JPH0467503A - Illumination cover and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a high decorative effect by forming a paint film with less elongation than that of a thermoplastic resin plate on the surface of the translucent thermoplastic resin plate, and molding it into a recessed shape under heat. CONSTITUTION:An illumination apparatus has an illumination cover 2 formed with a plate material into a semi-spherical shape, and an illumination lamp 3 is stored at the center section of the inside. The illumination cover 2 is constituted of a substrate made of thermoplastic resin and a paint film 5 coated or printed on one face of it. Tortoise shell-shaped cracks 6 are generated on the paint film 5 when the illumination cover 2 is heat-molded, and the cracks 6 have a width W. Recessed grooves 6a are formed at portions of the substrate 4 corresponding to the cracks 6, and recessed grooves 10 are formed at portions of the inside face 7 of the illumination cover 2 corresponding to the cracks 6. A decorative effect in the room is obtained even when the illumination lamp 3 is not lighted, and the light is refracted and scattered on irregular faces when it is lighted, and a lighting decorative effect can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lighting cover and a method for manufacturing the same. More specifically, the present invention relates to covers used for lighting lights in homes, restaurants, and other stores.

[Conventional technology]

Lighting covers have traditionally been made of translucent thermoplastic resin molded into a bowl shape by vacuum or pressure, and their surfaces are also decorated with translucent inks and paints of various colors. .

In that case, it is convenient to print or apply the ink or paint in the form of a flat plate, so that it has good elongation characteristics for boat fishing and can sufficiently follow the elongation of the thermoplastic resin plate that makes up the base material of the cover. By using water-repellent inks and paints, printed single-color or multi-color coatings, letters, and patterns can be enlarged without cracking during thermoforming.

[Problem to be solved by the invention]

Although the conventional lighting cover has a beautiful finish, it is monotonous and lacks interest. In addition, cracks and unevenness are likely to occur unless the precision of the molding conditions is high.

The present invention is a lighting cover that can give a high decorative effect by making use of not only patterns created by ink, etc., but also cracks in the paint film, which were considered defects in the past, and unevenness on the surface of the base material caused by the cracks. The purpose is to provide

A further object of the present invention is to provide a manufacturing method that can easily manufacture such a lighting cover with a high decorative effect.

[Means to solve the problem]

The lighting cover of the present invention includes a base material formed by stretching and thermoforming a translucent thermoplastic resin plate, and a base material formed on at least one surface of the base material before the thermoforming to prevent elongation at the molding temperature. The coating film is smaller than the thermoplastic resin plate, and the coating film cracks during molding, and the surface of the base material is exposed at the bottom of the crack, and the thickness of the base material at that part is thinner. It is characterized by the presence of

As the coating film, a thermosetting resin ink or paint is usually used, but a thermoplastic one can also be used as long as it does not substantially stretch at the molding temperature. Further, although the coating film is usually colored, a transparent coating film may be used as long as only the irregularities need to be deformed.

The method for producing a lighting cover of the present invention involves forming a coating film with a smaller elongation than the thermoplastic resin plate on at least one surface of a translucent thermoplastic resin plate, and then applying vacuum to a concave surface under heating. Alternatively, it is characterized by air pressure molding.

[For production]

When vacuum forming or pressure forming a thermoplastic resin plate into a bowl shape, the elongation of the coating film is smaller than that of the base material, so during the forming process, the coating film may have a tortoise shell, leaf vein shape, wax shape, or completely unexpected shapes. Cracks in the shape and pattern occur. Therefore, each product has a different pattern, which increases the decorative effect of the product.

Furthermore, once a crack occurs in the coating film during molding, the coating film does not stretch much, and only the portion of the base material that corresponds to the crack is stretched significantly and becomes thinner. Therefore, the lighting cover can be changed to have a three-dimensional decorative effect with colored or colorless unevenness.

