JP2002307617A - Liquid crystal resin laminated film and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal resin laminated film excellent in interlaminar bonding properties, surface smoothness and surface adhesiveness, having excellent solder heat resistance and dimensional stability against heat and humidity and low in the anisotropy of characteristics, and to provide a method for manufacturing the same. SOLUTION: The liquid crystal resin laminated film is manufactured by laminating a heat-resistant resin layer based on a heat-resistant resin soluble in a bipolar aprotic solvent on at least the single surface of a liquid crystal resin layer, has a solder heat resistance of 280 deg.C or higher, and is stretched at least unidirectionally after the liquid crystal resin layer. The heat-resistant resin layer are directly bonded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for manufacturing a liquid crystal display device, which has excellent interlayer adhesion between a liquid crystal resin layer (film) and a heat-resistant resin layer, and which can laminate a heat-resistant resin layer without using an adhesive. The present invention relates to a liquid crystal resin laminated film having small anisotropy.

[0002]

2. Description of the Related Art Conventionally, liquid crystalline resins have been excellent in high strength, high heat resistance, low coefficient of linear expansion, high insulation, low moisture absorption, and high gas barrier properties. It has been put to practical use. In addition, I using the resin
The development of a printed wiring board for C is also under consideration.

[0003] In a liquid crystalline resin, molecules are oriented by flow even in a molten state, and when ordinary extrusion is performed, not only a strong anisotropic film is obtained due to strong orientation in the flow direction, but also in the width direction. There is a problem that a streak-like flow non-uniformity occurs in the longitudinal direction without flowing uniformly, resulting in a large thickness non-uniformity.

As a method for eliminating the anisotropy in the flow direction as described above, Japanese Patent Publication No. Hei 6-39533 and
Japanese Patent Publication No. 286626 proposes a method using an inflation method. In the liquid crystal resin film obtained by these methods, although the problem of physical property balance in the MD / TD direction was basically solved, the surface roughness inherent to the liquid crystal resin (poor surface smoothness and abrasion resistance, thickness Problem). Also, JP-A-7-251438 and JP-A-7-323
Japanese Patent Application Laid-Open No. 506 discloses a method of laminating a liquid crystalline resin and a heat-resistant resin using a flat die method and then biaxially stretching the same. A method of laminating a good thermoplastic resin film has been proposed. However, the liquid crystal resin film obtained by these methods can solve the problem of physical balance in the MD / TD direction, but has low interlayer adhesion between the liquid crystal resin layer and the non-liquid crystal resin layer, and causes delamination. Occurred and the film quality was still poor.

[0005]

As described above, when the conventional inflation method is used, not only the thickness unevenness is deteriorated, but also the surface smoothness and abrasion resistance are poor, and the defects inherent in the liquid crystal resin cannot be solved. . In addition, when laminating a heat-resistant resin to a liquid crystalline resin using the flat die method and then biaxially stretching, although the anisotropy of the liquid crystalline resin film and poor adhesion of the film surface are eliminated, The resin and the heat-resistant resin caused delamination, and the quality of the film was still low. In addition, the liquid crystalline resin has poor adhesion to other materials, and requires chemical treatment or plasma treatment to improve the adhesion.

The present invention solves the above-mentioned disadvantages of the prior art,
Excellent interlayer adhesion between liquid crystal resin layer and heat-resistant resin layer to be laminated, excellent solder heat resistance, excellent dimensional stability to heat and humidity, excellent surface smoothness and film surface adhesion, and low anisotropy of properties It is an object of the present invention to provide a liquid crystal resin laminated film and a method for producing the same.

[0007]

Means for Solving the Problems In view of the above-mentioned problems, the present inventors have conducted intensive studies and as a result, have found that a heat-resistant resin layer is formed on at least one surface of a liquid crystal resin layer without using an adhesive. The present inventors have found that the above-mentioned problem can be solved by providing them directly, and have reached the present invention.

