WO2015002488A1

WO2015002488A1 - Heat-insulating composition, method of preparing the same, and heat-insulating element using the same

Info

Publication number: WO2015002488A1
Application number: PCT/KR2014/005972
Authority: WO
Inventors: Jeong-Kun Yoo; Eun-Yong Lee; Doo-Suk PARK; Jung-Ho Han
Original assignee: Remtech Co., Ltd.
Priority date: 2013-07-04
Filing date: 2014-07-03
Publication date: 2015-01-08
Also published as: KR20150005753A; CN105452387A; KR101804345B1; CN105452387B

Abstract

A heat-insulating composition, a method of preparing the same, and a heat-insulating element using the same are provided. The heat-insulating composition includes water, a super absorbent polymer (SAP), a hydrophobic powder, and a silicon binder. The method of preparing a heat-insulating composition includes producing a gelatinous aqueous solution by mixing water and a super absorbent polymer (SAP) with each other, obtaining a waterborne mixture by adding a hydrophobic powder to the gelatinous aqueous solution to be accompanied with stirring, and adding a silicon binder to the waterborne mixture. The heat-insulating element includes a heat-insulating substrate, and a heat insulation composition layer formed on the heat-insulating substrate.

Description

HEAT-INSULATING COMPOSITION, METHOD OF PREPARING THE SAME, AND HEAT-INSULATING ELEMENT USING THE SAME

The present disclosure relates to a heat-insulating composition, a method of preparing the same, and a heat-insulating element using the same, and more particularly, to a composition containing a hydrophobic powder and a silicon binder, capable of maintaining heat insulation characteristics when the hydrophobic powder is formed of an aerogel material, a method of preparing the same and a heat-insulating element using the same.

An aerogel material having hydrophobic properties and a porous structure has been used in certain applications due to the heat insulating, thermal barrier and similar properties thereof, and in particular, silicon aerogel is a representative heat insulation material. However, in spite of having excellent heat insulation performance, thermal barrier performance and acoustic absorption performance, to date, the practical application of aerogel material is low, across all industrial fields, due to the relatively high cost thereof. In addition to being relatively expensive, the lack of widespread aerogel use is also due to a lack of a binder application technology based on the hydrophobic properties of aerogel.

In particular, when heat insulating paint, heat-insulating coating agents, heat-insulating boards, heat-insulating fiber blankets, heat shields for automobiles, heat-insulating materials for high-temperature pipes, or the like are produced, in the case of mixing aerogel therewith as a heat-insulating material, the heat insulation properties and thermal barrier performance of such insulation products may be remarkably improved. Therefore, research into an application technology therefor has been actively undertaken.

However, in such a technological application there may be difficulties in terms of mixing an aerogel material with a binder material due to the hydrophobic properties and porous characteristics of the aerogel.

For example, in the case of using a soluble binder, difficulties in light of mixing such a binder, due to hydrophobic aerogel properties in which the hydrophobic aerogel is not mixed with water are present, and in the case of using an organic binder in order to solve such difficulties, even in the case that hydrophobic aerogel is well mixed with an organic binder, an organic binder having fluidity may infiltrate into the fine pores of aerogel.

As a result, since the majority of an organic binder may be absorbed into the aerogel, viscosity of the mixture may be considerably increased, and thus, a problem in which a coating process for the formation of a paint film may not be properly performed may occur. In this case, inefficiently, the amount of the binder should be increased by a significant amount, and fine pores in the aerogel may thus be filled with organic binders as illustrated in FIG. 1. Thus, an expected degree of performance provided by using a heat-insulating material may not be exhibited. Here, since excellent aerogel heat insulation properties may be obtained through a large number of pores formed in an interior portion of the aerogel, and since the pores may be filled by the binder, the majority of heat insulation properties may not be realized.

For example, even in a case in which an organic binder is mixed with aerogel, in order to obtain a uniformly mixed composition while maintaining the heat insulation properties of aerogel, a technology for preventing the organic binder from infiltrating into fine pores of the aerogel may be technologically significant.

Accordingly, in a case in which an aerogel composition may be obtained as a composition mixed efficiently with a binder while maintaining aerogel composition properties, it is expected that the composition may be usefully used in applications relevant to heat insulation, thermal barriers, acoustic absorption, and the like.

