JP2017160444A - Adherend adhesive film, and optical component and industrial product having the same stuck thereto - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adherend adhesive film which prevents floating between an adherend adhesive layer and a cover film even when lowering an adhesive force of the adherend adhesive layer in a step of producing the adherend adhesive film, has an adherend adhesive layer having a smooth surface, can be lightly peeled when peeled from an adherend but comes in close contact with the adherend during use in the production step and protects the adherend, and causes less contamination on the adherend surface after the adherend adhesive film is peeled.SOLUTION: There is provided an adherend adhesive film 5 formed by laminating an adherend adhesive layer 2 formed from a silicone resin and having a smooth surface on at least one surface of a transparent substrate 1, where a thickness of the adherend adhesive layer 2 is 2-250 μm, a storage elastic modulus of the adherend adhesive layer 2 at 25°C is 1.0×10Pa to 5.0×10Pa, and a cover film 6 in which an adhesive layer 3 is formed on one surface of a base material 4 for protecting the surface of the adherend adhesive layer 2 is stuck to the surface of the adherend adhesive layer 2 through the adhesive layer 3.SELECTED DRAWING: Figure 1

Description

The present invention relates to a surface protective film for protecting the surface of various industrial products such as optical parts such as lenses, optical films such as polarizing plates, diffusion plates, and light guide plates, precision machines such as semiconductor-related equipment, and the like. More specifically, the present invention relates to a surface protective film that is in close contact with an adherend and can be lightly peeled during peeling. A surface protective film that adheres firmly to an adherend and protects the adherend, and after the surface protective film is peeled off, is less contaminated on the surface of the adherend, and an optical component and an industrial product on which the surface is adhered. It is to provide.
In addition, the surface protective film of the present invention is used in detail for image display on camera lenses, eyeglass lenses, vehicle headlamp lenses, optical components such as optical fibers, and various displays (PDP, LCD, organic EL, etc.). Body, lens array sheet, touch panel sheet, polarizing plate, diffuser plate, phase difference plate, various optical films such as light guide plate, stainless steel plate, metal plate such as aluminum plate, plastic plate such as acrylic plate, glass plate, etc. Surface protective films used for surface protection of materials and industrial materials, medical equipment, precision equipment such as semiconductor manufacturing related equipment, and the like.

  In many manufacturing processes of industrial products, surface protective films are used to protect the surface of industrial products from fouling and breakage. For example, when manufacturing and transporting optical parts such as display image display bodies, optical glass, and various optical films, a surface protective film is attached to the surface of the optical parts, and dirt and scratches on the surface in subsequent processes. It has been made to prevent sticking. In addition, product inspection such as appearance inspection of optical components such as various optical films is performed with the surface protective film adhered. Moreover, it may be handled for processes, such as performing an assembly process, with the surface protective film bonded to the surface of the display.

  In the structure of a general surface protective film according to the prior art, a pressure-sensitive adhesive layer having a slight adhesive force is provided on one side of a base material made of a flexible resin film. The pressure-sensitive adhesive layer used in the surface protective film is a layer having adhesive properties for adhering to the surface of a display, glass, various optical films, and the like. In addition, the adhesive layer is made slightly adhesive when the protective film bonded to the surface of the display surface, glass, various optical films, etc. is peeled off from the bonded surface after use. This is because it can be peeled off and there is no adhesive residue. Examples of the pressure-sensitive adhesive used for the surface protective film include various pressure-sensitive adhesives such as acrylic pressure-sensitive adhesive, urethane pressure-sensitive adhesive, and rubber-based pressure-sensitive adhesive, and adhesive resins such as polyethylene vinyl acetate resin.

By the way, in recent years, with the increase in size of displays, there is an increasing demand for a surface protective film that can be easily peeled off and easily handled even when the surface protective film is used on a large area display screen. . In response to the demand for making the surface protective film lightly peelable at the time of peeling, Patent Document 1 proposes a surface protective film having an adhesive layer containing an acrylic adhesive and a silicone compound. However, since the silicone compound is oily, there is a problem that the surface of the adherend is contaminated when the surface protective film is peeled off.
Further, after peeling off the surface protective film for the production process from the adherend, when the optical film is bonded to the surface of the adherend, or when the surface protective film for shipping is bonded, If there is a residue due to contamination on the surface, the adhesion between the surface of the adherend and the optical film or the surface protective film for shipping is reduced, and there is a problem in that it is easy to peel off.

