JPS63125524A - Polyether having terminals blocked with hydrolyzable silyl group - Google Patents

Abstract

PURPOSE:To form a polyether useful as a base polymer for a room temperature- curable composition which can give a rubber-like cured product of a high elongation and excellent adhesiveness, by reacting a polyester having terminals blocked with epoxy groups with an imino group-containing heterocyclic compound and an organosilicon compound. CONSTITUTION:A polyether (A) having terminals blocked with epoxy groups, represented by formula I (wherein R<1> and R<2> are each a bivalent hydrocarbon group and m is a number of 10-500), is reacted with a heterocyclic compound (B) having two imino groups bonded to different carbon atoms in the molecule and an organosilicon compound (C) having epoxy and hydrolyzable groups, represented by formula II (wherein R<3> and R<4> are each a bivalent hydrocarbon group, R<5> is a monovalent hydrocarbon group, R<6> is a 1-6C alkyl group and a is a number of 1-3). In this way, a polyether having terminals blocked with hydrolyzable silyl groups and a mo.wt. of 1,000-50,000, represented by formula III (wherein X is a residue of the compound (B), n is a number >=1, a, m and R<1>-R<6> are as defined above), can be obtained.

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 hydrolyzable silyl groups, which can be cured at room temperature into a rubber-like elastic body when exposed to moisture. In particular, the present invention relates to a polyether useful as a base polymer for a room-temperature curable composition that has excellent adhesive properties and 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 having a polyether main chain are known (Japanese Patent Laid-Open No. 50-156599).
However, since this type of polymer does not inherently have adhesive properties, it is necessary to pre-treat the surface to which it is adhered by applying a brimer, or add a silane coupling agent to the composition. It is necessary to add adhesive properties such as the following. However, the addition of a silane coupling agent poses a problem in that the elongation rate of the rubber-like elastic body after curing decreases, making it brittle, in exchange for the acquisition of adhesive properties.

[Purpose of the invention]

The present invention is intended to solve these problems, and provides a polyether useful as a base polymer for a room-temperature curable composition that provides a rubber-like cured product with excellent adhesive properties and high elongation. With the goal.

[Structure of the invention]

That is, the present invention has the following formula: (8) General formula;
Indicates the number of 00. ), (B) a heterocyclic compound having two imino groups bonded to two different carbon atoms in the molecule, and (C) the general formula ; (In the formula, R3 and R4 are divalent hydrocarbon groups, R8 is 1
a valent hydrocarbon group, R6 is an alkyl group having 1 to 6 carbon atoms, a
represents a number from 1 to 3. ) with the general formula I53-a (R60)-5i-R'-0-R:1-CI(CHz
nN=X=N-CHzC)l-R"-04R'0)i0
H0H R5 Go Hatake” -R2-C! (CHg-)r-N=X=N-CIlzC
i-R3-0-R'-5i (OR')-01101+ (wherein, X is the residue of the compound (B), n is a number of 1 or more,
a,! I+ and R1-R6 are as described above), and has a molecular weight of 1,000 to 50,000, and relates to a polyether whose molecular chain terminals are blocked with a hydrolyzable silyl group.

In the polyether (A), the oxyalkylene unit represented by R'0 is preferably an oxyethylene unit, an oxypropylene unit, or a combination system of oxyethylene units and oxypropylene units, which facilitates raw material acquisition and polymerization, 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 the oxyalkylene unit is selected from the range of 10 to 500. When m is less than 10, it becomes difficult to obtain a polyether that provides a rubber-like cured product with a viscosity that provides practical workability and a sufficient elongation rate. 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 for R2 includes a methylene group, an ethylene group, a trimethylene group, and a tetramethylene group. Among these groups, a methylene group is preferred from the viewpoint of ease of handling raw materials.

Typical examples of these (A) include those obtained by condensing epichlorohydrin with polyoxyethylene or polyoxypropylene, both ends of which are blocked with hydroxyl groups, in the presence of a basic catalyst.

The compound (B) is a heterocyclic compound having an imino group that reacts with the epoxy group of (A) and (C). It is necessary that the compound is a heterocyclic compound having two imino groups bonded to two carbon atoms in the molecule. these(
As B), the following are exemplified because they are easy to synthesize and obtain. That is, we particularly recommend piperazine because of its ease of raw material availability.

As R3 and R4 of the organosilicon compound (C),
Although the same ones as R2 are exemplified, R3 is preferably a methylene group from the viewpoint of easy availability of raw materials. Also, R
4 is preferably an ethylene group, a trimethylene group, or a tetramethylene group from the viewpoint of ease of synthesis and manual handling of raw materials, and a trimethylene group is particularly preferable.

The monovalent hydrocarbon group of R5 is an alkyl group, an IJ-al group,
It can be selected from aralkyl groups, etc., but methyl groups are recommended because of ease of synthesis and availability of raw materials.

The alkyl group having 1 to 6 carbon atoms in R& is an alkoxy group bonded to a silicon atom represented by R69-, and is preferably a methyl group or an ethyl group because it needs to have high hydrolyzability. Particularly preferred are groups. The number a of hydrolyzable groups is selected in the range of 1 to 3,
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 is preferably 2.

