JPH0337502B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laminated body for laminated windows, and more particularly to a laminated body for laminated windows having a good appearance and having a transparent film interposed between two thermoplastic resin layers. The present invention relates to a laminated body for laminated windows that is provided with new functions by providing functionality.

BACKGROUND OF THE INVENTION Laminated glass windows are used for transparent openings that require safety, such as windows of automobiles, trains, airplanes, etc., or some building windows. The basic structure of a laminated window is that a thermoplastic resin layer is sandwiched between transparent bodies such as glass plates, but a film is further interposed in order to provide further functionality to the laminated window. For example, a method that uses a transparent film with excellent mechanical strength to prevent scattering, a method that uses a transparent conductive film to prevent condensation, or a method that allows visible light to pass through but makes it difficult for near-infrared rays to pass through. A method has been proposed in which a film with a light selective transmittance function is interposed.

However, a laminated window with a film interposed therebetween with a good appearance could not be obtained unless the film thickness was about 130 μm or more.

As the thickness of the film is reduced, the transparency of the laminated window is good, but when looking at the image reflected from the surface of the laminated window, the image becomes finely uneven and the image itself appears distorted, making it impractical for practical use. was something that could not be provided. On the other hand, there is generally a method of applying thin film processing to the surface of the film in order to impart functionality to the surface of the film, but this thin film processing is often done in a vacuum container, improving processability and productivity (e.g. continuous production ), the thinner the film, the better.

Therefore, it is suitable for the above-mentioned thin film processing, for example, 25μ.
If a laminated window with a good appearance can be manufactured using a film with a film thickness as thin as 0.0 m, it will be possible to obtain laminated windows with various functions.

To make laminated windows, the thermoplastic resin is typically formed into a sheet, which is embossed on both sides. By embossing, when laminating with a transparent plate, air existing between the two layers can be easily removed, and the embossed surface disappears by heat treatment, resulting in a laminated window with a good appearance. .

However, in a laminated window with a film interposed, if the film thickness is 130 μm or less, a good appearance cannot be obtained even with the above-mentioned measures.
Further improvements were desired.

As a result of intensive research to achieve this objective, the present inventors have found that the area of contact between the surface of the thermoplastic resin and the surface of the film affects the uniformity of appearance. That is, there is a tendency that the larger the non-embossed uniform surface, ie, the area in contact with the film, the better. When the film thickness is 130 μm or more, a good film can be obtained regardless of the presence or absence of embossing, that is, regardless of the size of the contact area. However, when the thickness of the film becomes thin, the appearance becomes poor when an embossed thermoplastic resin is used. Therefore, it is necessary to make the surface of the thermoplastic resin uniform. That is,
By doing so, the area of substantial contact with the film surface can be increased, and a laminated window with a good appearance can be obtained.

In addition, in order to facilitate the removal of air at the interface between the thermoplastic resin layer and the film, the thermoplastic resin layer,
It is preferable to laminate the film or thermoplastic resin layer while pushing out air using a roller or the like.

On the other hand, the thermoplastic resin surface in contact with the transparent plate can be embossed to facilitate air extraction.

That is, the present invention provides a laminate in which a thermoplastic resin layer is laminated on both sides of a film processed into a thin film having transparent conductivity or a thin film processing having selective light transmission, in which the film thickness of the film is less than 130 μm,
The laminated body is characterized in that the two thermoplastic resin layers are thermoplastic resin layers whose surface in contact with the film has a uniform surface and whose other surface is embossed.

Each component will be explained in detail below.

The thermoplastic resin is preferably one that has appropriate adhesive strength to the transparent plate, good transparency, and sufficient softness at the laminate processing temperature, such as polyvinyl butyral resin, styrene butadiene rubber, nitrile butadiene rubber, Neoprene, polyisoprene, butyl rubber, chlorinated rubber, polyisobutylene, polyacrylic ester, polyvinyl acetate,
Examples include polyvinyl ether, polyvinyl chloride, polyethylene propylene copolymer, polyester copolymer, and the like. When the transparent plate is a glass plate, polyvinyl butyral is preferred.

The surface of the thermoplastic resin layer that is in contact with the film surface is uniform, and the other surface is embossed.

The transparent film of the present invention has been subjected to a thin film process that imparts functionality. Examples of the material of the film include polyethylene terephthalate resin, polyvinyl alcohol, polypropylene, polyethylene, polyvinyl chloride resin, polybutylene terephthalate resin, polycarbonate resin, acrylic resin, polyamide resin, and other resins.

Examples of agents that impart functionality to films include imparting transparent conductivity, such as thin films made of indium oxide and tin oxide, thin films of tin oxide,
Examples include laminations of thin films of metals such as gold, silver, copper, and aluminum. In addition, as a functional agent that imparts selective light transmittance that makes it difficult for invisible heat rays of solar energy to pass through, thin films of metals such as gold, silver, copper, aluminum, nickel, palladium, tin, and alloys or mixtures thereof, Alternatively, a dielectric material may be laminated on one or both sides of this metal thin film. Examples of the dielectric include titanium oxide, behemoth oxide, zinc sulfide, tungsten oxide, indium oxide, zirconium oxide, silicon oxide, and the like.

The present invention will be specifically explained below using Examples.

Example 1 A film of indium oxide and tin oxide was provided on a biaxially stretched polyethylene terephthalate film (thickness: 50 μm). Film formation was performed using Ar/O ₂ (O ₂ ; 2%) as a target of In ₂ O ₃ /SnO ₂ (SnO ₂ is 5wt% of the total).
A film with a thickness of about 500 Å was obtained by RF sputtering with a mixed gas of 2 × 10 ^-3 Torr under vacuum.

The film had a transparent electrically conductive function. A thermoplastic resin sheet containing polyvinyl butyral as a main component and having a thickness of 380 μm and completely flattened on one side was laminated on both surfaces of the film using a laminator, with the flattened surface aligned with the surface of the film.

Glass plates with a thickness of 2 mm were further laminated on both sides of the obtained laminate. At this time, the thermoplastic resin sheet on the glass side is embossed.

After laminating the glass plates, the laminate was placed in a rubber bag that could wrap the entire laminate. The rubber bag is completely sealed except for a pipe to remove any remaining air inside. The rubber bag containing the laminate was placed in an autoclave, air was removed from the pipe, and a pressure of about 2 kg/cm ² was applied around the rubber bag.

After leaving it for about 5 minutes, the temperature was raised to 90° C. while maintaining the vacuum inside the rubber bag, and preliminary bonding was performed for about 30 minutes. Thereafter, the rubber bag was taken out of the autoclave, and only the laminate was put back into the autoclave, and main adhesion was performed at a pressure of 14 kg/cm ² and a temperature of 120° C. for about 30 minutes. Thereafter, the temperature was lowered to room temperature, the pressure was released, and the laminated window sample was taken out and had a good appearance and no irregularities.

Examples 2 and 3 Laminated window samples were prepared in the same manner as in Example 1, except that biaxially stretched polyethylene terephthalate films having a thickness of 25 μm and a thickness of 125 μm were used.

The appearance of the obtained laminated window samples was good.

Comparative Example 1 A laminated window sample was prepared in the same manner as in Example 1, except that a biaxially stretched polyethylene terephthalate film with a thickness of 25 μm was used, and a thermoplastic resin sheet with both sides embossed was used. Created.

Although the obtained laminated window sample had good transparency, the reflected image had irregularities and did not have a good appearance.

Comparative Example 2 Out of two thermoplastic resin sheets, only one sheet is flattened uniformly on one side with no irregularities, and the sheets are laminated so that the flattened surface matches the surface of the film as well. A laminated window sample was prepared in the same manner as in Example 1 except for this.

The obtained laminated window sample was considerably better than Comparative Example 1 and had fewer irregularities, but Example 1
It was not as good as it should have been, and the reflected image was uneven and distorted.

Claims (1)

[Claims] 1. In a laminate formed by sequentially laminating a thermoplastic resin layer, a film, and a thermoplastic resin layer, the film has a transparent conductive function or a light selective transmission function, and the film thickness is less than 130 μm, and A laminate characterized in that the two thermoplastic resin layers have a uniform surface on the surface in contact with the film surface, and an embossed surface on the other surface.