Polystyrene substrate, laminate, and method for producing a polystyrene substrate

Abstract

To provide a resin base material which is composed of a resin molding obtained using a resin having small surface free energy, and is excellent in bond strength to a metal film.SOLUTION: A polystyrene base material has adhesiveness, wherein the polystyrene base material is composed of a resin molding containing syndiotactic polystyrene as a main component, a molecule bond component which has 1,3,5-triazine and an alkoxysilyl group or a silanol group, and is derived from a molecule bond is bonded to the surface of the resin molding through an amino group, and an intensity ratio I902 / I906 of peak intensity I902 at 902 cm-1 in ATR-IR measurement to peak intensity I906 at 906 cm-1 is less than 1.0.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a polystyrene substrate, a laminate, and a method for producing a polystyrene substrate.

Background Art

[0002] In recent years, with the increase in the amount of transmitted information in the field of information and communication equipment, the frequency of the signal band to be handled has been increasing. So far, high-frequency signals exceeding the GHz band have been used for applications such as radar and satellite communication. However, recently, they have become extremely commonly used in portable terminals such as smartphones and tablet computers, and wireless LAN (Local Area Network).

[0003] In addition, with the increase in the speed and functionality of computers and communication equipment, the signals used for information transmission between these devices have also been made to have higher frequencies.

[0004] Conventionally, polyimide films have mainly been used as materials for flexible printed wiring boards used for forming electronic circuits. However, polyimide films could not be used for high-frequency circuits because of their poor dielectric properties in the high-frequency band and large transmission losses. In addition, polyimide is a material with a large dimensional change due to moisture absorption, and there are problems such as obstacles to the stability of processing pattern accuracy and electrical characteristics with respect to the high density of circuits.

[0005] In response to this problem, since resins having no polarized functional groups such as cyclic polyolefins and syndiotactic polystyrene have excellent electrical properties, these resins have been proposed as materials for substrates for high-frequency bands and research and development has been carried out in recent years. Non-Patent Document 1 describes that syndiotactic polystyrene has a low dielectric constant, a low dielectric tangent, and excellent moisture absorption dimensional stability and transparency.

Prior Art Documents

Non-Patent Documents

[0006]

Non - Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, materials with excellent electrical properties such as cyclic polyolefin and syndiotactic polystyrene have a problem that when adhered to a metal with an adhesive or the like, the adhesion strength is low because the surface free energy is small.

[0008] Therefore, the present invention has been made in view of the above problems, and its object is to provide a resin base material that is composed of a resin molded body obtained by using a resin having a small surface free energy and has excellent adhesion strength to a metal film.

Means for Solving the Problems

[0009] The polystyrene base material according to the present invention is an adhesive polystyrene base material, and the polystyrene base material is composed of a resin molded body containing syndiotactic polystyrene as a main component, and a molecular bonding agent component derived from a molecular bonding agent having 1,3,5 - triazine and an alkoxysilyl group or a silanol group is bonded to the surface of the resin molded body via an amino group, and in ATR - IR measurement, the peak intensity I at 902 cm -1 and the peak intensity I at 906 cm 902 and the intensity ratio I of the peak intensity I at 906 cm -1 to the peak intensity I at 902 cm 906 is less than 1.0, which is a polystyrene base material. 902 / I 906

Effects of the Invention

[0010] ​According to the present invention, it is possible to provide a resin substrate that is composed of a resin molded body obtained using a resin having a low surface free energy and has excellent adhesion strength to a metal film.

Brief Description of the Drawings

[0011]

Figure 1

Embodiments for Carrying Out the Invention

[0012] Hereinafter, an embodiment for carrying out the present invention will be described. Note that the embodiments described below show examples of typical embodiments of the present invention, and the scope of the present invention is not construed narrowly thereby.

[0013] <Polystyrene substrate> The polystyrene substrate according to the present embodiment is composed of a resin molded body whose surface is treated with a molecular bonding agent.

[0014] (Resin molded body) The resin molded body in the present embodiment contains syndiotactic polystyrene as a main component.

[0015] The “main component” as used herein means that the proportion of syndiotactic polystyrene in the entire resin forming the resin molded body is 50% by mass or more. Further, the proportion of syndiotactic polystyrene in the entire resin forming the resin molded body is preferably 60% by mass or more, and most preferably 80% by mass or more.

[0016] The resin that serves as the material for forming the resin molded body (hereinafter referred to as "material resin") only needs to contain syndiotactic polystyrene as the main component, and the resin molded body may contain other resins. For example, polyolefins such as polyethylene and polystyrene, polyesters such as polyethylene terephthalate, or those obtained by reducing the unsaturated groups of these resins with hydrogen may be included.

[0017] In addition, the resin molded body may contain inorganic fillers such as glass, calcium carbonate, silica, and talc, as well as additives such as elastomers, as long as the effects of the present invention are not inhibited.

[0018] The form of the resin molded body is not particularly limited as long as it can be formed by melt extrusion, and examples include sheet form, film form, round bar, and square bar.

[0019] Syndiotactic polystyrene is a crystalline resin. A general substrate of syndiotactic polystyrene is generally provided in an annealed state. Therefore, the crystallinity of syndiotactic polystyrene in the substrate is high. On the other hand, the surface of the resin molded body of the present embodiment is in an amorphous-rich state. Here, the "amorphous-rich state" refers to a state where, when measuring the crystallinity of the resin on the surface of the resin molded body, the amorphous resin is more than the α-crystalline resin. Whether the surface of the resin molded body is in an amorphous-rich state can be determined from the spectrum obtained by ATR-IR measurement.

