Thin-film polymer multilayer capacitor and method for manufacturing same

Abstract

The purpose of the present invention is to provide a thin-film polymer multilayer capacitor having improved uniformity in the polymer structure of a resin thin-film layer. The present invention relates to a thin-film polymer multilayer capacitor having a laminate structure in which a resin thin-film layer and an internal electrode metal layer are alternately laminated. The resin thin-film layer has a polymer structure obtained by polymerizing two or more types of monomers. The difference Ta−Tb in evaporation temperature between the monomer having the highest evaporation temperature Ta and the monomer having the lowest evaporation temperature Tb is 20°C or less with respect to monomers that form at least 5 mol% of constituent units in the polymer structure among the two or more types of monomers.

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 (thin resin layers) and electrode layers containing metal (internal electrode metal layers) are alternately laminated is known.

[0003] Patent Document 1 describes a thin-film polymer laminate film capacitor and a method for manufacturing the same. The method includes alternately repeating, on a rotating drum, the steps of vapor-depositing a monomer in a vacuum chamber to form a monomer layer, then irradiating the monomer layer with an electron beam to harden the monomer layer to form a resin thin film layer, and vapor-depositing a metal material to form a metal thin film layer. In the examples, the document describes the use of tricyclodecane dimethanol dimethacrylate as the monomer.

[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] Patent Document 3 describes a resin layer forming apparatus for forming a resin layer on a support. This document describes a method of heating and evaporating a liquid resin while it is flowing on a heating plate. It also describes a configuration in which the resin material passes through a porous body (filter) before reaching the support. It states that the resin material is preferably primarily composed of an acrylate resin or a vinyl resin.

[0006] International Publication No. 2015 / 118693 Japanese Patent Application Laid-Open No. 60-157106 Japanese Patent Application Laid-Open No. 2002-75776

[0007] In conventional thin-film polymer multilayer capacitors, laminates consisting of resin thin-film layers (also called dielectric layers) and internal electrode metal layers (also called metal thin-film layers) often lack sufficient chemical uniformity in the polymer structure of the resin thin-film layers. In particular, differences in the component composition of the polymer structure between resin thin-film layers constituting the laminate can occur. For example, differences in the ratio of structural units in the polymer structure can occur between resin thin-film layers deposited early in the manufacturing process and those deposited late in the manufacturing process. Such differences can adversely affect capacitor characteristics (e.g., reduced heat resistance and moisture resistance). In particular, when multiple types of monomers are used, each monomer can have a unique contribution to physical properties and / or durability. Therefore, a decrease in the ratio of at least one monomer in a particular layer can cause changes in the physical properties and / or durability of that layer, potentially resulting in a decrease in the capacitance of the capacitor. Furthermore, differences in physical properties between resin thin film layers (especially between the upper and lower layers of the laminate) can affect the physical characteristics, such as causing warping of the laminate or peeling within the laminate.

[0008] The present invention aims to provide a thin film polymer multilayer capacitor having improved uniformity in the polymer structure of the resin thin film layer, and relates to a method for providing such a capacitor.

[0009] The above-mentioned problems can be solved by the following aspects of the present invention. <Aspect 1> A thin-film polymer multilayer capacitor having a laminate 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 formed by polymerizing two or more types of monomers, and among the two or more types of monomers, for monomers that form 5 mol % or more of structural units in the polymer structure, the difference in evaporation temperature Ta - Tb between the monomer having the highest evaporation temperature Ta and the monomer having the lowest evaporation temperature Tb is 20°C or less. <Aspect 2> The capacitor according to Aspect 1, in which the difference in evaporation temperature Ta - Tb is 15°C or less. <Aspect 3> The capacitor according to Aspect 1, in which the difference in evaporation temperature Ta - Tb is 10°C or less. <Aspect 4> The capacitor according to any one of Aspects 1 to 3, in which, among the two or more types of monomers, monomers that form 5 mol % or more of structural units in the polymer structure each have at least one polymerizable functional group selected from the group consisting of an acryloyl group, a methacryloyl group, an allyl group, and a vinyl group. Aspect 5: The capacitor according to any one of Aspects 1 to 4, wherein, of the two or more monomers, monomers that form 5 mol % or more of the structural units in the polymer structure include a bifunctional monomer having two polymerizable functional groups and a monofunctional monomer having one polymerizable functional group. Aspect 6: The capacitor according to any one of Aspects 1 to 5, wherein, of the two or more monomers, monomers that form 5 mol % or more of the structural units in the polymer structure include a trifunctional or higher functional monomer having three or more polymerizable functional groups, a bifunctional monomer having two polymerizable functional groups, and a monofunctional monomer having one polymerizable functional group. Aspect 7: The capacitor according to any one of Aspects 1 to 6, wherein, of the two or more monomers, monomers that form 5 mol % or more of the structural units in the polymer structure include tricyclodecane dimethanol diacrylate or tricyclodecane dimethanol dimethacrylate, and further include a monofunctional monomer having one polymerizable functional group.<Aspect 8> The capacitor according to any one of Aspects 1 to 7, wherein, of the two or more monomers, a monomer that forms 5 mol % or more of the structural units in the polymer structure comprises n-stearyl acrylate or 2-orthophenylphenoxyethyl acrylate. <Aspect 9> The capacitor according to Aspect 8, wherein, of the two or more monomers, a monomer that forms 5 mol % or more of the structural units in the polymer structure further comprises pentaerythritol triacrylate, pentaerythritol tetraacrylate, or trimethylolpropane triacrylate. <Aspect 10> The capacitor according to any one of Aspects 1 to 9, wherein, of the two or more monomers, each of the monomers that form 5 mol % or more of the structural units in the polymer structure has an evaporation temperature of 100°C to 200°C under conditions of 1 Pa to 10 Pa. <Aspect 11> The capacitor according to any one of Aspects 1 to 10, wherein, of the two or more monomers, each of the monomers that form 5 mol % or more of the structural units in the polymer structure has an evaporation temperature of 120°C to 160°C under conditions of 1 Pa to 10 Pa. <Aspect 12> A method for producing a thin film polymer multilayer capacitor having a laminate in which resin thin film layers and internal electrode metal layers are alternately laminated, comprising: forming a resin thin film layer by curing a monomer layer formed by vapor deposition of a monomer mixture containing two or more types of monomers, forming an internal electrode metal layer by vapor deposition of metal on the resin thin film layer, and forming the laminate by alternately repeating the formation of the resin thin film layer and the formation of the internal electrode metal layer, wherein, for monomers contained in the monomer mixture that account for 5 mol % or more of the two or more types of monomers, the difference in evaporation temperature Ta - Tb between the monomer having the highest evaporation temperature Ta and the monomer having the lowest evaporation temperature Tb is 20°C or less. <Aspect 13> The method according to Aspect 12, comprising contacting the monomer mixture with a heated inclined plate when forming the monomer layer.

[0010] According to the present invention, it is possible to provide a thin film polymer multilayer capacitor having improved uniformity in the polymer structure of the resin thin film layer, and to provide a method for providing such a capacitor.

[0011] In particular, the present invention provides a thin film polymer multilayer capacitor having a relatively high degree of uniformity in polymer structure between the resin thin film layers laminated at the beginning of the manufacturing process and those laminated at the end of the manufacturing process, and a method for manufacturing the same.

[0012] Fig. 1 is a perspective view of a thin film polymer multilayer capacitor. Fig. 2 shows the results of FT-IR analysis of a resin thin film layer laminated at an early stage in the capacitor manufacturing process in Example 2. Fig. 3 shows the results of FT-IR analysis of a resin thin film layer laminated at a final stage in the capacitor manufacturing process in Example 2. Fig. 4 shows the results of FT-IR analysis of a resin thin film layer laminated at an early stage in the capacitor manufacturing process in Comparative Example 1. Fig. 5 shows the results of FT-IR analysis of a resin thin film layer laminated at a final stage in the capacitor manufacturing process in Comparative Example 1.

