JP2022161583A - Reinforcing fiber-containing ceramic composition, fiber-reinforced ceramic matrix composite, and method for producing fiber-reinforced ceramic matrix composite - Google Patents

Abstract

To provide a reinforcing fiber-containing ceramic composition that can stably exist in a uniform state, a fiber-reinforced ceramic matrix composite using the same, and a method for producing the same.SOLUTION: A reinforcing fiber-containing ceramic composition, which is one aspect of the present invention, contains reinforcing fibers and a ceramic precursor polymer. The ceramic precursor polymer contains polymetalloxane. The polymetalloxane has a repeating structure of a metal atom selected from the group consisting of Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Zr, Nb, Mo, In, Sn, Sb, Hf, Ta, W, and Bi and an oxygen atom, and has a hydroxyl group directly connected to the metal atom as part of the repeating structure.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a reinforcing fiber-containing ceramic composition, a fiber-reinforced ceramic matrix composite, and a method for producing a fiber-reinforced ceramic matrix composite.

Conventionally, the development of ceramic matrix composites using ceramics as a parent phase (ceramic matrix) has progressed. In general, ceramics are materials that are excellent in heat resistance, abrasion resistance, strength, etc., but are hard and brittle. For this reason, in the production of ceramic matrix composites, reinforcing fibers are added to the ceramic matrix to enhance the toughness of the ceramic matrix.

A ceramic matrix composite containing a ceramic matrix reinforced as described above (hereinafter referred to as a fiber-reinforced ceramic matrix composite) is prepared by sintering ceramic particles impregnated in reinforcing fibers or firing a ceramic precursor oligomer. can be obtained by For example, in Patent Document 1, voids of ceramic fibers are impregnated with a slurry containing ceramic particles, and then the impregnated body of the ceramic fibers and the slurry is fired to sinter the ceramic particles in the slurry. A method is disclosed. Further, Patent Document 2 discloses a method of repeating a step of impregnating a reinforcing fiber with a ceramic precursor oligomer (for example, a boron-containing organosilazane polymer) and firing the reinforcing fiber.

JP 2012-12240 A JP-A-2005-239478

However, as exemplified in Patent Document 1, when ceramic particles are used, it is necessary to sinter the ceramic particles at a high temperature of, for example, 1600° C. or higher. be. Further, as exemplified in Patent Document 2, when a ceramic precursor oligomer is used, a ceramic matrix can be formed at a lower temperature than in the case of the ceramic particles, but the ceramic precursor oligomer has partial crystals during firing. change easily. For this reason, the uniformity of the ceramics matrix is insufficient, and minute cracks are likely to occur, which may reduce the strength of the ceramics matrix.

That is, in order to obtain a high-strength fiber-reinforced ceramic matrix composite, the ceramic matrix (hereinafter referred to as a reinforcing fiber-containing ceramic composition) used in the production of the fiber-reinforced ceramic matrix composite must be stable in a uniform state. Being present is important.

The present invention has been made in view of the above circumstances, and provides a reinforcing fiber-containing ceramic composition that can exist stably in a uniform state, a fiber-reinforced ceramic matrix composite using the same, and a method for producing the same. intended to provide

In order to solve the above-described problems and achieve the object, a reinforcing fiber-containing ceramic composition according to the present invention is a reinforcing fiber-containing ceramic composition containing reinforcing fibers and a ceramic precursor polymer, The ceramic precursor polymer contains polymetalloxane, and the polymetalloxane is Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Zr, It has a repeating structure of a metal atom selected from the group consisting of Nb, Mo, In, Sn, Sb, Hf, Ta, W and Bi and an oxygen atom, and a hydroxyl group directly attached to the metal atom is a hydroxyl group of the repeating structure. It is characterized by having a part.

Further, in the reinforcing fiber-containing ceramic composition according to the present invention, in the above invention, the metal atoms of the polymetalloxane are Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, It is characterized by being two or more metal atoms selected from Zn, Ga, Ge, Y, Zr, Nb, Mo, In, Sn, Sb, Hf, Ta, W and Bi.

Further, the reinforcing fiber-containing ceramic composition according to the present invention is characterized in that the reinforcing fiber has a fiber diameter of 0.1 μm or more and 200 μm or less.

Further, the reinforcing fiber-containing ceramic composition according to the present invention is characterized in that the reinforcing fiber is a non-woven fabric fiber.

Further, in the reinforcing fiber-containing ceramic composition according to the present invention, in the above invention, the polymetalloxane has a weight average molecular weight of 10,000 or more and 2,000,000 or less.

Further, the reinforcing fiber-containing ceramic composition according to the present invention is characterized in that, in the above invention, 10 mol % or more of the metal atoms contained in the polymetalloxane are Zr.

In the ceramic composition containing reinforcing fibers according to the present invention, the reinforcing fibers are selected from ceramic fibers, fibers made of polymetalloxane, and fibers made of a sintered body of polymetalloxane. It is characterized by being one or more types.

Further, in the reinforcing fiber-containing ceramic composition according to the present invention, in the above invention, the reinforcing fibers contain metal atoms, and 10 mol % or more of the metal atoms contained in the reinforcing fibers are Al. , characterized in that

Further, the reinforcing fiber-containing ceramic composition according to the present invention is characterized in that the reinforcing fiber is an alumina-based ceramic fiber in the above invention.

Further, a fiber-reinforced ceramic matrix composite according to the present invention is characterized by firing the reinforcing fiber-containing ceramic composition according to any one of the above inventions.

Further, a method for producing a fiber-reinforced ceramic matrix composite according to the present invention is a method for producing a fiber-reinforced ceramic matrix composite containing reinforcing fibers and a ceramic precursor polymer, wherein the ceramic precursor polymer is used for the reinforcement. and a firing step of firing the ceramic precursor polymer impregnated into the reinforcing fiber, wherein the ceramic precursor polymer contains polymetalloxane, and the polymetalloxane is , Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Zr, Nb, Mo, In, Sn, Sb, Hf, Ta, W and Bi It is characterized by having a repeating structure of a metal atom selected from the group and an oxygen atom, and having a hydroxyl group directly linked to the metal atom as part of the repeating structure.

ADVANTAGE OF THE INVENTION According to the present invention, it is possible to provide a reinforcing fiber-containing ceramic composition that can stably exist in a uniform state, a fiber-reinforced ceramic matrix composite using the same, and a method for producing the same. .

Preferred embodiments of the reinforcing fiber-containing ceramic composition, the fiber-reinforced ceramic matrix composite, and the method for producing the fiber-reinforced ceramic matrix composite according to the present invention are described below in detail. It should be noted that the present invention is not limited to the following embodiments, and can be implemented with various modifications according to the purpose and application.

(Reinforcing Fiber-Containing Ceramic Composition)
A reinforcing fiber-containing ceramic composition according to an embodiment of the present invention is a composition containing reinforcing fibers and a ceramic precursor polymer. In this reinforcing fiber-containing ceramic composition, the ceramic precursor polymer contains polymetalloxane. This polymetalloxane includes Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Zr, Nb, Mo, In, Sn, Sb, Hf, Ta, It has a repeating structure of a metal atom selected from the group consisting of W and Bi and an oxygen atom, and has a hydroxyl group directly linked to the metal atom as part of the repeating structure.

Hereinafter, for convenience of explanation, the reinforcing fiber-containing ceramic composition according to the embodiment of the present invention is referred to as a reinforcing fiber-containing ceramic composition (X), and the ceramic precursor contained in the reinforcing fiber-containing ceramic composition (X) The body polymer is called a ceramic precursor polymer (A), the polymetalloxane contained in the ceramic precursor polymer (A) is called a polymetalloxane (α), and the reinforcing fiber contained in the reinforcing fiber-containing ceramic composition (X) The fiber for reinforcement may be referred to as a reinforcing fiber (B).

