Outer cover material for vacuum insulator and high-performance vacuum insulator comprising same
Provided is an outer cover material for a vacuum insulator, sequentially comprising: one or more layers of a polyester film; a polyvinyl alcohol (PVOH) film adhered to a lower surface of the polyester film; and a sealing film adhered to a lower surface of the PVOH film. Also provided is a vacuum insulator, comprising a core material consisting of a fiberglass; and the outer cover material under internal pressure, accommodating the core material.
1. An outer cover material for a vacuum insulator, the outer cover material sequentially comprising:
a first vacuum metalized poly ethylene terephthalate (VM-PET) film;
a second VM-PET film adhered to a lower surface of the first VM-PET film;
a polyvinyl alcohol (PVOH) film adhered to a lower surface of the second VM-PET film; and
a sealing film adhered to a lower surface of the PVOH film,
wherein
the sealing film is a casting polypropylene (CPP) film,
the first VM-PET film, second VM-PET film, PVOH film and CPP film are adhered by a polyurethane-based resin, respectively,
the first VM-PET film includes a first aluminum deposition layer over one surface of a first polyethylene terephthalate (PET) film,
the second VM-PET film includes a second aluminum deposition layer over one surface of a second PET film,
the first PET film is exposed to the exterior,
the first aluminum deposition layer is placed on the interior and between the first PET film and the second PET film,
the second PET film is placed between the first aluminum deposition layer and the second aluminum deposition layer,
the second aluminum deposition layer is placed between the second PET film and the PVOH film, and
the outer cover material is free from an aluminum foil,
wherein the PVOH film has a thickness of 10 μm to 30 μm, the CPP film has a thickness of 20 μm to 40 μm, and each of the first and second VM-PET film has a thickness of 5 μm to 20 μm,
wherein the optical density of the first and the second VM-PET film is not less than 3.0,
wherein the thickness of the first and the second aluminum deposition layer is not less than 500 Å, and
wherein the CCP film is thicker than the polyvinyl alcohol film, the polyvinyl alcohol film is thicker than each of the first and second VM-PET film.
2. The outer cover material according to claim 1 , wherein the PVOH film is a multi-layered PVOH film.
3. The outer cover material according to claim 1 , wherein the polyurethane-based resin has an interlayer adhesive strength of 200 gf/15 mm or more.
4. A vacuum insulator, the vacuum insulator comprising:
a core material consisting of a fiberglass; and
an outer cover material accommodating the core material, said outer cover material comprising,
a first vacuum metalized poly ethylene terephthalate (VM-PET) film,
a second VM-PET film adhered to a lower surface of the first VM-PET film,
a polyvinyl alcohol (PVOH) film adhered to a lower surface of the second VM-PET film, and
a sealing film adhered to a lower surface of the PVOH film,
wherein
the core material has a pore size of 50 μm or less,
the sealing film is a casting polypropylene (CPP) film,
the first VM-PET film, second VM-PET film, PVOH film and CPP film are adhered by a polyurethane-based resin, respectively,
the first VM-PET film includes a first aluminum deposition layer over one surface of a first poly ethylene terephthalate (PET) film,
the second VM-PET film includes a second aluminum deposition layer over one surface of a second PET film,
the first PET film is exposed to the exterior,
the first aluminum deposition layer is placed on the interior and between the first PET film and the second PET film,
the second PET film is placed between the first aluminum deposition layer and the second aluminum deposition layer,
the second aluminum deposition layer is placed between the second PET film and the PVOH film, and
the outer cover material is free from an aluminum foil,
wherein the PVOH film has a thickness of 10 μm to 30 μm, the CPP film has a thickness of 20 μm to 40 μm, and each of the first and second VM-PET film has a thickness of 5 μm to 20 μm,
wherein the optical density of the first and the second VM-PET film is not less than 3.0,
wherein the thickness of the first and the second aluminum deposition layer is not less than 500 Å, wherein the CCP film is thicker than the polyvinyl alcohol film, the polyvinyl alcohol film is thicker than each of the first and second VM-PET film.
5. The vacuum insulator according to claim 4 , wherein the core material is a laminate having multi-layered board comprising the fiberglass.
6. The vacuum insulator according to claim 4 , further comprising a getter material attached to or inserted into the core material.
7. The vacuum insulator according to claim 4 , wherein the PVOH film is a multi-layered PVOH film.
8. The vacuum insulator according to claim 4 , wherein the polyurethane-based resin has an interlayer adhesive strength of 200 gf/15 mm or more.