TW201920216A - Organotitanium compound, moisture-curable composition and molded body having a curing property equivalent to that of a conventional organotitanium compound - Google Patents

Abstract

This invention provides a novel organotitanium compound having a curing property equivalent to that of a conventional organotitanium compound, having excellent curing property of a moisture-curable composition containing the organotitanium compound, giving an elastic solid having high transparency when the moisture-curable composition containing the organotitanium compound without filler is cured, and a moisture-curable composition containing the organotitanium compound as a curing catalyst and curing to give an elastomer a room temperature curable organopolysiloxane composition, and a molded body obtained by curing the composition. The solution of this invention is an organotitanium compound comprising at least one hydrolyzable group represented by the following structural formula (1) in a molecule, wherein, E is an alkylene group having 1 to 4 carbon atoms, and R is an alkyl group having 1 to 4 carbon atoms.

Description

Organic titanium compound, moisture-curable composition, and formed body

The present invention relates to a novel organic titanium compound, a moisture-curable composition using the organic titanium compound as a catalyst, and a molded body obtained by curing the composition.

There is a known organosiloxane composition which is hardened into an elastic solid by a condensation reaction when it comes into contact with moisture in the air. The composition can typically be prepared by mixing a diorganopolysiloxane having a reactive end group, generally a silanol group, and a silane cross-linking agent for diorganopolysiloxane, such as alkoxysilane and acetoxyl. Silane, oxime silane or amine silane. When these materials are exposed to atmospheric moisture at room temperature, they harden to form elastic solids. Among them, the type that releases alcohol and hardens is characterized by no unpleasant odor and no corrosion of metals, so it is preferably used for sealing, adhering, and coating of electrical and electronic equipment. use.

As representative examples of this type, moisture-curable compositions composed of an organopolysiloxane blocked with a hydroxyl group at the end, an alkoxysilane, and an organic titanium compound are disclosed, and an organic polysilicon blocked with an alkoxysilyl group at the end A moisture-hardening composition composed of oxane and alkoxysilane and an organotitanium compound (titanium alkoxide), and a linear organic polysiloxane and alkane closed at the end by an alkoxysilyl group containing silylethyl. A moisture-hardening composition composed of oxysilane and an organic titanium compound (titanium alkoxide), and an organic polysiloxane blocked by a hydroxyl group at the end or an organic polysiloxane and an alkoxy group blocked at the end by an alkoxy group moisture-curable composition composed of -α-silicone compound (Patent Documents 1 to 4: Japanese Patent Publication No. 39-27643, Japanese Patent Application Publication No. 55-43119, Japanese Patent Publication No. 7-39547, (Japanese Patent Application Laid-Open No. 7-331076).

As shown in the above-mentioned representative examples, the use of organic titanium compounds as catalyst systems is well-known. However, when organic titanium compounds are used to make a composition, especially when elasticity is required during curing, there is organic titanium. The compound hydrolyzes during the hardening to become titanium oxide, or a white precipitate is formed in the composition due to the reaction of the organic titanium compound and methoxysilane, thereby causing a problem that the transparency of the elastic solid after the composition is hardened is reduced. Although various researches have been conducted to solve this problem, it is difficult to suppress the formation of a white precipitate during the hardening of the organic titanium compound in the moisture-curing composition in which an existing organic titanium compound is blended. In a moisture-curable composition using an organic titanium compound as a catalyst, a method for obtaining an elastic solid material having high transparency has not yet been known.

Furthermore, when a titanium chelate compound is also used in an organic titanium compound, since it becomes a solid under low temperature conditions in this kind, it is necessary to preliminarily use the titanium chelate compound when manufacturing the moisture-curable composition. Heating and melting also cause manufacturing problems.

As described above, when an organic titanium compound is used as a catalyst for the moisture-curable composition, it is preferable that the elastic solid material obtained when the moisture-curable composition is cured without a filler has high transparency. An organic titanium compound having the same hardenability as the conventional organic titanium compound. Furthermore, when a certain titanium chelate is selected as the organic titanium compound, it is expected to develop an organic titanium compound that does not become a solid state even at a low temperature state and is easy to handle in production.
In addition, as the prior art related to the present invention, the following documents can be cited together with the aforementioned documents.
[Prior technical literature]
[Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 39-27643
[Patent Document 2] Japanese Patent Laid-Open No. 55-43119
[Patent Document 3] Japanese Patent Publication No. 7-39547
[Patent Document 4] Japanese Patent Application Laid-Open No. 7-331076
[Patent Document 5] Japanese Patent Publication No. 2012-511607

[Problems to be Solved by the Invention]

The present invention has been made in view of the above circumstances, and an object thereof is to provide a moisture-curable composition having the same hardenability as that of a conventional organic titanium compound, and which has good hardenability, and is When the moisture-curable composition without a filler (filler) is cured, a novel organic titanium compound that imparts an elastic solid with high transparency, and an elastomer that contains the organic titanium compound as a curing catalyst and is cured. A moisture-curable composition such as a room-temperature-curable organic polysiloxane composition, and a molded body obtained by curing the composition.

[Means to solve the problem]

The present inventors conducted intensive studies in order to achieve the above-mentioned object, and as a result, found that the use of an organic titanium compound containing at least one hydrolyzable group represented by the following structural formula (1) as a moisture-curable composition is used in the molecule. The catalyst has the same hardenability as the organic titanium compound used in the past, and can be obtained at the time of hardening in a moisture-curable organic polysiloxane composition containing no filler material using the above-mentioned organic titanium compound. The elastic solid has high transparency, and thus completed the present invention.

(In the formula, E is an alkylene group having 1 to 4 carbon atoms, and R is an alkyl group having 1 to 4 carbon atoms.)

Therefore, the present invention provides the following organic titanium compound, a moisture-curable composition containing the compound, and a formed body obtained by curing the composition.
[1]
An organic titanium compound containing at least one hydrolyzable group represented by the following structural formula (1) in a molecule.

(In the formula, E is an alkylene group having 1 to 4 carbon atoms, and R is an alkyl group having 1 to 4 carbon atoms.)
[2]
The organic titanium compound according to [1], which is represented by any one of the following general formulae (2), (3), (4), and (5).

