JP7281381B2 - Resin laminate for low dielectric materials - Google Patents

Description

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

Polystyrene resins having a syndiotactic structure (hereinafter also referred to as SPS) have excellent properties such as mechanical strength, heat resistance, electrical properties, water absorption dimensional stability, and chemical resistance. Therefore, SPS is very useful as a resin used in various applications such as materials for electrical and electronic equipment, vehicle-mounted and electrical components, household appliances, various machine parts, and industrial materials.
Furthermore, SPS is a hydrocarbon resin obtained by polymerizing styrene monomer, and since it has low dielectric loss and insulating properties, it is being studied for use as a material for electrical and electronic equipment among the above applications.

For example, Patent Document 1 discloses an electrically insulating polystyrene film having specific values for tensile 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 laminate using SPS, Patent Document 2 discloses a resin layer containing a thermoplastic resin, a resin layer containing a syndiotactic polystyrene-based resin laminated thereon, and a third layer further thereon. A laminate for an electronic circuit board is disclosed which has first and second metal layers and has a specific peel strength between the metal layers. Furthermore, in Patent Document 3, for the purpose of suppressing wrinkles in the manufacturing process of printed circuit boards, a biaxially oriented film containing a syndiotactic polystyrene resin as a main component and having a thermal shrinkage rate before and after heat treatment within a certain range. Laminates for manufacturing flexible printed circuit boards, which are laminated with flexible films, are disclosed.

JP-A-2000-164038 JP 2015-2334 A JP 2011-088387 A

2. Description of the Related Art In recent years, along with the miniaturization of electronic devices and the increasing precision of machines, there is a demand for miniaturization and thinning of electronic and electric parts. Therefore, higher toughness and excellent dielectric properties are required for resins used in these parts, for example, resin plates with good radio wave permeability used for electronic circuit boards and housings.
Furthermore, recently, resins used in millimeter-wave radomes, which are required to have high radio wave transmittance as radar covers, are required to have higher impact resistance and superior dielectric properties than conventional resins.
Therefore, the present invention provides a resin laminate for low dielectric material, which has low dielectric loss and high toughness and is suitable for electronic parts, particularly circuit boards, resin plates for millimeter wave radomes, and resin plates with good radio wave permeability. is the subject.

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

[1]
A resin layer (S) containing a styrene-based resin (S1) having a syndiotactic structure and a resin layer (M) containing a resin (M1) having a softening point of 260° C. or less are alternately laminated for a total of three or more layers, and the outermost layer is a resin layer (S).
[2]
The resin laminate for low dielectric material according to [1], wherein the resin layer (S) is made of an oriented film.
[3]
The resin laminate for low dielectric material according to [1] or [2], wherein the resin layer (S) is made of a biaxially stretched film.
[4]
The resin laminate for low dielectric materials 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 low dielectric materials 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 resin containing paramethylstyrene as a copolymer component.
[7]
The resin laminate for low dielectric materials 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 low dielectric materials according to [6] or [7], wherein the paramethylstyrene component is 3 to 15 mol % in the copolymer components of the resin (M1).
[9]
An electronic circuit board comprising the resin laminate for low dielectric materials according to any one of [1] to [6].
[10]
An oriented 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 less are alternately formed, and the outermost layer is a resin layer (S). A method for producing a resin laminate for a low dielectric material, comprising a step of laminating a total of three or more layers so as to obtain a total of three or more layers and pressing and integrating them.
[11]
The method for producing a resin laminate for a low dielectric material according to [10], wherein in the above step, the oriented film (SF) is a biaxially stretched film.
[12]
The method for producing a resin laminate for a low dielectric material according to [10] or [11], wherein in the above step, the resin laminate is integrated by pressing at 250 to 268°C.
[13]
The method for producing a resin laminate for a low dielectric material according to any one of [10] to [12], wherein in the steps, the resin laminate for a low dielectric material is integrated by pressing by a vacuum press method.
[14]
The method for producing a resin laminate for a low dielectric material according to [13], wherein the vacuum pressing method has a press pressure of 0.5 to 5.0 MPa and a press holding time of 1 to 60 minutes.
[15]
An electronic circuit board comprising a resin laminate for a low dielectric material obtained by the manufacturing method according to any one of [10] to [14].

INDUSTRIAL APPLICABILITY According to the present invention, a resin laminate for a low dielectric material, which has a small dielectric loss and high toughness and is suitable for electronic parts, particularly circuit boards, resin plates for millimeter-wave radomes, and resin plates with good radio wave permeability, and a method for producing the same. can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view showing one embodiment of a resin laminate for low dielectric material of the present invention;

The resin laminate for a low dielectric material of the present invention includes 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 less. are alternately laminated in a total of three or more layers, and the outermost layer is the resin layer (S).
Each item will be described in detail below.

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

In the laminate of the present invention, the resin layers are alternately laminated, and the outermost layer is the resin layer (S). That is, S/M/S for 3 layers, S/M/S/M/S for 5 layers, and S/M/S/M/S/M/S for 7 layers.
The number of layers to be laminated is 3 or more, preferably 5 or more, more preferably 7 or more, still more preferably 9 or more, and even more preferably 15 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 laminations to 3 or more, when an impact force is applied to this laminate, the relatively flexible resin layer with a low softening point existing between the SPS layers disperses and mitigates the impact force, thereby increasing toughness. It is considered that

<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, still more preferably 80% by mass or more, and more preferably 90% by mass or more. It is more preferably 95% by mass or more, even more preferably 99% by mass or more, and may be 100% by mass.

