methanol in an amount equivalent to 10% of polyoxypropylene,
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, primary amines, and secondary amines in the sample was determined using potentiometric titration, and the peak due to protons of epoxide methylene (tetra (2.67 ppm based on methylsilane) and measured the viscosity at 25°C.
24 hours after the start of heating and stirring, the titration of epoxy groups and primary amines and secondary amines decreased by almost the theoretical amount, and at the same time the peak due to protons of epoxide methylene disappeared, and before the start of heating and stirring, the titration amount was 90 cSt. As the hot viscosity reached 1300cSt, 2.2 mol of was added, and heating and stirring was continued under the same conditions.
After adding the above silane, a portion was extracted at 4-hour intervals, and the total amount of epoxy groups, primary amines, and secondary amines in the sample was determined using potentiometric titration, and protons of epoxide methylene were determined using NMR. 16 hours after the addition of the silane, all of them almost disappeared, so heating and stirring was stopped and methanol was distilled off. A pale brown viscous liquid (polyether whose molecular chain ends were blocked with hydrolyzable silyl groups represented by the following formula, P-1) with a measured number average molecular weight of 6000 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,

Ethanol 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, primary amines, and secondary amines in the sample was determined using potentiometric titration.
The proton peak of epoxide methylene was observed by NMR, and the viscosity at 25°C was measured. 16 hours after the start of heating and stirring, the titration of epoxy groups and primary amines and secondary amines decreased by almost the theoretical amount, and at the same time the peak due to protons of epoxide methylene disappeared, and before the start of heating and stirring, the titration amount was 230 cSt. As the hot viscosity reached 3900cSt, 2.2 mol of was added, and heating and stirring was continued under the same conditions.
After adding the above silane, a portion was extracted at 4-hour intervals, and the total amount of epoxy groups, primary amines, and secondary amines in the sample was determined using potentiometric titration, and protons of epoxide methylene were determined using NMR. When we observed the peaks caused by silane, they almost disappeared 12 hours after the addition of the silane, so we stopped heating and stirring and distilled off the ethanol. A light brown viscous liquid (polyether P-2 whose molecular chain ends were blocked with hydrolyzable silyl groups represented by the following formula) with a measured number average molecular weight of 10,000 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, primary amines, and secondary amines in the sample was determined using potentiometric titration.
The proton peak of epoxide methylene was observed by NMR, and the viscosity at 25°C was measured. 16 hours after the start of heating and stirring, the titration of epoxy groups and primary amines and secondary amines decreased by almost the theoretical amount, and at the same time the peak due to protons of epoxide methylene disappeared, and before the start of heating and stirring, the titration amount was 380 cSt. As the hot viscosity reached 4900cSt, 2.2 mol of was added and heating and stirring was continued under the same conditions.
After adding the above silane, a portion was extracted at 4-hour intervals, and the total amount of epoxy groups, primary amines, and secondary amines in the sample was determined using potentiometric titration, and protons of epoxide methylene were determined using NMR. When we observed the peaks caused by silane, they almost disappeared 12 hours after the addition of the silane, so we stopped heating and stirring and distilled off the methanol. A pale brown viscous liquid (polyether P-3 whose molecular chain ends were blocked with hydrolyzable silyl groups represented by the following formula) with a measured number average molecular weight of 9000 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 approximately 2 mm thick and cured at room temperature for 14 days, 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 state 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 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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[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 A polyphenylene ether resin and b (1) a polyfunctional maleimide represented by the following general formula (2) or (2) a polyfunctional cyanate ester represented by the following general formula (4) as essential components. A curable resin composition prepared by blending an epoxy compound containing two or more epoxy groups in the c molecule in an amount of 0.1 to 50% by weight of the total resin composition. General formula (2): General formula (4): R ₂ -(O-C≡N)n...(4) (R ₁ in formula (2) is an aromatic or aliphatic polyvalent organic, X ₁ , X ₂ is a hydrogen atom or a lower alkyl group, k represents an integer of 2 to 10, and
R ₂ in formula (4) is a polyvalent organic group having 10 or less aromatic benzene rings, and the cyanate ester group is
It is directly bonded to the aromatic ring of _R2 , and n represents an integer of 2 to 10. )

Claims (1)

Polyether according to claim 1. 6. The polyether according to claim 1, wherein A is a substituted phenyl group substituted with at least one phenolic hydroxyl group and with or without other substituents. 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
Indicates a number of ~500. ) Polyoxyalkylene (B) whose molecular chain terminal is blocked with an epoxy group; General formula: A-NH ₂ (wherein A represents a monovalent aromatic group having a phenyl hydroxyl group) aromatic amine 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.
alkyl group, A is a monovalent aromatic group having a phenolic hydroxyl group, a is a number from 1 to 3, m is 10
~500, n represents a number of 1 or more. ) 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.