JP2001335649A - Polymer film and surface protective film using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface protective film of which removal is not required in inspection and good in inspection properties when this film is used by sticking to a constitutent member and the like of a liquid crystal displaying unit, and a biaxial drawing polymer film to be a substrate of the above surface protective film. SOLUTION: The polymer film composed of an organic polymer, is characterized in that the maximum strain of oriented principal axis of the above polymer film measured by a microwave transmission molecular orientation meter, is 7 degree or below, and a haze value is 10 to 25%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer film which is suitably used as a protective film or a separator for a surface protection of a synthetic resin plate or the like, in particular, a constituent member of a liquid crystal display such as a polarizing plate or a retardation plate, and a polymer film. The present invention relates to a used surface protective film.

[0002]

2. Description of the Related Art A liquid crystal display device is generally constituted by laminating a polarizing plate, a liquid crystal cell and a polarizing plate from the backlight side. Further, various compensating plates such as a phase difference plate are inserted for the purpose of improving the display mode and the viewing angle. The lamination of the polarizing plate and the retardation plate is usually performed by attaching a polarizing plate with an adhesive layer or a retardation plate with an adhesive layer to an object.

The above-mentioned polarizing plate has a structure in which a polarizing film is sandwiched by triacetyl cellulose, and usually has an adhesive layer for bonding on one side thereof. Furthermore, since triacetylcellulose of the polarizing plate has poor scratch resistance and moisture resistance, surface protective films are provided on both sides for the purpose of preventing damage, moisture, or dust from adhering during handling and during the manufacturing process of the liquid crystal display device. Can be On the opposite side of the polarizing plate from the adhesive layer side, a surface protective film (protective film) with an adhesive layer laminated is used, and on the adhesive layer side, a surface protective film (separator) with a release layer laminated is used. You.

Further, various compensating plates such as a retardation plate are also usually provided with an adhesive layer for lamination on one side thereof, so as to prevent damage and dust from adhering during handling and during a manufacturing process of the liquid crystal display device. Similarly to the above-mentioned polarizing plate, surface protection films (protection film and separator) are used on both surfaces of various compensating plates.

[0005] When a polarizing plate, a retardation plate or the like is bonded to a liquid crystal cell, the surface protective film is peeled off and used.

Conventionally, as the surface protective film on which the above-mentioned pressure-sensitive adhesive layer is laminated, a heat-compression-bonding type such as a polyethylene film or an ethylene-vinyl acetate copolymer film, and a polyester film provided with a pressure-sensitive adhesive layer are used. A pressure bonding type is used.

As a conventional surface protective film having a release layer laminated thereon, a film obtained by applying a release agent such as silicone to at least one surface of a biaxially stretched film such as polyester or polypropylene is used. .

[0008]

Generally, the components of the manufactured liquid crystal display device are inspected in a timely manner in order to evaluate the display capability, hue, contrast and the like. However, surface protection films that have been widely used in the past, because their base materials have anisotropy, would hinder inspection involving optical evaluation of components to which such a surface protection film was attached. Therefore, prior to the inspection, the surface protective film is once peeled off and removed, and after the inspection is completed, a new surface protective film is attached again. The reason for reattaching with a new surface protective film is that even if the surface protective film can be reapplied, the reattachment will impair the beauty.

In the above-mentioned inspection, the peeling and re-sticking of the surface protective film requires two steps, which is a great hindrance in this field where cost reduction is pursued to the utmost.

As an attempt to solve the above-mentioned conventional problems and to inspect a polarizing plate or a retardation plate provided with an adhesive layer while covering a surface protective film, for example, Japanese Patent Application Laid-Open No.
Japanese Patent Application Laid-Open No. Hei 6-14843 discloses a surface protection film in which an adhesive resin layer is provided on one surface of a light isotropic substrate such as polycarbonate and polyarylate.
No. 1 discloses a surface protective film having a release layer provided on at least one surface of a substrate made of a non-oriented film such as polyester or polypropylene.
No. 026 proposes a method of laminating the biaxially oriented polyester film such that the direction of the principal axis of orientation of the biaxially oriented polyester film is substantially the same as the direction of the orientation axis of the polarizing plate or retardation plate, or the orientation is 90 °.

Although such a non-oriented film has optical isotropy, it has a great advantage that peeling is not required at the time of inspection. However, it is difficult to suppress the orientation by the ordinary melt extrusion method. It is necessary to use a manufacturing method such as the drawing method, and the base film itself becomes expensive,
At present, it is hardly used for the surface protective film that is finally peeled off. Further, in the method using a biaxially oriented polyester film, it is difficult to strictly control the direction of the main orientation axis, and thus there is a problem that the yield is deteriorated.

As a method for solving these problems, the present inventors have found that in Japanese Patent Application No. 11-118865, a polymer film having a minimum contrast value of 70 or more can solve the above problems. In particular, it has been found that the effect is remarkable when a uniaxially stretched polymer film is used. This method does not require peeling at the time of inspection, and provides a surface protection film having good inspection properties and low cost. However, because the polymer film has too high a contrast, if the polymer film itself has scratches or foreign substances, defects caused by the film are noticeable at the time of inspection of the polarizing plate, and whether the inspection of the polarizing plate is performed on the surface protective film. It is not clear whether or not the inspection is being performed, and a new problem arises that the efficiency of inspection of a polarizing plate, a retardation plate, and the like is reduced.

[0013] Therefore, it is necessary to reduce the scratches on the surface protective film to a high level (to reduce not only large scratches but also small scratches as much as possible). In some cases, it must be reduced.

That is, an object of the present invention is to solve the above-mentioned conventional problems and, when used by attaching to a component member or the like of a liquid crystal display device, does not require peeling at the time of inspection, and provides a surface protection with good inspectability. An object of the present invention is to provide a film and a biaxially stretched polymer film as a base material thereof.

[0015]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, the maximum distortion of the main alignment axis measured by a microwave transmission type molecular orientation meter is 7 degrees or less, and By using a polymer film having a haze value in the range of 10 to 25% as the base film of the surface protective film, defects can be easily seen at the time of inspection without peeling off the components of the liquid crystal display device at the time of inspection. The present inventors have found that the cost can be further reduced, leading to the present invention.

That is, the present invention is as follows. 1. A polymer film made of an organic polymer, wherein the maximum distortion of the principal axis of the polymer film measured by a microwave transmission type molecular orientation meter is 7 degrees or less, and the haze value is 10 to 25%. A polymer film characterized by the following.

2. 2. The polymer film according to the first aspect of the invention, wherein a minimum value of a maximum / minimum ratio (MOR value) of microwave transmission intensity measured by a microwave transmission type molecular orientation meter is larger than 1.8.

3. The heat shrinkage at 120 ° C. is 5.0%
The polymer film according to the first or second aspect of the present invention, wherein:

4. The above-mentioned 1, 2, or 3, wherein the polymer film is a uniaxially stretched polymer film.
The polymer film according to the invention.

