WO2019130741A1

WO2019130741A1 - Surface-protective sheet for optical member

Info

Publication number: WO2019130741A1
Application number: PCT/JP2018/038579
Authority: WO
Inventors: ▲高▼橋　智一; 元気越智
Original assignee: 日東電工株式会社
Priority date: 2017-12-26
Filing date: 2018-10-17
Publication date: 2019-07-04

Abstract

Provided is a surface-protective sheet for optical members which is able to exhibit strong tackiness, has excellent easy-release properties, can sufficiently exhibit residual adhesive force, and can exhibit satisfactory applicability even with a low application pressure. The surface-protective sheet for optical members of the present invention comprises a base film and a pressure-sensitive adhesive layer disposed as at least one of the outermost layers, and decreases in adhesive force upon irradiation with actinic rays.

Description

Optical protection sheet

The present invention relates to a surface protection sheet for an optical member.

The surface protecting sheet for an optical member is attached, for example, for surface protection of the optical member (for example, a display member) before being subjected to various processes (typically, at least one of manufacturing processes), The optical member is peeled off at any appropriate time when the need for the surface protection is eliminated (e.g., Patent Document 1). When such a surface protection sheet for an optical member is peeled off, the optical member may be deformed or the optical member may be broken, which causes a problem of decreasing the yield. In order not to cause such a problem, attempts have been made to use a surface protective sheet for optical members having low adhesion. However, since such an optical member surface protective sheet has low adhesive strength, it may be unexpectedly peeled off in various processes, resulting in a problem that the surface protective ability is lowered. That is, there arises a problem that light releasability and strong adhesiveness can not be simultaneously achieved.

The optical member after peeling the surface protection sheet for an optical member is adhered to a member such as glass via an adhesive or an adhesive. However, when light surface removability is high when peeling the surface protection sheet for optical members from an optical member, it originates in the component of the adhesive layer of the surface protection sheet for optical members from the surface protection sheet for optical members to the surface of optical members. Substances may be transferred, and the type and amount of such substances may cause a problem of reduced adhesion to a member such as glass (reduction in residual adhesion). That is, there arises a problem that light releasability and sufficient residual adhesion can not be simultaneously achieved.

In order to prevent destruction of the optical member in various processes, it is preferable that the application pressure to the optical member in the various processes is small. The same applies to the attachment of the surface protection sheet for an optical member, and it is preferable to attach the surface protection sheet for an optical member to the optical member with a small attachment pressure. However, when the surface protection sheet for an optical member is attached to the optical member with a small attachment pressure, there arises a problem that a partial attachment failure such as formation of air bubbles occurs. That is, there arises a problem that it is not possible to achieve both a low sticking pressure and a good sticking property.

When the adhesion tension of the surface protective sheet for an optical member is large when the surface protective sheet for an optical member is attached to the optical member due to the recent thinning of the optical member, the surface protective sheet for the optical member and the integral product of the optical member It is necessary to affix the surface protection sheet for the optical member to the optical member with a small adhesion tension because a problem arises that the warpage becomes large, but in this case, air bubbles are formed as in the case of affixing with a low adhesion pressure There is a problem that partial sticking failure such as That is, there arises a problem that good stickability can not be expressed.

JP 2012-224805 A

The object of the present invention is to provide a surface protection sheet for an optical member which can express strong adhesiveness, is excellent in light releasability, can sufficiently exhibit residual adhesive power, and can exhibit good adhesion even with low application pressure. It is to do.

The surface protective sheet for optical members of the present invention is
It is a surface protection sheet for optical members which has a substrate film and an adhesive layer provided on at least one of the outermost layers,
The adhesion is reduced by irradiation with active energy rays.

In one embodiment,
The adhesive force (A) of the surface protection sheet for optical members is 32 mN / 10 mm or more,
The adhesive force (B) after ultraviolet irradiation of the surface protection sheet for an optical member is 24 mN / 10 mm or less,
The adhesion (A) is at least twice the adhesion (B) after the ultraviolet irradiation,
The adhesive force (C) after low pressure adhesion of the surface protective sheet for an optical member is 0.8 times or more of the adhesive force (A),
The residual adhesive force (D) after ultraviolet irradiation of the surface protective sheet for an optical member is 0.8 times or more of the initial residual adhesive force (E).
However, the measurement method of adhesive strength (A), adhesive strength after ultraviolet irradiation (B), adhesive strength after low pressure sticking (C), residual adhesion after ultraviolet irradiation (D), initial residual adhesion (E) is as follows It is street.
Adhesive force (A): Measurement is performed according to JIS Z0237: 2009 in an environment of temperature 23 ± 1 ° C. and humidity 50 ± 5% RH. The test plate is a SUS304BA plate, and the washing solvent for the test plate uses methyl ethyl ketone. The measurement of the peel adhesion strength in Section 10.4 of JIS Z0237: 2009 is carried out according to Method 1 in Section 10.4.1 of JIS Z0237: 2009.
Adhesiveness after ultraviolet irradiation (B): Measurement is carried out according to JIS Z0237: 2009 in an environment of temperature 23 ± 1 ° C. and humidity 50 ± 5% RH. However, ultraviolet light irradiation (high pressure mercury lamp, 200 mW / cm ² , 440 mJ / cm ² ) is performed within 1 minute after sticking the surface protection sheet for optical members to the test plate, and peeling within 10 minutes after the ultraviolet light irradiation Measure the adhesion. The test plate is a SUS304BA plate, and the washing solvent for the test plate uses methyl ethyl ketone. The measurement of the peel adhesion strength in Section 10.4 of JIS Z0237: 2009 is carried out according to Method 1 in Section 10.4.1 of JIS Z0237: 2009.
Adhesive force after low pressure adhesion (C): Measured according to JIS Z0237: 2009 in an environment of temperature 23 ± 1 ° C. and humidity 50 ± 5% RH. However, instead of using a 2 kg pressure roller, a 200 g pressure roller is used, and instead of performing pressure bonding with a pressure roller by a total of 2 reciprocations at a speed of 10 ± 0.5 mm / s, one direction is performed at 100 ± 5 mm / s. Crimp only once and measure adhesion. The test plate is a SUS304BA plate, and the washing solvent for the test plate uses methyl ethyl ketone. The measurement of the peel adhesion strength in Section 10.4 of JIS Z0237: 2009 is carried out according to Method 1 in Section 10.4.1 of JIS Z0237: 2009.
Residual adhesion after ultraviolet irradiation (D): First, in an environment at a temperature of 23 ± 1 ° C. and a humidity of 50 ± 5% RH, a test of the surface protection sheet for optical members according to the method of measuring the adhesion after ultraviolet irradiation (B) Peel off the board. However, peeling from the test plate of the surface protection sheet for optical members is performed one day after it is attached. Next, in a environment with a temperature of 23 ± 1 ° C and a humidity of 50 ± 5% RH, pull the adhesive tape (product name: No. 31B made by Nitto Denko Corporation) and cut the surface protection sheet for optical members. It is stuck on the surface of the peeled test plate and left for 30 minutes, and peeled off at a peeling angle of 180 ° and a peeling speed of 300 ± 12 mm / min, and the residual adhesive strength (D) after ultraviolet irradiation is measured.
Initial residual adhesion (E): A pressure-sensitive adhesive tape (product name: No. 31B, manufactured by Nitto Denko Corporation, product name: No. 31B) cut to a width of 19 mm in an environment of temperature 23 ± 1 ° C. and humidity 50 ± 5% RH After sticking to the surface and leaving for 30 minutes, peel at a peel angle of 180 ° and a peel speed of 300 ± 12 mm / min, and measure the initial residual adhesion (E).

In one embodiment, the pressure-sensitive adhesive layer contains a photopolymerization initiator that generates a radical upon irradiation with ultraviolet light.

In one embodiment, 30% by weight or more of the pressure-sensitive adhesive layer is a polyurethane resin.

In one embodiment, the pressure-sensitive adhesive layer contains a polymerizable carbon-carbon double bond.

In one embodiment, the polymerizable carbon-carbon double bond is a polymerizable carbon-carbon double bond that at least one group selected from an acryloyl group and a methacryloyl group has.

In one embodiment, the pressure-sensitive adhesive layer contains a compound having a polymerizable carbon-carbon double bond.

In one embodiment, the pressure-sensitive adhesive layer contains a polyurethane resin, a compound having a bifunctional or higher polymerizable carbon-carbon double bond, and an isocyanate-based crosslinking agent.

In one embodiment, the compound having a polymerizable carbon-carbon double bond is a polyol having a polymerizable carbon-carbon double bond.

In one embodiment, the polyurethane-based resin is obtained by polymerizing a monomer composition containing a polyisocyanate and a monomer having at least two functional groups capable of reacting with isocyanate groups, and the polyisocyanate and the isocyanate groups At least one selected from the above monomers having at least two functional groups capable of reacting has a polymerizable carbon-carbon double bond.

In one embodiment, the monomer having at least two functional groups capable of reacting with the isocyanate group is a polyol having a bifunctional or higher functional polymerizable carbon-carbon double bond.

According to the present invention, it is possible to provide a surface protection sheet for an optical member which can express strong adhesiveness, is excellent in light releasability, can sufficiently exhibit residual adhesive power, and can exhibit good sticking properties even if the sticking pressure is low. can do.

It is a schematic sectional drawing of the surface protection sheet for optical members by one embodiment of this invention. It is a schematic sectional drawing of the surface protection sheet for optical members by another one embodiment of this invention.

<< A. Surface protection sheet for optical members >>
The surface protection sheet for optical members of the present invention has a substrate film and a pressure-sensitive adhesive layer provided on at least one of the outermost layers. The surface protection sheet for an optical member of the present invention has any appropriate other layer as long as the effects of the present invention are not impaired as long as it has a base film and an adhesive layer provided on at least one of the outermost layers. May be included.

FIG. 1 is a schematic cross-sectional view of a surface protective sheet for an optical member according to one embodiment of the present invention. In FIG. 1, the surface protection sheet 100 for optical members has the base film 10 and the adhesive layer 20a with which the one side of this base film was equipped.

FIG. 2 is a schematic cross-sectional view of an optical member surface protective sheet according to another embodiment of the present invention. In FIG. 2, the surface protection sheet 100 for optical members is provided on the base film 10, the pressure-sensitive adhesive layer 20a provided on one side of the base film, and the other side of the base film. And an adhesive layer 20b.

The surface of the pressure-sensitive adhesive layer opposite to the base material layer may be provided with any suitable release liner as long as the effects of the present invention are not impaired for protection before use. As the release liner, for example, the surface of a substrate (liner substrate) such as paper or plastic film is treated with silicone, the surface of the substrate (liner substrate) such as paper or plastic film is made of a polyolefin resin And laminated release liners. Examples of plastic films as liner substrates include polyethylene films, polypropylene films, polybutene films, polybutadiene films, polymethylpentene films, polyvinyl chloride films, vinyl chloride copolymer films, polyethylene terephthalate films, polybutylene terephthalate films, Polyurethane films, ethylene-vinyl acetate copolymer films and the like can be mentioned. The plastic film as the liner substrate is preferably a polyethylene film or a polyethylene terephthalate film.

The thickness of the release liner is preferably 1 μm to 500 μm, more preferably 3 μm to 450 μm, still more preferably 5 μm to 400 μm, and particularly preferably 10 μm to 300 μm.

Any appropriate thickness can be adopted as the thickness of the surface protective sheet for an optical member of the present invention as long as the effects of the present invention are not impaired. The thickness of the surface protection sheet for an optical member of the present invention is preferably 5 μm to 500 μm, more preferably 10 μm to 400 μm, and still more preferably 20 μm to 300 μm, in that the effects of the present invention can be further developed. And particularly preferably 30 μm to 200 μm. When the thickness of the surface protection sheet for an optical member of the present invention is less than 5 μm, it is difficult to maintain the shape of the sheet, and there is a risk that adhesion defects such as generation of unadhered air bubbles may occur. . When the thickness of the surface protective sheet for an optical member of the present invention exceeds 500 μm, a large force is required to bend the sheet during peeling, and a large stress may be applied to the adherend, which may cause the adherend to break.

In the surface protection sheet for an optical member of the present invention, the adhesion of the pressure-sensitive adhesive layer is reduced by irradiation with active energy rays.

Examples of the active energy ray include light rays such as far ultraviolet rays, ultraviolet rays, near ultraviolet rays, infrared rays and the like; electromagnetic waves such as X rays and γ rays; electron rays; proton rays; neutron rays; In the present invention, ultraviolet light is preferred in that the effects of the present invention can be further developed.

In the case of irradiating the surface protection sheet for an optical member of the present invention with active energy rays, any suitable irradiation direction can be adopted as long as the effect of the present invention is not impaired. As such an irradiation direction, the incident angle with respect to the sheet surface of the surface protection sheet for optical members of the present invention is preferably more than 0 ° and not more than 90 °, and more preferably 30 ° to 90 °. Preferably, it is 45 ° to 90 °, and particularly preferably 60 ° to 90 °.

