Al2O3-SiO2 compound fibre and prepn. thereof
The invention belongs to the method for preparation of inorganic composite fiber, in particular to a kind of Al2 O3-SiO2 method for producing composite fiber. Introduced in the pure alumina fiber SiO2 component, can be very effectively slow down or prevent α-Al2 O3 grain growth, thereby improving the alumina fiber mechanical performance and the purpose of the high-temperature performance, have been well known for people. However, in the alumina fiber precursor by adding silicide are usually more difficult. Added with silicon, it is difficult to dissolve; adding inorganic silicon, it is very easy to form the gel. Therefore, how to preparation is suitable for the spinning stability, a uniform, good fluidity the ALSI spinning stock solution, prepare a high-performance become an important part of the alumina fiber. Bp1, 445,331 discloses a sol chlorine oxygen aluminum method by adding water-soluble poly-siloxane. Complex synthesis of this compound, however, is not easy to obtain, the cost is also high, therefore, hard to be popularized and applied, date male illustrious 55-20339 provides a water glass as the silicon source for the composite aluminum sol preparation method, the method is the conventional water glass by adding sulfuric acid neutralization, control pH=2-4, placing 12-24 hours, silicon gel is prepared. To the sodium ion. The into a aqueous silicon gel 15-50 the fine particles of, under the condition of stirring dispersed to the aluminum sol, silicon-containing aluminum sol is made. This uses the water glass as the silicon source preparation of spinning solution, process is very complicated, not easy to operate. CN10354 79A discloses a use ethyl orthosilicate in the hydrochloric acid catalytic hydrolysis fresh silica sol prepared, by adding windows of the aluminum sol spins the medicinal preparation method of preparation of the spinning solution. The specific method is, first of all the exit in aluminum sol into polymeric, and then the presence of ethyl silicate in ethanol, hydrochloric acid as catalyst, fresh silica sol prepared by hydrolysis, of the windows with the above-mentioned polymerization spins the medicinal preparation physical mixing aluminum sol, prepared by the spinning liquid. Harsh process operation of this method, slightly discomfort conditions, is easy to produce thixotropic and the gel, unable to fiber-forming, poor stability of the spinning solution, viscosity in the fiber-forming process has been increasing in the, result in fibers with uneven thickness, and because the windows of spins the medicinal preparation aluminum sol and the prepared fresh silica sol viscosity are relatively large, is not conducive to uniform mixing of the two components, that is, the silicide is not easy to be dispersed evenly. Furthermore, used as catalyst HCl, will introduce Cl- ion, thus affecting the quality of the finished fibers. The purpose of the invention is to provide a uniform silicon-containing spinning solution, stability, good and convenient operation of the mobility Al2 O3-SiO2 method for producing composite fiber. The present invention provides the Al2 O3-SiO2 composite fiber preparation method comprises the following steps: 1.AlCl3 · 6H2 O, metal aluminum and distilled water in 60-110 the temperature of the of [...] 4-40 hours, filtered to obtain (mol ratio) Al/Cl =1.5-2.2, polymeric aluminum content is 50-95% of the polymeric structure of the aluminum oxychloride sol; 2. The polymeric structure of the above prepared sol of aluminum oxychloride, ethyl orthosilicate, alcohol solvent and polyvinyl alcohol is concentrated to obtain exit of the spinning fluid having a certain viscosity; 3. Spinning solution vacuum remove air bubbles; 4. Removing bubbles in the gel fiber spinning hydatogenesis filament prepared; 5. The gel fiber heat treatment to make compound adds the silicon alumina fiber. Characterized in that 1. Spinning solution prepared according to the following method: A. The prepared (mol ratio) Al/Cl =1.5-2.2, polymeric aluminum content is 50-95% of the polymeric structure of the aluminum oxychloride sol, ethyl orthosilicate, alcohol, by Al:Si= (5-100): 1 (mol ratio); alcohol: ethyl orthosilicate = (5-30): 1 ratio (mol ratio), in 30-90 the temperature of the of [...] 