WO2021065968A1

WO2021065968A1 - Resin laminate for low-dielectric material

Info

Publication number: WO2021065968A1
Application number: PCT/JP2020/037053
Authority: WO
Inventors: 壮弘岩本
Original assignee: 出光興産株式会社
Priority date: 2019-10-04
Filing date: 2020-09-30
Publication date: 2021-04-08
Also published as: JP7281381B2; JP2021059038A; TW202120332A

Abstract

A resin laminate for low-dielectric material, having a total of at least three laminated layers, comprising, layered alternately, a resin layer (S) that includes a styrene resin (S1) having a syndiotactic structure and a resin layer (M) that includes a resin (M1) having a softening point of no more than 260° C. The outermost layers are resin layers (S).

Description

Resin laminate for low dielectric material

The present invention relates to a resin laminate for a low dielectric material and a method for producing the same.

Polystyrene resin having a syndiotactic structure (hereinafter, also referred to as SPS) has excellent performances such as mechanical strength, heat resistance, electrical characteristics, water absorption dimensional stability, and chemical resistance. Therefore, SPS is very useful as a resin used for various purposes such as electric / electronic equipment materials, in-vehicle / electrical parts, home appliances, various mechanical parts, and industrial materials.
Further, SPS is a hydrocarbon resin obtained by polymerizing a styrene monomer, has a small dielectric loss, and has an insulating property. Therefore, it is considered to be used as an electric / electronic device material in the above applications.

For example, Patent Document 1 discloses a polystyrene-based film for electrical insulation having specific values for tensile elastic modulus, hinge characteristics, film thickness, and haze for the purpose of obtaining a film that is not deteriorated by a refrigerant. There is.
Further, as an example of a laminated body using SPS, Patent Document 2 describes a resin layer containing a thermoplastic resin, a resin layer containing a syndiotactic polystyrene-based resin laminated on the resin layer, and a first layer on the resin layer. A laminate for an electronic circuit substrate having a first and second metal layers and having a specific value in peel strength between the metal layers is disclosed. Further, Patent Document 3 describes a biaxially oriented film containing a syndiotactic polystyrene-based resin as a main component and having a constant heat shrinkage rate of the film before and after heat treatment for the purpose of suppressing wrinkles in the manufacturing process of a printed circuit board. A laminate for manufacturing a flexible printed circuit board in which a soft film is laminated is disclosed.

Japanese Unexamined Patent Publication No. 2000-164038 JP 2015-2334 Japanese Unexamined Patent Publication No. 2011-088387

In recent years, with the miniaturization of electronic devices and the refinement of machines, there is a demand for miniaturization and thinning of electronic and electrical parts. Therefore, resins used for these parts, for example, electronic circuit boards, good radio wave transmitting resin plates used for housings, and the like are required to have higher toughness and excellent dielectric properties.
Further, recently, a resin used for a millimeter-wave radome, which is required to have high radio wave transmission as a cover for radar, is also required to have higher impact resistance and excellent dielectric properties than conventional resins.
Therefore, the present invention provides a resin laminate for a low dielectric material, which has a small dielectric loss and high toughness, and is suitable for electronic components, particularly a circuit board, a resin plate for a millimeter wave radome, and a resin plate for good radio wave transmission. Is an issue.

As a result of diligent studies, the present inventors have found that a laminate obtained by laminating an SPS layer and a styrene resin layer having a lower softening point at a certain level or more solves the above-mentioned problems. That is, the present invention relates to the following [1] to [15].

[1]
A total of three or more layers of a resin layer (S) containing a styrene resin (S1) having a syndiotactic structure and a resin layer (M) containing a resin (M1) having a softening point of 260 ° C. or lower are alternately laminated, and the outermost layer. Is a resin layer (S), which is a resin laminate for low dielectric materials.
[2]
The resin laminate for a low-dielectric material according to [1], wherein the resin layer (S) is made of an alignment film.
[3]
The resin laminate for a low-dielectric material according to [1] or [2], wherein the resin layer (S) is a biaxially stretched film.
[4]
The resin laminate for a low dielectric material according to any one of [1] to [3], wherein the styrene resin (S1) has a weight average molecular weight of 150,000 to 250,000.
[5]
The resin laminate for a low dielectric material according to any one of [1] to [4], wherein the resin (M1) is a styrene resin.
[6]
The resin laminate for a low dielectric material according to any one of [1] to [5], wherein the resin (M1) is a styrene-based resin containing paramethylstyrene as a copolymerization component.
[7]
The resin laminate for a low dielectric material according to any one of [1] to [6], wherein the resin (M1) has a weight average molecular weight of 150,000 to 250,000.
[8]
The resin laminate for a low dielectric material according to [6] or [7], wherein the paramethylstyrene component is 3 to 15 mol% in the copolymerization component of the resin (M1).
[9]
An electronic circuit board containing the resin laminate for a low dielectric material according to any one of [1] to [8].
[10]
An alignment film (SF) containing a styrene resin (S1) having a syndiotactic structure and a film (MF) containing a resin (M1) having a softening point of 260 ° C. or lower are alternately alternated, and the outermost layer is a film (SF). A method for producing a resin laminate for a low dielectric material, which comprises a step of laminating a total of three or more layers and pressing to integrate them.
[11]
The method for producing a resin laminate for a low-dielectric material according to [10], wherein the alignment film (SF) is a biaxially stretched film in the above step.
[12]
The method for producing a resin laminate for a low-dielectric material according to [10] or [11], which is pressed and integrated at 250 to 268 ° C. in the above step.
[13]
The method for producing a resin laminate for a low dielectric material according to any one of [10] to [12], which is pressed and integrated by a vacuum press method in the above step.
[14]
The method for producing a resin laminate for a low dielectric material according to [13], wherein the press pressure of the vacuum press method is 0.5 to 5.0 MPa, and the press holding time is 1 to 60 minutes.
[15]
An electronic circuit board containing a resin laminate for a low-dielectric material obtained by the production method according to any one of [10] to [14].

According to the present invention, an electronic component having a small dielectric loss and high toughness, particularly a resin laminate for a low dielectric material suitable for a circuit board, a resin plate for a millimeter wave radome, a resin plate for good radio wave transmission, and a method for producing the same. Can be provided.

It is explanatory drawing which shows one Embodiment of the resin laminate for a low dielectric material of this invention.

The resin laminate for a low dielectric material of the present invention has a resin layer (S) containing a styrene resin (S1) having a syndiotactic structure and a resin layer (M1) containing a resin (M1) having a softening point of 260 ° C. or lower. Are alternately laminated in a total of three or more layers, and the outermost layer is a resin layer (S).
Hereinafter, each item will be described in detail.

