KR102335441B1 - Envelope having flame retardant for vacuum insulation panel and vacuum insulation panel having the same - Google Patents

Abstract

The present invention relates to an envelope for a vacuum insulating material and a vacuum insulating material using the same. The envelope for vacuum insulation according to the present invention has excellent flame retardant performance including a laminated structure of a flame-retardant coating layer containing airgel from the outside, a protective layer, and an adhesive layer.

Description

Outer sheath material for vacuum insulation having flame retardancy and vacuum insulation including the same

The present invention relates to a vacuum insulation material having excellent flame retardancy and a vacuum insulation material comprising the same.

Vacuum insulators are used as high-efficiency next-generation insulators because they have a thermal conductivity that is 8 times lower than that of general insulators.

In such a vacuum insulator, the envelope for the vacuum insulator is exposed to external impacts and external environmental changes, and in particular, the vacuum insulation envelope is deteriorated due to a high temperature, so there is a problem in that the performance of the vacuum insulator is reduced.

It is an object of the present invention to provide an outer skin material for a vacuum insulation material having excellent flame retardancy and a vacuum insulation material using the same.

However, the technical problem to be achieved by the present invention is not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

The envelope for vacuum insulation according to an embodiment of the present invention includes a laminated structure of a flame-retardant coating layer containing airgel from the outside, a protective layer, and an adhesive layer.

In addition, the flame-retardant coating layer may be formed from a composition comprising 70 to 97% by weight of silicate, 1 to 20% by weight of airgel, 1 to 5% by weight of filler and 1 to 5% by weight of additives.

A vacuum insulation material according to another embodiment of the present invention includes a core material and a shell material covering the core material, and the shell material includes a laminated structure of a flame-retardant coating layer containing airgel from the outside, a protective layer and an adhesive layer.

Since the envelope for vacuum insulation according to the present invention has a flame-retardant coating layer containing airgel, it has excellent flame retardant performance compared to the existing envelope for vacuum insulation.

Effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

Advantages and features of the present invention, and a method of achieving them will become clear with reference to the following examples. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, Only the present embodiments are provided to complete the disclosure of the present invention, and to fully inform those of ordinary skill in the art to which the present invention belongs, the scope of the invention, the present invention is defined by the scope of the claims will only be

For vacuum insulation cover material

The envelope for vacuum insulation according to the present invention includes a laminated structure of a flame-retardant coating layer containing airgel from the outside, a protective layer and an adhesive layer.

Hereinafter, each configuration of the envelope for vacuum insulation according to the present invention will be described in detail.

flame retardant coating layer

The envelope for vacuum insulation according to the present invention includes a flame-retardant coating layer containing airgel on the outermost shell.

The flame-retardant coating layer according to the present invention imparts flame-retardant performance to a vacuum insulation material and a vacuum insulation material using the same.

Although the method of forming the flame-retardant coating layer is not particularly limited, it is preferably formed in the form of a coating layer on the outermost surface of the outer shell material using a coating solution containing airgel.

The flame-retardant coating layer according to the present invention may be formed of a composition basically including silicate, airgel, fillers and additives, and in the composition, 70 to 97% by weight of silicate, 1 to 20% by weight of airgel, functional filler 1 to 5% by weight and 1 to 5% by weight of additives may be added. Considering that the flame-retardant coating layer is formed on the outermost layer of the vacuum insulation material, the composition preferably contains 70 to 87% by weight of silicate, 10 to 20% by weight of airgel, 1 to 5% by weight of filler and additives It may be added in a proportion of 1 to 5% by weight, and more preferably 70 to 83% by weight of silicate, 15 to 20% by weight of airgel, 1 to 5% by weight of filler and 1 to 5% by weight of additives. have.

The silicate expands and expands in case of fire and may be added to the flame-retardant coating layer for reasons of absorbing heat. When the silicate is added in an amount of less than 70% by weight, there is a problem in that the flame retardancy of the coating layer is deteriorated, and when it is added in excess of 97% by weight, there is a problem in that the workability during coating is poor.

