WO2021251262A1 - Thermoplastic liquid crystal polymer molded body - Google Patents

Abstract

Provided is a thermoplastic liquid crystal polymer molded body that maintains adhesiveness even after long-term storage. The thermoplastic liquid crystal polymer molded body has an adhesive area in at least a portion thereof, and a ratio (Er(S)/Er(I)) of the modulus Er(S) of the surface layer to an indentation depth of 20 nm and the modulus Er(I) of an internal layer to an indentation depth of 200 nm, as measured by nano-indentation in the adhesive area, is 0 to 1.50, inclusive.

Description

Thermoplastic liquid crystal polymer molded product Related application

This application claims the priority of Japanese Patent Application No. 2020-100180 filed on June 9, 2020, and the whole thereof is cited as a part of this application by reference.

The present invention relates to a thermoplastic liquid crystal polymer molded product having excellent adhesiveness.

Thermoplastic liquid crystal polymer molded products have excellent dielectric properties (low dielectric constant and low dielectric loss tangent) due to the properties of thermoplastic liquid crystal polymers, and are therefore attracting attention in applications where dielectric properties are important. ..

For example, in recent years, with the increase in speed of transmission signals in printed wiring boards, the frequency of signals has been increasing. Along with this, the base material used for the printed wiring board is required to have excellent dielectric properties in the high frequency region. In response to such demands, as a base film used for a printed wiring board, a thermoplastic liquid crystal polymer film having excellent dielectric properties has been attracting attention instead of the conventional polyimide (PI) and polyethylene terephthalate film. However, the thermoplastic liquid crystal polymer film has a problem of low adhesiveness in the first place.

For example, in Patent Document 1 (Japanese Patent Laid-Open No. 1-216824) and Patent Document 2 (Japanese Patent Laid-Open No. 1-236246), a liquid crystal polymer molded body is used for coating, printing, adhering, vapor deposition, plating and the like. As a surface modification method, a surface treatment method for irradiating ultraviolet rays having a wavelength of 184.9 nm is disclosed. In Patent Documents 1 and 2, when the surface of a liquid crystal polyester molded body is irradiated with ultraviolet rays having a wavelength of 184.9 nm, hydroxyl groups and oxygen-containing groups are generated to activate the surface of the molded body.

Further, in Patent Document 3 (Japanese Patent No. 4892274), in the X-ray photoelectron spectroscopy analysis result of the surface portion of the adhered portion of the liquid crystal polymer molded body, it occupies the C (Is) peak intensity [-CO-bond]. ] And [-COO-bond], the sum of the peak intensities is 21% or more, and the ratio of peak intensities [-CO-bond] / [-COO-bond] is 1.5 or less. The body is disclosed. Further, as a manufacturing method thereof, a step of irradiating at least the adhered portion of the liquid crystal polymer molded product with plasma under the conditions of ^{an output of 0.6 W / cm 2 or less and a pressure of 0.1 Torr or more in an acid gas atmosphere to perform surface treatment.} A method for producing a liquid crystal polymer molded product containing the above is described. In this document, the ratio of functional groups on the surface of the molded product is adjusted according to such plasma treatment conditions to improve the adhesive strength of the liquid crystal polymer molded product to the epoxy resin.

Japanese Unexamined Patent Publication No. 1-216824 Japanese Unexamined Patent Publication No. 1-236246 Japanese Patent No. 4892274

However, in Patent Documents 1 to 3, the surface of the thermoplastic liquid crystal polymer molded body is chemically modified. In such a surface treatment method, although the adhesiveness immediately after the treatment is imparted, the thermal motion and the surface are provided. Since the functional groups are deactivated due to contamination, there is a problem that the adhesiveness cannot be ensured after long-term storage in an unbonded state. Further, in the surface treatment methods described in Patent Documents 1 to 3, since the hydrophilic functional group is applied to the surface, the adhesiveness is poor with the adhered material having a low interaction in the chemical structure of the surface. There was a problem.

Therefore, an object of the present invention is to provide a thermoplastic liquid crystal polymer molded product that can maintain adhesiveness even after long-term storage.

As a result of diligent studies to achieve the above object, the inventors of the present invention focused on the physical properties of the surface of the thermoplastic liquid crystal polymer molded body, not the chemical structure of the surface which is easily affected by long-term storage. Then, they have found that the surface of the thermoplastic liquid crystal polymer molded product can be physically and precisely modified depending on the conditions of plasma treatment. Furthermore, as a result of repeated detailed analysis of the surface of the thermoplastic liquid crystal polymer molded product by the nanoindentation method that can analyze the physical properties of the surface in detail, the ratio of elastic modulus in the surface layer and the inner layer is specified. It has been found that in a thermoplastic liquid crystal polymer molded product satisfying the relationship, the adhesiveness can be maintained even after long-term storage.

That is, the present invention provides the following suitable forms.
[1] The elastic modulus Er (S) of the surface layer in the range of the indentation depth of 20 nm and the indentation depth of 200 nm, which have an adhesive region at least partially and are measured by the nanoindentation method in the adhesive region. The ratio of elastic modulus Er (I) of the inner layer in the range (Er (S) / Er (I)) is 0 or more (preferably 0.5 or more, more preferably 0.9 or more, still more preferably 1.0. Above, more preferably 1.1 or more) 1.50 or less (preferably 1.45 or less, more preferably 1.40 or less), a thermoplastic liquid crystal polymer molded body.
[2] The thermoplastic liquid crystal polymer molded product according to [1], wherein the elastic modulus Er (S) of the surface layer is 6.6 GPa or less (preferably 6.0 GPa or less).
[3] The thermoplastic liquid crystal polymer molded product according to [1] or [2], which has a film-like shape.
[4] The thermoplastic liquid crystal polymer molded product according to any one of [1] to [3], comprising a metal portion.
[5] The thermoplastic liquid crystal polymer molded product according to any one of [1] to [4], comprising a circuit.

In the present specification, the thermoplastic liquid crystal polymer molded body means a molded body containing at least a thermoplastic liquid crystal polymer. For example, in the thermoplastic liquid crystal polymer molded body, a molded body before being bonded to the material to be adhered ( A non-bonded body) and a molded body (bonded body or laminated body) after being bonded to the material to be bonded are also included.

It should be noted that any combination of the claims and / or at least two components disclosed in the specification is included in the present invention. In particular, any combination of two or more of the claims described in the claims is included in the invention.

According to the thermoplastic liquid crystal polymer molded product of the present invention, by controlling the elastic modulus of the inner layer and the elastic modulus of the surface layer so as to have a specific relationship, a long period of time (for example, about 1 to 6 months, preferably about 1 to 6 months) is preferable. Adhesion can be maintained even after storage (about 3 to 6 months). Therefore, the thermoplastic liquid crystal polymer molded body of the present invention is extremely useful as an insulator material for, for example, an electronic circuit board when a metal layer or a circuit is formed.

