METHOD FOR PRODUCING A HIGH TEMPERATURE RESISTANT, HEAT INSULATING, AND FIREPROOF COMPOSITE GLUE COMPOSED OF AN AEROGEL AND AN INORGANIC FIBER AND THE APPLICATION OF THE RELATED PRODUCT

Abstract

A method for producing a composite glue composed of an aerogel, an inorganic fiber, and an inorganic adhesive includes the following steps of: (1) mixing step, (2) hydrolysis step, (3) condensation step, (4) aging step, (5) high-temperature solvent replacement step, (6) evaporation and drying step, and (7) composition step. The obtained product thereof is a viscous composite glue composed of the aerogel, and the total content of the aerogel and an inorganic fiber is of 25-90 wt % after dried. Additionally, the obtained product can be used at a high temperature of more than 600° C., and has no phenomena of inorganic material decomposition and carcinogen production.

Claims

1. A method for producing a composite glue composed of a hydrophilic aerogel, an inorganic fiber, and an inorganic adhesive, comprising: mixing step: mixing a siloxane compound and a mixing solvent to form a mixing solution; hydrolysis step: adding an acid catalyst into the mixing solution to perform a hydrolysis reaction; condensation step: adding a basic catalyst into the mixing solution to perform a condensation reaction; wherein in the condensation reaction process, a hydrophobic dispersing solvent is added therein, and the mixing solution is mixed at a high speed to form an aerogel wet gel of a uniform structure; or wherein in the condensation reaction process, a hydrophobic dispersing solvent is added therein, and the mixing solution is mixed at a high speed to form an aerogel wet gel of a uniform structure, followed by crushing the aerogel wet gel under a large-amount hydrophobic solvent environment in order to crush the aerogel wet gel into particles of a particle size ranging from several hundreds of micrometers to several tenths of millimeters and being dispersed into the hydrophobic solvent; aging step: performing aging on the aerogel wet gel under a specific temperature in order to further stabilize the aerogel wet gel; high-temperature solvent replacement step: performing replacement of the hydrophobic dispensing solvent and a solvent in the aerogel wet gel under a condition of room pressure and high temperature until the aerogel wet gel becomes bluish transparent or completely transparent; evaporation and drying step: using high-temperature distillation to remove or using a filter to remove the hydrophobic solvent, followed by performing high-temperature drying on the aerogel wet gel in order to obtain hydrophilic aerogel particles having a high porosity and a high specific surface area; and composition step: using a mixing machine to mix the dried hydrophilic aerogel particles with an inorganic fiber with each other in order to form a uniformly dispersed inorganic mixture, followed by adding an inorganic adhesive solution into the inorganic mixture in order to allow the aerogel particles, the inorganic fiber and the inorganic adhesive solution to interact with each other to form a hydrophilic composite glue with a viscosity and composed of the aerogel and the inorganic fiber, following by adding a water, a thickener, a dispersant agent, or an aerogel powder to adjust the viscosity of the composite glue.

2. The method for producing a composite glue composed of a hydrophilic aerogel, an inorganic fiber, and an inorganic adhesive according to claim 1, wherein the siloxane compound comprises: a first hydrophilic alkoxysilane, a second hydrophilic alkoxysilane of a small amount, and a hydrophobic alkoxysilane of a small amount; the first hydrophilic alkoxysilane is selected from tetramethoxysilane (TMOS) or tetraethoxysilane (TEOS); the hydrophobic alkoxysilane is selected from methyltrimethoxysilane (MTMS) or methyltriethoxysilane (MTES); the second hydrophilic alkoxysilane is R-alkoxysilane, wherein R— refers to a hydrophilic functional group and comprises: —COOH, —NH.sub.2, —NH—, —OH, —CONH— or —COH—COH; and a carbon number of the hydrophilic functional group is from C1 to C8.

3. The method for producing a composite glue composed of a hydrophilic aerogel, an inorganic fiber, and an inorganic adhesive according to claim 1, wherein the mixing solvent comprises a first component and a second component; the first component comprises one or a plurality of compositions selected from a group consisting of the following: water, alcohols and alkanes; the second component comprises one or a plurality of compositions selected from a group consisting of the following: an emulsifier and a surfactant.

4. The method for producing a composite glue composed of a hydrophilic aerogel, an inorganic fiber, and an inorganic adhesive according to claim 1, wherein the hydrophobic dispensing solvent refers to C2 to C4 alcohols, C6 to C12 aromatics, C5 to C9 alkanes, or C7 to C12 aromatic alcohols; the alcohols refer to ethanol; the alkanes refer to hexane, cyclohexane or pentane; the aromatics refer to benzene or toluene; the aromatic alcohols refer to benzyl alcohol or phenethyl alcohol.

