WO2017006604A1 - Surface protective film - Google Patents

Abstract

This surface protective film 10 bonds to an adherend selected from optical members 20 or electronic members, and is used to protect the surface thereof, wherein: the surface protective film 10 is provided with a base material 11, and a pressure-sensitive adhesive layer 12 provided on one surface of the base material 11; and a portion of the pressure-sensitive-adhesive-layer-side surface (pressure-sensitive adhesive surface 15) of the surface protective film, in at least an annular region 16 surrounding a central portion 17, is a strong pressure-sensitive-adhesive portion, the other portion being a non-adhesive portion or a weak pressure-sensitive-adhesive portion that has lower adhesive force than does the strong pressure-sensitive adhesive portion.

Description

Surface protection film

The present invention relates to a surface protective film that is applied to the surface of various optical members and electronic members and used to protect the surface.

2. Description of the Related Art Conventionally, when assembling an electronic device or the like, a method of previously unitizing various electronic components and optical components and mounting them on a substrate or the like is widely known. As such a unitized optical member and electronic member, there are many known units such as a motor unit including an imaging module, a camera lens unit, a communication module, a sensor module, and a vibrator. A surface protective film is attached to these optical members and electronic members in order to prevent the surface from being damaged or dust from being attached during processing, assembly, inspection, transportation, or the like.

The surface protective film is generally formed by providing a pressure-sensitive adhesive layer on one surface of a base material, and is adhered to an adherend such as an optical member or an electronic member by the pressure-sensitive adhesive layer so as to cover the surface of the adherend. In addition to protecting, it is peeled off from the adherend when it is no longer necessary to protect the surface.
In general, an optical member such as a video sensor module has a light receiving portion constituted by a lens or the like. Therefore, in order to prevent the adhesive residue from being generated in the light receiving portion, the surface protective film may be formed with an uncoated portion without being applied with an adhesive on a portion that is applied to the light receiving portion (for example, Patent Document 1). reference).

Also known is an optical member that includes a lens and a lens holding member for holding the lens, and the lens holding member has an annular portion surrounding the lens. The surface protective film is used by being attached to the surface of the annular portion for such an optical member, thereby protecting the lens and the lens holding member.

Japanese Patent No. 4116607

By the way, in recent years, optical members have been reduced in size and precision, and it has been required to prevent not only the lens itself but also adhesive residue generated on the lens holding member. The adhesive residue on the holding member may not be sufficiently prevented.
In particular, the surface protective film is generally formed to be slightly larger than the annular portion so that the entire annular portion of the lens holding member is covered with the surface protective film. Therefore, the surface protective film is usually attached to the lens holding member so as to protrude outward from the outer peripheral portion of the annular portion. However, if the surface protective film is pasted so as to protrude from the outer peripheral portion of the lens holding material, an adhesive may be caught on the outer peripheral portion when the surface protective film is peeled off from the optical member, resulting in an adhesive residue. Similarly, adhesive residue may also occur in the inner peripheral portion of the lens holding member.

In addition, various coatings may be formed on the surface of the lens holding member, but the coating provided on the lens holding member may be fragile. Therefore, when the adhesive force of the surface protective film is too high, the coating film may be peeled off when the surface protective film is peeled off. Further, when the surface protective film is peeled from the lens holding member, a peeling failure may occur.

The present invention has been made in view of the above-described problems, and can protect the surface of the adherend made of an optical member or an electronic member while preventing the adhesive residue from occurring, and without causing defective peeling. It is an object of the present invention to provide a surface protective film capable of appropriately peeling a film from an adherend.

As a result of intensive studies, the present inventors have determined that, in the annular region surrounding the central portion of the adhesive surface of the surface protective film, a portion is a strong adhesive portion and the other portion has a weak adhesive strength lower than that of the strong adhesive portion. It has been found that the above-mentioned problems can be solved by using a part or a non-adhesive part, and the following present invention has been completed. That is, the present invention provides the following [1] to [12].
[1] A surface protective film that is applied to an optical member or an electronic member and used to protect the surface thereof,
A substrate and a pressure-sensitive adhesive layer provided on one surface of the substrate;
The surface of the surface protective film on the pressure-sensitive adhesive layer side is at least in the annular region surrounding the central part, and a part thereof is a strong adhesive part, and the other part is a weak adhesive part whose adhesive strength is lower than that of the strong adhesive part And a surface protective film which is at least one of a non-adhesive part.
[2] In the above [1], the pressure-sensitive adhesive layer is made of an energy ray-curable pressure-sensitive adhesive, and at least one of the weakly-adhesive portion and the non-adhesive portion is constituted by a portion cured by irradiation with energy rays. The surface protective film as described.
[3] The above [1] or [3], wherein the pressure-sensitive adhesive layer is partially provided on one surface of the base material, and a portion where the pressure-sensitive adhesive layer is not provided becomes the non-adhesive portion. 2].
[4] The surface on the pressure-sensitive adhesive layer side of the surface protective film has a pattern shape in which at least one of the weakly-adhesive portion and the non-adhesive portion and the strong-adhesive portion are alternately provided in at least the annular region. [1] The surface protective film according to any one of [3].
[5] In at least the annular region on the surface of the surface protective film on the pressure-sensitive adhesive layer side, at least one of the weakly-adhesive portion and the non-adhesive portion, and the strong-adhesive portion are a stripe shape, a lattice shape, a dot shape, The surface protection according to any one of the above [1] to [4], which is arranged in any pattern selected from a shape in which a plurality of wavy lines are arranged, a checkered pattern, and a shape in which various patterns are arranged in a plurality the film.
[6] Both the outer portion and the inner portion in the annular region are provided with at least one of the weakly-adhesive portion and the non-adhesive portion to be a weakly-adhesive region or a non-adhesive region, and between the outer portion and the inner portion. The surface protective film according to any one of the above [1] to [5], wherein an intermediate portion thereof is provided with the strong adhesive portion to form a strong adhesive region.
[7] Either one of the outer portion and the inner portion in the annular region is provided with the strong adhesion portion to become a strong adhesion region, and the other is provided with at least one of the weak adhesion portion and the non-adhesion portion. The surface protective film according to any one of [1] to [5], wherein the surface protective film is a weakly adhesive region or a non-adhesive region.
[8] The surface protective film according to [6] or [7], wherein the weakly adhesive region has a pattern shape in which at least one of the weakly adhesive part and the non-adhesive part and a strong adhesive part are alternately provided.
[9] The surface protective film according to [6] or [7], wherein the strong adhesion region has a pattern shape in which at least one of the weak adhesion portion and the non-adhesion portion and the strong adhesion portion are alternately provided.
[10] The optical member or the electronic member has an annular portion,
The surface protective film according to any one of the above [1] to [9], wherein the annular region of the surface protective film is bonded to the annular portion.
[11] Surface protection comprising: a member selected from either an optical member or an electronic member; and the surface protective film according to any one of [1] to [10], which is attached to a surface of the member. Member with film.
[12] A method for protecting the surface of the optical member or electronic member by applying the surface protective film according to any one of [1] to [10] above to the surface of the optical member or electronic member.

In the present invention, the surface protective film can be appropriately peeled off from the adherend without causing a peeling failure while preventing adhesive residue generated on the surface of the adherend consisting of an optical member or an electronic member. .

It is a top view which shows typically the surface at the side of the adhesive layer of the surface protection film which concerns on 1st Embodiment. In 1st Embodiment, it is sectional drawing which shows the surface protection film affixed on the to-be-adhered body. It is a top view which shows typically the surface by the side of the adhesive layer of the surface protection film which concerns on 2nd and 3rd embodiment. In 2nd and 3rd embodiment, it is sectional drawing which shows the surface protection film affixed on the to-be-adhered body. It is a top view which shows typically the surface at the side of the adhesive layer of the surface protection film which concerns on 4th Embodiment. In 4th Embodiment, it is sectional drawing which shows the surface protection film affixed on the to-be-adhered body. In 4th Embodiment, it is a top view which shows the example whose arrangement pattern of a weak adhesion part and a strong adhesion part is a grid | lattice form. In 4th Embodiment, it is a top view which shows the example whose arrangement pattern of a weak adhesion part and a strong adhesion part is dot shape. In 4th Embodiment, it is a top view which shows the example whose arrangement pattern of a weak adhesion part and a strong adhesion part is the shape which arranged the wavy line in multiple numbers. In 4th Embodiment, it is a top view which shows the example whose arrangement pattern of a weak adhesion part and a strong adhesion part is a checkered pattern. It is a top view which shows typically the surface at the side of the adhesive layer of the surface protection film which concerns on 5th Embodiment. It is a top view which shows typically the surface by the side of the adhesive layer of the surface protection film which concerns on 6th Embodiment. It is a top view which shows typically the surface at the side of the adhesive layer of the surface protection film which concerns on 7th Embodiment. It is a top view which shows typically the surface by the side of the adhesive layer of the surface protection film which concerns on the modification of 5th Embodiment.

