JP7667965B2 - Glasses lens seal - Google Patents

Description

The present invention relates to a seal for eyeglass lenses that is applied for the purpose of adding required functionality and is also reworkable (replaceable). Here, eyeglass lenses include not only those for vision correction but also non-prescription lenses in sunglasses, goggles, polarized eyeglasses, etc.

Recently, spectacle lenses made of a transparent resin base having an optically functional resin layer having various functions (performances), such as photochromic properties and specific wavelength absorption properties (cutting ultraviolet rays and blue light, etc.), are well known (Patent Document 1 [Abstract], [Claim 1], [Claim 3], [Fig. 1], [Fig. 4], etc., Patent Document 2 [Abstract], [Claim 1], [Fig. 1], etc.). It is also well known that in the case of spectacle lenses made of organic glass, scratch resistance is usually imparted by a hard coat (Patent Document 1, lines 19-21). Polarized spectacle lenses and sunglasses in which an optical film such as a polarizing film is embedded to impart polarization, etc. are also well known (Patent Document 1 [Claim 4], [Fig. 4], etc.).

The inventors are not aware of any inventions relating to materials that can be used in place of the above-mentioned functional resin layer, or that can easily add or restore functionality to the lens by the eyeglass user himself or at an eyeglass store when the functionality of the functional resin layer deteriorates over time.

In addition, reworkable (repositionable) double-sided protective adhesive sheets are well known for use on display screens of mobile phones, smartphones, televisions, etc., and even as privacy sheets for automobiles (Patent Document 3 [Claim 10], [0014], etc.; Patent Document 4 [Claim 17], [Claim 18], [0019]; Patent Document 5 [Claim 5], [0007], etc.).

International Publication No. 2003/008171 JP 2014-156067 A JP 2015-131945 A JP 2019-31610 A JP 2020-164761 A

However, when imparting these functions to lenses, the number of molding steps required to form the functional resin layer (including the polarizing film layer) is large, and it is difficult to maintain these functions for a long period of time. Therefore, when these functions deteriorate, it is usually necessary to replace the lens or reprocess it at the factory.

An object (object) of the present invention is to provide a seal for eyeglass lenses and a material therefor that eliminate the need to replace the lenses or reprocess them at a factory even if various functions of the lenses deteriorate.

The present invention solves the above problems by providing a seal for eyeglass lenses comprising the following invention specific features (configurations) (the reference symbols in FIG. 1 are attached).

A seal for eyeglass lenses 11 that adds functionality to eyeglass lenses,
The adhesive sheet has a double-sided adhesive laminate 13 and a functional film layer 15.
The double-sided adhesive laminate 13 includes a base layer 17 made of a non-stretched film, a weak adhesive layer 19 formed on one side of the base layer 17 and capable of being reattached (reworked) to an eyeglass lens, and a strong adhesive layer 21 formed on the other side of the base layer 17 and to which the functional film layer 19 is attached.
The thickness of each of the base material layer 17 and the functional film layer 15 is set so as not to impede the ability to conform to the spherical surface of the eyeglass lens.

The lens seal 11 having the above configuration is used by adhering it to a spectacle lens via a weak adhesive layer 19. In this case, since the base layer 17 of the double-sided adhesive laminate 13 is non-stretched, the configuration of the final stage ensures good conformability even when the lens is spherical, and excellent seal application workability is achieved. Then, used seals 11 whose functionality has deteriorated (functional film layer 15) are replaced with new lens seals 11. In this way, there is no need to buy new lenses or reprocess them at a factory.

Until now, there have been no documents describing such lens seals, and they have not appeared on the market. In the first place, the eyeglass industry has not even considered applying the adhesive tape for surface protection (screen protection material) used for electronic device screens such as smartphones to eyeglass lenses. The reasons for this are thought to be as follows.

The weak adhesive surface of a normal double-sided tape is intended to be attached to a smooth (flat) surface. For example, in the section "Effects of the Invention" of Patent Document 3, it is stated that "It has excellent adhesion to adherends having smooth surfaces such as glass surfaces and mirror surfaces, and is useful for protecting the surfaces of various components such as displays, touch panels, smartphones, tablet PCs, and thin film substrates." In addition, in the section "Effects of the Invention" of Patent Document 4, it is stated that "The present invention can provide, specifically, a display, more specifically, a flexible display." Note that the flexible display is intended to have a flat surface on the product when the sheet is attached, and is intended to have bending resistance thereafter. In other words, it is clear from the [Examples] and Table 1 showing the test results thereof that it is not intended to be attached to a fixed curved surface such as a spectacle lens.

In addition, in the column of [Effects of the Invention] of Patent Document 5, it is stated that "When the double-sided adhesive tape for screen protection disclosed in this specification is used, the occurrence of rainbow unevenness is reduced when it is attached to the screen of an electronic device, etc., and a screen protection member with excellent curved surface conformability can be realized." However, from the name of the invention, "double-sided adhesive tape for screen protection," it is clear that eyeglass lenses are not envisioned. Indeed, Patent Document 5 states that the tape is "excellent in curved surface conformability" as described above, but does not specify that the tape is also excellent in curved surface conformability to a spherical surface that is curved in all directions, such as an eyeglass lens. This is also supported by the fact that the edge lift test is measured by wrapping the tape around a cylinder with a diameter of 20 mm.

In the above configuration, it is preferable that the base layer of the double-sided adhesive laminate is formed of a non-stretched acrylic resin film, the strong adhesive layer is formed of an acrylic adhesive, and the weak adhesive layer is formed of a silicone adhesive. The former two configurations are excellent in transparency and low retardation, making it difficult to deteriorate the optical properties of the eyeglass lens. The latter configuration makes it easy to re-attach, and is excellent in attachment workability and reworkability.

In each of the above configurations, the functional film can be a hard coat film or a protective film, similar to the screen protection sheet. However, it is more preferable to use the functional film as an anti-fog film and the seal as an anti-fog film. There is no processing cost like the conventional water-repellent coat, and there is no need to deal with it every time it is used like a special cloth or anti-fog liquid, so the anti-fog property can be maintained for a required period of time, and when the anti-fog property decreases, it can be easily restored by simply replacing it.

In the above-mentioned configuration, the anti-fog film can be replaced with a light control film or a polarizing film. Compared to injection molding of a light control layer or embedding molding of a polarizing film layer, these functions can be significantly added to the eyeglass lens, and even if these functions are reduced, they can be easily restored by simply replacing the sheet.

In addition, the technical scope of the present invention also includes configurations in which the eyeglass lens stickers are packaged in predetermined quantities, and configurations in which oval paper of various sizes is included together with the material before it is cut into eyeglass lens stickers.

1A and 1B are a plan view and a cross-sectional view showing an example of a seal for eyeglass lenses according to the present invention;

Hereinafter, each component of the seal for eyeglass lenses of the present invention will be described in detail.

The material of the double-sided adhesive laminate 13 before cutting may be either tape-like or sheet-like. The material of both adhesive laminates 13 includes a base layer 17, a weak adhesive layer 19, and a strong adhesive layer 21, and if necessary, a release layer (liner) 23 is formed on the outside of the strong adhesive layer 21 and the weak adhesive layer 19. The double-sided adhesive laminate is not particularly limited as long as it has optical transparency and conformability to the spherical surface of a lens, and can be appropriately selected from commercially available double-sided tapes and sheets, but a double-sided adhesive laminate having the following configuration is preferable.

In general, the base layer 17 is preferably a non-stretched film (naturally transparent) from the viewpoint of conformability to the lens spherical surface and low retardation. Any film material may be used as long as it has flexibility capable of conforming to the lens spherical surface, such as acrylic, polycarbonate (PC), polyurethane (PU), cycloolefin polymer (COP), polyethylene terephthalate (PET), etc. In particular, an acrylic film is preferable because it is easy to obtain a film with high transmittance. The thickness of the base layer 17 is 5 to 60 μm, or even 10 to 40 μm, in the case of an acrylic film (see Patent Document 5 [0024]).

From the viewpoint of reworkability, it is desirable to form the weak adhesive layer with a silicone-based adhesive (see Patent Document 3 [Claim 1], Patent Document 4 [Claim 1], Patent Document 5 [Claim 1], [0023], etc.). In the case of a silicone-based adhesive layer, the thickness of the weak adhesive layer is, for example, 30 to 80 μm. The strong adhesive layer may be a urethane-based layer, etc., but in the case of an acrylic film as the base layer, it is desirable to form the strong adhesive layer with an acrylic adhesive, since this makes it easier to ensure adhesion between the base layer 17 and the functional film layer 15 (see Patent Document 3 [Claim 1], Patent Document 5 [0031], etc.). In the case of an acrylic adhesive, the thickness of this strong adhesive layer is, for example, 10 to 30 μm. And, the thickness of the "base layer 17 + weak adhesive layer 19 + strong adhesive layer 21" of the double-sided adhesive laminate 13 is desirably 50 to 200 μm, or even 50 to 100 μm. If it is too thick, it may be difficult to ensure the conformability to the lens spherical surface (see Patent Document 5 [0023]).

Various functional film layers are attached to the strong adhesive layer 21 of the double-sided adhesive laminate 11. When two or more types of functional film layers are used, a strong adhesive is applied between the functional film layers 15 and laminated.

Examples of the functional films include those having optical functions such as anti-fog, photochromic (light control), various filters (cutting ultraviolet rays, blue light, infrared rays, and specific wavelengths), and polarization, as well as protective films, antifouling films, antibacterial and virus films, etc. These functional films can be appropriately selected from products currently on the market or in the future. The base material of these functional films is not particularly limited as long as it is transparent and soft, and polyethylene terephthalate (PET), triacetyl cellulose (TAC), polycarbonate (PC), acrylic, cycloolefin polymer (COP), polyurethane, etc. can be used.

Examples and Comparative Examples will be described below. The double-sided pressure-sensitive adhesive laminate used in each Example and Comparative Example is described in "-Production of Double-sided Pressure-sensitive Adhesive Tape-" of Patent Document 5 [0030] and "0031".
The "set thickness" was adjusted to 20 μm for the unstretched acrylic substrate layer, 50 μm for the silicone-based weak adhesive layer, and 15 μm for the acrylic-based strong adhesive layer (total thickness of the three layers: 85 μm). The double-sided adhesive laminate used in the comparative example was the double-sided adhesive laminate of the example in which the substrate layer was a biaxially stretched PET substrate layer.

<Example and Comparative Example 1>
After cutting each double-sided laminate for the above examples and comparative examples to A4 size, the liner on the strong adhesive layer side was peeled off, and a commercially available TAC-based anti-fog film (thickness: 120 μm) similarly cut to A4 size was laminated using a commercially available laminator. After that, the anti-fog eyeglass stickers for each test were prepared by punching (cutting) into an elliptical shape (axis diameter: 40 mm, top and bottom diameter: 25 mm) shown in Figure 1 using a Thompson die. Then, the anti-fog eyeglass stickers were manually attached to the back surface (concave curved surface) of a commercially available eyeglass lens (made of resin) with approximately the same planar shape to prepare each test piece.

Example and Comparative Example 2
In Example 1 and Comparative Example 1, a test piece was prepared in the same manner, except that the commercially available anti-fog film was replaced with a commercially available light control film (thickness: 100 μm) and the light control eyeglasses sticker was attached to the front side of the eyeglass lens .

In Example 1 and Comparative Example 1, the commercially available anti-fog film was replaced with a commercially available anti-PVA polarizing film (thickness: 40 μm) , and a polarizing eyeglasses sticker was attached to the front side of the eyeglass lens . In the same manner, a test specimen was prepared.

The test pieces prepared above were subjected to the following tests.
(a) Haze Test:
The following haze value was measured using a haze meter in accordance with JIS-K-7136.
Haze (%) = Td/Tt x 100 (where Td: diffuse transmittance, Tt: total light transmittance)
(b) Test for seal lift:
24 hours after the preparation of the test piece, the state of lifting of the attached sticker was visually observed and evaluated according to the following criteria.
○: No floating at all, △: The outer circumference appears to be slightly floating (within 1 mm),
×: The area appears to be floating up to 1 mm or more inside the outer periphery.
(c) Test for the Occurrence of Wrinkles on Seal: Wrinkles 24 hours after the preparation of the test piece, the state of wrinkles on the applied seal was visually observed and evaluated according to the following criteria.
○: No wrinkles at all, △: Peripheral wrinkles (waviness) are observed,
×: Wrinkles (waviness) are observed on all surfaces.

From Table 1 showing the test results, it can be seen that the evaluation items of each Example are superior to each corresponding Comparative Example. That is, each Example has a small haze value and no peeling or wrinkling occurs compared to each corresponding Comparative Example, whereas each Comparative Example having the same functional film layer has a large haze value and peeling or wrinkling occurs on the attached sticker .

11: Eyeglass lens seal 13: Double-sided adhesive laminate 15: Functional film layer 17: Base material layer 19: Weak adhesive layer 21: Strong adhesive layer 23: Release layer (liner)

Claims (4)

A seal for eyeglass lenses that adds anti-fogging properties to eyeglass lenses,
A double-sided adhesive laminate and an anti-fog film layer are provided,
The double-sided adhesive laminate includes a base layer made of a non-stretched acrylic film, a weak adhesive layer formed on one side of the base layer and made of a silicone-based adhesive capable of being reattached to an eyeglass lens, and a strong adhesive layer on the other side of the base layer to which an anti-fog film is attached,
The anti-fog film is a triacetyl cellulose-based non-stretched film.
A seal for eyeglass lenses. 2. The seal for eyeglass lenses according to claim 1, which is formed by cutting a sealing material for eyeglass lenses, the sealing material having the same layer structure as that of the seal for eyeglass lenses according to claim 1, into an elliptical shape. 3. A seal set for eyeglass lenses, comprising a predetermined number of cut eyeglass lens seals according to claim 1 or 2 packed together. 3. A seal set for eyeglass lenses, comprising: a seal material for eyeglass lenses according to claim 2, the seal material being uncut; and oval-shaped papers of various sizes packed together in the seal set.