Adhesive composition, adhesive, patch, surface protective film, optical member, and electronic member

Abstract

To provide an adhesive composition with superior coatability and curability, an adhesive produced by curing the adhesive composition, a patch comprising an adhesive layer including the adhesive, a surface protection film comprising an adhesive layer including the adhesive, an optical component comprising the surface protection film, and an electronic component comprising the surface protection film.SOLUTION: An adhesive composition contains a urethane resin including structural units derived from an oxyalkylene polymer and structural units derived from a polyisocyanate compound, the oxyalkylene polymer comprising a first oxyalkylene polymer having 4 to 20 hydroxyl groups per molecule and having a number average molecular weight of 2,000 to 100,000.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a pressure-sensitive adhesive composition, a pressure-sensitive adhesive, a patch, a surface protection film, an optical component, and an electronic component, and in particular to a pressure-sensitive adhesive composition having excellent coatability and curability, a pressure-sensitive adhesive obtained by curing the pressure-sensitive adhesive composition, a patch having a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive, a surface protection film having a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive, an optical component having the surface protection film, and an electronic component having the surface protection film. [Background technology]

[0002] Conventionally, flat panel displays (liquid crystal displays, organic electroluminescence displays, etc.) widely used in electronic devices such as televisions, personal computers (PCs), mobile phones, and mobile terminals, as well as touch panel displays that combine a flat panel display with a touch panel, have widely used surface protection films that have a pressure-sensitive adhesive layer formed on a base layer to protect the surfaces of these devices.

[0003] As a pressure-sensitive adhesive composition used in the pressure-sensitive adhesive layer, a urethane-based pressure-sensitive adhesive composition obtained by reacting a polyol with a polyisocyanate is widely known (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-28876 [Patent Document 2] Japanese Patent Application Laid-Open No. 2023-145349 Summary of the Invention [Problem to be solved by the invention]

[0005] However, these pressure-sensitive adhesive compositions have problems in that they are insufficient in coatability and curability. A pressure-sensitive adhesive composition having excellent coatability and curability has not yet been obtained, and there has been a strong demand for the development of a pressure-sensitive adhesive composition having excellent coatability and curability.

[0006] In view of the above problems, the present invention aims to provide a pressure-sensitive adhesive composition having excellent coatability and curability, a pressure-sensitive adhesive obtained by curing the pressure-sensitive adhesive composition, a patch having a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive, a surface protection film having a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive, an optical component having the surface protection film, and an electronic component having the surface protection film. [Means for solving the problem]

[0007] As a result of intensive research into solving the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by using a pressure-sensitive adhesive composition containing a urethane resin having structural units derived from an oxyalkylene polymer, including a specified first oxyalkylene polymer, and structural units derived from a polyisocyanate compound, and have thus completed the present invention. That is, the present invention is as follows. [1] A pressure-sensitive adhesive composition comprising a urethane resin having a structural unit derived from an oxyalkylene polymer and a structural unit derived from a polyisocyanate compound, wherein the oxyalkylene polymer comprises a first oxyalkylene polymer having 4 to 20 hydroxyl groups per molecule and a number average molecular weight of 2,000 to 100,000. [2] The pressure-sensitive adhesive composition according to the above [1], wherein the first oxyalkylene polymer has a number average molecular weight of 3,000 to 100,000. [3] The pressure-sensitive adhesive composition according to the above [1] or [2], wherein the first oxyalkylene polymer has 4 to 8 hydroxyl groups per molecule. [4] The pressure-sensitive adhesive composition according to any one of the above [1] to [3], wherein the oxyalkylene polymer further contains a second oxyalkylene polymer having 1 to 3 hydroxyl groups per molecule and a number average molecular weight of 500 to 100,000. [5] The pressure-sensitive adhesive composition according to any one of the above [1] to [4], wherein the urethane resin is obtained by reacting the polyisocyanate compound with at least one of the oxyalkylene polymer and a hydroxyl-terminated prepolymer obtained by a urethanization reaction of the oxyalkylene polymer and a diisocyanate compound. [6] A pressure-sensitive adhesive which is a cured product of the pressure-sensitive adhesive composition according to any one of the above [1] to [5]. [7] A patch comprising a base layer and an adhesive layer provided on at least one surface of the base layer, the adhesive layer comprising the adhesive described in [6] above. [8] A surface protection film comprising a base layer and a pressure-sensitive adhesive layer provided on at least one surface of the base layer, the pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive described in [6] above. [9] An optical member having the surface protective film according to [8] above.

[10] An electronic component having the surface protection film according to [8] above. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a pressure-sensitive adhesive composition having excellent coatability and curability, a pressure-sensitive adhesive obtained by curing the pressure-sensitive adhesive composition, a patch having a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive, a surface protection film having a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive, an optical component having the surface protection film, and an electronic component having the surface protection film. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view of an electronic component of a surface protection film of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] In this specification, the definitions and meanings of terms are as follows. In this specification, what is considered to be preferable can be adopted arbitrarily, and it can be said that a combination of preferable things is more preferable. In addition, in this specification, the expression "XX to YY" means "XX or more and YY or less." Furthermore, in this specification, for preferred numerical ranges (e.g., ranges of content, etc.), the lower and upper limits described in stages can be independently combined. For example, the description "preferably 10 to 90, more preferably 30 to 60" can be combined with the "preferable lower limit (10)" and the "more preferable upper limit (60)" to form "10 to 60." Furthermore, in the numerical ranges described in this specification, the upper or lower limit of the numerical range may be replaced with a value shown in the examples. In this specification, the "structural unit" constituting the urethane resin means an atomic group formed by the polymer. In this specification, the term "oxyalkylene polymer" refers to a polymer having a polyoxyalkylene chain, and a repeating unit based on alkylene oxide is referred to as an "alkylene oxide unit." In this specification, an oxyalkylene polymer derived from an initiator having 4 to 20 hydroxyl groups includes an oxyalkylene polymer having 4 to 20 hydroxyl groups per molecule. Furthermore, in this specification, for example, in the examples described later, an oxyalkylene polymer (a-1) is prepared using a polyether polyol (intermediate polyol A) obtained by ring-opening polymerization of sorbitol with propylene oxide in the presence of an alkali metal catalyst until the hydroxyl group-equivalent molecular weight reaches 880. In this case, the initiator for the oxyalkylene polymer (a-1) is not the "polyether polyol (intermediate polyol A)" but the starting material "sorbitol." In addition, in this specification, when a mixture of oxyalkylene polymers is purchased, the type and molar ratio of the initiator of the oxyalkylene polymer are 13 By identifying the oxyalkylene polymer using C-NMR, the average number of hydroxyl groups of the oxyalkylene polymer can be calculated. On the other hand, when the oxyalkylene polymer is produced from each initiator, the number of hydroxyl groups of the initiator used is the average number of hydroxyl groups of the oxyalkylene polymer, and the average number of hydroxyl groups of the oxyalkylene polymer can be determined from the number of hydroxyl groups of the initiator used. In this specification, the "hydroxyl value-based molecular weight" is a molecular weight measured or calculated by the method described in the examples below. In addition, in this specification, the "solid content" can be calculated from the change in weight before and after drying a PSA composition containing the solid content in an oven at 130°C using the formula "solid content (%) = weight after drying / weight before drying × 100".

[0011] (Adhesive composition) The pressure-sensitive adhesive composition of the present invention contains a urethane resin, and further contains other components as required. The urethane resin has structural units derived from an oxyalkylene polymer and structural units derived from a polyisocyanate compound, and further contains other structural units as necessary. The urethane resin can be obtained, for example, by reacting (1) at least one of an oxyalkylene polymer and a hydroxyl-terminated prepolymer obtained by a urethane reaction of an oxyalkylene polymer and a diisocyanate compound with (2) a polyisocyanate compound. The ratio of structural units derived from an oxyalkylene polymer to all structural units in the urethane resin is not particularly limited, but from the viewpoint of coatability and adhesive strength, it is preferably 50 to 98 mass%, more preferably 55 to 96 mass%, and particularly preferably 60 to 95 mass%. The proportion of structural units derived from polyisocyanate compounds relative to all structural units in the urethane resin is not particularly limited, but from the viewpoint of curability and coatability, it is preferably 2 to 50 mass %, more preferably 4 to 45 mass %, and particularly preferably 5 to 40 mass %.

[0012] The content of the urethane resin in the pressure-sensitive adhesive composition of the present invention is not particularly limited, but is preferably 10 to 100% by mass, more preferably 15 to 95% by mass, and particularly preferably 18 to 90% by mass. When the content of the urethane resin is within the above range, the effects of the present invention, namely, coatability, curability, and adhesive strength, are easily obtained. The solid content of the pressure-sensitive adhesive composition of the present invention is not particularly limited, but is preferably 10 to 100% by mass, more preferably 15 to 95% by mass, and particularly preferably 18 to 90% by mass. When the solid content is within the above range, the solid content tends to be dispersed well.

[0013] <Oxyalkylene polymer (A)> The oxyalkylene polymer (A) (hereinafter also referred to as polymer (A)) contains a first oxyalkylene polymer having 4 to 20 hydroxyl groups per molecule and a number average molecular weight of 2,000 to 100,000, and may contain other components as necessary. Polymer (A) may include multiple oxyalkylene polymers (eg, a first oxyalkylene polymer and a second oxyalkylene polymer).

[0014] <<First oxyalkylene polymer (a)>> The number of hydroxyl groups per molecule of the first oxyalkylene polymer (a) is not particularly limited as long as it is 4 to 20, but from the viewpoints of curability, adhesive strength, and resin strength, it is preferably 4 to 12, more preferably 4 to 8, and particularly preferably 4 to 6.

[0015] The number average molecular weight of the first oxyalkylene polymer (a) is not particularly limited as long as it is 2,000 to 100,000, but from the viewpoints of coatability, adhesive strength, and resin flexibility (elongation characteristics), it is preferably 3,000 to 100,000, more preferably 5,000 to 80,000, and particularly preferably 7,000 to 50,000.

[0016] <<Second oxyalkylene polymer (b)>> The number of hydroxyl groups per molecule of the second oxyalkylene polymer (b) is not particularly limited as long as it is 1 to 3, but is preferably 2 to 3 from the viewpoint of coatability and flexibility (elongation characteristics) of the resin.