Some embodiments of the present disclosure may provide a heat-insulating composition having excellent heat insulation effects while maintaining hydrophobic powder properties.

Some embodiments of the present disclosure may provide a method of effectively preparing the heat-insulating composition.

Some embodiments of the present disclosure may provide an excellent heat-insulating element using a heat-insulating composition of the present disclosure.

According to some embodiments of the present disclosure, a heat-insulating composition may include water, a super absorbent polymer (SAP), a hydrophobic powder, and a silicon binder.

The super absorbent polymer (SAP)may include at least one selected from a group consisting of poly acrylamide, polyacrylic acid, polymethacrylic acid, polyethylene oxide, polyvinyl alcohol, gelatin, polysaccharide, cellulose or derivatives thereof, and chitosan, or a salt thereof.

The hydrophobic powder may be one or more selected from a group consisting of a silica aerogel powder, a hydrophobic (Si, Ca, Al, Mg)xOy mineral powder, an inorganic compound surface-treated with hydrophobic silane, and an organic compound surface-treated with hydrophobic silane.

The silicon binder may include a silicon resin represented by the following Formula (1) and an organic diluent at a weight ratio of 30 to 90:10 to 70,

where R₁ to R₈ are respectively and independently selected from a group consisting of hydrogen, C₁ _-8 alkyl, C₆ _-10 aryl, and C₃ _-8 cycloalkyl, and n indicates an integer of from 1 to 100,000.

The R₁ to R₈ may be respectively and independently selected from a group consisting of methyl, ethyl, and phenyl.

The organic diluent may be one or more selected from a group consisting of xylene, ethylbenzene, alcohol and water.

A weight ratio of the super absorbent polymer (SAP) to the water may be in a range of 1:50 to 1:1000.

A weight ratio of the super absorbent polymer (SAP) to the hydrophobic powder may be in a range of 1:10 to 1:500.

The silicon binder may be contained in an amount of 50 to 150 parts by weight, based on 100 parts by weight of the total weight of the water, the super absorbent polymer (SAP) and the hydrophobic powder.

According to some embodiments of the present disclosure, a method of preparing a heat-insulating composition may include producing a gelatinous aqueous solution by mixing water and a super absorbent polymer (SAP), obtaining a waterborne mixture by adding a hydrophobic powder to the gelatinous aqueous solution to be accompanied with stirring, and adding a silicon binder to the waterborne mixture.

According to some embodiments of the present disclosure, a heat-insulating element may include a heat-insulating substrate, and a heat insulation composition layer formed on the heat-insulating substrate using the heat-insulating composition described above.

The heat-insulating substrate may be formed using a material selected from a group consisting of a silica fiber, a glass fiber, mineral wool (rock wool), ceramic wool, a polymer fiber and a carbon fiber.

According to exemplary embodiments of the present disclosure, a heat-insulating composition appropriate for forming a high-temperature thermal barrier and heat insulation, while not affecting hydrophobic powder properties, in detail, aerogel powder properties may be obtained. Further, by using the heat-insulating composition according to an exemplary embodiment of the present disclosure, a heat-insulating and thermal barrier element having excellent economic value may be easily realized.

FIG. 1 is a drawing illustrating a procedure in which fine pores of aerogel are filled with a binder and thus heat-insulating performance thereof may not be exhibited;

FIG. 2 illustrates a procedure in which in the case of a heat-insulating composition according to an exemplary embodiment of the present disclosure, aerogel particles are coated with a soluble material to prevent the binder from infiltrating into fine pores of the aerogel;

FIG. 3 is an image illustrating a case in which when an iron plate is covered with a heat-insulating composition according to Example 1 of the present disclosure, adhesive strength of the heat-insulating composition with respect to the iron plate is excellent; and

FIG. 4 is an image illustrating a case in which when an iron plate is covered with a heat-insulating composition according to Example 2 of the present disclosure, adhesive strength of the heat-insulating composition with respect to the iron plate is excellent.

Exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The disclosure may, however, be exemplified in many different forms and should not be construed as being limited to the specific embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. In the drawings, the shapes and dimensions of elements may be exaggerated for clarity, and the same reference numerals will be used throughout to designate the same or like elements.

