Surface protective film

Abstract

Provided is a surface protective film including an adhesive layer, the surface protective film being capable of exhibiting excellent antistatic performance, excellent high-temperature low-speed adhesive force, and low haze at the same time. A surface protective film according to an embodiment of the present invention comprises an adhesive layer comprising a urethane-based adhesive comprising a urethane polymer, the urethane-based adhesive being formed from a urethane-based adhesive composition, the urethane-based adhesive composition contains a base polymer (A), a silicone-based compound (B), and an ionic compound (C), the fluorine content in the adhesive layer is 0.15 wt% or less, and the surface free energy of the surface of the adhesive layer with respect to diiodomethane is 2.5 mJ / m2 to 20.0 mJ / m2.

Description

Technical Field

[0001] This invention relates to surface protective films. Background Technology

[0002] In the manufacturing process of optical and electronic components, to prevent surface scratches during processing, assembly, inspection, and transportation, a surface protective film is usually applied to the exposed surface of the optical or electronic component. This surface protective film is then peeled off from the optical or electronic component at a point when surface protection is no longer required (Patent Document 1).

[0003] Surface protective films, optical components, and electronic components have high electrical insulation properties, and static electricity can be generated due to friction and peeling. Therefore, when the surface protective film is peeled off from optical or electronic components with the film attached, static electricity is easily generated. In the state of residual static electricity, for example, when voltage is applied to the liquid crystal, the alignment of liquid crystal molecules may be lost or panel defects may occur. In addition, the presence of static electricity can become a major cause of attracting dust or reducing workability.

[0004] To prevent the generation of static electricity as described above, techniques for performing antistatic treatment on surface protective films have been reported. For example, techniques have been reported in which the adhesive layer of the surface protective film contains ionic compounds such as alkali metal salts and ionic liquids that function as antistatic agents (Patent Document 2).

[0005] However, if the adhesive layer contains an antistatic agent, when other components are attached to the peeled surface of the adhesive after the protective film is peeled off from the adhesive, especially in a high-temperature atmosphere, there is a problem that the components may peel off from the adhesive, resulting in process defects.

[0006] Furthermore, if the adhesive layer contains an antistatic agent, the haze value of the surface protective film may sometimes increase. Increased haze value leads to reduced quality and less inspectability of the surface protective film.

[0007] Existing technical documents Patent documents Patent Document 1: Japanese Patent No. 6613516 Patent Document 2: Japanese Patent No. 6896927 Summary of the Invention

[0008] The problem that the invention aims to solve The technical problem of this invention is to provide a surface protective film comprising an adhesive layer, wherein the surface protective film can simultaneously exhibit excellent antistatic properties, excellent high-temperature low-speed adhesion, and low haze. Here, in the description of this invention, high-temperature low-speed adhesion refers to an indicator of the degree to which peeling of a surface protective film adhered to an adhesive surface is suppressed from the adhesive surface under high-temperature conditions, provided that the surface protective film is peeled off the adhesive surface and another component is adhered to the peeled surface of the adhesive surface. Higher high-temperature low-speed adhesion results in greater suppression of peeling.

[0009] Solution for solving the problem [1] The surface protective film of an embodiment of the present invention comprises an adhesive layer made of a urethane-based adhesive, the urethane-based adhesive comprising a urethane polymer, the urethane-based adhesive being formed from a urethane-based adhesive composition comprising a base polymer (A), an organosilicon compound (B), and an ionic compound (C), the fluorine content in the adhesive layer being less than 0.15% by weight, and the surface free energy of the adhesive layer surface against diiodomethane being 2.5 mJ / m 2 ~20.0mJ / m 2 .

[0010] [2] Alternatively, according to the surface protective film described in [1] above, the content of the ionic compound (C) relative to 100 parts by weight of the base polymer (A) is 0.01 parts by weight to 2.80 parts by weight.

[0011] [3] Alternatively, according to the surface protective film described in [1] or [2] above, wherein the urethane polymer (A) is a prepolymer type urethane polymer, after the adhesive layer is pasted onto the glass plate and placed at an ambient temperature of 23°C for 30 minutes, the average peel force when the surface protective film is peeled from the glass plate at a peel angle of 180 degrees and a peel speed of 300 mm / min is defined as the adhesive force (I), after the adhesive layer is pasted onto the glass plate and placed at an ambient temperature of 50°C for 1 day, the average peel force when the surface protective film is peeled from the glass plate at a peel angle of 180 degrees and a peel speed of 300 mm / min is defined as the adhesive force (II), at this time, the rate of increase of the adhesive force to the glass plate over time, defined by [adhesive force (II) / adhesive force (I)] × 100 (%), is less than 210%.

[0012] [4] Alternatively, according to the surface protective film described in [1] or [2] above, wherein the urethane polymer (A) is a one-step urethane polymer, after the adhesive layer is pasted onto the glass plate and placed at an ambient temperature of 23°C for 30 minutes, the average peel force when the surface protective film is peeled from the glass plate at a peel angle of 180 degrees and a peel speed of 300 mm / min is defined as the adhesive force (I), after the adhesive layer is pasted onto the glass plate and placed at an ambient temperature of 50°C for 1 day, the average peel force when the surface protective film is peeled from the glass plate at a peel angle of 180 degrees and a peel speed of 300 mm / min is defined as the adhesive force (II), at which time the rate of increase of the adhesive force to the glass plate over time, defined by [adhesive force (II) / adhesive force (I)] × 100 (%), is less than 160%.

[0013] [5] Alternatively, it may be a surface protective film according to any one of [1] to [4] above, wherein the organosilicon compound (B) comprises an organosilicon compound having a polyether structure.

[0014] [6] Alternatively, according to the surface protective film described in [5] above, the organosilicon compound having a polyether structure is at least one selected from the group consisting of reactive silicone oil and non-reactive silicone oil with an HLB value of 15 or less.

[0015] [7] The optical components of the embodiments of the present invention include a surface protective film as described in any one of [1] to [6] above.

[0016] [8] The electronic components of the embodiments of the present invention include a surface protective film as described in any one of [1] to [6] above.

[0017] Invention Effects According to the present invention, a surface protective film is provided, comprising an adhesive layer, wherein the surface protective film can simultaneously exhibit excellent antistatic properties, excellent high-temperature and low-speed adhesion, and low haze. Attached Figure Description

[0018] Figure 1 This is a schematic cross-sectional view of a surface protective film according to one embodiment of the present invention. Detailed Implementation

[0019] In the presence of the term "weight" in this specification, it may also be replaced with "mass," which is the SI unit commonly used to express weight.

[0020] In this specification, the expression "(meth)acrylic acid" refers to "acrylic acid and / or methacrylic acid", the expression "(meth)acrylate" refers to "acrylate and / or methacrylate", the expression "(meth)allyl" refers to "allyl and / or methylallyl", and the expression "(meth)acrylaldehyde" refers to "acrylaldehyde and / or methacrolein".

[0021] 《A. Surface Protective Film》 The surface protective film of embodiments of the present invention includes an adhesive layer composed of a urethane-based adhesive. In the surface protective film of embodiments of the present invention, the urethane-based adhesive comprises a urethane polymer.

[0022] In the surface protective film of the embodiments of the present invention, the urethane adhesive is formed from a urethane adhesive composition comprising a base polymer (A), an organosilicon compound (B), and an ionic compound (C).

[0023] In the surface protective film of the embodiments of the present invention, the total content of the base polymer (A), organosilicon compound (B) and ionic compound (C) in the urethane adhesive composition is preferably 50% to 100% by weight, more preferably 70% to 99% by weight, further preferably 80% to 98% by weight, and particularly preferably 90% to 97% by weight in terms of solid content.

[0024] In the surface protective film of the embodiments of the present invention, the content of the base polymer (A) in the urethane adhesive composition, converted to solids, is preferably 60% to 99.9% by weight, more preferably 70% to 99% by weight, further preferably 80% to 98% by weight, and particularly preferably 90% to 97% by weight. If the content of the base polymer (A) in the urethane adhesive composition, converted to solids, is within the above range, the effects of the present invention can be further demonstrated.

[0025] The surface protective film of embodiments of the present invention may include any suitable other components without impairing the effects of the present invention, as long as it comprises an adhesive layer made of a urethane-based adhesive. For example, the surface protective film of embodiments of the present invention comprises a substrate and the aforementioned adhesive layer. Furthermore, as described later, any suitable release liner (sometimes also called a release sheet or diaphragm) may be provided on the surface of the adhesive layer opposite to the substrate for protection before use, etc.

[0026] Figure 1This is a schematic cross-sectional view of a surface protective film according to one embodiment of the present invention. Figure 1 In this process, the surface protective film 10 comprises a substrate 1 and an adhesive layer 2. Figure 1 In this process, substrate 1 and adhesive layer 2 are directly laminated.

[0027] exist Figure 1 In this adhesive layer 2, on the surface opposite to the substrate 1, an arbitrary and suitable release liner (sometimes called a release sheet or diaphragm) (not shown) may be provided for protection before use. Examples of release liners include: release liners whose surfaces (liner substrates) such as paper or plastic film are treated with silicone; and release liners whose surfaces (liner substrates) are laminated with polyolefin resin.

[0028] Examples of plastic films used as liner substrates include: polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, ethylene-vinyl acetate copolymer film, etc.

[0029] The thickness of the release liner is preferably 1 μm to 500 μm, more preferably 3 μm to 450 μm, even more preferably 5 μm to 400 μm, and particularly preferably 10 μm to 300 μm.

[0030] The thickness of the surface protective film in embodiments of the present invention can be any suitable thickness without impairing the effects of the present invention. Preferably, the thickness is 5 μm to 500 μm, more preferably 10 μm to 450 μm, even more preferably 15 μm to 400 μm, and particularly preferably 20 μm to 300 μm.

[0031] Regarding the surface protective film of embodiments of the present invention, the fluorine content in the adhesive layer is preferably less than 0.15% by weight, more preferably 0% to 0.10% by weight, further preferably 0% to 0.05% by weight, and particularly preferably 0% to 0.02% by weight. The surface protective film of embodiments of the present invention, by comprising an adhesive layer made of a urethane-based adhesive as described above, wherein the urethane-based adhesive is formed from a urethane-based adhesive composition comprising a urethane polymer (A), an organosilicon compound (B), and an ionic compound (C), and by adjusting the fluorine content in the adhesive layer to the aforementioned range, can provide a surface protective film that simultaneously exhibits excellent antistatic properties, excellent high-temperature, low-speed adhesion, and low haze. If the fluorine content in the adhesive layer is too high, for example, it may be difficult to exhibit excellent high-temperature, low-speed adhesion, and when the surface protective film adhered to the substrate is peeled off from the substrate, and other components are adhered to the peeled surface of the substrate and exposed to high-temperature conditions, the components may easily peel off from the substrate. It should be noted that the details of the method for determining the fluorine content in the adhesive layer will be described later.

[0032] For the surface protective film according to embodiments of the present invention, the surface free energy of the adhesive layer surface against diiodomethane is preferably 2.5 mJ / m. 2 ~20.0mJ / m 2 More preferably 3.0 mJ / m 2 ~18.0mJ / m 2 More preferably 3.3 mJ / m 2 ~16.0mJ / m 2 The preferred value is 3.5 mJ / m 2 ~15.0mJ / m 2The surface protective film of the present invention comprises, as described above, an adhesive layer made of a urethane-based adhesive, which is formed from a urethane-based adhesive composition containing a urethane polymer (A), an organosilicon compound (B), and an ionic compound (C). By adjusting the surface free energy of the adhesive layer surface relative to diiodomethane to the aforementioned range, a surface protective film that simultaneously exhibits excellent antistatic properties, excellent high-temperature, low-speed adhesion, and low haze can be provided. If the surface free energy of the adhesive layer surface relative to diiodomethane is too small, the adhesive force of the adhesive layer (e.g., the adhesive force (I) described in this specification) may become too high, making the surface protective film difficult to peel off. If the surface free energy of the adhesive layer surface relative to diiodomethane is too large, the haze may increase. It should be noted that details of the method for measuring the surface free energy of the adhesive layer surface relative to diiodomethane will be described later.

[0033] Regarding the surface protective film of the embodiments of the present invention, after the surface protective film is adhered to a glass plate and left for one day at an environment of 23°C and 50% RH, the peeling electrostatic voltage (peeling electrostatic voltage to the glass plate) on the glass plate surface when the surface protective film is peeled off from the glass plate at a peeling angle of 150 degrees and a peeling speed of 15 m / min is preferably 7.5 kV or less, more preferably 0 kV to 6.5 kV, further preferably 0 kV to 5.5 kV, further preferably 0 kV to 4.5 kV, further preferably 0 kV to 3.5 kV, further preferably 0 kV to 3.0 kV, further preferably 0 kV to 2.5 kV, particularly preferably 0 kV to 2.0 kV, and most preferably 0 kV to 1.5 kV. If the above-mentioned peeling electrostatic voltage to the glass plate is within the above range, a surface protective film exhibiting excellent antistatic properties can be provided. If the electrostatic voltage for peeling the glass plate deviates excessively from the aforementioned range, static electricity may be easily generated when peeling the protective film from optical or electronic components to which the protective film is adhered. It should be noted that details of the method for measuring the electrostatic voltage for peeling the glass plate will be described later.