Patent Document 2 proposes a smooth surface adhesion film in which a silicone layer that adheres to a smooth surface is provided on at least one surface of a film having a predetermined function. Those using a silicone resin as an adhesion layer with the adherend have a problem that the surface of the adherend is contaminated after the surface protective film is peeled off.
Further, after peeling off the surface protective film for the production process from the adherend, when the optical film is bonded to the surface of the adherend, or when the surface protective film for shipping is bonded, If there is a residue due to contamination on the surface, the adhesion between the surface of the adherend and the optical film or the surface protective film for shipping is reduced, and there is a problem in that it is easy to peel off.

  For this reason, in Patent Document 3, in order to reduce surface contamination of the adherend due to the adherend adherent layer, the separator film that adheres to the surface of the silicone layer that is the adherend adherent layer is replaced at least once. Has proposed. However, there is a problem that a complicated process for reattaching the separator film is required, and the degree to which the contamination property of the adherend adhesion layer is reduced is changed by increasing or decreasing the number of times the separator film is reattached.

  In addition, in the conventional surface protective film using a silicone resin for the adherend adhesion layer, when the adhesive force of the adhesion layer is lowered, the adhesion to the separator film is also reduced. The float is generated between the body adhesion layer and the cover film (in Japanese Patent Application Laid-Open No. 2003-259542), which is a film for protecting the surface of the body adhesion layer, and the resin forming the adherend adhesion layer of the floated part is deformed. There was a problem to do. In addition, if the adherend adherent layer is deformed, a phenomenon such as bubbles may occur when the surface protective film is pasted to the adherend, which may result in inadequate pasting. There was a problem that the appearance was deteriorated when combined, and the image on the display was distorted.

JP 2001-108982 A JP-A-10-95073 JP 2008-55858 A

  This invention is made | formed in view of the said situation, Comprising: Even if the adhesive force of a to-be-adhered body adhesion layer is reduced, a to-be-adhered body contact | adherence layer and its surface are protected in the process of manufacturing a surface protection film. It is a surface protection film that does not float between the cover film and the cover film, and has a adherend adhesion layer with a smooth surface, and can be lightly peeled off when peeled off from the adherend The surface protective film is a surface protective film that adheres firmly to the adherend and protects the adherend during use in the manufacturing process, and that the adherend surface is less contaminated after the surface protective film is peeled off. It is an object of the present invention to provide an optical component and an industrial product to which the optical device is attached.

  In order to solve the above-mentioned problems, the present invention provides a float between the adherend adhesion layer and the cover film in the process of producing the surface protective film even if the adhesion and adhesion to the adherend are weak. Without removing the silicone transfer component from the adherend adhesion layer, the cover film having the adhesive layer formed on one side of the substrate made of a synthetic resin film is used as the surface of the adherend adhesion layer of the surface protective film. The technical idea is to bond them to each other via the pressure-sensitive adhesive layer.

  In order to solve the above-mentioned problems, the present invention provides an adherend adhesion film comprising a silicone resin and a smooth adherend adhesion layer laminated on at least one surface of a transparent substrate, The thickness of the body adhesion layer is 2 to 250 μm, the center line average roughness Ra of the surface of the adherend adhesion layer is 0.05 to 1.2 μm, and is bonded to the adherend adhesion layer. Provided is an adherend adherent film characterized in that the silicone transfer component can be removed from the surface of the adherend adherent layer as the adhesive layer is peeled and removed.

Moreover, the cover film in which the said adhesive layer was formed in the single side | surface of a base material for protecting the surface of the said adherend adhesion layer is provided on the surface of the said adherend adhesion layer via the said adhesive layer. It is preferable that the silicone transfer component can be removed from the surface of the adherend adhesion layer as the cover film that has been bonded and bonded to the adherend adhesion layer is peeled and removed.
Moreover, it is preferable that the said adhesive layer of the said cover film consists of an acrylic adhesive.