[Thermoplastic liquid crystal polymer]
The thermoplastic liquid crystal polymer molded product of the present invention is composed of a thermoplastic liquid crystal polymer. This thermoplastic liquid crystal polymer is composed of a liquid crystal polymer that can be melt-molded (or a polymer that can form an optically anisotropic molten phase), and if it is a liquid crystal polymer that can be melt-molded, its chemical composition is particularly high. Examples thereof include, but are not limited to, a thermoplastic liquid crystal polyester, or a thermoplastic liquid crystal polyester amide having an amide bond introduced therein.

Further, the thermoplastic liquid crystal polymer may be a polymer in which an imide bond, a carbonate bond, an isocyanate-derived bond such as a carbodiimide bond or an isocyanurate bond is further introduced into an aromatic polyester or an aromatic polyester amide.

Specific examples of the thermoplastic liquid crystal polymer used in the present invention include known thermoplastic liquid crystal polyesters and thermoplastic liquid crystal polyester amides derived from the compounds classified into the compounds (1) to (4) and their derivatives exemplified below. Can be mentioned. However, it goes without saying that there is an appropriate range in the combination of various raw material compounds in order to form a polymer capable of forming an optically anisotropic molten phase.

(1) Aromatic or aliphatic diols (see Table 1 for typical examples)

(2) Aromatic or aliphatic dicarboxylic acids (see Table 2 for typical examples)

(3) Aromatic hydroxycarboxylic acid (see Table 3 for typical examples)

(4) Aromatic diamine, aromatic hydroxyamine or aromatic aminocarboxylic acid (see Table 4 for typical examples).

Typical examples of thermoplastic liquid crystal polymers obtained from these raw material compounds include copolymers having repeating units shown in Tables 5 and 6.

Among these copolymers, a polymer containing p-hydroxybenzoic acid and / or 6-hydroxy-2-naphthoic acid as at least a repeating unit is preferable, and (i) p-hydroxybenzoic acid and 6-hydroxy- A copolymer containing a repeating unit with 2-naphthoic acid, or at least one aromatic hydroxycarboxylic acid selected from the group consisting of (ii) p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, and at least one. A copolymer containing a repeating unit of an aromatic diol and / or an aromatic hydroxyamine of at least one aromatic dicarboxylic acid is preferred.

For example, in the copolymer of (i), if the thermoplastic liquid crystal polymer contains at least a repeating unit of p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, the p-hydroxybenzoic acid of the repeating unit (A). The molar ratio (A) / (B) of the acid to the 6-hydroxy-2-naphthoic acid of the repeating unit (B) is (A) / (B) = 10/90 to 90 / in the thermoplastic liquid crystal polymer. It is preferably about 10, more preferably (A) / (B) = about 15/85 to 85/15, and even more preferably (A) / (B) = 20/80 to. It may be about 80/20.

Further, in the case of the copolymer of (ii), at least one aromatic hydroxycarboxylic acid (C) selected from the group consisting of p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid and 4,4'-. From the group consisting of at least one aromatic diol (D) selected from the group consisting of dihydroxybiphenyl, hydroquinone, phenylhydroquinone, and 4,4'-dihydroxydiphenyl ether, and the group consisting of terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid. The molar ratio of each repeating unit of at least one selected aromatic dicarboxylic acid (E) in the thermoplastic liquid crystal polymer is the aromatic hydroxycarboxylic acid (C): the aromatic diol (D): the aromatic dicarboxylic acid. (E) = (30 to 80): (35 to 10): may be about (35 to 10), and more preferably (C) :( D) :( E) = (35 to 75) :. (32.5 to 12.5): It may be about (32.5 to 12.5), and more preferably (C) :( D) :( E) = (40 to 70) :( 30). ~ 15): It may be about (30 ~ 15).

Further, the molar ratio of the repeating unit derived from 6-hydroxy-2-naphthoic acid in the aromatic hydroxycarboxylic acid (C) may be, for example, 85 mol% or more, preferably 90 mol% or more. It may be preferably 95 mol% or more. The molar ratio of the repeating unit derived from 2,6-naphthalenedicarboxylic acid in the aromatic dicarboxylic acid (E) may be, for example, 85 mol% or more, preferably 90 mol% or more, and more preferably 95 mol%. It may be% or more.

The aromatic diol (D) is a repeating unit derived from two different aromatic diols selected from the group consisting of hydroquinone, 4,4'-dihydroxybiphenyl, phenylhydroquinone, and 4,4'-dihydroxydiphenyl ether. It may be (D1) and (D2), and in that case, the molar ratio of the two aromatic diols may be (D1) / (D2) = 23/77 to 77/23, which is more preferable. May be 25/75 to 75/25, more preferably 30/70 to 70/30.

The molar ratio of the repeating unit derived from the aromatic diol (D) to the repeating unit derived from the aromatic dicarboxylic acid (E) is (D) / (E) = 95/100 to 100/95. Is preferable. If it deviates from this range, the degree of polymerization does not increase and the mechanical strength tends to decrease.

It should be noted that the fact that the optically anisotropic molten phase referred to in the present invention can be formed can be determined, for example, by placing the sample on a hot stage, heating the sample in a nitrogen atmosphere, and observing the transmitted light of the sample.

The thermoplastic liquid crystal polymer preferably has a melting point (hereinafter _{referred to as Tm 0} ) having a melting point in the range of, for example, 200 to 360 ° C., preferably in the range of 240 to 350 ° C., and more preferably Tm _0. The temperature is 260 to 330 ° C. The melting point of the thermoplastic liquid crystal polymer can be obtained by observing the thermal behavior of the thermoplastic liquid crystal polymer sample using a differential scanning calorimeter. That is, the thermoplastic liquid crystal polymer sample was heated from room temperature (for example, 25 ° C.) at a rate of 10 ° C./min to completely melt it, and then the melt was rapidly cooled to 50 ° C. at a rate of 10 ° C./min. The position of the endothermic peak that appears after the temperature is raised again at a rate of 10 ° C./min may be recorded as the melting point of the thermoplastic liquid crystal polymer sample.

Further, from the viewpoint of melt moldability, the thermoplastic liquid crystal polymer may have a melt viscosity of 30 to 120 Pa · s at a shear rate of 1000 / s at _{(Tm 0 + 20) ° C., preferably a melt viscosity.} It may have 50 to 100 Pa · s.

The thermoplastic liquid crystal polymer includes thermoplastic polymers such as polyethylene terephthalate, modified polyethylene terephthalate, polyolefin, polycarbonate, polyarylate, polyamide, polyphenylene sulfide, polyetheretherketone, and fluororesin, as long as the effects of the present invention are not impaired. , Various additives may be added. Further, a filler may be added as needed.

[Thermoplastic liquid crystal polymer molded product]
The thermoplastic liquid crystal polymer molded product of the present invention has an adhesive region at least in a part thereof, and the elastic modulus Er (S) of the surface layer in the range of the indentation depth of 20 nm measured by the nanoindentation method in the adhesive region. The ratio (Er (S) / Er (I)) of the elastic modulus Er (I) of the inner layer in the range of the indentation depth of 200 nm is in the range of 0 or more and 1.50 or less.

