WO2021039769A1 - Thermoplastic liquid crystal polymer molded body and method for producing same - Google Patents

Abstract

The present invention provides a method for producing a thermoplastic liquid crystal polymer molded body, said method being capable of modifying the surface of a portion to be bonded to have high adhesiveness and being also capable of modifying the surface to maintain the high adhesiveness even under high temperature high humidity conditions. This method for producing a thermoplastic liquid crystal polymer molded body comprises: a surface treatment step wherein at least a part of the surface of a thermoplastic liquid crystal polymer molded body is subjected to direct plasma processing at an output of 2.5 W/cm² or more for a processing time of less than 5 seconds; and a deaeration step wherein (a) the thermoplastic liquid crystal polymer molded body is dried under vacuum at a vacuum degree of 1,500 Pa or less for 30 minutes or more, and/or (b) the thermoplastic liquid crystal polymer molded body is dried by heating within the range of from 80°C to 300°C.

Description

Thermoplastic liquid crystal polymer molded product and its manufacturing method Related application

This application claims the priority of Japanese Patent Application No. 2019-156906 filed on August 29, 2019, and is cited as a part of this application by reference in its entirety.

The present invention relates to a method for producing a thermoplastic polymer (hereinafter referred to as a thermoplastic liquid crystal polymer) molded product capable of forming an optically anisotropic molten phase having excellent adhesiveness.

Thermoplastic liquid crystal polymer molded products have low 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 on 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 (low dielectric constant, low dielectric loss tangent) 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 a low dielectric property is attracting attention instead of the conventional polyimide (PI) and polyethylene terephthalate film. However, the thermoplastic liquid crystal polymer has a problem that the adhesiveness is low 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 product is used for coating, printing, adhering, vapor deposition, plating, etc. As a surface modification method, a surface treatment method for irradiating ultraviolet rays having a wavelength of 184.9 nm is disclosed.

Further, in Patent Document 3 (Patent No. 4892274), in the X-ray photoelectron spectroscopic analysis result of the surface portion of the adhered portion of the liquid crystal polymer molded body, the [-CO-bond] occupies the C (Is) peak intensity. ] 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 acidic 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 adhesive strength of the liquid crystal polymer molded product to the epoxy resin is improved.

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

However, in Patent Documents 1 and 2, the durability of the adhesiveness to the liquid crystal polymer molded product has not been evaluated.

Further, in Patent Document 3, if the sum of the peak intensities of [-CO-bond] and [-COO-bond] in the C (Is) peak intensity is 21% or more, the liquid crystal polymer molded product is covered. Cleavage of the liquid crystal polymer molecules progresses moderately on the surface of the bonding site, the reactivity of the surface is increased, and as a result, the initial adhesion can be mainly improved, and the ratio of peak strength: [-C-. It is stated that if the O-bond] / [-COO-bond] is 1.5 or less, the adhesiveness can be maintained for a long period of time and the long-term reliability of the product can be enhanced.

However, Patent Document 3 evaluates the adhesive strength after holding under high temperature and high humidity conditions, but the holding rate is not sufficient, and there is room for further improvement in long-term reliability.

Therefore, an object of the present invention is to modify the surface of the adhered portion of the thermoplastic liquid crystal polymer molded product to have high adhesiveness and to maintain high adhesiveness even under high temperature and high humidity conditions. It is to provide a method for producing a thermoplastic liquid crystal polymer molded article which is possible.

As a result of diligent studies to achieve the above object, the inventors of the present invention have applied a direct treatment method to at least a part of the surface of the thermoplastic liquid crystal polymer molded product, and the output is 2.5 W / cm ² or more. A surface treatment step (step 1) of performing plasma treatment with a treatment time of less than 5 seconds, and (a) drying the thermoplastic liquid crystal polymer molded article at a vacuum degree of 1500 Pa or less for 30 minutes or more under vacuum, and / or ( b) The thermoplastic liquid crystal polymer molded product obtained by the manufacturing method including the degassing step (step 2) of drying under heating in the range of 80 to 300 ° C. can improve the adhesiveness and is high temperature and high humidity. We have found that high adhesiveness can be maintained even under conditions, and have completed the present invention.

That is, the present invention can be configured in the following aspects.
[Aspect 1]
At least a portion of the surface of the thermoplastic liquid crystal polymer moldings, processing method is a direct method, output 2.5 W / cm ² or more (preferably 2.8W / cm ² or more, more preferably 3.0 W / cm ² Above, more preferably 3.2 W / cm ² or more), a treatment time of less than 5 seconds (preferably 4 seconds or less, more preferably 3 seconds or less), a surface treatment step of performing plasma treatment, and a thermoplastic liquid crystal polymer molded product. (A) Drying under vacuum at a degree of vacuum of 1500 Pa or less (preferably 1300 Pa or less, more preferably 1100 Pa or less) for 30 minutes or more (preferably 40 minutes or more, more preferably 50 minutes or more), and / or (b). ) Including a degassing step of drying under heating in the range of 80 to 300 ° C. (preferably in the range of 80 to 250 ° C., more preferably in the range of 80 to 200 ° C.).
A method for producing a thermoplastic liquid crystal polymer molded product.
[Aspect 2]
The method for producing a thermoplastic liquid crystal polymer molded product according to the first aspect, wherein the degassing step is performed after the surface treatment step.
[Aspect 3]
The method for producing a thermoplastic liquid crystal polymer molded product according to the method 1 or 2, wherein the thermoplastic liquid crystal polymer molded product is a film.
[Aspect 4]
The production method according to any one of aspects 1 to 3, wherein the gas species in the plasma treatment contains at least a nitrogen-containing gas and / or an oxygen-containing gas species (preferably N _{2 as a nitrogen-containing gas).} A method for producing a thermoplastic liquid crystal polymer molded product (including at least one optionally selected from _{O 2} and H ₂ O as an oxygen-containing gas).
[Aspect 5]
A method for producing a thermoplastic liquid crystal polymer molded product according to any one of aspects 1 to 4, wherein the surface treatment step is roll-to-roll treatment.
[Aspect 6]
The manufacturing method according to any one of aspects 1 to 5, further comprising at least an adhesion step of adhering an object to be adhered to an adhered portion including at least a part of the plasma-treated portion. A method for producing a thermoplastic liquid crystal polymer molded product.
[Aspect 7]
The production method according to any one of aspects 1 to 6, wherein the thermoplastic liquid crystal polymer molded product after the surface treatment step is formed.
In the X-ray photoelectron spectroscopic analysis result of the surface, the ratio of the peak area of [CO bond] to the C (1s) peak area <CO> and the ratio of the peak area of [COO bond] <COO>< The ratio of the peak area of [C = O bond] to the C (1s) peak area when CO> / <COO> is 1.5 or more (preferably 1.6 or more, more preferably 1.7 or more). The ratio of the peak area of <C = O> to [COO bond] <COO> The ratio <C = O> / <COO> is 0.10 or more (preferably 0.12 or more, more preferably 0.25 or more). , More preferably 0.40 or more).
A method for producing a thermoplastic liquid crystal polymer molded product.
[Aspect 8]
The production method according to any one of aspects 1 to 7, wherein the water content of the thermoplastic liquid crystal polymer molded product after the degassing step is 380 ppm or less (preferably 300 ppm or less, more preferably 200 ppm or less). A method for producing a thermoplastic liquid crystal polymer molded product.
[Aspect 9]
A thermoplastic liquid crystal polymer molded body in which an object to be adhered is adhered to an adhered portion, wherein the water content of the thermoplastic liquid crystal polymer molded body is 380 ppm or less (preferably 300 ppm or less, more preferably 200 ppm or less), and the subject to be adhered. In the X-ray photoelectron spectroscopic analysis result of the surface of the bonding site, the ratio of the peak area of [CO bond] to the C (1s) peak area <CO> and the ratio of the peak area of [COO bond] <COO> Ratio <CO> / <COO> is 1.5 or more (preferably 1.6 or more, more preferably 1.7 or more), and the peak of [C = O bond] with respect to the C (1s) peak area. The ratio of the area ratio <C = O> to the peak area ratio <COO> of [COO bond] <C = O> / <COO> is 0.10 or more (preferably 0.12 or more, more preferably 0). A thermoplastic liquid crystal polymer molded body of .25 or more, more preferably 0.40 or more).

