Thin film polymer multilayer capacitor and method for manufacturing same

Abstract

The purpose of the present disclosure is to provide a thin film polymer multilayer capacitor which has relatively reduced water absorption properties and good electrical characteristics, and in which an increase in tanδ at high temperatures is suppressed. The present disclosure relates to a thin film polymer multilayer capacitor that has a structure in which resin thin film layers and internal electrode metal layers are alternately stacked. In this capacitor, the resin thin film layers each have a polymer structure that is obtained by polymerizing a first monomer that is a monofunctional monomer, a second monomer that is a bifunctional monomer, and a third monomer that is a trifunctional or higher polyfunctional monomer.

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] A capacitor having a structure in which dielectric layers containing resin and electrode layers containing metal are alternately laminated is known. In manufacturing such a thin-film polymer multilayer capacitor, the resin thin film layers are often formed using a monomer having an acrylic group or a methacrylic group (e.g., an acrylate monomer or a methacrylate monomer).

[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. It states that the resin material is preferably one containing an acrylate resin or a vinyl resin as a main component. In the examples, it describes the use of dicyclopentadiene dimethanol diacrylate.

[0006] Patent Document 4 describes a method for manufacturing a capacitor in which dielectric resin layers and electrode metals are alternately laminated on a cooling roll in a vacuum to form a rolled laminate, the rolled laminate is removed from the cooling roll and divided into curved laminates, and the curved laminates are heat-treated while being pressurized. According to this document, the dielectric resin may be thermosetting. In the examples, it is described that dimethyloltricyclodecane diacrylate and 1,9-nonanediol diacrylate are used for the resin layers.

[0007] Patent Document 5 describes a method for manufacturing a capacitor, in which the number of layers to be stacked is determined during stacking depending on the stacking status up to that point. In the examples, it describes the use of dicyclopentadiene dimethanol diacrylate as the resin layer material.

[0008] Patent Document 6 describes a capacitor having a dielectric made by polymerizing a divinyl compound that does not contain a polar group. In the examples, it describes that a dielectric film is formed by a high-frequency sputtering method using 1,6-divinylnaphthalene as a sputtering target.

[0009] Patent Document 7 describes a laminated film capacitor, which has a dielectric formed from a compound having at least two functional groups selected from allyloxy groups and vinyloxy groups, either alone or in combination, represented by a specific general formula. In the examples, it describes that the dielectric layer is formed using 1,9-divinyloxynonane.

[0010] Patent Document 8 describes a method for manufacturing a capacitor, in which the resin in each layer is cured to a residual vinyl group ratio of 40 to 20%, and then the laminate is removed from the cooling roll and heat-treated under pressure and heat. In the examples, it describes the use of dimethyloltricyclodecane diacrylate, 1,9-nonanediol diacrylate, and cyclohexanedimethylol divinyl ether, either alone or in combination.

[0011] International Publication No. 2015 / 118693 JP 60-157106 A JP 2002-75776 A JP 2000-348966 A JP 2000-003830 A JP 2003-151849 A JP 11-040451 A JP 10-321461 A

[0012] Typically, in thin-film polymer multilayer capacitors, bifunctional acrylate or methacrylate monomers are used as the dielectric polymer (resin thin-film layer) material, such as tricyclodecane dimethanol diacrylate and tricyclodecane dimethanol dimethacrylate.

[0013] These difunctional (meth)acrylate monomers are characterized by good radiation curability and ease of handling, but are inferior to conventional dielectrics using polypropylene in terms of water absorption and dielectric loss tangent (tan δ).

[0014] In this regard, it is conceivable that the bifunctional monomer used in the dielectric polymer of the thin-film polymer multilayer capacitor may contain a monofunctional monomer, thereby improving water absorption and suppressing an increase in tan δ (at room temperature).

[0015] However, in such capacitors having a resin thin film layer formed from a mixture of a bifunctional monomer and a monofunctional monomer, a problem was found in that tan δ increased significantly at high temperatures, and capacitance also increased at high temperatures.

[0016] An object of the present invention is to provide a thin film polymer multilayer capacitor that has relatively low water absorption, good electrical properties, and suppressed increase in tan δ at high temperatures.

[0017] The above-described 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 formed by polymerizing a first monomer that is a monofunctional monomer, a second monomer that is a bifunctional monomer, and a third monomer that is a trifunctional or higher polyfunctional monomer. <Aspect 2> The capacitor according to Aspect 1, wherein in the polymer structure of the resin thin film layers, a ratio M3 / (M1+M2+M3) of the molar amount M3 of the monomer units derived from the third monomer to the sum of M1 of the monomer units derived from the first monomer, M2 of the monomer units derived from the second monomer, and M3 of the monomer units derived from the third monomer is 0.01 to 0.3. <Aspect 3> The capacitor according to Aspect 1 or 2, wherein the third monomer is a trifunctional monomer. <Aspect 4> The capacitor according to any one of Aspects 1 to 3, wherein the third monomer includes a monomer having an allyl group. <Aspect 5> The capacitor according to any one of aspects 1 to 4, wherein the third monomer comprises triallyl isocyanurate. <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 comprises a monomer having an acrylic group or a methacrylic group. <Aspect 7> The capacitor according to any one of aspects 1 to 6, wherein the first monomer comprises 2-(biphenyl-2-yloxy)-ethyl acrylate, 4-phenylbenzyl acrylate, stearyl acrylate, or stearyl methacrylate, and / or the second monomer comprises tricyclodecane dimethanol diacrylate or tricyclodecane dimethanol dimethacrylate. <Aspect 8> The capacitor according to any one of aspects 1 to 7, wherein the capacitor has a tan δ of less than 2.0% when measured at 105°C and 1 kHz.A method for producing a thin-film polymer multilayer capacitor having a laminate 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 monofunctional monomer, a second monomer which is a bifunctional monomer, and a third monomer which is a trifunctional or higher polyfunctional monomer; forming an internal electrode metal layer by evaporating metal on the resin thin film layer; and forming the laminate structure by alternately repeating the formation of the resin thin film layer and the formation of the internal electrode metal layer. A method for producing a capacitor according to Aspect 9, wherein a ratio m3 / (m1 + m2 + m3) of the molar amount m3 of the third monomer to the sum of the molar amount m1 of the first monomer, the molar amount m2 of the second monomer, and the molar amount m3 of the third monomer is 0.01 to 0.3. A method according to Aspect 9 or 10, further comprising heating the laminate structure to promote curing of uncured components in the resin thin film layer. The method according to any one of aspects 9 to 12, wherein the resin thin film layer and the internal electrode metal layer are formed by vapor deposition. The method according to any one of aspects 9 to 12, wherein the mixture of the first monomer and the second monomer, and the third monomer are vapor deposited from separate evaporation sources when the monomer layer is formed.

