TWI793415B - Thermoplastic liquid crystal polymer film, multi-layered body and shaped article, and production methods thereof - Google Patents

Abstract

Provided are a thermoplastic liquid crystal polymer film, a multi-layered body, and a shaped article, the film having a wide process window for multilayering during production of a wiring board and being excellent in heat resistance and productivity. The thermoplastic liquid crystal polymer is formed from a thermoplastic liquid crystal polymer capable of forming an optically anisotropic melt phase, and diffraction profile of a polymer section of the film detected by wide-angle x-ray diffractometry satisfies the formula, 0≤UC≤2.0 (1), where UC is a value calculated as UC = B/A ×100, where A is an integrated intensity of the profile on the base line in the range of 2θ=14^o to 26^o , B is an integrated intensity of a sub-peak profile in the rage of 2θ=22.3^o to 24.3^o , after extracting a main peak profile by approximating the main peak profile to a linear function.

Description

Thermoplastic liquid crystal polymer film, laminate, and molded article, and their production methods

The present invention relates to a film, a laminate, and a molded article having excellent heat resistance, including a polymer capable of forming an optically anisotropic melt phase (hereinafter referred to as a thermoplastic liquid crystal polymer), and methods for producing the same.

In recent years, in the fields of electronics/electricity/communication industries, the need for higher densification of printed circuit boards has been increasing due to demands for miniaturization and weight reduction of equipment. Along with this, various methods such as multilayering of circuit boards, narrowing of wiring pitches, and miniaturization of via holes are being developed. For example, a high-density circuit is produced by multilayering a metal-clad laminate including a non-metal layer and a metal layer via a non-metal layer. In the past, printed circuit boards/circuits were mainly produced by using thermosetting resins such as phenol resins and epoxy resins as non-metallic layers, and laminating them with metal layers such as copper foil. However, it is known that thermosetting resins require time until they can be properly laminated by a heating reaction.

On the other hand, for the purpose of improving productivity, simultaneous lamination of multiple sheets and simultaneous multi-stage manufacturing by devices are generally employed. Under such circumstances, thermoplastic liquid crystal polymer materials can be expected to improve productivity by utilizing them as thermoplastic resins. In addition, in terms of physical properties, water absorption and dielectric loss are extremely low compared to other materials. Representatives of high-frequency transmission applications are receiving high attention.

The thermoplastic liquid crystal polymer material enables multilayering by thermocompression bonding by utilizing thermoplasticity, but on the other hand, heat resistance at the time of multilayering is also required. That is, even when the laminated body is produced under the condition that the non-metallic layer used for multilayering is properly softened/plasticized to firmly adhere to the metal layer or non-metallic layer of the laminated board, the non-metallic layer of the laminated board Even when the metal layer has high heat resistance, it is possible to manufacture a stable product with a wide process window (optimum range of manufacturing conditions).

As an example of a stable production method for a multilayer laminate that does not use an adhesive, Patent Document 1 (Japanese Patent No. 4004139 ) and Patent Document 2 (Japanese Patent No. 4138995 ) describe thermoplastic materials with different melting points. A method for manufacturing a metal laminate of a liquid crystal polymer film and a metal layer and a multilayer laminate of a non-metal layer.

In the method of manufacturing a multilayer substrate proposed in Patent Document 3 (Japanese Patent No. 3893930), a plurality of sheets including a thermoplastic resin are laminated, and the laminated sheets are held one by one in a sheet holder. By applying heat and pressure through a flexible material, multilayer substrates can be manufactured without using conventional batch-type vacuum chambers. Therefore, according to this manufacturing method, compared with the steps using the conventional batch-type vacuum chamber, the production efficiency can be greatly improved.

Regarding the heat resistance of the material itself, as the heat resistance of the thermoplastic liquid crystal polymer material, Patent Document 4 (Japanese Patent No. 3878741 A) describes that the melting point of the thermoplastic liquid crystal polymer having a melting point of 300° C. or lower is raised to 300° C. or higher. Methods. [Prior Art Literature] [Patent Document]

Patent Document 1: Japanese Patent No. 4004139 Patent Document 2: Japanese Patent No. 4138995 Patent Document 3: Japanese Patent No. 3893930 Patent Document 4: Japanese Patent No. 3878741

[Problem to be solved by the invention]

However, in the multilayer laminates proposed in Patent Documents 1 and 2, it is difficult to expand the operating range due to the point of using a thermoplastic liquid crystal polymer film with a low melting point. In addition, when raising the melting point of the thermoplastic liquid crystal polymer film, a multi-stage heat treatment of 4 hours or more is required, which has a problem of lack of productivity.

Also, in the method proposed in Patent Document 3, when the laminated sheet is rapidly heated through the flexible material, the thermoplastic resin undergoes a hydrolysis reaction. For example, in thermoplastic liquid crystal polymers, etc., the fluidity of the resin increases, There are problems such as misalignment of the conductor pattern and occurrence of voids in the resin film.

Furthermore, in the method described in Patent Document 4, although the melting point of the thermoplastic liquid crystal polymer can be raised by heating in multiple stages for more than 4 hours, this method has a problem of lack of productivity.

Therefore, there is a limit to the improvement of equipment and adhesives for expanding the operating range when multilayering using a thermoplastic liquid crystal polymer film, and it is not possible to fully satisfy the demand for further multilayering. In addition, simply raising the melting point cannot satisfy the market demand including the productivity at the time of production of the thermoplastic liquid crystal polymer film.

Therefore, an object of the present invention is to provide a thermoplastic liquid crystal polymer film, a laminate, and a molded article having a wide range of operations for multilayering, and a method for easily producing them. [Means to solve the problem]

As a result of dedicated research by the present inventors in order to solve the above-mentioned problems, it was surprisingly found that in crystals containing a highly uniform orthorhombic crystal structure, the 2θ=14～14 detected by wide-angle X-ray diffraction measurement When the integrated intensity at 26 degrees is set to A, the integrated intensity at 2θ=22.3 to 24.3 degrees is set to B, and B/A×100=UC, the thermoplastic liquid crystal polymer film in which UC exists in a specific range is heat-resistant In the heat-resistant step, the crystal structure is controlled by a different mechanism from the conventional heat-resistant step. This kind of thermoplastic liquid crystal polymer film can control the time required for the formation of crystals that match the required heat resistance, so it will not only shorten the heat resistance. In addition, the time required for this process has a wide operating range due to high heat resistance in both the lamination step and the circuit processing step, and the present invention has been completed.

