JPS6018612B2 - Method for bending glass plate with conductive lines - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for bending a glass plate with conductive lines.

Rear glass for automobiles uses a glass plate with conductive wires baked into the glass plate for electrical heating in order to prevent the glass surface from fogging up and melt ice and snow attached to the glass plate. (See Figure 1).

In this case, conductive paste containing metal, especially silver paste, is generally used as the material for the conductive wire, so for example, a glass plate printed with conductive paste with conductive wire is placed on a curved shape and heated and bent. When heating a glass plate in a heating furnace, the metal in the conductive paste, such as silver, reflects infrared rays, so the heating of the conductive strips is lower than that of other parts, resulting in uneven heating. Heat it. As a result, for example, when this glass plate is bent under its own weight, the sagging effect differs between the conductive wire portion and other portions, so the resulting product has optical wavy distortion as shown in Figure 2. arise. This phenomenon can be especially caused by deep bending of a glass plate printed with conductive wires using conductive paste, or by placing heater wires close together along the bending line to sharply bend the glass plate. and arranged,
This becomes noticeable when a curved portion is partially heated to a higher temperature and bent sharply, or when an attempt is made to heat a glass plate in as short a time as possible. The present invention was made with the aim of eliminating such drawbacks, and involves coating a conductive paste conductive wire containing metal formed on a glass plate surface with an endothermic material, and heating the conductive wire portion. The effect is that uniform heating can be obtained in the same way as other glass parts, or that the conductive wire parts can be heated more.

Next, the present invention will be described in detail with reference to embodiments shown in the drawings. Figure 1 shows a 1" car glass for an automobile equipped with a plurality of conductive wires 2 for heating with electricity, 3 a pair of busbars provided at both ends of these conductive wires 2, and 4) conductive wires 2. This is a lead wire for energizing the wire. The conductive wires 2 are printed on the glass plate 1 by, for example, screen printing using a conductive paste containing metal, for example, a silver paste containing silver and glass frit.

In this case, the bus bar 3 is also usually printed with silver paste together with the conductive strip 2. In the present invention, the conductive paste refers to Pt, Ag, Pd, Au, A
It is a paste or suspension-like mixture of various metal powders, glass frit, vehicle, and other desired additive components, and is easy to print on the surface of a glass plate and can be baked onto a glass plate. Show what you can do.

In the present invention, after the conductive wires formed on the glass plate 1 are covered with an endothermic layer 5 as shown in FIG. It is heated and softened inside and bent using its own weight.

Then, if necessary, the glass plate is further rapidly cooled and strengthened. The heat absorbing material 5 eliminates or reduces the infrared radiation response effect of the conductive paste, and when a glass plate is heated in a heating furnace, the glass in the conductive wire portion becomes opaque due to the effect of this heat absorbing material. heated to the same extent as
It works to uniformly heat the entire glass plate or to heat the conductive wire portion to a higher temperature. For this reason,
The heat absorbing material 5 is black or a gray color and absorbs Korean radiation heat in the heating furnace, heating the glass in the conductive wire portion to the same level or higher than the glass in other portions, and It is important not to impair the bonding strength to the glass and its electrical properties. Suitable materials for the heat absorbing material that meet this purpose include carbon paste, black paint, carbon powder, or black pigment, which is a mixture of carbon or black pigment with an organic binder.

Among these, carbon paste or carbon powder is particularly preferred because it works as an endothermic material at the initial stage of heating the glass, but as the glass is gradually heated to a high temperature, it burns out and does not remain in the product. On the other hand, in the case of an endothermic material that does not burn out, the black pigment remaining on the product may be wiped off after bending, or may be left behind, if necessary. When carrying out the present invention, the heat-absorbing material 5 is usually coated onto the conductive wire formed on a glass plate after the conductive wire of a conductive paste containing metal has dried.

This coating can be easily accomplished by screen printing, similar to the printing of conductive lines. In this case, the heat absorbing material 5 is printed over only the printed portion of the conductive line 2, or is coated so as to overlap the conductive line 2, as illustrated in FIG. Alternatively, in the case of powder, the conductive wire is coated with powder coating. As explained above, the present invention prevents the reflection of heat by the conductive paste by coating the conductive wires of conductive paste containing metal formed on a glass plate with an endothermic material and then heating them. Since the glass in the strip portion can be heated in the same way as the glass in other portions, it is possible to eliminate optical distortion caused by insufficient heating of the conductive wire portion.

In addition, the present invention compensates for insufficient heating of the portion where the conductive line is formed by printing a conductive paste containing metal on the glass plate surface by using an endothermic material formed thereon.
This method is applied to various conductive wires in which a conductive paste containing metal is formed on the surface of a glass plate. That is,
The present invention is applicable not only to conductive wires for electrical heating as shown in the drawings, but also to conductive wires for push bars. In addition, a conductive paste containing metal is formed on the bent portion of a glass plate bent at a sharp angle to hide optical distortion, or a conductive paste is formed as a pattern on the glass plate. The present invention can also be applied to the same conductive wire.

[Brief explanation of drawings]

Figures 1, 5, and 6 are plan views of an automobile rear glass having conductive wires, and Figure 2 is a plan view of a conventional product.
3 is an explanatory cross-sectional view of an embodiment of the present invention, and FIG. 4 is an explanatory cross-sectional view of the product similar to FIG. 2. In the figure, 1 is a glass plate, 2 is a conductive wire, 3 is a push bar, 5 is a heat absorbing material, and 6 is a conductive wire for a concealment band. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. A method of heating and softening and bending a glass plate on which conductive lines are formed using a conductive paste containing a metal,
A method for bending a glass plate with conductive lines, characterized in that the conductive lines formed on the glass plate are coated with an endothermic material and then heated. 2. In a method in which a glass plate on which conductive wires are formed using a conductive paste containing a metal is placed in a curved shape, heated and softened, and bent under its own weight, the conductive wires formed on the glass plate are made of an endothermic material. 2. A method for bending a glass plate with conductive lines according to claim 1, wherein the glass plate is heated after being coated. 3. A glass plate with conductive lines according to claim 1, characterized in that carbon paste is used as the heat absorbing material and the carbon paste layer covering the conductive lines is burnt out by heating the glass plate. Bending method.