According to an exemplary embodiment of the present disclosure, a heat-insulating composition including water, a super absorbent polymer (SAP), a hydrophobic powder, and a silicon binder is provided.

A heat-insulating composition according to an exemplary embodiment of the present disclosure may be prepared through a process of mixing a hydrophobic aerogel powder with water and a super absorbent polymer (SAP) before mixing the hydrophobic aerogel powder with a binder to thus produce an aqueous solution in a gelatinous state, adding a hydrophobic powder thereto to then be agitated so as to obtain a waterborne mixture, and then mixing a binder therewith, such that aerogel particles are coated with a soluble material. Therefore, the binder may be prevented from infiltrating into fine pores of aerogel as illustrated in FIG. 2.

Thus, in such a state, when the heat-insulating composition according to the exemplary embodiment of the present disclosure is dried, a volatile component within the binder and a soluble material of which the majority is formed of water may vaporize, volatilize and disappear. Then, adhesion between aerogel particle surfaces may be performed through adhesive strength of the remaining binder. For example, the basic purpose of using the binder is to provide adhesive strength between particles, but in a case in which the binder is introduced into the interior of particle pores, the use of the binder may not be efficient.

According to an exemplary embodiment of the present disclosure, the infiltration of a binder into particles may be prevented to only provide particle surfaces with adhesive strength and further significantly exhibit particle specific properties, for example, heat-insulating properties.

The term, 'Heat-insulating used in the present specification may be understood as having a comprehensive meaning including the meaning of heat resistance and a thermal barrier.

According to an exemplary embodiment of the present disclosure, a hydrophobic powder such as hydrophobic aerogel or the like may be used to obtain a heat-insulating composition mixed stably and uniformly while maintaining hydrophobic powder properties, and may thus have significant utilization. For example, when aerogel is mixed with a generally used binder, the binder may infiltrate into pores of aerogel to deteriorate aerogel specific properties, in detail, heat insulation properties. However, according to an exemplary embodiment of the present disclosure, effective heat insulation properties may be provided without such deterioration in aerogel properties.

In the case of the SAP of the present disclosure, when the SAP is mixed with water, the SAP has the nature of absorbing water and swelling to become gelatinized. Here, the SAP is a material capable of absorbing an amount of water equal to 1000 times the body weight thereof at maximum, so as to maintain a relatively high level of viscosity in a gelatinous state. Since such a SAP mixed aqueous solution in a gelatinous state may only remain as a solid phase in an extremely small amount even after the water is dried, the hydrophobic powder properties are not affected thereby.

The SAP used in the present disclosure may contain at least one selected from a group consisting of poly acrylamide, polyacrylic acid, polymethacrylic acid, polyethylene oxide, polyvinyl alcohol, gelatin, polysaccharide, cellulose or derivatives thereof, and chitosan, or a salt thereof. In detail, polyacrylic acid or a salt thereof may be contained in the SAP.

For example, sodium polyacrylate is a white powder, a substance having no smell or taste, a polymer of sodium acrylate, as well as being hydrophilic, and has a relatively high level of water absorption. The sodium polyacrylate slowly dissolves in water to become a transparent gel-phase liquid having a relative high level of viscosity. Since such viscosity in sodium polyacrylate is provided due to an ion phenomenon in which a large amount of anions exist within molecules and a level of apparent viscosity is thus increased so as to be able to form a relatively high viscosity solution, an addition amount thereof may be reduced. In addition, since heat resistance of the sodium polyacrylate is relatively high, it is not decomposed at a temperature of about 300℃, such that there is little resultant deterioration. Thus, the sodium polyacrylate may also be used in thermally processed food. In addition, since the possibility of being decayed or spoiling such as in natural substances is not present, storage properties thereof may be improved.

In a method of producing sodium polyacrylate, by way of an example, acrylic acid or acrylic ester may be used as a raw material and gummed by sodium hydroxide to obtain an acrylic monomer. Here, alcohol generated during concentrating the acrylic monomer may be removed. The concentration of this concentrated sodium acrylate monomer is adjusted, pH thereof is controlled using sodium hydroxide, and then, ammonium peroxysulfate is applied thereto as a polymerization catalyst. The polymerization obtained thereby may be a gel-phase, and may be dried, ground, and sieved to thus obtain sodium polyacrylate.

