TWI518165B - Surface protection film, optical component and industrial products attached with the film - Google Patents

Description

Surface protection film and optical parts and industrial products adhered thereto

The present invention relates to a surface protective film for protecting the surface of various industrial products such as an optical component such as a lens, a polarizing plate, a diffusing plate, a light guide plate, or the like, a precision machine such as a semiconductor related device, and the like. In particular, the present invention relates to a surface protective film which can be adhered to an adherend and which can be easily peeled off when peeled off. The present invention provides a surface protective film which is closely adhered to an adherend to protect the adherend, and which is less contaminated by the surface of the adherend after peeling off the surface protective film, and an optical component or an industrial article to which the adhesive is attached.

Further, as the use of the surface protective film of the present invention, optical components such as a camera lens, an eyeglass lens, a vehicle headlight lens, and an optical fiber; and image display of various displays (PDP, LCD, organic EL, etc.) can be exemplified. Various optical films such as a lens array sheet, a touch panel, a polarizing plate, a diffusion plate, a phase difference plate, and a light guide plate; a metal plate such as a stainless steel plate or an aluminum plate; a plastic plate such as an acrylic plate; a glass plate or the like A surface protection film used for surface protection of building materials and precision instruments such as industrial materials, medical instruments, and semiconductor manufacturing related instruments.

In the manufacturing steps of most industrial products, a surface protective film for protecting the surface of an industrial product from contamination or breakage is used. For example, when manufacturing and transporting optical components such as video display bodies, optical glass, and various optical films of displays, The surface of the optical component is adhered to the surface protection film to prevent surface contamination and scratching in subsequent steps. Further, product inspection such as visual inspection of optical components such as various optical films can be performed in a state in which a surface protective film is adhered. Further, an assembly step or the like can be performed in a state where a surface protective film is bonded to the surface of the display, and it can be used for engineering.

In the prior art, a general surface protective film is provided with a microadhesive adhesive layer on one surface of a substrate made of a flexible resin film. The adhesive layer used for the surface protective film is, for example, a layer for adhesion to a surface of a display, glass, various optical films, or the like. In addition, when the adhesive film is made of a micro-adhesive property, the protective film adhered to the surface of the display, the surface of the glass, or various optical films, etc., can be peeled off smoothly after being peeled off from the bonding surface after use, and does not occur. Residue. Examples of the adhesive for the surface protective film include various adhesives such as an acrylic adhesive, an urethane-based adhesive, and a rubber-based adhesive, and an adhesive resin such as a polyvinyl acetate resin. .

In recent years, as the size of the display has increased, when the surface protective film is bonded to a large-area display screen, a surface protective film which can be easily peeled off and is easy to handle is also required. In the case of the surface protective film that can be easily peeled off at the time of peeling, Patent Document 1 proposes a surface protective film having an adhesive layer containing a polyfluorene-based compound in an acrylic adhesive. However, since the polyoxo compound is an oily property, the surface of the adherend is contaminated when the surface protective film is peeled off.

Further, when the surface protective film for the production step is peeled off from the adherend, the optical film is bonded to the surface of the adherend, or when the surface protective film for shipment is bonded, if the surface of the adherend is contaminated The residue causes a disadvantage that the adhesion between the surface of the adherend and the optical film or the surface protective film for shipment is lowered and peeled off.

Patent Document 2 proposes a smooth-faced dense film in which a polysilicon layer adhered to a smooth surface is provided on at least one surface of a film having a predetermined function. If the polyoxyxylene resin is used as a dense layer with the adherend, the surface of the adherend is contaminated after the surface protective film is peeled off.

In addition, when the surface protective film for the production step is peeled off from the adherend, when the optical film is bonded to the surface of the adherend, or when the surface protective film for shipment is bonded, if there is residue on the surface of the adherend due to contamination However, there is a disadvantage that the adhesion between the surface of the adherend and the optical film or the surface protective film for shipment is lowered and peeled off.