In other words, when an illumination cover with such an uneven pattern is attached to a lighting lamp and turned on, the light emitted from the lighting lamp becomes
It passes through the ink layer and its cracks, but since the parts corresponding to the cracks are concave on both sides,
The transmitted light is scattered beautifully.

Note that the coating film may be provided on either the convex side or the concave side of the base material.

The method for manufacturing the lighting cover of the present invention can basically be carried out using the same steps as conventional molding methods, only by changing the type of ink or paint that is printed or applied to the base material before molding.
It has the advantage that various crack patterns can be easily applied.

〔Example〕

Next, the lighting cover of the present invention and its manufacturing method will be explained with reference to the drawings.

FIG. 1 is a perspective view showing an example of a lighting fixture using the lighting cover of the present invention, FIG. 2 is an enlarged plan view of the round part of the lighting cover of FIG. 1, and FIG. ) Line sectional view, FIG. 4 is an enlarged plan view of part B1 of the lighting cover in FIG. FIG. 6 is a sectional view showing an example of an apparatus for forming a lighting cover from a plate material.

In FIG. 1, reference numeral (1) denotes a lighting device, which has a lighting cover (a) formed from a plate material into a substantially hemispherical shape, and a lighting lamp (3) is accommodated in the center inside the lighting cover (a).

As shown in FIG. 5, the lighting cover (2) consists of a base material (4) made of thermoplastic resin and a coating film (5) coated or printed on one surface thereof.

As shown in Figure 1, tortoiseshell-shaped cracks (6) have occurred in the paint film (5) during thermoforming of the lighting cover, as will be described later. ) has some width (W). A gentle concave groove (6a) is formed in the portion of the base material (4) that corresponds to the crack, and a gentle concave groove (6a) is also formed in the portion of the inner surface ('7) of the lighting cover that corresponds to the crack (6). A concave groove (concave groove) is formed (see Fig. 3).

When the lighting fixture (1) is constructed using such a lighting cover ('2J) as shown in Fig. 1, a variety of interior decoration effects can be achieved even when the lighting lamp (3) is not lit, and even when the lighting lamp (3) is not lit, it can be Then, the light shines on the uneven surface ((6a in Figure 3)
, 001) and is refracted and scattered, creating an unexpectedly beautiful lighting decoration effect.

Examples of the thermoplastic resin constituting the base material (4) include acrylic resins such as methyl methacrylate resin;
Olefin resins such as polyethylene and polypropylene, polycarbonate, vinyl chloride resins, and styrene resins are commonly used, of which acrylic resins and vinyl chloride resins are superior in moldability, light transmittance, and weather resistance. Particularly preferred.

The thickness of such a base material (4) before molding varies depending on the material, but is usually about 1.0 to 5.0 mm, preferably 2 mm.
．． It is about 0 to 3.01.

In addition, the elongation is 500℃ at a molding temperature of about 120 to 150℃.
% or more is preferable.

In addition, although it is common to use a transparent thermoplastic resin board, it is not limited to being transparent, and may be semi-transparent as long as it has enough light transmittance to be used as a lighting cover. Good too.

In addition, as the material for forming the coating film, thermosetting paints or inks such as epoxy, melamine, and silica, or reactively curing paints and inks such as polyester and urethane are preferably used. Thermoplastic materials such as acrylic, alkyd, and vinyl acetate materials can also be used as long as they do not substantially stretch. The thickness of the coating film is usually about 10 to 50".

Next, a method of manufacturing a lighting cover according to the present invention will be explained.

First, a plate-shaped base material (4) made of transparent thermoplastic resin as shown in FIG. 5 is prepared. Next, an ink or paint having a lower elongation than the thermoplastic resin is applied to the negative side of the base material (4).

When the ink or paint is dried, a hardened coating film (5) is formed on one surface of the base material.

As shown in FIG. 6, the plate material 02) on which the coating film has been formed is formed into a predetermined cover shape by thermoforming such as vacuum forming or pressure forming.