Specific examples of (C) include β-glycidoxyethyltrimethoxysilane, T-glycidoxypropyltrimethoxysilane, β-glycidoxyethyltriethoxysilane, and T-glycidoxypropyltriethoxysilane. silane,
Methyl (β-glycidoxyethyl) dimethoxysilane,
Methyl (T-glycidoxypropyl) dimethoxysilane, methyl (β-glycidoxyethyl) jetoxysilane, methyl (γ~glycidoxypropyl) jetoxysilane, phenyl (β-glycidoxyethyl) dimethoxysilane, Examples include phenyl (γ-glycidoxypropyl) dimethoxysilane, dimethyl (β-glycidoxyethyl) methoxysilane, and dimethyl (T-glycidoxypropyl) methoxysilane.

The polyether of the present invention is obtained by reacting the epoxy groups (A) and (C) described above with the imino group (B).

The reactions of (A), (B) and (C) are preferably carried out at a temperature higher than the ambient temperature, for example 50 to 150°C. In this case, compounds such as methanol, ethanol, phenol, salicylic acid, tris(dimethylaminomethyl)phenol, benzylmethylamine, tributylamine and 2-methylimidazole are preferably used as reaction accelerators. Methanol is one of the preferred ones. Although it is not necessary to use a solvent when carrying out this reaction, a hydrocarbon-based, ether-based, or ester-based solvent may be used.

The blending amounts of (A), (B) and (C) are theoretically in a molar ratio of (8):(B):(C)=p:(p+1):
2 (in the formula, p represents a natural number starting from 1).

However, in reality, it is acceptable even if CB) and (C) are used in amounts slightly exceeding the theoretical amounts.

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 1,000 to 50,00
It is necessary to select a value within the range of 0.

When the polyether of the present invention is used as a base polymer for a sealant, if the molecular weight is less than 1,000, the elongation of the cured elastic body will not reach the level required for a sealant; When it is larger than 000, the viscosity becomes high and workability decreases.

〔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 a high elongation rate and can exhibit adhesive properties without priming the surface to which it is applied.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

In the Examples, Comparative Examples, and Reference Side, all parts are by weight, and % is by weight.

Example 1 5 moles of glycidyl group-end-blocked polyoxypropylene with an average degree of polymerization of 15 and a molecular weight of about 1.000.25°C and a viscosity of 270 cSt [corresponding to 6 moles per 10 (epoxy) and 10% of the polyoxypropylene of methanol was added, and heating stirring was started at 60° C. under a nitrogen atmosphere. A portion was taken out at 4 hour intervals from the start of heating and stirring, and N
MI? Peak due to proton of epoxide methylene (2.67 ppm based on tetramethylsilane)
, the total amount of epoxy groups and imino groups was determined by potentiometric titration, and the viscosity at 25°C was measured. 12 hours after the start of heating and stirring, the peak due to protons of epoxide methylene disappeared, and the viscosity of the mixture, which was 80cSt before starting heating and stirring, decreased to 1.500cS.
Since S t has been reached, CI (3 CHzCH-CHz-0-(Colth-3i (OC
2.2 mol of methyl(γ-glycidoxypropyl)dimethoxysilane represented by R□)2 was added, and heating and stirring was continued under the same conditions. A portion of the reaction mixture was sampled at 4-hour intervals after the addition of the silane, and the total amount of epoxy groups and imino groups in the sample was quantitatively investigated using potentiometric titration. Afterwards, since no imino groups were detected, heating and stirring were terminated, and methanol was distilled off. The obtained reaction product is
The disappearance of the peak due to protons of epoxide methylene by NMR was observed, and the viscosity at 25°C was 15.0O.
OcSt is a pale yellow viscous liquid with a specific gravity of 1.01 at the same temperature and a number average molecular weight of 6,000 as measured by GPC, and the molecular chain terminal is blocked with a hydrolyzable silyl group represented by the following formula. It was confirmed that it was a polyether (P-1).

Of(011 ■ -4CIl□h-5i (QC)+3) zExample 2 Glycidyl group-end-blocked polyoxy with average degree of polymerization of 32 and molecular weight of approximately 2,000.25°C viscosity of 550 cSt. 5 moles of propylene [10 (epoxy) 6 moles of cyclopentane and 1 mole of polyoxypropylene
Add star ethanol equivalent to 0%, under nitrogen atmosphere,
Heating and stirring was started at 80°C.

