JP2016127429A - Composite for shielding and high-frequency transmission member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shield member easy in mounting and processing work to a high-frequency transmission path, and capable of providing excellent shielding properties and flex resistance to a high-frequency transmission member.SOLUTION: A composite 10 for shielding is formed in a long tape-like shape, and has a structure where a resin layer 11 of a resin film and a metal layer 12 are laminated. In a radio wave hose 20, the long composite 10 for shielding coats a flexible tube 21 by being wound on the outer periphery of the flexible tube 21 such that the longitudinal direction thereof has a predetermined angle, not a right angle, with respect to the longitudinal direction of the flexible tube 21 while the position thereof is shifted in the longitudinal direction of the flexible tube 21, for example, by half pitches, in a width direction thereof.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a shield composite applied to a shield of a transmission line that transmits a high frequency such as millimeter waves, and a high frequency transmission member using the same.

  Transmission members such as waveguides and coaxial cables are used for high-frequency transmission. A waveguide is suitable for high-frequency transmission from microwaves to millimeter waves, but is generally made of metal and has a problem of lack of flexibility. For this reason, flexible waveguides having a bellows-like connection part (Patent Document 1), a metal tape spirally wound around the surface of a dielectric rod (Patent Document 2), and the like have been proposed. ing. A waveguide in which metal plating is applied to the inner surface of a hollow path made of resin is also known (Patent Document 3).

  A coaxial cable has advantages that it is flexible, inexpensive, and has a wide applicable frequency band. In order to obtain good high frequency shielding characteristics in a coaxial cable, a tubular metal coating layer obtained by shaping a long ribbon-shaped metal foil into a tubular shape in the longitudinal direction as an outer conductor, and a molten metal plating layer on the outer periphery of the metal coating layer Has been proposed (Patent Document 4). Moreover, what has the single-sided conductor plastic film which has the metal foil vertically attached to the axial direction of a cable as an external conductor, and the braid provided in the outer side is proposed (patent document 5).

  On the other hand, as a high-frequency transmission member that replaces a coaxial cable, there has been proposed a radio hose that forms a transmission path by providing a metal layer by coating or vapor deposition of metal fine particles on the surface of a hollow resin hose (Non-Patent Document 1). . Since this radio hose is lightweight and flexible, it is possible to construct a highly reliable millimeter-wave wireless LAN. Instead of a heavy wire harness, it is used between the ECU (Electric Control Unit) of the automobile. Expected as a means of communication.

Japanese Patent No. 2800636 JP-A-8-195605 JP 2003-23308 A JP-A-8-241633 Japanese Patent No. 3671729

Shuzo Kato, “Lightweight and highly reliable radio hose that connects ECUs wirelessly”, Nikkei Electronics (Nikkei BP) 2014.4, 14, pp. 67-76

  In a wireless communication means such as a radio hose, enhancing the high frequency shielding property also contributes to a reduction in transmission loss. However, for example, when a metal layer is formed by applying metal fine particles to the surface of a resin hose, it is necessary to increase the thickness of the metal layer in order to keep the characteristic impedance low. It is thought to decline. In addition, when a metal layer is formed on the surface of the resin hose by vapor deposition, it is difficult to form a metal film with a uniform thickness on the curved surface, and it is necessary to increase the thickness in order to increase resistance to bending. There is a problem that processing takes time.

  In addition, when applying a method of covering and arranging a long metal foil along the axial direction as described in Patent Documents 4 and 5 to the radio wave hose, if the metal foil is made thin, it is durable against bending. It is feared that the handling property is lowered, and if it is thick, it is difficult to bend and becomes heavy, so that there is a concern that the handling property is lowered.

  Accordingly, an object of the present invention is to provide a shield member that can be easily mounted on a high-frequency transmission line and can provide excellent shielding properties and bending resistance to the high-frequency transmission member.

  The composite for shielding according to the present invention includes a long resin film and a conductive material integrated with the resin film. And the composite body for shielding of this invention shields a high frequency with respect to the transmission member which transmits a high frequency by spirally winding so that an overlapping area | region may be partially formed from the outer side.

  In the shielding composite of the present invention, the conductive material may be a metal layer laminated on the resin film.

  The shield composite according to the present invention includes a strip-shaped laminated portion in which the metal layer is laminated in a short direction perpendicular to the longitudinal direction of the resin film, and a belt-like non-laminated portion in which the metal layer is not laminated. , May be included.

  The shield composite of the present invention includes a plurality of the metal layers, and a circuit portion processed by circuit wiring is provided on a metal layer of the metal layers excluding the innermost metal layer in a wound state. It may be.

  In the shield composite of the present invention, the resin film may be made of polyimide.

  A high-frequency transmission member according to one aspect of the present invention includes a long and hollow flexible tube, and the shield composite according to any one of the above, wound around an outer periphery of the flexible tube. Have.

  A high-frequency transmission member according to another aspect of the present invention includes an inner conductor, an insulating resin portion covering the inner conductor, and the shielding composite according to any one of the above wound around the outer periphery of the insulating resin portion, Have

  The shield composite of the present invention has a simple structure having a resin film and a conductive material integrated with the resin film, and can be easily attached to a high-frequency transmission line. And the composite body for shielding of this invention can give the shielding property and bending resistance which were excellent in the high frequency transmission member. Therefore, by applying the shield composite of the present invention as a shield member of a high-frequency transmission member such as a radio wave hose or a coaxial cable, a high-frequency transmission member having excellent shielding properties and bending resistance can be provided.

It is a perspective view which shows the external appearance of the state which wound up the composite body for shielding which concerns on the 1st Embodiment of this invention. It is principal part sectional drawing of the example of 1 structure of the composite body for shielding which concerns on the 1st Embodiment of this invention. It is principal part sectional drawing of another structural example of the composite body for shielding which concerns on the 1st Embodiment of this invention. It is principal part sectional drawing of another structural example of the composite_body | complex for the shield which concerns on the 1st Embodiment of this invention. It is explanatory drawing which shows the state which applies the composite body for shielding which concerns on the 1st Embodiment of this invention to a radio wave hose. It is principal part sectional drawing which shows the application example of the composite_body | complex for the shield which concerns on the 1st Embodiment of this invention. It is explanatory drawing which shows the coaxial cable as a high frequency transmission member to which the composite body for shielding which concerns on the 1st Embodiment of this invention is applied. It is a perspective view which shows the external appearance of the state which wound up the composite body for shielding which concerns on the 2nd Embodiment of this invention. It is explanatory drawing which shows the state which applies the composite body for shielding which concerns on the 2nd Embodiment of this invention to a radio wave hose. It is a perspective view which shows the external appearance of another structural example of the composite_body | complex for a shield which concerns on the 2nd Embodiment of this invention. It is a perspective view which shows the external appearance of another structural example of the composite_body | complex for the shield which concerns on the 2nd Embodiment of this invention.