The adhesive strength (A) of the surface protection sheet for optical members of the present invention is 32 mN / 10 mm or more, preferably 35 mN / 10 mm or more, more preferably 40 mN / 10 mm or more, and still more preferably 45 mN / 10 mm or more And particularly preferably 50 mN / 10 mm or more. The upper limit of the adhesive force (A) of the surface protective sheet for an optical member of the present invention may have any appropriate upper limit as long as the effects of the present invention are not impaired. As an upper limit of the adhesive force (A) of such a surface protection sheet for optical members of this invention, it is 1000 mN / 10 mm or less, for example. When the adhesive strength (A) of the surface protective sheet for an optical member of the present invention is 32 mN / 10 mm or more, the surface protective sheet for an optical member can exhibit strong adhesiveness. When the adhesive force (A) of the surface protection sheet for optical members of the present invention is less than 32 mN / 10 mm, there is a possibility that the surface protection sheet for optical members can not express strong adhesiveness.

The adhesive strength (A) is measured in accordance with JIS Z0237: 2009 in an environment at a temperature of 23 ± 1 ° C. and a humidity of 50 ± 5% RH. The test plate is a SUS304BA plate, and the washing solvent for the test plate uses methyl ethyl ketone. The measurement of the peel adhesion strength in Section 10.4 of JIS Z0237: 2009 is carried out according to Method 1 in Section 10.4.1 of JIS Z0237: 2009. More details will be described later in the section of Examples.

The adhesive force (B) after ultraviolet irradiation of the surface protection sheet for an optical member of the present invention is 24 mN / 10 mm or less, preferably 23.5 mN / 10 mm or less, more preferably 23 mN / 10 mm or less, still more preferably It is 22.5 mN / 10 mm or less, and particularly preferably 22 mN / 10 mm or less. The lower limit of the adhesive strength (B) after ultraviolet irradiation of the surface protective sheet for an optical member of the present invention may have any appropriate lower limit as long as the effects of the present invention are not impaired. The lower limit of the adhesive strength (B) after ultraviolet irradiation of the surface protective sheet for optical members of the present invention is, for example, 1 mN / 10 mm or more. If the adhesive force (B) after ultraviolet irradiation of the surface protection sheet for an optical member of the present invention is 24 mN / 10 mm or less, the surface protection sheet for an optical member can exhibit excellent light peelability by ultraviolet irradiation. When the adhesive force (B) after ultraviolet irradiation of the surface protection sheet for an optical member of the present invention exceeds 24 mN / 10 mm, the surface protection sheet for an optical member may be inferior in light releasability even when ultraviolet irradiation is performed.

The adhesion after ultraviolet irradiation (B) is measured according to JIS Z0237: 2009 in an environment of temperature 23 ± 1 ° C. and humidity 50 ± 5% RH. However, ultraviolet light irradiation (high pressure mercury lamp, 200 mW / cm ² , 440 mJ / cm ² ) is performed within 1 minute after sticking the surface protection sheet for optical members to the test plate, and peeling within 10 minutes after the ultraviolet light irradiation Measure the adhesion. The test plate is a SUS304BA plate, and the washing solvent for the test plate uses methyl ethyl ketone. The measurement of the peel adhesion strength in Section 10.4 of JIS Z0237: 2009 is carried out according to Method 1 in Section 10.4.1 of JIS Z0237: 2009. More details will be described later in the section of Examples.

The adhesive strength (A) is at least twice, preferably at least 2.05 times, more preferably at least 2.1 times, still more preferably at least 2.15 times the adhesive strength (B) after ultraviolet irradiation. Particularly preferably, it is 2.2 times or more. The upper limit may be any appropriate upper limit as long as the effects of the present invention are not impaired. Such an upper limit is, for example, not more than 40 times the adhesion (A) after irradiation with ultraviolet light (B). If the adhesive force (A) is twice or more the adhesive force (B) after irradiation with ultraviolet rays, the surface protective sheet for optical members is irradiated with ultraviolet rays before peeling of the surface protective sheet for optical members, for optical members The surface protective sheet can achieve both of the strong adhesiveness and the light releasability well. When the adhesion (A) is less than twice the adhesion (B) after irradiation with ultraviolet light, the surface for optical members is irradiated with ultraviolet light before the surface protection sheet for optical members is peeled off. There is a possibility that a protective sheet can not be compatible in strong adhesiveness and light releasability.

The adhesion (C) after low pressure adhesion of the surface protection sheet for optical members of the present invention is 0.8 times or more of the adhesion (A), preferably 0.85 or more, more preferably 0.9. It is more than double, more preferably more than 0.95, particularly preferably more than 0.96. The upper limit may be any appropriate upper limit as long as the effects of the present invention are not impaired. Such an upper limit is typically 1.00 times. The surface protection sheet for optical members according to the present invention is good even if the adhesion pressure is low, provided that the adhesion (C) after low pressure adhesion of the surface protection sheet for optical members of the present invention is 0.8 times or more of the adhesion (A) It is possible to express good patchability. The surface protection sheet for optical members according to the present invention has good adhesion when the adhesion pressure is low, if the adhesion (C) after low pressure adhesion is less than 0.8 times the adhesion (A) There is a possibility that it can not express sex.

The adhesion after low pressure adhesion (C) is measured according to JIS Z0237: 2009 in an environment of temperature 23 ± 1 ° C. and humidity 50 ± 5% RH. However, instead of using a 2 kg pressure roller, a 200 g pressure roller is used, and instead of performing pressure bonding with a pressure roller by a total of 2 reciprocations at a speed of 10 ± 0.5 mm / s, one direction is performed at 100 ± 5 mm / s. Crimp only once and measure adhesion. The test plate is a SUS304BA plate, and the washing solvent for the test plate uses methyl ethyl ketone. The measurement of the peel adhesion strength in Section 10.4 of JIS Z0237: 2009 is carried out according to Method 1 in Section 10.4.1 of JIS Z0237: 2009. More details will be described later in the section of Examples.

The residual adhesive strength (D) after ultraviolet irradiation of the surface protection sheet for an optical member of the present invention is 0.8 times or more, preferably 0.82 or more times of the initial residual adhesive strength (E), more preferably 0 It is not less than .84 times, more preferably not less than 0.86 times, and particularly preferably not less than 0.9 times. The upper limit may be any appropriate upper limit as long as the effects of the present invention are not impaired. Such an upper limit is typically 1.00 times. If the residual adhesive force (D) after ultraviolet irradiation of the surface protection sheet for an optical member of the present invention is 0.8 times or more of the initial residual adhesive force (E), the optical member before peeling the surface protective sheet for an optical member By irradiating the surface protection sheet with ultraviolet light, the surface protection sheet for optical members can sufficiently exhibit residual adhesive strength. When the residual adhesive strength (D) after ultraviolet irradiation of the surface protection sheet for an optical member of the present invention is less than 0.8 times the initial residual adhesive strength (E), before the peeling of the surface protective sheet for an optical member Even when the surface protection sheet is irradiated with ultraviolet light, the surface protection sheet for optical members may not be able to sufficiently express the residual adhesive force.

The residual adhesive strength (D) after irradiation with ultraviolet light is first of all according to the method for measuring the adhesive strength (B) after irradiation with ultraviolet light in an environment of temperature 23 ± 1 ° C. and humidity 50 ± 5% RH. Peel off the test plate. However, peeling from the test plate of the surface protection sheet for optical members is performed one day after it is attached. Next, in a environment with a temperature of 23 ± 1 ° C and a humidity of 50 ± 5% RH, pull the adhesive tape (product name: No. 31B made by Nitto Denko Corporation) and cut the surface protection sheet for optical members. It is stuck on the surface of the peeled test plate and left for 30 minutes, and peeled off at a peeling angle of 180 ° and a peeling speed of 300 ± 12 mm / min, and the residual adhesive strength (D) after ultraviolet irradiation is measured. More details will be described later in the section of Examples.

The residual adhesive force (E) before ultraviolet irradiation is a pressure-sensitive adhesive tape (product name: No. 31B, manufactured by Nitto Denko Corporation) cut into a width of 19 mm in an environment of temperature 23 ± 1 ° C. and humidity 50 ± 5% RH. It affixes on the surface of a test plate, and after leaving it to stand for 30 minutes, it exfoliates with exfoliation angle 180 degrees, peel speed 300 ± 12 mm / min, and measures initial remaining adhesive power (E). More details will be described later in the section of Examples.

<A-1. Substrate film>
The base film may be only one layer or two or more layers. The substrate film may be stretched.

The thickness of a base film can employ | adopt arbitrary appropriate thickness in the range which does not impair the effect of this invention. The thickness of the substrate film is preferably 1 μm to 500 μm, more preferably 5 μm to 400 μm, still more preferably 10 μm to 200 μm, particularly preferably 20 μm to 20 nm in that the effect of the present invention can be further developed. It is 150 μm. When the thickness of the substrate film is less than 5 μm, it is difficult to maintain the shape of the sheet, and the sheet may be wrinkled during sticking, resulting in sticking failure such as generation of non-adhered air bubbles. When the thickness of the substrate film exceeds 500 μm, a large force is required to bend the sheet at the time of peeling, and a large stress may be applied to the adherend, which may cause the adherend to break.

As a base film, any appropriate base film can be adopted as long as the effects of the present invention are not impaired. Such a substrate film is preferably a plastic film. As a constituent material of the plastic film, for example, low density polyethylene, linear polyethylene, medium density polyethylene, high density polyethylene, ultra low density polyethylene, random copolymer polypropylene, block copolymer polypropylene, homopolypropylene, polybutene, polymethylpentene Etc .; ethylene-vinyl acetate copolymer; ionomer resin; ethylene- (meth) acrylic acid copolymer; ethylene- (meth) acrylic acid ester (random, alternating) copolymer; ethylene-butene copolymer; Ethylene-hexene copolymer; polyurethane; polyester such as polyethylene terephthalate; polyimide; polyether ketone; polystyrene; polyvinyl chloride; polyvinylidene chloride; fluorocarbon resin; silicone resin; ; A cross-linked product thereof; and the like. The constituent material of the base film may be only one type, or two or more types. For example, it may be composed of two or more types of plastics.

The surface of the base film may be subjected to any appropriate surface treatment as long as the effects of the present invention are not impaired in order to improve the adhesion, the holding property and the like with the adjacent layer. Examples of such surface treatment include chemical or physical treatments such as chromic acid treatment, ozone exposure, flame exposure, high piezoelectric bombardment exposure, ionizing radiation treatment, etc .; coating treatment;

The surface of the base film may be provided with a deposited layer of a conductive material having a thickness of 30 Å to 500 Å, made of a metal, an alloy, or an oxide thereof, in order to provide antistatic performance.

The base film may contain any appropriate additive, as long as the effects of the present invention are not impaired. As an additive which may be contained in a substrate film, for example, an antioxidant, an ultraviolet absorber, a light stabilizer, an antistatic agent, a filler, a pigment, a surfactant, an inorganic salt, a polyhydric alcohol, a metal compound, carbon Etc., low molecular weight antistatic agents, high molecular weight antistatic agents and the like. The type, number, and amount of additives that can be contained in the substrate film can be appropriately set depending on the purpose.

As a method for producing a substrate film, any appropriate method can be adopted as long as the effects of the present invention are not impaired. As such a method, for example, a calendar method, a casting method, an inflation method, a T-die extrusion method and the like can be mentioned. Moreover, you may use a commercially available plastic film as a base film.

<A-2. Adhesive layer>
The pressure-sensitive adhesive layer may be produced by any suitable production method. As such a manufacturing method, for example, a pressure-sensitive adhesive composition which is a material for forming a pressure-sensitive adhesive layer is applied onto any appropriate substrate (for example, a substrate film) to form a pressure-sensitive adhesive layer on the substrate Methods are included. As a method of such application, any suitable application method can be mentioned as long as the effects of the present invention are not impaired. Examples of such a coating method include roll coating, gravure coating, reverse coating, roll brushing, spray coating, air knife coating, extrusion coating using a die coater, and the like.

The pressure-sensitive adhesive layer may be only one layer or two or more layers.

As the thickness of the pressure-sensitive adhesive layer, any appropriate thickness can be adopted as long as the effects of the present invention are not impaired. The thickness of the pressure-sensitive adhesive layer is preferably 0.1 μm to 500 μm, more preferably 1 μm to 300 μm, still more preferably 3 μm to 200 μm, and particularly preferably, in that the effects of the present invention can be further developed. 5 μm to 100 μm. When the thickness of the pressure-sensitive adhesive layer is less than 0.1 μm, the fine unevenness of the adherend can not be followed, and the intermolecular force is less likely to be generated. When the thickness of the pressure-sensitive adhesive layer exceeds 500 μm, the cohesive force of the pressure-sensitive adhesive is insufficient, and there is a possibility that breakage in the thickness direction of the pressure-sensitive adhesive, that is, adhesive residue may occur.

The pressure-sensitive adhesive layer is composed of a pressure-sensitive adhesive. The adhesive is formed from an adhesive composition. That is, the pressure-sensitive adhesive layer is composed of a pressure-sensitive adhesive formed of a pressure-sensitive adhesive composition. Therefore, among various components contained in the pressure-sensitive adhesive composition, components which do not change due to reaction or the like when forming the pressure-sensitive adhesive are also contained in the pressure-sensitive adhesive layer as they are.

The pressure-sensitive adhesive composition contains a base polymer. As a base polymer, any suitable base polymer can be adopted as long as the effects of the present invention are not impaired. In addition, a base polymer said here is a base polymer contained in an adhesive composition, and it distinguishes from the "base polymer which has a three-dimensional network structure" (after-mentioned) formed from this base polymer. Such a base polymer is preferably a polyurethane-based resin in that the effects of the present invention can be further exhibited.

<A-2-1. Photopolymerization initiator>
The pressure-sensitive adhesive layer preferably contains a photopolymerization initiator that generates radicals by ultraviolet irradiation. When the pressure-sensitive adhesive layer contains a photopolymerization initiator that generates radicals by ultraviolet irradiation, when the surface protection sheet for an optical member is irradiated with ultraviolet light, photopolymerization of components contained in the pressure-sensitive adhesive layer may start. In the present invention, by irradiating the surface protection sheet for an optical member with ultraviolet light, the adhesion of the pressure-sensitive adhesive layer is reduced, and excellent light releasability can be exhibited.

As a photoinitiator, in the range which does not impair the effect of this invention, arbitrary appropriate photoinitiators can be employ | adopted. Such photopolymerization initiators include, for example, benzoin alkyl ethers such as benzoin methyl ether, benzoisopropyl ether, benzoin isopropyl ether, benzoin isobutyl ether; benzyl, benzoin, benzophenone, α-hydroxycyclohexyl phenyl ketones Aromatic ketones such as benzyl dimethyl ketal; polyvinyl benzophenone, chlorothioxanthone, dodecyl thioxanthone, thioxanthones such as dimethyl thioxanthone, and the like; and the like.

A commercial item may be used as a photoinitiator. For example, BASF brand names “IRGACURE 651”, “IRGACURE 184”, “IRGACURE 369”, “IRGACURE 819”, “IRGACURE 2959”, etc. may be mentioned.

The content ratio of the photopolymerization initiator in the adhesive layer is preferably 0.01 parts by weight to 20 parts by weight, more preferably 0.1 parts by weight to 10 parts by weight with respect to 100 parts by weight of the base polymer. More preferably, it is 0.5 parts by weight to 10 parts by weight, and particularly preferably 0.7 parts by weight to 5 parts by weight.

The photoinitiator which may be contained in the pressure-sensitive adhesive layer may be an embodiment contained in the pressure-sensitive adhesive composition as an embodiment of the content thereof. In this case, the content ratio of the photopolymerization initiator in the adhesive composition is preferably 0.01 parts by weight to 20 parts by weight, more preferably 0.1 parts by weight to 100 parts by weight of the base polymer. The amount is 10 parts by weight, more preferably 0.5 parts by weight to 10 parts by weight, and particularly preferably 0.7 parts by weight to 5 parts by weight.

A-2-2. Polymerizable carbon-carbon double bond>
The pressure-sensitive adhesive layer preferably contains a polymerizable carbon-carbon double bond. The polymerizable carbon-carbon double bond is preferably a radically polymerizable carbon-carbon double bond. When the pressure-sensitive adhesive layer contains a polymerizable carbon-carbon double bond, when the surface protection sheet for an optical member is irradiated with active energy rays, preferably, a base polymer having a three-dimensional network structure is formed in the pressure-sensitive adhesive layer. And the adhesion of the pressure-sensitive adhesive layer is reduced. Thereby, the surface protection sheet for optical members can express the outstanding light peelability by ultraviolet irradiation. When the base polymer having a three-dimensional network structure is formed by irradiation with active energy rays, the polymerizable carbon-carbon double bond is consumed, and therefore, the adherend at the time of peeling the surface protection sheet for an optical member from the adherend The contamination of the adherend can be reduced, and therefore, the residual adhesion of the surface protective sheet for an optical member can be sufficiently developed.

The pressure-sensitive adhesive layer may contain a bifunctional or more polymerizable carbon-carbon double bond. “Containing a bifunctional or higher polymerizable carbon-carbon double bond” is typically including two or more functional groups containing a polymerizable carbon-carbon double bond.

The polymerizable carbon-carbon double bond is preferably a polymerizable carbon-carbon double bond that at least one group selected from an acryloyl group and a methacryloyl group has.

Therefore, the pressure-sensitive adhesive layer preferably contains at least one group selected from acryloyl group and methacryloyl group, preferably two or more.

The polymerizable carbon-carbon double bond is preferably “a difunctional or higher functional group” described later in the section of <A-2-3-1-2.2 Compound Having Polymerizable Carbon-Carbon Double Bond of Function or More> A polymerizable carbon-carbon double bond derived from a compound having a polymerizable carbon-carbon double bond, <A-2-3-1-3. Polymerizable carbon-carbon double bonds derived from “polyols having polymerizable carbon-carbon double bonds” described later in the section of Polymerizable Carbon-Carbon Double Bonds>, <A-2-3- 2-1. Polyurethane Resin This is a polymerizable carbon-carbon double bond derived from the "polyurethane resin" described later in the section of ".

<A-2-3. Adhesive composition>
The content ratio of the base polymer in the pressure-sensitive adhesive composition is preferably 30% by weight or more, more preferably 30% by weight to 100% by weight, still more preferably 40% by weight to 99% by weight, particularly preferably Is 50% to 97% by weight, most preferably 60% to 95% by weight. Typically, the content of polyurethane resin in the adhesive layer is preferably 30% by weight or more, more preferably 30% by weight to 100% by weight, and still more preferably 40% by weight to 99% by weight Particularly preferably, it is 50% by weight to 97% by weight, and most preferably 60% by weight to 95% by weight.

The base polymer in the pressure-sensitive adhesive composition may be only one type or two or more types.

In the production of the base polymer, the materials may be added at once into the reaction vessel and reacted depending on the materials used, and some materials are added to the reaction vessel during the reaction to control the reaction You may

In the production of the base polymer, heating is preferred to accelerate the polymerization reaction. The heating temperature can be set to any appropriate value depending on the boiling point of the solvent used. The heating temperature is preferably 40.degree. C. to 100.degree.

In the production of the base polymer, if the moisture in the reaction atmosphere is removed as much as possible, for example, the deactivation of the isocyanate crosslinking agent can be prevented.

In the production of the base polymer, any suitable polymerization inhibitor may be added as required.

In the preparation of the base polymer, any suitable reaction catalyst may be further added to facilitate the reaction. As such a reaction catalyst, for example, dibutyltin dilaurate IV, cobalt naphthenate, stannous chloride, stannic chloride, tetra-n-butyltin, trimethyltin hydroxide, stannous octoate, diethyltin dichloride and the like Metal-based catalysts; chelates of metals such as nickel, zinc, lead, copper, titanium, zirconium, iron, calcium, cobalt and the like; tetramethylbutanediamine, 1,4-diazabicyclo [2,2,2] octane, 1,8 -Diazabicyclo [5,4,0] undensene-7, tertiary amine catalysts such as triethylenediamine; and the like. The amount of the catalyst used may be appropriately set in accordance with the preparation amount of various materials used for the reaction.

<A-2-3-1. Embodiment 1 of Pressure-Sensitive Adhesive Composition>
One embodiment (embodiment 1) of the pressure-sensitive adhesive composition contains a polyurethane-based resin as a base polymer, a compound having a polymerizable carbon-carbon double bond, and an isocyanate-based crosslinking agent. The polyurethane resin may be only one kind or two or more kinds. The compound having a polymerizable carbon-carbon double bond may be only one type or two or more types. The isocyanate crosslinking agent may be only one kind or two or more kinds.

The compound having a polymerizable carbon-carbon double bond is, in a preferable embodiment, a compound having a bifunctional or more polymerizable carbon-carbon double bond, and in another preferable embodiment, It is a polyol having a polymerizable carbon-carbon double bond.

<A-2-3-1-1. Polyurethane resin>
In the first embodiment, any appropriate polyurethane resin may be adopted as the polyurethane resin as long as the effects of the present invention are not impaired. The polyurethane resin is preferably a polyurethane resin formed of a composition containing a polyol (A) and a polyfunctional isocyanate compound (B), or a urethane prepolymer (C) and a polyfunctional isocyanate compound (B) A polyurethane resin formed from a composition containing

In Embodiment 1, the polyurethane-based resin may contain any appropriate component as long as the effects of the present invention are not impaired. Such components include, for example, resin components other than urethane resins, tackifiers, inorganic fillers, organic fillers, metal powders, pigments, foils, softeners, anti-aging agents, conductive agents, ultraviolet light absorption Agents, antioxidants, light stabilizers, surface lubricants, leveling agents, corrosion inhibitors, heat resistant stabilizers, polymerization inhibitors, lubricants, solvents, catalysts and the like. Such components may be only one kind or two or more kinds.

<A-2-3-1-1-1. Polyurethane resin formed from composition containing polyol (A) and polyfunctional isocyanate compound (B)>
Specifically, a polyurethane resin formed from a composition containing a polyol (A) and a polyfunctional isocyanate compound (B) is preferably a composition containing a polyol (A) and a polyfunctional isocyanate compound (B) It is a polyurethane resin obtained by curing a substance.

The polyol (A) may be only one kind or two or more kinds.

The polyfunctional isocyanate compound (B) may be only one kind or two or more kinds.

Any appropriate polyol (A) can be adopted as the polyol (A) as long as the effects of the present invention are not impaired. Examples of such polyols (A) include dihydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, butylene glycol and hexamethylene glycol; trihydric alcohols such as trimethylolpropane and glycerin; and tetravalents such as pentaerythritol Alcohols: Polyether polyols obtained by addition polymerization of ethylene oxide, propylene oxide, tetrahydrofuran, etc. Dihydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, hexamethylene glycol, etc., dipropylene glycol, 1,4- Alcohols such as butanediol, 1,6-hexanediol, neopentyl glycol, etc. and divalent basic acids such as adipic acid, azelaic acid, sebacic acid Polyester polyols composed of polycondensates of acrylic acid; copolymers of monomers having a hydroxyl group such as hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate, and acrylic polyols such as copolymers of a hydroxyl group-containing substance and an acrylic monomer; Carbonate polyols; epoxy polyols such as amine-modified epoxy resins; caprolactone polyols; and the like. As a polyol (A), Preferably, a bivalent alcohol, polyether polyol, polyester polyol is mentioned.

As the polyether polyol, more specifically, for example, water, low molecular weight polyol (ethylene glycol, propylene glycol, glycerin, trimethylolpropane, pentaerythritol etc.), bisphenols (bisphenol A etc.), dihydroxybenzene (catechol, resorcinol) And polyether polyols obtained by the addition polymerization of alkylene oxides such as ethylene oxide, propylene oxide and butylene oxide using an initiator such as hydroquinone, etc. as an initiator. Specifically, for example, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol and the like can be mentioned.

As polyester polyol, it can obtain in more detail, for example, by the esterification reaction of a polyol component and an acid component. As the polyol component, for example, ethylene glycol, diethylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-butyl-2-ethyl-1 2,3-propanediol, 2,4-diethyl-1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 2-methyl -1,8-octanediol, 1,8-decanediol, octadecanediol, glycerin, trimethylolpropane, pentaerythritol, hexanetriol, polypropylene glycol and the like. Examples of the acid component include succinic acid, methyl succinic acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,12-dodecanedioic acid, 1,14-tetradecanedioic acid, dimer acid, 2-methyl-1, 4-cyclohexanedicarboxylic acid, 2-ethyl-1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid And these acid anhydrides and the like.

The number average molecular weight Mn of the polyol (A) is preferably 300 to 100,000, more preferably 400 to 75,000, still more preferably 450 to 50,000, and particularly preferably 500 to 30,000. The wettability of the pressure-sensitive adhesive layer can be further improved by adjusting the number average molecular weight Mn of the polyol (A) within the above range.

As the polyfunctional isocyanate compound (B), any suitable polyfunctional isocyanate compound that can be used for the urethanation reaction can be adopted. As such a polyfunctional isocyanate compound (B), a polyfunctional aliphatic isocyanate compound, a polyfunctional alicyclic isocyanate, a polyfunctional aromatic isocyanate compound etc. are mentioned, for example.

Examples of polyfunctional aliphatic isocyanate compounds include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, 2,4, 4-trimethylhexamethylene diisocyanate and the like.

