JPS625849A - Functional film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a functional film for laminated glass. More specifically, laminated glass in which polyvinyl butyral is laminated on both sides of a functional film and further sandwiched between transparent plates such as glass plates, or laminated glass in which transparent plates such as glass plates, polyvinyl butyral, and functional films are laminated in sequence. The present invention relates to a functional film for use in laminated glass for windows, such as the above, and a functional film for laminated glass with improved adhesion in which a metal thin film layer is provided on the non-functional surface of the functional film.

[Prior Art] Laminated glass windows are used in transparent openings that require safety, such as windows in automobiles, trains, airplanes, etc., or in some building windows. The basic composition of laminated glass windows is transparent plates such as glass plates sandwiched between thermoplastic resin sheets, such as the widely used polyvinyl butyral sheets (such as inorganic-non-laminated glass), but there are also A film has been interposed for the purpose of imparting functionality. For example, a method of interposing a film with excellent mechanical strength to increase safety, a method of interposing a transparent conductive film to prevent condensation, or a method of interposing a film that allows visible light to pass through but does not allow near-infrared light to pass through. A method has been proposed in which a film having a permselective function is interposed.

These functional films are laminated with polyvinyl butyral on both sides, sandwiched between transparent plates such as glass plates, and then pressed and heated to form a laminated glass window.

Also, Special Publication No. 60-16344, Special Publication No. 60-39
There is an inorganic-organic laminated glass in which a transparent plate such as a glass plate and a functional film are combined with a polyvinyl butyral sheet, as disclosed in Publication No. 546@.

By installing this inorganic-organic laminated glass with its functional film side facing toward the inside of an automobile windshield, it is possible to significantly reduce obstacles to the driver in the event of an accident. For example, in the case of an accident, the driver's head collides with the windshield glass and the outer glass of the laminated glass is shattered, but the functional film and polyvinyl butyral interlayer film prevent the driver's head from penetrating the windshield. In addition, shards of the outside glass will not reach the driver's body, preventing lacerations.

Functional films used for this purpose include:
In addition to the above-mentioned film with a conductive film and selectively transmitting light film, there is also a hard-coated film with a high surface abrasion (
scratch-resistant film).

These functional films are made by placing a polyvinyl butyral interlayer on a transparent plate such as a glass plate, and placing a functional film on the interlayer so that its non-functional side is in contact with the polyvinyl butyral.
It is then layered, pressed and heated to form a laminated glass window. The transparent plate such as a glass plate used in this case is a single plate such as a glass plate, or the above-mentioned inorganic-inorganic laminated glass.

However, such laminated glass using a functional film has a problem in adhesiveness, particularly in low temperature adhesiveness.

In particular, there has been a problem with the adhesion of the non-functional side of the functional film that has not been functionally processed such as conductivity and selective light transmission. Application of various adhesives has been studied for some time, and products with satisfactory adhesive properties at room temperature have been obtained, but -
Adhesive strength at low temperatures such as 20° C. was still insufficient.

[Purpose of the Invention] As a result of various studies on the above-mentioned problems, the present inventors have found that good adhesion can be achieved by providing a metal thin film of 50A or less on the non-functional surface of a functional film that has not been functionally processed. It was discovered that a functional film could be obtained, and the present invention was achieved. An object of the present invention is to provide a functional film that improves the adhesion of laminated glass, especially the adhesion at low temperatures.

[Configuration and Effects of the Invention] That is, the present invention provides a laminated glass in which polyvinyl butyral is laminated on both sides of a functional film and further sandwiched between transparent plates such as glass plates, or a transparent plate such as a glass plate, polyvinyl butyral, Functional films used in laminated glass windows such as laminated glass in which functional films are sequentially laminated are used by laminating polyvinyl butyral so that the non-functional surface is in contact with the polyvinyl butyral, and a metal thin film layer of 50 Å or less is applied to the non-functional surface. This is a functional film characterized by the provision of Note that the non-functional surface of the functional film herein refers to the surface on which no given functional processing has been performed, as described above, and the surface opposite to the surface on which the given functional processing has been performed.

The details of the configuration of the present invention will be described below.

A functional film refers to a plastic film to which various functionalities are added. Here, the material of the film is
It is a transparent plastic film.

The following polymer resin film is used for this purpose. For example, polyethylene terephthalate, polyethylene 2.
Examples include polyester resins such as 6-naphthalate and polybutylene terephthalate, polycarbonate resins, polyolefin resins such as polyethylene and polypropylene, polyvinyl chloride, polyphenylene sulfide resins, polysulfone resins, polyamide resins, cellulose resins such as cellophane and cellulose triacetate, and the like.

Among these, biaxially stretched polyethylene terephthalate film has excellent dimensional stability.

It is the most suitable film due to its transparency, smoothness, and mechanical properties.

Functionality includes transparent conductivity and selective light transmission.

Examples include wear resistance.

Examples of transparent conductive functionalities include thin films made of indium oxide and tin oxide, thin films of tin oxide, and gold.

Examples include thin films of metals such as silver, copper, and aluminum. In addition, examples of functional materials that provide selective light transmittance that prevent invisible infrared rays from passing through solar energy include gold, silver, copper, aluminum, nickel, palladium, tin, and alloys or mixtures thereof. Examples include a thin film of these metals, a thin film of these metals laminated with a conductive material, and a lamination of these structures repeatedly. Examples of the conductive material include titanium oxide, bismuth oxide, zinc sulfide, tungsten oxide, indium oxide, zirconium oxide, and silicon oxide. Further, examples of functionally imparting wear resistance include the silicone-based cured film formed by hydrolytic condensation of alkoxysilane described in the above-mentioned publication, or the polyfunctional acrylic-based cured film polymerized and crosslinked by ultraviolet irradiation.

By the way, in the present invention, as described above, metal 4? Provide a membrane layer. In the present invention, the metal thin film layer that imparts adhesiveness is △u, l+.

Cu, Cr, Co, In, Sn, Zr, Ti.

A thin film of any metal such as Ni can be used. Any known method such as vapor deposition, sputtering, ion blasting, chemical plating, etc. can be used to provide the thin film of these metals on the plastic film. In particular, plastic films that have been previously treated with ion bombardment, plasma, or corona treatment are preferably used. The thickness of the metal thin film is preferably 50 Å or less, preferably 30 Å or less. If the film thickness is thicker than this, the visible light transmittance of the functional film decreases, making it undesirable for use in laminated glass windows.

The functional film of the present invention is laminated with polyvinyl butyral on both sides and then sandwiched between transparent plates such as glass plates, or laminated with polyvinyl butyral on transparent plates such as glass plates, and then laminated with pressure and heat. It is said that Here, the transparent plate can of course be a single plate such as a glass plate or a transparent plastic plate.
It goes without saying that a laminate such as the above-mentioned inorganic-inorganic laminated glass may be used.

Polyvinyl butyral is, as a rule, a plasticizer, heat stabilizer and UV absorber that is processed thermoplastically.

Any polyvinyl butyral mixed with a colorant or the like is suitable. Polyvinyl butyral, which must be thermoplastically formed into a film, usually contains a large amount of plasticizer. Polyvinyl butyral sheets used for laminated glass usually contain a plasticizer in an amount of 10 to 60% by weight, preferably 20 to 40% by weight. As the plasticizer, dioctyl phthalate, diethylene glycol, triethylene glycol, etc. can be used.

The sheet thickness is 0.10 to 1.50 mm, preferably 0.
．． 30 to 0.80 mm is desirable. To produce laminated glass with a functional film sandwiched or laminated, a laminate of the functional film and polyvinyl butyral may be made in advance, and then the laminated glass may be made by sandwiching or laminating the functional film with glass plates. , glass.

Polyvinyl butyral and functional films may be sequentially laminated and laminated at once to form glass. Laminated glass is usually 12
10Kg/c+ in temperature autoclave from 0℃ to 140℃
This is done by processing under pressure of J or higher.

[Example] Adhesive strength was measured as follows. Polyvinyl butyral sheets with a thickness of 0.38 mm that have been placed in an atmosphere of 20°C and 20% RH for three days or more are laminated on both sides of the functional film, and then placed in a vacuum bag and decompressed with a vacuum pump so that atmospheric pressure is applied. The mixture was heated at 120° C. for 40 minutes.

After that, the sample was taken out, cut into strips with a width of 10 m, and
The adhesion force between the non-functional surface of the functional film and the polyvinyl butyral sheet was measured at a tensile speed of 2 cm/min in a universal tensile tester (manufactured by Instron) at a temperature of 5°C (room temperature adhesion).

Further, both sides of the polyvinyl butyral/functional film/polyvinyl butyral laminated in the above method were sandwiched between two ends of thick glass, and placed in an autoclave and heated with nitrogen at 120°C.
A pressure of 3 kg/ci was applied for 40 minutes to produce laminated glass. The laminated glass was cooled to -20° C. and the glass surface was tapped with a hammer to check the adhesion of each laminated surface (low-temperature adhesive strength).

Examples 1 and 2. Comparative Examples 1 to 4 A biaxially stretched polyethylene terephthalate film with a thickness of 100 μm was set in a vacuum deposition machine and
Silver was evaporated to a thickness of 120 nm at a vacuum level of 300 nm, and titanium oxide was further laminated to a thickness of 300 nm. The film produced in this way has a visible light transmittance of 75% and a wavelength of 10μ.
It exhibited an infrared reflectance of 88% and had a light selective transmission function.

Various adhesive layers were formed as described below on the non-functional surface of this functional film opposite to the functional surface treated with the light selective transmission function, and the adhesive properties thereof were evaluated.

In Examples 1 and 2, silver and titanium were applied by sputtering to a film thickness of 20 mm, in Comparative Example 1 nothing was applied, and in Comparative Examples 2, 3, and 4, polyester adhesive (manufactured by Toyobo Co., Ltd.) was used. Byron 200), butyral resin (
Denki Kagaku Kogyo ■Denka Butyral 2000-L)
, tetrabutyl titanate (B-1 manufactured by Nippon Soda) 0
．． It was provided by coating to a film thickness of around 1 μm. The evaluation results of adhesiveness are shown in Table 1, and the one provided with the metal of Example 1.2 showed good adhesive strength both at room temperature and at a low temperature of -20°C.

(Margin below) Table 1 Example 3. Comparative Example 5 A 30% solution of cyanuric acrylate in methyl ethyl ketone was applied to a 100 μm thick biaxially stretched polyethylene terephthalate film using a No. 10 bar coater, dried, and then irradiated with a 30 W mercury lamp for 3 minutes to form a wear-resistant cured film. .

Next, as Example 3, zirconium was applied as a metal thin film layer to a thickness of 10 mm on the non-functional surface of the hard coat film opposite to the functional surface imparting wear resistance using the same method as in Example 1. Ta. As Comparative Example 5, a sample of the hard coat film without any provision on the non-functional side was prepared. A polyvinyl butyral sheet was laminated on the non-functional side of these samples in the same manner as described above, and the sheets were laminated by pressure and heating, then cooled to -20°C, taken out, and tested for the adhesion between the polyvinyl butyral and hard coat film. Examined.

Example 3, which had a zirconium metal IFa layer as an adhesive layer, adhered well to polyvinyl butyral, but Comparative Example 5, which had no adhesive layer, easily separated from polyvinyl butyral.

Claims (1)

[Claims] 1. A functional film for laminated glass that is laminated so that polyvinyl butyral and a non-functional surface are in contact with each other, characterized in that a thin metal film with a thickness of 50 Å or less is provided on the non-functional surface. functional film. 2. The functionality according to claim 1, wherein the laminated glass is a laminated glass having a structure in which polyvinyl butyral is laminated on both sides of a functional film, and this laminate is further sandwiched between transparent plates such as glass plates. film. 3. The functional film according to claim 1, wherein the laminated glass is a laminated glass in which a transparent plate such as a glass plate, polyvinyl butyral, and a functional film are sequentially laminated.