[5] 5. The polymer film according to the above 1, 2, 3, or 4, wherein the polymer film is a polyester film.

6. 5. The method according to item 5, wherein the polyester film is a film composed of polyethylene terephthalate or a polyester mainly composed of polyethylene terephthalate.
The polymer film according to the invention.

7. 7. A surface protective film, wherein a pressure-sensitive adhesive layer is laminated on one surface of the polymer film according to any one of the above-mentioned items 1, 2, 3, 4, 5, and 6.

8. The surface protection film according to the seventh aspect, wherein an antistatic layer is laminated on a surface of the polymer film opposite to the side of the pressure-sensitive adhesive layer.

9. The surface protection film according to the seventh aspect, wherein an antistatic layer is laminated between the pressure-sensitive adhesive layer and the polymer film.

10. Said 1, 2, 3, 4, 5, or 6
A surface protective film, wherein a release layer is laminated on one surface of the polymer film according to any one of the above aspects.

11. The surface protective film according to the tenth aspect, wherein an antistatic layer is laminated on a surface of the polymer film opposite to the release layer side.

12. The surface protective film according to the tenth aspect, wherein an antistatic layer is laminated between the release layer and the polymer film.

13. The release layer according to the tenth aspect,
A surface protective film comprising a silicone resin and / or a fluorine resin as a main component.

14. A surface protection film, wherein the silicone resin according to the thirteenth aspect is mainly composed of a thermosetting silicone resin or a radiation curing silicone resin.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The polymer film of the present invention is a polymer film in which the maximum distortion of the main alignment axis measured by a microwave transmission type molecular orientation meter is 7 degrees or less and the haze value is in the range of 10 to 25%. It can be manufactured by a method. However, it is not limited to this method.

The polymer film of the present invention is a film obtained by subjecting an organic polymer to melt extrusion or solution extrusion and, if necessary, stretching, cooling and heat setting in the longitudinal or width direction. As the molecule, polyethylene, polyolefin such as polypropylene, polyethylene terephthalate, polyethylene-2,6-naphthalate, polyester such as polypropylene terephthalate, nylon 6, nylon 4, nylon 6,6, polyamide such as nylon 12, polyimide, polyamide imide, Polyether sulfone, polysulfone, polyether ether ketone, polycarbonate, polyarylate, polyacryl, cellulose propionate, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyetherimide, polyfe Rensurufido, polyphenylene oxide, polystyrene, syndiotactic polystyrene tick, such as norbornene-based polymer and the like. In addition, these organic polymers may be copolymerized or blended with a small amount of another organic polymer. Of these, polyester films such as polyethylene terephthalate, polyethylene-2,6-naphthalate, and polypropylene terephthalate are preferably used.

Among them, polyethylene terephthalate is most preferably used because of its small amount of impurities and its overall performance such as transparency, mechanical properties, surface smoothness, solvent resistance, scratch resistance, moisture impermeability and cost.

The polymer film of the present invention can be obtained by forming a film by a conventional method. Above all, a melt or solution of a homopolymer or copolymer is formed into a film by extrusion, calendering, casting, or the like, and then uniaxially in the vertical or horizontal direction by a roll method, tenter method, tubular method, or the like. The stretching method is preferred. However, as long as the range of the film properties of the present invention is satisfied, biaxial stretching may be performed.

In the polymer film of the present invention, it is necessary that the maximum distortion of the principal axis of the orientation measured by a microwave transmission type molecular orientation meter is at least 7 degrees or less, more preferably at least 5 degrees or less. In the case of a polymer film in which the maximum distortion of the orientation main axis exceeds 7 degrees, it will hinder the detection of foreign substances and scratches in the sample during the inspection.

In the present invention, the maximum strain of the main alignment axis measured by a microwave transmission type molecular orientation meter is measured by the following method. First, when the film shape is a roll shape, a rectangle having a length of 500 mm and a full width in the width direction is cut out. Then, as shown in FIG. 8, a square of 100 mm square is cut out in three or more places including two vertexes of the rectangle and the center thereof in the width direction (tenter direction) including the same end side. In FIG. 8, 21 is the longitudinal direction, 22
Is a width direction, 23 is an edge, 24 is a vertex, and 25 is a center of the vertex. Next, each orientation main axis is measured by a microwave transmission type molecular orientation meter, and the difference from 0 degree when each molecular orientation angle is smaller than 45 degrees, and 90 degrees when each molecular orientation angle is larger than 45 degrees.
The maximum value was determined from the largest absolute value of the difference from the degree, and the maximum value was defined as the maximum distortion of the main alignment axis. The microwave transmission type molecular orientation meter includes a molecular orientation meter manufactured by Kanzaki Paper Co., Ltd. (MOA-
2001A) was used.

In the present invention, as described below, the maximum strain of the principal axis of the polymer film measured by a microwave transmission type molecular orientation meter within the above-mentioned range is determined by the temperature in longitudinal stretching, the stretching ratio, and the transverse stretching. Before performing the heat-setting treatment after the transverse stretching at the temperature and stretching ratio in the above, a method of performing a relaxation treatment of 1 to 10% at 90 to 200 ° C in the longitudinal direction, a method of performing a heat-setting treatment at 130 to 250 ° C, A method of performing a relaxation treatment at 1 to 10% in the width direction after the heat setting treatment, or the like is suitable.

Further, in the polymer film of the present invention, the haze value needs to be in the range of 10 to 25%, preferably in the range of 14 to 21%. When the haze value is less than 10%, the scattered light when light passes through the polymer film is small, the peeling is not required at the time of inspection, and the inspection property is good, but when the scratch is present on the polymer film surface, At the time of inspection, scratches on the surface of the polymer film are conspicuous, making it impossible to accurately test for defects of the specimen itself. The visible light transmittance of the polymer film is preferably 75% or more.

In the present invention, the method for adjusting the haze value of the polymer film to the above range includes a method for adjusting the film thickness of the polymer film, a method for adjusting the content of inert particles contained in the polymer film, A method of lowering the stretching ratio is suitable. Among them, a method of adjusting the content of inert particles is preferably used.

In the method of lowering the draw ratio, if the draw ratio is too low, the haze value of the obtained film increases, and the transparency of the film can be reduced. However, if the draw ratio is too low, the draw tension will also be small,
In the obtained film, the anisotropy of the biaxial refractive index is reduced, and as a result, the MOR value may be reduced, which is not preferable.

As the inert particles contained in the polymer film, inorganic particles such as titanium oxide, silica, calcium carbonate, kaolin, alumina, clay, calcium phosphate, barium phosphate, barium sulfate, calcium fluoride, lithium fluoride, zeolite, etc. Particles, heat-resistant resin particles such as cross-linked polystyrene, cross-linked polymethyl methacrylate, cross-linked polyacrylic acid, polyimide, and silicone resin, and so-called precipitated particles formed during polymerization of a polymer are exemplified. These may be synthetic or natural products. The shape of the particles is not limited, but is preferably spherical, rice, plate, amorphous or the like. Further, the average particle size is not particularly limited, but particles having a size of preferably 0.01 to 1.5 μm, more preferably 0.01 to 1.0 μm are used. In addition, the polymer film contains at least one or more types of inert particles, and when it contains two or more types, the particle types may be different, and a combination of the same particle types but different average particle sizes is used. You may.