[First Embodiment]
The shield composite 10 according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing an appearance of a shield composite 10 in a wound state, and FIGS. 2 to 4 are main part cross-sectional views of a typical configuration example of the shield composite 10. The shield composite 10 has a long tape shape and has a structure in which a resin layer 11 and a metal layer 12 which are resin films are laminated. FIG. 2 shows the composite 10 for shielding in which the resin layer 11 and the metal layer 12 are formed on one side of the resin layer 11. FIG. 3 shows a composite 10 for shielding in which a resin layer 11 and metal layers 12 are formed on both sides of the resin layer 11. FIG. 4 shows the shield composite 10 in which the metal layer 12 and the resin layers 11 are formed on both sides of the metal layer 12. The shield composite 10 is not limited to two or three layers, but may have a structure in which four or more layers are laminated.

<Radio wave hose>
FIG. 5 is an explanatory view showing a state in which the shield composite 10 is applied as a shield member in the radio wave hose 20 as a high-frequency transmission member. The radio wave hose 20 includes a hollow flexible tube 21 and a shield composite 10 wound around the flexible tube 21 spirally from the outside. The material of the flexible tube 21 is not particularly limited. For example, polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), ethylene / vinyl acetate copolymer resin (EVA), isoprene rubber, ethylene Propylene diene (EPDM) rubber, silicone rubber, or the like can be used. The metal layer 12 of the shielding composite 10 shields electromagnetic waves (for example, millimeter waves, microwaves, etc.) transmitted through the internal space of the flexible tube 21.

  As shown in FIG. 5, the tape-shaped shielding composite 10 is spirally wound around the flexible tube 21 so as to be partially overlapped inside and outside. That is, the long shield composite 10 has a longitudinal direction that is not perpendicular to the major axis direction of the flexible tube 21 but has a predetermined angle, and is, for example, 1 / While being displaced in the major axis direction of the flexible tube 21 by two pitches, the flexible tube 21 is wound around and covered with the outer periphery of the flexible tube 21. In this way, by winding the shielding composite 10 in a spiral shape so that a partially overlapped region is formed, the bending resistance when the radio wave hose 20 is folded is improved, and the folded state is obtained. However, excellent shielding performance can be ensured. Since the shield composite 10 has a structure in which the resin layer 11 and the metal layer 12 are laminated and integrated in advance, peeling hardly occurs between them and has excellent bending resistance.

  The area in which the shield composite 10 is partially overlapped when wound around the flexible tube 21 is not limited to about ½ width, for example, preferably within a range of 1/5 to 4/5 in the width direction. Can be appropriately set within the range of 2/5 to 3/5 according to the outer diameter of the flexible tube 21, the use state of the radio wave hose 20, the application, and the like.

  When the shield composite 10 has a two-layer laminated structure as shown in FIG. 2, the flexible tube 21 may be wound with the metal layer 12 inside or the resin layer 11 inside. May be. When the resin layer 11 is on the inner side, since the metal layer 12 is on the outer side, a protective layer (not shown) such as a resin film may be further provided on the outer side.

  When the shield composite 10 has a three-layer structure of the first metal layer 12 / resin layer 11 / second metal layer 12 as shown in FIG. Since the second metal layer 12 is on the outermost side, a protective layer (not shown) such as a resin film may be further provided on the outer side.

  The hollow flexible tube 21 of the radio wave hose 20 can be filled with a foaming resin (not shown) such as foamed polyimide, for example. By filling the flexible tube 21 with a foamable resin, the bending resistance of the radio wave hose 20 can be further improved.

  FIG. 6 shows an application example of the shield composite 10. In this application example, the second metal layer 12 of the shield composite 10 having a four-layer structure of the first metal layer 12 / first resin layer 11 / second metal layer 12 / second resin layer 11. (In FIG. 6, the third layer from the bottom, which is the metal layer 12 positioned on the outer side in a state of being wound around the flexible tube 21), and the circuit wiring portion 13 processed by circuit wiring is provided. Is shown.

  In the application example of FIG. 6, the innermost first metal layer 12 wound around the flexible tube 21 (the first layer from the bottom in FIG. The metal layer 12) located inside in the wound state has a function of shielding electromagnetic waves transmitted through the radio wave hose 20. The second metal layer 12 having the circuit wiring portion 13 functions as a flexible circuit that transmits an electrical signal, for example. That is, by applying the shield composite 10 shown in FIG. 6 to the radio wave hose 20, high-frequency transmission is performed inside the hollow flexible tube 21, and at the same time, at the outer peripheral portion of the flexible tube 21. The circuit wiring portion 13 formed on the second metal layer 12 can transmit an electric signal. In this case, the second resin layer 11 (the fourth layer from the bottom in FIG. 6, and the resin layer 11 positioned outside in the state of being wound around the flexible tube 21) It functions as a 13 coverlay film.

  Note that the shield composite 10 having the three-layer structure of the first metal layer 12 / resin layer 11 / second metal layer 12 as shown in FIG. A circuit wiring portion 13 obtained by processing circuit wiring can be provided on the metal layer 12 positioned. In this case, a separate protective layer may be provided outside the metal layer 12 having the circuit wiring portion 13.

<Coaxial cable>
FIG. 7 is an explanatory view showing a coaxial cable 30 as a high-frequency transmission member in which the shield composite 10 is applied as a shield member. The coaxial cable 30 includes an inner conductor 31, an insulating resin portion 32 that covers the inner conductor 31, a shield composite 10 that is wound around the insulating resin portion 32 from the outside, and a coating resin that covers the outside of the shield composite 10. Part 33. Here, at least one metal layer 12 located on the innermost peripheral side of the shielding composite 10 has a high-frequency shielding function as an external conductor. In addition, a mesh metal layer (not shown) may be further provided between the shielding composite 10 and the coating resin portion 33.

