JPH05105762A - Silicon-based hybrid material - Google Patents

Abstract

PURPOSE:To obtain the subject lightweight and, high-toughness material excellent in resistance to heat, combustion and environment, having high mechanical strength and good molding processability by reaction of a silicate with a silicon- based polymer having SiH groups in the molecule. CONSTITUTION:The objective hybrid material suitable as a structural material for aerospace applications, internal trim member or medical material is obtained by reaction of (A) a silicate such as olivine group or lithium metasilicate with (B) a silicon-based polymer such as polysiloxane or polycarbosilane in the presence of a catalyst such as FeCl3.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention is excellent in heat resistance, combustion resistance and environment resistance obtained by reacting silicates with a silicon-based polymer having at least two SiH groups in the molecule. The present invention relates to a silicon-based hybrid material that is lightweight and has high toughness, high mechanical strength, and good moldability.

[0002]

2. Description of the Related Art At present, various types of materials are used as silicon materials in view of their characteristics and required performance. Silicon-containing ceramics such as silicon carbide, silicon nitride, and silicon oxide, and various silicates are materials having excellent mechanical strength, chemical stability, and thermal stability. However, these inorganic silicon compounds are generally hard and brittle, and have extremely poor moldability, so that their use is limited.

So-called organosilicon polymers such as polysiloxanes, polycarbosilanes, polysilanes, and polysilazanes, which contain silicon in the main chain skeleton, are generally superior in molding processability to inorganic silicon compounds, but their mechanical properties are high. Its range of use is limited due to its markedly poor strength.

[0004]

Means for Solving the Problems As a result of earnest research in view of such circumstances, the present inventors have solved these problems and have excellent heat resistance and combustion resistance, high toughness and high mechanical strength. The present invention provides a silicon-based hybrid material having moldability. That is, the present invention relates to a silicon-based hybrid material obtained by reacting silicates with a silicon-based polymer having at least two SiH groups in the molecule in the presence of a catalyst.

The silicates used in the present invention are components for imparting heat resistance, combustion resistance, environment resistance, and high strength to the silicon-based hybrid material obtained in the present invention, and there are no particular restrictions, and various silicates are used. Things can be used.

To give a concrete example, (1) olivine (F)
e, Mg) ₂ SiO ₄ , garnet group Mg ₃ Al ₂ Si ₃
O ₁₂ , Ca ₃ Al ₂ Si ₃ O ₁₂ , Zircon ZrSi
Nesosilicates such as O ₄ , pearlite, silica gemstone, orthite, mullite, topaz, cruciate, sapphirine, norbergite, chondroite, fume stone, clinocline fumestone, wedge stone, chloritoid, etc. (2) Such as feldspar group, chlorite group, lawsonite, pumpellyite and other solosilicates, (3) quincerite, tourmaline beryl and other cyclosilicates, (4) feldspar, semi-feldspar, zeolites, etc. Tectosilicate, (5)
Inosilicate, (6) Lithium metasilicate Li ₂ Si
O ₃ , sodium metasilicate Na ₂ SiO ₃ , potassium metasilicate K ₂ SiO ₃ , magnesium metasilicate Mg
SiO ₃ , calcium calcium metasilicate Na ₂ Si
O ₃ -CaSiO _3, calcium metasilicate CaSiO
₃ , magnesium calcium metasilicate CaMgSi ₂
O ₅ , barium metasilicate BaSiO ₃ , manganese metasilicate MnSiO ₃ , iron metasilicate FeSiO ₃ , cobalt metasilicate CoSiO ₃ , lead metasilicate PbSiO.
_{3, CaMgSi 2 O 6 -MgSi 2} O 6 solid solution, Ca
Examples include metasilicates such as MgSi ₂ O ₆ —FeSi ₂ O ₆ solid solution and solid solutions thereof, and (7) phyllosilicates such as muscovite group and biotite group.