[0008] The liquid crystal resin laminated film of the present invention is a liquid crystal resin laminated film in which a heat resistant resin layer mainly composed of a heat resistant resin soluble in a dipolar aprotic solvent is laminated on at least one surface of the liquid crystal resin film. Wherein the liquid crystal resin laminated film has a solder heat resistance of 280 ° C. or higher. The thermal expansion coefficient of the liquid crystalline resin laminated film of the present invention is preferably 20 ppm / ° C. or less, more preferably 15 ppm / ° C. or less, and the humidity expansion coefficient is preferably 10 ppm /% RH or less, more preferably 5 ppm /% RH or less.
ppm /% RH or less.

The method for producing a liquid crystalline resin laminated film according to the present invention comprises a step of applying a heat resistant resin dissolved in a dipolar aprotic solvent to at least one surface of the liquid crystalline resin film; A method for producing a liquid crystalline resin laminated film, comprising a step of stretching a resin film in at least one direction.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described.

The liquid crystalline resin laminated film of the present invention is basically composed of a liquid crystalline resin layer (film) and a heat resistant resin layer mainly composed of a heat resistant resin soluble in a dipolar aprotic solvent.

The liquid crystalline resin used in the present invention comprises:
It is a resin having a regular structure such as a crystal even in a molten state, such as a thermotropic liquid crystal resin, and conventionally known liquid crystal polyester resins and liquid crystal polyester amide resins can be used.

For example, in the case of a liquid crystalline polyester resin,
A liquid crystalline polyester containing 40 to 90% by weight of a parahydroxybenzoic acid (HBA) component as a main mesogen and containing 4,4′-dihydroxybiphenyl (DHB) for improving fluidity is preferred. The mesogen may be contained in any form such as random copolymer, block copolymer, branch copolymer, and a combination thereof. In the case of the present invention, polyethylene terephthalate (PET) or polyethylene naphthalate (PE) may be used.
N) / HBA / DHB / liquid crystalline resin composed of terephthalic acid (TPA), copolymer containing HBA / 6-hydroxy-2-naphthoic acid as a main component, HBA / 4,4′-dihydroxybiphenyl and terephthalic acid , A copolymer of isophthalic acid, a copolymer of 6-hydroxy-2-naphthoic acid and paraaminophenol, a copolymer of HBA / hydroquinone (HQ) / sebacic acid (SA) and the like are preferably used.

The liquid crystalline resin used in the present invention includes:
In addition to the above liquid crystalline polyester resin, liquid crystalline polyester amide or lyotropic liquid crystal resin can be used. Examples of the liquid crystal polyester amide include, but are not limited to, a copolymer of 6-hydroxy-2-naphthoic acid / aromatic hydroxylamine / aromatic dicarboxylic acid. As the lyotropic liquid crystal resin, poly (p-phenylene terephthalamide)
A concentrated sulfuric acid solution of (PPTA), an aqueous solution of silk fibroin, and an aqueous solution of sericin include, but are not limited to.

The liquid crystalline resin composed of such components has a regular structure even in the molten state, and the molecules are easily oriented in the flowing direction by the flow during the melting.

Instead of using the liquid crystal resin alone, a polymer alloy containing the above liquid crystal resin may be used. Examples of the polymer for alloy to be mixed or chemically bonded include thermoplastic resins such as polyamide, polyimide, polyamideimide, polyetherimide, polyarylate, polyphenylene sulfide, polyetheretherketone, polyethersulfone and polysulfone. .

The mixing ratio of the liquid crystalline resin and the polymer alloy is preferably from 10:90 to 90:10 by weight.
The ratio is more preferably from 20:80 to 80:20. A polymer alloy containing a liquid crystal resin also has excellent properties due to the liquid crystal resin.

In the liquid crystal resin laminated film of the present invention, a heat resistant resin layer mainly composed of a heat resistant resin soluble in a dipolar aprotic solvent is preferably formed on at least one surface of the liquid crystal resin layer. It has a laminated structure without the use of an adhesive.