In the present specification, the thermoplastic liquid crystal polymer molded product means a molded product containing at least a thermoplastic liquid crystal polymer. For example, the thermoplastic liquid crystal polymer molded product is an untreated molded product that has not been subjected to plasma treatment. In addition, the molded product (non-bonded or first thermoplastic liquid crystal polymer molded product) before being bonded to the object to be bonded is also the molded product (joined product or second thermoplastic liquid crystal polymer molded product) after being bonded to the bonded object. ) Is also included.

In the present specification, the ratio of the peak area is defined as [CO bond], [C = O bond], and [C = O bond] with respect to the total peak area of each peak of C (1s) observed according to each bond state. The ratio of the peak area of [COO bond] is calculated. In the present specification, the ratio of the peak area of [CO bond] to the total peak area of each peak of C (1s) is defined as <CO> and the peak area of each peak of C (1s). The ratio of the peak area of [C = O bond] to the total is expressed as <C = O>, and the ratio of the peak area of [COO bond] to the total peak area of each peak of C (1s) is expressed as <COO>.

It should be noted that any combination of 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 present invention.

According to the method for producing a thermoplastic liquid crystal polymer molded product according to the present invention, the surface of the adhered portion can be modified to a specific chemical bond state, and water existing inside or on the surface of the thermoplastic liquid crystal polymer molded product can be removed. Therefore, it is possible to produce a thermoplastic liquid crystal polymer molded product having not only high adhesiveness but also excellent adhesive strength maintenance under high temperature and high humidity conditions and high long-term reliability. Therefore, the thermoplastic liquid crystal polymer molded product obtained by the production method of the present invention is extremely useful as an insulator material for an electronic circuit substrate having excellent durability, for example, when a metal layer or a circuit is formed.

Further, the production method of the present invention is extremely useful industrially as it can produce a thermoplastic liquid crystal polymer molded product in which the surface of the adhered portion is modified so that high adhesiveness can be maintained even under high temperature and high humidity conditions.

[Thermoplastic liquid crystal polymer]
The thermoplastic liquid crystal polymer molded product obtained by the production method 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, the chemical composition thereof is particularly high. Although not particularly limited, for example, a thermoplastic liquid crystal polyester or a thermoplastic liquid crystal polyester amide having an amide bond introduced therein can be mentioned.

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 polyesteramides derived from the compounds classified into (1) to (4) and derivatives thereof exemplified below. Can be mentioned. However, it goes without saying that the combination of various raw material compounds has an appropriate range 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 structural units shown in Tables 5 and 6.

Among these copolymers, a copolymer 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-are particularly preferable. 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. Copolymers containing repeating units of aromatic diols and at least one aromatic dicarboxylic acid are preferred.

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

Further, in the case of the polymer 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'-dihydroxy. Selected from the group consisting of at least one aromatic diol (D) selected from the group consisting of biphenyl, 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 aromatic dicarboxylic acid (E) in the thermoplastic liquid crystal polymer is determined by the aromatic hydroxycarboxylic acid (C): the aromatic diol (D): the aromatic dicarboxylic acid (E). ) = (30 to 80) :( 35 to 10) :( 35 to 10), more preferably (C) :( D) :( E) = (35 to 75) :( 32) .5 to 12.5): may be about (32.5 to 12.5), more preferably (C) :( D) :( E) = (40 to 70) :( 30 to 15). ): It may be about (30 to 15).

The molar ratio of the repeating unit derived from 6-hydroshiki-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), in which case the molar ratio of the two aromatic diols may be (D1) / (D2) = 23/77 to 77/23, more preferably. May be 25/75 to 75/25, more preferably 30/70 to 70/30.

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

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

A preferred thermoplastic liquid crystal polymer has a melting point (hereinafter _{referred to as Tm 0} ) having, for example, a melting point in the range of 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 cooled to 50 ° C. at a rate of 10 ° C./min and again. The position of the heat absorption peak that appears after the temperature is raised 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 of 50.} It may have ~ 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. In addition, a filler may be added if necessary.

[Manufacturing method of thermoplastic liquid crystal polymer molded product (first manufacturing step)]
In the first method for producing a thermoplastic liquid crystal polymer molded product of the present invention, the treatment method is a direct method on at least a part of the surface of the thermoplastic liquid crystal polymer molded product, the output is 2.5 W / cm ² or more, and the processing time is A surface treatment step (step 1) of performing plasma treatment in less than 5 seconds, and (a) drying the thermoplastic liquid crystal polymer molded product under vacuum for 30 minutes or more at a vacuum degree of 1500 Pa or less, and / or (b) 80. The degassing step (step 2) of drying under heating in the range of about 300 ° C. is included.

<Surface treatment process (process 1)>
In general, plasma treatment includes a direct method in which a substrate to be treated is placed in a discharge space to perform plasma treatment directly, and a direct method in which a substrate to be treated is placed outside the discharge space and generated in the discharge space. There is a remote method in which the active species is sprayed onto the substrate to be treated for treatment. In the present invention, the direct method is used because it is advantageous for performing plasma treatment with a high output on the thermoplastic liquid crystal polymer molded product.

In the direct method, plasma treatment generates plasma discharge by supplying power between a pair of electrodes of a discharge parallel plate in an atmosphere in which a gas species is introduced in a vacuum or atmospheric pressure, and this is a thermoplastic liquid crystal polymer. This is carried out by irradiating at least a part of the surface of the molded body with plasma.

The surface of the thermoplastic liquid crystal polymer molded product to be plasma-treated in the present invention means the vicinity of the outermost surface (range of about 10 to 100 nm in the depth direction from the outermost surface).

In the present invention, since the output in the plasma treatment ^{is as high as 2.5 W / cm 2} or more and the treatment time is as short as less than 5 seconds, the surface of the thermoplastic liquid crystal polymer molded product can be surface-modified to a specific chemical bond state. It is possible, and the reactivity of the plasma-treated surface, that is, the adhesiveness can be improved.

Specifically, the surface of the adhered portion of the untreated thermoplastic liquid crystal polymer molded product before the plasma treatment is an ester bond (-C (= O) O-" except for the [CH bond] derived from the benzene ring or the like. [CO bond] and [COO bond] derived from C-) are considered to be the main chemical bonds, and refer to carbonyl groups for ketones and aldehydes that are not derived from ester bonds or amide bonds. ) Derived from [C = O bond] is almost or completely absent. By subjecting such an untreated thermoplastic liquid crystal polymer molded body to the plasma treatment of the present invention, the [CO bond] with respect to the total peak area of each peak of C (1s) on the surface of the adhered site. ] Peak area ratio <CO> and [COO bond] peak area ratio <COO> ratio <CO> / <COO> while increasing the peak area of each peak of C (1s) The ratio of the peak area of [C = O bond] to the total of <C = O> and the ratio of the peak area of [COO bond] to <COO> <C = O> / <COO> can be increased. ..