(Ceramic precursor polymer (A))
The ceramic precursor polymer (A) is one component that constitutes the reinforcing fiber-containing ceramic composition (X). The ceramic precursor polymer (A) can be sintered in a state impregnated with the reinforcing fibers (B) to form a ceramic matrix whose physical properties such as toughness are reinforced by the reinforcing fibers (B). This ceramic matrix is a matrix that constitutes the fiber-reinforced ceramic matrix composite according to the embodiment of the present invention. Such a ceramic precursor polymer (A) contains polymetalloxane (α) shown below.

(Polymetalloxane (α))
Polymetalloxane is generally a polymer having a metal-oxygen-metal bond (hereinafter referred to as MO bond) as a main chain. The polymetalloxane (α) in the present invention has a repeating structure of MO bonds (that is, a repeating structure of metal atoms and oxygen atoms) in the main chain. Metal atoms constituting the repeating structure of the MO bond of such polymetalloxane (α) include Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Selected from the group consisting of Y, Zr, Nb, Mo, In, Sn, Sb, Hf, Ta, W and Bi. Furthermore, the polymetalloxane (α) has a hydroxyl group directly linked to the metal atom as part of the repeating structure of the MO bond. By having the above metal atoms and hydroxyl groups in the polymetalloxane (α), a highly heat-resistant ceramics precursor polymer (A) can be obtained, and crystallization of the ceramics precursor polymer (A) can be reduced. .

The metal atoms of the polymetalloxane (α) include Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Zr, Nb, Mo, In, Two or more metal atoms selected from the group consisting of Sn, Sb, Hf, Ta, W and Bi are preferred. When the polymetalloxane (α) has two or more of the above preferred metal atoms in the repeating structure of the MO bond, crystallization during firing of the ceramic precursor polymer (A) can be reduced, and the polymetalloxane (α) can be The solubility of the metalloxane (α) in organic solvents is improved, making it easier to obtain a high-molecular-weight polymetalloxane (α).

The weight average molecular weight of the polymetalloxane (α) is preferably 10,000 or more and 2,000,000 or less. By setting the weight average molecular weight of the polymetalloxane (α) within the range of 10,000 to 2,000,000, the workability of the reinforcing fiber-containing ceramic composition (X) can be improved. In particular, the spinnability of the polymetalloxane solution is exhibited, so that when the reinforcing fiber (B) described later is composed of the polymetalloxane (a), the processability of the reinforcing fiber (B) is improved. In addition, by setting the weight average molecular weight of the polymetalloxane (α) to 10,000 or more, the crack resistance of the ceramic precursor polymer (A) is improved, and even in the firing process described later, a homogeneous reinforcing material without cracks is obtained. A fiber-containing ceramic composition (X) can be obtained.

The lower limit of the weight average molecular weight of the polymetalloxane (α) as described above is more preferably 50,000 or more, particularly preferably 200,000 or more. Moreover, the upper limit of the weight average molecular weight of the polymetalloxane (α) is more preferably 1,500,000 or less, and particularly preferably 1,000,000 or less.

The weight average molecular weight in the present invention refers to a polystyrene-equivalent value measured by gel permeation chromatography (GPC). The weight average molecular weight of polymetalloxane (α) is determined by the following method. For example, 0.2 wt % of polymetalloxane (α) is dissolved in a developing solvent to obtain a sample solution. Next, the sample solution is injected into the column filled with porous gel and developing solvent. The weight average molecular weight is obtained by detecting the column eluate with a differential refractive index detector and analyzing the elution time. As the developing solvent, a solvent capable of dissolving polymetalloxane (α) at a concentration of 0.2 wt % is selected. When polymetalloxane (α) is dissolved in a solution of 0.02 mol/dm ³ of lithium chloride and N-methyl-2-pyrrolidone, this solution is used as the developing solvent.

The structural unit of the polymetalloxane (α) is not particularly limited, but the polymetalloxane (α) is a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2) Polymetalloxane having at least one of

In general formulas (1) and (2), R ¹ and R ³ are a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a substituent represented by general formula (3), or a group having a metalloxane bond. arbitrarily selected from R ² is a hydroxyl group (hydroxy group), an alkyl group having 1 to 12 carbon atoms, an alicyclic alkyl group having 5 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aromatic group having 6 to 30 carbon atoms, It is arbitrarily selected from a phenoxy group having 6 to 30 carbon atoms and a naphthoxy group having 10 to 30 carbon atoms. R ¹ , R ² and R ³ may be the same or different when a plurality of R 1 , R 2 and R 3 are present. R ⁴ is a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, an alicyclic alkyl group having 5 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aromatic group having 6 to 30 carbon atoms, and a siloxane bond. arbitrarily selected from among the groups. Metal atom M is Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Zr, Nb, Mo, In, Sn, Sb, Hf, Ta, W and Bi. The integer m is an integer indicating the valence of the metal atom M. The integer a is an integer from 0 to (m-2). The integer b is an integer from 1 to (m-2).

In general formula (3), R ⁵ and R ⁶ are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. R ⁷ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or an alkylcarbonyl group having 1 to 8 carbon atoms. c is an integer of 1-6 and d is an integer of 1-5.

Examples of alkyl groups having 1 to 12 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, s-butyl group, t-butyl group, pentyl group, hexyl group, heptyl group and octyl group. , 2-ethylhexyl group, nonyl group, decyl group, undecyl group, dodecyl group and the like.

The alicyclic alkyl group having 5 to 12 carbon atoms includes cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, cyclodecyl group and the like.

Examples of alkoxy groups having 1 to 12 carbon atoms include methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, s-butoxy, t-butoxy, pentoxy, hexyloxy, heptoxy, and octoxy. group, 2-ethylhexyloxy group, nonyl group, decyloxy group and the like.

Examples of aromatic groups having 6 to 30 carbon atoms include phenyl group, phenoxy group, benzyl group, phenylethyl group, naphthyl group and the like.

The phenoxy group having 6 to 30 carbon atoms includes phenoxy group, methylphenoxy group, ethylphenoxy group, propylphenoxy group, methoxyphenoxy group, ethoxyphenoxy group, propoxyphenoxy group and the like.

The naphthoxy group having 10 to 30 carbon atoms includes naphthoxy group, methylnaphthoxy group, ethylnaphthoxy group, propylnaphthoxy group, methoxynaphthoxy group, ethoxynaphthoxy group, propoxynaphthoxy group and the like.

In general formulas (1) and (2), when R ¹ and R ³ are groups having a metalloxane bond, R ¹ and R ³ are bonded to other polymetalloxane molecules via oxygen atoms. It means that Moreover, the case where R ⁴ in the general formula (2) is a group having a siloxane bond means that R ⁴ is bonded to another Si via an oxygen atom.

By having at least one of the structural units represented by the general formula (1) and the structural unit represented by the general formula (2), the polymetalloxane (α) and other components of the polymetalloxane (α) compatibility is improved. Therefore, it can be polymerized without precipitation during the synthesis of the polymetalloxane, which will be described later, so that the polymetalloxane (α) having a weight-average molecular weight of 10,000 or more and 2,000,000 or less can be easily obtained.

In addition, the polymetalloxane (α) has a hydroxyl group directly connected to the metal atom M contained in at least one of the structural units represented by the general formula (1) and the structural units represented by the general formula (2). is doing. In the general formulas (1) and (2), the metal atom M is a metal atom having a repeating structure of MO bonds contained in the main chain of the polymetalloxane (α). Therefore, when the polymetalloxane (α) has a structural unit represented by general formula (1), at least one of R ² in general formula (1) is a hydroxyl group. When the polymetalloxane (α) has a structural unit represented by general formula (2), at least one of R ³ in general formula (2) is a hydrogen atom. That is, at least one (--OR ³ ) group in general formula (2) is a hydroxyl group. The polymetalloxane (α) having hydroxyl groups in this way can be made into a polymetalloxane having excellent storage stability with little increase in viscosity even during long-term storage. The ceramic precursor polymer (A) containing such polymetalloxane (α) has excellent stability.