The airgel is a highly porous material and has very low thermal conductivity and may be added to the flame-retardant coating layer for the reason of lowering the thermal conductivity of the flame-retardant coating layer. When the airgel is added in an amount of less than 1% by weight, there is a problem that the thermal barrier effect is insufficient, and when it is added in excess of 20% by weight, there is a problem in that the layer separation occurs due to hydrophobicity.

Preferably, in order to improve both the thermal insulation and flame retardant performance of the vacuum insulation and to uniformly coat the flame retardant coating layer on the outermost surface of the outer shell, the composition for forming the flame retardant coating layer is 70 to 87% by weight of silicate, 10 to 20% by weight of airgel %, and most preferably 70 to 83% by weight of silicate, and 15 to 20% by weight of airgel.

The airgel may use a silica airgel powder having a size in the range of 0.1 μm to 100 μm. As an example, the airgel may be an amorphous silica airgel powder. The amorphous silica airgel powder preferably uses hydrophobicity, but hydrophilicity may be used. Silica airgel powder is generally made from water glass or alkoxide such as TEOS (Tetra Ethyl Ortho Silicate) and TMOS (Tetra Methyl Ortho Silicate) as a raw material and manufactured according to airgel synthesis processes such as supercritical drying and atmospheric pressure drying. it is preferable

The filler may be included in the flame-retardant coating layer to improve heat resistance. The filler may be in the form of silica, that is, one of fumed silica, colloidal silica, and micronized silica. In addition to the filler, expandable graphite or expandable graphite mixed with at least one of magnesium/calcium carbonate, calcium carbonate, and aluminum hydroxide may be used.

In addition, the flame-retardant coating layer according to the present invention may use a leveling agent as an additive in some cases. As a surface conditioning agent, polyalkyl acrylate, polyalkyl vinyl ether, cellulose acetate butylate (CAB), dimethyl polysiloxane (de-methyl polysiloxane), methyl phenyl polysiloxane (methyl phenyl) polysiloxane), organic modified polysiloxane, and one of fluorine-based surfactants may be used.

Since the silicate is hydrophilic, it is preferable to add a surfactant as an additive in order to add a hydrophobic airgel.

protective layer

Next, the envelope for vacuum insulation according to the present invention includes a protective layer.

The protective layer corresponds to a layer formed under the outermost flame-retardant coating layer. When the protective layer includes a metal barrier layer thereon, it serves to increase the flame retardancy, and when the protective layer includes a metal barrier layer under the protective layer, it can serve to increase the barrier properties of the vacuum insulation envelope itself. .

The protective layer may include at least one of polyethylene terephthalate, a nylon film, and a combination thereof. As an example, the protective layer may be formed in a laminate structure of a polyethylene terephthalate (PET) film having a thickness of about 10 μm to about 25 μm and a nylon film having a thickness of about 15 μm to about 25 μm.

In addition, when the metal barrier layer is formed under the protective layer, the degree of cracks occurring in the metal barrier layer is severe and damage may be applied to the polyethylene terephthalate/nylon film. In order to prevent this, the polyethylene A vinyl-based resin may be coated on the terephthalate film to be used.

Specifically, the vinyl-based resin is made of polyvinyl chloride (PVC), polyvinyl acetate (PVA), polyvinyl alcohol (PVAL), polyvinylbutalal (PVB), polyvinylidene chloride (PVDC), and combinations thereof. It may be one or more selected from the group.

The metal barrier layer may be specifically formed of a metal thin film having a thickness of about 5 μm to about 10 μm, and preferably formed of a material including aluminum foil.

adhesive layer

The adhesive layer is a layer that is thermally welded to each other by heat sealing, and functions to maintain a vacuum state. The adhesive layer is easily heat-welded high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), unstretched polypropylene (CPP), stretched polypropylene (OPP), polyvinylidene chloride (PVDC), Formed with a thermoplastic plastic film comprising at least one selected from the group consisting of polyvinyl chloride (PVC), ethylene-vinyl acetate copolymer (EVA), ethylene-vinyl alcohol copolymer (EVOH), and combinations thereof, but with sufficient sealing It may be formed to a thickness of about 50 μm to about 80 μm to provide properties.

The adhesive layer may further include calcium oxide as needed. Calcium oxide has the function of a desiccant to adsorb moisture and the like. The vacuum insulation material contains calcium oxide in the outer skin material to very effectively block moisture from penetrating from the outside, thereby improving long-term durability. Specifically, the adhesive layer includes a heat-welded portion, and moisture penetration through the heat-welded portion can be more effectively suppressed.

Additionally, since the calcium oxide included in the adhesive layer is in contact with the core material of the vacuum insulating material, it may also react with moisture remaining inside the core material to further lower the degree of vacuum inside the core material.

The calcium oxide may be dispersed and included in the thermoplastic plastic film forming the adhesive layer, and for example, a composition obtained by mixing a thermoplastic resin and quicklime powder may be extruded to form a film to form an adhesive layer.

The calcium oxide may be included in an amount of about 30 to about 40 wt% of the adhesive layer. The vacuum insulating material including the adhesive layer containing calcium oxide in the content in the above range has an excellent vacuum maintaining effect, and has the advantage of being able to react to residual moisture inside and moisture penetrating from the outside. However, if it is more than 40% by weight, it does not act as an adhesive layer due to a decrease in adhesive strength.

Specifically, as the calcium oxide, quicklime having an average particle diameter of about 0.1 μm to about 10 μm may be used.

In addition, in order to further improve the airtight properties of the outer skin material, the protective layer, the adhesive layer, and other additional layers may be adhered to each other using a polyurethane (PU)-based resin.

In this way, by forming the envelope for a vacuum insulation material including the flame-retardant coating layer, the protective layer and the adhesive layer, the barrier performance of the envelope material is strengthened, the cracking due to external impact, in particular, the flame retardancy problem of the surface of the envelope material can be improved.

vacuum insulation

The vacuum insulation material according to the present invention includes a core material and a shell material covering the core material, and the shell material includes a laminated structure of a flame-retardant coating layer containing airgel from the outside, a protective layer, and an adhesive layer.

As the core material, a commonly known material may be used as a core material of a vacuum insulator, and specifically, glass fiber, fumed silica, silica board, glass board, organic fiber (organic fiber), organic foam (organic foam), and may include at least one selected from the group consisting of combinations thereof.

As described in detail above, the outer shell material has a multi-layered thin film structure including a laminated structure of a flame retardant coating layer, a protective layer, and an adhesive layer, and the adhesive layer is thermally welded to seal the core material.

The core material is sealed with an envelope material and reduced pressure to exhibit a vacuum insulation effect. The internal pressure of the shell material, that is, the vacuum degree inside the sealed vacuum insulating material may be about 10 to about 30 Pa.

The adhesive layer may directly coat the core material, may be formed by heat welding by heat sealing, and perform a function of maintaining a vacuum state of the core material. Therefore, as mentioned above, the adhesive layer may be formed of a thermoplastic plastic film that is easily heat-sealed.

The vacuum insulator may further include a getter in addition to containing calcium oxide as a moisture absorbent in the adhesive layer of the outer cover material, and additionally a getter to absorb gas and moisture that may be generated inside the outer cover material, and the getter is known materials can be used without limitation. The getter may be inserted into the core member or disposed between the core member and the envelope member.

The getter may be quicklime (CaO) contained in a pouch. For the quicklime, about 95% or more of quicklime powder may be used, and the pouch may be formed of corrugated paper and polypropylene (PP) impregnated nonwoven fabric.

Hereinafter, Examples and Comparative Examples of the present invention will be described. The following examples are only examples of the present invention, but the present invention is not limited to the following examples.

< Example and comparative example >

Example One

Al foil 6㎛, polyvinylidene chloride (PVDC)/polyethylene terephthalate film (PET) 12.5㎛ and nylon (Nylon) film 25㎛ are laminated on a linear low density polyethylene (LLDPE) film having a thickness of 50㎛ to prepare an outer skin material did

Thereafter, a flame-retardant coating layer was formed on the outermost surface of the outer shell material in the following manner.

i) Preparation of a composition for forming a flame retardant coating layer

After adding 15% by weight of silica airgel powder having an average size of 40㎛ to 87% by weight of alkali metal silicate resin, 4% by weight of filler (fumed silica) and 4% by weight of additives (alkyl polyacrylate, surfactant), 1000rpm for about 30 minutes A composition for forming a flame retardant coating layer was prepared by stirring and dispersing at a speed of

ii) Manufacture of outer skin material with flame retardant coating layer

The composition was coated on the outermost layer of the envelope, cured/dried, and finally a flame-retardant coating layer was formed to prepare an envelope.

A glass wool type core material was coated using the outer skin material having the flame retardant coating layer formed thereon to prepare a vacuum insulation material. Thereafter, the vacuum insulator was heat-treated in a vacuum chamber while maintaining a vacuum of 10 Pa. By the heat treatment, the linear low-density polyethylene (LLDPE) film was heat-sealed, and thus a vacuum insulation material according to Example 1 was finally prepared.

Example 2

A vacuum insulation material was prepared under the same conditions as in Example 1, but a vacuum insulation material in which a core material was made of a glass board was prepared.

comparative example One

A vacuum insulation material was prepared under the same conditions as in Example 1, but a vacuum insulation material using an outer skin material without a flame retardant coating layer was prepared.

comparative example 2

A vacuum insulation material was prepared under the same conditions as in Example 2, but a vacuum insulation material using an outer skin material without a flame retardant coating layer was prepared.

< Experimental example >

Flame Retardant Test

i) UL 94-HB test

The vacuum insulation materials of Examples 1 to 3 and Comparative Examples 1 to 2 were evaluated for flame retardancy by the HB method in accordance with UL 94 International Flame Retardant Standard Certification.

The test was carried out by drawing a line on the 25 and 100 mm portions of the test piece, laying the test piece in a horizontal direction, and applying a test flame to the test piece at an angle of 45° for 30 seconds. The burning rate is calculated by measuring the time from when the flame starts passing through the 25mm section until it reaches the 100mm section.

[Table 1]

UL 94-HB test results for Examples 1 and 2 and Comparative Examples 1 and 2 are summarized in Table 1 above. Referring to Table 1, Examples 1 to 3 did not burn up to 25 mm in the horizontal direction even when a flame was applied for 30 seconds. That is, the combustion rate of the vacuum insulator according to Examples 1 and 2 is 0.

On the other hand, the vacuum insulation material according to Comparative Examples 1 and 2 continued combustion, so that the burned horizontal length was 69, 70 mm, and the total burned time was measured to be 74, 76 seconds. When the combustion rate is measured through the combustion time and the combustion horizontal length in the 25 mm portion or more, Comparative Example 1 corresponds to 77.6 mm/min and Comparative Example 2 corresponds to 77.14 mm/min.

The UL 94-HB test certification burn rate criterion for a test piece having a thickness of less than 3 mm is less than 75 mm/min, and Examples 1 and 2 satisfy the above criteria, but Comparative Examples 1 and 2 are certified according to UL 94-HB It can be seen that the criteria are not met.

That is, although the vacuum insulating material according to Examples 1 to 3 was a thin film having a thickness of less than 3 mm, it was confirmed that the flame retardancy was very excellent due to the flame retardant coating layer formed on the outer shell material.

ii) UL 94-V test

In addition, flame retardancy was evaluated through the UL 94-V test for the vacuum insulators of Examples 1 and 2 and Comparative Examples 1 and 2.

In this test, the Example and Comparative Example having a thickness of 1 mm were manufactured to evaluate the flame retardancy.

In the UL 94-V test, the test piece is erected vertically, a flame is applied to the end of the test piece for 10 seconds, and the combustion time (T1) of the test piece is measured. It was carried out in such a way as to measure the time (T2) at which combustion ends.

[Table 2]

UL 94-V test results for Examples 1 and 2 and Comparative Examples 1 and 2 are summarized in Table 2 above. Referring to Table 2, in Examples 1 and 2, the combined combustion time of T1 and T2 corresponds to less than 30 seconds, and the total combustion time is short compared to 41 and 54 seconds, which are the combustion times (T1 + T2) of the comparative example. became That is, it can be seen that the Example having the outer shell material with the flame-retardant coating layer has a shorter combustion time than the Comparative Example, so that the flame retardancy is excellent.

Through this flame-retardant test, it was confirmed that Examples 1 and 2 had very excellent flame retardancy compared to the conventional vacuum insulator due to the flame-retardant coating layer formed on the top of the outer shell material.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, but may be manufactured in a variety of different forms, and those of ordinary skill in the art to which the present invention pertains will appreciate the technical spirit of the present invention. However, it will be understood that the invention may be embodied in other specific forms without changing essential features. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

Claims (13)

from outside,
Including a laminated structure of a flame-retardant coating layer, a protective layer and an adhesive layer containing airgel,
The flame-retardant coating layer is
Silicate 70-83% by weight,
Airgel 15-20 wt%,
1 to 5% by weight of filler and
Formed from a composition comprising 1 to 5% by weight of an additive,
The airgel comprises silica airgel powder,
The filler includes at least one of fumed silica, colloidal silica, micronized silica, expandable graphite, and at least one of magnesium/calcium carbonate, calcium carbonate, and aluminum hydroxide mixed with the expandable graphite,
The additive is polyalkyl acrylate, polyalkyl vinyl ether, cellulose acetate butylate (CAB), dimethyl polysiloxane (de-methyl polysiloxane), methyl phenyl polysiloxane (methyl phenyl polysiloxane) , containing at least one of organic modified polysiloxane and fluorine-based surfactants
Outer sheath material for vacuum insulation.
delete According to claim 1,
The airgel is
Silica airgel powder having a size of 0.1 μm to 100 μm
Outer sheath material for vacuum insulation.
delete According to claim 1,
Further comprising a metal barrier layer on the upper or lower portion of the protective layer
Outer sheath material for vacuum insulation.
According to claim 1,
The protective layer is
At least one of polyethylene terephthalate, nylon film, and combinations thereof
Outer sheath material for vacuum insulation.
7. The method of claim 6,
A vinyl-based resin is coated on the polyethylene terephthalate film
Outer sheath material for vacuum insulation.
8. The method of claim 7,
The vinyl-based resin is
At least one selected from the group consisting of polyvinyl chloride (PVC), polyvinyl acetate (PVA), polyvinyl alcohol (PVAL), polyvinyl butalal (PVB), polyvinylidene chloride (PVDC), and combinations thereof
Outer sheath material for vacuum insulation.
6. The method of claim 5,
The metal barrier layer comprises an aluminum foil (Foil)
Outer sheath material for vacuum insulation.
It includes a core material and a shell material covering the core material,
The skin material is
From the outside, it includes a laminated structure of a flame-retardant coating layer containing airgel, a protective layer and an adhesive layer,
The flame-retardant coating layer is
Silicate 70-83% by weight,
Airgel 15-20 wt%,
1 to 5% by weight of filler and
Formed from a composition comprising 1 to 5% by weight of an additive,
The airgel comprises silica airgel powder,
The filler includes at least one of fumed silica, colloidal silica, micronized silica, expandable graphite, and at least one of magnesium/calcium carbonate, calcium carbonate, and aluminum hydroxide mixed with the expandable graphite,
The additive is polyalkyl acrylate, polyalkyl vinyl ether, cellulose acetate butylate (CAB), dimethyl polysiloxane (de-methyl polysiloxane), methyl phenyl polysiloxane (methyl phenyl polysiloxane) , containing at least one of organic modified polysiloxane and fluorine-based surfactants
vacuum insulation.
delete 11. The method of claim 10,
The airgel is
Silica airgel powder having a size of 0.1 μm to 100 μm
vacuum insulation.
delete