It is necessary to set the content of the inert particles in the polymer film so that the haze value of the polymer film is in the above-mentioned range. It is set appropriately in consideration of the thickness and the like. The content of the inert particles is 0.0% with respect to the film.
5 to 1.5% by weight, preferably 0.06 to 1.
It is 5% by weight, particularly preferably 0.1 to 1.0% by weight. When the content of the inert particles is less than 0.05% by weight, the slipperiness of the polymer film is reduced, and the polymer film is easily damaged, which is not preferable. Conversely, when the content exceeds 1.5% by weight, coarse projections are generated due to aggregation of fine particles in the film, and the film surface is easily damaged. As a result, the testability deteriorates, which is not preferable.

The polymer film of the present invention preferably has a minimum MOR value of more than 1.8 as measured by a microwave transmission type molecular orientation meter. More preferably, it is 2.0 or more, still more preferably 2.2 or more. If the minimum value of the MOR value is not more than 1.8, the unevenness of the orientation axis tends to be large at the central portion and the end portion of the raw material during production of the polymer film, which is not preferable.

The polymer film of the present invention has the following properties.
The heat shrinkage at 20 ° C. is preferably 5% or less, particularly preferably 1% or less. When the heat shrinkage ratio is more than 5%, it is not preferable because flatness is likely to be disturbed when passing through a process involving heating such as formation of the pressure-sensitive adhesive layer and the antistatic layer.

In the present invention, the heat shrinkage at 120 ° C. is measured by the following method. First, a circle having a diameter of 50 mm is drawn around the intersection of diagonal lines of a film cut into a square having a side of 100 mm. Then, this was placed in a hot-air dryer heated to 120 ° C. with no load for 30 minutes.
Leave for a minute. This is taken out, the dimensional change is read by a digitizer, and it is obtained from the length (B; mm) of the maximum position of contraction through the intersection of the diagonal lines by the following equation. Heat shrinkage at 120 ° C. = (50−B) / 50 × 10
0 (%)

In the present invention, 120 of the polymer film is used.
As a method of setting the heat shrinkage at the above-mentioned range in the above-mentioned range, a method in which the film is subjected to a relaxation treatment of 1 to 5% at 120 to 180 ° C. in the longitudinal direction after the transverse stretching and before the heat-setting treatment, A method of setting the temperature to 130 to 250 ° C., a method of performing a 2 to 5% relaxation treatment in the width direction after the heat setting treatment, and the like are preferable.

The method for producing a polymer film in the present invention is not particularly limited as long as a film having the above-mentioned film properties defined in the present invention can be obtained.
For example, in the case of a polyester film, the polyester is melted, and the non-oriented polyester extruded and formed into a sheet is stretched at a temperature equal to or higher than the glass transition temperature, in a longitudinal direction.
A method of performing transverse stretching and then performing a heat setting treatment may be used.

The longitudinal stretching temperature is preferably from 90 to 135 ° C., particularly preferably from 100 to 130 ° C. The longitudinal stretching ratio is preferably from 1.1 to 4.0 times, particularly preferably from 1.5 to 3.5 times. Lateral stretching temperature is 80-130 ° C
And particularly preferably 90 to 120 ° C. Further, the transverse stretching ratio is preferably 2.5 to 6.0 times, particularly preferably 3.0 to 5.5 times.

In the present invention, relaxing the film in the longitudinal direction before performing the heat setting treatment after the transverse stretching is effective for suppressing the maximum distortion of the main orientation axis. The temperature during the relaxation treatment in the longitudinal direction is preferably from 90 to 200 ° C, particularly preferably from 120 to 180 ° C. Although the amount of relaxation varies depending on the transverse stretching conditions, it is about 1 to 10%, and the heat shrinkage of the film after the relaxation treatment at 120 ° C. is 5%.
It is preferable to set the relaxation amount and the relaxation temperature so as to be as follows.

In the subsequent heat-setting treatment, the heat-setting temperature is preferably from 130 to 250 ° C., particularly preferably 1 to 250 ° C.
80-245 ° C. In the heat setting treatment, first, the heat setting treatment is performed without changing the length in the width direction, and the relaxation in the width direction is reduced to 1 to 10%, particularly 2 to 5%, thereby suppressing the maximum distortion of the main alignment axis. can do.

In the present invention, the thickness of the polymer film is
Although not particularly limited, it is appropriate to set the thickness to 300 μm or less in consideration of use and workability. If the thickness exceeds 300 μm, the advantage of a thin polymer film is lost.

The polymer film may have not only a single-layer structure but also a laminated structure. In particular, when the haze value is increased by the inert particles, considering the adverse effects such as a decrease in the surface properties of the polymer film due to the inert particles, the inert particles of the central layer having a larger thickness than the surface layer are taken into consideration. A laminated film composed of at least three layers and having a large content is preferable.

The polymer film of the present invention may contain known additives as necessary. For example, an antiblocking agent, a heat stabilizer, an antioxidant, an antistatic agent,
A light stabilizer, an impact resistance improver and the like may be contained.

The polymer film of the present invention is used for the purpose of improving adhesion, water resistance, chemical resistance, etc. with layers formed on the film such as a pressure-sensitive adhesive layer, a release layer and an antistatic layer. The film surface may be subjected to a surface treatment by a known method, that is, a corona discharge treatment (in air, in nitrogen, in carbon dioxide gas, or the like) or an easy adhesion treatment. Various known methods can be used for the easy adhesion treatment, and a method of applying various known easy adhesives to the film during the film production process or after uniaxially or biaxially stretched film is suitably adopted.

The surface protective film of the present invention is a film obtained by forming an adhesive layer or a release layer on one side of the polymer film of the present invention.

As the pressure-sensitive adhesive layer, a layer having an adhesive property to an optical member, for example, a layer made of a heat-sensitive adhesive resin such as a polyester-based, polyolefin-based, or polyamide-based; A layer composed of an ether-based or rubber-based pressure-sensitive adhesive resin; or a curing agent mixed with a resin having a functional group such as a saturated polyester resin, a polyurethane-based resin, a polybutadiene polyol, a polyolefin polyol, or a functional group-containing acrylic copolymer. Film formed by partial cross-linking or incomplete cross-linking; soft polyvinyl chloride film in which a plasticizer is blended with, for example, 20% by weight or more of polyvinyl chloride; saturated polyester resin film; acrylic copolymer film; butyl rubber, urethane Rubber, butadiene rubber (polybutadiene rubber, styrene- Films obtained by forming synthetic rubbers such as tadiene rubber, styrene-butadiene-styrene block copolymer) and styrene-isoprene-styrene rubber; polyolefin resins such as low molecular weight polyethylene, atactic polypropylene, and chlorinated polypropylene A film obtained by forming an ethylene copolymer such as an ethylene-vinyl acetate copolymer, an ethylene-acrylic acid copolymer, or an ethylene-acrylate copolymer. And the like.

