JPH02139213A - Method for forming a surface protective layer on synthetic resin lenses - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method of protecting a synthetic resin lens by forming a protective layer on the outer peripheral surface of the synthetic resin lens.

[Conventional technology]

For example, lenses for automobile lamps and lenses for decorative tools are widely made of synthetic resin.

In this case, there is a risk that oil dust or gravel will collide with the lens while the vehicle is running, causing damage to the lens.

To prevent such wear and tear, it is known to provide a protective layer on the surface of the lens.

Types of the above-mentioned protective layer include hard coatings with wear resistance to prevent scratches caused by minute oil dust, and soft coatings with buffering properties to prevent cracks caused by sand and gravel.

The conventional technique of hard coating and the conventional technique of soft coating are similar. FIG. 5 is an explanatory diagram of a conventional technique.

In the conventional example shown in FIG. 5, a lens 2 injection-molded from a synthetic resin material is placed on a receiving jig 1 and sprayed with a spray gun 3a to form a coating film.

The paints used for hard coating include acrylic UV paint and acrylic ink.

There are silicone-based paints and fluorine-based paints.

In addition, as a paint used for soft coating, there is a two-component urethane paint containing a polyol resin as a main ingredient and a curing agent (isocyanate resin) in a 1/4 weight ratio.

In the conventional example shown in FIG. 6, coating is performed by a curtain coater 4 using the same paint as in the above-mentioned conventional example.

[Problem to be solved by the invention]

As in the conventional example shown in FIG. 5 or FIG. 6, when trying to apply paint to form a protective layer (hard coating or soft coating) on an injection-molded synthetic resin lens 2, it becomes complicated after the lens injection molding. requires extensive processing steps.

For example, in the case of hard coating with UV paint.

Degreasing and cleaning process as a pre-treatment for painting, Step of setting lens 2 onto receiving jig 1.

Preheating and drying process.

It must go through a UV paint application process, a UV irradiation process, and a cooling process, and processing equipment for each of these processes is required, as well as transportation equipment between the processes.

In addition, in the case of soft coating using polyol resin and isocyanate resin, after lens injection molding, there is a pre-treatment process such as anti-static blowing, degreasing and cleaning process, and lens setting process.

Application process (usually requires repetition).

Heat drying process.

Requires cooling and standing steps, and requires equipment and conveyance equipment #S to process these steps.

Further, when painting with a spray gun 3a as shown in FIG. 5, a uniform coating film can be formed relatively easily while moving the spray gun 3a in the direction of arrow a to paint the front surface 2a of the lens 2. However, in order to paint the side surface 2bti of the lens 2, you must move the spray gun in the direction of the arrow and spray the paint from position 3b indicated by the imaginary line.Since this side surface 2b is slanted, the paint film will not form properly. Similar problems occur when a curtain coater 4 is used as shown in FIG. 6, which tends to cause problems such as flow, wrinkles, and uneven thickness while having fluidity.

The present invention has been made in view of the above-mentioned circumstances, and does not require any special surface treatment after the lens is injection molded with synthetic resin, and does not require any painting-related equipment attached to the lens injection molding equipment. The object of the present invention is to provide a method for forming a surface protective layer of a plastic lens, which can be applied to either hard coating or soft coating.

(Means for Solving Problem 111) A method for forming a surface protective layer according to the present invention was created to achieve the above object.

A thin layer (hard coating or soft coating) of a material that protects the lens is layered on the surface of a synthetic resin lens that is compatible with the synthetic resin that makes up the lens, and the layered member is It is molded under heat and pressure to form a planar shape that covers the outer surface of the lens, and the planar member is in-molded during injection molding of a synthetic resin lens.

[Effect]

According to the above configuration.

The process of constructing a thin layer of material to protect the lens on the surface of a synthetic resin lens can be done by forming a thin layer (coating film) on a flat film by painting, so it can be mass-produced at a specialized factory. Therefore, products of stable quality can be supplied at low cost.

There is no particular difficulty in forming the above-mentioned laminated member under heat and pressure into a shape that fits on the outer surface of the lens, since it is sufficient to press a planar laminated film into a planar shape.

One side of the above laminated film is compatible with the synthetic resin of the lens material.

Adheres well to lenses during in-mold molding of lenses.

Since one side of the laminated film is a protective film (hard coating or soft coating),
A protective layer is formed simultaneously with the completion of injection molding.

〔Example〕

1 to 4 show an embodiment of the method for forming a surface protective layer according to the present invention.

As shown in FIG. 2(A), a cured paint is sprayed by a curtain coater 4 onto the synthetic resin lens 5 which is compatible with the lens, and a cured paint film 6 is applied as shown in FIG. 2(B).
The cured film 7 is constructed by laminating the above.

In this example, polycarbonate or vinyl chloride was used as the film 5, and a cured coating film 6 having a thickness of 5 to 10 μm was layered to form a cured film 7.

The cured film 7 constructed as described in Section 2 above is sandwiched between the T-shape 8 and the H-shape 9 as shown in FIG. Pressure and heat molding was performed at 150°C for 30 seconds to 1 minute while applying a pressure of 15 to 301 Cg/d.

A molded film 7' was obtained as shown in FIG. 3(B).

Furthermore, as shown in FIG. 3(C), both ends are cut off with a cutter 10, leaving the front surface 7a and side surface 7b, to form a planar outer shell 11.

In the above operation, the cured coating film 6 is oriented toward a concave mold, and the film 5 is oriented toward a convex mold, as shown in FIG. 3(A).

As a result, the planar outer shell 11 (see FIG. 3(C)) becomes
The convex outer surface is a cured coating, and the concave inner surface is a compatible film.

As shown in FIG. 1(A), the outer shell 11 is molded into a mold (female).
12 are set, and a mold (male) 13 is fitted together as shown by the arrow d, and a lens 15 is injection molded from a synthetic resin material as shown in FIG. FIG. 4C shows a state in which the mold is opened, and FIG. 4 shows a cross section of the lens 15 as a product.

A compatible film 5 constituting the outer shell 11 is fused and fixed in contact with the lens material, and a cured coating film 6 covers the outside thereof.6 Although the above is an example of hard coating, soft coating is also possible. It can be done in the same way.

When applying a soft coating, for example, a polycarbonate film is used as the film 5, and an isocyanate resin in a weight ratio of 1/4 to the polyol resin,
Add a solvent for viscosity adjustment, stir well, and spray paint to form a soft coat coating with a thickness of 40 to 50 μm (not shown).
Configure. The subsequent steps are similar to the previous example (hard coating).

〔Effect of the invention〕

As clarified by the examples described above, when the method of the present invention is applied, the formation of the surface protective layer is completed in the state where the injection molding of the synthetic resin lens is processed.

There is no need for painting-related equipment attached to lens injection molding equipment (painting work can be mass-produced in advance at a specialized painting factory, and uniform quality can be easily obtained because it is a flat surface painting).

Moreover, the method of the present invention can be applied to both the formation of hard-coating protective layers as well as the formation of soft-coating protective layers.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the method for forming a surface protective layer according to the present invention. Figure 1 is a process diagram of lens injection molding work, and Figure 2 is a process diagram of painting work. Figure 3 is a process diagram for forming the outer shell member, and Figure 4 is a cross-sectional view of the product. FIG. 5 and FIG. 6 are explanatory diagrams of the prior art, respectively. 5...Film compatible with the lens, 6...
- Cured coating film, 7... Cured film, 7'... Molded cured film, 11... Outer shell member, 15
···lens.

Claims (1)

[Claims] 1. In the method of forming a protective layer covering the surface of a synthetic resin lens, the lens is protected by covering the surface of a synthetic resin film that is compatible with the synthetic resin constituting the lens. The layered synthetic resin film is molded under heat and pressure to form an outer shell member shaped to fit on the outer surface of the synthetic resin lens, and a mold for injection molding the synthetic resin lens is formed. A method for forming a surface protective layer of a synthetic resin lens, the method comprising: setting the outer shell member in a mold, and injection molding the synthetic resin lens.