[Surface protection film]
The surface protective film of the present invention is applied to an adherend selected from an optical member or an electronic member and used to protect the surface. Hereinafter, the surface protective film of the present invention will be described in detail using the first to seventh embodiments.

(First embodiment)
First, the surface protection film according to the first embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1 and 2, the surface protective film 10 includes a base material 11 and a pressure-sensitive adhesive layer 12 provided on one surface of the base material 11.

(Base material)
Although the base material 11 is not specifically limited, For example, it consists of a resin film. As the resin film, known ones can be used. Polyethylene film, polypropylene film, polybutylene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, poly Films such as butylene terephthalate film, polyurethane film, ethylene vinyl acetate film, ionomer resin film, ethylene / (meth) acrylic acid copolymer film, polystyrene film, polycarbonate film, fluororesin film, polyimide, polyethylene naphthalate is there. Moreover, the laminated film formed by laminating | stacking these bridge | crosslinking films and two or more films may be sufficient.

In the present embodiment, when a part of the pressure-sensitive adhesive layer 12 is cured by irradiation with energy rays as described later, the base material 11 preferably has transparency to the wavelength of the energy rays to be used. . For example, in the case where ultraviolet rays are used as energy rays, it is preferable that an ultraviolet transmissive film is used as the substrate 11. However, when the energy beam irradiation is performed from the opposite side of the base material 11 or when the adhesive layer 12 is not cured by being irradiated with the energy beam, the base material 11 needs to have transparency to the energy beam. Absent.
Furthermore, one or both of the base material 11 and the pressure-sensitive adhesive layer 12 to be described later can be colored so that the presence or absence of the surface protective film 10 can be easily determined in the work process.
The thickness of the substrate 11 is adjusted according to the performance required for the surface protective film 10 and is preferably 10 to 300 μm, more preferably 30 to 150 μm.

(Adhesive layer)
The pressure-sensitive adhesive layer 12 is made of an energy ray curable pressure sensitive adhesive or a non-energy ray curable pressure sensitive adhesive. The pressure-sensitive adhesive layer 12 is made of, for example, an energy ray-curable pressure-sensitive adhesive, and a part of the pressure-sensitive adhesive layer 12 is cured when irradiated with energy rays, and the adhesive force to the adherend is reduced. In such a case, the surface of the surface protective film 10 on the pressure-sensitive adhesive layer 12 side (also referred to as “adhesive surface 15”) is irradiated with an energy beam and an energy beam that is not irradiated with an energy beam and remains highly adhesive. And a weak adhesive part having a lower adhesive strength than that of the strong adhesive part.
Further, the pressure-sensitive adhesive layer 12 is not provided on a part of the pressure-sensitive adhesive surface 15, and the adhesive force can be reduced by reducing the contact area with the pressure-sensitive adhesive bonded to the adherend. In this case, the adhesive surface 15 includes a strong adhesive part provided with an adhesive and a non-adhesive part without an adhesive. When the pressure-sensitive adhesive layer 12 is not provided on a part of the pressure-sensitive adhesive surface 15, the pressure-sensitive adhesive layer 12 is usually made of a non-energy ray curable pressure sensitive adhesive, but may be made of an energy ray curable pressure sensitive adhesive.

The energy ray curable pressure-sensitive adhesive is cured by being irradiated with energy rays as described above, and the adhesive force is reduced. Specific examples of energy rays include ultraviolet rays and electron beams, but it is preferable to use ultraviolet rays.
Although it does not specifically limit as an adhesive used for an energy-beam curable adhesive, Acrylic adhesive, rubber adhesive, silicone adhesive, polyester adhesive, urethane adhesive, polyolefin adhesive, etc. However, the present invention is not limited to these, and any one can be appropriately selected and used. Of these, acrylic adhesives are preferred.
In addition to the adhesive component (main polymer) such as acrylic resin, rubber resin, silicone resin, polyester resin, urethane resin, polyolefin resin, etc., the pressure-sensitive adhesive is usually a crosslinking agent, if necessary. From a pressure-sensitive adhesive composition containing additives such as tackifiers, antioxidants, plasticizers, inorganic fillers, organic fillers, antistatic agents, flame retardants, colorants, ultraviolet absorbers, infrared absorbers, etc. It will be. The size of the filler is not limited regardless of the presence or absence of a modifying group. In consideration of dispersibility in the pressure-sensitive adhesive, the particle size is preferably 3 μm or less, and the addition amount is preferably 70% by mass or less with respect to the pressure-sensitive adhesive. Note that the adhesive component is a concept that widely includes polymers and the like that exhibit adhesiveness by addition of a plasticizing component, although the adhesive component itself has substantially no adhesiveness.

The energy ray curable pressure-sensitive adhesive generally contains a component having a photopolymerizable unsaturated group. Although it does not specifically limit as an energy beam curing type adhesive, For example, a X-type thing is used. The X-type energy ray-curable pressure-sensitive adhesive is a product in which a photopolymerizable unsaturated group is introduced into the main polymer (for example, acrylic polymer) of the pressure-sensitive adhesive itself (for example, in the side chain of the main polymer). .
The energy ray curable pressure sensitive adhesive may be a Y type energy ray curable pressure sensitive adhesive. The Y-type energy ray-curable pressure-sensitive adhesive is one in which an energy ray-polymerizable compound having a photopolymerizable unsaturated group is blended separately from the main polymer (for example, an acrylic polymer). Further, the energy ray curable pressure sensitive adhesive may be a combination of X type and Y type. That is, the energy ray curable pressure-sensitive adhesive may be one in which an energy ray polymerizable compound is blended and a photopolymerizable unsaturated group is introduced into at least a part of the main polymer.
The photopolymerizable unsaturated group is usually a group having a double bond, preferably a (meth) acryloyl group.

Moreover, it is preferable that the energy ray-curable pressure-sensitive adhesive contains a photopolymerization initiator. Examples of the photopolymerization initiator include photopolymerization initiators such as benzoin compounds, acetophenone compounds, acylphosphinoxide compounds, titanocene compounds, thioxanthone compounds, and peroxide compounds, and photosensitizers such as amines and quinones. More specifically, for example, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, 2 , 2-dimethoxy-1,2-diphenylethane-1-one, diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide, and the like. These photopolymerization initiators may be used alone or in combination of two or more.

On the other hand, the non-energy ray curable pressure-sensitive adhesive does not contain a component having a photopolymerizable unsaturated group, and further usually does not contain a photopolymerization initiator, and the adhesive strength is reduced even when irradiated with energy rays. Does not stick. The non-energy ray curable pressure-sensitive adhesive contains the above-described pressure-sensitive adhesive component, and further contains the various additives as necessary.
The thickness of the pressure-sensitive adhesive layer 12 is not particularly limited, and is preferably 3 to 50 μm, more preferably 5 to 30 μm. It becomes easy to improve the adhesiveness with respect to a to-be-adhered body because the thickness of an adhesive layer exists in the said range.

At least in the annular region 16, the adhesive surface 15 is a strong adhesive part, and the other part is a weak adhesive part or a non-adhesive part. The annular region 16 means a region other than the central portion 17 of the adhesive surface 15 and surrounding the central portion. Here, the central portion 17 is a region surrounded by a dotted imaginary line in FIG.
In the present specification, the strong adhesive part means a part having a higher adhesive force than the weak adhesive part or the non-adhesive part, and does not necessarily mean that the absolute adhesive value is high. Absent.

Hereinafter, this embodiment will be described in more detail. In the following description of the embodiment, the pressure-sensitive adhesive layer 12 is made of an energy ray-curable pressure-sensitive adhesive as an example, and an example in which a weak pressure-sensitive adhesive portion is cured by energy rays will be described. It is good also as an aspect which provides a non-adhesive part, without providing the adhesive layer 12 in a part. Therefore, in the following description, the energy ray-curable pressure-sensitive adhesive layer can be appropriately read as a non-energy ray-curable pressure-sensitive adhesive, and the weakly-adhesive portion can be read as a non-adhesive portion.

The weak adhesive portion is provided on both the outer portion 16A and the inner portion 16B in the annular region 16. On the other hand, the strong adhesion portion is provided in an intermediate portion 16C between the outer portion 16A and the inner portion 16B. For this reason, the outer portion 16A and the inner portion 16B become weak adhesive regions having lower adhesive strength as regions than the intermediate portion 16C, and the intermediate portions 16C become strong adhesive regions having higher adhesive strength as regions.

