阅读说明：本技术 一种纳米保温材料及其制备方法和应用 (Nano thermal insulation material and preparation method and application thereof ) 是由 纪冠丞 张磊 李季 于 2021-07-21 设计创作，主要内容包括：一种纳米保温材料及其制备方法和应用,本发明涉及保温材料及其制备方法和应用。本发明是要解决现有的保温夹层材料导热系数高、工艺复杂、阻燃绝缘性差、成品收缩率大的技术问题。方法：将按重量份数比称取后的主要填料、辅助填料和粘结剂使用分散机分散,得到混合料；向混合料中加入短切纤维,室温下使用分散机搅拌,得到纳米保温材料；将纳米保温材料注入到热水器内胆与特制的一体成型模具之间的夹层中,经加热,蒸养,最后开模,得到热水器纳米保温材料夹层。本发明用于保温材料领域。(The invention discloses a nano heat-insulating material and a preparation method and application thereof, and relates to a heat-insulating material and a preparation method and application thereof. The invention aims to solve the technical problems of high heat conductivity coefficient, complex process, poor flame-retardant insulation property and large shrinkage rate of finished products of the existing heat-insulating interlayer material. The method comprises the following steps: dispersing the main filler, the auxiliary filler and the binder which are weighed according to the weight part ratio by using a dispersion machine to obtain a mixture; adding chopped fibers into the mixture, and stirring the mixture at room temperature by using a dispersion machine to obtain a nano heat-insulating material; and (3) injecting the nano heat-insulating material into an interlayer between the inner container of the water heater and a specially-made integral forming die, heating, steam curing, and finally opening the die to obtain the interlayer of the nano heat-insulating material of the water heater. The invention is used in the field of heat insulation materials.)

1. A nanometer thermal insulation material is characterized in that the nanometer thermal insulation material is prepared by 20-40 parts of main filler, 10-20 parts of auxiliary filler, 100-150 parts of binder and 5-15 parts of chopped fiber according to the weight percentage ratio; wherein the main filler is silicon dioxide aerogel powder and/or fumed silica; the auxiliary filler is one or the combination of a plurality of carbon black, silicon carbide, potassium hexatitanate whisker, titanium dioxide, gas phase alumina and hollow glass microballoon.

2. The nano heat-insulating material as claimed in claim 1, wherein the binder is one or more of sodium silicate, silica sol, acrylic resin, epoxy resin, amino resin and organosilicon modified styrene-acrylic emulsion.

3. The nano-insulation material as claimed in claim 1 or 2, wherein the chopped fiber is one or more of high silica fiber, glass fiber, rock wool fiber, alumina silicate fiber and mullite fiber.

4. The method for preparing the nano heat-insulating material as claimed in claim 1, characterized in that the method is carried out according to the following steps:

weighing 20-40 parts of main filler, 10-20 parts of auxiliary filler, 100-150 parts of binder and 5-15 parts of chopped fiber according to the weight ratio; wherein the main filler is silicon dioxide aerogel powder and/or fumed silica; the auxiliary material is one or the combination of a plurality of carbon black, silicon carbide, potassium hexatitanate whisker, titanium dioxide, gas phase alumina and hollow glass microballoon;

secondly, putting the main filler, the auxiliary filler and the binder in the step one into a dispersion machine, and dispersing for 1-12 hours at room temperature to obtain a mixture;

and thirdly, adding the chopped fibers in the step one into the mixture in the step two, and continuously dispersing for 0.5-6h at room temperature to obtain the nano heat-insulating material.

5. The method for preparing a nanometer thermal insulation material according to claim 4, characterized in that the binder in the step one is one or a combination of several of sodium silicate, silica sol, acrylic resin, epoxy resin, amino resin and organosilicon modified styrene-acrylic emulsion.

6. The method for preparing nano heat insulation material according to claim 4 or 5, characterized in that the chopped fiber in the first step is one or a combination of several of high silica fiber, glass fiber, rock wool fiber, alumina silicate fiber and mullite fiber.

7. The method for preparing the nano heat-insulating interlayer of the water heater by using the nano heat-insulating material as claimed in claim 1 is characterized by comprising the following steps of:

buckling a layer of integral forming mold with a heating function outside the inner container of the water heater, injecting a nano heat-insulating material into an interlayer between the inner container and the mold at normal temperature and normal pressure, heating to 100-150 ℃, and keeping for 1-3h for forming to obtain an aerogel heat-insulating blank;

and secondly, putting the aerogel heat insulation blank obtained in the step one into equipment, steaming for 4-24h at the temperature of 60-100 ℃, and opening the mould to obtain the water heater nano heat insulation interlayer.