A portion was taken out at 2 hour intervals from the start of heating and stirring and subjected to NMR analysis.
Observation of the proton peak of epoxide methylene was carried out, the total amount of epoxy groups and imino groups was determined by potentiometric titration, and the viscosity at 25°C was measured. 6 hours after the start of heating and stirring, the titration amount 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 210 cSt before the start of heating and stirring, reached 4,000 cSt. Heating and stirring was continued under the same conditions. After adding the above silane, a portion was taken out at 2 hour intervals, and the total amount of epoxy groups and imino groups was determined using potentiometric titration, and the peak due to protons of epoxide methylene was observed using NMR. After 8 hours, all of them had almost disappeared, so heating and stirring was stopped, and the ethanol was distilled off, resulting in a viscosity of 26,000 cSt at 25°C.
, a pale yellow viscous liquid with a specific gravity of 1.01 at the same temperature and a number average molecular weight of 11,000 as measured by GPC (polymer whose molecular chain ends are blocked with hydrolyzable silyl groups represented by the following formula) Ether, P-2) was obtained.

CH.

-CHzCllCH1-0+CHth-Si (OCH
zCH*) zH Example 3 Average degree of polymerization 50, molecular weight approximately 3,000. viscosity at 25°C 970 cSt 3 moles of glycidyl group-end-blocked polyoxypropylene [6 (epoxy) equivalent] 4 moles of phenazine and polyoxypropylene Methanol in an amount equivalent to 10% of propylene was added, and heating and stirring was started at 60° C. under a nitrogen atmosphere. A portion was taken out at 4 hour intervals from the start of heating and stirring, and the peak due to protons of epoxide methylene was observed by NMR, the total amount of epoxy groups and imino groups was determined by potentiometric titration, and the viscosity at 25°C was measured. 12 hours after the start of heating and stirring,
At the same time as the titration of epoxy groups and imino groups decreased by almost the theoretical amount, the peak due to protons of epoxide methylene disappeared, and the viscosity, which was 360 cSt before the start of heating and stirring, reached 5,000 cSt, under the same conditions. Heating and stirring was continued. After adding the above silane, a portion was taken out at 4 hour intervals, and the total amount of epoxy groups and imino groups in the sample was determined using potentiometric titration, and the peak due to protons of epoxide methylene was observed using NMR. 16 hours after the addition of the silane, all of them had almost disappeared, so heating and stirring was stopped, methanol was distilled off, and the viscosity at 25°C was 22.
．． 0OOcSt, specific gravity at the same temperature is 1.01, G
A pale yellow viscous liquid (polyether whose molecular chain ends were blocked with a hydrolyzable silyl group represented by the following formula, P-3) having a number average molecular weight of 10,000 as measured by PC was obtained.

-(ni1lzh-5i (OCH3)2 Reference Examples 1 to 3 For 100 parts of each polyether (P-1 to 3) whose molecular chain ends are blocked with a hydrolyzable silyl group obtained in Examples 1 to 3 Then, fillers, inorganic pigments, and thixotropic property imparting agents shown in Table 1 were added and uniformly dispersed with a triple roll, and then the organic tin compounds shown in Table 1 were added and mixed to prepare the sample. -1 to -3 were adjusted respectively.Using each of these samples, they were cured into sheets of approximately 2m111 thickness and cured for 14 days at room temperature, and then punched into JIS No. 2 dumbbells and subjected to a tensile test.These results were The results are shown in Table 1. Using these samples 1 to 3, shear adhesion test specimens shown in FIG. 1 were prepared.

The test specimen was cured at room temperature for 28 days and then subjected to a tensile test. The results are also shown in Table 1.

Comparative example 1 Molecular weight approximately 8,000, as a terminal group CH.

(CHsO)zsi-C)lzctlzcIlz-0
- To 100 parts of polyoxypropylene having a polyoxypropylene of The compound was added and mixed to obtain Sample-4. Tests similar to Reference Examples 1 to 3 were conducted using Sample-4. The results are also shown in Table 1.

Comparative Example 2 A silane coupling agent shown in Table 1 was added as an adhesion imparting agent to Sample-4 prepared in Comparative Example 1 to obtain Sample-5. A test similar to that of the reference example was conducted using this sample, and the results are also shown in Table 1.

As shown by the above results, the polyether of the present invention is useful as a base polymer for room-temperature curable compositions, and in particular, the cured product of the composition has a high elongation rate and can be used even in systems that do not contain an adhesion promoter. It is clear that it has high adhesive properties.

[Brief explanation of the drawing]

FIG. 1 shows a perspective view of a specimen subjected to a shear adhesion test. Note that the unit in the figure is mm. 1... Sample

Claims (1)

[Claims] 1 (A) General formula; ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R^1 and R^2 are divalent hydrocarbon groups, m is 10
Indicates a number of ~500. ), (B) a heterocyclic compound having two imino groups bonded to two different carbon atoms in the molecule, and (C) the general formula ; ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (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 an organosilicon compound having a hydrolyzable group; ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, X is the compound of (B) residues, n is a number greater than or equal to 1,
a, m, and R^1 to R^6 are as described above), and has a molecular weight of 1,000 to 50,000, and the molecular chain terminals are blocked with a hydrolyzable silyl group. 2 Component (B) is piperazine, 2,5-dimethylpiperazine, 1,4-diiminocyclopentane, perhydrophenazine, perhydropyrimidine, perhydro-1,3
, 5-oxadiazine, and perhydro-1,3,5-thiadiazine. 3. The composition according to claim 1, wherein component (B) is piperazine.