Moreover, this invention provides the optical component formed by bonding said adherend adhesion film through the said adherend adhesion layer.
In addition, the present invention is an industrial product group consisting of a display, an optical film, a building material, an industrial material, a medical device, and a precision device in which the adherend adhesive film is bonded via the adherend adhesive layer. Any one selected industrial product is provided.

The surface protective film according to the present invention comprises a cover film having a pressure-sensitive adhesive layer formed on one side of a substrate made of a synthetic resin film for protecting the adherend adhesion layer on the surface of the adherend adhesion layer. It is pasted. As a result, even in a surface protective film having an adherend adhesion layer with very low adhesive strength and adherend adhesion, in the process of producing the surface protection film, the adhesion between the adherend adhesion layer and the cover film It is possible to stably obtain a surface protective film having an adherend adhesion layer having a smooth surface without causing floating.
In addition, when the silicone resin is used for the adherend adhesion layer, the problem of contamination of the adherend due to the migration of low molecular weight silicone is also a problem when the cover film is peeled and removed. The adhesive layer of the cover film on which is formed removes low molecular weight silicone exposed on the surface of the silicone resin, thereby reducing contamination of the adherend.
As a result, according to the present invention, the adherend adherent layer having a smooth surface is provided and can be peeled lightly at the time of peeling, but the adherend adheres firmly to the adherend during use in the production process. It is possible to provide a surface protective film that protects the adherend and that is less contaminated on the surface of the adherend after peeling off the surface protective film.

It is sectional drawing which shows the schematic structural example of the surface protection film of this invention. It is sectional drawing which shows the example of a form of use of the surface protection film of this invention.

Hereinafter, an embodiment of a surface protective film according to the present invention will be described based on the drawings.
FIG. 1 is a cross-sectional view showing an example of a surface protective film according to the present invention. The surface protective film 10 has an adherend adherent film 5 made of a silicone resin and laminated with an adherend adherent layer 2 having a smooth surface on at least one surface of the transparent substrate 1, and one surface of the substrate 4. It consists of the cover film 6 in which the adhesive layer 3 was formed. The adherend adhesion film 5 is provided with an adherend adhesion layer 2 on at least one surface of the transparent substrate 1. The cover film 6 is provided with an adhesive layer 3 on one side of a base material 4 made of a resin film or paper. The adherend adhesion film 5 and the cover film 6 are bonded to the surface of the adherend adhesion layer 2 so that the pressure-sensitive adhesive layer 3 is in contact therewith.

  The transparent substrate 1 of the surface protective film 10 according to the present invention is not particularly limited as long as it has transparency, but a plastic film having flexibility is preferably used. Thereby, the external appearance test | inspection of an optical component can be performed, for example, with the surface protection film sticking to the adherend of an optical component. As the plastic film used for the transparent substrate 1, a polyester film such as polyethylene terephthalate, polyethylene naphthalate, polyethylene isophthalate, or polybutylene terephthalate is preferably used. In addition to the polyester film, other plastic films can be used as long as they have necessary strength and optical suitability. The transparent substrate 1 may be an unstretched film, may be uniaxially or biaxially stretched, and may be a plastic film in which the stretch ratio and the angle in the axial direction formed with crystallization of the stretch are controlled. .

  Although there is no limitation in particular as the thickness of the transparent base material 1, For example, about 12-125 micrometers is preferable, and about 20-75 micrometers is especially more preferable. If the thickness of the transparent substrate 1 is 12 μm or less, the stiffness of the transparent substrate is weak and handling is difficult. On the other hand, when the thickness of the transparent substrate 1 exceeds 125 μm, the rigidity increases and handling becomes difficult, and the price is increased, which is economically disadvantageous. If necessary, the transparent substrate 1 may have an antifouling layer or antistatic layer on the surface opposite to the adherend adhesion layer 2 (the uppermost surface in FIGS. 1 and 2) for the purpose of preventing surface contamination. In addition, a hard coat layer for preventing damage can be laminated. In addition, the surface of the transparent substrate 1 in contact with the adherend adhesion layer 2 may be subjected to easy adhesion treatment such as corona discharge treatment or anchor coating treatment.