Cellulose or derivatives thereof may contain modified cellulose as illustrated in a case in which hydrogen bonding is formed between -OH groups of cellulose, for example, as in cellulose nitrate, cellulose acetate, carboxymethyl cellulose, or the like.

However, the SAP used in the present disclosure is not limited to containing such ingredients, and any SAPs may be used as long as water absorbing power thereof is 50g/g or higher, and in detail, SAP having water absorbing power of 50 to 1000g/g or higher may be used. In further detail, SAP having water absorbing power of 300 to 500g/g may be used.

In a case in which the water absorption power of the SAP is less than 50g/g, since water absorption capacity is insufficient, a relatively large amount of a high absorption polymer should be used, such that the SAP remains, affecting final physical properties of the hydrophobic powder.

A weight ratio of the SAP to water may be in the range of 1:50 to 1:1000. When the SAP is contained in an amount less than this range, since the amount of the SAP is excessively small as compared to that of water, the viscosity of a heat-insulating composition may not reach a level appropriate therefor. When the SAP is contained in an amount exceeding this range, since the amount of the SAP is excessively high, the viscosity of the heat-insulating composition is relatively high. Thus, mixing the composition with a hydrophobic powder may not be properly performed. Therefore, a weight ratio of the SAP to water may be within the range of 1:100 to 1:500.

On the other hand, a weight ratio of the SAP to a hydrophobic powder may be in the range of 1:10 to 1:500, in further detail, in the range of 1:100 to 1:200.

When the hydrophobic powder is contained in an amount less than this range, since the amount of the hydrophobic powder in the heat-insulating composition is significantly low, a problem of inefficiency in implementing hydrophobic powder properties may be present. When the hydrophobic powder is contained in an amount exceeding this range, since the volume of the hydrophobic powder particles is excessively large, a difficulty in view of realizing a heat-insulating composition having a necessary form such as a uniformly dispersed fluid gel or liquid phase may be present.

An average particle size of the hydrophobic powder according to an exemplary embodiment of the present disclosure may be in the range of 0.001mm to 5mm, and in detail, 0.01mm to 0.15mm. For example, the hydrophobic powder having the average particle size of 0.001mm to 5mm may be used in terms of viscosity control, an available mixing amount, and uniform mixing.

The viscosity of the heat-insulating composition of the hydrophobic powder may be in the range of 100 to 200,000cp, in detail, 1,000 to 20,000cp. When the viscosity of the heat-insulating composition of the hydrophobic powder is less than 100cp, a problem in which aerogel and moisture are phase separated and thus not be mixed with each other is present. In addition, when the viscosity of the heat-insulating composition of the hydrophobic powder exceeds 200,000 cp, since the viscosity may be excessively high, an agitation process may not be properly performed.

On the other hand, the hydrophobic powder is a porous hydrophobic powder, and may be one or more selected from a group consisting of a hydrophobic silica aerogel powder, a hydrophobic (Si, Ca, Al, Mg)xOy mineral powder, an inorganic compound surface-treated with hydrophobic silane, and an organic compound surface-treated with hydrophobic silane. As the mineral powder, for example, a perlite powder may be used, but the present disclosure is not limited thereto. Such a perlite powder may be hydrophobically treated as in a hydrophobic silane surface treatment.

As the silica aerogel powder used in the present disclosure, all types of aerogel powder in which a porous surface of aerogel is hydrophobically reformed may be used. In addition, any hydrophobic silica aerogel powder commonly known in the art may be used without particular limitations.

For example, the hydrophobic silica aerogel refers to hydrophobically surface-treated silica aerogel so as to prevent the absorption of moisture in air thereinto. The hydrophobic surface treatment may be performed using any method commonly known in the related art. For example, silylation-treated silica aerogel or the like may be used, but the present disclosure is not limited thereto.

On the other hand, the hydrophobic (Si, Ca, Al, Mg)xOy mineral powder may refer to a hydrophobic mineral powder such as CaO, MgO, Al₂O₃, or the like, wherein x indicates 1 to 9 and y indicates 1 to 9, and within this number range, it may be determined to constitute a compound.

Furthermore, the silicon binder used in the present disclosure may contain a silicon resin represented by the following formula (1) and an organic diluent at a weight ratio of 30 to 90:10 to 70. When the silicon resin represented by Formula (1) is contained in an amount less than 30 parts by weight, with respect to 100 parts by weight of a silicon binder, a problem in terms of adhesive strength may be present due to a lack of an absolute amount of a binder. In addition, when the silicon resin is contained in an amount exceeding 90 parts by weight, with respect to 100 parts by weight of a silicon binder, a mixing process may not be properly performed due to an excessive level of viscosity.

In Formula (1), R₁ to R₈ may be respectively and independently selected from a group consisting of hydrogen, C₁ _-8 alkyl, C₆ _-10 aryl, and C₃ _-8 cycloalkyl, and n refers to an integer of from 1 to 100,000. In further detail, R₁ to R₈ may be respectively and independently selected from a group consisting of methyl, ethyl, and phenyl, and here, the phenyl may be substituted with C₁ _-8 alkyl or the like.

Further, the organic diluent may be aromatic hydrocarbon, alcohol or water, and in further detail, the aromatic hydrocarbon may be one or more selected from a group consisting of xylene, ethylbenzene, alcohol and water.

On the other hand, the silicon binder may be mixed with an additional, auxiliary binder. In this case, the auxiliary binder may be at least one selected from a group consisting of water glass and colloidal silica.

The silicon binder may be contained in an amount of 50 to 150 parts by weight, based on 100 parts by weight of the total weight of the water, the SAP and the hydrophobic powder. In further detail, the silicon binder may have the same weight as the total weight of the water, the SAP and the hydrophobic powder, for example, may be contained at a weight ratio of 1:1. When the silicon binder is contained in an amount less than 50 parts by weight, based on 100 parts by weight of the total weight of the water, the SAP and the hydrophobic powder, since an absolute amount of the binder used as an adhesive component lacks, adhesive strength may not be realized. In addition, when the silicon binder is contained in an amount exceeding 150 parts by weight, an excessive amount of the binder may be consumed unnecessarily.

Further, the heat-insulating composition according to an exemplary embodiment of the present disclosure may further contain at least one additive selected from a group consisting of a surfactant, an inorganic filler, a hardener, a viscosity agent, and an antifoaming agent, as needed.

Further, the surfactant may be added such that the hydrophobic aerogel may be easily mixed with other ingredients, as needed. As the surfactant, any surfactant commonly known in the art may be used, and for example, alcohols such as ethanol, polyethylene glycol (PEG), and the like, may be used alone or in a combination of two or more thereof, but a surfactant type is not limited thereto.

The inorganic filler may be further added in view of economy and temperature resistance. As the inorganic filler, any inorganic filler commonly known in the art may be used, and for example, a red ochre powder, mica, talc, silica, diatomite, perlite, vermiculite, activated charcoal, zeolite, a hollow ceramic body, a hollow silicate body, or the like may be used, but the present disclosure is not limited thereto. These inorganic fillers may be used alone or together in two or more thereof.

When such an inorganic filler is used, since heat insulation properties of a heat-insulating composite may be deteriorated as compared to the case in which only hydrophobic aerogel is used, a separate inorganic filler may not be added in view of heat insulation properties. However, in economic aspects, the inorganic filler may be used together.

Such other additive may be contained in an amount of 0.01 to 100 parts by weight, based on 100 parts by weight of a waterborne composition.

The heat-insulating composition according to an exemplary embodiment of the present disclosure may have the form able to be usefully used for a coating process, the formation of a paint film, or the formation of a heat insulation layer.

A method of preparing a heat-insulating composition according to an exemplary embodiment of the present disclosure may include producing a gelatinous aqueous solution by mixing water and a super absorbent polymer (SAP) with each other; obtaining a waterborne mixture by adding a hydrophobic powder thereto to be accompanied with stirring, and adding a silicon binder to the waterborne mixture. Properties and the contents of the heat-insulating composition according to the exemplary embodiment of the present disclosure are as described above according to the foregoing exemplary embodiment of the present disclosure.

According to an exemplary embodiment of the present disclosure, first, a waterborne mixture having excellent dispersion properties, in which hydrophobic powder particles are stably dispersed, may be prepared. Such a waterborne mixture may not have the occurrence of phase separation for a significantly long time. Subsequently, such waterborne mixture may be added with a silicon binder so as to obtain a uniformly mixed heat-insulating composition.

