JP2975031B2 - Manufacturing method of window glass with frame - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a window glass with a frame, such as a frame or a molding, used as a window glass for a vehicle, an industry, or a building.

[Related Art] As a method of manufacturing a window glass in which a frame or a frame such as a molding is integrated with a glass plate, a method of setting a glass plate in a mold and injecting a resin into the mold to integrally mold the glass plate is used. Are known. There are roughly two types of resins to be injected at this time. One is a so-called RIM method in which two kinds of reactants are simultaneously injected and mixed, as typified by urethane, to react and form a resin in a mold. In the RIM method, the pressure in the mold is a number
that the glass plate is less likely to crack because it is kg / cm ² ~10kg / cm ² degrees and a low pressure, it is possible to absorb the curvature dimensional error of the glass plate using a substantial thickness of the elastic body further seal portion Although it has advantages, on the other hand, (1) the material price is high, (2) the product must be painted to compensate for the poor weather resistance of the material, and (3) the demolding time is long because it reacts in the mold. Due to such disadvantages in cost and productivity, they are not widely adopted. The other is a method in which a thermoplastic resin represented by vinyl chloride is heated and melted and injected, and is widely used because of its good cost and productivity. However, since a molten resin is injected, the resin is often used under the conditions of a resin temperature of 180 ° C. or more and a pressure of 300 kg / cm ² or more.

Therefore, when laminated glass is used as the glass plate to be set in the mold, these glass plates are broken by the action of the heat and pressure of the injection resin, and the glass plate is broken or the interlayer film (laminated glass) is deteriorated or damaged. Occurs. If a resin composition that melts at a relatively low temperature in a thermoplastic resin or a resin composition that has a low viscosity at the time of melting and has extremely good fluidity and can be injection-molded at a low pressure is used to solve the above problems, it is necessary as a wind molding material. Another problem is that basic physical properties such as tensile strength, elongation, and cold resistance are greatly deteriorated.

Therefore, in the prior art, the molding of a molding integrally with a laminated glass such as a windshield for a vehicle including an automobile is limited to the method using the RIM, and a method of manufacturing the molding more cheaply and more efficiently than the RIM has been desired. .

[Problems to be Solved by the Invention] An object of the present invention is to solve the above-mentioned disadvantages of the prior art.

Means for Solving the Problems The present invention has been made to solve the above-mentioned problems, and a glass plate is arranged in a molding die, and a resin frame is integrally formed around the glass plate by an injection molding method. In the method of molding,
The glass plate is made of laminated glass, and only the front side portion serving as the design surface of the frame is formed by extrusion molding or injection molding, and this is placed together with the laminated glass in an elastic mold having a predetermined frame body cross-sectional shape. A method for producing a window glass with a frame, characterized by injection-molding at least the remaining back side portion by foam molding and integrally molding a resin frame around the laminated glass.

In the present invention, as the foamable resin material for injection molding the back side of the frame by foam molding, for example, a vinyl chloride resin containing a foaming agent, a polyamide resin, a polystyrene resin, a polypropylene resin, a polyethylene resin, a polyurethane resin. is there.

The front side portion of a resin frame such as a frame, a molding, a weather strip, or the like serving as a design surface is formed integrally with the periphery of the glass plate by extrusion molding or ordinary injection molding. It is molded by a molding die on the front side different from the die. The mold used for injection molding is cast iron,
A general metal mold such as stainless steel is used. Further, silicone rubber, ethylene propylene rubber, urethane rubber, silicone rubber, ethylene propylene rubber, urethane rubber, etc. are used as a mold having a front side portion and a glass plate disposed therein, and a frame body formed integrally with the periphery of the glass plate for foaming the back side portion. Rubber elastic bodies such as nitrile rubber and various synthetic resin elastomers are used. As the structure of the mold, not only the mold in which the entire mold is made of the rubber elastic body or the synthetic resin elastomer, but also a rubber elastic body or a synthetic resin elastomer is partially used on a surface in contact with the glass plate. It may be a structure type. Further, these elastic molds may be used for both the upper and lower molds. The front side mold may be an ordinary metal mold or a synthetic resin mold, and the elastic mold may be used only for the back side mold.