Moreover, the polymetalloxane (α) preferably has at least a structural unit represented by general formula (2). The polymetalloxane (α) having the structural unit represented by the general formula (2) has (R ⁴ ₃ SiO—) groups, thereby remarkably improving compatibility with other components. Therefore, this polymetalloxane (α) exists more stably in the organic solvent. Such a polymetalloxane (α) can contribute to the stable existence of the ceramic precursor polymer (A) in the organic solvent. Furthermore, since the polymetalloxane (α) has (R ⁴ ₃ SiO—) groups, the condensation stress of the polymetalloxane (α) is relaxed, so that a homogeneous ceramic precursor polymer ( A) can be easily obtained.

Moreover, it is particularly preferable that the polymetalloxane (α) has a structural unit represented by general formula (1) and a structural unit represented by general formula (2).

The (R ⁴ ₃ SiO—) group in general formula (2) includes a trihydroxysiloxy group, a trimethylsiloxy group, a triethylsiloxy group, a tripropylsiloxy group, a triisopropylsiloxy group, a tributylsiloxy group, a triisobutylsiloxy group, tri-s-butylsiloxy group, tri-t-butylsiloxy group, tricyclohexylsiloxy group, trimethoxysiloxy group, triethoxysiloxy group, tripropoxysiloxy group, triisopropoxysiloxy group, tributoxysiloxy group, triphenylsiloxy group a hydroxydiphenylsiloxy group, a methyldiphenylsiloxy group, an ethyldiphenylsiloxy group, a propyldiphenylsiloxy group, a dihydroxy(phenyl)siloxy group, a dimethyl(phenyl)siloxy group, a diethyl(phenyl)siloxy group, a dipropyl(phenyl)siloxy group, trinaphthylsiloxy group, hydroxydinaphthylsiloxy group, methyldinaphthylsiloxy group, ethyldinaphthylsiloxy group, propyldinaphthylsiloxy group, dihydroxy(naphthyl)siloxy group, dimethyl(naphthyl)siloxy group, diethyl(naphthyl)siloxy group, A dipropyl(naphthyl)siloxy group and the like can be mentioned.

From the viewpoint of heat resistance of the polymetalloxane (α), R ⁴ is preferably an alkyl group having 1 to 4 carbon atoms or a phenyl group. Specific examples of alkyl groups having 1 to 4 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group and t-butyl group. That is, preferred (R ⁴ ₃ SiO—) groups include trimethylsiloxy, triethylsiloxy, tripropylsiloxy, triisopropylsiloxy, tributylsiloxy, triisobutylsiloxy, tri-s-butylsiloxy, and tri-s-butylsiloxy. -t-butylsiloxy group, methyldiphenylsiloxy group, ethyldiphenylsiloxy group, propyldiphenylsiloxy group, dihydroxy(phenyl)siloxy group, dimethyl(phenyl)siloxy group, diethyl(phenyl)siloxy group, dipropyl(phenyl)siloxy group, etc. is mentioned.

The content of (R ⁴ ₃ SiO—) groups is 1 mol % or more when expressed as the ratio of the number of moles of Si (silicon atoms) to the number of moles of metal atoms M in the polymetalloxane (α). It is preferably 250 mol % or less, more preferably 10 mol % or more and 200 mol % or less. By setting the content of the (R ⁴ ₃ SiO—) group within the above range, the compatibility of the polymetalloxane (α) with other components is further improved. Therefore, this polymetalloxane (α) exists particularly stably in organic solvents.

In general formulas (1) and (2), both R ¹ and R ³ more preferably have at least one substituent represented by general formula (3). Both R ¹ and R ³ have the substituent structure represented by the general formula (3), so that even when the polymetalloxane (α) is adjusted to a high concentration, the polymetalloxane (α) Interference between them can be suppressed, and as a result, it is possible to prevent state changes such as an increase in the viscosity of the polymetalloxane (α). Although the method for synthesizing the substituent represented by general formula (3) is not particularly limited, for example, by reacting a metal alkoxide and an alcohol having a specific structure at a predetermined molar ratio, Substituents can be obtained.

Although not particularly limited, specific examples of alcohols having the above specific structure include 2-methoxyethanol, 3-methoxypropanol, 4-methoxybutanol, 5-methoxyhexanol, 1-methoxypropan-2-ol, 2-methoxy Propanol, 2-ethoxyethanol, 3-ethoxypropanol, 4-ethoxybutanol, 5-ethoxyhexanol, 1-ethoxypropan-2-ol, 2-ethoxypropanol, 2-propoxyethanol, 3-propoxypropanol, 4-propoxybutanol , 5-propoxyhexanol, 1-propoxypropan-2-ol, 2-propoxypropanol, 2-butoxyethanol, 3-butoxypropanol, 4-butoxybutanol, 5-butoxyhexanol, 1-butoxypropan-2-ol, 2 -butoxypropanol and the like.

Further, specific examples of alcohols having the above specific structure include 2-(2-methoxyethoxy)ethanol, 3-(3-methoxypropoxy)propanol, 4-(4-methoxybutoxy)butanol, 5-(5-methoxy hexyloxy)hexanol, 1-((1-methoxypropan-2-yl)oxy)propan-2-ol, 2-(2-methoxypropoxy)propanol, 2-(2-ethoxyethoxy)ethanol, 3-(3 -ethoxypropoxy)propanol, 4-(4-ethoxybutoxy)butanol, 5-(5-ethoxyhexyloxy)hexanol, 1-((1-ethoxypropan-2-yl)oxy)propan-2-ol, 2- (2-ethoxypropoxy)propanol and the like.

Further, specific examples of alcohols having the above specific structures include 2-(2-propoxyethoxy)ethanol, 3-(3-propoxypropoxy)propanol, 4-(4-propoxybutoxy)butanol, 5-(5-propoxy hexyloxy)hexanol, 1-((1-propoxypropan-2-yl)oxy)propan-2-ol, 2-(2-propoxypropoxy)propanol, 2-(2-butoxyethoxy)ethanol, 3-(3 -butoxypropoxy)propanol, 4-(4-butoxybutoxy)butanol, 5-(5-butoxyhexyloxy)hexanol, 1-((1-butoxypropan-2-yl)oxy)propan-2-ol, 2- (2-butoxypropoxy)propanol and the like.

Further, specific examples of alcohols having the above specific structure include 2-(2-(2-methoxyethoxy)ethoxy)ethanol, 3-(3-(3-methoxypropoxy)propoxy)propanol, 4-(4-( 4-Methoxybutoxy)butoxy)butanol, 5-(5-(5-methoxyhexyloxy)hexyloxy)hexanol, 1-((1-((1-methoxypropan-2-yl)oxy)propan-2-yl) oxy)propan-2-ol, 2-(2-(2-methoxypropoxy)propoxy)propanol, 2-(2-(2-ethoxyethoxy)ethoxy)ethanol, 3-(3-(3-ethoxypropoxy)propoxy ) propanol, 4-(4-(4-ethoxybutoxy)butoxy)butanol, 5-(5-(5-ethoxyhexyloxy)hexyloxy)hexanol, 1-((1-((1-ethoxypropan-2-yl )oxy)propan-2-yl)oxy)propan-2-ol, 2-(2-(2-ethoxypropoxy)propoxy)propanol and the like.

Further, specific examples of alcohols having the above specific structure include 2-(2-(2-propoxyethoxy)ethoxy)ethanol, 3-(3-(3-propoxypropoxy)propoxy)propanol, 4-(4-( 4-propoxybutoxy)butoxy)butanol, 5-(5-(5-propoxyhexyloxy)hexyloxy)hexanol, 1-((1-((1-propoxypropan-2-yl)oxy)propan-2-yl) oxy)propan-2-ol, 2-(2-(2-propoxypropoxy)propoxy)propanol, 2-(2-(2-butoxyethoxy)ethoxy)ethanol, 3-(3-(3-butoxypropoxy)propoxy ) propanol, 4-(4-(4-butoxybutoxy)butoxy)butanol, 5-(5-(5-butoxyhexyloxy)hexyloxy)hexanol, 1-((1-((1-butoxypropan-2-yl )oxy)propan-2-yl)oxy)propan-2-ol, 2-(2-(2-butoxypropoxy)propoxy)propanol and the like.