As a polyfunctional alicyclic isocyanate compound, for example, 1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, Hydrogenated tolylene diisocyanate, hydrogenated tetramethyl xylylene diisocyanate and the like can be mentioned.

Examples of polyfunctional aromatic diisocyanate compounds include phenylene diisocyanate, 2,4-tolylene diisosoanate, 2,6-tolylene diisocyanate, 2,2′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-toluidine diisocyanate, 4,4′-diphenyl ether diisocyanate, 4,4′-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, xylylene diisocyanate and the like.

Examples of the polyfunctional isocyanate compound (B) include trimethylolpropane adducts of various polyfunctional isocyanate compounds as described above, a biuret reacted with water, and a trimer having an isocyanurate ring. Moreover, you may use these together.

The equivalent ratio of NCO groups to OH groups in the polyol (A) and the polyfunctional isocyanate compound (B) is preferably 5.0 or less, more preferably 0.1 to 3.0, as NCO group / OH group. More preferably, it is 0.2 to 2.5, particularly preferably 0.3 to 2.25, and most preferably 0.5 to 2.0. The wettability of the pressure-sensitive adhesive layer can be further improved by adjusting the NCO group / OH group equivalent ratio within the above range.

The content ratio of the polyfunctional isocyanate compound (B) is preferably 1.0% by weight to 30% by weight, more preferably 1.5% by weight, of the polyfunctional isocyanate compound (B) with respect to the polyol (A). % To 27% by weight, more preferably 2.0% to 25% by weight, particularly preferably 2.3% to 23% by weight, most preferably 2.5% to 20% by weight It is. The wettability of the pressure-sensitive adhesive layer can be further improved by adjusting the content ratio of the polyfunctional isocyanate compound (B) within the above range.

As a method of curing a composition containing a polyol (A) and a polyfunctional isocyanate compound (B) to form a polyurethane resin, the effects of the present invention, such as a urethanization reaction method using bulk polymerization or solution polymerization, etc. Any appropriate method may be adopted as long as the

In order to cure the composition containing the polyol (A) and the polyfunctional isocyanate compound (B), a catalyst is preferably used. As such a catalyst, an organometallic compound, a tertiary amine compound, etc. are mentioned, for example.

Examples of the organic metal compound include iron compounds, tin compounds, titanium compounds, zirconium compounds, lead compounds, cobalt compounds, zinc compounds and the like. Among these, iron-based compounds and tin-based compounds are preferable in terms of the reaction rate and the pot life of the pressure-sensitive adhesive layer.

Examples of the iron-based compound include iron acetylacetonate and iron 2-ethylhexanoate.

Examples of tin compounds include dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin maleate, dibutyltin dilaurate, dibutyltin diacetate, dibutyltin sulfide, tributyltin methoxide, tributyltin acetate, triethyltin ethoxide, Examples thereof include tributyltin ethoxide, dioctyltin oxide, dioctyltin dilaurate, tributyltin chloride, tributyltin trichloroacetate, tin 2-ethylhexanoate and the like.

Examples of titanium-based compounds include dibutyl titanium dichloride, tetrabutyl titanate, butoxy titanium trichloride and the like.

Examples of the zirconium-based compound include zirconium naphthenate and zirconium acetylacetonate.

Examples of lead-based compounds include lead oleate, lead 2-ethylhexanoate, lead benzoate and lead naphthenate.

Examples of cobalt-based compounds include cobalt 2-ethylhexanoate and cobalt benzoate.

Examples of zinc compounds include zinc naphthenate and zinc 2-ethylhexanoate.

Examples of tertiary amine compounds include triethylamine, triethylenediamine, 1,8-diazabiccyl- (5,4,0) -undecene-7 and the like.

The catalyst may be used alone or in combination of two or more. In addition, a catalyst and a crosslinking retarder may be used in combination. The amount of the catalyst is preferably 0.005 wt% to 1.00 wt%, more preferably 0.01 wt% to 0.75 wt%, further preferably 0 with respect to the polyol (A). .01% by weight to 0.50% by weight, particularly preferably 0.01% by weight to 0.20% by weight. By adjusting the amount of the catalyst within the above range, the wettability of the pressure-sensitive adhesive layer can be improved, so that the surface protective film of the present invention can be stuck without involving air bubbles.

The composition containing the polyol (A) and the polyfunctional isocyanate compound (B) may contain any appropriate other components as long as the effects of the present invention are not impaired. As such other components, for example, resin components other than polyurethane resins, tackifiers, inorganic fillers, organic fillers, metal powders, pigments, foils, softeners, anti-aging agents, conductive agents, Ultraviolet absorbers, antioxidants, light stabilizers, surface lubricants, leveling agents, corrosion inhibitors, heat resistant stabilizers, polymerization inhibitors, lubricants, solvents, catalysts, etc. may be mentioned.

<A-2-3-1-1-2. Polyurethane resin formed from composition containing urethane prepolymer (C) and polyfunctional isocyanate compound (B)>
The polyurethane resin formed from the composition containing the urethane prepolymer (C) and the polyfunctional isocyanate compound (B) is any polyurethane resin obtained by using a so-called "urethane prepolymer" as a raw material. Any suitable polyurethane resin may be employed.

The urethane resin formed from the composition containing a urethane prepolymer (C) and a polyfunctional isocyanate compound (B) contains, for example, a polyurethane polyol as a urethane prepolymer (C) and a polyfunctional isocyanate compound (B) And polyurethane resins formed from the composition. The urethane prepolymer (C) may be only one type or two or more types. The polyfunctional isocyanate compound (B) may be only one kind or two or more kinds.

The polyurethane polyol as urethane prepolymer (C) is preferably polyester polyol (a1) or polyether polyol (a2), each alone or in a mixture of (a1) and (a2), in the presence of a catalyst or It is obtained by reacting with an organic polyisocyanate compound (a3) under no catalyst.

Any appropriate polyester polyol may be used as the polyester polyol (a1). As such a polyester polyol (a1), the polyester polyol obtained by making an acid component and a glycol component react is mentioned, for example. Examples of the acid component include terephthalic acid, adipic acid, azelaic acid, sebacic acid, phthalic anhydride, isophthalic acid, trimellitic acid and the like. Examples of the glycol component include ethylene glycol, propylene glycol, diethylene glycol, butylene glycol, 1,6-hexane glycol, 3-methyl-1,5-pentanediol, 3,3'-dimethylol heptane, polyoxyethylene glycol, Polyoxypropylene glycol, 1,4-butanediol, neopentyl glycol, butylethyl pentanediol, glycerin as the polyol component, trimethylolpropane, pentaerythritol and the like. Other examples of the polyester polyol (a1) include polyester polyols obtained by ring-opening polymerization of lactones such as polycaprolactone, poly (β-methyl-γ-valerolactone) and polyvalerolactone.

As a molecular weight of polyester polyol (a1), it can be used from low molecular weight to high molecular weight. The number average molecular weight of the polyester polyol (a1) is preferably 100 to 100,000. If the number average molecular weight is less than 100, the reactivity is high, and there is a possibility that the gelation tends to occur. If the number average molecular weight exceeds 100,000, the reactivity may be lowered, and furthermore, the cohesion of the polyurethane polyol may be reduced. The amount of polyester polyol (a1) used is preferably 0 mol% to 90 mol% in the polyol constituting the polyurethane polyol.

Any appropriate polyether polyol may be used as the polyether polyol (a2). As such a polyether polyol (a2), for example, low molecular weight polyols such as water, propylene glycol, ethylene glycol, glycerin and trimethylolpropane are used as an initiator, and ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran and the like are used. The polyether polyol obtained by polymerizing an oxirane compound is mentioned. Specific examples of such polyether polyols (a2) include polyether polyols having a functional group number of 2 or more, such as polypropylene glycol, polyethylene glycol, polytetramethylene ether glycol and the like.

As molecular weight of polyether polyol (a2), it can be used from low molecular weight to high molecular weight. The number average molecular weight of the polyether polyol (a2) is preferably 100 to 100,000. If the number average molecular weight is less than 100, the reactivity is high, and there is a possibility that the gelation tends to occur. If the number average molecular weight exceeds 100,000, the reactivity may be lowered, and furthermore, the cohesion of the polyurethane polyol may be reduced. The amount of polyether polyol (a2) used is preferably 0 mol% to 90 mol% in the polyol constituting the polyurethane polyol.

The polyether polyol (a2) may be partially a glycol, such as ethylene glycol, 1,4-butanediol, neopentyl glycol, butylethyl pentanediol, glycerin, trimethylolpropane or pentaerythritol, as necessary. It can be used in combination with polyvalent amines such as ethylene diamine, N-aminoethyl ethanolamine, isophorone diamine, xylylene diamine and the like.

As the polyether polyol (a2), only a bifunctional polyether polyol may be used, or a polyether having a number average molecular weight of 100 to 100,000 and having at least three or more hydroxyl groups in one molecule. A polyol may be used partially or entirely. When a polyether polyol having a number average molecular weight of 100 to 100000 and having at least three or more hydroxyl groups in one molecule is used partially or entirely as the polyether polyol (a2), adhesion and removability can be obtained. Balance may be good. In such a polyether polyol, when the number average molecular weight is less than 100, the reactivity is high, and there is a possibility that the gelation tends to occur. In addition, in such a polyether polyol, when the number average molecular weight exceeds 100,000, the reactivity may be lowered, and furthermore, the cohesion of the polyurethane polyol may be reduced. The number average molecular weight of such a polyether polyol is more preferably 100 to 10000.

Any appropriate organic polyisocyanate compound may be used as the organic polyisocyanate compound (a3). As such an organic polyisocyanate compound (a3), aromatic polyisocyanate, aliphatic polyisocyanate, araliphatic polyisocyanate, alicyclic polyisocyanate etc. are mentioned, for example.

Examples of aromatic polyisocyanates include 1,3-phenylene diisocyanate, 4,4′-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6 -Tolylene diisocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4 ', 4 "-triphenylmethane triisocyanate and the like.

Examples of aliphatic polyisocyanates include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, And 2,4,4-trimethylhexamethylene diisocyanate.

As the aromatic aliphatic polyisocyanate, for example, ω, ω′-diisocyanate-1,3-dimethylbenzene, ω, ω′-diisocyanate-1,4-dimethylbenzene, ω, ω′-diisocyanate-1,4-diethylbenzene And 1,4-tetramethyl xylylene diisocyanate and 1,3-tetramethyl xylylene diisocyanate.

As an alicyclic polyisocyanate, for example, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, 1,3-cyclopentadiisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2 2,4-cyclohexanediisocyanate, methyl-2,6-cyclohexanediisocyanate, 4,4'-methylenebis (cyclohexylisocyanate), 1,4-bis (isocyanatomethyl) cyclohexane and the like.

As the organic polyisocyanate compound (a3), a trimethylolpropane adduct, a biuret reacted with water, a trimer having an isocyanurate ring, and the like can be used in combination.

Any suitable catalyst may be used as the catalyst that can be used to obtain the polyurethane polyol. Examples of such a catalyst include tertiary amine compounds, organic metal compounds and the like.

Examples of tertiary amine compounds include triethylamine, triethylenediamine, 1,8-diazabicyclo (5,4,0) -undecene-7 (DBU) and the like.

Examples of the organic metal compound include tin compounds and non-tin compounds.

Examples of tin compounds include dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, dibutyltin dilaurate (DBTDL), dibutyltin diacetate, dibutyltin sulfide, tributyltin sulfide, tributyltin oxide, and tributyltin. Tin acetate, triethyltin ethoxide, tributyltin ethoxide, dioctyltin oxide, tributyltin chloride, tributyltin trichloroacetate, tin 2-ethylhexanoate and the like can be mentioned.

Examples of non-tin compounds include titanium compounds such as dibutyl titanium dichloride, tetrabutyl titanate and butoxy titanium trichloride; lead compounds such as lead oleate, lead 2-ethylhexanoate, lead benzoate and lead naphthenate Iron compounds such as iron 2-ethylhexanoate and iron acetylacetonate cobalt compounds such as cobalt benzoate and cobalt 2-ethylhexanoate zinc compounds such as zinc naphthenate and zinc 2-ethylhexanoate; Zirconium-based compounds such as zirconium naphthenate; and the like.

When a catalyst is used to obtain a polyurethane polyol, in a system in which two types of polyols, polyester polyol and polyether polyol, exist, gelation or a reaction solution occurs in a single catalyst system due to the difference in reactivity. It is easy to cause the problem of becoming cloudy. Therefore, the reaction rate, the selectivity of the catalyst, and the like can be easily controlled by using two types of catalysts when obtaining the polyurethane polyol, and these problems can be solved. Examples of combinations of such two types of catalysts include tertiary amines / organic metals, tin-based / non-tin-based, tin-based / tin-based, and preferably tin-based / tin-based, more preferably Is a combination of dibutyltin dilaurate and tin 2-ethylhexanoate. The compounding ratio is preferably less than 1, and more preferably 0.2 to 0.6, in terms of weight ratio, tin 2-ethylhexanoate / dibutyltin dilaurate. When the compounding ratio is 1 or more, there is a possibility that gelation may be facilitated due to the balance of catalyst activity.