  In the coaxial cable 30, the method for attaching the shielding composite 10 is the same as that for the radio wave hose 20. The tape-shaped shield composite 10 is spirally wound around the insulating resin portion 32 so as to be partially overlapped inside and outside. In this way, by winding the shielding composite 10 in a spiral shape so that the overlapping region is partially formed, the bending resistance when the coaxial cable 30 is bent is improved, and the shielding performance is improved. Can be secured. Further, since the shielding composite 10 has a structure in which the resin layer 11 and the metal layer 12 are laminated in advance and integrated, it is difficult to cause peeling between them and has excellent bending resistance. .

  In the coaxial cable 30 according to the present embodiment, the shielding composite 10 may have, for example, a two-layer structure of the resin layer 11 / metal layer 12 shown in FIG. 2, and the first metal layer 12 / shown in FIG. A three-layer structure of resin layer 11 / second metal layer 12 or a three-layer structure of first resin layer 11 / metal layer 12 / second resin layer 11 shown in FIG. In the case of the two-layer laminated structure shown in FIG. 2, the metal layer 12 may be wound inside, or the resin layer 11 may be wound inside.

  In the coaxial cable 30 of the present embodiment, when the shield composite 10 having the three-layer structure of the first metal layer 12 / resin layer 11 / second metal layer 12 shown in FIG. 3 is used, the second metal The layer 12 can be subjected to circuit wiring processing. Further, as the shielding composite 10, four layers of the first metal layer 12 / first resin layer 11 / second metal layer 12 / circuit layer 13 shown in FIG. What has a structure can also be used. In these cases, high-frequency transmission is performed through the inner conductor 31, and an electric signal can be transmitted by the circuit formed in the second metal layer 12 in the outer peripheral portion of the insulating resin portion 32. Become.

[Second Embodiment]
Next, referring to FIG. 8, a shield composite 10A according to a second embodiment of the present invention will be described. FIG. 8 is a perspective view showing the appearance of the shield composite 10A in a wound state. The shield composite 10A has a long tape shape and has a structure in which a resin layer 11 and a metal layer 12 which are resin films are laminated. The shield composite 10A has a strip-shaped stacked region in which the metal layer 12 is stacked and a strip-shaped non-stacked region in which the metal layer 12 is not stacked in a short direction perpendicular to the longitudinal direction. Yes. In FIG. 8, the central portion in the width direction of the tape-shaped shield composite 10 </ b> A is a laminated portion 41 (laminated region) in which the resin layer 11 and the metal layer 12 are laminated, and both sides of the laminated portion 41 (in the width direction). In the vicinity of the end portion), only the resin layer 11 on which the metal layer 12 is not laminated is a non-laminated portion 42 (non-laminated region).

  The laminated portion 41 can have the same configuration as that of the first embodiment. As illustrated in FIG. 2, the resin layer 11 and the metal layer 12 are formed on one side of the resin layer 11. A two-layer structure may be used, and as illustrated in FIG. 3, a resin layer 11 and a three-layer structure in which metal layers 12 are formed on both sides of the resin layer 11 may be used. As illustrated in FIG. A three-layer structure in which the layer 12 and the resin layer 11 are formed on both sides of the metal layer 12 may be used. The laminated portion 41 is not limited to two or three layers, and may have a structure in which four or more layers are laminated.

  In the shield composite 10A shown in FIG. 8, the non-laminated portion 42, the laminated portion 41, and the non-laminated portion 42 are formed in a strip shape in an area ratio of 1: 1: 1, for example, in the width direction.

  The non-laminated portion 42 is composed only of the resin layer 11. In the shield composite 10A, the non-laminated portion 42 functions as a protective film or a covering film that covers the laminated portion 41 in a state of being spirally wound around the transmission member. FIG. 9 is an explanatory diagram showing a state in which the shield composite 10A is applied to the radio wave hose 20 as a high-frequency transmission member. The radio wave hose 20 includes a hollow flexible tube 21 and a shielding complex 10A wound around the flexible tube 21 spirally from the outside. The metal layer 12 (the innermost metal layer 12 in the case of having a plurality of metal layers 12) of the shield composite 10A propagates through the internal space of the flexible tube 21 (for example, millimeter wave, micro wave). Shield waves).

  As shown in FIG. 9, the tape-shaped shield composite 10 </ b> A is spirally formed on the flexible tube 21 so that the non-laminated portion 42 is superimposed on the laminated portion 41 wound one turn forward from the outside. Wrapped. In other words, the long shield composite 10A has a longitudinal direction that is not perpendicular to the major axis direction of the flexible tube 21, but has a predetermined angle, and the non-laminated portion 42 on one side. The outer periphery of the flexible tube 21 is wrapped around the outer periphery of the flexible tube 21 while shifting the position in the major axis direction of the flexible tube 21 in the width direction so as to overlap each other inward and outward. Thus, by winding the shield composite 10A in a spiral shape, the bending resistance when the radio wave hose 20 is folded is improved, and the shielding performance can be ensured even in the folded state. Since the shield composite 10 has a structure in which the resin layer 11 and the metal layer 12 are laminated and integrated in advance, peeling hardly occurs between them and has excellent bending resistance.

  The area where the shielding composite 10A is partially overlapped when wound around the flexible tube 21 is, for example, 1/5 in the width direction in consideration of the width of the non-laminated portion 42 and the width of the laminated portion 41. From within the range of 4/5, preferably within the range of 2/5 to 3/5, it can be set as appropriate according to the outer diameter of the flexible tube 21, the state of use of the radio wave hose 20, the application, and the like.

  When the laminated portion 41 has a two-layer laminated structure (see FIG. 2), the metal layer 12 may be wound inside, or the resin layer 11 may be wound inside. Even when the resin layer 11 is on the inner side, the metal layer 12 is covered with the non-laminated portion 42 that is wound one turn later, so that it has excellent flexibility and there is no need to provide a protective layer such as a resin film on the outer side. That is, even if the shielding composite 10A has a two-layer structure, excellent shielding properties and bending resistance can be obtained and sufficient durability against the external environment can be obtained.