[0020] Generally, the crystallinity is determined by waveform separation of the obtained spectrum. Specifically, the obtained spectrum is baseline corrected with a cubic spline curve at 925 cm -1 , 917 cm -1 , 890 cm -1 , 885 cm -1 and at 901.9 ± 0.1 cm -1 , 906.9 ± 0.1 cm -1 , 911.5 ± 0.1 cm -1Using the Levenberg Marquardt method, waveform separation is performed on a Gaussian curve with as the vertex and the same half-width. The peaks obtained by waveform separation correspond to the α-crystal, amorphous, and β-crystal of syndiotactic polystyrene, respectively. The degree of crystallinity is determined by the following formula. Degree of crystallinity = (peak area of 901.9) + (peak area of 911.9) / (total peak area) However, the above calculation method involves complicated waveform separation. Since the contribution of the β-crystal is 10% or less, in this embodiment, as a simple evaluation index, without performing waveform separation, the peak intensity I of 902 cm showing the α-crystal state in the obtained spectrum -1 and the peak intensity I of 906 cm showing the amorphous resin 902 are used, and the intensity ratio I -1 of them is used as an index of the degree of crystallinity. 906 / I 902 / I 906 is used as an index of the degree of crystallinity.

[0021] In this embodiment, if the intensity ratio I 902 / I 906 is less than 1.0, the resin molded body is in an amorphous-rich state. The intensity ratio I 902 / I 906 is preferably less than 1.0, and particularly preferably less than 0.90. Also, from the viewpoint of realizing an amorphous-rich state in a resin molded body using syndiotactic polystyrene, the intensity ratio I 902 / I 906 may be 0.5 or more. When a polystyrene substrate using a resin molded body with an amorphous-rich surface is adhered to a metal film by the same process as a polystyrene substrate that is not in an amorphous-rich state where the intensity ratio I 902 / I 906 is 1.0 or more, the peel strength of the laminate increases.

[0022] By subjecting a polystyrene substrate to ATR-IR measurement, the crystallinity of the resin molded body can be measured. Although the surface of the polystyrene substrate is treated with a molecular bonding agent, the components derived from the molecular bonding agent are formed as a sufficiently thin layer and thus do not affect the measurement of the crystallinity of the resin molded body.

[0023] As will be described later, in the cooling step of the manufacturing process of the polystyrene substrate, by setting the cooling temperature to 140°C or lower, which is the cold crystallization temperature (Tcc) of syndiotactic polystyrene, the crystallinity of the surface of the resin molded body can be reduced. As shown in FIG. 1, when the cooling temperatures are 80°C and 120°C which are 140°C or lower, the intensity ratio I 902 / I 906 is less than 1, and it is in an amorphous-rich state. However, when the cooling temperatures are 160°C and 180°C which are 140°C or higher, the intensity ratio I 902 / I 906 is greater than 1, and the crystallinity is high. Although the surface of the resin molded body in the polystyrene substrate of the present embodiment is in an amorphous-rich state, after the polystyrene substrate and the metal film are adhered by hot pressing to form a laminate, the crystallinity of the surface of the resin molded body may be high.

[0024] From the viewpoint of further increasing the peel strength, the crystallinity of syndiotactic polystyrene on the surface of the resin molded body after cooling is preferably 70% or less, more preferably 60% or less, and even more preferably 50% or less of the crystallinity of the crystalline resin on the surface of the resin molded body after forming the laminate, when the laminate is subjected to the annealing treatment described later.

[0025] (Molecular bonding agent) In the present embodiment, the polystyrene substrate is obtained by treating the surface of the above-described resin molded body with a molecular bonding agent.

[0026] The molecular bonding agent in this embodiment has a 1,3,5-triazine ring, an azide group, and an alkoxysilyl group or a silanol group. The azide group of the molecular bonding agent reacts with the resin of the resin molded body to form a covalent bond with the resin on the surface of the resin molded body. On the other hand, the alkoxysilyl group or silanol group of the molecular bonding agent reacts with the metal of the metal film to form a mixed oxide with the metal. In this way, the resin molded body and the metal film are connected via the molecular bonding agent, so that the metal film and the resin molded body can be in an adhered state. Note that the bonding of the molecular bonding agent to the metal film and the resin molded body is not limited to the case where it is bonded by one molecule of the molecular bonding agent, and the molecular bonding agents may react and bond to each other, and the bonded molecules may bond to the metal film and the resin molded body.

[0027] In addition to the above-described configuration, the molecular bonding agent may have Q as an arbitrary group so that the bonding with the resin molded body or the metal film becomes stronger. For example, Q may be a substituent of the 1,3,5-triazine ring. Further, Q preferably contains an azide group or a -NR 5 R 6 group. Here, R 5 and R 6 are each independently H, a hydrocarbon group having 1 to 24 carbon atoms, or -R 7 -SiR 8 n (OA) 3-n wherein R 7 is a linear divalent hydrocarbon group having 1 to 12 carbon atoms, and R 8 is a linear hydrocarbon group having 1 to 4 carbon atoms. A is H or a linear hydrocarbon group having 1 to 4 carbon atoms, and n is an integer of 0 to 3. When Q is an azide group, the number of bonding sites between the molecular bonding agent and the resin molded body increases. Also, when Q is a -NR 5 R 6 group, the number of bonding sites between the molecular bonding agent and the metal film increases.

[0028] The molecular bonding agent is not particularly limited as long as it is a compound having a 1,3,5-triazine ring, an azide group, and an alkoxysilyl group or a silanol group, but a compound represented by the following general formula (I) is preferably used.

[0029] [Chemical formula]

[0030] In formula (I), R 1 is an alkylene group having 1 to 10 carbon atoms. R 2 ~R 4 are each independently a hydroxy group, an alkoxy group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms, and at least one of R 2 ~R 4 is a hydroxy group or an alkoxy group having 1 to 5 carbon atoms.

[0031] Also, in formula (I), Q is an azide group or -NR 5 R 6 where R 5 and R 6 are each independently H, a hydrocarbon group having 1 to 24 carbon atoms, or -R 7 -SiR 8 n (OA) 3-n where R 7 is a linear divalent hydrocarbon group having 1 to 12 carbon atoms, R 8 is a linear hydrocarbon group having 1 to 4 carbon atoms. A is H or a linear hydrocarbon group having 1 to 4 carbon atoms, and n is an integer from 0 to 3. E is -NH-, -O-, -S-, or -NHCO-.