[Wherein R ¹ is a monovalent hydrocarbon group having 1 to 6 carbon atoms; R ² is represented by the following general formula (6)

(In the formula, E is an alkylene group having 1 to 4 carbon atoms, and R is an alkyl group having 1 to 4 carbon atoms.)
Trialkylsilyl-substituted alkyl groups shown; x1 is an average of 0 to 3, y1 is an average of 1 to 4, and x1 + y1 is 4; x2 is an average of 1 to 3, and y2 is an average of 1 ～ 3, and x2 + y2 is 4]
[3]
The organic titanium compound such as [1] or [2] is used as a curing catalyst for a moisture-curable composition.
[4]
A moisture-curable composition containing an organic titanium compound such as [3], and imparting an elastomer by moisture curing.
[5]
The moisture hardening composition as in [4], which contains: a polymer material having at least two hydroxyl groups or alkoxy groups bonded to silicon in a molecule, and an organic oxysilane curing agent.
[6]
For example, the moisture hardening composition of [5], in which a polymer material having more than two hydroxyl groups or alkoxy groups bonded to silicon in the molecule is a polymer material having more than two hydroxyl groups or silicon bonds to the molecule Organic polysiloxanes of alkoxy group.
[7]
The moisture-curable composition according to [5] or [6], which further contains a filler.
[8]
An electric and electronic part, which is a hardened product having the composition according to any one of [4] to [7].
[9]
A sealant for construction, which is composed of a hardened product of the composition described in any one of [4] to [7] above.
[10]
An automotive oil seal is composed of a hardened product of the composition described in any one of [4] to [7] above.

When the above-mentioned organic titanium compound is used as a curing catalyst for the moisture-curable composition, the organic titanium compound has the same hardenability as the conventional organic titanium compound, and the hardenability of the moisture-curable composition formulated with the organic titanium compound can be good.
Furthermore, a room-temperature-curing organic compound using the above-mentioned organic titanium compound, an organic polysiloxane having at least two hydroxyl groups or alkoxy groups bonded to silicon in the molecule, and an organic oxysilane curing agent without a filler is used. In the case of moisture-curable compositions such as polysiloxane compositions, the compatibility of the polyorganosiloxane component with the hydrolyzable group of the novel organic titanium compound is different depending on the similar structure of the organopolysiloxane. , And can obtain elastic solid objects with high transparency. The elastic solid material of this moisture-curable composition is preferably used for electric and electronic parts and the like from the viewpoint of excellent optical characteristics.
In addition, by including a filler in the moisture-curable composition using the above-mentioned organic titanium compound, viscosity adjustment or fluidity adjustment can be performed in the moisture-curable composition in an uncured state. In the elastic solid material obtainable when the moisture-curable composition is hardened, mechanical properties and chemical resistance can be improved, and therefore it can be preferably used as a sealant for construction or an oil seal for automobiles.

[Effect of the invention]

The organic titanium compound of the present invention can be used as a catalyst for a moisture-curable composition having the same hardenability as conventional organic titanium compounds. In addition, the organic titanium compound of the present invention contains two or more silicon compounds in the molecule. Moisture-curable composition with bonded hydroxyl group or alkoxy group, organopolysiloxane, and organooxysilane curing agent, and without blending filler. It is a highly transparent elastic solid material when cured. .

The organic titanium compound of the present invention contains at least one hydrolyzable group containing a structure similar to an organopolysiloxane in the molecule, that is, a hydrolyzable group represented by the following structural formula (1), thereby becoming A novel organic titanium compound that is a catalyst having a moisture-curable composition that has the same curability as a conventional organic titanium compound.

(In the formula, E is an alkylene group having 1 to 4 carbon atoms, and R is an alkyl group having 1 to 4 carbon atoms.)

That is, the novel organic titanium compound of the present invention is the following organic titanium compound, which is characterized in that it contains at least one trialkylsilyl group in the molecule as a hydrolyzable group represented by the aforementioned structural formula (1).

The organic titanium compound may be a titanium alkoxide represented by the following general formula (2) and a titanium chelate represented by the following general formula (3) with ethyl acetoacetate as a ligand, and the following The titanium chelate using acetamidine pyruvate as a ligand represented by general formula (4) and the titanium chelate using octanediol ester as a ligand represented by general formula (5) below .

[Wherein R ¹ is a monovalent hydrocarbon group having 1 to 6 carbon atoms; R ² is represented by the following general formula (6)

(Where E and R are as described above)
Trialkylsilyl-substituted alkyl groups shown; x1 is an average of 0 to 3, y1 is an average of 1 to 4, and x1 + y1 is 4; x2 is an average of 1 to 3, and y2 is an average of 1 ～ 3, and x2 + y2 is 4]

These novel organic titanium compounds have been developed for users who use curing catalysts as moisture-curable compositions. The moisture-curable composition containing these novel organic titanium compounds can be hardened by moisture to form an elastomer. The moisture-curable composition is generally obtained by containing the above-mentioned organic titanium compound in a mixture containing a polymer material having two or more hydroxyl groups or alkoxy groups bonded to silicon in a molecule, And organic oxysilane curing agents. The moisture-curable composition obtained in this way is hardened by the moisture in the air, and in the case of a moisture-curable organic polysiloxane composition containing no filler, elasticity with high transparency can be obtained. A solid object is also preferably used for electric and electronic parts and the like because of its excellent optical characteristics. In addition, when the moisture-curable composition contains a filler, in addition to viscosity adjustment or fluidity adjustment when it is not cured, an elastic solid material obtainable when the moisture-curable composition is cured. Since mechanical properties and chemical resistance can be improved, it can be preferably used as a sealant for construction or an oil seal for automobiles.

The present invention is explained in detail below.

[New organic titanium compound]
The organic titanium compound of the present invention is an organic titanium compound containing at least one hydrolyzable group represented by the following structural formula (1) in the molecule.

(In the formula, E is an alkylene group having 1 to 4 carbon atoms, and R is an alkyl group having 1 to 4 carbon atoms.)

Here, in the structural formula (1), E is an alkylene group having 1 to 4 carbon atoms, and more preferably methylene, ethylidene, or propylene (trimethylene, methylethylidene), or the like. It is selected from the group consisting of 1 to 3 carbon atoms, and each E may be the same or different.
R is an alkyl group having 1 to 4 carbon atoms, and examples thereof include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, secondary butyl, and tertiary butyl. The group is more preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, or the like, and is selected from the group consisting of 1 to 3 carbon atoms, and each R may be the same or different.

Since the organic titanium compound of the present invention contains a hydrolyzable group represented by the above-mentioned structural formula (1) in the molecule, when a catalyst that is a moisture-curable organic polysiloxane composition containing no filler is used, The trialkylsilyl group in the hydrolyzable group of the organic titanium compound improves the dispersibility in the organopolysiloxane as a main agent, and an elastic solid material having high transparency can be obtained.

Specific examples of the hydrolyzable group represented by the structural formula (1) include trimethylsilylmethoxy, triethylsilylmethoxy, tripropylsilylmethoxy, and tributyl. Silylmethoxy, trimethylsilylethoxy, triethylsilylethoxy, tripropylsilylethoxy, tributylsilylethoxy, trimethylsilylpropoxy , Triethylsilylpropoxy, tripropylsilylpropoxy, tributylsilylpropoxy, trimethylsilylbutoxy, triethylsilylbutoxy, tripropylsilyl Butyloxy, tributylsilylbutoxy, triisopropylsilylmethoxy, triisopropylsilylethoxy, triisopropylsilylpropoxy, triisopropylsilyl Butoxy, tris (tertiary butyl) silylmethoxy, tris (tertiary butyl) silylethoxy, tris (tertiary butyl) silylpropoxy, tris (tertiary butyl) Silyl butoxy and the like. Among these, particularly preferred is the structural formula (1) in which E is methylene, ethylene, and R is methyl and ethyl, that is, trimethylsilylmethoxy, triethylsilylmethoxy , Trimethylsilylethoxy, triethylsilylethoxy.