FIG. 6 illustrates an apparatus used for vacuum forming. Here, the former) is a bowl-shaped mold. A plate material 02) to be molded is attached to the upper end of the mold 01) to a tightening ring using a sealing material 04) and a clamp b. Next, the plate material 02) is heated uniformly or unevenly over the entire surface by the heater 0■, thereby softening it.

After that, or while softening, operate the vacuum pump 07) to connect the mold opening) to the plate material 02 through the intake hole Oa.
) The airtight space 09 defined by the space 09 is made to have a negative pressure.

Then, the softened plate material becomes a flat plate (indicated by the two-dot chain line).
From there, it is gradually stretched along the mold [111].

In that case, the coating film (5) cannot follow the elongation of the base material (4), and cracks (6) occur over the entire surface of the coating film (5) (see Figures 1 to 4).

After the crack occurs, the plate material 02) is released from the tensile force of the coating film (5) and further stretches. In that case, the part (8) of the base material (4) to which the paint film is attached is restrained by the paint film (5) and difficult to stretch, but the part (9) corresponding to the crack (6) in the paint film ) can easily grow without any other constraints.

Therefore, for the crack part (9), the other part (8)
(The part where the paint film is attached) As a result, regarding the thinned part (9), the inner surface (
7) There are also concave grooves (on the opposite side to the side where the paint film is attached).
A pattern of convexes and convexities is formed on the entire lighting cover.

There are cracks (cracks) on the surface of the lighting cover manufactured as described above.
6) produces a turtle shell pattern.

The pattern, including the unevenness, can be varied in various ways depending on the degree and direction of stretching of the plate material, the printing pattern of the coating film, or differences in the elongation characteristics of the cured coating film. For example, as the degree of stretching increases, the width of the crack increases;
The attached paint film has a pattern of scattered islands. Furthermore, if the elongation of the cured coating film is relatively large, there will be fewer cracks and the islands of the attached coating film will be large.

On the other hand, if the stretching direction is limited to one direction, cracks will mainly occur in a direction perpendicular to that direction.

By forming the coating film in the form of islands, stripes, or scattered dots in advance, various deformations such as undulations and waves can be imparted to the entire lighting cover.

According to the method described above, various patterns such as a turtle shape, a leaf vein shape, or a wax shape can be applied to the surface of the light cover.

Further, the degree of light transmission of the coating film can also be selected depending on the width of the crack to be generated. That is, if the area of the crack occupying the entire cover is large, a sufficient illumination effect can be obtained even by using a non-transparent coating film.

When a lighting cover manufactured in this way is attached to a lighting lamp and turned on, the light that passes through the uneven pattern is refracted and diffused, creating a lens effect (the cover erases the lamp image of the light source). This provides the beautiful pattern of the cover as well as soft illumination that is easy on the eyes.

Next, the illumination cover of the present invention will be described in more detail with reference to Examples.

Example 1 Acrylic paint containing a curing agent was applied to a thickness of 7 mm on the surface of an acrylic resin plate with a thickness of 2.0 mm, a length of 500 mm, and a width of 500 mm.
Silk screen printing was carried out to the extent of printing, and ultraviolet rays were irradiated for 0.7 hours.

Then, turn the coating side down (the side that will become concave after molding),
This product was set in a hemispherical pressure mold, heated in a far-infrared furnace so that the surface temperature was 140 to 160°C, and the inside of the mold was pressurized to 2 to 3 atmospheres. This state was maintained for 1 minute to produce a hemispherical lighting cover.

Near the top of the obtained lighting cover, a pattern was changed in which a quadrilateral island of about 2 x 3 mm was left and cracks with a width of 0.5 to 1.0 mm ran vertically and horizontally (see Fig. 2).

In addition, the pattern gradually changes toward the periphery of the lighting cover, and in the periphery of the lighting cover, a long and narrow island with a width of about 0.2n extends in the circumferential direction, and a groove with a width of about OJmm runs parallel to it. There are cracks (see Figure 4).