The metal atom M in the general formulas (1) and (2) described above, that is, the metal atom M in the polymetalloxane (α) is one kind of metal atom selected from the group consisting of Al, Ti and Zr. It is preferable to include the above. As a result, the metal alkoxide as a raw material for synthesizing the polymetalloxane (α) is stably present, making it easy to obtain the polymetalloxane (α) having a high molecular weight.

Further, when Zr (zirconium atom) is contained in the metal atoms M in the polymetalloxane (α), the ratio of Zr among all the metal atoms M contained in the polymetalloxane (α) is 10 mol% or more and 100 mol. % or less. By setting the ratio of Zr in the above range, crystals of zirconium dioxide are generated in the reinforcing fiber-containing ceramic composition (X). Since the melting point of zirconium dioxide is as high as 2715° C., a reinforcing fiber-containing ceramic composition (X) having excellent heat resistance can be obtained. Furthermore, it is possible to obtain a ceramic precursor polymer (A) with high toughness, thereby making it more difficult for cracks to occur during firing of the ceramic precursor polymer (A). The ratio of Zr contained in the polymetalloxane (α) is more preferably 20 mol % or more, particularly preferably 30 mol % or more.

(Method for synthesizing polymetalloxane (α))
The method for synthesizing the polymetalloxane (α) in the present invention is not particularly limited, but at least one of the compounds represented by the following general formula (4) and the following general formula (5) It is preferable to include a polycondensation step of hydrolyzing as necessary, followed by partial condensation and polymerization.

In general formulas (4) and (5), R ⁵ is the same as R ¹ in general formula (1) above, and R ⁶ is the same as R ³ in general formula (2) above. is.

In the present invention, partial condensation does not mean that all M-OH in the hydrolyzate is condensed, but part of all M-OH in the resulting polymetalloxane (α). It refers to leaving OH. Under general condensation conditions, which will be described later, it is common for some of the M-OH to remain in the polymetalloxane (α). The amount of M-OH to remain is not particularly limited.

The compound represented by the general formula (4) is not particularly limited, and examples thereof include metal alkoxides described in International Publication No. 2017/90512.

The compound represented by the general formula (5) is not particularly limited, but examples thereof include the compounds exemplified as the compound represented by the general formula (2) in the literature. Tripropoxy(trimethylsiloxy)titanium, triisopropoxy(trimethylsiloxy)titanium, tributoxy(trimethylsiloxy)titanium, tripropoxy(trimethylsiloxy)zirconium, triisopropoxy(trimethylsiloxy)zirconium, among other exemplified compounds, Tributoxy(trimethylsiloxy)zirconium, dipropoxy(trimethylsiloxy)aluminum, diisopropoxy(trimethylsiloxy)aluminum, dibutoxy(trimethylsiloxy)aluminum, and di-s-butoxy(trimethylsiloxy)aluminum are represented by the general formula (5). It is preferably used as a compound that

General methods can be used for hydrolysis, partial condensation and polymerization of the above compounds. For example, the reaction conditions for hydrolysis are preferably such that water is added to the metal alkoxide in a solvent over 1 to 180 minutes, and then reacted at room temperature to 110° C. for 1 to 180 minutes. By carrying out the hydrolysis reaction under such conditions, rapid hydrolysis reaction can be suppressed. The hydrolysis reaction temperature is preferably 30°C to 150°C. Moreover, in the case of hydrolysis, a catalyst may be added as necessary.

Further, the reaction conditions for the partial condensation and polymerization are such that after the hydrolyzate is obtained by the hydrolysis reaction of the metal alkoxide, the reaction solution is heated as it is at 50° C. to 180° C. for 1 to 100 hours. is preferred. Moreover, in order to increase the degree of polymerization of the polymetalloxane (α), it may be reheated or a catalyst may be added. Further, if necessary, after the hydrolysis reaction, an appropriate amount of the produced alcohol or the like may be distilled off by at least one of heating and pressure reduction, and then an arbitrary solvent may be added.

Although the solvent is not particularly limited, compounds having an alcoholic hydroxyl group (that is, alcoholic solvents), esters, ethers, and ketones are preferably used. By using these solvents, the stability of polymetalloxane (α) can be improved.

Examples of alcohol solvents include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, acetol, 3-hydroxy-3-methyl-2-butanone, 5-hydroxy-2-pentanone. , 4-hydroxy-4-methyl-2-pentanone (diacetone alcohol), ethyl lactate, butyl lactate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-n-butyl ether, Propylene glycol mono-t-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, dipropylene glycol monomethyl ether, 3-methoxy-1-butanol, 3-methyl-3-methoxy-1-butanol, ethylene glycol, propylene glycol, dipropylene Glycol mono-n-butyl ether, tripropylene glycol mono-n-butyl ether and the like can be mentioned.

Ester solvents include, for example, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, propylene glycol monomethyl ether acetate, 3-methoxy-1-butyl acetate, 3-methyl-3 -Methoxy-1-butyl acetate, ethyl acetoacetate, cyclohexanol acetate and the like.

Examples of ether solvents include diethyl ether, diisopropyl ether, di-n-butyl ether, diphenyl ether, diethylene glycol ethyl methyl ether, diethylene glycol dimethyl ether, 1,2-dimethoxyethane, 1,2-diethoxyethane, dipropylene glycol dimethyl ether, and the like. is mentioned.

Examples of solvents for ketones include methyl isobutyl ketone, diisopropyl ketone, diisobutyl ketone, acetylacetone, cyclopentanone, cyclohexanone, cycloheptanone, and dicyclohexyl ketone.

Other solvents that can be preferably used include, for example, propylene carbonate and N-methylpyrrolidone.

Further, the hydrolysis rate of at least one of the compound represented by the general formula (3) and the compound represented by the general formula (4) can be adjusted by adjusting the amount of water used for the hydrolysis reaction. can be done. The amount of water to be added is preferably 0.1 mol or more and 2 mol or less per 1 mol of the alkoxy group.

The catalyst added as necessary is not particularly limited, but an acidic catalyst or a basic catalyst is preferably used. Specific examples of acid catalysts include hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, phosphoric acid, acetic acid, trifluoroacetic acid, formic acid, polyvalent carboxylic acids or their anhydrides, and ion exchange resins. Specific examples of basic catalysts include triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, diethylamine, dipropylamine, dibutylamine, diisobutylamine, dipentylamine, and dihexylamine. , diheptylamine, dioctylamine, triethanolamine, diethanolamine, dicyclohexylamine, dicyclohexylmethylamine, 2,6-lutidine, 2,2,4,4-tetramethylpiperidine, 2,2,4,4-tetramethylpipe Lydone, alkoxysilanes having an amino group, and ion exchange resins can be mentioned.

Among these, more preferred catalysts are base catalysts. By using a basic catalyst, a polymetalloxane (α) having a particularly high molecular weight can be obtained. Among the base catalysts, tripropylamine, triisobutylamine, tripentylamine, triisopentylamine, trihexylamine, triheptylamine, trioctylamine, dibutylamine, diisobutylamine, dipentylamine, dihexylamine, diheptylamine, Dioctylamine, dicyclohexylamine, dicyclohexylmethylamine, 2,6-lutidine, 2,2,4,4-tetramethylpiperidine, 2,2,4,4-tetramethylpiperidone are particularly preferred.

(Organic solvent)
The ceramic precursor polymer (A) used in the reinforcing fiber-containing ceramic composition (X) according to the embodiment of the present invention preferably contains an organic solvent in addition to the polymetalloxane (α) described above. Thereby, the viscosity of the ceramic precursor polymer (A) can be adjusted to a desired viscosity. As a result, the ceramic precursor polymer (A) can have fluidity suitable for impregnation into the reinforcing fibers (B). Hereinafter, for convenience of explanation, the organic solvent contained in the ceramic precursor polymer (A) may be referred to as the organic solvent (β).

As such an organic solvent (β), a solvent contained in the polymetalloxane solution obtained in the synthesis of the polymetalloxane (α) can be used. Alternatively, the organic solvent (β) may be added to the polymetalloxane solution.