(Styrene-based resin (S1) having a syndiotactic structure)
The styrene-based resin (S1) having a syndiotactic structure that constitutes the resin layer (S) has a racemic diad (r) of 75 mol% or more, preferably 85 mol% or more, and a racemic pentad (rrrr) of 30 mol. % or more, preferably 50 mol % or more.
Tacticity refers to the proportion of phenyl rings in adjacent styrene units that alternate with respect to the plane formed by the backbone of the polymer block. Syndiotacticity can be quantified by a nuclear magnetic resonance method ( ¹³ C-NMR method). A diad indicates syndiotacticity with two consecutive monomer units and a pentad with five monomer units.

Examples of the styrene-based resin (S1) include polystyrene and copolymers containing styrene as a main component, and polystyrene (styrene homopolymer) is preferred.
When a copolymer containing styrene as a main component is used as the styrene resin (S1), the styrene content is preferably at least 90 mol%, more preferably at least 95 mol%, and even more preferably at least 99 mol%.

The weight average molecular weight of the styrene-based resin (S1) is preferably 100,000 to 300,000, more preferably 150,000 to 250,000, 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. Specifically, it is obtained by the measuring method described in the Examples.
The softening point of the styrene resin (S1) is preferably higher than 260°C, more preferably 261°C or higher, still more preferably 262°C or higher, and even more preferably 263 to 267°C. A softening point can be measured based on JISK7206:2016, and can be specifically measured by the method shown in an Example.
The melting point of the styrene-based resin (S1) is preferably 265°C or higher, more preferably 267°C or higher, and even more preferably 269°C or higher. Moreover, 275 degrees C or less is preferable and 273 degrees C or less 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 a method similar to 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 properties. 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 used particularly in electronic materials such as circuit boards, resin plates for millimeter wave radomes, and resin plates with good radio wave transparency. It is thought that a laminate suitable for this can be obtained.

(Characteristics of resin layer (S), etc.)
The thickness of the resin layer (S) is preferably 2-100 μm. In particular, when used for circuit boards, the thickness is preferably 10 to 80 μm, more preferably 15 to 60 μm, and even more preferably 20 to 50 μm. If the thickness of the resin layer (S) is within the above range, sufficient orientation can be achieved particularly during film formation, and excellent toughness can be obtained when a laminate is formed.
The resin layer (S) is preferably made of an oriented film. In this specification, the oriented film means that the orientation coefficient calculated by wide-angle X-ray diffraction (WAXD) in the crystal part in the plane of the film is −0.1000 or more and 0.0100 or less in the Through direction and −0.5000 in the Edge direction. -0.1000 or more and -0.5000 or more and less than -0.1000 in the End direction. The end direction is X-ray incidence from a direction parallel to the longitudinal direction of the film, the edge direction is X-ray incidence perpendicular to this and also perpendicular to the thickness direction, and the through direction is perpendicular to the film surface. X-ray incidence. If the orientation coefficient is within the above range, it is possible to obtain sufficient impact strength necessary for resin laminates used for applications such as circuit boards, millimeter wave radomes, and high radio wave transmitting resin plates.

The orientation factor can be calculated as follows.
First, in the wide-angle X-ray diffraction measurement, an X-ray generator (manufactured by Rigaku Denki Co., Ltd., ultraX 18HF) was used to irradiate monochromatic light of CuKα rays (wavelength = 1.5418 Å) for 5 minutes at an output of 50 KV and 250 mA. Diffraction images were obtained with an imaging plate type two-dimensional detector. At this time, the distance between the sample and the detector (camera length) was adjusted to 105 mm.
The produced oriented 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 Through direction, Edge direction, and End direction were obtained.
In calculating the crystal orientation coefficient, the diffraction peak at the diffraction angle 2θ=6.7 deg attributed 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 factor f of the surface normal vector to the orientation axis is calculated based on the formula (F1).

上式（Ｆ１）におけるｃｏｓφは式（Ｆ２）で、＜ｃｏｓ²φ＞は式（Ｆ３）で、それぞれ求めることができる。

cos φ in the above formula (F1) can be obtained by the formula (F2), and <cos ² φ> can be obtained by the formula (F3).

ここで、φはＸ線回折測定における方位角であり、θは赤道方向の回折角２θの１／２、δは回折像上の子午線から回折ピーク位置までの傾き角を示す。
また、Ｉ(φ)は（１１０）面の角度φにおける回折強度である。

Here, φ is the azimuth angle in the X-ray diffraction measurement, θ is 1/2 of the diffraction angle 2θ in the equatorial direction, and δ is the tilt angle from the meridian on the diffraction image to the diffraction peak position.
Also, 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 Through direction and −0 in the Edge direction. 0.4800 or more and -0.1200 or less, and -0.4800 or more and -0.1200 or less in the End direction. As a means for adjusting the orientation coefficient to the range described above, it can be realized by adjusting the draw ratio and drawing temperature during film production, and the heat setting temperature after drawing.
Furthermore, 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 laminate of the present invention, which will be 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 surface. It is oriented in the (MD and TD) directions, and when it is formed into a laminate, it has excellent toughness when the surface receives an impact.