The elastic modulus Er (S) of the surface layer in the range of the indentation depth of 20 nm means that when the surface of the thermoplastic liquid crystal polymer molded product is measured by nanoindentation, the needle tip is set under the measurement conditions described in Examples described later. It is an elastic modulus calculated when the molded product is inserted from the outermost layer to a depth of 20 nm, and is defined as reflecting the state of the polar surface layer. On the other hand, the elastic modulus Er (I) of the inner layer in the range of the indentation depth of 200 nm is the elastic modulus calculated when the needle tip is inserted from the outermost layer of the molded body to a depth of 200 nm, and is Er (S). It is defined as reflecting the relatively internal state compared to. Here, the outermost layer means the peripheral surface of the contact point between the needle tip and the molded body.

The elastic moduli Er (S) and Er (I) measured by the nanoindentation method can be calculated from the stiffness S and the contact projection area Ac by using the following formula (1).

Stiffness S is calculated from the slope of the unloading curve in the load-displacement curve. The slope of the unloading curve refers to the slope of the unloading curve at the time of high displacement, that is, the slope of the unloading curve immediately after the probe is press-fitted and the start of unloading. The contact projected area Ac is a constant and correction specific to the geometry of the probe and the contact depth (difference between the predetermined press-fit depth and the surface displacement on the peripheral surface of the contact point obtained from the gradient of the unloading curve at the maximum load). It is obtained from the above term by a predetermined formula.

Generally, it is understood that the thermoplastic liquid crystal polymer molded product is inferior in adhesiveness because a highly molecularly oriented skin layer is present on the polar surface layer. In the thermoplastic liquid crystal polymer molded body of the present invention, since Er (S) / Er (I) is in a specific range, the polar surface layer easily penetrates into the unevenness of the adherend surface during thermocompression bonding, and the anchor effect is obtained. Perhaps because of the improvement, it is possible to physically improve the adhesiveness regardless of the chemical structure, and it is thought that the adhesiveness can be maintained even when stored for a long period of time. When the value of Er (S) / Er (I) is larger than 1.50, the elastic modulus of the surface layer becomes too high as compared with the inner layer of the adhesive region of the thermoplastic liquid crystal polymer molded product, and the adhesion during thermocompression bonding is performed. Insufficient power. Er (S) / Er (I) is preferably 1.45 or less, more preferably 1.40 or less. On the other hand, when the elastic modulus of the surface layer of the adhesive region of the thermoplastic liquid crystal polymer molded product is low, the molecular orientation of the surface of the molded product is disturbed and the dielectric loss tends to be high. Therefore, for example, Er (S) / Er (I). Is preferably 0.5 or more, more preferably 0.9 or more, further preferably 1.0 or more, and even more preferably 1.1 or more.

Er (S) is not particularly limited as long as Er (S) / Er (I) is 0 to 1.50, but is preferably 3.0 GPa or more, more preferably 4.0 GPa or more. It is more preferably 5.0 GPa or more. Further, it is preferably 8.0 GPa or less, more preferably 7.0 GPa or less, further preferably 6.6 GPa or less, and even more preferably 6.0 GPa or less.

Er (I) is not particularly limited as long as Er (S) / Er (I) is 0 to 1.50, but is preferably 2.0 GPa or more, more preferably 3.0 GPa or more. It is more preferably 4.0 GPa or more. Further, it is preferably 7.0 GPa or less, more preferably 6.0 GPa or less, and further preferably 4.3 GPa or less.

The thermoplastic liquid crystal polymer molded product of the present invention may be formed of at least a thermoplastic liquid crystal polymer, may be formed of the thermoplastic liquid crystal polymer alone, or may be composed of the thermoplastic liquid crystal polymer and other substances. May be.
For example, the thermoplastic liquid crystal polymer molded product of the present invention may further include a conductive portion. The conductive portion may be made of metal, for example, the thermoplastic liquid crystal polymer molded article of the present invention may have a metal portion on its surface (the surface of the bonded region and / or the surface of the non-bonded region). good. Here, the non-adhesive region means a region where Er (S) / Er (I) is not in a specific range. Specifically, the film-shaped thermoplastic liquid crystal polymer molded body (hereinafter referred to as a thermoplastic liquid crystal polymer film) according to the present invention is a metal-clad laminate (single-sided metal-clad laminate or double-sided metal) on which a metal foil is laminated. It may be a stretched laminated board). Further, the thermoplastic liquid crystal polymer molded body of the present invention may be a laminated body in which a thermoplastic liquid crystal polymer film layer and a metal layer are laminated via an adhesive layer (for example, an adhesive), or a thermoplastic liquid crystal. It may be a laminate in which a polymer film layer and a metal layer are directly laminated.

The metal can be appropriately determined according to the purpose, but copper, nickel, cobalt, aluminum, gold, tin, chromium and the like are preferably used. The thickness of the metal layer may be 0.01 to 200 μm, preferably 0.1 to 100 μm, more preferably 1 to 80 μm, and particularly preferably 2 to 50 μm.

When the metal foil is directly laminated as the metal layer, the thickness of the metal foil may be 1 to 80 μm, preferably 2 to 50 μm. Further, the surface roughness (Rz) of the metal foil on the side in contact with the thermoplastic liquid crystal polymer molded product may be, for example, 2.0 μm or less, preferably 1.5 μm or less. The lower limit of the surface roughness (Rz) may be, for example, 0.8 μm. The surface roughness (Rz) indicates the maximum height roughness measured with reference to JIS B 0601-2001.

Further, the thermoplastic liquid crystal polymer molded product of the present invention may be provided with a circuit on the surface thereof (the surface of the adhesive region and / or the surface of the non-adhesive region).

In particular, when the thermoplastic liquid crystal polymer molded body of the present invention is in the form of a film, the thermoplastic liquid crystal polymer itself has excellent dielectric properties and low moisture absorption, and has improved adhesiveness to adhesives and other materials. , Especially useful as a circuit board material (for example, an insulator of an electronic circuit board, a reinforcing plate of a flexible circuit board, a cover film of a circuit surface, etc.).
Further, in a circuit board in which a laminate (for example, a metal-clad laminate) in which a metal layer is laminated on a thermoplastic liquid crystal polymer film or a circuit is formed, the adhesiveness between the thermoplastic liquid crystal polymer film and the metal layer or the circuit is improved. Therefore, it is highly reliable and preferable.

[Manufacturing method of thermoplastic liquid crystal polymer molded product]
The method for producing a thermoplastic liquid crystal polymer molded product of the present invention includes a surface treatment step of subjecting at least a part of the surface of the thermoplastic liquid crystal polymer molded product to plasma treatment, and by adjusting the conditions of plasma treatment described later. It is possible to adjust the ratio (Er (S) / Er (I)) of the elastic modulus Er (S) of the surface layer to the elastic modulus Er (I) of the inner layer. In order to adjust the ratio of the elastic modulus of the surface layer of the surface of the thermoplastic liquid crystal polymer molded body to the elastic modulus of the inner layer, it is particularly preferable to set plasma treatment conditions such as gas type, pressure, and output. The thermoplastic liquid crystal polymer molded body to be plasma-treated is not particularly limited, and for example, at least a part of the surface of the thermoplastic liquid crystal polymer molded body is physically polished, corona discharge treated, ultraviolet irradiation treated, and uneven roughened. Thermoplastic liquid crystal polymer molding that has undergone shaping treatment such as laminating with the metal foil that has been heat-pressed and then peeling off, copper foil replica treatment that removes the copper foil by etching after laminating the copper foil, and surface treatment with a corrosive solution. The body may be subjected to plasma treatment, or the thermoplastic liquid crystal polymer molded body which has not been surface-treated may be subjected to plasma treatment.

