JP2000038451A - Production of alkoxy-terminated polydiogranosiloxane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject compound having excellent preservation stability and no harmful effect for curability and useful as a rapidly curable dealcoholization-type sealant or the like by reacting a specified polydiorganosiloxane with a specified silicon compound in the presence of an acidic amine salt. SOLUTION: This compound is obtained by reacting a polyorganosiloxane having terminally a silanol group of the formula [R1 is a univalent hydrocarbon; (n) is such a number to be 10-100,000 cP in its viscosity] with an alkoxy group- including silicon compound having >=2 R2 groups in the molecule (R2 is a 1-10C alkyl) coupled to a silicon atom through a oxygen atom in the presence of an acidic amine salt and bringing the resultant reaction product into contact preferably with an amorphous or porous complex or powdery mixture of zinc oxide and silicon dioxide. The alkoxy group-including silicon compound is preferably a silane including an alkoxy group of the formula: R34-aSi(OR2)a [R3 is a univalent hydrocarbon; (a) is 2-4].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a polydiorganosiloxane having an alkoxy group at a molecular terminal, and more particularly, to a method for producing an alkoxy group-terminated polydiorganosiloxane from a silanol-terminated polydiorganosiloxane.

[0002]

2. Description of the Related Art A polydiorganosiloxane having silanol groups at both ends of a molecule is reacted with a silane compound having an alkoxy group bonded to a silicon atom or a partial hydrolysis condensate thereof to form a crosslinked three-dimensional siloxane skeleton structure. It is widely known that a rubber-like elastic body can be obtained by forming it. Utilizing such crosslinking by the dealcoholization reaction, a single-package room-temperature-curable polyorganosiloxane composition containing each component in a single sealed container protected from moisture is corroded by by-products during curing. Since it has no irritating odor, it is widely used as a sealant for construction, an adhesive for the electric and electronic industries, a sealant, and the like.

[0003] This kind of composition has a problem that the curing speed is low, the storage stability is poor even when stored in an anhydrous state, and the composition does not cure. It is considered that this is because the alkoxy group in the silane compound or its partial hydrolyzate is decomposed during storage due to the hydroxyl group at the terminal of the polydiorganosiloxane.

[0004] Therefore, a one-package room temperature curable polyorganosiloxane composition obtained by a dealcoholization reaction using an alkoxy-terminated polydiorganosiloxane in which an alkoxy group is introduced instead of a silanol group at the end of the polydiorganosiloxane is used as a base polymer. Improvements have been made in the storage stability and curability of products.

[0005] Polydiorganosiloxanes having alkoxy groups bonded to silicon atoms at both ends of the molecule include, for example, polydiorganosiloxanes having silanol groups at both ends of the molecule, which are represented by the general formula (III):

Embedded image (Wherein, R ² is an unsubstituted or substituted C 1-10
R ³ represents an unsubstituted or substituted monovalent hydrocarbon group; Y represents a hydrolyzable group; b
Is an integer of 1 to 3). In this case, if a halogen atom such as a chlorine atom is used as Y, the alkoxy group is attacked by hydrogen chloride generated by the reaction, and a hydrolysis reaction is likely to occur. If an amine compound such as triethylamine, pyridine or picoline is used as the hydrogen chloride scavenger to prevent this, a complicated step of filtering off the fine crystals of the generated amine hydrochloride becomes necessary.

On the other hand, when a silane compound having a group other than a halogen atom, for example, the same or different alkoxy group as OR ² is used as Y, the reactivity with the terminal silanol group of the polydiorganosiloxane is low. No. 2,909,549 discloses a method of reacting in the presence of a strongly basic substance such as potassium hydroxide, potassium silanolate, sodium hydroxide. However, when such a catalyst is used, a rearrangement reaction accompanied by siloxane cleavage occurs, and the desired polydiorganosiloxane having alkoxy groups at both ends cannot be obtained with high purity.

As an improvement method, Japanese Patent Laid-Open Publication No.
No. 37 discloses a method of neutralizing the strong basic substance before such a rearrangement reaction occurs. However, such methods are not only difficult to control,
If a neutralizing agent is present in excess of a strong acid, a weak acid or a hydrogen chloride release substance such as methylchlorosilanes, the neutralizer or the acidic substance released therefrom attacks the alkoxy groups of the resulting alkoxy-terminated polydiorganosiloxane. Hydrolysis.

