JPS5810418B2 - Method for producing silicone-modified polyoxyalkylene polyether - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to one-component polyoxyalkylene polyethers, particularly molecular The present invention relates to a method for producing a silicone-modified polyoxyalkylene polyether having a silyl group or a siloxane bond containing an atom at the chain end.

Conventionally, as a method for producing a polyoxyalkylene polyether having a silyl group at the end of the molecular chain, for example, (1) a polyoxyalkylene polyether having an incyanate group at the end of the molecular chain and an alkoxy group such as 3-aminopropyltrimethoxysilane, By reacting silane,
Method for obtaining polyoxyalkylene polyether having an alkoxy group-containing organosilyl group at the end of the molecular chain (see Japanese Patent Publication No. 30711/1983), (2) Polyoxyalkylene polyether having an ether-type allylolefin group at the end of the molecular chain A polyoxyalkylene polyether having a hydrolyzable group or a halogen-containing organosilyl group at the end of the molecular chain is produced by adding an organosilane having a hydrogen atom bonded to a silicon atom and a hydrolyzable group or a halogen. How to get (
(see Japanese Patent Laid-Open No. 156599/1983), etc. are known.

However, the curing mechanism of the polymer obtained by the above method (1) is to form crosslinks through the reaction of the urethane bonds in the polymer with hydrogen atoms, so this polymer has a high viscosity. However, although the cured product obtained from this polymer has excellent mechanical strength, it has a low elongation rate, so if the adherend is brittle, it may be destroyed. Furthermore, if even a small amount of isocyanate groups remain in the polymer, the storage stability will be poor, and if the above reaction is not completed in advance, it will react with atmospheric moisture during curing. There is a disadvantage that the carbon dioxide gas that is sometimes generated causes a foaming phenomenon, which reduces the performance of the cured product.

On the other hand, the above method (2) does not have the same problems as the above method (1), but in this method, a transition metal belonging to Group 1 of the periodic table, such as a platinum compound, is contained as a reaction catalyst. It is essential to use a compound containing a mercapto group, an amino group, or a sulfur atom in the reaction system, as this catalyst may act as a catalyst poison. It has the disadvantage that the addition reaction does not proceed at all, and that side reactions such as dehydrogenation occur if water or alcohols are present in the reaction system.

Furthermore, in the addition reaction of high-molecular polymers such as this reaction, the reaction temperature must be kept at 80 to 120°C by heating, and when a high-molecular compound is used as a starting material, the double bond Rearrangement occurs in some parts, producing substituted unsaturated groups such as impropenyl groups or methallyl groups, and addition reactions do not proceed at all for such groups.
This has the disadvantage that the reaction rate decreases as a result.

The present invention relates to a method for producing a novel polyoxyalkylene polyether, which eliminates such disadvantages and drawbacks, and sometimes a silicone-modified polyoxyalkylene polyether having a group shown at the end of the molecular chain,
This method is characterized by subjecting a molecular chain bed to an addition reaction between a polyoxyalkylene polyether having a group represented by the formula % and an organosilicon compound represented by the general formula.

[In the formula, R1 represents a hydrogen atom or a monovalent hydrocarbon group, R2 and R5 represent a divalent hydrocarbon group, R3 represents an alkyl group, R4 represents a monovalent hydrocarbon group or a triorganosiloxy group, and m is 0 or 1. , a is 1.2 or 3.

] Next, the present invention will be explained in more detail.

First, the polyoxyalkylene polyether used as a starting material in the method of the present invention has a group represented by the above formula (ii) at the end of the molecular chain.

In this formula, R1 represents a hydrogen atom or a monovalent hydrocarbon group, preferably a monovalent hydrocarbon group having 1 to 20 carbon atoms, and examples of the monovalent hydrocarbon group include methyl group, ethyl group, propyl group, butyl group. Alkyl groups such as groups, cyclopentyl groups,
A cycloalkyl group such as a cyclohexyl group, an aryl group such as a phenyl group or a tolyl group, an aralkyl group such as a benzyl group, or a hydrogen atom of these groups partially contains a halogen atom such as a chlorine atom, a fluorine atom, or an organic group such as a cyan group. Examples include groups substituted with other groups.

R2 is a divalent hydrocarbon group, preferably having 1 to 20 carbon atoms
represents a divalent hydrocarbon group, including alkylene groups such as methylene group, ethylene group, propylene group, arylene group such as phenylene group, -C6H4, CH2, CH2-
Examples include alkalylene groups such as , and groups in which the hydrogen atoms of these groups are partially substituted with saturated-valent hydrocarbon groups.

m is as described above. This polyoxyalkylene polyether is not particularly limited except that it must have a group represented by the above formula (ii) at the end of its molecular chain; is essentially composed of repeating units represented by the formula % (where R6 represents a divalent hydrocarbon group, preferably a divalent hydrocarbon group having 1 to 4 carbon atoms), and has a molecular weight of 400 A value in the range of 15,000 to 15,000 is preferred.