The rework (rewar) is applied to the surface protection film.
k) When the property is required, a material having peelability (easy to peel) is selected for the pressure-sensitive adhesive layer, and when the surface protective film requires permanent adhesion, a strong adhesive force or adhesive force is obtained. Select a material. The thickness of the adhesive layer is usually 1 to
It is set to about 50 μm.

When the surface protective film of the present invention is used by adhering it to the pressure-sensitive adhesive layer side of a polarizing plate, a release layer is provided on one side of the above-mentioned polymer film (the pressure-sensitive adhesive layer side of the polarizing plate). It is necessary to form The release layer preferably contains at least one selected from a silicone resin and a fluororesin as a main component.

As the silicone resin, those generally known as release agents can be used, and are described in “Silicone Material Handbook” (edited by Dow Corning Toray, 1993.
8) can be used by selecting from the descriptions.
As a general silicone resin, a thermosetting type or an ionizing radiation curing type is used. As the thermosetting type, any reaction type such as a condensation reaction type and an addition reaction type, and as the ionizing radiation curing type, an ultraviolet or electron beam curing type can be used.

Examples of the condensation reaction type silicone resin include, for example, a polydimethylsiloxane having a terminal -OH group and a polydimethylsiloxane (hydrogensilane) having a terminal -H group in an organic tin catalyst (for example, an organic tin acylate catalyst). ) To form a three-dimensional crosslinked structure.

Examples of the addition reaction type silicone resin include those which form a three-dimensional crosslinked structure by reacting polydimethylsiloxane having a vinyl group introduced into a terminal with hydrogen silane using a platinum catalyst.

As the ultraviolet-curable silicone resin,
For example, the most basic type uses the same radical reaction as ordinary silicone rubber crosslinking, the one that introduces an acrylic group and photocures it, and the one that decomposes onium salts with ultraviolet rays to generate a strong acid, thereby producing an epoxy ring. And those which are crosslinked by addition reaction of thiol to vinyl siloxane. Electron beams have higher energy than ultraviolet rays, and a radical crosslinking reaction occurs without using an initiator as in the case of ultraviolet curing.

The above-mentioned curable silicone resin preferably has a polymerization degree of about 500,000 to 200,000, particularly about 1,000 to 100,000. Specific examples thereof include KS-718 manufactured by Shin-Etsu Chemical Co., Ltd. , -774, -775, -77
8, -779H, -830, -835, -837, -8
38, -839, -841, -843, -847, -8
47H, X-62-2418, -2422, -212
5, -2492, -2494, -5048, -470,
-2366, -630, X-92-140, -128,
KS-723A-B, -705F, -708A, -88
3, -709, -719, TP manufactured by Toshiba Silicon Corporation
R-6701, -6702, -6703, -3704,
-6705, -6721, -6722, -6700, X
SR-7029, YSR-3022, YR-3286,
DK-Q3-202, -20 manufactured by Dow Corning Co., Ltd.
3, -204, -205, -210, -240, -30
03, -3057, SFXF-2560, SD-7226, -7 manufactured by Dow Corning Toray Silicone Co., Ltd.
229, -7320, BY-24-900, -171,
-312, -374, SRX-375, SYL-OFF
23, SRX-244, SEX-290, IC
SILCOLASE 425 manufactured by I Japan Co., Ltd.
And the like.

Further, silicone resins described in JP-A-47-34447 and JP-B-52-40918 can also be used. Further, one of these curable silicone resins may be used alone, or two or more thereof may be used in combination.

As the fluororesin, a known release resin can be used. As such a fluororesin,
For example, a polymer (including an oligomer) comprising a fluorine-containing vinyl polymerizable monomer or a copolymer thereof, or a vinyl containing no fluorine-containing vinyl polymerizable monomer and an alkyl group or functional group substituted with a fluorine atom Copolymers with at least one polymerizable monomer, or a mixture thereof and having 5 to 80 mol% of fluorine atoms are exemplified.

Examples of the polymer comprising the above-mentioned fluorine-containing vinyl polymerizable monomer include poly [2-
(Perfluorononenyloxy) ethyl methacrylate], poly [2- (perfluorononenyloxy) ethyl acrylate], poly [2- (perfluorononenyloxybenzoyloxy) ethyl methacrylate], poly [2- (perfluoro Nonenyloxybenzoyloxy) ethyl acrylate], poly [2,2,2-trifluoroethyl methacrylate], poly [2,2,2-trifluoroethyl acrylate], poly [2,2,3
3,3-pentafluoropropyl methacrylate], poly [2,2,3,3,3-pentafluoropropyl acrylate], poly [1-methyl-2,2,3,3,4
4-hexafluorobutyl methacrylate], poly [1
-Methyl-2,2,3,3,4,4-hexafluorobutyl acrylate], poly [perfluoroheptylethyl methacrylate], poly [perfluoroheptylethyl acrylate], poly [perfluoroheptylvinyl ether], poly [α , Β, β-trifluorostyrene], polyvinylidene fluoride, polyhexafluoropropylene, polytetrafluoroethylene, and the like.

The vinyl polymerizable monomer which is copolymerizable with the above-mentioned fluorine-containing vinyl polymerizable monomer and which does not contain an alkyl group substituted with a fluorine atom, a functional group, and the like includes a hydrocarbon-based vinyl polymerizable monomer. , Hydrocarbon-based non-conjugated divinyl polymerizable monomers, and functional group-containing vinyl polymerizable monomers. Specifically, it is selected from the compounds exemplified below, but is not particularly limited.

Examples of the hydrocarbon-based vinyl polymerizable monomer include:
For example, methyl acrylate, propyl acrylate, butyl acrylate, isoamyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, octadecyl acrylate, lauryl acrylate, cesyl acrylate, N, N-diethylaminoethyl acrylate, methacrylic acid Methyl, propyl methacrylate, butyl methacrylate, isoamyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, octadecyl methacrylate, lauryl methacrylate, cesyl methacrylate, N, N-diethylaminoethyl methacrylate, vinyl acetate,
Vinyl propionate, vinyl caprate, vinyl laurate, vinyl stearate, styrene, α-methylstyrene, p-methylstyrene, vinyl chloride, vinyl bromide,
Vinylidene chloride, allyl heptanoate, allyl acetate, allyl caprate, allyl caproate, vinyl methyl ketone, vinyl ethyl ketone, 1,3-butadiene, 2-chloro-1,3-butadiene, 2,3-dichloro-1, 3
-Butadiene, isoprene and the like.

