JPH0354619B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a method of manufacturing decorative moldings.

Decorative moldings are used for the surfaces of side panels of automobiles, window frames, the edges of parts, and the edges of furniture. Of course, this type of molding has a major function of decoration, but
Not only that, but it also has the function of absorbing the impact of contact and protecting the other object.
From this point of view, plastics are often used these days.

For decorative moldings made of plastics, if they have the same cross-sectional shape, it is most efficient and economically advantageous to obtain them continuously by extrusion molding, and this is often used in practice. . However, the following problems have been pointed out when obtaining long plastic moldings by extrusion molding.

In other words, extrusion molding involves continuously extruding molten plastic through a die with a predetermined shape to shape it into a predetermined cross-sectional shape. Due to rapid pressure changes and variations in physical properties such as viscoelasticity of the molten plastic, the surface of the extrusion molded product becomes a finely uneven surface. For this reason, even if plastics are colored, they not only do not have a beautiful glossy color, but also a so-called whitening phenomenon occurs in which the plastics appear cloudy due to the diffuse reflection of light on the finely uneven surface.

This invention was proposed in view of the current situation, and its main purpose is to create beautiful moldings with excellent decorativeness, in particular:
A mold with a completely new concept that has protrusions made of a glossy transparent plastic layer formed on the top surface of the base, or a contrast between the glossy surface part of the transparent plastic and the matte surface part of the base surface. It is intended to provide a method for obtaining deings.

The present invention also proposes a method for obtaining a molding with excellent cushioning performance by forming a protrusion having a bulge on the surface of the molding.

Another object of the present invention is to provide a method that can easily, reliably, and efficiently obtain a molding with excellent decorative and cushioning properties as described above.

In order to achieve the above object, the present invention involves casting a thermosetting liquid plastic on the surface of a substrate to form a liquid plastic layer, and then forming a liquid plastic layer that still has fluidity. Between,
The gist of the present invention is to tilt the base body, cause liquid plastic to flow and deform, and then heat and harden the plastic to integrally form protrusions on the surface of the base body.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below along with embodiments with reference to the accompanying drawings.

Figure 1 of the accompanying drawings is a partial perspective view showing a decorative molding obtained by the present invention, particularly a protective molding to be attached to a side panel of an automobile, together with its cross section, and Figure 2 is a partial perspective view of a decorative molding obtained according to the present invention. FIG. 3 is a partial perspective view showing another example of a protective molding for use with its cross section; FIG.
FIG. 4 is a cross-sectional view of a state in which a plastic layer formed by casting liquid plastic is preheated;
Figure 5 is a cross-sectional view of the state in which the base body is tilted to cause the liquid plastic to flow and deform, Figure 6 is a cross-sectional view of the state in which the protruding part with the bulge has hardened, and Figure 7 shows the other figures. FIG. 3 is a cross-sectional view showing a liquid plastic layer and a tilted deformation state in an example of FIG.

As shown in FIGS. 1 and 2, a decorative molding 10 or 10A obtained by the method of the present invention has a base made of a plastic sheet 11, a plastic extrusion molded product 12, an injection molded product, or the like. , which is composed of a protrusion 20 made of a hardened portion of thermosetting liquid plastic formed on the surface of the base.

The protrusion 20 made of the hardened portion of the liquid plastic has a glossy, smooth and beautiful surface with a lens-like effect, and a portion of the surface is formed into a predetermined bulge 25 due to the movement of the resin. It is molded into a shape.

Next, embodiments of the method of the present invention will be described in detail with reference to the drawings from FIG. 3 onwards.

FIG. 3 shows a state in which a thermosetting liquid plastic 21 is flown and cast onto the surface 15 of the substrate 11 which is held horizontally.

First, let's talk about the base:
As mentioned above, the plastic sheet-like material 11
Alternatively, it is made of a molded product 12 of an appropriate shape obtained by known extrusion molding, injection molding, etc., and its materials include vinyl chloride resin, ABS resin,
Any suitable plastic material may be used, such as polyamide resin, polycarbonate resin, etc. Often colored or colored to enhance its decorative effect
Alternatively, printed decorations such as letters and patterns may be formed on the surface.

It goes without saying that the shape of the substrate can be arbitrary depending on the final shape of the molding, but the shape of the substrate surface 15 on which the liquid plastic is cast is
For example, it is preferable for the edges to be sharpened, such as the right-angled edge 19 shown in the figure, for the purpose of casting the liquid plastic, which will be described later.

Next, the liquid plastic 21 is thermosetting and usually transparent. For example, a liquid polyurethane composition composed of polyol and diisocyanate is a preferred material. These include appropriate catalysts for the purpose of accelerating or controlling the curing rate, and antioxidants, ultraviolet absorbers, and light stabilizers for the purpose of improving physical properties such as heat resistance, light resistance, or weather resistance of molded products. Used with adjuvants such as

Other useful liquid plastics include liquid acrylic resin compositions containing methyl methacrylate as a main component and epoxy resin compositions having epoxy groups in their molecules. Note that the liquid plastic may be colored and made transparent by mixing a dye or the like.

The liquid plastic 21 is continuously flowed down and cast from a nozzle 30 or the like onto the substrate strip surface 15 to form a liquid plastic layer 22.

Most preferably, the liquid plastic layer 22 is formed by utilizing the natural flow of the liquid and its surface tension. To this end, as described above and illustrated, the edge portion of the substrate surface 15 on which the liquid plastic layer 22 is to be formed is aligned with a right-angled edge 1.
It is recommended to use a sharp edge like 9.

The liquid plastic 21 is cast onto the substrate 15 by gravity flow of the liquid, and forms a curved surface that bulges due to its surface tension at the sharp edge 19, resulting in beautiful rounded edges 29.
A liquid plastic layer 22 is formed having the following properties.

The liquid plastic layer 22, while still fluid, is then caused to flow and deform by tilting the substrate 11.
Immediately after the liquid plastic 21 is cast, its fluidity is too high and it is difficult to mold it, so it is preferable to preheat it as shown in FIG. 4 so that the surface is slightly hardened. Heating may be performed by irradiating infrared rays with an infrared lamp 35 as shown, or may be introduced into a heating furnace.

The plastic layer 22 having fluidity is in a state where the liquid plastic itself is still fluid and deformable when it is in the middle of gelation. As shown in the figure, by tilting the base body 11, the gravity causes the base body 11 to flow in one direction and become biased, causing the bulge 2
5 is formed.

The inclination angle d of the base body 11 is appropriately determined depending on the fluidity of the liquid plastic layer 22 and the size of the bulge 25 to be formed.

The deformation of the plastic layer 22 is thus
This is caused by the natural fluidity of the formation of the thin wall portion 23 due to the inclination and the formation of the bulge portion 25 due to the portion that has moved from the thin wall portion.

The protrusions 20 that have been fluidly deformed into a predetermined shape are finally heated, hardened, and completely integrated with the base 11. This heating is also performed using an infrared lamp 35 or the like, similar to the preheating described above.

Note that this final heating may be performed simultaneously with the flow deformation step by tilting, as shown in FIG. This is because it may be preferable for molding to heat and harden the protrusions while maintaining the fluid state due to the inclination.

Each figure in FIG. 7 shows an embodiment in which a base body 12 having a bulge 13 at one side end is provided with a protrusion 20 having a bulge 25 at the other side end. In the figure, a shows the liquid plastic layer 22, and b shows the state of flow deformation due to inclination. In the figure, the edge of the base surface portion 15 on which the liquid plastic layer 22 is formed is formed at a right angle 19.

As illustrated and explained above, according to the method for manufacturing decorative moldings of the present invention, a thermosetting liquid plastic is cast on the surface of a substrate to form a liquid plastic layer, and then the liquid plastic layer is While the base body is still fluid, the base body is tilted, the liquid plastic is caused to flow and deform, and the ridges are integrally formed on the surface of the base body by heating and hardening the liquid plastic. Because of its characteristics, the molding is beautiful and has a novel concept with excellent decorative properties.In other words, the upper surface of the base plastic has a glossy glass-like clear surface, and the bulge has a natural flow. It has now become possible to easily, reliably, and efficiently obtain a beautiful molding with excellent decorativeness in which a protrusion having a shape is formed.

In particular, according to this invention, a part of the glossy glass-like clear surface is made into a bulge due to the natural fluidity of the resin, so it is not only novel in terms of design, but also has a cushioning effect. It is now possible to provide moldings with excellent properties and texture.

Furthermore, according to the invention, a conventional substrate strip, such as an extruded or injection molded article or a plastic sheet, is used to completely cover this upper surface or to expose a portion thereof. In contrast to the surface area formed by these moldings, beautiful ridges can be formed by casting and deforming the liquid plastic, making it possible to create innovative products using conventional materials. It can provide great advantages in the production of deings.

[Brief explanation of drawings]

Fig. 1 is a partial perspective view showing a decorative molding obtained by the present invention, particularly a protective molding to be attached to a side panel of an automobile, together with its cross section, and Fig. 2 is a protective molding for an automobile as well. FIG. 3 is a cross-sectional view showing a state in which liquid plastic is poured onto the surface of a substrate, and FIG. FIG. 5 is a cross-sectional view of the formed plastic layer being preheated; FIG. 5 is a cross-sectional view of the substrate being tilted to flow and deform the liquid plastic; FIG. 6 is a cross-sectional view of the formed plastic layer being preheated; FIG. 7 is a sectional view showing the liquid plastic layer in the cured state and the sloping deformation state in another embodiment. 10, 10A...Protective molding for automobiles, 11, 12... Base body, 19... Right angle edge, 2
0... Protruding portion made of a hardened surface of liquid plastic, 21... Liquid plastic, 22... Liquid striped plastic layer, 23... Thin wall portion, 25...
Bulge.

Claims (1)

[Scope of Claims] 1. A thermosetting liquid plastic is cast on the surface of a substrate to form a liquid plastic layer, and then, while the liquid plastic layer still has fluidity, the substrate is 1. A method for producing decorative moldings, which comprises: forming protrusions integrally on the surface of the substrate by tilting the substrate, causing the liquid plastic to flow and deform, and heating and hardening the same. 2. The method of manufacturing a decorative molding according to claim 1, wherein the liquid plastic layer is preheated after formation.