JPH0110197Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a composite plate for cold storage.

BACKGROUND ART Various foam materials, especially urethane foam, have been developed as cold insulation materials for LPG tanks in vessels for transporting liquefied petroleum gas (LPG) (hereinafter referred to as LPG ships).

Typically, LPG ships use an external heat insulation method in which an independent tank (spherical or square) is installed inside the tank, and a cold insulation material is installed on the outside of the tank.

Looking at the cold insulation materials used for these, at least one type of urethane foam, especially LPG
Composite boards with a reinforcing layer of glass wool, paper, nonwoven fabric, woven fabric, knitted fabric, etc. on the side are attracting attention. This composite board usually absorbs moisture in the reinforcing layer during the manufacturing process and storage (this causes cold retention value, freeze cracking)
To prevent this, it is laminated with a moisture-impermeable layer such as polyethylene film.

When the above-mentioned cold insulation material is used in an LPG ship, there is a risk that welding sparks may ignite or damage the external urethane foam. In order to solve this problem, the present inventors tried a method of laminating iron foil on the outer layer of the cold insulation material, but laminating iron foil directly on the urethane foam layer would cause wrinkles and warping.
This is unfavorable in terms of appearance and also reduces strength.

The present invention solves the above-mentioned problems and provides a composite plate for cold storage for LPG ships that has no risk of ignition during welding work and has a beautiful appearance without warping or wrinkles.

That is, the present invention includes an iron foil layer 1 obtained by an air casting method, a moisture-impermeable synthetic resin layer 2, a reinforcing layer 3,
The moisture-impermeable synthetic resin layer 4, the polyurethane foam layer 5, the moisture-impermeable synthetic resin layer 6, the reinforcing layer 3', and the moisture-impermeable synthetic resin layer 7 are laminated in this order, and the iron foil layer 1 has a thickness of 10 to 100 μm. The present invention relates to a cold-insulating composite board made of iron foil obtained by electroforming, and whose reinforcing layers 3 and 3' are made of liner paper.

The iron foil layer 1 used in this invention has a thickness of 10μ or more.
100μ, preferably 40 to 50μ. If it is thinner than 10 μm, it will not be able to withstand sparks during welding for ship construction, and if it is 100 μm or more, the weight of the composite plate will increase and it will also be expensive, which is undesirable. Also, during production, it is difficult to produce iron foil laminated paper that is too thick. For the iron foil layer 1, it is preferable to use iron foil obtained by electroforming. Since the iron foil produced by electroforming has no rolling oil attached to its surface, the moisture-impermeable resin layer 2 adheres to the surface of the iron foil. Therefore, the adhesion between the iron foil layer 1 and the reinforcing layer 3 becomes strong. If aluminum foil or the like is used instead of iron foil, it will lack resistance to welding sparks, etc., and the foil will need to have a thickness of 100μ or more, making it expensive.

Moisture-impermeable synthetic resin layer 2 includes reinforcing layer 3 and iron foil layer 1
It is used to adhere the reinforcing layer 3 and to prevent moisture absorption during storage. Moisture-impermeable synthetic resin layer 2
Polyethylene film, polypropylene film, polyvinyl chloride film, polyvinylidene film, polystyrene film, polyester film, etc. can be used, but polyethylene film has a very low water vapor permeability and high low temperature strength, and can be obtained at a relatively low price. This is particularly preferred. Although polypropylene film has a lower water vapor permeability than polyethylene film, it has poor thermal adhesion and tends to become brittle at low temperatures. Polyvinyl chloride film is inferior in performance to polyethylene film in that it has a high water vapor permeability. Polystyrene film has a water vapor permeability several times higher than polyethylene and has a strong tendency to shrink during heat bonding, making it difficult to heat bond. However, products with no practical problems can be obtained using any of these synthetic resin films. The thickness of the moisture-impermeable synthetic resin layer 2 is from 20
30μ is appropriate.

The reinforcing layer 3 may be arbitrarily selected from paper, glass wool, nonwoven fabric, woven fabric, and the like. This is provided to prevent warping and wrinkles of the foil that would occur when the polyurethane foam layer 5 is directly bonded to the iron foil layer 1. The most preferred reinforcing layer is liner paper, which is a base paper for corrugated cardboard, which is inexpensive and has an excellent reinforcing effect.

For the moisture-impermeable synthetic resin layer 4, a synthetic resin film similar to that used for the moisture-impermeable synthetic resin layer 2 described above may be used. Iron foil laminated paper, that is, an iron foil laminated paper consisting of an iron foil layer 1, a moisture-impermeable synthetic resin layer 2, a reinforcing layer 3, and a moisture-impermeable synthetic resin layer 4, first has a moisture-impermeable synthetic resin layer 2, a reinforcing layer 3, It is manufactured by fusing a laminated paper consisting of a moisture-impermeable synthetic resin layer 4 and an iron foil, but in this case, the moisture-impermeable synthetic resin layer 4 is stored during storage of the laminated paper and before being bonded to the polyurethane foam 5. This is necessary to prevent the reinforcing layer 3 from absorbing moisture during this period. In a particularly preferred embodiment, the synthetic resins of layer 2 and layer 4 are of the same quality. This is the above 2, 3 and 4
This is to make the elongation and contraction of the front and back sides of the laminated paper the same and to prevent curling. A particularly preferred synthetic resin is polyethylene film, and the appropriate film thickness is 20 to 30μ.

The polyurethane foam layer 5 is manufactured from, for example, polymeric polyisocyanate (crude MDI), polyether polyol, foaming agent (Freon-11), foam stabilizer (silicone type), and amine catalyst, and the foaming ratio is 30 times to 40 times is preferable. The thickness of the foam layer is preferably 50 mm to 150 mm.

The laminated paper on the LPG side preferably has the same structure as the aforementioned laminated paper. In particular, it is preferable to use a reinforcing layer of the same quality in order to make the shrinkage rates of both laminate papers similar. Therefore, the moisture-impermeable synthetic resin layer 6, the reinforcing layer 3', and the moisture-impermeable synthetic resin layer 7 may be selected from the same materials as described above.

The cold insulation composite board of the present invention can be manufactured by a continuous manufacturing method in which a urethane foaming material is placed on iron foil laminated paper, and while this is foamed on a belt conveyor, an LPG side laminated paper is laminated thereon. Although urethane may be foamed on the LPG side laminated paper, it is preferable to foam it on the iron laminated paper in order to finish the surface of the iron laminated paper beautifully.

The cold insulation composite plate of the present invention may be coated with a polyester resin or the like on the iron foil side, or may be surface-laminated with a suitable synthetic resin film on the iron foil in advance. Suitable synthetic resins include polyethylene,
Polypropylene, polyvinyl chloride, polyvinylidene, polystyrene and polyester, etc.
Particularly preferred is polyethylene film, and the film thickness may be from 20 to 30μ. These surface coatings or surface laminates are extremely effective in preventing rust on iron foil. This aspect is also included within the technical scope of the present invention.

The cold insulation composite plate of the present invention has iron foil on the surface, which completely blocks moisture absorption, has very high surface fireproofing performance, and has high bending strength. Therefore LPG
Very suitable as a cold insulation material for ships.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of the cold-insulating composite plate of the present invention. In the figure, 1 is the iron foil layer, 2, 4, 6 and 7
3 and 3' are reinforcing layers, and 5 is a polyurethane foam layer.

Claims (1)

[Claims for Utility Model Registration] 1 Iron foil layer 1 obtained by electroforming, moisture-impermeable synthetic resin layer 2, reinforcing layer 3, moisture-impermeable synthetic resin layer 4, polyurethane foam layer 5, moisture-impermeable synthetic The resin layer 6, the reinforcing layer 3', and the moisture-impermeable synthetic resin layer 7 are laminated in this order, and the iron foil layer 1 has a thickness of
A composite plate for cold storage, consisting of iron foil obtained by electroforming with a thickness of 10 to 100 μm, and reinforcing layers 3 and 3' consisting of liner paper. 2. The cold-retaining composite board according to item 1, wherein the moisture-permeable synthetic resin layers 2, 4, 6, and 7 are made of the same material. 3. The first layer in which the moisture-impermeable synthetic resin layer is made of polyethylene.
Composite board for cold storage as described in section.