JP2020105479A - Protective film, protective film with adhesive layer, and transparent film with protective film - Google Patents

Abstract

To provide a protective film capable of improving antiblocking property of a transparent film containing a cyclic olefinic resin, and capable of inspecting appearance of the transparent film in a state laminated on the transparent film.SOLUTION: Provided is a peelable protective film used for protecting a transparent film by laminating on the transparent film containing a cyclic olefinic resin, in which the protective film contains the cyclic olefinic resin and a styrene-based elastomer, the protective film has surface roughness Ra of a surface on a side opposite to the protective film side of 7 nm or larger, the protective film has the surface roughness Rz of a surface on a side opposite to a side of the transparent film of 47 nm or larger, and the protective film has the haze of 10% or smaller.SELECTED DRAWING: None

Description

The present invention relates to a protective film, a protective film with an adhesive layer, and a transparent film with a protective film.

BACKGROUND ART Conventionally, various optical films have been used for various optical applications. For example, in image display devices such as liquid crystal display devices and EL display devices, liquid crystal substrates, polarizing films, etc. have optical transparency and heat resistance. An excellent transparent resin substrate is used.

For example, Patent Document 1 discloses an optical transparent material containing a cyclic olefin-based addition polymer having a reactive silyl group having a specific structure as a material forming such a transparent resin substrate.

JP, 2003-212927, A

The transparent film containing the cyclic olefin-based resin as described in Patent Document 1 has both excellent transparency and heat resistance and can be suitably used as an optical film or the like.

A transparent film containing a cyclic olefin resin is required to be wound into a roll, manufactured and distributed. However, when a transparent film containing a cyclic olefin resin is wound into a roll, the transparent films adhere to each other, which makes it difficult to unwind from the roll (that is, the antiblocking property is poor).

As a method for solving the problem of the anti-blocking property of the transparent film containing a cyclic olefin resin, for example, a method of subjecting the transparent film to a surface treatment or laminating a protective film can be considered.

However, if the transparent film is subjected to a surface treatment in order to solve the problem of anti-blocking property, there is a possibility that various optical characteristics required as an optical film or the like may be affected.

Further, in the manufacturing process of the transparent film and the unwinding process, a visual inspection is performed. Therefore, if the present inventors can enhance the anti-blocking property by laminating it on a transparent film containing a cyclic olefin resin, and further, if it is possible to perform an appearance inspection in a state where the protective film is laminated on the transparent film. The production efficiency of a transparent film containing a cyclic olefin resin and a product using the transparent film is improved.

Under such circumstances, the present invention can improve the anti-blocking property of a transparent film containing a cyclic olefin-based resin, and protect the transparent film in a state of being laminated on the transparent film, which enables visual inspection. The main purpose is to provide a film. Further, the present invention also aims to provide a protective film with an adhesive layer and a transparent film with a protective film, which use the protective film.

The present inventor has conducted extensive studies in order to solve the above-mentioned problems of the conventional technology. As a result, it is a peelable protective film laminated on a transparent film containing a cyclic olefin resin and used for protecting the transparent film, which contains a cyclic olefin resin and a styrene elastomer and has a transparent film side. After setting the surface roughness Ra, Rz of the surface on the opposite side to a predetermined value or more, and further setting the haze to less than the predetermined value, the anti-blocking property of the transparent film containing a cyclic olefin resin is improved. It has been found that the transparent film can be improved and the appearance of the transparent film can be inspected while being laminated on the transparent film. The present invention is an invention completed through further studies based on such findings.

That is, the present invention provides the inventions of the following modes.
Item 1. Laminated on a transparent film containing a cyclic olefin-based resin, used to protect the transparent film, a peelable protective film,
The protective film contains a cyclic olefin resin and a styrene elastomer,
The surface roughness Ra of the surface of the protective film opposite to the transparent film side is 7 nm or more,
The surface roughness Rz of the surface of the protective film opposite to the transparent film side is 47 nm or more,
The protective film has a haze of 10% or less.
Item 2. Item 2. The protective film according to Item 1, wherein the content of the styrene elastomer contained in the protective film is less than 20% by mass.
Item 3. Item 3. The protective film according to Item 1 or 2, wherein the styrene content of the styrene elastomer is 15% by mass or more.
Item 4. Item 4. A protective film with an adhesive layer, wherein at least an adhesive layer is laminated on the surface of the protective film of any one of Items 1 to 3 on the transparent film side.
Item 5. Item 1. A transparent transparent film with a protective film, wherein at least a pressure-sensitive adhesive layer and a transparent film containing a cyclic olefin resin are laminated in this order on the surface of the protective film of the protective film according to any one of items 1 to 3. the film.