8. The method for preparing the nano heat-insulating interlayer of the water heater by using the nano heat-insulating material according to claim 7, wherein the integrally-formed mold in the step one is of a left-right structure and consists of a left half mold (1) with a jacket, a right half mold (2) with a jacket and a sealing ring (3); a left heat conduction oil inlet (1-1) is arranged at the lower part of the left half mould (1), and a left heat conduction oil outlet (1-2) is arranged at the upper part of the left half mould (1); a right heat conduction oil inlet (2-1) is arranged at the lower part of the right half die (2), and a right heat conduction oil outlet (2-2) is arranged at the upper part of the right half die (2); the left half die (1) and the right half die (2) are spliced to form a cavity, the cavity completely covers the water heater liner (4), the distance between the inner surface of the cavity and the outer surface of the water heater liner (4) is 1-3cm, and the spliced part of the left half die (1) and the right half die (2) is sealed by a sealing ring (3); heat conducting oil is introduced into the jackets of the left half mould (1) and the right half mould (2) to heat the mould.

9. The method for preparing the nano heat-insulating interlayer for the water heater by using the nano heat-insulating material according to claim 7 or 8, wherein the forming temperature in the step one is 120 ℃ and the heat-insulating time is 2 hours.

10. The method for preparing the nano heat-insulating interlayer of the water heater by using the nano heat-insulating material according to the claim 7 or 8, wherein the steam curing temperature in the step two is 80 ℃ and 8 hours.

Technical Field

The invention relates to a preparation method of a nano heat-insulating material and an interlayer of a water heater.

Background

The water heater is a necessary good product for the family life of common people. With the popularization of water heaters, the safety and energy saving problems of the water heaters become hot spots of general attention of various manufacturers, and the most relevant water heater component is the heat preservation interlayer of the inner container. At present, polyurethane foam, polyether polyol foam, vacuum insulation panels and the like are mainly used as heat insulation interlayer materials. The Chinese patent with publication number CN107814906A discloses a solar water heater prepared by using a polyurethane foam heat-insulating material, which has good heat-insulating property, but the material has large shrinkage after foaming and unstable yield; the chinese patent publication No. CN109354856A discloses a heat insulating material for a water heater, which is prepared by using polyether polyol foam as a main raw material, and although the problem of large shrinkage of a finished product is solved, the process is more complicated and is not beneficial to industrial production; the chinese patent No. CN109595796A discloses a method for preparing a heat-insulating interlayer of a water heater by using a vacuum heat-insulating plate as a main heat-insulating material, wherein the vacuum heat-insulating plate has excellent heat-insulating capability, but has poor flexibility, and further needs to add polyurethane foam to fill up the gap, so that the overall process is complex, the vacuum of the vacuum heat-insulating plate is easy to break during processing, and the operation requirement is high.

Disclosure of Invention

The invention provides a nanometer thermal insulation material and a preparation method and application thereof, aiming at solving the technical problems of high thermal conductivity coefficient, complex process, poor flame-retardant insulation property and large shrinkage rate of finished products of the existing thermal insulation interlayer material of a water heater.

The nanometer heat-insulating material is prepared from 20-40 parts of main filler, 10-20 parts of auxiliary filler, 100-150 parts of binder and 5-15 parts of chopped fiber in parts by weight; wherein the main material is silicon dioxide aerogel powder or a mixture of fumed silica and silicon dioxide aerogel powder; the auxiliary material is one or the combination of a plurality of carbon black, silicon carbide, potassium hexatitanate whisker, titanium dioxide, gas phase alumina and hollow glass microballoon.

Furthermore, the binder is one or a combination of several of sodium silicate, silica sol, acrylic resin, epoxy resin, amino resin and organosilicon modified styrene-acrylic emulsion.

Further, the chopped fiber is one or a combination of several of high silica fiber, glass fiber, rock wool fiber, aluminum silicate fiber and mullite fiber.

The preparation method of the nano heat-insulating material comprises the following steps:

weighing 20-40 parts of main filler, 10-20 parts of auxiliary filler, 100-150 parts of binder and 5-15 parts of chopped fiber according to the weight ratio; wherein the main filler is silicon dioxide aerogel powder and/or fumed silica; the auxiliary material is one or the combination of a plurality of carbon black, silicon carbide, potassium hexatitanate whisker, titanium dioxide, gas phase alumina and hollow glass microballoon;

secondly, putting the main filler, the auxiliary filler and the binder in the step one into a dispersion machine, and dispersing for 1-12 hours at room temperature to obtain a mixture;

and thirdly, adding the chopped fibers in the step one into the mixture in the step two, and continuously dispersing for 0.5-6h at room temperature to obtain the nano heat-insulating material.

Furthermore, the binder in the first step is one or a combination of several of sodium silicate, silica sol, acrylic resin, epoxy resin, amino resin and organosilicon modified styrene-acrylic emulsion.

Further, the chopped fibers in the first step are one or a combination of several of high silica fibers, glass fibers, rock wool fibers, aluminum silicate fibers and mullite fibers.

The method for preparing the water heater nanometer heat-insulating interlayer by utilizing the nanometer heat-insulating material comprises the following steps:

buckling a layer of integral forming mold with a heating function outside the inner container of the water heater, injecting a nano heat-insulating material into an interlayer between the inner container and the mold at normal temperature and normal pressure, heating to 100-150 ℃, and keeping for 1-3h for forming to obtain an aerogel heat-insulating blank;

and secondly, putting the aerogel heat insulation blank obtained in the step one into steam curing equipment, performing steam curing for 4-24 hours at the temperature of 60-100 ℃, and opening the mould to obtain the water heater nano heat insulation interlayer.

Furthermore, the integrated forming die in the step one is of a left-right structure and consists of a left half die 1 with a jacket, a right half die 2 with a jacket and a sealing ring 3; a left heat conduction oil inlet 1-1 is arranged at the lower part of the left half die 1, and a left heat conduction oil outlet 1-2 is arranged at the upper part of the left half die 1; a right heat conduction oil inlet 2-1 is arranged at the lower part of the right half die 2, and a right heat conduction oil outlet 2-2 is arranged at the upper part of the right half die 2; the left half die 1 and the right half die 2 are spliced to form a cavity, the cavity completely covers the water heater liner 4, the distance between the inner surface of the cavity and the outer surface of the water heater liner 4 is 1-3cm, and the spliced part of the left half die 1 and the right half die 2 is sealed by a sealing ring 3; heat conducting oil is introduced into the jackets of the left half mould 1 and the right half mould 2 to heat the mould.

Fig. 1 is a schematic front view of the integral molding die, fig. 2 is a schematic side view of the integral molding die, and fig. 3 is a schematic top view of the integral molding die.

Furthermore, the forming temperature in the step one is 120 ℃, and the heat preservation time is 2 hours.

Furthermore, the steam curing temperature in the step two is 80 ℃, and the steam curing temperature is 8 h.

The nano heat-insulating material takes aerogel and fumed silica as main fillers, both the two nano materials have larger specific surface areas and nano-scale pore channel structures, the heat conduction is effectively blocked, the heat conductivity coefficient is extremely low to 0.020W/(m.K) (75 ℃), and the material system after mixing is hydrophobic, moistureproof, flame-retardant, insulating, safe and energy-saving.

The integrated forming die with the heating function used in the method for preparing the nano heat-insulating interlayer of the water heater can be heated to a certain temperature during mixed material thermal forming, and the integrated forming technology greatly simplifies the process manufacturing difficulty and saves a large amount of resources. The thermal forming technology is utilized to carry out curing treatment on the mixed materials, the method can reduce the shrinkage rate of the finished product to 0.8 percent, reduce the volume effect, and greatly improve the structural stability of the product. The material is further solidified by adopting a steam curing technology, the structural stability of the material is improved, the material is light and high in strength, the use is safer, and the service life is longer.

Drawings

FIG. 1 is a front view of the mold of the present invention;

FIG. 2 is a schematic side view of the integrated mold of the present invention;

fig. 3 is a schematic top view of the integral molding die of the present invention.

Detailed Description

The following examples are used to demonstrate the beneficial effects of the present invention.