  The adherend adhesion layer 2 of the surface protective film 10 according to the present invention is made of a transparent silicone resin, and is preferably a solid at room temperature and crosslinked with a silicone polymer in order to suppress surface contamination of the adherend. Is done. The crosslinked form of the silicone polymer is an addition reaction type that is a reaction between Si-H groups and Si-vinyl groups, a condensation reaction type that is a reaction between Si-H groups and Si-OH groups, or a reaction between mercapto groups and vinyl groups. A known crosslinking reaction such as an enthiol reaction type, a cation polymerization type of an alicyclic epoxy group, or a peroxide curing type may be used. From the viewpoint of suppressing the transfer of silicone from the adherend adhesion layer 2 of the surface protective film to the adherend, an addition reaction type, an enethiol reaction type, or a cationic polymerization type is preferable.

  The silicone polymer before the cross-linking reaction includes a solvent type, an emulsion type, a solventless type, and the like as a product form, but a solvent type or a solventless type is preferable because it is used for optical applications.

The thickness of the silicone resin used for the adherend adhesion layer 2 of the surface protective film 10 according to the present invention is preferably 2 to 250 μm. When the thickness is less than 2 μm, the adhesion to the adherend is lowered, and when the thickness is 250 μm or more, it can be used as a surface protective film, but it is not preferable because the material cost is increased and the processability of the silicone resin is lowered. The thickness of the silicone resin used for the adherend adhesion layer 2 is particularly preferably about 5 to 30 μm from the viewpoint of adhesion to the adherend and production cost.
Moreover, the silicone resin layer which is the adherend adherence layer 2 needs to be transparent like the transparent substrate 1 constituting the adherend adherent film 5 of the surface protective film. The total light transmittance of the adherend adhesion film 5 is preferably 85% or more.
The adherend adhesion layer 2 is preferably rich in flexibility, and the storage elastic modulus is preferably about 1.0 × 10 ⁵ Pa to 5.0 × 10 ⁷ Pa at 25 ° C., for example. .
Further, the surface of the adherend adhesion layer 2 should be as smooth as possible with as few irregularities as possible in order to reduce the air layer generated between the adherend and the adherend adhesion layer 2 and stabilize the adhesion. Is preferred. Therefore, the surface of the adherend adherent layer 2 preferably has a surface centerline average roughness Ra of 0.05 to 1.2 μm, and the surface centerline average roughness Ra of 0.05 to 0.6 μm. It is more preferable that the center line average roughness Ra of the surface is 0.05 to 0.2 μm.

  Moreover, in the surface protective film 10 according to the present invention, setting the adhesive force / adhesiveness of the adherend adhesion layer 2 to the adherend to an appropriate value is that of the silicone resin used for the adherend adhesion layer 2. This is achieved by adjusting viscoelasticity and crosslink density. It is common to adjust the adhesive strength and adhesion by adjusting the amount of functional groups in the silicone polymer and the amount of crosslinking agent such as methyl hydrogen polysiloxane, but if necessary, Additives that are compatible with silicone polymers such as silicone resins and are solid at room temperature may be added.

  Moreover, in order to improve the adhesion between the transparent substrate 1 of the surface protective film 10 according to the present invention and the adherend adhesion layer 2 made of a silicone resin, a silane coupling agent or the like is added to the silicone resin as necessary. You may do it.

  In order to form the adherend adhesion layer 2 on the transparent substrate 1 of the surface protective film 10 according to the present invention, a method of laminating a silicone resin may be performed by a known method. In general, a comma coating method, a Mayer bar coating method, a gravure coating method, a reverse roll coating method, a slot die coating method, a curtain coating method, and the like can be given. The silicone resin coated on the transparent substrate 1 can be subjected to a curing reaction by a method such as heat curing, ultraviolet curing, or electron beam curing to form a silicone resin film.

  For the purpose of protecting the surface of the adherend adherent layer 2 made of a silicone resin of the surface protective film 10 according to the present invention and removing the free components of silicone transferred to the adherend. A cover film 6 having a pressure-sensitive adhesive layer 3 formed on one surface of a base material 4 is bonded to the surface of the adhesion layer 2. The cover film 6 is obtained by applying a pressure-sensitive adhesive to the base material 4 such as a plastic film or paper by a known method to form the pressure-sensitive adhesive layer 3.