Examples of the divalent hydrocarbon group represented by R6 include the following.

Note that the repeating structure of oxyalkylene represented by formula (iV) is not limited to only one type of R6, but may include different groups selected from the divalent hydrocarbon groups represented by R6 described above and an oxygen atom. For example, a polyoxyethylene polyoxypropylene structure may be used.

Next, the organosilicon compound used as a starting material together with the polyether in the present invention is represented by the above general formula (iii).

In the formula, R3 represents an alkyl group, and examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a cyclopentyl group, a cyclohexyl group, and the like.

Further, R4 represents a monovalent hydrocarbon group or a triorganosiloxy group, and examples of this monovalent hydrocarbon group include the same groups as the monovalent hydrocarbon group exemplified in R1 above, and a triorganosiloxy group. Examples include groups represented by the formula % (wherein R7 represents the same or different monovalent hydrocarbon group, preferably a monovalent hydrocarbon group having 1 to 18 carbon atoms), Specifically, this triorganosiloxy group includes a trimethylsiloxy group,
Examples include dimethylpropylsiloxy group, dimethylethylsiloxy group, dimethylphenylsiloxy group, and methylethylphenylsiloxy group.

R5 represents a divalent hydrocarbon group, and examples thereof include the same groups as those exemplified for R2 above.

Specific examples of the organosilicon compound represented by the general formula (iii) as described above include the following compounds.

(In the above formula, Me indicates a methyl group.) In the present invention, the above-mentioned partial hydrolyzate of alkoxysilane can also be used.

In the method of the present invention, a polysoxyalkylene polyether having a group represented by the above formula (i) at the end of the molecular chain is subjected to an addition reaction with an organosilicon compound represented by the above general formula (iii). However, examples of this reaction method include a method under irradiation with light and a method using various radical generators.

When carrying out the addition reaction under light irradiation, the temperature is -2
It is preferable to carry out the reaction at a temperature of 0 to 200°C, preferably 0 to 120°C. In this case, a compound having a photosensitizing effect such as benzophenone or acetophenone may be present if necessary.

Examples of light that can be used here include sunlight and ultraviolet rays.

In addition, when the reaction is carried out in the presence of various radical generators, it is often carried out at a temperature of 20 to 200°C, preferably 50 to 150°C. Azo compounds such as bisisobutyronitrile and phenylazotriphenylmethane, te
Examples include organic peroxides such as rt-butyl peroxide and benzoyl peroxide.

Note that the reaction may be carried out under light irradiation using a radical generator in combination.

Regarding the usage ratio of the starting raw material, it is preferable to use an amount of the organosilicon compound that provides at least one mercapto group to one group represented by formula (ii) in the polyoxyalkylene polyether. preferable.

In carrying out the above addition reaction, the use of a solvent is not particularly required, but if the starting material has a high viscosity and operations such as stirring are difficult, use an inert organic solvent as appropriate. These include aromatic hydrocarbon solvents such as benzene, toluene, and xylene, aliphatic hydrocarbon solvents such as hexane and octane, ether solvents such as ethyl ether, and ketone solvents such as methyl ethyl ketone. Examples include solvents and halogenated hydrocarbon solvents such as trichlorethylene.

The progress of the above reaction can be confirmed by the disappearance of alkenyl groups and mercapto groups in the starting materials and the quantitative determination of the -(OR3) group bonded to the silicon atom in the product.

According to the method of the present invention, the addition reaction can be carried out in an extremely short time, and the resulting silicone-modified polyoxyalkylene polyether having the group represented by the above formula (1) at the end of the molecular chain is It does not have strong intermolecular hydrogen bonds like urethane bonds, and has a low viscosity compared to its molecular weight, making it extremely easy to work with.

Furthermore, the polyether has industrial applications in that it can be easily cured at room temperature by using a curing agent such as a metal salt of carboxylic acid such as an alkyl titanate, tin octylate, or diptyl tin laurate. have

As mentioned above, the polyether obtained by the method of the present invention has various excellent characteristics and can be widely applied to sealing materials, electrical insulation materials, materials for producing elastomers, etc. in various fields.

Next, examples and reference examples of the present invention will be given.

Example 1 Has allyloxy groups at both ends of the molecular chain, and has a viscosity of approximately 790
At cS (25°C), 300 g of polyoxypropylene with an average molecular weight of 4100, 29 g of 3-mercaptopropyltrimethoxysilane, 1 g of benzophenone, and 200 g of toluene were charged into a flask, and while stirring, the mixture was heated with a high-pressure mercury lamp (400 W). The reaction was carried out by irradiating with light for 1 hour.

