JPH0359806B2 - - Google Patents

Description

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

Decorative moldings in the form of elongated strings are used on the surfaces of side panels of automobiles, the edges of window frames and other parts, and the edges of furniture.

Since this type of decorative molding usually has the same cross-sectional shape, it is most efficient and economically advantageous to obtain it by extrusion molding of plastics, and it is often used in practice.

However, when obtaining a long plastic molding by extrusion molding, the following problems have been pointed out in terms of decoration and molding process.

First, as a decorative problem, there is a phenomenon of diffused reflection due to the roughness of the molding surface. 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 changes in pressure and variations in physical properties such as viscoelasticity of the molten plastic, the surface of the extruded product has minute irregularities. For this reason, even if plastics are colored, they not only do not have a beautiful glossy color, but also appear cloudy due to the diffuse reflection of light on the finely uneven surface, resulting in what is called a whitening phenomenon.

Furthermore, as a processing problem, since the extrusion molded product is a continuous long product, it is necessary to cut it depending on the purpose. When cut, a sharp corner appears, so for decoration or safety reasons, a terminal cap may be attached to the corner, or the terminal may be integrally formed by injection molding or the like. I have to. However, such terminal processing not only necessitates a complicated process and impedes its efficiency, but also increases the processing cost of the product.

In addition to the above-mentioned extrusion molding, this type of molding can also be obtained by injection molding, etc.
There is a demand for products that are more beautiful and have new concepts.

This invention was proposed in view of the current situation, and its purpose is to provide a highly decorative plastic layer with a glossy glass-like clear surface on the upper surface. The objective is to provide a new way to obtain beautiful, new concept moldings.

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

Furthermore, in addition to the above-mentioned objects, the present invention also aims to provide a molding manufacturing method that eliminates the need for terminal processing at the edges, which is considered essential for this type of molding product. be.

In order to achieve the above-mentioned object, the present invention continuously flows and casts a thermosetting liquid plastic onto the surface of an elongated base strip along its longitudinal direction to form a liquid projection. The gist of the present invention is to form the protrusions integrally on the surface of the base strip by forming the strips and then heating to harden the liquid plastic.

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 partially omitted perspective view of a decorative molding obtained by the present invention, particularly a protective molding that is attached to a side panel of an automobile, and Figure 2 is a cross-sectional view of the end thereof. 3 is a cross-sectional view showing the side end portion of the same cut in the width direction, and FIG. 5
6 is a top view of a base strip having a curved shape, FIG. 6 is a top view of base strips having different widths in the longitudinal direction, and FIG. 7 is a sectional view showing a state in which liquid plastic is heated and hardened.

As shown in FIGS. 1 to 3, decorative molding 1 obtained by the method of the present invention
0 is a base strip 11 made of a plastic extrusion molded product, an injection molded product, a plastic sheet, etc., and a protrusion 2 made of a hardened surface of thermosetting liquid plastic formed on the base surface.
It is composed of 0.

The hardened surface 20 of the liquid plastic is a glossy, smooth, and beautiful surface with a length-like effect, and its edges 22, 23, and 24 are formed into rounded corners.

In the figure, reference numeral 30 is an adhesive layer for attaching this decorative molding to the vehicle body, and 31 is a protective paper for the adhesive layer. These can be formed simultaneously with the molding of the base strip 11 or after the manufacture of the present molding 10, if desired.

The base strip 11 is a molded product or a plastic sheet obtained by known extrusion molding or injection molding, and has an elongated shape. The base piece 11 is made of vinyl chloride resin, ABS resin,
Appropriate plastic materials such as polyamide resin, polycarbonate resin, etc. are used, and in many cases,
In order to enhance its decorative effect, it is colored, or printed decorations such as letters and patterns are formed on its surface.

It goes without saying that the shape of the base strip 11 can be arbitrary, but the edges of the strip surface 15 on which the liquid plastic is cast may be sharp edges, such as the right-angled edges 19 shown. is preferable in terms of casting of the liquid plastic, which will be described later.

FIG. 4 shows the thermosetting liquid plastic 21 being flowed down and cast onto the surface 15 of the base strip 11 along its length.

The liquid plastic 21 is attached to the substrate strip 11.
It is continuously flowed down in the longitudinal direction according to the shape of. In this case, the nozzle 40 through which the liquid plastic flows down may be moved in the direction of the arrow 41, or
Alternatively, the liquid plastic may flow down while the substrate strip 11 is being fed in the direction of the arrow 42, or both may be moved in alternating directions. The point is that it just needs to flow down continuously along the shape.

FIG. 5 shows a decorative molding 10A called a wheel arch molding that is attached to the edge of a tire house on the side of a car. When it has such a curved shape, it is attached along the semicircular base strip 11A. Liquid plastic flows down in a semicircular shape.

Furthermore, when the width in the longitudinal direction changes and it is necessary to change the amount of liquid plastic flowing down onto the upper surface of the substrate, as in the case of molding 10B shown in FIG. The feed rate of the nozzle or substrate strip may be varied. Of course, the amount of liquid plastic flowing down from the nozzle itself may be varied.

Most preferably, the liquid plastic surface is formed using natural flow of the liquid and its surface tension. To this end, as mentioned above, it is recommended that the edge of the strip surface 15 on which the hardened surface 20 of the liquid plastic is to be formed be sharpened, such as a right-angled edge 19.