The gas type in the plasma treatment shall be at least one selected from the group consisting of _{N 2} , Ar, H ₂ O, and CF ₄ from the viewpoint of adjusting the ratio between the elastic modulus of the surface layer and the elastic modulus of the inner layer. Is preferable. N ₂ , Ar, and H ₂ O have strong etching properties due to the ion bombard effect in the reaction during plasma treatment, and CF ₄ can be etched by generating highly reactive F radicals. When the surface of a thermoplastic liquid crystal polymer molded body is subjected to plasma treatment using these gas species, electrons, ions, and radicals collide directly with the surface, and the bonds of the thermoplastic liquid crystal polymer molecule can be selectively cleaved. It is considered that the elastic modulus of the surface layer can be lowered by making the surface finely roughened, and it is possible to adjust the relationship between the surface layer and the inner layer to a specific elastic modulus. .. On the other hand, when O ₂ is used as the gas type, it is specified in the surface layer and the inner layer by etching the entire surface, probably because it is cut regardless of the bond of the thermoplastic liquid crystal polymer molecule. It is considered that it becomes difficult to adjust to the relationship of elastic modulus of. The gas type used in the plasma treatment is more preferably _{N 2 in} that it has high roughness to the surface of the thermoplastic liquid crystal polymer molded product. Further, gas species other than the above gas species (for example, O _{2 and the} like) may be mixed and used as long as the effects of the present invention are not impaired.

Vacuum plasma treatment is preferable from the viewpoint of adjusting the ratio between the elastic modulus of the surface layer of the surface of the thermoplastic liquid crystal polymer molded body and the elastic modulus of the inner layer. As the degree of vacuum increases, the plasma generation efficiency improves, the plasma reacts with the gas, and the effect of the gas plasma etching the polymer surface increases. In the case of vacuum plasma treatment, the pressure in the device to be treated shall be 0.1 to 50 Pa from the viewpoint that the density of generated electrons and ions is within a range sufficient for surface modification of the thermoplastic liquid crystal polymer molded body. It is preferable, more preferably 0.3 to 30 Pa, still more preferably 0.5 to 15 Pa.

^{The output in the plasma treatment is preferably 3.5 W / cm 2} or more, more preferably 5.0 W, from the viewpoint of adjusting the ratio of the elastic modulus of the surface layer of the surface of the thermoplastic liquid crystal polymer molded product to the elastic modulus of the inner layer. It is / cm ² or more, more preferably 6.0 W / cm ² or more. By increasing the output in plasma treatment, more active species of gas species such as electrons, ions, and radicals can be generated, and their density and temperature can be increased, so the effect of a specific gas species is maximized. It can be demonstrated. The upper limit of the output in the plasma processing is not particularly limited, and it is preferable to perform a stronger processing. For example, from the viewpoint of suppressing excessive damage to the surface of the thermoplastic liquid crystal polymer molded product ^{, it may be 30 W / cm 2} or less, preferably 25 W / cm ² or less, and more preferably 20 W / cm ² or less.

By increasing the output in the plasma treatment, it is possible to shorten the time required for the plasma treatment of the thermoplastic liquid crystal polymer molded product. Specifically, the plasma treatment time may be 180 seconds or less, preferably 60 seconds or less, and more preferably 5 seconds or less. The lower limit of the plasma treatment time is not particularly limited, but may be 0.1 seconds or longer, preferably 0.5 seconds or longer, for example, from the viewpoint of sufficiently modifying the surface of the thermoplastic liquid crystal polymer molded product. , More preferably 1.0 second or longer. The plasma treatment time refers to the time for irradiating the same portion of the thermoplastic liquid crystal polymer molded product with plasma.

In the method for producing a thermoplastic liquid crystal polymer molded article of the present invention, the frequency of discharging between the discharge electrodes in the plasma treatment is not particularly limited, but may be, for example, in the range of 40 kHz to 2.45 GHz, which is preferable. It may be 40 kHz to 915 MHz, more preferably 110 kHz to 13.56 MHz.

Plasma processing includes (i) capacitively coupled plasma (CCP method) and (ii) inductively coupled plasma (ICP method) in which an inductively coupled plasma is applied by changing the magnetic flux using a coil. .. CCP is a generally used plasma generation method, in which a substrate to be treated is placed between a pair of electrodes, and the substrate to be treated can be treated with plasma. On the other hand, since ICP generates plasma by the fluctuating magnetic field of the induction coil, the potential difference between the electrode and the plasma does not increase, and the plasma processing is highly controllable. In addition, high frequency power supplies are generally used, and many of them have high processing capacity.
In recent years, capacitively coupled plasma (CCP), inductively coupled plasma (ICP), electron cycloton resonance plasma (ECP), helicon excited plasma (HWP), and microwave excited surface wave plasma (SWP) have been developed, and high frequencies have been developed. It is considered that the processing method corresponding to the power supply is more effective. However, in the present invention, the processing method and the power supply frequency can be selected within the range in which the relationship between the surface layer and the inner layer can be adjusted to a specific elastic modulus, and the present invention is not particularly limited.

In the method for producing the thermoplastic liquid crystal polymer molded product of the present invention, it is preferable to use (i) capacitively coupled plasma (CCP), which is a general plasma treatment method. In the examples described later, in an atmosphere in which a gas species is introduced, electric power is supplied between a pair of electrodes of the discharge parallel plate to generate plasma discharge by using CCP, and the surface of the thermoplastic liquid crystal polymer molded body is surfaced. Plasma irradiation is performed on at least a part of the battery.

The plasma processing may be a discharge method in which a voltage having a continuous waveform (AC waveform) is applied, or a discharge method in which a voltage having a pulsed waveform is applied. From the viewpoint of stabilizing the discharge, a discharge method in which a voltage having a pulsed waveform is applied is preferable. In this case, it is possible to uniformly obtain the surface modification effect even in the treatment in a short time.

Other conditions in plasma processing may be adjusted as appropriate. For example, the distance between the irradiation head of the plasma processing apparatus and the surface of the thermoplastic liquid crystal polymer molded product (for example, the distance between the head and the film) may be 3 to 50 mm. It may be preferably 4 to 30 mm, more preferably 5 to 25 mm.

In the method for producing a thermoplastic liquid crystal polymer molded product of the present invention, surface treatment may be continuously performed or may be performed in a batch manner. In order to shorten the plasma processing time, it is preferable to perform the plasma processing continuously from the viewpoint of productivity.