In the middle part, many deformed islands such as triangular and pentagonal shapes were observed. Also, the overall width is wider than the crack (0,8
~1.2+am) cracks ran diagonally, and the entire structure resembled a map of a densely populated residential area.

Example 2 A melamine-based paint was applied to an acrylic resin plate with a thickness of 2.0 mm, a length of 330 m++*, and a width of 330 mm, and was cured.

With the hardened side as the bottom surface (the side that becomes convex after molding),
This product is placed in a hemispherical vacuum mold, heated with a far-infrared heater to a surface temperature of 150 to 170°C, and maintained at negative pressure in the mold for 1 minute to produce a hemispherical lighting cover. did.

Near the top of the resulting lighting cover, a pattern was changed in which cracks with a width of about 0.5 m+s ran horizontally and vertically, leaving behind a quadrilateral island measuring about 1.0 x 2.0 square meters (see Figure 2).

In addition, the pattern gradually changes toward the periphery of the lighting cover, and in the periphery of the lighting cover, there are elongated islands with a width of about 0.5 mm extending in the circumferential direction, and parallel grooves with a width of 0.3 mm. The crack is about the same size as the crack (see Figure 4).

In the middle part, many deformed islands such as triangular and pentagonal shapes were observed. In addition, the overall width is wider than the crack (0,5
~1. omm) cracks running diagonally, and the overall pattern was similar to that in the case of air pressure forming described above. In general, the closer to the circumference than the top, the less elongation of the material occurs, so the width of the crack tends to become smaller.

〔Effect of the invention〕

According to the lighting cover of the present invention, in addition to the beauty of the crack pattern itself in the paint film, the unevenness caused by the cracks refracts and scatters light to exhibit a lens effect, resulting in a high decorative effect.

Further, according to the method for manufacturing a lighting cover of the present invention, by simply forming a coating film in advance, it is possible to easily form a beautiful crack pattern on the lighting cover at the same time as thermoforming. Another advantage is that each item can have a different pattern, and can also have a variety of unexpected patterns.

B) is an enlarged plan view of the section, FIG. 5 is a partially cutaway perspective view showing an embodiment of the thermoplastic resin plate material used for the lighting cover of the present invention, and FIG. 6 is an apparatus for molding the lighting cover from the plate material. It is a sectional view showing an example.

(Main symbols on drawings) (2): Lighting cover (4) Two base materials (5): Paint film (6): Crack (6a)00): Groove 01): Molding mold 02): Plate material QQ, heater

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an example of a lighting fixture using the lighting cover of the present invention, Fig. 2 is an enlarged plan view of the hole in the lighting cover of Fig. 1, and Fig. 3 is l-■ in Fig. 2). Line sectional view, Figure 4 is the patent applicant for the lighting cover in Figure 1 Aalubi Tobra Co., Ltd. 'A'1 Figure t4-i2 Figure 3 'i5 Figure

Claims (1)

[Scope of Claims] 1. A base material formed by thermoforming a translucent thermoplastic resin plate while stretching it, and a base material formed on at least one surface of the base material before the thermoforming to prevent elongation at the molding temperature. The coating film is smaller than the thermoplastic resin plate, and the coating film cracks during molding, and the surface of the base material is exposed at the bottom of the crack, and the thickness of the base material becomes thinner at that part. lighting cover. 2. The lighting cover according to claim 1, wherein the coating film is a thermosetting resin coating film. 3. The lighting cover according to claim 1, wherein the coating film is colored. 4. A method for producing a lighting cover, in which a coating film with a lower elongation than that of the thermoplastic resin plate is formed on at least one surface of a translucent thermoplastic resin plate, and the coating film is further vacuum- or pressure-formed into a concave shape under heating. . 5. The manufacturing method according to claim 4, wherein the coating film is a thermosetting coating film.