[0032] R 1 Among them, R is preferably an alkylene group having 1 to 8 carbon atoms, more preferably an alkylene group having 1 to 5 carbon atoms, and even more preferably an alkylene group having 2 to 5 carbon atoms.

[0033] R 2 ~R 4 Among them, R is preferably a hydroxy group or an alkoxy group having 1 to 4 carbon atoms, more preferably an alkoxy group having 1 to 3 carbon atoms.

[0034] R 5and R 6 Among them, it is preferably H or an alkylene group having 1 to 8 carbon atoms, and more preferably H.

[0035] R 7 Among them, it is preferably an alkylene group having 1 to 12 carbon atoms, more preferably an alkylene group having 1 to 8 carbon atoms, and even more preferably an alkylene group having 2 to 6 carbon atoms.

[0036] R 8 Among them, it is preferably an alkyl group having 1 to 4 carbon atoms, and more preferably an alkyl group having 1 to 2 carbon atoms.

[0037] Among them, A is preferably H or an alkyl group having 1 to 4 carbon atoms, and more preferably H or an alkyl group having 1 to 3 carbon atoms.

[0038] Among them, n is preferably 0, 1 or 2, more preferably 0 or 1, and most preferably 0.

[0039] Among them, Q is preferably an azide group.

[0040] Most preferably as the molecular binder is 6-(3-triethoxysilylpropylamino)-1,3,5-triazine-2,4-diazide.

[0041] In the polystyrene base material of the present embodiment, the azide group in the molecular binder exists in a state converted to an amino group. That is, in the polystyrene base material, a molecular binder component having 1,3,5-triazine and an alkoxysilyl group or a silanol group derived from the molecular binder binds to the surface of the resin molded body via an amino group. Hereinafter, the component derived from the molecular binder is referred to as "molecular binder component".

[0042] In the present specification, the "amino group" is used in the sense that it also includes a group represented by -NHR (where R is other than a hydrogen atom), that is, a group corresponding to the structure obtained by removing a hydrogen atom from a primary amine.

[0043] When a compound of Chemical Formula (I) in which R 2 ~R 4 is a hydroxy group is used as the molecular bonding agent for treating the surface of the resin molded body, the molecular bonding agent component exists in the polystyrene substrate as the following Chemical Formula (II).

[0044] [Chemical Formula]

[0045] In Formula (II), the substituents of R 1 ~R 4 , E, and Q are the same substituents as those of the compound of Formula (I).

[0046] The molecular bonding agent component may exist in any form as long as it can bond the resin molded body and the metal film. For example, the component derived from the molecular bonding agent may exist without gaps over the entire surface of the resin molded body to form a film structure, may be dispersed on the surface of the resin molded body, or may exist in a sea-island shape.

[0047] The thickness of the molecular bonding agent component in the present embodiment is estimated by analyzing the nitrogen atom ratio and silicon atom ratio on the surface of the polystyrene substrate. For the surface analysis of the polystyrene substrate, X-ray Photoelectron Spectroscopy (XPS) measurement can be used. In this case, it is preferable that the nitrogen atom ratio is 5 atom% or more and the silicon atom ratio is 1 atom% or more in terms of exhibiting the bonding ability between the resin molded body of the molecular bonding agent and the metal film. In particular, it is preferable that the nitrogen atom ratio is 5 to 25 atom% and the silicon atom ratio is 1 to 5 atom%. In the present specification, the nitrogen atom ratio is intended to be the ratio of N1s, and the silicon atom ratio is intended to be the ratio of Si2p.

[0048] The elemental composition ratio of nitrogen and silicon on the surface of the polystyrene substrate can be measured using an X-ray photoelectron spectrometer (for example, JPS 9010 series, manufactured by JEOL Ltd.).

[0049] For example, when only the atoms of 6-(3-triethoxysilylpropylamino)-1,3,5-triazine-2,4-diazide are detected as an example of compound (I), the nitrogen atom ratio and silicon atom ratio determined by XPS measurement are about 28 atom% and about 5 atom%, respectively. That is, when compound 1 is used as a molecular bonding agent, when the nitrogen atom ratio on the surface of the polystyrene substrate determined by XPS measurement is 5 to 25 atom% and the silicon atom ratio is 1 to 5 atom%, it means that not only the atoms of the molecular bonding agent component but also the atoms on the surface of the resin molded body are detected. This means that the thickness of the molecular bonding agent component is 3 nm or less, which is the measurement depth of XPS measurement.

[0050] <Laminate> The laminate in the present embodiment has the above-described polystyrene substrate and a metal film that adheres to the polystyrene substrate via a molecular bonding agent component. The laminate according to the present embodiment is manufactured according to the manufacturing method of the present embodiment described later. Since the bond between the polystyrene substrate and the metal film in the laminate according to the present embodiment is strong, the peel strength is high.

[0051] In the present specification, "peel strength" means the peel strength between the resin molded body and the metal film by a 90° peel test. The 90° peel test was carried out in accordance with JIS C 6481-1996. When the peel strength of the laminate is high, there is a risk that the laminate may break when the 90° peel test is performed without applying any treatment to the laminate. Therefore, a peel test may be performed after making a cut with a width of 2 mm to 5 mm.

[0052] "The peel strength of the laminate of the present embodiment is high" means that the polystyrene substrate of one embodiment of the present invention and I 902 / I 906When a syndiotactic polystyrene substrate with I / I of 1.0 or more and [substrate] are each made into a laminate by the same process, it means that the laminate made using the polystyrene substrate of one embodiment of the present invention has a higher peel strength.

[0053] The peel strength of the laminate is also affected by the manufacturing method of the laminate. For example, depending on whether the laminate is manufactured by a hot pressing process or a plating process, the characteristics of the resulting laminate itself are different, and the peel strength of the laminate is also different. The syndiotactic polystyrene substrate of the present embodiment has a higher peel strength than a syndiotactic polystyrene substrate with I / I of 1.0 or more when the manufacturing method of the laminate is the same. 902 / I 906 than a syndiotactic polystyrene substrate with I / I of 1.0 or more.