[0017] The number average molecular weight of the second oxyalkylene polymer (b) is not particularly limited, but from the viewpoints of coatability, adhesive strength, and resin flexibility (elongation characteristics), it is preferably 500 to 100,000, more preferably 1,000 to 50,000, and particularly preferably 1,200 to 20,000.

[0018] The average number of hydroxyl groups per molecule of the polymer (A) is not particularly limited, but is preferably 2.5 or more, more preferably 2.8 to 8.0, and particularly preferably 3.1 to 6.0. When the average number of hydroxyl groups in the polymer (A) is within the above range, the adhesive strength of the resulting pressure-sensitive adhesive to the base layer can be kept within an appropriate range.

[0019] The average number of hydroxyl groups per molecule of polymer (A) is 13 It can be calculated by identifying the type and molar ratio of the initiator using C-NMR. 13 In C-NMR analysis, characteristic peaks of the initiator are observed, and the type and molar ratio of the initiator can be identified from the peak position and peak area. Usually, the number of hydroxyl groups per molecule of an oxyalkylene polymer is equal to the number of hydroxyl groups per molecule of the initiator used in synthesizing the oxyalkylene polymer. When an oxyalkylene polymer is synthesized using, for example, sorbitol as an initiator, an oxyalkylene polymer having 6 hydroxyl groups per molecule is usually obtained. Furthermore, when an oxyalkylene polymer is synthesized using, for example, pentaerythritol as an initiator, an oxyalkylene polymer having four hydroxyl groups per molecule is usually obtained. Furthermore, when an oxyalkylene polymer is synthesized using, for example, glycerin as an initiator, an oxyalkylene polymer having three hydroxyl groups per molecule is usually obtained. Furthermore, when an oxyalkylene polymer is synthesized using, for example, dipropylene glycol (propylene glycol) as an initiator, an oxyalkylene polymer having two hydroxyl groups per molecule is usually obtained. The average number of hydroxyl groups per molecule of polymer (A) can also be calculated from the number of hydroxyl groups per molecule based on the type of initiator and the molar fraction of the initiator. For example, if the oxyalkylene polymer polymerized using glycerin as an initiator is 30 mol % and the oxyalkylene polymer polymerized using dipropylene glycol as an initiator is 70 mol %, the average number of hydroxyl groups is 3 × 0.3 + 2 × 0.7 = 2.3.

[0020] The alkylene oxide used in synthesizing the polymer (A) may or may not contain ethylene oxide (EO), or may or may not contain propylene oxide (PO). The alkylene oxide used in synthesizing the polymer (A) may be EO alone, PO alone, or a combination of EO and PO. When two or more alkylene oxides are subjected to ring-opening addition, the arrangement of units derived from each alkylene oxide may be random, block, or tapered. Here, when the arrangement of EO units and PO units is random, polymer (A) may usually have a block of PO units and a random of EO units and PO units, or may have a block of EO units and a random of EO units and PO units. Furthermore, when the arrangement of EO units and PO units is block, polymer (A) may have a block of PO units, a block of EO units, and a block of PO units in this order (a "PO block-EO block-PO block" structure), or a block of EO units, a block of PO units, and a block of EO units in this order (a "EO block-PO block-EO block" structure). Furthermore, when the arrangement of EO units and PO units is tapered, the oxyalkylene polymer (A) may generally have blocks of PO units, random units of EO units and PO units, and blocks of EO units. When EO, PO, and an alkylene oxide other than EO and PO are used in combination as the alkylene oxide, the molar ratio of EO units, PO units, and alkylene oxide units other than EO units and PO units is appropriately selected. The higher the EO unit content, the more improved the hydrophilicity of the polymer (A), and the lower the EO unit content, the more likely the crystallinity of the polymer (A) is to be reduced. Furthermore, when the polymer (A) has an EO unit at the end, the end is a primary hydroxyl group, and therefore the reactivity with polyisocyanate compounds tends to be higher than when the polymer (A) has a PO unit at the end.

[0021] The EO unit content relative to the total amount of oxyalkylene groups in the polymer (A) is not particularly limited, and is preferably 0 to 40 mass %, more preferably 0 to 30 mass %, and particularly preferably 0 to 20 mass %. If the EO unit content relative to the total amount of oxyalkylene groups in the polymer (A) is within the above range, it is preferable from the viewpoints of coatability, curability, and water resistance of the resin.

[0022] The content of EO units relative to the total amount of oxyalkylene groups in the polymer (A) is 13 It is calculated by determining the monomer unit composition of the oxyalkylene chain using C-NMR. For example, when the polymer (A) is a polyol consisting of PO units and EO units, the EO unit content can be determined from the area ratio of the signal of the methyl group in the propylene oxide unit to the signal of the methylene group in the PO unit and the EO unit.

[0023] The PO unit content relative to the total amount of oxyalkylene groups in the polymer (A) is not particularly limited, but is preferably 60 to 100 mass %, more preferably 70 to 100 mass %, and particularly preferably 80 to 100 mass %. When the PO unit content relative to the total amount of oxyalkylene groups in the polymer (A) is within the above range, the polymer becomes amorphous and is therefore easy to handle, which is preferable from the viewpoint of adhesiveness and water resistance of the resin.

[0024] The PO unit content relative to the total amount of oxyalkylene groups in the polymer (A) is13 It is calculated by determining the monomer unit composition of the oxyalkylene chain using C-NMR. For example, when the polymer (A) is a polyol consisting of PO units and EO units, the PO unit content can be determined from the area ratio of the signal of the methyl group in the propylene oxide unit to the signal of the methylene group in the PO unit and the EO unit.

[0025] The hydroxyl value-based molecular weight of the polymer (A) is not particularly limited, but from the viewpoint of improving the flexibility of the resulting pressure-sensitive adhesive, it is preferably 1,000 to 100,000, more preferably 3,000 to 90,000, even more preferably 5,000 to 80,000, and particularly preferably 6,000 to 70,000. When two or more polymers (A) are contained, it is preferable that the hydroxyl value-based molecular weight of each polymer (A) is within the above-mentioned preferred range.

[0026] The number average molecular weight (Mn) of the polymer (A) is not particularly limited, but from the viewpoint of improving the flexibility of the resulting pressure-sensitive adhesive, it is preferably 1,000 to 100,000, more preferably 3,000 to 90,000, even more preferably 5,000 to 80,000, and particularly preferably 6,000 to 70,000. The number average molecular weight (Mn) per average number of hydroxyl groups of the polymer (A) is not particularly limited, but from the viewpoint of improving the flexibility of the resulting pressure-sensitive adhesive, it is preferably 1,000 to 9,000, more preferably 1,500 to 8,500, even more preferably 2,000 to 8,000, and particularly preferably 2,500 to 7,000. When two or more types of polymers (A) are contained, it is preferable that the Mn of each of the polymers (A) is within the above preferred range.

[0027] The molecular weight distribution (ratio of weight average molecular weight to number average molecular weight (Mw / Mn)) of the polymer (A) is not particularly limited, but from the viewpoint of easily achieving good reactivity and more easily reducing viscosity, it is preferably less than 1.40, more preferably less than 1.20, and particularly preferably less than 1.15. When two or more types of polymers (A) are contained, it is preferable that the Mw / Mn of each polymer (A) is within the above preferred range.

[0028] The Mn and Mw / Mn of the polymer (A) are values ​​obtained by measurement according to the method described below. As standard samples for molecular weight measurement, several types of monodisperse polystyrenes with different degrees of polymerization are measured using a commercially available GPC measurement device (e.g., HLC-8420GPC, manufactured by Tosoh Corporation), and a calibration curve is created based on the relationship between the molecular weight of polystyrene and retention time. The measurement sample, polymer (A), is diluted to 0.5% by mass with tetrahydrofuran and passed through a filter with a pore size of 0.5 μm, and then the measurement sample is measured using the above-mentioned GPC measurement device. Using the above-mentioned calibration curve, the GPC spectrum of the measurement sample is analyzed by computer to determine the Mn and Mw of the measurement sample. The molecular weight distribution (Mw / Mn) is a value calculated from the above Mw and Mn.

[0029] The degree of unsaturation of the polymer (A) is not particularly limited, but from the viewpoint of improving the curability of the pressure-sensitive adhesive composition, it is preferably 0.100 meq / g or less, more preferably 0.070 meq / g or less, and even more preferably 0.050 meq / g or less. The degree of unsaturation of the polymer (A) may be zero. The degree of unsaturation of the polymer (A) is a value measured according to the method of JIS K 1557-3:2007. When two or more types of polymers (A) are contained, it is preferable that the degree of unsaturation of each polymer (A) is within the above-mentioned preferred range.

[0030] The hydroxyl value of the polymer (A) is not particularly limited, but from the viewpoint of improving the flexibility of the resulting adhesive, it is preferably 2 to 100 mgKOH / g, more preferably 5 to 80 mgKOH / g, and particularly preferably 8 to 60 mgKOH / g. When two or more types of polymers (A) are contained, it is preferable that the hydroxyl value of each polymer (A) is within the above preferred range. The hydroxyl value of the polymer (A) is a value calculated by measurement in accordance with Method B of JIS K 1557-1:2007.

[0031] In one embodiment of the present invention, the polymer (A) may comprise a first oxyalkylene polymer (a) (hereinafter referred to as "polymer a") having 4 to 20 hydroxyl groups per molecule and a second oxyalkylene polymer (b) (hereinafter referred to as "polymer b") having 1 to 3 hydroxyl groups per molecule. When the polymer (A) contains the polymer a and the polymer b, the coating properties to the base layer and the flexibility (elongation properties) of the resin are good, and the adhesive strength to the base layer can be easily adjusted to a more appropriate range.

[0032] The mass proportion of polymer a in polymer (A) is not particularly limited as long as it is more than 0 mass%, and is preferably 30 to 100 mass%, more preferably 50 to 100 mass%, and particularly preferably 70 to 100 mass%.

[0033] The mass ratio of polymer a contained in polymer (A) is, for example, 13 The type and molar ratio of the initiator contained in the polymer (A) can be identified using C-NMR, and the ratio can be calculated as the ratio of the peak areas.

[0034] To synthesize polymer a, an initiator having 4 to 20 hydroxyl groups per molecule is used. The initiator having 4 to 20 hydroxyl groups per molecule is not particularly limited, and examples thereof include tetrahydric or higher polyhydric alcohols such as diglycerin, polyglycerin, pentaerythritol, dipentaerythritol, and tripentaerythritol; sugars or derivatives thereof such as glucose, sorbitol, dextrose, fructose, sucrose, and methyl glucoside; and the like. These may be used alone or in combination of two or more. Among these, sorbitol and pentaerythritol are preferred.