Therefore, a coating process or the formation of a paint film may be easily performed while having improved characteristics, by including a hydrophobic powder such as aerogel or the like. In addition, at the time of handling hydrophobic powder particles, dust or the like may be problematic. However, according to the method of preparing a heat-insulating composition according to an exemplary embodiment of the present disclosure, a problem such as the occurrence of dust or the like may be solved. Therefore, the heat-insulating composition according to an exemplary embodiment of the present disclosure may be applied to various application fields relevant to heat resistance, heat insulation, thermal barriers, and the like.

By using the heat-insulating composition according to an exemplary embodiment of the present disclosure, a heat-insulating element having excellent heat insulation effects may be realized. The heat-insulating element may include a heat-insulating substrate, and a heat insulation composition layer formed on the heat-insulating substrate using the heat-insulating composition according to an exemplary embodiment of the present disclosure.

Here, the heat-insulating substrate may be formed using an inorganic heat-insulating material, for example, selected from a group consisting of a silica fiber, a glass fiber, mineral wool (rock wool), ceramic wool, a polymer fiber and a carbon fiber.

In addition, the heat-insulating substrate and the heat insulation composition layer may be alternately stacked twice or more, and in detail, 2 to 6 layers may be alternately stacked, respectively, but are not limited thereto. For example, a laminate including a proper amount of layers in the area of application in which the heat-insulating element is used may be manufactured.

On the other hand, the heat insulation composition layer may have a thickness of 1mm to 500mm, in detail, 2mm to 10mm. When the thickness of the heat insulation composition layer is less than 1mm, a problem in terms of molding properties and rigidity may be present, and when the thickness of the heat insulation composition layer exceeds 500mm, a problem in terms of economy may occur.

Hereinafter, the present disclosure will be described in further detail through detailed exemplary embodiments. The following examples are provided to assist in understanding the present disclosure by way of example, and thus, the scope of the present disclosure is not limited to the following examples.

[Example]

Example 1: Preparation of Heat-insulating Composition

An aqueous solution in a gelatinous state was prepared by mixing 10g of a super absorbent polymer (SAP) (HI-SWELL by SONGWON) and 5g of carboxymethyl cellulose with 200g of water. Here, the viscosity of the aqueous solution in a gelatinous state measured using a viscosity measuring apparatus (SV-10kv by AND LTD.) was 5200CP.

50g of aerogel was added to this aqueous solution to subsequently be mixed at 2500rpm for 20 minutes using a high speed agitator, and thus, a waterborne aerogel composition in which aerogel was uniformly dispersed was obtained.

100g of the obtained waterborne aerogel composition was mixed with 100g of a high-temperature silicon binder (a dry weight of 50%) and a heat-insulating composition was thus obtained.

Comparative Example 1: Preparation of Heat - Insulating Composition

An aqueous solution in a gelatinous state was prepared by mixing 10g of a super absorbent polymer (SAP) (HI-SWELL by SONGWON) and 5g of carboxymethyl cellulose with 200g of water. Here, the viscosity of the aqueous solution in a gelatinous state, measured using a viscosity measuring apparatus (SV-10kv by AND LTD.), was 5200CP.

100g of the obtained waterborne aerogel composition was mixed with 300g of a high-temperature silicon binder (a dry weight of 50%) and a heat-insulating composition was thus obtained.

Comparative Example 2: Preparation of Heat - Insulating Composition

An aqueous solution in a gelatinous state was prepared by mixing 10g of a super absorbent polymer (SAP) (HI-SWELL by SONGWON) and 5g of carboxymethyl cellulose with 200g of water. Here, the viscosity of the aqueous solution in a gelatinous state, measured using the viscosity measuring apparatus (SV-10kv by AND LTD.), was 5200CP.

100g of the obtained waterborne aerogel composition was mixed with 4g of a high-temperature silicon binder (a dry weight of 50%) and a heat-insulating composition was thus obtained.

Example 2: Manufacturing of Heat - Insulating Element

The heat-insulating composition obtained in Example 1 was coated on a glass fiber mat of about 0.5mm (a low density of 120g/m²) to then be stacked to have a thickness of 1mm and thus obtain a laminate, and the laminates were stacked to have four folds to then be dried at 120℃ for 3 hours so as to manufacture a heat-insulating element.

Example 3: Manufacturing of Heat - insulating element

100g of the obtained waterborne aerogel composition was mixed with 70g of a high-temperature silicon binder (a dry weight of 50%) and 30g of a water glass solution and a heat-insulating composition was thus obtained.

Example 4: Manufacturing of Heat - insulating element

100g of the obtained waterborne aerogel composition was mixed with 70g of a high-temperature silicon binder (a dry weight of 50%) and 30g of colloidal silica of 30% and a heat-insulating composition was thus obtained.

Example 5: Preparation of Heat - insulating composition

80g of a surface-hydrophobized perlite powder was added to this aqueous solution to subsequently be mixed at 2500rpm for 20 minutes using a high speed agitator, and thus, a composition in which the hydrophobized perlite powder was uniformly dispersed was obtained.

100g of the obtained composition was mixed with 100g of a high-temperature silicon binder (a dry weight of 50%) and a heat-insulating composition was thus obtained.

Experimental Example 1: Measurement of Heat Conductivity

The heat-insulating compositions obtained in Examples 1 to 5 and Comparative Examples 1 and 2 were coated on iron plates so as to have a thickness of 3mm to then be dried and thus manufacture samples having a size of 300?300?3mm as length x width x thickness. Then, thermal conductivity was measured therein using a thermal conductivity measuring apparatus. On the other hand, the samples were heated at 200℃, and surfaces of the samples on which the heat-insulating composition was coated were provided as external surfaces and temperatures of the external surfaces were measured.

(1) When the heat-insulating composition of Example 1 was used, thermal conductivity was 30mw/mk, and the heat-insulating composition was properly adhered to the iron plate, as illustrated in FIG. 3 and a temperature of the external surface of the sample was measured as 80℃.

(2) When the heat-insulating composition of Example 2 was used, thermal conductivity was 28mw/mk, and adhesive strength thereof on the iron plate was excellent, as illustrated in FIG. 4 and a temperature of the external surface of the sample was measured as 90℃.

(3) When the heat-insulating composition of Example 3 was used, thermal conductivity was 39mw/mk. The thermal conductivity was slightly reduced due to mixed water glass, but since water glass is a relatively low cost binder, it may be advantageous in view of economy. In addition, since water glass is a nonflammable inorganic material, a heat resistance temperature of a heat-insulating body manufactured using a heat-insulating composition such as the heat-insulating composition of Example 3 may be further increased. The heat-insulating composition of Example 3 exhibited a relatively high level of excellent adhesive strength at the time of being coated on the iron plate, and a temperature of the external surface of the sample was measured as 100℃.

(4) When the heat-insulating composition of Example 4 was used, thermal conductivity was 36mw/mk. The thermal conductivity was slightly reduced due to mixed colloidal silica, but since colloidal silica is a relatively low cost binder, it may be advantageous in view of economy. In addition, since colloidal silica is a nonflammable inorganic material, a heat resistance temperature of a heat-insulating body manufactured using a heat-insulating composition such as the heat-insulating composition of Example 4 may be further increased. The heat-insulating composition of Example 4 exhibited a relatively high level of excellent adhesive strength at the time of being coated on the iron plate, and a temperature of the external surface of the sample was measured as 100℃.

(5) When the heat-insulating composition of Example 5 was used, thermal conductivity was 68mw/mk.

(6) On the other hand, when the heat-insulating composition of Comparative Example 1 was used, thermal conductivity was 76mw/mk. Although adhesive strength of the heat-insulating composition of Comparative Example 1 on an iron plate was excellent, a temperature of the external surface of the sample was measured as 130℃. It could be appreciated that since an excessive amount of a binder was present, heat insulation performance was deteriorated.

(7) When the heat-insulating composition of Comparative Example 2 was used, since an amount of a binder was insufficient, adhesion with respect to an iron plate was not exhibited.

While exemplary embodiments have been shown and described above, it will be apparent to those skilled in the art that modifications and variations could be made without departing from the spirit and scope of the present disclosure as defined by the appended claims.

Claims

A heat-insulating composition comprising water, a super absorbent polymer (SAP), a hydrophobic powder, and a silicon binder.
The heat-insulating composition of claim 1, wherein the super absorbent polymer (SAP)comprises at least one selected from a group consisting of poly acrylamide, polyacrylic acid, polymethacrylic acid, polyethylene oxide, polyvinyl alcohol, gelatin, polysaccharide, cellulose or derivatives thereof, and chitosan, or a salt thereof.
The heat-insulating composition of claim 1, wherein the hydrophobic powder is one or more selected from a group consisting of a silica aerogel powder, a hydrophobic (Si, Ca, Al, Mg)xOy mineral powder, an inorganic compound surface-treated with hydrophobic silane, and an organic compound surface-treated with hydrophobic silane.
The heat-insulating composition of claim 1, wherein the silicon binder comprises a silicon resin represented by the following Formula (1) and an organic diluent at a weight ratio of 30 to 90:10 to 70:

where R₁ to R₈ are respectively and independently selected from a group consisting of hydrogen, C₁ _-8 alkyl, C₆ _-10 aryl, and C₃ _-8 cycloalkyl, and n indicates an integer of from 1 to 100,000.
The heat-insulating composition of claim 4, wherein the R₁ to R₈ are respectively and independently selected from a group consisting of methyl, ethyl, and phenyl.
The heat-insulating composition of claim 4, wherein the organic diluent is one or more selected from a group consisting of xylene, ethylbenzene, alcohol and water.
The heat-insulating composition of claim 1, wherein a weight ratio of the super absorbent polymer (SAP) to the water is in a range of 1:50 to 1:1000.
The heat-insulating composition of claim 1, wherein a weight ratio of the super absorbent polymer (SAP) to the hydrophobic powder is in a range of 1:10 to 1:500.
The heat-insulating composition of claim 1, wherein the silicon binder is contained in an amount of 50 to 150 parts by weight, based on 100 parts by weight of the total weight of the water, the super absorbent polymer (SAP) and the hydrophobic powder.
A method of preparing a heat-insulating composition, comprising:

producing a gelatinous aqueous solution by mixing water and a super absorbent polymer (SAP) with each other;

obtaining a waterborne mixture by adding a hydrophobic powder to the gelatinous aqueous solution to be accompanied with stirring; and

adding a silicon binder to the waterborne mixture.
The method of claim 10, wherein the super absorbent polymer (SAP)comprises at least one selected from a group consisting of poly acrylamide, polyacrylic acid, polymethacrylic acid, polyethylene oxide, polyvinyl alcohol, gelatin, polysaccharide, cellulose or derivatives thereof, and chitosan, or a salt thereof.
The method of claim 10, wherein the hydrophobic powder comprises one or more selected from a group consisting of a silica aerogel powder, a hydrophobic (Si, Ca, Al, Mg)xOy mineral powder, an inorganic compound surface-treated with hydrophobic silane, and an organic compound surface-treated with hydrophobic silane.
The method of claim 10, wherein the silicon binder comprises a silicon resin represented by the following Formula (1) and an organic diluent at a weight ratio of 50 to 90:10 to 50:

where R₁ to R₈ are respectively and independently selected from a group consisting of hydrogen, C₁ _-8 alkyl, C₆ _-10 aryl, and C₃ _-8 cycloalkyl, and n indicates an integer of from 1 to 100,000.
The method of claim 13, wherein the R₁ to R₈ are respectively and independently selected from a group consisting of methyl, ethyl, and phenyl.
The method of claim 13, wherein the organic diluent is one or more selected from a group consisting of xylene, ethylbenzene, alcohol and water.
The method of claim 10, wherein a weight ratio of the super absorbent polymer (SAP) to the water is in a range of 1:50 to 1:1000.
The method of claim 10, wherein a weight ratio of the super absorbent polymer (SAP) to the hydrophobic powder is in a range of 1:10 to 1:500.
The method of claim 10, wherein the silicon binder is contained in an amount of 50 to 150 parts by weight, based on 100 parts by weight of the total weight of the water, the super absorbent polymer (SAP) and the hydrophobic powder.
A heat-insulating element comprising:

a heat-insulating substrate; and

a heat insulation composition layer formed on the heat-insulating substrate using the heat-insulating composition of any one of claims 1 to 9.
The heat-insulating element of claim 19, wherein the heat-insulating substrate is formed using a material selected from a group consisting of a glass fiber, a silica fiber, mineral wool (rock wool), ceramic wool, a polymer fiber and a carbon fiber.