Surface protection films, optical components, and electronic components

Abstract

The present invention discloses a surface protective film, an optical component, and an electronic component, belonging to the technical field of protective films. A urethane adhesive composition comprises at least a urethane prepolymer and an antistatic functional agent; the antistatic functional agent comprises an ionic compound and a surfactant, wherein the addition ratio of the ionic compound to the surfactant satisfies the following: 2 ≤ ionic compound / surfactant ≤ 50; the urethane prepolymer is obtained by reacting a first polyol with an organic polyisocyanate compound, wherein the first polyol comprises a polyether polyol and a polyester polyol, wherein the addition ratio of the polyether polyol to the polyester polyol satisfies the following: 5 ≤ polyether polyol / polyester polyol ≤ 50. The present invention solves the problem of ionic compound precipitation by utilizing a specific addition ratio of the polyether polyol to the polyester polyol. This, in conjunction with the specific addition ratio of the ionic compound to the surfactant, ultimately achieves a balance between low peeling charge voltage and low ion precipitation concentration in the surface protective film.

Description

Technical Field

[0001] The present invention belongs to the technical field of protective films, and in particular relates to a surface protective film, an optical component and an electronic component. Background Art

[0002] In the production of optical and electronic devices, surface protective films serve as a crucial barrier against scratches during processing, assembly, testing, and transportation. Their peelability is crucial. In particular, during the assembly of precision devices like organic EL displays, rapid peeling is often necessary to improve production efficiency. This requires that once the protective film has completed its protective function, it must be able to be peeled cleanly from the substrate interface to avoid residue or damage.

[0003] Currently, the adhesive layer of surface protective films is typically a polyurethane adhesive layer. Due to its excellent reprocessability, surface wetting properties, and optical transparency, it has become the preferred material for protective films for optical and electronic devices. To address the problem of static electricity accumulation during the peeling process, the conventional practice is to add ionic compounds to the adhesive to reduce the surface resistance. However, in actual applications, it has been found that polyurethane adhesives that rely solely on ionic compound modification exhibit significant fluctuations in electrostatic discharge performance under high-speed peeling conditions, resulting in high and unstable peeling voltages.

[0004] Chinese patent publication number CN117210145A discloses an antistatic surface protective film. The film comprises an antistatic agent added to an adhesive composition. The antistatic agent comprises an ionic compound and a surfactant, with the ratio of ionic compound to surfactant satisfying the following equation: 2 < ionic liquid / surfactant < 250. By combining two different antistatic agents, an ionic liquid and a surfactant, in a specific ratio, the invention enables rapid peeling of the protective film and reduces the peeling voltage.

[0005] However, this patent still has some areas for improvement: it does not take into account the problem of ionic compounds precipitating in polyurethane adhesives (precipitation is particularly serious under high temperature and high humidity conditions), and instead may corrode the protected components.

[0006] Therefore, it is urgent to provide a protective film to solve the above problems.

[0007] It should be noted that this part of the present invention only provides background technology related to the present invention and does not necessarily constitute prior art or public known technology. Summary of the Invention

[0008] The present invention provides a surface protection film, an optical component and an electronic component, which at least solve the problems of high peeling voltage and precipitation of ionic compounds in the polyurethane adhesive layer of the surface protection film in the prior art.

[0009] In order to achieve the above-mentioned objectives, in a first aspect, the present invention provides a surface protective film, comprising a carbamate adhesive layer, the carbamate adhesive layer is composed of a carbamate adhesive, the carbamate adhesive is formed by a carbamate adhesive composition, the carbamate adhesive composition at least includes a carbamate prepolymer and an antistatic functional agent; the antistatic functional agent is composed of an ionic compound and a surfactant, and the addition ratio of the ionic compound to the surfactant satisfies: 2≤ionic compound / surfactant≤50; the carbamate prepolymer is obtained by reacting a first polyol and an organic polyisocyanate compound, the first polyol includes a polyether polyol and a polyester polyol, and the addition ratio of the polyether polyol to the polyester polyol satisfies: 5≤polyether polyol / polyester polyol≤50.

[0010] Furthermore, the addition ratio of the ionic compound to the surfactant satisfies: 2≤ionic compound / surfactant≤30; the addition ratio of the polyether polyol to the polyester polyol satisfies: 5≤polyether polyol / polyester polyol≤25.

[0011] Furthermore, the mass ratio of the ionic compound to the polyester polyol is 1:(1-10).

[0012] Furthermore, the crosslinking density of the urethane prepolymer is 76% to 80%.

[0013] Furthermore, the molecular weight of the polyether polyol is 50,000 to 100,000, and the PDI is 5-10.

[0014] Furthermore, the molecular weight of the polyester polyol is 30,000 to 80,000, and the PDI is 5 to 10.

[0015] Furthermore, the equivalent ratio of the NCO group of the organic polyisocyanate compound to the OH group of the first polyol is 1.0 to 2.0 in terms of NCO group / OH group.

[0016] Furthermore, the surface energy of the urethane prepolymer is 38 mN / m to 43 mN / m.

[0017] Furthermore, the surfactant is a fluorine-based additive, specifically at least one selected from the group consisting of fluorine-containing compounds, fluorine-based compounds containing hydroxyl groups, and fluorine-based compounds containing crosslinkable functional groups.

[0018] Furthermore, the ionic compound is a combination of at least one of an onium cation and a metal cation and a fluorine organic anion.

[0019] Furthermore, the content of the antistatic agent is 0.1% or more based on 100% by mass of the urethane adhesive composition.

[0020] Furthermore, the urethane adhesive composition further includes a second polyol and a polyfunctional isocyanate compound.

[0021] Furthermore, after the surface protection film was attached to the glass, when the surface protection film was peeled off at a peeling speed of 15 m / min, the peeling charged voltage was less than 100 V.

[0022] Furthermore, after the surface protection film was attached to the copper foil, the copper foil was tested at 20V for 15 minutes, and no corrosion or yellowing of the copper foil was observed.

[0023] On the other hand, the present invention also provides an optical component having the surface protection film attached thereto.

[0024] On the other hand, the present invention also provides an electronic component having the surface protection film attached thereto.

[0025] The beneficial effects of the present invention are:

[0026] The present invention successfully solves the problem of ionic compounds precipitating in polyurethane adhesives by using a combination of polyether polyol and polyester polyol in the first polyol for preparing the urethane prepolymer and by using a specific addition ratio of the polyether polyol and the polyester polyol. The specific addition ratio of the ionic compound and the surfactant cooperates with each other, and ultimately achieves a balance between low peeling charge voltage and low ion precipitation concentration of the surface protective film. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 A schematic cross-sectional view of a surface protection film according to a preferred embodiment of the present invention;

[0029] Figure 2 This is the XPS spectrum of the surface protection film obtained in Example 1 of the present invention;

[0030] Figure 3 This is the XPS spectrum of the surface protection film obtained in Example 9 of the present invention;

[0031] Figure 4 This is the XPS spectrum of the surface protection film obtained in Comparative Example 4 of the present invention.

[0032] Description of reference numerals:

[0033] 100. Surface protection film; 10. Base material layer; 20. Adhesive layer. DETAILED DESCRIPTION

[0034] In the present invention, unless otherwise specified, directional words such as "up, down, left, right" are generally understood in conjunction with the directions shown in the drawings and actual applications.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0036] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0037] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined to form one or more new numerical ranges, and these numerical ranges should be considered to be specifically disclosed herein. The terms "optional" and "optional" mean that a range may or may not be included (or may or may not be present).

[0038] ≪≪1. Surface protection film≫≫

[0039] The surface protection film according to an embodiment of the present invention includes a urethane-based pressure-sensitive adhesive layer. Any appropriate release liner having releasability may be attached to the adhesive surface of the urethane-based pressure-sensitive adhesive layer, as long as the effects of the present invention are not impaired.

[0040] The surface protection film according to an embodiment of the present invention preferably comprises a substrate layer and a urethane adhesive layer. The substrate layer may be a single layer or two or more layers. The urethane adhesive layer may be a single layer or two or more layers. In addition to the substrate layer and the urethane adhesive layer, the surface protection film of the present invention may further comprise any other appropriate layers, as long as the effects of the present invention are not impaired.

[0041] Figure 1 This is a schematic cross-sectional view of a surface protection film according to a preferred embodiment of the present invention. Surface protection film 100 comprises a substrate layer 10 and an adhesive layer 20. The surface protection film of the present invention may further comprise any other appropriate layer (not shown), such as a release liner, as required.

[0042] For the side of the substrate layer 10 to which the adhesive layer 20 is not attached, in order to form a roll that is easy to unwind, for example, fatty acid amide, polyethyleneimine, long-chain alkyl additives, etc. can be added to the substrate layer for mold release treatment, or a coating layer composed of any appropriate release agent such as silicone, long-chain alkyl, fluorine, etc. can be provided on the substrate layer.

[0043] Examples of release liners that may be provided on the adhesive surface of the urethane-based adhesive layer include release liners obtained by treating the surface of a substrate (liner substrate) such as paper or plastic film with silicone, and release liners obtained by laminating the surface of a substrate (liner substrate) such as paper or plastic film with a polyolefin-based resin.

[0044] Examples of the plastic film serving as the substrate of the release liner include polyethylene film, polypropylene film, polybutylene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, and ethylene-vinyl acetate copolymer film.

[0045] The thickness of the release liner is preferably 1 μm to 500 μm, more preferably 3 μm to 450 μm, further preferably 5 μm to 400 μm, and particularly preferably 10 μm to 300 μm.

[0046] The thickness of the surface protection film according to the embodiment of the present invention can be set to any appropriate thickness depending on the application, and is typically preferably 10 μm to 300 μm, more preferably 15 μm to 250 μm, further preferably 20 μm to 200 μm, and particularly preferably 25 μm to 150 μm.

[0047] ≪1-1. Urethane Adhesive Layer≫

[0048] The urethane adhesive layer is composed of a urethane adhesive. The urethane adhesive is formed from a urethane adhesive composition. That is, the adhesive layer is obtained by forming a urethane adhesive formed from the urethane adhesive composition into a layer.

[0049] Urethane adhesives can be specified as adhesives formed from urethane adhesive compositions. This is because urethane adhesive compositions become urethane adhesives through a cross-linking reaction caused by heating or ultraviolet irradiation, etc. Therefore, it is impossible to directly specify urethane adhesives based on their structure, and this may be impractical ("impossible / impractical"). Therefore, the definition of "formed from a urethane adhesive composition" appropriately specifies urethane adhesives as "articles."

[0050] The thickness of the urethane adhesive layer is preferably 1 μm to 150 μm, more preferably 5 μm to 150 μm, even more preferably 10 μm to 150 μm, even more preferably 20 μm to 150 μm, even more preferably 30 μm to 150 μm, even more preferably 40 μm to 150 μm, even more preferably 50 μm to 150 μm, particularly preferably 60 μm to 150 μm, and most preferably 65 μm to 150 μm. If the thickness of the urethane adhesive layer can be increased as described above, the surface protection film according to an embodiment of the present invention can effectively follow the unevenness of displays with large unevenness, such as organic EL displays, when protecting such displays.

[0051] The urethane adhesive is formed from a urethane adhesive composition. Any appropriate method can be used as long as the effects of the present invention are not impaired. Examples of such methods include: a method in which the urethane adhesive composition is directly applied to any appropriate substrate film (e.g., the substrate layer in a surface protective film according to an embodiment of the present invention) and dried or cured (a direct method); and a method in which a urethane adhesive layer formed on the surface (release surface) of a release liner by applying the urethane adhesive composition and drying or curing the urethane adhesive composition is attached to a substrate film (e.g., the substrate layer in a surface protective film according to an embodiment of the present invention) to transfer the urethane adhesive layer (a transfer method). From the perspective of the anchoring properties of the adhesive layer, the direct method is typically preferred.

[0052] As a method for imparting (representatively, coating) such a urethane-based adhesive layer, various conventionally known methods such as roll coating, gravure coating, reverse coating, slit coating, dip coating, rod coating, roller brushing, spray coating, blade coating, air knife coating, spray coating, comma blade coating, direct coating, and coating using a slot die coater can be appropriately adopted.

[0053] The urethane adhesive composition can be dried under heating as needed (e.g., by heating to approximately 60° C. to 150° C.). For example, ultraviolet rays, lasers, α-rays, β-rays, γ-rays, X-rays, and electron beams can be appropriately used to cure the urethane adhesive composition.

[0054] The urethane-based adhesive composition includes a urethane prepolymer, a second polyol, and a polyfunctional isocyanate compound.

[0055] The weight ratio of the total amount of the urethane prepolymer, the second polyol, and the polyfunctional isocyanate compound in the urethane adhesive composition 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. By adjusting the weight ratio of the total amount of the urethane prepolymer and the second polyol in the urethane adhesive composition within the above range, the surface protection film of the present invention can effectively exhibit the effects of the present invention.

[0056] The equivalent ratio of NCO groups to OH groups in the urethane prepolymer and the polyfunctional isocyanate compound (NCO groups / OH groups) is preferably 1.0 to 2.0, more preferably 1.1 to 1.9, even more preferably 1.2 to 1.8, and particularly preferably 1.2 to 1.7. By adjusting the NCO group / OH group equivalent ratio within this range, the surface protection film according to an embodiment of the present invention exhibits superior wettability and conformability to surface irregularities, even when applied to adherends with relatively large surface irregularities, thereby achieving a sufficiently high adhesion ratio.

[0057] The content of the polyfunctional isocyanate compound in the urethane adhesive composition is preferably 2.5 to 40 parts by weight, more preferably 4 to 30 parts by weight, even more preferably 5 to 20 parts by weight, and particularly preferably 6 to 15 parts by weight, relative to 100 parts by weight of the urethane prepolymer. By adjusting the content of the polyfunctional isocyanate compound within the above range, the surface protection film according to an embodiment of the present invention exhibits improved wettability and conformability to surface irregularities, even when applied to adherends with relatively large surface irregularities, thereby achieving a substantially higher adhesion rate.

[0058] <1-1-1. Urethane Prepolymer>

[0059] The urethane prepolymer is typically a polyurethane polyol, preferably a first polyol, specifically a polyester polyol (p1) and a polyether polyol (p2), which react with an organic polyisocyanate compound (p3) in the presence or absence of a catalyst.

[0060] The urethane prepolymer may be used alone or in combination of two or more.

[0061] The number average molecular weight Mn of the urethane prepolymer is preferably 1,000 to 100,000.

[0062] As the polyester polyol (p1), any appropriate polyester polyol may be used, as long as the effects of the present invention are not impaired. Examples of such polyester polyols (p1) include those obtained by reacting an acid component with a diol component. Examples of the acid component include terephthalic acid, adipic acid, azelaic acid, sebacic acid, phthalic anhydride, isophthalic acid, and trimellitic acid. Examples of the diol component 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, neopentyl glycol, and butylethylpentanediol. Examples of the polyol component include glycerin, trimethylolpropane, and pentaerythritol. Examples of the polyester polyol (p1) include, among others, polyester polyols obtained by ring-opening polymerization of lactones such as polycaprolactone, poly(β-methyl-γ-valerolactone), and polyvalerolactone.

[0063] The molecular weight of the polyester polyol (p1) can range from low to high. The number average molecular weight of the polyester polyol (p1) is preferably 500 to 5000. A number average molecular weight below 500 may increase reactivity, leading to increased gelation. A number average molecular weight exceeding 5000 may decrease reactivity, resulting in reduced cohesiveness of the polyurethane polyol itself.

[0064] As the polyether polyol (p2), any appropriate polyether polyol can be used as long as the effects of the present invention are not impaired. Examples of such polyether polyols (p2) include those obtained by polymerizing ethylene oxide compounds such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran using low molecular weight polyols such as water, propylene glycol, ethylene glycol, glycerin, and trimethylolpropane as initiators. Examples of such polyether polyols (p2) include polyether polyols having two or more functional groups, such as polypropylene glycol, polyethylene glycol, and polybutylene glycol.

[0065] The polyether polyol (p2) can be used in combination with a diol such as ethylene glycol, 1,4-butanediol, neopentyl glycol, butylethylpentanediol, glycerol, trimethylolpropane, or pentaerythritol, or a polyamine such as ethylenediamine, N-aminoethylethanolamine, isophoronediamine, or xylenediamine, as needed.

[0066] As the polyether polyol (p2), only a bifunctional polyether polyol may be used, or a polyether polyol having at least three hydroxyl groups in one molecule may be used partially or entirely.

[0067] As the organic polyisocyanate compound (p3), any appropriate organic polyisocyanate compound can be used within the range not impairing the effects of the present invention. Examples of such organic polyisocyanate compounds (p3) include aromatic polyisocyanates, aliphatic polyisocyanates, aromatic aliphatic polyisocyanates, and alicyclic polyisocyanates.

[0068] Examples of the aromatic polyisocyanate include 1,3-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-toluidine diisocyanate, 2,4,6-toluene triisocyanate, 1,3,5-benzene triisocyanate, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, and 4,4',4"-triphenylmethane triisocyanate.

[0069] Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate.

[0070] Examples of the aromatic aliphatic polyisocyanate include ω,ω′-diisocyanate-1,3-dimethylbenzene, ω,ω′-diisocyanate-1,4-dimethylbenzene, ω,ω′-diisocyanate-1,4-diethylbenzene, 1,4-tetramethylxylylene diisocyanate, and 1,3-tetramethylxylylene diisocyanate.

[0071] Examples of the alicyclic polyisocyanate include 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate, 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4′-methylenebis(cyclohexyl isocyanate), 1,4-bis(isocyanate methyl)cyclohexane, and 1,4-bis(isocyanate methyl)cyclohexane.

[0072] As the organic polyisocyanate compound (p3), a trimethylolpropane adduct, a biuret form after reaction with water, or a trimer having an isocyanurate ring can be used in combination.

[0073] Any appropriate catalyst can be used as a catalyst for producing a urethane prepolymer (typically, polyurethane polyol) as long as the effects of the present invention are not impaired. Examples of such catalysts include tertiary amine compounds and organometallic compounds.

[0074] Examples of the tertiary amine compound include triethylamine, triethylenediamine, and 1,8-diazabicyclo(5,4,0)-undecene-7 (DBU).

[0075] Examples of the organometallic compound include tin compounds and non-tin compounds.

[0076] Examples of the tin compound include dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, dibutyltin dilaurate (DBTDL), dibutyltin diacetate, dibutyltin sulfide, tributyltin sulfide, tributyltin oxide, tributyltin acetate, triethyltin ethoxide, tributyltin ethoxide, dioctyltin oxide, tributyltin chloride, tributyltin trichloroacetate, and 2-ethyltin hexanoate.

[0077] As non-tin compounds, for example, titanium compounds such as dibutyltitanium dichloride, tetrabutyl titanate, butoxytitanium trichloride; lead compounds such as lead oleate, lead 2-ethylhexanoate, lead benzoate, lead naphthenate; iron compounds such as iron 2-ethylhexanoate, iron acetoacetate; cobalt compounds such as cobalt benzoate, cobalt 2-ethylhexanoate; zinc compounds such as zinc naphthenate, zinc 2-ethylhexanoate; and zirconium compounds such as zirconium naphthenate.

[0078] When using a catalyst in the production of urethane prepolymers (typically polyurethane polyols), in systems containing two polyols, polyester polyol (p1) and polyether polyol (p2), gelation and turbidity of the reaction solution are common problems if a single catalyst system is used due to their different reactivities. Therefore, using two catalysts in the production of urethane prepolymers (typically polyurethane polyols) facilitates control of reaction rate and catalyst selectivity, thereby addressing these issues. Examples of such two-catalyst combinations include tertiary amine / organometallic, tin / non-tin, and tin / tin. Tin / tin combinations are preferred, and a combination of dibutyltin dilaurate and tin 2-ethylhexanoate is more preferred. The weight ratio of tin 2-ethylhexanoate to dibutyltin dilaurate is preferably less than 1, more preferably 0.2 to 0.6. A ratio of greater than 1 may lead to gelation due to the balance of catalyst activity.

[0079] When a catalyst is used in producing a urethane prepolymer (typically, polyurethane polyol), the amount of the catalyst used is preferably 0.01% to 1.0% by weight relative to the total amount of the polyester polyol (p1), polyether polyol (p2), and organic polyisocyanate compound (p3).

[0080] When using a catalyst to produce a urethane prepolymer (typically, a polyurethane polyol), the reaction temperature is preferably below 100°C, more preferably 85°C to 95°C. If the temperature exceeds 100°C, it may be difficult to control the reaction rate and crosslinking structure, making it difficult to obtain a urethane prepolymer (typically, a polyurethane polyol) having a desired molecular weight.

[0081] A catalyst may be used when producing a urethane prepolymer (typically, a polyurethane polyol). In this case, the reaction temperature is preferably 100°C or higher, more preferably 110°C or higher. Furthermore, when producing a urethane prepolymer (typically, a polyurethane polyol) without a catalyst, the reaction is preferably carried out for at least 3 hours.

[0082] Examples of methods for producing urethane prepolymers (typically polyurethane polyols) include: 1) placing a polyester polyol (p1), a polyether polyol (p2), a catalyst, and an organic polyisocyanate compound (p3) in a flask; and 2) placing a polyester polyol (p1), a polyether polyol (p2), and a catalyst in a flask and then adding the organic polyisocyanate compound (p3) dropwise. Method 2) is preferred for producing urethane prepolymers (typically polyurethane polyols) in terms of reaction control.

[0083] When producing a urethane prepolymer (typically, a polyurethane polyol), any appropriate solvent may be used within the scope of not impairing the effects of the present invention. Examples of such solvents include methyl ethyl ketone, ethyl acetate, toluene, xylene, and acetone. Among these solvents, ethyl acetate is preferred.

[0084] <1-1-2. Second polyol>

[0085] Examples of the second polyol include polyester polyol, polyether polyol, polycaprolactone polyol, polycarbonate polyol, and castor oil-based polyol. More preferred second polyols are polyester polyol and polyether polyol.

[0086] The polyester polyol can be obtained, for example, by an esterification reaction between a polyol component and an acid component.

[0087] Examples of the polyol component 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, glycerin, trimethylolpropane, pentaerythritol, hexanetriol, and polypropylene glycol.

[0088] Examples of the acid component include succinic acid, methylsuccinic acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,12-dodecanedioic acid, 1,14-tetradecanedioic acid, dimer acid, 2-methyl-1,4-cyclohexanedicarboxylic acid, 2-ethyl-1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, and anhydrides thereof.

[0089] Examples of polyether polyols include those obtained by addition-polymerizing alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide using water, low-molecular-weight polyols (propylene glycol, ethylene glycol, glycerin, trimethylolpropane, pentaerythritol, etc.), bisphenols (bisphenol A, etc.), and dihydroxybenzenes (catechol, resorcinol, hydroquinone, etc.) as initiators. Specific examples include polyethylene glycol, polypropylene glycol, and polybutylene glycol.

[0090] Examples of the polycaprolactone polyol include caprolactone-based polyester diols obtained by ring-opening polymerization of cyclic ester monomers such as ε-caprolactone and σ-valerolactone.

[0091] Examples of the polycarbonate polyol include: polycarbonate polyols obtained by polycondensation of the above-mentioned polyol components with phosgene; polycarbonate polyols obtained by transesterification condensation of the above-mentioned polyol components with carbonic acid diesters such as dimethyl carbonate, diethyl carbonate, dipropyl carbonate, diisopropyl carbonate, dibutyl carbonate, ethylbutyl carbonate, ethylene carbonate, propylene carbonate, diphenyl carbonate, and dibenzyl carbonate; copolymerized polycarbonate polyols obtained by combining two or more of the above-mentioned polyol components; and polycarbonate polyols obtained by esterification of the above-mentioned various polycarbonate polyols with carboxyl group-containing compounds. polycarbonate polyols obtained by etherification reaction of the above-mentioned various polycarbonate polyols with hydroxyl-containing compounds; polycarbonate polyols obtained by transesterification reaction of the above-mentioned various polycarbonate polyols with ester compounds; polycarbonate polyols obtained by transesterification reaction of the above-mentioned various polycarbonate polyols with hydroxyl-containing compounds; polyester polycarbonate polyols obtained by condensation reaction of the above-mentioned various polycarbonate polyols with dicarboxylic acid compounds; copolyether polycarbonate polyols obtained by copolymerization of the above-mentioned various polycarbonate polyols with alkylene oxides.

[0092] Examples of castor oil-based polyols include those obtained by reacting castor oil fatty acids with the above-mentioned polyol components. Specifically, examples include those obtained by reacting castor oil fatty acids with polypropylene glycol.

[0093] The second polyol comprises a polyol (A1) having a number average molecular weight Mn of 5000 to 20000 and a polyol (A2) having a number average molecular weight Mn of 300 to 4999. The effects of the present invention can be further exhibited by comprising a polyol (A1) having a number average molecular weight Mn of 5000 to 20000 and a polyol (A2) having a number average molecular weight Mn of 300 to 4999.

[0094] The polyol (A1) may be one kind or two or more kinds.

[0095] The polyol (A2) may be one kind or two or more kinds.

[0096] In order to further demonstrate the effects of the present invention, the total content of the polyol (A1) and the polyol (A2) in the second polyol is preferably 80% by weight to 100% by weight, more preferably 90% by weight to 100% by weight, further preferably 95% by weight to 100% by weight, particularly preferably 98% by weight to 100% by weight, and most preferably substantially 100% by weight.

[0097] The number average molecular weight Mn of the polyol (A1) is 5,000 to 20,000, preferably 6,000 to 18,000, more preferably 7,000 to 16,000, further preferably 8,000 to 15,000, and particularly preferably 9,000 to 14,000. When the number average molecular weight Mn of the polyol (A1) is within this range, the effects of the present invention can be more effectively exhibited.

[0098] The number average molecular weight Mn of the polyol (A2) is 300 to 4999, preferably 350 to 4500, more preferably 400 to 4000, further preferably 500 to 3800, and particularly preferably 700 to 3500. When the number average molecular weight Mn of the polyol (A2) is within this range, the effects of the present invention can be more effectively exhibited.

[0099] The weight ratio of polyol (A1) to polyol (A2) is preferably 1.0 ≤ (A1 / A2) ≤ 3.5, more preferably 1.0 ≤ (A1 / A2) ≤ 3.0, further preferably 1.0 ≤ (A1 / A2) ≤ 2.5, and particularly preferably 1.0 ≤ (A1 / A2) ≤ 2.0. When the weight ratio of polyol (A1) to polyol (A2) is within this range, the effects of the present invention are more effectively exhibited.

[0100] The polyol (A1) preferably has 3 to 6 OH groups, more preferably 3 to 5 OH groups, further preferably 3 to 4 OH groups, and particularly preferably 3 OH groups, in order to further exhibit the effects of the present invention.

[0101] In order to further demonstrate the effects of the present invention, the polyol (A1) preferably contains a triol having three OH groups in an amount of 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 substantially 100% by weight.

[0102] The polyol (A2) preferably has 3 to 6 OH groups, more preferably 3 to 5 OH groups, further preferably 3 to 4 OH groups, and particularly preferably 3 OH groups, in order to further exhibit the effects of the present invention.

[0103] In order to further demonstrate the effects of the present invention, the polyol (A2) preferably contains a triol having three OH groups in an amount of 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 substantially 100% by weight.

[0104] <1-1-3. Polyfunctional isocyanate compound>

[0105] The polyfunctional isocyanate compound may be used alone or in combination of two or more.

[0106] As the polyfunctional isocyanate compound, any appropriate polyfunctional isocyanate compound that can be used for urethanization reaction can be used. Examples of such polyfunctional isocyanate compounds include polyfunctional aliphatic isocyanate compounds, polyfunctional alicyclic isocyanates, and polyfunctional aromatic isocyanate compounds.

[0107] Examples of the polyfunctional aliphatic isocyanate compound include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate.

[0108] Examples of the polyfunctional alicyclic isocyanate compound include 1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylenediisocyanate, hydrogenated toluene diisocyanate, and hydrogenated tetramethylxylylenediisocyanate.

[0109] Examples of the polyfunctional aromatic diisocyanate compound include phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 2,2′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-toluidine diisocyanate, 4,4′-diphenyl ether diisocyanate, 4,4′-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, and xylylenediisocyanate.

[0110] Examples of the polyfunctional isocyanate compound B include trimethylolpropane adducts of the various polyfunctional isocyanate compounds described above, biuret forms after reaction with water, and trimers having an isocyanurate ring.

[0111] <1-1-4. Other ingredients>

[0112] In addition to the urethane prepolymer, the second polyol, and the polyfunctional isocyanate compound, the urethane adhesive composition may further include any other appropriate components within the scope that does not impair the effects of the present invention. Examples of such other components include: resin components other than the urethane prepolymer and the second polyol, crosslinking agents other than the polyfunctional isocyanate compound, crosslinking retarders, ionic compounds, fluorine-based additives, silicone-based additives, fatty acid esters, tackifiers, inorganic fillers, organic fillers, metal powders, pigments, foils, softeners, antioxidants, conductive agents, ultraviolet absorbers, antioxidants, light stabilizers, surface lubricants, leveling agents, corrosion inhibitors, heat stabilizers, polymerization inhibitors, lubricants, solvents, and catalysts.

[0113] 〔Ionic compounds〕

[0114] If an ionic compound is contained as another component, the antistatic performance of the surface protection film according to the embodiment of the present invention can be improved.

[0115] As for the content ratio of the ionic compound, any appropriate content ratio can be adopted within the range that does not impair the effects of the present invention. In terms of further improving the antistatic performance of the surface protection film of the present invention, the content ratio of the ionic compound relative to the total amount of the urethane prepolymer and the second polyol is preferably 0.05% by weight or more, more preferably 0.10% by weight to 50% by weight, further preferably 0.20% by weight to 30% by weight, particularly preferably 0.30% by weight to 10% by weight, and most preferably 0.50% by weight to 3% by weight. If the content ratio of the ionic compound relative to the total amount of the urethane prepolymer and the second polyol is within the above range, the antistatic performance of the surface protection film of the present invention can be further improved. If the content ratio of the ionic compound relative to the total amount of the urethane prepolymer and the second polyol is less than the above range, the surface protection film of the present invention may not be given sufficient antistatic performance. If the content ratio of the ionic compound relative to the total amount of the urethane prepolymer and the second polyol is greater than the above range, it may increase contamination of the adherend.

[0116] As the ionic compound, any appropriate ionic compound can be adopted within the range not impairing the effects of the present invention. The ionic compound may be one type or two or more types.

[0117] As the ionic compound, in terms of being able to better demonstrate the effects of the present invention, it is preferably an ionic compound containing at least one selected from onium cations and metal cations and a fluorinated organic anion, or an ionic group-containing silicone oligomer. In terms of being able to further improve the appearance of the adhesive layer, it is more preferably an ionic compound containing at least one selected from onium cations and metal cations and a fluorinated organic anion.

[0118] The ionic compound may be an ionic liquid. An ionic liquid refers to a molten salt (ionic compound) that is liquid at 25°C.

[0119] As the ionic group-containing silicone oligomer, any appropriate ionic group-containing silicone oligomer may be used within the range not impairing the effects of the present invention. Examples of the ionic group-containing silicone oligomer include "X-40-2450" manufactured by Shin-Etsu Chemical Co., Ltd.

[0120] As the onium cation, any appropriate onium cation can be used within the scope of not impairing the effects of the present invention. In terms of being able to further demonstrate the effects of the present invention, such an onium cation is preferably at least one selected from ammonium cations (nitrogen-containing onium cations), sulfonium cations (sulfur-containing onium cations), and phosphonium-containing onium cations (phosphonium cations), and is more preferably an ammonium cation.

[0121] As the metal cation, any appropriate metal cation can be adopted within the scope of not impairing the effect of the present invention. In order to further demonstrate the effect of the present invention, as such a metal cation, preferably an alkali metal cation such as Li cation, Na cation, K cation.

[0122] As the fluorinated organic anion, any appropriate fluorinated organic anion can be adopted within the range not impairing the effects of the present invention. The fluorinated organic anion may be completely fluorinated (perfluorinated) or partially fluorinated.

[0123] Examples of such fluorinated organic anions include fluorinated arylsulfonates, perfluoroalkanesulfonates, bis(fluorosulfonyl)imides, bis(perfluoroalkanesulfonyl)imides, cyanoperfluoroalkanesulfonylamides, bis(cyanoperfluoroalkanesulfonyl methides, cyano-bis(perfluoroalkanesulfonyl)methides, tris(perfluoroalkanesulfonyl)methides, trifluoroacetates, perfluoroalkyls, tris(perfluoroalkanesulfonyl)methides, and (perfluoroalkanesulfonyl)trifluoroacetamide.

[0124] Among these fluorinated organic anions, perfluoroalkylsulfonates, bis(fluorosulfonyl)imides, and bis(perfluoroalkylsulfonyl)imides are preferred in terms of being able to more effectively exhibit the effects of the present invention; more specifically, for example, trifluoromethanesulfonate, pentafluoroethanesulfonate, heptafluoropropanesulfonate, nonafluorobutanesulfonate, bis(fluorosulfonyl)imide, and bis(trifluoromethanesulfonyl)imide; bis(fluorosulfonyl)imide and bis(trifluoromethanesulfonyl)imide are preferred.

[0125] As the ionic compound, an ionic compound composed of an onium cation and a fluorinated organic anion is more preferable in that the effects of the present invention can be more effectively exhibited.

[0126] The onium cation preferably has at least one structure selected from the group consisting of the structures represented by general formulae (1) to (4).

[0127]

Chemical Formula 1

[0128] In the general formula (1), Ra represents a hydrocarbon group having 4 to 20 carbon atoms, which may contain a heteroatom, and Rb and Rc are the same or different and represent hydrogen or a hydrocarbon group having 1 to 16 carbon atoms, which may contain a heteroatom. In the case where the nitrogen atom contains a double bond, Rc is absent.

[0129] In the general formula (2), Rd represents a hydrocarbon group having 2 to 20 carbon atoms, which may contain a heteroatom; Re, Rf, and Rg are the same or different and represent hydrogen or a hydrocarbon group having 1 to 16 carbon atoms, which may contain a heteroatom.

[0130] In the general formula (3), Rh represents a hydrocarbon group having 2 to 20 carbon atoms, which may contain a heteroatom; Ri, Rj, and Rk are the same or different and represent hydrogen or a hydrocarbon group having 1 to 16 carbon atoms, which may contain a heteroatom.

[0131] In the general formula (4), Z represents a nitrogen atom, a sulfur atom, or a phosphorus atom, and Rl, Rm, Rn, and Ro are the same or different and represent a hydrocarbon group having 1 to 20 carbon atoms, which may contain a heteroatom. When Z represents a sulfur atom, Ro is absent.

[0132] Examples of the cationic structure represented by the general formula (1) include a pyridinium cationic structure, a pyrrolidinium cationic structure, a piperidinium cationic structure, a cationic structure having a pyrroline skeleton, and a cationic structure having a pyrrole skeleton.

[0133] Specific examples of the cation represented by the general formula (1) include pyridinium cations such as 1-ethylpyridinium cation, 1-butylpyridinium cation, 1-hexylpyridinium cation, 1-ethyl-3-methylpyridinium cation, 1-butyl-3-methylpyridinium cation, 1-hexyl-3-methylpyridinium cation, 1-butyl-4-methylpyridinium cation, 1-octyl-4-methylpyridinium cation, 1-butyl-3,4-dimethylpyridinium cation, and 1,1-dimethylpyrrolidinium cation; 1-ethyl-1-methylpyrrolidinium cation, 1- 1-methyl-1-propylpyrrolidinium cation, 1-methyl-1-butylpyrrolidinium cation, 1-methyl-1-pentylpyrrolidinium cation, 1-methyl-1-hexylpyrrolidinium cation, 1-methyl-1-heptylpyrrolidinium cation, 1-ethyl-1-propylpyrrolidinium cation, 1-ethyl-1-butylpyrrolidinium cation, 1-ethyl-1-pentylpyrrolidinium cation, 1-ethyl-1-hexylpyrrolidinium cation, 1-ethyl-1-heptylpyrrolidinium cation, 1,1-dipropylpyrrolidinium cation, 1-propyl-1-butylpyrrolidinium cation ion, 1,1-dibutylpyrrolidinium cation and other pyrrolidinium cations; 1-propylpiperidinium cation, 1-pentylpiperidinium cation, 1-methyl-1-ethylpiperidinium cation, 1-methyl-1-propylpiperidinium cation, 1-methyl-1-butylpiperidinium cation, 1-methyl-1-pentylpiperidinium cation, 1-methyl-1-hexylpiperidinium cation, 1-methyl-1-heptylpiperidinium cation, 1-ethyl-1-propylpiperidinium cation, 1-ethyl-1-butylpiperidinium cation, 1-ethyl-1-pentylpiperidinium cation, 1-ethyl- Piperidinium cations such as 1-hexylpiperidinium cation, 1-ethyl-1-heptylpiperidinium cation, 1-propyl-1-butylpiperidinium cation, 1,1-dimethylpiperidinium cation, 1,1-dipropylpiperidinium cation, and 1,1-dibutylpiperidinium cation; 2-methyl-1-pyrrolinium cation; 1-ethyl-2-phenylindole cation; 1,2-dimethylindole cation; 1-ethylcarbazole cation; cations further having at least one selected from a vinyl group (CH2=CH- group) and an allyl group (CH2=CH-CH2- group), etc.

[0134] Among them, in terms of further exhibiting the effects of the present invention, preferably mentioned are pyridinium cations such as 1-ethylpyridinium cation, 1-butylpyridinium cation, 1-hexylpyridinium cation, 1-ethyl-3-methylpyridinium cation, 1-butyl-3-methylpyridinium cation, 1-hexyl-3-methylpyridinium cation, 1-butyl-4-methylpyridinium cation, and 1-octyl-4-methylpyridinium cation; 1-ethyl-1-methylpyrrolidinium cation, 1-methyl-1-propylpyrrolidinium cation, 1-methyl- Pyrrolidinium cations such as 1-butylpyrrolidinium cation, 1-methyl-1-pentylpyrrolidinium cation, 1-methyl-1-hexylpyrrolidinium cation, 1-methyl-1-heptylpyrrolidinium cation, 1-ethyl-1-propylpyrrolidinium cation, 1-ethyl-1-butylpyrrolidinium cation, 1-ethyl-1-pentylpyrrolidinium cation, 1-ethyl-1-hexylpyrrolidinium cation, and 1-ethyl-1-heptylpyrrolidinium cation; 1-methyl-1-ethylpiperidinium cation, 1-methyl-1-propylpiperidinium cation; ion, 1-methyl-1-butylpiperidinium cation, 1-methyl-1-pentylpiperidinium cation, 1-methyl-1-hexylpiperidinium cation, 1-methyl-1-heptylpiperidinium cation, 1-ethyl-1-propylpiperidinium cation, 1-ethyl-1-butylpiperidinium cation, 1-ethyl-1-pentylpiperidinium cation, 1-ethyl-1-hexylpiperidinium cation, 1-ethyl-1-heptylpiperidinium cation, 1-propyl-1-butylpiperidinium cation; these cations further have a vinyl group (C The cations are preferably cations having at least one of a vinyl group (CH2=CH- group) and an allyl group (CH2=CH-CH2- group), more preferably a 1-hexylpyridinium cation, a 1-ethyl-3-methylpyridinium cation, a 1-butyl-3-methylpyridinium cation, a 1-octyl-4-methylpyridinium cation, a 1-methyl-1-propylpyrrolidinium cation, a 1-methyl-1-propylpiperidinium cation, or cations in which these cations further have at least one selected from a vinyl group (CH2=CH- group) and an allyl group (CH2=CH-CH2- group).

[0135] Examples of the cationic structure represented by the general formula (2) include an imidazolium cationic structure, a tetrahydropyridinium cationic structure, and a dihydropyridinium cationic structure.

[0136] Specific examples of the cation represented by the general formula (2) include 1,3-dimethylimidazolium cation, 1,3-diethylimidazolium cation, 1-ethyl-3-methylimidazolium cation, 1-butyl-3-methylimidazolium cation, 1-hexyl-3-methylimidazolium cation, 1-octyl-3-methylimidazolium cation, 1-decyl-3-methylimidazolium cation, 1-dodecyl-3-methylimidazolium cation, imidazolium cations such as 1-tetradecyl-3-methylimidazolium cation, 1,2-dimethyl-3-propylimidazolium cation, 1-ethyl-2,3-dimethylimidazolium cation, 1-butyl-2,3-dimethylimidazolium cation, 1-hexyl-2,3-dimethylimidazolium cation; 1,3-dimethyl-1,4,5,6-tetrahydropyridinium cation, 1,2,3-trimethyl -1,4,5,6-tetrahydropyridinium cation, 1,2,3,4-tetramethyl-1,4,5,6-tetrahydropyridinium cation, 1,2,3,5-tetramethyl-1,4,5,6-tetrahydropyridinium cation and other tetrahydropyridinium cations; 1,3-dimethyl-1,4-dihydropyridinium cation, 1,3-dimethyl-1,6-dihydropyridinium cation, 1,2,3-trimethyl-1,4-dihydro Dihydropyridinium cations such as pyridinium cation, 1,2,3-trimethyl-1,6-dihydropyridinium cation, 1,2,3,4-tetramethyl-1,4-dihydropyridinium cation, and 1,2,3,4-tetramethyl-1,6-dihydropyridinium cation; these cations further have at least one selected from vinyl (CH2=CH- group) and allyl (CH2=CH-CH2- group) groups, etc.

[0137] Among them, 1,3-dimethylimidazolium cation, 1,3-diethylimidazolium cation, 1-ethyl-3-methylimidazolium cation, 1-butyl-3-methylimidazolium cation, 1-hexyl-3-methylimidazolium cation, 1-octyl-3-methylimidazolium cation, 1-decyl-3-methylimidazolium cation, 1-dodecyl-3-methylimidazolium cation, 1-tetradecyl-3-methylimidazolium cation are preferred in terms of further exhibiting the effects of the present invention. Imidazolium cations such as methylimidazolium cations, cations in which these cations further have at least one selected from vinyl (CH2=CH- group) and allyl (CH2=CH-CH2- group), more preferably 1-ethyl-3-methylimidazolium cations, 1-hexyl-3-methylimidazolium cations, and cations in which these cations further have at least one selected from vinyl (CH2=CH- group) and allyl (CH2=CH-CH2- group).

[0138] Examples of the cationic structure represented by the general formula (3) include a pyrazolium cationic structure and a pyrazolinium cationic structure.

[0139] Specific examples of the cation represented by the general formula (3) include pyrazolium cations such as 1-methylpyrazolium cation, 3-methylpyrazolium cation, 1-ethyl-2-methylpyrazolinium cation, 1-ethyl-2,3,5-trimethylpyrazolium cation, 1-propyl-2,3,5-trimethylpyrazolium cation, and 1-butyl-2,3,5-trimethylpyrazolium cation; pyrazolium cations such as 1-ethyl-2,3,5-trimethylpyrazolium cation, 1-propyl-2,3,5-trimethylpyrazolium cation, and 1-butyl-2,3,5-trimethylpyrazolium cation; and cations further having at least one selected from a vinyl group (CH2=CH- group) and an allyl group (CH2=CH-CH2- group).

[0140] Examples of the cationic structure represented by the general formula (4) include a tetraalkylammonium cationic structure, a trialkylsulfonium cationic structure, a tetraalkylphosphonium cationic structure, and a structure in which a portion of the above alkyl groups is replaced by an alkenyl group, an alkoxy group, or an epoxy group.

[0141] Specific examples of the cation represented by the general formula (4) include tetramethylammonium cation, tetraethylammonium cation, tetrabutylammonium cation, tetrapentylammonium cation, tetrahexylammonium cation, tetraheptylammonium cation, triethylmethylammonium cation, tributylethylammonium cation, trimethylpropylammonium cation, trimethyldecylammonium cation, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium cation, glycidyltrimethylammonium cation, diallyldimethylammonium cation, N,N-dimethyl-N-ethyl-N-propylammonium cation, N,N-dimethyl-N-ethyl-N-butylammonium cation, N,N-dimethyl-N-ethyl-N-pentylammonium cation, N,N-dimethyl-N-ethyl-N-hexyl N,N-dimethyl-N-ethyl-N-heptylammonium cation, N,N-dimethyl-N-ethyl-N-nonylammonium cation, N,N-dimethyl-N,N-dipropylammonium cation, N,N-diethyl-N-propyl-N-butylammonium cation, N,N-dimethyl-N-propyl-N-pentylammonium cation, N,N-dimethyl-N-propyl-N-hexylammonium cation, N,N-dimethyl-N-propyl-N-heptylammonium cation, N,N-dimethyl-N-butyl-N-hexylammonium cation, N,N-diethyl-N-butyl-N-heptylammonium cation, N,N-dimethyl-N-pentyl-N-hexylammonium cation, N,N-dimethyl-N,N-dihexylammonium cation, trimethylheptyl ammonium cation, N,N-diethyl-N-methyl-N-propylammonium cation, N,N-diethyl-N-methyl-N-pentylammonium cation, N,N-diethyl-N-methyl-N-heptylammonium cation, N,N-diethyl-N-propyl-N-pentylammonium cation, triethylpropylammonium cation, triethylpentylammonium cation, triethylheptylammonium cation, N,N-dipropyl-N-methyl-N-ethylammonium cation, N,N-dipropyl-N-methyl-N-pentylammonium cation, N,N-dipropyl-N-butyl-N-hexylammonium cation, N,N-dipropyl-N,N-dihexylammonium cation, N,N-dibutyl-N-methyl-N-pentylammonium cation, N,N-dibutyl-N-methyl-N-hexyl ammonium cation, trioctylmethylammonium cation, N-methyl-N-ethyl-N-propyl-N-pentylammonium cation and other tetraalkylammonium cations; trimethylsulfonium cation, triethylsulfonium cation, tributylsulfonium cation, trihexylsulfonium cation, diethylmethylsulfonium cation, dibutylethylsulfonium cation, dimethyldecylsulfonium cation and other trialkylsulfonium cations; tetramethylphosphonium cation, tetraethylphosphonium cation, tetrabutylphosphonium cation, tetrahexylphosphonium cation, tetraoctylphosphonium cation, triethylmethylphosphonium cation, tributylethylphosphonium cation, trimethyldecylphosphonium cation and other tetraalkylphosphonium cations; these cations further have at least one cation selected from vinyl (CH2=CH- group) and allyl (CH2=CH-CH2- group) and the like.

[0142] As the ionic compound, preferably, it is an ionic compound containing at least one selected from the above-mentioned onium cations and the above-mentioned metal cations and the above-mentioned fluorinated organic anion, or an ionic group-containing organosilicon oligomer, more preferably, it is an ionic compound containing at least one selected from the above-mentioned onium cations and the above-mentioned metal cations and the above-mentioned fluorinated organic anion, and further preferably, it is an ionic compound containing the above-mentioned onium cation and the above-mentioned fluorinated organic anion.

[0143] In terms of being able to further demonstrate the effects of the present invention, the ionic compound is preferably 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(trifluoromethanesulfonyl)imide, 1-octyl-4-methylpyridinium bis(fluorosulfonyl)imide, 1-methyl-1-propyl Pyrrolidinium bis(trifluoromethanesulfonyl)imide, 1-methyl-1-propylpyrrolidinium 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, 1-allyl- 3-methyl-imidazolium trifluoromethanesulfonate, 1-allyl-3-methyl-imidazolium heptafluoropropanesulfonate, 1-allyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide, 1-allyl-3-methyl-imidazolium bis(fluorosulfonyl)imide, methyltrioctylammonium bis(trifluoromethanesulfonyl)imide, trimethylpropylammonium bis(trifluoromethanesulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(fluorosulfonyl)imide; more preferably 1-butyl-3-methylpyridinium bis(trifluoromethanesulfonyl)imide, 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide Imide, 1-allyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide, methyltrioctylammonium bis(trifluoromethanesulfonyl)imide, trimethylpropylammonium bis(trifluoromethanesulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide; particularly preferred are 1-butyl-3-methylpyridinium bis(trifluoromethanesulfonyl)imide, 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide, 1-allyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide, methyltrioctylammonium bis(trifluoromethanesulfonyl)imide, and trimethylpropylammonium bis(trifluoromethanesulfonyl)imide.

[0144] The ionic compound may be a commercially available compound or a compound synthesized by any appropriate method. For example, an ionic liquid may be synthesized by a halide method, a hydroxide method, an acid ester method, a complex method, a neutralization method, or the like.

[0145] 〔Surfactant〕

[0146] If a fluorine-based additive as a surfactant is contained as another component, the easy peelability and high-speed antistatic performance of the surface protection film according to the embodiment of the present invention can be further improved.

[0147] As the fluorine-based additive, any appropriate fluorine-based additive may be adopted within a range not impairing the effects of the present invention.

[0148] The fluorine-based additive may be used alone or in combination of two or more.

[0149] The content of the fluorine-based additive relative to the total amount of the urethane prepolymer and the second polyol is preferably 0.01% by weight or greater, more preferably 0.03 to 30 parts by weight, even more preferably 0.05 to 10 parts by weight, and particularly preferably 0.05 to 1 part by weight. If the content of the fluorine-based additive relative to the total amount of the urethane prepolymer and the second polyol is within this range, the easy-peelability and antistatic properties of the surface protection film according to an embodiment of the present invention can be further improved.

[0150] In order to further demonstrate the effects of the present invention, the total amount of the fluorine-based additive and the silicone-based additive described below is 0.01% by weight or more, more preferably 0.03 to 30 parts by weight, further preferably 0.05 to 10 parts by weight, and particularly preferably 0.05 to 1 part by weight, relative to the total amount of the urethane prepolymer and the second polyol.

[0151] Examples of the fluorine-based additive include at least one selected from fluorine-containing compounds, fluorine-based compounds containing a hydroxyl group, and fluorine-based compounds containing a crosslinkable functional group.

[0152] Examples of fluorinated compounds include compounds having a fluorinated aliphatic hydrocarbon backbone, fluorinated organic compounds copolymerized with fluorinated compounds, and fluorinated compounds containing organic compounds. Examples of fluorinated aliphatic hydrocarbon backbones include fluorinated C1-C10 alkanes such as fluoromethane, fluoroethane, fluoropropane, fluoroisopropylane, fluorobutane, fluoroisobutylane, fluorotert-butane, fluoropentane, and fluorohexane. The designation "C1-C10" indicates a carbon number of 1 to 10.

[0153] A preferred embodiment of the fluorine-containing compound is an oligomer having a fluorine-containing group and a hydrophilic group and / or a lipophilic group ("specific fluorine-based compound"). By adopting such a "specific fluorine-based compound", the light peelability and antistatic performance of the surface protective film according to the embodiment of the present invention can be improved. In particular, by combining such a "specific fluorine-based compound" with an ionic compound, the light peelability and antistatic performance of the surface protective film according to the embodiment of the present invention can be further improved. It is speculated that this is because the specific fluorine-based compound causes the ionic compound to be unevenly present on the surface side of the urethane adhesive layer (the side that is bonded to the adherend). As fluorine-containing groups, representative examples include: fluorine-containing alkyl groups (for example, CF3-, etc.) and / or fluorine-containing alkylene groups (for example, -CF2-CF2-, etc.). A hydrophilic group refers to a group having hydrophilicity. Hydrophilicity is translated into "hydrophilic" in English, which means "having affinity with water" and is a property generally understood by those skilled in the art. A lipophilic group refers to a group having lipophilicity. Lipophilicity is translated into "lipophilic" in English, which means "having affinity with oil" and is a property generally understood by those skilled in the art.

[0154] To further enhance the ease of peeling of the surface protective film according to embodiments of the present invention, the fluorine-containing compound preferably has a surface tension of 19.0 mN / m to 26.0 mN / m (the surface tension of toluene is 27.9 mN / m) when prepared as a 0.1% toluene solution. Thus, if the surface tension of the fluorine-containing compound when prepared as a 0.1% toluene solution is within this narrow, specific range of 19.0 mN / m to 26.0 mN / m, the ease of peeling of the surface protective film according to embodiments of the present invention can be further enhanced.

[0155] To further enhance the antistatic performance of the surface protection film according to embodiments of the present invention, the fluorine-containing compound preferably has a surface tension of 26.0 mN / m to 28.0 mN / m when prepared as a 0.1% toluene solution (the surface tension of toluene is 27.9 mN / m). Thus, if the surface tension of the fluorine-containing compound when prepared as a 0.1% toluene solution is within the narrow, specific range of 26.0 mN / m to 28.0 mN / m, the antistatic performance of the surface protection film according to embodiments of the present invention can be further enhanced.

[0156] As commercially available fluorine-containing compounds, for example, the following are mentioned.

[0157] DIC Corporation's DMAGAFACE series:

[0158] Typically, "MAGAFACEF-114", "MAGAFACEF-251", "MAGAFACEF-253", "MAGAFACEF-281", "MAGAFACEF-410", "MAGAFACEF-430", "MAGAFACEF-444", "MAGAFACEF-477", "MAGAFACEF-510", "MAGAFACEF-551-A", "MAGAFACEF-553", "MAGAFACEF-554", "MAGAFACEF-555-A", "MAGAFACEF-556", "MAGAFACEF-557", "MAGAFACEF-558", "MAGAFACEF-559", "MAGAFACEF-560", "MAGAFACEF-561", "MAGAFACEF-562", "MAGAFACEF-563", "MAGAFACEF-565", "MAGAFACEF-568", "MAGAFACEF-569", "MAGAFACEF-570", "MAGAFACEF-576", "MAGAFACER-01", "MAGAFACER-40", "MAGAFACER-40-LM", "MAGAFACER-41", "MAGAFACER-41-LM", "MAGAFACER-94", "MAGAFACERS-56", "MAGAFACERS-72-K", "MAGAFACERS-75-A", "MAGAFACERS-75-NS", "MAGAFACERS-78", "MAGAFACERS-90", etc.

[0159] DSURFLON series manufactured by AGC SEIMI CHEMICAL Co., Ltd.:

[0160] Typically, "S-242", "S-243", "S-386", etc.

[0161] DFC series manufactured by Sumitomo 3M Co., Ltd.:

[0162] Typically, "FC-4430", "FC-4432", etc.

[0163] DFTERGENT series manufactured by NEOS Co., Ltd.:

[0164] Representatively, “FTERGENT100”, “FTERGENT100C”, “FTERGENT110”, “FTERGENT150”, “FTERGENT150CH”, “FTERGENT250”, “FTERGENT400SW”, etc.

[0165] Kitamura Chemical Industry Co., Ltd. DPF series:

[0166] Representatively, "PF-136A", "PF-156A", "PF-151N", "PF-636", "PF-6320", "PF-656", "PF-6520", "PF-651", "PF-652", "PF-3320", etc.

[0167] As the hydroxyl group-containing fluorine-based compound, for example, conventionally known resins can be used, and examples thereof include the hydroxyl group-containing fluorine resins described in International Publication No. 94 / 06870, Japanese Patent Application Laid-Open No. 8-12921, Japanese Patent Application Laid-Open No. 10-72569, Japanese Patent Application Laid-Open No. 4-275379, International Publication No. 97 / 11130, and International Publication No. 96 / 26254. Other hydroxyl group-containing fluorine resins include, for example, fluoroolefin copolymers described in Japanese Patent Application Laid-Open No. 8-231919, Japanese Patent Application Laid-Open No. 10-265731, Japanese Patent Application Laid-Open No. 10-204374, and Japanese Patent Application Laid-Open No. 8-12922. In addition, examples include copolymers of compounds having a fluorinated alkyl group in the hydroxyl-containing compound, fluorinated organic compounds obtained by copolymerizing a hydroxyl-containing compound with a fluorinated compound, and fluorinated compounds containing a hydroxyl-containing organic compound. Examples of commercially available hydroxyl-containing fluorinated compounds include: "LUMIFLON" (manufactured by Asahi Glass Co., Ltd.), "CEFRALCOAT" (manufactured by Central Glass Co., Ltd.), "ZAFLON" (manufactured by Toagosei Co., Ltd.), and "ZEFFLE" (manufactured by Daikin Industries Co., Ltd.).

[0168] Examples of cross-linkable functional group-containing fluorine-containing compounds include carboxylic acid compounds having a fluorinated alkyl group such as perfluorooctanoic acid, copolymers of cross-linkable functional group-containing compounds having a fluorinated alkyl group, fluorinated organic compounds copolymerized with cross-linkable functional group-containing compounds and fluorinated compounds, and fluorinated compounds containing cross-linkable functional group-containing compounds. Examples of such cross-linkable functional group-containing fluorine-containing compounds commercially available include trade names such as "MEGAFAC F-570," "MEGAFAC RS-55," "MEGAFAC RS-56," "MEGAFAC RS-72-K," "MEGAFAC RS-75," "MEGAFAC RS-76-E," "MEGAFAC RS-76-NS," "MEGAFAC RS-78," and "MEGAFAC RS-90" (manufactured by DIC Corporation).

[0169] In order to further demonstrate the effects of the present invention, the total amount of the aforementioned fluorine-based additives is 0.01% by weight or more relative to the total amount of the urethane prepolymer and the second polyol, more preferably 0.03% by weight to 30 parts by weight, further preferably 0.05 parts by weight to 10 parts by weight, and particularly preferably 0.05 parts by weight to 1 part by weight.

[0170] 〔Antioxidant〕

[0171] The urethane adhesive composition may further contain an antioxidant as another component from the viewpoint of suppressing degradation of the urethane adhesive layer, etc. The antioxidant may be one kind or two or more kinds.

[0172] The antioxidant content in the urethane adhesive composition may be any appropriate content within a range that does not impair the effects of the present invention. The antioxidant content relative to the total amount of the urethane prepolymer and the second polyol is preferably 0.01% to 10% by weight, more preferably 0.05% to 5% by weight, further preferably 0.1% to 3% by weight, and particularly preferably 0.2% to 1% by weight.

[0173] Examples of the antioxidant include radical chain inhibitors and peroxide decomposers.

[0174] Examples of the radical chain inhibitor include phenolic antioxidants and amine antioxidants.

[0175] Examples of the peroxide decomposer include sulfur-based antioxidants and phosphorus-based antioxidants.

[0176] Examples of the phenolic antioxidant include monophenolic antioxidants, bisphenolic antioxidants, and polymeric phenolic antioxidants.

[0177] Examples of the monophenol antioxidant include 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-tert-butyl-4-ethylphenol, and n-octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

[0178] Examples of the bisphenol antioxidant include 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-thiobis(3-methyl-6-tert-butylphenol), 4,4'-butylenebis(3-methyl-6-tert-butylphenol), and 3,9-bis[1,1-dimethyl-2-[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]2,4,8,10-tetraoxaspiro[5,5]undecane.

[0179] Examples of the high molecular weight phenolic antioxidant include 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tetrakis-[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]methane, bis[3,3'-bis(4'-hydroxy-3'-tert-butylphenyl)butanoic acid]diol ester, 1,3,5-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl)-S-triazine-2,4,6-(1H,3H,5H)trione, and tocopherol.

[0180] Examples of the sulfur-based antioxidant include dilauryl 3,3'-thiodipropionate, dimyristyl 3,3'-thiodipropionate, and distearyl 3,3'-thiodipropionate.

[0181] Examples of the phosphorus-based antioxidant include triphenyl phosphite, diphenyl isodecyl phosphite, and phenyl diisodecyl phosphite.

[0182] 〔UV absorber〕

[0183] The urethane adhesive composition may further contain an ultraviolet absorber as another component from the viewpoint of suppressing degradation of the urethane adhesive layer, etc. The ultraviolet absorber may be one type or two or more types.

[0184] The content of the ultraviolet absorber in the urethane adhesive composition may be any appropriate content within a range that does not impair the effects of the present invention. The ultraviolet absorber content relative to the total amount of the urethane prepolymer and the second polyol is preferably 0.01% to 10% by weight, more preferably 0.05% to 5% by weight, further preferably 0.1% to 3% by weight, and particularly preferably 0.2% to 1% by weight.

[0185] Examples of the ultraviolet absorber include benzophenone ultraviolet absorbers, benzotriazole ultraviolet absorbers, salicylic acid ultraviolet absorbers, oxalic acid anilide ultraviolet absorbers, cyanoacrylate ultraviolet absorbers, and triazine ultraviolet absorbers.

[0186] Examples of the benzophenone-based ultraviolet absorber include 2,4-hydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2,2'-hydroxy-4-dimethoxybenzophenone, 2,2'-hydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, and bis(2-methoxy-4-hydroxy-5-benzoylphenyl)methane.

[0187] Examples of the benzotriazole-based ultraviolet absorbers include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-5'-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, and 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole. -di-tert-amylphenyl)benzotriazole, 2-(2'-hydroxy-4'-octyloxyphenyl)benzotriazole, 2-[2'-hydroxy-3'-(3'',4'',5'',6'',-tetrahydrophthalimidomethyl)-5'-methylphenyl]benzotriazole, 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol], [2-(2'-hydroxy-5'-methacryloyloxyphenyl)-2H-benzotriazole.

[0188] Examples of the salicylic acid-based ultraviolet absorber include phenyl salicylate, p-tert-butylphenyl salicylate, and p-octylphenyl salicylate.

[0189] Examples of the cyanoacrylate-based ultraviolet absorber include 2-ethylhexyl-2-cyano-3,3'-diphenylacrylate and ethyl-2-cyano-3,3'-diphenylacrylate.

[0190] 〔Light stabilizer〕

[0191] The urethane adhesive composition may further contain a light stabilizer as another component from the viewpoint of suppressing degradation of the urethane adhesive layer.

[0192] The light stabilizer content in the urethane adhesive composition may be any appropriate content within a range that does not impair the effects of the present invention. The light stabilizer content relative to the total amount of the urethane prepolymer and the second polyol is preferably 0.01% to 10% by weight, more preferably 0.05% to 5% by weight, further preferably 0.1% to 3% by weight, and particularly preferably 0.2% to 1% by weight.

[0193] Examples of the light stabilizer include hindered amine light stabilizers and ultraviolet light stabilizers.

[0194] Examples of the hindered amine light stabilizer include bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, and methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate.

[0195] Examples of the ultraviolet stabilizer include bis(octylphenyl)nickel sulfide, [2,2′-thiobis(4-tert-octylphenol)]-n-butylamine nickel, 3,5-di-tert-butyl-4-hydroxybenzyl monoethyl phosphate nickel complex, nickel dibutyldithiocarbamate, benzoate-type quenchers, and nickel dibutyldithiocarbamate.

[0196] [Fatty acid esters]

[0197] The urethane adhesive composition may further contain a fatty acid ester as another component in order to improve the wettability of the urethane adhesive layer, etc. The fatty acid ester may be one kind or two or more kinds.

[0198] The number average molecular weight Mn of fatty acid ester is preferably 200~400, more preferably 210~395, further preferably 230~380, particularly preferably 240~360, most preferably 250~350.By being adjusted in the above-mentioned scope by the number average molecular weight Mn of fatty acid ester, can more improve wetting speed.If the number average molecular weight Mn of fatty acid ester is too little, even then adding umber is more, also may not improve wetting speed.If the number average molecular weight Mn of fatty acid ester is too large, then the curing property deterioration of the tackiness agent during drying may not only be to wetting characteristics, also can produce adverse effect to other adhesive properties.

[0199] As the fatty acid ester, any appropriate fatty acid ester can be adopted within the scope of not damaging the effect of the present invention. As such fatty acid ester, for example: polyoxyethylene bisphenol A laurate, butyl stearate, 2-ethylhexyl palmitate, 2-ethylhexyl stearate, behenic acid monoglyceride, 2-ethylhexanoic acid cetyl ester, isopropyl myristate, isopropyl palmitate, cholesterol isostearate, lauryl methacrylate, coconut oil fatty acid methyl ester, methyl laurate, methyl oleate, methyl stearate, myristyl myristate, octyldodecyl myristate, pentaerythritol monooleate, pentaerythritol monostearate, pentaerythritol tetrapalmitate, stearyl stearate, isotridecyl stearate, 2-ethylhexanoic acid triglyceride, butyl laurate, octyl oleate.

[0200] 1-2. Base material layer

[0201] The thickness of the substrate layer may be any appropriate thickness depending on the intended use. The thickness of the substrate layer is preferably 5 μm to 300 μm, more preferably 10 μm to 250 μm, further preferably 15 μm to 200 μm, and particularly preferably 20 μm to 150 μm.

[0202] The substrate layer may be a single layer or a laminate of two or more layers. The substrate layer may be stretched.

[0203] The substrate layer can be made of any suitable material depending on the intended use. Examples include plastic, paper, metal film, and nonwoven fabric. Plastic is preferred. The substrate layer may be composed of a single material or two or more materials. For example, it may be composed of two or more plastics.

[0204] 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. Examples of polyolefin resins include homopolymers of olefin monomers and copolymers of olefin monomers. Specific examples of polyolefin resins include homopolypropylene; propylene copolymers such as block, random, and graft copolymers containing ethylene as a copolymer component; reactor TPO; ethylene polymers such as low-density, high-density, linear low-density, and ultra-low-density ethylene polymers; and ethylene copolymers such as ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, ethylene-methyl acrylate copolymers, ethylene-ethyl acrylate copolymers, ethylene-butyl acrylate copolymers, ethylene-methacrylic acid copolymers, and ethylene-methyl methacrylate copolymers.

[0205] The substrate layer may contain any appropriate additives as needed. Examples of additives that may be contained in the substrate layer include antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, fillers, and pigments. The type, number, and amount of additives that may be contained in the substrate layer may be appropriately set according to the intended purpose. In particular, when the substrate layer is made of plastic, it is preferred to contain a plurality of the above-mentioned additives to prevent degradation. From the perspective of improving weather resistance, particularly preferred additives include antioxidants, ultraviolet absorbers, light stabilizers, and fillers.

[0206] Any appropriate antioxidant can be used as the antioxidant. Examples of such antioxidants include phenolic antioxidants, phosphorus-based processing heat stabilizers, lactone-based processing heat stabilizers, sulfur-based heat stabilizers, and phenol-phosphorus-based antioxidants. The antioxidant content is preferably 1% by weight or less, more preferably 0.5% by weight or less, and even more preferably 0.01% to 0.2% by weight, relative to the base resin of the base layer (if the base layer is a blend, the blend is the base resin).

[0207] Any appropriate UV absorber can be used. Examples of such UV absorbers include benzotriazole-based UV absorbers, triazine-based UV absorbers, and benzophenone-based UV absorbers. The UV absorber content is preferably 2% by weight or less, more preferably 1% by weight or less, and even more preferably 0.01% to 0.5% by weight, relative to the base resin forming the base layer (if the base layer is a blend, the blend is the base resin).

[0208] Any appropriate light stabilizer can be used. Examples of such light stabilizers include hindered amine light stabilizers and benzoate light stabilizers. The light stabilizer content is preferably 2% by weight or less, more preferably 1% by weight or less, and even more preferably 0.01% to 0.5% by weight, relative to the base resin forming the base layer (if the base layer is a blend, the blend is the base resin).

[0209] Any suitable filler can be used as the filler. Examples of such fillers include inorganic fillers. Specific examples of inorganic fillers include carbon black, titanium oxide, and zinc oxide. The filler content is preferably 20% by weight or less, more preferably 10% by weight or less, and even more preferably 0.01% to 10% by weight, relative to the base resin forming the base layer (if the base layer is a blend, the blend is the base resin).

[0210] Furthermore, as additives for imparting antistatic properties, preferred examples include inorganic, low-molecular-weight, and high-molecular-weight antistatic agents such as surfactants, inorganic salts, polyols, metal compounds, and carbon. In particular, high-molecular-weight antistatic agents and carbon are preferred from the viewpoints of preventing contamination and maintaining adhesiveness.

[0211] 2. Surface Protection Film Manufacturing Method

[0212] The surface protection film of the present invention can be manufactured by any appropriate method. As such a manufacturing method, for example, it can be carried out according to any appropriate manufacturing method, for example:

[0213] (1) A method of applying a solution or hot melt of a material for forming an adhesive layer onto a substrate layer;

[0214] (2) A method for transferring the adhesive layer applied and formed into a membrane-like shape onto a substrate layer;

[0215] (3) A method of forming and coating the adhesive layer by extruding the adhesive layer forming material onto the base material layer;

[0216] (4) A method of extruding the substrate layer and the adhesive layer into a double layer or multiple layers;

[0217] (5) A method of laminating a single adhesive layer on a substrate layer, or a method of laminating a double adhesive layer together with a laminating layer;

[0218] (6) A method of forming a material by laminating a double or multi-layer adhesive layer and a base layer such as a film or a laminate layer.

[0219] As the coating method, for example, a roll coater method, a comma coater method, a slot die coater method, a reverse coater method, a screen printing method, a gravure coater method, etc. can be used.

[0220] 3. Applications of Surface Protection Film

[0221] The surface protection film according to the embodiment of the present invention can be used for any appropriate purpose. Preferably, the surface protection film of the present invention has very little contamination to the adherend and preferably has excellent wettability and reworkability, and is therefore preferably used for surface protection of optical components and electronic components, for example.

[0222] Components to which the surface protection film according to the embodiment of the present invention is attached, such as optical components and electronic components, can have the attached surface protection film repeatedly attached and peeled off by manual operation.

[0223] That is, the optical component according to the embodiment of the present invention has the surface protection film of the present invention adhered thereto. In addition, the electronic component according to the embodiment of the present invention has the surface protection film of the present invention adhered thereto.

[0224] The present invention provides a surface protection film, comprising a carbamate adhesive layer, wherein the carbamate adhesive layer is composed of a carbamate adhesive, which is formed from a carbamate adhesive composition, and the carbamate adhesive composition at least comprises a carbamate prepolymer and an antistatic functional agent; the antistatic functional agent comprises an ionic compound and a surfactant, and the addition ratio of the ionic compound to the surfactant satisfies: 2≤ionic compound / surfactant≤50; the carbamate prepolymer is obtained by reacting a first polyol and an organic polyisocyanate compound, the first polyol comprises a polyether polyol and a polyester polyol, and the addition ratio of the polyether polyol to the polyester polyol satisfies: 5≤polyether polyol / polyester polyol≤50.

[0225] The ionic compounds added in the present application achieve charge dissipation by reducing surface resistance, while the surfactants can inhibit the aggregation of ionic compounds and improve dispersion uniformity. The synergistic effect of the two can stabilize the charge release during the stripping process and reduce the electrostatic voltage mutation caused by charge accumulation. In the prior art, pure polyether polyols are generally used to prepare urethane prepolymers. However, compared with polyester polyols (-COO-) adhesives, polyether polyol (-COC-) adhesives have lower polarity, weaker intermolecular forces and are usually non-crystalline materials. They have poor compatibility with low-polarity or non-polar ionic compounds, resulting in ionic compounds easily migrating in the material. The present invention reduces the precipitation of ionic compounds while ensuring the properties of the adhesive itself through the rational compounding of polyether polyols and polyester polyols.

[0226] Furthermore, the addition ratio of the ionic compound to the surfactant satisfies: 2≤ionic compound / surfactant≤30; the addition ratio of the polyether polyol to the polyester polyol satisfies: 5≤polyether polyol / polyester polyol≤25.

[0227] It is understood that the rational combination of ionic compounds and surfactants can ensure a balance between charge dissipation efficiency and dispersibility. The rational combination of polyether polyols and polyester polyols optimizes the balance between stripping charge voltage and ionic stability.

[0228] It is understood that the limits set forth herein for the ratio of the ionic compound to the surfactant, and for the ratio of the polyether polyol to the polyester polyol, can also be understood as the range of the compounding ratio of the antistatic functional agent and the first polyol. In practice, the prior art generally does not consider the addition ratio of the polyether polyol to the polyester polyol. The prior art typically utilizes a pure polyether system or simply mixes the polyether polyol and the polyester polyol in a 1:1 ratio, without considering the technical benefit of the addition of the polyester polyol in reducing the precipitation of ionic compounds from the adhesive.

[0229] Furthermore, the addition ratio of polyether polyols and polyester polyols and the addition ratio of ionic compounds and surfactants in the present application actually have a synergistic effect within a certain specific range, and the content of polyester polyols is not a simple linear relationship for the precipitation of anti-ionic compounds. When polyester polyols are too little, the network of the polymer is not dense enough, so the ionic compound is easy to precipitate, but after the polyester polyol reaches a certain limit, even if it exceeds this limit, the precipitation concentration of the ionic compound will no longer decrease, proving that the cross-linking density of the polymer network under this limit is sufficient to control the precipitation of ionic compounds. However, when there are too many polyester polyols, the network of the polymer is too dense, which will affect the characteristic of the ionic compound itself to reduce the stripping charged voltage. Therefore, the present application reasonably sets the addition ratio of polyether polyols and polyester polyols and the addition ratio of ionic compounds and surfactants, and finally achieves a mutual balance between the low stripping charged voltage and the low ion precipitation concentration of the surface protective film.

[0230] Furthermore, the mass ratio of the ionic compound to the polyester polyol is 1:(1-10). This application rationally sets the mass ratio of the ionic compound to the polyester polyol, effectively balancing the ability to reduce the stripping charge voltage and resist ion precipitation. When the polyester polyol is excessive relative to the mass of the ionic compound, the polymer network is too dense, making it difficult for ions to migrate and neutralize the static charge at the stripping interface, which in turn leads to an increase in the stripping charge voltage. At the same time, an excessively high polyester content can also reduce the flexibility of the adhesive, exacerbating stress concentration during the stripping process and further increasing the stripping charge voltage. When the polyester polyol is too low, the excess ionic compound exceeds the substrate's carrying capacity and easily migrates from the polymer network to the surface, resulting in a decrease in resistance to precipitation during long-term use, further contaminating the contact interface and causing corrosion to the adhered object.

[0231] Furthermore, the crosslinking density of the urethane prepolymer is 76% to 80%. The present application reasonably sets the ratio of polyether polyol and polyester polyol to control the crosslinking density of the urethane prepolymer. Pure polyether polyol has an ether bond (-O-) as the main chain structure, and the crosslinking environment has an ether bond (-O-) as the main chain structure. The free volume that can move is about 7% to 10%, and the crosslinking density depends only on the urethane bond crosslinking. There is less physical crosslinking and the crosslinking density is low (about 74%), which is conducive to the diffusion of small molecules. In the polyether / polyester mixed system, the polyester chain has an ester group (-COO-) as the main chain structure. As the proportion of the polyester system added increases, the rigid chain gradually increases, causing the free volume that can move to drop to 3% to 6%. Compared with the pure polyether system, the ester group in the polyether / polyester mixed system can form a hydrogen bond network with the urethane, thereby enhancing physical crosslinking, effectively increasing the crosslinking density, and reducing the precipitation of ionic compounds.

[0232] Furthermore, the molecular weight of the polyether polyol is 50,000 to 100,000, and the PDI is 5-10. Furthermore, the molecular weight of the polyester polyol is 30,000 to 80,000, and the PDI is 5-10. Polymer dispersity index (PDI) is a polymer dispersity index used to describe the polymer molecular weight distribution. The present application rationally controls the molecular weight and PDI of polyether polyols and polyester polyols, thereby adjusting the length and distribution of polyether chains and polyester chains, controlling the overall content and distribution uniformity of ether bonds and ester groups, thereby optimizing the cross-linking structure, free volume and ion migration path of the material, and ultimately achieving better antistatic performance and anti-precipitation ability.

[0233] It is understandable that pure polyether polyols have ether bonds (-O-) as their main chain structure, with a dipole moment of 1.3D and low polarity. The difference in polarity between the adhesive's interior and surface is small, making it easy to form a uniform but low-polarity crosslinking environment. Polyether / polyester blends contain ester groups (-COO-) as their main chain structure, with a dipole moment of 1.7D and higher polarity. Due to their polarity, ester groups tend to concentrate on the adhesive surface, making the adhesive surface more polar than the interior, thus forming a polarity gradient. This creates a denser, more stable, high-polarity region on the adhesive surface, which helps effectively reduce the precipitation of ionic compounds.

[0234] Furthermore, the equivalent ratio of the NCO groups of the organic polyisocyanate compound to the OH groups of the first polyol (NCO groups / OH groups) is 1.0 to 2.0. Ester groups and ether bonds form a polarity gradient. This application rationally sets the ratio of NCO groups to OH groups, ensuring that the surface-enriched ester groups have sufficient NCO groups to participate in crosslinking, forming a dense interfacial layer after curing, thereby effectively reducing the precipitation of ionic compounds.

[0235] Furthermore, the surface energy of the urethane prepolymer is 38mN / m to 43mN / m. Pure polyether polyols, with ether bonds (-O-) as the main chain structure, have a surface energy of approximately 30mN / m. However, the present invention incorporates polyester polyols into the system. The addition of polar ester groups increases the surface energy of the prepolymer to 38mN / m to 43mN / m, enhancing intermolecular forces and effectively increasing crosslinking density, thereby reducing the precipitation of ionic compounds.

[0236] Furthermore, the surfactant is a fluorine-based additive, specifically selected from at least one of a fluorine-containing compound, a fluorine-containing compound containing a hydroxyl group, and a fluorine-containing compound containing a crosslinkable functional group. When the surfactant is a fluorine-containing compound, the low surface energy of the fluorine-containing compound can effectively reduce surfactant migration and extend the antistatic life. More preferably, when the surfactant is a fluorine-containing compound containing a hydroxyl group or a fluorine-containing compound containing a crosslinkable functional group, the groups of the surfactant can react and crosslink with the polyester, thereby increasing the crosslink density and further limiting ion migration.

[0237] Furthermore, the ionic compound is a composition of at least one of an onium cation and a metal cation and a fluorine organic anion. When the ionic compound is a metal cation, the lone pair of electrons of the ester group can accept a proton and can combine with the metal cation to form a weak coordination effect. More preferably, when the ionic compound is an onium cation, the carbonyl oxygen (C=O) in the ester group (-COO-) of the polyester polyol has a strong electronegativity, which can generate electrostatic attraction with the onium cation and combine through a dipole-charge effect. The ether bond (-O-) of the polyether polyol is weakly polar (the dipole moment is about 1.3D), and the proportion of non-polar methylene (-CH2-) in its molecular chain segment is relatively high, forming a hydrophobic micro-region, which reacts with the perfluoroalkyl chain of the fluoride anion (such as CF3(CF2)3- ) achieves efficient bonding to non-polar regions through hydrophobic interactions (van der Waals forces). The low surface tension of fluoride anions reduces the interfacial energy of polyether polyols and promotes the enrichment of fluoride anions in hydrophobic microregions.

[0238] Furthermore, the content of the antistatic agent is 0.1% or more based on 100% by mass of the urethane adhesive composition.

[0239] Furthermore, the urethane adhesive composition further includes a second polyol and a polyfunctional isocyanate compound.

[0240] Furthermore, after the surface protection film was attached to the glass, when the surface protection film was peeled off at a peeling speed of 15 m / min, the peeling charged voltage was less than 100 V.

[0241] Furthermore, after the surface protection film was attached to the copper foil, the copper foil was tested at 20V for 15 minutes, and no corrosion or yellowing was observed. The surface protection film disclosed in this application has the advantage of low ion precipitation, which can effectively prevent the adhered object from being corroded by the ion compounds precipitated. The relevant principles are described in detail below:

[0242] In polyurethane systems containing ionic compounds, metal corrosion mainly involves electrochemical oxidation and anion complexation, with Cu being used as an example here.

[0243] (1) Basic steps of electrochemical corrosion:

[0244] Anodic reaction (copper dissolution): Cu→Cu 2+ +2e − ;

[0245] Cathode reaction (oxygen reduction or hydrogen evolution): O2+2H2O+4e − →4OH − (Neutral / alkaline environment)

[0246] or 2 hours + +2e − →H2 (acidic environment);

[0247] The above are the reasons why copper corrodes under normal circumstances.

[0248] (2) Catalytic effect of anions of ionic compounds:

[0249] CF3SO3 in ionic compounds - Can be used with Cu 2+ The formation of soluble complexes accelerates the dissolution of the anode. The specific reaction is as follows:

[0250] Cu 2+ +2CF3SO3 -→Cu(CF3SO3)2(soluble), this reaction will reduce the local Cu 2+ concentration, promoting the continuation of the anode reaction and accelerating the anode dissolution.

[0251] (3) Oxide layer destruction and prevention of repassivation:

[0252] The initial oxide layer on the copper surface is Cu2O or CuO, and the specific reaction is as follows: 4Cu+O2→2Cu2O (cuprous oxide);

[0253] The anions of ionic compounds will weaken the oxide layer structure through adsorption and hinder repassivation. The specific reaction is as follows:

[0254] Cu2O+4CF3SO3 - +H2O→2Cu(CF3SO3)2+2OH − .

[0255] In summary, it can be seen that when no measures are taken to prevent ionic compounds from precipitating from the surface protective film, especially when the adhered object is metal, the surface protective film cannot play a protective role and will instead cause the metal to corrode.

[0256] The following will explain in detail the principle of polyether polyol and polyester polyol mixed system inhibiting the corrosion of ionic compounds to metals:

[0257] (1) Polar binding effect of polyester system:

[0258] The polyester system can effectively inhibit the migration of ionic compounds. The ester group (-COO-) of the polyester chain and the sulfonyl group (-SO2-) of the ionic compound interact through dipole-dipole interaction, reducing the diffusion coefficient (D) of the ionic compound and reducing surface enrichment.

[0259] (2) Competition for complex formation:

[0260] Ester groups can react with Cu 2+ Forming a stable complex (such as Cu-OOCR), reducing the formation of Cu(CF3SO3)2, and inhibiting the dissolution of the anode. The specific reaction is as follows: Cu 2+ +2RCOO − →Cu(OOCR)2.

[0261] (3) Water and oxygen barrier of cross-linked network:

[0262] The low crosslink density of pure polyether systems allows water and oxygen to diffuse freely, providing ample reactants for electrochemical corrosion. The high crosslink density and hydrogen bond network formed by the polyether polyol and polyester polyol systems of this application can reduce water molecule permeability, reducing the water and oxygen supply required for the cathode reaction and suppressing the overall corrosion rate.

[0263] In summary, the pure polyether system provides a higher free diffusion capacity of water and oxygen than the polyester system, providing sufficient medium for the electrochemical reaction, and the ester group can 2+ The formation of stable complexes, high cross-linking and hydrogen bonds can effectively block and reduce electrochemical reactants. Therefore, the electrochemical properties will be better when polyester is added to a pure polyether system with ionic compounds.

[0264] The following will explain in detail the differences in curing between pure polyether systems and polyether / polyester combination systems:

[0265] The curing reaction of both polyurethane systems is based on the addition polymerization of polyols (polyethers or polyesters) and isocyanates (TDI). However, the ester group (-COO-) of the polyester chain introduces an additional polar group, which significantly affects the crosslinking network, as shown below:

[0266] (1) Curing reaction of pure polyether polyurethane:

[0267] Polyether triol (PPG) reacts with TDI to form urethane bonds:

[0268] PPG-(OH)3+3TDI→PPG-(OC(=O)-NH-TDI)3+3H2O (main reaction);

[0269] Features: Only relies on chemical crosslinking of urethane bonds, with less physical crosslinking (such as hydrogen bonds) and low crosslinking density.

[0270] (2) Curing reaction of polyether / polyester mixed polyurethane:

[0271] When polyester polyol (PBA) reacts with TDI, the ester group participates in hydrogen bond formation:

[0272] PBA-(OH) n +nTDI→PBA-(OC(=O)-NH-TDI) n +nH2O (main reaction);

[0273] Characteristics: The ester group (-COO-) forms a hydrogen bond with the NH in the carbamate: -COO−···HN-(carbamate). It can be seen that after the addition of polyester, in addition to chemical crosslinking, physical crosslinking (such as hydrogen bonding) also exists in the system, which effectively increases the crosslinking density.

[0274] It is understandable that the polyurethane backbone of a pure polyether system contains ether groups in addition to carbamate groups. The presence of numerous ether groups allows hydrogen bonding to form within and between polyurethane molecules. The thermodynamic incompatibility between the soft and hard segments induces the formation of hard and soft segment microdomains, resulting in a microscopic phase-separated structure, but the degree of microphase separation is low. However, the present application also incorporates a polyester polyol, which enhances the microphase separation between the soft segment (polyether / polyester) and the hard segment (carbamate). The hard segments form dense microdomains that serve as physical crosslinking points through hydrogen bonding and van der Waals forces, effectively enhancing the physical crosslinking of the polymer.

[0275] In another aspect, the present invention also provides an optical component having the aforementioned surface protection film attached to its surface. The surface protection film can be used, but is not limited to, as an encapsulation layer for organic light-emitting diodes (OLEDs), a protective layer or optical film for displays, optical films with a concave-convex surface structure (such as diffusers and brightness enhancement films), components in optical laminates (such as polarizers and retardation films), and protective films for thinned optical elements.

[0276] In another aspect, the present invention further provides an electronic component having the surface protection film attached thereto. The electronic component may include, but is not limited to, an overcurrent protection element, a circuit board assembly, an organic light-emitting electronic device, an electronic device module, a consumer electronic component, and a semiconductor device.

[0277] The present invention is described in detail below by way of examples, but the present invention is not limited by these examples. Surface protective films in various examples and comparative examples were prepared according to the proportions listed in Table 1.

[0278] Table 1

[0279]

[0280] In addition, when describing "parts", it means "parts by weight" unless otherwise specified, and when describing "%", it means "weight%" unless otherwise specified.

[0281] [Production Example]: Production of polyurethane prepolymer solution

[0282] A polymerization experimental apparatus equipped with a 1L round-bottom separable flask, a separable lid, a separatory funnel, a thermometer, a nitrogen inlet tube, a Liebig cooler, a vacuum seal, a stirring rod, and a stirring blade was charged with 80 parts by mass of polytetramethylene glycol, 20 parts by mass of polypropylene glycol, and 10 parts by mass of adipic acid-methylpentanediol. While stirring, 0.01 parts by mass of dibutyltin(IV) dilaurate was added as a catalyst, and nitrogen substitution was carried out at room temperature for 1 hour. Then, under nitrogen inflow, 5 parts by mass of hexamethylene diisocyanate was added while stirring. The solution temperature in the experimental apparatus was controlled at 90±2°C in a water bath and maintained at this temperature for 4 hours to obtain a polyurethane prepolymer solution. It should be noted that during the polymerization, ethyl acetate was added dropwise as needed to control the temperature during polymerization and prevent viscosity increase that would reduce stirrability. The solids concentration of the polyurethane prepolymer solution was 50% by weight.

[0283] Among them, the molecular weight of polybutylene glycol and polypropylene glycol is 80,000, and the PDI is 7; the molecular weight of adipic acid-methylpentanediol is 50,000, and the PDI is 7; the equivalent ratio of the NCO group of hexamethylene diisocyanate to the OH group of polybutylene glycol and polypropylene glycol is 1.5 in terms of NCO group / OH group.

[0284] [Example 1]:

[0285] The polyurethane prepolymer of Example 1 was prepared by referring to the preparation method of the preparation example.

[0286] 50 parts by weight of a polyurethane prepolymer, 50 parts by weight of a polyol having three hydroxyl groups as a polyol, 10 parts by weight of an isocyanate compound as a crosslinking agent, 1.5 parts by weight of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide as an ionic compound, 0.3 parts by weight of a fluorinated oligomer MEGAFACE DF-477 (manufactured by DIC Corporation), and 0.03 parts by weight of Nasem ferric iron as a catalyst were diluted with ethyl acetate to produce a urethane adhesive solution to a total solids content of 50% by weight. This urethane adhesive solution was then applied to a polyester resin substrate (trade name "T100-75S," 75 μm thick, manufactured by Mitsubishi Chemical Corporation) to a dried thickness of 75 μm. The solution was then cured and dried at a drying temperature of 130°C for 3 minutes to produce an adhesive layer comprising the adhesive composition. Next, a 25 μm thick release sheet made of a polyester resin (trade name "MRF25," 25 μm thick, manufactured by Mitsubishi Chemical Corporation) with one side treated with silicone was laminated onto the resulting adhesive layer to produce a surface protective film. The film was aged at room temperature for 5 days and then evaluated.

[0287] [Example 2]:

[0288] The polyurethane prepolymer of Example 2 was prepared by referring to the preparation method of Production Example.

[0289] The surface protection film of Example 2 was prepared according to the same method as in Example 1, except that 1.5 parts by weight of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide and 0.75 parts by weight of fluorinated oligomer MEGAFACED F-477 (manufactured by DIC Corporation) were used as the ionic compound.

[0290] [Example 3]:

[0291] The polyurethane prepolymer of Example 3 was prepared by referring to the preparation method of Production Example.

[0292] The surface protection film of Example 3 was prepared according to the same method as in Example 1, except that 1.5 parts by weight of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide and 0.1 parts by weight of fluorinated oligomer MEGAFACED F-477 (manufactured by DIC Corporation) were used as the ionic compound.

[0293] [Example 4]:

[0294] The polyurethane prepolymer of Example 4 was prepared by referring to the preparation method of the preparation example.

[0295] The surface protection film of Example 4 was prepared according to the same method as in Example 1, except that 1.5 parts by weight of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide and 0.05 parts by weight of fluorinated oligomer MEGAFACED F-477 (manufactured by DIC Corporation) were used as the ionic compound.

[0296] [Example 5]:

[0297] The polyurethane prepolymer of Example 5 was prepared by referring to the preparation method of Production Example.

[0298] The surface protection film of Example 5 was prepared according to the same method as in Example 1, except that 3 parts by weight of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide and 0.06 parts by weight of fluorinated oligomer MEGAFACED F-477 (manufactured by DIC Corporation) were used as the ionic compound.

[0299] [Example 6]:

[0300] The polyurethane prepolymer of Example 6 was prepared by referring to the preparation method of Preparation Example, except that 80 parts by mass of polybutylene glycol, 20 parts by mass of polypropylene glycol, and 20 parts by mass of adipic acid-methylpentanediol were used.

[0301] The preparation method of the surface protection film of Example 6 refers to Example 1.

[0302] [Example 7]:

[0303] The polyurethane prepolymer of Example 7 was prepared by referring to the preparation method of Preparation Example, except that 80 parts by mass of polybutylene glycol, 20 parts by mass of polypropylene glycol, and 6.7 parts by mass of adipic acid-methylpentanediol were used.

[0304] The preparation method of the surface protection film of Example 7 refers to Example 1.

[0305] [Example 8]:

[0306] The polyurethane prepolymer of Example 8 was prepared by referring to the preparation method of Preparation Example, except that 80 parts by mass of polybutylene glycol, 20 parts by mass of polypropylene glycol, and 4 parts by mass of adipic acid-methylpentanediol were used.

[0307] The preparation method of the surface protection film of Example 8 refers to Example 1.

[0308] [Example 9]:

[0309] The polyurethane prepolymer of Example 9 was prepared by referring to the preparation method of Preparation Example, except that 80 parts by mass of polybutylene glycol, 20 parts by mass of polypropylene glycol, and 2 parts by mass of adipic acid-methylpentanediol were used.

[0310] The preparation method of the surface protection film of Example 9 refers to Example 1.

[0311] [Example 10]:

[0312] The polyurethane prepolymer of Example 10 was prepared by referring to the preparation method of Preparation Example, except that the molecular weight of polybutylene glycol and polypropylene glycol was 50,000 and the PDI was 10.

[0313] The preparation method of the surface protection film of Example 10 refers to Example 1.

[0314] [Example 11]:

[0315] The polyurethane prepolymer of Example 11 was prepared by referring to the preparation method of Production Example, except that the molecular weight of the polyester polyol was 30,000 and the PDI was 10.

[0316] The preparation method of the surface protection film of Example 11 refers to Example 1.

[0317] [Comparative Example 1]:

[0318] The polyurethane prepolymer of Comparative Example 1 was prepared by referring to the preparation method of Preparation Example.

[0319] The surface protection film of Comparative Example 1 was prepared as in Example 1, except that 0.3 parts by weight of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide and 0.3 parts by weight of fluorine-based oligomer MEGAFACED F-477 (manufactured by DIC Corporation) were used as the ionic compound.

[0320] [Comparative Example 2]:

[0321] The polyurethane prepolymer of Comparative Example 2 was prepared by referring to the preparation method of Preparation Example.

[0322] The surface protection film of Comparative Example 2 was prepared as in Example 1, except that 1.5 parts by weight of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide and 0.015 parts by weight of fluorine-based oligomer MEGAFACED F-477 (manufactured by DIC Corporation) were used as the ionic compound.

[0323] [Comparative Example 3]:

[0324] The polyurethane prepolymer of Comparative Example 3 was prepared by referring to the preparation method of Preparation Example, except that 40 parts by mass of polybutylene glycol, 10 parts by mass of polypropylene glycol, and 50 parts by mass of adipic acid-methylpentanediol were used.

[0325] The preparation method of the surface protection film of Comparative Example 3 refers to Example 1.

[0326] [Comparative Example 4]:

[0327] The polyurethane prepolymer of Comparative Example 4 was prepared by referring to the preparation method of Preparation Example, except that 80 parts by mass of polybutylene glycol, 20 parts by mass of polypropylene glycol and 1 part by mass of adipic acid-methylpentanediol were used.

[0328] The preparation method of the surface protection film of Comparative Example 4 refers to Example 1.

[0329] [Comparative Example 5]:

[0330] The polyurethane prepolymer of Comparative Example 5 was prepared by referring to the preparation method of Preparation Example, except that 80 parts by mass of polybutylene glycol, 20 parts by mass of polypropylene glycol and 0 parts by mass of adipic acid-methylpentanediol were used.

[0331] The preparation method of the surface protection film of Comparative Example 5 refers to Example 1.

[0332] Test Case

[0333] In order to verify the performance of the product of the present invention, the surface protection films prepared in the examples and comparative examples were respectively subjected to relevant performance tests. The specific methods are as follows. The specific test results are shown in Table 2:

[0334] <Test methods and evaluation>

[0335] The surface protective film with the adhesive layer exposed was bonded to the surface of glass via the adhesive layer while a 2 kg roller was reciprocated once. After leaving it for 30 minutes, the sample was used as a measurement sample for the peeling charge voltage.

[0336] <Peeling Charge Voltage>

[0337] The obtained measurement sample was peeled off at a high peeling speed (15 m / min) along a 180° direction using a tensile testing machine. The voltage generated by the glass being charged (charged voltage) was measured using high-precision electrostatic sensors SK-035 and SK-200 (manufactured by KEYENCE Corporation). The maximum value of the measured value was taken as the peeling charged voltage.

[0338] <Color change test>

[0339] A copper sheet with a thickness of 36um (length and width of 50mm*50mm); C copper foil with a thickness of 36um (length and width of 120mm*120mm); B surface protective film laminate (thickness, length and width of 75um*100mm*100mm); B is placed between A / C, A / C copper foil is connected to positive and negative poles, the voltage is output to 20V or 30V, and after 15 minutes, check whether the copper foil changes color.

[0340] <Crosslinking density>

[0341] Within 10 minutes after the protective film is dried, the release liner is torn off from the protective film and about 0.1 g is scraped off the adhesive layer to make sample 1. After wrapping the above sample 1 with a PTFE filter membrane with a precision of 0.2 μm in diameter, it is tied with a kite string to make it sample 2. The weight of the sample 2 before the following test is measured and referred to as weight A. It should be noted that the above weight A is the total weight of the sample 1 (adhesive layer), the PTFE membrane, and the kite string. In addition, the total weight of the above PTFE membrane and the kite string is referred to as weight B. Next, the above sample 2 is placed in a 50 ml container filled with ethyl acetate and allowed to stand at 23°C for 1 week. Then, the sample 2 is taken out of the container and dried in a dryer at 130°C for 2 hours. After removing the ethyl acetate, the weight of the sample 2 is measured. The weight of the sample 2 after the above test is measured and referred to as weight C. The crosslinking density is calculated according to the following formula.

[0342] Crosslink density (%) = [(CB) / (AB)]*100%.

[0343] <Surface Energy of Urethane Prepolymer>

[0344] The surface energy was calculated by measuring the contact angle of liquid (diiodomethane) on the prepolymer surface and combining the Young-Laplace equation and the Owens-Wendt formula.

[0345] Table 2

[0346]

[0347] From the above results, it can be seen that the present invention successfully solves the problem of ionic compounds precipitating in polyurethane adhesives by using a combination of polyether polyol and polyester polyol in the first polyol for preparing the urethane prepolymer, and by using a specific addition ratio of polyether polyol and polyester polyol. It also cooperates with the specific addition ratio of ionic compounds and surfactants to finally achieve a balance between low peeling charge voltage and low ion precipitation concentration of the surface protective film.

[0348] Further, if Figures 2 to 4 As shown, Figure 2 This is the XPS spectrum of the surface protection film obtained in Example 1. Figure 3 This is the XPS spectrum of the surface protection film obtained in Example 9. Figure 4 This is the XPS spectrum of the surface protective film obtained in Comparative Example 4. The present application further verifies through the XPS spectrum that the addition of a specific proportion of polyester polyol in the present application increases the surface polarity, increases the polarity gradient, thereby increasing the cross-linking density, restricting the migration ability of small molecules, and significantly reducing the precipitation of fluorine.

[0349] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A surface protection film, characterized in that: The surface protection film includes a urethane adhesive layer, wherein the urethane adhesive layer is composed of a urethane adhesive, and the urethane adhesive is formed from a urethane adhesive composition, and the urethane adhesive composition includes at least a urethane prepolymer and an antistatic functional agent; The antistatic functional agent is composed of an ionic compound and a surfactant, and the mass addition ratio of the ionic compound to the surfactant satisfies: 2≤ionic compound / surfactant≤50; The urethane prepolymer is obtained by reacting a first polyol and an organic polyisocyanate compound, wherein the first polyol comprises a polyether polyol and a polyester polyol, and the mass addition ratio of the polyether polyol to the polyester polyol satisfies: 5≤polyether polyol / polyester polyol≤50; The mass ratio of the ionic compound to the polyester polyol is 1:(1-10); The ionic compound is a composition of at least one of an onium cation and a metal cation and a fluorine organic anion; The surfactant is a fluorine-based additive.

2. The surface protection film according to claim 1, characterized in that The mass addition ratio of the ionic compound to the surfactant satisfies: 2≤ionic compound / surfactant≤30; the mass addition ratio of the polyether polyol to the polyester polyol satisfies: 5≤polyether polyol / polyester polyol≤25.

3. The surface protection film according to claim 1, wherein The crosslinking density of the urethane prepolymer is 76% to 80%.

4. The surface protection film according to claim 1, wherein The molecular weight of the polyether polyol is 50,000 to 100,000, and the PDI is 5 to 10.

5. The surface protection film according to claim 1, wherein The molecular weight of the polyester polyol is 30,000 to 80,000, and the PDI is 5 to 10.

6. The surface protection film according to claim 1, wherein The equivalent ratio of the NCO group of the organic polyisocyanate compound to the OH group of the first polyol is 1.0 to 2.0 in terms of NCO group / OH group.

7. The surface protection film according to claim 1, wherein The surface energy of the urethane prepolymer is 38 mN / m to 43 mN / m.

8. The surface protection film according to claim 1, wherein The surfactant is specifically selected from at least one of a fluorine-based compound containing a hydroxyl group and a fluorine-based compound containing a crosslinkable functional group.

9. The surface protection film according to claim 1, wherein Based on 100% by mass of the urethane adhesive composition, the content of the antistatic functional agent is 0.1% or more.

10. The surface protection film according to claim 1, wherein The urethane adhesive composition further includes a second polyol and a multifunctional isocyanate compound.

11. The surface protection film according to claim 1, wherein After the surface protection film is attached to glass, when the surface protection film is peeled off at a peeling speed of 15 m / min, the peeling charged voltage is less than 100 V.

12. The surface protection film according to claim 1, wherein After the surface protection film was attached to the copper foil, the copper foil was tested at 20V for 15 minutes, and no corrosion or yellowing of the copper foil was observed.

13. An optical component, characterized in that: The surface protection film according to any one of claims 1 to 12 is attached to the surface of the optical member.

14. An electronic component, characterized in that: The surface protection film according to any one of claims 1 to 12 is attached to the surface of the electronic component.

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