ADVANTAGE OF THE INVENTION According to this invention, the anti-blocking property of the transparent film containing a cyclic olefin resin can be improved, and the protective film which enables the visual inspection of the transparent film in the state laminated|stacked on the said transparent film is provided. be able to. Moreover, according to this invention, the protective film with an adhesive layer using the said protective film, and the transparent film with a protective film can also be provided.

It is a schematic diagram of a protective film. It is a schematic diagram of a protective film with an adhesive layer. It is a schematic diagram of a transparent film with a protective film.

The protective film of the present invention is laminated on a transparent film containing a cyclic olefin resin (hereinafter, may be simply referred to as “transparent film”) to be used for protecting the transparent film. The protective film of the present invention is releasably laminated from a transparent film containing a cyclic olefin resin. The protective film of the present invention contains a cyclic olefin resin and a styrene elastomer. In the protective film of the present invention, the surface roughness Ra of the surface opposite to the transparent film side is 7 nm or more, and the surface roughness Rz of the surface opposite to the transparent film side is 47 nm or more. Is. Furthermore, the protective film of the present invention has a haze of 10% or less. The protective film of the present invention, by satisfying these constitutions, the anti-blocking property of the transparent film containing the cyclic olefin resin (specifically, the anti-blocking property of the transparent film with the protective film of the present invention). It is possible to improve the appearance of the transparent film, and it is possible to inspect the appearance of the transparent film while being laminated on the transparent film.

As described above, appearance inspection and the like are performed in the transparent film manufacturing process and the unwinding process. Therefore, the anti-blocking property can be enhanced by laminating it on a transparent film containing a cyclic olefin resin, and further, if the appearance inspection can be performed in a state where the protective film is laminated on the transparent film, the cyclic olefin resin is It can be said that the production efficiency of the transparent film including the product and the product using the transparent film is improved. Since the protective film of the present invention enables visual inspection of the transparent film in a state of being laminated on the transparent film, it improves productivity of the transparent film, and further improves productivity of products using the transparent film. Can contribute.

Hereinafter, the protective film, the protective film with an adhesive layer, and the transparent film with a protective film of the present invention will be described in detail.

In addition, in this specification, the numerical value connected by "-" means the numerical range which includes the numerical value before and behind "-" as a lower limit and an upper limit. When a plurality of lower limit values and a plurality of upper limit values are described separately, arbitrary lower limit values and upper limit values can be selected and connected by "...".

1. Protective Film The protective film of the present invention is a peelable protective film that is laminated on a transparent film containing a cyclic olefin resin and used to protect the transparent film. Specifically, the protective film of the present invention is used for protecting the transparent film in the production, distribution process, etc. of the transparent film containing a cyclic olefin resin, and when the transparent film is used as an optical film or the like. , Peeled from the transparent film. As will be described later, the protective film of the present invention may be laminated on a transparent film via an adhesive layer and used together with the adhesive layer so as to be peeled off from the transparent film.

The protective film of the present invention contains a cyclic olefin resin and a styrene elastomer. The cyclic olefin-based resin and the styrene-based elastomer contained in the protective film of the present invention may be of one type, respectively, or may be of two or more types.

The protective film of the present invention is laminated on a transparent film containing a cyclic olefin resin and is used for protecting the transparent film, and therefore, the protective film needs to contain the cyclic olefin resin. By including a cyclic olefin resin in the protective film, in a laminate laminated with a transparent film containing a cyclic olefin resin, the physical properties such as the heat shrinkage rate of the protective film and the transparent film become the same, resulting in defects during manufacturing. (For example, curling due to the difference in heat shrinkage) is suppressed.

The cyclic olefin-based resin is a polymer compound having a carbon-carbon bond in the main chain and having a cyclic hydrocarbon structure in at least a part of the main chain. This cyclic hydrocarbon structure is introduced by using a compound (cyclic olefin) having at least one olefinic double bond in the cyclic hydrocarbon structure, as represented by norbornene or tetracyclododecene, as a monomer. To be done.

The cyclic olefin-based resin is produced from the production method thereof by the addition (co)polymer of a cyclic olefin or its hydrogenated product, the addition copolymer of a cyclic olefin and an α-olefin or its hydrogenated product, and the ring-opening (co ) Polymers or hydrogenated products thereof.

