JPH08259280A - Laminated glass - Google Patents

Abstract

PURPOSE: To provide a laminated glass sufficient in resistances to penetration and impact and with the effect of UV on a polarizing direction control film reduced. CONSTITUTION: This laminated glass 7 is obtained by making two glass sheets adhere to each other through an intermediate film. A polarizing direction control film 1 is adhered to the face on the intermediate film side of the glass 5' on the outdoor side through a UV absorbent-contg. adhesive 4. The film 1 is torsion-nematically oriented in the liq. crystal state, and a double image is not seen over the visible region due to an optical rotor consisting of a liq. crystal polymer vitrified below the transition temperature of the liq. crystal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head-up display (hereinafter abbreviated as HUD) which optically projects display light and superimposes the foreground in or near the near-field of vision so that the driver can visually recognize it. The present invention relates to a laminated glass in which a polarization direction adjusting film used for the above purpose is installed.

[0002]

2. Description of the Related Art Conventionally, as a HUD, a reflection film is directly coated on a windshield, and a film having a reflection film is sandwiched between two sheet glasses of the windshield. In addition to the No. etc., the present applicant has also applied for Japanese Patent Application No. 4-196841.
Both of them, for example, do not necessarily have sufficient penetration resistance and impact resistance as safety glass for automobiles.
It was difficult to satisfy the penetration resistance test and the impact resistance test specified in 11 (automobile safety glass) and R3212 (automobile safety glass test method).

The present invention has been made in view of the above circumstances, and provides a laminated glass which has not only sufficient penetration resistance and impact resistance, but also reduced the influence of ultraviolet rays on the polarization direction adjusting film. Aim to

[0004]

The laminated glass of the present invention is a laminated glass in which two plate glasses are adhered with an intermediate film, and the polarization direction adjusting film contains an ultraviolet absorber on the surface of the outdoor glass on the intermediate film side. The polarization direction adjusting film is twisted nematically aligned in a liquid crystal state, and when a liquid crystal transition point is used, an optical rotator composed of a liquid crystal polymer in a glass state is used. , Because it is possible to prevent the double image from being seen over the entire visible range, which is preferable.

[0005]

[Function] The impact resistance test is to check whether or not the adhesiveness or strength required for the impact of a small, hard flying object is the minimum, and it is necessary to confirm whether the glass manufactured by the same method as the product or laminated glass cut from the product. It is placed by placing it on a support frame with the outdoor side facing up, and letting steel balls fall naturally from a predetermined height.However, the interface between the interlayer film such as polyvinyl butyral and the plate glass has a very strong adhesive force, so the polarization direction can be adjusted. The interface of the film or the like adhered to the plate glass with a pressure sensitive adhesive or the like, the adhesive force must be relatively weak, and when the polarization direction adjusting film is adhered to the interlayer film side surface of the outdoor glass as in the present invention. , The outdoor glass of this part breaks and peels off, but even if the indoor glass breaks, it is firmly adhered to the interlayer film, so it almost falls to the lower side, that is, the indoor side. However, if the polarization direction adjusting film is adhered to the surface of the indoor side glass plate on the intermediate film side as in the past, the glass plate on the outdoor side will almost always break from the intermediate film when a shock is applied. However, it does not peel off, but the glass plate on the indoor side of this part not only cracks, but also the adhesive strength is relatively weak, so the amount of peeling increases and it falls to this part on the indoor side, and there is sufficient resistance to meet the JIS standard. Impact cannot be obtained.

The penetration resistance test is to check whether or not the laminated glass used for the front window has the minimum required penetration resistance. The indoor side of the glass manufactured by the same method as the product or the laminated glass cut from the product is tested. Put it on the support frame with it on top, and do it by letting the steel ball fall naturally from a predetermined height, but twist nematic orientation in the liquid crystal state,
Below the liquid crystal transition point, a polarization direction adjusting film such as a λ / 2 plate as well as an optical rotator made of a liquid crystal polymer in a glass state is adhered to the interlayer side surface of the outdoor glass. Even if it adheres to the interlayer film side of the indoor glass, it does not penetrate and satisfies the JIS standard.

Further, when the polarization direction adjusting film is provided on the indoor side of the interlayer film such as polyvinyl butyral, the interlayer film absorbs ultraviolet rays, so that there is little influence even when sunlight is irradiated, but like the present invention. When it is provided outside the interlayer film, it is directly affected by sunlight, but the effect of sunlight can be reduced by bonding with an adhesive containing an ultraviolet absorber.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. 1 and 2 each use a laminated glass according to an embodiment of the present invention as an automobile windshield,
FIG. 3 is a schematic view of a main part applied as a HUD and a cross-sectional view of a main part showing a configuration of an optical rotator as a polarization direction adjusting film.

As the polarization direction adjusting film 1, a laminated glass of the present invention using an optical rotator made of a liquid crystal polymer which is twisted nematically aligned in a liquid crystal state and is in a glass state at a liquid crystal transition point or lower is used as a windshield of an automobile (front). This is an example of application as glass).