More specifically, the outer portion 16A constitutes the outer peripheral edge 15A of the pressure-sensitive adhesive surface 15 and is a ring-shaped region, and the pressure-sensitive adhesive layer 12 in the region is cured, and is composed of a weak pressure-sensitive adhesive portion. The intermediate portion 16C is an annular region in contact with the inner periphery of the outer portion 16A, and the pressure-sensitive adhesive layer 12 is not cured by energy rays and is composed of a strong adhesive portion. Further, the inner portion 16B is a region in contact with the inner periphery of the intermediate portion 16C, and is configured by a weak adhesive portion by curing the adhesive layer 12 in the same manner as the outer portion 16A.
In the present embodiment, the central portion 17 is formed of a weak adhesive portion, like the inner portion 16B. For this reason, the inner region of the intermediate portion 16C (that is, the central portion 17 and the inner portion 16B) is all constituted by a weak adhesive portion. However, the center part 17 may be comprised not by the weak adhesion part but by the strong adhesion part.

In the present specification, the central portion 17 is a virtual region having an arbitrary width including the geometric center of gravity when the adhesive surface 15 is viewed in plan view. Xr) defined in an arbitrary region within a range of less than In addition, r means the distance from the center of gravity of the adhesive surface 15 when viewed in plan to each point of the outer peripheral edge 15A of the adhesive surface 15, and is a radius when the adhesive surface 15 is a circle. a is a positive number selected from greater than 0 and less than 1. a is preferably defined as 0.05 to 0.65, and more preferably 0.1 to 0.6.
As will be described later, the annular region 16 is a region that is usually an adhesive surface that is bonded to an adherend that is an optical member or an electronic member, but a is defined to be equal to or less than the above upper limit values. The annular region 16, that is, the bonding surface, ensures a certain area. Therefore, the sticking property of the surface protective film is improved.

In the present embodiment, the distance W1 from the outer periphery to the center of gravity of the annular intermediate portion 16C (that is, the outer diameter / 2 of the intermediate portion 16C) is such that the ratio (W1 / r) to the distance r is 0.4-0. 95 is preferable, and 0.5 to 0.8 is more preferable. By setting the ratio of the distance W1 to be equal to or less than the above upper limit value, the area of the weak adhesive portion (particularly, the outer portion 16A) in the annular region 16 (that is, the adhesive surface) can be easily increased to some extent, and a peeling failure may occur. It becomes easy to prevent the adhesive residue from occurring. Moreover, by setting it as the said lower limit or more, it is difficult for the area of a weak adhesion part to become large unnecessarily more, and it is prevented that insufficient adhesion arises.
Further, the distance W2 from the outer periphery to the center of gravity of the inner portion 16B (that is, the outer diameter / 2 of the inner portion 16B) has a ratio (W2 / r) to the distance r of 0.1 to 0.7. Preferably, it is 0.15 to 0.65.
By setting the ratio of the distance W2 to be equal to or less than the above upper limit value, it becomes easy to secure a certain area to adhere to the adherend with strong adhesive force, and it becomes easy to prevent insufficient adhesion. On the other hand, by setting it to the above lower limit value or more, it is possible to prevent an area that adheres to the adherend with a strong adhesive force from being unnecessarily large, and it is difficult to cause peeling failure and adhesive residue.

The pressure-sensitive adhesive layer 12 preferably has a pressure-sensitive adhesive strength before curing with energy rays (that is, a pressure-sensitive adhesive strength of a strong pressure-sensitive adhesive portion) of 800 to 16000 mN / 25 mm, more preferably 1000 to 10000 mN / 25 m, and more preferably 1000 to 5000 mN. More preferably, it is / 25 mm. When the adhesive strength of the strong adhesive portion is 800 mN / 25 mm or more, the adhesive strength of the surface protective film 10 to the optical member and the electronic member is increased, and the protective performance is improved. Moreover, by setting it as 16000 mN / 25mm or less, it becomes easy to make the adhesive force after energy beam hardening (namely, adhesive force of a weak adhesive part) a desired magnitude | size. The adhesive strength before energy ray curing can be adjusted by the type of adhesive component, the type and amount of functional groups possessed by the adhesive component, the amount of crosslinking agent used, and the like.

The pressure-sensitive adhesive layer 12 preferably has an adhesive strength after energy ray curing (that is, the adhesive strength of the weak adhesive portion) of 50 to 800 mN / 25 mm, more preferably 100 to 700 mN / 25 mm. More preferably, it is ˜300 mN / 25 mm. When the adhesive strength after energy ray curing is in such a range, the adhesive strength of the annular region 16 is prevented from increasing, and the occurrence of adhesive residue is prevented. Further, the surface protective film 10 can be peeled off from the adherend with a relatively small force. Therefore, the peeling performance is improved, and the surface coating provided on the optical member or the electronic member is prevented from being peeled when the surface protective film is peeled off.
The adhesive strength after energy beam curing can be controlled by the type and amount of the energy beam polymerizable compound and the amount of unsaturated groups introduced into the adhesive component.

The method for measuring the peeling force described above is specifically performed by the following method.
The pressure-sensitive adhesive strength before energy ray curing (that is, the pressure-sensitive adhesive strength of the strong pressure-sensitive adhesive portion) is a 25 mm wide × 250 mm wide pressure-sensitive adhesive sheet comprising a base material and a pressure-sensitive adhesive layer. The sample is cut into lengths and attached to the surface of a polycarbonate plate as an adherend with a 2 kg roller in an environment of 23 ° C. and 50% relative humidity. After standing for 20 minutes in an environment of 23 ° C. and 50% relative humidity, the peel force when peeling the adhesive sheet from the adherend at a tensile rate of 300 mm / min and a peel angle of 180 ° was measured, and before energy ray curing Adhesive strength of
Moreover, the adhesive strength after energy curing (that is, the adhesive strength of the weak adhesive portion) is the same as that used when forming the weak adhesive portion on the adhesive sheet after attaching the sample to the adherend and allowing it to stand for 20 minutes. Energy rays are irradiated on the entire pressure-sensitive adhesive layer from the substrate side under conditions, and then the peel force is measured by the same method as the adhesive force before energy ray curing to obtain the adhesive force after energy ray curing.

Further, in the present specification, when “adhesive strength as a region” is described, it means the adhesive strength of the entire region. Accordingly, when the target area is a mixture of the weak adhesive part and the strong adhesive part as in the weak adhesive area of the fifth to seventh embodiments, the “area” of the area (for example, the weak adhesive area) "Adhesive strength as" was produced with the same material and processing method as the surface protective film, and the strong adhesive part and the weak adhesive part were formed by the same pattern and the same method as the area (for example, weak adhesive area). The adhesive strength of the sample (adhesive sheet) was measured. Specific examples of the method for measuring the adhesive strength include the following methods.
In order to irradiate the surface protective film with energy rays in a desired pattern shape, a mask that is shielded from light is applied to a portion where energy ray curing is not desired, and energy rays are irradiated through the mask. As a result, a sample is produced in which energy rays are not irradiated on the portion shielded by the mask and energy rays are irradiated on the portion not shielded. That is, the sample partially has a strong adhesive portion and partially has a weak adhesive portion. This sample is cut to the size of the sample for measuring the adhesive strength, and the adhesive strength is measured in the same manner as the measurement of the adhesive strength before energy ray curing.
On the other hand, when the target region is a strong adhesive region or a weak adhesive region composed of a strong adhesive portion or a weak adhesive portion alone, the adhesive force itself of the strong adhesive portion or the weak adhesive portion is “adhesive strength as a region”. "
As will be described later, when the weak adhesive portion and the strong adhesive portion are mixed, the adhesive strength as the weak adhesive region is preferably 500 to 15000 mN / 25 mm, more preferably 700 to 9000 mN / 25 mm, and still more preferably. 750 to 4500 mN / 25 mm.

(Peeling sheet)
Further, a release sheet (not shown) may be attached to the surface of the pressure-sensitive adhesive layer 12 of the surface protective film 10 and protected by the release sheet. As a release sheet, one side of a resin film such as polyethylene terephthalate, polyethylene naphthalate, polypropylene, polyethylene, or paper substrate is a silicone release agent, a fluorine release agent, an alkyd release agent, a polyolefin release agent, a rubber release agent. Although what was peel-processed with release agents, such as an agent, can be used, it is not limited to these. A plurality of the surface protection films 10 may be provided on one release sheet having a size sufficiently larger than the surface protection film 10. When the surface protective film 10 is used, it is peeled off from the release sheet and attached to the adherend.

(Surface protection film)
The surface protective film 10 is used by being affixed to an optical member or an electronic member as described above. At this time, at least a part of the annular region 16 of the adhesive surface 15 is an optical member or an electronic member. It becomes an adhesive surface to be adhered to. Thereby, the adhesion surface adhered to the adherend of the surface protective film 10 can have both a weakly adhesive part and a strong adhesive part.
Therefore, since the area of the adhesion surface (the area of the strong adhesion part) bonded to the adherend with high adhesive force can be reduced, the increase in the adhesion force to the adherend of the entire surface protective film 10 is suppressed, It becomes possible to suppress adhesive residue.