[0054] (Metal film) Examples of the metal material for forming the metal film included in the laminate of the present embodiment include various metals and their alloys. Specific examples of the metal include Be, Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg, Al, Ge, Sn, Pb, Sb, Bi, and Nd. Among them, from the viewpoint of application to an electronic circuit board, Cu, Ni, Al, Cr, Zn, and Ag are preferably used. Cu, Ni, and Al are used as the substrate, and those in which the surface of these metals is coated with Cr or Zn are particularly preferably used.

[0055] The thickness of the metal film is preferably 36 μm or less, more preferably 25 μm or less, and even more preferably 18 μm or less.

[0056] On the other hand, from the viewpoint of obtaining sufficient peel strength, the thickness of the metal film is preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 12 μm or more.

[0057] <Manufacturing method of polystyrene substrate> The polystyrene substrate is manufactured by a manufacturing method including a step of forming a resin molded body from a material resin containing syndiotactic polystyrene as a main component, and a step of treating the surface of the resin molded body with a molecular bonding agent. The step of forming the resin molded body includes a melt extrusion step and a cooling step.

[0058] (Melt Extrusion Step) In the melt extrusion step, the material resin is supplied to an arbitrary extrusion molding machine, melted in a cylinder, and melt-extruded into an arbitrary shape using a T-die to obtain an extruded molded body. As the extrusion molding machine, a known device such as a screw extrusion molding machine may be used.

[0059] The temperature for melt-extruding the material resin may be 275 °C or higher, and more preferably 280 °C or higher. Also, the temperature for melt-extruding may be 320 °C or lower, and more preferably 300 °C or lower.

[0060] The thickness of the extruded molded body may be appropriately determined according to the purpose of use of the finally obtained polystyrene substrate. However, the smaller the thickness, the higher the cooling rate of the extruded molded body in the subsequent cooling step.

[0061] (Cooling Step) In this embodiment, the extruded molded body obtained by the melt extrusion process is cooled at a temperature equal to or lower than the cold crystallization temperature of syndiotactic polystyrene to form a resin molded body. Thereby, the crystallinity of the crystalline resin on the surface of the resin molded body can be suppressed to a low level. Although there is no particular limitation on the cooling method, examples thereof include a method of bringing the extruded molded body into contact with a liquid refrigerant or a solid refrigerant. In the cooling by bringing into contact with a liquid refrigerant or a solid refrigerant, cooling can be performed rapidly as compared with cooling by contact with a gas, and the ratio of the amorphous-rich state of the crystalline resin on the surface of the extruded molded body can be increased. On the other hand, cooling of the inside of the extruded molded body is suppressed, and the internal crystallinity is maintained at a high level. Examples of the cooling method using a solid refrigerant include a method in which the extruded molded body is drawn by nip rolls and brought into close contact with a chill roll, and the cooling is performed on the chill roll. Further, examples of the cooling method using a liquid refrigerant include a method in which the extruded molded body is cooled by bringing it into contact with water.

[0062] The cooling temperature is not particularly limited as long as it is a temperature equal to or lower than the cold crystallization temperature (Tcc) of syndiotactic polystyrene, that is, 140°C or lower. Preferably, it is 120°C or lower, more preferably 100°C or lower, and still more preferably 80°C or lower. Further, the lower limit of the cooling temperature is not particularly limited, but for example, from the viewpoint of operability such as winding of the extruded molded body, 45°C or higher is preferable, and 80°C or higher is more preferable.

[0063] In the cooling step, various conditions of the cooling step typified by conditions other than the cooling temperature, that is, the cooling time and the type of refrigerant, are not particularly limited as long as the extruded molded body can be cooled to a temperature equivalent to that of the refrigerant up to the inside, and can be set as appropriate. For example, the cooling time, roll diameter, rotation speed, etc. when using a chill roll as a solid refrigerant are not particularly limited.

[0064] The crystallinity of syndiotactic polystyrene on the surface of the extruded molded body can vary depending on the resin additives used and the conditions of melt extrusion when manufacturing the resin molded body. However, when producing an extruded molded body with the same resin and under the same conditions, the lower the crystallinity on the surface of the extruded molded body, the higher the final peel strength.

[0065] (Molecular bonding agent treatment step) In this embodiment, after the cooling step, a molecular bonding agent-containing solution containing the above-described molecular bonding agent is applied to the surface of the resin molded body and dried. Thereby, the molecular bonding agent is supplied to the surface of the resin molded body, and a polystyrene base material can be produced.

[0066] The method of applying the molecular bonding agent-containing solution is not particularly limited. For example, methods such as directly applying it to the surface of the resin molded body with a coater or the like, immersing the resin molded body in the bonding agent-containing solution, and spraying the molecular bonding agent-containing solution onto the surface of the resin molded body with a sprayer or the like can be mentioned. The number of coating times and the coating amount of the molecular bonding agent-containing solution are not particularly limited and may be determined according to the manufacturing method when manufacturing the laminate. For example, when manufacturing the laminate which is one embodiment of the present invention by an electroplating process, in order to support the catalyst in the electroless plating solution on the surface of the resin molded body, it is necessary to bond a larger amount of the molecular bonding agent component to the surface of the resin molded body compared to the hot press process. Therefore, in the electroplating process, for the purpose of improving the catalyst-supporting ability rather than enhancing the adhesive strength, the molecular bonding agent may be repeatedly applied a plurality of times.

[0067] The content of the bonding agent in the molecular bonding agent-containing solution is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and even more preferably 0.015% by mass or more. Also, the content of the bonding agent in the molecular bonding agent-containing solution is preferably 10% by mass or less, more preferably 1% by mass or less. For example, the content of the bonding agent in the molecular bonding agent-containing solution is particularly preferably 0.1% by mass.

[0068] The solvent of the molecular binder solution can be water, alcohol solvents such as ethanol, ether solvents, ketone solvents, and mixed solvents thereof.

[0069] Next, the supplied molecular binder is bonded to the resin on the surface of the resin molded body to produce a polystyrene substrate. Methods for bonding the molecular binder to the resin on the surface of the resin molded body include ultraviolet irradiation or heating. By these treatments, nitrogen molecules are desorbed from the azide group and inserted into the C-H group on the resin surface by a radical reaction. As a result, the molecular binder component is chemically bonded to the resin molded body via an amino group. Note that these treatments include treatments performed only on a part of the surface of the resin molded body. For example, a method of applying a metal mask to a part of the surface of the resin molded body and performing ultraviolet irradiation only on the selected location is also included.

[0070] When performing ultraviolet irradiation, the exposure amount (mJ / cm 2 ) of ultraviolet light can be adjusted by the illuminance (mW / cm 2 ) and the irradiation time (sec). The exposure amount is in the range where the molecular binder can cause a reaction to bond to the resin on the surface of the resin molded body, and it is desirable that the resin surface is not deteriorated by ultraviolet light. Since the molecular binder used here has a maximum absorption at 235 nm, ultraviolet light in the range of 210 to 260 nm can efficiently cause a reaction, but since the absorption edge extends to 310 nm, ultraviolet light in the range of 260 to 310 nm may also be used. The exposure amount of the irradiated ultraviolet light may be 10 mJ / cm 2 or more, and preferably 25 mJ / cm 2 or more. Also, the exposure amount of the irradiated ultraviolet light may be 1000 mJ / cm 2 or less, and preferably 200 mJ / cm 2 or less. In particular, it is preferably 50 mJ / cm 2 .

[0071] When bonding a resin molded body and a molecular bonding agent by heating, the heating temperature is not particularly limited, but it may be 100°C or higher, preferably 120°C or higher. Also, the heating temperature may be 140°C or lower, preferably 135°C or lower. The heating time may be 5 minutes or longer, preferably 10 minutes or longer. Also, the heating time may be 60 minutes or shorter, preferably 20 minutes or shorter.

[0072] <Method for manufacturing a laminate> Next, a method for manufacturing a laminate will be described. In the following, an example in which the polystyrene substrate is a sheet-shaped molded body will be used for the description, but the shape of the polystyrene substrate is not limited thereto.

[0073] (Hot press process) In the present embodiment, the polystyrene substrate and the metal film are overlapped and hot pressed to bond the polystyrene substrate and the metal film.

[0074] The temperature of the hot press may be equal to or higher than the glass transition temperature of the material resin of the resin molded body, preferably equal to or higher than the glass transition temperature + 50°C, and more preferably equal to or higher than the glass transition temperature + 80°C. In the present embodiment, since the glass transition temperature of syndiotactic polystyrene, which is the main component of the material resin, is 90°C, it is preferably performed at 140°C or higher, and more preferably at 170°C or higher.

[0075] The surface of the resin molded body has a low crystallinity due to the above-described cooling process. By applying heat within the above-described range in this state, when the metal film is pressed, the adhesion between the metal film surface and the resin molded body surface is enhanced. By enhancing the adhesion between the metal film surface and the resin molded body surface, more bonding agent comes into contact with the metal film surface, and bonding with the metal film occurs with more bonding agent. As a result, the peel strength of the laminate can be increased.

[0076] Also, the temperature of the hot press may be below the melting point of the material resin of the resin molded body, preferably below the melting point by 5°C or lower, and more preferably below the melting point by 40°C or lower. In the present embodiment, since the melting point of syndiotactic polystyrene, which is the main component of the material resin, is 275°C, it is preferably performed at 270°C or lower, and more preferably at 235°C or lower.

[0077] By setting the temperature of the hot press within the above range, it is possible to prevent the resin molded body from melting during the hot press, and a laminate excellent in dimensional stability can be obtained.

[0078] In the present embodiment, the hot press may be performed at a pressure of 3 MPa or higher, preferably at a pressure of 7 MPa or higher, and more preferably at a pressure of 10 MPa or higher. By increasing the pressure of the hot press, the adhesion between the surface of the metal film and the surface of the resin molded body increases, more adhesive comes into contact with the surface of the metal film, and bonding with the metal film occurs with more molecular adhesives. As a result, the peel strength of the laminate can be increased.

[0079] In addition, when the temperature of the hot press is lower than the Tcc temperature of syndiotactic polystyrene, a preferable molded body can be obtained even under a press condition of 3 Mpa or lower. In this case, since the surface of the resin molded body remains in an amorphous-rich state and adheres to the metal film, the bond between the surface of the resin molded body and the metal film becomes strong. On the other hand, when pressing at a temperature higher than the Tcc temperature under a press condition of 3 Mpa or lower, there is a possibility that the surface of the resin molded body crystallizes before the surface of the resin molded body and the metal film adhere. For this reason, the bond between the surface of the resin molded body and the metal film does not become strong, and a laminate with low peel strength is obtained.

[0080] There is no upper limit to the pressure of the hot press, but depending on the characteristics of the equipment used, it can be, for example, 30 MPa or lower, or 20 MPa or lower. <Manufacturing method of laminate by plating> Next, the manufacturing method of the laminate by plating will be described. The manufacturing process of the polystyrene base material described in paragraphs 0048 to 0061 is the same as the hot press process. (Plating process) In the plating process of this embodiment, the polystyrene substrate is subjected to a conductor conversion treatment by electroless (chemical) plating, and then a metal film is thickened to a predetermined thickness by electroplating. Thereafter, a mixed oxide is formed between the molecular binder and the metal film by heat treatment, thereby strongly bonding the resin molded body and the metal film.

[0081] When performing the plating process, in order to increase the catalyst loading on the surface of the resin molded body as compared with the case of performing the hot press process, it is necessary to apply a large amount of molecular binder to the surface of the resin molded body.

[0082] When performing electroless plating, catalyst loading is carried out using a metal catalyst solution. The metal catalyst solution contains, for example, halides (chlorides, bromides, and iodides) of one or more metals (for example, Sn, Pd, Cu, Ag, Au, Sn / Pd colloid, Su / Ag colloid, and Sn / Ag / Pd colloid). In addition, acids such as HCl and HNaSO4 are also included. When treating by immersion, for example, immerse at 0 to 80 °C (preferably 20 to 50 °C) for 1 to 5 minutes. If the immersion temperature is within the above range, electroless plating can be suitably performed, and the surface of the resin molded body can be kept in an amorphous-rich state. This treatment is generally known under names such as the catalyst-accelerator method or the sensitizer-activator method. Although the details of this pretreatment are omitted, it is not limited to only known techniques.

[0083] The electroless plating solution contains a metal salt and a reducing agent. Known electroless plating solutions include, for example, electroless Ni-P plating solution, electroless Ni-B plating solution, electroless Ni-P composite plating solution, electroless copper formalin solution, electroless copper glyoxylate solution, electroless palladium plating solution, and electroless cobalt plating solution, but are not limited thereto.

[0084] The metal salts contained in the electroless plating solution are, for example, metal salts such as silver, copper, gold, zinc, nickel, cobalt, iron, palladium, platinum, brass, tin, molybdenum, tungsten, permalloy, and steel. Specifically, KAu(CN)2, KAu(CN)4, Na3Au(SO3)2, Na3Au(S2O3)2, NaAuCl4, AuCN, Ag(NH3)2NO3, AgCN, AgNO3, CuSO4·5H2O, CuEDTA, NiSO4·7H2O, NiCl2, Ni(OCOCH3)2, CoSO4, CoCl2, SnCl2·7H2O, and PdCl2, etc. can be mentioned. The concentration of the metal salt is 0.001~10 mol / L (preferably, 0.01~1 mol / L).

[0085] The reducing agent is a compound having the function of reducing the metal salt to generate a metal. Specifically, KBH4, NaBH4, NaH2PO2, (CH3)2NH·BH3, NH2NH2, H2NNH2·H2O4S, H2NNH2·HCl, H2NNH2·2HCl, H2NNH2·CH3COOH, hydroxylamine salt, N,N-ethylglycine, glycol soda, glyoxylic acid, glucose, formaldehyde, and vanillin, etc. The concentration of the reducing agent is 0.001~5 mol / L (preferably, 0.01~1 mol / L).

[0086] In addition to the metal salt and the reducing agent, various additives such as a complexing agent and a pH adjuster are included. For example, additives are included from the viewpoints of the stability (pot life) of the electroless plating solution and the reduction efficiency. Specifically, basic compounds, inorganic salts, organic acid salts, citrate salts, acetate salts, borate salts, carbonate salts, ammonia hydroxide, EDTA, diaminothylene, sodium tartrate, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol (molecular weight: 200~400), thiourea, triazinethiol, and triethanolamine, etc. The concentration of the additive is 0.00001~10 mol / L (preferably, 0.0001~1 mol / L).

[0087] The electroplating solution used for electroplating contains metal salts. Examples of electroplating solutions include copper sulfate standard plating solution, copper sulfate high-speed plating solution, copper cyanide plating solution, bright copper cyanide plating solution, copper cyanide strike plating solution, pyrophosphate copper standard plating solution, pyrophosphate copper plating solution for printed circuit boards, pyrophosphate copper decorative plating solution, nickel standard plating solution, nickel Watts plating solution, bright nickel standard plating solution, nickel sulfamate plating solution, hexavalent chromium standard plating solution, trivalent chromium standard plating solution, zinc alkaline plating solution, zinc chloride plating solution, zinc cyanide plating solution, tin sulfate plating solution, tin methanesulfonate plating solution, alkaline tin plating solution, neutral tin plating solution, weakly acidic gold plating solution, strongly acidic gold plating solution, neutral gold plating solution, gold plating alkaline cyanide solution, gold plating alkaline sulfite solution, silver strike plating solution, silver cyanide plating solution, silver thiosulfate plating solution, silver succinate plating solution, platinum plating solution, rhodium plating solution, and palladium plating solution, etc. Of course, it is not limited to these.

[0088] In addition to the metal salts, the electroplating solution contains additives such as mineral acids, alkalis, leveling agents, brighteners, and inhibitors. Specifically, sulfuric acid, hydrochloric acid, boric acid, sodium cyanide, caustic potash, ammonia, potassium nitrate, potassium pyrophosphate, Rochelle salt, potassium thiocyanate, saccharin, coumarin, benzenesulfonic acid, p-toluenesulfonic acid, allylsulfonic acid, ethylene cyanohydrin, pyridinium propyl sulfonate, naphthalenesulfonic acid, 1,4-butanediol, lead compounds, sodium gluconate, oxycarboxylic acid, surfactants, ethylene glycol, diethylene glycol, triethylene glycol, and polyethylene glycol (molecular weight: 200 - 600), etc.

[0089] The temperature at which the electroplating process is carried out (bath temperature) is, for example, 20 - 100 °C (preferably 20 - 70 °C). The current density is, for example, 0.1 - 15 A / dm 2 (preferably 1 - 7 A / dm 2) If the bath temperature is within the above range, electroplating can be suitably performed, and the surface of the resin molded body can be kept in an amorphous-rich state.

[0090] In this embodiment, the heating after electroplating is not limited to the embodiment. For example, when heating is carried out in a constant-temperature dryer, it is carried out at 80 to 200 ° C for 5 to 60 minutes. When heating is carried out by hot pressing, it is carried out at 80 to 200 ° C, 1 to 10 MPa for 5 to 60 minutes. If the temperature is low, it may be carried out for a long time, and if the temperature is high, it may be carried out for a short time. For example, if it is 80 ° C, it is carried out for about 20 minutes, and if it is 150 ° C, it is carried out for about 5 minutes.

[0091] (Other treatments) Before applying the molecular bonding agent-containing solution to the surface of the resin molded body, corona treatment or the like may be performed to improve the wettability of the surface of the resin molded body. Further, in order to remove the dirt on the surface of the resin molded body, it is preferable to perform ultrasonic cleaning using ethanol or the like before applying the molecular bonding agent-containing solution to the surface of the resin molded body.