[0013] <<Thin Film Polymer Multilayer Capacitor>> The capacitor according to the present invention is a thin film polymer multilayer capacitor having a laminate 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 two or more types of monomers, and among the two or more types of monomers, for monomers that form 5 mol % or more of structural units in the polymer structure, the difference in evaporation temperature Ta - Tb between the monomer having the highest evaporation temperature Ta and the monomer having the lowest evaporation temperature Tb is 20°C or less.

[0014] As described above, in conventional thin-film polymer multilayer capacitors, the polymer structure of the resin thin film layer in the laminate consisting of the resin thin film layer and the internal electrode metal layer can be relatively non-uniform. In particular, there can be differences in the component ratios of the structural units of the polymer structure between the resin thin film layer laminated at the beginning of the manufacturing process and the resin thin film layer laminated at the end of the manufacturing process. Such differences can adversely affect the capacitor characteristics.

[0015] In response to this, the present inventors have discovered that when forming a resin thin film layer by thermal evaporation of a mixture containing two or more monomers, fluctuations in the constituent ratios in the polymer structure of the resulting resin thin film layer can be suppressed by adjusting the evaporation temperature characteristics of each monomer to an appropriate relationship.

[0016] Without intending to be limited by theory, it is believed that when a raw material containing a mixture of multiple monomer components is used, if the evaporation temperatures of the individual monomers differ significantly, the ratio of the evaporated components changes over time. Because the process of forming a laminate can take a long time, the polymer composition at the beginning and end of the laminate may differ, which may affect the dielectric properties. Such changes in the ratio of the components are particularly likely to occur with monomers that have relatively low evaporation temperatures.

[0017] For example, when a mixed monomer having a relatively large difference in evaporation temperature between the constituent monomers is used, a clear difference in the component ratio may appear between the "drum-side layer (i.e., the layer deposited initially) and the layer on the opposite side (i.e., the layer deposited towards the end of production)" of the laminate. This component ratio can be measured and calculated, for example, from the peaks in the FT-IR spectrum.

[0018] It is also possible to increase the temperature for evaporating the mixed monomers (e.g., the temperature of the heating ramp used to heat the mixed monomers) so that monomers with relatively high evaporation temperatures can also be sufficiently evaporated, thereby suppressing the ratio fluctuations in the polymer structure.

[0019] However, if the temperature for evaporating the mixed monomer is too high, the curing reaction may start, making it difficult to form a satisfactory monomer layer. The curing initiation temperature of the monomer is, for example, around 200°C, which is often relatively close to the evaporation temperature of the monomer (for example, 100 to 160°C).

[0020] In contrast, the present invention suppresses the ratio fluctuation in the polymer structure by optimizing the evaporation temperature characteristics of each monomer constituting the mixed monomer. Therefore, there is no need to excessively increase the temperature for evaporating the mixed monomer, and the progress of the curing reaction during the monomer evaporation process can be suppressed.

[0021] Another possible approach is to prepare multiple evaporation sources, evaporate each of two or more monomers, and then mix them before depositing them on a rotating drum. However, this approach requires expensive equipment and requires high electricity costs, which can be disadvantageous for industrial production. Furthermore, the individual monomers may not be mixed well, resulting in uneven distribution of components, making film formation more difficult and making it difficult to achieve stable capacitor performance. According to the present invention, a high-quality resin thin film layer formed from two or more monomers can be produced using a single heating source.

[0022] The methods according to the present disclosure are described in more detail below.

[0023] <Evaporation temperature> In the capacitor according to the present invention, the resin thin film layer has a polymer structure formed by polymerizing two or more types of monomers, and for monomers among the two or more types of monomers that form 5 mol % or more of structural units (monomer units) in the polymer structure, the difference in evaporation temperature Ta-Tb between the monomer having the highest evaporation temperature Ta and the monomer having the lowest evaporation temperature Tb is 20°C or less.

[0024] According to the present invention, the difference in evaporation temperature between monomers that form structural units at a relatively high ratio in the polymer structure is relatively reduced. This stabilizes the ratio of monomer structural units in the resulting polymer structure, resulting in good capacitor properties. Furthermore, monomers that have a relatively low ratio in the polymer structure (especially less than 5 mol%) are believed to have a relatively low contribution to the properties of the resulting polymer structure and, in turn, the properties of the capacitor. Therefore, optimizing the evaporation temperature of monomers with a relatively high ratio is considered important for improving capacitor properties.

[0025] In one aspect of the present invention, the evaporation temperature is also optimized for monomers that have a relatively small proportion of constituent units in the polymer structure. That is, for example, for monomers that form 4 mol % or more, 3 mol % or more, 2 mol % or more, 1 mol % or more, 0.5 mol % or more, or even 0.1 mol % or more of constituent units in the polymer structure among two or more monomers, the difference in evaporation temperature Ta-Tb between the monomer having the highest evaporation temperature Ta and the monomer having the lowest evaporation temperature Tb is 20°C or less.

[0026] In a further embodiment of the present invention, the evaporation temperatures of all monomers constituting the polymer structure are optimized, i.e., the difference in evaporation temperature Ta-Tb between the monomer having the highest evaporation temperature Ta and the monomer having the lowest evaporation temperature Tb among two or more monomers constituting the polymer structure is 20°C or less.

[0027] The "evaporation temperature" of a monomer can be measured using a thermogravimetric differential thermal analyzer (TG-DTA), and specifically can be determined as follows: 0.01 g of a simple monomer sample consisting only of the target monomer is heated to a temperature of 300°C at a constant heating rate of 20°C / min using a thermogravimetric differential thermal analyzer under a reduced pressure of 1 to 10 Pa, and the weight loss when heated is measured, and the temperature at which the rate of weight loss becomes maximum is determined and can be taken as the evaporation temperature. The "temperature at which the rate of weight loss becomes maximum" refers to the temperature at which the slope of the curve obtained by plotting the weight change against the temperature becomes maximum in the decreasing direction.

[0028] The evaporation temperature of each monomer may be, for example, within the range of 80°C to 200°C.

[0029] In a preferred embodiment of the present invention, among the two or more monomers constituting the polymer structure, monomers that form 5 mol% or more of the structural units in the polymer structure (particularly, among the two or more monomers, monomers that form 4 mol% or more, 3 mol% or more, 2 mol% or more, 1 mol% or more, 0.5 mol% or more, or 0.1 mol% or more of the structural units in the polymer structure, or the two or more monomers constituting the polymer structure) each have an evaporation temperature of 100°C to 200°C, more preferably 120°C to 160°C. These embodiments are particularly advantageous in terms of appropriately evaporating the monomers while suppressing the progress of the curing reaction.

[0030] The evaporation temperatures of exemplary monomers are as follows: n-stearyl acrylate: 153°C; tricyclodecane dimethanol diacrylate: 139°C; 2-(biphenyl-2-yloxy)-ethyl acrylate: 135°C; triallyl isocyanurate: 110°C; pentaerythritol triacrylate: 153°C; pentaerythritol tetraacrylate: 155°C; tricyclodecane dimethanol dimethacrylate: 151°C; 4-phenylbenzyl acrylate: 136°C; trimethylolpropane triacrylate: 120°C.

[0031] The evaporation temperature difference Ta-Tb may be 18°C ​​or less, 16°C or less, 14°C or less, 12°C or less, 10°C or less, 8°C or less, 6°C or less, 5°C or less, 4°C or less, 3°C or less, or 2°C or less. The lower limit of this evaporation temperature difference is not particularly limited, and may be, for example, 0.1°C or more, 0.2°C or more, 0.5°C or more, or 1°C or more.

[0032] The difference Ta-Tb is preferably 15°C or less, and more preferably 10°C or less.

[0033] In one aspect of the present invention, among the two or more monomers constituting the polymer structure, monomers that form 5 mol% or more of the structural units in the polymer structure (particularly, among the two or more monomers, monomers that form 4 mol% or more, 3 mol% or more, 2 mol% or more, 1 mol% or more, 0.5 mol% or more, or 0.1 mol% or more of the structural units in the polymer structure, or the two or more monomers constituting the polymer structure) include, in addition to a bifunctional monomer, at least one selected from the group consisting of a monofunctional monomer, a trifunctional monomer, a tetrafunctional monomer, and a pentafunctional or higher monomer ("other monomer"), and optionally, the difference in evaporation temperature of the other monomer relative to the evaporation temperature of the bifunctional monomer is 20°C or less, 18°C ​​or less, 16°C or less, 14°C or less, 12°C or less, 10°C or less, 8°C or less, 6°C or less, 5°C or less, 4°C or less, 3°C or less, or 2°C or less. The lower limit of this evaporation temperature difference is not particularly limited, but may be, for example, 0.1°C or more, 0.2°C or more, 0.5°C or more, or 1°C or more.

[0034] <Thermal curing initiation temperature> The thermal curing initiation temperature of a monomer can be one parameter when determining the manufacturing conditions of a capacitor manufacturing method involving monomer vapor deposition. If the temperature applied externally for monomer evaporation is too close to the thermal curing initiation temperature of the monomer, the curing reaction may proceed excessively, which may affect the capacitor characteristics.

[0035] The thermosetting initiation temperature of a monomer can be measured using a single sample containing only the target monomer. Specifically, the onset point of the exothermic peak can be detected in a heat flow diagram obtained by thermogravimetric differential thermal analysis (TG-DTA) (heating rate: 20°C / min) under a nitrogen atmosphere, and this can be used as the thermosetting initiation temperature.

[0036] For reference, the thermal curing initiation temperatures of some monomers are shown below: Tricyclodecane dimethanol diacrylate: 198°C 2-(biphenyl-2-yloxy)-ethyl acrylate: 206°C

[0037] <Resin Thin Film Layer> The resin thin film layer of the capacitor according to the present disclosure has a polymer structure obtained by polymerizing two or more types of monomers.

[0038] The monomer may have a polymerizable functional group.

[0039] (Polymerizable Functional Group) Examples of the polymerizable functional group include a vinyl group, an acryloyl group, a methacryloyl group, an allyl group, an isopropenyl group, and an epoxy group.

[0040] The vinyl group is CH ２ ═CH—. Specific examples of the polymerizable functional group include an acryloyl group (CH ２ ═CH—C(═O)), methacryloyl group (CH ２ =C(CH ３ )-C(=O)), acrylate group (CH ２ ═CH—C(═O)—O), methacrylate group ((CH ２ =C(CH ３ )-C(=O)-O), an allyl group (CH ２ =CH-CH ２ -), and CH ２ Examples include a group represented by =CH-R- (R is a hydrocarbon group containing 2 to 12 carbon atoms). R may be, for example, an alkylene group, or a hydrocarbon group containing an alicyclic structure or a benzene ring. R particularly contains 2 to 8, more particularly 2 to 4, carbon atoms.

[0041] The two or more monomers can be polymerized via the polymerizable functional groups under conditions such as electron beam irradiation to form a macromolecular structure (polymer).

[0042] In one embodiment of the present invention, among the two or more monomers constituting the polymer structure, the monomers that form 5 mol% or more of the structural units in the polymer structure (particularly, among the two or more monomers, the monomers that form 4 mol% or more, 3 mol% or more, 2 mol% or more, 1 mol% or more, 0.5 mol% or more, or 0.1 mol% or more of the structural units in the polymer structure, or the two or more monomers constituting the polymer structure) include at least a bifunctional monomer having two polymerizable functional groups and a monofunctional monomer having one polymerizable functional group. In this case, a capacitor with excellent environmental resistance can be obtained, and in particular, a capacitor with relatively reduced water absorption can be obtained.

[0043] In one embodiment of the present invention, among the two or more monomers constituting the polymer structure, monomers that form 5 mol% or more of the structural units in the polymer structure (particularly, among the two or more monomers, monomers that form 4 mol% or more, 3 mol% or more, 2 mol% or more, 1 mol% or more, 0.5 mol% or more, or 0.1 mol% or more of the structural units in the polymer structure, or two or more monomers constituting the polymer structure) include trifunctional or higher monomers having three or more polymerizable functional groups, bifunctional monomers having two polymerizable functional groups, and monofunctional monomers having one polymerizable functional group. When a monofunctional monomer is added to a bifunctional monomer, the interlayer adhesion in the laminate may decrease. In contrast, by further adding a trifunctional monomer to the bifunctional monomer and the monofunctional monomer, excellent interlayer adhesion in the laminate can be obtained.

[0044] In one embodiment of the present invention, among the two or more monomers constituting the polymer structure, a monomer that forms 5 mol % or more of the structural units in the polymer structure (particularly, among the two or more monomers, a monomer that forms 4 mol % or more, 3 mol % or more, 2 mol % or more, 1 mol % or more, 0.5 mol % or more, or 0.1 mol % or more of the structural units in the polymer structure, or two or more monomers constituting the polymer structure) comprises tricyclodecane dimethanol diacrylate or tricyclodecane dimethanol dimethacrylate, and further comprises a monofunctional monomer having one polymerizable functional group.

[0045] In another aspect of the present invention, among the two or more monomers constituting the polymer structure, a monomer that forms 5 mol % or more of the structural units in the polymer structure (particularly, among the two or more monomers, a monomer that forms 4 mol % or more, 3 mol % or more, 2 mol % or more, 1 mol % or more, 0.5 mol % or more, or 0.1 mol % or more of the structural units in the polymer structure, or two or more monomers constituting the polymer structure) comprises n-stearyl acrylate or 2-orthophenylphenoxyethyl acrylate.

[0046] In yet another embodiment of the present invention, among the two or more monomers constituting the polymer structure, a monomer that forms 5 mol% or more of the structural units in the polymer structure (particularly, among the two or more monomers, a monomer that forms 4 mol% or more, 3 mol% or more, 2 mol% or more, 1 mol% or more, 0.5 mol% or more, or 0.1 mol% or more of the structural units in the polymer structure, or two or more monomers constituting the polymer structure) further comprises pentaerythritol triacrylate, pentaerythritol tetraacrylate, triallyl isocyanurate, or trimethylolpropane triacrylate. Particularly preferably, the two or more monomers further comprise pentaerythritol triacrylate, pentaerythritol tetraacrylate, or trimethylolpropane triacrylate.

[0047] (Monofunctional Monomer) A monofunctional monomer has one polymerizable functional group in one molecule.

[0048] The monofunctional monomer preferably comprises a monomer having an acryloyl group or a methacryloyl group, or consists of a monomer having an acryloyl group or a methacryloyl group.

[0049] In one embodiment according to the present disclosure, the monofunctional monomer can have a chemical structure represented by the following general formula (1):

[0050]

[0051] In formula (1), R ３ is a group containing 1 to 20 carbon atoms; R ２ is H or CH ３ is.

[0052] R in formula (1) ２ is preferably H.

[0053] R in formula (1) ３ preferably contains 3 to 20, more preferably 6 to 20, and even more preferably 8 to 20 carbon atoms.

[0054] R in formula (1) ３ may contain an oxygen atom. In this case, R ３can contain 1 to 20, 1 to 10, 1 to 5, 1 to 3, 1 to 2, or 1 oxygen atom.

[0055] R in formula (1) 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.

[0056] Preferably, R in formula (1) ３ consists of carbon and hydrogen atoms, and optionally oxygen atoms.

[0057] In formula (1), R ３ can contain aliphatic (linear or branched) moieties, alicyclic moieties, and / or aromatic moieties.

[0058] R in formula (1) 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.

[0059] R in formula (1) 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.

[0060] R ３ Particularly preferably, has a biphenyl structure.

[0061] In formula (1), R ３It 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.

[0062] Examples of the compound structures S1 to S8 of the monofunctional monomers that can be used in the present invention are shown below.

[0063]

[0064] In the chemical formulae S1 and S2, 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.

[0065] In the chemical formulas S5 and S6, n may be 1 to 20, preferably 5 to 18, and more preferably 12 to 17.

[0066] 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.

[0067] Examples of preferred compound structures of monofunctional monomers are shown below.

[0068]

[0069] Particularly preferred monofunctional monomers include 2-(biphenyl-2-yloxy)-ethyl acrylate, 4-phenylbenzyl acrylate, n-stearyl acrylate, n-stearyl methacrylate, and 2-orthophenylphenoxyethyl acrylate.

[0070] (Proportion of monofunctional monomers) Among the two or more monomers constituting the polymer structure, monomers that form 5 mol% or more of structural units in the polymer structure (particularly, among the two or more monomers, monomers that form 4 mol% or more, 3 mol% or more, 2 mol% or more, 1 mol% or more, 0.5 mol% or more, or 0.1 mol% or more of structural units in the polymer structure, or two or more monomers constituting the polymer structure) may contain a monofunctional monomer, in which case the content of the monofunctional monomer in the two or more monomers may be 5 to 75 mol% or even 6 to 70 mol%, preferably 8 to 65 mol% or even 10 to 60 mol%, more preferably 12 to 58 mol% or even 15 to 55 mol%. That is, with respect to the polymer structure of the resin thin film layer contained in the capacitor, the proportion of the structural units (or repeating units) derived from monofunctional monomers that constitute this polymer structure may be 5 to 75 mol % or even 6 to 70 mol %, preferably 8 to 65 mol % or even 10 to 60 mol %, and more preferably 12 to 58 mol % or even 15 to 55 mol %, relative to the total structural units (or repeating units) of the polymer structure.

[0071] (Bifunctional Monomer) A bifunctional monomer has two polymerizable functional groups in one molecule.

[0072] The bifunctional monomer preferably comprises or consists of a monomer having an acryloyl group or a methacryloyl group.

[0073] In one embodiment according to the present disclosure, the bifunctional monomer can have a chemical structure represented by the following general formula (2):

[0074]

[0075] In formula (2), R １ is a group containing 1 to 20 carbon atoms; R ２ are each independently H or CH ３ is.

[0076] In formula (2), R １ preferably contains 3 to 20, more preferably 6 to 20, and even more preferably 8 to 20 carbon atoms.

[0077] R in formula (2) 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.

[0078] R in formula (2) 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.

[0079] Preferably, R in formula (2) １ consists of carbon and hydrogen atoms, and optionally oxygen atoms.

[0080] In formula (2), R １ can contain aliphatic (linear or branched) moieties, alicyclic moieties, and / or aromatic moieties.

[0081] R in formula (2) 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.

[0082] R in formula (2) 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.

[0083] In formula (2), 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.

[0084] Examples of the compound structures F1 to F6 of the bifunctional monomer that can be used in the present invention are shown below.

[0085]

[0086] In the chemical formulae F3 and F4, n may be 1 to 20, preferably 5 to 18, more preferably 8 to 15, and even more preferably 9 to 12.

[0087] In the chemical formulae F5 and F6, n may be 1 to 20, preferably 1 to 10, more preferably 2 to 6, and even more preferably 3 to 4.

[0088] Particularly preferred bifunctional monomers include: tricyclodecane dimethanol diacrylate, tricyclodecane dimethanol dimethacrylate.

[0089] (Proportion of Bifunctional Monomer) Of the two or more monomers constituting the polymer structure, monomers that form 5 mol% or more of structural units in the polymer structure (particularly, of the two or more monomers, monomers that form 4 mol% or more, 3 mol% or more, 2 mol% or more, 1 mol% or more, 0.5 mol% or more, or 0.1 mol% or more of structural units in the polymer structure, or two or more monomers constituting the polymer structure) may contain a bifunctional monomer, and in that case, the content of the bifunctional monomer in the two or more monomers may be 10 to 90 mol% or even 15 to 85 mol%, preferably 20 to 80 mol% or even 25 to 75 mol%, more preferably 30 to 70 mol%. That is, with respect to the polymer structure of the resin thin film layer contained in the capacitor, the proportion of the structural units (or repeating units) derived from the bifunctional monomer that constitute this polymer structure may be 10 to 90 mol % or even 15 to 85 mol %, preferably 20 to 80 mol % or even 25 to 75 mol %, more preferably 30 to 70 mol %, relative to the total structural units (or repeating units) of the polymer structure.

[0090] (Trifunctional or higher functional monomer) A trifunctional or higher functional monomer has three or more polymerizable functional groups in one molecule. Trifunctional or higher functional monomers include, in particular, trifunctional monomers (monomers having three polymerizable functional groups in one molecule) and tetrafunctional monomers (monomers having four polymerizable functional groups in one molecule).

[0091] In one embodiment according to the present disclosure, the tri- or higher functional monomer includes a monomer having an acryloyl group or a methacryloyl group, or consists of a monomer having an acryloyl group or a methacryloyl group.

[0092] The tri- or higher functional monomer may have, for example, a chemical structure represented by the following general formula (3).

[0093]

[0094] In formula (3), R ４ is a group containing 1 to 20 carbon atoms; R ２ are each independently H or CH ３ and n is 3 or 4.

[0095] In formula (3), n is preferably 3.

[0096] In formula (3), R ４ preferably contains 1 to 20, more preferably 2 to 12, and even more preferably 3 to 8 carbon atoms.

[0097] R in formula (3) ４ may also contain an oxygen atom. In this case, R ４ 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. ４ does not contain an oxygen atom.

[0098] R in formula (3) ４ may also contain an ether bond. In this case, R ４ 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.

[0099] Preferably, R in formula (3) ４ consists of carbon and hydrogen atoms, and optionally oxygen atoms. Particularly preferably, R ４ is a hydrocarbon group consisting of only carbon and hydrogen atoms, particularly a hydrocarbon group having 3 to 8 carbon atoms.

[0100] In formula (3), R ４ can contain aliphatic (linear or branched) moieties, alicyclic moieties, and / or aromatic moieties.

[0101] In formula (3), R ４ 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.

[0102] Among the compounds represented by the above formula (3), the compound structure of trimethylolpropane triacrylate is shown below as an example of a trifunctional monomer.

[0103]

[0104] An example of a tri- or higher functional monomer having an allyl group is triallyl isocyanurate (commercially available as "TAIC" (registered trademark)).

[0105] Other preferred examples include pentaerythritol triacrylate, pentaerythritol tetraacrylate, and mixtures thereof, in which the ratio of tri-type to tetra-type may be 0.4 to 0.8.

[0106] (Proportion of trifunctional or higher functional monomers) Among the two or more monomers constituting the polymer structure, monomers that form 5 mol% or more of structural units in the polymer structure (particularly, among the two or more monomers, monomers that form 4 mol% or more, 3 mol% or more, 2 mol% or more, 1 mol% or more, 0.5 mol% or more, or 0.1 mol% or more of structural units in the polymer structure, or two or more monomers constituting the polymer structure) may contain trifunctional or higher functional monomers, in which case, the content of trifunctional or higher functional monomers in the two or more monomers may be 5 to 40 mol%, preferably 5 to 35 mol% or even 5 to 30 mol%, more preferably 6 to 25 mol% or even 6 to 20 mol%, particularly preferably 7 to 18 mol% or even 8 to 15 mol%. That is, with regard to the polymer structure of the resin thin film layer contained in the capacitor, the proportion of structural units (or repeating units) derived from trifunctional or higher functional monomers constituting this polymer structure may be 5 to 40 mol %, preferably 5 to 35 mol % or even 5 to 30 mol %, more preferably 6 to 25 mol % or even 6 to 20 mol %, and particularly preferably 7 to 18 mol % or even 8 to 15 mol %, relative to the total structural units (or repeating units) of the polymer structure.

[0107] (Monomer Composition) When the monomers forming 5 mol % or more of the structural units in the polymer structure among the two or more monomers constituting the polymer structure (particularly, the monomers forming 4 mol % or more, 3 mol % or more, 2 mol % or more, 1 mol % or more, 0.5 mol % or more, or 0.1 mol % or more of the structural units in the polymer structure among the two or more monomers, or the two or more monomers constituting the polymer structure) contain monofunctional and bifunctional monomers, the relative molar ratio is preferably as follows: monofunctional monomer:bifunctional monomer=10-60:90-40, more preferably 15-50:85-50

[0108] When the monomers that form 5 mol % or more of the structural units in the polymer structure among the two or more monomers that constitute the polymer structure (particularly, the monomers that form 4 mol % or more, 3 mol % or more, 2 mol % or more, 1 mol % or more, 0.5 mol % or more, or 0.1 mol % or more of the structural units in the polymer structure among the two or more monomers, or the two or more monomers that constitute the polymer structure) contain monofunctional, bifunctional, and trifunctional or higher functional monomers, the relative molar ratio is preferably as follows: monofunctional monomer: bifunctional monomer: trifunctional or higher functional monomer=15-60:40-85:1-20, more preferably 20-50:40-75:5-15

[0109] <Thin Film Polymer Multilayer Capacitor> The thin film polymer multilayer capacitor according to the present disclosure has a structure (laminated structure) in which thin resin layers and internal electrode metal layers are alternately laminated.

[0110] 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.

[0111] The thin film polymer multilayer capacitor can have 10 to 10,000 layers, 50 to 5,000 layers, or 100 to 2,000 layers.

[0112] 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.

[0113] 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, and is preferably aluminum.

[0114] 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 / □.

[0115] <Method for Manufacturing Capacitor> The method for manufacturing the thin-film polymer multilayer capacitor according to the present disclosure is not particularly limited. For example, the thin-film polymer multilayer 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 depositing a metal material to form a metal thin film layer, thereby manufacturing a laminate in which resin thin film layers and metal thin film layers are alternately stacked on the rotating drum.

[0116] 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.

[0117] (Method for manufacturing a capacitor according to the present disclosure) The present disclosure includes a method for manufacturing a thin film polymer laminate capacitor having a laminate 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 formed by vapor deposition of a monomer mixture containing two or more types of monomers; forming an internal electrode metal layer by vapor deposition of metal on the resin thin film layer; and forming a laminate by alternately repeating the formation of the resin thin film layer and the formation of the internal electrode metal layer, wherein, for monomers contained in the monomer mixture at a content of 5 mol % or more, among the two or more monomers, the difference in evaporation temperature Ta - Tb between the monomer having the highest evaporation temperature Ta and the monomer having the lowest evaporation temperature Tb is 20°C or less.

[0118] This manufacturing method according to the present disclosure is particularly suitable for manufacturing the above-described capacitor according to the present disclosure. For details of each component (monomer, resin thin film layer, internal electrode metal layer, evaporation temperature and difference therebetween, etc.) and suitable ranges of values ​​in this manufacturing method, please refer to the above description of the capacitor according to the present disclosure.

[0119] According to the manufacturing method of the present disclosure, when a resin thin film layer is formed by thermal evaporation of a mixture containing two or more monomers, the evaporation temperature characteristics of each monomer can be made to have an appropriate relationship, thereby suppressing fluctuations in the constituent ratios in the polymer structure of the resin thin film layer to be formed.

[0120] Furthermore, according to the manufacturing method of the present disclosure, the vaporization temperature characteristics of the monomers constituting the mixed monomer are set in an appropriate relationship, thereby suppressing fluctuations in the ratio of the monomers in the polymer structure. Therefore, there is no need to excessively increase the temperature for vaporizing the mixed monomer, and unwanted curing reactions of the mixed monomer can be suppressed.

[0121] In one embodiment of the production method according to the present invention, the evaporation temperature is also optimized for monomers that are present in a relatively small proportion in the monomer mixture, i.e., for example, for monomers whose content in the monomer mixture is 4 mol % or more, 3 mol % or more, 2 mol % or more, 1 mol % or more, 0.5 mol % or more, or even 0.1 mol % or more, the difference in evaporation temperature Ta-Tb between the monomer having the highest evaporation temperature Ta and the monomer having the lowest evaporation temperature Tb is 20°C or less.

[0122] In a further aspect of the invention, the evaporation temperature is optimized for all monomers in the monomer mixture, i.e., the difference in evaporation temperature Ta-Tb between the monomer having the highest evaporation temperature Ta and the monomer having the lowest evaporation temperature Tb among the monomer mixture is 20°C or less.

[0123] (Monomer) The molar amount of the monomer in the monomer mixture used in the manufacturing process is considered to correspond to the molar amount of the monomer unit in the formed resin thin film layer. Therefore, with regard to the respective molar amounts of the monofunctional monomer, bifunctional monomer, and trifunctional or higher functional monomer that can be used in the manufacturing process, reference can be made to the description of the content (and content ratio) of the monofunctional monomer, bifunctional monomer, and trifunctional or higher functional monomer described above in relation to the capacitor of the present disclosure.

[0124] (Preparation of Mixed Monomer) The mixed monomer may be prepared by mixing two or more monomers. Stirring may be performed appropriately during mixing and when using the mixed monomer. The mixed monomer may be in a liquid state.

[0125] (Formation of Monomer Layer) In the manufacturing method according to the present invention, a monomer layer is formed by vapor deposition of a mixed monomer containing two or more types of monomers. Specifically, the raw material monomers are heated and evaporated to generate vapor, which is then condensed on the surface of the substrate, thereby depositing the monomer layer in the form of a thin film.

[0126] A mixed monomer containing two or more kinds of monomers may be heated, for example, under a reduced pressure of 5 to 100 Pa at a temperature in the range of 150 to 230°C (particularly 160 to 200°C), thereby converting the monomers into a vapor state.

[0127] In one embodiment of the method of the present invention, when forming the monomer layer, the monomer mixture is brought into contact with a heated inclined plate, which effectively vaporizes the monomer mixture and allows it to be used to form the monomer layer.

[0128] (Evaporator) An evaporator can be used for vapor deposition of the monomer. The evaporator is connected to a vacuum chamber. The evaporator may have a heated inclined plate inside. The inner wall of the evaporator may also be heated (for example, 220°C). When the inner wall of the evaporator is heated, its temperature may be higher or lower than that of the inclined plate.

[0129] In the evaporator, the monomer mixture is vaporized by dropping it onto a heated inclined plate (oil circulation type). The vaporized monomer is then transferred to a vacuum chamber, where it is possible to form a monomer layer on a rotating drum.

[0130] The mixed monomer dropped onto the inclined plate evaporates while flowing down the inclined plate. The remaining monomer that has not evaporated on the inclined plate and the monomer that has aggregated on the inner wall of the evaporator may be recovered in a recovery tank installed downstream of the inclined plate.

[0131] (Inclined Plates) The inclined plates may be multiple, and may include, for example, an upstream inclined plate and a downstream inclined plate. These inclined plates may be configured so that the mixed monomer dropped onto the upstream inclined plate flows down the upstream inclined plate and drops onto the downstream inclined plate. Furthermore, a recovery tank may be disposed downstream of the downstream inclined plate, so that the mixed monomer that flows down the downstream inclined plate (and the monomer that condenses and liquefies on the inner wall of the evaporator) is recovered in the recovery tank.

[0132] The temperature of the inclined plate can be determined taking into consideration the evaporation temperature and curing initiation temperature of the monomers constituting the mixed monomer. If the temperature of the inclined plate is too high, the amount of monomer curing on the inclined plate may be excessive. If the temperature of the inclined plate is too low, the evaporation of the monomer may be insufficient, which may result in large fluctuations in the monomer ratio.

[0133] The inclined plate may be heated to a temperature of 120 to 250°C, preferably 150 to 220°C, more preferably 160 to 200°C.

[0134] The ramp is preferably made of a material that has good thermal conductivity and is not easily broken, and may be made of copper, for example.

[0135] The size of the inclined plate is not particularly limited, but may have a length of, for example, 10 cm to 200 cm, particularly 20 to 100 cm, along the direction in which the mixed monomer flows.

[0136] Without intending to be limited by theory, it is believed that when multiple monomers (mixed monomers) having different evaporation temperatures are evaporated using an evaporator with an inclined plate, the monomer with a relatively low evaporation temperature starts to evaporate first, and then, as the mixed monomer flows down the inclined plate, the other monomers with a relatively high evaporation temperature gradually start to evaporate.

[0137] Furthermore, because the lamination process can take a long time (e.g., 2 to 3 hours), over time, a thermoset (a product resulting from the curing of the monomer) gradually accumulates on the inclined plate, and the surface of the inclined plate is gradually covered with the thermoset, starting from the upstream side. While not intending to be limited by theory, it is believed that in this case, the heat transferred from the upstream portion of the inclined plate to the mixed monomer dripped onto the inclined plate in the latter part of the lamination process decreases, and therefore, the monomers in the mixed monomer having a relatively high evaporation temperature do not fully evaporate in this upstream portion, but instead flow and diffuse to the downstream portion of the inclined plate. In other words, over time, the proportion of the monomers with a relatively high evaporation temperature among the monomers remaining on the inclined plate increases, resulting in a change in the monomer ratio in the monomer vapor sent to the vacuum chamber.

[0138] (Curing Treatment) The step of curing the monomer layer to form a resin thin film layer can be performed according to a known method, for example, according to the method described in International Publication No. 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.

[0139] (Formation of Metal Thin Film Layer) A known method can be used for forming a metal thin film layer and for alternately laminating resin thin film layers and metal thin film layers. For example, the method described in WO 2015 / 118693 can be used.

[0140] In one embodiment of the manufacturing method according to the present disclosure, the internal electrode metal layer is formed by a vapor deposition method.

[0141] (Aspects Related to the Production Method) Specific aspects of the production method according to the present disclosure are listed below as examples: The difference in evaporation temperature Ta-Tb is 15°C or less. The difference in evaporation temperature Ta-Tb is 10°C or less. A monomer contained in the mixed monomer mixture at a ratio of 5 mol% or more (particularly, a monomer contained in the mixed monomer mixture at a ratio of 4 mol% or more, 3 mol% or more, 2 mol% or more, 1 mol% or more, 0.5 mol% or more, or 0.1 mol% or more, or each monomer constituting the mixed monomer) has at least one polymerizable functional group selected from the group consisting of an acrylic group, a methacrylic group, an allyl group, and a vinyl group. Monomers contained in the mixed monomer mixture at a ratio of 5 mol% or more (particularly, monomers contained in the mixed monomer mixture at a ratio of 4 mol% or more, 3 mol% or more, 2 mol% or more, 1 mol% or more, 0.5 mol% or more, or 0.1 mol% or more, or mixed monomers) include bifunctional monomers having two polymerizable functional groups and monofunctional monomers having one polymerizable functional group. Monomers contained in the mixed monomer mixture at a ratio of 5 mol% or more (particularly, monomers contained in the mixed monomer mixture at a ratio of 4 mol% or more, 3 mol% or more, 2 mol% or more, 1 mol% or more, 0.5 mol% or more, or 0.1 mol% or more, or mixed monomers) include trifunctional or higher functional monomers having three or more polymerizable functional groups, bifunctional monomers having two polymerizable functional groups, and monofunctional monomers having one polymerizable functional group. The monomer contained in the mixed monomer mixture at a ratio of 5 mol% or more (particularly, a monomer or mixed monomer contained in the mixed monomer mixture at a ratio of 4 mol% or more, 3 mol% or more, 2 mol% or more, 1 mol% or more, 0.5 mol% or more, or 0.1 mol% or more) contains tricyclodecane dimethanol diacrylate or tricyclodecane dimethanol dimethacrylate, and further contains a monofunctional monomer having one polymerizable functional group.The monomer contained in the mixed monomer mixture at a ratio of 5 mol % or more (particularly, a monomer contained in the mixed monomer mixture at a ratio of 4 mol % or more, 3 mol % or more, 2 mol % or more, 1 mol % or more, 0.5 mol % or more, or 0.1 mol % or more, or the mixed monomer) comprises n-stearyl acrylate or 2-orthophenylphenoxyethyl acrylate. The monomer contained in the mixed monomer mixture at a ratio of 5 mol % or more (particularly, a monomer contained in the mixed monomer mixture at a ratio of 4 mol % or more, 3 mol % or more, 2 mol % or more, 1 mol % or more, 0.5 mol % or more, or 0.1 mol % or more, or the mixed monomer) comprises n-stearyl acrylate or 2-orthophenylphenoxyethyl acrylate, and further comprises pentaerythritol triacrylate, pentaerythritol tetraacrylate, or trimethylolpropane triacrylate. - Monomers contained in the mixed monomer mixture at a ratio of 5 mol% or more (particularly, monomers contained in the mixed monomer mixture at a ratio of 4 mol% or more, 3 mol% or more, 2 mol% or more, 1 mol% or more, 0.5 mol% or more, or 0.1 mol% or more, or monomers constituting the mixed monomer) all have an evaporation temperature of 100°C to 200°C. - Monomers contained in the mixed monomer mixture at a ratio of 5 mol% or more (particularly, monomers contained in the mixed monomer mixture at a ratio of 4 mol% or more, 3 mol% or more, 2 mol% or more, 1 mol% or more, 0.5 mol% or more, or 0.1 mol% or more, or monomers constituting the mixed monomer) all have an evaporation temperature of 120°C to 160°C.

[0142] (Applications) The applications of the present capacitor are not particularly limited, but the present capacitor is particularly suitable for applications in high temperature environments (environments of 105° C. or higher).

[0143] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0144] <<Examples 1 and 2 and Comparative Examples 1 and 2>> Thin-layer polymer multilayer capacitors according to Examples 1 and 2 and Comparative Examples 1 and 2 were manufactured, and their characteristics were evaluated.

[0145] <Materials> The monomer materials used in the examples and comparative examples are shown below:

[0146] (Monofunctional Monomer) 2-(biphenyl-2-yloxy)-ethyl acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: A-LEN-10) n-Stearyl acrylate (manufactured by Kyoeisha Chemical Co., Ltd., product name: Light Acrylate S-A) n-Stearyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd., product name: Light Ester S)

[0147] (Bifunctional Monomer) Tricyclodecane dimethanol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: A-DCP)

[0148] (Trifunctional monomer) Triallyl isocyanurate (manufactured by Shinryo Corporation, product name: Taiku (registered trademark))

[0149] (Mixture of trifunctional and tetrafunctional monomers) Pentaerythritol (tri / tetra)acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: A-TMM-3L) (Wherein, R- is OH- or CH ２ =C(H)-C(O)-O-, and the proportion of OH- is approximately 60%.

[0150] The measurement methods used in the examples and comparative examples are explained below.

[0151] <FT-IR Analysis> FT-IR (Fourier transform infrared spectroscopy) was used to evaluate the uniformity of the polymer structure (uniformity of the composition of polymer structural units) of the resin thin film layers constituting the capacitor laminate.

[0152] Specifically, the chemical compositions of the "initial layer" and the "final layer" constituting the laminate were investigated as follows: (a) Measurement samples of the "initial layer" and the "final layer" were taken from the laminate. (b) A Fourier transform infrared spectrophotometer was used as the analyzer. The FT-IR spectrum in the ATR mode (attenuated total reflection measurement method) was converted to absorbance. The C=O stretching vibration peak of the acrylic group (1725 cm －１ (c) The "converted peak height" of each peak derived from each target monomer was calculated by multiplying the height of the C=O stretching vibration peak of the acrylic group (around 1725 cm) by the "converted peak height" of each peak derived from each target monomer by the "converted peak height" ... －１ (d) It was confirmed whether there was a change in the converted peak height derived from the target monomer between the "initial phase" sample and the "final phase" sample.

[0153] The uniformity of the polymer structure using FT-IR was evaluated according to the following criteria: "Good" = No monomer species showing a clear decrease in peak between the initial layer and the final layer was confirmed. "Poor" = Monomer species showing a clear decrease in peak between the initial layer and the final layer was confirmed.

[0154] The laminate from which the sample was taken has a structure in which resin thin film layers (i.e., polymer layers formed by curing a monomer) and metal thin film layers are alternately laminated. The "initial layer" constituting the laminate refers to a resin thin film layer formed early in the laminate manufacturing process and laminated near the surface of the rotating drum. The "final layer" refers to a resin thin film layer formed late in the laminate manufacturing process and positioned away from the surface of the rotating drum.

[0155] When a change in the converted peak height due to the target monomer is observed, it indicates that the polymer structure of the thin resin layer in the laminate is not uniform.

[0156] For reference, the peak positions (cm) characteristic of each monomer in FT-IR analysis are shown. －１) are shown below: 2-(biphenyl-2-yloxy)-ethyl acrylate: around 3063, around 1600 n-stearyl acrylate: around 722 n-stearyl methacrylate: around 722 triallyl isocyanurate: around 1692, around 1456 pentaerythritol (tri / tetra)acrylate: around 3520

[0157] <Evaporation Temperature> The evaporation temperature of each monomer contained in the mixed monomer was measured using a gravimetric differential thermal analyzer as follows: 1. 10 mg of the monomer was collected as a measurement sample and set in a gravimetric differential thermal analyzer (TG-DTA: Q-600 manufactured by TA Instruments). 2. The measurement environment was reduced to 5 to 10 Pa using a rotary pump and maintained at this pressure. 3. The temperature was increased to 300°C at a rate of 20°C / min, and the weight change was measured. 4. In a graph obtained by plotting the weight change against the temperature, the temperature at which the slope of the curve was greatest in the decreasing direction (the temperature at which the rate of weight loss was greatest) was identified and defined as the evaporation temperature.

[0158] Example 1 In Example 1, a capacitor was manufactured and evaluated as follows.

[0159] (Manufacturing of Thin Film Polymer Multilayer Capacitor) In a vacuum chamber, the process of forming a resin thin film layer and the process of forming a metal thin film layer were alternately repeated on a rotating drum to produce a laminate (laminated body) in which a total of 2830 resin thin film layers and metal thin film layers (internal electrode metal layers) were alternately stacked on the rotating drum.

[0160] In the process of forming the resin thin film layer, a mixture of the following monomers was used (the numbers in parentheses indicate the molar ratio): 2-(biphenyl-2-yloxy)-ethyl acrylate (50) Tricyclodecane dimethanol diacrylate (50)

[0161] (Monomer Vapor Deposition) In the process of forming the resin thin film layer, the monomer mixture was vaporized by vapor deposition in a vacuum chamber. Specifically, in an evaporator flowing through the vacuum chamber, the monomer mixture was vaporized by dropping it onto the upstream inclined plate of an inclined plate (oil circulation type) heated to 170°C, and the vaporized monomer was sent to the vacuum chamber.

[0162] The dropped mixed monomer was vaporized while flowing down the upstream inclined plate and the downstream inclined plate. The remaining monomer that was not vaporized on the inclined plate and the monomer that had aggregated on the inner wall of the evaporator were collected in a collection tank installed downstream of the inclined plate. The inner wall of the evaporator was heated to 230°C.

[0163] (Curing Treatment) After forming the monomer layer, the monomer layer was irradiated with an electron beam to cure the monomer layer, thereby forming a resin thin film layer. The electron beam irradiation was performed under the conditions of an acceleration voltage of 4 kV and an irradiation current of 35 mA. The thickness of the resin thin film layer was 0.5 μm.

[0164] (Metal Vapor Deposition) In the process of forming the metal thin film layer, aluminum (Al) was vapor-deposited on the resin thin film layer, which had been partially masked by vapor-depositing fluorine oil, to form the metal thin film layer. The vapor deposition resistance of the metal thin film layer was 8 Ω / □.

[0165] (Planarization and Cutting of Laminate Base) The manufactured laminate base was removed from the rotating drum and flattened by pressing under heat at 160°C. The flattened laminate base was then cut into sticks, which were then heat-treated at 240°C in a reduced pressure environment of 100 Pa or less. External electrodes (brass metallicon thermal spray, copper plating, and tin plating) were then attached, and the resulting pieces were further cut into chips, thereby obtaining a thin-film polymer multilayer capacitor according to Example 1. The capacitor size was 45 mm x 32 mm.

[0166] The FT-IR analysis results and the monomer composition of the resin thin film layer according to Example 1 are shown in Table 1 below.

[0167] Example 2 A capacitor according to Example 2 was manufactured and evaluated in the same manner as in Example 1, except that a mixture of the following monomers (numbers in parentheses indicate molar ratios) was used. The results are shown in Table 1 below: n-Stearyl acrylate (22.5) Tricyclodecane dimethanol diacrylate (67.5) Pentaerythritol (tri / tetra)acrylate (10)

[0168] The FT-IR analysis results of Example 2 are shown in Figure 2 (initial layer) and Figure 3 (final layer). In the figures, the white arrow indicates the C=O stretching vibration peak of the acryloyl group. The solid arrow indicates the peak derived from pentaerythritol (tri / tetra)acrylate.

[0169] As can be seen from FIGS. 2 and 3, no change was observed between the initial and final lipid thin film layers with respect to the peaks derived from pentaerythritol (tri / tetra)acrylate.

[0170] <Comparative Example 1> A capacitor according to Comparative Example 1 was manufactured and evaluated in the same manner as in Example 1, except that a mixture of the following monomers (numbers in parentheses indicate molar ratios) was used. The results are shown in Table 1 below. 2-(biphenyl-2-yloxy)-ethyl acrylate (45) Tricyclodecane dimethanol diacrylate (45) Triallyl isocyanurate (10)

[0171] The FT-IR analysis results of Comparative Example 1 are shown in Figure 4 (initial layer) and Figure 5 (final layer). In the figures, the white arrows correspond to the C=O stretching vibration peak of the acryloyl group. The dotted arrows indicate the peak derived from triallyl isocyanurate, and the solid arrows indicate the peak derived from 2-(biphenyl-2-yloxy)-ethyl acrylate.

[0172] 4 and 5, the peaks derived from triallyl isocyanurate in the final resin thin film layer are clearly reduced compared to the peaks derived from triallyl isocyanurate in the initial resin thin film layer, and no such change was observed for the peaks derived from 2-(biphenyl-2-yloxy)-ethyl acrylate.

[0173] Comparative Example 2 A capacitor according to Comparative Example 2 was produced and evaluated in the same manner as in Example 1, except that a mixture of the following monomers (numbers in parentheses indicate molar ratios) was used. The results are shown in Table 1 below: n-Stearyl acrylate (19) Tricyclodecane dimethanol diacrylate (76) Triallyl isocyanurate (5)

[0174]

[0175] In Table 1, the evaporation temperature difference "Ta-Tb" indicates the difference in evaporation temperature between the monomer having the highest evaporation temperature Ta and the monomer having the lowest evaporation temperature Tb among the mixed monomers. "FT-IR evaluation" indicates the evaluation results of the uniformity of the polymer structure based on FT-IR analysis in the initial layer (the layer deposited early in the manufacturing process) and the final layer (the layer deposited late in the manufacturing process) of the resin thin film layer.

[0176] As can be seen from Table 1, when the difference in evaporation temperature between the monomers constituting the polymer structure of the resin thin film layer (each monomer in the mixed monomer used in the manufacturing process) was relatively small, at 4 to 18°C, the resin thin film layer had a relatively uniform polymer structure (Examples 1 and 2).

[0177] In contrast, when the difference in the evaporation temperature of the monomers was relatively large, 29 to 43° C., the uniformity of the polymer structure of the resin thin film layer was relatively low (Comparative Examples 1 and 2).

[0178] <<Reference Examples 1 and 2>> In Reference Examples 1 and 2, the evaporation behavior of mixed monomers having various compositions in an evaporator was investigated. In these Reference Examples 1 and 2, cases were investigated in which the difference in evaporation temperature (Ta - Tb) between the monomer having the highest evaporation temperature and the monomer having the lowest evaporation temperature was greater than 20°C.

[0179] Reference Example 1 In Reference Example 1, a mixed monomer containing the following monomers was used (numbers in parentheses indicate molar ratios): 2-(biphenyl-2-yloxy)-ethyl acrylate (22.5) Tricyclodecane dimethanol diacrylate (67.5) Triallyl isocyanurate (10)

[0180] The mixed monomer was dropped onto an inclined plate in an evaporator, which was heated to 200° C. The evaporator had two inclined plates, an upstream inclined plate and a downstream inclined plate, and the mixed monomer was dropped onto the upstream inclined plate.

[0181] The mixed monomers dropped onto the inclined plate are heated and vaporized by the inclined plate, and some of them harden, forming a jelly-like or solid polymer residue on the plate. Monomers also adhere to the surface of this residue. The composition of these residues before dropping, on the upstream inclined plate, the downstream inclined plate, and in the recovery tank was analyzed using FT-IR analysis. The results are shown in Table 2 below.

[0182] Reference Example 2 In Reference Example 2, a mixed monomer containing the following monomers (numbers in parentheses indicate molar ratios) was used, and the same evaluation as in Reference Example 1 was carried out. The results are shown in Table 2 below: n-Stearyl acrylate (19) Tricyclodecane dimethanol diacrylate (76) Triallyl isocyanurate (5)

[0183]

[0184] In Table 2, the evaporation temperature difference "Ta-Tb" indicates the difference in evaporation temperature between the monomer having the highest evaporation temperature and the monomer having the lowest evaporation temperature among the mixed monomers. In addition, "FT-IR evaluation" indicates the difference in evaporation temperature between the C=O stretching vibration peak of the acryloyl group (1725 cm) in the FT-IR analysis. －１ The peak derived from triallyl isocyanurate (isocyanurate ring > C=O stretching vibration, 1695 cm －１ The higher this ratio, the higher the proportion of triallyl isocyanurate in the mixed monomers.

[0185] As can be seen in Table 2, the triallyl isocyanurate ratio at the upstream inclined plate is reduced compared to before dripping. Furthermore, the triallyl isocyanurate ratio at the downstream inclined plate is zero, indicating that triallyl isocyanurate has already evaporated completely in the mixed monomer that has reached the downstream inclined plate. This indicates that monomers with relatively low evaporation temperatures (110°C) evaporated preferentially over other monomers with relatively high evaporation temperatures (135-139°C), and their ratio in the mixed monomer decreased and eventually became zero. A constant triallyl isocyanurate ratio was observed in the recovery tank, which is thought to be due to some of the evaporated monomer condensing and liquefying on the inner walls of the evaporator before flowing into the recovery tank.

[0186] 1 Thin film polymer multilayer capacitor 2 Laminate 3, 4 External electrodes

Claims

1. A thin film polymer multilayer capacitor having a laminate 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 formed by polymerizing two or more types of monomers, and among the two or more types of monomers, for monomers that form 5 mol % or more of structural units in the polymer structure, the difference in evaporation temperature Ta - Tb between the monomer having the highest evaporation temperature Ta and the monomer having the lowest evaporation temperature Tb is 20°C or less.

2. The capacitor according to claim 1, wherein the difference in evaporation temperature Ta-Tb is 15°C or less.

3. The capacitor according to claim 1, wherein the difference in evaporation temperature Ta-Tb is 10°C or less.

4. A capacitor according to any one of claims 1 to 3, wherein among the two or more types of monomers, monomers that form 5 mol % or more of structural units in the polymer structure each have at least one polymerizable functional group selected from the group consisting of an acryloyl group, a methacryloyl group, an allyl group, and a vinyl group.

5. A capacitor according to any one of claims 1 to 3, wherein the two or more types of monomers that form 5 mol% or more of structural units in the polymer structure include a bifunctional monomer having two polymerizable functional groups and a monofunctional monomer having one polymerizable functional group.

6. A capacitor according to any one of claims 1 to 3, wherein the two or more types of monomers that form 5 mol% or more of structural units in the polymer structure include a trifunctional or higher monomer having three or more polymerizable functional groups, a bifunctional monomer having two polymerizable functional groups, and a monofunctional monomer having one polymerizable functional group.

7. A capacitor according to any one of claims 1 to 3, wherein the two or more monomers that form 5 mol % or more of structural units in the polymer structure include tricyclodecane dimethanol diacrylate or tricyclodecane dimethanol dimethacrylate, and further include a monofunctional monomer having one polymerizable functional group.

8. The capacitor according to any one of claims 1 to 3, wherein, of the two or more monomers, a monomer that forms 5 mol % or more of structural units in the polymer structure includes n-stearyl acrylate or 2-orthophenylphenoxyethyl acrylate.

9. The capacitor according to claim 8, wherein the monomers forming 5 mol % or more of constitutional units in the polymer structure among the two or more monomers further include pentaerythritol triacrylate, pentaerythritol tetraacrylate, or trimethylolpropane triacrylate.

10. A capacitor according to any one of claims 1 to 3, wherein among the two or more types of monomers, all of the monomers that form 5 mol % or more of structural units in the polymer structure have evaporation temperatures of 100°C to 200°C under conditions of 1 Pa to 10 Pa.

11. The capacitor according to any one of claims 1 to 3, wherein among the two or more types of monomers, monomers that form 5 mol % or more of structural units in the polymer structure all have evaporation temperatures of 120°C to 160°C under conditions of 1 Pa to 10 Pa.

12. A method for manufacturing a thin film polymer multilayer capacitor having a laminate 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 formed by vapor deposition of a monomer mixture containing two or more types of monomers; forming an internal electrode metal layer by vapor deposition of metal on the resin thin film layer; and forming the laminate by alternately repeating the formation of the resin thin film layer and the internal electrode metal layer, wherein, for monomers contained in the monomer mixture that account for 5 mol% or more of the two or more types of monomers, the difference in evaporation temperature Ta - Tb between the monomer having the highest evaporation temperature Ta and the monomer having the lowest evaporation temperature Tb is 20°C or less.

13. The method of claim 12, comprising contacting the mixed monomers with a heated inclined plate when forming the monomer layer.

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