Curable composition for preventing sulfurization, adhesive sheet and coating film, and member for display device

Abstract

Provided are a curable composition for preventing sulfurization that can inhibit sulfurization, and an adhesive sheet and a coating film obtained from said composition.　The present invention is a curable composition used for preventing sulfurization of a metal, wherein: the composition contains a main agent and a phosphorous acid ester compound; the main agent is at least one selected from the group consisting of acrylic polymers and polymerizable monomers; the number of phenyl moieties bonded to phosphorous acid moieties in the phosphorous acid ester compound is two or fewer; and expression (1) A×B≥0.5 is satisfied, where the content of the phosphorous acid ester compound relative to 100 parts by mass of the main agent is A parts by mass, and the number of phosphorous acid moieties within the phosphorous acid compound is B.

Description

Curable composition for preventing sulfurization, adhesive sheet and film, and display device component

[0001] The present invention relates to a curable composition for preventing sulfidation, a pressure-sensitive adhesive sheet and film, and a member for a display device.

[0002] In recent years, touch sensor films, which have metal mesh pattern wiring made of silver or copper formed on a resin film, have been used in touch panels of mobile terminals, etc. Such touch sensor films are highly flexible and tend to improve touch sensitivity.

[0003] A touch sensor film can be manufactured, for example, by bonding it to another component (e.g., glass, a polarizing plate, etc.) using an adhesive sheet, and various adhesive sheets to be used for this purpose have been studied (see, for example, Patent Document 1, etc.).

[0004] Japanese Patent Application Laid-Open No. 2017-160416

[0005] However, metal mesh pattern wiring made of silver or copper, such as in touch sensor films, can undergo sulfurization, which can reduce the sensitivity of the touch sensor and cause malfunctions. The sulfurization can be caused by, for example, the environment in which a device equipped with the touch sensor film is used (e.g., a hot spring), or by sulfur components generated from rubber or other components installed inside the device. Therefore, there has been a need to prevent sulfurization of metal mesh pattern wiring installed in touch sensor films and the like.

[0006] The present invention has been made in view of the above, and has an object to provide a sulfuration-preventing curable composition that can suppress sulfuration, as well as a pressure-sensitive adhesive sheet and film obtained from the composition.

[0007] As a result of extensive research conducted by the present inventors in order to achieve the above object, they discovered that a composition containing a specific phosphite ester compound in a predetermined amount can prevent sulfurization of metals, and thus completed the present invention.

[0008] That is, the present invention encompasses, for example, the following subjects. Item 1: A curable composition used to prevent metal sulfidation, comprising a base agent and a phosphite ester compound, wherein the base agent is at least one selected from the group consisting of acrylic polymers and polymerizable monomers, and the phosphite ester compound has two or less phenyl moieties bonded to phosphite moieties, and the sulfidation-preventing curable composition satisfies the following formula (1): A×B≧0.5 (1), where A parts by mass of the phosphite ester compound is contained per 100 parts by mass of the base agent, and B is the number of phosphite moieties in the phosphite ester compound. Item 2: The sulfidation-preventing curable composition according to Item 1, wherein the metal is silver or copper and the composition is a metal layer having a mesh structure. Item 3: A pressure-sensitive adhesive sheet comprising a cured product of the sulfidation-preventing curable composition according to Item 1 or 2. Item 4: A coating comprising a cured product of the sulfidation-preventing curable composition according to Item 1 or 2. Item 5. A component for a display device comprising a touch sensor film, wherein the touch sensor film comprises a laminate including the pressure-sensitive adhesive sheet according to Item 3 and a metal layer having a mesh structure, wherein the pressure-sensitive adhesive sheet is attached to at least one surface of the metal layer, and the metal layer is silver or copper. Item 6. A component for a display device comprising a touch sensor film, wherein the touch sensor film comprises a laminate including the coating according to Item 4 and a metal layer having a mesh structure, wherein the coating is formed on at least one surface of the metal layer, and the metal layer is silver or copper. Item 7. A display device comprising the component for a display device according to claim 5. Item 8. A display device comprising the component for a display device according to Item 6.

[0009] The sulfuration-preventing curable composition of the present invention can form a pressure-sensitive adhesive sheet or film that can inhibit the sulfuration of metals. When the pressure-sensitive adhesive sheet or film obtained from the sulfuration-preventing curable composition of the present invention is provided on a metal layer, it can inhibit the sulfuration of the metal layer.

[0010]

[0023] In the present specification, the terms "contain" and "comprise" include the concepts of "contain," "comprise," "consist essentially of," and "consist only of."

[0011] 1. Curable Composition for Sulfuration Prevention The curable composition for sulfuration prevention of the present invention is used to prevent the sulfurization of metals, and contains a base agent and a phosphite ester compound, wherein the base agent is at least one selected from the group consisting of acrylic polymers and polymerizable monomers, and the phosphite ester compound has two or less phenyl moieties bonded to phosphite moieties, and when the content of the phosphite ester compound per 100 parts by mass of the base agent is A parts by mass and the number of phosphite moieties in the phosphite ester compound is B, the following formula (1) is satisfied: A×B≧0.5 (1)

[0012] The sulfuration-preventing curable composition of the present invention can form a pressure-sensitive adhesive sheet or film that can suppress the sulfuration of metals. Specifically, a pressure-sensitive adhesive sheet or film obtained using the sulfuration-preventing curable composition of the present invention is suitable for, for example, a touch sensor film having a metal layer with a mesh structure. By laminating a pressure-sensitive adhesive sheet to the metal layer or by forming a film on the metal layer, sulfuration of the metal layer can be suppressed. Furthermore, the pressure-sensitive adhesive sheet or film can reduce the resistance change rate of the metal layer even in a high-humidity environment. For this reason, the sulfuration-preventing curable composition of the present invention is particularly suitable for display device components that include a touch sensor film.

[0013] (Phosphite Compound) The sulfuration-preventing curable composition of the present invention contains a phosphite compound as an essential component.

[0014] Phosphite compounds are PO 3 compounds in which three oxygen atoms are bonded to a phosphorus atom. ３ Generally, the phosphorus atom and the oxygen atom are bonded together by a single bond. ３ The bond is referred to as the "phosphorous site."

[0015] The phosphite ester compound may be a compound having one or more of the above-mentioned phosphite moieties in the molecule, and preferably has one or two of the above-mentioned phosphite moieties in the molecule.

[0016] In the phosphite ester compound, the number of phenyl moieties bonded to the phosphite moiety is two or less. "The number of phenyl moieties bonded to the phosphite moiety is two or less" specifically means that the number of phenyl moieties bonded to each phosphite moiety contained in the phosphite ester compound is two or less. Therefore, for example, if a phosphite ester compound has two phosphite moieties and each phosphite moiety is two phenyl moieties, the two phosphite moieties in the phosphite ester compound will have a total of four phenyl moieties.

[0017] Here, the phenyl moiety refers to a phenyl group having no substituent or a phenyl group having a substituent. ６ H ５ It is expressed as -.

[0018] When the phenyl moiety is a phenyl group having a substituent, the substituent can be, for example, an aralkyl group described below. The substituent is preferably an organic group selected from the group consisting of an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, and a cycloalkadienyl group, and more preferably an alkyl group.

[0019] The organic group has, for example, 1 to 30 carbon atoms, preferably 20 or less, more preferably 15 or less, even more preferably 10 or less, particularly preferably 6 or less, and may also have 4 or less. Any organic group selected from the group consisting of an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, and a cycloalkadienyl group may be linear or branched.

[0020] When the phenyl group has a substituent, the number of the substituents may be 1, 2, or 3. Preferably, the number of the substituents is 1.