[0035] The alkylene oxide used in the synthesis of polymer a is the same as the alkylene oxide used in the synthesis of the above-mentioned polymer (A). If the raw materials used in the synthesis of polymer (A) contain moisture, the alkylene oxide may undergo addition polymerization using water as an initiator to produce a polymer having two hydroxyl groups per molecule (corresponding to polymer b) as a by-product. The by-product may be contained in polymer (A).

[0036] The mass proportion of polymer b in polymer (A) is not particularly limited as long as it is less than 100 mass%, but is preferably 0 to 70 mass%, more preferably 0 to 50 mass%, and particularly preferably 0 to 30 mass%.

[0037] The mass proportion of polymer b contained in polymer (A) can be calculated in the same manner as in the calculation of the mass proportion of polymer a contained in polymer (A) described above.

[0038] To synthesize the polymer b, an initiator having 1 to 3 hydroxyl groups in one molecule is used. The initiator having 1 to 3 hydroxyl groups per molecule for synthesizing polymer b is not particularly limited, and examples thereof include initiators having 3 hydroxyl groups per molecule, such as glycerin and trimethylolpropane; initiators having 2 hydroxyl groups per molecule, such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; propanol (n-propyl alcohol); 2-propanol (isopropyl alcohol); 1-butanol (n-butyl alcohol); 2-butanol (sec-butyl alcohol); 2-methyl-1-propanol (isobutyl alcohol); 2-methyl-2-propanol (tert-butyl alcohol); monohydric alcohols having 2 to 4 carbon atoms (initiators having one hydroxyl group per molecule), such as 1-butanol (n-butyl alcohol), 2-butanol (sec-butyl alcohol), 2-methyl-1-propanol (isobutyl alcohol), and 2-methyl-2-propanol (tert-butyl alcohol); and the like. These may be used alone or in combination of two or more. Among these, glycerin and propylene glycol are preferred from the viewpoint of availability at low cost.

[0039] The alkylene oxide used in the synthesis of polymer b is the same as the alkylene oxide used in the synthesis of polymer (A) described above, and the preferred embodiments are also the same.

[0040] The catalyst for ring-opening addition polymerization of an alkylene oxide to an initiator is not particularly limited, and a conventionally known catalyst can be used, for example, an alkali catalyst such as KOH, a transition metal compound-porphyrin complex catalyst such as a complex obtained by reacting an organoaluminum compound with porphyrin, a composite metal cyanide complex catalyst (DMC catalyst), or a catalyst composed of a phosphazene compound. The amount of catalyst used can be a conventionally known amount. For example, when a DMC catalyst is used, the amount used is preferably such that the metal concentration of the DMC catalyst in the reaction liquid is 1 to 500 ppm by mass. When the oxyalkylene polymer (A) is obtained using a DMC catalyst, it is preferable from the viewpoint that the molecular weight distribution of the obtained oxyalkylene polymer (A) can be narrowed and an oxyalkylene polymer (A) having a low viscosity can be easily obtained. The DMC catalyst is not particularly limited, and a conventionally known compound can be used. A known method can also be used for producing a polymer using a DMC catalyst. For example, the compounds and production methods disclosed in WO 2003 / 062301, WO 2004 / 067633, JP 2004-269776 A, JP 2005-015786 A, WO 2013 / 065802, JP 2015-010162 A, and the like can be used. As a method for obtaining polymer (A) by ring-opening addition polymerization of alkylene oxide to an initiator, a conventionally known method can be used, and for example, the production methods disclosed in WO 2011 / 125951, Japanese Patent No. 5648797, etc. can be used.

[0041] <Hydroxyl-terminated urethane prepolymer (X)> The hydroxyl-terminated urethane prepolymer (X) is a hydroxyl-terminated urethane prepolymer obtained, for example, by subjecting the above-mentioned polymer (A) to a urethane reaction with a diisocyanate. The diisocyanate is not particularly limited, and examples thereof include 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, xylene diisocyanate (XDI), 3,3'-dimethoxy-4,4'-diphenylmethane diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 4,4'-diphenylether diisocyanate, 3,3'-dimethyl-4,4'-diphenylether diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-bis(1-isocyanato-1-methylethyl)benzene, tetramethylene diisocyanate, hexamethylene diisocyanate, Examples of the isocyanate include HDI, pentamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, dodecamethylene diisocyanate, lysine diisocyanate, 2-methylpentane-1,5-diisocyanate, 3-methylpentane-1,5-diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate (HMDI), norbornane diisocyanate (NBDI), hydrogenated xylene diisocyanate, 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, dicyclohexanemethane diisocyanate (HMDI), tetramethylxylylene diisocyanate, etc. These may be used alone or in combination of two or more.

[0042] The EO unit content relative to the total amount of oxyalkylene groups in the hydroxyl group-terminated urethane prepolymer (X) is not particularly limited, but is preferably 0 to 40 mass %, more preferably 0 to 30 mass %, and particularly preferably 0 to 20 mass %. It is preferable from the viewpoint of coatability and water resistance of the resin that the EO unit content relative to the total amount of oxyalkylene groups in the hydroxyl group-terminated urethane prepolymer (X) is within the above range.

[0043] The EO unit content relative to the total amount of oxyalkylene groups in the hydroxyl group-terminated urethane prepolymer (X) is 13 It is calculated by determining the monomer unit composition of the oxyalkylene chain using C-NMR. For example, when the hydroxyl group-terminated urethane prepolymer (X) is a reaction product of a polyol consisting of PO units and EO units with a diisocyanate, the EO unit content can be determined from the area ratio of the methyl group signal in the propylene oxide unit to the methylene group signals in the PO units and EO units.

[0044] The PO unit content relative to the total amount of oxyalkylene groups in the hydroxyl group-terminated urethane prepolymer (X) is not particularly limited, but is preferably 60 to 100 mass%, more preferably 70 to 100 mass%, and particularly preferably 80 to 100 mass%. When the PO unit content relative to the total amount of oxyalkylene groups in the hydroxyl group-terminated urethane prepolymer (X) is within the above range, the prepolymer becomes amorphous and is therefore easy to handle, which is preferable from the viewpoint of adhesiveness and water resistance of the resin.

[0045] The PO unit content relative to the total amount of oxyalkylene groups in the hydroxyl group-terminated urethane prepolymer (X) is 13 It is calculated by determining the monomer unit composition of the oxyalkylene chain using C-NMR. For example, when the hydroxyl group-terminated urethane prepolymer (X) is a reaction product of a polyol consisting of PO units and EO units with a diisocyanate, the PO unit content can be determined from the area ratio of the signal of the methyl group in the propylene oxide unit to the signal of the methylene group in the PO units and the EO units.

[0046] There are no particular restrictions on the hydroxyl value-based molecular weight of the hydroxyl-terminated urethane prepolymer (X), but from the viewpoint of improving the flexibility of the resulting pressure-sensitive adhesive, it is preferably 2,000 to 1,000,000, more preferably 6,000 to 900,000, and particularly preferably 10,000 to 800,000. When two or more types of hydroxyl group-terminated urethane prepolymers (X) are contained, it is preferable that the hydroxyl value-equivalent molecular weight of each of the hydroxyl group-terminated urethane prepolymers (X) is within the above-mentioned preferred range.

[0047] The number average molecular weight (Mn) of the hydroxyl group-terminated urethane prepolymer (X) is not particularly limited, but from the viewpoint of improving the flexibility of the resulting pressure-sensitive adhesive, it is preferably 2,000 to 1,000,000, more preferably 6,000 to 900,000, and particularly preferably 10,000 to 800,000. When two or more types of hydroxyl group-terminated urethane prepolymers (X) are contained, it is preferable that the Mn of each of the hydroxyl group-terminated urethane prepolymers (X) is within the above-mentioned preferred range.

[0048] The molecular weight distribution (ratio of weight average molecular weight to number average molecular weight (Mw / Mn)) of the hydroxyl group-terminated urethane prepolymer (X) is not particularly limited, but from the viewpoint of easily achieving good reactivity and more easily reducing viscosity, it is preferably less than 5.0, more preferably less than 4.0, and particularly preferably less than 3.0. When two or more types of hydroxyl group-terminated urethane prepolymers (X) are contained, it is preferable that the Mw / Mn of each of the hydroxyl group-terminated urethane prepolymers (X) is within the above-mentioned preferred range.

[0049] The Mn and Mw / Mn of the hydroxyl group-terminated urethane prepolymer (X) are values ​​obtained by measurement according to the method described below. As standard samples for molecular weight measurement, several types of monodisperse polystyrenes with different degrees of polymerization are measured using a commercially available GPC measurement device (e.g., HLC-8420GPC, manufactured by Tosoh Corporation), and a calibration curve is created based on the relationship between the molecular weight of the polystyrene and retention time.The measurement sample, a hydroxyl-terminated urethane prepolymer (X), is diluted to 0.5% by mass with tetrahydrofuran and passed through a filter with a pore size of 0.5 μm.The measurement sample is then measured using the GPC measurement device.The GPC spectrum of the measurement sample is then analyzed by computer using the calibration curve to determine the Mn and Mw of the measurement sample. The molecular weight distribution (Mw / Mn) is a value calculated from the above Mw and Mn.

[0050] The degree of unsaturation of the hydroxyl-terminated urethane prepolymer (X) is not particularly limited, but from the viewpoint of improving the curability of the pressure-sensitive adhesive composition, it is preferably 0.100 meq / g or less, more preferably 0.070 meq / g or less, and particularly preferably 0.050 meq / g or less. The degree of unsaturation of the hydroxyl-terminated urethane prepolymer (X) may be zero. The degree of unsaturation of the hydroxyl group-terminated urethane prepolymer (X) is a value measured according to the method of JIS K 1557-3:2007. When two or more types of hydroxyl group-terminated urethane prepolymers (X) are contained, it is preferable that the degree of unsaturation of each of the hydroxyl group-terminated urethane prepolymers (X) is within the above-mentioned preferred range.

[0051] The hydroxyl value of the hydroxyl-terminated urethane prepolymer (X) is not particularly limited, but from the viewpoint of improving the flexibility of the resulting adhesive, it is preferably 1 to 80 mgKOH / g, more preferably 2 to 60 mgKOH / g, and particularly preferably 3 to 40 mgKOH / g. When two or more types of hydroxyl group-terminated urethane prepolymers (X) are contained, it is preferable that the hydroxyl value of each of the hydroxyl group-terminated urethane prepolymers (X) is within the above-mentioned preferred range. The hydroxyl value of the hydroxyl-terminated urethane prepolymer (X) is a value calculated by measurement in accordance with Method B of JIS K 1557-1:2007.

[0052] <Polyisocyanate compound (Y)> The polyisocyanate compound (Y) is a compound having two or more isocyanate groups in one molecule. The polyisocyanate compound (Y) may also be a blocked isocyanate that can be converted to a polyisocyanate compound by deblocking or the like.

[0053] The viscosity of the polyisocyanate compound (Y) at 25°C is preferably 20 to 10,000 mPa·s, more preferably 100 to 7,000 mPa·s, and particularly preferably 200 to 5,000 mPa·s, from the viewpoint of easy mixing with at least one of the polymer (A) and the hydroxyl group-terminated urethane prepolymer (X). The viscosity of the polyisocyanate compound (Y) at 25° C. can be measured with an E-type viscometer.

[0054] Specific examples of the polyisocyanate compound (Y) are not particularly limited, and include, for example, linear or branched polyisocyanates such as tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate (HDI), 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, dodecamethylene diisocyanate, lysine diisocyanate, 2-methylpentane-1,5-diisocyanate, and 3-methylpentane-1,5-diisocyanate. Aliphatic polyisocyanates: toluene diisocyanate (TDI), 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, polymethylene polyphenylene polyisocyanate, xylylene diisocyanate (XDI), α,α,α',α'-tetramethylxylylene diisocyanate, 4,4'-dibenzyl diisocyanate Aromatic polyisocyanates such as isocyanate, tolidine diisocyanate, and 1,5-naphthalene diisocyanate; isophorone diisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate (HMDI), norbornane diisocyanate (NBDI), hydrogenated xylylene diisocyanate, 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, 1,3-bis(isocyanatemethyl)cyclohexane, and dicyclohexylmethane diisocyanate Examples of suitable diisocyanate compounds include alicyclic polyisocyanates such as methyl methyl acrylate (H12MDI), isocyanurate-modified products of the various diisocyanate compounds described above, biuret-modified products of the various diisocyanate compounds described above, allophanate-modified products of the various diisocyanate compounds described above, bifunctional or higher isocyanate-terminated urethane prepolymers (adducts) obtained by reacting the various diisocyanate compounds described above with polyols having two or more hydroxyl groups in one molecule, and deblocked products of blocked isocyanates. These may be used alone or in combination of two or more.

[0055] Commercially available isocyanurate-modified products are not particularly limited, and examples thereof include Duranate TPA-100, Duranate TKA-100 (manufactured by Asahi Kasei Corporation), and Coronate HX (manufactured by Tosoh Corporation). These may be used alone or in combination of two or more. Among these, Coronate HX (manufactured by Tosoh Corporation) is preferred. Commercially available biuret-modified products are not particularly limited, and examples thereof include Duranate 24A-100 and Duranate 22A-75P (manufactured by Asahi Kasei Corporation). These may be used alone or in combination of two or more. Commercially available tri- or higher functional isocyanate group-terminated urethane prepolymers are not particularly limited, and examples thereof include Coronate L, Coronate L-55E, and Coronate L-45E (all manufactured by Tosoh Corporation). These may be used alone or in combination of two or more. Commercially available water-dispersible polyisocyanates are not particularly limited, and examples thereof include Duranate WB40-100, Duranate WB40-80D, Duranate WT20-100, Duranate WT30-100, Duranate WL70-100, Duranate WE50-100, and Duranate WR80-70P (all manufactured by Asahi Kasei Corporation), Aquanate 105, Aquanate 130, Aquanate 140 (AQ-140), Aquanate 200, and Aquanate 140 (AQ-140). 210 (all manufactured by Tosoh Corporation), Takenate WD series (Takenate WD-720, Takenate WD-725, Takenate WD-220, Takenate XWD-HS7, Takenate XWD-HS30, etc.) (all manufactured by Mitsui Chemicals Co., Ltd.), Bayhydur 3100, Bayhydur XP2487 / 1 (all manufactured by Bayer MaterialScience), Basonat HW100, Basonat HA100 (all manufactured by BASF), etc. These may be used alone or in combination of two or more. Commercially available blocked isocyanates are not particularly limited and include, for example, SU-268A, NBP-211, Meikanate CX, Meikanate TP-10, and DM-6400 (all manufactured by Meisei Chemical Industry Co., Ltd.); WM44-L70G (manufactured by Asahi Kasei Corporation); Aqua BI200 and Aqua BI220 (both manufactured by Baxenden Chemicals); Takelac W and Takelac WPB (both manufactured by Mitsui Chemicals, Inc.); Burnock (manufactured by DIC Corporation); and Elastron (manufactured by Daiichi Kogyo Co., Ltd.). These may be used alone or in combination of two or more.

[0056] The isocyanate index when at least one of the oxyalkylene polymer (A) and the hydroxyl-terminated urethane prepolymer (X) is reacted with the polyisocyanate compound (Y) to produce the pressure-sensitive adhesive composition of the present invention is not particularly limited, but is preferably more than 100 and not more than 1,500, more preferably 120 to 1,000, even more preferably 150 to 800, and particularly preferably 200 to 500. The isocyanate index is a value obtained by multiplying the ratio of the number of moles of isocyanate groups in the polyisocyanate compound (Y) to the number of moles of all hydroxyl groups contained in the oxyalkylene polymer (A) and the hydroxyl-terminated urethane prepolymer (X) by 100.

[0057] The content of the polyisocyanate compound (Y) is not particularly limited, but is preferably 1 to 50 parts by mass, more preferably 1.5 to 45 parts by mass, and particularly preferably 2 to 40 parts by mass, per 100 parts by mass of the oxyalkylene polymer (A) and the hydroxyl group-terminated urethane prepolymer (X) combined.

[0058] <Other ingredients> The pressure-sensitive adhesive composition of the present invention may contain, as other components, antioxidants, solvents, hydrolysis inhibitors, ultraviolet absorbers, light stabilizers, antistatic agents, leveling agents, raw materials used in preparing the oxyalkylene polymer (A), such as alkylene oxide, polyol (initiator), and catalysts for ring-opening addition polymerization of alkylene oxide, and other optional components, etc. These may be used alone or in combination of two or more.

[0059] <<Antioxidants>> The antioxidant is not particularly limited, and examples thereof include radical scavengers such as phenolic compounds and amine compounds; peroxide decomposers such as sulfur compounds and phosphorus compounds; etc. These may be used alone or in combination of two or more.

[0060] By using an antioxidant, it is possible to prevent thermal deterioration of the oxyalkylene polymer (A) and the hydroxyl group-terminated urethane prepolymer (X). The amount of antioxidant to be added is not particularly limited, but is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 3 parts by mass, and particularly preferably 0.2 to 2 parts by mass, per 100 parts by mass of the oxyalkylene polymer (A) and the hydroxyl group-terminated urethane prepolymer (X) combined.

[0061] -Phenol compounds- The phenolic compound is not particularly limited, and examples thereof include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-methylphenol, 2,6-di-t-butyl-4-ethylphenol, stearin-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,2'-methylenebis(4-methyl-6-t-butylphenol), 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 4,4' -thiobis(3-methyl-6-t-butylphenol), 4,4'-butylidenebis(3-methyl-6-t-butylphenol), 2,2'-dihydroxy-3,3'-di(α-methylcyclohexyl)-5,5'-dimethyldiphenylmethane (Seiko Chemical Co., Ltd. product name CBP), 3,9-bis[1,1-dimethyl-2-[β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane, benzyl Benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, C7-C9 side chain alkyl ester (BASF product name Irganox 1135), 2,6-di-t-butyl-4-(4,6-bis(octylthio)-1,3,5-triazin-2-ylamino)phenol (BASF product name Irganox 565), 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5 -di-t-butyl-4-hydroxybenzyl)benzene, tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, bis[3,3'-bis-(4'-hydroxy-3'-t-butylphenyl)butyric acid]glycol ester, 1,3,5-tris(3',5'-di-t-butyl-4'-hydroxybenzyl)-S-triazine-2,4,6-(1H,3H,5H)trione, tocopherol, etc. These may be used alone or in combination of two or more.

[0062] -Amine compounds- The amine compound is not particularly limited, and examples thereof include a reaction product of N-phenylbenzenamine and 2,4,4-trimethylpentene (trade name: IRGANOX (registered trademark) 5057 (manufactured by BASF Japan Ltd.)), tris(2-[(2,4,8,10-tetrakisbutyldibenzo[d,f][1,3,2]dioxaphosphepin-6-yl)oxy]ethyl)amine, etc. These may be used alone or in combination of two or more.

[0063] -Sulfur compounds- The sulfur-based compound is not particularly limited, and examples thereof include didodecyl-3,3'-thiopropionate, dilauryl-3,3'-thiodipropionate, ditridecyl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, tetrakis-methylene-3-laurylthiopropionate methane, and distearyl-3,3'-methyl Examples of suitable alkyl esters include 2-methyl-4-(3-n-alkylthiopropionyloxy)-5-t-butylphenyl sulfide, β-lauryl thiopropionate, 2-mercaptobenzimidazole, 2-mercapto-5-methylbenzimidazole, and distearyl-3,3'-thiodiprothioate. These may be used alone or in combination of two or more.

[0064] -Phosphorus compounds- The phosphorus-based compound is not particularly limited, and examples thereof include triphenyl phosphite, diphenyl isodecyl phosphite, 4,4'-butylidene-bis(3-methyl-6-tert-butylphenylditridecyl)phosphite, cyclic neopentanetetraylbis(octadecylphosphite), tris(nonylphenyl)phosphite, tris(mononylphenyl)phosphite, tris(dinonylphenyl)phosphite, diisodecylpentaerythritol diphosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(3,5-di-tert -butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-decyloxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene, tris(2,4-di-tert-butylphenyl)phosphite, cyclic neopentanetetraylbis(2,4-di-tert-butylphenyl)phosphite, cyclic neopentanetetraylbis(2,6-di-tert-butyl-4-methylphenyl)phosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl)octylphosphite, etc. These may be used alone or in combination of two or more.

[0065] As the antioxidant, it is preferable to use one or more phenolic compounds as radical scavengers from the viewpoint of stability and antioxidant effect. One or more phenolic compounds as radical scavengers can also be used in combination with one or more phosphorus-based compounds as peroxide decomposers. Furthermore, as the antioxidant, a phenolic compound as a radical scavengers and a phosphorus-based compound as a peroxide decomposer can also be used in combination, and these antioxidants can also be used in combination with a hydrolysis inhibitor described below.

[0066] <<Solvent>> The pressure-sensitive adhesive composition of the present invention may contain a solvent, if necessary. The solvent is not particularly limited, and examples thereof include ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate, aromatic hydrocarbons such as toluene and xylene, etc. These may be used alone or in combination of two or more. The amount of the solvent used is not particularly limited, but is preferably 80 parts by mass or less, more preferably 70 parts by mass or less, and particularly preferably 60 parts by mass or less, per 100 parts by mass of the total of the oxyalkylene polymer (A), the hydroxyl group-terminated urethane prepolymer (X), and the polyisocyanate compound (Y).

[0067] <<Hydrolysis inhibitor>> Examples of the hydrolysis inhibitor include carbodiimide-based, oxazoline-based, epoxy-based, etc. One type of hydrolysis inhibitor may be used alone, or two or more types may be used in combination. Among these, carbodiimide-based compounds are preferred from the viewpoint of the hydrolysis suppression effect.

[0068] -Carbodiimide hydrolysis inhibitor- A carbodiimide hydrolysis inhibitor is a compound having one or more carbodiimide groups in one molecule. The monocarbodiimide compound is not particularly limited, and examples thereof include dicyclohexylcarbodiimide, diisopropylcarbodiimide, dimethylcarbodiimide, diisobutylcarbodiimide, dioctylcarbodiimide, diphenylcarbodiimide, naphthylcarbodiimide, etc. These may be used alone or in combination of two or more. The polycarbodiimide compound can be produced by subjecting a diisocyanate to a decarboxylation condensation reaction in the presence of a carbodiimidization catalyst. The diisocyanate is not particularly limited, and examples thereof include 4,4'-diphenylmethane diisocyanate (MDI), 3,3'-dimethoxy-4,4'-diphenylmethane diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 4,4'-diphenylether diisocyanate, 3,3'-dimethyl-4,4'-diphenylether diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1-methoxyphenyl-2,4-diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, tetramethylxylylene diisocyanate, etc. These may be used alone or in combination of two or more. The carbodiimidization catalyst is not particularly limited, and examples thereof include phospholene oxides such as 1-phenyl-2-phospholene-1-oxide, 3-methyl-2-phospholene-1-oxide, 1-ethyl-3-methyl-2-phospholene-1-oxide, 1-ethyl-2-phospholene-1-oxide, and 3-phospholene isomers thereof. These may be used alone or in combination of two or more.

[0069] -Oxazoline-based hydrolysis inhibitor- The oxazoline-based hydrolysis inhibitor is not particularly limited, and examples thereof include 2,2'-o-phenylenebis(2-oxazoline), 2,2'-m-phenylenebis(2-oxazoline), 2,2'-p-phenylenebis(2-oxazoline), 2,2'-p-phenylenebis(4-methyl-2-oxazoline), 2,2'-m-phenylenebis(4-methyl-2-oxazoline), 2,2'-p-phenylenebis(4,4'-dimethyl-2-oxazoline), Examples of suitable terpolymers include 2,2'-m-phenylenebis(4,4'-dimethyl-2-oxazoline), 2,2'-ethylenebis(2-oxazoline), 2,2'-tetramethylenebis(2-oxazoline), 2,2'-hexamethylenebis(2-oxazoline), 2,2'-octamethylenebis(2-oxazoline), 2,2'-ethylenebis(4-methyl-2-oxazoline), and 2,2'-diphenylenebis(2-oxazoline). These may be used alone or in combination of two or more.

[0070] -Epoxy hydrolysis inhibitor- The epoxy hydrolysis inhibitor is not particularly limited, and examples thereof include diglycidyl ethers of aliphatic diols such as 1,6-hexanediol, neopentyl glycol, and polyalkylene glycol; polyglycidyl ethers of aliphatic polyols such as sorbitol, sorbitan, polyglycerol, pentaerythritol, diglycerol, glycerol, and trimethylolpropane; polyglycidyl ethers of alicyclic polyols such as cyclohexanedimethanol; diglycidyl esters or polyglycidyl esters of aliphatic or aromatic polycarboxylic acids such as terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, trimellitic acid, adipic acid, and sebacic acid; resorcinol, bis-(p-hydroxyphenyl)-2-methylpropanol; Examples of suitable diglycidyl ethers or polyglycidyl ethers include diglycidyl ethers or polyglycidyl ethers of polyhydric phenols such as N,N-diglycidylaniline, N,N-diglycidyltoluidine, and N,N,N',N'-tetraglycidyl-bis(p-aminophenyl)methane; N-glycidyl derivatives of amines such as N,N-diglycidylaniline, N,N-diglycidyltoluidine, and N,N,N',N'-tetraglycidyl-bis(p-aminophenyl)methane; triglycidyl derivatives of aminophenols; triglycidyl tris(2-hydroxyethyl)isocyanurate; triglycidyl isocyanurate; and epoxy resins such as orthocresol epoxy resins and phenol novolac epoxy resins. These may be used alone or in combination of two or more.

[0071] The amount of the hydrolysis inhibitor to be added is not particularly limited, but is preferably 0.1 to 5.0 parts by mass, more preferably 0.2 to 4.5 parts by mass, and particularly preferably 0.5 to 3.0 parts by mass, per 100 parts by mass of the oxyalkylene polymer (A) and the hydroxyl group-terminated urethane prepolymer (X) combined.

[0072] <<Ultraviolet absorber>> The ultraviolet absorber is not particularly limited, and examples thereof include benzophenone compounds, benzotriazole compounds, salicylic acid compounds, oxalic acid anilide compounds, cyanoacrylate compounds, triazine compounds, etc. These may be used alone or in combination of two or more. The amount of the ultraviolet absorber to be added is not particularly limited, but is preferably 0.01 parts by mass or more, more preferably 0.1 to 3.0 parts by mass, even more preferably 0.2 to 2.5 parts by mass, and particularly preferably 0.2 to 2 parts by mass, relative to 100 parts by mass of the total of the oxyalkylene polymer (A) and the hydroxyl group-terminated urethane prepolymer (X).

[0073] <<Light stabilizers>> The light stabilizer is not particularly limited, and examples thereof include hindered amine compounds, hindered piperidine compounds, etc. These may be used alone or in combination of two or more.

[0074] The amount of the light stabilizer to be added is not particularly limited, but is preferably 0.01 to 2 parts by mass, more preferably 0.1 to 1.5 parts by mass, and particularly preferably 0.2 to 1 part by mass, per 100 parts by mass of the oxyalkylene polymer (A) and the hydroxyl group-terminated urethane prepolymer (X) combined.

[0075] <<Antistatic agent>> The antistatic agent is not particularly limited, and examples thereof include inorganic salts, polyhydric alcohol compounds, ionic liquids, surfactants, etc. These may be used alone or in combination of two or more. Among these, ionic liquids are preferred. Note that "ionic liquids" are also called room temperature molten salts, and are salts that are fluid at 25°C.

[0076] The amount of the antistatic agent to be added is not particularly limited, but is preferably 0.01 to 10 parts by mass, more preferably 0.03 to 5 parts by mass, and particularly preferably 0.05 to 3 parts by mass, relative to 100 parts by mass of the total of the oxyalkylene polymer (A) and the hydroxyl group-terminated urethane prepolymer (X).

[0077] -Inorganic salts- The inorganic salt is not particularly limited, and examples thereof include sodium chloride, potassium chloride, lithium chloride, lithium perchlorate, ammonium chloride, potassium chlorate, aluminum chloride, copper chloride, ferrous chloride, ferric chloride, ammonium sulfate, potassium nitrate, sodium nitrate, sodium carbonate, sodium thiocyanate, etc. These may be used alone or in combination of two or more.

[0078] -Polyhydric alcohol compounds- The polyhydric alcohol compound is not particularly limited, and examples thereof include propanediol, butanediol, hexanediol, polyethylene glycol, trimethylolpropane, pentaerythritol, etc. These may be used alone or in combination of two or more.

[0079] -Ionic liquids- The ionic liquid is not particularly limited, and examples thereof include ionic liquids containing imidazolium ions such as 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1,3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide, and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide; 1-methylpyridinium bis(trifluoromethylsulfonyl)imide, 1-butylpyridinium bis(trifluoromethylsulfonyl)imide, 1-hexylpyridinium bis(trifluoromethylsulfonyl)imide, 1-octylpyridinium bis(trifluoromethylsulfonyl)imide, 1-hexyl-4-methylpyridinium bis(trifluoromethylsulfonyl)imide, 1-hexyl-4-methylpyridinium hexafluorophosphate, and 1-octyl-4-methylpyridinium bis(trifluoromethylsulfonyl)imide. ionic liquids containing pyridinium ions such as 1-octyl-4-methylpyridinium bis(fluorosulfonyl)imide, 1-methylpyridinium bis(perfluoroethylsulfonyl)imide, and 1-methylpyridinium bis(perfluorobutylsulfonyl)imide; ionic liquids containing ammonium ions such as trimethylheptylammonium bis(trifluoromethanesulfonyl)imide, N,N-diethyl-N-methyl-N-propylammonium bis(trifluoromethanesulfonyl)imide, N,N-diethyl-N-methyl-N-pentylammonium bis(trifluoromethanesulfonyl)imide, N,N-diethyl-N-methyl-N-heptylammonium bis(trifluoromethanesulfonyl)imide, and tri-n-butylmethylammonium bistrifluoromethanesulfonimide; other ionic liquids such as pyrrolidinium salts, phosphonium salts, and sulfonium salts; and the like. These may be used alone or in combination of two or more.

[0080] -Surfactants- The surfactant is not particularly limited, and examples thereof include nonionic low-molecular-weight surfactants such as glycerin fatty acid esters, polyoxyalkylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene alkylamines, polyoxyethylene alkylamine fatty acid esters, and fatty acid diethanolamides; anionic low-molecular-weight surfactants such as alkyl sulfonates, alkylbenzene sulfonates, and alkyl phosphates; cationic low-molecular-weight surfactants such as tetraalkylammonium salts and trialkylbenzylammonium salts; amphoteric low-molecular-weight surfactants such as alkyl betaines and alkyl imidazolium betaines; nonionic polymeric surfactants such as polyether ester amides, ethylene oxide-epichlorohydrin types, and polyether ester types; anionic polymeric surfactants such as polystyrene sulfonates; cationic polymeric surfactants such as quaternary ammonium base-containing acrylate polymers; amphoteric polymeric surfactants such as amino acid amphoteric surfactants such as higher alkylaminopropionates, and betaine-type amphoteric surfactants such as higher alkyldimethyl betaines and higher alkyldihydroxyethyl betaines. These may be used alone or in combination of two or more.

[0081] <<Leveling agent>> The leveling agent is not particularly limited, and examples thereof include acrylic leveling agents, fluorine-based leveling agents, silicone-based leveling agents, etc. These may be used alone or in combination of two or more. Among these, acrylic leveling agents are preferred. The amount of the leveling agent to be added is not particularly limited, but is preferably 0.001 to 2 parts by mass, more preferably 0.01 to 1.5 parts by mass, and particularly preferably 0.1 to 1 part by mass, per 100 parts by mass of the oxyalkylene polymer (A) and the hydroxyl group-terminated urethane prepolymer (X) combined.

[0082] <<Other optional ingredients>> The other optional components are not particularly limited and include, for example, resins other than the oxyalkylene polymer (A) and the hydroxyl group-terminated urethane prepolymer (X), fillers (talc, calcium carbonate, titanium oxide, etc.), metal powder, colorants (pigments, etc.), foil-like materials, softeners, conductive agents, silane coupling agents, lubricants, corrosion inhibitors, heat stabilizers, polymerization inhibitors, antifoaming agents, etc. These may be used alone or in combination of two or more.

[0083] <Method of manufacturing pressure-sensitive adhesive composition> A method for producing the pressure-sensitive adhesive composition of the present invention, which contains at least one of the oxyalkylene polymer (A) and the hydroxyl group-terminated urethane prepolymer (X), and the polyisocyanate compound (Y), will be described.

[0084] The pressure-sensitive adhesive composition of the present invention may be a one-component type containing at least one of an oxyalkylene polymer (A) and a hydroxyl-terminated urethane prepolymer (X) and a polyisocyanate compound (Y), or a two-component type in which a first component containing at least one of an oxyalkylene polymer (A) and a hydroxyl-terminated urethane prepolymer (X) is mixed with a second component containing a polyisocyanate compound (Y). By heating a pressure-sensitive adhesive composition containing at least one of an oxyalkylene polymer (A) and a hydroxyl group-terminated urethane prepolymer (X), and a polyisocyanate compound (Y), the formation of urethane bonds proceeds, and a pressure-sensitive adhesive is obtained. The pressure-sensitive adhesive composition of the present invention may further contain a catalyst, a solvent, an optional component that can be blended in the pressure-sensitive adhesive composition, and the like. In the case of a two-component type, the first and second components are contained in separate containers, which can be various types such as tubes and bottles.

[0085] The reaction temperature when curing the pressure-sensitive adhesive composition of the present invention is not particularly limited, and from the viewpoint of easily suppressing side reactions other than the urethanization reaction, it is preferably 30 to 140°C, more preferably 35 to 130°C, and particularly preferably 40 to 120°C.

[0086] (adhesive) The pressure-sensitive adhesive of the present invention is obtained by curing the pressure-sensitive adhesive composition of the present invention. The content of EO units relative to the total amount of oxyalkylene groups in the pressure-sensitive adhesive of the present invention is not particularly limited, but is preferably 0 to 40 mass %, more preferably 0 to 30 mass %, and particularly preferably 0 to 20 mass %. When the EO unit content relative to the total amount of oxyalkylene groups in the pressure-sensitive adhesive of the present invention is equal to or greater than the lower limit, the haze of the pressure-sensitive adhesive is likely to be suppressed and the pot life is likely to be improved.When the EO unit content relative to the total amount of oxyalkylene groups in the pressure-sensitive adhesive of the present invention is equal to or less than the upper limit, the adhesiveness of the pressure-sensitive adhesive to the substrate layer is likely to be further improved. The EO unit content relative to the total amount of oxyalkylene groups in the adhesive is: 13 It was calculated by determining the monomer composition of the oxyalkylene chain using C-NMR. The PO unit content relative to the total amount of oxyalkylene groups in the pressure-sensitive adhesive of the present invention is not particularly limited, but is preferably 60 to 100 mass %, more preferably 70 to 100 mass %, and particularly preferably 80 to 100 mass %. When the PO unit content relative to the total amount of oxyalkylene groups in the pressure-sensitive adhesive of the present invention is within the above range, the adhesive becomes amorphous and is therefore easy to handle, which is preferable from the viewpoint of adhesiveness and water resistance of the resin. The PO unit content relative to the total amount of oxyalkylene groups in the adhesive is 13 It was calculated by determining the monomer composition of the oxyalkylene chain using C-NMR.

[0087] <Adhesive manufacturing method> A method for producing the pressure-sensitive adhesive of the present invention by reacting at least one of the oxyalkylene polymer (A) and the hydroxyl-terminated urethane prepolymer (X) with the polyisocyanate compound (Y) will be described. In the method for producing the pressure-sensitive adhesive, a pressure-sensitive adhesive composition is prepared by mixing at least one of an oxyalkylene polymer (A) and a hydroxyl group-terminated urethane prepolymer (X) with a polyisocyanate compound (Y), and the pressure-sensitive adhesive composition is applied to a substrate layer, and the substrate layer to which the pressure-sensitive adhesive composition has been applied is heated.

[0088] <<Mixture>> Mixing of at least one of the oxyalkylene polymer (A) and the hydroxyl group-terminated urethane prepolymer (X) with the polyisocyanate compound (Y) (preparation of the pressure-sensitive adhesive composition) is usually carried out at 10 to 50°C. The mixing method for mixing at least one of the oxyalkylene polymer (A) and the hydroxyl group-terminated urethane prepolymer (X) with the polyisocyanate compound (Y) is not particularly limited, and examples thereof include conventionally known methods such as dispersion mixing using a roll mill, stirring and mixing using a rotor blade, mixing using a planetary stirring mixer, mixing using a homogenizer, and mixing using a kneader.

[0089] <<Coating>> The coating method for coating the pressure-sensitive adhesive composition onto the substrate layer is not particularly limited, and examples thereof include conventionally known methods such as spray coating, bar coating, knife coating, roll coating, blade coating, and die coating.

[0090] <<Heating>> The substrate layer coated with the pressure-sensitive adhesive composition is usually heated at 30 to 140°C.

[0091] (adhesive material) The adhesive material of the present invention has a base layer and a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive of the present invention, which is provided on at least one surface of the base layer. The adhesive patch of the present invention preferably has a pressure-sensitive adhesive layer provided on one side of a base film (base layer), and a release liner or carrier film releasably laminated to cover the adhesive surface of the pressure-sensitive adhesive layer. The adhesive patch of the present invention is produced, for example, by applying the pressure-sensitive adhesive composition of the present invention onto a carrier film using a coating applicator, drying the applied pressure-sensitive adhesive composition to form a pressure-sensitive adhesive layer, laminating a base film on the surface of the formed pressure-sensitive adhesive layer opposite the carrier film, and curing the resulting layer. Here, in the above-mentioned method for producing an adhesive patch, instead of forming a pressure-sensitive adhesive layer (resin layer) on a carrier film and laminating a base film on the surface of the formed pressure-sensitive adhesive layer (resin layer) opposite the carrier film, a pressure-sensitive adhesive layer (resin layer) may be formed on a base film and a carrier film may be laminated on the surface of the formed pressure-sensitive adhesive layer (resin layer) opposite the base film.

[0092] The thickness of the base film is not particularly limited, but from the viewpoint of reducing the possibility of the patch breaking, it is preferably 5 to 200 μm, more preferably 10 to 100 μm, and particularly preferably 20 to 50 μm.

[0093] The material for the substrate film is not particularly limited, and examples thereof include urethane-based polymers such as polyether urethane and polyester urethane; amide-based polymers such as polyether polyamide block polymers; acrylic polymers such as polyacrylate; olefin-based polymers such as polyethylene, polypropylene, and ethylene / vinyl acetate copolymer; ester-based polymers such as polyether polyester; etc. These may be used alone or in combination of two or more. Among these, ester polymers are preferred. Furthermore, a laminated film in which base films made of different materials are laminated may be used. The base film may be laminated with fabric such as woven fabric, nonwoven fabric, knitted fabric, or net.

[0094] The thickness of the adhesive layer is not particularly limited, but from the viewpoint of obtaining better adhesiveness, it is preferably 5 to 100 μm, more preferably 10 to 50 μm, and particularly preferably 20 to 30 μm.

[0095] In order to prevent contamination of the surface of the adhesive layer of the adhesive material of the present invention, it is preferable that the surface of the adhesive layer is covered with a release liner or a carrier film until use. The release liner is not particularly limited, and examples thereof include those in which the surface of high-quality paper, glassine paper, parchment paper, etc. is coated with a release agent having release properties such as silicone resin or fluororesin; or those in which the surface of high-quality paper anchor-coated with resin or high-quality paper laminated with polyethylene is coated with a release agent having release properties such as silicone resin or fluororesin; etc. These may be used alone or in combination of two or more.

[0096] The material of the support film is not particularly limited, and examples thereof include plastic films such as polyester films, etc. These may be used alone or in combination of two or more. A carrier film can be releasably laminated on the surface of the base film opposite to the surface on which the pressure-sensitive adhesive layer is formed. The carrier film can be peelably laminated to the back surface of the substrate film by a method such as inflation molding, extrusion lamination, lamination molding, or casting. The thickness of the support film varies depending on the material and is not particularly limited, but is preferably 15 to 200 μm, more preferably 20 to 100 μm, and particularly preferably 30 to 50 μm.

[0097] (Surface protection film) The surface protection film of the present invention has a substrate layer and a pressure-sensitive adhesive layer provided on at least one surface of the substrate layer and containing the pressure-sensitive adhesive of the present invention. FIG. 1 is a schematic cross-sectional view of a surface protection film of the present invention. In FIG. 1, a surface protection film 100 includes a base layer 10 and a pressure-sensitive adhesive layer 20, and may further include any other appropriate layers (not shown) as necessary.

[0098] For the surface of the base layer 10 on which the adhesive layer 20 is not applied, a release treatment can be performed by adding, for example, fatty acid amide, polyethyleneimine, long-chain alkyl additives, etc. to the base layer 10, or a coating layer made of any suitable release agent such as a silicone-based, long-chain alkyl-based, or fluorine-based release agent can be provided, in order to form a roll that is easy to unwind. The surface protection film 100 may have a release liner attached thereto that has releasability.

[0099] The thickness of the surface protection film is not particularly limited and can be set to any appropriate thickness depending on the application, but from the viewpoint of fully exhibiting the effects of the present invention, it is preferably 10 to 400 μm, more preferably 15 to 300 μm, even more preferably 20 to 250 μm, and particularly preferably 25 to 150 μm.

[0100] <Base material layer> The thickness of the base layer is not particularly limited, but is preferably 5 to 300 μm, more preferably 10 to 250 μm, still more preferably 15 to 200 μm, and particularly preferably 20 to 150 μm.

[0101] The substrate layer may be a single layer or a laminate of two or more layers. The substrate layer may be stretched.

[0102] The material for the substrate layer is not particularly limited and examples thereof include plastic, paper, metal film, nonwoven fabric, etc. These may be used alone or in combination of two or more. Of these, plastic is preferred.

[0103] The plastic is not particularly limited, and examples thereof include polyester resins, polyamide resins, polyolefin resins, etc. These may be used alone or in combination of two or more. The polyester resin is not particularly limited, and examples thereof include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc. These may be used alone or in combination of two or more. The polyamide resin is not particularly limited, and examples thereof include aromatic polyamides such as polyamide 6T, polyamide 6I, and polymetaxylene terephthalamide, which are made from an aliphatic amine and an aromatic carboxylic acid such as terephthalic acid or isophthalic acid, and aliphatic polyamides such as polyamide 6 and polyamide 66, which are made from an aliphatic amine and an aliphatic carboxylic acid. These may be used alone or in combination of two or more. The polyolefin resin is not particularly limited, and examples thereof include homopolypropylene; propylene copolymers such as block copolymers, random copolymers, and graft copolymers having ethylene as a copolymerization component; reactor TPO; ethylene polymers such as low-density, high-density, linear low-density, and ultra-low-density copolymers; 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; etc. These may be used alone or in combination of two or more.

[0104] The substrate layer may contain any additives as needed. The additives that can be contained in the base layer are not particularly limited and include, for example, antioxidants, ultraviolet absorbers, light stabilizers, fillers, antistatic agents, pigments, etc. These may be used alone or in combination of two or more. Among these, antioxidants, ultraviolet absorbers, light stabilizers, and fillers are preferred from the viewpoint of improving weather resistance, and antistatic agents are preferred from the viewpoint of imparting antistatic properties.

[0105] The antioxidant is not particularly limited, and examples thereof include phenol-based antioxidants, phosphorus-based processing heat stabilizers, lactone-based processing heat stabilizers, sulfur-based heat stabilizers, phenol-phosphorus-based antioxidants, etc. These may be used alone or in combination of two or more. The content ratio of the antioxidant is not particularly limited, but is preferably 1 part by mass or less, more preferably 0.5 parts by mass or less, and particularly preferably 0.01 to 0.2 parts by mass, relative to 100 parts by mass of the base resin of the substrate layer (if the substrate layer is a mixture, the mixture is the base resin).

[0106] The ultraviolet absorber is not particularly limited, and examples thereof include benzotriazole-based ultraviolet absorbers, triazine-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, etc. These may be used alone or in combination of two or more. The content of the ultraviolet absorber is not particularly limited, but is preferably 2 parts by mass or less, more preferably 1 part by mass or less, and particularly preferably 0.01 to 0.5 parts by mass, relative to 100 parts by mass of the base resin of the substrate layer (if the substrate layer is a mixture, the mixture is the base resin).

[0107] The light stabilizer is not particularly limited, and examples thereof include hindered amine light stabilizers, benzoate light stabilizers, etc. These may be used alone or in combination of two or more. The content ratio of the light stabilizer is not particularly limited, but is preferably 2 parts by mass or less, more preferably 1 part by mass or less, and particularly preferably 0.01 to 0.5 parts by mass per 100 parts by mass of the base resin of the substrate layer (if the substrate layer is a mixture, the mixture is the base resin).

[0108] The filler is not particularly limited, and examples thereof include inorganic fillers such as carbon black, titanium oxide, zinc oxide, etc. These may be used alone or in combination of two or more. The filler content is not particularly limited, but is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and particularly preferably 0.01 to 10 parts by mass, relative to 100 parts by mass of the base resin of the substrate layer (if the substrate layer is a mixture, the mixture is the base resin).

[0109] The antistatic agent is not particularly limited, and examples thereof include inorganic, low-molecular-weight, and high-molecular-weight antistatic agents such as surfactants, inorganic salts, polyhydric alcohols, metal compounds, and carbon. These may be used alone or in combination of two or more. Among these, from the viewpoint of preventing contamination and maintaining adhesiveness, high molecular weight antistatic agents and carbon are preferred.

[0110] <Adhesive layer> The thickness of the pressure-sensitive adhesive layer is not particularly limited, but is preferably 1 to 100 μm, more preferably 3 to 50 μm, and particularly preferably 5 to 30 μm.

[0111] The pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition containing a urethane resin. The content of the urethane resin in the pressure-sensitive adhesive layer is not particularly limited, and is preferably 90 to 100% by mass, more preferably 95 to 100% by mass, and particularly preferably 98 to 100% by mass. Only one type of pressure-sensitive adhesive may be used, or two or more types may be used.

[0112] The pressure-sensitive adhesive layer may contain other components in addition to the urethane resin, as long as the effects of the present invention are not impaired. The other components are not particularly limited, and examples thereof include resin components other than urethane-based resins, tackifiers, inorganic fillers, organic fillers, metal powders, pigments, foil-like materials, softeners, plasticizers, antioxidants, conductive agents, UV absorbers, antioxidants, light stabilizers, surface lubricants, leveling agents, corrosion inhibitors, heat stabilizers, polymerization inhibitors, lubricants, and solvents.

[0113] Examples of methods for producing the pressure-sensitive adhesive layer include a method in which a composition that is a material for forming the pressure-sensitive adhesive layer is applied onto a substrate layer to form the pressure-sensitive adhesive layer on the substrate layer. Examples of such coating methods include roll coating, gravure coating, reverse coating, roll brushing, spray coating, air knife coating, and extrusion coating using a die coater.

[0114] The surface protective film of the present invention is preferably used for protecting the surface of an optical member or an electronic member.

[0115] <Method of manufacturing surface protection film> The surface protective film of the present invention can be produced by any appropriate method. Examples of such a production method include (1) A method of applying a solution or a hot melt of a material for forming the adhesive layer (an adhesive composition containing a urethane resin) onto a substrate layer; (2) A method in which a pressure-sensitive adhesive layer formed by coating a separator is transferred onto a substrate layer in accordance with the method. (3) A method of forming and applying a material for forming a pressure-sensitive adhesive layer onto a substrate layer by extrusion; (4) A method of extruding a substrate layer and a pressure-sensitive adhesive layer in two or more layers. (5) A method of laminating a single layer of an adhesive layer onto a substrate layer, or a method of laminating a double layer of an adhesive layer together with a laminate layer, (6) A method of laminating a pressure-sensitive adhesive layer with a base layer-forming material such as a film or laminate layer in two or more layers. The above-mentioned manufacturing method can be carried out in accordance with any suitable manufacturing method.

[0116] (Optical components) The optical member of the present invention has the surface protective film of the present invention. An optical member to which the surface protective film of the present invention is attached can be manually attached and peeled off many times. The optical member is not particularly limited, and examples thereof include display devices such as smartphones, tablets, and smartwatches, optical devices such as lenses, etc. These may be used alone or in combination of two or more.

[0117] (Electronic materials) The electronic member of the present invention has the surface protection film of the present invention. Electronic components to which the surface protection film of the present invention is attached can be manually attached and peeled off many times. The electronic components are not particularly limited, and examples thereof include various flexible printed circuit boards, electronic circuits, etc. These may be used alone or in combination of two or more. [Example]

[0118] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Examples 1 to 7 are working examples, and Examples 8 and 9 are comparative examples.

[0119] <Methods for measuring physical properties> [Hydroxyl value] The hydroxyl value of the oxyalkylene polymer was calculated using a phthalating reagent in accordance with Method B of JIS K 1557-1:2007. The results are shown in Table 1.

[0120] [Hydroxyl value converted molecular weight] The hydroxyl value-based molecular weight of the oxyalkylene polymer is a value calculated from the formula 56100 / (hydroxyl value) x (number of hydroxyl groups per molecule). The "number of hydroxyl groups per molecule" refers to the number of hydroxyl groups or the average number of hydroxyl groups in the oxyalkylene polymer. The results are shown in Table 1.

[0121] [Mn, Mw, Mw / Mn] The number average molecular weight Mn, weight average molecular weight Mw and molecular weight distribution Mw / Mn of the oxyalkylene polymer and the hydroxyl group-terminated urethane prepolymer are values ​​obtained by measurement according to the methods described below. Several types of monodisperse polystyrenes with different degrees of polymerization were used as standard samples for molecular weight measurement, and measurements were performed using a commercially available GPC analyzer (HLC-8420GPC, manufactured by Tosoh Corporation). A calibration curve was created based on the relationship between the molecular weight of the polystyrene and retention time. The oxyalkylene polymer sample was diluted to 0.5% by mass with tetrahydrofuran and passed through a filter with a pore size of 0.5 μm. The sample was then measured using the GPC analyzer. Using the calibration curve, the GPC spectrum of the sample was analyzed by computer to determine the Mn and Mw of the sample. Mw / Mn was calculated from the Mw and Mn. The results are shown in Table 1.

[0122] [Oxyethylene group content (ethylene oxide unit (EO unit) content)] The content ratio of oxyethylene groups (EO unit content) to the total amount of oxyalkylene groups in the oxyalkylene polymer, hydroxyl group-terminated urethane prepolymer, and cured product (adhesive) is: 1 The values ​​were calculated by determining the monomer composition of the oxyalkylene chain using H-NMR. The results are shown in Table 1. For example, when the oxyalkylene polymer is a polyol composed of PO units and EO units, the EO unit content can be determined from the area ratio of the signal of the methyl group in the PO unit to the signal of the methylene group in the PO unit and the EO unit.

[0123] [Unsaturation degree] The degree of unsaturation of the oxyalkylene polymer was measured according to the method of JIS K 1557-3: 2007. The results are shown in Table 1.

[0124] [Adhesion strength evaluation] The pressure-sensitive adhesive compositions described in Examples 1 to 9 were applied to a 25 μm thick PET film using an applicator to a thickness of 10 μm, and the film was left to dry and harden in a thermostatic chamber at 130°C. The film was then cut into a width of 25 mm and a length of 150 mm to prepare a sample for evaluation. The adhesive layer of the test sample was bonded to a glass plate (float glass) at 23°C and 50% RH. The test sample was placed horizontally with the substrate film side facing up, and a 2.0 kg roller was rolled back and forth from the substrate film side to press the adhesive layer to the glass plate. After 30 minutes of curing at 23°C and 50% RH, the adhesive layer was peeled from the glass plate interface using a universal tensile tester (A&D Co., Ltd., product name: Tensilon RTG-1310) at a peel angle of 180° and a pulling rate of 300 mm / min to measure the adhesive strength of the adhesive layer. The adhesive strengths, as determined below, are shown in Table 2. A: When the adhesive strength is 0.10N / 25mm or less B: When the adhesive strength exceeds 0.10N / 25mm

[0125] [Evaluation of Coatability] The pressure-sensitive adhesive compositions described in Examples 1 to 9 were applied to a 25 μm thick PET film using an applicator to a thickness of 10 μm. In Examples 1 to 9, the pressure-sensitive adhesive (layer) formed on the PET film was visually observed to check for the presence or absence of foreign matter and repelling. In Examples 1 to 9, the adhesive composition was evaluated as A (smooth) when it could be applied smoothly and neatly to the PET film without any foreign matter or cissing, and as B (uneven) when it could not be applied neatly due to the occurrence of foreign matter or cissing. The evaluation results are shown in Table 2.

[0126] [Evaluation of curability] The pressure-sensitive adhesive compositions described in Examples 1 to 9 were applied to a 25 μm thick PET film using an applicator to a thickness of 10 μm, and then left to dry and cure in a thermostatic chamber at 130° C. In Examples 1 to 9, those that had lost their tackiness after one day were rated as A, and those that were very sticky were rated as B. The evaluation results are shown in Table 2.

[0127] <Synthesis of oxyalkylene polymer> <Synthesis Example 1: Oxyalkylene polymer (a-1)> Sorbitol (6 hydroxyl groups) was subjected to ring-opening polymerization with propylene oxide in the presence of an alkali metal catalyst (KOH catalyst), and the neutralized salt was removed to obtain a polyether polyol (hydroxyl value-based molecular weight: 880). Using 880 g of the resulting polyether polyol as intermediate polyol A, 41,120 g of propylene oxide was polymerized in the presence of a zinc hexacyanocobaltate complex (hereinafter also referred to as "TBA-DMC catalyst") slurry whose ligand is t-butanol, to obtain an oxyalkylene polymer (a-1). The amount of TBA-DMC catalyst slurry was adjusted so that the metal concentration of the TBA-DMC catalyst in the reaction solution was 100 ppm by mass. The number of hydroxyl groups, hydroxyl value, hydroxyl group-equivalent molecular weight, Mn, Mw / Mn, EO unit content, and degree of unsaturation of the obtained oxyalkylene polymer (a-1) are shown in Table 1. These values ​​were measured by the above-mentioned methods. The same is true for the oxyalkylene polymers (a-2), (a-3), (a-4), (b-1), (b-2), (b-3), and (b-4) obtained in the following Synthesis Examples 2 to 8. In addition, the "number of hydroxyl groups" in Table 1 is the number of hydroxyl groups of the initiator used during synthesis (sorbitol has 6 hydroxyl groups, pentaerythritol has 4 hydroxyl groups, glycerin has 3 hydroxyl groups, and propylene glycol has 2 hydroxyl groups), and these values ​​are the number of hydroxyl groups of each oxyalkylene polymer.

[0128] <Synthesis Example 2: Oxyalkylene polymer (a-2)> An oxyalkylene polymer (a-2) was obtained in the same manner as in Synthesis Example 1, except that 6,620 g of propylene oxide was used instead of 41,120 g of propylene oxide.

[0129] <Synthesis Example 3: Oxyalkylene polymer (a-3)> Sorbitol (6 hydroxyl groups) was used as an initiator and 8,168 g of propylene oxide was polymerized in the presence of an alkali metal catalyst (KOH catalyst), followed by further polymerization of 1,250 g of ethylene oxide. The neutralized salt was removed to obtain an oxyalkylene polymer (a-3) having EO units in a block form.

[0130] <Synthesis Example 4: Oxyalkylene polymer (a-4)> Pentaerythritol (number of hydroxyl groups: 4) was used as an initiator and 6,820 g of propylene oxide was polymerized in the presence of an alkali metal catalyst (KOH catalyst), and then 1,040 g of ethylene oxide was further polymerized, and the neutralized salt was removed to obtain an oxyalkylene polymer (a-4) having EO units in a block form.

[0131] <Synthesis Example 5: Oxyalkylene polymer (b-1)> Glycerin (3 hydroxyl groups) was subjected to ring-opening polymerization of propylene oxide in the presence of an alkali metal catalyst (KOH catalyst), and the neutralized salt was removed to obtain a polyether polyol (1,000 molecular weight calculated as hydroxyl value). 1,000 g of the obtained polyether polyol was used as intermediate polyol A, and 9,000 g of propylene oxide was polymerized in the presence of a TBA-DMC catalyst slurry to obtain an oxyalkylene polymer (b-1). The amount of TBA-DMC catalyst slurry was adjusted so that the metal concentration of the TBA-DMC catalyst in the reaction solution was 50 ppm by mass.

[0132] <Synthesis Example 6: Oxyalkylene polymer (b-2)> Propylene glycol (2 hydroxyl groups) was subjected to ring-opening polymerization with propylene oxide in the presence of an alkali metal catalyst (KOH catalyst), and the neutralized salt was removed to obtain a polyether polyol (1,000 molecular weight calculated as hydroxyl value). 1,000 g of the obtained polyether polyol was used as intermediate polyol A, and 9,000 g of propylene oxide was polymerized in the presence of a TBA-DMC catalyst slurry to obtain an oxyalkylene polymer (b-2). The amount of TBA-DMC catalyst slurry was adjusted so that the metal concentration of the TBA-DMC catalyst in the reaction solution was 50 ppm by mass.

[0133] <Synthesis Example 7: Oxyalkylene polymer (b-3)> Glycerin (3 hydroxyl groups) as an initiator was polymerized with 2,900 g of propylene oxide in the presence of an alkali metal catalyst (KOH catalyst), and the neutralized salt was removed to obtain an oxyalkylene polymer (b-3).

[0134] <Synthesis Example 8: Oxyalkylene polymer (b-4)> Glycerin (3 hydroxyl groups) as an initiator was polymerized with 900 g of propylene oxide in the presence of an alkali metal catalyst (KOH catalyst), and the neutralized salt was removed to obtain an oxyalkylene polymer (b-4).

[0135] [Table 1]

[0136] <Example 1> A pressure-sensitive adhesive composition was obtained by uniformly mixing 100 parts by mass of the first oxyalkylene polymer (a-1), 7.0 parts by mass of a polyisocyanate compound (Y) (Coronate HX, manufactured by Tosoh Corporation, isocyanate group content 21.3% by mass) as a curing agent, 0.04 parts by mass of Narcem ferric iron manufactured by Nippon Chemical Industry Co., Ltd. as a catalyst, and ethyl acetate as a solvent to give a total solids concentration of 50% by mass.

[0137] <Examples 2-9> A pressure-sensitive adhesive composition was obtained in the same manner as in Example 1, using the blending amounts (parts by mass) shown in Table 2. Table 2 shows the properties of the oxyalkylene polymer and the evaluation results of the resulting pressure-sensitive adhesive. In Table 2, "-" indicates that the component was not included.

[0138] [Table 2]

[0139] As shown in Table 2, in Examples 1 to 7, pressure-sensitive adhesive compositions excellent in coatability and curability were obtained. [Industrial Applicability]

[0140] The pressure-sensitive adhesive obtained by the present invention is suitably used as a pressure-sensitive adhesive for surface protection films that protect the surfaces of flat panel displays (liquid crystal displays, organic electroluminescence displays, etc.) and touch panel displays that are widely used in electronic devices such as televisions, personal computers (PCs), mobile phones, and mobile terminals, as well as substrates (glass substrates, ITO / glass substrates in which an ITO (indium tin oxide) film is formed on a glass substrate, etc.) and optical components produced or used in the production process of these displays. The surface protection film of the present invention can be used for applications such as protecting the surface by adhering it to the surface of an optical member or an electronic member. [Explanation of symbols]

[0141] 10 Base material layer 20 adhesive layer 100 Surface Protection Film

Claims

1. The present invention includes a urethane resin having a structural unit derived from an oxyalkylene polymer and a structural unit derived from a polyisocyanate compound, The pressure-sensitive adhesive composition includes a first oxyalkylene polymer having 4 to 20 hydroxyl groups per molecule and a number average molecular weight of 2,000 to 100,000.

2. The pressure-sensitive adhesive composition according to claim 1, wherein the first oxyalkylene polymer has a number average molecular weight of 3,000 to 100,000.

3. 2. The pressure-sensitive adhesive composition according to claim 1, wherein the first oxyalkylene polymer has 4 to 8 hydroxyl groups per molecule.

4. The pressure-sensitive adhesive composition according to claim 1, wherein the oxyalkylene polymer further comprises a second oxyalkylene polymer having 1 to 3 hydroxyl groups per molecule and a number average molecular weight of 500 to 100,000.

5. The urethane resin is at least one of the oxyalkylene polymer and a hydroxyl group-terminated prepolymer obtained by subjecting the oxyalkylene polymer and a diisocyanate compound to a urethanization reaction, The polyisocyanate compound; The pressure-sensitive adhesive composition according to claim 1 , obtained by reacting

6. A pressure-sensitive adhesive which is a cured product of the pressure-sensitive adhesive composition according to any one of claims 1 to 5.

7. A patch comprising a base layer and a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive according to claim 6 provided on at least one surface of the base layer.

8. A surface protection film comprising a substrate layer and a pressure-sensitive adhesive layer provided on at least one surface of the substrate layer, the pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive according to claim 6.

9. An optical member comprising the surface protective film according to claim 8 .

10. An electronic component comprising the surface protection film according to claim 8 .

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