JPS5925808B2 - Method for producing silyl-terminated polymers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a polyether having moisture-curable silicon groups at its terminals.

A method for producing a reactive silicon-terminated polyether by using polyether as a starting material to produce a polyether having an olefin group at the end, and reacting this terminal olefin group with a silicon compound has already been disclosed in Japanese Patent Publication No. 1973- 36
319, Special Publication No. 4612154, Special Publication No. 48-3696
0 has been proposed.

According to these methods, since a low molecular weight hydroxy-terminated polyether is used as a raw material, there is a problem that the obtained olefin group-terminated polyether must also have a low molecular weight. When a reactive silicon-terminated polyether is produced by reacting a silicon compound with a silicon compound, a major problem arises in that the cured product of the reactive silicon-terminated polyether has very low elongation as a rubber elastic body. be.

Some of the present inventors have already taken the above points into consideration and have found that the terminal group of the molecule is mainly -0H group or -0M group (M is Na or K).
) by converting the -0H group of the polyether with the formula CH2-CH-R into a -0M group and reacting the -0M group with a polyvalent halogen compound to increase the molecular weight of the polyether. By reacting with an organic halogen compound represented by -X, 70% of the total terminal groups of polyether
The inventors discovered a method for producing a polyether having one CH2-CH-R-0 group and an average molecular weight of 4,000 to 15,000 and proposed it in Japanese Patent Application No. 5249174.

The above production method has the advantage that a high molecular weight polyether having an olefin group at the end can be obtained at low cost, and if the polyether is used to produce a reactive silicon-terminated polyether and a cured product is made, It has the excellent feature of producing a rubber elastic body with high elongation.

When producing a polyether having a terminal monofunctional moisture-curable silicon group by this method, a silicon hydride compound of the formula (where R4 and R5 are monovalent hydrocarbon groups having 1 to 12 carbon atoms; It is necessary to select a silicon compound represented by a hydrolyzable group such as a halogen or an alkoxy group.

The present invention provides a method for producing a polyether having a terminal monofunctional moisture-curable silicon group using a silicon hydride compound other than the above. Although the polyether produced by the method of the present invention is monofunctional, it has very high reactivity and has the excellent feature of carrying out a chain extension reaction in a short time upon curing. If the polyether of the present invention is cured in water using a compound such as tin as a catalyst, it will have a very high molecular weight and is monofunctional, so a cured product that is linear and soluble in solvents can be obtained. It will be done.

In addition, if it is cured together with a compound having a polyfunctional moisture-curable silicon group or the aforementioned polyether having a polyfunctional moisture-curable silicon group in addition to the catalyst, a cured product with a large molecular weight between the crosslinking points can be obtained. It has the characteristics of being able to obtain a rubber-like cured product with excellent physical and mechanical properties, particularly low modulus and high elongation. The present invention provides chemically bonded repeating units whose main chain essentially has the formula R1-0 (1) (wherein R1 is a divalent alkylene group having 2 to 4 carbon atoms),
and at the end of the molecule, a formula (in the formula, R2 is hydrogen or a monovalent organic group having 1 to 20 carbon atoms; R3 is a divalent organic group having 1 to 20 carbon atoms; a is O or 1
dihydrogenated siloxane containing two silicon hydride groups in the molecule and having 2 to 20 silicon atoms; The content is a method for producing a polyether having a molecular weight of 500 to 30,000 and having a silicon group at at least one terminal by reacting a compound in a molar amount exceeding 1/2 of the total number of moles of olefin end groups in the polyether. .

In the present invention, a polyether whose main chain essentially contains chemically bonded repeating units represented by the formula, and which contains at least 70% of all terminal groups at the molecular ends, is a terminal group represented by the formula. Used as starting material.

Specific examples of the chemically bonded structural unit represented by formula (1) include the following.