When a catalyst is used to obtain a polyurethane polyol, the amount of the catalyst used is preferably 0.01 with respect to the total of the polyester polyol (a1), the polyether polyol (a2) and the organic polyisocyanate compound (a3). It is ̃1.0 wt%.

When a catalyst is used in obtaining the polyurethane polyol, the reaction temperature is preferably less than 100 ° C., more preferably 85 ° C. to 95 ° C. When the temperature is 100 ° C. or higher, control of the reaction rate and the crosslinked structure may be difficult, and it may be difficult to obtain a polyurethane polyol having a predetermined molecular weight.

When obtaining a polyurethane polyol, it is not necessary to use a catalyst. In that case, the reaction temperature is preferably 100 ° C. or more, more preferably 110 ° C. or more. Moreover, when obtaining a polyurethane polyol under a non-catalyst, it is preferable to make it react for 3 hours or more.

As a method of obtaining a polyurethane polyol, for example, 1) a method of charging a polyester polyol, a polyether polyol, a catalyst, and an organic polyisocyanate all in a flask, 2) a polyester polyol, a polyether polyol, a catalyst is charged into a flask and an organic polyisocyanate is charged. Is added dropwise. As a method of obtaining a polyurethane polyol, the method 2) is preferable in controlling the reaction.

Any suitable solvent may be used in obtaining the polyurethane polyol. As such solvent, for example, methyl ethyl ketone, ethyl acetate, toluene, xylene, acetone and the like can be mentioned. Among these solvents, preferred is toluene.

As the polyfunctional isocyanate compound (B), those described above can be incorporated.

The composition containing the urethane prepolymer (C) and the polyfunctional isocyanate compound (B) may contain any appropriate other components as long as the effects of the present invention are not impaired. As such other components, for example, resin components other than polyurethane resins, tackifiers, inorganic fillers, organic fillers, metal powders, pigments, foils, softeners, anti-aging agents, conductive agents, Ultraviolet absorbers, antioxidants, light stabilizers, surface lubricants, leveling agents, corrosion inhibitors, heat resistant stabilizers, polymerization inhibitors, lubricants, solvents, catalysts, etc. may be mentioned.

As a method for producing a polyurethane-based resin formed from a composition containing a urethane prepolymer (C) and a polyfunctional isocyanate compound (B), a polyurethane-based resin is produced using a so-called "urethane prepolymer" as a raw material Any appropriate manufacturing method may be employed as long as it is a method.

The number average molecular weight Mn of the urethane prepolymer (C) is preferably 3,000 to 1,000,000.

The equivalent ratio of NCO groups to OH groups in the urethane prepolymer (C) and the polyfunctional isocyanate compound (B) is preferably 5.0 or less, more preferably 0.01 to 3 as NCO group / OH group. Is more preferably 0.02 to 2.5, particularly preferably 0.03 to 2.25, and most preferably 0.05 to 2.0. The wettability of the pressure-sensitive adhesive layer can be further improved by adjusting the NCO group / OH group equivalent ratio within the above range.

The content ratio of the polyfunctional isocyanate compound (B) is preferably 0.01% by weight to 30% by weight, and more preferably 0.% by weight of the polyfunctional isocyanate compound (B) based on the urethane prepolymer (C). It is 03 wt% to 20 wt%, more preferably 0.05 wt% to 15 wt%, particularly preferably 0.075 wt% to 10 wt%, and most preferably 0.1 wt% to 8 It is weight%. The wettability of the pressure-sensitive adhesive layer can be further improved by adjusting the content ratio of the polyfunctional isocyanate compound (B) within the above range.

<A-2-3-1-2.2 Compound Having Polymerizable Carbon-Carbon Double Bond of Function or Higher>
As the compound having a bifunctional or more polymerizable carbon-carbon double bond, a compound having any suitable bifunctional or more polymerizable carbon-carbon double bond is employed within a range not impairing the effects of the present invention. obtain. Examples of such a compound having a bifunctional or higher polymerizable carbon-carbon double bond include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1 Esters of (meth) acrylic acid with polyhydric alcohols such as 1,6-hexanediol (meth) acrylate, neopentyl glycol di (meth) acrylate, dipentaerythritol hexa (meth) acrylate; ester acrylate oligomers; 2-propenyl And cyanurate or isocyanurate compounds such as -3-butenyl cyanurate, tris (2-methacryloxyethyl) isocyanurate, and the like.

The content ratio of the compound having a bifunctional or higher polymerizable carbon-carbon double bond in the pressure-sensitive adhesive composition is preferably 1 part by weight to 70 parts by weight with respect to 100 parts by weight of polyurethane resin as a base polymer. More preferably, it is 3 parts by weight to 50 parts by weight, still more preferably 6 parts by weight to 55 parts by weight, and particularly preferably 10 parts by weight to 50 parts by weight. If the content ratio of the compound having a bifunctional or higher polymerizable carbon-carbon double bond in the pressure-sensitive adhesive composition is within the above range, strong tackiness can be further expressed, the light peelability is excellent, and the residual tackiness is obtained. The surface protection sheet for optical members which can express more sufficiently and can express favorable pastability more even if pasting pressure is low can be provided.

<A-2-3-1-3. Polyol having polymerizable carbon-carbon double bond>
As the polyol having a polymerizable carbon-carbon double bond, any suitable polyol having a polymerizable carbon-carbon double bond can be adopted as long as the effect of the present invention is not impaired. As the polyol having such a polymerizable carbon-carbon double bond, for example, (meth) acrylic acid or (meth) acrylate having a carboxyl group is added to the epoxy group of a compound having two or more epoxy groups. And monomers having a hydroxyl group such as the above-mentioned compounds. Specifically as such a polyol having a polymerizable carbon-carbon double bond, for example, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol Diglycidyl ether, polypropylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,5-pentanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, 1,9-nonanediol diglycidyl ether Neopentyl glycol diglycidyl ether, cyclohexane dimethanol diglycidyl ether, bisphenol A diglycidyl ether, hydrogenated bisphenol Le A diglycidyl ether, and glycerin diglycidyl ether.

As the polyol having a polymerizable carbon-carbon double bond, a commercially available product may be used. As such a commercial item, "epoxy ester" series, such as a brand name "epoxyester 200PA" and "epoxyester 70PA" by Kyoeisha Chemical Co., Ltd., etc. are mentioned, for example.

The content ratio of the polyol having a polymerizable carbon-carbon double bond in the pressure-sensitive adhesive composition is preferably 1 part by weight to 70 parts by weight, more preferably 100 parts by weight of polyurethane resin as a base polymer. Is from 3 to 50 parts by weight, more preferably from 6 to 55 parts by weight, and particularly preferably from 10 to 50 parts by weight. If the content ratio of the polyol having a polymerizable carbon-carbon double bond in the pressure-sensitive adhesive composition is within the above range, strong adhesiveness can be expressed more, light releasability is more excellent, and residual adhesive power is sufficiently expressed. It is possible to provide a surface protection sheet for an optical member, which can exhibit good adhesion even if the adhesion pressure is low.

<A-2-3-1-4. Isocyanate crosslinker>
As an isocyanate type crosslinking agent, arbitrary suitable isocyanate type crosslinking agents can be employ | adopted in the range which does not impair the effect of this invention. Examples of such isocyanate-based crosslinking agents include aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and dimers and trimers of these diisocyanates. Specifically, tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, 1,3-phenylene diisocyanate, 1 2,4-phenylene diisocyanate, butane-1,4-diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, dicyclohexylmethane-4,4 -Diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, methylcyclohexane diisocyanate, m- Tetramethyl xylylene diisocyanate, and the like, and these dimers and trimers, polyphenyl methane polyisocyanate is used. Moreover, as said trimer, an isocyanurate type, a burette type, an allophanate type etc. are mentioned.

A commercial item may be used as an isocyanate type crosslinking agent. Commercially available polyisocyanates include, for example, trade name "Takenate 600" manufactured by Mitsui Chemicals, trade name "Duranate TPA 100" manufactured by Asahi Kasei Chemicals, trade name "Colonate L" manufactured by Nippon Polyurethane Industry Co., Ltd., "Colonate HL". “Coronato HK”, “Coronato HX”, “Coronato 2096” and the like.

The content ratio of the isocyanate-based crosslinking agent in the pressure-sensitive adhesive composition is preferably 0.1 parts by weight to 50 parts by weight, and more preferably 0.5 parts by weight with respect to 100 parts by weight of the polyurethane resin as a base polymer. The amount is 40 to 40 parts by weight, more preferably 1 to 35 parts by weight, and particularly preferably 3 to 30 parts by weight. If the content ratio of the isocyanate-based crosslinking agent in the pressure-sensitive adhesive composition is within the above range, strong adhesiveness can be expressed more, light peelability is more excellent, residual adhesive power can be sufficiently expressed, and sticking pressure is low. The surface protection sheet for optical members which can also express favorable sticking property can be provided.

A-2-3-1-5. Other ingredients>
In Embodiment 1, the pressure-sensitive adhesive composition may contain any appropriate other components as long as the effects of the present invention are not impaired. As such other components, for example, resin components other than urethane resins, tackifiers, inorganic fillers, organic fillers, metal powders, pigments, foils, softeners, anti-aging agents, conductive agents, Ultraviolet absorbers, antioxidants, light stabilizers, surface lubricants, leveling agents, corrosion inhibitors, heat resistant stabilizers, polymerization inhibitors, lubricants, solvents, catalysts, etc. may be mentioned. The other components may be only one kind or two or more kinds.

<A-2-3-2. Embodiment 2 of Pressure-Sensitive Adhesive Composition>
In one embodiment (embodiment 2) of the pressure-sensitive adhesive composition, a polyurethane-based resin as a base polymer polymerizes a monomer composition containing a polyisocyanate and a monomer having at least two functional groups capable of reacting with isocyanate groups. And at least one selected from said monomers having at least two functional groups capable of reacting with said polyisocyanate and said isocyanate group has a polymerizable carbon-carbon double bond. The polyurethane resin may be only one kind or two or more kinds.

In Embodiment 2, preferably, the pressure-sensitive adhesive composition contains an isocyanate-based crosslinking agent. The isocyanate crosslinking agent may be only one kind or two or more kinds.

In Embodiment 2, the polyurethane resin may contain any appropriate component as long as the effects of the present invention are not impaired. Such components include, for example, resin components other than urethane resins, tackifiers, inorganic fillers, organic fillers, metal powders, pigments, foils, softeners, anti-aging agents, conductive agents, ultraviolet light absorption Agents, antioxidants, light stabilizers, surface lubricants, leveling agents, corrosion inhibitors, heat resistant stabilizers, polymerization inhibitors, lubricants, solvents, catalysts and the like. Such components may be only one kind or two or more kinds.

<A-2-3-2. Polyurethane resin>
In Embodiment 2, the polyurethane resin is obtained by polymerizing a monomer composition containing a polyisocyanate and a monomer having at least two functional groups capable of reacting with isocyanate groups, and can react with the polyisocyanate and the isocyanate groups. At least one selected from the monomers having at least two functional groups has a polymerizable carbon-carbon double bond.

In Embodiment 2, the polyurethane-based resin has a polymerizable carbon-carbon double bond in the resin.

In Embodiment 2, the polyurethane resin is obtained by polymerizing a monomer composition containing a polyisocyanate and a monomer having at least two functional groups capable of reacting with isocyanate groups. At this time, if at least one of the monomers having at least two functional groups capable of reacting with polyisocyanate and isocyanate group has a polymerizable carbon-carbon double bond, the polymerizable carbon-carbon double in polyurethane resin A bond is introduced.

A polyisocyanate having a polymerizable carbon-carbon double bond and a monomer having at least two functional groups capable of reacting with an isocyanate group having a polymerizable carbon-carbon double bond, relative to all monomer components used for producing a polyurethane-based resin The total content is preferably 1% to 70% by weight, more preferably 3% to 60% by weight, still more preferably 5% to 50% by weight, particularly preferably 10% by weight It is ̃40% by weight. A polyisocyanate having a polymerizable carbon-carbon double bond and a monomer having at least two functional groups capable of reacting with an isocyanate group having a polymerizable carbon-carbon double bond, relative to all monomer components used for producing a polyurethane-based resin If the total content ratio is within the above range, the effects of the present invention can be more exhibited.

The polymerizable carbon-carbon double bond is preferably such that the base polymer can form a three-dimensional network structure upon irradiation with active energy rays, and is preferably at least one group selected from acryloyl group and methacryloyl group. Is a polymerizable carbon-carbon double bond possessed by

Any appropriate polyisocyanate can be adopted as the polyisocyanate as long as the effects of the present invention are not impaired. Such polyisocyanates include, for example, aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and dimers and trimers of these diisocyanates. As such polyisocyanate, specifically, for example, tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, 1,5-naphthylene Isocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, butane-1,4-diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, cyclohexane-1, 4-diisocyanate, dicyclohexylmethane-4,4-diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexa , Methylcyclohexane diisocyanate, m- tetramethylxylylene diisocyanate, and the like, and these dimers and trimers, such as polyphenyl methane polyisocyanate. Moreover, as said trimer, an isocyanurate type, a burette type, an allophanate type etc. are mentioned. The polyisocyanate may be only one kind or two or more kinds.

As the polyisocyanate, a diisocyanate having two isocyanate groups in one molecule is preferable in that the effects of the present invention can be further developed. The content ratio of diisocyanate in the polyisocyanate used for producing the base polymer is preferably 50 wt% to 100 wt%, more preferably 75 wt% to 100 wt%, still more preferably 90 wt% to 100 wt%. %, Particularly preferably 95% to 100% by weight.

As a polyisocyanate having a polymerizable carbon-carbon double bond, any suitable polyisocyanate having a polymerizable carbon-carbon double bond can be adopted as long as the effect of the present invention is not impaired. Examples of such polyisocyanate having a polymerizable carbon-carbon double bond include polyisocyanates having a polymerizable carbon-carbon double bond-containing group such as a vinyl group, an acryloyl group and a methacryloyl group. The polyisocyanate having a polymerizable carbon-carbon double bond-containing group can be obtained, for example, by subjecting a polyisocyanate to a compound having a polymerizable carbon-carbon double bond-containing group. The polyisocyanate having a polymerizable carbon-carbon double bond-containing group may be only one type, or two or more types. Also, a polyisocyanate having a polymerizable carbon-carbon double bond-containing group and a polyisocyanate not having a polymerizable carbon-carbon double bond-containing group may be used in combination.

Examples of the compound having a polymerizable carbon-carbon double bond-containing group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, (meth ) 6-hydroxyhexyl acrylic acid, 8-hydroxyoctyl (meth) acrylic acid, 10-hydroxydecyl (meth) acrylic acid, 12-hydroxy lauryl (meth) acrylic acid, (4-hydroxymethylcyclohexyl) methyl ( And hydroxyl group-containing monomers such as (meth) acrylate; (meth) acrylamide and the like.

A commercial item may be used as polyisocyanate. Commercially available polyisocyanates include, for example, trade name "Takenate 600" manufactured by Mitsui Chemicals, trade name "Duranate TPA 100" manufactured by Asahi Kasei Chemicals, trade name "Colonate L" manufactured by Nippon Polyurethane Industry Co., Ltd., "Colonate HL". “Coronato HK”, “Coronato HX”, “Coronato 2096” and the like.

As a monomer (functional group-containing monomer) having at least two functional groups capable of reacting with an isocyanate group, any appropriate functional group-containing monomer can be adopted as long as the effects of the present invention are not impaired. As a functional group capable of reacting with an isocyanate group, any functional group that can be added to an isocyanate group and the polyisocyanate and the functional group-containing monomer can form a polymer can be used. The functional group capable of reacting with an isocyanate group is preferably at least one selected from the group consisting of a hydroxyl group, an amino group, and a carboxyl group. The functional groups contained in the functional group-containing monomer may all be the same functional group or may be different functional groups. The functional group capable of reacting with an isocyanate group is preferably a hydroxyl group in terms of easy reaction control. Therefore, as a functional group containing monomer, a polyol is preferable. The functional group-containing monomer may be only one type or two or more types.

Any appropriate polyol can be adopted as the polyol as long as the effects of the present invention are not impaired. Examples of low molecular weight polyols include dihydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, butylene glycol and hexamethylene glycol; trihydric alcohols such as trimethylolpropane and glycerin; tetrahydric alcohols such as pentaerythritol; Can be mentioned. Examples of high molecular weight polyols include polyether polyols obtained by addition polymerization of ethylene oxide, propylene oxide, tetrahydrofuran and the like; the above-mentioned dihydric alcohols, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, Polyester polyol consisting of polycondensate of alcohol such as neopentyl glycol and divalent basic acid such as adipic acid, azelaic acid and sebacic acid; having hydroxyl group such as hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate Acrylic polyols such as copolymers of monomers, copolymers of hydroxyl group-containing substances and acrylic monomers; carbonate polyols; epoxy polyols such as amine-modified epoxy resins; caprolactone polyols; and the like. The polyol is preferably a dihydric alcohol, a polyether polyol or a polyester polyol.

As a functional group containing monomer, you may use together the monomer which has functional groups other than a hydroxyl group. Examples of the monomer having a functional group other than a hydroxyl group include monomers having an amino group such as hexamethylenediamine, isophoronediamine, dichlorodiaminodiphenylmethane, diethyltoluenediamine, poly (propylene glycol) diamine, β-aminoethyl alcohol, etc .; adipic acid And monomers having a carboxyl group such as sebacic acid, isophthalic acid and terephthalic acid.

As a monomer having at least two functional groups capable of reacting with an isocyanate group having a polymerizable carbon-carbon double bond (functional group-containing monomer having a polymerizable carbon-carbon double bond), the effects of the present invention are not impaired In the range, any suitable functional group-containing monomer having a polymerizable carbon-carbon double bond may be employed. Examples of functional group-containing monomers having such a polymerizable carbon-carbon double bond include functional group-containing monomers having a polymerizable carbon-carbon double bond-containing group such as vinyl group, acryloyl group, methacryloyl group and the like. Be Specific examples of functional group-containing monomers having such a polymerizable carbon-carbon double bond include, for example, glycerin monomethacrylate, trimethylolpropane monoallyl ether, trimethylolethane mono (meth) acrylate and trimethylolpropane. Mono (meth) acrylate, pentaerythritol mono (meth) acrylate, pentaerythritol di (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate and the like can be mentioned.

As a functional group-containing monomer having a polymerizable carbon-carbon double bond, for example, (meth) acrylic acid or (meth) acrylate having a carboxyl group is added to the epoxy group of a compound having two or more epoxy groups And monomers having a hydroxyl group such as the above-mentioned compounds. Specific examples of such functional group-containing monomers having a polymerizable carbon-carbon double bond include ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, and propylene glycol diglycidyl ether. Tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,5-pentanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, 1,9-nonanediol di Glycidyl ether, neopentyl glycol diglycidyl ether, cyclohexane dimethanol diglycidyl ether, bisphenol A diglycidyl ether, hydrogenated biphenyl Phenol A diglycidyl ether, and glycerin diglycidyl ether.

Commercially available products may be used as the functional group-containing monomer having a polymerizable carbon-carbon double bond. Examples of such commercially available products include "Epoxy Ester" series such as "Epoxyester 200PA" manufactured by Kyoeisha Chemical Co., Ltd., "Epoxyester 70PA" and the like, "DA-314" manufactured by Nagase ChemteX, etc. And the "Denacol Acrylate" series.

Any appropriate compounding ratio may be adopted as the compounding ratio of the polyisocyanate and the functional group-containing monomer as long as the effects of the present invention are not impaired. The ratio of NCO equivalent / functional group equivalent (hereinafter referred to as NCO / functional group ratio) is preferably 0.5 to 2.0. By setting the NCO / functional group ratio to a value close to 1, it is possible to obtain a high molecular weight base polymer and to improve the cohesiveness of the obtained base polymer. If the NCO / functional ratio is within the above range, the cohesion of the obtained base polymer can be appropriately secured. When the NCO / functional ratio is less than 0.5 or more than 2.0, the molecular weight of the obtained base polymer may be low, and the cohesion may be low. If the cohesion of the resulting base polymer is low, an additional crosslinker may be added to ensure adequate cohesion. When the NCO / functional ratio is greater than 1 and isocyanate groups remain at the end of the base polymer, from the viewpoint of preventing modification by reaction of isocyanate groups with water during storage of the pressure-sensitive adhesive composition, Preferably, the terminal is modified by adding a functional group-containing monomer to The monomer added immediately before the completion of the polymerization may be the same as or different from the functional group-containing monomer used for the polymerization of the base polymer.

The polymerization reaction of the monomer components used for producing the polyurethane-based resin may be carried out in bulk or may be carried out by diluting in a solvent. As a solvent, any appropriate solvent can be adopted as long as the effects of the present invention are not impaired. Examples of such solvent include ethyl acetate, toluene, n-butyl acetate, n-hexane, cyclohexane, methyl ethyl ketone, methyl isobutyl ketone and the like. As a solvent, toluene or ethyl acetate is preferable in that the viscosity of the solution of the obtained base polymer can be adjusted appropriately. The solvent may be appropriately added during the polymerization reaction to adjust the viscosity of the obtained base polymer solution.

<A-2-3-2-2. Isocyanate crosslinker>
About the isocyanate type crosslinking agent which can be used in Embodiment 2, <A-2-3-1-3. Description of the isocyanate type crosslinking agent in item of isocyanate type crosslinking agent> can be used as it is.

<A-2-3-2-3. Other ingredients>
In Embodiment 2, the pressure-sensitive adhesive composition may contain any appropriate other components as long as the effects of the present invention are not impaired. As such other components, for example, resin components other than urethane resins, tackifiers, inorganic fillers, organic fillers, metal powders, pigments, foils, softeners, anti-aging agents, conductive agents, Ultraviolet absorbers, antioxidants, light stabilizers, surface lubricants, leveling agents, corrosion inhibitors, heat resistant stabilizers, polymerization inhibitors, lubricants, solvents, catalysts, etc. may be mentioned. The other components may be only one kind or two or more kinds.

EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. In addition, the test and evaluation method in an Example etc. are as follows. The term "parts" means "parts by weight" unless otherwise specified, and the term "%" means "% by weight" unless otherwise specified.

<Measurement of adhesive strength (A)>
The adhesive strength (A) was measured in accordance with JIS Z0237: 2009 in an environment at a temperature of 23 ± 1 ° C. and a humidity of 50 ± 5% RH. More specifically, the measurement was performed according to the contents of item 10 (adhesive force) in JIS Z0237: 2009. The width of the test piece was 24 ± 0.5 mm, and the adhesion value was converted to “N / 10 mm”. The test board used the SUS304BA board. Methyl ethyl ketone was used as a washing solvent for the test plate. The test piece and the test plate were attached to each other twice at 10 ± 0.5 mm / sec (600 ± 30 mm / min) using a 2 kg roller. The measurement of the peel adhesion strength according to JIS Z 0237: 2009, section 10.4, was performed according to method 1 of JIS Z 0237: 2009, section 10.4.1. The adhesion was measured within 1 minute after the application.

<Measurement of adhesion (B) after UV irradiation>
The adhesion after ultraviolet irradiation (B) was measured in accordance with JIS Z0237: 2009 in an environment at a temperature of 23 ± 1 ° C. and a humidity of 50 ± 5% RH. More specifically, the measurement was performed according to the contents of item 10 (adhesive force) in JIS Z0237: 2009. The width of the test piece was 24 ± 0.5 mm, and the adhesion value was converted to “N / 10 mm”. The test board used the SUS304BA board. Methyl ethyl ketone was used as a washing solvent for the test plate. The test piece and the test plate were attached to each other twice at 10 ± 0.5 mm / sec (600 ± 30 mm / min) using a 2 kg roller. The measurement of the peel adhesion strength according to JIS Z 0237: 2009, section 10.4, was performed according to method 1 of JIS Z 0237: 2009, section 10.4.1. However, UV irradiation (high pressure mercury lamp, 200 mW / cm ² , 440 mJ / cm ² ) was performed within 1 minute after sticking to the test plate, and peeling strength was measured within 10 minutes after UV irradiation. .

<Measurement of adhesive strength (C) after low pressure application>
The measurement of adhesive strength (C) after low pressure sticking was performed according to JIS Z0237: 2009 in an environment of temperature 23 ± 1 ° C. and humidity 50 ± 5% RH. More specifically, the measurement was performed according to the contents of item 10 (adhesive force) in JIS Z0237: 2009. The width of the test piece was 24 ± 0.5 mm, and the adhesion value was converted to “N / 10 mm”. The test board used the SUS304BA board. Methyl ethyl ketone was used as a washing solvent for the test plate. The measurement of the peel adhesion strength according to JIS Z 0237: 2009, section 10.4, was performed according to method 1 of JIS Z 0237: 2009, section 10.4.1. The adhesion was measured within 1 minute after the application. However, the adhesion between the test piece and the test plate was carried out by using a 200 g pressure roller and performing pressure bonding only once in one direction at a speed of 100 ± 5 mm / s to measure the adhesive strength.

<Measurement of residual adhesion (D) after UV irradiation>
The measurement of residual adhesive strength (D) after ultraviolet irradiation is carried out in the environment of temperature 23 ± 1 ° C. and humidity 50 ± 5% RH according to the measuring method of adhesive strength (B) after ultraviolet irradiation It peeled off from the test plate. However, the peeling from the test plate of the surface protection sheet for optical members was performed one day after affixing. Next, in a environment with a temperature of 23 ± 1 ° C and a humidity of 50 ± 5% RH, pull the adhesive tape (product name: No. 31B made by Nitto Denko Corporation) and cut the surface protection sheet for optical members. It stuck on the surface of the test board of the side which peeled off, and after leaving for 30 minutes, it peeled by the peeling angle of 180 degree, the peeling speed of 300 +/- 12 mm / min, and measured residual adhesive force (D) after ultraviolet irradiation. No. Affixing of 31B and the test plate was performed twice reciprocation at 600 ± 30 mm / sec using a 2 kg roller.

<Measurement of initial residual adhesion (E)>
The measurement of the initial residual adhesive force (E) was performed using a pressure-sensitive adhesive tape (product name: No. 31B, manufactured by Nitto Denko Corporation) cut into a width of 19 mm in an environment of temperature 23 ± 1 ° C. and humidity 50 ± 5% RH. It stuck on the surface of a test plate, and after leaving it to stand for 30 minutes, it exfoliated with exfoliation angle 180 degrees, and peeling speed 300 ± 12 mm / min, and measured initial stage residual adhesive power (E). The test board used the SUS304BA board. Methyl ethyl ketone was used as a washing solvent for the test plate. No. Affixing of 31B and the test plate was performed twice reciprocation at 600 ± 30 mm / sec using a 2 kg roller.

Synthesis Example 1 Urethane Polymer Solution A
1 L round bottom separable flask, separable cover, separation funnel, thermometer, nitrogen introduction tube, Liebig cooler, vacuum seal, stir bar, stirring blade, polymerization experimental equipment equipped with polypropylene glycol (product name " 200 g of Sannix PP-2000, manufactured by Sanyo Chemical Industries, Ltd. 200 g of polyester polyol (product name "Kuraray Polyol P-2010", manufactured by Kuraray), 150 g of toluene (manufactured by Tosoh Corp.) as solvent, dilauric acid as catalyst 0.055 g of dibutyl tin (IV) (manufactured by Wako Pure Chemical Industries, Ltd.) was added, and nitrogen substitution was carried out at normal temperature for 1 hour while stirring. Thereafter, 44.7 g of hexamethylene diisocyanate (trade name "HDI", manufactured by Tosoh Corporation) was added while stirring under nitrogen inflow, and control was performed so that the solution temperature in the experimental apparatus became 90 ± 2 ° C with a water bath. While holding for 4 hours, 99.8 g of polypropylene glycol (product name "GP1000", manufactured by Sanyo Chemical Industries, Ltd.) is added and controlled by a water bath so that the solution temperature in the experimental apparatus becomes 90 ± 2 ° C. While holding for 2 hours, add 1.4 g of hexamethylene diisocyanate (product name "HDI", manufactured by Tosoh Corporation), and control the temperature of the solution in the experimental apparatus to 90 ± 2 ° C with a water bath. The mixture was held for 2 hours to obtain a urethane polymer solution A. During the polymerization, toluene was dropped as appropriate in order to prevent temperature control during polymerization and a decrease in the stirring property due to the viscosity increase. The total amount of toluene dropped was 150 g. The solid content concentration of the urethane polymer solution A was 70% by weight.

Synthesis Example 2 Urethane Polymer Solution B
1 L round bottom separable flask, separable cover, separation funnel, thermometer, dry air inlet tube, Liebig cooler, vacuum seal, stir bar, stirring blade, polymerization experimental equipment equipped with polypropylene glycol (product name 150 g of "Sannicks PP-2000, Sanyo Chemical Industries, Ltd.", 150 g of a polymerizable carbon double bond-containing diol (product name "Epoxy Ester 200 PA", manufactured by Kyoeisha Chemical Co., Ltd.), toluene as a solvent (manufactured by Tosoh Corporation) 272 g, 0.2 g of dibutyltin dilaurate (IV) (manufactured by Wako Pure Chemical Industries, Ltd.) as a catalyst, 4 g of an antioxidant (product name “Irganox 1010”, manufactured by BASF), and stirring Dry air displacement was carried out for 1 hour at room temperature. After that, 76 g of hexamethylene diisocyanate (trade name "HDI", manufactured by Tosoh Corp.) was added while stirring under a flow of dry air, and the solution temperature was controlled by the water bath to 65 ± 2 ° C. While holding for 8 hours, 22 g of a polymerizable carbon double bond-containing diol (product name “epoxy ester 200 PA” manufactured by Kyoeisha Chemical Co., Ltd.), a polymerizable carbon double bond-containing triol (product name “Denacol acrylate DA- A urethane polymer solution B was obtained after adding 15 g of “314”, Nagase Chemtex Co., Ltd.) and holding it for 8 hours while controlling the solution temperature in the experimental apparatus to 65 ± 2 ° C. with a water bath. The solid content concentration of the urethane polymer solution B was 60% by weight.

Synthesis Example 3 Urethane Polymer Solution C
1 L round bottom separable flask, separable cover, separation funnel, thermometer, dry air inlet tube, Liebig cooler, vacuum seal, stir bar, stirring blade, polymerization experimental equipment equipped with polypropylene glycol (product name 150 g of "Sannix PP-2000", Sanyo Chemical Industries, Ltd. 150 g of a polymerizable carbon double bond-containing diol (product name "epoxy ester 3002 M (N), manufactured by Kyoeisha Chemical Co., Ltd.), toluene as a solvent (Tosoh Corp.) ), 0.2 g of dibutyltin dilaurate (IV) (manufactured by Wako Pure Chemical Industries, Ltd.) as a catalyst, and 3.8 g of an antioxidant (trade name “Irganox 1010, manufactured by BASF”) Dry air displacement was carried out at room temperature for 1 hour while stirring. Thereafter, 56 g of hexamethylene diisocyanate (trade name "HDI", manufactured by Tosoh Corp.) was added while stirring under a flow of dry air, and the temperature of the solution in the experimental apparatus was controlled to 65 ± 2 ° C. with a water bath. While holding for 8 hours, 15.3 g of a polymerizable carbon double bond-containing diol (product name “epoxy ester 3002M (N)” manufactured by Kyoeisha Chemical Co., Ltd.), a polymerizable carbon double bond-containing triol (product name “ 7.3 g of "Denacol Acrylate DA-314" (manufactured by Nagase ChemteX Corp.) was added, and after holding for 8 hours while controlling the temperature of the solution in the experimental apparatus to 65 ± 2 ° C. with a water bath, urethane Polymer solution C was obtained. The solid content concentration of the urethane polymer solution C was 60% by weight.

Synthesis Example 4 Urethane Polymer Solution D
1L round bottom separable flask, separable cover, separation funnel, thermometer, nitrogen introduction tube, Liebig cooler, vacuum seal, stirring bar, stirring rod, polymerization experimental equipment equipped with polytetramethylene ether glycol ( Add 200g of product name "PTMG850", manufactured by Mitsubishi Chemical Corporation, 100g of toluene (manufactured by Tosoh Corp.) as solvent, 0.122g of dibutyltin dilaurate (IV) (manufactured by Wako Pure Chemical Industries, Ltd.) as a catalyst While stirring, nitrogen substitution was carried out at room temperature for 1 hour. Thereafter, 44.5 g of hexamethylene diisocyanate (trade name "HDI", manufactured by Tosoh Corp.) was added while stirring under nitrogen inflow, and control was performed so that the solution temperature in the experimental apparatus became 90 ± 2 ° C with a water bath. Then, after holding for 4 hours, 3.6 g of glycerin (product name "glycerin", manufactured by Tokyo Chemical Industry Co., Ltd.) was added, and controlled by a water bath so that the temperature of the solution in the experimental apparatus became 90 ± 2 ° C. While holding for 2 hours, 14.1 g of hexamethylene diisocyanate (product name "HDI", manufactured by Tosoh Corporation) was added, and the temperature of the solution in the experimental apparatus was controlled to 90 ± 2 ° C with a water bath. After holding for 2 hours, a urethane polymer solution D was obtained. During the polymerization, toluene was dropped as appropriate in order to prevent temperature control during polymerization and a decrease in the stirring property due to the viscosity increase. The total amount of toluene dropped was 150 g. The solid content concentration of the urethane polymer solution D was 40% by weight.

Example 1
As shown in Table 1, the urethane polymer solution A obtained in Synthesis Example 1 was 100 parts by weight as polymer solid, and trimethylolpropane triacrylate as a compound having a bifunctional or higher functional polymerizable carbon-carbon double bond ( 50 parts by weight of TMPTA) (trade name "TMP3A", manufactured by Osaka Organic Chemical Industry Ltd.) and 7 parts by weight of an isocyanate crosslinking agent (trade name "Coronato HX", manufactured by Tosoh Corp.) and a photopolymerization initiator ( A pressure-sensitive adhesive composition (1) was obtained by mixing 1 part by weight of “IRGACURE 651” manufactured by BASF and 1 part by weight of a heat resistant stabilizer (trade name “IRGANOX 1010” manufactured by BASF) . The obtained pressure-sensitive adhesive composition (1) is applied to a substrate (trade name "T100-75S", thickness 75 μm, manufactured by Mitsubishi Resins Co., Ltd.) made of polyester resin so that the thickness after drying is 75 μm, and dried. It was cured and dried under conditions of a temperature of 130 ° C. and a drying time of 3 minutes. Thus, a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition (1) was produced on the substrate. Next, the surface of the obtained pressure-sensitive adhesive layer is a silicone-treated side of a release sheet (trade name "MRF25", thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin with a thickness of 25 μm, one side of which is siliconized. Were laminated to obtain a surface protective sheet (1). The obtained surface protection sheet (1) was subjected to aging for 7 days at normal temperature for evaluation. The release sheet was released immediately before the evaluation. The results are shown in Table 2.

Example 2
As shown in Table 1, a pressure-sensitive adhesive composition (2) was prepared in the same manner as in Example 1 except that the amount of the isocyanate-based crosslinking agent (trade name "Coronate HX", manufactured by Tosoh Corporation) was changed to 10 parts by weight. A pressure-sensitive adhesive layer comprising the above was produced to obtain a surface protective sheet (2). The results are shown in Table 2.

[Example 3]
As shown in Table 1, the urethane polymer solution A obtained in Synthesis Example 1 was 100 parts by weight as polymer solid, and a polyol having a bifunctional or higher polymerizable carbon-carbon double bond (epoxy ester, trade name “ 20 parts by weight of epoxy ester 200 PA, manufactured by Kyoeisha Chemical Co., Ltd., and 18 parts by weight of an isocyanate-based crosslinking agent (trade name "Coronate HX", manufactured by Tosoh Corp.), and a photopolymerization initiator (trade name "IRGACURE 651" And 1 part by weight of a heat-resistant stabilizer (trade name "IRGANOX 1010", manufactured by BASF) were mixed to obtain a pressure-sensitive adhesive composition (3). The obtained pressure-sensitive adhesive composition (3) is applied to a substrate (trade name "T100-75S", thickness 75 μm, manufactured by Mitsubishi Resins Co., Ltd.) made of polyester resin so that the thickness after drying is 75 μm, and dried. It was cured and dried under conditions of a temperature of 130 ° C. and a drying time of 3 minutes. Thus, a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition (3) was produced on the substrate. Next, the surface of the obtained pressure-sensitive adhesive layer is a silicone-treated side of a release sheet (trade name "MRF25", thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin with a thickness of 25 μm, one side of which is siliconized. Were laminated to obtain a surface protective sheet (3). The obtained surface protection sheet (3) was aged at normal temperature for 7 days and evaluated. The release sheet was released immediately before the evaluation. The results are shown in Table 2.

Example 4
As shown in Table 1, the amount of a polyol (epoxy ester, trade name "epoxy ester 200 PA" manufactured by Kyoeisha Chemical Co., Ltd.) having a bifunctional or higher polymerizable carbon-carbon double bond is changed to 30 parts by weight, A pressure-sensitive adhesive layer comprising a pressure-sensitive adhesive composition (4) was prepared in the same manner as in Example 3, except that the amount of the isocyanate-based crosslinking agent (trade name "Coronato HX", manufactured by Tosoh Corp.) was changed to 27 parts by weight. It produced and obtained surface protection sheet (4). The results are shown in Table 2.

[Example 5]
As shown in Table 1, 100 parts by weight of the solid content of the urethane polymer solution B obtained in Synthesis Example 2 and 5 parts by weight of an isocyanate crosslinking agent (trade name "Corronate HX", manufactured by Tosoh Corporation) 1 part by weight of a photopolymerization initiator (trade name “IRGACURE 651”, manufactured by BASF) and 1 part by weight of a heat stabilizer (trade name “IRGANOX 1010”, made by BASF), and I got 5). The obtained pressure-sensitive adhesive composition (5) is applied to a substrate (trade name "T100-75S", thickness 75 μm, manufactured by Mitsubishi Resins Co., Ltd.) made of polyester resin so that the thickness after drying is 75 μm, and dried. It was cured and dried under conditions of a temperature of 130 ° C. and a drying time of 3 minutes. Thus, a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition (5) was produced on the substrate. Next, the surface of the obtained pressure-sensitive adhesive layer is a silicone-treated side of a release sheet (trade name "MRF25", thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin with a thickness of 25 μm, one side of which is siliconized. Were laminated to obtain a surface protective sheet (5). The obtained surface protection sheet (5) was aged at normal temperature for 7 days and evaluated. The release sheet was released immediately before the evaluation. The results are shown in Table 2.

[Example 6]
As shown in Table 1, a pressure-sensitive adhesive composition was prepared in the same manner as in Example 5, except that the urethane polymer solution C obtained in Synthesis Example 3 was used instead of the urethane polymer solution B obtained in Synthesis Example 2. The adhesive layer which consists of (6) was produced, and surface protection sheet (6) was obtained. The results are shown in Table 2.

[Example 7]
As shown in Table 1, 100 parts by weight of the solid content of the urethane polymer solution D obtained in Synthesis Example 4 was used in place of the urethane polymer solution A, and a bifunctional or higher polymerizable carbon-carbon double bond was The amount of the polyol (epoxy ester, trade name "epoxy ester 200 PA" manufactured by Kyoeisha Chemical Co., Ltd.) is changed to 20 parts by weight, and the amount of isocyanate crosslinking agent (trade name "Corronate HX" manufactured by Tosoh Corp.) A pressure-sensitive adhesive layer comprising a pressure-sensitive adhesive composition (7) was produced in the same manner as in Example 3 except that the amount was changed to 15 parts by weight, to obtain a surface protective sheet (7). The results are shown in Table 2.

Comparative Example 1
As shown in Table 1, 100 parts by weight of the solid content of the urethane polymer solution A obtained in Synthesis Example 1 and 7 parts by weight of an isocyanate crosslinking agent (trade name "Corronate HX", manufactured by Tosoh Corporation) A heat resistant stabilizer (trade name "IRGANOX 1010", manufactured by BASF) was mixed with 1 part by weight to obtain a pressure-sensitive adhesive composition (C1). The obtained pressure-sensitive adhesive composition (C1) is applied to a substrate (trade name "T100-75S", thickness 75 μm, manufactured by Mitsubishi Resins Co., Ltd.) made of polyester resin so that the thickness after drying is 75 μm, and dried. It was cured and dried under conditions of a temperature of 130 ° C. and a drying time of 3 minutes. Thus, a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition (C1) was produced on the substrate. Next, the surface of the obtained pressure-sensitive adhesive layer is a silicone-treated side of a release sheet (trade name "MRF25", thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin with a thickness of 25 μm, one side of which is siliconized. Were laminated to obtain a surface protective sheet (C1). The obtained surface protection sheet (C1) was aged at normal temperature for 7 days and evaluated. The release sheet was released immediately before the evaluation. The results are shown in Table 2.

Comparative Example 2
100 parts by weight of an addition reaction type silicone adhesive (trade name "X-40-3306", manufactured by Shin-Etsu Chemical Co., Ltd.) and a platinum catalyst (trade name "CAT-PL-50T", manufactured by Shin-Etsu Chemical Co., Ltd. The mixture was mixed with 0.2 parts by weight of ethyl acetate and ethyl acetate was added so that the solid content of the solution after preparation was 35%, to obtain a silicone-based pressure-sensitive adhesive composition. The resulting silicone-based pressure-sensitive adhesive composition is applied to a substrate (trade name “T100-75S”, 75 μm thick, manufactured by Mitsubishi Resins Co., Ltd.) made of polyester resin so that the thickness after drying is 75 μm, and the drying temperature is It was cured and dried at 150 ° C. for 5 minutes. Thus, a pressure-sensitive adhesive layer composed of a silicone-based pressure-sensitive adhesive was produced on the substrate. Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated side of a release sheet (trade name "T100-25S", 25 μm thick, manufactured by Mitsubishi Chemical Corporation) made of polyester resin with a thickness of 25 μm is laminated on one surface. The surface protective film (C2) was obtained. The obtained surface protection film (C2) was aged at normal temperature for 7 days and evaluated. The release sheet was released immediately before the evaluation. The results are shown in Table 2.

Comparative Example 3
100 parts by weight of 2-ethylhexyl acrylate (manufactured by Nippon Shokubai Co., Ltd.) and 4-hydroxybutyl acrylate (Osaka Organic Chemical Industry Co., Ltd.) in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet pipe, and a cooler 10 parts by weight, 0.02 parts by weight of acrylic acid (made by Toagosei Co., Ltd.), 0.2 as 2,2'-azobisisobutyro nitrile (made by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator Charge in parts by weight and 192 parts by weight of ethyl acetate, introduce nitrogen gas while gently stirring, keep the liquid temperature in the flask at around 60 ° C, carry out polymerization reaction for 8 hours, and add acrylic polymer solution ( A solid content of 36% by weight was prepared. The solution of the obtained acrylic polymer is crosslinked with 8 parts by weight of an isocyanate crosslinking agent (trade name "Corronate HX", manufactured by Tosoh Corp.) in solid content conversion with respect to 100 parts by weight of the solid content of the acrylic polymer Add 0.02 parts by weight of dibutyltin dilaurate (made by Tokyo Fine Chemical Co., Ltd.) as a catalyst in terms of solid content, add ethyl acetate so that the solid content of the solution after preparation is 25%, mix and stir, and apply acrylic adhesive An agent composition was prepared. The resulting acrylic pressure-sensitive adhesive composition is applied to one surface of a base material (trade name "T100-75S", thickness 75 μm, manufactured by Mitsubishi Resins Co., Ltd.) made of polyester resin, and the thickness after drying is 75 μm. It applied so that it might become, and it cured and dried on conditions with a drying temperature of 130 degreeC, and 3 minutes of drying time. Thus, on the substrate, a pressure-sensitive adhesive layer made of an acrylic pressure-sensitive adhesive was produced. Then, a release sheet (trade name “Diafoil MRF-38”, 38 μm thick, manufactured by Mitsubishi Resins Co., Ltd., made of 38 μm thick polyester resin, one side of which is silicone-treated on the surface of the obtained pressure-sensitive adhesive layer) The silicone-treated side of the above was laminated to obtain a surface protective sheet (C3). The obtained surface protection sheet (C3) was aged at normal temperature for 7 days and evaluated. The release sheet was released immediately before the evaluation. The results are shown in Table 2.

The surface protection sheet for optical members of the present invention can be suitably used for surface protection of optical members (for example, display members).

100 Surface Protective Sheet 10 for Optical Member Base Film 20a Adhesive Layer 20b Adhesive Layer

Claims

It is a surface protection sheet for optical members which has a substrate film and an adhesive layer provided on at least one of the outermost layers,
Adhesion is reduced by irradiation with active energy rays,
Surface protection sheet for optical members.
The adhesive strength (A) of the surface protection sheet for optical members is 32 mN / 10 mm or more,
The adhesive force (B) after ultraviolet irradiation of the surface protective sheet for an optical member is 24 mN / 10 mm or less,
The adhesion (A) is at least twice the adhesion (B) after the ultraviolet irradiation,
The adhesive force (C) after low pressure application of the surface protective sheet for an optical member is 0.8 times or more of the adhesive force (A),
The residual adhesive strength (D) after ultraviolet irradiation of the surface protective sheet for an optical member is at least 0.8 times the initial residual adhesive strength (E),
The surface protection sheet for optical members according to claim 1.
However, the measurement method of adhesive strength (A), adhesive strength after ultraviolet irradiation (B), adhesive strength after low pressure sticking (C), residual adhesion after ultraviolet irradiation (D), initial residual adhesion (E) is as follows It is street.
Adhesive force (A): Measurement is performed according to JIS Z0237: 2009 in an environment of temperature 23 ± 1 ° C. and humidity 50 ± 5% RH. The test plate is a SUS304BA plate, and the washing solvent for the test plate uses methyl ethyl ketone. The measurement of the peel adhesion strength in Section 10.4 of JIS Z0237: 2009 is carried out according to Method 1 in Section 10.4.1 of JIS Z0237: 2009.
Adhesiveness after ultraviolet irradiation (B): Measurement is carried out according to JIS Z0237: 2009 in an environment of temperature 23 ± 1 ° C. and humidity 50 ± 5% RH. However, ultraviolet light irradiation (high pressure mercury lamp, 200 mW / cm 2 , 440 mJ / cm 2 ) is performed within 1 minute after sticking the surface protection sheet for optical members to the test plate, and peeling within 10 minutes after the ultraviolet light irradiation Measure the adhesion. The test plate is a SUS304BA plate, and the washing solvent for the test plate uses methyl ethyl ketone. The measurement of the peel adhesion strength in Section 10.4 of JIS Z0237: 2009 is carried out according to Method 1 in Section 10.4.1 of JIS Z0237: 2009.
Adhesive force after low pressure adhesion (C): Measured according to JIS Z0237: 2009 in an environment of temperature 23 ± 1 ° C. and humidity 50 ± 5% RH. However, instead of using a 2 kg pressure roller, a 200 g pressure roller is used, and instead of performing pressure bonding with a pressure roller by a total of 2 reciprocations at a speed of 10 ± 0.5 mm / s, one direction is performed at 100 ± 5 mm / s. Crimp only once and measure adhesion. The test plate is a SUS304BA plate, and the washing solvent for the test plate uses methyl ethyl ketone. The measurement of the peel adhesion strength in Section 10.4 of JIS Z0237: 2009 is carried out according to Method 1 in Section 10.4.1 of JIS Z0237: 2009.
Residual adhesion after ultraviolet irradiation (D): First, in an environment at a temperature of 23 ± 1 ° C. and a humidity of 50 ± 5% RH, a test of the surface protection sheet for optical members according to the method of measuring the adhesion after ultraviolet irradiation (B) Peel off the board. However, peeling from the test plate of the surface protection sheet for optical members is performed one day after it is attached. Next, in a environment with a temperature of 23 ± 1 ° C and a humidity of 50 ± 5% RH, pull the adhesive tape (product name: No. 31B made by Nitto Denko Corporation) and cut the surface protection sheet for optical members. It is stuck on the surface of the peeled test plate and left for 30 minutes, and peeled off at a peeling angle of 180 ° and a peeling speed of 300 ± 12 mm / min, and the residual adhesive strength (D) after ultraviolet irradiation is measured.
Initial residual adhesion (E): A pressure-sensitive adhesive tape (product name: No. 31B, manufactured by Nitto Denko Corporation, product name: No. 31B) cut to a width of 19 mm in an environment of temperature 23 ± 1 ° C. and humidity 50 ± 5% RH After sticking to the surface and leaving for 30 minutes, peel at a peel angle of 180 ° and a peel speed of 300 ± 12 mm / min, and measure the initial residual adhesion (E).
The surface protection sheet for an optical member according to claim 1, wherein the pressure-sensitive adhesive layer contains a photopolymerization initiator that generates a radical by ultraviolet irradiation.
The surface protection sheet for optical members in any one of Claim 1 to 3 whose 30 weight% or more of the said adhesive layer is polyurethane-type resin.
The surface protective sheet for an optical member according to any one of claims 1 to 4, wherein the pressure-sensitive adhesive layer contains a polymerizable carbon-carbon double bond.
The surface protective sheet for an optical member according to claim 5, wherein the polymerizable carbon-carbon double bond is a polymerizable carbon-carbon double bond possessed by at least one group selected from an acryloyl group and a methacryloyl group.
The surface protective sheet for an optical member according to claim 5 or 6, wherein the pressure-sensitive adhesive layer contains a compound having a polymerizable carbon-carbon double bond.
The surface protective sheet for an optical member according to claim 7, wherein the pressure-sensitive adhesive layer contains a polyurethane-based resin, a compound having a bifunctional or more polymerizable carbon-carbon double bond, and an isocyanate-based crosslinking agent.
The surface protection sheet for an optical member according to claim 7, wherein the compound having a polymerizable carbon-carbon double bond is a polyol having a polymerizable carbon-carbon double bond.
The polyurethane resin is obtained by polymerizing a monomer composition containing a polyisocyanate and a monomer having at least two functional groups capable of reacting with isocyanate groups, and at least at least the functional groups capable of reacting with the polyisocyanate and the isocyanate groups. The surface protective sheet for an optical member according to claim 4, wherein at least one selected from the two monomers having at least one monomer has a polymerizable carbon-carbon double bond.
The surface protection sheet for an optical member according to claim 10, wherein the monomer having at least two functional groups capable of reacting with the isocyanate group is a polyol having a bifunctional or higher functional polymerizable carbon-carbon double bond.