The liquid plastic 21 is cast on the base strip 15 by natural liquid flow, and forms a curved surface that bulges due to its surface tension at the sharp edge 19, resulting in beautiful rounded edges 22, A liquid protrusion having 23 and 24 is formed.

If the surface of the substrate strip is a dull matte surface with minute irregularities, the finely uneven surface of the substrate strip is wetted and smoothed, just as ground glass is wetted with water. Coupled with the glossy and beautiful surface of the liquid plastic itself, an extremely smooth mirror-like surface is formed, and together with the rounded corners, a so-called lens-like beautiful surface effect appears.

The liquid plastic 21 used here is
It is thermosetting and usually transparent.
For example, a liquid polyurethane composition comprising a polyol and a diisocyanate as shown in the following formulation example 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. Adjuvants such as the following are mixed in appropriate amounts.

Examples [Liquid A (polyol type)] (Parts by weight) ●60 parts of polyester polyol with a molecular weight of 400 to 600●20 parts of trifunctional base polyether polyol with a molecular weight of 300 to 500●Trifunctional base polyether polyol with a molecular weight of 3000 to 4000 15 parts ●Ultraviolet absorber ("Tinuvin P" trade name of Nippon Ciba Geigy Co., Ltd.) 1 part ●Light stabilizer ("Sanol LS770" trade name of Sankyo Co., Ltd.)
1 part ●Antioxidant (“Sumilyzer NW” Sumitomo Chemical Co., Ltd.)
(trade name) 1 part ●Antioxidant ("Sumilyzer TL" trade name of Sumitomo Chemical Co., Ltd.) 1 part ●Catalyst (organotin catalyst) (dibutyltin dilaurate) 1 part ●Antifoaming agent ("Silicon L7002" Japan) Unicar Co., Ltd. product name) 1 part [Liquid B (isocyanate type) ●Prepolymer or blend of polypropylene glycol of isophorone diisocyanate
100 parts (in addition to this, hexamethylene diisocyanate,
Prepolymers or blends of polypropylene polypropylene glycol of trimethylxylylene diisocyanate, dicyclothexylmethane diisocyanate are used. ) In addition to the above-mentioned liquid polyurethane compositions, useful liquid plastics include liquid acrylic resin compositions containing methyl methacrylate as a main component, epoxy resin compositions containing epoxy groups in the molecule, and the like. Note that the liquid plastic may be colored by mixing a dye or the like.

After the liquid plastic 21 is cast onto the surface of the substrate strip 11, the liquid plastic 21 is heated and cured to integrate the substrate strip 11.

Heating is done using an infrared lamp 4 as shown in FIG.
In addition to being carried out by infrared irradiation according to No. 5, it may also be introduced into a heating furnace. The heating temperature depends on the material and physical properties of the liquid plastic, but is approximately 50 to 80°C.
It would be about that.

In addition, by heating the base strip 11 itself in this heating step, molding distortion that the base strip 11 has can be removed. In particular, when the base strip is an extrusion molded product, it is inevitable that stretching strain will occur in its longitudinal direction, but this stretching strain is restored by this heating. The substrate strip freed from strain will no longer shrink due to thermal conditions during subsequent use.

As illustrated and explained above, according to the method for producing decorative moldings of the present invention, thermosetting liquid plastic is continuously flowed down the surface of the elongated base strip along its longitudinal direction. The liquid plastic is then cast to form a liquid protrusion, and then heated to harden the liquid plastic, thereby forming the protrusion integrally on the surface of the base strip. From this, it is possible to easily and easily create beautiful moldings with excellent decorative properties, in other words, a plastic layer with a glossy glass-like clear surface is formed on the top surface of the base plastic. Now you can get it reliably and efficiently.

In particular, the present invention provides for continuous flow of the thermosetting liquid plastic along the longitudinal direction of a long, rather string-like molding with a length greater than its width; By going through the process of casting, it has the great advantage of being able to continuously obtain beautiful moldings with excellent decorative properties.

Furthermore, according to the present invention, beautiful rounded edges can be formed by casting liquid plastic, so terminals at the edges are essential for this type of molding product. This can provide many advantages in the production of decorative moldings, such as eliminating the need for processing.

[Brief explanation of drawings]

Figure 1 is a perspective view with a part omitted of a decorative molding obtained by the present invention, particularly a protective molding that is attached to a side panel of an automobile, and Figure 2 is a sectional view of its terminal. FIG. 3 is a cross-sectional view showing the side end portion of the same cut in the width direction.
Figure 4 is a cross-sectional view showing the state in which liquid plastic is poured onto the surface of a base strip, and is cast. Figure 5 is a top view of a curved base strip. A top view of the different substrate strips, and FIG. 7 is a cross-sectional view showing the state in which the liquid plastic is heated and hardened. 10...Protective molding for automobiles, 11...
...Substrate strip, 19...Right edge, 20...Hardened surface of liquid plastic, 21...Liquid plastic, 22, 23, 24...Rounded edge, 40...
...Nozzle, 45...Infrared lamp.

Claims (1)

[Scope of Claims] 1. Thermosetting liquid plastic is continuously flown down and cast on the surface of a long base strip along its longitudinal direction to form liquid protrusions; A method for manufacturing a decorative molding, comprising the step of integrally forming a protrusion on the surface of the base strip by heating and curing the liquid plastic. 2. The method for manufacturing a decorative molding according to claim 1, wherein the edge of the casting part of the liquid plastic under the substrate condition is formed by a sharp edge.