JP5700342B2 - Protective sheet material for LCD screen - Google Patents

Description

  The present invention relates to an improvement in a protective sheet material for a liquid crystal screen for protecting a screen of a device having a liquid crystal screen such as a mobile phone and a personal computer.

Since liquid crystal screens such as mobile phones and personal computers are exposed to the outside, they are easily damaged by contact with nails or other objects, and thus a protective film is required.
In general, a transparent adhesive sheet or film is used as such a protective film, and an individual user such as a mobile phone purchases it separately and sticks it on its own. The purpose of protection for transportation and handling may be peeled off and adhered.

Further, by using a protective sheet or film, it may be difficult to see the liquid crystal screen due to light reflection or the like, and a sheet material considering antiglare properties has been proposed.
In particular, in order to prevent damage to the liquid crystal screen, a method of providing an impact buffer layer on the protective sheet is employed, and generally, a urethane-based resin layer having excellent elasticity is used for forming the impact buffer layer. .

  When the protective sheet material is attached to the liquid crystal screen, as shown in FIG. 3, generally, the urethane resin layer 11 of 200 to 250 microns is positioned in the uppermost layer, and the lower layer is 25 microns. An adhesive layer 12 of about 30 μm is positioned, a base material 13 made of synthetic resin of about 25 to 50 μm such as PET is positioned below it, and a silicone layer 14 of about 30 μm to 50 μm is positioned below it. In this lower layer, a peeling film material 15 that is peeled off when the liquid crystal screen is stuck is stuck.

As such a liquid crystal screen protective sheet material, for example, the following techniques are known.
Utility Model Registration No. 315538 JP 2009-209203 A JP 2009-288868 A

  The urethane-based resin described above has excellent elasticity and thus provides a large buffering effect against external force on the liquid crystal screen. However, the manufacturing process is complicated to form each layer, resulting in a very high cost. It was. That is, the urethane-based resin cannot be directly adhered to a foreign material such as PET, and an adhesive layer must be interposed.

  In addition, since urethane-based resin layer has a high repulsive force against impacts, the damping rate at the time of impact absorption is small (attenuation cycle is long). Therefore, for example, in the impact test by natural fall of a steel ball, liquid crystal It may be considered that it is likely to be damaged by repetitive impact (the liquid crystal screen side is also vibrated by the impact) when it rebounds high at the time of collision with the screen and is repeated a plurality of times.

  The present invention can greatly reduce the manufacturing cost of a protective sheet for protecting a screen by sticking to a liquid crystal screen, and has an impact absorption capacity equal to or higher than that of a protective sheet having a conventional urethane resin layer. It aims at providing the protective sheet material for liquid crystal screens which can be exhibited.

The protective sheet material for a liquid crystal screen according to the present invention is a protective sheet material that is used by pressure bonding to a liquid crystal screen in order to achieve the above-described object,
A transparent sheet-like base material made of synthetic resin (2), and one side surface (2A) of the base material (2), and a silicone layer (3) carrying the one side surface (3A),
The silicone layer (3) is composed of a recovery-retarded silicone prepared by mixing and kneading at least a silicone gel with silicone, and
The silicone layer has a thickness of 200 to 500 microns.

In the present invention, the liquid crystal screen refers to a liquid crystal screen used in an electronic device such as a mobile phone or a personal computer, and covers all those already in general use.
Moreover, although the transparent film base material of the present invention is used, a colored film having a degree that allows easy viewing of the liquid crystal screen may be used.

According to the present invention, a transparent sheet-like synthetic resin base material is used, but a conventional urethane-based resin layer is not used on the surface, but a silicone layer to be attached to a liquid crystal screen is added to silicone , at least silicone. It is composed of a recovery slow- acting silicone mixed with a gel and is not about 30 to 50 microns used for conventional adhesive purposes, but is significantly thicker, ie 200 to 500 microns. The present inventors have found that, while fulfilling the function of adhering silicone to the screen, the impact force can be absorbed greatly, and in fact, the impact mitigating action on the liquid crystal screen is not inferior to the conventional urethane resin layer.

When a steel ball is made to collide with the protective sheet material provided with the silicone layer having this thickness (steel ball drop test), a concave portion is temporarily formed on the surface, but is restored for a while. This indicates that the shock is absorbed at a stretch, not the buffer due to the elastic repulsion like the urethane type protective sheet material.
In this way, the silicone layer is not simply used for the purpose of merely sticking due to adhesiveness, but is a very simple solution means that the thickness is improved to at least four times that of the conventional one, In the past, it was found that a sufficient impact mitigating effect was obtained by a method that was not noticed or assumed in the past, and that a conventional four-layer (exfoliation film material using a urethane resin) was obtained. The protective sheet constructed from the above can be substantially composed of two layers, and the production cost can be greatly reduced.
Other specific advantages of the present invention will become apparent from the following description.

In carrying out the present invention, it is preferable that a release film material (1) is adhered to the other side surface of the silicone layer (3).
In this way, by sticking the release film material (1), in the case of personal use, there is no risk of dust adhering to the silicone layer (3) during transportation and sales, and it is attached to the liquid crystal screen. It can be peeled off when used.

Furthermore, it is preferable that the silicone layer (3) is composed of a silicone having a slow-retarding effect obtained by mixing at least a silicone gel with silicone. As described above, since it takes time to recover from the compression deformation, that is, to return to elasticity, compared to general silicone, the impact can be absorbed rather than elastically buffered.
And if the addition amount of a silicone gel is increased, since restoration delay effect will increase so much, the addition amount can be adjusted suitably.

Further, the base material (2) is subjected to surface treatment by any one of antireflection treatment, low reflection gloss treatment, blue light cut treatment, hard coat treatment, antibacterial treatment or a combination of at least two of them. It is preferable to consist of resin.
By such surface treatment, it is possible to exhibit the optical function and antibacterial function necessary as a screen protective sheet for liquid crystals while absorbing damage and preventing damage at low cost.

The expanded longitudinal cross-sectional view of the protective sheet material for liquid crystal screens concerning this invention. The expanded longitudinal cross-sectional view which shows one use condition of the protection sheet material for liquid crystal screens concerning this invention. The expanded longitudinal cross-sectional view of the protection sheet material for liquid crystal screens which shows a prior art.

A preferred embodiment of the protective sheet material for a liquid crystal screen according to the present invention will be described below in detail with reference to the drawings.
As shown in FIGS. 1 and 2, this liquid crystal screen protective sheet material is a liquid crystal screen, and in this embodiment, as an example, a protective sheet material for protecting the liquid crystal screen P by pressure bonding to a liquid crystal screen P of a mobile phone. is there.

  This protective sheet material includes a transparent sheet-like base material 2 made of synthetic resin, a silicone layer 3 having one side surface 3A carried on one side surface 2A of the base material 2, and the other side surface of the silicone layer 3. The silicone layer 3 is formed to a thickness of 300 microns here.

Here, a film made of PET (polyethylene terephthalate) (thickness up to about 25 microns: possible to about 50 microns) is used as the film material 1 for peeling. At the time of manufacture, a long product having a predetermined width is prepared and finally cut into the size of the target liquid crystal screen P.
As the peeling film material 1, an existing resin film such as OPP (polypropylene) or PVC (polyvinyl chloride) may be used.

  Here, as the film substrate 2 adhered and held on the liquid crystal screen P, a PET film (thickness of about 50 microns: a thickness of 25 microns thinner than this) may be used. Similarly, other existing resin films such as OPP (polypropylene) and PVC (polyvinyl chloride) may be used as the film substrate 2. And since the said film material for peeling 1 makes a pair, the same thing is used and the size is cut similarly.

  The silicone layer 3 is made of a recovery-retarded silicone prepared by mixing at least a silicone gel with silicone. This restoration slow-acting silicone layer 3 is supported. This silicone layer 3 is here 300 microns thick. Although this thickness was determined to be sufficient for buffering and sticking to the liquid crystal screen, it would be possible to implement even 1 mm depending on the type of the liquid crystal screen. Is obtained.

As a result of an impact test on a liquid crystal screen (collision of a 120 g steel ball due to a natural drop from 1 m) of the protective sheet material having a thickness of 300 microns of the silicone layer 3, 200 to 500 microns was found to be effective. .
On the other hand, when a 50 micron silicone layer was applied to the same base material and an impact test was performed under the same conditions, the liquid crystal screen was damaged.

The method for supporting the silicone layer 3 is a method for supporting silicone on a release film by extrusion of a silicone roll, and belongs to the prior art performed using an appropriate pliers, and thus detailed description thereof is omitted.
The restoration delay-acting silicone layer 3 is prepared by mixing at least silicone gel into silicone and kneading. By mixing this material, the restoration time for compression deformation is delayed. That is, if the addition amount of the silicone gel is increased, the recovery delay effect is increased accordingly.

  When the silicone gel was mixed with 10 parts by weight with respect to the silicone, 20 parts were mixed, and 30 parts were mixed, but the restoration time was about 30 seconds to 180 minutes. In this case, the delay time can be greatly reduced as compared with the case of 3 to 6 seconds. This means that the impact is not deformed as quickly as the urethane resin, but that the impact is absorbed and deformed, and the impact is absorbed so much.

  The substrate 2 is made of an antireflection treatment. This antireflection treatment uses a special polymer that diffuses light, but since it is a well-known technique, a detailed description is omitted here. Other examples of such surface treatment include low reflection gloss treatment, blue light cut treatment, hard coat treatment, and antibacterial treatment. The low reflection gloss treatment is a sheet having a polarizing filter function, and is also a known technique. Similarly, the blue light cut is a film or sheet developed to cut by focusing on light of a blue wavelength, and is already known. The hard coat is obtained by applying a hard coating to the surface of PET to achieve surface hardening, and is also commercially available. As antibacterial treatment has already been carried out in various fields, there are many organic and inorganic types, and any of them may be used.

  Since the protective sheet material for liquid crystal screens according to the present invention can be manufactured at a very low cost unlike conventional urethane-based materials, it can be applied not only to electronic devices such as mobile phones and personal computers, but also to liquid crystal screens for various uses. It can be done easily and has a wide range of applications.

1: Film material for peeling 2: Base material 2A: One side surface of base material 3: Silicone layer 3A: One side surface of silicone layer

Claims (2)

A protective sheet material that is used by applying pressure to a liquid crystal screen,
A transparent sheet-like base material made of synthetic resin (2), and one side surface (2A) of the base material (2), and a silicone layer (3) carrying the one side surface (3A),
The silicone layer (3) is composed of a recovery-retarded silicone prepared by mixing and kneading at least a silicone gel with silicone, and
The silicone layer is constructed to a thickness of 200 microns to 500 microns;
A protective sheet material for a liquid crystal screen characterized by the above.   The protective sheet material for a liquid crystal screen according to claim 1, wherein a peeling film (1) is adhered to the other side surface of the silicone layer (3).

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