Therefore, in Patent Document 3, in order to reduce the surface contamination of the adherend caused by the adherend dense layer, it is proposed to at least re-attach one or more times to the surface of the polysilicon layer as the adherend dense layer. Isolation film. However, it requires a complicated re-adhesive step of the release film, and there is a problem that the degree of re-adhesion of the adhesion-adhesive layer is changed due to the increase or decrease in the number of re-adhesion of the separation film.

Further, in the conventional surface protection film using a polyoxyxylene resin in the adherend dense layer, if the adhesion of the adhesive layer is lowered, the adhesion to the release film is also lowered, and the step of manufacturing the surface protective film is also carried out. In the case where the adherend dense layer and the cover film which is a film for protecting the surface thereof (the separator film in Patent Document 3) are floated, the adherend portion of the adherend portion is formed. Problems such as resin deformation. Further, when the surface protective film is bonded to the adherend in the case where the surface protective film is deformed, the phenomenon of bubble entry occurs, and the film is not perfectly bonded, and the appearance is deteriorated when the surface protective film is bonded, and the display is deteriorated. The problem of image distortion.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2001-108982

[Patent Document 2] Japanese Patent Laid-Open No. Hei 10-95073

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2008-55858

The present invention has been made in view of the above circumstances, and provides a cover film which is a cover film for a film for protecting a surface thereof in the step of producing a surface protective film even in the step of manufacturing a surface protective film even if the adhesion of the adherend adhesive layer is lowered. A floating surface protection film does not occur between them. The present invention provides a surface protective film and an optical component and an industrial product which are adhered thereto, and the surface protective film has a smooth adherend layer which is easily peeled off when being peeled off from the adherend, and is used in a manufacturing step. The surface protective film is tightly adhered to the adherend and protects the adherend, and the surface of the adherend after peeling off the surface protective film is less contaminated.

In order to solve the above problems, the present invention is based on the following technical idea: in order to make the adhesion to the adherend and the adhesive force weak, in the step of manufacturing the surface protective film, the adhesive layer between the adherend and the cover film is not A cover film obtained by forming an adhesive layer on one surface of a base material formed of a synthetic resin film to remove the polyfluorene-transporting component from the adherend dense adhesion layer, passes through the adhesive layer Adhesive to the surface of the adherend of the surface protective film.

In order to solve the above problems, the present invention provides a surface protective film having a adherend-adhesive film obtained by laminating an adherend layer made of a polyoxymethylene resin on at least one side of a transparent substrate, A cover film that protects the surface of the adherend dense layer and has an adhesive layer formed on one surface of the substrate is adhered to the surface of the adherend adhesive layer through the adhesive layer.

Further, the thickness of the adherend dense layer is preferably 2 to 250 μm.

Further, the adhesive layer of the cover film is preferably made of an acrylic adhesive.

Moreover, the present invention provides an optical component in which the adherend-adhesive film obtained by peeling off the cover film from the surface protective film is bonded to the adherend-adhesive layer.

Moreover, the present invention provides any industrial product selected from the group of industrial products such as a display, an optical film, a building material, an industrial material, a medical instrument, a precision instrument, etc., which is adhered to the surface through the above-mentioned adherend adhesive layer The protective film is peeled off from the above-mentioned cover film to obtain the above-mentioned adherend dense film.

The surface protection film of the present invention is a cover film which is adhered to the surface of the adherend dense adhesive layer for protecting the adherend adhesive layer, and is adhered to one surface of the base material composed of the synthetic resin film. Obtained from the agent layer. Therefore, even in the step of manufacturing the surface protective film, the surface protective film having the adhesion and the adhesion of the adherend is very low, between the adherend adhesive layer and the cover film No floating occurs, and a surface protective film having a smooth adherend layer having a smooth surface can be stably produced.

Moreover, when a polyoxyxylene resin is used in the adherend dense layer, it is a problem that the migration of the low molecular weight polyfluorene gas causes contamination of the adherend, and when the cover film is peeled off, on one side. The adhesive layer forming the cover film with the adhesive layer removes the low molecular weight polyfluorene oxide exposed on the surface of the polyoxynoxy resin, thereby reducing the contamination of the adherend.