  Even when the laminated portion 41 of the shielding composite 10A has a three-layer structure of the first metal layer 12 / resin layer 11 / second metal layer 12 as shown in FIG. Since the metal layer 12 positioned outside in the wound state is covered by the non-laminated portion 42 that is wound once, there is no need to further provide a protective layer such as a resin film on the outside thereof. In particular, even when the laminated portion 41 of the shield composite 10A has a three-layer structure and the circuit wiring portion 13 processed by circuit wiring is provided on the metal layer 12 positioned outside in a state of being wound around the flexible tube 21, This is advantageous because it is not necessary to provide a separate protective layer.

  The laminated portion 41 and the non-laminated portion 42 in the shield composite 10A of the present embodiment are not limited to the aspect shown in FIG. For example, as shown in FIG. 10, one laminated portion 41 and one non-laminated portion 42 may be alternately formed in a strip shape in the width direction of the tape-shaped shield composite 10 </ b> A. For example, as shown in FIG. 11, two or more laminated portions 41 and two or more non-laminated portions 42 may be alternately formed in a strip shape in the width direction of the tape-shaped shield composite 10A. .

  The shield composite 10A of the present embodiment can also be applied to the coaxial cable 30 in the same manner as the shield composite 10 of the first embodiment. In this case, at least one metal layer 12 in the laminated portion 41 can function as an outer conductor of the coaxial cable 30.

  Other configurations and effects in the present embodiment are the same as those in the first embodiment.

  Next, details of the resin layer 11 and the metal layer 12 constituting the shielding composites 10 and 10A and a method for manufacturing the shielding composites 10 and 10A will be described.

<Resin layer>
In the shielding composites 10 and 10A, the resin layer 11 is preferably made of a material having flexibility and adhesiveness that can be wound around the outer periphery of the flexible tube 21 or the insulating resin portion 32, and has heat resistance. A material is more preferred. Accordingly, the resin layer 11 is not particularly limited. For example, polyimide, bismaleimide resin, polybenzoxazole, polybenzimidazole, polybenzothiazole, polyamide, polyamideimide, polyetherimide, polyetheretherketone, PET, polyphenylene ether , Liquid crystal polymer (aromatic polyester), phenoxy resin, epoxy resin, polybenzoxazine, polystyrene, polyolefin, PTFE (polytetrafluoroethylene; registered trademark Teflon, etc.) and the like. Among these, it is preferable that the resin layer 11 has a single layer or a plurality of polyimide layers. In this case, the polyimide may be a non-thermoplastic polyimide or a thermoplastic polyimide. In order to improve the adhesiveness between the resin layer 11 and the metal layer 12, the layer in contact with the metal layer 12 in the resin layer 11 is preferably a thermoplastic polyimide layer. For example, when the non-thermoplastic polyimide layer is P1, the thermoplastic polyimide layer is P2, and the metal layer 12 is M1, when the resin layer 11 is two layers, the layers may be laminated in the order of P1 / P2 / M1. preferable. Moreover, when the resin layer 11 is made into three layers, it is preferable to laminate | stack in order of P2 / P1 / P2 / M1 or the order of P1 / P1 / P2 / M1. The polyimide that can be preferably used as the material of the resin layer 11 will be described in detail later.

(Thickness of resin layer 11)
In the shield composites 10 and 10A, the thickness of the resin layer 11 is preferably in the range of, for example, 5 μm to 70 μm, and more preferably in the range of 10 μm to 50 μm. In addition, the thickness of the resin layer 11 is desirably equal to or greater than the thickness of the metal foil 12 from the viewpoint of filling properties of the resin into the formed circuit. On the other hand, if the thickness of the resin layer 11 exceeds 70 μm, there may be a problem in the flexibility and flexibility of the shielding composites 10 and 10A. In addition, what is necessary is just to make it the total thickness in the said range, when forming the resin layer 11 from multiple layers.

The shield composites 10 and 10 </ b> A may contain an inorganic filler in the resin layer 11 as necessary. Specific examples of the inorganic filler include, for example, silicon dioxide, aluminum oxide, magnesium oxide, beryllium oxide, boron nitride, aluminum nitride, silicon nitride, aluminum fluoride, calcium fluoride, calcium carbonate, talc and the like. These may be used alone or in combination of two or more.

(Glass transition temperature) Moreover, the composites 10 and 10A for a shield are the objectives, such as ensuring the adhesiveness, when winding around the outer periphery of the flexible tube 21, the insulating resin part 32, etc., and low temperature processing as a circuit protective film, for example. From the viewpoint of property, the glass transition temperature (Tg) of the resin layer 11 is preferably 180 ° C. or lower.

<Polyimide>
Next, polyimide that is preferably used as the material of the resin layer 11 will be described. In order to impart excellent high-frequency shielding characteristics to the shielding composites 10 and 10A, when the material of the resin layer 11 is polyimide, at least one of the polyimide layers is an acid anhydride containing an aromatic tetracarboxylic acid anhydride. It is preferably formed using a polyimide obtained by reacting a component with a diamine component containing diaminosiloxane or aliphatic diamine and aromatic diamine, and having excellent adhesion at low temperatures.

  As an example of a preferable polyimide, polyimidesiloxane containing structural units represented by the following general formulas (1) and (2) is preferable.

［式中、Ａｒは芳香族テトラカルボン酸無水物から誘導される４価の芳香族基、Ｒ_１はジアミノシロキサンから誘導される２価のジアミノシロキサン残基、Ｒ_２は芳香族ジアミンから誘導される２価の芳香族ジアミン残基をそれぞれ表し、ｍ、ｎは各構成単位の存在モル比を示し、ｍは０．５〜１．０の範囲内、好ましくは０．７〜１．０の範囲内、ｎは０〜０．５の範囲内、好ましくは０〜０．３の範囲内である］

[Wherein Ar is a tetravalent aromatic group derived from an aromatic tetracarboxylic acid anhydride, R ₁ is a divalent diaminosiloxane residue derived from diaminosiloxane, and R ₂ is derived from an aromatic diamine. Each of the divalent aromatic diamine residues, m and n represent the molar ratio of each constituent unit, and m is in the range of 0.5 to 1.0, preferably 0.7 to 1.0. Within the range, n is in the range of 0 to 0.5, preferably in the range of 0 to 0.3]

Moreover, as another example of a preferable polyimide, it is obtained by reacting an acid anhydride component containing an aromatic tetracarboxylic acid anhydride and a diamine component containing an aliphatic diamine and an aromatic diamine. It is preferable to be formed using a polyimide excellent in. As such a polyimide, for example, in the structural units represented by the above general formulas (1) and (2), the group R ₁ is “a divalent diaminosiloxane residue derived from diaminosiloxane”. Instead, a polyimide which is “a divalent residue derived from an aliphatic diamine” is preferable.