For example, as shown in FIG. 1, the front side portion 1 of a separately injected or extruded frame is placed in upper and lower elastic molds 4, 5, for example, a silicone rubber elastic mold so that the front side is on the front side of the frame. At the same time, the periphery of the glass plate 3 made of laminated glass is also placed in the upper and lower dies 4 and 5, and a resin material capable of forming a resin frame by foam molding is injected, and the glass plate 3 is formed by foam molding. The back side part 2 integrated with the front side part is molded to manufacture a window glass with a frame.

[Operation] A glass sheet that has only the same strength as a normal glass sheet that is not strengthened, such as laminated glass,
Even if the curvature error at the time of bending the glass plate is slight, it is easily broken by mold clamping, and is also easily broken at the time of injection molding by heat and high injection pressure, and at the same time, there is a problem of deterioration and deterioration of the interlayer film. Further, even in the case of tempered glass, when the shape is complicated and deep bending is performed, the precision of the bending is poor, the curvature error increases, and cracks are likely to occur during mold clamping. Therefore, regardless of whether it is reinforced or not, it is necessary to use a mold having elasticity capable of absorbing the curvature error of the glass plate in order to prevent glass breakage during mold clamping. However, such an elastic mold is inevitably weak in strength and cannot withstand high injection pressure, so that it can be molded only at low injection pressure. On the other hand, it is necessary to form the laminated glass at a low injection pressure so as not to cause glass breakage, deterioration and deterioration of the interlayer film during molding.

As a method of molding a thermoplastic resin at a low injection pressure, there is a foam molding method. The use of an elastic mold is possible by using foam molding, but the finish of the surface of a mold made of rubber or a synthetic resin elastomer is not always sufficient. Defects such as chipping and chipping are likely to occur, and this is reflected on the design surface of a molded frame or a frame such as a molding, resulting in a product defect.

By molding the front side corresponding to the design surface by extrusion molding method or injection molding method using a metal mold in advance as in the present invention, inserting this into the elastic mold together with the glass plate and foaming molding only the back side, Low-pressure molding can be performed without causing a product defect as described above. This makes it possible to prevent glass breakage during mold clamping and molding, and also prevent deterioration and deterioration of the interlayer film.

Furthermore, since the molding part on the front side acts as an elastic body as a secondary effect, it is possible to use a metal mold as a mold that contacts the front side during foam molding.

[Effect of the Invention] By manufacturing the front side portion and the back side portion of the frame body such as the frame body or the molding by different molding methods, that is, extrusion molding or ordinary injection molding and foam molding as in the present invention, Low-pressure molding using a thermoplastic resin enables mass production of molded products having good appearance. Further, from this, it is possible to prevent glass breakage at the time of mold clamping and molding, and deterioration and deterioration of the interlayer film of the laminated glass.

In addition, the weight of the frame such as the frame and the molding can be reduced by the foam molding.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing a mold used in one example of the present invention. DESCRIPTION OF SYMBOLS 1 ... Front part of frame (injection molding part) 2 ... Back part of frame (foam molding part) 3 ... Glass plate 4 ... Upper mold 5 ... Lower mold

Claims (1)

(57) [Claims] 1. A method of disposing a glass plate in a molding die and integrally molding a resin frame around the glass plate by an injection molding method, wherein the glass plate is made of laminated glass, and is provided with a design surface of the frame. Only the front side part is formed by extrusion molding or injection molding, and this is arranged together with laminated glass in an elastic mold having a predetermined frame body cross-sectional shape, and the remaining at least back side part is injection molded by foam molding, and laminated. A method for producing a window glass with a frame, comprising integrally molding a resin frame around the glass.