[0008] JP-A-2-182728 discloses a method using lithium hydroxide as a catalyst for the above reaction. However, in this method, it is difficult to control the reaction to obtain a desired reaction rate and reaction efficiency.

Further, when the alkoxy-terminated polydiorganosiloxane produced by these methods is blended and stored as a base polymer in a room-temperature curable polyorganosiloxane composition containing a curing catalyst, alcohol or water produced as a by-product may be used. The presence causes a terminal group cleavage reaction. Therefore, for example, in the case of a self-curable alkoxy-terminated polydiorganosiloxane having a methyldimethoxysilyl group as a terminal group and containing no crosslinking agent, the self-curability is lost during storage.

Therefore, blending of a silicon-nitrogen compound or enoxysilane as a scavenger for the remaining alcohol is described in US Pat. No. 4,395,526. However, such compounds are
The trapping reaction is undesirable because it produces ammonia, which causes unpleasant odors and equipment corrosion, or acetone, which causes the composition to color.

Japanese Unexamined Patent Publication (Kokai) No. 1-113429 discloses that a system in which a silanol-terminated polydiorganosiloxane is reacted with an alkoxy-containing silicon compound in the presence of an acidic amine salt exhibits an appropriate reaction rate and is as described above. It is disclosed that a side reaction such as a siloxane bond cleavage reaction does not occur without using a scavenger. However, if the acidic amine salt used here as a catalyst or the amines as its starting material are present in the product, a chelating compound having an alkoxide or alkoxy group of titanium, zirconium or aluminum as a curing catalyst for the composition. When is used, the catalyst is oriented to the alkoxy group of these catalysts to reduce the activity of the catalyst. When the acidic amine salt or the carboxylic acid as a starting material thereof is present in the product, the storage stability of the composition is reduced when a metal salt of an organic acid is used as a curing catalyst for the composition.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the storage stability of a polydiorganosiloxane terminated with silanol groups when used as a base polymer of a room-temperature-curable polydiorganosiloxane composition. An object of the present invention is to provide a method for producing an alkoxy group-terminated polydiorganosiloxane which is excellent and does not adversely affect the curability, with a high yield. In the present invention,
"Alkoxy group-terminated polydiorganosiloxane"
It refers to a polydiorganosiloxane in which an unsubstituted or substituted alkoxy group is bonded to a terminal silicon atom.

[0013]

Means for Solving the Problems As a result of repeated studies to achieve the above object, the present inventors have found that a silanol-terminated polydiorganosiloxane is reacted with an alkoxy group-containing silicon compound in the presence of an acidic amine salt. After that, it has been found that the object can be achieved by bringing the reaction product into contact with a composite or powder mixture of zinc oxide and silicon dioxide, thereby completing the present invention.

That is, the method for producing the alkoxy-terminated polydiorganosiloxane of the present invention is represented by the general formula (I):

Embedded image Wherein R ¹ represents an unsubstituted or substituted monovalent hydrocarbon group which may be the same or different;
Is a number that brings the viscosity to 10 to 100,000 cP). R is bonded to a silicon atom via an oxygen atom.
² (R ² represents an unsubstituted or substituted alkyl group having 1 to 10 carbon atoms) in the molecule of an unsubstituted or substituted alkoxy group-containing silicon compound having at least two groups represented by the following formula: After reacting in the presence, the reaction product is contacted with a composite or powder mixture of zinc oxide and silicon dioxide.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The first step of the production method of the present invention comprises:
In this step, an unsubstituted or substituted alkoxy-containing silicon compound is reacted with a silanol-terminated polydiorganosiloxane to synthesize an alkoxy-terminated polydiorganosiloxane.

In the first step, the silanol-terminated polydiorganosiloxane used as a starting material is, as shown by the above-mentioned general formula (I), a substantially straight chain in which hydroxyl groups are bonded to silicon atoms at both ends. Polydiorganosiloxane. R ¹ is an unsubstituted or substituted monovalent hydrocarbon group, which may be the same or different, and methyl, ethyl, propyl, butyl, pentyl,
Alkyl groups such as hexyl, heptyl, octyl, nonyl, and decyl; cycloalkyl groups such as cyclohexyl; alkenyl groups such as vinyl and allyl;
Aryl groups such as tolyl; 2-phenylethyl, 2-
Aralkyl groups such as phenylpropyl; and chloromethyl, 3-chloropropyl, 3,3,3-trifluoropropyl, in which part or all of the hydrogen atoms of these groups are substituted with halogen atoms, cyano groups, and the like. -Substituted hydrocarbon groups such as cyanopropyl. The polydiorganosiloxane, which is easy to synthesize and obtains a rubber-like elastic body having excellent mechanical properties by curing, has a relatively low viscosity. Since the siloxane composition is easy to handle, and the cured elastomer has various properties such as heat resistance, cold resistance, and low surface tension, which are characteristics of silicone, in a well-balanced manner, 85 mol% or more of R ¹ is methyl. Group, and more preferably a 100% methyl group. In the cured composition, a phenyl group is required when light transmittance, radiation resistance, or even better cold resistance is required, and a 3,3,3-trifluoropropyl group is required when oil resistance or solvent resistance is required. Any R ¹ can be used in combination with a methyl group, such as a long-chain alkyl group or an aralkyl group when excellent surface coating properties are required.