The organic titanium compound containing at least one hydrolyzable group represented by the structural formula (1) in the molecule may be any of the following general formulae (2), (3), (4), and (5) The organic titanium compound shown in item 2.

[Wherein R ¹ is a monovalent hydrocarbon group having 1 to 6 carbon atoms; R ² is represented by the following general formula (6)

(Where E and R are as described above)
Trialkylsilyl-substituted alkyl groups shown; x1 is an average of 0 to 3, y1 is an average of 1 to 4, and x1 + y1 is 4; x2 is an average of 1 to 3, and y2 is an average of 1 ～ 3, and x2 + y2 is 4]

Here, in the general formula (2), R ¹ is a monovalent hydrocarbon group having 1 to 6 carbon atoms. Examples of the monovalent hydrocarbon group include methyl, ethyl, propyl, isopropyl, butyl, and isobutyl. Alkyl, secondary butyl, tertiary butyl, pentyl, hexyl and other alkyl groups, cyclohexyl and other cycloalkyl groups, phenyl and other aryl groups, among these, isopropyl or methyl is particularly preferred A monovalent straight-chain aliphatic hydrocarbon group (straight-chain alkyl group) having 1 to 4 carbon atoms like ethyl, propyl, and butyl.

In the general formulae (2) to (5), R ² is a trialkylsilyl-substituted alkyl group represented by the following general formula (6).

(In the formula, E and R are the same as those described above, and the same examples as those described above can be exemplified.)

Since the organic titanium compound shown above contains a hydrolyzable group containing a trialkylsilyl group represented by the general formula (6) in the molecule, the general formula (2), (3), (4) Or when the organic titanium compound shown in (5) uses a catalyst that is a moisture-curable organic polysiloxane composition containing no filler, the trialkylsilyl group among the hydrolyzable groups improves the organic polymer Dispersibility in siloxane, and elastic solids with high transparency can be obtained.

Specific examples of the trialkylsilyl-substituted alkyl group represented by the general formula (6) include trimethylsilylmethyl, triethylsilylmethyl, and tripropylsilylmethyl. , Tributylsilylmethyl, trimethylsilylethyl, triethylsilylethyl, tripropylsilylethyl, tributylsilylethyl, trimethylsilylpropyl, trimethylsilyl Ethylsilylpropyl, tripropylsilylpropyl, tributylsilylpropyl, trimethylsilylbutyl, triethylsilylbutyl, tripropylsilylbutyl, tributyl Silylbutyl, triisopropylsilylmethyl, triisopropylsilylethyl, triisopropylsilylpropyl, triisopropylsilylbutyl, tri (tertiarybutyl) silyl Methyl, tri (tertiary butyl) silylethyl, tri (tertiary butyl) silylpropyl, tri (tertiary butyl) silylbutyl, and the like. Among these, the general formula (6) in which E is methylene and ethyl, and R is methyl and ethyl, that is, trimethylsilylmethyl, triethylsilylmethyl, triethyl Methylsilylethyl, triethylsilylethyl.

In the general formula (2), x1 is an average value of 0 to 3, y1 is an average value of 1 to 4, and x1 + y1 is 4. Here, a more preferable value of x1 and y1 is that x1 is an average value of 0 to 2, and y1 is an average value of 2 to 4, that is, a trialkylsilicon represented by general formula (6) containing R ² . The more hydrolyzable groups are, the harder the catalyst that is used as the moisture-curable organic polysiloxane composition containing no filler, the more elastic solids with high transparency can be obtained.
In the general formulae (3), (4), and (5), x2 is an average value of 1 to 3, y2 is an average value of 1 to 3, and x2 + y2 is 4. Here, a more preferable value of x2 and y2 is that x2 is an average value of 1 to 2, and y2 is a range of an average value of 2 to 3. The reason is as described above.

In the organic titanium compound represented by the general formula (2), (3), (4) or (5), the organic titanium catalyst represented by the general formula (2) is titanium alkoxide, and in addition, the general formula (3) The organic titanium catalyst shown is a titanium chelate with ethyl acetate [C ₆ H ₉ O ₃ (that is, C (= O) CHC (= O) OC ₂ H ₅ )] as a ligand The organic titanium catalyst represented by the general formula (4) is acetamidine pyruvate [C ₅ H ₇ O ₂ (that is, CH ₃ C (= O) CHC (= O) CH ₃ )] as The titanium chelate of the ligand uses the organic titanium catalyst represented by the general formula (5) as the octanediol ester [C ₈ H ₁₇ O ₂ (that is, HO (CH ₂ ) ₈ O)] as the coordination Based titanium chelate. These organic titanium compounds can be used alone or in combination of two or more organic titanium compounds having different structures. In addition, these partial hydrolysates are also targeted.

[Manufacturing method of novel organic titanium compound]
The organic titanium compound represented by the general formula (2) can be obtained by reacting tetrachlorotitanium with an alcohol having a skeleton of the structural formula (1).
Examples of the alcohol having a skeleton of the structural formula (1) include those represented by the following formula (7).

(In the formula, E and R are the same as those described above, and the same examples as those described above can be exemplified.)

The reaction ratio of titanium tetrachloride to an alcohol having a skeleton of the structural formula (1) is 1 mole of the alcohol having the skeleton of the structural formula (1) represented by the formula (7) relative to 1 mole of the tetrachlorotitanium. By reacting the amount of 10 mol or less, an organic titanium catalyst represented by the general formula (2) can be obtained. In addition, when the alcohol represented by the formula (7) having a skeleton of the structural formula (1) remains, it is preferable to remove the remaining portion of the alcohol under reduced pressure.