[Resin laminate for low dielectric material]
The resin laminate for a low dielectric material of the present invention has a resin layer (S) containing a styrene resin (S1) having a syndiotactic structure and a resin layer (M1) containing a resin (M1) having a softening point of 260 ° C. or lower. Are alternately laminated in a total of three or more layers, and the outermost layer is a resin layer (S).
The case of three layers which is one embodiment of the present invention is shown in FIG. The resin laminate 1 for a low dielectric material of the present invention is a styrene-based resin having a syndiotactic structure on both sides of a resin layer 2 (corresponding to a resin layer (M)) containing a resin (M1) having a softening point of 260 ° C. or lower. It is sandwiched between resin layers 3 (corresponding to resin layer (S)) containing resin (S1), and the outermost layers are all resin layers 3.

In the laminated body of the present invention, the resin layers are alternately laminated, and the outermost layer is the resin layer (S). That is, in the case of 3 layers, it is S / M / S, in the case of 5 layers, it is S / M / S / M / S, and in the case of 7 layers, it is S / M / S / M / S / M / S.
The number of layers is 3 or more, preferably 5 or more, more preferably 7 or more, further preferably 9 or more, even more preferably 15 or more, and even more preferably 22 or more. The upper limit is preferably 39 layers or less, more preferably 35 layers or less, and even more preferably 29 layers or less. By setting the number of layers to 3 or more, when an impact force is applied to the laminated body, the relatively flexible resin layer at the low softening point existing between the SPS layers disperses and relaxes the impact force and enhances toughness. It is thought that it is.

<Resin layer (S)>
The resin layer (S) contains a styrene resin (S1) having a syndiotactic structure.
In the resin layer (S), the styrene resin (S1) having a syndiotactic structure is preferably 30% by mass or more, more preferably 50% by mass or more, further preferably 80% by mass or more, and more preferably 90% by mass or more. More preferably, 95% by mass or more is further preferable, 99% by mass or more is further preferable, and 100% by mass is further preferable.

(Styrene-based resin having a syndiotactic structure (S1))
The styrene resin (S1) having a syndiotactic structure constituting the resin layer (S) is 75 mol% or more, preferably 85 mol% or more, and 30 mol of racemic pentad (rrrr). It has a syndiotacticity of% or more, preferably 50 mol% or more.
Tacticity means the ratio of phenyl rings in adjacent styrene units to which the phenyl rings are arranged alternately with respect to the plane formed by the main chain of the polymer block. Syndiotacticity can be quantified by nuclear magnetic resonance spectroscopy ( ¹³ C-NMR method). Diad indicates syndiotacticity with two consecutive monomer units, and pentad indicates syndiotacticity with five monomer units.

Examples of the styrene resin (S1) include polystyrene or a copolymer containing styrene as a main component, and polystyrene (styrene homopolymer) is preferable.
When a copolymer containing styrene as a main component is used for the styrene resin (S1), the styrene component is preferably 90 mol% or more, more preferably 95 mol% or more, further preferably 99 mol% or more, and 100 mol%. Even more preferable.

The weight average molecular weight of the styrene resin (S1) is preferably 100,000 to 300,000, more preferably 150,000 to 250,000, and even more preferably 200,000 to 250,000. The weight average molecular weight is determined by gel permeation chromatography using monodisperse polystyrene as a standard substance. Specifically, it is obtained by the measurement method described in the examples.
The softening point of the styrene resin (S1) is preferably larger than 260 ° C., more preferably 261 ° C. or higher, further preferably 262 ° C. or higher, still more preferably 263 to 267 ° C. The softening point can be measured according to JIS K7206: 2016, and specifically, it can be measured by the method shown in the examples.
The melting point of the styrene resin (S1) is preferably 265 ° C. or higher, more preferably 267 ° C. or higher, and even more preferably 269 ° C. or higher. Further, 275 ° C. or lower is preferable, and 273 ° C. or lower is more preferable.
The dielectric loss tangent (tan δ) of the resin (S1) is preferably 0.00030 or less, more preferably 0.00025 or less. The dielectric loss tangent (tan δ) can be obtained by the same measurement method as the method for measuring the dielectric loss tangent of the resin laminate described in Examples. The smaller the value of the dielectric loss tangent (tan δ), the smaller the dielectric loss and the better the dielectric characteristics. Since the resin laminate of the present invention is laminated with an SPS film having excellent insulating properties, it has a low dielectric loss tangent (tan δ), and is particularly an electronic material such as a circuit board, a resin plate for a millimeter wave radome, and a good radio wave transmitting resin plate. It is considered that a laminate suitable for the above can be obtained.

(Characteristics of resin layer (S), etc.)
The thickness of the resin layer (S) is preferably 2 to 100 μm. Among them, when used for a circuit board application, 10 to 80 μm is preferable, 15 to 60 μm is more preferable, and 20 to 50 μm is further preferable. When the thickness of the resin layer (S) is within the above range, it can be sufficiently oriented, especially during film molding, and excellent toughness can be obtained when it is formed into a laminated body.
The resin layer (S) is preferably made of an alignment film. In the present specification, the alignment film means that the alignment coefficient calculated by wide-angle X-ray diffraction (WAXD) in the crystal portion in the film plane is -0.1000 or more and 0.0100 or less in the Throw direction and -0.5000 in the Edge direction. It is more than -0.1000 and more than -0.5000 and less than -0.1000 in the End direction. The End direction is the X-ray incident from a direction parallel to the film longitudinal direction, the Edge direction is the X-ray incident perpendicular to this and also the thickness direction, and the Throw direction is perpendicular to the film surface. X-ray incident. When the orientation coefficient is within the above range, sufficient impact strength required for a resin laminate used for applications such as circuit boards, millimeter-wave radomes, and good radio wave transmitting resin plates can be obtained.

The orientation coefficient can be calculated as follows.
First, in wide-angle X-ray diffraction measurement, a monochromatic light of CuKα ray (wavelength = 1.5418 Å) is irradiated for 5 minutes at an output of 50 KV and 250 mA using an X-ray generator (ultraX 18HF manufactured by Rigaku Denki Co., Ltd.). A diffraction image was obtained by an imaging plate type two-dimensional detector. At this time, the distance (camera length) between the sample and the detector was adjusted to 105 mm.
The prepared alignment films were laminated in the same direction so as to have a thickness of 1 mm or more, and prepared as a measurement sample. By adjusting the orientation of the measurement sample and changing the incident direction of the X-ray, the above-mentioned diffraction images in the Throwh direction, the Edge direction, and the End direction were obtained, respectively.
In calculating the crystal orientation coefficient, a diffraction peak with a diffraction angle of 2θ = 6.7 deg assigned to the (110) plane of the α-type crystal was used from the intensity profile in the equatorial direction of the obtained diffraction image.
The crystal orientation coefficient f of the plane normal vector with respect to the orientation axis is calculated based on the equation (F1).

The cosφ in the above formula (F1) by the formula ^{(F2), <cos 2 φ} > in formula (F3), can be obtained respectively.

Here, φ is the azimuth in the X-ray diffraction measurement, θ is 1/2 of the diffraction angle 2θ in the equatorial direction, and δ is the inclination angle from the meridian on the diffraction image to the diffraction peak position.
Further, I (φ) is the diffraction intensity at the angle φ of the (110) plane.

