JPH0578490A - Aluminosiloxane polymer and method for producing the same - Google Patents

Abstract

(57) [Summary] [Purpose] High stability at room temperature, easy to use, low content of impurities, and easy to become completely inorganic by heating,
Provided are an aluminosiloxane polymer and a method for producing the same. A solution containing, as a silicon-containing starting material, a partially decomposed product of a tetraalkoxysilane having an alkoxy group having 1 to 4 carbon atoms, and an aluminum-containing starting material, acetylacetonate aluminum diisopropoxide and And / or a solution containing ethyl acetoacetate aluminum diisopropoxide at a ratio such that the ratio of the number of Si / Al atoms is 0.5 or more and 20.0 or less,
A method for producing an aluminosiloxane polymer, which comprises reacting.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing an aluminosiloxane polymer. The aluminosiloxane polymer obtained by the present invention can be an inorganic oxide cured product composed of an aluminum atom, a silicon atom, and an oxygen atom by further subjecting it to a hydrolysis and a thermal decomposition reaction. First, an inorganic coating agent,
It is used as a raw material for inorganic adhesives and inorganic binders.

[0002]

_2. Description of the Related Art As a method for producing a hardened Al ₂ O ₃ --SiO ₂ type inorganic oxide using an aluminosiloxane polymer as a precursor, silicic acid and ethyl acetoacetate extracted in tetrahydrofuran (hereinafter THF) are used. A method is known in which an aluminosiloxane polymer obtained by reaction with toaluminium diisopropoxide is used as a precursor. However, the above method is not suitable for industrial production because it undergoes an extraction process of silicic acid into THF. That is, in order to extract silicic acid into THF to prepare a THF solution of silicic acid, processes such as neutralization of sodium metasilicate, extraction with THF, salting out, liquid separation, drying, and filtration must be performed. In addition, in this process, it is inevitable that chlorine ions and sodium ions, which deteriorate the performance of the aluminosiloxane polymer, are unavoidable, which makes industrialization of the production of the Al ₂ O ₃ —SiO ₂ type inorganic oxide cured product difficult. .. Further, in this conventional method, if the ratio of the number of Si and Al atoms in the raw material solution component (hereinafter referred to as S / A ratio) is 4 or more, the self-condensation reaction easily proceeds and gelation occurs within 30 minutes. The phenomenon may even occur. As another method for producing an Al ₂ O ₃ —SiO ₂ type inorganic oxide cured product using an aluminosiloxane polymer as a precursor, as disclosed in JP-B-51-13768, an organic aluminum compound and water are used. As a raw material, polyaluminoxane having a main chain of —Al—O— produced by a condensation polymerization reaction with
A viscous liquid to which a silicate ester was added as an iO ₂ source was used as a spinning solution, and a precursor fiber was formed by dry spinning, and the obtained precursor fiber was heated in air to 1,000 ° C. or higher to leave an organic residue. A method of producing a continuous fiber containing a SiO ₂ component in an amount of 0 to 60% by weight is known. However, this method has a problem that when the content of SiO ₂ is tried to be increased, the viscosity of the mixed solution is lowered and spinning becomes difficult.

[0003]

Aluminosilicate siloxane polymer solution [invention is a problem to be solved was prepared in a conventional manner of the inorganic fiber for pot life is too short, paint, adhesive, difficult to use as industrial raw materials to make, such as a binding agent, SiO ₂ There is a problem in that it is not possible to produce inorganic fibers having a high content of. Therefore, the object of the present invention is to have high stability at room temperature, easy to use, and
It is an object of the present invention to provide a solvent-soluble aluminosiloxane polymer capable of varying the content ratio of _{2 in} a wide range and a method for producing the same.

[0004]

A solution containing a partial hydrolyzate of a tetraalkoxysilane having an alkoxy group having 1 to 4 carbon atoms (hereinafter referred to as TAOS) as a silicon-containing starting material, and an aluminum-containing starting material. A solution containing acetylacetonate aluminum diisopropoxide and / or ethyl acetoacetate aluminum diisopropoxide as a substance, wherein the S / A ratio in the above two starting substances is 0.5 or more and 20.0 or more. The present inventors have succeeded in producing an aluminosiloxane polymer that achieves the above-mentioned object by blending and reacting in the following proportions.

The present invention will be described in detail below. In the method for producing an aluminosiloxane polymer of the present invention, a partial hydrolyzate of TAOS having an alkoxy group having 1 to 4 carbon atoms is used as a silicon-containing starting material, and acetylacetonate aluminum diisolate is used as an aluminum-containing starting material. Propoxide and / or ethyl acetoacetate aluminum diisopropoxide are used. The former partial hydrolyzate of TAOS is represented by the general formula (1) Si (OR) ₄ (1) (wherein, R is an alkyl group having 1 to 4 carbon atoms).
Is partially hydrolyzed under a condition that the water / TAOS molar ratio is 1.5 or more and less than 4.0 in a mixed solvent of water and an organic solvent such as methanol or ethanol. It is preferably obtained by decomposition. The temperature of the reaction liquid during this hydrolysis is -50 to + 50 ° C, especially -20 to +
It is preferably set in the range of 25 ° C. Further, when the hydrochloric acid, acetic acid or nitric acid is added in an amount of about 0.01 to 0.1 times the molar amount of TAOS during the hydrolysis, the hydrolysis is effectively performed.

The partial hydrolyzate of TAOS is represented by the general formula (2) Si (OH) _m (OR) _4-m (2) (wherein R is the same as the definition in the general formula (1),
m is an integer of 1, 2 or 3. ). In order to smoothly carry out the reaction with an aluminum-containing starting material, which will be described in detail later, and to efficiently produce an aluminosiloxane polymer having desired properties (composition, molecular weight, solvent solubility, self-condensation stability, spinnability), , The reaction temperature is 0 to +
It is particularly preferable that the water / TAOS molar ratio is set to about 2.5 to 3.5 at 20 ° C. to prepare a solution containing a large amount of the partial hydrolyzate of TAOS represented by the general formula (3). General formula (3)

[0007]

[Chemical 1] (In the formula, R is the same as the definition in the general formula (1),
n is an integer of 1 or 2 or more. )

A partial hydrolyzate of TAOS (n
= 1) or a low polymer thereof (n ≧ 2) is preferably reacted with acetylacetonate aluminum diisopropoxide or ethyl acetoacetate aluminum diisopropoxide described below. That is, in the compound represented by the general formula (3), each of the two hydroxyl groups reacts with the two reaction sites of the aluminum-containing starting material described below to form a chain-like substance, and the remaining 1
An aluminosiloxane polymer having desired physical properties (solvent solubility, self-condensation stability, stability in solution, spinnability) can be obtained by forming hydrogen bonds with individual hydroxyl groups, for example, with other chain-like substances. Be done.

In the production of the aluminosiloxane polymer of the present invention, the partial hydrolyzate of TAOS is used as the silicon-containing starting material, and the aluminum-containing starting material is acetylacetonate aluminum diisopropoxide or ethyl acetoacetate. Limited to toaluminium diisopropoxide. These aluminum-containing starting materials may be prepared in advance, but are obtained by reacting aluminum triisopropoxide with equimolar amounts of acetylacetone or ethyl acetoacetate in a solvent such as 2-propanol. It may be used as it is for the reaction with the silicon-containing starting material without isolation. In the reaction between the silicon-containing starting material and the aluminum-containing starting material, it is necessary to mix both the starting materials so that the S / A ratio is 0.5 or more and 20.0 or less. The reason for this is that if the S / A ratio is less than 0.5, the polycondensation reaction will not proceed sufficiently, making it difficult to prepare a highly viscous solution that can be spun, and if the S / A ratio exceeds 20.0, the solvent It is difficult to obtain an aluminosiloxane polymer having good stability. On the other hand, the S / A ratio is 0.5 or more and 20.
When it is in the range of 0 or less, preferably in the range of 1.0 to 4.0, an aluminosiloxane polymer exhibiting spinnability is obtained, and finally, an inorganic oxide cured product such as inorganic fiber is obtained. This is because it has excellent strength and heat resistance. In the above-mentioned conventional method, when the S / A ratio is 4 or more, gelation occurs, but in the method of the present invention, even if the S / A ratio is 4 or more and 20.0 or less, desired alumino There is an advantage that a siloxane polymer can be obtained.
The reaction is preferably carried out at room temperature to the reflux temperature of the solvent for 0.5 to 3 hours, particularly about 1 hour.

According to the method of the present invention, an acetylacetonate or ethylacetoacetate group is coordinated with an aluminum atom as a side chain group, and the main chain is composed of an aluminosiloxane bond (Al-O-Si). A polymer is formed. NMR of acetylacetonate aluminosiloxane polymer
In the spectrum, the peak based on the acetylacetate group is about 2.0 ppm and about 5.2 ppm, and the peak is about 3.5 ppm.
Peaks based on the vinyl group were observed, while the NMR spectra of the ethyl acetoacetate aluminosiloxane polymer showed ethylacetoacetate at about 1.2 ppm, about 1.8 ppm, about 4.4 ppm and about 4.7 ppm. A peak based on a silanol group is observed at about 3.5 ppm peak based on a phenol group. The obtained aluminosiloxane polymer has a highly viscous spinnability by concentrating the solution of the reaction mixture, and can be used as a spinning solution for precursor fibers of Al ₂ O ₃ —SiO ₂ inorganic fibers. Precursor fibers produced by a known dry spinning method using this spinning solution as a raw material can easily be burned at a temperature of 600 ° C. or higher to easily produce Al ₂ O ₃ —Si.
It may be an O ₂ inorganic fiber. Further, by performing steam treatment before firing, elimination and removal of organic functional groups in the precursor fiber can be promoted, and high-purity and high-strength Al ₂ O ₃ —SiO ₂ -based inorganic fiber can be produced in a short time. can do.

Alternatively, the highly viscous solution may be dissolved in a small amount of acetone, and then a large amount of hexane may be added to separate and collect a precipitate to obtain a powdery substance. This powdery substance is soluble in an organic solvent such as methanol, ethanol, acetone, chloroform and the like, and the dissolved substance shows spinnability, which is also a precursor of Al ₂ O ₃ -SiO ₂ inorganic fiber. It becomes a fiber and is convenient for storage and transportation. The aluminosiloxane polymer solution obtained by the method of the present invention has little change with time in viscosity when concentrated or dissolved in an organic solvent as a powder, and has a long working life and long-term storage, and is industrially usable. Suitable for use. Further, since the aluminosiloxane polymer obtained by the method of the present invention is soluble in various organic solvents, when it is used as a coating agent, an adhesive, a binder, etc., it dries quickly and is coated or bonded. There is also an advantage that the bonding time is short.

[0012]

The present invention will be further described based on the following examples. Example 1 Tetraethoxysilane 10.
1.0 g of water was added to a solution prepared by mixing 4 g of methanol with 50 ml of methanol.
A partial hydrolysis reaction was carried out by adding a solution prepared by mixing 4 g and 0.95 g of 6N hydrochloric acid and 50 ml of methanol at 0 ° C. After the heat generation was completed, a mixed solution of 6.11 g of acetylacetonate aluminum diisopropoxide (hereinafter referred to as PAP) and 20 ml of ethyl alcohol was added. The S / A ratio was 4/1 based on the amounts of tetraethoxysilane and acetylacetonate aluminum diisopropoxide used. A reaction mixture was obtained by reacting for 1 hour under reflux of the solvent. A viscous concentrate is obtained in the process of distilling off the solvent from this reaction mixture, and when it is brought into contact with a glass rod and then pulled out, it shows spinnability, and Al ₂ O ₃ --SiO _2
It was clarified that it can be a precursor of ₂ type inorganic fibers.

Separately, 1 g of the above concentrated solution was taken, dissolved in 10 ml of acetone, and then 50 ml of hexane was added to cause precipitation. By recovering this precipitate and drying it,
8 g of powder was obtained. This powder is methanol, ethanol
Soluble in acetone, acetone, chloroflum, etc., but insoluble in benzene, hexane, etc. A solution dissolved in a soluble solvent such as methanol also showed spinnability. Further, it has been clarified that the solution dissolved in the solvent has little change in viscosity with time and has a long pot life, and thus can be preferably used as a coating agent, an adhesive or a binder. NMR of the above powder
As a result, peaks based on acetylacetonate groups were observed at 2.0 ppm and 5.2 ppm, and peaks based on silanol groups were observed at 3.5 ppm. Also I of this powder
It was measured R spectrum, silanolate to 3400 cm ^-1 - group, acetylacetonate in 1580 and 1520 cm ^-1 - DOO groups, Si-O-to 1100～1000Cm ^-1
Absorption based on Si bond and Si—O—Al bond was observed at 1030 cm ⁻¹ .

Examples 2 and 3 Using the same raw materials as used in Example 1, H ₂ O /
A reaction mixture was obtained in the same manner as in Example 1 except that TEOS and the molar ratio of TEOS / PAP were changed as shown in Table 1 to perform the partial hydrolysis reaction and the polymerization reaction. The solvent was distilled off from these reaction mixtures, and the fiber length was shown as a measure of the spinnability of the resulting solutions. It can be seen from Table 1 that the aluminosiloxane polymers of Examples 1, 2 and 3 obtained by the method of the present invention have spinnability and thus can be precursors of Al ₂ O ₃ —SiO ₂ based inorganic fibers. Regarding the stability, the spinnable high-viscosity solution was sealed in a glass container and allowed to stand at room temperature for 6 months, and as a result of examining changes in appearance and spinnability, there was no change in appearance and there was little change in viscosity with time. Nozzle diameter 0.1m
m, discharge pressure 10 kg / cm ² , and winding speed 100 m / min.

[0015]

[Table 1] PAP: acetylacetonate - DOO aluminum diisopropoxide _{(Al (C 5 H 7 O} 2) (O i C 3 H 7) 2)

Comparative Example 1 1.5 mol / l in 250 ml of 4.0 mol / l hydrochloric acid
250 ml of the sodium metasilicate solution of was added dropwise with stirring at 10.degree. After the dropwise addition was completed, the mixture was stirred for 30 minutes and then 500 ml of tetrahydrofuran (THF) was added dropwise over 2 hours. To this solution, add 150 g of NaCl to 40
After stirring for a minute, the mixture was left for 30 minutes. Anhydrous sodium sulfate was added to the separated organic matter solution for dehydration, and the mixture was further cooled to -70 ° C, and water and ice were separated by filtration to obtain 370 ml of a 0.85 mol / l silicic acid-THF solution. 58.8 ml of this solution (S
3.05 g of PAP was added to the iO ₂ component (0.05 ml) so that the S / A ratio was 4.0, and the mixture was refluxed in 50 ml of methanol to obtain a reaction mixture. This solution was concentrated to a high viscosity so that it could be spun and left to stand at room temperature for 30 minutes, whereupon it gelled.

Comparative Example 2 1 mol of polyisopropoxyaluminoxane was dissolved in 600 ml of ethyl ether and hydrolyzed with 1 mol of water.
This polyaluminoxane was dissolved in benzene, and further 94.5 g of polydimethylsiloxane was dissolved therein. The concentrated viscous liquid was used as a spinning solution, and it was attempted to produce a precursor fiber by a dry spinning at a spinning speed of 100 m / min as in the example, but the fiber was easily cut and could not be wound as a long fiber. It was

[Effects of the Invention] As described above, according to the present invention, (a) it is difficult to control the reaction of the conventional aluminosiloxane polymer by the reaction between the silicon-containing starting material and the aluminum-containing starting material, and the random three-dimensional network structure is obtained. However, in the present invention, a partial hydrolyzate of TAOS, which is a silicon-containing starting material, and acetylacetonate aluminum diisopropoxide and / or ethyl acetoacetate aluminum diisopropoxy, which is an aluminum-containing starting material, are used in the present invention. The reaction is controlled by a simple operation of mixing the solvent in a solvent and stirring or heating under reflux to obtain an aluminosiloxane polymer which is difficult to gel. (B) In the co-hydrolysis of TAOS and aluminum triisopropoxide, a single condensation occurs due to the difference in the hydrolysis rate of each alkoxide, and a block polymer tends to be formed, which tends to result in a heterogeneous product. TAOS
Is partially hydrolyzed and then dealcoholized with acetylacetonate aluminum diisopropoxide or ethyl acetoacetate aluminum diisopropoxide to obtain an aluminosiloxane polymer, which is relatively copolymerizable. A homogenous block random polymer of aluminosiloxane is obtained.

(C) The aluminosiloxane polymer obtained by the present invention has a ligand bound to the aluminum atom of the aluminosiloxane bond in the main chain and an alkoxy group bound to the silicon atom as a side chain. Conventional T
Compared with an aluminosiloxane polymer obtained by co-hydrolysis of AOS and aluminum triisopropoxide or an aluminosiloxane polymer obtained by using silicic acid, it has high spinnability but high stability against self-condensation.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroaki Shono 2-532 Numanoue, Fushijima, Fukushima City, Fukushima Prefecture

Claims (3)

[Claims] 1. A solution containing a partial decomposition product of a tetraalkoxysilane having an alkoxy group having 1 to 4 carbon atoms as a silicon-containing starting material, and acetylacetonate aluminum diisopropoxy as an aluminum-containing starting material. And / or a solution containing ethyl acetoacetate aluminum diisopropoxide, wherein the ratio of the numbers of Si and Al atoms in the above two starting materials is 0.5 or more.
A method for producing an aluminosiloxane polymer, characterized in that the silicon-containing starting material and the aluminum-containing starting material are reacted in such a proportion that they are blended in a proportion such that they are 0 or less. 2. The partial hydrolyzate of tetraalkoxysilane as a silicon-containing starting material is a tetraalkoxysilane having an alkoxy group having 1 to 4 carbon atoms and a water / tetraalkoxysilane molar ratio of 1.5. The method for producing an aluminosiloxane polymer according to claim 1, which is obtained by partially hydrolyzing at a temperature of −50 to + 50 ° C. under a condition of being less than 4.0. 3. An aluminosiloxane polymer obtained by the method according to claim 1 or 2.