The above reaction conditions are not particularly specified, but the reaction temperature is preferably from 0 to 100 ° C, and more preferably from 10 to 80 ° C. However, when the reaction is intense, the reaction solution must be reacted at a temperature at which the reaction solution does not solidify. In addition, when the reaction between tetrachlorotitanium and the alcohol represented by the formula (7) having a skeleton of the structural formula (1) is extremely slow. If it has a temperature below the boiling point of the alcohol represented by the formula (7) having a skeleton of the structural formula (1), the reaction may be performed at a temperature above the above-mentioned temperature range. In the reaction, since titanium tetrachloride and the reaction product are hydrolyzed by moisture, the reaction must be performed under conditions that block moisture. Therefore, it becomes necessary to perform the reaction in an environment where moisture is blocked by means such as nitrogen sealing.
The reaction time is not particularly specified, and the progress of the reaction can be tracked by means of gas chromatography analysis, etc., for the reaction solution of tetrachlorotitanium and the alcohol represented by the formula (7) having a skeleton of the structural formula (1) While confirming that the alcohol having the skeleton of the structural formula (1) represented by the formula (7) decreases, the end time of the reaction is determined. At this time, when the reaction time between tetrachlorotitanium and the alcohol represented by the formula (7) having a skeleton of the structural formula (1) is too short, there is a case where the tetrachlorotitanium and the skeleton having the structural formula (1) have an expression The yield of the reaction product of the alcohol shown in (7) decreases. In addition, on the contrary, when the reaction time of titanium tetrachlorotitanium and the alcohol represented by formula (7) having a skeleton of structural formula (1) is too long, the probability of moisture being mixed in the reactor is increased, and the reaction is generated. There is a high possibility that the hydrolysis of the product and the increase in oligomers cause a loss such as an increase in viscosity.

The organic titanium compound represented by the general formula (2) can also be obtained by transesterification of titanium alkoxide such as titanium tetraisopropoxide with an alcohol having a skeleton of the structural formula (1). In the production of the transesterification reaction based on titanium alkoxide and the corresponding alcohol, since the reaction is reversible, it is necessary to synthesize the target while removing the alcohol produced from the titanium alkoxide. There are many kinds of removal steps. Generally, it is known to carry out the reaction at a temperature above the boiling point of the alcohol produced from titanium alkoxide, or to remove the alcohol produced from titanium alkoxide under vacuum.

Here, the titanium alkoxide is exemplified by Ti [OR ¹ ] ₄ (wherein R ¹ is the same as above).
Examples of the alcohol having a skeleton of the structural formula (1) include those represented by the formula (7).

The reaction ratio of the titanium alkoxide to the alcohol having a skeleton of the structural formula (1) is 1 mole of the alcohol having the skeleton of the structural formula (1) represented by the formula (7) to the titanium alkoxide. By the amount of 10 mol or less, an organic titanium catalyst represented by the general formula (2) can be obtained. In addition, when the alcohol represented by the formula (7) having a skeleton of the structural formula (1) remains, it is preferable to remove the remaining portion of the alcohol under reduced pressure.

The reaction conditions for the above-mentioned transesterification reaction are not particularly specified, but the reaction temperature is preferably 40 to 120 ° C, and more preferably the transesterification reaction is performed at a temperature range of 60 to 100 ° C. This is because the titanium alkoxide reacts with an alcohol represented by the formula (7) having a skeleton of the structural formula (1), and the alcohol generated from the titanium alkoxide needs to be removed. Here, when the reaction of the titanium alkoxide with the alcohol represented by the formula (7) having a skeleton of the structural formula (1) is extremely slow, if the temperature is below the boiling point of the alcohol having the skeleton of the structural formula (1), The reaction may be performed at a temperature above the above-mentioned temperature range. In the reaction, since the titanium alkoxide and the reaction product are hydrolyzed by moisture, the reaction must be performed under conditions that block moisture. Therefore, it becomes necessary to perform the reaction in an environment where moisture is blocked by means such as nitrogen sealing.
The reaction time is not particularly specified, and the reaction progress of the reaction solution of titanium alkoxide and the alcohol represented by the formula (7) having a skeleton of the structural formula (1) can be tracked by means such as gas chromatography analysis. While confirming that the alcohol having the skeleton of the structural formula (1) represented by the formula (7) decreases, the end time of the reaction is determined. At this time, when the transesterification reaction time of the titanium alkoxide and the alcohol having a skeleton of the structural formula (1) is too short, there is a case where the titanium alkoxide and the skeleton having the structural formula (1) are represented by formula (7). The yield of the reaction product of the alcohol is reduced. In addition, on the contrary, when the reaction time of titanium alkoxide and the alcohol represented by formula (7) having a skeleton of structural formula (1) is too long, the probability of moisture being mixed in the reactor is increased, and the reaction is generated. There is a high possibility that the hydrolysis of the product and the increase in oligomers cause a loss such as an increase in viscosity.

The organic titanium compound represented by the general formula (3), (4), or (5) can be a compound that becomes a ligand, that is, ethyl acetate [C ₆ H ₁₀ O ₃ (that is, CH ₃ C (= O) CH ₂ C (= O) OC ₂ H ₅ )] is acetamidine [C ₅ H ₈ O ₂ (that is,
CH ₃ C (= O) CH ₂ C (= O) CH ₃ )], in the general formula (5) is octanediol [C ₈ H ₁₈ O ₂ (that is, HO (CH ₂ ) ₈ OH)] reaction The titanium alkoxide represented by the general formula (2) synthesized above is obtained. When the ligand is reacted with the titanium alkoxide represented by the general formula (2), the alcohol bonded to the titanium alkoxide is removed. Even if the detached alcohol is not removed, the quality will not be reduced, but because the purity of the organic titanium compound is reduced, the produced alcohol is more preferably removed by the above-mentioned removal step.

Here, the reaction ratio of the titanium alkoxide represented by the general formula (2) with ethyl acetate, ethyl acetate, or octanediol is 1 mole relative to the titanium alkoxide represented by the general formula (2). In order to perform the reaction, ethyl acetate, ethyl acetate, or octanediol must be added in an amount of less than 3 moles. Here, when ethyl acetate, ethyl acetate or octanediol is added in excess of 3 moles, ethyl acetate, ethyl acetate or octanediol becomes excessive, which is not preferable.

The reaction conditions of the titanium alkoxide represented by the general formula (2) with ethyl acetate, ethyl acetate, or octanediol are not particularly specified, but the reaction temperature is preferably 10 to 140 ° C, and more preferably 20 The reaction is carried out in a temperature range of -120 ° C. Here, when the reaction of titanium alkoxide represented by general formula (2) with ethyl acetate, ethyl acetate, or octanediol is extremely slow, if the temperature is below the boiling point of the compound that becomes a ligand, The reaction may be performed at a temperature above the above-mentioned temperature range. In the reaction, since the titanium alkoxide and the reaction product represented by the general formula (2) are hydrolyzed by moisture, the reaction must be performed under conditions that block moisture. Therefore, it becomes necessary to perform the reaction in an environment where moisture is blocked by means such as nitrogen sealing.
The reaction time is not particularly specified. When the reaction solution of titanium alkoxide shown in general formula (2) and ethyl acetate, ethyl acetate, or octanediol is traced by means of gas chromatography analysis and the like In the progress of the reaction, as the alcohols bound to the titanium alkoxide by the reaction by-products increase and the number of compounds that become ligands decreases, the time at which either of the peak areas hardly changes can be regarded as the end of the reaction. time. At this time, when the reaction time of the titanium alkoxide represented by the general formula (2) with ethyl acetate, ethylacetone, or octanediol is too short, the alkoxide represented by the general formula (2) may be oxidized. The yield of the reaction product of titanium with ethyl acetate, ethyl acetate, or octanediol is reduced. In addition, on the contrary, when the reaction time of the titanium alkoxide represented by the general formula (2) with ethyl acetate, ethyl acetate, or octanediol is too long, the probability of moisture being mixed in the reactor increases. , The reaction product is hydrolyzed, the oligomer is increased, and the possibility of loss such as an increase in viscosity increases.