As a result, according to the present invention, it is possible to provide a surface protective film which has a smooth adherend layer which can be easily peeled off during peeling, and is used in a manufacturing step. In the middle, it is tightly adhered to the adherend to protect the adherend, and the surface of the adherend after peeling off the surface protective film is less polluted.

1‧‧‧Transparent substrate

2‧‧‧Adhesive tight layer

3‧‧‧Adhesive layer

4‧‧‧Substrate

5‧‧‧Adhesive dense film

6‧‧‧ Cover film

7‧‧‧Optical parts (adhesive)

10‧‧‧Surface protection film

Fig. 1 is a cross-sectional view showing a schematic configuration example of a surface protective film of the present invention.

Fig. 2 is a cross-sectional view showing an example of the use of the surface protective film of the present 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 of the present invention. The surface protective film 10 is composed of a adherend-adhesive film 5 obtained by laminating a surface of a transparent substrate 1 which is made of a silicone resin, and a surface of the substrate 4 The cover film 6 obtained by forming the adhesive layer 3 on one side is constituted. The adherend dense film 5 is provided with a adherend adhesive layer 2 on at least one surface of the transparent substrate 1. The cover film 6 is provided on one surface of a substrate 4 made of a resin film or paper, and is provided with an adhesive layer 3. The adherend adhesive film 5 and the cover film 6 are bonded in such a manner that the surface of the adherend adhesive layer 2 contacts the adhesive layer 3.

The transparent substrate 1 which is the surface protection film 10 of the present invention is not particularly limited as long as it has transparency. It is preferable to use a flexible plastic film. Thereby, for example, the appearance inspection of the optical component can be performed in a state in which the surface protective film is adhered to the adherend of the optical component. As the plastic film used for the transparent substrate 1, polyethylene terephthalate, polyethylene naphthalate, polyethylene isophthalate, polybutylene terephthalate are preferably used. A class of polyester film. In addition to the polyester film, other plastic films may be used as long as they have the necessary strength and optical suitability. The transparent substrate 1 may be a non-stretched film, or may be uniaxially or biaxially stretched, and may also be an axial direction angle controlled by controlling the stretching ratio or accompanying the extension crystallization. Plastic film.

The thickness of the transparent substrate 1 is not particularly limited. For example, the thickness is preferably about 12 to 125 μm, and more preferably about 20 to 75 μm. When the thickness of the transparent substrate 1 is 12 μm or less, the rigidity of the transparent substrate is weak and handling is difficult. Moreover, if the thickness of the transparent substrate 1 exceeds 125 μm, the rigidity is excessively increased and it becomes difficult to handle. In addition, the price becomes higher and economically disadvantageous. On the transparent substrate 1, an antifouling layer, an antistatic layer, which is laminated on the surface opposite to the adherend layer 2 (the uppermost surface of FIGS. 1 and 2) to prevent surface contamination, may be used. A hard coat that prevents scratches, etc. Further, an easy adhesion treatment such as a corona discharge treatment or a primer treatment may be performed on the surface of the transparent substrate 1 that is in contact with the adherend dense layer 2.

The adherend adhesive layer 2 of the surface protective film 10 of the present invention is composed of a transparent polyoxyl resin. In order to suppress surface contamination of the adherend, it is solid at normal temperature, and it is preferred to use a polyoxyl polymer. The substance obtained. The crosslinked form of the polyoxyl polymer may be an addition reaction type of a Si-H group reacted with a Si-vinyl group, a condensation reaction type of a Si-H group reacted with a Si-OH group, and an ene group reacted with a vinyl group and a vinyl group. A known crosslinking reaction substance such as an enethiol reaction type, a cationic polymerization type of an alicyclic epoxy group, or a peroxide curing type. From the viewpoint of suppressing the transfer of polyoxymethylene from the adherend dense layer 2 of the surface protective film to the adherend, it is preferably an addition reaction type, an ene-thiol reaction type, or a cationic polymerization type.