5. The method for producing a composite glue composed of a hydrophilic aerogel, an inorganic fiber, and an inorganic adhesive according to claim 1, wherein the solvent replacement step is performed at a temperature between 50 to 160° C. and under room pressure.

6. The method for producing a composite glue composed of a hydrophilic aerogel, an inorganic fiber, and an inorganic adhesive according to claim 1, wherein in the evaporation and drying step, the high-temperature distillation refers to a quick drying under a condition of a temperature between 60 and 160° C. and room pressure; wherein the high-temperature drying refers to using a fluidized bed dryer, a constant temperature oven, a drum dryer, a mixing dryer, a spray dryer or a vacuum dryer at a temperature between 90 and 250° C. to perform drying.

7. The method for producing a composite glue composed of a hydrophilic aerogel, an inorganic fiber, and an inorganic adhesive according to claim 2, wherein a density, a particle size, a porosity and a pore size of the aerogel particles are controlled based on the following criterion: a content of the first hydrophilic alkoxysilane, a content of the second hydrophilic alkoxysilane, a content of the hydrophobic alkoxysilane, a content of the solvent, a viscosity of the solvent, a content of the acid catalyst, a content of the basic catalyst, a type or a content of the hydrophobic dispensing solvent, a type or a content of the hydrophobic solvent, a solvent replacement temperature, and a mixing speed.

8. The method for producing a composite glue composed of a hydrophilic aerogel, an inorganic fiber, and an inorganic adhesive according to claim 1, wherein the composition step is replaced by: using a mixing machine under a mixing force to mix the dried hydrophilic aerogel particles directly with an inorganic fiber to form a uniformly dispersed inorganic mixture, followed by adding an inorganic adhesive into the inorganic mixture in order to allow the aerogel particles, the inorganic fiber and the inorganic adhesive to interact with each other to form a viscous aerogel composite glue, following by adding a water, a thickener, a dispersant agent, or an aerogel powder to adjust a viscosity of the aerogel composite glue.

9. The method for producing a composite glue composed of a hydrophilic aerogel, an inorganic fiber, and an inorganic adhesive according to claim 8, wherein the inorganic adhesive is selected from: phosphate, silicate, sulfate, borate, or metal oxide; the phosphate refers to zirconium phosphate, phosphoric acid-cooper oxide; the silicate refers to aluminum silicate or sodium silicate; the metal oxide refers to an oxide containing a copper, aluminum, zirconium, yttrium or lanthanide element.

10. The method for producing a composite glue composed of a hydrophilic aerogel, an inorganic fiber, and an inorganic adhesive according to claim 1, wherein a content of the aerogel is 15-40 v/v % of the composite glue, a content of the inorganic fiber is 10-35 v/v %, a content of the inorganic adhesive solution is 25-75 v/v %, and a total content of the aerogel and the inorganic fiber in an aerogel heat insulation board obtained from the composite glue after drying is 25-90 wt %.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG. 1 is a flowchart of the steps of the method for producing a hydrophilic aerogel composite glue according to an embodiment of the present invention;

[0034] FIG. 2 is a photo image showing the outer appearance of the hydrophilic aerogel particles produced based on the method of the present invention;

[0035] FIG. 3 is a photo image showing the outer appearance of the hydrophilic aerogel particles produced based on the method of the present invention;

[0036] FIG. 4 is a scanning electronic microscope photo image showing the hydrophilic aerogel particles produced based on the method of the present invention;

[0037] FIG. 5 is a photo image showing a high-temperature and heat-insulating aerogel brick of the dimension of 10.5 cm×10.5 cm×9.5 cm; and

[0038] FIG. 6 is a temperature change graph of a rear side of a high-temperature and heat-insulating aerogel brick of a thickness of 3 cm being heated for 3 hours under the temperature condition of 1200° C.; wherein the ratio refers to the volume ratio.

DETAILED DESCRIPTION OF THE INVENTION

[0039] Please refer to FIG. 1, showing a method for producing a composite glue composed of a hydrophilic aerogel, an inorganic fiber, and an inorganic adhesive of the present invention, comprising the following steps: mixing step (S1), hydrolysis step (S2), condensation and dispersion step (S3) or condensation and crushing step (S3′), aging step (S4), high-temperature solvent replacement step (S5), evaporation and drying step (S6), and composition step (S7). Accordingly, it is able to be applied to the production of an aerogel heat insulation brick with high temperature resistance.