When the surface protection film 10 is used, it is sufficient that the annular region 16 is adhered to the adherend, and the central portion 17 may or may not be adhered to the adherend. However, the part of the adherend corresponding to the central portion 17 is the central position of the optical member or electronic member to be protected, and a lens, various precision parts, and the like are often provided. Lenses and various precision parts come into contact with the adhesive, and if the adhesive is transferred, defects and performance deterioration are likely to occur. Therefore, the optical member or the electronic member is less likely to be defective when the central portion 17 is not in contact with the adherend.
Therefore, for example, as shown in FIG. 2, the surface protective film 10 may have the central portion 17 swelled on the side opposite to the adhesive surface 15 side. Thus, when the center part 17 swells, it becomes easy to prevent transfer of the adhesive to various lenses and precision parts.
However, the surface protective film 10 may be formed in a planar shape. Even if it is formed in a planar shape, if the central portion 17 is constituted by a weakly adhesive portion like the inner portion 16B, the adhesive of the central portion 17 is difficult to transfer to the adherend, such as lenses and precision parts. In many cases, defects do not occur even when contacting the adherend. Further, when the part of the adherend provided at the position corresponding to the central portion 17 is at a position lower than the adherend surface such as an annular portion described later, the surface protection film 10 is attached to the adherend even in a planar shape. Contact is prevented.

The surface protective film 10 is preferably of a small size so that it can be appropriately used as a protective film for a miniaturized electronic member or optical member. Specifically, the film area of the surface protection film 10 is preferably 20 cm ² or less. On the other hand, the lower limit of the film area is not particularly limited, but is preferably 0.05 cm ² or more from the viewpoint of practicality and workability. The film area is more preferably from 0.1 to 10 cm ² , further preferably from 10 to 80 mm ² .
In addition, although a film area means the area of the base material 11, when there is an unevenness | corrugation as shown in FIG. 2 in part of the surface protection film 10, it is an apparent area of the base material 11 when planarly viewed. is there.
The shape of the surface protective film 10 is not particularly limited, but when viewed in plan, it is a circle, an ellipse, a square such as a square or a rectangle, or a polygon other than a rectangle.

(Method for producing surface protective film)
Although the manufacturing method of the surface protection film 10 of this embodiment is not specifically limited, For example, it can manufacture with the following method.
First, the pressure-sensitive adhesive layer 12 is formed on the substrate 11. Specifically, the energy ray curable pressure-sensitive adhesive diluted with an appropriate solvent as necessary is applied on the release sheet so as to have a predetermined dry film thickness, and then dried to form a pressure-sensitive adhesive layer. A substrate may be attached to the pressure-sensitive adhesive layer. In addition, an energy ray-curable pressure-sensitive adhesive diluted with an appropriate solvent as needed may be directly applied to a substrate and then dried to form a pressure-sensitive adhesive layer.
Then, a weak adhesive part is formed in the adhesive layer 12. The formation of the weakly-adhesive part is not particularly limited, but for example, a known irradiation is performed via a mask having an opening having a shape matching the weakly-adhesive part or a light-shielding member having a light-shielding part having a shape corresponding to the strong-adhesive part. The adhesive layer 12 is irradiated with energy rays from the apparatus. The energy rays may be applied to the pressure-sensitive adhesive layer 12 from the base material 11 side through the base material 11, or from the opposite side of the base material 11. When irradiating from the opposite side of the base material 11 and the pressure-sensitive adhesive layer 12 is protected by the release sheet, the energy rays are applied to the pressure-sensitive adhesive layer through the release sheet.
Moreover, in order to produce the surface protection film in which the adhesive was partially applied, the non-adhesive part can be formed together with the strong adhesive part by performing screen printing or inkjet printing.
Further, a punching process may be performed before or after the formation of the weak adhesive portion. The punching process may be performed, for example, on the laminate of the base material 11 and the pressure-sensitive adhesive layer 12 provided on the release sheet. By this punching process, the shape of the surface protection film 10 is made circular as described above. . Moreover, you may form an unevenness | corrugation in the surface protective film 10 suitably by stamping etc. at arbitrary timings.

(Optical member or electronic member)
As an optical member or an electronic member protected by the surface protective film 10, an imaging module (for example, a camera module) in which an imaging sensor such as one or two or more lenses and a CCD, a CMOS, etc. are housed in a housing or a package; Examples include a lens unit in which a lens is held by a lens holding member such as a lens barrel; a light emitting element unit having a light emitting element such as an LED; a motor unit such as a vibrator; a communication module, a sensor module, and the like.

The optical member refers to an optical component that receives or emits light, or includes an optical component that transmits light. Among the above, an imaging module, a lens unit, a light emitting element unit, a communication module that transmits or receives an optical signal, An example of the optical member is an optical sensor module. The electronic member usually includes at least a part of an electric circuit and includes an electronic component that transmits or receives an electric signal, an electronic component that processes an electric signal, an electronic component that operates by an electric signal or electric power, and the like. Among them, a motor unit such as an imaging module, a light emitting element unit, and a vibrator, a communication module that transmits or receives an electrical signal, various sensor modules, and the like are specific examples of the electronic member. Note that a communication module, an optical sensor module, an imaging module, a light emitting element unit, and the like that transmit or receive optical signals are members that are both electronic members and optical members.
Moreover, it is preferable that the optical member or the electronic member is, for example, one in which the electronic component or the optical component is housed in a package or a housing or supported by a support member. Moreover, it is preferable that a part of electronic component or optical component is exposed on the surface, and the surface protection film is used, for example, to protect the exposed component.

An optical member or an electronic member (also referred to as “member with a surface protective film”) to which the surface protective film 10 is attached is processed, attached to another member, inspected, or transported, etc. The protective film 10 protects the surface of the adherend composed of an optical member or an electronic member in these steps. The surface protective film 10 is peeled off and removed from the adherend when it is no longer necessary to protect the adherend.

Hereinafter, an example of the usage method of the surface protection film 10 when the surface protection film 10 of this embodiment is stuck and used for the optical member 20 shown in FIG. 2 is demonstrated.
Here, the optical member 20 is a lens unit, an imaging module, or the like, and includes at least a lens 21 that constitutes a light receiving unit and a lens holding member 22 that holds the lens 21. The lens holding member 22 has an annular portion 23 provided so as to surround the lens. The material of the lens holding member 22 and the annular portion 23 is not particularly limited, but a lightweight and high-strength material is preferable in order to satisfy recent demands for downsizing and weight reduction of equipment. Furthermore, a coating or a coating can be provided on the surface of the lens holding member 22, for example, the front surface of the annular portion 23, for various required performances required for the optical member such as concealability, light absorption, and light reflection.
The annular portion 23 is an annular shape in FIG. 2, but is not limited to the annular shape, and may have an elliptical annular shape, a rectangular shape, a rectangular shape such as a rectangular shape, a polygonal shape other than a rectangular shape, and other annular shapes. The annular portion 23 is a member having a certain height, and the outer peripheral portion 23 </ b> A and the inner peripheral portion 23 </ b> B respectively constitute the outer peripheral surface and the inner peripheral surface of the lens holding member 22.

The surface protection film 10 is affixed to the optical member 20 such that the annular region 16 adheres to the front surface 23F of the annular portion 23. The surface protective film 10 attached in this way protects the annular portion 23 and the lens 21 disposed inside the annular portion 23.
Further, the surface coating 24 provided on the front surface 23F of the annular portion 23 has a relatively low coating strength and is often fragile. However, the annular region 16 bonded to the annular portion 23 has a strong adhesive portion and a weak adhesive portion. And the area bonded to the adherend with high adhesive force is reduced. Therefore, even when the fragile surface coating 24 is provided, it is prevented that the surface protective film 10 is peeled off when the surface protective film 10 is peeled off.

It is preferable that the surface protective film 10 has a shape corresponding to the adherend to which the surface protective film 10 is attached. That is, if the adherend to which the surface protective film 10 is attached has an annular portion 23 as shown in FIG. 2, the surface protective film preferably also exhibits a circular shape. In addition, if the annular portion 23 is a quadrangular ring, the surface protective film 10 preferably has a quadrangular shape.
As described above, since the surface protective film 10 has a shape corresponding to the shape of the adherend, the optical member 20 can be efficiently protected by the surface protective film 10.

Further, the surface protection film 10 is more than the outer periphery of the front surface 23F of the annular portion 23 so that the front surface 23F (attachment surface) of the annular portion 23 which is the attachment surface can be completely covered with the surface protection film 10. It is preferable that the circumference is large. When the surface protective film 10 having such a size is used, the entire front surface 23F of the annular portion 23 is protected by the surface protective film 10 even when there is a slight misalignment when the surface protective film 10 is attached to the adherend. It becomes possible to do.