Examples of the hydrocarbon non-conjugated divinyl polymerizable monomer include ethylene glycol diacrylate and
Ethylene glycol dimethacrylate, propylene glycol diacrylate, propylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, divinylbenzene, vinyl acrylate,
And dibromoneopentyl glycol dimethacrylate.

The functional group-containing vinyl polymerizable monomers include:
For example, acrylic acid, methacrylic acid, acrylamide,
Methacrylamide, N-methylolacrylamide, N
-Butoxymethyl acrylamide, diacetone acrylamide, methylol diacetone acrylamide, 2
-Hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl acrylate,
3-chloro-2-hydroxypropyl methacrylate and the like.

When a release layer is provided on one side of the polymer film of the present invention, the thickness of the release layer is not particularly limited.
The range of from 0.5 to 5 μm is preferred. If the thickness of the coating film is smaller than this range, the releasing performance is reduced, and satisfactory performance cannot be obtained. Conversely, if the thickness of the coating film is larger than this range, curing takes a long time, which is not preferable in terms of production.

In the release layer, known additives such as an antifoaming agent, a coating improver, a thickener, an antistatic agent, an antioxidant, and an ultraviolet absorber may be used as long as the object of the present invention is not impaired. ,
A curing agent, a dye and the like may be contained.

The method for forming the pressure-sensitive adhesive layer or the release layer of the present invention on the surface of the polymer film as the base film is not particularly limited, but a coating method is preferably used. For example, coating methods include air doctor coating, knife coating, rod coating, forward rotation roll coating, reverse roll coating, gravure coating, kiss coating, bead coating, slit orifice coating, and cast coating. And the like.

Further, the drying and / or curing (thermal curing, ionizing radiation curing, etc.) of the coating film of the pressure-sensitive adhesive layer or the release layer is performed by:
Each can be performed individually or simultaneously. If they are performed simultaneously, it is preferable to perform at a temperature of 80 ° C. or higher. The drying and curing conditions are preferably at 80 ° C. or higher for 10 seconds or longer. Drying temperature is less than 80 ° C or curing time is 1
If the time is less than 0 second, the curing of the coating film is incomplete and the coating film is liable to fall off, which is not preferable.

Further, the surface protective film provided with the pressure-sensitive adhesive layer and the surface protective film provided with the release layer of the present invention include:
It is preferable to provide an antistatic layer for the purpose of suppressing generation of static electricity. The antistatic layer is formed by applying an antistatic resin composition.

Examples of the antistatic agent contained in the antistatic resin composition include various cationic antistatic agents having a cationic group such as a quaternary ammonium salt, a pyridinium salt and a tertiary to tertiary amino group. Anionic antistatic agents having anionic groups such as sulfonate groups, sulfate ester groups, phosphate ester groups, and phosphonate groups; amphoteric antistatic agents such as amino acid and amino sulfate esters; amino alcohols and glycerin And various surfactant-type antistatic agents such as nonionic antistatic agents such as polyethylene glycol and the like; and high molecular weight antistatic agents obtained by increasing the molecular weight of the above antistatic agents. Further, monomers or oligomers having a tertiary amino group or a quaternary ammonium group and polymerizable by ionizing radiation, for example, N, N
Polymerizable antistatic agents such as dialkylaminoalkyl (meth) acrylate monomers and their quaternary compounds can also be used.

In the antistatic layer, in addition to the antistatic resin composition, for improving the strength of the coating film of the antistatic layer, the adhesion to the substrate film, the water resistance, the solvent resistance, the blocking property and the like. A thermoplastic resin such as a thermoplastic polyester resin, an acrylic resin, or a polyvinyl resin as a binder and / or
Alternatively, it is preferable to contain a polymer compound such as a thermosetting resin such as a thermosetting acrylic resin, a urethane resin, a melamine resin, and an epoxy resin. Furthermore, as a crosslinking agent,
Methylolated or alkylolated melamine,
It is particularly preferable to include at least one of urea-based, glyoxal-based, acrylamide-based compounds, epoxy compounds, and polyisocyanates.

The surface specific resistance of the antistatic layer can be set arbitrarily according to the purpose of use. For example, in a case where ordinary dust does not adhere, 1 × 10 ¹¹ Ω /
□ It is about.

The method for forming the antistatic layer on the surface of the substrate film is not particularly limited, but a coating method is preferably used. For example, coating methods include air doctor coating, knife coating, rod coating, forward rotation roll coating, reverse roll coating, gravure coating, kiss coating, bead coating, slit orifice coating, and cast coating. Is mentioned.

The drying temperature of the antistatic layer is 60 to 1
The temperature may be in the range of 50 ° C, preferably in the range of 80 to 130 ° C. If the drying temperature is lower than 60 ° C., the curing time is prolonged, and the productivity is undesirably reduced.

The antistatic layer is formed on the surface of the base film, and the pressure-sensitive adhesive layer or the release layer may be formed on the antistatic layer, but on the surface of the base film opposite to the surface on which the antistatic layer is formed. May be formed.

FIGS. 1 to 3 show examples of the layer structure of the surface protective film provided with the pressure-sensitive adhesive layer of the present invention, and FIGS. 4 to 3 show examples of the layer structure of the surface protective film provided with the release layer of the present invention. 6 respectively. Here, 1 is a surface protective film provided with an adhesive layer, 2 is a surface protective film provided with a release layer, 11 is a polymer film, 12 is an adhesive layer, 13 is an antistatic layer, 14
Is a release layer.

The layer structure of the surface protective film provided with the pressure-sensitive adhesive layer shown here is as follows: pressure-sensitive adhesive layer / polymer film, pressure-sensitive adhesive layer / polymer film / antistatic layer, pressure-sensitive adhesive layer / antistatic layer / high It is a molecular film. Further, the layer structure of the surface protective film provided with a release layer includes a release layer / polymer film,
Release layer / polymer film / antistatic layer, release layer / antistatic layer / polymer film.

FIG. 7 shows a state in which the surface protective film provided with the pressure-sensitive adhesive layer and the surface protective film provided with the release layer of the present invention are adhered to an optical member. Here, 3 is an optical member, 15 is triacetyl cellulose (TAC), 1
Reference numeral 6 denotes a polarizing film, and 17 denotes an adhesive layer of a polarizing plate. Here, a surface protective film having a layer configuration of an adhesive layer / polymer film and a surface protective film having a layer configuration of a release layer / polymer film are used.

[0084]

EXAMPLES Next, the present description will be further described with reference to examples. However, the present invention is not limited to the following examples unless departing from the gist thereof. The methods for evaluating physical properties in the following examples and comparative examples are as follows.