[0040] Mixing step (S1): A siloxane compound and a mixing solvent are mixed. The siloxane compound comprises one or a plurality of compounds selected from a group consisting of the following: hydrophilic alkoxysilane, such as tetramethoxysilane (TMOS) or tetraethoxysilane (TEOS), and a small amount of hydrophobic alkoxysilane, such as methyltrimethoxysilane (MTMS) or methyltriethoxysilane (MTES); the above hydrophobic molecules, in the present content, are mainly to provide some hydrophobic characteristic for the aerogel in order to increase the structural stability of the aerogel structure. In addition, another hydrophilic alkoxysilane of an extremely small amount can be further added: R-alkoxysilane, and it is mainly to perform the aerogel microstructure modification and control the functional group content; wherein R— refers to a hydrophilic functional group, comprising: —COOH, —NH.sub.2, —NH—, —OH, —CONH— or —COH—COH; and a carbon number of the hydrophilic functional group is from C1 to C8. For calculation based on the total content of the mixing solution, the total content of the siloxane compound is 3.0 mol % to 60.0 mol %; wherein the hydrophobic alkoxysilane content is 0.05 mol % to 6.0 mol %, and the solvent content is 97.0 mol % to 40.0 mol %.

[0041] The solvent used in the mixing step (S1) can be water, conditioned water, deionized water, secondary water, C1 to C8 alcohols, C1 to C8 alkanes, polymer emulsifier or surfactant. To be more specific, the mixing agent is water, conditioned water, deionized water, ethanol, toluene, n-hexane, cyclohexane, polyvinyl alcohol, or hexadecyl trimethyl ammonium chloride.

[0042] Hydrolysis step (S2): An acid catalyst is added into the mixing solution to perform a hydrolysis reaction. The ratio between the total content of siloxane compound and the acid catalyst is 1:0.5 to 1:0.0001. In addition, when it contains certain specific R-alkoxysilane, it is not necessary to add the acid catalyst, but water can be used directly for the hydrolysis. Furthermore, when the ratio between the total content of the siloxane compound and the acid catalyst is 1:0.0001, the hydrolysis reaction time requires 360 minutes. When the ratio between the total content of the siloxane compound and the acid catalyst is 1:0.5, the hydrolysis reaction time requires 5 minutes. Therefore, it can be understood that the hydrolysis time is reduced along with the increase of the acid catalyst content.

[0043] Condensation and dispersion step (S3) or condensation and crushing step (S3′): A basic catalyst is added into the mixing solution to perform a condensation reaction. The mole ratio between the acid catalyst and basic catalyst is from 1:1 to 1:4. In the mixing solution, increase of the basic catalyst content is able to significantly reduce the condensation reaction time (i.e. The gelation time). When the mole ratio of the acid catalyst and basic catalyst is 1:1, gelation time is approximately 1,200 minutes. When the mole ratio of the acid catalyst and basic catalyst is 1:3, gelation time is reduced to approximately 3-5 minutes. Therefore, the basic catalyst content can be adjusted to adjust the gelation time.

[0044] Before the condensation reaction is near completion, the mixing solution forms a solution-like sol. In the condensation and dispersion step (S3), when the mixing solution is controlled to be under the solution-like sol condition, add a large amount of hydrophobic dispersing solvent of incompatible system is added, and fast mixing at a rotational speed between 100 rpm and 500 rpm is performed, in order to allow the mixing solution to be under the acting force of the mixing solvent effect of the dispersing solvent, and to allow the hydration force of the water molecules in the mixing solution to be suppressed, following which through gelation, it forms a hydrophilic aerogel wet gel. The volume ratio of the mixing solvent and the hydrophobic dispersing solvent is between 1:0.05 and 1:0.5. As the content of the hydrophobic dispersing solvent is higher, the contraction ratio of the aerogel particles subsequently produced is lower, the macroscopic phase separation behavior is more severe and it is of an opaque appearance; however, its structural porosity is relatively higher and the density is lower. In the condensation and crushing step (S3′), under the condition of large amount of hydrophobic solvent, crushing is further performed on the hydrophilic aerogel wet gel in order to crush the wet gel into particles of a particle size ranging from several hundreds of micrometers to several tenths of millimeters and being dispersed in the hydrophobic solvent.

[0045] In the condensation and dispersion step (S3) or the condensation and crushing step (S3′), the hydrophobic dispersing solvent can be C2 to C4 alcohols, C6 to C12 aromatics, C5 to C9 alkanes, or C7 to C12 aromatic alcohols. To be more specific, the hydrophobic dispersing solvent is ethanol, hexane, cyclohexane, pentane, benzene, toluene, benzyl alcohol or phenethyl alcohol.

[0046] Aging step (S4): Aging is performed when the hydrophilic aerogel wet gel structure is under a specific temperature (such as between 35 and 80° C., and preferably between 40 and 50° C.) in order to stabilize the hydrophilic aerogel wet gel structure.