[0092] After manufacturing the laminate by a hot pressing process or a plating process, any post-treatment may be performed to improve any properties of the laminate. For example, as a post-treatment, after adhering a metal film to the resin molded body, an annealing treatment may be performed. By performing the annealing treatment, the crystallization of the crystalline resin in the resin molded body proceeds, and the mechanical strength is improved. Further, the corrosion resistance is improved by modifying the plating film.

[0093] <Summary> The polystyrene substrate according to this aspect 1 is a polystyrene substrate having adhesiveness, and the polystyrene substrate is composed of a resin molded body containing syndiotactic polystyrene as a main component, and a molecular bonding agent component derived from a molecular bonding agent having 1,3,5-triazine and an alkoxysilyl group or a silanol group is bonded to the surface of the resin molded body via an amino group, and in ATR-IR measurement, the peak intensity I at 902 cm -1 and the peak intensity I at 902 906 cm -1 and the peak intensity I at906 The intensity ratio I 902 / I 906 is less than 1.0. Such a polystyrene substrate has a surface of the resin molded body in an amorphous-rich state. Therefore, when producing a laminate by bonding with a metal film, a favorable bond with the metal film is formed.

[0094] In the polystyrene substrate according to the second aspect, in the first aspect, the molecular bonding agent is a compound represented by the following general formula (I).

[0095]

Chemical formula

[0096] (In the formula, R 1 is an alkylene group having 1 to 10 carbon atoms, and R 2 ~R 4 are each independently a hydroxy group, an alkoxy group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms, and at least one of R 2 ~R 4 is a hydroxy group or an alkoxy group having 1 to 5 carbon atoms, Q is an azide group or -NR 5 R 6 wherein R 5 and R 6 are each independently H, a hydrocarbon group having 1 to 24 carbon atoms, or -R 7 -SiR 8 n (OA) 3-n wherein R 7 is a linear divalent hydrocarbon group having 1 to 12 carbon atoms, R 8 is a linear hydrocarbon group having 1 to 4 carbon atoms, A is H or a linear hydrocarbon group having 1 to 4 carbon atoms, n is an integer of 0 to 3, and E is -NH-, -O-, -S-, or -NHCO-.) The polystyrene substrate according to the second aspect is preferable because the molecular bonding agent can strengthen the bond between the resin molded body and the metal film.

[0097] The laminate according to Embodiment 3 is a laminate having the polystyrene base material according to Embodiment 1 or Embodiment 2 and a metal film adhered to the polystyrene base material via the molecular bonding agent component. A laminate such as that of Embodiment 3 has a high peel strength between the polystyrene base material and the metal film.

[0098] The method for producing a polystyrene base material according to Embodiment 4 is the method for producing a polystyrene base material according to Embodiment 1 or Embodiment 2, and a resin containing syndiotactic polystyrene melt-extruded at 275 °C or higher as a main component is cooled by directly contacting a solid refrigerant or a liquid refrigerant at 140 °C or lower to form the resin molded body, and a step of applying the molecular bonding agent to the resin molded body and then irradiating with ultraviolet rays or heating to bond the molecular bonding agent to the surface of the resin molded body. By such a production method, a polystyrene base material in which the surface of the resin molded body is in a state rich in amorphous can be produced.

Example

[0099] 〔Example 1〕 (Production of syndiotactic polystyrene base material) Syndiotactic polystyrene pellets (manufactured by Idemitsu Kosan Co., Ltd., trade name "Zarex S105") were melt-extruded into a sheet using a screw extruder with a short axis of 50φ and a T-die with a width of 350 mm. The extruded molded body was cooled while being taken up at 2.2 m / min by nip rolls and adhered to a metal chill roll at 80 °C to obtain a sheet-shaped resin molded body with a thickness of 300 μm. When the resin molded body was subjected to ATR-IR measurement, the spectral intensity ratio of the resin molded body was I 902 / I 906 = 0.81.

[0100] A 0.1% ethanol solution of 6-(3-triethoxysilylpropylamino)-1,3,5-triazine-2,4-diazide (Iou Chemical Laboratory) was coated on the resin molded body with a bar coater so that a wet layer with a thickness of 30 μm was formed. After coating, it was dried, and ultraviolet rays were irradiated at 100 mJ / cm 2Irradiation was carried out at (240 to 270 nm) to obtain a polystyrene substrate (SPS sheet 1).

[0101] (Hot pressing process) Next, a copper foil with a thickness of 18 μm (manufactured by Mitsui Mining & Smelting Co., Ltd., trade name "TQ-M4-VSP") was overlaid on this SPS sheet 1, and hot pressing was performed for 5 minutes under the conditions of 140 °C (<Tcc) and 10 MPa using a heater plate molding machine P4054-00 (manufactured by NPa Systems Co., Ltd.) to produce a laminate.

[0102] <Analysis> (Measurement of peel strength) To measure the peel strength of the laminate, a 5 mm-wide cut was made in the laminate, and the metal film was peeled off by 1 cm. Then, in accordance with JIS C 6481, a 90° peel test was performed at 50 mm / min using an autograph (AGS-J, manufactured by Shimadzu Corporation). As a result, the peel strength of the laminate in this example was 9.5 N / cm.

[0103] (Measurement of attenuated total reflection Fourier transform infrared absorption spectrum (ATR-FTIR)) Using a spectrum 400 FT-IR / FT-NIR spectrometer manufactured by PerkinElmer, and using a diamond prism, measurements were taken in the range of 400 to 4000 cm -1 at intervals of 4 cm -1 with 8 accumulations each time. The peak intensity I -1 at 902 cm 902 and the peak intensity I -1 at 906 cm 906 of the obtained spectrum were measured, and the intensity ratio (I 902 / I 906 ) was calculated.

[0104] (Measurement of X-ray photoelectron spectroscopy (XPS)) Using a JPS-9010MC manufactured by JEOL Ltd., MgKα rays were used as the X-ray source without monochromatization. The analysis diameter was 3 mmΦ, the photoelectron extraction angle was 90°, and the pass energy was 10 eV. As a charge compensation measure, a neutralization gun was irradiated at 2 mA and 2 V, and the maximum peak of the C1s spectrum after measurement was corrected to 284.8 eV.

[0105] [Comparative Example 1] An SPS sheet 2 was obtained and a laminate was produced in the same process as in Example 1, except that the extruded molded body was molded at a chill roll temperature of 150°C to obtain a resin molded body. The same analysis as in Example 1 was performed on the SPS sheet 2 and the laminate. As a result, the spectral intensity ratio I 902 / I 906 = 1.54, and the adhesive strength of the laminate was 2.8 N / cm.

[0106] [Example 2] A laminate was obtained in the same process as in Example 1, except that the hot press was carried out at 180°C (>Tcc). The adhesive strength of the laminate was 11.2 N / cm.

[0107] [Comparative Example 2] A laminate was obtained in the same process as in Comparative Example 1, except that the hot press was carried out at 180°C (>Tcc). The adhesive strength of the laminate was 6 N / cm.

[0108] [Example 3] A resin molded body was obtained in the same manner as in Example 1. A 0.1% ethanol solution of 6-(3-triethoxysilylpropylamino)-1,3,5-triazine-2,4-diazide (Iyo Chemical Laboratory) was coated on the resin molded body with a bar coater so that a wet layer with a thickness of 30 μm was formed. After coating, it was dried, and ultraviolet rays were irradiated at 100 mJ / cm 2 (240 - 270 nm) using a metal halide lamp. This operation was repeated 3 times. After the third ultraviolet irradiation, ultrasonic cleaning was performed in ethanol for 10 minutes, and then hot air drying was carried out to obtain a polystyrene substrate (SPS sheet 3).

[0109] (Plating process) The molecularly treated SPS sheet 3 was immersed in a pre-dip solution (Rohm & Haas, CATAPREP 404) at room temperature for 1 minute, and then immersed in a catalyst solution (Rohm & Haas, CATAPOSIT 44) at 50 °C for 1 minute. After washing with water, it was immersed in an accelerator solution (Rohm & Haas, CUPOSIT Accerarator 19E) at room temperature for 3 minutes. After washing with water, it was immersed in an electroless nickel plating solution (Japan Kanizen, S-680) at 35 °C for 4 minutes, and then immersed in an electroless copper plating solution (Uemura Industry, Surcup PEA3) at 35 °C for 1.5 minutes. After washing with water and drying with warm air, heating was performed at 80 °C for 20 minutes. Thereafter, copper plating was thickened to 20 μm using a copper sulfate plating bath, and after washing with water and drying with warm air, heating was performed at 80 °C for 20 minutes.

[0110] <Analysis> (Adhesion strength) A cut with a width of 2 mm was made in the laminate, the copper foil was peeled off by 1 cm, and a 90° peel test was performed at 50 mm / min using an autograph (AGS J, Shimadzu). As a result, the peel strength was 22.1 N / cm.

[0111] (Comparative Example 3) A laminate was obtained by the same process as in Example 3 except that the SPS sheet 2 prepared in Comparative Example 1 was used. The adhesion strength was 16.8 N / cm.

[0112] (Example 4) The same process as in Example 3 was carried out except that the heat treatment during the plating process was carried out at 180 °C. The adhesion strength was 14.9 N / cm.

[0113] (Comparative Example 4) The same process as in Comparative Example 3 was carried out except that the heat treatment during the plating process was carried out at 180 °C. The adhesion strength was 11.3 N / cm.

[0114] In Examples 1 to 4 and Comparative Examples 1 to 4, the conditions of the processes for manufacturing the laminate and the results of analyzing the laminate are shown in Table 1.

[0115]

Table 1

[0116] From Table 1, the laminates produced in Examples 1 to 4 showed high peel strength compared to the laminates produced by the same process as each of Examples 1 to 4, except that the SPS sheets were changed in Comparative Examples 1 to 4.

Industrial Applicability

[0117] The present invention can be used for printed wiring boards using high-frequency signals of several GHz or more, and for multi-material technologies that combine metal and resin materials.

Claims

1. A polystyrene substrate having adhesiveness, wherein the polystyrene substrate is composed of a resin molded body containing syndiotactic polystyrene as a main component, a molecular bonding agent component derived from a molecular bonding agent having 1,3,5-triazine and an alkoxysilyl group or a silanol group is bonded to the surface of the resin molded body via an amino group, in ATR-IR measurement, at 902 cm －１ the peak intensity I ９０２ and at 906 cm －１ the peak intensity I ９０６ and the intensity ratio I ９０２ / I ９０６ is less than 1.0, Polystyrene substrate.

2. The polystyrene substrate according to claim 1, wherein the molecular bonding agent is a compound represented by the following general formula (I). 【Chemical Formula 1】 (In the formula, R １ is an alkylene group having 1 to 10 carbon atoms, and R ２ to R ４ are each independently a hydroxy group, an alkoxy group having 1 to 5 carbon atoms or an alkyl group having 1 to 5 carbon atoms, and at least one of R ２ to R ４ is a hydroxy group or an alkoxy group having 1 to 5 carbon atoms, Q is an azide group or -NR ５ R ６ and R ５ and R ６ are each independently H, a hydrocarbon group having 1 to 24 carbon atoms, or -R ７ -SiR ８ ｎ (OA) ３－ｎ and R ７ is a chain divalent hydrocarbon group having 1 to 12 carbon atoms, R ８ is a chain hydrocarbon group having 1 to 4 carbon atoms, A is H or a chain hydrocarbon group having 1 to 4 carbon atoms, n is an integer of 0 to 3, and E is -NH-, -O-, -S-, or -NHCO-. )

3. A laminate having the polystyrene substrate according to claim 1 or 2 and a metal film adhered to the polystyrene substrate via the molecular bonding agent component.

4. A step of cooling a resin containing syndiotactic polystyrene melted and extruded at 275°C or higher as a main component by directly contacting it with a solid refrigerant or a liquid refrigerant at 140°C or lower to form the resin molded body, A method for producing the polystyrene substrate according to claim 1 or 2, comprising a step of applying the molecular bonding agent to the resin molded body and then irradiating with ultraviolet rays or heating to bond the molecular bonding agent to the surface of the resin molded body.

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