Output in the plasma treatment is at 2.5 W / cm ² or more, preferably 2.8W / cm ² or more, more preferably 3.0 W / cm ² or more, more preferably a at 3.2 W / cm ² or more You may. ^{The upper limit of the output in the plasma treatment is not particularly limited, but may be 8.0 W / cm 2} or less, preferably 7.5 W, for example, from the viewpoint of suppressing excessive damage to the surface of the thermoplastic liquid crystal polymer molded product. It may be / cm ² or less, more preferably 7.0 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 processing time of the plasma treatment is less than 5 seconds, but may be preferably 4 seconds or less, more preferably 3 seconds or less. The lower limit of the processing time of the plasma treatment is not particularly limited, but may be 0.1 seconds or more, preferably 0.3 seconds, for example, from the viewpoint of sufficiently modifying the surface of the thermoplastic liquid crystal polymer molded product. As mentioned above, it may be more preferably 0.5 seconds or more. The processing time of the plasma treatment refers to the time for irradiating the same portion of the thermoplastic liquid crystal polymer molded product with plasma.

Further, in the present invention, the plasma treatment may be performed on at least a part of the thermoplastic liquid crystal polymer molded product. Since the plasma treatment performed in the present invention has a long-lasting effect, the plasma treatment may be performed in consideration of the possibility of becoming a bonded portion in the future. For example, examples of the portion to be adhered in the future include a laminated portion of a cover film, a glass / epoxy material, etc., a laminated portion of a metal layer, a circuit forming portion, and the like.

In the present invention, the cumulative processing power obtained by multiplying the output of plasma processing by the processing time (the value obtained by multiplying the output per unit area by the processing time) may be 1.2 W · s / cm ² or more. Preferably 2.0W · s / cm ² or more, more preferably may be 2.5W · s / cm ² or more. The upper limit of the output in the plasma treatment is not particularly limited, but may be 30 W · s / cm ² or less, preferably 25 W · s, for example, from the viewpoint of suppressing excessive damage to the surface of the thermoplastic liquid crystal polymer molded product. It may be / cm ² or less, more preferably 20 W · s / cm ² or less.

In the present invention, in the plasma treatment, the frequency of discharging between the discharge electrodes is not particularly limited, but may be, for example, in the range of 1 kHz to 2.45 GHz, preferably 10 kHz to 100 MHz, and more preferably 30 kHz to 13. It may be 56 MHz.

The processing mode in the plasma processing may be the direct plasma mode (DP) or the reactive ion etching (RIE). In DP, the base material to be treated is installed on the ground side between the pair of electrodes, and there is an advantage that radicals can act evenly on the entire base material to be treated. On the other hand, in RIE, the base material to be treated is installed on the RF power source side between the pair of electrodes, and the ions collide with the base material to be treated while being accelerated. In the present invention, it is preferable to use DP as the treatment mode from the viewpoint of causing radicals to act evenly on the entire substrate to be treated and uniformly surface-modifying the surface.

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 as described above.

The plasma treatment may be a vacuum plasma treatment or an atmospheric pressure plasma treatment. Vacuum plasma treatment is preferable from the viewpoint of improving <CO>, <C = O> and <COO> on the surface of the adhered portion as a whole. In the case of vacuum plasma treatment, the pressure in the device to be treated is 0.1 to 20 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 product. It may be preferably 0.3 to 15 Pa, and more preferably 0.5 to 13 Pa.

The gas type used in the plasma treatment of the present invention is not particularly limited as long as the adhered portion of the thermoplastic liquid crystal polymer molded body has high adhesiveness, but the gas type includes, for example, nitrogen-containing gas, oxygen-containing gas, and Ar. noble gas such _as, like H 2, CF _4. These gas types may be used alone or in combination of two or more.
When combining gas types, for example, a plurality of nitrogen-containing gases may be combined; a plurality of oxygen-containing gases may be combined; a single or a plurality of nitrogen-containing gases and a single or a plurality of oxygen-containing gases may be combined. May be combined; oxygen-containing gas (eg O ₂ ) and CF ₄ may be combined.

Preferably, in the plasma treatment in the present invention, the gas species may contain at least a nitrogen-containing gas and / or an oxygen-containing gas species, and in particular, the gas species may contain at least a nitrogen-containing gas. Examples of the nitrogen-containing gas include N ₂ , NH _3, NO _{2, and the} like. Of these, N ₂ is preferably used. These may be used alone or in combination of two or more.

In plasma treatment containing nitrogen-containing gas or oxygen-containing gas as a gas type, among the functional groups that contribute to adhesion at the outermost surface portion (range of 5 to 10 nm in the depth direction from the outermost surface) with the lapse of time after the treatment. It is possible to improve long-term adhesiveness, probably because it is not easily affected by inversion and desorption of carbon dioxide. The mechanism is not clear, but when considered at the atomic level, it is deeper than the outermost surface (5 to 10 nm) due to plasma treatment that shortens the treatment time while increasing the output as in the present invention. Perhaps because the effect can be exhibited near the outermost surface (10 to 100 nm), while avoiding fluctuations in the functional groups at the outermost surface, there are functional groups that contribute to adhesiveness near the outermost surface. Therefore, it is considered that the influence of the decrease in adhesiveness can be reduced.

The surface of the adhered portion of the thermoplastic liquid crystal polymer molded product after the plasma treatment is <C-, even when stored at room temperature for a long period of time (for example, 2 months) without being adhered after the treatment. The specific relationships of O>, <C = O> and <COO> can be maintained with little change. For this reason, even when the product is adhered to the object to be adhered after long-term storage, the initial adhesiveness after the adhesion can be maintained in a high state.

Further, from the viewpoint of sufficiently modifying the surface of the thermoplastic liquid crystal polymer molded product, the gas type preferably _{contains N 2} as a nitrogen-containing gas and optionally contains oxygen-containing gas as another gas type. Is preferable.

Examples of the oxygen-containing gas include O ₂ , CO, CO ₂ , H ₂ O and the like. These may be used alone or in combination of two or more. Of these, O ₂ and / or H ₂ O are preferably used, and it is particularly preferable to use both _{O 2} and H _{2 O.} When both a nitrogen atom and an oxygen atom are contained as in NO _2, the gas is a nitrogen-containing gas as long as the nitrogen atom is contained.

For example, the volume ratio of the nitrogen-containing gas to the oxygen-containing gas (nitrogen-containing gas / oxygen-containing gas) may be 30/70 to 100/0, preferably 40/60 to 95/5, more preferably. May be 50/50 to 90/10.

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 10 mm. It may be preferably 4 to 9 mm, more preferably 5 to 8 mm.

In the present invention, the surface treatment step may be performed continuously or in a batch manner. In the present invention, since the processing time of the plasma treatment is short, it is preferable to perform the plasma treatment continuously from the viewpoint of productivity.

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

When a film-shaped thermoplastic liquid crystal polymer molded product (hereinafter referred to as a thermoplastic liquid crystal polymer film) is plasma-treated by roll-to-roll treatment, the film winding speed is 1 from the viewpoint of productivity and processing time. It may be about 10 m / min, preferably about 2 to 8 m / min, and more preferably about 3 to 5 m / min.

In the present invention, the thermoplastic liquid crystal polymer molded product may be formed of at least the thermoplastic liquid crystal polymer, may be formed of the thermoplastic liquid crystal polymer alone, or may be formed of the thermoplastic liquid crystal polymer and other substances. It may be composed of. The shape of the thermoplastic liquid crystal polymer molded product 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. .. Preferably, the thermoplastic liquid crystal polymer molded product may have a film-like shape, a sheet-like shape, a fibrous shape, a cloth-like shape, or the like, and is more preferably a film.