<Maximum Distortion of Orientation Principal Axis> When the film is in a roll shape, a rectangle having a length of 500 mm and a full width in the width direction is cut out. Then, as shown in FIG. 8, a square of 100 mm square is cut out in three or more places including two vertexes of the rectangle and the center thereof in the width direction (tenter direction) including the same end side. In FIG. 8, 21 is the longitudinal direction, 22 is the width direction, 23 is the edge, 24 is the vertex, and 25 is the center of the vertex. Next, each orientation main axis was measured with a microwave transmission type molecular orientation meter, and the difference from 0 degree when each molecular orientation angle was smaller than 45 degrees, and the difference from 90 degrees when each molecular orientation angle was larger than 45 degrees. The maximum value was determined from the largest absolute value, and the maximum value was defined as the maximum strain of the orientation main axis. The microwave transmission type molecular orientation meter includes a molecular orientation meter (MOA-200) manufactured by Kanzaki Paper Co., Ltd.
1A) was used.

<Haze Value and Total Light Transmittance> Using a turbidity meter (NDH-300) manufactured by Nippon Denshoku Industries Co., Ltd., five samples were taken, and the average value was determined.

<Thermal Shrinkage at 120 ° C.> 100 per side
Draw a circle with a diameter of 50 mm centering on the intersection of the diagonal lines of the film cut into squares of mm, leave it in a hot air dryer heated to 120 ° C. for 30 minutes with no load, take it out, read the dimensional change with a digitizer, It was determined from the length (B) of the maximum position of contraction through the intersection of the diagonal lines by the following equation. Heat shrinkage at 120 ° C. = (50−B) / 50 × 10
0 (%)

Example 1 Polyethylene terephthalate containing 0.2% by weight of silica fine particles as inert particles was extruded through a film forming die onto a water-cooled rotary quenching drum to produce an unstretched film. This unstretched film is placed in a longitudinal direction of 124
The film was stretched 2.5 times at 90 ° C., then stretched 4.0 times at 90 ° C. in the width direction, and then annealed at 120 ° C. for 10 seconds. After exiting the tenter, remove both ends of the film from the end by 20
mm, and a portion having a small heat shrinkage was excised. Then, the film is rolled with ceramic rolls.
The material was heated to 00 ° C., and further subjected to a 3% relaxation treatment in the longitudinal direction while heating using four infrared heaters having a surface temperature of 700 ° C. Subsequently, the film is heated to 160 ° C with a ceramic roll.
While heating to 2%. Thereafter, both ends of the film are gripped with clips, heat-set at 200 ° C., and further cooled from 180 ° C. to 120 ° C.
A 4% relaxation treatment was performed in the width direction. Thus, a biaxially stretched polyethylene terephthalate film having a thickness of 38 μm was obtained. This biaxially stretched polyethylene terephthalate film has a maximum distortion of the orientation principal axis of 4 degrees and a haze value of 1
6.1%, the minimum MOR value was 2.74, the heat shrinkage at 120 ° C. was 0.27%, and the total light transmittance was 89%.

A coating solution obtained by adding 400 parts by weight of toluene as a solvent to 100 parts by weight of an ethylene-vinyl acetate adhesive was applied to the 38 μm-thick biaxially stretched polyethylene terephthalate film so as to have a dry film thickness of 10 μm. Then, the resultant was dried and solidified to obtain a surface protective film on which an adhesive layer was laminated. The polarizing plate using this surface protective film had good inspection properties, and also had good surface concealing properties for scratches, foreign matter, and the like caused by the biaxially stretched polyethylene terephthalate film.

Example 2 As an inert particle, polyethylene terephthalate containing 0.2% by weight of silica fine particles was extruded through a film forming die onto a water-cooled rotary quenching drum to produce an unstretched film. This unstretched film is vertically
The film was stretched 1.8 times at 90 ° C., and then 4.3 times at 90 ° C. in the width direction. Further, the film was heat-set in the width direction at 180 ° C., and subsequently subjected to a 4% relaxation treatment at 170 ° C. to obtain a biaxially stretched polyethylene terephthalate film having a thickness of 39 μm. A surface protection film was obtained in the same manner as in Example 1 except that this biaxially stretched polyethylene terephthalate film was used. In the obtained biaxially stretched polyethylene terephthalate film, the maximum distortion of the orientation main axis was 5 degrees and the haze value was 17.
The minimum MOR value was 2.79, the heat shrinkage at 120 ° C. was 1.22%, and the total light transmittance was 89%. A surface protective film having a pressure-sensitive adhesive layer laminated thereon was obtained in the same manner as in Example 1, and the inspection of the polarizing plate using the surface protective film was evaluated. The result was as good as in Example 1.

Example 3 A surface protection film was obtained in the same manner as in Example 1, except that the thickness of the biaxially stretched polyethylene terephthalate film was changed from 38 μm to 25 μm. In the biaxially stretched polyethylene terephthalate film having a thickness of 25 μm, the maximum distortion of the main orientation axis is 4 degrees, the haze value is 15.1%, and the minimum MOR value is 2.76,
The heat shrinkage at 20 ° C. was 0.25%, and the total light transmittance was 90%. In the same manner as in Example 1, a surface protective film on which an adhesive layer was laminated was obtained. The inspection properties of the polarizing plate using this surface protective film were as good as in Example 1.

Example 4 A surface protective film was prepared in the same manner as in Example 1, except that the content of the silica fine particles, which were inert particles, was changed from 0.2% by weight to 0.15% by weight. I got
In the biaxially stretched polyethylene terephthalate film, the maximum distortion of the main orientation axis is 4 degrees, the haze value is 12.4%, and the M
The lowest OR value was 2.76, the heat shrinkage at 120 ° C. was 0.25%, and the total light transmittance was 89%. In the same manner as in Example 1, a surface protective film on which an adhesive layer was laminated was obtained. The inspection properties of the polarizing plate using this surface protective film were as good as in Example 1.

Example 5 38 μm thick biaxially oriented polyethylene-2,6 containing 0.2% by weight of silica fine particles as inert particles instead of the biaxially oriented polyethylene terephthalate film
-Except using a naphthalate film, it carried out similarly to Example 1 and obtained the surface protection film. The above thickness 38μ
m, the biaxially oriented polyethylene-2,6-naphthalate film has a maximum distortion of 5 degrees and a haze value of 16.
The minimum MOR value was 2.83, the heat shrinkage at 120 ° C. was 0.29%, and the total light transmittance was 89%. In the same manner as in Example 1, a surface protective film on which an adhesive layer was laminated was obtained. The inspection properties of the polarizing plate using this surface protective film are good, and the biaxially stretched polyethylene-
The concealability of surface scratches, foreign matter, and the like caused by the 2,6-naphthalate film was also good.