Of these, lithium metasilicate Li ₂
SiO ₃ , sodium metasilicate Na ₂ SiO ₃ , potassium metasilicate K ₂ SiO ₃ , magnesium metasilicate MgSiO ₃ , sodium metasilicate calcium Na ₂
SiO ₃ -CaSiO _3, calcium metasilicate CaS
iO ₃ , magnesium calcium metasilicate CaMgS
Metasilicates such as i ₂ O ₅ are preferably used.
Further, an aqueous solution of sodium metasilicate (so-called water glass) is particularly preferably used.

At least 2 in the molecule used in the present invention
The silicon-based polymer having individual SiH groups is a component that imparts toughness, lightness, and moldability to the silicon-based hybrid material obtained in the present invention, and has a silicon atom in the main chain skeleton. , Can be used without particular limitation.

The SiH group may exist randomly in a pendant type in the main chain of the silicon-based polymer, or may exist at the molecular end. The number of SiH groups should be at least two in the molecule, but preferably two or more 30
Not more than one. If the number of SiH groups is one, the strength of the silicon-based hybrid material obtained by the present invention is not sufficient, and S
When the number of iH groups is more than 30, the toughness of the obtained silicon-based hybrid material becomes insufficient, resulting in a very brittle material.

Although the molecular weight is not particularly limited, it is generally from 1000 to 5000 in consideration of the compatibility with silicates and the performance of the obtained silicon-based hybrid material.
Those of about 00 are preferably used. The main chain skeleton of the silicon-based polymer used here may be linear, ladder-like, branched or cage-like. In view of reactivity with silicates and performance of the resulting silicon-based hybrid material, linear or ladder-shaped ones are preferably used.

At least 2 in the molecule used in the present invention
Examples of the silicon-based polymer having one SiH group include polysiloxanes, polycarbosilanes, polysilanes, polysilazanes, and silicon-based polymers having two or more kinds of their main chain skeletons in one molecule. Polymers and the like can be mentioned.

A specific example will be described below. The following are specific examples of polysiloxanes.

[Chemical 1]

[0013]

[Chemical 2] However, the present invention is not limited to these.

The term "polycarbosilanes" as used in the present invention means that the main chain skeleton is composed of silicon and carbon atoms and contains silicon including a polymer having an Si-Si, C-C bond in the main chain. Means a polymer. Specific examples of the polycarbosilanes include those having a repeating unit represented by the following formula.

[0015]

[Chemical 3]

[0016]

[Chemical 4] R ₁ and R ₂ listed here are H, CH ₃ , CH ₂ CH.
₃ or a phenyl group is preferred. R ₃ has 4 to 4 carbon atoms
Cyclic hydrocarbons of 6 are preferred. n is preferably 1-6.

The polycarbosilanes used in the present invention may be a polymer composed of one type of the repeating unit or a copolymer composed of two or more types of repeating units.

Of these, preferred structural formulas are given below.

[Chemical 5] And so on.

Polycarbosilanes having the following repeating units can also be used.

[0020]

[Chemical 6]

In the above formula, R is preferably H, CH _{3 or} a phenyl group. As a concrete structural formula,

[0022]

[Chemical 7]

[0023]

[Chemical 8] And the like.

As the repeating unit constituting the polysilane,

[Chemical 9]

[0025]

[Chemical 10]

And the like. These repeating units may be homopolymers or copolymers of two or more kinds, but it is necessary that they have at least two SiH groups in one molecule of the polysilane to be constituted.

As the repeating unit constituting the polysilazanes,

[Chemical 11]

And the like. These repeating units may be homopolymers or copolymers of two or more kinds, but at least 2 units are contained in one molecule of the polysilazane.
It is necessary to have 4 SiH groups.

The ratio of the silicates used in the present invention and the silicon-based polymer having at least two SiH groups in the molecule is a very important index for controlling the properties of the obtained silicon-based hybrid material. is there. Since the silicon content of silicates varies depending on the type, the same number of moles of SiO as the silicon atoms contained in the silicates used.
_It is convenient to use the weight ratio of dimer and silicon-based polymer. The weight ratio (weight of SiO ₂ / silicon-based polymer) is usually in the range of 0.1 to 100 and can be preferably used.
More preferably 0.2 to 80, particularly preferably 0.5.
The range is from -50. When the weight ratio is less than 0.1, the strength of the obtained silicon-based hybrid material is insufficient,
If it is more than 100, the obtained silicon-based hybrid material becomes brittle.