That is, the present invention can be configured in the following aspects. [Aspect 1] A thermoplastic liquid crystal polymer film composed of a polymer capable of forming an optically anisotropic molten phase (hereinafter referred to as a thermoplastic liquid crystal polymer), wherein the polymer part is composed of In the diffraction curve detected by wide-angle X-ray diffraction measurement, the integrated intensity on the baseline of 2θ=14-26 degrees is set to A, and the quantitative curve of the main peak is approximately linear at 2θ=22.3-24.3 degrees When the integral intensity of the quantitative curve of the secondary peak after removal of the function is set to B, and set to B/A×100=UC, the following formula (1) is satisfied, 0≦UC≦2.0 (1). [Aspect 2] The thermoplastic liquid crystal polymer film as described in Aspect 1, which satisfies the following formula (2): 0.1≦UC≦1.5 (2). [Aspect 3] The thermoplastic liquid crystal polymer film as described in Aspect 1 or 2, wherein the full width at half maximum of the aforementioned main peak having a maximum value at 2θ=20±1 degrees is set to At SC (degrees), 1.4≦SC is satisfied. [Aspect 4] The thermoplastic liquid crystal polymer film according to any one of Aspects 1 to 3, wherein, using a differential scanning calorimeter, in a temperature range from room temperature to 400°C, at 10°C/ The position of the endothermic peak that appears when the temperature is raised at a rate of min is 310° C. or higher (preferably 315° C. or higher, more preferably 320° C. or higher). [Aspect 5] A laminate comprising at least one layer of the thermoplastic liquid crystal polymer film as described in any one of Aspects 1 to 4. [Aspect 6] The laminate according to Aspect 5, further comprising at least one metal layer. [Aspect 7] The laminate as described in Aspect 6, wherein the metal layer is made of copper, copper alloy, aluminum, aluminum alloy, nickel, nickel alloy, iron, iron alloy, silver, silver alloy, and Consists of at least one of the composite metal species. [Aspect 8] A molded body formed of the thermoplastic liquid crystal polymer film described in any one of Aspects 1 to 4 or the laminate described in any one of Aspects 5 to 7 . [Aspect 9] The molded body according to Aspect 8, which is a circuit board. [Aspect 10] The molded article according to Aspect 8 or 9, which is a high-frequency circuit board, a vehicle sensor, a mobile circuit board, or an antenna. [Aspect 11] A method for producing a thermoplastic liquid crystal polymer film as described in any one of Aspects 1 to 4, wherein the rising rate Rtm from the melting point is 0.20°C/min or more (preferably 0.22°C/min. Min or more, more preferably 0.25°C/min or more, and still more preferably 0.26°C/min or more), the thermoplastic liquid crystal polymer film (material film) composed of thermoplastic liquid crystal polymer is subjected to heat treatment to be heat-resistant. [Aspect 12] The method for producing a thermoplastic liquid crystal polymer film as described in Aspect 11, wherein the heat treatment is performed in one stage or in multiple stages, and when the melting point of the thermoplastic liquid crystal polymer is Tm ₀ , Tm ₀ °C or lower, preferably (Tm ₀ -2)°C or lower, is heat-resistant by performing the first heat treatment. [Aspect 13] The method for producing a thermoplastic liquid crystal polymer film as described in Aspect 11 or 12, wherein, as a heat source, a heat source selected from a hot air oven, a steam oven, an electric heater, an infrared heater, a ceramic heater, and a heat roll is used. , heat press, and at least one of electromagnetic wave irradiation machine. [Aspect 14] The method for producing a thermoplastic liquid crystal polymer film according to any one of aspects 11 to 13, wherein the heat treatment is performed in one stage. [Aspect 15] A method for producing a laminate according to any one of aspects 5 to 7, wherein, for a laminate having a polymer layer composed of a thermoplastic liquid crystal polymer, that is, the aforementioned polymer The layer system is composed of a thermoplastic liquid crystal polymer with a melting point rise rate Rtm of 0.20°C/min or higher (preferably 0.22°C/min or higher, more preferably 0.25°C/min or higher, and still more preferably 0.26°C/min or higher) The laminate is heat-treated to be heat-resistant. [Aspect 16] The method for producing a laminate according to Aspect 15, wherein the heat treatment is performed in one or more stages, and when the melting point of the thermoplastic liquid crystal polymer is Tm ₀ , at Tm ₀ °C Thereafter, it is preferable to perform the first heat treatment at (Tm ₀ -2)°C or lower to achieve heat resistance. [Aspect 17] The method for producing a laminate according to Aspect 15 or 16, wherein, as the heat source, a heat source selected from a hot air oven, a steam oven, an electric heater, an infrared heater, a ceramic heater, a hot roll, and a hot press is used. , and at least one of an electromagnetic wave irradiation machine. [Aspect 18] A method comprising the thermoplastic liquid crystal polymer film as described in any one of Aspects 1 to 4, and/or as described in any one of Aspects 5 to 7 The laminate is post-processed to produce a molded body.

In Aspect 11, the so-called melting point rise rate of the thermoplastic liquid crystal polymer refers to measuring a thermoplastic liquid crystal polymer film ( When heating, cooling, and reheating, the temperature at which an endothermic peak appears during reheating is defined as the melting point Tm ₀ of the thermoplastic liquid crystal polymer, and the thermoplastic liquid crystal polymer film is heated at a temperature of Tm ₀ -10°C. After one hour of heat treatment, in the differential scanning thermal analysis measurement, when heating from normal temperature (for example, 25°C) to a specified temperature (for example, 400°C), when the temperature at which the endothermic peak appears is set as Tm', Rtm=(Tm '-Tm ₀ )/60 calculated value. The temperature change rate (heating speed, temperature falling speed) in the above-mentioned differential scanning thermal analysis measurement can be 10° C./min.

In this specification, a laminate means a structure in which an adherend is laminated on a thermoplastic liquid crystal polymer film, and a molded body means a structure in which a circuit or the like is formed on a thermoplastic liquid crystal polymer film. [Effect of Invention]

In the present invention, it is possible to manufacture thermoplastic liquid crystal polymer films, laminates, and moldings that have a wide operating range at the time of lamination/circuit processing due to high heat resistance. Therefore, for example, it is accompanied by simplification of the multilayer lamination process that has been complicated until now. , and the laminate can be manufactured at low cost. Furthermore, it becomes possible to manufacture a super multilayer laminate substrate without using special equipment or jigs.

In addition, any combination of at least two constituent elements disclosed in the patent claims and/or the specification is also included in the present invention. In particular, any combination of two or more of the claims described in the claims is also included in the present invention.

[Mode for Carrying Out the Invention]

Embodiments of the present invention will be described below. In addition, in the following description, specific examples are disclosed as compounds exhibiting specific functions, but the present invention is not limited thereto. In addition, unless otherwise specified, the illustrated materials may be used alone or in combination.

[Thermoplastic liquid crystal polymer] The thermoplastic liquid crystal polymer film of the present invention is composed of thermoplastic liquid crystal polymer. The thermoplastic liquid crystal polymer is composed of a melt-formable liquid crystal polymer (or a polymer capable of forming an optically anisotropic melt phase), and its chemical composition is not particularly limited as long as it is a melt-formable liquid crystal polymer. However, examples thereof include thermoplastic liquid crystal polyesters, thermoplastic liquid crystal polyesteramides into which amide bonds have been introduced, and the like.

In addition, the thermoplastic liquid crystal polymer may be derived from isocyanate in which an imide bond, a carbonate bond, a carbodiimide bond, an isocyanurate bond, or the like has been further introduced into an aromatic polyester or an aromatic polyester amide. Polymers such as bonds.

Specific examples of thermoplastic liquid crystal polymers that can be used in the present invention include known thermoplastic liquid crystal polyesters and thermoplastic liquid crystal polymers derived from compounds classified into (1) to (4) and derivatives thereof as exemplified below. Polyesteramide. However, in order to form a polymer capable of forming an optically anisotropic melt phase, there is naturally an appropriate range in the combination of various raw material compounds.

(1) Aromatic or aliphatic diols (refer to Table 1 for representative examples) [Table 1]

(2) Aromatic or aliphatic dicarboxylic acids (refer to Table 2 for representative examples) [Table 2]

(3) Aromatic hydroxycarboxylic acid (refer to Table 3 for representative examples) [Table 3]

(4) Aromatic diamine, aromatic hydroxylamine or aromatic aminocarboxylic acid (refer to Table 4 for representative examples) [Table 4]

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

[表6]

[table 5]

[Table 6]

Among these copolymers, preferred are polymers comprising at least p-hydroxybenzoic acid and/or 6-hydroxy-2-naphthoic acid as repeating units, especially, preferably (i) comprising p-hydroxybenzoic acid and 6- A polymer of repeating units of hydroxy-2-naphthoic acid, or (ii) comprising at least one aromatic hydroxycarboxylic acid selected from the group consisting of p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, at least one A copolymer of repeating units of aromatic diol and at least one aromatic dicarboxylic acid.

