WO2015010651A1

WO2015010651A1 - Building thermal insulation aerogel material and method of preparation

Info

Publication number: WO2015010651A1
Application number: PCT/CN2014/083024
Authority: WO
Inventors: 陈庆; 曾军堂
Original assignee: 成都新柯力化工科技有限公司
Priority date: 2013-07-26
Filing date: 2014-07-25
Publication date: 2015-01-29
Also published as: CN103408279A; CN104086150B; CN104086150A

Abstract

A building thermal insulation aerogel material and method of preparation. The starting material composition of the building thermal insulation aerogel is: 70-90 parts of silica sol, 10-28 parts of polyvinyl alcohol hot-melt adhesive, and 1-2 parts of hydrophobic agent. The preparation method uses silica sol as a main body, a polyvinyl alcohol hot-melt adhesive as a thermoplastic hot-melt adhesive body, and an inert gas as a support body; by means of the momentary elevated temperature and pressure of a continuous kneading screw reactor, the gel is extruded in the extruder barrel; the liquid components of the wet gel inflate due to instantaneous evaporation at the die opening; at the same time as the evaporation of the liquid components, an inert gas serves as the aerogel support body, ensuring that the complete framework structure of the aerogel does not collapse, completing the transformation from wet gel to aerogel. The aerogel has good strength, high porosity, and excellent insulation properties, and can be applied in the fields of building insulation sheets, insulation mortars, and insulation coatings.

Description

Building thermal insulation aerogel material and preparation method thereof

Technical field

The invention relates to the field of building thermal insulation materials, in particular to a building thermal insulation aerogel material and a preparation method thereof. Background technique

Today's world energy problem has become a major problem affecting development. As building energy consumption accounts for 30%~40% of the total energy consumption, building energy conservation is of great significance. Building insulation materials are an important measure for building energy conservation. At present, the most widely used form of insulation in the domestic market is external wall insulation. Due to the low thermal conductivity of organic insulation materials and good thermal insulation properties, they are widely used in building energy conservation. However, organic insulation materials have various drawbacks, such as the use of petroleum resources in raw materials, poor environmental protection, flammability, poor weatherability, and aging. Especially with the further promotion and application, the flammable defects of organic insulation materials are gradually exposed, which seriously threatens people's safety. Therefore, low thermal conductivity, high temperature non-combustible thermal insulation materials have become the development trend of building insulation and energy conservation.

Aerogel has a three-dimensional nanoporous structure, high porosity, large specific surface area and low thermal conductivity. It is the lowest thermal conductivity material in the world. It has excellent thermal insulation properties and fire resistance. It is an ideal substitute for traditional thermal insulation materials. It has a good application prospect and is highly concerned by both domestic and foreign. However, aerogels have been used in high-end fields such as aerospace, military, and pharmaceutical carriers because of their complicated preparation process and high production cost. It is faced with bottlenecks of high cost and low production in the field of building insulation and energy conservation. At present, the preparation of aerogel is usually carried out by a sol-gel process and a supercritical drying process. In the sol-gel process, by controlling the hydrolysis and polycondensation reaction conditions of the solution, a nano-atomic group of porous channels is formed in the solution, nanometer. The atomic groups are bonded to each other to form a gel, and the solid skeleton of the gel is filled with a liquid reagent remaining after the chemical reaction. In order to prevent micropore collapse during gel drying, it is usually treated by a supercritical drying process. The supercritical drying process can better maintain the porous network structure of the gel, but the conditions required for supercritical drying are very harsh, the preparation cycle takes a long time, the equipment requirements are high, the energy consumption is large, and continuous production cannot be achieved, resulting in aerogel The price of the product is extremely expensive. Although aerogels have good thermal insulation, thermal insulation, and fire resistance, the aerogels produced by the prior art are too expensive to be used in large-scale applications in building insulation. In order to break through the cost limitation of aerogel in the field of building thermal insulation, in recent years, the preparation of aerogels by non-supercritical drying has emerged.

The preparation and method of a silica aerogel composite material is disclosed in Chinese Patent Publication No. CN102557577A. The method uses a fiber as a reinforcing material, and obtains a silica aerogel by washing and sub-step drying at different temperatures, which requires not only a large amount of solvent but also a long time.

Chinese Patent Publication No. CN201310000374 discloses a low-cost preparation method of silica aerogel. The aerogel is prepared by using a surfactant to eliminate or convert the liquid/air interface into a small adhesion interface, so that the integrity of the network structure is destroyed within a limited range during the drying process, but with the coagulation The increase in the rate of the glue channel and the size of a large number of fine pores are on the order of nanometers, the capillary effect causes difficulty in drying, and it is difficult to obtain a high-porosity aerogel. So far, the preparation of aerogel technology by non-supercritical drying method has focused on improving the support strength of the gel structure network structure and reducing the influence of capillary adsorption force. It has not yet formed a relatively mature technical solution, and cannot completely guarantee the gas condensation. The aerogel material is dried on the premise that the gel network structure is not destroyed. To this end, the present invention proposes a technical solution for achieving a key indicator of continuous drying, high strength and low cost of aerogel. The aerogel material can replace the existing organic thermal insulation board in the external thermal insulation system, replace the inorganic vitrified microbeads in the thermal insulation mortar, and mix the coating to make the coating have the thermal insulation effect, and achieve the aerogel material in the wall Wide application in the field of insulation.

Summary of the invention

The invention aims at the defects of low aerogel strength, complicated preparation process and high cost, and provides a building thermal insulation aerogel material which can be used in the field of building energy conservation. The building thermal insulation aerogel is composed of a silica sol and a polyvinyl alcohol hot melt adhesive.

A further object of the present invention is to provide a method for preparing a building thermal insulation aerogel material, which is mainly composed of a silica sol, a polyvinyl alcohol hot melt adhesive as a thermoplastic melt colloid, and an inert gas as a support. Through the instantaneous high temperature and high pressure of the continuous kneading screw reactor, the gel is squeezed in the extrusion cylinder, and the liquid component in the wet gel expands due to the instantaneous evaporation of the die, while the liquid component is volatilized The inert gas acts as an aerogel support, ensuring that the complete skeleton structure of the aerogel does not collapse, completing the transition of the wet gel to the aerogel.

The invention relates to a building thermal insulation aerogel, which provides the following solutions:

1. A building thermal insulation aerogel material according to the invention, characterized in that the raw material composition (parts by weight) is: 70-90 parts of silica sol, 10-28 parts of polyvinyl alcohol hot melt adhesive, hydrophobic agent 1- 2 servings.

2. The above silica sol is a sol obtained by hydrolysis of methyl orthosilicate or ethyl orthosilicate, and has a solid content of 50-60%.

3. The above polyvinyl alcohol hot melt adhesive is a fine powder obtained by mechanically chemically grinding polyvinyl alcohol, glycerin, polyethylene glycol-2000, and a crosslinking agent, wherein the fineness of polyvinyl alcohol is 200. 17-88 having a degree of alcoholysis of 87% to 89%, and the crosslinking agent is at least one of adipic acid, succinic acid, maleic anhydride, and borax.

4. The hydrophobic agent described above is at least one of isopropoxy III (dioctyl pyrophosphate) titanium, ethylene glycol diester (dioctyl pyrophosphate) titanium, and distearyl ethylene titanium.

5. The method for preparing a building thermal insulation aerogel material of the present invention comprises the following steps:

(1) preparing a silica sol;

(2) preparing a polyvinyl alcohol hot melt adhesive;

(3) preparing a aging wet gel;

(4) Preparation of building thermal insulation aerogel.

6. The silica sol prepared according to the above preparation method, wherein 50-60 parts by weight of methyl orthosilicate or ethyl orthosilicate, 20-30 parts by weight of an alcohol solvent is added to the vessel and stirred for 5-10. Minutes, add 5-10 parts by weight of methyl triethoxy Add 10-15 parts of water, 榥抨3-5 parts of potassium, add hydrochloric acid to adjust the pH of the bath to 3-5, set the heating temperature of the heater oil to 80-100 °C and continue to stir and hydrolyze for 30-60 minutes.

7. The polyvinyl alcohol hot melt adhesive prepared according to the above preparation method is 80-90 parts of polyvinyl alcohol, 5-10 parts of glycerin, 2-8 parts of polyethylene glycol-2000, 1-3 The cross-linking agent is obtained by mechanical chemical polishing, and the grinder adopts a vortex grinder; the vortex flow is used to fully exfoliate the poly(3) alcohol and the modified jingle, and the turntable speed is adjusted by the turntable reactance speed controller to iOOO-1200r /ffiin, is a continuous discharge of polyvinyl alcohol to a certain particle size and reaction, with continuous and efficient production.