An example of a dipolar aprotic solvent is N 2
-Methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, dimethylsulfoxide and the like. In the present invention, the dissolution of the heat-resistant resin in these dipolar aprotic solvents has a very important meaning in the interlayer adhesiveness between the liquid crystalline resin layer and the heat-resistant resin layer. It is difficult to obtain sex. That is, a solvent that dissolves the heat-resistant resin and swells the liquid crystalline resin layer is particularly preferable, and among the above, N-methyl-2-pyrrolidone is particularly preferable.

The heat-resistant resin laminated in the present invention preferably has a glass transition temperature of 170 due to its heat resistance.
Those having no melting point or decomposition point at or above 300 ° C. and / or below 300 ° C., more preferably at 250 ° C. or above and / or
Or those having no melting point or decomposition point below 300 ° C, more preferably above 270 ° C and / or 3
It has no melting point or decomposition point below 00 ° C. The heat-resistant resin selected from the above requirements may be any resin that satisfies the requirements, and examples thereof include an aromatic polyamide resin, an aromatic polyimide-based resin and a precursor thereof, a polyamideimide-based resin, and a polyamide-based resin. Examples thereof include ether sulfone resins, polyetherimide resins, polybenzimidazoles and precursors thereof, polybenzoxazoles and precursors thereof, polybenzthiazoles and precursors thereof, and polysulfone resins. However, when a liquid crystal resin layer is used as the base material,
Aromatic polyamide resins are particularly preferred in terms of heat resistance, dimensional stability, recoverability by re-dissolution, and the like of the laminate.

In the present invention, preferred aromatic polyamides include repeating units represented by the following general formulas (1) and / or (2) in an amount of 50 mol% or more, alone or in a copolymerized form. And preferably 70% by mole or more of aromatic polyamide.

[0022]

Embedded image

[0023]

Embedded image Here, for Ar ₁ , Ar ₂ and Ar ₃ , for example, those shown in the following general formula (3) are used, and X and Y are —O—,
_{-CH 2 -, - CO -,} - SO 2 -, - S -, - C (CH
₃ ) It is selected from _2- and the like, but is not limited thereto. Further, some of the hydrogen atoms on these aromatic rings may be substituted with halogen groups such as chlorine, fluorine and bromine (particularly preferably chlorine), and alkyl groups such as nitro group, methyl group, ethyl group and propyl group (particularly methyl group). Are preferred), those substituted with a substituent such as an alkoxy group such as a methoxy group, an ethoxy group, or a propoxy group, and the hydrogen in the amide bond constituting the polymer is substituted with another substituent. It also includes things.

[0024]

Embedded image In particular, a polymer in which the aromatic ring of the general formula (2) is bonded at the para position accounts for 50 mol% or more, more preferably 70 mol% or more of the total aromatic ring, has heat resistance and dimensional stability. It is preferably used in view of the above. Some of the hydrogen atoms on the aromatic ring are halogen groups such as chlorine, fluorine and bromine (particularly preferably chlorine), and alkyl groups such as nitro, methyl, ethyl and propyl groups (particularly preferred are methyl groups). ,
When the aromatic ring substituted with a substituent such as an alkoxy group such as a methoxy group, an ethoxy group or a propoxy group accounts for 30 mol% or more, preferably 50 mol% or more of the whole, the moisture resistance and the dimensional stability at the time of moisture absorption are improved. Be improved.

In the present invention, an aromatic polyamide containing 50 mol% or more, preferably 70 mol% or more of the repeating unit represented by the above general formula (1) and / or general formula (2) is desirable. Copolymers of other compounds less than this or other polymers may be mixed.