<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, still more preferably 95% by mass or more, and even more preferably 99% by mass or more. Preferably, it may be 100% by mass.

(Resin (M1) with a softening point of 260° C. or less)
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 softening point can be measured according to JIS K7206:2016, and specifically by the method shown in Examples.

As the resin (M1), styrene-based resins and polyphenylene ether resins are preferable, and styrene-based resins are more preferable.
When 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, the layers are less likely to separate, and the laminate of the present invention has improved toughness. It is considered that

The stereoregularity (tacticity) of the styrene-based resin used for the resin (M1) may be any of syndiotactic, isotactic and atactic, preferably syndiotactic and atactic, more preferably syndiotactic. .
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.

Specific examples of the styrene resin used for the resin (M1) include polystyrene, poly(hydrocarbon-substituted styrene), poly(halogenated styrene), poly(halogenated alkylstyrene), poly(alkoxystyrene), poly(vinyl Benzoic acid ester), hydrogenated polymers or mixtures thereof, or copolymers containing these as main copolymer components are preferred, and polystyrene, poly(hydrocarbon-substituted styrene), copolymers containing styrene as the main copolymer 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 a copolymerization component of the styrene copolymer may be any monomer that has a vinyl group and can be copolymerized with styrene. Examples include diene monomers and polar vinyl monomers, and styrene-based monomers are preferred.

Styrenic monomers include hydrocarbon-substituted styrenes, halogenated styrenes, halogenated alkylstyrenes, alkoxystyrenes, and vinyl benzoic acid esters, with hydrocarbon-substituted styrenes being preferred.

Examples of the hydrocarbon-substituted styrene contained in the styrenic copolymer include methylstyrene, ethylstyrene, isopropylstyrene, tert-butylstyrene, (phenyl)styrene, vinylnaphthalene, and divinylbenzene. , divinylbenzene, and more preferably methylstyrene.
Halogenated styrenes include chlorostyrene, bromostyrene, fluorostyrene and the like.
Halogenated alkylstyrenes include chloromethylstyrene and the like.
Alkoxystyrenes include methoxystyrene, ethoxystyrene and the like.

Olefin monomers include ethylene, propylene, butene, hexene, octene, and the like. Diene monomers include butadiene, isoprene, and the like. Polar vinyl monomers include methyl methacrylate, maleic anhydride, acrylonitrile, and the like.

Specific examples of styrene copolymers include copolymers of styrene and paramethylstyrene, copolymers of styrene and p-tert-butylstyrene, and copolymers of styrene and divinylbenzene. Among them, a copolymer of styrene and paramethylstyrene is preferred. That is, the resin (M1) is more preferably a styrenic resin containing paramethylstyrene as a copolymer component among styrenic resins.
When the resin (M1) is a styrenic 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%. 5 to 10 mol % is more preferred.

The weight average molecular weight of the resin (M1) is preferably 100,000 to 300,000, more preferably 150,000 to 250,000, 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.
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 a method similar to 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 2-100 μm. In particular, when used for circuit boards, the thickness is preferably 10 to 80 μm, more preferably 15 to 60 μm, and even more preferably 20 to 50 μm. When the thickness of the resin layer (M) is within the above range, it is possible to achieve both sufficient adhesion between the layers and excellent impact strength when forming a resin laminate.
The resin layer (M) may or may not be an oriented film.

<Characteristics, etc. of resin laminate for low dielectric material>
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, even more preferably 0.03 to 3.0 mm.
In particular, when used for circuit boards, the thickness is preferably 0.03 to 1.5 mm, more preferably 0.10 to 1.0 mm, and even more preferably 0.2 to 0.9 mm. When used for applications such as millimeter-wave radome resin plates and resin plates with good radio wave transparency, the thickness is preferably from 0.9 to 3.0 mm, more preferably from 0.9 to 2.5 mm.
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. Dielectric loss tangent (tan δ) is a value obtained by the measuring method described in Examples. The smaller the value of the dielectric loss tangent (tan δ), the smaller the dielectric loss and the better the dielectric properties. 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 used particularly in electronic materials such as circuit boards, resin plates for millimeter wave radomes, and resin plates with good radio wave transparency. It is thought that a laminate suitable for this can be obtained.
The impact strength of the resin laminate of the present invention is preferably 0.1 J or more, more preferably 0.6 J or more, and still more preferably 0.8 J or more when the thickness is 0.9 mm. The impact strength here is a value obtained by the measuring method described in Examples.
It is believed that the resin laminate of the present invention is excellent in impact strength because the SPS film, which is excellent in strength, and a softer resin having a low softening point are adhered to each other. A more suitable SPS film is an oriented film and has high strength, and in the case of a biaxially oriented film in particular, it is believed that the orientation of the 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 includes an oriented film (SF) containing a styrene resin (S1) having a syndiotactic structure and a film (M1) containing a resin (M1) having a softening point of 260° C. or lower ( MF) alternately, and a total of three or more layers are laminated so that the outermost layer is a film (SF), and pressed to integrate.
Although the reason why the resin laminate obtained in this way has excellent toughness and low dielectric loss is not clear, it is considered as follows.
Oriented SPS films have excellent impact resistance, while the orientation results in relatively thin films. By fusing the SPS film with a resin having a relatively low softening point, the SPS film can be molded to have an appropriate thickness without impairing the molecular orientation of the SPS film. Furthermore, by using a styrene-based resin as the resin having a low softening point, it becomes a laminate that achieves both a small dielectric loss and excellent toughness, and is particularly suitable for circuit boards, resin plates for millimeter wave radomes, resin plates with good radio wave permeability, etc. It is considered that a laminate suitable for electronic materials can be obtained.