Although the organic solvent (β) is not particularly limited, it is preferably the same solvent as used in the synthesis of the polymetalloxane (α). More preferred organic solvents (β) are aprotic polar solvents. By using an aprotic polar solvent as the organic solvent (β), an interaction between the polymetalloxane (α) and the organic solvent (β) occurs. can be high. This makes it easier for the ceramic precursor polymer (A) to stay between the reinforcing fibers (B) when impregnated into the reinforcing fibers (B).

Specific examples of aprotic polar solvents include acetone, tetrahydrofuran, ethyl acetate, dimethoxyethane, N,N-dimethylformamide, dimethylacetamide (DMAc, 165°C), dipropylene glycol dimethyl ether, tetramethyl urea, diethylene glycol ethylmethyl. Ether, dimethylsulfoxide, N-methylpyrrolidone, γ-butyrolactone, 1,3-dimethyl-2-imidazolidinone, propylene carbonate, N,N'-dimethylpropylene urea and the like.

(other ingredients)
The ceramic precursor polymer (A) used in the reinforcing fiber-containing ceramic composition (X) according to the embodiment of the present invention may contain other components in addition to the polymetalloxane (α) and the like described above. good. Other components include surfactants, cross-linking agents, cross-linking accelerators, and the like.

A surfactant is preferably used to control the drying speed of the organic solvent (β) in the ceramic precursor polymer (A). The surfactant may remain in the reinforcing fiber-containing ceramic composition (X) containing the ceramic precursor polymer (A), etc., or the reinforcing fiber-containing ceramic composition (X) may be fired. may remain in the fiber-reinforced ceramic matrix composite obtained by

The type of surfactant is not particularly limited. For example, as a surfactant, "Megafac (registered trademark)" F142D, F172, F173, F183, F444, F445, F470, F475, F477 (manufactured by DIC Corporation), NBX- 15, fluorine-based surfactants such as FTX-218 and DFX-18 (manufactured by Neos), BYK-333, BYK-301, BYK-331, BYK-345, BYK-307 (manufactured by BYK-Chemie Japan), etc. Silicone-based surfactants, polyalkylene oxide-based surfactants, poly(meth)acrylate-based surfactants, and the like can be used. Two or more of these surfactants may be used.

Further, the content of the surfactant in the ceramic precursor polymer (A) is preferably 0.001 parts by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the polymetalloxane (α). It is more preferably 0.01 part by weight or more and 1 part by weight or less.

The cross-linking agent and cross-linking accelerator are preferably used to improve the strength of the sintered body of the ceramic precursor polymer (A). There are no particular restrictions on the types of cross-linking agents and cross-linking accelerators. For example, as cross-linking agents and cross-linking accelerators, mono-s-butoxyaluminum diisopropylate, aluminum-s-butyrate, ethylacetoacetate aluminum diisopropylate, aluminum tris(ethyl acetate), alkylacetoaluminum diisopropylate, aluminum mono Acetylacetonate bis (ethylacetoacetate), aluminum tris (acetylacetonate), zirconium tris (acetylacetate), zirconium tris (ethylacetoacetate), titanium tris (acetylacetate), titanium tris (ethylacetoacetate), etc. are used. be able to.

The total content of the cross-linking agent and the cross-linking accelerator in the ceramic precursor polymer (A) is 0.1 parts by weight or more and 50 parts by weight or less with respect to 100 parts by weight of the polymetalloxane (α). and more preferably 1 part by weight or more and 20 parts by weight or less. The cross-linking agent and the cross-linking accelerator may be used alone or in combination.

(Reinforcing fiber (B))
The reinforcing fiber (B) is one component constituting the reinforcing fiber-containing ceramic composition (X). In the reinforcing fiber-containing ceramic composition (X), the reinforcing fibers (B) are impregnated with the ceramic precursor polymer (A) described above. The reinforcing fibers (B) reinforce physical properties such as strength and toughness of the sintered body of the impregnated ceramic precursor polymer (A).

Examples of reinforcing fibers (B) include silicon carbide fibers (SiC fibers), metal fibers, ceramic fibers, fibers made of polymetalloxane, and fibers made of a sintered body of polymetalloxane. A known SiC fiber can be used. As the metal fibers, known metal fibers containing metals or alloys such as Al, Ti, Cr, Fe, Ni, and Cu can be used. Among these, the reinforcing fiber (B) is preferably one or more selected from ceramic fiber, polymetalloxane fiber, and polymetalloxane sintered body fiber.

From the viewpoint of high heat resistance, the ceramic fibers are preferably oxide-based ceramic fibers containing oxides of metals such as Al, Ti, and Zr. Among such oxide-based ceramic fibers, the reinforcing fibers (B) are more preferably alumina-based ceramic fibers containing an aluminum oxide such as Al ₂ O ₃ . Furthermore, from the viewpoint of availability, the reinforcing fiber (B) is particularly preferably alumina fiber or mullite fiber.

A fiber made of polymetalloxane (hereinafter referred to as a polymetalloxane fiber) is a fiber composed of a filamentous material obtained by spinning a polymetalloxane-containing composition. A polymetalloxane-containing composition is a composition containing a polymetalloxane and a component such as an organic solvent. The polymetalloxane in the polymetalloxane-containing composition may be the same as or different from polymetalloxane (a) described above. Further, the components other than polymetalloxane in the polymetalloxane-containing composition may be the same as the organic solvent (β) and other components that may be contained in the ceramic precursor polymer (A) described above. It can be different.

A known spinning method can be used in the spinning step of spinning the polymetalloxane-containing composition to obtain a filamentous material. For example, the spinning method includes a dry spinning method, a wet spinning method, a dry-wet spinning method, and an electrospinning method.

The dry spinning method is a method of filling a polymetalloxane-containing composition, extruding it into the atmosphere from a spinneret having fine pores under a load, and evaporating the organic solvent to form a filamentous material. In this method, the polymetalloxane-containing composition may be heated after filling to reduce viscosity during extrusion. Alternatively, the polymetalloxane-containing composition may be extruded into a heated atmosphere to control the evaporation rate of the organic solvent. After extruding the polymetalloxane-containing composition, the filamentous material can be stretched by rotating rollers or high-speed airflow.

Wet spinning is a method in which a polymetalloxane-containing composition is extruded from a spinneret having fine pores into a coagulation bath under a load to remove the organic solvent and form a filamentous material. Water or a polar solvent is preferably used as the coagulation bath. Dry-wet spinning is a method in which the polymetalloxane-containing composition is extruded into an atmosphere, and then immersed in a coagulation bath to remove the organic solvent to form filaments.

In the electrospinning method, by applying a high voltage to a nozzle filled with a polymetalloxane-containing composition, a charge accumulates in the droplet at the tip of the nozzle. It is a method of spinning by being stretched. With this method, it is possible to obtain filaments with a small diameter. Therefore, according to the electrospinning method, it is possible to obtain a fine filamentous material with a diameter of several tens of nanometers to several microns.

Among these, the dry spinning method or the electrospinning method can be preferably used as the spinning method in the spinning step. Moreover, in the above-mentioned spinning step, the obtained filamentous material may be subjected to drying treatment, steam treatment, hot water treatment, or a combination of these treatments, if necessary.

A fiber composed of a fired body of polymetalloxane (hereinafter referred to as a metal oxide fiber) is a fiber obtained by a method such as further firing the filamentous material of the polymetalloxane-containing composition obtained by the spinning process described above.

In the firing step for obtaining the metal oxide fiber, the filamentous material obtained by spinning in the spinning step described above is fired at a temperature of, for example, 200°C or higher and 2000°C or lower. As a result, the organic component such as the organic group is removed from the filamentous material as the cross-linking reaction progresses. As a result, a metal oxide fiber having excellent strength can be obtained. The firing temperature in this firing step is more preferably 400° C. or higher and 1500° C. or lower.

A method for firing the filamentous material in the firing step is not particularly limited. Examples of the sintering method include a method of sintering in an air atmosphere, a method of sintering in an inert atmosphere such as nitrogen or argon, and a method of sintering in a vacuum.