The heat-resistant resin layer of the present invention may contain various additives, a resin composition, a crosslinking agent, and the like. For example,
Antioxidants, heat stabilizers, ultraviolet absorbers, organic and inorganic particles, pigments, dyes, antistatic agents, nucleating agents, acrylic resins,
Polyester resin, urethane resin, polyolefin resin, polycarbonate resin, alkyd resin, epoxy resin, urea resin, phenol resin, silicone resin, rubber resin, wax composition, melamine crosslinker, oxazoline crosslinker, methylol, alkylol Urea-based crosslinking agents, acrylamide, polyamide, isocyanate compounds, aziridine compounds, various silane coupling agents, various titanate coupling agents, and the like.

Among these, when inorganic particles such as silica, colloidal silica, alumina, alumina sol, kaolin, talc, mica, calcium carbonate, barium sulfate, carbon black, zeolite, titanium oxide, and fine metal powder are added. Improves the lubricity and scratch resistance. The average particle system of the inorganic particles is preferably 0.0
It is from 0.05 to 5 μm, more preferably from 0.05 to 1 μm. The addition amount is preferably 0.05 to 20 parts by weight, more preferably 0.1 to 10 parts by weight.

In the present invention, a dissolution aid such as lithium chloride may be further contained for the purpose of improving the solubility of the aromatic polyamide resin in a dipolar aprotic solvent.

In the present invention, the method of laminating the heat resistant resin layer on the liquid crystal resin layer includes a method of directly bonding the heat resistant resin layer dissolved in a dipolar aprotic solvent to at least one surface of the liquid crystal resin layer. Can be suitably adopted. This does not mean that the adhesive is interposed as in the conventional method, but that the liquid crystal resin layer and the heat resistant resin layer have an interface between the liquid crystal resin layer and the heat resistant resin layer when the heat resistant resin layer is laminated on the liquid crystal resin layer. This means that a layer made of a substance other than the resin and the heat-resistant resin is not substantially formed. However, when a mixed layer of a liquid crystalline resin layer and a heat-resistant resin layer is formed at the interface, it is particularly preferable because the adhesiveness is further improved, and this layer is out of the definition of the adhesive layer.

The adhesiveness between the heat-resistant resin layer (laminated film) and the liquid crystalline resin layer (substrate) of the thus obtained laminated film is “100 g / 25 mm width” or more in T-peeling.
It is preferable that the layers are laminated so as to have a thickness of “200 g / 25 mm width” or more. Adhesion is "100g / 25
If the width is less than “mm width”, a problem that the laminated film is peeled off may occur.

The thickness of the liquid crystalline resin laminated film of the present invention can be set according to the intended use. According to the findings of the present inventors, the thickness of the laminated film on at least one surface is preferably 0.2 to 20%, more preferably 0.5 to 10% of the thickness of the base liquid crystal resin layer, This is a preferred embodiment in the production process for obtaining the liquid crystalline resin laminated film of the present invention.

The soldering heat resistance of the liquid crystalline resin laminated film of the present invention must be 280 ° C. or higher. Solder heat resistance temperature is more preferably 290 ° C or higher,
More preferably, it is 300 ° C. or higher. If the soldering heat-resistant temperature is lower than 280 ° C., deformation or warpage occurs during soldering. In addition, the harmfulness of lead has been pointed out, and lead-free solder has been put into practical use. Since lead-free solder has a melting point higher than that of conventional solder by 30 ° C or more, it is necessary to have a solder heat-resistant temperature of 280 ° C or more. Become. The liquid crystalline resin laminated film of the present invention has a solder heat resistance temperature of 280.
It is most preferable to use a liquid crystalline resin having a temperature of
Even when a liquid crystalline resin having a temperature lower than 80 ° C. is used, the heat resistant resin having a solder heat resistant temperature of 280 ° C. or more can be laminated on the surface layer to have a solder heat resistant temperature of 280 ° C. or more.

The coefficient of thermal expansion of the liquid crystalline resin laminated film of the present invention is preferably 20 ppm / ° C. or less, more preferably 15 ppm / ° C. This is because the liquid crystal resin laminated film of the present invention is required to have substantially no dimensional deformation of the film due to heat in a high temperature range of about 80 to 260 ° C. This is because when the liquid crystal resin laminated film of the present invention is used as a substrate film for a circuit board, when the substrate film is deformed by this heat when exposed to a high temperature atmosphere of 80 to 260 ° C. during a manufacturing process, a precise circuit is formed. This is due to the inability to form.

Furthermore, the liquid crystalline resin laminated film of the present invention
Is preferably 10 (× 10^-6/% R
H) or less, more preferably 5 (× 10^-6/% RH)
Below. Use this as a substrate film for circuit boards
, Β is 10 (× 10 ^-6/% RH)
And the change in humidity under the use environment during the manufacturing process as above
Precise circuit formation when substrate film deforms due to
Can not be done. To avoid this, humidity control equipment and film
Requires a drying step, which is not preferable in terms of productivity.

The liquid crystal resin laminated film of the present invention comprises a step of applying a heat-resistant resin dissolved in a dipolar aprotic solvent to at least one surface of the liquid crystal resin film; It can be obtained by a manufacturing method including a step of stretching in one direction. Here, after stretching, the solvent is evaporated and heat-fixed. In this case, stretching in a state in which the solvent remains is a preferable embodiment for further improving the interlayer adhesion between the liquid crystalline resin layer and the heat resistant resin layer. The preheating and stretching temperatures are 85 to 350 ° C, the heat treatment temperature is 200 to 400 ° C, and the solvent used is preferably a solvent having a boiling point of 160 ° C or more and 250 ° C or less. N-methyl-2-pyrrolidone is particularly preferably used as such a solvent and a solvent for dissolving a heat-resistant resin such as an aromatic polyamide.

After the solvent evaporates, the liquid crystalline resin laminated film may be further stretched in the longitudinal direction and the width direction.
The liquid crystalline resin laminated film thus re-stretched can further improve strength and rigidity. When re-stretching in the longitudinal direction or the width direction, the stretching temperature is preferably from 85 to 350 ° C, and the stretching ratio is preferably from about 1.1 to 3.0 times. After the re-stretching, heat treatment can be further performed at a temperature of 200 to 400 ° C, preferably 220 to 350 ° C.

Next, a method for producing the liquid crystalline resin laminated film of the present invention will be illustrated below, but the present invention is not necessarily limited thereto.

The sufficiently dried liquid crystalline resin is supplied to a melt extruder such as a single-screw extruder, a twin-screw extruder, a vent extruder, a tandem extruder and the like, and the molecular weight, for example, intrinsic viscosity [η]
Is extruded under a nitrogen stream or under vacuum so as not to lower as much as possible. Here, in order to remove foreign substances in the raw material, it is preferable to extrude the molten resin while appropriately filtering the molten resin with a filter, for example, a sintered metal, a porous ceramic, a sand, a wire mesh, or the like. After melt extrusion, 20
Form a sheet on a mirror cooling drum at ド ラ ム 100 ° C. On this occasion,
The molten sheet is tightly cooled and solidified by a known adhesion means such as an electrostatic application method, an air chamber method, an air knife method, and a press roll method.

A heat-resistant resin dissolved in a solvent to be laminated is applied to at least one surface of the cast film thus obtained, and then stretched in at least one direction. The stretching method is vertical uniaxial stretching or horizontal uniaxial stretching. Stretching is performed by any method such as sequential biaxial stretching and simultaneous biaxial stretching. The stretching is performed through a preheating step of 80 to 350 ° C. and 120 to 350
Stretching is performed 2 to 8 times in the range of ° C. In addition, 18
Heat treatment is performed at 0 ° C. to 350 ° C. to completely volatilize the solvent in which the heat-resistant resin is dissolved. Here, in the case of stretching, it is preferable that the solvent is stretched together with the base material before the solvent is completely dried, and then the solvent is evaporated and evaporated. It is preferable to evaporate and evaporate in the subsequent heat treatment step from the viewpoint of adhesiveness to the substrate and stretchability in a laminated state.