[0047] High-temperature solvent replacement step (S5): The condition of room pressure and high temperature (such as between 50 and 160° C.) is used to perform solvent replacement on the wet gel. In the high-temperature solvent replacement step (S5), the miscibility between the hydrophilic and hydrophobic solvents is utilized in order to achieve the solvent mixing and azeotropic effect between the water molecules in the wet gel or other hydrophilic molecules and large-amount of hydrophobic solvent, thereby replacing the solvent in the wet gel swiftly until it is bluish transparent or completely transparent. Therefore, hydrophilic aerogel particles of low density and high porosity can be produced subsequently.

[0048] Evaporation and drying step (S6): After high-temperature distillation is used to remove the aforementioned remaining hydrophobic solvent or filter is used to remove the aforementioned remaining hydrophobic solvent, the wet gel is dried quickly under the condition of temperature between 60 and 160° C. and under room pressure, in order to obtain hydrophilic aerogel particles of a high density. Subsequently, a fluidized bed dryer, a constant temperature oven, a drum dryer, a mixing dryer, a spray dryer or a vacuum dryer at a temperature between 90 and 250° C. is used to dry the aerogel particles in order obtain dry hydrophilic aerogel particles.

[0049] Accordingly, hydrophilic aerogel particles of a particle size ranging from several hundreds of micrometers to several tenths of millimeters can be produced. In addition, through the technique of the present invention, it is able to produce hydrophilic functional group modified aerogel particles, and they can be mixed with the material of, such as, cement, cement paint, adhesive, or paint in order to be applied onto various types of fireproof and heat insulation products, thereby enhancing the application property of the aerogel particles. Particularly, the aerogel particles produced can be applied to high-temperature resistant aerogel heat insulation boards or bricks production and application.

[0050] Composition step (S7): Furthermore, the transparent aerogel particles can be directly mixed with an inorganic fiber in a mixing machine under a mixing force to mix with each other in order to form a uniformly dispersed inorganic mixture, followed by adding an inorganic adhesive therein in order to allow the aerogel particles, the inorganic fiber and the inorganic adhesive to interact with each other to form a viscous aerogel composite glue, following by adding water, a thickener, a dispersant agent, or an aerogel powder to adjust a viscosity of the aerogel composite glue in order to obtain the aerogel composite glue.

[0051] The inorganic adhesive used in the composition step (S7) comprises one or a plurality of compounds selected from a group consisting of the following: phosphate, silicate, sulfate, borate, metal oxide. To be more specific, the phosphate refers to, such as, zirconium phosphate or phosphoric acid-cooper oxide. The silicate refers to, such as, aluminum silicate or sodium silicate. The metal oxide refers to a metal oxide containing a copper, aluminum, zirconium, yttrium or lanthanide element.

[0052] Please refer to FIG. 2 and FIG. 3, showing the outer dimensions of the hydrophilic aerogel particles observed by using a conventional camera. In FIG. 2, it shows that the micron-sized hydrophilic aerogel particles have a dimension of approximately 50 micrometers to 200 micrometers. In FIG. 3, it shows that the millimetre-sized hydrophilic aerogel particles have a particle size of approximately 3 millimeters to 20 millimeters.

[0053] Please refer to FIG. 4. A scanning electronic microscope is used to observe the microstructure of the hydrophilic aerogel particles, and their surfaces and the internal contain a great quantity of pores.

[0054] Please refer to FIG. 5, showing the outer appearance of a high-temperature and heat-insulating aerogel brick of the dimension of 10.5 cm×10.5 cm×9.5 cm produced. As shown in the photo image, its weight is 277.1 g. After calculation, it can be obtained that the density of the high-temperature and heat-insulating aerogel brick is 0.265 g/cm.sup.3, such that it has an excellent light-weight effect.

[0055] Please refer to FIG. 6, in which the comparison on the temperatures of the rear side of a high-temperature and heat-insulating aerogel brick of a thickness of 3 cm being heated for 3 hours under the temperature condition of 1200° C. is performed. From the comparison result, it indicates that when the room temperature is 25° C., the rear side temperature of the high-temperature and heat-insulating aerogel brick after being heated for 3 hours under 1200° C. is approximately 175° C., demonstrating that the product produced from the method according to this embodiment of the present invention has excellent properties of high temperature resistance and heat insulation.

[0056] In view of the descriptions of the aforementioned embodiments, the manufacturing, application and technical effects of the present invention can be sufficiently understood. However, it shall be noted that the aforementioned embodiments refer to the preferred embodiments of the present invention only such that they shall not be used to limit the scope of the present invention, i.e. All simple equivalent changes and modifications made based on the claims and the content of the description of the present invention shall be considered to be within the scope of the present invention.