The thermoplastic liquid crystal polymer film may be an extrusion-molded film 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 a thermoplastic liquid crystal polymer film is used as a circuit board material, the thickness is preferably in the range of 20 to 150 μm, more preferably in the range of 20 to 50 μm.

<Degassing process (process 2)>
The first method for producing a thermoplastic liquid crystal polymer molded product of the present invention is (a) drying under vacuum for 30 minutes or more at a vacuum degree of 1500 Pa or less, and / or (b) heating in the range of 80 to 300 ° C. The degassing step (step 2) of drying underneath is included.
In the present invention, by performing the surface treatment step and the degassing step in combination, not only the surface can be activated, but also the moisture existing inside or on the surface of the thermoplastic liquid crystal polymer molded product can be removed. As a result, it was found that high adhesiveness can be maintained to a higher degree even under the obtained high temperature and high humidity conditions.

In the degassing step, degassing may be performed under the condition that either (a) the degassing step under vacuum or (b) the degassing step under heating is satisfied, but the above (a) and (b). ) May be degassed under the condition that both are satisfied.

The case of degassing under the condition that both (a) and (b) are satisfied is the degassing step performed under the condition that both (a) and (b) are satisfied at the same time (that is, under vacuum heating). There may be a degassing step in which the conditions (a) and (b) are separately performed on the thermoplastic liquid crystal polymer molded product, that is, in the order of (a) to (b), or from (b) to ( The degassing step may be performed separately in the order of a).

Further, in the degassing step, the first thermoplastic liquid crystal polymer molded product may be degassed alone, or may be performed in a state of being overlapped with an adhesion target described later. In that case, the overlapped heat may be obtained. Degassing may be performed while the thermoplastic liquid crystal polymer molded product and the object to be bonded are pressurized, but from the viewpoint of improving the degassing and drying property, under no pressure (under pressure release) where no pressure is substantially applied. Degassing may be performed. For example, the degassing step may be performed in a low pressure or pressure release state (for example, under a pressure of about 0 to 0.7 MPa, preferably under a pressure of about 0 to 0.5 MPa).

(A) Drying under vacuum may be performed at a vacuum degree of 1500 Pa or less, preferably 1300 Pa or less, and more preferably 1100 Pa or less. When drying under vacuum is performed independently, it may be performed at room temperature (for example, in the range of 10 to 50 ° C., preferably 15 to 45 ° C.), but it is performed under heating from the viewpoint of improving degassing efficiency. May be good. In that case, the heating temperature may be, for example, 50 to 300 ° C. (for example, 50 to 250 ° C.), preferably 80 to 250 ° C., and more preferably about 80 to 200 ° C.

(B) Drying under heating may be carried out in the range of 80 to 300 ° C., preferably in the range of 80 to 250 ° C., and more preferably in the range of 80 to 200 ° C. Further, for drying under heating, a predetermined temperature range may be set with respect to the melting point Tm of the thermoplastic liquid crystal polymer molded product. In that case, for example, heating may be performed in the range of (Tm-235) ° C. to (Tm-10) ° C. (for example, the range of (Tm-200) ° C. to (Tm-50) ° C.), preferably. Range from (Tm-225) ° C to (Tm-50) ° C (eg, range from (Tm-190) ° C to (Tm-60) ° C), more preferably (Tm-215) ° C to (Tm-70). ) ° C. (for example, the range of (Tm-180) ° C. to (Tm-70) ° C.). The melting point Tm of the thermoplastic liquid crystal polymer molded product is 10 ° C./min from room temperature to 400 ° C. by sampling a predetermined size from the thermoplastic liquid crystal polymer molded product using a differential scanning calorimeter and placing it in a sample container. The position of the endothermic peak that appears when the temperature is raised at the rate of.

By heating in a specific temperature range as described above, while suppressing sudden generation of water from the thermoplastic liquid crystal polymer molded body, in the thermoplastic liquid crystal polymer molded body (for example, in the case of a film, the inside of the film). It is possible to degas-dry the water on the surface of the film as water vapor, or to increase the kinetic energy of the air existing on the surface to degas-dry the surface of the thermoplastic liquid crystal polymer molded product.

When drying under heating is performed alone, it may be performed under a condition that does not include a vacuum degree of 1500 Pa or less. For example, it may be performed under atmospheric pressure (or normal pressure) in which the pressure is not adjusted. If necessary, heating may be performed under conditions reduced from atmospheric pressure (for example, more than 1500 Pa and less than 100,000 Pa, preferably about 3000 to 50,000 Pa).

The time required for the degassing step can be appropriately set depending on various conditions such as the state of the thermoplastic liquid crystal polymer molded product, the degree of vacuum and / or the heating temperature, and moisture and air are removed from the entire thermoplastic liquid crystal polymer molded product. For example, each degassing step (under vacuum, under heating, under vacuum heating) may be the same or different, and may be 30 minutes or more, 40 minutes or more, or 50 minutes or more, and 6 hours or less. It may be 4 hours or less, 3 hours or less, 2 hours or less, or 1.5 hours or less.
Further, the time required for the degassing step may be appropriately set in anticipation of the time when the moisture content of the thermoplastic liquid crystal polymer molded product falls within a predetermined range (for example, 380 ppm or less, 300 ppm or less, or 200 ppm or less). Good.

The degassing step may be performed on the thermoplastic liquid crystal polymer molded product prior to the surface treatment step, or may be performed after the surface treatment step, but it is preferably performed after the surface treatment step. In the surface treatment step, a carbonyl group having a higher polarity than the ester bond is introduced, and the surface becomes more hydrophilic, which may facilitate the inclusion of water. In that case, in the degassing step, water can be efficiently removed from the hydrophilic surface containing more water.

[First thermoplastic liquid crystal polymer molded product]
The first thermoplastic liquid crystal polymer molded product obtained by the production method of the present invention has at least a part to be adhered, and the C (1s) peak is found in the X-ray photoelectron spectroscopic analysis result of the surface of the adhered portion. The ratio of the peak area of [CO bond] to the area <CO> and the ratio of the peak area of [COO bond] to <COO><CO> / <COO> is 1.5 or more. And the ratio of the peak area of [C = O bond] to the C (1s) peak area <C = O> and the ratio of the peak area of [COO bond] <COO> to <C = O> / <COO> It is preferably 0.10 or more.

X-ray photoelectron spectroscopy exists on the sample surface by irradiating the sample surface with X-rays from the target metal to excite the inner-shell electrons of the atom and detect the kinetic energy of the emitted photoelectrons. This is a method for identifying elements and analyzing chemical bond states. C (1s) in this X-ray photoelectron spectroscopy is a peak obtained by photoelectrons derived from carbon atoms present on the sample surface. This peak further includes various peaks that depend on the bonding state of the carbon atom, and the position of each peak on the spectrum is determined by the bonding state.

For example, as the peak position of each bond state, [CH bond]: 285 eV, [CN bond]: 285.7 eV, [CO bond]: 286.6 eV, [C = O bond]: 287.7 eV. , [COO bond]: 289.4 eV, [OCOO bond]: 290 eV, [π-π ^* satellite peak]: 291.9 eV, and can be separated into each peak by the waveform separation mechanism attached to the device. it can. The [CO bond] peak includes both ether bond and hydroxy group peaks, and the [COO bond] peak contains both ester bond and carboxy group peaks. There is.

Regarding the peak separation method, it is preferable that the distribution function for determining the peak shape is a mixture of the Gaussian function and the Lorentz function, and the half width of each peak is as constant as possible.

In the thermoplastic liquid crystal polymer molded product obtained by the production method of the present invention, the above-mentioned plasma treatment results in an ether bond or a hydroxy group-derived [C-] with respect to the peak area of the [COO bond] derived from an ester bond or a carboxy group. Both the proportion of the peak area of the [O bond] and the proportion of the peak area of the [C = O bond] derived from the carbonyl group can be increased. In addition, by increasing the abundance ratio of [C = O bond] (carbonyl group) generated by plasma treatment and [CO bond] (hydroxy group) not derived from the ester bond, various types can be obtained on the surface of the bonded portion. Perhaps because functional groups with different types of polarity can be introduced at a specific ratio, various adhesives such as adhesives with low dielectric properties containing a non-polar skeleton as well as conventional epoxy adhesives and acrylic adhesives. It is considered that the adhesiveness of the thermoplastic liquid crystal polymer molded product to the agent can be improved.

(1) <CO> / <COO>
From the viewpoint of improving adhesiveness, the thermoplastic liquid crystal polymer molded product obtained by the production method of the present invention has a ratio of <CO> to <COO> on the surface of the adhered portion <CO> / <COO. > May be 1.5 or more, preferably 1.6 or more, and more preferably 1.7 or more. The upper limit of the ratio of the ratio of peak areas <CO> / <COO> is not particularly limited, but may be, for example, 3.0 or less.
(2) <C = O> / <COO>
Further, the ratio <C = O> / <COO> of <C = O> and <COO> on the surface of the adhered portion may be 0.10 or more, preferably 0.12 or more, more preferably 0.12 or more. May be 0.25 or more, more preferably 0.40 or more. The upper limit of the ratio of the ratio of peak areas <C = O> / <COO> is not particularly limited, but it does not excessively increase the [C = O bond] derived from the carbonyl group generated by the plasma treatment, and is thermoplastic. From the viewpoint of suppressing excessive damage to the surface of the liquid crystal polymer molded product, for example, it may be less than 1.0, preferably 0.95 or less, more preferably 0.70 or less, still more preferably 0.65 or less. There may be.

As long as the <CO> / <COO> and <C = O> / <COO> described in (1) and (2) indicate a predetermined range, <CO>, <C = O>, and The <COO> is not particularly limited.
For example, <CO> may be 12.0 to 30.0%, preferably 16.0 to 28.0%, still more preferably 18.0 to 26.0%, and even more preferably. It may be 19.0 to 25.0%.
For example, <C = O> may be 1.0 to 10.0% (for example, 1.5 to 10.0%), preferably 3.5 to 9.0%, and more preferably 4. It may be 0.0 to 8.0%, and even more preferably 4.3 to 6.5%.
For example, <COO> may be 8.0 to 15.0%, preferably 8.3 to 14.0%, still more preferably 8.5 to 13.0%, and even more preferably 9. It may be 0 to 12.0%.

(3) <CO> + <C = O> + <COO>
If necessary, the thermoplastic liquid crystal polymer molded product obtained by the production method of the present invention has <CO>, <C = O> and <COO> on the surface of the adhered portion from the viewpoint of improving adhesiveness. The sum of the above may be 25% or more, preferably 28% or more, and more preferably 30% or more. The upper limit of the sum of the peak area ratios <CO>, <C = O> and <COO> is not particularly limited, but may be, for example, 50% or less.

In the thermoplastic liquid crystal polymer molded product obtained by the production method of the present invention, the specific relationship regarding X-ray photoelectron spectroscopy may be satisfied by the portion subjected to the plasma treatment.

Since the thermoplastic liquid crystal polymer molded product obtained by the production method of the present invention has enhanced adhesiveness on the surface of the bonded portion, it is possible not only to improve the adhesiveness via various adhesives but also to adhere. Adhesiveness can also be improved by thermal pressure bonding without using an agent.

Since the thermoplastic liquid crystal polymer molded product obtained by the production method of the present invention has undergone a degassing step, the water content is reduced. From the viewpoint of maintaining high adhesiveness even under high temperature and high humidity conditions, the water content may be, for example, 380 ppm or less, preferably 300 ppm or less, and more preferably 200 ppm or less. The water content is a value measured by the method described in Examples described later.

[Manufacturing method of thermoplastic liquid crystal polymer molded product (second manufacturing process)]
The second method for producing a thermoplastic liquid crystal polymer molded body of the present invention includes a surface treatment step (step 1) of plasma-treating at least a part of the surface of the thermoplastic liquid crystal polymer molded body, and drying the thermoplastic liquid crystal polymer molded body. Degassing step (step 2) (first manufacturing step), and bonding step (step 3) (second manufacturing step) of adhering the object to be bonded to the bonded portion including at least a part of the plasma-treated portion. Step) may be provided at least.

In the bonding step, a bonding method can be selected according to the bonding target. For example, in the bonding method, the object to be bonded can be bonded to the thermoplastic liquid crystal polymer molded product by heat bonding or the like.

In thermal bonding, a step of contacting an object to be bonded with a site to be bonded including at least a part of the plasma-treated site and heating both of them is performed. As long as the temperature can be set to an appropriate temperature at which heat adhesion is possible, the heating means may be either a combustion method for burning a heat source or an electric method for electrically heating.

The bonding target used in thermal bonding is not particularly limited as long as it can be directly bonded to the bonded portion of the thermoplastic liquid crystal polymer molded product, and can be appropriately selected depending on the purpose. For example, examples of the bonding target include an adhesive (preferably an adhesive sheet) and a thermoplastic liquid crystal polymer adherend (preferably a thermoplastic liquid crystal polymer film). The above-mentioned surface treatment step and / or degassing step may be performed on the object to be bonded (for example, a thermoplastic liquid crystal polymer adherend), if necessary. The surface treatment step is preferably performed on at least the bonded portion to be bonded.

Among the thermal bonding, thermocompression bonding that applies heating and pressure is preferable. When thermocompression bonding is performed, for example, it can be performed by a method such as a general heat press, a heating roll press, or a double belt press. When thermocompression bonding, an appropriate processing temperature and pressure can be set according to the bonding target.

When the object to be bonded is an adhesive, the treatment temperature may be 130 to 250 ° C, preferably 140 to 220 ° C. The pressure during thermocompression bonding may be, for example, 0.5 to 10 MPa, preferably 1 to 8 MPa. The time for thermocompression bonding may be, for example, about 10 to 90 minutes, preferably about 15 to 75 minutes, and more preferably about 20 to 60 minutes.
When the object to be adhered is a thermoplastic liquid crystal polymer adherend (preferably a thermoplastic liquid crystal polymer film), the treatment temperature may be 180 to 350 ° C., preferably 200 to 330 ° C. The pressure at the time of thermocompression bonding may be, for example, 1 to 10 MPa, preferably 2 to 8 MPa. The time for thermocompression bonding may be, for example, about 15 to 90 minutes, preferably about 20 to 70 minutes, and more preferably about 20 to 60 minutes.

When the object to be bonded is an adhesive, a further adherend (for example, a metal layer, another sheet or film, or a circuit board) is provided with the thermoplasticity obtained in the first manufacturing step via the adhesive. It may be adhered to a liquid crystal polymer molded product (first thermoplastic liquid crystal polymer molded product). Further adhesion of the adherend may be carried out at the same time as the formation of the adhesive layer by superimposing the first thermoplastic liquid crystal polymer molded body via an adhesive. Alternatively, after forming an adhesive layer on the first thermoplastic liquid crystal polymer molded product, a further adherend may be adhered to the adhesive layer.

[Second thermoplastic liquid crystal polymer molded product]
The second thermoplastic liquid crystal polymer molded product obtained by the production method of the present invention is a thermoplastic liquid crystal polymer molded product in which the above-mentioned bonding target is adhered to the adhered portion of the first thermoplastic liquid crystal polymer molded product. is there.

The second thermoplastic liquid crystal polymer molded product obtained by the production method of the present invention may have an adhesive laminated on the adhered portion, for example, as described above in the production method. The adhesive may be a polar adhesive such as an epoxy adhesive or an acrylic adhesive, or may be a non-polar adhesive partially containing a non-polar skeleton.

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 adhesive, a cyanoacrylate adhesive, a polyurethane adhesive, an acrylic resin adhesive, etc.), and an adhesive composition in which a polymer having a non-polar skeleton as a main chain is mixed. , And 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 properties of the adhesive are that the relative permittivity (ε) at a frequency of 10 GHz is 3.3 or less and the dielectric loss tangent (tan δ) is 0.05 or less. It may be. In particular, when low dielectric properties are required for the entire substrate, an adhesive having low dielectric properties (low dielectric adhesive) is preferable. An adhesive having a low dielectric property has, for example, a relative permittivity (ε) of 3.3 or less at a frequency of 10 GHz and a dielectric loss tangent (tan δ) of 0.04 or less (preferably 0.03 or less). Good.

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 WO2016 / 031342, and examples of the modified polyamide adhesive composition containing an olefin skeleton include. Examples thereof include the adhesive described in Japanese Patent Application Laid-Open No. 2007-284515, and examples of the adhesive composition using the aromatic olefin oligomer type modifier and the epoxy resin include the adhesive described in Japanese Patent Application Laid-Open No. 2007-63306. Examples of the adhesive composition include an agent and the like, and examples of the adhesive composition containing a polyphenylene ether skeleton include the adhesive layer described in WO2014 / 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 layer laminated on the first thermoplastic liquid crystal polymer molded body (preferably the thermoplastic liquid crystal polymer film) may be an adhesive sheet, or the first thermoplastic liquid crystal polymer molded body (preferably the thermoplastic liquid crystal). A polymer film) may be 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.

In the second thermoplastic liquid crystal polymer molded product obtained by the production method of the present invention, the adhesion target may be a thermoplastic liquid crystal polymer adherend. For example, in the film-shaped thermoplastic liquid crystal polymer molded product according to the present invention, the thermoplastic liquid crystal polymer film may be laminated on the adhered portion, and the thermoplastic liquid crystal polymer molding obtained by the production method of the present invention. The body may be a laminate in which thermoplastic liquid crystal polymer films are directly laminated. 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 150 μm.

The thermoplastic liquid crystal polymer adherend to be adhered may be composed of at least the above-mentioned thermoplastic liquid crystal polymer, and may have the same components as the thermoplastic liquid crystal polymer molded body subjected to the surface treatment step and the degassing step. It may be a different component.

Further, the thermoplastic liquid crystal polymer adherend may or may not be subjected to a surface treatment step and / or a degassing step, but has improved adhesiveness (particularly, adhesion under high temperature and high humidity conditions). From the viewpoint of (maintenance of property), the above-mentioned plasma treatment is performed on at least a part of the adhered portion of the thermoplastic liquid crystal polymer adherend to the thermoplastic liquid crystal polymer molded body, and / or the thermoplastic liquid crystal polymer adherend is It is preferable that the degassing step is performed. In that case, in the thermoplastic liquid crystal polymer adherend, for example, <CO> / <COO> in the X-ray photoelectron spectroscopy analysis result is 1.5 or more, as in the case of the first thermoplastic liquid crystal polymer molded body. Moreover, <C = O> / <COO> may be 0.10 or more.

In the case of thermocompression bonding, when thermoplastic liquid crystal polymer films having the same or different components are thermocompression bonded, it is preferable to thermocompression-bond the plasma-treated surfaces of the thermoplastic liquid crystal polymer films to each other. ..

The adhesive strength between the thermoplastic liquid crystal polymer molded product and the object to be bonded may be 0.70 N / mm or more, preferably 0.75 N / mm or more, more preferably 0.80 N / mm or more, and even more preferably. It may be 1.00 N / mm or more. The upper limit is not particularly limited, but may be 3.0 N / mm or less. The adhesive strength satisfying the above range may be the adhesive strength between the thermoplastic liquid crystal polymer film and the adhesive, and preferably the adhesive strength between the thermoplastic liquid crystal polymer film and the low dielectric adhesive. Since the low-dielectric adhesive as described above contains a non-polar skeleton in order to improve the dielectric properties, the adhesiveness is lower than that of the conventional epoxy-based adhesive, but it will be shown in Examples described later. As can be seen, the adhesiveness to the thermoplastic liquid crystal polymer film obtained by the production method of the present invention is good.

The thermoplastic liquid crystal polymer molded product (particularly the thermoplastic liquid crystal polymer film) obtained by the manufacturing method of the present invention in which the objects to be bonded are laminated can maintain high adhesiveness even under high temperature and high humidity conditions. The adhesiveness is evaluated by the adhesive strength measured by the method described in Examples described later.

Under normal conditions in which the product is actually used, it is preferable that the product has a long life. Therefore, if the adhesive strength is sufficiently maintained under high temperature and high humidity conditions, it can be judged that the product life under normal conditions is long and the long-term reliability of the thermoplastic liquid crystal polymer molded product is high. Further, such a thermoplastic liquid crystal polymer molded product can maintain the adhesive strength without changing the adhesive interface even when placed in a high temperature and high humidity environment, and under high temperature and high humidity conditions. It can be judged that the durability is high. For example, the ratio of the adhesive strength when stored for 24 hours under the conditions of 23 ° C. and 50% RH to the adhesive strength when stored for 24 hours under the conditions of 121 ° C. and 100% RH is 60% or more ( For example, it may be 70% or more), preferably 80% or more, more preferably 90% or more, still more preferably 95% or more, still more preferably 98% or more. The upper limit is not particularly limited, but may be 150% or less.

In particular, in the film-shaped thermoplastic liquid crystal polymer molded product according to the present invention, the thermoplastic liquid crystal polymer itself has excellent dielectric properties and low moisture absorption, and has improved adhesiveness to adhesives and other materials. , Particularly 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, a circuit board in which a laminate or a circuit in which a metal layer is laminated on a thermoplastic liquid crystal polymer film which is the first thermoplastic liquid crystal polymer molded body is formed has adhesiveness between the thermoplastic liquid crystal polymer film and the metal layer or the circuit. It is highly reliable and preferable because it is improved.

[Conducting part forming process]
Further, in the present invention, the method for producing a thermoplastic liquid crystal polymer molded product further includes, in addition to the first manufacturing step or the second manufacturing step, a step of forming a conductive portion (for example, a metal portion or a circuit). You may. The conductive portion forming step may be performed on the untreated thermoplastic liquid crystal polymer molded product prior to the first manufacturing step, and / or may be performed in advance on the bonding target. For example, in the conductive portion forming step, the conductive portion can be formed on the thermoplastic liquid crystal polymer molded product by thermal adhesion, sputtering, vapor deposition, electroless plating, or the like.

For example, in the step of forming a conductive portion by thermal bonding, a thermoplastic liquid crystal polymer molded body (an adherend, a first thermoplastic liquid crystal polymer molded body, and / or a second thermoplastic liquid crystal polymer molded body) or an object to be bonded is subjected to. The metal portion may be formed by thermally adhering the metal. Among the thermal bonding, it is preferable to bond the metal foil by thermocompression bonding in which heating and pressure are applied. In this case, the treatment temperature may be 180 to 350 ° C., preferably 200 to 330 ° C. The pressure at the time of thermocompression bonding may be, for example, 1 to 10 MPa, preferably 2 to 8 MPa. The time for thermocompression bonding may be, for example, about 10 to 90 minutes, preferably about 15 to 75 minutes, and more preferably about 20 to 60 minutes.

In the sputtering method or the vapor deposition method, a step of bringing the metal portion into contact with the bonded portion including at least a part of the plasma-treated portion or the object to be bonded by sputtering or vapor deposition of the metal and adhering the two is performed. The sputtering method or the vapor deposition method is a known method in the field of manufacturing electronic substrates. Examples of the metal for sputtering or vapor deposition include copper, aluminum, gold, tin, chromium and the like.

In the electroless plating method, a step of adhering the two by precipitating metal from a solution containing metal ions is performed on the adhered portion including at least a part of the plasma-treated portion. The electroless plating method is a method known in the field of manufacturing plated products on non-conductive materials (plastics, ceramics, etc.), and examples of the metal include copper, nickel, cobalt, gold, tin, and chromium.

Further, the metal layer laminated by the above method may be etched to form a circuit as a conductive portion, or the circuit may be formed by directly adhering the circuit to the bonded portion.
Furthermore, for example, the circuit surface may be protected by a cover film after the circuit is formed on the thermoplastic liquid crystal polymer film, or a glass / epoxy material or another circuit board may be laminated.

The thermoplastic liquid crystal polymer molded product obtained by the production method of the present invention may further include a conductive portion. For example, the thermoplastic liquid crystal polymer molded product (first thermoplastic liquid crystal polymer molded body or second thermoplastic liquid crystal polymer molded product) according to the present invention has its surface (untreated surface that has not been plasma-treated, and untreated surface). / Or a metal portion (preferably a metal layer, more preferably a metal foil) may be provided on the plasma-treated surface), and the thermoplastic liquid crystal polymer molded product according to the present invention is adhered on the adhered portion. A metal portion may be provided on the above-mentioned bonding target.
Specifically, the film-shaped thermoplastic liquid crystal polymer molded product according to the present invention may have a metal foil laminated on the adhered portion, and the thermoplastic liquid crystal polymer molding obtained by the production method of the present invention. The body may be a laminate in which a thermoplastic liquid crystal polymer film and a metal layer are directly laminated. Further, the film-shaped thermoplastic liquid crystal polymer molded product according to the present invention may be a laminated body in which a metal layer is laminated on the above-mentioned adhesive object adhered on the adhered portion.

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 first 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 a ten-point average roughness measured with reference to JIS B 0601-1994.

Further, for example, the thermoplastic liquid crystal polymer molded product (first thermoplastic liquid crystal polymer molded product or second thermoplastic liquid crystal polymer molded product) according to the present invention has a surface (untreated surface that has not been plasma-treated). , And / or a plasma-treated surface), and the circuit may be provided on the above-mentioned bonding object that is bonded on the bonded portion.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the present Examples. In the following examples and comparative examples, various physical properties were measured by the following methods.

[<CO>, <C = O> and <COO>]
The surface of the adhered portion of the thermoplastic liquid crystal polymer film produced in Examples and Comparative Examples was measured under the following measurement conditions using a scanning X-ray photoelectron spectroscopic analyzer (“PHI Quantera SXM” manufactured by ULVAC-PHI, Inc.). <CO>, <C = O> and <COO> are measured, and the sum of the ratios of their peak areas is <CO> + <C = O> + <COO>, and the ratio of the peak areas. The ratios <CO> / <COO> and <C = O> / <COO> were calculated. The ratio of the peak area is the ratio of the peak areas of [CO bond], [C = O bond] and [COO bond] to the total peak area of each peak of C (1s) observed according to each bond state. The ratio was calculated, and the sum and ratio were calculated.
X-ray source: monochromatic AlKα (1486.6 eV)
X-ray beam diameter: 100 μmφ (25 W, 15 kV)
Measurement range: 1000 μm (horizontal) x 300 μm (vertical)
Signal capture angle: 45 °
Charge neutralization conditions: Neutralizing electron gun, Ar ⁺ ion gun Vacuum degree: 1 x ^10-6 Pa or less

[Adhesive strength]
The laminate of the thermoplastic liquid crystal polymer film and the adhesion target produced in Examples and Comparative Examples was used as an evaluation sample. After storing the evaluation sample for 24 hours under the conditions described below, a 1.0 cm wide peeling test piece was prepared from each laminate, and the film layer was fixed to a flat plate with double-sided adhesive tape according to JIS C 6471. The strength at the interface between the object to be bonded and the thermoplastic liquid crystal polymer film was measured at a speed of 50 mm / min by the 90 ° method. The adhesive strength after storage for 24 hours under the conditions of 23 ° C. and 50% RH, and the adhesive strength after storage for 24 hours under the conditions of 121 ° C. and 100% RH were measured, respectively.
As a long-term reliability evaluation under high temperature and high humidity conditions of adhesiveness, the adhesive strength was measured after storage for 24 hours under the conditions of 23 ° C. and 50% RH under the conditions of 121 ° C. and 100% RH. The ratio of the adhesive strength was calculated by measuring the adhesive strength after storage for 24 hours.

[Moisture percentage]
The Karl Fischer method (using the principle of Karl Fischer titration, absorbing water in a solvent and measuring the water content by changing the potential difference) was used as the method for measuring the water content.
1) Name of trace moisture measuring device: Mitsubishi Chemical Analytech Co., Ltd. (VA-07, CA-07)
2) Heating temperature: 260 (° C)
3) N ₂ purge pressure: 150 (ml / min)
4) Measurement preparation (automatic)
Purge 1 minute preheat 2 minutes the sample board bake Cooling 2 minutes the sample board cooling 5) Measurement titration cell entrapment time (the time for feeding water in _{N 2):} 3 minutes 6) Sample amount: 1.0 ~ 1.3 g

(Example 1)
A thermoplastic liquid crystal polymer film (manufactured by Kuraray Co., Ltd., "Vecstar", thickness 50 μm) is placed between parallel plate electrodes (electrode area) in a plasma continuous processing device in which unwinding and winding of the film are installed inside a vacuum chamber. It was set so as to pass through (5 cm × 60 cm, head-film distance 5 mm) (direct method). After exhausting the inside of the vacuum chamber with a vacuum pump, N ₂ was introduced to adjust the degree of vacuum inside the vacuum chamber to 3 Pa. The processing mode is set to the direct plasma mode (DP), the discharge frequency is 150 kHz, the power is 1 kW, and plasma is generated between the electrodes by a discharge method in which a continuous waveform voltage is applied (output 3.3 W / cm ² ) to speed the film. The surface of the thermoplastic liquid crystal polymer film was continuously plasma-treated by winding at 3 m / min (treatment time: 1.0 second). <CO>, <C = O> and <COO> calculated from the results obtained by X-ray photoelectron spectroscopy on the surface of the adhered portion of the plasma-treated thermoplastic liquid crystal polymer film, and their sum. And the ratio are shown in Table 7.

Then, the thermoplastic liquid crystal polymer film subjected to the plasma treatment was degassed and dried at 200 ° C. for 60 minutes using a hot air oven to bring the moisture content to 100 ppm, and then the thermoplastic liquid crystal polymer film was coated with a low dielectric adhesive sheet. (Made by Nikkan Kogyo Co., Ltd., "NIKAFLEX SAFY", thickness 25 μm, relative permittivity 3.0, dielectric loss tangent 0.005), and then heat-pressed at 160 ° C and 4 MPa for 40 minutes to make it thermoplastic. A laminate of a liquid crystal polymer film and an adhesive was prepared. The adhesive strength of this laminated body is shown in Table 7.

(Example 2)
Laminated in the same manner as in Example 1 except that the adhesive sheet was changed to a low-dielectric adhesive sheet (manufactured by Toagosei Co., Ltd., "AF711", thickness 25 μm, relative permittivity 2.4, dielectric loss tangent 0.003). The body was made. The adhesive strength of this laminated body is shown in Table 7.

(Comparative Example 1)
Thermoplastic liquid crystal polymer film (Kurare Co., Ltd., "Vexter", thickness 50 μm), low dielectric adhesive sheet (Nikkan Kogyo Co., Ltd., "NIKAFLEX SAFY", thickness 25 μm, relative permittivity 3.0, dielectric After stacking the dielectrics 0.005), heat pressing was performed at 160 ° C. and 4 MPa for 40 minutes to prepare a laminate of a thermoplastic liquid crystal polymer film and an adhesive. <CO>, <C = O> and <COO> calculated from the results obtained by X-ray photoelectron spectroscopy on the surface of the bonded portion of the untreated thermoplastic liquid crystal polymer film, their sum and ratio, Table 7 shows the adhesive strength of the laminate.

(Comparative Example 2)
Laminated in the same manner as in Comparative Example 1 except that the adhesive sheet was changed to a low dielectric adhesive sheet (manufactured by Toagosei Co., Ltd., "AF711", thickness 25 μm, relative permittivity 2.4, dielectric loss tangent 0.003). The body was made. The adhesive strength of this laminated body is shown in Table 7.

(Reference example 1)
A thermoplastic liquid crystal polymer film (manufactured by Kuraray Co., Ltd., "Vecstar", thickness 50 μm) is placed between parallel plate electrodes (electrode area) in a plasma continuous processing device in which unwinding and winding of the film are installed inside a vacuum chamber. It was set so as to pass through (5 cm × 60 cm, head-film distance 5 mm) (direct method). After exhausting the inside of the vacuum chamber with a vacuum pump, N ₂ was introduced to adjust the degree of vacuum inside the vacuum chamber to 3 Pa. The processing mode is set to the direct plasma mode (DP), the discharge frequency is 150 kHz, the power is 1 kW, and plasma is generated between the electrodes by a discharge method in which a continuous waveform voltage is applied (output 3.3 W / cm ² ) to speed the film. The surface of the thermoplastic liquid crystal polymer film was continuously plasma-treated by winding at 3 m / min (treatment time: 1.0 second). <CO>, <C = O> and <COO> calculated from the results obtained by X-ray photoelectron spectroscopy on the surface of the adhered portion of the plasma-treated thermoplastic liquid crystal polymer film, and their sum. And the ratio are shown in Table 7.

Then, a low-dielectric adhesive sheet (manufactured by Nikkan Kogyo Co., Ltd., "NIKAFLEX SAFY", thickness 25 μm, relative permittivity 3.0, dielectric loss tangent 0.005) was laminated on the thermoplastic liquid crystal polymer film after the plasma treatment. Above, heat pressing was performed at 160 ° C. and 4 MPa for 40 minutes to prepare a laminate of a thermoplastic liquid crystal polymer film and an adhesive. The adhesive strength of this laminated body is shown in Table 7.

(Reference example 2)
Laminated in the same manner as in Reference Example 1 except that the adhesive sheet was changed to a low-dielectric adhesive sheet (manufactured by Toagosei Co., Ltd., "AF711", thickness 25 μm, relative permittivity 2.4, dielectric loss tangent 0.003). The body was made. The adhesive strength of this laminated body is shown in Table 7.

 

As shown in Table 7, in Comparative Examples 1 and 2, since neither the surface treatment step nor the degassing step was performed, the adhesive strength after storage for 24 hours under normal conditions (23 ° C., 50 RH%) was low.

On the other hand, in Examples 1 and 2, since the specific surface treatment step and degassing step were performed, the surface of the bonded portion can be modified to a specific chemical bond state, and the water content of the thermoplastic liquid crystal polymer film can be reduced. It has a high adhesive strength after being stored for 24 hours under normal conditions. When compared with Comparative Examples 1 and 2 using the same low-dielectric adhesive sheet, Examples 1 and 2 had an adhesive strength of 2 after storage under normal conditions for 24 hours with respect to each of Comparative Examples 1 and 2. It was more than double.

Further, in Examples 1 and 2, the ratio of the adhesive strength after storage for 24 hours under normal conditions to the adhesive strength after storage for 24 hours under high temperature and high humidity conditions (121 ° C., 100% RH) is extremely high, which is 100% or more. high. Even when compared with Reference Examples 1 and 2 in which the degassing step is not performed, Examples 1 and 2 have a high temperature and high temperature because the ratio is high even though the surface of the adhered portion has the same chemical bond state. It is excellent in maintaining adhesive strength under wet conditions and can improve long-term reliability.

The thermoplastic liquid crystal polymer molded product obtained by the production method of the present invention is excellent in maintaining the long-term adhesive strength of the thermoplastic liquid crystal polymer under high temperature and high humidity conditions, and has high long-term reliability. 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 self-evident 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 (9)

1. A surface treatment process in which at least a part of the surface of the thermoplastic liquid crystal polymer molded product is treated by a direct method, the output is 2.5 W / cm ² or more, the treatment time is less than 5 seconds, and the plasma treatment is performed, and the thermoplastic liquid crystal The polymer molded article is (a) dried under vacuum at a degree of vacuum of 1500 Pa or less for 30 minutes or more, and / or (b) includes a degassing step of drying under heating in the range of 80 to 300 ° C.
   A method for producing a thermoplastic liquid crystal polymer molded product.
2. The manufacturing method according to claim 1, wherein a degassing step is performed after the surface treatment step to manufacture a thermoplastic liquid crystal polymer molded product.
3. The production method according to claim 1 or 2, wherein the thermoplastic liquid crystal polymer molded product is a film.
4. The production method according to any one of claims 1 to 3, wherein the gas type in the plasma treatment contains at least a nitrogen-containing gas and / or an oxygen-containing gas type, and the method for producing a thermoplastic liquid crystal polymer molded product.
5. A method for producing a thermoplastic liquid crystal polymer molded product, which is the production method according to any one of claims 1 to 4, wherein the surface treatment step is a roll-to-roll treatment.
6. The manufacturing method according to any one of claims 1 to 5, further comprising at least an adhesion step of adhering an object to be adhered to an adhered portion including at least a part of the plasma-treated portion. , A method for producing a thermoplastic liquid crystal polymer molded product.
7. The production method according to any one of claims 1 to 6, wherein the thermoplastic liquid crystal polymer molded product after the surface treatment step is formed.
   In the X-ray photoelectron spectroscopic analysis result of the surface, the ratio of the peak area of [CO bond] to the C (1s) peak area <CO> and the ratio of the peak area of [COO bond] <COO><COO> / <COO> is 1.5 or more, and the ratio of the peak area of [C = O bond] to the C (1s) peak area <C = O> and the ratio of the peak area of [COO bond] < It has a treated surface having a ratio <C = O> / <COO> to COO> of 0.10 or more.
   A method for producing a thermoplastic liquid crystal polymer molded product.
8. The production method according to any one of claims 1 to 7, wherein the water content of the thermoplastic liquid crystal polymer molded product after the degassing step is 380 ppm or less.
9. It is a thermoplastic liquid crystal polymer molded body in which the object to be adhered is adhered to the bonded portion, and the water content of the thermoplastic liquid crystal polymer molded body is 380 ppm or less, and in the X-ray photoelectron spectroscopic analysis result of the surface of the bonded portion , The ratio of the peak area of [CO bond] to the C (1s) peak area <CO> and the ratio of the peak area of [COO bond] <COO> to <CO> / <COO> 1.5 or more, and the ratio of the peak area of [C = O bond] to the C (1s) peak area <C = O> and the ratio of the peak area of [COO bond] <COO> <C = O A thermoplastic liquid crystal polymer molded product having a> / <COO> of 0.10 or more.