[0034] Regarding the surface protective film in the embodiments of the present invention, after the adhesive layer is adhered to the glass plate and placed at an ambient temperature of 23°C for 1 day, the surface protective film is peeled off from the glass plate. After applying No. 31B tape (manufactured by Nitto Denko Corporation) to the peeled surface of the glass plate, the high-temperature, low-speed adhesion strength of No. 31B to the glass plate when peeled at 85°C with a peel angle of 180 degrees and a peel speed of 10 mm / min is preferably 1.5 gf / 25 mm or more, more preferably 2.0 gf / 25 mm or more, further preferably 2.5 gf / 25 mm or more, particularly preferably 2.8 gf / 25 mm or more, and most preferably 3.0 gf / 25 mm or more. Regarding the above-mentioned high-temperature, low-speed adhesion strength of No. 31B to the glass plate, the lower the contamination of the glass plate after peeling off the surface protective film, the more firmly the No. 31B tape (manufactured by Nitto Denko Corporation) is adhered. Therefore, the greater the high-temperature, low-speed adhesion strength of No. 31B to the glass plate, the better, and there is no upper limit. The high-temperature, low-speed adhesive force of glass plate No. 31B described above refers to the high-temperature, low-speed adhesive force in this invention. If the high-temperature, low-speed adhesive force of glass plate No. 31B is within the above range, even if the protective film adhering to the adhered object is peeled off from the adhered object and other components are attached to the peeled surface of the adhered object and exposed to high-temperature conditions, the peeling of the components from the adhered object can be sufficiently suppressed. If the high-temperature, low-speed adhesive force of glass plate No. 31B is too small, for example, when the protective film adhering to the adhered object is peeled off from the adhered object and other components are attached to the peeled surface of the adhered object and exposed to high-temperature conditions, the components may easily peel off from the adhered object. It should be noted that the details of the method for measuring the high-temperature, low-speed adhesive force of glass plate No. 31B will be described later.

[0035] Regarding the surface protective film in embodiments of the present invention, its haze is preferably 6.0% or less, more preferably 5.0% or less, further preferably 4.0% or less, even more preferably 3.0% or less, even more preferably 2.0% or less, particularly preferably 1.5% or less, and most preferably 1.0% or less. The lower limit of the above haze is preferably 0% or more. If the haze is within the above range, the transparency of the surface protective film is high, for example, allowing for accurate inspection when the surface protective film is adhered to the surface of an object such as an optical component or electronic component. If the haze deviates excessively from the above range, for example, the transparency of the surface protective film may decrease, and for example, the inspection described above may be hindered. It should be noted that details of the haze measurement method will be described later.

[0036] Regarding the surface protective film according to embodiments of the present invention, after the adhesive layer is adhered to a glass plate and placed at an ambient temperature of 23°C for 30 minutes, the average peel force, i.e., the adhesive force (I), when the surface protective film is peeled from the glass plate at a peel angle of 180 degrees and a peel speed of 300 mm / min is preferably 5.0 gf / 25 mm or less, more preferably 4.0 gf / 25 mm or less, further preferably 3.5 gf / 25 mm or less, even more preferably 3.0 gf / 25 mm or less, particularly preferably 2.5 gf / 25 mm or less, and most preferably 2.0 gf / 25 mm or less. From the viewpoint of being able to function appropriately as a surface protective film, practically speaking, the lower limit value of the above-mentioned adhesive force (I) is preferably 0.3 gf / 25 mm or more. If the above-mentioned adhesive force (I) is within the above range, a surface protective film that moderately adheres to the adhered object and is easy to peel off can be provided. If the above-mentioned adhesive force (I) deviates from the above range and is too large, it may become, for example, a surface protective film with excessively high adhesion to the adhered object, making it difficult to peel off. It should be noted that the details of the above-mentioned method for measuring adhesive force (I) will be described later.

[0037] Regarding the surface protective film of the embodiments of the present invention, after the adhesive layer is adhered to a glass plate and placed at an ambient temperature of 50°C for 1 day, the average peel force when the surface protective film is peeled from the glass plate at a peel angle of 180 degrees and a peel speed of 300 mm / min is defined as the adhesive force (II). The increase in adhesive force compared to the adhesive force (I) over time, defined as [adhesive force (II) / adhesive force (I)] × 100 (%), is preferably less than 210%, more preferably 200% or less, further preferably 190% or less, further preferably 180% or less, further preferably 170% or less, further preferably 160% or less, particularly preferably 150% or less, and most preferably 140% or less. The lower limit of the above-mentioned increase in adhesive force over time is preferably 100% or more. If the above-mentioned increase in adhesive force over time is within the above range, a surface protective film can be provided where the increase in adhesive force to the adhered object over time is suppressed, and the film maintains moderate adhesion and is easy to peel off even after a period of time after being adhered to the adhered object. If the rate of increase in the adhesive force on the glass plate over time deviates excessively from the aforementioned range, the adhesive force on the adherend may increase over time, and after a period of time following adhesion, the bond may become so strong that it becomes difficult to peel off. It should be noted that details of the method for measuring the adhesive force (II) will be described later.

[0038] When the urethane polymer contained in the urethane-based adhesive constituting the adhesive layer is a prepolymer-type urethane polymer, the aforementioned rate of increase in adhesion force to the glass plate over time is preferably less than 210%, more preferably less than 190%, further preferably less than 170%, further preferably less than 160%, further preferably less than 150%, further preferably less than 140%, particularly preferably less than 135%, and most preferably less than 130%. The lower limit of the aforementioned rate of increase in adhesion force to the glass plate over time is preferably 100% or more.

[0039] When the urethane polymer contained in the urethane-based adhesive constituting the adhesive layer is a one-step urethane polymer, the aforementioned rate of increase in adhesion force to the glass plate over time is preferably less than 210%, more preferably less than 170%, further preferably less than 150%, more preferably less than 140%, more preferably less than 130%, particularly preferably less than 120%, and most preferably less than 115%. The lower limit of the aforementioned rate of increase in adhesion force to the glass plate over time is preferably 100% or more.

[0040] The surface protective film of the embodiments of the present invention can be manufactured by any suitable method. For example, it can be manufactured according to any suitable method, such as the following method.

[0041] (1) A method of applying a solution or hot melt liquid of an adhesive layer forming material onto a substrate.

[0042] (2) A method of applying a solution or hot melt of the adhesive layer forming material to a release liner and transferring the formed adhesive layer to a substrate.

[0043] (3) A method of extruding the adhesive layer forming material onto the substrate to form a coating.

[0044] (4) A method of extruding the substrate and adhesive layer in a double or multi-layer manner.

[0045] (5) A method of laminating an adhesive layer onto a substrate in a single layer or a method of laminating an adhesive layer and a laminate together onto a substrate in a double layer.

[0046] (6) A method for double-layer or multi-layer lamination of substrate forming materials such as adhesive layers, films, and laminates.

[0047] It should be noted that any suitable method can be used as described above for coating. Examples of such coating methods include: roller coating, comma coating, die coating, reverse coating, screen printing, gravure coating, etc.

[0048] A-1. Adhesive Layer The adhesive layer is composed of a urethane-based adhesive. The urethane-based adhesive is formed from a urethane-based adhesive composition. That is, the adhesive layer is composed of a urethane-based adhesive, which is formed from a urethane-based adhesive composition. For example, the urethane-based adhesive, formed from a urethane-based adhesive composition, constitutes a layer shape, thus becoming an adhesive layer.

[0049] The adhesive layer can be formed by any suitable method. One such method is, for example, applying a urethane-based adhesive composition to any suitable substrate, heating / drying as needed, and curing it as needed to form an adhesive layer on the substrate. The application method, heating / drying conditions, curing conditions, etc., can be suitably adopted from methods commonly known for forming adhesive layers.

[0050] The thickness of the adhesive layer can be appropriately set according to the purpose of the invention without impairing its effects. The thickness of the adhesive layer is typically 5 μm to 150 μm.

[0051] When the urethane polymer contained in the urethane-based adhesive is a prepolymer-type urethane polymer described later, the thickness of the adhesive layer is typically 5 μm to 150 μm, preferably 10 μm to 120 μm, more preferably 20 μm to 110 μm, even more preferably 30 μm to 100 μm, and particularly preferably 40 μm to 90 μm.

[0052] When the urethane polymer contained in the urethane-based adhesive is a one-step urethane polymer as described later, the thickness of the adhesive layer is typically 5 μm to 150 μm, preferably 7 μm to 100 μm, more preferably 10 μm to 50 μm, even more preferably 13 μm to 40 μm, and particularly preferably 15 μm to 30 μm.

[0053] In the surface protective film of embodiments of the present invention, the urethane-based adhesive comprises a urethane polymer. The urethane polymer in the urethane-based adhesive may be only one type, or it may be two or more types.

[0054] In the surface protective film of the embodiments of the present invention, the content of urethane polymer in the urethane-based adhesive, converted from solid components, is preferably 60% to 99.9% by weight, more preferably 70% to 99.9% by weight, further preferably 80% to 99.9% by weight, particularly preferably 85% to 99.9% by weight, and most preferably 90% to 99.9% by weight. If the content of urethane polymer in the urethane-based adhesive, converted from solid components, falls within the above range, the effects of the present invention can be further demonstrated.

[0055] As urethane polymers, "prepolymer-type urethane polymers" are generally known, which are produced by reacting urethane prepolymers with polyfunctional isocyanate compounds, and "one-step urethane polymers" are produced by directly reacting polyols with polyfunctional isocyanate compounds without using urethane prepolymers. A urethane prepolymer, in particular, is obtained by reacting a polyol with an excess of a polyfunctional isocyanate compound and has isocyanate groups at the molecule's ends.

[0056] Therefore, in the surface protective film of the embodiments of the present invention, the urethane polymer contained in the urethane-based adhesive is, in particular, at least one selected from the group consisting of prepolymer urethane polymers and one-step urethane polymers. The prepolymer urethane polymer may be only one type or may be two or more types. The one-step urethane polymer may be only one type or may be two or more types.

[0057] Here, the prepolymer type urethane polymer is obtained by reacting a urethane prepolymer (A), which is contained in the urethane-based adhesive composition, with a polyfunctional isocyanate compound. Therefore, when the urethane polymer is a prepolymer type urethane polymer, the urethane-based adhesive composition forming the urethane-based adhesive typically includes a urethane prepolymer (A), a polyfunctional isocyanate compound, an organosilicon compound (B), and an ionic compound (C). It should be noted that, for the prepolymer type urethane polymer, any suitable method can be used in the reaction of the urethane prepolymer (A) with the polyfunctional isocyanate compound without impairing the effects of the present invention.

[0058] Similarly, a one-step urethane polymer is obtained by reacting a polyol (not a urethane prepolymer) that serves as the base polymer (A) in a urethane-based adhesive composition with a polyfunctional isocyanate compound. Therefore, when the urethane polymer is a one-step urethane polymer, the urethane-based adhesive composition forming the urethane-based adhesive typically includes a polyol (not a urethane prepolymer) as the base polymer (A), a polyfunctional isocyanate compound, an organosilicon compound (B), and an ionic compound (C). It should be noted that, for a one-step urethane polymer, any suitable method can be used to prepare it without impairing the effects of the present invention, as long as the method employed in the reaction of the polyol as the base polymer (A) with the urethane of the polyfunctional isocyanate compound.

[0059] <A-1-1. Carbamate prepolymers as the base polymer (A)> The urethane prepolymers (A) that form the base polymer can react with polyfunctional isocyanate compounds to form prepolymer-type urethane polymers.

[0060] The urethane prepolymer can be one type or two or more types.

[0061] The urethane prepolymer is preferably a polyurethane polyol, more preferably obtained by reacting the polyol with a polyfunctional isocyanate compound. The number-average molecular weight Mn of the urethane prepolymer is, for example, 3,000 to 1,000,000.

[0062] The polyol comprises at least one selected from the group consisting of polyester polyols and polyether polyols. Specifically, the polyol consists of at least one selected from the group consisting of polyester polyols and polyether polyols. Polyester polyols may be only one type or may consist of two or more types. Polyether polyols may be only one type or may consist of two or more types.

[0063] As the polyester polyol, a polyester polyol commonly used in the preparation of urethane prepolymers can be appropriately used. Examples of such polyester polyols include those obtained by reacting an acidic component with a diol component. Examples of acidic components include: terephthalic acid, adipic acid, azelaic acid, sebacic acid, phthalic anhydride, isophthalic acid, and trimellitic acid. Examples of diol components include: ethylene glycol, propylene glycol, diethylene glycol, butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 3,3'-dimethylolheptane, polyoxyethylene glycol, polyoxypropylene glycol, 1,4-butanediol, neopentanediol, butylethylpentanediol, glycerol, trimethylolpropane, and pentaerythritol. Other examples of polyester polyols include those obtained by ring-opening polymerization of lactones such as polycaprolactone, poly(β-methyl-γ-valerol), and polyvalerol.

[0064] The molecular weight of the polyester polyol can range from low to high. The number average molecular weight Mn of the polyester polyol is, for example, 100 to 100,000, preferably 100 to 10,000.

[0065] As the polyether polyol, a polyether polyol commonly used in the preparation of urethane prepolymers can be appropriately used. Examples of such polyether polyols include, for instance, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and other polyether polyols containing two or more functional groups; more specifically, polyether polyols containing at least one group selected from the group consisting of methylene and methine groups can be included. A portion of the polyether polyol can be replaced with diols such as ethylene glycol, polyamines such as ethylenediamine, etc., as needed.

[0066] The molecular weight of the polyether polyol can range from low to high. The number average molecular weight Mn of the polyether polyol is, for example, 100 to 100,000, preferably 100 to 10,000.

[0067] One embodiment of the polyol is embodiment (A), which includes both polyester polyol and polyether polyol. In embodiment (A), the polyol is typically composed of both polyester polyol and polyether polyol.