Example 1: the preparation method of the nano heat-insulating material of the embodiment is carried out according to the following steps:

weighing 30 parts of main filler, 15 parts of auxiliary filler, 125 parts of binder and 10 parts of chopped fiber according to the weight ratio; wherein the main material is silicon dioxide aerogel powder; the auxiliary material is a uniform mixture of 5 parts of silicon carbide, 5 parts of potassium hexatitanate whiskers and 5 parts of vapor phase alumina, the binder is sodium silicate, and the chopped fibers are high silica fibers with the length of 5 mm;

secondly, putting the main filler, the auxiliary filler and the binder in the step one into a dispersion machine, and dispersing for 4 hours at room temperature to obtain a mixture;

and thirdly, adding the chopped fibers in the step one into the mixture in the step two, and continuously dispersing for 3 hours at room temperature to obtain the nano heat-insulating material.

The method for preparing the water heater nanometer heat-insulating interlayer by using the nanometer heat-insulating material in the embodiment 1 comprises the following steps:

the method comprises the following steps that firstly, a layer of integral forming die with a heating function is buckled outside a liner of the water heater, wherein the integral forming die consists of a left half die 1 with a jacket, a right half die 2 with the jacket and a sealing ring 3; a left heat conduction oil inlet 1-1 is arranged at the lower part of the left half die 1, and a left heat conduction oil outlet 1-2 is arranged at the upper part of the left half die 1; a right heat conduction oil inlet 2-1 is arranged at the lower part of the right half die 2, and a right heat conduction oil outlet 2-2 is arranged at the upper part of the right half die 2; the left half die 1 and the right half die 2 are spliced to form a cavity, the cavity completely covers the water heater liner 4, the distance between the inner surface of the cavity and the outer surface of the water heater liner 4 is 2cm, and the splicing part of the left half die 1 and the right half die 2 is sealed by a sealing ring 3; heat conducting oil is introduced into the jackets of the left half die 1 and the right half die 2 to heat the die; injecting a nano heat-insulating material into an interlayer between the inner container 4 and the mold at normal temperature and normal pressure, introducing heat-conducting oil into the jackets of the left half mold 1 and the right half mold 2 to heat the mold to 120 ℃, and keeping the temperature for 2 hours for molding to obtain an aerogel heat-insulating blank;

and secondly, putting the aerogel heat insulation blank obtained in the step one into steam curing equipment, performing steam curing for 12 hours at the temperature of 80 ℃, and opening the mould to obtain the water heater nano heat insulation interlayer.

Control group 1: the preparation method of the nano heat-insulating material of the control group is carried out according to the following steps:

weighing 50 parts of main filler, 10 parts of auxiliary filler, 150 parts of binder and 20 parts of chopped fiber according to the weight ratio; wherein the main material is fumed silica; the auxiliary material is 10 parts of silicon carbide, the binder is sodium silicate, and the chopped fibers are high silica fibers with the length of 5 mm;

secondly, putting the main filler, the auxiliary filler and the binder in the step one into a dispersion machine, and dispersing for 4 hours at room temperature to obtain a mixture;

and thirdly, adding the chopped fibers in the step one into the mixture in the step two, and continuously dispersing for 3 hours at room temperature to obtain the nano heat-insulating material.

Control group 2: the preparation method of the nano heat-insulating material of the control group is carried out according to the following steps:

weighing 40 parts of main filler, 10 parts of auxiliary filler, 150 parts of binder and 20 parts of chopped fiber according to the weight ratio; wherein the main material is fumed silica; the auxiliary materials are 5 parts of silicon carbide and 5 parts of vapor phase aluminum oxide, the binder is sodium silicate, and the chopped fibers are high silica fibers with the length of 5 mm;

secondly, putting the main filler, the auxiliary filler and the binder in the step one into a dispersion machine, and dispersing for 4 hours at room temperature to obtain a mixture;

and thirdly, adding the chopped fibers in the step one into the mixture in the step two, and continuously dispersing for 3 hours at room temperature to obtain the nano heat-insulating material.

Control group 3: the preparation method of the nano heat-insulating material of the control group is carried out according to the following steps:

weighing 40 parts of main filler, 10 parts of auxiliary filler, 150 parts of binder and 20 parts of chopped fiber according to the weight ratio; wherein the main materials are 20 parts of fumed silica and 20 parts of aerogel powder; the auxiliary materials are 5 parts of silicon carbide and 5 parts of vapor phase aluminum oxide, the binder is sodium silicate, and the chopped fibers are high silica fibers with the length of 5 mm;

secondly, putting the main filler, the auxiliary filler and the binder in the step one into a dispersion machine, and dispersing for 4 hours at room temperature to obtain a mixture;

and thirdly, adding the chopped fibers in the step one into the mixture in the step two, and continuously dispersing for 3 hours at room temperature to obtain the nano heat-insulating material.

The specific method for preparing the test sample by using the nano heat-insulating materials of the embodiment 1 and the comparison groups 1, 2 and 3 respectively comprises the following steps:

adding the nano heat-insulating material into a cuboid mold with the cavity length, width and height of 200mm, 100mm and 50mm respectively, placing the mold in an oven, heating to 120 ℃, and keeping for 2h for molding to obtain a test sample.

The test sample prepared by using the nano heat-insulating material in the embodiment 1 is further put into steam curing equipment, steam cured for 12 hours at the temperature of 80 ℃, and opened to obtain a post-cured test sample.

The test samples prepared in example 1, control 2, and control 3 and the post-cured test samples were tested for thermal conductivity, shrinkage, and density, with the results shown in table 1:

TABLE 1 test results of samples of example 1, control 2 and control 3

As can be seen from table 1, the thermal conductivity of the test sample of the nano thermal insulation material prepared in this example 1 is lower than that of the other three groups, the shrinkage rate is much lower than that of the other three groups, and the density is relatively low. Meanwhile, comparing the performance results of the test sample of example 1 and the test sample cured after steam curing, it can be seen that the thermal conductivity and shrinkage of the material can be further reduced by the steam curing operation due to the post-curing result during the steam curing process.

Example 2: the preparation method of the nano heat-insulating material of the embodiment is carried out according to the following steps:

weighing 30 parts of silicon dioxide aerogel powder, 10 parts of fumed silica, 10 parts of silicon carbide, 5 parts of potassium hexatitanate whisker, 5 parts of fumed alumina, 125 parts of silica sol and 10 parts of aluminum silicate fiber with the length of 5mm according to the weight ratio;

secondly, putting the silicon dioxide aerogel powder, the fumed silica, the silicon carbide, the potassium hexatitanate whisker, the fumed alumina and the silica sol in the step one into a dispersion machine, and dispersing for 12 hours at room temperature to obtain a mixture;

and thirdly, adding the aluminum silicate fibers in the step one into the mixture in the step two, and continuously dispersing for 5 hours at room temperature to obtain the nano heat-insulating material.

Adding the nano heat-insulating material of the embodiment 2 into a cuboid mold with the cavity length, width and height of 200mm, 100mm and 50mm respectively, placing the mold in an oven, heating to 120 ℃, and keeping for 2 hours for molding to obtain a sample blank; and putting the sample blank into steam curing equipment, performing steam curing at the temperature of 80 ℃ for 12 hours, and opening the die to obtain the test sample. The test results are shown in table 2:

TABLE 2 Properties of the Nano-insulation of example 2

Example 3: the preparation method of the nano heat-insulating material of the embodiment is carried out according to the following steps:

weighing 30 parts of silicon dioxide aerogel powder, 20 parts of fumed silica, 7 parts of silicon carbide, 8 parts of potassium hexatitanate whisker, 5 parts of hollow glass microsphere, 120 parts of acrylic resin and 10 parts of glass fiber with the length of 5mm according to the weight ratio;

secondly, placing the silicon dioxide aerogel powder, the fumed silica, the silicon carbide, the potassium hexatitanate whisker, the hollow glass bead and the acrylic resin in the first step into a dispersion machine, and dispersing for 12 hours at room temperature to obtain a mixture;

and thirdly, adding the glass fiber obtained in the first step into the mixture obtained in the second step, and continuously dispersing for 5 hours at room temperature to obtain the nano heat-insulating material.

Adding the nano heat-insulating material of the embodiment 3 into a cuboid mold with the cavity length, width and height of 200mm, 100mm and 50mm respectively, placing the mold in an oven, heating to 120 ℃, and keeping for 2 hours for molding to obtain a sample blank; and putting the sample blank into steam curing equipment, performing steam curing at the temperature of 80 ℃ for 12 hours, and opening the die to obtain the test sample. The test results are shown in table 3:

TABLE 3 Properties of the Nano-insulation of example 2

The above examples and test data show that the preparation method of the nano thermal insulation material and the interlayer in the invention better meet the technical performance requirements of the thermal insulation material for the water heater, and is more suitable for being used as the thermal insulation material interlayer for the water heater in performance and process.