In the above general formula (1), the polyimidesiloxane is preferably synthesized from a diaminosiloxane represented by the following general formula (3) as the raw material R ₁ . In this case, it is preferable that the molar ratio of the diaminosiloxane of the general formula (3) in the total diamine component of the raw material is 80 mol% or more.

［式中、Ｒ_３及びＲ_４は、それぞれ、酸素原子を含有していてもよい２価の有機基を示し、Ｒ_５〜Ｒ_８は、それぞれ炭素数１〜６の炭化水素基を示し、平均繰り返し数であるｍ_１は、１〜２０である］

[Wherein, R ₃ and R ₄ each represent a divalent organic group that may contain an oxygen atom, R _{5 to} R ₈ each represent a hydrocarbon group having 1 to 6 carbon atoms, M ₁ that is the average number of repetitions is ₁ to 20]

  Examples of the group Ar include those represented by the following formula (4) or formula (5).

［式（５）中、Ｗは単結合、炭素数１〜１５の２価の炭化水素基、−Ｏ−、−Ｓ−、−ＣＯ−、−ＳＯ_２−、−ＮＨ−若しくは−ＣＯＮＨ−から選ばれる２価の基を示す］

[In the formula (5), W represents a single bond, a divalent hydrocarbon group having 1 to 15 carbon atoms, —O—, —S—, —CO—, —SO ₂ —, —NH— or —CONH—. Indicates a divalent group selected]

As the group R _2, for example, may include those represented by the following formula (6) to (8).

［式（６）〜式（８）において、Ｒ_９は独立に炭素数１〜６の１価の炭化水素基又はアルコキシ基を示し、Ｚは単結合、炭素数１〜１５の２価の炭化水素基、−Ｏ−、−Ｓ−、−ＣＯ−、−ＳＯ_２−、−ＮＨ−若しくは−ＣＯＮＨ−から選ばれる２価の基を示し、ｎ_１は独立に０〜４の整数を示す］

[In Formula (6)-Formula (8), R < ₉ > shows a C1-C6 monovalent hydrocarbon group or an alkoxy group independently, Z is a single bond and C1-C15 bivalent carbonization. A hydrogen group, —O—, —S—, —CO—, —SO ₂ —, —NH— or —CONH— represents a divalent group, and n ₁ independently represents an integer of 0 to 4]

  Examples of the aromatic tetracarboxylic acid anhydride suitably used for the preparation of a polyimide precursor such as polyimidesiloxane include 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA), 3, 3 ', 4,4'-benzophenone tetracarboxylic dianhydride (BTDA), 3,3', 4,4'-diphenylsulfone tetracarboxylic dianhydride (DSDA), pyromellitic dianhydride (PMDA) Etc. Among them, particularly preferred acid anhydrides include 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA), 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride ( BTDA), 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride (DSDA) and the like. These aromatic tetracarboxylic acid anhydrides can be blended in combination of two or more.

  Moreover, as an aromatic diamine used suitably for preparation of the precursor of polyimides, such as a polyimide siloxane, 2, 2-bis (4-amino phenoxyphenyl) propane (BAPP), 2,2'- divinyl-4 is mentioned, for example. , 4′-diaminobiphenyl (VAB), 2,2′-dimethyl-4,4′-diaminobiphenyl (m-TB), 2,2′-diethyl-4,4′-diaminobiphenyl, 2,2 ′, Examples include 6,6′-tetramethyl-4,4′-diaminobiphenyl, 2,2′-diphenyl-4,4′-diaminobiphenyl, 9,9-bis (4-aminophenyl) fluorene, and the like. Among them, particularly preferred diamine components are 2,2-bis (4-aminophenoxyphenyl) propane (BAPP), 2,2′-divinyl-4,4′-diaminobiphenyl (VAB), 2,2′- Examples thereof include dimethyl-4,4′-diaminobiphenyl (m-TB). These aromatic diamines can be blended in combination of two or more.

(Diaminosiloxane)
In the preparation of the polyimidesiloxane precursor, examples of the diaminosiloxane used as one of the raw materials include the diaminosiloxane represented by the above general formula (3). As specific examples of the diaminosiloxane represented by the general formula (3), diaminosiloxanes represented by the following formulas (9) to (13) are preferable, and among these, the diaminosiloxane represented by the formula (9) Is more preferable. These diaminosiloxanes can be blended in combination of two or more. In the equation (3), Equation (9) to Formula (13), _{m 1} is an average repeating number is in the range of 1-20, preferably 5-15. When m ₁ is smaller than 1, the glass transition temperature becomes high, and the low temperature workability is remarkably deteriorated, and when it exceeds 20, the adhesive strength is lowered.

(Aliphatic diamine)
In the above general formula (1), when group R ₁ is a divalent diamine residue derived from an aliphatic diamine as the raw material for forming the group R _1, fats having a cyclic structure in the molecule Preferred are aliphatic diamines, aliphatic diamines having a carbon number in the range of 24 to 48, or aliphatic diamines derived from dimer acid, more preferably fats derived from the dimer acid in the range of carbon atoms 24 to 48. Group diamines are preferred. Here, the cyclic structure means an aliphatic cyclic structure other than the aromatic ring, and may have an unsaturated bond in the ring. Further, when the aliphatic diamine has less than 24 carbon atoms, the solubility may be lowered and handling may be difficult.

The aliphatic diamine derived from the dimer acid preferably used as a raw material for forming a divalent diamine residue derived from the aliphatic diamine of the group R ₁ is obtained by converting the carboxyl group of the dimer acid into a hydroxyl group. Later, it is an aliphatic diamine converted to an amino group. That is, an aliphatic diamine derived from dimer acid can be obtained by polymerizing an unsaturated fatty acid such as oleic acid or linoleic acid to form dimer acid, reducing it, and then aminating. As such an aliphatic diamine, for example, a commercial product such as DDA (aliphatic diamine having 36 carbon atoms, manufactured by Croda Japan Co., Ltd., trade name: PRIAMINE 1074) can be used.