After the reaction was completed, the content of mercapto groups in the reaction solution was examined by oxidative titration, and 98% of the mercapto groups in the starting material were found.
It was confirmed that % had disappeared.

When the reaction solution obtained above was maintained at a temperature of 60°C under reduced pressure and toluene was distilled off, a yellow and colored viscous liquid (viscosity 8
10cS (25°C), average molecular weight approximately 4500) is 32
3g was obtained (yield 98%).

As a result of chemical analysis, this product was found to be a silicone-modified polyoxyalkylene polyether represented by the following molecular formula.

Analysis results 〇 Quantification of vinyl groups 0.01 mol/100 g or less 〇 Elemental analysis Calculated value Actual value Si (%) 1.25 1.22 S (%) 1.42 1.40 (MeO-)3Si-C3H6-8 -C3H6O-(C
3H6O)-69-C3H6-8-C3H6-8i(-
OMe) 3 Example 2 The reaction and treatment were carried out in the same manner as in Example 1 except that 26.6 g of 3-mercaptopropylmethyldimethoxysilane was used instead of 3-mercaptopropyltrimethoxysilane, resulting in a viscosity of 800 cS. (25
About 321 g of a viscous liquid with an average molecular weight of 4,400 was obtained (yield: 98%), which was found to be a silicone-modified polyoxyalkylene polyether having the following molecular formula from the results of chemical analysis.

Analysis results 〇 Quantification of vinyl groups 0.001 mol/100 g or less 〇 Elemental analysis Calculated value Actual value Si (%) 1.26 1.25 S (%) 1.43 1.41 Example 3 Allyloxy at both ends of the molecular chain group and has a viscosity of about 220
At 0 cS (25°C), 300 g of polyoxypropylene with an average molecular weight of 6000, 18 g of 3-mercaptopropyltrimethoxysilane, and 0.0 g of benzoyl peroxide.
2 g and 200 g of toluene were charged into a flask, and the reaction was carried out at a temperature of 100° C. for 16 hours while stirring.

Note that 0.1 g of benzoyl peroxide was added to the reaction system 4 hours and 8 hours after the start of stirring.

When the reaction solution obtained above was maintained at a temperature of 60°C under reduced pressure and toluene was distilled off, a yellow colored viscous liquid (viscosity: 2250cS (25°C), average molecular weight about 6300) was obtained.
10g was obtained (yield 97%).

As a result of chemical analysis, this product was found to be a silicone-modified polyoxyalkylene polyether represented by the following molecular formula.

Analysis results 〇 Quantification of vinyl groups 0.001 mol/100 g or less 〇 Elemental analysis Calculated value Actual value Si (%) 0.88 0.83 S (%) 1.06 1.01 Example 4 Allyloxy at both ends of the molecular chain group and has a viscosity of about 220
At 0 cS (25°C), 300 g of polyoxypropylene with an average molecular weight of 6000, 18 g of 3-mercaptopropyl (trimethylsiloxy) dimethoxysilane, 1 g of acetophenone and 200 g of toluene were charged into a flask.
While stirring, these were irradiated with light from a high-pressure mercury lamp (400 W) for 1 hour to carry out a reaction.

When the reaction solution obtained above was maintained at a temperature of 60°C under reduced pressure and toluene was distilled off, it was found to be a viscous liquid (viscosity approximately 230Qc).
s (25°C), average molecular weight approximately 6500) was obtained (yield 97%).

As a result of chemical analysis, this product was found to be a silicone-modified polyoxyalkylene polyether represented by the following molecular formula.

Analysis results 〇 Quantification of vinyl groups 0.001 mol/100 g or less ○ Elemental analysis Calculated value Actual value Si (%) 1,72 1.68 S (%) 0.98 0.96 Reference example Synthesized in Example 3 above After uniformly mixing 100 parts by weight of silicone-modified polyoxyalkylene polyether and 1 part by weight of dibutyltin dilaurate, it was formed into a sheet with a thickness of 2 mm, and then placed in an atmosphere at a temperature of 20°C and a relative humidity of 60%. When left to stand for 7 days, a cured sheet-like product was obtained.

When this material was examined for elongation, tensile strength and hardness according to JIS K 6301, the following results were obtained.

Growth rate 180% Tensile strength 4.9kg/crit.

Hardness 7

Claims (1)

[Scope of Claims] 1. A polyoxyalkylene polyether having a group represented by the formula at the end of the molecular chain and an organosilicon compound represented by the general formula, characterized in that the polyoxyalkylene polyether has a group represented by the formula at the end of the molecular chain. A method for producing a silicone-modified polyoxyalkylene polyether having a group represented by It represents a hydrocarbon group or a triorganosiloxy group, m is 0 or 1, and a is 1.2 or 3. ]