  The adhesive strength of the adhesive used for the adhesive layer 3 of the cover film 6 is not particularly limited, and it can be used from slightly adhesive to strongly adhesive. Moreover, the application thickness of the pressure-sensitive adhesive layer 3 used for the cover film 6 is not particularly limited, but is preferably about 1 to 40 μm from the viewpoint of pressure-sensitive adhesive properties and cost.

Examples of the pressure-sensitive adhesive used for the cover film 6 include pressure-sensitive adhesives such as acrylic pressure-sensitive adhesive, urethane pressure-sensitive adhesive, and rubber-based pressure-sensitive adhesive, and adhesive resins such as polyethylene vinyl acetate resin. In order to remove the free component of silicone that migrates to the adherend from the surface of the adherend adherent layer 2, and to transfer the adhesive component from the adhesive layer 3 of the cover film 6 to the adherend adherent layer 2 In order to suppress, the adhesive used for the cover film 6 is more preferably an acrylic adhesive, a urethane adhesive, or a rubber adhesive.
The adhesive strength of the adhesive layer used for the cover film 6 is 0.05 to 20 N / 25 mm when measured at a peeling angle of 180 ° and a peeling speed of 300 mm / min with respect to the stainless steel plate in accordance with JISZ-0237. It is preferable that it is a grade. If the adhesive strength of the pressure-sensitive adhesive layer of the cover film 6 is 0.05 N / 25 mm or less, it is insufficient to remove the silicone transition component from the adherend adherent layer, and there is a concern that adherend contamination will increase. / 25 mm or more is not preferable because the peel force when peeling the cover film from the surface protective film becomes high and handling becomes difficult.

  The base material 4 used for the cover film 6 is a plastic film such as polyester, polyamide, polyethylene, polypropylene, polyvinyl chloride, polycarbonate, polyimide, fine paper, kraft paper, art coat paper, clay coat paper, glassine paper, etc. Any of these paper base materials and resin-laminated paper obtained by laminating polyethylene or polypropylene on the paper base materials can be used. Since the base material 4 used for the cover film 6 is peeled and removed, any of transparent, translucent, and opaque can be used.

  When the surface protective film 10 according to the present invention is used for optical applications, the base material 4 used for the cover film 6 is more than the paper base material on which paper dust is concerned that it adheres to the adherend. A substrate made of a plastic film is preferred. Further, in view of an appearance inspection process performed as a quality inspection of the surface protective film 10 itself, a polyester film having many excellent features such as high transparency is more preferable.

  In the case of use where the stripping voltage influences when peeling the cover film 6 from the surface protective film 10, the cover film 6 is removed by applying an antistatic agent to one or both sides of the substrate 4 of the cover film 6. It is possible to suppress the peeling voltage when peeling.

  As a method of bonding the cover film 6 to the adherend adhesion film 5 in which the adherend adhesion layer 2 is laminated on the transparent substrate 1 according to the present invention, a known method can be used. For example, a method in which a cover film 6 in which a pressure-sensitive adhesive layer 3 is laminated on a base material 4 in advance is bonded to the surface of an adherend adhesion layer 2 of an adherend adhesion film 5 via the pressure-sensitive adhesive layer 3. Any method of applying a pressure-sensitive adhesive on the adherend adhesion layer 2 of the adhesion film 5 and bonding the substrate 4 of the cover film 6 after the pressure-sensitive adhesive layer 3 is dried to complete the cover film 6 may be used.

In order to use the surface protective film according to the present invention for the adherend, the adherend adhesion film 5 obtained by peeling the cover film 6 from the surface protection film 10 is adhered to the adherend as shown in FIG. It is bonded to the adherend 7 through the layer 2.
Examples of the adherend 7 include camera lenses, eyeglass lenses, vehicle headlamp lenses, optical components such as optical fibers, image displays for various displays (PDP, LCD, organic EL, etc.), lens array sheets, touch panel sheets, and polarized light. Various optical films such as plates, diffusers, retardation plates and light guide plates, stainless steel plates, metal plates such as aluminum plates, plastic plates such as acrylic plates, glass plates, building materials and industrial materials, medical equipment, semiconductor manufacturing Precision equipment such as related equipment, etc.