The optical rotator is prepared by applying a liquid crystal polymer on a transparent substrate such as a transparent plastic film such as polyethylene terephthalate (PET) and applying a shearing force to the substrate.
The polymer is one in which the liquid crystal orientation is fixed by heat treatment and cooling, and as the polymer, those having a twisted nematic orientation in the liquid crystal state and being in the glass state below the liquid crystal transition point can be used. ,
A main chain type liquid crystal polymer such as polycarbonate or polyester imide, or a side chain type liquid crystal polymer such as optically active polyacrylate, polymethacrylate, or polymer funnel can be used.

As shown in FIG. 2, a barrier layer 2 for preventing migration of the plastic material of the interlayer film is provided on both sides of the optical rotator as the polarization adjusting film 1 having a thickness of 5 μm thus obtained. For example, as an acrylic resin layer having a thickness of 5 μm and as a protective layer 3, for example, an optical laminated film coated with an acrylic resin layer having a thickness of 5 μm is coated with an acrylic adhesive 4 containing a benzotriazole ultraviolet absorber. Glue to the outer plate glass 5 '.

After that, an ordinary autoclave process is performed by using the interlayer film 6 such as polyvinyl butyral together with the indoor side plate glass 5 to obtain a laminated glass. The laminated glass 7 thus obtained has a JIS standard R321.
1, satisfying the penetration resistance test and the impact resistance test specified by R3212, and in the light resistance test by the sunshine weather meter, the yellowness YI is YI = 100.
(1.28X-1.06Z) / Y (where X, Y, Z
Is the tristimulus value of the test sample under standard light C) of 5
When the change after 00 hours was measured, the YI value when the ultraviolet absorber was not contained was 8.3 at the beginning, but after the lapse of 500 hours, the YI value changed significantly to 62.0. The laminated glass adhered by the adhesive containing the ultraviolet absorbent of the invention had an initial value of 8.9,
After 500 hours, it was 13.4, which was almost the same as in the initial state and showed extremely good light resistance.

As shown in FIG. 1, the laminated glass of the present invention is mounted on an automobile windshield so that display information is incident on the windshield at a Brewster's angle (θ = 56.3 °). By the display means 8 such as a CRT, a fluorescent display, a liquid crystal display, etc. and the S polarization means 9 arranged in the first place, when the display light such as the operation information including both the S wave and the P wave is emitted from the display means 8, the S polarization is generated. S by means 9
The light polarized into the wave reaches the indoor side glass plate, and the light reflected on this surface (interface with air) reaches the eyes 10 of the driver to visually recognize driving information and the like.

On the other hand, since a part of the light incident on the windshield is polarized into a P wave by the optical rotator, there is almost no reflection at the interface between the outdoor side plate glass and the air, and the light is almost emitted out of the room. The displayed image does not appear double in the eye and can be visually recognized well.

Although the preferred embodiments have been described above, the present invention is not limited to these, and various applications are possible. In each of the examples, the laminated glass of the present invention has been described as an example applied to a windshield for an automobile. However, since it is particularly excellent in penetration resistance and impact resistance, it is suitable for vehicles such as ships, airplanes and trains. It can be applied as a windshield.

As the polarization direction adjusting film, an optical rotator or a birefringent transparent film made of a liquid crystal polymer which has a twisted nematic orientation in a liquid crystal state and becomes a glass state at a liquid crystal transition point or below, a λ / 2 plate, etc. A polarizing direction adjusting film, etc. can also be used.

[0017]

INDUSTRIAL APPLICABILITY The laminated glass in which the polarization direction adjusting film of the present invention is provided not only has sufficient penetration resistance and impact resistance, but also reduces the influence of ultraviolet rays on the polarization direction adjusting film and is suitable for automobiles. It can be suitably used for windshields and the like.

[Brief description of drawings]

FIG. 1 is a schematic view of a main part in which a laminated glass in an example is used as a windshield for an automobile and applied as a HUD.

FIG. 2 is a cross-sectional view of an essential part showing a configuration of an optical rotator that is a polarization direction adjusting film in an example.

[Explanation of symbols]

 1 Polarization Direction Adjustment Film 2 Barrier Film 3 Protective Film 4 Adhesive 5, 5'Plate Glass 6 Intermediate Film 7 Laminated Glass 8 Display Means 9 S Polarizing Means 10th

Claims (2)

[Claims] 1. A laminated glass in which two plate glasses are adhered with an intermediate film, wherein a polarization direction adjusting film is adhered to the surface of the outdoor side glass on the side of the intermediate film with an adhesive containing an ultraviolet absorber. Laminated glass. 2. The laminated glass according to claim 1, wherein the polarization direction adjusting film is an optical rotator made of a liquid crystal polymer which is twisted nematically aligned in a liquid crystal state and becomes a glass state at a liquid crystal transition point or lower. .