In the reaction of the silicates with the silicon-based polymer having at least two SiH groups in the molecule, the reaction form is not particularly limited, but these components are required to effectively promote the reaction. Is preferably reacted in a liquid phase homogeneous system. In view of this point, among various silicates, the alkali metal salt is water-soluble and can be preferably used. Further, silicates other than alkali metal salts may be used because they become water-soluble alkali salts by melting with alkali.

An aqueous solution of silicates is generally alkaline, but an aqueous solvent such as an alcoholic solvent such as methanol, ethanol, isopropanol, n-propanol, n-butanol or ethyl cellosolve, an ether solvent such as THF or dioxane, etc. At least two silicon-based polymers in the molecule may be dissolved in an organic solvent and reacted in the presence or absence of a catalyst. Alternatively, a silicic acid solution obtained by neutralizing an aqueous solution of silicates and extracting with a solvent may be used to react with at least two silicon-based polymers in the molecule or a solution thereof in the presence or absence of a catalyst. As the neutralizing agent used in this case, sulfuric acid, hydrochloric acid, acetic acid, etc. are used, and as the extraction solvent, an alcoholic solvent such as methanol, ethanol, isopropanol, n-propanol, n-butanol, and ethyl cellosolve, THF, Ethereal solvent such as dioxane,
Although THF can be preferably used, it is not limited thereto.

In general, since the silicon-based polymer having at least two SiH groups in the molecule used in the present invention is hydrophobic, when it is reacted with an aqueous solution of silicates, a non-uniform state is formed and a partial gelation occurs. In many cases, only non-uniform materials can be obtained. Therefore, from the viewpoint of maintaining the uniformity of the reaction, it is preferable to carry out the reaction using a neutralizing / extracting solution of silicates.

In the present invention, in reacting the silicates with the silicon-based polymer having at least two SiH groups in the molecule, the reaction rate can be controlled by using various catalysts.

In general, the following catalysts can be used, but the catalysts are not limited to these. FeC
l ₃ , ZrOCl ₂ , BaCl ₂ , CaCl ₂ , PbC
l ₂ , PdCl ₂ , SnCl ₂ , CuCl ₂ , CuC
1, BiCl ₃ , NiCl ₂ (PPh ₃ ) ₂ , CoCl
₂ 6H ₂ O, H ₂ PtCl ₆ 6H ₂ O, AlBr ₃ , B
F ₃ O (C ₂ H ₅ ) ₂ , MgBr ₂ 6H ₂ O, AlCl
₃ , MgCl ₂ 6H ₂ O, MgCl ₂ , ZnCl ₂ , N
Metal halides such as iCl ₂ and LiCl or inorganic acids such as Lewis acid, hydrochloric acid, sulfuric acid, phosphoric acid and chloroplatinic acid; titanic acid esters such as tetrabutyl titanate and tetrapropyl titanate; dibutyltin dilaurate, dibutyltin maleate, dibutyltin dichloride Tin carboxylates such as acetate, tin octylate, tin naphthenate; reaction products of dibutyltin oxide and phthalic acid ester; dibutyltin diacetylacetonate; aluminum trisacetylacetonate, aluminum trisethylacetoacetate, diisopropoxyaluminum ethylacetoacetate. Organoaluminum compounds such as; Chelate compounds such as zirconium tetraacetylacetonate and titanium tetraacetylacetonate; Octylic acid Butylamine, octylamine, dibutylamine, monoethanolamine, diethanolamine, triethanolamine, diethylenetriamine, triethylenetetramine, oleylamine, cyclohexylamine, benzylamine, diethylaminopropylamine, xylylenediamine, triethylenediamine, guanidine, diphenylguanidine, 2 , 4, 6
-Tris (dimethylaminomethyl) phenol, morpholine, N-methylmorpholine, 2-ethyl-4-methylimidazole, 1,8-diazabicyclo (5,4,0)
Amine compounds such as undecene-7 (DBU) or salts thereof with carboxylic acids; low molecular weight polyamide resins obtained from excess polyamine and polybasic acid; reaction products of excess polyamine and epoxy compound; amino Examples thereof include a silane coupling agent having a group, such as γ-aminopropyltrimethoxysilane and N- (β-aminoethyl) aminopropylmethyldimethoxysilane. Further, other known silanol condensation catalysts and the like can be mentioned. These catalysts may be used alone or in combination of two or more.