  Each of the acid anhydride and diamine may be used alone or in combination of two or more. In addition, acid anhydrides and diamines other than those described above can be used in combination.

  A polyimide such as polyimidesiloxane having the structural units represented by the general formulas (1) and (2) is prepared by reacting the aromatic tetracarboxylic acid anhydride, diaminosiloxane or aliphatic diamine and aromatic diamine in a solvent, After producing the body resin, it can be produced by heating and ring closure. For example, an acid anhydride component and a diamine component are dissolved in an organic solvent in an approximately equimolar amount, and are stirred for 30 minutes to 24 hours at a temperature within a range of 0 to 100 ° C. to cause a polymerization reaction, thereby causing a polyimide reaction such as polyimidesiloxane. The precursor polyamic acid is obtained. In the reaction, the reaction components are dissolved so that the precursor to be produced is in the range of 5 to 30% by weight, preferably in the range of 10 to 20% by weight in the organic solvent. Examples of the organic solvent used in the polymerization reaction include N, N-dimethylformamide, N, N-dimethylacetamide (DMAC), N-methyl-2-pyrrolidone, 2-butanone, dimethyl sulfoxide, dimethyl sulfate, cyclohexanone, dioxane, Tetrahydrofuran, diglyme, triglyme and the like can be mentioned. Two or more of these solvents can be used in combination, and further, aromatic hydrocarbons such as xylene and toluene can be used in combination.

  The synthesized precursor is usually advantageously used as a reaction solvent solution, but can be concentrated, diluted, or replaced with another organic solvent if necessary. Moreover, since a precursor is generally excellent in solvent solubility, it is advantageously used. The method for imidizing the precursor is not particularly limited, and for example, heat treatment in which heating is performed in the solvent at a temperature condition in the range of 80 to 400 ° C. for 0.5 to 24 hours is suitably employed.

  When the precursor is prepared, the mixing ratio of the acid anhydride component and the diamine component as raw materials is not particularly limited. For example, the molar ratio of the mixing of the acid anhydride component and the diamine component is a metal foil. From the viewpoint of adhesiveness to 1.00: 1.001 to 1.0: 1.2 is preferable.

Moreover, polyimides, such as a polyimide siloxane which has a structural unit represented by the said Formula (1) and (2), are obtained by reaction with aromatic tetracarboxylic anhydride, diaminosiloxane, aliphatic diamine, and aromatic diamine. It has an imide structure. In order to maintain the adhesive force with the metal layer 12, a completely imidized structure is most preferable. The imidation ratio was measured at about 1015 cm ⁻¹ by measuring the infrared absorption spectrum of the polyimide thin film by a single reflection ATR method using a Fourier transform infrared spectrophotometer (commercial product: FT / IR620 manufactured by JASCO Corporation). Based on the absorbance of C═O stretching derived from an imide group of 1780 cm ⁻¹ , based on the benzene ring absorber.

<Metal layer>
The material of the metal layer 12 in the shield composites 10 and 10A according to the present embodiment is not particularly limited. For example, copper, stainless steel, iron, nickel, beryllium, aluminum, zinc, indium, silver, gold, tin , Zirconium, tantalum, titanium, lead, magnesium, manganese, and alloys thereof. Among these, copper or a copper alloy is particularly preferable.

(Metal layer thickness)
In the shield composites 10 and 10A of the present embodiment, the thickness of the metal layer 12 is preferably in the range of 5 μm to 20 μm, and more preferably in the range of 8 μm to 15 μm. If the thickness of the metal layer 12 is less than 5 μm, the rigidity of the metal layer 12 itself is reduced in the process of forming the resin layer 11 on the metal layer 12, for example, during the production of the shielding composite 10, 10A. In some cases, wrinkles or the like may occur on the shield composite 10 or 10A. Further, if the thickness of the metal layer 12 exceeds 20 μm, the shielding property decreases due to an increase in bending stress applied to the metal layer 12 when the shielding composite 10, 10A (or high-frequency transmission member) is bent, The bending resistance of the high-frequency transmission member may be reduced.

  The metal layer 12 of this Embodiment will not be specifically limited if the said characteristic is satisfied, Metal foils, such as commercially available copper foil, can be used. When a copper foil is used as the metal layer 12, a rolled copper foil or an electrolytic copper foil may be used. For example, examples of rolled copper foil include BHY-22B-T (trade name) and GHY5-93F-T (trade name) manufactured by JX Nippon Mining & Metals Co., Ltd., and examples of electrolytic copper foil include Furukawa Electric. F1-WS (trade name) manufactured by Kogyo Co., Ltd., F2-WS (trade name), HLS (trade name), HLS-Type 2 (trade name), HLB (trade name), AMFN (trade name) manufactured by JX Nippon Mining & Metals Co., Ltd., TQ-M4-VSP (trade name) manufactured by Mitsui Mining & Smelting Co., Ltd., T49A-DS-HD2 (trade name) manufactured by Fukuda Metal Foil Powder Co., Ltd. Etc.

[Manufacturing Method of Shield Composite] The manufacturing method of the shield composite 10, 10A is not particularly limited, but a polyimide solution (or a polyamic acid solution) is exemplified when polyimide is used as the material of the resin layer 11. A method of forming a polyimide layer (or a polyamic acid layer) on the metal foil or the substrate by applying heat treatment (drying and curing) after coating the metal foil on the metal foil or an arbitrary substrate to be the metal layer 12 is preferable. In addition, when using things other than metal foil as a base material, after heat processing, it peels and it makes a polyimide film, What is necessary is just to laminate this polyimide film with the metal foil which prepared separately.

  About the preferable manufacturing method of the composite body 10 for shielding, when the material of the resin layer 11 is a polyimide and the material of the metal layer 12 is copper as an example, it includes the following steps (1) to (3). Can do.

Step (1):
Step (1) is a step of obtaining a polyamic acid resin solution which is a polyimide precursor. As described above, this step can be performed by reacting the raw material diamine component and acid anhydride component in an appropriate solvent.

Step (2):
Step (2) is a step of applying a polyamic acid resin solution on the copper foil to form a coating film. The copper foil can be used in the form of a cut sheet, a roll, or an endless belt. In order to obtain productivity, it is efficient to use a roll-like or endless belt-like form so that continuous production is possible. The method of forming a coating film can be formed by applying a resin solution of polyamic acid directly on a copper foil or by applying the resin solution on a polyimide layer supported by the copper foil and then drying. The method of applying is not particularly limited, and it is possible to apply with a coater such as a comma, die, knife, lip or the like.

  The polyimide layer may be a single layer or a plurality of layers. In the case where a plurality of polyimide layers are used, other precursors can be sequentially applied on the precursor layers made of different components. When the precursor layer is composed of three or more layers, the precursor having the same configuration may be used twice or more. A two-layer or a single layer having a simple layer structure is preferable because it can be advantageously obtained industrially. The thickness of the precursor layer (after drying) is, for example, in the range of 3 to 100 μm, preferably in the range of 3 to 50 μm. It is also possible to once imidize a single layer or a plurality of precursor layers into a single layer or a plurality of polyimide layers, and further form a precursor layer thereon.

  Moreover, when making a polyimide layer into multiple layers, it is preferable to form the layer of a precursor so that the polyimide layer which touches a copper foil layer may become a thermoplastic polyimide layer. By using thermoplastic polyimide, the adhesiveness with the copper foil layer can be improved. Such a thermoplastic polyimide preferably has a glass transition temperature (Tg) of 360 ° C. or lower, more preferably 40 to 320 ° C.

  In addition, when preparing the composite body 10 for a shield which has the 3 layer structure of the resin layer 11 (polyimide layer) / metal layer 12 (copper foil layer) / resin layer 11 (polyimide layer) illustrated in FIG. A coating film can be formed on the other surface of the copper foil not formed in the same manner as in the step (2).

Step (3):
Step (3) is a step of forming the resin layer 11 by heat-treating the coating film to imidize. The imidization method is not particularly limited, and for example, heat treatment such as heating for 1 to 24 hours under a temperature condition in the range of 80 to 400 ° C. is suitably employed. In order to suppress oxidation of the copper foil layer, heat treatment in a low oxygen atmosphere is preferable. Specifically, the heat treatment is preferably performed in an inert gas atmosphere such as nitrogen or a rare gas, in a reducing gas atmosphere such as hydrogen, or in a vacuum. By heat treatment, the polyamic acid in the coating film is imidized, and a polyimide layer in a state of being laminated on the copper foil layer is formed.

  In addition to the steps (1) to (3), an optional step (4) can include an etching step.

Process (4)
By etching the copper foil (metal layer 12) of the shielding composite 10 obtained in the above steps (1) to (3), the laminated portion 41 and the non-laminated portion 42 are formed in a predetermined pattern. The shield composite body 10A (FIGS. 8, 10, and 11) of the embodiment can be obtained. Etching of the copper foil can be performed by, for example, patterning a predetermined circuit by exposure and development using a photosensitive dry film, masking, and treating with an acid.

  Moreover, in addition to the said process (1)-(3), a lamination process can be further included as arbitrary processes (5).

Step (5)
As illustrated in FIG. 2, the shield composite 10 having a two-layer structure in which the polyimide layer as the resin layer 11 and the copper foil layer as the metal layer 12 are laminated by the above steps (1) to (3). After the preparation, a separately prepared copper foil is thermocompression bonded to the polyimide layer side, for example, metal layer 12 (copper foil layer) / resin layer 11 (polyimide layer) / metal layer 12 (copper layer) illustrated in FIG. The shield composite 10 having a three-layer structure of (foil layer) can be obtained. Further, by separately thermocompression bonding a separately prepared polyimide film to the copper foil layer side of the shield composite 10 having a two-layer structure as shown in FIG. 2, for example, the resin layer 11 (polyimide layer) / A shield composite 10 having a three-layer structure of metal layer 12 (copper foil layer) / resin layer 11 (polyimide layer) can be obtained. Further, for example, two shield composites 10 having a two-layer structure as shown in FIG. 2 are prepared, and the metal layer of the other shield composite 10 is formed on the resin layer 11 (polyimide layer) of one shield composite 10. By performing thermocompression bonding so that 12 (copper foil layers) face each other, the shield composite 10 having a four-layer structure can be obtained. Thus, by laminating the shield composite 10 obtained in the above steps (1) to (3) with the resin film, the metal foil, or the shield composite 10 produced separately, the multilayer composite shield is provided. The composite 10 can be prepared.

  As described above, the shield composites 10 and 10A having the polyimide layer as the resin layer 11 and the copper foil layer as the metal layer 12 can be manufactured.

  The shielding composites 10 and 10A have a simple structure including a resin layer 11 and a metal layer 12 integrated with the resin layer 11, and can be easily attached to a high-frequency transmission line. In addition, since the shielding composites 10 and 10A can easily adjust the thickness of the resin layer 11 and / or the metal layer 12 and ensure the uniformity of these thicknesses, matching of the characteristic impedance is easy. The shielding composites 10 and 10A can give excellent shielding properties and bending resistance to the high-frequency transmission member. Therefore, the radio frequency hose 10 having the shielding composites 10 and 10A, the high-frequency transmission member such as the coaxial cable 30 has excellent shielding properties and bending resistance.

  As mentioned above, although embodiment of this invention was described in detail for the purpose of illustration, this invention is not restrict | limited to the said embodiment.

  The shielding composites 10 and 10A are not limited to the laminated structure of the resin layer 11 and the metal layer 12, but instead of the metal layer 12, for example, carbon fiber, carbon nanotube, carbon nanohorn, carbon nanowire, graphene, graphite, etc. The carbon material layer may be laminated on the resin layer 11, or the carbon material may be mixed in the resin layer 11 to form a composite structure.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. In the following examples, various measurements and evaluations are as follows unless otherwise specified.

[Measurement of glass transition temperature (Tg)]
The glass transition temperature was measured using a thermomechanical analyzer (manufactured by Bruker, 4000SA) on a test piece having a width of 2 mm and a length of 30 mm at a distance between chucks of 15 mm, a load of 2 g, and a heating rate of 5 ° C./min. The amount of linear expansion in the length direction of the test piece is measured, and the inflection point is defined as Tg.

The abbreviations used in the examples represent the following compounds.
BTDA: 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride DSDA: 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride BPDA: 3,3 ′, 4,4 ′ -Diphenyltetracarboxylic dianhydride BAPP: 2,2-bis (4-aminophenoxyphenyl) propane HAB: 4,4 '-(3,3'-dihydroxy) diaminobiphenyl PSX-A: represented by the chemical formula (9) The weight average molecular weight of diaminosiloxane is 740
DDA: Aliphatic diamine having 36 carbon atoms (manufactured by Croda Japan Co., Ltd., trade name: PRIAMINE 1074, amine value: 205 mg KOH / g, a mixture of cyclic and chain structure dimer diamine, content of dimer component: 95% by weight or more )

Synthesis example 1
A 1000 ml separable flask was charged with 38.81 g BTDA (0.1205 mol), 168 g N-methyl-2-pyrrolidone and 112 g xylene and mixed well at room temperature. Next, 71.30 g of PSX-A (0.09635 mol) was added dropwise using a dropping funnel, the reaction solution was ice-cooled with stirring, and 9.89 g of BAPP (0.0241 mol) was added. The mixture was stirred at room temperature for 2 hours to obtain a polyamic acid solution. This polyamic acid solution was heated to 190 ° C., heated and stirred for 20 hours to obtain a polyimide solution a having completed imidization. The weight average molecular weight of the polyimide solution a is 95,000.

Synthesis example 2
A 1000 ml separable flask was charged with 50.16 g of DSDA (0.14 mol), 200 g of N-methyl-2-pyrrolidone and 200 g of xylene and mixed well at room temperature, then using a dropping funnel 31 .54 g PSX-A (0.0434 mol) was added dropwise, the reaction solution was ice-cooled with stirring, 37.36 g BAPP (0.091 mol) and 1.30 g HAB (0.006 mol). Was added and stirred at room temperature for 2 hours to obtain a polyamic acid solution. This polyamic acid solution was heated to 190 ° C. and heated and stirred for 20 hours to obtain a polyimide solution b in which imidization was completed. The weight average molecular weight of the polyimide solution b is 100,000.

Synthesis example 3
A 1000 ml separable flask was charged with 35.22 g BPDA (0.120 mol), 64.78 g DDA (0.120 mol), 140 g N-methyl-2-pyrrolidone and 93 g xylene at room temperature. Was stirred for 2 hours to obtain a polyamic acid solution. This polyamic acid solution was heated to 190 ° C., heated and stirred for 4 hours to obtain a polyimide solution c having completed imidization. The weight average molecular weight of the polyimide solution c is 60,000.

[Example 1]
The polyimide solution a synthesized in Synthesis Example 1 was applied to one side of copper foil 1 (F1-WS, length x width x thickness = 200 mm x 300 mm x 25 μm, manufactured by Furukawa Electric Co., Ltd.) and dried at 135 ° C. for 5 minutes. And a copper-polyimide resin laminate 1a was obtained. The glass transition temperature of the polyimide resin film in the copper-polyimide resin laminate 1a was 50 ° C. A dry film was laminated on the copper foil surface of the copper-polyimide resin laminate 1a, and exposure, development, and etching were performed so as to obtain the shape of FIG. 8 (metal part: 10 mm, resin part: 10 mm). Further, the dry film resist was peeled off to obtain a copper-polyimide laminate 1b having the shape shown in FIG. The copper-polyimide laminate 1b was wound around a silicone tube having an outer diameter of 10 mm and an inner diameter of 6 mm so as to have the spiral shape of FIG. 9 and heated in an oven at 160 ° C. for 1 hour to obtain the radio wave hose 1 having the shape of FIG. .

[Example 2]
A copper-polyimide resin laminate 2a was obtained in the same manner as in Example 1 except that the polyimide solution b synthesized in Synthesis Example 2 was used instead of the polyimide solution a in Example 1. The glass transition temperature of the polyimide resin film in the copper-polyimide resin laminate 2a was 160 ° C. In the same manner as in Example 1, a copper-polyimide laminate 2b was obtained, and a radio wave hose 2 was obtained.

[Example 3]
A copper-polyimide resin laminate 3a was obtained in the same manner as in Example 1 except that the polyimide solution c synthesized in Synthesis Example 3 was used instead of the polyimide solution a in Example 1. The glass transition temperature of the polyimide resin film in the copper-polyimide resin laminate 3a was 45 ° C. In the same manner as in Example 1, a copper-polyimide laminate 3b was obtained, and a radio wave hose 3 was obtained.

  DESCRIPTION OF SYMBOLS 10,10A ... Composite for shielding, 11 ... Resin layer, 12 ... Metal layer, 13 ... Circuit wiring part, 20 ... Radio wave hose, 21 ... Flexible tube, 30 ... Coaxial cable, 31 ... Inner conductor, 32 ... Insulation Resin part 33 ... Coating resin part 41 ... Laminated part 42 ... Non-laminated part

Claims (7)

A long resin film,
A conductive material integrated with the resin film;
With
A shielding complex that shields a high frequency wave from a transmission member that transmits a high frequency wave by being spirally wound from the outside so as to partially form an overlapping region.   The composite for shielding according to claim 1, wherein the conductive material is a metal layer laminated on the resin film.   3. A strip-shaped stacked portion in which the metal layers are stacked and a strip-shaped non-stacked portion in which the metal layers are not stacked are provided in a short direction perpendicular to the longitudinal direction of the resin film. The composite for shielding described in 1.   The circuit part by which circuit wiring was processed is provided in the metal layer except the innermost metal layer in the wound state among the metal layers provided with a plurality of the metal layers. Shield composite.   The shield composite according to any one of claims 1 to 4, wherein a material of the resin film is polyimide. A long and hollow flexible tube;
A high-frequency transmission member comprising the shield composite according to any one of claims 1 to 5, which is wound around an outer periphery of the flexible tube. The high frequency transmission member which has an internal conductor, the insulating resin part which covers this internal conductor, and the composite body for shielding of any one of Claim 1 to 5 wound around the outer periphery of this insulating resin part .

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