[0021] As described above, in the phosphite ester compound, the number of phenyl moieties bonded to the phosphite moiety is two or less. The number of phenyl moieties bonded to the phosphite moiety may be zero. That is, no phenyl moiety may be bonded to the phosphite moiety. Furthermore, the phosphite ester compound may have a phenyl moiety at a site other than the phosphite moiety, or may not have a phenyl moiety at a site other than the phosphite moiety.

[0022] The phenyl moiety is preferably directly bonded to the phosphite moiety, i.e., a carbon atom in an unsubstituted phenyl group or a substituted phenyl group is preferably directly bonded to an oxygen atom of the phosphite moiety.

[0023] Specific examples of phosphite ester compounds having one phosphite moiety include compounds represented by the following general formula (1a):

[0024]

[0025] In formula (1a), R １ , R ２ , and R ３ are the same or different and represent a hydrocarbon group. In formula (1a), the moiety consisting of one P atom and three O atoms is a "phosphorous acid moiety."

[0026] The "hydrocarbon group" in formula (1a) can include alkyl groups, alkenyl groups, alkynyl groups, cycloalkyl groups, cycloalkenyl groups, cycloalkadienyl groups, aryl groups, aralkyl groups, and groups that are combinations thereof.

[0027] In formula (1a), when the hydrocarbon group is an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, or a cycloalkadienyl group, the number of carbon atoms therein is, for example, 1 to 30, preferably 20 or less, more preferably 15 or less, also preferably 2 or more, more preferably 4 or more, even more preferably 6 or more, and particularly preferably 8 or more.

[0028] In the formula (1a), when the hydrocarbon group is an aryl group, the number of carbon atoms is 6, that is, a phenyl group. In the formula (1a), when the hydrocarbon group is an aralkyl group, the number of carbon atoms is 6 or more, and in particular, a phenyl group (C ６ H ５ The substituent can be the above-mentioned organic group, and can be selected from the group consisting of alkyl groups, alkenyl groups, alkynyl groups, cycloalkyl groups, cycloalkenyl groups and cycloalkadienyl groups, and is preferably an alkyl group. Examples of the alkyl group include C ８ H １７ -, C １０ H ２１ -, C １２ H ２５ -, C １３ H ２７ --etc.

[0029] R １ , R ２ , and R ３ When at least two of R are aryl groups or aralkyl groups, R １ , R ２ , and R ３ The remaining one of the groups is other than an aryl group or an aralkyl group, that is, an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group or a cycloalkadienyl group, and is preferably an alkyl group.

[0030] Specific examples of phosphite ester compounds having two phosphite moieties include compounds represented by the following general formula (1b).

[0031]

[0032] In formula (1b), R ４ , and R ５ are the same or different and each represents a hydrocarbon group. ４ , and R ５ is R in formula (1a) １ , R ２ , and R ３ In formula (1b), the moiety consisting of one P atom and three O atoms is the "phosphite moiety." Therefore, the phosphite ester compound represented by formula (1b) has two phosphite moieties.

[0033] In formula (1b), R ４ , and R ５ are the same or different, and C ８ H １７ -, C １０ H ２１ -, C １２ H ２５ -, C １３ H ２７ -, C ６ H ５ --etc.

[0034] Another specific example of the phosphite ester compound having two phosphite moieties is a compound represented by the following general formula (1c).

[0035]

[0036] In formula (1c), R ６ , and R ７ are the same or different and each represents an alkylene group; R ８ , R ９ , R １０ , and R １１ are the same or different and each represents a hydrocarbon group. ８ , R ９ , R １０ , and R １１ is R in formula (1a) １ , R ２ , and R ３In formula (1c), the moiety consisting of one P atom and three O atoms is the "phosphite moiety." Therefore, the phosphite ester compound represented by formula (1b) has two phosphite moieties.

[0037] In formula (1c), R ６ , and R ７ In the formula (I), the alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, further preferably 1 to 6 carbon atoms, and particularly preferably 1 to 4 carbon atoms. The alkylene group may be linear or branched. Examples of the alkylene group include -CH ２ CH (CH ３ )- are listed.

[0038] In formula (1c), R ８ , R ９ , R １０ , and R １１ are the same or different, and C ８ H １７ -, C １０ H ２１ -, C １２ H ２５ -, C １３ H ２７ -, C ６ H ５ -, etc., all of which are C ６ H ５ It is preferable that −.

[0039] Further specific examples of the phosphite ester compound include tris(2-ethylhexyl)phosphite, tetraphenyldipropylene glycol diphosphite, diphenylmono(2-ethylhexyl)phosphite, bis(decyl)pentaerythritol diphosphite, and bis(tridecyl)pentaerythritol diphosphite.

[0040] When the acrylic polymer described below has a 2-ethylhexyl group, it is preferred that the phosphite compound also has a 2-ethylhexyl group.

[0041] The sulfuration-preventing curable composition of the present invention may contain only one type of phosphite ester compound, or may contain two or more types of phosphite ester compounds.

[0042] (Base Agent) The base agent contained in the curable composition for preventing sulfurization of the present invention is the main component of the composition and is at least one selected from the group consisting of an acrylic polymer and a polymerizable monomer. Therefore, the base agent may be formed of only an acrylic polymer without containing a polymerizable monomer, a polymerizable monomer without containing an acrylic polymer, or a polymerizable monomer.

[0043] The acrylic polymer may be, for example, a wide variety of known acrylic polymers used to form pressure-sensitive adhesive sheets. For example, the acrylic polymer may be a polymer containing at least a (meth)acrylic acid ester unit. That is, the acrylic polymer is a polymer of a monomer containing a (meth)acrylic acid ester.

[0044] Examples of the (meth)acrylic acid ester include (meth)acrylates having a linear or branched alkyl group.

[0045] In this specification, "(meth)acrylic" means "acrylic" or "methacrylic." For example, "(meth)acrylate" means "acrylate" or "methacrylate."

[0046] Examples of (meth)acrylic acid esters include alkyl (meth)acrylates having a linear, cyclic, or branched alkyl group having 10 to 18 carbon atoms. The linear, cyclic, or branched alkyl group having 10 to 18 carbon atoms preferably has 12 or more carbon atoms, and more preferably has 14 or more carbon atoms. The alkyl group having 10 to 18 carbon atoms preferably does not have a hydroxyl group or a carboxyl group.

[0047] Specific examples of alkyl(meth)acrylates having a linear, cyclic, or branched structure and having 10 to 18 carbon atoms include isobornyl(meth)acrylate, lauryl(meth)acrylate, isomistyryl(meth)acrylate, isostearyl(meth)acrylate, isotridecyl(meth)acrylate, isopentadecyl(meth)acrylate, isohexadecyl(meth)acrylate, isoheptadecyl(meth)acrylate, etc. Of these, isostearyl(meth)acrylate or isobornyl(meth)acrylate is preferred.

[0048] In addition to the above, the (meth)acrylic acid ester may also be a (meth)acrylate having an alkyl group with 9 or less carbon atoms or a (meth)acrylate having an aromatic ring, and among these, a (meth)acrylate having an alkyl group with 9 or less carbon atoms is preferred. The alkyl group with 9 or less carbon atoms preferably does not have a hydroxyl group or a carboxyl group.

[0049] Examples of (meth)acrylates having an alkyl group or aromatic ring having 9 or less carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, isopropyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, and benzyl (meth)acrylate. Among these, in terms of ease of control of adhesive properties, (meth)acrylates having an alkyl group having 2 to 9 carbon atoms are more preferred, (meth)acrylates having an alkyl group having 3 to 9 carbon atoms are even more preferred, and (meth)acrylates having an alkyl group having 4 to 9 carbon atoms are particularly preferred. A preferred specific example of a (meth)acrylate having an alkyl group or aromatic ring having 9 or less carbon atoms is 2-ethylhexyl (meth)acrylate.

[0050] The (meth)acrylic acid ester units contained in the acrylic polymer may be of one type or two or more types.

[0051] The acrylic polymer may contain units other than (meth)acrylic acid ester units, for example, vinyl monomer units having a cyclic or acyclic substituent containing a nitrogen atom. That is, the acrylic polymer may be a polymer of monomers including a (meth)acrylic acid ester and a vinyl monomer having a cyclic or acyclic substituent containing a nitrogen atom.

[0052] Specific examples of vinyl monomers having an acyclic substituent containing a nitrogen atom include (meth)acrylamide and N-substituted (meth)acrylamide. Examples of N-substituted (meth)acrylamides include (meth)acrylamides in which one or two alkyl groups are substituted on the nitrogen atom. In N-substituted (meth)acrylamides, the alkyl group can be, for example, an alkyl group having 1 to 8 carbon atoms, preferably an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and even more preferably an alkyl group having 1 or 2 carbon atoms. When two alkyl groups are substituted on the nitrogen atom, the alkyl groups can be the same or different, and preferably the alkyl groups are the same.

[0053] In this specification, "(meth)acrylamide" means "acrylamide" or "methacrylamide".

[0054] Specific examples of N-substituted (meth)acrylamides include N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylamide, and tert-octylacrylamide.

[0055] Specific examples of vinyl monomers having a cyclic substituent containing a nitrogen atom include acryloylmorpholine.

[0056] The vinyl monomer unit having a cyclic substituent containing a nitrogen atom contained in the acrylic polymer may be one or two or more types.

[0057] The acrylic polymer may contain units other than the above-mentioned units, such as a monomer unit having a hydroxyl group. Examples of monomers for forming such a monomer unit having a hydroxyl group include (meth)acrylates having a hydroxyl group and (meth)acrylates having a carboxyl group.

[0058] Examples of (meth)acrylates having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2,2-dimethyl-2-hydroxyethyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, and polyalkylene glycol mono(meth)acrylate. Of these, 4-hydroxybutyl (meth)acrylate is preferred.

[0059] The acrylic polymer is preferably a polymer of a monomer containing one or more selected from the group consisting of an alkyl(meth)acrylate having a linear, cyclic, or branched alkyl group with 10 to 18 carbon atoms, a (meth)acrylate having an alkyl group with 9 or less carbon atoms, a vinyl monomer having an acyclic substituent containing a nitrogen atom, a vinyl monomer having a cyclic substituent containing a nitrogen atom, and a (meth)acrylate having a hydroxyl group, and more preferably a polymer of a monomer containing one or more selected from the group consisting of an alkyl(meth)acrylate having a linear, cyclic, or branched alkyl group with 10 to 18 carbon atoms, a (meth)acrylate having an alkyl group with 9 or less carbon atoms, and a vinyl monomer having an acyclic substituent containing a nitrogen atom.

[0060] The acrylic polymer may contain alkyl(meth)acrylate units having a linear, cyclic or branched alkyl group having 10 to 18 carbon atoms in an amount of 60 parts by mass or less, preferably 50 parts by mass or less, more preferably 45 parts by mass or less, and even more preferably 40 parts by mass or less, relative to 100 parts by mass of the acrylic polymer. The acrylic polymer does not necessarily contain alkyl(meth)acrylate units having a linear, cyclic or branched alkyl group having 10 to 18 carbon atoms.

[0061] The acrylic polymer may have a content of (meth)acrylate units having an alkyl group having 9 or less carbon atoms of 20 parts by mass or more, preferably 25 parts by mass or more, more preferably 30 parts by mass or more, and even more preferably 35 parts by mass or more, relative to 100 parts by mass of the acrylic polymer, and may have a content of 90 parts by mass or less, preferably 80 parts by mass or less, more preferably 70 parts by mass or less, and even more preferably 65 parts by mass or less.

[0062] The content of the vinyl monomer unit having an acyclic substituent containing a nitrogen atom in the acrylic polymer may be 5 parts by mass or more, preferably 10 parts by mass or more, more preferably 15 parts by mass or more, and even more preferably 20 parts by mass or more, relative to 100 parts by mass of the acrylic polymer, and may be 50 parts by mass or less, preferably 45 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 35 parts by mass or less.

[0063] The acrylic polymer may have a content of vinyl monomer units having a cyclic substituent containing a nitrogen atom of 20 parts by mass or more, preferably 25 parts by mass or more, and more preferably 30 parts by mass or more, relative to 100 parts by mass of the acrylic polymer, and may have a content of 50 parts by mass or less, preferably 45 parts by mass or less, and more preferably 40 parts by mass or less.

[0064] The acrylic polymer preferably contains 20 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, of the (meth)acrylate having a hydroxyl group relative to 100 parts by mass of the acrylic polymer. The content of the (meth)acrylate having a hydroxyl group may be 0 parts by mass.

[0065] The acrylic polymer preferably does not have a carboxyl group.

[0066] The weight-average molecular weight of the acrylic polymer is not particularly limited, and from the viewpoint of preventing a decrease in adhesive strength in the pressure-sensitive adhesive sheet, it can be, for example, 100,000 to 2,000,000, and more preferably 300,000 to 1,000,000. Note that the weight-average molecular weight referred to in the present invention refers to the weight-average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

[0067] There are no particular limitations on the GPC apparatus used in the GPC method, and commercially available GPC measuring instruments, such as the LC-2000Plus series manufactured by JASCO Corporation, and detectors such as RI-2031Plus and UV-2075Plus, can be used. In this case, for example, a GPC column consisting of four columns connected together, namely, "Shodex KF801," "Shodex KF803L," "Shodex KF800L," and "Shodex KF800D" manufactured by Showa Denko K.K., can be used. The column temperature can be set to 40°C. Tetrahydrofuran is used as the eluent, and measurements are performed at a flow rate of 1.0 ml / min. Typically, a calibration curve is prepared using standard polystyrene, and the weight average molecular weight (Mw) can be obtained in polystyrene equivalent terms.

[0068] The glass transition temperature (Tg) of the acrylic polymer is not particularly limited and can be, for example, from -60 to 0°C, preferably from -50 to -10°C, and more preferably from -40 to -20°C.

[0069] The method for adjusting the glass transition temperature of the acrylic polymer is not particularly limited, and the glass transition temperature can be adjusted to a desired range by, for example, changing the type and composition ratio of the monomers constituting the acrylic polymer. In the present invention, the glass transition temperature of the acrylic polymer refers to Tg, which is calculated by the following Fox formula based on the composition of the monomers used in synthesizing the polymer. Fox formula: 1 / Tg = (W1 / Tg1) + (W2 / Tg2) + ... + (Wm / Tgm), where W1 + W2 + ... + Wm = 1. In the formula, Tg is the glass transition temperature (unit: K) of the acrylic polymer, Tg1, Tg2, ..., Tgm are the glass transition temperatures of the respective homopolymers of m types of monomers (m is an integer) constituting the acrylic polymer, and W1, W2, ..., Wm are the mass fractions of the respective structural units in the acrylic polymer. Note that Tg1 and W1 correspond to each other, i.e., the monomer that constitutes the homopolymer exhibiting the glass transition temperature of Tg1 is the same as the monomer that forms the structural unit having the mass fraction of W1. Similarly, Tg2 and W2, ... Tgm and Wm correspond to each other.