In the case where the thermoplastic liquid crystal polymer is a copolymer comprising repeating units of p-hydroxybenzoic acid (A) and 6-hydroxyl-2-naphthoic acid (B), the molar ratio (A)/(B) is preferably ( A)/(B)=10/90～90/10, more preferably 50/50～90/10, even better 75/25～90/10, and even better 75/25～85/15, especially The best is 77/23～80/20.

For example, in the case of the copolymer of (i), in addition to the repeating units of p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, from the viewpoint of molecular weight adjustment, etc., it may also contain aromatic diol, aromatic A repeating unit composed of a family of dicarboxylic acids (eg, terephthalic acid).

Also, in the case of the copolymer of (ii), it may be a copolymer comprising repeating units: at least one aromatic hydroxycarboxylic acid selected from the group consisting of p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid; At least one aromatic diol selected from the group comprising 4,4'-dihydroxybiphenyl, hydroquinone, phenylhydroquinone, and 4,4'-dihydroxydiphenyl ether; and selected from the group comprising p- At least one aromatic dicarboxylic acid selected from the group of phthalic acid, isophthalic acid, and 2,6-naphthalene dicarboxylic acid.

In addition, in the present invention, the formation of an optically anisotropic molten phase can be confirmed, for example, by placing a sample on a heat stage, heating it under a nitrogen gas atmosphere, and observing the transmitted light of the sample.

Among the above-mentioned copolymers, the thermoplastic liquid crystal polymer film of the present invention is preferably composed of a thermoplastic liquid crystal polymer having a melting point increase rate Rtm of 0.20° C./min or higher. More preferably, it may be above 0.22°C/min, even more preferably above 0.25°C/min, and even more preferably above 0.26°C/min. The upper limit of the melting point increase rate Rtm of the thermoplastic liquid crystal polymer is not particularly limited, but may be 1.0° C./min or less.

The melting point rising rate RTm was calculated as follows. First, using a differential scanning thermal analyzer, put a part of the thermoplastic liquid crystal polymer film into the sample container, and after heating up from room temperature (for example, 25°C) to 400°C at a rate of 10°C/min, The temperature was cooled to room temperature, and the position of the endothermic peak that appeared when the temperature was raised from room temperature to 400°C at a rate of 10°C/min was taken as the intrinsic melting point (hereinafter referred to as Tm) of the thermoplastic liquid crystal polymer constituting the thermoplastic liquid crystal polymer film. ₀ ) to measure. In addition, after treating the thermoplastic liquid crystal polymer film used for the measurement of Tm ₀ at Tm ₀ -10°C for 60 minutes, put a part of the treated thermoplastic liquid crystal polymer film into the sample container, and set the temperature at 10°C/min The position of the endothermic peak that appears when the speed is raised from room temperature to 400°C is measured as the melting point Tm' of the thermoplastic liquid crystal polymer film that has been heat-treated in Tm ₀ -10°C gas environment for 60 minutes. Based on these measured values, the melting point rise rate Rtm (° C./min) of the thermoplastic liquid crystal polymer constituting the thermoplastic liquid crystal polymer film was calculated by the following formula. Rtm=(Tm'-Tm ₀ )/60

As shown in the Examples and Comparative Examples described later, even when the crystals are composed of the same type of monomers, the packing characteristics of the crystals can vary depending on the slight difference in the composition ratio of the monomers. Therefore, it is difficult to express the packing characteristics of crystals by the constituent ratio of monomers and the like.

On the other hand, the inventors of the present invention have found that by grasping the melting point rise rate, it is possible to grasp the packing characteristics of crystals which contribute to the improvement of the heat resistance of thermoplastic liquid crystal polymers. Thus, as long as it can be confirmed that the melting point rise rate Rtm is a thermoplastic liquid crystal polymer, those skilled in the art of the present invention can easily judge whether there is a crystal packing characteristic that contributes to heat resistance. Moreover, those skilled in the art to which the present invention pertains can heat-treat thermoplastic liquid crystal polymers having crystalline packing properties that contribute to heat-resistant compounds without excessive trial and error, so as to obtain thermoplastic liquid crystal polymers with specified crystallization curves. Liquid crystal polymer film, etc.

The melting point (Tm ₀ ) of the thermoplastic liquid crystal polymer is, for example, preferably in the range of 300-380°C, more preferably in the range of 305-360°C, and even more preferably in the range of 310-350°C. In addition, the melting point can be obtained by observing the thermal behavior of the thermoplastic liquid crystal polymer sample as described above using a differential scanning calorimeter.

Also, from the viewpoint of melt formability, the thermoplastic liquid crystal polymer may have, for example, a melt viscosity of 30-120 Pa·s at a shear rate of (Tm ₀ +20)°C at a shear rate of 1000/s, preferably a melt viscosity of 50-100 Pa ･s.

Among the aforementioned thermoplastic liquid crystal polymers, polyethylene terephthalate, modified polyethylene terephthalate, polyolefin, polycarbonate, polyarylene Thermoplastic polymers such as polyarylate, polyamide, polyphenylene sulfide, polyether ether ketone, fluororesin, and various additives. Moreover, a filler can also be added as needed.

[Method for producing thermoplastic liquid crystal polymer film, laminate or molded product] The thermoplastic liquid crystal polymer film of the present invention can be produced by heat-treating a thermoplastic liquid crystal polymer film (film before heat resistance) composed of a thermoplastic liquid crystal polymer having a melting point rise rate Rtm of 0.20° C./min or higher.

The production method of the thermoplastic liquid crystal polymer film (pre-heat-resistant film) is not particularly limited as long as it is composed of a thermoplastic liquid crystal polymer having a specific melting point rise rate Rtm. For example, the aforementioned thermoplastic liquid crystal polymer can be cast and formed To obtain a film, a film can also be obtained by extruding the molten kneaded product of the aforementioned thermoplastic liquid crystal polymer. As the extrusion molding method, any method may be used, but well-known T-die (T-DIE) method, inflation (Inflation) method, etc. are industrially advantageous. Especially in the inflation method, stress is applied not only in the direction of the mechanical axis of the thermoplastic liquid crystal polymer film (hereinafter referred to as the MD direction) but also in a direction perpendicular thereto (hereinafter referred to as the TD direction). , The TD direction is uniformly extended, so it is possible to obtain a thermoplastic liquid crystal polymer film whose molecular orientation, dielectric properties, etc. have been controlled in the MD direction and the TD direction.

For example, in the extrusion molding by the T-die method, the melt sheet extruded by the T-die can be processed not only for the MD direction of the thermoplastic liquid crystal polymer film, but also for both this and the TD direction. Stretching to form a film, or stretching the molten sheet extruded by a T-die in the MD direction first, and then stretching in the TD direction to form a film.

Also, in extrusion molding by the inflation method, for a cylindrical sheet melted and extruded by a ring die, the draw ratio (equivalent to the stretch ratio in the MD direction) and the blow ratio (equivalent to the stretching ratio in the TD direction) can be specified. The extension ratio) is stretched to form a film.

The stretching ratio of such extrusion molding is, for example, about 1.0 to 10, preferably about 1.2 to 7, and more preferably about 1.3 to 7 as the stretching ratio (or draw ratio) in the MD direction. Also, the stretch ratio (or blow ratio) in the TD direction is, for example, about 1.5-20, preferably about 2-15, and more preferably about 2.5-14.