The polyoxymethylene polymer before the crosslinking reaction is in the form of a solvent, an emulsified or a solventless one, and is preferably a solvent-based or solvent-free type for use in optical applications and the like.

The polyoxynoxy resin used in the adherend 2 of the surface protective film 10 of the present invention preferably has a thickness of 2 to 250 μm. If the thickness is less than 2μm, the adherend The adhesion is reduced. When the thickness is 250 μm or more, it can be used as a surface protective film, but it is not preferable from the rise in material cost and the decrease in workability of the polyoxynoxy resin. The thickness of the polyoxymethylene resin used for the adherend dense layer 2 is particularly preferably about 5 to 30 μm from the viewpoint of adhesion to the adherend and production cost.

Further, the polyoxynoxy resin layer as the adherend-adhesive layer 2 must be transparent similarly to the transparent substrate 1 constituting the adherend-adhesive film 5 of the surface protective film. It is preferable that the total light transmittance of the adherend-adhesive film 5 is 85% or more.

Further, it is preferable that the adherend dense layer 2 is rich in flexibility, and as a storage elastic modulus, it is preferably about 1.0 × 10 ⁵ Pa to 5.0 × 10 ⁷ Pa at 25 ° C.

Further, in order to reduce the air layer generated between the adherend and the adherend dense layer 2, the adhesion is stabilized, and it is preferable that the surface of the adherend adhesive layer 2 is as small as possible to be uneven and smooth. Therefore, the surface of the adherend dense layer 2 preferably has a center line average roughness Ra of 0.05 to 1.2 μm. The center line average roughness Ra of the surface of the better system is 0.05 to 0.6 μm, and the center line average roughness Ra of the surface of the special system is 0.05 to 0.2 μm.

Further, in the surface protection film 10 of the present invention, in order to set the adhesion and adhesion of the adherend adhesive layer 2 to the adherend to a moderate value, the use of the adherend adhesive layer 2 is adjusted. Viscoelasticity or crosslink density of polyoxymethylene resin. In general, the amount of the functional group in the polyoxyl polymer and the amount of the crosslinking agent such as methyl hydrodiene polysiloxane are adjusted by addition and subtraction to adjust the adhesion and density. Sticky. Additives which are compatible and which are solid at normal temperature may also be added as needed.

Further, in order to improve the adhesion between the transparent substrate 1 of the surface protective film 10 of the present invention and the adherend dense layer 2 composed of the polyoxynoxy resin, a decane couple may be added to the polyoxyn resin as needed. Mixture, etc.

In order to form a adherend on the transparent substrate 1 of the surface protective film 10 of the present invention The dense layer 2, which is a method of laminating the polyoxynoxy resin, can be carried out by a known method. Generally, a comma coating method, a Meyer bar coating method, a gravure coating method, a reverse roll coating method, and a slot die coating method are mentioned. ), curtain coating method, and the like. The polyoxynoxy resin applied to the transparent substrate 1 can be hardened by a method such as heat curing, ultraviolet curing, or electron beam curing to form a polyoxyl resin film.

In order to protect the surface of the adherend dense layer 2 composed of the polyoxyn resin of the surface protective film 10 of the present invention, and to remove the free component of the polyfluorene oxygen which migrates to the adherend, it is attached to the adherend dense layer 2 The surface of the substrate 4 is bonded to the cover film 6 on which the adhesive layer 3 is formed on one side of the substrate 4. The cover film 6 is formed by applying an adhesive to a substrate 4 such as a plastic film or paper by a known method to form an adhesive layer 3.

The adhesive force of the adhesive used for the adhesive layer 3 of the cover film 6 is not particularly limited, and a substance that adheres from a slight adhesion to a strong adhesion can be used. Further, the coating thickness of the adhesive layer 3 used for the cover film 6 is not particularly limited, but from the viewpoint of adhesive properties and cost, the thickness is preferably about 1 to 40 μm.