When the resin layer (S) contains a styrene resin (S1) having a syndiotactic structure, the orientation coefficient of the resin layer (S) is -0.0500 or more and 0.0050 or less in the Throw direction and -0 in the Edge direction. .4800 or more and -0.1200 or less, preferably -0.4800 or more and -0.1200 or less in the End direction. The means for setting the orientation coefficient within the above-mentioned range can be realized by adjusting the stretching ratio, stretching temperature, and heat fixing temperature after stretching during film production.
Further, the resin layer (S) is more preferably made of a biaxially stretched film. The biaxially stretched film is preferably obtained by the method described in the method for producing a laminated body of the present invention described later. When a biaxially stretched film is used for the resin layer (S), the resin layer (S) is stretched in both the longitudinal direction (MD) and the width direction (TD), so that the resin molecules are parallel to the plane. It is oriented in the (MD, TD direction), and when it is a laminated body, it has excellent toughness when the surface is impacted.

<Resin layer (M)>
The resin layer (M) contains a resin (M1) having a softening point of 260 ° C. or lower.
In the resin layer (M), the resin (M1) having a softening point of 260 ° C. or lower is preferably 80% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, and further preferably 99% by mass or more. Preferably, 100% by mass is even more preferable.

(Resin (M1) having a softening point of 260 ° C. or lower)
The softening point of the resin (M1) is 260 ° C. or lower, preferably 255 ° C. or lower, more preferably 250 ° C. or lower, and even more preferably 240 ° C. or lower. The lower limit is not limited, but 220 ° C. or higher is preferable. The softening point can be measured by JIS K7206: 2016, and specifically, it can be measured by the method shown in Examples.

As the resin (M1), a styrene resin and a polyphenylene ether resin are preferable, and a styrene resin is more preferable.
Since the resin used for the resin (M1) is a styrene-based resin, the affinity between the resin layer (M) and the resin layer (S) is enhanced, each layer is difficult to peel off, and the toughness of the laminate of the present invention is improved. It is thought that it will be done.

The styrene-based resin used for the resin (M1) may have any three-dimensional regularity (tacticity) of syndiotactic, isotactic, and tactic, but syndiotactic and tactic are preferable, and syndiotactic is more preferable. ..
When the stereoregularity of the styrene resin used for the resin (M1) is syndiotactic, the melting point is 265 ° C. or lower, preferably 262 ° C. or lower, more preferably 259 ° C. or lower, and further preferably 256 ° C. or lower. preferable. The lower limit is not limited, but is preferably 245 ° C. or higher.

Specific examples of the styrene-based resin used for the resin (M1) include polystyrene, poly (hydrocarbon-substituted styrene), poly (styrene halide), poly (alkyl styrene halide), poly (alkoxystyrene), and poly (vinyl). (Salute benzoate), hydrides or mixtures thereof, or copolymers containing these as the main copolymerization component, preferably polystyrene, poly (hydrocarbon-substituted styrene), or copolymers containing styrene as the main copolymerization component. Is preferable, and a copolymer containing styrene as a main copolymer component (hereinafter, also referred to as a styrene-based copolymer) is more preferable.

The monomer other than styrene used as the copolymerization component of the styrene-based copolymer may be a monomer having a vinyl group and capable of copolymerizing with styrene, and may be a styrene-based monomer, an olefin monomer, a diene monomer, a cyclic olefin monomer, or a cyclic monomer. Examples thereof include a diene monomer and a polar vinyl monomer, and a styrene-based monomer is preferable.

Examples of the styrene-based monomer include hydrocarbon-substituted styrene, halogenated styrene, halogenated alkylstyrene, alkoxystyrene, and vinyl benzoic acid ester, and hydrocarbon-substituted styrene is preferable.

Examples of the hydrocarbon-substituted styrene contained in the styrene-based copolymer include methylstyrene, ethylstyrene, isopropylstyrene, tert-butylstyrene, (phenyl) styrene, vinylnaphthalene, and divinylbenzene, and methylstyrene and ethylstyrene. , Divinylbenzene is preferable, and methylstyrene is more preferable.
Examples of halogenated styrene include chlorostyrene, bromostyrene, fluorostyrene and the like.
Examples of the halogenated alkylstyrene include chloromethylstyrene and the like.
Examples of alkoxystyrene include methoxystyrene and ethoxystyrene.

Examples of the olefin monomer include ethylene, propylene, butene, hexene, and octene. Examples of the diene monomer include butadiene and isoprene. Examples of the polar vinyl monomer include methyl methacrylate, maleic anhydride, acrylonitrile and the like.

Specific examples of the styrene-based copolymer include a copolymer of styrene and paramethylstyrene, a copolymer of styrene and p-tert-butylstyrene, a copolymer of styrene and divinylbenzene, and the like. Of these, a copolymer of styrene and paramethylstyrene is preferable. That is, among the styrene-based resins, the resin (M1) is more preferably a styrene-based resin containing paramethylstyrene as a copolymerization component.
When the resin (M1) is a styrene-based resin containing paramethylstyrene as a copolymerization component, the paramethylstyrene component in the copolymerization component is preferably 3 to 15 mol%, more preferably 4 to 12 mol%. More preferably, 5-10 mol%.

The weight average molecular weight of the resin (M1) is preferably 100,000 to 300,000, more preferably 150,000 to 250,000, and even more preferably 150,000 to 200,000. The weight average molecular weight is determined by gel permeation chromatography using monodisperse polystyrene as a standard substance.
The dielectric loss tangent (tan δ) of the resin (M1) is preferably 0.00030 or less, more preferably 0.00020 or less. The dielectric loss tangent (tan δ) can be obtained by the same measurement method as the method for measuring the dielectric loss tangent of the resin laminate described in Examples.

(Characteristics of resin (M), etc.)
The thickness of the resin layer (M) is preferably 2 to 100 μm. Among them, when used for circuit board applications, 10 to 80 μm is preferable, 15 to 60 μm is more preferable, and 20 to 50 μm is even more preferable. When the thickness of the resin layer (M) is within the above range, it is possible to achieve both sufficient adhesiveness between the layers and excellent impact strength when the resin laminate is formed.
The resin layer (M) may or may not be an alignment film.

<Characteristics of resin laminate for low dielectric material, etc.>
The thickness of the resin laminate of the present invention is preferably 0.01 to 3.0 mm, more preferably 0.02 to 3.0 mm, and even more preferably 0.03 to 3.0 mm.
Among them, when used for a circuit board application, 0.03 to 1.5 mm is preferable, 0.10 to 1.0 mm is more preferable, and 0.2 to 0.9 mm is further preferable. Further, when used for a millimeter-wave radome resin plate or a good radio wave transmitting resin plate, 0.9 to 3.0 mm is preferable, and 0.9 to 2.5 mm is more preferable.
The dielectric loss tangent (tan δ) of the resin laminate of the present invention is preferably 0.00030 or less, more preferably 0.00025 or less. The dielectric loss tangent (tan δ) is a value obtained by the measuring method described in the examples. The smaller the value of the dielectric loss tangent (tan δ), the smaller the dielectric loss and the better the dielectric characteristics. Since the resin laminate of the present invention is laminated with an SPS film having excellent insulating properties, it has a low dielectric loss tangent (tan δ), and is particularly an electronic material such as a circuit board, a resin plate for a millimeter wave radome, and a good radio wave transmitting resin plate. It is considered that a laminate suitable for the above can be obtained.
When the thickness of the resin laminate of the present invention is 0.9 mm, the impact strength is preferably 0.1 J or more, more preferably 0.6 J or more, still more preferably 0.8 J or more. The impact strength here is a value obtained by the measuring method described in the examples.
The resin laminate of the present invention is considered to be excellent in impact strength because it is composed of an SPS film having excellent strength and a more flexible resin having a low softening point in close contact with each other. A more suitable SPS film is an alignment film, which is considered to have high strength, and particularly in the case of a biaxially stretched film, the orientation of polystyrene molecules is higher and the strength is further increased.