[Usage method of novel organic titanium compound]
The above-mentioned novel organic titanium compound can be used for various applications such as coatings and surface modification. However, this characteristic is particularly exhibited when a curing catalyst that is a moisture-curable composition is used. The reason for this is that the trialkylsilyl group in the hydrolyzable group is used in the moisture-curable organic polysiloxane composition having the same hardenability as the conventional organic titanium compound and containing no filler. , Improve the dispersibility in organopolysiloxane, so it can get elastic solid with high transparency when hardened. Furthermore, in the past, when a certain titanium chelate compound was selected as the organic titanium compound to be used, it was difficult to handle in production because it was in a solid state at a low temperature. However, the organic titanium compound of the present invention is It contains a trialkylsilyl group and can maintain liquid properties even at low temperatures. As a result, it is an organic titanium compound that can maintain the same hardenability as conventional organic titanium compounds and is easy to handle.

[Application of Novel Organic Titanium Compounds to Moisture-hardening Compositions]
The organic titanium compound of the present invention is used as a curing catalyst for a moisture-curable composition that imparts elastomer properties by moisture curing. The moisture-curable composition can use the organic titanium compound of the present invention in a molecule having two or more silicon-bonded hydroxyl groups (silanol groups) or alkoxy-containing silicon groups (such as trialkoxy) (Siliconyl, dialkoxyalkylsilyl, alkoxydialkylsilyl, etc.) polymer materials, preferably having 2 or more hydroxyl groups (silanol) bonded to silicon in the molecule or Organic polysiloxanes containing alkoxy-containing silyl groups (e.g. trialkoxysilyl groups, dialkoxyalkylsilyl groups, alkoxydialkylsilyl groups, etc.) Silanol-based or alkoxy-containing silyl-blocked linear diorganopolysiloxane) and a mixture of organic oxysilane curing agents.

A polymer material having two or more silicon-bonded hydroxyl groups or alkoxy groups in the molecule, preferably having two or more silicon-bonded hydroxyl groups (silanol groups) or alkoxy-containing silicon in the molecule Organopolysiloxanes such as trialkoxysilyl, dialkoxyalkylsilyl, alkoxydialkylsilyl, etc., especially when used as a moisture-curable composition without fillers From the viewpoint of dispersibility with the above-mentioned organic titanium compound, it is preferably used in molecules having two or more hydroxyl groups (silanol groups) bonded to silicon or silicon groups containing alkoxy groups (e.g. Organic polysiloxanes (especially alkoxysilyl groups, dialkoxyalkylsilyl groups, alkoxydialkylsilyl groups, etc.) Diblocked linear diorganopolysiloxane).

Examples of the organic polysiloxane include organic polysiloxanes represented by the following general formulae (8) to (12).

(Wherein R ³ is an unsubstituted or substituted monovalent saturated hydrocarbon group having 1 to 10 carbon atoms, a is 10 or more, preferably 20 to 2,000, and more preferably an integer of 30 to 1,200)

(Wherein a is as described above; R ⁴ is methyl or ethyl, preferably methyl; R ⁵ is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms; Y is an oxygen atom or a carbon atom 1 to 5 alkylene, N is independently an integer of 0 or 1)

(Wherein R ⁴ , R ⁵ , a, Y, and N are as described above; Z is a methyl group or an alkenyl group having 2 to 5 carbon atoms)

[In the formula, R ⁴ , R ⁵ , a, Y, and N are as described above. In addition, b is 1 or more, preferably an integer of 1 to 10. In addition, R ⁶ contains the following general formula:

(Wherein R ⁴ , R ⁵ , Y, and N are as described above)
Hydrolysable group shown]

(Wherein R ⁴ , R ⁵ , R ⁶ , a, b, Y, Z, N are as described above)

In the formula (8), R ³ is an unsubstituted or substituted monovalent saturated hydrocarbon group having 1 to 10 carbon atoms. Specific examples include methyl, ethyl, propyl, isopropyl, butyl, and isobutyl. , Tertiary butyl, pentyl, neopentyl, hexyl, octyl, etc., cycloalkyl, etc., or a part or all of the hydrogen atoms of these groups are subjected to fluorine, chlorine, bromine, etc. Examples of the halogen atom, cyano group, and the like that are substituted include chloromethyl, chloropropyl, bromoethyl, trifluoropropyl, and cyanoethyl, and methyl, ethyl, and phenyl are preferred.
In the formulae (9) to (12), R ⁵ is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms. Specific examples include methyl, ethyl, propyl, isopropyl, butyl, Isobutyl, tertiary butyl, pentyl, neopentyl, hexyl, octyl and other alkyl groups, cyclohexyl and other cycloalkyl groups, vinyl, allyl, and propenyl alkenyl groups, phenyl, Aryl groups such as tolyl, xylyl, naphthyl, aralkyl groups such as benzyl, phenethyl, phenylpropyl, etc., or a part or all of the hydrogen atoms of these groups are subjected to fluorine, chlorine, bromine, etc. Examples of the halogen atom, cyano group, and the like that are substituted include chloromethyl, chloropropyl, bromoethyl, trifluoropropyl, and cyanoethyl, and methyl, ethyl, and phenyl are preferred.
Y is an oxygen atom or an alkylene group having 1 to 5 carbon atoms. Examples of the alkylene group include methylene, ethylidene, propylene (trimethylene, methylethylidene), and butylene (tetramethylene). Methylene, methylphenyl, etc.), and Y is preferably an oxygen atom, methylene, ethylidene, or methylidene.
Z is a methyl group or an alkenyl group having 2 to 5 carbon atoms. Examples of the alkenyl group include vinyl, allyl, propenyl, butenyl, and pentenyl. Z is preferably methyl or vinyl.

A polymer material having two or more silicon-bonded hydroxyl groups or an alkoxy-containing silicon group in the molecule (especially a linear chain having both ends of the molecular chain closed by the silanol group or the alkoxy-containing silicon group) The viscosity of diorganopolysiloxane) at 23 ° C is preferably 50 to 200,000 mPa‧s, and particularly preferably 100 to 50,000 mPa‧s. When the viscosity is too low, a large amount of time may be required until curing, and the preservation property may be reduced. When the viscosity is too high, coatability or defoaming property may be reduced, and workability may be deteriorated. The viscosity can be measured by a rotary viscometer.