Example 6 Polyethylene terephthalate containing 0.2% by weight of silica fine particles as inert particles was extruded through a film forming die onto a water-cooled rotary quenching drum to produce an unstretched film. 90 ° C in the width direction of this unstretched film
Then, annealing was performed at 120 ° C. for 10 seconds. After leaving the tenter, both ends of the film were trimmed at a position of 20 mm from the end, and a portion having a small heat shrinkage was cut off. Subsequently, the film was heated to 100 ° C. by a ceramic roll, and further subjected to a 3% relaxation treatment in the longitudinal direction while heating using four infrared heaters having a surface temperature of 700 ° C. Subsequently, a 2% relaxation treatment was performed while heating the film to 160 ° C. with a ceramic roll. Thereafter, both ends of the film were gripped with clips, subjected to a heat setting treatment at 220 ° C., and further subjected to a 3% relaxation treatment in the width direction while cooling from 180 ° C. to 120 ° C. Thus, a uniaxially stretched polyethylene terephthalate film having a thickness of 40 μm was obtained. This uniaxially stretched polyethylene terephthalate film has a maximum orientation distortion of 4 degrees, a haze value of 17.1%, and a minimum MOR value of 2.61 or 1.61.
The heat shrinkage at 20 ° C. is 0.8% and the total light transmittance is 8
9%. In the same manner as in Example 1, a surface protective film on which an adhesive layer was laminated was obtained. The inspection properties of the polarizing plate using this surface protective film were good, and the concealability of scratches, foreign matter, etc. in the uniaxially stretched polyethylene terephthalate film was also good.

Example 7 A biaxially oriented polyethylene terephthalate film having a thickness of 38 μm was obtained in the same manner as in Example 1. The obtained biaxially stretched polyethylene terephthalate film had a maximum distortion of the orientation principal axis of 4 degrees, a haze value of 16.1%, a minimum MOR value of 2.74, and a heat shrinkage of 0.2 at 120 ° C.
7% and the total light transmittance was 90%.

On one surface of the biaxially stretched polyethylene terephthalate film, a quaternary ammonium salt type cationic polymer compound (PAS10L, manufactured by Nitto Boseki Co., Ltd.)
Parts by weight, 50 parts by weight of copolymerized polyester resin, methylolated melamine resin (Sumitomo Chemical Co., Ltd .; SUMIM)
ALM-40W) (10 parts by weight) and epoxy-modified silicone (Shin-Etsu Chemical Co., Ltd .; Poln MF-18) (5 parts by weight) were mixed to prepare a 2% by weight coating solution for an antistatic layer. The solution was applied at a coating amount of 4 g / m ² (based on the amount of the coating solution), and dried by heating and curing at 120 ° C. for 1 minute to form an antistatic layer. Subsequently, an adhesive layer was formed on the surface of the biaxially stretched polyethylene terephthalate film on which the antistatic layer was not formed in the same manner as in Example 1 to obtain a surface protective film. The inspection properties of the polarizing plate using this surface protective film were as good as in Example 1. In addition, this surface protective film did not generate static electricity when peeled off, and had good adhesion with little adhesion of dust.

Example 8 In Example 7, the same pressure-sensitive adhesive layer as in Example 1 was formed on the surface of the biaxially stretched polyethylene terephthalate film on which the antistatic layer was formed to obtain a surface protective film. The inspection of the polarizing plate using this surface protective film was good. In addition, this surface protective film did not generate static electricity when peeled off, and had good adhesion with little adhesion of dust.

Example 9 In Example 1, instead of the ethylene-vinyl acetate-based pressure-sensitive adhesive, an addition-reaction-type release agent (manufactured by Shin-Etsu Chemical Co., Ltd .;
100 parts by weight of KS-778, a 30% solids solution in toluene) and a platinum catalyst (PL-50 manufactured by Shin-Etsu Chemical Co., Ltd.)
T) 1 part by weight was dissolved in toluene to prepare a toluene solution having a total solid content of 3% by weight (coating liquid for coating a release layer). 6 g / m ² (based on the amount of coating liquid) of this coating liquid for release layer
, And heated and dried at 120 ° C. for 1 minute and an addition polymerization reaction was carried out to prepare a surface protective film to be attached to the pressure-sensitive adhesive layer of the polarizing plate. The inspection properties of the polarizing plate using this surface protective film were as good as in Example 1.

Example 10 In Example 9, the addition reaction type release agent was replaced by U
V-curing release agent (X-62-, manufactured by Shin-Etsu Chemical Co., Ltd.)
5048), and the coating liquid for a release layer was coated at 6 g / m
² (based on the amount of coating liquid), and applied at 1.0 J / cm ²
UV cured under the conditions described above to obtain a surface protective film to be attached to the pressure-sensitive adhesive layer of the polarizing plate. The inspection of the polarizing plate using this surface protective film was good.

Example 11 In Example 9, a fluorine-based solvent (manufactured by 3M; FC-77 "Fluorinert") was used in place of the addition-reacting release agent.
As a diluting solvent and a fluorine-containing resin therein as a fluorine-containing acrylic resin (manufactured by Neos Corporation; RBX-725NF)
"Fleet") and fluorinated oil (Dupont; 1
57FS-M "Crytox") at a weight / solids ratio of 2
A coating solution having a composition of 0:80 and having a concentration of 3.0% by weight, which is uniformly dispersed, is applied so as to have a concentration of 0.4 μm / dry.
C. for 1 minute to obtain a surface protective film to be attached to the pressure-sensitive adhesive layer of the polarizing plate. The inspection of the polarizing plate using this surface protective film was good.

Example 12 In the same manner as in Example 7, the obtained biaxially stretched polyethylene terephthalate film with an antistatic layer was subjected to the same addition reaction type release as in Example 9 on the surface on which the antistatic layer was not formed. A layer was formed and a surface protective film to be attached to the pressure-sensitive adhesive layer of the polarizing plate was obtained. The inspection of the polarizing plate using this surface protective film was good. In addition, this surface protective film did not generate static electricity when peeled off, and had good adhesion with little adhesion of dust.

Example 13 In Example 12, an addition reaction-type release layer similar to that of Example 9 was formed on the surface of the biaxially stretched polyethylene terephthalate film on which the antistatic layer was formed, and the adhesive layer of the polarizing plate was formed. A surface protection film to be attached was obtained. The inspection of the polarizing plate using this surface protective film was good. In addition, this surface protective film did not generate static electricity when peeled off as in Example 12, and was good with little adhesion of dust.

Comparative Example 1 Polyethylene terephthalate containing 0.2% by weight of silica fine particles as inert particles was extruded through a film-forming die onto a water-cooled rotary quenching drum to produce an unstretched film. 90 ° C in the machine direction
Then, the film was stretched 3.0 times at 90 ° C. in the width direction. Further, the film was heat-set in the width direction at 200 ° C., and subsequently relaxed by 4% at 180 ° C. to obtain a biaxially stretched polyethylene terephthalate film having a thickness of 38 μm. A surface protection film was obtained in the same manner as in Example 1 except that this biaxially stretched polyethylene terephthalate film was used. In the biaxially stretched polyethylene terephthalate film, the maximum distortion of the main orientation axis is 17 degrees, and the haze value is 16.
2%, the minimum MOR value was 1.36, the heat shrinkage at 120 ° C. was 0.9%, and the total light transmittance was 89%.
In the same manner as in Example 1, a surface protective film on which an adhesive layer was laminated was obtained. In the polarizing plate using this surface protective film, the blackening density was uneven in the width direction, and a rainbow due to light interference caused by the surface protective film was observed in the width direction, and the inspection property was poor.