0.5-40 hours, filtering to obtain composite adds the silicon aluminum sol; B. In the composite adds the silicon aluminum sol is added to the sol in the weight of the Al 10-20%, the average polymerization degree is 1000-3000, for alcoholysis level 80-98%, concentration is 8-10% polyvinyl alcohol solution, then concentrated to viscosity is 15-90 tomari of a spinning dope; 2. The fiber-forming is adopted on the spinning device of blowing method realizes; 3. The gel fiber 60-100 the baking under [...] 20-50min, then the water vapor atmosphere, temperature is 200-400 the under the condition of [...] , processing 1-3 hours, finally in the air atmosphere, temperature is 850-1400 the under the condition of [...] , processing 10-50min. The above alcohol C1-C4 alcohol, preferably methanol, ethanol, ethylene glycol, isopropyl alcohol. The invention is to use ethyl orthosilicate in an organic solvent of the polymeric structure of the presence of aluminum sol as acidic catalytic source and water, hydrolysis to make compound adds the silicon aluminum sol is used as a main component of new process for the preparation of the spinning solution, the spinning solution is stable, transparent, good fluidity, compounding process is simple, easy to operate, compared with the water glass method, which saves the complex gel, washing, crushing process, therefore, simplifies the adds the silicon process, is favorable for production, and is compared with ethyl silicate salt acid hydrolysis, in the atomic introduction chlorineadds the silicon process, and because the silicon are introduced the of the method of the chemical reaction, so the silicon-aluminum mixed uniformity level of atomic-scale mixing can be achieved, at the same time has the advantage of simple operation, in this method instead of ethyl orthosilicate hydrochloric acid hydrolysis, the stability of the spinning solution, remarkably improved fluidity, ensures the Al2 O3-SiO2 composite fiber mechanical performance and high temperature performance. Embodiment 1 1. 120 g AlCl3 · 6H2 O (analytical pure), 500 g of distilled water, 100 g metal aluminum sheet (purity> 99.5%)adding 1000 ml of the three-port flask, the reflow temperature is 97 the reflux under [...] 6 hours, filtering to obtain Al/Cl=2.01, polymeric aluminum content of 86% chlorine oxygen aluminum solution polymerization structure; 2. Taking 15 g ethanol, 7.6 g ethyl orthosilicate, the polymeric structure of the above prepared sol chlorine oxygen aluminum of 200 g with stirring device sequentially adding 500 ml flask in three, in the 50 under [...] reflux 2 hours, filtering to obtain transparent adds the silicon composite aluminum sol; 3. In the above-mentioned composite sol adds the silicon adding 35 g concentration is 10%, is 1788 of polyvinyl alcohol, in 60 the stirring under [...] concentrated to viscosity is 20 tomari (the 20 [...]) of a spinning dope; 4. The above-mentioned spinning stock solution of degassing at room temperature under the vacuum condition of 1 hour; 5. On the spinning device the injection adds the silicon composite gel fiber; 6. The above-mentioned blowing the resulting adds the silicon composite gel fiber in 80 the baking under [...] 20 minutes, then the 360 the electrified of [...] processing low temperature furnace of the steam 2 hours, finally in the 950 the roasting under [...] 40 minutes, more Al2 O3-SiO2 composite fiber, fibrous can see table 1. Embodiment 2 The embodiment 1 the resulting Al2 O3-SiO2 fiber in 1200 the roasting under [...] 50 minutes, the resulting fibrous can see table 1. Embodiment 3 The embodiment 1 the resulting Al2 O3-SiO2 composite fiber in 1300 the roasting under [...] a half hours, the resulting fibrous can see table 1. Embodiment 4 1. The 120 g AlCl3 · 6H2 O (analytical pure), 576 g distilled water, 120 g metal aluminum sheet (purity)> 99.5%)adding 1000 ml flask in three, in 95 the reflux under [...] 10 hours, to obtain Al/Cl=2.15 polymeric aluminum content of 89% aluminum sol polymerization structure; 2. Taking 40 g glycol, 22.14 g ethyl orthosilicate, the above-mentioned polymeric structure of the aluminum sol 200 g with stirring device sequentially adding 500 ml flask in three, in 80 the reflux under [...] 5 hours, filtering to obtain transparent adds the silicon composite aluminum sol; 3. In the above-mentioned preparation of the composite aluminum solution adds the silicon adding 42 g concentration is 10%, is 1788 of polyvinyl alcohol, in 60 the stirring under [...] concentrated to viscosity is 20 tomari (the 20 [...]) of a spinning dope; 4. The above-mentioned spinning stock solution of degassing under the vacuum condition of 1 hour; 5. Degassing after the spinning device of the spinning solution the injection adds the silicon composite gel fiber; 6. The above-mentioned blowing the adds the silicon composite gel fiber according to the embodiment 1 a heat treatment step after the heat treatment is carried out, in the 1300 the roasting under [...] 30 minutes, to obtain Al2 O3-SiO2 composite fiber, fibrous can see table 1. Embodiment 5 1. The 120 g AlCl3 · 6H2 O (analytical pure), 600 g of distilled water, 60 g metal aluminum sheet (purity)> 99.5%)adding 1000 ml flask in three, in 80 the reaction [...] 25 hours, filtering to obtain Al/Cl=1.6, polymeric aluminum content of 57% polymerization structure aluminum sol; 2. Taking ethyl orthosilicate 3.29 g, ethanol 10 g, the polymeric structure of the prepared aluminum sol 200 g are successively added into a 500 ml with stirring device of the three-port flask, the reflow temperature is 85 the reflux under [...] 2 hours, filtering to obtain transparent adds the silicon composite aluminum sol; 3. The above prepared to the concentration of the composite aluminum sol adds the silicon 10% of 1788 polyvinyl alcohol 25 g, in the 60 the concentrated [...] to viscosity is 20 tomari (the 20 [...]) of a spinning dope; 4. The above-mentioned spinning stock solution of degassing under the vacuum condition of 1 hour; 5. The spinning device is blowing resulting gel fiber; 6. According to the embodiment of the above-mentioned gel fiber 1 heat treatment step handled Al2 O3-SiO2 composite fiber, fibrous can see table 1. example example 6 (According to the CN 1035479A method of preparation) 1. Taking 120.7 g AlCl3 · 6H2 O dissolved in 400 ml distilled water, is poured into the have been added for purity 99.5% metal scraps 67.7 g in round-bottom flask, then adding 1000 ml distilled water, of the ordinary return device for the 100 [...] of the 24 hours, then filtering to obtain Al/Cl=2.0 of aluminum oxychloride sol; 2. In the above-mentioned aluminum sol by adding 300 g concentration is 3% for the alcoholysis degree of 88%, average polymerization degree is 1750 ±50 polyvinyl alcohol, add 0.8 ml isobutyl alcohol; 3. Taking 26.5 g ortho-silicate the ethyl ester uses 6.5 g ethanol little stirring dissolution, dripping 6N hydrochloric acid 0.5 g, and add 20 ml distilled water, after about 10 minutes to hydrolyze and get the fresh silicon sol; 4. The fresh silica sol under stirring condition is poured into the above-mentioned aluminum sol, then in 85 the viscosity of concentrated to under [...] the 20 when [...] 18 tomari; 5. Spinning on the spinning device shall adds the silicon composite gel fiber; 6. The spinning of the gel fiber, in the first 60 the roasting under [...] 30 minutes, and then the the 340 [...] containing water vapor of the treatment of the treatment in the furnace 20 minutes, to obtain a composite aluminum oxide fiber green brown , finally, in the 1300 roasting under [...] 30 minutes to obtain silicon-containing alumina fiber. Fibrous can see table 1. Embodiment 7 According to the embodiment 6 of the water vapor produced and after processing the compound aluminum oxide fiber 850 the roasting under [...] 30 minutes to obtain silicon-containing alumina fiber. Fibrous can see table 1. Table 1 fiber performance 1. The average grain size of the crystalline phase is the measured X-ray diffraction method. 2. An average diameter of: the the magnification of 1000 times of gangnam XSX-2 phase contrast biomicroscopic directly measure the diameter of each fiber, 100 which is the arithmetic mean of the diameter of fibers of the average diameter of the fiber. 3. Alumina fibrofelt tensile strength, of the bicycle design "fiber the felt pulls anti- strength tester" for on. A Al2 O3-SiO2 method for producing composite fiber, is ethyl silicate to presence of the organic solvent of the polymeric structure of aluminum sol as acidic catalytic source and water, hydrolysis to make compound adds the silicon aluminum solution as the main component of the new process for preparation of the spinning solution, the spinning solution is stable, transparent, good fluidity, compounding process is simple, convenient operation, ensures the Al2 O3-SiO2 composite fiber mechanical performance and high temperature performance. 1. A Al2 O3-SiO2 preparation method of composite fibers, comprising the following steps: (1) AlCl3 · 6H2 O, metal aluminum and distilled water in 60-110 the temperature of the of [...] 4-40 hours, filtered to obtain the molar ratio of Al/Cl 1.5-2.2, polymeric aluminum content is 50-95% of the polymeric structure of the aluminum oxychloride sol; (2) polymerization of the above-mentioned structure of the prepared aluminum oxychloride sol, ethyl orthosilicate, alcohol solvent and polyvinyl alcohol exit with a certain degree of viscosity is obtained through concentration of the spinning solution; (3) spinning solution vacuum remove air bubbles; (4) get rid of bubbles in the gel fiber spinning hydatogenesis filament prepared; (5) the gel fiber heat treatment to make compound adds the silicon alumina fiber; Characterized in that (1) spinning solution prepared according to the following method: A. The prepared Al/Cl molar ratio of 1.5-2.2, polymeric aluminum content is 50-95% of the polymeric structure of the aluminum oxychloride sol, ethyl orthosilicate, alcohol, by Al: the molar ratio of Si (5-100): 1 ; ethanol: ethyl orthosilicate in a molar ratio of (5-30): 1 ratio, in 30-90 the temperature of the of [...] 0.5-40 hours, filtering to obtain composite adds the silicon aluminum sol; B. In the composite adds the silicon aluminum sol is added to the sol in the weight of the Al 10-20%, the average polymerization degree is 1000-3000, for alcoholysis level 80-98%, concentration is 8-10% polyvinyl alcohol solution, then concentrated to viscosity is 15-90 tomari of a spinning dope; (2) the fiber-forming is adopted on the spinning device of blowing method realizes; (3) the gel fiber 60-100 the baking under [...] 20-50min, then the water vapor atmosphere, temperature is 200-400 the under the condition of [...] , processing 1-3 hours, finally in the air atmosphere, temperature is 850-1400 the under the condition of [...] , processing 10-50min. " 2. A Al2 O3-SiO2 according to Claim 1 preparation of a composite fiber, is characterized in that the alcohol is C1-C4 alcohol. 3. A Al2 O3-SiO2 as in Claim 1 or Claim 2 preparation of a composite fiber, is characterized in that the alcohol is methanol, ethanol, ethylene glycol, isopropyl alcohol.
The tabular data by test method: Fiber component Al2 O3-SiO2 (weight ratio) 100 the [...] 5 The 100 [...] 5 The 100 [...] 5 The 100 [...] 15 The 100 [...] 3 The 100 [...] 5 The 100 [...] 5 An average diameter (μ) 3 3 3 3 3 2-4 2-4 Crystalline phase γ Δγ Δθ Δθ Θα Δθ Η Average grain d (A) 80 140 190 170 390 240 67 Fibrofelt tensile strength (Newtons/ gram type) 40 35 29 20 18 10.3 37 Apparent good Good Good Good Good General Good