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

The oriented film (SF) has an orientation coefficient of -0.1000 or more and 0.0100 or less in the Through direction and -0.5000 or more in the Edge direction, calculated by wide-angle X-ray diffraction (WAXD) in the crystal part in the film plane. 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 Through 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. If the orientation coefficient is within the above range, it is possible to obtain sufficient impact strength necessary for resin laminates used for applications such as circuit boards, millimeter wave radomes, and high radio wave transmitting resin plates.
The oriented film is a stretched film obtained by melting and 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. Preferably. Among them, a biaxially stretched film obtained by biaxially stretching is more preferable.
The production of an oriented film (SF) in the case of a biaxially stretched film is described below.

It is preferable to dry the resin (S1) in advance before charging it into the extruder. It is more preferable to dry the resin (S1) in pellet form under conditions of 60 to 150° C. for 10 to 180 minutes.
A single-screw extruder or a twin-screw extruder can be used as the extruder, and it is preferable to use an extruder with a vacuum vent from the viewpoint of promoting drying of the resin. Further, it is preferable to install a gear pump in order to suppress fluctuations in extrusion, and it is more preferable to install a polymer filter after the gear pump in order to avoid contamination by foreign substances.
Polymer filters include leaf disk type and candle type.
A sintered metal type is preferable as the filtering material of the polymer filter. The collected particle size is preferably 1 to 100 μm.
The extrusion temperature in the extruder is preferably 290-330°C. It is preferable to adjust the extruder temperature from the heater of the extruder to the polymer line, gear pump, polymer filter and T-die.

The cooling medium for the cast rolls is preferably oil or water, and the cooling temperature is preferably 50 to 95°C, more preferably 60 to 90°C.
In order to adhere the resin (S1) melted and extruded from the T-die of the extruder to the cast roll, it is preferable to use an air chamber method, an electrostatic application method, or a combination thereof.
By bringing the melted resin into close contact with the cast roll and rapidly cooling it, a cast film that is stably continuous in the stretching process can be obtained.
The drawing speed of the cast roll is preferably 1 to 30 m/min, more preferably 3 to 15 m/min.

Next, biaxial stretching is carried out. When obtaining the oriented film (SF) used in the present invention, either a simultaneous biaxial stretching method or a sequential biaxial stretching method in which lateral stretching is performed after longitudinal stretching may be used. Stretching is preferred.
In the simultaneous biaxial stretching method, the film is stretched in the longitudinal direction (MD) and the width direction (TD) at the same time, so physical properties are less likely to be uneven in the MD and TD. For example, since there is little deviation in orientation between MD and TD, a laminate can be obtained in which there is little difference in toughness depending on the direction when receiving an impact.
A pantograph system is preferably used as the simultaneous biaxial stretching system.
It is preferable to use a roll-type longitudinal stretching machine and a tenter-type transverse stretching machine for the sequential biaxial stretching method.

As for the stretching temperature, the preheating temperature is preferably 90 to 150°C, more preferably 100 to 140°C, and more preferably 105 to 120°C.
The stretching temperature is preferably 90 to 150°C, more preferably 100 to 140°C, and more preferably 105 to 120°C.
The heat setting temperature is preferably 180 to 265°C, more preferably 200 to 260°C, and 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 setting temperature is set in the heat setting zone.
The draw ratio is preferably 2.5 to 4.0 in the longitudinal direction and 2.5 to 4.0 in the lateral direction.
In the heat setting zone, it is preferable to provide a relaxation rate of 0.5 to 10% in the longitudinal direction and 0.5 to 10% in the transverse direction in order to suppress post-shrinkage of the film.

In the heat setting zone, the stretched film is preferably heat-treated (annealed), and thus a biaxially stretched film (SF) is obtained.
The thickness of the biaxially stretched film (SF) to be obtained is preferably 2 to 100 μm. In particular, when used for circuit boards, the thickness is preferably 10 to 80 μm, more preferably 15 to 60 μm, and even more preferably 20 to 50 μm. When the thickness of the biaxially stretched film (SF) is within the above range, sufficient orientation can be achieved particularly during film formation, and excellent toughness can be obtained when the film is formed into a laminate.

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 drawing speeds, and it is preferable to provide an auxiliary heater for heating the film between the two rolls. A far-infrared heater is preferably used as the auxiliary heater. The draw ratio is preferably 2.5 to 4.0 in the longitudinal 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, and more preferably 105 to 120°C as the stretching temperature.
The stretching temperature is preferably 90 to 150°C, more preferably 100 to 140°C, and more preferably 105 to 120°C.
The heat setting temperature is preferably 180 to 265°C, more preferably 200 to 260°C, and more preferably 200 to 250°C.
The horizontal draw ratio is preferably 2.5 to 4.0.
The heat setting zone preferably has a relaxation rate of 0.5 to 10% in order to suppress post-shrinkage of the film.

In the heat setting zone, the stretched film is preferably heat-treated (annealed), and thus a biaxially stretched film (SF) is obtained.
The thickness of the biaxially stretched film (SF) to be obtained is preferably 2 to 100 μm. In particular, when used for circuit boards, the thickness is preferably 10 to 80 μm, more preferably 15 to 60 μm, and even more preferably 20 to 50 μm. When the thickness of the biaxially stretched film (SF) is within the above range, sufficient orientation can be achieved particularly during film formation, and excellent toughness can be obtained when the film is formed into a laminate.

<Film (MF)>
In this manufacturing method, the film (MF) forms the resin layer (M) of the resulting laminate. The film (MF) may be a cast film, an oriented film, or a stretched film, preferably an oriented film or stretched film, and more preferably a biaxially stretched film.
The film (MF) contains a resin (M1) having a softening point of 260° C. or lower. Examples of the resin (M1) include polyphenylene ether resins, styrene resins, etc. Among them, it is preferable to include styrene resins. That is, a styrene-based resin having paramethylstyrene as a copolymer component is preferable, and the paramethylstyrene component in the copolymer component is more preferably 3 to 15 mol%, and the stereoregularity (tacticity) is syndiotactic. is more preferable.

The method for producing the film (MF) includes a melt extrusion molding method, a solution casting method, a calendering method, etc., preferably a melt extrusion molding method, more preferably stretching after melt extrusion, and stretching is biaxial stretching. More preferably, the method. A preferred method for producing a film by biaxial stretching is the same as that for the biaxially stretched film (SF).

Specifically, the biaxially stretched film is produced by melt-extruding the resin (M1) with an extruder, cooling and solidifying it with a cast roll, biaxially stretching with a stretching machine, and optionally disposing the obtained film. Obtained by heat treatment.

It is preferable to dry the resin (M1) in advance before charging it into the extruder. It is more preferable to dry the resin (M1) in pellet form under conditions of 60 to 150° C. for 10 to 180 minutes.
A single-screw extruder or a twin-screw extruder can be used as the extruder, and it is preferable to use an extruder with a vacuum vent from the viewpoint of promoting drying of the resin. Further, it is preferable to install a gear pump in order to suppress fluctuations in extrusion, and it is more preferable to install a polymer filter after the gear pump in order to avoid contamination by foreign substances.
Polymer filters include leaf disk type and candle type.
A sintered metal type is preferable as the filtering material of the polymer filter. The collected particle size is preferably 1 to 100 μm.
The extrusion temperature in the extruder is preferably 270-330°C. It is preferable to adjust the extruder temperature from the heater of the extruder to the polymer line, gear pump, polymer filter and T-die.

The cooling medium for the cast rolls is preferably oil or water, and the cooling temperature is preferably 50 to 95°C, more preferably 60 to 90°C.
In order to adhere the resin (M1) melted and extruded from the T-die of the extruder to the cast roll, it is preferable to use an air chamber method, an electrostatic application method, or a combination thereof.
By bringing the melted resin into close contact with the cast roll and rapidly cooling it, a stable and continuous film can be obtained in the stretching process.
The drawing 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. preferable.
In the simultaneous biaxial stretching method, the film is stretched in the longitudinal direction (MD) and the width direction (TD) at the same time, so physical properties are less likely to be uneven in the MD and TD. For example, since there is no bias in orientation between MD and TD, a laminate can be obtained in which there is no superiority or inferiority in toughness when subjected to impact depending on the direction.
A pantograph system is preferably used as the simultaneous biaxial stretching system.
It is preferable to use a roll-type longitudinal stretching machine and a tenter-type transverse stretching machine for the sequential biaxial stretching method.

As for the stretching temperature, the preheating temperature is preferably 90 to 150°C, more preferably 100 to 140°C, and more preferably 110 to 130°C.
The stretching temperature is preferably 90 to 150°C, more preferably 100 to 140°C, even more preferably 110 to 130°C.
The heat setting temperature is preferably 180 to 250°C, more preferably 180 to 240°C, 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 setting temperature is set in the heat setting zone.
The draw ratio is preferably 2.5 to 4.0 in the longitudinal direction and 2.5 to 4.0 in the lateral direction.
In the heat setting zone, it is preferable to provide a relaxation rate of 0.5 to 10% in the longitudinal direction and 0.5 to 10% in the transverse direction in order to suppress post-shrinkage of the film.

In the heat setting zone, the stretched film is preferably heat-treated (annealed), and thus the film (MF) is obtained. The film thus obtained is a biaxially stretched film.
The thickness of the biaxially stretched film (MF) to be obtained is preferably 2 to 100 μm. In particular, when used for circuit boards, the thickness is preferably 10 to 80 μm, more preferably 15 to 60 μm, and even more preferably 20 to 50 μm. When the thickness of the biaxially stretched film (MF) is within the above range, it is possible to achieve both sufficient adhesiveness between layers and excellent impact strength when forming a resin laminate.

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 drawing speeds, and it is preferable to provide an auxiliary heater for heating the film between the two rolls. A far-infrared heater is preferably used as the auxiliary heater. The draw ratio is preferably 2.5 to 4.0 in the longitudinal direction.
When a tenter-type transverse stretching machine is used in the sequential biaxial stretching method, the stretching temperature is preferably 90 to 150°C, more preferably 100 to 140°C, and more preferably 110 to 130°C.
The stretching temperature is preferably 90 to 150°C, more preferably 100 to 140°C, even more preferably 110 to 130°C.
The heat setting temperature is preferably 180 to 250°C, more preferably 180 to 240°C, even more preferably 180 to 220°C.
The horizontal draw ratio is preferably 2.5 to 4.0.
The heat setting zone preferably has a relaxation rate of 0.5 to 10% in order to suppress post-shrinkage of the film.

In the heat setting zone, the stretched film is preferably heat-treated (annealed), and thus the film (MF) is obtained.
The thickness of the resulting film (MF) is preferably 2-100 μm. In particular, when used for circuit boards, the thickness is preferably 10 to 80 μm, more preferably 15 to 60 μm, and even more preferably 20 to 50 μm. When the thickness of the film (MF) is within the above range, it is possible to achieve both sufficient adhesiveness between layers and excellent impact strength when forming a resin laminate.

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

In the lamination step, the film (SF) and the film (MF) are laminated alternately, and a total of three or more layers are laminated so that the outermost layer is the film (SF).
The number of layers to be laminated in this step is 3 or more, preferably 5 or more, more preferably 7 or more, still more preferably 9 or more, and even more preferably 15 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 laminations to 3 or more, when an impact force is applied to the laminate, the relatively flexible styrene-based resin layer with a low softening point present between the SPS layers disperses and mitigates the impact force, thereby improving toughness. is thought to increase the
In the press integration step, it is preferable to integrate by pressing at 250 to 268°C, more preferably 255 to 265°C, even more preferably 257 to 263°C. By pressing at 250 to 268° C., each resin layer can be adhered while maintaining the molecular orientation state of the SPS layer.
In this step, the pressing method to be used is not limited, but it is preferable to press and integrate by a vacuum pressing method. Moreover, it is preferable to use a vacuum press in this step. As for the pressing conditions when a vacuum pressing method is used, the degree of vacuum is preferably −0.05 MPa or less, the pressing temperature is preferably 250 to 268° C., the pressing pressure is preferably 0.5 to 5.0 MPa, and 1.0 ~4.0 MPa is more preferable, and 1.5 to 3.0 MPa is even more preferable. 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 manner.

<Characteristics, etc. of resin laminate for low dielectric material>
The structure and characteristics of the resin laminate obtained by the production method of the present invention are preferably those described in the section [Resin laminate for low dielectric material], and are as follows.
That is, a 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 less. A total of three or more 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 a resin layer 2 (corresponding to the resin layer (M)) containing a resin (M1) having a softening point of 260° C. or less is sandwiched between resin layers 3 (corresponding to the resin layer (S)) containing a styrene-based resin (S1) having a syndiotactic structure, and the outermost layer is preferably the resin layer 3.

In the laminate, the resin layers are alternately laminated, and the outermost layer is preferably the resin layer (S). That is, S/M/S for 3 layers, S/M/S/M/S for 5 layers, and S/M/S/M/S/M/S for 7 layers.
The number of layers to be laminated is 3 or more, preferably 5 or more, more preferably 7 or more, still more preferably 9 or more, and even more preferably 15 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 laminations to 3 or more, when an impact force is applied to the laminate, the relatively flexible styrene-based resin layer with a low softening point present between the SPS layers disperses and mitigates the impact force, thereby improving toughness. can be increased.

Further, 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, even more preferably 0.03 to 3.0 mm. .
In particular, when used for circuit boards, the thickness is preferably 0.03 to 1.5 mm, more preferably 0.10 to 1.0 mm, and even more preferably 0.2 to 0.9 mm. When used for applications such as millimeter-wave radome resin plates and resin plates with good radio wave transparency, the thickness is preferably from 0.9 to 3.0 mm, more preferably from 0.9 to 2.5 mm.
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. Dielectric loss is a value obtained by the measuring method described in Examples. Since the laminate as a whole is made of a styrene-based resin with excellent insulating properties, it is thought that a laminate with low dielectric loss and particularly suitable for electronic materials such as circuit boards can be obtained.
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, and still more preferably 0.8 J or more when the thickness is 0.9 mm. The impact strength here is a value obtained by the measuring method described in Examples.
The resin laminate obtained by the production method of the present invention is considered to have excellent impact strength because the SPS film, which has excellent strength, and a softer resin having a low softening point are in close contact with each other. A more suitable SPS film is a biaxially stretched film, which is considered to have a high degree of orientation of polystyrene molecules and a higher strength.

[Electronic circuit board including resin laminate for low dielectric material, and resin plate]
The electronic circuit board of the present invention includes the resin laminate for low dielectric material.
Further, an electronic circuit board according to a second aspect of the present invention includes the resin laminate for low dielectric material obtained by the above manufacturing method.
Furthermore, 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 resin plate with good radio wave permeability, an optical waveguide circuit board, an array antenna, It can also be used in MIMO antennas, array antenna electrode electrical 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 overall thickness of the electronic circuit board is preferably 0.05 to 2.0 mm, more preferably 0.4 to 0.4 mm. 1.6 mm is more preferred.
Also, the electronic circuit board of the present invention is manufactured by laminating a metal layer on one or both sides of an electronic circuit board and patterning the metal layer. Patterning is preferably performed by etching the metal layer by photolithography. An electroless plating method, an electrolytic plating method, a vapor deposition method, and a metal adhesion method using triazine can also be used. A polyaniline layer containing substituted or unsubstituted polyaniline may be laminated on the resin laminate of the present invention, and the polyaniline layer may be metallized by electroless plating or the like. This method provides excellent adhesion between the resin laminate and the metal layer and provides a very smooth metal layer. Therefore, this method can be preferably used because an electronic circuit board with 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 resin plate with good radio wave transmission, the total thickness of the resin plate is 1.5. 0 to 7.0 mm is preferred, 1.5 to 5.0 mm is more preferred, and 2.0 to 2.5 mm is even more preferred.
When the resin laminate of the present invention is used as a resin plate for a millimeter wave radome or a resin plate with good radio wave permeability, a coating material or the like can be further laminated as necessary.

EXAMPLES The present invention will be described in more detail with reference to Examples, but the present invention is not limited to these.

(1) Weight Average Molecular Weight of Resin Measured by a gel permeation chromatography (gel permeation chromatography, abbreviated as “GPC”) measurement method.
Measurement conditions are GPC apparatus manufactured by Tosoh Corporation (HLC-8321GPC/HT), GPC column manufactured by Tosoh Corporation (GMHHR-H(S)HT), using 1,2,4-trichlorobenzene as an eluent, Measured at 145°C.
It was calculated as a polystyrene equivalent molecular weight using a standard polystyrene calibration curve.

(2) Softening point of resin The softening point (Vicat softening point) was measured according to JIS K7206:2016.
The measurement conditions are 3M-2 manufactured by Toyo Seiki Seisakusho Co., Ltd., A120 method, test load 10 N and temperature increase rate 120 ° C./h, test start temperature 50 ° C., maximum penetration depth 1 mm. , the average of which was calculated.
A sample for measurement was prepared as follows.
A mold with a depth of 3 mm was filled with resin powder, sealed, and evacuated. SPS (weight average molecular weight 230,000) was heated to 280°C and held for 5 minutes, then naturally cooled to 250°C. After taking it out of the oven, 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, the pressure was returned to normal pressure and the press pressure was released. After cooling, the sample was taken out from the mold and allowed to cool naturally 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 squares to obtain samples 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: Conforms to JIS K5600-5-3 Test equipment: DuPont impact tester (manufactured by Tester Sangyo Co., Ltd.)
Test piece: 65mmφ
Shot type and cradle radius: 12.7 mm
Test environment: 23°C, relative humidity 50%
Judgment method: JIS K7211-1 compliant

(4) Dielectric loss tangent (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 properties.
LCR meter: HP4284A (manufactured by Hewlett-Packard, electrode: HP16451B, applied voltage range: 42 V)
Measurement frequency: 1MHz
Test size: 60mmφ

(5) orientation factor f
In the wide-angle X-ray diffraction measurement, an X-ray generator (manufactured by Rigaku Denki Co., Ltd., ultraX 18HF) was used to irradiate the imaging plate with monochromatic light of CuKα rays (wavelength = 1.5418 Å) at an output of 50 KV and 250 mA for 5 minutes. Diffraction images were obtained with a two-dimensional detector. At this time, the distance between the sample and the detector (camera length) was adjusted to 105 mm.
The produced oriented 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 Through direction, the Edge direction, and the End direction were obtained.
In calculating the crystal orientation coefficient, the diffraction peak at the diffraction angle 2θ=6.7 deg attributed 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 factor f (orientation factor f) of the surface normal vector to the orientation axis was calculated based on the formula (F1).

上式（Ｆ１）におけるｃｏｓφは式（Ｆ２）で、＜ｃｏｓ²φ＞は式（Ｆ３）で、それぞれ求めることができる。

cos φ in the above formula (F1) can be obtained by the formula (F2), and <cos ² φ> can be obtained by the formula (F3).

ここで、φはＸ線回折測定における方位角であり、θは赤道方向の回折角２θの１／２、δは回折像上の子午線から回折ピーク位置までの傾き角を示す。
また、Ｉ(φ)は（１１０）面の角度φにおける回折強度である。

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

Example 1 (Production 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 with a weight average molecular weight of 230,000 are extruded at 300°C with a single screw extruder. °C, extruded through a T-die, and cooled with a cast roll at 80°C at a drawing speed of 6 m/min. The thickness of the resulting cast film was 541 μm. Then, the obtained cast film is subjected to simultaneous biaxial stretching 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 were set at 120° C. for the preheating zone and the stretching zone, and 200° C. for the heat setting zone, and the stretching ratio of the stretching zone was 3.5 in both MD (longitudinal direction) and TD (transverse direction). The relaxation rate of the heat setting zone was set to 6% in both MD (longitudinal direction) and TD (width direction).
The orientation coefficients of the obtained biaxially stretched SPS film (SF) were 0.0004 in the Through direction, −0.3048 in the Edge direction, and −0.2758 in the End direction.

(2) Production of biaxially stretched paramethylstyrene copolymer SPS film (MF) having a thickness of 25 μm Paramethylstyrene random copolymer SPS with a weight average molecular weight of 180,000 (paramethylstyrene component 8 mol%, softening point 236 ° C., melting point 250° C.) Pellets were melted at 290° C. with a single-screw extruder, extruded through a T-die, and cooled with a cast roll at 80° C. at a casting speed of 6 m/min. The thickness of the resulting cast film was 271 μm. Thereafter, the obtained cast film was subjected to simultaneous biaxial stretching using a pantograph type biaxial stretching machine, and the stretched film was heat-treated (annealed) to form a biaxially stretched paramethylstyrene copolymer SPS having a thickness of 25 μm. A film (biaxially oriented 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 is applied. was pressed at 260° C. for 3 minutes at a vacuum of −0.1 MPa or less, a press pressure of 1.8 MPa, and then cooled to 230° C. and returned to atmospheric pressure to obtain a resin laminate. The thickness of the resin laminate was 0.9 mm. Table 1 shows values of impact strength and dielectric loss tangent (tan δ).

Comparative example 1
A total of 20 sheets of the film (SF) obtained in (1) were stacked, and pressed with a vacuum press at a degree of vacuum of -0.1 MPa or less, 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 laminate was 0.9 mm. Table 1 shows values of impact strength and dielectric loss tangent (tan δ).

Comparative example 2
(4) Production of biaxially stretched paramethylstyrene copolymer SPS film (MF) with a thickness of 50 μm A cast film of 541 μm was obtained. The resulting cast film is simultaneously biaxially stretched using a pantograph type biaxial stretching machine, and the stretched film is heat-treated (annealed) to form 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 sheets of the film (MF) obtained in (4) are stacked, and pressed with a vacuum press at a degree of vacuum of -0.1 MPa or less, 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 laminate was 0.9 mm. Table 1 shows values of impact strength and dielectric loss tangent (tan δ).

Comparative Example 3 (manufacture of resin molding)
(1) SPS pellets with a weight average molecular weight of 230,000 used in the production of biaxially stretched SPS film (SF) and styrene-based elastomer (styrene-ethylene-butylene-styrene block copolymer, SEBS) were mixed at 80/20 (mass/mass ) and pelletized with a twin-screw extruder to obtain pellets of the mixed resin. The pellets were 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 with a vacuum press under the conditions of -0.1 MPa or less of vacuum, press pressure of 1.5 MPa, and 290 ° C. for 3 minutes, then cool to 230 ° C., return to atmospheric pressure, resin molding got a body The thickness of the resin molding was 0.9 mm. Table 1 shows values of impact strength and dielectric loss tangent (tan δ).

The resin laminate for low dielectric materials of Example 1 has a small dielectric loss and high toughness, whereas the laminates of Comparative Examples 1 and 2 have low impact strength and poor toughness. rice field. Further, Comparative Example 3, which is a resin molding containing an elastomer, has excellent impact strength, but has a large dielectric loss.

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

Claims (13)

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 less and not containing isotactic polypropylene are alternately arranged. A total of three or more layers are laminated, and the outermost layer is a resin layer (S),
An electronic circuit board including a resin laminate for a low dielectric material, wherein the resin (M1) is a styrene-based resin containing paramethylstyrene as a copolymer component . 2. The electronic circuit board comprising the resin laminate for a low dielectric material according to claim 1, wherein the resin layer (S) comprises an oriented film. 3. The electronic circuit board comprising the resin laminate for low dielectric material according to claim 1 or 2, wherein the resin layer (S) comprises a biaxially stretched film. The electronic circuit board comprising the resin laminate for low dielectric materials 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 electronic circuit board comprising the resin laminate for low dielectric materials according to any one of claims 1 to 4, wherein the stereoregularity of the styrene resin used for the resin (M1) is syndiotactic. An electronic circuit board comprising the resin laminate for a low dielectric material according to any one of claims 1 to 5 , wherein the resin (M1) has a weight average molecular weight of 150,000 to 250,000. 7. The electronic circuit board comprising the resin laminate for a low dielectric material according to any one of claims 1 to 6 , wherein the paramethylstyrene component is 3 to 15 mol% in the copolymer components of the resin (M1). An oriented 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 less and not containing isotactic polypropylene are alternately A total of three or more layers are laminated so that the outermost layer is a film (SF) , and a step of pressing and integrating is included, and the resin (M1) is a styrene resin containing paramethylstyrene as a copolymer component. A method for manufacturing an electronic circuit board comprising the resin laminate for a low dielectric material according to any one of claims 1 to 7 . 9. The method for producing an electronic circuit board according to claim 8 , wherein the oriented film (SF) in said step is a biaxially stretched film. 10. The method of manufacturing an electronic circuit board according to claim 8 , wherein in said step, the components are integrated by pressing at 250 to 268°C. 11. The method of manufacturing an electronic circuit board according to any one of claims 8 to 10 , wherein in said step, the components are pressed and integrated by a vacuum press method. 12. The method for manufacturing an electronic circuit board according to claim 11 , wherein the vacuum press method has a press pressure of 0.5 to 5.0 MPa and a press holding time of 1 to 60 minutes. An electronic circuit board obtained by the manufacturing method according to any one of claims 8 to 12 .

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