[Manufacturing method of resin laminate for low dielectric material]
The method for producing a resin laminate for a low dielectric material of the present invention is a film containing an alignment film (SF) containing a styrene resin (S1) having a syndiotactic structure and a resin (M1) having a softening point of 260 ° C. or lower. MF) is alternately laminated, and a total of three or more layers are laminated so that the outermost layer is a film (SF), and the process is pressed to integrate them.
According to the production method of the present invention, a resin layer (S) containing a styrene resin (S1) having a syndiotactic structure and a resin layer (M) containing a resin (M1) having a softening point of 260 ° C. or lower are alternately arranged. A resin laminate for a low dielectric material is obtained in which a total of three or more layers are laminated and the outermost layer is a resin layer (S).
The reason why the resin laminate thus obtained has excellent toughness and low dielectric loss is not clear, but it is considered as follows.
The oriented SPS film has excellent impact resistance, but becomes a relatively thin film for alignment. By fusing the SPS film with a resin having a relatively low softening point, the SPS film can be formed into an appropriate thickness without impairing the molecular orientation of the SPS film. Furthermore, by using a styrene resin for the resin having a low softening point, a laminate that achieves both small dielectric loss and excellent toughness can be obtained, especially for circuit boards, millimeter-wave radome resin plates, good radio wave transmitting resin plates, etc. It is considered that a laminate suitable for an electronic material can be obtained.

<Orientation film (SF)>
In this production method, an oriented film (SF) is used as the film used for each resin layer (S).
As the resin used for the alignment film (SF), it is preferable to use the SPS described in the above (styrene resin (S1) having a syndiotactic structure), and the preferable range is also described in the description of the resin (S1). Is similar to. That is, polystyrene (styrene homopolymer) is preferable.

The alignment coefficient of the alignment film (SF) calculated by wide-angle X-ray diffraction (WAXD) in the crystal portion in the film plane is -0.1000 or more and 0.0100 or less in the Throw direction and -0.5000 or more in the Edge direction. Less than 0.1000, -0.5000 or more and less than -0.1000 in the End direction, -0.0500 or more and 0.0050 or less in the Throw direction, -0.4800 or more and -0.1200 or less in the Edge direction. , -0.4800 or more and -0.1200 or less in the End direction is preferable. When the orientation coefficient is within the above range, sufficient impact strength required for a resin laminate used for applications such as circuit boards, millimeter-wave radomes, and good radio wave transmitting resin plates can be obtained.
The alignment film is a stretched film obtained by melt-extruding the resin (S1) with an extruder, cooling and solidifying with a cast roll, stretching with a stretching machine, and heat-treating the obtained film as necessary. It is preferable to have. Of these, a biaxially stretched film obtained by biaxially stretching is more preferable.
The production of the alignment film (SF) in the case of the biaxially stretched film will be described below.

The resin (S1) is preferably pre-dried before being charged into the extruder. It is more preferable to dry the pelletized resin (S1) under the conditions of 60 to 150 ° C. and 10 to 180 minutes.
As the extruder, a single-screw extruder or a twin-screw extruder can be used, and it is preferable to use an extruder with a vacuum vent in that the drying of the resin is promoted. Further, it is preferable to install a gear pump in order to suppress extrusion fluctuation, and it is more preferable to install a polymer filter after the gear pump in order to avoid foreign matter from entering.
Examples of the polymer filter include a leaf disc type and a candle type.
As the filter material of the polymer filter, a sintered metal type is preferable. The collected particle size is preferably 1 to 100 μm.
The extrusion temperature in the extruder is preferably 290 to 330 ° C. It is preferable to adjust the extrusion temperature from the heater of the extruder to the polymer line, gear pump, polymer filter and T-die.

The cooling medium of the cast roll is preferably oil or water, and the cooling temperature is preferably 50 to 95 ° C, more preferably 60 to 90 ° C.
In order to bring the resin (S1) melt-extruded from the T-die of the extruder into close contact with the cast roll, it is preferable to use an air chamber method, an electrostatic application method, or a combination thereof.
By bringing the molten resin into close contact with the cast roll and quenching it in this way, a stable and continuous cast film can be obtained in the stretching step.
The pulling speed of the cast roll is preferably 1 to 30 m / min, more preferably 3 to 15 m / min.

Next, biaxial stretching is performed. When the alignment film (SF) used in the present invention is obtained, either a simultaneous biaxial stretching method or a sequential biaxial stretching method in which transverse stretching is performed after longitudinal stretching may be performed, but simultaneous biaxial stretching may be performed. The stretching method is preferable.
In the simultaneous biaxial stretching method, since the longitudinal direction (MD) and the width direction (TD) are stretched at the same time, the physical properties of MD and TD are less likely to be biased. For example, since there is little bias in orientation between MD and TD, a laminated body having a small difference in superiority or inferiority depending on the direction can be obtained in terms of toughness when impacted.
As the simultaneous biaxial stretching method, it is preferable to use the pantograph method.
It is preferable to use a roll type longitudinal stretching machine and a tenter type transverse stretching machine for the sequential biaxial stretching method.

Regarding the stretching temperature, the preheating temperature is preferably 90 to 150 ° C., more preferably 100 to 140 ° C., and even more preferably 105 to 120 ° C.
The stretching temperature is preferably 90 to 150 ° C, more preferably 100 to 140 ° C, and even more preferably 105 to 120 ° C.
The heat fixing temperature is preferably 180 to 265 ° C, more preferably 200 to 260 ° C, and even more preferably 200 to 250 ° C.
When a pantograph type biaxial stretching machine is used, the preheating temperature is set in the preheating zone, the stretching temperature is set in the stretching zone, and the heat fixing temperature is set in the heat fixing zone.
The draw ratio is preferably 2.5 to 4.0 in the vertical direction and 2.5 to 4.0 in the horizontal direction.
In the heat-fixing zone, it is preferable to provide a relaxation rate of 0.5 to 10% in length and 0.5 to 10% in width in order to suppress post-shrinkage of the film.