The liquid crystalline resin laminated film thus obtained has excellent adhesiveness between the liquid crystalline resin layer and the heat-resistant resin layer, excellent adhesiveness and smoothness on the film surface, and isotropic properties. Yes, it is suitable for use as a circuit board provided with a conductor pattern on at least one surface.

[Measurement Method of Physical Properties] Next, the measurement methods used in the present invention will be described below.

1. Solder heat resistant temperature A sample cut into a 2 cm square was floated in a solder bath set at a temperature of 260 ° C. for 30 seconds and evaluated according to the following criteria. ：: No change at all ：: Softening, deformation, peeling, wrinkles are partially observed ×: Deformation or peeling such as waving or bending on the front surface, and the dimensional change rate of each layer is large.

2. Thermal expansion coefficient α (× 10 ⁻⁶ / ° C.) TMA / SS61 manufactured by Seiko Instruments Inc.
Using a sample of 4 mm wide and 15 mm initial length
A thermal expansion coefficient was determined from the gradient of the thermal deformation displacement during the temperature rise / fall process when the temperature was raised from room temperature to 300 ° C. under the condition of a temperature rise / fall rate of 20 ° C./min under a tensile load of 20 g / min. . The unit is 10 ^-6 / ° C.

3. Humidity expansion coefficient β (× 10 ⁻⁶ /% RH) A sample is cut out to a width of 10 mm, and a constant load elongation tester (Nippon Automatic Control Co., Ltd., constant load elongation) set in a constant temperature and humidity chamber (PKL-50D manufactured by Daiei Chemical) The sample is sandwiched by a tester) so that the distance L between the chucks becomes 200 mm, and humidified from 5 RH% to 85 RH% at 25 ° C. (ΔRH =
(80 RH%) was obtained by the following equation from the deformation amount ΔL. β = (ΔL / L) / ΔRH, and the unit is 10 ⁻⁶ /% RH.

4. Glass transition temperature, melting point The liquid crystalline resin laminated film is immersed in a bipolar aprotic solvent, the base film is separated and filtered from the solution in which the laminated film is dissolved, the remaining solvent is evaporated, and the remaining solid content is determined by DSC.
(Differential scanning calorimeter).

5. Interlaminar adhesive strength 100 crosscuts of 1 mm ² were inserted into the laminated film of the liquid crystalline resin laminated film, and a cellophane tape manufactured by Nichiban Co., Ltd. was attached.
(Reciprocating), and then the cellophane tape was rapidly peeled off in the 90 ° direction, and the number of laminated films remaining on the laminated film side was measured. If 90 or more were left, it was evaluated as ○, if less than 90, 50 or more, Δ, and if less than 50, ×.

6 Film thickness configuration A cross section was cut out from the laminated film, and the cross section was observed with a transmission electron microscope to measure the thickness of the laminated film. When there was a mixed phase, the thickness including the mixed phase was defined as the lamination thickness.

7. Surface smoothness The surface roughness Ry was measured at room temperature with a measurement length of 2 mm and a cutoff of 0.25 mm according to JIS B0601. As a measuring device, a three-dimensional surface roughness meter manufactured by Kosaka Laboratory Co., Ltd. was used.

8. Film Surface Adhesion Aluminum was vapor-deposited on the film surface, and 100 1 mm-square crosscuts were put on the vapor deposition layer. Paste Nichiban Co., Ltd. cellophane tape on the cross cut of the vapor deposition layer,
After strongly pressing with a finger, the number of pieces that were peeled off rapidly in the direction of 180 ° and remained was determined. If 90 or more were left, it was evaluated as ○, if less than 90, 50 or more, Δ, and if less than 50, ×.

8. Mechanical properties The tensile strength of the liquid crystalline resin laminated film is JIS K712.
The measurement was performed at 25 ° C. in a 65% RH atmosphere using an Instron type tensile tester according to the method specified in 7.

[0051]

The present invention will be described in more detail by way of examples.

(Example 1) Commercially available "Siveras" manufactured by Toray Industries, Inc. was used as the liquid crystal resin (LCP), and the liquid crystal resin (LCP) was vacuum-dried at 130 ° C for 6 hours. Each of the dried raw materials was supplied to a melt extruder having a cylinder diameter of 90 mm, melted at 320 ° C., and extruded in a sheet shape from a T-shaped die. The melted film extruded in this manner was tightly cooled and solidified on a casting drum of 1 m in diameter whose surface temperature was kept at 25 ° C. by an air knife. A coating liquid for forming a laminated film was applied to both sides of the cast film. The laminated film coating solution was prepared by converting a para-aromatic polyamide biaxially stretched film having a glass transition temperature of 270 ° C. (registered trademark: Microtron (manufactured by Toray Industries, Inc.)) into N-methyl-2-pyrrolidone at a solid concentration of 5%. After melting at 60 ° C. so as to give a weight%, the mixture was cooled to room temperature and had a viscosity of 5.
Five poises were produced. The layered film forming coating liquid (5% by weight liquid) was coated by a die coating method with three heat-resistant resin layers per side.
It was applied to both sides of the liquid crystalline resin layer so as to have a thickness of 0 μm.
The coated film is supplied to a pantograph-type simultaneous biaxial stretching apparatus, guided to a preheating zone at 110 ° C., and subsequently stretched 3.5 times in a width direction in a heating zone at 300 ° C.
Heat treatment was performed at 20 ° C. In this way, a non-anisotropic laminated film having a total liquid crystal resin laminated film thickness of 60 μm and a laminated thickness of 8 μm was obtained. The interlayer adhesive strength of the laminated film thus obtained was good. The surface of the obtained laminated film was smooth and had good adhesiveness.
Table 1 shows the results.

(Example 2) A commercially available Ueno Pharmaceutical Co., Ltd. product "Ueno LCP6000" was used as the liquid crystal resin (LCP), and the liquid crystal resin (LCP) was vacuum dried at 150 ° C for 4 hours, and the drying was completed. Each of the obtained raw materials was supplied to a melt extruder having a cylinder diameter of 90 mm, melted at 350 ° C., and extruded in a sheet shape from a T-shaped die. The melted film extruded in this manner was tightly cooled and solidified on a casting drum of 1 m in diameter whose surface temperature was kept at 25 ° C. by an air knife. Example 1 Example 1 except that the same coating solution for forming a laminated film as in Example 1 was applied to both sides of the cast film so that the heat-resistant resin layer per one side was 50 µm.
Was applied in the same manner as described above. The applied film was stretched in the same manner as in Example 1 and then heat-treated to obtain a non-anisotropic laminated film having a total liquid crystalline resin laminated film thickness of 60 μm and a laminated thickness of 15 μm. The interlayer adhesive strength of the laminated film thus obtained was good. The surface of the obtained laminated film was smooth and had good adhesiveness. Table 1 shows the results.

(Example 3) After a cast film was obtained in the same manner as in Example 2, a coating solution for forming a laminated film was applied to both surfaces of the cast film in the same manner as in Example 1 so that the heat-resistant resin layer per side was 60 μm. Coating was performed in the same manner as in Example 1 except for coating. The coated film was supplied to a pantograph-type simultaneous biaxial stretching apparatus in the same manner as in Example 1,
, Followed by simultaneous biaxial stretching 1.5 times in the longitudinal direction and 4.0 times in the width direction in the heating zone at 300 ° C., followed by heat treatment at 320 ° C. In this way, a non-anisotropic laminated film having a total liquid crystal resin laminated film thickness of 46 μm and a laminated thickness of 10 μm was obtained. The interlayer adhesive strength of the laminated film thus obtained was good. The surface of the obtained laminated film was smooth and had good adhesiveness. Table 1 shows the results.

(Comparative Example 1) A biaxially stretched film of para-aromatic polyamide having a thickness of 25 μm (registered trademark: Microtron (manufactured by Toray Industries, Inc.)) was provided on both sides of the liquid crystalline resin film obtained in Example 1. The thermocompression-bonded film between a pair of heating rolls heated to 280 to 320 ° C. was supplied to a pantograph-type simultaneous biaxial stretching apparatus in the same manner as in Example 1, and
It was led to a preheating zone at 0 ° C., then stretched 3.5 times in the width direction in a heating zone at 300 ° C., and heat-treated at 320 ° C.
The laminated film thus obtained had a total liquid crystalline resin laminated film thickness of 60 μm and a laminated thickness of 7 μm, and although the anisotropy of the properties was improved, a layer composed of a liquid crystalline resin layer and a heat-resistant resin layer was obtained. The film had low inter-layer adhesive strength and large thickness unevenness. Table 1 shows the properties of the film.

Comparative Example 2 A coating liquid for forming a laminated film was applied to both surfaces of the liquid crystalline resin film obtained in Example 1. The coating liquid for the laminated film was prepared by adding polyetherimide (registered trademark: Ultem (manufactured by GE Plastics)) having a glass transition temperature of 216 ° C. to N-methyl-2-pyrrolidone so as to have a solid concentration of 5% by weight. After dissolving at 60 ° C., the mixture was cooled to room temperature to prepare a product having a viscosity of 55 poise. The coating liquid for forming a laminated film (5% by weight liquid) was applied to both surfaces of a liquid crystal resin layer by a die coating method so that the heat-resistant resin layer was 30 μm per side. The applied film is supplied to a pantograph-type simultaneous biaxial stretching apparatus, guided to a preheating zone at 110 ° C., and then continuously heated in a 300 ° C. heating zone in the width direction.
When the film was stretched five times, the polyetherimide was softened and melted, and good stretching could not be performed. Therefore, Table 1 shows the physical properties of the liquid crystalline resin laminated film obtained by evaporating and drying only the solvent without stretching after forming the laminated film.

[0057]

[Table 1]

[0058]

According to the present invention, the anisotropy of the liquid crystal film can be improved, and the obtained laminated film is a liquid crystalline resin laminated film having excellent solder heat resistance and excellent dimensional stability against heat and humidity. Obtainable. Further, according to the present invention, a layer having heat resistance as a surface layer can be laminated with good interlayer adhesion without interposing an adhesive layer.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) C08L 77:12 C08L 77:12 F term (reference) 4F006 AA35 AA38 AB38 EA06 4F100 AK01A AK01B AK47B AK49B BA02 BA03 BA13 EH462 EJ372 JA02 JA11A JB08B JD15 JJ03B JK06 JK15 JL04 JN30 YY00

Claims (6)

[Claims] 1. A liquid crystal resin laminated film in which a heat resistant resin layer mainly composed of a heat resistant resin soluble in a dipolar aprotic solvent is laminated on at least one surface of the liquid crystal resin layer. Is 280 ° C. or higher. 2. The liquid crystalline resin laminated film according to claim 1, wherein the coefficient of thermal expansion α is 20 (× 10 ⁻⁶ / ° C.) or less. 3. The coefficient of hygroscopic expansion β is 10 (× 10 ⁻⁶ /% R).
H) The liquid crystalline resin laminated film according to claim 1 or 2, wherein: 4. The heat-resistant resin is an aromatic polyamide and / or an aromatic polyimide.
4. The liquid crystalline resin laminated film according to any one of items 1 to 3. 5. The liquid crystalline resin laminated film according to claim 1, wherein the heat-resistant resin is a para-aromatic polyamide. 6. A step of applying a heat-resistant resin dissolved in a dipolar aprotic solvent to at least one surface of the liquid-crystalline resin layer, and a step of stretching the liquid-crystalline resin film coated with the heat-resistant resin in at least one direction. A method for producing a liquid crystalline resin laminated film, comprising: