JPH03257044A - Production of laminated glass containing hologram - Google Patents

Abstract

PURPOSE:To improve the adhesion between a hologram and a glass sheet and to obtain a laminated glass contg. a hologram without an object distortion due to dust, remaining air, etc., by previously embossing a hologram and enclosing the hologram in a laminated glass. CONSTITUTION:An adhesive film 2 is stuck on a hologram 1 formed on a glass substrate 3, the hologram 1 is stripped from the substrate 3 and placed on an embossment transfer film 5, and the hologram is pressed by a roller 4 and adhered to the film 5. The adhesive film 2 and hologram 1 are released from the transfer film 5 to obtain an embossed hologram 1. The embossed hologram 1 is then stripped from the adhesive film 2 and enclosed into a laminated glass obtained by adhering an adhesive synthetic resin film on at least one glass sheet to obtain a laminated glass contg. a hologram. The laminated glass is appropriately used for a combiner of the head-up display for the automobile, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laminated glass in which a hologram is encapsulated, which is used in a combiner of a head-up display for an automobile.

[Prior Art] In recent years, the use of holograms has attracted attention as in-vehicle display systems such as head-up displays for automobiles, as anti-glare devices, and as other devices such as stop lamps. The holograms required to construct a display device using such holograms are placed in various locations depending on their purpose, but because they do not take up much space, they are often attached to or incorporated into the windshield, rear glass, etc. For example, in head-up displays for automobiles, a hologram is placed at a predetermined position on the windshield as a combiner.

In such cases, the hologram may be applied directly to the windshield, but since holograms usually have very low abrasion resistance, to protect them, they must be placed inside the laminated structure of the windshield, where laminated glass is usually used. It has been proposed to use it by enclosing it.

[Problem to be solved by the invention] Generally, in such a hologram-encapsulated laminated glass,
It is conceivable that the hologram is enclosed between two glass plates together with a laminated interlayer film with an adhesive.As with ordinary laminated glass, a polyvinyl butyral (PVB) film is used as the laminated interlayer film. After temporarily fixing the hologram to one glass plate by applying water, etc., a PVB film is laminated between two pieces of laminated glass, pre-bonded by pressure using a roller, etc., and then heated to about 130°C. It is manufactured by pressurizing and crimping.

However, in such cases, when the hologram is temporarily attached to one glass plate by applying water, etc., there is a problem in that dust, dirt, etc. can easily get into the space between the hologram and the glass plate, causing bump-like defects. . In addition, air may remain between the hologram and the glass plate, which may cause diffraction defects when laminated into glass. Furthermore, there is also the problem that water pasting cannot be applied when the hologram is made of a water-impermeable photopolymer or the like.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and includes a hologram inside a laminated glass made by laminating an adhesive resin layer on at least one glass plate. The present invention provides a method for manufacturing a hologram-encapsulated laminated glass, which is characterized in that the hologram is embossed in advance.

In the present invention, since the hologram is embossed, it can be temporarily fixed to a glass plate without using wet paste. Specifically, there are two methods: a method in which a laminate in which a hologram is laminated at a predetermined position on a glass plate is placed in a vacuum chamber, and the vacuum chamber is evacuated to pre-press the hologram onto the glass plate; The hologram can be temporarily fixed by various methods such as crimping. In addition, it is possible to efficiently and sufficiently vacuum the air between the hologram and the glass plate, and to push out sufficient air using rollers, which reduces the amount of air remaining between the hologram and the glass plate, and also allows the air to be removed between the hologram and the glass plate. This will also prevent dirt and dust from entering the room.

In the present invention, laminated glass is a glass plate with a synthetic resin film laminated and bonded. Examples of its forms include glass/synthetic resin film, glass/synthetic resin film/glass,
There are structures such as glass/synthetic resin film/glass/synthetic resin film, glass/synthetic resin film/synthetic resin film, etc.

The depth of the embossing is preferably about 0.2 to 1 μm.
If it is smaller than this, it is difficult to obtain the effect of the present invention, and if it is larger than this, it will affect the diffraction grating of the hologram, making it impossible to obtain a good diffraction image.

A method for embossing a hologram will be described below.

FIGS. 1A to 1C are conceptual cross-sectional views showing an example of a method of embossing a hologram. Each figure shows that the process flows from left to right.

As in the present invention, a hologram used by being sealed in a laminated glass is preferably in the form of a film. For example, a photosensitive agent such as silver salt, DCG, photopolymer, or photoreactive resist is coated on a substrate with a spin cord or the like. Several μ layers to several tens of μ
After applying it uniformly to the thickness of the shoe, a laser beam is used to form a diffraction grating. After that, it is developed and bleached to obtain a hologram.

If the hologram is formed on a resin film,
If the emboss is layered with a film for emboss transfer and pressed with a roller, the emboss will be transferred, but if the emboss is being formed on a highly rigid object such as a glass plate, an adhesive made of polyethylene terephthalate (PET) or other material may be used. It is desirable to attach a single-layer hologram to a support film such as a film and peel it off from a glass substrate, etc. The thickness of the support film can be selected as necessary, but it is usually 5 to 30 μm.
The thickness of the hologram is preferably about 20 to 100 μm. This situation is shown in FIG. A barrel adhesive film 2 is pasted and the hologram l is peeled off from the glass substrate 3.0 Next, the hologram surface is stacked on top of the emboss transfer film 5, which has an emboss of a desired depth on its surface, and is then rolled using a roller 4. The thickness of the emboss transfer film is arbitrary, but it is preferably about 50 to 500 μm and is an antistatic film that does not easily attract dust due to charging. In addition, the pressure may be heated to about 50 to 100 degrees Celsius if necessary during pressurization and crimping, and the pressure should preferably be 1 to 2 kg/cm. If it is smaller than this, the emboss will not be transferred sufficiently. If it is larger than this, the surface of the hologram will be too rough.Finally, peel off the adhesive film 2 and hologram 1 from the emboss transfer film 5 (see Figure 1).
C)) Obtain an embossed hologram.

The hologram may be encapsulated in the laminated glass while being attached to the above-mentioned support film, but in order to make the parting line of the hologram conspicuous (and to reduce perspective distortion of the laminated glass due to the thickness of the hologram). , then peel,
It is desirable to encapsulate the hologram alone in laminated glass.

In order to encapsulate a single hologram in laminated glass, -
The hologram surface of the hologram with support film is glued onto the base glass for laminated glass, and the support film is attached.
Can only be peeled off. Double-sided adhesive tape, optical adhesive, thermoplastic film, silane coupling agent, etc. can be used to adhere the hologram onto the base glass for laminated glass. These are attached to the hologram surface or glass surface to paste the glass and hologram. The lower the viscosity of the optical adhesive, the better (several tens of cps to several cps is preferable. It is best to apply the optical adhesive with a dip coat or spin cord, as it can be applied evenly. After the glass and hologram are bonded, remove the support film. .

FIG. 2 is a conceptual cross-sectional view showing this situation, and also shows how the process flows from left to right. Here, 6 is a roller that applies pressure for pressure bonding, and 7 is a raw glass for laminated glass. When using a silane coupling agent as an adhesive, it is preferable to heat it to 110° C. or higher during pressure bonding.

Incidentally, this method can be applied to the case where a single hologram is encapsulated in laminated glass, regardless of the presence or absence of embossing.

When a single hologram is bonded to the base glass for laminated glass using the method described above, in the present invention, since the hologram is embossed, air, etc. between the hologram and the base glass for laminated glass is removed during pressure bonding with a roller. can be pushed out sufficiently to prevent residual air and dirt from entering.

In the present invention, since the hologram is embossed, the hologram can be bonded to the glass plate in addition to the roller pressure bonding described above. In particular, by stacking holograms at predetermined positions on a glass plate, placing them in a vacuum chamber, and evacuating the vacuum chamber, it is possible to prevent defects such as dirt and dust entering between the hologram and the glass plate. Here, as for the vacuum chamber, a rubber bag or the like can be used in addition to an ordinary vacuum chamber.

Further, in order to more completely press the hologram onto the glass plate, it is more preferable to use a double vacuum system.

One embodiment of the dual vacuum system will be described with reference to FIG. FIG. 3 is a conceptual cut-away diagram showing one embodiment of the double vacuum system, in which 1 is a hologram to be laminated, 7 is a glass plate, 32 is a cover film, and 14 is a hologram for attaching the cover film. A frame body, 33 is a pack film which forms a pair with a cover film, forms a first vacuum system 2o inside the vacuum chamber and holds a glass plate, 1o is a vacuum chamber forming a second vacuum system, 16 is a vacuum chamber The exhaust port 18 for evacuating the lo is connected to the first vacuum system 20 through the peripheral exhaust port 21.
This is an exhaust port for vacuum evacuation. In this device, the hologram 1 is positioned and arranged at a predetermined position on the glass plate 7, and the hologram 1 and the pack film 33
, the outer peripheral frame 15, and the gaskets 35 and 36, the vacuum chamber 1 as the second vacuum system is formed inside the vacuum system 2o.
A first vacuum system 2o is formed.

Although this vacuum system 20 is inside the vacuum chamber 10 consisting of the upper lid 29 and the surface plate 3o, it is independent from the vacuum chamber 10, and is connected to the exhaust port 16 and the vacuum pump (
(not shown) allows vacuum evacuation and atmosphere introduction operations.

The outer peripheral frame 15 has a shape that matches the shape of the peripheral part of the plate-shaped body, and is made of a wooden mold, a metal mold, a resin mold, a ceramic mold, etc., and is a peripheral frame that connects the first vacuum system 20 and the exhaust port 18. One or a plurality of exhaust ports 21 or a series of exhaust ports 21 are arranged.

The pack film 33 can be made of various materials as long as it can follow the shape of the plate-shaped body 2 and is non-adhesive. Note that if the seal between the glass plate 7 and the gasket 36 is sufficient, the pack film 33 can be omitted.

In the apparatus shown in FIG. 3 described above, first, in order to sufficiently remove dust and improve the adhesive strength of the hologram,
Apply an adhesive such as a silane coupling agent to the hologram. The glass plate 7 is placed inside the device itself. Place the cover film 32, which has been sufficiently dust-removed and stretched on the frame 14, on the outer periphery of the gasket 35 on the outer peripheral frame 15. If the seal between the gasket 35 and the cover film 32 is insufficient, the frame 14 may be fixed to the outer peripheral frame 15.

Here, the upper lid 29 of the vacuum chamber is lowered and the entire vacuum chamber 1o including the first vacuum system 20 inside is evacuated through the exhaust port 16.18. 16 is opened to the atmosphere, and the hologram 1 is brought into close contact with the glass plate 7.

After the hologram is preliminarily bonded to the glass plate, the synthetic resin film laminated to the glass plate is processed into a predetermined shape and superimposed on the glass plate, using the method used for ordinary laminated glass. Glued. That is, they are stacked one on top of the other, and after being evacuated, they are bonded by heating, or after being heated and preliminarily bonded, they are bonded by applying pressure and heating. In this case, the hologram film is preferably sealed between the glass plate and the resin film in order to protect it from external damage and the like.

As the synthetic resin membrane, commonly used ones such as a PBV membrane, a urethane membrane, and an ethylene-vinyl acetate copolymer may be used depending on the purpose.

In the present invention, the hologram is not pressure-bonded to the base glass for laminated glass in advance (it can also be done at the same time as laminating and adhering the synthetic resin film. In other words, in such a case, at least the hologram is bonded to the glass plate for laminated glass). The laminate stacked between synthetic resin films is placed in a vacuum chamber, and the vacuum chamber is evacuated to pre-press the laminate and encapsulate the hologram in a predetermined position.In this case, the vacuum chamber is also In addition to ordinary vacuum chambers and rubber bags, the above-mentioned double vacuum system can also be used preferably.The pre-pressed laminate is heated and pressurized in an autoclave, etc., and then the main crimped body is used. When using butyral, the conditions in the autoclave are 110-150
℃, 8 to 10 atmospheres, and 30 to 60 minutes.

The present invention can be applied in various ways without sacrificing its effects.

〔Example〕

(Example-1) As shown in Fig. 1(a), a hologram formed on a glass substrate has a polyethylene terephthalate (PET)
The hologram was peeled off from the glass substrate by attaching a μm-thick adhesive tape (0.7μm) as shown in Figure 1(b).
Layer the embossed transfer film at a depth of 2.0 cm and the hologram on the adhesive tape so that the hologram side surface is in direct contact with the embossed surface of the embossed transfer film, and press with a pressure roller at a pressure of 2 kg/cm. In addition, the first
As shown in Figure (C), the hologram on the adhesive tape was peeled off from the embossed transfer film to obtain an embossed hologram with a depth of 0.2 to 0.5 .mu.m.

An epoxy optical adhesive was dropped onto the hologram and coated uniformly to a thickness of 2 to 3 μm using a spin coater.

As shown in Figure 2, press this with a pressure roller (4 kg/c+++
The adhesive tape was pressed onto a glass plate (2t+a thickness) for laminated glass using a pressure of 100 ml, and after the adhesive had solidified, the adhesive tape was peeled off.

After that, an intermediate film made of PVB film (0.76 mm thick),
Another glass (2 mm thick) is laminated on top of it to form a laminate, and this is placed between the pack film and cover film of a double vacuum system vacuum device as shown in Figure 3. After first simultaneously evacuating the vacuum system and the second vacuum system to 1 torr, only the second vacuum system was returned to atmospheric pressure, and the laminate was pre-pressed. This was heated to 130℃ in an autoclave.
The pressure was maintained at 10 atm for 40 minutes to produce a hologram-encapsulated laminated glass. The obtained hologram-encapsulated laminated glass was in good condition, free from any unevenness caused by dust or air remaining in front of the hologram and the glass.

(Example 2) In Example 1, when pressing the hologram on the adhesive tape onto the glass plate for laminated glass, instead of using the pressing roller, a double vacuum system vacuum device as shown in Fig. 3 was used. . That is, a hologram on an adhesive tape with an epoxy optical adhesive coated on the hologram side surface is placed at a predetermined position on a glass plate, and it is placed between a pack film and a cover film of a vacuum device, After simultaneously evacuating the first vacuum system and the second vacuum system to 1 torr, only the second vacuum system was returned to atmospheric pressure, and the hologram was pressed onto a glass plate. After the adhesive had further solidified, the adhesive tape was peeled off.

Thereafter, a hologram-encapsulated laminated glass was manufactured in the same manner as in Example 1.

The obtained hologram-encapsulated laminated glass was of good quality, with no distortion as in Example 1.

(Example-3) The embossed hologram obtained in the same manner as in Example 1 was laminated at a predetermined position on a glass plate for laminated glass (2 liters thick),
Furthermore, on top of that, a PVB film (0,76111I11 thickness),
Glass plates (2 mm thick) are laminated in this order, and the resulting laminate is placed between the pack film and cover film of a vacuum system as shown in Figure 3, and the first vacuum system and the second After the vacuum systems were simultaneously evacuated to 1 torr, only the second vacuum system was returned to atmospheric pressure, and the laminate was pre-pressed.

Thereafter, in the same manner as in Example 1, the temperature was set at 130°C in an autoclave.
The pressure was maintained at 10 atm for 30 minutes to produce a hologram-encapsulated laminated glass.

The obtained hologram-encapsulated laminated glass was in good condition, free of lump distortion, as in Example 1.

[Effects of the Invention] In the present invention, since the hologram is embossed, the adhesion of the glass plate is improved, so that distortion caused by dust, dirt, and air residue can be prevented.

Furthermore, since the flatness of the hologram is improved, a clear diffraction image can be obtained.

Further, according to the invention according to claim 5, since the hologram is encapsulated in the laminated glass as a single hologram, the parting line of the hologram can be made inconspicuous, and perspective distortion caused by the thickness of the hologram can be reduced. be able to.

[Brief explanation of drawings]

Figure 1 is a conceptual cross-sectional view showing an example of a method for embossing a hologram, Figure 2 is a conceptual cross-sectional view of peeling a hologram from a support film, and Figure 3 is an embodiment of a double vacuum system. 4 is a cross-sectional view of a typical example of a hologram-encapsulated laminated glass. 1: Hologram, 2 Substrate, 3: Support film, 4: Pressure roller 5: Emboss transfer film, 8: PVB film, 10: Second vacuum system, 20
: first vacuum system, 32: cover film, 33: back film. Ca2 city l diagram

Claims (5)

[Claims] (1) In a method for manufacturing hologram-enclosed laminated glass in which a hologram is encapsulated inside a laminated glass made by laminating and bonding an adhesive synthetic resin film to at least one glass plate, the hologram is embossed in advance. A method for producing hologram-encapsulated laminated glass, characterized by: (2) In the method for producing a hologram-encapsulated laminated glass according to claim 1, before laminating the glass plate and the synthetic resin film, the laminate in which the embossed hologram is laminated at a predetermined position on the glass plate is placed in a vacuum chamber. manufacturing a hologram-embedded laminated glass characterized by: placing the hologram in a vacuum chamber, pre-pressing the hologram onto a glass plate by evacuating the vacuum chamber, and then bonding the glass plate and synthetic resin film by applying heat and pressure. Method. (3) In the method for manufacturing a hologram-encapsulated laminated glass according to claim 1, before laminating the glass plate and the synthetic resin film, the embossed hologram is pressed onto the glass plate with a roller, and then heat and pressure are applied. A method for producing a hologram-encapsulated laminated glass, characterized in that the glass plate and the synthetic resin film are bonded together. (4) In the method for manufacturing a hologram-encapsulated laminated glass according to claim 1, a laminate in which an embossed hologram is laminated between a glass plate and a synthetic resin film is placed in a vacuum chamber, and the vacuum chamber is evacuated. 1. A method for producing a hologram-encapsulated laminated glass, comprising: pre-pressing a laminate by pulling, and then bonding the glass plate and synthetic resin film by applying heat and pressure. (5) The hologram-encapsulated laminated glass according to any one of claims 1 to 4, wherein the hologram is encapsulated as a single unit removed from the substrate on which the hologram is exposed and formed. Production method.