Examples of the cyclic olefin include a monocyclic olefin such as cyclopentene, cyclohexene, cyclooctene, cyclopentadiene, and 1,3-cyclohexadiene, and other polycyclic olefins, which may be used alone or in combination of two or more kinds. be able to. In particular, it is preferable to use bicyclo[2.2.1]hept-2-ene (conventional name: norbornene) alone.

Specific examples of the α-olefin copolymerizable with the cyclic olefin include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene and 3 Examples thereof include ethylene or α-olefin having 2 to 20 carbon atoms, preferably 2 to 8 carbon atoms such as -ethyl-1-pentene and 4-methyl-1-pentene. These α-olefins may be used alone or in combination of two or more, but ethylene is preferably used alone.

Among the above-mentioned cyclic olefin resins, the addition copolymer of cyclic olefin and α-olefin or its hydrogenated product has a good balance of properties and cost. Among them, the cyclic olefin resin, which is a copolymer of norbornene and ethylene, is particularly preferable because the ratio of norbornene and ethylene can be easily adjusted and the glass transition point (Tg) can be easily adjusted by the ratio.

The cyclic olefin-based resin may contain other copolymerizable unsaturated monomer components within a range that does not impair the properties thereof. If necessary, a thermoplastic resin, an inorganic or organic filler, various compounding agents and the like may be contained.

The method for producing the cyclic olefin resin is not particularly limited, for example, a monomer composition containing a cyclic olefin and α-olefin is introduced into a reactor, a polymerization catalyst and a polymerization solvent are added thereto, and a predetermined reaction temperature and a reaction A method of reacting under pressure to obtain a polymerization solution and then removing the solvent can be mentioned. The reaction temperature and the reaction pressure can be appropriately set so that the content ratio of the cyclic olefin and the α-olefin in the resin is within a desired range.

As commercially available cyclic olefin resins, TOPAS (manufactured by Polyplastics Co., Ltd.), Apel (manufactured by Mitsui Chemicals, Inc.), Zeonex (manufactured by Nippon Zeon Co., Ltd.), Zeonoa (manufactured by Nippon Zeon Co., Ltd.), Arton (Japan Synthetic Rubber Co., Ltd.) Manufactured). Among them, TOPAS6017S-04 and the like can be exemplified as the cyclic olefin resin having a glass transition point (Tg) of 170° C. or higher.

The styrene-based elastomer is a copolymer of styrene and a conjugated diene such as butadiene or isoprene, and/or a hydrogenated product thereof. The styrene-based elastomer is a block copolymer in which styrene is a hard segment and conjugated diene is a soft segment, and the vulcanization step is unnecessary, and is preferably used. Further, hydrogenated ones have high thermal stability and are more preferable.

Examples of the styrene elastomer include styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-isoprene-butadiene-styrene block copolymer ( SIBS), styrene-ethylene-ethylene-propylene-styrene copolymer (SEEPS) and the like.

The styrene-based elastomer used in the present invention preferably has a small difference in refractive index from the cyclic olefin-based resin in terms of transparency. Specifically, the difference in refractive index is within ±0.02, more preferably ±0.015. It is preferably within.

In the protective film of the present invention, the styrene content in the styrene-based elastomer is preferably 15% by mass or more, and more preferably 30% by mass or more, from the viewpoints of the antiblocking property and the appearance inspection described above. Is more preferably 50% by mass or more.

In the protective film of the present invention, the content of the styrene elastomer in the protective film is preferably 0.1% by mass or more, and 0.5% by mass or more, from the viewpoints of the antiblocking property and the appearance inspection described above. Is more preferable and 1% by mass or more is further preferable. Further, the content of the styrene elastomer is preferably less than 20% by mass, more preferably 15% by mass or less, and further preferably 10% by mass or less. In the protective film of the present invention, in particular, the content of the styrene-based elastomer having a styrene content of 15% by mass or more, further 30% by mass or more, and further 50% by mass or more satisfies these contents. Is preferred.

To the protective film of the present invention, in addition to the cyclic olefin-based resin and the styrene-based elastomer, various compounding agents can be added as needed, as long as the characteristics thereof are not impaired. The various compounding agents are not particularly limited as long as they are used in optical films and the like, and examples thereof include antioxidants, ultraviolet absorbers, light stabilizers, plasticizers, lubricants, antistatic agents, flame retardants, and dyes. And coloring agents such as pigments, near-infrared absorbing agents, compounding agents such as fluorescent whitening agents, and fillers.