In the polyether main chain, not only one type of these structural units may be bonded, but also two or more types of structural units may be bonded in a mixed form, but in particular, polyethers manufactured using propylene oxide as a raw material may be bonded together. Polyether is good. Polyether thermoplastics having such structural units include ethylene oxide, propylene oxide, butene oxide,
It is manufactured using cationic polymerization and anionic polymerization methods using tetrahydrofuran as a raw material. Specifically, as a method for obtaining a polyether having an olefin group at the end, which is a starting material, an alkylene oxide, which has already been proposed in JP-A-50-13496 and JP-A-50-149797, is mixed with caustic potash and allyl alcohol or an aliphatic polyether. The molecular weight of the polyether is increased by polymerizing with a hydric alcohol, reacting with a polyhydric halogen compound as necessary, and then reacting with an allyl olefin compound to form a polyether having an allyl olefin group at the end. One example is a method for producing ether.

In addition, we proposed in Japanese Patent Application No. 52-49174 that the terminal groups of polyether whose molecular terminal groups are mainly hydroxyl groups are -0.
M (M-Na or K), then CH2-
A method for producing a polyether having 9 olefin groups at the terminals by reacting with an organic compound represented by CH-R-X is mentioned.

Various other methods listed in Japanese Patent Application No. 52-71411, Japanese Patent Application No. 5271412, etc. can be considered, but in the present invention, polyether 5 having a terminal olefin group obtained by any of the methods can also be used as a starting material. It can be used. The dihydrogenated siloxane compound used is
Those having 2 to 20 silicon atoms are used, and organopolysiloxane compounds are preferred. The organopolysiloxane compound is any linear, O-branched, cyclic, or network compound, and the organo group is one having 1 to 12 carbon atoms selected from alkyl groups, aryl groups, etc.
Particularly preferred are hydrocarbon groups. Dihydrogenated siloxane compounds can be used alone or in the form of mixtures. Specific examples include the following.

In the present invention, it is advantageous to use a platinum-based catalyst when reacting the dihydrogenated siloxane compound.

Particularly favorable results are obtained using catalysts such as chloroplatinic acid, platinum metal, platinized activated carbon, platinum chloride, and platinum olefin complexes. Any temperature in the range of 30 to 150°C can be used to carry out this reaction, but
In particular, it is preferable to conduct the reaction at a temperature in the range of 50 to 120°C. Solvents may or may not be used, but if used, ethers, aliphatic hydrocarbons, aromatic hydrocarbons, and...
Inert solvents without active hydrogen, such as logenated hydrocarbons, are suitable. The amount of dihydrogenated siloxane compound used is 1/2 of the total number of moles of olefin end groups in the polyether.
If the mole exceeds twice that, it can be freely selected, but by reacting the olefin end group with about the same molar amount of dihydride siloxane compound, it is possible to efficiently create a polyether with a silicon hydride group in the end group. can be manufactured. If it is used in excess of equimolar, it is possible to similarly introduce a silicon hydride group into the terminal group, but this is economically disadvantageous since the excess silicon dihydride group remains unreacted. If the mole is selected between equimolar and more than 1/2 times, the molecular weight increase reaction and the hydrogenation to the terminal group will occur depending on the number of moles of the terminal olefin group and the number of moles of the silicon dihydride group of the raw material polyether. The amount of the siloxane compound used can be selected depending on the molecular design of the intended silicon hydride group-terminated polyether. When the silicon-terminated polyether produced according to the present invention is placed under appropriate conditions, it condenses and polymerizes under the action of moisture, forming a linear viscoelastic body.

In addition, when exposed to the atmosphere together with a compound having a polyfunctional hydrolyzable silicon group or a polyether having a polyfunctional moisture-curable silicon group, the network structure is formed three-dimensionally due to the action of moisture. forms and hardens to a solid with rubber-like elasticity. Since the curing rate varies depending on atmospheric temperature, relative humidity, and the type of hydrolyzable group, it is necessary to carefully consider the type of hydrolyzable group when using the resin. A silanol condensation catalyst may or may not be used in curing the less-silicon polyether of the present invention and a composition containing the polyether as an active ingredient.

Alkyl titanates if condensation catalysts are used; organosilicon titanates: metal salts of carboxylic acids such as tin octylate, dibutyltin laurate and dibutyltin maleate, dibutyltin phthalate, etc.: dibutylamine-2-ethylhexo Known silanol condensation catalysts such as amine salts, such as ates, and other acidic and basic catalysts are usefully used. The amount of these condensation catalysts used is preferably from 0 to 10% by weight based on the silicon-terminated polyether. The less-silicon polyether of the present invention can be modified by incorporating various fillers, such as reinforcing fillers such as fume silica, precipitated silica, anhydrous silicic acid, hydrous silicic acid, and carbon black: Fillers such as calcium carbonate, magnesium carbonate, diatomaceous earth, calcined clay, clay, talc, titanium oxide, bentonite, organic bentonite, ferric oxide, zinc oxide, activated zinc white and shirasu balloon; asbestos, glass fiber Fibrous fillers such as filaments and filaments can be used.

If you want to obtain a hardened composition with high strength using these fillers, use mainly fume silica, precipitated silica, anhydrous silicic acid, hydrated silicic acid, carbon black, surface-treated fine calcium carbonate, calcined resin, clay, and activated silica. Favorable results can be obtained if the filler selected from zinc white or the like is used in an amount of 1 to 100 parts by weight based on 100 parts by weight of the silicon-terminated polyether. In addition, when it is desired to obtain a cured composition with low strength and high elongation, fillers mainly selected from titanium oxide, calcium carbonate, magnesium carbonate, talc, ferric oxide, zinc oxide, and shirasu balloon are used. Favorable results can be obtained if it is used in an amount of 5 to 200 parts by weight per 100 parts by weight of silicon-terminated polyether. Of course, these fillers may be used alone or in a mixture of two or more. In the present invention, it is more effective to use a plasticizer in combination with a filler because the elongation of the cured product can be increased and a large amount of filler can be mixed.

The plasticizer is one that is commonly used. For example, phthalate esters such as dioctyl phthalate, dibutyl phthalate, butylbenzyl phthalate, etc.; aliphatic dibasic acid esters such as dioctyl adipate, isodecyl succinate, dibutyl sebacate, etc.; diethylene glycol dibenzoate, pentaerythritol ester, etc. Glycol esters: Butyl oleate, methyl acetyl ricinoleate, etc. Aliphatic esters: Tricresyl phosphate, trioctyl phosphate, octyl diphenyl phosphate, etc. Phosphate esters: Epoxidized soybean oil, benzyl epoxy stearate Epoxy plasticizers such as chlorinated paraffin, etc.; plasticizers such as chlorinated paraffin can be optionally used alone or in the form of a mixture of two or more types. The amount of plasticizer is silicon-terminated polyether 1
Preferable results can be obtained when the amount is used in the range of 0 to 100 parts by weight. Fillers, plasticizers, and condensation catalysts are mainly used in the compounded composition containing silicon-terminated polyether as an active ingredient in the present invention, but adhesion promoters such as phenolic resins and epoxy resins, pigments, anti-aging agents, The optional use of additives such as ultraviolet absorbers is also included.

The composition of the present invention containing silicon-terminated polyether as an active ingredient can be either a one-part composition or a two-part composition.

When used as a two-component composition, for example, it is divided into a component consisting of silicon-terminated polyether, a filler, and a plasticizer, and a component consisting of a filler, plasticizer, and condensation catalyst, and the two components are mixed immediately before use. Use it with good results.

When used as a one-component composition, the silicon-terminated polyether, filler, plasticizer, and condensation catalyst can be thoroughly dehydrated and dried, then mixed in the absence of moisture, and stored in a cartridge to ensure storage safety. It can also be used as a good one-component composition.

The composition of the monofunctional silicon-terminated polyether obtained in the present invention and the polyfunctional silicon-terminated compound or its polyether increases as the amount of the monofunctional silicon-terminated polyether increases. becomes larger and the elastic modulus becomes lower. Therefore, it is particularly useful as a one-part and two-part elastic architectural sealant, and can also be used as a sealant for ships, automobiles, roads, etc. Furthermore, it can be used alone or with the aid of a blimmer to adhere to a wide range of substrates such as glass, porcelain, wood, metal, resin moldings, etc., and therefore can be used in various types of sealing and adhesive compositions. be. Furthermore, food packaging materials, cast rubber materials,
It is also useful as a molding material and paint. Examples will be specifically described below.

Reference Example 1 (8) Polyoxypropylene having an allyl olefin group at the end is synthesized according to the method disclosed in Japanese Patent Application No. 52-49174.

Polyoxypropylene glycol having an average molecular weight of 3200 and powdered caustic soda are stirred at 60°C, and bromochloromethane is added to carry out a reaction to increase the molecular weight.

Next, allyl chloride is added to allyl etherify the terminal at 110°C. This was treated with aluminum silicate to synthesize purified end-allyl etherified polyoxypropylene. The average molecular weight of this polyether is 80
80, and from the determination of iodine value and OH value, the terminal 97
% were olefin groups and 3% were hydroxyl groups.

Example 1 4007 of the polyether of Reference Example 1 was placed in a 1f pressure-resistant reaction vessel equipped with a stirrer.

Catalyst solution of chloroplatinic acid (H2PtCl2.6H203.
97 dissolved in 18 ml of isopropyl alcohol and 160 ml of tetrahydrofuran) 0.17 ml (1 x 10-4 times the mole of the polymer end), 1.1.1.3.5
・7,7,7-octamethyltetrasiloxane 27.9
7 (equal moles of polymer terminals) was added and reacted at 80° C. for 4 hours. The remaining hydrosilyl groups were quantified from IR spectrum, and the reaction rate was 89%.

The product had a viscosity of ηSp/C-0.264 (30°C, toluene solution [C]-0.807/DO) and an average molecular weight of 8480.

This shows that silicon dihydride reacted at the terminal without causing side reactions such as molecular weight increase reactions.

2% by weight of tin octylate was added to this product and the mixture was heated at 70°C.
When the film was left under saturated steam conditions for 15 hours, a small amount of hydrogen gas bubbles were released and the film thickened and hardened.

This substance is 100% soluble in toluene and ηSp/C
It had a viscosity of -0.778. This shows that the terminal group is a silicon hydride group, and a polyether with monofunctionality at one end is produced. Reference Example 2 Polyether 4007 from Reference Example 1 and 0.17ml of a catalyst solution of chloroplatinic acid and 25.17ml of methyldichlorosilane (1.1 times the mole of the terminal) were reacted at 80°C for 4 hours, and then the reaction system was Lower the temperature to 60°C, propylene oxide 477,
Add 20.9y of methanol and react at 80°C for 3 hours with stirring.

After that, the temperature was raised to 90℃ and volatile components were removed under reduced pressure, and the terminal group was (CH3O)2Si-CH2CH2CH2
Polyoxypropylene having O groups was obtained. Example
2 Parts by weight of the silicon-terminated hydrogenated polyether obtained in Example 1 and the dimethoxy-terminated silicon-terminated polyether of Reference Example 2, (A) 5/95, (B) 10/90, (C) 20/
Blended at a ratio of 80.

Next, to 100 parts by weight of these polyethers, 30 parts by weight of butylbenzyl phthalate, 50 parts by weight of fatty acid-treated calcium carbonate, 30 parts by weight of light calcium carbonate, 25 parts by weight of titanium oxide, 3 parts by weight of organic bentonite, and 5 parts by weight of silicic acid anhydride. parts, carbon black 0.5 parts by weight, NBCI parts by weight as anti-aging agents, NS6l parts by weight, Tinupin 3 parts by weight
270.5 parts by weight of activated zinc white 5 was added as a hardening agent.
1 part and 2 parts of dibutyltin phthalate and mixed with three paint rolls to form a blended composition. 23% of the composition
The table shows the results of a tensile test conducted in accordance with JIS 5754 on products that were cured for 7 days at 60% humidity and then 7 days at 50°C or 7 days at 9°C. .

Example 3 A polyether synthesized under the same conditions as Reference Example 1 was used except that methallyl chloride was used instead of allyl chloride, and the same conditions as Example 1 were used except that the reaction time was 8 hours. The reaction was carried out.

As a result of quantifying the remaining hydrosilyl groups from IR spectrum, the reaction rate was 75% and the average molecular weight was 8,370.

Examples 4 to 7 The reaction was carried out under the same conditions as in Example 1, using polyethers synthesized under the same conditions as in Reference Example 1, except for using the organic halides shown in the table below instead of allyl chloride. Ivy.

Quantifying the remaining hydrosilyl group from the IR spectrum,
The calculated reaction rate and average molecular weight of the obtained product are shown in the table below.

2% by weight of tin octylate was added to these products, and 7
When it was left under saturated steam conditions at 0°C for 15 hours, hydrogen gas bubbles were released and the product thickened and hardened.

These were 100% soluble in toluene. This shows that a polyether whose terminal group is a monofunctional silicon hydride group is produced.

Example 8 Polyether 400y1 of Reference Example 1 0.17ml of chloroplatinic acid catalyst solution and 1.1.1.3.5.7
・7.7 octamethyltetrasiloxane 27,97 to 9
The reaction was carried out at 0° C. for 4 hours to obtain polyoxypropylene with terminal groups (referred to as A).

Next, as a comparative example, polyether 4007 of Reference Example 1,
0.17 ml of a catalyst solution of chloroplatinic acid and 19.67 ml of dimethylmethoxysilane (1.1 times the mole of the terminal) were reacted at 80°C for 4 hours to obtain polyoxypropylene whose terminal group is a - group (B and do).

When 2% by weight of tin octylate was added to each of the above polyoxypropylenes A and B and left under saturated steam conditions at 70°C, A immediately started to thicken, and after 15 hours the viscosity increased further. Although it was viscous and hardened, in the case of B, almost no increase in viscosity was observed even after 20 hours.

Claims (1)

[Claims] 1 The main chain essentially has the formula (1) -R^1-O-(1) (wherein R^1 is a divalent alkylene group having 2 to 4 carbon atoms) Contains a chemically bonded repeating unit represented by, and at the end of the molecule, there is a formula (2) ▲ a mathematical formula, a chemical formula, a table, etc. ▼ (2) (where R^2 is hydrogen or a carbon number of 1
~20 monovalent organic groups; R^3 is a divalent organic group having 1 to 20 carbon atoms; a is an integer of 0 or 1). Ether contains two silicon hydride groups in the molecule and has 2 to 2 silicon atoms.
A polyether having a molecular weight of 500 to 30,000 and having a silicon group at at least one end thereof, which is characterized by reacting a dihydrogenated siloxane compound having a molecular weight of 0 to 1/2 times the number of moles of all olefin terminal groups in the polyether. manufacturing method. 2. The manufacturing method according to claim 1, wherein the dihydrogenated siloxane compound has a structural unit represented by formula (3) (a mathematical formula, a chemical formula, a table, etc.) in its molecule. 3. The manufacturing method according to claim 1, wherein the dihydrogenated siloxane compound is 1,1,3,3-tetramethyldisiloxane. 4 The dihydrogenated siloxane compound is 1, 1, 1, 3, 5,
7.7.7-Octamethyltetrasiloxane is the manufacturing method according to claim 1.