JPH11189652A - Organosilicon polymer and its producti0n - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an organosilicon polymer which has both excellent chemical properties equivalent to those of a high-mol.-wt. polysilane and an excellent solubility by forming an organosilicon polymer having a specified glass transition temp. SOLUTION: The objective organosilicon polymer has a main structure of the formula, a glass transition temp. of 20 deg.C or higher, and a wt. average mol.wt. of 2,500-4,000 and is prepd. by reacting trihydrosilane in the presence of 100-1,000 ppm metallocene catalyst in an inert gas atmosphere at from room temp. to 80 deg.C for at least 24 hr and subjecting the resultant polysilane to dehydration and condensation at 120 deg.C or higher for 2-8 hr. The metallocene catalyst is a zirconocene catalyst formed by reacting dichlorozirconocene with an alkyllithium in the reaction system and is used as a dehydration and condensation catalyst. In the formula, R is a 1-10C optionally substd., linear or branched alkyl group or a 6-14C optionally substd. arom. hydrocarbon group; and (n) and (m) are each an integer provided n+m>=20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a polysilane having excellent chemical properties and excellent solubility in various solvents.
And shows a solid shape at room temperature, easy to handle,
The present invention relates to a novel organosilicon polymer which can be effectively used as a precursor of a silicon carbide ceramic, a photoresist material, a photopolymerization initiator, various conductive materials, and the like, and a method for producing the same.

[0002]

2. Description of the Related Art
As a method for producing polysilane, a method utilizing the Wurtz reaction of diorganodichlorosilane with metallic sodium is generally used. However, this method has a problem in that the use of metallic sodium and poor pot yield during synthesis are problematic.

On the other hand, the method of producing polysilane using the dehydrocondensation method is high in both the yield and pot yield of polysilane, but has the disadvantage that the molecular weight of the produced polysilane is not so large. Was.

In this case, since the chemical properties such as the optical properties of the polysilane are the same regardless of the molecular weight of the polysilane having a polymerization degree of 20 or more, the polysilane obtained by the dehydrocondensation method is the same. In the production method, materialization by cross-linking using side-chain hydrogen groups has been studied in order to increase the molecular weight of polysilane.

Conventionally, in the study of the dehydrocondensation method, attention has been paid to obtaining a polymer having a high degree of polymerization. For this purpose, a reaction is carried out for a long time at a low temperature of 100 ° C. or less using a zirconocene catalyst. Is found to be necessary. It has been reported that a polysilane having a weight-average molecular weight of about 10,000 can be synthesized by such a long reaction. However, a polymer having a molecular weight of about 10,000 or less has a shape of syrup at room temperature. And there was a problem in handling.

The present invention has been made in view of the above circumstances, and an organosilicon-based polymer having excellent chemical properties as a polysilane and easy to handle at room temperature, and a polymer having high reproducibility and high yield. An object of the present invention is to provide a method for producing the organosilicon-based polymer which can be produced by the method described above.

[0007]

Means for Solving the Problems and Embodiments of the Invention The present inventors have made intensive studies to achieve the above object, and as a result, using trihydrosilane as a starting material, a metallocene catalyst, particularly a zirconocene dehydrocondensation catalyst. In the presence, in an inert gas atmosphere in the absence of a solvent or in the presence of a solvent, start the reaction at a low temperature of 80 ° C. or less, perform the reaction for 24 hours or more in this temperature range, and after gradually obtaining a certain degree of polymerization, gradually A novel organosilicon-based polymer whose main structure is represented by the following general formula (1) with good reproducibility by dehydrocondensation by raising the reaction temperature and finally performing the reaction at a temperature of 120 ° C. or higher This polymer has a degree of polymerization of 20 or more capable of showing the chemical properties of polysilane, and as a polysilane, an excellent chemical equivalent to high molecular weight polysilane. Above having properties excellent in solubility,
And has a glass transition point (Tg) of room temperature (20 ° C.) or higher, exhibits a solid shape at room temperature, is easy to handle, and the organosilicon-based polymer of the above formula (1) is a silicon carbide ceramic. Precursors, photoresist materials,
The present inventors have found that they can be effectively used as a photopolymerization initiator, a conductive material, a photoconductive material, a nonlinear optical material, and the like, and have accomplished the present invention.

That is, as described above, although a relatively high-molecular-weight polysilane is obtained in a low-temperature and long-time reaction using a zirconocene catalyst, it becomes syrup-like, but is further heated to a high temperature of 120 ° C. or more. Although only a low molecular weight polymer is produced when the reaction is carried out, the obtained polymer has a high glass transition point (Tg) and shows a solid state at room temperature.

Accordingly, the present invention provides an organosilicon-based polymer having a main structure represented by the following general formula (1) and having a glass transition point of 20 ° C. or higher.

[0010]

Embedded image (In the formula, R represents a group selected from a substituted and unsubstituted linear and branched alkyl group having 1 to 10 carbon atoms and a substituted and unsubstituted aromatic hydrocarbon group having 6 to 14 carbon atoms. Further, n and m are integers that satisfy n + m ≧ 20.)

In the present invention, a reaction is carried out at a temperature of 80 ° C. or less in an inert atmosphere in the presence of a metallocene catalyst using trihydrosilane as a starting material, and then the reaction temperature is raised to 120 ° C. or more. A method for producing the organosilicon-based polymer, wherein the reaction is further performed at a temperature.

In this case, the manufacturing method of the present invention described above
It utilizes the fact that the selectivity of the dehydrocondensation reaction of trihydrosilane varies depending on the reaction temperature. First, in the low-temperature reaction of 80 ° C. or lower at the beginning of the reaction, the chain extension reaction of the hydrosilane proceeds selectively, and The side reactions other than the long elongation reaction are suppressed.
In the reaction under the high temperature conditions described above, it is considered that the rate of the three-dimensional crosslinking reaction gradually increases with the accompanying degradation, and the three-dimensional crosslinking reaction proceeds relatively slowly. An organosilicon-based polymer having excellent chemical properties, excellent solubility, and showing a solid shape at room temperature can be produced with good reproducibility.

Now, the present invention will be described in further detail. The main structure of the organosilicon-based polymer of the present invention is represented by the following general formula (1).

[0014]

Embedded image (In the formula, R represents a group selected from a substituted and unsubstituted linear and branched alkyl group having 1 to 10 carbon atoms and a substituted and unsubstituted aromatic hydrocarbon group having 6 to 14 carbon atoms. Further, n and m are integers that satisfy n + m ≧ 20.)

Here, the unsubstituted alkyl group includes methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl and the like. Octyl group, decyl group and the like, and unsubstituted aromatic hydrocarbon groups include phenyl group, naphthyl group, tolyl group, benzyl group, phenylethyl group and the like. Also,
Examples of the substituted alkyl group and aromatic hydrocarbon group include the above unsubstituted alkyl group and aromatic hydrocarbon group in which some or all of the hydrogen atoms are halogen atoms such as fluorine, tertiary amino groups, carboxyl groups, ) Groups substituted with an acryl group, a mercapto group, a polyether group, a higher fatty acid ester group and the like can be mentioned.

Although n and m are integers satisfying n + m ≧ 20, it is preferable that n + m is larger. Although the upper limit is not particularly limited, it is not preferable that the ratio of m is large and m + n is too large, since the solubility in a general organic solvent is deteriorated.

The weight average molecular weight of the polymer of the formula (1) is usually 2,000 or more, especially 2,500 to
It is preferably 4,000.

The organosilicon polymer of the above formula (1) has a Tg of room temperature (20 ° C.) or more, preferably 40 to 7 ° C.
The temperature must be 0 ° C., and if Tg is lower than room temperature, handling becomes difficult.

The organosilicon polymer of the above formula (1) of the present invention is obtained by reacting trihydrosilane as a starting material at a temperature of 80 ° C. or less in an inert atmosphere in the presence of a metallocene catalyst, And further react at a temperature of 120 ° C. or higher.

Here, as the trihydrosilane, RS
The one represented by iH ₃ (R has the same meaning as described above) is used.

As the metallocene catalyst, a zirconocene catalyst is usually used. As the zirconocene dehydrogenation / condensation catalyst, a commonly used zirconocene dehydrogenation catalyst can be used.Specifically, dichlorozirconocene and alkyllithium are reacted in the system to prepare a dehydrogenation / condensation catalyst, and the polymerization reaction is immediately carried out. It is preferred to do so. The amount of the catalyst used may be a catalyst amount, for example, 100 to
A range of 1,000 ppm is preferred.

As the inert gas, argon, nitrogen or the like is used.

The above dehydrocondensation reaction is generally carried out without a solvent. When a solvent is used, it is desirable to use a solvent such as octane or decane in the same amount as that of trihydrosilane.

In the present invention, the above-mentioned trihydrosilane raw material and the dehydrocondensation catalyst are first used at room temperature (20
C.) to 80 ° C. or lower, preferably 50 to 70 ° C., and the dehydrocondensation reaction is started, and the reaction is carried out at low temperature for 24 hours or longer, preferably 48 to 72 hours. In the reaction under this low temperature condition, the weight average molecular weight becomes 3,000 to 50,000 while the hydrosilane as the raw material gradually generates hydrogen.
Although a polysilane having a molecular weight distribution close to a normal distribution can be obtained at 00, this polysilane usually shows a syrupy appearance at room temperature.

When the weight average molecular weight becomes 3,000 or more, the reaction temperature is raised to 120 ° C. or more, preferably
The temperature is raised to 180 ° C, more preferably 120 to 150 ° C, and the dehydrocondensation reaction is performed for 1 to 12 hours, preferably 2 to 8 hours. If the temperature at the final stage of the reaction is too high, the progress of the degradation is extremely fast, and precise adjustment of the reaction time is required, which is troublesome. If the temperature is lower than 120 ° C., the progress of the reaction contributing to the rise of Tg is slow, and It is not practical because it takes a long time. When the reaction time is less than 1 hour, a sufficient reaction is not performed, and when the reaction time is longer than 12 hours, it is not practical. Therefore, it is practical to carry out the reaction at a slightly higher temperature in a short time.

[0026]

The novel organosilicon polymer of the present invention represented by the above formula (1) and having a silicon chain length of 20 or more and a glass transition point of room temperature or more has a high molecular weight polysilane and a high molecular weight polysilane. It is a polysilane that has the same solubility but is excellent in solubility, and is easy to handle because it is in a solid form at room temperature, is not susceptible to chemical deterioration such as oxidation, and is easy to use for application to strong polysilane films due to crosslinking reactions and the like. It can be effectively used as a precursor of silicon carbide ceramics, a photoresist material, a photopolymerization initiator, a conductive material, a photoconductive material, a nonlinear optical material, and the like. Further, according to the method for producing an organosilicon polymer of the present invention, the organosilicon polymer of the above formula (1) can be produced with good reproducibility by a dehydrocondensation method.

[0027]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples.

Example 1 In an argon atmosphere, 30 mg of dichlorozirconocene, 20 ml of anhydrous ether and 50 μl of a methyllithium 1.6N ether solution were charged and reacted at room temperature for 1 hour to prepare a dehydrocondensation catalyst. Next, the solvent was distilled off under reduced pressure, and the obtained catalyst was evaporated to dryness. Then, 50 g of phenylsilane was charged and reacted at 80 ° C. for 24 hours. Mw) A polysilane having a molecular weight distribution of about 3,300 and almost a normal distribution was obtained. At this time, Tg was 16.3 ° C., and the syrup-like appearance was shown. Thereafter, the reaction temperature was increased to 130 ° C., and the dehydrogenation reaction was further performed for 3 hours. As a result, although a slight reduction in molecular weight was observed (Mw = 2,600), a glassy polymer (Tg32.3) was obtained at room temperature. ° C) was obtained almost quantitatively. The structure deduced from the ¹ H NMR analysis result of the obtained polymer was represented by the following formula. Table 1 shows the analysis results.

[0029]

Embedded image

After the reaction at 130 ° C. for 3 hours, the reaction temperature was further raised to 200 ° C., and the reaction was carried out for 5 hours.
w was reduced to 910, while Tg was 78.2 ° C., which was equivalent to performing the dehydrogenation reaction at 200 ° C.

Therefore, it is best to carry out the reaction at a reaction temperature of 80 ° C. or lower for 24 hours or more, and then to carry out the reaction at about 120 to 150 ° C. for several hours. A method utilizing the fact that side reactions other than the above are suppressed and that the degradation reaction is not so fast under the condition of 150 ° C. or lower can provide a three-dimensional crosslinked polysilane having a desired degree of polymerization and Tg with good reproducibility. .

[Examples 2 to 5] 80 ° C. according to Example 1
, And then a high-temperature reaction was performed at the temperature and time shown in Table 1. As a result, a polymer having a glass transition point at room temperature or higher was obtained in each case.

[0033]

[Table 1]

Claims (2)

[Claims] The main structure is represented by the following general formula (1):
An organosilicon polymer having a glass transition point of 0 ° C. or higher. Embedded image (In the formula, R represents a group selected from a substituted and unsubstituted linear and branched alkyl group having 1 to 10 carbon atoms and a substituted and unsubstituted aromatic hydrocarbon group having 6 to 14 carbon atoms. Further, n and m are integers that satisfy n + m ≧ 20.) 2. A reaction is carried out at a temperature of 80 ° C. or less in an inert atmosphere in the presence of a metallocene catalyst using trihydrosilane as a starting material, and then the reaction temperature is raised, and the reaction is further carried out at a temperature of 120 ° C. or more. 2. The method for producing an organosilicon-based polymer according to claim 1, wherein