[0070] The glass transition temperature of the homopolymer can be, for example, the value described in the Polymer Handbook 4th Edition (Wiley-Interscience 2003). If no such handbook is available, the glass transition temperature of the homopolymer can be measured, for example, by a differential scanning calorimeter (DSC). The DSC measurement conditions are as follows: 5 mg of sample in a nitrogen atmosphere; in the first measurement (1st RUN), the sample is heated from -100°C to 200°C at a heating rate of 5°C / min, then cooled to -100°C at a cooling rate of 5°C / min; and in the second measurement (2nd RUN), the sample is heated from -100°C to 200°C at a heating rate of 5°C / min. Here, the glass transition temperature refers to the intersection of an extension of the baseline on the lower temperature side of the region where the baseline of a DSC curve measured when the temperature is raised from −100° C. to 200° C. changes to a sigmoid shape in the endothermic direction, and a tangent to an inflection point in the sigmoid.

[0071] The acrylic polymer can be produced, for example, by polymerizing a monomer mixture for forming each structural unit by a known polymerization method. Examples of the polymerization method that can be used include solution polymerization, bulk polymerization, suspension polymerization, and emulsion polymerization. The ratio of each structural unit in the acrylic polymer corresponds to the ratio of each monomer used during polymerization. The types of solvent and polymerization initiator used in the polymerization are not particularly limited, and for example, solvents and polymerization initiators used in the production of known acrylic polymers can be used.

[0072] The acrylic polymer can be produced by a known method. For example, the acrylic polymer can be produced by polymerizing a monomer mixture for forming each structural unit by a known polymerization method. In this case, the acrylic polymer may be a partially polymerized product, that is, a state in which a portion of the monomers used in the polymerization remains unpolymerized.

[0073] When the base agent contains a polymerizable monomer, the type thereof is not particularly limited, and for example, a wide variety of monomers used to form known pressure-sensitive adhesive sheets or coatings can be used. For example, the aforementioned (meth)acrylic acid ester unit, a vinyl monomer unit having a cyclic or acyclic substituent containing a nitrogen atom, a monomer unit having a hydroxyl group, a (meth)acrylate having a carboxyl group, etc. can be used as the polymerizable monomer. Note that the polymerizable monomer does not include the polyfunctional monomer described below. Preferably, the polymerizable monomer is a monofunctional monomer.

[0074] Examples of (meth)acrylic acid esters that can be included in the polymerization component monomer include the aforementioned alkyl(meth)acrylates having a linear, cyclic, or branched alkyl group having 10 to 18 carbon atoms, and (meth)acrylates having an alkyl group having 9 or less carbon atoms. The types of vinyl monomers having a cyclic or acyclic substituent containing a nitrogen atom contained in the polymerizable monomer are similar to those described above. Accordingly, specific examples of vinyl monomers having an acyclic substituent containing a nitrogen atom include (meth)acrylamide and N-substituted (meth)acrylamide. Specific examples of N-substituted (meth)acrylamides include N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylamide, and tert-octylacrylamide. Specific examples of vinyl monomers having a cyclic substituent containing a nitrogen atom include acryloylmorpholine.

[0075] When the base agent contains both the above-mentioned acrylic polymer and polymerizable monomer, for example, the base agent is a so-called syrup. For example, when the acrylic polymer is a so-called partially polymerized product, the base agent can be a syrup containing both the acrylic polymer and the polymerizable monomer. The polymer fraction of the partially polymerized product is not particularly limited and can be, for example, 1 to 50% by mass, and preferably 20 to 40% by mass. The polymer fraction is the content (% by mass) of the resin component relative to the total mass of the resin component (acrylic polymer and polymerizable monomer).

[0076] When the base agent consists of only an acrylic polymer or contains an acrylic polymer, the curable composition of the present invention is preferably a raw material for producing a pressure-sensitive adhesive sheet. When the base agent contains a polymerizable monomer, the curable composition of the present invention is preferably a raw material for producing a pressure-sensitive adhesive sheet or film.

[0077] (Photopolymerization initiator) The sulfur-preventing curable composition of the present invention may contain a photopolymerization initiator. The type of photopolymerization initiator is not particularly limited. The photopolymerization initiator can initiate a polymerization reaction by irradiation with active energy rays. In this specification, "active energy rays" refers to electromagnetic waves or charged particle rays that have an energy quantum, and examples thereof include ultraviolet rays, electron beams, visible light, X-rays, and ion beams. From the viewpoint of versatility, ultraviolet rays or electron beams are preferred, and ultraviolet rays are particularly preferred.

[0078] The photopolymerization initiator may be, for example, a self-cleavage type photoradical polymerization initiator. Note that the self-cleavage type photoradical polymerization initiator is other than the hydrogen abstraction type photopolymerization initiator described below.

[0079] The type of self-cleavage type photoradical polymerization initiator is not particularly limited, and examples thereof include acetophenone-based initiators, benzoin ether-based initiators, hydroxyalkylphenone-based initiators, thioxanthone-based initiators, amine-based initiators, and acylphosphine oxide-based initiators.

[0080] Specific examples of acetophenone-based initiators include diethoxyacetophenone and benzyl dimethyl ketal. Specific examples of benzoin ether-based initiators include benzoin and benzoin methyl ether. Specific examples of hydroxyalkylphenone-based initiators include 1-hydroxycyclohexylphenyl ketone. Specific examples of thioxanthone-based initiators include 2-isopropylthioxanthone and 2,4-dimethylthioxanthone. Specific examples of amine-based initiators include triethanolamine and ethyl 4-dimethylbenzoate. Specific examples of acylphosphine oxide-based initiators include phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

[0081] The self-cleavage type photoradical polymerization initiator can be produced by a known method or can be obtained from a commercially available product. Examples of commercially available products include EsacureOne, Omnirad 184, Omnirad 819, Omnirad 1173, Omnirad 2959, Omnirad 127, Omnirad 907, Omnirad 369, Omnirad 379EG, Omnirad TPO, Omnirad TPO H, Irgacure OXE01, and Irgacure OXE02, all manufactured by IGM RESINS B.V.

[0082] The photopolymerization initiator may be a self-cleavage type radical photopolymerization initiator or other photopolymerization initiators, such as a hydrogen abstraction type photopolymerization initiator. The hydrogen abstraction type photopolymerization initiator is a photopolymerization initiator in which an initiator photoexcited by irradiation with active energy rays and a hydrogen donor in the system form an exciplex, and the hydrogen from the hydrogen donor is transferred to promote polymerization. Therefore, the hydrogen abstraction type photopolymerization initiator not only initiates the polymerization reaction of the polyfunctional monomer and other polymerizable components that may be contained, but also acts on the (meth)acrylic copolymer to form a crosslinked structure.

[0083] The type of hydrogen abstraction photopolymerization initiator is not particularly limited, and examples thereof include benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, 3,3'-dimethyl-4-methoxybenzophenone, 2,4,6-trimethylbenzophenone, 4-methylbenzophenone, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, camphorquinone, dibenzosuberone, 2-ethylanthraquinone, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone, benzil, 9,10-phenanthrenequinone, etc. Among these, the hydrogen abstraction photopolymerization initiator is preferably a benzophenone-based photopolymerization initiator. Examples of benzophenone-based photopolymerization initiators include benzophenone, 4-methylbenzophenone, and 2,4,6-trimethylbenzophenone. Hydrogen abstraction photopolymerization initiators can be produced by known methods, or can be obtained from commercially available products. Examples of commercially available products include TZT and MBF manufactured by IGM Resins, and "SPEED CURE MBP" (e.g., "4MBP") manufactured by Lambson.

[0084] The content of the photopolymerization initiator is 0.1 parts by mass or more and 10 parts by mass or less, preferably 0.1 parts by mass or more, more preferably 0.2 parts by mass or more, more preferably 5 parts by mass or less, even more preferably 2 parts by mass or less, still more preferably 0.5 parts by mass or less, and particularly preferably 0.4 parts by mass or less, relative to 100 parts by mass of the acrylic adhesive resin.