Industrial products such as optical parts, displays, optical films, building materials, industrial materials, medical equipment, precision equipment, etc. according to the present invention are adhered to the adherend surface with adherend adherent films obtained from the surface protective film according to the present invention. Since they are combined, they can be peeled off lightly when peeled, but they are firmly attached to the adherend during use in the manufacturing process, and the adherend surface (preferably a smooth surface) is protected. Can be stored, inspected, transported, etc., and there is little contamination of the adherend surface after peeling off the adherend adhesion film.
The surface protective film according to the present invention can also include an adherend adhesion film in which adherend adhesion layers are laminated on both surfaces of a transparent substrate. In this case, two cover films for protecting the surface of the adherend adhesion layer can be used and bonded to each of the adherend adhesion layers on both sides of the adherend adhesion film.

  Next, the present invention will be further described with reference to examples.

(Preparation of the surface protective film of Example 1)
Dry curing of a cationic polymerization type silicone resin (5 parts by weight of POLY-201 made by Arakawa Chemical, 100 parts by weight of catalyst CAT-211) on one side of a polyethylene terephthalate (PET) resin film having a thickness of 50 μm thickness after was applied so that the 25 [mu] m, the accumulated light quantity 1000mJ / cm ² × ² times with ultraviolet ray irradiation device to UV irradiation treatment to form the adherend adhesion layer by curing the silicone resin. Thereafter, a cover film having an acrylic fine pressure-sensitive adhesive layer was bonded to the surface of the adherend adhesion layer made of a silicone resin via the fine pressure-sensitive adhesive layer to obtain a surface protective film of Example 1. . Here, the cover film has an acrylic adhesive [95/5 copolymer of 2-ethylhexyl acrylate and 2-hydroxyethyl acrylate, on one side of a polyethylene terephthalate (PET) resin film having a thickness of 38 μm, An isocyanate-based curing agent (Nippon Polyurethane Industry Co., Ltd., Coronate L-45, with 2 parts by weight added to 100 parts by weight of the main agent) mixed] is applied so that the thickness of the pressure-sensitive adhesive layer after drying is 25 μm. And dried and laminated in a hot air circulation oven at 100 ° C.

(Preparation of surface protective film of Example 2)
As a silicone resin, instead of a mercapto / vinyl reaction type silicone resin (mixed with X-62-7028A and X-62-7028B manufactured by Shin-Etsu Chemical Co., Ltd. at a ratio of 100/10), the thickness after drying and curing is 50 μm. The surface protective film of Example 2 was prepared in the same manner as in Example 1 except that the adherend adherent layer was formed as described above, and the cover film was prepared with a thickness of the adhesive layer of 15 μm. Obtained.

(Preparation of the surface protective film of Example 3)
Instead of an addition reaction type silicone resin (X-62-1873 manufactured by Shin-Etsu Chemical Co., Ltd. and catalyst PL-56 in a ratio of 100/2) as a silicone resin, circulating hot air at 120 ° C. instead of ultraviolet irradiation A surface protective film of Example 3 was obtained in the same manner as in Example 1 except that the adherend adhesion layer was formed by drying in an oven for 3 minutes.

(Preparation of surface protective film of Example 4)
A surface protective film of Example 4 was obtained in the same manner as in Example 3, except that the adherend adhesion layer was formed with a silicone resin coating thickness of 5 μm.

(Production of surface protective film of Example 5)
In addition to forming an adherend adhesion layer in place of an addition type silicone adhesive (X-40-3306 manufactured by Shin-Etsu Chemical Co., Ltd. and catalyst PL-50T in a ratio of 100 / 0.2) as a silicone resin Obtained a surface protective film of Example 5 in the same manner as Example 3.

(Preparation of surface protective film of Example 6)
Instead of an additional type of solvent-type silicone resin (Toray Dow Corning Silicone SD7223 and Catalyst SRX-212 Cat mixed at a ratio of 100 / 0.6), the silicone resin coating thickness is 2 μm. The adherend adherent layer was formed, and the cover film was prepared using an acrylic strong adhesive (Olivein BPS-5127, manufactured by Toyochem Co., Ltd.) with the thickness of the adhesive layer being 15 μm. Obtained the surface protection film of Example 6 like Example 3. FIG.

(Production of surface protective film of Example 7)
A surface protective film of Example 7 was obtained in the same manner as in Example 3, except that the thickness of the silicone resin applied was 250 μm, the drying time was 5 minutes, and the adherend adherent layer was formed.

(Preparation of the surface protective film of Example 8)
A cover film was prepared by using a strong rubber adhesive (Olivein BPS-2411, manufactured by Toyochem Co., Ltd.) as a replacement for the acrylic fine adhesive layer of the cover film, with a thickness of 15 μm. Obtained the surface protection film of Example 8 like Example 1. FIG.

(Surface protective film of Comparative Example 1)
A surface protective film of Comparative Example 1 was obtained in the same manner as in Example 1 except that a polyethylene terephthalate (PET) resin film having a thickness of 38 μm was used instead of the cover film of Example 1.

(Surface protective film of Comparative Example 2)
A surface protective film of Comparative Example 2 was obtained in the same manner as Example 3 except that a polyethylene terephthalate (PET) resin film having a thickness of 38 μm was used instead of the cover film of Example 3.

(Surface protective film of Comparative Example 3)
An adherend adhesion layer is formed with a silicone resin coating thickness of 1 μm, and an acrylic strong adhesive (Olivein BPS-5127 manufactured by Toyochem Co., Ltd.) is used as the cover film, and the adhesive layer thickness is 15 μm. A surface protective film of Comparative Example 3 was obtained in the same manner as in Example 3 except that a cover film was prepared.

(Surface protective film of Comparative Example 4)
Silicone resin was added to acrylic adhesive [95/5 copolymer of 2-ethylhexyl acrylate and 2-hydroxyethyl acrylate and isocyanate curing agent (manufactured by Nippon Polyurethane Industry, Coronate L-45, 100 parts by weight of main agent] In place of using a separator film in which an adherend adherent layer is formed instead of a mixture of 2 parts by weight added) and a silicone release agent is used as a cover film. In the same manner as in Example 3, the surface protective film of Comparative Example 4 was obtained.

The evaluation test method and test results according to the present invention will be described below.
(Adhesive strength of surface protective film)
The surface protective film is cut into a width of 25 mm to prepare a test piece of the surface protective film, and the cover film to be bonded is peeled off. A test piece of the surface protective film is bonded to the surface of the glass plate using a 2 kg rubber roller so that air bubbles do not enter. Thereafter, the film was allowed to stand for 1 hour in a test environment of 23 ° C. × 50% RH, and then peeled in the direction of 180 ° using a tensile tester at a speed of 300 mm / min, and measured as the adhesive strength.

<Wettability>
The surface protective film is cut into a test piece having a width dimension of 50 mm and a length dimension of 100 mm. The cover film to be bonded is peeled off, and the adherend adherent layer of the surface protective film is brought into close contact with the surface of the glass plate so as to be in contact with the width dimension 50 mm × length dimension 20 mm. Thereafter, the hand is released from the test piece of the surface protective film, and the elapsed time that the test piece is in close contact with the glass plate by its own weight is measured. The elapsed time during which the hand of the surface protective film was released and 90 mm in the length direction of the test piece was in close contact was defined as wettability.

<Contamination of adherend surface>
The surface protective film is cut into a test piece having a width dimension of 50 mm and a length dimension of 100 mm. The cover film is peeled off, and the surface of the polyethylene terephthalate (PET) resin film (T100-38 manufactured by Mitsubishi Plastics Co., Ltd.) with a thickness of 38 μm is protected from bubbles by using a 2 kg rubber roller. Bond a film specimen. Then, after leaving for 24 hours in a test environment of 23 ° C. × 50% RH, the test piece of the surface protective film was peeled off, and the water contact angle of the adherend surface on which the test piece of the surface protective film was in contact was determined. Measure using a contact angle meter. The degree of contamination of the adherend surface is determined by comparing with a blank (water contact angle of a PET film alone). The water contact angle of the blank PET film was 65 °. The contamination index (K) of the adherend surface is calculated by the following formula: K = (measured value of water contact angle with test piece ÷ 65−1) × 100. It means less pollution.

(Bonding appearance in surface protection film manufacturing process)
Using a small test coating device (product name: Test Coater, manufactured by Inoue Metal Industry Co., Ltd.), apply a silicone resin to the transparent substrate, dry it, and irradiate it with ultraviolet rays as necessary. Bond the film and wind it up. The appearance of the wound surface protective film is visually observed to confirm whether the cover film is lifted (the presence or absence of bubbles between the cover film and the adherend adhesion layer).

  About the surface protective films of Examples 1 to 8 and Comparative Examples 1 to 4, tests such as adhesive strength of the surface protective film, wettability, contamination of the adherend surface, bonding appearance in the surface protective film manufacturing process, etc. The results are shown in Tables 1-3.

The following can be understood from the test results shown in Tables 1 to 3.
From the test results of Examples 1 to 8, the adherend adherent layer of the surface protective film of the present invention has a very weak adhesive force, but no floating occurs in the production process of the surface protective film, and A surface protective film having excellent performance with small contamination on the adherend surface has been obtained.
On the other hand, in the comparative example 1 using only a PET film as a cover film for protecting the adherend adhesion layer of the surface protection film, in the production process of the surface protection film, the adhesion between the adherend adhesion layer and the PET film. In addition to the poor appearance of the surface protective film, the surface of the adherend is highly contaminated (bad result). Further, in Comparative Example 2 using a material having a slightly higher adhesive force to the adherend of the adherend adherent layer as compared with Comparative Example 1, the adherend is produced in the production process of the surface protective film. Although no floating occurred between the adhesion layer and the cover film, the contamination of the adherend surface was further increased.

  In Comparative Example 3 in which the thickness of the adherend adhesion layer of the surface protective film was 1 μm, the adherend adhesion layer did not adhere to the adherend, and the function as the surface protection film could not be achieved. Further, in Comparative Example 4 in which an acrylic slight adhesive was used for the adherend adhesion layer of the surface protective film, the adhesive force was high and the wettability to the adherend surface was also poor.

  As the uses of the surface protective film of the present invention, in detail, camera lenses, eyeglass lenses, vehicle headlamp lenses, optical components such as optical fibers, image displays of various displays (PDP, LCD, organic EL, etc.), Construction materials such as lens array sheets, touch panel sheets, polarizing plates, diffusion plates, retardation plates, light guide plates and other optical films, stainless steel plates, metal plates such as aluminum plates, plastic plates such as acrylic plates, glass plates, and the like Surface protective films used for surface protection of industrial materials, medical equipment, precision equipment such as semiconductor manufacturing related equipment, and the like. In particular, in the production process of optical products such as optical components, display surfaces, glass and various optical films, etc., it can be used to protect the surface by sticking to the surface of the optical product.

DESCRIPTION OF SYMBOLS 1 ... Transparent base material, 2 ... Adhering body adhesion layer, 3 ... Adhesive layer, 4 ... Base material, 5 ... Adhering body adhesion film, 6 ... Cover film, 7 ... Optical component (adhering body), 10 ... Surface protective film.

Claims (4)

An adherend adherent film comprising a silicone resin and a smooth adherend adherent layer laminated on at least one surface of a transparent substrate, wherein the adherend adherent layer has a thickness of 2 to 250 μm. The storage elastic modulus of the adherend adhesion layer is 1.0 × 10 ⁵ Pa to 5.0 × 10 ⁷ Pa at 25 ° C .;
A cover film in which a pressure-sensitive adhesive layer is formed on one surface of a substrate for protecting the surface of the adherend adhesion layer is bonded to the surface of the adherend adhesion layer via the pressure-sensitive adhesive layer. An adherend adherent film characterized by comprising:   The adherend adhesion film according to claim 1, wherein the pressure-sensitive adhesive layer of the cover film is made of an acrylic pressure-sensitive adhesive.   An optical component formed by bonding the adherend adhesion film after the cover film is peeled and removed from the adherend adhesion film according to claim 1 or 2 via the adherend adhesion layer.   A display in which the adherend adhesion film after the cover film is peeled and removed from the adherend adhesion film according to claim 1 or 2 is bonded via the adherend adhesion layer, optical Any one industrial product selected from the industrial product group consisting of films, building materials, industrial materials, medical equipment and precision equipment.

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