JPH0132063B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a synthetic resin laminated heat insulating material.

Synthetic resin insulation materials have been widely used as insulation materials near room temperature or at low temperatures. For example, they were attached to the walls, ceilings, or floors of houses to increase the efficiency of heating and cooling systems. It was also used to construct the walls, ceilings, and doors of cold storage warehouses to improve insulation.

A heat insulating material suitable for such uses is one made of synthetic resin foam. A synthetic resin foam is made by producing a large number of small bubbles in a molten synthetic resin so that the bubbles are independent. As the synthetic resin, styrene resin was preferably used. This is because it has compressive strength and is easy to install. Such a foam was cut into plates and supplied as plates of a constant thickness.

The inventor found that polystyrene foam boards have the disadvantage of being easily permeable to moisture, and that if they were used for building roofs, walls, etc., they would cause problems. For example, a polystyrene foam board is attached to the roof of a building overlapping a waterproof sheet, but when water droplets come into contact with it due to rain, water vapor permeates into the polystyrene foam board, reducing its insulation properties. Therefore, the inventor considered it necessary to improve these drawbacks. However, since water vapor permeability is based on the essence of polystyrene, and polystyrene has water vapor permeability several to ten times higher than polyolefins or polyvinyl chloride, it is difficult to improve it. it was thought.

Foam boards that have been supplied as insulation materials until now are
The majority consisted of foam only. In other words, there has been little effort to combine foam with other materials and process it into a structure suitable for use as a heat insulating material. However, the only processed materials available were a non-foamed film made of aluminum foil or synthetic resin pasted on the surface of a foam board. However, aluminum foil and non-foamed film are not as easy to adhere to as foam boards, so exposing them to the surface has the effect of reducing water vapor permeability, but attaching them with adhesive or It was inconvenient to combine with composite materials.

In the field of packaging films, laminated materials with various materials are made, but laminated materials have hardly been considered as insulation materials. it is,
This is because synthetic resin foam boards break easily, and when attempting to bond them, the bubbles are crushed by heat or solvent, making it difficult to bond them together properly.

The inventor attempted to improve the water vapor permeability of a polystyrene foam board by laminating the polystyrene foam board with other materials. As a result, a foamed film of a copolymer of ethylene and vinyl acetate was created, and when this film was softened or molten and bonded to polystyrene foam boards, the resulting laminate was firmly integrated without any bubble damage. It was confirmed that the water vapor permeability was improved and the overall strength was further improved. Furthermore, it has been confirmed that the above copolymer must contain 5 to 50% by weight of vinyl acetate. Furthermore, it was confirmed that a polymer mixture of a vinyl acetate polymer and an ethylene polymer may be used instead of the above copolymer. This invention was made based on such confirmation.

This invention relates to a copolymer of vinyl acetate and ethylene, or a copolymer of vinyl acetate and ethylene, having a composition in which vinyl acetate accounts for 5 to 50% by weight and ethylene accounts for 50 to 95% by weight. The present invention relates to a synthetic resin laminated heat insulating material in which a foamed film or sheet made of a mixture is softened or melted, interposed between foamed styrene resin sheets or boards, and fused to form a single body.

The synthetic resin laminated heat insulating material according to the present invention has a foamed sheet or board made of styrene resin placed on the surface, and a foamed film or sheet made of a copolymer or polymer mixture of vinyl acetate and ethylene between them. They are interposed and the whole is fused and integrated.

The foamed sheet or board of styrene resin used in this invention includes the following:
It is no different from the synthetic resin insulation materials that have been used up until now. This method involves pressurizing a foaming agent into a styrene resin, vaporizing or decomposing the foaming agent in the molten state of the styrene resin to generate gas, and thereby generating bubbles in the resin. Here, the term "sheet" refers to something that is relatively thin, and the term "board" refers to something that is relatively thick. The thickness can be within the range of 2 mm to 100 mm. The styrene resin is not limited to a styrene homopolymer, but may also be a copolymer thereof.

The expanded film or sheet used in this invention is a copolymer or polymer mixture of ethylene and vinyl acetate. In either the copolymer or polymer mixture, there is a preponderance of ethylene than vinyl acetate, with vinyl acetate accounting for 5 to 50% by weight, preferably 5 to 20% by weight, and ethylene accounting for 50 to 95% by weight. % preferably 80 to 95% by weight
This accounts for a large proportion of the total. Although it is preferred to use an extruder to make films or sheets from such polymers, calender rolls can also be used. Here, film refers to a relatively thin film with a thickness of 50 to 1000 microns, and sheet refers to a relatively thick film of 1 mm to 10 mm.
It means something.

In the laminated heat insulating material according to the present invention, the foamed film or sheet is sandwiched in the middle, and a foamed styrene resin sheet or board is placed on the surface. It is desirable that the styrene resin sheets or boards located on both sides have the same thickness;
They may have different thicknesses. Furthermore, it is desirable that the sheets or boards located on the surface have the same foaming ratio, but they may have slightly different foaming ratios. The sheet or board located on the surface is
It is preferable to have a skin layer on the surface, but it may not have a skin layer. The foaming ratio is 20 in terms of density.
to 50Kg/ ^m2 is preferable. Further, the bubbles are preferably fine, and preferably have a diameter of 0.2 to 2.0 mm.

An example of the laminated heat insulating material according to the present invention is shown in partially cutaway perspective views in FIGS. 1 and 2. Figures 1 and 2
In the figure, 1 to 3 are foamed styrene resin boards, 4 and 5 are their skin layers, and 6 and 7 are foamed films made of a copolymer of vinyl acetate and ethylene. The foamed styrene resin board may be present in three or more layers as shown in FIG.

In the laminated insulation material according to the present invention, the foam board 1
and 2 are fused and integrated by a foamed film 6. That is, the foamed film 6 spreads over the entire seam between the foamed boards 1 and 2, and since the foamed film 6 has unevenness on both sides, anchors are anchored here and there on the surfaces of the boards 1 and 2. As a result, they are firmly fused together. Therefore, this laminated insulation material will not be easily peeled off even if an attempt is made to peel it off to the boards 1 and 2.

To make the laminated heat insulating material of the present invention shown in FIG. 1, it is desirable to proceed as follows. First, two extruders are prepared and arranged approximately parallel to each other, and the first extruder produces a polystyrene foam board. Specifically, polystyrene is blended with a flame retardant, a cell control agent, and a coloring agent and fed to an extruder, and dichlorodifluoromethane and methyl chloride are mixed as blowing agents in a 1:1 weight ratio. A ratio of 10 parts by weight to 100 parts by weight of resin is mixed under pressure, and this mixture is supplied to a die at 120°C. Adjust the resin extruded from the nozzle to a thickness of 25 mm.
A foam with a skin layer having a width of 250 mm and a density of 40 Kg/m ² is obtained. This is called material A.

Subsequently, while producing material A as it was, an ethylene-vinyl acetate copolymer having a vinyl acetate content of about 10% by weight was fed to the second extruder. The copolymer is
100 parts by weight of Cellmic as a foaming agent.
1 part by weight of CAP500 is added. This copolymer has a width provided in the middle of the mouthpiece that makes material A.
It is extruded through a 60 micron thin film and expanded to approximately 4 times its size to form a foamed film approximately 200 microns thick. In this way, the resin extruded from the nozzles using the first and second extruders becomes a skin with a foamed film sandwiched in between, and the shape is adjusted to form a skin with a thickness of 25 mm, width of 250 mm, and density of 42 kg/ ^m2. It became a layered foam. This is called material B. Material B has a laminated structure in which a foamed copolymer film is sandwiched between material A and strongly adhered, and is a strong laminated body. This is the laminated heat insulating material according to the present invention. JIS Z 0208 moisture permeability of materials A and B
When measured according to , A is 0.28 g/m ² hr,
B was 0.16 g/m ² hr.

In the production method described above, a blowing agent is actively added to the copolymer, but when the film made from the copolymer is thin, the blowing agent is actively added to the copolymer. Even if it is not added, the foaming agent in the polystyrene may migrate and naturally foam the film.

In the laminated heat insulating material according to the present invention, the foamed film or sheet is interposed between the foamed styrene resin sheets or boards to form an integrated structure, so that what is exposed on both the front and back surfaces is the styrene resin sheet or board. It is. Therefore, secondary processing is easier than when a polyolefin film is attached to the surface. That is, it can be attached as it is by applying an adhesive such as asphalt to the surface, and plywood, plasterboard, cloth, etc. can be easily attached to the surface with adhesive.

In addition, in the laminated insulation material according to the present invention, vinyl acetate is used as the foamed film material.
By using a copolymer or polymer mixture having a composition of 50% by weight and 50 to 95% by weight of ethylene, it is possible to form a sheet or board of foamed styrenic resin without damaging the air bubbles in the sheet or board. Can be firmly fused. This fusion force is so strong that if you forcefully peel it off, pieces of foamed styrene resin will definitely stick to the entire surface of the foamed film. In addition, this laminated insulation material has a foamed film in the middle, which has a high ethylene content as mentioned above.
It has a high resistance to moisture permeation, therefore does not allow water vapor to pass through, and does not have the drawback of reducing heat insulation. in addition,
Since the foamed film has the above-mentioned composition and constitutes a soft film, the laminated heat insulating material itself is less likely to crack or break even when bent, and therefore less likely to be damaged. The laminated insulation material of this invention is
It brings such advantages and therefore has great practical value.

[Brief explanation of drawings]

1 and 2 are partially cutaway perspective views of a synthetic resin laminated heat insulating material according to the present invention. In the figure, 1 to 3 are foamed styrene resin sheets or boards, 4 and 5 are skin layers thereof, and 6 and 7 are foamed films or sheets.

Claims (1)

[Claims] 1 Consisting of a copolymer of vinyl acetate and ethylene, or a mixture of a vinyl acetate polymer and an ethylene polymer, with a composition in which vinyl acetate accounts for 5 to 50% by weight and ethylene accounts for 50 to 95% by weight. ,
A synthetic resin laminated heat insulating material in which a foamed film or sheet is softened or melted, interposed between foamed styrene resin sheets or boards, and fused to form a single piece.