8. The prepared wet gel according to the above preparation method, wherein 10-28 parts by weight of polyvinyl alcohol hot melt adhesive, 1-2 parts of hydrophobic agent is added to 70-90 parts of silica sol solution, and triethanolamine is added. Adjust the pH value to 8~10, stir evenly. The polyvinyl alcohol hot melt adhesive has thermoplasticity at high temperature, and has solubility in water solvent. It can be uniformly dispersed in the wet gel and then placed in a closed aging tank. An aging gel is obtained in an hour.

9. The building thermal insulation aerogel prepared according to the above preparation method, the temperature of the continuous kneading screw reactor cylinder is raised to 100-120 ° C, the circulating cooling water valve is opened, and the temperature of the screw press is maintained at 100-120 °C, the aging gel is added to the continuous kneading screw reactor, the wet gel is continuously added to the screw reactor, and the inert gas source is pumped at the same time. The wet gel is stretched in the polyvinyl alcohol hot melt adhesive. The lower into the instantaneous molten state, the wet gel entering the die expands due to the instantaneous evaporation of the liquid component in the die, and the inert gas acts as an aerogel support while the liquid component is volatilized, completing the wet gel to the gas. The transformation of the gel is cut by a pelletizer to form a uniform granular aerogel.

10. The inert gas source described above is sodium hydrogencarbonate which is pumped when the wet gel enters the die and continuously releases the inert gas under transient high pressure and high temperature conditions to ensure that the complete skeleton structure of the aerogel does not collapse.

11. The continuous kneading screw reactor described above is a tapered single screw machine, and the screw diameter is reduced from Φ 60 cm to Φ 40 mm from the feeding to the discharging, and the screw length to diameter ratio is 5:1-8:1. The melt material can be rapidly compressed, so that the wetting agent such as water can be quickly evaporated from the structure, so that the wet gel forms numerous microporous structures, and has a continuous high-efficiency devolatilization function.

The invention adopts a thermoplastic melt colloid as a molten state as a support, and uses an inert gas as a support to realize a continuous and efficient production of a building thermal insulating aerogel material by a kneading screw reactor, and the outstanding features are as follows:

1. Good strength. The thermoplastic melt used in the present invention not only assists in the rapid drying of the aerogel in a molten state, but also forms a continuous network structure after the aerogel is formed, thereby achieving toughening of the aerogel material.

2. High porosity and excellent thermal insulation performance. The invention adopts an inert gas source, and continuously supplies the gas source during the rapid drainage process of the aerogel, maintaining a complete aerogel nano-frame structure, the thermal conductivity is less than 0.02 W / (m K), and the porosity can be greater than 96%, specific surface area greater than 800 m2 / g, with excellent thermal insulation properties.

3. The production process is simple and efficient. The continuous kneading screw reactor of the invention causes the wet gel to instantaneously dry and expand, and the inert gas acts as an aerogel support while the liquid component is volatilized, ensuring that the complete skeleton structure of the aerogel does not collapse, completing The transition from wet gel to aerogel avoids the complicated process of supercritical drying and avoids the collapse of aerogel pores during atmospheric drying. The production process is simple, the operation is stable, and continuous mass production is possible.

4, a wide range of applications. The invention has the characteristics of continuous large-scale production, effectively reduces the cost of aerogel, and promotes wide application in the field of building energy conservation, and can be applied to the fields of thermal insulation board, thermal insulation mortar, thermal insulation coating and the like.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be further described in detail by way of specific embodiments, but it should not be construed that the scope of the invention is limited to the following examples. Various substitutions and modifications may be made without departing from the spirit and scope of the invention. Example 1

1) 60 parts by weight of methyl orthosilicate, 20 parts by weight of ethylene glycol was added to the vessel and stirred for 10 minutes, 10 parts by weight of methyltriethoxysilane was added, 10 parts of water was added, and the mixture was stirred for 3 minutes. The pH of the hydrochloric acid adjusting solution is set to 5, and the temperature of the oil temperature of the container is set to 100 ° C, and the hydrolysis is continued for 60 minutes to obtain a silica sol;

2) 80 parts of polyvinyl alcohol 1788, 10 parts of glycerin, 2 parts of polyethylene glycol -2000, 1 part of borax are modified by grinding to obtain a polyvinyl alcohol hot melt adhesive powder;

3) Add 10 parts by weight of polyvinyl alcohol hot melt adhesive powder, 2 parts of ethylene diester (dioctyl pyrophosphate) titanium to 88 parts of silica sol solution, add triethanolamine to adjust the pH value to 10, stir evenly, The polyvinyl alcohol hot melt adhesive powder is uniformly dispersed in the wet gel, and then aged in a closed aging tank for 24 hours to obtain an aged wet gel;

4) Increase the temperature of the JS-60 continuous kneading screw reactor cylinder to 120 °C, open the circulating cooling water valve, control the screw press temperature to maintain 120 °C, and add the aged wet gel to the continuous kneading. The screw reactor, the wet gel is continuously added to the screw reactor, and the inert gas source is pumped at the same time. The wet gel becomes a transient molten state under the stretching of the polyvinyl alcohol hot melt adhesive, and the wet gel entering the die is liquid. The component expands due to the instantaneous evaporation of the die. The inert gas acts as an aerogel support while the liquid component is volatilized, and the transformation of the wet gel to the aerogel is completed, and the pellet is cut by a pelletizer to form a uniform granular gas. gel.

Pass each test

^ lOMPa

2 W/ (m · Κ). The thermal conductivity of the cement board is reduced from 0. 8 W / (m · Κ) to 0.2 W / (m · Κ), after the aerogel is added to the cement board at a volume ratio of 30%.

Example 2

1) 55 parts by weight of ethyl orthosilicate, 20 parts by weight of ethylene glycol was added to the vessel and stirred for 10 minutes, 10 parts by weight of methyltriethoxysilane was added, 15 parts of water was added, and the mixture was stirred for 3 minutes. The pH of the hydrochloric acid-adjusting solution is set to 5, and the temperature of the container oil is set to 100 ° C, and the hydrolysis is continued for 50 minutes to obtain a silica sol;

2) 90 parts of polyvinyl alcohol 1788, 5 glycerol, 2 parts of polyethylene glycol - 2000, 3 parts of succinic acid are modified by grinding to obtain a polyvinyl alcohol hot melt adhesive powder;

3) Add 25 parts of polyvinyl alcohol hot melt adhesive powder, 2 parts of isopropoxy tris(dioctyl pyrophosphate) titanium to 73 parts of silica sol solution, add triethanolamine to adjust the pH value to 10, stir evenly, The polyvinyl alcohol hot melt adhesive powder is uniformly dispersed in the wet gel, and then aged in a closed aging tank for 24 hours to obtain an aged wet gel;

4) Increase the temperature of the JS-60 continuous kneading screw reactor cylinder to 120 °C, open the circulating cooling water valve, control the screw press temperature to maintain 120 °C, and add the aged wet gel to the continuous kneading. The screw reactor, the wet gel is continuously added to the screw reactor, and the inert gas source is pumped at the same time. The wet gel becomes a transient molten state under the stretching of the polyvinyl alcohol hot melt adhesive, and the wet gel entering the die is liquid. The component expands due to the instantaneous evaporation of the die. The inert gas acts as an aerogel support while the liquid component is volatilized, and the transformation of the wet gel to the aerogel is completed, and the pellet is cut by a pelletizer to form a uniform granular gas. Gel, aerogel is spherical with a diameter of 3-5 mm.

Pass the test performance indicators as follows:

The aerogel is 0.5 kg and 42. 5R cement 350kg, ash calcium powder 125kg, 40-70 mesh sand 500kg, resin rubber powder 15kg, mixed preparation of thermal insulation mortar, the product fully meets the technical requirements of national standard GB/T26000-2010 :

Test item performance index

Dry density (Kg / m ³ ) 200

Thermal conductivity (W / m. k) 0. 05

Compressive strength (MPa) 1. 0

Fire rating (according to GB5464 standard) Class A Example 3

1) 50 parts by weight of ethyl orthosilicate, 25 parts by weight of ethylene glycol was added to the vessel and stirred for 5 minutes, 5 parts by weight of methyltriethoxysilane was added, 10 parts of water was added, and the mixture was stirred for 3 minutes. The pH of the hydrochloric acid adjusting solution is set to 5, and the temperature of the oil temperature of the container is set to 100 ° C, and the hydrolysis is continued for 30 minutes to obtain a silica sol;

2) 85 parts of polyvinyl alcohol 1788, 8 glycerin, 4 parts of polyethylene glycol - 2000, 3 parts of adipic acid are modified by grinding to obtain a polyvinyl alcohol hot melt adhesive powder;

3) Add 20 parts of polyvinyl alcohol hot melt adhesive powder, 2 parts of isopropoxy tris(dioctyl pyrophosphate) titanium to 78 parts of silica sol solution, add triethanolamine to adjust the pH to 9, stir evenly, The polyvinyl alcohol hot melt adhesive powder is uniformly dispersed in the wet gel, and then aged in a closed aging tank for 24 hours to obtain an aged wet gel;

Pass the test performance indicators as follows:

The heat transfer coefficient of the coating is only 0. 03W / the heat transfer coefficient of the coating is only 0. 03W / the heat transfer coefficient of the coating is 0. 03W / m · K.

Claims

Claim

A building thermal insulation aerogel material characterized in that the raw material composition (parts by weight) is:

Silica sol 70-90 parts

Polyvinyl alcohol hot silicone gel 10-28 parts

Hydrophobic agent 1-2 parts

Wherein, the silica sol is a sol obtained by hydrolysis of methyl orthosilicate or ethyl orthosilicate, and has a solid content of 50-60%;

The polyvinyl alcohol hot melt adhesive is a fine powder obtained by mechanical mechanical polishing of polyvinyl alcohol, glycerin, polyethylene glycol-2000, and a crosslinking agent, wherein the polyvinyl alcohol has a fineness of 200 mesh. , the alcoholysis degree is 87% to 89% of 17-88, the crosslinking agent is at least one of adipic acid, succinic acid, maleic anhydride, and borax;

The hydrophobic agent is at least one of isopropoxy III (dioctyl pyrophosphate) titanium, ethylene glycol diester (dioctyl pyrophosphate) titanium, and distearyl ethylene titanium.

2. A method of making an insulating thermal aerogel material according to claim 1, characterized in that it is prepared as follows:

(1) preparing a silica sol;

(2) Preparation of polyvinyl alcohol hot melt adhesive:

(3) preparing a aging wet gel;

(4) Preparation of building thermal insulation aerogels.

3. A method of preparing a building thermal insulating aerogel material according to claim 1, characterized in that the silica sol prepared according to claim 2 is 50-60 parts by weight of methyl orthosilicate or Ethyl orthosilicate, 20-30 parts by weight of an alcohol solvent is added to the vessel and stirred for 5-L0 minutes, 5-10 parts by weight of methyltriethoxysilane is added, 10-15 parts of water is added, and the mixture is stirred for 3-5 minutes. Add hydrochloric acid to adjust the pH of the solution to 3-5, set the container oil temperature to a temperature of 80-100 ° C and continue to stir and hydrolyze for 30-60 minutes.

4. A method of preparing a building thermal insulating aerogel material according to claim 1, characterized in that the polyvinyl alcohol hot melt adhesive according to claim 2 is obtained by using 80-90 parts of polyvinyl alcohol, 5 - 10 parts of glycerol, 2-8 parts of polyethylene glycol-2000, 1-3 parts of crosslinking agent are obtained by mechanical chemical polishing.

5. A method of preparing a building thermal insulating aerogel material according to claim 1, characterized in that the prepared aged wet gel according to claim 2 is 10-28 parts by weight of polyvinyl alcohol hot melt adhesive. 1-2 parts of hydrophobic agent is added to 70-90 parts of silica sol solution, triethanolamine is added to adjust pH value of 8~10, and the mixture is evenly stirred. The polyvinyl alcohol hot melt adhesive has thermoplasticity at high temperature and has water solvent. Solubility, can be uniformly dispersed in the wet gel, and then aged in a closed aging tank for 24 hours to obtain an aged wet gel.

6. A method of making a building thermal insulation aerogel material according to claim 1 characterized by claim 2 The preparation of building thermal insulation aerogel is to increase the temperature of the continuous kneading screw reactor cylinder to 100-120 ° C, open the circulating cooling water valve, and control the screw press temperature to maintain 100-120 ° C, The aging gel is added to the continuous kneading screw reactor. The wet gel is continuously added to the screw reactor, and the inert gas source is pumped at the same time. The wet gel becomes instantaneously molten under the stretching of the polyvinyl alcohol hot melt adhesive. The wet gel entering the die expands due to the instantaneous evaporation of the liquid component, and the inert gas acts as an aerogel support while the liquid component is volatilized, completing the transition of the wet gel to the aerogel. The granulator cuts to form a uniform granular aerogel.

7. The building thermal insulation aerogel material according to claim 6, wherein the inert gas source in the preparation method is sodium hydrogencarbonate, which is pumped when the wet gel enters the die, at a momentary high pressure, The inert gas is continuously released under high temperature conditions, ensuring that the complete skeleton structure of the aerogel does not collapse.

8. The building thermal insulation aerogel material according to claim 6, wherein the continuous kneading screw reactor is a tapered single screw machine, and the screw diameter is from feeding to discharging. Reduced from Φ 60cm to Φ 40mm, the screw length to diameter ratio is 5: 1-8: 1.