In addition, as shown in FIG. 2, the surface protective film 10 has an outer portion 16 </ b> A configured with a weak adhesive portion disposed on the outer peripheral portion 23 </ b> A of the annular portion 23 and an inner portion 16 </ b> B configured with a weak adhesive portion. Is preferably affixed to the optical member 20 so as to be disposed on the inner peripheral portion 23B of the annular portion 23.
When the surface protective film 10 is peeled from the optical member 20, the pressure-sensitive adhesive layer 12 may be caught on the outer peripheral portion 23A or the inner peripheral portion 23B of the annular portion 23, but the outer portion 16A and the inner portion 16B are energy rays. Since it is comprised from the weak adhesive part hardened | cured by, even if the adhesive layer 12 is caught, it becomes difficult to produce an adhesive residue. On the other hand, since the intermediate portion 16 </ b> C configured by the strong adhesion portion is bonded to the front surface 23 </ b> F of the annular portion 23, it is possible to improve the adhesiveness of the surface protective film 10 to the annular portion 23.

In FIG. 2, the example in which the adherend to which the surface protective film 10 is attached is the optical member 20 having the lens 21, but may be an optical member of another form or an electronic member. May be. However, as described above, the adherend preferably includes a component to be protected such as a lens and an annular portion provided so as to surround the component. According to such a configuration, it is possible to appropriately protect the annular portion and the parts to be protected.

According to the surface protective film 10 of the first embodiment described above, it is possible to prevent adhesive residue from being generated on the surface of the optical member or electronic member that is the adherend. In addition, the surface protective film 10 can be appropriately peeled off from the adherend without peeling off the coating 24 on the surface of the adherend or causing poor peeling.

(Second Embodiment)
3 and 4 show a surface protective film according to a second embodiment of the present invention. Hereinafter, the difference between the surface protective film according to the second embodiment and the first embodiment will be described. In addition, detailed description of each member which abbreviate | omits description in 2nd Embodiment is the same as that of 1st Embodiment. Moreover, in each embodiment demonstrated below, the same code | symbol is attached | subjected and demonstrated to a corresponding member.

In the first embodiment, the annular region 16 of the adhesive surface 15 is composed of an outer part composed of a weak adhesive part, an intermediate part composed of a strong adhesive part, and an inner part composed of a weak adhesive part. In the present embodiment, the outer portion 16X of the annular region 16 is provided with a weak adhesive portion and becomes a weak adhesive region, and the inner portion 16Y is provided with a strong adhesive portion and becomes a strong adhesive region. It consists of two areas.

More specifically, the outer portion 16X of the annular region 16 constitutes the outer peripheral edge 15A of the adhesive surface 15 and is an annular region, and the adhesive layer 12 in the region is cured, so that weak adhesion is achieved. It consists of parts. The inner portion 16Y is a region in contact with the inner periphery of the outer portion 16X, and the pressure-sensitive adhesive layer 12 in the region is not cured and is formed of a strong adhesive portion.
In the present embodiment, the central portion 17 is composed of a strong adhesive portion, like the inner portion 16Y. For this reason, the regions other than the outer portion 16X of the adhesive surface 15 (that is, the central portion 17 and the inner portion 16Y) are all configured by the strong adhesive portion. However, the center part 17 may be comprised not by a strong adhesion part but by a weak adhesion part, and may be comprised from what mixed the weak adhesion part and the strong adhesion part.

The distance W3 (outer diameter of the inner portion 16Y) from the outer periphery to the center of gravity of the inner portion 16Y is preferably such that the ratio (W3 / r) to the distance r is 0.1 to 0.7, preferably 0.15 to 0. More preferred is .65. By setting the distance W3 to be equal to or less than the above upper limit value, the area of the weak adhesive portion on the adhesion surface can be easily increased to a certain extent, and it is easy to prevent the occurrence of peeling failure and the occurrence of adhesive residue. Moreover, by setting the distance W3 to be equal to or more than the lower limit value, it is possible to prevent the area of the weak adhesive portion from becoming larger than necessary and causing insufficient adhesion.

The surface protective film 10 according to the present embodiment is such that the annular region 16 is adhered to the annular portion 23 and attached to the optical member 20 as in the first embodiment, but is shown in FIG. As described above, the outer portion 16X formed of the weakly adhesive portion is disposed on the outer peripheral portion 23A of the annular portion 23, and the inner portion 16Y formed of the strong adhesive portion is disposed on the inner peripheral portion 23B of the annular portion 23. As described above, it is preferable that the annular portion 23 is attached. In the present embodiment, the outer portion 16X disposed on the outer peripheral portion 23A is thus made of a weak adhesive portion, so that the adhesive residue generated when the adhesive layer 12 is caught on the outer peripheral portion 23A can be more effectively prevented. .

(Third embodiment)
Next, the difference between the surface protective film according to the third embodiment and the second embodiment will be described. In addition, the part which abbreviate | omits description in this embodiment is the same as that of 2nd Embodiment.
In the second embodiment, the outer portion 16X of the annular region 16 is composed of a weak adhesive portion and becomes a weakly adhesive region, and the inner portion 16Y is composed of a strong adhesive portion and becomes a strong adhesive region. In the form, the outer portion 16X is composed of a strong adhesion portion and becomes a strong adhesion region, and the inner portion 16Y is composed of a weak adhesion portion and becomes a weak adhesion region.

As described above, in this embodiment, the strong adhesion region and the weak adhesion region are replaced from the second embodiment, but also in this embodiment, the annular region 16 of the surface protection film 10 is It has both a weak adhesive part and a strong adhesive part. As described above, the annular region 16 is usually an adhesive surface that is adhered to the adherend. Accordingly, even when the surface protective film 10 of the present embodiment is used, it is possible to suppress the adhesive residue on the adherend and to improve the peeling performance.

Also in the present embodiment, the annular region 16 has the outer portion 16X configured by the strong adhesive portion disposed on the outer peripheral portion 23A of the annular portion, and the inner portion 16Y configured by the weak adhesive portion formed by the annular portion 23. It is preferable to adhere to the annular portion 23 so as to be disposed on the inner peripheral portion 23B. As described above, when the inner portion 16Y disposed on the inner peripheral portion 23B becomes a weak adhesion region, in the present embodiment, it is possible to particularly effectively prevent adhesive residue generated by the adhesive layer 12 being caught on the inner peripheral portion 23B. . That is, as in the first to third embodiments described above, by making at least one of the inner part or the outer part of the annular region 16 a weakly adhesive region, it becomes easy to effectively prevent adhesive residue on the annular portion. .

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described with reference to FIGS. Note that the detailed description of each member whose description is omitted in the fourth embodiment is the same as in the first to third embodiments. In FIGS. 5 to 10, black portions indicate portions that are cured by irradiation with energy rays (that is, weakly adhesive portions).

In the first to third embodiments described above, the entire region in a certain range (for example, the outer portion 16A of the annular region 16 and the like) is cured to form the weak adhesive portion. A weak adhesive portion is provided depending on the pattern shape.
Specifically, as shown in FIGS. 5 and 6, the adhesive surface 15 includes a plurality of linear strong adhesive portions and a plurality of linear weak adhesive portions, which are alternately provided and stripes. Arranged in a pattern.

In the fourth embodiment, the stripe pattern is arranged over the entire adhesive surface 15 (that is, both the central portion 17 and the annular region 16). Therefore, the annular region 16 also includes the above-described embodiments. Similarly, a weak adhesive part and a strong adhesive part are provided. As described above, the annular region 16 is usually a region that is adhered to the adherend and becomes an adhesive surface. Therefore, even in this embodiment, it is possible to appropriately peel the surface protective film from the adherend while preventing the adhesive residue and without peeling off the coating on the surface of the adherend or causing poor peeling. become.

In addition, the adhesive surface 15 in 4th Embodiment does not need to arrange | position a weak adhesion part and a strong adhesion part with a striped pattern, and may be arrange | positioned with another pattern. For example, as shown in FIG. 7, the weak adhesive portion obtained by curing the adhesive layer with energy rays is arranged in a lattice shape, and the portion between the lattices is arranged in a lattice shape pattern that becomes a strong adhesive portion. May be. In the lattice pattern, the strong adhesion portions may be arranged in a lattice shape, and a portion between the lattices may be a weak adhesion portion.

Further, as shown in FIG. 8, a dot-shaped pattern in which a plurality of dot-like weak adhesive portions are scattered on the adhesive surface 15 (the central portion 17 and the annular region 16) and the other portions are formed of strong adhesive portions. May be arranged. However, in the dot shape pattern, a plurality of dots may be formed as a strong adhesive portion, and other portions may be configured as a weak adhesive portion. In FIG. 8, the shape of the dot is shown as a circle, but is not particularly limited, and may be various polygons such as an ellipse, a triangle, a quadrangle, and a pentagon, and other shapes.

Further, the strong adhesive portion and the weak adhesive portion may constitute a pattern having a shape in which a plurality of wavy lines are arranged. That is, as shown in FIG. 9, a plurality of wavy lines composed of weak adhesive portions may be arranged, and the strong adhesive portion and the weak adhesive portion may be arranged on the adhesive surface 15 so that the portion between them is a strong adhesive portion. . Alternatively, a plurality of wavy lines composed of weak adhesive portions may be arranged, and the strong adhesive portion and the weak adhesive portion may be arranged on the adhesive surface 15 so that a portion therebetween becomes a strong adhesive portion. In FIG. 9, an example in which the wavy line is a rectangular wave line is shown, but the wave line is not limited to a rectangular wave, and may be a triangular wave, a sinusoidal waveform, or the like.
Further, as shown in FIG. 10, the strong adhesive portion and the weak adhesive portion may be arranged in a checkered pattern.

Furthermore, it may be a shape in which a plurality of various geometric patterns such as floral patterns are arranged. In this case, various patterns may be configured with a strong adhesive portion, and other portions may be configured with a weak adhesive portion. Various patterns may be configured with a weak adhesive portion, and the other portions may be configured with a strong adhesive portion. It may be configured.
However, the adhesive surface 15 preferably has a pattern shape in which strong adhesive portions and weak adhesive portions are alternately provided, as shown in FIGS. 5 and 7 to 10. When the strong adhesive portion and the weak adhesive portion are alternately provided, the weak adhesive portion is sandwiched between the strong adhesive portions, so that adhesion failure due to the weak adhesive portion hardly occurs. In addition, since the strong adhesive portion is sandwiched between the weak adhesive portions, peeling failure caused by the strong adhesive portion and peeling of the surface coating during peeling are less likely to occur.

In the fourth embodiment, the formation of the pattern composed of the strong adhesive portion and the weak adhesive portion is the same as the method for forming the weak adhesive portion of the first embodiment described above. That is, for example, it can be formed by irradiating the pressure-sensitive adhesive layer 12 with energy rays from a known irradiation device via a light-shielding member having a light-shielding part made of a pattern matching the strong adhesive part.
Moreover, in order to produce the surface protection film in which the adhesive was partially applied, the non-adhesive part can be formed together with the strong adhesive part by performing screen printing or inkjet printing. By forming the pattern composed of the strong adhesive portion and the weak adhesive portion, it is possible to further suppress the peeling of the surface film.

(Fifth embodiment)
In the fourth embodiment described above, the pattern constituted by the strong adhesive portion and the weak adhesive portion is provided over the entire surface of the adhesive surface 15 (that is, both the annular region 16 and the central portion 17). It is not necessary to be provided on the entire surface, and may be provided on a part of the adhesive surface 15.
The fifth embodiment, which is one embodiment thereof, will be described below with reference to FIG.

In the fifth embodiment, as shown in FIG. 11, the pattern constituted by the strong adhesive portion and the weak adhesive portion is provided in both the outer portion 16A and the inner portion 16B of the annular region 16. On the other hand, the intermediate part 16C between the outer part 16A and the inner part 16B becomes a strong adhesive part without the adhesive layer 12 being cured by energy rays. That is, since the outer portion 16A and the inner portion 16B are regions where the strong adhesive portion and the weak adhesive portion are mixed, the adhesive strength as a region is lower than the intermediate portion 16C (strong adhesive region) made of the strong adhesive portion. It becomes the weak adhesion area.

In the present embodiment, the annular region 16 includes, in the same manner as in the first embodiment, an outer portion 16A composed of a weak adhesive region that exhibits an annular shape, and an intermediate portion 16C composed of a strong adhesive region that exhibits an annular shape, from the outside. An inner portion 16B made of a weakly adhesive region provided inside the intermediate portion 16C is provided.
Therefore, as in the first embodiment, the surface protective film 10 according to the present embodiment also prevents the adhesive residue, without peeling off the coating on the surface of the adherend or causing poor peeling, The surface protective film can be appropriately peeled from the adherend.

Furthermore, also in this embodiment, when the surface protection film 10 is affixed to the adherend having the annular portion 23 (see FIG. 2), the outer portion 16A is the outer periphery of the annular portion 23, as in the first embodiment. Since the inner portion 16B is disposed on the inner peripheral portion 23B of the annular portion 23 while being disposed on the portion 23A, the adhesive residue generated at the inner peripheral portion 23B and the outer peripheral portion 23A is the same as in the first embodiment. Can be particularly effectively prevented.
In the present embodiment, the central portion 17 is provided with a pattern composed of a strong adhesive portion and a weak adhesive portion, but it is not necessary to provide a pattern, and only the strong adhesive portion or the weak adhesive portion is provided. May be. However, the central portion 17 is configured by a pattern together with the inner portion 16B and becomes a weakly adhesive region, so that, as in the first embodiment, it adheres to a lens or a precision component provided at a position corresponding to the central portion 17. It becomes easy to prevent transfer of the agent.

In addition, when the pattern comprised by a strong adhesion part and a weak adhesion part is provided in a part of adhesion surface 15, the aspect is not limited to said 5th Embodiment, 6th and 6th demonstrated below. The aspect of 7 embodiment may be sufficient.

(Sixth embodiment)
In the sixth embodiment, as shown in FIG. 12, the pattern constituted by the strong adhesion portion and the weak adhesion portion is provided on the outer portion 16 </ b> X in the annular region 16. On the other hand, the inner portion 16Y in the annular region 16 is constituted by a strong adhesive portion without the adhesive layer 12 being cured by energy rays. That is, in this embodiment, in the annular region 16, as in the second embodiment, in order from the outside, the outer portion 16 </ b> X composed of a weak adhesive region that exhibits an annular shape, and the strong adhesive region provided inside the outer portion. An inner portion 16Y is provided.

Therefore, as in the second embodiment, the surface protective film 10 according to the present embodiment also prevents the adhesive residue, without peeling off the coating on the surface of the adherend or causing poor peeling, The surface protective film can be appropriately peeled from the adherend.
Furthermore, also in the present embodiment, as in the second embodiment, when the surface protective film 10 is affixed to the adherend having the annular portion 23, the outer portion 16 </ b> X (weakly adhesive region) is the outer periphery of the annular portion 23. By disposing on the portion 23A, it is possible to effectively prevent the adhesive residue generated on the outer peripheral portion 23A (see FIG. 4).
In addition, in this embodiment, although the center part 17 is comprised with a strong adhesion part, it does not need to be comprised with a strong adhesion part, may be comprised with a weak adhesion part, and a strong adhesion part and a weak adhesion part A pattern composed of a strong adhesive portion and a weak adhesive portion may be provided.

(Seventh embodiment)
In the seventh embodiment, as shown in FIG. 13, the pattern composed of the strong adhesive portion and the weak adhesive portion is provided in the inner portion 16 </ b> Y in the annular region 16. On the other hand, the outer portion 16X of the annular region 16 is constituted by a strong adhesive portion without the adhesive layer 12 being cured by energy rays. That is, in the present embodiment, in the annular region 16, as in the third embodiment, the outer portion 16 </ b> X consisting of a strong adhesive region that exhibits an annular shape and the weakly adhesive region provided inside the outer portion 16 </ b> X in order from the outside. An inner portion 16Y is provided.

Therefore, the surface protective film 10 according to the present embodiment is also provided with a strong adhesive portion and a weak adhesive portion in the annular region 16, so that the film on the surface of the adherend is peeled off or peeled off while preventing adhesive residue. The surface protective film 10 can be appropriately peeled from the adherend without causing defects.
Furthermore, also in this embodiment, when the surface protective film 10 is affixed to the adherend having the annular portion 23, the inner portion 16 </ b> Y (weak adhesion region) is within the annular portion 23, as in the third embodiment. By disposing on the peripheral portion 23B, it is possible to effectively prevent adhesive residue generated on the inner peripheral portion 23B (see FIG. 4).
In the present embodiment, the central portion 17 is provided with a pattern composed of a strong adhesive portion and a weak adhesive portion, similar to the inner portion 16Y. You may be comprised from the adhesion part single-piece | unit.

In the above fifth to seventh embodiments, the weak adhesive region and the strong adhesive region are provided, and the weak adhesive region has a pattern including the weak adhesive portion and the strong adhesive portion. The region may have a pattern constituted by a weak adhesive portion and a strong adhesive portion.
In this case, as in the fifth embodiment, in the case where the outer portion 16A and the inner portion 16B that are weak adhesion regions and the intermediate portion 16C that is a strong adhesion region are provided, for example, as shown in FIG. The outer portion 16A and the inner portion 16B are made of a weak adhesive portion, and the intermediate portion 16C is made of a pattern made up of a weak adhesive portion and a strong adhesive portion.

Further, as in the sixth embodiment, when the outer portion 16X and the inner portion 16Y are provided in the annular region 16 (see FIG. 12), the outer portion 16X is a weak adhesion region, and the inner portion 16Y is a strong adhesion region. For example, the outer portion 16X is formed of a weak adhesive portion, and the inner portion 16Y is formed of a pattern formed of a weak adhesive portion and a strong adhesive portion. Similarly, as in the seventh embodiment, the outer portion 16X and the inner portion 16Y are provided in the annular region 16 (see FIG. 13), and the outer portion 16X is a strong adhesion region and the inner portion 16Y is a weak adhesion region. For example, the outer portion 16X is composed of a pattern composed of a weak adhesive portion and a strong adhesive portion, and the inner portion 16Y is composed of a weak adhesive portion.

In addition, in the fifth to seventh embodiments shown in FIGS. 11 to 14, the pattern composed of the weakly-adhesive portion and the strong-adhesive portion is alternately arranged with the linear weak-adhesive portion and the linear strong-adhesive portion. However, the pattern is not limited to the stripe shape, and may have any of the pattern shapes shown in the fourth embodiment.

In the specific description of the first to seventh embodiments, the energy beam curable pressure sensitive adhesive is partially cured using the energy beam curable pressure sensitive adhesive, so that the weak adhesive portion and the strong adhesive portion are used. However, the present invention is not limited to this embodiment.
For example, the pressure-sensitive adhesive may be a non-energy ray curable pressure-sensitive adhesive, and the surface protection film 10 may be partially provided with the pressure-sensitive adhesive layer 12. Of course, the pressure sensitive adhesive may be an energy ray curable pressure sensitive adhesive, and the surface protective film 10 may be partially provided with the pressure sensitive adhesive layer 12.
When the pressure-sensitive adhesive layer 12 is partially provided, the adhesive surface 15 is provided with a non-adhesive part. However, in each embodiment described above, a part that is a weak adhesive part is a non-adhesive part. In the first to third embodiments, the weakly adhesive region in each of the embodiments is a non-adhesive region that is a region having no adhesive force. In the fifth to seventh embodiments, the weakly adhesive region is It becomes a weak adhesion area | region by the pattern comprised by the non-adhesion part.

Further, in each pattern described in the fourth to seventh embodiments, the pattern pitch (that is, the interval between adjacent strong adhesive portions, or between adjacent weak adhesive portions or non-adhesive portions). The interval) is preferably 10 to 500 μm, more preferably 10 to 300 μm, and particularly preferably 10 to 250 μm.
That is, the width of each stripe, the width of each wavy line and the interval between wavy lines, the width of each line forming a lattice, the interval between adjacent lines constituting the lattice, the interval between dots, and the width of dots The height, or the height and width of each square constituting the checkered pattern is preferably 10 to 500 μm, more preferably 10 to 300 μm, and particularly preferably 10 to 250 μm.

Further, when the entire adhesive surface 15 has a pattern as in the fourth embodiment (see FIGS. 5 to 10), the area occupied by the weakly adhesive portion or the non-adhesive portion with respect to the entire adhesive surface 15 is 3 to 70%. It is preferably 3 to 60%, more preferably 3 to 50%.
Further, as in the fifth to seventh embodiments, when a pattern is provided in a part of the adhesive surface 15 (for example, a weak adhesive region) (see FIGS. 11 to 13), the region (weak adhesive region) Similarly, the area occupied by the weakly or non-adhesive part is preferably 3 to 70%, more preferably 3 to 60%, and particularly preferably 3 to 50%. Similarly, when a pattern is provided in the strong adhesion region (see, for example, FIG. 14), the area occupied by the weak adhesion portion or the non-adhesion portion with respect to the strong adhesion region is also preferably 3 to 70%. 60% is more preferable, and 3 to 50% is particularly preferable.

Furthermore, in the first to seventh embodiments, the weak adhesive portion is formed by being cured by energy ray irradiation, and the portion where the energy ray is not irradiated becomes the strong adhesive portion. A weak adhesion part and a strong adhesion part may be formed by a technique. For example, by irradiating and curing an energy ray on both the weakly-adhesive part and the strong-adhesive part, the amount of energy rays applied to the weakly-adhesive part is made larger than the amount of energy rays applied to the strongly-adhesive part. The curing rate of the weak adhesive part may be higher than that of the strong adhesive part to form the strong adhesive part and the weak adhesive part.
Further, in the first to seventh embodiments, the portion cured with the energy beam is a weakly adhesive portion having an adhesive force so that it can adhere to the adherend, but is cured with the energy beam. In this way, the adhesive strength may be completely lost and a non-adhesive portion may be formed.

In each of the above embodiments, when the pressure sensitive adhesive is an energy ray curable pressure sensitive adhesive, the surface protective film is irradiated again with energy rays when it is peeled off, and the pressure sensitive adhesive in the strong adhesive portion is cured. It is also possible to make the rest less likely to occur.

Further, the strong adhesive part and the weak adhesive part or the non-adhesive part may be formed by using different materials for the adhesive. Furthermore, you may form a weak adhesion part or a non-adhesion part by what is called paste killing. That is, a material having a low adhesive strength such as a release agent or a material having no adhesive strength is partially applied on the adhesive layer to make the portion a weakly adhesive portion or a non-adhesive portion, and the remaining portion. It is good also as a strong adhesion part.

Furthermore, in the above description, the surface protection film is shown with one of the weakly adhesive part or the non-adhesive part, but both the weakly adhesive part and the non-adhesive part may be provided in a mixed manner. For example, by partially applying an adhesive to the adhesive surface 15 and forming a portion where the adhesive is not provided (non-adhesive portion), only a part of the adhesive layer is cured with energy rays, thereby weakening An adhesive part may be formed. In that case, in the surface protection film, for example, in each aspect shown in the first to seventh embodiments, a part of the weak adhesive portion is a non-adhesive portion.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

In this example, the surface protective film was evaluated by the following method.
[Adhesive residue evaluation]
A surface protective film was affixed to an annular flat polycarbonate plate having an outer diameter of 3.75 mm and an inner diameter of 2.37 mm so that the respective centers substantially coincided, and then heated at 80 ° C. for 5 hours. Thereafter, the sample was returned to room temperature, and the surface protective film was irradiated with ultraviolet rays under irradiation conditions of illuminance of 230 mW / cm ² and light amount of 350 mW / cm ² , and then the film edge was grasped with tweezers and peeled at a peeling angle of 180 °. The adhesive remaining on the adherend after peeling was confirmed with an optical microscope (manufactured by Keyence Corporation, trade name “VHX-200”).
A: The area where the pressure-sensitive adhesive remains in the area of the adherend surface is less than 5%.
B: Of the area of the adherend surface, the area where the adhesive remains is 5% or more and less than 15%.
D: Of the area of the adherend surface, the area where the adhesive remains is 15% or more.

[Slip evaluation]
Using a 2 kg rubber roller, a surface protection film having a width of 25 mm and a length of 150 mm was attached to a test plate (SUS304 steel plate) with one press-fitting so that the adhesive layer was in contact with an area of 25 mm × 25 mm. JISZ0237: Evaluation was performed according to a 2000 holding power test.
A: Hold for 70000 seconds or more, and deviation of less than 1 mm occurred.
B: Although held for 70000 seconds, a deviation of 1 mm or more occurred.
C: Although held for 70000 seconds, a deviation of 3 mm or more occurred.
D: The sample fell before 70000 seconds passed.

[Evaluation of film peeling]
A polycarbonate plate having an annular flat plate shape with an outer diameter of 3.75 mm and an inner diameter of 2.37 mm and having titanium oxide coated on the surface was prepared as an adherend. A surface protective film was affixed to the surface of the adherend so that the centers of the adherends substantially coincided, and then heated at 80 ° C. for 5 hours. Thereafter, the sample was returned to room temperature, and the surface protective film was irradiated with ultraviolet rays under irradiation conditions of illuminance of 230 mW / cm ² and light amount of 350 mW / cm ² , and then the film edge was grasped with tweezers and peeled at a peeling angle of 180 °. . The peeling of the thin film on the adherend after peeling was confirmed with an optical microscope (manufactured by Keyence Corporation, trade name “VHX-200”) and evaluated according to the following evaluation criteria.
1: The area where the film was peeled out of the area of the adherend surface was less than 5%.
2: The area where the film was peeled out of the surface area of the adherend was 5% or more and less than 10%.
3: The area where the film was peeled out of the area of the adherend surface was 10% or more and less than 25%.
4: The area where the film peeled out of the area of the adherend surface is 25% or more and less than 50%.
5: The area where the film is peeled is 50% or more of the area of the adherend surface.

In each of Examples and Comparative Examples, an adhesive composed of the following blends A and B was used as an adhesive.

* Each value in Table 1 indicates parts by mass.
* The components shown in Table 1 are as follows.
Acrylic resin: Acrylic resin obtained by copolymerizing butyl acrylate (BA), methyl methacrylate (MMA) and 2-hydroxyethyl acrylate (HEA) at a mass ratio of 65/20/15 (BA / MMA / HEA) A filler obtained by adding 2-isocyanatoethyl methacrylate (MOI) to 80 mol% of 2-hydroxyethyl acrylate in the filler. Silica filler (trade name “YA050C-MJE” manufactured by Admatechs Co., Ltd., average particle (Diameter: 50 nm)
Cross-linking agent: Tolylene diisocyanate-based cross-linking agent (trade name “Coronate L” manufactured by Tosoh Corporation)
Photopolymerization initiator: diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (manufactured by BASF, trade name “Darocur TPO”)

[Example 1]
A 38 μm thick polyethylene terephthalate (PET) release sheet (product name “SP PET381031”, manufactured by Lintec Corporation) was coated with the adhesive of Formulation A, dried at 100 ° C. for 1 minute, and a thickness of 10 μm. Then, a base material made of a PET film (thickness: 50 μm, manufactured by Toyobo Co., Ltd., trade name “A4100”) was bonded to the adhesive layer. Then, it left still for 7 days in 23 degreeC and 50% RH environment. Then, the base material side of the sheet produced, place the light shielding filter, a UV irradiation apparatus (made by LINTEC Corporation, trade name "RAD-2000m / 12"), illuminance 230 mW / cm ^2, the irradiation amount of light 350 mW / cm ² The pressure-sensitive adhesive layer was cured by irradiating ultraviolet rays under the conditions, and then the obtained sheet was punched out to obtain a circular surface protective film having a diameter of 5 mm, and the adhesive residue and film peeling were evaluated.
The light-shielding filter is a weak adhesive part in which the outer part 16X is not hardened with energy rays but is made to be a strong adhesive part (strong adhesive area) and the inner part 16Y is hardened with energy rays, like the surface protection film shown in FIG. The light was shielded to be (weakly adhesive region). The outer diameter / 2 (W3) of the inner portion 16Y was 1.42 mm.
Moreover, the produced sheet was cut into a size of 25 mm in width and 150 mm in length, and the deviation was evaluated using a sample for evaluation. However, the sample for deviation evaluation was prepared so that the entire part to be adhered to the test plate was a strong adhesion region, that is, a strong adhesion part (uncured part).

[Example 2]
The light shielding portion of the light shielding filter is changed, and the outer portion 16X becomes a weak adhesive portion cured with energy rays and the inner portion 16Y becomes a strong adhesive portion without being cured with energy rays, as in the surface protection film shown in FIG. The same procedure as in Example 1 was performed except for the points described above. The outer diameter / 2 (W3) of the inner portion 16Y was 1.42 mm.

[Example 3]
The light-shielding part of the light-shielding filter is changed, and the outer part 16A and the inner part 16B are cured with energy rays to form a weak adhesive portion, and the intermediate part 16C is not cured with energy rays, as in the surface protective film shown in FIG. The procedure was the same as in Example 1 except that the strongly adhesive part was used. The outer diameter / 2 (W1) of the intermediate portion 16C was 1.65 mm, and the outer diameter / 2 (W2) of the inner portion 16B was 1.42 mm.

[Example 4]
The same procedure as in Example 1 was performed except that the formulation of the pressure-sensitive adhesive to be used was changed to the formulation B.

[Example 5]
The light-shielding part of the light-shielding filter is changed, and the entire outer part 16A and inner part 16B are cured with energy rays as shown in the surface protective film shown in FIG. ), And a strong adhesive region consisting of a circular dot-shaped weakly adhesive part (cured part) and a strong adhesive part (an uncured part other than dots) was the same as in Example 1. . The outer diameter / 2 (W1) of the intermediate portion 16C was 1.65 mm, and the outer diameter / 2 (W2) of the inner portion 16B was 1.42 mm. Further, the weak adhesive portion was 10% of the entire strong adhesive region, and the strong adhesive portion was 90%.
In addition, in the sample for deviation evaluation, the entire sticking part with the test plate becomes a strong adhesion region, that is, a circular dot-shaped weakly adhesive part (cured part) and a strong adhesive part (uncured other than dots) Part).

[Example 6]
The same procedure as in Example 5 was performed except that the light-shielding part of the light-shielding filter was changed so that in the strong adhesive region, the weak adhesive part was 20% of the entire strong adhesive region and the strong adhesive part was 80%. .

[Example 7]
The same procedure as in Example 5 was performed, except that the light-shielding part of the light-shielding filter was changed so that the weak adhesive region was 50% of the entire strong adhesive region and the strong adhesive region was 50% in the strong adhesive region. .

[Comparative Example 1]
It carried out like Example 1 except the point which did not harden an adhesive layer.

As is clear from the results in Table 2, in Examples 1 to 7, the holding force of the pressure-sensitive adhesive layer is improved by using at least a part of the annular region as a strong adhesive part and the remaining part as a weak adhesive part. While maintaining, it was possible to prevent adhesive residue when the surface protective film was peeled off and peeling of the coating on the adherend. Further, peeling of the film on the adherend could be more effectively prevented by forming a part of the adhesive surface as a pattern composed of a weak adhesive part and a strong adhesive part as in Examples 5 to 7.
On the other hand, in Comparative Example 1, since the strong adhesive portion and the weak adhesive portion were not provided in the annular region, adhesive residue and film peeling occurred when the surface protective film was peeled off, and the protective film for the optical member and the electronic member The performance was not satisfactory.

DESCRIPTION OF SYMBOLS 10 Surface protective film 11 Base material 12 Adhesive layer 15 Adhesive surface (adhesive layer side surface)
16 annular region 16A, 16X outer part 16B, 16Y inner part 16C intermediate part 17 central part 20 optical member 21 lens 22 lens holding member 23 annular part

Claims (12)

1. A surface protective film that is applied to an optical member or an electronic member and used to protect the surface thereof,
   A substrate and a pressure-sensitive adhesive layer provided on one surface of the substrate;
   The surface of the surface protective film on the pressure-sensitive adhesive layer side is at least in the annular region surrounding the central part, and a part thereof is a strong adhesive part, and the other part is a weak adhesive part whose adhesive strength is lower than that of the strong adhesive part And a surface protective film which is at least one of a non-adhesive part.
2. The surface protection according to claim 1, wherein the pressure-sensitive adhesive layer is made of an energy ray-curable pressure-sensitive adhesive, and at least one of the weakly-adhesive portion and the non-adhesive portion is constituted by a portion cured by irradiation with energy rays. the film.
3. The surface according to claim 1 or 2, wherein the pressure-sensitive adhesive layer is partially provided on one surface of the base material, and a portion where the pressure-sensitive adhesive layer is not provided is the non-adhesive portion. Protective film.
4. The surface on the pressure-sensitive adhesive layer side of the surface protective film has a pattern shape in which at least one of the weakly-adhesive portion and the non-adhesive portion and the strong-adhesive portion are alternately provided in at least the annular region. 4. The surface protective film according to any one of 3 above.
5. In at least the annular region of the surface of the surface protective film on the pressure-sensitive adhesive layer side, at least one of the weakly-adhesive part and the non-adhesive part and the strong-adhesive part have a plurality of stripe shapes, lattice shapes, dot shapes, and wavy lines. The surface protective film according to any one of claims 1 to 4, wherein the surface protective film is arranged in any pattern selected from a lined shape, a checkered pattern, and a shape in which a plurality of various patterns are lined up.
6. Both the outer part and the inner part in the annular region are provided with at least one of the weak adhesive part and the non-adhesive part to be a weak adhesive area or a non-adhesive area, and an intermediate part between the outer part and the inner part 6. The surface protective film according to claim 1, wherein the strong adhesive portion is provided to form a strong adhesive region.
7. One of the outer part and the inner part in the annular region is provided with the strong adhesive portion to become a strong adhesive region, and the other is provided with at least one of the weak adhesive portion and the non-adhesive portion, and is weak. The surface protective film according to any one of claims 1 to 5, which is an adhesive region or a non-adhesive region.
8. The surface protective film according to claim 6 or 7, wherein the weak adhesive region has a pattern shape in which at least one of the weak adhesive portion and the non-adhesive portion and a strong adhesive portion are alternately provided.
9. The surface protection film according to claim 6 or 7, wherein the strong adhesion region has a pattern shape in which at least one of the weak adhesion part and the non-adhesion part and the strong adhesion part are alternately provided.
10. The optical member or electronic member has an annular portion,
    The surface protective film according to any one of claims 1 to 9, wherein the annular region of the surface protective film is bonded to the annular portion.
11. A member with a surface protective film, comprising: a member selected from either an optical member or an electronic member; and the surface protective film according to any one of claims 1 to 10 attached to a surface of the member.
12. A method for protecting the surface of the optical member or electronic member by applying the surface protective film according to any one of claims 1 to 10 to the surface of the optical member or electronic member.

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