In the heat-fixing zone, it is preferable to heat-treat (anneal) the stretched film, and in this way, a biaxially stretched film (SF) is obtained.
The thickness of the obtained biaxially stretched film (SF) is preferably 2 to 100 μm. Among them, when used for a circuit board application, 10 to 80 μm is preferable, 15 to 60 μm is more preferable, and 20 to 50 μm is further preferable. If the thickness of the biaxially stretched film (SF) is within the above range, it can be sufficiently oriented, especially during film molding, and excellent toughness can be obtained when the laminate is formed.

When a roll type longitudinal stretching machine is used in the sequential biaxial stretching method, the roll temperature is preferably 98 to 105 ° C. The medium for adjusting the roll temperature is preferably oil or pressurized water. The longitudinal stretching is performed by two rolls having different pulling speeds, but it is preferable to provide an auxiliary heater for heating the film between the two rolls. As the auxiliary heater, it is preferable to use a far-infrared heater. The draw ratio is preferably 2.5 to 4.0 in the vertical direction.
When a tenter type transverse stretching machine is used in the sequential biaxial stretching method, the preheating temperature is preferably 90 to 150 ° C, more preferably 100 to 140 ° C, still more preferably 105 to 120 ° C.
The stretching temperature is preferably 90 to 150 ° C, more preferably 100 to 140 ° C, and even more preferably 105 to 120 ° C.
The heat fixing temperature is preferably 180 to 265 ° C, more preferably 200 to 260 ° C, and even more preferably 200 to 250 ° C.
The draw ratio is preferably 2.5 to 4.0 in the horizontal direction.
In the heat-fixing zone, it is preferable to provide a relaxation rate of 0.5 to 10% in order to suppress the post-shrinkage of the film.

In the heat-fixing zone, it is preferable to heat-treat (anneal) the stretched film, and in this way, a biaxially stretched film (SF) is obtained.
The thickness of the obtained biaxially stretched film (SF) is preferably 2 to 100 μm. Among them, when used for a circuit board application, 10 to 80 μm is preferable, 15 to 60 μm is more preferable, and 20 to 50 μm is further preferable. If the thickness of the biaxially stretched film (SF) is within the above range, it can be sufficiently oriented, especially during film molding, and excellent toughness can be obtained when it is formed into a laminated body.

<Film (MF)>
In the present production method, the film (MF) forms the resin layer (M) of the obtained laminate. The film (MF) may be a cast film, an alignment film, or a stretched film, but an alignment film or a stretched film is preferable, and a biaxially stretched film is more preferable.
The film (MF) contains a resin (M1) having a softening point of 260 ° C. or lower. Examples of the resin (M1) include a polyphenylene ether resin and a styrene-based resin. Among them, a styrene-based resin is preferably contained, and the preferable range is the same as that described in the description of the resin (M1). That is, a styrene resin containing paramethylstyrene as a copolymerization component is preferable, and among the copolymer components, the paramethylstyrene component is more preferably 3 to 15 mol%, further preferably 4 to 12 mol%, and 5 to 10 More preferably mol%. The stereoregularity (tacticity) is preferably syndiotactic.

Examples of the method for producing a film (MF) include a melt extrusion molding method, a solution casting method, a calender method, and the like. The melt extrusion molding method is preferable, and stretching is more preferable after melt extrusion, and stretching is biaxial stretching. The method is even more preferred. The method for producing a film by a preferable biaxially stretched method is the same as that of the biaxially stretched film (SF).

Specifically, as the biaxially stretched film, the resin (M1) is melt-extruded by an extruder, cooled and solidified by a cast roll, and biaxially stretched by a stretcher, and the obtained film is obtained as needed. Obtained by heat treatment.

The resin (M1) is preferably pre-dried before being charged into the extruder. It is more preferable to dry the pelletized resin (M1) under the conditions of 60 to 150 ° C. and 10 to 180 minutes.
As the extruder, a single-screw extruder or a twin-screw extruder can be used, and it is preferable to use an extruder with a vacuum vent in that the drying of the resin is promoted. Further, it is preferable to install a gear pump in order to suppress extrusion fluctuation, and it is more preferable to install a polymer filter after the gear pump in order to avoid foreign matter from entering.
Examples of the polymer filter include a leaf disc type and a candle type.
As the filter material of the polymer filter, a sintered metal type is preferable. The collected particle size is preferably 1 to 100 μm.
The extrusion temperature in the extruder is preferably 270 to 330 ° C. It is preferable to adjust the extrusion temperature from the heater of the extruder to the polymer line, gear pump, polymer filter and T-die.

The cooling medium of the cast roll is preferably oil or water, and the cooling temperature is preferably 50 to 95 ° C, more preferably 60 to 90 ° C.
In order to bring the resin (M1) melt-extruded from the T-die of the extruder into close contact with the cast roll, it is preferable to use an air chamber method, an electrostatic application method, or a combination thereof.
By bringing the molten resin into close contact with the cast roll and quenching it in this way, a stable and continuous film can be obtained in the stretching step.
The pulling speed of the cast roll is preferably 1 to 30 m / min, more preferably 3 to 15 m / min.

Next, biaxial stretching is performed. The film (MF) used in the present invention may be either a simultaneous biaxial stretching method or a sequential biaxial stretching method in which transverse stretching is performed after longitudinal stretching, but the simultaneous biaxial stretching method is used. preferable.
In the simultaneous biaxial stretching method, since the longitudinal direction (MD) and the width direction (TD) are stretched at the same time, the physical properties of MD and TD are less likely to be biased. For example, since there is no bias in orientation between MD and TD, a laminated body having no superiority or inferiority in toughness when subjected to an impact can be obtained.
As the simultaneous biaxial stretching method, it is preferable to use the pantograph method.
It is preferable to use a roll type longitudinal stretching machine and a tenter type transverse stretching machine for the sequential biaxial stretching method.

Regarding the stretching temperature, the preheating temperature is preferably 90 to 150 ° C., more preferably 100 to 140 ° C., and even more preferably 110 to 130 ° C.
The stretching temperature is preferably 90 to 150 ° C, more preferably 100 to 140 ° C, and even more preferably 110 to 130 ° C.
The heat fixing temperature is preferably 180 to 250 ° C., more preferably 180 to 240 ° C., and even more preferably 180 to 220 ° C.
When a pantograph type biaxial stretching machine is used, the preheating temperature is set in the preheating zone, the stretching temperature is set in the stretching zone, and the heat fixing temperature is set in the heat fixing zone.
The draw ratio is preferably 2.5 to 4.0 in the vertical direction and 2.5 to 4.0 in the horizontal direction.
In the heat-fixing zone, it is preferable to provide a relaxation rate of 0.5 to 10% in length and 0.5 to 10% in width in order to suppress post-shrinkage of the film.

In the heat-fixing zone, it is preferable to heat-treat (anneal) the stretched film, and in this way, the film (MF) is obtained. The film thus obtained is a biaxially stretched film.
The thickness of the obtained biaxially stretched film (MF) is preferably 2 to 100 μm. Among them, when used for a circuit board application, 10 to 80 μm is preferable, 15 to 60 μm is more preferable, and 20 to 50 μm is further preferable. When the thickness of the biaxially stretched film (MF) is within the above range, it is possible to achieve both sufficient adhesiveness between the layers and excellent impact strength when the resin laminate is formed.

When a roll type longitudinal stretching machine is used in the sequential biaxial stretching method, the roll temperature is preferably 98 to 105 ° C. The medium for adjusting the roll temperature is preferably oil or pressurized water. The longitudinal stretching is performed by two rolls having different pulling speeds, but it is preferable to provide an auxiliary heater for heating the film between the two rolls. As the auxiliary heater, it is preferable to use a far-infrared heater. The draw ratio is preferably 2.5 to 4.0 in the vertical direction.
When a tenter type transverse stretching machine is used in the sequential biaxial stretching method, the preheating temperature is preferably 90 to 150 ° C, more preferably 100 to 140 ° C, still more preferably 110 to 130 ° C.
The stretching temperature is preferably 90 to 150 ° C, more preferably 100 to 140 ° C, and even more preferably 110 to 130 ° C.
The heat fixing temperature is preferably 180 to 250 ° C., more preferably 180 to 240 ° C., and even more preferably 180 to 220 ° C.
The draw ratio is preferably 2.5 to 4.0 in the horizontal direction.
In the heat-fixing zone, it is preferable to provide a relaxation rate of 0.5 to 10% in order to suppress the post-shrinkage of the film.

In the heat-fixing zone, it is preferable to heat-treat (anneal) the stretched film, and in this way, the film (MF) is obtained.
The thickness of the obtained film (MF) is preferably 2 to 100 μm. Among them, when used for a circuit board application, 10 to 80 μm is preferable, 15 to 60 μm is more preferable, and 20 to 50 μm is further preferable. When the thickness of the film (MF) is within the above range, it is possible to achieve both sufficient adhesiveness between the layers and excellent impact strength when the resin laminate is formed.

<Lamination / press integration process>
In this manufacturing method, a total of three or more layers are laminated, pressed, and integrated so that the film (SF) and the film (MF) are alternately laminated and the outermost layer is the film (SF).

In the laminating step, a total of three or more layers are laminated so that the film (SF) and the film (MF) are alternately arranged and the outermost layer is the film (SF).
The number of layers in this step is 3 or more, preferably 5 or more, more preferably 7 or more, further preferably 9 or more, even more preferably 15 or more, and even more preferably 22 or more. The upper limit is preferably 39 layers or less, more preferably 35 layers or less, and even more preferably 29 layers or less. By setting the number of layers to 3 or more, when an impact force is applied to the laminated body, the relatively flexible styrene resin layer with a low softening point existing between the SPS layers disperses and relaxes the impact force, and toughness. It is thought that it is increasing.
In the press integration step, it is preferable to press at 250 to 268 ° C. for integration, more preferably 255 to 265 ° C., and even more preferably 257 to 263 ° C. By pressing at 250 to 268 ° C., each resin layer can be brought into close contact with each other while maintaining the molecular orientation state of the SPS layer.
In this step, the pressing method used is not limited, but it is preferable to press and integrate by the vacuum pressing method. Further, in this step, it is preferable to use a vacuum press machine. When the vacuum press method is used, the degree of vacuum is preferably −0.05 MPa or less, the press temperature is preferably 250 to 268 ° C, and the press pressure is preferably 0.5 to 5.0 MPa, 1.0. It is more preferably about 4.0 MPa, further preferably 1.5 to 3.0 MPa. The press holding time is preferably 1 to 60 minutes, more preferably 1 to 30 minutes, and even more preferably 1 to 10 minutes.
It is preferable to obtain a resin laminate by integrating the laminated films in this way.

<Characteristics of resin laminate for low dielectric material, etc.>
The structure and characteristics of the resin laminate obtained by the production method of the present invention are preferably those described in the above section [Resin laminate for low dielectric material], and are as follows.
That is, the suitable resin laminate obtained by the production method of the present invention comprises a resin layer (S) containing a styrene resin (S1) having a syndiotactic structure and a resin (M1) having a softening point of 260 ° C. or lower. A total of three or more layers of the containing resin layers (M) are alternately laminated, and the outermost layer is the resin layer (S).
As shown in FIG. 1, when the resin laminate 1 for a low dielectric material of the present invention has three layers, both sides of the resin layer 2 (corresponding to the resin layer (M)) containing the resin (M1) having a softening point of 260 ° C. or lower. Is sandwiched between a resin layer 3 (corresponding to the resin layer (S)) containing a styrene resin (S1) having a syndiotactic structure, and the outermost layer is preferably the resin layer 3.

In the laminated body, it is preferable that the resin layers are alternately laminated and the outermost layer is the resin layer (S). That is, in the case of 3 layers, it is S / M / S, in the case of 5 layers, it is S / M / S / M / S, and in the case of 7 layers, it is S / M / S / M / S / M / S.
The number of layers is 3 or more, preferably 5 or more, more preferably 7 or more, further preferably 9 or more, even more preferably 15 or more, and even more preferably 22 or more. The upper limit is preferably 39 layers or less, more preferably 35 layers or less, and even more preferably 29 layers or less. By setting the number of layers to 3 or more, when an impact force is applied to this laminate, the relatively flexible styrene resin layer with a low softening point existing between the SPS layers disperses and relaxes the impact force, and toughness is achieved. It is thought that it can be enhanced.

The thickness of the resin laminate obtained by the production method of the present invention is preferably 0.01 to 3.0 mm, more preferably 0.02 to 3.0 mm, and even more preferably 0.03 to 3.0 mm. ..
Among them, when used for a circuit board application, 0.03 to 1.5 mm is preferable, 0.10 to 1.0 mm is more preferable, and 0.2 to 0.9 mm is further preferable. Further, when used for a millimeter-wave radome resin plate or a good radio wave transmitting resin plate, 0.9 to 3.0 mm is preferable, and 0.9 to 2.5 mm is more preferable.
The dielectric loss of the resin laminate obtained by the production method of the present invention is preferably 0.00030 or less, more preferably 0.00025 or less. The dielectric loss is a value obtained by the measuring method described in Examples. Since the entire laminate is made of a styrene resin having excellent insulating properties, it is considered that a laminate having low dielectric loss and particularly suitable for electronic materials such as circuit boards can be obtained.
When the thickness is 0.9 mm, the impact strength of the resin laminate obtained by the production method of the present invention is preferably 0.1 J or more, more preferably 0.6 J or more, still more preferably 0.8 J or more. The impact strength here is a value obtained by the measuring method described in the examples.
The resin laminate obtained by the production method of the present invention is considered to have excellent impact strength because it is composed of an SPS film having excellent strength and a more flexible resin having a low softening point in close contact with each other. A more suitable SPS film is a biaxially stretched film, which is considered to have a high orientation of polystyrene molecules and a higher strength.

[Electronic circuit boards and resin plates containing resin laminates for low-dielectric materials]
The electronic circuit board of the present invention includes the resin laminate for a low dielectric material.
Further, the electronic circuit board of the second aspect of the present invention includes a resin laminate for a low dielectric material obtained by the above-mentioned manufacturing method.
Further, the resin laminate of the present invention or the resin laminate obtained by the production method of the present invention may be used as a resin plate for a millimeter-wave radome, a good radio wave transmitting resin plate, an optical waveguide circuit plate, an array antenna, and the like. It can also be used for MIMO antennas, array antenna electrodes, electrical engineering modulators, and the like.
When the resin laminate of the present invention or the resin laminate obtained by the production method of the present invention is used as an electronic circuit board, the total thickness of the electronic circuit board is preferably 0.05 to 2.0 mm, preferably 0.4 to 2.0 mm. 1.6 mm is more preferable.
Further, the electronic circuit board of the present invention is manufactured by laminating a metal layer on one side or both sides of a substrate for an electronic circuit and patterning the metal layer. The patterning is preferably performed by etching the metal layer by a photolithography method. It is also possible to use an electroless plating method, an electrolytic plating method, a vapor deposition method, or a metal adhesion method using triazine. It is also possible to laminate a polyaniline layer containing substituted or unsubstituted polyaniline on the resin laminate of the present invention, and metallize the polyaniline layer by electroless plating or the like. This method has excellent adhesion between the resin laminate and the metal layer, and an extremely smooth metal layer can be obtained. Therefore, this method can be preferably used because an electronic circuit board having a small transmission loss can be obtained.
When the resin laminate of the present invention or the resin laminate obtained by the production method of the present invention is used as a resin plate for a millimeter wave radome or a good radio wave transmitting resin plate, the total thickness of the resin plate is 1. It is preferably 0 to 7.0 mm, more preferably 1.5 to 5.0 mm, and even more preferably 2.0 to 2.5 mm.
When the resin laminate of the present invention is used as a resin plate for a millimeter wave radome or a resin plate for transmitting good radio waves, a coating material or the like can be further laminated if necessary.

The present invention will be described in more detail by way of examples, but the present invention is not limited thereto.

(1) Weight average molecular weight of resin Gel permeation chromatography (gel permeation chromatography, abbreviated as "GPC") was used for measurement.
The measurement conditions were a GPC apparatus manufactured by Tosoh Corporation (HLC-8321GPC / HT), a GPC column manufactured by Tosoh Corporation (GMHHR-H (S) HT), and 1,2,4-trichlorobenzene as an eluent. It was measured at 145 ° C.
It was calculated as a polystyrene-equivalent molecular weight using a standard polystyrene calibration curve.

(2) Resin softening point The softening point (Vicat softening point) was measured in accordance with JIS K7206: 2016.
The measurement conditions were 3M-2 manufactured by Toyo Seiki Seisakusho Co., Ltd., A120 method, test load 10N, temperature rise rate 120 ° C / h, test start temperature 50 ° C, maximum penetration 1 mm, and measurement was performed 3 times. , The average was calculated.
The measurement sample was prepared as follows.
A mold having a depth of 3 mm was filled with resin powder, sealed, and evacuated, and at the same time, the temperature was raised and pressurized (vacuum degree: −0.1 MPa or less, press pressure: 2 MPa). The SPS (weight average molecular weight 230,000) was heated to 280 ° C. and held for 5 minutes, and then naturally cooled to 250 ° C., the pressure was returned to normal pressure, the press pressure was released, and the sample was placed in a mold. After taking it out from the water, it was naturally cooled to room temperature. The paramethylstyrene copolymer SPS (weight average molecular weight 180,000) was heated to 260 ° C. and held for 5 minutes, then naturally cooled to 230 ° C., returned to normal pressure, and the press pressure was released. After cooling and removing the sample from the mold, it was naturally cooled to room temperature.
The SPS sample and the paramethylstyrene copolymer SPS sample were annealed at 150 ° C. for 10 minutes. After annealing, each piece was cut into approximately 3 mm square pieces to prepare a sample for measurement.

(3) Impact strength The impact strength of the resin laminates of Examples and Comparative Examples was measured under the following conditions.
Test method: Compliant with JIS K5600-5-3 Test equipment: DuPont impact tester (manufactured by Tester Sangyo Co., Ltd.)
Specimen: 65 mmφ
Shooting type and cradle radius: 12.7 mm
Test environment: 23 ° C, relative humidity 50%
Judgment method: JIS K7211-1 compliant

(4) Dissipation factor (tan δ)
The dielectric loss tangent (tan δ) of the resin laminates of Examples and Comparative Examples was measured under the following conditions in accordance with JIS K6911-1995.
The smaller the value of the dielectric loss tangent (tan δ), the smaller the dielectric loss and the better the dielectric characteristics.
LCR meter: HP4284A (manufactured by Hewlett-Packard, electrode: HP16451B, applied voltage range: 42V)
Measurement frequency: 1MHz
Test size: 60 mmφ

(5) Orientation coefficient f
In wide-angle X-ray diffraction measurement, an X-ray generator (ultraX 18HF manufactured by Rigaku Denki Co., Ltd.) is used to irradiate a CuKα ray (wavelength = 1.5418 Å) monochromatic light at an output of 50 KV and 250 mA for 5 minutes, and an imaging plate is used. A diffraction image was obtained by a type two-dimensional detector. At this time, the distance (camera length) between the sample and the detector was adjusted to 105 mm.
The prepared alignment films were laminated in the same direction so as to have a thickness of 1 mm or more, and prepared as a measurement sample. By adjusting the orientation of the measurement sample and changing the incident direction of X-rays, diffraction images in the Throw, Edge, and End directions were obtained, respectively.
In calculating the crystal orientation coefficient, a diffraction peak with a diffraction angle of 2θ = 6.7 deg assigned to the (110) plane of the α-type crystal was used from the intensity profile in the equatorial direction of the obtained diffraction image.
The crystal orientation coefficient f (orientation coefficient f) of the plane normal vector with respect to the orientation axis was calculated based on the equation (F1).

Example 1 (Manufacture of resin laminate for low dielectric material)
(1) Production of biaxially stretched SPS film (SF) SPS (syndiotactic polystyrene, styrene homopolymer, softening point 265 ° C., melting point 271 ° C.) pellets having a weight average molecular weight of 230,000 are 300 by a single screw extruder. It was melted at ° C., extruded from a T-die, and cooled with a cast roll at 80 ° C. at a pulling speed of 6 m / min. The thickness of the obtained cast film was 541 μm. Then, the obtained cast film is simultaneously biaxially stretched using a pantograph type biaxial stretching machine, and the stretched film is heat-treated (annealed) to obtain a biaxially stretched SPS film (SF) having a thickness of 50 μm. Obtained. The conditions of the biaxial stretching machine are that the preheating zone and the stretching zone are set to 120 ° C. and the heat fixing zone is set to 200 ° C., and the stretching ratio of the stretching zone is 3.5 in both MD (longitudinal direction) and TD (width direction). The relaxation rate of the heat fixing zone was set to 6% in both MD (longitudinal direction) and TD (width direction).
The orientation coefficient of the obtained biaxially stretched SPS film (SF) was 0.0004 in the Throw direction, -0.3048 in the Edge direction, and -0.2758 in the End direction.

(2) Production of Biaxially Stretched Paramethylstyrene Copolymerized SPS Film (MF) with a Thickness of 25 μm Paramethylstyrene Random Copolymerized SPS with a Weight Average Molecular Weight of 180,000 (Paramethylstyrene Component 8 mol%, Softening Point 236 ° C., Melting Point 250 ° C.) The pellet was melted at 290 ° C. with a single-screw extruder, extruded from a T die, and cooled with a cast roll at 80 ° C. at a pulling speed of 6 m / min. The thickness of the obtained cast film was 271 μm. Then, the obtained cast film was simultaneously biaxially stretched using a pantograph type biaxial stretching machine, and the stretched film was heat-treated (annealed) to have a 25 μm thick biaxially stretched paramethylstyrene copolymer SPS. A film (biaxially stretched PMS / SPS film) (MF) was obtained. The conditions of the biaxial stretching machine were the same as in (1) production of the biaxially stretched SPS film (SF).

(3) Production of resin laminate A total of 27 sheets of the film (SF) obtained in (1) and the film (MF) obtained in (2) are alternately stacked so that the outermost layer is SF, and a vacuum press machine is used. The film was pressed for 3 minutes under the conditions of a vacuum degree of −0.1 MPa or less and a press pressure of 1.8 MPa and 260 ° C., then cooled to 230 ° C. and returned to atmospheric pressure to obtain a resin laminate. The thickness of the resin laminated board was 0.9 mm. Table 1 shows the values of impact strength and dielectric loss tangent (tan δ).

Comparative Example 1
A total of 20 films (SF) obtained in (1) were stacked and pressed with a vacuum press at a vacuum degree of -0.1 MPa or less and a press pressure of 1.5 MPa and 280 ° C. for 3 minutes, and then to 230 ° C. After cooling and returning to atmospheric pressure, a resin laminate was obtained. The thickness of the resin laminated board was 0.9 mm. Table 1 shows the values of impact strength and dielectric loss tangent (tan δ).

Comparative Example 2
(4) Manufacture of biaxially stretched paramethylstyrene copolymer SPS film (MF) having a thickness of 50 μm The melt extrusion is performed under the same conditions as in (2) except that the discharge amount of the resin used in the extruder is adjusted, and the thickness is increased. A 541 μm cast film was obtained. The obtained cast film is simultaneously biaxially stretched using a pantograph type biaxial stretching machine, and the stretched film is heat-treated (annealed) to obtain a biaxially stretched paramethylstyrene copolymer SPS film having a thickness of 50 μm. (Biaxially stretched PMS / SPS film) (MF) was obtained. The conditions of the biaxial stretching machine were the same as in (1) production of the biaxially stretched SPS film (SF).

A total of 20 films (MF) obtained in (4) were stacked and pressed with a vacuum press machine under the conditions of a vacuum degree of -0.1 MPa or less and a press pressure of 1.5 MPa and 260 ° C. for 3 minutes, and then to 230 ° C. After cooling and returning to atmospheric pressure, a resin laminate was obtained. The thickness of the resin laminated board was 0.9 mm. Table 1 shows the values of impact strength and dielectric loss tangent (tan δ).

Comparative Example 3 (Manufacturing of resin molded body)
(1) 80/20 (mass / mass) of SPS pellets having a weight average molecular weight of 230,000 and a styrene-based elastomer (styrene / ethylene / butylene / styrene block copolymer, SEBS) used in the production of biaxially stretched SPS film (SF). ), And pelletized with a twin-screw extruder to obtain pellets of mixed resin. The pellet was pulverized with a disc mill to obtain a resin powder having an average particle size of 500 μm. Spread the resin powder on the mold, press it with a vacuum press machine under the conditions of vacuum degree -0.1 MPa or less, press pressure 1.5 MPa, 290 ° C for 3 minutes, then cool to 230 ° C, return to atmospheric pressure, and resin molding. I got a body. The thickness of the resin molded product was 0.9 mm. Table 1 shows the values of impact strength and dielectric loss tangent (tan δ).

The resin laminate for low dielectric material of Example 1 has a small dielectric loss and has high toughness, whereas the laminates of Comparative Examples 1 and 2 have low impact strength and poor toughness. It was. Further, Comparative Example 3, which is a resin molded body containing an elastomer, had excellent impact strength but a large dielectric loss.

1 Resin laminate for low-dielectric material 2 Resin layer (resin layer (M)) containing resin (M1) having a softening point of 260 ° C or less
3 Resin layer containing styrene resin (S1) having a syndiotactic structure (resin layer (S))

Claims

A total of three or more layers of a resin layer (S) containing a styrene resin (S1) having a syndiotactic structure and a resin layer (M) containing a resin (M1) having a softening point of 260 ° C. or lower are alternately laminated, and the outermost layer. Is a resin layer (S), which is a resin laminate for low dielectric materials.
The resin laminate for a low-dielectric material according to claim 1, wherein the resin layer (S) is made of an oriented film.
The resin laminate for a low-dielectric material according to claim 1 or 2, wherein the resin layer (S) is a biaxially stretched film.
The resin laminate for a low dielectric material according to any one of claims 1 to 3, wherein the styrene resin (S1) has a weight average molecular weight of 150,000 to 250,000.
The resin laminate for a low dielectric material according to any one of claims 1 to 4, wherein the resin (M1) is a styrene resin.
The resin laminate for a low dielectric material according to any one of claims 1 to 5, wherein the resin (M1) is a styrene-based resin containing paramethylstyrene as a copolymerization component.
The resin laminate for a low dielectric material according to any one of claims 1 to 6, wherein the resin (M1) has a weight average molecular weight of 150,000 to 250,000.
The resin laminate for a low dielectric material according to claim 6 or 7, wherein the paramethylstyrene component is 3 to 15 mol% in the copolymerization component of the resin (M1).
An electronic circuit board containing the resin laminate for a low dielectric material according to any one of claims 1 to 8.
An alignment film (SF) containing a styrene resin (S1) having a syndiotactic structure and a film (MF) containing a resin (M1) having a softening point of 260 ° C. or lower are alternately alternated, and the outermost layer is a film (SF). A method for producing a resin laminate for a low dielectric material, which comprises a step of laminating a total of three or more layers and pressing to integrate them.
The method for producing a resin laminate for a low-dielectric material according to claim 10, wherein in the above step, the alignment film (SF) is a biaxially stretched film.
The method for producing a resin laminate for a low-dielectric material according to claim 10 or 11, wherein in the above step, the resin laminate is integrated by pressing at 250 to 268 ° C.
The method for producing a resin laminate for a low dielectric material according to any one of claims 10 to 12, which is pressed and integrated by a vacuum press method in the above step.
The method for producing a resin laminate for a low dielectric material according to claim 13, wherein the press pressure of the vacuum press method is 0.5 to 5.0 MPa, and the press holding time is 1 to 60 minutes.
An electronic circuit board containing a resin laminate for a low dielectric material obtained by the manufacturing method according to any one of claims 10 to 14.