[0085] The photopolymerization initiator contained in the sulfur-preventing curable composition may be one kind or two or more kinds.

[0086] (Polyfunctional Monomer) The sulfuration-preventing curable composition preferably contains a polyfunctional monomer. Examples of the polyfunctional monomer include compounds having two or more polymerizable double bonds in the molecule. The polyfunctional monomer has two or more polymerizable double bonds (e.g., radically polymerizable double bonds), preferably two or more but less than five, and more preferably two or more but less than four.

[0087] Examples of polyfunctional monomers include bifunctional monomers (monomers having two polymerizable double bonds), such as polyethylene glycol diacrylate, polypropylene diacrylate, alkyl diacrylate, polytetramethylene glycol diacrylate, polypropylene glycol diacrylate, dioxane diacrylate, tricyclodecanol diacrylate, and fluorene diacrylate. Examples of polyfunctional monomers include trifunctional or higher functional monomers, such as alkoxylated trimethylolpropane triacrylate, alkoxylated glycerin triacrylate, caprolactone-modified isocyanurate triacrylate, pentaerythritol acrylate, alkoxylated pentaerythritol acrylate, (alkoxylated) pentaerythritol acrylate, (alkoxylated) ditrimethylolpropane acrylate, (alkoxylated) dipentaerythritol acrylate, (ethoxylated) polyglycerin acrylate, polyfunctional urethane acrylate, and polyfunctional oligomers such as acrylic-terminated polybutadiene (olefin).

[0088] When the polyfunctional monomer is a polyfunctional monomer having an alkylene glycol group in one molecule, the number of alkylene glycol groups in one molecule is preferably 1 to 20. Examples of such polyfunctional monomers include polyethylene glycol diacrylate and trimethylolpropane propylene oxide modified triacrylate.

[0089] The polyfunctional monomer may be, for example, a commercially available product. Examples of commercially available products include "A-200" (polyethylene glycol #200 diacrylate) and "A-400" (polyethylene glycol #400 diacrylate) from the NK Ester series, which are bifunctional polyethylene glycol acrylates manufactured by Shin-Nakamura Chemical Co., Ltd., the trifunctional "ATM-4PL" (pentaerythritol triacrylate), the trifunctional monomer M310 (trimethylolpropane PO-modified triacrylate) and the trifunctional monomer M321 (trimethylolpropane propylene oxide-modified triacrylate) manufactured by Toagosei Co., Ltd., and the bifunctional monomer M211B (bisphenol A EO-modified diacrylate) manufactured by Toagosei Co., Ltd.

[0090] The polyfunctional monomer may have a bisphenol skeleton in one molecule, such as a diacrylate of bisphenol A diglycidyl ether, a diacrylate of propoxylated bisphenol A, or a diacrylate of bisphenol F diglycidyl ether.

[0091] When the sulfuration-preventing curable composition contains a polyfunctional monomer, curing the sulfuration-preventing curable composition with active energy rays forms a crosslinked polymer, which tends to provide the pressure-sensitive adhesive sheet with excellent adhesive strength or to improve the strength of the film. The sulfuration-preventing curable composition can contain one type of polyfunctional monomer alone or two or more types of polyfunctional monomer.

[0092] The content of the polyfunctional monomer in the sulfurization-preventing curable composition is not particularly limited. For example, when the main agent contained in the sulfurization-preventing curable composition contains the acrylic polymer, the content of the polyfunctional monomer can be 5 parts by mass or less, preferably 3 parts by mass or less, more preferably 1 part by mass or less, even more preferably 0.5 parts by mass or less, and particularly preferably 0.3 parts by mass or less, per 100 parts by mass of the main agent. Furthermore, when the main agent contained in the sulfurization-preventing curable composition contains the acrylic polymer, the content of the polyfunctional monomer is preferably 0.01 parts by mass or more, more preferably 0.02 parts by mass or more, and even more preferably 0.03 parts by mass or more, per 100 parts by mass of the main agent.

[0093] When the main component contained in the sulfurization-preventing curable composition consists solely of the polymerizable monomer, the polyfunctional monomer may be contained in an amount of 60 parts by mass or less, preferably 50 parts by mass or less, more preferably 45 parts by mass or less, even more preferably 40 parts by mass or less, and particularly preferably 35 parts by mass or less, per 100 parts by mass of the main component. Furthermore, when the polymerizable component contained in the sulfurization-preventing curable composition is polymerizable component B, the polyfunctional monomer is contained in an amount of 5 parts by mass or more, more preferably 10 parts by mass or more, even more preferably 15 parts by mass or more, and particularly preferably 20 parts by mass or more, per 100 parts by mass of the main component.

[0094] (Sulfuration-Preventing Curable Composition) In the sulfuration-preventing curable composition of the present invention, when the content of the phosphite ester compound per 100 parts by mass of the base agent is A parts by mass and the number of phosphorous moieties in the phosphite ester compound is B, the following formula (1) is satisfied: A×B≧0.5 (1). As a result, the sulfuration-preventing curable composition of the present invention can form a pressure-sensitive adhesive sheet or film that can inhibit the sulfuration of metals. For example, when the base agent does not contain a polymerizable monomer and consists solely of an acrylic polymer, "100 parts by mass of the base agent" can be interpreted as "100 parts by mass of the acrylic polymer." For example, when the base agent contains both an acrylic polymer and a polymerizable monomer, "100 parts by mass of the base agent" can be interpreted as "100 parts by mass of the total amount of the acrylic polymer and the polymerizable monomer."

[0095] When the value of A × B is less than 0.5, the adhesive sheet or film obtained from the sulfuration-preventing curable composition of the present invention is significantly impaired in its ability to inhibit sulfuration of metals. The value of A × B is preferably 0.55 or more, more preferably 0.58 or more, and even more preferably 0.6 or more. The value of A × B can be 10 or less, preferably 5 or less, more preferably 3 or less, even more preferably 2 or less, even more preferably 1.5 or less, and particularly preferably 1 or less. When the value of A × B is 1.5 or less, the adhesive sheet or film obtained from the curable composition is likely to have excellent optical properties even in high-temperature and high-humidity environments.

[0096] In the sulfurization-preventing curable composition of the present invention, the content of the phosphite ester compound can be adjusted within a range that satisfies the above formula (1). For example, the content of the phosphite ester compound (i.e., the value of A) per 100 parts by mass of the base agent is preferably 0.25 parts by mass or more, more preferably 0.3 parts by mass or more, and is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 5 parts by mass or less, and particularly preferably 3 parts by mass or less.

[0097] As described above, the sulfur-preventing curable composition contains a base agent and a phosphite ester compound as essential components, and may optionally contain a photopolymerization initiator and a polyfunctional monomer. A crosslinking agent may be included instead of the photopolymerization initiator and the polyfunctional monomer. Examples of the crosslinking agent include known thermal crosslinking agents such as isocyanate compounds, epoxy compounds, oxazoline compounds, aziridine compounds, metal chelate compounds, and butylated melamine compounds. In particular, an isocyanate compound or an epoxy compound is preferred as the crosslinking agent. Examples of the isocyanate compound include TDI (tolylene diisocyanate), XDI (xylylene diisocyanate), and HDI (hexamethylene diisocyanate)-based isocyanate compounds.

[0098] The content of the crosslinking agent is preferably 0.005 parts by mass or more, more preferably 0.01 parts by mass or more, even more preferably 0.02 parts by mass or more, and particularly preferably 0.05 parts by mass or more, relative to 100 parts by mass of the main agent. The content of the thermal crosslinking agent is preferably 0.5 parts by mass or less, more preferably 0.3 parts by mass or less, even more preferably 0.2 parts by mass or less, even more preferably 0.1 parts by mass or less, and particularly preferably 0.08 parts by mass or less, relative to 100 parts by mass of the main agent.

[0099] The sulfuration-preventing curable composition may further contain a silane coupling agent, a solvent, etc. Furthermore, a dye or a pigment may be added to the adhesive for the purpose of coloring. It is also preferable that the sulfuration-preventing curable composition does not contain a solvent, i.e., is solvent-free.

[0100] The sulfurization-preventing curable composition may also contain a rust inhibitor such as 1,2,3-benzotriazole. When the sulfurization-preventing curable composition contains a rust inhibitor, the content thereof may be 0 to 1 part by mass per 100 parts by mass of the main agent. However, even when the sulfurization-preventing curable composition contains 1,2,3-benzotriazole, the effect of 1,2,3-benzotriazole in inhibiting sulfurization is not enhanced.

[0101] The method for preparing the curable composition for preventing sulfurization is not particularly limited, and any known method can be widely adopted. For example, the curable composition for preventing sulfurization can be prepared by mixing a base agent, a phosphite ester compound, a photopolymerization initiator, and a polyfunctional monomer.

[0102] The sulfuration-preventing curable composition is photocurable. For example, the sulfuration-preventing curable composition undergoes a curing reaction when exposed to active energy rays, allowing it to form a pressure-sensitive adhesive sheet, a coating, or the like.

[0103] The sulfuration-preventing curable composition can form an adhesive sheet or film capable of suppressing the sulfuration of metals. In particular, when the base agent contains an acrylic polymer, the sulfuration-preventing curable composition can form an adhesive sheet capable of suppressing the sulfuration of metals. Furthermore, when the base agent contains a polymerizable monomer, the sulfuration-preventing curable composition can form a film (coating film) or adhesive sheet capable of suppressing the sulfuration of metals. This is particularly suitable for suppressing the sulfuration of metal layers formed of metals including silver or copper. Preferably, such a metal layer has a mesh structure, for example.

[0104] That is, the metal for which sulfurization is suppressed by the sulfurization-preventing curable composition is silver or copper, and a metal layer having a mesh structure is preferable, and among these, silver is preferable. Examples of the metal layer include copper nanowires and silver nanowires.

[0105] 2. Pressure-sensitive adhesive sheet: The pressure-sensitive adhesive sheet can be obtained by curing the sulfurization-preventing curable composition. That is, the pressure-sensitive adhesive sheet contains a cured product of the sulfurization-preventing curable composition. In this case, it is preferable that the base agent contains an acrylic polymer.

[0106] The method for forming the pressure-sensitive adhesive sheet is not particularly limited, and may include, for example, a step of applying the sulfurization-preventing curable composition to a substrate to form a coating film, and a step of irradiating the coating film with active energy rays to cure the coating film and obtain a pressure-sensitive adhesive sheet. The sulfurization-preventing curable composition can be applied using a known coating device. Examples of the coating device include a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a microgravure coater, a rod blade coater, a lip coater, a die coater, and a curtain coater.

[0107] The substrate used for coating is not particularly limited. For example, the sulfur-preventing curable composition can be coated on a release sheet described below. The thickness after coating is also not particularly limited and can be appropriately set depending on the desired thickness. After forming the coating film, the coating film may be subjected to a heat treatment or a drying treatment, if necessary.

[0108] The method of irradiating the coating film with active energy is not particularly limited. For example, ultraviolet light can be applied at an integrated light dose of 100 to 10,000 mJ / cm. ２ It is preferable to set the value to 200 to 5000 mJ / cm ２ It is more preferable to set it so that:

[0109] The cured product formed as described above can be used as the pressure-sensitive adhesive sheet of the present invention. The pressure-sensitive adhesive sheet may consist of only a layer formed of the cured product of the sulfur-preventing curable composition, or may contain other layers in addition to the layer formed of the cured product. The pressure-sensitive adhesive sheet of the present invention preferably has, for example, a single-layer structure.

[0110] The gel fraction of the pressure-sensitive adhesive sheet of the present invention is not particularly limited, and is, for example, 20% or more and 90% or less, preferably 25% or more, more preferably 30% or more, and preferably 85% or less, more preferably 80% or less.

[0111] The gel fraction of the PSA sheet is a value measured by the following method. First, approximately 0.1 g of the PSA sheet is collected in a sample bottle, 30 ml of ethyl acetate is added, and the mixture is shaken at 40°C for 24 hours. The contents of the sample bottle are then filtered through a 150-mesh stainless steel wire mesh, and the residue on the wire mesh is dried at 100°C for 1 hour to measure the dry mass (g). The gel fraction is calculated from the obtained dry mass using the following formula: Gel fraction (mass%) = (dry mass / collected mass of PSA sheet) x 100...Equation 11.

[0112] The thickness of the pressure-sensitive adhesive sheet of the present invention can be appropriately set depending on the application, and is, for example, preferably 10 to 1000 μm, more preferably 20 to 500 μm.

[0113] The pressure-sensitive adhesive sheet of the present invention can also be a pressure-sensitive adhesive sheet provided with a substrate such as a release sheet on one or both sides. Examples of release sheets include a release laminate sheet having a release sheet substrate and a release agent layer provided on one side of the release sheet substrate, or a polyolefin film such as a polyethylene film or a polypropylene film as a low-polarity substrate. Paper or a polymer film is used as the release sheet substrate in the release laminate sheet. Examples of release agents that constitute the release agent layer include general-purpose addition-type or condensation-type silicone-based release agents and long-chain alkyl group-containing compounds. Commercially available release laminate sheets may also be used. Examples include a heavy-duty separator film, which is a release-treated polyethylene terephthalate film manufactured by Oji F-Tex Co., Ltd., and a light-duty separator film, which is a release-treated polyethylene terephthalate film manufactured by Oji F-Tex Co., Ltd.

[0114] The pressure-sensitive adhesive sheet of the present invention is formed using the curable composition for sulfidation prevention, and therefore can suppress the sulfidation of metals. In particular, the pressure-sensitive adhesive sheet of the present invention can be suitably used for preventing the sulfidation of a metal layer having a mesh structure, more preferably for preventing the sulfidation of a metal layer having a mesh structure formed from a metal containing silver or copper, and particularly preferably for preventing the sulfidation of a metal layer having a mesh structure formed from a metal containing silver.

[0115] In addition, the pressure-sensitive adhesive sheet of the present invention also has excellent optical properties, for example, it can reduce the haze and b* value, and the haze and b* value are less likely to increase even when placed under high temperature or high temperature and high humidity environments.

[0116] 3. The coating can be obtained by curing the sulfuration-preventing curable composition. That is, the pressure-sensitive adhesive sheet contains a cured product of the sulfuration-preventing curable composition. In this case, it is preferable that the base agent contains a polymerizable monomer.

[0117] The method for forming the film is not particularly limited, and for example, methods similar to those for forming known coating films can be widely used. Alternatively, the film can be formed using a method similar to the method for forming the pressure-sensitive adhesive sheet described above. In this case, the member to be coated with the sulfidation-preventing curable composition is directly coated onto the member on which the film is to be formed, thereby forming the film. Therefore, the substrate used for coating to form the film is preferably a metal layer formed of a metal containing silver or copper and having a mesh structure.

[0118] The coating may consist solely of a layer formed from the cured product of the sulfuration-preventing curable composition, or may contain other layers in addition to the layer formed from the cured product. The coating of the present invention preferably has, for example, a single-layer structure.

[0119] The thickness of the coating of the present invention can be appropriately set depending on the application, and is, for example, preferably 0.1 to 20 μm, more preferably 0.5 to 10 μm, and even more preferably 1 to 5 μm.

[0120] The coating of the present invention is formed using the sulfidation-preventing curable composition, and therefore can suppress sulfidation of metals. In particular, the coating can be suitably used to prevent sulfidation of metal layers having a mesh structure formed from a metal containing silver or copper, and is particularly suitable for preventing sulfidation of metal layers having a mesh structure formed from a metal containing silver.

[0121] 4. Display device components including pressure-sensitive adhesive sheets The pressure-sensitive adhesive sheets formed using the curable composition for preventing sulfidation have excellent performance in preventing the sulfidation of metals, and can therefore be suitably used, for example, in display device components including touch sensor films.

[0122] In the display device member, the touch sensor film may include a laminate including an adhesive sheet formed using the sulfidation-preventing curable composition and a metal layer having a mesh structure, wherein the adhesive sheet is attached to at least one side of the metal layer, and the metal layer is preferably silver or copper.

[0123] The adhesive sheet is preferably directly attached to the metal layer. The touch sensor film may have the same configuration as a known touch sensor film, for example, as long as it includes the adhesive sheet and the metal layer.

[0124] The display device member includes an adhesive sheet to suppress sulfurization of the metal layer, thereby making it less likely for the touch sensor to deteriorate in sensitivity and malfunction. The configuration of the display device member is not particularly limited, and can be, for example, the same configuration as that of a display device member including a known touch sensor film. The display device member can include, for example, a glass plate, a polarizing plate, etc. As long as the adhesive sheet of the present invention is attached to the metal layer, each component constituting the display device member may be attached with another adhesive sheet, or a component other than the metal layer may be attached with the adhesive sheet of the present invention. The display device member can be suitably applied to various display devices.

[0125] 5. Uses of the Film The film formed using the curable composition for preventing sulfuration has excellent sulfuration prevention performance for metals, and can therefore be suitably used, for example, in display device components including touch sensor films.

[0126] In the display device member, the touch sensor film may include a laminate including a coating formed using the sulfidation-preventing curable composition and a metal layer having a mesh structure, and in this case, the coating is formed on at least one side of the metal layer, and the metal layer is preferably made of silver or copper.

[0127] The coating is preferably formed directly on the metal layer. The touch sensor film may have the same configuration as a known touch sensor film, as long as it includes the coating and the metal layer.

[0128] The display device member is provided with a coating to suppress sulfurization of the metal layer, thereby making it less likely for the touch sensor to deteriorate in sensitivity and malfunction. The configuration of the display device member is not particularly limited, and can be, for example, the same configuration as a display device member provided with a known touch sensor film. The display device member can include, for example, a glass plate, a polarizing plate, etc. The components constituting the display device member may be bonded together with, for example, a known pressure-sensitive adhesive sheet, or may be bonded together with the pressure-sensitive adhesive sheet of the present invention described above. The display device member can be suitably applied to various display devices.

[0129] In specifying the inventions included in the present disclosure, the components (properties, structures, functions, etc.) described in each embodiment of the present disclosure may be combined in any manner. In other words, the present disclosure includes all subject matter consisting of all combinations of the components that can be combined as described in this specification.

[0130] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

[0131] (Production Example 1) A monomer mixture consisting of 2-ethylhexyl acrylate (2-EHA), isostearyl acrylate (ISTA), N,N-dimethylacrylamide (DMAA), and N,N-diethylacrylamide (DEAA) was prepared in this order in a mass ratio of 40:35:15:10. This monomer mixture was charged into a reaction vessel equipped with a stirrer, a cooling tube, a thermometer, and a nitrogen inlet tube. 0.05 parts by mass of 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator was also charged into the reaction vessel. The mixture was then heated at an illuminance of 3 mW / cm while introducing nitrogen gas. ２ The resulting acrylic polymer was partially polymerized by irradiation with ultraviolet light of 1000 W at 1000 W / m², thereby obtaining a base resin 1 containing an acrylic polymer with a conversion rate of 31%. The weight average molecular weight Mw of the resulting acrylic polymer, as determined by GPC in terms of polystyrene, was 570,000, the viscosity at a liquid temperature of 23°C was 6,900 mPa s, and the theoretical Tg was −24°C.

[0132] (Production Example 2) Partial polymerization was carried out in the same manner as in Production Example 1, except that the mixed monomer was changed to a mixed monomer consisting of 2-EHA, DMAA, 4-hydroxybutyl acrylate (4HBA), and 2-ethylhexyl methacrylate (mass ratio, in this order, 60:30:5:5), to obtain a main component 2 containing an acrylic polymer with a conversion rate of 30%. The polystyrene-equivalent weight average molecular weight Mw of the obtained acrylic polymer measured by GPC was 570,000, the viscosity at a liquid temperature of 23°C was 6,900 mPa s, and the theoretical Tg was -24°C.

[0133] (Phosphite Ester Compound) In the examples and comparative examples, any of phosphite ester compounds 1 to 8 shown in Table 1 below was used. For example, phosphite compound No. 1 shown in Table 1 is represented as "phosphite ester compound 1." In Table 1, "number of phosphite moieties" refers to the number of phosphite moieties in the phosphite ester compound, and "number of phenyl moieties" refers to the number of phenyl moieties bonded to each phosphite moiety in the phosphite ester compound.

[0134]

[0135] Example 1 A curable composition was obtained by mixing 100 parts by mass of the base compound 1 (containing an acrylic polymer) obtained in Production Example 1 with 0.04 parts by mass of ATM-4PL (Shin-Nakamura Chemical Co., Ltd.) as a polyfunctional monomer, 0.3 parts by mass of Omnirad 184 (manufactured by IGM Resins) as a photopolymerization initiator, and 0.6 parts by mass of the phosphite ester compound 1 shown in Table 1 as a phosphite ester compound. Therefore, the value of A×B calculated from the above formula (1) was set to 0.6. This curable composition was uniformly applied with an applicator to the surface of a 100 μm-thick polyethylene terephthalate film (first release sheet) (manufactured by Oji F-Tex Co., Ltd.: 100RL-07(2)) having a release agent layer treated with a silicone-based release agent, so that the coating film thickness after drying would be 150 μm. A 75 μm thick polyethylene terephthalate film (second release sheet) (Oji F-Tex Co., Ltd.: 75RL-07(L)) with a release agent layer treated with a silicone-based release agent was laminated on the coated surface, and then a black light was irradiated from the first release sheet side with an illuminance of 4 mW / cm at 365 nm. ２ The cumulative light intensity is 240 mJ / cm ２ Then, a high-pressure mercury lamp was used to irradiate the light at an illuminance of 100 mW / cm at 365 nm. ２ The illuminance integrated light amount is 1000 mJ / cm ２ Then, a metal halide lamp was used to illuminate the object at an illuminance of 150 mW / cm ２ The cumulative light intensity is 1500 mJ / cm ２ By irradiating the film so as to achieve the above, a double-sided pressure-sensitive adhesive sheet with a release sheet was obtained, which had a configuration of first release sheet / pressure-sensitive adhesive layer / second release sheet, in which the pressure-sensitive adhesive layer was sandwiched between a pair of release sheets having different release strengths.

[0136] (Examples 2 to 8) Curable compositions were prepared by changing the type and amount of phosphite ester compound and the value of A × B as shown in Table 2, and double-sided PSA sheets with release sheets were obtained in the same manner as in Example 1, except that the thicknesses of the PSA layers were changed as shown in Table 2.

[0137] (Example 9) A double-sided PSA sheet with a release sheet was obtained in the same manner as in Example 7, except that main component 1 (containing an acrylic polymer) was changed to main component 2 (containing an acrylic polymer) obtained in Production Example 2.

[0138] Comparative Examples 1 to 7 Curable compositions were prepared by changing the type and amount of phosphite ester compound and the value of A×B as shown in Table 3, and double-sided PSA sheets with release sheets were obtained in the same manner as in Example 1, except that the thickness of the PSA layer was changed to the thickness shown in Table 3.

[0139] Comparative Examples 8 and 9 Double-sided PSA sheets with release sheets were obtained in the same manner as in Example 1, except that no phosphite ester compound was used and instead 1,2,3-benzotriazole was blended in the amount shown in Table 1 to prepare a curable composition.

[0140] [Evaluation Method] (Evaluation of Anti-sulfuration Performance) <Preparation of Conductive Film for Evaluation> A mesh-shaped pattern having measurement electrodes on both ends was printed by screen printing using silver paste (RAFS059" manufactured by Toyochem Co., Ltd.) on a 100 μm thick PET film (Komoshine A4360 manufactured by Toyobo Co., Ltd.) that had been treated for easy adhesion. The silver paste was then cured by heat treatment at 135° C. for 30 minutes, thereby obtaining a conductive film for evaluation equipped with silver wiring. The mesh pattern had a pitch of 50 μm and a line width of 5 μm.

[0141] <Preparation of Evaluation Sample> Next, the separator on the light release side of the pressure-sensitive adhesive sheet prepared in the Examples and Comparative Examples was peeled off, and a 100 μm PET film (Cosmoshine A4360 manufactured by Toyobo Co., Ltd.) was attached to the pressure-sensitive adhesive surface with a hand roller to obtain a laminate having a configuration of PET film / pressure-sensitive adhesive layer / heavy release side separator. Next, the separator on the heavy release side was peeled off from the laminate, and the pressure-sensitive adhesive layer (pressure-sensitive adhesive sheet) was attached to the silver wiring of the conductive film for evaluation prepared above. This was autoclaved for 30 minutes under conditions of 30°C and 0.5 MPa, and then left to stand for 24 hours under conditions of 23°C and 50% RH to prepare evaluation sample S.

[0142] <Resistance Change Rate After Sulfur Treatment (Sulfuration Resistance Evaluation)> The initial electrical resistance between the measurement electrodes at both ends of the conductive portion of the evaluation sample S obtained as described above was measured using a tester. Then, 0.5 mg of sulfur powder (manufactured by Wako Pure Chemical Industries, Ltd.) was weighed out into a 200 mL mayonnaise bottle, and the evaluation sample was placed in the bottle so as not to come into contact with the sulfur powder. After the lid was closed, the bottle was treated in an oven at 70°C for 240 hours (10 days). The evaluation sample S treated in this manner was removed from the mayonnaise bottle, and the PET film and adhesive sheet layer were partially peeled off to expose the electrode portion. The electrical resistance was measured using a tester, and this was designated as the "electrical resistance value after durability testing." In this way, the initial electrical resistance value and the electrical resistance value after durability were measured twice (n = 2) and the average value of each was calculated. Based on this average value, the resistance change rate was calculated using the following formula (2): Resistance change rate = Ra / Rb (2) (In formula (2), Ra is the average value of the electrical resistance value after durability (n = 2), and Rb is the average value of the initial electrical resistance value (n = 2)). If the resistance change rate is less than 1.5, the adhesive sheet was determined to have excellent performance in suppressing sulfurization of metals. Note that no lifting, peeling, or bubble formation occurred in any of the samples of the examples and comparative examples.

[0143] <Resistance change rate under high temperature and high humidity environment (high temperature and high humidity resistance)> The initial electrical resistance between the measurement electrodes at both ends of the conductive portion of the evaluation sample obtained as described above was measured using a tester. Then, 0.5 mg of sulfur powder (manufactured by Wako Pure Chemical Industries, Ltd.) was weighed into a 200 mL mayonnaise bottle, and the evaluation sample was placed in the bottle so as not to come into contact with the sulfur powder. After the lid was closed, the treatment was carried out at 85 ° C. and 85% RH for 240 hours. The evaluation sample S thus treated was removed from the mayonnaise bottle, and the PET film and the adhesive sheet layer were partially peeled off to expose the electrode portion, and the electrical resistance value after durability was measured using a tester. In this way, the initial electrical resistance value and the electrical resistance value after durability were measured twice (n = 2) and the average value was calculated, and the resistance change rate was calculated using the above formula (2). If the resistance change rate was less than 1.5, the adhesive sheet was determined to have excellent performance in suppressing sulfurization of metals.

[0144] (Haze and b* value of adhesive sheet) The adhesive sheet with release sheet was cut into a size of 50 mm x 50 mm, and the light separator was peeled off, and the exposed adhesive layer was attached to a glass plate (S9112, manufactured by Matsunami Glass Co., Ltd.). Next, the heavy separator was peeled off, and a glass plate (S9112, manufactured by Matsunami Glass Co., Ltd.) was attached to the exposed adhesive layer, and the sheet was placed in an autoclave. The autoclave was kept under a pressure of 0.5 MPa and treated at 40 ° C. for 30 minutes to obtain a laminate for evaluation. Using this laminate for evaluation, the haze and b* value were measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., "NDH5000") and a color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd., "SE2000"). The haze and b* value measured in this way were used as initial values. In addition, the treatment conditions were changed from "40°C, 30 minutes" to "85°C, 10 days," "60°C, 95% RH, 10 days," "85°C, 85% RH, 10 days," and "10 days after UV irradiation," and the haze and b* value were obtained in the same manner for each case.

[0145] (Evaluation Results) Tables 2 and 3 show the compounding conditions for preparing the curable compositions for preventing sulfurization of each Example and Comparative Example, and the evaluation results of the resulting pressure-sensitive adhesive sheets. In Tables 2 and 3, blank spaces indicate that the corresponding raw material was not used.

[0146] Tables 2 and 3 show that the pressure-sensitive adhesive sheets of the examples obtained from curable compositions containing a predetermined phosphite ester compound and satisfying A × B ≧ 0.5 have excellent performance in suppressing sulfurization, and also have a small resistance change rate and excellent durability even in high-temperature, high-humidity environments. Furthermore, the pressure-sensitive adhesive sheets obtained in the examples have small initial values ​​for haze and b* value, which indicates that they also have excellent optical properties. It was also found that by appropriately selecting the phosphite ester compound, their excellent optical properties are less likely to deteriorate even when placed in high-temperature, high-humidity environments.

[0147]

[0148]

Claims

1. A curable composition used to prevent the sulfidation of metals, comprising a base agent and a phosphite ester compound, wherein the base agent is at least one selected from the group consisting of acrylic polymers and polymerizable monomers, and the phosphite ester compound has two or less phenyl moieties bonded to phosphite moieties, and the sulfidation-preventing curable composition satisfies the following formula (1): A×B≧0.5 (1), where A parts by mass is the content of the phosphite ester compound per 100 parts by mass of the base agent and B is the number of phosphite moieties in the phosphite ester compound.

2. The sulfuration-preventing curable composition according to claim 1, wherein the metal is silver or copper and the metal layer has a mesh structure.

3. A pressure-sensitive adhesive sheet comprising a cured product of the curable composition for preventing sulfidation according to claim 1 or 2.

4. A coating comprising a cured product of the curable composition for preventing sulfidation according to claim 1 or 2.

5. A component for a display device comprising a touch sensor film, wherein the touch sensor film comprises a laminate including the adhesive sheet according to claim 3 and a metal layer having a mesh structure, the adhesive sheet being attached to at least one side of the metal layer, and the metal layer being silver or copper.

6. A component for a display device comprising a touch sensor film, wherein the touch sensor film comprises a laminate including the coating according to claim 4 and a metal layer having a mesh structure, the coating being formed on at least one side of the metal layer, and the metal layer being silver or copper.

7. A display device comprising the member for a display device according to claim 5.

8. A display device comprising the member for a display device according to claim 6.

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