Examples of the organic oxysilane curing agent used in the moisture-curable composition include an organic oxysilane such as an alkoxysilane represented by the following general formula (13). Here, the organooxysilane curing agent is a partially hydrolyzed condensate (partially hydrolyzed and condensed) of the organooxysilane of the general formula (13) (ie, it has at least two, preferably three or more residual hydrolyzability in the molecule). Based organosiloxane oligomers).

(Wherein R ⁷ is an alkyl group having 1 to 6 carbon atoms, a vinyl group or a halogen-substituted alkyl group, and R ⁸ is an alkyl group having 1 to 4 carbon atoms, an alkenyl group, or an alkoxyalkyl group; n is an integer from 2 to 4)
The organic oxysilane curing agent (the above-mentioned organic oxysilane or the partially hydrolyzed condensate) is used as a crosslinking agent when curing a moisture-curable composition.

R ^{7 in} the general formula (13) may be the same or different alkyl group having 1 to 6 carbon atoms, a vinyl group, or a halogen-substituted alkyl group. Specific examples include methyl, ethyl, propyl, and butyl. , Pentyl, hexyl, vinyl, chloromethyl, chloropropyl, bromoethyl, trifluoropropyl and the like, with methyl being particularly preferred. R ⁸ is an alkyl group, alkenyl group, or alkoxyalkyl group having 1 to 4 carbon atoms. Specific examples include methyl, ethyl, propyl, butyl, propenyl, methoxymethyl, and methoxyethyl. , Ethoxymethyl, ethoxyethyl and the like, preferably methyl or ethyl, more preferably methyl. n is an integer of 2 to 4, preferably 3 or 4, and particularly preferably 3.

Specific examples of the organic oxysilane curing agent include ethyl silicate, propyl silicate, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, and Tris (methoxyethoxy) silane, vinyltris (methoxyethoxy) silane, methyltripropyleneoxysilane, etc., and partially hydrolyzed condensates thereof. Among them, methyltrimethoxysilane and vinyltrimethoxysilane are particularly preferred.

The organic oxysilane curing agent may be any of the above-mentioned organic oxysilane and the siloxane obtained by partial hydrolysis and condensation. The siloxane has at least two, especially three, silicon atoms. The above alkoxy group may be any of linear, branched, or cyclic, and these are not limited to one type, and two or more types may be used.

The amount of the organic oxysilane curing agent is preferably 0.1 to 100 parts by mass based on 100 parts by mass of a polymer material having two or more silicon-bonded hydroxyl groups (silanol groups) or alkoxy-containing silicon groups in the molecule. 30 parts by mass, particularly preferably 0.5 to 10 parts by mass. When the amount of the organooxysilane curing agent is too small, the obtained composition may thicken or harden with time, and when it is excessive, it may take a large amount of time until it is hardened. The mechanical properties will deteriorate.

In the above moisture-curable composition, the compounding amount of the organic titanium compound of the present invention is higher than that having two or more silicon-bonded hydroxyl groups (silanol groups) or alkoxy-containing silicon groups in the molecule. The molecular material is 100 parts by mass, preferably 0.1 to 30 parts by mass, more preferably 0.5 to 15 parts by mass, and particularly preferably 1 to 5 parts by mass. When the compounding amount of the organic titanium compound is too small, the hardenability may change with time, and in the worst case, it may become unhardened. When it is too much, the deep hardenability may decrease and the surface hardenability may be too fast. The intended moisture-curable composition cannot be obtained.

The organic titanium compound shown above is used in a mixture of two or more silicon-bonded hydroxyl groups (silanol groups) or alkoxy-containing silicon groups in a molecule, and an organic oxysilane curing agent. The moisture-curable organic polysiloxane composition, from the point of view that the hydrolyzable group of the novel organic titanium compound is based on the similar structure of the organic polysiloxane, improves the compatibility with the polysiloxane component. In the case of an agent, an elastic solid material having high transparency can be obtained. The elastic solid of such a moisture-curable composition can be preferably used for electric and electronic parts and the like from the viewpoint of excellent optical characteristics.

In addition, the filler may be contained in the moisture-curable composition as required, and by containing the filler, viscosity or fluidity may be adjusted in the moisture-curable composition in an uncured state. In the elastic solid obtained by curing the moisture-curable composition containing the filler, the mechanical properties or chemical resistance can be improved, so it can be preferably used as a sealant for construction or an oil seal for automobiles. .

As the filler used, generally known ones can be used. Examples include fumed silica, wet silica, sedimentary silica, diatomaceous earth, heavy calcium carbonate, colloidal calcium carbonate, titanium oxide, carbon black, talc, aluminum hydroxide, and aluminum oxide. , Magnesium oxide, zinc carbonate, zinc oxide, etc., can be used alone or in combination of two or more. Among them, heavy calcium carbonate, colloidal calcium carbonate, aerosol silica, precipitated silica, aluminum hydroxide, aluminum oxide, zinc carbonate, and zinc oxide are preferably used. The surface treatment of the filler is not limited. Examples of the surface treatment agent used for the surface treatment include dichlorodimethylsilane, chlorotrimethylsilane, dimethylpolysiloxane, octamethylcyclotetrasiloxane, and hexamethyldisilazane. Organic silicon compounds, or fatty acids, resin acids, sulfonic acids, paraffin, etc.

The amount used when preparing the filler is preferably 0.1 to 500 parts by mass relative to 100 parts by mass of the polymer material having two or more silicon-bonded hydroxyl groups (silanol groups) or alkoxy-containing silicon groups in the molecule. Parts, particularly preferably 0.5 to 200 parts by mass.

An arbitrary component can be blended in the moisture-curable composition. Examples of the optional components include plasticizers for terminal unreactive polymers for adjusting the physical properties of rubber, pigments or dyes for coloring, metal powders for imparting conductivity or heat dissipation, and improvement of extrusion. Workability viscosity modifiers, UV absorbers, mildew inhibitors, heat resistance improvers, flame retardants, etc., and various other additives can also be added.

The moisture-curable composition of the present invention can be obtained by uniformly mixing the above-mentioned respective components in a dry environment and further mixing the predetermined amounts of the above-mentioned various additives therein. In addition, although the moisture-curable composition of the present invention is hardened by being left at room temperature (23 ° C ± 10 ° C), the molding method, curing conditions, and the like may be generally known methods depending on the type of the composition. ,condition.

The moisture-curable composition of the present invention thus obtained is rapidly cured at room temperature by moisture in the air to form heat resistance, weather resistance, low-temperature characteristics, and adhesion to various substrates, especially metals. Hardened rubber elastomer with excellent properties. In addition, the moisture-curable composition of the present invention is particularly excellent in storage stability and hardenability. For example, even if it is exposed to the air after 12 months of storage, it rapidly hardens to impart a hardened material having excellent physical properties as described above. . In particular, no toxic or corrosive gas will be released during hardening, and no rust will be formed on the surface on which the composition is applied. In particular, this moisture-curable organic polysiloxane composition is excellent in transparency when no filler is blended, so it is useful as a coating material, an insulating material, and an adhesive for electrical and electronic parts. It can be used as a sealant, coating agent, coating agent, release treatment agent, and fiber treatment agent for various substrates. Specific examples include electrical and electronic parts having a cured product of the moisture-curable composition of the present invention. A construction sealant composed of a hardened product of the composition, an automobile oil seal composed of a hardened product of the composition, and the like. Here, the term "transparent" means that the person who is located on the opposite side or the inside of the object is clearly seen, and the light transmittance is not significantly reduced due to the difference in wavelength.

[Example]

Hereinafter, the present invention will be specifically described by way of synthesis examples, examples, and comparative examples, but the following examples are not intended to limit the present invention. In addition, in the examples, the viscosity is a measurement value measured at 23 ° C based on a rotary viscometer, and "part" and "%" represent "mass part" and "mass%", respectively. The metal content of the organic titanium compound is an organic titanium compound obtained by firing. The mass change is measured and determined by the following formula.
Metal content (%) = 100 × 0.5994 × (((mass after firing)-(mass of container)) / ((mass before firing)-(mass of container)))

[Synthesis Example 1]
28.4 g (0.1 mol) of tetraisopropyl titanate was placed in a 300 ml four-necked flask equipped with a thermometer, an ester trap, a cooling tube, and a dropping funnel, which was sealed with dry nitrogen, and was dropped while stirring. Trimethylsilyl methanol 41.7 g (0.4 mole). The reaction was then carried out at 60 ° C for 8 hours under dry nitrogen aeration. After analyzing the transparent liquid refluxed into the ester trap by gas chromatography, it was confirmed that most of the isopropanol refluxed. The four-necked flask was then set to a vacuum condition, and the remaining alcohol contained in the system was removed at 60 ° C for one hour. A transparent liquid remained in the flask, and about 41 g of an organic titanium compound (1) was obtained (in the general formula (2), R ¹ = isopropyl group, R ² = methyl group substituted with trimethylsilyl group, x1 = 0, y1 = 4) (yield; about 89.1%). The metal content of the obtained organic titanium compound (1) was 11.1% (theoretical value; 10.4%).

[Synthesis Example 2]
28.4 g (0.1 mol) of tetraisopropyl titanate was charged into a 300 ml four-necked flask equipped with a thermometer, an ester trap, a cooling tube, and a dropping funnel, which was sealed with dry nitrogen, and dropped while stirring. 47.3 g (0.4 mole) of trimethylsilyl ethanol was added. The reaction was then carried out at 60 ° C for 8 hours under dry nitrogen aeration. By analyzing the transparent liquid refluxed into the ester trap by gas chromatography, it was confirmed that most of the isopropanol refluxed. The four-necked flask was then set to a vacuum condition, and the remaining alcohol contained in the system was removed at 60 ° C for one hour. A transparent liquid remained in the flask, and about 45 g of an organic titanium compound (2) was obtained (in the general formula (2), R ¹ = isopropyl, R ² = ethyl substituted with trimethylsilyl, x1 = 0, y1 = 4) (organic titanium compound) (yield; about 87.3%). The metal content of the obtained organic titanium compound (2) was 10.1% (theoretical value; 9.3%).

[Synthesis Example 3]
23 g (about 0.05 mol) of the organic titanium compound (1) obtained in Synthesis Example 1 was placed in a 100-ml four-necked flask sealed with dry nitrogen and equipped with a thermometer and a dropping funnel, and was dropped while stirring. 13.2 g (0.1 mol) of ethyl acetate. After the reaction was carried out at 60 ° C for 8 hours, the four-necked flask was set to a vacuum condition, and the remaining alcohol contained in the system was removed at 60 ° C for 3 hours. A brown transparent liquid remained in the flask, and about 21 g of an organic titanium compound (3) was obtained (in the general formula (3), R ² = a methyl group substituted with a trimethylsilyl group, x2 = 2, y2 = 2 organic titanium compound) (yield; about 81.7%). The metal content of the obtained organic titanium compound (3) was 9.5% (theoretical value; 9.3%).

[Synthesis Example 4]
27.8 g (about 0.05 mol) of the organic titanium compound (2) obtained in Synthesis Example 2 was placed in a 100-ml four-necked flask sealed with dry nitrogen and equipped with a thermometer, and dropped into a funnel, and dropped while stirring. 13.2 g (0.1 mol) of ethyl acetate was added. After the reaction was carried out at 60 ° C for 8 hours, the four-necked flask was set to a vacuum condition, and the remaining alcohol contained in the system was removed at 60 ° C for 3 hours. A yellow and transparent liquid remained in the flask, and about 23 g of an organic titanium compound (4) was obtained (in the general formula (3), R ² = an ethyl group substituted with a trimethylsilyl group, x2 = 2, y2 = 2 organic titanium compound) (yield; about 84.9%). The metal content of the obtained organic titanium compound (4) was 9.0% (theoretical value; 8.8%).

The following evaluations were performed using the organic titanium compounds obtained in the above Synthesis Examples 1 to 4 and tetraisopropyl titanate and diisopropoxybis (ethyl ethyl acetate) titanium for comparison. These results are shown in Table 1.
a. Hydrolytic evaluation;
The organic titanium compound was exposed to a 23 ° C / 50% RH environment, and the properties after 24 hours were visually confirmed.
b. Evaluation of low temperature traits;
The organic titanium compound was filled in a closed container and exposed to an environment of -0 ° C, and the properties after 24 hours were visually confirmed.

From the results in Table 1 above, it is clear that the organic titanium compound synthesized above is equivalent to the existing organic titanium compound used for comparison in view of the fact that it can be cured by a hydrolyzability evaluation test. The hydrolysis performance. In addition, in the evaluation of low-temperature properties, the existing titanium chelate, that is, diisopropoxybis (ethylacetate) titanium is a solid. In contrast, the synthesized titanium chelate is also described above. The organic titanium compounds (1) to (4) obtained in the synthesis examples are liquid at room temperature (23 ° C ± 10 ° C). From the results, it was found that even in a low-temperature environment such as winter, the property does not change like diisopropoxybis (ethylacetate) titanium, so it is easy to handle.

[Example 1]
Add 5.0 parts of methyltrimethoxysilane and 3.0 parts of organotitanium compound (1) to 100 parts of linear dimethylpolysiloxane sealed with trimethoxysilyl at both ends of the molecular chain with a viscosity of 1,000mPa‧s And mixed under a moisture barrier until it becomes homogeneous to prepare the composition (1).

[Example 2]
Add 5.0 parts of methyltrimethoxysilane and 3.0 parts of organotitanium compound (2) to 100 parts of linear dimethylpolysiloxane blocked with trimethoxysilyl groups at both ends of the molecular chain with a viscosity of 1,000 mPa‧s And mixed under a moisture barrier until it becomes homogeneous, thereby preparing the composition (2).

[Example 3]
Add 5.0 parts of methyltrimethoxysilane and 3.0 parts of organotitanium compound (3) to 100 parts of linear dimethylpolysiloxane blocked at both ends of the molecular chain with a viscosity of 1,000 mPa‧s by a trimethoxysilyl group. And mixed under a moisture barrier until it becomes homogeneous, thereby preparing the composition (3).

[Example 4]
Add 5.0 parts of methyltrimethoxysilane and 3.0 parts of organotitanium compound (4) to 100 parts of linear dimethylpolysiloxane blocked with trimethoxysilyl groups at both ends of the molecular chain with a viscosity of 1,000 mPa‧s And mixed under a moisture barrier until it becomes homogeneous to prepare the composition (4).

[Comparative Example 1]
In Example 1, except that 3.0 parts of tetraisopropyl titanate was used in place of the organic titanium compound (1), a composition (5) was prepared in the same manner as the rest.

[Comparative Example 2]
In Example 1, except that 3.0 parts of tetrabutyl titanate was used in place of the organic titanium compound (1), the composition (6) was prepared in the same manner as in the other examples.

[Comparative Example 3]
In Example 1, 3.0 parts of tetrakis (tributyl) titanate was used instead of the organic titanium compound (1), and the composition (7) was prepared in the same manner.

[Comparative Example 4]
In Example 3, except that 3.0 parts of diisopropoxy bis (ethyl ethyl acetate) titanium was used in place of the organic titanium compound (3), the composition (8) was prepared in the same manner.

[Comparative Example 5]
In Example 3, except that 3.0 parts of dioctyloxybis (octanediol ester) titanium was used in place of the organic titanium compound (3), a composition (9) was prepared in the same manner as the rest.

[Comparative Example 6]
In Example 3, except that 3.0 parts of titanium diisopropoxy bis (ethyl acetoacetate) was used in place of the organic titanium compound (3), the composition (10) was prepared in the same manner as in the other examples.

The compositions obtained in the above examples and comparative examples were measured for the non-viscosity time, the hardness, and the transparency of the hardened materials by the methods described below and evaluated.

[experiment method]
The compositions prepared in the above examples and comparative examples measure the non-sticking time (touch drying time) in accordance with the method prescribed by JIS A5758.
In addition, the composition prepared in the above examples and comparative examples was put into a mold frame having a thickness of about 2 mm, and was cured at 23 ° C. and 50% RH for 7 days to obtain a 2 mm thick rubber sheet. The obtained rubber sheet was used to measure rubber hardness in accordance with JIS K6249. The hardness is measured using a rubber hardness meter A hardness tester of JIS K6249.
In addition, the transparency of the obtained rubber sheet was measured at 500 nm (A) and 800 nm (B) using a spectrophotometer U-3310 manufactured by Hitachi Hi-Techno Science, and the difference was within ± 5%. Those within the range were judged as "Passed".
The results of the following Examples 1 to 4 and Comparative Examples 1 to 6 are shown in Table 2.

[Evaluation]
The compositions of Examples 1 to 4 are those satisfying the requirements of the present invention. They have good hardenability, and the hardness of the hardened product of the composition is also high, and it is known that they are good elastomers. In addition, since the difference in light transmittance from 800 nm to 500 nm is also about 1 to 3%, it is known that the transparency is extremely high.
In contrast, the compositions of Comparative Examples 1 to 6 are catalysts using an existing organic titanium compound as a moisture-curable composition. The composition of Comparative Examples 1 to 4 is an example using an existing titanium alkoxide as a catalyst. However, although the non-viscosity time showing the hardening property is fast, the hydrolyzability of the titanium alkoxide is high, and the compound after hydrolysis is changed to Those who are not easily soluble in organic polysiloxane, so the difference in light transmittance between 800nm and 500nm becomes 5% or more, which results in poor transparency. In addition, the composition of Comparative Examples 5 and 6 is an example using an existing titanium chelate as a catalyst, but even after using these, the hydrolyzed compound also changed to a substance that is not easily soluble in organic polysiloxane, so 800 nm The difference in light transmittance to 500 nm becomes 5% or more, which is a result of poor transparency. From the above results, the effectiveness of the present invention can be confirmed.

[Industrial applicability]

The organic titanium compound of the present invention has the same hardenability as the conventional organic titanium compound, and the moisture-curable composition prepared with the organic titanium compound has good hardenability. When the moisture-curable composition containing polysiloxane as a main component is cured, it becomes an elastic solid material with high transparency. Therefore, there are high expectations for the application of electric and electronic parts, etc., and it is also expected to be used as a building sealant or an automotive oil seal.

Claims (10)

An organic titanium compound containing at least one hydrolyzable group represented by the following structural formula (1) in a molecule, (In the formula, E is an alkylene group having 1 to 4 carbon atoms, and R is an alkyl group having 1 to 4 carbon atoms.) The organic titanium compound according to claim 1, which is represented by any one of the following general formulae (2), (3), (4), and (5), [Wherein R ¹ is a monovalent hydrocarbon group having 1 to 6 carbon atoms; R ² is represented by the following general formula (6) (In the formula, E is an alkylene group having 1 to 4 carbon atoms, and R is an alkyl group having 1 to 4 carbon atoms.) A trialkylsilyl substituted alkyl group as shown; x1 is an average value of 0 to 3 , Y1 is an average of 1 to 4, and x1 + y1 is 4; x2 is an average of 1 to 3, y2 is an average of 1 to 3, and x2 + y2 is 4]. The organic titanium compound according to claim 1 or 2 is used as a curing catalyst for a moisture curing composition. A moisture-curable composition containing an organic titanium compound as claimed in claim 3 and imparting an elastomer by moisture curing. The moisture-curable composition according to claim 4, which comprises: a polymer material having two or more hydroxyl groups or alkoxy groups bonded to silicon in a molecule, and an organic oxysilane curing agent. For example, the moisture-curable composition of claim 5, wherein the polymer material having two or more silicon-bonded hydroxyl groups or alkoxy groups in the molecule is a polymer material having two or more silicon-bonded hydroxyl groups or Organic polysiloxanes of alkoxy group. The moisture-curable composition according to claim 5 or 6, further comprising a filler. An electric and electronic part, which is a hardened product having the composition according to any one of claims 4 to 7 above. A sealant for construction, which is composed of a hardened product of the composition according to any one of claims 4 to 7. An automotive oil seal is formed of a hardened product of the composition according to any one of claims 4 to 7 above.