In particular, when the thermoplastic liquid crystal polymer molded product can be wound up, it may be continuously processed by roll-to-roll, and the plasma continuous processing apparatus in which the unwinding and winding of the molded product is installed inside. Alternatively, it is possible to use a plasma continuous processing apparatus in which the unwinding and winding of the molded product is installed externally.

When a roll-to-roll thermoplastic liquid crystal polymer molded product is plasma-treated by roll-to-roll, even if the transport speed of the molded product is about 0.1 to 10 m / min from the viewpoint of productivity and processing time. It may be preferably about 0.2 to 8.0 m / min, and more preferably 0.3 to 5.0 m / min.

The shape of the thermoplastic liquid crystal polymer molded product of the present invention is not particularly limited, and may be, for example, a shape that can be molded by cast molding of the thermoplastic liquid crystal polymer, or a shape that can be molded by injection molding or extrusion molding. May be. The thermoplastic liquid crystal polymer molded product is preferably in the form of a film, a sheet, a fiber, a cloth, or the like, and more preferably a film.

The thermoplastic liquid crystal polymer film may be obtained by extrusion molding the above-mentioned thermoplastic liquid crystal polymer. At this time, any extrusion molding method can be used, but the well-known T-die film forming stretching method, laminated body stretching method, inflation method and the like are industrially advantageous. For example, the thickness of the thermoplastic liquid crystal polymer film may be 10 to 500 μm, preferably 20 to 200 μm, and more preferably 25 to 125 μm. In particular, when the thermoplastic liquid crystal polymer film is used as an electronic circuit substrate material, the thickness is preferably in the range of 20 to 150 μm, more preferably in the range of 20 to 100 μm.

[Adhesive material]
The thermoplastic liquid crystal polymer molded product of the present invention has high adhesiveness to the material to be adhered, and can maintain the adhesiveness even after long-term storage. The material to be adhered is not particularly limited as long as it can be directly adhered to the adhesive region of the thermoplastic liquid crystal polymer molded product, and can be appropriately selected depending on the intended purpose. For example, examples of the material to be adhered include an adhesive (preferably an adhesive sheet), a thermoplastic liquid crystal polymer adherend (preferably a thermoplastic liquid crystal polymer film), and the like. The material to be adhered (for example, a thermoplastic liquid crystal polymer adherend) is also treated, if necessary, so that the elastic modulus has a specific relationship between the above-mentioned inner layer and the surface layer. May be good.

The adhesive may be a polar adhesive such as an epoxy adhesive or an acrylic adhesive, or may be a non-polar adhesive containing a non-polar skeleton in part.

Examples of the polar adhesive include a urea resin adhesive, a melamine resin adhesive, a phenol resin adhesive, a vinyl acetate resin adhesive, an isocyanate adhesive, an epoxy adhesive, and an unsaturated polyester adhesive. Examples thereof include cyanoacrylate-based adhesives, polyurethane-based adhesives, and acrylic resin-based adhesives.

Examples of the non-polar adhesive include known adhesives (for example, urea resin adhesive, melamine resin adhesive, phenol resin adhesive, vinyl acetate resin adhesive, isocyanate adhesive, epoxy adhesive). , An unsaturated polyester-based adhesive, a cyanoacrylate-based adhesive, a polyurethane-based adhesive, an acrylic resin-based adhesive, etc.) and an adhesive composition in which a polymer having a non-polar skeleton as a main chain is mixed, and the above. Examples thereof include an adhesive composition in which a non-polar skeleton is introduced into the chemical structure of the main component polymer of the adhesive.

When a thermoplastic liquid crystal polymer film is used as an electronic circuit substrate material, the dielectric property of the adhesive is preferably that the relative permittivity (ε) at a frequency of 10 GHz is 3.3 or less, and the dielectric loss tangent (tan δ) is 0. It is preferably 0.05 or less. In particular, when low dielectric properties are required for the entire substrate, an adhesive having low dielectric properties (low dielectric adhesive) is preferable. For an adhesive having a low dielectric property, for example, the relative permittivity (ε) at a frequency of 10 GHz is preferably 3.3 or less, and the dielectric loss tangent (tan δ) is preferably 0.04 or less, 0.03. The following is more preferable.

Preferred low-dielectric adhesives include, for example, an adhesive composition containing an olefin skeleton (for example, an adhesive composition containing at least a crystalline acid-modified polyolefin and an epoxy resin, and a modified polyamide adhesive composition containing an olefin skeleton. , An adhesive composition using an aromatic olefin oligomer type modifier and an epoxy resin, etc.), an adhesive composition containing a polyphenylene ether skeleton, and the like.

For example, examples of the adhesive composition containing at least a crystalline acid-modified polyolefin and an epoxy resin include the adhesive described in International Publication No. 2016/031342, and the modified polyamide adhesive composition containing an olefin skeleton. Examples thereof include the adhesive described in JP-A-2007-284515, and examples of the adhesive composition using an aromatic olefin oligomer type modifier and an epoxy resin are described in JP-A-2007-63306. Examples thereof include the described adhesives, and examples of the adhesive composition containing a polyphenylene ether skeleton include the adhesive layer described in International Publication No. 2014/046014. Among these adhesives, for example, from the viewpoint of dielectric properties, an adhesive composition containing at least a crystalline acid-modified polyolefin and an epoxy resin contains 5% by mass or more of the crystalline acid-modified polyolefin of the adhesive. Is more preferable.

The adhesive may be an adhesive sheet, or may be a thermoplastic liquid crystal polymer molded product coated with an adhesive composition and dried. The thickness of the adhesive layer may be 1 to 50 μm, preferably 5 to 40 μm, and more preferably 10 to 30 μm.

The thermoplastic liquid crystal polymer adherend may be at least composed of the above-mentioned thermoplastic liquid crystal polymer, and may have the same component as the thermoplastic liquid crystal polymer molded product, or may have a different component.

Further, the thermoplastic liquid crystal polymer adherend may or may not be surface-treated so that the elastic modulus has a specific relationship between the inner layer and the surface layer described above, but from the viewpoint of improving the adhesiveness. In at least a part of the area to be adhered to the thermoplastic liquid crystal polymer molded body in the thermoplastic liquid crystal polymer adherend, surface treatment may be performed so that the elastic modulus has a specific relationship between the above-mentioned inner layer and the surface layer. preferable. In that case, in the thermoplastic liquid crystal polymer adherend, the elastic modulus Er (S) of the surface layer and the elastic modulus Er (I) of the inner layer measured by, for example, the nanoindentation method are similarly similar to the thermoplastic liquid crystal polymer molded body. The ratio of (Er (S) / Er (I)) may be in the range of 0 to 1.50.

When the thermoplastic liquid crystal polymer films of the same component or different components are adhered, each thermoplastic liquid crystal polymer film is surface-treated so that the elastic modulus has a specific relationship between the above-mentioned inner layer and the surface layer. It is preferable that the surfaces are faced to each other and thermocompression bonded.

The adhesive strength between the thermoplastic liquid crystal polymer surface and the material to be adhered in the adhesive region of the thermoplastic liquid crystal polymer molded body may be 0.6 N / mm or more, preferably 0.7 N / mm or more, and more preferably 0. It may be 8.8 N / mm or more. The adhesive strength is evaluated by the adhesive strength measured by the method described in Examples described later.

Further, the thermoplastic liquid crystal polymer molded product of the present invention can maintain the adhesive strength even after being stored for a long period of time. For example, the ratio (storage) of the adhesive strength immediately after the above-mentioned surface treatment to the thermoplastic liquid crystal polymer molded body (adhesive strength immediately after the treatment) and the adhesive strength after storage for 6 months (adhesive strength after storage). The subsequent adhesive strength / adhesive strength immediately after the treatment) may be 70% or more, preferably 80% or more, and more preferably 90% or more.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples.
Each evaluation method of the surface-treated thermoplastic liquid crystal polymer film adopted in the following Examples and Comparative Examples is shown below.

(1) Nanoindentation measurement by SPM <Sample preparation>
The thermoplastic liquid crystal polymer film or single-sided metal-clad laminate (adhesive material) produced in Examples and Comparative Examples immediately after treatment was cut into a size of 5 mm × 5 mm, and the plasma-treated film surface was cut through a double-sided tape. It was set on a measuring pedestal as a measuring surface. Under the following equipment and measurement conditions, the elastic modulus calculated when the needle tip is inserted to a depth of 20 nm from the outermost layer of the film is calculated as Er (S), and when the needle tip is inserted to a depth of 200 nm from the outermost layer of the film. The elastic modulus was Er (I). From the load-displacement curve at the indentation depth, the elastic modulus was obtained by the analysis software attached to the following device. Further, in order to eliminate location unevenness at the measurement location, any 10 points were sampled and the average value was adopted as the analysis result.
<SPM measurement conditions>
Measuring device: Multi-functional SPM device (manufactured by Hitachi High-Tech Co., Ltd.)
Analysis software: Analysis software attached to the device Measurement temperature: 23 ° C
Measured relative humidity: 40%
Nano indentation device: Triboscope (manufactured by Heiditron)
Measuring needle shape: Diamond indenter (Berkovich type)
Measuring needle tip diameter: 150 nm
Set load:
Er (S): Push in at 10 μN for 3 seconds and pull out for 3 seconds (push depth of about 20 nm)
Er (I): Push in at 300 μN for 3 seconds and pull out for 3 seconds (push depth of about 200 nm)

(2) Adhesive strength The thermoplastic liquid crystal polymer film immediately after the treatment or the laminate of the single-sided metal-clad laminate (adhesive material) and the adhered material produced in Examples and Comparative Examples was used as an evaluation sample. As an evaluation of the adhesiveness after long-term storage, the treated adhesive material was held in a constant temperature chamber for 6 months under the conditions of temperature: 25 ° C. and humidity: 40%, and then laminated with the material to be adhered. A laminate was prepared and used as an evaluation sample.
A 1.0 cm wide peeling test piece was prepared from the laminated body of the evaluation sample, and the adhesive material side was fixed to a flat plate with double-sided adhesive tape, and 50 mm / min by the 90 ° method according to JIS C 6471: 1995. The strength (N / mm) at the interface between the adhesive material and the plasma-treated thermoplastic liquid crystal polymer film surface of the adhesive material was measured at the speed of.

[Reference Example 1]
A copolymer of p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, which is a thermoplastic liquid crystal polymer having a melting point of 280 ° C., is melt-extruded at a discharge rate of 20 kg / hour, and has a transverse stretch ratio of 4.77 times and a longitudinal relationship. An inflation film was formed under the condition of a draw ratio of 2.09 times to obtain a thermoplastic liquid crystal polymer film having an average film thickness of 50 μm. Aluminum foil is laminated on one side of the obtained film, suspended in a hot air oven, heat-treated at 310 ° C. for 10 minutes, cooled, and then the aluminum foil is dissolved and removed with an aqueous solution of ferric chloride to make it thermoplastic. A liquid crystal polymer film was obtained.

[Examples 1 to 3]
In a plasma continuous device in which the film unwinding and winding of the long thermoplastic liquid crystal polymer film obtained in Reference Example 1 is installed inside a vacuum chamber, between parallel plate electrodes (electrode area 5 cm × 60 cm, head-film). It was set so as to pass through (interval distance 20 mm). After evacuated to 2Pa by a vacuum pump to a vacuum chamber, N ₂ gas was introduced at a gas flow rate shown in Table 7 was adjusted to a pressure shown in Table 7. Subsequently, plasma was generated at the electrodes at a power output of 2 kW and a frequency of 110 kHz. The transport speed was set so that the treatment time was as shown in Table 7, and plasma treatment was continuously performed on one surface of the thermoplastic liquid crystal polymer film. The output per unit area (W / cm ² ) shown in Table 7 was calculated from the area of the electrodes and the output of the power supply.
Er (S) and Er (I) were measured by SPM on the surface of the plasma-treated thermoplastic liquid crystal polymer film. The results are shown in Table 7.
After that, two plasma-treated thermoplastic liquid crystal polymer films were cut out, and the plasma-treated surfaces of both film pieces were overlapped with each other as an adherend surface, and then pressed at 300 ° C. and 4 MPa for 10 minutes. Then, a laminate of thermoplastic liquid crystal polymer films was prepared. The adhesive strength of this laminated body was measured and used as the adhesive strength immediately after the treatment.
After storing the plasma-treated thermoplastic liquid crystal polymer film in a constant temperature chamber for 6 months (temperature 25 ° C., humidity 40%), two films were cut out and the surfaces of both film pieces subjected to plasma treatment were covered. After being laminated as a landing surface, they were pressed at 300 ° C. and 4 MPa for 10 minutes to prepare a laminate of thermoplastic liquid crystal polymer films. The adhesive strength of this laminate was measured and used as the adhesive strength after storage for 6 months.

[Example 4]
Long thermoplastic liquid crystal polymer film and long copper foil (manufactured by Fukuda Metal Foil Powder Industry Co., Ltd., "CF-H9A-DS-HD2", thickness 12 μm, surface roughness Rz 1.2 μm] obtained in Reference Example 1 ), And these were continuously introduced between the heating rolls and pressure-bonded at 270 ° C. and 3 MPa to laminate them to prepare a single-sided metal-clad laminate.
This single-sided metal-clad laminate is passed between parallel plate electrodes (electrode area 5 cm x 60 cm, head-film distance 20 mm) in a plasma continuous device in which film unwinding and winding are installed inside a vacuum chamber. I set it. After evacuated to 2Pa by a vacuum pump to a vacuum chamber, N ₂ gas was introduced at a gas flow rate shown in Table 7 was adjusted to a pressure shown in Table 7. Subsequently, plasma was generated at the electrodes at a power output of 2 kW and a frequency of 110 kHz. The transport speed was set so that the treatment time was as shown in Table 7, and plasma treatment was continuously performed on the surface of the single-sided metal-clad laminate on the thermoplastic liquid crystal polymer film side. The output per unit area (W / cm ² ) shown in Table 7 was calculated from the area of the electrodes and the output of the power supply.
Er (S) and Er (I) were measured by SPM on the surface of the plasma-treated single-sided metal-clad laminate on the thermoplastic liquid crystal polymer film side. The results are shown in Table 7.
After that, two plasma-treated single-sided metal-clad laminates were cut out, and in the two cut-out pieces of the single-sided metal-clad laminate, the surfaces on the side of the plasma-treated thermoplastic liquid crystal polymer film were laminated as adherent surfaces. After combining them, they were pressed at 300 ° C. and 4 MPa for 10 minutes to prepare a laminate in which two single-sided metal-clad laminates were laminated on each other's film surface side. The adhesive strength at the interface between the thermoplastic liquid crystal polymer film surfaces of this laminate was measured and used as the adhesive strength immediately after the treatment.
In addition, the plasma-treated single-sided metal-clad laminate was stored in a constant temperature chamber for 6 months (temperature 25 ° C., humidity 40%), then cut out into two pieces, and plasma-treated in the two cut-out pieces of the single-sided metal-clad laminate. After laminating the surfaces of the thermoplastic liquid crystal polymer film side as the adherend surface, they were pressed at 300 ° C. and 4 MPa for 10 minutes, and two single-sided metal-clad laminates were laminated on each other's film surface side. A combined laminate was produced. The adhesive strength at the interface between the thermoplastic liquid crystal polymer film surfaces of this laminate was measured and used as the adhesive strength after storage for 6 months.

[Example 5]
Long thermoplastic liquid crystal polymer film obtained in Reference Example 1, long copper foil (manufactured by Fukuda Metal Foil Powder Industry Co., Ltd., "CF-H9A-DS-HD2", thickness 12 μm, surface roughness Rz 1.2 μm ), And a long PCM foil (manufactured by JX Metal Co., Ltd., "PCM", thickness 18 μm, surface roughness Rz 4.5 μm, peelable copper foil) becomes a copper foil / thermoplastic liquid crystal polymer film / PCM foil. After laminating them by continuously pressure-bonding them between heating rolls at 270 ° C. and 3 MPa, only the PCM foil is peeled off, and the roughened surface of the PCM foil is transferred to the thermoplastic liquid crystal polymer film surface. A single-sided metal-clad laminate was obtained.
The surface of the thermoplastic liquid crystal polymer film to which this roughened surface was transferred was subjected to plasma treatment under the same conditions as in Example 4 to obtain a single-sided metal-clad laminate as an adhesive material. Er (S) and Er (I) were measured by SPM on the surface of the single-sided metal-clad laminate as an adhesive material on the side of the thermoplastic liquid crystal polymer film to which the roughened surface of the PCM foil was transferred and plasma-treated. The results are shown in Table 7.
Then, after superimposing the roughened surface treated with plasma and the plasma-treated surface of the single-sided metal-clad laminate prepared in Example 4, the two sheets were pressed at 300 ° C. and 4 MPa for 10 minutes. A laminate was prepared by laminating single-sided metal-clad laminates on the film surface side of each other. The adhesive strength at the interface between the thermoplastic liquid crystal polymer film surfaces of this laminate was measured and used as the adhesive strength immediately after the treatment.
Further, these single-sided metal-clad laminates were stored in a constant temperature chamber for 6 months (temperature 25 ° C., humidity 40%), and then the plasma-treated roughened surface and the single-sided metal-clad laminate produced in Example 4 were prepared. After superimposing the plasma-treated surface of the above, pressing was performed at 300 ° C. and 4 MPa for 10 minutes to prepare a laminate in which two single-sided metal-clad laminates were laminated on each other's film surface side. The adhesive strength at the interface between the thermoplastic liquid crystal polymer film surfaces of this laminate was measured and used as the adhesive strength after storage for 6 months.

[Example 6]
Long thermoplastic liquid crystal polymer film obtained in Reference Example 1, long copper foil (manufactured by Fukuda Metal Foil Powder Industry Co., Ltd., "CF-H9A-DS-HD2", thickness 12 μm, surface roughness Rz 1.2 μm ), And a long polyimide protective sheet are stacked so as to form a copper foil / thermoplastic liquid crystal polymer film / copper foil / polyimide protective sheet, and these are continuously introduced between the heating rolls at 300 ° C. and 3 MPa. A double-sided metal-clad laminate was prepared by crimping and laminating, and laminating a protective sheet on one side. Then, while transporting this double-sided metal-clad laminate using a shower-type etching device, one surface of the double-sided metal-clad laminate (manufactured by Sanhayato Co., Ltd.) was heated to 40 ° C. The copper foil on the non-protective surface) was etched. Then, after drying at room temperature, the protective sheet was peeled off to prepare a single-sided metal-clad laminate having a replica surface (roughened surface) of the thermoplastic liquid crystal polymer film.
The replica surface was subjected to plasma treatment under the same conditions as in Example 4 to obtain a single-sided metal-clad laminate as an adhesive material. Er (S) and Er (I) were measured by SPM on the replica surface of the plasma-treated thermoplastic liquid crystal polymer film of the single-sided metal-clad laminate as the adhesive material. The results are shown in Table 7.
Then, after superimposing the plasma-treated replica surface and the plasma-treated surface of the single-sided metal-clad laminate prepared in Example 4, press for 10 minutes at 300 ° C. and 4 MPa, and press the two single-sided surfaces. A laminate was prepared by laminating metal-clad laminates on the film surface side of each other. The adhesive strength at the interface between the thermoplastic liquid crystal polymer film surfaces of this laminate was measured and used as the adhesive strength immediately after the treatment.
Further, after storing these single-sided metal-clad laminates in a constant temperature chamber for 6 months (temperature 25 ° C., humidity 40%), the plasma-treated replica surface and the single-sided metal-clad laminate produced in Example 4 were used. After superimposing the plasma-treated surface, pressing was performed at 300 ° C. and 4 MPa for 10 minutes to prepare a laminated body in which two single-sided metal-clad laminates were laminated on each other's film surface side. The adhesive strength at the interface between the thermoplastic liquid crystal polymer film surfaces of this laminate was measured and used as the adhesive strength after storage for 6 months.

[Example 7]
As the conditions for plasma treatment, a plasma-treated single-sided metal-clad laminate was produced as an adhesive material in the same manner as in Example 4 except that the gas flow rate and pressure were changed as shown in Table 7. Er (S) and Er (I) were calculated by SPM for the surface of the plasma-treated single-sided metal-clad laminate on the thermoplastic liquid crystal polymer film side. The results are shown in Table 7.
After that, the single-sided metal-clad laminate not subjected to plasma treatment of Example 4 was prepared as a material to be adhered, and the plasma-treated surface of the single-sided metal-clad laminate and the thermoplasticity of the single-sided metal-clad laminate not subjected to plasma treatment. After superimposing the surface on the liquid crystal polymer film side, pressing was performed at 300 ° C. and 4 MPa for 10 minutes to prepare a laminate in which two single-sided metal-clad laminates were laminated on each other's film surface side. The adhesive strength at the interface between the thermoplastic liquid crystal polymer film surfaces of this laminate was measured and used as the adhesive strength immediately after the treatment.
Further, after the plasma-treated single-sided metal-clad laminate is stored in a constant temperature chamber for 6 months (temperature 25 ° C., humidity 40%), one piece is cut out and plasma-treated with the plasma-treated surface of the single-sided metal-clad laminate. After overlapping the surface of the non-single-sided metal-clad laminate on the thermoplastic liquid crystal polymer film side, press for 10 minutes at 300 ° C. and 4 MPa, and press the two single-sided metal-clad laminates on each other's film surface side. A laminated body was produced by superimposing them. The adhesive strength at the interface between the thermoplastic liquid crystal polymer film surfaces of this laminate was measured and used as the adhesive strength after storage for 6 months.

[Comparative Example 1]
As a condition of plasma treatment, a laminate of thermoplastic liquid crystal polymer films was prepared in the same manner as in Example 1 except that _{N 2} gas was introduced without exhausting with a vacuum pump and the pressure was increased, and the adhesive strength was increased. Was measured.

[Comparative Example 2]
As the conditions for plasma treatment, a laminate of thermoplastic liquid crystal polymer films was prepared in the same manner as in Example 1 except that the gas type and pressure were changed as shown in Table 7, and the adhesive strength was measured.

[Comparative Example 3]
Long thermoplastic liquid crystal polymer film obtained in Reference Example 1, long copper foil (manufactured by Fukuda Metal Foil Powder Industry Co., Ltd., "CF-H9A-DS-HD2", thickness 12 μm, surface roughness Rz 1.2 μm ), And a long PCM foil (manufactured by JX Metal Co., Ltd., "PCM", thickness 18 μm, surface roughness Rz 4.5 μm, peelable copper foil) becomes a copper foil / thermoplastic liquid crystal polymer film / PCM foil. After laminating them by continuously pressure-bonding them between heating rolls at 270 ° C. and 3 MPa, only the PCM foil is peeled off, and the roughened surface of the PCM foil is transferred to the thermoplastic liquid crystal polymer film surface. A single-sided metal-clad laminate was obtained.
Er (S) and Er (I) were measured by SPM on the surface of the single-sided metal-clad laminate on the thermoplastic liquid crystal polymer film side to which the roughened surface of the PCM foil was transferred. The results are shown in Table 7.
After that, the above-mentioned single-sided metal-clad laminate to which the roughened surface of the PCM foil was transferred and the thermoplastic liquid crystal polymer film obtained in Reference Example 1 without surface treatment were prepared, and the roughened surface of the single-sided metal-clad laminate was prepared. And a thermoplastic liquid crystal polymer film are laminated and pressed at 300 ° C. and 4 MPa for 10 minutes to prepare a laminate in which the film surface of the single-sided metal-clad laminate and the thermoplastic liquid crystal polymer film are laminated. did. The adhesive strength at the interface between the thermoplastic liquid crystal polymer film surfaces of this laminate was measured and used as the adhesive strength immediately after the treatment.
Further, the single-sided metal-clad laminate on which the roughened surface of the PCM foil was transferred and the thermoplastic liquid crystal polymer film obtained in Reference Example 1 without surface treatment were stored in a constant temperature chamber for 6 months (temperature 25 ° C.). , Humidity 40%), the roughened surface of the single-sided metal-clad laminate and the thermoplastic liquid crystal polymer film are laminated, and then pressed at 300 ° C. and 4 MPa for 10 minutes to obtain the single-sided metal-clad laminate. A laminate was prepared by superimposing a film surface and a thermoplastic liquid crystal polymer film. The adhesive strength at the interface between the thermoplastic liquid crystal polymer film surfaces of this laminate was measured and used as the adhesive strength after storage for 6 months.

[Comparative Example 4]
Er (S) and Er (I) were measured by SPM on the surface of the thermoplastic liquid crystal polymer film obtained in Reference Example 1 which had not been surface-treated. The results are shown in Table 7.
After that, two sheets of the above-mentioned thermoplastic liquid crystal polymer film which had not been surface-treated were cut out, both film pieces were overlapped, and then pressed at 300 ° C. and 4 MPa for 10 minutes to laminate the thermoplastic liquid crystal polymer films together. The body was made. The adhesive strength of this laminated body was measured and used as the adhesive strength immediately after the treatment.
Further, after storing the above-mentioned thermoplastic liquid crystal polymer film which has not been surface-treated in a constant temperature chamber for 6 months (temperature 25 ° C., humidity 40%), two films are cut out, and both film pieces are overlapped with each other. , 300 ° C., 4 MPa for 10 minutes to prepare a laminate of thermoplastic liquid crystal polymer films. The adhesive strength of this laminate was measured and used as the adhesive strength after storage for 6 months.

As shown in Table 7, the ratio (Er (S) / Er (I)) of the elastic modulus Er (S) of the surface layer to the elastic modulus Er (I) of the inner layer is in the range of 0 to 1.50. It can be seen that in Examples 1 to 7 using the plastic liquid crystal polymer molded product, the adhesive strength is high even after storage for 6 months, and high adhesiveness can be maintained even after long-term storage.

On the other hand, a thermoplastic liquid crystal polymer molded body in which the ratio (Er (S) / Er (I)) of the elastic modulus Er (S) of the surface layer to the elastic modulus Er (I) of the inner layer is out of the range of 0 to 1.50. In Comparative Examples 1 to 4 used, it was found that the adhesive strength was low, the adhesive strength after 6 months of storage decreased, and the adhesive strength could not be maintained after long-term storage.

According to the present invention, if the thermoplastic liquid crystal polymer molded body has a structure in which the elastic modulus of the inner layer and the elastic modulus of the surface layer have a specific relationship, the adhesiveness can be maintained even if it is stored for a long period of time. Therefore, it can be used for various purposes according to its shape, especially as a multilayer circuit board, an insulator of an electronic circuit board, a reinforcing plate of a flexible circuit board, a cover film on a circuit surface, a multilayer circuit using an adhesive, and the like. It is useful.

As described above, a preferred embodiment of the present invention has been described, but those skilled in the art will easily assume various changes and modifications within a trivial range by looking at the present specification.
Therefore, such changes and amendments are construed as being within the scope of the invention as defined by the claims.

Claims (5)

1. The elastic modulus Er (S) of the surface layer in the range of the indentation depth of 20 nm and the inside in the indentation depth of 200 nm, which have an adhesive region at least in a part and are measured by the nanoindentation method in the adhesive region. A thermoplastic liquid crystal polymer molded body having a layer elastic modulus Er (I) ratio (Er (S) / Er (I)) of 0 or more and 1.50 or less.
2. The thermoplastic liquid crystal polymer molded product according to claim 1, wherein the elastic modulus Er (S) of the surface layer is 6.6 GPa or less.
3. The thermoplastic liquid crystal polymer molded product according to claim 1 or 2, which has a film-like shape.
4. The thermoplastic liquid crystal polymer molded body according to any one of claims 1 to 3, further comprising a metal portion.
5. The thermoplastic liquid crystal polymer molded body according to any one of claims 1 to 4, further comprising a circuit.