[0068] In embodiment (A), the proportion of polyester polyol in the polyol is preferably 0.1% to 99.9% by weight, more preferably 0.1% to 80% by weight, further preferably 0.2% to 60% by weight, even more preferably 0.2% to 40% by weight, particularly preferably 0.3% to 30% by weight, and most preferably 0.3% to 20% by weight.

[0069] In embodiment (A), the polyether polyol content in the polyol is preferably 0.1% to 99.9% by weight, more preferably 20% to 99.9% by weight, further preferably 40% to 99.8% by weight, even more preferably 60% to 99.8% by weight, particularly preferably 70% to 99.7% by weight, and most preferably 80% to 99.7% by weight.

[0070] In embodiment (A), the polyether polyol is, for example, a polyether polyol containing at least two groups selected from the group consisting of methylene and methine. For instance, it may be a polyether polyol containing only two groups selected from the group consisting of methylene and methine, or it may be composed of a polyether polyol containing at least two groups selected from the group consisting of methylene and methine and a polyether polyol containing at least three groups selected from the group consisting of methylene and methine. Examples of polyether polyols containing at least two groups selected from the group consisting of methylene and methine include polyethylene glycol and polypropylene glycol. Examples of polyether polyols containing at least three groups selected from the group consisting of methylene and methine include polytetramethylene glycol.

[0071] Another embodiment of the polyol is embodiment (B), which contains a polyether polyol but does not contain a polyester polyol. In embodiment (B), the polyol is, in particular, composed of a polyether polyol.

[0072] In embodiment (B), the polyether polyol is, for example, a polyether polyol containing at least two groups selected from the group consisting of methylene and methine. For instance, it may be a polyether polyol containing only two groups selected from the group consisting of methylene and methine, or it may be composed of a polyether polyol containing at least two groups selected from the group consisting of methylene and methine and a polyether polyol containing at least three groups selected from the group consisting of methylene and methine. Examples of polyether polyols containing at least two groups selected from the group consisting of methylene and methine include polyethylene glycol and polypropylene glycol. Examples of polyether polyols containing at least three groups selected from the group consisting of methylene and methine include polytetramethylene glycol.

[0073] The polyfunctional isocyanate compound reacted with the polyol to obtain the urethane prepolymer can be one or more.

[0074] As a polyfunctional isocyanate compound, any suitable polyfunctional isocyanate compound that can be used to prepare urethane prepolymers can be used. Examples of such polyfunctional isocyanate compounds include: polyfunctional aliphatic isocyanate compounds, polyfunctional alicyclic isocyanate compounds, polyfunctional aromatic isocyanate compounds, and polyfunctional aromatic aliphatic isocyanate compounds.

[0075] Examples of polyfunctional aliphatic isocyanate compounds include: trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, 2,3-butylene diisocyanate, dodecamethyl diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate.

[0076] Examples of polyfunctional alicyclic isocyanate compounds include: 3-isocyanomethyl-3,5,5-trimethylcyclohexyl isocyanate, 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), 1,4-bis(isocyanomethyl)cyclohexane, 1,4-bis(isocyanomethyl)cyclohexane, hydrogenated diphenylmethane diisocyanate, hydrogenated phenyl dimethyl diisocyanate, hydrogenated toluene diisocyanate, and hydrogenated tetramethylphenyl dimethyl diisocyanate.

[0077] Examples of polyfunctional aromatic isocyanate compounds include: 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, 4,4'-diphenyl ether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 4,4',4”-triphenylmethane triisocyanate, dimethoxybenzidine diisocyanate, and phenyl dimethyl diisocyanate.

[0078] Examples of polyfunctional aromatic aliphatic isocyanate compounds include: ω,ω'-diisocyanate-1,3-dimethylbenzene, ω,ω'-diisocyanate-1,4-dimethylbenzene, ω,ω'-diisocyanate-1,4-diethylbenzene, 1,4-tetramethylbenzene dimethyl diisocyanate, and 1,3-tetramethylbenzene dimethyl diisocyanate.

[0079] Examples of polyfunctional isocyanate compounds include trimethylolpropane adducts, biuret forms formed by the reaction with water, and trimers containing isocyanurate rings, as described above. Furthermore, they can be used in combination.

[0080] To prepare the urethane prepolymer, it is preferable to use an equivalence ratio in which the isocyanate group (NCO group) of the polyfunctional isocyanate compound is in excess compared to the hydroxyl group (OH group) of the polyol. Such an equivalence ratio of NCO group to OH group ([NCO] / [OH]) is preferably 1.01 to 5.0, more preferably 1.1 to 3.0, further preferably 1.1 to 2.0, particularly preferably 1.1 to 1.8, and most preferably 1.2 to 1.6.

[0081] A catalyst can be used in the preparation of urethane prepolymers. Any suitable catalyst can be used without impairing the effects of the present invention. Examples of such catalysts include tertiary amine catalysts and organometallic catalysts. There may be only one catalyst or two or more catalysts.

[0082] Examples of tertiary amine catalysts include triethylamine, triethylenediamine, and 1,8-diazabicyclo(5,4,0)-undecene-7 (DBU).

[0083] Examples of organometallic catalysts include: bismuth-based catalysts such as bismuth octanoate, bismuth neodecanoate, bismuth naphthenate, and bismuth rosinate; tin-based catalysts such as dibutyltin dilaurate (DBTDL) and dioctyltin dilaurate (DOTDL); titanium-based catalysts such as dibutyltitanium dichloride, tetrabutyl titanate, butoxytitanium trichloride, and tetraacetylacetone titanium; iron-based catalysts such as ferric 2-ethylhexanoate and ferric acetylacetone; cobalt-based catalysts such as cobalt benzoate and cobalt 2-ethylhexanoate; zinc-based catalysts such as zinc octanoate, zinc naphthenate, and zinc 2-ethylhexanoate; and zirconium-based catalysts such as zirconium naphthenate.

[0084] When a catalyst is used in the preparation of the urethane prepolymer, the amount of catalyst used relative to the total amount of polyol and polyfunctional isocyanate compound is preferably 0.0001 wt% to 1.0 wt%, more preferably 0.001 wt% to 1.0 wt%, further preferably 0.003 wt% to 1.0 wt%, and particularly preferably 0.005 wt% to 1.0 wt%.

[0085] When a catalyst is used in the preparation of urethane prepolymers, the reaction temperature is preferably below 100°C, more preferably 85°C to 95°C. If the reaction temperature is above 100°C, it may become difficult to control the reaction rate and the crosslinking structure.

[0086] When preparing urethane prepolymers, a catalyst may not be used. In this case, the reaction temperature is preferably 100°C or higher, more preferably 110°C or higher. Furthermore, when preparing urethane prepolymers without a catalyst, the reaction time is preferably 3 hours or more.

[0087] As a method for preparing urethane prepolymers, any suitable method can be employed without impairing the effects of the present invention. Examples of such methods include: 1) a method of loading the polyol, catalyst, and polyfunctional isocyanate compound into a reaction vessel in their entirety; and 2) a method of loading the polyol and catalyst into a reaction vessel and then adding the polyfunctional isocyanate compound dropwise. In method 2), it is also possible to further add the polyol and polyfunctional isocyanate compound after the dropwise addition of the polyfunctional isocyanate compound.

[0088] In preparing urethane prepolymers, any suitable solvent can be used. Examples of such solvents include methyl ethyl ketone, ethyl acetate, toluene, xylene, and acetone.

[0089] In preparing the urethane prepolymer, any suitable other components may be used without impairing the effects of the present invention. Examples of such other components include: antioxidants, ultraviolet absorbers, light stabilizers, resin components, tackifiers, delayed crosslinking agents, inorganic fillers, organic fillers, metal powders, pigments, foils, softeners, anti-aging agents, conductive agents, surface lubricants, leveling agents, corrosion inhibitors, heat stabilizers, polymerization inhibitors, and lubricants. There may be only one or more of these other components. Among these other components, antioxidants, ultraviolet absorbers, and light stabilizers are preferred embodiments.

[0090] Examples of antioxidants include: free radical chain inhibitors and peroxide decomposers. Examples of free radical chain inhibitors include: phenolic antioxidants and amine antioxidants. Examples of peroxide decomposers include: sulfur-based antioxidants and phosphorus-based antioxidants.

[0091] Examples of UV absorbers include: benzophenone-based UV absorbers, benzotriazole-based UV absorbers, salicylic acid-based UV absorbers, oxaloyl aniline-based UV absorbers, cyanoacrylate-based UV absorbers, and triazine-based UV absorbers.

[0092] Examples of light stabilizers include hindered amine light stabilizers.

[0093] <A-1-2. Polyols as the base polymer (A)> The polyols (A) that form the base polymer can react with polyfunctional isocyanate compounds to form one-step urethane polymers.

[0094] Polyols can be a single type or two or more types.

[0095] As a polyol, at least one selected from the group consisting of polyester polyols, polyether polyols, polycaprolactone polyols, polycarbonate polyols, and castor oil-based polyols can be listed, and at least one selected from the group consisting of polyester polyols and polyether polyols is preferred.

[0096] Polyester polyols can be obtained, for example, through esterification of polyol components with acid components. Examples of polyol components include: ethylene glycol, diethylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-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, glycerol, trimethylolpropane, pentaerythritol, hexanetriol, and polypropylene glycol. Examples of acidic components include: succinic acid, methylsuccinic acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,12-dodecanoic acid, 1,14-tetradecanoic 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'-biphenyl dicarboxylic acid, and their anhydrides.

[0097] Examples of polyether polyols include those obtained by addition polymerization of alkyl oxidants such as ethylene oxide, propylene oxide, and glycerol using water, low-molecular-weight polyols (ethylene glycol, propylene glycol, glycerol, trimethylolpropane, pentaerythritol, etc.), bisphenols (bisphenol A, etc.), and dihydroxybenzenes (catechol, resorcinol, hydroquinone, etc.) as initiators. Representative examples of polyether polyols include at least one selected from the group consisting of polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

[0098] Examples of polycaprolactone polyols include caprolactone-based polyester diols obtained by ring-opening polymerization of cyclic ester monomers such as ε-caprolactone and σ-valerolactone.

[0099] Examples of polycarbonate polyols include: polycarbonate polyols obtained by polycondensation of the above-mentioned polyol components with carbonyl chloride; polycarbonate polyols obtained by transesterification condensation of the above-mentioned polyol components with dimethyl carbonate, diethyl carbonate, dipropyl carbonate, diisopropyl carbonate, dibutyl carbonate, ethylbutyl carbonate, ethylene carbonate, propylene carbonate, diphenyl carbonate, dibenzyl carbonate, etc., which are carbonate diesters; copolymerized polycarbonate polyols obtained by using two or more of the above-mentioned polyol components; and polycarbonate polyols obtained by esterification of the above-mentioned polycarbonate polyols with carboxyl-containing compounds. Polycarbonate polyols obtained by etherifying the above-mentioned polycarbonate polyols with hydroxyl-containing compounds; polycarbonate polyols obtained by transesterification of the above-mentioned polycarbonate polyols with ester compounds; polycarbonate polyols obtained by transesterification of the above-mentioned polycarbonate polyols with hydroxyl-containing compounds; polyester-based polycarbonate polyols obtained by polycondensation of the above-mentioned polycarbonate polyols with dicarboxylic acid compounds; and copolymer polyether-based polycarbonate polyols obtained by copolymerizing the above-mentioned polycarbonate polyols with epoxides.

[0100] Examples of castor oil-based polyols include those obtained by reacting castor oil fatty acids with the aforementioned polyol components. Specifically, examples include castor oil-based polyols obtained by reacting castor oil fatty acids with polypropylene glycol.

[0101] In view of aspects that can further demonstrate the effects of the present invention, the number average molecular weight Mn of the polyol is preferably 300 to 100,000, more preferably 400 to 75,000, even more preferably 450 to 50,000, and particularly preferably 500 to 30,000.

[0102] In view of further demonstrating the effects of the present invention, the polyol preferably contains a polyol (a) having a number-average molecular weight Mn of 300 to 100,000 having three OH groups. The polyol (a) may be only one type or may be two or more types.

[0103] In view of aspects that can further demonstrate the effects of the present invention, the content of polyol (a) in the polyol is preferably 5% by weight or more, more preferably 25% by weight to 100% by weight, more preferably 50% by weight to 100% by weight, particularly preferably 70% by weight to 100% by weight, and most preferably 90% by weight to 100% by weight.

[0104] In view of further demonstrating the effects of the present invention, the polyol (a) preferably contains a polyol (a1) having a number-average molecular weight Mn of 8000 to 20000 having three OH groups. The polyol (a1) may be only one type or may be two or more types.

[0105] In view of aspects that can further demonstrate the effects of the present invention, the number average molecular weight Mn of the polyol (a1) is preferably 8000-18000, more preferably 8500-16000, even more preferably 8500-14000, particularly preferably 9000-13000, and most preferably 9000-12000.

[0106] In view of aspects that can further demonstrate the effects of the present invention, the content of polyol (a1) in the polyol is preferably 50% by weight or more, more preferably 60% by weight to 100% by weight, further preferably 70% by weight to 95% by weight, particularly preferably 75% by weight to 93% by weight, and most preferably 80% by weight to 90% by weight.

[0107] The polyol (a) may also contain a polyol (a2) having three or more OH groups and a number-average molecular weight Mn of 5000 or less. The polyol (a2) is preferably at least one selected from the group consisting of polyols having three OH groups (triols), polyols having four OH groups (tetraols), polyols having five OH groups (pentanols), and polyols having six OH groups (hexanols). The polyol (a2) may be only one type or may be two or more types.

[0108] In view of aspects that can further demonstrate the effects of the present invention, the number average molecular weight Mn of the polyol (a2) is preferably 500 to 5000, more preferably 600 to 4500, further preferably 700 to 4000, particularly preferably 800 to 3500, and most preferably 900 to 3300.

[0109] In view of aspects that can further demonstrate the effects of the present invention, the content of polyol (a2) in the polyol is preferably 50% by weight or less, more preferably 0% to 40% by weight, further preferably 5% to 30% by weight, particularly preferably 7% to 25% by weight, and most preferably 10% to 20% by weight.

[0110] In view of aspects that can further demonstrate the effects of the present invention, the proportion of polyols (triols) having three OH groups in polyol (a2) is preferably 80% to 100% by weight, more preferably 90% to 100% by weight, further preferably 95% to 100% by weight, particularly preferably 97% to 100% by weight, and most preferably 99% to 100% by weight.

[0111] As a polyol (a2), a polyol having three OH groups (triol) is preferred in terms of further demonstrating the effects of the present invention. Both triols with a number average molecular weight Mn of 500 or more and less than 2000 and triols with a number average molecular weight Mn of 2000 to 5000 are preferred.

[0112] The number average molecular weight Mn of the triol with a number average molecular weight Mn of 500 or more and less than 2000 is preferably 600 to 1800, more preferably 700 to 1500, even more preferably 800 to 1300, and particularly preferably 900 to 1100.

[0113] The number average molecular weight Mn of the triol with a molecular weight Mn of 2000 to 5000 is preferably 2200 to 4500, more preferably 2400 to 4000, even more preferably 2600 to 3500, and particularly preferably 2800 to 3300.

[0114] In view of aspects that can further demonstrate the effects of the present invention, the proportion of triols with a number average molecular weight Mn of 500 or more and less than 2000 in the polyol is preferably 0.01% to 20% by weight, more preferably 0.05% to 15% by weight, further preferably 0.1% to 10% by weight, particularly preferably 0.5% to 5% by weight, and most preferably 1% to 3% by weight.

[0115] In view of aspects that can further demonstrate the effects of the present invention, the proportion of triols with a number average molecular weight Mn of 2000 to 5000 in the polyol is preferably 1% to 30% by weight, more preferably 2% to 25% by weight, further preferably 5% to 20% by weight, particularly preferably 7% to 20% by weight, and most preferably 9% to 17% by weight.

[0116] Polyols can also contain polyols with four or more OH groups and a number-average molecular weight (Mn) of less than 20,000. A polyol with four or more OH groups and a number-average molecular weight (Mn) of less than 20,000 can be a single type or two or more types.

[0117] <A-1-3. Polyfunctional Isocyanates> The urethane-based adhesive composition typically comprises a polyfunctional isocyanate compound. The polyfunctional isocyanate compound reacts with a base polymer (A) to become a urethane polymer. Specifically, the polyfunctional isocyanate compound can react with a urethane prepolymer, which is the base polymer (A), to become a prepolymer-type urethane polymer, or it can react with a polyol, which is the base polymer (A), to become a one-step urethane polymer.

[0118] The polyfunctional isocyanate compound that reacts with the base polymer (A) can be just one or more.

[0119] As the polyfunctional isocyanate compound that reacts with the base polymer (A), any suitable polyfunctional isocyanate compound that can be used for urethane esterification reactions can be used. For example, the polyfunctional isocyanate compound described above that can be used to prepare urethane prepolymers can be used as such a polyfunctional isocyanate compound.

[0120] When preparing a prepolymer-type urethane polymer by reacting a polyfunctional isocyanate compound with a urethane prepolymer as a base polymer (A), the equivalence ratio (〔NCO〕 / 〔OH〕) of the isocyanate group (NCO group) of the polyfunctional isocyanate compound to the hydroxyl group (OH group) of the urethane prepolymer is preferably 0.60 to 1.70, more preferably 0.70 to 1.70, further preferably 0.75 to 1.70, further preferably 1.00 to 1.70, further preferably 1.10 to 1.65, particularly preferably 1.15 to 1.62, most preferably 1.15 to 1.60, further preferably 1.20 to 1.60, or 1.25 to 1.60, or 1.30 to 1.60, or 1.35 to 1.60, or 1.40 to 1.60, or 1.45 to 1.60.

[0121] When a one-step urethane polymer is prepared by reacting a polyfunctional isocyanate compound with a polyol as the base polymer (A), the equivalence ratio ([NCO] / [OH]) of the isocyanate group (NCO group) of the polyfunctional isocyanate compound to the hydroxyl group (OH group) of the polyol is preferably 1.00 to 3.00, more preferably 1.10 to 2.50, even more preferably 1.20 to 2.00, and particularly preferably 1.30 to 1.90.

[0122] When preparing a prepolymer-type urethane polymer by reacting a polyfunctional isocyanate compound with a urethane prepolymer as the base polymer (A), the proportion of the polyfunctional isocyanate compound to 100 parts by weight of the urethane prepolymer is preferably 1.0 to 15 parts by weight, more preferably 2.0 to 13 parts by weight, even more preferably 2.3 to 11 parts by weight, particularly preferably 2.6 to 10 parts by weight, and most preferably 2.8 to 9 parts by weight.

[0123] When preparing a one-step urethane polymer by reacting a polyfunctional isocyanate compound with a polyol as the base polymer (A), the proportion of the polyfunctional isocyanate compound relative to 100 parts by weight of the polyol is preferably 1 to 30 parts by weight, more preferably 5 to 25 parts by weight, further preferably 8 to 22 parts by weight, particularly preferably 10 to 20 parts by weight, and most preferably 12 to 18 parts by weight.

[0124] Regarding the preparation of urethane polymers, any suitable method can be employed without impairing the effects of the present invention, as long as it involves curing a urethane-based adhesive composition containing a base polymer (A) and a polyfunctional isocyanate compound to form the urethane polymer. Examples of such methods include: applying the urethane-based adhesive composition containing the base polymer (A) and the polyfunctional isocyanate compound onto any suitable substrate, heating / drying as needed, curing as needed, forming an adhesive layer on the substrate, and preparing the polymer in this adhesive layer. The coating method, heating / drying conditions, curing conditions, etc., can be appropriately employed using methods commonly known for forming adhesive layers.

[0125] <A-1-4. Catalyst> To facilitate the reaction between the base polymer (A) and the polyfunctional isocyanate compound, a catalyst can be used in the urethane-based adhesive composition. Any suitable catalyst can be used without impairing the effects of the present invention. Examples of such catalysts include those described above that can be used to prepare urethane prepolymers.

[0126] When a catalyst is used in the preparation of the urethane polymer, the content of the catalyst in the urethane-based adhesive composition, converted to solids, is preferably 0.0001 to 1.0 parts by weight relative to 100 parts by weight of the base polymer (A), more preferably 0.001 to 1.0 parts by weight, even more preferably 0.003 to 1.0 parts by weight, and particularly preferably 0.005 to 1.0 parts by weight.

[0127] <A-1-5. Organosilicon compounds (B)> The urethane-based adhesive composition contains an organosilicon compound (B). The organosilicon compound (B) may be one or more.

[0128] The content of the organosilicon compound (B) in the urethane-based adhesive composition, relative to 100 parts by weight of the base polymer (A) in solids form, is preferably 0.001 to 20 parts by weight, more preferably 0.005 to 10 parts by weight, further preferably 0.01 to 7 parts by weight, even more preferably 0.02 to 4 parts by weight, particularly preferably 0.03 to 2 parts by weight, and most preferably 0.04 to 1 part by weight. If the content of the organosilicon compound (B) in the urethane-based adhesive composition is within the above range, the effects of the present invention are further demonstrated.

[0129] The organosilicon compound (B) typically comprises at least one selected from the group consisting of reactive and non-reactive silicone oils. The proportion of at least one selected from the group consisting of reactive and non-reactive silicone oils in the organosilicon compound (B) is preferably 50% to 100% by weight, more preferably 70% to 100% by weight, further preferably 90% to 100% by weight, particularly preferably 95% to 100% by weight, and most preferably 98% to 100% by weight.

[0130] As an organosilicon compound (B), in addition to comprising at least one selected from the group consisting of reactive and non-reactive silicone oils, any other suitable organosilicon compound may be included to the extent that it does not impair the effects of the present invention.

[0131] Examples of reactive silicone oils include: side-chain reactive silicone oils in which organic groups are bonded as side chains to Si atoms that provide siloxane bonds; two-terminal reactive silicone oils in which organic groups are bonded to Si atoms at both ends of the structure; single-terminal reactive silicone oils in which only one of the Si atoms at both ends of the structure is bonded with an organic group; and two-terminal reactive silicone oils in which organic groups are bonded as side chains to Si atoms that provide siloxane bonds and organic groups are bonded to Si atoms at both ends of the structure.

[0132] Examples of side-chain reactive silicone oils include, for example, amino-modified, epoxy-modified, methanol-modified, mercapto-modified, carboxyl-modified, and methylhydrosilicone oils. Commercially available examples include various silicone oils manufactured by Shin-Etsu Chemical Co., Ltd.

[0133] Examples of two-terminated reactive silicone oils include, for example, amino-modified two-terminated reactive silicone oils, epoxy-modified two-terminated reactive silicone oils, methanol-modified two-terminated reactive silicone oils, methacrylic acid-modified two-terminated reactive silicone oils, polyether-modified two-terminated reactive silicone oils, mercapto-modified two-terminated reactive silicone oils, carboxyl-modified two-terminated reactive silicone oils, phenol-modified two-terminated reactive silicone oils, silanol-terminated two-terminated reactive silicone oils, acrylic acid-modified two-terminated reactive silicone oils, and carboxylic anhydride-modified two-terminated reactive silicone oils. Commercially available examples include various silicone oils manufactured by Shin-Etsu Chemical Co., Ltd.

[0134] Examples of single-terminal reactive silicone oils include: single-terminal reactive modified silicone oils, and single-terminal reactive silicone oils modified with an average single-terminal carboxyl group. More specifically, methanol-modified single-terminal reactive silicone oils are an example. Commercially available examples include various silicone oils manufactured by Shin-Etsu Chemical Industry Co., Ltd.

[0135] Examples of reactive silicone oils with two-terminal side chains include: reactive silicone oils modified with amino / methoxy groups on the side chains, and reactive silicone oils modified with epoxy groups. Commercially available examples include various silicone oils manufactured by Shin-Etsu Chemical Co., Ltd.

[0136] Examples of non-reactive silicone oils include: side-chain type non-reactive silicone oils in which organic groups are bonded to the Si atoms that provide siloxane bonds as side chains, and two-terminal type non-reactive silicone oils in which organic groups are bonded to the Si atoms located at both ends of the structure.

[0137] Examples of side-chain non-reactive silicone oils include: polyether-modified side-chain non-reactive silicone oils, aralkyl-modified side-chain non-reactive silicone oils, fluoroalkyl-modified side-chain non-reactive silicone oils, long-chain alkyl-modified side-chain non-reactive silicone oils, higher fatty acid ester-modified side-chain non-reactive silicone oils, side-chain non-reactive silicone oils containing higher fatty acids, and phenyl-modified side-chain non-reactive silicone oils. Commercially available examples include various silicone oils manufactured by Shin-Etsu Chemical Industry Co., Ltd.

[0138] Examples of two-terminated non-reactive silicone oils include, for example, polyether-modified two-terminated non-reactive silicone oils. Commercially available examples include various silicone oils manufactured by Shin-Etsu Chemical Co., Ltd., which are commercially available as two-terminated non-reactive silicone oils.

[0139] In a preferred embodiment of the organosilicon compound (B), it comprises at least one selected from the group consisting of organosilicon compounds having a polyether structure and organosilicon compounds having a methanol structure. The content of at least one selected from the group consisting of organosilicon compounds having a polyether structure and organosilicon compounds having a methanol structure in the organosilicon compound (B) is preferably 50% to 100% by weight, more preferably 70% to 100% by weight, further preferably 90% to 100% by weight, particularly preferably 95% to 100% by weight, and most preferably 98% to 100% by weight.

[0140] In a more preferred embodiment of the organosilicon compound (B), an organosilicon compound having a polyether structure is included. The proportion of the organosilicon compound having a polyether structure in the organosilicon compound (B) is preferably 50% to 100% by weight, more preferably 70% to 100% by weight, further preferably 90% to 100% by weight, particularly preferably 95% to 100% by weight, and most preferably 98% to 100% by weight. If the organosilicon compound (B) includes an organosilicon compound having a polyether structure, the surface protective film of the embodiment of the present invention exhibits superior antistatic properties.

[0141] Examples of organosilicon compounds with polyether structures include: the above-mentioned polyether-modified two-terminal reactive silicone oils, polyether-modified side-chain non-reactive silicone oils, and polyether-modified two-terminal non-reactive silicone oils.

[0142] Commercially available products of polyether-modified two-terminal reactive silicone oils include, for example, Shin-Etsu Chemical Co., Ltd.'s "X-22-4952", "X-22-4272", and "KF-6123".

[0143] Commercially available products of polyether-modified side-chain non-reactive silicone oils include, for example, Shin-Etsu Chemical Industry Co., Ltd.'s "KF-351A", "KF-352A", "KF-353", "KF-354L", "KF-355A", "KF-615A", "KF-945", "KF-640", "KF-642", "KF-643", "KF-644", "KF-6020", "KF-6204", "X-22-4515", "KF-6011", "KF-6012", "KF-6015", "KF-6017", and "X-22-2516".

[0144] Commercially available products that are two-terminated non-reactive silicone oils modified with polyethers include, for example, "KF-6004" manufactured by Shin-Etsu Chemical Industry Co., Ltd.

[0145] Examples of organosilicon compounds with a methanol structure include: the methanol-modified side-chain reactive silicone oil, the methanol-modified two-terminal reactive silicone oil, and the methanol-modified single-terminal reactive silicone oil.

[0146] Commercially available products that are methanol-modified side-chain reactive silicone oils include, for example, Shin-Etsu Chemical Co., Ltd.'s "X-22-4039" and "X-22-4015".

[0147] Commercially available products of methanol-modified two-terminal reactive silicone oils include, for example, Shin-Etsu Chemical Co., Ltd.'s "KF-6000", "KF-6001", "KF-6002" and "KF-6003".

[0148] Commercially available single-terminal reactive silicone oils of the methanol-modified type include, for example, Shin-Etsu Chemical Co., Ltd.'s "X-22-170BX" and "X-22-170DX".

[0149] The organosilicon compound (B) having a polyether structure is preferably at least one selected from the group consisting of reactive silicone oils and non-reactive silicone oils with an HLB value of 15 or less. If the organosilicon compound (B) is an organosilicon compound having a polyether structure and is at least one selected from the group consisting of reactive silicone oils and non-reactive silicone oils with an HLB value of 15 or less, then, for example, it can provide a surface protective film that further reduces the aforementioned rate of increase in adhesion to glass plates over time, further suppresses the increase in adhesion to the adhered object over time, and provides more moderate adhesion and easier peeling even after time has passed since it was applied to the adhered object.

[0150] Organosilicon compounds that are organosilicon compounds with a polyether structure and are reactive silicone oils include, for example, the above-mentioned polyether-modified two-terminal reactive silicone oils.

[0151] Commercially available polyether-modified two-terminal reactive silicone oils include, for example, Shin-Etsu Chemical Co., Ltd.'s "X-22-4952", "X-22-4272", and "KF-6123".

[0152] Examples of non-reactive silicone oils that are organosilicon compounds with a polyether structure and an HLB value of 15 or less include: the aforementioned polyether-modified side-chain type non-reactive silicone oil with an HLB value of 15 or less, and the aforementioned polyether-modified two-terminal type non-reactive silicone oil with an HLB value of 15 or less.

[0153] Examples of non-reactive silicone oils with HLB values ​​of 15 or less, which are side-chain modified polyether-type silicone oils, include: Shin-Etsu Chemical Industry Co., Ltd.'s "KF-351A" (HLB=12), "KF-352A" (HLB=7), "KF-353" (HLB=10), "KF-355A" (HLB=12), "KF-615A" (HLB=10), "KF-945" (HLB=4), "KF-640" (HLB=14), and "KF-642" (HLB=15). HLB=12), "KF-643" (HLB=14), "KF-644" (HLB=11), "KF-6020" (HLB=4), "KF-6204" (HLB=10), "X-22-4515" (HLB =5), "KF-6011" (HLB=12), "KF-6012" (HLB=7), "KF-6015" (HLB=5), "KF-6017" (HLB=5), "X-22-2516" (HLB=1).

[0154] For example, non-reactive silicone oils with HLB values ​​of 15 or less, such as the two-terminated non-reactive silicone oils modified with polyether, include "KF-6004" (HLB=9) manufactured by Shin-Etsu Chemical Industry Co., Ltd.

[0155] <A-1-6. Ionic Compounds (C)> The urethane-based adhesive composition contains an ionic compound (C). The ionic compound (C) may be one or more.

[0156] The content of the ionic compound (C) in the urethane-based adhesive composition, converted to solids, relative to 100 parts by weight of the base polymer (A), is preferably 0.01 to 5.0 parts by weight, more preferably 0.01 to 4.0 parts by weight, further preferably 0.01 to 2.8 parts by weight, even more preferably 0.05 to 2.0 parts by weight, particularly preferably 0.1 to 1.0 parts by weight, and most preferably 0.1 to 0.5 parts by weight. If the content of the ionic compound (C) in the urethane-based adhesive composition is within the above range, the effects of the present invention are further demonstrated. If the content of the ionic compound (C) in the urethane-based adhesive composition deviates excessively from the above range, the haze of the surface protective film may increase, and the transparency of the surface protective film may decrease. For example, it may be impossible to accurately inspect the surface of the surface protective film when it is adhered to the surface of the adhered object, such as an optical component or electronic component, or the degree of contamination of the adhered object may increase. If the content of ionic compound (C) in the urethane-based adhesive composition deviates from the above range and is too low, it may not exhibit excellent antistatic properties.

[0157] As the ionic compound (C), any suitable ionic compound can be used within the scope of not impairing the effects of the present invention. As such an ionic compound (C), an ionic liquid is preferred. An ionic liquid refers to a molten salt (ionic compound) that is liquid at 25°C.

[0158] As an ionic liquid, any suitable ionic liquid can be used within the scope of not impairing the effects of the present invention. As such an ionic liquid, considering aspects that further enhance the effects of the present invention, an ionic liquid containing a fluorinated organic anion is preferred, and an ionic liquid composed of a fluorinated organic anion and an onium cation is more preferred.

[0159] As ionic liquids, those preferred for further demonstrating the effects of the present invention include: 1-hexylpyridinium bis(fluorosulfonyl)imide, 1-ethyl-3-methylpyridinium trifluoromethanesulfonate, 1-ethyl-3-methylpyridinium pentafluoroethanesulfonate, 1-ethyl-3-methylpyridinium heptafluoropropanesulfonate, 1-ethyl-3-methylpyridinium nonafluorobutanesulfonate, 1-butyl-3-methylpyridinium trifluoromethanesulfonate, 1-butyl-3-methylpyridinium bis(fluoromethanesulfonyl)imide, 1-octyl-4-methylpyridinium bis(fluorosulfonyl)imide, 1-methyl-1-propylpyrrolidine bis(fluoromethanesulfonyl)imide, 1-methyl-1-propylpyrrolidine bis(fluorosulfonyl)imide, 1 -Methyl-1-propylpiperidinium bis(trifluoromethanesulfonyl)imide, 1-methyl-1-propylpiperidinium bis(fluorosulfonyl)imide, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium heptafluoropropanesulfonate, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide, 1-hexyl-3-methylimidazolium bis(fluorosulfonyl)imide, trimethylpropylammonium bis(trifluoromethanesulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(fluorosulfonyl)imide, and more preferably, 1-butyl-3-methylpyridinium bis(trifluoromethanesulfonyl)imide and 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide.

[0160] Ionic liquids can be commercially available or synthetically produced. Examples of methods for synthesizing ionic liquids include conventional methods such as the halide method, hydroxide method, ester method, complex formation method, and neutralization method, as described in the document "Ionic Liquids – The Frontline and Future of Development –" (published by CMC Corporation).

[0161] <A-1-7. Other Components> The urethane-based adhesive composition may contain any suitable other components without impairing the effects of the present invention. Such other components include, for example: solvents, crosslinking accelerators, silane coupling agents, antioxidants, ultraviolet absorbers, light stabilizers, resin components, tackifiers, delayed crosslinking agents, inorganic fillers, organic fillers, metal powders, colorants (pigments, dyes, etc.), chain transfer agents, plasticizers, softeners, anti-aging agents, conductive agents, foils, surface lubricants, leveling agents, corrosion inhibitors, heat stabilizers, polymerization inhibitors, and lubricants. Other components may be one or more.

[0162] A-2. Substrate The substrate can be a single layer or two or more layers. The substrate can be a stretched substrate.

[0163] The thickness of the substrate is preferably 4μm to 450μm, more preferably 8μm to 400μm, even more preferably 12μm to 350μm, and particularly preferably 16μm to 250μm.

[0164] For the purpose of forming easily rewound coils, release treatment can be performed on the surface of the substrate without an adhesive layer, for example, by adding fatty acid amides, polyethylene imine, long-chain alkyl additives, etc., or by applying a coating formed by any suitable release agent such as organosilicon, long-chain alkyl, or fluorine.

[0165] The substrate material can be any suitable material depending on the application. Examples include: plastic, paper, metal film, non-woven fabric, etc. Plastic is preferred. That is, the substrate is preferably a plastic film. The substrate can be composed of one material or two or more materials. For example, it can be composed of two or more plastics.

[0166] Examples of the aforementioned plastics include polyester resins, polyamide resins, and polyolefin resins. Examples of polyester resins include polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate.

[0167] The substrate can contain any suitable additives as needed. Examples of additives that can be included in the substrate include: antioxidants, UV absorbers, light stabilizers, antistatic agents, fillers, and pigments. The type, quantity, and amount of additives that the substrate can contain can be appropriately determined according to the purpose. In particular, when the substrate material is plastic, it is preferable to contain several of the above-mentioned additives for the purpose of preventing deterioration. From the viewpoint of improving weather resistance, antioxidants, UV absorbers, light stabilizers, and fillers are particularly preferred as additives.

[0168] 《B. Application》 The surface protective film of the present invention, in embodiments thereof, can be applied to the exposed surface of optical components or electronic components during the manufacturing process of optical components or electronic components to prevent scratches on the surface of the optical components or electronic components during processing, assembly, inspection, transportation, etc., and is preferably used for surface protection of optical components or electronic components. The optical components of the present invention are coated with the surface protective film of the present invention. The electronic components of the present invention are coated with the surface protective film of the present invention.

[0169] Example The present invention will now be specifically described through examples, but the present invention is not limited to these examples in any way. It should be noted that the testing and evaluation methods in the examples are as follows. It should be noted that when "parts" are used, they refer to "parts by weight" unless otherwise specified; and when "%" are used, they refer to "% by weight" unless otherwise specified.

[0170] <Determination of Fluorine Content in Adhesive Layer> Take about 10 mg of adhesive from the adhesive layer from which the protective film on the release liner has been peeled off, put it into a ceramic boat and weigh it, then add 100 mg of combustion accelerant (manufactured by KISHIDA CHEMICAL, trade name "Tungsten Oxide (VI) (Powder)").

[0171] Next, the sample was burned using an automatic sample combustion device (Nittoseiko Analytech, AQF-2100H), and the generated gas was collected into 10 mL of absorbent.

[0172] Temperature: 1000℃ at the inlet / 1100℃ at the outlet.

[0173] Gas flow rates: O2 400 mL / min, Ar 200 mL / min, Ar water delivery unit 100 mL / min.

[0174] After collection, ultrapure water was added to the absorption solution to adjust the volume to 15 mL. The adjusted liquid and the further appropriately diluted liquid were then subjected to quantitative analysis using IC (Thermo Fisher Scientific, ICS-3000) to determine the fluoride content in the adhesive layer.

[0175] Separation column and guard column: Dionex IonPac AS18-fast (4mm×150mm) / Dionex IonPac AG18-fast (4mm×30mm).

[0176] Remove system: Dionex ADRS-600.

[0177] Detector: Conductivity detector.

[0178] Elution buffer composition: KOH aqueous solution.

[0179] Eluent flow rate: 1.2 mL / min.

[0180] Sample injection volume: 250 μL.

[0181] <Determination of the surface free energy of the adhesive layer surface against diiodomethane> The protective film, from which the release liner was removed, was cut into pieces 50 mm wide and 100 mm long. The adhesive layer surface was designated as the top surface and fixed to a contact angle meter (Kyowa Interface Science Co., Ltd., model "CA-X"). 2.0 μL of water was added to the adhesive layer surface, and the contact angle was measured. Then, in the same order, 2.0 μL of diiodomethane was added to the adhesive layer surface, and the contact angle was measured again. Based on the contact angle values ​​of the two liquids, the surface free energy of the adhesive layer surface relative to diiodomethane was calculated using the Owens-Wendt method.

[0182] <Determination of electrostatic voltage for glass plate peeling> In an environment of 23°C and 50% RH, the protective film with the release liner removed was cut into dimensions of 70mm in width and 100mm in length. The protective film was pressed onto the surface of the glass plate (ordinary soda-lime glass, manufactured by Matsunami Glass Industry Co., Ltd.) with a 2kg hand roller, so that one end of the protective film protruded 30mm from the end of the glass plate.

[0183] After placing the sample at 23°C and 50% RH for one day, it was placed on a sample holder 20 mm high. The end of the protective film protruding 30 mm from the glass plate was fixed to an automatic winding machine, and peeling was performed at a peeling angle of 150 degrees and a peeling speed of 30 m / min. The potential generated on the glass plate surface at this point was measured using a potentiometer (SHISHIDOELECTROSTATIC, model "STATIRON DZ-4") fixed 30 mm above the center of the glass plate; this potential was defined as the electrostatic voltage at which the glass plate was peeled off. The measurements were conducted at 23°C and 50% RH.

[0184] <Determination of the high-temperature, low-speed adhesive strength of glass plate No. 31B> In an environment of 23°C and 50% RH, the protective film on the surface after the release liner was peeled off was cut into 100mm×100mm pieces and pressed onto the surface of a glass plate (ordinary soda-lime glass, manufactured by Matsunami Glass Industry Co., Ltd.) with a 2kg hand roller. After being placed at an ambient temperature of 23°C for 1 day, the protective film was peeled off from the glass plate in an environment of 23°C and 50% RH. No. 31B tape (manufactured by Nitto Denko Co., Ltd.) was then applied to the peeled surface of the glass plate with a 2kg hand roller, thus producing a sample.

[0185] The sample was placed in a Shimadzu Autograph AG-Xplus tensile testing machine with a thermostatic bath. The temperature inside the thermostatic bath was set to 85°C and the test was started after 5 minutes. The test conditions were set as follows: peel angle 180 degrees and peel speed (tensile speed) 10 mm / min. The peel force (load) when No.31B tape was peeled from the glass plate was measured, and the average peel force (average load) at this point was taken as the high-temperature, low-speed adhesion force of No.31B tape to the glass plate.

[0186] <Measurement of Haze> In an environment of 23°C and 50% RH, the protective film on the surface after the release liner was peeled off was cut into 50mm × 50mm pieces and measured using the "HM-150N" manufactured by Murakami Color Technology Research Institute Co., Ltd.

[0187] <Determination of the adhesive strength of glass plates (I) (after standing at 23°C for 30 minutes)> In an environment of 23°C and 50% RH, the protective film on the surface after the release liner has been peeled off was cut into pieces 25mm wide and 140mm long, and pressed onto the surface of a glass plate (ordinary soda-lime glass, manufactured by Matsunami Glass Industry Co., Ltd.) with a 2kg hand roller in one reciprocating motion to make a sample.

[0188] After placing the sample at an ambient temperature of 23°C for 30 minutes, the sample was placed in a tensile testing machine to begin the tensile test. The tensile test conditions were set at 23°C, 50% RH, a peel angle of 180 degrees, and a peel speed (tensile speed) of 300 mm / min. The peel force (load) when the surface protective film was peeled from the glass plate was measured, and the average peel force (average load) at this time was set as the adhesion force (I) to the glass plate (sometimes simply referred to as adhesion force (I)). The tensile testing machine used was the Shimadzu Corporation's "Autograph AG-Xplus HS 6000 mm / min high-speed mode (AG-50NXplus)".

[0189] <Determination of the adhesive strength of glass plates (II) (after 1 day at 50°C)> In an environment of 23°C and 50% RH, the protective film on the surface after the release liner has been peeled off was cut into pieces 25mm wide and 140mm long, and pressed onto the surface of a glass plate (ordinary soda-lime glass, manufactured by Matsunami Glass Industry Co., Ltd.) with a 2kg hand roller in one reciprocating motion to make a sample.

[0190] After placing the sample at an ambient temperature of 50°C for one day, the sample was placed in a tensile testing machine to begin the tensile test. The tensile test conditions were set at 23°C, 50% RH, a peel angle of 180 degrees, and a peel speed (tensile speed) of 300 mm / min. The peel force (load) when the surface protective film was peeled from the glass plate was measured, and the average peel force (average load) at this time was set as the adhesion force (II) to the glass plate (sometimes simply referred to as adhesion force (II)). The tensile testing machine used was the Shimadzu Corporation's "Autograph AG-Xplus HS 6000 mm / min high-speed mode (AG-50NX plus)".

[0191] <Calculation of the rate of increase in adhesive force over time for glass plates> It is calculated using the formula [adhesive force (II) / adhesive force (I)] × 100 (%).

[0192] [Manufacturing Example 1]: Manufacturing of urethane prepolymer A A 1L round-bottom separable flask, a separable cap, a separatory funnel, a thermometer, a nitrogen inlet tube, a Liebig condenser, a vacuum seal, a stir bar, and stirrer blades were used to add 260g of polytetramethylene glycol (PTMG3000, manufactured by Mitsubishi Chemical Corporation), 173g of polypropylene glycol (SANNIX GP-1500, manufactured by Sanyo Chemical Corporation), and 150g of ethyl acetate (manufactured by TOSOH Corporation) as solvent. While stirring, 0.05g of bismuth octoate (manufactured by Nippon Chemical Industries Co., Ltd.) as catalyst was added, and nitrogen replacement was carried out at room temperature for 1 hour. Then, under nitrogen inflow, 15g of hexamethylene diisocyanate (HDI, manufactured by TOSOH Corporation) was added while stirring. The solution temperature in the experimental apparatus was controlled at 90±2℃ using a water bath and maintained for 4 hours to carry out polymerization, yielding a solution of urethane prepolymer A. It should be noted that during polymerization, ethyl acetate was added dropwise to prevent a decrease in agitation caused by temperature control and viscosity increases. The total amount of ethyl acetate added was 300g. The solids concentration of the carbamate prepolymer A solution was 50% by weight.

[0193] [Manufacturing Example 2]: Manufacturing of urethane prepolymer B A 1L round-bottom separable flask, a separable cap, a separatory funnel, a thermometer, a nitrogen inlet tube, a Liebig condenser, a vacuum seal, a stirring rod, and stirring blades were equipped with 347g of polypropylene glycol (product name "SANNIX PP-2000", manufactured by Sanyo Chemical Industry Co., Ltd.), 47g of polyester polyol (product name "Kuraray Polyol P-2010", manufactured by Kurara Corporation), 110g of toluene (manufactured by TOSOH Corporation) as solvent, and 0.041g of bismuth octoate (manufactured by Nippon Chemical Industry Co., Ltd.) as catalyst. Nitrogen replacement was carried out at room temperature for 1 hour while stirring. Then, under nitrogen inflow, hexamethylene diisocyanate (product name "HDI", manufactured by TOSOH) 33.5g was added while stirring. The solution temperature in the experimental apparatus was controlled at 90±2℃ using a water bath and maintained for 4 hours. Next, polypropylene glycol (product name "GP1000", manufactured by Sanyo Chemical Industries) 44g was added. The solution temperature in the experimental apparatus was controlled at 90±2℃ using a water bath and maintained for 2 hours. Then, hexamethylene diisocyanate (product name "HDI", manufactured by TOSOH) 25.4g was added. The solution temperature in the experimental apparatus was controlled at 90±2℃ using a water bath and maintained for 2 hours, resulting in a solution of urethane prepolymer B. It should be noted that during polymerization, toluene was added dropwise to prevent a decrease in agitation due to temperature control and viscosity increases. The total amount of toluene added was 380g. The solids concentration of the urethane prepolymer B solution was 50% by weight.

[0194] [Example 1] A urethane-based adhesive composition (1) was obtained by diluting 100 parts by weight of urethane prepolymer A, 4.0 parts by weight of a polyfunctional isocyanate compound (CORONATE HX (C / HX), manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent, 0.10 parts by weight of KF-354L (manufactured by Shin-Etsu Chemical Co., Ltd.) as an organosilicon compound, 0.30 parts by weight of AS100 (manufactured by Nippon Emulsifier Co., Ltd.) as an antistatic agent, 0.50 parts by weight of Irganox1010 (manufactured by BASF Co., Ltd.) as an antioxidant, and 0.20 parts by weight of Nikka Octhix Zinc 18% (manufactured by Nippon Chemical Industry Co., Ltd.) as a catalyst with ethyl acetate.

[0195] A urethane-based adhesive composition (1) was applied to a polyester resin substrate (trade name "T100-75S", thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) to a thickness of 75 μm after drying. The substrate was cured and dried at a drying temperature of 150°C for 3 minutes to create an adhesive layer (1). Next, a 25 μm thick release liner made of polyester resin (trade name "MRF25", thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) with one side treated with silicone was bonded to the surface of the adhesive layer (1) to obtain a surface protective film (1). The film was then aged at room temperature for 5 days for various evaluations.

[0196] The results are shown in Tables 1 and 2.

[0197] [Example 2] A urethane-based adhesive composition (2) was obtained by diluting 100 parts by weight of urethane prepolymer A, 4.0 parts by weight of a polyfunctional isocyanate compound (CORONATE HX (C / HX), manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent, 0.10 parts by weight of KF-640 (manufactured by Shin-Etsu Chemical Co., Ltd.) as an organosilicon compound, 0.30 parts by weight of AS100 (manufactured by Nippon Emulsifier Co., Ltd.) as an antistatic agent, 0.50 parts by weight of Irganox 1010 (manufactured by BASF Co., Ltd.) as an antioxidant, and 0.20 parts by weight of Nikka Octthix Zinc 18% (manufactured by Nippon Chemical Industry Co., Ltd.) as a catalyst with ethyl acetate.

[0198] The urethane-based adhesive composition (2) was used instead of the urethane-based adhesive composition (1), and otherwise the same procedure was followed as in Example 1 to obtain the adhesive layer (2) and the surface protective film (2). Various evaluations were performed after 5 days of aging at room temperature.

[0199] The results are shown in Tables 1 and 2.

[0200] [Example 3] A urethane-based adhesive composition (3) was obtained by diluting 100 parts by weight of urethane prepolymer A, 4.0 parts by weight of a polyfunctional isocyanate compound (CORONATE HX (C / HX), manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent, 0.10 parts by weight of X-22-4515 (manufactured by Shin-Etsu Chemical Co., Ltd.) as an organosilicon compound, 0.30 parts by weight of AS100 (manufactured by Nippon Emulsifier Co., Ltd.) as an antistatic agent, 0.50 parts by weight of Irganox1010 (manufactured by BASF Co., Ltd.) as an antioxidant, and 0.20 parts by weight of Nikka Octhix Zinc 18% (manufactured by Nippon Chemical Industry Co., Ltd.) as a catalyst with ethyl acetate to a total solid content of 50% by weight.

[0201] The urethane-based adhesive composition (3) was used instead of the urethane-based adhesive composition (1), and otherwise the same procedure was followed as in Example 1 to obtain the adhesive layer (3) and the surface protective film (3). Various evaluations were performed after 5 days of aging at room temperature.

[0202] The results are shown in Tables 1 and 2.

[0203] [Example 4] A urethane-based adhesive composition (4) was obtained by diluting 100 parts by weight of urethane prepolymer A, 4.0 parts by weight of a polyfunctional isocyanate compound (CORONATE HX (C / HX), manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent, 0.10 parts by weight of KF-6001 (manufactured by Shin-Etsu Chemical Co., Ltd.) as an organosilicon compound, 0.30 parts by weight of AS100 (manufactured by Nippon Emulsifier Co., Ltd.) as an antistatic agent, 0.50 parts by weight of Irganox1010 (manufactured by BASF Co., Ltd.) as an antioxidant, and 0.20 parts by weight of Nikka Octhix Zinc 18% (manufactured by Nippon Chemical Industry Co., Ltd.) as a catalyst with ethyl acetate to a total solid content of 50% by weight.

[0204] The urethane-based adhesive composition (4) was used instead of the urethane-based adhesive composition (1), and otherwise the same procedure was followed as in Example 1 to obtain the adhesive layer (4) and the surface protective film (4). Various evaluations were performed after 5 days of aging at room temperature.

[0205] The results are shown in Tables 1 and 2.

[0206] [Example 5] A urethane-based adhesive composition (5) was obtained by diluting 100 parts by weight of urethane prepolymer A, 4.0 parts by weight of a polyfunctional isocyanate compound (CORONATE HX (C / HX), manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent, 0.10 parts by weight of X-22-4272 (manufactured by Shin-Etsu Chemical Co., Ltd.) as an organosilicon compound, 0.30 parts by weight of AS100 (manufactured by Nippon Emulsifier Co., Ltd.) as an antistatic agent, 0.50 parts by weight of Irganox1010 (manufactured by BASF Co., Ltd.) as an antioxidant, and 0.20 parts by weight of Nikka Octhix Zinc 18% (manufactured by Nippon Chemical Industry Co., Ltd.) as a catalyst with ethyl acetate to a total solid content of 50% by weight.

[0207] The urethane-based adhesive composition (5) was used instead of the urethane-based adhesive composition (1), and otherwise the same procedure was followed as in Example 1 to obtain the adhesive layer (5) and the surface protective film (5). Various evaluations were performed after 5 days of aging at room temperature.

[0208] The results are shown in Tables 1 and 2.

[0209] [Example 6] A urethane-based adhesive composition (6) was obtained by diluting 100 parts by weight of urethane prepolymer A, 4.0 parts by weight of a polyfunctional isocyanate compound (CORONATE HX (C / HX), manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent, 0.10 parts by weight of KF-615A (manufactured by Shin-Etsu Chemical Co., Ltd.) as an organosilicon compound, 0.30 parts by weight of AS100 (manufactured by Nippon Emulsifier Co., Ltd.) as an antistatic agent, 0.50 parts by weight of Irganox1010 (manufactured by BASF Co., Ltd.) as an antioxidant, and 0.20 parts by weight of Nikka Octhix Zinc 18% (manufactured by Nippon Chemical Industry Co., Ltd.) as a catalyst with ethyl acetate to a total solid content of 50% by weight.

[0210] The urethane-based adhesive composition (6) was used instead of the urethane-based adhesive composition (1), and otherwise the same procedure was followed as in Example 1 to obtain the adhesive layer (6) and the surface protective film (6). Various evaluations were performed after 5 days of aging at room temperature.

[0211] The results are shown in Tables 1 and 2.

[0212] [Example 7] A urethane-based adhesive composition (7) was obtained by diluting 100 parts by weight of urethane prepolymer A, 4.0 parts by weight of a polyfunctional isocyanate compound (CORONATE HX (C / HX), manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent, 0.10 parts by weight of KF-615A (manufactured by Shin-Etsu Chemical Co., Ltd.) as an organosilicon compound, 1.00 parts by weight of AS100 (manufactured by Nippon Emulsifier Co., Ltd.) as an antistatic agent, 0.50 parts by weight of Irganox1010 (manufactured by BASF Co., Ltd.) as an antioxidant, and 0.20 parts by weight of Nikka Octhix Zinc 18% (manufactured by Nippon Chemical Industry Co., Ltd.) as a catalyst with ethyl acetate to a total solid content of 50% by weight.

[0213] The urethane-based adhesive composition (7) was used instead of the urethane-based adhesive composition (1), and otherwise the same procedure was followed as in Example 1 to obtain the adhesive layer (7) and the surface protective film (7). Various evaluations were performed after 5 days of aging at room temperature.

[0214] The results are shown in Tables 1 and 2.

[0215] [Example 8] A urethane-based adhesive composition (8) was obtained by diluting 100 parts by weight of urethane prepolymer A, 4.0 parts by weight of a polyfunctional isocyanate compound (CORONATE HX (C / HX), manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent, 0.10 parts by weight of KF-615A (manufactured by Shin-Etsu Chemical Co., Ltd.) as an organosilicon compound, 3.00 parts by weight of AS100 (manufactured by Nippon Emulsifier Co., Ltd.) as an antistatic agent, 0.50 parts by weight of Irganox1010 (manufactured by BASF Co., Ltd.) as an antioxidant, and 0.20 parts by weight of Nikka Octhix Zinc 18% (manufactured by Nippon Chemical Industry Co., Ltd.) as a catalyst with ethyl acetate to a total solid content of 50% by weight.

[0216] The urethane-based adhesive composition (8) was used instead of the urethane-based adhesive composition (1), and otherwise the same procedure was followed as in Example 1 to obtain the adhesive layer (8) and the surface protective film (8). Various evaluations were performed after 5 days of aging at room temperature.

[0217] The results are shown in Tables 1 and 2.

[0218] [Example 9] A urethane-based adhesive composition (9) was obtained by diluting 100 parts by weight of urethane prepolymer A, 4.0 parts by weight of a polyfunctional isocyanate compound (CORONATE HX (C / HX), manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent, 0.10 parts by weight of KF-615A (manufactured by Shin-Etsu Chemical Co., Ltd.) as an organosilicon compound, 0.30 parts by weight of Elexcel AS110 (manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.) as an antistatic agent, 0.50 parts by weight of Irganox 1010 (manufactured by BASF Co., Ltd.) as an antioxidant, and 0.20 parts by weight of Nikka Octhix Zinc 18% (manufactured by Nippon Kagaku S.A. Co., Ltd.) as a catalyst with ethyl acetate.

[0219] The urethane-based adhesive composition (9) was used instead of the urethane-based adhesive composition (1), and otherwise the same procedure was followed as in Example 1 to obtain the adhesive layer (9) and the surface protective film (9). Various evaluations were performed after 5 days of aging at room temperature.

[0220] The results are shown in Tables 1 and 2.

[0221] [Example 10] A urethane-based adhesive composition (11) was obtained by diluting 100 parts by weight of urethane prepolymer B, 3.0 parts by weight of a polyfunctional isocyanate compound (CORONATE HX (C / HX), manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent, 0.10 parts by weight of KF-615A (manufactured by Shin-Etsu Chemical Co., Ltd.) as an organosilicon compound, 0.30 parts by weight of AS100 (manufactured by Nippon Emulsifier Co., Ltd.) as an antistatic agent, 0.50 parts by weight of Irganox1010 (manufactured by BASF Co., Ltd.) as an antioxidant, and 0.20 parts by weight of Nikka Octhix Zinc 18% (manufactured by Nippon Chemical Industry Co., Ltd.) as a catalyst with ethyl acetate to a total solid content of 50% by weight.

[0222] The urethane-based adhesive composition (10) was used instead of the urethane-based adhesive composition (1), and otherwise the same procedure was followed as in Example 1 to obtain an adhesive layer (10) and a surface protective film (10). Various evaluations were performed after 5 days of aging at room temperature.

[0223] The results are shown in Tables 1 and 2.

[0224] [Example 11] The composition of the polyols is as follows: PREMINOL S3011 (manufactured by Asahi Glass Co., Ltd., Mn=10000): 85 parts by weight; SANNIX GP3000 (manufactured by Sanyo Chemical Co., Ltd., Mn=3000): 13 parts by weight; SANNIX GP1000 (manufactured by Sanyo Chemical Co., Ltd., Mn=1000): 2 parts by weight; CORONATE HX (C / HX), a polyfunctional isocyanate compound (manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent: 14.6 parts by weight; and NACEM as a catalyst. Iron (III) (manufactured by Nippon Chemical Industries, Ltd.): 0.12 parts by weight, KF-354L (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) as an organosilicon compound: 0.10 parts by weight, AS100 (manufactured by Nippon Emulsifier Co., Ltd.) as an antistatic agent: 1.00 parts by weight, were diluted with ethyl acetate to make the total solid content 35% by weight, and a urethane-based adhesive composition (11) was obtained.

[0225] A urethane-based adhesive composition (11) was applied to a polyester resin substrate (trade name "T100-75S", thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) with a dried thickness of 20 μm. The substrate was cured and dried at a drying temperature of 130°C for 2 minutes to create an adhesive layer (12). Next, a 25 μm thick release liner made of polyester resin (trade name "MRF25", thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) with one side treated with silicone was bonded to the surface of the adhesive layer (11) to obtain a surface protective film (11). The film was then aged at room temperature for 5 days for evaluation.

[0226] The results are shown in Tables 1 and 2.

[0227] [Example 12] The composition of the polyols is as follows: PREMINOL S3011 (manufactured by Asahi Glass Co., Ltd., Mn=10000): 85 parts by weight; SANNIX GP3000 (manufactured by Sanyo Chemical Co., Ltd., Mn=3000): 13 parts by weight; SANNIX GP1000 (manufactured by Sanyo Chemical Co., Ltd., Mn=1000): 2 parts by weight; CORONATE HX (C / HX), a polyfunctional isocyanate compound (manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent: 14.6 parts by weight; and NACEM as a catalyst. Iron (III) (manufactured by Nippon Kagaku Sangyo Co., Ltd.): 0.12 parts by weight, KF-640 (manufactured by Shin-Etsu Chemical Co., Ltd.) as an organosilicon compound: 0.10 parts by weight, AS100 (manufactured by Nippon Emulsifier Co., Ltd.) as an antistatic agent: 1.00 parts by weight, were diluted with ethyl acetate to make the total solid content 35% by weight, and a urethane-based adhesive composition (12) was obtained.

[0228] The same procedure as in Example 11 was followed, except that a urethane-based adhesive composition (12) was used instead of the urethane-based adhesive composition (11) to obtain an adhesive layer (12) and a surface protective film (12). Various evaluations were performed after 5 days of aging at room temperature.

[0229] The results are shown in Tables 1 and 2.

[0230] [Example 13] The composition of the polyols is as follows: PREMINOL S3011 (manufactured by Asahi Glass Co., Ltd., Mn=10000): 85 parts by weight; SANNIX GP3000 (manufactured by Sanyo Chemical Co., Ltd., Mn=3000): 13 parts by weight; SANNIX GP1000 (manufactured by Sanyo Chemical Co., Ltd., Mn=1000): 2 parts by weight; CORONATE HX (C / HX), a polyfunctional isocyanate compound (manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent: 14.6 parts by weight; and NACEM as a catalyst. Iron (III) (manufactured by Nippon Kagaku Sangyo Co., Ltd.): 0.12 parts by weight, X-22-4515 (manufactured by Shin-Etsu Chemical Co., Ltd.) as an organosilicon compound: 0.10 parts by weight, AS100 (manufactured by Nippon Emulsifier Co., Ltd.) as an antistatic agent: 1.00 parts by weight, were diluted with ethyl acetate to make the total solid content 35% by weight, and a urethane-based adhesive composition (13) was obtained.

[0231] The same procedure as in Example 11 was followed, except that a urethane-based adhesive composition (13) was used instead of the urethane-based adhesive composition (11) to obtain an adhesive layer (13) and a surface protective film (13). Various evaluations were performed after 5 days of aging at room temperature.

[0232] The results are shown in Tables 1 and 2.

[0233] [Example 14] The composition of the polyols is as follows: PREMINOL S3011 (manufactured by Asahi Glass Co., Ltd., Mn=10000): 85 parts by weight; SANNIX GP3000 (manufactured by Sanyo Chemical Co., Ltd., Mn=3000): 13 parts by weight; SANNIX GP1000 (manufactured by Sanyo Chemical Co., Ltd., Mn=1000): 2 parts by weight; CORONATE HX (C / HX), a polyfunctional isocyanate compound (manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent: 14.6 parts by weight; and NACEM as a catalyst. Iron (III) (manufactured by Nippon Kagaku Sangyo Co., Ltd.): 0.12 parts by weight, KF-6001 (manufactured by Shin-Etsu Chemical Co., Ltd.) as an organosilicon compound: 0.10 parts by weight, AS100 (manufactured by Nippon Emulsifier Co., Ltd.) as an antistatic agent: 1.00 parts by weight, were diluted with ethyl acetate to make the total solid content 35% by weight, and a urethane-based adhesive composition (14) was obtained.

[0234] The same procedure as in Example 11 was followed, except that a urethane-based adhesive composition (14) was used instead of the urethane-based adhesive composition (11) to obtain an adhesive layer (14) and a surface protective film (14). Various evaluations were performed after 5 days of aging at room temperature.

[0235] The results are shown in Tables 1 and 2.

[0236] [Example 15] The composition of the polyols is as follows: PREMINOL S3011 (manufactured by Asahi Glass Co., Ltd., Mn=10000): 85 parts by weight; SANNIX GP3000 (manufactured by Sanyo Chemical Co., Ltd., Mn=3000): 13 parts by weight; SANNIX GP1000 (manufactured by Sanyo Chemical Co., Ltd., Mn=1000): 2 parts by weight; CORONATE HX (C / HX), a polyfunctional isocyanate compound (manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent: 14.6 parts by weight; and NACEM as a catalyst. Iron (III) (manufactured by Nippon Kagaku Sangyo Co., Ltd.): 0.12 parts by weight, X-22-4272 (manufactured by Shin-Etsu Chemical Co., Ltd.) as an organosilicon compound: 0.10 parts by weight, AS100 (manufactured by Nippon Emulsifier Co., Ltd.) as an antistatic agent: 1.00 parts by weight, were diluted with ethyl acetate to a total solid content of 35% by weight, and a urethane-based adhesive composition (15) was obtained.

[0237] The same procedure as in Example 11 was followed, except that a urethane-based adhesive composition (15) was used instead of the urethane-based adhesive composition (11) to obtain an adhesive layer (15) and a surface protective film (15). Various evaluations were performed after 5 days of aging at room temperature.

[0238] The results are shown in Tables 1 and 2.

[0239] [Example 16] The composition of the polyols is as follows: PREMINOL S3011 (manufactured by Asahi Glass Co., Ltd., Mn=10000): 85 parts by weight; SANNIX GP3000 (manufactured by Sanyo Chemical Co., Ltd., Mn=3000): 13 parts by weight; SANNIX GP1000 (manufactured by Sanyo Chemical Co., Ltd., Mn=1000): 2 parts by weight; CORONATE HX (C / HX), a polyfunctional isocyanate compound (manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent: 14.6 parts by weight; and NACEM as a catalyst. Iron (III) (manufactured by Nippon Chemical Industries, Ltd.): 0.12 parts by weight, KF-615A (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) as an organosilicon compound: 0.10 parts by weight, AS100 (manufactured by Nippon Emulsifier Co., Ltd.) as an antistatic agent: 1.00 parts by weight, were diluted with ethyl acetate to make the total solid content 35% by weight, and a urethane-based adhesive composition (16) was obtained.

[0240] The same procedure as in Example 11 was followed, except that a urethane-based adhesive composition (16) was used instead of the urethane-based adhesive composition (11) to obtain an adhesive layer (16) and a surface protective film (16). Various evaluations were performed after 5 days of aging at room temperature.

[0241] The results are shown in Tables 1 and 2.

[0242] [Example 17] The composition of the polyols is as follows: PREMINOL S3011 (manufactured by Asahi Glass Co., Ltd., Mn=10000): 85 parts by weight; SANNIX GP3000 (manufactured by Sanyo Chemical Co., Ltd., Mn=3000): 13 parts by weight; SANNIX GP1000 (manufactured by Sanyo Chemical Co., Ltd., Mn=1000): 2 parts by weight; CORONATE HX (C / HX), a polyfunctional isocyanate compound (manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent: 14.6 parts by weight; and NACEM as a catalyst. Iron (III) (manufactured by Nippon Chemical Industries, Ltd.): 0.12 parts by weight, KF-615A (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) as an organosilicon compound: 0.10 parts by weight, AS100 (manufactured by Nippon Emulsifier Co., Ltd.) as an antistatic agent: 3.00 parts by weight, were diluted with ethyl acetate to make the total solid content 35% by weight, and a urethane-based adhesive composition (17) was obtained.

[0243] The same procedure as in Example 11 was followed, except that a urethane-based adhesive composition (17) was used instead of the urethane-based adhesive composition (11) to obtain an adhesive layer (17) and a surface protective film (17). Various evaluations were performed after 5 days of aging at room temperature.

[0244] The results are shown in Tables 1 and 2.

[0245] [Example 18] The composition of the polyols is as follows: PREMINOL S3011 (manufactured by Asahi Glass Co., Ltd., Mn=10000): 85 parts by weight; SANNIX GP3000 (manufactured by Sanyo Chemical Co., Ltd., Mn=3000): 13 parts by weight; SANNIX GP1000 (manufactured by Sanyo Chemical Co., Ltd., Mn=1000): 2 parts by weight; CORONATE HX (C / HX), a polyfunctional isocyanate compound (manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent: 14.6 parts by weight; and NACEM as a catalyst. Iron (III) (manufactured by Nippon Kagaku Sangyo Co., Ltd.): 0.12 parts by weight, KF-615A (manufactured by Shin-Etsu Chemical Co., Ltd.) as an organosilicon compound: 0.10 parts by weight, and ElexcelAS110 (manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.) as an antistatic agent: 1.00 parts by weight, were diluted with ethyl acetate to make the total solid content 35% by weight, and a carbamate-based adhesive composition (18) was obtained.

[0246] The same procedure as in Example 11 was followed, except that a urethane-based adhesive composition (18) was used instead of the urethane-based adhesive composition (11) to obtain an adhesive layer (18) and a surface protective film (18). Various evaluations were performed after 5 days of aging at room temperature.

[0247] The results are shown in Tables 1 and 2.

[0248] [Comparative Example 1] A urethane-based adhesive composition (C1) was obtained by diluting 100 parts by weight of urethane prepolymer A, 4.0 parts by weight of a polyfunctional isocyanate compound (CORONATE HX (C / HX), manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent, 0.50 parts by weight of Irganox 1010 (manufactured by BASF Co., Ltd.) as an antioxidant, and 0.20 parts by weight of Nikka Octhix Zinc 18% (manufactured by Nippon Chemical Industry Co., Ltd.) as a catalyst with ethyl acetate to a total solid content of 50% by weight.

[0249] The urethane-based adhesive composition (C1) was used instead of the urethane-based adhesive composition (1), and otherwise the same procedure was followed as in Example 1 to obtain an adhesive layer (C1) and a surface protective film (C1). Various evaluations were performed after 5 days of aging at room temperature.

[0250] The results are shown in Tables 1 and 2.

[0251] [Comparative Example 2] A urethane-based adhesive composition (C2) was obtained by diluting 100 parts by weight of urethane prepolymer A, 4.0 parts by weight of a polyfunctional isocyanate compound (CORONATE HX (C / HX), manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent, 1.00 parts by weight of Megaface F-477 (manufactured by DIC Co., Ltd.) as a fluorine compound, 0.50 parts by weight of Irganox 1010 (manufactured by BASF Co., Ltd.) as an antioxidant, and 0.20 parts by weight of Nikka Octhix Zinc 18% (manufactured by Nippon Chemical Industry Co., Ltd.) as a catalyst with ethyl acetate to achieve a total solid content of 50% by weight.

[0252] The urethane-based adhesive composition (C2) was used instead of the urethane-based adhesive composition (1), and otherwise the same procedure was followed as in Example 1 to obtain an adhesive layer (C2) and a surface protective film (C2). Various evaluations were performed after 5 days of aging at room temperature.

[0253] The results are shown in Tables 1 and 2.

[0254] [Comparative Example 3] A urethane-based adhesive composition (C3) was obtained by diluting 100 parts by weight of urethane prepolymer A, 4.0 parts by weight of a polyfunctional isocyanate compound (CORONATE HX (C / HX), manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent, 0.30 parts by weight of CIL312 (manufactured by Japan Carlit Co., Ltd.) as an antistatic agent, 0.50 parts by weight of Irganox1010 (manufactured by BASF Co., Ltd.) as an antioxidant, and 0.20 parts by weight of Nikka Octhix Zinc 18% (manufactured by Nippon Chemical Industry Co., Ltd.) as a catalyst with ethyl acetate to achieve a total solid content of 50% by weight.

[0255] The urethane-based adhesive composition (C3) was used instead of the urethane-based adhesive composition (1), and otherwise the same procedure was followed as in Example 1 to obtain an adhesive layer (C3) and a surface protective film (C3). Various evaluations were performed after 5 days of aging at room temperature.

[0256] The results are shown in Tables 1 and 2.

[0257] [Comparative Example 4] A urethane-based adhesive composition (C4) was obtained by diluting 100 parts by weight of urethane prepolymer A, 4.0 parts by weight of a polyfunctional isocyanate compound (CORONATE HX (C / HX), manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent, 0.50 parts by weight of KF-615A (manufactured by Shin-Etsu Chemical Co., Ltd.) as an organosilicon compound, 0.30 parts by weight of AS100 (manufactured by Nippon Emulsifier Co., Ltd.) as an antistatic agent, 0.50 parts by weight of Irganox 1010 (manufactured by BASF Co., Ltd.) as an antioxidant, and 0.20 parts by weight of Nikka Octhix Zinc 18% (manufactured by Nippon Chemical Industry Co., Ltd.) as a catalyst with ethyl acetate to a total solid content of 50% by weight.

[0258] The urethane-based adhesive composition (C4) was used instead of the urethane-based adhesive composition (1), and otherwise the same procedure was followed as in Example 1 to obtain an adhesive layer (C4) and a surface protective film (C4). Various evaluations were performed after 5 days of aging at room temperature.

[0259] The results are shown in Tables 1 and 2.

[0260] [Comparative Example 5] A polyol containing three hydroxyl groups, PREMINOL S3011 (manufactured by Asahi Glass Co., Ltd., Mn=10000), was diluted with ethyl acetate to obtain a urethane-based adhesive composition (C5) with a total solid content of 35% by weight. The composition consisted of 85 parts by weight of PREMINOL S3011 (manufactured by Asahi Glass Co., Ltd., Mn=1000), 13 parts by weight of SANNIX GP3000 (manufactured by Sanyo Chemical Co., Ltd., Mn=3000), 2 parts by weight of SANNIX GP1000 (manufactured by Sanyo Chemical Co., Ltd., Mn=1000), 14.6 parts by weight of a polyfunctional isocyanate compound (CORONATE HX (C / HX), manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent, and 0.12 parts by weight of NACEM Iron (III) (manufactured by Nippon Chemical Industry Co., Ltd.) as a catalyst.

[0261] The same procedure as in Example 11 was followed, except that a urethane-based adhesive composition (C5) was used instead of the urethane-based adhesive composition (11) to obtain an adhesive layer (C5) and a surface protective film (C5). Various evaluations were performed after 5 days of aging at room temperature.

[0262] The results are shown in Tables 1 and 2.

[0263] [Comparative Example 6] A polyol containing three hydroxyl groups, PREMINOL S3011 (manufactured by Asahi Glass Co., Ltd., Mn=10000), was diluted with ethyl acetate to obtain a urethane-based adhesive composition (C6) with a total solid content of 35% by weight. The composition consisted of 85 parts by weight of PREMINOL S3011 (manufactured by Asahi Glass Co., Ltd., Mn=1000), 13 parts by weight of SANNIX GP3000 (manufactured by Sanyo Chemical Co., Ltd., Mn=3000), 2 parts by weight of SANNIX GP1000 (manufactured by Sanyo Chemical Co., Ltd., Mn=1000), 14.6 parts by weight of a polyfunctional isocyanate compound (CORONATE HX (C / HX), manufactured by Nippon Polyurethane Co., Ltd. ... Chemical Co., Ltd.), 13 parts by weight of a polyol containing three hydroxyl groups (SANNIX GP3000, manufactured by Sanyo Chemical Co., Ltd., Mn=30000), 13 parts by weight of a polyol containing three hydroxyl groups (SANNIX GP10000, manufactured by Sanyo Chemical Co., Ltd., Mn=10000), 14.6 parts by weight of a polyfunctional isocyanate compound (CORONATE HX (C / HX), manufactured by Nippon Polyurethane Co., Ltd.), 14.6 parts by weight of a polyfunctional isocyanate compound (CORONATE HX (C / HX), 14.6 parts by weight of a polyfunctional isocyanate

[0264] The urethane-based adhesive composition (C6) was used instead of the urethane-based adhesive composition (11), and otherwise the same procedure was followed as in Example 11 to obtain an adhesive layer (C6) and a surface protective film (C6). Various evaluations were performed after 5 days of aging at room temperature.

[0265] The results are shown in Tables 1 and 2.

[0266] [Comparative Example 7] A polyol containing three hydroxyl groups, PREMINOL S3011 (manufactured by Asahi Glass Co., Ltd., Mn=10000), was diluted with ethyl acetate to obtain a urethane-based adhesive composition (C7) with a total solid content of 35% by weight. The composition consisted of 85 parts by weight of PREMINOL S3011 (manufactured by Asahi Glass Co., Ltd., Mn=1000), 13 parts by weight of SANNIX GP3000 (manufactured by Sanyo Chemical Co., Ltd., Mn=3000), 2 parts by weight of SANNIX GP1000 (manufactured by Sanyo Chemical Co., Ltd., Mn=1000), 14.6 parts by weight of a polyfunctional isocyanate compound (CORONATE HX: C / HX, manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent, 0.12 parts by weight of NACEM Iron(III) (manufactured by Nippon Chemical Industry Co., Ltd.) as a catalyst, and 0.30 parts by weight of CIL312 (manufactured by Japan Carlit Co., Ltd.) as an antistatic agent.

[0267] The urethane-based adhesive composition (C7) was used instead of the urethane-based adhesive composition (11), and otherwise the same procedure was followed as in Example 11 to obtain an adhesive layer (C7) and a surface protective film (C7). Various evaluations were performed after 5 days of aging at room temperature.

[0268] The results are shown in Tables 1 and 2.

[0269] [Comparative Example 8] The composition of the polyols is as follows: PREMINOL S3011 (manufactured by Asahi Glass Co., Ltd., Mn=10000): 85 parts by weight; SANNIX GP3000 (manufactured by Sanyo Chemical Co., Ltd., Mn=3000): 13 parts by weight; SANNIX GP1000 (manufactured by Sanyo Chemical Co., Ltd., Mn=1000): 2 parts by weight; CORONATE HX (C / HX), a polyfunctional isocyanate compound (manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent: 14.6 parts by weight; and NACEM as a catalyst. Iron (III) (manufactured by Nippon Kagaku Sangyo Co., Ltd.): 0.12 parts by weight, KF-615A (manufactured by Shin-Etsu Chemical Co., Ltd.) as an organosilicon compound: 0.50 parts by weight, AS100 (manufactured by Nippon Emulsifier Co., Ltd.) as an antistatic agent: 1.00 parts by weight, were diluted with ethyl acetate to make the total solid content 35% by weight, and a urethane-based adhesive composition (C8) was obtained.

[0270] The same procedure as in Example 11 was followed, except that a urethane-based adhesive composition (C8) was used instead of the urethane-based adhesive composition (11) to obtain an adhesive layer (C8) and a surface protective film (C8). Various evaluations were performed after 5 days of aging at room temperature.

[0271] The results are shown in Tables 1 and 2. [Examples 19-36] For each surface protective film (1) to (18) obtained in Examples 1 to 18, the release liner was peeled off and the adhesive layer was pasted to the polarizing plate (manufactured by Nitto Denko Corporation, trade name "TEG1465DUHC") which is an optical component, and an optical component with the surface protective film pasted on was obtained.

[0272] [Examples 37-54] For each surface protective film (1) to (18) obtained in Examples 1 to 18, the release liner was peeled off and the adhesive layer was pasted to the conductive film (manufactured by Nitto Denko Corporation, trade name "ELECRYSTA V270L-TFMP") which is an electronic component, and an electronic component with a surface protective film was obtained.

[0273] Industrial availability The surface protective film of the present invention can be used for any suitable application. Preferably, the surface protective film of the present invention is preferred for use in the fields of optical components and electronic components.

Claims

1. A surface protective film comprising an adhesive layer made of a urethane-based adhesive, This carbamate-based adhesive contains carbamate polymers. This carbamate-based adhesive is formed from a carbamate-based adhesive composition. This urethane-based adhesive composition comprises a base polymer A, an organosilicon compound B, and an ionic compound C. The fluorine content in this adhesive layer is less than 0.15% by weight. The surface free energy of the adhesive layer against diiodomethane is 2.5 mJ / m. 2 ~20.0mJ / m 2 .

2. The surface protective film according to claim 1, wherein, The content of the ionic compound C relative to 100 parts by weight of the base polymer A is 0.01 parts by weight to 2.8 parts by weight.

3. The surface protective film according to claim 1, wherein, The urethane polymer is a prepolymer type urethane polymer. After the adhesive layer is adhered to the glass plate and placed at an ambient temperature of 23°C for 30 minutes, the average peel force when the surface protective film is peeled from the glass plate at a peel angle of 180 degrees and a peel speed of 300 mm / min is defined as adhesive force I. After the adhesive layer is adhered to the glass plate and placed at an ambient temperature of 50°C for 1 day, the average peel force when the surface protective film is peeled from the glass plate at a peel angle of 180 degrees and a peel speed of 300 mm / min is defined as adhesive force II. The rate of increase in adhesion to the glass plate over time, defined as [Adhesive Force II / Adhesive Force I] × 100%, is less than 210%.

4. The surface protective film according to claim 1, wherein, The carbamate polymer is a one-step carbamate polymer. After the adhesive layer is adhered to the glass plate and placed at an ambient temperature of 23°C for 30 minutes, the average peel force when the surface protective film is peeled from the glass plate at a peel angle of 180 degrees and a peel speed of 300 mm / min is defined as adhesive force I. After the adhesive layer is adhered to the glass plate and placed at an ambient temperature of 50°C for 1 day, the average peel force when the surface protective film is peeled from the glass plate at a peel angle of 180 degrees and a peel speed of 300 mm / min is defined as adhesive force II. The rate of increase in adhesion to the glass plate over time, defined as [Adhesive Force II / Adhesive Force I] × 100%, is less than 160%.

5. The surface protective film according to claim 1, wherein, The organosilicon compound B comprises an organosilicon compound having a polyether structure.

6. The surface protective film according to claim 5, wherein, The organosilicon compound having a polyether structure is at least one selected from the group consisting of reactive silicone oils and non-reactive silicone oils with an HLB value of less than 15.

7. An optical component comprising a surface protective film as claimed in any one of claims 1 to 6.

8. An electronic component comprising a surface protective film as claimed in any one of claims 1 to 6.

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