The haze of the protective film of the present invention is 10% or less, and may be colorless and transparent or colored and transparent as long as the effect of the present invention in the visual inspection is not impaired.

The protective film of the present invention has a haze of 10% or less. From the viewpoint of the above-mentioned anti-blocking property and appearance inspection, the haze of the protective film of the present invention is more preferably 5% or less, further preferably 3% or less. The haze of the protective film is measured in conformity with JIS K 7136, and the specific measuring method is as described in Examples. In the present invention, the haze of the protective film is adjusted, for example, by the types and contents of the cyclic olefin resin and the styrene elastomer contained in the protective film.

The total light transmittance of the protective film of the present invention is not particularly limited as long as it does not impair the effects of the present invention, and is preferably 85% or more, more preferably 90% from the viewpoint of the above-mentioned antiblocking property and appearance inspection. That is all. The total light transmittance of the protective film is measured in conformity with JIS K 7361-1, and the specific measuring method is as described in Examples. In addition, in the present invention, the total light transmittance of the protective film is adjusted, for example, by the types and contents of the cyclic olefin resin and the styrene elastomer contained in the protective film.

In the protective film of the present invention, the surface roughness Ra (arithmetic mean height) of the surface on the side opposite to the transparent film side is preferably the surface roughness Ra from the viewpoint of the antiblocking property and the appearance inspection described above. It is 7 nm or more, more preferably 10 nm or more, still more preferably 20 nm or more, and preferably 50 nm or less, more preferably 45 nm or less. The surface roughness Ra of the protective film is measured according to JIS R 1683, and the specific measuring method is as described in the examples. In the present invention, the surface roughness Ra of the protective film is adjusted, for example, by the types and contents of the cyclic olefin resin and styrene elastomer contained in the protective film.

In the protective film of the present invention, the surface roughness Rz (maximum height) of the surface on the side opposite to the transparent film side is preferably 47 nm from the viewpoint of the above-mentioned antiblocking property and appearance inspection. As described above, the thickness is more preferably 85 nm or more, still more preferably 180 nm or more, preferably 250 nm or less, more preferably 230 nm or less. The surface roughness Rz of the protective film is measured according to JIS R 1683, and the specific measuring method is as described in the examples. In the present invention, the surface roughness Rz of the protective film is adjusted by, for example, the above-mentioned types and contents of the cyclic olefin resin and the styrene elastomer contained in the protective film.

From the viewpoint of slipperiness, the protective film of the present invention preferably has a coefficient of static friction on the surface opposite to the transparent film side of 10.0 or less, more preferably 5.0 or less, and further preferably 2. It is 0 or less. The static friction coefficient of the protective film is measured in accordance with the regulations of ASTM-D-1894, and the specific measuring method is as described in Examples. In the present invention, the coefficient of static friction of the protective film is adjusted, for example, by the types and contents of the cyclic olefin resin and styrene elastomer contained in the protective film.

The thickness of the protective film of the present invention is not particularly limited as long as it does not impair the effects of the present invention, but from the viewpoint of the antiblocking property and the appearance inspection described above, for example, 20 to 300 μm is preferable, and 30 to 200 μm is more preferable.

The protective film of the present invention can be formed using a resin composition containing a cyclic olefin resin and a styrene elastomer. Specifically, a polymerization solution of a cyclic olefin resin and a styrene elastomer are mixed and the solvent is removed under high temperature and reduced pressure conditions to obtain a mixture in a molten state. The mixture is extruded to produce pellets. Then, using this pellet, a protective film having a predetermined thickness, preferably 20 to 300 μm, can be formed by a T-die method or a calendar method. However, the production method is not limited to this, and for example, pellets may be produced after melt-kneading a styrene elastomer with a cyclic olefin resin and adding the styrene elastomer.

The protective film of the present invention is preferably formed by biaxially stretching the resin composition. In the biaxial stretching, for example, it is formed by stretching an unstretched film of the resin composition in MD (machine direction) and TD (direction orthogonal to MD). By biaxially stretching, the toughness is higher than that of an unstretched protective film, and cracking of the film alone can be suppressed.

2. Protective Film with Adhesive Layer The protective film with an adhesive layer of the present invention has a surface on the transparent film side (that is, a side laminated with a transparent film) of the protective film 1 of the present invention described above, as shown in the schematic view of FIG. In addition, it is a laminated body in which at least the adhesive layer 2 is laminated. The details of the protective film are as described above.

The adhesive layer is composed of a transparent adhesive. The pressure-sensitive adhesive is a layer for adhering the protective film so that the protective film can be peeled from the transparent film. As the adhesive, known adhesives can be used, for example, acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyvinyl ethers, vinyl acetate/vinyl chloride copolymers, modified polyolefins, epoxy series, fluorine series, A rubber-based polymer such as natural rubber or synthetic rubber can be appropriately selected and used. In particular, an acrylic pressure-sensitive adhesive is preferably used because it is excellent in optical transparency, exhibits appropriate wettability, cohesiveness, adhesiveness and other adhesive properties, and is also excellent in weather resistance and heat resistance.

The method for forming the pressure-sensitive adhesive layer is not particularly limited, a method of coating the pressure-sensitive adhesive composition on a release liner, drying and then transferring to a protective film (transfer method), directly coating the pressure-sensitive adhesive composition on the protective film, and drying. Examples of the method (direct copying method), coextrusion method, and the like. As the pressure-sensitive adhesive, a tackifier, a plasticizer, a filler, an antioxidant, an ultraviolet absorber, a silane coupling agent, or the like can be appropriately used as necessary.

The thickness of the adhesive layer is not particularly limited, but is preferably 5 to 100 μm, more preferably 10 to 50 μm, and further preferably 15 to 35 μm.

3. Transparent Film with Protective Film As shown in the schematic diagram of FIG. 3, the transparent film with a protective film has a surface on the transparent film side (that is, a side laminated with the transparent film) of the above-mentioned protective film 1 of the present invention. In addition, at least the adhesive layer 2 and the transparent film 3 containing a cyclic olefin resin are laminated in this order. The details of the protective film and the adhesive layer are as described above.

The transparent film containing a cyclic olefin resin is not particularly limited, and for example, a known film such as an optical film used for an input device such as a liquid crystal display device, an EL display device and a touch panel can be used. That is, the protective film of the present invention can be applied to a transparent film containing a known cyclic olefin resin together with a known adhesive layer to protect the transparent film.

The cyclic olefin-based resin contained in the transparent film is not particularly limited, and examples thereof include the cyclic olefin-based resin described above. In addition to the cyclic olefin resin, the transparent film may further contain the above-mentioned styrene elastomer.

The thickness of the transparent film is not particularly limited, but is preferably 10 to 100 μm, more preferably 13 to 50 μm, and further preferably 23 to 40 μm.

In the protective film-attached transparent film of the present invention, the protective film is laminated together with an adhesive layer to protect the transparent film in the production, distribution process, etc. of the transparent film containing a cyclic olefin-based resin. When used as a film or the like, it is peeled off from the transparent film together with the adhesive layer.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the examples.

Examples 1 to 4 and Comparative Examples 1 and 2
<Production of protective film>
Using a φ32 mm single-screw extruder, cycloolefin copolymer (manufactured by Polyplastics Co., Ltd.) as cyclic olefin resin, Septon series (manufactured by Kuraray Co., Ltd.) as styrene elastomer, content of styrene elastomer and styrene elastomer Extruding from a coat hanger die (300 mm width, 1.3 mm gap) while extruding (extrusion temperature 310°C, discharge amount 20 kg/) while kneading (screw rotation speed 150 rpm) so that the styrene contents become the values shown in Table 1, respectively. hr) and wound on a roll to obtain each protective film having a thickness of 80 μm.

<Production of transparent film with protective film>
On one surface (surface opposite to the surface on which the surface roughness Ra, Rz, and static friction coefficient were measured) of each of the obtained protective films, the following acrylic adhesive (acrylic adhesive: acrylic adhesive coponyl manufactured by Nippon Synthetic Chemical Industry) To 4 parts by weight of N-4900, 1 part by weight of an epoxy-based cross-linking agent (“Tetrad C” manufactured by Mitsubishi Gas Chemical Co., Ltd. was added to obtain a pressure-sensitive adhesive composition), and the thickness after drying was applied to be 25 μm. It was applied by a machine and dried to obtain a surface protective film with an adhesive layer.

Next, the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive layer-attached surface protective film and a cycloolefin-based transparent film (ZF-14 manufactured by Nippon Zeon Co., Ltd., thickness 50 μm) are laminated using a nip roll to protect them. A transparent film with a film was obtained.