[0018] According to the present invention, it is possible to provide a thin film polymer multilayer capacitor having relatively low water absorption, good electrical properties, and suppressed increases in tan δ at high temperatures. According to the present invention, it is also possible to suppress fluctuations in capacitance at high temperatures.

[0019] In particular, the present invention can provide a thin-film polymer multilayer capacitor that has relatively reduced water absorption, good electrical properties, and suppressed increases in tan δ at high temperatures, and further has good EB curability (electron beam curability) and sufficient flexibility.

[0020] Fig. 1 is a perspective view of a thin-film polymer multilayer capacitor. Fig. 2 is a graph showing the results of measuring tan δ at various temperatures for the capacitors according to the example and the comparative example. Fig. 3 is a graph showing the results of measuring the capacitance change rate (%) at various temperatures for the capacitors according to the example and the comparative example.

[0021] <<Thin Film Polymer Multilayer Capacitor>> The thin film polymer multilayer capacitor according to the present invention is a thin film polymer multilayer capacitor having a structure in which resin thin film layers and internal electrode metal layers are alternately laminated, and the resin thin film layers have a polymer structure obtained by polymerizing a first monomer which is a monofunctional monomer, a second monomer which is a bifunctional monomer, and a third monomer which is a trifunctional or higher polyfunctional monomer.

[0022] As described above, by incorporating a monofunctional monomer into the bifunctional monomer used in the dielectric polymer (resin thin film layer) of a thin film polymer multilayer capacitor, it is possible to improve water absorption and also improve electrical properties, for example, reduce tan δ (at room temperature).

[0023] On the other hand, as described above, it has been found that in capacitors having a resin thin film layer formed from a mixture of a bifunctional monomer and a monofunctional monomer, tan δ at high temperatures can increase significantly, and the capacitance also increases significantly.

[0024] Although there is no intention to be limited by theory, it is believed that mixing a monofunctional monomer reduces the density of the network structure (crosslinks) in the polymer, thereby increasing the dielectric tangent (tan δ) and capacitance in a high temperature environment.

[0025] In such cases, the capacitor characteristics may fluctuate greatly with temperature, and heat generation due to AC current may increase at high temperatures, limiting the applications in which the capacitor can be used. In particular, there are many high-voltage applications in which large currents flow, making them unsuitable for use.

[0026] In contrast, the thin-film polymer multilayer capacitor of the present invention uses a tri- or higher functional monomer in addition to the monofunctional and bifunctional monomers, which makes it possible to suppress the increase in the dielectric loss tangent (tan δ) at high temperatures and also to suppress the fluctuation (increase) in capacitance at high temperatures.Furthermore, the thin-film polymer multilayer capacitor of the present invention has the advantage of reduced water absorption and reduced dielectric loss tangent at room temperature compared to conventional capacitors that use only bifunctional monomers.

[0027] Although there is no intention to be limited by theory, in the present invention, since a monofunctional monomer and a tri- or higher functional monomer are added to a bifunctional monomer, it is thought that the monofunctional monomer has the effect of reducing water absorption and dielectric loss tangent in the normal temperature range, and that the tri- or higher functional monomer improves the crosslink density, thereby suppressing an increase in dielectric loss tangent in the high temperature range.

[0028] In the present disclosure, the "dielectric loss tangent in the normal temperature range (normal temperature range tan δ)" particularly means tan δ measured at 25°C and 1 kHz. Furthermore, the "dielectric loss tangent in the high temperature range (high temperature range dielectric loss tangent)" particularly means tan δ measured at 105°C and 1 kHz.

[0029] The methods according to the present disclosure are described in more detail below.

[0030] <Resin thin film layer> The resin thin film layer has a polymer structure, and this polymer structure has a monomer unit derived from a first monomer (first monomer unit), a monomer unit derived from a second monomer (second monomer unit), and a monomer unit derived from a third monomer (third monomer unit). The first monomer, the second monomer, and the third monomer may each independently consist of a single monomer or may contain multiple types of monomers. In a preferred embodiment, the first monomer, the second monomer, and the third monomer each consist of a single monomer.

[0031] (Polymerizable Functional Group) A monofunctional monomer has one polymerizable functional group in one molecule. A bifunctional monomer has two polymerizable functional groups in one molecule. A trifunctional or higher functional monomer has three or more polymerizable functional groups in one molecule.

[0032] Examples of the polymerizable functional group include a vinyl group, an acrylonitrile group, an isopropenyl group, and an epoxy group.

[0033] The vinyl group is CH ２ ═CH—. Specific examples of the polymerizable functional group include an acrylic group (CH ２ ═CH—C(═O)), methacryl group (CH ２ =C(CH ３ )-C(=O)), 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 a benzene ring. R particularly contains 2 to 8, more particularly 2 to 4, carbon atoms.

[0034] Monofunctional monomers, difunctional monomers, and trifunctional or higher polyfunctional monomers can be polymerized via polymerizable functional groups under conditions such as electron beam irradiation to form a macromolecular structure (polymer).

[0035] Preferably, the proportion of the first monomer unit (molar amount M1), the second monomer unit (molar amount M2), and the third monomer unit (molar amount M3) in all monomer units constituting the polymer structure of the resin thin film layer is, in molar ratio, 80% or more, 85% or more, 90% or more, or 95% or more, and particularly preferably 100%.

[0036] (Proportion of Third Monomer Units) Preferably, in the polymer structure of the resin thin layer film, the ratio M3 / (M1+M2+M3) of the molar amount M3 of the monomer units derived from the third monomer to the sum of M1, M2, and M3, is 0.01 to 0.3.

[0037] When the molar ratio of the third monomer unit is 0.01 or more, particularly 0.05 or more, a better suppression effect against the increase in the dielectric loss tangent at high temperatures can be obtained. The higher this molar ratio, the more pronounced the suppression effect against the increase in the dielectric loss tangent at high temperatures. A similar suppression effect against the capacity fluctuation at high temperatures can also be obtained.

[0038] When the molar ratio of the third monomer unit is 0.3 or less, particularly good results can be obtained in terms of reducing water absorption and / or reducing tan δ at room temperature. In this case, particularly good mechanical properties of the resin thin film layer can be obtained, and particularly good curability (especially curability by electron beam curing or photocuring) can be obtained.

[0039] This molar ratio of the third monomer unit may more preferably be 0.02 or more, 0.04 or more, 0.05 or more, or 0.08 or more, and / or 0.28 or less, 0.26 or less, 0.24 or less, 0.22 or less, 0.20 or less, 0.18 or less, 0.16 or less, 0.14 or less, or 0.12 or less. This molar ratio of the third monomer unit may more preferably be, for example, 0.05 to 0.2, or even 0.07 to 0.15. Note that when the third monomer contains a monomer having a relatively high polarity, such as an acrylic group or a methacrylic group, it is more preferable that the amount of the third monomer unit is relatively reduced in order to prevent an excessive increase in the water absorption rate and room temperature tan δ of the capacitor. In this case, for example, the molar ratio M3 / (M1+M2+M3) may be 0.01 to 0.12, 0.01 to 0.09, or even 0.01 to 0.07.

[0040] The molar proportion of the third monomer unit is preferably lower than the molar proportion of the first monomer. The ratio M1 / M3 of the molar amount M1 of the monomer unit derived from the first monomer to the molar amount M3 of the monomer unit derived from the third monomer is preferably 1.2 to 6.0, more preferably 2.0 to 5.0, and even more preferably 2.5 to 4.5.

[0041] (Proportion of First Monomer Unit) In the polymer structure of the resin thin layer film, the molar ratio M1 / (M1+M2+M3) of the molar amount M1 of the first monomer unit to the sum of the molar amount M1 of the first monomer unit, the molar amount M2 of the second monomer unit, and the molar amount M3 of the third monomer unit may be 0.1 to 0.6.

[0042] This molar ratio of the first monomer units is preferably between 0.2 and 0.5, or even between 0.4 and 0.5.

[0043] (Proportion of Second Monomer Unit) In the polymer structure of the resin thin layer film, the molar ratio M2 / (M1+M2+M3) of the molar amount M2 of the second monomer unit to the sum of the molar amount M1 of the first monomer unit, the molar amount M2 of the second monomer unit, and the molar amount M3 of the third monomer unit may be 0.2 to 0.8.

[0044] This molar ratio of the second monomer unit is preferably between 0.3 and 0.7, or even between 0.4 and 0.6.

[0045] (Monofunctional Monomer) The monofunctional monomer preferably includes a monomer having an acrylic group or a methacrylic group, or consists of a monomer having an acrylic group or a methacrylic group. The monofunctional monomer most preferably includes a monomer having an acrylic group, or consists of a monomer having an acrylic group.

[0046] In one embodiment according to the present disclosure, the monofunctional monomer can have a chemical structure represented by the following general formula (1):

[0047]

[0048] In formula (1), R ３ is a group containing 1 to 20 carbon atoms; R ２ is H or CH ３ is.

[0049] R in formula (1) ２ is preferably H.

[0050] R in formula (1) ３ preferably contains 3 to 20, more preferably 6 to 20, and even more preferably 8 to 20 carbon atoms.

[0051] R in formula (1) 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.

[0052] 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.

[0053] Preferably, R in formula (1) ３ consists of carbon and hydrogen atoms, and optionally oxygen atoms.

[0054] In formula (1), R ３ can contain aliphatic (linear or branched) moieties, alicyclic moieties, and / or aromatic moieties.

[0055] 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.

[0056] 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.

[0057] R ３Particularly preferably, has a biphenyl structure.

[0058] In formula (1), 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.

[0059] Examples of the compound structures S1 to S8 of the monofunctional monomers that can be used in the present invention are shown below.

[0060]

[0061] 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.

[0062] In the chemical formulas S5 and S6, n may be 1 to 20, preferably 5 to 18, and more preferably 12 to 17.

[0063] 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.

[0064] Examples of preferred compound structures of monofunctional monomers are shown below.

[0065]

[0066] Particularly preferred monofunctional monomers include 2-(biphenyl-2-yloxy)-ethyl acrylate, 4-phenylbenzyl acrylate, stearyl acrylate (particularly n-stearyl acrylate), and stearyl methacrylate (particularly n-stearyl methacrylate).

[0067] (Bifunctional Monomer) The bifunctional monomer preferably comprises a monomer having an acrylic group or a methacrylic group, or consists of a monomer having an acrylic group or a methacrylic group, and most preferably comprises a monomer having an acrylic group, or consists of a monomer having an acrylic group.

[0068] In one embodiment according to the present disclosure, the bifunctional monomer can have a chemical structure represented by the following general formula (2):

[0069]

[0070] In formula (2), R １ is a group containing 1 to 20 carbon atoms; R ２ are each independently H or CH ３ is.

[0071] In formula (2), R １ preferably contains 3 to 20, more preferably 6 to 20, and even more preferably 8 to 20 carbon atoms.

[0072] 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.

[0073] 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.

[0074] Preferably, R in formula (2) １ consists of carbon and hydrogen atoms, and optionally oxygen atoms.

[0075] In formula (2), R １ can contain aliphatic (linear or branched) moieties, alicyclic moieties, and / or aromatic moieties.

[0076] R in formula (2) １When 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.

[0077] 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.

[0078] 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.

[0079] Examples of the compound structures M1 to M6 of the bifunctional monomer that can be used in the present invention are shown below.

[0080]

[0081] 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.

[0082] 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.

[0083] Particularly preferred bifunctional monomers include: tricyclodecane dimethanol diacrylate, tricyclodecane dimethanol dimethacrylate.

[0084] (Third Monomer)

[0085] In one embodiment according to the present disclosure, the trifunctional or higher polyfunctional monomer may include a monomer having an acrylic group or a methacrylic group, or may consist of a monomer having an acrylic group or a methacrylic group, and in particular has a chemical structure represented by the following general formula (3):

[0086]

[0087] 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 to 6.

[0088] In formula (3), n is preferably 3 or 4, and more preferably 3.

[0089] In formula (3), R ４ preferably contains 1 to 20, more preferably 2 to 12, and even more preferably 3 to 8 carbon atoms.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] In formula (3), R４ can contain aliphatic (linear or branched) moieties, alicyclic moieties, and / or aromatic moieties.

[0094] 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.

[0095] Among the compounds represented by the above formula (3), the compound structure of trimethylolpropane triacrylate is shown below as a preferred example of a polyfunctional monomer.

[0096]

[0097] (Trifunctional Monomer Having a Low-Polarity / Non-Polar Functional Group) In a particularly preferred embodiment of the present disclosure, the tri- or higher functional monomer includes a monomer having a polymerizable functional group other than an acrylic group or a methacrylic group, or consists of a monomer having a polymerizable functional group other than an acrylic group or a methacrylic group, wherein the polymerizable functional group is particularly a non-polar functional group.

[0098] The polymerizable functional group other than the acrylic and methacrylic groups preferably has a smaller polarity than the acrylic and methacrylic groups.

[0099] Examples of polymerizable functional groups having a polarity less than that of acrylic and methacrylic groups include allyl groups (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 a benzene ring. R particularly contains 2 to 8 carbon atoms, more particularly 2 to 4 carbon atoms.

[0100] An example of a tri- or higher functional monomer having an allyl group is triallyl isocyanurate (commercially available as "TAIC" (registered trademark)).

[0101]

[0102] When a monomer containing a polymerizable functional group (particularly an allyl group) having a polarity smaller than that of an acrylic group or a methacrylic group is used as the trifunctional or higher polyfunctional monomer, the effect of reducing the water absorption and / or dielectric loss tangent may be further enhanced, and an increase in the dielectric loss tangent at high temperatures may be further suppressed in some cases.

[0103] Although there is no intention to be limited by theory, in this case, it is thought that the inclusion of a tri- or higher functional monomer can increase the crosslink density of the resin, and that the increase in water absorption and the increase in room temperature range tan δ due to the mixing of a tri- or higher functional monomer can be suppressed.

[0104] Here, polymerizable functional groups with relatively low polarity (such as allyl groups) are generally considered to be less likely to undergo a curing reaction when exposed to electron beams or light. However, the present inventors have discovered that when these functional groups are mixed into a monomer that is cured by electron beams or light, a polymerization reaction occurs at a certain rate, and a crosslinked structure is formed by subsequent heat treatment or the like.

[0105] Therefore, by using a monomer containing a polymerizable functional group (particularly an allyl group) having a polarity less than that of an acrylic group or a methacrylic group as a trifunctional or higher polyfunctional monomer, it is thought that a high level of compatibility between high crosslink density, low tan δ, and low water absorption can be achieved in thin-film polymer laminate capacitors using monofunctional or bifunctional monomers having an acrylic group or a methacrylic group that are suitable for electron beam curing or photocuring.

[0106] It is believed that trifunctional or higher polyfunctional monomers can achieve even lower dielectric tangents and lower water absorption because they do not exhibit significant polarity in their molecular structures other than the polymerizable functional groups.

[0107] (Combination of Monomers) As the combination of the first to third monomers, the following combinations can be particularly mentioned: 2-(biphenyl-2-yloxy)-ethyl acrylate as a monofunctional monomer; tricyclodecane dimethanol diacrylate as a difunctional monomer; triallyl isocyanurate as a trifunctional monomer.

[0108] <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.

[0109] 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.

[0110] The thin film polymer multilayer capacitor can have 10 to 10,000 layers, 50 to 5000 layers, or 100 to 2,000 layers.

[0111] 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.

[0112] 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.

[0113] 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 / □.

[0114] (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.

[0115] 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.

[0116] (tan δ (25°C)) Preferably, the capacitor according to the present disclosure has a tan δ (also referred to as a dielectric dissipation factor 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, 0.85% 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.

[0117] Tan δ at 25° C. and 1 kHz can be measured using an LCR meter.

[0118] (Tan δ (High Temperature Region)) Furthermore, preferably, the capacitor according to the present disclosure has a tan δ of less than 2.0% when measured at 105°C and 1 kHz. This tan δ is more preferably 1.5% or less, and even more preferably 1.2% or less. The lower limit of this tan δ is not particularly limited, but may be 0.1% or more.

[0119] Tan δ at 105° C. and 1 kHz can be measured using an LCR meter.

[0120] (Water Absorption Rate) Preferably, the capacitor according to the present disclosure exhibits a water absorption rate of 0.2 to 0.9% when measured by the method described below. This water absorption rate is particularly 0.25 to 0.80%, more particularly 0.30 to 0.70%: A moisture absorption test is performed in which a capacitor from which external electrodes have been removed is placed in a constant temperature and humidity chamber at a temperature of 60°C and a relative humidity of 90%, and the capacitor is allowed to stand for 100 hours. After this, the weight change rate (%) of the capacitor is measured and this is defined as the water absorption rate (%) of the capacitor: Weight change rate (%) = 100 × (weight after moisture absorption test - weight before moisture absorption test) / weight before moisture absorption test.

[0121] Preferably, the capacitor according to the present disclosure exhibits a water absorption rate of 0.2 to 0.9% when measured using a resin sample by the following method, wherein the water absorption rate is particularly 0.25 to 0.80%, more particularly 0.30 to 0.70%: (a) providing a test monomer of the same type and composition as that used in forming the resin thin film layer of the capacitor, mixing a photoinitiator (2-benzyl-2-dimethylamino-4'morpholinobutyrophenone, manufactured by Tokyo Chemical Industry Co., Ltd.) in a ratio of 0.2±0.01 moles per 100 moles 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 at 120 W and a distance of 250 mm until polymerization stops, thereby producing a disk-shaped resin film having dimensions of 30 mm in diameter and 1 mm in depth. (b) A moisture absorption test was carried out in which the resin film as a resin sample was placed in a constant temperature and humidity chamber at a temperature of 60°C and a relative humidity of 90%, and the resin film was left to stand for 100 hours. The weight change rate of the resin film after the moisture absorption test was measured according to the following formula, and this was defined as the water absorption rate (%): Weight change rate (%) = 100 × (weight after moisture absorption test - weight before moisture absorption test) / weight before moisture absorption test.

[0122] <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.

[0123] 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.

[0124] 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.

[0125] (One aspect of the manufacturing method) The present disclosure includes a method for manufacturing a thin film polymer multilayer capacitor having a laminate structure in which resin thin film layers and internal electrode metal layers are alternately laminated, the method including: forming a resin thin film layer by curing a monomer layer containing a first monomer which is a monofunctional monomer, a second monomer which is a bifunctional monomer, and a third monomer which is a trifunctional or higher polyfunctional monomer; depositing a metal on the resin thin film layer to form an internal electrode metal layer; and alternately repeating the formation of the resin thin film layer and the formation of the internal electrode metal layer to form a laminate structure.

[0126] This manufacturing method according to the present disclosure is particularly suitable for manufacturing capacitors according to the present disclosure.

[0127] (Monomers) For details of each monomer and other components used in the manufacturing method according to the present disclosure, please refer to the above description of the capacitor according to the present disclosure. It is considered that the molar amount of the monomer used in the manufacturing process corresponds to the molar amount of the monomer unit in the formed resin thin film layer. Therefore, for the amount m1 (moles) of the first monomer, m2 (moles) of the second monomer, and m3 (moles) of the third monomer used in the manufacturing process, please refer to the above description of the molar amount M1 of the monomer unit derived from the first monomer, M2 of the monomer unit derived from the second monomer, and M3 of the monomer unit derived from the third monomer. That is, for m1 = M1, m2 = M2, and m3 = M3, please refer to the above description. Conversely, for M1, M2, and M3, please refer to the below description of m1, m2, and m3.

[0128] As described above, when only a bifunctional monomer is used, the water absorption rate and room temperature range tan δ of the capacitor may become relatively high.

[0129] In contrast, the incorporation of a monofunctional monomer is believed to contribute to suppressing the water absorption rate of the capacitor and reducing tan δ in the room temperature range. On the other hand, the use of a monofunctional monomer is believed to result in a relatively low crosslink density, which in turn leads to an increase in tan δ in the high temperature range.

[0130] It is believed that tri- or higher functional monomers can suppress an increase in tan δ in the high temperature range by increasing the crosslink density.

[0131] It is particularly preferable to use a tri- or higher functional monomer having a low polarity group or a non-polar group such as an allyl group, since this increases the crosslink density while minimizing the effect on the water absorption rate and room temperature range tan δ of the capacitor.

[0132] When using trifunctional or higher functional monomers with relatively high polarity, such as acrylic and methacrylic groups, it is preferable to reduce the amount of trifunctional or higher functional monomers to prevent excessive increases in the water absorption rate and room temperature tan δ of the capacitor. In this case, for example, the molar ratio m3 / (m1 + m2 + m3) below may be 0.01 to 0.12, 0.01 to 0.09, or even 0.01 to 0.07.

[0133] Preferably, the molar ratio m3 / (m1+m2+m3) of the amount of the third monomer m3 to the sum of the amount m1 (moles) of the first monomer, the amount m2 (moles) of the second monomer, and the amount m3 (moles) of the third monomer is 0.01 to 0.3. This molar ratio of the third monomer may more preferably be 0.02 or more, 0.04 or more, 0.05 or more, or 0.08 or more, and / or 0.28 or less, 0.26 or less, 0.24 or less, 0.22 or less, 0.20 or less, 0.18 or less, 0.16 or less, 0.14 or less, or 0.12 or less. This molar ratio of the third monomer unit may more preferably be, for example, 0.05 to 0.2, or even 0.07 to 0.15.

[0134] The molar ratio m1 / (m1+m2+m3) of the amount of the first monomer m1 (moles) to the sum of the amount m1 (moles) of the first monomer, the amount m2 (moles) of the second monomer, and the amount m3 (moles) of the third monomer may be from 0.1 to 0.6. This molar ratio of the first monomers is preferably from 0.2 to 0.5, or even from 0.4 to 0.5.

[0135] The molar ratio m2 / (m1+m2+m3) of the amount m2 of the second monomer to the sum of the amount m1 (moles) of the first monomer, the amount m2 (moles) of the second monomer, and the amount m3 (moles) of the third monomer may be from 0.2 to 0.8. This molar ratio of the second monomer is preferably from 0.3 to 0.7, or even from 0.4 to 0.6.

[0136] (Evaporation Temperature of Monomer in Reduced Pressure Environment) In a preferred embodiment according to the present disclosure, the temperature at which the evaporation rate is sufficiently high in an environment of 1.0 to 10.0 Pa is 120 to 160°C for the first monomer, 110 to 160°C for the second monomer, and 110 to 160°C for the third monomer. Note that the "temperature at which the evaporation rate is sufficiently high in an environment of 1.0 to 10.0 Pa (evaporation temperature)" can be determined by identifying on a graph the temperature at which the weight loss rate peaks when thermal analysis (TG-DTA) is performed on the monomers in an environment of 1.0 to 10.0 Pa. When the content of the third monomer is relatively low, it may be advantageous to use a third monomer having a relatively low evaporation temperature, which can promote evaporation and vapor deposition of the third monomer.

[0137] The step of curing the monomer layer to form a resin thin film layer can be performed according to a known method, for example, the method described in WO 2015 / 118693. Specifically, for example, the step 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.

[0138] Known methods can be used for forming the metal thin film layer and for alternately laminating the resin thin film layer and the metal thin film layer. For example, the method described in WO 2015 / 118693 can be used.

[0139] (Vapor Deposition) In one embodiment of the manufacturing method according to the present disclosure, the resin thin film layer and the internal electrode metal layer are formed by a vapor deposition method.

[0140] In one embodiment of the manufacturing method according to the present disclosure, when forming the monomer layer, a mixture of the first monomer and the second monomer and a third monomer which is a trifunctional or higher polyfunctional monomer are vapor-deposited from separate evaporation sources.

[0141] (Additional Curing Treatment by Heating) In one embodiment of the manufacturing method according to the present disclosure, the laminate structure formed as described above is heated to promote curing of the uncured components in the resin thin film layer.

[0142] In particular, when a monomer having a polymerizable functional group (e.g., an allyl group) with lower polarity than acrylic and methacrylic groups is used as the trifunctional or higher polyfunctional monomer, a particularly good degree of curing can be achieved by further performing a heat treatment after the formation of the laminate structure. The heating temperature may be 150 to 250°C, and the heating time may be 1 to 10 hours.

[0143] As is clear from the above description, the invention related to the manufacturing method of the present application can have the various features described for the capacitor of the present invention. Some specific embodiments are listed below. These may be used alone or in combination: (a) the third monomer is a trifunctional monomer; (b) the third monomer includes a monomer having an allyl group; (c) the third monomer includes triallyl isocyanurate; (d) at least one of the first monomer and the second monomer includes a monomer having an acrylic group or a methacrylic group; (e) the first monomer includes 2-(biphenyl-2-yloxy)-ethyl acrylate, 4-phenylbenzyl acrylate, stearyl acrylate, or stearyl methacrylate, and / or the second monomer includes tricyclodecane dimethanol diacrylate or tricyclodecane dimethanol dimethacrylate; (f) the capacitor has a tan δ of less than 2.0% when measured at 105°C and 1 kHz.

[0144] (Applications) The applications of the present capacitor are not particularly limited, but the present capacitor is particularly suitable for high voltage applications (e.g., 200 V or higher).

[0145] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0146] <<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.

[0147] <Example 1> (Production of thin film polymer laminate capacitor) In a vacuum chamber, a process of forming a resin thin film layer and a process of forming a metal thin film layer were alternately repeated on a rotating drum to produce a laminate in which a total of 2,500 resin thin film layers and metal thin film layers (internal electrode metal layers) were alternately stacked on the rotating drum.

[0148] In the step of forming the resin thin film layer, the following Monomers 1 to 3 were used in a molar ratio of 45:45:10: Monomer 1 (monofunctional monomer): 2-(biphenyl-2-yloxy)-ethyl acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: A-LEN-10) Monomer 2 (bifunctional monomer): tricyclodecane dimethanol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: A-DCP) Monomer 3 (trifunctional monomer): triallyl isocyanurate (manufactured by Shinryo Corporation, product name: Tyke (registered trademark))

[0149] The mixture of the monomers was vapor-deposited in a vacuum chamber to form a monomer layer, which was then cured by irradiating it with an electron beam at an acceleration voltage of 5 kV and an irradiation current of 50 mA, thereby forming a resin thin film layer having a thickness of 0.5 μm.

[0150] 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 15 Ω / □.

[0151] 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.

[0152] (tan δ) For the capacitor according to Example 1 obtained as described above, tan δ (%) was measured using an LCR meter under the conditions of each temperature and 1 kHz shown in the graph of Fig. 2. The results are shown in Fig. 2 and Table 1 below.

[0153] (Evaluation of tan δ in the room temperature range) Of the measured tan δ, the tan δ in the room temperature range was evaluated according to the following evaluation criteria: (++) The value of tan δ measured at 20°C was less than 0.5%. (+) The value of tan δ measured at 20°C was 0.5% to 0.6%. (--) The value of tan δ measured at 20°C was more than 0.6%.

[0154] (Evaluation of tan δ in high temperature range) Of the measured tan δ, the high temperature tan δ was evaluated according to the following evaluation criteria: (+++) The value of tan δ measured at 105°C was less than 0.5%. (++) The value of tan δ measured at 105°C was 0.5% or more and less than 1.2%. (+) The value of tan δ measured at 105°C was 1.2% or more and 2.0% or less. (- -) The value of tan δ measured at 105°C was more than 2.0%.

[0155] (Capacitance Change Rate) The capacitance change rate (%) of the capacitor according to Example 1 obtained as described above was measured when the capacitor was placed under a specific environment. Specifically, the capacitance (μF) of the capacitor after standing for 20 minutes at each temperature shown in FIG. 3 was measured at 1 kHz using an LCR meter, and the measured value was compared with the initial capacitance to calculate the capacitance change rate (%). The results are shown in FIG. 3 and Table 1. The initial capacitance was approximately 1 μF.

[0156] (Evaluation of capacity change rate at high temperatures) The capacity change rate measured at high temperatures was evaluated according to the following evaluation criteria: (+++) The capacity change rate at 105°C was less than 4%. (++) The capacity change rate at 105°C was 4% or more and less than 6%. (+) The capacity change rate at 105°C was 6% or more and 8% or less. (--) The capacity change rate at 105°C was more than 8%.

[0157] (Water absorption rate) A resin film as a resin sample was placed in a constant temperature and humidity chamber at a temperature of 60°C and a relative humidity of 90%, and a moisture absorption test was carried out by leaving the film to stand for 100 hours. The weight change rate of the resin film after the moisture absorption test was measured according to the following formula, and this was defined as the water absorption rate (%). Weight change rate (%) = 100 × (weight after moisture absorption test - weight before moisture absorption test) / weight before moisture absorption test

[0158] The resin film used for measuring the water absorption rate was prepared as follows: a test monomer of the same type and composition as that used in forming the resin thin film layer of the capacitor was provided, a photoinitiator (2-benzyl-2-dimethylamino-4'morpholinobutyrophenone, manufactured by Tokyo Chemical Industry Co., Ltd.) was mixed with 100 moles of the test monomer in a ratio of 0.2±0.01 moles to form a mixture, the mixture was poured into a round dish, and the mixture poured into the round dish was irradiated with UV light in a nitrogen atmosphere under conditions of 120 W and a distance of 250 mm until polymerization stopped proceeding, thereby preparing a disk-shaped resin film having dimensions of 30 mm in diameter and 1 mm in depth.

[0159] Example 2 A capacitor was manufactured and evaluated in the same manner as in Example 1 above. However, in the process of forming the resin thin film layer, the following Monomers 1 to 3 were used in a molar ratio of 45:45:10: Monomer 1 (monofunctional monomer): 2-(biphenyl-2-yloxy)-ethyl acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: A-LEN-10) Monomer 2 (bifunctional monomer): tricyclodecane dimethanol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: A-DCP) Monomer 3 (trifunctional monomer): trimethylolpropane triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: A-TMPT) The results are shown in Figures 2 and 3 and Table 1. The initial capacitance was approximately 1 μF.

[0160] Comparative Example 1 A capacitor according to Comparative Example 1 was manufactured and evaluated in the same manner as in Example 1, except that only a monofunctional monomer, 2-(biphenyl-2-yloxy)-ethyl acrylate, and a bifunctional monomer, tricyclodecane dimethanol diacrylate, were used in a molar ratio of 50:50. The results are shown in the graphs of FIGS. 2 and 3 and in Table 1.

[0161] Comparative Example 2 A capacitor according to Comparative Example 2 was manufactured and evaluated in the same manner as in Example 1, except that only tricyclodecane dimethanol diacrylate, a bifunctional monomer, was used as the monomer. The results are shown in the graphs of FIGS. 2 and 3 and in Table 1.

[0162]

[0163] As can be seen from Table 1, Comparative Example 1, which used monofunctional and bifunctional monomers, exhibited superior water absorption and properties (tan δ) at room temperature compared to Comparative Example 2, which used only bifunctional monomers.

[0164] On the other hand, the capacitor according to Comparative Example 1, which used monofunctional and bifunctional monomers, had relatively poor high-temperature characteristics (tan δ and capacitance change rate) compared to the capacitor according to Comparative Example 2, which used only bifunctional monomers. Without intending to be limited by theory, this is thought to be because Comparative Example 1 contained a monofunctional monomer, which resulted in a relatively reduced density of the network structure (crosslinks) in the polymer.

[0165] In contrast, as can be seen from Table 1, Example 1, which used a trifunctional monomer in addition to the monofunctional and bifunctional monomers, exhibited superior water absorption and characteristics (tan δ) in the room temperature range compared to Comparative Example 2, which used only a bifunctional monomer, and also exhibited superior high-temperature characteristics compared to Comparative Example 1, which used a monofunctional and bifunctional monomer.

[0166] This tendency was also observed in Example 2, in which trimethylolpropane triacrylate having an acrylic group was used instead of triallyl isocyanurate as the trifunctional monomer.

[0167] The properties of Example 1 were relatively superior in terms of water absorption and electrical properties compared to Example 2. Without intending to be limited by theory, it is believed that in Example 1, the use of a monomer having an allyl group with relatively low polarity as a trifunctional monomer particularly effectively suppressed the increase in water absorption and tan δ caused by the use of a polyfunctional monomer.

[0168] <<Examples 3 to 7>> The water absorption of mixtures of monomers having various compositions was measured in the same manner as above. The results are shown in Table 2 below (the proportions of monomers are shown as molar ratios). The monomers used were as follows: Monofunctional monomer: 2-(biphenyl-2-yloxy)-ethyl acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: A-LEN-10) Bifunctional monomer: tricyclodecane dimethanol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: A-DCP) Trifunctional monomer having an allyl group: triallyl isocyanurate (manufactured by Shinryo Corporation, product name: TAIC (registered trademark)) Trifunctional monomer having an acrylic group: trimethylolpropane triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: A-TMPT)

[0169]

[0170] The resin films of Examples 3 to 7 all have a polymer structure formed by polymerizing a monofunctional monomer, a difunctional monomer, and a trifunctional monomer, and as can be seen in Table 2, all of them exhibited good water absorption (relatively low water absorption).

[0171] The results in Table 2 show that trifunctional monomers having allyl groups can be particularly effective, particularly in terms of water absorption: when the trifunctional monomer content was relatively low, there was no difference in water absorption between allyl and acrylic groups (Examples 3 and 5), but when the trifunctional monomer content was relatively high, the examples using allyl groups had relatively lower water absorption than the acrylic groups (Examples 4, 6, and 7).

Claims

1. A thin-film polymer laminate capacitor having a structure in which thin resin layers and internal electrode metal layers are alternately laminated, wherein the thin resin layers have a polymer structure obtained by polymerizing a first monomer which is a monofunctional monomer, a second monomer which is a difunctional monomer, and a third monomer which is a trifunctional or higher polyfunctional monomer.

2. The capacitor described in claim 1, wherein in the polymer structure of the resin thin film layer, a ratio M3 / (M1+M2+M3) of the molar amount M3 of the monomer unit derived from the third monomer to the sum of M1 of the monomer unit derived from the first monomer, M2 of the monomer unit derived from the second monomer, and M3 of the monomer unit derived from the third monomer is 0.01 to 0.

3.

3. The capacitor according to claim 1 or 2, wherein the third monomer is a trifunctional monomer.

4. The capacitor according to claim 1 or 2, wherein the third monomer comprises a monomer having an allyl group.

5. The capacitor of claim 1 or 2, wherein the third monomer comprises triallyl isocyanurate.

6. The capacitor according to claim 1 or 2, wherein at least one of the first monomer and the second monomer includes a monomer having an acrylic group or a methacrylic group.

7. The capacitor of claim 1 or 2, wherein the first monomer comprises 2-(biphenyl-2-yloxy)-ethyl acrylate, 4-phenylbenzyl acrylate, stearyl acrylate, or stearyl methacrylate, and / or the second monomer comprises tricyclodecane dimethanol diacrylate or tricyclodecane dimethanol dimethacrylate.

8. The capacitor of claim 1 or 2, wherein the capacitor has a tan δ of less than 2.0% when measured at 105° C. and 1 kHz.

9. A method for manufacturing a thin film polymer laminate capacitor having a laminate 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 monofunctional monomer, a second monomer which is a difunctional monomer, and a third monomer which is a trifunctional or higher polyfunctional monomer; forming an internal electrode metal layer by evaporating metal on the resin thin film layer; and forming the laminate structure by alternately repeating the formation of the resin thin film layer and the formation of the internal electrode metal layer.

10. The method for producing a capacitor according to claim 9, wherein a ratio m3 / (m1+m2+m3) of the molar amount m3 of the third monomer to the sum of the molar amount m1 of the first monomer, the molar amount m2 of the second monomer, and the molar amount m3 of the third monomer is 0.01 to 0.

3.

11. The method according to claim 9 or 10, further comprising heating the laminated structure to promote curing of uncured components in the resin thin film layer.

12. The method according to claim 9 or 10, wherein the resin thin film layer and the internal electrode metal layer are formed by vapor deposition.

13. The method according to claim 9 or 10, wherein, when forming the monomer layer, the mixture of the first monomer and the second monomer, and the third monomer are evaporated from separate evaporation sources.

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