Comparative Example 2 A surface protective film was prepared in the same manner as in Example 1, except that the content of the silica fine particles as the inert particles was changed from 0.2% by weight to 0.06% by weight. I got
Here, the maximum distortion of the orientation main axis of the biaxially stretched polyethylene terephthalate film is 4 degrees, the haze value is 6.3%, the minimum MOR value is 2.76, the heat shrinkage at 120 ° C. is 0.25%, The total light transmittance was 89%. In the same manner as in Example 1, a surface protective film on which an adhesive layer was laminated was obtained. The inspection properties of the polarizing plate using this surface protective film were as good as in Example 1, but the surface was not sufficiently concealed for scratches and foreign matter due to the biaxially stretched polyethylene terephthalate film, and the yield was low. Decreased.

Comparative Example 3 A surface protective film was prepared in the same manner as in Example 1, except that the content of the silica fine particles as the inert particles was changed from 0.2% by weight to 0.35% by weight. I got
Here, the maximum distortion of the orientation main axis of the biaxially stretched polyethylene terephthalate film is 4 degrees, the haze value is 26.3%,
The minimum MOR value was 2.76, the heat shrinkage at 120 ° C. was 0.25%, and the total light transmittance was 89%.
In the same manner as in Example 1, a surface protective film on which an adhesive layer was laminated was obtained. The inspection properties of the polarizing plate using this surface protective film were poor due to insufficient blackening density.

[0106]

As described above, the polymer film of the present invention has a maximum distortion of the major axis of orientation of 7 degrees or less measured by a microwave transmission type molecular orientation meter and a haze value of 10 to 25%. By using, during inspection such as optical evaluation,
It is possible to make the defects of the inspection easier to see without peeling off the surface protection films provided on both sides of the inspection such as the polarizing plate and the retardation plate. Furthermore, it is not necessary to highly reduce the occurrence of scratches and foreign matter on the polymer film, and furthermore, by using an inexpensive resin having excellent overall performance, such as polyethylene terephthalate, it is possible to reduce costs and discard after inspection. It is suitable as a surface protection film.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing one example of a surface protective film provided with a pressure-sensitive adhesive layer of the present invention.

FIG. 2 is a cross-sectional view schematically showing one example of a surface protective film provided with a pressure-sensitive adhesive layer of the present invention.

FIG. 3 is a cross-sectional view schematically showing one example of a surface protective film provided with an adhesive layer of the present invention.

FIG. 4 is a cross-sectional view schematically showing one example of a surface protective film provided with a release layer of the present invention.

FIG. 5 is a cross-sectional view schematically showing one example of a surface protective film provided with a release layer of the present invention.

FIG. 6 is a cross-sectional view schematically showing one example of a surface protective film provided with a release layer of the present invention.

FIG. 7 schematically shows an example in which the surface protective film provided with the pressure-sensitive adhesive layer and the surface protective film provided with the release layer of FIGS. 1 and 4 are bonded to a polarizing plate as an example of an optical member. It is sectional drawing.

FIG. 8 is a schematic diagram of a sampling method in evaluating <maximum distortion of main orientation axis>.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Surface protective film provided with adhesive layer 2 Surface protective film provided with release layer 3 Optical member 11 Polymer film 12 Adhesive layer 13 Antistatic layer 14 Release layer 15 Triacetyl cellulose (TAC) 16 Polarizing film 17 adhesive layer of polarizing plate 21 longitudinal direction 22 width direction 23 edge 24 vertex 25 center of vertex

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) B32B 27/00 101 B32B 27/00 101 27/36 27/36 C09J 7/02 C09J 7/02 Z G02F 1 / 1335 510 G02F 1/1335 510 // C08L 101: 00 C08L 101: 00 (72) Inventor Harunobu Kuroiwa 2-8-8 Dojimahama, Kita-ku, Osaka-shi, Osaka F-term (reference) 2H091 FA08X FA08Z FA11X FA11Z FC08 FC09 FD06 FD15 GA16 GA17 LA04 LA07 LA09 4D075 CA07 CA22 CB06 DA04 DB36 DB48 DC24 EA21 EA35 EB16 EB43 4F071 AA01 AA43 AA46 AF30Y AF61Y AH12 AH16 BB07 BC01 AR10A00A01A10A01 CB00 EJ37A GB41 JA02A JA20A JB13C JB14C JG03C JL02 JL11B JL14D JN30A YY00A 4J004 AA05 AA06 AA07 AA09 AA10 AA11 AA14 AA15 AA16 AB01 CA03 CA04 CA05 CA06 CA07 CC03 DA02 DA04 DB03 FA04

Claims (14)

[Claims] 1. A polymer film comprising an organic polymer, wherein the polymer film has a maximum strain of 7 degrees or less in an orientation principal axis measured by a microwave transmission type molecular orientation meter, and a haze value of 10 to 10. 25% of a polymer film. 2. The polymer film according to claim 1, wherein a minimum value of a maximum / minimum ratio (MOR value) of microwave transmission intensity measured by a microwave transmission type molecular orientation meter is larger than 1.8. . 3. The polymer film according to claim 1, wherein the heat shrinkage at 120 ° C. is 5.0% or less. 4. The polymer film according to claim 1, wherein the polymer film is a uniaxially stretched polymer film.
The polymer film according to the above. 5. The polymer film according to claim 1, wherein the polymer film is a polyester film. 6. The polyester film according to claim 5, wherein the polyester film is a film composed of polyethylene terephthalate or a polyester mainly composed of polyethylene terephthalate.
The polymer film according to the above. 7. A surface protective film, wherein a pressure-sensitive adhesive layer is laminated on one surface of the polymer film according to any one of claims 1, 2, 3, 4, 5, and 6. 8. The surface protective film according to claim 7, wherein an antistatic layer is laminated on the surface of the polymer film opposite to the side of the pressure-sensitive adhesive layer. 9. The surface protective film according to claim 7, wherein an antistatic layer is laminated between the pressure-sensitive adhesive layer and the polymer film. 10. The method of claim 1, 2, 3, 4, 5, or 6.
A surface protective film, wherein a release layer is laminated on one surface of the polymer film according to any one of the above. 11. The surface protective film according to claim 10, wherein an antistatic layer is laminated on the surface of the polymer film opposite to the release layer side. 12. The surface protective film according to claim 10, wherein an antistatic layer is laminated between the release layer and the polymer film. 13. A surface protective film, wherein the release layer according to claim 10 is mainly composed of a silicone resin and / or a fluororesin. 14. The silicone resin according to claim 13,
A surface protective film comprising a thermosetting silicone resin or a radiation curing silicone resin as a main component.