<Total light transmittance>
Each of the protective films obtained above was used as a test piece, and the total light transmittance of the protective film was measured in accordance with JIS K 7361-1. A haze meter NDH5000 (manufactured by Nippon Denshoku Industries Co., Ltd.) was used for measuring the total light transmittance. The results are shown in Table 1.

<Haze>
Using each of the protective films obtained above as a test piece, the haze of the protective film was measured according to JIS K 7136. A haze meter NDH5000 (manufactured by Nippon Denshoku Industries Co., Ltd.) was used to measure the haze. The results are shown in Table 1.

<Surface roughness Ra, Rz>
Using each of the protective films obtained above as a test piece, the surface roughness Ra (arithmetic mean height) and the surface roughness Rz (maximum height) were measured in accordance with the regulations of JIS R1683. Specifically, the surface roughness Ra and Rz were measured using a scanning probe microscope SPM-9600 (Shimadzu Corporation), respectively, within a region of 50 μm×50 μm with respect to the surface to be measured of the protective film. The arithmetic average height and maximum height were calculated. The results are shown in Table 1.

<Static friction coefficient>
Each of the protective films obtained above was used as a test piece, and the static friction coefficient was measured according to the regulations of ASTM-D-1894. Specifically, a surface property measuring device, Tribogear HEIDON14FW (manufactured by Shinto Kagaku Co., Ltd.) was used to measure the static friction coefficient. The test piece was fixed on a moving table, the test force (load) when the facing surfaces of the protective film were slid on each other was measured, and the friction coefficient was calculated from the following formula. The measurement conditions were flat plate indenter 63.5×63.5 mm, load 200 gf, surface pressure 0.49 kPa, speed 5.0 mm/sec, and moving distance 50 mm. The results are shown in Table 1.
Coefficient of static friction: μs = peak test force/weight Dynamic coefficient of friction: μk = average test force/weight

<Evaluation of anti-blocking property>
The transparent film with each protective film obtained above was prepared, and the protective film side and the transparent film side were overlapped and placed on a glass plate to prepare a test sample (the transparent film side was defined as the glass plate side). Next, the test sample was pressed from above the protective film with a finger, and the appearance of the watermark at the interface between the protective film and the transparent film immediately after the finger was removed was visually confirmed. The test samples were evaluated so that no air gap (clearance) was formed at the superposed interfaces. The antiblocking property was judged according to the following criteria. The results are shown in Table 1.
(Criteria)
A: Water mark of visually recognizable size did not appear B: Water mark of visually identifiable size appeared, but disappeared within 10 seconds C: Visually identifiable Watermark of size appeared

<Appearance inspection>
Using each of the transparent films with a protective film obtained as described above, the appearance inspection of the transparent film was performed by the following method, and it was evaluated that the appearance inspection of the transparent film can be performed with the protective film laminated. The criteria for judgment are as follows. The results are shown in Table 1.
(Inspection method)
The appearance of the transparent film with the protective film was examined under the transmitted light of a three-wavelength fluorescent lamp.
(Criteria)
A: 0.1 mm ² of foreign matter, scratches, stains and other appearance defects of the transparent film can be inspected by the above inspection method.
C: 0.1 mm ² of foreign matter, scratches, stains and other appearance defects of the transparent film cannot be inspected by the above inspection method.

1 Protective film 2 Adhesive layer 3 Transparent film 20 Protective film with adhesive layer 30 Transparent film with protective film

Claims (5)

Laminated on a transparent film containing a cyclic olefin-based resin, used to protect the transparent film, a peelable protective film,
The protective film contains a cyclic olefin resin and a styrene elastomer,
The surface roughness Ra of the surface of the protective film opposite to the transparent film side is 7 nm or more,
The surface roughness Rz of the surface of the protective film opposite to the transparent film side is 47 nm or more,
The protective film has a haze of 10% or less. The protective film according to claim 1, wherein the content of the styrene-based elastomer contained in the protective film is less than 20% by mass. The protective film according to claim 1, wherein the styrene content of the styrene elastomer is 15% by mass or more. A protective film with an adhesive layer, in which at least an adhesive layer is laminated on the surface of the protective film according to any one of claims 1 to 3 on the transparent film side. With a protective film, at least an adhesive layer and a transparent film containing a cyclic olefin resin are laminated in this order on the surface of the protective film according to any one of claims 1 to 3 on the transparent film side. Transparent film.