N represents a viscosity of the silanol-terminated polydiorganosiloxane at 25 ° C. of 10 to 100,000.
The number is 0 cP, preferably 500 to 30,000 cP. This means that when all of the above R ¹ are methyl groups,
15 to 3,000, preferably 150 to 1,200.

Examples of such a silanol-terminated polydiorganosiloxane include α, ω-dihydroxypolymethylsiloxanes, such as α, ω-dihydroxypolydimethylsiloxane, in which some of the methyl groups are substituted with other organic groups. Examples include phenylsiloxane, α, ω-dihydroxypolymethyl (3,3,3-trifluoropropyl) siloxane, α, ω-dihydroxypolymethyldecylsiloxane, α, ω-dihydroxypolymethyl (2-phenylpropyl) siloxane. Is done.

In the first step, the unsubstituted or substituted alkoxy group-containing silicon compound to be reacted with the silanol group-terminated polydiorganosiloxane contains at least two unsubstituted or substituted alkoxy groups bonded to silicon atoms in the molecule.
A substituted or unsubstituted alkoxy group at the end of the siloxane by reacting one of the alkoxy groups with a silanol group of the polydiorganosiloxane.

Examples of the unsubstituted or substituted alkoxy group-containing silicon compound of the general formula ^{_{(II): R 3 4 -}} a Si (OR 2) a (II) ( wherein, R ² is as described above; R ³ represents an unsubstituted or substituted monovalent hydrocarbon group which may be the same or different; a is an integer of 2 to 4) Although it is typical and most preferable because of easy synthesis, depending on the purpose, for example, in order to obtain a base polymer of a room-temperature curable composition which is fast-curing and excellent in mechanical strength and adhesiveness, it is difficult to obtain the base polymer. A partially hydrolyzed condensate of a substituted or substituted alkoxy group-containing silane, particularly a resin-like partially hydrolyzed condensate may be used, and the unsubstituted or substituted alkoxy group-containing silane and another silane having a silicon functional group may be used. Conversion It can be used partially hydrolyzed condensate of the goods or siloxane compound.

R ² is an unsubstituted or substituted C 1 -C 1
10 alkyl groups. R ² represents a linear or branched alkyl group such as methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, and decyl;
And substituted alkyl groups such as 2-methoxyethyl and 2-ethoxyethyl, and methyl, ethyl and 2-ethoxyethyl groups are preferred in view of their reactivity.

R ³ is an unsubstituted or substituted monovalent hydrocarbon group, and when two or more are present in the molecule, they may be the same or different. Further, two or more kinds may be used in combination depending on the purpose. R ³ is methyl, ethyl, propyl, butyl, pentyl, hexyl,
Alkyl groups such as heptyl and octyl; cycloalkyl groups such as cyclohexyl; alkenyl groups such as vinyl and allyl; aryl groups such as phenyl and tolyl;
Aralkyl groups such as 2-phenylethyl and 2-phenylpropyl; and substituted hydrocarbon groups such as 3-glycidoxypropyl and 3-methacryloxypropyl; Since the reactivity of the unsubstituted or substituted alkoxy group of the group-terminated polydiorganosiloxane is excellent, and when this is used as a base polymer of a room temperature-curable polydiorganosiloxane composition, an excellent curing rate is obtained, the methyl group and the vinyl group are used. Groups are preferred.

Examples of the unsubstituted or substituted alkoxy group-containing silane having R ² and optionally R ³ include tetramethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, vinyltrimethoxysilane, Methoxysilanes such as dimethyldimethoxysilane and methylvinyldimethoxysilane; and ethoxysilanes and 2-methoxyethoxysilanes corresponding thereto are exemplified. Methyltrimethoxysilane and vinyltrimethoxysilane are preferred, and methyltrimethoxysilane is preferred. Silanes are particularly preferred. Further, as described above, examples of the unsubstituted or substituted alkoxy group-containing silicon compound include, in addition to the above-mentioned unsubstituted or substituted alkoxy group-containing silanes, partially hydrolyzed condensates of the silanes, particularly methyltrimethoxysilane, methyl Triethoxysilane,
Examples include partially hydrolyzed condensates such as vinyltrimethoxysilane.

The amount of the unsubstituted or substituted silicon compound used is at least 1 mol per mol of the silanol group in the silanol-terminated polydiorganosiloxane, and 0.5 to 100 parts by weight per silanol-terminated polydiorganosiloxane. 10.0 parts by weight is preferred, and 0.5-3.
0 parts by weight is more preferred.

In the present invention, the catalyst used in the first step for the reaction between the silanol-terminated polydiorganosiloxane and the unsubstituted or substituted alkoxy-containing silicon compound is an acidic amine salt. In the present invention, "acidic amine salt" refers to the pH of an aqueous solution when dissolved in pure water.
Is less than 7.

As the above-mentioned acidic amine salt, a lower carboxylic acid alkylamine salt is usually used, and a carboxylic acid such as formic acid or acetic acid has 1 to 3 alkyl groups having 3 to 8 carbon atoms. Amine salts are preferred. Formic acid is more preferred because of its catalytic ability. On the other hand, on the amine side, dialkylamine salts are more preferred, and di-n-butylamine and diisobutylamine salts are particularly preferred. When a tin chelate compound such as dibutylbis (acetylacetonato) tin is used as a curing catalyst for the composition, the cured composition does not cause yellowing, and therefore a di (branched alkyl) such as a diisobutylamine salt is used. Amines are preferred.

As the acidic amine salt, a preformed one may be added to the system, or a carboxylic acid and an amine may be separately added to the system. In the latter case, both starting materials function as catalysts by forming an acidic amine salt by an exothermic reaction. In this case, the carboxylic acid and the amine are preferably added in an equimolar amount, but the organic acid may be added in an excess of 15 times the molar amount of the amine. Among these methods, it is preferable to add in the form of an acidic amine salt because of high catalytic activity and easy progress of the polymerization reaction.

The amount of the acidic amine salt is not particularly limited, but may be a silanol-terminated polydiorganosiloxane 100.
0.005 to 3.0 parts by weight per part by weight is preferable,
0.05 to 0.3 parts by weight is more preferred. When the carboxylic acid and the amine are separately added, it is preferable to add 0.001 to 1.0 part by weight on the same basis.

In the reaction of the first step, a mixture of a silanol-terminated polydiorganosiloxane, an unsubstituted or substituted alkoxy group-containing silicon compound and an acidic amine salt is usually stirred at 50 to 100 ° C., preferably 70 to 100 ° C.
C. for an appropriate time, for example 0.5 to 2 hours, when the unsubstituted or substituted alkoxy-containing silicon compound is typically a silane, the general formula (IV):

Embedded image Wherein R ¹ , R ² , R ³ , n and a are as described above, an alkoxy-terminated polydiorganosiloxane is formed as the reaction product. The reaction generally does not require a diluting solvent, but if necessary, a diluting solvent such as toluene or xylene may be used.

In the second step of the production method of the present invention, the alkoxy-terminated polydiorganosiloxane obtained in the first step, the acidic amine salt used as a catalyst in the first step,
The catalyst and / or its starting material is removed by contacting the reaction product containing the carboxylic acid and / or amines added as its starting material with a composite or powder mixture of zinc oxide and silicon dioxide. This is the step of performing

In the second step, the compound used as a catalyst remover such as the above-mentioned acidic amine salt may be a composite of zinc oxide and silicon dioxide, or may be a powder mixture.
It is preferable that it is a composite from that effect.

The composite includes a composite oxide such as zinc orthosilicate, zinc metasilicate, and a mixture thereof, zinc oxide and silicon dioxide, and the above-mentioned composite oxide is partially present. And the like, and an amorphous compound is particularly preferable.

The ratio of zinc oxide and silicon dioxide in the composite or powder mixture is calculated separately for each constituent oxide when they form a composite oxide, and the molar ratio of both oxides is 1: 1: The range of 1-1: 8 is preferable, and 1: 2-
A range of 1: 5 is more preferred.

The composite is preferably in the form of a powder having an average particle size of 0.1 to 2 μm, more preferably 0.3 to 1.2 μm, because of its excellent adsorption effect.
On the other hand, since the composite can be easily removed from the system by filtration after the second step, the average particle size is 0.5 to 4.0.
Granules of 0 μm are preferred. Granular and powdered materials can be used in combination. Also, from the ability to remove acidic amine salts, etc., the specific surface area is 80 to 200 m ² / g
Are preferred.

The method for producing the composite is not particularly limited. In particular, as a method for producing an amorphous composite, for example, an aqueous solution of a water-soluble zinc salt such as zinc chloride, zinc sulfate, or zinc nitrate; An aqueous solution is mixed and reacted to form an amorphous composite slurry of zinc oxide and silicon dioxide, and a desired product is separated and dried at a temperature of 300 ° C. or lower. An aqueous solution of a zinc salt and an aqueous solution of sodium silicate may be separately added to the formed composite slurry at the same time.

When zinc oxide and silicon dioxide powder are mixed and used, it is preferable to use a mixture having the same average particle size as the composite.

The second step is carried out by adding a catalyst removing agent, which is a composite or a powder mixture of zinc oxide and silicon dioxide, to the product of the first step, followed by stirring. Alternatively, the catalyst-removing agent is suspended in a binder such as a water-soluble acrylic resin and adhered to a polyester nonwoven fabric. Similarly, a method may be used in which the above-mentioned product is permeated through a paper to which a catalyst removing agent is internally added and / or a layer of the catalyst removing agent.

The amount of the catalyst remover to be used is not particularly limited, but when the stirring method is used, it is sufficient that the amount is not more than 20 parts by weight per 100 parts by weight of the alkoxy group-containing polydiorganosiloxane. The stirring conditions may be 0.5 to 2 hours at room temperature, and depending on the viscosity of the alkoxy group-terminated polydimethylsiloxane, in order to increase the fluidity and the accompanying processing effect,
It may be heated.

[0039] The catalyst removal agents, especially composite of zinc oxide and silicon dioxide, the surface is weakly ionized, -Sn ⁺
There are a —O— cation and a —Si—O ⁻ — anion.
Due to the presence of such both ions, especially in the case of using a porous composite, its high specific surface area enables good adsorption of the acidic amine salt used as a catalyst and its starting materials, carboxylic acids and amines. can do.

In the case of the stirring method, after the second step, the catalyst removing agent is removed from the system by a method such as filtration to obtain a purified alkoxy-terminated polydiorganosiloxane. Filtration can be performed by a usual method using a filter aid such as diatomaceous earth.

[0041]

The present invention will be described in more detail with reference to the following examples. The present invention is not limited by these examples. In these examples, parts represent parts by weight, and physical properties such as viscosity are values at 25 ° C.

Comparative Example 1 In a reactor equipped with a stirrer, heating mantle, condenser and thermometer, 500 parts of α, ω-dihydroxypolydimethylsiloxane having a viscosity of 18,400 cP, 10 parts of methyltrimethoxysilane, and Then, 3.4 parts of -butylamine salt was charged and heated at 75 ° C for 1 hour with stirring in a nitrogen stream to synthesize α, ω-bis (methyldimethoxy) polydimethylsiloxane.

The product was cooled and used as it was as a sample in Comparative Example 1 and used as a sample in a purification experiment according to Examples 1 to 3. The obtained polydimethylsiloxane did not form a gel when left mixed with titanium tetraisopropoxide, and it was confirmed that there was no silanol group at the terminal.

Example 1 An energy dispersive electron probe microanalyzer having an average particle size of 0.5 μm, a specific surface area of 150 m ² / g and a catalyst remover was added to 100 parts of the product obtained in Comparative Example 1. 10 parts of an amorphous / porous composite of zinc oxide and silicon dioxide having a molar ratio of zinc oxide to silicon dioxide of 1: 4, determined from the atomic ratio of Zn: Si obtained by the method described above, and stirred at room temperature for 1 hour did. Then, a purified α, ω-bis (methyldimethoxy) polydimethylsiloxane sample was obtained through a filter tube using Radiolite No. 500 (trade name of Showa Chemical Industry Co., Ltd.) as a filter aid.

Example 2 The same composite of zinc oxide and silicon dioxide as used in Example 1 was dispersed in an acetone solution of a methacrylic acid-based water-soluble polymer to form a 1 mm-thick polyester nonwoven fabric. After application, the acetone was volatilized to obtain a polyester nonwoven fabric having the above composite adhered to the nonwoven fabric substrate by 65% by weight. Similarly, the above composite is applied to a paper substrate for 1 hour.
A paper with an internal addition of 00% by weight was obtained. The three layers of the nonwoven fabric and the two layers of paper having the composite attached thereto are alternately stacked and fixed to the joint of the vertical glass tube connected in series with a flange,
Furthermore, a particle diameter of 2.0 to 4.0, which is composed of an amorphous / porous composite of the above composition of zinc oxide and silicon dioxide.
The granules distributed in 0 mm were spread to a thickness of 200 mm to prepare an adsorption device.

100 parts of the product obtained in Comparative Example 1 was passed through the adsorption device thus prepared. The liquid passing through the granular layer of the composite, the layer of the nonwoven fabric to which the composite is attached, and the layer of paper to which the composite is internally added is collected and purified α, ω
-A bis (methyldimethoxy) polydimethylsiloxane sample was obtained.

Example 3 The procedure of Example 1 was repeated using 100 parts of the product obtained in Comparative Example 1.
The same operation as described above was performed, and the obtained product was further subjected to Example 2.
By performing the same operation as described above, a purified α, ω-bis (methyldimethoxy) polydimethylsiloxane sample was obtained.

Evaluation The purified α, ω-bis (methyldimethoxy) polydimethylsiloxane sample obtained in Examples 1 to 3 and the unpurified polysiloxane sample obtained in Comparative Example 1 were as follows. The curability, storage stability, and the electrical conductivity of the extracted water were evaluated.

Curing property 50 parts of methyltrimethoxysilane 1.0
And 0.3 parts of diisopropoxybis (ethylacetoacetato) titanium as a curing catalyst were added and mixed.
It was left under the conditions of 5 ° C. and 60% RH, and the touch dry time was determined. Except that dibutylbis (triethoxysiloxy) tin was used in an amount of 0.2 part as a curing catalyst,
The touch dry time was determined.

Storage Stability After the sample was left in a thermostat at 100 ° C. for 3 days, the viscosity and the above curability were measured to evaluate the change from the normal state.

Electric conductivity of extracted water A solution 90 consisting of 80% by volume of water and 20% by volume of methanol
10 parts of the sample was dispersed in each part, and the mixture was shaken at room temperature for 24 hours.

The results obtained are as shown in Table 1.

[0053]

[Table 1]

As a result, the purified α, ω-bis (methyldimethoxy) polydimethylsiloxane obtained according to the present invention is stable over time as a base polymer of a room temperature-curable polyorganosiloxane composition by a dealcoholization reaction. The curability does not deteriorate during storage. Electrical conductivity measurements also indicate that the ionic catalyst has been removed by treatment with the catalyst adsorbent.

[0055]

According to the present invention, when a polydiorganosiloxane terminated with a silanol group is used as a base polymer of a polydiorganosiloxane composition curable at room temperature, the purified alkoxy is excellent in storage stability and does not deteriorate in curability. A group-terminated polydiorganosiloxane can be obtained in good yield. The alkoxy group-terminated polydiorganosiloxane obtained by the present invention is useful as a base polymer for a fast-curing dealcoholized sealant, a coating agent and the like.

Claims (5)

[Claims] 1. A compound of the general formula (I): Wherein R ¹ represents an unsubstituted or substituted monovalent hydrocarbon group which may be the same or different;
Is a number that brings the viscosity to 10 to 100,000 cP). R is bonded to a silicon atom via an oxygen atom.
² (R ² represents an unsubstituted or substituted alkyl group having 1 to 10 carbon atoms) in the molecule of an unsubstituted or substituted alkoxy group-containing silicon compound having at least two groups represented by the following formula: A method for producing an alkoxy-terminated polydiorganosiloxane, which comprises contacting a reaction product with a composite or powder mixture of zinc oxide and silicon dioxide after reacting in the presence. Wherein unsubstituted or substituted alkoxy group-containing silicon compound has the general formula _{^{(II): R 3 4 -}} a Si (OR 2) a (II) ( wherein, R ² is as described above; R ³ represents an unsubstituted or substituted monovalent hydrocarbon group which may be the same or different; a is an integer of 2 to 4); The production method according to claim 1, wherein 3. The method according to claim 1, wherein the composite of zinc oxide and silicon dioxide is amorphous. 4. The method according to claim 1, wherein the composite of zinc oxide and silicon dioxide is porous. 5. The acidic amine salt is an amine formate salt.
The method according to claim 1.