The thus obtained thermoplastic liquid crystal polymer film (film before heat-resistant, material film) is heat-treated to be heat-resistant. The method of heat treatment is not particularly limited as long as the heat-resistant thermoplastic liquid crystal polymer film has a specific crystallization curve. For example, the thermoplastic liquid crystal polymer film (film before heat resistance) can be directly heat-treated by roll-to-roll, etc. It is also possible to heat-treat the laminate of the temporarily obtained thermoplastic liquid crystal polymer film (film before heat resistance) and the adherend, or to heat-treat the laminate on the thermoplastic liquid crystal polymer film (film before heat resistance) ) The laminate with the metal layer formed directly on it is subjected to heat treatment. Such a laminate can be produced by thermocompression bonding methods such as hot pressing, hot rolls, and double belt presses, but is not particularly limited thereto.

As the heat source upon heat treatment, a known or commonly used heat source can be used. Preferable heat sources include, for example, hot air ovens, steam ovens, electric heaters, infrared heaters, ceramic heaters, hot rolls, hot presses, electromagnetic wave irradiators (eg, microwave irradiators, etc.) and the like. These heat sources can be used individually or in combination of 2 or more types.

Although heat resistance can be performed by one-stage or multiple-stage heat treatment, in the thermoplastic liquid crystal polymer film of the present invention, one to two-stage heat treatment is preferred, and one-stage heat treatment is more preferred.

In the heat treatment of one stage or multiple stages, for example, as the first heat treatment, when the melting point of the thermoplastic liquid crystal polymer is set to (Tm ₀ ), it may be below Tm ₀ °C, preferably (Tm ₀ -2) Heat treatment below ℃. The heating temperature is preferably (Tm ₀ -50)°C or higher, more preferably (Tm ₀ -40)°C or higher. Here, the melting point (Tm ₀ ) of the thermoplastic liquid crystal polymer can be obtained by the aforementioned melting point measurement method. In one-stage heat treatment, heat resistance is achieved only by the first heat treatment, and in multiple-stage heat treatment, after the first heat treatment, the heat treatment temperature of the next stage can be performed at a higher heating temperature than the heat treatment temperature of the previous stage. heat treatment.

The melting point of the thermoplastic liquid crystal polymer film is raised by heat treatment, but in the present invention, rapid heat resistance can be achieved, so the heating temperature may be determined based on the melting point (Tm ₀ ) of the thermoplastic liquid crystal polymer film.

Therefore, the heating temperature after the second _heat treatment can be carried out above the melting point (Tm ₀ ) of the thermoplastic liquid crystal polymer according to need. It is best to be below (Tm ₀ +20)°C.

The heating time at each stage in the heat treatment can be appropriately set according to the heating temperature, the stage of the heat treatment, and the like. In the present invention, since heat resistance can be achieved rapidly, the overall heating time can be, for example, about 10 minutes to 3 hours, preferably about 10 minutes to 2 hours (for example, about 30 minutes to 2 hours), and more preferably about 10 minutes to 2 hours. About 10 minutes to 1.3 hours (for example, about 45 minutes to 1.3 hours).

The adherend is not particularly limited as long as it can be used as a heat-treated support, and examples thereof include a metal layer, a heat-resistant resin layer, and the like.

The metal constituting the metal layer is not particularly limited as long as it is a conductive metal, but examples include copper, copper alloys, aluminum, aluminum alloys, nickel, nickel alloys, iron, iron alloys, silver, silver alloys, and Such composite metal types, etc. Among these metals, other metal species may be contained at 2000 mass ppm or less, and unavoidable impurities may be present.

In the case of using a metal layer as an adherend, after heat treatment, it can be used as it is in the form of a laminate in which the thermoplastic liquid crystal polymer film part has been heat-resistant. For example, copper, copper alloys, silver, and silver alloys may be used when conductivity and heat dissipation are required, iron alloys may be used if strong magnetism is required, and aluminum may be used if cheap ones are required.

Preferably, copper can be used as the metal species for the circuit substrate. Specifically, the metal layer can be composed of copper containing more than 99.8% by mass, and then containing less than 2000 mass ppm of silver, tin, zinc, chromium, boron, It is composed of at least one other metal species from the group of titanium, magnesium, phosphorus, silicon, iron, gold, nickel, and cobalt, and copper as an unavoidable impurity in the remainder.

As a method of forming the metal layer on the thermoplastic liquid crystal polymer film, known methods can be used. For example, a metal layer can be vapor-deposited on a thermoplastic liquid crystal polymer film, and a metal layer can also be formed by electroless plating or electrolytic plating. In addition, a metal foil (for example, copper foil) may be laminated on the surface of the thermoplastic liquid crystal polymer film by thermocompression bonding. Copper foil is not particularly limited as long as it is copper foil that can be used for a circuit board, and any of rolled copper foil and electrolytic copper foil may be used.

As the resin constituting the heat-resistant resin layer, resins or thermosetting resins having a melting point higher than the highest temperature achieved by heat treatment may be mentioned, preferably polyimide, polyphenylene ether (polyphenylene ether), poly Benzene sulfur, fluororesins (for example, polytetrafluoroethylene), and the like.

As a method of forming the heat-resistant resin layer on the thermoplastic liquid crystal polymer film, known methods can be used. For example, the heat-resistant resin film can be laminated on the surface of the thermoplastic liquid crystal polymer film by thermocompression bonding.

In the above-mentioned laminate of the thermoplastic liquid crystal polymer film and the metal layer, if the thickness of each single layer is Ta (μm) and Tb (μm), Ta and Tb can be selected from the range of 0.1 to 500 μm, respectively. From the viewpoint of thinning and weight reduction in recent years, Ta is preferably 1 to 175 μm, and more preferably about 5 to 130 μm. Also, Tb is preferably 1 to 20 μm, more preferably about 2 to 15 μm.

In addition, the aforementioned laminate has a multi-layer structure of a thermoplastic liquid crystal polymer film and a metal layer, including at least one layer of thermoplastic liquid crystal polymer film and at least one metal layer. For example, as a laminate of a multilayer structure, those having the following laminate structures can be cited, but not limited thereto, (i) Metal layer/thermoplastic liquid crystal polymer film (ii) Metal layer/thermoplastic liquid crystal polymer film/metal layer (iii) thermoplastic liquid crystal polymer film/thermoplastic liquid crystal polymer film/metal layer (iv) thermoplastic liquid crystal polymer film/metal layer/thermoplastic liquid crystal polymer film (v) Metal layer/thermoplastic liquid crystal polymer film/thermoplastic liquid crystal polymer film/metal layer (vi) Metal layer/thermoplastic liquid crystal polymer film/metal layer/thermoplastic liquid crystal polymer film/metal layer, etc.

In addition, the thermoplastic liquid crystal polymer film may be used in the form of a laminate as it is in the state of being laminated with the adherend, or the thermoplastic liquid crystal polymer film may be used alone after being separated from the adherend. Furthermore, the thermoplastic liquid crystal polymer film can also be multilayered via an appropriate adhesive layer. Examples of the adhesive layer include polyphenylene ether, epoxy resin, polyurethane, thermoplastic polyimide, polyetherimide, and the like.

Also, for example, a molded article can also be produced by post-processing a thermoplastic liquid crystal polymer film and/or a laminate.

For example, in the case of a thermoplastic liquid crystal polymer film, a molded body such as a circuit board (or a unit circuit board) can be manufactured by forming a conductive pattern on the surface. Moreover, molded objects such as circuit boards (or unit circuit boards) can be produced by forming conductive patterns on the metal layers of the laminate. Furthermore, a unit circuit board on which a conductor pattern has been formed can be laminated on another board material to form a molded body (or a circuit board) such as a circuit board. As the substrate material, the above-mentioned thermoplastic liquid crystal polymer film, metal layer, unit circuit board, etc. can be exemplified, and an adhesive layer can also be used if necessary.

Alternatively, for a preformed article having a polymer layer composed of a thermoplastic liquid crystal polymer, that is, a preform in which the aforementioned polymer layer is composed of a thermoplastic liquid crystal polymer having a melting point rise rate Rtm of 0.20°C/min or higher The body is subjected to heat treatment to obtain a shaped body. In this case, the polymer portion of the molded article has UC in a specific range described later.

[Thermoplastic liquid crystal polymer films, laminates and moldings] The thermoplastic liquid crystal polymer film, laminate, and molding system of the present invention produce crystals with a specific crystal structure (orthorhombic crystal structure) in the thermoplastic liquid crystal polymer by heat treatment, so the thermoplastic liquid crystal polymer part is exposed to wide-angle X-rays. In the diffraction quantitative curve detected by diffraction measurement, the integrated intensity on the baseline of 2θ=14-26 degrees is set as A, and the quantitative curve of the main peak is approximated to a linear function at 2θ=22.3-24.3 degrees and removed When the integral intensity of the quantitative curve of the subsequent secondary peak is B and B/A×100=UC, the following formula (1) is satisfied, and the following formula (2) is more preferably satisfied. 0≦UC≦2.0 (1) 0.1≦UC≦1.5 (2)

The so-called UC in the present invention can be regarded as an indicator of the uniformity (crystallinity) of the orthorhombic crystal structure. The larger the value, the more sensitive the diffraction signal of the (200) plane of the orthorhombic crystal. That is, orthorhombic crystals with high uniformity in the crystal structure grow significantly. In addition, UC by wide-angle X-ray diffraction measurement is a value measured by the method described in the Example mentioned later. From the above viewpoint, UC is preferably at least 0.20, more preferably at least 0.50, even more preferably at least 0.80, still more preferably at least 1.00, and most preferably at least 1.25.

Also, when the full width at half maximum of the main peak having a maximum value at 2θ=20±1° is SC (°), it is preferable to satisfy 1.4≦SC. When the value of SC is high, the generation degree of orthorhombic crystals can be further improved. When the melting point is raised in general heat treatment, the heat resistance can be improved by increasing the value of SC, but in the present invention, the thermoplastic liquid crystal polymer part has a parameter UC of a specific value derived from a specific crystal structure, even if SC The value of is relatively low, and a high melting point can also be achieved.

The half width SC of the main peak is more preferably 1.7 or less. When 1.4≦SC≦1.7 is satisfied, it can be considered that orthorhombic crystals with a large crystallite size are generated in most thin films.

In addition, the thermoplastic liquid crystal polymer film of the present invention uses a differential scanning thermal analyzer, and the position of the endothermic peak that appears when the temperature is raised from room temperature (for example, 25° C.) to a temperature range of 400° C. at a rate of 10° C./min is set as Melting point (Tm) of thermoplastic liquid crystal polymer films. For example, the melting point (Tm) of the thermoplastic liquid crystal polymer film may be above 310°C, preferably above 315°C, more preferably above 320°C. The upper limit of the melting point (Tm) is not particularly limited, but may be, for example, about 400°C.

For example, when the relationship between SC and melting point (Tm) is represented by Tm/SC in the thermoplastic liquid crystal polymer part, in the thermoplastic liquid crystal polymer film, laminate and molded article of the present invention, Tm/SC can be, for example, About 180-240, preferably about 182-235, more preferably about 185-230.

The greatest feature of the present invention is that by using the above parameters to describe the heat resistance and the productivity of the laminate when it is used as a laminate or a molded product, a novel thermoplasticity that has not been seen so far has been discovered. Liquid crystal polymer films, laminates and moldings.

Even if it is a commercially available thermoplastic liquid crystal polymer film, for example, there are high heat-resistant films having a melting point of 280 to 340° C., but in such thermoplastic liquid crystal polymer film, UC does not exist in the specified range. In such a thermoplastic liquid crystal polymer film, the heat resistance is not performed by the formation of orthorhombic crystals, but mainly by the solid-state polymerization process, so the heat resistance becomes a heat treatment that requires a lot of time, and it is difficult to achieve productivity. It is disadvantageous in point of view.

Here, the important point is that according to the present invention, even if it has the same melting point as that of the thermoplastic liquid crystal polymer film obtained by the prior art, in the thermoplastic liquid crystal polymer film, laminate and molded article of the present invention, because UC exists in a specific range, so its heat resistance and productivity are also high. Also, by controlling the heat treatment temperature and time for heat resistance, the melting point of the thermoplastic liquid crystal polymer film can be arbitrarily controlled to the same temperature as conventional ones.

Therefore, the thermoplastic liquid crystal polymer film, laminate, and molded article of the present invention are not only excellent in heat resistance, but also have a wide operating range, so they can be suitably used in various applications.

For example, a laminate comprising at least one thermoplastic liquid crystal polymer film and at least one metal layer can form a circuit pattern on the metal layer, and is useful as a circuit board. In addition, when the molded body has a plurality of circuit layers, it can meet the demands for higher density and higher functionality, so the molded body is suitable as a multilayer circuit board.

The thermoplastic liquid crystal polymer film, laminate, and molded article of the present invention are not only excellent in productivity, but also have remarkably high heat resistance, so they are suitable for applications such as high-frequency circuit boards, automotive sensors, mobile circuit boards, and antennas. , but not limited to these. [Example]

The following examples are given to illustrate the present invention in more detail, but the present invention is not limited by these examples.

(film thickness) The obtained thermoplastic liquid crystal polymer film was measured at intervals of 1 cm in the TD direction using a digital thickness meter (manufactured by Mitutoyo Co., Ltd.), and the average value of 10 points arbitrarily selected from the center and edge was defined as the film thickness.

(Tm) Using a differential scanning thermal analyzer (manufactured by Shimadzu Corporation), sample a specified size from the thermoplastic liquid crystal polymer films obtained in Examples and Comparative Examples and put them into sample containers. The position of the endothermic peak that appeared when the temperature was raised to 400° C. was defined as the melting point Tm of the thermoplastic liquid crystal polymer film.

(Tm ₀ and Rtm) Using a differential scanning thermal analyzer (manufactured by Shimadzu Corporation), a sample of a specified size is sampled from a thermoplastic liquid crystal polymer film (film before heat resistance), and placed in a sample container, and the temperature is increased at a rate of 10°C/min. After heating up from room temperature to 400°C, cool down to room temperature at a rate of 10°C/min, and set the position of the endothermic peak that appears when the temperature is raised from room temperature to 400°C at a rate of 10°C/min again to constitute a thermoplastic liquid crystal The melting point Tm ₀ of the thermoplastic liquid crystal polymer of the polymer film.

Also, the thermoplastic liquid crystal polymer film (film before heat resistance) was treated in a batch oven in an atmosphere of Tm ₀ -10°C for 60 minutes. Using a differential scanning calorimeter, sample a specified size from the processed thermoplastic liquid crystal polymer film and put it into a sample container, and set the position of the endothermic peak that appears when the temperature is raised from room temperature to 400°C at a rate of 10°C/min as From the melting point Tm' of the thermoplastic liquid crystal polymer film treated above, the melting point rise rate Rtm (° C./min) of the thermoplastic liquid crystal polymer constituting the thermoplastic liquid crystal polymer film was calculated by the following formula. Rtm=(Tm'-Tm ₀ )/60

(Wide Angle X-ray Diffraction) For the wide-angle X-ray diffraction measurement system, a D8 Discover device manufactured by Bruker AXS Co., Ltd. was used. Cut the thermoplastic liquid crystal polymer film into a 10mm quadrilateral and attach it to a standard sample holder. In order to increase the S/N ratio of data, a plurality of thermoplastic liquid crystal polymer films are stacked so that the MD directions are aligned, and the thickness is adjusted to be about 0.5 mm. The X-ray source system was CuKα, the filament voltage was 45 kV, and the current was 110 mA. The collimator is 0.3mm.

The standard sample holder is attached to the device, and the position is adjusted so that X-rays are irradiated from a direction consistent with the normal line of the thermoplastic liquid crystal polymer film. That is, to the surface of the thermoplastic liquid crystal polymer film, X-rays are irradiated perpendicularly. The distance between the thermoplastic liquid crystal polymer film and the detector (camera distance) was set to 100 mm. The detector uses a two-dimensional PSPC detector to obtain a two-dimensional diffraction image. The detector is arranged behind the sample, and is arranged in such a way that the normal line of the thermoplastic liquid crystal polymer film, the normal line of the detector, and the X-ray irradiation direction are all consistent. The exposure time was set at 600 seconds.

The obtained two-dimensional diffraction image is subjected to circular average processing and converted into a one-dimensional quantitative curve (data 1). The range of the circular average is set to 10 to 30 degrees in terms of diffraction angle (2θ). The azimuth range is set to 0~180 degrees. The 2θ step is set to 0.05 degrees. In addition, an azimuth angle of 0 degrees is made to correspond to the MD direction of the thermoplastic liquid crystal polymer film.

The converted one-dimensional quantitative curve (data 1) is processed by using the background value data (measurement data when the sample is not installed) obtained under the same conditions to perform processing such as parasitic scattering. That is, after the background value data is one-dimensionally plotted, it is subtracted from the data of the thermoplastic liquid crystal polymer film. Take this as data2.

For data 2 treated with background values, a baseline was set and subtracted. The baseline was set as a linear function connecting the intensity values at 14 and 26 degrees 2Θ in the background value processed data. In addition, the intensity values at 14° and 26° are respectively set as the average value (0.05° interval) of the intensity in the ranges of 13.8° to 14.2° and 25.8° to 26.2°. Subtract the above linear function from data 2. Take this as data 3. For the data 3, the integrated intensity was obtained in the range of the diffraction angle 2θ of 14 to 26 degrees, and the obtained integrated intensity was defined as A.

Furthermore, in Data 3, a linear function connecting intensity values at diffraction angles 2θ of 22.3 degrees and 24.3 degrees is calculated, and the linear function is subtracted from Data 3 again. Take this as data 4. For data 4, the integral intensity (B) in the range of 2θ of 22.3 to 24.3 degrees was obtained. Then calculate B/A×100(=UC).

In addition, in data 3, the maximum intensity value (M) at which the diffraction angle 2θ is in the range of 19 to 21 degrees is obtained, and the intensity (M/2) which is half of it is obtained. In data 3, the diffraction angle 2θ of the two points whose intensity is M/2 is obtained, and the difference in 2θ between the two points is calculated and set as the full width at half maximum (=SC). This value can be regarded as an index showing the width of the diffraction peak from the crystal.

(Manufacturing of metal-clad laminates) As shown in FIG. 1, a thermoplastic liquid crystal polymer film 1 and a metal foil 2 are laminated to form a module. As the metal foil, the product made by Fukuda Metal Foil Powder Industry Co., Ltd. (CF-H9A-DS-HD2-12 thickness 12 μm) was used. This assembly was heated from room temperature (25°C) to 250°C at 6°C/min under vacuum in a vacuum press made by Kitagawa Seiki Co., Ltd., held for 15 minutes, and then raised to After 300°C, make it thermocompression-bonded under the condition of surface pressure 4MPa, and then cool down to 250°C at 7°C/min after 10 minutes, and cool rapidly after reaching 250°C, thereby confirming that it is 50°C, release the vacuum, and produce thermoplasticity. Metal-clad laminate 3 of liquid crystal polymer film 1 and metal foil 2 .

(heat resistance - solder float) Heat resistance due to solder float is measured by investigating whether the surface of the thermoplastic liquid crystal polymer film maintains its original shape on a molten solder bath kept at a specified temperature. That is, the metal-clad laminate 3 was placed on a solder bath at 288° C. for 60 seconds, and morphological changes such as swelling and deformation on the surface of the thermoplastic liquid crystal polymer film were observed visually. The evaluation criteria are as follows. A: Swelling and deformation were hardly observed by the solder bath for 60 seconds. B: Swelling and some severe deformation were confirmed by the solder bath for 60 seconds. Hereinafter, A described in the table indicates pass, and B indicates fail.

(Heat Resistance - Laminar Flow/Operating Range) The heat resistance due to laminar flow was evaluated by observing the shape change of the thermoplastic liquid crystal polymer film at the four corners of the multilayer substrate. As shown in FIG. 2, two metal-clad laminates 3 obtained in FIG. 1 are stacked so that the thermoplastic liquid crystal polymer films 1 are aligned with each other to make a module. The upper and lower surfaces of the module were respectively provided with SUS boards 4 and cushioning materials 5 to clamp the module, and then thermocompression-bonded in a vacuum press at 310°C and a surface pressure of 2 MPa to produce a multi-layer laminated substrate. The shape change of the thermoplastic liquid crystal polymer film at the four corners of the produced multi-layer laminate substrate was visually observed, and evaluated according to the following criteria. A: The thermoplastic liquid crystal polymer hardly flowed, and no burrs larger than 1 mm were observed from the metal layer at the four corners. B: Under the lamination condition, due to the flow of the thermoplastic liquid crystal polymer, burrs larger than 1 mm were confirmed from the metal layer at any part of the four corners.

(productive) Productivity was evaluated for thermoplastic liquid crystal polymer films (films before heat resistance). In the examples and comparative examples described later, the melting point was raised to 325°C after heat treatment for 1 hour or the first heat treatment in multiple stages of heat treatment. The above case was set as A, and the case where more time was required or the case where the melting point did not rise to 325° C. or higher after heat treatment for 1 hour was set as B.

(Production of thermoplastic liquid crystal polymer) As a representative example of polymerization of thermoplastic liquid crystal polymers, the method of Example 1 is as follows. Drop into p-hydroxybenzoic acid 6.1kg (23 mole parts), 2-hydroxyl-6-naphthoic acid 28.1kg (77 mole parts), and acetic anhydride 20.1kg, in acetylation (160 ℃, about 2 hours), the temperature was raised at 1° C./min and kept at 340° C., and a reduced pressure treatment (1000 Pa) was performed for 60 minutes to carry out melt polycondensation.

<Example 1> (1) Polymerize thermotropic liquid crystalline polyester comprising 23 moles of 6-hydroxy-2-naphthoic acid units and 77 moles of p-hydroxybenzoic acid units. Extrusion molding was performed to obtain a thermoplastic liquid crystal polymer film (film before heat resistance) having a thickness of 50 μm. Tm ₀ of the thermoplastic liquid crystal polymer constituting the obtained thermoplastic liquid crystal polymer film (film before heat resistance) was 310°C. (2) Heat treatment was performed at 290°C for 1 hour on the thermoplastic liquid crystal polymer film (film before heat resistance) obtained above. The Tm of the obtained thermoplastic liquid crystal polymer film was 328°C. (3) Using the thermoplastic liquid crystal polymer film obtained in the above (2) to produce metal-clad laminates and multi-layer laminated substrates. The evaluation results of wide-angle X-ray diffraction, solder float, and laminar flow on the obtained thermoplastic liquid crystal polymer film and multilayer laminated substrate are shown in the table. In addition, FIG. 3 is a graph showing the wide-angle X-ray diffraction curve (data 3) of the heat-treated thermoplastic liquid crystal polymer film obtained in Example 1.

<Example 2> (1) Polymerize thermotropic liquid crystalline polyester comprising 23 moles of 6-hydroxy-2-naphthoic acid units and 77 moles of p-hydroxybenzoic acid units, Extrusion molding was performed to obtain a thermoplastic liquid crystal polymer film (film before heat resistance) having a thickness of 50 μm. Tm ₀ of the thermoplastic liquid crystal polymer constituting the obtained thermoplastic liquid crystal polymer film (film before heat resistance) was 310°C. (2) Heat treatment was performed at 310° C. for 1 hour with respect to the thermoplastic liquid crystal polymer film (film before heat resistance) obtained above. The Tm of the obtained thermoplastic liquid crystal polymer film was 337°C. (3) Using the thermoplastic liquid crystal polymer film obtained in the above (2) to produce metal-clad laminates and multi-layer laminated substrates. The evaluation results of wide-angle X-ray diffraction, solder float, and laminar flow on the obtained thermoplastic liquid crystal polymer film and multilayer laminated substrate are shown in the table.

<Example 3> (1) The thermogenic ratio of 20 moles of 6-hydroxy-2-naphthoic acid units, 80 moles of p-hydroxybenzoic acid units, and 1 mole of terephthalic acid units The liquid crystalline polyester was polymerized and extruded by an inflatable mold to obtain a thermoplastic liquid crystal polymer film (film before heat resistance) with a thickness of 50 μm. Tm ₀ of the thermoplastic liquid crystal polymer constituting the obtained thermoplastic liquid crystal polymer film (film before heat resistance) was 320°C. (2) The thermoplastic liquid crystal polymer film (film before heat resistance) obtained above was heat-treated at 300° C. for 1 hour to produce a film. The Tm of the obtained thermoplastic liquid crystal polymer film was 334°C. (3) Using the thermoplastic liquid crystal polymer film obtained in the above (2) to produce metal-clad laminates and multi-layer laminated substrates. The evaluation results of wide-angle X-ray diffraction, solder float, and laminar flow on the obtained thermoplastic liquid crystal polymer film and multilayer laminated substrate are shown in the table.

<Example 4> (1) Thermotropic liquid crystals containing 20 moles of 6-hydroxy-2-naphthoic acid units, 80 moles of p-hydroxybenzoic acid units, and 1 mole of terephthalic acid Polymerized polyester, extruded by an inflatable die to obtain a thermoplastic liquid crystal polymer film (film before heat resistance) with a thickness of 50 μm. Tm ₀ of the thermoplastic liquid crystal polymer constituting the obtained thermoplastic liquid crystal polymer film (film before heat resistance) was 320°C. (2) The thermoplastic liquid crystal polymer film (film before heat resistance) obtained above was heat-treated at 320° C. for 1 hour to produce a thermoplastic liquid crystal polymer film. The Tm of the obtained thermoplastic liquid crystal polymer film was 360°C. (3) Using the thermoplastic liquid crystal polymer film obtained in the above (2) to produce metal-clad laminates and multi-layer laminated substrates. The evaluation results of wide-angle X-ray diffraction, solder float, and laminar flow on the obtained thermoplastic liquid crystal polymer film and multilayer laminated substrate are shown in the table.

<Comparative Example 1> (1) Polymerize thermotropic liquid crystalline polyester containing 27 moles of 6-hydroxy-2-naphthoic acid units and 73 moles of p-hydroxybenzoic acid units. Extrusion was performed to obtain a thermoplastic liquid crystal polymer film with a thickness of 50 μm. Tm ₀ of the thermoplastic liquid crystal polymer constituting the obtained thermoplastic liquid crystal polymer film was 280°C. (2) Using the thermoplastic liquid crystal polymer film obtained in the above (1) to produce metal-clad laminates and multi-layer laminated substrates. The evaluation results of wide-angle X-ray diffraction, solder float, and laminar flow on the obtained thermoplastic liquid crystal polymer film and multilayer laminated substrate are shown in the table.

<Comparative Example 2> (1) Polymerize thermotropic liquid crystalline polyester containing 23 moles of 6-hydroxy-2-naphthoic acid units and 77 moles of p-hydroxybenzoic acid units. Extrusion was performed to obtain a thermoplastic liquid crystal polymer film with a thickness of 50 μm. Tm ₀ of the thermoplastic liquid crystal polymer constituting the obtained thermoplastic liquid crystal polymer film was 310°C. (2) Using the thermoplastic liquid crystal polymer film obtained in the above (1) to produce metal-clad laminates and multi-layer laminated substrates. The evaluation results of wide-angle X-ray diffraction, solder float, and laminar flow on the obtained thermoplastic liquid crystal polymer film and multilayer laminated substrate are shown in the table.

<Comparative Example 3> (1) Thermotropic liquid crystals containing 20 moles of 6-hydroxy-2-naphthoic acid units, 80 moles of p-hydroxybenzoic acid units, and 1 mole of terephthalic acid Polymerize the permanent polyester and extrude through an inflatable mold to obtain a thermoplastic liquid crystal polymer film with a thickness of 50 μm. Tm ₀ of the thermoplastic liquid crystal polymer constituting the obtained thermoplastic liquid crystal polymer film was 320°C. (2) Using the thermoplastic liquid crystal polymer film obtained in the above (1) to produce metal-clad laminates and multi-layer laminated substrates. The evaluation results of wide-angle X-ray diffraction, solder float, and laminar flow on the obtained thermoplastic liquid crystal polymer film and multilayer laminated substrate are shown in the table.

＜Comparative example 4＞ (1) The material of Comparative Example 1 was heat-treated at 260° C. for 1 hour. The Tm of the obtained thermoplastic liquid crystal polymer film was 290°C. (2) Using the thermoplastic liquid crystal polymer film obtained in the above (1) to produce metal-clad laminates and multi-layer laminated substrates. The evaluation results of wide-angle X-ray diffraction, solder float, and laminar flow on the obtained thermoplastic liquid crystal polymer film and multilayer laminated substrate are shown in the table.

＜Comparative example 5＞ (1) The material of Comparative Example 1 was heat-treated at 280° C. for 1 hour. The Tm of the obtained thermoplastic liquid crystal polymer film was 303°C. (2) Using the thermoplastic liquid crystal polymer film obtained in the above (1) to produce metal-clad laminates and multi-layer laminated substrates. The evaluation results of wide-angle X-ray diffraction, solder float, and laminar flow on the obtained thermoplastic liquid crystal polymer film and multilayer laminated substrate are shown in the table.

＜Comparative example 6＞ (1) The material of Comparative Example 1 was heat-treated at 260°C for 1 hour, and then heat-treated at 280°C for 6 hours. The Tm of the obtained thermoplastic liquid crystal polymer film was 335°C. (2) Using the thermoplastic liquid crystal polymer film obtained in the above (1) to produce metal-clad laminates and multi-layer laminated substrates. The evaluation results of wide-angle X-ray diffraction, solder float, and laminar flow on the obtained thermoplastic liquid crystal polymer film and multilayer laminated substrate are shown in the table.

[Table 7] heat treatment conditions Tm ₀ (°C) Rtm (℃/min) UC SC Tm (℃) Tm/SC productivity heat resistance Float Laminar operating range Example 1 290°C for 1 hour 310 0.28 1.30 1.50 328 219 A A A Example 2 310°C for 1 hour 310 0.28 1.45 1.50 337 225 A A A Example 3 300℃ for 1 hour 320 0.45 1.18 1.80 334 186 A A A Example 4 320°C for 1 hour 320 0.45 1.20 1.80 360 200 A A A Comparative example 1 - 280 0.17 -0.65 1.55 - - - B B Comparative example 2 - 310 0.28 -0.45 1.75 - - - A B Comparative example 3 - 320 0.45 -0.12 1.90 - - - A B Comparative example 4 260°C 1 hour 280 0.17 -0.55 1.60 290 181 B B B Comparative Example 5 280℃ for 1 hour 280 0.17 -0.50 1.65 303 184 B B B Comparative example 6 260℃ for 1 hour 290℃ for 6 hours 280 0.17 -0.20 1.85 335 181 B A A

It can be seen from Table 7 that in Comparative Example 1, because UC does not exist in a specific range, the crystals in the film do not have a highly uniform orthorhombic crystal structure, and due to poor heat resistance, it cannot meet the requirements of float soldering and laminar flow. both sides. In Comparative Examples 4 and 5, heat resistance was achieved by heating the thermoplastic liquid crystal polymer film of Comparative Example 1 at (Tm ₀ -20)°C or Tm ₀ °C for 1 hour, but UC was not in a specific range and could not be obtained. Satisfies both float soldering and laminar flow which meet the standard of heat resistance. In addition, in Comparative Example 6, heat resistance was achieved by heating the thermoplastic liquid crystal polymer film of Comparative Example 1 over 7 hours, so it was insufficient in terms of productivity. Also, even in the case of heat resistance, in Comparative Example 6, the orthorhombic crystal structure of crystals in the thin film was not uniform, so UC did not exist in a specific range.

In addition, in Comparative Examples 2 and 3, since UC did not exist in a specific range, the crystals in the thin film did not have a highly uniform orthorhombic crystal structure, so laminar flow could not be satisfied.

On the other hand, in Examples 1 to 4, since UC exists in a specific range, the uniformity of the orthorhombic crystal structure contained in the thin film is high, and any of productivity and heat resistance is satisfied. Among these thermoplastic liquid crystal polymer films, a film having an Rtm in a specific range is heat-treated in a short time of 1 hour, but sufficient heat resistance can be achieved.

Therefore, compared to the above comparative examples, like Examples 1 to 4, the thermoplastic liquid crystal polymer film with high uniformity of orthorhombic crystals satisfies either of productivity and heat resistance. Using a metal-clad laminate having such a thermoplastic liquid crystal polymer film has a wide range of operations in both lamination and circuit processing, and thus a laminate can be manufactured at low cost without using special equipment or jigs. [Possibility of industrial use]

The thermoplastic liquid crystal polymer film and laminate of the present invention are suitable as materials for various moldings (for example, circuit boards), especially as multilayer laminated circuit materials, etc., for example, as printed circuit boards in the fields of electronics/electricity/communication industries , It is useful in applications such as high-frequency circuit boards, automotive sensors, mobile circuit boards, and antennas.

As described above, although preferred embodiments of the present invention have been described, various additions, changes, and deletions are possible without departing from the gist of the present invention, and these are also included in the scope of the present invention.

1: Thermoplastic liquid crystal polymer film 2: Metal layer (copper foil) 3: Metal-clad laminate 4: SUS board 5: buffer material

Fig. 1 is a sectional view of a metal-clad laminate in one aspect of the present invention. Fig. 2 is a cross-sectional view of an assembly during fabrication of a multi-layer laminate substrate in one aspect of the present invention. Fig. 3 is a graph showing the wide-angle X-ray diffraction curve (data 3) of the heat-treated film obtained in Example 1 of the present invention.

Claims (18)

A thermoplastic liquid crystal polymer film, which is composed of a polymer capable of forming an optically anisotropic molten phase (hereinafter referred to as a thermoplastic liquid crystal polymer), and in the polymer part, a wide-angle X-ray diffracted In the detected diffraction curve, the integrated intensity on the baseline of 2θ=14~26 degrees is set to A, and the quantitative curve of the main peak in 2θ=22.3~24.3 degrees is approximated to a linear function and removed. When the integrated intensity of the quantitative curve of the secondary peak is B and B/A×100=UC, the following formula (1) is satisfied, and 0≦UC≦2.0 (1). The thermoplastic liquid crystal polymer film according to claim 1, which satisfies the following formula (2): 0.1≦UC≦1.5 (2). Such as the thermoplastic liquid crystal polymer film of claim 1 or 2, wherein when the full width at half maximum (full width at half maximum) of the main peak with a maximum value at 2θ=20±1 degrees is set to SC (degrees), it satisfies 1.4≦SC. The thermoplastic liquid crystal polymer film according to claim 1 or 2, wherein the position of the endothermic peak occurring at a temperature increase rate of 10°C/min in the temperature range from room temperature to 400°C is 310°C using a differential scanning thermal analyzer above. A laminate comprising at least one layer of the thermoplastic liquid crystal polymer film according to any one of claims 1 to 4. As in the laminated body of claim 5, it further has at least one metal layer. The laminated body of claim 6, wherein the metal layer is made of at least a kind of composition. A molded article formed from the thermoplastic liquid crystal polymer film according to any one of claims 1 to 4 or the laminate according to any one of claims 5 to 7. The molded body according to claim 8, which is a circuit board. The molded body according to claim 8 or 9, which is a high-frequency circuit board, a vehicle sensor, a mobile circuit board, or an antenna. A method for producing a thermoplastic liquid crystal polymer film according to any one of claims 1 to 4, wherein, for a thermoplastic liquid crystal polymer film composed of a thermoplastic liquid crystal polymer whose melting point rise rate Rtm is 0.20°C/min or higher, Heat treatment and heat resistance. The method for producing a thermoplastic liquid crystal polymer film as claimed in claim 11, wherein the heat treatment is a one-stage or multiple-stage heat treatment, and when the melting point of the thermoplastic liquid crystal polymer is set as Tm ₀ , the second step is performed at Tm ₀ °C or lower. Heat treatment and heat resistance. The manufacturing method of the thermoplastic liquid crystal polymer film as claimed in item 11 or 12, wherein, as the heat source, use is selected from hot air oven, steam oven, electric heater, infrared heater, ceramic heater, hot roller, hot press, and electromagnetic wave irradiation at least one type of machine. The method for manufacturing a thermoplastic liquid crystal polymer film according to claim 11 or 12, wherein the heat treatment is one stage. A method for producing a laminate according to any one of Claims 5 to 7, wherein, for a laminate having a polymer layer made of a thermoplastic liquid crystal polymer, that is, the polymer layer has a melting point rise rate Rtm of The laminated body composed of thermoplastic liquid crystal polymer at 0.20°C/min or above is heat-treated to be heat-resistant. The method for producing a laminate according to Claim 15, wherein the heat treatment is one-stage or multiple-stage heat treatment, and when the melting point of the thermoplastic liquid crystal polymer is set to Tm ₀ , the first heat treatment is performed at Tm ₀ ° C. or lower. heat resistance. The method for producing a laminate according to Claim 15 or 16, wherein, as a heat source, at least A sort of. A method of manufacturing a molded body by post-processing the thermoplastic liquid crystal polymer film according to any one of claims 1 to 4, and/or the laminate according to any one of claims 5 to 7.

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