In the reaction between the neutralized / extracted solution of the silicate aqueous solution and the silicon-based polymer having at least two SiH groups in the molecule, the condensation reaction is not completed even after the reaction is completed, and the silanol group is added to the reaction system. Often remains. The residual silanol groups are further condensed when the volatile components are removed in a later step described later, but the silanol groups are not completely consumed. However, the objects of the present invention can be generally achieved.

Depending on the application, it may not be desirable for the silanol groups to remain in the final material. In that case, various types of chlorosilanes, alkoxysilanes, silanols, etc., are used as silanols remaining in the reaction system. The group can be trapped. As an example of chlorosilanes, Me ₃ SiCl, PhMe ₂ SiCl, P
h ₂ MeSiCl, Me ₂ SiCl ₂ , PhMeSiC
l ₂ , Ph ₂ SiCl ₂ , MeSiCl ₃ , PhSiC
l ₃ , ClMe ₂ SiC ₆ H ₄ SiMe ₂ Cl, ClM
e ₂ SiOSiMe ₂ Cl, ClMe ₂ SiCH ₂ Si
Me ₂ Cl, ClMe ₂ SiCH ₂ CH ₂ SiMe ₂ C
1, ClMe ₂ SiSiMe ₂ Cl, Cl ₂ MeSiS
Examples of alkoxysilanes such as iMe ₂ Cl, Cl ₂ MeSiSiMeCl ₂ , polydimethylsiloxane having both ends SiMe ₂ Cl include Me ₃ SiOMe, P.
hMe ₂ SiOMe, Ph ₂ MeSiOMe, Me ₂ S
i (OMe) ₂ , PhMeSi (OMe) ₂ , Ph ₂ S
i (OMe) ₂ , MeSi (OMe) ₃ , PhSi (O
Me) ₃ , MeOMe ₂ SiC ₆ H ₄ SiMe ₂ OM
e, MeOMe ₂ SiOSiMe ₂ OMe, MeOMe
₂ SiCH ₂ SiMe ₂ OMe, MeOMe ₂ SiCH
₂ CH ₂ SiMe ₂ OMe, MeOMe ₂ SiSiMe
₂ OMe, (MeO) ₂ MeSiSiMe ₂ OMe,
(MeO) ₂ MeSiSiMe (OMe) ₂ , both ends S
Examples of silanols such as polydimethylsiloxane of iMe ₂ OMe include Me ₃ SiOH, PhMe ₂
SiOH, Ph ₂ MeSiOH, HOMe ₂ SiC ₆ H
₄ SiMe ₂ OH, HOMe ₂ SiOSiMe ₂ OH,
HOMe ₂ SiCH ₂ SiMe ₂ OH, HOMe ₂ Si
CH ₂ CH ₂ SiMe ₂ OH, HOMe ₂ SiSiMe
Examples thereof include, but are not limited to, ₂ OH and polydimethylsiloxane having SiMe ₂ OH at both ends.

Further, since HCl is generated when these trapping agents, especially chlorosilanes, are used, neutralization may be carried out using triethylamine, pyridine or the like.

As a post-treatment step for obtaining the silicon-based hybrid material of the present invention, a reaction mixture of silicates and a silicon-based polymer having at least two SiH groups in the molecule is treated at a temperature from room temperature to about 100 ° C. Membranous in range,
A process of forming into a fibrous, plate-shaped, rod-shaped or other complicated shape
A step of removing volatile components from the reaction mixture is included.
Of these, curing shrinkage and compaction of the molded body occur in the step of removing volatile components, so that the step has a great influence on the performance of the obtained silicon-based hybrid material. Generally, it is preferable to gradually remove the volatile components in order to minimize the strain remaining inside the molded body. At that time, changing the temperature / pressure may be used. Further, firing may be performed for the purpose of improving the physical properties of the obtained silicon-based hybrid material.

The silicon-based hybrid material of the present invention is produced by using silicates and a silicon-based polymer as main components. In addition to the basic components, various kinds of silicon-based hybrid materials can be adjusted for the purpose of adjusting the characteristics of the obtained silicon-based hybrid material. Additives and reinforcing agents can be used. The additives / reinforcing agents can be added as required at the time of the reaction of the above-mentioned basic components, at the stage where their condensation reaction has progressed to a certain extent, at the stage of removing volatile components, and the like.

As specific examples of additives and reinforcing agents that can be used in the present invention, various metal alkoxides or hydroxides other than alkoxysilanes may be used in combination. Specific examples of these compounds are Al (OiP
r) ₃ , Ti (OiPr) ₄ , Ti (OnBu) ₄ , B
(OEt) ₃ , Zr (OPr) ₄ , Ti (OSiM
e ₃ ) ₄ , (Me ₃ SiO) ₂ Ti (OiPr) ₂ , B
Various metal alkoxides such as (OH) ₃ , hydroxides, glass fibers, alumina fibers, carbon fibers, boron fibers, silicon carbide fibers, silicon nitride fibers, tyranno fibers, and other inorganic fibers, aramid fibers,
Nylon fiber, vinylon fiber, polyester fiber, polyarylate fiber, ultra high molecular weight polyethylene fiber, poly-
Chop-shaped, yarn-shaped, woven-shaped or mat-shaped organic fibers such as p-benzamide and polyamide hydrazide, asbestos, mica, talc and mixtures thereof, calcium carbonate, alumina, silica, clay, titanium oxide , Carbon black and the like.

The silicon-based hybrid material of the present invention thus obtained can be used for various purposes. Concrete examples are aerospace structural materials used for satellites, space shuttles, space colonies, aircraft and rocket fuselage, engine peripheral parts, automobile outer plates, cylinder heads, wheel caps, propeller shafts, engine surroundings. Materials / Interior materials / Bicycle tire frames / Linear motor car materials / Other structural materials used in various transportation equipment such as automobiles, motorcycles, bicycles, tricycles, railroads, ships, agricultural equipment such as tractors, housing, etc. Structural materials used for buildings, bridges, pedestrian bridges, ladders, skyscrapers, deep underground structures, undersea structures, boats, yachts, skis, snowmobiles, etc.
Sports equipment such as glider aircraft, tennis rackets, golf shafts, fishing rods, and tent posts, household appliances such as microwave ovens, refrigerators, washing machines, personal computers, medical materials such as artificial bones, artificial teeth and artificial roots, and cosmetics Materials, sealing materials, adhesives, adhesives, adhesives,
Paints, modifiers, plasticizers, masking materials, mold release materials, defoaming materials, fiber treatment materials, electrical insulation materials, semiconductor encapsulation materials, ceramic fibers and precursors for molded products, RIM / LIM / injection / extrusion / blowing・ Molding material for compression, shape memory material, optical fiber, laser disk optical memory film, photochromic glass, optical switch, refractive index distribution glass, heat ray blocking glass, reflector, antireflection glass, optical-related functionality such as optical disk substrate Functional glass for electromagnetic fields such as glass, TV image pickup tube devices, solid state batteries, delay line glass, displays, etc., heat-resistant materials, photomask substrates, functional glass for heat-related applications such as adhesion and adhesion, high temperature separation and purification,
Examples thereof include functional glass for chemicals such as enzyme immobilization and solidification of radioactive waste, but are not limited to these.

[0042]

EXAMPLES The present invention will be specifically described below with reference to examples, but the contents of the present invention are not limited thereto. Production Example 1 500 L of 0.80 mol / L sodium silicate aqueous solution in 0.64 mol / L sulfuric acid 1.1 L (0.74 mol)
l (using SiO ₂ 0.40 mol, Chemical Industry JIS3 No. products directly.) was added dropwise with stirring to neutralize. Then add tetrahydrofuran (THF) 8 to the solution.
After adding 00 ml and stirring at room temperature for 2 hours, the mixture was transferred to a separating funnel, 400 g of sodium chloride was added, and the mixture was shaken.
The upper layer was separated, anhydrous sodium sulfate was added, and the mixture was left overnight and dehydrated and dried. This is filtered and silicic acid-THF solution 6
00 ml was obtained. This SiO ₂ concentration is 0.086 g / m
It was l.

Production Example 2 8.4 g (0.1 mol) of 1,5-hexadiene and 10 wt% isopropanol solution of chloroplatinic acid catalyst 10.4
HMe [mu] l of (2x10 ^-3 mmol, 1x10 ^-5 molvs olefin 1 mol) in a solution prepared by dissolving in dry chloroform 30ml ₂ SiPhSiMe ₂ H 21.
34 g (0.11 mol) of dry chloroform 10 ml
The solution dissolved in was slowly added dropwise at room temperature under a nitrogen atmosphere. The dropping rate was adjusted so that a mild exothermic reaction was maintained during the dropping. After completion of dropping, the reaction solution was stirred at room temperature for 1 hour. The platinum catalyst used was removed by passing the reaction solution through a silica gel column. When the volatile components were evaporated, a crude polymer having a Si group terminal was obtained as a white solid. The crude polymer was purified by reprecipitation from methylene chloride / methanol and dried under reduced pressure to obtain about 19.5 g (about 70% yield) of Si group-terminated polycarbosilane polymer having the following structural formula. The number average molecular weight measured by GPC is 450.
0, the weight average molecular weight was 10,000.

[0044]

[Chemical 12]

Example 1 In 200 ml of the silicic acid-THF solution (SiO ₂ content: 17.2 g) synthesized in Preparation Example 1, polydimethylsiloxane having a SiH group at the molecular end with a molecular weight of about 17,500 (PS542, Chisso (stock) )) 20 g of a 30 wt% solution of THF was added at room temperature, and well stirred until almost uniform. 6 ml of 0.3 N HCl aqueous solution was added to the mixed solution at room temperature with vigorous stirring. Evolution of hydrogen and a mild exotherm were observed. The reaction was carried out at room temperature for 1 hour and at 50 ° C. for 3 hours. The reaction solution was concentrated until the solid content concentration became about 20%. The concentrated solution was poured to a depth of 10 mm in a 100 × 25 × 25 mm mold frame which was previously covered with a Teflon sheet. Do this for 1 week at room temperature and 3 at 50 ° C.
A plate-like silicon-based hybrid material having a thickness of about 2 mm was obtained by drying for one day. The material was as strong as ordinary glass and did not break brittle. As a result of thermogravimetric analysis (TGA), it was found that the silicon-based hybrid material had excellent heat resistance.

Example 2 TH of the Si-terminated polycarbosilane produced in Production Example 1
A plate-shaped silicon-based hybrid material was obtained in exactly the same manner as in Example 1 except that 25 g of a F30 wt% solution was used. This material was as strong as glass and did not undergo brittle fracture. As a result of thermogravimetric analysis (TGA), it was found that the silicon-based hybrid material had excellent heat resistance.

Comparative Example 1 A plate-shaped molded article was prepared in the same manner as in Example 1 except that a silicon-based polymer having at least two SiH groups in the molecule was not used. After being removed, it became powdery and a molded body could not be obtained.

[0048]

According to the present invention, it is possible to provide a silicon-based hybrid material which is excellent in heat resistance, combustion resistance and environment resistance, is lightweight and has high toughness, high mechanical strength and good moldability.

Claims (1)

[Claims] 1. A silicon-based hybrid material obtained by reacting a silicate with a silicon-based polymer having at least two SiH groups in the molecule.