Moreover, in the firing step, the obtained metal oxide fibers may be further fired in a reducing atmosphere such as hydrogen. Moreover, in the firing step, the filamentous material may be fired while applying tension to the filamentous material. By such a method, continuous and dense metal oxide fibers can be obtained.

When the reinforcing fibers (B) are the metal oxide fibers described above, the polymetalloxane-containing composition used for producing the metal oxide fibers preferably contains an organic polymer. An organic polymer refers to a polymer containing carbon in its main chain. Specific examples of organic polymers include polyethylene glycol, polypropylene glycol, polyethylene oxide, polypropylene oxide, polyvinylpyrrolidone, polyvinyl alcohol, cellulose, acrylic resin, and cellulose.

The content of the organic polymer in the polymetalloxane-containing composition is preferably 1% by weight or less, and 0.5% by weight, based on the weight of the polymetalloxane contained in the polymetalloxane-containing composition. More preferably: By including the organic polymer at the above concentration, it is possible to suppress the occurrence of voids and cracks in the obtained metal oxide fiber in the above baking step. This improves the strength of the metal oxide fiber.

Moreover, the polymetalloxane-containing composition used for the production of the metal oxide fiber preferably contains neither alkali metals nor alkaline earth metals. When alkali metals or alkaline earth metals are contained in the composition, the degree of cross-linking is lowered in the baking step. Therefore, by containing neither an alkali metal nor an alkaline earth metal, a high cross-link is formed, and the strength of the obtained metal oxide fiber is improved. It is particularly preferred that the polymetalloxane-containing composition used for producing the metal oxide fiber does not contain any of Na, Mg, K and Ca atoms.

The polymetalloxane-containing composition used for producing the metal oxide fiber preferably contains no silicic acid, silicate, silica gel, silicic acid ester, boric acid, borate, or borate ester. Including the above compound in the polymetalloxane-containing composition causes the metal oxide fiber to be obtained to have a low melting point. Therefore, by not including the above compound, the metal oxide fiber has a high melting point, and the heat resistance of the metal oxide fiber is improved.

The fiber diameter of the reinforcing fibers (B) as described above is, for example, the average fiber diameter of a plurality of filamentous fibers constituting the reinforcing fibers (B), and is preferably 0.1 μm or more and 200 μm or less.

The fiber diameter of the reinforcing fibers (B) is obtained by the following method. For example, an adhesive tape is pasted on a mount, and filamentous fibers for measuring the fiber diameter are horizontally adhered thereon to obtain a fiber test piece. This fiber test piece is observed from above with an electron microscope, and the width of the image is defined as the fiber diameter. The fiber diameter is measured three times along the length direction and taken as an average value. This operation is performed on 20 randomly selected filamentous fibers, and the obtained fiber diameters are averaged to obtain the average fiber diameter.

In addition, the state of the reinforcing fibers (B) may be either a woven fabric (long-fiber fabric, etc.) or a non-woven fabric. In particular, from the viewpoint of ease of production, the reinforcing fibers (B) are preferably non-woven fabric fibers.

Further, the reinforcing fibers (B) are preferably fibers containing metal atoms such as Al, Ti and Zr. For example, the metal atoms in the reinforcing fiber (B) include the same metal atoms as those included in the polymetalloxane (α) described above. In particular, 10 mol % or more of the metal atoms contained in the reinforcing fibers (B) are preferably Al (aluminum atoms).

(Fiber-reinforced ceramic matrix composite)
A fiber-reinforced ceramic matrix composite according to an embodiment of the present invention is a composite obtained by firing the above-described reinforcing fiber-containing ceramic composition (X). That is, the fiber-reinforced ceramic matrix composite is a sintered body of the reinforcing fiber-containing ceramic composition (X) obtained by impregnating the reinforcing fiber (B) with the ceramic precursor polymer (A). Hereinafter, for convenience of explanation, the fiber-reinforced ceramics matrix composite according to the embodiment of the present invention may be referred to as a fiber-reinforced ceramics matrix composite (Z).

The fiber-reinforced ceramic matrix composite (Z) is composed of a ceramic matrix and reinforcing fibers that reinforce the ceramic matrix. The ceramic matrix of the fiber-reinforced ceramic matrix composite (Z) is the ceramic precursor polymer (A) contained in the reinforcing fiber-containing ceramic composition (X), that is, the ceramic precursor impregnated with the reinforcing fiber (B). It is a sintered body of polymer (A). The reinforcing fibers of the fiber-reinforced ceramic matrix composite (Z) are the reinforcing fibers (B) contained in the reinforcing fiber-containing ceramic composition (X).

(Manufacturing method of fiber-reinforced ceramic matrix composite)
A method for producing a fiber-reinforced ceramic matrix composite according to an embodiment of the present invention is a production method for producing a fiber-reinforced ceramic matrix composite (Z) containing reinforcing fibers (B) and a ceramic precursor polymer (A). is. This manufacturing method includes an impregnation step of impregnating the reinforcing fibers (B) with the ceramic precursor polymer (A), and a firing step of firing the ceramic precursor polymer (A) impregnated into the reinforcing fibers (B). include. Moreover, the ceramic precursor polymer (A) used in this production method contains the polymetalloxane (a) described above. Polymetalloxane (a) has a repeating structure of the above-described metal atoms and oxygen atoms, and has hydroxyl groups directly linked to the above-described metal atoms in part of the repeating structure.

(Impregnation process)
In the impregnation step in the method for producing the fiber-reinforced ceramic matrix composite (Z), the above-mentioned polymetalloxane (α) and other components such as the organic solvent (β) are mixed as necessary, thereby at least poly A solution (slurry) of ceramic precursor polymer (A) containing metalloxane (α) is prepared. After that, the woven or non-woven reinforcing fibers (B) are immersed in the solution of the ceramic precursor polymer (A). Thereby, the reinforcing fibers (B) are impregnated with the ceramic precursor polymer (A). As a result, a reinforcing fiber-containing ceramic composition (X) containing the ceramic precursor polymer (A) and the reinforcing fiber (B) is obtained.

Moreover, the method for producing the fiber-reinforced ceramic matrix composite (Z) may include a lamination step of forming a laminate of the reinforcing fiber-containing ceramic composition (X) by the impregnation step. This lamination step is performed as necessary after the impregnation step is performed and before the firing step described later.

For example, in this lamination step, a plurality of reinforcing fiber-containing ceramic compositions (X) obtained by the impregnation step are prepared, and these plurality of reinforcing fiber-containing ceramic compositions (X) are pressed into layers. As a result, a laminate can be produced by laminating a plurality of layers (for example, 2 to 5 layers) comprising the reinforcing fiber-containing ceramic composition (X). The number of laminations of the laminate may be plural, and is not particularly limited to 2 to 5 layers.

Moreover, in this lamination step, the obtained laminate of the reinforcing fiber-containing ceramic composition (X) may be cured by heat treatment. The temperature condition of this heat treatment is preferably 80° C. or higher and 300° C. or lower, for example.

(Baking process)
In the method for producing the fiber-reinforced ceramic matrix composite (Z), after the impregnation step or lamination step described above is performed, a firing step of firing the reinforcing fiber-containing ceramic composition (X) described above is performed.

In this sintering step, the reinforcing fiber-containing ceramic composition (X) obtained in the impregnation step is shaped into a desired shape such as a sheet, and then sintered by heating under predetermined temperature conditions. Thereby, the ceramic precursor polymer in the reinforcing fiber-containing ceramic composition (X), that is, the ceramic precursor polymer (A) impregnated with the reinforcing fiber (B) is fired. As a result, the ceramic precursor polymer (A) in the above state is sintered to form a sintered body, and a ceramic matrix comprising the sintered body of the ceramic precursor polymer (A) and a reinforcing material for strengthening the ceramic matrix A fiber-reinforced ceramic matrix composite (Z) containing the fibers (B) is obtained.

Alternatively, in this sintering step, the laminate of the reinforcing fiber-containing ceramic composition (X) obtained in the layering step after the impregnation step is sintered by heating under predetermined temperature conditions. As a result, the ceramic precursor polymer (A) in the laminate is sintered to produce a ceramic matrix composed of a sintered compact of the ceramic precursor polymer (A) and reinforcing fibers (B) that reinforce the ceramic matrix. A fiber-reinforced ceramic matrix composite (Z) containing and is obtained.

The firing temperature of the reinforcing fiber-containing ceramic composition (X) in the firing step is preferably 1000°C or higher and 1550°C or lower, and more preferably 1400°C or higher and 1550°C or lower. By setting the upper limit of the firing temperature to 1550° C. or less, it is possible to suppress deterioration of the reinforcing fibers (B) contained in the fiber-reinforced ceramic matrix composite (Z) due to high heat. As a result, reduction in strength of the ceramic matrix in the fiber-reinforced ceramic matrix composite (Z) due to high heat can be suppressed.

Moreover, the method for producing the fiber-reinforced ceramics matrix composite (Z) may include a densification step of densifying the fiber-reinforced ceramics matrix composite (Z) obtained by the firing step. This densification step is performed as necessary after the firing step described above is performed.

For example, in this densification step, the step of further impregnating the reinforcing fibers (B) in the fiber-reinforced ceramic matrix composite (Z) with the ceramic precursor polymer (A); A step of drying the ceramic precursor polymer (A) impregnated into the reinforcing fibers (B) and a step of firing the dried ceramic precursor polymer (A) are repeated. As a result, the sintered body (that is, the ceramic matrix) of the ceramic precursor polymer (A) contained in the fiber-reinforced ceramic matrix composite (Z) is densified, resulting in a higher strength fiber-reinforced ceramic matrix composite ( Z) can be obtained.

The firing temperature in this densification step can be set to the same temperature conditions as in the firing step described above. Moreover, each firing in the firing step and the densification step described above may be performed under any atmosphere of normal pressure, increased pressure, or reduced pressure.

As described above, the reinforcing fiber-containing ceramic composition (X) according to the embodiment of the present invention comprises the ceramic precursor polymer (A) having the polymetalloxane (α) and the reinforcing fiber (B). and the polymetalloxane (α) has a repeating structure of a metal atom and an oxygen atom selected from the specific metal atom group described above, and part of this repeating structure contains the metal It is designed to have a hydroxyl group directly connected to the atom. For this reason, the firing temperature of the reinforcing fiber-containing ceramic composition (X) can be made lower than in the case of the ceramic composition containing ceramic particles, thereby suppressing deterioration of the reinforcing fiber (B) due to high heat, and A reinforcing fiber-containing ceramic composition (X) that can stably exist in a uniform state can be obtained.

Further, the fiber-reinforced ceramic matrix composite (Z) according to the embodiment of the present invention is obtained by firing the reinforcing fiber-containing ceramic composition (X) as described above, so that it has both high strength and high heat resistance. It is possible to assume Such a fiber-reinforced ceramic matrix composite (Z) can be used as a heat insulating material or a heat radiating material for electric furnaces, building materials, etc., by taking advantage of its high heat resistance. In addition, the fiber-reinforced ceramic matrix composite (Z) can be used as members of aircraft engine turbines and the like, and members for space applications such as rockets, taking advantage of its high heat resistance and high strength properties.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Synthesis Examples and Examples, but the present invention is not limited by the following Examples.

(Materials used in Synthesis Examples and Examples)
Materials used in the Synthesis Examples and Examples below are abbreviated as follows.
DMIB: N,N'-dimethylisobutyramide (manufactured by Mitsubishi Gas Chemical Company, Inc.)
TPnB: 1-((1-((1-butoxypropan-2-yl)oxy)propan-2-yl)oxy)propan-2-ol (manufactured by Sigma-Aldrich)

(Solid content concentration)
In the following Synthesis Examples, Examples, etc., the solid content concentration of the polymetalloxane solution was obtained by the following method. Specifically, 1.0 g of polymetalloxane solution was weighed into an aluminum cup, heated at 250° C. for 30 minutes using a hot plate to evaporate the liquid content, and the solid content remaining in the aluminum cup after heating was removed. The solid content concentration of the polymetalloxane solution was determined by weighing.

(Infrared spectroscopic analysis)
Infrared spectroscopic analysis by Fourier transform infrared spectroscopy (hereinafter abbreviated as FT-IR) was performed by the following method. Specifically, first, using a Fourier transform infrared spectrometer (FT720 manufactured by Shimadzu Corporation), two stacked silicon wafers were measured and used as a baseline. Then, a drop of the metal compound or its solution was placed on a silicon wafer and sandwiched between other silicon wafers to prepare a measurement sample. The absorbance of the metal compound or its solution was calculated from the difference between the absorbance of the measurement sample and the absorbance of the baseline, and the absorption peak was read.

(Measurement of weight average molecular weight)
A weight average molecular weight (Mw) was obtained by the following method. Specifically, lithium chloride was dissolved in N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP) as a developing solvent to prepare a 0.02 mol/dm ³ solution of lithium chloride and NMP. Polymetalloxane was dissolved in a developing solvent so as to be 0.2 wt %, and this was used as a sample solution. A porous gel column (TSKgel (α-M, α-3000, one column each) manufactured by Tosoh Corporation) was filled with the developing solvent at a flow rate of 0.5 mL/min, and the sample solution (0.2 mL) was injected therein. The column eluate was detected with a differential refractive index detector (RI-201, manufactured by Showa Denko), and the weight average molecular weight (Mw) was determined by analyzing the elution time.

(Indentation test using a cylinder)
The cylinder indentation test was performed using a force tester "MCT-2150" manufactured by A&D. Specifically, a cylindrical pressure-receiving plate with a tip diameter of 15 mm was set in this force tester, and in compressive mode, the pushing strength of the sample was measured at a speed of 10 mm/m, and the breaking strength of the sample was measured. was measured.

(Synthesis example 1)
In Synthesis Example 1, tripropoxy(trimethylsiloxy)zirconium was synthesized in the same manner as in Synthesis Example 8 described in Japanese Patent No. 6,327,366.

(Synthesis example 2)
In Synthesis Example 2, di-s-butoxy(trimethylsiloxy)aluminum was synthesized. Specifically, tri-s-butoxyaluminum (24.6 g (0.1 mol)) was placed in a 500 mL three-necked flask, and the three-necked flask was immersed in an oil bath at 40° C. and stirred for 30 minutes. After that, trimethylsilanol (9.0 g (0.1 mol)) was added into the three-necked flask using a dropping funnel over 1 hour, and after the addition, the inside of the three-necked flask was further stirred for 1 hour. The content of this three-necked flask was transferred to a 200 mL eggplant-shaped flask, and the produced s-butanol was distilled off under reduced pressure to obtain a colorless liquid aluminum compound.

Infrared spectroscopic analysis of this aluminum compound by FT-IR confirmed an Al--O--Si absorption peak (949 ^cm.sup.-1 ) and no silanol absorption peak (883 cm.sup. ^-1 ). From this, it was confirmed that the obtained aluminum compound was di-s-butoxy(trimethylsiloxy)aluminum.

(Synthesis Example 3)
In Synthesis Example 3, a zirconium compound (Z-1) was synthesized. Specifically, tripropoxy(trimethylsiloxy)zirconium (35.8 g (0.1 mol)) was placed in a 500 mL three-necked flask, and the three-necked flask was immersed in an oil bath at 40° C. and stirred for 30 minutes. After that, TPnB (24.8 g (0.1 mol)) was added into the three-necked flask using a dropping funnel over 1 hour, and after the addition, the inside of the three-necked flask was further stirred for 1 hour. The content of this three-necked flask was transferred to a 200 mL eggplant-shaped flask, and the produced propanol was distilled off under reduced pressure to obtain a colorless liquid zirconium compound (Z-1).

When this zirconium compound (Z-1) was subjected to infrared spectroscopic analysis by FT-IR, the absorption (1122 cm ^-1 ) derived from propoxy decreased, and a new peak (1095 cm ^-1 ) derived from the bond between TPnB and zirconium appeared. confirmed. Moreover, since the absorption peak (968 cm ⁻¹ ) of Zr—O—Si was also confirmed, it was confirmed that the obtained zirconium compound (Z-1) was a zirconium compound having a structure represented by the following chemical formula. .

(Synthesis Example 4)
In Synthesis Example 4, a polymetalloxane (A-1) solution was synthesized. Specifically, the zirconium compound (Z-1) (54.6 g (0.10 mol)) synthesized in Synthesis Example 3 and DMIB (5.0 g) as a solvent were mixed to obtain Solution 1. . Further, water (3.60 g (0.20 mol)), isopropyl alcohol (50.0 g) as a water-diluting solvent, and tributylamine (0.37 g (0.02 mol)) as a polymerization catalyst are mixed, This was referred to as solution 2. Hereinafter, isopropyl alcohol is abbreviated as IPA.

A three-necked flask with a volume of 500 mL was charged with the entire amount of Solution 1, and this three-necked flask was immersed in an oil bath at 40° C. and stirred for 30 minutes. Then, for the purpose of hydrolysis, the dropping funnel was filled with the entire amount of solution 2, and added into the three-necked flask over 1 hour. During the addition of solution 2, precipitation did not occur in the liquid in the three-necked flask, and this solution was a uniform pale yellow transparent solution. After addition of Solution 2, stirring was continued for an additional hour to produce a hydroxy group-containing metal compound. Thereafter, the oil bath was heated to 140° C. over 30 minutes for the purpose of polycondensation. After 1 hour from the start of heating, the internal temperature of this solution reached 100° C., and the solution was heated and stirred for 2 hours. The internal temperature of the solution at this time was 100 to 130°C. IPA, propanol and water were distilled out during the reaction. During the heating and stirring, no precipitation occurred in the liquid in the three-necked flask, and the solution was a uniform transparent solution.

After heating, the solution in the three-necked flask was cooled to room temperature to obtain a polymetalloxane (A-1) solution. The appearance of the obtained polymetalloxane (A-1) solution was pale yellow and transparent. The resulting polymetalloxane (A-1) solution had a non-volatile content of 39.57% by mass and a viscosity of 304 cP.

When the polymetalloxane (A-1) solution was analyzed by infrared spectroscopy by FT-IR, the peak (1095 cm ^-1 ) derived from the bond between tripropylene glycol monobutyl ether and zirconium and the absorption peak of Zr-O-Si (968 cm ^-1 ) was confirmed. From this, it was confirmed that the polymetalloxane (A-1) in the polymetalloxane (A-1) solution was a polymetalloxane having a tripropylene glycol monobutyl ether group and a trimethylsiloxy group in its side chains. The weight average molecular weight (Mw) of polymetalloxane (A-1) was 253,000 in terms of polystyrene.

Further, when the polymetalloxane (A-1) solution was placed in a sealed container and stored at 23° C. for 7 days, the change in viscosity of the polymetalloxane (A-1) solution was less than 10%. From this, it was confirmed that polymetalloxane (A-1) is excellent in storage stability.

(Example 1)
In Example 1, 8.0 g of alumina fiber "Denka Arsen B80" (Al ₂ O ₃ : 80.3%, SiO ₂ : 19.5%) manufactured by Denka Co., Ltd. was put in a mortar and ground. A xane (A-1) solution (5.054 g (2.0 g in terms of solid content)) was added and mixed. Thus, a reinforcing fiber-containing ceramic composition (S-1) was produced.

3.0 g of the reinforcing fiber-containing ceramic composition (S-1) was placed in a hot press mold manufactured by AS ONE Co., Ltd. "Product number: 1-6002-18" and pressed at a pressure of 0.5 MPa to reduce the diameter It was molded into a 14 mm cylindrical shape. At this time, the press temperature was 100° C. and the press time was 5 minutes. The molded reinforcing fiber-containing ceramic composition (S-1) was heated at a temperature of 1100° C. for 10 minutes in an air atmosphere at a heating rate of 10° C./min using an electric muffle furnace (FUW263PA manufactured by ADVANTEC). Baked. As a result, a fiber-reinforced ceramic matrix composite (S-1A) was obtained.

Furthermore, the fiber-reinforced ceramic matrix composite (S-1A) was heated at a temperature of 1500°C in an air atmosphere at a heating rate of 3°C/min using a high-temperature heating furnace (manufactured by Chugai Prox Co., Ltd., HST125-17.5F). Bake for 60 minutes. As a result, a fiber-reinforced ceramic matrix composite (S-1B) was obtained.

Each of the obtained fiber-reinforced ceramic matrix composite (S-1A) and fiber-reinforced ceramic matrix composite (S-1B) was subjected to an indentation test using a cylinder to measure their breaking strength. As a result, the breaking strength of the fiber-reinforced ceramic matrix composite (S-1A) was 2.81 MPa, and the breaking strength of the fiber-reinforced ceramic matrix composite (S-1B) was 3.44 MPa.

In addition, the present invention is not limited to the above-described embodiment, and the present invention also includes a configuration obtained by appropriately combining each of the above-described constituent elements. In addition, other embodiments, examples, operation techniques, etc. made by those skilled in the art based on the above-described embodiments are all included in the scope of the present invention.

Claims (11)

A reinforcing fiber-containing ceramic composition containing reinforcing fibers and a ceramic precursor polymer,
The ceramic precursor polymer contains polymetalloxane,
The polymetalloxane includes Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Zr, Nb, Mo, In, Sn, Sb, Hf, Ta, Having a repeating structure of a metal atom selected from the group consisting of W and Bi and an oxygen atom, and having a hydroxyl group directly linked to the metal atom as part of the repeating structure,
A reinforcing fiber-containing ceramic composition characterized by: The metal atoms of the polymetalloxane are Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Zr, Nb, Mo, In, Sn, Sb, Two or more metal atoms selected from Hf, Ta, W and Bi,
The reinforcing fiber-containing ceramic composition according to claim 1, characterized in that: The reinforcing fiber has a fiber diameter of 0.1 μm or more and 200 μm or less.
The reinforcing fiber-containing ceramic composition according to claim 1 or 2, characterized in that: The reinforcing fiber is a non-woven fiber,
The reinforcing fiber-containing ceramic composition according to claim 1 or 2, characterized in that: The polymetalloxane has a weight average molecular weight of 10,000 or more and 2,000,000 or less.
The reinforcing fiber-containing ceramic composition according to any one of claims 1 to 4, characterized in that: 10 mol% or more of the metal atoms contained in the polymetalloxane are Zr,
The reinforcing fiber-containing ceramic composition according to any one of claims 1 to 5, characterized in that: The reinforcing fibers are one or more selected from among ceramic fibers, fibers made of polymetalloxane, and fibers made of a sintered body of polymetalloxane.
The reinforcing fiber-containing ceramic composition according to any one of claims 1 to 6, characterized in that: The reinforcing fibers contain metal atoms,
10 mol% or more of the metal atoms contained in the reinforcing fiber are Al,
The reinforcing fiber-containing ceramic composition according to claim 7, characterized in that: The reinforcing fibers are alumina-based ceramic fibers,
The reinforcing fiber-containing ceramic composition according to claim 7 or 8, characterized in that: obtained by firing the reinforcing fiber-containing ceramic composition according to any one of claims 1 to 9,
A fiber-reinforced ceramic matrix composite characterized by: A method for producing a fiber-reinforced ceramic matrix composite containing reinforcing fibers and a ceramic precursor polymer,
an impregnation step of impregnating the reinforcing fibers with the ceramic precursor polymer;
a sintering step of sintering the ceramic precursor polymer impregnated in the reinforcing fibers;
including
The ceramic precursor polymer contains polymetalloxane,
The polymetalloxane includes Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Zr, Nb, Mo, In, Sn, Sb, Hf, Ta, Having a repeating structure of a metal atom selected from the group consisting of W and Bi and an oxygen atom, and having a hydroxyl group directly linked to the metal atom as part of the repeating structure,
A method for producing a fiber-reinforced ceramic matrix composite, characterized by: