Thin film polymer laminated capacitor and manufacturing method therefor

Abstract

The present invention pertains to a thin film polymer laminated capacitor having a structure in which a resin thin film layer and an internal electrode metal layer are alternately laminated. The resin thin film layer has a high molecular weight structure obtained through polymerization of a first monomer which is a polyfunctional monomer and a second monomer which is a monofunctional monomer. The first monomer and the second monomer satisfy at least one of conditions (a) and (b).　(a) The HLB value H2 of the second monomer is less than the HLB value H1 of the first monomer. (b) By using the following manufacturing method (1), when a first polymer member formed by using only the first monomer as the monomer and a second polymer member formed by using only the second monomer as the monomer are manufactured, and the water absorption rate of each of the polymer members is measured after being left still at 40℃ for 40 hours at 95%-relative humidity, the water absorption rate of the second polymer member is lower than the water absorption rate of the first polymer member. Here, the manufacturing method (1) comprises: providing the first monomer or the second monomer as a test monomer; obtaining a mixture by mixing a photoinitiator at a proportion of 0.2±0.01 mol with respect to 100 mol of the test monomer; pouring the mixture in a round plate; and creating a disc shaped polymer member having a dimension of diameter 30 mm × depth 1 mm, by irradiating, with UV, the mixture poured in the round plate in a nitrogen atmosphere at 120 W and from a distance of 250 mm until progress of polymerization stops.

Description

Thin film polymer laminated capacitor and its manufacturing method

[0001] The present invention relates to a thin film polymer multilayer capacitor and a method for manufacturing the same.

[0002] 2. Description of the Related Art A capacitor having a structure in which dielectric layers containing resin and electrode layers containing metal are alternately laminated is known.

[0003] Patent Document 1 describes a thin-film polymer laminate film capacitor and a method for manufacturing the same, which includes alternately repeating, on a rotating drum, the steps of forming a resin thin film layer by vapor-depositing a monomer in a vacuum chamber and then curing the monomer layer by irradiating the monomer layer with an electron beam, and forming a metal thin film layer by vapor-depositing a metal material, thereby manufacturing a laminate in which resin thin film layers and metal thin film layers are alternately stacked on a rotating drum.

[0004] Patent Document 2 discloses a capacitor having two electrodes separated by a dielectric member, and states that the dielectric member comprises a multifunctional acrylate polymer having a specific chemical structure.

[0005] International Publication No. 2015 / 118693 Japanese Patent Application Laid-Open No. 60-157106

[0006] Conventional thin-film polymer multilayer capacitors have sometimes lacked sufficient performance in terms of durability. In particular, conventional thin-film polymer multilayer capacitors formed using polyfunctional monomers have sometimes lacked sufficient durability. Furthermore, it has been difficult to provide conventional capacitors that have both good electrical properties and sufficient durability.

[0007] An object of the present invention is to provide a thin-film polymer multilayer capacitor that has the electrical performance required for a thin-film polymer multilayer capacitor and also has improved durability.

[0008] The above problems can be solved by the following aspects of the present invention: <Aspect 1> A thin-film polymer multilayer capacitor having a structure in which resin thin film layers and internal electrode metal layers are alternately laminated, wherein the resin thin film layers have a polymer structure obtained by polymerizing a first monomer that is a polyfunctional monomer and a second monomer that is a monofunctional monomer, and the first monomer and the second monomer satisfy at least one of the following conditions (a) and (b): (a) the HLB value H of the second monomer is less than 100%; ２ is the HLB value H of the first monomer １ (b) producing a first polymer member formed using only the first monomer as a monomer and a second polymer member formed using only the second monomer as a monomer according to the following production method (1), and measuring the water absorption of each polymer member after leaving it to stand for 40 hours under conditions of 40°C and 95% relative humidity, and finding that the water absorption of the second polymer member is smaller than the water absorption of the first polymer member, wherein the production method (1) comprises: providing the first monomer or the second monomer as a test monomer; mixing a photoinitiator in a ratio of 0.2±0.01 mol per 100 mol of the test monomer to obtain a mixture; pouring the mixture into a round dish; and irradiating the mixture poured into the round dish with UV light in a nitrogen atmosphere under conditions of 120 W and a distance of 250 mm until polymerization stops, thereby producing a disk-shaped polymer member having dimensions of 30 mm in diameter and 1 mm in depth. <Aspect 2> The HLB value H of the first monomer １ and the HLB value H of the second monomer ２ The difference between １ -H ２ The capacitor according to aspect 1, wherein the difference (H １ -H ２ The capacitor according to aspect 2, wherein the HLB value H of the first monomer is 0.5 or more. １ is in the range of 3.0 to 5.0, and the HLB value H of the second monomer is ２is in the range of 2.0 to 4.0. <Aspect 5> The capacitor according to any one of Aspects 1 to 4, wherein the molar ratio of the first monomer to the second monomer is 10:90 to 90:10. <Aspect 6> The capacitor according to any one of Aspects 1 to 5, wherein at least one of the first monomer and the second monomer has an acrylate group or a methacrylate group, or at least one of the first monomer and the second monomer includes a monomer having an acrylate group or a methacrylate group. <Aspect 7> The capacitor according to Aspect 6, wherein both the first monomer and the second monomer have an acrylate group or a methacrylate group, or both the first monomer and the second monomer include a monomer having an acrylate group or a methacrylate group. <Aspect 8> The capacitor according to any one of Aspects 1 to 7, wherein the first monomer is a bifunctional monomer. Aspect 9 The capacitor according to any one of Aspects 1 to 8, wherein the first monomer is tricyclodecane dimethanol diacrylate or tricyclodecane dimethanol dimethacrylate, or the first monomer includes tricyclodecane dimethanol diacrylate or tricyclodecane dimethanol dimethacrylate; and / or the second monomer is 2-(biphenyl-2-yloxy)-ethyl acrylate or 4-phenylbenzyl acrylate, or the second monomer includes 2-(biphenyl-2-yloxy)-ethyl acrylate or 4-phenylbenzyl acrylate.Aspect 10 The capacitor according to any one of Aspects 1 to 9, wherein a third polymer member produced according to the following production method (2) has a water absorption rate of 0.8% or less when left to stand for 40 hours under conditions of 40°C and 95% relative humidity, wherein the production method (2) comprises: providing the first monomer and the second monomer; mixing the first monomer and the second monomer in the same molar ratio as in the resin thin film layer to obtain a monomer mixture; mixing a photoinitiator in a ratio of 0.2±0.01 mol per 100 mol of the monomer mixture to obtain a mixture; pouring the mixture into a round plate; and irradiating the mixture poured into the round plate with UV light in a nitrogen atmosphere under conditions of 120 W and a distance of 250 mm until polymerization no longer proceeds, thereby producing a disk-shaped polymer member having dimensions of 30 mm in diameter and 1 mm in depth. <Aspect 11> The capacitor according to any one of Aspects 1 to 10, wherein the capacitor has a relative dielectric constant of 2.0 or greater when measured at 25° C. and 1 kHz, and a tan δ of less than 1.0% when measured at 25° C. and 1 kHz. <Aspect 12> A method for producing a thin-film polymer multilayer capacitor having a structure in which resin thin film layers and internal electrode metal layers are alternately laminated, the method comprising: forming the resin thin film layers by curing a monomer layer containing a first monomer that is a polyfunctional monomer and a second monomer that is a monofunctional monomer, the first monomer and the second monomer satisfying at least one of the following conditions (a) and (b): (a) the HLB value H of the second monomer is 2.0 or greater; ２ is the HLB value H of the first monomer １(b) producing a first polymer member formed using only the first monomer as a monomer and a second polymer member formed using only the second monomer as a monomer according to the following production method (1), and measuring the water absorption of each polymer member after leaving it to stand for 40 hours under conditions of 40°C and 95% relative humidity, and finding that the water absorption of the second polymer member is smaller than the water absorption of the first polymer member, wherein the production method (1) comprises: providing the first monomer or the second monomer as a test monomer; mixing a photoinitiator in a ratio of 0.2±0.01 mol per 100 mol of the test monomer to obtain a mixture; pouring the mixture into a round dish; and irradiating the mixture poured into the round dish with UV light in a nitrogen atmosphere under conditions of 120 W and a distance of 250 mm until polymerization stops, thereby producing a disk-shaped polymer member having dimensions of 30 mm in diameter and 1 mm in depth.

[0009] According to the present invention, it is possible to provide a thin-film polymer multilayer capacitor that has the electrical performance required for a thin-film polymer multilayer capacitor and also has improved durability.

[0010] Fig. 1 is a schematic perspective view of a thin film polymer multilayer capacitor 1. Fig. 2 is a graph showing the results of measuring the water absorption rate of the capacitors according to Example 1 and Comparative Example 1.

[0011] <<Thin Film Polymer Multilayer Capacitor>> The thin film polymer multilayer capacitor according to the present disclosure has a structure in which resin thin film layers and internal electrode metal layers are alternately laminated, the resin thin film layers have a polymer structure obtained by polymerizing a first monomer that is a polyfunctional monomer and a second monomer that is a monofunctional monomer, and the first monomer and the second monomer satisfy at least one of the following conditions (a) and (b): (a) the HLB value H of the second monomer is less than or equal to 100%; ２ is the HLB value H of the first monomer １(b) producing a first polymer member formed using only a first monomer as a monomer, and a second polymer member formed using only a second monomer as a monomer according to the following production method (1), and measuring the water absorption of each polymer member after leaving it to stand for 40 hours under conditions of 40°C and 95% relative humidity, the water absorption of the second polymer member is found to be smaller than the water absorption of the first polymer member, wherein the production method (1) comprises: providing the first monomer or the second monomer as a test monomer; mixing a photoinitiator in a ratio of 0.2±0.01 mol per 100 mol of the test monomer to obtain a mixture; pouring the mixture into a round dish; and irradiating the mixture poured into the round dish with UV light in a nitrogen atmosphere under conditions of 120 W and a distance of 250 mm until polymerization stops, thereby producing a disk-shaped polymer member having dimensions of 30 mm in diameter and 1 mm in depth.

[0012] Conventional capacitors have not always been able to achieve good durability. In particular, conventional capacitors using polymers formed from polyfunctional monomers have not always been able to achieve good durability, despite the fact that they have a polymer structure in the resin thin film layer with a relatively high degree of cross-linking.

[0013] In contrast to this, the present invention can provide a thin film polymer multilayer capacitor that has the necessary performance as a thin film polymer multilayer capacitor and also has improved durability.

[0014] More specifically, in the capacitor of the present invention that satisfies the above condition (a), the resin thin film layer is formed using not only a polyfunctional monomer but also a monofunctional monomer having a relatively low HLB value. Without intending to be limited by theory, in this case, it is believed that the polyfunctional monomer ensures a sufficient degree of cross-linking of the polymer structure in the resin thin film layer, and the polymer structural unit derived from the monofunctional monomer having a relatively low HLB value reduces the water absorption of the resin thin film layer, resulting in excellent durability.

[0015] Furthermore, in the capacitor of the present invention that satisfies the above condition (b), the resin thin film layer is formed using not only a polyfunctional monomer but also a monofunctional monomer that forms a polymer with relatively low water absorption. Without intending to be limited by theory, in this case, it is believed that the polyfunctional monomer ensures a sufficient degree of cross-linking of the polymer structure in the resin thin film layer, and the polymer structural unit derived from the monofunctional monomer reduces the water absorption of the resin thin film layer, resulting in excellent durability.

[0016] Furthermore, without intending to be limited by theory, it is believed that the inclusion of a monofunctional monomer suppresses cure shrinkage of the resin thin film layer and suppresses the generation of internal stress compared to the use of only a polyfunctional monomer, thereby reducing warping and cracking and preventing or suppressing delamination in the capacitor. In this case, it is believed that the intrusion of moisture into cracked or delaminated areas is suppressed, further suppressing the water absorption rate of the capacitor.

[0017] The methods according to the present disclosure are described in more detail below.

[0018] <First Monomer and Second Monomer> The resin thin film layer has a polymer structure obtained by polymerizing a first monomer which is a polyfunctional monomer and a second monomer which is a monofunctional monomer. Preferably, the proportion of monomer units derived from the first monomer and monomer units derived from the second monomer among all monomer units constituting the polymer structure of the resin thin film layer is 80% or more, 85% or more, 90% or more, or 95% or more, in terms of molar ratio, and particularly preferably 100%.

[0019] A polyfunctional monomer has multiple (particularly two) polymerizable functional groups in one molecule, whereas a monofunctional monomer has one polymerizable functional group in one molecule.

[0020] Examples of the polymerizable functional group include a vinyl group (particularly an acrylic group, a methacrylic group, an acrylate group, or a methacrylate group), an acrylonitrile group, and an epoxy group. Preferably, the polyfunctional monomer and / or the monofunctional monomer has at least either an acrylate group or a methacrylate group. Most preferably, both the polyfunctional monomer and the monofunctional monomer have an acrylate group. Note that the monomer having an acrylate group is an acrylate monomer, and the monomer having a methacrylate group is a methacrylate monomer.

[0021] The polyfunctional monomer and the monofunctional monomer can be polymerized via the polymerizable functional group under conditions such as electron beam irradiation to form a polymer.

[0022] The ratio of the first monomer to the second monomer, that is, the ratio of the polyfunctional monomer to the monofunctional monomer, can be set appropriately depending on the desired characteristics of the capacitor, etc.

[0023] The molar ratio of the first monomer to the second monomer is preferably 10:90 to 90:10, more preferably 20:80 to 80:20, 30:70 to 70:30, 40:60 to 60:40, or 45:55 to 55:45.

[0024] In other words, the number of moles of the second monomer relative to the total number of moles of the first monomer and the second monomer is preferably 10 to 90%, 20 to 80%, 30 to 70%, 40 to 60%, or 45 to 55%.

[0025] When the ratio of the first monomer to the second monomer is within the above range, a capacitor having good electrical properties and particularly excellent durability can be provided.

[0026] (Multifunctional Monomer) The multifunctional monomer is, in particular, a bifunctional monomer. The multifunctional monomer preferably has an acrylate group or a methacrylate group. The multifunctional monomer most preferably has an acrylate group. In another embodiment, the multifunctional monomer preferably comprises a monomer having an acrylate group or a methacrylate group, or consists of a monomer having an acrylate group or a methacrylate group. The multifunctional monomer most preferably comprises a monomer having an acrylate group, or consists of a monomer having an acrylate group.

[0027] In one embodiment according to the present disclosure, the polyfunctional monomer can have a chemical structure represented by the following general formula (1):

[0028]

[0029] In formula (1), R １ is a group containing 1 to 20 carbon atoms; R ２ is H or CH ３ and n is 2 to 4.

[0030] In formula (1), n ​​is preferably 2 to 3, more preferably n=2.

[0031] In formula (1), R １ preferably contains 3 to 20, more preferably 6 to 20, and even more preferably 8 to 20 carbon atoms.

[0032] R in formula (1) １ may contain an oxygen atom. In this case, R １ can contain 1 to 20, 1 to 10, 1 to 5, 1 to 3, or 1 to 2 oxygen atoms, or can contain 1 oxygen atom.

[0033] R in formula (1) １ In particular, R may contain an ether bond. １ can contain 1 to 20, 1 to 10, 1 to 5, 1 to 3, or 1 to 2 ether linkages, or can contain 1 ether linkage.

[0034] Preferably, R in formula (1) １consists of carbon and hydrogen atoms, and optionally oxygen atoms.

[0035] In formula (1), R １ can contain aliphatic (linear or branched) moieties, alicyclic moieties, and / or aromatic moieties.

[0036] R in formula (1) １ When the alicyclic moiety is included, the bulkiness of the molecule increases, which increases the molar volume and can have the effect of lowering the tan δ of the capacitor. Furthermore, due to the bulkiness and rigidity, the micro-Brownian motion of the main chain segments in the three-dimensional network structure of the polymer caused by temperature increase can be inhibited, resulting in a capacitor with a relatively high glass transition temperature and excellent heat resistance. Furthermore, since the cure shrinkage of the resin thin film layer is relatively suppressed, the interlayer adhesion of the capacitor can be further improved.

[0037] R in formula (1) １ When R contains an aromatic moiety, it has a π-electron conjugated system, and therefore the polarization due to the orientation of the dipole is larger than that of a simple alkyl skeleton, and a relatively large dielectric constant can be obtained. １ When the alicyclic moiety contains a bulky structure such as a biphenyl structure, it can have the effect of lowering the tan δ of the capacitor, as described above with respect to the alicyclic moiety. Furthermore, since the cure shrinkage of the resin thin film layer is relatively suppressed, the interlayer adhesion of the capacitor can be further improved.

[0038] In formula (1), R １ It is preferable that the polymer does not contain unsaturated bonds. By not containing unsaturated bonds, an increase in tan δ of the capacitor can be suppressed in some cases.

[0039] Examples of the compound structures M1 to M6 of the polyfunctional monomer that can be used in the present invention are shown below.

[0040]

[0041] In the chemical formulae M3 and M4, n may be 1 to 20, preferably 5 to 18, more preferably 8 to 15, and even more preferably 9 to 12.

[0042] In the chemical formulae M5 and M6, n may be 1 to 20, preferably 1 to 10, more preferably 2 to 6, and even more preferably 3 to 4.

[0043] Examples of preferred compound structures of polyfunctional monomers are shown below.

[0044]

[0045] Particularly preferred polyfunctional monomers include tricyclodecane dimethanol diacrylate, tricyclodecane dimethanol dimethacrylate, dodecane-1,12-diyl dimethacrylate, dodecane-1,12-diyl diacrylate, and α,α'-[propane-2,2-diylbis-(4,1-phenylene)]bis[ω-(acryloyloxy)poly(oxyethylene)].

[0046] (Monofunctional Monomer) The monofunctional monomer preferably has an acrylate group or a methacrylate group. The monofunctional monomer most preferably has an acrylate group. In another embodiment, the monofunctional monomer preferably comprises a monomer having an acrylate group or a methacrylate group, or consists of a monomer having an acrylate group or a methacrylate group. The monofunctional monomer most preferably comprises a monomer having an acrylate group, or consists of a monomer having an acrylate group.

[0047] In one embodiment according to the present disclosure, the monofunctional monomer can have a chemical structure represented by the following general formula (2):

[0048]

[0049] In formula (2), R ３ is a group containing 1 to 20 carbon atoms; R ２ is H or CH ３ is.

[0050] R in formula (2) ２ is preferably H.

[0051] R in formula (2) ３preferably contains 3 to 20, more preferably 6 to 20, and even more preferably 8 to 20 carbon atoms.

[0052] R in formula (2) ３ may contain an oxygen atom. In this case, R ３ can contain 1 to 20, 1 to 10, 1 to 5, 1 to 3, 1 to 2, or 1 oxygen atom.

[0053] R in formula (2) ３ In particular, R may contain an ether bond. ３ can contain 1 to 20, 1 to 10, 1 to 5, 1 to 3, 1 to 2, or 1 ether linkages.

[0054] Preferably, R in formula (2) ３ consists of carbon and hydrogen atoms, and optionally oxygen atoms.

[0055] In formula (2), R ３ can contain aliphatic (linear or branched) moieties, alicyclic moieties, and / or aromatic moieties.

[0056] R in formula (2) ３ When the alicyclic moiety is included, the bulkiness of the molecule increases, which increases the molar volume and can have the effect of lowering the tan δ of the capacitor. Furthermore, due to the bulkiness and rigidity, the micro-Brownian motion of the main chain segments in the three-dimensional network structure of the polymer caused by temperature increase can be inhibited, resulting in a capacitor with a relatively high glass transition temperature and excellent heat resistance. Furthermore, since the cure shrinkage of the resin thin film layer is relatively suppressed, the interlayer adhesion of the capacitor can be further improved.

[0057] R in formula (2) ３ When R contains an aromatic moiety, it has a π-electron conjugated system, and therefore the polarization due to the orientation of the dipole is larger than that of a simple alkyl skeleton, and a relatively large dielectric constant can be obtained. ３ When the alicyclic moiety contains a bulky structure such as a biphenyl structure, it can have the effect of lowering the tan δ of the capacitor, as described above with respect to the alicyclic moiety. Furthermore, since the cure shrinkage of the resin thin film layer is relatively suppressed, the interlayer adhesion of the capacitor can be further improved.

[0058] R ３ Particularly preferably, has a biphenyl structure.

[0059] In formula (2), R ３ It is preferable that the polymer does not contain unsaturated bonds. By not containing unsaturated bonds, an increase in tan δ of the capacitor can be suppressed in some cases.

[0060] Examples of the compound structures of the monofunctional monomers that can be used in the present invention, S1 to S8 and S'1 to S'4, are shown below.

[0061]

[0062] In the chemical formulae S1 and S2 and S'1 and S'2, n may be 0 to 20, preferably 1 to 10, more preferably 1 to 5, even more preferably 1 to 3 or 1 to 2, and most preferably n=1.

[0063] In the chemical formulas S5 and S6, n may be 1 to 20, preferably 5 to 18, and more preferably 12 to 16.

[0064] In the chemical formulae S7 and S8, n may be 1 to 20, preferably 10 to 20, more preferably 12 to 18, and even more preferably 14 to 16.

[0065] Examples of preferred compound structures of monofunctional monomers are shown below.

[0066]

[0067] Particularly preferred monofunctional monomers include 2-(biphenyl-2-yloxy)-ethyl acrylate, 4-phenylbenzyl acrylate, 2-[(tricyclo[5.2.1.0(2,6)]dec-4-en-9-yl)oxy]ethyl acrylate, and 2-[(tricyclo[5.2.1.0(2,6)]dec-4-en-9-yl)oxy]ethyl methacrylate.

[0068] Particularly preferred combinations of the first monomer and the second monomer include the following (1) and (2): (1) a combination of tricyclodecane dimethanol diacrylate and 2-(biphenyl-2-yloxy)-ethyl acrylate; (2) a combination of tricyclodecane dimethanol diacrylate and 4-phenylbenzyl acrylate.

[0069] In one embodiment of the present invention, at least one of the first monomer and the second monomer has an acrylate group or a methacrylate group (i.e., is an acrylate monomer or a methacrylate monomer), or at least one of the first monomer and the second monomer comprises a monomer having an acrylate group or a methacrylate group (i.e., an acrylate monomer or a methacrylate monomer).

[0070] In one embodiment of the present invention, the first monomer and the second monomer both have an acrylate group or a methacrylate group (i.e., are acrylate or methacrylate monomers), or the first monomer and the second monomer both comprise a monomer having an acrylate group or a methacrylate group (i.e., an acrylate or methacrylate monomer).

[0071] In one embodiment of the present invention, the first monomer is or comprises tricyclodecane dimethanol diacrylate or tricyclodecane dimethanol dimethacrylate, and / or the second monomer is or comprises 2-(biphenyl-2-yloxy)-ethyl acrylate or 4-phenylbenzyl acrylate.

[0072] <HLB Value> In one embodiment of the present disclosure, the capacitor according to the present invention satisfies the above condition (a). That is, the HLB value H of the second monomer, which is a monofunctional monomer, ２ is the HLB value H of the first monomer which is a polyfunctional monomer. １ is smaller than.

[0073] The HLB value is an index that represents the degree of affinity for water and oil, and is calculated based on the type of functional group that constitutes the monomer. The higher the HLB value, the more hydrophilic the monomer tends to be. The HLB value can be calculated according to the Davis method.

[0074] Preferably, the HLB value of the first monomer is H １ and the HLB value H of the second monomer ２ The difference between １ -H ２ ) is 0.1 or more. １ -H ２ ) is more preferably 0.2 or more, 0.3 or more, 0.4 or more, or 0.5 or more, and / or 3.0 or less, 2.5 or less, 2.0 or less, 1.9 or less, 1.8 or less, 1.7 or less, 1.6 or less, 1.5 or less, 1.4 or less, 1.3 or less, or 1.2 or less.

[0075] Preferably, the HLB value of the first monomer is H １ is in the range of 3.0 to 5.0. This range is more preferably 3.1 or more, 3.2 or more, 3.3 or more, 3.4 or more, 3.5 or more, 3.6 or more, 3.7 or more, 3.8 or more, 3.9 or more, or 4.0 or more, and / or 4.9 or less, 4.8 or less, 4.7 or less, 4.6 or less, 4.5 or less, 4.4 or less, or 4.3 or less.

[0076] Also, preferably, the HLB value H of the second monomer is ２ is in the range of 2.0 to 4.0. This range is more preferably 2.1 or more, 2.2 or more, 2.3 or more, 2.4 or more, 2.5 or more, 2.6 or more, 2.7 or more, 2.8 or more, 2.9 or more, or 3.0 or more, and / or 3.9 or less, 3.8 or less, 3.7 or less, 3.6 or less, 3.5 or less, 3.4 or less, 3.3 or less, or 3.2 or less.

[0077] The HLB value H of the first monomer １ , and the HLB value H of the second monomer ２ can be calculated based on the Davis method.

[0078] As examples, the HLB values ​​calculated based on the Davis method for some representative polyfunctional and monofunctional monomers are listed in Table 1 below.

[0079]

[0080] (Calculation Method of HLB Value by Davis Method) The HLB value can be calculated according to the Davis method using the following formula (A): HLB value=7+Σ(number of hydrophilic groups)+Σ(number of lipophilic groups) (A)

[0081] The number of main hydrophilic groups is as follows: Ester group (-COO-) 2.4 Hydroxyl group (-OH) 1.9 Ether group (-O-) 1.3 (-CH ２ CH ２ O-) 0.33

[0082] The main lipophilic groups are as follows: Alkanes (-CH ２ -) -0.475 Methyl group (-CH ３ ) -0.475 Alkene (-CH=) -0.475 (-CH ２ CH (CH ３ )O-) -0.15

[0083] For example, in the case of tricyclodecane dimethanol dimethacrylate, the HLB value is calculated as follows based on the above number of groups: 2 ester groups, 12 alkanes, 2 x 2 alkenes, and 2 methyl groups.

[0084] The cyclic structures in the molecular structure of tricyclodecane dimethanol dimethacrylate and the methylene groups directly bonded thereto are all alkanes (the cyclic structure is composed of a total of 10 alkanes).

[0085] For example, in the case of 2-(biphenyl-2-yloxy)-ethyl acrylate, the following is obtained: 1 ester group 2 alkene + 6 × 2 (-CH ２ CH ２ From the above bases, the HLB value is calculated as follows: HLB value = 3.08 (approximately 3.1)

[0086] It is assumed that each of the two benzene rings in the molecular structure of 2-(biphenyl-2-yloxy)-ethyl acrylate is composed of six alkenes.

[0087] <Water Absorption Rate> In another embodiment of the present disclosure, the capacitor according to the present invention satisfies the above-mentioned condition (b). That is, when a first polymer member formed using only a first monomer as a monomer and a second polymer member formed using only a second monomer as a monomer are produced according to the above-mentioned production method (1), and the water absorption rates of each polymer member are measured after leaving them to stand for 40 hours under conditions of 40°C and 95% relative humidity, the water absorption rate of the second polymer member is lower than the water absorption rate of the first polymer member.

[0088] The difference between the water absorption rate (%) of the second polymer component and the water absorption rate (%) of the first polymer component may be 0.05 or more. This difference is preferably 0.1 or more, 0.2 or more, or 0.3 or more. The upper limit of this difference is not particularly limited, but may be, for example, 2.0 or less.

[0089] The water absorption of the first polymer component may be between 0.5% and 2.0%, and is preferably 0.7% or more, 0.8% or more, 0.9% or more, and / or 1.8% or less, 1.6% or less, 1.4% or less, or 1.2% or less.

[0090] The water absorption of the second polymer component may be between 0.1% and 1.0%, and the water absorption of the first polymer component is preferably 0.2% or more, 0.3% or more, 0.4% or more, and / or 1.0% or less, 0.9% or less, 0.8% or less, or 0.7% or less.

[0091] The water absorption rates of the first polymer member and the second polymer member can be calculated from the weight change rate of the polymer member when a moisture absorption test is conducted in which the polymer member to be measured is left standing for 40 hours under conditions of 40°C and 95% relative humidity.

[0092] That is, the weight change rate (%) can be calculated from the weight of the polymer member before the moisture absorption test and the weight of the polymer member immediately after the moisture absorption test, and this can be used as the water absorption rate. In particular, the weight change rate (%) can be calculated according to the following formula: Weight change rate (%) = 100 × (weight after the moisture absorption test - weight before the moisture absorption test) / weight before the moisture absorption test.

[0093] <Method for Manufacturing First and Second Polymer Members> The first polymer member and the second polymer member for measuring the water absorption rate are manufactured according to the manufacturing method (1).

[0094] The manufacturing method (1) comprises: providing a first monomer or a second monomer as a test monomer; mixing a photoinitiator in a ratio of 0.2±0.01 moles per 100 moles of the test monomer to obtain a mixture; pouring the mixture into a round dish; and irradiating the mixture poured into the round dish with UV light in a nitrogen atmosphere under conditions of 120 W and a distance of 250 mm until polymerization stops, thereby producing a disk-shaped polymer member having dimensions of 30 mm in diameter and 1 mm in depth.

[0095] For the first or second monomer provided as the test monomer, the above description can be referred to.

[0096] The photoinitiator can be appropriately selected depending on the type of test monomer. A specific example of the photoinitiator is 2-benzyl-2-dimethylamino-4'morpholinobutyrophenone. The test monomer and the photoinitiator can be mixed according to a known method.

[0097] The round dish has dimensions such that a disk-shaped polymer member having dimensions of 30 mm in diameter and 1 mm in depth is produced when the mixture placed therein is polymerized by UV irradiation. Specifically, for example, the round dish may have a planar area of ​​30 mm in inner diameter and a depth of 1 to 5 cm, and the mixture can be poured into this round dish to a height of 1 mm.

[0098] UV irradiation is performed to drive the polymerization of the test monomers and is performed at an intensity of 120 W and a distance of 250 mm from the sample.

[0099] The UV irradiation time is determined depending on the type of test monomer, and is particularly performed so that the polymerization of the test monomer (i.e., the curing of the mixture) progresses sufficiently, and is continued until further UV irradiation no longer causes polymerization. Those skilled in the art can determine such UV irradiation time depending on the type of test monomer. For example, if the test monomer is an acrylate monomer (a monomer having an acrylate group), UV irradiation can be performed for 60 seconds. Also, for example, if the test monomer is a methacrylate monomer (a monomer having a methacrylate group), UV irradiation can be performed for 360 seconds. If the test monomer has both an acrylate group and a methacrylate group, UV irradiation can be performed for 360 seconds.

[0100] <Thin Film Polymer Multilayer Capacitor> The thin film polymer multilayer capacitor according to the present disclosure has a structure in which thin resin layers and internal electrode metal layers are alternately laminated.

[0101] 1 is a perspective schematic diagram of a thin-film polymer multilayer capacitor 1. The thin-film polymer multilayer capacitor 1 has a laminate 2 in which resin thin film layers and metal thin film layers (internal electrode metal layers) are alternately laminated, and two external electrodes 3 and 4 are attached to this laminate 2.

[0102] The thin film polymer multilayer capacitor can have 10 to 10,000 layers, 50 to 5000 layers, or 100 to 2,000 layers.

[0103] The resin thin film layer may have a thickness of 10 nm to 3000 nm, and preferably has a thickness of 100 to 1500 nm.

[0104] The metal material constituting the internal electrode metal layer may be at least one selected from the group consisting of Al, Cu, Zn, Sn, Au, Ag, Pt, and combinations thereof.

[0105] The internal electrode metal layer may have a thickness of 1 nm to 100 nm, preferably 10 to 40 nm, and the metal thin film layer preferably has a deposition resistance of 1 to 50 Ω / □, 5 to 40 Ω / □, or 5 to 30 Ω / □.

[0106] (Dielectric Constant) Preferably, the capacitor according to the present disclosure has a dielectric constant of 2.0 or more when measured at 25° C. and 1 kHz. This dielectric constant is more preferably 2.1 or more, 2.2 or more, 2.3 or more, or 2.5 or more. The upper limit of this dielectric constant is not particularly limited, but may be 5.0 or less.

[0107] The relative dielectric constant at 25° C. and 1 kHz can be calculated based on the capacitance measured using an LCR meter, as well as the electrode area and the dielectric thickness.

[0108] (tan δ) Preferably, the capacitor according to the present disclosure has a tan δ (dielectric loss tangent or loss factor) of less than 1.0% when measured at 25°C and 1 kHz. This tan δ is more preferably 0.9% or less, 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, 0.4% or less, 0.3% or less, 0.2% or less, or 0.1% or less. The lower limit of this tan δ is not particularly limited, but may be 0.05% or more.

[0109] Preferably, the capacitor according to the present disclosure has a tan δ of less than 0.01 when measured at 25° C. and 1 kHz. This tan δ is more preferably 0.009 or less, 0.008 or less, 0.007 or less, 0.006 or less, 0.005 or less, 0.004 or less, 0.003 or less, 0.002 or less, or 0.001 or less. The lower limit of this tan δ is not particularly limited, but may be 0.0005 or more.

[0110] Tan δ at 25° C. and 1 kHz can be measured using an LCR meter.

[0111] (Water absorption rate of capacitor) Preferably, with respect to a capacitor, a third polymer member produced according to the following production method (2) has a water absorption rate of 0.8% or less when left to stand for 40 hours under conditions of 40°C and 95% relative humidity.

[0112] The water absorption rate of the third polymer member is preferably 0.7% or less, 0.6% or less, 0.5% or less, or 0.4% or less. The lower limit of the water absorption rate of the third polymer member is not particularly limited, but may be, for example, 0.01% or more.

[0113] (Production method (2): Production method for third polymer member) Production method (2) for producing the third polymer member comprises: providing a first monomer and a second monomer; mixing the first monomer and the second monomer in the same molar ratio as in the resin thin film layer to obtain a monomer mixture; mixing a photoinitiator in a ratio of 0.2±0.01 mol per 100 mol of the monomer mixture to obtain a mixture; pouring the mixture into a round dish; and irradiating the mixture poured into the round dish with UV light in a nitrogen atmosphere under conditions of 120 W and a distance of 250 mm until polymerization stops, thereby producing a disk-shaped polymer member having dimensions of 30 mm in diameter and 1 mm in depth.

[0114] For details of the manufacturing method (2) for manufacturing the third polymer member, reference can be made to the above description of the manufacturing method (1).

[0115] <Method for Manufacturing Capacitor> There are no particular limitations on the method for manufacturing the thin film polymer multilayer capacitor according to the present disclosure.

[0116] For example, the thin film polymer laminate capacitor according to the present disclosure can be manufactured by a method including alternately repeating, on a rotating drum in a vacuum chamber, a step of forming a resin thin film layer and a step of forming a metal thin film layer by vapor deposition of a metal material, thereby manufacturing a laminate in which resin thin film layers and metal thin film layers are alternately laminated on the rotating drum.

[0117] As a method for alternately laminating resin thin film layers and metal thin film layers on a rotating drum in this manner, a known method can be used, for example, the method described in International Publication No. 2015 / 118693.

[0118] The laminate formed on the rotating drum can be removed from the rotating drum and flattened by pressing under heat. The flattened laminate can then be cut into sticks, after which external electrodes can be formed, and the resulting sticks can be further cut into chips to obtain thin film polymer multilayer capacitors.

[0119] Preferably, the thin film polymer multilayer capacitor according to the present disclosure can be manufactured according to the following manufacturing method according to the present disclosure.

[0120] (Method for manufacturing a capacitor according to the present invention) A method for manufacturing a thin film polymer multilayer capacitor having a structure in which resin thin film layers and internal electrode metal layers are alternately laminated, the method comprising: forming a resin thin film layer by curing a monomer layer containing a first monomer which is a polyfunctional monomer and a second monomer which is a monofunctional monomer, the first monomer and the second monomer satisfying at least one of the following conditions (a) and (b): (a) the HLB value H of the second monomer is less than 1000; ２ is the HLB value H of the first monomer １(b) producing a first polymer member formed using only a first monomer as a monomer, and a second polymer member formed using only a second monomer as a monomer according to the following production method (1), and measuring the water absorption of each polymer member after leaving it to stand for 40 hours under conditions of 40°C and 95% relative humidity, the water absorption of the second polymer member is found to be smaller than the water absorption of the first polymer member, wherein the production method (1) comprises: providing the first monomer or the second monomer as a test monomer; mixing a photoinitiator in a ratio of 0.2±0.01 mol per 100 mol of the test monomer to obtain a mixture; pouring the mixture into a round dish; and irradiating the mixture poured into the round dish with UV light in a nitrogen atmosphere under conditions of 120 W and a distance of 250 mm until polymerization stops, thereby producing a disk-shaped polymer member having dimensions of 30 mm in diameter and 1 mm in depth.

[0121] For details of the manufacturing method according to the present disclosure, reference can be made to the above description of the capacitor according to the present disclosure, particularly with respect to manufacturing method (1), condition (a), and condition (b), reference can be made to the above description of the capacitor according to the present disclosure.

[0122] The "curing treatment" when forming the resin thin film layer can be performed according to a known method, for example, according to the method described in WO 2015 / 118693. Specifically, for example, the curing treatment can be performed by depositing a monomer in a vacuum chamber to form a monomer layer, and then irradiating the monomer layer with an electron beam to cure the monomer layer.

[0123] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0124] Reference Examples 1 to 3 (Water Absorbency Test) In Reference Examples 1 to 3, the water absorbency of the monomers shown in Table 2 below was evaluated using polymer lumps (polymer members).

[0125] Reference Example 1 In Reference Example 1, a polymer member was produced using tricyclodecane dimethanol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: A-DCP), which is a bifunctional monomer, as a test monomer, as follows: providing tricyclodecane dimethanol diacrylate as a test monomer, mixing a photoinitiator (2-benzyl-2-dimethylamino-4'morpholinobutyrophenone, manufactured by Tokyo Chemical Industry Co., Ltd.) in a ratio of 0.2±0.01 mol with 100 mol of the test monomer to form a mixture, pouring the mixture into a round dish, and irradiating the mixture poured into the round dish with UV light in a nitrogen atmosphere under conditions of 120 W and a distance of 250 mm until polymerization no longer proceeded, thereby producing a disk-shaped polymer member having dimensions of 30 mm in diameter and 1 mm in depth.

[0126] Since the test monomer in Reference Example 1 was a monomer having an acrylate group, the mixture was irradiated with UV light for 60 seconds to allow polymerization (i.e., curing) to proceed sufficiently. Even if some defects were formed in the polymer, it was still used for water absorption evaluation.

[0127] The obtained polymer member was subjected to a moisture absorption test. Specifically, the polymer member was placed in a constant temperature and humidity chamber set at 40°C and 95% relative humidity and left to stand for 40 hours. The weight change rate before and after the moisture absorption test was measured and defined as the water absorption rate. The results are shown in Table 2 below.

[0128] <Reference Example 2> In Reference Example 2, a water absorption test of a polymer member was carried out in the same manner as in Reference Example 1, except that a monofunctional monomer, 2-(biphenyl-2-yloxy)-ethyl acrylate (product name: A-LEN-10, manufactured by Shin-Nakamura Chemical Co., Ltd.), was used as the test monomer instead of tricyclodecane dimethanol diacrylate. The results are shown in Table 2 below. The test monomer in Reference Example 2 was a monomer having an acrylate group.

[0129] In Reference Example 3, a water absorption test of the polymer member was carried out in the same manner as in Reference Example 1, except that a mixture of tricyclodecane dimethanol diacrylate and 2-(biphenyl-2-yloxy)-ethyl acrylate (molar ratio 50:50) was used as the test monomer instead of tricyclodecane dimethanol diacrylate. The results are shown in Table 2 below.

[0130]

[0131] As can be seen from Table 2, the polymer member formed from 2-(biphenyl-2-yloxy)-ethyl acrylate (Reference Example 2) exhibited a relatively low water absorption rate compared to the polymer member formed from tricyclodecane dimethanol diacrylate (Reference Example 1).

[0132] Furthermore, as can be seen in Table 2, the polymer member formed from a mixture of tricyclodecane dimethanol diacrylate and 2-(biphenyl-2-yloxy)-ethyl acrylate (Reference Example 3) exhibited relatively low water absorption compared to the polymer member formed from tricyclodecane dimethanol diacrylate alone (Reference Example 1).

[0133] These results indicate that by combining a multifunctional monomer that exhibits a relatively high water absorption rate as measured on a polymeric material with a monofunctional monomer that exhibits a relatively low water absorption rate as measured on a polymeric material, the water absorption rate of the resulting polymer can be reduced.

[0134] Table 2 also shows the HLB values ​​calculated for each monomer according to the Davis method. As can be seen from Table 2, when calculated according to the Davis method, the HLB value of the monofunctional monomer 2-(biphenyl-2-yloxy)-ethyl acrylate was 3.1, and the HLB value of the bifunctional monomer tricyclodecane dimethanol diacrylate was 4.2. In other words, 2-(biphenyl-2-yloxy)-ethyl acrylate has a lower HLB value than tricyclodecane dimethanol diacrylate. The results in Table 2 show a correlation between the HLB value of the monomer and the water absorption rate measured on the polymer member.

[0135] Example 1 and Comparative Example 1 In Example 1 and Comparative Example 1, capacitors having resin thin film layers formed from the monomers or monomer mixtures shown in Table 3 below were manufactured, and durability was evaluated. Example 1 (Manufacturing of thin film polymer laminate capacitor) A step of forming a resin thin film layer and a step of forming a metal thin film layer were alternately repeated on a rotating drum in a vacuum chamber, thereby manufacturing a laminate in which a total of 2,550 resin thin film layers and metal thin film layers (internal electrode metal layers) were alternately laminated on the rotating drum.

[0136] In the process of forming the resin thin film layer, the resin thin film layer was formed from a monomer mixture containing a bifunctional monomer, tricyclodecane dimethanol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: A-DCP), and a monofunctional monomer, 2-(biphenyl-2-yloxy)-ethyl acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: A-LEN-10), in a molar ratio of 50:50. That is, the monomer mixture was vapor-deposited in a vacuum chamber to form a monomer layer, and then the monomer layer was irradiated with an electron beam to cure the monomer layer, thereby forming the resin thin film layer. The electron beam irradiation was performed under conditions of an acceleration voltage of 5.0 kV and an irradiation current of 50 mA. The thickness of the resin thin film layer was 0.5 μm.

[0137] In the step of forming the metal thin film layer, aluminum (Al) was vapor-deposited on the resin thin film layer, a portion of which was masked by vapor-depositing fluorine oil, to form the metal thin film layer. The vapor deposition resistance of the metal thin film layer was 10 Ω / □.

[0138] The produced laminate was removed from the rotating drum and flattened by pressing under heat at 160°C. The flattened laminate was then cut into sticks, to which external electrodes (brass metallicon thermal spray coating, copper plating, and tin plating) were attached, and the resulting pieces were further cut into chips, yielding a thin-film polymer multilayer capacitor according to Example 1. The capacitor size was 4.5 mm x 3.2 mm.

[0139] (Moisture Resistance Environment Evaluation Test) The durability of the capacitor according to Example 1 was evaluated by a moisture resistance environment test. In this moisture resistance environment test, the capacitor was placed in a constant temperature and humidity chamber maintained at a temperature of 60° C. and a relative humidity of 90%, and was left standing for 1000 hours with a DC voltage of 50 V applied.

[0140] The dielectric loss tangent (tanδ) and capacitance were measured before and after the humidity resistance test. The dielectric loss tangent (tanδ) was measured at 25°C and 1 kHz using an LCR meter. The capacitance (μF) of the capacitor was measured at 25°C and 1 kHz using an LCR meter. The results are shown in Table 3 below.

[0141] (Evaluation of Water Absorption of Capacitor) In Example 1, the water absorption of the capacitor was further evaluated according to the following water absorption test.

[0142] Specifically, the capacitor was placed in a constant temperature and humidity chamber at a temperature of 40°C and a relative humidity of 95%, and the weight change rate of the capacitor after leaving it for a predetermined time was measured and defined as the water absorption rate of the capacitor. The results are shown in Table 3 below and Figure 2.

[0143] In Table 3 below, the water absorption of the capacitors was evaluated according to the following criteria: ◯: The water absorption rate measured after the above water absorption test for 500 hours was less than 1%. ×: The water absorption rate measured after the above water absorption test for 500 hours was 1% or more.

[0144] In Comparative Example 1, a capacitor was manufactured and evaluated in the same manner as in Example 1, except that only tricyclodecane dimethanol diacrylate (product name: A-DCP, manufactured by Shin-Nakamura Chemical Co., Ltd.), which is a bifunctional monomer, was used instead of the monomer mixture. The results are shown in Table 3 below and FIG. 2.

[0145]

[0146] As can be seen from Table 3, with regard to the initial characteristics, both the capacitors of Example 1 and Comparative Example 1 exhibited good initial capacitance characteristics (μF). Furthermore, the initial tan δ value of Example 1 was better than that of Comparative Example 1.

[0147] On the other hand, after the humidity resistance test, the capacitor of Comparative Example 1, which was manufactured using only the bifunctional monomer tricyclodecane dimethanol diacrylate, showed a decrease in performance. Specifically, an increase in tan δ and a decrease in capacitance (ΔC<0) were observed.

[0148] In contrast, the capacitor of Example 1 maintained a relatively good tan δ even after the humidity resistance environment evaluation test, and no decrease in capacitance was observed (ΔC>0).

[0149] Furthermore, as can be seen from Table 3 and FIG. 2, the capacitor according to Example 1 exhibited better water absorption than the capacitor according to Comparative Example 1 (relatively reduced water absorption).

[0150] From the above results, it can be seen that by combining a polyfunctional monomer and a monofunctional monomer having a specific HLB value, or a polyfunctional monomer and a monofunctional monomer having a specific water absorption rate measured on a polymer member, it is possible to provide a thin-film polymer multilayer capacitor that has good electrical performance and excellent durability. Without intending to be limited by theory, it is believed that in such a capacitor, the use of a polyfunctional monomer ensures a sufficient degree of cross-linking of the polymer structure in the resin thin film layer, and the use of a monofunctional monomer that results in a polymer with relatively low water absorption reduces the water absorption of the capacitor, resulting in the achievement of good electrical properties and excellent durability of the capacitor.

Claims

1. A thin-film polymer laminate capacitor having a structure in which resin thin-film layers and internal electrode metal layers are alternately laminated, the resin thin film layer has a polymer structure obtained by polymerizing a first monomer which is a polyfunctional monomer and a second monomer which is a monofunctional monomer; A capacitor, wherein the first monomer and the second monomer satisfy at least one of the following conditions (a) and (b): (a) the HLB value H of the second monomer ２ is the HLB value H of the first monomer １ Less than (b) producing a first polymer member formed using only the first monomer as a monomer and a second polymer member formed using only the second monomer as a monomer according to the following production method (1), and measuring the water absorption rate of each polymer member after leaving them to stand for 40 hours under conditions of 40° C. and 95% relative humidity; the water absorption rate of the second polymer member is smaller than the water absorption rate of the first polymer member; Here, the manufacturing method (1) is providing the first monomer or the second monomer as a test monomer; mixing a photoinitiator in a ratio of 0.2±0.01 moles per 100 moles of the test monomer to obtain a mixture; pouring the mixture into a round dish; and The mixture poured into the round dish is irradiated with UV light in a nitrogen atmosphere under conditions of 120 W and a distance of 250 mm until polymerization stops, to prepare a disk-shaped polymer member having dimensions of 30 mm in diameter and 1 mm in depth. It consists of:

2. The HLB value H of the first monomer １ and the HLB value H of the second monomer. ２ Difference with (H １ -H ２ 2. The capacitor of claim 1 , wherein R 1 is 0.1 or greater.

3. The difference (H １ -H ２ 3. The capacitor of claim 2, wherein the ratio of the capacitance to the capacitance of the capacitor is 0.5 or more.

4. The HLB value H of the first monomer １ is in the range of 3.0 to 5.0, The HLB value H of the second monomer ２ is in the range of 2.0 to 4.0; The capacitor according to claim 1 or 2.

5. 3. The capacitor according to claim 1, wherein a molar ratio of the first monomer to the second monomer is from 10:90 to 90:

10.

6. 3. The capacitor according to claim 1, wherein at least one of the first monomer and the second monomer has an acrylate group or a methacrylate group, or at least one of the first monomer and the second monomer includes a monomer having an acrylate group or a methacrylate group.

7. The first monomer and the second monomer each have an acrylate group or a methacrylate group, or the first monomer and the second monomer each include a monomer having an acrylate group or a methacrylate group. The capacitor of claim 6.

8. The capacitor according to claim 1 , wherein the first monomer is a bifunctional monomer.

9. the first monomer is tricyclodecane dimethanol diacrylate or tricyclodecane dimethanol dimethacrylate, or the first monomer comprises tricyclodecane dimethanol diacrylate or tricyclodecane dimethanol dimethacrylate; and / or The second monomer is 2-(biphenyl-2-yloxy)-ethyl acrylate or 4-phenylbenzyl acrylate, or the second monomer includes 2-(biphenyl-2-yloxy)-ethyl acrylate or 4-phenylbenzyl acrylate. The capacitor according to claim 1 or 2.

10. Regarding a third polymer member produced according to the following production method (2), when the third polymer member is left to stand for 40 hours under conditions of 40° C. and 95% relative humidity, the water absorption rate of the third polymer member is 0.8% or less, Here, the manufacturing method (2) is providing said first monomer and said second monomer; mixing the first monomer and the second monomer in the same molar ratio as in the resin thin film layer to obtain a monomer mixture; mixing a photoinitiator in a ratio of 0.2±0.01 moles per 100 moles of the monomer mixture to obtain a mixture; pouring the mixture into a round dish; and The mixture poured into the round dish is irradiated with UV light in a nitrogen atmosphere under conditions of 120 W and a distance of 250 mm until polymerization stops, to prepare a disk-shaped polymer member having dimensions of 30 mm in diameter and 1 mm in depth. Consists of: The capacitor according to claim 1 or 2.

11. 3. The capacitor of claim 1, wherein the capacitor has a dielectric constant of 2.0 or greater when measured at 25° C. and 1 kHz, and a tan δ of less than 1.0% when measured at 25° C. and 1 kHz.

12. A method for manufacturing a thin film polymer multilayer capacitor having a structure in which resin thin film layers and internal electrode metal layers are alternately laminated, comprising the steps of: forming the resin thin film layer by curing a monomer layer containing a first monomer which is a polyfunctional monomer and a second monomer which is a monofunctional monomer; The method, wherein the first monomer and the second monomer satisfy at least one of the following conditions (a) and (b): (a) the HLB value H of the second monomer ２ is the HLB value H of the first monomer １ Less than (b) producing a first polymer member formed using only the first monomer as a monomer and a second polymer member formed using only the second monomer as a monomer according to the following production method (1), and measuring the water absorption rate of each polymer member after leaving them to stand for 40 hours under conditions of 40° C. and 95% relative humidity; the water absorption rate of the second polymer member is smaller than the water absorption rate of the first polymer member; Here, the manufacturing method (1) is providing the first monomer or the second monomer as a test monomer; mixing a photoinitiator in a ratio of 0.2±0.01 moles per 100 moles of the test monomer to obtain a mixture; pouring the mixture into a round dish; and The mixture poured into the round dish is irradiated with UV light in a nitrogen atmosphere under conditions of 120 W and a distance of 250 mm until polymerization stops, to prepare a disk-shaped polymer member having dimensions of 30 mm in diameter and 1 mm in depth. It consists of: