Insulating film, copper-clad laminate, and millimeter wave antenna

Abstract

Provided is an insulating film which is formed from a material containing a 3-methyl-1-butene polymer and which has a dielectric loss tangent of less than 0.00070 at 10 GHz to 300 GHz.

Description

Technical Field

[0001] The present invention relates to an insulating film, a copper-clad laminate including the insulating film, and a millimeter-wave antenna including the copper-clad laminate. Background Art

[0002] With the high performance and high functionality of electrical and electronic devices, radars such as LRR (Long Range Radar) and SRR (Short Range Radar) are also mounted in vehicles such as automobiles and buses. With the realization of a society of high-capacity high-speed communication, this radar is required to detect radio waves in a high-frequency range greater than 10 GHz, for example, radio waves in the millimeter-wave (frequency 30 GHz to 300 GHz) band.

[0003] A radar generally consists of an antenna and a housing covering the antenna. Conventionally, for the materials used in the above antenna and housing, excellent dielectric properties capable of being used in a high-frequency range have been required, and polyphenylene ether, maleimide triazine resin, etc. have been used. In addition, as resins having excellent dielectric properties, polyolefin resins such as polypropylene and fluororesins such as polytetrafluoroethylene are also known.

[0004] For example, in Patent Document 1, a high-frequency dielectric antenna including a resin composition containing a crystalline cyclic olefin ring-opening polymer hydride having a repeating unit derived from a polycyclic norbornene-based monomer and a glass filler is disclosed. In addition, in Patent Document 2, a double-sided metal-clad dielectric substrate for a planar antenna is disclosed, which is characterized in that the entire back surface of the dielectric substrate is used as a ground conductor, and a metal foil for forming a circularly polarized wave radiation microstrip element is provided on the surface, and the dielectric layer contains a homopolymer of 3-methyl-1-butene or a copolymer of 3-methyl-1-butene and an olefin and / or polyene having 2 to 12 carbon atoms.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2013-256596

[0008] Patent Document 2: Japanese Unexamined Patent Application Publication No. 63-086320 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] The antenna substrate constituting the antenna may use an insulating member such as an insulating film. For example, an antenna including an insulating film containing polyphenylene ether, maleimide triazine resin, etc. has no problem in use in the frequency band of several GHz, however, there are problems such as large transmission loss when used in the frequency band of dozens of GHz.

[0011] According to the description, the dielectric for a planar antenna disclosed in Patent Document 2 has a dielectric constant of 2.2 and a dielectric loss tangent of 10 at a frequency of 12 GHz. -3 However, even for the above-mentioned dielectric for a planar antenna, there may be transmission loss when used in the millimeter-wave frequency band which is a high-frequency range, and there is room for improvement. Therefore, new materials with more excellent dielectric properties are desired.

[0012] In addition, polyolefin resins such as polypropylene have poor heat resistance, so they cannot withstand manufacturing processes such as reflow soldering. It is described in Patent Document 1 that by using glass fillers, etc., it is possible to withstand high-temperature states such as the reflow process, however, further improvement in reflow heat resistance is required. In addition, fluororesins such as polytetrafluoroethylene have poor formability, low productivity and high price.

[0013] In view of such a situation, the subject of the present invention is to provide an insulating film capable of manufacturing a millimeter-wave antenna having a low relative dielectric constant and a low dielectric loss tangent, excellent formability and excellent reflow heat resistance, a copper-clad laminate including the insulating film, and a millimeter-wave antenna including the copper-clad laminate.

[0014] Means for Solving the Subject

[0015] In order to solve the above-mentioned subject, in-depth research was conducted, and as a result, the present inventors came up with the following present invention and found that the subject can be solved.

[0016] That is, the present invention is as follows.

[0017] [1]An insulating film containing a material including a 3-methyl-1-butene-based polymer, and having a dielectric loss tangent of less than 0.00070 at 10 GHz to 300 GHz.

[0018] [2]The insulating film according to the above [1], wherein the 3-methyl-1-butene-based polymer is at least one selected from a 3-methyl-1-butene homopolymer and a copolymer of 3-methyl-1-butene and ethylene or an α-olefin, and the α-olefin has 3 to 20 carbon atoms.

[0019] [3]The insulating film according to the above [2], wherein the content ratio of the structural unit derived from the ethylene or the α-olefin in the copolymer is greater than 0 mol% and 20 mol% or less.

[0020] [4] The insulating film according to [2] or [3] above, wherein the content ratio of the structural unit derived from the above ethylene or the above α-olefin in the above copolymer is greater than 0 mol% and 10 mol% or less.

[0021] [5] The insulating film according to any one of [1] to [4] above, wherein the melting point of the above 3-methyl-1-butene-based polymer is 260 to 310 °C.

[0022] [6] The insulating film according to any one of [1] to [5] above, wherein the above material is a resin composition containing the above 3-methyl-1-butene-based polymer and an alkyl radical scavenger.

[0023] [7] The insulating film according to [6] above, wherein the above alkyl radical scavenger contains at least one selected from acrylic phenolic compounds and benzofuranone compounds.

[0024] [8] A copper-clad laminate comprising the insulating film according to any one of [1] to [7] above.

[0025] [9] A millimeter-wave antenna comprising the copper-clad laminate according to [8] above.

[0026]

[10] A millimeter-wave antenna comprising the insulating film according to any one of [1] to [7] above.

[0027] Advantages of the Invention

[0028] According to the present invention, it is possible to provide an insulating film capable of manufacturing a millimeter-wave antenna having a low relative dielectric constant and a low dielectric loss tangent, excellent formability and reflow heat resistance, and excellent reflow heat resistance, a copper-clad laminate including the insulating film, and a millimeter-wave antenna including the copper-clad laminate. Detailed Embodiments

[0029] Hereinafter, an example of an embodiment of the present invention will be described. However, the embodiments shown below are illustrative examples for embodying the technical idea of the present invention, and the present invention is not limited to the following description.

[0030] In this specification, preferred modes of the embodiment are given, and modes obtained by combining two or more of the respective preferred modes are also preferred modes. Regarding matters given in the numerical range, in the case where there are several numerical ranges, their lower limit values and upper limit values can be selectively combined to form preferred modes.

[0031] In this specification, when there is a description of a numerical range of "XX to YY", it means "XX or more and YY or less".

[0032] <Insulating film>

[0033] The insulating film of this embodiment is characterized by containing a material including a 3-methyl-1-butene-based polymer, and the dielectric loss tangent at 10 GHz to 300 GHz is less than 0.00070. That is, the insulating film of this embodiment contains a 3-methyl-1-butene-based polymer.

[0034] By making the material for forming the insulating film include a 3-methyl-1-butene-based polymer, while having a low relative dielectric constant and a low dielectric loss tangent, the formability and reflow heat resistance are excellent.

[0035] In addition, since the material for forming the insulating film of this embodiment has excellent heat resistance, it can be made into any shape.

[0036] In addition, since the 3-methyl-1-butene-based polymer has a high melting point and low water absorption, the insulating film of this embodiment is not likely to warp, melt, or foam during reflow soldering. In addition, even when stored in a humid and hot environment, it will not foam during reflow soldering, and easy storage management can be expected.

[0037] Furthermore, since the 3-methyl-1-butene-based polymer has a low specific gravity, the insulating film of this embodiment can also contribute to weight reduction.

[0038] The material used in the insulating film of this embodiment can be a material composed of a 3-methyl-1-butene-based polymer, or a resin composition containing components other than the 3-methyl-1-butene-based polymer.

[0039] [Material]

[0040] The material used in the insulating film of this embodiment contains a 3-methyl-1-butene-based polymer. That is, the insulating film of this embodiment contains a 3-methyl-1-butene-based polymer.

[0041] 〈3-methyl-1-butene-based polymer〉

[0042] 3-Methyl-1-butene-based polymers are polymers containing at least structural units derived from 3-methyl-1-butene. The 3-methyl-1-butene-based polymers can be 3-methyl-1-butene homopolymers or copolymers of 3-methyl-1-butene and unsaturated hydrocarbons. The unsaturated hydrocarbons can be one kind or multiple kinds. Examples of the above-mentioned unsaturated hydrocarbons include ethylene or α-olefins. It should be noted that in this embodiment, the α-olefins used in the 3-methyl-1-butene-based polymers refer to α-olefins other than 3-methyl-1-butene. That is, the α-olefins refer to α-olefins other than 3-methyl-1-butene, and are also expressed as α-olefins (excluding 3-methyl-1-butene). From the viewpoint of good copolymerizability, the above-mentioned unsaturated hydrocarbons are preferably ethylene or α-olefins having 3 to 20 carbon atoms. The α-olefins having 3 to 20 carbon atoms can be one kind or multiple kinds.

[0043] From the viewpoint of suitably exhibiting mechanical properties (moderate strength, flexibility, and impact resistance), the 3-methyl-1-butene-based polymers are preferably at least one selected from 3-methyl-1-butene homopolymers and copolymers of 3-methyl-1-butene and ethylene or α-olefins having 3 to 20 carbon atoms, and more preferably copolymers of 3-methyl-1-butene and ethylene or α-olefins having 3 to 20 carbon atoms. The copolymer of 3-methyl-1-butene and ethylene or α-olefins having 3 to 20 carbon atoms means a copolymer of 3-methyl-1-butene and ethylene or a copolymer of 3-methyl-1-butene and α-olefins having 3 to 20 carbon atoms. Hereinafter, the copolymer of 3-methyl-1-butene and ethylene or α-olefins will also be abbreviated as "copolymer".

[0044] The above-mentioned copolymer can be a random copolymer, a block copolymer, or an alternating copolymer. The method for producing the above-mentioned copolymer is not limited as long as the effects of the present invention are not impaired, and a known copolymerization method can be adopted.

[0045] When the 3-methyl-1-butene-based polymer is the above-mentioned copolymer, the content ratio of the structural units derived from ethylene or α-olefins in 100 mol% of the copolymer is preferably greater than 0 mol% and 20 mol% or less.

[0046] From the viewpoints of flexibility and impact resistance, the content ratio of the structural units derived from ethylene or α-olefins in 100 mol% of the copolymer is more preferably 0.1 mol% or more, and further preferably 0.5 mol% or more.

[0047] In addition, from the viewpoint of reflux heat resistance, the content ratio of the structural units derived from ethylene or α-olefins in 100 mol% of the copolymer is more preferably 15 mol% or less, and further preferably 10 mol% or less.

[0048] From these viewpoints, the content ratio of the structural units derived from ethylene or an α-olefin in 100 mol% of the copolymer is more preferably 0.1 to 15 mol%, and further preferably 0.5 to 10 mol%. In one mode, the content ratio of the structural units derived from ethylene or an α-olefin in 100 mol% of the copolymer is more preferably greater than 0 mol% and 10 mol% or less.

[0049] It should be noted that the content ratio of the structural units derived from ethylene or an α-olefin in the above copolymer can be determined using a Fourier transform infrared spectrophotometer (FT-IR). Specifically, it can be measured using the method described in the examples.

[0050] When the 3-methyl-1-butene-based polymer is the above copolymer, the content ratio of the structural units derived from 3-methyl-1-butene in 100 mol% of the copolymer is preferably 80 mol% or more and less than 100 mol%.

[0051] From the viewpoint of reflux heat resistance, the content ratio of the structural units derived from 3-methyl-1-butene in 100 mol% of the copolymer is preferably greater than 50 mol%, more preferably 70 mol% or more, further preferably 85 mol% or more, further preferably 90 mol% or more, further preferably 92 mol% or more, and even more preferably 93 mol% or more.

[0052] In addition, from the viewpoints of flexibility and impact resistance, the content ratio of the structural units derived from 3-methyl-1-butene in 100 mol% of the copolymer is more preferably 99.9 mol% or less, and further preferably 99.5 mol% or less.

[0053] From these viewpoints, the content ratio of the structural units derived from 3-methyl-1-butene in 100 mol% of the copolymer is preferably 85 to 99.9 mol%, further preferably 90 to 99.5 mol%, even more preferably 92 to 99.5 mol% or less, and even more preferably 93 to 99.5 mol%.

[0054] From the viewpoint of suitably exhibiting the physical properties of the 3-methyl-1-butene-based polymer, the ethylene or α-olefin is preferably an α-olefin having 3 to 20 carbon atoms, more preferably an α-olefin having 4 to 16 carbon atoms, further preferably an α-olefin having 4 to 12 carbon atoms, even more preferably an α-olefin having 4 to 10 carbon atoms, and even more preferably an α-olefin having 6 to 10 carbon atoms. In addition, the α-olefin can be linear, branched, cyclic, or can include a cyclic part.

[0055] Examples of α-olefins having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, vinylcyclohexene, vinylnorbornane, etc. The α-olefins having 3 to 20 carbon atoms are preferably linear α-olefins, more preferably at least one selected from 1-butene, 1-octene, 1-nonene, 1-decene, and still more preferably at least one selected from 1-octene, 1-nonene, 1-decene, and even more preferably 1-decene.

[0056] The α-olefins having 2 to 20 carbon atoms, i.e., ethylene or α-olefins having 3 to 20 carbon atoms, can be used alone or in combination of two or more.

[0057] The melting point of the 3-methyl-1-butene-based polymer is preferably 260 to 310 °C. If the melting point of the 3-methyl-1-butene-based polymer is within the above range, the material used in the insulating film can be easily formed by extrusion molding or the like, and the reflow heat resistance of the millimeter-wave antenna becomes better.

[0058] It should be noted that the melting point of the 3-methyl-1-butene-based polymer means the temperature obtained as follows: using a differential scanning calorimeter, the test piece (3-methyl-1-butene-based polymer) is heated from 30 °C to 320 °C at a rate of 10 °C / min in a nitrogen flow (100 mL / min), held at 320 °C for 5 minutes, then cooled to -70 °C at a rate of 10 °C / min, then held at -70 °C for 5 minutes, and then heated to 320 °C at a rate of 10 °C / min. It means the peak temperature at this time. Specifically, it can be measured by the method described in the examples.

[0059] From the viewpoint of the balance between production efficiency and reflow heat resistance, the melting point of the 3-methyl-1-butene-based polymer is more preferably 270 to 305 °C, further preferably 280 to 305 °C, and still further preferably 280 to 300 °C.

[0060] The melt viscosity of the 3-methyl-1-butene-based polymer of the present embodiment is preferably 10 to 1000 Pa·s. If the melt viscosity of the 3-methyl-1-butene-based polymer is 10 Pa·s or more, the mechanical strength is further improved. If it is 1000 Pa·s or less, good fluidity is easily obtained during forming.

[0061] From the viewpoint of the balance between mechanical strength and fluidity during forming, the melt viscosity of the 3-methyl-1-butene polymer is more preferably 30 to 500 Pa·s, further preferably 50 to 300 Pa·s, still further preferably 50 to 200 Pa·s, and even more preferably 70 to 150 Pa·s.

[0062] It should be noted that the melt viscosity of the 3-methyl-1-butene polymer in this embodiment means the value measured using a capillary rheometer under the conditions of a barrel temperature of 320 °C and a shear rate of 1220 sec -1 (capillary: inner diameter 1.0 mm × length 10 mm, extrusion speed 10 mm / min), and specifically, it can be measured by the method described in the examples.

[0063] From the viewpoints of formability and reflow heat resistance, the content ratio of the 3-methyl-1-butene polymer in 100% by mass of the material used in the insulating film is preferably 80.0 to 99.9% by mass, more preferably 85.0 to 99.9% by mass, and still further preferably 90.0 to 99.9% by mass. Since 3-methyl-1-butene has a high melting point, if the proportion of 3-methyl-1-butene is increased, the reflow heat resistance of the millimeter-wave antenna tends to increase. The content ratio of the 3-methyl-1-butene polymer in the insulating film is the same as above.

[0064] Since the 3-methyl-1-butene polymer has a low specific gravity, it can contribute to the weight reduction of the insulating film. In addition, the 3-methyl-1-butene polymer does not generate harmful gases during incineration. Furthermore, the decomposition products in an inert atmosphere are low-molecular-weight hydrocarbons, which are suitable for chemical recycling.

[0065] [Resin composition]

[0066] The material contained in the insulating film of this embodiment includes a 3-methyl-1-butene polymer. In addition, the material contained in the insulating film of this embodiment may also be a resin composition. Therefore, the "material" and the "resin composition" contained in the insulating film of this embodiment are synonymous.

[0067] <Alkyl radical scavenger>

[0068] From the viewpoint of exhibiting more excellent dielectric properties and mechanical properties, the material used in the insulating film may be a resin composition containing the above-mentioned 3-methyl-1-butene polymer and an alkyl radical scavenger. In this case, the insulating film of this embodiment also contains an alkyl radical scavenger or its reaction product or its decomposition product.

[0069] In this embodiment, the so-called "alkyl radical scavenger" means a compound having a function of reacting with an alkyl radical derived from a 3-methyl-1-butene-based polymer and then stabilizing the radical, and functions to suppress a chain main-chain scission reaction starting from the alkyl radical.

[0070] From the viewpoint of further exerting mechanical properties, the alkyl radical scavenger preferably contains at least one selected from acrylic phenol compounds and benzofuranone compounds.

[0071] The alkyl radical scavenger may be used alone or in combination of two or more.

[0072] (Acrylic phenol compound)

[0073] The acrylic phenol compound used in this embodiment can be represented, for example, by the following general formula (I).

[0074] [Chemical formula 1]

[0075]

[0076] In the general formula (I), R 1 represents a hydrogen atom or a methyl group, R 2 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R 3 , R 4 , R 5 and R 6 each independently represent an alkyl group having 1 to 9 carbon atoms.

[0077] Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, a n-propyl group, and an isopropyl group.

[0078] The alkyl group having 1 to 9 carbon atoms may be linear or branched.

[0079] Examples of the alkyl group having 1 to 9 carbon atoms include a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a 1,1-dimethylpropyl group, a 1,2-dimethylpropyl group, a 2,2-dimethylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a n-pentyl group, a n-hexyl group, a n-heptyl group, a n-octyl group, and a n-nonyl group.

[0080] R 1 is preferably a hydrogen atom.

[0081] R 2 is preferably a hydrogen atom or a methyl group, more preferably a methyl group.

[0082] R 3 , R 4 , R 5 and R 6Each is independently preferably an alkyl group having 3 to 8 carbon atoms, more preferably an alkyl group having 5 carbon atoms, and still more preferably 1,1-dimethylpropyl.

[0083] Examples of the acrylic phenolic compound represented by the general formula (I) include 2,4-ditertiary pentyl-6-[1-(3,5-ditertiary pentyl-2-hydroxyphenyl)ethyl]phenyl acrylate, 2,4-ditertiary butyl-6-[1-(3,5-ditertiary butyl-2-hydroxyphenyl)ethyl]phenyl acrylate, and 2-tertiary butyl-6-[(3-tertiary butyl-2-hydroxy-5-methylphenyl)methyl]-4-methylphenyl acrylate.

[0084] Commercially available products can also be used as the alkyl radical scavenger. Examples of the acrylic phenolic compound represented by the general formula (I) include products with the trade names "SUMILIZER (registered trademark) GS" and "SUMILIZER (registered trademark) GM" manufactured by Sumitomo Chemical Company.

[0085] (Benzofuranone compound)

[0086] The benzofuranone compound used in this embodiment can be represented, for example, by the following general formula (II).

[0087] [Chemical formula 2]

[0088]

[0089] In the general formula (II), R 7 and R 8 each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R 9 and R 10 each independently represents an alkyl group having 1 to 9 carbon atoms.

[0090] Examples of the alkyl group having 1 to 4 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl.

[0091] The alkyl group having 1 to 9 carbon atoms can be linear or branched. Examples of the alkyl group having 1 to 9 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, and n-nonyl.

[0092] R 7 and R 8 each independently is preferably an alkyl group having 1 to 3 carbon atoms, and more preferably methyl.

[0093] R 9 and R10 Each is independently preferably an alkyl group having 1 to 4 carbon atoms, more preferably a tert-butyl group.

[0094] Examples of the benzofuranone compound represented by the general formula (II) include 5,7-di-tert-butyl-3-(3,4-dimethylphenyl)-3H-benzofuran-2-one, 5,7-di(tert-butyl)-3-(3,4-dipropylphenyl)-3H-benzofuran-2-one, and the like.

[0095] Commercially available products can also be used as the alkyl radical scavenger. Examples of the benzofuranone compound represented by the general formula (II) include the product name "Irganox (registered trademark) HP-136" manufactured by BASF JAPAN Co., Ltd., the product name "Revonox (registered trademark) 501" manufactured by Chitec Co., Ltd., and the like.

[0096] (Content of alkyl radical scavenger)

[0097] The content of the alkyl radical scavenger in the resin composition relative to 100 parts by mass of the 3-methyl-1-butene-based polymer is preferably 0.01 to 1.00 part by mass. The content ratio of the alkyl radical scavenger in the insulating film is the same as above.

[0098] When the content of the alkyl radical scavenger is 0.01 part by mass or more, the physical properties of the resin composition can be more stably maintained during the melt-kneading of the resin composition. In addition, it is also possible to suppress the generation of decomposition gas during melt molding, resulting in poor molding.

[0099] In addition, when the content of the alkyl radical scavenger is 1.00 part by mass or less, it is easy to obtain an insulating film having more excellent mechanical properties. In addition, it is possible to suppress the exudation of the alkyl radical scavenger or the deterioration of hygroscopicity, etc., in which the physical properties required for the resin composition are impaired.

[0100] From the viewpoint of more stably maintaining the physical properties of the resin composition during melt-kneading, the content of the alkyl radical scavenger in the resin composition relative to 100 parts by mass of the 3-methyl-1-butene-based polymer is more preferably 0.02 part by mass or more, and further preferably 0.05 part by mass or more.

[0101] In addition, from the viewpoints of the balance between the maintenance of the stability of the physical properties of the resin composition and economy, and obtaining an insulating film having a lower relative permittivity and a lower dielectric loss tangent, the content of the alkyl radical scavenger in the resin composition relative to 100 parts by mass of the 3-methyl-1-butene-based polymer is more preferably 0.80 part by mass or less, and further preferably 0.70 part by mass or less.

[0102] From these viewpoints, the content of the alkyl radical scavenger in the resin composition is more preferably 0.02 to 0.80 parts by mass, and further preferably 0.05 to 0.70 parts by mass, relative to 100 parts by mass of the 3-methyl-1-butene-based polymer.

[0103] It should be noted that in the case of containing two or more kinds of alkyl radical scavengers, the content of the above alkyl radical scavenger means the total content of the alkyl radical scavengers.

[0104] 〈Antioxidant〉

[0105] From the viewpoint of ensuring the stability of the polymer, the resin composition may contain an antioxidant.

[0106] The antioxidant preferably contains at least one selected from phenolic antioxidants and phosphorus-based antioxidants.

[0107] The antioxidant may be used alone or in combination of two or more.

[0108] (Phenolic antioxidant)

[0109] Examples of phenolic antioxidants include pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris[(4-tert-butyl-3-hydroxy-2,6-dimethylphenyl)methyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, thiodiethylene-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexanediamine, 3,3',3'',5,5',5''-hexatert-butyl-α,α',α''-(mesitylene-2,4,6-triyl)triscresol, ethylenebis(oxyethylene)bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], hexamethylene-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,6-di-tert-butyl-4-[4,6-bis(octylthio)-1,3,5-triazin-2-ylamino]phenol, 3,9-bis[2-(3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy)-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane, 4,4',4''-(1-methylpropylidene-3-yl)tris(6-tert-butyl-m-cresol), 6,6'-di-tert-butyl-4,4'-butylidenebis(m-cresol), octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate, and 3,5-bis(1,1-dimethylethyl)-4-hydroxy-C7-C9 branched alkyl benzenepropionate, etc.

[0110] Commercially available products can also be used as phenolic antioxidants. Examples include "Adekastab (registered trademark) AO series" manufactured by ADEKA Corporation, "Irganox (registered trademark) series" manufactured by BASF JAPAN Co., Ltd., etc.

[0111] (Phosphorus-based antioxidants)

[0112] Phosphorus-based antioxidants include, for example, 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, tetra(2,4-di-tert-butylphenyl)-4,4'-biphenylylphosphonite, 2,2-methylenebis(4,6-di-tert-butylphenyl) octyl phosphite, tris(2,4-di-tert-butylphenyl) phosphite, diethyl 2,4-bis(1,1-dimethylethyl)-6-methylphenyl phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite, di-tert-butyl-m-tolyl phosphite, diethyl [(3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl)methyl]phosphonate, tris(2,4-di-tert-butylphenyl) phosphite, tetra(2,4-di-tert-butylphenyl)-4,4'-biphenylyl diphosphite, 3,9-bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, tris(2,4-di-tert-butylphenyl) phosphite, tris(nonylphenyl) phosphite, tetra-C 12 -C 15 -alkyl(propane-2,2-diylbis(4,1-phenylene)) bis(phosphite), 2-ethylhexyl diphenyl phosphite, isodecyl diphenyl phosphite, trisisodecyl phosphite, triphenyl phosphite, and 3,9-bis[2,4-bis(1-methyl-1-phenylethyl)phenoxy]-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, etc.

[0113] Commercially available products can also be used as phosphorus-based antioxidants, such as "Adekastab (registered trademark) PEP series" and "Adekastab (registered trademark) HP series" manufactured by ADEKA Corporation, "Irgafos (registered trademark) series" manufactured by BASF JAPAN, and the product named "HOSTANOX (registered trademark) P-EPQ" manufactured by CLARIANT, etc.

[0114] (Sulfur-based antioxidants)

[0115] Sulfur-based antioxidants include, for example, dilauryl 3,3'-thiodipropionate, dimyristyl 3,3'-thiodipropionate, distearyl 3,3'-thiodipropionate, lauryl stearyl 3,3'-thiodipropionate, pentaerythritol - tetra(β-lauryl-thiopropionate), 3,9-bis(2-dodecylethylthio)-2,4,8,10-tetraoxaspiro[5,5]undecane, etc.

[0116] (Other antioxidants)

[0117] In addition, as long as the effects of the present invention are not impaired, the resin composition may also contain antioxidants other than phenolic antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants. Examples of antioxidants other than phenolic antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants include amine-based antioxidants and the like.

[0118] (Content of antioxidant)

[0119] Regarding the content of the antioxidant in the resin composition relative to 100 parts by mass of the 3-methyl-1-butene-based polymer, from the viewpoint of ensuring the stability of the 3-methyl-1-butene-based polymer, it is preferably 0.01 part by mass or more, more preferably 0.10 part by mass or more, and from the viewpoints of relative dielectric constant and dielectric loss tangent, it is preferably 1.00 part by mass or less, more preferably 0.80 part by mass or less. That is, it is preferably 0.01 to 1.00 parts by mass, more preferably 0.10 to 0.80 parts by mass. The content ratio of the antioxidant in the insulating film is also the same as above.

[0120] It should be noted that when the resin composition contains two or more antioxidants, the content of the above-mentioned antioxidant means the total content of the antioxidants.

[0121] 〈Other additives〉

[0122] The resin composition may also contain an alkyl radical scavenger and other additives other than antioxidants.

[0123] Examples of other additives include acid inhibitors, fillers, light stabilizers, antistatic agents, flame retardants, pigments, polymerization inhibitors, heavy metal passivators, ultraviolet absorbers, nucleating agents, clarifying agents, lubricants, fluorescent brighteners, rust inhibitors, slip agents, etc.

[0124] Other additives may be used alone or in combination of two or more.

[0125] (Acid inhibitor)

[0126] From the viewpoint of suppressing deterioration caused by acid components generated from residual metal components and the like during melt-kneading, the resin composition preferably contains an acid inhibitor.

[0127] Examples of acid inhibitors include barium laurate, calcium stearate, zinc stearate, magnesium stearate, aluminum stearate, zinc oleate, magnesium 12-hydroxystearate, etc.

[0128] Acid inhibitors may be used alone or in combination of two or more.

[0129] The content of the acid inhibitor in the resin composition relative to 100 parts by mass of the 3-methyl-1-butene-based polymer can be appropriately determined, for example, it can be 0.01 to 200 parts by mass. Or it can also be 0.01 to 0.5 parts by mass, and it can also be 0.01 to 0.3 parts by mass. The content ratio of the acid inhibitor in the insulating film is the same as above.

[0130] (Antistatic agent)

[0131] Examples of the antistatic agent include sodium alkyl sulfonate salts, alkyl phosphonium sulfonate salts, fatty acid ester hydroxyamine compounds which are glycerol esters of stearic acid, etc.

[0132] The content of the antistatic agent in the resin composition relative to 100 parts by mass of the 3-methyl-1-butene-based polymer can be appropriately determined, for example, it can be 5 parts by mass or less. The content ratio of the antistatic agent in the insulating film is the same as above.

[0133] (Filler)

[0134] From the viewpoint of further improving the mechanical properties of the insulating film, the resin composition may contain a filler.

[0135] Examples of the filler include fibrous compounds such as glass fiber, alumina fiber, resin fiber, carbon fiber, cellulose fiber, etc.; plate-like compounds such as mica, talc, montmorillonite, plate-like aluminum, etc.; spherical compounds such as glass beads, white sand hollow spheres, acrylic resin hollow spheres, etc.; needle-like compounds such as needle-like metal titanates, wollastonite, needle-like silica, tin oxide, etc.; powdery compounds such as powdery metal titanates, micronized wood chips, titanium oxide, calcium carbonate, silica, alumina, etc. These fillers can be surface-treated with, for example, a silane coupling agent. In addition, a compatibilizer can be used to improve the dispersibility of the filler.

[0136] Among them, from the viewpoint of further improving the mechanical properties of the insulating film, glass fiber is preferred.

[0137] The filler can be used alone or in combination of two or more.

[0138] The content of the filler in the resin composition relative to 100 parts by mass of the 3-methyl-1-butene-based polymer can be appropriately determined, for example, it can be 0.01 to 300 parts by mass, or it can be 0.1 to 100 parts by mass. The content ratio of the filler in the insulating film is the same as above.

[0139] (Ultraviolet absorber)

[0140] As the ultraviolet absorber, for example, there can be mentioned histamine-based ultraviolet absorbers such as 2,2,6,6-tetramethyl-4-piperidyl benzoate, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)-2-(3,5-di-tert-butyl-4-hydroxybenzyl)-2-n-butylmalonate, 4-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy)-1-(2-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy)ethyl)-2,2,6,6-tetramethylpiperidine; benzotriazole-based ultraviolet absorbers such as 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-(3-tert-butyl-2-hydroxy-5-methylphenyl)-5-chlorobenzotriazole, 2-(3,5-di-tert-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3,5-di-tert-amyl-2-hydroxyphenyl)benzotriazole; benzoate-based ultraviolet absorbers such as 2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate, cetyl 3,5-di-tert-butyl-4-hydroxybenzoate; etc.

[0141] The content of the ultraviolet absorber in the resin composition relative to 100 parts by mass of the 3-methyl-1-butene-based polymer can be appropriately determined, for example, it can be 0.001 to 5 parts by mass, or it can be 0.01 to 1 part by mass. The content ratio of the ultraviolet absorber in the insulating film is the same as above.

[0142] (Lubricant)

[0143] As the lubricant, inorganic fine particles are usually used. Here, as the inorganic fine particles, there can be mentioned particles of oxides, hydroxides, sulfides, nitrides, halides, carbonates, sulfates, acetates, phosphates, phosphites, organic carboxylates, silicates, titanates, borates and their hydrates, composite compounds centered on them, natural minerals, etc. of elements of Group 1, Group 2, Group 4, Group 6, Group 7, Groups 8 to 10, Group 11, Group 12, Group 13, Group 14 of the periodic table.

[0144] As the inorganic fine particles, examples thereof include Group 1 element compounds such as lithium fluoride and borax (sodium borate hydrate); Group 2 element compounds such as magnesium carbonate, magnesium phosphate, magnesia, magnesium chloride, magnesium acetate, magnesium fluoride, magnesium titanate, magnesium silicate, magnesium silicate hydrate (talc), calcium carbonate, calcium phosphate, calcium phosphite, calcium sulfate (gypsum), calcium acetate, calcium terephthalate, calcium hydroxide, calcium silicate, calcium fluoride, calcium titanate, strontium titanate, barium titanate, zinc titanate, lanthanum titanate, bismuth titanate, lead titanate, barium carbonate, barium phosphate, barium sulfate, barium phosphite; Group 4 element compounds such as titanium dioxide (titania), titanium monoxide, titanium nitride, zirconium dioxide (zirconia), zirconium monoxide; Group 6 element compounds such as molybdenum dioxide, molybdenum trioxide, molybdenum sulfide; Group 7 element compounds such as manganese chloride, manganese acetate; Group 8 to 10 element compounds such as cobalt chloride, cobalt acetate; Group 11 element compounds such as cuprous iodide; Group 12 element compounds such as zinc oxide, zinc acetate; Group 13 element compounds such as alumina, aluminum hydroxide, aluminum fluoride, aluminosilicate (aluminum silicate oxide, kaolin, kaolinite); Group 14 element compounds such as silicon oxide (silicon dioxide, silica gel), graphite, carbon, graphite (graphite), glass; fine particles of natural minerals such as carnallite, kainite, mica (mica, phlogopite), birolite. The average particle size of the inorganic fine particles is not particularly limited, but is preferably 0.01 to 3 μm.

[0145] The content of the lubricant in the resin composition relative to 100 parts by mass of the 3-methyl-1-butene-based polymer can be appropriately determined, for example, it can be 0.001 to 5 parts by mass, or it can be 0.005 to 3 parts by mass. The content ratio of the lubricant in the insulating film is the same as described above.

[0146] <Other Resins>

[0147] The resin composition may or may not contain a resin other than the 3-methyl-1-butene-based polymer.

[0148] As resins other than 3-methyl-1-butene polymers, from the viewpoint of improving the dispersibility of additives containing polar groups, the resin composition may contain other resins such as ethylene-vinyl acetate copolymers and modified polyolefins in which the polyolefin is partially oxidized and / or modified with reactive functional groups such as maleic acid. As the polyolefin constituting the modified polyolefin modified with reactive functional groups, for example, polyethylene, polypropylene, and polyolefins having an α-olefin having 3 to 20 carbon atoms as a structural unit can be mentioned. As the α-olefin having 3 to 20 carbon atoms, the substances described in the above <3-methyl-1-butene polymers> can be mentioned. They may be homopolymers or copolymers. In addition, these polyolefins may be high density or low density, and may be polymerized using at least one of Ziegler-Natta catalysts and metallocene catalysts.

[0149] Among them, the resin other than the 3-methyl-1-butene polymer is preferably at least one selected from polyethylene or polypropylene, preferably at least one selected from modified polyethylene or modified polypropylene, more preferably at least one selected from modified polyethylene or modified polypropylene in which the polyolefin is partially oxidized and / or modified with reactive functional groups such as maleic acid, and further preferably polypropylene modified with maleic anhydride.

[0150] From the viewpoint of further exerting the effects of the present invention, the content of the ethylene-vinyl acetate copolymer and the modified polyolefin in which the polyolefin is partially oxidized and / or modified with reactive functional groups such as maleic acid in the resin composition relative to 100 parts by mass of the 3-methyl-1-butene polymer is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and further preferably 10 parts by mass or less.

[0151] As other resins other than the ethylene-vinyl acetate copolymer and the modified polyolefin in which the polyolefin is partially oxidized and / or modified with reactive functional groups such as maleic acid, for example, polyolefins such as low density polyethylene, high density polyethylene, linear low density polyethylene, ultra low density polyethylene, polypropylene, syndiotactic polypropylene, polybutene, and polyisopentene; polyesters such as polyethylene terephthalate and polybutylene terephthalate; polyamides such as nylon 6 and nylon 66; ethylene-ethyl acrylate copolymers, polystyrene, syndiotactic polystyrene, polyphenylene sulfide, polyphenylene ether, polycarbonate, thermoplastic elastomers, etc. can be mentioned.

[0152] Examples of the thermoplastic elastomer include random or block copolymers of aromatic vinyl monomers and conjugated diene monomers such as styrene-butadiene block copolymer, styrene-butadiene-styrene block copolymer, styrene-isoprene block copolymer, styrene-isoprene-styrene block copolymer, and styrene-butadiene random copolymer; polyisoprene rubber; polyolefin rubbers such as ethylene-propylene copolymer, ethylene-α-olefin copolymer, and propylene-α-olefin copolymer; diene copolymers such as ethylene-propylene-diene copolymer, α-olefin-diene copolymer, diene copolymer, isobutylene-isoprene copolymer, and isobutylene-diene copolymer; norbornene-based rubbery polymers such as copolymers of norbornene-based monomers and ethylene or α-olefin, terpolymers of norbornene-based monomers, ethylene, and α-olefin, and ring-opening polymers of norbornene-based monomers, or polymers obtained by hydrogenating them.

[0153] From the viewpoint of further improving the flexibility, bendability, and impact resistance of the insulating film, the resin composition may contain a thermoplastic elastomer. If the resin composition contains a thermoplastic elastomer, the insulating film is less likely to be strained or impacted, and the occurrence of cracks can be suppressed.

[0154] From the viewpoint of impact resistance, the thermoplastic elastomer preferably has a glass transition temperature (Tg) of 40°C or lower. Among block copolymers, there are also copolymers having two or more Tgs. As long as one of them is 40°C or lower, they can be preferably used. In addition, the number-average molecular weight of the thermoplastic elastomer is preferably 10,000 or more, more preferably 20,000 or more, further preferably 30,000 or more, and preferably 200,000 or less. If the number-average molecular weight is 10,000 or more, the mechanical properties are more excellent, and if it is 200,000 or less, the manufacturing is easier. In addition, from the aspect of compatibility with the 3-methyl-1-butene-based polymer, the thermoplastic elastomer is preferably a non-polar elastomer, that is, an elastomer composed only of carbon and hydrogen.

[0155] From the viewpoint of obtaining an insulating film having a low relative dielectric constant and a low dielectric loss tangent, the resin composition preferably reduces the amount of metal elements. Thus, from the viewpoint of easily reducing the amount of metal elements, the thermoplastic elastomer is preferably a copolymer of aromatic vinyl monomers and conjugated diene monomers, and more preferably its block copolymer.

[0156] In addition, from the viewpoint of improving weather resistance, its hydrogenated product is further preferred.

[0157] Regarding the content of other resins other than ethylene-vinyl acetate copolymers such as thermoplastic elastomers and modified polyolefins in which polyolefins are partially oxidized and / or modified with reactive functional groups such as maleic acid in the resin composition, relative to 100 parts by mass of the 3-methyl-1-butene polymer, it is preferably 1 to 100 parts by mass, more preferably 2 to 50 parts by mass, and still more preferably 3 to 30 parts by mass. The content ratio of other resins other than ethylene-vinyl acetate copolymers such as thermoplastic elastomers and modified polyolefins in which polyolefins are partially oxidized and / or modified with reactive functional groups such as maleic acid in the insulating film is the same as described above. If it is within the above range, it is easy to exhibit excellent physical properties of the 3-methyl-1-butene polymer such as heat resistance and chemical resistance.

[0158] 〈Melting point of resin composition〉

[0159] The melting point of the resin composition of this embodiment is preferably 260 to 310 °C. If the melting point of the resin composition is within the above range, it can be molded more easily, and in addition, the heat resistance to reflow can be further improved.

[0160] It should be noted that the melting point of the resin composition means the peak temperature measured by the same method as the measurement method of the melting point of the 3-methyl-1-butene polymer. Specifically, it can be measured by the measurement method of the melting point of the 3-methyl-1-butene polymer described in the examples.

[0161] From the viewpoint of the balance between processability and heat resistance, the melting point of the resin composition is preferably 270 to 305 °C, more preferably 280 to 305 °C, and still more preferably 280 to 300 °C.

[0162] It should be noted that the melting point of the resin composition of this embodiment is basically no different from the melting point of the 3-methyl-1-butene polymer. Therefore, in this specification, the melting point of the 3-methyl-1-butene polymer can be regarded as the melting point of the resin composition.

[0163] 〈Manufacturing method of resin composition〉

[0164] The manufacturing method of the resin composition of this embodiment is not particularly limited as long as it can manufacture a resin composition containing a 3-methyl-1-butene polymer. More specifically, the manufacturing method of the resin composition includes a step of obtaining a 3-methyl-1-butene polymer and a step of obtaining a resin composition. The details of each step can use the content described in [Step of obtaining 3-methyl-1-butene polymer] and [Step of obtaining resin composition] described later.

[0165] [Insulating film]

[0166] The insulating film of the present embodiment contains the resin composition of the present embodiment. The insulating film of the present embodiment contains a 3-methyl-1-butene-based polymer.

[0167] The insulating film of the present embodiment may be composed only of the resin composition, or may contain components other than the resin composition.

[0168] 〈Dielectric loss tangent〉

[0169] The dielectric loss tangent of the insulating film of the present embodiment means the dielectric loss tangent measured at a specific frequency. Specifically, it is the dielectric loss tangent measured at a frequency of 10 GHz to 300 GHz. The dielectric loss tangent of the insulating film of the present embodiment at a frequency of 10 GHz to 300 GHz is less than 0.00070. If the above dielectric loss tangent is 0.00070 or more, the transmission loss increases during the use of the millimeter-wave antenna in the millimeter-wave band, and the practicality of the millimeter-wave antenna may be impaired. From the viewpoint of further reducing the transmission loss, the above dielectric loss tangent is preferably 0.00060 or less, more preferably 0.00055 or less, and further preferably 0.00050 or less. The above dielectric loss tangent is preferably 0.00010 or more, more preferably 0.00013 or more, and further preferably 0.00015 or more. That is, the dielectric loss tangent of the insulating film at a frequency of 10 GHz to 300 GHz is preferably 0.00010 to 0.00060, more preferably 0.00013 to 0.00055, and further preferably 0.00015 to 0.00050.

[0170] It should be noted that the dielectric loss tangent of the insulating film at 10 GHz to 300 GHz means a value measured by a usual method such as the capacitance method, the resonance method, or the frequency change method. Specifically, it can be measured by the method described in the examples. When the frequency is 10 GHz or more and 50 GHz or less, it is preferably measured by the resonance method. When the frequency is greater than 50 GHz and 300 GHz or less, it is preferably measured by the frequency change method.

[0171] In one aspect, the tangent of the dielectric loss angle of the insulating film of the present embodiment at a frequency of 10 GHz measured by the resonance method is 0.00010 to 0.00060, preferably 0.00013 to 0.00055, and more preferably 0.00015 to 0.00050. In one aspect, the tangent of the dielectric loss angle of the insulating film of the present embodiment at a frequency of 100 GHz measured by the frequency variation method is 0.00010 to 0.00060, preferably 0.00013 to 0.00055, and more preferably 0.00015 to 0.00050. In one aspect, the tangent of the dielectric loss angle of the insulating film of the present embodiment at a frequency of 200 GHz measured by the frequency variation method is 0.00010 to 0.00060, preferably 0.00013 to 0.00055, and more preferably 0.00015 to 0.00050.

[0172] 〈Relative Dielectric Constant〉

[0173] The tangent of the dielectric loss angle of the insulating film of the present embodiment means the relative dielectric constant measured at a specific frequency. Specifically, it is the relative dielectric constant measured at a frequency of 10 GHz to 300 GHz. Regarding the relative dielectric constant of the insulating film of the present embodiment at a frequency of 10 GHz to 300 GHz, from an economic point of view, it is preferably 0.5 or more, more preferably 1.5 or more, and further preferably 2.0 or more. From the viewpoint of reducing transmission loss, the above relative dielectric constant is preferably 5.0 or less, more preferably 4.0 or less, more preferably 3.8 or less, and even more preferably 3.5 or less. That is, the relative dielectric constant of the insulating film at a frequency of 10 GHz to 300 GHz is preferably 0.5 to 5.0, more preferably 1.5 to 4.0, and further preferably 2.0 to 3.5.

[0174] It should be noted that the relative dielectric constant of the insulating film at 10 GHz to 300 GHz means the value measured by a usual method such as the capacitance method, the resonance method, or the frequency variation method. Specifically, it can be measured by the method described in the examples.

[0175] When the measurement wavelength is 10 GHz or more and 50 GHz or less, it is preferably measured by the resonance method. When the measurement frequency is greater than 50 GHz and 300 GHz or less, it is preferably measured by the frequency variation method.

[0176] In one mode, the relative dielectric constant of the insulating film of the present embodiment measured by the resonance method at 10 GHz is 0.5 to 5.0, preferably 1.5 to 4.0, and more preferably 2.0 to 3.5. In one mode, the relative dielectric constant of the insulating film of the present embodiment measured by the frequency change method at 100 GHz is 0.5 to 5.0, preferably 1.5 to 4.0, and more preferably 2.0 to 3.5. In one mode, the relative dielectric constant of the insulating film of the present embodiment measured by the frequency change method at 200 GHz is 0.5 to 5.0, preferably 1.5 to 4.0, and more preferably 2.0 to 3.5.

[0177] 〈Water absorption rate〉

[0178] The water absorption rate of the insulating film of the present embodiment is preferably 0.5% by mass or less, more preferably 0.3% by mass or less, and further preferably 0.1% by mass or less.

[0179] If the water absorption rate of the insulating film is within the above range, the occurrence of foaming during reflow soldering can be further suppressed. In addition, the storage management before reflow soldering becomes easier.

[0180] It should be noted that the water absorption rate of the insulating film means the value measured according to JIS K-7209:2000 Method A, and specifically, it can be measured by the method described in the examples.

[0181] <Manufacturing method of insulating film>

[0182] The manufacturing method of the insulating film of the present embodiment can adopt a known method and is not particularly limited.

[0183] The manufacturing method of the insulating film of the present embodiment preferably has a step of obtaining a 3-methyl-1-butene-based polymer and a step of obtaining an insulating film.

[0184] In addition, when other components such as an alkyl radical scavenger, an antioxidant, and other additives are further blended in addition to the 3-methyl-1-butene-based polymer to obtain a resin composition, it is preferable to go through the step of obtaining a resin composition described later.

[0185] [Step of obtaining a 3-methyl-1-butene-based polymer]

[0186] In the present embodiment, the process for obtaining a 3-methyl-1-butene polymer is not particularly limited as long as it is a process for obtaining a 3-methyl-1-butene polymer. As a method for obtaining a 3-methyl-1-butene polymer, there is no particular limitation, and well-known catalysts such as Ziegler-Natta catalysts and metallocene catalysts can be used for production. More specifically, the process for obtaining a 3-methyl-1-butene polymer is a process for obtaining a 3-methyl-1-butene polymer by preparing a raw material containing 3-methyl-1-butene and polymerizing the raw material. The method for obtaining a 3-methyl-1-butene polymer is, for example, as described in Japanese Patent Laid-Open No. 61-103910. In the presence of a catalyst, 3-methyl-1-butene is homopolymerized, or 3-methyl-1-butene is copolymerized with ethylene or the above α-olefin, whereby it can be obtained in the form of a powder. In the case of homopolymerization, the above raw material contains at least 3-methyl-1-butene and may further contain a catalyst. In the case of copolymerization, the above raw material contains at least 3-methyl-1-butene and ethylene or the above α-olefin and may further contain a catalyst.

[0187] In addition, the stereoregularity of the 3-methyl-1-butene polymer can be isotactic or syndiotactic.

[0188] [Process for obtaining a resin composition]

[0189] The process for obtaining a resin composition is a process for obtaining a resin composition by blending a 3-methyl-1-butene polymer and other components and mixing them. Specifically, it is a process for obtaining a resin composition containing a 3-methyl-1-butene polymer and other components. The 3-methyl-1-butene polymer and other components are mixed to obtain a resin composition. The mixing method is not particularly limited, and a method of melt-kneading using a twin-screw kneading extruder or the like can be used. In addition, the respective raw materials can be dry-blended before melt-kneading.

[0190] It should be noted that in the case where no other components other than the 3-methyl-1-butene polymer are blended, there is no need to go through the process for obtaining a resin composition.

[0191] As other components, the same substances as those described in the above [resin composition] can be cited. For example, alkyl radical scavengers, antioxidants, acid inhibitors, fillers, light stabilizers, antistatic agents, flame retardants, pigments, polymerization inhibitors, heavy metal passivators, ultraviolet absorbers, nucleating agents, clarifying agents, lubricants, fluorescent brighteners, rust inhibitors, slip agents, etc. can be cited.

[0192] 〈Melt-kneading conditions〉

[0193] The melt-kneading conditions are not particularly limited as long as the effects of the present invention are not impaired. It is preferable to perform melt-kneading in a low-oxygen state compared to the atmosphere, and it is more preferable to perform melt-kneading by injecting an inert gas into the interior of the melt-kneader or by performing decompression degassing on the interior of the melt-kneader.

[0194] In order to suppress the deterioration of the physical properties of the resin composition caused by oxygen and to produce an insulating film having more excellent dielectric properties and mechanical properties, it is preferable to perform melt-kneading in an inert atmosphere or a low-oxygen state.

[0195] Here, in the present embodiment, the so-called "low-oxygen state" is a state in which the oxygen concentration becomes lower than that before decompression degassing by performing decompression degassing on the interior of the melt-kneader. Or it is a state in which the oxygen concentration becomes lower than that before injection by injecting an inert gas such as nitrogen. In the "low-oxygen state", the oxygen concentration inside the melt-kneader is preferably 5% or less, more preferably 2% or less, and further preferably 1% or less. In addition, for the measurement of the above oxygen concentration, the value measured by an oxygen concentration meter using a diaphragm-type galvanic cell or the like is adopted.

[0196] For the method of performing melt-kneading by injecting an inert gas into the interior of the melt-kneader, for example, each component can be charged while injecting an inert gas into the interior of the melt-kneader for melt-kneading, or an inert gas can be injected after charging each component into the interior of the melt-kneader for melt-kneading. In addition, an inert gas can be continuously injected into the interior of the melt-kneader during melt-kneading.

[0197] The injection method of the inert gas can be carried out according to the equipment provided in each melt-kneader. For example, it can be carried out from the supply part of the inert gas or other gases provided in the melt-kneader, or from the supply part of each component provided in the melt-kneader, or from the exhaust port provided in the melt-kneader.

[0198] As long as the inert gas can be injected into the whole from the supply part of the inert gas to the heating part for melt-kneading for melt-kneading, the injection method is not limited.

[0199] Examples of the inert gas include nitrogen, helium, neon, argon, krypton, carbon dioxide gas, etc. From the viewpoints of high availability and versatility, nitrogen is preferred.

[0200] Regarding the method of performing melt-kneading by performing decompression degassing on the interior of the melt-kneader, for example, after charging each component into the interior of the melt-kneader, decompression degassing can be performed on the interior of the melt-kneader for melt-kneading. In addition, decompression degassing of the interior of the melt-kneader can be performed intermittently or continuously during melt-kneading.

[0201] The method of performing decompression degassing on the inside of the melt kneader can be carried out according to the equipment provided in each melt kneader. For example, it can be carried out from the vacuum exhaust port.

[0202] In the case of performing decompression degassing, the inside of the melt kneader can be set to a vacuum state of, for example, 0.1 kPa or more and 50 kPa or less.

[0203] As the melt kneader, a single-screw extruder, a multi-screw extruder, a kneader, a Banbury mixer, etc. equipped with equipment capable of injecting an inert gas into the inside of the melt kneader to perform melt kneading or equipment capable of performing melt kneading by performing decompression degassing on the inside of the melt kneader can be used.

[0204] The melt kneading temperature is preferably 300 to 380 °C.

[0205] If the melt kneading temperature is 300 °C or more, the 3-methyl-1-butene-based polymer can be sufficiently melted, and it is easy to disperse additives and the like. If the melt kneading temperature is 380 °C or less, decomposition of the 3-methyl-1-butene-based polymer and additives due to heat can be suppressed.

[0206] From the viewpoint of sufficiently dispersing the additives throughout the 3-methyl-1-butene-based polymer, the melt kneading temperature is more preferably 300 °C or more, and further preferably 310 °C or more.

[0207] In addition, from the viewpoint of suppressing significant decomposition of the raw materials, the melt kneading temperature is more preferably 380 °C or less, and further preferably 360 °C or less.

[0208] The melt kneading time can be adjusted according to the size of the kneading device, etc. For example, it can be 1 to 15 minutes, but is not limited to this numerical range of the melt kneading time. In addition, in the present embodiment, regarding the "melt kneading time", in the case of a batch kneader, it represents the time of the rotary mixer, and in the case of a continuous extrusion kneader, it represents the residence time of the raw materials in the device.

[0209] The rotational speed of the mixer during melt kneading can be 80 rpm or more or 100 rpm or more, and can also be 300 rpm or less or 250 rpm or less.

[0210] After melt kneading, the resin composition is taken out from the melt kneader and cooled.

[0211] [Process of obtaining an insulating film]

[0212] In the present embodiment, the process of obtaining an insulating film is a process of obtaining an insulating film by forming the material used for the insulating film.

[0213] Examples of the method for forming an insulating film from the above materials include extrusion molding, hot pressing, etc.

[0214] In the present embodiment, an insulating film can be used as a millimeter-wave antenna substrate. When using an insulating film as a millimeter-wave antenna substrate, the shape of the millimeter-wave antenna substrate is selected according to the components using the millimeter-wave antenna, performance, etc.

[0215] The thickness of the millimeter-wave antenna substrate can be, for example, 0.01 to 5 mm.

[0216] <Copper-clad laminate and millimeter-wave antenna>

[0217] In the present embodiment, when using an insulating film as a millimeter-wave antenna substrate, the insulating film preferably includes a conductive layer on the surface. That is, in the present embodiment, it can be used as a millimeter-wave antenna including an insulating film and a conductive layer. The conductive layer functions as an electrode. The conductive layer contains a conductive material. As the conductive material, as long as it is conductive, for example, it can include a metal material, a carbon-based conductive material. As the metal material, metal materials such as copper, silver, gold, and aluminum or alloys using them can be cited. In the present embodiment, the method for forming the conductive layer on the insulating film is not particularly limited, and plating methods, printing methods, sputtering methods, evaporation methods, etc. can be cited. In the present embodiment, the conductive layer can also be formed using a metal foil. Specifically, the insulating film can have a metal foil on the surface. As the metal foil, the aforementioned metal materials can be used, and metal foils containing copper, silver, gold, and aluminum can be used. In the present embodiment, from the viewpoint of conductivity, a copper foil is preferably used. That is, in the present embodiment, it is preferable to have an insulating film and a copper foil, and more preferably a copper-clad laminate in which a copper foil is laminated on the surface layer of the insulating film.

[0218] The copper-clad laminate of the present embodiment includes the above-mentioned insulating film. Since the above-mentioned insulating film has excellent dielectric properties and other properties as described above, the above-mentioned copper-clad laminate can be used, for example, for millimeter-wave antennas, semiconductor substrates, base station substrates, etc. Among them, the above-mentioned copper-clad laminate can be suitably used for millimeter-wave antennas. Thus, the millimeter-wave antenna of the present embodiment includes the above-mentioned copper-clad laminate.

[0219] The copper-clad laminate preferably has a copper foil on the surface of the insulating film. Specifically, the copper-clad laminate can have a copper foil on at least one or both sides of the insulating film. In addition, the number of copper foils and insulating films in the copper-clad laminate is not particularly limited.

[0220] It should be noted that when using the copper-clad laminate for a millimeter-wave antenna, the insulating film contained in the copper-clad laminate functions as a millimeter-wave antenna substrate, and the copper foil functions as an electrode.

[0221] A method of disposing a copper foil on the surface of an insulating film can adopt a known method, for example, an etching method, a sputtering method, a vacuum evaporation method, etc. can be cited.

[0222] In addition, a copper-clad laminate can be fabricated by overlapping the above copper foil on one or both surfaces of the insulating film and performing hot pressing.

[0223] The conditions for hot pressing are not particularly limited. The pressing temperature can be 200 to 350 °C, and the pressing pressure can be 50 to 150 f / cm 2 .

[0224] The thickness of the copper foil disposed on the surface of the insulating film is, for example, 0.1 to 100 μm.

[0225] Before disposing the copper foil on the surface of the insulating film, pretreatment such as degreasing treatment, plasma treatment, UV ozone treatment, laser treatment, etc. can be performed on the surface of the insulating film. The treatment conditions of the above pretreatment are not limited as long as the effects of the present invention are not impaired.

[0226] <Usage of Millimeter-Wave Antenna>

[0227] The millimeter-wave antenna of the present embodiment is an antenna that can be suitably used for frequencies from 30 GHz to 300 GHz (i.e., millimeter waves). However, as long as the effects of the present invention are not impaired, the usable frequencies are not limited to millimeter waves.

[0228] The millimeter-wave antenna of the present embodiment is formed by including an insulating film having a low relative dielectric constant, a low dielectric loss tangent, and excellent moldability. Even when used in the frequency band of several tens of GHz, transmission loss is not likely to occur. In addition, the millimeter-wave antenna of the present embodiment has excellent reflow heat resistance. Thus, the millimeter-wave antenna of the present embodiment can be used for short-range wireless communication applications, in-vehicle radar applications such as in automobiles, mobile phones, PHS, smartphones, tablet computers (tablet PCs), mobile computers (mobile PCs), portable information terminals (PDAs), etc.

[0229] Examples

[0230] Hereinafter, the present invention will be specifically described using examples and comparative examples. However, the present invention is not limited to them.

[0231] <Measurement and Evaluation Methods>

[0232] Using the following methods, various physical properties are measured or evaluated.

[0233] [Content Ratio of Structural Units Derived from Comonomers]

[0234] Regarding the content ratio of the structural units derived from α-olefins other than 3-methyl-1-butene, namely 1-decene (comonomer), in the copolymers (3-methyl-1-butene-based polymers) obtained in Production Examples 1 and 2, using FT-IR (manufactured by Ailent Technologies, model name "cary 600 series FTIR spectrometer") as the analytical device, IR measurement was performed by the ATR method and calculated as follows.

[0235] Based on the ratio of the peak area of the angular vibration of the main-chain methylene of the 3-methyl-1-butene homopolymer at 1461 cm -1 to the peak area of the angular vibration of the side-chain methylene of the α-olefin homopolymer at 727 cm -1 and the addition ratio of each polymer, a standard curve was prepared. The above IR measurement was performed on the copolymers obtained in Production Examples 1 and 2, and the obtained measured value (ratio of peak areas) was inserted into the above standard curve to determine the content ratio of the structural units derived from α-olefins other than 3-methyl-1-butene (1-decene).

[0236] [Melting point]

[0237] For the copolymers or homopolymers (3-methyl-1-butene-based polymers) obtained in Production Examples 1 to 3, using a differential scanning calorimeter ("DSC25" manufactured by TA Instrument), under a nitrogen flow rate (100 mL / min), the temperature was raised from 30 °C to 320 °C at a rate of 10 °C / min, held at 320 °C for 5 minutes, and then cooled to -70 °C at a rate of 10 °C / min. The peak temperature of the endothermic peak accompanying melting was measured when the temperature was raised from -70 °C to 320 °C at a rate of 10 °C / min after holding at -70 °C for 5 minutes, and this temperature was defined as the melting point.

[0238] [Melt viscosity]

[0239] Regarding the melt viscosity (Pa·s) of the copolymers or homopolymers (3-methyl-1-butene-based polymers) obtained in Production Examples 1 to 3, using a capillary rheometer ("Capilography 1C" manufactured by Toyo Seiki Seisaku-sho, Ltd.), the measurement was performed under the conditions of a barrel temperature of 320 °C and a shear rate of 1220 sec -1 (capillary: inner diameter 1.0 mm × length 10 mm, extrusion speed 10 mm / min).

[0240] [Melt formability]

[0241] An evaluation was made on whether it was possible to manufacture an insulating film (length: 1000 mm, width: 80 mm, thickness: 0.5 mm) by extrusion molding.

[0242] For the resin compositions obtained in Examples 1 to 4, the resin composition obtained in Comparative Example 1, and the resin of Comparative Example 3, extrusion molding was carried out under the conditions described in Examples 1 to 4 and Comparative Examples 1 and 3 below. For the resin of Comparative Example 2, extrusion molding was carried out under the same conditions as in Example 1 except that the barrel temperature was 380°C. The case where the above insulating film could be formed was designated as "A", and the case where it could not be formed was designated as "B".

[0243] [Mechanical Strength]

[0244] Test pieces (length: 150 mm, width: 25 mm, thickness: 0.5 mm) were cut out from the insulating films used in Examples 1 to 4 and Comparative Example 1. Using these test pieces, after storing them for 24 hours or more under the conditions of 23°C and a humidity of 49%, the yield stress (MPa) was measured at a tensile speed of 100 mm / min under the conditions of 23°C and a humidity of 49% using a universal material testing machine "INSTRON 5900R-5666" (manufactured by Instron Corporation) in accordance with JIS K 7161-1:2014. The measurement was carried out 5 times for each, and the average value was adopted.

[0245] Test pieces with a yield stress of 27 MPa or more were designated as "A", and test pieces with a yield stress less than 27 MPa were designated as "B".

[0246] [Specific Gravity]

[0247] Test pieces (length: 60 mm, width: 60 mm, thickness: 0.5 mm) were cut out from the insulating films used in Examples 1 to 4 and Comparative Examples 1 to 3. Using these test pieces, the specific gravity was measured in accordance with Method A of JIS K 7112:1999.

[0248] [Water Absorption Rate]

[0249] Test pieces (length: 60 mm, width: 60 mm, thickness: 0.5 mm) were cut out from the insulating films used in Examples 1 to 4 and Comparative Examples 1 to 3. Using these test pieces, the water absorption rate was measured in accordance with Method A of JIS K 7209:2000.

[0250] [Relative Dielectric Constant and Dielectric Dissipation Factor]

[0251] Test pieces (length: 40 mm, width: 40 mm, thickness: 0.5 mm) were cut out from the insulating films used in Examples 1 to 4 and Comparative Examples 1 to 3. Using these test pieces, the relative dielectric constant and dielectric dissipation factor at a measurement frequency of 10 GHz were measured by the perturbed cavity resonance method using a vector network analyzer "Keysight E8361A" (manufactured by Agilent Technologies).

[0252] In addition, the insulating films used in Examples 1 to 4 and Comparative Example 1 were cut out, and test pieces (length: 40 mm, width: 40 mm, thickness: 0.5 mm) were produced. Using these test pieces, the relative dielectric constant and the tangent of the dielectric loss angle at a measurement frequency of 100 GHz were measured by the frequency variation method using a millimeter wave module (manufactured by Virginia Diodes Inc., WR1067 GHz - 115 GHz).

[0253] In addition, the insulating films used in Examples 1 to 4 and Comparative Example 1 were cut out, and test pieces (length: 40 mm, width: 40 mm, thickness: 0.5 mm) were produced. Using these test pieces, the relative dielectric constant and the tangent of the dielectric loss angle at a measurement frequency of 200 GHz were measured by the frequency variation method using a vector network analyzer (Anritsu ME7838G 70 kHz - 220 GHz).

[0254] [Reflow heat resistance]

[0255] The millimeter wave antennas obtained in Examples 1 to 4 and Comparative Examples 1 to 3 were left standing in an atmosphere of 85°C and 85% RH for 7 days. For the standing millimeter wave antennas, after heat treatment was performed using a high-temperature observation device "SMT Scope Light SL-1" (manufactured by Sanyo Seiko Co., Ltd.) according to the following reflow temperature curve, the appearance of the millimeter wave antennas was observed and evaluated. Specifically, in terms of warping, melting, and blistering, for a millimeter wave antenna in which at least 1 was found to occur, it was designated as "B", and for a millimeter wave antenna in which none were found to occur, it was designated as "A".

[0256] Reflow temperature curve: It was heated from 25°C to 150°C in 60 seconds, then heated to 180°C in 80 seconds, and then heated to 280°C in 60 seconds, and held at 280°C for 10 seconds. Subsequently, air cooling was performed.

[0257] [Preparation of catalyst]

[0258] Preparation of titanium catalyst component

[0259] 47.6 g (500 mmol) of anhydrous magnesium chloride, 250 ml of decane, and 234 ml (1.5 mol) of 2-ethylhexanol were heated and reacted at 130 °C for 2 hours to prepare a homogeneous solution. After cooling the obtained homogeneous solution to room temperature (23 °C), it was added dropwise to 2 L (18 mol) of titanium tetrachloride maintained at -20 °C over 1 hour. After the dropwise addition was completed, the temperature of the mixed solution was raised to 90 °C over 2 hours. When the temperature reached 90 °C, 11.4 mL (80 mmol) of ethyl benzoate was added, and the mixture was stirred at the same temperature for 2 hours while maintaining the temperature. After the 2-hour reaction was completed, the mixture was allowed to stand, and then the supernatant was removed. Decane and hexane were added thereto, and the solid component was washed 3 times and then resuspended in 2 L of titanium tetrachloride, and the heating reaction was carried out again at 90 °C for 2 hours. After the reaction was completed, the mixture was allowed to stand again using decane and hexane, and the removal of the supernatant was repeated until no free titanium compound was detected in the washing liquid. The obtained suspended component was dried under reduced pressure at room temperature for 6 hours to obtain a titanium catalyst component.

[0260] The composition of the obtained titanium catalyst component was 4.0 mass% of titanium, 56.0 mass% of chlorine, 17.0 mass% of magnesium, 10.4 mass% of ethyl benzoate, and 12.6 mass% of a hydrocarbon solvent containing decane and hexane.

[0261] [Production Example 1]

[0262] Production of copolymer (A)

[0263] Into a 20 L stainless steel autoclave, 8.0 kg of 3-methyl-1-butene, 0.6 kg of 1-decene, 50 g of triethylaluminum diluted to a concentration of 1 mol / L with hexane, and 4 g of the titanium catalyst component produced in the above [Preparation of catalyst] were added, and a polymerization reaction was carried out at 70 °C for 4 hours. During the polymerization reaction, hydrogen was continuously supplied at a rate of 40 mL / minute. After 4 hours, 200 g of 3-methyl-1-butanol was pressed in, the reaction was stopped, and the remaining unreacted monomers were removed. Then, 2 kg of n-heptane was introduced, and the mixture was stirred at 60 °C for 30 minutes, and then the solid component was filtered off using a pressure filter. After repeating this operation 2 times, the solvent was changed from 2 kg of n-heptane to 3 kg of 2-propanol, and the same operation was repeated 2 times.

[0264] 7.7 kg of the obtained crude polymer was placed in a 50-L container equipped with a stirrer. Thereafter, 8 kg of 1 mol / L hydrochloric acid and 16 kg of 2-propanol were added, and the mixture was stirred for 1 hour. The suspension was separated by filtration under reduced pressure and washed with 10 kg of 2-propanol. The crude polymer was placed in a 50-L container equipped with a stirrer. Thereafter, 20 kg of 2-propanol was added, and the mixture was stirred for 1 hour. The suspension was separated by filtration under reduced pressure and washed with 10 kg of 2-propanol. The obtained washed polymer was dried under reduced pressure at 80 °C for 2 days, whereby 3.2 kg of copolymer (A) as a copolymer of 3-methyl-1-butene and 1-decene was obtained.

[0265] The above-mentioned measurement was carried out on the obtained copolymer (A). As a result, the melting point was 286 °C and the melt viscosity was 104 Pa·s. In addition, the content ratio of the structural unit derived from 1-decene as a comonomer in copolymer (A) was 1.1 mol%.

[0266] [Production Example 2]

[0267] Production of copolymer (B)

[0268] The same operation as in Production Example 1 was carried out except that 0.6 kg of 1-decene was changed to 3.6 kg of 1-decene, whereby 2.8 kg of copolymer (B) as a copolymer of 3-methyl-1-butene and 1-decene was obtained.

[0269] The above-mentioned measurement was carried out on the obtained copolymer (B). As a result, the melting point was 281 °C and the melt viscosity was 99 Pa·s. In addition, the content ratio of the structural unit derived from 1-decene as a comonomer in copolymer (B) was 6.4 mol%.

[0270] [Production Example 3]

[0271] Production of homopolymer (C)

[0272] The same operation as in Production Example 1 was carried out except that 0.6 kg of 1-decene was not added, whereby 3.3 kg of homopolymer (C) as a homopolymer of 3-methyl-1-butene was obtained.

[0273] The above-mentioned measurement was carried out on the obtained homopolymer (C). As a result, the melting point was 305 °C and the melt viscosity was 126 Pa·s.

[0274] [Example 1]

[0275] (1) Production of resin composition

[0276] In 100 parts by mass of the copolymer (A) obtained in Production Example 1, 0.2 part by mass of pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (“AO-60”, manufactured by ADEKA Corporation) as a phenolic antioxidant, 0.2 part by mass of 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane (“PEP-36”, manufactured by ADEKA Corporation) as a phosphorus-based antioxidant, 0.1 part by mass of 2,4-di-tert-amyl-6-[1-(3,5-di-tert-amyl-2-hydroxyphenyl)ethyl]phenyl acrylate (“SUMILIZER (registered trademark) GS”, manufactured by Sumitomo Chemical Company, Limited) as an alkyl radical scavenger (acrylic phenolic compound), and 0.25 part by mass of zinc stearate (acid inhibitor) were dry-blended, and then melt-kneaded in a nitrogen atmosphere using a twin-screw kneading extruder “KZW15-45” (manufactured by Technobel Co., Ltd.) to obtain a resin composition (M1) in the form of pellets.

[0277] Manufacture of millimeter-wave antenna

[0278] The obtained resin composition (M1) in the form of pellets was melt-kneaded in a nitrogen atmosphere at a barrel temperature of 310°C using a twin-screw kneading extruder “KZW15-45” (manufactured by Technobel Co., Ltd.) and melt-extruded in a film form from a T-die. Then, the obtained film was cooled and solidified on a cooling roll at 110°C to obtain an insulating film with a thickness of 0.5 mm.

[0279] After subjecting the above insulating film to plasma treatment, copper foils with a thickness of 35 μm were laminated on both sides, and hot pressing was performed at 300°C at 70 kgf / cm 2 to produce a copper-clad laminate, and a millimeter-wave antenna was obtained.

[0280] The results evaluated according to the above evaluation method are shown in Table 1.

[0281] [Example 2]

[0282] (1) Manufacture of resin composition

[0283] In 100 parts by mass of the copolymer (A) obtained in Production Example 1, 0.2 part by mass of pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (“AO-60”, manufactured by ADEKA Corporation) as a phenolic antioxidant, 0.2 part by mass of 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane (“PEP-36”, manufactured by ADEKA Corporation) as a phosphorus-based antioxidant, and 0.25 part by mass of zinc stearate (acid inhibitor) were dry-blended, and then melt-kneaded using a twin-screw kneading extruder “KZW15-45” (manufactured by Technobel Co., Ltd.) under a nitrogen atmosphere to obtain a resin composition (M2) in the form of pellets.

[0284] Manufacture of millimeter-wave antenna

[0285] The obtained resin composition (M2) in the form of pellets was melt-kneaded using a twin-screw kneading extruder “KZW15-45” (manufactured by Technobel Co., Ltd.) under a nitrogen atmosphere at a barrel temperature of 310°C and melt-extruded in a film form from a T-die. Then, the obtained film was cooled and solidified on a cooling roll at 110°C to obtain an insulating film with a thickness of 0.5 mm.

[0286] After subjecting the above insulating film to plasma treatment, copper foils with a thickness of 35 μm were laminated on both sides, and hot pressing was performed at 300°C under 70 kgf / cm 2 to produce a copper-clad laminate, obtaining a millimeter-wave antenna.

[0287] The results evaluated according to the above evaluation method are shown in Table 1.

[0288] [Comparative Example 1]

[0289] Manufacture of resin composition

[0290] In 100 parts by mass of the copolymer (A) obtained in Production Example 1, 0.67 part by mass of pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (“AO-60”, manufactured by ADEKA Corporation) as a phenolic antioxidant, 1.33 parts by mass of 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane (“PEP-36”, manufactured by ADEKA Corporation) as a phosphorus-based antioxidant, and 0.25 part by mass of zinc stearate (acid inhibitor) were dry-blended, and then melt-kneaded using a twin-screw kneading extruder “KZW15-45” (manufactured by Technobel Co., Ltd.) under an air atmosphere to obtain a resin composition (M3) in the form of pellets.

[0291] Manufacture of millimeter-wave antenna

[0292] The obtained granular resin composition (M3) was melt-kneaded using a twin-screw kneading extruder "KZW15-45" (manufactured by Technobel Co., Ltd.) in an air atmosphere at a barrel temperature of 310°C, and melt-extruded in a film shape from a T-die. Then, the obtained film was cooled and solidified on a cooling roll at 110°C to obtain an insulating film with a thickness of 0.5 mm.

[0293] After subjecting the above insulating film to plasma treatment, copper foils with a thickness of 35 μm were laminated on both sides, and hot pressing was performed at 300°C under 70 kgf / cm 2 to fabricate a copper-clad laminate and obtain a millimeter-wave antenna.

[0294] The results evaluated according to the above evaluation method are shown in Table 1.

[0295] [Example 3]

[0296] Except for using the copolymer (B) obtained in Production Example 2 instead of the copolymer (A), a resin composition (M4), an insulating film, and a millimeter-wave antenna were fabricated in the same manner as in Example 1.

[0297] The results evaluated according to the above evaluation method are shown in Table 1.

[0298] [Example 4]

[0299] Except for using the homopolymer (C) obtained in Production Example 3 instead of the copolymer (A), a resin composition (M5), an insulating film, and a millimeter-wave antenna were fabricated in the same manner as in Example 1.

[0300] The results evaluated according to the above evaluation method are shown in Table 1.

[0301]

[0302] [Comparative Example 2]

[0303] PTFE "POLYFLON (registered trademark) M12" (manufactured by DAIKIN INDUSTRIES, LTD.) was put into a mold with a side length of 100 mm and a compression molding die with a die length of 500 mm, and compression molding was performed using a compression molding machine (manufactured by Kando Metal Industry Co., Ltd., AYS10) at room temperature and a molding pressure of 200 kgf / cm 2 for 10 minutes under a holding pressure. By the above compression molding, it was formed into a sheet with a thickness of 0.5 mm and fired in an electric furnace at 370°C to obtain an insulating film.

[0304] After subjecting the above-mentioned insulating film to plasma treatment in the same manner as in Example 1, copper foils with a thickness of 35 μm were laminated on both sides, and hot pressing was carried out at 380 °C under 70 kgf / cm 2 to produce a copper-clad laminate, obtaining a millimeter-wave antenna.

[0305] The results evaluated according to the above evaluation method are shown in Table 2.

[0306] [Comparative Example 3]

[0307] Instead of the resin composition (M1), poly-4-methyl-1-pentene "TPX (registered trademark) MX0020" (manufactured by Mitsui Chemicals, Inc.) was used, the barrel temperature was set at 270 °C, and cooling and curing were carried out on a cooling roll at 80 °C. Otherwise, an insulating film with a thickness of 0.5 mm in the form of a sheet was obtained in the same manner as in Example 1.

[0308] After subjecting the above-mentioned insulating film to plasma treatment in the same manner as in Example 1, copper foils with a thickness of 35 μm were laminated on both sides, and hot pressing was carried out at 300 °C under 70 kgf / cm 2 to produce a copper-clad laminate, obtaining a millimeter-wave antenna.

[0309] The results evaluated according to the above evaluation method are shown in Table 2.

[0310]

[0311] As can be seen from Table 1, the insulating films of Examples 1 to 4 are made of a material containing a 3-methyl-1-butene-based polymer, and the tangent of the dielectric loss angle at 10 GHz to 300 GHz is less than 0.00070, so the dielectric properties are excellent. In addition, it can be seen that in Examples 1, 3, and 4, since the above material contains an alkyl radical scavenger, the mechanical strength is "A", and the mechanical properties of the insulating film are more excellent. On the other hand, although the insulating film of Comparative Example 1 is made of a material containing a 3-methyl-1-butene-based polymer, the tangent of the dielectric loss angle at 10 GHz to 300 GHz is 0.00070 or more, and the dielectric properties are poor compared with Examples 1 to 4. It is considered that the material containing the 3-methyl-1-butene-based polymer in Comparative Example 1 requires a large amount of antioxidant to prevent the deterioration of physical properties caused by oxygen, and excellent dielectric properties cannot be exhibited.

[0312] According to Table 2, the melt formability in Comparative Example 2 is "B", and the tangent of the dielectric loss angle in Comparative Example 3 is 0.00070 or more and the reflow heat resistance is "B". Therefore, Comparative Examples 2 and 3 are not excellent in all aspects of dielectric properties, formability, and reflow heat resistance.

[0313] As can be seen from Tables 1 and 2, the millimeter-wave antenna of this embodiment has excellent reflow heat resistance. In addition, the insulating film of this embodiment has a low relative dielectric constant and a low dielectric loss tangent, and excellent dielectric properties. It can be said that the millimeter-wave antenna made of this insulating film also has the same characteristics. In addition, the material used in the above insulating film has excellent formability, so the productivity is high. Furthermore, since the material used in the insulating film of this embodiment has a low water absorption rate, the possibility of blistering during reflow or the generation of blisters is reduced, storage management is easy, and the performance degradation is small even in a humid and hot environment.

Claims

1. An insulating film containing a material comprising a 3-methyl-1-butene polymer, having a dielectric loss tangent of less than 0.00070 at 10 GHz to 300 GHz.

2. The insulating film according to claim 1, wherein the 3-methyl-1-butene polymer is at least one selected from a 3-methyl-1-butene homopolymer and a copolymer of 3-methyl-1-butene and ethylene or an α-olefin, and the α-olefin has 3 to 20 carbon atoms.

3. The insulating film according to claim 2, wherein the content ratio of the structural unit derived from the ethylene or the α-olefin in the copolymer is more than 0 mol% and 20 mol% or less.

4. The insulating film according to claim 2 or 3, wherein the content ratio of the structural unit derived from the ethylene or the α-olefin in the copolymer is more than 0 mol% and 10 mol% or less.

5. The insulating film according to any one of claims 1 to 4, wherein the melting point of the 3-methyl-1-butene polymer is 260 °C to 310 °C.

6. The insulating film according to any one of claims 1 to 5, wherein the material is a resin composition containing the 3-methyl-1-butene polymer and an alkyl radical scavenger.

7. The insulating film according to claim 6, wherein the alkyl radical scavenger contains at least one selected from an acrylic phenolic compound and a benzofuranone compound.

8. A copper-clad laminate comprising the insulating film according to any one of claims 1 to 7.

9. A millimeter-wave antenna comprising the copper-clad laminate according to claim 8.

10. A millimeter-wave antenna comprising the insulating film according to any one of claims 1 to 7.

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