In addition, examples of the adhesive used for the cover film 6 include an adhesive such as an acrylic adhesive, an urethane-based adhesive, and a rubber-based adhesive, and an adhesive resin such as a polyvinyl acetate resin. Wait. In order to remove the free component of the polyfluorene which migrates from the surface of the adherend dense layer 2 to the adherend, and to inhibit the migration of the adhesive component from the adhesive layer 3 of the cover film 6 to the adherend dense layer 2, The adhesive used for the cover film 6 is more preferably an acrylic adhesive, an urethane adhesive, or a rubber adhesive.

Further, the adhesion of the adhesive layer used for the cover film 6 is based on JISZ-0237, and the peeling angle is 180° for the stainless steel sheet, and the peeling speed is 300 mm/min. In the next measurement, it is preferably about 0.05 to 20 N/25 mm. When the adhesive force of the adhesive layer of the cover film 6 is 0.05 N/25 mm or less, the degree of removal of the polyoxo-oxygen migration component from the adherend dense layer becomes insufficient, and there is a concern that the contamination by the adherend increases. When the adhesive force of the adhesive layer of the cover film 6 is 20 N/25 mm or more, the peeling force when the cover film is peeled off from the surface protective film becomes high, and peeling becomes difficult, which is not preferable.

The substrate 4 used for the cover film 6 may be any of the following: a plastic film of polyester, polyamide, polyethylene, polypropylene, polyvinyl chloride, polycarbonate, polyimide, etc.; A paper substrate such as wood free paper, kraft paper, copper paper, clay coated paper, or cellophane; and a resin laminated paper obtained by laminating polyethylene or polypropylene on the paper substrate. Since the substrate 4 used for the cover film 6 is peeled off, it can be used transparent, translucent or opaque.

When the surface protection film 10 of the present invention is used for optical applications, as the substrate 4 used for the cover film 6, it is preferable to use a plastic paper substrate which is attached to the adherend with paper powder. A substrate composed of a film. Further, in consideration of the visual inspection step performed as the quality inspection of the surface protective film 10 itself, a polyester film having many excellent characteristics such as high transparency is more preferable.

When the peeling tape voltage when the cover film 6 is peeled off from the surface protective film 10 causes an influence on the application, the antistatic agent can be applied to one or both sides of the substrate 4 of the cover film 6, and the peeling of the cover film 6 can be suppressed. Stripping voltage.

In the present invention, a method in which the cover film 6 is bonded to the adherend-adhesive film 5 in which the adherend-adhesive layer 2 is laminated on the transparent substrate 1 can be used. A known method can be used. For example, a method of bonding the cover film 6 obtained by laminating the adhesive layer 3 on the substrate 4 to the surface of the adherend dense layer 2 of the adherend film 5 through the adhesive layer 3; Adhesive is applied to the adherend 2 of the adherent dense film 5, and is dried on the adhesive layer 3. After drying, the substrate 4 of the cover film 6 is bonded to complete the method of covering the film 6, and any of them may be used.

When the surface protective film of the present invention is bonded to the adherend, as shown in FIG. 2, the adherend dense film 5 obtained by peeling the cover film 6 from the surface protective film 10 is passed through the adherend adhesive layer 2 It is attached to the adherend 7.

Examples of the adherend 7 include optical components such as a camera lens, an eyeglass lens, a vehicle headlight lens, and an optical fiber; an image display body of various displays (PDP, LCD, organic EL, etc.); a lens array sheet and a touch lens; Various optical films such as a panel, a polarizing plate, a diffusing plate, a phase difference plate, and a light guiding plate; a metal plate such as a stainless steel plate or an aluminum plate; a plastic plate such as an acrylic plate; a building material such as a glass plate, and industrial materials and medical instruments Precision instruments such as semiconductor manufacturing related instruments.

The industrial product of the optical component, the display, the optical film, the building material, the industrial material, the medical instrument, the precision instrument, and the like according to the present invention is a bonded adhesive film obtained from the surface protective film of the present invention, and is adhered to the adhesive surface. As a result, it can be easily peeled off at the time of peeling, and it is tightly adhered to the adherend during use in the manufacturing step, and can be stored, inspected, and transported in a state of protecting the adhered surface (preferably a smooth surface). Etc., and the adhesion surface is less contaminated after peeling off the adherend dense film.

The surface protection film of the present invention may have a adherend dense film obtained by laminating a layer of a adherend on both sides of a transparent substrate. In this case, the cover film for protecting the surface of the adherend layer of the adherend is two sheets, and is adhered to each of the adherend adhesive layers on both sides of the adherend dense film.

[Examples]

Hereinafter, the present invention will be further described by way of examples.

(Production of Surface Protective Film of Example 1)

On one side of a polyethylene terephthalate (PET) resin film having a thickness of 50 μm, a cationic polymerization type polyoxynoxy resin (with respect to the main agent 100 weight) was applied in a thickness of 25 μm after dry hardening. 5 parts by weight of a portion of the Arakawa Chemical POLY-201, Catalyst CAT-211) was added, and a UV irradiation treatment was performed using a UV irradiation machine to accumulate a light amount of 1000 mJ/cm ² × 2 times to cure the polyoxyn resin to form a sticky body. Floor. Then, a cover film having an acrylic microadhesive layer was passed through the microadhesive layer to be bonded to the surface of the adherend dense layer made of polyoxymethylene resin to obtain a surface protective film of Example 1. Here, the cover film was applied to one surface of a polyethylene terephthalate (PET) resin film having a thickness of 38 μm, and an acrylic adhesive [acrylic acid] was applied so that the thickness of the adhesive layer after drying was 25 μm. a 95/5 copolymer of 2-ethylhexyl ester and 2-hydroxyethyl acrylate and an isocyanate-based curing agent (manufactured by Polyurethane Co., Ltd., CORONATE L-45, 2 parts by weight based on 100 parts by weight of the main component)] The laminate was dried in a hot air circulating oven at 100 °C.

(Production of Surface Protective Film of Example 2)

As a polyoxyxylene resin, it is substituted with a mercapto/vinyl reactive polyoxynoxy resin (available in a ratio of 100/10 in X-62-7028A and X-62-7028B manufactured by Shin-Etsu Chemical Co., Ltd.) to dry and harden. A surface protective film of Example 2 was obtained in the same manner as in Example 1 except that the adherend dense layer was formed to have a thickness of 50 μm to form a cover film having a thickness of 15 μm.

(Production of Surface Protective Film of Example 3)

In place of the ultraviolet irradiation, the polyoxynoxy resin is replaced by an addition reaction type polyfluorene resin (a mixture of X-62-1873 and catalyst PL-56 manufactured by Shin-Etsu Chemical Co., Ltd.). Drying in a hot air circulating oven at °C for 3 minutes to form A surface protective film of Example 3 was obtained in the same manner as in Example 1 except that the adhesive layer was adhered.

(Production 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 coating thickness of the polyoxyxene resin was 5 μm to form a adherend dense layer.

(Production of Surface Protective Film of Example 5)

As a polyoxyxene resin, a modified polyadone oxygen adhesive (a mixture of X-40-3306 manufactured by Shin-Etsu Chemical Co., Ltd. and catalyst PL-50T at a ratio of 100/0.2) is formed to form a adherend dense layer. A surface protective film of Example 5 was obtained in the same manner as in Example 3 except for the above.

(Production of Surface Protective Film of Example 6)

As a polyoxyxylene resin, it is replaced by an additive solvent-based polyoxynoxy resin (the mixture of SD7223 manufactured by Toray Dow-Corning Silicone and the catalyst SRX-212 Cat is mixed at a ratio of 100/0.6) to coat the thickness of the polyoxyxene resin. 2 μm was formed to form a adherend dense layer, and as a cover film, an acrylic strong adhesive (Oribain BPS-5127, manufactured by TOYO CHEM Co., Ltd.) was used, and the thickness of the adhesive layer was 15 μm to prepare a cover film. A surface protective film of Example 6 was obtained in the same manner as in Example 3 except for the above.

(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 coating thickness of the polyoxyxene resin was 250 μm and the drying time was 5 minutes to form a adherend dense layer.

(Production of Surface Protective Film of Example 8)

As a substitute for the acrylic microadhesive layer covering the film, a rubber type is used. A surface protective film of Example 8 was obtained in the same manner as in Example 1 except that the adhesive film (Oribain BPS-2411, manufactured by TOYO CHEM Co., Ltd.) was used to have a thickness of the adhesive layer of 15 μm. .

(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 in 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)

The coating thickness of the polyoxyxene resin was set to 1 μm to form a adherend dense layer, and an acrylic strong adhesive (Oribain BPS-5127, manufactured by TOYO CHEM Co., Ltd.) was used as the cover film, so that the thickness of the adhesive layer was A surface protective film of Comparative Example 3 was obtained in the same manner as in Example 3 except that a cover film was formed at 15 μm.

(surface protective film of Comparative Example 4)

Acrylic adhesive [95/5 copolymer of 2-ethylhexyl acrylate and 2-hydroxyethyl acrylate and isocyanate-based curing agent (CORONATE L-45, manufactured by Polyurethane Co., Ltd., Japan, added to 100 parts by weight of the main component) 2 parts by weight of the mixture], in place of the polyoxyl resin, to form a adherend-adhesive layer, and as a cover film, a release film which is subjected to a release treatment using a polyfluorene-based release agent, and other examples 3 Similarly, the surface protective film of Comparative Example 4 was obtained.

The method and test results of the evaluation test of the present invention are shown below.

(adhesion of surface protection film)

The surface protective film was cut into a test piece having a width of 25 mm and a surface protective film, and the cover film attached thereto was peeled off. A test piece of the surface protective film was attached to the surface of the glass plate by using a 2 kg rubber roller so as not to mix air bubbles. Then, it was allowed to stand in a test environment of 23 ° C × 50% RH for 1 hour, and then peeled off at a speed of 300 mm/min in a 180° direction using a tensile tester, and the peel strength measured was used as an adhesive force.

<wetness>

The surface protective film was cut into test pieces having a width of 50 mm and a length of 100 mm. The cover film attached thereto was peeled off, and the adherend layer of the surface protective film was adhered to the surface of the glass plate so as to be in contact with the width of 50 mm × the length of 20 mm. Thereafter, the hand was separated from the test piece of the surface protective film, and the elapsed time at which the test piece was adhered to the glass plate by its own weight was measured. The hand was separated from the test piece of the surface protective film, and the elapsed time until the 90 mm of the longitudinal direction of the test piece was reached was used as the wettability.

<Contamination of the surface of the adherend>

The surface protective film was cut into test pieces having a width of 50 mm and a length of 100 mm. The cover film attached thereto was peeled off, and the test piece of the surface protective film was attached to a polyethylene terephthalate (PET) resin film having a thickness of 38 μm by using a 2 kg rubber roller so as not to mix air bubbles (Mitsubishi Surface of T100-38 made by Resin Co., Ltd. Thereafter, after standing 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 surface of the adherend of the contact surface protective film test piece was measured using a contact angle meter. The degree of contamination of the surface of the adherend was determined by comparison with the blank group (water contact angle of the PET film alone). Water contact of blank PET film The angle is 65°. The pollution index (K) of the surface of the adherend is calculated by the calculation formula of K = (water contact angle measured value ÷ 65-1 on the test piece) × 100, and the smaller the value means the surface of the adherend Less polluted.

(The appearance of bonding in the manufacturing process of the surface protective film)

A small test coating device (manufactured by Inoue Metal Industries Co., Ltd., trade name test coater) is used, and a polyoxynoxy resin is applied onto a transparent substrate, dried, and subjected to ultraviolet irradiation as necessary, and then bonded to a predetermined cover film. And take it up. The appearance of the wound surface protective film was visually observed, and it was confirmed whether or not the cover film floated (with or without bubbles between the cover film and the adherend dense layer).

In the surface protective films of Examples 1 to 8 and Comparative Examples 1 to 4, the adhesion of the surface protective film, the wettability, the contamination of the surface of the adherend, and the manufacturing steps of the surface protective film are shown in Tables 1 to 3. Test results such as the appearance of the fit.

The test results shown in Tables 1 to 3 can be judged as follows.

From the test results of Examples 1 to 8, it is understood that although the adherend adhesive layer of the surface protective film of the present invention has a very weak adhesive force, it is possible to obtain no floating during the manufacturing process of the surface protective film, and has A surface protective film with excellent properties of small surface contamination of the adherend.

On the other hand, in Comparative Example 1 in which only the PET film was used instead of the cover film of the adherend-adhesive layer which protects the surface protective film, the adherend adhesive layer and the PET film occurred in the manufacturing process of the surface protective film. The floating between the surfaces is not only poor in appearance of the surface protective film, but also the contamination of the surface of the adherend is large (poor result). Further, in Comparative Example 2, in which a material having a slightly higher adherend of the adherend-adhesive layer of the surface protective film was used as compared with Comparative Example 1, in the manufacturing step of the surface protective film, although it did not occur The floating between the adherend dense layer and the cover film, but the contamination of the surface of the adherend becomes larger.

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

(industrial availability)

Examples of the use of the surface protective film of the present invention include optical components such as a camera lens, an eyeglass lens, a vehicle headlight lens, and an optical fiber; and an image display body of various displays (PDP, LCD, organic EL, etc.); Various optical films such as a lens array sheet, a touch panel, a polarizing plate, a diffusion plate, a phase difference plate, and a light guide plate; a metal plate such as a stainless steel plate or an aluminum plate; a plastic plate such as an acrylic plate; and a glass plate and the like material And surface protection films used for surface protection of industrial materials, medical instruments, precision instruments such as semiconductor manufacturing equipment, and the like. In particular, in the production steps of an optical component, a display surface, an optical product such as glass, various optical films, or the like, it can be adhered to the surface of the optical article or the like and used to protect the surface.

1‧‧‧Transparent substrate

2‧‧‧Adhesive tight layer

3‧‧‧Adhesive layer

4‧‧‧Substrate

5‧‧‧Adhesive dense film

6‧‧‧ Cover film

10‧‧‧Surface protection film

Claims (5)

A surface protective film comprising: a smooth adherend layer having a surface center line average roughness Ra of 0.05 to 1.2 μm, which is formed of a polyoxyxylene resin, is laminated on at least one surface of a transparent substrate a viscous film and a cover film having an adhesive layer formed on one side of the substrate; wherein the surface of the adherend layer is protected, and the adherend film is permeable to the viscous film The cover film which is adhered to the adherend when adhered to the adherend is adhered to the surface of the adherend dense layer through the adhesive layer, and the thickness of the adhered adhesive layer is 2~ The storage elastic modulus of the above-mentioned adherend dense layer of 250 μm is 1.0 × 10 ⁵ Pa to 5.0 × 10 ⁷ Pa at 25 ° C. For example, in the surface protection film of claim 1, wherein the K value of the contamination of the surface of the adherend of the adherend dense film is calculated by the following formula: the index of pollution K = (water on the test piece) The contact angle measurement value 测定 the water contact angle measurement value of the PET film alone was -1) × 100; and the above-mentioned contamination index K value was 20 or less. The surface protection film of claim 1 or 2, wherein the adhesive layer of the cover film is composed of an acrylic adhesive. An optical component obtained by adhering a surface-protective film peeling cover film obtained by any one of the first to third aspects of the patent application to the adherend-adhesive film. An industrial product selected from the group consisting of a display, an optical film, a building material, an industrial material, a medical instrument, a precision instrument, and the like, which is adhered to the patented scope by the adhesive layer. The surface protective film of any one of items 1 to 3 is obtained by peeling off the cover film obtained from the cover film.